United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S8-85/025 Feb. 1986
Project Summary
Microcomputer Programs for
Paniculate Control
M. K. Owen and A. S. Viner
The growth of the microcomputer
industry has made it possible for anyone
to have a relatively fast and easy-to-use
computer. Unfortunately, the special-
ized software needs of the air pollution
community have not been met. In an
attempt to address this need, the Re-
search Triangle Institute, under contract
to the USEPA, has developed a set of
programs especially for air pollution
problems. User benefits, hardware/
software requirements, and brief de-
scriptions of the theoretical models are
given in the report. A sample problem,
which gives detailed instructions, is
included for each program.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
Microcomputers are beginning to ap-
pear in the offices of engineers and
scientists. The tasks of data management
and word processing are now routine.
One area in which microcomputers have
not been heavily employed is modeling.
This is largely due to limited memory
capacity and speed. The strong points of
microcomputers, small size and manage-
ability, can be exploited in making easy-
to-use programs. This potential can be
used to produce simplified models for air
pollution control research. These pro-
grams can provide a fast and easy means
to test different strategies before going on
to run more complex models. In this way,
a microcomputer does not eliminate the
need for a mainframe but serves to make
more efficient use of it. An hour spent
using a simple model on a microcomputer
can save the researcher many hours of
valuable time.
Programs have been developed for
modeling electrostatic precipitator (ESP)
performance, predicting stack opacity,
and predicting the opacity of detached
plumes. In addition, the GCA/EPA bag-
house model has been modified to run on
a microcomputer. In order that these
programs be convenient and easy to use,
a great amount of effort has been invested
in their development and documentation.
All of the programs use a menu format for
program execution and data entry, and
default values are supplied. Input param-
eters can be stored in disk files or listed on
a line printer. The program printouts are
formatted for clarity.
Discussion
This report describes five programs
(Table 1) available for use with the TRS-
80 microcomputer. In order to make them
more available, four have been converted
to run on an IBM-PC. (The minor differ-
ences in versions are covered in an
Appendix.) User benefits, hardware/
software requirements, and brief descrip-
tions of the theoretical models are given.
Table 1. Microcomputer Programs for the
TRS-80
ESP Section Failure Model"
ESP Dynamic Display Model
GCA/EPA Baghouse Model"
Plume Opacity Prediction Modef
In-Stack Opacity Calculator*
"Also available for the IBM-PC.
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A sample problem, which gives detailed
instructions on howto usethe menusand
obtain desired results, is included for
each program.
The ESP Section Failure Model calcu-
lates the steady state emissions from
each section of an ESP as well as stack
opacity. The program can estimate the
effect of non-idealities such as gas sneak-
age, rapping reentrainment, electrical
failures, and maldistribution of gas veloc-
ities. The weakness of the program is that
it is not as accurate as a mainframe
model, but it is much more convenient
and easy to use.
The ESP Dynamic Display Model pre-
sents a real-time simulation of an ESP.
The program includes the effects of
sneakage and rapping reentrainment
while showing the effects of the rapping
schedule on instantaneous and average
opacities and emissions. This program is
suited for a microcomputer because it
uses a simple model and relies heavily on
user interaction.
The GCA/EPA Baghouse Model is a
microcomputer version of a mainframe
model of fabric filter performance devel-
oped by GCA Corporation that uses
modeling baghouses with glass-fiber
fabrics. The program predicts instantan-
eous and cycle-average emissions and
tube-sheet pressure drops. The advan-
tage of this program is that, although
slower, it is easier to use than the main-
frame version.
The In-Stack Opacity Model predicts
the opacity that would be measured by a
transmissiometer in a stack. It performs a
rigorous calculation of the in-stack opacity
based on particle size distribution. The
results of this program are more accurate
than the approximate results provided by
the ESP models. This program provides a
number of options for calculating the
particle light extinction efficiency factors,
depending on the desired degree of
accuracy. In general, the quality of the
predicted results will be limited only by
the quality of the available particulate
data.
The Plume Opacity Model predicts the
opacity of a plume of stack gas as it travels
from the stack exit and mixes with the
atmosphere. This program is useful for
predicting the presence of a condensing
plume based on the stack gas and ambient
conditions. The program implementation
of the model is relatively fast and thus it
has not been run on a mainframe com-
puter.
This report lets the user determine if
his machine can use the individual pro-
gram. The descriptions of the theoretical
models provide an introduction to the
programs. References are given for those
who wish in-depth information. Sample
problems are provided to walk the user
through a typical case. Instructions are
given on howto use the menus and which
options give what results. Printouts of the
screen appearance at various points are
provided to check for correct use. Print-
outs are also available so that the user
can check program results.
Conclusions and
Recommendations
Microcomputers are rapidly becoming
standard tools. However, the air pollution
community suffers from a lack of con-
venient and useful software. These pro-
grams should be a first step in meeting
those needs. Future plans include devel-
oping these programs into an integrated
package such that input data can be
shared by all programs and the output
from a control device program can be
directly read into one of the opacity
programs. Standardized menus will also
be adopted.
M. K. Owen and A. S. Viner are with Research Triangle Institute, Research
Triangle Park, NC 27709.
Leslie E. Sparks is the EPA Project Officer (see below).
The complete report consists of the following:
"Microcomputer Programs for Particulate Control," (Order No. PB 86-146
529/AS; Cost: $28.95, subject to change)
"Microcomputer Programs for Particulate Control: Section Failure, Baghouse,
Plume Opacity Prediction, and In-stack Opacity Calculator (4 Disks),"
(Order No. PB 86-146 51 I/AS; Cost: $120.00, subject to change)
The above report and disks will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S8-85/025
0000329 PS
U S EHVIR PROTECTION AGENCY
REGION 5 LIBRARY
230 S OfARSORH STREET
CHICAGO It 40604
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