ABMA
American
Boiler Manufacturers
Association
1500 Wilson Boulevard
Arlington VA 22209
DoE
United States
Department
of Energy
Division of Power Systems
Energy Technology Branch
Washington DC 20545
EPA
U S Environmental Protection Agency
Office of Research and Development
Industrial Environmental Research
Laboratory
Research Triangle Park NC 2771 1
EPA-600/7-80-065a
MaVch 1980
Field Tests of Industrial
Stoker Coal-fired Boilers
for Emissions Control
and Efficiency
Improvement - Site F
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 m this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of, and development of, control technologies for energy
systems; and integrated assessments of a wide'range of energy-related environ-
mental issues.
EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
for publication. Approval does not signify that the contents necessarily reflect
the views and policies of the Government, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-80-065a
March 1980
Field Tests of Industrial Stoker
Coal-fired Boilers for Emissions
Control and Efficiency Improvement - Site F
by
P.L Langsjoen, R.J. Tidona, and J.E. Gabrielson
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 Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
U.S. DEPARTMENT OF ENERGY
Division of Power Systems/Energy Technology Branch
Washington, DC 20545
and
AMERICAN BOILER MANUFACTURERS ASSOCIATION
1500 Wilson Boulevard
Arlington, VA 22209
-------
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 (DOE) and R. E. (Bob) Hall of the
United States Environmental Protection Agency (EPA). Thanks are due to
their agencies, DOE and EPA, for co-funding the program.
We would also like to thank the American Boiler Manufacturers
Association, ABMA Executive Director, W. H. (Bill) Axtman, ABMA Assistant
Executive Director, R. N. (Russ) Mosher, ABMA's Project Manager, B. C. (Ben)
Severs, and the members of the ABMA Stoker Technical Committee chaired
by W. B. (Willard) McBurney of the McBurney Corporation for providing
support through their time and travel to manage and review the program. The
participating committee members listed alphabetically are as follows:
R. D. Bessette Island Creek Coal Company
T. Davis Combustion Engineering
N. H. Johnson Detroit Stoker
K. Luuri Riley Stoker
D. McCoy E. Keeler Company
J. Mullan National Coal Association
E. A. Nelson Zurn Industries
E. Poitras The McBurney Corporation
P. E. Ralston Babcock and Wilcox
D. C. Reschley Detroit Stoker
R. A. Santos Zurn Industries
We would also like to recognize the KVB engineers and technicians who
spent much time in the field, often under adverse conditions, testing the
boilers and gathering data for this program. Those involved at Site F were
Hans Buening, Hans Stix, Mike Gabriel, Jon Cook, and Russ Parker.
Finally, our gratitude goes to the host boiler facilities which in-
vited us to test their boilers. At their request, all participating facilities
will remain anonymous to protect their own interests. Without their cooperation
and assistance this program would not have been possible.
11
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TABLE OF CONTENTS
Section Page
ACKNOWLEDGEMENTS ii
LIST OF TABLES V
LIST OF FIGURES vi
1.0 INTRODUCTION 1
2.0 EXECUTIVE SUMMARY 3
3.0 DESCRIPTION OF FACILITY TESTED AND COALS FIRED
3.1 Boiler F Description 9
3.2 Over fire Air System 9
3.3 Flyash Reinjection 9
3.4 Test Port Locations 13
3.5 Particulate Collection Equipment 13
3.6 Coals Utilized 13
4.0 TEST EQUIPMENT AND PROCEDURES 17
4.1 Gaseous Emissions Measurements (NOx, CO, CO2» O2, HC, SO2 17
4.1.1 Analytical Instruments and Related Equipment ... 17
4.1.2 Gas Sampling and Conditioning System 22
4.1.3 Continuous Measurements 22
4.2 Sulfur Oxides (SOx) 24
4.3 Particulate Measurement and Procedures 26
4.4 Particle Size Distribution Measurement and Procedure . . 26
4.5 Coal Sampling and Analysis Procedure 30
4.6 Ash Collection and Analysis for Combustibles 31
4.7 Boiler Efficiency Evaluation 31
4.8 Trace Species Measurement 32
5.0 TEST RESULTS AND OBSERVATIONS 35
5.1 Overfire Air 35
5.1.1 Particulate Loading vs Overfire Air 37
5.1.2 Nitric Oxide vs Overfire Air 37
5.1.3 Carbon Monoxide and Unburned Hydrocarbons vs Over-
fire Air 38
5.1.4 Boiler Efficiency vs Overfire Air 39
5.2 Flyash Reinjection 39
5.2.1 Reduced Flyash Reinjection, Test No. 23 40
5.2.2 Particulate Loadings vs Flyash Reinjection .... 41
5.2.3 Boiler Efficiency vs Flyash Reinjection 42
5.3 Excess Oxygen and Grate Heat Release 42
5.3.1 Excess Oxygen Operating Levels 42
5.3.2 Particulate Loading vs Grate Heat Release .... 44
5.3.3 Stack Opacity vs Grate Heat Release 46
5.3.4 Nitric Oxide vs Oxygen and Grate Heat Release . . 46
5.3.5 Sulfur Oxides vs Grate Heat Release 58
5.3.6 Hydrocarbons vs Oxygen and Grate Heat Release . . 61
111
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TABLE OF CONTENTS
(Continued)
Section Page
5.3.7 Carbon Monoxide vs Oxygen and Grate Heat Release . 64
5.3.8 Combustibles in the Ash vs Oxygen and Grate . . .
Heat Release 64
5.3.9 Boiler Efficiency vs Grate Heat Release 64
5.4 Coal Properties 77
5.4.1 Chemical Composition of the Coals 77
5.4.2: Coal Size Consistency 81
5.4.3 Effect of Coal Properties on Emissions and ....
Efficiency 81
5.5 Particle Size Distribution of Flyash 88
5.6 Efficiency of Multiclone Dust Collector 94
5.7 Source Assessment Sampling System " 94
5.8 Data Tables 97
APPENDIX A - English and Metric Units to SI Units 102
APPENDIX B - SI Units to English and Metric Units 103
APPENDIX C - SI Prefixes 104
APPENDIX D - Emission Units Conversion Factors 105
APPENDIX E - Units Conversion from Parts per Million (ppm) to
Pounds per Million Btu Input (Ib/lO^tu) . . . 106
IV
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LIST OF TABLES
Table Page
2-1 Emission Data Summary 8
3-1 Design Data 11
3-2 Predicted and Actual Performance Data 12
3-3 Average Coal Analysis 15
5-1 Effect of Overfire Air on Emissions and Efficiency 36
5-2 Particulate Loading vs Overfire Air 37
5-3 Nitric Oxide vs Overfire Air 38
5-4 Carbon Monoxide and Hydrocarbons vs Overfire Air 38
5-5 Boiler Efficiency vs Overfire Air 39
5-6 Economizer Ash Collection Rate, Test No. 23, Test Site F ... 40
5-7 Particulate Loading vs Flyash Reinjection 41
5-8 Ash Carryover vs Coal Type 44
5-9 Nitric Oxide vs Load at Normal Excess Air 49
5-10 Sulfur Trioxide Test Data 61
5-11 Hydrocarbon vs Boiler Load 61
5-12 Boiler Efficiency vs Load 74
5-13 Predicted vs Measured Heat Losses 75
5-14 Predicted vs Measured Performance Data 75
5-15 Calculation of Combustible Heat Loss 76
5-16 Coal Properties Corrected to a Constant lO^Btu Basis 77
5-17 Fuel Analysis - Pennsylvania A Coal 78
5-18 Fuel Analysis - Pennsylvania B Coal 79
5-19 Mineral Analysis of Coal Ash 80
5-20 As Fired Coal Size Consistency 82
5-21 Effect of Coal Change on Particulate Loading 85
5-22 Sulfur Balance - Boiler F 86
5-23 Average Hydrocarbon Concentrations vs Coal 86
5-24 Average Carbon Monoxide Concentrations vs Coal 87
5-25 Average Percent Combustible in Ash 87
5-26 Boiler Efficiency vs Coal 88
5-27 Description of Particle Size Distribution Tests at the Boiler
Outlet 89
5-28 Results of Particle Size Distribution Tests at the Boiler
Outlet 90
5-29 Efficiency of Dust Collector 95
5-30 Polynuclear Aromatic Hydrocarbons Analyzed in the Site F SASS
Sample 94
5-31 Particulate Emissions 97
5-32 Heat Losses and Efficiencies 98
5-33 Percent Combustibles in Refuse 99
5-34 Steam Flows and Heat Release Rates 100
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LIST OF FIGURES
Figure Page
3-1 Schematic of Boiler F 10
3-2 Boiler F Sample Plane Geometry 14
4-1 Flue Gas Sampling and Analyzing System 23
4-2 Schematic of Goksoyr-Ross Controlled Condensation System (CCS) 25
4-3 EPA Method 5 Particulate Sampling Train 27
4-4 Brink Cascade Impactor Sampling Train Schematic 29
4-5 Source Assessment Sampling (SASS) Flow Diagram 33
5-1 Oxygen vs Grate Heat Release 43
5-2 Economizer Out Part, vs Grate Heat Release 45
5-3 Multiclone Out Part, vs Grate Heat Release 47
5-4 Opacity vs Grate Heat Release 48
5-5 Nitric Oxide vs Grate Heat Release 50
5-6 Nitric Oxide vs Oxygen 51
5-7 Nitric Oxide vs Oxygen 52
5-8 Nitric Oxide vs Oxygen 53
5-9 Nitric Oxide vs Oxygen 54
5-10 Nitric Oxide vs Oxygen 55
5-11 Nitrogen Dioxide vs Grate Heat Release 56
5-12 Nitrogen Dioxide vs Oxygen 57
5-13 Sulfur Dioxide vs Fuel Sulfur as SO2 59
5-14 Sulfur Dioxide vs Grate Heat Release 60
5-15 Hydrocarbon vs Grate Heat Release 62
5-16 Hydrocarbon vs Oxygen 63
5-17 Carbon Monoxide vs Grate Heat Release 65
5-18 Carbon Monoxide vs Oxygen 66
5-19 Economizer Out Comb vs Grate Heat Release 67
5-20 Multiclone Out Comb vs Grate Heat Release 68
5-21 Bottom Ash Comb vs Grate Heat Release 69
5-22 Economizer Out Comb vs Oxygen 70
5-23 Multiclone Out Comb vs Oxygen 71
5-24 Bottom Ash Comb vs Oxygen 72
5-25 Boiler Efficiency vs Grate Heat Release 73
5-26 Size Consistency of "As Fired" Penn A Coal vs ABMA Recommended
Limits of Coal Sizing for Spreader Stokers - Test Site F . 83
5-27 Size Consistency of "As Fired" Penn B Coal vs ABMA Recommended
Limits of Coal Sizing for Spreader Stokers - Test Site F . 84
5-28 Particle Size Distribution at the Economizer Outlet from Bahco
Classifier - Test Site F 91
5-29 Particle Size Distribution at the Economizer Outlet from
Brink Cascade Impactor - Test Site F 92
5-30 Particle Size Distribution at the Economizer Outlet from
SASS Gravimetrics - Test Site F 93
5-31 Multiclone Efficiency vs Grate Heat Release 96
VI
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1.0 INTRODUCTION
The principal objective of the test program described in this report,
one of several reports in a series, is to produce information which will in-
crease the ability of boiler manufacturers to design and fabricate stoker
boilers that are an economical and environmentally satisfactory alternative to
oil-fired units. Further objectives of the program are to: provide information
to stoker boiler operators concerning the efficient operation of their boilers;
provide assistance to stoker boiler operators in planning their coal supply
contracts; refine application of existing pollution control equipment with
special emphasis on performance; and contribute to the design of new pollution
control equipment.
In order to meet these objectives, it is necessary to define stoker
boiler designs which will provide efficient operation and minimum gaseous and
particulate emissions, and define what those emissions are in order to facili-
tate preparation of attainable national emission standards for industrial size,
coal-fired boilers. To do this, boiler emissions and efficiency must be
measured as a function of coal analysis and sizing, rate of flyash reinjection,
overfire air admission, ash handling, grate size, and other variables for
different boiler, furnace, and stoker designs.
A field test program designed to address the objectives outlined above
was awarded to the American Boiler Manufacturers Association (ABMA), sponsored
by the United States Department of Energy (DOE) under contract number
EF-77-C-01-2609, and co-sponsored by the United States Environmental Protection
Agency (EPA) under inter-agency agreement number IAG-D7-E681. The program is
directed by an ABMA Stoker Technical Committee which, in turn, has subcontracted
the field test portion to KVB, Inc., of Minneapolis, Minnesota.
This report is the Final Technical Report for the sixth of eleven
boilers to be tested under the ABMA program. It contains a description of the
facility tested, the coals fired, the test equipment and procedures, and the
results and observations of testing. There is also a data supplement to this
report containing the "raw" data sheets from the tests conducted. The data
-------
supplement has the same EPA report number as this report except that it is
followed by "b" rather than"a". As a compilation of all data obtained at
this test site, the supplement acts as a research tool for further data
reduction and analysis as new areas of interest are uncovered in subsequent
testing.
At the completion of this program, a final technical report will com-
bine and correlate the test results from all sites tested. A report containing
operating guidelines for boiler operators will also be written, along with a
separate report covering trace species data. These reports will be available
to interested parties through the EPA Technical Information Section and NTIS.
Although it is EPA policy to use S.I. units in all EPA sponsored
reports, an exception has been made herein because English units have been
conventionally used to describe boiler design and operation. Conversion
tables are provided in the Appendix for those who prefer S.I. units.
To protect the interests of the host boiler facilities, each test
site in this program has been given a letter designation. As the sixth
site tested, this is the final technical report for Test Site F under the
program entitled, "A Testing Program to Update Equipment Specifications and
Design Criteria for Stoker Fired Boilers."
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2.0 EXECUTIVE SUMMARY
A coal fired spreader stoker rated at 80,000 Ibs steam/hr was
extensively tested for emissions and efficiency between December 18, 1978,
and February 14, 1979. This section summarizes the results of these tests
and provides references to supporting figures, tables and commentary found
in the main text of the report.
UNIT TESTED; Described in Section 3.0, pages 9-13.
9 Keeler Boiler
Built 1977
Type MKB
80,000 Ibs/hr rated capacity
150 psig operating steam pressure
Saturated steam
Economizer
9 Detroit Rotograte Stoker
Spreader type
Traveling grate with front ash discharge
Flyash reinjection from economizer and boiler hopper
Two rows OFA on front and two rows on back water walls
COALS TESTED; Individual coal analysis results given in Tables 5-17, 5-18
and 5-19, pages 78-80. Commentary in Section 3.0, page 13.
^ Pennsylvania A Coal
13,242 Btu/lb
10.55% Ash
1.47% Sulfur
4.06% Moisture
2560°F Initial ash deformation temperature
9 Pennsylvania B Coal
13,596 Btu/lb
8.96% Ash
1.00% Sulfur
3.69% Moisture
2700+°F Initial ash deformation temperature
-------
OVERFIRE AIR TEST RESULTS; Overfire air pressure was varied over its
operating range when the boiler was operated at
design capacity (Section 5.1, pages 35-39,
Table 5-1, page 35.)
The baseline OFA configuration put most of the
OFA through the front jet. The maximum OFA
configuration shifted some of the OFA from the
front to the rear jets. This change had little
effect on emissions. An overall reduction in
OFA pressure resulted in degradation of emissions.
w Particulate Loading
Particulate loading increased 50% at the economizer outlet and
38% at the multiclone outlet when overfire air pressure was
reduced. The percentage of combustible material in the flyash
remained constant as overfire air conditions were varied. (Section
5.1.1, page 37; Table 5-2, page 37.)
^ Nitric Oxide
Nitric oxide concentration was observed to increase by 12% when
overfire air pressure was reduced. (Section 5.1.2, page 37;
Table 5-3, page 38.)
9 Carbon Monoxide and Unburned Hydrocarbons
Carbon monoxide was highest under low overfire air conditions
but remained below 700 ppm in all tests. Unburned hydrocarbons
gave mixed results in two overfire air test series. (Section
5.1.3, page 38; Table 5-4, page 38.)
^ Boiler Efficiency
Boiler efficiency decreased four percent under low overfire air
conditions. Three percent of this loss resulted from increased
combustible losses in the flyash. The remaining one percent loss
is thought to be unrelated to the change in overfire air conditions.
(Section 5.1.4, page 39; Table 5-5, page 39.)
FLYASH REINJECTION; Boiler F pneumatically reinjects flyash from the economizer
hopper. During one test this reinjection was stopped.
(Section 5.2, page 40.)
^ Economizer Collection Rate
The economizer was found to collect ten percent of the particulate
mass entering it under high load, no reinjection conditions.
(Section 5.2.1, page 40, Table 5-6, page 40.)
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9 Particulate Loading
Reduced reinjection resulted in a 5 to 27% drop in particulate
loading at the economizer outlet depending on which baseline
test it is compared to. (Section 5.2.2, page 41, Table 5-7,
page 41.)
^ Boiler Efficiency
The flyash collected by the economizer hopper represents a
potential efficiency gain of 0.6% if fully recovered through
reinjection to the furnace. (Section 5.2.3, page 42.)
BOILER EMISSION PROFILES; Boiler emissions and efficiency were measured
over the load range 52-102% of design capacity
which corresponds to a grate heat release range
of 338,000 to 693,000 Btu/hr-ft2. Measured
oxygen levels ranged from 4.6 to 12.7%. (Section
5.3, page 42.)
w Excess Oxygen Operating Levels
At full capacity, the boiler was able to meet the manufacturers
design performance of 30% excess air (5% oxygen). More excess
air was required at lower loads. (Section 5.3.1, page 42;
Figure 5-1, page 43.)
9 Particulate Loading
At full load and normal operating conditions, the particulate
loading averaged 6.00^0.75 lbs/106Btu at the economizer outlet
and 1.05+0.20 lbs/106 Btu at the multiclone outlet. At 75% of
capacity, the economizer outlet particulate loadings were 20%
lower than at full load. On the average, 24% of the coals'
ash was carried over as flyash. (Section 5.3.2, page 44; Table
5-8, page 44, Figures 5-2 and 5-3, pages 45 and 47.)
^ Stack Opacity
Stack opacity remained low at all loads tested. (Section 5.3.3,
page 46; Figure 5-4, page 48.)
9 Nitrogen Oxides
Nitric oxide (NO) increased by 0.051 lbs/10 Btu for each one
percent increase in oxygen at constant load. NO also increased
with increasing load at constant 02- However, because excess oxygen
decreased with increasing load under normal firing conditions,
nitric oxide averages about 0.45 lbs/10^ Btu (330 ppm) at all
loads.
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Nitrogen Dioxide (NO2) averaged 0.005 lbs/106 Btu (4 ppm) at
all loads and showed a tendency to increase with increasing 02
at the lower loads. (Section 5.3.4, page 46; Table 5-9,
page 49; Figures 5-5 through 5-12, pages 50-57.)
Sulfur Oxides
Four percent of the fuel sulfur was retained in the ash while
the remaining 96% was converted to SO2 and 803. (Section 5.3.5,
page 58; Figures 5-13 and 5-14, pages 59-60, Table 5-10,
page 61.)
Hydrocarbons
Unburned hydrocarbons averaged 7.6 ppm at full load, 14.8 ppm
at 75% load and 0.0 ppm at 50% load. (Section 5.3.6, page 61j
Table 5-11, page 61; Figures 5-15 and 5-16, pages 62-63.)
Carbon Monoxide
Carbon monoxide remained below 400 ppm except under high load
low O2 conditions and low load high O2 conditions. (Section
5.3.7, page 64; Figures 5-17 and 5-18, pages 65-66.)
Combustibles in the Ash
Combustibles averaged 67% in the economizer outlet flyash,
47% in the multiclone outlet flyash, and 12% in the bottom ash.
In general, they did not vary with load or O2. (Section 5.3.8,
page 64; Figures 5-19 thru 5-24, pages 67-72.)
BOILER EFFICIENCY; Boiler efficiency averaged 78.1% at full load, 80.3% at
75% load, and 81.5% at 50% load. The manufacturers
predicted efficiency was 83.1% and reflects a much lower
combustible heat loss. (Section 5.3.9, page 64, Tables
5-12, 5-13 and 5-14, pages 74-75; Figure 5-25, page
73.)
COAL PROPERTIES; Perm B coal was lower in ash (8.96 vs 10.55%) and lower
in sulfur (1.00% vs 1.47%) than the Penn A coal. However,
with the exception of sulfur oxide emissions, the change
in coals had no impact on boiler emissions or efficiency.
(Section 5.4, page 77; Tables 5-16 thru 5-26, pages 77-88.)
PARTICLE SIZE DISTRIBUTION OF FLYASH; Eleven particle size distribution measure-
ments were made at the economizer outlet.
Results vary with measurement technique.
(Section 5.5, page 88; Tables 5-27 and
5-28, pages 89 & 90; Figures 5-28, 5-29
and 5-30, pages 91-93.)
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EFFICIENCY OF MULTICLONE DUST COLLECTOR; Multiclone collection efficiency
averaged 82% at full load compared to
the manufacturers design efficiency of
85%. At 75% load the efficiency
dropped to 78%. (Section 5.6, page 94;
Figure 5-31, page 96; Table 5-20,
page 82.)
SOURCE ASSESSMENT SAMPLING SYSTEM; Flue gas was sampled for polynuclear
aromatic hydrocarbons and trace elements
during one full load test on each of the
two coals. Data will be presented in a
separate report at completion of test pro-
gram. (Section 5.7, page 94; Table 5-30,
page 94.)
The emissions data are 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 the unre-
duced data obtained at Site F 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.
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TABLE 2-1
EMISSION DATA SUMMARY
TEST SITE F
Test
No.
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
10ft
16B
16C
17
18
19
20
21
22
23
24
23A
25
26
27
28
29
30
31
32
33
34
35
Date
12/18/78
12/18/78
12/18/79
12/18/79
12/19/78
12/20/78
12/20/78
12/20/78
12/20/78
1/04/79
1/05/79
1/05/79
1/05/79
1/05/79
1/08/79
1/09/79
1/09/79
1/09/79
1/10/79
1/15/79
1/16/79
1/17/79
1/24/79
1/31/79
2/01/79
2/06/79
2/08/79
2/12/79
2/12/79
2/12/79
2/12/79
2/12/79
2/13/79
2/14/79
2/14/79
2/14/79
2/14/79
2/14/79
Load
%
75
75
75
75
54
53
53
53
53
98
99
99
99
99
99
100
100
100
99
99
99
75
76
99
100
102
99
99
99
99
99
101
97
75
75
75
75
76
Coal
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
B
Excess
Air
Test Description %
Med Load
Low Load
Low Load
High Load
High Load
High Load
High Load
High Load
High Load
High Load
Med Load
Med Load
High Load
High Load
High Load
High Load
High Load
High Load
High Load
Med Load
Med Load
- Baseline
- High 02
- High O2
- Low O2
- Baseline
- Baseline
- Med High 02
- Low O2
- High O2
- Baseline
- Baseline
- High O2
- Low O2
- Med O2
- High O2
- Baseline OFA
- Max OFA
- Low OFA
- Low O2
- High OFA
- Low OFA
- Baseline
- Baseline
- Optimum O2 OFA
- Optimum O2 OFA
- Optimum O2 OFA
- Optimum O2 OFA
- High 02
- Baseline
- Med Low O2
- Low O2
- Optimum 02 OFA
- Optimum O2 OFA
- Baseline
- High O2
- Med Low O2
- Low O2
- Baseline
69
78
97
56
77
69
112
50
144
61
59
65
32
42
56
54
50
63
45
34
37
63
58
38
41
30
37
61
47
41
26
29
45
84
115
61
40
67
°2
%
dry
8.9
9.5
10.7
7.8
9.4
8.8
11.3
7.2
12.7
8.2
8.1
8.5
5.4
6.4
7.8
7.6
7.2
8.3
6.7
5.5
5.9
8.4
8.0
6.0
6.3
5.0
5.9
8.3
7.0
6.4
4.6
5.0
6.8
9.9
11.5
8.2
6.2
8.7
C02
%
dry
10.0
9.6
8.2
11.6
10.0
10.6
9.0
12.5
7.3
11.1
10.8
11.0
12.8
12.8
11.1
12.0
12.8
11.8
12.5
13.4
12.6
10.7
11.0
13.2
13.2
14.5
12.5
10.3
11.6
11.8
12.8
13.3
11.7
9.2
8.4
11.4
12.4
10.7
CO
ppm
dry
146
173
233
137
175
112
252
77
420
252
231
222
612
251
250
228
163
378
382
429
607
100
107
352
221
549
186
172
253
198
437
361
284
139
207
78
96
107
NO
ppm
dry
343
395
426
322
297
294
369
237
442
348
413
397
269
309
384
DOS
COS
COS
DOS
263
309
342
314
281
298
289
282
395
323
297
264
266
299
328
452
290
228
380
NO
lb/106
Btu
0.467
0.538
0.580
0.439
0.405
0.401
0.503
0.323
0.602
0.474
0.563
0.541
0.366
0.421
0.523
DOS
OOS
COS
OOS
0.358
0.421
0.466
0.428
0.384
0.406
0.392
0.384
0.538
0.440
0.405
0.360
0.362
0.391
0.447
0.616
0.395
0.311
0.517
NO2
lb/106
Btu
0.001
0.007
0.010
0.004
0.004
0.004
0.015
0.008
0.011
0.000
0.010
0.004
0.003
0.000
0.001
OOS
OOS
OOS
OOS
0.007
0.007
0.004
0.003
0.001
0.003
0.000
0.004
0.035
0.004
0.003
0.011
0.001
0.000
0.007
O.OO5
0.000
0.001
SO2
lb/106
Btu
1.828
1.600
1.429
1.815
1.758
2.057
2.229
2.151
2.188
2.022
2.254
2.147
2.146
2.254
1.871
1.807
1.919
1.919
1.846
2.150
2.297
2.107
2.425
2.188
2.049
2. 182
2.6B6
1.369
1.328
1.369
1.330
1.342
1.342
1.179
1.475
1.232
1.236
HC Part
ppm Econ Out
wet lb/106Btu
0
14
18
28
0
0
0
0
0
0
0
0
12
12
1
13
13
0
9
5
16
15
27
16
12
OOS
OOS
OOS
OOS
OOS
OOS
OOS
5
14
8
14
10
5.076
--
5.926
5.510
6.136
8.785
4.008
5.567
5.240
7.183
5.944
--
--
--
4.726
Part
D.C. Out Opacity Special
lb/106Btu * Tests
--
--
1.329
1.13O
0.771
1.256
1.262
--
0.998
1.031
--
--
1.392
--
--
1.026
8.0
8.0
8.0
8.0
8.0
2.2
2.3
2.2
2.2
2.5
2.5
2.5
2.5
2.5
2.9
2.5
2.5
4.8
3.9
OOS
4.2
3.2
OOS
OOS SASS, SO 3
OOS Brink (no reinj)
OOS Brink
OOS Brink (no reinj )
OOS
OOS
OOS
OOS
OOS Brink
OOS SASS, S03
OOS
OOS
OOS
OOS
OOS
CO
A - Penn A Coal
B - Penn B Coal
OOS - Analyzer out of service
ppm - parts per million by volume corrected to 3%
Load - % of units design capacity
-------
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 F. The coals used in this
test series are also discussed.
3.1 BOILER F DESCRIPTION
Boiler F was built by E. Keeler Company in 1977 and equipped with a
spreader stoker from Detroit Stoker Company. The boiler is rated at 80,000
Ibs/hour continuous operation at 150 psig saturated steam. It has a multiple
pass boiler section, tubular economizer and mechanical dust collector. A
boiler schematic is presented in Figure 3-1.
The Detroit Rotograte stoker has three coal feeders and continuous
2
front end ash discharge. The effective area of the grate is 141.4 ft .
Design data on the boiler and stoker are presented in Table 3-1. Predicted
performance data and the results of a 1977 acceptance test are presented
in Table 3-2.
3.2 OVERFIRE AIR SYSTEM
The boiler is equipped with both front and rear overfire air. There
are upper and lower jets on both water walls.
3.3 FLYASH REINJECTION
Flyash is pneumatically reinjected from both the boiler dust hopper
and the economizer dust hopper, but not from the mechanical dust collector.
During two tests at this site, flyash reinjection from the economizer dust
hopper was interrupted in an attempt to determine boiler efficiency gains due
to reinjection from economizer hopper.
-------
D ~
FLYASH
REINJECTION
DUST
COLLECTOR
FLYASH
REINJECTION
FIGURE 3-1. Schematic of Boiler F
a - Economizer Outlet Sampling Plant
b - Dust Collector Sampling Plane
10
-------
TABLE 3-1
DESIGN DATA
TEST SITE F
BOILER: Manufacturer E. Keeler Company
Type MKB Type
Boiler Heating Surface 8,980 ft2
Design Pressure 200 psig
Tube Diameter 2-1/2 "
ECONOMIZER: Type Tubular
Heating Surface 3,017 ft
Design Pressure 250 psig
Tube Diameter
FURNACE: Volume 4,150 ft3
STOKER: Manufacturer Detroit Stoker
Type Rotograte
Width 10'10.5"
Length 14' 8"
Effective Grate Area 141.4 ft2
HEAT RATES: Steam Flow 80,000 Ibs/hr
Input to Furnace 97.5xl06Btu/hr
Furnace Width Heat Release 8.96xl06Btu/ft-hr
Grate Heat Release 688x103Btu/ft2-hr
Furnace Liberation 23.5xl03Btu/ft3-hr
11
-------
TABLE 3-2
PREDICTED AND ACTUAL PERFORMANCE DATA
Guarantee
Maximum
Continuous
1977
Acceptance
Test
Steam Flow, Ibs/hr
Heat Output, 106Btu/hr
Fuel Burned, Ibs/hr
Steam Pressure, psig
Steam Temperature, °F
F.W. to Economizer, °F
F.W. to Boiler, °F
Ambient Air Temperature, °F
Gas Temp. Leaving Furn., °F
Gas Temp. Leaving Boiler, °F
Gas Temp. Leaving Econ., °F
Excess Air at Boiler Exit, %
Excess Air at Econ. Exit, %
Air Entering Unit, Ibs/hr
Wet Gas at Furnace Exit, Ibs/hr
Wet Gas at Econ. Exit, Ibs/hr
Furnace Draft Loss, "H2O
Boiler Draft Loss, "H2O
Economizer Draft Loss, "H2O
Dust Collector Draft Loss, "H2O
Flues, Dampers Draft Loss, "H2O
Stack Draft Loss, "H2O
Total Loss, "H20
Liberation, Furnace Vol., Btu/hr-ft3
Meter Pressure Drop Through Economizer, psi
80,000
80.73
7,205
150
Saturated
228
289
80
1,900
560
350
30
30
97,270
95,480
99,200
0.15
1.00
3.30
2.50
0.65
7.60
23,450
7.5
81,803
82.37
143.8
Saturated
220
318
542
377
37
110,887
24,199
Dry Gas Losses, %
H2 in Fuel Losses, %
Moisture in Fuel and Air Losses,
Unburned Combustibles, %
Radiation, %
Unaccounted, %
Total Losses, %
Efficiency, %
6.33
3.63
0.16
4.70
0.58
1.50
16.90
83.10
7.60
4.10
0.34
4.10
0.58
1.50
18.35
81.65
12
-------
3.4 TEST PORT LOCATIONS
Emission measurements were made at two locations at the economizer
outlet and at the dust collector outlet. The locations of these sample sites
are shown in Figure 3-1. Their geometry is shown in Figure 3-2.
Whenever particulate loading was measured, it was measured
simultaneously at both locations using 12-point traverses. Gaseous measure-
ments of 02, CO2/ CO, NO, NO2, SO2 and HC were obtained by pulling samples
individually and compositely from selected points. SO-^ measurements, Brink
samples for flyash sizing and SASS samples for organic and trace element
determinations were each obtained from single points within the duct.
3.5 PARTICULATE COLLECTION EQUIPMENT
The boiler is equipped with a Zurn mechanical dust collector. The
collector has 63 tubes of 9-inch diameter and has a design efficiency of 85%.
3.6 COALS UTILIZED
Two coals were fired at Test Site F. These are referred to as
Pennsylvania A coal and Pennsylvania B coal in this report. Coal samples were
taken for each test involving particulate or SASS sampling. The average coal
analyses obtained from these samples are presented in Table 3-3. The primary
coal at this site was Pennsylvania A. The secondary coal was specially pre-
pared washed and mechanically treated high grade metallurgical coal.
While Pennsylvania B coal was lower in both ash and sulfur content than Pennsyl-
vania A coal, the differences are not great and, as a matter of fact, these
slight differences in the coal had little impact on the combustion and emission
characteristics of the boiler. The analyses of each individual coal sample
are presented in Section 5.0, Test Results and Observations, Tables 5-17 through
5-19.
13
-------
9'5"
DOO
32"
A+ Q
Economizer Outlet Sampling Plane
Cross Sectional Area = 25.11 ft2
43"
1
-I-
43"
Dust Collector Outlet Sampling Plane
Cross Sectional Area = 12.84 ft2
+- Particulate Mass Sampling Point
O Gaseous Sampling Point
Q SASS Sampling Point
A 503 Sampling Point
Brink Sampling Point
FIGURE 3-2. Boiler F Sample Plane Geometry
14
-------
TABLE 3-3
AVERAGE COAL ANALYSIS
TEST SITE F
Penn A Coal Perm B Coal
PROXIMATE (As Rec'd)
% Moisture 4.06 3.69
% Ash 10.55 8.96
% Volatile 22.74 25.75
% Fixed Carbon 62.65 61.61
Btu/lb 13242 13596
% Sulfur 1.47 1.00
ULTIMATE (As Rec'd)
% Moisture 3.28 3.69
% Carbon 75.14 76.36
% Hydrogen 4.61 4.69
% Nitrogen 1.23 1.12
% Chlorine . 0.15 0.17
% Sulfur 1.42 1.00
% Ash 10.52 8.96
% Oxygen (Diff) 3.68 4.03
15
-------
4.0 TEST EQUIPMENT AND PROCEDURES
This section details how specific emissions were measured and
describes the sampling procedures followed to assure that accurate, reliable
data were collected.
4.1 GASEOUS EMISSIONS MEASUREMENTS (NOx, CO, CO2, O2, HC, SO2)
A description is given below of the analytical instrumentation, re-
lated equipment, and the gas sampling and conditioning system, all of which
are located in a mobile testing van owned by the EPA and operated by KVB.
The systems have been developed as a result of testing since 1970, and are
operational and fully checked out.
4.1.1 Analytical Instruments and Related Equipment
The analytical system consists of five instruments and associated
equipment for simultaneously measuring the constituents of flue gas. The
analyzers, recorders, valves, controls, and manifolds are mounted on a panel
in the vehicle. The analyzers are shock mounted to prevent vibration damage.
The flue gas constituents which are measured are oxides of nitrogen (NO, NOx),
carbon monoxide (CO), carbon dioxide (CO2), oxygen (02), gaseous hydrocarbons
(HC), and sulfur dioxide (SO2).
Listed below are the measurement parameters, the analyzer model
furnished, and the range and accuracy of each parameter for the system. A
detailed discussion of each analyzer follows:
Constituent: Nitric Oxide/Total Oxides of Nitrogen (NO/NOx)
Analyzer: Thermo Electron Model 10 Chemiluminescent Analyzer
Range: 0-2.5, 10, 25, 100, 250, 1000, 2500, 10,000 ppm NO
Accuracy: ±1% of full scale
Constituent: Carbon Monoxide
Analyzer: Beckman Model 315B NDIR Analyzer
Range: 0-500 and 0-2000 ppm CO
Accuracy: ±1% of full scale
17
-------
Constituent: Carbon Dioxide
Analyzer: Beckman Model 864 NDIR Analyzer
Range: 0-5% and 0-20% CO2
Accuracy: ±1% of full scale
Constituent: Oxygen
Analyzer: Teledyne Model 326A Fuel Cell Analyzer
Range: 0-5, 10, and 25% 02 full scale
Accuracy: -1% of full scale
Constituent: Hydrocarbons
Analyzer: : Beckman Model 402 Flame lonization Analyzer
Range: 5 ppm full scale to 10% full scale
Accuracy: ^1% of full scale
Constituent: Sulfur Dioxide
Analyzer: Dupont Model 400 Photometric Analyzer
Range: 0-200 ppm and 0-2000 ppm
Accuracy: ±1% of reading plus -1/4% of full scale range
Oxides of Nitrogen. The instrument used to monitor oxides of nitrogen
is a Thermo Electron chemiluminescent nitric oxide analyzer. The instrument
operates by measuring the chemiluminescent reaction of NO and 0^ to form NO2.
Light is emitted when electronically excited NO2 molecules revert to their
ground state. The resulting chemiluminescence is monitored through an optical
filter by a high sensitivity photomultiplier, the output of which is linearly
proportional to the NO concentration.
Air for the ozonator is drawn from ambient air through a dryer and"
a ten micrometer filter element. Flow control for the instrument is accomplished
by means of a small bellows pump mounted on the vent of the instrument down-
stream of a separator that prevents water from collecting in the pump.
The basic analyzer is sensitive only to NO molecules. To measure NOx
(i.e., NO+N02), the N02 is first converted to NO. This is accomplished by a
converter which is included with the analyzer. The conversion occurs as the
gas passes through a thermally insulated, resistance heated, stainless steel
coil. With the application of heat, NO2 molecules in the sample gas are re-
duced to NO molecules, and the analyzer now reads NOx. NO2 is obtained by the
difference in readings obtained with and without the converter in operation.
Specifications: Accuracy 1% of full scale
Span stability -1% of full scale in 24 hours
Zero stability -1 ppm in 24 hours
Power requirements 115-10V, 60 Hz, 1000 watts
18
-------
Response 90% of full scale in 1 sec. (NOx mode),
0.7 sec. NO mode
Output 4-20 ma
Sensitivity 0.5 ppm
Linearity il% of full scale
Vacuum detector operation
Range: 2.5, 10, 25, 100, 250, 1000, 2500, 10,000 ppm
full scale
Carbon Monoxide. Carbon monoxide concentration is measured by a
Beckman 315B non-dispersive infrared analyzer. This instrument measures the
differential in infrared energy absorbed from energy beams passed through a
reference cell (containing a gas selected to have minimal absorption of infra-
red energy in the wavelength absorbed by the gas component of interest) and a
sample cell through which the sample gas flows continuously. The differential
absorption appears as a reading on a scale from 0 to 100 and is then related
to the concentration of the specie of interest by calibration curves supplied
with the instrument. The operating ranges for the CO analyzer are 0-500 ppm
and 0-2000 ppm.
Specifications: Span stability il% of full scale in 24 hours
Zero stability ±1% of full scale in 24 hours
Ambient temperature range 32°F to 120°F
Line voltage 115-15V rms
Response 90% of full scale in 0.5 or 2.5 sec.
Precision il% of full scale
Output 4-20 ma
Carbon Dioxide. Carbon dioxide concentration is measured by a Beckman
Model 864 short path-length, non-dispersive infrared analyzer. This instrument
measures the differential in infrared energy absorbed from energy beams passed
through a reference cell (containing a gas selected to have minimal absorption
of infrared energy in the wavelength absorbed by the gas component of interest)
and a sample cell through which the sample gas flows continuously. The dif-
ferential absorption appears as a reading on a scale from 0 to 100 and is then
related to the concentration of the specie of interest by calibration curves
supplied with the instrument. The operating ranges for the CO2 analyzer are
0-5% and 0-20%.
Specifications: Span stability ll% of full scale in 24 hours
Zero stability ±1% of full scale in 24 hours
Ambient temperature range 32°F to 120°F
Line voltage 115il5V rms
Response 90% of full scale in 0.5 or 2.5 sec.
19
-------
Precision il% of full scale
Output 4-20 ma
Oxygen. The oxygen content of the flue gas sample is automatically
and continuously determined with a Teledyne Model 326A Oxygen analyzer.
Oxygen in the flue gas diffuses through a Teflon membrane and is reduced
on the surface of the cathode. A corresponding oxidation occurs at the anode
internally and an electric current is produced that is proportional to the
concentration of oxygen. This current is measured and conditioned by the
instrument's electronic circuitry to give a final output in percent ©2 by
volume for operating ranges of 0% to 5%, 0% to 10%, or 0% to 25%.
Specifications: Precision -1% of full scale
Response 90% in less than 40 sec.
Sensitivity 1% of low range
Linearity -1% of full scale
Ambient temperature range 32-125°F
Fuel cell life expectancy 40,000%-hours
Power requirement 115 VAC, 50-60 Hz, 100 watts
Output 4-20 ma
Hydrocarbons. Hydrocarbons are measured using a Beckman Model 402
hydrocarbon analyzer which utilizes the flame ionization method of detection.
The sample is drawn to the analyzer through a heated line to prevent the loss
of higher molecular weight hydrocarbons. It is then filtered and supplied to
the burner by means of a pump and flow control system. The sensor, which is
the burner, has its flame sustained by regulated flows of fuel (40% hydrogen
plus 60% helium) and air. In the flame, the hydrocarbon components of the
sample undergo a complete ionization that produces electrons and positive ions.
Polarized electrodes collect these ions, causing a small current to flow
through a circuit. This ionization current is proportional to the concentration
of hydrocarbon atoms which enter the burner. The instrument is available with
range selection from 5 ppm to 10% full scale as 014.
Specifications: Full scale sensitivity, adjustable from 5 ppm 014 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
20
-------
Electronic stability -1% of full scale for successive
identical samples
Reproducibility il% of full scale for successive
identical samples
Analysis temperature: ambient
Ambient temperature 32°F to 110°F
Output 4-20 ma
Air requirements 350 to 400 cc/min of clean, hydro-
carbon-free air, supplied at 30 to 200 psig
Fuel gas requirements 75 to 80 cc/min of pre-mixed
fuel consisting of 40% hydrogen and 60% nitrogen
or helium, supplied at 30 to 200 psig
Electrical power requirements 120V, 60 Hz
Automatic flame-out indication and fuel shut-off valve
Sulfur Dioxide. Sulfur dioxide is measured by a Dupont Model 400
photometric analyzer. This analyzer measures the difference in absorption of
two distinct wavelengths (ultraviolet) by the sample. The radiation from a
selected light source passes through the sample and then into the photometer
unit where the radiation is split by a semi-transparent mirror into two
beams. One beam is directed to a phototube through a filter which removes all
wavelengths except the "measuring" wavelength, which is strongly absorbed by
the constituent in the sample. A second beam falls on a reference phototube,
after passing through an optical filter which transmits only the "reference"
wavelength. The latter is absorbed only weakly, or not at all, by the con-
stituent in the sample cell. The phototubes translate these intensities to
proportional electric currents in the amplifier. In the amplifier, full
correction is made for the logarithmic relationships between the ratio of the
intensities and concentration or thickness (in accordance with Beer's Law).
The -output is, therefore, linearly proportional, at all times, to the concen-
tration and thickness of the sample. The instrument has a lower detection
limit of 2 ppm and full scale ranges of 0-200 and 0-2000 ppm.
Specifications: Noise less than 1/4%
Drift less than 1% full scale in 24 hours
Accuracy (ll% of analyzer reading)+(il/4% of full scale
range)
Sample cell 304 stainless steel, quartz windows
Flow rate 6 CFH
Light source is mercury vapor, tungsten, or "Osram"
discharge type lamps
Power rating 500 watts maximum, 115 V, 60 Hz
Reproducibility 1/4% of scale
Electronic response 90% in 1 sec
Sample temperature 378 K (220°F)
Output 4-20 ma d.c.
21
-------
4.1.2 Gas Sampling and Conditioning System
A flow schematic of the flue gas sampling and analysis system is
shown in Figure 4-1. The sampling system uses 3 positive displacement diaphragm
pumps to continuously draw flue gas from the stack into the laboratory. The
sample pumps pull from 6 unheated sample lines. Selector valves allow com-
posites of up to 6 points to be sampled at one time. The probes are con-
nected to the sample pumps with 0.95 cm (3/8") or 0.64 cm (1/4") nylon line.
The positive displacement diaphragm sample pumps provide unheated sample gas
to the refrigerated condenser (to reduce the dew point to 35°F), a rotameter
with flow control valve, and to the 02, NO, CO, and (X>2 instrumentation. Flow
to the individual analyzers is measured and controlled with rotameters and
flow control valves. Excess sample is vented to the atmosphere.
To obtain a representative sample for the analysis of NO2, SO2 and
hydrocarbons, the sample must be kept above its dew point, since heavy hydro-
carbons may be condensible and S02 and N02 are quite soluble in water. For
this reason, a separate, electrically-heated, sample line is used to bring the
sample into the laboratory for analysis. The sample line is 0.64 cm (1/4-inch)
Teflon line, electrically traced and thermally insulated to maintain a sample
temperature of up to 400°F. Metal bellows pumps provide sample to the hydro-
carbon, S02 and NOx analyzers.
4.1.3 Continuous Measurements
The laboratory trailer is equipped with analytical instruments to
continuously measure concentrations of NO, NO2, CO, CO2f O2, SO2, and hydro-
carbons. All of the continuous monitoring instruments and sample handling
system are mounted in the self-contained mobile laboratory. The entire system
requires only connection to on-site water, power, and sampling lines to be-
come fully operational. The instruments themselves are shock mounted on a metal
console panel. The sample flow control measurement, and selection, together
with instrument calibration are all performed from the console face.
22
-------
to
Hot
Sample Dry Sample Linea
Line (Typical Set-Up Six Linei)
Heated Line
[5] Filters
Pump,
111
PE, flovneters It)
Refrigeration Condenser
^OSample Pressure
lero flftSp.n
Condenser
6
pot/Cold
Switch
FIGUPE 4-1. Flue Gas Sampling and Analyzing System
-------
4.2 SULFUR OXIDES (SOx)
Goksoyr-Ross Method Wet Chemical Method
The Goksoyr-Ross Controlled Condensate (G/R) method is used for the
wet chemical SO2/SC<3 determination. It is a desirable method because of its
simplicity and clean separation of particulate matter, SC>2 and H2SC>4 (803).
This procedure is based on the separation of H2SO4(SC>3) from SO2 by cooling
the gas stream below the dew point of H2SO4 but above the H2O dew point.
Figure 4-2 illustrates schematically the G/R test system.
Particulate matter is first removed from exhaust gas stream by
means of a quartz glass filter placed in the heated glass filter holder.
Tissue-quartz filters are recommended because of their proven inertness to
H2SO4. The filter system is heated by a heating tape so that the gas out
temperature of 260°C (500°F) is maintained. This temperature is imperative
to ensure that none of the H2SO4 will condense in the filter holder or on the
filter.
The condensation coil where the H2S04 is collected is cooled by water
which is maintained at 60°C (140°F) by a heater/recirculator. This temperature
is adequate to reduce the exhaust gas to below the dew point of
Three impingers are shown in Figure 4-2. The first impinger is
filled with 3% H2C>2 to absorb SO2. The second impinger is to remove carry
over moisture and the third contains a thermometer to measure the exhaust gas
temperature to the dry gas meter and pump. The sampling rate is 2.3 1pm (0.08
CFM) .
For both SC>2 and H2S04 determination, the analytical procedure is
identical. The H2SC>4 sample is washed from the back part of the filter holder
and the coil using distilled water. The sample from the first impinger which
is assumed to be absorbed and reacted SC>2 in the form of H2SO4 is recovered
with distilled water washing. The amount of I^SC^ in the condensate from the
coil and from the H2O2 impinger is measured by H+ titration. Bromphenol Blue
is used with NaOH as the titrant.
24
-------
Adapter for Connecting Hose
TC Wei
Asbestos Cloth
Insulation
Glass-Cloth Heatin
Mantle ""
Stack
\
Gas Flow
Dry Test
Meter
Recirculator
Thermometer
Styrofoam Ice Chest
3-way
Valve
Drierite
FIGURE 4-2.
Schematic of Goksoyr-Ross Controlled
Condensation System (CCS).
25
-------
4.3 PARTICULATE MEASUREMENT AND PROCEDURES
Particulate samples are taken at the same sample ports as the gaseous
emission samples using a Joy Manufacturing Company portable effluent sampler
(Figure 4-3). This system, which meets the EPA design specifications for
Test Method 5, Determination of Particulate Emissions from Stationary Sources
(Federal Register, Volume 36, No. 27, page 24888, December 23, 1971) , is used
to perform both the initial velocity traverse and the particulate sample
collection. Dry particulates are collected in a heated case using first a
cyclone to separate particles larger than five micrometers and a 100 mm glass
fiber filter for retention of particles down to 0.3 micrometers. Condensible
particulates are collected in a train of four Greenburg-Smith impingers in an
ice water bath. The control unit includes a total gas meter and thermocouple
indicator. A pitot tube system is provided for setting sample flows to obtain
isokinetic sampling conditions.
All peripheral equipment is carried in the instrument van. This
includes a scale (accurate to ±0.1 mg), hot plate, drying oven (212°F), high
temperature oven, desiccator, and related glassware. A particulate analysis
laboratory is set up in the vicinity of the boiler in a vibration-free area.
Here filters are prepared, tare weighed and weighed again after particulate
collection. Also, probe washes are evaporated and weighed in the lab.
4.4 PARTICLE SIZE DISTRIBUTION MEASUREMENT AND PROCEDURE
Particle size distribution is measured using several methods. These
include the Brink Cascade Impactor, SASS cyclones, and the Bahco Classifier.
Each of these particle sizing methods has its advantages and disadvantages.
Brink. The Brink cascade impactor is an in-situ particle sizing de-
vice which separates the particles into six size classifications. It has the
advantage of collecting the entire sample. That is, everything down to the
collection efficiency of the final filter is included in the analysis, it
has, however, some disadvantages. If the particulate matter is spatially
stratified within the duct, the single-point Brink sampler will yield
erroneous results. Unfortunately, the particles at the outlets of stoker
boilers may be considerably stratified. Another disadvantage is the instru-
ment's small classification range (0.3 to 3.0 micrometers) and its small sample
26
-------
NJ
PROBE
THERMOMETER
PR°\E \ /
g^fe
STACK
THERMOMETER'
/
REVERSE-TYPE
PITOT TUBE
HEATED AREA
STACK
WALL
FILTER HOLDER
THERMOMETER
kr
ORIFICE
GAUGE
THERMOMETER
VELOCITY
PRESSURE
GAUGE IMP1NGERS ICE BATH
THERMOMETERS ^_ FINE CONTROL VALVE
CHECK VALVE
VACUUM LINE
VACUUM
GAUGE
COARSE CONTROL VALVE
DRY TEST METER
AIR-TIGHT
PUMP
FIGURE 4-3. EPA Method 5 Particulate Sampling Train
-------
nozzle (1.5 to 2.0 mm maximum diameter). Both are inadequate for the job at
hand. The particles being collected at the boiler outlet are often as large
as the sample nozzle.
The sampling procedure is straight forward. First, the gas velocity
at the sample point is determined using a calibrated S-type pitot tube. For
this purpose a hand held particulate probe, inclined manometer, thermocouple
and indicator are used. Second, a nozzle size is selected which will main-
tain isokinetic flow rates within the recommended .02-.07 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 calibration curve. This pressure drop is corrected for
temperature, pressure and molecular weight of the gas to be sampled.
A sample is drawn at the predetermined AP for a time period which
is dictated by mass loading and size distribution. To minimize weighing
errors, it is desirable to collect several milligrams on each stage. However,
to minimize reentrainment, a rule of thumb is that no stage should be loaded
above 10 mg. A schematic of the Brink sampling train is shown in Figure 4-4.
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 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 F came from
the cyclone in the EPA Method 5 particulate train. These samples are spatially
representative because they are taken from a 12-point sample matrix. However,
much of the sample below about seven micrometers is lost to the filter. The
Bahco test data are presented in combination with sieve analysis of the same
sample. An attempt was made to correct for the lost portion of the sample.
SASS. The Source Assessment Sampling System (SASS) was not designed
principally as a particle sizer but it includes three calibrated cyclones
which can be used as such. The SASS train is a single point in-situ sampler.
Thus, it is on a par with cascade impactors. Because it is a high volume
sampler and samples are drawn through large nozzles (0.25 to 1.0 in.), it
has an advantage over the Brink cascade impactor where large particles are
28
-------
PRESSURE TAP
- FOR 0-20"
MAGNAHELIX
CYCLONE
STAGE 1
STAGE 2
STAGE 3
STAGE 4
STAGE 5
FINAL FILTER
DRY GAS
METER
ELECTRICALLY HEATED PROBE
FLOW CONTROL
VALVE
DRYING
COLUMN
FIGURE 4-4. Brink Cascade Impactor Sampling Train Schematic
29
-------
involved. The cut points of the three cyclones are 10, 3 and 1 micrometers.
A detailed description of the SASS train is presented in Section 4.8.
4.5 COAL SAMPLING AND ANALYSIS PROCEDURE
Coal samples at Test Site F were taken during each test from the
unit's coal scale. The samples were processed and analyzed for both size
consistency and chemical composition. The use of the coal scale as a
sampling station has two advantages. It is close enough to the 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.
In order to collect representative coal samples, a sampling tray
having a twenty pound capacity was custom built. The tray has the same width
as the apron feeder belt and can be moved directly under the belt's discharge
end to catch all of the coal over a short increment of time (approximately
five seconds).
The sampling procedure is as follows. At the start of testing one
increment of sample is collected from the feeder. This is repeated five more
times during the test (three to five hours duration) so that a six increment.
sample is obtained. The sample is then riffled using a Gilson Model SP-2
Porta Splitter until two representative twenty point samples are obtained.
The sample to be used for sieve analysis is air dried overnight.
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
30
-------
sample associated with a particulate loading or particle sizing test is
given a proximate analysis. In addition, composite samples consisting of
one increment of coal for each test for each coal type receive ultimate
analysis, ash fusion temperature, mineral analysis, Hardgrove grindability
and free swelling index measurements.
4.6 ASH COLLECTION AND ANALYSIS FOR COMBUSTIBLES
The combustible content of flyash is determined in the field by
KVB in accordance with ASTM D3173, "Moisture in the Analysis Sample of Coal
and Coke" and ASTM D3174, "Ash in the Analysis Sample of Coal and Coke."
The flyash sample is collected by the EPA Method 5 particulate
sample train while sampling for particulates. The cyclone catch is placed in
a desiccated and tare-weighed ceramic crucible. The crucible with sample is
heated in an oven at 230°F to remove its moisture. It is then desiccated to
room temperature and weighed. The crucible with sample is then placed in an
electric muffle furnace maintained at a temperature of 1400°F until ignition
is complete and the sample has reached a constant weight. It is cooled in a
desiccator over desiccant and weighed. Combustible content is calculated as
the percent weight loss of the sample based on its post 230°F weight.
At Test Site F the bottom ash samples were collected in several in-
crements from the grate during testing. These samples were mixed, quartered,
and sent to Commercial Testing and Engineering Company for combustible
determination. Multiclone ash samples were taken from ports near the base of
the multiclone hopper. This sample, approximately two quarts in size, was
sent to Commercial Testing and Engineering Company for combustible determination.
4.7 BOILER EFFICIENCY EVALUATION
Boiler efficiency is calculated using the ASME Test Form for Abbre-
viated Efficiency Test, Revised, September, 1965. The general approach to
efficiency evaluation is based on the assessment of combustion losses. These
losses can be grouped into three major categories: stack gas losses, com-
31
-------
bustible losses, and radiation losses. The first two groups of losses are
measured directly. The third is estimated from the ABMA Standard Radiation
Loss Chart.
Unlike the ASME test in which combustible losses are lumped into
one category, combustible losses are calculated and reported separately for
combustibles in the bottom ash, combustibles in the mechanically collected ash
which is not reinjected, and combustibles in the flyash leaving the mechanical
collector.
4.8 TRACE SPECIES MEASUREMENT
The EPA (IERL-RTP) has developed the Source Assessment Sampling
System (SASS) train for the collection of particulate and volatile matter
in addition to gaseous samples (Figure 4-5). The "catch" from the SASS
train is analyzed for polynuclear aromatic hydrocarbons (PAH) and inorganic
trace elements.
In this system, a stainless steel heated probe is connected to an
oven module containing three cyclones and a filter, size fractionation is
accomplished in the series cyclone portion of the SASS train, which incor-
porates the cyclones in series to provide large quantities of particulate
matter which are classified by size into three ranges:
A) >10 ym B) 3 ym to 10 ym c) 1 ym to 3 ym
Together with a filter, a fourth cut (>1 ym) is obtained. Volatile organic
material is collected in an XAD-2 sorbent trap. The XAD-2 trap is an integral
part of the gas treatment system which follows the oven containing the cyclone
system. The gas treatment system is composed of four primary components:
the gas conditioner, the XAD-2 organic sorbent trap, the aqueous condensate
collector, and a temperature controller. The XAD-2 sorbent is a porous polymer
resin with the capability of absorbing a broad range of organic species.
Some trapping of volatile inorganic species is also anticipated as a result
of simple impaction. Volatile inorganic elements are collected in a series
of impingers. The pumping capacity is supplied by two 10 cfm high volume
vacuum pumps, while required pressure, temperature, power and flow conditions
are obtained from a main controller.
32
-------
U)
U)
Stack T.C.
Convection
oven
Filter
Gas cooler
w H u
Stack velocity (AP)
magnehellc gauges
Orifice 6H,
nagnehellc gauqe
Sorbent
cartridge
Gas
meter
T.C.
/* Condennte
-ytX /'"collector
imp/cooler
trace element
col lector
Coarse adjustment
Fine valve
adjustment
<< valve 9'
V\rC*>
Vacuum pumps
Dry test meter
'9«r^.
Imp In
T.C.
Vacuum
gage
FIGURE 4-5. Source Assessment Sampling (SASS) Flow Diagram
-------
5.0 TEST RESULTS AND OBSERVATIONS
This Section presents the results of tests performed on Boiler F.
Observations are made regarding the influence on efficiency and on gaseous
and particulate emissions as the control parameters were varied. Thirty-
five defined tests were conducted over a two-month test period to develop
this data. Reference should be made to Table 2-1 in the Executive Summary
and to Tables 5-31 through 5-34 at the end of this section when reading
through the following discussion.
5.1 OVERFIRE AIR
Boiler F had a standard overfire air configuration consisting of
two rows of air jets on the rear water wall and two rows on the front water
wall, the lower front row of air jets being an integral part of the coal
spreaders. Air flow to each row of overfire air jets could be controlled
to a certain extent by a system of butterfly valves. Static pressure in
each overfire air header was used as a measure of relative air flow.
A series of tests were run in which overfire air pressure (and thus
overfire air flow) was the independent variable. Emissions and efficiency
were measured as the overfire air pressures were varied to determine which
overfire air settings were optimum in terms of emissions and boiler efficiency.
The test results are presented in Table 5-1 and discussed in the following
paragraphs. These tests indicated that baseline and maximum overfire air
conditions gave somewhat better results than low overfire air condition.
There was no clear indication whether the baseline condition, which
put most of the overfire air through the front wall, was any better or worse
than the maximum overfire air condition which increased the overfire air flow
through the rear wall. However, for the purposes of this test program, the
maximum overfire air condition was selected as the optimum condition and used
in several subsequent tests.
35
-------
TABLE 5-1
EFFECT OF OVERFIRE AIR ON EMISSIONS AND EFFICIENCY
TEST SITE F
Test No.
Description
OVERFIRE AIR CONDITIONS
Front Upper, "HaO
Front Lower, "H2O
Rear Upper, "H20
Rear Lower, "HjO
FIRING CONDITIONS
Load, % of capacity
Grate Heat Release, lO^Btu/hr-ft2
Coal
Coal Fines, % Passing 1/4"
Excess Air, %
ECONOMIZER OUTLET EMISSIONS
Participate Loading, lbs/106Btu
Combustible Loading, U>s/106Btu
Inorganic Ash Loading, Ibs/lO^Btu
Combustibles in Flyash, %
02, » (dry)
CO, ppm (dry) @ 3% 02
NO, Ibs/lO^tu
HC, ppm (dry) @ 3% 02
Opacity, %
MULTICLONE OUTLET EMISSIONS
Particulate loading, Ibs/lO^tu
Combustible Loading, lbs/106Btu
Inorganic Ash Loading, lbs/106Btu
Combustibles in Flyash, %
Multiclone Collection Efficiency, %
HEAT LOSSES, %
Dry Gas
Moisture in Fuel
H2O from Combustion of Hj
Combustibles in Flyash
Combustibles in Bottom Ash
Radiation
Unmeasured
Total Losses
Boiler Efficiency
16A
Base-
line
13.2
9.9
1.3
5.3
100
668
Penn A
54
7.6
228
OOS
13
2.5
__
16B
Max
OFA
11.1
10.0
4.4
8.3
100
668
Penn A
50
7.2
163
OOS
13
2.5
__
~
16C
LOW
OFA
5.2
6.6
2.7
2.8
100
668
Penn A
63
~
-
8.3
378
OOS
0
4.8
__
~
17
Base-
line
13.6
10.3
1.0
5.3
99
659
Penn A
24
45
5.51
3.86
1.65
70.1
6.7
382
OOS
9
3.9
1.13
0.51
0.62
45.0
79.5
7.78
0.47
3.75
5.50
1.70
0.52
1.50
21.22
78.78
18
Max
OFA
10.8
10.2
4.8
8.2
99
648
Penn A-
16
34
6.14
4.38
1.75
71.4
5.5
429
0.358
5
0.77
0.32
0.45
41.3
87.4
7.07
0.52
3.89
6.24
1.04
0.52
1.50
20.78
79.22
19
Low
OFA
4.9
6.9
2.4
2.8
99
665
Penn A
31
37
8.79
6.32
2.47
71.9
5.9
607
0.421
16
4.2
1.26
0.58
0.68
46.1
85.7
8.48
0.74
3.96
9.00
1.46
0.52
1.50
25.66
74.34
OOS - Analyzer Out-of-Service
36
-------
5.1.1 Particulate Loading vs Overfire Air
Particulate loading was lowest when the overfire air pressure was
high, as it was in the baseline and maximum overfire air tests. The
particulate vs overfire air test data are shown in Table 5-2.
TABLE 5-2
PARTICULATE LOADING VS OVERFIRE AIR
Economizer Outlet Multiclone Outlet
Test Particulate Particulate
No. Overfire Air lbs/106 Btu lbs/106 Btu
17 Baseline 5.51 1.13
18 High 6.14 0.77
19 Low 8.79 1.26
The lowest economizer outlet particulate loading occurred under
baseline conditions (Test 17) when the overfire air pressures were very high
in the front and lower in the rear. After the multiclone dust collector,
the lowest particulate loading occurred under the maximum overfire air
conditions (Test 18) in which the air flow to the rear jets was increased.
Low overfire air pressures produced significantly higher particulate loadings
at both the economizer outlet and the multiclone outlet.
The combustible content of the economizer outlet flyash from
Tests 17, 18 and 19 was basically constant at 70.1%, 71.4% and 71.9%, respectively.
Therefore, it cannot be said that high overfire air decreased the percent com-
bustibles in the flyash. However, high overfire air did produce the lowest
particulate loadings and it is concluded that high overfire air in either the
baseline or maximum configuration is the desirable mode pf operation on this
unit.
5.1.2 Nitric Oxide vs Overfire Air
The nitric oxide (NO) data from Tests 18 and 19 indicate that high
overfire air pressure reduces this emission. However, it must be kept in mind
that the evidence is limited to only two data points and is, therefore, rather
37
-------
weak. When a correction is made for the effect of oxygen on nitric oxide
levels (NO increases 0.051 lbs/106 Btu for each 1% O2 increase, Figure 5-10),
the reduction in nitric oxide due solely to increased overfire air pressure
is only 11%. This reduction is not very significant. The test data are pre-
sented in Table 5-3.
TABLE 5-3
NITRIC OXIDE VS OVERFIRE AIR
Test
No.
18
19
Measured
Nitric Oxide
Overfire Air % 0^ lbs/106 Btu
High
Low
5.5 0.358
5.9 0.421
Nitric Oxide
Corrected to 5 .5% 02
lbs/106 Btu
0.358
0.401
5.1.3 Carbon Monoxide and Unburned Hydrocarbons vs Overfire Air
Carbon monoxide (CO) was lowest at high overfire air settings. Un-
burned hydrocarbons (HC) gave mixed results. It is concluded from this data
that the two high overfire air pressure tests had the highest combustion
efficiency. The only discrepancy was the zero HC measurement during low
overfire air, Test 16C. The test data are given in Table 5-4.
TABLE 5-4
CARBON MONOXIDE AND HYDROCARBONS VS OVERFIRE AIR
Test
No.
16A
16B
16C
17
18
19
Overfire Air
Baseline
High
Low
Baseline
High
Low
Carbon Monoxide
ppm @ 3% 0-? (dry)
228
163
378
382
429
607
Unburned Hydrocarbons
ppm @ 3% 02 (wet)
13
13
0
9
5
16
38
-------
5.1.4 Boiler Efficiency vs Overfire Air
Boiler efficiency was more than four percent higher during the base-
line and maximum overfire air tests than it was during the low overfire air
test. Three percent of this increase comes directly from reduced combustible
losses in the flyash and may be attributed to the increase in overfire air
induced turbulence. The remaining one percent difference in efficiency appears
in the dry gas loss and loss due to moisture in fuel categories. These two
losses are unrelated to the overfire air conditions. The heat losses for the
overfire air tests are shown in Table 5-1 and summarized in Table 5-5.
TABLE 5-5
BOILER EFFICIENCY VS OVERFIRE AIR
Test
No.
17
18
19
Overfire Air
Baseline
High
Low
Heat Loss Due to
Comb in Flyash, %
5.50
6.24
9.00
Boiler
Efficiency, %
78.78
79.22
74.34
5.2 FLYASH REINJECTION
Boiler F does not reinject flyash from the mechanical dust collector.
However, it does reinject flyash pneumatically and continuously from the
economizer hopper and from the boiler hopper. During one test, Test 23, the
flyash collecting in the economizer hopper was diverted to barrels rather
than reinjected. This resulted in a 5%-27% drop (depending on which test you
compare it to) in particulate mass loading at the economizer outlet when com-
pared to the full reinjection test data. The data also indicate that during
Test 23, ten percent of the flyash entering the economizer was collected in
the economizer flyash hopper. This test will be described in more detail below.
It is important to remember that at this site particulates were
sampled after the economizer and not at the boiler outlet, as at the other
sites. This sampling location was chosen because physical limitations prevented
particulate sampling upstream of the economizer. Test 23, during which the rate
39
-------
of flyash collection in the economizer hopper was measured, provides some
indications, however, of the "collection efficiency" of the economizer and,
hence, a factor that can be used to correct for the location of the particu-
late sampling plane when comparing particulate data from this site with
particulate data from other sites.
5.2.1 Reduced Flyash Reinjection, Test No. 23
During Test 23, flyash reinjection from the economizer hopper was
stopped completely for 7-1/2 hours. This was accomplished by closing the
reinjection air dampers and by closing gate valves on the economizer hopper
discharge lines. The economizer ash collection rate was also measured by
diverting the ash to tare weighed barrels. This rate measurement was made
during the last two hours of the test and is presented in Table 5-6.
TABLE 5-6
ECONOMIZER ASH COLLECTION RATE
TEST NO. 23 - TEST SITE F
Location Tare Wt. Final Wt. A Wt.
Right Hopper
Center Hopper
Left Hopper
Total Sample Collected 116.5 lb.
Stop Time
Start Time
Sampling Time 2:10 = 2.167 hours
Sample Collection Rate = 116.5 _. ,,
2067 - 54 lb/hr
Particulate mass loading at economizer outlet = 507 lb/hr (measured)
Particulate mass loading at boiler outlet = 507+59 lb/hr = 561 lb/hr
(calculated)
36.5 lb.
50.0 lb.
41.0 lb.
46.0 lb.
129.0 lb.
69.0 lb.
9.5 lb.
79.0 lb.
28.0 lb.
Percent flyash collected by economizer = 10%
40
-------
Based on the data from Test 23 it may be assumed that the
particulate loadings at the boiler outlet are about ten percent higher than
the loadings at the economizer outlet for all tests.
5.2.2 Particulate Loadings vs Flyash Reinjection
The reduced flyash reinjection test gave the lowest economizer
outlet particulate loading of all seven particulate tests at full load.
This result would be expected since past experience has shown that a sig-
nificant fraction of the reinjected flyash is reentrained in the flue gas
stream.
The magnitude of the reduction was not well established due to the
difficulty of controlling other parameters and because only a single reduced
reinjection test was run. As shown in Table 5-7, the magnitude of the re-
duction in particulate loading was in the range of 5% to 27%.
TABLE 5-7
PARTICULATE LOADING VS FLYASH REINJECTION
Test
No.
23
17
15
18 "
24
Flyash
Reinj
No
Yes
Yes
Yes
Yes
Test Conditions
% Load
100
99
99
99
102
% O?
6.3
6.7
7.8
5.5
5.0
OFA
High
Norm
Norm
High
High
Economizer Outlet
Particulate Loading
lbs/106 Btu
5.24
5.51
5.93
6.14
7.18
% by Which Test
23 Particulate
Loading is Lower
5%
12%
15%
27%
100% load = unit's design capacity of 80,000 Ib stm/hr.
41
-------
5.2.3 Boiler Efficiency vs Flyash Reinjection
Test 23 showed that the economizer was collecting flyash at the rate
of 54 pounds per hour while the boiler was at its design capacity of
80,000 pounds per hour of steam. The boiler hopper flyash contained 70.53%
combustible matter by weight. Translated into heating units, the economizer
hopper flyash represents 0.6% of the heat input to the boiler. Therefore
maximum potential efficiency gain resulting from economizer ash reinjection
is 0.6% (based on Test 23 data). The actual efficiency gain would be some-
what less since some of the reinjected flyash is reentrained in the flue
gas stream and not collected or combusted the second time around.
5.3 EXCESS OXYGEN AND GRATE HEAT RELEASE
The boiler at Test Site P was tested for emissions and boiler
efficiency at three boiler loadings representing 100%, 75% and 50% of de-
sign steaming capacity. At each load the boiler was tested over a wide
range of excess air conditions. This section profiles the various emissions
and the boiler efficiencies as a function of these two variables.
Boiler steam loading is expressed in terms of grate heat release.
At full load, the measured grate heat release on this unit was about 670,000
Btu/hr-ft2. Excess air is expressed in termr of percent oxygen in the flue
gas.
5.3.1 Excess Oxygen Operating Levels
Figure 5-1 depicts the various conditions of grate heat release and
excess oxygen under which tests were run on the boiler at Site F. Different
symbols are used to distinguish between the two coals fired.
Full design capacity was easily met on this unit without any signifi-
cant deterioration in combustion efficiency. At full capacity the unit was
operated at oxygen levels as low as 5% (30% excess air) without problems for
periods of up to 7.5 hours. Five percent O^ ^s considered very good for a
stoker boiler and meets the manufacturer's design performance of 30% excess
42
-------
O
O
CNJ
s °.
m O
I-
LU
CC O
LU O
°~ OO
O
O
CO
X
o
50% Capacity
75% Capacity
100% Capacity
0
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
: PQU R
: PENH B
FIG. 5-1
OXYGEN
TEST SITE F
VS. GRflTE HEflT RELEflSE
This Plot Shows the Range in Oxygen Level Under Which
Tests were Conducted
43
-------
air. Long term tests greater than 7.5 hours were not attempted because
such testing is outside the scope of this program.
5.3.2 Particulate Loading vs Grate Heat Release
Figure 5-2 profiles the particulate loading at the economizer outlet
as a function of grate heat release. Different symbols are used for the two
coals fired, and the solid symbol represents the reduced reinjection Test 23.
Boiler outlet particulate loadings were not measured because boiler geometry
prevented it. However, it was determined, as is described in Section 5.2,
that particulate loadings were about ten percent higher at the boiler out-
let than at the economizer outlet.
The shaded area of Figure 5-2 encompasses the particulate data ob-
tained under what could be called normal operating conditions. It shows a
general increase in particulates with load above 500,000 Btu/hr-ft2 grate
heat release. At full load (670,000 Btu/hr-ft2) the particulate mass loading
under normal operating conditions ranged between 5.5 lbs/10 Btu and 7.2
lbs/106 Btu. At 75% load (500,000 Btu/hr-ft2) the particulate mass loading
ranged between 4.0 and 5.6 lbs/106 Btu.
The average ash carryover was 24% in those tests run under normal
firing conditions. Ash carryover did not vary significantly between the
two coals. Table 5-8 shows the basis for this determination.
TABLE 5-8
ASH CARRYOVER VS COAL TYPE
TEST SITE F
Average Ash Average Ash
Content of Coal Content of Flyash Average Ash
Coal lbs/106 Btu lbs/106 Btu Carryover, %
Penn A 7.97 1.97 24.7
Penn B 6.59 1.46 22.2
44
-------
o
o
CD
O
GO
CD O
_l O
CD
CC
CC
Q_
'CC
UJ
o
CJ
LU
0
Low Overfire Air
^v
t
Reduced
Flyash
Re injection
300.0 400.0
500.0 600.0
700.0
GRRTE HEflT RELERSE 1000 BTU/HR-SQ FT
O : PENN « A
FIG. 5-2
ECONOMIZER OUT PRRT. VS. GRRTE HERT RELERSE
TEST SITE F
Shaded Area Encompasses Data Obtained Under Normal
Operating Conditions
45
-------
Particulate loadings were measured at the dust collector outlet
simultaneously with measurements made at the economizer outlet for nine of
the eleven particulate tests. These data are plotted against grate heat
release in Figure 5-3. Different symbols are used for each coal and flyash
reinjection configuration.
Particulate loadings at the dust collector outlet averaged 1.13 Ibs/
106 Btu and ranged in value from a low of 0.77 lbs/10 Btu to a high of 1.39
lbs/106 Btu. Mechanical dust collector efficiency averaged 81% and will
be discussed further in Section 5.6.
5.3.3 Stack Opacity vs Grate Heat Release
Stack opacity was measured during several tests by a transmissometer.
The transmissometer's calibration was not checked and, therefore, absolute
values may not be reliable. However, relative values, as test variables
were varied, are of interest. Figure 5-4 plots opacity versus grate heat
release and shows that opacity did not rise very much at full load. This is
one of several indications that combustion efficiency did not deteriorate at
full load.
5.3.4 Nitric Oxide vs Oxygen and Grate Heat Release
Nitric oxide (NO) and nitrogen dioxide (NC>2) concentrations were
measured during each test in units of parts per million (ppm) by volume. A
chemiluminescent NOx analyzer was used to make these measurements. The
ppm units have been converted to units of lbs/10° Btu in this report so they
can be more easily compared with existing and proposed emission standards.
Table 2-1 in the Executive Summary lists the nitric oxide data in units of
ppm for the convenience of those who prefer these units.
Nitric oxide concentrations are known to increase with load at
constant excess air, and to increase with excess air at constant load. These
two factors often cancel themselves out in normal boiler operation because
excess air usually decreases as load increases. Such was the case with
Boiler F.
46
-------
o
o
in
CO
o
C\J _
CD O
-1 S
o
o
(D
CC
cr
o_
o
-LLJ
o
^ o
I CO
Low Over-
fire Air
V
\
Reduced
Flyash
Reinjection
0
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
PENH fl
FIG. 5-3
MULTICLONE OUT PflRT.
TEST SITE F
VS. GRRTE HERT RELERSE
47
-------
o
o
o
o
CO
UJ
cc o
LU O
Q_
CD
O
o
0_
o
-H-
-I 1 1 1 I
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
0
PENN R
FIG. 5-4
OPflCITY
TEST SITE F
VS. GRflTE HEflT RELEflSE
48
-------
Figure 5-5 presents the nitric oxide data as a function of grate
heat release under the various excess air conditions encountered during
testing. The nitric oxide emissions are stable over all loads. Table 5-9
illustrates this independence of load under normal operating excess air.
TABLE 5-9
NITRIC OXIDE VS LOAD AT NORMAL EXCESS AIR
Nitric Oxide Nitric Oxide
100% Load
75% Load
50% Load
lb/106 Btu
0.429io.068
0.473±0.086
0. 447±0. 108
ppm @ 3% 05
sieiso
347±63
328±79
Figure 5-6 presents the nitric oxide data as a function of oxygen
in the flue gas at three grate heat release ranges. In this figure, the
effects of boiler load and excess air are separated and both become evident.
The nitric oxide data in each grate heat release range (load range)
are plotted versus oxygen on an expanded scale in Figures 5-7, 5-8 and 5-9.
In each of these plots a trend line was determined by linear regression
analysis. The three trend lines are combined in Figure 5-10 to form a nitric
oxide trend line plot which could be used for predicting nitric oxide con-
centrations on the unit. The slope of these trend lines indicates that
nitric oxide increases by 0.051 lbs/10^ Btu for each one percent increase in
oxygen.
Nitrogen dioxide (N02) was also measured at this test site. At the
economizer outlet, N02 averaged 0.005 lbs/106 Btu (4 ppm). Concentrations
this small are very difficult to measure accurately with the chemiluminescent
NOx analyzer and could be in error by as much as 100%. The nitrogen dioxide
(N02) data are presented in Figure 5-11 as a function of grate heat release,
and in Figure 5-12 as a function of oxygen for three grate heat release
ranges. There is evidence in Figure 5-12 that NO2 increases with increasing
O2 at the lower loads.
49
-------
00
o
o
o
o
o
\ o
CD O
I CD
O
O
X
O
0 8
A
A
0
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
: PENNR
FIG. 5-5
NITRIC OXIDE
TEST SITE F
VS. GRflTE HERT RELEflSE
50
-------
CD
O
O
O
O
O
CO _|
^ O
CO O
_J CD-J
o
o
LU *I
a
>i
X
o
o °
H^ O
DC -
0
*
A
4.00
OXYGEN
o
+
6.00
8.00 10.00 12.00
PERCENT, DRY
O : 300-399GHR -f- ! 500-599GHR
FIG. 5-6
NITRIC OXIDE
TEST SITE F
I 600-699O*
VS. OXYGEN
51
-------
O
a
o
o_
c*-
o
CD
v. o
CD O
_J CD-
in
o
o
X
o
0 o
100% Capacity
Penn A Coal
Penn B Coal
f !
4.00
OXYGEN
FIG. 5-7
NITRIC OXIDE
TEST SITE F
-1 1 -i
8.00 10.00 12.00
PERCENT, DRY
0
6.00
VS. OXYGEN
Linear Degression Applied by Method of. Least Squares
Coefficient of Determination =0.83
Slope » 0.051 IDS NO/106 Btu per 1% O2
52
-------
o
o
o
\ O
CD O
_J O
in
o
o
a
o
i i
X
o
0
75% Capacity
~T Perm A Coal
.1. Perm B Coal
4.00
OXYGEN
FIG. 5-8
NITRIC OXIDE
TEST SITE F
6.00
8.00 10.00 12.00
PERCENT, DRY
: 500-599GHR
VS. OXYGEN
Linear Regression Applied by Method of Least Squares
Coefficient of Determination = 0.82
Slope = 0.053 Ibs NO/106 Btu per 1% 02
53
-------
o
o
o
o
z o
o °
S CD
"v O
CD O
_J O
in
o
o
X
o
0 8
s
DC O.
i_ CO
50% Capacity
-rr 1
4.00
OXYGEN
Q:aOD-3MGHR
FIG. 5-9
NITRIC OXIDE
TEST SITE F
6.00
8.00 10.00
PERCENT. DRY
I
12.00
VS. OXYGEN
Linear Regression Applied by Method of Least Squares
Coefficient of Determination =0.98
Slope * 0.050 Ibs NO/106 Btu per 1% 02
54
-------
CD
o
o
o
o
o
GO -I
*N. O
CD O
_J OD
o
o
LU
O
ii
X
o
o
o
oc INI -
0
/ / i
4.00
OXYGEN
O : NOX TRENDS
FIG. 5-10
NITRIC OXIDE
TEST SITE F
6.00 8.00 10.00
PERCENT, DRY
12.00
VS. OXYGEN
55
-------
O
s
O
CO
CD T|- _
O
(M
CD _
O
LU O
x: "^
o
i i
o
o
LU §
O .
O
CC
0
A©
A O
A O
T
T
T
300.0 400.0 500.0 600.0 700.0
GRflTE HERT RELERSE 1000 BTU/HR-SQ FT
: PENN n
FIG. 5-11
NITROGEN DIOXIDE
TEST SITE F
VS. GRRTE HEflT RELERSE
56
-------
8
O
CO
ID o
I O
CD -r_l
"Z. (\J
-1 o
^ o
= CO
CD '
Q CSJ-
X ^
o
II
o
o
z o
UJ CO
o .
o
oc
0
AA
A A +
A A +
A Af- A
A A___* J
4.00 6.00 8.00 10.00
OXYGEN PERCENT, DRY
0 ; 300-399GHR + : 50Q-599GHR A ' 600-699GHR
FIG. 5-12
NITROGEN DIOXIDE VS. OXYGEN
TEST SITE F
12.00
57
-------
5.3.5 Sulfur Oxides vs Fuel Sulfur
Sulfur dioxide (SO2) was measured during each test using an NDIR type
continuous monitor. Sulfur trioxide (803) was measured once while firing
each of the two coals using a wet chemical method called the Goksoyr-Ross
method. The test data and their significance are discussed in this section.
Sulfur dioxide (SC>2) concentrations are directly related to the sulfur
content of the fuel. SO2 was not observed to vary with load or O2. The
small fraction of fuel sulfur which is not converted to SO2 is either retained
in the ash or converted to SO3 and other sulfur compounds. As a check on
this relationship and on the validity of the data, the measured sulfur dioxide
concentration was plotted against fuel sulfur in Figure 5-13. The diagonal
line represents 100% conversion of fuel sulfur to S02.
Ash samples taken during two tests indicate that 4% of the fuel
sulfur was retained in the ash. Assuming 96% conversion of fuel sulfur to
S02 for all tests, the average error in the measurement technique was 7%.
This is not out of line with expected performance of the instruments and
techniques. Some of the sulfur oxides data could not be associated with a
coal sample and were, therefore, not included in this determination.
Figure 5-14 presents all of the SO2 measurements made at Site F as a
function of grate heat release. A wide variation in SO2 concentration is
seen on the primary coal, Penn A. It can be shown that these variations are
due primarily to variations in fuel sulfur and only secondary to measurement
error.
The sulfur trioxide (803) test data are presented in Table 5-10.
Because the data are limited to two data points, no discussion or conclusions
will be attempted.
58
-------
O
O
LO
o
o
OJ
CD O
UJ O
o o -
H1 '*
X ^-i
o
a
100% Conversion of
Fuel Sulfur to SO2
0
.500 1.000 1.500 2.000 2.500
FUEL SULFUR RS S02 LB/MILLION BTU
:PENN R
: PENMB
FIG. 5-13
SULFUR DIOXIDE
TEST SITE F
VS. FUEL SULFUR RS S02
59
-------
CD
o
o
LD
(NJ
O
O
\ o
CD O
_i in
§ §
CL IT)
0
300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
:PQM
; FCNN8
FIG. 5-14
SULFUR DIOXIDE
TEST SITE F
VS. GRflTE HEflT RELEflSE
60
-------
TABLE 5-10
SULFUR TRIOXIDE TEST DATA
Test
No.
22
30
Coal
Penn A
Penn B
Test Conditions
% Load
99
97
% 0?
6.0
6.8
OFA
High
High
SOx
ppm@ 3% 03
SO 9
1126
695
SO^
0
22
5.3.6 Hydrocarbons vs Oxygen and Grate Heat Release
Unburned hydrocarbons (HC) were measured with a heated sample line
and a continuous monitoring instrument utilizing the flame ionization method
of detection. Test data are plotted as a function of grate heat release in
Figure 5-15, and as a function of oxygen in Figure 5-16.
There is some indication that the concentration of hydrocarbons in
the flue gas may be load dependent. No hydrocarbons were measured at 50%
load, while 75% load and 100% load tests showed measurable concentrations.
The data averaged by load are given in Table 5-11.
TABLE 5-11
HYDROCARBON VS BOILER LOAD
No. of Measurements Average HC, ppm
100% Load
75% Load
50% Load
15
10
5
7.616.3
14.8±8.3
0.0
It is also noteworthy that measured hydrocarbon concentrations at
full load were zero above 8% 02 but measurable below 8% 02- This trend,
shown in Figure 5-16, did not hold true at 75% load.
61
-------
8°
'
LU
<_>
£
Q_
8
cr
z: o
o_ o
CL_ -
LO
o
o
__ o
o "
QQ
cc
58
O °
g in'
A
A
O Q
Q
300.0 400.0 500.0 600.0 ' 700.0
GRRTE HERT RELERSE 1000 BTU/HR-SQ FT
: POM
FIG. 5-15
HYDROCRRBON
TEST SITE F
VS. GRRTE HERT RELERSE
62
-------
o ._
UJ
O
n o
Q_ O
°- in
o
o
o
CD
CC
§
0
4-
+
AA
+
-e-
4.00
OXYGEN
Q : 300-399GHR
FIG. 5-16
HYDROCflRBON
TEST SITE F
6.00
-©T
8.00 10.00
PERCENT, DRY
-Q-
12.00
500-599GHR
" 600-699GHR
VS. OXYGEN
63
-------
5.3.7 Carbon Monoxide vs Oxygen and Grate Heat Release
Carbon monoxide (CO) was measured with an NDIR continuous monitor
in units of parts per million (ppm) by volume. The data are plotted as a
function of grate heat release in Figure 5-17, and as a function of oxygen
in Figure 5-18.
Carbon monoxide concentrations were highest under high load low 02
conditions and under low load high O2 conditions. In between these extremes
the carbon monoxide concentration remained below 400 ppm (0.04%) which is
considered acceptable for a coal-fired stoker boiler.
5.3.8 Combustibles in the Ash vs Oxygen and Grate Heat Release
Flyash samples collected at the economizer outlet and at the multi-
clone dust collector outlet were baked in a high temperature oven for deter-
mination of combustible content. Bottom ash samples were also processed in
this manner. The test data for each of the sample locations are plotted
against grate heat release in Figures 5-19, 5-20, and 5-21. The data are
plotted against oxygen in the flue gas in Figures 5-22, 5-23 and 5-24.
In general, the combustible fractions in the various ashes did not
vary as functions of either grate heat release or oxygen. Although the data
are limited, they are seen to remain relatively constant. The one exception
is the economizer outlet sample taken at low load (363 GHR) and high C>2
(9.4%). This sample contained only 50% combustibles compared to the average
69% combustible content for the other economizer outlet flyash samples.
Average combustible content for the three sample locations were
66.6^7.6% at the economizer outlet, 46.5-3.2% at the dust collector outlet,
and 12.4±5.2% in the bottom ash.
5.3.9 Boiler Efficiency vs Grate Heat Release
Boiler efficiency was determined using the ASNE heat loss method for
all tests which included a particulate mass loading determination. The test
data, plotted in Figure 5-25, shows a general decrease in efficiency as grate
heat release increases. The reason for this decrease in efficiency is best
illustrated in Table 5-12.
64
-------
-------
LU
O
£ o
"- d
<"§
n o
Q.
"-8
CD
0 .
S O
§ 9
2 °
§ 9-i
A A
A A
A A
JUL
T
4.00
OXYGEN
I 1 1
8.00 10.00 12.00
PERCENT, DRY
6.00
+ :
FIG. 5-18
CPRBON MONOXIDE
TEST SITE F
A:
VS. OXYGEN
66
-------
o
o
O
00
UJ O
o
. (D
CD
O
5 o
o ?
cc
UJ
§ o
o
CJ
UJ
0 300.0 400.0 500.0 600.0 700.0
GRRTE HERT RELERSE 1000 BTU/HR-SQFT
0: poti B A :
FIG. 5-19
ECONOMIZER OUT COMB. VS. GRRTE HERT RELERSE
TEST SITE F
67
-------
o
o
o
00
LU
CJ
cc
LU
Q_
O
CD
CD
z:
o
o
ll
LU
O
d o
P o
i CM
7V-
0
300.0 400.0 500.0 600.0 700.0
GRflTE HERT RELERSE 1000 BTU/HR-SQFT
PBMR
FIG. 5-20
MULT I CLONE OUT COMB.
TEST SITE F
VS. GRflTE HERT RELERSE
68
-------
o
CD
O
o
CO
LU
CO
O-
Osl
o
00
O
0
T7 1 1 1 1 1
300.0 400.0 500.0 600.0 700.0
GRflTE HERT RELEflSE 1000 BTU/HR-SQFT
: PENN
FIG. 5-21
BOTTOM RSH COMB.
TEST SITE F
VS. GRflTE HERT RELERSE
69
-------
O
O
O
h- 00
LU
CJ
CC
LU O
Q_ -
O
CO
GO
O
CJ
35
01
LU
2 CD
O
CJ
LU
AA
1 1 1
8.00 10.00 12.00
PERCENT, DRY
:eOO-699GHR
VS. OXYGEN
0
4.00
OXYGEN
300-399Q*
6.00
; 5QO-599GHR
FIG. 5-22
ECONOMIZER OUT COMB.
TEST SITE F
70
-------
o
o
o
o
LU
O
- o
. CO
GO
z:
o
CJ
O
o
(\J
A A
A
0
4.00 6.00 8.00 10.00 12.00
OXYGEN
PERCENT, DRY
: 300-3990* 4- : soo-ssgow A : eco-esscm
FIG. 5-23
MULTICLONE OUT COMB.
TEST SITE F
VS. OXYGEN
71
-------
CD-
CD
O
00
LU
O
CC O
LU
Q_ O
CO
CD o
s?
en
CE
C\J
O
CO
0
vi
4.00
OXYGEN
; 300-99GHR
6.00
; 500-599GHR
FIG. 5-24
BOTTOM flSH COMB.
TEST SITE F
, j
8.00 10.00
PERCENT, DRY
^ : 600-699GHR
VS. OXYGEN
12.00
72
-------
LU
o
o
LO
00
O
O
O
00
o
o
in
t>
LU O
*-*
CJ O
itl
CD
Reduced
Flyash Reinjection
\
Low Overfire Air
-t+
1 - 1
300.0 400.0
1
T
0
500.0 600.0 700.0
GRRTE HERT RELEflSE 1000 BTU/HR-SQ FT
: PEHN B
A: PENNB
FIG. 5-25
BOILER EFFICIENCY
TEST SITE F
VS. GRflTE HERT RELEflSE
73
-------
TABLE 5-12
BOILER EFFICIENCY VS LOAD
Average Heat Losses
100% Load
75% Load
50% Load
Dry Gas
7.8
8.5
7.5
Combustibles
7.9
5.2
4.5
Radiation
0.5
0.7
0.9
Other
5.7
5.3
5.6
Boiler
Efficiency
78.1
80.3
81.5
This Table shows that combustibles played a major roll in deter-
mining boiler efficiency. The increase in combustible heat loss with load
accounts for the decrease in boiler efficiency.
Boiler efficiency heat loss parameters and calculations are compared
to the manufacturers predicted performance data in Tables 5-13 and 5-14.
Data from a 1977 boiler acceptance test are also included. In comparing these
tests, the only real discrepancy was found in the combustible heat loss
category.
Combustible heat losses measured in this program were 3 to 4% higher
than those measured and predicted earlier. It is suspected that the heat
loss was calculated differently in this test program than it was in the
acceptance test or by the boiler manufacturer. To help clarify the issue,
the data and assumptions used to calculate combustible loss for Tests 24 and
29 are given in Table 5-15. The heat losses in Table 5-13 are not adjusted
to the design coal.
74
-------
TABLE 5-13
PREDICTED VS MEASURED HEAT LOSSES
Dry Moisture H20 From Total BOILER
Gas in Fuel H2 in Fuel Combustibles Radiation Unmeasured EFFICIENCY
Mfg. Predicted
Performance 6.33 0.16* 3.63
1977 Acceptance Test 7.60 0.34 4.10
Test 24 - Penn A Coal 6.37 0.31 3.71
Test 29 - Penn B Coal 6.86 0.31 3.68
4.70 0.58
4.23 0.58
8. 33* 0.50
7.18t 0.51
1.50 83.10
1.50 81.65
1.50 79.28
1.50 79.96
* The manufacturer listed a heat loss due to moisture in the air of
0.16%, but did not list a separate heat loss due to moisture in the fuel.
t High combustible heat loss of tests 24 and 29 may be due in part to
method of calculation.
TABLE 5-14
PREDICTED VS MEASURED PERFORMANCE DATA
Steam Flow, Ibs/hr
Fuel Flow, Ibs/hr
Steam Pressure, psig
Steam Temperature, °F
FW to Economizer, °F
Gas Temperature
Leaving Economizer, "F
Excess Air, %
Boiler Efficiency, %
Manufacturers
Predicted
Performance
80,000
7,205
150
Saturated
228
350
30
83.10
Customers
Acceptance
Test, 1977
81,803
8,050
143.8
Saturated
220
377
36.8
81.65
Test 24
Penn A Coal
81,957
7,495
143.0
Saturated
220
370
29.9
79.28
Test 29
Penn B Coal
80,400
6,552
139.7
Saturated
220
373
29.4
79.96
75
-------
TABLE 5-15
CALCULATION OF COMBUSTIBLE HEAT LOSS
Test 24^ Test 29
% Combustible in Flyash (Measured) 67.0 72.6
Lbs flyash/106 Btu Coal (Measured) 7.183 5.944
Btu/lb Combustible (Determined in
Previous Tests) 14,250 14,250
* HEAT LOSS DUE TO COMBUSTIBLES IN FLYASH 6.86% 6.15%
% Combustible in Bottom Ash (Measured) 13.8 13.1
** Lbs Bottom Ash/106 Btu Coal (.Calculated
by Mass Balance) 7.464 5.551
Btu/lb Combustible 14,250 14,250
* HEAT LOSS DOE TO COMBUSTIBLES IN BOTTOM
ASH 1.47% l.Q4%
TOTAL COMBUSTIBLE HEAT LOSS 8.33% 7.19%
* Heat Loss Calculated as Follows:
C-^tlbl. Heat ro.
** Ash in Coal Minus Ash in Flyash = Ash in Bottom Ash, with Appropriate
Corrections for Combustibles:
Lbs Bottom Ash/ _ .% ash in coal. nf)4v .Ibs flyash. % Comb in flvash
106 Btu Coal = ( Btu/lb coalJ ( '~( 10& Btu ' ( -
% Comb in bottom ash.
1 ~ 100 }
76
-------
5.4 COAL PROPERTIES
Two coals were tested in Boiler F. The primary coal is called
Pennsylvania A coal in this report, or Penn A for short. The secondary coal
was specially ordered for this test program. It was a washed and mechanically
treated high grade metallurgical coal. This special coal, called Penn B in
this report, was lower in ash and sulfur than the primary coal.
This section describes coal properties and their impact on emissions
and boiler efficiency. Except for sulfur oxide emissions, the two coals
performed similarly.
5.4.1 Chemical Composition of the Coals
Representative coal samples were obtained from the unit's single
coal scale during each particulate test and SASS test. Each of these coal
samples was given a proximate analysis. In addition, two selected samples
of each coal were given an ultimate analysis, and tested for ash fusion
temperature, Hardgrove grindability index, free swelling index, and mineral
composition of the ash.
The two coals differ primarily in their moisture, ash and sulfur
content. These three coal properties are presented in Table 5-16 on a
heating value basis in order to allow for a more meaningful comparison. This
Table shows that the Pennsylvania B coal was a better coal than Pennsylvania A
in that it was lower in moisture, ash and sulfur.
TABLE 5-16
COAL PROPERTIES CORRECTED TO A CONSTANT 106 BTU BASIS
Penn A Coal Penn B Coal
Moisture, lbs/106 Btu 3.1 2.7
Ash, lbs/106 Btu 8.0 6.6
Sulfur, lbs/106 Btu 1.11 0.74
The individual coal analyses are tabulated in Tables 5-17, 5-18,
and 5-19.
77
-------
TABLE 5-17
FUEL ANALYSIS - PENNSYLVANIA A COAL
TEST SITE F
TEST NO. 05 15 17
PROXIMATE (As Rec)
% Moisture 4.80 5.69 5.26
% Ash 10,80 10.96 9.69
% Volatile 14.03 22.86 23.86
%Fixed Carbon 70.37 60.49 61.19
Btu/lb 13145 12975 13223
% Sulfur 1.34 1.20 1.24
ULTIMATE (As Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oa^gen (Diff)
ASH FUSION (Reducing)
Initial Deformation
Soft (H-W)
Soft (H-1/2W)
Fluid
HARDGROVE GRINDABILITY INDEX
FREE SWELLING INDEX
18 19 20 21 22 23
5.58 7.76 2.26 1.99 3.13 2.28
12.50 11.08 8.43 11.15 9.44 9.45
22.66 22.45 25.22 23.99 23.58 24.20
59.26 58.71 64.09 62.87 63.85 64.07
12649 12501 13813 13347 13627 13750
1.43 1.35 1.61 1.85 1.51 1.66
3.13
76.57
4.69
1.26
0.15
1.51
9.44
3.25
2420
2600
2650
2700+
96
9
23A 24
2.51 3.42
11.01 11.59
23.92 23.32
62.56 61.67
13467 13164
1.67 1.32
3.42
73.70
4.53
1.20
0.14
1 . 32
11.59
4.10
2700+
2700+
2700+
2700+
89
9
AVG
4.
10.
22.
62.
06
55
74
65
STD
DEV
1
1
2
3
13242
1.
3.
75.
4.
1.
0.
1.
10.
3.
92
47
28
14
61
23
15
42
52
68
.5
9
0
0
2
0
0
0
0
1
0
4
.87
.17
.99
.15
85
.21
.21
.03
.11
.04
.01
.13
.52
.60
.95
~ 1
-------
TABLE 5-18
FUEL ANALYSIS - PENNSYLVANIA B COAL
TEST SITE F
Test No.
PROXIMATE (As Rec)
% Moisture
% Ash
% Volatile
% Fixed Carbon
Btu/lb
% Sulfur
ULTIMATE (As Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (Diff)
ASH FUSION (Red)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
29
3.54
8.79
26.10
61.57
13623
1.00
3.54
76.62
4.70
1.15
0.17
1.00
8.79
4.03
2700+
2700+
2700+
2700+
2700+
81
9
30
3.84
9.12
25.39
61.55
13568
0.99
3.84
76.09
4.68
1.09
0.17
0.99
9.12
4.02
2700+
2700+
2700+
2700+
2700+
84
9
AVG
3.69
8.96
25.75
61.61
13596
1.00
3.69
76.36
4.69
1.12
0.17
1.00
8.96
4.03
2700+
2700+
2700+
2700+
2700+
82.5
9
STD
DEV
0.21
0.23
0.50
0.06
39
0.01
0.21
0.37
0.01
0.04
0.01
0.23
0.01
2.12
79
-------
TABLE 5-19
MINERAL ANALYSIS OF COAL ASH
TEST SITE F
00
o
COAL
TEST NO.
Silica, SiO2
Alumina, A12O3
Titania, Ti©2
Ferric Oxide, feO3
Lime , CaO
Magnesia, MgO
Potassium Oxide, ^O
Sodium Oxide , Na2O
Sulfur Trioxide, 803
Phos. Pentoxide, V2°5
Undetermined
Silica Value
Base: Acid Ratio
T250 Temperature
% Pyritic Sulfur
% Sulfate Sulfur
% Organic Sulfur
PENNSYLVANIA A
22
41.47
32.72
1.23
16.23
2.52
0.64
1.59
0.35
2.00
0.82
0.28
68.14
0.28
2575°F
0.83
0.00
0.68
24
48.65
32.14
1.47
10.23
1.93
0.70
2.21
0.23
1.71
0.41
0.17
79.09
0.19
2735
0.52
0.08
0.72
Average
45.06
32.43
1.35
13.23
2.23
0.67
1.90
0.29
1.86
0.62
0.23
73.62
0.24
°F 2655°F
0.68
0.04
0.70
PENNSYLVANIA B
29
47.74
34.17
1.38
9.21
1.32
0.57
1.74
0.37
1.43
0.30
1.55
81.14
0.16
2805°F
0.33
0.00
0.67
30
47.95
32.66
1.46
10.68
1.45
0.74
2.15
0.44
1.38
0.45
0.36
78.84
0.19
2730
0.44
0.00
0.55
Average
47.85
33.42
1.42
9.95
1.39
0.66
1.95
0.41
1.41
0.38
0.96
79.99
0.18
°F 2768°F
0.39
0.00
0.61
-------
5.4.2 Coal Size Consistency
The individual coal samples were screened at the site using 1",
1/2", 1/4", #8 and #16 square mesh screens. The results of these screenings
are presented in Table 5-20. The standard deviation of the coal size con-
sistency for each coal is plotted against the ABMA recommended limits for
spreader stokers in Figures 5-26 and 5-27.
The average size consistencies of the two coals were nearly identi-
cal. It is also evident that the coal size consistency did not vary greatly
from test to test. Therefore, it appears that coal size consistency was not
a variable in these tests. Coal fines, defined as the percent by weight
passing a 1/4" screen, averaged 27% for Penn A coal and 28% for Perm B coal.
5.4.3 Effect of Coal Properties on Emissions and Efficiency
The influence that changing coals from Penn A to Penn B had
on boiler emissions and efficiency is discussed below. Frequent references
are made to figures in Section 5.3, Excess Oxygen and Grate Heat Release,
which illustrate the differences between the two coals.
Excess Oxygen Operating Conditions. The data indicate that Penn A
coal and Penn B coal did not require significantly different excess air
conditions to achieve efficient combustion. Figure 5-1 shows that tests were
run over the same range of oxygen levels for both coals.
Particulate Mass Loading. Both of the coals tested produced
essentially the same particulate mass loadings even though they differed in
ash'and sulfur content. This conclusion is based on examination of the data
in Figure 5-2 and Table 5-21.
Perhaps the best illustration is given in Figure 5-2 where the two
Penn B coal tests are in the midrange of the data from the Penn A coal tests.
The Penn A and B particulate loadings are similar.
Table 5-21 examines the data closer. In this table the two Penn B
tests are compared only with Penn A tests run under similar conditions of load,
oxygen and overfire air. The small differences in particulate loading are not
consistent between loads or sample locations. Therefore, it is concluded that
no significant change in particulate mass loading was measured when the coal
was changed.
81
-------
TABLE 5-20
AS FIRED COAL SIZE CONSISTENCY
TEST SITE F
Test
No.
15
17
18
19
20
21
22
23
23A
24
Penn A
Average
29
30
35
Penn B
Average
PERCENT PASSING STATED SCREEN SIZE
1" 1/2" 1/4" #8 #16
94.8
93.0
93.4
97.6
97.5
97.1
94.2
95.1
96.8
98.5
95.8
97.0
96.0
97.1
96.7
54.9
60.8
48.5
66.4
68.8
66.1
58.9
56.3
68.1
72.8
62.2
56.9
64.6
56.8
59.4
24.6
23.5
16.2
30.5
31.7
24.9
22.8
21.8
32.2
36.7
26.5
28.4
28.4
27.9
28.2
17.3
13.7
10.7
18.7
18.6
15.4
13.7
13.1
18.6
21.4
16.1
16.8
16.8
17.6
17.1
14.7
10.9
9.0
14.2
13.9
12.1
10.9
10.5
13.9
15.7
12.6
11.9
12.3
13.0
12.4
82
-------
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Spreader Stokers
Standard Deviation Limits of Penn A
Coal Size Consistency
FIGURE 5-26.
Size Consistency of "As Fired" Penn A Coal
vs ABMA Recommended Limits of Coal Sizing
for Spreader Stokers - Test Site F
83
-------
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Spreader Stokers
Standard Deviation Limits of
Penn B Coal Size Consistency
FIGURE 5-27.
Size Consistency of "As Fired" Penn B Coal
vs ABMA Recommended Limits of Coal Sizing
for Spreader Stokers - Test Site F
84
-------
TABLE 5-21
EFFECT OF COAL CHANGE ON PARTICULATE LOADING
TEST DESCRIPTION
Perm
Perm
Penn
Penn
Penn
Penn
A
A
B
A
A
B
Coal
Coal
Coal
Coal
Coal
Coal
Test No.
18
24
29
20
21
35
% Load
99
103
101
75
76
76
% O?
5
5
5
8
8
8
.5
.0
.0
.4
.0
.7
OFA
High
High
High
Norm
Norm
Norm
PARTICULATE
Lbs/106 Btu
Econ
6
7
5
4
5
4
Out
.1
.2
.9
.0
.6
.7
D.C.
0
1
1
Out
.8
.0
.4
NA
1
1
.3
.0
Ash Carryover. The percent of the coal ash carried over as flyash
was similar for both coals fired. Ash carryover averaged 24.7% on the Penn A
tests and 22.2% on the Penn B tests. The basis for this determination was
given previously in Table 5-8.
Nitric Oxide. Nitric oxide concentrations may have been slightly
less when firing Penn B coal because its fuel nitrogen content was 11% lower
than that of Penn A. The observed difference is so slight, however, that it
is nearly lost in the normal data scatter. Penn B coal contained 2.71 Ibs/
106 Btu nitrogen, expressed as NO2, compared to Penn A at 3.05 Ibs NO2/106 Btu.
The similarity of nitric oxide concentrations is shown in Figures 5-7 and
5-8.
Sulfur Dioxide. Sulfur dioxide concentrations were directly pro-
portional to the sulfur content of the fuel within measurement accuracies.
This relationship is illustrated in Figure 5-13. A sulfur balance was attempted
for the two tests for which complete sulfur information was available. This
sulfur balance, shown in Table 5-22, is very good within measurement accuracies.
85
-------
For both coals, four percent of the fuel sulfur was retained in the ash while
the remainder was converted to SC>2 and SO3.
TABLE 5-22
SULFUR BALANCE - BOILER F
Penn A (Test 22)
Perm B (Test 30)
Sulfur in
Fuel
Ibs/lO^tu
as SO2
2.22
1.46
Sulfur in
Flue Gas
lbs/106Btu
as SO2
2.19
1.38
Sulfur in
Bottom Ash
Ibs/lO^tu
as SO^
0.01
0.01
Sulfur in
Fly ash
lbs/106Btu
as SOj
0.08
0.05
Hydrocarbons. Unburned hydrocarbon (HC) concentrations were in the
same general range for both coals. Table 5-23 shows the average measured HC
concentrations for both coals at two loads. Although Penn A coal averages
slightly higher than Penn B coal, the difference is not significant due to
the large variations in measured concentrations. Figure 5-15 shows the range
of HC concentration measured.
TABLE 5-23
AVERAGE HYDROCARBON CONCENTRATIONS VS COAL
75% Load
100% Load
Penn A Coal
17
8
Penn B Coal
12
5
Carbon Monoxide. Like the unbumed hydrocarbons, the carbon monoxide
(CO) concentration did not change appreciably with change in coal. Although
the average CO concentrations shown in Table 5-24 indicate that Penn A coal
86
-------
averaged higher CO than Penn B coal, the range of values (Figure 5-17)
indicates that this is not significant. Both coals produced CO within the
same general range of values.
TABLE 5-24
AVERAGE CARBON MONOXIDE CONCENTRATIONS VS COAL
Penn A Coal Penn B Coal
75% Load 149 ± 49 125 ± 51
100% Load 332 ± 148 284 ± 100
Combustibles in the Ash. Percent combustibles in the bottom ash
and in the flyash were similar for both coals. This is illustrated in
Figure 5-19, 5-20, and 5-21. The average combustible data are presented in
Table 5-25.
TABLE 5-25
AVERAGE PERCENT COMBUSTIBLE IN ASH
Penn A Coal Penn B Coal
Economizer Outlet 66 73
Multiclone Outlet 46 48
Bottom Ash 12 12
Boiler Efficiency. Boiler efficiency was not altered by the fuel
change. Moisture related losses were similar because hydrogen and moisture in
the coals were similar. Combustible losses were also similar. Table 5-26
presents the heat losses and boiler efficiency for nearly identical full load
tests in both coals. Penn B coal gave a higher boiler efficiency because of
a lower combustible heat loss. However, there is no evidence indicating that
Penn B coal would consistently have a combustible heat loss that was lower
than Penn A coal.
87
-------
Penn A
(Test
Penn B
(Test
PARTICLE
Coal
24)
Coal
29)
SIZE
7.
7.
1
5
DISTRIBUTION OF
4.0
4.0
FLYASH
TABLE 5-26
BOILER EFFICIENCY VS COAL
BOILER HEAT LOSSES, %
Moisture Combus- BOILER
Dry Gas Related tible Other EFFICIENCY, %
8.3 2.0 78.6
7.2 2.0 79.3
Eleven particle size distribution determinations were made at the
economizer outlet (multiclone dust collector inlet) on Boiler F. These
determinations were made using a Banco classifier, a Brink cascade impactor,
and a SASS cyclone train. Firing conditions for the particle size distri-
bution tests are shown in Table 5-27.
The test results are presented in Table 5-28, and in figures 5-28,
5-29, and 5-30. It is especially important to note the differences in sample
methodologies because each has its drawbacks. A discussion of each method is
included in Section 4.4.
The Bahco classifier sample was collected with a cyclone. As a
result, a fraction of the sample (4 to 9%) was not captured and the results
are biased such that they indicate fewer particles below about 15 micrometers
than there actually were. It is hoped that appropriate corrections can be
made to the Bahco data at some future date using the measured cyclone collection
efficiency (shown in Table 5-28, last column) and the theoretical cyclone
collection efficiencies by particle size.
The Brink and SASS particle size distribution data should be accurate
and require no corrections. However, these are single point measurements,
whereas the Bahco data was obtained with a 24-point traverse of the duct. Single
point samples are suspect for reasons of size stratification within the duct.
88
-------
TABLE 5-27
DESCRIPTION OF PARTICLE SIZE DISTRIBUTION
TESTS AT THE BOILER OUTLET
TEST SITE F
Load
02
OFA
Particle Size Distribution
Methodology Used
5
21
23
24
29
23
23A
24
29
22
30
Penn A
Penn A
Penn A
Penn A
Penn B
Penn A
Penn A
Penn A
Penn B
Penn A
Penn B
54
76
100
102
101
100
99
102
101
99
97
9.4
8.0
6.3
5.0
5.0
6.3
5.9
5.0
5.0
6.0
6.8
Norm
Norm
High
High
High
High
High
High
High
High
High
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Brink Impactor
Brink Impactor
Brink Impactor
Brink Impactor
SASS Cyclones
SASS Cyclones
89
-------
TABLE 5-28
RESULTS OF PARTICLE SIZE DISTRIBUTION
TESTS AT THE BOILER OUTLET
TEST SITE F
Size Distribution
Test Description
Low Load
Med Load
High Load
High Load
High Load
23 High Load
23A High Load
24 High Load
29 High Load
22
30
High Load
High Load
Banco
Bahco
Bah co
Bahco
Bahco
Brink
Brink
Brink
Brink
SASS
SASS
% Below
3 ym
1.8
1.0
1.5
1.2
1.4
2.2
12.5
5.0
6.5
3.4
4.6
% Below
10 ym
8.9
2.4
2.9
2.9
3.5
9.8
12.9
Size Concentration
lbs/10bBtulbs/10bBtu
Below 3 ym Below 10 ym
0.091
0.055
0.079
0.086
0.083
0.115
0.655
0.359
0.386
0.186
0.250
0.452
0.134
0.152
0.208
0.208
0.540
0.707
Sample
Collection
Efficiency
96.2
91.0
94.0
93.8
93.9
100
100
100
100
100
100
90
-------
BAHCO CLASSIFIER
FIGURE 5-28
10 30 100 300
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
Particle Size Distribution at the Economizer Outlet from
Bahco Classifier and Sieve Analysis - Test Site F.
1000
-------
50
H
Ul
2
<
B
20
EH
2
W
Hi
0.1
0.3 1 3
EQUIVALENT PARTICI^E DIAMETER, MICROMETERS
FIGURE 5-29. Particle Size Distribution at the Economizer Outlet
from Brink Cascade Impactor - Test Site F
92
-------
13 10
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
FIGURE 5-30.
Particle Size Distribution at the Economizer Outlet
from SASS Gravimetrics - Test Site F
93
-------
5.6 EFFICIENCY OF MULTICLONE DUST COLLECTOR
The collection efficiency of the multiclone dust collector was
determined in nine tests under various boiler operating conditions. The
data were obtained by measuring the particulate loadings simultaneously at
the inlet and outlet of the dust collector. Test data are presented in
Table 5-29 and plotted as a function of grate heat release in Figure 5-31.
The design: efficiency of the dust collector, as supplied by the
manufacturer, was supposed to be 85% at maximum continuous load. The measured
collection efficiencies agreed well with the design efficiency. At full load
the measured efficiency ranged from 77 to 87% and averaged 82%. At 75%
load the dust collector efficiency averaged 78%.
TABLE 5-29
EFFICIENCY OF DUST COLLECTOR
TEST SITE F
Particulate Loading
lb/106Btu
Test
No.
15
17
18
19
21
23
24
29
35
Coal
Type
Penn A
Perm A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn B
Penn B
Load
%
99
99
99
99
76
100
103
101
76
02
%
7.8
6.7
5.5
5.9
8.0
6.3
5.0
5.0
8.7
Collector
Inlet
5.926
5.510
6.136
8.785
5.567
5.240
7.183
5.944
4.726
Collector
Outlet
1.329
1.130
0.771
1.256
1.262
0.998
1.031
1.392
1.026
AVERAGE
Collector
Efficiency
%
77.6
79.5
87.4
85.7
77.3
81.0
85.6
76.6
78.3
81.0
94
-------
5.7 SOURCE ASSESSMENT SAMPLING SYSTEM (SASS)
Two SASS tests were run at Test Site F, one on each of the two
coals at full load. All SASS test results will be reported under separate
cover at the conclusion of this test program. The SASS sample catches will
be analyzed by combined gas chromatography/mass spectroscopy for total
polynuclear content. In addition, seven specific polynuclear aromatic
hydrocarbons (PAH) will be sought. These are listed in Table 5-30.
TABLE 5-30
POLYNUCLEAR AROMATIC HYDROCARBONS
ANALYZED IN THE SITE F SASS SAMPLE
Element Name
Molecular
Weight
Molecular
Formula
7,12 DimethyIbenz (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
256
278
228
268
252
302
302
267
C20H16
C22H14
C18H12
C20H12
C24H14
95
-------
o
o
o
O)
o
o
o
I- GO
Z
QC O
LU O
Q_
O
CD
Z
O
"
0 300.0 400.0 500.0 600.0 700.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQFT
O:PB§I n A ! ra*8
FIG. 5-31
MULTICLONE EFF. VS. GRflTE HEflT RELEflSE
TEST SITE F
96
-------
5.8 DATA TABLES
Tables 5-31 through 5-34 summarize the test data obtained at
Test Site F. These tables, in conjunction with Table 2-1 in the Executive
Summary, are included for reference purposes.
TABLE 5-31
PARTICULATE EMISSIONS
TEST SITE F
EH
W
EH
8
B;
w
H
O
m
Test
No
05
15
17
18
19
20
21
23
24
29
35
Coal
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn B
Penn B
Load
54
99
99
99
99
75
76
100
103
101
76
°%2
9.4
7.8
6.7
5.5
5.9
8.4
8.0
6.3
5.0
5.0
8.7
EMISSIONS
lb/10bBtu
5.076
5.926
5.510
6.136
8.785
4.008
5.567
5.240
7.183
5.944
4.726
gr/SCF
2.009
2.638
2.708
3.125
4.309
1.809
2.503
2.748
3.932
3.243
1.935
lb/hr
261
558
513
562
826
291
418
507
709
531
336
Velocity
ft/sec
20.18
39.52
34.77
30.87
29.71
27.82
28.96
31.70
29.10
29.74
28.14
EH
1
SD
o
H
z es
t£ O
3d EH
U 0
o
U
15
17
18
19
21
23
24
29
35
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn A
Penn B
Penn B
99
99
99
99
76
100
103
101
76
7.8
6.7
5.5
5.9
8.0
6.3
5.0
5.0
8.7
1.329
1.130
0.771
1.256
1.262
0.998
1.031
1.392
1.026
0.547
0.516
0.362
0.563
0.528
0.470
0.511
0.699
0.376
125
105
71
118
95
97
102
124
73
59.23
56.51
49.75
49.56
45.64
53.48
49.97
46.21
47.63
Load % is based on the steam flow integrator readings compared to the
unit's nameplate, or design, capacity of 80,000 Ib stm/hr.
97
-------
TABLE 5-32
HEAT LOSSES AND EFFICIENCIES
TEST SITE F
3
u
<
H
i
s
to
w
B
H
C/l
05
15
17
18
19
20
21
23
24
CO
§
CO
ri<
3
^
Q
7.49
9.33
7.78
7.07
8.48
8.65
8.44
7.16
6.37
r«i
S tJ
P H
fr^ EJ
CO fa
i H
0.42
0.52
0.47
0.52
0.74
0.19
0.18
0.20
0.31
i N
253 EC
^\
O
o 2«
K O
fa H
E-i
as co
3.64
3.82
3.75
3.89
3.96
3.56
3.67
3.59
3.71
CO
|x]
3
rf\ pFj
H C/l
E^ rij
W J*
D ^
§
85
3.58
5.32
5.50
6.24
9.00
3.82
5.20
5.45
6.86
X
to to
Ed *^
a s
EH EH
CO E~*
& O
§ ^
O H
0.96
3.34
1.70
1.04
1.46
0.44
1.01
0.77
1.47
to
m
|_j
§ w
O W
u »
J £d
«d «
8 M
4.54
8.66
7.20
7.28
10.46
4.26
6.21
6.22
8.33
OS
z 9
O H
H 0
£H 01
rtj
Q §
rtj On
0.94
0.52
0.52
0.52
0.52
0.68
0.67
0.51
0.50
a
PCJ
J3
to
<
g
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
CO
H
to
f*\
£5
j
p
8
18.53
24.35
21.22
20.78
25.66
18.84
20.67
19.18
20.72
U
^^
w
H
U
M
fa
81.47
75.65
78.78
79.22
74.34
81.46
79.33
80.82
79.28
(Q
S <
W O
29
35
6.86
8.36
0.31
0.34
3.68
3.70
6.15
4.80
1.03
1.22
7.18
6.02
0.51
0.67
1.50
1.50
20.04
20.59
79.96
79.41
98
-------
TABLE 5-33
PERCENT COMBUSTIBLES IN REFUSE
TEST SITE F
^
8
<
H
§
£q
CO
r|
W
PM
Test
No.
05
15
17
18
19
20
21
22
23
23A
24
Average
Economizer Economizer
Outlet Hopper
49.5
63.1
70.1
71.4
71.9
66.9
70.53
67.0
65.5 70.53
Multi clone
Outlet
52.1
45.0
41.3
46.1
45.5
45.8
46.0
Multiclone
Hopper
65.90
56.63
63.27
63.45
62.31
Bottom
Ash
10.62
27.23
17.34
8.21
13.79
6.05
9.90
8.62
9.60
11.42
13.81
12.42
ffl
ri]
§ O
W U
04
29
30
35
Average
47.0
72.6 49.5
72.6 48.3
13.07
64.51 10.19
13.82
64.51 12.36
99
-------
TABLE 5-34
STEAM FLOWS AND HEAT RELEASE RATES
TEST SITE F
Test
No.
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
IB
19
20
21
22
23
23A
24
25
26
27
28
29
30
31
32
33
34
35
Capacity
%
75.0
75.0
75.0
75.0
53.8
52.9
52.9
52.9
52.9
97.6
99.1
99.1
99.1
99.1
98.8
95.9
99.1
99.1
99.1
74.7
76.4
99.3
100.0
99.3
102.4
99.4
99.4
99.4
99.4
100.5
101.9
75.0
75.0
75.0
75.0
75.8
Steam Flow
103lb/hr
60.029
60.029
60.029
60.029
43.000
42.300
42.300
42.300
42.300
78.134
79 . 290
79 . 290
79.290
79 . 290
78.973
76.750
79.333
79.323
79.282
59.754
61.116
79.473
79.989
79.472
81.957
79.488
79.488
79.488
79.488
80.400
81.499
59.970
59.970
59.970
59.970
60.616
*
Heat Input
106Btu/hr
70.7
70.7
70.7
70.7
51.4
47.8
47.8
47.8
47.8
96.6
98.0
98.0
98.0
98.0
94.2
94.4
93.2
91.6
94.1
72.6
75.1
94.4
96.8
97.5
98.7
94.8
94.8
94.8
94.8
89.3
95.7
72.5
72.5
72.5
72.5
72.6
Front Foot
Heat Output Heat Release
106Btu/hr 104Btu/hr-ft
71.8
71.8
71.8
71.8
51.4
50.5
50.5
50.5
50.5
93.4
94.8
94.8
94.8
94.8
94.4
91.7
94.8
94.9
94.8
71.4
73.1
95.0
95.6
95.0
98.0
95.0
95.0
95.0
95.0
96.1
97.4
71.7
71.7
71.7
71.7
72.4
650.2
650.2
650.2
650.2
472.1
439.7
439.7
439.7
439.7
888.7
901.4
901.4
901.4
901.4
866.6
868.1
856.6
842.0
865.1
667.6
690.4
868.0
890.2
896.3
907.3
872.1
872.1
872.1
872.1
820.8
880.1
666.8
666.8
666.8
666.8
667.9
Grate Heat
Release
103Btu/hr-ft2
500.1
500.1
500.1
500.1
363.2
338.2
338.2
338.2
338.2
683.4
693.3
693.3
693.3
693.3
666.5
667.7
658.8
647.6
665.3
513.5
531.0
667.6
684.7
689.3
689.4
670.7
670.7
670.7
670.7
631.3
676.9
512.8
512.8
512.8
512.8
512.8
Furnace Heat
Release
102Btu/hr-ft3
170.4
170.4
170.4
170.4
123.7
115.2
115.2
115.2
115.2
232.9
236.2
236.2
236.2
236.2
227.1
227.5
224.5
220.6
226.7
174.9
180.9
227.5
233.3
234.9
234.8
228.5
228.5
228.5
228.5
215.1
230.6
174.7
174.7
174.7
174.7
174.7
* Heat input is based on Ib/hr coal x Btu/lb coal,
+ Heat output is based on Ib/hr steam, steam temperature and pressure,
Sometimes inaccuracies in the steam flow integrator and/or coal
scales create heat output values which are greater than the heat
input values.
100
-------
APPENDICES
APPENDIX A English and Metric Units to SI Units
APPENDIX B SI Units to English and Metric Units
APPENDIX C SI Prefixes
APPENDIX D Emissions Units Conversion Factors .
Page
102
103
104
105
APPENDIX E Unit Conversion from ppm to lb/106Btu 106
101
-------
APPENDIX A,
CONVERSION FACTORS
ENGLISH AND METRIC UNITS TO SI UNITS
To Convert From
in
in2
ft
ft2
ft3
Ib
lb/hr
lb/106BTU
g/Mcal
BTU
BTU/lb
BTU/hr
J/sec
J/hr
BTU/ft/hr
BTU/ft/hr
BTU/ft2/hr
BTU/ft2/hr
BTU/ft3/hr
BTU/ft3/hr
psia
"H20
Rankine
Fahrenheit
Celsius
Rankine
FOR TYPICAL COAL FUEL
ppm
ppm
ppm
ppm
ppm
ppm
@
@
@
@
@
@
3%
3%
3%
3%
3%
3%
°2
02
°2
02
02
°2
(S02)
(SO 3)
(NO)*
(N02)
(CO)
(CH4)
To
cm
m
m3
Kg
Mg/s
ng/J
ng/J
J
JAg
w
w
w
w/m
J/hr/m
J/hr/m2
W/ra3
J/hr/m3
Pa
Pa
Celsius
Celsius
Kelvin
Kelvin
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
(Ib/lO^tu)
(Ib/lO^Btu)
(lb/106Btu)
(lb/106Btu)
(Ib/lO^tu)
(lb/106Btu)
Multiply By
2.540
6.452
0.3048
0.09290
0.02832
0.4536
0.1260
430
239
1054
2324
0.2929
1.000
3600
0.9609
3459
3.152
11349
10.34
37234
6895
249.1
C
C
K
K
5/9R-273
5/9(F-32)
C+273
5/9 R
0.851
1.063
0.399
0.611
0.372
0.213
(1. 98x10" J)
(2.47xlO~3)
{9.28xlO~4)
(1.42X1Q-3)
(8.65xlO~4)
(4.95xlO~4)
*Federal environmental regulations express NOx in terms of
thus NO units should be converted using the N02 conversion factor.
102
-------
APPENDIX B
CONVERSION FACTORS
SI UNITS TO ENGLISH AND METRIC UNITS
To Convert From
cm
m
m^
Kg
Mg/s
ng/J
ng/J
J
JAg
J/hr/m
JAr/m2
JAr/m3
W
W
W/m
W/m2
W/m3
Pa
Pa
Kelvin
Celsius
Fahrenheit
Kelvin
To
in
in2
ft
ft2
ft3
Ib
IbAr
Ib/lO^TU
g/Mcal
BTU
BTU/lb
BTU/ftAr
BTU/ft2Ar
BTU/ft3Ar
BTUAr
JAr
BTU/ftAr
BTU/ft2Ar
BTU/ft3/hr
psia
"H20
Fahrenheit
Fahrenheit
Rankine
Rankine
Multiply By
0.3937
0.1550
3.281
10.764
35.315
2.205
7.937
0.00233
0.00418
0.000948
0.000430
0.000289
0.0000881
0.0000269
3.414
0.000278
1.041
0.317
0.0967
0.000145
0.004014
F = 1.8K-460
F = 1.8C+32
R = F+460
R = 1.8K
FOR TYPICAL COAL FUEL
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
ppm
ppra
ppm
ppm
ppm
ppm
@
@
@
@
@
@
3%
3%
3%
3%
3%
3%
°2
°2
02
02
02
02
(S02)
(S03)
(NO)
(N02)
(CO)
(CH4)
1
0
2
1
2
4
.18
.941
.51
.64
.69
.69
103
-------
APPENDIX C
SI PREFIXES
Multiplication
Factor Prefix SI Symbol
1018 exa E
1015 peta P
1012 tera T
10? giga G
10 mega M
kilo k
10 hecto* h
10* deka* da
10 deci* d
10 centi* c
10~ 3 mi Hi m
10"6 micro y
10~9 nano n
p
10~15 femto f
10" 18 at to a
*Not recommended but occasionally used
104
-------
APPENDIX D
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
0.405
grams/106Cal
S02 NOj
0.370
0.225
PPM
(Dry @ 3% O2>
SOx NOx
3.2x10
-4
.76x10"
Grains/SCF.
(Dry @ 12% CO2)
S02 NO2
1.48
7
.903
lbs/106Btu
SO,
1.50
NO,
(.556)
19.8xlO~4
<2.23)
2.47
(.556)
14.2x10"
(2.23)
SO,
2.70
grams/106Cal
(1.8)
NO,
4.44
SOx
PPM
(Dry 6 3%O2)
NOx
758
505
1736
35.6x10'
,-4
(4.01)
(1.8)
281
704
25.6x10"
(4.01)
1127
391
1566
S02
Grains/SCF
(Dry 612% CO2>
N02
.676
(.448)
(.249)
8.87xlO~4
1.11
(.448)
(.249)
6.39x10"
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.
105
-------
APPENDIX E
UNITS CONVERSION FROM PARTS PER MILLION (PPM) TO
POUNDS PER MILLION BTU INPUT (LB/IO^TU)
- SCP
Ib/lO^tu = (ppm) (fuel factor, 1QbBt ) (C>2 correction, n.d.) (density of
emission, ~r) (10~6)
£L
Fuel factor, 1q^tu - 106{1.53C + 3.61H2 + .14N2 + .575 - .46O2] *
(Btu/lb)
where C, H2, N2, S, O2 & Btu/lb are from ultimate fuel analysis;
(a typical fuel factor for coal is 9820 SCF/lO^tu ±1000)
02 correction, n.d. = 20.9 -r (20.9 - %O2)
where %O2 is oxygen level on which ppm value is based;
for ppm @ 3% O2, O2 correction ~ 20.9 T 17.9 = 1.168
Density of emission = SO2 - 0.1696 Ib/SCF*
NO - 0.0778 Ib/SCF
CO - 0.0724 Ib/SCP
CH4 - 0.0415 Ib/SCF
to convert lbs/10°Btu to ng/J multiply by 430
* Standard conditions are 70°F, 29.92 "Hg barometric pressure
106
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/7-80-065a
2.
3. RECIPIENT'S ACCESSION-NO.
». TITLE ANDSUBTITLE
Field Tests of Industrial Stoker Coal-fired Boilers for
Emissions Control and Efficiency Improvement
Site F
i. REPORT DATE
March 1980
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
P.L.Langsjoen, R.J.Tidona, and J.E.Gabrielson
!. PERFORMING ORGANIZATION REPORT NO.
>. PERFORMING ORGANIZATION NAME AND ADDRESS
KVB, Inc.
6176 Olson Memorial Highway
Minneapolis, Minnesota 55422
10. PROGRAM ELEMENT NO.
EHE624
11. CONTRACT/GRANT NO.
IAG-D7-E681 (EPA) and
EF-77-C-01-2609 (DOE)
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
13. TYPE OF REPORT AND I
Final; 12/78-2/79
14. SPONSORING AGENCY CODE
EPA/600A3
IB.SUPPLEMENTARYNOTESIERL-RTP project officer is R.E.Hall. (*) Cosponsors are DoE
(W.T.Harvey Jr.) and the American Boiler Manufacturers Assoc. EPA-600/7-78-
136a, -79-041a, -79-130a, -79-147a, and -80-Q64aare Site A,B,C,D, and E reports.
16. ABSTRACT
The report gives results of field measurements made on an 80,000 Ib/hr
coal-fired spreader-stoker boiler. The effects of various parameters on boiler emis
sions and efficiency were studied. Parameters included overfire air, flyash injec-
tion, excess air, boiler load, and coal properties. Measurements included O2, CO2,
CO, NO, NO2, SO2, SOS, HC, controlled and uncontrolled particulate loading, par-
ticle size distribution of the uncontrolled flyash, and combustible content of the ash.
In addition to test results and observations, the report describes the facility tested,
coals fired, test equipment, and procedures. Particulate loading on this unit aver-
aged 6.00 Ib/million Btu uncontrolled and 1.05 Ib/miUion Btu controlled at full load.
Nitric oxide emissions averaged 0.45 Ib/million Btu (330 ppm) at all loads.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Air Pollution
Boilers
Combustion
Coal
Field Tests
Dust
Stokers
Improvement
Efficiency
Flue Gases
Fly Ash
Particle Size
Nitrogen Oxides
Sulfur Oxides
Air Pollution Control
Stationary Sources
Combustion Modification
Spreader Stokers
Particulate
Overfire Air
Flyash Reinjection
13B
13A
21B
21D
14B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
113
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (t-73)
107
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