• TABLE OF CONTENTS
HIDE
 Front Cover
 Acknowledgement
 Table of Contents
 Professor C. J. Pings
 Book reviews
 SUNY at Buffalo
 Introduction to ChE analysis
 The undergraduate ChE laborato...
 Bernoulli's equation with...
 The ChE design laboratory
 Flow modeling and parameter estimation...
 A computerized undergraduate process...
 A new traditional unit operations...
 An evolutionary experiment
 A forced convection demonstration...
 An integrated reactor engineering...
 Back Cover






Chemical engineering education
http://cee.che.ufl.edu/ ( Journal Site )
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Permanent Link: http://ufdc.ufl.edu/AA00000383/00041
 Material Information
Title: Chemical engineering education
Alternate Title: CEE
Abbreviated Title: Chem. eng. educ.
Physical Description: v. : ill. ; 22-28 cm.
Language: English
Creator: American Society for Engineering Education -- Chemical Engineering Division
Publisher: Chemical Engineering Division, American Society for Engineering Education
Publication Date: Summer 1973
Frequency: quarterly[1962-]
annual[ former 1960-1961]
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 Subjects
Subjects / Keywords: Chemical engineering -- Study and teaching -- Periodicals   ( lcsh )
Genre: periodical   ( marcgt )
serial   ( sobekcm )
 Notes
Citation/Reference: Chemical abstracts
Additional Physical Form: Also issued online.
Dates or Sequential Designation: 1960-June 1964 ; v. 1, no. 1 (Oct. 1965)-
Numbering Peculiarities: Publication suspended briefly: issue designated v. 1, no. 4 (June 1966) published Nov. 1967.
General Note: Title from cover.
General Note: Place of publication varies: Rochester, N.Y., 1965-1967; Gainesville, Fla., 1968-
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Resource Identifier: oclc - 01151209
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issn - 0009-2479
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System ID: AA00000383:00041

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Table of Contents
    Front Cover
        Front Cover
    Acknowledgement
        Acknowledgement
    Table of Contents
        Page 105
    Professor C. J. Pings
        Page 106
        Page 107
        Page 108
        Page 109
    Book reviews
        Page 110
        Page 111
    SUNY at Buffalo
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
    Introduction to ChE analysis
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
    The undergraduate ChE laboratory
        Page 122
        Page 123
        Page 124
        Page 125
    Bernoulli's equation with friction
        Page 126
        Page 127
        Page 128
    The ChE design laboratory
        Page 129
        Page 130
        Page 131
    Flow modeling and parameter estimation using radiotracers
        Page 132
        Page 133
        Page 134
        Page 135
    A computerized undergraduate process dynamics and control laboratory
        Page 136
        Page 137
        Page 138
        Page 139
        Page 140
        Page 141
    A new traditional unit operations laboratory course
        Page 142
        Page 143
    An evolutionary experiment
        Page 144
        Page 145
    A forced convection demonstration using solid CO2 sublimation
        Page 146
        Page 147
    An integrated reactor engineering laboratory
        Page 148
        Page 149
        Page 150
        Page 151
        Page 152
    Back Cover
        Back Cover 1
        Back Cover 2
Full Text




chmica ee education










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SUMMER 1973


Chemical Engineering Education
VOLUME 7, NUMBER 3 SUMMER 1973

Departments
106 The Educator
Professor C. J. Pings
112 Departments of Chemical Engineering
SUNY at Buffalo, J. G. Vermeychuk
and J. A. Bergantz
117 The Classroom
Introduction to ChE Analysis, T.W.F.
Russell and M. M. Denn
142 International Chemical Engineering
A New Traditional Unit Operations
Laboratory Course, Aage
Fredenslund
110 Book Reviews

Special Aai'tawto 9d^dae
122 The Undergraduate ChE Laboratory,
H. S. Fogler, A. T. Perna, and F. H.
Shair
126 Bernoulli's Equation with Friction,
Noel de Nevers
129 The ChE Design Laboratory,
Harry Silla
132 Flow Modeling and Parameter Estima-
tion Using Radiotracers,
R. W. Rousseau, R. P. Gardner, and
R. M. Felder
136 A Computerized Undergraduate Process
Dynamics and Control Laboratory,
R. A. Schmitz
144 An Evolutionary Experiment,
A. Meisen
146 A Forced Convection Demonstration
Using Solid CO, Sublimation,
D. A. Mellichamp and 0. C. Sandall
148 An Integrated Reactor Engineering Lab-
oratory,
R. D. Williams

CHEMICAL ENGINEERING EDUCATION is published quarterly by the Chemical
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105









F educator


ALIAS NEAL PINGS*







JACQUELYN HERSHEY
California Institute of Technology
Pasadena, CA 91109

Once upon a time a university professor
could, with a clear conscience, hew to his schol-
astic specialty and let administrative chips fall
where they might. But at Caltech those days are
long gone. In fact, it's a rare scholar who doesn't
have an administrative assignment outside his
classroom and lab. But "rare" is hardly adequate
to describe a man who takes on three or four.
Take C. J. Pings, professor of chemical en-
gineering and chemical physics, who is also execu-
tive officer for chemical engineering, vice provost,
and dean of graduate studies. Membership in a
clutch of committees and professional societies,
co-editorship of the journal Physics and Chemis-
try of Liquids, and editorship of a new journal
Chemical Engineering Communications round
out his multifaceted and admirable career.
Admirable, that is, except for his troubles
with the FBI. This blot on the escutcheon of
someone who has risen to such heights at his
alma mater-and become a highly respected
scientist elsewhere as well-dates back to 1951
when Neal was a senior at Caltech. Though he
had acquired the name "Cornelius" at birth in
1929 (via his father, his great-grandfather, and
his mother's sister Cornelia), he had adopted
"Neal" for all practical purposes. But the solemn-
ity of a possible job with the Atomic Energy
Commission after graduation led him to inscribe
"Cornelius" on his application. The AEC sent a
standard request for a recommendation to chem-

*Based on an article in Engineering and Science magazine,
October 1972. Published by The California Institute of
Technology.


istry professor Ernest Swift. His crisp reply that
he had never heard of any Cornelius Pings
brought a swarm of FBI agents buzzing around
Neal's hapless head.
"Living under an alias was over," says Neal.
"Before applying for any more jobs, I knew I
had to make the switch from Neal to Cornelius. I
started by going to the Registrar's office to get
my name changed on my transcript-and that's
when I found out my troubles had just begun.
There was no way, I was told, to make the change.
I produced my birth certificate; the Registrar's
staff was not impressed. I admitted that I had
lied about my name when I entered Caltech; they
suggested I get a court order for them to make
the alteration. I think we finally compromised by
putting Cornelius in parentheses on the records."
Cornelius John Pings is a native of Conrad,
Montana, a small rural community on the east
side of the Rockies. His family lived in Montana
because his grandfather had left the family home
in Wisconsin to take out a homestead in the West.
(A generation earlier his great-grandfather had
immigrated to the United States from Germany,
about the same time that his mother's ancestors
arrived from Ireland.) Neal's father struggled
through the Depression years as an electrician
with the Rural Electrification program, and
finally in 1942 went looking for his greener pas-
tures in California.
Those early years of economic insecurity gave
Pings some sturdy opinions about what an educa-
tion is for. The quest for knowledge excited him,
but a strong motivation for getting a college de-
gree was its promise of economic benefits.
Neal entered Caltech planning to become a
nuclear physicist-an ambition that lasted just
one term. But chemistry immediately filled the


CHEMICAL ENGINEERING EDUCATION














Neal had
a headon
verbal collision
with the
dietitian.


-3>


void-perhaps, he suggests, partly because of the
quality of instruction he received. Linus Pauling
and Norman Davidson taught him freshman
chemistry, and Ernest Swift was his instructor
in sophomore year. ("Anyone who survived that
course will testify to its intellectual thorough-
ness.") Howard Lucas, professor or organic
chemistry, taught him most of what he knows
about laboratory techniques.
With visions of going to work eventually for
a chemical or petroleum company, Neal took his
BS in applied chemistry-having financed four
years of college with a combination of scholar-
ships, summer jobs, and student loans. And with
the hope that this eventual job would be one of
substantial technical responsibility in industry,
he persisted through a PhD program in chemical
engineering. It was with some surprise, then,
that in 1955 he found himself turning down some
attractive job offers in industry to go with his
fellow alumnus Dave Mason, then on the staff at
JPL, to set up a new CHE department at Stan-
ford. "I decided to try academic life for one
year," he says, "and I've been at it ever since. So
much for my industrial aspirations. But I often
tell students about myself when they ask me for
career advice. My experience is that flexibility is
an asset."
Neal will testify that a little flexibility can
take a man a long way-to northern Greenland,
for instance. Thanks to his reading a notice
posted on a campus bulletin board, that's where
he spent the summers of 1955, '56, and '57. Grad-
uate student Mark Meier, now a noted authority
on glaciers, was organizing a geology field trip
and recruiting a staff.


"There's a component of engineer in me but I
wanted to go into the hard science aspects of
the liquid state ... Now, the problems are
far from solved, but I think we've made
some progress."

Right then, Neal liked what that job offered-
summer work, distance from Pasadena, outdoor
life, and moderately good pay. It also made good
use of his research background (heat transfer
3-CHEM ENG-10 cent on 12-20 11957 Bill
and thermodynamics), and he is still proud of
three professional papers resulting from the ex-
perience. ("And my children are still young
enough to be impressed when I point to Green-
land on the globe and say, "I was there.' ")
After four years at Stanford, Neal came back
to Caltech in 1959 as associate professor and as
resident associate for Fleming House. Two prob-
lems cropped up soon after he arrived. The first
was overcoming his student-bred reticence at
calling senior faculty members by their first
names. Will Lacey, now professor emeritus, cured
that difficulty with a few well-chosen words.
"You've graduated from calling me Doctor," he
said. "My name is Will!"







He and .
Marjorie
were married
in 1960 ....

i. ' __-6

r n-



The other problem was that hardy perennial
-complaints about student-house food. As resi-
dent associate, Neal had a headon verbal collision
about it with the dietitian and manager of the
student houses. Marjorie Cheney. His recollec-
tion of the effectiveness of his battle in behalf
of an improved cuisine is hazy.( Marjorie says:
"At first I thought that he would be easier to
cope with than the undergraduates, but . . .!")
One result was an "honest-to-God campus ro-
mance." He and Marjorie were married in 1960.


SUMMER 1973








Neal made a decision in his first year at Stan-
ford about the general area of research he wanted
to pursue-to understand liquids at the molecular
level. He was struck by the fact that a fairly
sizable body of knowledge existed about gases and
solids, but comparatively little about liquids.
"There's a component of engineer in me," he
says, "but I wanted to go into the hard science
aspects of the liquid state. My experiments have
been designed to lead ultimately to better theory,
which may then be applied to practical problems.
Now, 16 years after I started, the problems are
far from solved, but I think we've made some
progress."
Neal and his research group are currently in-
terested in mixtures. Understanding mixtures by
the brute force of numbers of experiments is
hopeless; there are too many possibilities. The
aim is to develop some rules for utilizing what
is known about simple substances to say how they
will behave when they are combined.
Essentially, the research is divided into three
sub-groups, each involving use of a different
technique and the simplest available systems
(monatomic rare gases such as argon and kryp-
ton, which are liquid at the temperatures and
pressures used in the experiments).
The technique Neal started working with,
which is still the backbone of his research, is that
of X-ray diffraction. Using it, his students are
able to measure the structure of fluids-the aver-
age number of neighboring atoms and their dis-
tance apart.
The second technique is a study of the refrac-
tive index of fluids, chiefly between liquid and gas.
The refractive index is a measurement of how
much a beam of light is bent as it stabs through a
liquid. The amount of bending is indicative of the
electrical environment of local areas of the liquid
and also gives some idea of its density.
The third technique is to use lasers for light-
scattering to study the motion of the molecules in
fluids. This is fairly new, and with it Neal says,
"We can make some very exciting measurements
and get some wholly new information. And we
don't yet have any idea of its full potential."
While the orientation of Neal's research
group is basically experimental, he makes sure
that they keep in touch with theoreticians. "We
try to find experiments to challenge or confirm
the theories we hear about," Neal says. "Then,
from our data, we are able to suggest new
approaches to the theoreticians, and we listen


W '4 Admirable,
_ except for
' his troubles
with the FBI ...






when they suggest what we should be doing in
the laboratory."
Of course, Neal doesn't listen to just the local
theoreticians. He is a regular participant to scien-
tific meetings, including the Gordon conferences.
The Gordon Research Conference on the Physics
and Chemistry of Liquids meets biennially, and
Neal has attended the last seven of them. (He
was chairman of the one in 1969). Attendance is
limited to 120 researchers, carefully chosen for
a good mix between already established and
younger scientists. "Those conferences are a
beautiful experience," Neal says. "For one whole
week you're with your colleagues-theoreticians
and experimentalists-in continuing conversa-
tion. And we correspond over the intervening
months too-asking questions, checking results,
making suggestions. I grumble a lot about meet-
ings, but not about these."
Bringing ability and good nature to his meet-
ings, Neal makes both friends and progress in the
process. Some of his success must surely stem
from his genuine commitment to Caltech and to
higher education. "I want to do what I can to help
both of them thrive, to adapt to changing times,
and to stay ahead of their problems," he says.
Neal has taken some razzing about the num-
ber of jobs and titles he carries, but he doesn't
feel that his case is noteworthy. "A lot of people
around here are carrying administrative tasks
and practicing the trade simultaneously," he says,
"and it's not all that hard. The bureaucracy is
minimal, which makes it possible to get hold of
people and talk things out. Of course, you have to
make choices. I regret losing some of the rapport
I used to have with undergraduates. I missed
teaching last year, so I'm glad to be back at it
now-giving the thermodynamics course.
I suppose there's some ham in me, but to stand


CHEMICAL ENGINEERING EDUCATION









up in front of a class and feel you're conveying
knowledge and maybe affecting attitudes can be
very satisfying. But I won't go into class half
prepared."
Juggling the requirements of his various
posts and his available time also keeps Neal from
getting into the lab to make his own measure-
ments. But he meets with his research group
(smaller in these days of funding difficulties than
it used to be) as often as he can, and he makes
himself available for conferences on individual
problems. The formalities of setting up such
meetings are a little more complex than they once
were, but he feels responsible for keeping track
of what's going on and trying to be helpful.
William Corcoran, professor of chemical engi-
neering and vice president for Institute relations,
who has known him since 1952, puts the matter
succinctly: "Nobody ever gets short changed by
Neal."
The list of Neal's contributions over the years
on many Caltech administrative and faculty com-
mittees is a long one, and his chairmanship of the
Ad Hoc Committee on the Aims and Goals of the
Institute (1969-1970) epitomizes that kind and
degree of service. Rodman Paul, Harkness Pro-
fessor of History, who has known Neal since he
taught him history as an undergraduate, was
also a member of that committee. He recalls that
through all the long months of its deliberations
Neal "displayed tremendous fairness, calmness,
and breadth of understanding. He is a good scien-
tist who deals with human beings in human ways.
When Harold Brown was chosen as president of
the Institute, it was clear that somehow he would
have to be thoroughly briefed. It was Neal more
than anyone else who pointed out that the report
of the Aims and Goals Committee would be ex-
actly what was needed to do the job. So, we
shoved it through with a speed that didn't seem
possible, and gave it to the president. I think
it was the most thorough analysis and appraisal
of Caltech that has ever been made."
Neal says, "Working on that committee con-
vinced me-and others-that an institution like
this doesn't run itself. We're fortunate here that
the faculty is involved in decision making. It was
clear at the time the committee was appointed
that we were heading into a period when we were
going to be subject to severe constraints, that we
were going to have to live by our wits. There
were going to be choices and decisions, and if the
faculty wanted to get in on those, it was going to


Neal's administrative
posts include executive
officer, vice provost,
and dean of graduate
' studies.





have to make its views known and some of its
members available for administrative positions.
It's probably not a coincidence that 60 percent of
the committee's members have ended up in ad-
ministration."
Neal's own administrative posts include being
executive officer for chemical engineering, vice
provost, and dean of graduate studies. One reason
he continues as executive officer is that the chemi-
cal engineering faculty is, on the whole, very
young and involved in starting their own research.
"It doesn't make sense to dilute their time with
administration at this point," says Neal. "We're
really victims of our own strategy, because we
have deliberately been recruiting young men-
but it will pay off in the long run."
Most of the day-to-day operations of the grad-
uate office-admission and support of students,
management of the office, direct contact with the
various option representatives, and participation
in national and regional groups concerned with
graduate education-have been turned over to
Associate Dean Stirling Huntley, with Neal being
involved in policy making, budgeting, and work-
ing with the Graduate Studies Committee.
As vice provost, he has specific responsibility
for all new and renewal appointments on the re-
search ladder, for the faculty portion of the Insti-
tute's Affirmative Action Program, for the library
and the Industrial Relations Center, and for in-
terdisciplinary programs. Basically, however, he
sees his task to be relieving the load carried by
Provost Robert Christy. Somewhat ruefully he
points out: "We have to handle questions that
once didn't even arise: How do you try to do as
much, and maybe more, research on less money?
How do you keep a young faculty when you can't
afford to appoint new people?
"There are lots of kinds of jobs around here,
and I like to sample them," says Neal. "I enjoy


SUMMER 1973









feeling useful; I like to free time for others to do
what they want to do. And there's enough of the
competitor in me that I don't mind working at
being successful. Each of my jobs calls on differ-
ent talents, responses, parts of temperament, and
combinations of whatever abilities I have. And
each makes vulnerable different kinds of short-
comings. Research demands analytical thought
processes plus whatever creativity I have, and
that rather severely exposes the limits of my in-
tellect. Supervision of personnel and administra-
tion in general require exercising judgment on
problems dominated by values and the ramifica-
tions of human personality. I often find myself
failing in these situations-either because I try
to find an exact answer to a diffuse problem or, at
the other extreme, I compromise in making a
difficult decision because I give in to a desire to
be liberal or compassionate."
Administrative work is harder than either
teaching or research as far as Neal is concerned
-a fact which, he thinks, may reflect his lack
of training in its techniques. The problem boils
down to persuading other people to do things for
him, and he attacks it by assuming that the people
he deals with are reasonable individuals.
Like many another Caltech professor, Neal
often takes a loaded briefcase home. Even when
he leaves his work at the office, he finds it hard
to take a real break from his duties unless his
family can lure him out of town-preferably to
the mountains or the beach. He feels that he is
overdue for a leave of absence for about six
months at another university. Such breaks in
routine lend perspective. But he expects the ex-
perience will just confirm his conviction that Cal-
tech really is an outstanding place.
He has been investing in that conviction for
a long time. As an undergraduate Neal Pings was
a member of the Beavers, the Board of Control,
the Interhouse Committee, Throop Club, and-
with real devotion-the varsity football team. All
this adds up to top-notch credentials for his elec-
tion to the board of directors of the Alumni Asso-
ciation. He took on this three-year job in 1970
not only because he was interested but because he
had a two-way feeling of responsibility. He be-
lieves the faculty hasn't made adequate use of the
talents of the alumni, and that the alumni could
do a lot more for Caltech. As a man with a foot
in each camp, he thinks he may be able to im-
prove communications between the two groups.


If Neal's services as vice chairman of Pasa-
dena's Community Redevelopment Agency seem
tangential to the academic circle in which he
usually operates, the appearance is only super-
ficial. He's not there as an official representative
of Caltech, but he points out: "I'm concerned
that 20 years from now Caltech will be located in
a city where it's still pleasant to live and to send
children to school. The decisions that are being
made right now will affect that. Faculty members
here have always been involved in national
affairs, but local involvement is just as important.
Caltech can't isolate itself from Pasadena, and
maybe I can be a bridge."
Not even the FBI could find anything wrong
with that.


IM book reviews

Introduction to Chemical Engineering Analysis,
T. W. F. Russell and M. M. Denn, 502 pp., John
Wiley and Sons, Inc., New York, 1972

Do not be misled by the title of the book: this
is not just another textbook for an introductory
stoichiometry course. The fundamental approach
is that of an integrated view of the entire typical
chemical engineering curriculum. The authors
have decided that it is time to use something
other than furnaces and sulfuric acid plants to
form the background for such an introductory
course. Their choice is the fluid-filled vessel, in
many of its ramifications. Real chemistry is used
throughout.
Those familiar with the structure of the chem-
ical engineering curriculum will find that there
are several mini-texts included here. Kinetics,
design, extraction, reactors, energy balances, pro-
cess dynamics, and mixing are all present. The
introduction does a good job of intriguing the
student, and the second and third chapters form
a reasonable introduction to modeling principles.
There is also a chapter on data analysis in the
midst of other topics.
The first law of thermo-energy balances is
covered well. There are accompanying mini-texts
on convective heat transfer, non-isothermal re-
actors, and gas behavior.
Perhaps of more interest to the potential
user is what is not in this book. There is no sepa-
rate treatment of material balance principles.
(Continued on p. 128)


CHEMICAL ENGINEERING EDUCATION







Over half the towns in the United States

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The reason is sad.


Money. Literally over half our towns
haven't got enough money to build com-
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And many towns that have complete
plants aren't cleaning the water thoroughly
because the towns have outgrown the
plants. And they can't afford to expand.
So, because of money, towns are forced
into polluting our streams and rivers.
Union Carbide has discovered a new
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change in wastewater treatment in thirty
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Instead of the conventional aeration sys-
tem that cleans water by mixing it with the
air, Unox forces pure oxygen into a series
of closed treatment tanks. This forced oxy-
gen technique cleans wastewater in less


time, less space and reduces the total cost
up to forty percent.
It means a town can boost its wastewater
system by simply adapting the Unox Sys-
tem to the existing system. And towns with
limited means can now afford a complete
system.
A number of cities andindustries through-
out the country have already chosen the
Unox System. And more installations are
being planned.
We've discovered a cheaper way to treat
wastewater because our streams and rivers
can't afford to wait.


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SUNY AT BUFFALO

J. GREGORY VERMEYCHUK and
JOSEPH A. BERGANTZ

In a brief existence spanning but a dozen
years, the Department of Chemical Engineering
at the State University of New York at Buffalo,
which began with a faculty of three and a hand-
ful of students, has rapidly developed into a full-
scale operation with thirteen faculty members
and a sizeable graduate program. Buffalo's ChE
department is the only such department in the
State University of New York. The SUNY system
comprises four major graduate centers, many
four-year Colleges, a multitude of two-year insti-
tutions, and a number of special purpose installa-
tions. The entire system serves approximately
115,000 students, while the graduate center at
Buffalo, including its noted medical school, has
an enrollment of 22,000, distributed among two
major campuses and a collection of other sites
throughout the city and its environs.
On a 1000 acre site to the North of the city,
construction proceeds apace on a totally new, $650
million campus. This, and a number of other fac-
tors, suggest a period of continued growth for
our department.
The Department of Chemical Engineering is
one of six engineering departments in the Faculty
of Engineering and Applied Sciences. FEAS and
six other Faculties constitute the University Cen-
ter at Buffalo. Due to the nature of this form of
organization, students and faculty can work
within the atmosphere of a small engineering


school, yet have the tremendous diversity and
varied human and material resources of a major
university within easy reach.

THE STAFF AND ITS ACTIVITIES
It is a truism that the quality of an academic
department may be gauged by the qualifications
of each faculty member. The staff of our depart-
ment incorporates expertise in all the classical
areas of ChE, and in a number of specialized
areas related to ChE, such as process metallurgy,
environmental and biomedical engineering, and
modern control theory. The faculty maintains an
extensive and productive program of research,
as indicated by approximately 50 journal articles
published during the 1971-72 academic year.
Several books and edited conference proceedings
by faculty have also appeared during the past two
years.
Since our departmental faculty is drawn from
a range of educational backgrounds (three of our
number received the Ph.D. degree in physical
chemistry), joint research projects crossing de-
partmental bounds are inevitable. Many of our
research publications result from collaboration
with cell biologists, mechanical engineers, physi-
cians, geologists and chemists.
In addition to the usual man-to-man research
collaboration, the structure of the University
allows the development of more formal means of
interdisciplinary academic activity. A Center for
Process Metallurgy was formed in 1969 to per-
form research on problems related to the steel
and other metallurgical industries. Two of the
three professors involved in the center, including
the director, are members of the Department of


CHEMICAL ENGINEERING EDUCATION









In ... but a dozen years, the Department which began with a faculty of three has developed
into a full-sized operation with 13 faculty members and a sizeable graduate program.


Chemical Engineering. This Center, in addition
to funding provided by industrial firms, has re-
ceived a grant from the NSF/RANN program for
the investigation of the applications of optimiza-
tion to the steel industry.
Three chemical engineers are members of the
Center for Theoretical Biology, which carries on
investigations in many diverse areas germane to
the biological sciences, and which publishes the
Journal of Theoretical Biology. Two other mem-
bers of our faculty have provided papers pub-
lished in this journal.
Another member of our department founded
and has served as Master of the Rachel Carson
College, an established undergraduate center for
the study of modern technology and its impact on
the environment.
For the area of undergraduate and graduate
teaching, our department is comparably active.
Innovation in teaching has been an important
theme. Two noteworthy new courses appearing in
the present academic year are a lower division
offering in Introduction to Chemical Engineering,
providing a modern approach, and a graduate
course in the Applications of Immobilized
Enzymes.
ChE faculty members also serve as instruct-
ors in FEAS-wide sophomore level courses in
thermodynamics and materials science. These
two courses provide the basic introduction to
these topics for all engineering students within
the University.
The matter of undergraduate advisement
ranks high in importance. Advisement seminars
are presented to all engineering freshmen, and
an extensive advisement brochure assists our
undergraduates in tailoring their individual pro-
grams to specific needs.
Perhaps the best way to provide an in-depth
look at our department is to consider each mem-
ber of our faculty on an individual basis.

JOE BERGANTZ is the man responsible for the crea-
tion of the department and served as our first chairman.
In this position, Joe hired most of the present faculty.
Additionally, he has served as Acting Provost of the
Faculty of Engineering and Applied Sciences. Joe's cur-
rent research interests lie in the investigation of gas-
solid reactions which can be used to purify manufac-
tured gaseous fuels (i.e., resulting from the gasification
of coal) without loss of thermal efficiency.


Joe
Bergantz:
the man
responsible
for creation
of the
department.









DON BRUTVAN, one of the original members of the
department, now holds but a one-eighth-time appoint-
ment, since his prime function lies in University Admin-
istration. Don is Associate Dean of the Division of Con-
tinuing Education which serves some 6500 students, in
both credit-carrying and credit-free programs.
HARRY CULLINAN, our present chairman, joined
the department in 1964. Harry is continuing his experi-
mental program for the determination of selected liquid-
phase diffusion coefficients. This program makes use of
a novel ultracentrifugal equilibrium sedimentation tech-
nique for the determination of the composition deriva-
tives of chemical potential for multicomponent liquid
mixtures. He is also conducting theoretical work to show
how the principles of non-equilibrium thermodynamics
apply to the solution of coupled transport phenomena.
During 1972-73, Harry has been on Sabbatical leave at
the University of Manchester Institute of Science and
Technology, Manchester, England.
PAUL EHRLICH, a physical chemist by training,
teaches both graduate and undergraduate courses in poly-
mer materials, polymerization, and thermodynamics. Paul
has completed experimental measurements and a theoreti-
cal analysis of the volumetric properties of ethane-n-hep-
tane mixtures in the supercritical region, including the vi-
cinity of the critical locus, and plans to extend his work to
other paraffin mixtures. Plans are also underway for new
studies of the observed divergence from classical predic-
tions of thermodynamic and transport properties of ma-
terials at the critical-locus. Paul also has completed an
ESR study of crystallizable, high-molecular weight
polythenylacetylene. This work promises to be of sig-
nificance in the design of improved polymeric semiconduc-
tors and photoconductors.


SUMMER 1973















Bill Gill,
Provost, also
supervises
two post-docs
and nine
graduate
students.







BILL GILL, who joined us in September, 1971, is
Provost of FEAS. The heavy administrative load has not
impeded his program in teaching and research, however,
Bill currently supervises a group of two post-does and
nine graduate students. With R. Sankarasubramanian,
he continues the development of a new solution technique
for convective diffusion problems by generalization of
their original approach to dispersion problems to include
interphase transport and chemical reaction. Bill and
M. Doshi are working on a countercurrent ion exchange
unit and have succeeded in markedly increasing the
efficiency of such units. This work has led to a simple
model which seems to explain the effects of bypassing
quite adequately. He is studying both theoretically and
experimentally the properties of tubular and hollow-fiber
reverse osmosis systems. Experimental work with L.
Derzansky has shown that natural convection in tubu-
lar R. O. systems has a significant bearing on perform-
ance. An analysis of hollow fiber systems has led to
an approach to optimal design which appears to hold
promise. In collaboration with GREG VERMEYCHUK a
study is underway on the oxygenation of liquids in open-
channel turbulent flow. Greg and Bill are preparing an
experimental study of the effectiveness of diffusion
boundary layer withdrawal in the improvement of per-
formance in R. O. systems. Alternating sections of selec-
tive and non selective membranes will be used.
Another physical-chemistry trained member of our
department is BOB GOOD. Bob has recently shown that
certain anomalies in the rate of penetration of a liquid
into a porous body such as a bed of powder, or a capillary,
can be explained with the aid of a generalization of the
Washburn equation for capillary flow. He has discovered
an anisotropic effect in the wetting of stretch-oriented
polymers, and a heat effect in the peeling of a pressure-
sensitive tape. He has developed a general theory of the
contact angles of liquids on solids and has very recently
published a theory that is an important advance in the
understanding of interfacial separation in adhering sys-
tems. He has shown that the adhesion of living cells to
each other in tissues is due to forces that physical
chemists and chemical engineers have been studying for
a number of years, with respect to the stability of emul-
sions and solid-in-liquid dispersions. This last develop-


ment has important consequences in embryology, and in
research on cancer. Bob is also a member of the Center
for Theoretical Biology.
JOHN HOWELL'S research is directed toward many
important problems in the environmental area. He is
currently performing theoretical and experimental in-
vestigations on the effects of wall growth of organisms
in biological reactors. Such effects have been shown to
be of great significance when scale-up of biological re-
actions is to be done. John is currently performing
studies on the use of certain types of biological reactors
for the production of single cell protein to be used as an
animal feed supplement, and for the treatment of indus-
trial wastes. John is offering a new graduate course in
immobilized enzyme technology, and, with the help of
Greg Vermeychuk, produced a totally new selection of
undergraduate advisement materials. John had served
as Master of the Rachel Carson College until recently,
when he left the post in order to devote full time to the
department.
KEN KISER'S research work shows a strong inter-
disciplinary orientation. He collaborates with members
of the Civil and Mechanical departments in the use of
their unique rotating models of Lakes Erie and Ontario
to characterize the spread of material and thermal pol-
lutants in these bodies of water. With members of
Mechanical Engineering and the medical School he seeks
to experimentally determine velocity profiles in the aortae
of living dogs. This work will provide information neces-
sary for the design of better artificial heart valves for
human patients. Ken is also conducting experimental
work on mixing in turbulent jets.
HARMON RAY'S interests in process modelling, optim-
ization and control have led him into many diverse fields.
He has developed rigorous quantitative descriptions for
a number of polymerization systems including copoly-
merization and heterogenous polymerization reactors.
Another major area of interest has been the modelling
and optimization of catalytic reactors experiencing cat-
alyst deactivation, and he has developed several efficient
optimization algorithms for treating these problems.
More recently, Harmon has collaborated with JULIAN
SZEKELY to apply modern optimization and control
techniques to the problems of the steel industry. In order
to acquaint the metals processing industry with these
ideas, Harmon and Julian have (for the past 3 years)
put on a 3-day intensive course entitled "Optimization in
Process Metallurgy" which has been well attended by
industrial people and professors alike. Harmon and
Julian's interest in Optimization, as applied to a number
of fields, have led to their recently published monograph
entitled "Process Optimization" (Wiley 1973). Harmon
has also been active in the field of process dynamics,
estimation and control and has contributed papers in a
number of areas. These include the control of systems
having time delays in the state, control, or measuring
device, as well as the dynamic behavior of chemical re-
actors. Harmon's research efforts in process control were
recognized in 1969 when he was presented the Donald
P. Eckman Award of the American Automatic Control
Council.


CHEMICAL ENGINEERING EDUCATION









JULIAN SZEKELY, Director of the Center for
Process Metallurgy is active both within the field of
Chemical Engineering and Process Metallurgy. He is
one of the pioneers of the application of chemical en-
gineering techniques to metals processing operations.
The co-author of two texts, Rate Phenomena in
Process Metallurgy (with N. Themelis) and Process Op-
timization with Harmon Ray, he has also edited two
volumes, Blast Furnace Technology and The Steel In-
dustry and the Environment.
Julian's research ranges from bubble dynamics, turbu-
lent flow in solidification to gas-solid and solid-solid re-
actions, and scrap-melting kinetics. Julian publishes ex-
tensively in both the chemical engineering and the
metallurgy literature and his work has been recognized
by the "Junior Moulton Medal" (British Institution of
Chemical Engineers, 1964), the D.Sc (Eng) degree (Uni-
versity of London, 1972), The extractive Metallurgy Di-
vision (A.I.M.E.) Science Award (1973) and the Mathew-
son Gold Medal (A.I.M.E.) also in 1973.


Laboratory
in the
center for
Process
Metallurgy.


S K


GREG VERMEYCHUK is extending his work on
suboptimal feedback control of systems described by
partial differential equations. He is developing new com-
putational algorithms and applying them to models of
tubular reactors with the goal of providing more effec-
tive and reliable software packages for direct digital
control installations. It is expected that this work will
extend the range of direct digital control to include more
complex systems of practical importance.
Since joining the department in September, 1971,
Greg has started to branch into other research areas.
He is collaborating with Bill Gill on a combined theoreti-
cal and experimental study of the use of specially de-
signed membranes to improve reverse osmosis systems
for desalination of water and other applications. Greg
will work with Bill in the study of mixing and dispersion
in open channel flows. This work will have great im-
portance in assessing the downstream effects of concen-
trated sources of pollution, such as industrial discharges.
Greg has also developed a new sophomore-level intro-
ductory course in chemical engineering.


TOM WEBER has developed a number of models to
describe the behavior of adsorption beds. For gas-solid
systems, one model accounts for the coupling of the heat
transfer and mass transfer effects. This model was suc-
cessfully tested using a gas mixture of ethane and helium
with activated carbon. More recently, he has turned his
attention to liquid-solid systems because of their potential
importance in waste water treatment. Both pore-and
solid-diffusion models are being explored, as well as the
possible effects of axial dispersion. Tom has collaborated
with Ken Kiser in a recent study of heat transfer in
pulsed laminar flow.
Tom is also interested in process dynamics and control.
He is carrying on some work on multivariable processes
with interactions. As an outgrowth of his teaching in-
terests in control, he has written an undergraduate text-
book, An Introduction to Process Dynamics and Control,
which will be published by Wiley-Interscience in June.
Tom also coordinates credit-free technical courses and
programs in the Division of Continuing Education.
Last, but by no means least, comes our present Acting
Chairman, SOL WELLER. Far from new to administra-
tive matters, Sol has served as Acting Chairman before,
as well as having held research management posts in
industry before joining the Buffalo faculty in 1965.
Sol's study of the supported metal and transition
metal oxide catalysts has shown that the special chemical
properties of surface ions can help to explain their
catalytic behavior and their tendency to sinter. He is
using alumina-deficient mordenite to develop a simple
picture for the catalytic action of zeolites. And he is
applying the Frank-Kamenetskii theory of ignition and
quenching at the surface of catalytic wires as a tool to
optimize activation techniques for metals. As chairman
of a U.N. committee, he is active in establishing inter-
national standard test methods for catalysts. Finally, as
a member of the Center for Theoretical Biology at
Buffalo, he is involved in planning Viking experiments
to search for the existence of life on Mars.

THE UNDERGRADUATE PROGRAM
The undergraduate program in chemical en-
gineering of Buffalo has many unusual features in
addition to the rather standard offerings which
typify such programs. Within a University-wide
framework of thirty-two courses of four credit-
hours each as a requirement for the Baccalaur-
eate degree, we have designed our program to
afford each student the maximum flexibility in
tailoring a program which suits his or her indi-
vidual needs. In addition to standard lower-divi-
sion requirements of mathematics, chemistry, and
physics, there are required faculty-wide courses
in the principal engineering sciences. The courses
in materials and engineering thermodynamics are
often taught by members of our department. The
courses in thermodynamics are worthy of note,
since the Department of Chemistry accepts these


SUMMER 1973







courses as sufficient preparation for the second
course of a two-course sequence in physical chem-
istry. The normal requirement of the first course
is waived for ChE students.
As soon as they are identified, departmental
majors are assigned faculty advisors who help
the student make the most out of his or her elec-
tive courses. Since ChE undergraduates often
enter graduate or professional programs in man-
agement, law, medicine, and other diverse fields,
the needs of different students vary widely.
Certain unique features of our undergraduate
program include the two-semester senior level
course sequence entitled Applied Chemical Engi-
neering, or simply, "ACE." In the ACE sequence,
students are exposed to detailed treatments of
ChE unit operations from a theoretical point of
view, coupled with a series of small design proj-
ects. With modifications, over the years, this
course has been quite successful, especially with
the more practically oriented students. Since the
course requires intensive preparation, it is usually
team-taught by two professors.
Undergraduates interested in environmental
problems have the opportunity to enroll in the
Rachel Carson College, a comprehensive living-
learning unit specializing in technological/en-
vironmental studies.
The students provide valuable feedback on
the degree of success of our teaching efforts in
evaluations conducted each semester by the Office
of the Provost. In such a climate, dedication to
teaching obviously flourishes.
We have had some success in encouraging
women to enter the profession. Of our 1973 senior
class of twenty there are three women.

THE GRADUATE PROGRAM
The department offers courses of study lead-
ing to both the M.S. and Ph.D. degrees in Chemi-
cal Engineering. Of the 50 students in residence
at this time, 20 are formally pursuing Ph.D. re-




f lWeller and
Howell at
informal
faculty
gathering.


Scanning Electron Microscope.
search. Up to June of 1972, 16 Ph.D. and 55 M.S.
degrees have been awarded. Of the Ph.D.'s, 6
have obtained university teaching positions, both
in the U.S. and abroad. The department expects
to award 17 M.S. and Ph.D. degrees in the 1972-
73 academic year.
Graduate research is very active, as detailed
in the section on the activities of the staff. To
speak in general terms, however, our graduate
program offers definite strengths in process
metallurgy, materials (notably polymers) and
environmental studies as well as the more com-
mon aspects of chemical engineering. These
strengths are expected to be developed further
when the department moves to the new North
Campus in 1976-77.
Graduate course offerings are many and
varied. Students are encouraged to take courses
outside the department in order to augment their
research interests and to broaden their back-
ground.
IN SUMMARY
From all that has been presented above, and
from observation of the day-to-day workings of
our faculty and students, one may characterize
the department at Buffalo as young, and prepar-
ing to enter a phase of growth.
The addition of Drs. Gill, Ray, and Vermey-
chuk, all in the past two and one-half years, has
increased the scope of departmental research.
For September 1973, Professor Eli Ruckenstein
will come to Buffalo as Faculty Professor of En-
gineering and Applied Sciences. Professor Ruck-
enstein is already interacting on research prob-
lems with three members of the department, and
will be offering courses within the department


CHEMICAL ENGINEERING EDUCATION










I classroom


INTRODUCTION TO CHE ANALYSIS


T. W. F. RUSSELL and M. M. DENN
University of Deleware
Newark, DE 19711

The transition of chemical engineering educa-
tion during the past two decades from an empiri-
cally based, design oriented curriculum to the so-
called "engineering science" approach has been
neither smooth nor totally successful. Today's
curricula have been justifiably criticized for fail-
ing to teach applications of principles, and the
new trend appears to be a "return to design." A
principle-based curriculum can be oriented to-
wards practical engineering application and pro-
vide the necessary blending of design and engi-
neering science. The resolution lies in imagina-
tive use of the introductory course in chemical
engineering, usually taught at the sophomore
level.
The sophomore course in Industrial Stoichio-
metry has changed little during the era of major
modification of upper-class undergraduate and
graduate curricula. Though "modernized" at
times by introduction of the digital computer to
assist in the solution of large problems, the course
content remains by-an-large the solution of steady
state mass and energy balances for existing pro-
cesses. Skills are haphazardly developed through
many example problems and little attention is
paid to the development of a consistent logical
approach to engineering problem solution. Recent
developments which have greatly improved and
expanded high school and university freshman
courses are ignored. The student's mathematical
skills are not adequately reinforced with practice
in engineering problems and almost no attention
is paid to his improved abilities in elementary
calculus and basic chemistry. In an attempt to
"simplify" problems for the sophomore level many
concepts, particularly in basic thermodynamics,
are introduced incorrectly and a re-learning must
take place in the courses which follow. Con-
siderations of design are never included because
the concept of a rate is usually not introduced.
The type of problem considered has little to do
with the creative aspects of traditional chemical


engineering practice or the extension of chemical
engineering skills to a broader class of problems.
The inadequacy of the traditional sophomore
course is compounded by the lack of continuity
between it and the "engineering science" courses
which immediately follow: There is a difference
in approach, type of problem, and analytical level.
The transition is a difficult one for many students,
and in 1965 the Chemical Engineering Depart-
ment at Delaware initiated a program to study,
modify, and if necessary, reorganize the intro-
ductory course in the curriculum. This study has
resulted in our present "Introduction to Chemical
Engineering Analysis" course, which meets the
following three objectives:
To reinforce, amplify, and apply in an engineering
environment the material covered in basic chemistry,
physics, and mathematics.
To develop the basic skills needed as a sound founda-
tion for upper level courses.
To develop an early appreciation for design by involv-
ing the student in simple but significant chemical
engineering design problems.
Because of the considerable discussion in the
profession about the proper direction for under-
graduate education it seems to us that it is useful
to recount our approach and the evolution of the
course and our thinking. We do this because what
seemed to us and many colleagues to be obvious
remedies for the deficiencies noted above were not
successful at all, and the final course outline
differs considerably in content and tone from our
first attempts. The course in its present form is a
result of some five years experience teaching the
subject to sophomore students in both the regu-
lar and extension programs. Some portions of
the material have also been used with engineers
and chemists who participated in AIChE con-
tinuing education courses at both the national
(Today Series) and local levels. For three years
we taught the course together at the same hour,
each with a section of about twenty-five students.
The material was coordinated on a lecture to
lecture basis and its impact on students was
evaluated after each lecture and again after each
major topic had been covered. Substantial stu-


SUMMER 1973
























T. W. Fraser Russell received the Bachelors and Masters
Degrees at the University of Alberta. He worked as a
research engineer for the Research Council of Alberta
and as a design engineer at Union Carbide Canada be-
fore receiving the PhD ('64) from Delaware. He is on
leave for 1972-73 at ETH Zurich. Professor Russell re-
ceived a University of Delaware Excellence in Teaching
Award in 1968. His primary research interest is on two
phase system analysis and design, and he has a book in
progress in the area. (left)
Morton M. Denn received the Bachelors Degree at Prince-
ton University and the PhD (64) at Minnesota. He has
been at the University of Delaware since 1964 and was a
Guggenheim Fellow in 1971-72. Professor Denn's major
research areas are the fluid mechanics and rheology of
polymeric liquids and optimization and optimal control.

dent feedback has been received, and several
undergraduates and graduate students have
worked with us for extended periods in evalua-
tion and revision. This method of teaching has
allowed us to experiment with various ways of
organizing and presenting the material, and we
feel that we have found a very effective way to
introduce students to chemical engineering.
In the first year, we taught a slightly modified
industrial stoichiometry course, followed by an
applied mathematics course which concentrated
on solutions of various types of differential equa-
tions encountered in chemical engineering. This
latter course replaced the more classical course
in differential equations taught by the mathema-
tics department. It quickly became apparent that
the major problem the student faced was develop-
ing the equations that described a particular sit-
uation. Since he did not feel adequately trained
in this skill, there was a strong tendency to sep-
arate the mathematical description and its be-
havior from the situation which it described.
This had two equally undesirable effects. Some
students concentrated on the mathematical mani-
pulation and thought little about the relationship


Today's curricula have been
justifiably criticized for failing
to teach applications of principles
and the new trend appears
to be a "return to design."

to the physical situation, while others became
confused as to the role of mathematics and tended
to dismiss the material as being an academic
exercise unrelated to physical reality. (This is
not unlike what has happened outside the Uni-
versity in professional practice. It has been our
experience in continuing education activities that
the greatest number of engineers who profess a
need for "more mathematics" are really in need
of a better understanding of model development).
In an attempt to overcome these serious prob-
lems and also to revise what we considered to be
inadequate or incorrect presentation in the stan-
dard stoichiometry course, we decided to restruc-
ture both courses and to concentrate on develop-
ing the skills which would enable the student to
see clearly the relationship between mathematical
description and physical reality. We attempted
to meet this goal the first time we taught the
integrated course by developing mathematical
models for a series of increasingly complex physi-
cal situations. This "case study" approach was
moderately successful and, although it did not


principles No Yes Matihernatical
foll""e"'ited o Enough equations? M
Fully exploited model


Constitutive
relation
Fig. 1. Model development for any physical situation.

CHEMICAL ENGINEERING EDUCATION










meet our goal of developing a systematic pro-
cedure for model development, the students did
develop some facility for seeing the proper role
of mathematics in the study of engineering.
The logic procedure outlined in Fig. 1 was
introduced on the third try at the course. We
emphasized this time the need for experimental
verification of constitutive assumptions, as dis-
tinct from the application of conservation prin-
ciples. This emphasis on the role of experiment
in engineering is, paradoxically, the key to a
student's understanding of the role of mathe-
matics. At this time we oriented the course to-
wards liquid phase reactor performance and con-
centrated on a complete study through design
using a single conservation principle (mass)
before introducing a second. We also found as
we progressed through the third year that it was
necessary to drop some of the mathematical skills
we had stressed so that the more important as-
pects of analysis could be properly covered. We
eliminated material on differential equations with
variable coefficients and reduced our discussion
of the Laplace transform.
An initial review of the third year's classroom
experience produced a course outline similar to
what now exists and pointed out a need for still
more emphasis on the experimental aspects of
engineering and the use of the mathematical de-
scriptions for simple design. Thus we decided once
more to reduce the mathematical content, result-
ing in total elimination of the Laplace transform.
(Students with the need for such mathematical
skills learn them in the senior Process Dynamics
and Control course).
We concentrated in our fourth year on better
organization of the material with respect to the
model development step in analysis and we reor-
ganized, using more experimental data, the
methods by which constitutive relationships were
employed. Our goal was to make sure that all the
relevant material normally covered in the stoichio-
metry course was introduced in a rational and
consistent manner. Since then the emphasis has
been mostly on polishing and minor changes.
The sophomore courses, ChE. 230 and 231,
are taught for two shortened semesters, totaling
twenty-seven weeks. The relationship of these
sophomore courses with other ChE courses at the
University of Delaware is shown in Table 1. Since
our students are not required to take a separate
course in differential equations, but rather study
the subject as part of the chemical engineering


Freshman
Year


TABLE 1 Basic Departmental Course Structure

Introduction to the
art and science of engineering

EG 125
(Introduction to Engineering)
EC 130
(Introduction to Engineering Research)


Sophomore Aquisition of the basic
engineering skill of Analysis--
Year How to proceed from experiment to design


Junior
Year









Senior
Year


ChE 230, 231
(Introduction to Chemical Engineering
Analysis)


The basic phenomena are studied from
an engineering viewpoint
Applied Physical Applied Chemical
engineeringg Sciences Engineering Sciences
ChE 341 ChE 325, 332
(Fluid Mechanics) (Thermodynamics
ChE 342 and Kinctics)
(Hoat and Mass
Transfer)
ChE 345 (Chemical Engineering Lab)


Skills are integrated by studying complex
engineering problems in class, in the labo-
ratory, and by individual thesis.
ChE 432 (Chemical Process Analysis-Design)
ChE 443 (Transfer Operations)
ChE 445 (Chemical Engineering Laboratory)
ChE 473,474 (Senior Thesis)
ChE 401,466,etc. (Electives in Control,
Pollution Abatement, Polymer Processing,
Chemical Economics etc.)


analysis course, a one-semester course employing
a major fraction of our outline is possible. Em-
phasis is on the analysis of liquid phase systems,
for this enables the student to treat meaningful
design problems during his first semester of engi-
neering study. He takes this course concurrently
with the final semester of calculus and two semes-
ters of physical chemistry. The topics covered
follow our book, Introduction to Chemical Engi-
neering Analysis, Wiley, New York, 1972.

INTRODUCTION. We start with a brief description of
three chemical engineering problems, where the emphasis
is on "putting together the pieces." We discuss a typical
chemical process, the manufacture of ethylene glycol; the
operation of an artificial kidney; and the design of a bio-
oxidation reactor for sewage treatment. This introduces
the idea of reactor, separation process, etc. We then turn
to a detailed study of the analysis process, which we
define as follows:

1) Description of a physical situation in mathematical
symbols.


SUMMER 1973









Student response has been excellent ...


2) Manipulation of the mathematical model to deter-
mine expected behavior of the physical situation.
3) Comparison of the model with the true physical
situation.
4) Careful study of the limitations of the mathema-
tical model.
5) Use of the model for equipment design and pre-
diction of performance.
ANALYSIS. Several days are spent discussing the basic
concepts involved in analysis and the total analysis
process is described by means of the simple example of
an emptying tank.
The model development step is illustrated using real data
to develop a relationship between outflow and height of
liquid (the orifice equation). Next the laws of conserva-
tion of mass, energy, and momentum applied to a
well-defined control volume are shown to be the basic
source from which mathematical descriptions are de-
rived. A careful distinction is made between general
conservation principles, universally applicable, and spe-
cific constitutive relations applicable only to certain
situations. The necessity of experimental data for the
development of constitutive relationships is stressed and
dimensional analysis is introduced as one means for
planning this needed experimental program. A series of
logical procedures is developed to show the student how
mathematical descriptions for a physical situation are
developed. The ultimate logic is shown in Figure 1.
NON-REACTING LIQUID SYSTEMS. Model develop-
ment for well-mixed tank-type liquid systems in transient
and steady state isothermal operation is illustrated in
detail, with an experimental check of the perfect mixing
assumption and a critical appraisal of the role of the
density-concentration constitutive equation. The purpose
is to give the student practice in the model development
step of analysis with simple problems, so that he can
clearly see the relationship between the mathematical
description and the physical situation. The simpler aspects
of basic calculus are employed to determine model be-
havior and, as a secondary aim, practice with manipula-
tion of the mathematical description to determine model
behavior is stressed. As one example to meet this latter
aim we exploit the draining tank problem and design a
simple feed back controller. This also shows the student
something about the design aspect of analysis.
REACTION RATE. Reacting, well-stirred single phase
liquid systems are studied next. The reaction rate arises
naturally in the component mass balance and reasonable
phenomenological forms are deduced. Emphasis is on the
use of batch reactor data to determine the validity of
constitutive assumptions for the rate and to find the
values of the parameters. Real batch data are used in all
cases.
REACTOR DESIGN. The steady state model equations for
a well-stirred continuous flow reactor are used for two
design problems. In the first, a reactor is sized to meet
production requirements for a single, irreversible first
order reaction, taking capital and operating costs and


depreciation of the reactor and separation unit into
account. (The economics are obviously simplified). The
other is the problem of sizing a reactor to obtain a
required distribution of mono-,di-, and tri-ethylene glycol
(a process introduced earlier). The sophomores take
this material nicely in stride and take pride in their
ability to use the mathematical descriptions. We intro-
duce the plug flow tubular reactor here for comparison.
MASS TRANSFER RATE. Two-phase, well-stirred sys-
tems are studied to introduce the concept of mass trans-
fer and to further develop modeling skills. The rate of
inter-phase mass transfer arises naturally in the com-
ponent balances and, like the reaction rate, reasonable
phenomenological forms are deduced. Batch data are used
to study the approach to equilibrium. For a continuous
flow process the equilibrium stage is shown to be a good
approximation for typical mass transfer data. Stage
efficiency and reaction in a two-phase system are briefly
examined.
STAGED PROCESSES. Multistage solvent extraction is
studied analytically and graphically (McCabe-Thiele).
Calculations are done for minimum solvent requirements
and numbers of ideal stages. The triangular diagram is
used for single stage calculations. The material nicely
illustrates the use of graphical techniques in the model
behavior step of analysis.
This is roughly the end of our first semester, together
with some mathematical topics as needed, including least
squares fitting to data. The student deals routinely with
dynamical situations as well as the steady state, but he
never requires mathematical concepts not already used
in his calculus course. The interplay between laboratory
experiment (measuring reaction rates, mass transfer co-
efficients, equilibrium constants, etc.), mathematical
modeling, and engineering design calculations is brought
home. This works because there is simply no easier
practical problem in chemical engineering than the sizing
of a liquid phase reactor with uncomplicated chemistry.
The student is motivated to go on to engineering science
courses and learn, for example, why a mass transfer
coefficient is of a given order, or how to estimate one in
the absence of an experiment. Most important, he has
learned a systematic approach to solving problems.
At this point we turn to non-isothermal systems. In
some curricula it might be desirable in a one semester
course to skip some or all of the material on mass trans-
fer processes and include some of the non-isothermal
material. Emphasis is on the operational definition of
thermodynamic quantities and, to avoid the complication
of compressibility, liquid phase systems are studied first.
CONSERVATION OF ENERGY. Internal energy is in-
troduced and the principle of conservation of energy
applied to a flowing system. The square root orifice equa-
tion is derived using the energy balance. Internal energy
and enthalpy are related to temperature by defining the
heat capacity. Partial molar enthalpy is defined and used
to define the heat of solution and the heat capacity of
a mixture. Students are prepared to deal with partial
molar quantities at this level because it comes sufficiently
soon after seeing partial differentiation in the calculus
course.


CHEMICAL ENGINEERING EDUCATION









The student is continually referred back to relevant sections of his calculus and chemistry texts, developing, in
his eyes, a logical continuity between his basic science courses and creative engineering. Physical
chemistry laboratory experiments are often discussed in our classroom.


MIXING AND HEAT TRANSFER. In parallel with the
isothermal system development, we model non-reacting
liquid systems. Consideration of temperature effects in
batch mixing is followed by construction of the enthalpy-
concentration diagram and graphical solution of the same
problems. This is then repeated for steady state con-
tinuous mixing. The analysis of mixing is done rigorously,
using partial molar enthalpies, for otherwise the student
learns incorrect procedures which ensure the wrong
answer when working with multi-phase systems. Heat
transfer between adjacent chambers leads naturally to
the rate of heat transfer and definition of the heat trans-
fer coefficient. Area and flow rate calculations are carried
out for cooling a tank by a jacket and a coil.
REACTING LIQUIDS. Reacting liquid systems are dealt
with after the student has seen how partial molar quanti-
ties are used in the simple mixing situation. The heat of
reaction is defined in terms of the partial molar enthalpy
and the batch reactor equations derived which demon-
strate how to measure it. Calculation of the heat of
reaction from tabular data is discussed. The Arrhenius
temperature dependence of reaction rate is demonstrated
and the transient adiabatic batch reactor equations for a
single reaction are integrated using numerical quadrature.
(This still requires only the calculus course as prepara-
tion.) The energy balance for a continuous flow stirred
reactor is derived. A numerical solution of the steady
state is obtained, and the qualitative behavior of the non-
isothermal reactor is discussed using the Van Heerden
slope argument and phase plane construction via the
method of isoclines. The non-isothermal tubular reactor
is touched upon very briefly. By this point the student is
becoming quite skilled in making his mathematical skills
work for him to understand physical problems.
TRANSIENT REACTOR BEHAVIOR. We include this
material as the practical application for linear differential
equations, which are included in the course. The section
can be omitted without serious loss. The reactor equa-
tions are linearized in the neighborhood of the steady
state to obtain a linear second order system with constant
coefficients. Applications are to the stability of the steady
state, response of a stable system to a feed disturbance,
and proportional feedback control by coolant flow rate
adjustments. Students have no trouble with the notion
of linearization. They have seen a number of examples
in which the physical problem is severely limited in order
to obtain a tractable mathematical model, and they
recognize the virtue and limitation of such a trade-off.
GAS SYSTEMS. To show that analysis skills can be
readily extended we deal with gas systems as a final topic.
Non-reacting and reacting batch systems are re-examined
with the compressibility term retained in the energy
equation. Constitutive equations are introduced for the
ideal gas and several non-ideal gases and the compres-
sibility chart and mixing rules are introduced.


MATHEMATICS. At appropriate times we cover numeri-
cal methods for solving algebraic equations, and, towards
the end of the course, analytical solution of linear, non-
homogeneous differential equations with constant co-
efficients and elementary numerical solution of nonlinear
differential equations.
Student response to the course has been excel-
lent. We feel, with some pride, that this is at least
in part a reflection of the course content and
organization, particularly chemical engineering
courses seem to the student to be a natural out-
growth of the analysis course. There is another
factor, however, which helps considerably. The
student is continually referred back to relevant
sections of his calculus and chemistry texts, de-
veloping, in his eyes, a logical continuity between
his basic science courses and creative engineering.
Physical chemistry laboratory experiments are
often discussed in our classroom. This blending
is in stark contrast to the nearly total discontinu-
ity which existed under the old program.
Colleagues unfamiliar with the details and
student performance often express concern over
the level of material and wonder whether sopho-
mores can really handle it. Our emphatic "yes"
supported by formal AIChE student chapter and
Student Government Association evaluations, is
most easily justified by a related fact. Last year
we introduced a course for non-majors based on
our first semester course. We will discuss that
course in detail at another time, but it is quite
similar in content and level to the first semester
course for chemical engineering majors. We have
had participation from students to biology, chem-
istry, economics, home economics, and secondary
education, among others, some of whom have
studied no chemistry. Registration went from
eight in the first year to thirty-two in the second,
and the course is recommended now by the chem-
istry department for its undergraduate majors.
The students rated the course 4.7 out of a possible
5.0 in the SGA evaluation. It is clear from the
performance of the non-engineers that our engi-
neering procedures for problem solving are appre-
ciated by a much larger portion of the student
body than we originally anticipated. When the
concepts can be grasped by non-majors, it is evi-
dent that the material belongs at the sophomore
level in a Chemical Engineering curriculum.


SUMMER 1973









*1-t16haip


THE UNDERGRADUATE CHE LABORATORY*


H. S. FOGLER', A. J. PERNA2, and
F. H. SHAIR3


The laboratory workshop format consisted of
a number of speakers each discussing a particu-
lar aspect of a laboratory. The papers presented
can be classified in four categories: 1) the phi-
losophy and objectives of the laboratory, 2) com-
puter aided laboratory instruction, 3) types of
laboratories and experiments, and 4) different
approaches and instructional techniques. To
assess the attitudes of laboratory instruction
along with current and future trends in each of
the above categories, a 10-page questionnaire was
prepared and mailed to over 50 chemical enge-
neering departments (primarily those who had
faculty members registered for this workshop) in
the U. S. and Canada and to a significant number
of industrial contacts.

I. PHILOSOPHY AND OBJECTIVES
The major results of the survey were dis-
cussed in the first paper of the session by H. S.
Fogler. The consensus indicated that the most im-
portant goals of the laboratory were to
* Demonstrate or reinforce principles or phenomena
discussed in class,
* Give the students practice in planning and interacting
with the experiment,
* Develop the students' interest in experimentation,
* Develop a proficiency in technical report writing, and
* Expose the student to open-ended experiments of a re-
search or design nature.
Information on the philosophies of the laboratory
at various universities along with ideas about
experiments which impart a sense of learning to
the student and leave him with a sense of accom-
plishment were also summarized in this paper.
The results of one question, when averaged,
showed the following allocation of the student's
time currently spent on a given experiment.

1. The University of Michigan, Ann Arbor, MI 48104.
2. Newark College of Engineering, Newark, NJ 07102.
3. California Institute of Technology, Pasadena, CA
91109.


15% of the time should be spent in preparation for the
experiment
30% should be used for setting up and carrying out the
experiment
25% should be spent on computation and analysis for
the raw data
30% should be used for writing the report on the ex-
periment.
Many felt that too little time was currently
being spent on giving the students practice at
planning and interacting with the experiment to
learn the process of experimentation, i.e., the
technical and managerial skills required to carry
out effective experiments. In the future, it is
hoped that most laboratories will provide the
student with the opportunity to plan meaningful
experiments and experimental programs in which
the outcome is not known or is uncertain and in
which one must allow for contingencies.
Also discussed in the first paper were a few
techniques used at The University of Michigan
to complement the standard laboratory exercises
in order to increase the student's capabilities for
planning effective experiments. In particular, the
use of guided design instruction in the synthesis
of experimental projects at the sophomore level
has proven quite effective. Here, a group of 3-4
students (1) define and develop the need for an
experiment which they would like to perform, (2)
state the constraints on the experimental pro-
gram (3) determine the key or critical measure-
ments to be made, (4) suggest methods of pro-
cessing and analyzing the data, (5) support alter-
nate approaches to various segments of the proj-
ect, (6) suggest possible outcomes and means of
evaluating the effectiveness of the programs.
Each group receives feedback from the instruc-
tor at various stages of the planning and then
gives an oral presentation and defense to the
other groups at the end of the semester.
Methods of implementing the open-ended
approach laboratory were presented by R. Clift
and 0. M. Fuller. They described a ChE Labora-
tory course at McGill, in which a special format
*Report on the Undergraduate Laboratories Workshop at
the ASEE Summer School in Boulder, CO 1972.


CHEMICAL ENGINEERING EDUCATION






















Shair


Fogler


called the Evolutionary Laboratory has been de-
veloped in order to place emphasis on the process
of experimentation itself. The distinctive features
are specialization of the staff for optimal use of
teaching personnel, and the conference period for
rapid feedback and evaluation.
Work on each unit of apparatus is directed by
an experiment controller (EC) who acts both as
technical expert and teacher. The EC has suffi-
cient freedom in planning so that he may, for
example, direct a logically connected sequence of
experiments rather than repetitive exercises. Fol-
lowing each laboratory exercise, the students have
a conference with the EC which consists of an
oral report, a teaching session, and an occasion
for feedback on instructions and apparatus. The
conferences permit flexible planning and evolu-
tionary changes in the exercises. The teaching of
experimentation requires, among other things, a
description of the process in terms of observable
behaviors and a methodology for planning ex-
periments. For this purpose, the McGill program
offers a description in terms of instructional ob-
jectives and an extension of PERT for planning.
In addition to comments on the laboratory
received from industry on the questionnaire, in-
formation was gathered and presented by Drs.
C. C. Zimmerman and D. N. Burdge of Marathon
Oil Company who view the laboratory as a tool
to increase the student's problem solving capabili-
ties through experimentation. They reinforced
earlier presentations suggesting that greater
emphasis be given in the laboratory to problem
definition and analysis and to experimental plan-
ning. This is to help insure that the student or
employee may learn to decide which measure-
ments will be meaningful and not to carry out
unnecessary experiments whose results could have


been obtained by other means, such as a combina-
tion of reasoning and calculation. They encour-
aged greater development of the student com-
munication skills primarily through report writ-
ing but also through oral reports to the instruc-
tor. It is interesting to note that while only 50%
of the universities returning the questionnaire
stated that report writing was a major objective
of the laboratory, every industrial reply suggested
that improvement in the students report writing
should receive major attention.

II. TYPES OF LABORATORIES AND EXPERIMENTS
F. H. Shair reported the survey results con-
cerning the attitudes expressed by ChE faculties
towards the laboratories in chemistry and physics
which are required by students who enroll in the
ChE curriculum. Generally the ChE faculty were
satisfied, but certainly not enthusiastic about the
chemistry laboratories. On the other hand, the
ChE faculty generally expressed moderate dissat-
isfaction with the physics laboratories. Over half
of the persons answering the questionnaire stated
that they believed their required physics labora-
tories to be of little value in aiding their students
in developing important laboratory techniques, in
helping their students to analyze experimental
error and uncertainty, in helping their students
develop report writing, in helping their students
develop oral presentations, and in helping their
students formulate an experimental path aimed
at obtaining desired answers with the least effort.
The merits of the undergraduate laboratories de-
veloped by E. C. Stone and D. W. Skelton at
Caltech discussed in some detail.
Professor Shair also described a ChE inte-
grated concepts and laboratory course which has
been given during the last five years at Caltech.


SUMMER 1973








The fundamentals of ChE are emphasized along
with both oral and written presentations. The
laboratory experience involves open-ended proj-
ects which are also of interest to someone outside
of Caltech. Recent experimental topics involved
the internal combustion engine, the melting of
icebergs, the spreading of oil slicks, the decay of
ozone within buildings, transport across pul-
monary membranes, and transport across artifi-
cial kidney membranes. Students participate in
the planning as well as in the conducting of ex-
periments. Several projects are in some stage of
being published in the open literature. Exams
are given in the form of scenarios. The most im-
portant aspect for course update and improve-
ment involves the recycle of the top 10% of the
class into teaching assistants during the follow-
ing year.
Discussed by A. J. Perna were those results
of the 10-page questionnaire relating to the Unit
Operations Laboratory. A summary of the over
thirty schools responding showed that:
* All had either conventional Unit Operations Labora-
tory or a Transport Laboratory;
* Laboratory experience ran the gamut from a three
level approach (sophomore-junior-senior) to only
a senior year (majority) course;
* Laboratories were primarily hardware rather than
computer oriented;
* In general, laboratory experiments were a blend of
pilot plant size and transport size;
* Integrated Lab-Theory courses were rare with only
approximately 18% of the schools using this
approach;
* All schools have experiments designed to cover the
areas of Heat, Mass and Momentum Transport
in their Unit Operations Laboratory, but some
schools also have incorporated experiments in
kinetics, thermo and process control and dynam-
ics in the lab;
* In general the lab improvements have been in the
areas of instrumentation, open-ended experimen-
tation, and reduced workload.
One important factor which came out of the sur-
vey was that the laboratory has become an area
for exposing the students to concepts not taught
in the classroom and that it is an extension of his
learning process and not completely integrated
with the material presented in theory type
courses.
R. D. Williams described a one hour chemical
reaction engineering laboratory currently being
used at The University of Arizona. In this labora-
tory the student is exposed to a number of differ-
ent types of reactors used in homogeneous liquid


Many felt that too little time was spent
on giving students practice at planning and
interacting with the experiment ...



phase reactions, in catalytic heterogeneous re-
actions and in non-catalytic heterogeneous re-
actions. A number of methods of data collection,
ranging from direct sampling and titration or
gas chromatography to direct temperature and
pressure measurements, are illustrated in the
course along with different methods of data an-
alysis. The students could use these reactors to
carry out reactions whose rate laws have been
reported in the literature or to study reactions
whose kinetics have not been reported.
An alternative to the weekly laboratory in the
form of a three-week intensive course was pre-
sented by G. B. Williams and J. H. Hand of The
University of Michigan. In this course, which is
offered at the end of each winter term, the stu-
dent has essentially an entire day to complete the
experiment and write his report. Consequently he
is not under the usual pressure to get the experi-
ment working and finished within as soon a time
as possible in order to rapidly go on to other
course assignments. In the intensive course there
is adequate time to modify and experiment with
the equipment, and also time to profit from rou-
tine difficulties and breakdowns of the equipment.
While the faculty and students are equally en-
thusiastic about conducting the course in this
manner, the only two serious drawbacks appear
to be centered around finding housing for the
students for only three weeks after the end of
the term and the lab's interference with some
summer jobs and summer school.
R. M. Hubbard presented a pilot plant oriented
experiment which students undertake as a final
experiment in the ChE laboratory at the Uni-
versity of Virginia. The experiment is multi-
purpose and forces students to work as a team
to take data, make material balances on a process
as soon as data are obtained, and to experience a
continuous operation such as might be encoun-
tered later in industry. A small operating chemi-
cal plant produces hydrogen and carbon dioxide
from the catalytic decomposition of a vaporized
methanol-water mixture at 300'C and atmos-
pheric pressure. The students operate the plant
in shifts for most of a normal day and acquire
enough data to carry out at least two complete
material balances per shift.


CHEMICAL ENGINEERING EDUCATION









III. COMPUTER AIDED LABORATORY INSTRUCTION
D. E. Seborg described the computer-aided
student laboratory which he and D. G. Fisher
have developed during the last five years at the
University of Alberta. The computing facility in-
cludes an EAI 590 hybrid computing system
plus an IBM 1800 digital computer which oper-
ates in a multi-programmed, time-shared mode
and allows several research workers and student
laboratory groups to have simultaneous, open-
shop access to the real-time and background com-
puting facilities. Typical real-time applications
include control of pilot-plant processes, automa-
tion of analytical instruments, and student
oriented experiments designed to demonstrate
particular hardware and/or software features.
It was stressed that when properly used, the
computer can take over the time consuming
routine tasks and let the student concentrate on
the important, fundamental concepts of the ex-
periment.
R. A. Schmitz described the on-line computing
facility for undergraduate instruction which he
has developed during the last three years at the
University of Illinois. The system utilizes a time-
sharing IBM 1800 computer in conjunction with
an undergraduate process dynamics and control
laboratory. The apparatus connected to the com-
puter constitute simple closed-loop systems for
studies of mathematical modeling and direct digi-
tal control. Students using the system must write
a FORTRAN program to handle the collection of
data, the sending of feedback signals and any
calculations involved in the data processing. The
system also provides for the connection of an EAI
580 analog computer to the digital machine so
that the computer control of complex systems
may be simulated. The facility is being employed
in a required undergraduate course on process
dynamics and control and in an undergraduate
projects course.

IV. DIFFERENT APPROACHES AND INSTRUCTIONAL
TECHNIQUES
An integrated theory-laboratory course ap-
proach was described by R. R. Furgason of the
University of Idaho. The approach is to block
out from four to six hours per week for a sched-
uled three credit course and have the class meet
in a lecture mode for several weeks followed by
one or two weeks of class devoted to laboratory
experimentation. This allows the laboratory to
be utilized whenever appropriate rather than on


An integrated theory-laboratory
course was described . .. This allows
the laboratory to be utilized
when appropriate rather than
a fixed schedule.

some fixed schedule. The main advantage is the
excellent coordination between theoretical and ex-
perimental phases of the class with the laboratory
neither leading or lagging the course. The dis-
advantage is primarily logistical in terms of class,
manpower, and scheduling.
The integrated laboratory-lecture approach is
being carried out on a much larger scale at Wor-
cester Polytechnic Institute, where it encom-
passes the entire curriculum. Professor I. Zwiebel
discussed the WPI project approach in which
courses are viewed as elective tools to build the
foundations for completing the students two
major projects, which are the primary require-
ments for graduation along with a competency
examination and a humanities minor. Many proj-
ects are inter-disciplinary in nature and require
a team of students (e.g., a civil engineering-
chemical engineering, etc.) each with his particu-
lar responsibility, working together to obtain a
solution. Special projects, sponsored by a Sloan
Foundation grant, run through about 1 1/3 cal-
endar years during which time the student's time
is divided equally along the following four seg-
ments of the project: preparing a proposal of
the project plans, executing the plans, analyzing
the results, and preparing written and oral re-
ports. The WPI project approach offers a sig-
nificant alternative to the conventional engineer-
ing programs.
J. 0. Maloney and G. M. Kortman of the Uni-
versity of Kansas presented material on two in-
structional laboratory units. The first was con-
cerned with an experiment in unsteady-state-cool-
ing, while the second unit treated the determina-
tion of binary vapor-liquid equilibrium data
using an Othmer still. Especially developed for
inexperienced instructors, each unit contains
sufficient material that the instructor, after read-
ing it and doing the experiment once or twice,
would have adequate control of the experiment
and would be able to estimate the validity of
student results. Each unit provides the following
information: equipment description, experimental
procedure, extensive data, calculations, computer
programs, error analysis, and suggestions for
modification of the experiment to achieve variety.
(Continued on p. 135)


SUMMER 1973










.1ectwe .%emanondataon


BERNOULLI'S EQUATION WITH FRICTION


NOEL DE NEVER
University of Utah
Salt Lake City, UT 84112

This demonstration shows examples of flows
in which inertial effects are greater than fric-
tional effects and the converse. These are ex-
plained in terms of Bernoulli's equation with
friction.

APPARATUS
The apparatus consists of:
1. A one-gallon solvent can, into which a 14" IPS
coupling is soldered near the bottom.
2. A one-foot length of 1/" IPS pipe with five 14"
OD holes drilled in it on 2" centers. These holes are all
aligned on one line in the pipe surface, parallel to the
pipe axis. Both ends of the pipe are threaded.
3. Same as No. 2, except that into each of the five
holes a �" long piece of /4" OD copper tubing has been
slipped and soft-soldered in place.
4. A piece of 1", rod, 12" long.
5. A 1,4" IPS pipe cap.
6. A short length of rubber tubing.
7. One gallon of water thickened with 1.0 wt%$
Methocel 4000, estimated viscosity 100 to 150 cp.

DESCRIPTION OF DEMONSTRATION
1. The instructor sets the can on the lab bench over
a sink, with part No. 3 inserted in the coupling and the
end of No. 3 covered with the cap (No. 5). He shows it
to the class, describes it to them, and tells them he is
about to fill the can with water. He asks them to predict
which jet from the pieces of tubing will rise the highest.
After taking a poll of the class, he fills the can (using
the rubber hose). The water jet squirts highest from the
tube farthest from the can and successively lower from
the tubes nearer to the can.
2. The instructor then removes the cap from the end
of the pipe, inserts the rod, replaces the cap, and tells
the students that he will again fill the can with water.
He again asks which jet will go highest and records the
results of his poll. He then fills the can with water. This
time the water squirts highest from the tube nearest the
can.
3. The instructor removes the rod from the tube and
tells the students that he is about to fill the can with
the methocel solution. Again he takes an opinion poll on
which jet will go highest. He then pours the solution into
the can. The jet nearest the can squirts highest, but none
of the jets squirts as high as in demonstration No. 2.


4. The instructor then removes part No. 3, rinses the
can, and replaces part No. 3 with the pipe which has only
holes (part No. 2). He tells the class that he is going to
fill the can with water and again quizzes them as to which
jet will go highest. After recording the predictions, he
fills the can with water. This time there is a hump-shaped
distribution of heights, with the highest in the middle.
The streams are very unequal in width, with the stream
nearest the can the thinnest and the far stream the
thickest. The streams are not vertical, as before, but
leave the holes at an angle away from the can, with the
stream nearest the can about 100 from the vertical and
the stream farthest from the can about 30� from the
vertical. It is also observed that each of the streams
uses only part of the hole to exit through, and that part
is the part farthest from the can. The near hole issues a
stream which fills about one fifth of the hole area; this
fraction grows to about three fourths at the far hole.
5. The instructor explains the foregoing experimental
results.

THEORY
For the first three demonstrations with the
fluid rising through the small vertical tubes, the
flow (and, hence, the height to which each jet
rises) depends only on the static pressure at the
base of the vertical tubes. The sharp right-angle
turn which the fluid makes entering these tubes
prevents any of the horizontal momentum of the
fluid from being converted into vertical momen-
tum.
To find the pressures at the base of these
tubes, we apply Bernoulli's equation:

A + gz + = - - - F ()
Here states 1 and 2 are chosen as shown in
Figure 1.

COPPER
TUBES I
Lo . I fCAP
FLOW n',{


PIPE


Figure 1.


CHEMICAL ENGINEERING EDUCATION























W t~iS
Noel de Nevers earned his BSChE at Stanford and
his PhD at the University of Michigan, with a year out
in between to be a Fulbright exchange student at the
Technical Institute in Karlsruhe, Germany. He spent five
years with what is now Chervon Research and Chevron
Oilfield Research, before joining the faculty of the Uni-
versity of Utah. He spent Academic 1971-72 on leave,
working for the Office of Air Programs of the Environ-
mental Protection Agency. He is the author of a text-
book on Fluid Mechanics, and editor of a book of readings
and discussions on Technology and Society.

From 1 to 2 there is no change of elevation or any
pump work done on the system, and V, is zero; so
p - P V2
2 - ' 1 = - F (2)
p 2
Substituting for F from the Fanning friction fac-
tor equation (1) and solving,
2

Equation 3 indicates that if 4f L/D is less
than 1, the static pressure at 2 will be greater
than at 1; and, if 4f L/D is greater than 1, the
static pressure at 2 will be less than at 1. Thus,
by adjusting the value of 4f L/D, one can cause
the water to squirt highest from either the far-
thest or nearest tubes.
This analysis is not restricted to the two end
holes. It can be applied to holes n and (n+-1),
yielding
P P V2 V2
n + 1 .n + n 1 - s4f L +(4)
P P 2 Dj DI 2
Here V, is always greater than Vn,+i; so, if f - 0,
P,,+i is always greater than Pn. Thus, for any
two holes, the relative jet heights are determined
by the value of (1 - 4f L/D) between them.
In experiments run as described above, with
the can held full of water so that the flow was at
steady state, it was found that, with no rod in
the pipe, the flow rate out of the farthest tube was
1000 cc/min; the Reynolds number in the pipe


just upstream of it was about 104. If we accept
the value of e for galvanized pipe from Perry'
as 0.006 inches, then we can read f=0.012, which
makes 4fL/D equal 0.27. We would expect the
fluid to squirt highest from the farthest tube, as
it does.
In a similar experiment, with the 0.25" OD
rod in place, it was found that the flow rate from
the near tube was about 550 cc/min. By using
the hydraulic diameter, as shown in Perry', we
can calculate the Reynolds number as 2 x 104.
Using the same absolute roughness as before
yields f=0.018 4f L/D = 1.25. This indicates that
the fluid would squirt highest from the nearest
tube, as it does.
Raising the water viscosity has the same effect
as inserting the rod. The flow is laminar, and the
friction factor is proportional to the viscosity.
For the thickened water, the friction factor is
large enough that 4f L/D is greater than one;
and the water squirts highest from the hole near
the can.
The whole subject of flow in this type of mani-
fold has been reviewed by Acrivos et al.2
The fourth demonstration is much more com-
plicated to explain than the first three because
there is no simple, one-dimensional representa-
tion of this flow. If we had placed a pitot-type
tube in each of the holes, with its exit vertical,
we would expect that from each hole the jet
would have risen the same amount if friction
were negligible. This result would have been the
same, even if the various pitot-type tubes were
of different diameters. If, however, we had tilted
the exits of these pitot-type tubes at differing
angles to the vertical, the heights of rise of the
jets would not have been equal because, at their
highest points, the jets would have had varying
kinetic energies in the horizontal direction.
In the fourth demonstration, the fluid forms
its own pitot tubes. The wall thickness of the pipe
is only about one third of the hole diameter, so
the fluid can turn through the hole without losing
all its horizontal momentum. The interesting
thing here is that, the faster the fluid is flowing,
the greater is the angle through which the fluid
must turn to exit; so the fastest-moving fluid
exits nearest the vertical. One may look at this
another way by saying that the fluid builds up a
turning vane for itself, made up of stagnant fluid
trapped in part of the orifice.
This conversion of horizontal to vertical mo-
mentum is not perfect, so the jet nearest the can


SUMMER 1973









does not rise as high as it would if the conversion
were perfect. As we proceed out the pipe, we see
two conflicting effects producing the hump-shaped
distribution:
1. The increasing efficiency of the "turning
vanes" as the velocity falls leads to higher rise;
and
2. As the angle through which the fluid must
turn to exit decreases, the fluid exits more nearly
horizontally and thus does not rise as high.

A VARIATION
For graduate courses, one may insert a 5/16"
thin-wall tubing about 10" long, open at both
ends, into the pipe in place of the rod. In this
case the flow through the tube will be great
enough that the two end jets will both rise higher
than the ones in the middle. This presents an
analysis problem suitable for graduate students.

SOME PRACTICAL CONSIDERATIONS
1. The pipe connections should be finger tight. A
small leak doesn't hurt.
2. In placing the copper tubes in the holes in part
No. 3, little care is needed to align them. After they have
been soft-soldered in place, they can be easily bent into
line by holding the pipe in a vise, inserting a steel rod
in each tube, and tapping it gently into line with a
hammer.
3. To make the pipe without the tubes (part No. 2),
use extreme care to get the holes in one axial line.
4. While running the experiments, tilt the plane of
the orifices a few degrees to one side (by rotating the
pipe) so that the jets fall free of the pipe and do not
interfere with each other.
5. Check the apparatus carefully for burrs. They can
have a pronounced influence.
6. In running the first part of the experiment, it is
well to show that the result is independent of which end
of the pipe is inserted in the can. As long as all the con-
nections are finger tight, the instructor can reverse the
position of the pipe in the can quite quickly.
7. Allow adequate time to make up methocel solu-
tion. Sugar solutions could be substituted, but they are
messy. Any viscous solution will do, but methocel is prob-
ably the cheapest and easiest.

ACKNOWLEDGMENT
This device was used by Dr. J. Q. Cope, former vice
president of the Chevron Chemical Corporation, to teach
young engineers several important lessons. His procedure
was:
1. Describe the apparatus to the new engineer, with-
out mentioning the insertable rod.
2. Ask him from which end of the pipe the jet will
squirt highest.
3. When he answers, goad him into betting that he
is right.
4. Go get the device, inserting the rod if necessary.


5. Demonstrate-and take his money.
The educational qualities of this procedure are ob-
vious.

NOMENCLATURE


diameter
Fanning friction factor.
lost work per pound due to friction
acceleration of gravity
length
mass
pressure
velocity
pump work
elevation
absolute roughness
density


ft

ft-lbf/Ibm
ft/sec2
ft
Ibm
lbf/in2
ft/sec
ft-lbf
ft
ft
lbm/ft3


REFERENCES
1. Perry, J. H., et al. Chemical Engineers' Handbook
(4th Ed.; McGraw-Hill, 1963), p. 5-19 et sec.
2. Acrivos, A., B. D. Babcock, and R. L. Pigford,
'Flow Distributions in Manifolds," Chem. Eng.
Science. 10 (1959), pp. 112-124.


BOOK REVIEW: (Continued from p. 110)

Atom balances, purge and recycle are not dis-
cussed. Although reactors form a central theme;
conversion, yield and extent of reaction are not
used or defined. The enumeration of the number
of equations (mass balances, mass fraction con-
straints) does not appear, for this text does not
deal with multi-unit processes in multicomponent
systems.
The mathematical content is such that a stu-
dent should have finished calculus and differ-
ential equations. Parenthetically, the student is
asked to deal with a large amount of notation to
appreciate the content. Computer methods are not
stressed, although there is material on numerical
methods. Any computer applications would re-
quire a supplementary text. Linear algebra, which
some people refer to as "the language of stoich-
iometry," is not used.
In short, one must compliment the authors on
their attempt to inject vitality and meaning into
the first text in chemical engineering. However,
their approach does not fit well in a so-called
"standard" core curriculum. Perhaps our curricu-
la will adapt: I for one concur with their phi-
losophy. For the present, the book will find use
in peripheral ways, such as refresher courses.

ROBERT H. KADLEC
UNIVERSITY OF MICHIGAN


CHEMICAL ENGINEERING EDUCATION










THE CHE DESIGN LABORATORY


HARRY SILLA
Stevens Institute of Technology
Hoboken, N. J. 07030

A new design program for senior-undergradu-
ate chemical engineers was initiated at Stevens
Institute of Technology in the 1968-69 academic
year. One important feature of the program is
the use of the ChE laboratory as a vehicle for
teaching design. Because of the emphasis on de-
sign, this laboratory is called the ChE design
laboratory. This paper discusses the philosophy
and organization of the laboratory.

PHILOSOPHY AND OBJECTIVES
A recent report* gives the distribution of
chemical engineers according to areas of speciali-
zation. As one would expect, no one category pre-
dominates. For this reason it does not seem rea-
sonable to place the emphasis in design educa-
tion entirely on process design. In order to obtain
a broader and more flexible program in design we
have added the ChE design laboratory to our
course to complement process design. Besides
giving a student who is interested in process de-
sign a broader view, the design laboratory also
gives the student experience in project engineer-
ing and the design of experimental systems for
research and development. Furthermore, one of
the most valuable experiences any young engi-
neer can obtain is to follow a project from its con-
ception through it design stages and finally reduc-
tion to practice. The design laboratory gives the
student this opportunity.
The importance of design in research and de-
velopment needs further discussion. An engineer
working in this area must frequently design his
own apparatus, and he must usually show results
within a year to justify the continuation of a re-
search project. A considerable amount of valuable
research time may be wasted due to errors in the
design of apparatus. There are many unpredict-
able factors in a research project that one cannot
afford to be held back by errors in design. Prob-
ably, some of the recent disenchantment with re-

*Roethel, D. A. H., Counts, C. R., Realignments in the
Chemical Profession Continue, p. 90, Nov. 15, 1971.


search productivity can be traced back to avoid-
able delays caused by poor equipment design. At
any rate, the one way a research engineer can
increase his productivity is by becoming a skilled
designer of equipment. The importance of design
in research and development is generally over-
looked.
ANATOMY OF A PROJECT
Each student is interviewed and assigned a
project according to his interest and ability. The
process begins by having each student make up a
resume of his experience, skills and career ob-
jectives. After the interview the students are
formed into teams which consists of a maximum
of three students. Teams of two students are
optimum, but economics requires that many three-
man teams be formed.
We are willing to undertake many types of
projects. Our only requirements are that the
project is useful; that someone can be found who
is knowledgeable in the area to act as an advisor
for the project; and that the project can be com-
pleted at a reasonable cost. A project may involve
designing a completely new apparatus or design-
ing an improvement or addition to an existing
system. It should be emphasized that an important
objective of the design laboratory is that the stu-
dents develop the skills required to reduce his
design calculations to practice. It is one thing to
make design computations and another thing to
translate these computations into a working sys-
tem. A typical project involves a) definition of
the problem b) design calculations c) evaluation
and purchasing of equipment d) assembling the
apparatus e) testing and trouble shooting f) col-
lecting correlating data g) and writing the final
report.
The student is usually given the objectives
of his project in a general way. To help define the
problem students are required to search the litera-
ture and read several articles to become familiar
with the theory and experimental details.
Since the design laboratory involves many
different projects, much of the information must
be conveyed through personal contact. Thus, the
student is urged to seek information from faculty
members, graduate students and industry. There
are, however, many aspects of apparatus design


SUMMER 1973























Harry Silla obtained his BS degree from City Univer-
sity of New York and his MS and PhD ('70) degrees from
Stevens Institute of Technology. His research interests
include combustion and transport properties of flame
plasmas.
that appear frequently enough to warrant discus-
sing them in lectures; for example the design of
flow systems. In the design laboratory there is no
need to withhold information from the student,
that is, the instructor knows the answer to a par-
ticular problem but withholds the answer to see if
the student can arrive at the same answer. There
are enough real problems to be solved without
creating artificial ones.
After making their design calculations the
students are ready to select standard parts such
as heat exchangers, pumps, valves and instru-
ments to produce a working system. In some cases
special parts must be designed and fabricated.
This requires a knowledge of materials, equipment
and fabrication techniques. Since the students do
not have the necessary experience to fabricate
equipment, they discuss their designs with the
departmental machinist and graduate students
who are working on experimental theses. At this
point the reliability of their design is also con-
sidered. Will the apparatus withstand the temp-
eratures and pressures? Is thermal expansion
considered? Are corrosion-resistant materials se-
lected? Is the apparatus safe?
If the necessary equipment is not available
in the department's stockroom, students are given
equipment catalogs, and they are urged to contact
sales engineers to discuss their problems. This
aspect of the design forces the students to con-
sider not only equipment costs but also the im-
portance of time as a factor in construction of
equipment.
The students are held responsible for the ac-
curacy of their work. It is not possible to check


all the detailed calculations for the many projects
that are being carried out. The laboratory instruc-
tors and graduate-student advisors, however, be-
cause of their greater experience will be able to
tell if a number or design is reasonable and thus
will prevent the student from making any serious
errors. It goes without saying that when the
students construct and test their equipment their
oversights, errors in calculations and planning are
emphasized. When a student obtains 90% on an
examination, he walks away pleased, but in the
design laboratory this frequently is not enough.
To extricate himself from his miscalculations
forces him to be very inventive.

DESIGN PROJECTS
A total of twenty projects are currently under
way. These projects are listed in Table 1. Some
of these projects have been continued from the
previous year. For these latter projects, the stu-
dents begin by reading final reports of last year's
graduates, evaluating their recommendations, and
outlining a program. This feature of continuing
projects adds considerable flexibility to the course,
because all projects are eventually completed.
Many of our projects are directed toward ex-
panding our laboratory facilities. Examples of
this type of project is the design of a Karr sol-
vent extraction column and a batch reactor facil-
ity. These projects will improve our capabilities
to handle more complex problems in the future.
Other projects are to design equipment to col-
lect engineering or physical property data re-
quired for design: for example, measuring heat
transfer coefficients in falling film evaporator or
obtaining vapor-liquid equilibrium data. Admit-
tedly, designing apparatus for measuring physical
property data does not have much glamour, but
this can be just as challenging as designing a dis-
tillation column.
One of our more novel projects is the develop-
ment of a process to extract potential antibiotics
from sea sponges. The objective in this project is
to extract sufficient material for an organic
chemist to determine the structure of biologically
active compounds. These compounds will then be
synthesized by an organic chemist. A similar pro-
ject is to determine the sex attractant dispersed by
a female lobster. The interest in studying the lob-
ster is for aquaculture and commercial trapping.
The students in this group are designing a Karr*
*We are grateful to T. C. Lo of the Hoffman-LaRoche
Co. for his help in the design of the extractor.


CHEMICAL ENGINEERING EDUCATION









TABLE 1-DESIGN LABORATORY PROJECTS
Project and Faculty Advisors
Separations
Extraction of Antibiotics from Sponges, A. K. Bose, J.
Kryschuk, H. Silla
Extraction of Sex Attractant of Lobsters from Sea Water,
A. K. Bose, R. L. Spraggins,b H. Silla
Controlled Cycling Solvent Extraction, H. Silla
Countercurrent Distribution Solvent Extraction, H. Silla
Fluid Bed Drying, H. Silla
Filtration, H. Silla
Polymers
Design of a Stress Relaxometer, C. G. Gogos
Effects of Porosity on the Physical Properties of Poly-
mers, K. C. Valanis
Development of a Hydrophilic Gel for a Gel-Permeation
Chromatograph, J. A. Biesenberger, I. Duvdevani
Instrumentation
Design of a Gel-Permeation Chromatograph, J. A. Biesen-
berger, I. Duvdevani
Reaction Engineering
Internal Recirculation Catalytic Reactor, G. B. DeLancey,
H. Silla
Catalytic Plasma Jet Reactor, M. J. McIntosh
Fluid Bed Combustion for Waste Treatment, H. Silla
Biomedical Engineering
Diagnosis of Lung Damage by Measuring Weight Shifts
in the Upper Body, J. R. Kaime, H. Silla
Ultrasonic Generation of Monodispersed Submicron Par-
ticles for Lung Studies, M. Lippmann', H. Silla

Engineering Properties
Heat Transfer in a Fluid Bed, M. Sacksa, H. Silla
Flow in a Fluid Bed, M. Sacksa, H. Silla
Heat Transfer in a Falling Film Exaporator, H. Silla
Plate Efficiencies of a Sieve Plate Distillation Column,
H. Silla
Transport Phenomena in a Flame Plasma, H. Silla
a. Doctoral student
b. Post-Doctoral Research Associate
c. M.D., College of Medicine and Dentistry of New
Jersey at Newark
d. Ph.D., New York University Medical Center


extraction colum to remove the sex attractant
from sea water.
Each year there are a few students who are in-
terested in biomedical engineering or who intend
to go to medical school. To satisfy this group of
students we have established a working relation-
ship with a local hospital to generate medical
projects. Last year two students designed and
built an automatic blood sampler which is now
being used by the hospital.** There is a need for


Besides giving a student... in process design
a broader view, the design laboratory also gives
the student experience in project engineering
and the design of experimental systems
for research and development.


rapidly locating which lung is damaged because of
accidents or diseases. This is not as simple as it
may appear. The student involved in this project
is investigating the possibility of measuring the
shift in the center of gravity of the individual
during his breathing cycle. During inspiration
the heart shifts in the direction of the damaged
lung, thus causing a shift in the individual's cen-
ter of gravity.
The design of instrumentation is a rich source
of projects and an area where many principles of
chemical engineering can be applied on a minia-
ture scale. Gel-permeation chromatography is an
example of a project of this type. In this project
the students were assigned the problem of rede-
signing an existing chromatograph with the ob-
jective of making a more reliable compact instru-
ment.

CONCLUSIONS

The design laboratory has been enthusiastic-
ally accepted by the students, who have christened
the design laboratory, "The Super Lab." Even
students who have had no prior interest in design
or who have chosen other areas of specialization
have been challenged by the projects. The design
laboratory not only is a challenge to the student,
but to the instructor as well because of the variety
of projects that must be managed, and because
the projects are constantly changing.
The design laboratory is still in the process of
evolving, and many problems will have to be
solved before the laboratory reaches maturity,
nevertheless, the results to date have been grati-
fying. One can see a student arrive in the Fall in
"rough form" and then leave in the Spring as a
much improved engineer. We have reached the
point in the design laboratory where we feel that
many of the design projects are equivalent to
industrial experience. The design laboratory
should play an important role in the undergradu-
ate chemical engineering curriculum.


**We are grateful to Dr. W. Perl of the College of
Medicine and Dentistry of New Jersey at Newark for
his help in the design of the sampler.


SUMMER 1973










FLOW MODELING AND PARAMETER ESTIMATION

USING RADIOTRACERS


R. W. ROUSSEAU, R. P. GARDNER and
R. M. FIELDER
North Carolina State University
Raleigh, North Carolina 27607

A common method of formulating dynamic
models is to introduce a process upset (such as a
tracer injection) and to measure the subsequent
response. There are several important restrictions
on the use of this method: the upset must be
measurable without being dramatic enough to
cause system failure, the production of off-
specification product, or a threat to the safety of
people and/or equipment; in addition, the experi-
menter must have access to the process stream,
either through a control valve or tracer injection
site, and he must have the capability of monitor-
ing the process response. The latter requirement
can be fulfilled in many industrial systems only
if a radioactive isotope is used as a tracer.
In the experiment to be described, a radio-
tracer impulse is injected into a turbulent stream
flowing in a straight pipe, and the count rate at
two downstream points is measured as a function
of time. The results are used to determine dis-
persion model parameters (mean residence time
and effective axial dispersion coefficient) by the
method of moments. The estimated values of the
dispersion coefficient are then compared with
values predicted by a published dimensionless
correlation of Peclet number vs. Reynolds num-
ber.
The educational objectives of the experiment
are to expose the students to the concepts of
process modeling and experimental determination
of model parameters, to lay a basis for subsequent
presentation of material on process dynamics and
the design and scaleup of nonideal process vessels,
and to introduce the topics of tracer technology,
radiosotopes handling and radiation detection,
subjects not usually encountered in the under-
graduate chemical engineering curriculum.
The background material presented to the
class covers fully the problems associated with
radioactive materials, and discusses alternative
tracers such as dyes and electrolytes. It also


briefly reviews problems which have been success-
fully attacked using radioisotopes (many of which
are presented in the work by Gardner and Ely
(1967)), including the determination of flow
rates and flow channel volumes in process units,
blood vessels and rivers and streams, formulation
of models for industrial processes and biological
systems, measurements of diffusion coefficients
and kinetic rate constants, measurements of mix-
ing efficiencies in stirred tanks, determination of
the existence of channelling or bypassing and
stagnant regions in process units, and measure-
ments of currents and dispersion patterns in re-
ceiving waters. We believe that this list, as exten-
sive as it is, represents only a fraction of the
potential applications of radioisotopes to the solu-
tion of problems with which chemical engineers
are likely to be confronted, and that having once
been introduced to radioisotopes in their educa-
tion, engineers will be more likely to think of
them when dealing with such problems.

EXPERIMENTAL
A schematic of the experimental system is shown in
Figure 1. Water is fed to the system from a constant
head tank through a rotameter into a long % inch NPD
galvanized pipe, and from the pipe into a storage tank.


*Detectors


Rotameters


Sewer


Fig. 1. Schematic of Experiment.


Tracer is injected into the pipe through a regular pipe tee
fitted with a rubber septum. Detectors are mounted at
either end of a 20 foot straight section of the pipe down-
stream of the tracer injection point. The storage tank
is used to allow the radioactivity to decay to a negligible
level before the effluent is sewered.


CHEMICAL ENGINEERING EDUCATION




























Ronald W. Rousseau received his BS, MS, and PhD from
Louisiana State University. He has industrial experience
with the Ethyl Corporation and Westvaco, Inc. He has
been at North Carolina State University since 1969; re-
search interests include crystallization, vapor-liquid
equilibria, process modeling and applied polymer chem-
istry. He teaches mass and energy balance calculations,
transport processes and mass transfer operations.
Robin P. Gardner received his BChE and MS from North
Carolina State University and his PhD from Pennsylvania
State University. From 1961-63 he was Scientist in Charge
of Short Courses on Radioisotope Applications in Indus-
try at the Oak Ridge Institute of Nuclear Studies and
later was Assistant Director of the Measurement and
Controls Lab at the Research Triangle Institute. He was
an IAEA Expert at the Institute of Radioactive Research
in Belo Horizonte, Brazil and currently is Professor of
Nuclear and Chemical Engineering at NCSU. (center)
Richard M. Felder did his undergraduate work at the
City College of New York and obtained his PhD from
Princeton. He spent a year at AERE Harwell, England
on a NATO Postdoctoral Fellowship, two years at Brook-
haven National Laboratory, and came to NCSU in 1969.
Recently he has become involved with photochemical re-
actor analysis, radioisotope applications, and applica-
tions of engineering technology to medical and environ-
mental problems. He has served as a consultant to the
government of Brazil on industrial application of radio-
isotopes. (right)

Manganese-56, in the form of an aqueous Mn(NO3)2,
solution, was selected as the tracer because it is a gamma
ray emitter and hence can be detected through metal
walls, and because it has a half-life of only 2.6 hours,
which causes it to decay to negligible levels in less than
24 hours. Geiger-Mueller tubes were the detectors; their
outputs were fed to a Nuclear Chicago rate meter coupled
to a Leeds and Northrup strip chart recorder.
Both single and two-point detection methods were
demonstrated in the experiments, using detectors placed
at distances of 6 and 26 feet from the point of injection.
While it is desirable that the detectors have approxi-
mately the same sensitivity, deviations from this condi-
tion are not serious because of the method of data


analysis. Typical output from a run using both detectors
is shown in Figure 2, which plots the counting rates re-
corded by the first and second detector vs. the time from
injection.




70 -



60 -



-50 -
0


S40 -



S3 -
F-


20 -



10 -



35 30 25 20 15 10 5 0

TIME , sec

Fig. 2. Typical Analog Output.

COMPUTATIONAL PROCEDURES

Flow systems in which a measurable but finite
amount of axial mixing occurs are commonly
simulated by two-parameter models, such as axial
dispersion and tanks-in-series models. The para-
meters of these models are simply related to mo-
ments of the system impulse response function,


SUMMER 1973










and may be conveniently estimated from numeri-
cally calculated moments of experimental re-
sponse curves. In contrast, parameter estimation
techniques such as time-domain and frequency-
domain regression require considerable computa-
tional effort, and are consequently less suitable
for inclusion in a junior-level laboratory course.
The quantities needed to estimate the para-
meters of a two-parameter flow model by the
method of moments are


St Ri(t)dt

Ri (t)dt
2o


i = 1,2


(1)


2 (t-pi) 2Ri(t)dt
o. 1 = 1,2 (2)
S Ri(t)dt
where Ri(t) is Lhe counting rate at the ith detec-
tion station, and ui and -i2 are respectively the
mean and variance of this function. The pro-
cedure is to choose a model, derive expressions
for the model parameters in terms of ui and
a-i2, evaluate the latter quantities from the experi-
mental impulse responses and Eqs. (1) and(2)
by numerical quadrature, and use the resulting
values to solve for the model parameters. In the
experiments run so far, hand calculations of the
moments from analog output were required; in
the future, the output from the rate meter will
be punched on paper tape, which will in turn be
used as input to a Simpson's Rule quadrature
subroutine.
The model chosen for illustrative purposes
was the doubly-infinite axial dispersion model.
The assumptions inherent in this model and so-
lutions for the impulse response and its moments
are outlined by Himmelblau and Bischoff (1968)
and Levenspiel (1972). The relations used in the
single-detector measurements are as follows:


- L
S1 = i


i = 1,2


(3)


2
- 2-+ and Pi = vLi/D (4,5)
i1 Pi
where Li is the distance from the injection point
to the ith detector, v is the mean flow velocity in
the tube, and D is the effective axial dispersion
coefficient. The procedure followed was to calcu-
late ul and o-2 from the experimental Ri data us-
ing Eqs. (1) and (2), then to evaluate the ve-
locity v from Eq. (3), the Peclet number P1 from
Eq. (4), and finally D from Eq. (5). The two-
detector method provides two advantages over


the single detector method: the injection does not
have to be a perfect impulse, and errors in syn-
chronizing the time of injection with the record-
er output are eliminated. The equations for the
two detector method are
L2-L1
21 - (6)

2 2
2 -1 2 (7)


v(L2-L1) (8)
D
In this case the velocity v is calculated from the
numerical moments using Eq. (6), the Peclet
number P is calculated from Eq. (7), and D is
calculated from Eq.(8).
Table 1 shows values of flow velocities deter-
mined with a rotameter and calculated as out-
lined above. It is interesting to compare the re-

Table 1-Flow Velocities


Run u(from rotameter) u,


2.01ft/sec
1.53
1.0
1.0


1.77
1.07
0.938


u, u,,
1.88 1.91
1.37 1.4l
0.945 0.9�
1.03 -


sults obtained by the one- and two-point tech-
niques: the average error is 16% for the single
detector at 6 feet, 6% for the single detector at
26 feet, and 2% for the two detectors. Figure 3
in a plot of the effective axial dispersion coeffi-
cient vs. the Reynolds number, and shows that
the data fall within the range predicted by a


L�
N



L_
u
o
C

(C
Z
o


r-
*�


Si
0
Li
a
0i


M ----_I 111111 - I I 11111 t'-
80 -
70-
60 -
50 -
>40 -
,30 -

20


10-
9-
al
6-
5 -
4-
3
2 Accepted Experimental Range


) I I IIII I 11 11 I I 1111 l


I 2 3 4 5 6 78910 20 30 40 50bU6fUU90
REYNOLDS NUMBER x IF3
Fig. 3. Dispersion Coefficient as a Function of Reynolds Number.


CHEMICAL ENGINEERING EDUCATION


.^


method of moments are









The educational objectives of the
experiment are to expose the student
to the concepts of process modeling
and experimental determination of
model parameters ...


correlation reprinted by Himmelblau and Bischoff
(1968). Since doing so would not serve any par-
ticular purpose in light of the educational objec-
tives of the experiment, we have not attempted
to confirm the negligibility of adsorption other
than to note the absence of long tails on the im-
pulse response curves.

DISCUSSION
The students are given two 3-hour laboratory
periods to complete the experiment. In the first
period they go through the entire experiment
without actually using the radiotracer. Under this
format they each get a chance to become familiar
with the equipment and injection procedure with-
out the worry of spills or other hazards. Also
during the first 3-hour session they are instructed
in fundamentals of radiation detection, particu-
larly as related to Geiger-Mueller characteristics,
and in radiation safety. In the second 3-hour
period the actual runs are made, but the injec-
tions and tracer handling are not done by the
students, who merely observe. The runs them-
selves are not particularly time-consuming, so
that each student has sufficient time to carry out
the necessary calculations and to seek individual
instruction on any aspect of the experiment.
The participating students appeared to get a
great deal out of the experiment; the only strong
objection was to the necessity of calculating mo-
ments graphically from analog output, a require-
ment which will be eliminated in the future when
digital output equipment becomes available. A
potential problem with an experiment of this sort
being given on a junior level is that the students
may have to accept on faith the utility of much
of what they are doing. This did not appear to
be a matter of concern to the students, however,
possibly due in part to the fact that they had
been introduced to elementary concepts of model-
ing (and in particular to the dynamic response
of a first-order process) in a previous course. The
experiment also served to make related material
subsequently encountered in senior courses on
reactor design and process dynamics and control
a great deal more meaningful to those who par-
ticipated in it.


Once the basic procedure for a stimulus-
response experiment of this type has been estab-
lished, it is a relatively easy matter to study a
variety of flow systems using the same technique.
We are currently making provisions for the fol-
lowing experiments:
1. Flow and dispersion in packed columns.
2. Flow in obstructed tubes
3. Detection of stagnancy and channeling
4. Residence time distribution of stirred tanks in series
5. Variation of RTD with stirring rate in a single stirred
tank-determination of mixing efficiency.
6. Impulse responses of laminar flow systems.
Our present plan is to include one of these ex-
periments (probably the one on the packed col-
umn) in the laboratory course, either in addition
to or instead of the empty tube experiment, and
to use the others as senior projects.D

REFERENCES
Gardner, R. P. and R. L. Ely, Jr., "Radioisotope Measure-
ment and Applications in Engineering," Reinhold Pub-
lishing Co., 1967.
Himmelblau, D. M. and K. B. Bischoff, "Process Analysis
and Simulation," Chapter 4, John Wiley and Sons, Inc.,
1968.
Levenspiel, 0., "Chemical Reaction Engineering," Chapter
9, John Wiley and Sons, Inc., 1972.


LAB WORKSHOP (Continued from p. 125)

D. J. Graves discussed the use of audio-visual
packages in the preparation phase of the labora-
tory experiment. The student prepared modules
used to describe complex pieces of equipment,
measurements points, flow paths, and complex
procedures. At the University of Pennsylvania
the audio-visual modules have reduced laboratory
time and allowed students to continue to work on
project experiments after previous groups have
graduated. Two sample audio-visual modules were
shown to illustrate their use with typical experi-
ments.
The entire proceedings of the laboratory work-
shop are to be published and can be obtained by
sending a check for $10.00 payable to The Uni-
versity of Michigan to Professor H. Scott Fogler,
Department of Chemical Engineering, The Uni-
versity of Michigan, Ann Arbor, Michigan 48104.
The price of the bound proceedings, which will be
available after May 1, 1973, was established by
the ASEE ChE Division in order to minimize any
loss of funds from printing costs.


SUMMER 1973










A COMPUTERIZED UNDERGRADUATE PROCESS

DYNAMICS AND CONTROL LABORATORY

R. A. SCHMITZ
University of Illinois
Urbana, IL 61801


A project to computerize the undergraduate
process dynamics and control laboratory in the
Department of Chemical Engineering at the Uni-
versity of Illinois was begun in 1969. The plan
was to use an existing IBM 1800 computer, which
was operating on a time-sharing basis in the
School of Chemical Sciences, to provide a facility
for computer-aided instruction and for computer-
aided experiments by undergraduate students.
Our motivation for the project was the realization
that a facility of this type would permit more ex-
tensive and more meaningful laboratory studies
of process dynamics, simulation and control than
are possible in conventionally-equipped labora-
tories. We also felt that the hands-on use of an
on-line data acquisition and control system would
be a valuable experience for the students and that
the lecture portion of certain courses would be
greatly improved by the demonstrations and vis-
ual displays made possible by an on-line com-
puter. Similar projects have been undertaken at
a few other chemical engineering departments at
universities in the United States and Canada1'7.
A recent report of the CACHE (Computer Aids
in Chemical Engineering Education) Committees
presents a brief description of these activities.
Certainly at this point in time, the use of a
computerized undergraduate laboratory in ChE
education is a relatively new development. Since
the few facilities that are in existence were estab-
lished quite dependently, each incorporates some
unique features, and publications of their descrip-
tions should be informative and valuable to other
departments which may embark on similar proj-
ects. Many such departments will probably find
themselves in a situation similar to ours at Illinois
at the outset of this project; that is, with an
accessible time-sharing computer of the large or
medium-sized variety and an existing laboratory
equipped with conventional instruments and con-
trollers. While the task of interfacing the labora-
tory and the computer and of developing a soft-
ware system in such cases may be demanding in


Roger A. Schmitz received his BS degree from the
University of Illinois and his PhD from the University
of Minnesota. He joined the ChE faculty at the University
of Illnnois in 1962. His area of specialization is the stabil-
ity and control of chemically reacting systems. He was
awarded a Guggenheim Fellowship in 1968-69 and was the
recipient of the Allan P. Colburn award of the AIChE in
1970.

terms of labor, the investment of dollars in hard-
ware should be minimal. Departments not so for-
tunately situated with regard to an existing com-
puting facility will probably go the route of in-
vesting in a minicomputer.

THE SYSTEM AND ITS OPERATION
The IBM 1800 computer in the School of Chemical
Sciences has 32,000 words of core memory and uses three
disks (500,000 words each) for auxiliary storage. It is
equipped with the usual peripherals including (1) an
analog-to-digital (A/D) converter capable of receiving
signals on a -5 to +5 volt range, (2) a digital-to-analog
(D/A) converter capable of sending voltages on the
range 0 to +5 volts, and (3) a card reader. A description
of the computer system, the monitoring program and
IBM's Time-Sharing Executive (TSX) System has been
published.9
Three thirty-conductor cables connect the computer to
the process control laboratory. These cables actually
branch to nine stations connected in parallel. Four of
these are chemical engineering research laboratories,
another is a terminal in a room housing an EAI 580
analog computer, and the remaining four are in the
process control laboratory. One cable is devoted entirely
to an IBM 1053 output printer which can be connected
at any of the stations.
A user at any station in the process control labora-
tory has access to A/D and D/A channels, a process in-
terrupt switch, digital inputs (two-position switches) and


CHEMICAL ENGINEERING EDUCATION
















PROCESS

( i1( level


Transducers -5 to +5v
Amplifiers - t
Drivers

IBM 1053 Printer


Disk-Stored Programs


(2) heat exch Transducers - to+5v
(3) pH inCSTR to 5 psiIII- 5v
tog. 1. Schematpsic Diagram of Closed-Loop Systems




Fig. 1. Schematic Diagram of Closed-Loop Systems


digital outputs (lights). Altogether there are eight A/D
and four D/A channels, nine lights, and nine switches.
The switches and lights allow for user inputs to the
stored programs and for user options.
To gain access to the disk-stored programs for the
process control laboratory, the user at any station must
activate the process interrupt switch. This causes the
transfer into core and the execution of an initializing
program which governs the building of the core load
for the process control laboratory. The core load consists
of a supervisory program along with associated sub-
programs and the subroutines used-all initially stored
in disk memory. When core-load building is complete,
execution of the supervisory program begins. It first in-
structs the computer to flash two lights at all stations
in the laboratory repeatedly, waiting for the user to
select, by means of switch settings, a desired subprogram.
As it is presently written, the supervisory program can
accommodate twenty-seven different subprograms each
having a different three-digit code number. To call a
desired subprogram, the user enters the three integers in
the appropriate code number successively in binary form
using the two switches at his experiment station. After
a three-digit code is entered, the supervisory program
branches to the subprogram stored under that code. Upon
completion of the subprogram, control is returned to the
supervisor, lights are again flashed at all stations wait-
ing for another subprogram to be called.
In the usual operation of the laboratory, the initializa-
tion procedures are handled by the instructor or the
laboratory assistant. The student then encounters the sys-
tem and takes over its operation with the supervisory
program being executed; that is, with lights flashing in
wait of a subprogram code to be entered. The students
are responsible for the writing, disk-storing, and de-
bugging of the subprograms. They ordinarily work in
three-man groups, and each group is assigned a sub-
program code number for the course. The subject of
programming will be taken up in more detail in a later
section of this peper.
Only one subprogram can be executed at a time as
the system presently stands. This means that no two
experiments in the control laboratory, both using the
computer, can be carried out simultaneously. We can
make programming modifications to remove this limita-
tion if it becomes necessary to do so.


As mentioned earlier, the computer operates on a
time-sharing basis. For background jobs, that is those
not involving real-time applications, each user's core load
resides in the core and is executed for a short time
before being "swapped" to disk-storage for a period of
time. Our system monitor program presently allots a time
slice of twenty seconds for core residence time. Much of
the computer usage in the process control laboratory
falls into this background category. Those programs,
however, which make use of the real-time clock; that is,
those which call for frequent interrupts for reading and/or
sending analog signals at specified intervals of times, have
priority status and are not swapped from the core. The
computer services these frequent interrupts as a fore-
ground task, returning to background jobs in the interim
periods.

THE LABORATORY
The equipment at each of three of the four
stations in the process control laboratory com-
prises a simple control loop with a single meas-
ured variable and one manipulated variable. One
of these involves the control of the liquid level in
a cylindrical column packed with Plexiglass
spheres; another, the control of temperature of
the effluent water from a tube-and-shell heat ex-
changer; and the third, the control of pH in a
stirred vessel. Each of the three setups, which are
represented schematically in Figure 1, involves
standard measuring and signal transducing de-
vices so as to produce dc voltage signals for the
measured variables on the range -5 to +5 volts
for input to the A/D converter on the computer.
The measurement originates from a process pres-
sure (hydrostatic head) -to-current transducer in
the liquid level system, from a thermocouple in
the heat exchanger and from a submerged pH
electrode assembly in the stirred vessel. The D/A
signal from the computer is converted to a cur-
rent and then to an air pressure signal in the


Fig. 2. Photogaph of Liquid Level Control System.


SUMMER 1973


)/A









range 3 to 15 psi. The pneumatic signal is sent to
a diaphragm control valve, the final control ele-
ment in all three cases. The manipulated variables
are (1) the flow rate of water to the packed
column of the liquid level system, (2) the steam
pressure on the tube side of the heat exchanger
and (3) the flow rate of a hydrochloric acid solu-
tion to the stirred vessel.
The photograph in Figure 2 shows the physi-
cal layout of the liquid level system; the others
are similar. As shown in the photograph, each
station is equipped with a control panel on which
the process signal flow is printed. A close-up view
of the control panel for the liquid level process is
shown in Figure 3. The panel conceals most of the


Fig. 3. Operator's Control Panel for Liquid Level Experiment.
wiring connections and interfacing equipment.
As can be seen in the photograph of Figure 3, the
panel contains a process interrupt switch, two
lights (digital outputs) and two switches (digital
inputs). As is also shown in the photographs,
each of the three systems is equipped with a con-
ventional three-mode analog controller which can
be switched into or out of the loop as desired.
The equipment and the wiring connections for
these systems are intended to be permanent. In
working with these processes, therefore, the stu-
dent in the laboratory does not assemble appara-
tus or make any interface connections.
Typical experiments with the three systems
may involve the formulation and testing of
mathematical models via step response, frequency
response and analog simulation methods, and in-
vestigations of the closed-loop behavior both with
direct digital control and with conventional con-
trol. In all experiments the subprograms called
by the experimenter may contain instructions to
read and store data, send feedback signals, dis-


play experimental results on an oscilloscope,
carry out calculations and print results or data
on the output printer. Further description of the
programming effort required will be given in the
next section.
A fourth apparatus, which makes use of the
computer facility, consists of two different types
of pneumatic control valves and associated signal
converting and conditioning hardware. Experi-
ments with this setup, depicted schematically in
Figure 4, can be carried out using the control
panel at the pH control apparatus. As shown on
the left portion of Figure 4, voltage signals from
the computer may be sent to the valves, separ-
ately or simultaneously, and voltage signals, orig-
inating from displacement transducers attached
to the valve stems, may be sent to the A/D con-
verter on the computer. In the simplest experi-
ments with this system, the objective would be to
study and compare the frequency response of the
two valves. In such instances the subprogram
called by the student would instruct the computer
to send a sinusoidal signal of a specified ampli-
tude and frequency to the valves and to read a
voltage signal which indicates the instantaneous
valve positions. If he so desires, the student may
easily have his subprogram analyze the data and
print information to be used in constructing a
Bode diagram. He may also have results dis-
played on an oscilloscope.
With an analog computer inserted in the sys-
tem, as shown in Figure 4, real-time simulations
involving the simulation of some process on the
analog computer and incorporating real valve
dynamics are feasible. In experiments of this
type, the student may study the effects of non-
ideal valve dynamics in various control loops by
experimenting with simulated feedback systems


Fig. 4. System for Valve Dynamics Experiments and Real-Time
Simulations.

CHEMICAL ENGINEERING EDUCATION










containing ideally simulated valves in one instance
and the real valves in another. It will also be
possible in advanced studies to interconnect the
analog computer, digital computer and any or all
of the laboratory stations to form a complex
multivariable system containing some simulated
components and some real ones. A TR-10 analog
computer is available in the laboratory for some
small scale experiments, and an EAI 580 is
housed at a separate station for more extensive
simulations. For either computer, the linkage
from the patch panel on the analog machine to
the cables from the IBM 1800 is made through
a portable interface panel. The panel provides
access to all D/A and A/D channels to the IBM
1800 and to all nine lights and switches. The
photograph in Figure 5 shows an interconnected
system comprising the TR-10 analog computer,
the IBM 1800, the interface panel and a pneuma-
tic control valve. This system was set up to
demonstrate a real-time simulation of a chemical
reactor under direct digital control.
The fourth station in the process control
laboratory consists simply of a laboratory bench
at which the portable interface panel can be con-
nected to the cables from the computer. The pur-
pose of this station is to provide a versatile gen-
eral-purpose facility at which a variety of bench-
top experiments or demonstrations can be set up
and carried out in a short time, some perhaps on
a one-shot basis. Usually these experiments will
involve studies of the dynamics of individual
components or devices. A simple example is a
study of the dynamics of thermocouples with


Fig. 5. Photograph Showing a System Consisting of a Pneumatic
Control Valve, a Portable Interface Panel to the IBM 1800 Computer
and a TR-10 Analog Computer being used in a Real-Time Simulation
by an Undergraduate Student.


TABLE I. SUBROUTINE DESCRIPTIONS

Subroutine Function
ANDIG Read and print the instantaneous voltage on A/D channels)
specified in arguments in the calling statement.
ANLOG Periodically read A/D channels, send voltages on D/A
channelss, (see options below) and store data.
The sampling period and channel numbers are specified
in arguments in the calling statement.
Options:
(a) data logging, no D/A signals
(b) data logging with proportional D/A signal
for feedback control
(c) data logging with function generation (D/A
voltage) for analog simulations
(d) combination of (b) and (c).
DIGAN Send and hold a voltage on D/A channelss. The
magnitude of the voltage(s) d te chan nel numbers)
are specified arguments.
DISPY Send voltage data stored in INSKEL common arrays
(e.g. stored during real-time operations) for oscilloscope
display (i.e. cycle through the arrays). The arrsa to
be displayed and the variables for the x and y axis are
specified arguments.
FLASH Flash lights and wait for switches (digital inputs) or
process interrupt to be set before proceeding. Light
numbers) and flashing frequency are specified arguments.
PEROD Send sinusoidal voltage on a D/A channel ant log data
from A/D channelss. The frequency and period of the
sine function and the channel numbers are specified
parameters. An option in the subroutine permits the
user to specify some other periodic function (tabulated)
in place of the sine function.
PRIT Print voltage data stored in INSKEL common arrays
(e.g. stored during real-time operations). The arrays
to be tabulated are specified in arguments in the calling
statement.


various types of shielding, the computer being
used to read, store, print and display the thermo-
couple signals versus time.
As previously indicated, an oscilloscope with
an attached Polaroid camera, is available in the
laboratory. Thus, by employing a display subrou-
tine, as described in the following section, a stu-
dent can immediately observe his experimental
data and obtain a photograph for insertion in his
laboratory report.

PROGRAMMING
In order to keep student programming re-
quirements and de-bugging difficulties at a man-
ageable level, we have written a number of basic
programs for the process control laboratory and
have stored them permanently on one of the disks.
In addition to the initializing and supervisory
programs which are transferred into core
memory during initialization procedures, these
include a number of subroutines whose functions
include reading voltages, sending feedback sig-
nals, storing, displaying and printing data and
governing lights and switches. A list of these
routines along with a very brief description of
each is given in Table I. A complete description
of these routines is not essential here, but per-
haps a few comments, in addition to those given
in Table I, on some of them are called for. Each
subroutine is accessible through a standard Fort-
ran call statement that includes a list of argu-


SUMMER 1973








ments. Three of the routines, namely ANLOG,
DISPY and PEROD, handle real-time operations.
Those routines subsequently branch to various
entry points in an assembly language program,
also written by us specifically for the process con-
trol laboratory, which resides permanently in the
core memory initialization. Thus by means of
Fortran calls to these three subroutines, the user
has access to a variety of real-time operations.
The initiation and termination of the real-time
operations of data logging and sending by the
computer in ANLOG and PEROD are handled by
the student at the experiment site by means of
switch settings. For example, when subroutine
ANLOG is entered, a light is flashed (the light
number is specified in the list of arguments).
Periodic voltage readings and sending begin
when the corresponding switch is turned on. The
reading and sending end and the execution of the
next statement in the student's subprogram takes
place when that switch is turned off. In the
meanwhile, the user can call for the storing of
data over intervals of time during which a second
switch (the number of which is also specified in
the argument list) is turned on. The usage of
subroutine PEROD is very similar.
It should be noted that the subroutines in
their present form do not permit the changing of
parameters during the course of real-time opera-
tions. Thus the values of the proportional band,
sampling interval, etc., are specified prior to the
call or in the calling statement of ANLOG and
cannot be changed during the execution of that
subroutine In order to study various values of
these parameters, the student would either have
to call his subprogram repeatedly or have in-
serted his call statement within a loop for repeti-
tive calls.
As mentioned earlier, the student is required
to write the Fortran subprogram to which the
supervisory program branches when a certain
combination of switch settings is entered. Be-
cause of the available subroutines, this pro-
gramming requirement is simple. For example,
the following sequence of statements constitutes
the set of necessary instructions for executing
direct digital control with data logging, followed
by an oscilloscope display and printing of stored
data:
CALL ANLOG (parameters)
CALL DISPY (parameters)
CALL PRINT (parameters).


A study of frequency response would require
the substitution of "CALL PEROD (para-
meters)" in place of the call to ANLOG. Of
course, the student may make his program quite
involved to the extent of providing various ex-
perimental options and of carrying out calcula-
tions with the experimental data if he so desires.
Though the minimal programming require-
ment is quite simple, nearly trivial for some ex-
ercises, we feel that it is an important part of the
student's usage of the system. It gives him a
greater overall appreciation and understanding
of his experimental goals, of our particular sys-
tem and of software aspects associated with on-
line computing in general. Having to write a com-
puter program for his experiment in advance of
the laboratory session forces the student to study
the experiment carefully and to plan his labora-
tory procedure step-by-step. This in itself is a
noteworthy benefit of a computerized laboratory
in which the students are required to program the
experiments.
In the operation of the laboratory, the labora-
tory assistant or instructor assists the students
in disk-storing and de-bugging their subprograms
on the afternoon preceding the scheduled labora-
tory session. Some additional de-bugging is often
required during laboratory meetings. As men-
tioned earlier, the students work in three-man
teams, and therefore programming is a group
effort. Our curriculum contains a required course
in digital computer programming in the fresh-
man or sophomore year. In addition, the students
will have used Fortran programming in carrying
out assignments in a few courses prior to their
enrollment in the process control course.
In our initial or "trial" usage of the sys-
tem (Fall semester, 1972) the students carried
out three computer-aided experiments. We were
able to give adequate programming instruction
in two 90-minute workshop sessions early in
the semester. The sessions included a general
discussion of on-line computing and computing
control in addition to specific instructions and
:exercises on the usage of our system. Each
student was given a laboratory manual which
described the computerized laboratory and con-
tained instructions on the usage of disk-stored
subroutines and on the preparation of the
required subprograms. It also contained sev-
eral example subprograms. The workshop ses-
sions were followed by laboratory demonstra-
tions. We found that the preparatory instruc-


CHEMICAL ENGINEERING EDUCATION









tions so given were quite adequate. The students
were able to proceed from that stage at the level
of independence which we had sought. With some
minor revisions in the manual and subroutine
functions, we plan to introduce several additional
computer-aided experiments for the Fall term,
1973.
CONCLUSION
In this paper we have described briefly our
system for computer-aided experiments in an
undergraduate process dynamics and control lab-
oratory at the University of Illinois. We have
included some description of its usage, but will
elaborate further on the course description and
on the specific laboratory experiments and dem-
onstrations in future publications.
In designing the apparatus and the computer
programs for the system, we placed much value
on retaining basic simplicity so that students, in
an introductory course, would be able to under-
stand the operations of an on-line computing
facility and be able to use it to advantage on a
hands-on basis. We also strived for versatility
so that new experiments could be incorporated
easily and that utilization of the system could be
extended to more advanced topics, to very com-
plex networks and even perhaps to courses on
other subjects, such as applied kinetics.
We also felt that it was important to leave
the programming of experiments to the student,
but we have made available a number of subrou-
tines which make this task relatively simple.
There is a strong temptation for instructors in
such laboratories to program the experiments
completely and reduce the role of the student to
that of executing the programs. While such ex-
periments may be elegantly programmed and
virtually fail-safe, they may also stifle most of
the student's thought input. With the student in-
volvement in programming, even at a very simple
level, a greater appreciation of process-computer
interfacing is imparted, a greater degree of open-
endedness is automatically provided and presum-
ably more thought input, creativity, originality
and interest on the part of the student will be
realized.
Our facility was employed for the first time
in an introductory undergraduate course on pro-
cess dynamics and control in the Fall semester,
1972. Three computer-aided experiments con-
ducted by the students and two demonstrations
carried out by the author of this paper, were


used, and the consensus of opinions of students,
assistants and instructor was that the endeavor
was highly successful. The student interest and
enthusiasm for the laboratory were noticeably
greater than they had been in previous years
when similar experiments were conducted with-
out the aid of the computer. We plan to introduce
several additional experiments and demonstra-
tions for the next offering of the course (Fall,
1973). It will be possible to discuss more defini-
tive results and to present realistic evaluations
after a few more semesters of experience. Hope-
fully, the system we have developed as well as our
experiences in implementation will be helpful to
others embarking on similar projects.

ACKNOWLEDGEMENTS
This project received most of its financial support
through a grant from the National Science Foundation.
Departmental help was provided mainly in the form of
graduate teaching assistants and laboratory instructors.
Most of the electronic interfacing hardware was designed
and built in the electronics shop in the School of Chemi-
cal Sciences. The staff of the School's computer lab pro-
vided help with much of the basic programming. The
author would like to acknowledge particularly the val-
uable assistance of Mrs. Pat Anderson with programming
and the work of Dr. Ming Fang who designed and in-
stalled much of the hardware and apparatus.

BIBLIOGRAPHY
1. Christensen, J. H. and P. M. Vargo, "Education in
Real-Time Computing", Chem Engr. Ed. 5, 30
(1971).
2. Fisher, D. G., "Real-Time Computing in the Uni-
versity", Chem. Engr. Ed., 5, 24 (1971).
3. Westerberg, A. W. and R. C. Eschenbacher, "A
Real-Time Computer Control Facility", Chem. Engr.
Ed., 5, 32 (1971).
4. Wright, J. D., "Education in Computer Control: How
to Make Your Real-Time Clock Tick', Pulp and
Paper Magazine of Canada, 72, 4, 29 (1971).
5. Idier, M. and D. A. Mellichamp, "Computer Moni-
toring and Control of a Process Dynamics Labora-
tory', Paper No. 4b, 71st National Meeting of
AIChE, Dallas, Feb., 1972.
6. Wissler, E. H., "Computer Aided Methods for
Chemical Engineering Laboratories", Paper No. 4a,
71st National Meeting of AIChE, Dallas, Feb., 1972.
7. Moore, C. F., "A General Purpose Data Acquisition
and Control Utility," 7th Annual Conf. on Use
Digital Computers in Process Control, Louisiana
State University, Feb., 1972.
8. Elzy, E., L. B. Evans, R. C. Weaver and A. W.
Westerberg, "Real-Time Digital Computer Systems
in Undergraduate Education, Paper No. 47c, 72nd
National Meeting of AIChE, St. Louis, May, 1972.
9. Secrest, Don, "Time-Sharing Experimental Control
on a Small Computer", I&EC 60, 6, 74, 1968.


SUMMER 1973










international


A NEW TRADITIONAL UNIT OPERATIONS

LABORATORY COURSE


AAGE FREDENSLUND
Instituttet for Kemiteknik
Danmarks Tekiniske Hojskole
2800 Lyngby, Denmark


In 1968 the Department of Chemical Tech-
nology, the Technical University of Denmark,
moved from an old location in central Copenhagen
to a modern, spacious campus north of town.
The department was given adequate funds to de-
velop new laboratory courses, and a new, tradi-
tional unit operations laboratory course is now
completed. It is the purpose of this communica-
tion to describe the course in some detail so that
other chemical engineering departments may
benefit from this experience. The author will
gladly furnish further information regarding de-
tails of the course upon request. Before proceed-
ing further, it is necessary to explain the purpose
of the course.

PURPOSE OF THE COURSE
It is characteristic for the Danish chemical
industry that it consists of many rather small
units. One can therefore not depend on the indus-
try to give chemical engineering graduates a
professional, rounded technical training program.
This, and the fact that the ChE students are sub-
jected to a thorough physics laboratory course
early in the curriculum, indicate that in design-
ing the unit operations laboratory course, one
should emphasize real process equipment rather
than physical phenomena. That is to say that the
course should be based on equipment resembling
process equipment rather than transport phe-
nomena experiments.1
In the foreword of the laboratory manual2
for the course the purpose is stated as follows:

*To give an understanding of and a physical feeling
for the processes and transport phenomena taking
place in large scale chemical processing equipment.


*To show how the principles developed during the
lectures in unit operations may be used in designing
and running processing equipment.
*To furnish insight into how the unit operations used
in the chemical industry work and the limitations of
these.

These purposes have had a large influence on
the design of the equipment for the experiments.
One might say that the course constitutes a
"movement" away from transport phenomena
laboratory type equipment. This does not mean,
however, that transport phenomena type measure-
ments (for example, single film heat transfer
coefficients as opposed to overall coefficients) are
not carried out in the course. Indeed they are,
but the tendency is to perform the measurements
in process equipment so that the students do not
have to extrapolate from model experiments to
real life. It is understood that a similar "move-
ment" is taking place in several ChE departments
in the US.

COURSE CHARACTERISTICS
The course is offered twice a year in three-
week periods during which the students devote
their full attention to the course. The maximum
number of students is 70 per three-week period.
Since this is an introductory course, it was found
best to expose the students to as many different
unit operations as possible. For pedagogic
reasons it was decided to work with small teams
of students (two per team). For these reasons, a
relatively large number of experimental units
was found necessary. It was also found necessary
for the students to work with ready-made experi-
mental units. If the students were to construct
the equipment themselves, many of the course


CHEMICAL ENGINEERING EDUCATION
























Aage Fredenslund received BS, MS, and PhD ('68)
degrees from the University of Wisconsin. He has taught
unit operations, transport phenomena, and ChE thermo-
dynamics at Instituttet for Kemiteknik since 1968. His
research interests include high pressure vapor-liquid
equilibria, PVT properties of mixtures, and multicom-
ponent separations.

objectives could not be achieved. Later on in the
curriculum, the students have a chance of con-
structing their own equipment during (required)
senior thesis work.
Altogether 27 experiments have been designed
and constructed, and these experiments are di-
vided into nine groups, each containing three
similar (but not identical) experiments. The
students must not have more than one experiment
from each group. The experimental units are de-
scribed briefly below.
Before each experiment is to be performed,
the students are briefed as to the operating con-
ditions and the report requirements. A variety of
possibilities, is built into most experiments. It is
found that the students can carry out the experi-
ments with the aid of the laboratory manual2
without much further supervision and that they
find the experiments quite challenging. The cor-
rected reports are, of course, discussed with the
students, who at the end of the course receive a
"pass" or "fail" on the basis of the reports.
The laboratory course is housed in two ad-
jacent localities: an apparatus hall of ceiling
height 7 m, containing a small area with ceiling
height 16 m, for pilot scale experiments and an
ordinary laboratory for bench scale experiments.
Both locations are provided with ample steam,
water, gas, and electrical supply.

EXPERIMENTS
A short abstract is given for each experiment
below. A capital letter in the experiment number


(e.g. 1A) indicates that the experimental unit is
placed in the apparatus hall, and a small letter
(e.g. ib) indicates that the experimental unit is
located in the ordinary laboratory.
1. FLUID FLOW. Flow of water in pipes. Flow of
water in tubing. Flow of air in ducts.
2. FLOW OF FLUIDS THROUGH POROUS MEDIA.
Filtration. Fluidization. Flow through packed columns.
3. EVAPORATION AND CONDENSATION. Evapora-
tion in a vertical tube. Evaporation in a vertical tube.
Condensation.
4. HEAT EXCHANGE. Heat transfer in pipes. Heat
transfer in pipes. Unsteady state heating of water.
5. DISTILLATION. Distillation in a bubble cap
column. Simple and batch distillation. Continuous distil-
lation.
6. ABSORPTION. Absorption in a packed column.
Absorption in a bubble column. Absorption in a sieve tray
column.
7. SIMULTANEOUS HEAT AND MASS TRANSFER.
Drying. The wetted wall column. Air humidification in a
spray tower.
8. EXTRACTION. Extraction in a rotaing disc
column. Extraction in a reciprocating plate column. Ex-
traction in a mixer-settler.
9. OTHER UNIT OPERATIONS. Preparative gas
chromatography. Reverse osmosis. Crushing and grinding.
The experiments do not, of course, cover the whole
field of unit operations. The very important area of crys-
tallization is, for example, omitted. However, they should
ensure that the students come in close, practical contact
with a broad spectrum of chemical processing equip-
ment.
REMARKS
The experience with the course has generally
been good. The students and faculty seem to find
the course an interesting worth-while experience.
As mentioned above, one argument against a
course of this type is that using finished, fixed
experimental units does not leave much room for
student initiative. However, this was recognized
as a danger from the very beginning of the
planning, and attempts have been made to make
the course as interesting and challenging as pos-
sible in other ways. Where possible, large scale
glass equipment is used so that one may visually
observe the phenomena of interest. Adequate in-
strumentation has been provided so that many
tedious measurements are avoided and so that
the students may concentrate on the central prob-
lems (on the other hand, automation is kept to a
minimum as "push-button experiments" are not
desired). In addition, the fact that most of the
experiments are concerned with separation pro-
cesses, a specialty of chemical engineering, stimu-
lates interest.
(Continued on p. 152)


SUMMER 1973










AN EVOLUTIONARY EXPERIMENT


A. MEISEN
The University of British Columbia
Vancouver 8, B.C., Canada


M ANY CHEMICAL ENGINEERS are involved
in the development of industrial processes
which consist of several articulated operational
steps. Since data for such development are fre-
quently lacking and are only obtainable through
experimentation, the engineer must be capable of
devising experimental equipment and procedures.
The usual undergraduate laboratory courses
do not prepare the engineering student well for
such tasks. Most experiments are intended to
demonstrate a single rather than a sequence of
concepts or operations, and their interdependency,
which is so essential for industrial processes, is
not apparent. Since the experimental apparatus
is usually provided, the student is primarily re-
quired to follow an established procedure and
analyse his results. He plays virtually no role in
selecting the experimental equipment and tech-
niques.
Hence, in order to give students some experi-
ence with developing a process, an "Evolutionary
Experiment" was recently introduced into an ex-
isting, Senior laboratory course at UBC. The term
"evolutionary" suggested itself because students
worked on the process in turn and it thus evolved
during the academic year. The present note de-
scribes an Evolutionary Experiment on electro-
winning of copper and emphasizes the organ-
izational rather than technical aspects. This
approach was taken because the latter are thought
to be of less general interest.

ORGANIZATION
The class was divided into groups of three or
four students and each worked on the project for
two days spaced one week apart. Since only a
brief outline of the process was provided and
students were required to investigate all major
aspects in the course of the academic year, the
first group started by making a literature survey.
In addition it formulated a detailed work plan
and documented its findings in a technical report.
Subsequent groups always began by reading
previous reports and determining their specific


Axel Meisen received the BS degree from Imperial
College, the MS from Caltech and the PhD ('70) from
McGill University. His teaching and research interests
include air pollution control, process control, and design
of undergraduate experiments.

objectives commensurate with the general work
schedule. These decisions were discussed and
sometimes modified in a brief meeting with the
laboratory instructor before the groups pro-
ceeded. When experimental equipment had to be
built or modified, this could usually be accom-
plished during the week between laboratory
periods. The work of each group concluded with
writing a technical report and making recom-
mendations to future groups. The very last group
in the academic year prepared a summary report.

THE PROCESS
Due to time limitations, a simple process had
to be chosen and electrowinning of copper from
a leachable ore was selected for the first Evolu-
tionary Experiment in 1970. This process is quite
well understood and consists of three basic opera-
tional steps: ore leaching, purification of the leach
liquor and electrolysis to yield copper. A further
advantage of this process is the production of an
important, final product rather than an inter-
mediate requiring further chemical treatment.
The relevancy of this project was therefore
clearly apparent to the students.
Approximately 300 lbs. of ore were kindly
provided by the Anaconda Company from its
mine in Weed Heights, Nevada. The ore is readily
leachable with dilute sulphuric acid and yields a
liquor sufficiently strong for electrowinning. No


CHEMICAL ENGINEERING EDUCATION









The term "evolutionary" suggested itself because students worked on the
process in turn and it evolved during the year.


special problems of analysis arose since the acid
consumption and copper content of the rock or
leach liquor could be determined by titration and
atomic absorption spectroscopy, respectively.

ACHIEVEMENTS
Based on the literature survey prepared by
the first group, the second group decided that the
leaching operation should be conducted by either
percolating the acid upward or trickling it down-
ward through a fixed bed of ore. The important
variables were thought to be acid concentration
and flow rate. Temperature and rock size could
also be varied but were regarded as less signifi-
cant. The supplied rock was approximately -3
+5 mesh and was used in this form without
further crushing or screening.
The second group designed and assembled a
simple leaching apparatus whose main compon-
ent was a 3 in. ID, 2 ft. long glass column con-
taining the rock. The acid was delivered by a cen-
trifugal pump from a 10 gallon holding tank
through a valve and rotameter to the leaching
column from which it returned to the tank. The
piping, which consisted of polyethylene, was
arranged to permit operation in the percolation
and trickle modes. Samples of leach liquor were
withdrawn from the holding tank to determine
copper content and acidity.
Initial tests showed that the liquor flow rate
could not be kept constant and it was up to the
third group to rectify this problem. Careful ex-
perimentation revealed that small rock particles
became lodged in the valve thus restricting the
flow. After several other attempts which proved
unsuccessful, a by-pass was installed around the
pump. This allowed the valve to be opened more
fully and thereby reduced the chance of blockage.
The subsequent three groups studied the leach-
ing rate as a function of acid concentration, flow
rate and mode of operation. By applying Leven-
spiel's tests1, the results were found to be repre-
sentable by the unreacted-core model with the
major resistance to mass transfer lying in the
leached, outer layer of the rock particles. Hence
varying the flow rate and operational mode did
not significantly affect the leaching rate. The acid
consumption was almost stoichiometric with re-
spect to copper indicating that few other rock
constituents were attacked.


The sixth group was originally scheduled to
investigate purification of the leach liquor neces-
sary for electrolysis. However, since the iron and
particulate content of this liquor were unex-
pectedly low, the group concentrated on design-
ing an electrolytic cell and washing the leached
rock. The latter ensued from the realization that
copper sulphate adhering to the rock constituted
an economic loss and environmental hazard if
discharged. Washing with water was shown to
be complete in less than one hour.
The electrolytic cell consisted of a 3 in. by 5 in.
lead anode and similar copper cathode situated in
a rectangular, plastic tank. The spacing of the
electrodes was variable and the leach liquor was
continuously passed between them by letting it
overflow the anode and discharge through the
bottom of the cell. Poor liquor distribution re-
sulted and the evolution of gas bubbles interfered
with the electrolysis. These problems were re-
solved by the seventh group which modified the
cell by introducing the electrolyte at the bottom
and forcing it to flow upwards between the elec-
trodes. The effects of flow rate, electrode spacing
and current density on copper deposition were in-
vestigated and current efficiencies in excess of
90% were achieved.
The final group prepared a summary report
and indicated areas requiring further work.
Furthermore, it considered the problems asso-
ciated with scale-up of the laboratory data.

STUDENT REACTION
Student response to the Evolutionary Experi-
ment was quite favourable because it provided a
break from the more traditional laboratory work.
They enjoyed the flexibility of the project and the
ability to formulate their own objectives. Since
each group started where the previous one had
left off, the work seemed more original than
usual. Finally, students appreciated the oppor-
tunity to study an industrially significant process
and gain practical experience with developing ex-
perimental equipment.
Since each group worked on a different aspect
of the Evolutionary Experiment, students recog-
nized the necessity for clear and concise technical
reports. Needless to say, they were not overjoyed
by this realization, but it made the task easier.
(Continued on p. 147)


SUMMER 1973










A FORCED CONVECTION DEMONSTRATION

USING SOLID CO2 SUBLIMATION


D. A. MELLICHAMP and 0. C. SANDALL
University of California
Santa Barbara, CA 93106

One of the features of the transport processes
sequence presently taught to chemical engineer-
ing undergraduate students at UCSB is the
weekly laboratory which is used to illustrate
selected principles from the lectures. Experi-
ments performed during the laboratory period
usually take the form of a demonstration where
data are taken to be analyzed by the students in
an assigned home problem. In this way many of
the home problems cover a practical transport
problem involving the analysis of real data.
The department sub-sonic wind tunnel is used
for the majority of these demonstrations. Hence,
in the fluid dynamics course the demonstrations
start with simple air stream velocity measure-
ments, cover the standard demonstrations of
drag on a bluff object, boundary layers, etc. In
the course on heat transport, demonstrations
cover such topics as heat transfer from a cylinder
in transverse air flow.
In the concluding course dealing with an-
alogous mass transport phenomena, the difficul-
ties encountered in designing appropriate demon-
strations are significantly greater. The authors,
in a recent paper', described an experiment de-
veloped by students as a term project which
covers mass transfer from a cylinder in trans-
verse air flow. In this experiment the cylinder is
cast from naphthalene with a liquid nitrogen
quench to obtain a very fine grain structure at
the surface of the cylinder. The low sublimation
rate of naphthalene, even under conditions of
forced convection, requires running times in the
wind tunnel on the order of a full day to achieve
measurable material loss from the cylinder. The
advantage of the naphthalene cylinder experi-
ment, however, is that simple mechanical methods
can be used to measure accurately the rates of
mass transfer. These data can then be compared
to analogous data from heat transfer experi-
ments.


Obviously this experiment requires too much
time to serve as an effective demonstration. Con-
sequently, we have developed a complementary
experiment, utilizing a dry ice cylinder, to furnish
a rapid visual demonstration of mass transfer in
transverse air flow. Solidified carbon dioxide has
a much higher vapor pressure than most common
solids; hence, with a vastly increased driving
force for mass transfer, wind tunnel demonstra-
tions can be run in several minutes. A further
advantage of the use of a dry ice cylinder is that
normally there is enough moisture in the ambient
air which condenses in the vicinity of the cylinder
to provide effective visual evidence of boundary
layer formation and separation, vortexing in the
cylinder wake, and the flow patterns in the vicin-
ity of the rear stagnation point.
The experiment is quite simple to carry out.
A mount (shown in the accompanying figure)
supports the cylinder in the wind tunnel test sec-
tion. The mount is adjusted to hold the cylinder


Figure 1
Dry Ice Cylinder Mounted in Wind Tunnel.

CHEMICAL ENGINEERING EDUCATION























Orville C. Sandall is currently an assistant professor
in Chemical Engineering at the University of California
at Santa Barbara. He obtained his education at the Uni-
versity of Alberta (BSc, MSc) and the University of Cali-
fornia at Berkeley (PhD). His teaching and research in-
terests are in the areas of heat and mass transfer. (left).
Duncan A. Mellichamp is an assistant professor in
Chemical Engineering at the University of California at
Santa Barbara. He received the BChE at Georgia Tech,
studied one year at the Technische Hochschule Stuttgart
(Germany), and obtained the PhD at Purdue University.
His present interests are in the fields of process dynamics
and automatic control. (right).

in compression with dense foam rubber (in our
case, rubber backed carpeting) gaskets used to
insulate the cylinder from the mount and to
maintain the compressive force as the ends of
the cylinder sublime. Preparation of the cylinder
is very simple, if somewhat novel. An ordinary
three pound block of dry ice is set-up in our ma-
chine shop metal lathe. It is quickly turned to
the required diameter by standard machining
techniques and immediately brought to the wind
tunnel for the demonstration.
After mounting the dry ice cylinder in the
wind tunnel the air flow is turned on and is
quickly adjusted to correspond to the desired
Reynolds number. It was found that at prevailing
air relative humidities of approximately 50%, the
streamline patterns of condensed moisture were
clearly visible at air velocities of approximately
50 ft./sec. For the 2-inch diameter cylinders used
in the demonstration, this corresponds to a Rey-
nolds number of about 50,000. At this Reynolds
number the laminar boundary layer separates
before it becomes turbulent, the point of separa-
tion occurring at an angle of about 80 degrees
from the forward stagnation point. The stream-
line patterns clearly show the separation point
and the angle of separation is easily estimated
by the students to be at approximately 80 degrees


The department sub-sonic wind tunnel
is used for demonstrations in fluid
mechanics and heat and mass
transport phenomena.


fro mthe forward stagnation point. The stream-
lines in the downstream turbulent wake are also
clearly visible particularly near the rear stagna-
tion point.
After running the demonstration for about
five minutes the wind tunnel is turned off and the
dry ice cylinder may be inspected. This length of
time is sufficient for a protruding ridge to appear
at the separation point. This ridge indicates the
sharp minimum in the local mass transfer co-
efficient that occurs at the point of boundary
layer separation.

REFERENCE
1. Sandall, 0. C., and Mellichamp, D. A., "A Simple
Forced Convection Experiment", Chemi. Engi. Edu.
Vol. 5, 134-136 (1971).



MEISEN: (Continued from p. 145)

Report writing was further simplified by the fact
that students did not primarily write for the in-
structor but rather for their class-mates whose
technical competence they knew.

CONCLUDING REMARKS
Although it is clear that not all undergraduate
experiments should be replaced by Evolutionary
Experiments, the addition of one or two can con-
siderably enliven a laboratory course. In order to
maintain student interest, the topics should be
frequently changed. The following projects, which
have either been conducted or are planned at
U.B.C., may serve as further examples of Evolu-
tionary Experiments: production of crystalline
copper sulphate from an Arizona ore, extraction
of protein from fish meal, manufacture of fur-
furaldehyde from sawdust and recovery of metals
from scrap tin cans. The latter two projects were
initiated by Dr. K. B. Mathur and Dr. A. P.
Watkinson, respectively.

REFERENCE
1. 0. Levenspiel, Chemical Reaction Engineering,
p. 338, John Wiley and Sons, New York, 1962.


SUMMER 1973











AN INTEGRATED REACTOR ENGINEERING


LABORATORY



R. D. WILLIAMS
University of Arizona
Tucson, AZ 85721


Chemical Engineering is unique among other
engineering specialties in that its basis is in
chemistry. Since this is so and since chemical
rate phenomena are an important part of chem-
istry, the body of knowledge including not only
chemical rate phenomena but also the coupling of
such phenomena with physical processes is worthy
of intensive coverage in the training of chemical
engineers.
Two pressures familiar to academicians in-
volved in curricula review are the pressures from
outside the University (industry) to make the
curriculum more relevant and practical, and pres-
sures from inside the university to make the
curriculum attractive to interested students.
These two pressures are not complementary in
that the former results in the addition of new
experiments or new laboratories and hence tends
to increase the rigor of the curriculum whereas
the latter results in just the opposite.
At the University of Arizona we have at-
tempted to compromise these considerations in
the area of chemical reaction engineering by
integrating as much as possible of relevant prin-
ciples, concepts, and techniques from the theory
course into a one unit laboratory in the semester
following the presentation of the theory. As will
be brought out, the number of items deemed im-
portant for inclusion into the lab necessitates
careful selection of experiments such that each
covers several of these important items. It is in
this sense that the term "integration" is used in
this paper and not in the sense that the theory
and lab have been integrated time-wise. This
paper will first discuss laboratory objectives and
then illustrate their implementation by giving
specific examples of experiments being conducted.

OBJECTIVES
In 1969 we conducted a poll of 152 departments of
chemical. engineering, principally in the United States


and Canada. The response to the poll was high (102/152=
67%) so that meaningful conclusions may be drawn as
to trends across the country. Of the 102 responding de-
partments, 61 stated that they currently had some lab
experience in kinetics and 41 did not. Of those who did,
only 8 had labs completely devoted to the subject and of
those who did not the majority (33/41) anticipated the
addition of such experience in the future.
The responding departments indicated that their most
popular experiments utilized single phase systems in
batch, CSTR, and tubular reactors. Almost as popular was
the heterogeneous catalytic type of reaction conducted
in a differential tubular reactor with analysis by gas
chromatography. From this it may be deduced that the
demonstration of reactor behavior with simple (single
phase) systems is generally of highest priority and that
to illustrate more complex (heterogeneous) systems the
differential reactor is being used, presumably due to its
simplicity, ease of analysis, adaptability and compatibil-
ity with gas chromatography.
The objectives selected for our laboratory are:
*To complement the theory course with practical ex-
perience.
*To provide a variety of experience in reactor types,
types of reacting systems, methods of data collection,
methods of data analysis.
*To provide a laboratory environment in which some
degree of success is assured.
The specific experience areas from the theory
course which were desirable for the laboratory
were:
1. Reactor types.
A. Batch. Homogeneous isothermall, adiabatic).
heterogeneous slurry.
B. Continuous stirred tank.
C. Continuous integral tubular.
D. Continuous differential tubular.
2. Reacting Systems Types.
A. Homogeneous.
B. Heterogeneous catalytic.
C. Heterogeneous noncatalytic.
3. Data Collection Methods.
A. Direct rate monitoring. Titration. Gas chroma-
tography. Optical measurement.
B. Indirect rate monitoring. Temperature meas-
urement. Pressure measurement.
4. Data Analysis Methods
A. Integral method.
B. Differential method.


CHEMICAL ENGINEERING EDUCATION























Richard D. Williams has been at the University of
Arizona since 1968. He studied at Texas Tech University
(BS) and obtained his doctorate in Chemical Engineering
at Princeton University. His current area of specializa-
tion is chemical reaction engineering.

The experiments which have been run using
homogeneous systems are listed below. Each of
these four experiments is run by all the student
groups and collectively they occupy about one-half
to two-thirds of the course:
1. Batch kinetics determination by direct sampling.
2. Prediction and experimental verification of single
and multiple CSTR performance.
3. Prediction and experimental verification of
packed and unpacked tubular behavior.
4. Batch kinetics by an indirect method-the adiaba-
tic reactor.
The heterogeneous experiments which have
been implemented are given below. Each student
group will take one of these experiments as an
independent project for the time remaining at the
end of the semester.
1. Hydrogenation of nitrobenzene on Pd-charcoal in
a slurry reactor, with indirect pressure measure-
ment.
2. Dehydrogenation and dehydration of IPA on Pt--
charcoal in a continuous microreactor, analysis by
gas chromatograph.
3. Noncatalytic TCC catalyst regeneration.
Each of the experiments will now be briefly
discussed giving its advantages to the lab.

EXPERIMENTS-HOMOGENEOUS
The first experiment involves the verification
of a postulated reaction order and determination
of rate constant temperature dependence for a
homogeneous reaction in a batch reactor. To date
we have used the ethyl acetate saponification re-
action. Figure 1 is a schematic of the experi-
mental apparatus which consists of a constant


Fig. 1. Reactor Bench









temperature bath and a three liter glass-stainless
steel reactor. Data is typically collected by direct
sampling and titration. The methods of excess
and/or half-lives may be used but in any case an
integral method is used for data analysis. Our
experience indicates that many students lack
sufficient lab technique to get good results with
this experiment. In accord with our objective of
providing an environment to insure some success
and especially in light of time limitations we are
considering changing this experiment (and the
two to follow) to automate the analytical tech-
nique.
The second experiment has been the experi-
mental study of the transient startup of a CSTR
sequence. Figure 2 illustrates our reactor bench
in more detail. Reactants are contained in two
pressurized 5-gallon polyethelyene carboys and
are passed through coils in the constant temper-
ature bath before being metered into the continu-
ous reactor being studied. The experimental re-
sults may be checked against theory by using
the reaction rate expression developed in Experi-
ment 1. Degrees of non-ideality may be controlled
by changing mixing RPM, reactor baffling and
nearness of inlet and outlet ports.


Fig. 2. Reactor Bench Detail


SUMMER 1973









The third experiment uses the same feed
system as Experiment 1 but in conjunction with
a jacketed glass tubular reactor. In this experi-
ment steady state conversion is obtained as a
function of mean residence time for both an open
tube and with the tube packed with 1/4" glass
Raschig rings. These first three experiments all
conducted on the same reactor bench serve to
give the student a better understanding of how
mixing in a chemical reactor determines reactor
behavior. Other experiments which could be run
on this very adaptable apparatus include resi-
dence time distribution determinations and
demonstration of steady state multiplicity. These
experiments are currently being prepared for
future use.
The last homogeneous experiment run was
chosen for several reasons. It demonstrates the
operation of an adiabatic batch reactor with an
exothermic reaction. Unlike the isothermal ex-
periments which precede it, this experiment re-
quires that an energy balance be made for data
analysis. Further, since the coupled material and
energy balances are nonlinear the integral method
of analysis will not work. Fortunately, the differ-
ential method comes to the rescue and is fairly
accurate since the continuous temperature-time
trace may be easily differentiated. The reaction
used is that between hydrogen peroxide and sod-
ium thiosulfate and unlike the ethyl acetate
saponification reaction it has a nonobvious stoi-
chiometry which may be experimentally deter-
mined. Figure 3 is a schematic of the experi-
mental arrangement.


THERMOCOUPLE
COLD JUNCTION


500 ML BEAKER

MAGNETIC STIRRER


10-2



_d(Tdt
(F- T)


TEMPERATURE
RECORDER


Fig. 3. Apparatus for the Adiabatic Reactor.

In a typical experiment the reactants are
mixed together and the sigmoidal temperature
increase with time is recorded. The temperature
rise will depend on the volume of the reaction
mixture and the amount of limiting reactant
present. If the volume is held constant (at 400 cc
for example) and the initial reactant ratio is


3m
90
80
70
60
AT
(�C) 50
40
30
20
10
0


0 1 2 3 4 5
VOUE OF 2 N H202 / VOUM OF 2 M NA2S203


6 7 8


Figc. 4. Temperature Rise as a Function of Initial Reactant Ratio.

varied then the temperature rise will go through
a maximum when the initial reactant ratio is
equal to the stoichiometric ratio. This is shown
in Figure 4 with student data from last year. The
different symbols correspond to different student
groups. From this graph it appears that of the
possible stoichiometrys listed, the appropriate
one is the last equation listed. Theoretically, it
can be shown that if the rate of temperature
change divided by the approach to the final tem-
perature squared is plotted against reciprocal
temperature an Arrhenius plot results (Figure
5). The experimental activation energy found
using student data compares very well with that


3,0 3.1 3.2 3,3 3,4
1000/T (�K)-1
Fig. 5 Arrhenius Plot for Na2S2O0-H20, Reaction

CHEMICAL ENGINEERING EDUCATION


2 N2S23 +H202= N62 06 + 2 WH
% NA0.0l0= NA2SA+N2O
3 NA2S03 + 4 = 2 NA2%06 + 2 N'O + 3 H20
&2S203 4 2 + N0~ = 2 6O 4 + 50 H









reported in the literature as shown. Table 1 gives
a more complete list of experimental values ob-
tained from student data compared with litera-
ture values. The agreement is quite good.
TABLE 1 COMPARISON OF STUDENT A.D LITERATURE VALUES


-AH
kcal/mole
VAiB -a2S203


Student 2 142 � 7
Literature 2 142.5


ko
E liters/mole-
kcal/mole sec

18.7 7.33 x 1011
18.28 � .3 b.85 x 1011


EXPERIMENTS-HETEROGENEOUS
The remainder of the experiments utilize
heterogeneous systems and each student group
will work with just one of these for the rest of
the semester.
An apparatus used to study the catalytic de-
composition of isopropyl alcohol (IPA) is shown
in Figure 6. Helium carrier gas is bubbled through


H Fig. 6. Microreactor. IPA dehydrogeneration and dehydration.
the IPA and then passes through a microreactor
containing Pt-charcoal catalyst. The reactor efflu-
ent may be sampled and analyzed by gas chroma-
tograph. IPA will decompose to give either pro-
pylene and water or acetone and hydrogen, de-
pending on reactor conditions, particularly tem-
perature. The temperature of the reactor is main-
tained by a sandbath and sampling is accom-
plished with a multiport sampling valve. This is
an easy experiment to run and demonstrates well
the reaction selectivity dependence on tempera-
ture, the use of a differential reactor for obtain-
ing initial rate data, and the use of a gas chrom-
atograph for analysis. The apparatus is very
flexible in that various different reactions and
catalysts may be used.
Another good example of a heterogeneous sys-
tem is the hydrogenation of nitrobenzene over


Fig. 7. Slurry Reactor. Hydrogenation of Nitrobenzene.
Pd-charcoal catalyst in a slurry reactor such as
depicted in Figure 7. We use a one liter Parr
autoclave with a gas storage volume and mercury
manometer though the experiment can be just
as well studied in glass as reaction pressures are
not high. Nitrobenzene and catalyst are charged
to the reactor before assembly. The air space over
the nitrobenzene is flushed with nitrogen and
then with hydrogen before pressurizing the sys-
tem with hydrogen by reference to the mano-
meter. To initiate the reaction, agitation is begun,
dispersing the hydrogen and catalyst into the
nitrobenzene. Hydrogen pressure is recorded as a
function of time from which reaction rate may


0,15





0.10

LN (P/P)



0.05


0 0 I I I I I I I I I I I
0 10 20 30
TIME (MIN.)
Fig. 8. Pressure ratio verses time and catalyst loading for nitro-
benzene18 hydrogenation.


SUMMER 1973
















0.10 -

Lu (PJ/P)



0.05 * CATALYST LOADING -
* = S0.5 GRAMS

0.05



0 10 20 :d
TIME (6IN.)
Fig. 9. Pressure ratio verses time and mixing rate for nitrobenzene
hydrogenation.

be calculated. Theoretically the expected behavior
is first order with the effective reaction rate con-
stant being dependent on temperature, agitation
rate, and catylyst loading. Figures 8 and 9 illus-
trate the type of data which is obtained. The first
order behavior is verified and rate constant de-
pendence on catalyst loading and agitation rate is
shown. Figure 10 summarized the results of
Figure 9, giving the reaction rate constant as a
function of mixer RPM. The high RPM asymp-
tote corresponds to chemical reaction rate control
and the low RPM asymptote results from a dif-
fusion controlled regime. Data at temperatures
other than room temperature would allow for the
determination of the activation energy and pre-
exponential factor of the chemical reaction rate
constant. Empirical correlations for catalyst load-


250


200

(MIN.)
150


100


I ' I


200 500 750 1000 1250 1500


Fig. 1. Effective


rate constant verses mixing rate for nitrobenzene
hydrogenation.


ing and RPM (or mixing power input) are also
possible alternatives.
Other heterogeneous experiments which are
currently under development include the high
temperature, noncatalytic regeneration of coked
Thermofor catalytic cracking catalyst and the
leach recovery of metals (e.g., copper) from their
ores.

ACKNOWLEDGMENT
In developing such a laboratory one should be alert
for experiments which others have developed which have
proven to be successful and which complement the lab-
oratory objective. In this regard, I must acknowledge the
use of ideas of Drs. James B. Anderson at Yale and
Gordon B. Youngquist of Clarkson They have been espe-
cially helpful in suggesting experiments which we have
used successfully.


FREDENSLUND: (From page 143)
The stated course objectives appear to have
been met satisfactorily, although improvements
in the course are still being-and will continue
to be-made. Before starting the design of a
course of this type, the purpose of the course
must be very clear, since the equipment design
may vary a great deal with the objectives. These
objectives are likely to differ somewhat from
department to department.


ACKNOWLEDGEMENTS
The author wishes to thank all colleagues in Lyngby,
Lund, and Trondheim, who have contributed to the de-
velopment of the course.

REFERENCES
1. Crosby, E. J., "Experiments in Transport Phe-
moment", Wiley, New York, 1961.
2. Fredenslund, Aage, "Experiments in Unit Opera-
tions", Den private Ingeniofond, Copenhagen, 1972
(270 pp. in Danish).


CHEMICAL ENGINEERING EDUCATION


CATALYST LOADI N
= 0.5 GRAMS


' I


I I


I I








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