EPA-650/2-74-083-a
June 1975 Environmental Protection Technology Series
DYNACTOR SCRUBBER
EVALUATION
&
**
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UJ
a
U.S. Environmental Protection Agency
Office of Research and Development
Washington. D.C. 20460
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EPA-650/2-74-083-0
DYNACTOR SCRUBBER
EVALUATION
by
D. W. Cooper and D. P. Anderson
GCA Corporation
GCA Technology Division
Burlington Road
Bedford, Massachusetts 01730
Contract No. 68-02-1316
Task 6
ROAP No. 21ADL-004
Program Element No. 1ABO12
EPA Project Officer: D.L.Harmon
Control Systems Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
WASHINGTON, D. C. 20460
June 1975
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EPA REVIEW NOTICE
This report has been reviewed by the National Environmental Research
Center - Research Triangle Park, Office of Research and Development,
EPA, and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environ-
mental Protection Agency, have been grouped into series. These broad
categories were established to facilitate further development and applica-
tion of environmental technology. Elimination of traditional grouping was
consciously planned to foster technology transfer and maximum interface
in related fields. These 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
9. MISCELLANEOUS
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to
develop and demonstrate instrumentation, equipment and methodology
to repair or prevent environmental degradation from point and non-
point sources of pollution. This work provides the new or improved
technology required for the control and treatment of pollution sources
to meet environmental quality standards.
This document is available to the public for sale through the National
Technical Information Service, Springfield. Virginia 22161.
Publication No. EPA-650/2-74-083-a
ii
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ABSTRACT
A novel aspirative spray scrubber, the Dynactor (RP Industries, Hudson,
Massachusetts), was tested for power consumption and collection effi-
ciency at three flow rates, two temperatures, two dust loading levels,
for two different dusts. Higher efficiencies were fostered by: lower
flow rate, lower inlet temperature, and higher mass loading. The col-
lection efficiency of the Dynactor was not substantially different from
that expected for a well-designed venturi scrubber operating at the same
power level and air flow rate. As with other scrubbers of similar power
consumption, collection efficiency decreased sharply for fine particles
smaller than 1 um aerodynamic diameter.
ill
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CONTENTS .
Page
Abstract
List of Figures v
List of Tables vil
Acknowledgments **
Sections
I Conclusions 1
II Recommendations 2
III Introduction . 3
IV Test Equipment and Procedure 5
V Results 22
VI Discussion 57
VII References 72
IX Appendixes 7*
iv
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FIGURES
No. Page
1 Teat System for Dynactor Two-Stage Scrubber Evaluation,
Including Filter Samplers (F), Thermometers (T), and
Pressure Gauge (P) 6
2 Details of Aerosol Concentration and Size Distribution
Measurement Sections ' 7
3 Cumulative Mass Size Distribution of Iron Oxide Pigment
Aerosol as Determined by Two Impactors (#4601 and #4602)
with Original Substrates and with Reclaimed Substrates.
Aerosol Generated by Wright Dust Feeder 13
4 Flow Velocity Profile in Inlet Ducting, Dynactor Test
Setup 18
5 Flow Velocity Profile in Outlet Ducting, Dynactor Test
Setup 20
6 Volume Flow Rate Versus Center-Line Reading With Pitot
Tube, Dynactor Test Setup 21
7 Pressure Gain Produced by Dynactor Versus Flow Rate
through It 24
8 Dynactor Spray Flow and Nozzle Power Dissipation Versus
Spray Pressure 26
9 Inlet Size Distribution, Iron Oxide at 0.47 m3/s
(1000 cfm) 29
10 Inlet Size Distribution, Fly Ash at 0.47 tnVs (1000 cfm) 31
.11 Outlet Size Distribution, Iron Oxide Aerosol at
0.47 m3/s (1000 cfm) 32
12 Outlet Size Distribution, Fly Ash at 0.47 m3/s (1000 cfm) 33
13 Dynactor Scrubber Collection Efficiency Versus Particle
Aerodynamic Diameter, Effects of Loading and Dust Type . 46
14 Dynactor Scrubber Collection Efficiency Versus Particle
Aerodynamic Diameter, Effects of Flow Rate and Inlet
Temperature ,47
15 Collection Efficiency, 1.3-2.5 urn, Versus Flow for Dif-
ferent Dusts, Temperatures, and Concentrations 50
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FIGURES (Continued)
No. Page
16 Dynactor Collection Efficiency Versus Aerodynamic Diameter,
Averages of Data for Iron Oxide at 0.28 m3/s (500 cfm) 59
17 Dynactor Collection Efficiency Versus Aerodynamic Diameter,
Averages of Data for Fly Ash at 0.28 m3/s (500 cfm) 60
18 Dynactor Collection Efficiency Versus Aerodynamic Diameter,
Averages of Data for Iron Oxide at 0.47 m3/s (1000 cfm) 61
19 Dynactor Collection Efficiency Versus Aerodynamic Diameter,
Averages of Data for Fly Ash at 0.47 m3/s (1000 cfm) 62
20 Dynactor Collection Efficiency Versus Aerodynamic Diameter,
Averages of Data for Iron Oxide at 0.71 m3/s (1500 cfm) 63
21 Aerodynamic Cut Diameter Versus Pressure Drop Across Scrub-
ber or Power per Unit Volume Flow, Adapted From Calvert
(1974).3 Lines 2a and 2b are for Venturi Scrubbers.
Dynactor Scrubber Data Averages are Denoted by +'s 66
A-l Single-stage Dynactor Diffusion System Cross Sectional
View 76
A-2 Two-Stage Dynactor 78
vi
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TABLES
No.
1 Data From Two Andersen Mark III Cascade Impactors Sampling
Same Iron Oxide Aerosol (Mapico Black) at 28 -0pm (1 cfm,
0.47 x 103 m3/s) on New Media 11
2 Data From Two Andersen Mark III Cascade Impactors Sampling
Same Iron Oxide Aerosol (Mapico Black) at 28 Ipm On Re-
claimed Media (Final Flow in #4601 Was About 5 Percent
Less Than That of #4602) 12
3 Andersen Model III Impaction Substrate Losses 15
4 Dynactor Air-Moving Capabilities: Flow With Inlet and
Outlet Open to Atmosphere, Maximum Pressure Gain
(No Air Flow) 25
5a Test Matrix, Fly Ash Aerosol 34
5b Test Matrix, Iron Oxide Aerosol 34
6 Summary of Results of 16 Collection Efficiency Tests for
Dynactor (Factorial Test Design) 36
7a-g Results of Statistical Analysis on Efficiency 38
8 Significance of Effects of Flow, Dust, Temperature and
Concentration on Scrubber Collection Efficiency 45
9 Detailed Analysis of Interactions for Dynactor Efficiency
on 1.3-2.5 urn Aerosol Fraction (Stage #6) 49
10 Estimates of Experimental Error for Single Test From the
Residuals of the Sum of Squares and From the Replication
Tests, Nos. 16, 17, 18 52
11 Results of Dynactor Collection Efficiency Tests Under
Similar Conditions Except for Flow Rate (Iron Oxide,
~ 1 g/m3) 53
12 Results of Dynactor Collection Efficiency Tests Under
Similar Conditions but With and Without Steam Addition
(Iron Oxide, 500 cfm - 0.24 m3/s, Loading ~ 1 g/m3) 55
13 Results of Dynactor Collection Efficiency Tests Under
Similar Conditions Except For The Addition of 10 ppm
Surfactant to the Spray Water 56
vil
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TABLES (Continued)
No, Page
14 Best Case and Worst Case Average Efficiencies For Dynactor
Scrubber Tests for Fly Ash and Iron Oxide at Three Flow
Rates 65
vill
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ACKNOWLEDGMENTS
Information and support supplied by Stanley Rich, Vice President and
Technical Director of RP Industries, and by Dale L. Harmon of Control
Systems, Environmental Protection Agency, are acknowledged and were
appreciated. '
ix
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SECTION I
CONCLUSIONS
This evaluation was one of a series of such evaluations being conducted
by the Control Systems Laboratory of the Environmental Protection Agency
to identify and test novel devices which are capable of high efficiency
collection of. fine particulates. The test methods used were not the
usual compliance-type methods but were, rather, state-of-the-art tech-
niques for measuring efficiency as a function of particle size using
cascade impactors upstream and downstream from the control device. The
Dynactor was not found to be substantially different in efficiency from
venturi scrubbers, which also produce collection of particles by spray
droplets that are in motion relative to the gas stream. As shown in
Figure 21 of this report, Che power consumption for the Dynactor was not
substantially different from that for a well-designed venturi scrubber
giving the same particulate collection efficiency. The following were
associated with higher scrubber collection efficiency: lower inlet
temperature, lower air flow rate, higher particle mass concentration,
higher nozzle pressure, and the addition of surfactant material.
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SECTION II
RECOMMENDATIONS
In those applications for which a scrubber might be suitable, the use o|
a Dynactor scrubber could be considered.
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SECTION III
INTRODUCTION
This work was done to evaluate the Dynactor scrubber with respect to its
mass collection efficiency as a function of particle size, the effect
of several parameters on this efficiency, the air-moving capability and
power consumption of the device, and its cost.
The Dynactor uses a proprietary nozzle design to produce a water spray
which serves as an air eductor and as a scrubber, thus cleaning and pro-
pelling the gas simultaneously. A description of the Dynactor, written
by its manufacturer (RP Industries, Hudson, Massachusetts), is in Appen-
dix A. We tested one of the smaller units of its type, a two-stage de-
2
vice with a nominal rating of 0.47 m /s (1000 cfm), Model DY 12 F2.
The Dynactor was installed in a test setup at GCA/Technology Division
and the following measurements were made:
Air flow and pressure gain versus spray nozzle pressure
f Electrical, power consumption versus spray nozzle pressure
Mass collection efficiency as a function of particle aero-
dynamic diameter at two levels of flow, temperature, and
concentration, for two different dusts, in a balanced
test matrix
MASS collection efficiency as a function of particle size
for several additional sets of conditions
Total mass collection efficiency at the conditions^ noted
above
The dust was generated by a dust feeder - air ejector combination. Dust
concentration was determined by gravimetric analysis of filter samples
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obtained by'isokinetic sampling upstream and downstream from the Dynac-
tor. The concentrations in a set of aerodynamic size intervals were
obtained from gravimetric analysis of samples obtained by identical im-
pact or s, one placed upstream and the other downstream from the Dynactor,
from which data the mass collection efficiency as a function of particle
size was obtained. These data were analyzed using an F-test analysis
of variance to determine which factors had significant influence on
collection efficiency in the various aerodynamic size fractions and to
estimate experimental uncertainty. Flow was measured using pitot tube
traverses and pressure gain was measured using Magnehelic pressure gaugeg
The work also included some cost estimates, from which certain compari-
sons can be made with other control devices. Comparisons with other
experimental results for spray scrubbers have also been made, especially
with regard to which factors can enhance collection efficiency.
4
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SECTION IV
TEST EQUIPMENT AND PROCEDURE
Most of the experimental work was done with the equipment shown in
Figures 1 and 2. This equipment allowed us to measure collection effi-
ciency as a function of particle size as well as the conditions of flow,
concentration, temperature, pressure drop, etc. which prevailed during
the efficiency tests.
Figure 1 gives the overall picture of the test setup. Dust from a
screw feed was picked up by an air ejector/aspirator and blown into
ducting leading to the Dynactor. The flow in the ducting was produced
by the Dynactor and the relatively weak fan of the heater/blower, some-
times in conjunction with the fan shown at the very end of the flow
train. Upstream; the turbulent mixture was sampled five or more duct
diameters from the dust feed by an Andersen Model III cascade impactor,.
usually run with isokinetic flow, and by a filter assembly (glass fiber
absolute filter, 47-mm diameter) which always was operated isokinetic-
ally. An identical sampling combination was used downstream, as de-
scribed more fully in Figure 2. The temperature and pressure of the
mixture entering the Dynactor was measured as was, sometimes, the tem-
perature of the mixture leaving the Dynactor. The pressure drop or
gain across the device was measured. Each of the major components of
the test equipment will be described in greater detail next.
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BEATER/
BLOWER
DUST
FEEDER
©
M-4
STAGE
# 2
STAGE
* 1
Figure 1.
Test system for Dynactor two-stage scrubber evaluation,
including filter samplers (F), thermometers (T), and
pressure gauge (P)
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ISO-KINETIC PROBES
FILTER
HEATED
DRYING
SECTION
L-r.-
THERMOMETER
CONDENSATION
INDICATOR
Figure 2. Details of aerosol concentration and size distribution
measurement sections
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HEATER/BLCWER
The heater burned propane supplied continuously from a pressurized tank.
Propane was selected because its.combustion products are almost exclu-
sively carbon dioxide and water, with a negligible production of carbon
aerosol. The heater was rated at a maximum of 350 x 10 Btu/hr (1.0 x
o
105 watt). Its blower could provide 0.66 m /s (1400 cfm) maximum
flow.
DUST FEEDER AND ASPIRATOR
The dust feeder (Acrison, Inc. Model 120) operated with a vibrating hop-
per that channeled the dust into a cavity from which a screw feeder di-
rected an adjustable constant volume flow to the aspirator. The aspir-
ator was powered with pressurized air at 80 psig (5630 cm WC above
atmosphere) and blew the dust into the main ductwork while deagglomer-
ating the aerosol material.
IMPACTORS
Upstream and downstream from the Dynactor, we used the Andersen Model
III in-stack impactor to size-fractionate the aerosol. Except for early
tests which were run at 28 .2pm (1 cfm or 4.7 x 10~4 m3/s), the impac-
tors were operated at 14 £pm to lessen the likelihood of particle re-
bound, as .advised by its manufacturer. The impactors were used with the
glass fiber media impaction substrates designed for them. (Later in this
report is a description of some tests done to ascertain weight changes
in the impactor substrates due to causes other than the accumulation of
particulate material.) The temperature of the impactor at'the Dynactor
outlet and its drying section (Figure 2) was kept about 20°C above the
temperature of the Dynactor exhaust stream to produce drying of the
droplets present in the exhaust. The drying section volume was 2.4 x
10 m (75 cm long by 6.4-cm diameter), which yielded a residence time
of 10 seconds.
8
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Preliminary tests showed that the concentrations downstream from the
Dynactor scrubber were much lower than those upstream. To obtain
enough material on the downstream impactor for weighing and yet not too
much material on the upstream impactor (to prevent rebound and reen-
trainment), it was necessary to run these impactors for different total
durations, the downstream impactor sampling for about 10 times as long
as the upstream impactor. The total downstream sampling time was divided
into equal intervals, and the upstream samples were taken with their
(shorter) durations centered on the midpoints of the intervals, to lessen
error due to time fluctuations of concentration and to facilitate error
analysis. The upstream samples had to be taken for a fraction of the
total downstream sampling duration to prevent overloading the impactor.
The upstream impactor drifted to a higher flow rate than the downstream
impactor, during the course of the tests. The difference averaged about
10 percent, but was offset by the nearly equal reduction in upstream
sampling volume due to the clean air present in the heating chamber at
the start of each upstream sample. The flow difference would have pro-
duced a 5 percent difference in aerodynamic diameter between the im-
pactors, which was negligible.
The concentrations were determined from weight changes in the filters
and impaction substrates. To ascertain the reproducibility of our weigh-
ing measurements, we made 18 weighings each of two weights, 10 g and 100
mg, over 8 days. We obtained 16 readings of 9.9994 and two of 9.9993 g,
and 14 readings of 0.1000 and four of 0.1001 g, from which we concluded
our reproducibility was better than 0.1 mg.
METTLER BAIANCE (HIS) AND WEIGHING ERRORS
The Mettler balance has a vernier scale which allowed the weight to be
read to 0.1 mg. This would place its precision at about 0.05 mg and the
error in taking the difference of two weights at about 0.1 mg standard
deviation.
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To check whether or not dessication made a substantial difference in
the impactor substrate material, ve made 24 weighings before and after
desiccating the substrates for 24 hours. The mean change in weight
was 0.15 mg loss (for substrates averaging 0.20 g) and 11 of the
24 changes were 0.1 mg. From this we decided to dessicate the substrate
material before making the tare weighing as well as before making the
weighing with the captured particulate material.
Precautions were taken to enhance weighing accuracy for all efficiency
tests. The substrates were dessicated at least 12 hours. A static
charge eliminator was -used in the Mettier analytical balance. The sub-
strates were weighed singly; also, the weights of groups of four were
compared with the sum of the four individual weights. To lessen the
likelihood of the wrong substrate being ascribed to a given impaction
stage, the substrates were numbered so that their last digit was the
same as the stage with which they were to be used.
COMPARISON OF ANDERSEN MARK III IN-STACK CASCADE IMPACTORS
In a comparison test done before the Dynactor efficiency tests, the two
identical impactors were used to sample the same aerosol, iron oxide
powder generated from a Wright dust feeder into a wind tunnel. Each
impactor drew 28 /pm (1 cfm) from a Y-connection that was connected to
a single sampling probe. The results of this test are given in Tables
1 and 2 and in Figure 3. The "reclaimed" media were rinsed in methanol
i '
and reused. The correlation coefficient for the mass captured on the
corresponding stages of the impactors was 0.998, indicating very close
matching. The data also indicate the impaction substrates can be re-
claimed by rinsing with methanol, which is significant, as. they cost
nearly $1.00 apiece.
10
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Table 1. DATA FROM TWO ANDERSEN MARK III CASCADE MPACTORS SAMPLING SAME IRON OXIDE
AEROSOL (MAPICO BLACK) AT 28 .0pm (1 cfm, 0.47 x 103 m3/s) ON NEW MEDIA
Impactor
Stage
T
2
3
4
5
6
7
8
Filter
Total
Mass
Mass collected
Impactor
#4601
0.4
0.3
0.6
0.8
2.0
9.6
3.3
0.1
0.6
17.7
Impactor
#4602
0.2
0.2
0.4
0.7
1.9
9.7 '
3.8
0.2
0.5
17.6
Percentage of
total mass
Impactor
#4601
2
2
3
5
11
54
19
1
3
100
Impactor
#4602
1
1
2
4
11
55
22
1
3
100
Cumulative mass
percentage
Impactor
#4601
2
4
7
12
23
77
96
97
100
Impactor
#4602
1
2
4
8
19
74
96
97
100
Effective
Diameter
(^m)
D50
9.6
6.0
4.0
2.75
1.75
0.9
0.54
0.36
0.0
Correlation coefficient:
0.998
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Table 2. DATA FROM TWO ANDERSEN MARK III CASCADE IMPACTORS SAMPLING SAME IRON
OXIDE AEROSOL (MAPICO BLACK) AT 28 4pm ON RECLAIMED MEDIA (FINAL FLOW
IN #4601 WAS ABOUT 5 PERCENT LESS THAN THAT OF #4602)
Impactor
Stage
1
2
3
4
5
6
7
8
Filter
Total
Mass
Mass collected
Impactor
#4602
0.1
0.1
0.4
0.7
2.2
11.3
3.5
0.1
0.6
19.0 g
Impactor
#4601
0.1
0.1
0.3
0.6
1.8
10.6 '
3.6
0.4
0.6
18.1 g
Percentage of
total mass
Impactor
#4602
1
1
2
3
12
59
18
1
3
100
Impactor
#4601
1
1
2
3
10
59
19
2
3
100
Cumulative mass
percentage
Impactor
#4602
1
2
4 '
7
19
78
96
97
100
Impactor
#4601
1
2
4
7
17
76
95
97
100
Effective
Diameter
(ym)
D50
9.6
6.0
4.0
2.75
1.75
0..9
0.54
0.36
0.0
Correlation coefficient:
0.999
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to
X #4601, RECLAIMED
e #4602, RECLAIMED
+ #4601
A #4602
1.3
.6 -
.35
Ac i
I
90
95
98 99
Figure 3.
2 5 10 20 9O 70
MASS PERCENTAGE LARGER THAN ECD
Cumulative mass size distribution of iron oxide pigment aerosol as determined by
two Impactors (#4601 and #4602) with original substrates and with reclaimed sub-
strates. Aerosol generated by Wright dust feeder
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As we have noted, the standard deviation of the difference between two
weighings (the net weights, that is) should be about 0.1 mg; from the da
in Tables 1 and 2, it can be seen that two-thirds of the net weights foe
the aerosol material caught in the impactors were within 0.1 mg of each
other. The ratios of the weights for corresponding stages diverged from
near unity only when the weights approached 0.1 mg, as expected from
the weighing precision.
These comparison tests show that the impactors are nearly identical in
performance, which is what was desired for the tests of the Dynactor
collection efficiency..
LOSSES FROM IMPACTION SUBSTRATE MATERIAL
Bird et al, have reported that the substrate material used in the im-
pactor, cut from glass fiber filters, showed a tendency to lose weight
In handling and use. At the beginning of our tests we weighed four
such substrates before and after inserting them into and removing them
from the impactor, and we found an average weight loss of 0.1 mg per
substrate. Subsequent tests in which we sampled the aerosols produced
some very lightly loaded substrates that showed weight losses £0.1 mg.
Blowing off the substrates before using them visibly removed some loose
material. Rinsing the substrates in methanol before using them removed
an average of 1 mg of loose solid material per substrate. There was
noticed some losses in weight even with the procedure of rinsing with
methanol, desiccating for 12 hours or more, weighing, using, desiccat-
ing again, weighing again. To estimate this loss we wanted to deter-
mine an average weight loss due to handling and sampling, so we sampled
filtered air for 2 hours at 0.5 cfm. The average loss was 0.23 mg per
substrate. All of these loss tests are tabulated in Table 3.
The first column of Table 3 briefly describes how the impactor sub-
strate material was treated before it was tested; either it was used
14
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Table 3. ANDERSEN MODEL III IMPACTION SUBSTRATE LOSSES
Treatment
'
Untreated
Most washed in
methanol
Washed in methanol
Washed in methanol
Test conditions . ' Weight loss
(and number of substrates) (mg)
Load and unload (4)
Sample aerosols (176)
Sample filtered air (8)
for 2 hours, at am-
bient temperature
Sample filtered air (8)
for 15 minutes, am-
bient temperature
-0.1
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
average loss:
-0.26
-0.1
-0.2
-0.3
-0.4
average loss:
-0.23
-0.1
-0.2
-0.3
average loss:
-0.12
Number
4
8
9
2
2
0
4
2
3
2
1
5
1
1
15
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as it came from the manufacturer (untreated) or it was washed in
metHanoi and dried again. The second column tells how the substrate
was used in the tests: either just loaded into the impactor and then
unloaded immediately o_r loaded, used to sample a test, aerosol as
part of the efficiency tests, and unloaded or_ loaded, used to sample
filtered air, and unloaded.. The weight loss is the difference
between the substrate weight before the test and the weight after the
test; the losses listed for the substrates used to sample the aerosols
are the losses for the substrates which showed any loss, 25 of the 176
substrates from a series of 11 efficiency tests, which substrates were
invariably very lightly loaded (visual inspection). The fourth
column gives the number of substrates having the indicated loss. These
tests led to the following treatment of the data obtained with the
cascade impactor for the analysis of variance tests:
1. Weight changes of 0.3 mg or less were taken to be < 0.3 mg
for calculation of efficiencies, which efficiencies are
given as inequalities.
2. Weight changes of 0.4 mg or more were used without
correction.
Data treatment ±8 discussed in Section VI.
In Section VI, we have made best-case and worst-case analyses of the
weighing errors and substrate weight losses. The best case is obtained
by overestimating the inlet concentration (adding 0.3 mg to the
weight change for possible substrate weight loss and adding 0.1 mg for
precision uncertainty) and underestimating the outlet concentration
(subtracting the 0.1 mg uncertainty). The worst case is obtained by
overestimating the outlet (+0.4 mg) and underestimating the inlet
(-0.1 mg). From the tables and figures in Section VI it can be seen
that the differences between the best-case analysis and the worst-
case analysis are not great enough to change appreciably our conclu-
sions.
16
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DUCTING
3
For the tests conducted at flow rates of 500 cfm (0.24 m /s) and 1000
3
cfm (0.47 m /s) the sheet metal ducting upstream from the Dynactor
was 8 inches in diameter by about 12 feet long (0.20.m diameter by
4 m long) connected to an expander to take it from 8-inch diameter to
16-inch diameter (0.20 m to 0.40 m), followed by a 90° elbow, 6 feet
(2 m) more 16-inch ducting and another 90-degree elbow connected to the
Dynactor inlet. For the 1500 cfm (0.71 m^/s) tests, the first section
was about 8 feet (3 m) of 12-inch diameter (0.30 m) ducting. The
dust feeder was separated from the sampling probes by about 6 feet
(2 m). The Dynactor outlet had a reducer to go from the 16-inch
diameter (0.40 m) ducting to 8-inch diameter ducting (0.20 m), and
the sampling probes were about 3 feet (1 m) from the reduction.
FLOW PROFILES IN DUCTING
The tube inlets for sampling the dust concentrations upstream and down-
stream from the Dynactor scrubber were set up to be no less than four
diameters downstream from flow disturbances and 1.5 diameters upstream.
The flow velocity profiles in the immediate vicinity of the sampling
positions were measured to see that they approximated the turbulent
flow profiles expected. By the Reynolds analogy, such a matching would
be a good indication of fairly homogeneous aerosol mixing. Good mixing
is expected because the Reynolds numbers in the ducting are at least
1 x 10 and the sampling points are about 5 diameters or greater
downstream from the point of aerosol generation. The traverses were
done at the positions labeled "impactor" in Figure 1. Figure 4 shows
the velocity profile obtained at the 8-inch (0.20 m) diameter ducting
upstream (for somewhat different flow rates).
Preliminary tests at the inlet indicated a typical, nearly flat,
turbulent flow profile without the heater blower on, but the flow
17
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X
s
I 0
y
t.4
O 9
I
m
.05 .10 .15
i i
1
f .
i
i
i
i
i
k
L ! 1
10
>j
E
5
2 4 6 8
POSITION ALONG DUCT DIAIVfETER,
inches
Figure 4. Flow velocity profile in inlet ducting,
Dynactor test setup
18
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exhibited swirl once the heater blower was used. Installation of
baffling, two 4-inch diameter (0.10 m) ducting pipes about 2 feet
long (0.2 m) immediately downstream from the blower, virtually
eliminated the swirl effect; Figure 4 was obtained with the blower
on. A more detailed pitot traverse was made at the downstream
sampling position. The-results of eight-point and twelve-point
traverses made downstream are given in Figure 5, along with center-
line measurements. The flow closely approximates the turbulent flow
expected, with no pronounced anomalies. The total volume flow from
the equal-area, eight-point traverse was compared with that from the
equal-area, twelve-point traverse: for the two such comparisons we
made, they agreed within S percent and within 2 percent. Figure 6
shows the centerline measurements made simultaneously with the eight-
point traverse measurements used to characterize Dynactor air-moving
capability; reproducibility was judged adequate for the use of the
centerline pitot reading to set the Dynactor flow at the 0.24, 0.47, 0.71
O
m IB (500, 1000, and 1500 cfm) levels when testing the Dynactor frac-
tional collection efficiency.
The flow rates reported for the Dynactor are actual volume flows rather
than standard volume flows, and they were generally determined by the
center-line reading of the pitot tube in the duct downstream from the
Dynactor.
This completes this section on the equipment used in the Dynactor
evaluation and some of the tests performed on this equipment.
19
-------
X 12-POINT TRAVERSE
0^ 0 8-POINT TRAVERSE
| >
>
8
f*"
g
5-
5L. _ « A A.
"ox ° x 9 x ° x
* 1 0 "
1
1
"* '(t
1
1
1
1 .
10
5
40
' |°ni 6
J- °*
(A
w
S
*"
JU
»
1 &
14 QO
1
" # * ox f xo x o
1 *
1
1
1
1
1
1
1 1 1 II 1 1
10
5
2 4 6 8
POSITION ALONG DUCT DIAMETER,
inches
Figure 5. Flow velocity profile in outlet ducting, Dynactor te«t setup
-------
1000
800
0600
i
400
200
0.5
cm WC
1.0 1.5
2.0
,t-
1 1 1 1
1 II 1
20
I
10
.2 .3 ..*.- .5 .6 7 .8 3 10
.CENTER-LINE PITOT TUBE.
Figure 6. Volume flow rate versus center-line reading
With pitot tube, Dynactor t««t setup
21
-------
SECTION V
RESULTS
INTRODUCTION
This section contains the results of the work done to characterize the
Dynactor's air-moving capabilities, power consumption, and collection
efficiency on a mass basis as a function of particle size, determined
with cascade impactors. In Section VI these results will be dis-
cussed and the Dynactor compared with venturi scrubbers.
AIR-MOVING CAPABILITIES
The Dynactor scrubber acts somewhat like a fan, providing a pressure
boost rather than a pressure drop to air moving through it, up to some
maximum flow which depends upon operating conditions. We tested the
pressure gain from Dynactor inlet to Dynactor outlet with a pressure
gauge connected to the inlet and outlet ports, as shown by P in
Figure 1. The total air flow at 70°F was obtained from eight-point
.equal-area traverses in the 8-inch diameter duct immediately down-
stream from the Dynactor. The manufacturer informed us that the inlet
of the device should not be at a vacuum in excess of 1/2-inch H20
(1.2 cm WC). In our tests, we observed that for pressure differences
across the device on the order of 1-inch H_0 (2.5 cm WC) or greater
there was a significant accumulation of water spray in the upper plenum
chambers of the Device, indicating some disruption of the normal flow
patterns, so only a few tests were done under such conditions. The
22
-------
data for flow -(at 1 atmosphere pressure and 70 F) versus pressure in-
crease are given in Figure 7 for three different spray nozzle pressures)
100, 150, 200 psig (7.0, 10.6, 14.1 x 10 cm WC). The usual operation
of the device, according to the manufacturer, is with pressure differ-
ences less than or about 1/2 inch H.O (1.2 cm WC). Table 4 has the data
for the Dynactor flows with inlet and outlet open to the atmosphere and
the pressure increases to be expected (no flow). The flows were some-
what less than expected by the manufacturer; the maximum pressures
matched expectations.
POWER CONSUMPTION: PUMPS
The power consumption of the Dynactor pumps was measured using an
ammeter, a voltmeter, and an oscilloscope (to determine power factor).
The problems of scaling up the data to a typical application (air flow
^ '
much greater than 1 m /s) are such that it was decided the data might
be misleading so they have not been presented.
POWER CONSUMPTION: DYNACTOR SPRAY NOZZLES
In an aspirative spray scrubber such as the Dynactor, the power for
moving the air through the device.is supplied by the pumps that power
the spray nozzles. The electrical power consumption of an installation
will depend upon the kind of motor and pump used in such systems. A
fundamental measure of power consumption is the intrinsic nozzle power,
the product of the pressure drop across the nozzle and the volume flow
rate of flui4 through the nozzle. The volume.flow through the nozzle
is the product of the fluid average velocity and the nozzle area:
QW - vw A. (1)
The velocity is expected to be proportional to the square rodt of the
pressure (potential flow):
(2)
Figure 8 has the manufacturer's data plotted on a log-log graph to
show flow versus pressure and intrinsic power versus pressure.
23
-------
N/rif
.5xl02 .1-OxlO2 l.5x!02 2.0xl02 2.5xlOJ
yuu i 1 1 1 1 1
<
3
i
600
2
U.
o
jT
o
u.
300
k
A 200 psig - 13.8 x 10S N/m2
X
X A
x
X X A
150 psig x y ' .
A .. ' uk
> x a
X x A
_ 0 X
* A
0 ° A A.
100 psig* X
O
0 ° o
X
.
-
o
1 1 I 1 1
cm WC
1 1 1 1 Ol
.2 .4 .6 .8 IX)
PRESSURE INCREASE. AptwH20
25
20
15
10
1.2
Figure 7. Pressure gain produced by Dynactor versus
flow rate through it
24
-------
Ul
Table 4. DYNACTOR AlR-MQVING CAPABILITIES: FLOW WITH INLET AND OUTLET OPEN TO
ATMOSPHERE, MAXIMUM PRESSURE GAIN (NO AIR FLOW)
Unobstructed flow
cfm
3
m /min
m3/s
Maximum pressure gain
inch HjO
cm WC
Spray nozzle pressure
100 psig
(7.0 x 103 cm WC)
6*40
18.1
0.302
1.0
2.5
150 psig .
(10.6 x 103 cm WC)
780
22.1
0.368
1.5
3.8
200 psig
(14.1 x 103 cm WC)
880
24.9
0.415
2.0
5.0
-------
20
M
10
FLOW
X POWER
.
1 gal /rain
1 psig
1 hp » 0.746 kW
e o
6.31 x 10 m /min
6.89 x 103 N/m2
I i 1 i I
SO GO 70 8090100 200
NOZZLE PRESSURE* psig
.1
300 400
1.0
5
.0
§
w
S
3
Figure 8. Dynactor spray flow and nozzle power
dissipation versus spray pressure
26
-------
The nozzle power dissipation is given by
P « (Ap)3/2 (4)
3
for power P in watts, volume flow in m /s, and pressure drop Ap in
cm WC. To obtain the power in horsepower, use
P. - 5.82 x 10"4 Q P . ,0
hp xgpm psig (5)
where the power is in -horsepower, the flow in gallons per minute, and
the pressure drop in pounds per square inch.
The manufacturer indicated that each nozzle had the following flow
M ^
versus pressure: 6.6 gpm (4.2 x 10" m /s) at 100 psig (7.0 x 10
cm WC), 8.1 gpm (5.1 x 10~4 m3/s) at. 150 psig (10.6 x 103 cm WC),
9.2 gpm (5.8 x 10~4 m3/s) at 200 psig (14.1 x 103 cm WC) .
The power dissipation calculated for these three nozzle pressures is
then: 0.38 hp (0.29 kW), 0.70 hp (0.52 kW) , and 1.00 hp (0.74 kW).
These values for power are also- shown in Figure 8, and are consistent
3/2
with the expected (Ap) ' dependence of power on nozzle pressure.
WATER CONSUMPTION
The maximum amount of water used by the Dynactor is the volume flow
3
rate through the spray nozzles. At 1000 cfm (0.47 m /s), this is
2 x 9.2 gal/min *. 18.4 gal/rain (1.16 x 10"3 m3/s) or 18.4 gallons of
3 -333
water per 1000 ft air treated (2.47 x 10 m water per m air treated) ,
at standard conditions. If this could be recycled, as it was in our
tests, actual consumption would be decreased.
27
-------
TEMPERATURE LIMITATION
In preliminary testing, the Dynactor spray was started and the heater
used to raise the temperature of the inlet gas to 300°F (200°C ± 5°C)
while generating and sampling an iron oxide aerosol at.1 gr/ft^. Al-
though we had hoped to be able to make tests at this temperature, the
obvious damage done to certain plastic materials in the Dynactor made
the device inoperable. It was agreed by all parties that future tests
at elevated temperatures should be done at 200°F.
MASS COLLECTION EFFICIENCY VERSUS PARTICLE SIZE
The remainder of the section on results will contain material from
tests done to determine collection efficiency, by mass, as a function
of particle size, or more precisely as a function of particle aero-
dynamic diameter* The data from these tests are presented in Appen-
dix B. Sizing was done by using Andersen Model III In-Stack Impactors
at 14 fcprn flow rate (0.5 cfm). The material on a given stage of the
impactor was classified as being of an aerodynamic diameter greater
than or equal to the aerodynamic cutoff diameter for that impaction
stage and less than the aerodynamic cutoff diameter of the impaction
stage immediately upstream. The cutoff diameter is the diameter for
which the collection efficiency of the given impaction stage would be
0.50. The cutoff diameters were taken from information supplied by
the impactor manufacturer. Figure 9 shows four measurements of the
inlet cumulative particle size distribution by mass of the iron oxide
pigment (Mapico Black) ae generated by the Acrison
-------
TEST NO
|T^ X-HEAVY GRAIN LOADING, AMBIENT TEMPERATURE
19 O-HEAVY GRAIN LOADING, ELEVATED TEMPERATURE
\Z A-LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
14 V-LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
99
9$
99
90
bl
g 80
0.
>-" 70
O
! 60
O
u
u
40
30
20
10
9
X
e
e
x
O
X
o
x
A
AT
r i i
i 1 i 51
I I «
«l 10
13.7
AERODYNAMIC DIAMETER,
Figure 9. Inlet size distribution, iron oxide at 0.47 m /s (1000 cfm)
29
-------
interval, thus eliminating most of the effect of variations in inlet
size distribution on collection efficiency. . Outlet size distributions
are shown in Figures 11 and 12.
Fractional Efficiency of Collection; Factorial Tests .
A factorial test design was used to determine the Dynactor efficiency
and the effects, if any, of flow rate, dust concentration, temperature,
and dust type. Two levels of each of these parameters were used, which
meant 2 = 16 tests. Tables 5a and 5b give the levels of the parameters
for both dusts and the number designating the test at each particular
set of parameters. The data from these tests are in Appendix B. In
Tables 5a and 5b the balanced factorial design test matrix is enclosed
in a heavier line box. The design allowed testing whether or not each
of the parameters was significant and whether or not interactions of
two parameters were significant, using standard analysis of variance,
and allowed estimates of the experimental error of measurement. The
other tests done with iron oxide were made to investigate the efficiency
of a single stage, the effect of a lower spray nozzle pressure, the
effect of the addition at the inlet of water vapor, and the effect of
addition of surfactant to the spray. Three measurements were made at
one set of conditions to provide a second estimate of experimental
variation. In all, 25 tests have been reported. The results of an-
other seven were not'reported because of various failures during the
experiments, listed in Appendix B.
Statistical Analysis of Data
The data analysis was designed through a cooperative effort with GCA,
University of Dayton Research Institute, and the Control Systems Labora-
tory at EPA. The computer program used to analyze the data was the
BMD02V program from the Biomedical series, 1966 revision.
30
-------
99
98
99
90
Z.
Ul.
8-
5 60
O
C 90
u.
kl
z40
O
P 30
U
Ul
j 20
s
10
TEST NO '
2lx-HEAVY GRAIN LOADING, AMBIENT TEMPERATURE
22. O-HEAVY GRAIN LOADING, ELEVATED TEMPERATURE
9 A - LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
10 V-LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
o
9
i I § r i I * I I I 11 i
5l I I I i I 3 I 5 I 01 10
.54 .4 U t& 44) 84 8.« 19.7
AERODYNAMIC DIAMETER,
Figure 10. Inlet size distribution, fly ash at 0.47 m /s (1000 cfm)
31
-------
u
N
W
O
bl
OT
UJ
DC
O
bl
O
SBffi T
1 A-LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
14 y-LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
99.9
99
98
95
90
80
70
60
00
40
30
20
10
5
2
1
0.5
0.2
0.
0.0
-
-
X
A
t
A-
i
V
A
v I
A '
X
: v . x
A A
ii | ' I ' 1 i 4 t t jt ^
1 0.5 1.0 1 2 1 3 | 5 8| 10
O.54 0& 1.3 2.5. 4.0 5.6 d6 1
3.T
AERODYNAMIC OIAMETCR, /» m
^
Figure 11. Outlet size distribution, Iron oxide aerosol at 0.47 m /a
(1000 cfm)
32
-------
TEST NO.
9 X-LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
10 © -LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
. 21 A-HEAVY GRAIN LOADING, AMBIENT TEMPERATURE
22 V-HEAVY. GRAIN LOADING, ELEVATED TEMPERATURE
Ul
N
0
UJ
%
Z
£E
gj
UJ
cc
H
UJ
OC
UJ
Q.
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.2
O.I
0.01
-
.
* - m
.»-
»
- V
- ' -. .«'
^
' . -
; ;
'
-
X
x .
x
« <
.
1 II 1 1 1 1 1 1 III
0.5 1 1.0 2 | 3 | 5 | 8| 10
a 54 0.8 1.3 2.5. 4.0 5.6 86 12
AERODYNAMIC DIAMETER, /tro
Figure 12. Outlet size distribution, fly ash at 0.47 m /s (1000 cfm)
33
-------
Table 5a. TEST MATRIX, FLY ASH AEROSOL
500 cfm
(0.23 m3/s)
~ 1 gr/ft3
o
(~ 1 g/m )
Heateda
Ambient
#7
#8
~ 0.1 gr/ft3
(~ 0.1 g/m3)
#27
#26-
1000 cfm
(0.47 m3/s)
~ 1 gr/ft3
(~ 1 g/m3)
#22
#21
~ 0.1 gr/ft3
(~ 0.1 g/m3)
#10
#9
ainlet air T - 95°C = 200°F.
blnlet air T * 21°C « 70°P.
Table 5b. TEST MATRIX, IRON OXIDE AEROSOL
Heated*
Ambient
First stage
Steam added
Surfactant
Low spray pressure
500 c£«
(0.23 m3/s)
~ 1 gr/ft3
(~ 1 g/n3)
v5
#4
#28, 31
~ 0.1 gr/ft3
(~ 0.1 g/m3)
#24
#23
1000 cfm
(0.47 m3/s)
~ 1 gr/ft3
(~ 1 g/tn3)
<-'19
#16,17,18
#25
~ 0.1 gr/ft3
(~ 0.1 g/m3
#14
#12
#32
#13
)
1500 cfm
(0.71 B3/s)
,
~ 1 gr/ft3
(~ 1 g/n3)
#30
#29
*Inlet air T - 95°C - 200°F
blnlet atr T - 21°C - 70°F
34
-------
The following were treated as independent variables for this analysis:
total concentration (total filter), total impactor sample, impactor
samples on each of stages 5, 6, 7, 8, and impactor final filter.
The efficiencies of each of these seven aerosol size fractions were
put through an analysis of variance, using the standard F-test.
The computer program calculated the following for each of the size
fractions used:
"grand mean" of all 16 tests
"marginal means" of sets of eight tests having one
or the other of the treatment parameters: dust types,
flow rates, inlet concentrations, temperatures
"sum of squares" due to each of the four treatment
parameters as well as those due to two-factor and
three-factor interactions between the parameters.
A decision had to be made whether to test for the four three-factor
interactions and have only one estimate of the experimental error (the
residual sum of squares) or to limit the tests to one- and two-factor
analysis and have five estimates of the experimental error (the
residual sum of squares and the four three-factor sums of squares).
The latter choice was made, increasing the sensitivity of the tests
for the one- and two-factor contributions. This meant that the appro-
priate F-test to use was an F-test distribution having one degree of
freedom in the numerator and five in the denominator, F(l,5).
The results of the factorial test are summarized in Table 6. The mean
efficiencies for the tests and the corresponding uncertainties are
listed with the aerosol fraction to which they correspond. The aero-
sol fractions are: (1) the size intervals between impactor cutoffs,
(2) the total filter, (3) the sum of the material collected on the
impactor; the last has somewhat smaller mean sizes than the total fil-
ter due to losses of the very largest particles in the drying sections.
35
-------
The efficiencies for the two different dusts for the total filter and
the total impactor have been presented separately because these would
be expected to have very different median aerodynamic diameters, as
seen from the size distributions shown in Figures 9 and 10. The un-
certainty figures are derived from the uncertainty estimates for a
single test, which will be explained below,
Table 6. SUMMARY OF RESULTS OF 16 COLLECTION
EFFICIENCY TESTS FOR DYNACTOR
(FACTORIAL TEST DESIGN)
Aerosol fraction
Total filter
Iron oxide
Fly ash
Total impactor
Iron oxide
Fly ash
2.5 - 4.0 um
1.3 - 2.5 um
0.8 - 1.3 um
0.54 - 0.8 um
< 0.54 uta
Mean
efficiency
96.04 %
93.11
98.97
93.71
89.81
97.60
98.37
93.00
75.4
27.4
47.4
Number
of
tests, n
16
8
8
16
8
8
16
16
16
16
16
Estimated
uncertainty3
±0.32 %,
0.46
0.46
0.32
0.45
0.45
0.12
0.21
2.1
6. ft
3.7
From analysis of variance. See Table 10.
36
-------
Tables 7a through 7g present a much more detailed picture of the results
of the efficiency tests. Here are listed:
The aerosol fraction
The mean of all the efficiency tests in the factorial design
The means of the eight tests each at two different levels
of flow, temperature, and concentration, and two different
dusts
The results of the standard F-test analysis of variance*
for an F ratio having a numerator of 1 degrees of freedom
and a denominator of 5 degree of freedom
The mean square error associated with one measurement at
this size fraction.
The analysis of variance allows one to determine what likelihood there
is that the differences noted between measurements come from differences
in the parameters under study rather than from extraneous variations.
The "significance level" is the probability that one would be correct in
ascribing a difference in the results to a difference in the level of
the parameter under test, here flow, dust, temperature, concentration,
making the usual statistical assumptions about normal populations.
Table 8 lists the significance levels for the effects of these parameters
on efficiencies of collection for the various aerosol fractions.
The information in the Tables 7a through 7g, Table 8, and in Figures 13
and 14 allow us to draw the following conclusions:
1. The lower flow rate yielded higher efficiencies for
all size fractions and the differences were usually
statistically significant.
2, Fly ash was collected; with greater efficiency than
iron oxide for all size fractions, and these dif-
ferences were usually statistically significant.
3. The lower temperature produced greater efficiencies-than
did the higher temperature in seven of eight aerosol
fractions, but this was statistically significant in
only two fractions.
4. Higher concentrations were collected with greater effi-
ciency than lower concentrations and this was statis-
tically significant in most fractions.
37
-------
Table 7a. RESULTS OF STATISTICAL ANALYSIS ON. EFFICIENCY
PARTICLE SIZE FRACTION: Total Filter
GRAND MEAN OF EFFICIENCY TESTS: 96.04
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
-0.2 g/m3 (0.1 gr/ft3)
-2.0 g/m3 (1.0 gr/ft3)
MEAN
96.69
95.40
93.11
98.97
96.50
95.59
94.87
97.21
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(D(4)
F (1,5)
3.95
81.99
1.99
13.04
11.93
1.98
SIGNIFICANCE LEVEL
(IF > 0.90)
> .99
> .95
> .95
*
MEAN SQUARE ERROR: 1.677 .
38
-------
Table 7b. RESULTS OF STATISTICAL ANALYSIS ON- EFFICIENCY
PARTICLE SIZE FRACTION: Total Impactor
GRAND MEAN OF EFFICIENCY TESTS: 93.71
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
~ 0.2 g/m3 (0.1 gr/ft3)
~ 2.0 g/m3 (1.0 gr/ft3)
MEAN
94.05
93.36
89.81
97.60
94.40
93.01
91.62
95.79
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow .
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(DO)
I
F (1,5)
1.19
152.6
4.83
43.50
24.33
6.33
SIGNIFICANCE LEVEL
(IF > 0.90)
> .99
> .90
> .99
> .99
> .90
MEAN SQUARE ERROR: 1.593
39
-------
Table 7c. RESULTS OF STATISTICAL ANALYSIS ON.EFFICIENCY
PARTICLE SIZE FRACTION: Itnpactor Stage #5 , 2.5 - 4.0
GRAND MEAN OF EFFICIENCY TESTS: 98.37
MARGINAL MEANS
PARAMETER
LEVEL
MEAN
FLOW
14.2 mS/mitx (500 cfm)
28.3 m3/min (1000 cfm)
98.75
97.99
DUST
IRON OXIDE
FLY ASH
97.47
99.26
TEMPERATURE
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
98.57.
98.16
CONCENTRATION
-0.2 g/mj (0.1 gr/ft3)
~2.0 g/m3 (1.0 gr/ft3)
98.00
98.74
RESULTS OF F -TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(3) (4)
(2) (3)
F (1,5)
10.50
57.83
3.08
9.86
20.45
3.43
2.11
SIGNIFICANCE LEVEL
(IF > 0,90)
> .95
> .99
-
> .95
> .99
-
«
MEAN SQUARE ERROR: 0.221
40
-------
Table 7d.
RESULTS OF STATISTICAL ANALYSIS ON. EFFICIENCY
PARTICLE SIZE FRACTION: Impactor stage #6, 1.3 - 2.5 um
GRAND MEAN OF EFFICIENCY TESTS: 93.00
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 'm3 /rain (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
~ 0.2 g/m3 (0.1 gr/ft3)
-2.0 .g/m3 (1.0 gr/ft3)
MEAN
94.82
91.17
92.37
93.62
93.54'
92.46
92.59
93.41
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust '
(3) Temperature
(4) Concentration
(2) (4)
(D(4)
(DO)
mm
F (1,5)
75.80
8.89
6.57
3.86
40.71
25.69
11.55
8.19
SIGNIFICANCE LEVEL
(IF > 0.90)
> .99
> .95
> .95
-
> .99
> .99
> .95
> .9S
MEAN SQUARE ERROR: 0.703
41
-------
Table 7e. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Impactor stage #7, 0.8 - 1.3 nm
GRAND MEAN OF EFFICIENCY TESTS: 75.44
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 nP/min (1000 cfm)
IRON OXIDE .
FLY ASH
~ 20°C (~ 70°F)
- 95°C (~ 200°F)
~0.2 g/m3 (0.1 gr/ft3)
~2.0 g/m3 (1.0 gr/ft3)
MEAN
83.45
67.44
81.87
69.01
78.95-
71.94
72.79
78.10
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT F (1,5)
(1) Flow 3.79
(2) Dusf 2.45
(3) Temperature 0.73
(4*) Concentration 0.42
<1><2> 2.45
(DO) 1.63
SIGNIFICANCE LEVEL
(IF > 0.90) .
w
<
MEAN SQUARE ERROR: 270.6
42
-------
Table 7f. RESULTS OF STATISTICAL ANALYSIS ON- EFFICIENCY
PARTICLE SIZE FRACTION: Impactor stage #8 , 0.54 - 0.8 um
GRAND MEAN OF EFFICIENCY TESTS: 27.39
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
-0.2 g/m3 (0.1 gr/ft3)
~ 2.0 g/m3 (1.0 gr/ft3)
MEAN
26.66
28.12
16.92
37.86
25.04
29.75
26.51
28.27
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(DO)
F (1,5)
0.01
2.50
.13
, .02
2.22
SIGNIFICANCE LEVEL
(IF > 0.90)
-
MEAN SQUARE ERROR: 700.9
43
-------
Table 7g. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Final filter after impactor, < 0.54 um
GRAND MEAN OF EFFICIENCY TESTS: 47.38
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
~0.2 g/m3 (0.1 gr/ft3)
~2.0 g/m3 (1.0 gr/ft3)
MEAN
49.26
45.50
39.94
54.82
51.36
43.40
23.51
71.25
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(D(4)
(DO)
F (1,5)
0.26
4.05
1.16
41.62
7.04
4.60
1.83
SIGNIFICANCE LEVEL
(IF > 0.90)
.90
> .99
> .91
> .90
MEAN SQUARE ERROR: 219.0
-------
Table 8. SIGNIFICANCE OF EFFECTS OF FLOW, DUST, TEMPERATURE,
AND CONCENTRATION ON SCRUBBER COLLECTION EFFICIENCY
Aerosol fraction
Total filter
Total Impact or
2.5 - 4.0 ion
1.3 - 2.5 urn
0.8 - 1.3 ion
0.54 - 0.8 \m
< 0.54 \m
Significance level
Flow
~ 0.90
~
> 0.95
> 0.99
~ 0.90
Dust
> 0.99
> 0.99
> 0.99
> 0.95
--
~ 0.90
Temp.
> 0.99
> 0.95
*
*
M
Cone.
> 0.95
> 0.99
> 0.95
-0.90
..
> 0.99
45
-------
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99
1-
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DIAMETER, p m
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DIAMETER 'i
Figure 13. Dynactor scrubber collection efficiency versus particle
aerodynamic diameter, effects of loading and dust type
46
-------
99.5
99
98
Z
Ul
o
Ul
a.
>" 95
O ""
1
o
u.
u,
Z 90
O
H
u
Ul
o
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rt 1000 cfm
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i
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p
o:
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Ul
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IOO
1294
DIAMETER./tm
2 345
DIAMETER ,/i m
Figure 14. Dynactor scrubber collection efficiency versus particle
aerodynamic diameter, effects of flow rate and inlet
temperature
47
-------
The F-test analysis of variance also gave information on the signified
of interactions between the variables flow (1), dust (2), temperature
(3) and concentration (4). Thus the interaction labeled (2) (4) in
the Tables 7a, b, c, d, g, is the interaction of dust and concentra-
tion, which can be interpreted in either of two ways: the degree to
which different dusts gave a different dependence of efficiency upon
concentration or the degree to which different concentrations gave a
different dependence of efficiency upon dust type. In Table 9 are
arrayed the averages of four tests each at the particular combinations
of parameters whose interaction was found to be significant for the
1.3 to 2.5 urn aerosol fraction, Table 7d. Thus, the first group con-
tains two levels of concentration and two types of dust, from which
we see that the difference in efficiency between high and low concen-
trations was more pronounced for iron oxide than it was for flyash.
The next set in Table 9 shows that the difference in efficiency between
the two types of dust was greater at the lower flow rate than at the
higher. Similar interpretations would be appropriate for the other twc
sets of data in Table 9: the effect of temperature was greater at the
higher flow rate and the effect of concentration was greater at the
lower flow rate. The F-test values in Table 7d indicate all these
statements are statistically significant. The flow interactions are
displayed in Figure 15. The explanations of all these interactions
for all the stages would be difficult to make; an example of one such
explanation would be that the difference in efficiency for the two
dusts is caused by collection mechanisms, such as diffusion or elec-
trostatics, that increase with increased residence time, thus produc-
ing a greater difference between dusts at the lower flow rate.
Estimates of Experimental Error
Two methods were used to get estimates of the experimental error. The
first involved dividing the residual sum of squares by the number of
degrees of freedom (5) and taking the square root, for .the data in the
4 ' '.'-...- .
balanced 2 test matrix used in the analysis of variance. This is a
48
-------
Table 9. DETAILED ANALYSIS OF INTERACTIONS FOR DYNACTOR
EFFICIENCY ON 1.3 - 2.5 lira AEROSOL FRACTION
(STAGE #6)
Efficiencies (N=4)
Concentration (4)
3
~ 0.1 g/m
o
~ 1.0 g/m
Dust (2)
Iron oxide
Fly ash
Temperature (3)
20°C
95°C
Concentration (4)
' 3
~ 0.1 g/m
o
~ 1.0 g/m
Parameter: Dust (2)
Iron oxide
90.6
94.2
Fly ash
94.6
92.7
Parameter: Flow (1)
500 cfm
93.6
96.0
94.6
95.0
93.4
96.3
1000 cfm
91.2
91.2
92.4
89.9
91.8
90.6
49
-------
100
98
O Iron oxide
O Fly ash
96
P4
g
§ 94
1
90 -
J_
_L
A 20°C
95°C
QO.l g/a3
01. g/a3
CFM
/ndn
500
14.2
0.24
1000
28.3
0.47
500
14.2
O.24
1000
28.3
0.47
500
14.2
0.24
1000
28.3
0.47
Figure 15. Collection efficiency, 1.3-2.5 JOT, versus flow for
different dusts, temperatures, and concentrations
-------
standard method. The residuals were those from the analysis- of the
individual factors (flow* dust, temperature, and concentration) and
two-factor interactions. Such residuals would include three-factor
interactions, if any, and mistakenly treat them as experimental error.
(Nearly always, these three-factor contributions to the sum of squares
were of the same magnitude as the residuals left even after the three-
factor interactions were taken into account.) The second estimate of
the experimental error came from the three replications for iron oxide
3 33
at 1000 cfm (0.47 m /s), ~ 1 gr/ft (~ 1 g/m ), at ambient temperature.
Both are given in Table 10." In five of seven cases, the estimates from
the replication tests were lower. The standard deviation of an average
of N such tests would be the standard deviation for one test divided
1/2
by N . For any one of the measurements to be significantly different
from a given value, it should be at least two standard deviations dif-
ferent from that value, which.gives a guideline for comparing the
results of the tests done outside the factorial design test matrix.
Collection Efficiency Tests at 1500 cfm (0.71 m3/s)
An 8-point pitot tube traverse was used downstream in 8-inch (0.20 m)
. 3-
diameter duct and yielded an outlet flow of 1510 cfm (0.71 m /s). A
20-point pitot tube traverse used upstream in 12-Inch (0.30 m)
diameter duct yielde4 an inlet flow of 1250 cfm (0.59 m /s). Magne-
helic gauges used for the above traverses were checked with an upright
manometer, they were in good agreement which determined that the
gauges were not the cause of the above flow discrepancy.
An attempt was made to seal leaks inthe Dynactor and peripheral ducting,
but it must be assumed that with a static pressure loss greater than
2.01* IU> (5.0 art WC) at the outlet some leakage occurred. Flow
through the Dynactor was calculated as the average between inlet and
outlet volumes, but grain loading was calculated on"the basis of the
flows measured upstream and downstream. Efficiency was determined by the
51
-------
ratio of the rate of particulate mass flow out of the Dynactor to the
rate of particulate mass flow into the Dynactor.
Table 10. ESTIMATES OF EXPERIMENTAL ERROR FOR SINGLE TEST
FROM THE RESIDUALS OF THE SUM OF SQUARES AND
FROM THE REPLICATION TESTS, Nos. 16, 17, 18
Aerosol fraction
Total filter
Total impact or
2.5 - 5.6 urn
1.3 - 2.5 urn
0.8 - 1.3 urn
0.54 - 0.8 urn
< 0.54 urn
Standard deviation estimates
l/2a
(M.S.E.)1'
00
1.29
1.26
0.47
0.84
8.4 (17.7)C
26.5
14.8
0.59 x range
(%)
0.41
1.00
0.59
0.12
3.7
34.0
11.2
Root mean square of residual sum of squares after two-
factor analysis of factorial design tests.
Best estimate of standard deviation from range of three
measurements. **
«
Value including a discarded datum, test No. 10 (12.5).
The results for the tests at 1500 cfm (0.71 m /s) and at 1000 cfm
3 3
(0.47 m /s) for iron oxide at 1 mg/m are given in Table 11 to facilitate
comparison. At ambient temperature, the lower flow rate produced a
higher efficiency in six of the eight aerosol fractions measured and
indistinguishable efficiencies in one,, diameters < 0.54 urn. In
three cases (total impactor, 2..5 to 4.0 urn, 1.3 to 2.5 urn) the
higher flow rate value was more than two of its estimated standard
deviations away from the low flow rate mean, which would support the
conclusion that at ambient temperature the effect-of increasing the
flow lowered the efficiency. At the elevated temperature, 95°C (200°F),
52
-------
raising the flow seems not to have decreased the efficiency. Three
efficiencies were lower and three were higher. The data from the
3 '3
tests at 1000 cfm (0.47 m /s) and 1500 cfm (0.71 m/s) displayed lower
efficiencies for increased flow at 20°C but not at 95°C; at 1000 cfm
(0.47 m /s), six of six fractions showed higher efficiencies at 21°C
rt ' ^
than at 95 C, but at 1500 cfm (0.71 m /s) six of seven fractions showed
higher efficiencies at 95°C than at 21°C, suggesting an interaction
between the two variables.
Table 11. RESULTS OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
S BIHAR CONDITIONS EXCEPT FOR FLOW RATE (IRON OXIDE,
- 1 g/m3)
Aerosol fraction
Total filter
Total impact or
2.5 - 4.0 \m
1.3 - 2.5 \m
0.8 - 1.3 \m
0.54 - 0.8 \m
< 0.54 pm
Test number
21°C (70°F) 95°C (200°F)
1500 cfm
(0.71 m3/s)
94.8
88.9
97.0
87.1
75.0
< 19.4
--
29
1000 cfm
(0.47 m3/s)
95.4
93.9
98.5
93.1
83.7
46.4
< 82.5
16,17,18 avg.
1500 cfm
(0.71 m3/s)
94.7
93.8
98.6
89.4
83.1
75.8
«
30
1000 cfm
(0.47 m3/s)
94.9
91.7
97.6
89.9
75.9
'
66.1
19
Collection Efficiency Tests With Inlet Air Humidified
Efficiency tests vere performed using heated air to evaporate a fine
water spray upstream from the Dynactor inlet to use the subsequent con-
densation of water vapor to enhance particle collection (diffusiophoresis)
The spray was introduced downstream from the inlet sampling probes. Two
*
# 1511 Sprayco pinjet nozzles operated at 80 psi (5.3 x 10 era WC) were
used, spraying 0.56 gal/min (3.5 x 10 m /s) into air at 350°F <117°C).
53
-------
The humidity ratio was determined two ways: by weight change of desiccant
material, after the gas passed through a cyclone (10 mm) and by wet bulb/
dry bulb thermometer measurements (and comparison with a psychometric
chart). During test #28, the wet and dry bulb thermometers were
inserted into the duct immediately upstream from the Dynactor inlet.
During test #31 the gas sample was made to pass not only through a
cyclone but also through a heating section into which the wet bulb and
dry bulb thermometers were placed, and from which it passed into the
desiccant. The ratio, by weight, of water vapor to dry air for test
#28 was 0.032 as determined by desiccant weight gain and 0.057 as
determined by the thermometric measurements. Some of this discrepancy was
thought to be due to condensation in the sampling line to the desiccant,
one of the reasons the heated section was introduced for test #31. For
test #31, the humidity ratio was 0.070 as determined by the desiccant
and 0.071 and 0.086 as determined by thermometric measurements near the
beginning and end of the test. No intentional changes were made in the
system in producing the high humidity ratio the second time, so the
different average humidity ratios (0.044, 0.076) are rather puzzling.
The data from these two tests are given in Table 12, along with data
from two tests most nearly matching the conditions of the steam addition
tests. In each aerosol size fraction the ranges of the steam added
tests and the tests without added steam overlap, with the exception of
the diameter interval 1.3 to 2.5 ym, for which the efficiencies with-
out steam addition are higher than those with added steam. The addi-
tion of water vapor to achieve an inlet humidity ratio of about 0.05
g water per g dry air did not appreciably enhance collection efficiency
an unexpected result.
54
-------
Table 12. RESULTS: OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
SIMILAR CONDITIONS BUT WITH AND WITHOUT STEAM ADDITION
(IRON OXIDE, 500 cfm = 0.24 m3/s, LOADING ~ 1 g/m3)
Aerosol fraction
Total filter
Total impactor
2.5 - 5.6 urn
1.3 - 2.5 urn
0.8 - 1.3 urn
0.54 - 0.8 urn
< 0.54 pm
Tests
No steam
#4
96.4
93.9
98.3
96.0
85.2
--
73.3
#5a
91.1
94.3
99.1
97.5
89.3
_-
72.0
Avg.
93.8
94.1
98.7
96.8
87.2
--
72.6
Steam added
#28
--
95.4
99.3
95.0
85.7
48.4
< 64.4
#31
96.2
93.0
98.9
94.0
80.3
70.0
< 80.0
Avg.
96.2
94.2
99.1
94.5
83.0
59.2
< 72.2
3This test done at 95°C (= 200°F).
Collection. Efficiency Test With Surfactant Added to the Spray
The addition of a surfactant chemical to the spray used in the Dynactor
might be expected to affect efficiency by changing the droplet size
distribution in the spray somewhat and changing the wetting efficacy
of the droplets, both changes due to the lowering of the surface tension
of the water in the spray. A surfactant was added to the water
reservoir in the Dynactor's stages to form a 10 parts per million
solution. An efficiency test (test #15) was run using this solution,
but otherwise at the conditions at which the replicative tests
3 3
(#17, 18, 16) were run; that is, 1000 cfm (0.47 m /s), ~ 1 gr/ft
o
(~ 1 g/m ), iron oxide aerosol, ambient temperature. Table 13 contains
the efficiencies from the two types of test. In six of six aerosol
fractions, the surfactant additive gave a higher efficiency than had
been obtained without it, and in the other fraction there was no dis-
tinguishable difference. In the range 1.3 to 4.0'vm, the efficiencies
were more than one standard deviation apart but less than two.
55
-------
Table 13. RESULTS OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
SIMILAR CONDITIONS EXCEPT FOR TILE ADDITION OF 10 ppm
SURFACTANT TO THE SPRAY WATER
Aerosol fraction
Total filter
Total impactor
2.5 - 4.0 urn
1.3 - 2.5 urn
0.8 - 1.3 |j.m
0.54 - 0.8 urn
< 0.54 urn
Test number
Collection efficiencies
Surfactant
added
95.5
94.4
99.2
94.2
84.9
62.2
< 82.2
25
No
surfactant
95.4
93.9
98.5
93.1
83.7
46.4
< 82.2
16,17,18 avg.
Collection Efficiency Tests At Reduced Nozzle Pressure
One efficiency test was made using the Dynactor spray nozzles at 100 paie
2
(7.04 x 10 cm WC), half their normal pressure. This test, #13 listed
in Appendix B, is directly comparable with test #12, also listed in
Appendix B, and in every size fraction it gave a lower efficiency. The
3 3
total efficiency on iron oxide at 1000 cfm (0.47 m /s) at ~ 0.1 g/m
3
(~ 0.1 gr/ft ) at ambient temperature was 81.8 percent for this
reduced pressure, compared with 90.0 percent at the usual nozzle
pressure for these same conditions.
Some of these results are discussed more fully in the next section,
which also contains a comparison between the Dynactor scrubber and con-
ventional venturi scrubber technology.
56
-------
SECTION VI
DISCUSSION
In this section, we compare the Dynactor Scrubber with other scrubbers
with respect to power consumption. The effects of the factors studied
with the factorial design tests are discussed as well.
DYNACTOR SCRUBBER POWER CONSUMPTION COMPARISON
The prime function of the Dynactor scrubber is the same as that of the
venturi scrubber, to remove particulate material, so the comparison
between the two devices should be made for conditions under which they
have the same, or nearly the same, efficiency. Both devices use water
sprays to remove particulates. Both consume clean water. Both use power
to produce a velocity difference between the sprays and the gas to be
cleaned. Both would be expected to have similar waste disposal and
maintenance costs.
The number used to specify efficiency is the "aerodynamic cut diameter,"
the particle aerodynamic diameter for which the device has a collection
efficiency of 50 percent. (Note that this assumes the collection effi-
ciency versus particle aerodynamic diameter is single-valued at 50
percent efficiency.) The cut diameter has long been used regarding im-
pactors. The particle aerodynamic diameter is the diameter of a sphere
with unit density (1 gin/cm ) which would have the same terminal gravi-
tational settling velocity in air as the particle. In the particle
size range above a few tenths microns, impaction is the predominant
scrubbing mechanism generally, so that in this particle size domain
57
-------
3
the use of the aerodynamic cut diameter is reasonable. Calvert re-
K
cently discussed its application vis a vis scrubber .efficiencies.
The analysis proceeds as follows:
1. A curve for efficiency versus particle size is graphed
from experimental data.
2. The particle aerodynamic diameter corresponding to 50
percent efficiency is determined from that curve; this
is the aerodynamic cut diameter.
3. From the experimental conditions, the intrinsic power
consumption is determined (flow times pressure drop
for the motive fluid) and put in the form of power
per volume flow of gas (=pressure), such as .hp/1000
cfm or inches tUO or cm H«0 (=cm WC).
4. The aerodynamic cut diameter is plotted against pres-
sure drop or power per unit volume flow of gas on a
graph (after Calvert)^ having predicted values for a
venturi scrubber and other types of scrubbers.
5. From this plot one can determine whether more or less
power is used by the scrubber in question than is pre-
dicted for other scrubbers at the same aerodynamic cut
diameters.
Figures 16 to 20 present collection efficiency versus particle aerodynamic
diameter for the two aerosols at the three flow rates. The efficiencies
for the two smallest size intervals (points plotted at 0.27 um and
0.67 um) were determined as they had been for the statistical tests. The
other efficiencies were obtained as follows: The impactor substrates
had shown a weight loss generally 0.3 mg or less and the weighing un-
certainty was about 0.1 mg, so that a best case efficiency value for any
particle size fraction in any run was obtained by adding 0.4 mg to the
net weights on the inlet impactor stages and subtracting 0.1 mg from the
net weights on the outlet stages. The new weights were used to obtain
concentrations, thus efficiencies. A worst case efficiency was obtained
by reversing the treatments of the inlet and outlet'impactor stages.
(This would have been done for the two smallest size fractions but for
58
-------
99.9
99.8 -
L.S. F.
/ (LEAST
Z SQUARES
I FIT>
1234
AERODYNAMIC DIAMETER, /tin
100
Figure 16. Dynactor collection efficiency versus aerodynamic diameter,
average of data for iron oxide at 0.23 m3/s (500 cfm)
59
-------
99.9
99.8
99.5
£ 98
z
LU
U
u.
15 95
90
80
50
T 1 r^ 1 T
L.S.F
i i i i I L
2 34
AERODYNAMIC DIAMETER, ^m
O.I
0.2
0.5
1.0
ft:
I-
UJ
5.0
10
20
50
100
Figure 17,
Dynactor collection efficiency versus aerodynamic diameter,
averages of data for fly ash at 0.23 m3/s (500 cfm)
60
-------
99.9
99.8 -
0
Figure 18.
100
1234
AERODYNAMIC DIAMETER, /i m
Dynactor collection efficiency versus aerodynamic diameter,
averages of data for iron oxide at 0.47 m-Vs (1000 cfm)
61
-------
99.9
99.8
99.5
99
98
z
u
o
u.
95
90
80
50
i t i i i t I 1 L
O.I
0.2
0.5
1.0
a:
I-
UJ
5.0 2
10
20
1234
AERODYNAMIC DIAMETER, /* m
50
100
Figure 19. Dynactor collection efficiency versus aerodynamic diameter,
averages of data for fly ash at 0.47 m^/s (1000 cfm)
62
-------
99.9
99.8
100
12 3 4
AERODYNAMIC DIAMETER , /* m
Figure 20. Dynactor collection efficiency versus aerodynamic diatneterj
averages of data for iron oxide at 0.71 tn3/s (1500 cfm)
63
-------
the frequent occurence of infinite efficiencies resulting from the com-
bination of a 0.0 mg/m inlet concentration and a nonzero outlet
concentration.)
In Table 14 have been listed the averages of the best and worst case
analyses along with the averages of the efficiencies calculated from the
original data for the three size fractions in which this best/worse case
average approach was used. The differences between the raw data and the
average of the best and worst case averages are generally negligible.
In Figures 16 to 20 the x's are the points from which the least squares
fit was made, the average raw data values for stages 5, 6, 7 and the
values used in the statistical tests for the smallest two size intervals.
The bands shown are the averages of the best and the worst cases. (This
data treatment emerged from a discussion with Control Systems Laboratory
personnel.)
From the least squares fit line (L.S.F.) can be determined the aero-
dynamic cut diameter for the iron oxide and fly ash tests at the flow
rates 0.23 m3/s (500 cfm), 0.47 m3/s (1000 cfm) and for the iron oxide at
o
0.71 m /s (1500 cfra). The spray volume flow rate and the pressure at
the nozzles was constant for these three air flow rates, so the power
was constant. The three air flow rates meant three values of power per
air volume flow rate.
Figure 21 is adapted from one presented by Calvert. It has aerodynamic
cut diameter graphed against power per unit flow rate (hp/acfm). Also
shown is the equivalent air pressure drop if all the power went to
moving the volume of air through a flow resistance. The five average
particle aerodynamic cut diameters have been drawn on this figure to
allow comparisons with other scrubbers.
The Dynactor scrubber data points are scattered about the lower of the
two lines (2b) in Figure 21, indicating that its power consumption is not
64
-------
Table 14. BEST CASE AND WORST CASE AVERAGE EFFICIENCIES FOR DYNACTOR SCRUBBER
TESTS FOR FLY ASH AND IRON OXIDE AT THREE FLOW RATES
Ul
Test
numbers
4,5,23,24
7,8,26,27
12, 14,
(16,17,18),
19
4,10,21,22
29,30
Flew rate
0.23 m3/s
(500 cfm)
0.23 m3/s
(500 cfm)
0.47 m3/s
(1000 cfm)
0.47 m3/s
(1000 cfm)
0.71 m /s
(1500 cfm)
Aerosol
Iron
oxide
Fly ash
Iron
oxide
Fly ash
Iron
oxide
Impactor
stage
5
6
7
5
6
7
5
6
7
5
6
7
5
6
7
Best case
average
98.1
93.8
84.6
99.8
96.5
87.5
97.6
91.7
81.9
99.1
92.3
71.4
98.4
89.4
81.4
Worst case
average
97.4
93.2
82.5
99.3
95.5
80.5
96.0
90.5
79.1
98.3
90.1
41.2
96.6
86.8
76.9
Average
best/worst
97.8
93.5 '
83.6
99.6
96.0
84.0
96.8
91.1
80.5
98.7
91.2
56.3
97.5
88.1
79.1
Rav; data
average
97.9
93.6
83.3
99.6
96.0
83.4
97.1
91.2
80.3
98.9
91.2
68.6
97.8
88.2
79.0
-------
4.0
3.0
2.0
E
3.
o
ex
o
oT i.o
UI
2 0.8
0.6
0.5
0.4
I 0.3
ce
0.2
O.I
1.5
PRESSURE DROP, Inches H20
45 8 10 15 20
30 40
100
0.25
0.5
0.8 1,0 2.0 3.0
POWER,hp/IOOO ocfm
5.0
8.0 10
5 6 7 8 9 IO
20
30
50
70 90 100
200 300
PRESSURE DROP, cm H2O
Figure 21. Aerodynamic cut diameter versus pressure drop across scrubber or power per unit volume
flow, adapted from Calvert (1974). 3 Lines 2a and 2b are for venturi scrubbers.
Dynactor scrubber data averages are denoted by +'s
-------
substantially different from that of a well-designed venturi scrubber
having the same particle collection efficiency as the Dynactor.
EFFECTS OF FLOW, DUST, TEMPERATURE, CONCENTRATION, ETC.
As noted in the results, there were statistically significant effects
on collection efficiency due to flow, dust, temperature, and concentra-
tion of particulates. Here we will discuss these effects and link
these results with those of others.
Flow
Increasing the flow rate will increase the velocity gradients, which
would-be expected to increase deposition due to impaction and intercep-
tion and to increase the turbulent eddy diffusivity, which is a linear
function of the Reynolds number (Calvert et al.)> and thus
increase the rate of mass transfer to the droplets. Increasing the
flow rate will also decrease the residence time, which would give less
time for the collection mechanisms to act, significant for the smallest
particles, where diffusion would predominate the collection mechanisms,
and for the largest particles, for which settling would become import-
ant. We found somewhat higher collection efficiencies at the lower
flow rate, as did Lancaster and Strauss in their experiments
with spray scrubbers, using ZnO particles with a number median dia-
meter of 1.0 urn.
Dust
Particles of fly ash were consistently collected with greater efficiency
than particles of iron oxide having the same aerodynamic diameter in
our tests. Different aerodynamic behavior by particles having the same
aerodynamic diameter is unexpected, but perhaps the particles differed
in the likelihood with which a particle/droplet collision produced
67
-------
capture or in the degree to which they served as nuclei during condensa-
tion or the degree to which high humidities facilitated their agglomera-
tion. The iron oxide powder seemed less hydrophilic than did the fly
ash, because water droplets beaded up on iron oxide layer and absorbed
into a fly ash layer, thus the iron oxide may have been less wettable
and more difficult for the water droplets to entrap. Lohs found that
making hydrophobic polystyrene particles into hydrophilic ones, by coat-
ing their surfaces with a wetting agent, increased the capture of these
particles by a spray scrubber. From their experiments with venturi
scrubbers, Calvert, Lundgren, and Mehta concluded that particle
wettability enhanced collection efficiency.
Temperature
Temperature can influence collection efficiency in a variety of ways.
Higher temperatures means higher viscosity for gases; for example, as
air goes from 20 C to 100 C, its viscosity increases a factor of
2
1.20 (Bird et al.)> which increases its resistance to particle
motion, hindering the various collection mechanisms. For the sub-
micron particles, this can be offset by the increase in the Cunningham
slip correction factor as temperature increases and by the increase
in the particle diffusivity due to Brownian motion. Our experiments
showed a statistically significant decrease in collection efficiency
for 1.3-2.5 urn aerodynamic diameter particles as temperature increased
from 20°C to 95°C, as well as a general trend toward decreased effi-
o
ciencies for all the aerosol size fractions. Lancaster and Strauss
measured a decrease in efficiency in going from 20 C to 30 C with a
spray scrubber operating on water-saturated air containing particulate
material.
Concentration
As particle concentration increases, particle agglomeration increases
due to coagulation. Increased agglomeration means an aerosol having
68
-------
larger mean size, which generally enhances collection efficiency in
spray scrubbers. Increased concentrations yielded higher collection
efficiencies in all the aerosol size fractions in our tests. Lancaster
Q
and Strauss, among others, reported increased efficiency with
increased mass loading. In our tests with the Dynactor, the improvement
in collection was most dramatic for the smallest particles,
indicative of coagulation.
Surfactant Addition
The addition of wetting agent, surfactant, to the spray water lowers
the surface tension of the water, which would mean it improves the
ability of the droplets to wet and engulf particles and it tends to
decre'ase the droplet size of the spray, the latter being determined
by the equilibrium between the force of surface tension and the forces
tending to break up the droplets. Improved wetting should improve
collection efficiency in situations where poor wetting is an inhibitor,
which we believe was the situation with iron oxide. Smaller droplet
sizes generally improve collection efficiency as well, for a given
droplet mass concentration. Our results showed a trend toward a slight
improvement in efficiencies using a surfactant additive.
Water Vapor Addition, Diffusiophoresis, Thermophoresis
9
Lapple and Kamack" were among the first of many to note that the
addition of steam upstream from a scrubber could produce substantial
improvements in collection efficiencies. Lohs attributed the
enhancement of efficiency, which he too measured, to the following
causes: condensation on the particles which made them into relatively
massive droplets, improved adhesion between particles and particles
and between particles and spray droplets, diffusiophoresis. Sparks
12
and Pilat calculated the contribution of diffusiophoresis to
collection by spray droplets and concluded the effect could be dramatic,
69
-------
increasing for smaller particles and lower gas/droplet relative
velocities. On the other hand, Slinn and Hales analyzed the roles
played by therinophoresis and diffusiophoresis in the scavenging of
atmospheric aerosols by cloud droplets and concluded that therraophoresis
generally predominates.
If the condensation process begins with a drop which is at the ambient
temperature, then the condensation heats the drop and this heating
produces an opposing thermophoresis; if evaporation begins with the
drop at ambient temperature, these two mechanisms are reversed and
still oppose each other. Relatively hot droplets which evaporate will
repel particles due to both diffusiophoresis and thermophoresis until
they cool to below ambient temperatures; relatively cool droplets
which condense moisture will attract particles by both mechanisms
until they heat to above ambient temperatures. For droplets starting
at the ambient temperature (Too), condensation causes the droplet to
heat up due to the latent heat of condensation, X, and thermal forces
inhibit collection. An approximate ratio of the two flux forces was
given by SLinn and Hales ^ as:
.... MX
thermophoresis _ a
diffusiophoresis 5 R T
CO
where
M = "molecular weight" of air,
3
X = latent heat of evaporation/condensation
R = gas constant
Tm = temperature of the fluid medium
from which they computed that thermophoretic transport will exceed
diffusiophoretic transport by a factor of about 6 and oppose it.
o
Lancaster and Strauss tried to separate the effects -of these
flux force mechanisms from the effects of particle size increase and
70
-------
adhesion improvement due to water vapor. They used cold and hot sprays
to scrub water-saturated air and gound no improvement with the cold
spray, which would have produced greater condensation upon the spray
droplets and would have produced an enhancing thermophoresis.
Lancaster and Strauss did find that steam addition helped increase col-
lection efficiency, decreasing the particle penetration by a factor of
(1- 5Q), Q being the mass ratio of steam to air; this increase they
attributed to particle build-up due to condensation. A recent survey
of "flux force/condensation scrubbing," the use of steam with spray
scrubbers, concluded that particle growth probably predominates over
4
diffusiophoresis as the enhancement mechanism (Calvert et al.) for
multistage devices. The relative roles of these mechanisms seem as yet
in question, but they are important considerations in the design of
scrubbers: if the improvement in collection efficiency is due to
particle build-up, then steam should be added as early in the flow .
as practicable; if diffusiophoresis is enhancing collection and doing
so more vigorously than particle build-up, then the steam should be
added just shortly before the scrubbing takes place.
Recent experimental work by Semrau and Witham of Stanford Research
Institute demonstrated enhanced collection due to condensation for steam
to air ratios near 0.3. It was concluded that such collection by
condensation would not be a practical alternative to conventional high
energy scrubbing but can supplement it, especially where waste heat or
high water vapor contents are already available.
Although we did not find a major improvement in efficiency when we
used ~ 0.05 water vapor to air ratio, this ratio was about one-third
that ratio recommended in the study of "flux force scrubbing" by
Calvert et al., (1973).4
71
-------
SECTION VII
REFERENCES
1. Bird, A. N. Jr., J. D. McCain, and D. B. Harris. Particulate
Sizing Techniques for Control Device Evaluation. A.P.C.A.
Meeting. Chicago. Paper 73-282, 1973.
2. Bird, R. B., W. E. Stewart, and E. N. Lightfoot. Transport
Phenomena. Wiley, New York. 1960.
3. Ca'lvert, S. Engineering Design of Wet Scrubbers. J. Air
Pollution Control Assoc. 24:929-934.
4. Calvert, S., J. Goldschmid, D. Leith, and N. C. Jhaveri.
Feasibility of Flux Force/Condensation Scrubbing for Fine
Particulate Collection. Control Systems Laboratory, N.E.R.C.,
Research Triangle Park, North Carolina. EPA-650/2-73-036. 1973.
5. Calvert, S., J. Goldschmid, D. Leith, D. Mehta. Scrubber
Handbook. Control Systems Division, Office of Air Programs,
E.P.A. 1972.
6. Calvert, S., D. Lundgren, and D, S. Mehta. Venturi Scrubber
Performance. J. Air Pollut. Control Assn. 22:529-532. 1972.
7. Dixon, W. J. BMD: Biomedical Computer Programs. U, Calif.
Press, Berkeley. 1973.
8. Lancaster, B. W., and W. Strauss. A Study of Steam Injection
Into Wet Scrubbers. Indus. Engr. Chem. Fund. 10:362-369. 1971.
9. Lapple, C. E. and H. J. Kamack. Performance of Wet Dust
Scrubbers. Chem. Eng. Prog. 51:110. 1955.
10. Lohs, W. Manufacture of Aerosols and Separation of Ultrafine
Dusts in Spray Washers. Staub. 29:No. 2, 43. 1969.
11. Slinn, W. G. N. and J. M. Hales. A Re-evaluation of the Role of
Thermophoresis as a Mechanism of In - and Below - Cloud Scavenging
J. Atmos. Sci. 28:1465-1471. 1971.
72
-------
12. Sparks, L. E. and M. J. Pilat. Effect of Diffusiophoresis on
Particle Collection by Wet Scrubbers. Atmos. Environ. 4:651-660.
1970.
13. Wilson, E. B., Jr. An Introduction to Scientific Research.
McGraw-Hill, Inc., New York: 1952.
14. Semrau, K. and C. L. Witham. Wet Scrubber Liquid Utilization.
Control Systems Laboratory, N.E.R.C., Research Triangle Park,
North Carolina. EPA-650/2-74-108. 1974.
73
-------
SECTION IX
APPENDIXES
Page
A. Manufacturer's Description of Dynactor 75
B. Dynactor Efficiency Data 79
74
-------
APPENDIX A
MANUFACTURER'S DESCRIPTION OF DYNACTOR
The continuous gas/liquid contactor, the Dynactor, is a proprietary
development of R P Industries, Inc. Figure A-l is a cross section of
a single stage Dynactor diffusion contactor. Liquid entering the sys-
tem under a pressure of 140 to 200 pounds per square inch (typical)
is atomized into thin films and droplets of average thickness or dia-
meter less than 1/64 inch. This liquid discharge diffuses or expands
into the reaction chamber causing air or gas to be aspirated by being
trapped within the moving shower of films and particles. The result-
ing mixed fluid then continues to travel down the reaction column
with intimate contact maintained between gas and liquid. This causes
physical and chemical equilibria to occur by the time the mixed fluid
exits from the reaction column into the separation reservoir. The
Dynactor can be viewed as a macroscopic diffusion pump which makes
use of diffusion principles in order to aspirate large volumes of air
per volume of motive liquid. By utilizing diffusion rather than
Bernoulli principles, the Dynactor aspirates up to 4,800 standard
volumes of gas per volume of motive liquid. In comparison, venturi
eductors will aspirate not more than 100 volumes of gas per volume
of motive liquid.
Because there are no venturi or other constrictions in the Dynactor,
energy requirements are considerably lower than for conventional jet
or venturi eductor systems. If gas carries small solid particles
along with it, such as activated carbon or powdered neutralizing and
precipitating agents, such particles are wetted and captured by the
75
-------
LIQUID INPUT, 140 TO 200psi
AIR INPUT, LOW VELOCITY, AMBIENT PRESSURE
HIGH VELOCITY, SUB-AMBIENT PRESSURE
SHOWER OF THIN FILMS AND PARTICLES
REACTION COLUMN
TURBULENT
MIXED
FLUID
OUTPUT
BAFFLE
RESERVOIR/SEPARATOR
(LIQUID)
LIQUID LEVEL DETER-
MINING TRAP
_l
LIQUID OUTPUT
Figure A-l. Single-stage Dynactor diffusion system
cross sectional view
76
-------
liquid throughout the entire length of the reaction chamber. By con-
trast, venturi wet scrubbers make effective contact between gas and
liquid only in the constricted throat region. Contact time, therefore,
in the Dynactor is about 20 times longer than in venturi devices.
Just as in oil and mercury diffusion vacuum pumps, it is also possible
to construct Dynactors having multistage gas inputs. Figure A-2 is
a drawing of the two-stage Dynactor diffuser system employed in these
studies. The internal configuration was constructed to maximize gas/
liquid turbulence and contact throughout the length of the six-foot
long, 12-inch diameter reaction column.
77
-------
co
.DIRTY
GAS
IN
f
*
PLENUM
0
§
1-1 S
H S
w o
w 2:
o o
< H
H H
£?
w 2
t"^ S3
S3 O
M O
RESERVOIR
SEPARATOR
«./'
*«*
*
PLENUM
N
§
14 55
B|
3 o
GAS OUT
t
1
W
o
CO
.0
RESERVOIR
SEPARATOR
PUMP I
WATER OUT
Figure A-2
PUMP
Two-stage Dynactor
MAKE UP WATER IN
-------
APPENDIX B
DYNACTOR EFFICIENCY DATA
This appendix presents all the data on the Dynactor efficiency tests
used as a basis for the' Dynactor evaluation. It includes the tests for
4
the balanced 2 factorial design study, as well as tests involving
2
flow at 1500 cfm (0.71 m /s), moisture addition with a spray nozzle
upstream from the Dynactor, use of surfactant in the Dynactor spray,
and testing of a single stage of the two-stage device.
The efficiency data sheets, one for each individual set of test condi-
tions, contain the following information:
Test identification number
Concentration at Dynactor inlet
Concentration at Dynactor outlet
Total mass efficiency, based on the preceding two numbers
Aerosol material used in test
Air flow through Dynactor
Volume rate of flow of Dynactor spray
Temperature at Dynactor inlet
Remarks, where appropriate
Flow rate and sample duration for the various sampling devices
Fractional efficiency data, including:
Limits, aerodynamic diameter, of size interval
Concentration of aerosol in that size interval at Dynactor inlet
Concentration of aerosol in that size interval at Dynactor outlet
79
-------
Mass efficiency on particles of sizes in that size
interval, based on the preceding two numbers
0 Total concentrations measured by the Andersen
impactors at inlet and outlet and mass efficiency
based on them
As discussed in the report, the substrate material onto which im-
paction occurred sometimes showed a weight loss or a weight gain that
was less than 0.3 mg. These small or negative weight changes were '
given the same value, <0.3 mg, which was used to derive those ef-
ficiencies given as inequalities. The concentrations derived from
these inequalities and the efficiencies calculated therefrom are
marked with an asterisk to emphasize that they are assumed values.
The following tests were run but not reported for the reasons
indicated:
'//I - Sample nozzles not blocked when not sampling.
#2 - Sample nozzles not blocked when not sampling.
#3 - Dynactor components melted at 300°F.
//6 - Downstream sampling time too short for appreciable
impactor weights.
3
#11 - Inlet dust concentration too low (0.03 gr/ft )
#15 - Downstream impactor not connected to pump.
#20 - Screw feed auger failed.
80
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 4
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
104 cm W£
INLET CONCENTRATION- .86 gr/ft3 =1979 mg/m
3 3
OUTLET CONCENTRATION .031 gr/ft =71.4 mg/m
.964
., TOTAL MASS EFFICIENCY
J 3
FLOW: 500 ft /min = 14.2m /min Total Spray: 18.4 gal/min
21 °C 1.16 x 10" m /sec
TEMPERATURE:
70 °F
REMARKS: Size distribution obtained from impactors at 1.0 cfm flow was
interpolated to'match sizing intervals for impactors at 0.5 cfm flow.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nvVmin)
1.0 = .028
1.0 » .028
1.0 - .028
1.0 = .028
DURATION
(min)
1.
1.
15.
15.
TOTAL VOLUME
(ft3) (m1)"
1.0 = .028
1.0 = .028
15.0 = .43
15.0 = .43
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
AERODYNAMIC
DIAMETER
STAGE (nm)
1 >_ 9.0
2 6.0 - 9.0
3 4.0 - 6.0
4 2.8 - 4.0
5 1.8 - 2.8
6 0.90 - 1.8
7 .54 - 0.90
8 0.36 - 0.54
Final filter 0.36
TOTAL, Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
< 10.6*
1 31.8*
106.0
191.0
311.0
374.0
31.8
< 10.6*
17.7
1074.
OUTLET
CONCENTRATION
(mg/m3)
< .7*
<_ .7*
1.2
2.8
8.5
29.9
17.7
3.1
1.4
66.0
FRACTIONAL
MASS
EFFICIENCY
(percent)
__
--
98.5
97.3
92.0
44.4
£ 71.1*
92.0
93.9
81
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEMPERATURE:
o
205 F =
INLET CONCENTRATION ~ .8 gr/ft3 = ~2000 mg/m3
OUTLET CONCENTRATION .040 gr/ft3 = 91.4 mg/m3
TOTAL MASS EFFICIENCY ~.95
'mm *.«»"». wr^w_,.
= 1.16 x 10"J mJ/sec
TEST # 5
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 X
104 cm WC
FLOW: 500 ft3/min = 14.2 m3/min Total Spray: 18.4 gal/mit^
o
97 C
REMARKS: Size distribution obtained by impactors at 1.0 cfm flow was
interpolated to match sizing intervals for impactors at 0.5 cfm flow.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
1.0
1.0
1.0
1.0
RATE
(m-Vmin)
- .028
= .028
= .028
= .028
DURATION
(min)
1.
1.
15.
15.
TOTAL
(ft3)
1.0
1.0
15.
15.
VOLUME
(m3)
= .028
= .028
- .43
= .43
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
AERODYNAMIC .
DIAMETER
STAGE (urn)
1 > 9.0
2 6.0 - 9.0
3 4.0 - 6.0
4 2.8 - 4.0
5 1.7 - 2.8
6 0.90 - 1.8
7 0.54 - 0.90
8 0.36 - 0.54
Final filter 0.36
TOTAL, Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
< 3.5*
21.2
88.3
166.0
265.0
322.0
28.3
< 10.6*
<_ 10.6*
898.0
OUTLET
CONCENTRATION
(mg/m3)
--
--
1.4
6.8
13.0
23.6
4.2
.7.
49.7
FRACTIONAL
MASS
EFFICIENCY
(percent)
--
--
--
97.4
96.0
16.7
< 60.0*
£.93.3*
94,3
82
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 7
3 3
INLET CONCENTRATION ~ 0.7 gr/ft = ~1600 mg/ra
AEROSOL Fly ash
NOZZLE: 200 psig = 1.4 x
cm WC
-^ i . i / n -j
3 3
OUTLET CONCENTRATION .0059gr/ft = 13.6 mg/m
TOTAL MASS EFFICIENCY ~ .99
FLOW: 500 £t /min = 14.2 m /min Total Spray: 18.4 gal/min 3
o o o = 1.16 x 10 m /sec
TEMPERATURE: 200 F = 95 C
REMARKS: Inlet concentration sampler malfunctioned, so inlet concentra-
tion (0.7 gr/ft3) estimated from other tests.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nvVmin)
1.0 = .028
.5 = .014
1.0 = .028
.5 = .014
DURATION
(min)
3.
3.
69.
90.
TOTAL
(ftj)
3.0
1.5
69.
45.
VOLUME
(mj)
= .085
- .043
= 1.95
= 1.27
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(urn)
»13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.'54 - 0.80
Final filter £0.54
TOTAL,
Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
37.7
118.
186.
141.
113.
82.
21.2
< 7.1*
< 7.1*
704.
OUTLET
CONCENTRATION
(mg/m3)
< .24*
< .24*
< .24*
< .24*
.5
3.2
4.0
2.9
4.0 .
14.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
--
--
--
--
99.5
96.1
81.1
< 58.9*
< 43.3*
97.9
83
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 8
AEROSOL Fly ash
INLET CONCENTRATION .90 gr/ft3 =2076mg/m3
OUTLET CONCENTRATION .0067gr/ft3 = 15.4mg/m3
FLOW:
TEMPERATURE:
TOTAL
EFFICIENCY -993
500 ft /rain = 14.2 m /min Total Spray: 18.4 gal/min- «
= 1.16 x 10" m /sec
70
21 °C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (nrfymin)
1.0 = .028
.5 = .014
1.0 = .028
.5 = .014
DURATION
(min)
2.
3.
88.
90.
TOTAL VOLUME
(ftj) (m-*)
2.0 = .057
1.5 = .043
88. =2.49
45. = 1.37
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMF ACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(lam)
>13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
61.2
160.
278.
151.
132.
80.
19.
. 0.54 - 0.80 i < 7.0*
filter £0.54
Anderson Inipnctor
< 7.0*
881.
OUTLET
CONCENTRATION
(mg/m3)
< .2*
< .2*
V
< .2*
< .2*
.5
3.5
4.1
3.0
2.0
13.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
__
--
--
--
99.6
95.6
78.3
< 57.8*
< 72.2*
98.5
84
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #9
AEROSOL Fly Ash
NOZZLE: 200 psig = 1.4 x
104 cm WC
FLOW: 1000
INLET CONCENTRATION .25 gr/ft = 568 mg/m
OUTLET CONCENTRATION .OOL5gr/ft3 = 3.3 mg/m3
TOTAL MASS EFFICIENCY .994
TEMPERATURE:
ft /min =28.3 m/min Total Spray: 18.4 gal/rain. _
= 1.16 x 10 m /sec
68 °F =
20 C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nvVmin)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
16.
26.
296.
300.
TOTAL
(ft3)
20.
13.
592.
150.
VOLUME
(m3)
.57
.37
= 16.8
4.3
FACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
AERODYNAMIC .
DIAMETER
STAGE (urn)
1 > 13.6
2 8.6 - 13.6
3 5.6 - 8.6
4 4.0 - 5.6
5 2.5 - 4.0
6 1.3 - 2.5
7 0.80-1.3
8 - 0.54 - 0.80
Final filter< 0. 54
TOTAL, Andersen Inpactor
INLET
CONCENTRATION
(mg/m3)
7.3
16.3
29.6
22.3
20.9
13.0
4.9
< .8*
< .8*
114.
OUTLET
CONCENTRATION
(mg/m3)
<.07 *
<.07 *
<.07 *
<.07 *
.14
.82
1.2
.72
.40
3.3
FRACTIONAL -.
MASS
EFFICIENCY
(percent)
-._
--
--
--
99.3
93.7
74.5
< 50.9*
< 10.4*
97.0
85
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 10
INLET CONCENTRATION.0.17 gr/ft3 - 396 mg/m3
OUTLET CONCENTRATION .0015gr/ft3 =3.5 mg/m3
AEROSOL Fly ash
NOZZLE: 200 paig = 1.4 x ^^ ^ EmcIENCY <991
1U Cut WO ^
FLOW: 1000 ft /min = 28.3 ni /min Total Spray: 18.4 gal/mil^ 3
o o = 1.16 x 10 m /sec
TEMPERATURE: 200 F = 95 C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft3/min)
2.0
0.5
2.0
0.5
RATE
(m3/min)
= .057
= .014
= .057
= .014
DURATION
(min) .
10
20
240
240
TOTAL
(ft3)
20
10
480
120
VOLUME
(m3)
.57
.28
= 13.6
= 3.4
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
AERODYNAMIC
DIAMETER
(lim)
1 »13.6
2
3
4
5
6
7
8
Final
TOTAL,
8,6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - 0.80
filter£0.54
Anderson Impactor
INLET
CONCENTRATION
(mg/m3)
3.2
12.7
25.1
15.5
14.1
9.9
1.4
< 1.1*
< 1 . 1 *
82.3
OUTLET
CONCENTRATION
(mg/m3)
< .09*
< .09*
< .09*
< .09*
.15
.8
1.2
.7
.6
3i45
FRACTIONAL-
MASS
EFFICIENCY
(percent)
_ _
--
--
-_
99.0
92.0
12.5
< 36.1*
< 44.4*
95.8
86
-------
DYKACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 12
INLET CONCENTRATION .244 gr/ft3 = 560 mg/m
3 3
OUTLET CONCENTRATION.0244 gr/ft = 56 mg/m
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
10^ cm WC TOTAL MASS EFFICIENCY .900
FLOW: 1000 ft /min = 28.3m /rain Total Spray: 18.4gal/min3 -
Qi, o_ = 1.16 x 10 m /sec
TEMPERATURE:
70 F
21 C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft^/min)
2.0
0.5
2.0
0.5
RATE
(m-Vmin)
= .057
= .014
= .057
= .014
DURATION
(min) -
5
10
50
120
TOTAL
(ftj)
10
5
100
60
VOLUME
(m3)
.28
.14
= 2.8
= 1.7
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(lim)
£13. 6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - 0.80
Final filter £ 0. 54
TOTAL,
Andersen Inpactor
INLET
CONCENTRATION
(mg/m3)
< 2.1*
16.3
34.6
67.1
124.
188.
146.
25.4
< 2.1*
605.
OUTLET
CONCENTRATION
(mg/m3)
< .2*
< .2*
.4
1.0
3.8
14.6
21.4
18.2
6.4
65.9
FRACTIONAL'
MASS
EFFICIENCY
(percent)
--
--
99.0
98.5
96.9
92.3
85.3
28.5
< 0.0*
89.1
87
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 13
INLET CONCENTRATION .33 gr/ft3 = 747 mg/m3
AEROSOL Iron oxide OUTLET CONCENTRATION .059 gr/ft = 135 mg/m
NOZZLE: 100 psig = 7 x 103
_
cm
TOTAL MASS EFFICIENCY .818
. _
FLOW: 1000 ft /min = 28.3m /min Total Spray: 13.2 gal/min
TEMPERATURE:
80 °F = 27 °C = .58 x 10~3 m3/sec
REMARKS: Nozzles used at 100 p.'s.i.g. = 6.9 x 10
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ftj/min) (m3/min)
2.0 = .057
.5 = .014
2.0 = .057
.5 = .014
DURATION
(min)
4'.0
4.0
40.
40.
TOTAL
(ft3)
8.0
2.0
80.
20.
VOLUME
(in3)
.23
.057
= 2.3
.57
FRACTIONAL EFFICIENCY DATA, ANDERSEN IHPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(tarn)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
< 5.3*
7.1
33.6
54.8
124.
210.
147.
. 0.54 - 0.80 ! 15.9
filter£0.54
Andersen Inpactor
< 5.3*
599.
OUTLET
CONCENTRATION
(mg/m3)
1.6
1.6
2.3
5.3
15.4
45.4
59.
15.9
5.5
152.
FRACTIONAL
MASS
EFFICIENCY
(percent)
_ _
77.5
93.2
90.3
87.6
78.4
60.0
0.0
< 0.0*
74.6
88
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 14
INLET CONCENTRATION
.118 gr/ft3 = 271 mg/m3
OUTLET CONCENTRATION .016 gr/ft = 36.6mg/m3
.866
AEROSOL iron oxide
NOZZLE: 200 psig - 1.4 x TOTAL EFFICIENCY
10^ cm W,C ~
FLOW: 1000 ft /min = 28.3 m /min Total Spray: 18.4 gal/min
°- - - °- = 1.16 x 10"
TEMPERATURE:
203 F
95 C
/sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (m3/min)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
4.
4.
40.
40.
TOTAL VOLUME
(ft3) (m3)
8. = .226
2. = .057
80. = 2.26
20. = .566
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(>am)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
. 0.54 - 0.80
filter£0.54
Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
< 5.2*
< 5.2*
7.1
10.6
30.0
97.2
67.1
< 5.2*
< 5.2*
215.5
OUTLET
CONCENTRATION
(mg/m3)
< .5*
< .5*
< .5*
< .5*
1.4
10.4
15.9
8.1
< .5*
36.0
FRACTIONAL
MASS
EFFICIENCY
(percent)
_ _
--
--
--
95.3
89.3
76.3
< 0*
-
83.3
89
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST* 16 INLET CONCENTRATION 1.01 gr/ft3 =2311mg/ir3
AEROSOL iron oxide OUTLET CONCENTRATION .047 gr/ft = 107 mg/m3
NOZZLE: 200 Psig - 1.4 x TQTAL mss EFFICIENCY -954
Itr* cm w.C ' ~
FLOW: 1000 ft /min = 28.3m /min Total Spray: 18.4 gal/min-j 3
o o = 1-16 x 10 m /sec
TEMPERATURE: 63 F = 17 C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft-Vmin)
2.0
0.5
2.0
0.5
RATE
(m-Vmin)
= .057
= .014
= .057
= .014
DURATION
(min)
l-.O
2.0
4.5
15.0
TOTAL
(ft3)
2.0
1.0
9.0
7.5
VOLUME
(tn3)
= .057
= .028
= .255
= .212
FACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(tim)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
. 0.54 - 0.80
Final filter ^0.54
TOTAL,
Andersen Iinpcictor
INLET
CONCENTRATION
(mg/m3)
49.5
70.7
159.
180.
254.
375.
258.
60.1
17.7
1424.
OUTLET
CONCENTRATION
(mg/m3)
< 1.4*
< 1.4*
< 1.4*
< 1.4*
4.7
25.4
33.0
17.4
< 1.4*
81.5
FRACTIONAL
MASS
EFFICIENCY
(percent)
.
__
--
--
98.1
93.2
87.2
71.0
> 92.0*
94.3
90
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 17
INLET CONCENTRATION .84 gr/ft =1922 mg/m
3 3
OUTLET CONCENTRATION .042 gr/ft = 96 mg/m
TOTAL MASS EFFICIENCY .950
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
104 cm WC
FLOW: 1000 ft /min = 28.3m /min Total Spray: 18.4 gal/min3 3
o o = 1.16 x 10 m /sec
TEMPERATURE: 70 F = 21 C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft^/min)
2.0
0.5
2.0
0.5
RATE
(m-Vmin)
= .057
= .014
= .057
= .014
DURATION
(min)
1.
2.
15.
15.
TOTAL
(ft3)
2.0
1.0
30.
7.5
VOLUME
(mj)
= .057
= .028
= .85
= .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC .
DIAMETER
(urn)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
. 0.54 - 0.80
Final filter £0.54
TOTAL,
Andersen Irapactor
INLET
CONCENTRATION
(mg/m3)
24.7
53.0
148.
187.
307.
382.
205.
21.2
< 10.7*
1336.
OUTLET
CONCENTRATION
(mg/m3)
< 1.4*
< 1.4*
< 1.4*
1.9
5.2
25.9
39.1
18.4
?.8
95.2
FRACTIONAL -.
MASS
EFFICIENCY
(percent)
--
--
--
--
98.3
93.2
80.9
13-3
< 73.3*
92.9
91
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 18
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
INLET CONCENTRATION .872 gr/ft3 = 1996 mg/m3
OUTLET CONCENTRATION .038 gr/ft3 =86.6mg/n3
FLOW:
TEMPERATURE:
4 '7^ "'' " TOTAL MASS EFFICIENCY .957
O4 cm W.C ,
1000 ft: /ml n =28.3 m /rain Total Spray: 18.4 gal/min
70 °F =
21 °C
-3 3
= 1.16 x 10 m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nrVmin)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
1.0
2.0
15.0
15.0
TOTAL VOLUME
(ft-*) (m-»)
2.0 = .057
1.0 = .028
30. = .85
7.5 = .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC .
DIAMETER
(nm)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
.0.54 - 0.80
filter £0.54
Andersen Inipactor
INLET
CONCENTRATION
(mg/m3)
21.2
53.0
198.
205.
322.
343.
198.
28.3
< 10.7*
1378.
OUTLET
CONCENTRATION
(mg/m3)
< 1 .4*
< 1 .4*
< 1 .4*
< 1 .4*
2.8
24.0
33.5
12.7
1-.9
74.9
FRACTIONAL .
MASS
EFFICIENCY
(percent)
_
--
--
--
99.1
93.0
83.1
55.0
< 82.2*
94.6
92
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 19
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
104 cm WC
IN1JET CONCENTRATION
.679 gr/ft3 -1553mg/rc3
FLOW:
TEMPERATURE:
3 3
OUTLET CONCENTRATION .035gr/ft =79.1mg/m
TOTAL MASS EFFICIENCY -949
3
1000 ft /min = 28.3m3/min Total Spray: 18.4gal/min
o - 1.16 x 10 m /sec
95 C
203 °F =
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (m3/min)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
1:0
2.0
14.0
14.0
TOTAL
(£tj)
2.0
1.0
28.
7.
VOLUME
(mj)
= .057
= .028
= .792
= .198
FRACTIO::AL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL ITI
STAGE
AERODYNAMIC .
DIAMETER
(^m)
1 £13.6
2
3
4
5
6
7
8
Final
TOTAL,
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
.0.54 - 0.80
filter£0.54
Andersen Inpactor
INLET
CONCENTRATION
(mg/m3)
24.7
56.5
191.
166.
272.
286.
170.
17.7
< 10.7*
1194.
OUTLET
CONCENTRATION
(mg/m3)
< 1.5*
< 1.5*
< 1.5*
< 1.5*
6.6
28.8
40.9
15.6
3.5
98.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
__
--
--
--
97.6
89.9
75.9
11.4
< 66.7*
91.7
93
-------
DYNACTOR SCRUBBKR EFFICIENCY EVALUATION DATA
TEST #21
INLET CONCENTRATION -955 gr/ft3 =2186mg/m3
OUTLET CONCENTRATION -Oil j;r/ft3 = 25.3mg/m3
TOTAL MASS EFFICIENCY .988
AEROSOL Fly ash
NOZZLE: 200 psig = 1.4 x
10^ cm WC .,
FLOW: 1000 £t /min = 28.3 m /min Total Spray: 18.4 gal/min3 3
TEMPERATURE: 70 °F = 21 °c = 1>16 x 10" m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (m3/min)
2.0 = .057
0.5 = .014
2.0 - .057
0.5 = .014
DURATION
(min)
3.0
3.0
57.5
60.0
TOTAL
(ft3)
6.0
1.5
115.
30.
VOLUME
(in3)
= .171
- . 042
= 3.25
= .84
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
i
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC .
DIAMETER
(um)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m^)
40.0
. 75.4
153.
115.
80.1
73.0
28.3
0.54 - 0.80 i < 7.1*
filter $0.54
And or sen Inp^.ctor
< 7.1
575.
OUTLET
CONCENTRATION
(mg/m3)
< .4*
< .4*
< .4*
< .4*
1.2
6.8
11.0
5.9
i.-l
26.4
FRACTIONAL .
MASS
EFFICIENCY
(percent)
-.
--
-_
--
98.5
90.6
61.3
< 16.7*
< 85.0*
99.4
94
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 22
AEROSOL Fly ash
NOZZLE: 200 psig = 1.4 x
1C4 cm
FLOW: 1000 ft
3 3
INLET CONCENTRATION 1.30 gr/ft =2984mg/m
3 3
OUTLET CONCENTRATION .012 t;r/ft = 27.4ms/T-
TEMPERATURE:
Wf~ TOTAL MASS EFFICIENCY .991
t /min = 28.3ra /rain Total Spray: 18.4 gal/nun-
. "
203 F = 95 C
= 1.16 x 10
m
/sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ftj/min)
2.0
0.5
2.0
0.5
RATE
(nrVmin)
= .057
= .014
= .057
= .014
DURATION
(min)
3.0
3.0
58.0
60.0
TOTAL
(ftj)
6.0
1.5
116.
30.
VOLUME
(tn-5)
= .171
= .042
= 3.28
- .84
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
£13. 6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
84.8
155.
229.
127.
115.
80.1
30.6
0.54 - O.SO | < 7.1*
Final filter £0.54
TOTAL,
Andersen Iropactor
< 7.1*
822.
OUTLET
CONCENTRATION
(mg/rn3)
< -4*
< .4*
< .4*
< .4*
1.4
9.2
9.2
4.6
1-. 8
26.9
FRACTIONAL '
MASS
EFFICIENCY
(percent)
.._
--
--
98.8
88.5
70.0
< 35.0*
__ =
< 75.0* .
96.7
95
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 23
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
cm tJC
INLET CONCENTRATION .178 gr/ft3 =408 mg/m3
OUTLET CONCENTRATION .010 gr/ft3 = 23.2nig/m3
TOTAL MASS EFFICIENCY .943
o
50.0 ftJ/min = 14.2 m /min Total Spray: 18.4 gal/min
TEMPERATURE: 66 °F = 19°C
FLOW:
-3 3
1.16 x 10 m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft-Vmin)
1.0
0.5
1.0
0.5
RATE
(m-Vmin)
.028
.014
.028
.014
DURATION
(min)
15
15
118
120
TOTAL
(ft-3)
15.0
7.5
118
60
VOLUME
(m3)
= .424
= .212
= 3.34
= 1.70
FRACTIONAL EFFICIENCY DATA ,_ ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(um)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
. 0.54 - 0.80
Final filter £0.54
TOTAL,
Andersen Inpnctor
INLET
CONCENTRATION
(mg/m3)
< 1. 4*
< 1.4*
6.1
12.2
27.3
48.5
32.5
1.9
< 1.4*
131.
OUTLET
CONCENTRATION
(mg/m3)
< .2*
< .2*
< .2*
< .2*
.6
4.4
7.6
4.9
1.1
18.7
FRACTIONAL
MASS
EFFICIENCY
(percent)
..
--,
.
M
97.8
91.0
76.6
< 0 *
< 25.0*
85.6
96
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 24
AEROSOL Iron oxide
NOZZLE: 200 psig = 1,4 X
cm WC
FLOW: 500 ft /min
TEMPERATURE:
203 °F -
14.2
INLET CONCENTRATION .187 gr/ft3 = 428 mg/m3
OUTLET CONCENTRATION .014 gr/ft" =32.6
TOTAL MASS EFFICIENCY .924
3,
Total Spray: 18.4 gal/min _
= 1.16 x 10 m /sec
m /min
95 °C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m3/min)
1.0 = -028
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(rain)
15
15
84
120
TOTAL
(ft3)
15.0
7.5
84
60
VOLUME
(m3)
= .424
= .212
= 2.38
= 1.70
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(urn)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
2.8
3.3
10.8
16.5
39.6
71.1
56.5
0.54 - 0.80 ! 12.7
filter £0.54
Andersen Inpactor
< 1.4*
213.
OUTLET
CONCENTRATION
(mg/m3)
< .18*
.24
.29
.35
1.5
7.2
9.8
6.5
2.4
28.3
FRACTIONAL '
'MASS
EFFICIENCY
(percent)
.. _
92.9
97.3
97.9
96.3
89.9
82.7
49.1
< 0 *
86.7
97
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 25
AEROSOL Iron oxide
NOZZLE: 200 psig = 1.4 x
104 cm WC
IOC
TEMPERATURE:
INLET CONGENTRATION .615 gr/ft - 1406mg/m3
OUTLET CONCENTRATION .027 gr/ft3 = 62.9mg/m3
EFFICIENCY
FLOW: 1000 ft' /min =28.3 m /min Total Spray: 18.4 gal/min
o_ _o_ = 1.16 x 10 m /sec
70 F =
21 C
REMARKS: Approximately 10 ppm surfactant added to spray water.
SAT-EPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ffVmin) (m3/min)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
1;
2.
15.
15.
TOTAL
(ft3)
2.0
1.0
30.
7.5
VOLUME
On3)
= .057
~ . 028
= 1.71
= .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(l^m)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
.0.54 - 0.80
Final filter £0.54
TOTAL,
Andersen Inipnctor
INLET
CONCENTRATION
(mg/m3)
14.1
24.7
117.
141.
223.
307.
187.
21.2
< 10.7*
1039.
OUTLET
CONCENTRATION
(mg/m3)
< 1.43*
< 1.43*
< 1.43*
< 1.43*
1.89
17.9
28.3
8.0
1.89
58.0
FRACTIONAL
MASS
EFFICIENCY
(percent)
«. ..
--
--
99.2
94.2
84.9
62.2
< 82.2*
94.4
98
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 26
AEROSOL Fly ash
NOZZLE: 200 psig = 1.4 x
10^ cm WC
FLOW: '"" "
500 ft /min = 14.2 m /min
TEMPERATURE:
85 °F =
INLET CONCENTRATION .121 gr/ft3 = 276 mg/m3
OUTLET CONCENTRATION002 gr/ft3 =3.9 mg/m3
TOTAL MASS EFFICIENCY 98.6
3,
Total Spray: 18.4 gal/min
1.16 x 10"J m /sec
29 °C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ftj/min) (nrVmin)
1.0 = .028
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
25.
25.
268.
270.
TOTAL VOLUME
(ft3) (m-»)
25.0 = .708
12.5 = .354
268. =7.58
135. =3.82
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(um)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - 0.80
filter £0.54
Andersen Inpactor
INLET
CONCENTRATION
(mg/m3)
12.7
26.0
41.8
24.3
24.0
17.5
10.5
< .8*
< .8*
158.
OUTLET
CONCENTRATION
(mg/m3)
< . 1 *
< .1*
< .1*
< .1*
< .1*
.7
1.4
.9 .
.3
3.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
« M
--
--
--
--
96.0
86.7
< 0 *
< 62.5*
97.8
99
-------
DYNACTOR_SCRUBBER EFFICIENCY EVALUATION DATA
TEST #27
AEROSOL Fly Ash
NOZZLE: 200 psig = 1.4 X
10'
FLOW:
INLET CONCENTRATION .136gr/ft3 = 311 nig/m3
OUTLET CONCENTRATION .002 gr/ft3 = 4.2 mg/m3
cm wc TOTAL MASS EFFICIENCY ..986
500 ft3/min =14.2 m3/min Total Spray: 18.4 gal/rain
1 iA v in" /
TEMPERATURE: 200 °F = 95 °C ' m f sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nvVmin)
1.0 = .028
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
25
25
243
293
TOTAL
(ft3)
25
12.5
243
146.5
VOLUME
(m3)
= .708
= .354
= 6.88
= 4.15
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(urn)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m^)
10.2
22.9
36.5
24.0
21.2
16.7
11.6
0.54 - O.SO 1 !.?
filter £ 0.54
Andersen Impactor
< .8*
145
OUTLET
CONCENTRATION
(mg/m^)
< .07*
< .07*
< -07*
< .07*
< -07*
.58
1.4
.89
.46
3.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
« fm
--
--
--
--
96.5
87.7
47.5
< 45.8*
97.7
100
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #28
INLET CONCENTRATION
gr/ftJ =
mg/m~
AEROSOL IRON OXIDE (steam) OUTLET CONCENTRATION .021 gr/ft3 = 47.8mg/m3
TOTAL
EFFICIENCY
FLOW: 500 ftJ/min = 14.2 m3/min Total Spray: 18.4 gal/tnin
TEMPERATURE:
F =
-3 3
= 1.16 x 10 m /sec
REMARKS: Spray introduced in inlet duct. Humidity ratio of
approximately .044.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (m3/min)
Broken = line, si
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
,mple void
2
15
15
TOTAL
(ft3)
1
15
7.5
VOLUME
(mj)
=
= .028
= .42
= .21
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
AERODYNAMIC
DIAMETER
(um)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - 0.80
Final filter £0.54
TOTAL,
Andersen Impactpr
INLET
CONCENTRATION
(mg/m3)
67.1
110
216
216
251
318
198
28.3
< 10.6*
1403
OUTLET
CONCENTRATION
(mg/m3)
< 1.41*
< 1.41*
< 1.41*
< 1.41*
1.88
16.0
28.3
14.6
3.77
64.5
FRACTIONAL
MASS
EFFICIENCY
(percent)
__
--
--
99.3
95.0
85.7
48.4
< 64.4*
95.4
101
-------
DYNACTOR SCRULBER EFFICIENCY EVALUATION DATA
TEST # 29
INLET CONCENTRATION .581 gr/ft3 =1329 mg/m3
OUTLET CONCENTRATION .025 gr/ft3 = 57.1mg/m3
AEROSOL Iron Oxide
NOZZLE: 200 psig = 1.4 X
104 cm WC
FLOW: 1500 ft /min = 42.5 m3/min Total Spray: 18.4 gal/min
TOTAL MASS EFFICIENCY .948
TEMPERATURE:
70°F =
21°C
-3 3
= 1.16 x 10 m /sec
REMARKS:
Data corrected for leakage between inlet and outlet.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
. (ft-Vmin) (nrVmin)
1.0 = .028
0.5 = .014
2.0 = .056
0.5 = .014
DURATION
(min)
2
2
15
15
TOTAL VOLUME
(ft-1) (m-»)
2.0 = .056
1.0 = .028
30 = .85
7.5 = .21
FRACTIONAL EFFICIENCY DATA, ANDERSKN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(lam)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - 0.80
filter £0.54
Andersen Irnpactor
INLET
CONCENTRATION
(mg/m3)
10.6
28.3
81.3
67.1
134
177
134
< 10.6 *
< 1Q. 6 *
633
OUTLET
CONCENTRATION
(mg/m3)
< 1.41 *
'< 1.41 *
< 1.41 *
< 1.41 *
3.30
18.8
27.8
7.07
< 1.41 *
58.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
--
--
--
--
97.0
87.1
75.0
< 19.4 *
--
88.9
102
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 30
INLET CONCENTRATION .571 gr/ft3 = 1306mg/m3
OUTLET CONCENTRATION .025 gr/ft3 = 57.6mg/m3
AEROSOL Iron Oxide
NOZZLE: 200 psig = 1.4 x
104 cm WC -
1500 ft /min =42.5 m /min Total Spray: 18.4 gal/min
TOTAL MASS EFFICIENCY .947
FLOW:
TEMPERATURE:
190°F =
88°C
-3 3
1.16 x 10 m /sec
REMARKS :
Data corrected for leakage between inlet and outlet.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ftj/min) (m3/min)
1.0 = .028
0.5 = .014
2.0 = .056
0.5 = .014
DURATION
(min)
2
2
15
15
TOTAL VOLUME
(ft3) (m3)
2.0 = .056
1.0 = .028
30 = .85
7.5 = ' .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(nm)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 . - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
35. .3
63.6
124
106
163
198
148
0.54 - 0.80 I 14.1
filter £0.54
Andersen Imps c tor
< 10.6 *
852
OUTLET
CONCENTRATION
(mg/m3)
< 1.41*
< 1.41*
< 1.41*
< 1.41*
1.9
17.4
20.7
2.8 -
< 1.41 *
43.3
FRACTIONAL
. MASS
EFFICIENCY
(percent)
..
--
--
--
98.6
89.4
83.1.
75.8
-
93.8
103
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #31
INLET CONCENTRATION .504 gr/£t3 = 1153mg/m3
AEROSOL Iron Oxide (steam) OUTLET CONCENTRATION .019 gr/ft3 =44.4
NOZZLE: 200 psig = 1.4 x
104 cm WC TOTAL MASS EFFICIENCY .962
FLOW: 500ft"/min = 14.2m /min Total Spray: 18.4 gal/min
TEMPERATURE:
=1.16 x 10"3 m3/sec
REMARKS: Spray in inlet duct humidity ratio of approximately .072.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft-Vmin)
1.0
0.5
1.0
0.5
RATE
(m-Vmin)
= .028
= .014
= .028
= .014
DURATION
(min)
5
5
25
25
TOTAL
(ft3)
5.0
2.5
25
12.5
VOLUME
(m3)
= .14
= .07
= .70
= .35
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(^im)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
INLET
CONCENTRATION
(mg/m3)
11.8
17.0
41.0
48.1
102
184
90.5
0.54 - 0.80 j 17.0
filter £0.54
Andersen Irip;>.ctor
< 4.2 .*
510
OUTLET
CONCENTRATION
(rag/m3)
< .8 *
< .8 *
< .8 *
< .8 *
1.1
11.0
17.8
5.1 .
< .8 *
35.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
..
__
--
--
98.9
94.0
80.3
70.0
-
93.0
104
-------
DYNACTOll SCRUBBER EFFICIENCY F.VALUATION DATA
TEST # 32
AKROSOL Iron Oxide
NOZZLE: 200 psig = 1.4 x
104 cm WC
3 3
INLET CONCENTRATION .286 gr/ft = 654 mg/ir.
3 3
OUTLET CONCENTRATION - gr/ft = - mg/m
TOTAL MASS EFFICIENCY -
FLOW: 1000 ft /rain =28.3 m /min Total Spray: 18.4 gal/min
TEMPERATURE:
80°F =
27°C
= 1.16 x 10"3 tn3/sec
REMARKS: Downstream sampling done between the first and second
Dynactor stages.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m3/min)
1.0= .028
0.5 = .014
= .
0.5 = .014
DURATION
(min)
3
3
-
10
TOTAL VOLUME
(ft3) (m3)
3.0 = .084
1.5 = .042
= -
5.0 = .14
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(iam)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
1.3 - 2.5
0.80 - 1.3
0.54 - O.SO
filter <; 0.54
Andersen Inpnctor
INLET
CONCENTRATION
(mg/m3)
14.1
28.3
70.7
80.1
127
184
130
16.5
< 7.1*
650
OUTLET
CONCENTRATION
(mg/m3)
< 2.1*
< 2.1*
2.8
6.4
19.1
53.7
38.9
6.4
< 2.1*
129
FRACTIONAL
MASS
EFFICIENCY
(percent)
--
« »
96.0
92.1
85.0
70.8
70.0
61.4
-
80.1
103
-------
TECHNICAL REPORT DATA
(I'lcaic read Inwiielions on llie reverse before completing)
1. RtPORT NO.
EPA-650/2-74-083-a
2.
3. RECIPIENT'S ACCESSION*NO.
4. TITLE ANOSUBTITLE
Dynactor Scrubber Evaluation
5. REPORT DATE
June 1975
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO
D.W. Cooper and D. P. Anderson
GCA-TR-74-21-G
9. PERFORMING ORGANIZATION NAME AND ADDRESS
GCA Corporation
GCA/Technology Division
Burlington Road
Bedford, MA 01730
10. PROGRAM ELEMENT NO.
1AB012; ROAP 21ADL-004
11. CONTRACT/GRANT NO.
68-02-1316, Task 6
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
NERC-RTP, Control Systems Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final: Through 7/26/74
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The report gives results of testing a novel aspirative spray scrubber, the Dynactor
(RP Industries, Hudson, MA), for power consumption and collection efficiency at
three flow rates, two temperatures, two dust loading levels, and for two different
dusts. Higher efficiencies were fostered by: lower flow rate, lower inlet temperature
and higher mass loading. The collection efficiency of the Dynactor was not substan-
tially different from that expected for a well-designed venturi scrubber operating at
the same power level and air flow rate. As with other scrubbers of similar power
consumption, collection efficiency decreased sharply for fine particles smaller than
1 /am aerodynamic diameter.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/CPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Scrubbers
Performance Tests
Dust Collectors
Efficiency
Air Pollution Control
Stationary Sources
Dynactor
Fine Particulate
Collection Efficiency
Power Consumption
13 B
07A
14 B
13A
8. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (ThisReport!
Unclassified
21. NO. OF PAGES
117
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
107
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