-------
300
250
in
(O
O
a
ro
O
CO
•M
CO
O
CJ
•a
0)
N
to
3
200
150
100
KEY:
O Teflon Felt
O PTFE Laminate
A Experimental Felted Glass
Woven Glass
50
4 6 8 10 12
Air-to-Cloth (ACFM/Ft.2)
Figure 44
Comparison of Four Media for Annuallzed Costs vs. Air-
to-Cloth Ratio Assuming a Five Year Bad
- 77 -
-------
Table 13
Annualized Costs of Control for Fabric Filters
Filter
Woven Glass
Experimental Felted Glass
PTFE Laminate
Teflon Felt
2.9
2.9
2.9
2.9
1 Year
$208,838
289,085
390,243
477,648
2 Years
$171,570
219,099
279,013
330,760
Bag Life
3 Years
$159,138
195,719
241,857
281,704
4 Years
$152,950
184,099
223,391
257,330
5 Years
$149,226
177,113
212,261
242,644
00
Woven Glass
Experimental Felted Glass
PTFE Laminate
Teflon Felt
5.8
5.8
5.8
5.8
123,237
163,368
213,954
257,642
104,617
128,368
158,332
184,212
98,387
116,692
139,754
159,684
95,293
110,882
130,514
147,490
93,431
107,382
124,956
140,140
Woven Glass
Experimental Felted Glass
PTFE Laminate
Teflon Felt
8.9
8.9
8.9
8.9
111,804
138,562
172,277
201 ,407
99,386
115,224
135,205
152,449
95,242
107,440
122,815
136,097
93,184
103,562
116,655
127,977
91,938
101,238
112,945
123,077
Woven Glass
Experimental Felted Glass
PTFE Laminate
Teflon Felt
11.3
11.3
11.3
11.3
109,402
130,806
157,789
181,088
99,476
112,144
128,123
141,927
96,158
105,914
118,211
128.837
94,506
102,820
113,283
122,341
93,512
100,944
110,329
118,421
-------
For a prectpttator with an efficiency of 98.5%, the costs are
$151,371, or $1.08/ACFM. For a 99% efficient wet scrubber the costs
are $347,681, or $2.48/ACFM.
Comparing the annualized costs of control for these methods, as
in Figure 45, wet scrubbing is again the most expensive except in
the cases of the PTFE laminate and the Teflon felt filters with a
one-year bag life at an air-to-cloth ratio of 2.9/1. Electrostatic
precipitation is the less expensive method when compared with fabric
filtration at an air-to-cloth ratio of 2.9/1. However, at an air-to-
cloth ratio of 5.8/1 or greater, fabric filtration with woven glass
bags (with bag life of one year or greater) has lower annualized
costs than electrostatic precipitation. By examining Table 13, it
can be seen that other bags with varying air-to-cloth ratios and
bag life will also have lower annualized costs than an electrostatic
precipitator at $151,371 per year.
- 79 -
-------
350
99%
300 -
250
in
re
en
o
^ 200
o
o
«*-
o
V)
4->
I/)
o
01
150
•~ 100
50
99.8%
99.8%
<0
i— O>
> to
O 01
en
01
u. o>
«o
c co
o
C «0
01 01
CO
98.5%
Fabric
Filtration
(A/C 5.8/1)
Electrostatic Wet
Precipitation Scrubbing
Figure 45
Annual1zed Cost for the Three A1r Pollution Control Techniques
- 80 -
-------
DISCUSSION
The performance of the pilot plant Indicated that high levels
of dust removal efficiency could be obtained. All three filter
medias tested exceeded the dust removal requirements of both the
State of Tennessee and the Federal codes.
Dew point excursions and sub-dew point operation prohibited
attainment of meaningful pressure drop data. For this reason no
conclusions regarding the commercial suitability of pressure drop
levels during normal operation were made.
As might be expected, sub-dew point operation resulted in a
high degree of corrosion, thus a great deal of maintenance and
replacement of mechanical parts were required. This was particu-
larly notable in the case of the cleaning system dampers and the
cylinder and valves associated with these dampers.
As shown in the economic analysis, the wet scrubber does not
compare well with the electrostatic precipitator or fabric filters
in terms of operating and annualized costs. In comparing the
electrostatic precipitator with the fabric filter, with respect to
capital costs, the fabric filter is lower for all bags considered;
with respect to operating costs, the electrostatic precipitator is
generally lower.
In terms of annualized costs, the least expensive filter media
studied (woven glass, 23 oz.) at an air-to-cloth ratio of 5.8/1 or
greater shows a lower annualized cost than the electrostatic precip-
itator,
case with the most expensive filter media (Teflon) where It turns
out the electrostatic precipitator looks economically more attrac-
tive except in the cases where Teflon felt can achieve three to five
- 81 -
-------
year bag life for atr-to-cloth ratios of 5.8/1 through 8.9/1.
Since this cost analysis shows the electrostatic and fabric
filter fairly close to each other, the empirical data showing bag
life and operating pressure drop are of critical Importance 1n
furthering this analysis and allowing one to determine which of
the two generic types is the better dust removal alternative for
this particular application.
- 82 -
-------
Appendices
Appendix page
A-l Comparison of Physical Properties 84
of New and Exposed Fabrics
A-2 NTTC Ash Procedures for Analysis and 89
Results of Analysis
A-3 Experimental Felted Glass Fabric - 92
November 1976 Results
A-4 Particle Size Distribution Data, 101
Brinks and Andersen
A-5 Fractional Loading Data 105
A-6 Compilation of Andersen Run Data 109
A-7 Statistical Analysis of Outlet Loading 111
and Air-to-Cloth Ratios
A-8 Sample Cost Calculations for Fabric 115
Filters, Electrostatis Precipitators
and Wet Scrubbers
- 83 -
-------
Appendix A-l
Comparison of Physical Properties
of
New and Exposed Fabrics
- 84 -
-------
Table A-1
Physical Properties
Experimental Felted Glass
New Fabric Exposed
Fabric at NTTC
Machine Direction
breaking strength 527 452.5
(Ib/inch)
Cross Machine Direction
breaking strength 448 419.5
(Ib/inch)
% Elongation 9.6 9.7
Air Permeability
(CFM/Sq. Ft. 0
1/2"H20) 28 20
Mullen Burst „ ,nn .
(Ib./Sq. inch) 400 + * 400 +
# equipment reads up to 400 Ib./Sq. inch
- 85 -
-------
Table A-l
(continued)
Woven Glass
Fiber Content Glass
Weave 3 x 1 twill
Count 46 x 23
Yarn System 2 ply nlultlfilament
(warp)
Yarn System 3 ply textuHzed + 1
ply multlfilament (fill)
Fabric Exposed New
At NTTC Fabric
Weight As received 2873
Ounces/Sq. Yard Cleaned 22.8 22.5
Permeability As received 3.9-4.4
CFM/Sq. Ft. 0 Cleaned 25.5-27.0 25
1/2 H20
Grab Warp 800 800-850
Strength Filling450 440-480
Mullen Burst
Ibs./sq. Inch 820 800+
M. I. T. Flex
Cycles,(below in 094 up to
100 considered '*™ 15 % Loss
Flex failure)
P. H. Text 5.0
Ignition Loss 4.4 %
- 86 -
-------
Table A-1
(continued)
Teflon Woven
XT-0954 New XT-0954
Property Exposed Sample Typical
1" Ravel Strip
Tensile - ASTM D1682 - WxF 120 x 85 120 x 100
Bursting Strength - ASTM D751
Diaphragm (Mullen) 280 psi 280 psi
Frazier Porosity
ASTM D737 30 20-40
The results show no loss of physical properties as a result of
exposure to the conditions at Nashville Thermal.
- 87 -
-------
TABLE A-l (cont.)
PROPERTIES OF TREATED NOMEX® FELT
EXPOSED 4 MONTHS IN INCINERATOR GAS STREAM
Basis Weight, oz./yd.2
Thickness
1" Strip Tensiles (MD/XD)
Breaking Str., lbs./in.
Elongation, %
Work-to-Break, lbs./in.
Mullen Burst, lbs./in.2
Physical Properties
New
19.2
78
131/100
66/77
54/43.5
388
4 Mo. Exposure
20.2
50
76/57
13/13
6/5
302
- 88 -
-------
Appendix A-2
NTTC Ash:
Procedures for Analysis
and
Results of Analysis
- 89 -
-------
Procedure for Analysis of Ash
from Nashville Thermal
1. Dry approximately 300 grams of ash overnight at 70° C.
2. Weigh 5 grams of dried ash and mix with 40 ml distilled water for
eight hours.
3. Filter above mixture through a millipore filter.
4. Dry millipore filter and residue overnight at 70° C.
5. Calculate Percent Water Soluble.
6. At the same time that item (2) is initiated, weigh 250 grams of dried
ash and mix for eight hours with 2000 ml distilled water.
7. Filter sample on glass fiber filter.
8. Wash with 1000 ml of distilled water and filter again.
9. Repeat item (8).
10. Filter solution from (7), (8), & (9) through millipore filter.
11. Perform following analysis on filtrate:
pH Potassium
Alkalinity COD
Hardness Nitrate
Calcium Phosphate
Iron Zinc
Sulfate Lead
Chloride Total Dissolved Solids
Sodium
- 90 -
-------
Table A-2
Analysis of NTTC Ash
January 6, 1977
Sample Designation
Sample Number
% Water Soluble
Analysis of Filtrate
PH
Alkalinity mg/1 as CaCOa
Hardness mg/1 as CaCOa
COD mg/1
Total Dissolved Solids mg/1
Total Phosphate mg/1 as P
Sul fates mg/1
Calcium, mg/1
Potassium, mg/1
Sodium, mg/1
Chloride, mg/1
Fluorides, mg/1
Lead, mg/1
Zinc, mg/1
Nitrates, mg/1
Iron, mg/1
Fly Ash
3382
13.4
10.5
50
2038
38
9122
0.1
1149
843
700
1339
4120
2.32
0.31
0.04
2.45
0.06
Cinder Ash
3383
1.1
12.0
760
706
172
1108
0.35
37
370
47
83
117
1.16
0.48
0.16
1.56
0.04
- 91 -
-------
Appendix A-3
Experimental Felted Glass Fabric
November 1976 Results
- 92 -
-------
Experimental Felted Glass Fabric
November 1976 Results
Figures A-3a thru A-3c, pressure drop vs. time curves, Indicate
that the fabric does have some self-cleaning tendencies and will
operate at acceptable pressure drop levels for the air-to-cloth
ratios studied. These self-cleaning tendencies were not seen in the
April tests, Jue probably to less frequent readings. Another obser-
vation is that the pressure drop at lower air-to-cloth ratios
remained as low (0.3" W.G.) during testing with no reverse-air
cleaning as during reverse-air employment. This is demonstrated in
Figure A-3d.
An Andersen sampler was used to obtain in-situ particle size
data for the air-to-cloth ratios of 4.2, 6 and 9.4 Inlet flue gas
volumes ranged from 1970 ACFM to 2914 ACFM. Test periods lasted up
to two (2) hours with the reverse-air fan off. No testing was
conducted during periods of boiler upset.
Figure A-3e shows the particle size distribution for air-to-
cloth ratios of 4.2, 6 and 9.4. In ascending order of air-to-cloth
the percentage of particulate matter less than three (3) microns is
88%, 54% and 47% respectively. From the graph, it appears that
bags with the A/C of 4.2 release the smallest percentage of particles
larger than three (3) microns. At the inlet, however, 74% of the
total particulate entering was larger than three (3) microns.
The mass mean particle diameters at the outlet for A/C ratios of
4.2, 6-and 9.4 are 0.71 micron, 1.98 microns and 3.45 microns respec-
tively, and are smaller than those found in the April tests. Average
outlet concentrations and relative cumulative percentages are given
in Table A-3. Based on the most current Inlet particulate concentra-
tiontion of 0.538 grains/SCFD, the fractional efficiencies of the
experimental felted glass fabric in the Enviro-Systems & Research
baghouse 1n Increasing A/C ratios are 98.6%, 99.8% and 99.2%.
- 93 -
-------
vo
I
6
5
4
CONDITIONS:
NO REVERSE-AIR CLEANING
0 10 20 30 40 50 60 70 80 90 100 110 120
Elapsed Ttme - Minutes
Figure A-3a
Experimental Felted Glass Bags — Pressure Drop vs. Time for A/C - 6.04/1
-------
vo
tn
8
CD
V)
o
V)
CONDITIONS:
NO REVERSE-AIR CLEANING
10 20 30 40 50 60 70 80 90 100 110 120
Elapsed Time -* Minutes
Ftaure A-3b
Experimental Felted Glass Bags — Pressure Drop vs. Time for A/C = 9.4/1
-------
V)
HI
o
0)
wl
V)
(A
O
-------
8
o
a
a>
KEY:
O Start 2 Hr. Test
(RA Off)
D End 2 Hr. Test
(RA Off)
O After Cleaning Cycles
. Initiated for 30 Minutes
(Cleaning Cycle—7 seconds
Cleaning Each Cell Every
120 Seconds)
12345678S
Air-to-Cloth (ACFM/Ft.2)
Figure A-3d
Pressure Drop vs. Air-to-Cloth Ratio for Experimental
Felted Glass Bags'
- 97 -
-------
9.0
8.0
7.0
6.0
5.0
4.0
S 3.0
•r-
•k
0)
N
i- on
t/l fc • U
01
«O
O.
1.0
.9
.8
.7
.6
.5
.4
I
I I
I
I
I
I
I
10 20 30 40 50 60 70 80 90 95
% Less Than Size Indicated
Figure A-3e
Outlet Particle Size Distribution
Experimental Felted Glass Bags
98
- 98 -
-------
.008
.007
.006
in
c
f
to
CD
.005
.004
to
•M
0)
U
.003
* .002
.001
j L
2 3456789
Air-to-Cloth Ratio (ACFM/Ft.2)
Figure A-3f
Outlet Concentration vs. A1r-to-C1oth Ratto for
Experimental Felted Glass Bags - N6v. Test
10
- 99 -
-------
Table A-3
Outlet
Concentration and Cumulative %
Experimental Felted Glass
A1r-to-Cloth 4.2/1
Avg. (1) Avg. (2)
Part. Outlet
01am. Cone.
Microns gr/SCFD
11.1
7.5
5.1
3.3
1.7
1.0
0.71
<0.71
0.000649
0.000145
0.000125
0.000149
0.0000565
0.000785
0.00191
0.00353
Cum
100.
91.
89.
87.
85.
84.
74.
48.
Bags
A1r-to-Cloth 6/1
% (3)
00%
16
19
49
46
69
01
03 <
Avg.
Part.
01 am.
Microns
8.8
6.0
4.1
2.6
1.3
0.8
0.6
0.6
TOTAL 0.0073495
(1)
(2
(3
Avg.
Outlet
Cone.
gr/SCFD
0.000340
0.0000359
0.0000384
0.0000564
0.0000205
0.0000384
0.0000513
0.000298
0.0008751
Cum
100.
61.
57.
53.
46.
44.
39.
34.
%
00%
58
48
09
64
3
9
05
Corrected for Stack Temperature
gr/SCFD - Grains Per Standard Cubic Foot Dry (Standard - 70 F,
Percent of Total Outlet Concentration Less Than Size Indicated
Air-to-Cloth 9.4/1
Avg.
Part.
01 am.
Microns
9.1
6.2
4.2
2.7
1.4
0.9
0.6
<0.6
29.92" Hg)
Avg.
Outlet
Cone.
gr/SCFD
0.000117
0.0000717
0.0000345
0.0000173
0.0000619
0.0000272
0.0000173
0.0000593
0.000404
Cum
100
71
53
45
40
25
18
14
%
.00%
.3
.61
.1
.84
.6
.9
.6
-------
Appendix A-4
Particle Size Distribution Data
Brinks Impactor - Inlet
Anderson Impactor - Outlet
- 101 -
-------
Table A-4
o
ro
Brinks Inlet Particle Size Distribution
3/22/77
Precutter
Stage 1
Stage 2
Stage 3
Stage 4
Stage 5
Stage 6
Run 1
DSO
Lower Size Limit
(Microns)
19.23
11.69
6.64
3.95
2.71
1.46
0.95
%
Cumulative
100.00
24.53
21.63
16.76
12.04
11.58
8.69
Run 2
D50
Lower Size Limit
(Microns)
20.09
12.22
6.95
4.13
2.84
1.53
1.00
%
Cumulative
34.04
30.68
19.27
16.69
14.98
12.08
9.17
-------
Table A-4
Particle Size Distribution for Andersen Sets
o
CO
RA 4-11
RA 8
RA 6
RA 7
RA 3
RA 5
TOTAL
AVG
RA 2-11
RA 1-11
RA 1
RA 3-11
RA 4-9
RA 5-9
TOTAL
AVG
A/C
Ratio
3.2
3.2
6.4
6.4
8.7
8.7
4.4
4.4
4.8
5.4
6
6
Experimental Felted Glass
Particle Size Distribution (Microns)
Stage #
#1
8.5
9.5
7.8
9.6
9.4
9.4
54.2
9.33
#2
5.7
6.5
5.3
6.5
6.7
6.7
37.4
6.23
#3
3.9
4.3
3.6
4.4
4.5
4.5
25.2
4.2
#4
2.5
2.9
2.3
2.9
3.0
3.0
16.6
2.77
#5
1.2
1.4
1.2
1.4
1.4
1.4
8.0
1.33
#6
0.73
0.83
0.7
0.86
0.9
4.02
.804
#7
0.46
0.59
0.5
0.59
0.59
2.78
.556
#8
0.20
0.31
0.33
0.37
1.21
.3025
#9
0.20
0.31
0.33
0.37
1.30
.325
PTFE Laminate
8.4
8.4
8.4
8.4
8.4
8.4
50.4
8.4
5.7
5.7
5.6
5.7
5.7
5.7
34.1
5.7
3.9
3.9
3.9
3.9
3.9
3.9
23.4
3.9
2.5
2.5
2.5
2.5
2.5
2.5
15.0
2.5
1.2
1.2
1.2
1.2
1.2
1.2
7.2
1.2
0.77
0.77
__
0.77
0.77
0.77
3.85
0.77
0.52
0.52
0.5
0.52
0.26
--
2.32
0.46
__
0.19
• _
0.49
__
0.56
1.24
0.41
_ _
0.19
— —
0.49
_ _
0.56
1.24
.41
-------
. .• A/r
And. A/C
Table A-4 (continued)
Woven Glass
Particle Size Distribution (Microns)
Stage I
— a -
Run # Ratio Jl J£_ #3 14 Jf5_ _#6_ _#7_ _#8_ _J9_
RA 8-11 2.75
RA 2 2.75
RA 4 4.1
RA 5-11 4.2
RA 6-11 6.7
RA 7-11 6.7
TOTAL
AVG
8.8
8.0
8.6
8.0
9.8
9.9
53.1
8.85
6
5
5
5
6
_6
36
6
.0
.5
.8
.5
.7
.7
.2
.033
4.1
3.7
4.0
3.7
4.5
4.6
24.6
4.1
2
2
2
2
2
_!
15
2
.6
.4
.6
.4
.9
.9
.8
.63
1.3
1.2
1.3
1.2
1.5
1.5
8.0
1.33
—
0.8
0.8
0.8
0.9
0.9
4.2
.84
—
0.5
0.5
0.5
0.6
0.6
2.7
.54
-
0.
-
0.
0.
-
~oT
0.
-
5
-
18
16
•I^W
34
17
—
--
0.18
0.16
•^•^VM^H^HH
0.34
0.17
-------
Appendix A-5
Fractional Loading Data
- 105 -
-------
Table A-5
And. Run#
I
o
Fractional Loading For Andersen Sets****
Experimental Felted Glass
Air-to-Cloth 3.2/1
RA 4-11* RA 8** AVG
Air-to-Cloth 6.4/1
RA 6 RA 7 AVG
Air-to-Cloth 8.7/1
RA 3 RA 5*** AVG
Stage #1
Stage #2
Stage #3
Stage #4
Stage #5
Stage #6
Stage #7
Stage #8
Stage #9
TOTAL
.0001303
.0000519
.0000402
.0000593
.0000350
.0000445
.0000434
.0000455
.0000582
.0005083
.0002365
.0000794
.0000379
.0000325
.0001137
.0000126
0
0
.0000382
.0005508
.0001834
.0000657
.0000391
.0000459
.0000744
.0000286
.0000434
.0000455
.0000482
.0005742
.0000864
.0000160
.0000267
.0000203
.0000160
.0000256
.0000107
.0000128
.0000309
.0002454
.0002676
.0000843
.0000917
.0000211
.0000147
.0000348
.0000202
.0000183
.0000678
.0006205
.0001770
.0000502
.0000592
.0000207
.0000154
.0000302
.0000155
.0000156
.0000494
.0004332
.0007071
.0002528
.0001985
.0001250
.0000735
.0000720
.0000338
.0000485
.0001073
.0016185
.0003176
.0002416
.0002339
.0001208
.0000963
.0000673
0
0
0
.0011315
.0005394
.0002472
.0002162
.0001229
.0000849
.0000697
.0000338
.0000485
.0001073
.0014699
**
***
Weighings of the first four substrates based on weight after heavy rust-like particles (not
Impacted on the substrate, rather loose on foil) were removed; last five substrates did not
have this problem.
Weighings of first six substrates also dealt with removal of rust-Uke particles; last three
substrates weights were average of before and after loose particle removal.
Last three substrates contained rust particles and were wet at weighing, so were not included
as representative results (.81mg, 32.97mg and 78.75mg were weights)
Grains/SCFD
-------
Table A-5 (continued)
o
-•J
And. Run#
Stage n
Stage #2
Stage #3
Stage #4
Stage #5
Stage #6
Stage #7
Stage #8
Stage #9
TOTAL
Fractional Loading For Andersen Sets *****
Woven Glass
Air-to-Cloth =2.
RA 2*
.0004359
.0001894
.0000665
.0000794
.0000579
.0000493
.0000515
.0000493
0
RA 8-11**
.00002532
.00001052
.0000597Q
.00004550
.00002560
.00003690
0
0
0
75
AVG
.0003446
.0001473
.0000631
.0000625
.0000417
.0000431
.0000515
.0000493
0
A1r-to-Cloth =4.
RA 4***
.0001281
.0000534
.0000240
.0000373
.0000400
.0000160
.0000080
0
0
RA 5-11
.0002592
.0000759
.0000832
.0000864
.0000801
.0000957
.0000884
.0001009
.0000843
2
AVG
.0001936
.0000647
.0000536
.0000618
.0000601
.0000558
.0000482
.0001009
.0000843
Air-to-Cloth =6.
RA 6-11
.0001100
.0000722
.0000591
.0000673
.0000575
.0001150
.0001314
.0001823
.0002563
7
RA 7-11**** AVG
.0000538
.0000107
.0000230
.0000338
.0000338
.0000507
.0000954
.0004342
0
.0000819
.0000415
.0000411
.0000506
.0000456
.0000828
.0001134
.0002527
.0025630
.0009792 .0005264 .0008031 .0003068 .0009541 .0007230 .0010511 .0006243 .0009659
* 110.88mg recorded for substrate 9--not representative, so not used.
** Recorded weights for substrates 7, 8, & 9 were 0.93, 6.65, 56.97 mg—these were not deemed
representative and were not used.
*** Recorded weights for substrates 8 & 9 are 0.01 and 214.63 mg—these were not deemed
representative and were not used.
**** Even after three hours of oven drying substrates 8 (2.1 mg) and 9 (450.05 mg) were not
deemed representative and were not used.
Grains/SCFD
-------
Table A-5 (continued)
o
00
Fractional Loading For Andersen Sets1
PTFE
A1r-to-Cloth=4.20
And. Run*
Stage #1
Stage #2
Stage #3
Stage #4
Stage #5
Stage #6
Stage #7
Stage #8
Stage #9
TOTAL
RA 1-11
.0002768
.0000359
.0000858
.0000387
.0000498
.0000913
.0000581
.0000276
.0000304
.0006945
RA 2-11*
.0000751
.0000111
.0000166
.0000361
.0000834
.0000361
0
.0000166
.0000500
.0003250
AVG
.0001760
.0000235
.0000512
.0000374
.0000666
.0000637
.0000581
.0000221
.0000402
.0005388
Laminate
A/C=5.4
RA 3-11
.0006280
.0000961
.0002230
.0000564
.0000423
.0000333
.0000179
.0000179
.0000230
.0067270
A/C=4.8
RA 1**
.0000463
.0000628
.0000194
.0000269
.0000284
0
.0000209
0
.0000119
.0002166
A1r-to-Cloth=6
RA 4-9
.0001683
.0000721
.0000400
.0000587
.0000347
.0000614
.0000374
.0000374
.0000552
.0005652
RA 5-9***
.0001722
.0000488
.0000976
.0000334
.0000154
.0000077
0
.0000051
.0000411
.0004213
AVG
.0001703
.0000605
.0000688
.0000461
.0000251
.0000346
.0000374
.0000213
.0000482
.0005123
* Zero weight gain was recorded for 7th substrate
** Substrates six and eight lost weight; therefore, no average of substrates was computed.
*** Slightly negative numbers were recorded for substrate six; these losses could be due to
loss of part of the foil wrappings for the filters or perhaps the filter was slightly
damp at time of weighing.
**** Gra1ns/SCFD
-------
Appendix A-6
Compilation of Andersen Run Data
- 109 -
-------
Table A-6
Andersen Runs (NTT)
Date
of
Run
3/7/77
3/8/77
3/9/77
3/9/77
3/18/77
3/19/77
3/22/77
3/23/77
3/23/77
3/24/77
3/24/77
3/24/77
3/31/77
4/1/77
4/1/77
4/1/77
4/1/77
Type
of
Bag
PTFE Laminate
PTFE Laminate
PTFE Laminate
PTFE Laminate
PTFE Laminate
PTFE Laminate
Woven Glass
Woven Glass
Woven Glass
Woven Glass
Woven Glass
Woven Glass
Experimental Felted Glass
Experimental Felted Glass
Experimental Felted Glass
Experimental Felted Glass
Experimental Felted Glass
A/C
6.3/1
6.3/1
4.4/1
4.4/1
5.4/1
4.8/1
4.1/1
2.75/1
2.75/1
6.7/1
4.2/1
6.7/1
8.7/1
6.4/1
6.4/1
3.2/1
3.2/1
Temp.
Stack
70 F.
70 F.
70 F.
70 F.
62 F.
50 F.
118 F.
165 F.
167 F.
150 F.
165 F.
149 F.
149 F.
115 F.
114 F.
85 F.
87 F.
Grains/
ACF
0.000553
0.000417
0.000670
0.000315
0.000625
0.000212
0.000311
0.000525
0.000916
0.000108
0.000938
0.000615
0.001590
0.000237
0.000640
0.000656
0.000610
Grains/
DSCF
0.000565
0.000422
0.000694
0.000326
0.000673
0.000217
0.000299
0.000526
0.000960
0.001050
0.000955
0.000625
0.001620
0.000245
0.000641
0.000671
0.000595
Mass
Mass
Efficiency Efficiency
(.538)*
99.89
99.92
99.87
99.94
99.87
99.96
99.94
99.90
99.82
99.80
99.82
99.88
99.69
99.95
99.88
99.88
99.89
(.329)* *
99.82
99.87
99.79
99.90
99.80
99.93
99.91
99.84
99.71
99.68
99.71
99.81
99.51
99.93
99.81
99.80
99.82
*Inlet loading 1n grains/DSCF at old port
**Inlet loading 1n grains/DSCF at new port
-------
Appendix A-7
Statistical Analysis
of
Outlet Loading and Air-to-Cloth Ratios
- Ill -
-------
Statistical Analysis
A statistical analysis was conducted to determine if there was
significant relationship between outlet loading and air-to-cloth
(A/C) ratio (velocity through the filtering media). This analysis
was done in four parts. First, an overall correlation coefficient
between grain loading bodies and A/C was developed. Second* a corre-
lation coefficient between grain loading bodies and A/C at separate
filtering media was determined. Third, separate correlation coefi- .
cients between grain loading and A/C for the two hour and four-hour
data were calculated. Lastly, a fitting of a model relating grain
loading to A/C with filtering media included in the model or a
qualitative model was created.
Overall Correlation Coefficient
This was the calculation of the correlation coefficient between
air-to-cloth (A/C) and loading, using grains/SCFD, Ignoring filtering
media and length of run. The correlation coefficient is 0.34096
which is significant at the 0.18 level. Although 1t could be argued
that 0.18 is close to being statistically significant, this correla-
tion is fairly inconclusive. It simply means that there 1s little
linear association between A/C and grain loading across the other
variables. This does not Indicate a low level of confidence in the
data, merely a lack of clear association between the variable A/C
and loading.
Correlation at the Separate Filtering Media
The correlation for the PTFE laminate fabric is 0.1463. Since
1t would be significant at the 0.782 level, it clearly shows no
linier association. These calculations were based primarily on
two (2) hour runs, so the PTFE laminate fabric should not be con-
demned completely.
- 112 -
-------
The woven glass fabric yielded a correlation of 0.1989 which,
again, is not significant.
The felted glass media gave a correlation of 0.56954, the highest
experienced although the statistical significance is only 0.3162. The
low significance is probably due to the small sample size (N=5). The
felted glass runs were all four hour runs, however, and this could
account for the seemingly better data for the felted glass media.
All of these variables could have been studied independently of
each other with an efficient experiment design.
Model Fittings
A model was fitted to see if outlet grain loading was predict-
able or a function of A/C and the filter medium. It was hampered
by the prevalence of two hour runs. A comparison of predicted and
observed grain loading values indicates how well the model fits and
thus how well filter media and A/C explain grain loading. Table
A-7 shows that in some cases the results are good while in others
they are not.
- 113 -
-------
Table A-7
Comparison of Predicted and Observed Grain Loading Values
Observation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Observed
Value
0.00056500
0.00042200
0.00069400
0.00032600
0.00067300
0.00021700
0.00029900
0.00052600
0.00096000
0.00105000
0.00095500
0.00062500
0.00162000
0.0024500
0.00064100
0.00067100
0.00059500
Predicted
Value
0.00056440
0.00056440
0.00041274
0.00041274
0.00049362
0.00044509
0.00070079
0.00059161
0.00059161
0.00091106
0.00070887
0.00091106
0.00100673
0.00082072
0.00082072
0.00056192
0.00056192
Residual
-0.00000140
-0.00014440
0.00028126
-0.00008674
0.00017938
-0.00022809
-0.00040179
-0.00006561
0.00036839
0.0013894
0.00024613
-0.00028606
0.00061327
-0.00057572
-0.00017972
0.00010908
0.00003308
- 114 -
-------
Appendix A-8
Sample Cost Calculations
for
Fabric Filters
Electrostatic Precipitators
Wet Scrubbers
- 115 -
-------
Appendix A-8
Fabric Filter
Operating and Annualized Costs
Sample Calculations
Formula for calculating theoretical operating and annual 1zed cost
of control were taken from: Edmlnsten, N.G. and Bunyard, F.L., "A Sys-
tematic Procedure for Determining the Cost of Controlling Particulate
Emissions from Industrial Sources", JAPCA V20 N7, p. 446, July 1970.
I. Fabric Filter Operating Cost:
Case - Teflon Felt at A/C = 5.8/1
0.7457
G = S
6356E PHK + M
Where: G = Theoretical annual cost for operation and mainten-
ance
S = Design capacity, acfm
P = Pressure drop, inches of water
E = Fan efficiency, assumed to be 60% (expressed as
0.60)
0.7457 - A constant, 1 horsepower = .7457 kilowatt
H = Annual operating time, 6240 hours (24 hours/day
x 5 days/week x 52 weeks/year = 6240 hours/year)
K = Power costs, $/KWH
M = Maintenance cost, $/ACFM (based on 25% bag replac-
ment per year)
- 116 -
-------
Sample Calculations
(continued)
In this case:
5=140,000 acfm
P=7 inches of water
E=60%
H=6,240 hours
K=$0.0250/KWH
M=(number of bags in house x 25% replacement rate x cost per bag) S
Assuming a 60% fan efficiency reduces the above equation for G to:
G=S (195.5 x 10-6 PHK + M)
Substituting the figures above yields:
6^140,000 (195.5 x 10'6 x 7 x 6240 x .0250 + .2623)
= 140,000 (.2135 + .2623)
=140,000 (.4758)
=66,612
* Assumes 5.5 inches for the baghouse, 1.5 inches for the inlet duct, etc.
II. Total annualized cost of control is equal to the annual operating cost
plus annualized capital cost.
Annual!zed Capital Cost = 0.133 x Installed Costs
Assumptions:
1. Purchase and installation costs are depreciated over fifteen (15) years.
2. The straight line method of depreciation (6 2/3% per year) is used.
3. Other costs called capital costs are assumed to be equal
- 117 -
-------
S.cont. to the amount of depredation. Therefore, depredation
plus other capital charges amount to 13 1/3 percent of the
initial capital costs of the equipment.
In this case: Teflon Felt at A/C = 5.8
Total annualized cost of control = .133 x Installed Costs + Operating
costs
= .133 x $608,104 + $66,612
= 80,878 + 66,612
= $147,490
- 118 -
-------
APPENDIX A-8 (continued)
ELECTROSTATIC PRECIPITATOR
Operating and Annualized Cost Calculations
Formula for calculating theoretical operating and annualized cost of control
were taken from: Edminsten, N. G. and Bunyard, F. L., "A Systematic Procedure
for Determining the Cost of Controlling Particulate Emmissions from Industrial
Sources", JAPCA V20 N7, p. 446. July 1970.
1. Electrostatic Precipitator Operating Cost:
G = S (JHK +M)
Where,
G=Theoretical Annual Operating Cost
S=Design Capacity, ACFM
J*=Power Required, Kilowatts/ACFM
H=Annual Operating Time, 6240 Hours
K=Power Costs, $/KWH
M=Maintenance Costs, $/ACFM
*Does not include power for main fan.
at 98.5% Efficiency
6=140,000 (.0008) (6240) (0.025) + .083
=140,000 (0.1248 +0.083)
= 140,000 (0.2078)
= $29,092
- 119 -
-------
Operating and Annuallzed Cost Calculations
(continued)
Main fan Costs, (F) = S(.7457 PHK
6155F )
Where,
S = Design Capacity, ACFM
.7457 = A Constant (1 Horsepower = 0.7457 Kilowatts)
E = Fan Efficiency, 60%
P* = Pressure Drop, Inches of water
H = Annual Operating Time, 6240 Hours
K = Power Cost, $/KWH
F = 140,000 (.7457 (2) (6240) (0.025)
(6356) (.6)
F = 140,000 (.0610)
F = $8,540
*Assumes 0.5 Inches for ESP plus 1.5 Inches for inlet duct, etc.
Total Annual Operating Costs = G + F
at 98.5% Efficiency $29,092 + $8,540 = $37,632, or $0.27/ACFM
II. Electrostatic Predpitator Annuallzed Costs
Total annualized cost of control 1s equal to the annual
operating cost plus the annualized capital cost.
Annualized Capital Cost * = 0.133 X Installed Cost
Total Annuallzed Cost = 0.133 X Installed Cost + Operating Cost
at 98.5% Efficiency = (0.133) (682,815) + 37,632
= $90.814 + $37,632 = $128,446,or $0.92/ACFM
*5ee fabric filter case for annualized capital cost assumptions
- 120 -
-------
Appendix A-8
WET SCRUBBERS
Operating and Annualized Cost Calculations
Formula for calculating theoretical operating and annual-
izedcost of control were taken from: Edminsten, N.G. and
Bunyard, F.L., "A Systematic Procedure for Determining the
Cost of Controlling Particulate Emissions from Industrial
Sources," Journal of the Air Pollution Control Association,
Vol. 20, No. 7, P. 446, July 1970.
I. Wet Scrubber Operating Cost:
G = S 0.7457 HK (Z +(Qh/1980)) + WHL + M
Where: G = theoretical annual operating cost
S = design capacity, ACFM
0.7457 = constant (1 horsepower=0.7457 KW)
H = annual operating time, 6240 hours
K = power costs, $/KWH
Z = contact power (or, total power input
required for collection efficiency)
horsepower/ACFM
Q = liquor circulation, gallons/ACFM
h = physical height liquor is pumped in1
circulation system, in feet
W = make-up liquor consumption, gallons/ACFM
L = liquor cost, $/ACFM
M = maintenance cost, $/ACFM
For this application:
S = 140,000 ACFM
H = 6240 hrs.
K = $0.025/KW1I
Z*= 0.015 HP/ACFM (for high efficiency)
Q*= 0.008 gal/ACFM
n*= 30 feet
w*= 5 x lO-4 gal/hr ACFM
- 121 -
-------
—3
L*= $0.67 x 10~ /gal/hr (value inflated from
. Edminsten & Bunyard value at 6%/year)
M - $0.05/ACFM (typical to high value)
* Values for a typical system from tables in the
Edminsten and Bunyard article.
G = 140,000 0.7457(6240)(0.025)(0.015 + (0.008 x 30))
( 1980 )
-4 -3
+ (5 x 10 )(6240)(0.67 x 10 ) + 0.05
G = 140,000 (1.7589 + 0.0021 + 0.05)
G = 140,000 (1.811)
G = $253,539 or $1.81/ACFM
II. Wet Scrubber Annualized Costs
Total annualized cost of control is equal to the
annual operating cost plus the annualized capital
cost.
*
Annualized Capital Cost = 0.133 x Installed Cost
Total Annualized Cost = Annualized Capital Cost
+ Annual Operating Cost
at 99% efficiency. Total Annualized Cost =
(0.133 x $707,840) + $253,359
$94,143 + $253,359
$347,681 or $2.48/ACFM
*See fabric filter case for annualized capital cost
assumptions.
- 122 -
-------
TF.CHNICAL REPORT DATA
(Please readInuructtons on the reverse before completing/
REPORT NO.
EPA-600/7-78-078
4. TITLE -DsuBT,TLE
'Applying
2.
fired Boilers: A .Pilot-scale Investigation
to Refuse-
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
May 1978
G. PERFORMING ORGANIZATION CODE
7. AUTHOR.S, j D McKenna, J.C.Mycock, R.L. Miller,
and K. D. Brandt
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Nashville Thermal Transfer Corp.
110 First Avenue, South
Nashville, Tennessee 37201
10. PRC'GRAM ELEMENT NO.
EHE624
11. CONTHACT/CP.ANT NO
Grant R804223
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF HEPORT AND Pi
Final; 5/76 - 8/77
ERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
is. SUPPLEMENTARY NOTES JERL-RTP project officer i«? James H. Turner, Mail Drop 61, 919/
541-2925.
16. ABSTRACT
repOrt gives results of a pilot-scale investigation to determine the
techno-economic feasibility of applying fabric filter dust collectors to solid refuse
fired boilers. The pilot facility, installed on a slipstream of a 130,000 Ib/hr boiler,
was sized to handle 9000 acfm at an apparent filtering velocity of 6 fpm. Filter media
evaluated included a woven glass , a felted glass , and a PTFE laminate on a woven
backing. The three filter media had overall efficiencies greater than 99. 8%, at
apparent filtering velocities of 6 fpm or less , with an inlet loading of 0. 5 gr/dscf .
For the brief exposures during performance testing , none of the bag materials
showed an wear problems. Installed costs for a woven glass fabric filter (the least
expensive material tested) capable of handling 140,000 acfm were #317,000, $422,000
and $817,000 ($2.26, $3.01, and $5.83/acfm, respectively) at corresponding air-to-
cloth ratios of 8. 9, 5. 8, and 2.9. Installed, operating, and annualized costs for
other filter media, as well as costs for electrostatic precipitation and wet scrubbing,
are also presented.
7.
KE-Y WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution Tetrafluoroethylenc
Dust Collectors Resins
Fabric Laminates
Boilers
Refuse
Fuels
Scrubbing
Dust
Fabrics
Glass Fibers
Felts
9. DISTRIBUTION STATEMENT
Unlimited
EPA Form 2220-1 (9-73)
123
b.lDENTIFIERS OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Particulate
Fabric Filters
Felted Glass
Solid-refuse Fuels
PTFE
19. SECURITY CLAf
Unclassified
(Ttils Report!
20. ".OCURITY CLASS ('nilspage)
Unclassified
c. COSATI Held/Croup
13B
13A
11G
11E
11B
111
11D
2 ID
07A.13H
21. NO. OF PAGES
134
P2. PRICE
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