Chemical engineering education

http://cee.che.ufl.edu/ ( Journal Site )
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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
Place of Publication:
Storrs, Conn
Publication Date:
Frequency:
quarterly[1962-]
annual[ former 1960-1961]
quarterly
regular

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Subjects / Keywords:
Chemical engineering -- Study and teaching -- Periodicals   ( lcsh )
Genre:
periodical   ( marcgt )
serial   ( sobekcm )

Notes

Citation/Reference:
Chemical abstracts
Additional Physical Form:
Also issued online.
Dates or Sequential Designation:
1960-June 1964 ; v. 1, no. 1 (Oct. 1965)-
Numbering Peculiarities:
Publication suspended briefly: issue designated v. 1, no. 4 (June 1966) published Nov. 1967.
General Note:
Title from cover.
General Note:
Place of publication varies: Rochester, N.Y., 1965-1967; Gainesville, Fla., 1968-

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Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
oclc - 01151209
lccn - 70013732
issn - 0009-2479
Classification:
lcc - TP165 .C18
ddc - 660/.2/071
System ID:
AA00000383:00059

Full Text





chemical engn eio












ACKNOWLEDGMENTS


Industrial Sponsor: The following company donated funds for the
support of CHEMICAL ENGINEERING EDUCATION during 1977-78.

3M COMPANY

Departmental Sponsors: The following 135 departments contributed
to the support of CHEMICAL ENGINEERING EDUCATION in 1978.


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Chemical Engineering Department, University of Florida, Gainesville, Florida
32611.












EDITORIAL AND BUSINESS ADDRESS
Department of Chemical Engineering
University of Florida
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Chemical Engineering Education
VOLUME XII NUMBER 3 SUMMER 1978



FEATURES

108 Superheated Liquids: A Laboratory Curiosity and
Possibly an Industrial Curse: Part II Industrial
Vapor Exposions R. C. Reid

DEPARTMENTS

98 The Educator
Don Woods of McMaster
102 Department of Chemical Engineering
Carnegie-Mellon
118 International
Training and Gas Engineering at the Algerian Pe-
troleum Institute E. I. Shaheen and D. V. Kniebes
136 Classroom
Chemical Engineering and Modular Instruction: A
Status Report K. C. Cohen. J. Alonso and E. J. Henley
Laboratory
112 Diffusion hnd Surface Reaction in Heterogeneous
Catalysis A. Baiker and R. Richarz
116 The Traveling Circus as a Means of Introducing
Practical Hardware lD. R. Woods, R. W. Dunn, J. J.
Newton and D. J. Webster
122 Two Experiments for Estimating Free Convection and
Radiation Heat Transfer Coefficients M. Econofmides
and J. O. Maloney
130 On the Application of Simple (Experiments to the
Teaching of ChE Themodynamics K. M. McNeil
140 Simple and Rapid Method of Determining the Vapor
Pressures of Liquids by Gas Chromatography B. Gilot
and R. Guiraud
107 Division Activities

101-143-144 Book Reviews

129 Letters

135-144 ChE News


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, University of Florida. Second-class
postage is paid at Gainesville, Florida, and at DeLeon Springs, Florida. Correspondence
regarding editorial matter, circulation and changes of address should be addressed
to the Editor at Gainesville, Florida 32611. 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., P. O. Box 877,
DeLeon Springs, Florida 32028. Subscription rate U.S., Canada, and Mexico is $10 per
year, $7 per year mailed to members of AIChE and of the ChE Division of ASEE.
Bulk subscription rates to ChE faculty on request Write for prices on individual
back copies. Copyright 1978 Chemical Engineering Division of American Society
for Engineering Education, Ray Fahien, Editor. The statements and opinions
expressed in this periodical are those of the writers and not necessarily those of the
ChE Division of the ASEE which body assumes no responsibility for them. Defective
copies replaced if notified within 120 days.
The International Organization for Standardization has assigned the code US ISSN
0009-2479 for the identification of this periodical.


SUMMER 1978









educator


of McMaster




PREPARED BY
C. M. CROWE
McMaster University
Hamilton, Ontario, Canada L8S 4L7


DON WOODS HAS RECENTLY graduated in
chemical engineering-for the second time!
Explaining why Don, a Professor of Chemical En-
gineering, attended undergraduate courses in
chemical engineering for four years will highlight
what makes Don such an unusual and stimulating
teacher and colleague.
This all began in 1974 when several of us ex-
pressed concern about whether we were really
doing a good enough job of teaching our students
how to solve problems. Stimulated by this chal-
lenge, and aided by a grant for teaching relief,
Don initiated a program to find out how our stu-
dents now solve problems, what skills they are
taught and ultimately how to help them develop
their skills.
He led a group of volunteer ChE students
through four years of weekly workshops and dis-
cussions-attending their classes, exploring many
different approaches and stimulating the students
to select and develop their own preferred tech-
niques. The students who undertook this program
have clearly become very adept at solving engi-
neering problems and at analysing their own


Don organizes what he calls a
"traveling circus" of chemical process hardware.
This consists of a collection of pieces of equipment
associated with a particular unit operation.
The students have two weeks to find out
what each piece is called, what it is
used for and how it works.


The Woods family relaxing at home with Cynthia, re-
corder; Russell, organ; Suzi, melodica; Don, banjo-uke
and wife Diane, guitar.


methods of attack. They were very impressive in
running a workshop on problem solving for sec-
ond year physics students. We have also seen the
effectiveness of this program in comparing stu-
dents who worked with Don to those who did not.
In addition to trying to break down the process
of solving a problem into steps (Define, Think
About It, Plan, Do It, and Look Back) Don has
tried to encourage creative thinking. An example
which the current graduating students recount
with relish was a brainstorming session on how
to crack seeds.
Words and phrases, outlandish or not, were
recorded and the craziest was used to generate
ideas for the process. The word "No", which arose
in response to Don's invitation to share a student's
private joke, was chosen. This led one student to
"Yes-No" which suggested a reciprocating me-
chanical device. Another student thought of
"Nein" which suggested numbers and a sequential
staged operation. A third student took "NON"
and was Jled to a rotary drum (the "0" with
blades) fed by a belt (the right "N") and crushed
and collected in a hopper (the left "N").
The objective of such sessions is not to achieve
detailed or even feasible processes but to liberate
thinking from conventional patterns so that un-
usual proposals may arise.
The result of Don's problem solving program
will result, we hope, in a manual which we can all
use in our own courses. An added benefit is that
we have, through Don, a unique view of our entire
undergraduate program, from the receiving end


CHEMICAL ENGINEERING EDUCATION









but with the eye of experience. This should be most
valuable in future curriculum revisions.

BACKGROUND

D ON IS A PRODUCT of a small town in eastern
Ontario, where his father's hardware store
stimulated his interest in working with his hands.
His house in Waterdown, a nearby town, has been
largely remodeled by Don and his wife Diane, and
decorated with his paintings and her weaving.
Don graduated from Queen's University,
Kingston in 1957 and then went to Wisconsin to
study with Warren Stewart. After his Ph.D. in
1961, he went to Britain on a two-year Athlone
Fellowship to study and work with three different
chemical process industries. These two years in-
volved several case studies which Don has since
used in his teaching. In 1964, we were very fortu-
nate to attract Don to join our department and the
wisdom of our choice has since been continually
reconfirmed.
While Don has taught several different courses
over the years, there are two which he pioneered
and which demonstrate his concern that students
learn not only the conventional ChE science but
also skills which are essential to a practising en-
gineer, although peripheral to the classical aca-
demic core.
The first is a second year course on Informa-
tion Management, an important subject but one
which is not everyone's first choice to teach. While


Senior undergraduate students, Suzanne Norman and
Sue Tyne discuss how to solve a problem with Don
Woods.


all of us worry about our students' ability to com-
municate, Don saw the problem in the wider con-
text of handling, storing and transmitting infor-
mation. The students learn how to search for in-
formation in the library including a few obscure
sources that were even unfamiliar to some of the
librarians.
Technical report writing, important and much
criticized as it is, is also a major component of this



In his fourth-year course on Process
Design and Cost Estimation, he initiated the
trouble-shooting problems. These are drawn from his
and others practical experience and each student is
required to diagnose a problem by asking questions.
The penalty for each question depends on the
estimated cost of obtaining the answer. This has been
so exciting for the students that our graduates
frequently send in new examples from
their industrial experience.


course. According to Don's plan, topics are offered
to students which both interest the faculty member
and should stimulate the student's excitement
about ChE. Much effort is devoted to advising a
student during the writing and to constructively
criticizing the finished report. We all share Don's
enthusiasm that the effort is worthwhile.
He originated the television taping of two stu-
dent speeches and the private playback with each
student alone with the instructor. This used to be
done on a 20-ft screen, which exaggerated each
student's shortcomings so much that we now use
normal-sized monitors. The assurance which this
develops in our students is evident in their oral
presentations of design projects in following years
and in their critical comments about some speak-
ers at ChE conferences. It is a tribute to Don's
original concept that this course is run on the same
model even when Don is not involved.
In his fourth-year course on Process Design
and Cost Estimation, he initiated the trouble-
shooting problems. These are drawn from his and
others' practical experience and each student is
required to diagnose a problem by asking ques-
tions. The penalty for each question depends on
the estimated cost of obtaining the answer. This
has been so exciting for students that our gradu-
ates frequently send in new examples from their
industrial experience.
As a preparation for the job market, the stu-
dents in that class had to apply for a job with one


SUMMER 1978









of several fictional companies in different fields of
chemical operations. Don designed letterheads for
each company and treated each application as a
real employer would. Subsequently the problem
assignments given to the students were related to
the company they had joined. In fact, one problem
was a real question about tar distillation drawn
from a local firm.
Don also gave every student experience in the
stock market by giving each one an (imaginary)
credit of $20,000 at the beginning of the year and
allowing them to buy and sell stocks through
orders placed in his mailbox. The market report
was eagerly sought every morning and at the end
of the course, the students' remaining assets
varied from $18,000 to $22,000.

METHOD OF TEACHING

DON ORGANIZES WHAT HE calls a "travel-
ling circus" of chemical process hardware.
This consists of a collection of pieces of equipment
associated with a particular unit operation. The
students have two weeks to find out what each
piece is called, what it is used for and how it
works.
In order to teach senior students about plant
layout, Don has used a piping layout model as a
laboratory project. The students are required to
locate the piping, valves and pumps so as to con-
form to practical requirements.
In his approach to teaching, Don has explored,
more than most of us, the voluminous literature on
the psychology of learning, and on teaching
methodology. He is open to any new and different
ideas and is eager to try them out with his stu-
dents.
He is also a showman, especially with overhead
transparencies. He always uses two projectors, so
that the previous slide is still visible while he dis-
cusses the current one. He makes liberal use of
overlays to allow the story to unfold gradually.
His experience in painting contributes to his use
of colors for highlights and to his amusing draw-
ings.


He originated the television taping of
two student speeches and the private playback
with each student alone with the instructor.... It is
a tribute to Don's original concept that
this course is run 'on the same model
even when Don is not involved.


His showmanship also comes to the fore at the
annual welcoming party for new graduate stu-
dents. He always leads the singing while playing
his banjo-ukulele and students newly arrived from
abroad are persuaded to join in "She'll be coming'


Don initiated a program to find out how our
students now solve problems, what skills they are
taught and ultimately how to help them develop their
skills.... He led a group of volunteer ChE students
through four years of weekly workshops and
discussions-attending their classes, exploring many
different approaches and stimulating the students to
select and develop their own preferred techniques.


Round the Mountain When She Comes' with all
the appropriate noises and gestures.
Another quality which distinguishes Don from
many of the rest of us is his extraordinary ability
to organize masses of detail. This is seen in his
massive collection of cost data for various types of
process equipment, which he has been publishing
as a series in the Can. J. Chem. Eng. He has also
compiled an excellent set of course notes on sur-
face chemistry in an attempt to bridge the gap
between the different approaches of chemists and
engineers. This activity has been noted widely, as
shown by an invitation to present a course on
surface chemistry with John Berg of the Univer-
sity of Washington at the ASEE Summer School
in Snowmass, Colorado in 1977. Don also was in-
vited to contribute to a course on cost estimation
to the AIChE local section in Odessa, Texas. He is
much in demand for courses and seminars in these
and his other areas of interest and experience.
In his research, Don selected the field of two-
phase liquid phenomena including mechanical sep-
aration and coalescence, as his main interest. He
and his students have done some fascinating work,
particularly in techniques for producing clean
interfaces between two liquids and in filming the
Newton's rings during the coalescence of a rising
droplet with a liquid layer of the same substance.

DIVERSITY OF INTERESTS
THE DIVERSITY OF DON'S interests and of
his publications is impressive, even overwhelm-
ing. He has produced books on Communication,
Putting Chemistry to Work, Problem Solving,
Surface Chemistry, and the Use of the Library
through McMaster's Printing Dept. He was one of


CHEMICAL ENGINEERING EDUCATION









six co-authors of "Chemical Plant Simulation" and
wrote "Financial Decision Making in the Process
Industry", which has been well received. When he
and his family went to the Netherlands on sab-
batical leave a few years ago, he and his wife
were concerned at the quality of first readers avail-
able in English. They produced a charming book,
"L is for Lucky", with their own illustrations,
which was a hit with their children.
For the Canadian centennial year of 1967,
Don grew a beard (which was not then a common
occurrence) and edited, with his wife and four
others, a history of Waterdown and East Flam-
borough-his home township. He is and has been
active in numerous community activities as a
leader in Cub Scouts, as a founder and director of
the Waterdown and East Flamborough Heritage
Society, as a Sunday school teacher and in various
other church activities and as member and chair-
man of the Flamborough Committee of Adjust-
ment (to decide on permits for building and
alterations).
We asked the 1978 graduating students for


their evaluation of Don, since many of them had
worked and studied with him for four years on
the problem-solving project. Their response, put
together by Stevan Cosic from talk during a camp-
ing weekend, emphasized Don's enthusiasm for
sharing his past industrial and educational ex-
periences-both good and bad. They cited his
continual efforts to achieve maximum participa-
tion of the class such as when he puts a problem
on the screen, then goes to the rear of the room
and sits down. According to the students, Don
makes learning fun and he manages to make the
students confident that they can solve their prob-
lems on their own.
It is difficult to describe in words what Don
Woods is and how he teaches. Those who have not
been fortunate enough to see him in action will,
we hope, have found here some idea of his many
qualities. Those who have met him may have found
here some new facets of his character. At Mc-
Master University, we count ourselves very fortu-
nate indeed to have Don Woods as a ChE col-
league. O


book reviews

SMOKE, DUST AND HAZE: FUNDAMENTALS
OF AEROSOL BEHAVIOR
By S. K. Friedlander, Wiley Interscience, 1977.
317 pp. $16.95.
Reviewed by Benjamin Y. H. Liu,
University of Minnesota.
This book, by a well-known author in the field
of aerosol science, provides a much-needed text on
the subject of aerosol behavior. The word
"aerosol," according to contemporary scientific
usage, refers to a system of particles, either solid
or liquid, suspended in a gas. "Smoke, dust and
haze," consequently, are all specific examples of
aerosols.
The book is divided into eleven chapters, with
Chapters 1 through 5 covering the fundamental
aerosol properties, including the basic transport
and light scattering properties, size distribution
functions and particle deposition by convective
diffusion and inertial impaction. Chapter 6, on
experimental methods, provides a concise but ade-
quate description of the modern aerosol genera-
tion, measuring, sampling, and analysis tech-
niques. Chapters 7 through 11 deal with the


general dynamic processes of coagulation, nuclea-
tion, gas-to-particle conversion, and source-
ambient relationships for particulate air pollu-
tants. Problems at the end of each chapter pro-
vide the needed exercise for students. The refer-
ences given, though not extensive, are well-chosen.
They provide a convenient source for further
literature studies on the respective topics.
One of the outstanding features of the book
is its clarity of presentation. The topics are de-
veloped clearly and rigorously from an elemen-
tary to an advanced level. Mathematical methods
are used to make the theoretical development
rigorous, but reference to the actual physical pro-
cess taking place makes the meaning of the mathe-
matical development clear. The chapter on Colli-
sion and Coagulation is particularly well-done, re-
flecting the author's own original contribution to
the field.
Interest in aerosols has mushroomed in the
last few years. Many specialized treatises and
books have appeared, but none has dealt with the
subject in a sufficiently comprehensive manner
to be used as an introductory text. Smoke, Dust
and Haze will provide such an introductory text.
It is suitable for the engineering curriculum at the
advanced undergraduate or beginning graduate
level. It should also serve as a valuable reference
book for those working in the field. O


SUMMER 1978






























An aerial photo showing Carnegie-Mellon University and


aS .department




CARNEGIE MELLON


DENNIS C. PRIEVE
Carnegie-Mellon University
Pittsburgh, Pennsylvania 15213

N JUNE OF 1974, I was headed for Pittsburgh
to attend a national AIChE meeting. On my
only previous trip, I flew to Pittsburgh at night
to interview for a position as Assistant Professor
with the Department of Chemical Engineering at
Carnegie-Mellon University (CMU). But this was
my first trip by car and I did some exploring. I
found that the absence of any regular pattern of
streets and the scarcity of signs made driving in
Pittsburgh an adventure. The hills of the city
create such a turmoil in the network of roads that
Fifth Avenue intersects Sixth Avenue.
Once I found it, Carnegie-Mellon's 100-acre
campus turned out to be remarkably spacious for
an urban university with only 4500 students and
450 faculty. That commodious feeling is enhanced
by neighboring Schenley Park whose 500 acres in-


clude hiking trails, a golf course, tennis courts and
a skating rink. On the academic side, I was
pleasantly surprised to discover an outstanding
College of Fine Arts here. Drama has been quite
successful, with two student productions-"God-
spell" and "Pippin"-becoming well known on
Broadway. Other major strengths of Carnegie-
Mellon University are the Graduate School of In-
dustrial Administration (GSIA), the Computer
Science Program, and the Engineering College.
All are nationally recognized. Herb Toor, a former
Head of Chemical Engineering, ably leads the
Engineering College as its current Dean.
GSIA gained its reputation by emphasizing the
use of modern mathematics, behavior sciences, and
orderly analytical problem-solving in managerial
decision-making. President Richard M. Cyert, a
former dean of GSIA, has successfully applied
these concepts to transform the University's fi-
nancial state into one of fiscal health: the Univer-
sity is run without deficits. In this era of a nation-


CHEMICAL ENGINEERING EDUCATION









wide decline in college enrollments, it is important
for a university to have good fiscal management.

GENERAL ATMOSPHERE
B UT I BECAME MOST enthusiastic about that
segment of the university with which I am
most familiar: the Department of Chemical Engi-
neering. It is a dynamic place, with continuous and
productive activity. Such activity is possible both
because of superior people, and because of good
relations among the faculty and between faculty
and students.
Tom Fort, as Head of the Department, de-
serves much of the credit for generating and main-
taining that atmosphere. In spite of many time-
consuming administrative chores, he maintains an
open-door policy in his relations with both faculty
and students: he will listen to any and all prob-
lems. Knowing the talents of each of the faculty,
Tom applies his administrative influence to help
each of us to make the most of our talent. Finally,
the Department is run in a democratic manner:
each of the faculty is polled before a decision is
made on a matter of substance. Such policies per-
mit good relations among faculty and promote
productivity.
Good relations are also enhanced by the Friday
happy-hours organized by the graduate students.
The proceeds from a soft-drink machine operated
by the students are used to buy beer which is then
made available, free, to all. These well-attended
weekly events are held in the department's gradu-
ate student lounge (ignored by the University)
which contains a pool table, a fooze-ball table, a
TV-Pong game, and the daily New York Times, all
obtained from vending machine proceeds.


Prof. Cussler answered a knock at the
door of his office only to be greeted by a
shaving cream pie in the face, which was prepared
by a group of students to celebrate his birthday.


Besides the formal weekly departmentalsem-
inars at which researchers from outside the Uni-
versity are invited to speak, several internal sem-
inar programs have been organized. One of these
is the biweekly "zoo meeting," in which graduate
students and postdoctoral researchers in the pro-
grams directed by Ed Cussler or Fennell Evans
get together to discuss recent findings. On alter-
nate weeks, another informal seminar meets. The


latter program, organized by John Anderson, in-
volves more than half the faculty in the Depart-
ment and their graduate students as well as a few
from other departments. Topics generally pertain
to interfacial phenomena or preparation and be-


Simultaneous collisions in many-body systems are possible. This photo
records one such event in which all the faculty of the ChE Department
were recently found in the same place at the same time. Seated (left
to right): Kun Li, Bob Rothfus, Tom Fort, Steve Rosen, and Ed Cussler.
Standing are Gary Powers, Rosemary Frollini, Clarence Miller, Ethel
Casassa, John Zondlo, Dennis Prieve, Fennell Evans, Eric Suuberg, Tony
Dent, Mike Massey, John Anderson, Howard Gerhart, and Art Wester-
berg.

havior of hydrosols. Some of the talks are reviews
or tutorials, but the main purpose of these sem-
inars is to convey freshly obtained information
and to gather criticism regarding the proposed
interpretation. A third group, organized by Art
Westerberg and Gary Powers, meets regularly to
discuss problems related to computer-aided design.
These informal seminars provide a means for
broadening perspectives on problems which are in-
completely solved. The resulting interplay of ideas
has a synergistic effect, causing the total research
output of the Department to be greater than the
sum of contributions possible from isolated in-
dividuals.
It is, sir, as I have said,
a small college, and yet
there are those who love it.
Daniel Webster
(1818)
All Souls College, Oxford, planned
better than it knew when it limited
the number of its undergraduates to
four; four is exactly the right
number for any college which is
really intent on getting results.
Albert Jay Nock
(1943)


SUMMER 1978








While these words were written about other
schools, they echo a sentiment which has always
been held at Carnegie-Mellon University. Although
a university must be large enough to accommodate
the diversity of its students' interests, it should
remain small enough to be personal. Close personal
relations between faculty and students have ex-
isted since the beginning, as illustrated in the fol-
lowing recollections by Mr. Frederick L. Koethen,
who enrolled in the first class at (then) Carnegie
Tech in 1905:
After things at Tech had become organized, Director
and Mrs. Hamerschlag took a trip to Europe. We knew
about this trip and, when we learned they were due back
in Pittsburgh,, some of the boys went to the station, re-
moved the two horses from an open passenger rig, and
attached two ropes to the vehicle. A crowd of students
provided ample motor power for a triumphal tour of
Oakland. It was a sincere expression of the respect and
admiration they had for their leader. They did not have a
mass meeting to build up enthusiasm for the stunt. It was
not necessary.
Dr. Herbert F. Sills was frequently late to give his
chemistry lectures at one o'clock. We finally told him that
the next time he was late, we were going to the baseball
game. It was a temptation to us because Forbes Field was
very close. It was new and the Pirates in the National
League were playing championship ball. The next time he
was late came very soon. We were walking over the
Panther Hollow bridge toward Forbes Field when we met
Dr. Sills. We told him to turn around, which he did, then
bought his own ticket and enjoyed the game with us. That
was not the approved way to "run a railroad" or any other
organization but the later lectures of Dr. Sills did seem to
come across better, being given by a friend.
Since that first class of 200 students in 1905,
enrollment at CMU has climbed to the current
4500. Now the Department of Chemical Engineer-
ing alone has more undergraduates (a total of
about 300) than the entire school had in Mr.
Koethen's time. There are also 80 full-time and 45
part-time graduate students, together with seven
postdoctoral fellows.

PERSONAL TOUCH CONTINUES
YET THE PERSONAL touch has not been for-
gotten. Episodes like those quoted above still
occur. For example, last year Kun Li and Steve
Rosen each taught one section of a course entitled



Another recent educational development
in the Department is the New Alternatives
Program, which was designed to give master's-level
training in ChE to technically oriented students
whose bachelor's degree is not in ChE


Director and Mrs. Hamerschlag are welcomed back from an European
trip (1905) by students who pulled their carriage on a tour through
Oakland as a stunt.


"Analysis, Synthesis, and Evaluation," which is
required of all engineering sophomores and em-
phasizes creative engineering. One part of the
course involved a project on how to make use of
the rubber in worn-out automobile tires. One
morning, near the end of that part of the course,
Profs. Li and Rosen each found awards for their
efforts outside their office doors. They were halves
of a worn-out tire, cut diagonally, each of which
bore an inscription. Kun's read
Good year, Dr. Li,
We're tired of your course,
We shed a tear* for the souls next year.
while Steve's said
Don't tread on us, Dr. Rosen,
We never promised you a Rosen garden,
Spare us.
The students had come up with a solution to the
problem that had never occurred to their teachers.
On another occasion, Ed Cussler returned to
his office to find a large part of it occupied by a
fully inflated weather balloon. Then there was the
time when Prof. Cussler answered a knock at the
door of his office only to be greeted by a shaving-
cream pie in the face, which was prepared by a
group of graduate students to celebrate his birth-
day. Considerable speculation followed about what
would have happened if a visiting professor, who
was in the office at the time, had answered the
door instead.
To cope with the increasing numbers of stu-

*An allusion to University Professor Dick Teare, who
also taught part of the course.


CHEMICAL ENGINEERING EDUCATION








dents, we have increased the number of faculty
members by three since I arrived, and have broken
core courses into multiple sections. However, none
of the lecture or recitation sections is taught by a
graduate student. One of the new faculty members
is John Zondlo, who is a full-time instructor in
charge of the three undergraduate lab courses.
Prof. Zondlo takes care of the daily operation of
the lab, including a total refurbishment of the
facilities during last summer, daily maintenance
of the equipment, and setting up the schedule of
experiments. The rest of the faculty equally share
the responsibility of explaining experiments to
students, deciding on any modifications to existing
apparatus, and grading the lab reports, with about
two or three experiments assigned to each faculty
member.
An educational development, which occurred
here several years ago, was the organization of the
Colloids, Polymers, and Surfaces Program (CPS).
It grew out of an expression of need by local in-
dustries for graduate-level training of some of

An educational development, which
occurred here several years ago, was the organization
of the Colloids, Polymers, and Surfaces
Program (CPS).

their employees in these specialized areas. Since
there were several faculty members here who had
research interests in these subjects, Fennell Evans
took on the task of organizing a joint program
with the Chemistry Department which leads to a
nonthesis Master's degree in CPS. Besides a core
of lecture courses, students are required to com-
plete eight credits of a special laboratory course
taught by Ethel Casassa. Students get individual
instruction on a variety of research-oriented in-
struments. All these instruments are also available
to other students in chemistry or chemical engi-
neering who may need them for their thesis re-
search. While the CPS program was designed for
students who hold full-time jobs in local industry,
a number of regular graduate students have
elected either some of the lecture courses or a
joint ChE-CPS Master's degree, which requires a
thesis
Because of the interest and favorable reaction
from industry, plans are underway to teach some
of the material in the CPS program to under-
graduates in ChE. Fundamentals of colloids, poly-
mers and surfaces will be taught in new lecture
courses with applications to conventional unit op-


rations such as polymer processing and solid/
liquid separations. Again, a laboratory course will
be included in the curriculum to illustrate the
principles.
Another recent educational development in the
Department is the New Alternatives Program,
which was designed to give master's-level training
in ChE to technically oriented students whose
bachelor's degree is not in ChE. Students in the
program are given an intensive course during the
summer, complete with laboratory experiments,
which covers undergraduate ChE principles. Upon
successful completion of the summer program,
they are admitted to the regular master's degree
program, where they compete with other ChE
students in both courses and the comprehensive
written exam given to all graduate students. De-
tails of this program have been previously pub-
lished (CEE 11, 176 (1977)).

DEPARTMENTAL RESEARCH

A LL FACULTY IN the Department are actively
involved in research. Topics are generally re-
lated to energy, biochemical engineering, colloids,
polymers, surfaces, or computer-aided design.
Some of the projects involve the development of
large-scale equipment, such as the coal-gasification
work by Mike Massey or the development of heat
exchangers for the ocean-thermal energy conver-
sion (OTEC) plant by Bob Rothfus. Both of these
industrial-scale projects involve a number of


Ethel Casassa, giving instructions to students in the CPS lab on the
technique for operating a pressure-filter to remove dust from solutions
used in light-scattering experiments.


SUMMER 1978











These informal seminars provide a means for broadening perspectives on
problems which are incompletely solved. The resulting interplay of ideas has
a synerqistic effect, causing the total research output of the department to be
greater than the sum of contributions possible from isolated individuals.


faculty from several departments. Eric Suuberg
also conducts energy-related research in coal
pyrolysis.

Clarence Miller and Tom Fort are currently studying
systems where surfactants lower interfacial tensions be-
tween oil and water. One major application is in tertiary
oil-recovery, where surfactant flooding is used to increase
the amount of oil obtained from wells. Prof. Miller is also
interested in spreading of liquids on rough surfaces and
other interfacial phenomena. Gas adsorption and surface
chemistry are also of interest to Prof. Miller and, sep-
arately, to Tony Dent, whose research focuses on hetero-
geneous catalysis. Other studies of kinetics of gas-solid
reactions are preformed by Kun Li, who worked for a
local steel manufacturer before joining CMU. As a result,
his particular subject is iron-ore reduction, where he has
some fascinating electronmicrographs showing reduced-
iron whiskers growing out of the oxide. Why, ihe asks,
does reduction occur in this manner?
Kun Li and Bob Rothfus also have an interest in fine
particle technology. Their most recent joint venture was
to study the coagulation of iron-oxide particles in water
by the addition of alum. Thus, Prof. Li provides a link
between the gas/solid interface people and the liquid/solid
interface people.
John Anderson's research concerns hindered diffusion
of hydrosols and macromolecules in pores, together with
electrokinetic effects which result from the charge on all
solid/aqueous interfaces. Examples of hydrosols (a phase
which is finely dispersed in water) include latex paints,
waste-water sludge, milk and most other foodstuffs, as
well as blood cells and globular proteins. Prof. Anderson's
work overlaps with mine, which is the transport of hy-
drosols. Because of their finite size and electrostatic
charge, colloidal particles behave differently from mole-
cular solutes. I am currently applying my approach to the
deposition of latex films on steel surfaces. On the other
hand, Prof. Anderson's work is applicable to the transport
of large solutes through porous membranes as well as the
catalyzed reaction of macromolecules in liquid-filled pores.
Additional studies on transport of molecular or ionic
solutes through biological membranes are conducted by
Ed Cussler and Fennell Evans. They attempt to explain
such anamolous behavior as transport of a solute in the
direction of increasing concentration, or transport at a
rate which is nonlinearily related to the difference in con-
contration across the membrane. Prof. Cussler is also con-
cerned with solubilization kinetics and the psychophysics
of texture-that is, relating what people perceive as the
feel of foods to chemical and physical properties. He likes
to introduce the latter subject as the "Funny Feelies"
(maybe that's why some people jokingly call him Crazy
Ed).


Fennell Evans is also involved with surfactants, with
applications to detergency. He recently developed a sur-
factant-selective electrode for measuring the concentration
of free surfactant molecules in the presence of aggregates
of surfactant molecules known as micelles. This and other
work on the behavior 'of electrolytes complements much
of the research here on aqueous systems.
Both John Anderson and I use latex polymers as sols
in our work. The mechanism for synthesizing these sols
by emulsion polymerization is one of the topics of Steve
Rosen's research. He is also developing an in situ poly-
merization process for stabilizing soil on which emergency
shelters could be built and is studying ways to separate
polymer mixtures in order to recycle the huge masses of
petroleum-based polymers which are discarded as solid
municipal wastes. A third project, in cooperation with
Tom Fort, focuses on improved interfacial bonding in
polymer-based composites.

As a Vice President of PPG Industries,
Howard Gerhart was instrumental in the incep-
tion of the CPS program. After retiring from
PPG in 1974, Dr. Gerhart joined CMU and or-
ganized the National Coatings Center (NCC). As
a branch of Carnegie-Mellon Institute of Research
(CMIR), NCC provides a national focus for both
fundamental and applied research related to coat-
ings and corrosion. Besides a full-time staff of
postdoctoral researchers, who cooperate with fac-
ulty in chemistry and ChE, the NCC has access to
the analystical-instrument resources of CMIR,
the present counterpart of the pre-merger Mellon
Institute. Dr. Gerhart and I have cooperated in
several projects, including the electrophoretic and
chemiphoretic (electroless) deposition of latex
films on metal surfaces, and the sacrificial protec-
tion of steel against corrosion. At the NCC, Dr.
Gerhart has also succeeded in developing a new
polymeric material with a high refractive index
for optical use.
Much of the research described above lies on
an interface between ChE and some other dis-
cipline (often chemistry). However, Gary Powers
and Art Westerberg are studying the use of the
computer in the very traditional area of chemical
process design. They cooperate, through the De-
sign Research Center (DRC), with people in all
the other engineering departments on campus, as
Continued on page 135.


CHEMICAL ENGINEERING EDUCATION


I











CHEMICAL ENGINEERING

DIVISION ACTIVITIES


SIXTEENTH ANNUAL LECTURESHIP AWARD TO
THEODORE VERMEULEN
The 1978 ASEE Chemical Engineering Di-
vision Lecturer was Theodore Vermeulen of the
University of California at Berkeley. The purpose
of this award lecture is to recognize and encour-
age outstanding achievement in an important field
of fundamental chemical engineering theory or
practice. The 3M Company provides the financial
support for this annual lecture award.
Bestowed annually upon a distinguished engi-
neering educator who delivers the Annual Lec-
ture of the Chemical Engineering Division, the
award consists of $1,000 and an engraved certifi-
cate. These were presented to this year's Lecturer
at the Annual Chemical Engineering Division
banquet, held at the University of British Colum-
bia on June 20, 1978. Dr. Vermeulen spoke on
"Dynamics of Runaway Systems".
RECENT PREVIOUS LECTURES
1970 Joe M. Smith, University of California at Davis,
"Photochemical Processing-Photo-Decomposition of
Pollutants in Water"
1971 William R. Schowalter, Princeton University, "The
Art and Science of Rhoeology"
1972 Dale F. Rudd, University of Wisconsin, "Synthesis
and Analysis in Engineering"
1973 Rutherford Aris, University of Minnesota, "Dif-
fusion and Reaction in Porous Catalysts-a Chem-
ical Engineering Symphony'
1974 Elmer L. Gaden, Jr., Columbia University, "Bio-
technology-an Old Solution to a New Problem."
1975 John M. Prausnitz, University of California at
Berkeley, "Molecular Thermodynamics for Chem-
ical Process Design"
1976 Abraham E. Dukler, University of Houston, "The
Role of Waves in Two-Phase Flow: Some New
Understandings"
1977 Robert C. Reid, Massachusetts Institute of Tech-
nology, "Superheated Liquids: A Laboratory Curios-
ity and An Industrial Curse"
Ted Vermeulen, born in Los Angeles, completed his
B.S. and M.S. in chemical engineering at CalTech and
later a Ph.D. in physical chemistry at UCLA. He did
catalytic process research for Union Oil Company for two
years, and later worked six years in process development
and research planning for Shell Development Company.
He then joined the University of California at Berkeley,
serving as founding chairman for chemical engineering
from 1947 to 1953. He has been a Fulbright Professor at
SUMMER 1978


Liege and Ghent in Belgium, and at the French Petroleum
Institute; a Guggenheim Fellow for research at Cambridge
University; and a visiting lecturer at Syracuse and Notre
Dame Universities, and the National University of Mexico.
Vermeulen's research has been aimed at strengthening
the ties between engineering science and engineering prac-
tice, and has centered on the combined action of chemical
kinetics and transport effects in multiphase systems. In
the kinetics area, he has worked on non-isothermal-reactor
calculation methods, multireaction analysis, homogeneous
catalysis, polymerization, and combustion. In the separa-
tions area, he has contributed to a unified design theory
for adsorption and ion exchange, and also to liquid-liquid
extraction design based on both axial dispersion and
multiphase agitation. Currently he is applying these col-
lective interests to research on the liquefaction and de-
sulfurization of coal.
He serves as co-editor of "Advances in Chemical En-
gineering." He is a Fellow of AIChE, has chaired the
Northern California Section and has been a member of
national committees. He received the William H. Walker
Award in 1971.

OTHER CHEM.E.'S RECEIVE AWARDS
Several other chemical engineers were re-
cipients of special awards and recognition at the
recent ASEE Annual Conference in Vancouver.
Those so honored are as follows:
C. JUDSON KING, professor and Chairman
of ChE at the University of California, Berkeley,
received ithe 33rd annual George Westinghouse
Award. Sponsored by the Westinghouse Educa-
tion Foundation, the award is designed to en-
courage young educators who show evidence of
excellence and innovation in engineering teach-
ing.
The 22nd Curtis W. McGraw Award for out-
standing early achievements by a young engineer-
ing college researcher was presented to GERALD
L. KULCINSKI, professor of nuclear engineering
and associate director of the Wisconsin Fusion
Technology Program at the University of Wis-
consin, Madison. ASEE's Engineering Research
Council, with the McGraw-Hill Book Company,
sponsors this award.
ROBERT P. MORGAN will receive the Ches-
ter F. Carlson Award for Innovation in Engineer-
ing Education. He is a professor and chairman of
Continued on page 121.










1977 4wacid .Letuae


SUPERHEATED LIQUIDS

A LABORATORY CURIOSITY AND, POSSIBLY,

AN INDUSTRIAL CURSE


Part 2: Industrial Vapor Explosions


ROBERT C. REID
Massachusetts Institute of Technology
Cambridge, Massachusetts 02139

VAPOR EXPLOSIONS-A REVIEW

IN PART 1, WE EMPHASIZED the concept of
a superheated liquid and the fact that there is
a superheat-limit temperature (SLT). Kinetic
theory described, approximately, the rates and
probabilities of vapor formation in superheated
liquids-while thermodynamics placed an upper
value on the SLT. We saw that experimental meas-
urements of the superheat-limit temperature were
in good agreement with predictions from kinetic
theory and, correctly, less than limiting values
estimated from thermodynamics.
Nevertheless, the experiments were carried out
under laboratory conditions with great care taken
to minimize heterogeneous nucleation. Only a very
small fraction of all bubble-column tests are suc-
cessful wherein a drop is indeed heated to the SLT.
Most drops begin to vaporize before this limit is
attained.
Can we, therefore, ever expect, in real world
operations to superheat a liquid sufficiently high to
induce true homogeneous nucleation where there
is very rapid (even explosive) formation of va-
por? We examine a number of case histories-
drawn from research studies or plant accidents.
In all instances, two liquids come into contact;
one is significantly more volatile and at a lower
initial temperature than the other. Modes of con-
tact vary greatly and as will be suggested, the type
of contact may be very important in determining
the outcome.

MOLTEN TITANIUM-WATER VAPOR EXPLOSIONS

THROUGH THE KINDNESS of Dr. Robert A.
Beall I have been allowed access to a number of


unpublished accident reports, several of which
have recently been declassified. These deal with
water-molten metal explosions in the cold-mold
arc-melting and casting process. In this industrial
operation, large ingots of titanium, zirconium,
tantalum, columbium, molybdenum, tungsten, al-
loyed steels, etc., are prepared. To minimize con-
tamination, crucibles are constructed of copper
and kept cool by an external water jacket. The
metal to be cast is prepared as a consumable elec-
trode by compressing and welding "sponge" metal
into a vertical cylinder. A high amperage-high
voltage arc causes melting. (See Figure 12)


CONTROL GEAR
VACUUM SEAL-
TO VACUUM
PUMP


LOWERING ROD


SUBSIDIARY
WATER JACKET



WATER OUT




WATER IN


WATER JACKET
FOR CRUCIBLE


FIGURE 12 DIAGRAM OFTITANIUM MELTING FURNACE

CHEMICAL ENGINEERING EDUCATION









A review of this process is available in a Bu-
reau of Mines report (Beall et al., 1968).
In the past twenty-five years, a number of
accidents have been reported. Essentially, all have
resulted when, for various reasons, there was a
failure of the copper mold with subsequent contact
between molten metal and water. Fortunately,
most led only to mild steam explosions, but a few
were very different. These, in a Spockian sense
were "most interesting," but in a humanoid view
make for depressing reading.
As an example, quoting from a letter from Dr.
Beall, "In one case, a hole was burned in the cruci-
ble, water intruded, and the arc was extinguished.
Interlocks on this particular furnace called for the
electrode to be drawn up (out of the water). How-
ever, the limit switches on the withdrawal mechan-


We turn next to accidents which occur all too
frequently in paper pulping operations.... Severe
explosions have occurred in the step where the molten
salt (smelt) from the furnace is dissolved in water.


ism failed to function, and when the electrode
reached the top of the furnace, the cable broke,
and the electrode fell, driving the water standing
in the crucible into the molten pool of metal. A
very severe explosion resulted, scattering furnace
components like shrapnel."
With a good deal of insight, Dr. Beall con-
cludes "Of important consideration is the fact
that water leaks in arc furnaces of this type have
occurred occasionally in the various melting es-
tablishments without any serious explosion result-
ing therefrom. In a few reported instances, steam
buildups have been noted but not of serious conse-
quence. It must be pointed out that the affair here
reported required the coincidental occurrence of a
water injection, intimate mixing with molten
metal, and very possibly, tamping of the mixture
by the falling electrode. Such a chain of circum-
stances can lead to a powerful explosion rather
than the customary quiet extinguishing of the
arc."
We cannot conclude with any certainty that
explosions in cold-mold arc-melting furnaces are
due to superheated liquid water. It does appear to
us, however, that it is less than coincidental that
two elements appear necessary to achieve an ex-
plosion: molten metal contacts water, and there is
some impact event, i.e., the falling of a heavy elec-
trode into the metal-water, the shock-wave due to


Weight
.. Trip
T,,p

N Reinforc.d
2 T
Concrete Wall
'* r -tr Thickl w

11
Top Hc.l ---
_j _____ * __


FIGURE 13 SKETCH OF DEVICE FOR INDUCING
EXPLOSIONS WHEN DUMPING HOT
ALUMINUM INTO WATER.
FROM LONG, 1957.
failure of a rupture disc, etc. It is easy to hypothe-
size-but more difficult to prove-that the impact
event forced water and metal into intimate contact
for a brief period to develop a highly superheated
water layer that nucleated violently and efficiently
mixed the metal-water together to enhance rapid
steam (or hydrogen) production on a large scale.

MATTE-WATER EXPLOSIONS

A NEW DIMENSION was introduced to me by
letter from Roland S. Young of Victoria, B. C.
who told of several harrowing experiences when
molten matte contacted water. In fact, he indicates
that the problem is so serious that before trans-
ferring molten matte with cast iron ladles, the
ladles must first be dried over an open fire to in-
sure no moisture is present. He writes, "I recall a
distressing incident in a large copper-cobalt
smelter in Northern Rhodesia. Here too, careful
attention was given to the drying of matte ladles,
but on this occasion a small leak in the roof must
have allowed water from a tropical downpour to
fall unobserved into a ladle. The resulting ex-
plosion ejected matte 40 feet into the air, killing
the craneman in his cab. Can you offer an explana-
tion for the high activity of metallic sulphides,
when molten, with water?"
Unfortunately, I have no firm answer for Mr.
Young. Molten metallic sulfides appear to be par-


.... vapor explosions can also occur when
cryogenic liquids contact water..... in two instances,
vapor explosions resulted when liquified natural gas
(LNG) spilled upon a water surface.


SUMMER 1978









ticularly sensitive when contacted with water.

MOLTEN ALUMINUM-WATER EXPLOSIONS

EXPLOSIONS RESULTING from the contact
between molten aluminum and water are often
most impressive as documented by two research
teams at Alcoa Research Laboratories (Long,
1957; Hess and Brondyke, 1969). Most tests con-
sisted of tapping a molten aluminum crucible
suspended above a small water tank (see Figure
13). Although the water containers were con-
structed of 3/16 to 1/4 inch welded steel plate (or
were concrete), an explosion was readily detected
since, as noted by Long, "all but the mildest ...
broke the steel water containers ... and frequently
hurled pieces several hundred feet."
The salient results show that below some min-
imum flow rate of metal, no explosions resulted.
Also, a long fall through air reduced explosions as
did deep water depth. Apparently, some molten
metal had to reach the container bottom to obtain
an explosion; any modification which fragmented
the falling molten aluminum or allowed it to
solidify before touching the bottom would reduce
or eliminate explosions. Organic coatings or grease
on the bottom of the water vessel were effective
in eliminating explosions. The severity of the in-
teraction was also reduced by dissolving oils or
wetting agents in the water or by increasing the
lateral dimensions (for the same quantity of
aluminum poured-usually 22.6 kg).
On the other hand, the explosions became more
violent if the water contained dissolved salt or if
there were lime, rust, or gypsum coatings on the
bottom (the condition of the sides was of little
importance).
The negative effect of the hydrophobic coatings


3500 I
3000


2500 H


2000


1500


1000
500 iiii i
o '
0 200 400 600 800 1000 1200
ALUMINUM TEMPERATURE, C
Temperature Dependence of the
Peak Pressure Resulting from Wter
Impact Upon Aluminum,
From Wright and Humberstone, 196
FIGURE 14


certainly suggests that the initiating step occurs
on the bottom of the water container between
(still) molten aluminum and water. Superheating
a thin water film could form the initiating steps,
but recent experiments by Briggs (Board and
Caldarola, 1977) have shown that when molten



We examine a number of case
histories-drawn from research studies
or plant accidents. In all instances, two liquids
come into contact; one is significantly more volatile
and at a lower initial temperature than the other.


aluminum is poured into a tank of water, a coarse
dispersion (-1 cm scale) is formed in the lower
half of the tank. The vapor explosion seems to be
initiated at the base of the tank and propagates at
a velocity of about 200 m/s. Clearly, additional
research is warranted.
As opposed to these studies, simply contacting
the surface of a molten aluminum pool with water
leads to little but film boiling. However, Wright
and Humberstone (1966) impacted water on a 6
mm-deep molten pool of aluminum in a vacuum;
the impact pressure was estimated as about 14 bar
(200 psi). A violent disruption occurred and the
highest observed pressure was about 200 bar
(2900 psi). This pressure was achieved in about
40 pfs after contact and decayed in about 3 ms.
Figure 14 shows low peak pressures were obtained
when the aluminum was below the melting point
but they increased with temperatures above
6500C. In another test, the impact of water on
molten aluminum saturated the pressure trans-
ducer at 5800 psi.

SMELT-WATER EXPLOSIONS
SE TURN NEXT TO accidents which occur
all too frequently in paper pulping opera-
tions. In the "Kraft" process, wood chips are "di-
gested" with a cooking liquor consisting primarily
of sodium sulfide, caustic soda and sodium car-
bonate. Hydrolysis of the lignins occurs. The
spent cooking solution (black liquor) is concen-
trated in evaporators, salt cake (sodium sulfate)
is added and the strong solution fed to a furnace.
Organic compounds burn, much of the sodium sul-
fate is reduced to sodium sulfide and the molten
salt residue is discharged and dissolved in water
to form "green liquor".
Severe explosions have occurred in the step


CHEMICAL ENGINEERING EDUCATION









where the molten salt (smelt) from the furnace is
dissolved in water. At this stage, the principal
salts are sodium carbonate and sodium sulfide with
lesser amounts of other sodium (and potassium)
salts; the furnace discharge temperature varies
from about 870-10500C. Other explosions have
resulted when the water-tube wall of the furnace
failed and leaks developed.
Studies over the past 10 years have attempted
to clarify the mechanism of these smelt-water ex-
plosions. Although several theories are now avail-
able, there still remain a host of unanswered
questions.
Let us review briefly some of the experimental
research results which seem most relevant; these
have been abstracted primarily from a report by
Battelle-Columbus (Krause et al., 1973) and
from development studies at Combustion Engi-
neering (Nelson and Kennedy, 1951, 1956). In
these studies, small quantities of water (or green
liquor) were injected into a pool of smelt held in
a cone and heated by an induction furnace.
The smelt composition was found to be crit-
ically important in establishing whether an ex-
plosion is probable. Pure molten Na2CO, could
never be made to explode when contacted with
water. Addition 'of Na2S (or NaCI, NaOH, etc.)
sensitized the smelt and led to a higher likelihood
of explosion (Sallack, 1955). Also, use of green
liquor (water with dissolved Na2COS and NaS)
led to more frequent (and more violent) explo-
sions. Time lags after injection, before an explo-
sion, were in the order of 2 ms. Higher injection
velocities also increased the probability of an ex-
plosion and extended the temperature range of the
smelt over which explosions occurred. This latter
fact is quite interesting. For example, with a
70% Na2CO3 30% Na2S smelt, the maximum
temperature of the smelt leading to an explosion
was about 850C with a water injection pressure
of 6.9 bar but increased to 925C when the injec-
tion pressure was raised to 10.3 bar. One must
conclude that the mode of contacting is also an
important variable in these cases. Finally, very


hot water (>65C) led to almost no explosions
irrespective of smelt composition.
Most studies have discounted any significant
effects of chemical reaction in the explosion
mechanism. It seems clear that some physical
initiating step is required to cause intense frag-
mentation of the water (and smelt?) to produce
very large volumes of steam in a short time scale.
Superheating of thin films of water with subse-
quent homogeneous nucleation has been proposed
by Nelson (1972) and not rejected by Krause et al.
(1973). In some manner, there is assumed to be
local liquid-liquid contact between the smelt and
water for a brief period of time. A thin film of
water superheats (theoretical limit ,- 300C)
SOLENOID
somo--


FIGURE 15 IMPACT APPARATUS
and nucleates. This generates local, but very
strong, pressure and shock waves. These both
fragment the water and smelt in the near vicinity,
but may also cause collapse of other vapor films
separating water and smelt to produce secondary
superheat explosions, and these, in turn, etc.
Does this mechanism agree with the experi-
mental facts? In most instances, yes, but there
remain critical experiments to be done.
Molten sodium carbonate will not explode with
water; presumably there is CO2 generated at the
boundary and this inhibits liquid-liquid contact.
Sodium sulfide sensitizes the .smelt. Why should
this molten salt enhance liquid-liquid contact?
There is a definite time lag, after injection, before
Continued on page 127.


... I have been allowed access to a number of unpublished accident
reports.... These deal with water-molten metal explosions in the cold-mold arc-melting and
casting process. ... Fortunately, most led only to mild steam explosions, but a few were very different. These,
in a Spockian sense were "most interesting", but in a humanoid view make for depressing reading.


SUMMER 1978










laboratory


DIFFUSION AND SURFACE REACTION

IN HETEROGENEOUS CATALYSIS


A. BAKER and
W. RICHARZ
Swiss Federal Institute of Technology (ETH)
Zurich, Switzerland

THE INTERACTIONS between mass transfer
and chemical reaction in heterogeneous catal-
ysis are described in many textbooks on chemical
reaction engineering. However, few laboratory ex-
periments are known that permit the student to
apply his theoretical knowledge [1]. This is cer-
tainly due to the fact that it is difficult to find
suitable easy-to-handle heterogeneous reaction
systems. Furthermore, a rigorous quantitative de-
termination of the chemical reaction rate on the
catalyst surface is not possible in most cases since
boundary conditions that permit a solution of the
differential equations describing mass transfer are
too complicated.
Now, the ethylene hydrogenation on a platinum
catalyst, electrolytically applied to a tube wall,
proved to be a good system for the study of the
interactions between diffusion and surface reac-
tion in heterogeneous catalysis. Boundary condi-
tions are well defined and by varying the tempera-
ture from room temperature to 180C, the transi-
tion between surface reaction control and mass
transfer control can be well observed. Since the
differential mass balance can be integrated numer-
ically.for this laminar flow system, an exact value
of the surface reaction rate constant may be ob-
tained.
In a previous publication [2], some aspects of
the 4th year ChE laboratory program at the Swiss
Federal Institute of Technology (ETH) have been
described. This experiment is part of that course
and has been developed in recent years in order to
combine transport phenomena and heterogeneous
catalysis and to bring at the same time the
FORSIM computer simulation program [3] into


ChE laboratory. Its application permits the stu-
dent to integrate the differential mass balance and
helps to take away some of the magic still asso-
ciated with partial differential equations.
In fact, the laminar flow system used has a
simple geometry (tube) so that the differential
mass balance is easily established and boundary
conditions can be precisely stated. After trans-
formation of the partial differential equations to
dimensionless form as described by Briuer [4],
the numerical integration by the FORSIM pro-
gram is straightforward and rapid.


Werner Richarz studied chemistry at the Swiss Federal Institute of
Technology (ETH) in Zurich, Switzerland (PhD, 1954) and is Associate
Professor for Chemical Engineering at ETH Zurich since 1972. Presently
he teaches Chemical Reaction Engineering for Chemical Engineers and
Heat and Mass Transfer for chemists. His research interests are in the
fundamentals of heterogeneous reactions (catalytic and non-catalytic) at
normal and high pressure and in reactor modelling. (R)
Alfons Balker studied Chemical Engineering at Swiss Federal In-
stitute of Technology (ETH) Zurich, where he received his Ph.D. degree
in 1974. His principal research interests are heterogeneous catalysis
and surface chemistry. Since 1975 he has been leading a research
group at ETH. Current research includes development of catalytic
amination processes, behaviour of non-stationary operated catalytic
reactors, diffusion in porous solids, catalyst preparation and character-
ization of catalyst structure. (L)


CHEMICAL ENGINEERING EDUCATION











... for some of their experiments
the students have to calculate axial
and radical concentration
profiles in the reactor.


Briuer [4] integrated equation (4) numerically
after transformation to dimensionless form by
introducing the numbers given in Table 1.
Thus equations (4) to (7) become:


1 af
p ap


af
-2 [1- p2J a 0 (8)
Zs


THEORETICAL BACKGROUND
T HAS BEEN SHOWN that the ethylene hy-
drogenation is 1st order with respect to ethylene
(gas mixture: 98 % H2, 2% C2H). Thus the global
reaction rate can be defined as:

rG =keffc (x) (1)
The average ethylene concentration at the exit of
the reactor is therefore:


c(L) = Coexp (-keff T)

The surface reaction rate is given by:


rs = -ksc (R,x)


The influence of diffusion can be seen by compar-
ing the global and surface reaction rates. How-
ever, for this comparison kef has to be multiplied
by VR/S. The surface reaction rate is determined
by integrating the differential mass balance over
the cross section and length of the reactor.

We assume that
* we have a constant volume reaction (in fact, E .02)
* the reaction is conducted isothermally
* the flow is steady-state and the laminar velocity profile
is fully developed
* axial diffusion is negligible as compared to the transport
by bulk flow.
Therefore we have the following mass balance:


D +2C _-1. r -2
ar2 r ar


1- ( 2)= 0

(4)


For the system described in Figure 1 the boundary
conditions are:


c(r,0) = Co (5)
ac(0,x) 0 (6)
Dr = 0 (6)
ar

D =c ksc (R,x) (7)
ar


f(p,0) = 1


af(0,e) 0
ap -


3P


The mean concentration f(0) at the exit of
the reactor is calculated by integrating f(p,0)
over the cross section:


p(1 -p2)f(p,0)dp
f(0) = (12)

p(1- p2)dp


The results of the numerical integration by the
FORSIM-program are given in Figure 2. For all
important parameters the programs default values


Le x-O
[- --- f -


x-L
Pt-catalyst I


Vx 2R
----r~ -
O x ( r)


FIGURE 1. Notations for the ethylene hydrogenation
system

can be used (Runge-Kutta-integration, eleven
spatial points, three-point difference formulae).
Equation (12) is integrated by the Simpson-
method. For the evaluation of the experimental



As a whole, this experiment
proved to be a very helpful tool for
a better understanding of the influence of
diffusion on heterogeneous chemical reactions.


SUMMER 1978


(10)


(11)









1.0
0.8
0


0'03 0 0
0.0

0.2

0.1
008
2.
002
m -- i- ; ;



0.01 1
0 0.2 0 0.6 08 10 12 1.4
e

FIGURE 2. c/Co as a function of Da and 0


use a GowMac 69-552. Column: Poropak s, length
1.7 m, inner diameter 0.005 m. Column tempera-
ture: 55C. Detector: HW. Analysis time: 4 min.
Reactor and piping are made of stainless steel.
The reactor tube is heated in an air bath and has
the following dimensions: inner diameter 0.02 m,
length 1.4 m. Gas temperature is measured before
and after the reaction zone with NiCr/Ni thermo-
elements enabling one to verify that the reaction
is conducted isothermally. The platinum catalyst
is not directly applied to the tube wall but to a
thin tubular nickel support consisting of two
separate halves, put together by means of two
O-rings (see Fig. 4).
After electrolysis, the support is put together
and introduced into the reactor. The catalyst zone
length is 0.1 m. If the zone is longer, the reaction


results i.e. the determination of the surface re-
action constant, the graph as given in Figure 2 is
most useful. The diffusion coefficients needed can
be estimated e.g. by the Wilke-Lee-method [5].

APPARATUS

A SCHEMATIC DIAGRAM of the experimental
system is given in Figure 3. It consists es-
sentially of two gas cylinders containing pure H2
and the premixed 98% H2/2% C2H, a gas meter-
ing valve, the thermostated reactor tube, a gas
meter and a gas chromatograph.
In our setup we use an automatic sampling
valve, but sample taking with a gas syringe is
equally good, only a bit more tiresome.
A simple gas chromatograph is sufficient; we


1 PURE HYDROGEN
2 GAS MIXTURE
3 METERING VALVE
4 AIR BATH
5 REACTOR TUBE


-- ~ 6 CATALYST ZONE
7 HEAT EXCHANGER
8 GAS CHROMATOGRAPH
I9 VALVE
10 GAS METER
3 I

I ) 8

-..... vent
10
7 9


FIGURE 3. Flow diagram of experimental reactor
system


O


O


FIGURE 4. Catalyst support


can not be conducted isothermally. The entrance
length is 1.2 m.

PROCEDURE

N ORDER TO HAVE high and constant activ-
ity, fresh catalyst is prepared for each series
of measurements (old catalyst is easily wiped off
the nickel support). For the electrolysis, each half
of the nickel support is treated separately in a 3 %
aqueous solution of H2 (Pt6Cl) -6H0O. At a current
of 0.4 A (750 A/m2) electrolysis time is 3 minutes.
The catalytic surface is then rinsed with distilled
water. The catalyst is introduced into the reactor
tube and heated to the highest desired temperature
in a pure hydrogen atmosphere in order to avoid
catalyst poisoning. At a given temperature, meas-
urements are made at several gas flow rates vary-


CHEMICAL ENGINEERING EDUCATION











... the ethylene hydrogenation on a platinum calalyst,
electrolytically applied to a tube wall, proved to be a good system for the
study of the interactions between diffusion and surface reaction in heterogeneous
catalysis.


ing from 0.001 to 0.006 m3/min. Steady state is
always quickly achieved (less than the time neces-
sary for product gas analysis). Usually the meas-
urements are carried out going from the lowest to
the highest temperature.

STUDENT PERFORMANCE

THIRTY HOURS LABORATORY TIME during
3 weeks are provided for this experiment. The
students usually need about a day for the theoret-
ical preparation of the experiment and to get
acquainted with the apparatus. Some difficulty
arises from the fact that a change of flow rate in
the reactor has to be made with valves 3 and 9
simultaneously in order to maintain the pressure
at a given value. The experiments should be run
in one day in order to have constant catalytic
activity. Invariably, good results are obtained.
Evaluation of the measurements are rapid, k,,f
is calculated from equation (2), ks is determined
from the Damk6hler group by means of the graph
given in Figure 2. Some typical results are given
in Figure 5.
In addition, for some of their experiments the
students have to calculate axial and radial concen-
tration profiles in the reactor by means of the
FORSIM-program. Previously we discuss the
physical situation with the students. Their un-
certainty clearly shows the need for this exercise.
As a whole, this experiment proved to be a very
helpful tool for a better understanding of the in-
fluence of diffusion on heterogeneous chemical
reactions.

TABLE 1. Dimensionless groups


DEFINITION

Da = ksR
D
DL
2-
R vx


SIGNIFICANCE

chemical reaction rate
diffusion rate
mean residence time
diffusion time from tube center to wall


r radius (variable)
P = R tube radius


c

SUMMER 1978
SUMMER 1978


* I f-
Ak.


.. .0


I I I I I
0.002 0.0025 0.003 0.0035
l/T, K-1
FIGURE 5. Arrhenius plot of reaction rate constants

ACKNOWLEDGMENT


T HE AUTHORS THANK THE
dent W. Caprez for his help in
experiment. O


graduate stu-
preparing the


NOMENCLATURE
c concentration, mole/m3
co initial concentration, mole/m3

c mean concentration, mole/m3
D diffusion coefficient, m2/s
Da Damkihler
keff effective reaction rate constant, s-1
kg surface reaction rate constant, m/s
L catalyst zone length, m
r radius (variable), m
R tube radius, m
rG global reaction rate, mole/m3-s
r, surface reaction rate, mole/m2.s
S catalyst surface, m2

vx mean flow rate, m/s
V, volume of catalyst zone, m3
E fractional volume change
T mean residence time, s
REFERENCES
1. J. B. Anderson, Chem. Eng. Ed. 1, 78 (1971) and
Chem. Eng. Ed. 2, 130 (1971).
2. J. Dunn, J. E. Prenosil, J. Ingham, Chem. Eng. Ed. 1,
23 (1976).
3. M. B. Carver, FORSIM: a Fortran-oriented Simulation
Package, Atomic Energy of Canada Limited report
AECL-4844 (1974).
4. W. Briuer, F. Getting, Chem. Ing. Techn. 38, 30
(1966).
5. C. R. Wilke and C. Y. Lee, Ind. Eng. Chem. 47, 1253
(1955).


concentration (variable)
concentration at reactor entrance


- -2











Ij classroom


THE TRAVELING CIRCUS AS A MEANS OF


INTRODUCING PRACTICAL HARDWARE


DONALD R. WOODS, ROBERT W. DUNN,
JOSEPH J. NEWTON AND
DONALD J. WEBSTER
McMaster University
Hamilton, Ontario, Canada


AT THE AICHE NEW YORK Meeting, 1967,
Dr. Charles Littlejohn of Clemson described a
procedure for introducing his students to hard-
ware. He had a sectioned display box and each
week he put some piece of hardware into each
pigeon hole and asked his students to familiarize
themselves with each during the week.
We, at McMaster, found this idea to be attrac-
tive and have used it since then to complement
our fourth (and to a limited extent our third)
year's activity. The particular hardware about
which we feel all engineers should have some
knowledge is shown in Table 1. The mechanics of
the approach follows. About every two weeks we
display some of the hardware given in Table 1
in one of the fume hoods in our laboratory. About
20 items are displayed at a time. Each item is
numbered as in Table 1 and each student is given
a copy of Table 1. A slide-tape show providing
details of some of the hardware is available in a
nearby resource center. The students are expected
to handle the hardware, take it apart, and to-
gether with the help of the slide tape show and
selected books !1-4] to give themselves 'a working
knowledge of the specifications, the principles of
operation and the application of each piece of
hardware. At the end of each two week period
the students' knowledge is tested.
Some example questions are:
*For the pitot probe, draw a diagram and clearly identify
the parts. Two pressures are measured; show the loca-
tion of the leads from these two measurements and
indicate which pressure is the higher. Differentiate
between a pitot probe and an impact probe. How would


A. Ir



Authors Bob Dunn, Joe Newton and Don Woods
(left to right) select items for the travelling circus.

Robert Dunn was Senior Technician at the Welsh College of
Advanced Technology, Cardiff, Wales, where he was part time lecturer
and technician. He has been Chief Technician in the Chemical Engi-
neering Department at McMaster University since 1965. His special
concerns are to develop laboratory experiments and experiences that
acquaint students with the practical side of engineering and provide
insight into the fundamental principles. He is an avid wilderness hiker,
fisherman and outdoorsman.
Joe Newton was "on the job" training instructor for adults during
World War II, then transferred to Craft apprentice basic workshop
instructing. He developed and implemented Basic Technician Training
courses and later was appointed Craft Apprentice Training Officer,
supervising all craft apprentice training at the Associated Electrical
Industries, Rugby, England. He has been technician in the Chemical
Engineering Department at McMaster University since 1968, assisting
in the design and production of research and undergraduate projects
and furthering the practical knowledge of students. He is a gardener,
a furniture maker and a keen model engineering enthusiast.
Don Woods worked in industry for two years before joining the
Department of Chemical Engineering in 1964. One of his teaching
responsibilities is process analysis and design. He has tried to integrate
practical knowhow into these courses. His other interests include
square dancing, community activities and home renovation.
Don Webster graduated from McMaster University in 1977. As part
of a course in communications skills, Don developed a slide-tape show
of the hardware associated with piping and pumps.


CHEMICAL ENGINEERING EDUCATION











TABLE 1
The Traveling Circus

TRANSPORTATION:

Valves: 1. gate; 2. globe; 3. ball; 4. butterfly;
5. diaphragm; 6. needle; 7. check; 8. back
pressure; 9. safety relief; 10. solenoid;
11. pneumatic; 12. control; 13. regulating.
Fittings: 14. nipple; 15. union; 16. bushing; 17. tee;
elbow (18. 900; 19. 450; 20. street); 21.
reducer; 22. cross; 23. male connector;
24. female connector; 25. swagelok
fittings for tubing.
Pumps: 26. centrifugal; 27. screw; 28. MoynoR;
29. magnetic; 30. vacuum; 31. recipro-
cating piston; 32. diaphragm.
MEASURING INSTRUMENTS:


Flow velocity:


Pressure:





Particles:


Shop:




Energy flow
Temperature:


33. pilot tube; 34. impact tube; 35. velo-
meter; 36. anemometer; 37. rotameter.
38. Bourdon pressure gauge; 39. com-
pound gauge; 40. McCloud gauge; 41.
pressure controller; 42. orifice plate; 43.
sonic orifice; 44. manometers (44. micro;
45. slant; 46. vertical).
47. coulter counter; 48; microscopic; 49.
Zeta meter.

50. dividers; 51. inside/out calipers; 52.
odd leggs (hermofrodites); 53. scriber;
54. square; 55. spirit level; 56. center
punch.
57. thermocouple; 58. heat flux meter;
59. potentiometer.


TOOLS AND CONNECTORS:


Wrenches:
Cutters:


Screw drivers:


Bolts:


60. open; 61. socket; 62. box.
63. tubing cutters; 64. hacksaw; 65. tin
snips.
66. Robertson; 67. Philips; 68. slot; 69.
files; 70. tube benders.
71. coach or carriage; 72. lag, machine;
(73. hex head; 74. allenhead; 75. flat
head); 76. stove bolt; 77. rawlugs or ex-
panders.


UNIT OPERATIONS:

Heat exchanger: 78. shell and tube; 79. bubble plate; 80.
sieve and 81. floater plate; 82. intallox
packing.
Steam traps: 83. strainer; 84. centrifix separator; 85.
bucket; 86. thermostatic; 87. ball; 88.
thermodynamics traps.
Miscellaneous: 89. rupture disc; 90. hydrocyclone.


you calculate the local velocity from the data output,
namely from the pressure differential? What correc-
tion factors would you make in your calculations or
what precautions would you take in the experimental
use of a pitot probe?
* For a pitot probe, how might one use a pitot probe or
the principles thereof to measure the gas velocity in
a dust laden stream?
* For valves, draw a diagram and clearly identify the
parts to distinguish between a globe, gate, butterfly,
needle and ball valve.
* If the "arrow" showing the direction of flow is not
marked on a globe valve, how would you tell which
way the flow should go through the valve?
* If one is pressure testing a system by spraying soap
solution on the joints and looking for bubbling, what
often overlooked part of a gate valve-pipe network is
likely to be the source of the leak?
* If a globe valve is to be used for the inlet and outlet
pipes to a batch vacuum receiver, why might the
globe valve be installed "backwards" on the inlet lines?
* For thermocouples, draw a diagram of a measuring
copper-constantan thermocouple system and clearly
identify the location of the potentiometer and all the
parts necessary to make the system work. Where
would you look up the "best" choice of materials to
use in a thermocouple to measure the following temper-
atures:
-1000C; 50C; 2000C; 500C; 800C; 10000C;
What criterion does one use in choosing a thermo-
couple? A colleague of yours plans to use boiling water
as the reference temperature. What do you think about
his idea?
* For fastners, draw a diagram of a machine bolt, stove
bolt, lag bolt, and carriage bolt that clearly differenti-
ates among this? In each of the foregoing, mark on the
distance that is meant when we identify a bolt as
3/8" x 3". If your girlfriend's Dad is building a wooden
deck, what type of bolt would you recommend he use
to fasten the 2 x 6 joists to the 4 x 4 posts?

This procedure relieves the necessity of spend-
ing classroom time discussing these features and
gives the students flexibility in becoming ac-
quainted with these hardware details. The ap-
proach is popular with the students and has been
nicknamed by them "the travelling circus" because
of the variety and changeability of the display. E



REFERENCES

1. Dean, R. C. Jr., Aerodynamics Measurements. Gas
Turbine Laboratory, MIT., Cambridge (1953).
2. The Chemical Engineers' Handbook. Perry, R. H. and
Chilton, C. H., ed, 4th ed. McGraw-Hill Book Co.
(1973).
3. Liptak, B, ed. Instrument Engineers' Handbook Vol I:
Process Measurement. Chilton Book Co., Philadelphia
(1969).
4. Liptak, B. ed. Instrument Engineer's Handbook Vol II
Process Control. Chilton Book Co. Philadelphia (1970).


SUMMER 1978









MW international


TRAINING AND GAS ENGINEERING AT THE

ALGERIAN PETROLEUM INSTITUTE


E. I. SHAHEEN and D. V. KNIEBES
Institute of Gas Technology
Chicago, Illinois 60616

ALGERIA IS A LAND of beautiful nature lo-
cated on the Northern tip of Africa, it
stretches along the Mediterranean sea for 640
miles, where the sun-bathed beaches are among the
most beautiful in the world. It has large fertile
plains, beautiful mountains, and a desert rich with
oil, gas, and minerals. Many civilizations crossed
this magnificent land, and left a spectrum of im-
pacts; from the Romans, to the Arabs, Turks and
French. The Arabs left an everlasting effect of
Arabization. The Algerians fought courageously
for their independence, which they gained from
the French on July 5, 1962. In the defense of their
motherland, they lost nearly one and a half million
martyrs. Algeria is known nowadays as the "land
of the million shahid and millions of moujahidine".
Throughout Algeria massive industrialization
and development is taking place. Algerians have
called on technologists and top scientists and engi-
neers from across all political boundaries. This
breathtaking pace for development was luckily
blessed with oil and gas reserves which helped in
bringing about the necessary cash for taking such
gigantic steps. Thus, the creation of an Algerian
Petroleum Institute to fulfill the needs of the oil
and gas industry was a must.
Created November 29, 1965, the Algerian
Petroleum Institute expanded its mission of Feb-
ruary 28, 1973 and thus became the Algerian
Petroleum Institute of Gas, Chemistry, Petro-
Chemistry, Plastic Materials, and Motors. Or, as is
called in French, "Institut Alg6rien du P6trole",
abbreviation as IAP. It functions under the min-
istry of industry and energy, and works very
closely with the major and only oil company in
Algeria, namely SONATRACH (Societe Nationale
de Transport et de Commercialisation des Hydro-
carbures). In essence it is this oil company that
makes the cash available for IAP's operations.


The three major objectives of the Algerian In-
stitute of Petroleum are to provide: technician's
training, engineering education, scientific and
technical research.
The administration offices are mainly located
at Dar El-Beida near the airport, about twelve
miles from the city of Algiers. In this location, the
technical training of engineers in the short cycle
program takes place. This is a specialization for
graduate students who have degrees in physics,


Dr. Esber 1. Shaheen is Director of Education Services with the
Institute of Gas Technology (IGT) in Chicago. He is also Director of
International Education Programs with Gas Developments Corporation
(GDC), a wholly-owned subsidiary of IGT. Dr. Shaheen has experience
in both industry and the academic field, having taught at six different
universities. Dr. Shaheen received his BS from Oklahoma State Uni-
versity, his MS from the University of Arizona, and his PhD from the
University of Tennessee, all in chemical engineering. He is the author
of many articles and four books: "Environmental Pollution Awareness
and Control"; "Basic Practice of Chemical Engineering with Solutions
Manual"; "Energy/Pollution Illustrated Glossary"; and "Arabic-English
with a Petroleum Accent." He is listed in' American Men of Science
and in Outstanding Educators of America. (L)
Mr. Duane V. Kniebes, Assistant Vice President of Education and
Research Services; BS in chemistry, MS in physics. Joining IGT's staff
in 1949, Mr. Kniebes has served' as head of the Analytical Division
and as Director of Operations. His current administrative responsibil-
ities include chemical analysis, technical information, and educational
services, including management of specially-designed engineering and
technician education programs. (R)


- -.
*~
*- *-'


IAes k


CHEMICAL ENGINEERING EDUCATION


























Industrial and Educational boom in Algeria.


chemistry, and engineering and who wish to
specialize in the gas or oil disciplines. These stu-
dents normally spend a preparatory year and
another year for specialization.
The Ecole d'Ingenieurs at Boumerdes was
opened in 1971. Here, most of the students take a
normal engineering program, called the long cycle,
where they will study for nearly five years before
receiving their engineering degree. A special short
cycle lasting about a year and a half is given to
students in the specialty of gas transmission and
distribution.
Technical schools are located near industrial
centers. Thus, the specialized technicians while
gaining their industrial education become accus-
tomed to the industrial atmosphere. These centers
are at Hassi Messaoud, Oran-Es-Senia, Arzew,
Skikda, Annaba and Setif.
The students admitted to the technicians' pro-
gram have already finished the first or second bac-
calaureate which is approximately equivalent to
the high school diploma. These students study for
a year or two depending on the speciality involved.
At the end of their program, they become "tech-
nicians sup6rieurs". The various specialities for
technicians are: geology, geophysics, production,
refining, petro-chemistry, chemistry, gas and
plastics, regulation, mechanical drawing, and
safety. The general academic program includes
the revision of basic principles of mathematics,
physics and chemistry, and then some specific
theoretical courses in the technology of materials,
along with laboratory work, and a certain period
of work in a plant to gain industrial experience.


RESEARCH AND ENGINEERING
SCIENTIFIC RESEARCH and measurements
are made at Dar El-Beida's laboratories. This
type of work touches on the various branches of
the petroleum industry, and covers geology, geo-
physics, production, refining and petrochemistry.
Thus, in geology, IAP arranges missions to vari-
ous terrains for establishing geological charts and
geochemical works. In the production area, the re-
search is directed toward harnessing of petroleum.
It comprises the study of fluid flow in porous
media, the mechanics of reservoirs, and the stim-
ulus of reservoirs by chemical methods or through
fracturing. The laboratories in the area of refining
constitute distillation, chromatography, spectro-
photometry by atomic absorption and flame emis-
sion, and solvents extraction.
As previously mentioned, the two major engi-
neering programs offered at IAP are: short cycle
(cycle court) and the long cycle (cycle long). A
number of review courses are given in the short
cycle program. After that the students specialize
in any of these chosen disciplines:
* Petroleum Exploration, (Geology and Geophysics)
* Refinery and Petrochemistry
* Petroleum Production
* Motors and Applications
* Natural Gas.
Aside from the courses received at the institute,
some practical experience is gained by working in
the petroleum industry. For the short cycle the
duration of the practical experience lasts about
one month. Certain seminars are also given by
specialists who visit the institute from time to
time. This helps in rounding up the education
given to the students prior to their full engage-
ment in industrial work.
In the long cycle program, the first four years
are spent in formal education, where students take
the necessary courses along with various plant
visitations that may last from a few days to five
or six weeks. Each engineering student spends the
fifth year at a plant, for gaining practical experi-
ence. Certain remedial courses are given from time
to time. This is due to the temporary unavailabil-
ity of professors in a given line of specialty.


Algeria leads the world in
building two huge plants for the
liquefaction of natural gas: the Skikda plant
and the CAMAL plant at Arzew.


SUMMER 1978


I























Vacation in the countryside away from oil and the pressures of the job.

The detailed program for gas engineering,
which includes liquefied natural gas (LNG), and
gas transmission and distribution, will be dis-
!cussed to give the reader a good example of the
long cycle type academic program at IAP.

GAS ENGINEERING
ALGERIA LEADS THE WORLD in building
two huge plants for the liquefaction of nat-
ural gas: the Skikda plant, and the CAMEL plant
of Arzew.
With basic plans for earning hard currency
for industrialization, and a major goal for improv-
ing the standard of living, and bringing gas to all
sectors of industry and all residential areas, the
obvious need was for the development of LNG
operations, transmission and distribution of gas.
At IAP, the two major disciplines in the gas en-
gineering program are: liquefied natural gas
(LNG), and transmission and distribution. One
major objective of this program is to train engi-
neers for the natural gas industry of Algeria.
Graduates of the program are badly needed, and
jobs are waiting for them.
Currently, the long cycle discipline for liquefied
natural gas is being taught. However, the short
cycle was taught during the academic year 1973-
1974. The discussion here will deal with the long
cycle program because it will be used in the future.


Students choose their option after the second
academic year.
This program is being modified so that stu-
dents will receive instruction in the English
language rather than French. Students will be re-
ceiving about a 6-month intensive course in Eng-
lish prior to receiving their classical engineering
instruction.

TRANSMISSION AND DISTRIBUTION ENGINEERING

THE SHORT CYCLE program for Engineering
and Distribution Engineering is described here.
Its duration is nearly three semesters. It has been
especially designed to train competent engineers
for the SONELGAZ company (Soci6t6 Nationale
d'Electricit6 et de Gaz).
Although very few engineers come from the
Algerian Technical University (Ecole Nationale
Polytechnique d'Alger), most of the students are
chemists and physicists with B.S. degrees (license
es-sciences). They have a strong theoretical back-
ground, but are extremely lacking in applications.
Their laboratory experience is limited; and they
are totally unfamiliar with engineering and op-
erating practices.
These students have obtained the second bac-
calaureate (Baccalaureat Deuxieme Partie). The
second baccalaureate is essentially equivalent to
our first semester of the sophomore year. After
the second baccalaureate, and depending on per-
formance, these students attend a University. The
chemists and physicists take the first year in
common. In the first year, they will have mathe-
matics (integral, Taylor, matrices, differential
equations), chemistry (general, organic), and
physics (electronics, magnetism, optics). They do
not take physical chemistry. In order to graduate
with a B.S. from the university, the student must
earn six certificates in the following 2 or 3 years.
* Program for Chemists at the University:
In the second, third, and fourth years, the chemists will
take organic and general chemistry, thermodynamics,
mineral chemistry, physics, experimental physics, and
then may choose among the options of analytical chem-
istry, applied organic, applied mineral chemistry, or
biochemistry.


This breathtaking pace for development was
luckily blessed with gas and oil reserves which helped in bringing
about the necessary cash for taking such gigantic steps. Thus the creation of an Algerian Petroleum
Institute to fulfill the needs of the oil and gas industry was a must.


CHEMICAL ENGINEERING EDUCATION








* Physicists Program at the University:
The subjects studied by the physicists are as follows:
mathematical techniques of physics, triple integration,
differential equations, electricity, thermodynamics, optics,
and the general theory of mechanics (trajectories).
Finally they can choose among electronics, modern phys-
ics, fluid mechanics, and atmospheric physics.
A review of basic fundamentals is essential
prior to dwelling into the basic topics of gas trans-
mission and distribution. When a chemist or a
physicist is enrolled in such a program, and the
majority of the students have obtained degrees in
physics and chemistry, basic fundamentals such as
those encountered in material and energy balances,
heat transfer, fluid flow, mass transfer and
thermodynamics, must all be covered to bring such
candidates into applied engineering. The differ-
ence between the thought process of the scientist,
and that of an engineer is a basic and a real one.
Review courses are aimed to give the students
basic tools for developing good engineering judge-
ment, and to approach and think of their problems
as good engineers do.

... "


Developing modern cities in the developing countries.
After this review, other basic courses such as
energy conversion and resources, gas piping sys-
tems, natural gas properties, pressure regulation
and measurements, corrosion control of under-
ground piping systems, transmission and distribu-
tion systems, and gas utilization are presented to
give the spectrum needed for formulating this
specialty in gas transmission and distribution.
CONCLUSION
AT BOUMERDES a huge and attractive build-
ing is about to be finished. It is destined to be
the major headquarters for the Algerian Petro-
leum Institute. This large building will house
administrative offices whether for the engineering
or technicians' programs. It will also have class-
rooms and laboratories for the engineers and for
research and development. This future home of
IAP, which will be finished in less than two years,
is in the midst of a scientific and technical complex


which contains various institutes. Among these
are the National Institute of Hydrocarbons
(INH), the National Institute of Light Industries
(INIL), the National Institute of Productivity
and Industrial Development (INPED), along with
the central laboratories for Sonatrach, Sonarem
and the National Society for Materials of Con-
struction.
Fine talents from throughout the world and
Algeria have been chosen to bring about an
Algerian Petroleum Institute which will train the
brain-trusts who will develop the petroleum and
gas industry and bring more progress to their
homeland. The students that IAP recruits are dedi-
cated and hard working. They will be a fine asset
to the future of Algeria. Many of these students
rank among the top ten percent found in American
engineering schools.
In the years to come, IAP should play a great
role in the training of engineers and technicians,
not only for Algeria, but some of the oil producing
countries and the third world as a whole. Its ac-
complishments are impressive and its future is a
bright one indeed. O
ACKNOWLEDGMENTS
The authors kindly acknowledge the help of
M. Baghli, Directeur G6neral of the Algerian
Petroleum Institute; M. Benammar, Directeur
Technique; M. Bouzertini, Directeur d'Engineer-
ing; and M. Souidi, former Chef de Department.

ASEE AWARDS
Continued from page 107.
the Department of Technology and Human Af-
fairs, and director of the Center for Development
Technology at Washington University. The award
is sponsored by the Xerox Corporation.
DR. GEORGE BURNET, Anson Marston Dis-
tinguished Professor and Head of the Department
of Chemical and Nuclear Engineering at Iowa
State, has been elected to Honorary Membership
in ASEE. Nominations are made to the Commit-
tee on Honorary Membership and the Committee
in turn recommends candidates to the Board of
Directors, which elects not more than two Hon-
orary Members each year. They are chosen for
eminent service to mankind in engineering educa-
tion or other engineering fields.
The Western Electric Fund Awards were pre-
sented to the following: ROBERT G. SQUIRES
in the Illinois-Indiana Section and GORDON R.
YOUNGQUIST in the St. Lawrence Section.


SUMMER 1978









nI laboratory


TWO EXPERIMENTS

FOR ESTIMATING FREE CONVECTION

AND RADIATION HEAT TRANSFER COEFFICIENTS


MICHAEL J. ECONOMIDES* AND
J. O. MALONEY
University of Kansas
Lawrence, Kansas 66045

T HIS ARTICLE DESCRIBES two simple
undergraduate heat transfer experiments
which, when properly understood, may reinforce
a student's understanding of free convection and
radiation.
The purposes of the experiments are:
* To demonstrate how the combined individual co-
efficients for free convection and radiation 'nay be ex-
tracted from an experimentally determined overall heat
transfer coefficient by arranging experimental condi-
tions in such a way that the major resistances to heat
transfer are the two of interest and all other resistances
are so small as to be negligible.
* To illustrate a technique for reducing the radiation heat
transfer coefficient to such a small value that a close
estimation of the free convection coefficient is possible.
In designing experiments for our undergradu-
ates, we have attempted to keep them as simple
as possible, and we wish to have the principle or
principles they demonstrate to be so obvious that
they are difficult to overlook. Also, we wish to
have the results agree fairly closely with those
values reported in the standard texts or with those
values which would be calculated from standard
correlations. Finally, we believe that students
should either do or see done experiments which
demonstrate the major phenomena we cover in
our lecture courses. Although both free convection
and radiation are covered in most lecture courses
on heat transfer, few simple laboratory experi-
ments seem to be available. We hope that the two

*Present Address: Petroleum Engineering Dept., Stan-
ford U., Stanford, CA 94305.


experiments about to be described will be of some
interest and use to instructors and students con-
cerned with this subject.

APPARATUS
T HE FUNCTION OF the apparatus is to pro-
vide data from which one may calculate an
overall heat transfer coefficient. It consists, in its
basic form, of a vertical glass tube exposed to the
air, into the bottom of which is passed a stream
of saturated vapor. As the vapor rises up through
the tube and passes out the top of it, a portion









eg I





Michael Economides has attended the University of Kansas where
he obtained both B.S. and M.S. degrees in chemical engineering.
Between degrees he has worked as a process engineer for Celanese
Chem. Co. He is currently pursuing a Ph.D. at the University of
California, Berkeley. His main interests are process design and
economics. (L)
James 0. Maloney is professor of Chemical Engineering at the
University of Kansas. He received his B.S. Degree from the University
of Illinois and his M.S. and Ph.D. Degrees from the Pennsylvania
State University. He has been employed by the Dupont Company and
has held Fulbright posts at Naples, Italy; Cairo, Egypt; and Athens,
Greece. (R)


CHEMICAL ENGINEERING EDUCATION









of the vapor condenses on the walls and runs down
to the bottom of the tube. This condensate is
drawn off and its rate of production measured.
Knowing this, the latent heat of condensation, the
area and the temperature difference, one may cal-
culate the heat loss from the tube and the overall
heat transfer coefficient.
Thus:

(m) (h,) = Q/0 = U(iDoL) (Tv TA)
where


m
hv
Q/0
Do
L

Tv

TA
U


= lb. condensate per hour
= latent heat of condensation, Btu/lb.
= heat loss from the tube, Btu/hr.
= outside diameter of the tube, ft.
= length of the tube on which condensa-
tion occurs, ft.
= temperature of the saturated vapor,
OF.
= temperature of the air, oF.
= overall heat transfer coefficient,
Btu/ (hr. ft2 0F)


When this overall coefficient is determined ex-
perimentally, it is found to range from 2.2 to 3.4.
A consideration of this heat transfer process
shows that there are three resistances in series
to heat transfer: that resulting from the con-
densing vapor, that from the glass tube, and that
of the combined resistance of free convection and
radiation from the outside surface of the tube.
That is:

Rtotal = R(cond. vapor) + Rtube + R(conv. + rad.)


1
(hA)cond. vapor
inside surface


+ tubeL
+ kA tube


(hn.+ hrad.)A outside
c surface
The resistance of the condensing vapor is in
the range of 0.005 to 0.0005 reciprocal Btu/(hr.
ft.2 OF), i.e., coefficients of 200 to 2,000. The re-
sistance of the glass tube is about 0.013 [2.5 mm.
thick, borosilica glass and a k of 0.63 Btu/(hr.
ft. OF)]. Free convection coefficients on the out-
side of the tube are in the range of 1 to 2 Btu/
hr. ft.2 OF), and the radiation coefficients are in
the same range or less. One can thus draw the
preliminary conclusion that the overall coefficient
will be essentially composed of the combination
of a convection and a radiation coefficient from
the outside of the tube.
Glass has an emissivity of about 0.9, but if it
is wrapped tightly with polished aluminum foil,

SUMMER 1978


water


Condensate Return
Line -


:water in


Aluminum foil
used was 2 inches
wide and 0.0015
inches thick.


SColumn
(30.5 mm O.D.
glass tube;
3 lengths
17, 28.5, 49
inches were
used.)

- Reflux counting
trap


-- Still
pot


Drain tap "Tl'
FIGURE 1. Vertical Column for Heat Transfer
Coefficient Measurements

the emissivity of the vertical tube would be
reduced from about 0.9 to about 0.05. Thus by
wrapping the tube with aluminum foil the radia-
tion coefficient can be so markedly reduced that
the overall coefficient essentially equals the free
convection coefficient.
The apparatus actually used in the experiment
is shown in schematic form in Figure 1. The only
unusual feature was the reflux counting trap [1]
which was a vacuum jacketed device that allowed
measurement of a known volume of liquid con-
densate and separated the condensate stream
from the rising vapor stream. Any device which
will accomplish this purpose would be satisfactory.
The excess vapor, which is necessary in order to
be certain that the entire length of the column
is at a constant temperature, does not need to
be recycled provided the still pot contains enough
liquid for several runs. The boil-up rate had no
significant effect on the overall heat transfer co-
efficient as long as excess vapor left the top of the
tube. The liquid in the still pot was vaporized by
an immersion-type heater, but an exterior heater
would, of course, work satisfactorily. A certain
amount of care probably should be used to mini-
mize the effects of any forced convection around
the column. In our experiments, the air condition-

123










TABLE 1. Effect of the Tube Height and Surface
Condition on Overall HeatTransfer Coefficients

Sytemn: -.Buttnol
Tube Columo Surface 0o Condensate
Hsl.ht Condltin Temperaturs. "F. g Q v
In. n o-ol ,,r groms/t., Btu/hr. Btu/(hr.) (sq. ft) (0.)
17 Br Glaa. 242.6 82.4 383.9 215.3 3.02
28.5 B1 Glass_ 242.6 75.2 680.8 381.7 3.05
49 Bare Glaes 242.6 82.4 1149.0 644.2 3.13
17 Alu inm Wrapped 241.7 76.1 227.0 127.5 1.73
28.5 A.lunlo Wlrpped 242.6 75.2 380.7 213. 1.71
49 Alu-inu Wrappod 242.6 82.4 632.0 349.9 1.70
System: uater

28.5 A lumln wrapped 211.1 73.4 76.3 163 1.57


Example : F-irt nu


.81. toL' o.(3i@ 2sO)(s(X .,'0 ...5t0.
7 = (215.3)/((242.6-82.4)(0 .445))
= 3.02 0tu/(hr.)(.q.ft.)(F.)


ing vents were covered, and the windows were
closed. In several runs, the entire assembly was
surrounded with a vertical cardboard shield
about two feet away from the column, but no
significant difference in results was found. The
columns we used were fitted with TS joints for
ease of assembly.


EXPERIMENTAL PROCEDURE

Two main types of runs were done: (1) those
in which the glass tube was left bare, and (2)
those in which the glass tube was covered with
aluminum foil. During either type of run a
reasonably pure liquid was placed in the still pot
where it was boiled. Vapor ascended through the
reflux trap into the tube. A certain amount con-
densed on the sides of the column, and the remain-
ing vapor passed through the opening on the top
of the column and off into the adjoining con-
denser. The condensate from it was then re-
cycled via a condensate return and back into the
still pot.
Whenever a measurement was desired, the

TABLE 2. Effect of Temperature Difference or the
Overall Heat Transfer Coefficient

Diff11erence In Teperatur Condaot.e
Copond etvween Soil8 g Liquid dAr amte 0
OF. S/hr. Bt u/hr. stu/(hr.)(sq.ft.)(OF.
A-cetn 59.9 132.2 63.5 1.12
Methol 66.6 71.1 80.2 1 61
Ben-0 98.5 308.2 115.2 1.57
Water 137.7 73. 163. 1.57
Soluee 155.3 596.7 M7.5 1 .71
n-But5 noi 161.8 390.8 219. 1.82
0n-Oct ol 307.6 1549.7 599.6 2.61


Example: Fint Rm


*. D L= (.) 0x 419 .
= 0. 7 sq. ft.
T A7 = ( = 3 1..4 B .t/(1h.) q.ft.)(OF.)


3.0
2.5



1.
00 15

ii


-s




0 6 -

0.5 T0.25



50 60 70 60 90 100


5.5 2 2 300 I 0 0


FIGURE 2. Measured Overall Heat Transfer Coefficients
Together with a Plot of the Perry Third Edition Formula
for Free Convection Coefficients



In order to have a variety of temperature
driving forces, a number of liquids of various
boiling points were used, including: acetone, ben-
zene, toluene, water, methanol, n-butanol, n-amyl
alcohol, and n-octanol (BP, range 56-195C.).


TYPICAL RESULTS

S OME TYPICAL RESULTS are shown in
Tables 1 and 2. Table 1 shows two things. It
shows that the overall coefficient is essentially
independent of tube heights from 17 to 49 inches
and that wrapping the tube tightly with aluminum
foil results in a marked decrease in the overall co-
efficient from 3.1 to 1.7. Table 2 and Figure 2
show that the overall coefficient generally increases
as the temperature difference between the boiling
points of the compound and the air increases.


CHEMICAL ENGINEERING EDUCATION


three-way valve attached to the reflux trap, was
closed. The time required for the reflux trap to fill
up to a marked level was recorded. Then the con-
densate was allowed to flow back into the still pot.
This measuring procedure was repeated several
times. After the last timing, the condensate in the
reflux trap (up to the marked level) was collected
and weighed.
During the run the temperature of the boiling
liquid was measured by a thermometer immersed
in a well in the still pot. In some later runs a
thermometer was placed in the top of the tube to
measure the vapor temperature there. The still
pot temperature and this temperature were es-
sentially identical. The ambient temperature was
also measured.
A brief study was made of the effect of tube
length on the overall heat transfer coefficients.
Tubes of 17, 28.5 and 49 in. in length were used.


150 200 250 300o 00









DISCUSSION


T IS CUSTOMARY to have students compare
their results calculated from experimental data
with values found in the literature. The procedure
used here is to compare the experimental value
with ones calculated using the methods found in
the five consecutive editions of Perry's Chemical
Engineers' Handbook. The particular comparison
shown here is for the case of water condensing at
735 mm. Hg and 99.50C. inside a 28.5 inch long
vertical tube 1.2 inches in outside diameter. The
tube was carefully wrapped with shiny aluminum
foil. The air temperature was 23C. The measured
overall U was 1.57 Btu/(hr. ft.2 OF.).
The principal reason for selecting the pro-
cedures found in Perry is that it is a reference
more widely available to undergraduates than any
particular text on heat transfer.
While all of the details of calculating the
values by each method will not be gone through,
the values used in the calculation will be shown.


First Edition [2]
hvert. cylinder

hhor. cylinder

film temp.

P2ATm
D
hhor. cylinder
shape factor
hvert. cylinder


Second Edition [


= hhor. cylinder X shape fact
p2AT
= f (film temp., p m
D
(99.5 + 23) 61
S 2 61.3
2

(0.97)2(99.5 -23)
1.2
= 1.2 Btu/ (hr. ft.2 oF.)
= 1.22
= (1.2) (1.22)
= 1.46 Btu/ (hr. ft.2 oF.)
3]:


For long vertical pipes:


or


,. n At, \0.25
hc = 0.4( t-D )0.25

At, = 211.1-73.4 = 137.7
h 0. 137.7 0.25
h = '.4 .2 = 1.31 Btu/ (hr. ft.2 F.)

Third Edition [4]:
For long vertical pipes:

hc = 0.5 Dt 0.25

5 137.7 \ 0.25 f
0.5 1.2 )= 1.64 Btu/ (hr. ft.2 F.)


Fourth Edition [5]:
For vertical surfaces:
hcL m
-h a(x)m
k
forx>109; a = 0.13, m = 1/3

x L gp2gAt c/,t~
X L- '2 k i film temperature
(2.38)3 (0.0636)2 (4.18x108)
(0.001673) (137.7) (0.70)


x =


(0.0465)2


= 1.7x109

h = (0.13) (1.7x109) / 0.0166
\ 2.9- 8
= 1.08 Btu/ (hr. ft.2 0F.)
Fifth Edition [6]:
For vertical surfaces:
NNP = a(NGrNp) m
forx>109; a = 0.13, m = 1/3
This is the same procedure as found in the
fourth edition, so:


he = 1.08 Btu/ (hr. ft.2 OF.)
The results of these calculations are summarized
in Table 3. One sees considerable variation among
oC the results. Two comments may be made about
the five procedures. Nothing is stated about how
well these calculated values agree with experi-
- 60
mental values. Furthermore, as the calculational
procedures change from edition to edition, no
reasons are stated for making the changes. A

TABLE 3
Natural Convection Coefficients for Air
As Calculated from Procedures Found in
Five Consecutive Editions of
Perry's Chemical Engineers' Handbook


Edition
First
Second
Third
Fourth
Fifth


Date
1934
1941
1950
1963
1973


he, Btu/(hr. ft.2 OF.)
1.46
1.31
1.67
1.08
1.08


student looking at the wide range of these values
might be somewhat confused or not know exactly
how to proceed; without access to the actual data
upon which the methods in Perry are based, (s) he
is probably at an impasse.
Table 4 and Figure 2 have been prepared
using experimental results and the correlation


SUMMER 1978








TABLE 4. Comparison of Overall Measured U with
the Calculated Free Convection Coefficients for the
Aluminum Wrapped Tube

Substance U Measured ho Calculated
Btu/(hr.)(sq.ft.)(OF.) Btu/(hr. )(q.ft.)(O .)

Acetone 1.42 1.34
Methanol 1.61 1.37
Benzene 1.57 1.51
Water 1.57 1.67
Toluene 1.74 1.70
n-Butanol 1.82 1.71
n-Octanol 2.61 2.01



equation from the third edition of Perry:
SAt 0 .25
he = 0.5= -)

he = free convection coefficient, Btu/(hr.
ft.2 OF.)
At, = temperature difference between the
hot surface and the ambient air, OF.
Do' = diameter of the tube, in.
One observes that the trend of the values is
similar to that predicted by the equation and that
he is usually lower than the overall heat transfer
coefficient, as would be expected.
Another calculation can be made to take the
radiation heat loss into account. The radiation
heat loss can be estimated from Stefan's Law:


Qr = oeA (T, Ta4)


where


Qr = heat transfer rate, Btu/hr.
a- = 0.1717 x 10-8
e = tube surface emissivity
A = the area of heat transfer, sq. ft.
Ts = surface temperature of the tube, oR.
Ta = air temperature, OR.
Table 5 shows the results of two calculations
in which the amount of heat transferred by radia-
tion is estimated from the 28.5 in. long tube, using
n-butanol as the boiling material. In the first case,


TABLE 5. Estimated Heat Loss by Radiation and the
Radiation Heat Transfer Coefficient

Tube Condition Emissivity, E ttotal tr free convection hr
Btu/hr. Btu/hr. Btu/hr.
Bare Gla0 s 0.9 381.7 185.9 195.8 1.47
Alunma um Covered 0.05 213.5 10.3 205.2 0.08


the tube is bare and the glass emissivity is taken
as 0.9. In the second case, the aluminum emissivity
is taken as 0.05. The two emissivity values are
taken from Kreith [7]. From the heat lost by
radiation, the two radiation heat transfer co-
efficients were calculated. One sees from the calcu-
lation that an aluminum covering should markedly
reduce the coefficient, which is exactly what hap-
pened experimentally.
The two values of hr calculated may be used
together with the measured overall U for the bare
tube to estimate the overall coefficient for the
aluminum foil wrapped tube as follows:

overall U with bare tube 3.05 Btu/ (hr. ft.2 OF.)


reduction by radiation
coefficient of bare tube

net he
add back radiation co-
efficient of Al-foil
surface

estimated overall U,
Al-wrapped tube
measured overall U,
Al-wrapped tube


1.47 Btu/ (hr. ft.2 oF.)

1.58 Btu/ (hr. ft.2 oF.)


0.08 Btu/ (hr. ft.2 oF.)


1.66 Btu/ (hr. ft.2 oF.)

1.71 Btu/ (hr. ft.2 0F.)


One sees that the estimated and measured overall
U for this case are very close.

CONCLUSIONS
* These experiments provide a means for measuring over-
all heat transfer coefficients under conditions where
free convection and radiation are controlling the
transfer.
* The experiments show how the radiation coefficient
may be reduced so much that free convection is con-
trolling the heat transfer.
* Application of procedures found in successive editions
of Perry's Chemical Engineers' Handbook to estimate
free convection coefficients give significantly different
answers.
* A closer inspection of the data on which the cor-
relating procedures found in Perry are based seems
warranted. 5

REFERENCES
1. Scientific Glass and Instruments, Inc., Catalog, Hous-
ton, Texas, Item 9190.
2. Perry, J. H., Chemical Engineers' Handbook, McGraw-
Hill, 1st Ed., 1934, pp. 861-864.
3. Ibid, 2nd Ed., 1941, pp. 985-987.
4. Ibid, 3rd Ed., 1950, pp. 474-476.
5. Ibid., 4th Ed., 1965, pp. 10-10 10-13.
6. Ibid, 5th Ed., 1973, pp. 10-10 10-12.
7. Kreith, Frank, Principles of Heat Transfer, 3rd
Edition, Intext Press, Inc., 1973, pp. 236-237.


CHEMICAL ENGINEERING EDUCATION








REID: Award Lecture
Continued from page 111.
an explosion; is this the time to superheat water
or does it represent an interval of time to place
water below the smelt surface so that the later
injection force can collapse the vapor film? Higher
injection velocities enhanced explosion probabil-
ities-for the same reason? Hot water explodes
with difficulty: is the steam vapor film now too
thick to be collapsed? Why should "green liquor"
lead to more violent explosions?
Studies are critically needed to determine if
there is a minimum force or shock necessary to
establish initial liquid-liquid contact-and, if so,
what is the effect of the independent system varia-
bles on this force.

CRYOGEN-WATER EXPLOSIONS
IN ALL CASES DESCRIBED earlier, water was
contacted with a hot liquid. But vapor explo-
sions can also occur when cryogenic liquids con-
tact water. The system R-12 or R-22/water has
been studied in several laboratories (Holt and
Muenker, 1972; Rausch and Levine, 1973; Henry
et al., 1974; Anderson and Armstrong, 1977).
We have been interested in vapor explosions
involving light hydrocarbons. The impetus for
this study began in 1970 when the U. S. Bureau
of Mines reported that, in two instances, vapor
explosions resulted when liquefied natural gas
(LNG) spilled upon a water surface (Burgess
et al., 1970). The explosions did not lead to igni-
tion, but they were sufficiently severe to cause
concern to the burgeoning LNG industry.
Extensive research programs were initiated
by the Shell Pipe Line Corp. (Enger and Hart-


.... a small leak in the roof must have allowed
water from a tropical downpour to fall unobserved
into a ladle. The resulting explosion ejected matte
40 feet into the air, killing the craneman in his cab.


man, 1972) and in our own laboratories
(Nakanishi and Reid, 1971; Porteous and Reid,
1976). (See also, Katz and Sliepcevich, 1971;
Katz, 1972; Burgess et al., 1972.)
Light hydrocarbon-water vapor explosions al-
most certainly result when a portion of the liquid
hydrocarbon is heated to a temperature where it
may undergo homogeneous nucleation. Usually, in
simple spills, only a thin film is involved and the


-- Th 5C
-- Th 21 C
-- Th= 33 C


0 1 I I I I I I
0 4 8 12 16 20 24
Impact Velocity (m/s)

FIGURE 16 EFFECT OF IMPACT VELOCITY AND WATER
TEMPERATURE ON PEAK PRESSURE,
ETHANE AND WATER
resulting explosion, while impressive, is not par-
ticularly energetic nor damaging.
Based on the proposed theory, there then exists
a clear definition of interactions which cannot
produce vapor explosions. If Tw is the bulk water
temperature and TSL the homogeneous nucleation
temperature of the light hydrocarbon (pure or
mixture), then, for a true vapor explosion, Tw >
TSL. In literally hundreds of different experiments
with various water temperatures and cryogens,
this criterion is rarely violated.* There now is
general agreement that one can predict if a vapor
explosion is possible knowing only the initial
water temperature and the value of TSL for the
hydrocarbon. (It is important to note that if TSL
> Tw, and the two liquids are rapidly mixed,
rather violent boiling may still ensue, but no shock
waves characteristic of an explosion are noted.)
For simple spills of hydrocarbons into water
(or vice versa), the probability of an explosion is
the highest when Tw only slightly exceeds TSL.
That is,
Tw/TsL > 1 criterion for a vapor explosion
Tw/TSL = 1.04 1.06 criterion for maximum
probability for a vapor explosion in simple
spills of light hydrocarbons on water.

*Porteous and Reid (1976) show data which indicate a
vapor explosion resulted in the propene-water system when
Tw/TsL 0.97 to 1.06 and for n-butane-water at Tw/T,, =
0.98. In all other cases TW/TsL s 1.


SUMMER 1978








These criteria are in excellent agreement with
experimental data; the first is general and inde-
pendent of the fluids, the second must be modified
if the hot liquid has thermal properties different
from water. For example, if methanol is used, the
Tw/TsL range for maximum probability increases
to about 1.14 1.20.
Such a variation of the limiting Thot/TSL cri-
teria follows the hypothesis of Henry et al. (1974)
that one should employ the interface temperature
rather than the bulk hot liquid temperature to
develop a criterion for vapor explosions. That is,
the interface temperature upon contact of the two
liquids must be greater than the homogeneous
nucleation temperature of the volatile one before a
large-scale vapor explosion can occur. To estimate
this interface temperature, a simple one-dimen-
sional heat transfer model is proposed wherein
the two liquids are contacted at time zero. Assum-
ing constant thermal properties and no phase
changes, the interfacial temperature, Ti, is in-
variant with time and depends only on the original
temperatures of the hot liquid (Th) and cold
liquid (T,) and their thermal properties, i.e.,


T,-T khphCh 1/2
Th Ti (kepC


The symbols k, p, and C refer to the thermal con-
ductivity, the density, and the heat capacity with
subscripts h and c denoting the hot and cold
liquids.
Of considerable current interest is the develop-
ment of an explosion criteria for large values of
Tw/TsL. For example, pure liquefied methane on
300 K water has a ratio of Tw/TSL 1.77. To date
no one has been able to obtain a vapor explosion by
contacting liquid methane (Tb = 111.7 K) and
Explosion
o No Explosion
Propane
Tw / TsL1 A


e n- Butane
Explosive Region


Ethane


EXPLOSIVE CORNER ENLARGED


Explosive Envelope for Ethne -Propane -Butone Mixtures
with 298 K Water. Impact Velocity = 21.5 m/s
FIGURE 17


water at any temperature. The argument usually
presented is not dissimilar to those invoked earlier
for water-molten metal, water-smelt, etc., i.e., for
large temperature differences, stable film boiling
occurs and liquid-liquid contact is not possible. Yet
as we have seen several times, explosions may be-
come possible if there is some sufficiently severe
impact event to drive the liquids into contact.
We have been investigating this possibility in
our laboratory in the past year, and initial results
Propone


Ethane


20 40 60 80


Methane


Explosive Envelope for Simple Spills of Methane-
Ethane-Propane on 298 K Water
FIGURE 18
strongly confirm this hypothesis. As an illustra-
tion, pure ethane has always been somewhat of an
enigma. The homogeneous nucleation temperature,
TsL, is 269 K yet we have never obtained a vapor
explosion by spilling ethane on water at any tem-
perature. Rapid boiling does occur with concomit-
ant ice formation-but nothing more. Recent ex-
periments by Jazayeri (1977) have nevertheless
been quite successful in obtaining ethane-water
explosions by impacting the two liquids. The ex-
perimental equipment is shown in Figure 15 and
the ethane-water data in Figure 16. A high fre-
quency quartz transducer mounted about 10 cm
above the surface of the polyethylene cryogen
vessel was used to measure the combined interac-
tion pressure and the impaction pressure of the
ejected mass of liquid. Usually, 350 cm3 of water
was impacted on about 200 cm3 of liquid ethane.
High speed motion pictures were also taken.
Rather large peak pressures were measured
but the rise time was below 1 ms and it decayed
very rapidly. The force was, however, usually suf-
ficient to fragment the polyethylene vessel holding
the ethane. (In one recent test, the explosion was
sufficiently violent to break a Lexan shield and
shatter the protective glass in a safety hood,!)


CHEMICAL ENGINEERING EDUCATION


(11)










Clearly, higher water temperatures seem to lead to
a more forceful explosion, and we plan to study
this effect in more detail. Finally, extrapolation of
the line for a water temperature of 21 C to a peak
pressure of zero guage pressure indicates that a
minimum velocity of about 5 m/s is required to be
successful in attaining vapor explosions. Higher
inception velocities would be expected as the water
temperature increases. These values are, however,
not general and are certainly related to the specific
geometry and impacting technique employed.
Our "map" showing explosive regions (includ-
ing impact experiments) for the ethane-propane-
n-butane ternary is shown in Figure 17 for 298 K
water. A similar plot, showing the theoretical
limits for the methane-ethane-propane system is
shown in Figure 18.
In Part 3, we discuss other types of vapor ex-
plosions and summarize theories (other than
superheated liquids) that have been proposed to
explain their occurrence. El



REFERENCES

Anderson, R. P. and D. R. Armstrong, "R-22 Vapor Explo-
sions", Paper presented at the Winter Annual ASME
Meeting, 1977.
Beall, R. A. (and others), "Cold-Mold Arc Melting and
Casting", U. S. Dept. of the Interior, Bureau of Mines
Bulletin, 646, 1968.
Board, S. J. and L. Caldarola, "Fuel-Coolant Interactions in
Fast Reactors". Paper presented at the Annual ASME
Meeting, New York, Nov., 1977.
Burgess, D. S., J. Biordi, and J. Murphy, "Hazards of
Spillage of LNG into Water", U. S. Bureau of Mines,
PMSRC Report No. 4177, 1972.
Burgess, D. S., J. N. Murphy, and M. G. Zabetakis, "Haz-
ards Associated with the Spillage of Liquefied Natural
Gas on Water", U. S. Bureau of Mines RI 7448, 1970.
Enger, T. and D. E. Hartman, "Mechanics of the LNG-
Water Interaction". Paper presented at the Am. Gas
Assn. Distribution Conference, Atlanta, GA, May, 1972.
Henry, R. E., J. D. Gabor, I. O. Winsch, E. A. Spleha, D. J.
Quinn, E. G. Erickson, J. J. Heiberger, and G. T. Gold-
fuss, "Large Scale Vapor Explosions", Proc. Fast Re-
actor Safety Meeting, Beverly Hills, CA, Conf. 740401-
P2.922, April 2, 1974.
Hess, P. D. and K. J. Brondyke, "Causes of Molten Alum-
inum-Water Explosions", Metal Prog. 95, 93 (April),
1969.
Holt, R. J. and A. H. Muenker, "Flameless Vapor Explo-
sions in LNG/Hydrocarbon Spills", Report No. GRU.2
GPR.72, Exxon Research and Eng. Co., Linden, NJ,
1972.
Jazayeri, Behzad, "Impact Cryogenic Vapor Explosions",
S. M. Thesis, Department of Chemical Eng., M.I.T.,
Cambridge, MA, 1977.


Katz, D. L. and C. M. Sliepcevich, "LGN/Water Explosions:
Cause and Effect", Hydro. Proc. 50 (11), 240 (1971).
Katz, D. L., "Superheat-limit Explosions," Chewm. Eng.
Prog. 68 (5), 68 (1972).
Krause, H. H., R. Simon and A. Levy, "Smelt-Water Ex-
plosions", Battelle Columbus Laboratories, Columbus,
OH, 1973.
Long, G., "Explosions of Molten Aluminum in Water-Cause
and Prevention", Metal Prog. 71, 107 (May), 1957.
Nakanishi, E. and R. C. Reid, "Liquid Natural Gas Water
Reactions", Chem. Eng. Prog. 67, (12), 36 (1971).
Nelson, W., "A New Theory to Explain Physical Explo-
sions". Paper presented at the Black Liquor Recovery
Boiler Advisory Committee Meeting, Atlanta, GA, Oct.,
1972.
Nelson, W. and E. H. Kennedy, "What Causes Kraft Dis-
solving Tank Explosions", Paper Trade J., July 16, 1951,
p. 50; July 23, 1956, p. 30.
Porteous, W. M. and R. C. Reid, "Light Hydrocarbon Vapor
Explosions", Chem. Eng. Prog. 12 (5), 83 (1976).
Rausch, A. H. and A. D. Levine, "Rapid Phase Transition
Caused by Thermodynamic Instability in Cryogens",
Cryogenics 13 (4), 224 (1973).
Sallack, J. A., "An Investigation of Explosions in the Soda
Smelt Dissolving Operation," Pulp and Paper Mag. of
Canada, Sept. 1955, p. 114.
Wright, R. W. and G. H. Humberstone, "Dispersal and
Pressure Generation by Water Impact Upon Molten
Aluminum", Trans. Am. Nucl. Soc. 9, 305, (1966).



[ 6 E letters


BOOK AUTHOR RESPONDS TO
REVIEWER'S CRITICISMS
Sir:
I very much appreciated the detailed review of my
book "Biomedical Engineering Principles" by Professor
E. F. Leonard in the Spring 1978 issue. I would like to
point out, however, that I was every bit as disturbed as
Professor Leonard that the reproduction was by photo-
offset means and that the list price was set so high
($36.50). About the style of reproduction there was really
no choice-it was a simple matter of being published in
that form or not being published at all. Regarding the
price, I am happy to report that my own displeasure en-
couraged the publisher to reduce the "classroom adoption
price" (5 or more copies) to $19.75.
Finally, I agree with Professor Leonard that the bio-
medical engineering field seems to lack a clear direction
and sense of purpose. It is thus not surprising that the
book reflects this to some degree. I struggled internally
while writing the book to define a clear direction, and still
continue to do so as I teach in the biomedical area. Un-
fortunately, in the continued absence of any significant job
market in biomedical engineering, I (and I would guess
most everyone else) remain at least a little unsure as to
what the proper pedagogical approach should be.
David O. Cooney
Clarkson School of Tech.


SUMMER 1978









"P laboratory





ON THE APPLICATION OF SIMPLE EXPERIMENTS

TO THE TEACHING

OF ChE THERMODYNAMICS


KENNETH M. McNEIL
Drexel University
Philadelphia, Pennsylvania 19104

HISTORICALLY, THERMODYNAMICS has
been considered one of the most elegant but
abstract branches of physico-chemical science. Its
fundamental importance in engineering requires
that it be taught both at the undergraduate and
graduate levels. For that reason, however, it is one
of the most difficult subjects to teach effectively.
At Drexel University, the undergraduate chemical
engineering student is initially exposed to thermo-
dynamics in the common basic thermodynamics
course taken by all engineering sophomores, which
provides an introduction to the first and second
laws, heat engine cycles, and ideal gas relation-
ships. Concurrently, an elementary treatment of
thermochemistry, energy balances, and thermo-
dynamic properties is given in the material bal-
ances course. Instruction continues in the ChE
Thermodynamics course, taken in the second
quarter of the sophomore year. Finally, some
aspects of statistical thermodynamics are covered
in physical chemistry, taken in the second quarter
of the pre-junior year. (At Drexel, the B.S. degree
requires five years due to the cooperative education
program; of the twelve quarters required, three
each are attended in the freshman and senior


The addition of a
series of simple experiments
to an established lecture course is a
concept novel to ChE curriculum
at Drexel University.


Present address: 4000 Gypsy Lane, Philadelphia, Pa 19144


years, two each in the sophomore, pre-junior, and
junior years. The student also works in a suitable
technical position in industry for six months in
each of the three middle years.)
The ChE Thermodynamics course consists of
4 credit hours devoted to such traditional class-
room activities as lectures and problem-solving,
and a 1-credit hour (2 contact hours) laboratory
which was initiated in 1971. The main objective of
the overall course is to equip the student with a
basic working knowledge of the concepts and
practical applications of ChE thermodynamics,
thereby also providing an adequate foundation for
subsequent undergraduate courses in kinetics and
reactor design, transport phenomena, unit opera-
tions, and process design, and for graduate courses
TABLE 1. Lecture Topics
First and Second Laws of Thermodynamics (review)
Thermodynamic analysis of processes
Pressure-volume-temperature relationships for real
fluids
Thermodynamic properties of real fluids
Thermodynamics of incompressible and compressible
fluid flow
Phase equilibria in pure and multicomponent systems
Chemical-reaction equilibria (homogeneous systems)
in thermodynamics and kinetics. The principal
purpose of the laboratory is to enhance the stu-
dents' understanding of an other wise abstract
subject; instructional objectives are discussed
more fully in the next section.
The topics covered in the lectures are stated in
Table 1. The textbook currently used is by Smith
and Van Ness [1].

INSTRUCTIONAL OBJECTIVES OF LABORATORY
THE PRIMARY OBJECTIVE of augmenting
the lectures with a series of short laboratory


CHEMICAL ENGINEERING EDUCATION
























Kenneth M. McNeil, a consulting chemical engineer, was Assistant
Professor of ChE at Drexel University from 1970 to 1976. He is pres-
ently Coordinator of the ChE Review course for the P.E. examination.
After receiving a B.Sc. from the University of Edinburgh (1962), he
studied under Prof. P. V. Danckwerts at the University of Cambridge
(Ph.D., 1965). Between 1965 and 1970, he was on the staff of the
R. & D. Department of Amoco Chemicals Corp. He is a registered
Professional Engineer (Pa.), and is a member of AIChE, ACS, I. Chem.
E., and Sigma Xi.

experiments was to improve the pedagogical effec-
tiveness of the course. Thermodynamics is one of
the more difficult courses conceptually, but is rela-
tively straightforward (at this level) both mathe-
matically and computationally. Whereas numerous
worked examples and homework problems con-
tribute significantly to the learning process, they
are of little help in conveying a sense of reality to
the student. The experiments fill this void, at the
same time exciting curiosity and interest.
The laboratory has several further instruc-
tional objectives. It provides an introduction to
simple measurements, in particular thermocouple
thermometry and differential-pressure flow meas-
urement. This serves as a valuable preparation for
subsequent laboratory courses, which include
transport phenomena, unit operations, and process
control.
In this course, the students receive their first
experience in the planning of experiments, the
analysis of data, and report writing, albeit at an
elementary level. This, too, is helpful preparation
for subsequent laboratory courses, in which con-
siderably more detail is required.
The class is divided into several groups which
retain their identity throughout the course. Each
group consists preferably of three students, one
of whom is appointed group leader for a particular
experiment; each student acts as group leader for
at least two experiments. The course thus exposes
the students to the interpersonal relationships in-


volved in group work, from the viewpoint of both
the group leader and the team member.

EXPERIMENT DESCRIPTIONS

THERE IS ONE experiment corresponding to
each major lecture topic, as listed in Table 2.
There follow brief descriptions of the experiments,
with comments on typical results that have been
obtained.

TABLE 2. List of Experiments
(with Corresponding Lecture Topics)

EXPERIMENT LECTURE TOPIC
Flow Calorimeter First Law
Hilsch Vortex Tube First and Second Laws
Refrigeration Cycle* Thermodynamic analysis
P-V-T Behavior of CO2 P-V-T relationships
Throttling Calorimeter Thermodynamic properties
Maximum Flow in Nozzle Thermodynamics of fluid flow
Triple Point of Nitrogen Phase equilibria
Ethanol-Acetic Acid-Ethyl Chemical equilibria
Equilibrium

*Planned

Flow Calorimeter. The equipment consists of a
simple calorimeter incorporating an electrical re-
sistance which enables electrical energy to be con-
verted to heat and dissipated in the liquid stream.
The liquid (water) is fed to the calorimeter at a
constant rate from a header tank, in which the
level is maintained manually. The flowrate is de-
termined by measuring the volume of effluent in a
given time interval, and the inlet and outlet tem-
peratures are measured with mercury-in-glass
thermometers (Fig. 1). By comparing the input


FIGURE I
FLOW CALORIMETER


SUMMER 1978








of electrical energy to the increase in enthalpy of
the water, the electrical equivalent of heat can be
calculated. Reasonably accurate results for this
relatively crude device have been obtained by the
more careful students (within 107% of the correct
value).
Hilsch Vortex Tube. In this apparatus, high-
pressure air is led tangentially into a tube (con-
structed of Plexiglas) where it expands, giving
rise to a high-speed circumferential motion. As a
result of this expansion, the air as a whole gains
kinetic energy at the expense of its internal en-
ergy, and the temperature therefore falls. The air
near the axis is withdrawn in an axial direction.
It has relatively low kinetic energy (the angular
velocity does not vary greatly with radial position,
and the tangential velocity near the axis is there-
fore low), and thus remains cooler than the inlet
air. The air near to the tube wall, on the other
hand, has a high tangential velocity and hence
kinetic energy. This air is withdrawn in the op-
posite axial direction. As it passes down the tube,
most of the kinetic energy is dissipated by turbu-
lent mixing and the internal energy consequently
increases. The temperature of this stream becomes
higher than the inlet air, as nearly all the internal
energy initially converted to kinetic energy re-
appears as internal energy in only this part of the
original stream.
The apparatus, which is illustrated in Fig. 2,
is provided with means of measuring the tempera-
tures and pressures of all three air streams, and
the flow-rates of the hot and cold effluent streams.
From these data, entropy and enthalpy balances


FIGURE 2
HILSCH VORTEX TUBE

can be carried out over the vortex tube. The ex-
periment has been successful in demonstrating the
applicability of the entropy function to considera-
tions of irreversibility, as well as giving practical
experience in the construction of entropy and


enthalpy balances. Furthermore, it provides an
introduction to important measuring techniques:
thermocouple thermometry, pressure measure-
ment by bourdon gauge and manometer, and flow
measurement by orifice meter and rotameter.
Typical experimental results are presented in
Table 3.

TABLE 3. Hilsch Vortex Tube:
Typical Operating Conditions and Results


Inlet air, temperature
pressure
Hot stream, temperature
pressure
Cold stream, temperature
pressure
Flow ratio, hot stream:
cold stream
Entropy generated
Error in enthalpy balance
(adiabatic conditions
assumed)


820F
45-90 psia
90-970F
20-30 psia
76-710F
- 0.5 psig
-1:2

2.0-3.0 Btu lb mole-1oR-1
-1.5 to 4.0 Btu lb mole-1


Refrigeration Cycle (Planned). A standard
vapor-compression refrigeration cycle, with tem-
perature and pressure sensors before and after
each major component (compressor, condenser,
throttling valve, evaporator), will be used to il-
lustrate the thermodynamic analysis of a cycle
using a pressure-enthalpy diagram. A secondary
objective is to determine the overall and volu-
metric efficiencies of the compressor.
P-V-T Behavior of Carbon Dioxide. The ob-
jectives of this experiment are to measure the
P-V-T behavior of CO2 over a wide range of pres-
sure (50-900 psia) at room temperature, to deter-
mine how accurately the data can be fitted by a
simple equation of state such as the van der Waals,
and to compare the results with values predicted
from a generalized compressibility-factor chart
and also with published data. A lecture bottle of
known volume is evacuated and weighed, and then
charged with CO, at various pressures; the corre-
sponding masses of CO, are measured by differ-
ence.
The results that have been obtained by the
more meticulous experimenters agree well with
published Idata, and also serve to exemplify the
validity of the predictive methods under the range
of conditions investigated. The non-ideal behavior
of a real gas at elevated pressures is convincingly
demonstrated.
Throttling Calorimeter. This simple device
causes wet, high-pressure steam to be throttled


CHEMICAL ENGINEERING EDUCATION








isenthalpically to atmospheric pressure. Provided
that the high-pressure steam is not too wet, the
expanded steam will be superheated. The quality
of the high-pressure steam can then be determined
from a Mollier diagram (or steam tables) if the
line pressure and expanded steam temperature are
known.
The experiment has proved valuable in il-
lustrating the use of thermodynamic diagrams for
a pure substance, and in clarifying the nature of
the isenthalpic flow process.
Maximum Flow in Nozzle. In this experiment,
the occurrence of a maximum mass flowrate of a
gas through a converging-diverging nozzle is ver-
ified. In addition, the observed flowrate and crit-
ical throat pressure are compared with values
predicted from theoretical isentropic flow equa-
tions. The equipment used is a Scott-Armfield
Compressible Flow Bench, Model A.E.C.1. The
pressure upstream of the nozzle is atmospheric,
and a variable subatmospheric pressure on the
downstream side is generated by a compressor
controlled by a throttle on its discharge.
The concept of a maximum flowrate, which
remains constant as the downstream pressure con-
tinues to be reduced below a certain value, is very
difficult to present convincingly in a lecture. After
having performed this experiment, students can
hardly deny the evidence, even if they remain
skeptical.
Triple Point of Nitrogen. The apparatus, il-
lustrated in Fig. 3, consists of an unsilvered
Dewar flask, which permits observation of the con-
tents connected to a mercury manometer and
vacuum pump. Temperature inside the flask is
measured by a copper-constantan thermocouple,
the reference junction being liquid nitrogen boil-
ing at atmospheric pressure in a second, silvered
Dewar flask.
Vapor is withdrawn continuously by the
vacuum pump from the unsilvered Dewar flask,
which contains boiling nitrogen. As the nitrogen
is thermally insulated, vaporization causes its
temperature to fall. Provided that the rate of
vaporization is not too high, the vapor and liquid
are approximately in equilibrium. Thus, simul-


UNSILVERED ; DEWAR
DEWAR FLASK
FLASK
VACUUM
PUMP LIQUID
I NITROGEN
O ( MILLIVOLT
POTENTIOMETER


FIGURE 3
APPARATUS FOR TRIPLE POINT DETERMINATION

taneous readings of pressure and temperature can
be plotted to yield a saturated vapor pressure
curve. When the pressure and temperature have
been lowered sufficiently, the triple point is at-
tained, as signified by the sudden appearance of a
solid phase.
Results have been surprisingly good in view of
the lack of experimental sophistication; values of
temperature within 10%, and of pressure within
15% of their accepted values (63.2K, 0.124 atm
[2]) having been obtained by most students. Care-
ful experimentation by the author yielded a tem-
perature within 2% of the accepted value, and a
pressure within 3%. The experiment serves both
to demonstrate phase behavior of a pure substance
and to provide practice in thermocouple thermo-
metry.
Ethanol-Acetic Acid-Ethyl Acetate Equilib-
rium. The equilibrium
CH5OH + CHsCOOH t CH3COOC2H, + HO
is approached very slowly at room temperature,
but can be achieved in a reasonable time in the
presence of a strong acid catalyst such as hydro-
chloric acid. The equilibrium constant (defined in
terms of mole fractions) can then be calculated
from the weights of the reactants, and the total
acid in the equilibrium mixture as determined by
acid-base titration. The mixtures, which are stored
at room temperature in small stoppered weighing


The main objective of the overall course is to equip the student with
a basic working knowledge of the concepts and practical applications of
ChE thermodynamics, thereby also.providing an adequate foundation for subsequent
undergraduate courses in kinetics and reactor design, transport phenomena, unit operations
process design, and for graduate courses in thermodynamics and kinetics.


SUMMER 1978 133










Despite these shortcomings, however, the concept
of reinforcing the classroom experiences with short
experiments has proved successful, and should
be extended to other suitable courses in
the curriculum such as transport
phenomena, and chemical
kinetics and reactor design.


bottles, are assumed to be equilibrated after one
week.
The principal point that this experiment is in-
tended to demonstrate is that the value of the
equilibrium constant is independent of the initial
and final compositions. Three different initial com-
positions are employed, two being ethanol and
acetic acid in different proportions, the third being
ester and water.
As the apparent value of the equilibrium con-
stant is very sensitive to analytical inaccuracies
[3], results of the less meticulous students have
been considerably scattered. More careful experi-
menters have achieved remarkably consistent re-
sults. However; in the best set of results, the
values ranged from 3.7 to 4.1. These results are in
accord with published data, which themselves ex-
hibit substantial scatter [3]. Disadvantages of the
experiment are its relatively tedious nature (two
class periods are required, cf. one period for the
other experiments), and the necessity for a rela-
tively skillful experimental technique if consistent
results are to be obtained.

INSTRUCTIONAL PROCEDURES

T HE LABORATORY PART of the course is
introduced by means of several lectures. The
first lecture consists of a general orientation, in
which the course objectives, physical facilities,
safety procedures, and required reports are de-
scribed. ,This information is also supplied in a
course manual, which includes general information
and instructions, experimental instructions in-
cluding basic references, and a detailed list of
lecture topics to which the experiments corre-
spond. In three subsequent lectures, techniques of
temperature, pressure, and flow measurement are
described. The students are required to augment
this information with assigned readings from a
reference [4].
As indicated previously, the students work in
groups of three, one student being appointed
group leader for the duration of the experiment,


which is one class period in most cases. Assign-
ment of group leaders is on a rotating basis within
the group. Several days before the experiment is
to be performed, all members of the group attend
a preliminary conference with the instructor, at
which the group leader presents the experimental
plans, which he is responsible for developing. The
preliminary conference fulfills several functions:
it motivates the group leader to prepare ade-
quately, it serves as a forum to clarify miscon-
ceptions (which are not infrequent at this early
stage in the curriculum), and it enlightens the
other group members. Due to the inexperience of
the students, fairly close supervision is given dur-
ing the actual laboratory period.
All students are required to submit a short
written report of each experiment. The required
format is described by the following excerpt from
the instructions.

Introduction-State purpose of investigation, and briefly
describe the appropriate theory including the principal
equations and the procedure for calculating the final
results from the experimentally-measured quantities.
Experimental-Describe the equipment verbally, and by
means of a sketch (which should be on a separate sheet
of paper). State the variables that were measured, and
the instruments used. Indicate what ranges of inde-
pendent variables were studied, and the basis whereby
these ranges were chosen.
Results and Discussion-Present all final results (not
raw data) in tables, graphs, or verbally depending on
which method affords the greatest clarity. Include a
sample calculation. All tables and figures should have a
number and title. Discuss the meaning, significance and
validity of the results. State possible sources of error.
Conclusions-State concisely all significant information
obtained from the experiment. Present each conclusion
in a separate, numbered paragraph.

The reports are graded; the cumulative marks
count pro rata to the overall course grade.

CONCLUSIONS

T HE ADDITION OF A series of simple experi-
ments to an established lecture course is a con-
cept novel to the ChE curriculum at Drexel Uni-
versity. In quantitative terms, there has been a


From a quantitative
standpoint, there has been a
most definite improvement in the students'
motivation and interest.
-


CHEMICAL ENGINEERING EDUCATION








significant upward trend in grade point average,
which has recently been in the region of 2.8/4.0
compared with about 2.0/4.0 before the inception
of the laboratory. This is not of course a true A-B
comparison, but it is generally felt that the av-
erage ability of our students has not changed no-
ticeably in recent years. Moreover, ten out of
fourteen classes were taught by the author over a
period of seven years, which included the transi-
tion from a lecture course to the combined lecture-
laboratory course. Consistency in standards and
grading were thus maintained.
From a qualitative standpoint, there has been
a most definite improvement in the students' mo-
tivation and interest. The only complaint of sub-
stance concerns the lack of multiple set-ups, which
results in students performing some of the experi-
ments before the corresponding topics have been
covered in the lectures. This situation is dictated
by lack of facilities rather than pedagogical philos-
ophy. Whereas students are obliged to study un-
familiar material by themselves, which is salutary
to some extent, it would be more effective from the
point of view of reinforcement, if multiple set-ups
were available to permit parallel operation of the
lectures and experiments.
Despite these shortcomings, however, the con-
cept of reinforcing the classroom experience with
short experiments has proved successful, and
should be extended to other suitable courses in the
curriculum, such as transport phenomena, and
chemical kinetics and reactor design. OE

ACKNOWLEDGMENTS
The author is grateful to many of his col-
leagues for helpful discussions and suggestions,
and in particular to Professor Bernard D. Wood
of Syracuse University, who designed the Vortex
Tube and Triple Point experiments, and Professor
C. William Savery of Drexel University, who de-
signed the P-V-T experiment.

REFERENCES
1. J. M. Smith and H. C. Van Ness, Introduction to Chem-
ical Engineering Thermodynamics, 3rd edition (Mc-
Graw-Hill, New York, 1975).
2. B. R. Brown in Mellor's Comprehensive Treatise on
Inorganic and Theoretical Chemistry, Vol. VIII, Sup-
plement I, p. 37 (Wiley, New York, 1964).
3. S. Glasstone, Textbook of Physical Chemistry, 2nd edi-
tion, pp. 842-3 (Macmillan, London, 1956).
4. R. P. Benedict, Fundamentals of Temperature, Pres-
sure and Flow Measurerments (Wiley, New York,
1969).


CARNEGIE-MELLON
Continued from page 106.
well as with people in computer science, applied
mathematics and operations research. Art is the
Director of the DRC which currently has 17 mem-
bers. As one cooperative project, they are develop-
ing the nonnumeric processing capability of com-
puters to do design.
Prof. Powers is actively studying the use of
fault trees, a technology growing out of the aero-
space industry, to evaluate process safety and re-
liability. He is developing methods to synthesize
and then analyze fault trees, given the process
components and their interconnection. He and
Prof. Westerberg are also developing process syn-
thesis techniques. They work on such problems as
total process flowsheet synthesis, reaction path
synthesis (getting the computer to do chemistry),
separation system synthesis, energy recovery net-
work synthesis, and control system synthesis-in
each case the idea is to get the computer into the
act of suggesting alternative flowsheets. Prof.
Westerberg is also working on advanced ap-
proaches for performing computer-aided process
analysis coupled with optimization.

OVERALL IMPRESSIONS
W WHILE CARNEGIE-MELLON University
may not be all things to all people, the pro-
grams in the areas of Industrial Administration,
Drama, Computer Science and Engineering are
strong with an unusual emphasis on professional-
ism. The urban surroundings of Oakland-an area
filled with parks, a wide selection of ethnic res-
taurants, the Carnegie Library and Museum, and
Scaife Art Gallery-provide a pleasant setting in
which to live and work. Within the Department of
Chemical Engineering, the research interests of
faculty are diverse, from the abstract to the prac-
tical. Although our size is expanding, personal con-
tacts among faculty members, and between the
faculty and students, are frequent and continuous.
From those first impressions of 1974, as well as
from my experience of living here for three years,
I conclude that Carnegie-Mellon University, as
well as Pittsburgh, is "someplace special." O

INN news
Dr. Billy L. Crynes, professor of ChE at Oklahoma
State University, has been approved to head OSU's School
of Chemical Engineering. Crynes received his B.S. from
Rose-Hulman Institute. His M.S. and his Ph.D. are from
Purdue University.


SUMMER 1978













CHEMICAL ENGINEERING AND MODULAR

INSTRUCTION: A STATUS REPORT




KAREN C. COHEN,1 JOSE ALONSO,2
AND ERNEST J. HENLEY3


T HE CHEMI PROJECT, supported by the Na-
tional Science Foundation and the Cache
Corporation, is attempting to produce over 350
single-topic, stand-alone modules spanning the
entire undergraduate chemical engineering cur-
riculum. The project is now about two years old;
one-third of its modules are completed to at least
first-draft stage. This was chosen as an appropri-
ate time, having demonstrated the feasibility of
developing such an ambitious set, to gather imple-
mentation and dissemination data from the pro-
fessors of ChE who are the potential "brokers"
of these modules.
The ASEE (American Society for Engineering
Education) sponsors, with industrial support, a
summer college of its Chemical Education (ChEd)
Division once every five years. This past summer
such a one-week college was run; two members
of every department of ChE in the country were
invited. Approximately 200 persons chose to
attend. This group was representative of ChE
education in attitude and geographic distribution.
It was decided to use this opportunity to:
* acquaint or reacquaint these engineering educators with
the CHEMI Project, and
* obtain attitudinal and potential implementation feed-
back for the project. As each attendee registered on the
first day, he was handed a letter and brief question-
naire, a list of the full anticipated modular set, and a
sample module. Instructions were to go through all the
material and return the questionnaire within a day.
On the whole, the results were extremely en-
couraging. 115 questionnaires were handed out;
61 persons returned completed questionnaires or
approximately 52% of those who had received

1M.I.T. Cambridge, Mass. 02139.
2Swinebourne Institute of Technology, Australia.
3University of Texas at Houston, Texas.
Copyright 1977, Karen C. Cohen.


them. The results of the survey were tabulated and
then presented briefly at a session the following
day, serving as a basis for further discussion and
refinement of the findings. Thus, this survey, al-
though based on a small sample (N = 61), yielded
findings that are broadly representative and are
fairly encouraging regarding the use of CHEMI-
type modules in undergraduate instruction. The
opportunity to discuss the findings during the
meeting itself was well received and resulted in
added insight into, or clarification of, some re-
sponses.

FINDINGS

THE INVESTIGATORS were particularly in-
terested in the relationship between previous
exposure to modular materials (as a student or as
an instructor) and perceived implementation ad-
vantages and disadvantages in their use. There
were a few interesting differences:
Previous Exposure to Modular Material
34 Yes 26 No 1 Blank
(52%) (46%) (2%)
The respondents were fairly evenly divided as to
their previous exposure, indicating the possible
need for this project and other module develop-
ment efforts to undertake more hands-on and in-
formational/instructional work about the teaching
method. The sophistication of all the respondents
about modules, in response to later questions, was
very high, however; even those who had not used
them could list many alleged benefits and draw-
backs and apparently had some informed basis for
their opinions.
One question asked: "How likely might you be
to use modules such as the one provided and
those listed in the following situations?" Re-
sponses are listed below:


CHEMICAL ENGINEERING EDUCATION











I


Supplement to
Text
Replace Texts
Replace Lecture
Additional
Practice
Remediation
Acceleration
Individualized
Programs
Resource for
Preparing
Lectures

Totals**
Other
(Recertification
(Examination P
1* = Very likely
2* = Perhaps
3* = Not likely
**Totals indical
listed.

J. R. F. Alonso
Computer Science a
Australia. He recei
from Worcester Po


TABLE 1 In general, module users as well as those with-
Likelihood of Module Use out previous exposure held similar opinions, i.e.:
Modules were most likely to be used as supplements
Previous No Prior to texts, for additional practice, for remediation, for
Experience Experience Totals acceleration, and for individualized programs;
1* 2* 3* 1 2 3 1 2 3 0 Modules were not likely to be used to replace texts.
Even more important, in inspecting the data
in this table, is the fact that perceived likelihood
25 6 0 22 3 0 45 9 0 of module use, for the entire range of purposes
0 8 23 0 6 18 0 14 41 listed, is strongly supported both by those with
s 5 14 10 2 10 11 7 24 21 and without previous modular exposure. Without

23 5 3 20. 4 0 43 9 3 saying that modules can be a panacea for all
16 13 2 18 4 3 34 17 5 teaching-learning problems, the respondents were
14 12 4 15 9 0 29 21 4 uniformly and strongly positive about the variety
of applications listed, with the exception of text
18 11 2 12 10 2 30 21 4 replacement.
Other uses which respondents suggested on
1 1 1 18 7 0 19 8 1 their own were the use of modules for recertifica-
tion (or continuing education) and for "stealing"
102 70 45 107 53 34 207 122 78 or "quality preparation" of examinations.
The only area where there was a striking
2) difference between those with module experience
reparation 2) and those lacking it was the item "Resource for
y Preparing Lectures." Those without experience
uniformily felt modules could be a useful resource;
Sl o m u i a those with experience uniformly did not feel they
te likelihood of module use in any way
could be used that way. Further discussion of this
issue indicated that many professors not ac-
quainted with modules had thought the "hour's
is presently lecturing in Chemical Engineering and quainted with modules had thought the "hour's
it Swinburne College of Technology, Victoria 3122, length" could be a pre-packaged lecture.
ved his B. Sc. from Columbia University, M. Sc. The next question involved the preference of
lytechnic Institute and is presently completing his respondents for module availability, allowing for


Ph.D. requirements at the University of Melbourne. Author of the
SIMPLE Suite of Programs and a few papers, his professional experi-
ence also includes two years in the Computer Department of the
M. W. Kellogg Co., one year as an 1. B. M. research assistant at
M. I. T.'s Computer Center, and recently one year leave at the U. of
Houston working with Prof. Henley on Modular Teaching Data Base
Management. (L)
Karen C. Cohen is primarily interested in educational evaluation
and graduate science and engineering. She received her B. A. from
Harvard and M. A. and Ph.D. from Johns Hopkins University. She is
currently on the faculty of M. I. T. with a joint appointment in ChE


and the Div. for Study and Research in Education. Part of her work
involves co-directing Project PROCEED (Program for Continuing Engi-
neering Education). She also directs the Center for Educational Re-
search and Development at WPI. The author of several books of
evaluation strategies and evaluation reports, she was a consultant to
the effort reported here. (C)
Professor Ernest J. Henley has been a professor of chemical engi-
neering at the University of Houston, since 1964. He received his Ph.D.
from Columbia University in 1953 and has been on the faculty of
Columbia University and Stevens Institute of Technology. (R)


SUMMER 1978









only two options: to purchase sets of individual
modules or single modules with reproduction
rights.4 The preference seemed to be for single
copies with rights to reproduce them:
TABLE 2
Ordering Preference
3rd Choice
1st Choice 2ndChoice (other)


Order one copy with
right to reproduce
Order sets
Other


32 8
12 18
2 1


Concomitant with preference for in-house re-
production was the nearly universal (all but 1 re-
spondent) feeling that costs of such reproduction
could be recovered from students. The modal
response was that recovery of costs would be
"fairly easy to do."
TABLE 3
Recovery of Reproduction Costs
N
Cannot 1
Very Difficult 10
Some Effort 16
Fairly Easy 28
Don't Know 2
Other 0
The responses, taken together, while they do
not compare modules with other possible modes
of instruction, seem to indicate that ChE pro-
fessors see modules as an additional, valuable re-
source for a variety of purposes. They would
probably like to own (or have available) the entire
CHEMI set to use when, where, and in those
quantities they see fit. Recovery of in-house re-
production costs does not appear to loom as a large
problem.
When professors were asked to list topics in
addition to those planned for the project which
they would like to see developed, a very small
number of suggestions were made. Generally, the
entire undergraduate field seemed to be considered
covered.
Finally, we were interested in the advantages
and drawbacks respondents saw in modular use
for the student,
for the teacher, and
for the administration.
The most striking finding involved the variety

4Far more detailed questions were asked of college
mathematics instructors regarding such options with re-
sults available privately from William Walton, Director,
Project Calc, EDC, 55 Chapel Street, Newton, Massa-
chusetts.


in the responses. It was nearly impossible to de-
velop meaningful coding categories for these open-
ended questions that would capture, without
forcing, the essence of more than two or three
responses. The complete array of responses to each
item appears below. Probably the most important
result of this survey is the fact that one set of
materials, these single topic CHEMI modules, is
seen as potentially meeting a large number of
diverse needs for a large number of people.
More specifically, the following advantages
were cited:
TABLE 4
Perceived Modular Instructional Advantages
Previous No
Exposure Exposure Total


a) For the Student
Self-pacing 10 9
Motivation 8 1
Acceleration/fuller coverage 5 4
More perceived structure/
better presentation 6 1
Supplement to lectures 3 0
Efficient review/remediation 2 0
Avoid problem of not knowing
prerequisite 2 0
Good introduction 0 2
Same instruction for all 1 0
No lecture requirement 1 0
Easier learning 1 0
Organized to individual needs 0 1
Rich variety 1 0
Easy availability 1 0
Helpful for project work 0 1
Clear definition of objectives 0 1
Better understanding 0 1
Don't have to copy notes 1 0
Make up missed lectures 1 0
Less formal than books 1 0
Minimum cost 1 0
A new way to learn 1 0
TOTAL 47 21
Previous No
Exposure Exposure


b) For the Teacher
Broader coverage
Crutch
More time for 1:1 help
Another view presented
Same presentation to all
students
Course planning aid
Make-up assignments
Back-up, lecture replacement
Remediation
Transfer learning responsibility
to student
Acceleration


19
9
9

7
3
2

2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
68

Total


6
6
5
4

2
2
2
2
2


1 0 1
1 0 1


CHEMICAL ENGINEERING EDUCATION










Extra instruction 1
Less preparation time 1
Cover more effectively 1
More current 1
Turn lectures to discussions 1
Easier feedback 1
Thoroughness 1


TOTAL


Without saying that modules
can be a panacea for all teach
learning problems, the respon
uniformly and strongly positive
the variety of applications list
with the exception of
text replacement.


25 15 40



ing-
dents were
'e about
ed,


Responses regarding administration ad-
vantages were meager, and are not reported for
that reason.
In the same vein, the following disadvantages
were cited:

TABLE 5
Perceived Modular Instructional Disadvantages
Previous No
Exposure Exposure Total

a) For the Student

None 7 6 13
Impersonal (lack of contact
with professor) 3 2 5
Mastery feeling, only crutch 0 3 3
Unfamiliar method 2 0 2
Level of material varies 2 0 2
Without care can become
fragmented 1 0 1
Continuity 1 0 1
Some students go slower 1 0 1
Not every student will succeed 1 0 1
Inconsistent nomenclature 1 0 1
Must include references to
fill gaps 1 0 1
Harder to use as future
reference 1 0 1
Different presentations from
each author 1 0 1
Allows student to procrastinate 1 0 1
"Spoonfeeding" 1 0 1
Poor reproduction 1 0 1
Quality below text 1 0 1
Less interaction 1 0 1
Too many sets of paper,
hard to keep together 1 0 1
Lock & key simplistic approach 1 0 1
More may be expected of
student 1 0 1
Easy to fall behind 0 1 1
Some students respond
negatively 0 1 1

SUMMER 1978


Cost
Faculty use carelessly
TOTAL


b) For the Teacher

None
Modules not synchronized
Modules are a "crutch"
More teaching time, planning
Impersonal
Less chance to explore
Author's personality is
too strong
Too dry
Texts are easier to use
Hard to get all modules to
students
Hard to tell students have
learned
Suppress superiority and
innovation
Danger to expect too much
"Continuous contact with
bitching students"
Lack of contact with students
(if desired)
Hard to tell
Unfamiliar method
Difficult to "time up" the
lectures to program of the
class
May be superficial
Students procrastinate


TOTAL


0 1
0 1
31 15
(-7 (-6
None None
= 24) = 9)


1
1
46
(-13
None
= 33)


12
10
7
3
2
2

1
1
1


1 0 1

1 0 1

1 0 1
1 0 1


30
(-6
None


1
1
1
20
(-6
None


1
1
1
50
(-12
None


= 24) = 14) = 38)


Again, administration drawbacks cited were
sparse and relatively trivial.
These comments indicate that the professors
responding see far more advantages than dis-
advantages to modular use for students. The fact
that the most frequently written "drawback" for
both teachers and students was "None," and far
outweighed any other perceived drawback (except
lack of "synchrony" for those with previous ex-
posure), indicates an openness, interest, and
willingness to experiment with modules. Indeed,
in the general discussion about the CHEMI
Project and the results of the survey, there was
disappointment expressed that the entire set was
not available immediately both for examination
and for use. In addition, the general tenor of the
totally open ended comments (Question 8, other
Continued on page 142.









S*, t. :laboratory




SIMPLE AND RAPID METHOD FOR DETERMINING

THE VAPOR PRESSURE OF LIQUIDS BY GAS

CHROMATOGRAPHY


BERNARD GILOT and RONALD GUIRAUD
Institute du Genie Chimique de Toulouse
Toulouse CEDEX, France

DANILO KLVANA
Ecole Polytechnique de Montreal
Montreal, Canada

CHEMICAL ENGINEERING COURSES, par-
ticularly in the field of transfer phenomena,
include numerous calculations involving many
physico-chemical data. Frequently, such calcula-
tions are designed to solve real industrial prob-
lems. It is not unusual, however, that the required
physico-chemical data are not readily available in
the literature. In these cases the data have to be
either estimated or determined by some suitable
experimental method.
For example, in calculations related to distilla-
tion the student has to evaluate the boiling tem-
peratures of the major components of the mixture
at a given working pressure. For this purpose the
Clausius-Clapeyron or the Antoine equation is
very often used. When the parameters for either
equation are not known, it is advisable to deter-
mine them experimentally by measuring the vapor
pressure as a function of temperature, instead of
using the simple Trouton's rule for which in fact
the data might also be unavailable.
However, among the several experimental
methods commonly used for vapor pressure deter-
mination, only a few could easily be adapted for
undergraduate laboratory courses. Those few,
furthermore, would be rather time consuming.
Therefore to encourage students' interest in ex-
perimental methods and to teach them to seek the
experimental determination of missing physico-
chemical parameters whenever possible, we have
developed a simple and rapid method of vapor
pressure determination. The description of this
method, employing a gas chromatograph is the


subject of the present work. This method was suc-
cessfully adopted for undergraduate laboratory
courses at the Institute du genie chimique de
Toulouse (France) and requires one laboratory
session.

PRINCIPLE OF THE METHOD

A SUITABLE AMOUNT OF a liquid sample of
low vapor pressure is injected into the
chromatograph and completely vaporized at high
temperature. The carrier gas containing the va-
porized sample then passes through an empty
column kept at a temperature below that of the
injection port and below the boiling point of the
sample. On passing through this cooler region, a
part of the sample condenses on the walls, leaving


hi, A 2

n
"Z


T2


FIGURE 1. Detector Response as a Function of Sample
size and Temperature. Temperature T2 > T1; Sample Size
nsl ns2


CHEMICAL ENGINEERING EDUCATION








the carrier gas saturated at the temperature of the
empty column. The sample-free carrier gas mean-
while entering the column becomes saturated on
passing through the tube containing the condensed
sample until the amount injected is completely
taken up. The saturated carrier gas passes
through the detector which monitors the in-
stantaneous sample concentration in the carrier
gas and the total amount of the sample injected.
Thus, the response of the detector is recorded as
an area resembling rectangle (instead of a peak)
whose height depends, for given sensitivities of
detector and recorder, on the concentration of the
sample in the carrier gas i.e. its vapor pressure.
The width of the recorded rectangular area de-
pends on the total amount of the sample injected
(see Fig. 1).
The equations relating the vapor pressure, the
detector response and the total amount of the
sample may be derived as follows.
The partial pressure of a sample Ps can be re-
lated to the pressure of the carrier gas P at the
end of the empty tube by
P" = xP (1)
where x, is the mole fraction of the sample in the
carrier gas.
For very low concentrations, the mole fraction
of the sample in the carrier gas can be approxi-
mated by

n, n, (2)
n, + ne n,
where n. is the number of moles of the sample and
nc is the number of moles of the carrier gas, per
unit volume.
The response of a detector, expressed in terms
of the signal voltage E, is related to the mole frac-
tion of the sample in the carrier gas passing
through the detector and a proportionality con-
stant k by

E=k n- =kx, (3)
nc
The proportionality constant k depends on the
conditions of experiment and can be expressed as
k =C C2 C a (4)
where C, is the recorder sensitivity in mV/cm, C2
is the reciprocal chart speed in min/cm, C, is the
flowrate of the carrier gas in moles/min, and a is
the response area per mole (cm2/mole), i.e. the
ratio of recorded area A to the total number of
moles n. of the sample.


From eq. 3, the unknown value of x, (instan-
taneous mole fraction of sample s) is given by


Expressing E in terms of the recorder sensitiv-
ity C, and the height h of the recorded area, we
have
E=hCC (6)
and x, becomes, from eq. 4, 5 and 6
h C,
hCC (7)
C, C,! C, a
Thus from eq. 1 and 7 the vapor pressure of a


.... to encourage students'
interest in experimental methods and
to teach them to seek the experimental
determination of missing physico chemical
parameters whenever possible, we have developed
a simple and rapid method of
vapor pressure determination.


sample can directly be related to the recorded de-
tector response h as:
h
Ps P (8)
C C23 a

The parameter a = -Ahas to be determined by
n,
calibration.


EXPERIMENTAL
THE PROCEDURE FOR THE experimental
method just described is relatively simple. The
chromatographic column of the apparatus is re-
placed by an empty tube, preferably of stainless
steel (9-12 ft long and 1/8 in diameter). This
tube has to be carefully thermostated and its tem-
perature precisely measured. In our experiments
we used thermocouple. The temperature of the in-
jection port and that of the detector are higher
than the temperature of the empty column; high
enough to assure a complete vaporisation of the
injected sample and to prevent any condensation
on the detector. The flowrate of the carrier gas
has to be kept constant throughout the experiment
and the calibration. It is usually measured in
terms of ml/min by means of a soap-bubble flow-
meter. In this case, the measured volume flowrate


SUMMER 1978


Xs =








C'% is converted into the mole flowrate C, (moles/
min) by using the equation:

C = C" (P-P20) (9)
S R T
where R is the gas constant, Ta is the ambient tem-
perature at which C's has been measured, P20o is
the vapor pressure of water at Ta and P is the
pressure of the carrier gas.
While the parameters C1, C, and C, can be pre-
selected and kept constant for a series of experi-
A
ments, the ratio a = has to be determined by
ns
calibration.
To calibrate the apparatus i.e. to determine a,
a known amount of a sample dispensed from a
syringe (can be determined by weighing) is in-
jected into the system and a corresponding re-
sponse is recorded. The response area is measured
by means of an integrator, or other suitable
method.

RESULTS AND DISCUSSION
T HE MAIN ADVANTAGE of the described
method is its simplicity and relatively short ex-
perimental time. However the method has certain
limitations, and its success depends on the degree
of a dynamic equilibrium achieved in the "cold"
column and on the precision of calibration.
To assure the equilibrium vapor pressure of
the investigated sample, low flowrate of carrier
gas and a relatively long, small diameter column
should be used. The amount of sample has to be
large enough to assure that a substantial portion
condenses in the empty column. However, it is
important that the instantaneous sample concen-
tration in the carrier gas always lies within the
concentration range of the linear response of the
detector. Thus the method is limited to liquids
with low vapor pressures at the temperatures
'used.
For calibration, a wider range of sample size
should be used to verify the constancy of the a
factor.
The vapor pressure data determined at differ-
ent temperatures can be fitted to either the
Clausius-Clapeyron equation:
B
log Ps = A (10)
T
or to the Antoine equation:
B'
log P. = A' = (t = oC) (11)
t+C


depending on the particular liquid.
To verify the method, we have chosen dicyclo-
hexyl and cyclohexylbenzene. For dicyclohexyl the
data were fitted to the Clausius-Clapeyron equa-
tion and the parameters A and B were determined
by using the least squares method:
A = 8.21, B = 2712.8
The correlation coefficient of this fit was r2 =
0.9997. The cyclohexylbenzene data were fitted to
the Antoine equation and the following parameters
were obtained:
A' = 7.562, B' = 2162.0, C = 223.5
In this case the correlation coefficient was r2 =
0.998. These results agree very well with those ob-
tained by other methods [1]. D

REFERENCES
1. J. A. Riddick and W. B. Bunger, "Organic Solvents",
3rd Edition, Wiley-Interscience (1970).


ChE AND MODULAR INSTRUCTION
Continued from page 139.
comments) conveyed general high hopes and ex-
pectations for the project and enthusiastic antici-
pation for its products.

SUMMARY AND CONCLUSIONS
THE BRIEF SURVEY, administered to the
entire ChEd college sponsored by the ASEE
(attended by representatives of most institutes
and universities where ChE is taught), was re-
turned by over 25% of those receiving it. The
survey indicated that participants held a fairly
uniform view of the value of modular materials
for remediation, acceleration, self-pacing, in-
dividualization and more thorough coverage of
topics. In brief, they were thought to be a
marvelous resource. Respondents who had had
previous experience with modular materials
(about 50%) had more specific opinions than
those without such experience (hardly a striking
finding). But the general tone, the serious nature
of the comments, and the thoroughness of re-
sponses indicates a real concern with teaching
effectiveness, and hope and expectation that the
completed set of CHEMI modules will be able to
improve teaching effectiveness in a variety of
ways. O


CHEMICAL ENGINEERING EDUCATION









book reviews

FOUNDATIONS OF CONTINUUM
THERMODYNAMICS
J. J. Delgado Domingos, M. N. R. Nina, J. H.
Whitelaw, eds. Halsted Press, 1973. $29.95
Reviewed by J. C. Melrose, Mobil Research and
Development Corp.
This volume constitutes the proceedings of an
International Symposium on the Foundations of
Continuum Thermodynamics, held in Bussaco,
Portugal, in 1973. Contributors to the proceedings
include many of the most prominent physicists,
chemists, engineering scientists, and applied
mathematicians who have been active in this field
in recent years. A slight majority, perhaps, of the
papers will appeal primarily to those chemical
engineers who adhere to the traditional view of
both equilibrium and non-equilibrium thermody-
namics. According to this view, thermodynamics
provides a framework within which the phe-
nomena of molecular physics are manifested as
relationships among macroscopic parameters. The
remainder of the papers, on the other hand, will
be of primary interest to those who find inspira-
tion in the various degrees of mathematical com-
plexity by which the so-called constitutive relation-
ships of continuum mechanics can be formulated.
Among the contributors who approach the
subject primarily from the point of view of
molecular or statistical theory are Tisza, Callen,
Prigogine, Schlogl and de Groot. The papers by
these authors, along with that by Professor J.
Meixner, a founder of the subject of irreversible
thermodynamics, form the centerpiece of the Sym-
posium proceedings. Protagonists representing the
continuum mechanics point of view include Muller,
Rivlin, Lee, Nemat-Nasser, Mandel and Pina. An
introductory paper by the principal organizer of
the Symposium, Professor Delgado Domingos of
Lisbon, is a noteworthy review of current con-
ceptual problems in the latter field.
An interesting feature of the book is the in-
clusion of five discussion papers, as well as con-
tributions in the form of discussion remarks.
These follow nine of the eleven principal contribu-
tions. A summary paper by P. Germain deals with
what was intended to be a major objective of the
Symposium. This objective was the reconciliation
of the vastly different approaches to the physical
foundations of thermodynamics which are
commonly followed by the practitioners of the
SUMMER 1978


two schools of mechanics: statistical and con-
tinuum. Since Germain is a representative of the
latter school, his desire "to conclude on a peaceful
note" is refreshing.
As may be inferred, this book is not recom-
mended for students who are just beginning a
study of the subject of thermodynamics. On the
other hand, it can be highly recommended to those
who, with teaching responsibilities, are perplexed
by the differing approaches just alluded to. Of
particular value, in the reviewer's opinion, are the
discussion paper and discussion remarks of Pro-
fessor J. Kestin of Brown University. Kestin
points out some common difficulties of a semantic
nature and stresses the importance of using terms
such as thermodynamic state and thermodynamic
process in a precisely defined and consistent way.
For those who may be intrigued by the ap-
pearance of greater generality which is en-
gendered by the mathematical formalism of con-
tinuum mechanics, the two papers by D. G. Miller
of the Lawrence Livermore Laboratory and E. A.
Mason of Brown University are recommended.
Miller's contribution reviews the present status
of the experimental evidence for the validity of
the Onsager reciprocal relations. Miller also dis-
cusses the well-known criticisms of irreversible
thermodynamics by certain practitioners of the
school of continuum mechanics. He concludes that
these criticisms are overstated and issues a chal-
lenge to this school to supply arguments of a
macroscopic nature by which the reciprocal rela-
tions can be derived. Professor Mason in his dis-
cussion paper provides some stimulating argu-
ments to support Miller's challenge and suggests
that the Onsager reciprocal relations be elevated
to the status of a scientific paradigm (to adopt
the terminology of T. S. Kuhn).
As a final comment by one who has attended
several conferences of the syncretistic type repre-
sented by the Bussaco Symposium, this reviewer
would like to put forward the following proposi-
tion. Stated as a theorem of unattainability, the
proposition is that the ostensible objective of such
a conference can never be achieved. The back-
grounds, favorite approaches, and basic interests
of the two schools are ultimately too divergent to
be reconciled. This is not to say that this and
previous conferences have not been highly success-
ful. On the contrary, the proceedings of the
Bussaco Symposium provide a stimulating record
of what was clearly an outstanding meeting, de-
voted to one of the most central subjects in
physical science. E










I book reviews

THEORETICAL RHEOLOGY
Edited by J. F. Hutton, J. R. A. Pearson, and
K. Walters
Halsted Press, Wiley, New York, 1975. ($25.00).
Reviewed by Chris Macosko
University of Minnesota
The last two years have brought a welcome
surge of rheology text books. Messieurs Lodge
(1974), Astarita and Marrucci, (1974) Huigol
(1975) Walters (1975) and Han (1976) have all
contributed recent volumes to the field and several
other authors are preparing new manuscripts.
John Wiley's Halsted Press Division who published
the texts by Huigol and by Walters have also added
a very nice collection of papers in "Theoretical
Rheology." As the title facing page indicates it is
"The Proceedings of the British Society of Rheo-
logy Autumn conference on Theoretical Rheology
held at the University of Cambridge" in fall 1974.
It is not a text book nor is it totally theoretical.
It is a useful rheology reference book and is highly
recommended to libraries and researchers in the
field. It is of course not timeless but a number
of good review-type papers appear in it. It does
have a respectable index. The papers are typeset
and printing quality is good including an ad-
mirable effort at uniformity of notation. Below is
a list of the titles and authors.
Section 1: Converging and Diverging Flow
1. Creeping Flow of a Viscoelastic Liquid Through a
Contraction: A Numerical Perturbation Solution.
Jesse R. Black, Morton M. Denn and George C. Hsiao.
2. Deceleration of Viscoelastic Liquids. A. L. Halmos and
D. V. Boger.
3. Plane Entry Flows of Viscoelastic Fluids. S. Zahorski.
4. Stability and Overstability of the Plane Flow of a
Simple Viscoelastic Fluid in a Converging Channel.
Karl Strauss.
5. Hydrodynamic Factors Affecting the Growth of
Fibrous Crystals of Extended-Chain Polymers. M. R.
Mackley.
Section 2: Thermomechanics
6. The Thermomechanics of Materials with Fading
Memory. R. S. Rivlin.
7. Rheological Equations of State and Thermodynamic
Principles. J. G. Oldroyd.
8. A Non-Isothermal Theory of Viscoelastic Materials.
Marcel J. Crochet.
9. Thermomechanics of Compressible Materials with
Entropic Elasticity. Gianni Astarita and Giulio Cesare
Sarti.
Section 3: Composites and Suspensions
10. Finite Deformations of Strongly Anisotropic Ma-
terials. Tryfan G. Rogers.


11. Balance Laws for Mixtures of Granular Materials.
S. L. Passman.
12. Mechanical Properties of Semicrystalline Polymers Re-
garded as Composite Materials. J. L. Kardos, J. C.
Halpin and L. Nicolais.
13. The Mechanics of Fluid Suspensions. E. J. Hinch.
14. The Effect of the Non-Newtonian Properties of a
Suspension of Rod-like Particles on Flow Fields. J. G.
Evans.
Section 4: Rheometry
15. Progress in Experimental Rheology.
16. The Start-up of Steady Elongational Flow of Visco-
elastic Materials. M. C. Phillips.
17. Some New Validity Tests on the Bird-Carreau Type
Constitutive Equations. H. E. van ES, H. A. M. van
Eekelen and M. C. Phillips.
18. The Theory of a Universal Oscillatory Rheometer for
the Study of Linear Viscoelastic Materials Using
the Principle of Normalised Resonance. M. Sherriff
and B. Warburton.
19. Correlations Between Linear and Non-Linear Visco-
elastic Data for Polymer Solutions. B. Hlavacek and
P. J. Carreau.
20. The Effect of the Non-Newtonian Properties of
Polymer Solutions on Flow Fields. Gianni Astarita
and Morton M. Denn.
21. Report of the Discussion. J. F. Hutton.



[]NP s news


JOHN QUINN RECEIVES BENT PROFESSORSHIP
John A. Quinn, Professor of Chemical and
Biochemical Engineering at the University of
Pennsylvania, was recently named to be the first
recipient of the Robert D. Bent Professorship.
The Professorship was established by a $1,000,000
grant from the Atlantic Richfield Foundation to
honor Mr. Bent who retired recently as President
of the ARCO Chemical Co. and Senior Vice Presi-
dent of the Atlantic Richfield Co.
Professor Quinn earned his bachelor's degree
in chemical engineering from the U. of Illinois in
1954 and his doctoral degree, also in chemical
engineering, from Princeton U. in 1959. He joined
the faculty of Chemical and Biochemical Engi-
neering at the U. of Pennsylvania in 1971 after
having been a member of the chemical engineer-
ing faculty at the U. of Illinois for 12 years. His
research interests focus on interfacial phenomena,
problems related to transport through mem-
branes, and bioengineering. Professor Quinn was
recently recognized for his distinguished academic
career in chemical and biochemical engineering
by being named to membership in the National
Academy of Engineering.


CHEMICAL ENGINEERING EDUCATION











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