United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Research Triangle Park
North Carolina 27711
f/EPA
Research for
Particulate Control
EPA's Mobile Test Vans
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Finding Better Ways
To Control
Participates
This year, industries and utilities in the
United States will spend close to a
billion dollars on devices to control
particulates.
Unfortunately, millions of dollars of
this money will be spent to improve
control devices that have already been
installed. If more information was
available about how particulate collec-
tors operate on specific process equip-
ment, a good deal of this money could
be saved. But site-specific information
on full-scale particulate control devices
is hard to obtain.
Because particles can behave unpre-
dictably, a control device that works
fine at one plant may be only marginal-
ly efficient at another. Even where the
processes are similar, differences in
temperature, pressure, or the chemistry
of fuels can drastically alter collector
efficiency. Because of the lack of site-
specific information, many utilities and
industries invest in larger, more expen-
sive particulate control devices than
they need. Or — even worse — in an
inadequate system that can't bring the
plant into compliance with regulatory
standards.
To help solve this problem, the
Environmental Protection Agency has
developed three mobile particulate
collection vans.
Each van houses a pilot-scale version
of a conventional control device —
fabric filter (baghouse), wet scrubber, or
electrostatic precipitator (ESP). The
vans are based at EPA's Industrial
Environmental Research Laboratory in
Research Triangle Park, North Carolina.
From there, they travel to factories and
power plants all over the country to
collect performance data.
This data helps both industry and
EPA. It gives industry facts and figures
on how to buy and install more efficient,
cost-effective particulate control equip-
ment. And it gives equipment manu-
facturers and EPA information on how
to design better particulate control
devices for the future — for conven-
tional as well as alternate fuels and
processes.
Many utilities and industries have
hosted the mobile vans since the pro-
gram was begun in 1973. In doing so,
they have contributed to research that
will give America the energy it needs,
without polluting our environment.
In the following pages, you'lt find a
complete explanation of what's involved
in hosting a mobile particulate control
van at your plant — including specifica-
tions for installation and operation of
the equipment.
If you're interested in taking pan in
the program — or if you'd simply like
more information — please contact:
James Turner MD-61
Particulate Technology Branch
Mobile Collectors
Industrial Environmental
Research Laboratory
Research Triangle Park,
North Carolina 27711
(919) 541-2925
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The Mobile Vans
Since 1973, EPA's mobile vans have
tested the performance of paniculate
control devices at a wide variety of
sites, from a 2400-megawatt generating
station in Page, Arizona to a pulp mill
in Plymouth, North Carolina. The
operating crews are experienced in all
phases of particutate sampling. Both
the sampling methods and hardware
they use are constantly updated to
maintain state-of-the-art operation.
From the stack breeching to the trailer
outlet duct, each van is a self-contained
unit with closely controlled operating
parameters. Because many of the
factors that affect collector performance
and particulate measurement are under
control, test conditions can be varied.
And they can be reproduced until
meaningful results are obtained.
The mobile particulate vans are a
good example of how both government
and industry can benefit from a co-
operative program. Plant managers can
use the information generated at an
on-site test to save money on initial
installation or retrofitting of existing
equipment. And data we have on how
today's particutate control devices work
under different conditions will help in
the development of improved control
equipment for the years ahead.
In addition, through EPA publications,
the information the vans collect is made
available to a wide audience in govern-
ment and industry.
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One of many places EPA's mobile
vans have helped is the Salt River
Project. Since 1977, EPA and the Salt
River Project have cooperated to find
ways of improving the efficiency of
electrostatic precipitators on coal-fired
plants. In 1978, the mobile ESP came
to the company's Navajo generating
station, and the crew spent the summer
conducting an extensive test program to
find the most effective control equip-
ment and procedures. The Salt River
Project will use the data collected to
help design more effective control
devices. And the test results will be
helpful to other utilities using hot-side
ESP's to control participate emissions
from low-sulfur coals.
Participating Companies
Weyerhauser Corporation
Pennsylvania Power and Light
City of St. Louis
Union Electric
Mailman Foundry
Maryland Department of
General Services
Montana Power Company
Basin Electric Power Cooperative
Salt River Project
Michigan State University
Monongahela Power Company
Southwestern Public Service Company
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The Mobile Van
Test Program
Pn»-Survey
The first step in a test program is the
pre-survey. Here, you'll sit down with
EPA representatives to discuss the
program from beginning to end. To-
gether, you'll work out the arrangements
for the installation and operation of the
mobile vans. During this meeting, EPA
will brief your plant personnel about
the crew's experience, and let everyone
know in advance what assistance will
be required from the plant. By the end
of the pre-survey, everyone involved in
the test program will have a clear idea
of exactly what to expect.
Test Plan
After the pre-survey, EPA will draw up a
detailed plan for each stage of the test
program and submit it to you for ap-
proval. A typical program lasts between
one and three months.
Installation
Insulated stainless steel ducting is used
to connect the mobile particulate
control devices to the process flow.
Your plant personnel normally specify
the route for this ducting and associated
support hardware.
Because the best place for an access
port is sometimes 150 feet up in the
air, a crane and rigging crew may need
to be hired from a local contractor.
This contractor also usually fabricates
the duct supports.
The process end of the duct is con-
nected to a probe inserted into the gas
stream. EPA supplies the probe.
Cutting an access port and securing the
probe is generally handled by your
plant personnel, so that it can be
scheduled during a shutdown. The
installation requires some welding.
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Operation
Once a mobile van is up and running,
very little effort is required on the part
of your plant personnel. Almost all
work is done by the EPA crew in the
immediate area of the van, without
interfering with your operation.
During testing, the engineer in charge
of the mobile van usually requests
information about various process
parameters. This data is important in
evaluating control device performance.
Inlet and outlet grain loadings and
particle size distributions are usually
available within 48 hours after a sample
is taken. This means the EPA crew can
fine-tune the test program while it's in
progress.
Since data collected by the different
mobile vans are directly comparable, it
may be advantageous to test the same
process with two vans at the same
time. This can be done with very little
additional hardware or installation time.
Post-Test Procedures
The ash or sludge from the mobile
control devices is dumped in 55-gallon
drums. These drums are handled with
a forklift, usually provided by your
plant. Since full drums are moved only
a few times during most programs, this
does not require much time or effort.
When testing has been completed, a
contractor is usually called in again to
remove ducting. The slipstream port is
capped and the duct is loaded into the
vans. Then the crew heads home, for
maintenance, or directly on to the next
test site.
Test Results
The data collected during a test pro-
gram are sent to EPA's Industrial
Environmental Research Laboratory
(IERL) in Research Triangle Park, North
Carolina. There, the data are evaluated
and become part of the statistical base
for lERL's particulate control device
analyses. Test results are also incor-
porated into other EPA particulate
control programs.
A summary of the test data is also
sent to your plant, where it should be
valuable in improving the efficiency of
existing particulate control equipment or
in deciding what new devices best fit
your process.
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Mobile Baghouse
EPA's mobile baghcwjse is equipped to
investigate all major factors that affect
the collection performance of a fabric
filter device.
The mobile baghouse can be adapted
to bag cleaning in three different modes:
shaking, pulse jet, or low-pressure
reverse flow. Cleaning parameters like
duration, pressure, and frequency can
be varied over a broad range. To better
simulate realistic conditions, the bag-
house can be run 24 hours a day
during a test program.
During May, June, and July of 1977,
the mobile baghouse tested at the
Southwestern Public Service Company
power plant in Amarillo, Texas. The
objective of this program was to charac-
terize baghouse operation and particle
collection capabilities on a utility boiler
burning pulverized Western coal. A
companion study was conducted during
the winter of 1977-78 at the Michigan
State University power plant in East
Lansing, Michigan. These two studies
have provided data for a comparison of
baghouse performance on boilers firing
Eastern and Western coal.
The baghouse has also tested on
effluents from a brass and bronze fac-
tory, a hot-mix asphalt plant, a utility
boiler burning anthracite coal, a pulp
mill lime recovery boiler, and the St.
Louis refuse processing plant.
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1 0
oe
06
04
02
01
008
006
004
002
28 g.cm'
-
i bags
T«flon/glta* (hike
Graphite'glas* shake bags
Tetion/glasi reverse air bags
Graphite/glats reverse air bags
I I I I I I I I I I
I I 1 I
01 0.2 0.4 0.60.81.0 2.0 40 6080
Geometric Mean Particle Diameter, pm
Mobile Baghouse Test
Amanllo, Texas
Mobile Baghouse Specifications
General
Equipment Size
Flow Capacity
Power Requirements
Operating Temperature
Pressure Drop
Bag Face Velocity
Number of Bags
Bag Length
Bag Diameter
Bag Cleaning
40 ft x 8 ft trailer
50-150 acfm
240 V, 150 amp 3 phase or 480 V, 75 amp 3 phase
Ambient to 550°F
0-20 in. of water
0-20 fpm
1-7
4-10 ft
4-12 in.
Shake, reverse flow, pulse jet
Ducting
Pipe
Pipe and Flange Material
Weight
Section Lengths
90° Elbow Radius
Insulation
2.5 in. O.D., Schedule 5
Type 316 stainless steel
2 Ibs/ft
8. 10, 20 ft
5 in.
1 in. fiberglass
Designed by:
GCA Corporation
Built by:
GCA Corporation and
Monsanto Research Corporation
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Mobile Wet
Scrubber
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The mobile wet scrubber is equipped
with a pilot-scale venturi and a pilot-
scale sieve tray scrubber. Both types
are built into the van so that side-by-
side comparisons can be made of their
collection efficiency for many different
processes.
Other flexible parameters in the
design of the van make it possible to
evaluate the effects of liquid-to-gas
(L/G) ratios, pressure drop, venturi
throat velocity, and sieve tray hole sizes
on particle collection efficiency.
Since its delivery in December 1975,
the mobile scrubber has participated in
testing programs at Pennsylvania Power
and Light Company's Sunbury genera-
ting station, at a pulp mill lime recovery
boiler, an iron foundry cupola furnace,
and a small utility boiler.
Mobile Scrubber Specifications
General
Equipment Size
Flow Capacity
Power Requirements
Operating Temperature
Pressure Drop
Liquid-to-Gas (L/G) Ratio
Venturi Throat Size
Venturi Throat Velocity
Number of Sieve Trays
Sieve Tray Perforation Size
40 ft x 8 ft trailer
200-600 acfm
240 V, 200 amp 3 phase or 480 V, 100 amp 3 phase
Ambient to 900°F
0-100 in, of water
5-50 gpm/103 acfm
1.38, 2.36, 3.34 in.
100-400 fps
4
0.125, 0.188, 0.250 in.
Ducting
Pipe
Flanges
Pipe and Flange Material
Weight
90° Elbow Radius
Insulation
6 in. O.D., Schedule 5
6 in. 150 #
Type 316 stainless steel
3 Ibs/ft
10 in.
1 in. fiberglass
Designed by:
Air Pollution Technology, Inc.
Built by:
Naval Surface Weapons Center
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Mobile Electrostatic
Precipitator
The mobile electrostatic precipitator
(ESP) and control and laboratory facili-
ties occupy two 40-foot trailers. Five
precipitator sections, or cells, are
located in the process van, along with a
3000 acfm industrial blower and a dust
conveyance system. All process con-
trols, monitors, recorders, and the power
distribution center are in the laboratory
trailer.
Flexible operating parameters for the
ESP include gas velocity, collector plate
area, current density, periodicity and
intensity of plate and corona frame
rapping, and corona wire diameter and
spacing.
At test programs in Montana, North
Dakota, and Arizona, the mobile ESP
has been used to investigate the effect
of flyash conditioning agents on ESP
performance. In these programs, pre-
cipitator parameters were held constant
while conditioning agents were varied in
type and amount. Tests at Colstrip,
Montana showed that the injection of
sodium carbonate into the slipstream
produced a 12Vi percent improvement in
collection efficiency for particles smaller
than half a micron and reduced particu-
late emission levels from 0.12 down to
0.036 Ibs/MBtu.
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so
40
30 -
20 -
1 0
09
08
07
06
Oft
0.4
0.3
02
Q With Sodium
Carbonate Conditioning
s\ Without Sodium
Carbonate Conditioning
Mobile ESP Specifications
J L
J_J_
J
50 60 70 BO 90 95 98 99 998 999 9999
Precipitatof Efficiency, %
Results from Mobile ESP
Colstrip, Montana
General
Equipment Size
Flow Capacity
Power Requirements
Operating Temperature
Operating Voltage
Collection Plate Area
Number of Fields in Series
Two 40 ft x 8 ft trailers
1000-3000 acfm
• 240 V, 175 amp 3 phase or 480 V, 90 amp 3 phase
• 240 V, 100 amp single phase with neutral wire
for 120 V service
Ambient to 900°F
20 to 50 kV
480 ft2
2-5
Ducting
Pipe
Flanges
Pipe and Flange Material
Weight
Section Lengths
90° Elbow Radius
Electric Heat Load
Insulation
10.5 in. O.D., Schedule 5
10.5 in., 150 #
Type 316 stainless steel
35 Ib/ft (fabricated)
20, 8 ft
15 in.
150 watts/ft
3 in. mineral fiber mat
'/2 in. glass fiber mat
Ve in. aluminum sheathing
Designed by:
Southern Research Institute
Built by:
Naval Surface Weapons Center
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Your Support
Counts
That's the mobile van story to date.
Expert engineers and technicians,
accurate measurements, unique pilot-
scale equipment. Easy installation and
removal. The test planning and data
evaluation resources of the Industrial
Environmental Research Laboratory.
What makes it all work are companies
who are interested in the kinds of
questions the vans are designed to
answer. With the support of utilities
and industry, the EPA mobile particulate
control program has succeeded in pro-
viding valuable data. We hope your
company has a place in continuing that
success.
Prepared by Acurex Corporation under
EPA contract. Photos courtesy of
Acurex Corporation, Envirotech Cor-
poration, Monsanto Research Corpora-
tion, U.S. Environmental Protection
Agency, and the U.S. Navy,
This report has been reviewed by the
U.S. Environmental Protection Agency
and approved for publication. Mention
of trade names or commercial products
does not constitute endorsement or
recommendation for use.
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