United States Industrial Environmental Research EPA-600/7-80-O35
Environmental Protection Laboratory February 1980
Agency Research Triangle Park NC 27711
Particulate Control at
High Temperature and
Pressure Using
Augmented Granular
Bed Filters
Interagency
Energy/Environment
R&D Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
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The nine series are:
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5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
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RESEARCH AND DEVELOPMENT series. Reports in this series result from the
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Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
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essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
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This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-80-035
February 1980
Particulate Control at High
Temperature and Pressure Using
Augmented Granular Bed Filters
by
Shui-Chow Yung, R.G. Patterson,
and Seymour Calvert
A.P.T., Inc.
4901 Morena Boulevard, Suite 402
San Diego, California 92117
Contract No. 68-02-2183
Program Element No. EHE624A
EPA Project Officer: Dennis C. Drehmel
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
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ABSTRACT
The effect of electrostatic augmentation on granular bed
filter particle collection efficiencies was measured experimen-
tally in fixed and moving bed filters. The collection efficiency
of a granular bed filter was greatly improved by imposing an
electric field on the bed and/or by charging the particles. The
electrostatically enhanced granular bed filter is capable of
cleaning the gas sufficiently to meet the proposed new source
performance standard of 13 mg/MJ (0.03 lb/106 BTU).
111
-------
CONTENTS
Abstract. , iii
Figures . . „ « v
Tables. . viii
Abbreviations and Symbols . . . „ ^x
Acknowledgement x
Sections
1. Summary and Conclusions 1
Summary . • 1
Conclusions <> . . . 3
2. Introduction 4
3. Fixed Bed Granular Bed Filter Experiments 5
Fixed Bed Granular Bed Filter 5
Collection Efficiency of a Neutral Clean Bed g
Collection Efficiency of an Electrostatically
Augmented Bed 13
Cake Filtration 22
4. Moving Bed Granular Bed Filter Experiments 28
Experimental Setup. . 28
Data 30
Data Analysis 30
5. Evaluation of Electrical Augmentation of Granular Bed
Filters 4!
6. Future Research Recommendations 43
References 45
Appendices
A. Fixed Bed GBF Experimental Data . . . 45
B. Cascade Impactor Particle Data . 57
C. Experimental Grade Penetration Curves of the Moving
Bed Granular Bed Filter „ 79
iv
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FIGURES
Number Page
1 Schematic diagram of the experimental apparatus with
PSL dispenser 6
2 Schematic diagram of the experimental apparatus with
fly ash generator 0 7
3 Experimental pressure drop of clean GBFs 9
4 Impaction efficiency for round jet . 0 11
5 Effect of particle charging on penetration „ 12
6 Redispersed fly ash particle size distribution 14
7 Experimental grade penetration of a fixed GBF 15
8 Experimental voltage-current relation 17
9 Effect of field strength on particle penetration .... 18
10 Experimental grade penetration of a charged GBF. , . . . 20
11 Experimental particle penetration of a clean AC
polarized GBF0 21
12 Effects of particle loading in bed on penetration of a
fixed GBF 23
13 Experimental pressure drop of a dirty GBF 25
14 Experimental penetration of a dirty GBF . . 26
15 Experimental penetration of a dirty GBF 27
16 Moving Bed GBF (34.3 m /min) 29
17 Measured particle penetration for various operating
conditions of a GBF 32
18 Effect of granule recirculation rate on penetration. . „ 34
19 Effect of granule recirculation rate on penetration. „ . 35
v
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FIGURES (continued)
Number Page
20 Effect of granule cleanliness on penetration 35
21 Measured penetrations of a fixed bed and a moving GBF . 37
22 Effect of gas velocity on penetration 39
23 Effect of gas velocity on penetration 40
Appendix A
A-l Experimental particle penetration of a clean, grounded
GBF 47
A-2 Experimental particle penetration of a clean, grounded
GBF 48
A-3 Experimental particle penetration of a clean,
neutralized GBF 49
A-4 Experimental charged particle penetration through
neutral, clean GBF. . „ 50
A-5 Experimental charged particle penetration through
neutral, clean GBF0 „ 51
A-6 Experimental charged particle penetration through
a neutral, clean GBF 52
A-7 Experimental particle penetration of a clean, DC
polarized GBF „ 53
A-8 Experimental particle penetration of a clean, DC
polarized GBF <,...„ 54
A-9 Experimental particle penetration of a DC polarized,
clean GBF 55
A-10 Experimental particle penetration of a clean, DC
polarized GBF <>.... 56
A-ll Experimental charged particle penetration through
a clean, DC polarized GBF 57
A-12 Experimental charged particle penetration through
a clean, DC polarized GBF „ 58
A-13 Experimental charged particle penetration through
a clean, DC polarized GBF 59
VI
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FIGURES (continued)
Number Page
A-14 Experimental charged particle penetration through
a clean, DC polarized GBF 60
A-15 Experimental particle penetration of a dirty GBF .... 61
A-16 Experimental penetration of a dirty, charged GBF .... 62
A-17 Experimental penetration of a dirty, grounded fixed GBF. 63
A-18 Experimental penetration of a dirty GBF „ . . . 64
A-19 Experimental penetration of an AC charged, dirty,
fixed GBF «, . . . . 65
A-20 Experimental penetration of an AC charged, dirty,
fixed GBF 66
Appendix C
C-l through C-14 Experimental grade penetration curves
of the moving GBF 80
VII
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TABLES
Number Page
1 Test Conditions and Particle Data. . „ . . . . „ . .
Appendix B
B-l through B-21 - Cascade Impactor Data for Runs #1
through #21
Vlll
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LIST OF ABBREVIATIONS AND SYMBOLS
C' = Cunningham slip correction factor, dimensionless
d = collector diameter, ym or cm
d = particle diameter, ym or cm
d = number median diameter of particle, ym or cm
K = inertial impaction parameter, dimensionless
M = ratio of granule mass recirculated to gas mass flow kg/kg
Ptj = penetration for particle diameter "d", fraction
u.: = jet velocity, cm/s
UG = superficial gas velocity, cm/s
Z = bed thickness, cm
Greek
n - single impaction stage collection efficiency, fraction
e = bed porosity, fraction
p = particle density, g/cm3
a/, = geometric standard deviation, dimensionless
AP = pressure drop, cm W.C.
y = gas viscosity, g-cm/s
IX
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ACKNOWLEDGEMENT
A.P.T., Inc. wishes to express its appreciation for excellent
technical coordination and for very helpful assistance in support
of our technical effort to Dr. Dennis C. Drehmel of the U.S.
Environmental Protection Agency.
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SECTION 1
SUMMARY AND CONCLUSIONS
SUMMARY
The feasibility of advanced energy processes depends on the
availability of a very efficient high temperature and
pressure (HTP) particulate cleanup device. The particulate con-
trol equipment should be capable of operating at a gas tempera-
ture up to 950°C and a gas pressure up to 20 atm.
Granular bed filters (GBFs) have been proposed as control
equipment for removing fine particles from high temperature and
high pressure gas streams. It has been shown by Yung, et al.
(1979) that the use of GBFs for HTP applications is limited by
the particulate removal efficiency and operating difficulties.
By properly selecting granules and structural materials, the gran-
ular bed filter could be capable of operating at the temperatures
and pressures encountered in advanced energy processes. However,
unless aided by other collection mechanisms, the present GBF
designs are not likely to meet the proposed NSPS for boilers or
the turbine requirements proposed by Sverdrup and Archer (1977) .
There are several methods that may be used to increase the
collection efficiency. One method is to use a deep bed of fine
granules and a high face velocity. This is not a desirable
approach as the pressure drop would be very high. Other effective
methods are electrostatic augmentation and cake filtration.
If the bed is placed in a polarizing electric field, the
granules will be polarized to produce an inhomogeneous electric
field near the granule surface. A charged particle entering the
bed will interact with the external field and the local field. The
dipole interaction force between the granule and the particle
will result in a higher collection efficiency. If the particles
are uncharged, the external field will also polarize the particles
The dipole interaction force still exists.
-------
A filter cake may be used to increase the collection effic-
iency of the bed. The collection mechanism depends on the type
of cake. A surface cake predominantly collects by sieving. if
it is an internal cake, then impaction may be more important.
The dust deposit can increase the impaction parameter by reducing
the bed porosity and increasing the gas velocity in the bed. A
larger impaction parameter results in a higher collection effic-
iency.
The effectiveness of cake filtration and electrostatic
augmentation were measured experimentally in the laboratory. Ex-
periments were performed on two small scale granular bed filters.
They were a fixed bed with a gas flow capacity of 0.44m3/min
(15.5 CFM) and a moving bed with gas capacity of 2.8m3/min (100
CFM).
All experiments were performed under ambient conditions.
Monodispersed polystyrene latex and redispersed fly ash particles
were used for testing. Test conditions included:
1. Grounded bed/uncharged particle
2. Polarized bed/uncharged particle
3. Grounded bed/charged particle
4. Polarized bed/charged particle
5. Clean and dirty bed
6. AC and DC polarization
The experimental findings are:
1. By either polarizing the bed or charging the particles,
the collection efficiency of the filter increased significantly.
The collection efficiency increased with increasing applied vol-
tage across the bed.
2. By both polarizing the bed and charging the particles,
the bed becomes very efficient in collecting particles. For a
15 cm deep bed of 1.6 mm diameter alumina spheres and with a
polarizing field strength of 1.31 kV/cm, the collection efficiency
was above 98% for all particle sizes.
-------
3. Polarizing the bed and/or charging the particles has no
effect on pressure drop across a clean bed.
4. The presence of a filter cake will increase the collection
efficiency of the granular bed filter. The increase depends on
the cake structure and the amount of dust retained in the bed.
5. DC polarization is much more effective than low frequency
AC polarization.
6. Fixed bed GBFs exhibit a higher collection efficiency
and a higher pressure drop than moving beds. In the moving bed
system, lower recirculation rate also has a lower rate of attri-
tion of retaining grids and granules and a lower rate of dislodging
and reentraining the collected particles.
CONCLUSIONS
It has been demonstrated that the collection efficiency of a
granular bed filter can be greatly improved by imposing an elec-
tric field on the bed and by charging the particles. The electro-
statically enhanced granular bed filter is able to clean the gas
to meet the current and proposed new source performance standards.
However, in order for the granular bed filter to be commercially
acceptable and competitive, several operational problems and
uncertainties need to be resolved. Development needs include:
reliable bed cleaning method, a cost effective granule regenera-
tion and recirculation technique, HTP electrical insulation,
means for minimizing the erosion of bed retaining grids, and
particle reentrainment prevention.
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SECTION 2
INTRODUCTION
Granular bed filters have been proposed as fine particle
control devices for advanced energy processes operating at high
gas temperatures and gas pressures. Yung et al. (1979) evaluated
granular bed filter technology and concluded that granular bed
filters have the potential to meet New Source Performance Stan-
dards (NSPS) and gas turbine requirements. However, present
granular bed filter designs do not have high enough collection
efficiency for fine particles, especially when operating at high
temperatures.
A few quantitative studies have been reported in the litera-
ture which indicate that the collection efficiency of the bed
may be increased by: (1) electrostatic augmentation, and (2) cake
filtration.
In this study we performed bench scale experiments to evalu-
ate the increases in particle collection efficiency obtained by
augmenting the GBF with electrostatic force and by establishing
a filter cake. This report presents the experimental results.
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SECTION 3
FIXED BED GRANULAR BED FILTER EXPERIMENTS
FIXED BED GRANULAR BED FILTER
The small scale fixed bed granular bed filter was made of
10.2 cm (4 in.) I.D. glass pipe. The filter was a bed packed
with either -28 +35 mesh (420 ym to 595 ym diameter) sand, I mm
diameter glass beads, or 1.6 mm diameter alumina spheres. A
maximum gas flow rate of 0.44 m3/min (15.5 CFM) was used.
Two types of particles were studied. They were monodis-
perse polystyrene latex (PSL) and redispersed power plant fly
ash. The experimental setup for using PSL particles is shown in
Figure 1. Filtered room air was used for the study and all flow
rates were monitored with rotameters. Monodisperse polystyrene
latex aerosol was generated using a Collison atomizer. The
aerosol mist from the generator mixed with a stream of filtered
dilution air and either passed through a Krypton 85 charge neu-
tralizer or was charged by passing through a corona charging
section.
Following the neutralizing section or the charging section,
the aerosol was further diluted with filtered room air. It then
flowed into the granular bed test section, which could either be
polarized by imposing an electrostatic field across the bed in
the direction of gas flow or could be grounded. The particle
concentrations before and after the bed were measured with an
optical counter. Pressure drop was monitored with calibrated
gauges.
The experimental setup for using redispersed fly ash par-
ticles is shown in Figure 2. It is similar to the apparatus for
using PSL particles except the Collison atomizer, charger and
neutralizer were replaced with a fluidized bed particle generator,
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o-
PRESSURE TAPS
TO OPTICAL COUNTER
GRANULAR BED
AMMETER
POWER SUPPLY
Kr-85 CHARGE NEUTRALIZER
TO OPTICAL
COUNTER
! r~"3 r-i
PARTICLE CHARGER
FILTER
COMPRESSED
AIR
AIR
Schematic diagram of the experimental
apparatus with PSL dispenser.
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FILTER
PRESSURE I
DROP
NOZZLE
1
TO PARTICLE
SAMPLING TRAIN
GRANULAR
BED FILTER
ROTAMETER
FILTER
BLOWER
AMMETER
FILTER
POWER
SUPPLY
TO PARTICLE
SAMPLING TRAIN
VENT
FLUIDIZED BED
PARTICLE GENERATOR
COMPRESSED AIR
PO-210
AIR IONIZING NOZZLE
AIR
Figure 2. Schematic diagram of the experimental apparatus with
fly ash generator.
7
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COLLECTION EFFICIENCY OF A NEUTRAL CLEAN BED
Polystyrene Latex Particles
The particle penetration was measured for several bed
materials and bed thicknesses. Gas phase pressure drop is
plotted against superficial gas velocity in Figure 3. The
data for neutralized 1.1 ym diameter polystyrene latex par-
ticles are presented in Figures Al to A3 of Appendix "A".
As has been observed by other investigators, the particle
penetration of a clean neutral bed decreases with increasing
bed thickness, increasing superficial gas velocity, and
decreasing granule diameter.
We (Yung et al., 1979) performed an extensive study of
particle collection by clean granular bed filters and developed
a mathematical model for particle collection by inertial impac-
tion in a clean granular bed filter. The model is:
Ptd - (1 -
where: Ptj = penetration for particle diameter "d " , fraction
n = single impaction stage collection efficiency, frac
tion
Z = bed depth, cm
d = granule diameter, cm
The single stage collection efficiency was calculated from exper
imental data and can be approximated by the following empirical
equation:
n = 10 K exp(0.27 in2 K ) ,
0.003 - K -0.15
P
-------
50
40
30
20
u
•
*
* 10
0,
§
P
w
co
w
UJ
5
4
3.8 cm DEEP
-28 +35 MESH
SAND "-
5.1 cm DEEP
1 mm DIA. GLASS
BEADS
1.8 cm DEEP
-28 +35 MESH SAND
2.5 cm DEEP
1 mm DIA. GLASS
BEADS
10.2 cm DEE
1.6 mm DIA. ALUMINA
BEADS
10 20 30 40 50 100
SUPERFICIAL GAS VELOCITY, cm/s
Figure 3. Experimental pressure drop of clean GBFs.
-------
where: K = inertial impaction parameter, dimensionless
3
9 yG dc 2 E 9 yG dc
C1 = Cunningham slip correction factor, dimensionless
d = particle diameter, cm or ym
P
p = particle density, g/cm3
u. = Jet velocity, cm/s
u~ = superficial gas velocity, cm/s
b
e = bed porosity, fraction
d = granule diameter, cm
yp = gas viscosity, g-cm/s
Single stage collection efficiency based on equation (1)
was calculated from data obtained in this study. Efficiencies
computed this way are plotted against "K " in Figure 4 along
with that reported by Yung et al.(1979). As can be seen, the
two sets of data are in good agreement.
Experimentally determined penetrations of charged particles
through neutral beds are plotted in Figures A-4 through A-6. Par-
ticle charging will decrease the penetration, as illustrated in
Figure 5. For a 1.8 cm deep bed of -28 +35 mesh sand operated
at u- = 40 cm/s, the penetration decreased from 75% to 39% after
b
charging only the particles.
Fly Ash Particles
Two runs were performed with redispersed fly ash particles.
The aerosol was passed through the bed at a superficial gas
velocity of 50 cm/s. The bed was packed with 1.5 mm diameter
alumina spheres to a depth of 10.2 cm (4 in.).
Particle samples were taken isokinetically before and after
the bed with filters. The particle size distributions were
determined by analyzing the filtered samples with a Coulter Counte-r
10
-------
0.1
2
o
I—I
0.001
I I I I I
O DATA FOR -28 + 35 MESH SAND
D DATA FOR 1 mm GLASS BEADS
-YUNG ET AL.
(1979) DATA
AEROSOL: NEUTRALIZED
1.1 ym PSL
BED: GROUNDED
0.01
0.1
Kp, DIMENSIONLESS
Figure 4. Impaction efficiency for round jet,
11
-------
b
s
LU
UJ
CL.
BED THICKNESS: 1.8
NEUTRAL PARTICLE
CHARGED PARTICLE
gBED MATERIAL: -28 +35 MESH SAND
AEROSOL: 1.1 ym DIA. PSL
BED: GROUNDED
0.05
20 30 40
SUPERFICIAL GAS VELOCITY
Figure 5. Effect of particle charging on penetration.
12
-------
Grade penetration curves and the amount of particles collected
by the bed were calculated from the filter data and Coulter
Counter data.
The first run lasted 40 minutes. The inlet particle concen-
tration was 2.45 g/DNm3 (1.07 gr/SCF) and the outlet particle
concentration was 0.018 g/DNm3 (0.0075 gr/SCF). Thus, the over-
all penetration was 0.7%. The fly ash retention in the bed was
calculated to be 0.31 g/cm2 of bed cross section.
The second run lasted 105 minutes. The inlet and outlet
particle concentrations were 1.4 g/DNm3 (0.57 gr/SCF) and 0.11
g/DNm3, respectively. The overall penetration was 81 and the
particulate retention in the bed was 0.4 g/cm3.
The difference in overall penetration was mainly due to the
difference in inlet particle size distribution. Figure 6 shows
the inlet and outlet particle size distributions for these two
runs. For Run #1, the number median diameter, "d " is 1.6 ym
and the geometric standard deviation, "a ", is 1.6. For Run #2,
o
d N = 0.8 ym and a = 1.9.
The grade penetration curves for these two runs were close
to each other as shown in Figure 7. The dashed line is the pre-
diction based on equation (1). A particle density of 2.2 g/cm3
was used in the calculations. The agreement between measurement
and theory is good.
COLLECTION EFFICIENCY OF AN ELECTROSTATICALLY AUGMENTED BED
DC Augmented Bed
PSL Particles
The filtration efficiency can be enhanced by electrostatic
augmentation. If the filtration medium is immersed in an elec-
trostatic field, particles will be driven in a direction that
tends to increase the probability of impact between particles
and the filter medium.
Figures A-7 through A-10 in Appendix "A" show the experimen-
tal particle penetration of neutralized 1.1 ym diameter polysty-
rene latex particles through a clean DC augmented bed. Penetration
13
-------
10
w
u
h—I
c/5
>H
ex
0.5
0.3
20 30 4
0 50 60 70 80 90 98 99
PERCENT BY NUMBER UNDERSIZE, !
99.8 99.9
Figure 6. Redispersed fly ash particle size
distribution.
14
-------
1.0
0.5
0.1
c 0
o
._,
~
u
m
05
H
W
2
W
cx
0.005
0.001
PREDICTED
i
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED THICKNESS: 10.2 cm
AEROSOL: FLY ASH
SUPERFICIAL GAS VELOCITY: 50 cm/s
01 k->
0.5 1.0 3 5
PARTICLE DIAMETER, ym
Figure 7. Experimental grade penetration of a fixed GBF,
15
-------
of charged particles through a clean, DC polarized bed are
shown in Figures A-ll through A-14.
By polarizing the bed, the particle collection efficiency was
increased. The collection efficiency increased with increasing
applied voltage across the bed. For a 1.8 cm deep bed packed
with -28 +35 mesh sand, collection efficiency for 1 pm diameter
particles at UG = 40 cm/s increased from 25% to 90% [penetration
decreased from 75% to 10%) when the applied voltage across the
bed increased from 0 to 11.4 kV (from 0 to 6.3 kV/cm)
With the particles charged and the bed polarized, the GBF
collection efficiency can be very high. The highest voltage
across the bed in the charged particle/polarized bed experiment
was 1.6 kV for the 1.8 cm deep bed of -28 +35 mesh sand. The
collection efficiency for 1.1 ym diameter aerosol was 961 at u =
40 cm/s. The applied voltage across the bed could be higher but
the experimental measurements were limited by the sensitivity of
the optical counter. At higher applied voltage the particle
concentration at the GBF outlet was too low for the counter to
measure accurately.
Polarizing the bed and/or charging the particles did not
change the pressure drop across a clean bed.
Figure 8 shows the voltage and current relationship across
the bed. Since water is a semi-conductor, the current flow
varies with moisture content in the bed and with the humidity of
gas passing through the bed. Data shown in Figure 8, were taken
when the relative humidity of the ambient air was 601. AS can be
seen from Figure 8, the current flow is almost independent of the
superficial gas velocity at a constant voltage across the bed.
Figure 9 shows a cross plot of the data. Particle penetra-
tion for 1.1 ym diameter particle is plotted against field
strength for beds operated at a superficial gas velocity of 40
cm/s. The pressure drop across the beds was 6.4 cm W.C.
16
-------
24
20
"I—I—I—I—I—I—I—I—I—
BED: 1.8 cm DEEp, 28-35 MESH SAND
AEROSOL: NEUTRALIZED 1.1 urn DIA. PSL
—r
16
12
E-
z
t-U
ci
VOLTAGE
ACROSS BED
11.4 kV
7.9 kV
5.8 kV
4.4 kV
2.6 kV
1.7 kV
t i
XT
i
T 1 r—T 1 r
10
20 30 40 50 60 70 80
SUPERFICIAL GAS VELOCITY, cm/s
Figure 8. Experimental voltage-current relation.
90
100
-------
100
CO
50
40
30
20
10
0
Hi 1 ! ' .li
AEROSOL: 1.1 ym DIA. PSL
GAS VELOCITY: 40 cm/s
PRESSURE DROP: 6.4 cm W.C.
NEUTRALIZED PARTICLE
CHARGED BED
5.1 cm DEEP,
1 mm DIA.
GLASS BEAD
1.8 cm DEEP, -28 +35:
MESH SAND BED
CHARGED PARTICLE
CHARGED BED
0
3 4 5
FIELD STRENGTH, kV/cm
•
Figure 9. Effect of field strength on particle penetration.
-------
The pressure drops across 1.8 cm deep bed of -28 +35 mesh
(500 ym diameter) sand and 5.1 cm deep bed of 1 mm diameter
glass beads were identical. When both the bed and particles
were uncharged, the sand bed gave higher collection efficiency
as revealed by comparing Figure A-l with Figure A-2. However,
when the beds were charged, the collection efficiencies of the
sand bed and the glass bed were about the same, at the same field
strength (Figure 9). Thus, for an industrial GBF with polarized
beds, deeper beds of larger granules could be used in place of
shallow beds of fine granules. The use of larger granules can
reduce the possibility of plugging of the retaining grids by
dust since larger opening retaining grids could be used.
The use of larger granules and deeper bed does have a
drawback. It requires a higher applied voltage to obtain the
same field strength.
Fly Ash Particles
One run was done with fly ash particles. The grade pene-
tration curve for a DC polarized bed is shown in Figure 10 along
with that for a neutral bed. As with PSL particles, the collec-
tion efficiency was greatly improved by polarizing the bed with
an external field. The improvement is greater for submicron
particles than larger particles.
AC Polarized Bed
A few runs were performed to determine the feasibility of
using AC to polarize the bed. Figure 11 shows the data for the
penetration of neutralized 1.1 ym diameter particles through
an AC polarized bed, 10.2 cm deep of 1.6 mm diameter alumina
spheres. Data for neutral bed and for DC polarized bed are also
shown.
Polarizing the bed with AC did slightly improve the collec-
tion efficiency of the bed for 1.1 ym diameter particles. How-
ever, the improvement appeared to be less than DC polarization
with the same field strength. In addition, the power consumption
19
-------
1.0
0.5
:-:
0
•H
•M
m
2
O
0.1
0.05
H
W
2
W
CL,
0.01
0.005
0.001
NEUTRAL BL;D
APPLIED VOLTAGE
11 kV DC
BED MATERIAL: 1.6 mm |
DIA. ALUMINA
i BED H: 10.2 cm
AEROSOL: FLY ASH
SUPERFICIAL GAS
VELOCITY: 50 cm/s
1.0 3
PHYSICAL DIAMETER, ym
Figure 10. Experimental grade penetration of a charged
GBF.
20
-------
1.0
0.9
0.8
0.7
o
£0.6
o
cd
^
m
. 0.5
o
i— i
1
X
-
0.1
AC POLARIZED BED
16 kV
DC POLARIZED BED
16 kV
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED DEPTH: 10.2 cm
AEROSOL: NEUTRALIZED 1.1 ym DIA. PSL
20
30 40 50 60 70 80 90 100
SUPERFICIAL GAS VELOCITY, cm/s
Figure 11. Experimental particle penetration of a clean AC
polarized GBF.
21
-------
with AC polarization was about ten times higher than with DC
polarization (for DC polarization, J = 1 pA; for AC polarization
I = 10
CAKE FILTRATION
The collection efficiency of the granular bed will be higher
if there is a filter cake. The increase will depend on the cake
structure and the amount of dust retained in the bed. If it is
an internal cake, the pores will be smaller than the clean bed.
Smaller pores result in a higher jet velocity, a higher impaction
parameter, and a higher collection efficiency.
If the cake is a surface cake, the predominant particle
collection mechanism is sieving. The collection efficiency of
the bed will depend only on the pore size in the cake and will be
independent of the bed thickness and granule diameter.
Experiments were performed to determine the effect of filter
cake on efficiency. The bed was first loaded with dust by passing
redispersed fly ash through the bed at a superficial gas velocity
of 50 cm/s. The amount of dust retained in the bed was calculated
from the inlet and outlet particle concentrations (calculated
from simultaneous inlet and outlet filter sample) and the time
the dust was passed through the bed.
After the bed was loaded with fly ash, a monodisperse poly-
styrene latex aerosol of 1.1 ym diameter was generated and passed
through the dirty bed. Inlet and outlet particle concentrations
were measured with an optical particle counter.
Experiments were done for the following conditions:
1. Neutral particle and neutral dirty bed,
2. Neutral particle and DC polarized dirty bed,
3. Charged particle and neutral dirty bed,
4. Charged particle and DC polarized dirty bed,
5. Neutral particle and AC polarized dirty bed, and
6. Charged particle and AC polarized dirty bed.
Experimental data are plotted in Figures A-15 through A-20 in
Appendix "A".
22
-------
§
•H
»J
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3 :
0.2 .
0.1
DIRTY BED: PARTICLE
RETENTION IN BED
0.31 g/cm2
=0.4 g/cm2
BED MATERIAL: 1.6 nun DIA. ALUMINA
BED DEPTH: 10.2 cm
AEROSOL: NEUTRALIZED 1.1 ym PSL
30
Figure 12.
50 60 70 80 90 100
SUPERFICIAL GAS VELOCITY, cm/s
Effects of particle loading in bed on penetration of a fixed GBF,
23
-------
Figure 12 shows the effect of filter cake on efficiency
As expected, the presence of filter cake increased the collection
efficiency of the bed. The collection efficiency of the bed
with a particle retention of 0.31 g/cm? is higher than the bed
with a particle retention of 0.40 g/cm''. This suggests that
collection efficiency not only depends on the amount of particles
retained in the bed but also on the cake structure. In both
dirty beds, the filter cakes existed as internal cake. No sur-
face cake was visible. In the bed with a particulate deposit of
0.31 g/cm2, the cake concentrated near the surface. In the bed
with a particle deposit of 0.4 g/cm3, the particles had penetrated
all the way through the bed.
Figure 13 shows pressure drop data. Dirty beds have a
higher pressure drop than the clean bed. The bed with a particle
deposit of 0.31 g/cm2 had a higher efficiency than the bed with
0.4 g/cm2; however, its pressure drop was also higher.
Data for electrostatically augmented dirty beds are summar-
ized in Figures 14 and 15. As in the case with the clean beds
penetration decreases with increasing applied voltage across the
bed, and DC polarization is more effective than AC polarization
-------
u
*
B
U
§
Q
pq
to
tf)
w
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED DEPTH: 10.2 cm
DIRTY BED: PARTICLE
RETENTION IN BED
-0.31 g/cm2
0.4 g/cm2
CIEAN BED
20 30 40 50 60 70 80 90 100
SUPERFICIAL GAS VELOCITY, cm/s
Figure 13. Experimental pressure drop of a dirty GBF.
25
-------
NEUTRAL PARTICLE/NEUTRAL BED
NEUTRAL PARTICLE/AC POLARIZED BED
(11 kV AC)
CHARGED PARTICLE/NEUTRAL BED
NEUTRAL PARTICLE/DC POLARIZED BED
(11 kV DC)
CHARGED PARTICLE/AC POLARIZED BED
(1 kV AC)
PARTICULATE: 1.1 vim
BED MATERIAL: 1.6 : DIA ALUMINA
BED DEPTH: 10.2 cm
PARTICULATE DEPOSIT IN BED: 0.4g/cm2
•••• • j .''
. -...- , ,
20 30 40 50 60
SUPERFICIAL GAS VELOCITY, cm/s
70 80 90 100
Figure 14. Experimental penetration of a dirty GBF.
-------
1.0
c
o
•H
U
o
03
2
o
0.5
0.4
0.3
0.2
w
0.05
0.05
0.04
0.03
0.02
NEUTRAL PARTICLE/NEUTRAL BED
CHARGED PARTICLE/
NEUTRAL BED\
NEUTRAL PARTICLE/
DC POLARI 5D BED/£
V = kV
V = 16 kV j
CHARGED PARTICLE/DC!?
POLARIZED BED
1 (1 fcV DC)
jj.jT^
zr-LHT! T1 r- -n4+t
o.oi
PARTICLE DIAMETER: 1.1 Um
BED MATERIAL: 1 . 6 mm DIA. ALUMINAS
BED DEPTH: 10.2 cm
PARTICLE DEPOSIT IN BED: 0.31g/on!
n
10 20 30 40 50 100
SUPERFICIAL GAS VELOCITY, cm/s
Figure 15. Experimental penetration of a dirty GBF.
27
-------
SECTION 4
MOVING BED GRANULAR BED FILTER EXPERIMENTS
EXPERIMENTAL SETUP
Figure 16 shows the experimental setup for the moving bed
granular bed filter. It mainly consisted of a blower and a
granular bed filter test section. The system was operated under
forced draft condition.
The GBF test section consisted of a particle charger and
a single downflowing vertical panel of granules which were held
in place by means of two retaining grids. The panel was 20.3 cm
wide, 91 cm long, and 15 cm thick (8" x 36" x 6"). The front
retaining grid was a steel plate perforated with horizontal slots
The slotted portion of the plate was 45 cm long (18 in.). Each
slot was 3.2 mm wide and 22 mm long (1/8 in x 7/8 in.). Spacing
between slots was 3.2 mm (1.8 in.). Louvers were used for the
back retaining grid.
The bed was packed with 1.6 mm diameter alumina spheres.
During operation, the granules were continuously removed from the
bed at the bottom with an ejector and were returned to the over-
head hopper manually. The bed could be polarized by connecting
one of the retaining grids to a high voltage power supply and by
grounding the other retaining grid.
The particles were charged by corona wires. Wire diameter
was 0.18 mm (0.007 in.). Ground electrodes were made of 1.25 cm
diameter (0.5 in.) aliaminum rods. Wire/rod spacing was 3.8 cm
(1.5 in.).
One power supply was used both to charge the particle and
to polarize the bed. The applied voltage for all runs was 20 kV
DC. This is equivalent to a field strength of 1.31 kV/cm in the
bed and 5.26 kV/cm in the particle charger.
28
-------
f
OUTLET
SAMPLING
AEROSOL
BLOWER
Figure 16. Moving bed GBF (34.3 m3/min).
-------
DATA
Room air and redispersed fly ash particles were used for
all experiments. The fly ash particles were fed into the blower
inlet. Particle size distribution and concentration were mea-
sured simultaneously at the granular bed filter inlet and outlet
ducts using cascade impactors. Grade penetration was calculated
from impactor data for all runs. Static pressures were measured
with pressure gauges at the inlet and outlet sampling points.
Pressure drop is equal to the difference and therefore includes
the entrance and exit losses.
A total of twenty-one runs were done. Test conditions
included:
1. Neutral bed/uncharged particle
2. Polarized bed/uncharged particle
3. Neutral bed/charged particle
4. Polarized bed/charged particle.
The superficial gas velocity through the bed varied between
45 and 60 cm/s. The ratio "M" of granule mass recirculated to
gas mass flow varied between 0.5 and 1.5.
Test conditions and particle data are summarized in Table 1
•^ •
Cascade impactor dat-a are listed in Appendix "B". Grade penetra-
tion curves are given in Appendix "C".
DATA ANALYSIS
Figure 17 shows the measured particle penetration for var-
ious operating conditions. As with the case of the fixed
granular bed filter, polarizing the bed or charging the particles
resulted in a significant improvement in performance. Simulta-
neous bed polarization and particle charging gave very efficient
collection in excess of 98% for all particle sizes measured.
Large quantities of particles are collected by the outlet
probe. Since the particles collected by the probe are large
they may originate from reentrainment. The grinding of the
granules due to the relative motion of the filter granules can
30
-------
TABLE 1. TEST CONDITIONS AND PARTICLE DATA
Run
No.
1
2
3
4
5
6
7
8
9
10*
11
12
13
U
15
16
17
18
19
20
21
UG
cm/s
45
45
45
45
45
45
45
45
51
51
46
52
52
57
51
46
45
57
57
45
45
M
kg/kg
1.02
0.99
0.98
0.91
1.13
1.00
1.05
1.07
1.05
1.00
1.16
0.58
0.63
1.06
0.51
0.72
0.59
1.55
0.85
1.06
1.06
AP
cm W.C.
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
6.6
6.4
5.8
7.1
7.1
7.9
7.1
5.8
5.9
6.7
8.1
5.6
5.6
Eb
kV/cm
0
0
1.31
1.31
1.31
1.31
0
0
0
0
1.31
0
0
1.31
1.31
0
0
1.31
1.31
1.31
1.31
E
P
kV/cm
0
0
0
0
5.26
5.26
5.26
5.26
0
0
0
0
0
0
0
0
0
0
0
5.26
5.26
V
Inlet
17.0
9.0
8.0
12.0
4.0
3.4
6.0
3.8
5.2
6.0
13.0
7.0
38.0
8.2
10.0
7.2
6.0
9.0
6.0
6.0
6.5
ymA
Outlet
3.5
3.0
60.0
10.0
21.0
15.0
5.0
6.4
3.0
4.0
7.4
4.0
10.0
14.0
20.0
3.0
3.2
23.0
40.0
25.0
35.0
Inlet
5.9
3.3
3.5
5.2
3.1
3.1
3.0
3.5
2.5
3.3
5.7
2.9
5.4
3.2
3.4
2.9
2.9
3.3
2.9
2.3
2.8
°g
Outlet
2.3
2.3
50.0
12.2
14.0
10.0
4.5
5.8
2.5
3.6
21.1
3.2
7.4
5.5
3.3
5.8
3.2
7.0
10.0
17.3
23.3
C, mg/DNm3
Inlet
752.1
530.3
802.3
1,449.0
1,082.0
1,446.0
1,311.0
1,111.0
444.9
497.6
387.6
463.1
1,171.0
1,067.0
1,102.2
751.2
530.3
461.0
547.5
446.7
684.1
Outlet
115. 2
97.1
38.9
69.3
38.1
32.3
75.8
81.0
54.1
188.4
43.6
44.3
38.6
61.1
53.0
115.2
99.1
47.6
34.6
49.0
39.5
Pt, %
15.3
18.3
4.8
4.8
3.5
2.2
5.8
7.3
12.2
37.9
11.2
9.6
3.3
5.7
4.8
15.3
18.3
10.3
6.3
11.0
5.8
Note: Dirty granules
-------
(3
o
•H
U
U
^
(-H
i
i—i
I
H
UJ
UJ
PL,
NEUTRAL BED/
NEUTRAL PARTICI
POLARIZED BED/ i 1 MiTrrr
NEUTRAL PARTICLE
NEUTRAL BED/
CHARGED PARTICLE
d = 1.6 mm
M = 1.0
AP = 5.6 cm W.C.
AEROSOL: FLY ASH
POLARIZED BED/
CHARGED PARTICI
SHE
0.01
1.0 5.0 10.0
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure 17. Measured particle penetration for various
opening conditions of a GBF.
32
-------
dislodge the collected particles and allow them to be reentrained
into the gas stream. The reentrainment rate depends on the gran-
ule recirculation rate and the filtration gas velocity. At higher
recirculation rates,collected particles are easier to dislodge.
Electrically augmenting the bed and/or particles did not
minimize reentrainment.
Figures 18 and 19 show the effect of granule recirculation
rate on particle penetration. Lower recirculation rate results
in lower particle penetration and higher pressure drop. This
could be a result of a smaller bed porosity for a bed with a lower
recirculation rate. According to Ergun's equation for pressure
drop across a packed bed and Equation (1), smaller bed porosity
leads to higher pressure drop and particle collection efficiency.
Beds with lower recirculation rate also result in less
attrition of retaining grids and granules and less dislodging
and reentraining of the collected particles. Therefore, the
granule recirculation should be kept as slow as possible. How-
ever, it should not be so slow that the collected particles will
saturate the bed. The drag force exerted on the collected par-
ticles by the gas flow will gradually force the collected par-
ticles through from the dirty to the clean side of the filter.
As the deposit extends through the bed, the bed can become satur-
ated with dust and reentrainment may result causing the collection
efficiency to decrease.
The final selection of the granule recirculation rate depends
on the gas velocity, inlet particle concentration, bed depth, bed
height and granule size.
Figure 20 shows the effect of granule cleanliness on pene-
tration. The dirty granules had been circulated through the bed
twice without cleaning. As expected, dirty granules result in
higher penetration. This occurs presumably because particles are
reentrained from the downstream side of the bed.
Figure 21 shows the comparison of measured penetration for
a fixed and a moving granular bed filter. The fixed bed
data were reported earlier in Section 3. As can be seen, a fixed
33
-------
c
o
•H
<-•
O
03
2
O
H
w
Z
w
OH
GRANULE RECIRCULATION
RATE
1.0 kg/kg
0.72 kg/kg
AP = 5.8 cm W.C
M = 0.59 kg/kg
AP = 5.9 cm W.C.
ii. u,, = 45 cm
Z = 15 cm
3
•rt d = 1.6 mm
AEROSOL FLY ASH
NEUTRAL BED/NEUTRAL PARTICLE !
0.5 1.0 5.0
AERODYNAMIC PARTICLE DIAMETER, ymA
10.0
Figure 18. Effect of granule recirculation rate on
penetration.
34
-------
1.0
c
o
•H
u
u
S
H
w
w
(X
Z = 15 cm
d = 1.6 nun
AEROSOL: FLY ASH
POLARIZED BED/NEUTRAL PARTICLE
1.55 kg/kg
6.7 cm W.C
M = 1.06 kg/kg^|j
AP = 7.9 cm W.C.
M = 0.85 kg/kg
AP = 8.1 cm W.C.
0.5 1.0 5.0
AERODYNAMIC PARTICLE DIAMETER, ymA
10.0
Figure 19. Effect of granule recirculation rate on pene-
tration.
35
-------
1.0
DIRTY GRANULES
CIBAN GRANUL
Z = IS cm
d = 1.6 mm
M = 1 kg/kg
AP = 6.5 cm W.C.
AEROSOL FLY ASH
NEUTRAL BED/NEUTRAL PARTICLE
inn rim
0.01
0.3 1.0 3.0
AERODYNAMIC PARTICLE DIAMETER,
10.0
Figure 20. Effect of granule cleanliness on
penetration.
36
-------
1.0
Z = 10.2 cm
M = 0
AP. - 3.0-5.5 cm W.C
(FIXED BED)
Z = 15 cm
M = 1.05 kg/kg
AP = 6.6 cm W.C.
(MOVING BED);
d = 1.6 mm
AEROSOL: FLY ASH
NEUTRAL BED/NEUTRAL PARTICLE
°-5 1.0 s.O
AERODYNAMIC PARTICLE DIAMETER, ymA
10.0
Figure 21. Measured penetrations of a fixed bed and a
moving GBF.
37
-------
bed with a bed depth of 10.2 cm has the same capability as a
moving bed with a bed depth of 15 cm and a granule rccirculation
rate of 1 kg/kg.
Effects of gas velocity on penetration are shown in Figures
22 and 23. As with fixed bed, higher gas velocity gives lower
penetration.
38
-------
51 cm/s
6.6 cm W.C
d = 1.6 nun
M = 1 kg/kg
AEROSOL: FLY ASH
NEUTRAL BED/NEUTRAL PARTICLE
0.1
0.5 1.0 5.0 10.0
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure 22. Effect of gas velocity on penetration.
39
-------
c
o
•H
4J
U
id
§0
H
W
w 0
0
M = 0.65 kg/kg j
..:;: ,:j: : mi: :
;Up = 52 cm/s
M = 0.6 kg/kg
AP = 7.1 cm W.C.
= 15 cm
d = 1.6 mm
i AEROSOL: FLY ASH
NEUTRAL BED/NEUTRAL PARTICLE
0.5 1.0 5.0
AERODYNAMIC PARTICLE DIAMETER, ymA
10.0
Figure 23. Effect of gas velocity on penetration,
40
-------
SECTION 5
EVALUATION OF ELECTRICAL AUGMENTATION OF
GRANULAR BED FILTERS
The use of granular bed filters for HTP applications is
limited by the particulate and gaseous pollutant removal efficien-
cies and operating difficulties. Particulate cleanup requirements
for HTP processes vary depending on the intended use of the gas.
If it is to be vented, the gas must be cleaned sufficiently to
meet the emission standards. The recently promulgated new source
performance standard for coal-fired boilers is 13 mg/MJ (0.03 lb/
106 BTU).
If the hot gas is to be expanded through a gas turbine, then
the gas must meet the turbine requirement for cleanliness. A gas
containing dust particles can severely erode and corrode turbine
blades and other internal blades can impair the aerodynamic per-
formance of the turbine.
Turbine requirements are not well established at this time.
Westinghouse (1974) suggested that a mass loading less than 0.37
g/Nm3 (0.15 gr/SCF) for particles smaller than 2 ym in diameter
and less than 0.0023 g/Nm3 (0.001 gr/SCF) for particles larger
than 2 yitu Sverdrup and Archer (1977) estimated that to protect
the turbine, the particulate concentration should be no more than
0.005 g/Nm3 (0.002 gr/SCF) and there should be no particles larger
than 6 um in diameter.
By using the particle size distribution and concentration
reported by Hoke et al. (1977, 1978), Yung et al. (1979) showed
through theoretical calculation that the collection efficiency
of a granular bed filter appears to be insufficient to meet the
new emissions regulations for particulates. Depending on the
amount of submicron particles a turbine can tolerate, performance
may still be satisfactory for protecting gas turbines.
41
-------
The experimental results of the present study and that of
Self et alo (1979) show that the collection efficiency of a
granular bed filter can be dramatically enhanced by electrical
augmentation. By charging the particles and polarizing the bed
to a field of a few kV/cm, the bed could achieve a collection
efficiency of more than 981 for all particle sizes.
These tests were done under ambient conditions. Calvert and
Parker (1977) stated that high temperature and pressure particle
collection is more difficult than at low temperatures when other
parameters remain the same. However, a higher electric field
could be applied to the bed at high temperature. Higher electri
field will lead to a higher collection efficiency.
Hoke (1977) reported that the particles from the secondary
cyclone of the Exxon PFBC (pressurized fluidized bed coal combust
miniplant has a mass median diameter of 3.5 ym and a geometric
standard deviation of 2.9. The mass concentration varies, but
could be as high as 2.5 g/Nm3 (1 gr/SCF). By assuming the elec-
trified GBF has the same fractional penetration at HTP as that at
low temperature and pressure, the overall collection efficiency
of the GBF was calculated to be more than 99.5%. Therefore, th
particle emissions would be 0.013 g/Nm3 (0.005 gr/SCF) and this
would be in .compliance with the particulate emission standards
Quantitative data on the costs of HTP granular bed filters
are not available. The estimated capital costs of an electrifiej
GBF is expected to be slightly higher than that of a non-aided
The added costs are mainly due to the high voltage power supply
electrical insulation and connection systems.
Although electrified granular bed filters have the capabii-
for controlling fine particles at high temperature and pressur
are far from a proven, state-of-the-art technology. There are * *'
operational problems and uncertainties which need to be resolv H
before HTP electrified GBFs can be considered sufficiently rel'
able for commercial application.
42
-------
SECTION 6
FUTURE RESEARCH RECOMMENDATIONS
It has been shown that by electrostatically augmenting
the bed and/or particles, the collection efficiency of the
granular bed filter improved significantly. It has the
potential to meet the most stringent cleanup requirements
under ambient conditions. It is expected that the same
statement will hold for high temperature and high pressure
conditions where higher electric fields can be imposed on the
beds.
However, there are many operational problems and uncer-
tainties which need to be resolved before high temperature
and high pressure granular bed filters can be considered
sufficiently reliable and economical for commercial applica-
tion. Future research and development work is needed in the
following areas:
1. Bed cleaning methods and ways to reduce the cost of
granule regeneration and recirculation.
2. Electrode configuration and high temperature and
high pressure electrode insulation.
3. How to reduce particle seepage through the bed
during cleaning or filtration.
4. How to reduce attrition of granules causing particle
reentrainment.
5. How to reduce temperature losses and pressure drop
across the bed.
Most of these can be studied in the laboratory and the
most promising combination can be tested on a pilot-plant
scale. A detailed program to demonstrate the feasibility of
using electrostatic augmentation to improve granular bed
43
-------
filters for particle collection at high temperature is described
below. We recommend a study of the electrostatically augmented
granular bed filter on a pilot plant scale of about 14.2 Am3/min
C500 ACFM). To duplicate actual industrial application, fresh
test dust should be produced instead of regenerated dust. Since
granular bed filters will be used in advanced energy processes
it is desirable to test the electrostatically augmented granular
bed filter on these processes. A good approach would be to use
an actual fluidized bed combustor (atmospheric or pressurized)
The granular bed filter should be designed in such a way
that it is easy to change from one configuration to another.
Bed cleaning can be achieved either by fluidization or by con-
tinuously withdrawing granules and dust from the bed.
To aid the design of the pilot plant, some small-scale
experimental work should be conducted concurrently, in outline
the objectives consist of the following tasks:
1. Conduct small-scale experiments to obtain design
information.
2. Design the pilot plant.
3. Fabricate, install, and start up the pilot plant.
4. Prepare a detailed test plan describing,
a. The proposed test matrix.
b. The measurement techniques to be used.
c. The data handling methods.
5. Conduct test programs.
6. Analyze data, conduct engineering and cost analyses of
various configurations.
7. Based on the above analyses, design and estimate the
cost of a granular bed filter system for high temperature and
high pressure applications.
8. Recommend a test program to demonstrate a full-scale
granular bed filter system on a high temperature and high pressu
source.
44
-------
REFERENCES
Calvert, S. and R. Parker, "Effects of Temperature and Pressure on
Particle Collection Mechanisms: Theoretical Review,"
EPA 600/7-77-002, January 1977.
Hoke, R.C., et al., "Studies of the Pressurized Fluidized-Bed
*Coal Combustion Process," EPA 600/7-77-107, September 1977.
Hoke, R.C., et al., "Miniplant Studies of Pressurized Fluidized
Bed Coal Combustion: Third Annual Report," EPA 600/7-78-069,
April 1978.
Self, S.A., R.H. Cross, and R.H. Eustis, "Electrical Augmentation
of Granular Bed Filter," HTGL Report No. 112, Department of
Mechanical Engineering, Stanford University, March 1979.
Sverdrup, E.F. and D.H. Archer, "The Tolerance of Large Gas Tur-
bines to Rocks, Dusts, and Chemical Corrodants," presented
at the EPA/ERDA Symposium on High Temperature and Pressure
Particulate Control, Washington, B.C., September 1977.
Westinghouse Electric Corporation, "Clean Power Generation from
Coal," O.C.R., 84, NTIS No. PB 234-188, April 1974.
Yung, S.C., R. Patterson, R. Parker and S. Calvert, "Evaluation
of Granular Bed Filters for High Temperature/High Pressure
Particulate Control," EPA 600/7-79-020, January 1979.
45
-------
APPENDIX A
FIXED BED GBF EXPERIMENTAL DATA
46
-------
BED THICKNESS:-:
1.8 cm :
BED MATERIAL: -28 +35 MESH SAND
AEROSOL: NEUTRALIZED 1.1 ym DIA
POLYSTYRENE LATEX
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-l Experimental particle penetration of a clean,
grounded GBF.
47
-------
1.0
C
•H
M
U
nj
M
••.
L ^
s
EH
W
X
.-.
0.5
0.4
0.3
BED MATERIAL: 1 mm DIA. GLASS BEADS
BED DEPTH: 5.1 cm
AEROSOL: NEUTRALIZED 1.1 ym DIA.
POLYSTYRENE LATEX
i_L ,
10
20 30 40 60
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-2. Experimental particle penetration of a clea
grounded GBF.
48
-------
1.0
e
o
• H
*J
E-
W
z
w
0.5
0.4
0.3
BED MATERIAL:
1.6 mm DIA. ALUMINA
SPHERES
BED THICKNESS: 10.2 cm
AEROSOL: NEUTRALIZED 1.1 ym DIA.
POLYSTYRENE LATEX
•••••i iiiiiiiiiiiiiiiiiiii ••••••••» IIINI HIIIIIII ••••• iiiii iiiii iiiii
10 20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-3. Experimental particle penetration of a clean,
neutralized GBF.
49
-------
1.0
c
o
s
H
w
'..'.
BED DEPTH: 1.8 cm
BED DEPTH: 3.8 cm -
BED MATERIAL: -28 +35 MESH SAND
AEROSOL: CHARGED 1.1 urn DIA. PSL
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-4. Experimental charged particle penetration
through neutral, clean GBF.
50
-------
1.0
c
c
0.5
0.4
* 0.3
0.2
BED DEPTH: 2.5 cm
BED DEPTH: 5.1 cm
0.1
BED MATERIAL: 1 mm DIA. GLASS BEADS
AEROSOL: CHARGED 1.1 ym DIA. PSL
i
j
10 20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-5. Experimental charged particle penetration
through neutral, clean GBF.
51
-------
1.0
.:
O
u
rt
0.5
0.4
0.3
W
PH
0.2
BED DEPTH: 10.2 cm
0.1
BED MATERIAL: 1.6 mm DIA. ALUMINA
AEROSOL: CHARGED 1.1 ym DIA. PSL
10
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-6. Experimental charged particle penetration
through a neutral, clean GBF.
52
-------
1.0
5
•H
«J
U
§
a
SB
w
VOLTAGE ACROSS THE BED
APPLIED
1.8 kV DC
.6 kV DC
.:.!!!!. :-::.:;.::.
'
4.4 kV DC
5.8 kV DC
7.9 kV DC
H
.4 kV DC
BED MATERIAL: -28 +35 MESH SAND
BED DEPTH: 1.8 cm
AEROSOL: NEUTRALIZED 1.1 ym DIA. PSL
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-7. Experimental particle penetration of a clean,
DC polarized GBF.
53
-------
1.0
0.5
0.4
0.3
0
•H
^
U
d
f->
M-l
0.2
w
0.1
0.05
0.04
0.03
:
I
! M L
BED MATERIAL: -28 +35 MESH
SAND
BED DEPTH: 3.8 cm
AEROSOL: NEUTRALIZED 1.1 ym :
DIA. PSL
—
:::
APPLIED VOLTAGE ACROSS THE BED
20 30 40 50 60
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-8. Experimental particle penetration
of a clean,DC polarized GBF.
54
-------
I.OB
APPLIED VOLTAGE ACROSS THE BED =
2.7 kVDC
11 • i' • • i i
4.7 kV DC
8.8 kV DC
^-rr-
BED MATERIAL: 1 mm DIA. GLASS BEADS
BED DEPTH: 5.1 cm
AEROSOL: NEUTRALIZED 1.1 um PSL
O.I1
10
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-9. Experimental particle penetration of a DC
polarized, clean GBF.
55
-------
1.0
c
0.5
0.4
0.3
W
Z
S
0.2
0.1
—
APPLIED VOLTAGE ACROSS THE BED ;
25 kV DC
I
i • :::| :
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED DEPTH: 10.2 cm
AEROSOL: NEUTRALIZED 1.1 ym DIA. PSL
::::::[— , • -f
.
10 20 50 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-10. Experimental particle penetration of a clean
DC polarized GBF.
56
-------
0.3
c.
o
u
IT3
O
0.2
APPLIED VOLTAGE ACROSS THE BED
0.3 kV DC
0.1
0.03
0.02
0.01
10
0.6 kV DC
BED MATERIAL: -28 +35 MESH SAND
BED DEPTH: 1.8 cm
AEROSOL: CHARGED 1.1 ym D1A. PSL
I
1
I
1
t I I
20 30 40 50
SUPERFICIAL GAS VELOCITY, CM/s
100
Figure A-ll. Experimental charged particle penetration
through a clean DC polarized GBF.
57
-------
c
0
• H
4-1
U
2
H
W
W
APPLIED VOLTAGI ACROSS THE BED
BED MATERIAL: -28 +35 MESH SAND
BED DEPTH: 3 . 8 cm
AEROSOL: CHARGED l.lpm DIA. PSL ::
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-12. Experimental charged particle penetration
through a clean, DC polarized GBF.
58
-------
1.0
o
•rH
4->
O
cd
t-l
BED MATERIAL: 1 mm DIA. GLASS BEADS
BED DEPTH: 2.5 cm
AEROSOL: CHARGED 1.1 m DIA. PSL
APPLIED VOLTAGE ACROSS;
THE BED
0.3 kV DC
0.6 kV DC
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-13. Experimental charged particle penetration through
a clean, DC polarized GBF*
59
-------
0.2
0.1
raction
—
•
-
w
§0.04
H
|0.03
w
tx
0.02
0 01
BED MATERIAL: 1 mm DIA. GLASS BEADS
BED DEPTH: 5 . 1 cm
AEROSOL: CHARGED 1.1 ym DIA. PSL
•••;;;
:
: ::
| i H
APPLIED VOLTAGE ACROJ
THE BED
' ' ;
: : : ; ;
1;
. .
HI
.
— . — p — i — • — • — i-
10
-r
• 0
: : : :
.
- • • • .
E: c
.3 kV DC S
^_^ I . i 1 . 1 . ! , i , , i , , , .
H~t~ ' ' T 1 i ! 1 — ! ' ' ' 1 ' '
";T7n;:r;77i,
^4~ ^ , , , , |, ^, g
.6 kV DC 1^
ffi-r^-+
1
"* C1 ~* " '^F —
<
/ . . . .
r-1 1
....
3E33
- j 1 1 .
m /
: 1
"x'*r~
• 1 1
T . ,
=F^
1
-. — ^ —
/
^
,
/
^
•
f
A
\
X
— *
—
I;
*•• • r •
...
tf
TSs
^
-
1 1 . .
X
pf
w
I
' ' 1 1
*
1 1 . . 1 1
' X
o
f
<-
.1,1 -_
— — —
:
. . ... _.
:::
'
, , i
SM tf *
• "jfr
* H~
-
B
f::
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
Figure A-14. Experimental charged particle penetration
through a clean, DC polarized GBF.
60
-------
APPLIED VOLTAGE ACROSS THE BED
16 kV DC
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED DEPTH: 10.2 cm
PARTICULATE LOAD IN BED: 0.31 g/cm2
AEROSOL: NEUTRALIZED 1.1 ym DIA. PSL
0.05
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-15. Experimental particle penetration of a
dirty GBF.
61
-------
1.0
• >
d
~
O
2
•-
UJ
z
w
0.5
0.4
0.3
0.2
0.1
, APPLIED VOLTAGE ACROSS THE BED
F^-
BED MATERIAL: 1.6 mm DIA. ALUMINA
BED DEPTH: 10.2 cm
PARTICULATE LOAD IN BED: 0.5 g/cm2
AEROSOL: NEUTRALIZED 1.1 ym DIA. PSL
10
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-16. Experimental penetration of a dirty, charged
GBF.
62
-------
1.0
c 0.5
o
• H
rt 0.4
I
H
UJ
w
Cu
0.3
0.2
0.1
10
BED MATERIAL: 1.6 nun DIA. ALUMINA
BED DEPTH: 10.2 cm
PARTICIPATE LOAD IN BED: 0.4 g/cm2
AEROSOL: CHARGED 1.1 ym DIA. PSL
20 CO 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-17. Experimental penetration of a dirty,
grounded fixed GBF.
63
-------
c
o
•H
fJ
u
03
o
(—1
H
U4
APPLIED VOLTAGE ACROSS THE BED
BED MATERIAL:
1.6 mm DIA.
ALUMINA
BED DEPTH:
PARTICULATE LOAD IN
BED: 0.31 g/cm2
AEROSOL: CHARGED 1.1 ym
DIA. PSL
10 20 30 40 SO
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-18. Experimental penetration of a dirty
64
-------
1.0
0.5
o 0.4
•H
•»->
PENETRATION, frac
o o o
• • •
(-" to w
:
A
PPLIED VOLTAGE ACROSS TF
11 kV ACt|p:-
BED MATERIAL: 1.6 mm E
BED DEPTH: 10.2 cm
PARTICULATE LOAD IN BEI
AEROSOL: NEUTRALIZED ]
:: :I::;:: :.:... -^_ - ' ,-L-.
IE BEDJ]
ill J i JL- 1 i Jj.
rrft f
. _ _.._.. L
HA. ALUMINA
i: 0.4 g/cm
1 ym DIA. PSL '.
10
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-19. Experimental penetration of an AC charged,
dirty, fixed GBF.
65
-------
1.0
FRATION, fraction
O O 0
W -P* on
e
w
^0.2
n . i
'
- :;::::••
-
1
.* — _ —
: : : :::;•
•
APPLIE]
: : . - • • : :
..,__, — . — . — . — . — , . . .
i , !
'. •
BE
|gp
•
_ —
:::::::::
r— — —
D VOLT;
- • -
i
.
•
iGE A(
kV A
•
•
• ••. . -
:ROS<
-~+ ••*••—
i
s
13
c T
.
....
5 TH
i i i
.
&,
-.-.:-.
. . .
E E
\t
§
•
.ED
(
n4-
I . >.
1 1 '
f
'••-
*
....
—
. . : .
8
....
D MATERIAL: 1.6 mm DIA. ALUMINA
~~—
%
.
.
BED DEPTH: 10.2 cm
i > '
¥P
AE
RTICULATE LOAD IN BED: 0.4 g/cm2
ROSOL: CHARGED 1 . 1 ym DIA. PSL
i 4--1 1 i --I
— -*
•
IT)
....
- --, ,
•
•
• - -
—
.
....
— -
— r*
^fa±
— T
Mi
'
10
20 30 40 50
SUPERFICIAL GAS VELOCITY, cm/s
100
Figure A-20. Experimental penetration of an AC charged,
dirty, fixed GBF.
66
-------
APPENDIX B
CASCADE IMPACTOR PARTICLE DATA
67
-------
TABLE B-l. CASCADE IMPACTOR DATA FOR RUN #1
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
136.4
91.9
84.4
78.0
44.3
19.3
6.8
1.9
0.3
Cum. Particle
Concentration
(mg/DNm3)
753.6
507.7
466.3
430.9
244.8
106.6
37.6
10.5
1.7
Particle
Diameter
(ymA)
27.9
12.2
4.7
2.4
1.4
0.8
0.4
Cum.
Mass
(ing)
17.3
13.4
13.2
12.7
11.7
8.9
2.9
0.2
0
Outlet
Cum. Particle
Concentration
(mg/DNm3)
104.8
81.2
80.0
76.9
70.9
53.9
17.6
1.2
0
Particle
Diameter
(ymA)
29.2
12.8
4.9
2.5
1.5
0.8
0.5
TABLE B-2. CASCADE IMPACTOR DATA FOR RUN #2
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
(mg)
77.8
52.1
51.5
48.3
30.3
11.9
3.4
1.0
0.3
Inlet
Cum. Particle
Concentration
(mg/DNm3)
492.4
329.7
325.9
305.7
191.8
75.3
21.5
6.3
1.9
Particle
Diameter
(ymA)
30.0
13.2
5.1
2.6
1.5
0.9
0.4
Cum.
Mass
(mg)
22.6
16.2
15.9
15.6
14.8
9.4
3.2
1.3
0.6
Outlet
Cum. Particle
Concentration
(mg/DNm3)
96.6
69.2
68.0
66.7
63.3
40.2
13.7
5.6
2.6
Particle
Diameter
(ymA)
24.6
10.8
4.2
2.1
1.3
0.7
0.4
68
-------
TABLE B-3. CASCADE IMPACTOR DATA FOR RUN #3
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
173.3
123.4
115.3
103.2
60.7
27.9
10.2
1.9
0.7
Cum. Particle
Concentration
(mg/DNm3)
802.3
571.3
533.8
477.8
281.0
129.2
47.2
8.8
3.2
Particle
Diameter
(ymA) '
25.6
11.2
4.3
2.2
1.3
0.7
0.4
Outlet
Cum.
Mass
(ing)
12.1
3.9
3.9
3.9
3.7
2.3
1.1
0.8
0.1
Cum. Particle
Concentration
(mg/DNm3)
38.9
12.5
12.5
12.5
11.9
7.4
3.5
2.6
0.3
Particle
Diameter
(ymA)
24.6
10.8
4.2
2.1
1.3
0.7
0.4
TABLE B-4. CASCADE IMPACTOR DATA FOR RUN #4
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
234.8
163.8
144.6
129.5
79.5
49.2
25.6
9.1
2.8
Cum. Particle
Concentration
(mg/DNm3)
1449.0
1010.8
892.4
799.2
490.6
303.6
158.0
56.2
17.3
Particle
Diameter
(ymA)
'
34.1
15.0
5.8
2.9
1.7
1.0
0.5
Outlet
Cum.
Mass
(mg)
21.6
14.0
12.6
11.1
8.5
6.1
4.0
2.5
1.3
Cum. Particle
Concentration
(mg/DNm3)
69.3
44.9
40.4
35.6
27.3
19.6
12.8
8.0
4.2
Particle
Diameter
(ymA)
24.5
10.7
4.2
2.1
1.3
0.7
0.4
69
-------
TABLE B-5. CASCADE IMPACTOR DATA FOR RUN #5
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
180.7
148.3
142.4
137.5
109.8
71.9
38.1
14.8
2.9
Cum. Particle
Concentration
(mg/DNm3)
1,082.0
888.0
852.7
823.3
657.5
430.5
228.1
88.6
17.4
Particle
Diameter
(ymA)
33.6
14.7
5.7
2.9
1.7
1.0
0.5
Cum.
Mass
(mg)
12.0
5.1
5.0
4.7
3.2
2.1
1.3
0.6
0.2
i
Outlet
Cum. Particle
Concentration
(mg/DNm3)
38.1
16.2
15.9
14.9
10.2
6.7
4.1
1.9
0.6
Particle
Diameter
(ymA)
24.4
10.7
4.1
2.1
1.2
0.7
0.4
TABLE B-6. CASCADE IMPACTOR DATA FOR RUN #6
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
164.8
133.9
129.0
98.5
65.4
33.2
8.0
2.1
0.8
Cum. Particle
Concentration
(mg/DNm3)
1446.0
1174.9
1131.9
864.3
573.8
291.3
70.2
18.4
7.0
Particle
Diameter
(ymA)
49.6
4.3
2.5
1.4
0.7
0.5
0.3
Cum.
Mass
(mg)
15.2
7.6
7.2
6.5
4.4
3.0
1.9
0.9
0.3
Outlet
Cum. Particle
Concentration
(mg/DNm3)
32.3
16.2
15.3
13.8
9.4
6.4
4.0
1.9
0.6
Particle
Diameter
(ymA)
24.5
10.7
4.2
2.1
1.3
0.7
0.4
70
-------
TABLE B-7. CASCADE IMPACTOR DATA FOR RUN #7
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
158.6
114.5
106.6
58.3
33.5
12.3
3.2
0.6
0.2
Cum. Particle
Concentration
(mg/DNm3)
1311.0
946.5
881.2
481.9
276.9
101.7
26.5
5.0
1.7
Particle
Diameter
(umA) '
48.4
4.2
2.4
1.4
0.7
0.5
0.3
Cum.
Mass
Og)
33.8
24 .3
24.1
23.4
18.4
11.0
3.0
0.6
0.3
Outlet
Cum. Particle
Concentration
(mg/DNm3)
.75.8
54.5
54.0
52.5
41.3
24.7
6.7
1.3
0.7
Particle
Diameter
(umA)
25.0
11.0
4.2
2.1
1.3
0.7
0.4
TABLE B-8. CASCADE IMPACTOR DATA FOR RUN #8
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
178.9
135.3
132.3
127.6
123.4
77.5
45.5
19.0
4.1
Cum. Particle
Concentration
(mg/DNm3)
1111.0
840.2
821.6
792.4
766.3
481.3
282.6
118.0
25.5
Particle
Diameter
(ymA)
34.2
15.0
5.8
2.9
1.7
1.0
0.5
Outlet
Cum.
Mass
(mg)
25.5
17.6
17.0
16.2
12.3
7.6
2.0
0.4
0.2
Cum. Particle
Concentration
(mg/DNm3)
81.0
55.9
54.0
51.5
39.1
24.1
6.4
1.3
0.6
Particle
Diameter
(ymA)
24.4
10.7
4.1
2.1
1.2
0.7
0.4
71
-------
TABLE B-9. CASCADE IMPACTOR DATA FOR RUN #9
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
Og)
65.4
56.7
55.9
52.2
31.0
9.5
1.8
0
0
Inlet
Cum. Particle
Concentration
(mg/DNm3)
444.9
385.7
380.3
355.1
210.9
64.6
12.2
0
0
Particle
Diameter
(ymA)
25.4
11.1
4.3
2.2
1.3
0.7
0.4
Cum.
Mass
Og)
9.3
7.7
7.7
7.7
6.8
5.1
1.4
0.3
0.1
Outlet
Cum. Particle
Concentration
(mg/DNm3)
54.1
44.8
44.8
44.8
39.6
29.7
8.1
1.7
0.6
Particle
Diameter
(ymA)
28.7
12.6
4.9
2.4
1.5
0.8
0.5
TABLE B-10. CASCADE IMPACTOR DATA FOR RUN #10
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
(mg)
83.6
65.0
62.8
58.4
37.4
16.3
6.9
3.3
1.6
Inlet
Cum. Particle
Concentration
(mg/DNm3)
497.6
386.9
373.8
347.8
222.6
97.0
41.1
19.6
9.5
Particle
Diameter
(ymA)
26.2
11.5
4.4
2.3
1.3
0.7
0.4
Cum.
Mass
(mg)
32.4
23.5
21.9
20.5
18.4
14.5
7.0
3.3
1.5
Outlet
Cum. Particle
Concentration
(mg/DNm3)
188.4
136.6
127.3
119.2
107.0
84.3
40.7
19.2
8.7
Particle
Diameter
(ymA)
28.8
12.6
4.9
2.4
1.5
0.8
0.5
72
-------
TABLE B-ll. CASCADE IMPACTOR DATA FOR RUN #11
Stage
No.
probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
43.8
31.7
30.4
27.8
12.5
9.1
3.2
1.4
1.1
Cum. Particle
Concentration
(mg/DNm3)
387.6
280.5
269.0
246.0
110.6
80.5
28.3
12.4
9.7
Particle
Diameter
(ymA)
28.9
12.7
4.9
2.5
1.5
0.8
0.4
Outlet
Cum.
Mass
(nig)
4.8
4.0
3.3
2.6
2.2
2.0
1.3
1.0
0.9
Cum. Particle
Concentration
(mg/DNm3)
43.6
36.5
30.1
23.7
20.1
18.3
11.9
9.1
8.2
Particle
Diameter
(vimA)
29.2
12.8
5.0
2.5
1.5
0.8
0.5
TABLE B-12. CASCADE IMPACTOR DATA FOR RUN #12
_ _ .
Stage
No.
. — - — •
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
74.1
57.4
53.2
48.2
27.0
9.1
1.9
0.5
0.2
Cum. Particle
Concentration
(mg/DNm3)
463.1
358.7
332.5
301.2
168.7
56.9
11.9
3.1
1.2
Particle
Diameter
(ymA)
24.5
10.7
4.2
2.1
1. 2
0.7
0.3
Outlet
Cum .
Mass
(ing)
8.2
7.0
6.7
6.5
5.4
3.9
1.0
0
0
Cum. Particle
Concentration
(mg/DNm3)
44.3
37.8
36.2
35.1
29.2
21.1
5.4
0
0
Particle
Diameter
(ymA)
27.8
12.2
4.7
2.4
1.4
0.8
0.5
73
-------
TABLE B-13. CASCADE IMPACTOR DATA FOR RUN #13
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(mg)
L88.5
89.5
70.2
50.3
24.1
8.0
2.2
0.9
0.4
Cum. Particle
Concentration
(mg/DNm3)
1171.0
556.0
436.1
312.5
149.7
49.7
13.7
5.6
2.5
Particle
Diameter
(ymA)
24.4
10.7
4.1
2.1
1.2
0.7
0.3
Cum.
Mass
(rog)
7.3
4.2
4.0
3.9
3.4
2.3
0.3
0
0
Outlet
Cum. Particle
Concentration
(mg/DNm3)
38.6
22.2
21.2
20.6
18.0
12.2
1.6
0
0
_ 1
Particle
Diameter
(ymA)
27.5
12.0
4.7
2.3
1.4
0.8
0.5
TABLE B-14. CASCADE IMPACTOR DATA FOR RUN #14
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
(mg)
73.3
50.5
47.3
42.7
23.9
7.9
2.2
0.6
0.3
Inlet
Cum. Particle
Concentration
(mg/DNm3)
461.0
317.6
297.5
268.5
150.3
49.7
13.8
3.8
1.9
Particle
Diameter
(ymA)
24.3
10.6
4.2
2.1
1.2
0.7
0.3
Cum.
Mass
(mg)
9.1
5.5
4.8
4.2
2.5
1.3
0.4
0.2
0
Outlet
Cum. Particle
Concentration
(mg/DNm3)
47.6
28.8
25.1
22.0
13.1
6.8
2.1
1.0
0
Particle
Diameter
(ymA)
27.1
11.9
4.6
2.3
1.4
0.8
0.5
74
-------
TABLE B-15. CASCADE IMPACTOR DATA FOR RUN #15.
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
205.0
155.3
149.9
101.3
46.5
11.5
2.2
0
0
Cum. Particle
Concentration
(mg/DNm3)
1102.2
835.0
806.0
544.6
250.0
61.8
11.8
0
0
Particle
Diameter
(ymA)
22.5
9.9
3.8
1.9
1.1
0.6
0.3
Outlet
Cum.
Mass
Og)
9.7
3.0
2.6
2.1
1.5
0.9
0.1
0
0
Cum. Particle
Concentration
(mg/DNm3)
53.0
16.4
14.2
11.5
8.2
4.9
0.6
Particle
Diameter
(ymA)
27.7
12.1
4.7
2.3
1.4
0.8
0.5
1
TABLE B-16. CASCADE IMPACTOR DATA FOR RUN #16
_. — •
Stage
No.
•
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
130.7
98.6
90.1
82.7
47.0
20.1
6.9
1.5
0.5
Cum. Particle
Concentration
(mg/DNm3)
751.2
566.7
517.8
475.2
270.1
115.5
39.7
8.6
2.9
Particle
Diameter
(ymA)
28.6
12.5
4.8
2.4
1.4
0.8
0.4
Outlet
Cum.
Mass
Og)
18.9
16.2
15.2
14.8
13.7
11.2
5.5
2.3
1.4
Cum. Particle
Concentration
(mg/DNm3)
115.2
98.7
92.6
90.2
83.5
68.3
33.5
14.0
8.5
Particle
Diameter
(ymA)
29.3
12.8
5.0
2.5
1.5
0.8
0.5
75
-------
TABLE B-17. CASCADE IMPACTOR DATA FOR RUN #17
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
(nig)
76.9
60.3
59.7
56.9
32.4
12.9
3.8
1.5
0.7
Inlet
Cum. Particle
Concentration
(mg/DNm3)
530.3
415.8
411.7
392.4
223.4
89.0
26.2
10.3
4.8
Particle
Diameter
(ymA) '
25.7
11.3
4.4
2.2
1.3
0.7
0.4
Cum.
Mass
(mg)
16.7
11.4
11.4
11.4
11.0
8.6
2.6
0.2
0
i
Outlet
Cum. Particle
Concentration
(mg/DNm3)
97.1
66.3
66.3
66.3
64.0
50.0
15.1
1.2
0
Particle
Diameter
(ymA)
28.8
12.6
4.9
2.4
1.5
0.8
0.5
TABLE B-18. CASCADE IMPACTOR DATA FOR RUN #18
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Cum.
Mass
(mg)
144.1
97.6
95.1
84.7
44.8
15.6
3.5
0.3
0.1
Inlet
Cum. Particle
Concentration
(mg/DNm3)
1067.0
722.7
704.2
627.2
331.7
115.5
25.9
2.2
0.7
Particle
Diameter
(ymA)
26.7
11.7
4.5
2.3
1.3
0.8
0.4
Cum.
Mass
(mg)
11.3
5.7
4.8
4.2
2.6
1.6
0.4
0.1
0
Outlet
Cum. Particle
Concentration
(mg/DNm3)
61.1
30.8
26.0
22.7
14.1
8.7
2.2
0.5
0
Particle
Diameter
(ymA)
27.8
12.2
4.7
2.3
1.4
0.8
0.5
76
-------
TABLE B-19. CASCADE IMPACTOR DATA FOR RUN #19.
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
86.5
66.6
65.2
61.3
36.5
12.6
2.8
0.5
0.4
Cum. Particle
Concentration
Og/DNm3)
547.5
421.5
412.7
388.0
231.0
79.8
17.7
3.2
2.5
Particle
Diameter
(ymA)
24.5
10.7
4.2
2.1
1.2
0.7
0.3
Outlet
Cum.
Mass
(mg)
6.5
2.1
1.9
1.9
1.3
0.8
0.2
0.1
0.1
Cum. Particle
Concentration
(mg/DNm3)
34.6
11.2
10.1
10.1
6.9
4.3
1.1
0.5
0.5
Particle
Diameter
(ymA)
27.4
12.0
4.6
2.3
1.4
0.8
0.5
TABLE B-20. CASCADE IMPACTOR DATA FOR RUN #20.
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
Og)
88.9
71.0
70.5
64.3
31.7
7.8
1.0
0.3
0
Cum. Particle
Concentration
(mg/DNm3)
446.7
356.8
354.2
323.1
159.3
39.2
5.0
1.5
0
Particle
Diameter
(ymA)
21.8
9.6
3.7
1.9
1.1
0.6
0.3
Outlet
Cum.
Mass
(mg)
7.7
1.0
0.7
0.6
0.4
0.2
0.1
0
0
Cum. Particle
Concentration
(mg/DNm3)
49.0
6.4
4.5
3.8
2.5
1.3
0.6
0
0
Particle
Diameter
(ymA)
24.5
10.7
4.2
2.1
1.3
0.7
0.4
77
-------
TABLE B-21. CASCADE IMPACTOR DATA FOR RUN #21
Stage
No.
Probe
1
2
3
4
5
6
7
Filter
Inlet
Cum.
Mass
(nig)
86.2
64.9
63.8
61.2
38.0
14.1
3.6
0.6
0.2
Cum. Particle
Concentration
(mg/DNm3)
684.1
515.1
506.3
485.7
301.6
111.9
28.6
4.8
1.6
Particle
Diameter
(ymA) '
27.4
12.0
4.7
2.4
1.4
0.8
0.4
Cum.
Mass
(™g)
5.8
1.0
0.8
0.8
0.5
0.3
0
0
0
Outlet
Cum. Particle
Concentration
(mg/DNm3)
39.5
6.8
5.4
5.4
3.4
2.0
0
0
0
Particle
Diameter
(ymA)
31.0
13.6
5.3
2.6
1.6
0.9
0.6
78
-------
APPENDIX C
EXPERIMENTAL GRADE PENETRATION CURVES OF THE
MOVING BED GRANULAR BED FILTER
79
-------
1.0
0.5
a
o
U
flj
JH
- 0.1
o
. 05
w
pt,
u,, = 45 cm/s
u
= 15 cm
d =1.6 mm
c
M = kg/kg
AP = 5.6 cm W.C.
AEROSOL: FLY ASH
NEUTRAL BED/UNCHARGED PARTICLE
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-l. Experimental grade penetration curves
of the moving GBF.
80
-------
1.0
POLARIZED BED (Eb = 1
cm)/NEUTRAL PARTICLE
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-2. Experimental grade penetration curves
of the moving GBF.
81
-------
c
0
•r-t
u
u
rt
H
W
X.
w
1.0
0.5
0.1
0.05
0.01
0.005
= 45 cm/s
Z = 15 en
d 1.6 mm
M 1.06 kg/kg
AP = 5.6 cm W.C.
AEROSOL: FLY ASH
POLARIZED BED (Eb
CHARGED AEROSOL
1.3 ky/cm)/
0.001
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-3. Experimental grade penetration curves
of the moving GBF.
82
-------
0
•H
•M
•J
rt
f-l
H
—
Z
w
= 45 cm/s
Z = 15 cm
d = 1.6 mm
M = 1.05 kg/kg
AP = 5.6 cm W.C.
AEROSOL: FLY ASH
NEUTRAL BED/CHARGED PARTICLE:
0.05
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-4. Experimental grade penetration curves
of the moving GBF.
83
-------
1.0
0.5
G
o
u
a
^
X
O
0.1
H
H 0.05
w
G = 51 cm
Z = 15 cm
M 1.02 kg/kg
AP = 6.5 cm W.C.
AEROSOL: FLY ASH
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-5. Experimental grade penetration curves
of the moving GBF.
84
-------
1.0
0.5
c
o
o 0.1
H
W
5 0.05 L,
0.01
U 46 cm/s
Z = 15 cm
dc = 1.6 mm
M = 1 16 kg/kg
AP = 5.8 cm W.C.
AEROSOL: FLY ASH
POLARIZED BED/
UNCHARGED PARTICLE
nirnrnimraiiiiiiMimiinr
nmiiraimiiiHrimniiiniinii
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-6. Experimental grade penetration curves
of the moving GBF.
85
-------
1.0
u~ = 52 cm/s
b
Z = 15 cm
d =1.6 mm
M = 0.6 kg/kg
AP = 7.1 cm W.C.
AEROSOL: FLY ASH
NEUTRAL BED/
UNCHARGED PARTICLE
0.01
0.3 0.5 i.o 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-7. Experimental grade penetration curves
of the moving GBF.
86
-------
1.0
0.5 I
c
o
•J
(T!
2 o.i
i
H
W
«0.05
POLARIZED BED/
UNCHARGED PARTICLE
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-8. Experimental grade penetration curves
of the moving GBF.
87
-------
§
•H
*J
u
a)
o
1-1
f-
w
(X
1.0
0.5
0.1
0.05
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-9. Experimental grade penetration curve
of a moving GBF.
88
-------
1.0
0.5
c
o
•H
4J
L)
2 0.1
o
H
§ 0.05
0.01
= 46 cm/s
Z = 15 cm
IG = 1.6 mm
M = 0.72 kg/kg
AP = 5.8 cm W.C.
|JjAEROSOL: FLY ASH
NEUTRAL BED/
UNCHARGED PARTICLE
Milllill
I
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-10. Experimental grade penetration curve
of a moving GBF.
89
-------
1.0
0.5
c
o
sfl
2 o.i
H
W
0.05
RUN #17
u^ = 45 cm/s
b
Z = L5 cm
d = 1. 6 mm
jgjffi C
M = 0.59 kg/kg
AP = 5.9 cm W.C.
AEROSOL FLY ASH
iNEUTRAL BED/
i UNCHARGED PARTICLE .:
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-ll. Experimental grade penetration curve
of a moving GBF.
90
-------
1.0
G = 57 cm/s
Z = 15 cm
d = 1.6 mm
M 1.06 kg/kg
AP = 7.9 cm W.C.
AEROSOL: FLY ASH
POLARIZED BED/UNCHARGED PARTICLE
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-12. Experimental grade penetration curve
of a moving GEF.
91
-------
1.0
0.5
c
o
U
cfl
2!
O
H
U-l
X
UJ
0.1
0.05
|f|Up = 57 cm/s
Z = 15 cm
d = 1.6 mm
M = 0.85 kg/kg
AP = 8.1 cm W.C.
AEROSOL: FLY ASH
POLARIZED BED/UNCHARGED PARTICLE
0.01
0.3 0.5 1.0 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-13. Experimental grade penetration curve
of a moving GBF.
92
-------
1.0
0.5
c
o
•H
«J
U
cd
0.1
0.05
3
H
W
z
w
0.01
o.oos ii
0.001
d = 1.6 mm
M = 1.06 kg/kg
AP = 5.6 cm W.C.
>OLARIZED BED/ CHARGED PARTICLE
m
0.3 0.5 i.o 5 10
AERODYNAMIC PARTICLE DIAMETER, ymA
Figure C-14. Experimental grade penetration curves
of a moving GBF.
93
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO.
EPA-600/7-80-035
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Participate Control at High Temperature and
Pressure Using Augmented Granular Bed Filters
5. REPORT DATE
February 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Shui-Chow Yung, R. G. Patterson, and Seymour
Calvert
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
A.P.T. , Inc.
4901 Morena Boulevard, Suite 402
San Diego, California 92117
10. PROGRAM ELEMENT NO.
EHE624A
11. CONTRACT/GRANT NO.
68-02-2183
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
Final; 12/78 - 12/79
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES IERL_RTP project officer is Dennis C. Drehmel, Mail Drop 61
919/541-2925. H '
16. ABSTRACT
The report gives results of experimental measurements (in fixed- and
moving-bed filters) of the effect of electrostatic augmentation on granular bed filter
particle collection efficiencies. Experimental findings included: (1) either polarizing
the bed or charging the particles significantly increased the collection efficiency of
the filter (efficiency increased with increasing applied voltage across the bed); (2)
both polarizing the bed and charging the particles caused the bed to become very
efficient i.n collecting particles (efficiency of a 15 cm deep bed of 1.6 mm diameter
alumina spheres with a polarizing field strength of 1. 31 kV/cm was above 98% for all
particle sizes); (3) polarizing the bed and. or charging the particles has no effect on
pressure drop across a clean bed; (4) a filter cake increases the collection efficiency
of the granular bed filter (the increase depends on the cake structure and the amount
of dust retained in the bed); (5) DC polarization is much more effective than low
frequency AC polarization; and (6) fixed bed filters show a higher collection efficien-
cy and a higher pressure drop than moving beds (in moving beds, lower recirculation
rates also have lower rates of attrition of retaining grids and granules and lower
rates of dislodging and reentraining the collected particles).
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Dust
Aerosols
Filtration
ranular Materials
Electrostatics
Polarization
Aluminum Oxide
Pollution Control
Stationary Sources
Particulates
Granular Bed Filters
13B
11G
07D
20C
07B
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
20. SECURITY CLASS (Thispage)
Unclassified
21. NO. OF PAGES
104
22. PRICE
EPA Form 2220-1 (9-73)
94
------- |