Session 3213
Improving Critical Thinking and Creative Problem Solving
Skills By Interactive Troubleshooting
Nihat M. Gurmen1, John J. Lucas2, R. Dean Malmgren1, H. Scott Fogler1
1
Department of Chemical Engineering
2
Department of Electrical Engineering and Computer Science
The University of Michigan
Ann Arbor, MI 48109-2136
Abstract
In today’s job market it is becoming increasingly important to demonstrate one’s
critical thinking and creative problem solving skills in addition to the traditional
engineering knowledge. One effective method for improving these skills involves the use
of interactive computer modules. Particularly, the simulation of faulty operation has also
the advantage of adding uncertainty of industrial settings.
Interactive computer modules that concentrate on troubleshooting help students to
adopt strategies to deal with the inherent ambiguity in open ended problems, and see
some general trends in the creative problem solving process. Interactive computing can
greatly facilitate the learning of troubleshooting skills because of the rapid feedback, the
alternate pathways the student may progress and the multiple solutions they can generate.
Complementary to the traditional classes, interactive computer modules enable the
students to create various what-if scenarios and to concentrate on critical thinking. Hence,
interactive computer modules give students the opportunity to practice in divergent
problem solving skills where there are multiple pathways to the correct solution.
Furthermore, with these what-if scenarios they are able to look at the system from a
broader perspective with the premise that it gives a deeper understanding of the technical
concepts.
This work will demonstrate one of the interactive computer modules developed at
University of Michigan for troubleshooting, MicroPlant. This interactive computer
program simulates the faulty operation of a micro-plant in which ethyl benzene is
converted to styrene. It contains over forty possible faults, two of which are assigned
randomly when the student signs on to the program. The program is designed to
encourage the student to troubleshoot the plant with critical thinking skills in situation
and decision analysis.
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
Introduction
In this study, the computer simulation of a faulty styrene plant will be introduced
as a tool for stimulating critical thinking and creative problem solving skills in
undergraduate chemical engineering students. The simulation is built as an interactive
computer module (ICM) for a PC with Windows® operating system. As the name
implies, the flows and unit sizes in MicroPlant are small compared to their industrial
counterparts.
To complete the ICM successfully, a good technical background in chemical
engineering unit operations is necessary. However, the simulation is primarily designed
to emphasize the critical thinking and creative problem solving skills in the context of
troubleshooting of a basic chemical engineering plant, MicroPlant. The students may
develop their own strategies to determine the faults and take corrective action or opt for a
well established problem solving methodology like Kepner-Tregoe Situation and
Decision Analysis2 or McMaster Five-Point Strategy3. Fogler and LeBlanc provide an
efficient review for these and other problem solving strategies1.
A full run of the ICM should take about 45 to 60 minutes. Although little or no
calculations should be necessary, a pencil, a calculator, and paper may be necessary to
check some of the mole/mass balance calculations and take notes. Heat effects need to be
considered qualitatively for troubleshooting the MicroPlant. There are no calculations for
students to carry out that would involve any energy balances for the units.
Program description
The MicroPlant ICM simulates a plant in which ethylbenzene is converted to
styrene. The plant consists of nine main units: two preheaters, a reactor, a condenser, a
liquid-gas separator, a liquid-liquid separator, two adsorbers, and a distillation column.
There are also auxiliary units such as tanks, pumps, and controllers. The process flow
sheet of the plant is shown in Figure 1.
Figure 1. Process flow sheet of MicroPlant
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
When a user signs on, the program randomly selects two out of the 42 possible
faults for that particular run. These faults are compiled from real world industrial
operations. The user’s task is to find the faulty equipment(s) and identify what the faults
are. For example, the sets of potential faults in the feed and preheater subsystem, and the
reactor are listed in Table 1 and Table 2, respectively. Appropriate faults are present for
other units and streams of the MicroPlant as well.
Table 1. Five faults that can occur in the feed and preheater subsystem
1
Water pump calibration is off – too much water is delivered.
2
Ethylbenzene pump calibration is off – too much water is delivered.
3
Ethylbenzene pump calibration is off – too little water is delivered.
4
Impurities in water feed.
5
Impurities in ethylbenzene feed.
The overall process flow sheet shown in Figure 1 does not include detailed
information in order to minimize the screen clutter. However, the different subsystems of
the MicroPlant are highlighted as the user moves the mouse on the main flow sheet from
one subsystem to the other. If one clicks on a specific subsystem, the corresponding
detailed screen comes up. For example, Figure 2 shows the detailed view of feed and
preheater subsystem. When the detailed subsystem screen comes up, first, all hot regions
a user can explore are highlighted to visually direct the user. In summary, in the feed
subsystem, the preheaters receive the input from two feed tanks. Two pumps and their
respective control elements push the feed through preheaters 1 and 2.
Table 2. Eleven faults that can occur in the reactor subsystem
1 Channeling in the reactor.
2 Dead space in the reactor.
3 Excess axial spreading in the reactor.
4 Organic chlorides in the water feed are poisoning the catalyst.
5 Organic chlorides in the ethylbenzene feed are poisoning the catalyst.
6
Chlorides are present in the catalyst but not in the feed.
(previous poisoning the catalyst)
7 Catalyst is old.
8 Coking of the catalyst.
9 No catalyst is present.
10 Relief valve on reactor is leaking.
11 Valve downstream of reactor is closed.
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
Figure 2. Process flow sheet of MicroPlant in the feed and preheaters subsystem
The user is given a limited amount of money to be spent on diagnosing the
malfunctions. The limited resource is intended to encourage the user to plan the diagnosis
carefully. The user is therefore charged a fee for each diagnostic technique. A list of
diagnostic techniques for the second heater in the feed and preheater subsystem is shown
in Figure 2. Similarly, Figure 3 shows the diagnostic techniques available for the reactor
subsystem. Appropriate diagnostic techniques are available for all the other units as well.
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
Figure 3. Diagnostic techniques in the reactor subsystem.
The program provides background information on the MicroPlant, as well as
expected and actual output values for streams 5, 7, 10 and 11 shown in Figure 1 for free.
In all other streams, temperature, molar flow rate, and molar composition can be
measured for a fee as shown in Figure 4. These stream values may be used to check if the
mole balance is holding for a unit; a difference may indicate that you found a leak in that
equipment. For the reactor, a mass balance is more appropriate and therefore all
molecular weights for the components are included in the background information.
Discussion
The MicroPlant program is designed to increase the user’s skills in many aspects
of the problem solving - from initial definition of the problem to the final check of the
solution. However, the assessment and evaluation process that would determine to what
degree this goal is achieved seems to be a real challenge. For now, the program returns an
encoded performance number to the student upon exiting the simulation. The
performance number has information about the user’s performance and the money left in
the account. These performance numbers are found to be helpful in situations where the
simulation is assigned as a homework problem. To assess the true educational value of
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
the simulation, it is planned to combine the performance numbers with before-and-after
surveys to come to a more definitive answer.
Figure 4. Process flow sheet of MicroPlant in the reactor subsystem
Acknowledgements
The authors would like to acknowledge the early work and the unpublished
reports of Hsieh, T. Y., LeBlanc, S. and Heil, A. T. and the valuable comments of
Waisanen, J. T on MicroPlant.
The funding of this project is provided by NSF (Grant: DUE-0126497).
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education
References
1.
Fogler, H. S., and S. E. LeBlanc, “Strategies for Creative Problem Solving”, Prentice Hall PTR,
Englewood Cliffs, New Jersey (1995).
2.
Kepner, C. H., and B. B. Tregoe, “The New Rational Manager”, Princeton Research Press, Princeton,
New Jersey (1981).
3.
Woods, D.R., “A Strategy for Problem Solving”, 3rd ed., Department of Chemical Engineering,
McMaster University, Hamilton, Ontario (1985).
Nihat M. Gürmen received his B.S. degree in chemical engineering from Bogazici
University, Istanbul, Turkey. He received the M.E. and the Ph.D. degrees in chemical
engineering from the University of South Florida, Tampa. He is currently a postdoctoral
research fellow at the University of Michigan, Ann Arbor. His research interests include
numerical modeling and simulation of physiological systems; critical thinking and
creative problem solving techniques with interactive computing.
John J. Lucas is currently working towards his B.S.E. in Computer Science at the
University of Michigan, Ann Arbor. In addition to programming for fun, he enjoys swing
dancing and playing racquet ball.
R. Dean Malmgren is majoring in Chemical Engineering and Mathematics at the
University of Michigan, Ann Arbor. He enjoys golf, water polo, and triathlons. His
academic interests include catalysis and modeling.
H. Scott Fogler is the Vennema Professor of chemical engineering at the University of
Michigan, Ann Arbor. He has graduated 30 Ph.D. students from his research group and
has published more than 180 research publications. His research topics include: flow,
reaction, precipitation; kinetics of wax deposition; fused chemical reactions; gellation
kinetics; asphaltene characterization and remediation; colloidal phenomena; catalyzed
dissolution of minerals; pharmacokinetics of acute toxicology; critical thinking and
creative problem solving.
Proceedings of the 2003 American Society for Engineering Education Annual Conference &
Exposition Copyright © 2003, American Society for Engineering Education