SEPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/8-79-031b
December 1979
Research and Development
Particulate Control
Highlights:
Research at High
Temperature/Pressure
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the SPECIAL REPORTS series. This series is
reserved for reports which are intended to meet the technical information needs
of specifically targeted user groups. Reports in this series include Problem Orient-
ed Reports, Research Application Reports, and Executive Summary Documents.
Typical of these reports include state-of-the-art analyses, technology assess-
ments, reports on the results of major research and development efforts, design
manuals, and user manuals.
EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/8-79-031b
December 1979
Partsculate Control Highlights:
Research at High Temperature/Pressure
by
Dennis C. Drehmel and James H. Abbott
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
Program Element No. EHE624A
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
-------
ABSTRACT
Although particulate control equipment can be demonstrated to have
high collection efficiency in some applications, extreme conditions of
temperature, pressure, or both pose special problems. Aqueous scrubbers
and filters using organic media have obvious temperature limitations.
Electrostatic precipitators (ESPs) are commonly used on the hot side of
the air preheater in power plants but performance at high temperatures
such as 800°C is yet to be demonstrated. The need for control at extreme
conditions arises in metallurgical operations and advanced energy processes
Consequently, EPA has conducted a program of research and development
for control of particulates at high temperature and pressure.
Among the control devices given consideration in the program were
cyclones, granular bed filters, dry scrubbers, molten scrubbers, ESPs,
ceramic bag filters, and other ceramic filters not of a bag configuration.
Advantages and disadvantages of these devices involve parameters such as
simplicity of operation, materials problems, inability to collect submicron
particles, difficulty in regenerating the collection media, and those
related to cost, including size and pressure drop. Since these advantages
and disadvantages can be weighed differently according to the needs of a
specific application, it is not possible to give universal conclusions.
However, if the most important consideration is control of submicron
particles, ceramic filters are foremost.
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CONTENTS
Page
Abstract ii
Figures iv
Tables iv
Introduction 1
Granular Bed Filters (GBFs) and Dry Scrubbers 3
Ceramic Filters 9
Electrostatic Precipitators 14
Cyclones 14
Summary 15
References 18
Bibliography 19
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FIGURES
No. Page
1 High Temperature/Pressure Control 2
2 Rexnord Filter 4
3 Ducon Filter 5
4 Detail of Ducon Filter Using Screens 5
5 Combustion Power Filter 6
6 Detail of Collecting Bed in CPC Filter 7
7 Ceramic Bag Test Module at Exxon 11
8 Detail of Saffil Alumina Ceramic Bag 12
9 Close-up of Bag Showing Vacuumed Strip 13
TABLES
No. Page
1 Summary of Performance Information 8
2 Comparison of High Temperature/Pressure Control Devices 17
iv
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Introduction
The Environmental Protection Agency (EPA) and its predecessor
organizations have actively investigated improvements in airborne participate
control for 10 years. Five years ago it was recognized that extending
the operating range of conventional devices to high temperature and high
pressure (HTP) would be necessary to provide abatement for a variety of
industrial and advanced energy sources such as fluidized bed combustors
and coal gasifiers. In addition it was recognized that stationary fuel
combustion was the largest source category for particulate emissions/ '
Consequently, EPA focused its programs on fuel combustion and especially
on power production and energy conversion.
The objective of these programs was to demonstrate control technology
to meet environmental standards concerning the ambient concentration of
particles and the emission rate of particles from new sources. The
current standard for power conversions states that new source shall not
emit more than 0.1 pounds of particulate matter for every million Btu's
of thermal energy released (43 ng/J). It is expected that this standard
will be lowered and future ambient air standards may apply to particles
less than 15 ym.
To meet this objective for HTP processes, EPA developed the
program illustrated in Figure 1. Particulate control at high temperature
and pressure was thought to be possible with cyclones, ceramic filters,
granular bed filters, non-aqueous scrubbers, and specially designed
electrostatic precipitators. However, models predicted that cyclones
would be less than 50 percent efficient below 1 \m and data indicated
(2)
poor efficiency even at 2.5 ym. ' Since collection of fine particles
was a pending subobjective to meet EPA standards, and cyclones demonstrated
low potential for fine particle collection, no development of cyclones
was planned. Development of the other approaches was planned as indicated
in Figure 1. The results of the progress along each path of Figure 1
are the subject of this report. Results of a field test of high temperature
and pressure cyclones are also included for comparison.
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BED FILTER
DRY .
SCRUBBER
oioicmo OIULM ^ oiinumiiuiY itoii
APT IN-HOUSE (1)
\ /
rvvnu _ ntwri nourUT
FEASIBILITY
TESTS
APT
GBF TESTS OF GBF
APT (2)
AUGMENTATION
APT (6)
" MUUtL
DEVELOPMENT
IN-HOUSE
r/
1
- — SYSTEMS •
TESTS
APT
YES
> »• DEMONSTRATION OF GBF
NO
MECHANISMS STUDY
APT
CERAMIC FABRICS
VERIFY MEDIA
AVAILABILITY
AEROTHERM
MODEL DEVELOPMENT
IN-HOUSE (3)
•+• SIMULATION
TESTS
IN-HOUSE
HIGH TEMPERATURE
ESP
VERIFY STABLE
CORONA R/C
MEDIA DEVELOPMENT
AEROTHERM (4)
•*• STATIC PERFORMANCE
TESTS
DRI (5)
EXXON TESTS
NO
DEMONSTRATION OF
ALTERNATE DEVICE
CALENDAR YEAR
MECHANISMS STUDY
APT
1977
1978
1979
1980
Figure 1. High temperature/pressure control
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Granular Bed Filters (GBFs) and Dry Scrubbers
Granular bed filters and dry scrubbers may be defined as any
collection system comprised of stationary or moving discrete, relatively
closely packed granules as the collection medium. With respect to
motion of the granules, granular bed filters may be classified as moving
or fixed bed filters. Dry scrubbers may be very similar to moving bed
filters except that the gas stream may be accelerated before contacting
the granules in order to maximize collection from impaction.
To evaluate granular bed filters and dry scrubbers, two contracts
with Air Pollution Technology were initiated in 1976 (68-02-2164 in
August and 68-02-2183 in September). The purpose of these contracts was
to assess the application of the APT dry scrubber and granular bed
filters, as made by Rexnord (Figure 2), Ducon (Figures 3 and 4), and
Combustion Power Co. (Figures 5 and 6), to the problem of particulate
control at high temperature and pressure. The results of thrc;e contracts
may be illustrated by comparing the APT, Combustion Power Corr. any (CPC),
and Ducon control devices. These three devices give a range of design
features available for collection of particulate on hard granules (see
Table 1). At one end of the spectrum are fixed granular bed filters
which rely on collection throughout the bed material until a layer or
cake is formed. The cake provides greater filtration efficiencies
especially for submicron particles. Optimizing the performance of the
fixed granular bed filter requires a cleaning system which preserves
some of the cake while preventing unacceptably high pressure drops.
Moreover, it is essential that the cleaning systems not allow particulate
to work its way through the bed either by insufficient cleaning or by
motion of the granules.
At the other end of the spectrum is the dry scrubber which relies
only on impaction for collection; a cake is never formed. In this case,
the gas velocity is high to optimize impaction. Collection of submicron
particles may be augmented by charging particles and granules with
different signs. In 1978, EPA began work with APT, Inc. (Contract 68-
02-3102) to verify the benefits of using electrostatics in dry scrubbers.
Cold flow experiments confirm that penetration of submicron particles
can be reduced by a factor of 4. Hot flow experiments will be completed
in 1980.
3
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OPERATING PHASE
BACKFLUSH PHASE
12
1. INLET CHAMBER
2. PRIMARY COLLECTOR (CYCLONE)
3. DOUBLE TIPPING GATE (DUST DISCHARGE)
4. VORTEX TUBE
5. FILTER CHAMBER
6. GRAVEL BED
7. SCREEN SUPPORT FOR BED
8. CLEAN GAS COLLECTION CHAMBER
9. EXHAUST PORT
10. BACKWASH CONTROL VALVE
11. BACKWASH AIR INLET
12. VALVE CYLINDER
13. STIRRING RAKE
14. STIRRING RAKE MOTOR/REDUCERS
Figure 2. Rexnord filter.
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FILTER
ELEMENT
INLET
CLEAN
GAS
OUTLET
COLLECTED
DUST
OUTLET
OUTER
SCREEN-
GRANULAR
BED
INNER SCREEN
Figure 3. Ducon filter.
Figure 4. Detail of Ducon filter using screens.
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DISENGAGEMENT
VhSSKI.
ELU1DIZED BED
FLU1DIZING AIR
• • MEDIA RETURN PIPE
FRONT PANEL
KILTER PANEL
OUTLET PANEL
TRANSPORT PIPE.
MEDIA OUTLET PIPE
TRANSPORT AIR
Figure 5. Combustion Power filter.
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GAS
FLOW
CLEAN
MEDIA
CONVEYOR
TO DUST STORAGE
Figure 6. Detail of collecting bed in CPC filter.
-------
Table 1. SUMMARY OF PERFORMANCE INFORMATION
ex
Superficial gas velocity, cm/s
Pressure drop, kPa
Bed depth, cm
Granule diameter, cm
Efficiency at 1 ym, %
Efficiency at 6 ym, %
Moving Granular
Bed Filter
(CPC)
20-80
1.2-5.7
20-40
0.08-0.2
78
93
Dry Scrubber
(APT)
3,000-6,000
2-7
NA
0.01
96
99
Fixed Granular
Bed Filter
(Ducon)
45
8 (from prediction)
3.8
0.04
82
96
-------
In the middle of the spectrum is the moving granular bed filter in
which the granules move slowly enough to form a bed which acts like a
filter. This device works partially by impaction and partially by
filtration but cannot be optimized for either since the gas velocities
are low and the bed is removed before a cake is formed. However, some
designs using intermittently moving granular beds do establish and
preserve the cake for better filtration.
The information in Table 1 is a quick comparison of the points in
the spectrum discussed above. Pressure drops for all three devices tend
to be the same. The APT dry scrubber has a very high gas velocity and
no bed. The CPC moving granular bed filter has a low gas velocity and a
thick bed. The Ducon filter has a low gas velocity and a thin bed. The
thick bed is used with the CPC moving bed filter to ensure good filtration
in the absence of cake filtration or high gas velocity for impaction
collection. In the case of these data the APT dry scrubber gave the
best performance. However, development of all these devices continues
and it would be premature to conclude that efficiencies will not be
improved. Both the APT and CPC devices can be augmented with electrostatic
effects such as imposing a field or charging the particles, charging the
granules, or both. Further development of the Ducon device will necessitate
(3)
improved cleaning to avoid problems noted in tests at the Exxon Miniplant. '
Tests at Exxon were terminated after a series of difficulties including
plugging and rapid loss of acceptable filtration efficiency. Because of
these results, further development of GBFs was ended early and points 1
and 2 on Figure 1 were never reached.
Ceramic Filters
Two types of ceramic filters were investigated: 1) flat rigid
filters, and 2) cylindrical bag filters. The first was made the subject
of Westinghouse Contract 68-02-1887 and the second, Aerotherm Contract
68-02-2169. A number of rigid ceramic filters were tested including
cubes comprised of thin filtering barriers separated by alternating
layers of corrugations. The advantage of the filtering cube is that it
has large surface area to volume ratios and has added strength to withstand
mechanical and thermal stress. Using a limestone test dust dust
-------
with a mass median diameter of 1.4 pm, the collection efficiency averaged
tfl\
96.4 percent in experiments at temperatures from 360 to 815°C. ' The
disadvantage of the filtering cube is that the void spaces are small and
could rapidly fill and plug with collected material. This would be
especially true with tarry particles from coal gasification or sticky
particles as encountered at the Exxon fluid bed combustor Miniplant.
Ceramic bag filters were investigated with three basic media types:
1) woven ceramics, 2) ceramic papers, and 3) ceramic felts. Tests with
0.3 pm particles showed that woven ceramics had low collection efficiencies,
always below 50 percent, and ceramic papers and felts had high collection
efficiencies, up to 99.5 percent. ' Another advantage of ceramic felts
was a loose flexible structure which would provide the durability
needed to withstand a miniumum lifetime of cleaning, typically requiring
several million cleaning cycles. For these reasons, it was decided to
continue the program with development of the ceramic felt media (point 4
in Fignre 1) and to arrange tests at the Exxon fluid bed combustor
Miniplant. Under contract 68-02-2611, Aerotherm performed extended
tests of Saffil* alumina, a type of ceramic felt, and demonstrated that
this media (as developed by Aerotherm) could be cleaned up to 50,000
times at 815°C and 9 atm without damage to the ceramic bag filter.
Tests at the Exxon Miniplant (see Figures 7 and 8) were run under
varying gas velocities through the bag and during combustion of two
different coal types in the fluid bed combustor. It was found that coal
type had little effect on filter performance. When superficial gas
velocity was increased from 4 to 10 cm/s there was a slight decrease in
efficiency from 99.4 to 98.6 percent. No problems with bag cleaning
were encountered and residual pressure drops were always below 5 kPa (20
in. H20). As shown by a vacuumed strip, filtration was on the outside
of the bag with no penetration of fine particles (see Figure 9). In
comparison to filters described in Table 1, this pressure drop is in the
same range, superficial gas velocities are lower, and efficiencies are
higher. The central remaining question for ceramic felt bag filters is
the upper limit on bag lifetime. Although these bags are relatively
inexpensive, trouble-free operation between scheduled outages would be
*ICI United States, Inc., Concord Pike and New Murphy Road, Wilmington, DE 19803
10
-------
CONTROL
PANEL
SLIPSTREAM TAP FOR GAS FEED TO FILTER
PIPING (PART OF EXXON MINIPLANT)
''
Figure 7. Cerauic bag test module at Exxon.
11
-------
TOP
SUPPORT
BAG
RETAINING CLAMPS
Figure 8. Detail of Saffil alumina ceranic ban.
12
-------
OUTSIDE SUPPORT,
STAINLESS STEEL SCREEN
VACUUMED
STRIP
™^ - i-rl
cfli -^.;-. \. :, -f
w? ;. — \ v if -:-k
II;;.:*
/>• l •. • • _ > ^,,
" . *- - • *tij
• •-.-•• h^m
EXXON
FBC DUST
Figure 9. Close-up of bag showing vacuumed strip,
13
-------
necessary. Consequently, demonstration of long term bag lifetime is
still required.
Electrostatic Precipitators
Under EPA contract 68-02-2104, Research Cottrell was asked to
verify the operability of electrostatic precipitators (ESPs) at high
temperature and pressure. The objectives of this work were to define
the temperature and pressure regions in which stable ESP operation is
possible and to determine the suitability of ESPs for particulate cleanup
on advanced energy conversion processes. ESPs work by producing ions
which charge the particles and cause the particles to migrate to the
collection plate under the influence of an electric field. The ions are
produced by corona discharge which will not be stable if sparkover
conditions are reached. Research Cottrell did verify that stable corona
was possible over the entire range of temperature and pressure combinations
of advanced energy conversion processes. Research Cottrell also found
that performance improved with increased temperature and pressure. This
implies that satisfactory collection efficiencies could be attained. As
an independent assessment, work was begun at Denver Research Institute
(grant 805939) to test an operating ESP at high temperature and pressure
(refer to point 5 on Figure 1). Results from this project will be
available in 1980.
Cyclones
Although no development of cyclones was undertaken, cyclones are of
interest because of their simplicity. A field test of the testing
cyclone at the Exxon Mini pi ant shows that in this case significant
collection below 1 ym is possible. With a pressure drop of 3.7 kPa
(15 in. H20), the collection efficiency at 1 ym was 80 percent; at
0.8 yrn, 70 percent; and at 0.7 ym, 50 percent. Although these results
are not unreasonable considering the pressure drop, ' they do not fit
available cyclone models which underpredict these efficiencies. ' In
light of the extremely sticky nature of the particles at the Exxon
Miniplant, it is possible that the apparent collection of submicron
particles is due to agglomeration into larger size regions. Further
14
-------
consideration of cyclones will have to be on an application by application
basis.
Summary
A spectrum of granular collecting devices has been discussed in
terms of three examples under development. Advantages of these differing
approaches are:
APT Dry Scrubber
High collection efficiency possible from impaction and electrostatic
attraction. Collecting granules are removed from the system for
easy cleaning.
Ducon Fixed Bed Filter
High collection efficiency possible from cake filtration. Low
attrition rates of bed material. Minimum energy requirement
because of low heat loss and no bed recirculation power.
CPC Moving Granular Bed Filter
Collecting granules are removed from the system for easy cleaning.
Electrostatic augmentation may provide high collection efficiencies.
In choosing between these alternatives, important considerations
include cost, the adhesiveness of the particulate, and the importance of
energy conservation. For example, if the particulate is sticky, a
system which removes granules for easy cleaning will be necessary. On
the other hand, if a fixed bed filter can be cleaned and removal of
granules implies a high energy loss, cost considerations may favor the
fixed bed filter.
A number of investigators have shown that high collection efficiencies
are possible with ceramic filtration at high temperature (greater than
800°C) and/or high pressure (greater than 900 kPa). The recent work has
tested both ceramic bags and rigid ceramic filters. Advantages of these
different approaches are:
15
-------
Ceramic Bag
High collection efficiency. Easy to clean. Resists failure
because of thermal shock.
Rigid Ceramic Filter
High collection efficiency. Compact. Resists failure because of
high pressure drop.
The endurance of both media is unknown. If the rigid ceramic filter can
be used without clogging or thermal shock, it could be maintained in
service for many years. However, ceramic bags are expected to have a
limited life because of the less durable nature of the bag structure.
Tests to date indicate that ceramic bags will easily survive up to
50,000 cleaning pulses or the equivalent of 1 year's light service.
Other devices considered are electrostatic precipitators and cyclones.
Advantuges of these are:
Electrostatic Precipitator
Very small pressure drop. High collection efficiency possible.
Cyclone
Simple. Available.
However, high temperature and pressure electrostatic precipitators need
further development before application. Cyclones may be efficient in
some cases, but generally low efficiency should be expected for fine
particles.
A concluding comparison of all devices is given in Table 2. Selection
of a device will depend primarily on the efficiency required and how
soon the device is needed. Approaches such as the APT scrubber and the
ceramic felt bag are the next to become available and offer higher
efficiencies than commercial filters and cyclones. However, in comparison
to filters, ceramic bags have low superficial velocities which may lead
to large capital intensive control units. Furthermore the APT dry
scrubber still needs testing at the pilot scale.
16
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Table 2. COMPARISON OF HIGH TEMPERATURE/PRESSURE
CONTROL DEVICES
Device
APT Dry Scrubber
CPC Filter
Ducon Filter
Ceramic Bag
Electrostatic Precipitator
Exxon Cyclone
Superficial
Velocity
c/s
3000-6000
20-80
45
4-10
100-200
NA
Pressure
Drop
kPa
2-7
1-6
8
5
0.2
4
Efficiency
at 1 um
%
96
78
82
99
NA
80
General
Status
bench
commercial
commercial
pilot
bench
commercial
17
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References
1. Vandegrift, A. E. et al., "Particulate Pollutant Systems
Study," EPA No. APTD 0743, NTIS No. PB 203-128, May 1971.
2. Ciliberti, D. F. and B. W. Lancaster, "Performance of Rotary
Flow Cyclones," AIChE J 22:2, p. 394, March 1976.
3. Hoke, R. C. et al. "Miniplant Studies of Pressured Fluidized-
Bed Coal Combustion: Third Annual Report". EPA-600/7-78-069, NTIS No.
PB 284-534, April 1978.
4. Drehmel, D. C. and D. F. Ciliberti, Paper #77-32.4, APCA
Annual Meeting, Toronto, Canada, June 1977.
5. Drehmel, D. C. and M. S. Shackleton, Paper #17, Third Symposium
on Fabric Filters for Particulate Control, Tucson, Arizona, December 1977.
6. Drehmel, D. C., Fine Particle Control Technology, JAPCA 27:138, 1977
7. Parker, R. D., Private communication to D. C. Drehmel, 1979.11
18
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BIBLIOGRAPHY
1. Calvert, S. et al., "Effects of Temperature and Pressure on
Particle Collection Mechanisms: Theoretical Review," EPA-600/7-77-002,
U.S. E.P.A., Research Triangle Park, N. C., 96 pp., NTIS PB 264-203/AS,
January 1977.
2. Kennedy, R.A. et al., "EPA and ERDA High-Temperature/High-
Pressure Particulate Control Programs," EPA-600/7-77-013, U.S. E.P.A.,
Research Triangle Park, N. C., 60 pp., NTIS PB 266-231/AS, February 1977.
3. Poe, G. G. et al., "Evaluation of Molten Scrubbing for Fine
Particle Control," EPA-600/2-77-067, U.S. E.P.A., Research Triangle Park,
N.C., 36 pp., NTIS PB 266-092/AS, March 1977.
4. Poe, G. G. et al., "Evaluation of Ceramic Filters for High-
Temperature/High-Pressure Fine Particulate Control," EPA-600/2-77-056,
U.S. E.P.A., Research Triangle Park, N. C., 55 pp., NTIS PB 266-093/AS,
February 1977.
5. Parker, R. and S. Calvert, "High-Temperature and High-Pressure
Particulate Control Requirements," EPA-600/7-77-071, U.S. E.P.A., Research
Triangle Park, N. C., 123 pp., NTIS PB 271-699/AS, July 1977.
6. Ciliberti, D.F., "High Temperature Particulate Control with
Ceramic Filters," EPA-600/2-77-207, U.S. E.P.A., Research Triangle Park,
N. C., 172 pp., NTIS PB 274-485/AS, October 1977.
7. Bush, I. R. et al., "Development of a High-Temperature/High-
Pressure Electrostatic Precipitator," EPA-600/7-77-132, U.S. E.P.A.,
Research Triangle Park, N. C., 85 pp., NTIS PB 276-626/AS, November 1977.
8. "EPA/DOE Symposium on High-Temperature, High-Pressure Particulate
Control," EPA-600/9-78-004, 633 pp., NTIS No. CONF-770970, March 1978.
9. Shackleton, M. A., "High-Temperature, High-Pressure Particulate
Control with Ceramic Bag Filters," EPA-600/7-78-194, U.S. E.P.A., Research
Triangle Park, N. C., 93 pp., NTIS PB 290-104/AS, October 1978.
10. Parker, R. and S. Calvert, "Alternatives for High-Temperature/
High-Pressure Particulate Control," EPA-600/7-79-019, U.S. E.P.A., Research
Triangle Park, N. C., 135 pp., NTIS PB 292-687/AS, January 1979.
11. Yung, S. et al., "Evaluation of Granular Bed Filters for High-
Temperature/High-Pressure Particulate Control," EPA-600/7-79-020, U.S. E.P.A.,
Research Triangle Park, N. C., 240 pp. NTIS PB 299-195/AS, January 1979.
12. Shackleton, M. A., "Extended Tests of Saffil Alumina Filter
Media," EPA-600/7-79-112, U.S. E.P.A., Research Triangle Park, N. C., 30
pp., NTIS PB 297-567/AS, May 1979.
19
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/8-79-031b
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Particulate Control Highlights: Research at High
Temperature/Pressure
5. REPORT DATE
December 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Dennis C. Drehmel and James H. Abbott
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
EHE624A
See Block 12
11. CONTRACT/GRANT NO.
NA
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Inhouse; 4/79-10/79
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES The authors' mail drop is 61; their phone number is 919/541-2925.
16. ABSTRACT
repOr|- gives highlights of EPA high- temperature and high- pressure
programs aimed at demonstrating control technology to meet environmental standards
for the ambient concentration of particles and the emission rate of particles from
new sources. Among the control devices considered in the EPA programs were
cyclones, granular bed filters , dry scrubbers , molten scrubbers, electrostatic pre-
cipitators (ESPs), ceramic bag filters , and other (non-bag) ceramic filters. Advan-
tages and disadvantages of the devices involve parameters such as simplicity of oper-
ation, materials problems, inability to collect submicron particles, difficulty in
regenerating the collection media, and those related to cost, including size and pres-
sure drop. Since these advantages and disadvantages can be weighed differently,
according to the needs of a specific application, it is not possible to give universal
conclusions. However, if the most important consideration is control of submicron
particles, ceramic filters are foremost. Although particulate control equipment can
be demonstrated to have high collection efficiency in some applications, extreme
conditions of temperature, pressure, or both pose special problems. The need for
control at extreme condition arises in metallurgical operations and advanced energy
processes.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution Electrostatic Pre-
Dust cipitators
Aerosols Dust Filters
High Temperature Tests Scrubbers
High Pressure Tests Ceramics
Cyclone Separators
Pollution Control
Stationary Sources
Particulate
13B
11G
07D 13K
14B
11B
07A,13I
13. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS /This Report)
Unclassified
21. NO. OF PAGES
24
20. SECURITY CLASS (Thispage}
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
20
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