Front Cover
 Table of Contents
 Chemical engineering department...
 The educator, professor Joe...
 Chemical engineering division...
 The classroom: Common thermodynamics...
 The laboratory: Laboratory experience...
 Mass transport phenomena in the...
 Dynamic optimization
 Chemistry makes the chemical...
 Views and opinions: On what sort...
 Are chemical engineers selling...
 Book reviews
 Problems for teachers
 Back Cover

Chemical engineering education
http://cee.che.ufl.edu/ ( Journal Site )
Full Citation
Permanent Link: http://ufdc.ufl.edu/AA00000383/00019
 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: Winter 1968
Frequency: quarterly[1962-]
annual[ former 1960-1961]
Subjects / Keywords: Chemical engineering -- Study and teaching -- Periodicals   ( lcsh )
Genre: serial   ( sobekcm )
periodical   ( marcgt )
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-
 Record Information
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 01151209
lccn - 70013732
issn - 0009-2479
sobekcm - AA00000383_00019
Classification: lcc - TP165 .C18
ddc - 660/.2/071
System ID: AA00000383:00019

Table of Contents
    Front Cover
        Page i
        Page ii
    Table of Contents
        Page 1
        Page 2
        Page 3
    Chemical engineering department on Wisconsin
        Page 4
        Page 5
        Page 6
        Page 7
    The educator, professor Joe Koffolt
        Page 8
        Page 9
    Chemical engineering division activities
        Page 10
    The classroom: Common thermodynamics course for engineering sophomores
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
    The laboratory: Laboratory experience in transport phenomena
        Page 16
        Page 17
        Page 18
        Page 19
    Mass transport phenomena in the human circulatory system
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
    Dynamic optimization
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
    Chemistry makes the chemical engineer
        Page 32
        Page 33
        Page 34
        Page 35
    Views and opinions: On what sort of place, if any, theoretical and mathematical studies should have in graduate chemical engineering research
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
    Are chemical engineers selling their birthright for a place in the ivory tower?
        Page 41
        Page 42
        Page 43
        Page 44
    Book reviews
        Page 45
    Problems for teachers
        Page 46
        Page 47
        Page 48
    Back Cover
        Page 49
        Page 50
Full Text

0@uri thisiss
J~IOEKOcagO of

Professor, What Do You Think?

Process Design Oilfield Production
Technical Sales Plant Design
Refinery Engineering Development
Research Technical Service

With all the opportunities available today
you probably often hear this question from
your students. You can be a major factor
in his career.

assignments and advancement opportunities?
Standard Oil Company of California has
challenging assignments in just about any
area that would interest Chemical Engineers.

If you find yourself in this situation why These initial assignment
not consider an industry that can offer ability and can lead to a
a full range of Chemical Engineering in many areas.
Should you or any of your students wish additional
information on our industry or Company write to:
Mr. Robert E. Rodman
Coordinator, Professional Employment
Standard Oil Company of California
225 Bush Street
San Francisco, California 94120

ts will test their

Standard Oil Company of California
An Equal Opportunity Employer

Chemical Engineering Education


Department of Chemical Engineering
University of Florida
Gainesville, Florida 32601

Ray Fahien

Associate Editor:
Mack Tyner

Business Manager:
R. B. Bennett

Production Manager:
Rachel Albertson

Art Editor:
Ginger Ashley

Publications Board and Regional
Advertising Representatives:
WEST: William H. Corcoran
Chairman of Publication Board
Department of Chemical Engineering
California Institute of Technology
Pasadena, California 91109
SOUTH: Charles Littlejohn
Department of Chemical Engineering
Clemson University
Clemson, South Carolina 29631
EAST: Robert Matteson
College Relations
Sun Oil Company
Philadelphia, Pennsylvania 19100
E. P. Bartkus
Secretary's Department
E. I. du Pont de Nemours -
Wilmington, Delaware 1985'0
NORTH: J. J. Martin %
Department of Chemical Engineering
University of Michigan
Ann Arbor, Michigan 48104
CENTRAL: James Weber
Department of Chemical Engineering
University of Nebraska
Lincoln, Nebraska 68508


3 Editorial
4 Chemical Engineering Department
On Wisconsin
R. B. Bird
8 The Educator
Professor Joe Koffolt
10 Chemical Engineering Division Activities
11 The Classroom
Common Thermodynamics Course for Engi-
neering Sophomores,
F. S. Manning and L. N. Canjar
16 The Laboratory
Laboratory Experience in Transport
E. H. Wissler
45 Book Reviews
46 Problems for Teachers

Feature Articles
20 Mass Transport Phenomena in the Human
Circulatory System
K. H. Keller
27 Dynamic Optimization
W. F. Stevens
32 Chemistry Makes the Chemical Engineer
T. W. Tomkowit
36 Views and Opinions
On What Sort of Place, if any, Theoretical
and Mathematical Studies should have in
Graduate Chemical Engineering Research
R. Aris
41 Are Chemical Engineers Selling Their Birth-
right for a Place in the Ivory Tower?
R. H. Wing

CHEMICAL ENGINEERING EDUCATION is published quarterly by the Chemical
Engineering Division, American Society for Engineering Education. The publication
is edited at the Chemical Engineering Department of the University of Florida with
the assistance of the Publications Office of the Engineering and Industrial Experiment
Station. Application to mail at second-class postage rates is pending at Gainesville,
Florida, and at additional mailing offices. Correspondence regarding editorial matter,
circulation and changes of address should be addressed to the Editor. Advertising rates
and information are available from the advertising representatives. Plates and other
advertising material may be sent directly to the printer: E. O. Painter Printing Co.,
137 E. Wisconsin Ave., DeLand, Florida 32720. Subscription rates are $8.00 per
year in U.S. Copies of this issue printed, 3,200. Undeliverable copies should be
returned to the business address.


The world of Union Oil

salutes the world

of chemical engineering

We at Union Oil are particularly indebted to the colleges
and universities which educate chemical engineers.
Because their graduates are the scientists who contribute
immeasurably to the position Union enjoys today:
The twenty-sixth largest manufacturing company in
the United States, with operations throughout
the world.
Union today explores for and produces oil and natural gas
in such distant places as the Persian Gulf and Alaska's
Cook Inlet. We market petroleum products and petro-
chemicals throughout the free world.
Our research scientists are constantly discovering new
ways to do things better. In fact, we have been granted
more than 2,700 U.S. patents.
We and our many subsidiaries are engaged in such
diverse projects as developing new refining processes,
developing new fertilizers to increase the food yield, and
the conservation of air and water.
Today, Union Oil's growth is dynamic.
Tomorrow will be even more stimulating.
Thanks largely to people who join us from leading
institutions of learning.
If you enjoy working in an atmosphere of imagination and
challenge, why not look into the world of Union Oil?
Growth...with innovation. Union Oil Company of California.



Editorializing, philosophizing, polemicizing,
exorcizing, "exhortizing," proselytizing, prophe-
sizing, and all similar conventional activities of
an editor must wait for future issues. In this
issue, nothing is more important than saying
"Thank You" to the many people who have con-
tributed time and money to the publication of
These are:
Professor William Corcoran of California In-
stitute of Technology, for his leadership as
Chairman of the Publications Board and his
diligence in obtaining financial support from
numerous companies.
The other members of the Publications Board
for their support and for serving as our geo-
graphical advertising representatives in se-
curing donations and ads from industry.
Their names are listed on the first page.
Dean Bryce Andersen, for his support as
Chairman of the Chemical Engineering Divi-
sion of the American Society for Engineering
The companies that have generously con-
tributed to our support (see acknowledg-
The Chemical Engineering Departments that
have donated $25.00 each to the journal (see
The former editorial staff at the University
of Rochester who have helped make the tran-
sition smooth and have offered their advice
and support, and especially Professor Shelby
Miller for his dedicated efforts in publishing
Volume 1.
The Publications Staff at the University of
Florida, College of Engineering: Rachel Al-
bertson, Sandra McFarlan, Ginger Ashley.

The former publishers at the University of
Cincinnati of the Journal of Chemical Engi-
neering Education who have offered their
support of our publication.
The staff at the University of Florida, and
especially Professor Mack Tyner and Profes-
sor R. B. Bennett.
The authors of articles who have cooperated
by supplying us with material requested of
Our many "well wishers" throughout the
will continue to need the support of all these
people and of others if it is to thrive or even to
survive. The editors would especially like to urge
all of you to submit material to us for our
recurring departments:
Course outlines (no discussion needed)
Home problems, exam problems, and questions
of interest.
Views and opinions of general interest, in-
cluding guest editorials
Course descriptions and discussion
Book reviews (both before and after use)
News of conferences, new appointments,
changes in programs, etc.
New laboratory techniques
Your department of chemical engineering
(see "On Wisconsin")
An outstanding chemical engineering educator
(see "Joe and his Jewels")
As a requirement of NSF sponsorship, we
have agreed to publish the proceedings of the
Continued on page 39.

WINTER, 1968


Each issue, we will feature a department of
chemical engineering. We begin with a top-rated
department that has produced numerous out-
standing chemical engineering educators and


R. BYRON BIRD, Chairman

For many years the Chemical Engineering
faculty at the University of Wisconsin has been
split into three factions: the canoeists, the golfers,
and those who steadfastly refuse to join either of
the other groups. On most academic and admin-
istrative matters we usually have N + 2 opinions,
when N is the number of professors (the extra
"2" arises from the fact that several professors
usually change viewpoints along the way). Be-
cause of this lively lack of unanimity it is some-
times remarkable that we can ever get our vectors
lined up with a resultant component in the direc-
tion of progress. When we do, however, we are
fairly confident that the consensus is workable.
In what follows I shall attempt to outline very
briefly our conclusions on a number of points
related to chemical engineering teaching. Many
of these reflect the strong leadership our depart-
ment has had in the recent past, particularly that
of Professors Hougen, Ragatz, and Marshall.
Research is teaching
There has been far too much talk about re-
search VERSUS teaching. We feel strongly that
research is a vital departmental activity and that
the individual and small-group instructions in-
volved in research is one of our important teach-
ing activities. It also serves to keep the teacher
alert by insuring that he is faced daily with new
problems to which he does not know the answers,
that he is required periodically to present and
defend his ideas at technical meetings, and that
he is obliged to know what is going on in his area
of research in industry and other academic insti-
tutions. The teacher thus, in a sense, continually
puts himself in the role of a student and thus can
appreciate the problems that his own students
have when they encounter a new situation. Noth-
ing is more oppressive in an educational institu-
tion than a teacher who presides over a body of

stagnant knowledge and demands that his stu-
dents master the material obediently.
The flow of knowledge
It has generally been our policy that each
undergraduate course is backed up by a graduate
course, and that it in turn is backed up by a re-
search program. In this way there is a continual
flow of knowledge from the research laboratory
into the graduate course; often the person doing
the research also teaches the graduate course and
he is then free to experiment on new ways to or-
ganize and teach the material. Once the material
has been class-tested at the graduate level it can
be moved down into the undergraduate program.
The several undergraduate textbooks prepared
in our department have been developed by this
kind of procedure.
Attitude of "apartheid"
Our department has for many years gone on
the record as being opposed to the "common core"
idea in engineering education. We feel that such
regimentation can possibly lead to a lack of
flexibility and a lack of identity. Also, the strong
chemistry background of our students is not made
use of if they take common core courses in ther-
modynamics, fluid dynamics, materials science,
etc. Furthermore, it seems to us that students
should learn early in life the importance of mak-
ing a decision and accepting the consequences. If
a student makes the wrong curriculum selection
and has to change his course of study, it may be
that he will have profited from the experience
in decision-making. Finally we feel that it is
good for the students to identify themselves with
an academic department early, for the purpose
of developing esprit-de-corps and for advising
purposes. This is particularly important in a
large university. Our attitude of maintaining in-



Our attitude of maintaining
independence from the rest
of engineering should not be
interpreted as an indication of
disrespect or non-cooperation,
but rather as a professed de-
sire to be the connecting link
between chemistry and en-

Professor Roland Ragatz, former chairman, and Professor R. B. Bird, present chairman,
Department of Chemical Engineering, University of Wisconsin.

dependence from the rest of engineering should
not be interpreted as an indication of disrespect
or non-cooperation, but rather as a professed de-
sire to be the connecting link between chemistry
and engineering.

Importance of chemistry
The distinguishing feature of chemical engi-
neering, as opposed to other engineering, is the
strong emphasis on chemistry. We have main-
tained a substantial chemistry sequence in our
curriculum, and our students are in the same
courses as chemistry majors. We have not elimi-
nated analytical chemistry, because we feel that
the interface between analytical chemistry and
process control is an important one for future de-
velopment. We have tried to keep a strong chemi-
cal bias in all of our chemical engineering courses,
emphasizing wherever possible those problems
dealing with mixtures, chemical reactions, multi-
phase systems, molecular structure, polymers, in-
teresting compounds, chemical separations, and
ionic solutions. We are trying to make a con-
scious effort to stop talking about the famous
compounds "A" and "B" and use examples in-
volving real chemical systems. Our last six pro-
fessional staff additions have been purposely
made in such a way as to strengthen the chemical
orientation of our department. We are not trying
to imitate chemists nor are we trying to become
totally dependent on chemistry as a source of in-
spiration and guidance; but we must not be
oblivious to the great advances in chemistry in
the last two decades (the Westheimer Report, an
enlightening, easy-reading summary of the ad-

vances in chemistry since 1946, ought to be re-
quired reading for all ChE professors over 40).

Engineering emphasis
There seems to be misunderstanding in some
quarters about the engineering orientation of our
undergraduate curriculum. The publicity asso-
ciated with the development of our transport
phenomena course seems to have misled some
people into thinking that we have abandoned all
reason. We regard the transport phenomena
course as a third semester of physics, made neces-
sary by the fact that elementary physics includes
almost no material on fluid dynamics, heat con-
duction, and diffusion. We still include in our
curriculum two 3-credit lecture courses in unit
operations, a 5-credit unit operations laboratory
course, as well as courses in chemical reactor op-
eration, process dynamics, and process design. In
all of these courses the emphasis is very much on
solving problems of engineering interest. The
laboratory instruction in chemical engineering
includes: transport phenomena, unit operations,
applied electrochemistry, process control, and
polymer processing; all of these except polymer
processing are required. This laboratory instruc-
tion is quite substantial and we feel that this is
essential in maintaining an engineering empha-

Importance of undergraduate instruction
Our department pays more than just lip ser-
vice to the undergraduate instructional program.
Almost every staff member participates actively
in undergraduate teaching and advising. With an

WINTER, 1968

The publicity associated with the development of our transport
phenomena course seems to have misled some people into
thinking that we have abandoned all reason. We regard the
transport phenomena course as a third semester of physics, . . .

undergraduate enrollment of about 350, we have
to devote a substantial part of our effort to course
planning, instructional equipment, course notes,
supervision of teaching assistants, and lecture
preparation. We are also trying more and more
to assign extra time when needed for course im-
provement. All undergraduate courses are given
each semester, and enrollments in some courses
are as high as 50 to 80. We have experimented
with large lectures, small sections, and various
"intermediate forms of instruction. We have
found supervised problem-working sessions to be
of value in some courses: in these, a portion of
the homework is done under the guidance of a
teaching assistant who circulates around the
room and gives advice where needed. We have
one standard curriculum for all students. How-
ever, those with a grade-point average of 3.5/4.0
may elect to replace any 6 credits of chemical
engineering courses by 6 credits of any science
or engineering courses. We do use quite a few
teaching assistants (about 24 to 30 quarter-time
graduate students) mostly for taking care of
laboratories, problems sessions, and paper grad-
ing; occasionally they are given major lecturing
assignments as well.

Graduate courses
Most of our graduate courses have a strong
science and research flavor. They are intended
to be of interest primarily to the Ph.D. candidate,
who is preparing himself for research. We have
never developed a strong terminal MS program at
Wisconsin and very few of our courses are suit-
able for those not seeking the doctorate. The
number of graduate courses we offer is purposely
kept rather small. We want the few courses we do
offer to be well-organized and up-to-date. We
encourage our students to take courses in the
basic sciences or other engineering departments
so as to bring new ideas into chemical engineer-
ing. We have no course requirements in chemical
engineering for the Ph.D. We have quite a few
small seminars in the department and auditing
of courses is widespread. In summary, we oppose
formal course proliferating in engineering at the
graduate level.

Graduate examination procedures
Prior to the final thesis examination, we have
three formal graduate examinations in chemical
engineering. The MS examination can be an ex-
amination on an MS thesis. Otherwise it is de-
voted to the critical presentation of a recent
article in one of four chemical engineering journ-
als. This type of an examination hopefully en-
courages some familiarity with the technical
literature and also helps to bring new work to
the attention of the staff. Rather than being a
teacher-vs.-student exam, it is more teacher +
student vs. someone else's research. The quali-
fying examinations (beginning of third semester)
are four 4-hour tests on basic undergraduate ma-
terial: transport phenomena, thermodynamics,
process dynamics, and chemical reactors and
kinetics. These are intended to insure that we are
not turning out students with poor foundations
covered with a thin veneer of high-powered,
science-oriented graduate material. The prelimi-
nary examination (beginning of fourth semester)
consists of a report, about 100-200 pages, on spe-
cific plans for the Ph.D. thesis research, including
basic theory, literature survey, detailed equipment
plans, estimated costs, and time schedule. The
purpose is to insure that the candidate has re-
search potential and that the problem is realistic
and of finite duration. I think most of us also
feel that it is to some extent an examination of
the major professor. Often some very good ideas
come out of the two-hour oral presentation of
the report.

Foreign language requirements
At Wisconsin the language requirements are
left pretty much up to the individual departments.
We currently require either the traditional mini-
mal reading requirement in two languages or else
advanced competence in one. We allow any lan-
guages to be used, recognizing that some want
the competence as a research tool, whereas some
may wish to train themselves for an overseas as-
signment. Still others may wish to capitalize on a
foreign language spoken at home in their youth.
There seem to be two major problems at the pres-
ent. One is that the language departments have


gone over to machine-graded tests which we sus-
pect do not encourage the right motivation for
language study. The second problem is that most
undergraduate engineering curricula do not re-
quire foreign language study. We have recently
made one change in our curriculum aimed at en-
couraging foreign language training: we allow
students who have had two or more years of a
foreign language in high school to continue that
language during their freshman year in lieu of
freshman English.

Professional staff
We believe that it is in the best interests of
the students to provide for them a staff with
widely varying backgrounds (in addition to golf
vs. canoeing). For example, as regards the indus-
trial experience of our professors we have a spec-
trum going from 0 years up to 15 years. We have
some who specialize in research, others who spec-
ialize in teaching. We have some with strong ties
to chemistry, but others with strong ties to elec-
trical engineering, biomedical sciences, metal-
lurgy, mechanics, etc. About 4/5 of the staff have
Ph.D.'s (or Sc.D.'s) in chemical engineering, but
1/5 got their doctorates in chemistry or polymer
science; we feel that having about 20 percent to
25 percent of the staff with their doctoral training
in a related field can bring in many new ideas and
viewpoints. But the one thing we require of all
of our staff members is independence. We do our
best to hire new professors in fields not already
covered by the present staff so that the newcomer
will develop his own niche. We want our students
to have a diverse group of experts available to
them as consultants.
The above items we seem to have reached
agreement on. But, like all departments, we have
a number of controversial problems as yet un-
solved. One perennial problem is that of report-
writing; everyone (students, T.A.'s, professors,
and employers) agrees that there is a serious
problem here and numerous remedies have been
applied. Part of the blame possibly rests with
the high schools, but much of it is doubtless a re-
sult of the unfavorable student-to-teacher ratio;
expert writing is a result of long, careful tutelage,
and I doubt that it can be mass-produced.
Another problem is that of graduate-student
support. All departments face the annual job of
matching fellowships with students. Inequities
seem to be inevitable because of allowances for

dependents, income tax regulations, tuition re-
funds, eligibility for supplementation, etc. About
the only point we seem to agree on in our depart-
ment is that no supplementation (aside from
quarter-time teaching for NSF fellows) will be
allowed for first year graduate students. We do
not believe that supplementation, travel expenses,
or other enticements should be part of the gradu-
ate recruitment activity. Students should select
their graduate school on the basis of the program
and the facilities.
Another problem is that of postdoctoral re-
search. We get many letters from persons seek-
ing postdoctoral appointments. We have to turn
most of these down for lack of funding. In many
instances the persons would do better to get in-
dustrial experience, but many of the requests are
legitimate. A postdoctoral year is valuable for
persons switching from industry to teaching, or
from one teaching position to another. Postdoc-
toral research during a sabbatical year can be
quite stimulating. Postdoctoral research in a de-
partment can often be used to spearhead a new
area or to provide an extra push in a graduate
research program. We certainly have not dis-
cussed this matter enough.
Of continual concern are the potential new
areas of chemical engineering. I doubt if we do
enough experimentation and exploration in trying
to bring in new subject material and techniques
into chemical engineering. We have been far
too slow in emphasizing colloidal phenomena,
polymer processing, catalysis, multiphase systems,
and other subjects whose importance seems to be
well recognized in industry. We probably do not
spend enough time on this at the departmental
Needless to say the problem which concerns
most of us is time. One wonders whether the
leisure days in the ivy-covered halls ever really
existed. The faculty member today has enormous
demands put on his time: research, teaching, pro-
posal-writing, continuing-education programs, in-
dustrial consulting, attendance at meetings, re-
viewing of research proposals, etc. We must in
the near future seek new ways of insuring that
staff time is being effectively utilized. Finally
there should be enough time left over for the
canoeists to convert the golfers, or to discuss the
relative merits of making popcorn by transport
phenomena methods or by the unit operations ap-

WINTER, 1968


In this issue, our featured chemical
engineering educator is Professor Joe
Koffolt, chairman of the Department of
Chemical Engineering at Ohio State Uni-
versity, who writes fifty letters a month
to his former students-"his jewels." This
article was submitted to us by Professor
Aldrich Syverson of Ohio State University,
Columbus, Ohio.


and his


Dr. Joseph H. Koffolt is entering his 39th year
of teaching chemical engineering at Ohio State
University, Columbus, Ohio. "There is no simi-
larity between what we taught ten years ago and
today," notes Koffolt, chairman of the department
since 1948,
Chemical engineering began at Ohio State in
1902, the same year Koffolt was born in Cleve-
land. In 1924 he received the department's 310th
chemical engineering degree and next year he
will hand out degree number 2700. Koffolt's
teaching career spans more than half the time his
subject has existed.
Chemical engineering, he says, evolved from
industrial chemists who were good pipe fitters and
Koffolt, smiling, recalls "putting on long pants
and lying about my age" when, at 14, he went to
work for Union Carbide as a block grinder. "Nine
cents an hour, ten hours a day-it was just a
summer job, but Dad thought I was doing pretty
good," grins Koffolt through a haze of Ibold
cigar smoke.
Things had improved a bit by June, 1924,
when Koffolt got his first job after graduation.
He worked for Industrial Rayon Corporation in

Cleveland. His starting pay was 43 cents an hour,
"with a chance to work up to 45 cents." When
he started, experienced sniffers and tasters were
responsible for solution strengths. He adapted
nomographic (alignment) charts to the business
so that if a man could read, he could run the
By making what he calls "relatively simple"
changes in equipment he was able to increase pro-
duction from 250 to 5,000 pounds of rayon per
day, with no increase in men. "I did quite a bit of
good there," he muses. Koffolt still uses some of
his notes, "disguised and dummied up," to pose
problems for students.
Koffolt, author of a book on "application" of
chemical engineering, has a long list of papers to
his credit. Among his consulting activities have
been fire and explosion investigations. Asked
what the usual causes for these were, he replied
"damn fools who are supposed to be experts."
Highlight of his professional activities is his
term as vice chairman of the membership com-
mittee of the American Institute of Chemical En-
gineers. When he took office, only about 150
men ("the majority of them from Ohio State")
belonged. By the end of his term he had boosted


membership to about 3,000, a feat which netted
him the society's "founder's award" in 1963.
"Why, that group was so poorly publicized that
when I was in school I thought it was a secret so-
ciety and you had to know the password," he
Koffolt has belonged to the American Society
for Engineering Education since 1933 and, in the
chemical engineering division, has held every
office but one.
Koffolt's office walls are lined with pictures of
his former students. He also has a small mineral
collection close to his desk. Both are important
to him.
Of the alumni, he says: "Here-these men,
the graduates-are the real highlight of it all."
And, of his minerals, he says: "I like rocks, only
we call them minerals. Look here, and here, see
how each one has different characteristics, is
shaped differently and intricately? I think, look-
ing at these rocks, that God must have had a lot
of fun when He created the world."
Koffolt is willing, even anxious to talk about
his alumni and their accomplishments. I believe
we have the strongest alumni group in the coun-
try," he declares. "They're a close-knit, enthusias-
tic group."
"Our support from industry is amazing," he
boasts, naming donations like chemicals, labora-
tory equipment, money, a computer, and some-
times even borrowed brainpower. Laboratory
fees, he declares with pride, are the same as they
were in 1924.
Since 1958, Koffolt has secured for his depart-
ment more than $300,000 in contributions and
is credited with "getting" the modern chemical
engineering building. Since he has been chairman
of the department, he has also written and sent
an "annual report," sometimes over 30 pages long,
to his alumni.
How is it that Koffolt is so successful getting
money from his alumni; how does he know so
much about them, keep in touch so well? For Ko-
folt, the answer is simple. "I decided when I
started to teach that I owed an obligation to the
children of the state. I was going to know every-
body I taught and not forget them."
And, though he may not remember every
one, he cheerfully talks at length of his alumni.
Like Cornelia, he refers to them as his "jewels."
Obviously enjoying himself, Koffolt points to a
a picture on his wall and says "There's Bob Bates;
he founded Chemineer, and sometimes when he
consults he recommends his competitor's equip-
WINTER, 1968

ment. And Harry Warner, president of B. F.
Goodrich. Parker Dunn-he was in my first
graduating class-is president of American Pot-
ash. Dale Barker there is head of Chemical Ab-
stracts, and Herb Barnebey is president of Barne-
bey-Cheney, an activated carbon manufacturer.
"Cy Porthouse is president of Dunhill. He's
contributed over $20,000 to the department, and
he once raised two million dollars in two days.
His father was a bricklayer. Edgar C. Bain is
retired, but he became vice president for research
of U. S. Steel and has a research laboratory
named after him. I remember one graduate who
just made it with a 2.01 grade average and no one
thought he would go far. But he had a lot of
common sense and a good feel for things and now
he's manager of one of the world's largest chemi-
cal plants."
Koffolt's alumni are generous. One man, re-
sponding to a money request, came to his office,
called him a "pipsqueak," and gave him $10,000
worth of stock. Another, in his will, left the de-
partment $75,000.
Koffolt writes about fifty letters a month to his
jewels. Grinning, he points to a dictaphone and
says "that thing is a godsend." He sends 700
Christmas cards, and can recall when he wrote
personal notes on each one. "I can't do that any-
more," he sighs.
Asked why he was made chairman of his de-
partment, he chuckles and replies, "Because I
knew all the rules." Seriously, he says he accepted
because he wanted to increase alumni ties, which
he calls "our most important asset." He also
wanted to improve teacher retention, and is proud
of only two resignations in almost twenty years.
And he has distributed the teaching load better.
He recalls that before he was made chairman, he
had more than forty graduate students. This, he
felt, was "very wrong . . . very unfair to the
"When I was made chairman," he continues,
"I decided that every one I hired had to be
smarter than I was."
On peeves, Koffolt barks "Too damn many
forms." And his greatest failing? "I talk too
much." Asked about hobbies, he replies "Really,
my hobby is people. I like them. Every person is
different, and they're all good."
Koffolt claims his greatest accomplishment is
his relationship with his jewels. His alumni are
located in most states, and in some forty countries
around the world. He brags: "I can go about any-
where and call an alumni meeting." He is also



The Chemical Engineering Division of ASEE
serves the interests of chemical engineering fac-
ulty and others concerned with the education of
chemical engineers. In this period of intense re-
examination of GOALS and goals, the Division
serves as a liaison with other engineering fields
within ASEE. In all of its activities, the Division
tries to coordinate its efforts with the education
committees of AIChE.
After a stimulating and well-attended Sum-
mer School for Chemical Engineering Teachers
held in June at Michigan State, the Division has
begun planning for the next Summer School to
be held about five years from now. Suggestions
on topics, format, and location are welcome.
The Division sponsors a full program on
chemical engineering education at each annual
meeting of ASEE. Next June in Los Angeles,
there will be sessions on "Frontiers in Chemical
Engineering" and "New Approaches to Teaching
Chemical Engineering." In addition, there will
be the annual Distinguished Lecture, a depart-
ment chairmen's meeting, a luncheon, and a ban-

In order to serve a broader segment of chemi-
cal engineering faculty, the Division has begun
sponsoring sessions at AIChE annual meetings.
A symposium on Case Problems was presented
at the New York meeting, and another session
is planned for the Washington meeting in 1969.
Potentially one of the most important func-
tions of the Division is its sponsoring the jour-
nal, Chemical Engineering Education. After sev-
eral years of considerable effort by many people,
the journal is now established on a sound finan-
cial and editorial basis. It should serve as an
effective means of communication among chemi-
cal engineering faculty.

Continued from page 9.
proud of the 75 chemical engineering professors
his department has produced.
What makes Koffolt angry? "These damnfool
sign carriers with the big beards," he exclaims,
adding "also professors, who are supposed to be
professional people, who won't cross a protest line.
This makes me mad." Of war he observes that,
"We'll never do away with greed. There is free
will. There will always be jackasses."
Koffolt is candid, though optimistic, about the
future of chemical engineering. "We don't know
what's going to happen. Materials are selling now
that were unknown a decade ago. We haven't
discovered everything yet," he smiles. The future
looks bright, he thinks, "but not smooth."
Petrochemicals, the computer, and synthetics
are "exciting" things in chemical engineering for
Koffolt. Petrochemicals are important because,
he predicts, "This is the way we're going to lick
the food problem." Koffolt, criticizing chemical
engineering somewhat, notes sadly that "It is still
about half art, half science." He would prefer

that science outweigh art.
"Quite often we don't know what's hap-
pening," he admits. "Thirty years ago no one
thought of using rayon in tires. And the first
pair of rayon panties-when they were washed
and hung out to dry, they stretched out to about
two feet."
Asked for a funny story, for which he is noted,
Koffolt bowed out gracefully, quipping "My
stories come like a Quaker talk-when the spirit
moves me."
Why do chemical engineering alumni offer
such strong support to the department, Ohio
State, and Koffolt? Perhaps it is because, as one
jewel wrote in a letter to Koffolt, "if it hadn't
been for you and the department, I would prob-
ably have been a pants-presser like my father all
my life." To this, Koffolt adds "I think they ap-
preciate the interest we take in them."
How do Koffolt's jewels view him? "As Joe."
How does he view his alumni? "Like second



(Use of Programmed Learning Material).

Common Thermodynamics Course

For Engineering Sophomores*

Associate Professor of Chemical Engineering
Carnegie Institute of Technology
Pittsburgh, Pennsylvania 15213
Chrysler Professor and Dean of Engineering
University of Detroit
Detroit, Michigan 48221
A macroscopic-oriented course in classi-
cal thermodynamics for all second-semester
engineering -sophomores at Carnegie Tech
is described. There was good agreement on
course content; however mechanical engi-
neers tended to emphasize availability and
irreversibility, while chemical engineers
desired increased coverage of property esti-
mation and reduced correlations. Chemical
engineers preferred comparatively lengthy
problems which closely reflect industrial
practice and thus include engineering facts
of life as well as basic principles. Other
faculty recommended shorter, more mathe-
matical problems which often isolate and
illustrate a single basic concept.
Lectures in introductory concepts, work,
and temperature were replaced by pro-
grammed material with approximately 20
percent saving of time. Student reception
was good and their depth of understanding
compared favorably with that taught by
conventional means.

An introductory thermodynamic course com-
mon to all second-semester engineering sopho-
mores at Carnegie Tech was initiated in 1965.
The primary objective was to present the student
with as broad and general approach as possible

*Presented at the Annual Meeting of ASEE, June
19-22, 1967.

instead of the more conventional "denomina-
tional" methods which all too often are confined
to a particular branch of engineering. Over 200
students attend this one-semester, three-hour-a-
week course and in 1965, 1966, and 1967 these
sophomores have been divided into: an honors
section of 30.; a large section of 90; and three or
four additional sections of 30. In addition, one
or two evening-school sections of 20 are handled
concurrently. The course is administered by a
Course Chairman appointed by the Dean of
Engineering and Science. Each section is taught
by a single instructor who. handles all student
contact for his section. All involved faculty-
typically 2 chemical, 1 civil, 2 mechanical, and 1
metallurgy-meet at least once a week for about
one hour. It is at these weekly sessions that all
decisions on course content, home problems, tests,
grades, etc., are reached.

Two years before this common course was
initiated the course content was discussed exten-
sively. In general there was surprisingly close
agreement on content. To satisfy the common re-
quirements of the Chemical, Civil, Electrical, Me-
chanical, and Metallurgy Departments, a tradi-
tional macroscopic-oriented approach was selec-
ted, thus de-emphasizing information theory and
statistical aspects.
Although this general approach has remained
fixed, course content has been discussed frequently
by the committee of involved faculty. At the start
of each year, the Course Chairman proposes a
general outline of topics with suggested times.
This outline was never "rubber-stamped" by the
committee; on the contrary, it was always criti-
cized in detail and modified. In general, mechani-
cal engineers argued for greater emphasis on the
concepts of availability, irreversibility and dis-
sipation, while chemical engineers desired more
coverage for heat effects and reaction, estimation
of properties, and reduced correlations. Eventu-

WINTER, 1968

ally a satisfactory compromise was reached and
Table I presents the final version of the 1967
As soon as all faculty have been assigned to
this common course, the Course Chairman calls
a committee meeting to assign class sections to
the individual faculty and to select a text. The
latter problem always presented difficulties and
three different texts have been used in three years.
In 1965 Sears's text' was used. This book was se-
lected because:
1. It represented a general approach and was
not "denominational."
2. It presented a classical, macroscopic view-
3. It was readily adaptable to a one-semester
Sears's text suffered from three drawbacks:
1. Engineering aspects were not emphasized.
2. Students experienced great difficulty in
converting from the metric system of
units to the engineering system.
3. No thermodynamic property data were in-

General Outline of Topics
Tentative Schedule



Introduction, Temperature, and Thermometry

2 Thermo Properties, and Work
1st Hour Test
5 Heat, First Law and Consequences U, H, Cp, Cv;
isothermal and adiabatic processes; energy equa-
tion for steady-state flow; change of phase, P-T,
P-V, In P-H diagrams; heat of reaction
2nd Hour Test
4 Second Law and Entropy
efficiencies of reversible engines
absolute temperature
Clausius inequality
T as an integrating factor
principle of increase in entropy
3rd Hour Test
4 Combined First and Second Laws
availability and irreversibility
Maxwell relations
computation of properties
law of corresponding states
reduced property charts
Make-up Test
Final Examination

The lack of thermodynamic data was compensa-
ted for, at least partially, by handout material
much of which has now been published.2
In 1966 the committee adopted an engineering
text by Van Wylen and Sonntag.3 This text pro-
vided sufficient coverage of all fundamentals and
applications but students complained that some
topics were covered at great length and this made
the text difficult to read. Accordingly, in 1967
another engineering text by Zemansky and Van
Ness4 was used. This book was supplemented by
the student edition of Canjar and Manning's data
book." Zemansky and Van Ness proved to be easi-
ly read by the students but the coverage of some
topics was a little scanty.

A major undertaking for the Course Chair-
man is to ensure that the different sections of
this common course are kept reasonably together
while permitting individual faculty a satisfactory
degree of autonomy. This was accomplished as
follows. The Course Chairman proposed a de-
tailed outline for each major section of the course
(as listed in Table I). As is shown in Table II,
the coverage of "First Law" is described by:
1. referring to appropriate passages in sev-
eral outstanding texts,
2. enumerating the highlights,
3. listing the topics for the homework prob-
These detailed outlines received the same
careful discussion and modification as did the
general outline. Faculty autonomy was realized
because the individual members prepared their
lectures independently and no effort was made to
influence their method of presentation. Of course
whenever "rookie" faculty requested advice on
student reaction to previous years' approaches,
the "veterans" were only too pleased to cooperate.
The individual sections are kept together by
assigning common homework problems at least
90 percent of the time and by giving common
tests. This framework compels the instructor
to follow the accepted schedule of topics reason-
ably closely.
The character of any course is determined by
the nature of the assigned homework, and this
common course derives its uniqueness from the
philosophy of its problems. In fact it is this topic
which has ignited the lengthiest and most fervent
debates. Two philosophies exist. Many instruc-
tors recommend a relatively short type of problem


Detailed Outline of One Topic


First Law and Consequences
(a) Suggested Student Reading


Suggested Course Content

First Law,


February 22-March 24


Pure Substance

Zemansky and Van Ness p. 63-87 p. 235-250 p. 194-224
Van Wylen and Sonntag p. 80-92 honors p. 250-352 p. 48- 54
Keenan p. 8-14 p. 34- 40 p. 44- 57
Smith and van Ness p. 34-40 p. 118-122

(b) Suggested Topics
1. Define heat, First Law in terms of Joule's experiments
2. Internal Energy, enthalpy, and specific heats
3. Isothermal and adiabatic processes
4. Energy equation for steady-state flow
5. Change of Phase, P-T, P-V, In P-H diagrams
6. Heats of Reaction

in which basic principles are isolated and illus-
trated. This "theoretical" type of problem is
frequently characterized by:
1. It illustrates some single principle and/or
2. A major portion consists of a mathematical
3. Simplifications are made with little regard
for actual practice.
4. All required data are usually supplied.
An example is: "Compute the entropy change of
the universe when m gm of water as T1 is adia-
batically mixed with m gm water at T2. Show
that this entropy change is positive."
The second "practical" type problem is de-
signed to acquaint the student with engineering
facts of life as well as illustrate basic principles.
This type of problem is often:
1. Based on an actual industrial process.
2. Is comparatively lengthy in that it usually
involves the interaction of several steps
such as compression, condensation, throt-
tling, etc.,
3. Required data may not be provided.
There is not enough lecture time in this course
to permit detailed descriptions of batteries, fuel
cells, power and refrigeration cycles, etc., so when
these devices are incorporated into this type of
problem the student is advised to read recom-
mended passages in prescribed texts. This prac-
tical type is thus the complete antithesis of the
five-minute, hypothetical type which frequently

(c) Problem Topics
Heat exchanger
Power cycle
Fuel or electrolytic cell
Solar cell
involves the reversible expansion of an ideal gas
in a cylinder fitted with a frictionless piston. Be-
cause these practical problems are used as an in-
troduction to engineering technology, every effort
is made to select numerical values that closely re-
flect actual practice. These problems are pre-
pared as follows: a faculty member elects a topic,
develops a problem, presents it to the committee
where it is discussed, modified, accepted or rejec-
ted. If accepted, he provides fellow members with
a solution-and this solution is not immune to
A notorious example of the practical problem
has been lurking in the Department of Chemical
Engineering for about 20 years, and was first used
by Dr. Robert York. This problem involves the
proposed use of biphenyl in a power cycle (see
Table III). The solution requires construction of
the required T-S diagram using only scanty spe-
cific heat and vapor pressure data. Students must
be given at least one week, and should be en-
couraged to ask probing questions in class before
the problem is due. Now students can outline
solution methods, identify missing links, etc., be-
fore pushing the slide rule. Without such inter-
action, this problem is too difficult for many soph-
omores-few will remember that the Clausius-
Clapeyron equation can yield the missing latent
heats even though it has been mentioned in the
lectures. The instructor must provide enough
help but should not "give away" the problem.
As a compromise, students are given both

WINTER, 1968

Biphenyl Problem
In order to make a power cycle as efficient as possible
in a thermodynamic sense, a double cycle is employed.
The high temperature cycle uses biphenyl (CH,)2 which
absorbs heat by vaporizing at the metallurgical limit of
10000F. The saturated vapor is then expanded through
a turbine to some low pressure. It is then exhausted to
a heat exchanger where it is condensed at 4000F and
thereby boils water which becomes steam for an ordinary
power cycle operating below 4000F. The condensed liquid
biphenyl is then pumped back to "boiler" pressure and re-
peats the cycle.
The properties of biphenyl are:
C, (liq) = 0.320 + 0.001 t BTU/lbOF, t in OF
Cp (sat. vapor at 1 atm) = 1.37 BTU/lb �F
loglo P = 7.9020 - , T in �K; P in mm Hg
(a) What are the pressures in the biphenyl boiler and
(b) Construct the saturated liquid and saturated vapor
curves on a T-S diagram using the data above.
(c) What is the temperature of the exhaust of the bi-
phenyl turbine?
(d) Estimate the ideal work that can be produced by the
biphenyl cycle in BTU/lb.
(e) What is the thermodynamic efficiency of this ideal
cycle ?

types of problems with the emphasis on the prac-
tical type. Test problems are prepared in the
same manner-the problem is submitted, dis-
cussed, modified and approved. Each instructor
grades his own problem for all 200 students, re-
gardless of section. Because the faculty take
turns in proposing and grading hour tests and
the final exam, individual faculty differences in
emphasis of lectures, etc., are averaged out. Final
course grades are assigned as follows. A total
score of each student's performance in all com-
mon hour tests and the final exam is calculated.
The committee examines these scores and on
this basis each section is assigned a quota of A,
B, C, D and fails. The individual instructor now
considers other factors such as homework per-
formance and non-common tests, etc. He is al-
lowed to change individual student grades but his
final result must closely match his assigned quota.
The honors section consists of students having
a B average or better. The instructor is encou-
raged to consider, when possible, additional topics
such as integrating factors for inexact differen-
tials, statistical aspects of the second law, etc.;
however, the common tests and homework prob-
lems keep his section in step with the others. The
honors instructor enjoys his assignment but fac-

ulty assigned to other sections sometimes com-
plain about the poorness of their students. Stu-
dent response to the honors section is noncom-
In general, students dislike the large section
apparently on grounds of previous experience.
Specific complaints, such as no time to ask ques-
tions, can be reduced remarkably by assigning an
excellent teacher. Then some students have even
requested to be transferred to the large section
during the semester. Student performance in the
large section is just as good as other sections ex-
cept, of course, the honors.

To reduce the class time spent on formal lec-
turing, programmed-learning material was sub-
stituted for the lectures on "temperature" in 1966
and for "basic concepts, work, and temperature"
in 1967. These programs5 thus replaced one week
of lectures in 1966 and three weeks in 1967. All
students were expected to have the following
background knowledge:
1. Two semesters of freshman chemistry
2. Three semesters of physics (including a
course on heat)
3. Three semesters of mathematics (including
partial derivatives and line integrals).
Programs were designed to teach the students
relevant basic nomenclature, definitions, and con-
cepts such as system, control volume, process, ex-
act and inexact differential, temperature, work,
etc. A linear programming technique was used
throughout. Direct testing of these programs was
achieved by pre-test and post-test sections incor-
porated into the programs. Students were as-
signed these programs as home assignments. To
facilitate program testing, students were asked to
tabulate their own responses on supplied "score-
cards," which were returned anonymously. Stu-
dents were allowed to keep the programs. Dur-
ing these test periods class discussion of these
topics was avoided. After collection of scorecards,
students were assigned typical homework prob-
lems which were discussed fully a week later.
Student performance in these problems and in
hour test problems on work and temperature was
judged to be at least as good as that exhibited
in other areas where conventional lecture and
problem discussion methods were used.
Table IV summarizes some statistical data
resulting from the scorecards. Notice that a 50-
minute lecture can be replaced by approximately


40 minutes' work of programmed material. Stu-
dent opinion was judged qualitatively. There were
no complaints that they were being "cheated" out
of lecture time. Complimentary comments out-
numbered complaints by a good margin.
These experiments show that factual material
can be taught by carefully prepared programmed
material more efficiently than by lecture. The
programs were confined to "black or white," yes
or no situations such as open or closed systems;
exact or inexact differentials; system or sur-
roundings. No attempt was made to program ma-
terial involving judgment between "different
shades of gray" such as cases when numerical in-
tegration of work expressions is superior to ana-
lytical methods.
Summary of Programmed-Learning Experiments
Program Introduction Work Temperature

approx. lecture
time replaced
average student
Error rate

50 min 50 min 100 min

37 min 36 min

43% 61%
5% 21%

81 min


This common course in thermodynamics offers
the following advantages:
1. Students appreciate the universal impor-
tance of thermodynamics from the start.
2. The traditions and prejudices of individual
departments do not escape unchallenged.
Best aspects and techniques emerge.
3. The participating faculty have a unique
opportunity to widen their outlook.
4. The practical-problem philosophy has been
5. Feasibility of employing large sections has

been demonstrated.
6. Programmed-learning material can con-
serve valuable class time for problem dis-
cussion, etc.
These advantages are not realized without
cost. The Course Chairman's job is most time-
consuming; in particular, the weekly committee
meetings require extensive preparation. The stu-
dents' dislike of large sections can be reduced re-
markably by assigning competent and experienced
Further improvement can be realized by using
films and models. These media would facilitate
student comprehension of engineering devices
such as turbines, etc.-a source of frequent
The authors enjoyed the weekly discussions.
There were differences at first, but the resultant
friction when lubricated with constructive criti-
cism produced a highly burnished product.
The authors thank all faculty who partici-
pated in this common course for their coopera-
tion. Financial support for the preparation of
the programmed-learning material by the
A.S.E.E. through their Programmed-Learning
Project is gratefully acknowledged.
1. F. W. Sears, An Introduction to Thermodynamics,
The Kinetic Theory of Gases, and Statistical Mechanics,
2nd Ed., Addison-Wesley Pub. Co., 1953.
2. L. N. Canjar and F. S. Manning, Thermodynamic
Properties and Reduced Correlations for Gases, Gulf Pub.
Co., 1967. (Student edition.)
3. G. J. Van Wylen and R. E. Sonntag, Fundamen-
tals of Classical Thermodynamics, J. Wiley and Sons, 1965.
4. M. W. Zemansky and H. C. Van Ness, Basic Engi-
neering Thermodynamics, McGraw-Hill Book Co., 1966.
5. F. S. Manning, Introduction to Thermodynamics;
Temperature; and Work, Programmed Learning Texts,
Carnegie Institute of Technology 1966-67.

Dr. Manning received a B. Eng. (Hons.) from McGill Uni-
versity and M.S., M.A., and Ph.D. from Princeton. Since 1959
he has been at Carnegie-Mellon University where he is now
Associate Professor of Chemical Engineering. Dr. Manning's
research interests include correlation and estimation of thermo-
dynamic properties, mixing and reaction in stirred vessels, and
kinetics of metallurgical reactions and urea-hydrocarbon ad-
dution. (Photo at right.)

Dr. Lawrence N. Canjar has been the Chrysler Professor
and Dean of Engineering at the University of Detroit since
1965. He was educated at the Carnegie Institute of Technology
(BS '47, MS '48 and DSc '51) and joined the staff as instructor
in 1950. In 1961, he became Associate Dean of the College of
Engineering and Science. (Photo at left.)

WINTER, 1968


Providing Meaningful

Laboratory Experience for

Undergraduate Students

in Transport Phenomena

Department of Chemical Engineering
The University of Texas at Austin
Austin, Texas, 78712

Stated rather broadly, the objective of an
undergraduate course in transport phenomena is
to help students develop an understanding of, and
the ability to apply, those concepts and prin-
ciples which are involved in the transport of mass,
momentum, and energy. Included among the con-
cepts are the notions of velocity, stress, rate of
strain, viscosity, thermal flux, temperature grad-
ient, thermal conductivity, heat generation rate,
mass flux, concentration gradient, diffusivity, and
others. The principles are six in number: con-
servation of mass, momentum, and energy; Fick's
law of diffusion; Newton's law of viscosity, and
Fourier's law of thermal conduction. Since the
ideas of transport phenomena are basic to many
of the methods employed by chemical engineers, it
is appropriate that we should exploit whatever
techniques are available to accomplish our objec-
Probably without exception, the stimulus on
which primary reliance is placed is the profes-
sor's lecture. In most courses, reading assign-
ments are made from one of the standard text-
books, and homework problems are assigned to
help the student gain facility in applying the
principles. A conscientious professor may em-
ploy some of the film strips or short movies which
are now available, and he may even present a
demonstration or two. All of these are certainly
valid instructional techniques, but they can be
richly complemented by experience gained in a
well-designed laboratory. The purpose of this
paper is to describe our attempt to provide such
experience for students at the junior level.

We have devised a set of experiments, each
of which has to satisfy the following criteria be-
fore being accepted for inclusion in the labora-
1. It has to accomplish certain clearly stated
2. It has to be capable of producing experi-
mental data which are in reasonable, say �10
percent, agreement with theoretical predictions.
3. It has to be relatively free of extraneous
4. The equipment has to be relatively inex-
pensive to obtain and easy to maintain.
The methods that we have used to meet these
criteria can be presented most easily by describ-
ing the first experiment.
This experiment takes two weeks to complete,
although much of the first laboratory period is
devoted to administrative and operational details.
It concerns laminar flow in circular tubes, and its
objectives are stated as follows:
1. To enable the student to visualize the velo-
city field for flow through a circular tube.
2. To generate some confidence in the correct-
ness of the theory of Newtonian fluid mechanics
in general and in the Hagen-Poiseuille equation in
3. To develop an appreciation for the two
externally applied forces to which fluids are
normally subjected in tubes. These are a longi-
tudinal pressure gradient and the force of gravity.
4. To illustrate an important limitation which
must be applied to any theoretical analysis based
on laminar flow. This is the transition from
laminar to turbulent flow which occurs when the
velocity exceeds a critical value.
5. To illustrate the use of a manometer to
measure pressure in a fluid.
The principal piece of equipment used in this
experiment is a constant head tank. It will be


described in more detail later, but now it will
suffice to mention that the outlet fitting can ac-
cept either a piece of 14 mm glass tubing, which
projects up into the tank, or any other piece of
equipment which terminates in 1/2 in.-OD tubing.
In the second part of this experiment we attach a
piece of 3/16 in.-OD aluminum tubing to the out-
let fitting. The connection is made through a re-
ducer and a short piece of plastic tubing which
permits the angle of inclination of the 3/16 in.
tubing to be changed during the experiment. The
tube is fitted with pressure taps near the inlet
and outlet ends. Manometer tubes which are open
to the atmosphere are used to measure the pres-
The experiment is performed in two parts.
In the first part, which is the well-known Rey-
nolds experiment, the students observe flow
through a vertical section of 14 mm glass tubing.
A piece of capillary tubing is used to inject a
dye filament into the stream near the center of
the larger tube. The flow rate can be adjusted
with a valve located at the discharge end of
the tube. It is possible for the students to
observe that the flow is laminar at low veloci-
ties and becomes turbulent at higher velocities.
The velocities are low enough that they can
be measured with a graduated cylinder and a stop-
watch. When a large blob of dye is injected into
the stream, the students can see it deform into
a well-defined parabola as it progresses down
the tube. Again the velocity of the leading edge
of the colored fluid is low enough that it can be
measured accurately with a stopwatch and a
meter stick. Hence, the student readily confirms
that the centerline velocity is twice the average
velocity. It is also worth mentioning that this
is an aesthetically pleasing experiment; the stu-
dents enjoy the experiment, and it gets the
laboratory off to a good start.
In the second part of the experiment, the glass
tube is replaced by the 3/16 in. tube, and the
manometer levels are measured at various angles
of inclination and flow rates. A removable valve
at the discharge end of the tube permits the flow
rate and the angle of inclination to be varied
independently. In analyzing their data, the stu-
dents are asked to make two graphs: volumetric
flow rate with the valve removed versus dif-
ference in elevation between the liquid level in
the reservoir and the discharge end of the tube,
and difference in manometer levels versus flow
rate. If the flow is laminar and one can neglect
all frictional losses except those in the tube, the
WINTER, 1968

first graph should be a straight line with a slope
of 7rR4pg/8[L. Actually, the resistance of th3
inlet fitting is not completely negligible, and the
measured slope is slightly smaller than the theo-
retical value. Since he can see from the mano-
meter reading that the pressure at the inlet end
of the tube falls as the flow rate increases, the
student readily arrives at the correct explana-
tion for the discrepancy. The second graph is
quite free from spurious effects, and the experi-
mental data agree well with the theoretical curve.
It should be noted that the difference in mano-
meter levels is equal to the pressure drop due
to viscous losses; the gravitational force exerted
on the fluid in the tube is balanced by the extra
gravitational force exerted on the fluid in the
manometer line leading to the upper pressure tap.
Providing a proper explanation for this phe-
nomenon forces the student to think clearly about
the various forces which act on a fluid in a tube.
This experiment was designed so that the
flow would be laminar over most of the accessible
range of velocities. At the higher flow rates, the
critical Reynolds number is exceeded, which can
be seen clearly by the student because the flow
tends to become unsteady in the transition region.
His graphs also tend to deviate from the theo-
retical curves at the transition point. He is asked
to calculate the Reynolds number at the transition
point, and values in the range from 2100 to 2500
are usually obtained. Furthermore, his experience
in the first part of the experiment prepares him to
accept the notion of an eddy diffusivity and an
eddy viscosity, both of which greatly exceed the
corresponding molecular values. Hence, he can
predict qualitatively how his experimental data in
the turbulent region should deviate from the theo-
retical curves for laminar flow.
We feel that this simple experiment illustrates
many ideas that are fundamental to hydrody-
namics. Since the same ideas are presented in
the classroom, one can ask, "Why go to the trouble
of setting up a laboratory in which experiments
such as this can be performed?" The answer to
this question, in our opinion, is that percepts
gained through laboratory experience tend to be
more vivid and lasting than those gained in the
classroom. Furthermore, a higher level of prob-
lem solving is involved in analyzing experimental
data than in solving most textbook problems. The
student has to devise the problem that pertains
to his particular experiment before he can solve
it. He has to recognize what is important and
what can be neglected. And finally, he profits by

his own mistakes if he is persistent enough to
bring the experimental and theoretical results
into agreement. We have found that the last point
is very important, but it can only be realized if
the experiment is designed in such a way that
accurate data can be obtained.
If a laboratory such as this is to complement
the lecture course, timing is important and all of
the students must be doing the same experiment
at the same time. Adequate access to the equip-
ment can be achieved only if the students work
in groups of two or three. This means that as
many as ten complete sets of equipment may be
required at a large university. We have tried to
make this possible by designing small pieces of
apparatus, individual parts of which can serve
many purposes.
For example, the constant head tank men-
tioned earlier was made from a three liter stain-
less steel beaker. Two holes were cut in the
bottom of the beaker. An overflow pipe was
soldered into one of the holes, and a one-half
inch bulkhead fitting of the Swagelok type was
fastened into the other hole. An O-ring groove,
cut into the inside surface of the bulkhead fitting,
permits a water tight seal to be maintained
around the piece of 14- mm glass tubing which
passes through the fitting. Of course, any other
piece of equipment terminating in one-half tub-
ing can also be attached to the fitting. This fea-
ture enables us to use the constant head tank in
five distinct experiments.
The second hydrodynamics experiment is a
tank-emptying experiment for which it is only
necessary to turn off the inlet flow line. In the
third experiment, the behavior of a siphon is
studied, and the constant head tank is used again
as a reservoir. We also do a heat transfer ex-
periment in which transient heating and cooling
of the contents of the tank are studied. Although
the details have not been completely worked out,
we also plan to devise a transient state mass
transfer experiment.
In the case of the heating experiment, the
heater is a small finned-tube heat exchanger,
which passes through the Swagelok fitting in the
bottom of the tank, and is sealed by the O-ring.
The lower end of the heater fastens directly onto
a small electrically heated boiler that can provide
over a kilowatt of power. The boiler also serves
several purposes. In addition to providing steam
for the tank heating experiment, it provides
steam for a thermal conductivity cell in which

heat transfer through composite slabs is studied.
It also provides steam for the annular region of
a small concentric tube heat exchanger.
By reducing the size of our equipment,
keeping it relatively simple, and making the more
expensive pieces perform multiple functions, we
have been able to obtain the necessary equipment
with a rather modest capital outlay. It is also
worth noting that, since the equipment is small
in size, finding adequate storage space is not a
The experiments are performed in one bay
of a large laboratory. This bay has been fitted
with a number of "distillation racks." Electrical
power, water, air, and drains are provided at
each of the racks. The equipment can be mounted
easily on a rack and left there for several days if
necessary. This permits the students to come back
and repeat part of an experiment or obtain ad-
ditional data. Hence, they are not as pressed for
time as they might otherwise be, and they can
be held responsible for the accuracy of their ob-
In this brief paper an attempt has been made
to describe the approach that we have used to
provide meaningful laboratory experience for an
undergraduate class in transport phenomena. A
considerable amount of effort has already gone
into this project, and more will be required before
a really satisfactory result is achieved. Hopefully,
others can benefit from our experience as we have
benefitted from the experience of those who pre-
ceded us.
Acknowledgement. It is a pleasure to ac-
knowledge the contributions made to this project
by three of the author's colleagues, K. B. Bischoff,
N. F. Brockmeier, and R. S. Schechter.

Dr. Eugene H. Wissler is a Professor of Chemical
Engineering at the University of Texas in Austin. He
received a B.S. degree from Iowa State College in 1950
and a Ph.D. degree from the University of Minnesota in
1955. After spending two years at the Army Medical
Research Laboratory, he joined the faculty at Texas in
1957. His research interests include heat transfer in the
human, rheology, and aerosol physics. In May, 1967, he
was awarded the $1400 General Dynamics Award for Ex-
cellence in Engineering Teaching.



"It is more important

to carryon research

than itisto pay

i -dividends." The speaker was
* . Lammot du Pont. The year was gloomy 1932, and he was
president of Du Pont. A proposal had been made to pare
' the research budgets in order to protect the dividend.
As it turned out, the company was strong enough to
pay for both, and it hasn't missed paying for either in the
past sixty years. But there was no doubt which way Lammot
du Pont would have decided back in 1932. And today, we
invest more than $100 million a year in the quest for new
knowledge and better products.
It is precisely this attitude towards research and
development that attracts so many graduates every year.
And that makes Du Pont such an exciting and rewarding
place to work.
There is no formal training period. Our men go into
responsible jobs from the first day.
They work in small groups where individual contribu-
tions are promptly recognized and rewarded. Promotions
come from within the company.
They do significant work of positive benefit to society.
And they work with the best men in their fields in a crackling
technical environment that provides every facility needed.
If our attitude towards research and work agrees with
yours, why not suggest that your students sign up for a talk
with a Du Pont recruiter? Or that they write our College
Relations Manager, Wilmington, Delaware 19898, for
additional information on opportunities in their fields.


WINTER, 1968

Mass Transport Phenomena In

The Human Circulatory System*

Assistant Professor
Department of Chemical Engineering
University of Minnesota
Minneapolis, Minnesota

The value of biological research in a
chemical engineering graduate program is
discussed by taking examples from the
mass transport phenomena occurring in
the human circulatory system. The parti-
cular points stressed are the broad range
The programs for meetings held over the past
few years by the American Institute of Chemical
Engineers and the American Society for Engi-
neering Education bear witness to the emergence
and persistent growth of interest in the inter-
action of engineering and biology. Almost every
meeting has had at least one session devoted to
some aspect of this interaction.
There are many possible explanations for such
a development, all of them probably true to some
extent. In the last decade, advances in the bio-
logical sciences have been the most dramatic in
the scientific world and have called particular at-
tention to the field. Morover, the social and hu-
manistic awareness which seems to characterize
the 1960's suggests that many people may find
greater satisfaction in problems whose solutions
appear to them to contribute directly to human
welfare. Finally, the recognition and develop-
ment of new kinds of unifying principles in chemi-
cal engineering, such as the transport phenomena,
have greatly increased the range of applicability
of chemical engineering techniques and perhaps
have stimulated many of us to attempt to prove
their usefulness in the unfamiliar and challenging
areas of biology.
However, speculating on the reasons for the
growth of biological engineering, while interest-
ing, is not my purpose in this discussion. In keep-
ing with the subject of the meeting, it would
seem more appropriate to consider what effect
this new area can or should have on graduate
chemical engineering research. It is necessary to
recognize that there are two extremes of organi-

*Presented at the Annual Meeting of ASEE, June
19-22, 1967.

of such problems from molecular diffu-
sion to artificial organ design, the rele-
vance of the problems to traditional areas
of engineering concern, and the value of
research in the area as a technique for
training engineering students.


Right subclavian

Middle suprarenal

Common iliac
Internal iliac

Fig. 1.-Human circulatory system.
From Chaffee and Greisheimer, Basic Physiology and
Anatomy, with permission of J. B. Lippincott Co.,


Dr. Keller did his undergraduate work at Columbia University and then spent four
years in the Navy assigned to the Atomic Energy Commission. In 1959 and 1960,
while in the Navy and attending the Johns Hopkins University part time, his interest
in biologically-oriented problems developed. His full-time graduate research began
in 1961 at Hopkins, centered on the phenomenon of augmented oxygen diffusion in
hemoglobin solution. Since 1964 he has been an Assistant Professor of Chemical
Engineering at the University of Minnesota and has continued and expanded his
research interests in transport processes in biological systems. He is now directing
research in diverse problems from protein diffusion studies to blood oxygenator design.

zation between which most bioengineering pro-
grams lie: the independent, formal bioengineer-
ing program, functioning through an interdis-
ciplinary group joined together by a common
interest in biology and the informal group whose
research and teaching simply constitute one spe-
cial area of a chemical engineering department.
There is certainly no unanimity among people
working in the field as to which, if either, of these
extremes is the better for effective biological re-
search, but obviously only the latter arrangement
can benefit a chemical engineering department
directly. Therefore my remarks will relate to
this latter arrangement. In particular, I would
like to illustrate:
a. The relevance of biological problems to the
traditional areas of chemical engineering con-
b. The wide range of problems in biology to
which engineering analysis can be applied effec-
c. The mutual benefit to biology and engi-
neering which can result when engineers attack
such problems.
d. The didactic value of having graduate stu-
dents work in the biological area.
These points are best illustrated by example
and the human circulatory system is a conve-
nient one.* For many purposes the human body
can be considered to be a highly complex chemi-
cal plant utilizing the energy of combustion to
synthesize biological materials and to do work.
The sites of reaction are distributed throughout
the body and the circulatory system serves to
deliver the reactants and remove the waste
products; since the body functions isothermally,
*A useful and interesting introduction to the circula-
tory system is provided by Alan Burton's recent mono-

it must also remove excess heat. In addition the
system serves a host of secondary functions:
maintaining the proper water and salt content,
distributing drugs and natural antitoxins, main-
taining its own integrity by sealing "holes," ad-
justing pH to an optimal level, etc.
The magnitude of the job which the circula-
tory system must perform is evident from its
design parameters. There are 5 to 6 liters of
blood in the average human being (wholly con-
tained within the circulatory system). The sys-
tem's pump, the heart, has a capacity of about
6 liters/minute so that the circulation time
through the body is slightly less than 1 minute.
The average adult (70 kg) consumes about 14
liters (STP)/hr of 0s and releases about the same
amount of CO2, all of which is transported
through the circulatory system.
The form of the system, as usually depicted
in a medical text, is shown in Figure 1. Its most
obvious characteristic is its high degree of
branching, with main vessels branching in steps
to large numbers of smaller vessels. However,
from the point of view of mass transport, it is
equally important to note that the system is
bounded and that transfer into and out of the
organs and tissues of the body must occur across
the walls of the circulatory system. Such trans-
fer takes place almost entirely in that region of
the system made up of a network, or bed, of
thin-walled, narrow bore tubes called capillaries.
These capillaries are 10p in diameter, have a wall
thickness of about 1l and a length of about 1
mm. Capillary beds are found in every organ and
tissue of the body; since they are too small to be
distinguished individually by the naked eye, it
often appears that the blood is dispersed in a dif-
fuse, continuous distribution through the tissue.
There are about 109 capillaries in the body so

WINTER, 1968

A B ,C ,D E

Fig. 2.-Schematic flow path to and from a single
capillary bed. A. Artery; B, Arterioles; C, Capillaries;
D, Venules; E, Vein.
that, despite the small size of each one, the total
surface area available for transfer is about 340
ft'. The extremely high surface to volume ratio
in the system is evident from the fact that even
with this large surface area, the capillaries con-
tain less than a liter of blood at any instant.
Transfer is so efficient that the residence time of
blood in any capillary bed is only about 1 second.
The capillary beds are local structures and
the rest of the circulatory system can be thought
of as the piping to connect these structures and
to carry materials and heat from one part of the
body to another. The branching and progressive
decrease in diameter of the system's piping is
necessary to connect the central, large branches
and the distributed, small branches. In Figure 2,
one complete network is shown. Blood flows from
the heart through the main artery (about 1" in
diameter), branching to smaller terminal arter-
ies, still smaller arterioles, and finally to capil-
laries. After exchange has taken place in the capil-
laries, the blood flows to larger venules, still
larger veins, and finally to the principal veins of
the body which lead back to the heart.
One of the key steps in defining engineering
problems in a biological system is that of trans-
lating the description of the system into engi-
neering terms. Consider, for example, how the
schematic diagram of the circulatory system
could be redrawn to the more familiar sort of
schematic shown in Figure 3. The system is de-
picted as simply a set of single-pass shell (tissue)
and tube (capillary) mass and heat exchangers
connected in parallel. The arterioles and venules
are the headers and the small arteries and veins
are the connections to the main pipes. Pumping
is provided by a double reciprocating pump and
is, therefore, pulsatile. 0, enters the system and
CO2 leaves the system in the exchanger called
the lungs. Water, salt, and waste are removed
through the exchanger called the kidney. On the
shell side of the other exchangers, various chemi-

cal reactions take place which consume oxygen
and produce carbon dioxide (muscles, brain,
etc.). Heat is rejected from the body in the capil-
lary beds, or exchangers, located in the vicinity
of the outer surface of the body. Note that the
heart and lungs are the only two organs through
which all of the blood passes on each circuit.
The actual mass transport and transfer tak-
ing place in each of these units is not, of course,
as simple as this picture would suggest. How-
ever, it does illustrate the transfer functions in-
volved and thereby provides a basis for analyzing
the behavior of each organ. It also establishes
the functional requirements of any replacement
or prosthetic unit, the design of which is one of
the important areas of biological engineering.
If we proceed further and examine some of
the transport and transfer processes in more de-
tail, the efficiency and complexity of the circula-
tory system become evident as well as the range
of challenging research problems to which
chemical engineers have applied and should apply
Consider, for example, the process of oxygen
transfer in the lungs. The blood, depleted of oxy-


Right - Coled ______ Left
heart heort

Liver s leen- Small intestine

Large intestine


Lower extremity
Fig. 3.-Schematic diagram of circulatory system.


gen by the tissues, enters the lung capillary bed
at an oxygen tension* of about 60 mm Hg. It
takes up oxygen and leaves the lungs at a tension
of about 100 mm Hg. If oxygen uptake by the
blood were limited to that which could be physi-
cally dissolved, a simple mass balance could be
written to calculate the blood flow rate necessary
to absorb the 14 liters (STP)/hr needed by the
body for metabolism, i.e.

14 liters (STP)
60 min

The concentrations can be calculated approxi-
mately from the physical solubility of oxygen in
water (0.024 liters (STP)/liter HO2 atm). This
equation can then be solved for Q, the volumetric
flow rate, yielding a value of 185 liters/min, 31
times the actual flow rate available. Thus the
circulatory system must have recourse to some-
thing other than the simple physical solubility
of oxygen in order to absorb a sufficient amount
of oxygen. This is provided for in blood by the
large protein molecule, hemoglobin, which can
combine reversibly with four oxygen molecules.
Hemoglobin is present in blood to the extent of
15 gms/100 ml and, based on its molecular weight
(68,000), if it is completely oxygenated, approxi-
mately 50 times as much oxygen can be carried
in this combined form as is carried in the physi-
cally dissolved form. The combination must, of
course, be reversible in order for the oxygen to
be available to the tissues for metabolism. In
*Oxygen tension, in physiological parlance, is that
concentration of oxygen in liquid which is in equilibrium
with a gas phase having an oxygen partial pressure of
the value stated.

o 80

. <
Z. 40-
o -
I: r

P02, mm Hg
Fig. 4.-Typical equilibrium curves.

Q[(CO,)out - (CO),i] =

WINTER, 1968

capillary wall

alveolar sac
(gas phase)

plasma red blood cell-
Fig. 5.-Red blood cells passing through a capillary.

fact, the equilibrium between hemoglobin and
oxygen is not only reversible, but shifts conven-
iently to facilitate absorption and desorption.
This is illustrated in Figure 4, which shows some
typical oxygen-hemoglobin equilibrium curves.
Note that at low CO2 concentrations (which
would exist in the lungs), the affinity of hemo-
globin for oxygen is large and the hemoglobin
is close to fully oxygenated at an oxygen tension
of 100 mm Hg. However, at high CO, concentra-
tions, such as those which are found in the body
tissues, the affinity decreases and the degree of
oxygenation for a given oxygen tension decreases
markedly so that oxygen is readily available to
the tissues.
Hemoglobin is not distributed homogeneously
throughout the blood; it is contained in extremely
high mass concentration (35 gms/100 ml)
within the red blood cells which constitute 40-45
percent by volume of the blood. These red blood
cells are biconcave discs approximately 8/A in
diameter and varying from 1/, to 2.5[ in thick-
ness. Thus, their diameter is almost equal to the
inside diameter of the capillaries. In fact, in
passing through the capillaries, the red blood
cells line up in single file and slip through as
shown in Figure 5. For the capillaries of the
lung, note the complex diffusional process in-
volved in getting oxygen from the gas sacs of the
lung alveolii) to the hemoglobin with which it
must react. The oxygen must diffuse across the
capillary wall, through a layer of plasma, across
the red blood cell membrane, and then through
the hemoglobin solution with which it simul-
taneously reacts. This gives rise to several in-
teresting and not completely solved mass trans-
fer problems. For example, which of these re-
sistances is limiting on the total rate of uptake
(or desorption) of oxygen? What path does the
oxygen take in the plasma? Do the convective

For many purposes the human body can be
considered to be a highly complex chemical
plant utilizing the energy of combustion to
synthesize biological materials and to do

mixing patterns which must be set up in the
plasma between cells increase the uptake rate?
Is the red blood cell membrane equally permeable
over its entire surface or do materials cross it in
localized regions? What bearing, if any, does the
shape of the cell have on mass transport?
The answers to such questions have an ob-
vious bearing on the design of devices to replace
inoperative transfer organs in the body. They
may also be useful in the diagnosis of pathologi-
cal (disease) conditions. But one of the impor-
tant lessons in the development of engineering
has been the recognition that it is possible to
generalize results, to see the phenomenological
similarities between processes in quite different
systems and to relate the experimental and ana-
lytical results of one system to another. Thus,
the results of studies of mass transfer across the
membrane of a red blood cell should bear some
relation to the problems of supplying nutrients
to microbial cultures. They should also comple-
ment the work of cell physiologists studying gen-
eral membrane properties. Similarly, informa-
tion on diffusional behavior in hemoglobin is of
interest to molecular biologists and biophysicists
interested in characterizing macromolecules.
Therefore I think it is necessary to avoid the nar-
row interpretation that biological engineering re-
fers to clinically directed, biomedical problems. I
have, in fact, avoided the use of the term "bio-
medical engineering" for precisely this reason.
A reasonable approach to understanding the
uptake of oxygen in blood is to study separately
each of the diffusion resistances involved. The
easiest of these to study is the red blood cell
(contents and membrane) since it can be easily
removed and studied outside the body, or in vitro.
Much of the early work in this area was done by
F. J. W. Roughton who published a useful review
article some years ago.2
In the cell itself, the transport process occur-
ring is one of diffusion accompanied by reversible
chemical reaction. In this context, it is analogous
to such industrial processes as the absorption of
chlorine by water which has been studied exten-
sively by Vivien and Brian.3 Therefore this is a

typical problem in which the results of studies
on the biologically important system have appli-
cability to traditional engineering systems. Be-
cause the hemoglobin-oxygen reaction is accom-
panied by an easily detectable color change, it
provides a simple experimental system and we
are now using it to study unsteady gas absorp-
tion with reaction.
Studies on the hemoglobin-oxygen system
have uncovered another mass transport phe-
nomenon of engineering interest. In 1959 and
1960, Wittenberg4 and Scholander5 discovered
that if a Millipore filter soaked in hemoglobin
solution were placed between two gas chambers
at different pressures, the steady-state diffusion
of oxygen exceeded that of nitrogen by several-
fold in certain concentration ranges although
their driving forces were the same. This intrigu-
ing phenomenon has been studied in some detail
by several workers, including Friedlander and
myself6'7 and the mechanism is fairly clear. Oxy-
gen entering the liquid phase will combine re-
versibly with hemoglobin. Because of the equi-
librium between combined and uncombined form,
the concentration of oxygenated, or oxyhemoglo-
bin, will depend upon the local concentration of
oxygen. Since an oxygen gradient exists across
the system, in certain ranges of concentration
an oxyhemoglobin gradient will also exist and
the total flux of oxygen will be the sum of the
two resulting fluxes. The interesting engineer-

It is necessary to avoid the narrow
interpretation that biological engineering
refers to clinically directed, biomedical
problems. I have, in fact, avoided the use
of the term "biomedical engineering" for
precisely this reason.

ing aspect of this is that such a system can be
used effectively to separate gases if a reversibly
reacting species can be found which reacts se-
lectively with one of the gases. At General Elec-
tric, Ward has been examining such separation
In the course of our investigations into this
phenomenon, it was necessary to determine the
diffusion coefficient of hemoglobin as a function
of concentration. The subject of diffusion of
large molecules in liquids at other than infinite
dilution is one for which there are relatively
few data and no useful theory. Yet, almost all


3- 7


Fig. 6.-Diaphragm cell for methemoglobin diffusi
coefficient measurements: 1,Stirrer; 2, Upper compal
ment; 3, Teflon gaskets; 4, Millipore filter; 5, Sample inle
6, Magnetic stirring bar; 7, Lower compartment.
living cells contain at least 20 percent by volun
of large protein molecules, so that such data a
necessary if intracellular diffusion problems a
to be examined. We have developed a modifi
Stokes diaphragm diffusion cell which allov
rapid measurement of protein diffusion coef
clients . In the cell, shown in Figure 6, diffusic
takes place only in the thin, Millipore filter sep
rating the two reservoirs. Because the filter
thin, steady state is achieved rapidly and diff
sion fluxes are large enough to be measure
despite the large size and correspondingly sma
diffusion coefficients of protein molecules. O
feature of proteins which makes them desirab
for such studies is the fact that radioacti
tracers can be attached to them easily, there
facilitating tracer diffusion measurements. Th
obviates the need for converting integral diff
sion coefficients to differential diffusion coef
clients, a process which has inherent inaccur
Some of our results with hemoglobin are plo
ted in Figure 7. It is interesting to note that
high concentrations, the diffusion coefficient d
creases linearly with concentration. Other ava

able data indicate similar behavior and have led
us to a simple phenomenological theory for pre-
dicting diffusivities of proteins as a function of
concentration. A question not yet investigated,
but of great interest, is whether or not, as a re-
sult of the small size of the cell, proteins exist
in vivo as liquid crystals with markedly different
diffusional properties.
The membrane which forms the boundary of
the red blood cell represents a separate area of
investigation. Electron micrography has shown
that the membrane is about 100 A thick and
composed of protein and lipid (fat-soluble) mate-
rial. While there is still basis for argument, the
so-called unit membrane shown in Figure 8 is
often accepted as representative of the membrane
structure. It is simply a bimolecular lipid film,
oriented with polar ends outward toward the
aqueous phases and non-polar ends inward, and
5 sandwiched between protein layers. While the
picture fits morphological evidence, it is of little
help in understanding or choosing a model for
explaining the transfer function. For example,
should the membrane be modeled as a matrix of
on pores in an otherwise impermeable structure?
rt- This might explain a selective permeability based
et; on the size of the diffusing molecule. On the
other hand, if the membrane were modeled as a
ne continuous, non-polar phase, selectivity would
re result from variations in phase partition coeffi-
re clients among different molecules. Indeed, both
ed kinds of selectivity occur and suggest that a more
s complex description is necessary to understand
fi- membrane function adequately.
on Perhaps the most intriguing aspect of mem-
a- brane transport is suggested by the observed
is distribution of nationss inside and outside the red



PDtb-t S


e l

1 2 3 4 5 6 T 8 9 1o Ro 30 40 0O
Methemocobin Concentrtion ( to/om )
Fig. 7.-Diffusion coefficient of methemoglobin at 250C.

WINTER, 1968


blood cell. Inside the cell, the concentration of
K+ is 0.136 M while that of Na+ is only 0.019 M.
Outside the cell, the situation is reversed with
the K+ concentration only 0.005 M and the Na+
concentration 0.112 M. Yet tracer studies show
that both cations exchange across the membrane
and, moreover, if an excess of K+ is placed in
the plasma, it is quickly taken in by the cell. The
flux is thus in the opposite direction from that
expected by simple diffusion theory. Close inves-
tigation shows that this flux is accompanied by
chemical reaction in the membrane which pro-
vides the energy necessary to satisfy thermo-
dynamic considerations. However, we are still
far from understanding the mechanisms of this
"active transport." A good deal of effort has
been spent in describing the phenomenon in the
formalism of irreversible thermo-dynamics," but
this simply begs the question. Since membranes
are now thought to be responsible for most of
the organizing and control functions of biological
systems, research in this area is of great current
Still another kind of mass transport exhibited
by the circulatory system is that resulting from
the flow patterns in the larger vessels. Through-
out most of the circulatory system, the Rey-
nolds' number is less than its critical value and
flow is laminar. The laminar velocity profile is
essentially parabolic, although somewhat flat-
tened at the center because of the pulsatile and
non-Newtonian character of blood flow. Nor-
mally in laminar tube flow, radial diffusion occurs
only through Brownian motion. Blood, however,
is particulate in nature and the red blood cells
rotate as they flow under the influence of the
velocity gradient. As they rotate they stir the
plasma in their vicinity and thereby cause a mix-
ing motion which can be interpreted as a particle-
induced eddy diffusivity. This phenomenon should
augment the radial transport of species dis-
solved in the plasma and, indeed, preliminary
experiments indicate that it does.12 We are now
utilizing the effect to decrease the resistance of
the plasma to diffusion in an artificial blood oxy-
genator. We hope that this will allow us to de-
crease the required surface-to-volume ratio of the
oxygenator, an important design improvement.
There is also evidence that the phenomenon may
aid in understanding some of the transport me-
chanisms involved in arteriosclerosis. Finally, it
seems possible that this phenomenon can be put
to use in certain industrial processes. For ex-


70 A

Fig. 8.-Unit membrane structure.
Fig. 8.-Unit membrane structure.




ample, if a diffusion limited wall-catalyzed reac-
tion takes place in a continuous flow tubular
reactor, it may be possible to increase its effic-
iency by introducing a suspension of inert par-
ticles to decrease diffusion resistance.
I have avoided a direct discussion of the de-
sign of artificial organs not because it is less
important than these others, but because it is
perhaps the most obvious area for engineering
participation in biomedical research. It is, of
course, profoundly important, and has given rise
to many interesting problems in trying to dupli-
cate the efficient transfer processes of the body
and in trying to find materials compatible with
blood. A review of the early design work in
heart-lung assists is given by Galletti and
Brecher" and a running account of the current
state of things is available in the Transactions
of the American Society for Artificial Internal
So much then for this cursory look at the
range of mass transfer problems in the circula-
tory system. It is, I think, clear that these prob-
lems are the legitimate concern of chemical
engineers. I am of the opinion that they are also
challenging and interesting. Finally, I would like
to stress my belief that they have a unique value
in the training of chemical engineers. The lan-
guage of biologists is not the language of engi-
neers. Therefore the researcher must begin by
distilling from the available biological descrip-
tions the engineering essence of the problem. To
accomplish this, he must first understand quite
clearly the nature of engineering problems and the
techniques of modeling. This adds an important
facet to the training of researchers in an area
which is often neglected. I think the result is not
simply someone trained to examine biological
problems, but in fact, someone better trained to
examine any engineering problem.
(References listed on page 45).




Professor of Chemical Engineering
Northwestern University
Evanston, Illinois 60201

Dynamic optimization of a chemical or petro-
leum process can be defined as the problem of
dynamically determining the desired "steady-
state" condition of that process and then deter-
mining the best way to control the process so as
to arrive at this desired steady state in some
optimal fashion. Such a control procedure nor-
mally requires an on-line, real-time digital com-
puter to monitor the process and to perform the
necessary optimization calculations as they arise.
Hence, it is obviously a form of computer con-
The mathematical formulation of the dynamic
optimization problem involves the extremization
of some integral criterion function over time,
subject to constraints which arise from the chem-
istry and physics of the process being controlled.
Several methods of attacking such a problem
have previously been proposed, including classical
calculus of variations, Pontryagin's maximum
principle, dynamic programming, and linear pro-
gramming. However, there are limitations to
each of these methods, which tend to make them
impractical for the general case. The difficulty
with both the calculus of variations and the Pon-
tryagin methods is that the optimization requires
the trial and error solution of a two-point boun-
dary value problem. With dynamic programming
the dimension of the system becomes limiting
because of computer storage requirements, and
with linear programming trouble is often encoun-
tered when attempts are made to linearize over
a wide range of operating conditions.
It has been shown1'2'4 that Lyapunov's direct
method for stability analysis can be extended
to apply to the dynamic optimization prob-
lem. Such a method can be utilized in practically
all known situations, with either linear or non-
linear system equations, as well as those in-
volving constraints on the system variables. No
trial and error solutions are required. The pres-

During the implementation of any com-
puter control procedure, it is necessary to
determine dynamically the desired "steady-
state" condition, and then to determine the
best way to control the process so as to
arrive at the desired steady state in some
optimal fashion. Such a procedure is
termed dynamic optimization. This paper
presents a method for such dynamic op-
timization, easily applied to computer con-
trol, and applicable whether or not the un-
controlled system is stable at the desired
steady state.

ent paper presents the basic principles of Wan-
ninger's approach,3 utilizing Lyapunov's direct
method for stability analysis, followed by the
results of its application to the control of a por-
tion of the Williams system,5 originally proposed
as a model for computer control studies.

Considerable effort has been expended in the
design and analysis of stable control systems.
One useful technique for the stability analysis
of a nonlinear system is Lyapunov's direct
method, as presented by Bertram and Kalman1
and applied by Koepcke and Lapidus2 and others.
The gist of this method is as follows:
Define V(X), such that:
1. V(X) > 0, X 0
2. V'(X) < 0, X - 0 (for continuous time)
AV(X) < 0, X - 0 (for discrete time)
3. V(X) continuous in X
4. V(X) -- oc, as l||X -- co

WINTER, 1968


If such a function can be found, X = 0 is a
stable equilibrium point, and the system is
asymptotically stable in the large about X = 0.
It is called a Lyapunov function, after the man
who developed this criterion. Note that the equa-
tions describing any particular system can be
transformed by a change of variables such that
X = 0 is the desired operating point.
In utilizing Lyapunov's direct method for the
dynamic optimization problem, the steady-state
and unsteady-state portions of the problem are
considered separately. Given a set of costs and
an optimization criterion, the optimal steady-
state point is first determined, independent of
transient operation. Then, knowing the desired
steady-state point, the Lyapunov method is util-
ized to determine the best control sequence to
follow as the process moves toward the desired
steady-state condition.

tor is chosen so as to make AV(k) as negative
as possible. If this is done, it has been shown4
U (k) opt = D X (k)
Where D -[iT (7))Q, (7r) ]-1 T(7r) Q (7)
The choice of the positive definite matrix Q is
not unique, and it is one of the "control parame-
ters" available to the engineer. Any choice of
positive definite Q guarantees a proper scalar
function V (X), and makes V (X) directly re-
lated to the integral error squared for the sys-
tem. The relative magnitudes of the elements of
Q markedly affect the control action, with the
result that the best Q is the one which gives the
best response to the various types of upsets
which may be expected to occur.
It should be noted that the method here pre-
sented does not select the control U(k), k = 1,

. . , h so as to minimize


Consider a linear system, involving state vec-
tor X and control vector U, according to the fol-
lowing equation:
X = p/X + EU
It has been shown4 that the solution to the dis-
crete form of this matrix differential equation is
as follows:
X (to + 7) = 4 (7) X (to) + + (r) U (to)
where r is the sample interval, and (P (r) and 4'
(r) are functions which can be numerically deter-
mined from the matrices / and e of the linear, or
linearized, system. An appropriate transforma-
tion is assumed such that X = 0 is the desired
steady-state point and U = 0 is the steady-state
control vector.
Now, choose V (X) =XT Q X, where Q is
a positive definite matrix.
Define X (to + kr) = X (k).
Then: V[X(k)] = XT (k) Q X (k), and:
AV [X(k)] = AV(k) = V [X(k + 1)] -V [X(k)]
= XT(k + 1) QX (k + 1) - XT(k)QX(k)
From above solution:
X(k+l) = (7- )X(k) + ' (T)U(k)
AV(k) = X'(k)T(7()QA (7)X(k)
-XT(k)QX(k) + UT (k) qI(7)Q(7) U (k)
+ 2UT(k)IT(7)Q(D(r)X (k)
Consistent with the Lyapunov stability cri-
terion, best control results when the control vec-


would be "mathematically optimal" for the time
period (0, nr), but instead merely selects each U
(k) so as to minimize the additional contribution
to the integral error squared during the k th
interval. This may introduce some deviation
from truly optimal behavior, but the advantages
of the proposed procedure outweigh this possible
limitation, from the viewpoint of application.
These advantages include: (1) the elimination
of the two-point boundary value problem, and its
associated computational difficulties; and (2) the
consideration of stability via the Lyapunov func-
tion, with the result that the system always
heads toward the desired point. Further work is
necessary to prove the general applicability of
the method, but it seems to work well in many
cases of practical interest (see below).

A previous paper4 presented a detailed report
of the application of the proposed procedure to
the control of a simple continuous stirred tank
reaction in which a second-order reversible reac-
tion is being carried out. Several types of upsets
were used and excellent behavior was obtained
for each. Modifications of the Q matrix allowed
flexibility of control by shifting the control em-
phasis from one variable to another.
The method has also been applied to the con-
trol of a more realistic chemical reactor system,
as originally proposed by Williams and Otto5 for


A*B- C
A&B -S. C
C*e -#P*E
P*C -06
Fig. 1.-Schematic Diagram of Williams Reactor.

computer control studies. Details of the reactor
are shown in Figure 1. Six material balances and
one energy balance can be written around the
reactor, but it has been shown3 that only three of
the material balances are independent. Hence,
the resulting system differential equations involve
four state variables (X,, Xs, X,, and T) and as
many as three control variables (FA, FL, or W).
See Reference 3 for details of these equations.
The numerical work involved in this more
recent application was carried out on the digital
computer at the Northwestern University Com-
puter Center. Briefly, the procedure was as fol-
lows. First the nonlinear differential equations
describing the reactor system were simulated via
a Runge-Kutta integration routine. Then the
system equations were linearized for use in the
control scheme. The reaction model was oper-
ated, various upsets were applied, and the Lya-
punov control actions were computed and fed to
the reactor at sample interval times. An interval
time of 0.01 hours (of reactor time) was found
to give satisfactory control of most upsets con-
sidered, although it was necessary to go to
S= 0.001 hour to get satisfactory control against
step changes in recycle concentration.
Based on previous work with the simple
second-order system, it was decided to choose
Q equal to the identity matrix, after suitable
normalization of the state variables. This choice
of Q results in a Lyapunov function which is
essentially equivalent to the sum of the squared
error of the state variables-a common criterion
for optimal control. Minimizing the derivative
of the Lyapunov function is then equivalent to
minimizing the squared error of the system
during the next time increment. Such a choice of
Q seems like a reasonable one for any system.

Three different control variables were inves-
tigated: (1) flow rate of cooling water; (2) flow
rate of A feed, keeping total feed constant; and
(3) recycle rate, keeping A and B feed rates con-
stant. It was found that with the exponential
behavior of temperature on reaction rate, control
of cooling water alone gave good behavior. The
addition of a second or third control variable to
help control concentration did little to improve
the overall response. Hence, the particular runs
reported here used only cooling water rate as the
control variable.
Figure 2 illustrates the response of the Wil-
liams reactor to a step change of 10'R in the
temperature of each feed stream. The reactor
was at steady state at time = 0, when the step
was applied. It is seen that the uncontrolled re-
actor responded by moving away from the desired
operating point, and continued moving away as
would be expected for an unstable system. The
Lyapunov controlled response, however, was
stable, and the reactor remained at the desired
operating point.
Figure 3 shows the response to initial offsets
of 0.01 in each of the state concentration vari-
ables and of 10'R in reactor temperature. A sub-





-X I l


0 0.2 0.4 0.6

0.8 1.0

Fig. 2.-Response to Step Changes of 100R in the
Three Feed Streams.

WINTER, 1968


- f
-� ~ X6 J



0 0.2 0.4 0.6 0.8 1.0
Fig. 3.-Response to an Initial Offset in Reactor Tem-
perature and Concentrations.

stantial final error, or offset, occurs for the un-
controlled reactor. The Lyapunov controlled re-
sponse is limited by the bound on the cooling
water rate. If the cooling water capacity were
increased, the system would return to the steady-
state point more rapidly.
Figure 4 shows the response to a step change
in recycle composition as well as inlet feed tem-
perature. The recycle composition was changed
such that components 1 and 6 were increased by
10 percent each and component 2 was decreased
by a corresponding amount. Again, the uncon-
trolled response was unstable, while the con-
trolled response was excellent for such a large
change. The sample time, r, was decreased to
0.001 hours for this case.
A conventional three-mode control system
was also designed for the Williams reactor and
operated to give data to compare with the Lya-
punov control behavior. The reactor temperature
was used as the measured variable, and the entire
system was simulated on the digital computer,
using the control equation:

dT 1 t
W (t) = K T+ T dt T, + T dt
F dt T, Jo

For a step change of 10' R, in feed tempera-
tures, a "best" set of constants was found by
trial and error, considering both the integral
error squared and the final offset. This set was
Ke = 800, TD - 0.1, and Ti = 0.1. The response
of the conventional control system using these
constants was almost identical to that shown in
Figure 2, for the Lyapunov controlled system.
For an initial offset 0.01 in state concentration
variables and 100R, in reactor temperature, a
radically different "best" set of constants was
found - Kc = 3200, TD = 0.1, TI = 1000; and
again the response with conventional control was
the same as that for Lyapunov control, as shown
in Figure 3.


-- X5
01 -

0 X5

)x -
I, -


- L-- - -
X5 X


SO.5 1.0 1.5 2.0
Fig. 4.-Response to a Step Change in Inlet Feed and
Recycle Temperatures and Recycle Composition.

It appears that conventional control does al-
most as good as Lyapunov control when the con-
troller constants are set at the "best" set for
a particular type of upset. But this cannot often
be done. Figure 5 gives the response of a conven-
tional controller to a step in feed temperatures,
with the constants set for the initial offset case.
Control here is not as good as that shown in
Figure 2, the comparable Lyapunov case. The
discrepancy is even greater when the best tem-










s 0 0.2 0.4 0.6
Fig. 5.-Response to a Step Change of
Three Feed Streams with a Conventional





Fig. 6.-Respo
perature and Con

WINTER, 1968

x I I


perature step constants are used to control initial
offset. Figure 6 shows the results of such a test,
in which the response is completely unstable,
rather than stable as in Figure 3, the comparable
Lyapunov case. The Lyapunov method operates
equally well for both types of upsets, which is not
true of conventional control.





- I

1. Bertram, J. E., and R. E. Kalman, AIEE Trans, 77
602, 1958.
2. Koepcke, R., and L. Lapidus, Chem. Eng. Sci., 16,
252, 1961.
3. Wanninger, L. A., Ph.D. Thesis, Northwestern
University, 1965.
4. Wanninger, L. A., and W. F. Stevens, Can. J. Chem.
Eng., 44, 158, 1966.
5. Williams, T. J., and R. E. Otto, Trans AIEE, 79,
Part 1 (Comm. and Elect), 458, 1960.

Dr. William F. Stevens received his undergraduate
education at Northwestern University, graduating in 1944.
After 2� years as a radar officer in the U. S. Naval Re-
serve, he continued his professional education at the
University of Wisconsin, being awarded the Ph.D. in
T 1949. He then spent two years as a research chemical
engineer with the B. F. Goodrich Company. He joined
the faculty of the Chemical Engineering Department at
S I I Northwestern University in 1951, and has been there
0.2 0.4 0.6 0.8 1.0 continuously since that time, being appointed Professor
in 1964. He has published over 35 technical papers, pri-
marily in the area of process control and process optimi-
nse to an Initial Offset in Reactor Ter- zation. Recently he has spent a portion of his time in
centration with Conventional Three-Mode administrative activities as Associate Dean of the North-
western University Graduate School.

Dynamic optimization has been shown to be
possible utilizing a method related to the Lyapu-
nov stability criterion. The method, as presented,
is simple and relatively easy to apply. It seems
to work well in control of a reactor system which
is unstable without control. Additional work is
necessary, and is currently being carried out, to
firm up the mathematical justification for the
procedure followed. So far, it works well for
cases studied, and requires a minimum of cal-
culation, so it is a reasonable approach to follow.
SExtension to other systems can follow directly
from the example of this paper since the dimen-
R th sion of the state vector does not appear to be a
1Thr d i mitin g factor.
Three-Mode limiting factor.



Makes The

Chemical Engineer

General Superintendent
Process Department
E. I. du Pont de Nemours & Company
Chambers Works
Deepwater, New Jersey

There are many ways in which a chemical
engineer can be characterized, but among his
many attributes his versatility is outstanding.
This is as it should be because the problems
and opportunities which confront the practicing
chemical engineer demand that the individual
be adaptable and reach out to almost any disci-
pline in his search for the best solution to a
In evaluation of the chemical engineer in in-
dustry, judgments have been passed on the kinds
of technical training and proficiency that are re-
quired to contribute effectively. Opinions have
been expressed that sales and manufacturing re-
quire an individual with certain technical train-
ing, strengths and interests in contrast to that
required for research and development. In prac-
tice the individuals who are concerned with prob-
lems in all the areas must have sound technical
training to achieve above-average performance.
The basic difference between the jobs can be
related to how the technical training is applied,
personal interests and qualities of the individual.
Chemistry plays a basic role in the develop-
ment of the engineer. It is vital to the solution
of problems in all areas with which chemical
engineers are concerned. The difference occurs in
how basic chemistry is used or applied to the
solution of problems.
The chemical engineer who is concerned with
R & D activities must have a good knowledge of
chemistry and he must be able to use that knowl-
edge to solve research problems. These may be
related to process analysis, the planning of ex-
periments, design of laboratory apparatus, inter-
pretation of results, development of basic data,

The chemical engineer is character-
ized by his versatility-his ability to ap-
ply a varied training to problems as they
relate to research, development, works en-
gineering, manufacturing and sales. The
recognition and solution of these problems
require that the engineer have, among
other qualities, a knowledge, understand-
ing, and an ability to communicate his
thoughts on the relationship that exists
between the chemical and engineering
aspects of a problem.
The practicing chemical engineer re-
lies heavily on organic and physical chemis-
try-to a much lesser degree on qualita-
tive and quantitative analysis-in his var-
ied technical activities.

design of pilot plant equipment, etc. The knowl-
edge and ability to use chemistry is basic to the
effective solution of chemical engineering prob-
lems in a research or in a development assign-
The chemical engineer who is concerned with
the design of process equipment or is responsible
for plant design must have an understanding of
all phases of chemistry and he must have the
ability to interpret this understanding in his
The research engineer is generally concerned
with the study of reaction systems. The basic
data that are developed completely describe and
qualify the features that must be recognized to
satisfy the process. The design engineer must
extend his understanding of the chemistry to
interpret the basic data in the form of a workable


The Chemical Engineer who is concerned with the design of
process equipment or is responsible for plant design must have
an understanding of all phases of chemistry and he must have
the ability to interpret this understanding in his design.

The design engineer is frequently committed
to take a greater responsibility for separation
and auxiliary equipment. Without a knowledge
and understanding of chemistry and physical
chemistry the design engineer will not be in a
position to evaluate the basic data and the re-
quirements and limitations that the chemistry
may impose on the design of the equipment and
The chemical engineer who is concerned with
manufacturing must have an understanding of
chemistry and he must be able to apply that un-
derstanding to analyze problems to achieve effec-
tive control of his operation. The modern manu-
facturing supervisor is much more than an ad-
ministrator. He must have an ability to apply
an understanding of chemistry to control his op-
eration, diagnose difficulties, and recognize the
opportunities for technical improvements. He
must be able to intelligently and clearly present
a problem proposal to a chemist and have suffi-
cient knowledge to interpret a recommendation
for a correction or an improvement.
The chemical engineer who is concerned with
sales must have a good understanding of chemis-
try to communicate information about the chemi-
cal properties of his company's product. He must
be able to understand and communicate the cus-
tomers' technical problems and needs to his com-
pany's technical center. The sales engineer today
is much more than a peddler or an individual who
takes orders. He may be a trained, experienced
chemical engineer who knows his product and is
sensitive to his customer's problems and needs.
His technical strength is such that in many
cases he can solve chemical and engineering prob-
lems for the customer on the spot, and he can
participate in an intelligent discussion of techni-
cal needs to present an analysis for his company
that identifies product deficiencies and require-
ments. In many cases he may suggest either an
approach, a program, or possibly a solution to
the problem.

In order to understand how a chemical engi-
neer uses his knowledge of chemistry to enhance
his professional development we should examine
the manner in which he gains experience in in-
The new graduate possesses a strong techni-
cal appetite and he demands that his first assign-
ment take maximum advantage of his training
in the engineering discipline. In general then,
the new hire is assigned to a research and de-
velopment activity. As the individual gains ex-
perience he identifies interests and personal
qualities which, when superimposed on his basic
technical strengths, can provide him with a
higher degree of personal and professional
achievement than he can realize as a career en-
gineer. He then may pursue a career in adminis-
tration or continue his professional development
in sales, manufacturing, research, development,
etc. It is well to emphasize again that the exten-
sion of his career is based on his reinforced tech-
nical training, personal qualities and interests;
but underlying all of these directions into which
his career may extend is the basic need for a
working and communicating knowledge of chem-
In the discussions which we have held with
individuals who are actively engaged in the areas
that have just been discussed, it was generally
agreed that the following needs for chemistry
General-a thorough knowledge of chemical
reaction principles and mechanisms, particu-
larly in organic chemistry.
Chemistry-A knowledge of chemistry (or-
ganic and inorganic) is vital to a chemical engi-
neer to ensure his ability to solve problems, to
design facilities and to communicate with his
colleagues, the chemists and the customer.
Physical Chemistry-for the engineer per-
haps the most important branch of chemistry.
When combined with the derivatives of mechan-
ics, i.e., mass and energy transport, it can serve

WINTER, 1968

as a foundation for the solution of most problems
that may concern a chemical engineer.
Qualitative and Quantitative Chemistry-
Benefit may be derived from the manipulative
skills which are developed. It is felt that this
training can be achieved in a shorter time and
the information should be presented in a survey
Chemical engineers should be exposed to some
aspects of analytical chemistry and should be
familiar with instrumental methods that can be
used for raw material, process streams, and
product analysis.
The modern chemical engineer must have a

practical knowledge of all phases of chemistry,
regardless of his field of interest. The curriculum
should place greater emphasis on organic and
physical chemistry and less stress on qualitative
and quantitative analysis.

Mr. Thaddeus W. Tomkowit is general superintendent
of the Process Department at the Chambers Works of
the duPont Company, Deepwater, N.J. He received the
Ch E degree in Chemical Engineering from Columbia
University in 1942 and has experience in research, de-
velopment, engineering, and manufacturing with the du-
Pont Company. He is past national chairman of AIChE
Student Chapters Committee and presently is a national
director of AIChE.

~S Ilews

Readers and others are invited to sub-
mit news items and technical announce-
ments of professional interest for publica-
tion here. Consideration must be given to
the fact that CEE publishes quarterly.

STILLWATER, Okla.-The second annual
educational conference on process design will be
held on the campus of Oklahoma State University
here March 4 and 5. The lectures at this confer-
ence will be on the design of process reactors.
Sponsored by the School of Chemical Engi-
neering, the two-day meet will feature lecturers

with academic and industrial backgrounds, ac-
cording to Prof. Wayne C. Edmister, conference
In addition to general considerations in re-
actor design and analysis, subjects to be covered
include gas-liquid and gas-solid non-catalytic re-
actors, mathematical modeling of reaction rate
data and chemical reactors, reactor and regen-
erator analysis and design, and control and opti-
mization applications.
Lecturers for the conference are Prof. J. J.
Carberry, Department of Chemical Engineering,
University of Notre Dame, Notre Dame, Ind.; Dr.
J. R. Kittrell, Chevron Research Corp., Richmond,
Calif.; and Dr. V. W. Weekman, Jr., Mobil Re-
search and Development Corp., Paulsboro, New
Information regarding technical content of
the conference is available from Prof. W. C.
Edmister. Housing and registration forms are
available from Dr. Monroe W. Kriegel, director,
Engineering and Industrial Extension, Oklahoma
State University, Stillwater, Okla. 74074.


-t . .. " '' " "::, ' "

Marathon Oil Company was founded in Find-
lay, Ohio in 1887; however its ultramodern
Denver Research Center is located at the foot-
hills of the Rockies. The company is a producer,
transporter, refiner and marketer of crude oil and
petroleum products on five continents throughout
the world.
The Denver Research Center was established
to make discovery of new petroleum reserves more
economical, to help recover a larger percentage
of oil in present fields, to develop more profitable
refining and chemical processes, and to develop
new products.
Marathon employs more than 8,000 persons
at its offices around the world including its head-
quarters in Findlay. There are over 300 em-
ployees at the Denver Research Center of which
more than half are scientists and engineers.
Using engineering research to determine ways
to recover more of the oil from known deposits
is an important part of the work at the Research
Center. It includes projects aimed at stimulating
wells so they will produce more oil; in situ com-
bustion; and fluid injection processes, such as
miscible displacement, which are more efficient
than conventional techniques where gas or water
are used to drive oil to a production well.
Reservoir mechanics comprise another signifi-
cant part of the engineering work at the Denver
Research Center. The transient behavior of oil
WINTER, 1968

reservoirs and the flow of fluids through porous
media are important phases of this work. Mathe-
matical models, which simulate reservoir behav-
ior, provide insight into future behavior of oil
bearing reservoirs.
Chemical engineers are also engaged in the
pilot plant study of existing refinery and chemical
processes as well as in the evaluation and devel-
opment of new processes and new chemicals.
Projects are underway, for example, on petro-
chemical processes to make monomers and other
basic components for polymers.
At Marathon's Research Center, qualified en-
gineers are provided with both the challenge and
incentive in supplying answers to these problems.
Your further inquiry is invited.

Mr. L. Miles
Personnel Supervisor
Dept. CE-1, P. O. Box 269
Littleton, Colorado 80120




[i pi� views and opinions

On what sort of place, if any,


studies should have in graduate


Department of Chemical Engineering
University of Minnesota
Minneapolis, Minnesota 55455
Question: On what sort of place, if any, theo-
retical and mathematical studies should have in
graduate chemical engineering research.
In order to contain our subject within reason-
able bounds we propose to treat it under four
points of inquiry:
I. whether mathematical studies have any
place in the chemical engineer's training;
II. whether mathematical and theoretical
studies are practical or contemplative;
III. whether the methods of mathematical
and theoretical studies are conformable to those
of engineering;
IV. whether mathematical rigor is a notion
from which the engineer may profitably be dis-

Have mathematical studies any place in the
chemical engineer's training?
1. It would seem that mathematical studies
have no place in the training of a chemical engi-
neer whose true nature is fulfilled in making and
doing things. Now the end of mathematics is
not to do or make anything. Therefore mathe-
matical studies are alien to the engineer's train-
2. Moreover, there are more important sub-
jects in the engineering curriculum, which is
already a full and difficult one. Therefore mathe-
*Presented at the Annual Meeting of ASEE, June
19-22, 1967.

Four questions on the suitability of
mathematical studies are raised; namely,
whether they have a place as training,
whether they are practical, whether their
methods are suitable and what is the role
of rigour.

matics should have little part in the curriculum.
3. Again, the training of the engineer should
be directed towards developing those faculties
that he will need in industry. The principal
faculty of an engineer is to make responsible
judgments and correct decisions on the basis of
information which is always incomplete and often
faulty. Now there is no analogous situation in
mathematics and therefore it adds nothing to
the engineer's training.
On the other hand, mathematics is where the
art of generalization is best seen and learned
and where the formal object of any science is
best displayed. Simple examples free from the
compounded difficulties of the material objects
of chemical engineering are often didactically

1. Even if the formal object of mathematics
is not to make any material thing it is neverthe-
less often the efficient cause of a good design.
Moreover the engineer takes pride in doing for
a penny what any fool may do for a dollar. Now
if each problem must be considered de novo as
it arises without the generalizing power of
mathematics he is certainly not practicing the
economy of which he is so rightly proud. Fur-



- -

their it may be questioned whether mathematical
studies are so ineffective for does not the poet
We are the music makers,
We are the dreamers of dreams,
Wandering by lone sea-breakers,
And sitting by desolate streams;
World-losers and world-forsakers,
On whom the pale moon gleams:
Yet we are the movers and shakers
Of the world for ever, it seems.
2. To the second objection we may reply by
asking what constitutes a more important sub-
ject. Certainly mathematics must take its place
along with chemistry, physics and engineering
science in competition for the student's attention
and not arrogate to itself a primacy which in this
context it does not possess. But it may be argued
where, if not at the university, has the oppor-
tunity to become acquainted with both the utility
of the methods and beauty of the notions of mod-
ern mathematics; as the poet2 says, 'Omne tulit
punctum qui miscuit utile dulci.'2
3. Though it be true that the engineer's task
is to make decisions on the basis of incomplete
information, yet he can gain part of the experi-
ence on which this ability is founded by the study
of mathematical models. For example, the for-
mal nature of an exothermic reaction is to pos-
sess at each composition a temperature at which
the reaction rate is greatest, which temperature
is somewhat lower than the equilibrium tempera-
ture for the same composition. And this may be
learned, not only by experience with the material
objects of chemical engineering, namely reacting
chemicals and reactors, but more generally from
experience with the formal objects of kinetics,
namely the kinds of reaction rate expression that
are found to be useful. The engineer may thus
supplement his incomplete information on a par-
ticular reaction by an understanding of the gen-
eral behavior of a whole class of reactions.

Are mathematical studies practical or con-
templative ?
1. It would seem that mathematical studies
are not part of any practical science, for Aris-
totle says "a practical science is that which ends
in action."3 Now mathematics is one of the for-
mal sciences whose truth depends on their in-
ternal consistency and not upon any relation to

the observable world as is the case with the
factual sciences.
2. In the hierarchy of the sciences the factual
sciences occupy an intermediate position between
the formal and the applied. Now engineering is
clearly an applied science and practical, therefore
mathematics is far removed from it and wholly
On the other hand it is generally acknowl-
edged that the purist attitude of such eminent
mathematicians as the late G. H. Hardy (who, in
his Mathematician's Apology,4 crowns the theory
of numbers as queen of the mathematical
sciences because of its [her] complete useless-
ness) is an extreme one. Mathematical thought
is diverse in its ramifications and penetrates to
other disciplines.

1. Nothing is more practical than a good
theory, for to be good it must have clear indica-
tion within itself of how it may be proved, i.e.,
tested. Again, theory comes before experiment
since some vision is needed to correctly formulate
any experiment. Therefore theoretical studies
are of practical value.
2. Moreover, although the division of sciences
into formal, factual and applied is a useful one, it
would be a mistake to interpret it rigidly and
refuse to recognize the interpenetration of ideas
throughout them. For though applications of
such a subject as number theory are rare, this
does not mean that they may not be found nor
will the theory be defiled if they are.

Are the methods of mathematics conformable
to those of engineering?
1. It would seem that the methods of the
mathematician have little or nothing in common
with those of the engineer. For mathematics
is an axiomatic science proceeding by strict de-
duction, and engineering lore is founded on direct
experience and proceeds by trial and error.
2. Again the technique of the chemical engi-
neer is to scale up his apparatus by stages, and
wisely so for he deals with processes that are
rarely understood in any complete sense. This
procession of scales has no part in mathematics.
3. Moreover, the mathematical approach will
often start with so drastic an idealization as to

WINTER, 1968

Better soap may be made, but better living is not attained
if cleanliness has become the first rather than the second

take it one remove from engineering realities at
the outset.
On the other hand, rational thought must
permeate all purposeful human activity, including
that of the chemical engineer. Now rational
thought is to be seen par excellence in mathema-
tics and so learned there.

1. It is false to assume that, because the ulti-
mate presentation of mathematical results is
deductive, the context of discovery is also
purely deductive. In fact mathematics requires
as much imagination as it does logic, and proceeds
by the pattern of conjecture and confirmation
or refutation familiar in all sciences. Moreover
it has its own experiences of theory building
which are just as valuable to the engineer as the
more banausic experiences of plant building.
2. Even though scale-up has no direct coun-
terpart in mathematical theory it is served by
the notions of dimensional analysis. The correla-
tions of empirical data by means of dimension-
less groups need to be informed by a proper un-
derstanding of the underlying equations or most
spurious results can be generated (cf. P. N.
Rowe's illustration5). Although we are still some
distance from completely a priori design of
chemical reactors, the progress of scaling up is
now often greatly expedited by proper mathe-
matical modelling at an early stage.
3. Furthermore, though a problem is often
idealized considerably when formulated in mathe-
matical terms, this does not necessarily take it
completely out of touch with reality. There is a
hierarchic and iterative aspect to idealization.
A situation may be grossly oversimplified at first
and yet its analysis can form the basis for an in-
terconnected set of problems in which more com-
plete solution is built up by successively including
more refinements and evaluating their effects.

Cannot the engineer be dispensed from the
notion and habit of mathematical rigor?
1. The mathematician's notions of rigor

would seem to be wholly out of place in the con-
text of engineering applications. For rigor im-
plies exactitude and we have admitted that a
mathematical model is always an idealization
and its exactitude is therefore an artifact of
analysis and does not belong to the real world.
2. Moreover in any model the constants and
parameters will be imperfectly determined. It
seems therefore foolish for the engineer to worry
about existence theorems, strict deduction, neces-
sity and sufficiency and the like, when his basic
quantities are always open to error.
3. With the power of modern computers nu-
merical solutions can often be obtained faster
than any general properties of the solution can
be rigorously proved and a numerical answer is
what the engineer wants. On the contrary, "In
physical theory, mathematical rigor is of the
essence" (so Truesdell6).

1. If a mathematical model of a real situa-
tion is constructed, its utility will be judged by
the conformability of its consequences to what
may be observed. Now if these consequences
have not been rigorously deduced, a comparison
between them and observations that may be
made is devoid of meaning and has nothing to
say to the validity of the model. The whole en-
deavor of theoretical analysis is thereby rendered
futile and this because it is not true to itself.
For though the notion of rigor exists only for
mally in the mind, it exists fundamentally in an
instance of mathematical analysis. A sloppy an-
alysis is therefore not 'a good enough approxi-
mation for engineering purposes'; it is a de-
formed creature that has repudiated its own
essence. This does not mean that it is always
possible for a given person, or even any person,
to provide a full, complete and rigorous demon-
stration of all propositions. But this failing must
be honestly recognized as a fault, which may be
corrected later by the person himself or by some-
one more able than he. It is only a snare when
it is overlooked. When it is derisively ignored
it is not only a snare but a corruption.


2. What we have said above sufficiently an-
swers the second objection, but it may further
be pointed out that a proper mathematical analy-
sis can evaluate the effect of the errors that
there will be in the estimation of constants. It
can also suggest ways in which these constants
may be determined more accurately and pre-
scribe confidence limits for them.
3. Nowhere is the need for rigorous mathe-
matical theory better seen than in the present
day use of the computer. Without an existence
theorem there is no assurance that the numbers
ground out by the numerical solution of an equa-
tion have any meaning. There may be some in-
tuitive presumption of their meaningfulness but
let this be honestly recognized. The particular
virtues of the digital computer are its speed,
"careful attention" and "indefatigable assidu-
ity"7. These may be exploited, but they need also
to be controlled by a rationality which is too
easily sacrificed in a culture which appreciates it
so superficially. It is seldom wise and never de-
sirable to start computing before obtaining a
good qualitative feel for the form of a solution;
the ability to do this is one of the fruits of
mathematical training.
We therefore conclude that there is a valid
place for theoretical and mathematical studies in
chemical engineering research, provided that
their virtues and limitations are properly under-
stood and held in balance. When unwarranted

claims or unnecessary derogations are made from
either direction, then the whole temper and spirit
of natural philosophy is vitiated. Better soap
may be made, but better living is not attained
if cleanliness has become the first rather than
the second virtue.

1. O'Shaughnessy, A. W. E. Ode from "Music and
Moonlight" London. Chatto & Windus. 1874. See also
many anthologies and a selection of the Poems of Arthur
O'Shaughnessy by W. A. Percy. New Haven. Yale Uni-
versity Press. 1923.
2. Quintus Horatius Flaccus. Ars Poetica 343.
3. Aristotle, Meta, II, 1, 933 b21.
4. Hardy, G. H. A Mathematician's Apology Cam-
bridge, at the University Press. 1948.
5. Rowe, P. N. "The Correlation of Engineering Data,"
The Chemical Engineer. March 1963. 69-74.
6. Truesdell, C. A. Handbuch der Physik III/1, Sec.
4, 1960. p. 231.
7. Dickens, C. The Posthumous Papers of the Pick-
wick Club Part I, opening sentence. March 31, 1836.
London. Chapman and Hall.

Dr. Rutherford Aris was born in England in 1929,
studied mathematics in the University of Edinburgh and
taught it to engineers there. He has degrees from the
University of London (B.Sc. (Math); Ph.D. (Math. and
Chem. E.); D.Sc.). He worked a total of seven years in
industry, but since 1958 he has been in the Chemical
Engineering Department at the University of Minnesota
enjoying the liveliness of its interests, both technical and
cultural, and endeavouring to contribute to this vitality
and communicate it to his students.

Summer School for Teachers of Chemical Engi-
neering which was held at Michigan State Univer-
sity last June. For that reason, we have on hand
a certain amount of material that will be pub-
lished during the year. But we would also like to
include in each issue one or two articles on chemi-
cal engineering education that have been sub-
mitted to us by people in the universities and in
industry. Accordingly, your contributions are
definitely solicited.
wishes to provide something of interest to the en-
tire profession: educators in the university and
engineers in industry; the large graduate-oriented
departments and those with small undergraduate
programs; the theoretically-inclined and the prac-
tice-oriented; chemical engineering professors
and chemical engineering students. But while we

serve all, we do not intend to avoid controversy
nor will we shirk our responsibility to speak out
editorially on matters we feel are of importance
to the profession. We hope our readers will do
us the favor of writing when they do not agree
or also when they do agree with something they
CATION. In later issues we intend to publish
letters as well as articles that set forth differing
views on important topics. We are always inter-
ested in your ideas as to how we can make
better journal. With your continued help and
support we can provide an important and needed
service to both the teaching and the engineering
professions, to our students, and to our society as
a whole.
Ray Fahien

WINTER, 1968


In August 1492, the crews of Columbus'
expeditionary ships Santa Maria, Pinta and
Nifia took enough water from this well in Palos,
Spain to last until they reached the New World.
Now, 475 years later, the well is still in use,
but as a tourist attraction.
Several Fluor employees and their families
toured this part of Spain during 1967. Why
not? They were living there as part of the team
building a refinery for Rio Gulf de Petroleos
at La Rabida, the site from which Columbus
actually sailed. The Rio Gulf project is just one
of some thirty foreign jobs currently under way
by Fluor.
Fluor's principal engineering centers are
located in the United States and Europe. Almost

every plant Fluor builds is engineered in one
of four support facilities ... Los Angeles, Hous-
ton, London or Haarlem, Holland. But an en-
gineer who starts at one of these offices may
eventually end up at a foreign jobsite (if he
chooses to do so).
Right now there are openings in Los
Angeles and Houston for Chemical Engineers
with a B.S. degree or higher. Areas of specialty
include process design, process development,
computer and project engineering.
Why not join a company with an
international flavor and with international
opportunities? For more details write our
college recruiters, Frank Leach in Los Angeles
or Ed Hines in Houston.

2500 South Atlantic Boulevard, Los Angeles, California 90022
3137 Old Spanish Trail, Houston, Texas 77021


Are engineers selling their birthright

for a place in the ivory tower? *

909 Caldwell Street
Piqua, Ohio

When I graduated from college, now nearly
forty years ago, engineering was defined rather
simply as "the art of utilizing the knowledge of
the sciences in the production of machines and
materials for the benefit of mankind". There was
also included some reference to the fact that
engineering was to be accomplished for a profit.
Science was defined as "an organized body of
knowledge." I don't recall any definition of the
word "art," but I would suggest that the word
art refers to the "doing" and science refers to
the "knowledge" used in the "doing." Perhaps
skill would be a better word.
In any field of endeavor, both skill and knowl-
edge are required. Even the scientist, engaged
in pure research, must have some basic skills.
At the very minimum, he must be able to present
the results of his work to others in a satisfactory
manner. On the other hand, the artist, engaged
in abstract art, must have some basic knowledge
of the materials and techniques necessary for
accomplishment of his work.
In recent years, there has been a tremendous
growth in the accumulation of knowledge. As a
result, there has been a steady upgrading of the
term "science." This is called the "Scientific
Age" and the "Scientist," once considered a pecu-
liar individual working in the mysterious con-
fines of something called a laboratory, has now
become a well-known and highly respected indi-
vidual. No one can regret this development.
Public recognition of the valuable work of the
scientist has been long overdue. However, there
are some side effects of this trend that are not so
desirable. While respect for knowledge has been

*Presented at the Annual Meeting of ASEE, June
19-22, 1967.

increasing, respect for the skills necessary to put
this knowledge to use has been steadily declin-
ing. For example, when a space ship has been
put into orbit successfully, it is hailed as a great
"scientific" achievement. When there is a fail-
ure, it is referred to as an "engineering" failure,
or perhaps less painfully, as a "technical" failure.
The terms "engineering" and the title, "engi-
neer," are being definitely and rapidly down-
It is disappointing to note that even among
the members of our own profession, there is a
reluctance to use the title "engineer." In review-
ing the biographical sketches of recent candi-
dates for offices of one professional society, it
was noted that not a single candidate referred to
himself as an engineer. The most commonly used
titles were Executive, Administrator, and Edu-
cator. (No one, however, referred to himself as a
Engineering, as a profession, and engineers,
as individuals, have been known and respected,
primarily for their accomplishments; i.e., the ac-
tual production of materials and machines. To-
day there seems to be a growing tendency to be-
lieve that engineers should be respected for their
knowledge and not for their accomplishments.
A number of years ago, a young engineer of
my acquaintance, was proud of the experience
he was getting in heat exchanger design. He
pointed out that he had "designed" nine heat ex-
changers that week. "How many of your heat
exchangers have been built?" I asked. "Oh, none
of them have been built, but what has that got
to do with it? I still have the design experience."
Actually, of course, he had experience in applied
mathematics-not heat exchanger design.
At a more recent technical meeting, I heard

WINTER, 1968


If engineering as a profession, and engineers as individuals, are
to retain a prestige based on accomplishment, then there
must be a reversal of the present trend to confine engineering
to design and management offices.

a discussion on heat exchanger design that went
something like this: "There are about 128 varia-
bles that affect heat exchanger design. Of these,
all but about 32 can be considered to be of negli-
gible importance. With the 32 variables, we could
design the ideal heat exchanger. It would require
about $15,000 worth of computer time for each
exchanger and my company objects to this. I
know that these exchangers sell for about $3000
and there would be a net loss of $12,000 on each
exchanger, but think of the valuable information
we would get." Unhappily, for the "engineer",
the company he works for sells heat exchangers
for a profit, not "valuable information."
In a conference on a recent plant design, I
asked the design engineer if he felt that the re-
sulting plant would be "operable." "What do
you mean?" he asked, with a perplexed expres-
sion. "Well, can the operating engineers operate
this plant satisfactorily?" He was astonished.
"I couldn't care less!" was his reply. "This de-
sign is based on methods established in the tech-
nical literature. I have checked my mathematical
computations and there are no errors. If it does
not operate satisfactorily, this is of no concern to
I submit that the attitudes reflected above
do no good to the engineering profession and are
not the proper attitudes for an engineer.
The rapid expansion of the sciences in recent
years does create difficult problems in the educa-
tion and training of chemical engineers. It has
seemed to me that the chemical engineer has al-
ways been somewhat more fortunate than his
colleagues in mechanical and electrical engineer-
ing, since he has had the additional training in
chemistry as well as the basic mathematics and
physics. Now, the expansion in physics and
mathematics places an additional burden on the
chemical engineering student. In addition to
this, the present recommendations that 20% of
the students' time be devoted to the humanities,
adds still another burden.
I would suggest that the whole humanities
requirement be eliminated. In reviewing the
catalogue of one midwestern university, I noted
their requirement for credit for a course in the hu-

manities. "The course must be one that adds to
the student's knowledge in a given field, but not
to his skill." For example, he may take a course
about the theater, but he may not take a course
that is designed to develop his skill as an actor.
He may take a course about music, but not a
course that is designed to teach him to play a
musical instrument.
It is inevitable that time spent in the labora-
tory courses has been, and will be, reduced. In
my college years, we were required to take
courses in forging and heat treating of metals
and also a course in pattern making-laboratory
courses taken during the summer months. I still
have a set of wrenches that I laboriously forged
during that summer. Unfortunately, I have never
found a bolt head or nut that they would fit. The
case hardening was excellent and I cannot grind
them down to fit anything, but they are nice
We also had some sixteen clock hours per
week of quantitative analysis each semester dur-
ing the second year. I do not recommend that
we return to this; however I do believe that we
have reduced that part of the curriculum that
can be defined as "training," as opposed to
"education," to beyond tolerable limits. Recently,
the dean of one engineering school asked me,
quite seriously, if the courses in chemistry could
not be eliminated from the curriculum in chemi-
cal engineering. "I know it sounds silly," he said,
"but with the addition we have to make to the
curriculum, we simply do not have time to pro-
vide the laboratory hours required."
One area in which I believe that laboratory
work has been reduced beyond tolerable limits,
is in engineering drawing. Many young engi-
neers not only cannot produce a satisfactory
drawing, often they cannot read one. 0
Some colleges have attempted to meet this
problem by adding a fifth year to the course of
study required for the B.Ch.E. degree. This has
resulted in a drop in enrollment and to offset this,
they have worked out a combined curriculum that
would award the student an additional degree in
Business Administration. I do not believe that a
student can be given adequate training in both


disciplines to justify this program. He is either
a Chemical Engineer with a minor in Business
Administration, or he is a graduate in Business
Administration with a minor in Chemical Engi-
I am aware of the fact that a number of the
larger chemical companies subscribe to the theory
that chemical engineering curriculum should be
heavily weighted with courses in the sciences.
They say, "You give them all the mathematics,
chemistry, physics, etc., that you can. We will
teach them the necessary engineering after they
come to work for us." Such a procedure does an
injustice to the student who expects to be trained
in principles of engineering. It also puts the stu-
dent who elects to work for the smaller compa-
nies, at a disadvantage.
When I returned to teaching after some years
in industrial work, I introduced a new course in
plant design. The course was not intended to
develop proficiency in process calculation, it was
designed to acquaint the student with the myriad
problems which arise from the very beginning
of a project. It included site selection, literature
survey for necessary data and estimating meth-
ods for both equipment size and cost. The course
was given in the last half of the senior year.
About midway through the course, one student
came to me with this comment: "I came here to
become an engineer, although I had not decided
on which field of engineering. I selected chemical
engineering because I met another freshman that
I liked and he was going to take chemical engi-
neering. For three and a half years, I have been
taking courses in Chemistry, Mathematics, Phy-
sics, English, etc., but I never knew just what
chemical engineers did until I started this
This course was very popular with the stu-
dents. Actually, it could be given in the last half
of the second year or first half of the third year.
If the student had some idea of the problems of
chemical engineering, at an early point in his
training, he would have a better understanding
of the requirements for process design and unit
operation courses which would follow.
There is a growing concern among some engi-
neering companies for the increasing difficulty
they are experiencing in getting new plants "on
stream." As a vice president of one engineering
company put it, "We design and build a new fa-
cility and then send out a 35-year-old "hot shot"
to operate it. Then we find out that he simply

If the present trend toward higher academic
achievement for the professional engineer
continues, there will be an unavoidable
gap between the engineer and the
supervision of engineering at the
working level.

cannot do it."
Having had some experience in operations,
it is my opinion that almost all difficulties in
operating a plant stem from lack of basic engi-
neering knowledge. Actually, I might say, from
lack of mechanical and electrical "know-how."
For example, while inspecting a pilot plant in-
stallation, I pointed out to the project engineer
that his pumps had not been properly grouted
in. He was highly indignant. "We consider
grouting to be window dressing and we do not
waste money on this kind of thing." He was
wasting money, however, on constant piping re-
pair and packing problems, although the size
of the operation was such that it was not too
important. The point is, that this was the hall-
mark of a careless workman and he had a Ph.D.
in chemical engineering from one of the leading
When I was a student, we had an "Engineer's
Day" each year, when we dressed up the labora-
tories for a public inspection. I think that the
good Dr. James R. Withrow, in one of his humor-
ous moods, was responsible for one exhibit. Along
one wall of the laboratory was a display of such
equipment as specific gravity spindles, viscosi-
meters, analytical balances, etc. The title card
read, "Proficiency in the use of this equipment
required of all candidates for the B.Ch.E. de-
gree." The next exhibit was a table containing
pipe wrenches, chisels, hammers, etc., along with
a card stating, "Proficiency in the use of this
equipment required of all candidates for the
M.Sc. degree. The last exhibit consisted simply
of a wheelbarrow and shovel, along with the
sign, "Proficiency in the use of this equipment
required of all candidates for the Ph.D. in Chemi-
cal Engineering". At the time, I thought this
simply a macabre jest, but as the years have gone
by, I have learned to appreciate the wisdom dis-
played in this exhibit.

WINTER, 1968

If engineering as a profession, and engineers
as individuals, are to retain a prestige based on
accomplishment, then there must be a reversal of
the present trend to confine engineering to design
and management offices. Engineers must be will-
ing and encouraged to go "where the action is."
There is a prevalent tendency, even within the
profession, to downgrade the work of the engi-
neer in the field. The "hard hat and leather
booted" engineer is often referred to with some
trace of contempt by his colleagues at the design
level. Nevertheless, it is the field engineer who
is called upon to correct design errors during the
construction, and when a plant goes on stream
easily, it is largely due to the efforts of the "hard
hat and leather boot" engineers. It is, in fact,
a common practice to revise drawings after con-
struction to get an "as built" design.
If we wish to continue to promote engineering
as the profession which practices "the art of
utilizing the sciences in the production of ma-
chines and materials for the benefit of mankind,"
then I would like to make the following sugges-
1. Re-evaluate our engineering curriculum
with the goal of restoring to it the basic engi-
neering courses. Much of the new material added
to the curriculum as new courses, could be incor-
porated into existing courses.
2. Take a second look at the requirement that
20% of the engineering curriculum be devoted
to the humanities.
If we do not wish to continue with the image
of the engineer as the man known for his accom-
plishments, then we should accept the fact that
the present trend is leading the engineering pro-
fession into a field of activity, not directly con-

nected with what has been traditionally the do-
main of the engineer. In the normal course of
this development, engineering will become a
branch of science. There is already an increasing
use of the term "engineering science." I asume
that the term refers to what was once called
applied science. It will also lead into what may
be called applied mathematics.
Some well-trained technicians are already
pushing the engineer out of contact with actual
construction and production. Their argument is
that because of the professional engineer's
broader knowledge of the field, he should confine
his talents to those of overall management.
What they are implying is that because of the
time spent in broadening his knowledge, he is
no longer sufficiently well acquainted with the
details of the work to provide adequate super-
vision at the working level. There is considerable
merit to this point of view.
Assuming that the present trend toward
higher academic achievement for the professional
engineer will continue, then there will be an un-
avoidable gap between the engineer and the super-
vision of engineering at the working level.
Schools offering technical training are rapidly
upgrading their courses and it is possible that
such schools will, in the future, be called on to
provide engineering technicians adequately
trained to supervise the work previously super-
vised by engineers.
My personal preference, for a number of
reasons, would be to return to the professional
institutions the concept of practical application
of the knowledge of the sciences to the field of

Professor Ralph H. Wing is a graduate of Ohio State
University. His early teaching experience was at Pratt
Institute, Brooklyn, N.Y. Recent teaching experience was
at the West Virginia Institute of Technology where he
was head of the department of Chemical Engineering.
His engineering experience includes work with M.W.
Kellogg Co. and Ford, Bacon and Davis, of New York
and the Research and Engineering Division of the U.S.
Army Chemical Corps. His operating experience includes
work with Heyden Chemical Corps. at Danville, Pa. and
Fords, N.J. and Dodge and Olcott at Bayonne, N.J. He
is the author of a number of papers dealing principally
with plant operating problems.


M I book reviews

Readers and others are invited to sub-
mit reviews of books of interest to the
profession. Teachers are especially en-
couraged to write reviews of current text-
books they have tested in the classroom.

Non-Newtonian Flow and Heat Transfer
A.H.P. Skelland
John Wiley and Sons, New York (1967)
pp. vii + 469, 112 illustrations, $17.95
Many fluids involved in today processing
are non-Newtonian. For this area of study, Pro-
fessor Skelland has provided the student engineer
and the practicing engineer a text that is both
detailed and lucid. To accomplish this he has
excluded much of the mathematically complex
and often obscure developments of rheology, and
has included a wealth of practical examples. For
the teaching of engineering methods and to the
practicing engineer, who because of his age and
the newness of the field managed to escape a
depth of treatment, this book can be recom-
mended. It was not written with the intent of
being a text for advanced graduate research
orientated courses, for these there are several
books available; e.g. Frederickson, Lodge, or
A breakdown of the coverage is of interest.
After introductory sections on classification of
fluid behavior and experimental determination of
flow properties, the author deals with the me-
chanics of steady flow in tubes; of this, about
one third is on turbulent flow. Steady flow in
annuli, parallel plates, and rectangular ducts are
all briefly treated. The remaining half of the
book covers optimization of non-Newtonian pipe
systems, boundary layers, mixing and agitation,
and heat transfer. The balance appears to be
satisfactory considering the engineering nature
of the text and the state of the literature in the
There are areas of interest to researchers
that Skelland has avoided. Some may criticize
him for this, but I feel he has done well to avoid
them. With a cutoff time of early 1966 he could

not include the very recent ideas on the second
normal stress difference and drag reduction.
Even today, such topics as these and the rela-
tions of viscoelasticity and thioxtropic behavior
are still far from completely understood. I fail
to see how one could write a universally satisfac-
tory discussion of these factors, let alone how to
account for the observed effects in engineering
design. Much more work will have to appear in
the literature before these topics can be ade-
quately treated in an engineering text.
Finally, I should mention that this review
and the feeling expressed herein are based on the
use of the text for a quarter course at the ad-
vanced undergraduate level and introductory
graduate level. The book was used for the un-
dergraduates and master candidates who planned
to terminate at these levels. With these, I con-
sidered the use of the book totally successful.

Chemical Engineering Department
The Ohio State University
Columbus, Ohio

References from page 26

1. Burton, A. C., Physiology and Biophysics of the
Circulation, Year Book Medical Publishers, Inc., Chicago,
2. Roughton, F. J. W., Prog. in Biophys. and Biophys.
Chem. 9, 55, 1959.
3. Brian, P. L. T., J. E. Vivian, and A. G. Habib,
A.I.Ch.E. Journal 8, 205, 1962.
4. Wittenberg, J., Biol. Bull. 117, 402, 1959.
5. Scholander, P. F., Science 131, 585, 1960.
6. Keller, K. H. and S. K. Friedlander, J. Gen. Physiol.
49, 663, 1966.
7. Keller, K. H. and S. K. Friedlander, Chem. Eng.
Prog. Symp. Series 62, No. 66, 89, 1966.
8. Ward, W. J. and W. L. Robb, Science 156, 1481,
9. Keller, K. H. and S. K. Friedlander, J. Gen. Physiol.
49, 681, 1966.
10. Gordon, A. R., Ann. N.Y. Acad. Sci., 66, 285, 1945.
11. Katchalsky, A. and P. F. Curran, Non-Equilibrium
Thermodynamics in Biophysics, Harvard University Press,
Cambridge, 1965.
12. Singh, A., "The Experimental Determination of
Thermal Conductivity in Stationary and Flowing Blood,"
M.S. Thesis, University of Minnesota, 1966.
13. Galletti, P. M. and G. A. Brecher, Heart-Lung
Bypass, Grune and Stratton, New York, 1962.

WINTER, 1968

problems for teachers

The following problems were prepared
by Professor Octave Levenspiel with the
help of Professors Tom Fitzgerald and
Ralph Peck all of Illinois Institute of Tech-
nology. Attempted solutions are to be sent
to Professor Levenspiel at IIT who will
choose one solution for publication in the
next issue and list the names of others who
obtained the right answers. CHEMICAL
ages readers to send in home problems
and examination problems (with solutions,
please) to Professor Levenspiel or to the
Editor. We are also soliciting questions
on subjects of general engineering or
scientific interest to be presented to our
readers for their solution or discussion.

1. Squeezable but incompressible Bubbles la
Rue is happily floating in her kidneyish backyard
swimming pool when Alfred the Mean sneaks up
and pushes her under. Thermodynamically speak-
ing how does his ungallant action affect her en-
ergy and entropy?

2. Find the pressure at the base of a column
of water 4000 miles high located at the North
Pole. Assume liquid in the pipe is incompressible
with a density, p = 1.00 gm/cm3.

3. At present there are various opinions in the
literature concerning the nature of osmotic pres-
sure and how to treat it. For example in the life
sciences it is often talked of in terms of "negative
pressures." The references in Science 158, 1210
(1967) will lead you to some of these remarkable
papers. Do you want to contribute to the discus-
sions? Imagine what you could do by combining
it with the ideal gas law! If you can solve the
problem below and come up with a length of pipe
not more than 5 miles then you are ready for
such interdisciplinary exchanges. But you may
have other things to say. Who knows-try the
Problem: When a solvent and a dilute solu-
tion are separated by a membrane permeable
only to the solvent then the pressure difference

needed to maintain equilibrium is given approxi-
mately by
AP = Psolution - Psolvent Csolute RT
Here Ap is called the osmotic pressure. As an
example, for fresh water and sea water (roughly
3.5% solids, mostly NaCI) the osmotic pressure
is about 22 atm.
Suppose a long continuous tube filled with
fresh water and fitted with an ideal semiperme-
able membrane at the bottom is lowered deeper
and deeper into the ocean. Because salt water
is more dense than fresh water a depth will be
reached where the pressure difference across the
membrane will become 22 atm. (higher on the
If the tube is lowered further the pressure
difference will exceed 22 atm. in which case water
should flow through the membrane into the pipe
and fresh water can be recovered at the surface
of the ocean.
Assuming that the densities of fresh and salt
water remain at 1.00 and 1.03 gms/cm3 through-
out, how deep into the ocean must the pipe extend
so that fresh water can be recovered?

4. Here is a design optimization problem based
directly on thermodynamics. Somehow this type
of problem rarely pops up in thermodynamics
Problem: A company claims to have devel-
oped an ideal semipermeable membrane for the
desalinization of sea water. How should we oper-
ate a continuous flow pilot plant having just one
pump and no turbine so as to minimize the en-
ergy requirement to produce fresh water?

5. Sea level air at 80� F and 70% relative hu-
midity passes over a range of mountains about
12,000 ft high.
a. At what level will clouds form?
b. What is the temperature of the air pass-
ing over the range?
c. If all condensed moisture is removed as
rain before the air descends, what is the
temperature and humidity of air at sea
level in the lee of the mountain range?
Does this phenomenon explain the type of cli-
mate found directly west of the Sierras, the Cas-
cades and Mt. Whitney?


J I E1


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2100 Pennsylvania Avenue, North West
SWashington, D. C. 20037
Dear Mr. Collins,
Please send me an ASEE application blank
I would like to join the Chemical Engineering
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Department of Chemical Engineering
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WINTER, 1968


The large and vigorous body of chemical engi-
neering educators in our universities are generat-
ing a valuable literature of techniques and skills
in research and teaching, much of which up to
now has not had a medium of publication. The
Board of Publications of the Chemical Engineer-
ing Division of ASEE has ensured the future and
growth of this literature in chemical engineering

C. F. Braun and Company
The Dow Chemical Company
E. I. duPont de Nemours and Company
The Fluor Company
Mallinckrodt Chemical Works
Marathon Oil Company
Monsanto Company
Olin Mathieson Chemical Corporation

With grateful appreciation we list the chemi-
cal engineering departments which have sent or
have indicated that they will send financial sup-

University of Alberta
University of Akron
Arizona State University
University of Arkansas
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University of Cincinnati
City College of New York
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Colorado School of Mines
Columbia University
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University of Iowa
Iowa State University
University of Kansas
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Lehigh University
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McMaster University

education by enlisting the financial support of
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TION staff and readers express their gratitude
to the following companies who have contributed
to the initial financial support of this journal:

The Procter and Gamble Company
Standard Oil Company of California
Standard Oil Company of Ohio
Standard Oil (Indiana) Foundation
The Stauffer Chemical Company
The Sun Oil Company
Union Oil Company of California


University of Massachusetts
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University of Michigan
Michigan State University
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University of New Brunswick
Ohio State University
Ohio University
University of Pennsylvania
University of Pittsburgh
Polytechnic Institute of Brooklyn
Queen's University
Rensselaer Polytechnic Institute
University of Rochester
University of South Carolina
University of Texas
Tufts University
University of Virginia
Virginia Polytechnic Institute
University of Washington
University of Waterloo
University of Wisconsin
Yale University


rir rui; '

PROVING GROUND. "Sunoco Special" wins 1966 Canadian
Grand Prix, Bahamas Cup INassau Speed Weeki 1967 Uniled
Sales Road Rac;ng Charrpionsnip runner-up in 1966 Cana- '
dian-American Cnaltenge Cup series. Compeiiion ol Sunoco-
sponsored cars in malor racing events serves as a daring
provng ground lor Sunoco produces.

MONSTER. G;ant buckelwheel excavalor, earih-ealing monster Ihal
mines Ihe Athabasca oil sands for Sun Oil's lamed Great Canadian
Oil Sands Lid. prolecl in Alberla-a pioneering elfort in extending
Ihe world's petroleum resources.

GEOPHYSICAL FOUNTAIN. Plume of water from
seismic shot typifies Sun Oil Company's search
for oil and gas through geophysical surveys in
coastal waters of North America, the North Sea.
the Persian Gull and Venezuela.

Projects such as these, plus a $50 million mod-
ernization of the Toledo Refinery, a proposed
new $125 million processing plant in Puerto
Rico-all mark Sun Oil Company as a company
on the move.
Now a billion-dollar-a-year company. Sun Oil
is geared for growth. We need action people for
now\ and for the future. If projects like these
challenge you we'd like to talk.
\Ve have openings in Exploration, Produc-
tion, Manufacturing, Research, Engineering,
Marketing. Locations in Philadelphia, Toledo,
and Dallas areas.

�%-" : a. . rl


* t

P. � ;
'. *

2 ..

-rji ' ; �
t" . :I


Write for "Career Opportu-
nities at Sun," see your col-
lege placement director, or
write to Sun Oil Company,
Personnel and College Rela-
tions Dept. C, 1608 Walnut
Street, Philadelphia, Pa.
19103 for an appointment.
An Equal Opportunity Employer m/f


n ineers

grow with the growing world of Sohio

We need talented people immediately to work on important projects in:
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Sohio is-a progressive company whose growth is based on continuous research,
development and marketing of products for transportation, industry, agriculture
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on your technical talent to help us grow, and we offer rapid advancement to those
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WRITE SOHIO TODAY! Join the Sohio team... where you can get ahead fast
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An Equal Opportunity Employer (M&F)