EPA-650/2-74-083
SEPTEMBER 1974
Environmental Protection Technology Series
:::::;;::;:::;i:;i;:;;:;:;i#
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EPA-650/2-74-083
DYNACTOR SCRUBBER
EVALUATION
by
D. W. Cooper and D. P. Anderson
GCA Corporation
GCA/Technology Division
Bedford, Massachusetts 01730
Contract No. 68-02-1316, Task 6
ROAP No. 21ADL-004
Program Element No. 1AB012
EPA Project Officer: D.L.Harmon
Control Systems Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
September 1974
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This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of tho Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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ABSTRACT
A novel aspirative spray scrubber, the Dynactor (RP Industries, Hudson,
Massachusetts), was tested for power consumption and collection ef-
ficiency at three flow rates, two temperatures, two dust loading levels,
for two dusts. Total filter samplers and cascade impact or s were used
upstream and downstream from the collector. Power was determined from
voltage, current, and phase angle measurements, A factorial design
series of tests at two levels of flow, concentration, temperature, and
dust type gave these average mass efficiencies: 99.0 percent for 4.0-
5.6 um aerodynamic diameter, 98.4 percent for 2.5-4.0 jim, 93.0 percent
for 1.3-2.5 ^m, 75.4 percent for 0.8-1.3 /im, 27.4 percent for 0.54-0.80^
and 47.4 percent for <0.54 jxm. Higher efficiency was fostered by:
lower flow rate, lower inlet temperature, higher mass loading. Power
consumption was about one-third of that expected from a venturi scrubber
operated at a pressure drop (1.0 x 10 N/m « 40 inches H-0) giving
equivalent collection efficiency. Collection efficiency for both the
Dynactor and the venturi scrubber decreases dramatically for fine
particles smaller than 1
This report was submitted in fulfillment of Task Order No. 6 under
Contract No. 78-02-1316 by GCA/Technology Division under the sponsorship
of the Environmental Protection Agency. Work was completed as of
July 26, 1974.
iii
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CONTENTS
ABSTRACT
LIST OF FIGURES
LIST OF TABLES
ACKNOWLEDGMENTS
Page No.
ill
v
vi
vlii
Section
I
II
III
IV
V
VI
VII
VIII
CONCLUSIONS
RECOMMENDATIONS
INTRODUCTION
TEST EQUIPMENT
RESULTS
DISCUSSION
APPENDICES
REFERENCES
1
2
3
'j
22
60
A-l
72
iv
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FIGURES
No. Page No.
1 Test System for Dynactor Two-stage Scrubber Evaluation,
Including Filter Samples (F), Thermometers (T), and
Pressure Gauge (P) 6
2 Details of Aerosol Concentration and Size Distribution
Measurement Section 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 13
4 Flow Velocity Profile in Inlet Ducting, Dynactor Test
Setup 19
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 27
9 Inlet,Size Distribution, Iron Oxide at 1000 cfm
(28 mJ/min) 30
10 Inlet Size Distribution, Fly Ash at 1000 cfm (28 m3/min) 31
11 Dynactor Scrubber Collection Efficiency Versus Particle
Aerodynamic Diameter, Effects of Loading and Dust Type 47
12 Dynactor Scrubber Collection Efficiency Versus Particle
Aerodynamic Diameter, Effects of Flow Rate and Inlet
Temperature 48
13 Collection Efficiency, 1.3-2.5 urn, Versus Flow for
Different Dusts, Temperatures, and Concentrations 51
14 Collection Efficiency Curves for Venturi Scrubbers and
Dynactor Efficiency Data 62
Al Single-stage Dynactor diffusion system cross sectional view A-2
A2 Two-stage Dynactor scrubber A-4
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TABLES
No. Page No.
1 Data From Two Andersen Mark III Cascade Impactors
Sampling Same Iron Oxide Aerosol (Mapico Black) at
28 Xpm cm New Media 11
2 Data From Two Andersen Mark III Cascade Impactors
Sampling Same Iron Oxide Aerosol (Mapico Black) at
28 ipm on Reclaimed Media (Final Flow in #4601 was
about 5 percent less than that of #4602) 12
3 Andersen Model III Impaction Substrate Losses 16
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 33
5b Test Matrix, Iron Oxide Aerosol 34
6 Summary of Results of 16 Collection Efficiency Tests
for Dynactor (Factorial Test Design) 36
7 Results of Statistical Analysis on Efficiency 38
8 Significance of Effects of Flow, Dust, Temperature, and
Concentration on Scrubber Collection Efficiency 46
9 Detailed Analysis of Interactions for Dynactor Efficiency
on 1.3 - 2.5 nm Aerosol Fraction (Stage #6) 50
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 53
11 Results of Dynactor Collection Efficiency Tests Under
Similar.Conditions except for Flow Rate (Iron Oxide,
- 1 g/m ) 55
12 Results of Dynactor Collection Efficiency Tests Under
Similar Conditions but With and Without Steam Addition
(Iron Oxide, 500 cfm - 0.24 m /sec, -v 1 g/m ) 57
13 Results of Dynactor Collection Efficiency Tests Under
Similar Conditions Except for the Addition of 10 ppm
Surfactant to the Spray Water 59
v i
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TABLES (Continued)
No. Page No.
14a Estimated Capital Cost of Dynactor System, Based On
Manufacturer's data (1973 dollars) 65
14b Estimated Capital Cost of High Energy Venturi Scrubbers,
Yielding Similar Collection Efficiency to Dynactor (1973
dollars) 66
vii
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ACKNOWLEDGMENTS
Information and support supplied by Stanley Rich, Vice President and
Technical Director of R P Industries, and by Dale Harmon, of Control
Systems, Environmental Protection Agency, are acknowledged and were
appreciated.
viii
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SECTION I
CONCLUSIONS
This evaluation was one of a series of such evaluations being conducted by
the Environmental Protection Agency to identify novel devices which are
capable of high efficiency collection of fine particulates. The Model
DY-12-F2 Dynactor Scrubber of R P Industries (Hudson, Massachusetts) which
was tested had substantially less than 99% collection efficiency on fine
particulates, those smaller than 2 /jm in diameter, and thus did not satisfy
this objective.
The following average mass efficiencies were observed at the nominal rated
3
flow (0.47 m /s, 1000 cfm) and at half its rated flow:
Size fraction Efficiency _
(aerosol aero- 0.47 m /s 0.24 m /s
dynamic diameter) (1000 cfm) (500 cfm)
4.0-5.6 urn 98.8 99.2
2.5-4.0 Mm 98.0 98.8
1.3-2.5 Mm 91.2 94.8
0.8-1.3 Mm 67.4 83.4
0.54-0.8 Mm 28.1 26.7
< 0.54 Mm 45.5 49.3
These efficiencies are similar to those expected from a venturi scrubber
with a pressure drop of 1.0 x 10 N/m (40 inch H-0). The Dynactor oper-
ates on about one-third the power of such a venturi. A comparison of
3
costs for a venturi scrubber and a Dynactor scrubber for a 19 m /s
(40,000 cfm) application indicated that the major difference between the
two would be about $40,000 to $50,000 per year savings in electrical
power costs (at $0.025/kWhr) for those using a Dynactor scrubber.
The following factors improved spray scrubber collection efficiency:
lower inlet temperature, lower air flow, higher particle mass concentra-
tion, higher nozzle pressure, surfactant addition.
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SECTION II
RECOMMENDATIONS
Although the Dynactor does not give high efficiency collection for
particles smaller than one micron diameter, in those applications for
which a venturi scrubber might be suitable, the use of a Dynactor
scrubber should be considered as one alternative. If collection
efficiency requirements and other considerations would require a
/ O
venturi scrubber with a pressure drop on the order of 1.0 x 10 N/tn
(40 inch H20), a Dynactor scrubber could be substituted with a
significant savings in power consumption and a comparable cost for
equipment and installation.
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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-
3
vice with a nominal rating of 1000 cfm (0.472 m /s), 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
• 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. Its
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-
pactors, 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
gauges. Electrical power consumption was measured using an induction
coil ammeter and an oscilloscope, from which current, voltage, and phase
angle could be obtained.
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.
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SECTION IV
TEST EQUIPMENT
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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HEATER/
BLOWER
DUST
FEEDER
STAGE
* 2
STAGE
t I
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
THERMBCTER
PCMP
CONDENSATION
INDICATOR
Figure 2. Details of aerosol concentration and size distribution
measurement sections
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HEATER/BLOWER
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
3
aerosol. The heater was rated at a maximum of 350 x 10 Btu/hr (1.03 x
10 joule/s). Its blower could provide 1400 cfm (0.66 m /s) 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-
5 2
ator was powered with pressurized air at 80 psig (5.5 x 10 N/m 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
-4 3
tests which were run at 28 .0pm (1 cfm or 4.7 x 10 m /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
-3 3
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 top
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 sub-
divided into intervals, and the upstream samples were run briefly at the
time mid-points of these intervals, essentially the analogue of a midr
point quadrature. The total filter samples had the same durations as
their impactor counterparts. To prevent material from being captured
by the probes upstream when a sample was not being taken, these probes
were blocked with removable baffles.
Consideration was given to correcting the data obtained with the up-
stream impactor for the volume of air that was in the drying chamber at
the beginning of each sample, approximately 2.4 liters of air, relas-
tively free of aerosol due to sedimentation, etc., between samples.
Generally each upstream sample was for a minute or two, thus 14 to 28
o
liters (0.5 to 1.0 ft ) , so that the relatively clean air wpuid be £rom
about 8 to 16 percent of the total sample. When we checked the flow
rate of the upstream impactor at the end of the test series, we found
that it had drifted from 14 4pm (0.5 cfm) to 17 ,0pm (0.6 .eftn), whereas
the downstream impactor had not drifted from 14 £pm.. The ,ayer,a£e con~-
tribution of this drift would be to make the concentrations upstream
seem 10 percent higher than they were, but the contribution from
relatively clean air would have made the concentrations seem 8 -to
percent too low, so these effects nearly cancelled each oifther.
net effect on flow and the 5-percent change in aerodynamic cutoff
eter in the upstream impactor were treated as negligible. The down-
stream impactor sampled for 10 minutes or so generally and the 2 per-
cent (2.4/140) effect on total volume sampled was also ignored.
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METTLER BALANCE (HIS) AND WEIGHING ERRORS
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
rag, 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 rag.
To check whether or not dessication made a substantial difference in
the impactor substrate material, we made 24 weighings before and after
dessicating the substrates for a day's duration. 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 and the weights of groups of four were com-
pared with the sum of the four individual weights. To lessen the like-
lihood 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 .0pm (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
10
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Table 1. DATA FROM TWO ANDERSEN MARK III CASCADE IMPACTORS SAMPLING SAME IRON
OXIDE AEROSOL (MAPICO BIACK) AT 28 Ipm ON NEW MEDIA
Impactor
Stage
1
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
Irapactor
#4601
2
4
7
12
23
77
96
97
100
Impactor
#4602
1
2
4
8
19
74
96
97
100
Effective
Diameter
(lim)
D50
9.6
6.0
4.0
2.75
1.75
0.9
0.54
0.36
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 ipm 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 R
Impactor
#4601
0.1
0.1
0.3
0.6
1.8
10.6
3.6
0.4
0.6
18.1 R
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
(um)
D50
9.6
6.0
4.0
2.75
1.75
0.9
0.54
0.36
< 0.36
Correlation coefficient:
0.999
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u
o
M
Q
§
P"
I-M
w
Figure 3.
10
6
w 4
1.5
.6
.5
.35
X #4601, RECLAIMED
© #4602, RECLAIMED
+ #4601
A #4602
Xfe
10
50
70
90
95
98 99
MASS PERCENTAGE LARfER THAN BCD
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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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.
The smallest weight change that could be read from the balance we used
was 0.1 mg, so that the weights are precise to within about + 0.05 mg,
which is also an estimate of the accuracy of the difference between
two weights which are nearly the same, the case that we had to deal
with in the main. In the comparisons of the two impactors, the ratio
of two weights for the same stages for the different impactors diverged
from unity significantly as the weights approach 0.1 mg, as expected
from the weighing precision.
These comparison tests show that the impactors are nearly identical in
performance, which is what is required in the tests of the Dynactor
collection efficiency.
LOSSES FROM IMPACTION SUBSTRATE MATERIAL
It has been reported by Bird, et al. (1973) that the substrate material
used in the impactor, cut from glass fiber filters, had 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 involving actually sampling
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 pro-
cedure of rinsing with methanol, dessicating for 12 hours or more,
14
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weighing, using, dessicating again, weighing again. To estimate this
loss we wanted to determine 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 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
as it came from the manufacturer (untreated) or it was washed in
methanol 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 or 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:
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.
We decided not to add a "loss correction" to the data, although
arguments can be made for doing so or not doing so. The usual total
weight change was approximately 20 mg divided among the eight stages
and final filter and a correction, if used, would have been
approximately 0.2 mg per stage. Disadvantages to making such a
15
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Table 3. ANDERSEN MODEL III IMP ACTION SUBSTRATE LOSSES
Treatment
Untreated
Most washed in
methanol
Washed in methanol
Washed in methanol
Test conditions
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
Weight loss
(nig)
-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
16
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correction are that the uncertainty in the correction would add to
uncertainty already present in the data and that the correction com-
plicates going from the raw data to the derived quantities (concen-
trations, efficiencies) and vice-versa. This problem of impactor.
substrate losses is under further investigation by the Environmental
Protection Agency (Control Systems).
DUCTING
3
For the tests conducted at flow rates of 500 cfm (0.24 m IB) 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 m3/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
17
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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
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 5 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 500,
1000, and 1500 cfm (14, 28, 42 m3/min) lev
Dynactor fractional collection efficiency.
1000, and 1500 cfm (14, 28, 42 m3/min) levels when testing the
This completes this section on the equipment used in the Dynactor
evaluation and some of the tests performed on this equipment.
18
-------
JC
•k
1 ^m • "
«k
»-
U 9
s
LJ
S
m
.05 .10 .15
i i I
• • • • f • * *•
1
1
1
1
1
k
1
1
1 ! i
10
M
X.
E
5
2468
POSITION ALONG DUCT DIAMETER,
inches
Figure 4. Flow velocity profile in inlet ducting,
Dynactor test setup
19
-------
X 12-POINT TRAVERSE
0 8-POINT
I
•
•
-------
1000
28
800
o600
I
^"-400
*:
20
.t
"
10
200
1 I 1
1
1 1 1 1
.1 .2 .3 .4 .5 .6 7 .8 3 ID
Ap,CENTER-LINE PITOT TUBE,
Figure 6. Volume flow rate versus center-line reading
with pitot tube, Dynactor test 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 H00
22
(1.2 x 10 N/m ) below ambient, and we noted that for pressure dif-
o 2
ferences across the device on the order of 1 inch H-O (2.5 x 10 N/m )
and 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 condi-
tions. The data for flow (at 1 atmosphere pressure and 70°F) versus
22
-------
pressure increase are given in Figure 7 for three different spray noz-
zle pressures, 100, 150, 200 psig (6.9, 10.4, 13.8 x 105 N/m2). The
usual operation of the device, according to the manufacturer, is with
2 2
pressure differences less than or about 1/2 inch H20 (1.2 x 10 N An ).
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 somewhat less than expected by the manufacturer;
the maximum pressures matched expectations.
POWER CONSUMPTION: PUMPS
The Dynactor scrubber spray nozzles are powered by two high-pressure
pumps that run on three-phase 207 volt electrical power. The formula
for the power consumption of an electrical device is given by:
P = ^i I V cos
in which
n = number of phases (here, 3)
P = power, watts
I - current magnitude, amps
V = voltage magnitude, volts
* = phase angle between voltage and current
The power was determined by measuring the voltage magnitude, the current
magnitude and the phase angle at three spray nozzle pressures: 100, 150,
and 200 psig (6.9, 10.4, 13.8 x 105 N/m2). The current and voltage
measurements were made at a point in the circuit before it branched to
feed the two pumps, giving total current in each phase wire and the
common voltage. The voltage was 206 to 207 volts regardless of nozzle
pressure settings, both nozzles being set to the identical pressures for
each measurement. The current readings in each of the phase wires were:
23
-------
900 i
(
600
2
U_
O
3:
o
u_
300
N / m
.5xl02 I.OxlO2 I.SxIO2 2.0xl02 2.5xl02
r i i i i '
52
A 200 psiy, -- 13.8 x 10 N/m
A
X A
X
x x *
150 psig x
V 7T
* Xx*
_o x x x
0
0 A A
O
100 psig X
O
0 ° 0
X
-
—
o
1 1-1 I n '
.2 .4 .6 .8 1.0 |.
PRESSURE INCREASE,
Figure 7. Pressure gain produced by Dynactor versus
flow rate through it
24
-------
Ul
Table 4. DYNACTOR AIR-MOVING CAPABILITIES: FLOW WITH INLET AND OUTLET OPEN TO
ATMOSPHERE, MAXIMUM PRESSURE GAIN (NO AIR FLOW).
Unobstructed flow
cfm
m /min
m Is
Maximum pressure gain
inch H,0
2 i
nt/m
Spray nozzle pressure
100 psig
(6.9 x 105 N/m2)
640
18.1
0.302
1.0
2.5 x 102
150 psig
(10.4 x 105 N/m2)
780
22.1
0.368
1.5
3.8 x 102
200 psig
(13.8 x 105 N/m2)
880
24.9
0.415
2.0
5.0 x 102
-------
Pressure Current, I
(psig) (amps)
100 13.7, 13.5, 14.0 (average: 13.7)
150 13.7, 13.6, 13.9 (average: 13.7)
200 13.5, 13.6, 13.9 (average: 13.7)
Phase angle measurements were performed by connecting vertical oscillo-
scope trace to measure voltage betveen phases, and horizontal to
measure a small voltage drop between two terminals of the same phase
lead in the switch box, the impedence being purely resistive. Phase
angles of both pump motors were the same and did not vary with pressure.
The resulting Lissajous figure was not a perfect ellipse, indicating
some waveform distortion due to the motor characteristics. The mea-
sured angles between two adjacent phase lines were:
a = 49.6° and /? = 8.2° and since
a = 30° + <0 and ft = 30 - 4>; <0 = 20°,
and thus the total power is
P = s/3 x 207 x 13.7 x COS 20° = 4616 watts - 4.6 kW
POWER CONSUMPTION: DYNACTOR SPRAY NOZZLES
The pumps that drive the Dynactor spray nozzles are both rated at 7 hp
(5.2 kW). By measuring the electrical power consumed, we determined that
the power consumption was about 6.2 hp (4.6 kW) total with the noz-
2
zles at 200 psig (13.8 N/m ) and with them at half that pressure as
well, indicating power consumption was insensitive to nozzle pres-
sures below this value. Because the power used by the system is
related to the kind of motor and pump used, the most basic estimate
of power consumption is to calculate the power, P, expended by the
nozzles, which is the product of the pressure drop across the nozzles,
Ap, and the volume rate of flow of water, 0 . These values are shown
in Figure 8, the flow and pressure data were supplied by the manu-
facturer. (The-values are plotted on a log-log plot because the
26
-------
10
e
'e
TO
60
• FLOW
X POWER
/
1 gal/min
-53
6.31 x 10 mJ/min
1 P s i g
1 hp - .746 kw
till
6.89 x 103 nt/m2
I
I
50 60 70 80 90 100 200
NOZZLE PRESSURE, psig
1.0
K
•5
.3
a
si
o
(X.
t/5
M
Q
-------
applicable fluid flow theory, potential flow, predicts the spray
velocity, thus spray volume flow rate, will be proportional to the
square root of the pressure drop across the nozzle; this is supported
by the data.)
The nozzle power dissipation is given by
p = ^AP (1)
The data supplied by the manufacturer were:
Q =6.6 gal/min at £p • 100 psig
= 4.2 x 10~4m3/sec) (Ap - 6.89 x 105 N/m2)
Q = 8.1 gal/min at AP - 150 psig
= 5.1 x 10~4m3/sec)
-------
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 .
Although 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. We were told
that other models of the device do not use these plastic parts and can
operate at higher temperatures.
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 Ipm flow rate (0.5 cfm), and 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) as generated with the Acrison dust feeder.
Figure 10 gives the same information for the fly ash aerosol. The cut-
off diameters for the impactors were: 13.7, 8.6, 5.6, 4.0, 2.5, 1.3,
0.80, and 0.54 ^m. Conditions such as humidity and feed rate would
be expected to alter the size distributions somewhat for different
tests. The efficiency tests measured the outlet concentration in a
certain size interval versus the inlet concentration in that size
29
-------
TEST NO.
17
19
12
14
X - HEAVY GRAIN LOADING, AMBIENT TEMPERATURE
0 - HEAVY GRAIN LOADING, ELEVATED TEMPERATURE
A - LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
V - LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
99
98
95
90
80
H 70
i 6°
w 5O
n
w
PH
t/D
30
20
10
X
o
o
X
e
x
o
x
r
9
o
X
n — i
8 I 10
8.6
T
.5
T
2
T
3
.54
1.3
2.5
4.0
5.6
AERODYNAMIC DIAMETER, D ,
Figure 9. Inlet size distribution, iron oxide at 1000 cfra (28 m3/Tnin)
30
-------
TEST NO.
21
22
9
10
X - HEAVY GRAIN LOADING, AMBIENT TEMPERATURE
0 - HEAVY GRAIN LOADING, ELEVATED TEMPERATURE
A - LIGHT GRAIN LOADING, AMBIENT TEMPERATURE
V - LIGHT GRAIN LOADING, ELEVATED TEMPERATURE
99
96
93
90
1
w
w
o
80
70
60
SO
40
O
I
e
I
CO
1/3 20
&
f
10
9
2
I
,1
.54
.8
T
1.3
'2 \
2.9
I
3
4.0
5.9
el 10
8.6
AERODYNAMIC DIAMETER, Dn , am
1*7
Figure 10. Inlet size distribution, fly ash at LOOO cfm .28 m /win)
31
-------
interval, thus eliminating most of the effect of variations in inlet
size distribution on collection efficiency.
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
4
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 and the results of
another seven not reported because of various failures during the
experiments, primarily among the first experiments done.
Statistical Analysis of Data
The data analysis was designed through a cooperative effort with GCA,
University of Dayton Research Institute, and the Control Systems group
at EPA. The computer program used to analyze the data was the BMD02V
program from the Biomedical series, 1966 revision (Dixon, 1973).
32
-------
Table 5a. TEST MATRIX, FLY ASH AEROSOL
500 cfm
(14 m3/min)
~ 1 gr/ft3
<~
Heated3
Ambient
1 g/m3)
#7
#8
~ 0.1 gr/£t3
(~ 0,1 g/m3)
#27
#26
1000 cfm
(28 tn3/min)
~ 1 gr/ft3
(~ 1 g/m3)
#22
#21
~ 0.
(~ 0
1 gr/ft3
.1 g/m3)
#10
#9
alnlet air T = 95°C = 200°F
blnlet air T = 21°C - 70°F
33
-------
Table 5b. TEST MATRIX, IRON OXIDE AEROSOL
Heated3
Ambient
b
First stage
Steam added
Surfactant
b
Low spray pressure
500 cfra
(14 m3/min)
~ 1 gr/ft3
(~ 1 g/tn3)
1 "
1 #4
#28, 31
~ 0.1 gr/ft3
(-0.1 g/m3)
#24
#23
1000 cfm
<28 m3/min)
~ 1 gr/ft3
(~ 1 g/m3)
#19
#16,17,18
#25
~ 0.1 gr/ft3
(~ 0.1 g/m3)
#14
#12
#32
#13
1500 cfm
(42 m3/min)
~ 1 gr/ft3
(~ 1 g/m3)
#30
#29
u>
alnlet air T = 95°C
200°F
blnlet air T - 21°C
70°F
-------
The following were treated as independent variables for this analysis:
total concentration (total filter), total impactor sample, impactor
samples on each of stages 4, 5, 6, 7, 8, and impactor final filter.
The efficiencies of each of these eight 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 a comparison with confidence estimate tables
for 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 aerosol
fraction is either the size interval between impactor cutoffs or the
total filter or the sum of the material collected on the impactor, the
latter having somewhat smaller mean sizes than the total filter due to
losses of the very largest particles in the drying sections. The effi-
ciencies for the two different dusts for the total filter and the total
impactor have been presented separately because these would be expected
35
-------
Table 6. SUMMARY OF RESULTS OF 16 COLLECTION
EFFICIENCY TESTS FOR DYNACTOR
(FACTORIAL TEST DESIGN).
Aerosol fraction
Total filter
Iron oxide
Flyash
Total impactor
Iron oxide
Flyash
4.0 - 5.6 |_un
2.5 - 4.0 [in.
1.3 - 2.5 |im
0.8 - 1.3 |im
0.54 - 0.8 p.m
< 0.54 urn
Mean
efficiency
96.04 %
93.11
98.97
93.71
89.81
97.60
99.02
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
16
Estimated
uncertainty3
(±
-------
to have very different median aerodynamic diameters, as seen from the
size distributions shown in Figures 9 and 10. The uncertainty figures
are derived from the uncertainty estimates for a single .test, which
will be explained below.
Tables 7a through 7h 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 7 a through 7h, Table 8, and in Figures 11
and 12 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.
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 mS/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 mVmin (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)
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: Impactor stage #4 , 4.0 - 5.6
GRAND MEAN OF EFFICIENCY TESTS: 99.02
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 mVmin (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C C~ 200°F)
-0.2 g/n3 (0.1 gr/ft3)
~2.0 g/m3 (1.0 gr/ft3)
MEAN
99.21
98 . 82
98.35
99.69
99.29
98.75
98.60
99.43
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(3) (4)
F (1,5)
1.31
15.67
2.54
6.14
4.44
2.30
SIGNIFICANCE LEVEL
(IF > 0. 90)
> .95
> .90
> .90
MEAN SQUARE ERROR: .457
40
-------
Table 7d. RESULTS OF STATISTICAL ANALYSIS OS EFFICIENCY
PARTICLE SIZE FRACTION: Impactor Stage #5 , 2.5 - 4.0 \j.m
GRAND MEAN OF EFFICIENCY TESTS: 98.37
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 n»3/inin (500 cfm)
28.3 m3/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
-0.2 g/m3 (O.L gr/ft3)
-2.0 g/m3 (1.0 gr/ft3)
MEAN
98.75
97.99
97.47
99.26
98.57
98.16
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
2.71
SIGNIFICANCE LEVEL
(IF > 0.90)
> .95
> .99
-
> .95
> .99
-
"
MEAN SQUARE ERROR: 0.221
41
-------
Table 7e. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Impactor stage #6, 1.3 - 2.5
GRAND MEAN OF EFFICIENCY TESTS: 93.00
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 n*3/min (500 cfm)
28.3 mS/min (1000 cfm)
IRON OXIDE
FLY ASH
~ 20°C (~ 70°F)
~ 95°C (~ 200°F)
-0.2 g/n3 (0.1 gr/ft3)
~2.0 g/m3 (1.0 gr/ft3)
MEAN
j
94.82
91.17 ;
92.37
93.62
93.54
92.46
92.59
93.41 1
RESULTS OF F-TEST ANALYSIS OF VARIANCE
EFFECT
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(2) (4)
(D(4)
(D(3)
(I) (2)
F (1.5)
75.80
8.89
6.57
3.86
40.71
25.69
11.55
8.1Q
SIGNIFICANCE LEVEL
(IF > 0.90)
> .99
> .95
> .95
> .99
> .99
> .95
^ .QS
MEAN SQUARE ERROR: 0.703
42
-------
Table 7f. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Itnpactor stage #1, 0.8 - 1.3
GRAND MEAN OF EFFICIENCY TESTS: 75.44
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 m3/min (500 cfm)
28.3 tP/tnin (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
(1) Flow
(2) Dust
(3) Temperature
(4) Concentration
(1)(2)
(D(3)
F (1,5)
3.79
2.45
0.73
0.42
2.45
1.63
SIGNIFICANCE LEVEL
(IF > 0.90)
-
-
-
-
-
MEAN SQUARE ERROR: 270.6
43
-------
Table 7g. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Impactor stage #8 , 0.54 - 0.8
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 mg/in3 (0.1 gr/ft3)
~ 2.0 Big/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 d,5)
0.01
2.50
.13
.02
2.22
SIGNIFICANCE LEVEL
(IF > 0.90)
_
-
-
-
MEAN SQUARE ERROR: 700.9
44
-------
Table 7h. RESULTS OF STATISTICAL ANALYSIS ON EFFICIENCY
PARTICLE SIZE FRACTION: Final filter after impactor, < 0.54
GRAND MEAN OF EFFICIENCY TESTS: 47.38
MARGINAL MEANS
PARAMETER
FLOW
DUST
TEMPERATURE
CONCENTRATION
LEVEL
14.2 mS/min (500 cfm)
28.3 n^/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(3)
F (1,5)
0.26
4.05
1.16
41.62
7.04
4.60
1.83
SIGNIFICANCE LEVEL
(IF > 0.90)
.90
> .99
> .95
> .90
MEAN SQUARE ERROR: 219.0
45
-------
Table 8 . SIGNIFICANCE OF EFFECTS OF FLOW, DUST, TEMPERATURE,
AND CONCENTRATION ON SCRUBBER COLLECTION EFFICIENCY
Aerosol fraction
Total filter
Total impactor
4.0-5. 6 |am
2.5-4.0 (jm
1.3-2.5 urn
0.8-1.3 |am
0.54-0.8 mn
< 0.54 jim
Significance level
Flow
~ 0.90
--
--
> 0.95
> 0.99
~ 0.90
--
--
Dust
> 0.99
> 0.99
> 0.95
> 0.99
> 0.95
--
--
~ 0.90
Temp.
--
> 0.99
--
—
> 0.95
--
--
—
Cone.
> 0.95
> 0.99
> 0.90
> 0.95
~ 0.90
--
--
> 0.99
46
-------
PERCE
EFFICIENCY
0
O
99
98
95
90
80
50
10
O
- f GRAND MEAN
. + ~ 1 gr/ft3
(~ 1 g/m )
" 0 ~ .1 gr/ft3
(~ 0.1 g/ni
»
-
O
-
o
?
:° , ,
-»•
j
( i
O
O
1 1
.
4
1 1.
J 0
-
O
: 8
-
*
I GRAND MEAN
0
+ FLY ASH
O IRON OXIDE
•0 +
1 1 1 1
0.5
1.0
2.0
5.0
10
I
w
Ed
20
50
100
OI254OI 2345
DIAMETER, urn DIAMETER, ^m
Figure 11. Dynactor scrubber collection efficiency versus particle
aerodynamic diameter, effects of loading and dust type
47
-------
99
98
g
w
*• »»
s
H
1 "°
H
a
•j
O
O
90
50
10
O
- J GRANT
_ , 500 c
. (14.i
.
Q 1000
w (28.:
-
-
-
_
-
^
•
J
G
V
?
-of*
1
0 1
) MEAN
:fm« : ;
3
i m /dxi)
( i
cfm
5 m Anin) + ( >
J
O
+
ff
O
1 1 1
-
| +
m
" 1 1.
O
i
o
-
•
i i
,
.
B ^
•f
I
o
J GRAND MEAN
+ 20°C (70°F]
_^ AC f^ f O/1O • 1? '
^ ^1 !F J ^* \ £*\AJ C 4
-^ ^^ -
1
f
1 1 1 1
0.5
1 O
1 .W
2.0
5.0
10
2O
50
OO
23401 2345
DIAJETER, |jm DIAMETER, ^In
Figure 12. Dynactor scrubber collection efficiency versus particle
aerodynamic diameter, effects of flow rate and inlet
temperature
w
P-.
H
U
48
-------
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
efficiency than lower concentrations and this was sta-
tistically significant in most fractions.
The F-test analysis of variance also gave information on the significance
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, e, h 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 |_im aerosol fraction, Table 7e. 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 two
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 7e indicate all these
statements are statistically significant. The flow interactions are
displayed in Figure 13. The explanations of all these interactions
for all the stages would be difficult to make, but an example of one
such explanation would be that the difference in efficiency for the two
dusts is caused by collection mechanisms that increase with increased
residence time, thus being more significant at the lower flow rate than
at the higher.
49
-------
Table 9. DETAILED ANALYSIS OF INTERACTIONS FOR DYNACTOR
EFFICIENCY ON 1.3 - 2.5 jim AEROSOL FRACTION
(STAGE #6)
Efficiencies (N=4)
Concentration (4)
~ 0.1 g/tn
3
~ 1.0 g/m
Dust (2)
Iron oxide
Fly ash
Temperature (3)
20°C
95°C
Concentration (4)
3
~ 0.1 g/m
3
~ 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
50
-------
IOO
2
W
H
U
M
W
§
P"^
8
98
96
94
90
89
Iron oxide
Fly ash
_L
A 20°C
A 95°C
_L
QO.l g/nf
• l. g/m3
_L
m
/min
500
14.2
1000
28.3
500
14.2
1000
28.3
500
14.2
1000
28.3
Figure 13. Collection efficiency, 1.3-2.5 (jim, versus flow for
different dusts, temperatures, and concentrations
-------
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
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 (28 m /min), ~ 1 gr/ft (~ 1 g/m ), at ambient temperature.
Both are given in Table 10. In six of eight 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 (42 m /min)
An 8-point pitot tube traverse was used downstream in 8 inch (0.20 m)
•j
diameter duct and yielded an outlet flow of 1510 cfm (A3 m /min).
Twenty point pitot tube traverse used upstream in 12 inch (0.30 m)
3
diameter duct yielded an inlet flow of 1250 cfm (35 m /min). 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.
52
-------
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 impactor
4.0-5.6 urn
2.5-4.0 urn
1.3-2.5 urn
0.8-1.3 (itn
0.54-0.8 urn
< 0.54 um
Standard deviation estimates
(M.S.E)1/2a
a)
1.29
1.26
0.68
0.47
0.84
8.4 (17.7)C
26.5
14.8
0.59 x range
a)
0.41
1.00
0.18
0.59
0.12
3.7
34.0
11.2
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 (Wilson, 1952).
°Value including a discarded datum, test No.
10 (12.5)
53
-------
An attempt was made to seal leaks in the Dynactor and peripheral ducting,
but it must be assumed that with a static pressure loss greater than
2 inch 1^0 (5 x 10 nt/m ) at the outlet some leakage occured. 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
ratio of the rate of particulate mass flow out of the Dynactor to the
rate of particulate mass flow into the Dynactor.
The results for the tests at 1500 cfm (42 m3/min) and at 1000 cfm
(28 m /min) 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 two (4.0 - 5.6 ^m, 0.54 urn). In
three cases (total impactor, 2.5 to 4.0 urn, 1.3 to 2.5 um) 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),
raising the flow seems not to have decreased the efficiency. Three
efficiencies were lower and three were higher. The data from the
tests at 1000 cfm (28 m3/min) and 1500 cfm (42 m/min) displayed lower
efficiencies for increased flow at 20°C but not at 95°C; at 1000 cfm
(28 m /min), six of six fractions showed higher efficiencies at 21°C
than at 95°C, but at 1500 cfm (42 m /min) six of seven fractions showed
higher efficiencies at 95°C than at 21°C, suggesting an interaction
between the two variables.
Collection Efficiency Tests With Inlet Air Humidified
Efficiency tests were 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
54
-------
Table 11. RESULTS OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
SIMILAR CONDITIONS EXCEPT FOR FLOW RATE (IRON OXIDE,
~ 1 g/m3)
Aerosol fraction
Total filter
Total Impactor
4.0-5.6 nm
2.5-4.0 urn
1.3-2.5 urn
0.8-1.3 urn
0.54-0.8 urn
< 0.54 urn
Test number
21°C (70°F)
1500 cfm
(42 m3/min)
94.8
88.9
> 97.5
97.0
87.1
75.0
< 19.4
--
29
1000 cfm
(28 m3/min)
95.4
93.9
> 99.2
98.5
93.1
83.7
46.4
< 82.5
16,17,18 avg.
95°C
1500 cfm
(42 m3/min)
94.7
93.8
> 98.4
98.6
89.4
83.1
75.8
--
30
200°F)
1000 cfm
(28 m3/min)
94.9
91.7
99.1
97.6
89.9
75.9
--
66.1
19
55
-------
The spray was Introduced downstream from the inlet sampling probes. Two
5 2
4 1511 Sprayco pinjet nozzles operated at 80 psi (5.5 x 10 N/m ) were
used, spraying 0.56 gal/min (3.5 x 10~5 m3/s) into air at 350°F (177°C).
The humidity ratio was determined two ways: by weight change of dessicant
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
dessicant. The ratio, by weight, of water vapor to dry air for test
#28 was 0.032 as determined by dessicant 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 dessicant,
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 dessicant
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 higher humidity ratio the second time, so al-
though we have reported the tests as having two different average
humidity ratios (0.044, 0.076), they may have had nearly the same.
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 interval 1.3 to 2.5 urn, for which the efficiencies without steam
addition are higher than those with added steam. The addition 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.
56
-------
Table 12 . RESULTS OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
SIMILAR CONDITIONS BUT WITH AND WITHOUT STEAM ADDITION
(IRON OXIDE, 500 cfm = 0.24 m3/sec, ~ 1 g/m3)
Aerosol fraction
Total filter
Total impactor
4.0-5.6 Urn
2.5-4.0 nm
1.3-2.5 urn
0.8-1.3 |im
0.54-0.8 ^m
< 0.54 (im
Tests
No steam
#4
96.4
93.9
99.1
98.3
96.0
85.2
--
73.3
#53
91.1
94.3
> 99.2
99.1
97.5
89.3
--
72.0
Avs.
93.8
94.1
> 99.1
98.7
96.8
87.2
--
72.6
Steam added
#28
--
95.4
> 99.3
99.3
95.0
85.7
48.4
< 64.4
#31
96.2
93.0
> 98.9
98.9
94.0
80.3
70.0
< 80.0
Avg.
96.2
94.2
> 99.1
99.1
94.5
83.0
59.2
< 72.2
aThis test done
at 95°C (= 200°F)
57
-------
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
(#17, 18, 16) were run; that is, 1000 cfm (28 m3/min), ~ 1 gr/ft3
3
(~ 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 two fractions there were
no distinguishable differences. In the range 1.3 to 4.0 |am, the
efficiencies were more than one standard deviation apart but less than
two. For most applications, the differences would not be substantial.
Collection Efficiency Tests At Reduced Nozzle Pressure
One efficiency test was made using the Dynactor spray nozzles at 100 psig
5 3
(6.9 x 10 N/m ), 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 (28 m /min) at ~ 0.1 g/m
(~ 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.
58
-------
Table 13 . RESULTS OF DYNACTOR COLLECTION EFFICIENCY TESTS UNDER
SIMILAR CONDITIONS EXCEPT FOR THE ADDITION OF 10 ppm
SURFACTANT TO THE SPRAY WATER
Aerosol fraction
Total filter
Total impactor
4.0-5.6 fim
2.5-4.0 (am
1.3-2.5 jitn
0.8-1.3 \an
0.54-0.8 urn
< 0.54 \m
Test number
Collection efficiencies
Surfactant
added
95.5
94.4
> 99.2
99.2
94.2
84.9
62,2
< 82.2
25
No
surfactant
95.4
93.9
> 99.2
98.5
93.1
83.7
46.4
< 82.2
16,17,18 avg.
59
-------
SECTION VI
DISCUSSION
In this section, we compare the Dynactor Scrubber with a widely-used
control device which also uses the collection of particles by spray
droplets, the venturi scrubber. Costs are compared for the two dif-
ferent scrubbers when used so as to obtain very similar efficiencies.
The effects of the factors studied with the factorial design tests is
discussed as well.
DYNACTOR SCRUBBER VERSUS VENTURI SCRUBBER
Both the typical venturi scrubber and the "ejector venturi" (Harris,
1964) use a fine water spray to clean a gas stream. The latter uses
this spray to supply some of the motive power to the air stream. Fair-
ly similar flow versus pressure gain curves are obtained with the
Dynactor scrubber operating at 200 psig and 18.4 gpm water spray
5 • 2 — 3 3
(13.8 x 10 N/m and 1.17 x 10 m/s) and with the ejector venturi
5 2 -3 3
operating at 40 psig and 24 gpm (2.8 x 10 N/m and 1.53 x 10 m /s),
according to the published data (Harris, 1964), which would mean that
the latter acts as a fan about 4 times more efficiently than does the
Dynactor. The collection efficiency information on the ejector venturi
is sketchy, but at a comparable power consumption by the nozzles in the
o
two systems (2 hp/1000 cfm, 3.2 kw/m /s) the observed mass efficiency
for the ejector venturi (Takishima et al., 1961) was 97.8 percent and
for the Dynactor scrubber 99.0 percent, for fly ash aerosols having
mass median diameters near 6 ^m. Thus the two-stage Dynactor yielded
half the penetration compared to an ejector venturi operating at the
same spray input power per volume flow of air. Much more experience
60
-------
io3
has been gained with the usual venturi scrubber, so that the remainder
of this comparison segment will concern the Dynactor and the conven-
tional venturi scrubber. The prime function of the Dynactor scrubber
is to remove particulate material rather than to aid flow, so the
comparison should be made with venturi scrubbers having the same
collection efficiency. Figure 14 is derived from the Scrubber Handbook
(Calvert et al. , 1972). It gives the theoretical collection efficiency
of venturi scrubbers as a function of the air flow pressure drop pro-
duced by the venturi; these curves match experimental results obtained
with Venturis rather well. From the grand mean mass collection effi-
ciencies measured for the Dynactor we have plotted the interpolated
collection efficiency at 1, 2, and 4 urn aerodynamic diameter to obtain
the pressure .drop associated with a venturi scrubber having the same
collection efficiency. The data indicate that the corresponding
venturi scrubber pressure drop would be about 40-inch H^O or 10 x
2 2
N/m . Using a 40-inch H20 venturi as an equivalent for comparison,
we investigated the question of relative costs. Both devices use
water sprays and thus must consume clean water., dispose of contaminated
water. Both would be expected to have similar maintenance problems.
Power Consumption
The Dynactor power consumption is the power used by the nozzles divided
by the efficiency of the pumps and associated plumbing. The Dynactor
nozzles use a total theoretical power (flow times pressure drop) of
1.6 kw for the 1000 cfm treated by the DY-12-F2. (The slight air flow
pressure drop is negligible.) The venturi scrubber power consumption
is the product of the air flow times the pressure drop, which would be
4.7 kw for 40-inch H20 and 1000 cfm, plus any power other than the air
flow pressure drop used in supplying the water spray. Thus, comparable
Dynactor scrubbers and venturi scrubbers have intrinsic power require-
•ments which are nearly three times lower for the Dynactor.
61
-------
4 2
10 N/m
§
I-H
I
H
W
2
u
OU
1.0
0.9
0.8
0.7
0.6
as
0.4
0.3
0.2
0.5
1.0
1.5
2.0 2.5
3.0
3.5
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.0091-
0.008
0.007
0.0061-
0.005
T I I
1 T
O DYNA.CTOR
DY-12-F2
VENTURI
SCRUBBER
o.oo
O.5O
0.90
CJ
UJ
O.95
O.99
20
120
Figure 14.
40 60 80 100
VENTURJ PRESSURE DROP. A P
Collection efficiency curves for venturi scrubbers
and Dynactor efficiency data
140
62
-------
Water Consumption
The two-stage Dynactor scrubber we tested worked with nozzles having a
-3 3 3
flow of 18.4 gal/min for 1000 cfm or 2.5 x 10 m /s water per 1 m /s
of air.
Cost estimates in the Scrubber Handbook (Calvert et al., 1972) used
3 -33 3
8.4 gal/1000 ft or 1.1 x 10 in water per m air as typical for
venturi scrubbers, which is somewhat less than half that used by the
Dynactor.
The amount of water actually consumed by both systems would depend on
the dust loadings and on their relative abilities to recirculate the
contaminated water.
Costs
Scrubber applications vary, as do the trade-offs made by scrubber
manufacturers in meeting their user's requirements. Any cost compar-
ison has to be used with an awareness of the uncertainties in such
projections, and this one is no exception. The one which follows has
an added difficulty: it is based on two different sources of data,
the open literature on venturi scrubbers and the data supplied by RP
Industries, manufacturers of the Dynactor scrubber.
2
We chose to compare the two types of scrubber at 40,000 cfm (19 m /s),
which is more nearly typical of industrial applications than the 1000
cfm at which the Dynactor DY-12-F2 was tested. The systems were
assumed to be operated 8,000 hours a year, nearly full-time.
Following is an explanation of the information contained in the tables,
63
-------
Estimated Capital Investment - Capital investment is the sum of pur-
chased equipment cost and installation. Venturi installation
was assumed to be 200 percent of the purchased cost, from material in
the Scrubber Handbook (Calvert et al., 1972).
Annual^ Operating Costs - The annual operating cost includes the follow-
ing fixed, variable, and semi-variable costs.
Fixed costs -
1. Amortization of capital investment - The capital invest-
ments have been amortized over a period of 20 years.
This reflects the expected lifetime of the equipment
based upon literature review. (Blecker and Nichols,
1973)
2. Interest on loan - An interest rate of 8 percent of the
total capital investment was used. It was further
assumed that the interest is to be paid after one year,
but is capitalized uniformly over the estimated 20-
year lifetime of the equipment. This method is used in
similar engineering estimates. (NAFCA, 1969)
3. Insurance - The cost of insurance was estimated to be
1.0 percent of total" capital investment. This figure
is suggested by Peters and Timmerhaus (1968) as a
reasonable estimate.
Variable and semi-variable costs -
1. Labor and maintenance - Annual labor and maintenance
was estimated to be 1.4 percent of the installed equip-
ment cost. This represents the lower end of the range
for this type of equipment. (Blecker and Nichols,
1973; Calvert, Goldschmidt, Leith, Mehta, 1972)
2. Electric power - Electric power requirements for the
high energy venturi scrubber were obtained from the
Scrubber Handbook. (Calvert et al., 1972) Power
needed for the Dynactor System was obtained from
manufacturers literature. Power costs were assumed to be
be $0.025 per kilowatt-hour. (Boston Edison rate
schedule, 1974)
64
-------
Water - Water requirements for the Dynactor system
were obtained from manufacturer's literature. Water
needs for the venturi scrubber were obtained from the
Scrubber Handbook. Water costs were assumed to be
$0.50 per 100 cubic feet. (Boston Public Works Dept.,
July 1974)
Table 14a. Estimated capital cost of Dynactor system, based on
manufacturer's data (1973 dollars)
FLOW CAPACITY:
40,000 cfm = 1.13 x 103 m3/min = 18.9 m3/s
TOTAL CAPITAL INVESTMENT $120,000
Purchased Equipment $60,000
Installation $60,000
Estimated Operating Cost of Dynactor System
TOTAL CAPITAL INVESTMENT (C.I.) $120,000
FIXED COST (ANNUAL)
Amortization at 5% C.I. $ 6>000
Interest on Loan (8% of C.I.) • $ 48°
Insurance (1.0% of C.I.) $ 1,200
VARIABLE AND SEMI-VARIABLE COST (ANNUAL)
Labor and Maintenance (1.0% of C.I.) $ 1,200
Electric Power ($0.025/kw.-hr.) $ 11,936
Water ($0.50/100 cubic feet) $ 4»825
Paid in one year; amortized over 20 years.
65
-------
Table 14b. Estimated capital cost of high energy Venturi scrubbers,
yielding similar collection efficiency to Dynactor
(1973 dollars)
FLOW CAPACITY
40,000 cfm = 1.13 x 103 m3/min = 1.89 m3/s
TOTAL CAPITAL INVESTMENT $147,000
Purchased Equipment $49, 000
Installation $98,000
Estimated Operating Cost of High Energy Venturi Scrubber
TOTAL CAPITAL INVESTMENT (C.I.) $147,000
FIXED COST (ANNUAL)
Amortization at 5% C.I. $ 7,350
#%
Interest on Loan (8% of C.I.) $ 588
Insurance (1.07. of C.I.) $ 1,470
VARIABLE AND SEMI-VARIABLE COST (ANNUAL)
Labor and Maintenance (1.0% of C.I.) $ 1,470
Electric Power ($0.025/kw.-hr.) $63,300
Water ($0.50/100 cubic feet) $ 6,420
a Paid in one year; amortized over a 20-year period.
From the material on costs in the foregoing two tables, we conclude that
the primary difference in costs between the Dynactor system and an equiv-
alent venturi scrubber is the difference in electrical power costs, esti-
mated here to be a difference on the order of $50,000/yr for treating
3
40,000 cfm (19 m /s) in favor of the Dynactor, based on $0.025/kw.-hr.
For the 1000 cfm model we tested, the difference in intrinsic power re-
quirements was a factor of three to one in favor of the Dynactor in com-
parison with an equivalent venturi. Using this ratio, the difference
between Dynactor power cost per year and the power cost per year of an
equivalent venturi would be expected to be $42,000 for treating 40,000
cfm. These yearly savings would be about 407, of the capital investment.
66
-------
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., 1972), 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, f°r which settling would become import-
ant. We found somewhat higher collection efficiencies at the lower
flow rate, as did Lancaster and Strauss (1971) in their experiments
with spray scrubbers, using ZnO particles with a number median dia-
meter of 1.0 jam.
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
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, thus the iron oxide would have been less wettable and more difficult
67
-------
for the water droplets to entrap. Lohs (1969) found that making
hydrophobic polystyrene particles into hydrophilic ones, by coating
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 (1972) 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
1.20 (Bird et al., 1960), 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-
ciencies for all the aerosol size fractions. Lancaster and Strauss
(1971) 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
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
and Strauss (1971), among others, reported increased efficiency with
68
-------
increased mass loading. In our tests with the Dynactor, the improve-
ment 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
decrease 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
Lapple and Kamack (1955) 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 (1969) 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
and Pilat (1970) calculated the contribution of diffusiophoresis to
collection by spray droplets and concluded the effect could be dramatic,
increasing for smaller particles and lower gas/droplet relative
velocities. On the other hand, Slinn and Hales (1971) analyzed the
roles played by thermophoresis and diffusiophoresis in the scavenging
of atmospheric aerosols by cloud droplets and concluded that thermo-
phoresis generally predominates.
69
-------
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
M X
thermophoresis _ a
diffusiophoresis 5 R I*,
where
M « "molecular weight" of air,
cl
X = latent heat of evaporation/condensation
R = gas constant
TO,, = 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.
Lancaster and Strauss (1971) tried to separate the effects of these
flux force mechanisms from the effects of particle size increase and
adhesion improvement due to water vapor. They used cold and hot sprays
to scrub water-saturated air and found no improvement with the cold
spray, which would have produced greater condensation upon the spray
droplets and would have produced an enhancing thermophoresis. Lan-
caster 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
70
-------
survey of "flux force/condensation scrubbing," the use of steam with
spray scrubbers, concluded that particle growth probably predominates
over diffusiophoresis as the enhancement mechanism (Calvert et al.,
1973). 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
diffusio-phoresis 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.
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).
71
-------
SECTION VIII
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. Blecker, H.G., and T. M. Nichols. Capital and Operating Costs of
Pollution Control Equipment Modules. Prepared for U. S. Environ-
mental Protection Agency, Office of Research and Monitoring. July
1973.
4. Calvert, S., J. Goldshmid, D. Leith, and N.C. Jhaveri. Feasibility
of Flux Force/Condensation Scrubbing for Fine Particulate Collection.
Control Systems, 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 Per-
formance. J. Air Pollut. Control Assn. 22:529-532. 1972.
7. Dixon, W.J. HMD: Biomedical Computer Programs. U. Calif. Press,
Berkeley. 1973.
8. Harris, L.S. Energy and Efficiency Characteristics of the Ejector
Venturi Scrubber. Presented at the 57th Annual APCA Meeting,
Houston, Texas. Paper 64-35. June 1964.
9. Harris, L.S. Fume Scrubbing With the Ejector Venturi System. Chem.
Engr. Prog. 62:No. 4, 55-59. 1966.
10. Lancaster, B.W., and W. Strauss. A. Study of Steam Injection Into
Wet Scrubbers. Indus. Engr. Chem. Fund. 10:362-369. 1971.
11. Lapple, C.G. and H. J. Kamack. Performance of Wet Dust Scrubbers.
Chem. Eng. Prog. 51:110. 1955
72
-------
12. Lohs, W. Manufacture of Aerosols and Separation of Ultrafine Dusts
in Spray Washers. Staub. 29:No. 2, 43. 1969.
13. National Air Pollution Control Administration. Control Techniques
for Particulate Air Pollutants. U. S. Government, Washington, D.C.
1969.
14. Peters, S. and K. D. Timmerhaus. Plant Design and Economics for
Chemical Engineers. McGraw-Hill, New York. Section Edition. 1968.
15. 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
16. Sparks, L. E. and M. J. Pilat. Effect of Diffusiophoresis on
Particle Collection by Wet Scrubbers. Atmos. Environ. 4:651-660.
1970 .
17. Takashima, Y., W. T. Kyritsis, R. Dennis, and L. Silverman. Waste
Processing Off-gas Scrubber Studies. Proceedings of the Seventh
AEG Air Cleaning Converence. Brookhaven National Laboratory.
'p. 557-579. October 1961.
18. Wilson, E.B. Jr. An Introduction to Scientific Research. McGraw-
Hill, Inc., New York. 1952.
73
-------
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 to 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
A-l
-------
f
»
f
«
H
LIQUID INPUT, 140 TO 200psi
AIR INPUT, LOW VELOCITY, AMBIENT PRESSURE
HIGH VELOCITY, SUB-AMBIENT PRESSURE
SHOWER OF THIN FILMS AND PARTICLES
REACTION COLUMN
GAS OUTPUT
RESERVOIR/SEPARATOR
LIQUID LEVEL DETER-
MINING TRAP
LIQUID OUTPUT
figure A-l.
Single-stage Dynactor diffusion system
cross sectional view
A-2
-------
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.
A-3
-------
DIRTY
GAS
IN
?
*
PLENUM
^)
o
o 5
fll O
2 o
W S3
0 O
<; M
iB
w S
f4 O
M CJ
RESERVOIR
SEPARATOR
PUMP 1
*
PLENUM
*>
M g
Si
^i t?
2 cj
GAS OUT
I
— *.. — . ;
w
2
'S
u
a
Q
RESERVOIR
SEPARATOR
PUMP
t
WATER OUT
MAKE UP WATER IN
Figure A-2. Two-stage Dynactor
-------
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
the balanced 2 factorial design study, as well as tests involving
flow at 1500 cfm (42.5 m3/min), 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
B-l
-------
• Mass efficiency on particles of sizes in that size
interval, based on the preceding two numbers
• 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. For the large end of the particle
size spectrum, 4 pirn and above, the inequalities were calculated with
the assumption that collection efficiency did not decrease as
particle size increased.
B-2
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST if 4
AEROSOL Iron oxide
INLET CONCENTRATION .86 gr/ft3 =1979 mg/m '
OUTLET CONCENTRATION .031 gr/ft3 =71.4 mg/i:J
TOTAL MASS EFFICIENCY .964
FLOW:
TEMPERATURE:
500 ft3/min = 14.2 m3/min
70 °F
21 °C
Total Spray: 18.4 gal/min
= 1.16 x 10 m /sec
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
(ft-Vmin)
1.0
1.0
1.0
1.0
RATE
(m-Vmin)
= .028
= .028
= .028
= .028
DURATION
(rain)
1.
1.
15.
15.
TOTAL
(ft3)
1.0
1.0
15.0
15.0
VOLUME
(V)
= .028
= .028
= .43
= .43
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL III
STAGE
AERODYNAMIC:
DIAMETER
1 £13. 6
2
3
4
5
6
7
8
Final
TOTAL,
8.6 - 13.6
5.6 - 8.6
INLET
CONCENTRATION
< 10.6
OUTLET
CONCENTRATION
(mg/m3)
< -7
< 10.6 ~ .7
41.0 .85
4.0 - 5.6 96.8 .85
2.5 - 4.0 i 247.
1.3 - 2.5 , 495.
0.80 - 1.3 155.
4.1
19.8
23.1
0.54 - 0.80 i < 10.6 11.8
filter £ 0.54
Andersen Irapactor
17.7 4.7
1074.
66.0
FRACTIONAL
MASS
EFFICIENCY
(percent)
>. 99.1
£90-1
> 99.1
99.1
98-3
96.0
85.2
£ o
73.3
93.9
B-3
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST * 5
AEROSOL Iron oxide
INLET CONCENTRATION ~ .8 gr/ftJ =~2000mg/ir
3
OUTLET CONCENTRATION .040 gr/ft = 91.4mg/- "'
TOTAL MASS EFFICIENCY ~ -95
FLOW: 500 ft3/min = 14.2 m3/tnin Total Spray: 18.4
TEMPERATURE: 205 °F = 97 °C
x 10
m
/sec
REMARKS: Size distribution obtained by impactors at 1.0 cfm flow was
interpolated to match sizing intervals for impactors at 0.5 cfra flow.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMP ACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft3/rain)
1.0
1.0
1.0
1.0
RATE
(m-Vmin)
= .028
= .028
DURATION
(min)
1.
1.
- .028 j 15.
= .028
15.
1
TOTAL
(ftj)
1.0
1.0
15.
15.
VOLUME
On-5)
- .028
= .028
= .43
= .43
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR, MODEL LIT
STAGE
1
2
3
4
AERODYNAMIC
DIAMETER
(urn)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
INLET
CONCENTRATION
(mg/m^)
< 3.5
<3.5
26.9
84.8
OUTLET
CONCENTRATION
(mg/m3)
< -7
FRACTIONAL
MASS
EFFICIENCY
(perci n t)
> 99.1
< .7 I > 99.1
< -7
> 99.1
< .7 > 99.1
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 Impactor
205.
1 417.
I
134.
10.6
17.7
898.
1.9 j
10.4 j
14.4
17.9
4.9 ;
49.7 -
99.1
97.5
89.3
< 0.0
72.0
94-3
B-4
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST ;t 1
AEROSOL Fly ash
INLET CONCENTRATION ~ 0.7 gr/ft"
OUTLET CONCENTRATION .0059gr/ft - 13.6mji/"
TOTAL MASS EFFICIENCY ~ .99
3
FLOW: 500 ftJ/min = 14.2 m3/min Total Spray: 18.4 gal/mig 3
0 0 = 1 . 16 x 10 m /sec
TEMPERATURE:
0
200 F
0
95 C
REMARKS: Inlet concentration sampler malfunctioned, so inlet concentra
tion (0.7 gr/ft-3) estimated from other tests.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(f t-Vmin) (m3/min)
1.0 = .028
.5 = .014
1.0 = .028
.5 = .014
DURATION
(tnin)
3.
3.
69.
90.
TOTAL VOLUME
3.0 = .085
1.5 = .043
69. = 1.95
45. - 1.27
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR, >DDEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
VI. \METER
(urn)
£13.6
8.6 - 13.6
5-6 - 8.6
INLET
CONCENTRATION
(tng/m3)
37.7
118.
186.
4.0 - 5.6 | 141.
•>.5 - 4.0 H3.
1 3 - 2.5 ; 82.
0.80 - 1-3 I 21.2
0.54 - 0.80 < 7.1
filter £0. 54 < 7 • l
Andersen Impactor
704.
OUTLET
CONCENTRATION
(mg/m-^)
< .24
< .24
< .24
< .24
.5
3.2
4.0
2.9
4.0
14.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99. 9
> 99-9
> 99.9
> 99.8
99.5
96.1
81.1
< 58.9
< 43.3
97.9
B-5
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 8
AEROSOL Fly ash
INLET CONCENTRATION .90 gr/ft = 2076
OUTLET CONCENTRATION -0067gr/ft3 =15.4«ig/i
TOTAL MASS EFFICIENCY .993
FLOW: 500
TEMPERATURE:
3 3
ft /rain = 14.2 TO /rain Total Spray: 18.4 gal/min
70 °F =
21 °C
= 1.16 x 10 3 m3/sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m^/min)
1.0 = .028
.5 - .014
1.0 = .028
.5 = .014
DURATION
(roin)
2.
3.
OO •
90.
TOTAL VOLUME
(ft3) (in3)
2.0 = .057
1.5 = .043
88. = 2.49
45. =1.37
FRACTIONAL 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 Impactorj
INLET
CONCENTRATION
(rag/m3)
61.2
160.
278.
151.
132.
80.
19.
< 7.0
< 7.0
881.
OUTLET
CONCENTRATION
(mg/m3)
< .2
< .2
< .2
< .2
.5
3.5
4.1
3.0
2.0
13.4
FRACTIONAL
MASS
EFFICIENCY
(percent )
> 99. 9
> 99. 9
> 99.9
> 99.8
99.6
95.6
78.3
< 57.8
< 72.2
98.5
B-6
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #9
AEROSOL Fly Ash
FLOW: 1000 f fVmin =28.3
INLET CONCENTRATION .25 gr/ft =568
OUTLET CONCENTRATION .0015gr/ftJ =3.3 mg/n3
TOTAL MASS EFFICIENCY .994
m /min Total Spray: 18.4 gal/min
_ ti/:__-!rt~J*J
TEMPERATURE: 68 °F = 20 °
= 1. 16 x 10 m /sec
L»
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
(m3/min)
= .057
= .014
= .057
= .014
DURATION
(min)
10.
26.
296.
300.
TOTAL VOLUME
(ft3) (m3)
20. = -57
13. = .37
592. = 16.8
150. = 4.3
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 Irapactor
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. .8
> 99.8
> 99.8
> 99.7
99.3
93.7
74.5
< 50.9
< 10.4
97.0
B-7
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 10
AEROSOL Fly ash
INLET CONCENTRATION 0-17 gr/ff = 396 mg/ir.J
OUTLET CONCENTRATION .0015gr/ft3 = 3.5 tng/«/
TOTAL MASS EFFICIENCY .991
3
FLOW: 1000 ft /min = 28.3 in /min Total Spray: 18.4 gal/mii^ 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 RATE
(ft-* /min) (m3/tnin)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(tnin)
10
20
240
240
TOTAL VOLUME
(ftj) On-*)
20 = .57
10 = .28
480 = 13.6
120 - 3.4
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTQR. 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
0.54 - 0.80
filter £0.54
Andersen Impactor
INLET
CONCENTRATION
(ntg/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
3.45
FRACTIONAL
MASS
EFFICIENCY
(percent )
> 99.6
> 99.6
> 99.6
> 99.4
99.0
92.0
12.5
< 36.1
< 44.4
95.8
B-8
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 12
AEROSOL Iron oxide
INLET CONCENTRATION .244 gr/ft3 = 560 my/rr '
OUTLET CONCENTRATION .0244 gr/ft"' - 56 mg/V >J
TOTAL MASS EFFICIENCY .900
FLOW: 1000 ftJ/min = 28.3m3/min Total Spray: 18.4 gal/min '
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
(ftj/min) (m3/min)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
5
10
50
120
i
TOTAL
(ftj)
10
5
100
60
VOLUME
Cm-1)
.28
.14
= 2.8
= 1.7
FRACTIONAL EFFICIENCY DATA, ANDE'RSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
Cum)
£13.6
8.6 - 13.6
5.6 - 8.6
4.0 - 5.6
2.5 - 4.0
INLET
CONCENTRATION
Cmg/m^)
< 2-1
16.3
34.6
67.1
124.
1.3-2.5 188.
0 . 80 - 1.3 i 146 .
0. 54 - 0.80
25.4
filter $0. 54 < 2.1
Andersen Impactor
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
(pnL)
> 99.0
> 99.0
99.0
98.5
96.9
92.3
85.3
28.5
< 0.0
89.1
B-9
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 13
AEROSOL Iron oxide
INLET CONCENTRATION .33 gr/ft = 747mg/
OUTLET CONCENTRATION .059 gr/ft = 135 ma/
TOTAL MASS EFFICIENCY .818
3 3
FLOW: 1000 ft /rain = 28.3m /min Total Spray: 9.2 gal/min3 3
TEMPERATURE: 80 °F = 27 °C = -58 x 10" m /sec
REMARKS: Nozzles used at 100 p.s.i.g. =6.9 x 105 N/M2
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMP ACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m^/min)
2.0 = .057
.5 = .014
2.0 = .057
.5 = -014
DURATION TOTAL
(rr.in) (ftj)
4.0 8.0
4.0 2.0
40. 80.
40. 20.
VOLUME
.23
.057
= 2.3
.57
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
Gun)
»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)
< 5.3
7.1
33.6
54.8
124.
210.
147.
15.9
< 5.3
599.
j
OUTLET
CONCENTRATION
(mg/m3)
1.6
1.6
2.3
5.3
15.4
45.4
59.
15.9
5.5
152.
FRACTIONAL
MAS?
EFFICIENCY
(pcrct n i )
> 77.5
77.5
93.2
90.3
87.6
78.4
60.0
0.0
< o-o
74.6
B-10
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 14
AEROSOL Iron oxide
INLET CONCENTRATION .118 gr/ft3 = 271 mg/ir 5
OUTLET CONCENTRATION .016 gr/ft3 = 36.6mg/tr3
TOTAL MASS EFFICIENCY .866
FLOW: 1000 ft3/n>in = 28.3 m3/min Total Spray. 18.4 gal/inl?
TEMPERATURE:
203 F =
95 °C
= 1.16 x 10
3 3
tn
/sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (nrVinin)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
4.
4.
40.
40.
TOTAL
(ftj)
8.
2.
80.
20.
VOLUME
OJ)
= .226
= .057
= 2.26
= .566
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
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
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 95.3
. > 95.3
> 95.3
> 95.3
95.3
89.3
76.3
8.1 < 0
< .5
36.0
-
83.3
B-ll
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 16
AEROSOL Iron oxide
FLOW: 1000 ft /rain
TEMPERATURE:
INLET CONCENTRATION 1.01 gr/ft = 2311 mg/tr.
OUTLET CONCENTRATION .047 gr/ft3 = 107
TOTAL MASS EFFICIENCY .954
28.3m3/min Total Spray: 18.4 gal/min3
63 °F
17 °C
- 1.16 x 10
m
/sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMP ACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(f rVmin) (np/min)
2.0 - .057
0.5 = .014
2.0 = .057
0.5 • .014
DURATION
(min)
1.0
2.0
4.5
15.0
TOTAL VOLUME
(ft-0 (ra^)
2.0 = .057
1.0 = .028
9.0 = .255
7.5 = .212
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(jim)
»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)
49.5
70.7
159.
180.
254.
375.
258.
60.1
17.7
1424.
OUTLET
CONCENTRATION
(mg/m3)
< 1-4
< 1.4
< I-4
< 1-4.
4.7
25.4
33.0
17.4
< 1.4
81.5
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99.2
> 99.2
> 99.2
> 99.2
98.1
93.2
87.2
71.0
> 92.0
94.3
B-12
-------
PYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
INLET CONCENTRATION .84 gr/ft =1922
OUTLET CONCENTRATION .042 gr/ft3 = 96 mg/tr3
TEST # 17
AEROSOL iron oxide
TOTAL MASS EFFICIENCY .950
FLOW: 1000 ft3/min = 28.3m3/min Total Spray: 18.4 gal/min
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
(ffVmin) (nvVmin)
2.0 - .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
1.
2.
15.
15.
TOTAL VOLUME
(ft-5) (mj)
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
(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
filter £0.54
Andersen Iirvpactor
INLET
CONCENTRATION
(mg/tn3)
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
2.8
95.2
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99.0
> 99.0
> 99.0
99.0
98.3
93.2
80.9
13.3
< 73.3
92.9
B-13
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 18
AEROSOL Iron oxide
FLOW: 1000ft /rain
TEMPERATURE:
INLET CONCENTRATION .872 gr/ft3 = 1996
OUTLET CONCENTRATION .038 gr/ft3 = 86.6mg/TT<3
TOTAL MASS EFFICIENCY .957
28.3 tn /min Total Spray: 18.4 gal/min
70 °F
21 °C
= 1.16 x 10"3 m3/sec
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
= .057
= .014
= .057
= .014
DURATION
(min)
1.0
2.0
15.0
15.0
TOTAL
2.0
1.0
30.
7.5
VOLUME
(mj)
= .057
= .028
= .85
= .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMFACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
Gin)
»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
(rng/m^)
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)
> 99.3
> 99.3
> 99.3
> 99.3
99.1
93.0
83.1
55.0
< 82.2
94.6
B-14
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 19
AEROSOL Iron oxide
INLET CONCENTRATION .679gr/ft3 = 1553 uig/i/
OUTLET CONCENTRATION .035 gr/f t = 79.1 mg /,r. '
TOTAL MASS EFFICIENCY -949
FLOW: 1000 ft3/min = 28.3 ra3/min Total Spray: 18.4 gal/rain
TEMPERATURE:
203 °F
95 °C
=1.16x10 m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ftj/min) (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
(ftj)
2.0
1.0
28-
7.
VOLUME
(n.^)
= .057
= .028
= .792
= .198
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(pirn)
£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
(tng/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
1 -r
6.6
28.8
40.9
15.6
3.5
98.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 9.9.2
> 99.2
>99.2
> 99.1
' 97.6
89.9
75.9
11.4
< 66.7
91.7
B-15
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 21
AEROSOL Fly ash
INLET CONCENTRATION -955 gr/ft3 -2186
OUTLET CONCENTRATION -Oil gr/ft3 =25.3
TOTAL MASS EFFICIENCY .988
FLOW: 1000 ft3/min - 28.3 m /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 RATE
(ft3/tnin) On^/tnin)
2.0 = .057
0.5 = .014
2.0 = .057
0.5 = .014
DURATION
(min)
3.0
3.0
57.5
60.0
TOTAL VOLUME
(ft-*) (mj)
6.0 = .171
1.5 = .042
115. = 3.25
30. = .84
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR, MODEL III
STAGE
1
2
3
4
5
6
7
8
Final
TOTAL,
AERODYNAMIC
DIAMETER
(lira)
£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/rn^)
40.0
75.4
153-
115.
80.1
73.0
28.3
< 7.1
< 7.1
575.
OUTLET
CONCENTRATION
(mg/m3)
< .4
< .4
< .4
< .4
1.2
6.8
11.0
5.9
1.1
26.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99.8
> 99.8
> 99.8
> 99.7
98.5
90.6
61.3
< 16.7
< 85.0
99.4 .
B-16
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 22
AEROSOL Fly ash
INLET CONCENTRATION 1.30 gr/ft3 = 2984mg/Tr/'
OUTLET CONCENTRATION .012 gr/ft3 = 27.4 mp,/r 3
TOTAL MASS EFFICIENCY .991
FLOW: 1000 ft3/min = 28.3n,3/min Total Spray: 18.4 gal/min
TEMPERATURE: 203 °F = 95 °C = 1>16 x 10" m /sec
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
(m-Vmin)
= .057
= .014
= .057
= .014
DURATION
(min)
3.0
3.0
58.0
60.0
TOTAL
(ftj)
6.0
1.5
116.
30.
VOLUME
0J)
= .171
= .042
= 3.28
= .84
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 Impactor
INLET
CONCENTRATION
(mg/m3)
84.8
155.
229.
127.
115.
80.1
30.6
< 7.1
< 7.1
822.
OUTLET
CONCENTRATION
(mg/m3)
< -4
< -4
< -4
< .4
1.4
9.2
9.2
4.6
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99.8
> 99.8
> 99.8
> 99.7
98.8
88.5
70.0
< 35.0
1.8 < 75.0
26.9
96.7
B-17
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 23
AEROSOL Iron oxide
INLET CONCENTRATION .178 gr/ft3 =408 mg/tr.3
OUTLET CONCENTRATION .010 gr/ft3 = 23.2mg/mJ
TOTAL MASS EFFICIENCY .943
FLOW: 500 ft /min = 14.2 m /min Total Spray: 18.4 gal/min
TEMPERATURE: 66 °F = 19°C = 1.16 x 10" m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ftj/min) (m-Vmln)
1.0 • .028
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
15
15
118
120
TOTAL
(ft3)
15.0
7.5
118
60
VOLUME
(™J)
= .424
= .212
= 3.34
= 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
0.54 - 0.80
filter £0.54
Andersen Impactor
INLET
CONCENTRATION
(rag/in-5)
< 1.4
98.6
> 98.6
> 98. 6
> 98.6
97.8
91.0
76.6
< 0
< 25.0
85.6
B-18
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 24
AEROSOL Iron oxide
INUET CONCENTRATION .187 gr/ft3 = 428
OUTLET CONCENTRATION .014 gr/ft3 =32.6mp/r3
TOTAL MASS EFFICIENCY .924
FLOW: 500 ft /mln =14.2 ra /min Total Spray: 18.4 gal/min
TEMPERATURE:
203 °F
95 °C
= 1.16 x 10 3 m3/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
(nvVmin)
= .028
= .014
= .028
= .014.
DURATION
(min)
15
15
84
120
TOTAL
(ft13)
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
0.54 - 0.80
filter £.0. 54
Andersen Impactor
INLET
CONCENTRATION
(mg/n»3)
2.8
3.3
10.8
16.5
39.6
71.1
56.5
12.7
< 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)
> 93.8
92.9
97.3
97.9
96.3
89.9
82.7
49.1
< 0
86.7
B-19
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 25
AEROSOL Iron oxide
INLET CONCENTRATION .615 gr/f t = 1406ms/jr.'
OUTLET CONCENTRATION .027 gr/ftJ = 62.9mg/rr.3
TOTAL MASS EFFICIENCY .955
3 3
FLOW: 1000 ft /min = 28.3 m /min Total Spray: 18.A gal/min,
TEMPERATURE:
70 °F
21 °C
= 1. 16 x 10 m /
sec
REMARKS: Approximately 10 ppm surfactant added to spray water.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft-Vmin) (m-Vmin)
2.0 = .057
0.5 - .014
2.0 = .057
0.5 - .014
DURATION
(min)
1.
2.
15.
15.
TOTAL VOLUME
(ft^) 99.2
> 99.2
> 99.2
> 99.2
99.2
94.2
84.9
62.2
< 82.2
94.4
B-20
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 26
AEROSOL Fly ash
INLET CONCENTRATION .121 gr/ft3 = 276 mg/m3
OUTLET CONCENTRATION. 002 gr/ft3 = 3.9 mg/m*
TOTAL MASS EFFICIENCY 98.6
FLOW: 500 ft /min = 14.2 m./min Total Spray: 18.4 gal/m^n 3
TEMPERATURE: 85 °F = 29 °C 1.16 x 10 m /sec
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m^/min)
1.0 = .028
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
25.
25.
268.
270.
TOTAL VOLUME
(ft3) (raj)
25.0 = .708
12.5 = .354
268. =7.58
135. =3.82
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTQR. 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 Impactor
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)
> 99.8
> 99.8
> 99.8
> 99.7
> 99.7
96.0
86.7
< 0
< 62.5
97.8
B-21
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #27
AEROSOL Fly Ash
INLET CONCENTRATION .136 gr/ft3 = 311 mg/ir.
FLOW:
TEMPERATURE:
OUTLET CONCENTRATION .002 gr/ft' = 4.2 mg
TOTAL MASS EFFICIENCY .986
500 ft3/min =14.2 m3/min Total Spray: 18.4 gal/rain^ 3
o = 1.16 x 10 m /sec
200 °F =
n3
95 "C
REMARKS:
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft3/tnin)
1.0
0.5
1.0
0.5
RATE
= .028
= .014
= .028
= .014
DURATION
(min)
25
25
243
293
TOTAL
25
12.5
243
146.5
VOLUME
= .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/m3)
10.2
22.9
36.5
24.0
21.2
16.7
11.6
0.54 - 0.80 i 1.7
filter $0.54 < .8
Andersen Inpactor
145
OUTLET
CONCENTRATION
(mg/m3)
< .07
< .07
< .07
< .07
< .07
.58
1.4
.89
.46
3.4
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 99.8
> 99.8
> 99.8
> 99.7
> 99.7
96.5
87.7
47.5
< 45 . 8
97.7
B-22
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 28
AEROSOL IRON OXIDE
(steam)
INLET CONCENTRATION
gr/ftJ -
mg/in
OUTLET CONCENTRATION .021 gr/ft3 =47.8 mg/irJ
TOTAL MASS EFFICIENCY
FLOW: 500 ft3/rain = 14.2 tn3/min Total Spray: 18.4 gal/min
TEMPERATURE:
= 1.16 x 10"3 m3/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
(ft3/min) (in^/min)
Broken = line, si
0.5 = .014
1.0 = .028
0.5 = .014
DURATION
(min)
imple void
2
15
15
TOTAL
(ft-*)
1
15
7.5
VOLUME
(in3-)
=
= .028
= .42
= .21
FRACTIONAL EFFICIENCY DATA. ANDERSEN IMPACTOR, 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
0.54 - 0.80
filter £0.54
Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
67.1
110
216
216
251 j
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
> 99.3
> 99.3
> 99.3
99.3
95.0
85.7
48.4
< 64.4
95.4
B-23
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #29
AEROSOL Iron Oxide
INLET CONCENTRATION .581 gr/ft3 =1329
OUTLET CONCENTRATION .025 gr/ft3 = 57.
TOTAL MASS EFFICIENCY .948
FLOW: 1500 ft3/min = 42.5 m3/min Total Spray: 18.4 gal/min
TEMPERATURE:
70°F
21°C
1.16 x 10"3 m3/sec
REMARKS:
Data corrected for leakage between inlet and outlet.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW RATE
(ft3/min) (m^/min)
1.0 = .028
0.5 = .014
2.0 = .056
0.5 = .014
DURATION
(min)
2
2
TOTAL
(ftj)
2.0
1.0
15 30
15
7.5
VOLUME
OJ)
= .056
= .028
= .85
= .21
FRACTIONAL EFFICIENCY DATA, ANDERSEN IMPACTOR. MODEL III
STAGE
1
2
3-
4
5
6
7
8
Final .
TOTAL,
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
0.54 - 0.80
INLET
CONCENTRATION
(mg/m3)
10.6
28.3
81.3
67.1
134
177
134
< 10.6
Eilter^0.54 < 10.6
Andersen Impactor! 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)
> 97.9
> 97.9
> 97.9
> 97.5
97.0
87.1
75.0
< 19.4
88.9
B-24
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 30
AEROSOL Iron Oxide
INLET CONCENTRATION .571 gr/ft3 = 1306mg/ir?
OUTLET CONCENTRATION .025 gr/ft3 = 57.6mg/m5
TOTAL MASS EFFICIENCY .947
FLOW: 1500 ft3/min = 42.5 ra3/min Total Spray: 18.4 gal/min
TEMPERATURE:
190°F =
88°C
1.16 x 10"3 m3/sec
REMARKS:
Data corrected for leakage between inlet and outlet.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ft3/min)
1.0
0.5
2.0
0.5
RATE
(nwmin)
= .028
= .014
= .056
= .014
DURATION
(min)
2
2
15
15
TOTAL
(ft3)
2.0
1.0
30
7.5
VOLUME
OJ)
= .056
= .028
= .85
= .21
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
0.54 - 0.80
filter £0.54
Andersen Impactor
INLET
CONCENTRATION
(mg/m3)
35.3
63.6
124
106
163
198
148
14.1
< 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)
> 98.7
> 98.7
> 98.7
> 98.6
98.6
89.4
83.1
75.8
-.
93.8
B-25
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST #31
AEROSOL Iron Oxide
(steam)
FLOW:
TEMPERATURE:
INLET CONCENTRATION .504 gr/ft3 = 1153mg/tr '
OUTLET CONCENTRATION .019 gr/ft3 = 44.4 mgAr.''
TOTAL MASS EFFICIENCY .962
3 3
500ft /min = 14.2ra /min Total Spray: 18.4 gal/min
-3 3
=1.16 x 10 m /sec
REMARKS: Spray in inlet duct humidity ratio of approximately .072.
SAMPLING DEVICE
INLET TOTAL FILTER
INLET IMPACTOR
OUTLET TOTAL FILTER
OUTLET IMPACTOR
FLOW
(ftj/min)
1.0
0.5
1.0
0.5
RATE
(m^/min)
- .028
= .014
= .028
= .014
DURATION
(min)
5
5
25
25
TOTAL
TftT
5.0
2.5
25
12.5
VOLUME
= .14
= .07
= .70
= .35
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)
11.8
17.0
41.0
48.1
102
184
90.5
17.0
< 4.2
510
OUTLET
CONCENTRATION
(mg/m3)
< .8
< .8
< .8
< .8
1.1
11.0
17.8
5.1
< .8
35.9
FRACTIONAL
MASS
EFFICIENCY
(percent)
> 98.9
> 98.9
> 98.9
> 98.9
98.9
94.0
80.3
70.0
-
93.0
B-26
-------
DYNACTOR SCRUBBER EFFICIENCY EVALUATION DATA
TEST # 32
AEROSOL Iron Oxide
(1st Stage Test)
FLOW:
TEMPERATURE:
INLET CONCENTRATION .286 gr/ft3 = 654 mg/m*
OUTLET CONCENTRATION
TOTAL MASS EFFICIENCY -
- gr/ft = - mg/n>
3 3
1000 ft /min = 28.3 m /rain Total Spray: 18.4 gal/min
80°F =
27°C
-3 3
= 1.16 x 10 m /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
(ftj/min) (m3/min)
1.0= .028
0.5 = .014
— = —
0.5= .014
DURATION
(min)
3
3
-
10
TOTAL VOLUME
(ftj) (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
(lim)
»13.6
8.6 - 13.6
5.6 - 8.6
INLET
CONCENTRATION
(mg/m3)
14.1
28.3
70.7
4.0 - 5.6 80.1
2.5 - 4.0
127
1.3-2.5 184
0.80 - 1.3
0.54 - 0.80
filter £0.54
Andersen Impactor
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
> 96.0
96.0
92.1
85.0
70.8
70.0
61.4
-
80.1
B-27
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
. REPORT NO.
EPA-650/2-74-083
2.
3. RECIPIENT'S ACCESSION>NO.
. TITLE AND SUBTITLE
Dynactor Scrubber Evaluation
5. REPORT DATE
September 1974
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
Douglas W. Cooper and Daniel P. Anderson
8. PERFORMING ORGANIZATION REPORT NO.
GCA-TR-74-21-G
. PERFORMING ORG \NIZATION NAME AND ADDRESS
GCA Corporation
GCA/Technology Division
Bedford, Massachusetts 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
Final; Through 7/26/74
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT The reporf giV6s results of testing the Dynactor spray scrubber for power
consumption and collection efficiency at three flow rates, two temperatures, and two
dust loading levels, using two dusts. Total filter samplers and cascade impactors
were used upstream and downstream from the collector. Power was determined from
voltage, current, and phase-angle measurements. A factorial design series of tests
at two levels of flow, concentration, temperature, and dust type gave these average
mass efficiencies: 99.0% for 4.0-5.6 jum aerodynamic diameter, 98.4% for 2. 5-4. 0
tim, 93.0% for 1.3-2.5 jum, 75.4% for 0.8-1.3 /jm, 27.4% for 0.54-0.80 jum, and
47.4% for < 0.54 /urn. Higher efficiency was fostered by: lower flow rate, lower
inlet'temperature, and higher mass loading. Power consumption was about one-third
of that expected from a venturi scrubber with equivalent collection efficiency, but
collection efficiency decreased dramatically for fine particles, those smaller than
1
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Scrubbers
Performance Tests
Dust Collectors
Efficiency
Air Pollution Control
Stationary Sources
Dynactor Scrubber
Fine Particulate
Collection Efficiency
Power Consumption
13 B
07A
14 B
13A
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF P,
113
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (»-73)
B-28
------- |