ABMA
DoE
EPA
American
Boiler Manufacturers
Association
1 500 Wilson Boulevard
Arlington VA 22209
United States
Department
of Energy
Division of Power Systems
Energy Technology Branch
Washington DC 20545
U.S. Environmental Protection Agency
Office of Research and Development
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600 7-79-130a
May 1979
Field Tests of Industrial
Stoker Coal-fired Boilers
for Emissions Control
and Efficiency
Improvement - Site C
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-600/7-79-130a
May 1979
Field Tests of Industrial Stoker
Coal-fired Boilers for Emissions
Control and Efficiency Improvement -
Site C
by
J.E. Gabrielson, P.L. Langsjoen, and T.C. Kosvic
KVB, Inc.
6176 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: Robert E. Hall (EPA) and William T. Harvey, Jr. (DoE)
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
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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ACKNOWLEDGEMENTS
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 (DCE) 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'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 participating committee members listed alphabetically are as follows:
R. D. Bessette Island Creek Coal Company
T. Davis Combustion Engineering
J. Dragos Consolidation Coal
T. G. Healey Peabody Coal
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. Poitrass 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 spend much time in the field, often under adverse conditions, testing the
boilers and gathering data for this program. Those involved at Site C were
Jim Burlingame, Russ Parker, Jon Cook, Mike Jackson, and Jim Demont.
Finally, our gratitude goes to the host boiler facilities which
invited 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.
ii
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TABLE OF CONTENTS
Section Page
ACKNOWLEDGEMENTS ii
LIST OF FIGURES v
LIST OF TABLES vii
1.0 INTRODUCTION 1
2.0 EXECUTIVE SUMMARY 3
3.0 DESCRIPTION OF FACILITY TESTED AND COALS FIRED 11
3.1 Boiler C Description 11
3.2 Overfire Air System 11
3.3 Flyash Reinjection System 15
3.4 Test Port Locations 16
3.5 Coals Utilized 18
4.0 TEST EQUIPMENT AND PROCEDURES 21
4.1 Gaseous Emissions Measurements 21
4.1.1 Analytical Instruments and Related Equipment . 21
4.1.2 Recording Instruments 26
4.1.3 Gas Sampling and Conditioning System 26
4.2 Gaseous Emission Sampling Techniques 26
4.3 Sulfur Oxides (SOx) Measurement and Procedures .... 28
4.4 Particulates Measurement and Procedures 30
4.5 Particle Size Distribution Measurement and Procedure . 32
4.6 Coal Sampling and Analysis Procedure 35
4.7 Ash Collection and Analysis for Combustibles 36
4.8 Boiler Efficiency Evaluation 37
4.9 Modified Smoke Spot Number 38
4.10 Trace Species Measurement 39
4.11 Flyash Reinjection Evaluation 39
5.0 TEST RESULTS AND OBSERVATIONS 43
5.1 Overfire Air 43
5.1.1 Overfire Air Flow Rate Determination 43
5.1.2 Particulate Loading vs Overfire Air 50
5.1.3 Nitric Oxide vs Overfire Air 51
5.1.4 Carbon Monoxide vs Overfire Air 56
5.1.5 Boiler Efficiency vs Overfire Air 56
5.2 Flyash Reinjection 61
5.3 Excess Oxygen and Grate Heat Release 71
5.3.1 Excess Oxygen Operating Levels 71
5.3.2 Particulate Loading vs Excess Oxygen and Grate
Heat Release 73
5.3.3 Nitric Oxide vs Excess Oxygen and Grate Heat
Release 77
KVB 15900-528
ill
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TABLE OF CONTENTS
Continued
Section
5.3.4 Carbon Monoxide vs Excess Oxygen and Grate
Heat Release 77
5.3.5 Combustibles in the Ash vs Excess Oxygen and
Grate Heat Release 84
5.3.6 Boiler Efficiency vs Excess Oxygen and Grate
Heat Release 90
5.4 Coal Properties 92
5.4.1 Coal Size Consistency 97
5.4.2 Sulfur Balance . . . 97
5.5 Particle Size Distribution of Flyash 102
5.6 Efficiency of Multiclone Dust Collector 108
5.7 Modified Smoke Spot Number Ill
5.8 Source Assessment Sampling System Ill
5.9 Data Tables 115
APPENDIX A - Excess Air Investigation 122
APPENDIX B - English and Metric Units to SI Units .... 126
APPENDIX C - SI Units to English and Metric Units .... 127
APPENDIX D - SI Prefixes 128
APPENDIX E - Emission Units Conversion Factors for
Typical Coal Fuel 129
A Supplement to this report containing all of the unreduced data
obtained at Site C is available from NTIS or through EPA. The
Supplement has the same EPA report number as this report but is
followed by the letter "b" rather than "a". It also has the same
title but is followed by the words, "Data Supplement." The Data
Supplement contains no discussion, it is a compilation of hand
written data sheets made available to researchers who wish to ex-
amine the data in greater depth than that covered in this report.
KVB 15900-528
IV
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LIST OF FIGURES
Figure Page
3-1 Sectional Side Elevation and Plan View 12
3-2 Boiler C Sample Plane Geometry 17
4-1 Flow Schematic of Mobile Flue Gas Monitoring Laboratory . . 27
4-2 SOx Sample Probe Construction 29
4-3 Sulfur Oxides Sampling Train 29
4-4 Particulate Sampling Train 31
4-5 Brink Cascade Impactor Sampling Train Schematic 33
4-6 Field Service Type Smoke Tester 38
4-7 Source Assessment Sampling System (SASS) Flow Diagram ... 40
5-1 Overfire Air and Reinjection Air Flow Schematic 45
5-2 Pressure-Flow Relationship, OFA System 47
5-3 Pressure-Flow Relationship, OFA System 48
5-4 Contribution of Overfire Air and Reinjection Air to Total
Combustion Air 49
5-5 Particulate Loading Broken Down into Combustible and In-
organic Fractions for Three Overfire Air Test Sets on
Eastern Low Fusion Coal 53
5-6 Particul^ee Loading Broken Down into Combustible and In-
organic Fractions for Three Overfire Air Test Sets on
Western Coal 55
5-7 Nitric Oxide Emissions vs Overfire Air 58
5-8 Carbon Monoxide Emissions vs Overfire Air 60
5-9 Flyash Flow Rates with Different Reinjection Configurations
Eastern Low Fusion Coal 63
5-10 Flyash Flow Rates with Different Reinjection Configurations
Western Coal 65
5-11 Particle Size Concentrations for Boiler Outlet Particulates
under Full and Reduced Flyash Reinjection Conditions -
Eastern Low Fusion Coal 67
5-12 Particle Size Concentrations for Boiler Outlet Particulates
under Full and Reduced Flyash Reinjection Conditions -
Western Coal 68
5-13 Particulate Concentration Reduction as a Function of Particle
Diameter for the Change in Flyash Reinjection Configuration
from Full to No Reinjection 69
5-14 Oxygen vs Grate Heat Release 72
5-15 Oxygen vs Grate Heat Release 74
5-16 Boiler Out Part, vs Grate Heat Release 75
5-17 Multiclone Out Part, vs Grate Heat Release 76
5-18 Nitric Oxide vs Grate Heat Release 78
5-19 Nitric Oxide vs Oxygen 79
5-20 Nitric Oxide vs Oxygen 80
5-21 Nitric Oxide vs Oxygen 81
5-22 Nitric Oxide vs Oxygen 82
5-23 Nitric Oxide Trends vs ©2 and Boiler Loading at Test Site C 83
5-24 Carbon Monoxide vs Grate Heat Release 85
5-25 Carbon Monoxide vs Oxygen - Eastern Low Fusion Coal 86
KVB 15900-528
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LIST OF FIGURES
(Continued)
Figure Page
5-26 Carbon Monoxide vs Oxygen - Western Coal 87
5-27 Boiler Out Comb, vs Grate Heat Release 88
5-28 Bottom Ash Comb, vs Grate Heat Release 89
5-29 Boiler Efficiency vs Grate Heat Release 91
5-30 Size Consistency of "As Fired" Eastern Low Fusion Coal vs
ABMA Recommended Limits of Coal Sizing for Spreader Stokers 98
5-31 Size Consistency of "As Fired" Western Coal vs ABMA Recom-
mended Limits of Coal Sizing for Spreader Stokers .... 99
5-32 Size Consistency of "As Fired" Eastern High Fusion Coal vs
ABMA Recommended Limits of Coal Sizing for Spreader Stokers 100
5-33 Bahco Classifier and Sieve Analysis Particle Size Distri-
bution 104
5-34 Particle Size Distribution from SASS Gravimetrics 105
5-35 Particle Size Distribution from Brink Cascade Impactor . . . 107
5-36 Multiclone Efficiency vs Grate Heat Release 110
5-37 Smoke Spot Number vs Particulate Loading 113
5-38 Smoke Spot Number vs Combustible Loading 114
KVB 15900-528
vi
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LIST OF TABLES
Table Page
2-1 Emission Data Summary 8
3-1 Design Data 13
3-2 Predicted Performance 14
3-3 Average Coal Analysis 19
5-1 Overfire Air and Reinjection Air Flow Rates 46
5-2 Effect of Overfire Air on Emissions & Efficiency - Eastern
Low Fusion Coal 52
5-3 Effect of Overfire Air on Emissions & Efficiency - Western
Coal 54
5-4 Nitric Oxide Emissions vs Overfire Air 57
5-5 Carbon Monoxide Emissions vs Overfire Air 59
5-6 Effect of Flyash Reinjection on Emissions and Efficiency
Burning Eastern Low Fusion Coal 62
5-7 Effect of Flyash Reinjection on Emissions and Efficiency
Burning Western Coal 64
5-8 Fuel Analysis - Eastern Low Fusion Coal 93
5-9 Fuel Analysis - Western Coal 94
5-10 Fuel Analysis - Eastern High Fusion Coal 95
5-11 Mineral Analysis of Coal Ash 96
5-12 Sulfur Balance 101
5-13 Particle Size Distribution Tests and Methodology Used . . . 103
5-14 Size Distribution and Concentration of Flyash at Boiler
Outlet as a Function of Reinjection Configuration .... 106
5-15 Efficiency of Multiclone Dust Collector 109
5-16 Modified Smoke Spot Data 112
5-17 Polynuclear Aromatic Hydrocarbons Analyzed in Site C
SASS Samples 115
5-18 Particulate Emissions 116
5-19 Heat Losses and Efficiencies 117
5-20 Percent Combustibles in Refuse 118
5-21 As Fired Coal Size Consistency 119
5-22 Steam Flows & Heat Release Rates 120
KVB 15900-528
VI1
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SECTION 1.0
INTRODUCTION
In recent years the vast majority of industrial boiler installations
have been packaged or shop assembled gas and oil fired boiler units which could
be purchased and installed at substantially lower costs than conventional coal
burning boiler-stoker equipment. Because of the decline in the industrial coal
market, little or no work has been done in recent years to improve specification
data and information made available to consulting engineers and purchasers of
coal burning boiler-stoker equipment. The current implementation of more rigid
air pollution regulations has made it difficult for many coal burning instal-
lations to comply with required stack emission limits, and this has become a
further negative influence on coal burning installations.
A field test program to address this problem has been awarded to the
American Boiler Marjfacturers Association (ABMA), (which, in turn, has sub-
contracted the field test portion to KVB, Inc., of Minneapolis, Minnesota).
The program is sponsored by the 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.
The objective of the test program is to produce information which will
increase manufacturers' ability to design and fabricate stoker boilers which
are an economical and environmentally satisfactory alternative to importation
and combustion of expensive oil. In order to do this, it is necessary to define
stoker boiler designs which will provide efficient operation with minimum gaseous
and particulate emissions, and define what those emissions are in order to
facilitate preparation of attainable national emission standards for industrial
size, coal-fired units.
Further objectives are to: provide assistance to stoker boiler
operators in planning for 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.
KVB 15900-528
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In order to meet these objectives, it is necessary to determine
emissions and efficiency as functions of changes in coal analysis and sizing,
degree of flyash reinjection, overfire air admission, ash handling, grate size,
etc., for various boiler, furnace and stoker designs.
This report is the Final Technical report for the third of eleven
boilers to be tested under the program described above. It contains a des-
cription of the facility tested, the coals fired, the test equipment and
procedures, and the results and observations of testing. A data supplement
to this report contains the "raw" data sheets from the 50 tests conducted. The
data supplement has the same EPA report number as this report except that it is
followed by "b" rather than "a". As a compilation of all data obtained at this
test site, it 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. This final
report will provide the technical basis for the ABMA publication on "Design
and Operating Guidelines for Industrial Stoker Firing," and will be available
to interested parties through the EPA and NTIS. A separate report covering
trace species data will also be written at the completion of this program. It,
too, will be available to interested parties through the EPA and through NTIS.
Data in this report is presented in English units. It is EPA policy
to use System International (S.I.) units in all reports. However, it was
determined that English units were necessary in this case. 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 third
site tested, this is the Final Technical Report for Test Site C under the
program entitled, "A Testing Program to Update Equipment Specifications and
Design Criteria for Stoker Fired Boilers."
KVB 15900-528
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SECTION 2.0
EXECUTIVE SUMMARY
A coal fired spreader stoker rated at 182,500 Ib/hr steam was
extensively tested for emissions and efficiency between April 13 and July 5,
1978. This Section summarizes the test results in a bullet format with references
to supportive figures, tables and commentary found in the main text of this
report.
UNIT TESTED - Described in Section 3.0, pages 11-17
Babcock & Wilcox Boiler
Built 1975
Single pass - two drum Stirling
182,500 Ib/hr rated capacity
875 psig operating steam pressure
900°F superheated steam temperature
Economizer
Air Heater
^ Detroit Rotograte Stoker
Spreader
Traveling grate - front discharge
Reinjection from multiclone D.C. and boiler hopper
Two rows OFA on front wall and two rows on rear wall
COALS TESTED - Individual coal analysis given in Tables 5-8, 5-9, 5-10 and
5-11, pages 93-96. Commentary in Section 3.0, pages 18-19.
Eastern Low Fusion Coal (referred to as E-Coal)
12,260 BTU/lb
11.2% Ash
2.9% Sulfur
5.3% Moisture
1,985°F Initial Ash Deformation
Western Coal (referred to as W-Coal)
8,490 BTU/lb
9.0% Ash
0.7% Sulfur
26% Moisture
2,185°F Initial Ash Deformation
KVB 15900-528
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Eastern High Fusion Coal (referred to as H-Coal)
11,850 BTU/lb
9.2% Ash
0.9% Sulfur
9.1% Moisture
2,145°F Initial Ash Deformation
OVERFIRE AIR TEST RESULTS - Described in Section 5.1, pages 43-60. Overfire
air pressure was varied between 5" and 25" H2O.
These changes were made collectively, i.e., all
four rows of air jets together, and selectively,
i.e., bias pressures to the upper, lower, front
and rear rows of air jets individually.
Particulate Loading - High balanced overfire air produced the lowest
particulate loadings, but the relationship between OFA and partic-
ulates is not statistically significant. (Sections 5.1.2, pages
50-51; Tables 5-2, 5-3, pages 52, 54; Figures 5-5, 5-6, pages 53, 55)
Nitric Oxide - NO concentrations increased an average 9% when over-
fire air pressure was increased from 5" to 25" H20. The lower rear
air jets were most responsible for this increase. (Section 5.1.3,
pages 51, 56; Table 5-4, page 57)
Carbon Monoxide - CO concentrations were reduced an average 30% when
overfire air was increased from 5" to 25" H2O. The lower rear air
jets were most responsible for this reduction. (Section 5.1.4,
page 56; Table 5-5, page 59)
Overfire Air Flow Rate - OFA flow rates were measured for each row of
jets at three static pressures. At maximum boiler capacity, OFA
can account for as much as 33% of the total air introduced into the
furnace. (Section 5.1.1, pages 43-50; Table 5-1, page 46; Figures
5-1, 5-2, 5-3, 5-4, pages 45, 47-49)
Boiler Efficiency - Changes in boiler efficiency could not be related
to OFA conditions. (Section 5.1.5, page 56; Tables 5-2, and 5-3,
pages 52, 541
FLYASH REINJECTION TEST RESULTS - Described in Section 5.2, pages 61-71. In a
test series repeated on both E-Coal and W-Coal,
flyash reinjection was stopped from the multi-
clone dust collector, and then from both the
multiclone dust collector and the boiler hopper.
Particulate Loading - Particulate loading was drastically reduced when
reinjection was stopped. Seventy-five percent reductions in loading
(.lb/106BTU) were measured at the boiler outlet and 45% reductions
were measured at the multiclone outlet (see Table on page 61; also
Tables 5-6, 5-7, pages 62, 64; Figures 5-9, 5-10, pages 63, 65)
KVB 15900-528
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* Particle Size Distribution - Bahco Classifier and sieve tests show
that particulate mass at the boiler outlet was reduced 80% in the
size range 20-300 micrometers and 55% in the size range 0-20 micro-
meters. These reductions occurred when reinjection was stopped
completely. (Figures 5-11, 5-12, 5-13, pages 67-69; commentary
page 66)
* Combustion Efficiency - Stopping flyash reinjection did not reduce
combustion efficiency if the assumption that 70% of the collected
ash was reinjected is true. Because this figure is based on design
specifications and not actual measurement, no definitive conclusion
is made. (Commentary page 70)
* Multiclone Collection Efficiency - It decreased four percent when
flyash reinjection was stopped. This decrease was due to a shift in
particle size distribution toward finer particles. (Figure 5-36,
page 110; commentary on page 108)
BOILER EMISSION PROFILES - Described in Section 5.3, pages 71-92. Boiler
emissions were measured over the load range 55-
100% of design capacity which corresponds to a
grate heat release range of 250,000 to 500,000
BTU/hr-ft2. Measured excess oxygen levels ranged
from 7.2% to 12.5%
* Excess Oxygen Operating Levels - O2 and load conditions (load expressed
as grate heat release) under which all tests were run are shown in
Figure 5-14, page 72. Particulate test conditions are profiled in
Figure 5-15, page 74. The lower limit of 7% O2 was thought to be
high. This was the result of a coal segregation problem (report in
appendix, page 122).
* Particulate Loading - Boiler outlet particulate loading profile in
Figure 5-16, page 75. Multiclone outlet particulate loading profile
in Figure 5-17, page 76. Particulate loading increased with grate
heat release more than doubling between 300 and SOOxlO3 BTU/hr-ft2.
At design capacity, boiler outlet loadings ranged from 28 to 36 lb/106
BTU. At the multiclone outlet the range was 0.74 to 1.07 lb/106BTU.
Nitric Oxide - NO data is profiled in Figures 5-18 and 5-19, pages
78-79. NO trend lines are depicted in Figures 5-20, 5-21, 5-22, and
5-23, pages 80-83. NO increased by an average of 30 ppm for each
one percent O2 increase, at constant load. At design capacity, NO
ranged from 250 to 400 ppm.
Carbon Monoxide - CO data is profiled in Figures 5-24, 5-25 and 5-26,
pages 85-87. CO increased with O2 over the range tested. CO also
increased with increasing grate heat release.
KVB 15900-528
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BOILER EFFICIENCY - The boiler efficiency profile is shown in Figure 5-29,
page 91. Boiler efficiency was invariant with load,
being in the range of 77.5 to 83%.
DUST COLLECTOR EFFICIENCY - Multiclone dust collector efficiency was invariant
with load. It averaged 96.7%. (Figure 5-36, page
110; commentary page 108, Section 5.6)
COAL PROPERTIES - Described in Section 5.4, pages 92-101. Three coal types
were tested.
Particulate loading was not affected, however, coal size consistency
and coal ash did not vary greatly between coals. (Figures 5-16,
5-17, pages 75-76)
Nitric oxide concentration was not affected (Figure 5-18, page 78)
Carbon monoxide emissions were highest when burning Western coal
where they ranged from 200-700 ppm. On the Eastern coals, CO
levels remained below 200 ppm (Figures 5-25 and 5-26, pages 86-87)
Combustibles in ash were affected as follows, (Figures 5-27, 5-28,
pages 88, 89; Table 5-20, page 118):
Boiler Out Comb. Bottom Ash Comb.
E Coal 40% 8%
W Coal 11% 18%
H Coal 17% 1%
^ Combustion efficiency was lowest for Western coal because of its
high moisture content (Figure 5-29, page 91; Table, page 92)
Coal size consistency was not a variable. Fines averaged 46% passing
1/4" for all three coals (Figures 5-30, 5-31, 5-32, pages 98-100;
commentary page 97)
Sulfur retention in the ash ranged from 6% to 18%. There is insufficient
data to correlate sulfur retention with ash properties. (Table 5-12,
page 101, commentary page 97)
Particle size distribution did not vary signficantly with coal type
(Section 5.5, pages 102-107; Figures 5-32, 5-33, 5-35, pages 104,
105, 107)
KVB 15900-528
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SMOKE SPOT NUMBER - Described in Section 5.7, page 111. Measurements were
taken at the multiclone outlet using 1, 2 and 3 pumps on
a Bacharach smoke spot tester.
Smoke spot numbers did not correlate with either particulate loading
or combustible loading at the multiclone outlet. (Figures 5-37,
5-38, pages 113-114).
SOURCE ASSESSMENT SAMPLING SYSTEM - Described in Section 5.8 pages 111-115.
Flue gas was sampled at the boiler outlet
for polynuclear aromatic hydrocarbons and
trace elements. Data will be presented in
a separate report upon completion of this
test program.
The emissions data is summarized in Table 2-1 on the following page.
Other data tables are included at the end of Section 5.0, Test Results and
Observations. For reference, a Data Supplement containing all of the un-reduced
data obtained at Site C is available under separate cover but with the same
title followed by the words "Data Supplement," and having the same EPA document
number followed by the letter "b" rather than "a". Copies of this report and
the Data Supplement are available through EPA and NTIS.
KVB 15900-528
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TABLE 2-1
EMISSION DATA SUMMARY
TEST SITE C
Test
No
1
2
3
4
5A
SB
5C
6A
68
6C
7A
7B
7C
70
8
9
10
11
12
13
14
15
16
17A
17B
17C
ISA
1SB
ISC
19
20
21A
2 IB
21C
22A
22B
22C
23
24
25
26
27
28
29
30A
. Date
4/13/78
4/19/78
4/20/78
4/20/78
4/21/78
4/25/78
5/01/78
5/03/78
5/03/78
5/04/78
5/04/78
5/09/78
5/10/78
5/11/78
5/12/78
5/12/78
5/12/78
5/13/78
5/16/78
5/16/78
5/17/78
5/18/78
S/19/78
S/23/78
5/24/78
5/25/78
5/26/78
5/29/78
Load
%
99
97
92
93
69
89
93
93
93
91
93
91
93
76
76
92
55
77
77
100
98
78
99
100
99
100
59
Coal*
E
E
Z
E
E
E
E
E
E
E
E
E
E
E
B
E
E
W
H
W
W
W
M
W
W
N
W
Test Description
As Found, Conditions
OFA Flow rate - Med OFA
- High OFA
- Low OFA
High OFA - High 02
- Med Oj
- Low O2
Low OFA - Low 02
- Med O2
- High 02
Balanced OFA
Reduced Front OFA
Reduced Rear OFA
Reduced Lower OFA
Low Load
Normal Flyash Reinjection
No Flyash Reinjection
Blr Hpr Reinjection Only
High Balanced OFA
Low Balanced OFA
Bias Upper OFA
Bias Lower OFA
Bias Front OFA
High OFA - High O2
- Med O2
- Low 02
Low OFA - High O2
- Med 02
- Low 02
Bias Rear OFA
Low Load
High OFA - High 02
- Med O2
- Low 02
Low OFA - Med O2
- Low 02
- High 02
High Balanced OFA
Low Balanced OFA
High Balanced OFA
Bias Upper OFA
Bias Lower OFA
Bias Front OFA
Bias Rear OFA
High OFA - High O2
°2
%
dry.
7.3
9.3
8.0
7.2
8.8
10.1
11.5
9.2
9.2
9.6
9.2
10.2
8.9
9.1
9.1
8.9
8.9
9.2
9.1
8.7
10.4
9.4
8.3
9.8
8.6
7.4
8.7
11.0
10.3
9.2
8.1
8.8
7.2
10.0
8.6
8.7
8.6
9.9
8.9
9.0
8.4
11.5
C02
%
dry.
12.6
9.7
11.2
11.8
10.2
9.2
7.8
10.1
10.2
10.2
10.2
8.8
10,5
10.1
10.0
10.1
10.3
10.0
10.1
10.4
8.9
10.1
11.0
10.0
11.0
12.0
10.4
8.1
9.2
10.0
11.6
11.2
12.8
9.4
10.9
10.6
11.2
9.8
10.5
10.6
10.9
8.2
CO
ppn
dry
43
62
48
45
48
132
171
57
48
55
57
65
66
55
53
53
103
49
53
37
37
23
21
37
32
26
44
68
296
168
154
259
144
361
311
488
173
395
287
567
323
232
NO
ppm
dry
274
378
360
337
303
338
418
316
321
308
290
353
288
356
333
273
230
326
328
319
282
244
227
300
233
212
326
331
355
352
350
311
288
361
387
372
358
394
387
395
408
400
Part.
Blr Out
lb/106BTU
13.1
25.0
6.0
7.0
19.0
21.1
20.9
22.6
23.9
25.1
13.2
29.2
31.1
20.4
34.0
31.6
33.1
36.4
Part.
Mech DC Out
lb/106BTU
0.82
0.48
0.50
0.69
0.64
0.94
0.78
0.84
0.88
0.51
1.04
1.03
0.55
1.04
1.03
0.94
0.74
Excess
Air
%
53
75
58
49
68
87
113
74
74
80
74
88
70
72
72
69
69
74
72
67
92
77
62
84
66
52
67
103
90
73
60
69
50
85
65
66
66
84
69
70
63
114
KVB 15900-528
8
-------
EMISSION DATA SUMMARY
TEST SITE C
(Continued)
Test
NO.
30B
30C
31A
31B
31C
32A
32B
32C
33A
33B
33C
34A
34B
34C
34D
35
36
37
38
39
40
41
42
43
44
45
46
47
48A
48B
48C
49A
49B
49C
50A
BOB
50C
Date
5/29/78
5/30/78
5/30/78
5/30/78
5/31/78
6/01/78
6/01/78
6/02/78
6/07/78
6/09/78
6/13/78
6/15/78
6/17/78
6/20/78
6/29/78
6/29/78
7/05/78
7/05/78
Load
% Coal*
55
96
96
95
55
98
98
102
58
99
78
97
97
99
93
93
58
58
W
W
W
W
W
W
W
W
H
H
H
H
W
E
E
E
E
E
Test Description
Low OFA
High OFA
Low OFA
Bias Front
Bias Rear
Bias Upper
Bias Lower
Low Load
No Flyash
- Med 02
- Low 02
- Low 02
- Med O2
- High Oj
- Low C>2
- Med 02
- High 02
- Low OFA
- Med O2
- High 02
OFA
OFA
OFA
OFA
Reinjection
02
%
dry
11.
10.
9.
10.
11.
7.
8.
9.
8.
9.
10.
8.
8.
8.
8.
10.
8.
0
0
0
0
0
2
3
1
1
0
7
6
5
4
5
6
1
C02
%
dry
8.6
9.6
10.8
10.0
8.9
12.2
11.2
10.6
10.6
10.0
8.6
11.0
11.0
11.5
11.5
9.0
11.4
CO
ppm
dry
198
151
97
151
199
163
249
334
266
421
702
327
296
294
281
182
247
NO Part. Part.
ppm Blr Out Mech IX Out
dry lb/106BTU lb/106BTU
379
361
271
312
325
301
341
334
322
346
421
357
375
337
375
300 15.2 0.36
357 8.6 0.52
Excess
Air
%
103
86
72
87
104
50
62
72
58
70
95
66
64
63
65
96
59
OFA Flow Rate - Med OFA
- High OFA
- Low OFA
Blr Hpr Reinjection Only
Low Load
High Load
Med Load
SASS, SOx'1"
SASS, SOx
SASS , SOx
, and Brink
and Brink
and Brink
8.
11.
9.
9.
8.
3
3
4
8
9
8.3
9.0
9.8
High OFA
Med OFA
Low OFA
High OFA
Low OFA
9.7
9.3
8.3
- High O2
- Med O2
- Low 02
- High O2
- Med 02
- Low O2
12.5
10.5
9.0
10.9
8.9
7.2
11.3
8.3
10.6
10.4
10.9
11.1
10.2
9.5
9.7
10.1
10.9
7.2
8.6
9.8
8.8
10.3
11.6
280
57
132
45
263
272
57
44
35
33
61
139
52
30
72
67
120
341 6.1 0.47
383 16.2 0.54
289 28.0 1.07
374 20.3 0.69
385
375
436
407
398
397
379
373
336
308
358
283
216
62
110
78
84
70
62
71
83
81
75
62
138
94
70
102
70
49
NOTES: * E - Eastern Low Fusion Coal
W - Western Coal
H - Eastern High Fusion Coal
NO2 and HC data was not obtained due to inserviceability of sampling and
analyzing equipment
* SOx data was as follows: Test 44 S02 - 969 S03 7 ppm (dry)
45 SO2 - 805 303 5 ppm (dry)
46 SO2 -1863 303 8 ppm (dry)
All parts per million (ppm) concentrations are corrected to 3% 02
KVB 15900-528
-------
SECTION 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 C. The coals utilized in
this test series are also discussed.
3.1 BOILER C DESCRIPTION
The boiler tested is a single pass two drum Stirling boiler built
by Babcock and Wilcox Company in 1975. It has continuous rating of
182,500 li>Ar steam at 875 psig and 900°F. An unusual characteristic of this
boiler is its large "nose", the intrusion on the back waterwall used to shield
the superheat pendants from radiant heat. A side elevation of the boiler is
illustrated in Figure 3-1.
The boiler is fired by a Detroit Rotograte Stoker having seven
spreaders and a traveling grate with front ash discharge. Design data on
the boiler and stoker are listed in Table 3-1. Predicted performance data is
given in Table 3-2.
The boiler's collection equipment includes a UOP multiclone dust
collector and an electrostatic precipitator. The multiclone is described in
further detail in Section 3.3, Flyash Reinjection System.
3.2 OVERFIRE AIR SYSTEM
The overfire air system on Boiler C consists of two rows of air
jets on the back wall and two rows on the front wall. The overfire air is
supplied by an independent fan and is not preheated.
The overfire air design data is as follows:
Front Upper Row: 27-3/4" jets by B&W
Spaced at 12"
6'3-1/8" above grate
25° below horizontal
KVB 15900-528
11
-------
FIGURE 3-1. SECTIONAL SIDE ELEVATION AND PLAN VIEW - TEST SITE C
A - BOILER OUTLET SAMPLING PLANE
B - MULTICLONE DUST COLLECTOR OUTLET SAMPLING PLANE
KVB 15900-528
-------
TABLE 3-1
DESIGN DATA
TEST SITE C
BOILER:
SUPERHEATER:
Type
Boiler Heating Surface
Water Wall Heating Surface
Design Pressure
Tube Diameter
Heating Surface
No. of Steam Passes
Two Drum Stirling-SPB
21,925 ft2
2,906 ft2
1,025 psig
2.5 inches
10,520 ft2
2
STEAM TEMP
CONTROL:
ECONOMIZER:
AIR HEATER:
FURNACE:
STOKER:
HEAT RATES:
Type
Location
Type
Heating Surface
Design Pressure
Tube Length
Tube Diameter
Type
Heating Surface
Volume
Flat Projected Heating Surface to Face of
Convection Surface
Spray Attemperator
Intermediate
Continuous Bare Tube
8,620 ft2
1,050 psig
28 ft
2 inches
Tubular
22,217 ft2
12,100 ft3
3,432 ft2
Type
Width
Length
Effective Grate Area
Steam Actual
Input to Furnace
Total Heat Available
Furnace Width Heat Release
Grate Heat Release
Furnace Liberation
Heat Available to Conv. Surface
Spreader with Traveling Grate
27'-1.5"
19'- 0"
515.4 ft^
182,500 Ib/hr
249xl06BTU/hr
224.9xl06BTU/hr
9.2xl06BTU/Ft Furnace Width-hr
483xl03BTU/ft2 Grate-hr
20.6xl03BTU/ft3-hr
65.2xlo3BTU/ft2-hr
13
KVB 15900-528
-------
TABLE 3-2
PREDICTED PERFORMANCE - TEST SITE C
Steam Leaving Superheater
Fuel
Excess Air Leaving Boiler
Coal Flow
Flue Gas Leaving Boiler
Air Leaving Air Heater
Steam Pressure at SH Outlet
Economizer to Drum Pressure Drop
Drum to SH Outlet Pressure Drop
Temp. Steam Leaving Superheater
Temp. Flue Gas Leaving Boiler
Temp. Flue Gas Leaving Economizer
Temp. Flue Gas Leaving Air Heater
Temp. Water Entering Economizer
Temp. Water Leaving Economizer
Temp. Air Entering Air Heater
Temp. Air Leaving Air Heater
182,500 lb/hr
Coal*
32 %
29,600 lb/hr
265,000 lb/hr
206,000 lb/hr+
875 psig
4 psig
30 psig
900 °F
622 °F
445 °F
320 °F
370 °F
437 °F
130 °F ++
302 °F
0.9 "H20
1.6 "H2O
2.2 "H20
0.8 "H20
5.5
"H20
Furnace & Convection Draft Loss
Dust Collector & Precipitator Draft Loss
Air Heater & Economizer Draft Loss
Flues to Stack Draft Loss
Net Furnace to Stack Draft Loss
Stoker Draft Loss
Air Duct Draft Loss
Air Heater Air Draft Loss
Steam Coil Air Heater Draft Loss
Net FD Fan to Furnace Draft Loss
Dry Gas Heat Loss
H2O and H2 in Fuel Heat Loss
Moisture in Air Heat Loss
Unburned Combustible Heat Loss
Radiation Heat Loss
Unaccounted for and Manufacturers Margin
Total Heat Loss
Efficiency of Unit
"'Based on 88% air leaving A.H.
++Based on Steam coil A.H. in operation
+~HBased on 0% reinjection from dust collector
*Predicted performance is based on combustion air entering at 80°F, 0.013 lb
moisture/lb dry air, 29.25 in. Hg. barometric pressure and coal fuel containing
26.5% moisture, 29.0% volatile matter, 34.4% fixed carbon, 10.1% ash,
8,419 BTU/lb
1.2 "H20
0.4 "H20
0.4 "H20
0.4 "H20++
2.4 "H20
4.5 %
7.4 %
0.1 %
4.7 %
0.4 %
1.5 %
18.6 %
81.4 %
14
KVB 15900-528
-------
Front Lower Row:
29-3/4" jets by Detroit Stoker Company
Spaced at 10-5/8"
Estimated 1'6" above grate
Angle unknown
Rear Upper Row:
28-1" jets by B&W
Spaced at alternately 13-1/2" and 9"
6'1" above grate
9° below horizontal
Rear Lower Row:
13-1-1/4" jets by Detroit Stoker
Spaced at alternately 18" and 2"3" (end jets
at 4'6")
I16" above grate
horizontal
3.3
FLYASH REINJECTION SYSTEM
Boiler C reinjects flyash continuously from the boiler hopper and
from a portion of the multiclone dust collector.
The dust collector is a UOP Design 106 Dynamic Centrifugal Collector
designed to preclean flue gas prior to an economizer. It was designed for a
medium efficiency of 87%. It has the capability of segregating the collected
flyash to a certain extent so that the larger particles - those having the
highest combustible content - are collected in the rear hoppers and reinjected
to the furnace. The finer particles are collected in the front hoppers and
discarded. The reinjected portion of the flyash represents approximately
70% of the flyash collected. The "dynamic" feature permits a slight variation
of this percentage through a simple lever adjustment.
The predicted performance of the dust collector is given below. It
is based on a flyash analyzing 35% less than ten micrometers as determined
by the Banco Analyzer Method, and corrected to a specific gravity of 2.5.
Lbs gas/hr
Operating Temperature, °F
ACFM
Collector Resistance, "H2O
Collector Efficiency
Load 1
Load 2
Load 3
433,400
600
211,700
2.85
87
396,000
650
185,920
2.38
85
290,840
620
132,734
1.28
85
15
KVB 15900-528
-------
Further design data on the flyash reinjection system is as
follows:
Boiler Hopper: Seven discharge nozzles
Spaced at 3'0" to 4'4-1/2" (variable)
1'6" above grate
4° below horizontal
Dust Collector Sixteen discharge nozzles
Hopper: Spaced at 18" to 4"8" (variable) in pairs 9" apart
1'6" above grate
4° below horizontal
3.4 TEST PORT LOCATIONS
Emission measurements were made at two locations. These were the
boiler outlet (before the multiclone dust collector) and the multiclone
outlet (after the economizer and air heater but before the ESP). The locations
of these sample points are shown in Figure 3-1. Their geometry are shown in
Figure 3-2.
Whenever particulate loading was measured, it was measured
simultaneously at both locations using 24 point sample traverses. Gaseous
measurements of O2, CO2, CO, and NO were obtained by pulling samples individually
and compositely from six probes distributed along the width of the boiler
outlet duct. SOx measurements and SASS samples for organic and trace element
determinations were obtained from a single point within the boiler outlet
duct.
A heated sample line was attached to one of the middle gaseous probes
at the boiler outlet. It's purpose was to eliminate losses due to condensation
when measuring NO2 and uriburned hydrocarbons. However, problems with the
sample line and electro mechanical problems with both the hydrocarbon analyzer
and the NOx converter prevented these measurements from being made.
16 KVB 15900-528
-------
BOILER OUTLET SAMPLING PLANE
* 4
$ $
4- 4
4
s
4
4- 4
$ $
4 4
+
$
4
111111
1
40.65"
J
224'
MULTICLONE OUTLET SAMPLING PLANE
Diameter = 89.4"
Boiler Outlet Cross Sectional Area = 63.23 ft2
Multiclone Outlet Cross Sectional Area = 43.59
KEY: + Particulate Sample Point
o Gaseous Sample Point
Figure 3-2.
BOILER C SAMPLE PLANE GEOMETRY
17
KVB 15900-528
-------
3.5 COALS UTILIZED
Three coal types were fired at Test Site C. These were an
Eastern low fusion coal, a Western coal, and an Eastern high fusion coal.
They are referred to as E, W and H coals, respectively, in the accompanying
tables and figures. Coal samples were taken for each test involving
particulate or SASS sampling. The average analyses obtained from these samples
are presented in Table 3-3. They show significant differences in moisture,
sulfur and BTU contents. The analyses for each coal sample are presented in
Section 5.0, Test Results and Observations, Tables 5-8 through 5-11.
KVB 15900-528
18
-------
TABLE 3-3
AVERAGE COAL ANALYSIS
TEST SITE C
% Moisture
% Ash
% Volatile
% Fixed Carbon
Eastern
Low Fusion
(E Coal)
5.3
11.2
35.0
48.5
BTU/lb 12260
% Sulfur 2.9
Initial Ash Deformation, °F 1985
Hardgrove Grindability Index 62
Free Swelling Index 7
Fines, % passing 1/4" 46
Western
Coal
(W Coal)
25.6
9.0
29.0
36.4
8490
0.7
2185
49
0
48
Eastern
High Fusion
(H Coal)
9.1
9.2
30.9
50.7
11850
0.9
2145
44
1
44
19
KVB 15900-528
-------
SECTION 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
(NO, N02, CO, C02, 02, HC)
A description is given below of the analytical instrumentation
and related 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 composition of the 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:
Nitric Oxide/total oxides of nitrogen (NO/NOx)
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
21 KVB 15900-528
-------
Carbon Monoxide
Beckman Model 315B NDIR Analyzer
Range: 0-500 and 0-2000 ppm'CO
Accuracy: ^1% of full scale
Carbon Dioxide
Beckman Model 864 NDIR Analyzer
Range: 0-5% and 0-20% CC>2
Accuracy: -1% of full scale
Oxygen
Teledyne Model 326A Fuel Cell Analyzer
Range: 0-5, 10 and 25% 02 full scale
Accuracy: il% of full scale
Hydrocarbons
Beckman Model 402 Flame lonization Analyzer
Range: 5 ppm full scale to 10% full scale
Accuracy: il% of full scale
The oxides of nitrogen monitoring instrument used is a Thermo
Electron chemiluminescent nitric oxide analyzer. The operational basis of
the instrument is the chemiluminescent reaction of NO and 02 to form NO2.
Light emission results when electronically excited NO2 molecules revert to
their ground state. This 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 through an air 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 downstream of a separator which insures that no water collects in
the pump.
22 KVB 15900-528
-------
The basic analyzer is sensitive only to NO molecules. To measure
NOx (i.e., NO+NO2), 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
reduced to NO molecules, and the analyzer now reads NOx. N02 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-lOV, 60 Hz, 1000 watts
Response 90% of full scale in 1 sec. (NOx mode),
0.7 sec NO mode
Output 4-20 ma
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 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 infrared 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 and
0-2000 ppm.
23 KVB 15900-528
-------
Specifications: Span Stability ±1% of full scale in 24 hours
Zero Stability -1% of full scale in 24 hours
Anfcient Temperature Range 32°F to 120°F
Line Voltage 115 ± 15 V rms
Response: 90% of full scale in 0.5 or 2.5 sec.
Precision: ±1% of full scale
Output: 4-20 ma
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
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 CX>2
analyzer are 0-5% and 0-20%.
Specifications: Span Stability ±1% of full scale in 24 hours
Zero Stability -1% of full scale in 24 hours
Ambient Temperature Range 32°P to 120°F
Line Voltage 115 - 15 V rms
Response: 90% of full scale in 0.5 or 2.5 sec.
Precision: -1% of full scale
Output: 4-20 ma
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 ©2 by
volume for operating ranges of 0% to 5%, 0% to 10%, or 0% to 25%.
24 KVB 15900-528
-------
Specifications: Precision: il% 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%-hrs.
Power Requirement: 115 VAC, 50-60 Hz, 100 watts
Output: 4-20 ma
Hydrocarbons are measured using a Beckman Model 402 hydrocarbon
analyzer which utilizes the flame ionization method of detection. The sample
is drawn through a heated line to prevent the loss of higher molecular weight
hydrocarbons to the analyzer. 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
through an electronic measuring circuit. This ionization current is pro-
portional 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 adjustment within a dynamic range of 10:1
Response Time: 90% full scale in 0.5 sec.
Precision: -1% of full scale
Electronic Stability: ±1% of full scale for
successive identical samples
Reproducibility: il% of full scale for successive
identical samples
25 KVB 15900-528
-------
Analysis Temperature: Ambient
Ambient Temp er at lire: 32°F to 110°F
Output: 4-20 ma
Air Requirements: 350 to 400 cc/min of clean,
hydrocarbon-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 Requirements: 120v, 60 Hz
Automatic Flame-out indication and fuel shut-off valve
4.1.2 Recording Instruments
The output of the four analyzers are presented on front panel
meters and are simultaneously recorded on a Texas Instrument Model FL04W6D
four-pen strip chart recorder. The recorder specifications are as follows:
Chart Size: 9-3/4 inch
Accuracy: -0.25%
Linearity: <0.1%
Line Voltage: 120V - 10% at 60 Hz
Span Step Response: 1 second
4.1.3 Gas Sampling and Conditioning System
The gas sampling and conditioning system consists of probes,
sample line, 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
contained in the emission test vehicle.
4.2 GASEOUS EMISSION SAMPLING TECHNIQUES
(NOx, CO, CO2, 02, HC)
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 Metallurgical
Corp. sintered stainless steel filter is attached to each probe for removal of
particulate material.
26 KVB15900-528
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SJ
-J
Figure 4-1. Flow schematic of mobile flue gas monitoring laboratory.
KVB 15900-528
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Gas samples to be analyzed for C>2/ 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 dia-
phragm 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 are drawn both individually and compositely from all
probes during each test. The average emission values are reported in this
report.
4.3 SULFUR OXIDES (SOx) MEASUREMENT AND PROCEDURES
Measurement of SC>2 and 803 concentrations are made by wet chemical
analysis using the "Shell-Emeryville" method. In this technique the
gas sample is drawn from the stack through a glass probe (Figure 4-2) ,
containing a quartz wool filter to remove particulate matter, into a system
of three sintered glass plate absorbers (Figure 4-3). The first two absorbers
contain aqueous isopropyl alcohol and remove the sulfur 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 re-
mainder, which passes through as a 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.
28 KVB 15900-528
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Flue Wall
Asbestos Plug
Ball Joint
Vycor
Sample Probe
Pryometer
and
Thermocouple
Figure 4-2. SOx Sample Probe Construction
Spray Trap
Dial Thermometer
Pressure Gauge
Volume Inflica
Vapor Trap Diaphragm
Pump
Dry Test Meter
Figure 4-3. Sulfur Oxides Sampling Train
29
KVB 15900-528
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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.
The inlet end of the probe holds a quartz wool filter to remove particulate
matter. It is important that the entire probe temperature be kept above
the dew point of sulfuric acid during sampling (minimum temperature of
260°C). This is accomplished by wrapping the probe with a heating tape.
Three repetitions of SOx sampling are made at each test point.
4.4 PARTICULATES 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 4-4). 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 5 micrometers and a 100 mm
glass fiber filter for retention of particles down to 0.3 micrometers. Con-
densible 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 thermister indicator. A pitot tube system is provided for setting sample
flows to obtain isokinetic sampling conditions.
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.
30 KVB 15900-528
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THERMOMETER
PROBE
THERMOMETER
PROBE
HEATED AREA
STACK
THERMOMETER
REVERSE-TYPE
PITOT TUBE
FILTER HOLDER
THERMOMETER
THERMOMETER £=
VELOCITY
PRESSURE
GAUGE
IMPINGERS ICE BATH
THERMOMETERS==-____ FINE CONTROL VALVE
VACUUM
GAUGE
CHECK VALVE
VACUUM LINE
ORIFICE
GAUGE
COARSE CONTROL VALVE
DRY TEST METER
AIR-TIGHT
PUMP
Figure 4-4. Particulate Sampling Train
31
KVB 15900-528
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4.5 PARTICLE SIZE DISTRIBUTION MEASUREMENT AND PROCEDURE
Particle size distribution is measured using several methodologies.
These include the Brink Cascade Impactor, SASS cyclones, and the Banco
Classifier. Each is discussed below.
The Brink Model "B" Cascade Impactor is a five stage, low sample
rate, cascade impactor suitable for measurements in high mass loading situations,
A schematic of the Brink sampling train is shown in Figure 4-5. Samples are
pulled isokinetically from a single sample point. The flow rate through the
/
impactor is held constant during sampling to preserve the impaction cut points.
Gelman type A-E binderless glass fiber filter paper is used as the
collection substrate. The main purpose of the glass mats is to reduce re-
entrainment due to particle bounce. The 5/8 inch diameter mats are cut from
larger stock with a cork bore and inserted in the collection plates. The
collection plates with mats installed are desiccated 24 hours before tare
weighing. After sampling, all particles adhering to the impactor walls are
brushed down onto the collection plate immediately below. The plates are
again desiccated 24 hours before weighing.
The cyclone catch is brushed onto a tare weighed paper, desiccated
and weighed. The final filter, cut from the same fiber glass stock as the
collection plate substrates, is treated the same as the collection plates.
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, thermo-
couple and indicator are used.
Second, a nozzle size is selected which will maintain isokinetic
flow rates within the recommended .02-.07 ft3/min rate at stack conditions.
Having selected a nozzle and determined the required flow rate for isokinetics,
the operating pressure drop across the impactor is determined from a cali-
bration curve. This pressure drop is corrected for temperature, pressure and
molecular weight of the gas to be sampled.
32 KVB 15900-528
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PRESSURE TAP .L
FOR 0-20" f_
KAGNAHELIX
CYCLONE
STAGE 1
STAGE 2
STAGE 3
STAGE 4
STAGE 5
FINAL FILTER
EXHAUST
1
ELECTRICALLY HEATED PROBE
DRY GAS
KETER
FLOW CONTROL
VALVE
DRYING
COLUMN
Figure 4^5. Brink cascade impactor sampling
train schematic.
KVB 15900-528
33
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The impactor is placed in the duct for 20-30 minutes prior to
sampling to allow it to be heated to stack temperature. During this warmup
period, the sample nozzle is turned away from the direction of gas flow so
that no particulates will be collected. Once hot, the stages are re-tightened
with pipe wrenches to prevent leakage. The inpactor's nozzle is then turned
into the gas stream for collecting the particulate sample.
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 re-entrainment, a rule of thumb is that no stage should be loaded
above 10 mg.
The volume of dry gas sampled is measured with a dry gas meter. This
allows calculation of actual isokinetics. The dry gas volume is also used to
convert test results to concentration units. Stack moisture used for calcu-
lating isokinetics is measured with the EPA Method 5 sample train during con-
current particulate sampling.
In addition to the Brink Cascade Impactor, particle sizing is
accomplished by several other methods. The SASS train utilizes three sized
cyclones and a final filter under controlled temperature and flow rates to
achieve gravimetric separation at ten, three and one micrometers.
Selected flyash samples are sent to an independent laboratory for
sizing using the Bahco centrifugal classifier (PTC 28).
Each of the three particle sizing methods described above has its
advantages and disadvantages. None is ideal for the intended application.
Bahco - The Bahco classifier is described in Power Test Code 28.
It is an acceptable particle sizing method in the power industry and is often
used in specifying mechanical dust collector guarantees. Its main disadvantage
is that it is a laboratory technique and is thus only as accurate as the sample
collected. Most Bahco samples are collected by cyclone separation; thus,
particles below the cut point of the cyclone are lost. The Bahco samples
collected at Test Site C came from the cyclone in the EPA Method 5 particulate
train. These samples are spatially representative because they were taken
34 KVB 15900-528
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from a 24-point sample matrix. However, much of the sample below about seven
micrometers was lost to the filter. The Bahco test data are presented in
combination with sieve analysis of the same sample. No attempt was made to
correct for the lost portion of the sample.
Brink - The Brink cascade impactor is an in-situ particle sizing
device 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 also
has some disadvantages. Because it is a single point sampler, spatial
stratification of particulate matter within the duct will yield erroneous
results. Unfortunately, the particles at the outlets of stoker boilers may be
considerably stratified. Another disadvantage is its 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.
SASS - The Source Assessment Sampling System (SASS) was not designed
principally as a particle sizer but it includes three calibrated cyclones
which are 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 one micrometers.
4.6 COAL SAMPLING AND ANALYSIS PROCEDURE
Coal samples are taken during each test from the units two coal
scales. The samples are 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 furnace 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.
35 KVB 15900-528
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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 belts discharge
end to catch all of the coal over a short increment of time (approximately
five seconds).
Sampling procedure is as follows. At the start of testing one
increment of sample is collected from each feeder. This is repeated twice more
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.
The sample to be used for sieve analysis is weighed, dried in an
oven at 220°F for about four hours, and re-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". The 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.
4.7 ASH COLLECTION AND ANALYSIS FOR COMBUSTIBLES
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 participates. The cyclone catch is placed in a desiccated
and tare weighed ceramic crucible. The crucible with sample is heated in an
36 KVB 15900-528
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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.
Bottom ash samples are collected in several increments and from
several locations along the discharge end of the grate. These samples are mixed,
quartered, and sent to Commercial Testing and Engineering Company for combustible
determination. Bottom ash samples cannot be obtained directly from the ash pit
because it is a wet hopper design.
Multiclone ash samples are taken from ports near the base of the
multiclone hopper. This sample, approximately two quarts in size, is sent to
Commercial Testing and Engineering Company for combustible determination.
4.8 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, combustible
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 form where combustible losses are lumped into
one category, combustible losses are calculated and reported separately for
combustibles in the bottom ash, combustibles in the mechanically collected ash
which is not reinjected, and combustibles in the flyash leaving the mechanical
collector.
Certain assumptions are necessary to carry out the combustible loss
calculations. The collection rate of bottom ash is based on the assumption
that 50% of the ash in the coal ends up as bottom ash. The discarded portion
of the flyash collected by the dust collector is assumed to be 30%. The
remaining 70% is reinjected according to collector design specifications. This
30-70 collector split was not confirmed by test.
37 KVB 15900-528
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4.9 MODIFIED SMOKE SPOT NUMBER
Modified Bacharach smoke spot numbers are determined using a
Bacharach field service type smoke tester. ASTM procedures for this measure-
ment apply only to oil fired units. Therefore, KVB defined its own set of
procedures which differ from ASTM D2156-65 procedure in the number of strokes
taken with the hand pump. At this test site, one,two and three strokes were
taken at the boiler outlet.
Smoke spot measurements are obtained by pulling a fixed volume of
flue gas through a standard filter paper. The color (or shade) of the spot
that is produced is matched visually with a standard smoke spot scale. The
result is a "Smoke Number" which is used to characterize the density of smoke
in the flue gas.
The sampling device is a hand pump similar to the one shown in
Figure 4-6. It is a commercially available item that with ten strokes can
pass 2,250 ±100 cubic inches of gas at 60°F and one atmosphere pressure
through an enclosed filter paper for each 1.0 square inch effective surface
area of the filter paper.
Sampling Tube,
i
1 ' .1
1
Filter Paper
Plunger
Handle
Figure 4-6. Field Service Type Smoke Tester
38
KVB 15900-528
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4.10 TRACE SPECIES MEASUREMENT
The EPA (IERL-RTP) has developed the Source Assessment Sampling
System (SASS) train for the collection of participate 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 Um B) 3 Urn to 10 Urn C) 1 urn to 3 Urn
Together with a filter, a fourth cut (.
-------
Convection
oven
Miter
Stack T.C.
Gas cooler
S-type pHot
1 » J_LJ
SUck velocity (&f>)
magnehellc gauges
Sorbent
cartrldi
trace element
collector
Coarse adjustment
Fine
adjustment
valve
Vacuum pumps
Orifice AHf
magnehellc gauge
Dry test meter
FIGURE 4-7. Source Assessment Sampling System (SASS) Flow Diagram
KVB 15900-528
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Secondly, the plates beneath the venturi sections of the reinjection
lines were removed. Several layers of heavy aluminum foil were wrapped around
the venturi sections so that no flyash could enter the reinjection line.
Instead, the flyash would fall straight on through to the floor of the boiler
room.
Thirdly, tare weighed barrels were placed under each reinjection
venturi section for collection of the flyash. The boiler hopper downspouts
had rotary air seals which prevented the ambient air from entering the boiler
hopper through the open lines.
The time each barrel was placed under the open downspout and the time
each was removed was recorded. From this data, the flyash collection rate was
measured from each line individually and from the boiler hopper as a whole.
It is understood that the collection rates are not the same as the reinjection
rates would be under the same firing conditions. This is because reinjecting
flyash increases the particulate loading through the boiler which, in turn, would
undoubtedly increase the flyash reinjection rate.
It is believed that following these procedures prevented any of the
boiler hopper flyash from being reinjected to the boiler. In other words,
a true 0% boiler hopper reinjection rate was established for test purposes.
The procedure for altering the flyash reinjection rate from the
multiclone dust collector differed from that of the boiler hopper. Multiclone
hopper ash was diverted to a storage bin by means of a set of gate valves on
each downspout. This bin had no observation ports on it or other means of
determining collection rate. Therefore, the collection rate of the multiclone
hopper was determined by measuring the dust loading entering and leaving the
multiclone. This was accomplished by running two EPA Method 5 Particulate
sampling trains simultaneously across the dust collector.
It is believed that these procedures produced a true 0% multiclone
ash reinjection configuration.
41 KVB 15900-528
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SECTION 5.0
TEST RESULTS AND OBSERVATIONS
This Section presents the results of the tests performed on Boiler
C. Observations are made regarding the influence on gaseous and particulate
emissions and efficiency as the control parameters were varied. Fifty tests
were conducted in a defined test matrix to develop this data. Data tables
5-18 through 5-22 are included at the end of this section for reference.
5.1 OVERFIRE AIR
The most extensively studied variable on Boiler C was overfire air.
It was increased, decreased, biased front, rear, upper and lower in a program
designed to determine which row(s) of jets most effectively reduce emissions
and increase combustion efficiency.
The overfire air tests were duplicated on two coals. They were
first run on Eastern low fusion coal, and then repeated on Western coal. The
air flow rates through each row of overfire air and flyash reinjection jets
were measured as functions of static pressure in the air ducts.
Test data indicates that the lower rear row of air jets was most
effective in reducing carbon monoxide, but was also responsible for an increase
in nitric oxide emissions. Particulate loadings were lowest when overfire air
flow was highest. These results are discussed in detail in the following sub-
sections. The first subsection discusses the overfire air system and how the
air flow rates were measured.
5.1.1 Overfire Air Flow Rate Determination
Overfire air flow rates and flyash reinjection air flow rates were
carefully measured at three overfire air (OFA) settings corresponding to 5, 15
KVB 15900-528
43
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and 25" I^O pressure at the fan. This test data was used to generate a set
of curves relating static pressure of the various OFA ducts to their corres-
ponding air flow rates in Ib/hr. Having established the pressure-flow
relationships, the overfire air injection rates to the furnace were determined
for each test based on the duct static pressures.
The overfire air flow determinations were made during tests 2, 3,
and 4 on April 19, 1978, and again during test 37, 38 and 39 on June 1, 1978.
Test results for both dates were similar. Only the April 19 test results will
be presented here.
Velocity measurements were made at the locations shown schematically
in Figure 5-1. Each overfire air header was fed from both ends so that velocity
measurements were required at both ends. Each of the ten measurement locations
was traversed with a standard pitot tube. A twelve or sixteen point traverse
was used depending on duct diameter, and was made from two angles 90° apart.
The measured velocities were converted to pounds per hour air flow.
The results are shown in Table 5-1 for the case where the air pressures to the
individual air headers (i.e., front upper, front lower, etc.) are approximately
balanced. The front lower overfire air header feeds cooling air to the coal
feeder tuyeres and air swept cut-off plates in addition to a row of underfeeder
air jets. Therefore, its air flow rate is higher than the others. With this
one exception, the balance is quite good.
Overfire air flow rates are related to overfire air pressures by
Bernoulli's equation for fluid flow through an orifice. One form of this
equation is:
AP _ Av2
p ~ 2g
The velocity (v) is proportional to the square root of the pressure drop (AP).
Therefore, the air flow rate in Ib/hr should be nearly proportional to the
square root of the static pressure in the overfire air jet headers. This
relationship held true as shown in Figures 5-2 and 5-3. With these pressure
flow relationship plots, the overfire air and reinjection air flow rates can
be determined for any set of conditions. All that is required are the static
pressures in the ducts of interests.
KVB 15900-528
44
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FU = Front Upper
PL = Front Lower
RU = Rear Upper
RL = Rear Lower
Front Upper
Sample Plane"
o
FU OFA
FL OFA
RU OFA'
RL OFA
REINJECTION
_Front Main
Sample Plane
Rear Main _
Sample Plane
. Rear Upper
Sample Plane
Reinjection Main
Sample Plane
FIGURE 5-1.
OVERFIRE AIR AND REINJECTION AIR FLOW SCHEMATIC
45
KVB 15900-528
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TABLE 5-1
OVERFIRE AIR AND REINJECTION AIR FLOW R
TEST SITE C
Main Duct
Front QFA
Rear OFA
Reinjection Air
Main Duct
Front OFA
Rear OFA
Reinjection Air
Main Duct
Front OFA
Rear OFA
Reinjection Air
5"
Air Flow
Ib/hr
17309
8375
10158
15"
Air Flow
Ib/hr
32921
15850
15611
25"
Air Flow
Ib/hr
41966
20001
17349
H2O OVERFIRE
Split
48%
24%
28%
H2O OVERFIRE
Split
51%
25%
24%
H20 OVERFIRE
Split
53%
25%
22%
AIR PRESSURE
Branch Duct
Front Upper
*Front Lower
Rear Upper
*Rear Lower
AIR PRESSURE
Branch Duct
Front Upper
*Front Lower
Rear Upper
*Rear Lower
AIR PRESSURE
Branch Duct
Front Upper
*Front Lower
Rear Upper
*Rear Lower
Air Flow
Ib/hr
3386
13923
3844
4531
Split w/o
Reinjection
Air
13%
54%
15%
18%
Split w/o
Air Flow Reinjection
Air
13%
55%
14%
18%
6300
26621
7053
8797
Split w/o
Air Flow Reinjection
Air
13%
54%
16%
16%
8287
33679
9919
10082
*Determined by Difference, Not Measured
46
KVB 15900-528
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-.
J
D
10
20
30 40 50
AIR FLOW RATE, 103LB/HR
60
70
FIGURE 5-2 PRESSURE - FLOW RELATIONSHIP, OFA SYSTEM
TEST SITE C
KVB 15900-528
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o
CM
EC
.-
6 8 10
AIR FLOW RATE, 103 LB/HR
12
FIGURE 5-3 PRESSURE - FLOW RELATIONSHIP, OFA SYSTEM
TEST SITE C
KVB 15900-528
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80 60 40 20 0
EXCESS AIR, PERCENT
FIGURE 5-4
80
100
120 140 160
BOILER LOAD, LB/HR STEAM
180
CONTRIBUTION OF OVERFIRE AIR AND REINJECTION AIR TO TOTAL COMBUSTION AIR
TEST SITE C
KVB 15900-528
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The percentage of contoustion air introduced into the furnace above
the grate was determined. This was accomplished by calculating the Ib/hr gas
flow through the furnace and comparing it to the measured overfire air and
reinjection air flow rates.
A nomograph which relates overfire air pressure to air flow rates
is given in Figure 5-4. With this nomograph, the combined contribution from
overfire air and flyash reinjection air to total combustion air can be deter-
mined for any boiler load. The only data required are excess air, and overfire
air pressure from the panel board draft gauge. According to this nomograph, at
maximum load and 30% excess air the maximum contribution to combustion air
from the overfire/reinjection air system is about 33%.
5.1.2 Particulate Loading vs Overfire Air
Six particulate tests were run on Eastern low fusion coal and six
on Western coal to determine the effect overfire air has on particulate
emissions. During each test, the overfire air flow was biased in a different
way, i.e., all four rows at high pressure, all at low pressure, upper two
rows high pressure with lower two rows low pressure, etc. The test data is
presented in Tables 5-2 and 5-3, and in Figures 5-5 and 5-6.
Attempts were made to maintain overfire air flow as the only variable
Thus, loads were held constant and excess oxygen was maintained at -0.25% with
the exception of test 26, which was one percent high in excess 02-
Use was made of the measured pressure-flow relationships for the
overfire air system which were discussed in Section 5.1.1. As noted in
Tables 5-2 and 5-3, a large change in OFA pressure (i.e., 20" H2O to 5" H2O)
results in a smaller change in actual air flow (i.e., 5% to 2.5% of theoretical
air).
Test results showed that varying the overfire air on Boiler C had
little discernable effect on particulate loading. When the overfire air was
lowered from maximum to minimum, particulate loading at the boiler outlet
KVB 15900-528
50
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increased 11% on Eastern coal (Tests 12 and 13) and increased 8% on Western
coal (Tests 23 and 24). Accuracy of the measurements is probably in the range
of 15%. For this reason, small changes on the order of ten percent or less
require a large number of tests to establish that observed trends are real.
In like manner, biasing upper, lower, front and rear overfire air
flows had little discernable effect on particulate loading. Biasing upper
overfire air versus lower overfire air resulted in an eight percent decrease
in particulate loading on Eastern coal and an eight percent increase in particu-
late loading on Western coal. Such inconsistency can be viewed as normal scatter
in the data. Biasing front OFA versus rear OFA decreased particulate loading
at the boiler outlet by five percent and ten percent for the Eastern and Western
coals, respectively. Again, the changes are not statistically significant.
The multiclone outlet particulate loadings for these tests do not
follow the trends of the boiler outlet loadings. This reaffirms the conclusion
that the changes in particulate loading were masked by normal scatter in the
data. It is noted, however, that the lowest particulate loading occurred under
"high balanced" overfire air conditions during both test series.
5.1.3 Nitric Oxide vs Overfire Air
Definite trends were established in nitric oxide emissions as the
overfire air conditions were changed. These trends, however, were slight and
were partially masked by the small variations in excess oxygen.
The excess oxygen variable was eliminated by first establishing the
average NO-C>2 trend as a 30 ppm increase in NO for each one percent increase
in excess 02- (Refer to Section 5.3.3 and Figure 5-23 for the basis of this
NO-O2 relationship.) Each measured NO value was corrected to 9% ©2 using this
relationship. In those cases where an NO-O2 curve was already established
(i.e., tests 5 A-C, 6 A-C, etc.), the nine percent 02 intercept value was used.
The corrected test results are presented in Table 5-4 and Figure
5-7. An increase in overfire air pressure from a low of 5" H20 to a high of
25" H20 resulted in an average increase in nitric oxide concentration of
nine percent ±12%. Putting most of the overfire air through the lower rows
KVB 15900-528
51
-------
TABLE 5-2
EFFECT OF OVERFIRE AIR ON EMISSIONS & EFFICIENCY
EASTERN LOW FUSION COAL - TEST SITE C
Test No.
Description
OVERFIRE AIR CONDITIONS
Front Upper, "H20/% Theoretical Air
Front Lower, "H20/% Theoretical Air
Rear Upper, "H20/% Theoretical Air
Rear Lower, "H20/% Theoretical Air
Reinjection, "H20/% Theoretical Air
Total Above Grate Air, % Theoretical Air
Total Undergrate Air, % Theoretical Air
Total Combustion Air, % Theoretical Air
FIRING CONDITIONS
Coal Supplier*
Load, % of Capacity
Grate Heat Release, 103BTU/ft2/hr
Coal Sizing, % Passing 1/4"
Excess Air, %
BOILER OUTLET EMISSIONS
P articulate Loading, lb/106BTU
Conbustible Loading, lb/106BTU
Inorganic Ash Loading, Ib/lO^TU
Conbustibles in Flyash, %
02, % (dry)
CO, ppm (dry) 9 3% O2
SO, ppm (dry) 9 3% O2
MULITCLONE OUTLET EMISSIONS
Particulate Loading, Ib/lO^BTU
Combustible Loading, li>/106BTU
Inorganic Ash Loading, lb/106BTU
Combustibles in Fly ash, %
Multiclone Collection Efficiency,
HEAT LOSSES, t
Dry Gas Loss
Moisture in Fuel
f<20 from Combustion of H2
Conbustibles in Collected Flyash
Combustibles in Emitted Flyash
Combustibles in Bottom Ash
Radiation Loss
Unmeasured Losses
Total Losses
Boiler Efficiency
12
High
Balanced
OFA
17.2/4.4
17.1/20.9
18.0/5.0
15.7/5.8
17.0/9.4
45.5
123.8
169.3
E
93
433
42
69
19.0
9.1
9.9
47.8
8.9
53
273
0.69
0.11
0.58
16.5
96.4
8.02
0.57
4.50
2.40
0.17
1.29
0.42
1.50
18.87
81.13
13
Low
Balanced
OFA
5.8/2.6
5.9/12.8
6.1/2.9
5.6/3.9
9.0/6.9
29.1
140.3
169.4
E
91
400
46
69
21.1
6.5
14.6
30.8
8.9
103
230
0.64
0.16
0.48
25.3
97.0
8.28
0.59
4.72
5.14
0.25
1.62
0.44
1.50
22.54
77.46
14
Bias
Upper
OFA
20.2/4.8
6.2/13.0
20.2/5.4
5.8/3.9
17.8/6.3
33.4
140.2
173.6
E
93
431
47
74
20.9
5.1
15.8
24.4
9.2
49
326
0.94
0.19
0.75
19.8
95.5
7.89
0.32
4.33
2.01
0.27
0.13
0.42
1.50
16.87
83.13
15
Bias
Lower
OFA
5.7/2.6
15.4/20.4
4.9/2.6
14.4/5.8
16.3/9.5
40.9
131.3
172.2
E
91
425
47
72
22.6
10.4
12.2
46.0
9.1
53
328
0.78
0.16
0.63
19.8
96.5
7.98
0.43
4.38
1.80
0.23
0.09
0.44
1.50
16.85
83.15
16
Bias
Front
OFA
15.0/4.1
15.0/18.6
5.0/2.6
5.1/3.7
16.3/9.3
38.3
128.5
166.8
E
93
417
49
67
23.9
13.3
10.5
55.9
8.7
37
319
0.84
0.14
0.70
16.9
96.5
7.71
0.41
4.42
2.32
0.22
0.37
0.42
1.50
17.37
82.63
19
Bias
Rear
OFA
2.1/1.6
2.1/7.6
22.2/5.2
17.5/7.1
17.6/9.6
31.1
135.7
166.8
E
92
418
43
67
25.1
10.5
14.7
41.6
8.7
44
326
0.88
0.15
0.73
17.4
96.5
8.08
0.46
4.41
2.55
0.23
1.38
0.42
1.50
19.03
80.97
E - Eastern Low Fusion Coal
KVB 15900-528
52
-------
COMBUSTIBLE FRACTION
INORGANIC ASH FRACTION
EH
ffl
25
20
15
10
I :
: -
m
5
:.
...
V-
Q
<
.
i
BC
'
; ;
8
:"''
;
::
a
i
TEST
12 13
14 15
16 19
FIGURE 5-5 PARTICULATE LOADING BROKEN DOWN INTO COMBUSTIBLE
AND INORGANIC FRACTIONS FOR THREE OVERFIRE AIR
TEST SETS ON EASTERN LOW FUSION COAL -
TEST SITE C
KVB 15900-528
53
-------
TABLE 5-3
EFFECT OF OVERFIRE AIR ON EMISSIONS & EFFICIENCY
WESTERN COAL - TEST SITE C
Test No.
Description
OVERFIRE AIR CONDITIONS
Front Upper, "H2O/» Theoretical Air
Front Lower, "H20/% Theoretical Air
Rear Upper, "H2O/% Theoretical Air
Rear Lower, "H2O/% Theoretical Air
Reinjection, "H20/% Theoretical Air
Total Above Grate Air, % Theoretical Air
Undergrate Air, % Theoretical Air
Total Combustion Air, % Theoretical Air
FIRING CONDITIONS
Load, % of Capacity
Grate Heat Release, 103BTU/ft2/hr
Coal Sizing, % passing 1/4"
Excess Air, %
BOILER OUTLET EMISSIONS
Participate Loading, Ib/lO^TO
Combustible Loading, lb/106BTU
Inorganic Ash Loading, lb/10bBTU
Combustibles in Flyash, t
02, % (dry)
CO, ppm (dry) @ 3% O2
NO, ppm (dry) @ 3% O2
MULTICLONE OUTLET EMISSIONS
Participate Loading, Ib/lO^TU
Combustible Loading, lb/106BTU
Inorganic Ash Loading, lb/106BTU
Combustibles in Flyash, %
Nulticlone Collection Efficiency, %
HEAT LOSSES, %
Dry Gas Loss
Moisture in Fuel
H20 from Combustion of Hj
Combustibles in Collected Flyash
Combustibles in Emitted Flyash
Contmstibles in Bottom Ash
Radiation Loss
Unmeasured Losses
Total Losses
Boiler Efficiency
23
High
Balanced
OFA
17.7/4.3
18.0/20.0
19.6/5.0
16.2/5.5
17.2/8.8
43.6
121.8
165.4
100
491
48
65
29.2
2.5
26.7
8.7
8.6
311
387
1.04
0.08
0.96
7.5
96.4
8.01
3.47
6.29
0.97
0.11
1.55
0.40
1.50
22.30
77.70
24
Low
Balanced
OFA
4.3/2.1
4.8/10.7
5.1/2.5
5.6/3.7
18.6/9.2
28.2
137.8
166. 0
98
480
42
66
31.1
--
8.7
488
372
1.03
0.06
0.96
6.2
96.7
7.90
3.52
6.16
0.50
0.10
1.44
0.40
1.50
21.52
78.48
26
Bias
Upper
OFA
17.5/4.2
3.6/9.1
18.0/4.7
3.9/3.0
16.1/8.6
29.6
154.2
183.8
99
481
52
84
34.0
4.1
29.9
12.1
9.9
395
394
1.04
0.07
0.97
6.3
96.9
8.74
3.64
6.28
0.62
0.09
0,45
0.40
1.50
21.72
78.28
27
Bias
Lower
OFA
4.5/2.1
16.7/19.2
4.4/2.3
15.7/5.4
18.1/8.5
37.5
131.7
169.2
100
459
42
69
31.6
3.7
27.9
11.7
8.9
287
387
1.03
0.08
0.95
7.3
96.7
8.07
3.06
6.02
0.56
0.12
2.45
0.40
1.50
22.18
77.82
28
Bias
Front
OFA
16.0/2.9
16.0/19.0
5.3/2.5
4.3/3.2
18.0/8.6
36.2
133.9
170.1
99
491
59
70
33.1
2.3
30.7
7.1
9.0
567
395
0.94
0.06
0.88
6.3
97.2
7.83
3.64
6.49
0.62
0.09
2.04
0.40
1.50
22.61
77.39
29
Bias
Rear
OFA
4.7/2.2
4.2/9.7
18.3/4.7
15.2/4.7
17.9/8.6
29.9
132.8
162.6
100
494
49
63
36.4
8.4
323
408
0.74
0.03
0.71
3.6
98.0
7.54
3.52
6.25
0.50
0.04
0.49
0.40
1.50
20.24
79.76
KVB 15900-528
54
-------
I i
30
a
25
20
15
COMBUSTIBLE FRACTION
TOTAL PARTICULATE LOADING
COMBUSTIBLE FRACTION NOT DETERMINED
INORGANIC ASH
FRACTION
:
.,
ft,
O
OJ
TEST 23 24
26 27
28 29
FIGURE 5-6 PARTICULATE LOADING BROKEN DOWN INTO COMBUSTIBLE AND
INORGANIC FRACTIONS FOR THREE OVERFIRE AIR TEST SETS
ON WESTERN COAL TEST SITE C
KVB 15900-528
55
-------
of jets resulted in a six percent -4% higher concentration of nitric oxide
than the reverse, and putting most of the overfire air through the rear jets
resulted in a six percent ±3% higher NO concentration than the reverse.
Normal operating condition for this boiler is 15-20" J^O at full load.
To summarize, increased use of overfire air increases nitric oxide
formation in Boiler C and the lower and rear air jets seem to be most responsible
for this increase.
5.1.4 Carbon Honoxide vs Overfire Air
Carbon monoxide emissions were reduced an average 30% when overfire
air was increased from its minimum to its maximum flow. This average reduction
in CO concentration was true for both coals even though the average concen-
tration of CO for the Eastern low fusion coal was significantly lower than for
the Western coal. The data is presented in Table 5-5 and Figure 5-8.
The variable excess 02 was "corrected out" of the CO data in a
manner similar to the way it was corrected out of the NO data. Carbon monoxide
concentrations were observed to increase with increasing excess Oo in the
range of 7-12% ©2- The CO-O2 relationship in this region was well defined.
Therefore, it became possible to correct for the variable excess 02 and
thereby simplify the data.
To summarize, overfire air effectively reduced carbon monoxide
formation in Boiler C and the lower rear air jets were most responsible for
this reduction.
5.1.5 Boiler Efficiency vs Overfire Air
Overfire air did not affect boiler efficiency in the load range and
excess air range tested. However, low overfire air conditions did result in a
smoky plume and it was evident that overfire air was necessary for satisfactory
stoker operation.
Heat loss and boiler efficiency numbers are included in Tables 5-2
and 5-3.
KVB 15900-528
56
-------
TABLE 5-4
NITRIC OXIDE EMISSIONS VS OVEKFIRE AIR
TEST SITE C
High Balanced OFA vs Low Balanced OFA
Nitric Oxide, ppm (dry) @ 3% 02*
Percent
Low OFA High OFA Change
Test
Np_._
5-6
12-13
17-18
21-22
23-24
30-31
49-50
48A-48C
Coal
E
E
E
W
W
W
E
E
Load, %
94
92
76
77
99
57
58
93
308
233
257
320
381
271
287
400
374
276
237
352
399
331
308
377
Mean
Standard Deviation
High Upper Front and Rear OFA vs High Lower Front and Rear OFA
Nitric Oxide, ppm (dry) @ 3% 02*
Test
No.
Coal
E
W
W
Load,%
92
100
95
High
Upper OFA
320
367
355
High Percent
Lower OFA Change
325
390
390
Standard
+2
+6
+10
Mean +6
Deviation 4%
High Front Upper and Lower OFA vs High Rear Upper and Lower OFA
Nitric Oxide, ppm (dry) @ 3% 02*
Test
No. Coal Load,%
E
E
W
W
93
92
99
95
High
Front OFA
290
328
395
369
High Percent
Rear OFA
315
335
426
390
Mean
Standard Deviation
Change
+9
+2
+8
+6
+6
3%
* Nitric Oxide concentrations were corrected for the effect of oxygen
to a constant 9% 02 by applying the factor 30 ppm increase in NO
for each one percent increase in 02
57
KVB 15900-528
-------
CN
O
df
ro
<3J
0.
u
H
0
n
04
(X,
w
Q
H
X
o
0
400
300
200
100
n
|^| LOW BALANCED OFA
P^ HIGH BALANCED OFA
^
-
1
M
1
1
i
1
imm.
1
mm
1
mm
I
TEST NO. 56 1213 17 18 2122 2324 3031 4950 48A 48C
400
300
200
100
|^ HIGH UPPER OFA ^J HIGH FRONT OFA
ft HIGH LOWER OFA F*J HIGH REAR OFA
___ ^
-
1
1
1
1
mm
1
mm
Rn
mm
^^^^K.
\
TEST NO. 14 15 26 27 34C 34D 7B 7C 16 19 28 29 34A 34B
FIGURE 5-7 NITRIC OXIDE EMISSIONS VS OVERFIRE AIR
TEST SITE C
58
-------
TABLE 5-5
CARBON MONOXIDE EMISSIONS VS OVERFIRE AIR
TEST SITE C
High Balanced OFA vs Low Balanced OFA
Coal
E
E
E
W
W
W
W
E
E
Load, %
97
92
76
77
99
59
96
93
58
Carbon Monoxide, ppm (dry) @ 3% O?*
Percent
Low OFA High OFA change
55
103
33
273
488
100
420
69
66
55
53
23
163
311
100
320
32
30
Mean
Standard Deviation
High Upper Front and Rear OFA vs High Lower Front and Rear OFA
Test
No.
14-15
26-27
34C-34D
Coal
E
W
W
Load,%
92
100
95
Carbon Monoxide, ppm (dry) @ 3% O?*
High
Upper OFA
48
314
347
High Percent
Lower OFA Change
53
294
323
Mean
Standard Deviation
+10
-6
-7
-1%
10%
High Front Upper and Lower OFA vs High Rear Upper and Lower OFA
Carbon Monoxide, ppm (dry) @ 3% O?*
High High Percent
No. Coal Load,% Front OFA Rear OFA Change
34A-34B
E
E
W
W
93
92
99
95
52
38
569
358
47 -10
45 +18
380 -33
332 _ -2
Mean -8%
Standard Deviation 21%
* Carbon Monoxide concentrations were corrected for the effect of
oxygen to a constant 9% O2 by applying the CO-02 relationship
found in Figures 5-23 and 5-24.
59
KVB 15900-528
-------
400
fM
O
(*)
ca
CARBON MONOXIDE, PPM
M to U
3000
0 0 0
Jjj LOW BALANCED OFA
f"l HIGH BALANCED OFA
'^
:
TEST NO. 5 6 12 13
400
CN
O
CARBON MONOXIDE, PPM <3 3% '
M K> U>
O O O O
0 O O
Eh
17 18
1
21
K<
22
HHIGH UPPER OFA
PI HIGH LOWER OFA
"
' 1
f\ 1
TEST NO. 14 15 26 27
t\
34C 34D
i
!
^^^
n
1
M
i
23 24 30 31 32 33 48A 48C 49 50
BHIGH
rn HIGH
FRONT OFA
REAR OFA
1
1
NI
1
7B 7C 16 19 28 29 34A 34B
FIGURE 5-8 CARBON MONOXIDE EMISSIONS VS OVERFIRE AIR
TEST SITE C
60
-------
5.2
FLYASH REINJECTION
Tests for emissions and efficiency were run under three configur-
ations of the boiler's flyash reinjection system. These configurations were:
1. Full Reinjection - This is the normal configuration which
includes full reinjection from the boiler hopper and partial
reinjection from the segregating multiclone dust collector.
(It is assumed that 70% of the multiclone hopper ash is rein-
jected, based on multiclone design specifications, unless
otherwise stated.)
2. Boiler Hopper Reinjection - All ash collected by the multiclone
dust collector is diverted to the plant's wet slurry system.
3. No Reinjection - In addition to diverting the multiclone ash
away from the furnace, all the boiler hopper ash is collected
in barrels and its collection rate is measured.
This series of reinjection tests was run on both the Eastern Low Fusion coal
and the Western coal. A detailed description of test procedures is given in
Section 4.11. The test results are summarized in Tables 5-6 and 5-7. Dis-
cussion of these results follows.
Particulate loadings at both the boiler outlet and the multiclone
outlet were dramatically reduced when flyash reinjection was stopped. At the
boiler outlet the reductions were on the order of 75%, at the multiclone outlet,
45%. The following table further illustrates the magnitude of the reductions.
PARTICULATE LOADING VS REINJECTION CONFIGURATION
E. Coal, Blr Out, lb/106BTU
W. Coal, Blr Out, lb/106BTU
E. Coal, D.C. Out, lb/106BTU
W. Coal, D.C. Out, lb/106BTU
Full
Reinj .
25.0
31.1
0.82
1.03
Blr Hpr
Reinj .
7.0
6.2
0.50
0.47
NO
Reinj .
6.0
8.6
0.48
0.52
In Figures 5-9 and 5-10, the flyash flow rates in Ib/hr are
schematically illustrated for the different reinjection configurations. The
rates shown at the boiler outlet, multiclone collector outlet and boiler hopper
were directly measured. The collection rate of the multiclone is determined
61
KVB 15900-528
-------
TABLE 5-6
EFFECT OF FLYASH REINJECTION ON EMISSIONS AND EFFICIENCY
BURNING EASTERN LOW FUSION COAL
TEST SITE C
Fly ash Rein ject ion Rate
FIRING CONDITIONS
Coal Supplier
Load, % of Capacity
Grate Heat Release, lO^TU/ft2/!^
Coal Sizing, % passing 1/4"
Excess Air, %
BOILER OUTLET EMISSIONS
Particulate Loading, Ib/lO^BTU
Combustible Loading, Ib/lO^TU
Inorganic Ash Loading, lb/106BTU
Combustibles in Flyash, %
02, % (dry)
CO, ppm (dry) @ 3% 02
NO, ppm (dry) @ 3% 02
MULTICLONE OUTLET EMISSIONS
Particulate Loading, lb/106BTU
Conbustible Loading, Ib/lO^TU
Inorganic Ash Loading, Ib/lO^TU
Combustibles in Flyash, %
Multiclone Collection Efficiency, %
HEAT LOSSES, %
Dry Gas Loss
Moisture in Fuel
H20 from Combustion of H2
Combustibles in Collected Flyash*
Combustibles in Emitted Flyash
Combustibles in Bottom Ash
Radiation Loss
Unmeasured Losses
Total Losses
Boiler Efficiency
Test No. 9
Full
E
89
397
52
70
25.00
8.9
66
288
0.815
0.142
0.673
17.4
96.7
7.56
0.56
4.59
3.43
0.21
0.05
0.44
1.50
18.34
81.66
Test No. 11
Boiler
Hopper Only
E
93
440
50
72
7.00
4.00
3.00
57.2
9.1
53
333
0.496
0.143
0.353
28.9
92.9
8.12
0.63
4.56
3.86
0.19
0.10
0.42
1.50
19.38
80.62
Test No. 10
None
E
93
451
43
72
6.02
^mm
9.1
55
356
0.481
0.114
0.367
23.6
92.0
7.92
0.62
4.53
2.32
0.15
0.15
0.42
1.50
17.61
82.39
* Based on 70% reinjection from the dust collector
62
KVB 15900-528
-------
TEST 9
FULL HEINJECTION
163,000 Ib/hr steam
17,100 Ib/hr coal
(9.55 Ib steam/lb coal)
FURNACE
BOILER
HOPPER
MULTICLONE
COLLECTOR
5116 Ib/hr-*
167
3464* Ib/hr
W
1485 Ib/hr
TEST 11
BOILER HOPPER REINJECTION
170,000 IbAr steam
18,900 Ib/hr coal
(8.99 Ib steam/lb coal)
1474 IbAr
TEST 10
NO REINJECTION
170,000 IbAr steam
19,200 IbAr coal
(8.84 Ib steam/lb coal)
112 IbAr*
1289 IbAr
Assuming 70% Reinjection
FIGURE 5-9 FLYASH FLOW RATES WITH DIFFERENT REINJECTION CONFIGURATIONS
EASTERN LOW FUSION COAL - TEST SITE C
63
KVB 15900-528
-------
TABLE 5-7
EFFECT OF PLYASH REINJECTION ON EMISSIONS AND EFFICIENCY
BURNING WESTERN COAL
TEST SITE C
Flyash Re injection Rate
FIRING CONDITIONS
Coal Supplier
Load, % of Capacity
Grate Heat Release, 10%TD/ft^/hr
Coal Sizing, % passing 1/4"
Excess Air, %
BOILER OUTLET EMISSIONS
Particulate Loading, Ib/lO^TU
Combustible Loading, lb/106BTU
Inorganic Ash Loading, Ib/lO^TU
Combustibles in Flyash, %
02, % (dry)
CO, ppm (dry) @ 3% O2
NO, ppm (dry) @ 3% O2
HULTICLONE OUTLET EMISSIONS
Particulate Loading, Ib/lO^TU
Combustible Loading, lb/106BTU
Inorganic Ash Loading, Ib/lO^TU
Combustibles in Flyash, %
Mult i clone Collection Efficiency, %
HEAT LOSSES, %
Dry Gas Loss
Moisture in Fuel
H2O from Combustion of H2
Combustibles in Collected Flyash*
Combustibles in Emitted Flyash
Combustibles in Bottom Ash
Radiation Loss
Unmeasured Losses
Total Losses
Boiler Efficiency
Test No. 24
Full
W
98
480
42
66
31.14
8.7
488
372
1.025
0.064
0.961
6.2
96.7
7.90
3.52
6.16
0.50
0.10
1.44
0.40
1.50
21.52
78.48
Test No. 40
Boiler
Hopper Only
W
102
499
46
62
6.15
__
8.3
280
341
0.466
0.058
0.408
12.4
92.4
7.54
3.57
6.29
1.45
0.09
0.02
0.40
1.50
20.86
79.14
Test No. 36
None
W
98
482
49
59
8.57
_..
8.1
247
357
0.519
0.071
0.448
13.7
93.9
7.39
3.57
6.27
1.26
0.11
0.20
0.40
1.50
20.70
79.30
* Based on 70% reinjection from the dust collector
64
KVB 15900-528
-------
TEST 24
FULL REINJECTION
179,000 Ib/hr steam
29,000 Ib/hr coal
(6.19 Ib steam/lb coal)
FURNACE
BOILER
HOPPER
MULTICLONE
COLLECTOR
7699 lb/hr+
253 lb/hr-»-
\/
5212*lb/hr
2234 Ib/hr
TEST 40
BOILER HOPPER REINJECTION
186,000 Ib/hr steam
30,600 Ib/hr coal
(6.10 Ib steam/U> coal)
1583 lb/hr->
120 lb/hr->-
1463 Ib/hr
TEST 36
NO REINJECTION -
178,000 Ib/hr steam
29,600 IbAr coal
(6.03 Ib steam/lb coal)
2126 lb/hr-> 129 Ib/hr*
325 Ib/hr
1997
* Assuming 70% Reinjection
FIGURE 5-10 FLYASH FLOW RATES WITH DIFFERENT REINJECTION CONFIGURATIONS
WESTERN COAL - TEST SITE C
65
KVB 15900-528
-------
by difference of the inlet and outlet rates. It was assumed (based on
design data) that 70% of the multiclone ash was deposited in the back hopper
and 30% in the front. Hie back hopper ash is normally reinjacted. The
measured rates may be considered accurate to two significant digits at best.
The Bahco Classifier was used to determine particle size distri-
butions at the boiler outlet for selected tests. In Figures 5-11 and 5-12,
the Bahco data was combined with the particulate loading data to form particle
size concentration plots. This was done for the conditions of full reinjection
and no reinjection on both coals. These figures graphically illustrate that
the bulk of particulate mass is in the size range of 50-500 micrometers with
peak concentrations near 100 micrometers.
Figure 5-13 shows that when flyash reinjection is stopped, the
greatest reductions in particulate loading are in the size range of 20-300
micrometers where they average about 80%. Below 20 micrometers the mass
reduction is closer to 55%. This partially accounts for the observed 45%
particulate loading reductions after the multiclone dust collector when a 75%
reduction was seen entering the collector. What exits the collector is
primarily below 20 micrometers.
No relationship between nitric oxide emissions and flyash reinjection
was demonstrated. As seen in the table below, there was a large change in
NO measured during the E coal test series. However, this was not repeated in
the W coal test series. More data is required to draw a definite conclusion.
There is no reason to believe, at this time, that NO emissions should be affected.
NITRIC OXIDE VS REINJECTION CONFIGURATION
Full Blr Hpr No
Reinj. Reinj. Reinj.
E. Coal, ppm* 291 330 353
W. Coal, ppm 381 362 384
*Because the tests were at slightly different 02's, the NO
concentrations are corrected to 9% 02 using the relationshipi
+1%O2 = +30 ppm NO.
66 KVB 15900-528
-------
-
.« -
/\
FULL REINJECTION
EASTERN LOW FUSION COAL
TEST 9
/
NO REINJECTION
EASTERN LOW FUSION COAL
TEST 10
2 34 6 8 10 20 30 40 60 80 100 200 300 400 600 800 1000
MIDPOINT PARTICLE DIAMETER, MICROMETERS
FIGURE 5-11 Particle Size Concentrations for Boiler Outlet Particulates under Full
and Reduced Flyash Reinjection Conditions - Eastern Low Fusion Coal -
Test Site C
KVB15900-528
-------
:
I
32
3(
28
D 26
vo"
o 24
\
^ 22
g> 20
rH
> 18
2 16
O
H
14
12
10
u
H
1
1
1
1
i
FULL K
1 1
I I
WESTERN COAL
TEST 24
:-:
NO REINJECTION
WESTERN COAL
TEST 36
i I I I I II
2 34 6 8 10 20 30 40 60 80 100 200 300 400 600 800 1000
MIDPOINT PARTICLE DIAMETER, MICROMETERS
FIGURE 5-12 Particle Size Concentrations for Boiler Outlet Participates under Full
and Reduced Flyash Reinjection Conditions - Western Coal - Test Site C
KVB X5900-52B
-------
3
.
g
8
90
3
g
E-
;
OU
70
60
50
40
B 30
u 20
< 10
Pi
"
i i
EASTERN LOW FUSION COAL-Tests 9 vs 10
- - - - WESTERN COAL-Tests 24 vs 36
\
\
V
\
6 8 10 20 30 40 60 80 100
PARTICLE DIAMETER, MICROMETERS
200 300 400 600 800
FIGURE 5-13 Particulate Concentration Reduction as a Function of Particle
Diameter for the Change in Flyash Reinjection Configuration
from Full to No Reinjection - Test Site C
KVB 15900-528
-------
Flyash reinjection was not found to be responsible for a large
efficiency gain on Boiler C. In fact, as shown in Tables 5-6 and 5-7,
boiler efficiency seemed to increase in three out of the four reduced re-
injection tests.
Caution must be used in interpreting this result. The combustibles
heat loss calculation is based on the assumption that 70% of the ash collected
by the multiclone dust collector is reinjected. This is based on design
specifications. The actual percentage of flyash reinjected could not be
measured during the tests because the design of the reinjection system would
not allow it.
If the percent flyash reinjected was actually greater than 70% of
that collected, the boiler efficiency numbers would show more of an efficiency
advantage for reinjecting flyash.
The equivalent evaporation (Ib steam/lb coal) may be equally
unreliable for the short test periods used, but it is noteworthy that they
show a consistent decrease in boiler efficiency when reinjection is decreased
and stopped.
EQUIVALENT EVAPORATION
Blr Hpr
Reinjection Configuration Full Only None
E. Coal, Ib steam/lb coal 9.55 8.99 8.84
W. Coal, Ib steam/lb coal 6.19 6.10 6.03
In the course of performing the "no reinjection" tests, the flyash
collection rate was measured from each boiler hopper reinjection line, and the
flyash bulk density was determined. The collection rates are presented in the
table below. The bulk density was determined to be 16.6 lb/ft3 on the Eastern
Low Fusion coal ash.
FLYASH COLLECTION RATES BY BOILER HOPPER LINE
E «-» W
Line i 1 1 1 JL
-------
In summary, by eliminating flyash reinjection the boiler outlet
particulate loading dropped an average 74% while the multiclone outlet
particulate loading dropped an average 45%. Other emissions were not signifi-
cantly affected. At the same time, boiler efficiency results are inconclusive
because they depend upon a questionable assumption.
5.3 EXCESS OXYGEN AND GRATE HEAT RELEASE
The boiler at Test Site C was tested for emissions and efficiency
over a wide range of loads and excess air conditions. The impact of these
two parameters on emissions and efficiency are discussed in the following
paragraphs.
5.3.1 Excess Oxygen Operating Levels
Figure 5-14 shows the various boiler loads (expressed as Grate
Heat Release) and oxygen levels at which tests were run on Boiler C. Different
symbols are used for the three coals fired.
There are two significant factors evident in this figure. The
upper limit of the grate heat release on Boiler C is approximately 500,000
BTU/hr-ft2. This compares to obtainable grate heat releases for spreader
stokers of 750,000 BTU/hr-ft2. The reason for this difference is that Boiler C
was designed for future upgrading in steam capacity and, therefore, has an
oversized grate for its current rated capacity.
The second notable factor seen in Figure 5-14 is the boiler's
relatively high excess oxygen operating level. The lower limit of 7% O2 was
set by the onset of smoke and clinkering on the grate. This seemingly high
excess air limit was investigated by representatives from Babcock and Wilcox
Company which designed the boiler, and by Detroit Stoker which supplied the
stoker. Their conclusion was that the problem was caused by "chronic coal
segregation, with fines favoring the right side and burning in suspension."
The full report of their investigation is included in the appendix.
KVB 15900-528
-------
8^
LU
8-
CD
8-
x:
o
8
*
"N
s
o
-f
r
600.0
-rr r
300.0
400.0
500.0
700.0
GRRTE HEflT RELEflSE 1000 BTU/HR SOFT
O:ECOM. + : u COBL
FIG. 5-14
OXYGEN
TEST SITE C
: u com.
VS. GRRTE HERT RELEflSE
15900-528
72
-------
Another factor which may account for the high excess air limit is
the oversized grate and furnace area. One hundred percent capacity on this
boiler is equivalent to 67% capacity on a boiler designed for a 750,000
BTU/hr-ft2 grate heat release. Stoker furnaces require more excess air as the
load (or grate heat release) is reduced to maintain efficient combustion.
Figure 5-15 shows the boiler load and oxygen levels at which the
particulate loading tests were run. (Note that the previous figure,
Figure 5-14, included not only particulate loading tests but also tests
where only gaseous emissions were measured.) Here, the trend of increasing
excess air with decreasing grate heat release is evident.
5-3.2 Particulate Loading vs Excess Oxygen and Grate Heat Release
Figure 5-16 shows boiler outlet particulate loading as a function
of grate heat release. It is evident from this figure that particulate
loading (expressed in lb/106BTU) increases with increasing grate heat release.
It is also evident that coal type is not a factor whereas flyash reinjection
has a dramatic effect on particulate loading. Both of these subjects are dis-
cussed in detail in other sections of this report.
Figure 5-17 shows the particulate loading after the multiclone
dust collector. Again, the particulate loading increases with increasing
grate heat release. Again, the dramatic decrease in particulate loading due
to reduced flyash reinjection is evident. At this location on the boiler, it
appears that Western coal particulate emissions are lower than the Eastern
coal emissions, since they were not lower at the boiler outlet, the reduced
particulate loading must be due to increased collection efficiency of the
Western coal's flyash by the multiclone dust collector. (Multiclone collection
efficiency is discussed in a later section.) In the same way, it appears that
the collection efficiency of the Eastern High Fusion coal ash (H-Coal) may
have been slightly lower than for the other two coals.
These observations concerning the collection efficiency of the dif-
ferent coal's ash are only suggested by the data. They are by no means sub-
stantiated by the limited data, and should not be considered as conclusive evidence
73
KVB 15900-528
-------
8-
N
8-
8-
CD
8-
a,
LU
CD
>-
X
o
8^
00
-H-
I
300.0 350.0 400.0 450.0 500.0
GRRTE HERT RELERSE 1000 BTU/HR SOFT
; PflRT TEST
FIG. 5-15
OXYGEN
TEST SITE C
VS. GRRTE HERT RELERSE
15900-528
74
-------
8-
R
DQ
O 8-
-: 9
CD
-I 8^
cc
a:
8-
D_ °.
ZD
O
cc
O
CD
8
a
FULL FLYASH
REINJECTION
A
REDUCED FLYASH
PEINJECTION
300.0
I
350.0
100.0
450.0
500.0
GRflTE HEflT RELERSE 1000 BTU/HR SOFT
: E COOL
: u COOL
FIG. 5-16
BOILER OUT PflRT.
TEST SITE C
A : H COOL
VS. GRflTE HEflT RELEflSE
15900-528
75
-------
§-
OQ
O
CD
OC
CC
Q_
CD
FULL FLYASH
REINJECTION
if
7
REDUCED FLYASH
REINJECTION
T"
400.0
300.0
350.0
450.0
500.0
GRRTE HEflT RELEflSE 1000 BTU/HR SOFT
: E cow.
-f : u OWL
A :H COM.
FIG. 5-17
MULTICLONE OUT PRRT. VS. GRRTE HERT RELERSE
TEST SITE C
15900-528
76
-------
No tests were run to document the effect of excess air on particu-
late loadings at Test Site C.
5.3.3 Nitric Oxide vs Excess Oxygen and Grate Heat Release
Figure 5-18 presents all the measured nitric oxide emissions as a
function of grate heat release and coal type. This figure shows that the range
of nitric oxide concentration levels for Boiler C is generally 200-450 ppm.
The increase in nitric oxide concentration with increasing grate heat release
is barely evident because of the off-setting effect of decreasing excess oxygen
level with increasing grate heat release. The wide range in nitric oxide con-
centration levels is a function of, 1) the wide range of excess oxygen levels
tested, and 2) unaccounted for scatter in the data.
This figure (Figure 5-18) also suggests that coal type was not a
factor in nitric oxide concentration. The average fuel nitrogen levels in the
three coals tested at Site C were: E-Coal 1.32%, W-Coal 1.02%, and H-Coal 1.41%,
Figure 5-19 presents all the nitric oxide data as a function of
excess oxygen and three levels of grate heat release. It is plotted on an
expanded scale for later comparison with similar data from other boiler types.
Reducing the scale to fit the data, and plotting each grate heat
release range separately gives the plots shown in Figures 5-20, 5-21 and 5-22.
Those test points which were obtained in rapid succession CWO minutes between
NO readings as percent O2 is changed) to isolate unwanted variables are con-
nected by lines. They best illustrate the trend of NO vs 02.
Figure 5-23 illustrates the trends in nitric oxide emissions from
Boiler C as grate heat release and excess oxygen are changed. The absolute
magnitude of the nitric oxide emissions at a given grate heat release and
excess oxygen level may deviate significantly from these trend lines due to
other NO related variables.
5.3.4 Carbon Monoxide vs Excess Oxygen and Grate Heat Release
Figure 5-24 shows all of the carbon monoxide data obtained plotted
against grate heat release. Again, the expanded scale is used for later com-
parison with similar data from other boilers.
77 KVB 15900-528
-------
0\J
O o
LU
CJ
CC
00 |
h-
CE
o_
Q_
LU
Q
ii
X
O
CJ
II
CC
5-
r
300.0
r
400.0
500.0
600.0
700.0
GRflTE HEflT RELERSE 1000 BTU/HR SOFT
: E COM.
: u OWL
FIG. 5-18
NITRIC OXIDE
TEST SITE C
: H COHL
VS. GRRTE HERT RELERSE
15900-528
78
-------
CM
O o.
d
1 8
:z:
LU
(_>
DC
UJ
oo
\
CE
Q_
D- °-
X
O
CJ
II
cc
o
8~
A
OCD
4.00
OXYGEN
I
6.00
8.00 10.00
PER CENT
12.00
: 200-299GHR
300-399GHR
; 400-499GHR
FIG. 5-19
NITRIC OXIDE
TEST SITE C
VS. OXYGEN
15900-528
-------
CM
O
2
LU
CJ
OC
LU
CL.
CO
o_
O.
BS
I»
X
O
O
t(
cc 3-j
/
8.00
OXYGEN
9.00
r
10.00
r
a.oo
12.00
PER CENT
& I 200-299GHR
FIG. 5-20
NITRIC OXIDE
TEST SITE C
VS. OXYGEN
15900-528
80
-------
8.00
OXYGEN
9.00
10.00 11.00
PER CENT
12.00
300-399GHR
FIG. 5-21
NITRIC OXIDE
TEST SITE C
VS. OXYGEN
15900-528
81
-------
LU
(_)
QC
LU
cr
a.
UJ o-
Q 8
X
O
CJ
8
-H-
T
8.00
OXYGEN
~r
.00
10.00 11.00
PER CENT
12.00
O ; 400-499GHR
FIG. 5-22
NITRIC OXIDE
TEST SITE C
VS. OXYGEN
15900-528
82
-------
450
400
04
w
-
o
H
X
o
u
2
H
35°
300
250
100% (460 GHR)
90% (435 GHR)
80% (390 GHR)
70% (340 GHR)
60% (290 GHR)
50% (240 GHR)
9 10 11
EXCESS OXYGEN, PERCENT
12
Figure 5-23
Nitric Oxide trends vs 02 and boiler loading at
Test Site C. NO was observed to increase
an average 30 ppm for each one percent ©2 increase
at all boiler loads. The increase in NO with
boiler load was not well established and the trend
shown above is little more than an educated guess.
(GHR = Grate Heat Release, 103BTU/ft2-hr)
83
KVB 15900-528
-------
Figure 5-24 shows that firing Western coal produced significantly
greater concentrations of carbon monoxide than firing either of the Eastern
coals. At full capacity, Eastern coal CO remained below 200 ppm while Western
coal ranged from 200 to 600 ppm (with only two exceptions). It is also
apparent that carbon monoxide increases with grate heat release on this boiler.
Carbon monoxide is plotted against oxygen for both coals in
Figures 5-25 and 5-26. This time the scale has been shortened to fit the
data, and only the data points obtained in rapid succession (^20 minutes
between CO readings as percent 02 is varied) are shown. These are connected
by lines and labeled as to firing conditions.
It is clear from these plots that overfire air had an effect on
CO emissions. At any given grate heat release, the condition of maximum over-
fire air showed lower CO levels than the condition of minimum overfire air.
This is as it should be. It shows that the overfire air is doing its job of
improving combustion through induced turbulance in the flame zone.
5.3.5 Combustibles in the Ash vs Excess Oxygen and Grate Heat Release
Combustible levels in the flyash and bottom ash were very definitely
a function of coal type at Test Site C. The combustible levels are plotted
against grate heat release and coal type in Figures 5-27 and 5-28.
Western coal averaged ten percent combustibles in the boiler outlet
flyash while Eastern Low Fusion coal averaged 40% combustibles. This is a
very significant difference. There was no overlap in the two sets of data.
Bottom ash combustible levels averaged 18% while burning Western
coal and 8% while burning Eastern Low Fusion coal. They averaged only 1.3%
while burning Eastern High Fusion coal. The following table (top of page 90)
lists some of the possible contributing factors for these differences.
84 KVB 15900-528
-------
<\J
O o
LJ
CC
LJ
a_
D_
D_
X
O
O
r
400.0
T
500.0
r
600.0
r
700.0
GRRTE HEflT RELERSE 1000 BTU/HR SOFT
i: E aw.
: u COM.
FIG. 5-24
CRRBON MONOXIDE
TEST SITE C
: H COM.
VS. GRRTE HERT RELERSE
15900-528
85
-------
CNJ
O
2
UJ
O
DC
LJ
cn
i
CE
D_
GL.
LU
Q
H-4
x
O
CD
.
8
//LOW'OFA
LOW OFA
HIGH OFA
HIGH OFA
f
6.00
OXYGEN
9.00
I
10.00
I
11.00
PER CENT
I
12.00
I-MOGHR
; 340 GHR
: 260 GHR
FIG. 5-25 EASTERN LOW FUSION COAL
CRRBON MONOXIDE VS. OXYGEN
TEST SITE C
15900-528
86
-------
C\J
O o
_
cc
LU
CO §
t
a:
o_
Q_
LJ
O
ii
X
O
-
§
CC
CJ
8.00
9.00
OXYGEN
I I
10.00 11.00
PER CENT
i
12.00
: 380 GHR
! 280 GHR
I 480 GHR
FIG. 5-26 WESTERN COAL
CflRBON MONOXIDE VS. OXYGEN
TEST SITE C
87
15900-528
-------
8
LU
UJ
Q_
CD 8
O
o
cc
O
CD
o
8
f j , 1 , r
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR SOFT
O:ECOBL + : H COM. A:HO»L
FIG. 5-27
BOILER OUT COMB. VS. GRflTE HEflT RELEflSE
TEST SITE C
15900-528
88
-------
o
s"
LU
° o.
QC 8
LJ
Q_
00
O
CJ
CD
cr
o
o
CO
++
//A ,
/ / r
300.0 -WM.O 500.0 600.0 700.0
GRflTE HEni RELEflSE 1000 BTU/HR SOFT
O:ECORL + : H com A : H COM.
FIG. 5-28
BOTTOM RSH COMB. VS. GRRTE HERT RELEflSE
TEST SITE C
15900-528
89
-------
% Comb Initial Free
In Bottom Deformation Swelling
Ash "temp, °F Index
Coal Fuel Fuel
Fines Moisture Volatiles
W Coal
E Coal
H Coal
18
8
1.3
2183
1985
2145
0
7
1
48
46
44
26
5
9
29
35
31
The differences are probably accounted for by a combination of factors.
For instance, the high level of combustibles in the Western coal's bottom ash may
have resulted from poor ignition characteristics due to its high moisture and low
volatiles. The low level of bottom ash combustibles in the Eastern high fusion
coal (H Coal) may have been a function of its high ash fusion temperature and
low moisture. These arguments are only speculative. The only conclusion is that
the differences were a function of coal type.
5.3.6
Boiler Efficiency vs Excess Oxygen and Grate Heat Release
Boiler efficiency is plotted as a function of grate heat release and
coal type in Figure 5-29. The range is generally 77.5% to 85%. The data strongly
suggests that Western coal is not burned as efficiently as Eastern coal in
Boiler C.
Heat loss calculations show that one of the primary reasons boiler
efficiency is low when burning Western coal is its high moisture content. The
table below illustrates the heat loss differences between the coal types tested.
E Coal
W Coal
H Coal
AVERAGE HEAT LOSSES, PERCENT
Dry
Gas
8.22
7.95
8.57
Moisture
In Fuel
0.51
3,51
0.89
H2O From
H2 in Fuel
4.50
6.25
4.56
Total
Combustibles
3.25
1.71
1.33
Radiation &
Unmeasured
1.98
1.96
2.08
Total I
Losses
18.44
21.37
17.43
BOILER
2FFICIENCY
PERCENT
81.56
78.63
82.57
KVB 15900-528
90
-------
8-
£
0
8
CJ 8-
8-
oc
UJ
o
CD
8-
4-
+ *
r
700.0
900.0
r
-400.0
500.0
r
600.0
GRRTE HEflT RELERSE 1000 BTU/HR SOFT
0 : E COM. + : HcoflL
FIG. 5-29
BOILER EFFICIENCY
TEST SITE C
: H COM.
VS. GRRTE HERT RELERSE
15900-528
91
-------
5.4 COAL PROPERTIES
The chemical properties of the three coals fired at Site C, i.e.,
Eastern low fusion, Western and Eastern high fusion, are given in Tables
5-8, 5-9, 5-10 and 5-11. The chemical properties are also summarized in
Section 3.5. These tables show that the test coals had some very significant
differences. Three of the coal properties are computed on a constant heating
value basis in the table below to present a more meaningful comparison.
COAL PROPERTIES CORRECTED TO A CONSTANT 106BTU BASIS
Eastern Eastern
Low Fusion Western High Fusion
Moisture, lb/106BTU 4.3 30.2 7.7
Ash, Ib/lO^TU 9.1 10.6 7.8
Sulfur, Ib/lO^TU 2.36 0.82 0.74
Most of the coal related emissions and efficiency differences have
already been pointed out. Boiler outlet particulate loading (Figure 5-16) did
not vary significantly as a function of coal type. However, coal ash and coal
size consistency in the coals fired were similar. Multiclone outlet particulate
loading (Figure 5-17) was lowest for the Western coal because of increased
collection efficiency of the multiclone dust collector.
Nitric oxide emissions (Figure 5-18) were not affected by coal type.
Carbon monoxide emissions (Figure 5-24) were significantly higher when firing
Western coal than when firing either of the Eastern coals. The Western coal also
exhibited the lowest combustible fraction in the boiler outlet flyash (Figure 5-27)
and the lowest boiler efficiency (Figure 5-29).
KVB 15900-^528
92
-------
TABLE 5-8
FUEL ANALYSIS - EASTERN LOW FUSION COAL
TEST SITE C
ui
TEST NO. 8 9 10 11
PROXIMATE (As Rec)
* Moisture 6.87 5.86 6.47 6.53
% Ash 12.52 12.01 10.73 10.81
% Volatile 34.86 36. 5O 35.55 34.50
% Fixed Carbon 45.75 45.63 47.25 48.16
BTU/lb 11810 11974 12111 11992
% Sulfur 2.51 3.05 2.89 2.65
ULTIMATE (As Rec)
Moisture
Carbon
Hydrogen
Nitrogen
Chlorine
Sulfur
Ash
Oxygen (Difft
ASH FUSION (Reducing)
Initial Deformation
Soft (H-W)
Soft (H-1/2W)
Fluid
HARDGROVE GRINDABILITY INDEX
FREE SWELLING INDEX
12 13 14 15 16 19 20 46
5.99 5,88 3,48 4.63 4.38 4.89 4.18 4.54
10.43 13.75 10.95 10.19 12.23 10.27 10.54 9.66
34.81 33.77 35.86 35.53 33.69 33.92 35.79 35.49
48.77 46.60 49.71 49.65 49.70 50.92 49.49 50.31
12184 11607 12678 12539 12340 12500 12576 12831
2.70 5.00 2.74 3.00 2.44 2.25 2.85 2.57
4.54
71.46
4.79
1.04
0.07
2.57
9.66
5.87
2060
2180
2310
2430
COMP
2.36
11.32
36.15
50.17
12678
2.95
2.36
70.64
4.79
1.32
0.06
2.95
11.32
6.56
1985
2130
2265
2390
62
7
STD
AVG DEV
5.31 1.09
11.17 1.19
35.02 0.91
48.50 1.80
12262 376
2 . 89 0 . 70
KVB15900-528
-------
TABLE 5-9
FUEL ANALYSIS - WESTERN COAL
TEST SITE C
vo
TEST NO. 23 24 25 26 27 28 29 35 36 40
PROXIMATE (As Rec)
% Moisture 25.35 26.02 26.25 26.35 23.50 25.46 25.77 26.10 26.02 26.05
% Ash 9.02 8.20 8.18 9.15 8.88 12.14 9.19 9.22 8.50 8.56
% Volatile 29.36 28.28 28.11 27.97 30.09 27.82 29.08 30.81 28.69 28.95
% Fixed Carbon 36.27 37.50 37.46 36.53 37.53 34.58 35.96 33.87 36.79 36.44
BTU/lb 8480 8527 8558 8407 8877 8060 8419 8502 8388 8417
% Sulfur 0.86 0.67 0.53 0.99 0.99 0.54 0.59 0.81 0.64 0.72
ULTIMATE (As Rec)
Moisture
Carbon
Hydrogen
Nitrogen
chlorine
Sulfur
Ash
Oxygen (Diff)
ASH FUSION (Reducing)
Initial Deformation
Soft (H-W)
Soft (H-1/2W)
Fluid
HARDGROVE GRINDABILITY INDEX
FREE SWELLING INDEX
% EQUILIBRIUM MOISTURE
44
24.12
8.63
29.59
37.66
8823
0.56
24.12
51.96
3.37
1.00
0.02
0.56
8.63
10.34
2175
2240
2290
2330
45
26.57
8.59
28.59
36.25
8457
0.54
26.57
49.90
3.17
1.04
0.01
0.54
8.59
10.18
2190
2250
2325
2395
COMP
24.44
9.05
30.35
36.16
8614
0.69
24.44
50.91
3.29
0.77
0.01
0.69
9.05
10.84
2175
2260
2335
2400
49
0
24.19
AVG
25.63
9.02
28.95
36.40
8493
0.70
25.35
50.93
3.27
1.02
0.02
0.55
8.61
10.26
2183
2245
2308
2363
STD
DEV
0.93
1.05
0.90
1.18
209
0.17
KVB 15900-528
-------
TABLE 5-10
FUEL ANALYSIS - EASTERN HIGH FUSION
TEST SITE C
<£>
en
TEST NO. 41 42 43
PROXIMATE (As Rec)
% Moisture 9.72 9.38 8.17
% Ash 8.29 10.95 8.49
% Volatile 31.73 29.79 31.31
% Fixed Carbon 50.26 49.88 52.03
BTU/lb 11944 11513 12106
% Sulfur 0.74 0.93 0.96
ULTIMATE (As Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (Diff)
ASH FUSION (Reducing)
Initial Deformation
Soft (H=W)
Soft CH=1/2W)
Fluid
HARDGROVE GRINDABILITY INDEX
FREE SWELLING INDEX
COMP
13.27
7.93
31.55
47.25
11219
0.75
13.27
64.30
4.02
1.41
0.07
0.75
7.93
8.25
2145
2235
2330
2420
44
1
STD
AVG DEV
9.09 0.81
9.24 1.48
30.94 1.02
50.72 1.15
11854 307
0.88 0.12
KVB 15900-528
-------
TABLE 5-11
MINERAL ANALYSIS OF COAL ASH - TEST SITE C
10
COAL
TEST NO.
MINERAL ANALYSIS OF ASH
Silica, Si02
Alumina, A12O3
Titania,
Ferric Oxide,
Lime , CaO
Magnesia, MgO
Potassium Oxide, K2O
Sodium Oxide,
Sulfur Trioxide,
Phos. Pentoxide,
Undetermined
Silica Value
Base: Acid Ratio
T250 Temperature
% Pyritic Sulfur
% Sulfate Sulfur
% Organic Sulfur
EASTERN LOW FUSION
WESTERN
46
COMP AVG
I 44
45
COMP
EASTERN
HIGH
FUSION
AVG I ICOMP
43.76
21.64
1.03
24.83
2.45
0.90
1.65
0.60
2.81
0.21
0.12
60.83
0.46
2340
1.27
0.23
1.07
43.
21.
1.
22.
2.
3.
1.
0.
3.
0.
0.
60.
0.
62
07
10
99
30
20
85
52
01
24
10
49
47
2335
43
21
1
23
2
2
1
0
2
0
0
60
0
.69
.36
.07
.91
.38
.05
.75
.56
.91
.23
.11
.66
.47
2338
1
0
1
.27
.23
.07
43.62
16.42
0.88
4.49
16.00
3.60
0.55
0.45
12.69
0.21
1.09
64.42
0.41
2400
0.15
0.02
0.39
43.61
18.57
0.99
5.13
12.80
4.04
0.60
0.60
12.25
0.18
1.23
66.50
0.37
2450
0.04
0.01
0.49
40
18
0
7
13
3
0
0
13
0
0
62
0
.60
.56
.88
.40
.10
.84
.70
.72
.89
.18
.13
.52
.43
2375
42
17
0
5
13
3
0
0
12
0
0
64
0
.61
.85
.92
.67
.97
.83
.62
.59
.94
.19
.82
.48
.40
2408
0
0
0
.10
.015
.44
49.23
23.21
1.14
10.05
5.50
2.12
1.75
0.50
6.24
0.18
0.08
73.59
0.27
2590
KVB 15900-528
-------
5.4.1
Coal Size Consistency
As-fired coal size consistency was measured for each test involving
particulate loading or particle sizing. This parameter was not varied for
test purposes, and its natural fluctuations from test to test were small.
Figures 5-30, 5-31 and 5-32 plot the mean and standard deviation limits of the
measured coal sizing against the ABMA recommended limits of coal sizing for
spreader stokers. All three coal sizings fall generally at the upper limit
(high fines side) of the ABMA limits. A generally accepted definition of
"coal fines" is the percent by weight passing a 1/4" square mesh screen. By
this definition, all three coals had similar fines (E coal 46%, W coal 48%,
H coal 44%). Coal size consistency was not a variable in these tests.
5.4.2
Sulfur Balance
Sulfur oxides were measured during three tests, one for each of the
three coals. When the fuel analysis for these three tests were received,
however, it became apparent that test number 44 which was thought to be
Eastern high fusion coal was actually more similar to the Western coal. A
sulfur balance was made for each of these three tests and appears in Table
5-12.
Sulfur retention in the ash was measured directly. The percent-
age of sulfur retention was found to be on the order of:
Eastern low fusion coal
Western coal
Eastern high fusion coal
13% sulfur retention
18% sulfur retention
6% sulfur retention
KVB 15900-528
97
-------
Q
I
I
95
80
50
10
!0
LO
AVERAGE AND STANDARD
DEVIATION OF E-COAL
SIZE CONSISTENCY
ABMA RECOMMENDED LIMITS
OF COAL SIZING FOR
SPREADER STOKERS
50#
16# 8# 1/4" 1/2-
SIEVE SIZE DESIGNATION
L"
Figure 5-30
Size Consistency of "As Fired" Eastern Low
Fusion Coal (E-Coal) vs ABMA Recommended
Limits of Coal Sizing for Spreader Stokers
Test Site C.
KVB 15900-528
98
-------
"
80
W
i i
i I
o
8
K
W
50
30
20
10
AVERAGE AND STANDARD
DEVIATION OF W-COAL
SIZE CONSISTENCY
ABMA RECOMMENDED LIMITS
OF COAL SIZING FOR
SPREADER STOKERS
50#
16# 8# 1/4" 1/2"
SIEVE SIZE DESIGNATION
1"
Figure 5-31
Size Consistency of "As Fired" Western Coal
(W-Coal) vs ABMA Recommended Limits of Coal
Sizing for Spreader Stokers - Test Site C.
KVB 15900-528
99
-------
AVERAGE AND STANDARD
DEVIATION OF H-COAL
SIZE CONSISTENCY
ABMA RECOMMENDED LIMITS
OF COAL SIZING FOR
SPREADER STOKERS
50#
16# 8# 1/4" 1/2"
SIEVE SIZE DESIGNATION
Figure 5-32
Size Consistency of "As Fired" Eastern High
Fusion Coal (H-Coal) vs ABMA Recommended
Limits of Coal Sizing for Spreader Stokers -
Test Site C.
KVB 15900-528
100
-------
TABLE 5-12
SULFUR BALANCE
TEST SITE C
SULFUR IH FUEL
Teat
Mo.
44
45
46
Fuel
Sulfur
%
0.56
0.54
2.57
to so2
Ji/lO^BTO
1.269
'. 1.277
4.006
SULFUR IN BOTTOM ASH
Ash Sulfur
t
0.35
0.45
0.66
As SO2
Ib/lO^TO
0.038
0.048
0.061
Retention
%
3.0
3.8
1.5
SULFUR IN FLYASH
Ash Sulfur
*
0.19
0.28
0.3O
As SO2
Ib/lO^TU
0.125
0.185
0.184
Retention
%
9.9
14.5
4.6
SULFUR IN FLUE
SOx
ppn(dry)
976
810
1871
SOx as 5O2
Ib/lO^TU
1.943
1.616
3.733
GAS
Fuel Sulfur
Emitted, %
154
127
93
KVB 15900-528
-------
5.5 PARTICLE SIZE DISTRIBUTION OF FLYASH
A total of ten particle size distribution tests were run at Test
Site C. These tests were run under varying conditions of coal type and
flyash reinjection configurations. All but two of these tests were run at the
boiler outlet. Table 5-13 lists the particle size distribution tests and
methodology used.
The particle size distribution data are plotted in Figures 5-33, 5-34,
and 5-35. Each graph represents all the particle sizing data for one particle
sizing method. Description and commentary on the various methods is given in
Section 4.5.
Coal type was examined as a variable in the particle sizing tests.
All three coals had very similar particle size distribution profiles. The
small differences observed were not significant. The following table presents
the test results at three and ten micrometers.
SIZE DISTRIBUTION AND CONCENTRATION OF FLYASH
AT BOILER OUTLET AS A FUNCTION OF COAL TYPE
BAHCO CLASSIFIER SASS CYCLONES
% Below 3ym lOpm % Below 3pm
Eastern Low Fusion Coal 1.4 5.0 2.0 10.2
Eastern High Fusion Coal 1.6 4.8 1.3 6.8
Western Coal 1.2 4.7 1.0 6.1
lb/106BTU Ib/lO^TO
Below 3ym IQVta Below
Eastern Low Fusion Coal 0.36 1.25
Eastern High Fusion Coal 0.45 1.34
Western Coal 0.36 1.46
Flyash reinjection configuration was also examined as a variable.
When flyash reinjection was stopped, the particle size distribution shifted
toward the smaller particles. The particle size concentration, however, dropped
about 50% below three and ten micrometers. Table 5-14 illustrates this data.
15900-528
-------
TABLE 5-13
PARTICLE SIZE DISTRIBUTION TESTS
AND METHODOLOGY USED
TEST SITE C
Test
No.
9
10
24
36
42
44
45
46
Coal*
E
E
fr
W
H
Ht
W
E
Load
%
89
93
98
98
99
97
97
99
Flyash
Reinjection
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Particle Size Distribution
Methodology Used
Boiler Outlet Multiclone Outlet
Bahco-Sieve
Bahco-Sieve
Bahco-Sieve
Bahco-Seive Brink Impactor
Bahco-Sieve
SASS Cyclone
SASS Cyclone Brink Impactor
SASS Cyclone
E - Eastern Low Fusion Coal
W - Western Coal
H - Eastern High Fusion Coal
Test 44 had a coal analysis more nearly like Western coal than
the Eastern High Fusion coal it was presumed to be.
103
KVB 15900-528
-------
99.9
H
ca
w
I
PK
...LlJ-LLLLLll. .!
TEST
NO. COAL
FLYASH
REINJECTION
9 EASTERN LOW FUSION YES
10 EASTERN LOW FUSION NO
24 WESTERN YES
36 WESTERN NO
42 EASTERN HIGH FUSION YES
i Test No.:
24 j
36?
BAHCO CLASSIFIER
ANALYSIS
tTil..iili.!iJti.il tiliihlH -wit
itt j:i2 :ffitu. ..,..;
FIGUKE 5-33
10 30 100 300
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
Bahco Classifier and Sieve Analysis Particle Size Distribution
Test Site C
1000
KVB 15900-528
-------
99.5
99
95
I"
50
TEST
NO.
COAL
44 EASTERN HIGH FUSION COAL*
45 WESTERN COAL
46 EASTERN LOW FUSION COAL
0.1
- 1
1 3 10
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
FIGURE 5-34
Particle Size Distribution from SASS
Gravimetries - Test Site C
105
KVB15900-528
-------
TABLE 5-14
SIZE DISTRIBUTION AND CONCENTRATION OF FLYASH
AT BOILER OUTLET AS A FUNCTION OF REINJECTION CONFIGURATION
TEST SITE C
Full Reinjection
No Reinjection
Full Reinjection
No Reinjection
EASTERN LOW FUSION
WESTERN
% Below
3um
1.4
2.4
lOum
5.0
7.5
% Below 3ym
1.2
2.6
lOym
4.7
9.4
Ib/lO^TU
Below
3ym
0.36
0.14
lOym
1.25
0.45
lb/105BTU
Below
3
0.
0.
Um
36
22
lOym
1.46
0.81
Particle size distribution was also measured at the multiclone
outlet under conditions of full flyash reinjection and no flyash reinjection.
A pronounced difference was seen. The percent of flyash below three
micrometers increased from 14.7% to 46.0% when reinjection was stopped. This
data is presented in Figure 5-35.
KVB 15900-528
106
-------
NO FLYASH REINJECTION
TEST 36 WESTERN COAL
MULTICLONE OUTLET
NORMAL FLYASH REINJECTION
TEST 45 WESTERN COAL
MULTICLONE OUTLET
3 13
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
FIGURE 5-35 Particle Size Distribution from Brink Cascade
Impactor Test Site C
KVB 15900-528
107
-------
5.6 EFFICIENCY OF MULTICLONE DUST COLLECTOR
The emission control equipment of the boiler at Site C consisted
of a selective type multiclone dust collector having a design efficiency of
87%, and an electrostatic precipitator (ESP). All particulate measurements
with the exception of test number 8 were made simultaneously at the boiler
outlet and at the multiclone dust collector outlet. Therefore, multiclone
collection efficiency can be directly calculated. The collection efficiency
of the ESP was not measured. Test results are presented in Table 5-15 and
Figure 5-36.
Multiclone collector efficiency averaged 96.7 -0.6% and did not vary
with boiler load. The collection efficiency of Western coal was slightly
higher than that of either Eastern coal fired. This observation is supported
by comparing the boiler outlet particulate loading plot (Figure 5-16) with the
multiclone outlet particulate loading plot (Figure 5-17).
Flyash reinjection configuration had a major effect on collection
efficiency. When reinjection was reduced or stopped completely, the multi-
clone collection efficiency dropped by nearly four percent to an average
92.8 to.8%. This is probably due to a shift in particle size consistency of
the flyash towards smaller particles. The smaller particles are collected
less efficiently than larger ones in cyclone type collectors.
KVB 15900-528
108
-------
TABLE 5-15
EFFICIENCY OF MULTICLONE DUST COLLECTOR
TEST SITE C
Test
No.
9
10
11
12
13
14
15
16
19
20
23
24
25
26
27
28
29
35
36
40
41
42
43
Coal*
Type
E
E
E
E
E
E
E
E
E
E
W
W
W
W
W
W
W
W
W
W
H
H
H
Load
%
89
93
93
93
91
93
91
93
92
55
100
98
78
99
100
99
100
55
98
102
58
99
78
°2
%
8.9
9.1
9.1
8.9
8.9
9.2
9.1
8.7
8.7
11.0
8.6
8.7
8.6
9.9
8.9
9.0
8.4
10.6
8.1
8.3
11.3
9.4
9.8
Flyash
Rein j .
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
PART LOADING LB/105BTU
Coll Inlet
25.0
6.0
7.0
19.0
21.1
20.9
22.6
23.9
25.1
13.2
29.2
31.1
20.4
34.0
31.6
33.1
36.4
15.2
8.6
6.1
16.2
28.0
20.3
Coll Outlet
0.82
0.48
0.50
0.69
0.64
0.94
0.78
0.84
0.88
0.51
1.04
1.03
0.55
1.04
1.03
0.94
0.74
0.36
0.52
0.47
0.54
1.07
0.69
COLLECTOR
EFFICIENCY, %
96.7
92.0
92.9
96.4
97.0
95.5
96.5
96.5
96.5
96.2
96.4
96.7
97.3
96.9
96.7
97.2
98.0
97.7
93.9
92.4
96.7
96.2
96.6
Average* 96 . 7
±0.6
* E - Eastern Low Fusion Coal
W - Western Coal
H - Eastern High Fusion Coal
* - Average does not inlcude the reduced reinjection
tests 10, 11, 36 and 40
KVB 15900-528
109
-------
8-
ffi
. 9-
u_
LU
LU
0 a_i
_i »H
o 8
»i
H-
_i
8-
FULL FLYASH REINJECTION
-H-
REDUCED FLYASH
REINJECTION
300.0
350.0
r
400.0
T
450.0
500.0
GRRTE HEflT RELEflSE 1000 BTU/HR SOFT
Q: E cow. -f- ;u COM.
FIG. 5-36
MULTICLONE EFF.
TEST SITE C
: H OWL
VS. GRflTE HEflT RELEflSE
15900-528
110
-------
5.7 MODIFIED SMOKE SPOT NUMBER
Smoke Spot readings were taken with a Bacharach Smoke Spot Tester
at the multiclone outlet. The pump was stroked once, twice or three tiroes
each sample instead of the specified ten times required on an oil-fired unit
by ASTM D2156-65. Test results are presented in Table 5-16 and are plotted
against particulate loading and combustible loading in Figures 5-37 and 5-38.
The purpose of this exercise was to develop a quick and easy
method of estimating either particulate loading or combustible loading from
stoker-fired boilers. It is observed in Figures 5-37 and 5-38 that no
correlation could be made.
Based on this data, the modified smoke spot technique is not a
useful method for estimating particulate or combustible loadings at the
multiclone outlet of spreader stokers.
5.8 SOURCE ASSESSMENT SAMPLING SYSTEM
Three SASS tests were run at Test Site C. The plan was to run one
test on each of the three test coals. However, fuel analyses showed that
what had been thought to be Eastern High Fusion coal (Test 44) was actually
Western coal.
The table below shows the conditions under which the tests were
run. Boiler load, excess oxygen and overfire air were similar for each test.
SASS TESTS RUN AT SITE C
Test
No.
44
45
46
Sample
Location
Boiler Outlet
Boiler Outlet
Boiler Outlet
Coal
Type
H*
W
E
Load
%
97
97
99
°2
%
8.9
8.3
9.0
OFA
"H?0
24
24
23
Contractor
For Analysis
Battelle
Battelle
Battelle
E - Eastern Low Fusion Coal
W - Western Coal
H - Eastern High Fusion Coal
Test 44 is believed to be Western coal based on fuel analysis
111 15900-528
-------
TABLE 5-16
MODIFIED SMOKE SPOT DATA
TEST SITE C
Test
No.
23
24
25
26
27
28
29
35
36
40
41
42
43
Avg Reading
1 Pump
2
2
2.5
2
3
2
2
0.75
2
1.5
2.25
2
2
Avg Reading
2 Pumps
3
3
3
3
5
3
3
1.5
3
2.75
3.25
3
4
Avg Reading
3 Pumps
4
4
4
4
6
3.5
4
1.75
4
3.25
4
4.25
5
Particulate
Loading
lb/106BTU
1.038
1.025
0.545
1.038
1.028
0.938
0.738
0.356
0.519
0.466
0.538
1.072
0.685
Combustible
Loading
lb/106BTU
0.078
0.064
0.046
0.065
0.075
0.059
0.027
0.071
0.058
0.144
0.195
0.164
112
KVB 15900-528
-------
8-1
d
8-
to
CC
8-
o
tn 8.-
LU
O
CD
8-
(SI
+ A
A
A+^ + +
CSDO
i i I I i
.200 .400 .600 .800 1.000
MULTICLONE OUT PflRT. LB/MILLION BTU
O: i PUMP -I-SZPUMPS A: 3
FIG. 5-37
SMOKE SPOT NUMBER VS. MULTICLONE OUT PflRT,
TEST SITE C
15900-528
113
-------
8-
o
8-
CC
LU
CD
O
°-
CO
LU
±£
O
8-
CM
A
A A AA& A 4-
O
1 1 1 1 r
.0400 .0800 .1200 .1600 .2000
MULTICLONE OUT COMB. LB/MILLION BTU
+ : 2 PUHPS A:
FIG. 5-38
SMOKE SPOT NUMBER VS. MULTICLONE OUT COMB,
TEST SITE C
15900-528
114
-------
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 con-
tent. In addition, seven specific polynuclear aromatic hydrocarbons (PAH)
will be sought. These are given in Table 5-17.
TABLE 5-17
POLYNUCLEAR AROMATIC HYDROCARBONS
ANALYZED IN SITE C SASS SAMPLES
Element Name
7,12 Dimethylbenz (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
Molecular
Weight
256
278
228
268
252
302
302
267
Molecular
Formula
C20»16
C22H14
C18H12
C21H16
C20H12
C24H14
C24H14
C20H13N
5.9
DATA TABLES
Tables 5-18 through 5-22 summarize the test data obtained at
Test Site C. These tables, in conjunction with Table 2-1 in the Executive
Summary, are included for reference purposes.
KVB 15900-528
115
-------
TABLE 5-18
PARTICULATE EMISSIONS
TEST SITE C
u
g
o
a
a
s
0)
Test
No.
8
9
10
11
12
13
14
15
16
19
20
23
24
25
26
27
28
29
35
36
40
41
42
43
Coal*
E
E
E
E
E
E
E
E
E
E
E
W
w
W
N
W
w
w
w
N
H
H
H
H
Load
%
69
89
93
93
93
91
93
91
93
92
55
100
98
78
99
100
99
100
55
96
102
58
99
78
02
%
10.2
8.9
9.1
9.1
8.9
8.9
9.2
9.1
8.7
8.7
11.0
8.6
8.7
8.6
9.9
8.9
9.0
8.4
10.6
8.1
8.3
11.3
9.4
9.8
EMISSIONS
lb/10bBTO
13.09
25.00
6.02
7.00
19.02
21.11
20.88
22.63
23.86
25.14
13.23
29.22
31.14
20.39
33.99
31.59
33.09
36.42
15.16
8.57
6.15
16.19
28.00
20.29
gr/SCF
4.79
10.25
2.43
2.82
7.80
8.66
8.35
9.12
9.94
10.48
4.48
12.28
12.98
8.57
12.78
12.95
13.46
15.55
5.34
3.75
2. 65
5.32
11.00
7.70
Ib/hr
1940
5116
1401
1586
4239
4348
4640
4956
5130
5410
1867
7392
7699
4140
8423
7477
8364
9280
2283
2126
1583
2243
6447
3684
Velocity
ft/sec
36.87
37.49
38.31
39.19
39.57
36.17
39.81
36.18
40.20
39.71
29.78
47.58
46.92
34.88
47.23
45.81
47.29
47.93
28.58
45.84
47.82
32.69
47.01
35.91
u
E
I
at
H
9
a
8
j
0
w
2
y
*
9
10
11
12
13
14
15
16
19
20
23
24
25
26
27
28
29
35
36
40
41
42
43
E
E
E
E
E
E
E
E
E
E
W
W
W
H
W
H
W
W
H
H
H
H
H
89
93
93
93
91
93
91
93
92
55
100
98
78
99
100
99
100
55
98
102
58
99
78
8.9
9.1
9.1
8.9
8.9
9.2
9.1
8.7
8.7
11.0
8.6
8.7
8.6
9.9
8.9
9.0
8.4
10.6
8.1
8.3
11.3
9.4
9.8
0.815
0.481
0.496
0.690
0.637
0.936
0.784
0.842
0.878
0.509
1.038
1.025
0.545
1.038
1.028
0.938
0.738
0.356
0.519
0.466
0.538
1.072
0.685
0.334
0.194
0.200
0.302
0.285
0.381
0.327
0.359
0.369
0.178
0.440
0.434
0.231
0.404
0.428
0.378
0.310
0.123
0.229
0.199
0.175
0.418
0.262
167
112
112
154
131
208
172
181
189
72
263
253
111
257
243
237
188
54
129
120
75
247
124
37.40
37.90
39.30
38.74
36.15
40.57
39.26
38.95
38.06
30.85
45.11
46.40
35.86
44.39
45.65
48.12
45.97
32.76
45.77
45.80
31.56
45.30
34.53
* E - Eastern Low Fusion Coal
W - Western Coal
H - Eastern High Fusion Coal
KVB 15900-528
116
-------
TABLE 5-19
HEAT LOSSES AND EFFICIENCIES
TEST SITE C
'2!
H
D
tn
s
§
EH
CO
.
EH
E
8
9
10
11
12
13
14
15
16
19
20
w
Q
h5
CO
0
S
Q
9.02
7.56
7.92
8.12
8.02
8.28
7.89
7.98
7.71
8.08
9.84
W
5 H
CO CM
H
i3
0.67
0.56
0.62
0.63
0.57
0.59
0.32
0.43
0.41
0.46
0.38
g; jj^
8*
Q
51
H2O FRO:
BUSTION
4.64
4.59
4.53
4.56
4.50
4.72
4.33
4.38
4.42
4.41
4.38
K
55 rtj
H Q
9 °
OQ ty
H T
COMBUST
MECH COI
0.91
3.43
2.32
3.86
2.40
5.14
2.01
1.80
2.32
2.55
1.20
U)
CO 03
H CO
COMBUST
IN FLYA
0.24
0.21
0.15
0.19
0.17
0.25
0.27
0.23
0.22
0.23
0.24
Z
H
W
a*
H ri!
COMBUST
BOTTOM
0.23
0.05
0.15
0.10
1.29
1.62
0.13
0.09
0.37
1.38
0.05
CO
pq
Tf\
B
H W
S W
gS
1.38
3.69
2.62
4.15
3.86
7.01
2.41
2.12
2.91
4.16
1.49
-B
§
fa
&
O
RADIATI
BOILER
0.63
0.44
0.42
0.42
0.42
0.44
0.42
0.44
0.42
0.42
0.78
Q
M
E
UNMEASU
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
CO
W
CO
W
O
TOTAL L
17.66
18.34
17.61
19.38
18.87
22.54
16.87
16.85
17.37
19.03
18.37
;
r)
gi
EFFICIE
82.34
81.66
82.39
80.62
81.13
77.46
83.13
83.15
82.63
80.97
81.63
3
8
o
Ed
H
CO
23
24
25
26
27
28
29
35
36
40
8.01
7.90
7.24
8.74
8.07
7.83
7.54
9.25
7.39
7.54
3.47
3.52
3.51
3.64
3.06
3.64
3.52
3.55
3.57
3.57
6.29
6.16
6.10
6.28
6.02
6.49
6.25
6.31
6.27
6.29
0.97
0.50
0.25
0.62
0.56
0.62
0.50
0.21
1.26
1.45
0.11
0.10
0.07
0.09
0.12
0.09
0.04
0.04
0.11
0.09
1.55
1.44
0.26
0.45
2.45
2.04
0.49
0.40
0.20
0.02
2.63
2.04
0.58
1.16
3.13
2.75
1.03
0.65
1.57
1.56
0.40
0.40
0.58
0.40
0.40
0.40
0.40
0.78
0.40
0.40
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
22.30
21.52
19.51
21.72
22.18
22.61
20.24
22.04
20.70
20.86
77.70
78.48
80.49
78.28
77.82
77.39
79.76
77.96
79.30
79.14
K SB O
H O H
P H CO
rn 5C Q
3 ffi g
w
41
42
43
9.80
7.62
8.28
0.95
0.94
0.79
4.54
4.63
4.50
0.75
1.32
1.04
0.21
0.30
0.24
0.01
0.13
0.00
0.97
1.75
1.28
0.75
0.40
0.58
1.5
1.5
1.5
18.51
16.84
16.93
81.49
83.16
83.07
KVB 15900-528
117
-------
TABLE 5-20
PERCENT COMBUSTIBLES IN REFUSE
TEST SITE C
2
8
§
H
en
g
Q
§
H
3
Test
No.
8
9
10
11
12
13
14
15
16
19
20
46
AVERAGE
Boiler
Hopper
48.3
__
__
48.3
Boiler
Outlet
24.2
57.2
47.8
30.8
24.4
46.0
55.9
41.6
30.2
39.8
Mechanical
Collector
Hopper
16.9
32.6
21.6
40.9
30.2
57.7
23.2
19.0
23.2
24.1
21.7
14.1
27.1
Mechanical
Collector
Outlet
_~
17.4
23.6
28.9
16.5
25.3
19.8
19.8
16.9
17.4
31.5
21.7
Bottom
Ash
3.0
0.7
2.3
1.6
21.2
19.2
2.1
1.5
5.3
23.6
9.1
1.5
7.6
s
8
K
EH
£
23
24
25
26
27
28
29
35
36
40
45
AVERAGE
8.7
__ --
9.2
12 . 1
11.7
7.1
8.4
4.0
48.9
26.6
48.9 11.0
7.9
3.8
2.9
4.3
4.2
4.4
3.2
3.3
9.3
17.6
4.2
5.9
7.5
6.2
8.5
6.3
7.3
6.3
3.6
13.7
12.4
8.0
20.4
21.1
37.5
5.8
34.4
19.0
6.3
51.4
2.8
0.3
0.2
18.1
§3
H O
35 cj
13 m
3*
41
42
43
44*
AVERAGE
17.2
16.2
__
16.7
11.1
11.3
12.2
6.9
11.5
26.7
18.2
24.0
23.0
1.1
1.9
0.8
2.5
1.3
* Fuel analysis indicate that Test 44 was Western Coal and not
Eastern High Fusion coal as thought. It is not included in
the Eastern High Fusion Coal average.
118
KVB 15900-528
-------
TABLE 5-21
AS FIRED COAL SIZE CONSISTENCY
TEST SITE C
S!
8
S
H
D
PM
8
M
13
53
w
Test
Number
8
9
10
11
12
13
14
15
16
19
20
46
* 47 f #1
47 f #2
47 f#3
47 f#4
47 f#5
47 f#6
47 f#7
47 AVG
^Composite
AVERAGE
1"
86
90
88
88
89
91
91
91
90
88
92
88
96
92
94
90
93
91
91
92
92
90
PERCENT PASSING
1/2"
62
74
66
71
66
71
70
67
70
63
72
66
78
76
76
45
74
77
65
70
71
68
STATED
1/4"
37
52
43
50
42
46
47
47
49
43
50
45
53
55
51
18
50
61
40
47
47
46
SCREEN SIZE
#8
10
27
18
22
16
19
25
25
27
23
28
25
29
33
27
7
22
34
21
25
21
22
#16
5
13
8
9
6
7
12
13
14
13
14
16
18
19
14
4
12
18
11
14
10
11
jjj
g
^
H
H
W
23
24
25
26
27
28
29
35
36
40
45
Composite
AVERAGE
91
93
94
94
93
96
92
90
95
93
93
93
93
67
67
68
75
66
81
71
68
72
71
71
70
71
48
42
44
52
42
59
49
45
49
46
49
47
48
30
24
26
28
21
34
29
24
26
25
27
26
27
15
15
18
16
11
20
18
14
14
16
15
16
16
8
H
PH CL*
w
w 0
< M
W 8
41
42
43
44
Composite
AVERAGE
85
78
84
91
86
85
65
54
62
70
66
63
47
40
43
46
47
44
26
26
26
26
26
26
12
18
16
16
14
16
* During Test 47, coal samples were taken individually from each coal
feeder. Only the average of the seven feeders is averaged with the
other tests.
t The composite sample includes a coal sample from each test on a
given coal. It is not included in the coal's average size consistency.
119 KVB 15900-528
-------
TABLE 5~22
STEAM FLOWS & HEAT RELEASE RATES
TEST SITE C
Front Foot Grate Heat Furnace Heat
Test
No.
1*
5*
6*
7*
8
9
10
11
12
13
14
15
16
17
18
19
20
21*
22*
23
24
25
26
27 .
28
29
3O*
31*
32*
33*
34*
35
36
40
41
42
43
44
45
46
48*
49*
50*
Capacity
98.6
96.9
91.8
92.5
69.0
89.5
93.0
93.0
93.0
90.8
93.0
91.3
92.7
76.0
76.0
92.1
55.3
76.7
76.7
99.6
98.4
78.2
99.2
100.3
99.1
99.8
58.5
55.2
95.7
96.3
95.0
54.9
97.7
102.2
57.6
98.9
77.9
97.1
97.4
99.0
92.5
58.0
58.0
Steam Flow
103lb/hr
179.9
176.8
167.5
168.8
125.9
163.3
169.7
169.7
169.8
165.6
169.7
166.5
169.2
138.7
138.7
168.0
100.9
140.0
140.0
181.7
179.5
142.7
181.0
183.0
180.9
182.0
106.8
100.7
174.6
175.8
173.3
100.1
178.4
186.4
105.2
180.4
142.3
177.2
177.7
180.7
168.8
105.9
105.9
* An average BTU/lb was
Beat Input
lO^TU/hr
252.7
235.1
221.3
225.3
148.2
204.7
232.5
226.5
222.9
206.0
222.2
219.0
215.0
176.6
176.6
215.2
141.1
197.9
197.9
252.9
247.2
203.0
247.8
236.7
252,8
254.8
148.9
142.0
244.3
245.7
239.7
150.5
248.2
257.4
138.5
230.3
181.6
244.4
241.2
230.2
210.2
135.2
135.2
used, for
for
Heat Release
104BTU/ft/hr 10
931.5
866.7
815.9
830.6
546.4
754.7
857.1
835.0
821.8
759.4
819.2
807.4
792.6
651.1
651.1
793.3
520.2
729.6
729.6
932.4
911.3
748.4
913.5
872.6
932.0
939.4
548.9
523.5
900.6
905.8
883.7
554.8
915.0
949.9
510.6
849.0
669.5
901.0
889.2
848.7
775.0
498.3
498.3
tests 1-7, 17-18,
Release
490.2
456.2
429.4
437.1
287.5
397.2
451.1
439.5
432.5
399.7
431.1
424.9
417.2
342.6
342.6
417.5
273.8
384.0
384.0
490.7
479.6
393.9
480.8
459.3
490.5
494.4
288.9
275.5
474.0
476.7
465.1
292.0
481.6
499.4
268.7
446.8
352.3
474.2
468.0
446.6
407.9
262.2
262.2
48-50 -
tests 21, 22, 30-34
Release
/hr 102BTU/ft3/hr
208.8
194.3
182.9
186.2
122.5
169.2
192.1
187.2
184.2
170.2
183.6
181.0
177.7
146.0
146.0
177.9
116.6
163.6
163.6
209.0
204.3
167.7
204.8
195.6
208.9
210.6
123.1
117.4
201.9
203.1
198.1
124.4
205.1
212.7
114.5
190.3
150.1
202.0
199.3
190.2
173.7
111.7
111.7
12,262
8,493
KVB 15900-528
120
-------
APPENDICES
Page
APPENDIX A - EXCESS AIR INVESTIGATION 122
APPENDIX B - ENGLISH AND METRIC UNITS TO SI UNITS . . . 126
APPENDIX C - SI UNITS TO ENGLISH AND METRIC UNITS . . . 127
APPENDIX D - SI PREFIXES 128
APPENDIX E - EMISSIONS UNITS CONVERSION FACTORS ... 129
121
-------
APPENDIX A
THE BABCOCK & WILCOX COMPANY
POWER GENERATION GROUP
T° P. E. RALSTON - MANAGER FIELD ENGINEERING 21K
S. E. KNIGHT - DESIGN SERVICE COORDINATOR 21K
BDS 66>-6
Oust.
File No.
or Ref. '
5-10266
Subj.
Date
EXCESS AIR
JULY 7, 1978
This Ittter to cover one customer «nd one subject only.
Visited this job June 26, 27 and 28, 1978 with A. J. Kraus of
Detroit Stoker to either reduce excess air to design, or, to find
the reason why excess air was being carried high.
KVB, Incorporated, is running a series of tests on this boiler
as part of EPA testing of stoker units.
This 28 foot wide SPB was designed to generate 182.5 M pph of 875
psig 900°F steam with 370°F feedwater firing Montana high fusion
temperature sub-bituminous coal of 84l6 BTU/lb. Performance was
also checked for 275 M pph, (300 M 2 hour peak), firing eastern
bituminous of 12,000 BTU/lb. Note that the eastern bituminous is
the normal coal and was being burned during our visit. Load is
restricted to 182.5 M pph in order to stay below 249 MKB input.
Even though a variance was available for testing, (the owner)
would not operate above this EPA limit.
Customer's Lear Siegler single point oxygen analyzer, located at
the dust collector outlet, was out of service. The instrument
operates on a wet flue gas basis, which means it reads about 0.4
percent oxygen~~Iower than the dry basis Orsat for this fuel.
On Monday June 26,, 1978 at a load of 155 M pph and indicated air
flow of 175, Orsats at the KVB test truck? reading the boiler outlet
taps, showed 7.6 percent oxygen at the boiler left side, 9-5 percent
oxygen :just left of center, 10.4 percent oxygen on the right side,
and, 8.4 percent oxygen composite. KVB readings were 8.35 percent
left, 9.8 percent off center, 11.2 percent right, and, 9 percent
composite.
On Tuesday June 27, 1978 at 165 M pph and indicated air flow of
185 M, oxygen by Orsat at the boiler outlet test tap elevation was
8 percent left, 9 percent off center, and, 10.4 percent right.
"Committed to Excellence"
122
KVB 15900-528
-------
P. E. RALSTON
S-10266 - EXCESS AIR -2- JULY 7, 1978
The penthouse seal air fan was shut off.
Orsat read 7-^- percent left, 9-2 percent off center, 10.6
percent right.
Boiler hopper re-injection air was reduced to 9 inches w'.g. from
12 inches w.g.; coal feed was increased to the right side, and,
the air flow was decreased to a spread of 10 M, that is, 165 M
steam flow, 175 air flow.
Oxygen by Orsat was 6.3 percent left, 7.8 percent off center,
8.0 percent right. With mild clinkering starting on the left of
the stoker, the air flow spread was returned to 20 M overnight.
Wednesday June 28, 1978 at a similar firing rate and 10 M air flow
spread, the left No. 1 and No. 3 dust re-injection lines from the
dust collector were shut off.
Oxygen by Orsat was 5-8 percent left, 8 percent off center,
9 percent right.
Coal feed was increased on three right side feeders.
Oxygen was 6.6 percent left, 8.6 percent off center, 9 percent
right. Mild clinkering was again starting on the left side.
Conclusions;
1. The right side of the unit has a constant 3 percent higher
oxygen than the left side. The furnace shows a much heavier
fuel and ash bed on the left side, tapering off to nothing on
the right side. There is heavy, left side dust reinjection
from the dust collector.
Combined, this is strong evidence of chronic coal segregation,,
with fines favoring the right side and burning in suspension.
2. Orsat readings were about 0.5 percent oxygen less than KVB's
Teledyne oxygen analyzer readings.
3. Customer's wet basis oxygen analyzer can be expected to read
about O.Jj- percent oxygen lower than the dry basis Orsat or
Teledyne on this fuel.
12 "^
KVB 15900-528
-------
P. E. RALSTON
S-10266 - EXCESS AIR -3- JULY ?, 19?8
Recommendations:
1. Any further effort to balance the excess air across the unit
should start by achieving a balanced, non-segregated coal feed
to the coal hopper. Note that a conveyor belt feeds coal to
the center of this vride hopper. A number of stationary or
moveable devices are available to reduce hopper segration.
2. Leave the penthouse seal air fan shut off, unless future
inspections show that dust is collecting in the penthouse.
3. Correct the temperature recorder problem that put the flue gas
and air temperature thermocouples out of service.
S. E. Knight
SEKtcw
124 RVB 15900-528
-------
BDS 120-1
THE BABCOCK & WILCOX COMPANY
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CUSTOMER
JOB NO. 5-7^266
SUBJECT
BY
6/-U,l7,
DATE
125
KVB 15900^528
-------
APPENDIX B
CONVERSION FACTORS
ENGLISH AND METRIC UNITS TO SI UNITS
To Convert From
To
Multiply By
in
in
ft
ft
cm
m
m-
2.540
6.452
0.3048
0.09290
0.02832
lb
Ib/hr
lb/106BTU
9/Mcal
BTU
BTU/lb
BTU/hr
J/sec
BTU/ft/hr
BTU/ft/hr
BTU/ft2/hr
BTU/ft2/hr
BTU/ft3/hr
BTU/ft3/hr
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
0.4536
0.1260
430
239
1054
0.002324
0.2929
1.000
3600
0.9609
3459
3.152
11349
10.34
37234
psia
"H20
Rankine
Fahrenheit
Celsius
Rankine
COAL FUEL ONLY
ppm @ 3% 02 (S02)
ppa @ 3% 02 (S03)
ppm @ 3% O2 (NO)
ppm @ 3% O2 (NO2)
ppm @ 3% O2 (CO)
ppm ? 3% O2 (CH4)
Pa
Pa
Celsius
Celsius
Kelvin
Kelvin
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
6895
249.1
C
C
K
K
5/9 R-2 73
5/9(F-32)
C+273
5/9 R
0.851
1.063
0.399
0.611
0.372
0.213
KVB 15900-528
126
-------
APPENDIX C
CONVERSION FACTORS
SI UNITS TO ENGLISH AND METRIC UNITS
To Convert From
cm
m
m'4
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
COAL FUEL ONLY
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
To
in
in2
ft
ft2
ft3
Ib
Ib/hr
g/Mcal
BTU
BTU/lb
BTU/ft/hr
BTU/ft2/hr
BTU/ft3/hr
BTU/hr
J/hr
BTO/ft/hr
BTO/ft2/hr
BTU/ft3/hr
psia
"H20
Fahrenheit
Fahrenheit
Rankine
Rankine
ppm @ 3% O2 (SO2)
ppm @ 3% O2 (SO3)
ppm 9 3% O2 (NO)
ppm @ 3% 02 (N02)
ppm @ 3% O2 (CO)
ppm @ 3% 02 (CH4)
Multiply By
0.3937
0.1550
3.281
10.764
35.315
2.205
7.937
0.00233
0.00418
0.OOO948
4.303
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
1.18
0.941
2.51
1.64
2.69
4.69
KVB 15900-528
127
-------
APPENDIX D
SI PREFIXES
Multiplication
Factor Prefix SI Symbol
1012 tera T
109 giga G
10^ mega M
103 kilo k
102 hecto* h
101 deka* da
10"1 deci* d
10"2 centi* c
10~3 ndlli m
10~*> micro y
10~9 nano n
10~12 pico p
10~15 femto f
10~18 atto a
*Not recommended but occasionally used
KVB 15900-528
128
-------
APPENDIX E
EMISSION UNITS CONVERSION FACTORS
FOR TYPICAL COAL FUEL (HV = 13,320 BTU/LB)
Multiply
To ^\ By
Obtain
% Weight
In Fuel
% Weight in Fuel
S N
lbs/106Btu
S02
N02
0.666
A
0.405
grams/106Cal
SO2 NO2
0.370
0.225
PPM
(Dry @ 3% 02)
SOx NOx
13.2x10
-4
5.76xlO~4
Grains/SCF.
(Dry @12% C02)
S02 N02
1.48
.903
lbs/106Btu
SO-
NO-,
1.50
(.556)
19.8x10
,-4
(2.23)
2.47
(.556)
14.2x10
-4
(2.23)
SO-
grams/106Cal
NO-
SOx
PPM _
(Dry @ 3% 02)
NOx
2.70
(1.8)
4.44
758
505
A
1736
/
'
35.6xlO~4
(4.01)
(1.8)
25.6x10"
(4.01)
281
704
1127
391
1566
SO,
Grains/SCF
(Dry@12% C02)
NO-
.676
(.448)
(.249)
8.87x10
-4
1.11
(.448)
(.249)
6.39xlO~4
NOTE: 1. Values in parenthesis can be used for all flue gas constituents such as oxides of carbon
oxides of nitrogen, oxides of sulfur, hydrocarbons, particulates, etc.
2. Standard reference temperature of 530°R was used.
KVB 15900-528
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-79-130a
3. RECIPIENT'S ACCESSION NO.
I. TITLE AND SUBTITLE
Field Tests of Industrial Stoker Coal-fired Boilers
for Emissions Control and Efficiency Improvement-
Site C
5. REPORT DATE
May 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
B. PERFORMING ORGANIZATION REPORT NO
J.E.Gabrielson, P.L.Langsjoen, and T.C.Kosvic
9. PERFORMING ORGANIZATION NAME AND ADDRESS
KVB, Inc.
6176 Olson Memorial Highway
Minneapolis, Minnesota 55422
10. PROGRAM ELEMENT NO.
EHE624
. CONTRACT/GRANT NO.
E PA-TAG-D7-E 681 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; 4/78 - 7/78
14. SPONSORING AGENCY CODE
EPA/600/13
SUPPLEMENTARY NOTES rERL_RTPproject officer te R>E>HalL (*)Cosponsors are DoE
(W.T.Harvey, Jr.) and the American Boiler Manufacturers Assoc. EPA-600/7-78-
136a and -79-041a are similar Site A and B reports.
The report gives results of field measurements made on a 182,500 Ib/hr
spreader stoker boiler. The effect of various parameters on boiler emissions and
efficiency was studied. Parameters included overfire air, flyash reinjection, excess
air, boiler load, and fuel properties. Measurements included gaseous and particulate
emissions, particle size distribution of the flyash, and combustible content of the
ash. Gaseous emissions measured were O2, CO2, CO, NO, SO2, and SO3 in the flue
gas. Sample locations included the boiler, multiclone, and electrostatic precipitator
outlets. In addition to test results and observations, the report describes the facility
tested, coals fired, test equipment, and procedures. Stopping flyash reinjection
reduced particulate loading at the boiler outlet by 75%, and reduced particulate loa-
ding at the multiclone outlet by 45%. Increasing the overfire air from 5 to 25 in. H2O
resulted in a 9% increase in NO emissions. At design capacity, the boiler emitted
between 27. 5 and 35.5 Ib/million Btu particulate matter and between 340 and 410 ppm
NO at the boiler outlet.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Boilers
ombustion
oal
ield Tests
Dust
Itokers
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Improvement
Efficiency
Flue Gases
Fly Ash
Particle Size
Nitrogen Oxides
Sulfur Oxides
Air Pollution Control
Stationary Sources
Combustion Modification
Spreader Stokers
Particulate
Overfire Air
Flyash Reinjection
I3E"
13A
21B
21D
14B
11G
07B
DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
138
20. SECURITY CLASS (Thispage/
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
130
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