ABMA
American
Boiler Manufacturers
Association
1500 Wilson Boulevard
Arlington VA 22209
DoE
United States
Department
of Energy
Division of Power Systems
Energy Technology Branch
Washington DC 20545
EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-80-138a
May 1980
Field Tests of Industrial
Stoker Coal-fired Boilers
for Emissions Control and
Efficiency Improvement
Site K
Interagency
Energy/Environment
R&D Program Report
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of, and development of, control technologies for energy
systems; and integrated assessments of a wide'range of energy-related environ-
mental issues.
EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
for publication. Approval does not signify that the contents necessarily reflect
the views and policies of the Government, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-80-138a
May 1980
Field Tests of Industrial Stoker Coal-fired
Boilers for Emissions Control and
Efficiency Improvement Site K
by
P.L Langsjoen, J.O. Burlingame,
and J.E. Gabrielson
KVB, Inc.
C . 76 Olson Memorial Highway
Minneapolis, Minnesota 55422
lAG/Contract Nos. IAG-D7-E681 (EPA), EF-77-C-01 -2609 (DoE)
Program Element No. EHE624
Project Officers: R.E. Hall (EPA) and W.T. Harvey, Jr. (DoE)
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
U.S. DEPARTMENT OF ENERGY
Division of Power Systems/Energy Technology Branch
Washington, DC 20545
and
AMERICAN BOILER MANUFACTURERS ASSOCIATION
1500 Wilson Boulevard
Arlington, VA 22209
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ACKNOWLE DGEMENTS
The authors wish to express their appreciation for the assistance
and direction given the program by project monitors W. T. (Bill) Harvey of
the United States Department of Energy (DOE) and R. E. (Bob) Hall of the
United States Environmental Protection Agency (EPA). Thanks are due to
their agencies, DOE and EPA, for co-funding the program.
We would also like to thank the American Boiler Manufacturers
Association, ABMA Executive Director, W. H. (Bill) Axtman, ABMA Assistant
Executive Director, R. N. (Russ) Mosher, ABMA's Project Manager, B. c. (Ben)
Severs, and the members of the ABMA Stoker Technical Committee chaired by
W. B. (Willard) McBurney of the McBurney Corporation for providing support
through their time and travel to manage and review the program. The partici-
pating committee members listed alphabetically are as follows:
R. D. Bessette Island Creek Coal Company
T. Davis Combustion Engineering
N. H. Johnson Detroit Stoker
K. Luuri Riley Stoker
D. McCoy E. Keeler Company
J. Mullan National Coal Association
E. A. Nelson Zurn Industries
E. Poitras The McBurney Corporation
P. E. Ralston Babcock and Wilcox
D. C. Reschley Detroit Stoker
R. A. Santos Zurn Industries
We would also like to recognize the KVB engineers and technicians
who spent much time in the field, often under adverse conditions, testing
the boilers and gathering data for this program. Those involved at Site K in
addition to co-author Jim Burlingame were Russ Parker, Mike Jackson, and
Jim Demont.
Finally, our gratitude goes to the host boiler facilities which in-
vited us to test their boiler. At their request, the facilities will remain
anonymous to protect their own interests. Without their cooperation and
assistance this program would not have been possible.
11
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TABLE OF CONTENTS
Section Page
ACKNOWLEDGEMENTS ii
LIST OF TABLES v
LIST OF FIGURES vi
1.0 INTRODUCTION 1
2.0 EXECUTIVE SUMMARY 3
3.0 DESCRIPTION OF FACILITY TESTED AND COALS FIRED 11
3.1 Boiler K Description 11
3.2 Overfire Air System 11
3.3 Test Port Locations 13
3.4 Coals Utilized 13
4.0 TEST EQUIPMENT AND PROCEDURES 17
4.1 Gaseous Emissions Measurements (NOx, CO, CO2, O2, HC) . 17
4.1.1 Analytical Instruments and Related Equipment . . 17
4.1.2 Recording Instruments 21
4.1.3 Gas Sampling and Conditioning System 21
4.1.4 Gaseous Emission Sampling Techniques 21
4.2 Sulfur Oxides (SOx) Measurement and Procedures .... 23
4.3 Particulate Measurement and Procedures 25
4.4 Particle Size Distribution Measurement and Procedures 28
4.5 Coal Sampling and Analysis Procedure 29
4.6 Ash Collection and Analysis for Combustibles 31
4.7 Boiler Efficiency Evaluation 32
4.8 Trace Species Measurement 32
5.0 TEST RESULTS AND OBSERVATIONS 35
5.1 Overfire Air 35
5.1.1 Particulate Loading vs Overfire Air 35
5.1.2 Nitric Oxide vs Overfire Air 38
5.1.3 Carbon Monoxide vs Overfire Air 39
5.1.4 Boiler Efficiency vs Overfire Air 39
5.2 Excess Oxygen and Grate Heat Release 40
5.2.1 Excess Oxygen Operating Levels 40
5.2.2 Particulate Loading vs Oxygen and Grate Heat
Release 42
5.2.3 Nitric Oxide vs Oxygen and Grate Heat Release . 45
5.2.4 Carbon Monoxide vs Oxygen and Grate Heat Release 50
5.2.5 Combustibles in the Ash vs Grate Heat Release . 54
5.2.6 Boiler Efficiency vs Grate Heat Release .... 54
5.3 Coal Properties 61
5.3.1 Chemical Composition of the Coals 61
5.3.2 Coal Size Consistency 66
5.3.3 Effect of Coal Properties on Emissions and
Efficiency 66
ill
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TABLE OF CONTENTS
(Continued)
Section Page
5.4 Particle Size Distribution of Flyash 73
5.5 Efficiency of Mechanical Dust Collector 77
5.6 Souce Assessment Sampling System (SASS) 80
5.7 Data Tables 80
APPENDIX A - English and Metric Units to SI Units 86
APPENDIX B - SI Units to English and Metric Units 87
APPENDIX C - SI Prefixes 88
APPENDIX D - Emissions Units Conversion Factors 89
iv
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LIST OF TABLES
Table Page
2-1 Outline of Tests Conducted At Site K 8
2-2 Emission Data Summary 9
3-1 Design Data 12
3-2 Average Coal Analysis 16
5-1 Effect of Overfire Air on Emissions and Efficiency 37
5-2 Particulate Loading vs Overfire Air 38
5- 3 Carbon Monoxide vs Overfire Air 39
5-4 Boiler Efficiency vs Overfire Air 40
5-5 Ash Carryover vs Firing Conditions 48
5-6 Average Nitric Oxide Concentration vs Load 50
5-7 Boiler Efficiency vs Load 59
5-8 Coal Properties Corrected to a Constant l06Btu Basis .... 61
5-9 Fuel Analysis - Alabama Brilliant Coal (Washed) 62
5-10 Fuel Analysis - Alabama Brilliant Coal (Unwashed) 63
5-11 Fuel Analysis - Alabama Brilliant Coal (Crushed) 64
5-12 Mineral Analysis of Coal Ash 65
5-13 As Fired Coal Size Consistency 67
5-14 Particulate Loading vs Coal 71
5-15 Sulfur Measurements 72
5-16 Boiler Efficiency vs Coal 73
5-17 Description of Particle Size Distribution Tests at the
Boiler Outlet ' 74
5-18 Results of Particle Size Distribution Tests at the Boiler
Outlet 77
5-19 Dust Collector Efficiency vs Load and Coal 77
5-20 Efficiency of Dust Collector 79
5-21 Polynuclear Aromatic Hydrocarbons Analyzed in the Site K
SASS Sample 80
5-22 Particulate Emissions 81
5-23 Heat Losses and Efficiencies 82
5-24 Percent Combustibles in Refuse 83
5-25 Steam Flows and Heat Release Rates 84
v
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LIST OF FIGURES
Figure
3-1 Boiler K Schematic 14
3-2 Boiler K Sample Plane Geometry 15
4-1 Plow Schematic of Mobile Flue Gas Monitoring Laboratory . 22
4-2 SOx Sample Probe Construction 24
4-3 Sulfur Oxides Sampling Train 24
4-4 EPA Method 6 Sulfur Oxide Sampling Train 26
4-5 EPA Method 5 Particulate Sampling Train 27
4-6 Brink Cascade Impactor Sampling Train 30
4-7 Source Assessment Sampling (SASS) Flow Diagram 33
5-1 Over fire Air vs Grate Heat Release 36
5-2 Excess Oxygen vs Grate Heat Release 41
5-3 Boiler Out Part, vs Grate Heat Release 43
5-4 Multiclone Outlet Part, vs Grate Heat Release 44
5-5 Multiclone Outlet Part, vs Excess Oxygen 46
5-6 Opacity vs Grate Heat Release 47
5-7 Nitric Oxide vs Grate Heat Release 49
5-8 Nitric Oxide vs Excess Oxygen 51
5-9 Carbon Monoxide vs Grate Heat Release 52
5-10 Carbon Monoxide vs Excess Oxygen 53
5-11 Boiler Outlet Combustibles vs Grate Heat Release 55
5-12 Multiclone Outlet Combustibles vs Grate Heat Release ... 56
5-13 Bottom Ash Combustibles vs Grate Heat Release 57
5-14 Boiler Efficiency vs Grate Heat Release 59
5-15 Boiler Efficiency vs Grate Heat Release 60
5-16 Size Consistency of "As Fired" Washed Coal vs ABMA Recom-
mended Limits of Coal Sizing for Overfeed Stokers -
Test Site K 68
5-17 Size Consistency of "As Fired" Unwashed Coal vs Recommended
Limits of Coal Sizing for Overfeed Stokers - Test
Site K 69
5-18 Size Consistency of "As Fired" Crushed Coal vs ABMA
Recommended Limits of Coal Sizing for Overfeed Stokers
Test Site K 70
5-19 Particle Size Distribution at the Boiler Outlet as
Determined by Brink Cascade Impactor - Test Site K . . 75
5-20 Particle Size Distribution at the Boiler Outlet as
Determined by SASS Gravimetrics - Test Site K 76
5-21 Multiclone Efficiency vs Grate Heat Release 78
vi
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1.0 INTRODUCTION
The principal objective of the test program described in this report,
one of several reports in a series, is to produce information which will in-
crease the ability of boiler manufacturers to design and fabricate stoker
boilers that are an economical and environmentally satisfactory alternative
to oil-fired units. Further objectives of the program are to: provide
information to stoker boiler operators concerning the efficient operation of
their boilers; provide assistance to stoker boiler operators in planning
their coal supply contracts; refine application of existing pollution control
equipment with special emphasis on performance; and contribute to the design
of new pollution control equipment.
In order to meet these objectives, it is necessary to define stoker
boiler designs which will provide efficient operation and minimum gaseous and
particulate emissions, and define what those emissions are in order to facili-
tate preparation of attainable national emission standards for industrial
size, coal-fired boilers. To do this, boiler emissions and efficiency must
be measured as a function of coal analysis and sizing, rate of flyash rein-
jection, overfire air admission, ash handling, grate size, and other variables
for different boiler, furnace, and stoker designs.
A field test program designed to address the objectives outlined above
was awarded to the American Boiler Manufacturers Association (ABMA), sponsored
by the United States Department of Energy (DOE) under contract number
EF-77-C-01-2609, and co-sponsored by the United States Environmental Protection
Agency (EPA) under inter-agency agreement number IAG-D7-E681. The program is
directed by an ABMA Stoker Technical Committee which, in turn, has subcontracted
the field test portion to KVB, Inc., of Minneapolis, Minnesota.
This report is the Final Technical Report for the last of eleven
boilers tested under the ABMA program. It contains a description of
the facility tested, the coals fired, the test equipment and procedures, and
the results and observations of testing. There is also a data supplement to
this report containing the "raw" data sheets from the tests conducted. The
data supplement has the same EPA report number as this report except that it
KVB 4-15900-548
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is followed by "b" rather than "a". As a compilation of all data obtained
at this test site, the supplement acts as a research tool for further data
reduction and analysis as new areas of interest are uncovered in subsequent
testing.
At the completion of this program, a Final Technical Report will
combine and correlate the test results from all sites tested. A report
containing operating guidelines for boiler operators will also be written,
along with a separate report covering trace species data. These reports
will be available to interested parties through the National Technical Infor-
mation Service (NTIS) or through the EPA's Technical Library.
Although it is EPA policy to use S.I. units in all EPA sponsored
reports, an exception has been made herein because English units have been
conventionally used to describe boiler design and operation. Conversion
tables are provided in the Appendix for those who prefer S.I. units.
To protect the interests of the host boiler facilities, each test
site in this program has been given a letter designation. As the eleventh
site tested, this is the Final Technical Report for Test Site K under the
program entitled, "A Testing Program to Update Equipment Specifications and
Design Criteria for Stoker Fired Boilers."
KVB 4-15900-548
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2.0 EXECUTIVE SUMMARY
A coal fired overfeed stoker with traveling grate was extensively
tested for emissions and efficiency between September 15 and Noveiriber 12,
1979. This section summarizes the results of these tests and provides references
to supporting material found in the main text of this report.
UNIT TESTED; Described in Section 3.0, page 11.
Riley Boiler
Built 1977
Type VO
50,000 Ib/hr rated capacity
125 psig operating pressure
Saturated steam
Economizer
Riley Stoker
Overfeed stoker
Traveling grate
One row overfire air jets on front wall
COALS TESTED; Individual coal analysis listed in Tables 5-9, 5-10, 5-11 and
5-12. Commentary in Section 3.4, page 13, and Section 5.3,
page 61.
* Washed Alabama Brilliant Coal
13,237 Btu/lb
4.14% Ash
1.11% Sulfur
6.49% Moisture
2100° F Initial ash deformation temperature
^ Unwashed Alabama Brilliant Coal
12,280 Btu/lb
10.24% Ash
1.01% Sulfur
6.19% Moisture
2110°P Initial ash deformation temperature
KVB 4-15900-548
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Washed and Crushed Alabama Brilliant Coal
12,994 Btu/lb
4.68% Ash
1.31% Sulfur
7.35% Moisutre
2190°F Initial ash deformation temperature
OVERFIRE AIR TEST RESULTS; Normal operating practice on this boiler was to
maintain overfire air pressure at 2.5" 1^0 for
all boiler loads. Three tests were conducted at
overfire air pressures of 5.0" H2O and one at
7.5" H2O with the following results. (Section
5.1, page 35)
Particulate Loading
Uncontrolled and controlled particulate loadings dropped an average
20% when overfire air pressure was increased. A portion of this
drop is attributed to more complete carbon burnout. (Section
5.1.1, page 35)
Nitric Oxide
Nitric oxide emissions were not influenced by the variable over-
fire air. (Section 5.1.2, page 38)
9 Carbon Monoxide
Carbon monoxide emissions were reduced by an average of 60% when
overfire air was increased. (Section 5.1.3, page 39)
Boiler Efficiency
Boiler efficiency was not significantly altered by changes in
overfire air pressure. (Section 5.1.4, page 39)
BOILER EMISSION PROFILES; Boiler emissions and efficiency were determined at
of 50%, 75% and 100% of the units design capacity.
At each load, excess oxygen varied within the range
of ±1.4%. Data magnitude and trends were as
follows. (Section 5.2, page 40)
Excess Oxygen OperaJ i.ng Levels
Excess oxygen decreased sharply as load increased. At full load,
excess oxygen ranged from 6.0 to 8.8% O2. Excess oxygen ranged
from 9.8 - 11.6% at 75% capacity, and 10.8 - 13.6% at 50% capacity.
(Section 5.2.1, page 40)
KVB 4-15900-548
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Particulate Loading
Uncontrolled particulate mass loading increased with increasing
load, while controlled particulate mass loading decreased with
increasing load. At full load, the washed coal averaged 0.78
Ib/lO^stu uncontrolled particulate mass loading, and 0.14 lb/10
Btu controlled. (Section 5.2.2, page 42)
^ Nitric Oxide
Nitric oxide was relatively invariant with load under normal oper-
ating conditions, and averaged 0.32 lb/106Btu. At full load,
nitric oxide increased at the rate of 0.033 lb/10^Btu for each
1% O2 increase. (Section 5.2.3, page 45)
Carbon Monoxide
Carbon monoxide varied within the general range of 100 to 500 ppm.
No correlation with load was observed. (Section 5.2.4, page 50)
Combustibles in the Ash
Combustibles averaged 32% in the uncontrolled flyash, 29% in the
dust collector hopper ash and 42% in the bottom ash. Bottom ash
combustible levels were unusually high. No correlation with
load was observed. (Section 5.2.5, page 54)
^ Boiler Efficiency
Boiler efficiency increased with increasing load. At full load
it averaged 78.4%. If bottom ash combustibles were a more normal
20% rather than the measured 42%, full load boiler efficiency
would be 80.3%. (Section 5.2.6, page 54)
COAL PROPERTIES; The washed coal was the primary fuel at this facility. The
unwashed coal was distinguished by its high ash content, and
the crushed coal by its high fines. The effect of these
coal properties on emissions and efficiency were as follows.
(Section 5.3, page 61)
Excess Oxygen Operating Conditions
The unwashed coal used about 1% more 02 than the washed coal,
and the crushed coal used about 1% less 02- (Figure 5-2, page 41)
KVB 4-15900-548
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Particulate Loading
Crushed coal produced 58% more uncontrolled particulates than
the washed coal at full load. Unwashed coal produced 180%
more uncontrolled particulates than the washed coal. Con-
trolled particulates did not correlate as strongly with coal
properties. (Figures 5-3 and 5-4, pages 43 and 44)
Nitric Oxide
No correlation with coal properties was observed. (Figure
5-7, page 49)
Carbon Monoxide
No correlation with coal properties was observed. (Figure
5-9, page 52)
Sulfur Dioxide
Sulfur content was not a variable. A sulfur balance attempt
was not successful. (Table 5-15, page 72)
combustibles in the Ash
No correlation with coal properties was observed. (Figures 5-11,
5-12, 5-13, pages 55, 56 and 57)
Boiler Efficiency
Unwashed coal resulted in the lowest boiler efficiency due to a
higher combustible heat loss. (Figures 5-14 and 5-15, pages
58 and 60)
PARTICLE SIZE DISTRIBUTION OF FLYASHt Three particle size distribution
measurements were made by Brink Cascade
Impactor and one by SASS Cyclones on
the uncontrolled flyash. At full load,
10% of the sampled flyash was smaller
than 3 micrometers. (Figures 5-19 and
5-20, pages 75 and 76)
EFFICIENCY OF MECHANICAL DUST COLLECTOR; Collector efficiency was determined for
each test by simultaneous inlet and
outlet particulate mass loading deter-
minations. Collector efficiency in-
creased with increasing load and with
increasing inlet loading. (Table 5-19,
page 77)
KVB 4-15900-548
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SOURCE ASSESSMENT SAMPLING SYSTEM (SASS): Flue gas was sampled for poly-
nuclear aromatic hydrocarbons
and trace elements during one full
load test on the washed coal.
Data will be presented in a separ-
ate report at the completion of
this test program. (Section 5.6/
page 80)
The Test Plan and Emission Data Summary are presented in Tables 2-1
and 2-2 on the following pages. For reference, additional data tables are in-
cluded in Section 5.7. A "Data Supplement" containing all the unreduced data
obtained at Site K is available under separate cover for those who wish to
further analyze the data. The "Data Supplement" has the same EPA document
number as this report except that it is followed by the letter "b" rather
than "a". Copies of this report and the Data Supplement are available
through EPA and the National Technical Information Service (NTIS).
KVB 4-15900-548
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TABLE 2-1
OUTLINE OP TESTS CONDUCTED AT SITE K
APPROXIMATE FIRING CONDITIONS
TEST NUMBERS*
% Design
Capacity % 02
100 8.5
fl II
7.5
II II
6.0
75 10.5
50 12.5
ii M
Overfire Air
"H50
7.5
2.5
5.0
2.5
2.5
2.5
5.0
2.5
Washed
Coal
6
1, 4
7, 8
5
11
3, 10, 18
9
2
Unwashed
Coal
14
13
12
Crushed
Coal
-_
16
15
17
* Parameters measured during each test except Test 18 include 02,
C02» CO, NO, uncontrolled particulate loading and controlled
particulate loading. Test 18 included ©2, CX>2, NO, SOx and SASS
KVB 4-15900-548
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TABLE 2-2
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Date
10/11/79
10/13/79
10/15/79
10/16/79
10/24/79
10/24/79
10/25/79
10/26/79
10/27/79
10/29/79
10/30/79
11/06/79
11/06/79
11/07/79
11/08/79
11/09/79
11/10/79
11/12/79
% Design
Capacity
97
50
74
100
96
95
101
100
41
74
102
59
77
101
73
102
56
78
Excess
Coal* Air, %
1
1
1
1
1
1
1
1
1
1
1
2
2
2
3
3
3
1
67
174
100
59
51
60
48
49
149
85
40
148
113
62
84
37
98
81
EMISSION DATA SUMMARY
TEST SITE K
dry
8.8
13.7
10.9
8.2
7.5
8.3
7.2
7.3
13.0
10.1
6.4
12.9
11.6
8.5
10.0
6.0
10.8
9.8
C02
dry
9.6
6.0
8.0
9.7
10.0
9.6
10.6
10.4
6.1
8.1
10.9
6.7
7.0
9.1
8.4
11.1
7.7
8.6
CO
ppm
dry
537
339
222
275
208
70
126
105
187
250
182
318
479
313
237
440
182
NO
ppm
dry
240
226
290
228
214
258
214
236
223
238
235
302
224
261
200
200
209
209
NO as NO2 SOx
lb/106 lb/106
Btu Btu
0.326
0.311
0.392
0 . 309
0.285
0.362
0.294
0.320
0.303
0.318
0.315
0.416
0.312
0.355
0.277
0.273
0.291
0.284 1.159
Parti culate
Boiler Out
lb/106Btu
1.240
0.737
0.799
0.758
0.755
0.655
0.850
0.639
0.477
0.707
0.571
1.251
2.060
2.202
1.127
1.231
0.698
Parti culate
D.C. Out
lb/106Btu
0.199
0.190
0.226
0.148
0.158
0.134
0.129
0.112
0.144
0.118
0.124
0.239
0.197
0.161
0.147
0.140
0.144
* 1 - Washed Coal; 2 - Unwashed Coal; 3 - Crushed Coal
KVB 4-15900-548
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CTHIS PAGE INTENTIONALLY LEFT BLANK)
10
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3.0 DESCRIPTION OF FACILITY TESTED
AND COALS FIRED
This section discusses the general physical layout and operational
characteristics of the boiler tested at Test Site K. The coals utilized
in this test series are also discussed.
3.1 BOILER K DESCRIPTION
Boiler K was built by Riley Stoker Corporation in 1976. This unit
is a type VO boiler designed for 200 psig, and capable of a maximum continuous
capacity of 50,000 pounds of steam per hour at 125 psig and saturated
temperature. The unit has a Riley traveling grate stoker. Coal is mass
fed to the front end of the grate and ash is continuously discharged at
the back end. There is no suspension burning. Undergrate air can be con-
trolled in six zones. Design data on the boiler and stoker are presented
in Table 3-1.
The boiler is equipped with an economizer and a dust collector.
There is no flyash reinjection.
3.2 OVERFIRE AIR SYSTEM
The overfire air system on Boiler K consists of a row of air jets
on the front wall, five feet above the grate and 30° below horizontal. The
overfire air is supplied by an independent fan with maximum flow producing
7.5" H2O pressure at the jets. Normal overfire air operating pressure
during testing was 2.5" I^O. This low setting was used because it had been
recommended by the Riley startup man.
KVB 4-15900-548
11
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TABLE 3-1
DESIGN DATA
TEST SITE K
BOILER: Manufacturer
Type
Boiler Heating Surface
Design Pressure
Tube Diameter
Riley Stoker Corp.
VO
6,669 ft2
200 psig
3-1/4 "
FURNACE;
Volume
2,614 ft3
STOKER: Manufacturer
Type
Width
Length
Effective Grate Area
Riley Stoker Corp.
Traveling Grate
10'0"
16'0"
160 ft2
HEAT RATES: Steam Flow
Input to Furnace*
Furnace Width Heat Release*
Grate Heat Release*
Furnace Liberation
50,000 Ibs/hr
69 x!06Btu/hr
6.9 x!06Btu/hr-ft
424,000 Btu/hr-ft2
26,200 Btu/hr-ft3
* The heat input and heat release rates were determined
from coal feed rates and are not necessarily those of
the manufacturer.
KVB 4-15900-548
12
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3.3 TEST PORT LOCATIONS
Emission measurements were made at two locations at the
boiler outlet (uncontrolled particulate emissions) and at the dust collector
outlet (controlled particulate emissions). The locations of these sample
sites are shown in Figure 3-1. Their geometry is shown in Figure 3-2.
Whenever particulate loading was measured it was done simultane-
ously at both locations using 24-point traverses. Gaseous measurements of
°2' C02' co anc^ NO were obtained by pulling samples individually and
compositely from six probes distributed along the width of the boiler out-
let and from one probe that was placed in each of the three sampling ports
at the dust collector outlet. NO2 and unburned hydrocarbons were measured
by pulling sample through a heated line attached to one of the middle gaseous
probes at the boiler outlet. SOx measurements and SASS samples for organic
and trace element determinations were obtained from single points within
the boiler outlet duct.
3.4 COALS UTILIZED
Three forms of coal from one mine were test fired at Site K. All
three were from the Brilliant Coal Company in Brilliant, Alabama. The
primary coal was a washed coal, sized at 1-1/4x0 with low fines.
For test purposes, a quantity of unwashed coal from the same mine
was ordered. The unwashed coal was higher in ash and lower in heating value.
It was reported to have a high clay content. This coal caused some problems
with the coal conveyor system. Rocks in the coal were shearing pins in the
conveyor. Despite this problem and its unfamiliarity to the operators, three
tests were successfully completed on it.
The third coal is referred to as the crushed coal in this report.
The plant was equipped with a coal crusher which was ordinarily bypassed.
Permission was obtained to run a quantity of the washed coal through this
crusher to reduce its top size to 3/4 inch and increase its fines.
Coal samples were obtained from the coal scales apron feeder
during each test. These samples were sent to an independent laboratory for
KVB 4-15900-548
13
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DUST COLLECTOR
OUTLET SAMPLING
PLANE -
BOILER OUTLET
SAMPLING PLANE i
Figure 3-1. Boiler K Schematic
KVB 4-15900-548
14
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BOILER OUTLET SAMPLING PLANE
CROSS SECTIONAL AREA = 28.91 FT2
_l
4.
J
4-
1
_. +0
|
4- 4- O+ 4-4-
4-04- 4- 4- 4-
4-A 4- 4- +0 +
+
0 D4-
+
L
04-
1
r
r
2'6.5'
4- Particulate Sampling Point
O Gaseous Sampling Point
D SASS Sampling Point
A SOx Sampling Point
t
3'0'
4- 4-
4- 4-
4- 4-
4-
4-
4-4-4-
+ 4-4-
+ + +
n n n r
DUST COLLECTOR OUTLET
SAMPLING PLANE
CROSS SECTIONAL AREA =9.0 FT2
Figure 3-2. Boiler K Sample Plane Geometry
KVB 4-15900-548
15
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proximate analysis. One sample of each coal was also analyzed for ultimate
analysis, minerals in the ash, ash fusion temperature, hardgrove grindability,
free swelling index and sulfur forms. The data are summarized in Table 3-2
Individual sainple analysis are found in Section 5.2, Tables 5-9, 5-10, 5-n
and 5-12.
TABLE 3-2
AVERAGE COAL ANALYSIS
TEST SITE K
PROXIMATE (AS Rec'd)*
% Moisture
% Ash
% Volatile
% Fixed Carbon
Btu/Lb
% Sulfur
Washed
6.49
4.14
37.46
51.91
13237
1.11
Unwashed
6.19
10.24
33.64
49.88
12280
1.01
Crushed
7.35
4.68
36.72
51.25
12994
1.31
ULTIMATE (As Rec'd)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (Diff)
**
6.80
73.85
5.00
1.55
0.07
1.39
3.91
7.43
4.76
72.21
4.68
1.44
0.05
1.10
7.98
7.75
5.84
74.25
4.97
1.42
0.06
0.94
4.15
8.37
* Proximate data are average of several samples
** Ultimate data are from single sample
KVB 4-15900-548
16
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4.0 TEST EQUIPMENT AND PROCEDURES
This section details how specific emissions were measured and the
sampling procedures followed to assure that accurate, reliable data were
collected.
4.1 GASEOUS EMISSIONS MEASUREMENTS (NOx, CO, CO2, O2, HC)
A description is given below of the analytical instrumentation, re-
lated equipment, and the gas sampling and conditioning system, all of which
are located in a mobile testing van owned and operated by KVB. The systems
have been developed as a result of testing since 1970, and are operational
and fully checked out.
4.1.1 Analytical Instruments and Related Equipment
The analytical system consists of five instruments and associated
equipment for simultaneously measuring the constituents of flue gas. The
analyzers, recorders, valves, controls, and manifolds are mounted on a panel
in the vehicle. The analyzers are shock mounted to prevent vibration damage.
The flue gas constituents which are measured are oxides of nitrogen (NO, NOx),
carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), and gaseous hydro-
carbons (HC) .
Listed below are the measurement parameters, the analyzer model
furnished, and the range and accuracy of each parameter for the system. A
detailed discussion of each analyzer follows:
Constituent: Nitric Oxide/Total Oxides of Nitrogen (NO/NOx)
Analyzer: Thermo Electron Model 10 Chemiluminescent Analyzer
Range: 0-2.5, 10, 25, 100, 250, 1000, 2500, 10,000 ppm NO
Accuracy: ±1% of full scale
Constituent: Carbon Monoxide
Analyzer: Beckman Model 315B NDIR Analyzer
Range: 0-500 and 0-2000 ppm CO
Accuracy: +1% of full scale
KVB 4-15900-548
17
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Constituent: Carbon Dioxide
Analyzer: Beckman Model 864 NDIR Analyzer
Range: 0-5% and 0-20% CO2
Accuracy: -1% of full scale
Constituent: Oxygen
Analyzer Teledyne Model 326A Fuel Cell Analyzer
Range: 0-5, 10, and 25% O2 full scale
Accuracy: il% of full scale
Constituent: Hydrocarbons
Analyzer: Beckman Model 402 Flame lonization Analyzer
Range: 5 ppm full scale to 10% full scale
Accuracy: il% of full scale
Oxides of nitrogen. The instrument used to monitor oxides of nitrogen
is a Thermo Electron chemiluminescent nitric oxide analyzer. The instrument
operates by measuring the chemiluminescent reaction of NO and 03 to form NO-j
Light is emitted when electronically excited N02 molecules revert to their
ground state. The resulting chemiluminescence is monitored through an optical
filter by a high sensitivity photomultiplier, the output of which is linearly
proportional to the NO concentration.
Air for the ozonator is drawn from ambient air through a dryer and
a ten micrometer filter element. Flow control for the instrument is accomplished
by means of a small bellows pump mounted on the vent of the instrument down-
stream of a separator that prevents water from collecting in the pump.
The basic analyzer is sensitive only to NO molecules. To measure NOx
(i.e., N0+N02), the N02 is first converted to NO. This is accomplished by a
converter which is included with the analyzer. The conversion occurs as the
gas passes through a thermally insulated, resistance heated, stainless steel
coil, with the application of heat, NO2 molecules in the sample gas are re-
duced to NO molecules, and the analyzer now reads NOx. NO2 is obtained by the
difference in readings obtained with and without the converter in operation.
Specifications: Accuracy 1% of full scale
Span stability -1% of full scale in 24 hours
Zero stability -1 ppm in 24 hours
Power requirements 115±10V, 60 Hz, 1000 watts
Response 90% of full scale in 1 sec. (NOx mode),
0.7 sec. NO mode
Output 4-20 ma
KVB 4-15900-548
18
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Sensitivity 0.5 ppm
Linearity -1% of full scale
Vacuum detector operation
Range: 2.5, 10, 25, 100, 250, 1000, 2500, 10,000 ppm
full scale
Carbon Monoxide. Carbon monoxide concentration is measured by a
Beckman 315B non-dispersive infrared analyzer. This instrument measures the
differential in infrared energy absorbed from energy beams passed through a
reference cell (containing a gas selected to have minimal absorption of infra-
red energy in the wavelength absorbed by the gas component of interest) and a
sample cell through which the sample gas flows continuously. The differential
absorption appears as a reading on a scale from 0 to 100 and is then related
to the concentration of the specie of interest by calibration curves supplied
with the instrument. The operating ranges for the CO analyzer are 0-500 ppm
and 0-2000 ppm.
Specifications: Span stability -1% of full scale in 24 hours
Zero stability -1% of full scale in 24 hours
Ambient temperature range 32 °F to 120°F
Line voltage 115-15V rms
Response 90% of full scale in 0.5 or 2.5 sec.
Precision il% of full scale
Output 4-20 ma
Carbon dioxide. Carbon dioxide concentration is measured by a Beckman
Model 864 short path-length, non-dispersive infrared analyzer. This instrument
measures the differential in infrared energy absorbed from energy beams passed
through a reference cell (containing a gas selected to have minimal absorption
of infrared energy in the wavelength absorbed by the gas component of interest)
and a sample cell through which the sample gas flows continuously. The dif-
ferential absorption appears as a reading on a scale from 0 to 100 and is then
related to the concentration of the specie of interest by calibration curves
supplied with the instrument. The operating ranges for the C02 analyzer are
0-5% and 0-20%.
Specifications: Span stability ±1% of full scale in 24 hours
Zero stability tl% of full scale in 24 hours
Ambient temperature range 32°F to 120°F
Line voltage 115±15V rms
Response 90% of full scale in 0.5 or 2.5 sec.
Precision ±1% of full scale
Output 4-20 ma
KVB 4-15900-548
19
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Oxygen. The oxygen content of the flue gas sample is automatically
and continuously determined with a Teledyne Model 326A Oxygen analyzer.
Oxygen in the flue gas diffuses through a Teflon membrane and is reduced on
the surface of the cathode. A corresponding oxidation occurs at the anode
internally and an electric current is produced that is proportional to the
concentration of oxygen. This current is measured and conditioned by the
instrument's electronic circuitry to give a final output in percent O? by
volume for operating ranges of 0% to 5%, 0% to 10%, or 0% to 25%.
Specifications: Precision -1% of full scale
Response 90% in less than 40 sec.
Sensitivity 1% of low range
Linearity -1% of full scale
Ambient temperature range 32-125°F
Fuel cell life expectancy 40,000%-hours
Power requirement 115 VAC, 50-60 Hz, 100 watts
Output 4-20 ma
Hydrocarbons. Hydrocarbons are measured using a Beckman Model 402
hydrocarbon analyzer which utilizes the flame ionization method of detection.
The same is drawn to the analyzer through a heated line to prevent the loss
of higher molecular weight hydrocarbons. It is then filtered and supplied to
the burner by means of a pump and flow control system. The sensor, which is
the burner, has its flame sustained by regulated flows of fuel (40% hydrogen
plus 60% helium) and air. In the flame, the hydrocarbon components of the
sample undergo a complete ionization that produces electrons and positive ions.
Polarized electrodes collect these ions, causing a small current to flow throu^i
a circuit. This ionization current is proportional to the concentration of
hydrocarbon atoms which enter the burner. The instrument 'is available with
range selection from 5 ppm to 10% full scale as CH4.
Specifications: Full scale sensitivity, adjustable from 5 ppm CH4 to
10% CH4
Ranges: Range multiplier switch has 8 positions: XI
X5, X10, X50, X100, X500, XlOOO, and X5000. In
addition, span control provides continuously variable
adju ,ment within a dynamic range of 10:1
Response time 90% full scale in 0.5 sec.
Precision il% of full scale
Electronic stability ±1% of full scale for successive
identical samples
KVB 4-15900-548
20
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Reproducibility itl% of full scale for successive
identical samples
Analysis temperature: ambient
Ambient temperature 32°F to 110°F
Output 4-20 ma
Air requirements 350 to 400 cc/min of clean, hydro-
carbon-free air, supplied at 30 to 200 psig
Fuel gas requirements 75 to 80 cc/min of pre-mixed
fuel consisting of 40% hydrogen and 60% nitrogen
or helium, supplied at 30 to 200 psig
Electrical power requriements 120V, 60 Hz
Automatic flame-out indication and fuel shut-off valve
4.1.2 Recording Instruments
The Output of the four analyzers is displayed on front panel meters
and are simultaneously recorded on a Texas Instrument Model FLO4W6D four-pen
strip chart recorder. The recorder specifications are as follows:
Chart size 9- 3/4 inch
Accuracy ±0.25%
Line voltage 120V±10% at 60 Hz
Span step response: one second
4.1.3 Gas Sampling and Conditioning System
The gas sampling and conditioning system consists of probes, sample
lines, valves, pumps, filters and other components necessary to deliver a
representative, conditioned sample gas to the analytical instrumentation. The
following sections describe the system and its components . The entire gas
sampling and conditioning system shown schematically in Figure 4-1 is con-
tained in the emission test vehicle.
4.1.4 Gaseous Emission Sampling Techniques
Boiler access points for gaseous sampling are selected in the same
sample plane as are particulate sample points. Each probe consists of one-
half inch 316 stainless steel heavy wall tubing. A 100 micrometer Mott Metal-
lurgical Corporation sintered stainless steel filter is attached to each
probe for removal of particulate material.
KVB 4-15900-548
21
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i'l
.:
Ji
£C
.1
T!r5'
I«P^
.£1
io
^JQ.
-p
n
SJ .^
O 0 O i
«,
r.it.
i
^~
\
<" '[
m
f| <;";7;r
'
I
lid iwpl* m
Figure 4-1. Flow Schematic of Mobile Flue Gas Monitoring Laboratory
KVB 4-15900-548
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Gas samples to be analyzed for O2, CO2, CO and NO are conveyed to the
KVB mobile laboratory through 3/8 inch nylon sample lines. After passing
through bubblers for flow control, the samples pass through a diaphragm pump
and a refrigerated dryer to reduce the sample dew point temperature to 35°F.
After the dryer, the sample gas is split between the various continuous gas
monitors for analysis. Flow through each continuous monitor is accurately
controlled with rotometers. Excess flow is vented to the outside. Gas samples
may be drawn both individually and/or compositely from all probes during each
test. The average emission values are reported in this report.
4.2 SjJLFUR OXIDES (SOx) MEASUREMENT AND PROCEDURES
Measurement of SO2 and 803 concentrations is made by wet chemical
analysis using both the "Shell-Emeryville" method and EPA Method 6. In the
Shell-Emeryville method the gas sample is drawn from the stack through a
glass probe (Figure 4-2), containing a quartz wool filter to remove partlcu-
late matter, into a system of three sintered glass plate absorbers (Figure 4-3)
The first two absorbers contain aqueous isopropyl alcohol and remove the sul-
fur trioxide; the third contains aqueous hydrogen peroxide solution which
absorbs the sulfur dioxide. Some of the sulfur trioxide is removed by the
first absorber, while the remainder, which passes through as sulfuric acid
mist, is completely removed by the secondary absorber mounted above the first.
After the gas sample has passed through the absorbers, the gas train is purged
with nitrogen to transfer sulfur dioxide, which has dissolved in the first
two absorbers, to the third absorber to complete the separation of the two
components. The isopropyl alcohol is used to inhibit the oxidation of sulfur
dioxide to sulfur trioxide before it gets to the third absorber.
The isopropyl alcohol absorber solutions are combined and the sulfate
resulting from the sulfur trioxide absorption is titrated with standard lead
perchlorate solution using Sulfonazo III indicator. In a similar manner, the
hydrogen peroxide solution is titrated for the sulfate resulting from the
sulfur dioxide absorption.
The gas sample is drawn from the flue by a single probe made of
quartz glass inserted into the duct approximately one-third to one-half way.
KVB 4-15900-548
23
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Flue Wall
Asbestos Plug
Ball Joint
Vycor
Sample Probe
Pryometer
and
Thermocouple
Figure 4-2. SOx Sanple Probe Construction
Spray Trap
Dial Thermometer
Pressure Gauge
Volume Indica- \
tor \ ^4
Vapor Trap Diaphragm
Pump
Dry Test Meter
Figure 4-3. Sulfur Oxides Sampling Train
KVB 4-15900-548
24
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'11u> inlet end of tin' pi obe holds a i-udi t£ wool filter to ttunovt- pnr t icuJnti-
mat~t.fr. It. is important that t lie entire probe temper at ure )>. kept .ibovi-
the dew point of suit uric acid during sampling (minimum temper at ure ol
Jt-0°O) . This is accomplished by wrappinq the- probe with a heating tape.
EPA Method ti, which is an alternative- method for determining SO^
(Figure 4-4), employs an impinqer train consisting of a bubbler arid three
midqet impingers. The bubbler contains isopropariol. The first and second
impinqers contain aqueous hydroqen peroxide. The third impinger is left dry.
The quartz probe and filter used in the Shell-Emeryville method is also used
in Method 6.
Method 6 differs from Shell-Emeryville in that Method 6 requires
that the sample rate be proportional to stack gas velocity. Method 6 also
differs from Shell-Emeryville in that the sample train in Method 6 is purged
with ambient air, instead of nitrogen. Sample recovery involves containing
the solutions from the first- and second impingers. A 10 ml aliquot of
this solution is then titrated with standardized barium perchlorate.
Two repetitions of Shell-Emeryville and two repetitions of EPA
Method 6 were made during each test.
4.3 PARTICULATE MEASUREMENT AND PROCEDURES
Particulate samples are taken at the same sample ports as the gaseous
emission samples using a Joy Manufacturing Company portable effluent sampler
(Figure 4-5). This system which meets the EPA design specifications for
Test Method 5, Determination of Particulate Emissions from Stationary Sources
(Federal Register, Volume 36, No. 27, page 24888, December 23, 1971), is used
to perform both the initial velocity traverse and the particulate sample
collection. Dry particulates are collected in a heated case using first a
cyclone to separate particles larger than five micrometers and a 100 mm glass
fiber filter for retention of particles down to 0.3 micrometers. Condensible
particulates are collected in a train of four Greenburg-Smith impingers in an
ice water bath. The control unit includes a total gas meter and thermocouple
indicator. A pitot tube system is provided for setting sample flows to obtain
isokinetic sampling conditions.
KVB 4-15900-548
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PROBE (END PACKED
WITH QUARTZ OR
PYREX WOOL)
THERMOMETER
STACK WALL
MIDGET IMPINGERS
MIDGET BUBBLER
GLASS WOOL
SILICA GEL
DRYING TUBE
5
o il
:i
ICE BATH
THERMOMETER
NEEDLE VALVE
PUMP
SURGE TANK
Figure 4-4. EPA Method 6 Sulfur Oxide Sanpling Train
KVB 4-15900-548
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TEMPERATURE SENSOR
IMPINGER TRAIN OPTIONAL.MAY BE REPLACED
BY AN EQUIVALENT CONDENSER
CHECK
VALVE
VACUUM
LINE
to
HEATED AREA THERMOMETER
TEMPERATURE
SENSOR
FILTER HOLDER
PITOTTUBE
PROBE
REVERSETYPE
PITOTTUBE
IMPINGERS ICE BATH
(~\ C BY-PASS VALVE
PITOT MANOMETER
ORIFICE
THERMOMETERS
DRY GAS METER
AIRTIGHT
PUMP
Figure 4-5. EPA Method 5 Particulate Sanpling Train
KVB 4-15900-548
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All peripheral equipment is carried in the instrument van. This
includes a scale (accurate to -0.1 mg), hot plate, drying oven (212°F), high
temperature oven, desiccator, and related glassware. A particulate analysis
laboratory is set up in the vicinity of the boiler in a vibration-free area.
Here filters are prepared, tare weighed and weighed again after particulate
collection. Also, probe washes are evaporated and weighed in the lab.
4.4 PARTICLE SIZE DISTRIBUTION MEASUREMENT AND PROCEDURES
Particle size distribution was measured using two different methods.
These are the Brink Cascade Impactor and SASS cyclones. Each of these particle
sizing methods has its advantages and disadvantages.
Brink. The Brink cascade impactor is an in-situ particle sizing de-
vice which separates the particles into six size classifications. It has the
advantage of collecting the entire sample. That is, everything down to the
collection efficiency of the final filter is included in the analysis. It
has, however, some disadvantages. If the particulate matter is spatially
stratified within the duct, the single-point Brink sampler will yield
erroneous results. Unfortunately, the particles at the outlets of stoker
boilers may be considerably stratified. Another disadvantage is the instru-
ment's small classification range (0.3 to 3.0 micrometers) and its small sample
nozzle (1.5 to 2.0 mm maximum diameter). Both are inadequate for the job at
hand. The particles being collected at the boiler outlet are often as large
as the sample nozzle.
The sampling procedure is straight forward. First, the gas velocity
at the sample point is determined using a calibrated S-type pitot tube. For
this purpose a hand held particulate probe, inclined manometer, thermocouple
and indicator are used. Second, a nozzle size is selected which will main-
tain isokinetic flow rates within the recommended .02-.07 ftVmin rate at
stack conditions. Having selected a nozzle and determined the reguired flow
rate for isokinetics, the operating pressure drop across the impactor is
determined from a calibration curve. This pressure drop is corrected for
temperature, pressure and molecular weight of the gas to be sampled.
KVB 4-15900-548
28
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A sample is drawn at the predetermined AP for a time period which is
dictated by mass loading and size distribution. To minimize weighing errors,
it is desirable to collect several milligrams on each stage. However, to
minimize reentrainment, a rule of thumb is that no stage should be loaded
above 10 mg. A schematic of the Brink sampling train is shown in Figure 4-6.
SASS. The Source Assessment Sampling System (SASS) was not designed
principally as a particle sizer but it includes three calibrated cyclones
which can be used as such. The SASS train is a single point in-situ sampler.
Thus, it is on a par with cascade impactors. Because it is a high volume
sampler and samples are drawn through large nozzles (0.25 to 1.0 in.), it
has an advantage over the Brink cascade impactor where large particles are
involved. The cut points of the three cyclones are 10, 3 and 1 micrometers.
A detailed description of the SASS train is presented in Section 4-8.
4.5 COAL SAMPLING AND ANALYSIS PROCEDURE
Coal samples at Test Site K were taken during each test from the
unit's coal scale. The samples were processed and analyzed for both size
consistency and chemical composition. The use of the coal scale as a sampling
station has two advantages. It is close enough to the furance that the coal
sampled simultaneously with testing is representative of the coal fired
during the testing. Also, because of the construction of the coal scale, it
is possible to collect a complete cut of coal off the scales' apron feeder
thus insuring a representative size consistency.
In order to collect representative coal samples, a sampling tray
having a twenty pound capacity was custom built. The tray has the same width
as the apron feeder belt and can be moved directly under the belt's discharge
end to catch all of the coal over a short increment of time (approximately
five seconds).
The sampling procedure is as follows. At the start of testing one
increment of sample is collected from the apron feeder. This is repeated
several times during the test (three to five hours duration) so that a six
increment sample is obtained. The sample is then riffled using a Gilson Model
SP-2 Porta Splitter until two representative twenty pound samples are obtained.
KVB 4-15900-548
29
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PRESSURE TAP
FOR 0-20"
MAGNAHELIX
CYCLONE
STAGE 1
STAGE 2
STAGE 3
STAGE 4
STAGE 5
FINAL FILTER
EXHAUST
DRY GAS
METER
FLOW CONTROL
VALVE
ELECTRICALLY HEATED PROBE
DRYING
COLUMN
Figure 4-6. Brink Cascade Impactor Sampling Train
KVB 4-15900-548
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The sample to be used for sieve analysis is air dried overnight and
weighed. Drying of the coal is necessary for good separation of fines. If
the coal is wet, fines cling to the larger pieces of coal and to each other.
Once dry, the coal is sized using a six tray Gilson Model PS-3 Porta Screen.
Screen sizes used are 1", 1/2", 1/4", #8 and #16 mesh. Screen area per tray
is 14"xl4". Ihe coal in each tray is weighed on a triple beam balance to
the nearest 0.1 gram.
The coal sample for chemical analysis is reduced to 2-3 pounds by
further riffling and sealed in a plastic bag. All coal samples are sent to
Commercial Testing and Engineering Company, South Holland, Illinois. Each
sample associated with a particulate loading or particle sizing test is
given a proximate analysis. In addition, composite samples consisting of
one increment of coal for each test for each coal type receive ultimate
analysis, ash fusion temperature, mineral analysis, Hardgrove grindability
and free swelling index measurements.
4.6 ASH COLLECTION AND ANALYSIS FOR COMBUSTIBLES
The combustible content of flyash is determined in the field by KVB
in accordance with ASTM D3173, "Moisture in the Analysis Sample of Coal and
Coke" and ASTM D3174, "Ash in the Analysis Sample of Coal and Coke."
The flyash sample is collected by the EPA Method 5 particulate sample
train while sampling for particulates. The cylcone catch is placed in a desic-
cated and tare-weighed ceramic crucible. The crucible with sample is heated
in an oven at 230°F to remove its moisture. It is then desiccated to room
temperature and weighed. The crucible with sample is then placed in an
electric muffle furnace maintained at a temperature of 1400°F until ignition
is complete and the sample has reached a constant weight. It is cooled in a
desiccator over desiccant and weighed. Combustible content is calculated as
the percent weight loss of the sample based on its post 230°F weight.
At Test Site K the bottom ash samples were collected in several in-
crements from the stoker ash pit at completion of testing. These samples
were mixed, quartered, and sent to Commercial Testing and Engineering Company
for combustible determination. Multiclone ash samples were taken from ports
KVB 4-15900-548
31
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near the base of the multiclone hopper. This sample, approximately two
quarts in size, was sent to Commercial Testing and Engineering Company for
combustible determination.
4.7 BOILER EFFICIENCY EVALUATION
Boiler efficiency is calculated using the ASME Test Form for Abbre-
viated Efficiency Test, Revised, September, 1965. The general approach to
efficiency evaluation is based on the assessment of combustion losses. These
losses can be grouped into three major categories: stack gas losses, com-
bustible losses, and radiation losses. The first two groups of losses are
measured directly. The third is estimated from the ABMA Standard Radiation
Loss Chart.
Unlike the ASME test in which combustible losses are lumped into one
category, combustible losses are calculated and reported separately for com-
bustibles in the bottom ash and combustibles in the flyash leaving the boiler.
4.8 TRACE SPECIES MEASUREMENT
The EPA (IERL-RTP) has developed the Source Assessment Sampling
System (SASS) train for the collection of particulate and volatile matter in
addition to gaseous samples (Figure 4-7). The "catch" from the SASS train
is analyzed for polynuclear aromatic hydrocarbons (PAH) and inorganic trace
elements.
In this system, a stainless steel heated probe is connected to an
oven module containing three cyclones and a filter. Size fractionation is
accomplished in the series cyclone portion of the SASS train, which incor-
porates the cyclones in series to provide large quantities of particulate
matter which are classified by size into three ranges:
A) >10 ym E, 3 urn to 10 urn C) 1 ym to 3 ym
Together with a filter, a fourth cut (<1 ym) is obtained. Volatile organic
material is collected in an XAD-2 sorbent trap. The XAD-2 trap is an integral
part of the gas treatment system which follows the oven containing the cyclone
system. The gas treatment system is composed of four primary components:
KVB 4-15900-548
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Convection
CO
LJ
Miter
Or I rice AH,
ugnehel
-------
the gas conditioner, the XAD-2 organic sorbent trap, the aqueous condensate
collector, and a temperature controller. The XAD-2 sorbent is a porous poly-
mer resin with the capability of absorbing a broad range of organic species.
Some trapping of volatile inorganic species is also anticipated as a result
of simple iinpaction. Volatile inorganic elements are collected in a series
of impingers. The pumping capacity is supplied by two 10 cfm high volume
vacuum pumps, while required pressure, temperature, power and flow conditions
are obtained from a main controller.
KVB 4-15900-548
34
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5.0 TEST RESULTS AND OBSERVATIONS
This section presents the results of tests performed on Boiler K.
Observations are made regarding the influence on efficiency and on gaseous
and particulate emissions as the control parameters are varied. Eighteen
defined tests were conducted over a one-month period to develop this data.
Tables 2-1 and 2-2 in the Executive Summary, and Tables 5-22 through 5-25
at the end of this section are included for reference.
5.1 OVERFIRE AIR
The overfire air system in Boiler K consisted of a single row of
air jets on the front water wall. Air flow to these jets was controllable
up to a maximum of about 7.5 j.nches water pressure. However, normal
operating procedure at this site was to maintain overfire air flow at about
2.5 inches water pressure over the full load range.
In order to investigate the effect of overfire air on emissions
and efficiency, three test series were conducted in which overfire air was
the primary variable. Figure 5-1 shows the overfire air pressure for each
test as a function of grate heat release. The high overfire air tests are
identified in this figure and in all subsequent figures by solid symbols.
The test results are presented in Table 5-1 and discussed in the
following paragraphs. In general, increased overfire air effectively dropped
the flyash combustible level, the carbon monoxide concentration and the particu-
late mass loading, but had little or no effect on the nitric oxide concentra-
tion or the boiler efficiency.
5.1.1 Particulate Loading vs Overfire Air
Uncontrolled particulate mass loading dropped an average 20% when
overfire air pressure was increased. Although 20% is significant, there is
a degree of uncertainty associated with this number. The data, presented in
Table 5-2, shows that in one of the five test sets, particulate mass loading
actually increased 13% when overfire air pressure increased.
KVB 4-15900-548
35
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HIGH OFA
NORMAL
OFA
''''-
HIGH OVERFIRE AIR DATA POINTS ARE REPRESENTED BY
SOLID SYMBOLS IN ALL PLOTS IN THIS REPORT
T
I
I
0
100.0 200.0 300.0 400.0 500.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
: HflSHED
: UNWflSHED
CRUSHED
FIG. 5-1
OVERFIRE flIR
TEST SITE K
VS. GRflTE HEflT RELEflSE
4-15900-548
36
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TABLE 5-1
EFFECT OF OVERFIRE AIR ON EMISSIONS AND EFFICIENCY
TEST SITE K
LOW LOAD
TEST No.
Description
FIRING CONDITIONS
Over fire Air Pressure, "H2O
Load, % of Capacity
Grate Heat Release, 103Btu/hr-ft2
Coal Description
Coal Fines, % Passing 1/4"
Excess Air, %
UNCONTROLLED EMISSIONS
Particulate Loading, lb/106Btu
Combustible Loading, lb/106Btu
Inorganic Ash Loading, lb/10^Btu
Combustibles in Flyash, %
Combustibles in Bottom Ash, %
02, % (dry)
C02, % (dry)
CO, ppm @ 3% O2
NO, lb/106Btu
CONTROLLED EMISSIONS '
Particulate Loading, lb/106Btu
Dust Collector Efficiency, %
HEAT LOSSES, %
Dry Gas
Moisture in Fuel
H2O from Combustion of H2
Combustibles in Flyash
Combustibles in Bottom Ash
Radiation
Unmeasured
Total Lossos
Boiler Efficiency
FULL
I 1
Low
OFA
2.5
97
401
Washed
22
67
1.240
0.399
0.841
32.2
27.6
8.8
9.6
537
0.326
0.199
84.0
11.01
0.49
4.10
0.57
1.83
0.64
1.50
20.14
79.86
LOAD, HIGH O2
4
Low
OFA
2.5
100
405
Washed
22
59
0.758
0.278
0.480
36.7
47.6
8.2
9.7
275
0.309
0.148
80.5
10.58
0.67
4.07
0.40
2.63
0.65
1.50
20.47
79.53
6I
High
OFA
7.5
95
380
Washed
16
60
0.655
0.193
0.462
29.4
60.0
8.3
9.6
70
0.321
0.134
79.5
11.41
0.64
4.23
0.28
5.48
0.65
1.50
24.19
75.81
FULL
1 5
Low
OFA
2.6
96
386
Washed
16
51
0.755
0.308
0.447
40.8
69.1
7.5
10.0
208
0.285
0.158
79.1
9.82
0.54
4.04
0.44
6.72
0.65
1.50
23.71
76.29
LOAD, MED O2
7
High
OFA
5.0
101
399
Washed
21
48
0.850
0.230
0.621
27.0
37.9
7.2
10.6
126
0.294
0.129
84.8
10.23
0.71
4.17
0.33
2.49
0.62
1.50
20.05
79.95
B\
High
OFA
4.9
100
.428
Washed
19
49
0.639
0.188
0.451
29.4
39.5
7.3
10.4
105
0.320
0.112
82.5
10.55
0.69
4.15
0.23
2.02
0.62
1.50
19.80
80.20
NORM
1 2
Low
OFA
1.9
50
201
Washed
19
174
0.737
0.265
0.472
36.0
23.9
13.7
6.0
339
0.311
0.190
74.2
16.37
0.63
4.14
0.39
1.14
1.22
1.50
25.39
74.61
02
9 1
High
OFA
4.9
41
185
Washed
31
149
0.477
0.114
0.363
24.0
75.5
13.0
6.1
187
0.303
0.144
69.8
12.07
0.54
4.04
0.16
15.70
1.50
1.50
35.51
64.49
KVB 4-15900-548
37
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TABLE 5-2
PARTICULATE LOADING VS OVERFIRE AIR
Test Uncontrolled Particulate
Controlled Participate
No. Overfire Air lb/106Btu % Change Ib/lO&Btu% Change
1 Low (2.5" H20) 1.24 0.20
6 High (7.5" H2O) 0.66 - 47 0.13 _ 33
4 Low (2.5" H20) 0.76 0.15
6 High (7.5" H20) 0.66 - 14 0.13 - 9
5 Low (2.6" H20) 0.76 0.16
7 High (5.0" H2O) 0.85 + 13 0.13 - 18
5 Low (2.6" H20) 0.76 0.16
8 High (4.9" H2O) 0.64 - 15 0.11 _ 21
2 Low (1.9" H20) 0.74 0.19
9 High (4.9" H2O) 0.48 - 35 0.14 - 24
The controlled particulate mass loading (dust collector outlet) showed
a similar reduction due to increased overfire air pressure. The average re-
duction at this location was 21%, and the data exhibited greater consistency than
at the boiler outlet.
The measured particulate reductions can be attributed in part to a re-
duction in the combustible fraction of the flyash. The combustible fractions
were reduced an average of 25% in those- same tests.
Test data are graphically presented in Figures 5-3 and 5-4 of section
5.2. High overfire air tests in these figures are indicated by solid symbols.
5.1.2 Nitric Oxide vs Overfire Air
The nitric oxide (NO) concentration was not influenced by the variable
overfire air. This conclusion is best illustrated by Figure 5-7 of section 5 2
which shows the high overfire air data to be of the same magnitude as the low
overfire air data under similar conditions of oxygen and grate heat release
KVB 4-15900-548
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5.1.3 Carbon Monoxide vs Overfire Air
Carbon monoxide (CO) dropped an average 60% when overfire air pressure
was increased. This data is presented in Table 5-3, and is graphically
illustrated in Figures 5-9 and 5-10 of Section 5.2.
TABLE 5-3
CARBON MONOXIDE VS OVERFIRE AIR
Carbon Monoxide
ppm @ 3% Oy
Test
No.
1
4
6
5
7
8
2
9
Overfire Air
("H,0)
Low
Low
High
Low
High
High
Low
High
(2.5)
(2.5)
(7.5)
(2.6)
(5.0)
(4.9)
(1.9)
(4.9)
537
275
70
208
126
105
339
187
5.1.4 Boiler Efficiency vs Overfire Air
The heat loss due to combustibles in the flyash decreased as overfire
air increased. However, this efficiency improvement was small, on the order of
0.2 to 0.3% of the heat input. On this unit, boiler efficiency was reduced by
energy loss due to combustibles in the bottom ash which were on the order of
2 to 7%. Since no consistent correlation was found between combustibles in the
bottom ash and overfire air, it is concluded that boiler efficiency was not
significantly affected by changes in the overfire air pressure.
Data supporting this conclusion is presented in Table 5-4. The data
are graphically presented in Figure 5-11 (Combustibles in Flyash), Figure 5-13
(Combustibles in Bottom Ash), and Figures 5-14 and 5-15 (Boiler Efficiency) of
Section 5.2.
KVB 4-15900-548
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TABLE 5-4
BOILER EFFICIENCY VS OVERFIRE AIR
Test
No.
1
4
6
5
7
8
2
9
Overfire
Air Heat Loss Due to
( "H2O) Comb in Flyash , %
Low
Low
High
Low
High
High
Low
High
(2
(2
(7
(2
(5
(4
(1
(4
.5}
-5)
.5)
-6)
.0)
.9)
. 0
.9)
0.
0.
0.
0.
0.
0.
0.
0.
57
40
28
44
33
23
39
16
Heat Loss Due to
Comb in Bottom Ash ,
1
2
5
6
2
2
1
15
.83
.63
.48
.72
.49
.02
.14
.70
% Boiler
% Efficiency
79,86
79
75
76
79
80
74
64
.53
.81
.29
.95
.20
.61
.49
5.2 EXCESS OXYGEN AND GRATE HEAT RELEASE
Tests were conducted on Boiler K at loads of 50%, 75% and 100% of the
unit's design capacity. At each load, tests were conducted within a range of
about 2% excess oxygen. This section profiles emissions and boiler efficiency
as a function of these two variables.
The units chosen to present this data are percent oxygen (dry), and
grate heat release in Btu/hr-ft2. Grate heat release, which is proportional to
the unit's steam loading, was chosen because it provides a common basis for
comparing this unit's emissions with those of other units tested in this program
The four high overfire air tests are indicated on each plot in this
section by solid symbols. Most of the plots also differentiate the three coals
by means of distinct symbols.
5.2.1 Excess Oxygen Operating Levels
Figure 5-2 depicts the various conditions of grate heat release and
excess oxygen under which tests were conducted on Boiler K. Nine tests were
conducted at full load which corresponds to about 400,000 Btu/hr-ft2 grate are
Five tests were conducted at 75% of capacity or 300,000 Btu/hr-ft2, and four
tests at 50% of capacity or 200,000 Btu/hr-ft2.
KVB 4-15900-548
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SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SHADED AREA EMPHASIZES TREND.
I
1
100.0 200.0 300.0 400.0 500.0
GRflTE HERT RELEflSE 1000 BTU/HR-SQ FT
; WflSHED
: UNHfiSHEO
: CRUSHED
FIG. 5-2
EXCESS OXYGEN
TEST SITE K
VS. GRRTE HERT RELERSE
4-15900-546
41
-------
Excess oxygen varied within a band which was about 2"& C>2 wide, as
previously mentioned, and which decreased sharply as load, or grate heat release,
was increased. The shaded area of Figure 5-2 accentuates this trend.
The minimum full load excess oxygen tested was 6%, or 37% excess air.
Excess air has been determined for each test and may be found in Table 2-2 of
the Executive Summary.
5.2.2 Particulate Loading vs Oxygen and Grate Heat Release
The particulate mass loading data obtained at the boiler outlet before
the mechanical dust collector is presented as a function of grate heat release
in Figure 5-3. This data is often called the uncontrolled particulate loading.
The data is seen to correlate strongly with coal properties. The
washed coal exhibited the lowest particulate mass loadings as shown by the shaded
area in Figure 5-3. The crushed coal particulate loading was 58% greater than
that of the washed coal at full load. This is presumably a direct result of the
increase in fines from 20 to 44% passing 1/4" square mesh screen. The unwashed
coal had the greatest particulate loading, nearly three times that of the
washed coal at full load. The unwashed coal did not have significantly greater
fines than the washed coal, but it contained more impurities which apparently
were readily carried over as flyash. The unwashed coal contained 14% ash during
the full load test as compared to 4% ash for the full load crushed coal test
and washed coal tests.
The uncontrolled particulate loading is shown in Figure 5-3 to increase
in magnitude as grate heat release increases. This was true for all three
coals.
Uncontrolled particulate loading was not found to correlate with the
small variations in excess oxygen encountered during testing. However, this is
due to a lack of supportive data and does not preclude the likelihood of such
a correlation.
The controlled particjlate data, i.e., that data obtained after the
mechanical dust collector, is presented as a function of grate heat release
in Figure 5-4. The controlled and uncontrolled particulate mass loadings were
obtained simultaneously during each of the first seventeen tests on Boiler K.
KVB 4-15900-548
42
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UNWASHED
COAL
CRUSHED
COAL
\
WASHED
COAL
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SHADED AREA AND SOLID LINES EMPHASIZE DATA TRENDS,
100.0 200.0 300.0 400.0 500.0
GRRTE HEflT RELERSE 1000 BTU/HR-SQ FT
UflSHED
: UNWRSHED
' CRUSHED
FIG. 5-3
BOILER OUT PflRT.
TEST SITE K
VS. GRRTE HEflT RELERSE
4-15900-548
43
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QQ
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SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SOLID LINES EMPHASIZE DATA TRENDS.
T
T
0
100.0 200.0 300.0 400.0 500.0
GRRTE HEflT RELEflSE 1000 BTU/HR-SQ FT
: HfiSHED -j- : UNURSHED
" CRUSHED
FIG. 5-4
MULT I CLONE OUT PRRT. VS. GRflTE HEflT RELERSE
TEST SITE K
t-15900-548
44
-------
The effect of coal type is not as pronounced after the collector as it
was before the collector. The unwashed coal still exhibits greater particulate
mass loadings than the crushed coal. The washed coal data, however, are
cattered. This scatter simply reflects variations in the efficiency of the
dust collector which may or may not be related to coal properties or other
operating parameters.
The controlled particulate loading decreases as grate heat release
increases. This is probably a result of increased mechanical dust collector
efficiency as pressure drop and velocity through the cyclone tubes increases.
As with the uncontrolled particulate mass loading, data are limited
regarding the effect of excess oxygen on controlled particulate loading. How-
ever, there is clearer evidence at this sample location that increased oxygen,
over the limited range tested, does increase the particulate loading. This
data is presented for the three load ranges in Figure 5-5. The full load data
are shaded to emphasize the trend.
Percent ash carryover was determined for each test and is presented
in Table 5-5. The average ash carryover for the seventeen tests was 16-4%.
Note that in this report, ash carryover is defined as the amount of non-contous-
tible, non-volatile material found in the flyash compared with the amount of
the same material found in the coal, both corrected to a heat input basis. In
other words, combustibles in the flyash are excluded.
Stack opacity is related to particulate loading and is, therefore,
included in this section. Stack opacity was measured by a transmissometer and
the data are presented in Figure 5-6. It is observed that the crushed coal,
which contained the greatest fraction of fines, increased the opacity sharply
as grate heat release increased. The unwashed coal produced low opacity
levels of the same general magnitude as the washed coal. Opacity did not cor-
relate with controlled particulate loading.
5.2.3 Nitric Oxide vs Oxygen and Grate Heat Release
Nitric oxide (NO) concentration was measured during each test in units
of parts per million (ppm) by volume. The units have been converted to Ib N02/106
Btu on a heat input basis so that they will be more easily compared with existing
and proposed emission standards. Table 2-2 in the Executive Summary lists the
KVB 4-15900-548
45
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QC
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0_
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CM
§
§
C\J
O
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ID
O
O
O
ID '
FULL LOAD
TESTS
SOLID SYMBOLS REPRESENT HIGH OVERFIRE TESTS.
SHADED AREA EMPHASIZES TREND IN HIGH LOAD DATA.
0
4.00 6.00
EXCESS OXYGEN
8.00 10.00
PERCENT (DRY)
12.00
: LOW LOHD
: NED LOTO
; HIGH LOflO
FIG. 5-5
MULTICLONE OUT PRRT
TEST SITE K
VS. EXCESS OXYGEN
1-15900-548
46
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12
16
15
17
TABLE 5-5
ASH CARRYOVER VS FIRING CONDITIONS
FIRING CONDITIONS
Test
No.
1
4
5
6
7
8
11
3
10
2
9
Coal
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Load
%
100
100
100
100
100
100
100
75
75
50
50
02
%
8.8
8.2
7.5
8.3
7.2
7.3
6.4
10.9
10.1
13.7
13.0
OFA
ii
2.5
2.5
2.6
7.5
5.0
4.9
2.5
2.2
2.5
1.9
4.9
Pines
%
22
22
16
16
21
19
21
20
15
19
31
Ash in Coal
lb/106Btu
4.21
2.51
2.56
4.12
3.49
2.62
2.63
3.04
3.31
3.99
3.94
Ash in Flyash
lb/10&Btu
0.84
0.48
0.45
0.46
0.62
0.45
0.39
0.54*
0.47
0.47
0.36
% Ash
Carryover
20
19
17
11
18
17
15
18*
14
12
9
Unwashed
Unwashed
Unwashed
Crushed
Crushed
Crushed
100
75
50
100
75
50
8.5
11.6
12.9
6.0
10.0
10.8
2.5
2.5
3.5
3.8
2.5
2.0
22
32
23
39
54
39
11.86
6.70
6.67
3.19
3.53
4.09
1.43
1.33
0.87
0.77
0.76
0.48
12
20
13
24
21
12
AVG 16±4%
*Average combustible content, 32.1%, was
assumed for Test No. 3.
nitric oxide data in units of ppm for the convenience of those who prefer these
units.
Figure 5-7 presents the nitric oxide data as a function of grate heat re-
lease under the various excess oxygen conditions encountered during testing.
Nitric oxide is relatively invariant with grate heat release on this unit when
excess oxygen is not held constant. Average nitric oxide for each of the three
load ranges is presented in Table 5-6.
KVB 4-15900-548
48
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co o
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G-+-
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AVG. = 0,319
LB N02/106Btu
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SOLID LINE REPRESENTS AVERAGE VALUE OF DATA.
0
100.0 200.0 300.0 400.0 500.0
GRflTE HERT RELERSE 1000 BTU/HR-SQ FT
HUSHED
: UNUftSHED
; CRUSHED
FIG. 5-7
NITRIC OXIDE
TEST SITE K
VS. GRRTE HERT RELERSE
4-15900-548
49
-------
TABLE 5-6
AVERAGE NITRIC OXIDE CONCENTRATION VS LOAD
100% Load
75% Load
50% Load
Number of
Data Points
9
5
4
Nitric Oxide
Ib NO2/106Btu
0.316
0.316
0.330
Nitric Oxide
ppm @ 3% 0^
232
232
240
Figure 5-8 presents the nitric oxide data as a function of excess
oxygen. In this figure, nitric oxide is shown to increase with increasing
excess oxygen at constant load. At full load, nitric oxide increases by
0.033 lb/106Btu for each one percent increase in oxygen. A line of this
slope has been drawn through the data.
Nitric oxide concentrations were not altered by the changes in coal.
The fact that crushed coal has the lowest nitric oxide concentrations in Figure
5-7 is due to operation at lower 02- At similar load and excess oxygen the
nitric oxide concentrations were essentially equivalent.
5.2.4 Carbon Monoxide vs Oxygen and Grate Heat Release
The carbon monoxide (CO) concentration was monitored during each test.
The data are presented in Figure 5-9 as a function of grate heat release, and
in Figure 5-10 as a function of excess oxygen.
Carbon monoxide was found to be highly variable within the general
range of 100 to 500 ppm. No trends were observed for carbon monoxide either
as a function of load or excess oxygen within the limits examined. Coal type
was also found to have no impact. The largest observed influence on carbon
monoxide concentration was overfire air, which effectively reduced the CO to its
lowest levels.
KVB 4-15900-548
50
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HIGH LOAD TREND LINE DETERMINED BY LINEAR REGRESSION ANALYSIS
OF DATA. SLOPE = .033 LB NO/1Q6BTU PER 1% 02- SOLID SYMBOLS
REPRESENT HIGH OVERFIRE AIR TESTS.
4.00 6.00
EXCESS OXYGEN
A : LOH LORD -f- : MED LORD
FIG. 5-8
NITRIC OXIDE
TEST SITE K
8.00 10.00 12.00
PERCENT (DRY)
: HIGH LORD
VS. EXCESS OXYGEN
4-15900-548
51
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SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
r 1 1 1 1
100.0 200.0 300.0 400.0 500.0
GRflTE HEflT RELERSE 1000 BTU/HR-SQ FT
0
; HASHED
-f I UNHRSHED
: CRUSHED
FIG. 5-9
CflRBON MONOXIDE
TEST SITE K
VS. GRflTE HERT RELEflSE
4-15900-548
52
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SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
+
A
/ / I I
4.00 6.00
EXCESS OXYGEN
£ ; LOU LORD + : ICO LORD
FIG. 5-10
CflRBON MONOXIDE
TEST SITE K
8.00 10.00 12.00
PERCENT (DRY)
: HIGH LORD
VS. EXCESS OXYGEN
4-15900-548
53
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5.2.5 Combustibles in the Ash vs Grate Heat Release
Ash samples were collected from the bottom ash hopper, the dust
collector hopper, and the boiler outlet flue gas during each test. Combustible
content of each ash sample was determined. The data are plotted as a function
of grate heat release in Figures 5-11, 5-12 and 5-13, and section 5.7, Table
5-24, lists the complete combustible data for Boiler K.
Figure 5-11 presents the percent combustible found in the boiler outlet
flyash. Separate symbols are used for the three coals, and solid symbols in-
dicate the high overfire air tests.
The flyash averaged 32% combustible matter and shows a slight increasing
trend with increasing load. Coal type did not correlate with combustible
level. Excess oxygen, although not shown here, also did not correlate. Over-
fire air was the only test variable at this site which changed the flyash com-
bustible level. High overfire air (solid symbols) is seen to have produced the
lowest combustible levels.
Figure 5-12 presents the percent combustibles found in the dust
collector hopper ash. This ash is the same as the boiler outlet flyash but
with the finer particles separated out. Combustibles averaged 29%, were
constant with load, and were unaffected by changes in overfire air, excess air,
or coal. ' - - -
Figure 5-13 presents the percent combustible found in the bottom ash.
Combustibles range from 21 to 75% and average 42%. This appears to be unusually
high for an overfeed traveling grate stoker where combustible levels usually
average closer to 20%. Because of the scatter in the data it is impossible to
pick out trends with the variables coal, load, excess oxygen and overfire air.
5.2.6 Boiler Efficiency vs Grate Heat Release
Boiler efficiency was determined for each test using the ASME heat
loss method. The boiler efficiencies are plotted in Figure 5-14 as a function
The average is based on data from previous overfeed stokers tested
under this contract. Site designation and bottom ash combustible averages were;
Site D - 20%; Site H - 16%; Site I - 29%; Site J - 21%.
KVB 4-15900-548
54
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o _
o
LU
o
00
O
d
CD
CO
o
o
ID
O
cc
LU
O
DO
o
CD _
CM
0
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS,
SHADED AREA EMPHASIZES DATA TREND.
vf
I
I
I
100.0 200.0 300.0 400.0 500.0
GRRTE HEflT RELEflSE 1000 BTU/HR-SQ FT
URSHED
4- : UNSHED
: CRUSHED
FIG. 5-11
BOILER OUT COMB.
TEST SITE K
VS. GRRTE HERT RELERSE
4-15900-548
55
-------
UJ
u
oc
LlJ
00
32
O
i I
UJ
O
I. '
o
C )
o
CD
o
o
CD
( /
O _
C\J
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS
SHADED AREA EMPHASIZES DATA TREND.
I
I
I
I
r
100.0 200.0 300.0 400.0 500.0
GRflTE HERT RELEflSE 1000 BTU/HR-SQ FT
UH ,Ht(j
UNMRSHED
' CRUSHED
FIG. 5-12
MULTICLONE OUT COMB.
TEST SITE K
VS. GRRTE HERT RELERSE
4-15900-548
-------
o
CD
CD
O
O
CO
LU
CD O
2H >
o o
CJ **-
en
cc
o
CD
o
o
Ovl
0
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS
O
T
T
T
T
100.0 200.0 300.0 400.0 500.0
GRflTE HERT RELEflSE 1000 BTU/HR-SQ FT
: URSHED
-f : UNSHED
: CRUSHED
FIG. 5-13
BOTTOM RSH COMB.
TEST SITE K
VS. GRflTE HEflT RELEflSE
4-15900-5-48
57
-------
o
o
LO
OO
O
O
O
00
oc o
LU O
0- '-I
in
r»
>-
o
P-i
^ °^
_
LU
85 o
to
o
CD
MEASURED BOILER EFFICIENCY
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS
0
100.0 200.0 300.0 400.0 500.0
GRflTE HEflT RELERSE 1000 BTU/HR-SQ FT
: URSHEO
: UNURSHED
CRUSHED
FIG. 5-14
BOILER EFFICIENCY
TEST SITE K
VS. GRRTE HEflT RELERSE
4-15900-548
58
-------
of grate heat release, and a listing of all the heat loss data may be found
in Section 5.7, Table 5-23.
The major heat loss factor affecting boiler efficiency at this site
was the combustible heat loss, specifically the combustible heat loss in the
bottom ash. It has already been mentioned that bottom ash combustible levels
were considerably higher at Site K than at previously tested sites with similar
uiproent. rpj-je possibility exists that bottom ash samples were not
representative at this site. Therefore, boiler efficiency has also been
determined using an assumed 20% combustibles in the bottom ash. These data are
presented in Figure 5-15 and in Table 5-7. The reader is advised to use his
own judgement in interpreting the bottom ash combustible heat loss.
Table 5-7 presents the average boiler efficiency and heat loss data
obtained at Site K for each of the three test loads. Boiler efficiency was
greatest at full load where it averaged 78.4% (80.3% if 20% bottom ash com-
bustibles is assumed).
TABLE 5-7
BOILER EFFICIENCY VS LOAD
AVERAGE HEAT LOSSES, %
100%
75%
50%
Load
Load
Load
Dry
10
12
13
Gas
.61
.71
.68
Flyash
Combustibles
0
0
0
.48
.52
.35
Bottom Ash
Combustibles
3.65
2.52
8.41
(1
(1
(2
.69)*
.45)
79)
Other
6.80
7.00
7.40
% BOILER
EFFICIENCY
78.37
77.25
70.16
(80.33)*
(78.32)
(75.78)
* Data in parenthesis are based on 20% combustibles by
weight in bottom ash.
KVB 4-15900-548
59
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o
o
in
o
o
o
o
00
cc o
LU O
.
in
o
5 8
..
O
CD
BOILER EFFICIENCY ASSUMING 20' COMBUSTIBLES IN BOTTOM ASH
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SHADED AREA AND SOLID LINE EMPHASIZE DATA TRENDS,
100.0 200.0 300.0 400.0 500.0
GRflTE HEflT RELEflSE 1000 BTU/HR-FT SO
; URSHED
-f : UNURSHED
; CRUStCD
FIG. 5-15
BOILER EFFICIENCY
TEST SITE K
VS. GRRTE HERT RELEflSE
4-15900-548
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5.3 COAL PROPERTIES
Background information on the three forms of coal tested was given
in Section 3.4. This Section will discuss the chemical and physical properties
of these coals, and their observed influence on boiler emissions and efficiency.
5.3.1 Chemical Composition of the Coals
Representative coal samples were obtained during each test as described
in Section 4.5. A proximate analysis was obtained on each sample. In addition,
an ultimate analysis and mineral analysis of the ash were obtained on one
santple of each coal for purposes of combustion calculations.
The average proximate analysis for the three coals are compared on a
heating value basis in Table 5-8. Such a comparison is often more meaningful
than percentage by weight. This comparison shows that the unwashed coal con-
tains more than two and one-half times the ash of the washed coal. This high
ash content is the characteristic which differentiates it from the other two
coals. The crushed coal differs primarily in its fines, a property discussed
in the next subsection. Thus, the three coals each have their distinguishing
characteristics.
TABLE 5-8
COAL PROPERTIES CORRECTED TO A CONSTANT 106 BTU BASIS
Moisture, lb/106Btu
Ash, lb/106Btu
Volatile, lb/106Btu
Fixed Carbon, lb/106Btu
Sulfur, lb/106Btu
Washed
Coal
Unwashed
Coal
Crushed
Coal
4.9
3.1
28.4
39.4
0.8
5
8
27
4'N
0
.1
.3
.4
.6
.8
5.7
3.6
28.3
39.4
1.0
The analysis of each coal sample is given in Tables 5-9, 5-10, 5-11,
and 5-12.
KVB 4-15900-548
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TABLE 5-9
FUEL ANALYSIS - ALABAMA BRILLIANT COAL (WASHED)
TEST SITE K
N)
TEST NO. 01
PROXIMATE (As Rec)
% Moi sture 5 . 34
* Ash 5.55
* Volatile 37.85
* Fixed Carbon 51.26
Btu/Lb 13188
% Sulfur 1.14
ULTIMATE (As Rec)
% Moisture
% Carbon
Hydrogen
Nitrogen
Chlorine
Sulfur
Ash
Oxygen (Diff)
ASH FUSION (Red)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY INDEX
FREE SWELLING INDEX
FOULING INDEX
SLAGGING INDEX
02 03 04 05 06 07 08 09 10 11 18 AVG
7.25 6.45 7.40 6.00 7.13 7.63 7.44 5.99 5.41 6.44 G . 80 6.49
5.17 4.03 3.32 3.44 5.30 4.55 3.45 5.19 4.44 3.51 3.91 4.14
39.31 37.58 38.10 38.15 36.20 36.86 36.53 37.04 37.71 37.37 37.42 37.46
48.27 51.94 51.18 52.41 51.37 50.96 52.58 51.78 52.44 52.68 51.87 51.91
12942 13261 13209 13438 12868 13023 13170 13171 13397 13348 13168 13237
0.29 1.44 1.03 1.03 2.67 0.91 0.86 0.95 1.13 1.21 1.39 1.11
6.80
73.85
5.00
1.55
0.07
1.39
3.91
7.43
2100°F
2280°f
2310°F
2600°F
40
1-1/2
0.12
0.69
STD
DEV
0.82
0.78
0.53
0.62
125
0.19
KVB 4-15900-548
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TABLE 5-10
FUEL ANALYSIS - ALABAMA, BRILLIANT COAL (UNWASHED)
TEST SITE K
TEST NO.
PROXIMATE (As Rec)
% Moisture
% Ash
% Volatile
% Fixed Carbon
Btu/Lb
% Sulfur
ULTIMATE (As Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (Diff)
ASH FUSION (Red)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
12
13
5.99 6.59
8.40 8.35
34.48 33.70
51.13 51.36
14
6.00
13.96
32.88
47.16
COMP
AVG
4 . 76 6 .19
7.98 10.24
34.87 33.69
52.39 49.88
12601 12468 11770 12768 12280
1.19 0.96 0.88 1.10 1.01
4.76
72.21
4.68
1.44
0.05
10
98
STD
DEV
0.34
3.22
0.80
2.36
4.46
0.16
7.78
2110°F
2470
2510
2700+
42
KVB 4-15900-548
63
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TABLE 5-11
FUEL ANALYSIS - ALABAMA, BRILLIANT COAL (CRUSHED)
TEST SITE K
TEST NO.
PROXIMATE (As Rec)
% Moisture
% Ash
% Volatile
% Fixed Carbon
Btu/Lb
% Sulfur
ULTIMATE (As Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (Diff)
ASH FUSION (As Rec)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
15
16
7.97 6.82
4.57 4.19
36.85 37.23
50.61 51.76
12936
1.13
13148
1.35
17
7.27
5.28
36.07
51.38
12897
1.44
COMP AVG
5.84 7.35
4.15 4.68
37.53 36.72
52.48 51.25
13284
0.94
5.84
74.25
4.97
1.42
0.06
0.94
4.15
8.37
2190°F
2330
2360
2610
40
2
12994
1.31
STD
DEV
0.58
0.55
0.59
0.59
135
0.16
KVB 4-15900-548
64
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TABLE 5-12
MINERAL ANALYSIS OF COAL ASH
TEST SITE K
Coal
Mineral Analysis of Ash
Silica, SiO2
Alumina, A1203
Titania,
Ferric Oxide, FeO3
Lime , CaO
Magnesia, MgO
Potassium Oxide, K2O
Sodium Oxide,
Sulfur Trioxide , 503
Phos Pentoxide,
Undetermined
Alkalies as Na?O
Dry Coal Basis
Silica Value
Base: Acid Ratio
T250 Temperature
Sulfur Forms
% Pyritic Sulfur
% Sulfate Sulfur
% Organic Sulfur
Alabama
Washed
38.35
26.25
1.14
21.19
5.
1.
1.
59
57
75
0.25
1.99
0.10
1.82
0.06
57.50
0.46
2345°F
Alabama
Unwashed
52.64
24.64
0.88
12.41
2.62
.32
1.
2.
75
0.27
1.63
0.05
0.79
76.30
0.25
2625°F
0.52
0.03
0.55
Alabama
Crushed
43.86
26.25
1.10
15.86
4.73
1.47
2.15
0.27
3.59
0.05
0.67
66.54
0.34
2490°F
0.34
0.05
0.55
KVB 4-15900-548
65
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5.3.2 Coal Size Consistency
Coal size consistency was determined for each coal sample obtained at
Site K using the procedure described in Section 4.5. The results are listed
in Table 5-13, and graphically presented in Figures 5-16, 5-17 and 5-18.
The washed and unwashed coals were observed to be very similar in
size consistency with the unwashed coal being only slightly heavier in fines.
Both of these coals had a top size of 1-1/4 inches.
The crushed coal consisted of the washed coal run through a 3/4 inch
crusher on site. The result was an increase in fines from 20 to 44% passing
a 1/4 inch square mesh screen, and a reduction in top size. The crushed coal
lies within the ABMA recommended limits of coal sizing for overfeed stokers
as shown in Figure 5-18.
5.3.3 Effect of Coal Properties on Emissions and Efficiency
All three coals tested at Site K came from the same mine and were,
therefore, nearly identical in chemical composition. However, they differed
in ash content and in size consistency. This subsection discusses the impact
of these changes on boiler emissions and efficiency. Frequent references are
made to figures in Section 5.2, Excess Oxygen and Grate Heat Release, which
illustrate the observations.
Excess Oxygen Operating Conditions. The three coals were fired under
slightly different excess oxygen conditions. As shown in Figure 5-2, the un-
washed coal used more air than the washed coal, and the crushed coal used less
air. The differences are slight, on the order of one percent C>2, and will not
be considered as variables in this discussion.
Particulate Mass Loading. Coal properties had a major impact on
particulate mass loading at this site. As shown in Table 5-14, the high fines
crushed coal produced 58% more particulates than the washed coal at full load
and the impurity laden unwashed coal produced 180% more particulates. These
figures apply only to the uncontrolled, or boiler outlet, particulate mass
loading. After the dust collector the particulate mass loadings were quite
similar.
KVB 4-15900-548
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TABLE 5-13
AS FIRED COAL SIZE CONSISTENCY
TEST SITE K
.8
8
Test
No.
Average
PERCENT PASSING SCREEN SIZE
1" 1/2" 1/4" #8
74.5
36.8
20.4
9.3
#16
01
02
03
04
05
06
07
08
09
10
11
18
67.9
85.9
70.0
81.9
73.5
62.6
75.3
75.5
81.6
68.9
72.4
78.4
37.9
41.6
35.4
39.8
29.8
28.2
39.3
36.9
49.8
25.0
36.9
40.4
21.7
19.0
20.2
21.5
16.1
15.6
21.4
19.3
30.9
14.5
20.9
23.2
9.4
3.8
10.3
10.2
8.4
8.4
9.7
9.5
13.4
8.1
9.6
10.9
5.4
0.4
5.8
6.0
5.1
5.7
5.9
5.8
7.6
5.0
5.9
6.0
5.4
TJ
JS
8
I
12
13
14
Composite
63.4
65.4
57.1
61.0
36.9
45.6
34.2
35.5
23.1
32.0
21.7
22.7
14.9
18.9
13.2
14.0
11.1
12.5
9.0
9.8
Ave rage
61.7
38.1
24.9
15.3
10.6
15
16
17
Composite
96.7
93.7
93.2
96.3
QC n
78.6
72.2
63.3
67.6
^n A
53.7
39.4
39.4
42.4
X 1 1
25.8
20.7
20.0
21.6
»} n
13.8
13.5
12.4
13.2
T } "»
KVB 4-15900-548
67
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50
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Overfeed Stokers
Standard Deviation Limits of the
Washed Coal Size Consistency
Figure 5-16.
Size Consistency of "As Fired" Washed Coal vs
ABMA Recommended Limits of Coal Sizing for
Overfeed Stokers - Test Site K
KVB 4-15900-548
68
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95
80
50
w
H
30
R 20
u
50
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Overfeed Stokers
Standard Deviation Limits of the
Unwashed Coal Size Consistency
Figure 5-17.
Size Consistency of "As Fired" Unwashed Coal vs
Recommended Limits of Coal Sizing for Overfeed
Stokers - Test Site K
KVB 4-15900-548
69
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..,
I
en
"'
-
I
i-,
50
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Overfeed Stokers
Standard Deviation Limits of the
Crushed Coal Size Consistency
Figure 5-18. Size Consistency of "As Fired" Crushed Coal vs
ABMA Recommended Limits of Coal Sizing for
Overfeed Stokers - Test Site K.
KVB 4-15900-548
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TABLE 5-14
PARTICULATE LOADING VS COAL
Washed Coal
Crushed Coal
Unwashed Coal
Uncontrolled Particulate
lb/106Btu
Controlled Particulate
lb/106Btu
50%
Load
0.61
0.70
1.25
75%
Load
0.75
1.13
2.06
100%
Load
0.78
1.23
2.20
50%
Load
0.17
0.14
0.24
75%
Load
0.17
0.15
0.20
100%
Load
0.14
0.14
0.16
The data are graphically presented in Figures 5-3 and 5-4 of Section
5.2.
Nitric Oxide. Nitric oxide concentrations were not altered by the
coal changes other than a slight decrease while firing the crushed coal which
can be attributed to reduced excess air. The data are graphically presented
in Figure 5-7 of Section 5.2.
Carbon Monoxide. Carbon monoxide concentrations were not altered by
the coal changes. The data are graphically presented in Figure 5-9 of Section
5.2.
Sulfur Dioxide. Fuel sulfur was not a variable in these tests. How-
ever, sulfur dioxide (S02) and sulfur trioxide (S03) were measured three times
during one test on the washed coal. Two measurements were made using the Shell-
Eiteryville wet chemical method and one measurement was made using the very
similar EPA Method 6. The results are presented in Table 5-15 along with measured
sulfur concentrations in the bottom ash, flyash and coal. All measurements have
been put on a common heat input basis.
KVB 4-15900-548
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TABUE 5-15
SULFUR MEASUREMENTS
Sulfur Concentrations as lb
Sulfur in Flue Gas
Sulfur in Flyash
Sulfur in Bottom Ash
Total
Sulfur in Coal
% Undetected Sulfur
Shell (A)
1.321
.005
.019
1.345
2.111
36%
Shell (B)
1.237
.005
.019
1.261
2.111
40%
Method 6
0.919
.005
.019
0.943
2.111
55%
The sulfur balance at this site was very poor, with 1/3 to 1/2 of the
fuel sulfur going undetected. The discrepancy could just as well be in the
determination of fuel sulfur as in the determination of SOx. Nonetheless,
sulfur retention in the ash at this site represents between 1.1% and 2.5% of
the fuel sulfur, and the remaining 97.5% to 98.9% may be assumed to be emitted
as S02 and 803.
Combustibles in the Ash. Combustible concentrations in the bottom
ash, flyash and dust collector hopper ash were similar for all three coals. The
data are presented graphically in Figures 5-11, 5-12 and 5-13 of Section 5.2.
Boiler E f f iciency. Crushed coal and Washed coal produced similar
boiler efficiencies when fired under similar conditions of load and excess oxygen
Unwashed coal produced a lower efficiency than either of the others because of
its greater combustible heat loss.
The unwashed coal contained the same percentage of combustibles in
its ash as the other two coals. However, because it contained more than twice
the ash of the other two, it also had more than twice the combustible heat loss
KVB 4-15900-548
72
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Two comparisons of efficiency data obtained under similar firing
conditions but different coals are given in Table 5-16. The first set compares
Washed coal and Unwashed coal at 100% load and 8.5% 02- The second set com-
pares Washed coal and Crushed coal at 74% load and 10% 02. This data supports
the above discussion.
Boiler efficiency is graphically presented in Figures 5-14 and 5-15
of section 5.2.
Washed Coal
(Test 4)
Unwashed Coal
(Test 14)
TABLE 5-16
BOILER EFFICIENCY VS COAL
BOILER HEAT LOSSES, %
Moisture Combus-
Dry Gas Related tible Other
10.58 4.74 3.03 2.15
12.69 4.98 9.03 2.11
% BOILER
EFFICIENCY
79.53
71.19
Washed Coal
(Test 10)
Crushed Coal
(Test 15)
11.95
12.00
4.48 2.60 2.34
4.87 3.15 2.35
78.63
77.63
5.4 PARTICLE SIZE DISTRIBUTION OF FLYASH
Four particle size distribution determinations were made on the
flyash at Site K. Three of these measurements were made by Brink Cascade
Impactor and one by SASS gravimetrics under the test conditions described in
Table 5-17. Sampling procedures and test equipment descriptions are given
in Section 4.4.
KVB 4-15900-548
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TABLE 5-17
DESCRIPTION OF PARTICLE SIZE DISTRIBUTION
TESTS AT THE BOILER OUTLET
TEST SITE K
rest
No_._
3
8
16
18
Coal
Washed
Washed
Crushed
Washed
% Design
Capacity
74
100
102
78
02
%
10.9
7.3
6.0
9.8
OFA
"H20
2.2
4.9
3.8
2.5
Particle Size
Distribution Methodology
Brink Cascade Impactor
Brink Cascade Impactor
Brink Cascade Impactor
SASS Gravimetrics
The test results are presented in Table 5-18 and in Figures 5-19 and
5-20. As illustrated in Figure 5-19, the flyash from combustion of the crushed
coal contained a higher percentage of smaller particles than did the flyash
from the washed coal. The medium load test produced a higher percentage of
particles below 3 micrometers than either of the high load tests.
The SASS gravimetrics results illustrated in Figure 5-20 give a
different size distribution than the equivalent Brink test (Test No. 3). The
SASS test shows 6% below 3 micrometers vs 27% below 3 micrometers for the Brink
test. At one micrometer the two methods are in closer agreement, showing 5%,
and 7%, respectively, below one micrometer in diameter.
It is likely that differences in measurement methodology account for
some of the discrepancies in size distribution. No speculation is made at
this time as to which is more accurate. The final project report may include
such an evaluation.
KVB 4-15900-548
74
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50
20
I!
I
w
0.1
MEDIUM LOAD - WASHED
HIGH LOAD - WASHED
.313
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
Figure 5-19. Particle Size Distribution at the Boiler Outlet as
Determined by Brink Cascade Impactor - Test Site K
KVB 4-15900-548
75
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50
20
0.1
MEDIUM LOAD - WASHED
1 3
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
10
Figure 5-20.
Particle Size Distribution at the Boiler Outlet
as Determined by SASS Gravinvetries - Test Site K
KVB 4-15900-548
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TABLE 5-18
RESULTS OF PARTICLE SIZE DISTRIBUTION
TESTS AT THE BOILER OUTLET
TEST SITE K
Size Distribution
Size Concentration
Test
No.
3
8
16
18
% Below
Test Description 3 Vim
Med Load
High Load
High Load
Med Load
- Washed
- Washed
- Crushed
- Washed
27
10
12
6
% Below Ib/lO^Btu
10 ym Below 3 Um
0.216
0.064
0.148
13 0.042
lb/10bBtu
Below 10 ym
__
0.092
5.5 EFFICIENCY OF MECHANICAL DUST COLLECTOR
The collection efficiency of the mechanical dust collector was deter-
mined in each test by simultaneous particulate mass loading determinations at
the collector inlet and outlet. The data are summarized in Table 5-19 and
plotted as a function of grate heat release in Figure 5-21.
TABLE 5-19
DUST COLLECTOR EFFICIENCY VS LOAD AND COAL
Washed Coal
Crushed Coal
Unwashed Coal
50% Load
75% Load
100% Load
72.0
79.4
80.9
77.5
87.0
90.4
81.2
88.6
92.7
The dust collector efficiency was found to be sensitive to the boiler
load and to the coal fired. This had a normalizing effect on the stack emissions
As load increased, inlet concentrations increased. But due to increased
KVB 4-15900-548
77
-------
CD
CD
O
O
00
LU
(_>
QC O
UJ
Q_ O
CO
t °
UJ ?
UJ
z
o
I
(_> °
II
*~i CM
A
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS.
SHADED AREA EMPHASIZES DATA TREND.
I
T
1
I
II
T
100.0 200.0 300.0 400.0 500.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
: UfiSHEO
: UNHRSHED
: CRUSHED
FIG. 5-21
MULTICLONE EFF.
TEST SITE K
VS. GRflTE HEflT RELEflSE
SOLID SYMBOLS REPRESENT HIGH OVERFIRE AIR TESTS. SHADED AREA
EMPHASIZES DATA TREND.
4-15900-548
-------
collection efficiency, the outlet concentrations remained relatively constant
and in the case of the unwashed coal actually decreased (see Figure 5-4 of
Section 5.2.2).
This same normalizing effect was observed with the change in coals.
The higher inlet concentrations from the crushed and unwashed coals were re-
duced more than those of the washed coal.
The complete dust collector efficiency data is listed in Table 5-20.
TABLE 5-20
Test
No.
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
Coal
Type
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Unwashed
Unwashed
Unwashed
Crushed
Crushed
Crushed
Load
97
50
71
100
96
95
101
100
41
74
102
59
77
101
73
102
56
ICY OF DUST COLLECTOR
TEST SITE K
Particulate Loading
lb/106Btu Collector
Collector
Inlet
1.240
0.737
0.799
0.758
0.755
0.655
0.850
0.639
0.477
0.707
0.571
1.251
2.060
2.202
1.127
1.231
0.698
Collector Efficiency
Outlet %
0.199
0.190
0.226
0.148
0.158
0.134
0.129
0.112
0.144
0.118
0.124
Average
0.239
0.197
0.161
Average
0.147
0.140
0.144
84.0
74.2
71.7
80.5
79.1
79.5
84.8
82.5
69.8
83.3
78.3
78.9
80.9
90.4
92.7
88.0
87.0
88.6
79.4
Ave rage
85.0
KVB 4-15900-548
79
-------
5.6 SOURCE ASSESSMENT SAMPLING SYSTEM (SASS)
One SASS test was run at Test Site K. This test was conducted at 75%
of capacity on the Washed coal. SASS test results will not be reported in this
report. All SASS test results will be reported under separate cover at the
conclusion of this test program. The SASS sample catches will be analyzed
by combined gas chromatography/mass spectroscopy for total polynuclear content
In addition, seven specific polynuclear aromatic hydrocarbons (PAH) will be
sought. These are listed in Table 5-21.
TABLE 5-21
POLYNUCLEAR AROMATIC
ANALYZED IN THE SITE
Element Name
7,12 Dime thy Ibenz (a) anthracene
Dibenz (a, h) anthracene
Benzo (c) phenanthrene
3-methyl cholanthrene
Benzo (a) pyrene
Dibenzo (a,h) pyrene
Dibenzo (a,i) pyrene
Dibenzo (c,g) carbazole
HYDROCARBONS
K SASS SAMPLE
Molecular
Weight
256
278
228
268
252
302
302
267
Molecular
Formula
C2QH16
C22H14
C18H12
C21H16
C20H12
C24H14
C24H14
C20H13N
5.7 DATA TABLES
Tables 5-22 through 5-25 summarize much of the test data obtained at
Site K. These tables, in conjunction with Tables 2-1 and 2-2 of the Executive
Summary, are included for reference purposes.
KVB 4-15900-548
80
-------
TABLE 5-22
PARTICULATE EMISSIONS
TEST SITE K
t,
s
s
o
as
H
8
Test
No.
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
Coal
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Unwashed
Unwashed
Unwashed
Crushed
Crushed
Crushed
Load
97
50
71
100
96
95
101
100
41
74
102
59
77
101
73
102
56
02
8.8
13.6
10.9
8.2
7.5
8.3
7.2
7.3
13.0
10.1
6.4
12.9
11.6
8.5
10.0
6.0
10.8
PARTICIPATE EMISSIONS
lb/105Btu
1.240
0.737
0.799
0.758
0.755
0.655
0.850
0.639
0.477
0.707
0.571
1.251
2.060
2.202
1.127
1.231
0.698
gr/SCF
0.517
0.185
0.277
0.332
0.355
0.283
0.396
0.299
0.130
0.267
0.288
0.340
0.644
0.939
0.415
0.628
0.237
Ib/hr
79.6
24.2
38.5
49.1
46.7
40.8
54.2
43.8
14.1
35.2
39.7
48.5
107.0
143.9
68.3
77.7
19.7
J 1
Velocity
ft/sec
26.45
20.23
21.33
24.88
25.23
27.04
27.02
25.55
17.48
24.70
25.83
26.60
27.79
31.39
24.90
25.95
20.55
e
1 §
1 §
1 0
1 r
1 ^
1 ^
1 %
1
1
L
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
^^^^^MM
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Washed
Unwashed
Unwashed
Unwashed
Crushed
Crushed
Crushed
97
50
71
100
96
95
101
100
41
74
102
59
77
101
73
102
56
8.7
13.8
11.0
8.1
8.8
9.3
8.1
7.8
13.2
10.2
7.4
13.6
11.6
8.7
10.1
6.4
11.3
0.199
0.190
0.226
0.148
0.158
0.134
0.129
0.112
0.144
0.118
0.124
0.239
0.197
0.161
0.147
0.140
0.144
0.084
0.047
0.078
0.066
0.067
0.053
0.056
0.050
0.038
0.044
0.059
0.059
0.062
0.068
0.054
0.070
0.046
12.8
6.2
10.9
9.6
9.8
8.3
8.2
7.7
4.3
5.9
8.6
9.3
10.2
10.5
8.9
8.8
4.1
52.48
39.59
41.82
51.03
48.79
51.77
52.80
51.34
32.89
48.78
49.56
50.11
53.70
54.46
44.95
47.05
36.59
81
KVB 4-15900-548
-------
TABLE 5-23
HEAT LOSSES AND EFFICIENCIES
TEST SITE K
Q
X
ft
ff
1
-
jft
r-t*
M
i_3
r-t
j
a
CQ
|j
2
**<
3
o
H
CO
K
01
02
03
04
05
06
07
08
09
10
11
18
CO
§
rtj
3
S
Q
11.01
16.37
12.09
10.58
9.82
11.41
10.23
10.55
12.07
11.95
9.59
12.12
^
g
fa
2
H
EH
CO
H
0.49
0.63
0.58
0.67
0.54
0.64
0.71
0.69
0.54
0.48
0.58
0.62
1 «N
a x
°S
|*
p; o
faH
&B
x m
4.10
4.14
4.02
4.07
4.04
4.23
4.17
4.15
4.04
4.00
4.05
4.10
CO
a
ffl X
S3
B>H
1-1
a ^
02
O H
0.57
0.39
0.37
0.40
0.44
0.28
0.33
0.27
0.16
0.34
0.25
0.32
X
CO CO
r i ^f*
9 *
« s
H O
CO EH
O O
a «
85
1.83
1.14
2.13
2.63
6.72
5.48
2.49
2.02
15.70
2.26
2.80
1.49
S
PQ
H
EH
B
|_J
§ w
8S
fa
g§
EH
gg
2.40
1.53
2.50
3.03
7.16
5.76
2.82
2.29
15.86
2.60
3.05
1.81
fyt
PS
*9
O H
H O
H PQ
§3
Q O
< «
K fo
0.64
1.22
0.86
0.65
0.65
0.65
0.62
0.62
1.50
0.84
0.61
0.79
Q
5
CO
<
1
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
CO
M
CO
CO
3
K!
<
8
EH
20.14
25.39
21.55
20.47
23.71
24.19
20.05
19.80
35.51
21.37
19.38
20.94
>H
W
M
u
H
fa
fa
H
a:
**<
a
H
§
79.86
74.61
78.45
79.53
76.29
75.81
79.95
80.20
64.49
78.63
80.62
79.06
Q
W
CO
12
13
14
15.42
15.38
12.69
0.57
0.64
0.62
4.01
4.09
4.36
0.54
1.04
1.10
3.06
4.08
7.93
3.60
5.12
9.03
1.04
0.80
0.61
1.50
1.50
1.50
26.14
27.53
28.81
73.86
72.47
71.19
Q
§
\s
CO
Si
u
15
16
17
12.00
9.60
10.87
0.74
0.64
0.67
4.13
4.21
4.13
0.53
0.66
0.31
2.62
0.92
13.74
3.15
1.58
14.05
0.85
0.61
1.10
1.50
1.50
1.50
22.37
18.14
32.32
77.63
81.86
67.68
KVB 4-15900-548
82
-------
TABLE 5-24
PEPCENT COMBUSTIBLES IN REFUSE
TEST SITE K
Test
-0
01
S
Lliant,
i i
H
«
Rj
1
"9
No.
01
02
03
04
05
06
07
08
09
10
11
18
Boiler
Outlet
32.2
36.0
36.7
40.8
29.4
27.0
29.4
24.0
34.2
30.9
Dust Collector
Hopper
AVG
32.1
29.52
Bottom
Ash
44.29
12
13
14
AVG
32.1
29.75
32.19
o
J!
3
B
15
16
17
AVG
34.1
26.49
26.46
26.48
44.52
KVB 4-15900-548
83
-------
TABLE 5-25
STEAM FLOWS AND HEAT RELEASE RATES
TEST SITE K
CD
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Capacity
%
97
50
74
100
96
95
101
100
41
74
102
59
77
101
73
102
56
78
Steam Flow
Ib/hr
48,708
24,968
35,593
49,750
47,750
47,454
50,250
50,000
20,250
36,782
51,102
29,357
38,250
50,602
36,316
50,800
27,750
39,000
Heat Input*
106Btu/hr
64.2
32.1
48.1
64.7
61.8
60.5
63.8
68.5
29.6
49.8
69.6
38.8
51.9
65.3
48.1
63.1
36.8
53.2
Heat Output**
106Btu/hr
58.0
29.7
42.3
59.2
56.8
56.5
59.8
59.5
24.1
43.7
60.8
34.9
45.5
60.2
43.2
60.5
33.0
46.4
Front Foot
Heat Release
106BtuAr-ft
6.42
3.21
4.81
6.47
6.18
6.05
6.38
6.85
2.96
4.98
6.96
3.88
5.19
6.54
4.81
6.31
3.68
5.32
Grate Heat
Release
103Btu/hr-ft2
401
201
301
405
386
380
399
428
185
311
435
242
325
408
301
394
230
333
Furnace Heat
Release
103Btu/hr-ft3
24.6
12.3
18.4
24.8
23.7
23.1
24.4
26.2
11.3
19.1
26.6
14.8
19.9
25.0
18.4
24.1
14.1
20.4
* Heat Input Data Based on Coal Flow Rate and Heating Value
** Heat Output Data Based on Steam Flow Rate and Enthalpy of steam and feedwater
KVB 4-15900-548
-------
APPENDICES
Page
APPENDIX A English and Metric Units to SI Units . . 86
APPENDIX B SI Units to English and Metric Units . . 87
APPENDIX C SI Prefixes 88
APPENDIX D Emissions Units Conversion Factors ... 89
85
-------
APPENDIX A
CONVERSION FACTORS
ENGLISH AND METRIC UNITS TO SI UNITS
To Convert From
in
in2
ft
ft2
ft3
To
cm
m
m-
Multiply By
2.540
6.452
0.3048
0.09290
0.02832
Ib
Ib/hr
lb/106BTU
g/Mcal
BTU
BTU/lb
BTU Air
J/sec
JAir
BTU/ft/hr
BTU/ftAir
BTU/ft2Air
BTU/ft2/hr
BTU/ft3/hr
BTU/ft3Air
psia
"H2O
Rankine
Fahrenheit
Celsius
Rankine
FOR TYPICAL COAL FUEL
ppm @ 3% 02 (S02)
ppm @ 3% 02 (S03)
ppm @ 3% 02 (NO)*
ppm @ 3% 02 (N02)
Kg
Mg/s
ng/J
ng/J
J
JAg
w
w
w
W/m
J/hr/m
W/m2
J/hr/m2
W/m3
J/hr/m3
Pa
Pa
Celsius
Celsius
Kelvin
Kelvin
ng/J (lb/106Btu)
ng/J (Ib/lO^Btu)
(lb/106Btu)
(lb/106Btu)
(lb/106Btu)
ng/J
ng/J
ng/J
ng/J
0.4536
0.1260
430
239
1054
2324
0.2929
1.000
3600
0.9609
3459
3.152
11349
10.34
37234
6895
249.1
C
C
K
K
5/9R-273
5/9(F-32)
C+273
5/9 R
0.851
1.063
0.399
0.611
0.372
0.213
(1.98xlO~3)
(2.47xlO~3)
(9.28xlO~4)
(1.42xlO~3)
(8.65xlO~4)
(4.95xlO~4)
ppm @ 3% O2 (CO)
ppm @ 3% 02 (CH4) ng/J (lh/10DBtu)
q/kg of fuel**
*Federal environmental regulations express NOx in terms of NO2;
thus NO units should be converted using the NO2 conversion factor.
**Based on higher heating value of 10,000 Btu/lb. For a heating value
other than 10,000 Btu/lb, multiply the conversion factor by
10,OOO/(Btu/lb).
KVB 4-15900-548
86
-------
APPENDIX B
CONVERSION FACTORS
SI UNITS TO ENGLISH AND METRIC UNITS
To Convert From
cm
cm
m
m2
Kg
Mg/s
ng/J
ng/J
J
JAg
J/hr/m
J/hr/m2
J/hr/m3
W
W
W/m
W/m2
W/m3
Pa
Pa
Kelvin
Celsius
Fahrenheit
Kelvin
FOR TYPICAL COAL FUEL
To
in
in2
ft
ft2
ft3
Ib
Ib/hr
Ib/lO^BTU
g/Mcal
BTU
BTU/lb
BTU/ft/hr
BTU/ft2/hr
BTU/ft3/hr
BTU/hr
JAr
BTU/ft/hr
BTU/ft2/hr
BTU/ft3/hr
psia
"H20
Fahrenheit
Fahrenheit
Rankine
Rankine
Multiply By
0.3937
0.1550
3.281
10.764
35.315
2.205
7.937
0.00233
0.00418
0.000948
0.000430
0.000289
0.0000881
0.0000269
3.414
0.000278
1.041
0.317
0.0967
0.000145
0.004014
F - 1.8K-460
F = 1.8C+32
R = F+460
R = 1.8K
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
ppm
ppm
ppm
ppm
ppm
ppm
g/kg
@ 3% O2 (SO2)
e 3% o2 (so3)
@ 3% O2 (NO)
@ 3% 02 (N02)
@ 3% 03 (CO)
@ 3% 02 (CH4)
of fuel
1.18
0.941
2.51
1.64
2.69
4.69
0.000233
KVB 4-15900-548
87
-------
APPENDIX C
SI PREFIXES
Multiplication
Factor Prefix SI Symbol.
. _ i a
exa E
, _ Peta P
1012 tera T
lo| giga G
10 mega M
10| kilo k
10 hecto* h
10* deka* da
10 deci* d
10~2 centi* c
10~3 milli m
10" micro y
10~^ nano n
10~12 pico p
10~15 femto f
10~18 atto a
*Not recommended but occasionally used
KVB 4-159OO-548
88
-------
APPENDIX D
EMISSION UNITS CONVERSION FACTORS
FOR TYPICAL COAL FUEL (HV = 13,320 BTU/LB)
Multiply
TO ~\ By
Obtain
» Weight in Fuel
S N
lbs/106Btu
SO2 N02
grams/106Cal
S02 N02
PPM
(Dry 8 3* 02)
SOx NOx
Grains/SCF.
(Dry ? H\ CO2)
SO2 NO2
% Weight
In Fuel
0.666
z
0.370
0.405
3.2x10
-4
0.225
Z
1.48
5.76x10"
z
.903
Ibs/lO^Btu
SO,
1.50
NO,
(.556)
9.8x10
,-4
(2.23)
z
2.47
(.556)
14.2x10"
(2.23)
SO,
2.70
grams/106Cal
(1.8)
MO,
4.44
5.6x10'
,-4
(4.01)
(1.8)
25.6x10'
Z
(4.01)
SOx
758
PPM
SOS
281
(Dry e 3% 02)
NOx
z
1736
704
1127
391
1566
S02
Grains/SCF
(Dry* 12% CO2)
N02
.676
(.448)
(.249)
8.87x10
,-4
1.11
(.448)
(.249)
6.39x10"
NOIE: 1. Values in parenthesis can be used for all flue gas constituents such as oxides of
oxides of nitrogen, oxides of sulfur, hydrocarbons, particulates, etc.
2. Standard reference temperature of 530«R was used.
carbon <
KVB 4-15900-548
89
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-80-138a
2.
3. RECIPIENT'S ACCESSION NO.
Field Tests of industrial Stoker Coal-
fired Boilers for Emissions Control and Efficiency
ImprovementSite K
5. REPORT DATE
May 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
P. L.Langsjoen, J.O.Burlingame, and
J.E. Gabriels on
>. PERFORMING ORGANIZATION NAME AND ADDRESS
KVB, Inc.
6176 Olson Memorial Highway
Minneapolis, Minnesota 55422
10. PROGRAM ELEMENT NO.
EHE624
11. CONTRACT/GRANT NO.
EPA-IAG-D7-E681 and
DoE-EF-77-C-01-2609
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development*
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 9-11/79
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES IERL-RTP project officer is R.Hall.(*)Cosponsors are DoE (W.
Harvey Jr.) and the American Boiler Manufacturers Assn. EPA-600/7-78-136a,
-79-041a,-130a,-147a,-80-064a,-065a,-082a.-I12a,136a, and -137a cover sites A-J.
16. ABSTRACT.^ report gjves results of field measurements made on a 50,000lb steam/
hr coal-fired overfeed stoker with traveling grate. The effects of various parameters
on boiler emissions and efficiency were studied. Parameters include overfire air,
excess oxygen, grate heat release, and coal properties. Measurements include O2,
CO2, CO, NO, SO2, SOS, incontrolled particulate loading, particle size distribu-
tion of the uncontrolled flyash, and combustible content of the ash. In addition to
test results and observations, the report describes the facility tested, coals fired,
test equipment, and procedures. On the primary coal, full-load uncontrolled par-
ticulate loading on this unit averaged 0. 78 Ib/million Btu, while full-load con-
trolled particulate loading averaged 0.14 Ib/million Btu. Full-load NO emissions
averaged 0.31 Ib/million Btu.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Air Pollution
Boilers
ombustion
oal
Field Tests
Dust
Stokers
Improvement
Efficiency
Flue Gases
Fly Ash
Particle Size
Nitrogen Oxides
Sulfur Oxides
Air Pollution Control
Stationary Sources
Combustion Modification
Spreader Stokers
Traveling Grate Stokers
Particulate
Overfire Air
13 B
13A
21B
21D
14B
11G
14G
07B
3. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
96
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
90
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