ABMA
American
Boiler Manufacturers
Association
1500 Wilson Boulevard
Arlington VA 22209
Dol
United States
Department
of Energy
Division of Power Systems
Energy Technology Branch
Washington DC 20545
PA
U.S. Environmental Protection Agency
Office of Research and Development
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA 600 7 80-082a
April 1980
Field Tests of
Industrial Stoker Coal-
fired Boilers for Emissions
Control and Efficiency
Improvement - Site G
Interagency
Energy/Environment
R&D Program Report
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of, and development of, control technologies for energy
systems; and integrated assessments of a wide'range of energy-related environ-
mental issues.
EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
for publication. Approval does not signify that the contents necessarily reflect
the views and policies of the Government, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/7-80-082a
April 1980
Field Tests of Industrial Stoker
Coal-fired Boilers for
Emissions Control and Efficiency
Improvement - Site G
by
P.L. Langsjoen, J.O. Burlingame,
and J.E. Gabrielson
KVB, Inc.
6176 Olson Memorial Highway
Minneapolis, Minnesota 55422
lAG/Contract Nos. IAG-D7-E681 (EPA), EH-77-C-01-2609 (DoE)
Program Element No. EHE624
Project Officers: R.E. Hall (EPA) and W.T. Harvey, Jr. (DoE)
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
U.S. DEPARTMENT OF ENERGY
Division of Power Systems/Energy Technology Branch
Washington, DC 20545
and
AMERICAN BOILER MANUFACTURERS ASSOCIATION
1500 Wilson Boulevard
Arlington, VA 22209
-------
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 G were
Bruce Crockett, Russ Parker, Mike Jackson, and Jim Demont.
Finally, our gratitude goes to the host boiler facilities which in-
vited us to test their boiler. At their request, the facilities will remain
anonymous to protect their own interests. Without their cooperation and
assistance this program would not have been possible.
ii
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TABLE OF CONTENTS
Section Page
ACKNOWLEDGEMENTS ii
LIST OF FIGURES v
LIST OF TABLES vi
1.0 INTRODUCTION 1
2.0 EXECUTIVE SUMMARY 3
3.0 DESCRIPTION OF FACILITY TESTED AND i.XALS FIRED 11
3.1 Boiler Description 11
3.2 Overfire Air System 11
3.3 Flyash Reinjection 11
3.4 Mechanical Dust Collector 17
3.5 Test Port Locations 17
3.6 Coals Utilized 17
4.0 TEST EQUIPMENT AND PROCEDURES 21
4.1 Gaseous Emissions Measurements (NOX, CO, CO2, O2, HC) . . 21
4.1.1 Analytical Instruments and Related Equipment ... 21
4.1.2 Recording Instruments 25
4.1.3 Gas Sampling and Conditioning System 25
4.1.4 Gaseous Emission Sampling Techniques 25
4.2 Sulfur Oxides (SOx) Measurement and Procedures 27
4.3 Particulate Measurement and Procedures 29
4.4 Particle Size Distribution Measurement and Procedures . . 32
4.5 Coal Sampling and Analysis Procedure 33
4.6 Ash Collection and Analysis for Combustibles 35
4.7 Boiler Efficiency Evaluation 36
4.8 Trace Species Measurement 36
5.0 TEST RESULTS AND OBSERVATIONS 39
5.1 Overfire Air 39
5.1.1 Particulate Loading vs Overfire Air 39
5.1.2 Nitrix Oxide vs Overfire Air . . : 41
5.1.3 Boiler Efficiency vs Overfire Air 42
5.1.4 Overfire Air Flow Rate 42
5.2 Flyash Reinjection 47
5.3 Excess Oxygen and Grate Heat Release 48
5.3.1 Excess Oxygen Operating Levels 48
5.3.2 Particulate Loading vs Grate Heat Release .... 50
5.3.3 Nitrogen Oxides vs Oxygen and Grate Heat Release . 52
5.3.4 Hydrocarbons vs Oxygen and Grate Heat Release . . 61
5.3.5 Combustibles in the Ash vs Oxygen and Grate
Heat Release 61
5.3.6 Boiler Efficiency vs Grate Heat Release 68
111
-------
TABLE OF CONTENTS
(Continued)
5.4 Coal Properties 72
5.4.1 Chemical Composition of the Coals 72
5.4.2 Coal Size Consistency 77
5.4.3 Effect of Coal Properties on Emissions
and Efficiency 77
5.5 Particle Size Distribution of Flyash 86
5.6 Efficiency of Multiclone Dust Collector 93
5.7 Source Assessment Sampling System 93
5.8 Data Tables 95
APPENDIX A - Discussion of Low Ash Coal Problem 102
APPENDIX B - English and Metric Units to SI Units 103
APPENDIX C - SI Units to English and Metric Units 104
APPENDIX D - SI Prefixes 105
APPENDIX E - Emissions Units Conversion Factors 106
APPENDIX F - Unit Conversion from ppm to lb/10^Btu 107
iv
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LIST OF FIGURES
Figure Page_
3-1 Schematic of Boiler G 12
3-2 Plan View of Front and Rear Upper Overfire Air System .... 15
3-3 Rear Elevation Drawing Showing Arrangement of Rear Upper
and Lower Overfire Air System, and Flyash Reinjection
System 16
3-4 Boiler G Sample Plane Geometry 18
4-1 Flow Schematic of Mobile Flue Gas Monitoring Laboratory ... 26
4-2 SOx Sample Probe Construction 28
4-3 Sulfur Oxides Sampling Train (Shell-Emeryville) 28
4-4 Sulfur Oxides Sampling Train (EPA Method 6) 30
4-5 Particulate Sampling Train (EPA Method 5) 31
4-6 Brink Cascade Impactor Sampling Train 34
4-7 Source Assessment Samplying System (SASS) Sampling Train ... 38
5-1 Schematic of Overfire Air System Showing Location of Flow
Rate Measurements 43
5-2 Overfire Air Flow Rate as a Function of Static Pressure ... 46
5-3 Oxygen vs Grate Heat Release 49
5-4 Boiler Outlet Particulate vs Grate Heat Release 51
5-5 Dust Collector Outlet Particulate vs Grate Heat Release ... 53
5-6 Nitric Oxide vs Grate Heat Release 55
5-7 Nitric Oxide vs Oxygen 56
5-8 Nitric Oxide vs Oxygen (100% Capacity) 57
5-9 Nitric Oxide vs Oxygen (80% Capacity) 58
5-10 Nitric Oxide vs Oxygen (17% Capacity) 59
5-11 Nitric Oxide vs Oxygen (Trend Lines) 60
5-12 Hydrocarbons vs Grate Heat Release 62
5-13 Hydrocarbons vs Oxygen 63
5-14 Bottom Ash Combustibles vs Grate Heat Release 64
5-15 Boiler Outlet Combustibles vs Grate Heat Release 65
5-16 Dust Collector Outlet Combustibles vs Grate Heat Release ... 66
5-17 Dust Collector Catch Combustibles vs Grate Heat Release ... 67
5-18 Boiler Efficiency vs Grate Heat Release 69
5-19 Size Consistency of "As Fired" White Ash Coal vs ABMA Recommended
Limits of Coal Sizing for Spreader Stokers 79
5-20 Size Consistency of "As Fired" Spurlock Coal vs ABMA
Recommended Limits of Coal Sizing for Spreader Stokers ... 80
5-21 Size Consistency of "As Fired" Pevler Coal vs ABMA
Recommended Limits of Coal Sizing for Spreader Stokers ... 81
5-22 Particle Size Distribution of the Boiler Outlet Flyash
by Bahco Classifier and Sieve Analysis 89
5-23 Particle Size Distribution at the Boiler Outlet by Brink
Cascade Impactor 90
5-24 Particle Size Distribution at the Boiler Outlet by SASS
Gravimetrics ..... 91
5-25 Dust Collector Efficiency vs Grate Heat Release 95
v
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LIST OF TABLES
Table Page
2-1 Test Plan 9
2-2 Emission Data Summary IQ
3-1 Design Data 13
3-2 Predicted Performance Data 14
3-3 Average Coal Analysis 19
5-1 Effect of Overfire Air on Emissions and Efficiency 40
5-2 Participate Loading vs Overfire Air 41
5-3 Nitric Oxide vs Overfire Air 41
5-4 Boiler Efficiency vs Overfire Air 42
5-5 Overfire Air and Reinjection Air Flow Rates 45
5-6 Particulate Loading vs Flyash Reinjection 47
5-7 Boiler Efficiency vs Flyash Reinjection 48
5-8 Ash Carryover vs Coal Type 52
5-9 Average Nitric Oxide Concentrations vs Load 54
5-10 Boiler Efficiency vs Load 68
5-11 Predicted vs Measured Heat Losses 70
5-12 Predicted vs Measured Performance Data 71
5-13 Coal Properties Corrected to a Constant 106Btu Basis 72
5-14 Fuel Analysis - White Ash Coal 73
5-15 Fuel Analysis - Spurlock Coal 74
5-16 Fuel Analysis - Pevler Coal 75
5-17 Mineral Analysis of Coal Ash 75
5-18 As Fired Coal Size Consistency 73
5-19 Effect of Coal Change on Particulate Loading 82
5-20 Sulfur Balance on Boiler G 84
5-21 Average Percent Combustible in Ash at Loads Above 50% 85
5-22 Boiler Efficiency vs Coal 85
5-23 Description of Particle Size Distribution Tests at the Boiler
Outlet 87
5-24 Results of Particle Size Distribution Tests at the Boiler Outlet 88
5-25 Particle Size Distribution vs Dust Collector Efficiency 92
5-26 Efficiency of Dust Collector 94
5-27 Polynuclear Aromatic Hydrocarbons Analyzed in the Site G SASS
Sample 95
5-28 Particulate Emissions 97
5-29 Heat Losses and Efficiencies 98
5-30 Percent Combustibles in Refuse 99
5-31 Steam Flow and Heat Release Rates
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, 13 to produr-a information which will in-
crease the ability of boiler manufac irers to design and fabricate stoker
boilers that are an economical and envi^., mentally satisfactory alternative
to oil-fired units. Further objectives v he ^^ogram are to: provide
information to stoker boiler operators concerning the efficient operation of
their boilers; provide assistance to stoker boiler operators in planning
their coal supply contracts; refine application of existing pollution control
equipment with special emphasis on performance; and contribute to the design
of new pollution control equipment.
In order to meet these objectives, it is necessary to define stoker
boiler designs which will provide efficient operation and minimum gaseous and
particulate emissions, and define what those emissions are in order to facili-
tate preparation of attainable national emission standards for industrial
size, coal-fired boilers. To do this, boiler emissions and efficiency must
be measured as a function of coal analysis and sizing, rate of flyash rein-
jection, overfire air admission, ash handling, grate size, and other variables
for different boiler, furnace, and stoker designs.
A field test program designed to address the objectives outlined above
was awarded to the American Boiler Manufacturers Association (ABMA), sponsored
by the United States Department of Energy (DOE) under contract number
EF-77-C-01-2609, and co-sponsored by the United States Environmental Protection
Agency (EPA) under inter-agency agreement number IAG-D7-E681. The program is
directed by an ABMA Stoker Technical Committee which, in turn, has subcontracted
the field test portion to KVB, Inc., of Minneapolis, Minnesota.
This report is the Final Technical Report for the seventh 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
combine and correlate the test results from all sites tested. A report
containing operating guidelines for boiler operators will also be written,
along with a separate report covering trace species data. These reports will
be available to interested parties through the National Technical Information
Service (NTIS) or through the EPA's Technical Library.
Although it is EPA policy to use S.I. units in all EPA sponsored
reports, an exception has been made herein because English units have been
conventionally used to describe boiler design and operation. Conversion
tables are provided in the Appendix for those who prefer S.I. units.
To protect the interests of the host boiler facilities, each test
site in this program has been given a letter designation. As the seventh
site tested, this is the Final Technical Report for Test Site G 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 75,000 Ibs steam/hour was
extensively tested for emissions and efficiency between February 10 and
March 25, 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, page 11.
0 Zurn Boiler
Built 1974
Type V.C. 2 drum
75,000 Ibs/hr rated capacity
140 psig operating steam pressure
Saturated steam
0 Zurn Stoker
Spreader with 3 feeders
Traveling grate with front ash discharge
Flyash reinjection from boiler hopper only
Two rows OFA on back water wall and one row on front
COALS TESTED; Described in Section 3.6, page 17, and Section 5.4, page 72.
0 White Ash Coal
12,869 Btu/lb
8.05% Ash
0.78% Sulfur
4.56% Moisture
2700+°F Initial ash deformation temperature
0 Spurlock Coal
13,860 Btu/lb
4.42% Ash
1.31% Sulfur
3.02% Moisture
2420°F Initial ash deformation temperature
-------
0 Pevler Coal
12,832 Btu/lb
7.32% Ash
0.76% Sulfur
4.59% Moisture
2700+°F Initial ash deformation temperature
OVERFIRE AIR TEST RESULTS; Overfire air pressure was varied from 23" H2O
pressure (baseline) to as low as 12" H20 pressure
(low) in two test sets with the boiler operating
at its design capacity. Overfire air flow rate
was also measured and related to static pressure.
The test results follow (Section 5.1, page 39,
Table 5-1, page 40.
0 Particulate Loading
Conflicting trends were observed for particulate loading vs
OFA in the two test sets. The variations were interpreted as
normal data scatter and unrelated to OFA conditions (Section
5.1.1, page 39, Table 5-2, page 41).
0 Nitric Oxide
Conflicting trends were observed for nitric oxide concentration
vs OFA in the two test sets. The variations were interpreted
as normal data scatter and unrelated to OFA conditions.
(Section 5.1.2, page 41, Table 5-3, page 41).
0 Boiler Efficiency
Boiler efficiency was highest at low OFA in both test sets.
It is reasoned that these efficiency variations were unrelated
to OFA conditions because flyash combustibles were not sig-
nificantly changed (Section 5.1.3, page 42, Table 5-4, page 42).
0 Overfire Air Flow Rate
Overfire air was found to constitute 10% of the furnace
combustion air. Eighty-five percent of the overfire air is
introduced through the back wall. The overfire air flow (Ibs/hr)
and overfire air static pressure ("H2O) relationship for each
row of jets is presented. (Section 5.1.4, page 42, Figures 5-1
and 5-2, pages 43 and 46, Table 5-5, page 45).
C Carbon Monoxide
No data is available because the carbon monoxide gas analyzer
was out of service during Testing at Site G.
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FLYASH REINJECTION: BoUer G pneumaticall rein;ects flyash from the boiler
hopper. ""..are is no reinjt v tion from the dust collector.
During one test the t ..Icr lopper ash was diverted to
barrels. The esultL, of this test follow (Section 5.2,
page 47) .
0 Particulate Loading
Reduced reinjection resulted in a 14% drop in particulate mass
loading at the boiler ov^let (Table 5-6, page 47).
0 Boiler Efficiency
The boiler hopper ash represents e 1.1% potential efficiency
gain when reinjected. Thus boiler efficiency was assuned to
drop by this amount when reinjection was stopped. Percent
combustibles in the ash was higher during the non-reinjection
test. (Table 5-7, page 48).
BOILER EMISSION PROFILES; Boiler emissions and efficiency were measured over
the. load range 16% to 102% of design capacity which
corresponds to a grate heat release range of 130,000
to 830,000 Btu/hr-ft2. Measured oxygen levels ranged
from 4.1 to 15.2% (Section 5.3, page 48).
0 Excess Oxygen Operating Levels
At full load, the unit was normally operated in the range 6.5 to
7.5% O2 (42 to 53% excess air). Oxygen increased as load decreased
such that 14.6 to 15.2% O2 (205 to 241% excess air) was used at the
very low loads of 16-17% capacity. Manufacturers predicted perform-
ance was based on 31% excess air at full load (Section 5.3.1,
page 48, Figure 5-3, page 49).
0 Particulate Loading
At full load and normal operating conditions the boiler outlet
particulate loading ranged from 2.93 to 6.79 lbs/106Btu and
averaged 5.09 lbs/10^ Btu. After the mechanical dust collector
the full load particulate loading ranged from 0.17 to 0.36
lbs/106Btu and averaged 0.28 lbs/106Btu. The average ash carry-
over was 41% at the high loads and 25% at the lowest loads. Swing
load conditions produced 60% higher particulate emissions than base
load conditions (Section 5.3.2, page 50, Figures 5-4, 5-5, pages
51, 53, Table 5-8, page 52).
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0 Nitrogen Oxides
Nitric oxide (NO) averaged 0.49 lbs/10 Btu (360 ppm) at full
load and 0.51 lbs/106Btu (379 ppm) at 80% and 17% of capacity.
Nitric oxide increased by 0.046 lbs/10 Btu for each one percent
increase in oxygen at constant load. Nitrogen dioxide (NO )
concentrations were negligible (Section 5.3.3, page 52, Figures
5-6 through 5-11, pages 55-60, Table 5-9, page 54).
0 Hydrocarbons
Hydrocarbons (HC) showed signs of decreasing with decreasing
load, averaging 33 ppm at full capacity and 22 ppm at 80% capacity.
Hydrocarbon concentrations also decreased as oxygen increased at
80% load (Section 5.3.4, page 61, Figures 5-12 and 5-13, pages
62 and 63).
0 Combustibles in the Ash
The combustible content of the flyash and bottom ash was slightly
higher at high loads than at low loads. No trend with oxygen
was observed. Bottom ash averaged 10% combustible. Combustible
contents of the flyash averaged 53% at the boiler outlet, 32% at
the dust collector outlet, and 54% in the dust collector hopper
(Section 5.3.5, page 61, Figures 5-14 through 5-17, pages 64, 65, 66
and 67).
BOILER EFFICIENCY;
Measured boiler efficiency was several percent lower than
the manufacturer's predicted efficiency because the unit
was operated at a higher than predicted excess air. Boiler
efficiencies averaged 75.8% at full capacity (77.0% predicted),
74.5% at 80% capacity (79.2% predicted) and 65.5% at 17%
capacity (Section 5.3.6, page 68, Figure 5-18, page 69,
Tables 5-10, 5-11, 5-12, pages 68, 70, 71).
COAL PROPERTIES;
Three coals were test fired. Proximate analysis and size
consistency were determined for coal samples from most
tests. Ultimate and mineral analysis were determined for
selected tests (Section 5.4, page 72).
0 Chemical Analysis
White Ash and Pevler coals were very similar. Spurlock coal was
lower in both moisture and ash, and higher in sulfur content
(Section 5.4.1, page 72, Tables 5-13 through 5-17, pages 72-76).
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0 Coal Size Consistency
Pevler A coal had the lowest percentage of fines at an
average 22%. Blend coal had 41% fines and Pevler B coal
had 36% fines. The coal size consistency of all three coals
was within the ABMA recommended limits for spreader stokers.
(Section 5.4.2, page 77, Table 5-18, page 78, Figures 5-19,
5-20, 5-21, pages 79, 80, 81).
0 Effect on Emissions and Efficiency
The low ash low fines Pevler A coal produced the lowest
particulate loadings at full load. Nitric oxide emissions
were similar for all three coals. Sulfur dioxide was pro-
portional to sulfur content of coal. Sulfur retention in
the ash was 3.5 to 6.0% of the fuel sulfur. Pevler A coal
had the lowest combustible fraction in the bottom ash but
the highest combustible fraction in the dust collector outlet
flyash. Pevler A coal gave the highest boiler efficiency be-
cause of its low combustible heat loss. (Section 5.4.3, page 77)
PARTICLE SIZE DISTRIBUTION OF FLYASH:
Ten particle size distribution measure-
ments were made at the boiler outlet.
Results vary with measurement technique.
Pevler B coal produced more fines than
either Blend or Pevler A coals (Section
5.5, page 86, Tables 5-23, 5-24, 5-25,
pages 87, 88, 92, Figures 5-22, 5-23,
5-24, pages 89, 90, 91).
EFFICIENCY OF MULTICLONE DUST COLLECTOR:
The collection efficiency of the
mechanical dust collector averaged
94.4% at loads of 80% and 100% design
capacity. Collection efficiency drop-
ped to an average 63.4% at low loads
of 17% design capacity (Section 5.6,
page 96, Table 5-26, page 94, Figure
5-25, page 92).
SOURCE ASSESSMENT SAMPLING SYSTEM:
Flue gas was sampled for polynuclear aromatic
hydrocarbons and trace elements during two
tests on Blend coal and one test on Pevler B
coal. Trace specie data will be presented
for all boilers tested in a separate report
upon completion of the test program (Section
5.7, page 93, Table 5-27, page 96).
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The test plan and the emissions data are summarized in Tables 2-1
and 2-2 on the following pages. Other data tables are included at the end
of Section 5.0, Test Results and Observations. For reference, a Data Supple-
ment containing all the unreduced data obtained at Site G 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
TEST PLAN FOR TEST SITE G
Firing Conditions
% boiler
Capacity
100%
100%
100%
80%
80%
80*
80%
80%
60%
15%
NA
NA
Load
Condition
baseline
baseline
baseline
baseline
baseline
baseline
Swing
Swing
baseline
baseline
NA
NA
Excess
Air
norm
norm
Vary
norm
norm
Vary
norm
norm
norm
norm
NA
NA
Overf ire
Air
norm
norm
norm
norm
Low
norm
norm
norm
norm
norm
norm
Low
Flyash
Rein jection
norm
No
norm
norm
norm
norm
norm
norm
norm
norm
NA
NA
Test Measurements Test No.
Flue Gas Part.
Composition Loading
X X
X X
X
X X
X X
X
X X
X
X X
X X
OFA White Si urlock
SASS SOx Flow Rate Ash Coal
5 8
17
12
2
3
11
4 & 10
XX 9 & 15
6
16 7
X 13 & 14
X
Pevler
Coal
18
25
23
24
26
22
20
19
20
Note: Normal (norm) Overf ire Air is the maximum system output at high loads.
Normal (norm) Flyash Reinjection is from the boiler hopper only.
Flue Gas Composition includes 02* CC>2 and NO on all tests, NO2 and HC
on selected tests. CO instrument was out of service during testing.
Participate Loadings were taken simultaneously at boiler outlet (uncontrolled)
and at dust collector outlet (controlled).
SASS stands for Source Assessment Sampling System and is used to measure
trace elements and organic species in the flue gas, as well as provide
a particle size distribution of the flyash.
SOx (SO2 & SO-s) was measured by the Shell-Emeryville wet chemical method) ,
and by the EPA test method 6.
OFA Flow Rate is a measure of Ibs/hr air injected into the furnace above
the grate by the overfire air system.
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TABLE 2-2
EMISSION DATA SUMMARY
TEST SITE G
Ttest
No.
1
2
3
4
5
6
7
8
9
10
11A
11B
UC
11D
12A
12B
12C
12D
12E
13
14
15
16
17
18
19
20
21
22
23
24
25A
25B
25C
25D
26A
26B
26C
260
Date
2/10/79
2/11/79
2/11/79
2/16/79
2/17/79
2/17/79
2/25/79
2/25/79
2/28/79
3/02/79
3/03/79
3/03/79
3/03/79
3/0 3/7'J
3/03/79
3/03/79
3/03/79
3/03/79
3/03/79
3/15/79
3/15/79
3/K./79
3/17/79
3/17/79
3/18/79
VI 8/79
3/21/79
3/22/79
3/23/79
3/24/79
3/24/79
V5V79
3/25/V9
3/25/79
J/2'j/V'J
3/25/79
3/25/79
3/25/79
I/? ./70
% Design
Capacity
92
85
80
77
102
57
17
100
72
86
78
78
78
78
98
98
98
98
98
—
H7
16
98
97
17
78
—
82
76
78
1(1(1
100
100
I IV)
78
78
78
7H
Coal
W
w
w
w
w
w
s
5
W
W
W
W
w
w
w
w
w
w
w
w
w
w
w
w
p
V
F
f
F
*
V
f
p
p
V
f
p
p
p
Excess
Air
%
69
67
94
48
96
205
43
89
82
58
53
44
38
49
46
39
36
29
—
69
241
52
53
230
74
—
73
58
51
38
3b
31
22
59
48
38
31
°2
*
dry
8.9
8.7
10.4
7.0
10.5
14.6
6.6
10.2
9.7
8.0
7.6
6.7
6.0
7.2
6.8
6.1
5.8
5.0
—
8.7
15.2
7.4
7.5
15.1
9.2
—
9.1
8.0
7.3
6.0
5.7
5.2
4.0
8.0
7.0
6.0
5.2
oo2
dry
10.2
10.5
9.4
12.0
9.4
4.4
11.6
9.0
9.8
11.0
11.0
12.2
12.8
11.6
12.2
12.4
12.4
13.2
—
10.6
4.6
11.5
11.6
4.1
10.4
—
10.3
11.2
11.7
12.8
13.2
13.2
14.2
11.4
12.2
13.2
13.7
NO
ppm
drjr
321
380
486
380
478
364
306
330
442
402
458
358
300
418
381
363
320
304
—
__
457
391
397
4.5
381
396
—
414
423
336
36O
3HH
353
29f>
402
348
300
2f.5
NO
lb/106Btu
0.435
0.515
0.658
0.515
0.647
0.492
0.414
0.447
0.599
0.544
0.620
0.485
0.406
0.566
0.516
0.492
0.433
0.412
~
0.621
0.529
0.538
0.563
0.517
0.536
—
0.561
0.573
0.456
0.488
0.b2G
0.479
0.41)1
0.545
0.472
0.407
0. 359
N02
lb/10DBtu
—
—
0.000
—
—
0.000
0.000
—
O.004
0.000
0.000
o.ooo
o.ooo
0.000
0.000
0.000
0.000
0.000
—
__
o.ooo
o.uoo
o.ooo
0.009
0.000
o.ooo
—
o.ooo
0.000
o.oou
—
--
—
—
--
—
—
HC Part.
ppm Blr Out
wet lb/106Btu
4.271
4.332
7.408
6 . 786
4.171
2 . 1 39
2.932
—
6.592
19
20
23
24
39
41
35
38
39
—
—
2.215
5 . 858
4.783
2.057
—
—
4.720
4.567
4.IKI3
—
—
—
--
--
—
--
Part.
D.C.Out
lb/106Btu
0.222
0.220
0.221
0.274
0.129
0.953
0.166
—
0.484
__
—
—
—
—
—
—
—
—
__
—
(l.'lli
0.364
0. 320
0.495
—
—
0. J34
0.320
IJ.2.,0
--
--
--
-*
--
--
--
Special
Tests or
Condi tions
Aborted Test
Low OFA
Brink Impactor
SASS, SOX
OFA Flow Rate
OFA Flow Rate
SAKS , SOX
No Rein}., Brink
SASK , SO
OFA Flow Rate
I.OW UFA
Note: Coal: W-White Ash, S-Spurlock, P-Pevler
SO2 (lb/106Btu): Test 9 - 1.198, Test 15 - 1.050, Test 20 - 1.039
803 (lb/10^tu): Test 9 - 0.010, Test 15 - 0.006, Test 20 - 0.010
Carbon Monoxide not measured because of equipment out-of-service
-------
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 G. The coals used in
this test series are also discussed.
3.1 BOILER DESCRIPTION
Boiler G was built in 1974 by Zurn Industries, Inc., and equipped
with a Zurn spreader stoker. The boiler is rated at 75,000 Ibs/hr continuous
operation at 160 psig saturated steam. As found operating pressure was 140 psig.
A boiler schematic is presented in Figure 3-1.
The Zurn Travagrate spreader stoker has three coal feeders and
continuous front end ash discharge. The effective area of the grate is
137 ft . Design data on the boiler and stoker are presented in Table 3-1.
Predicted performance data at various loads are presented in Table 3-2.
3.2 OVEKFIRE AIR SYSTEM
The overfire air system consists of a row of lower overfire air
jets on the front wall and a row each of upper and lower overfire air jets
on the rear wall. There are 12 jets spaced ten inches apart in the front
row and 14 jets spaced nine inches apart in back. This configuration is
shown in Figure 3-2. Overfire air is supplied by an independent fan, and
is not preheated.
3.3 FLYASH REINJECTION
Flyash is pneumatically reinjected from the boiler dust hopper
only; through three nozzles which take the place of the number 3, 7, and
12 lower overfire air jets. Figure 3-3 shows this configuration. One test
at this site was run without reinjection in an attempt to determine any
changes in particulate loading and boiler efficiency due to this variable.
11
-------
Dust Collector Outlet
Sampling Plane *
Boiler Outlet
Sampling Plane
Flyash Reinjection From
Boiler Hopper
FIGURE 3-1. Schematic of Boiler G
12
-------
TABLE 3-1
DESIGN DATA
TEST SITE G
BOILER: Manufacturer
Type
Boiler Heating Surface
Design Pressure
Waterwall Heating Surface
Feedwater Temperature
FURNACE: Volume
STOKER: Manufacturer
Type
Grate Type
Ash Discharge
Effective Grate Width
Effective Grate Length
Effective Grate Area
Zurn Industries
V.C. 2 drum
8,280 ft2
200 psig
2,140 ft2
212 °F
4,100 ft3
Zurn Industries
Spreader
Traveling Continuous
Front
9'9"
14' 2"
137 ft2
HEAT RATES: Steam Flow
Input to Furnace
Total Heat Available
Furnace Width Heat Release
Grate Heat Release
Furnace Liberation
75,000 Ibs/hr
98.95 x!06Btu/hr
88.98 x!06Btu/hr
10.2 x!06Btu/ft-hr
714 x!03Btu/ft2-hr
24 x!03Btu/ft3-hr
13
-------
TABLE 3-2
PREDICTED PERFORMANCE DATA
TEST SITE G
Steam Flow
Type of Fuel
Excess Air Leaving
Fuel
Flue Gas Leaving
Combustion Air
Drum Pressure
Gas Temperature Leaving Furnace
Gas Temperature Leaving Boiler
F.W. to Boiler
Furnace Draft Loss
Boiler Draft Loss
Burner and Blast Gate D.L.
Duct Draft Loss
Damper Draft Loss
Dry Gas Losses
H2 and H20 in Fuel Losses
Moisture in Air Losses
Unburned Combustible Losses
Radiation Losses
Manufacturers Margin
Total Heat Losses
Efficiency of Unit
75,000 Ibs/hr
Coal
31 %
7.71 x!03lbs/hr
103.48 x!03lbs/hr
93.07 x!03lbs/hr
160 psig
1,815 °F
530 °F
212 °F
0.15 "H20
1.35 "H20
2.70 "H20
0.25 "H20
0.50 "H20
10.74 %
4.93 %
0.27 %
4.95 %
0.57 %
1.50 %
22.96 %
77.04 %
14
-------
Front WW
Front overfire air jets: l'4-3/4" above grate;
horizontal
Rear Upper Jets: 5'7" above grate; 5° below horizontal
Rear Lower Jets: I'lO" above grate; 5° below horizontal
R: Marks location of flyash reinjection lines which
replace three overfire air jets in lower row.
1 3 , 5 • S 3 3 9 4;4J J 9 99 9 S \
'•• 'r i'-i
Rf>ay WW
' (
or
TOO
COf
CO
J
00
PCX
-t
P°[
I
OOf
vDO
30
?
i
Dor
pC
cor
oo
p^- — 4
i
11) '\
1 H
R
R
R
FIGURE 3-2. Plan View of Front and Rear Upper Overfire
Air System - Test Site G
15
-------
Rear Upper Overfire Air
Header Showing Jet Locations
Flyash Reinjection
System
Rear Lower Overfire Air
Header and Air Jets
FIGURE 3-3.
Rear Elevation Drawing Showing Arrangement of Rear Upper and
Lower Overfire Air System, and Flyash Reinjection System -
Test Site G.
16
-------
3.4 MECHANICAL DUST COLLECTOR
The boiler is equipped with a UOP Model 6UPEW HS#10-150 mechanical dust
collector. This collector has 150 tubes of 6-inch diameter.
3.5 TEST PORT LOCATIONS
Emission measurements were made at two locations, at the boiler
outlet and dust collector outlet (stack). The locations of these sample sites
are shown in Figure 3-1, and their geometry is shown in Figure 3-4.
Whenever particulate loading was measured, it was measured simultaneously
at both locations using 24-point traverses. Gaseous measurements of 0 , CO , NO
and hydrocarbons were obtained by pulling samples individually and compositely
from selected ports. SOx measurements, brink and SASS samples for organic and
trace element determinations were each obtained from single points at the boiler
outlet.
3.6 COALS UTILIZIED
The primary coal fired at Test Site G was a 1-1/4 by 1/4 inch modified
stoker coal from the White Ash mine in Paintsville, Kentucky. This coal
averaged 8.05% ash and 12869 Btu/lb based on ten samples obtained by the
test crew.
Two lower ash coals were ordered specifically for the test program.
These included a 1 by 3/8 inch home stoker coal from the Spurlock Mine in
Salisbury, Kentucky, and a 1/2 by 1/8 inch midget stoker coal from the
Wheelwright Mine in Price, Kentucky.
When the 4.4% ash Spurlock coal was fired, difficulties were encountered
maintaining sufficient ash on the grate to prevent overheating and grate
damage. Therefore, testing on this coal was terminated after only two tests.
17
-------
The Wheelwright coal was not fired for fear that its even lower ash content
would cause a similar if not worse problem. The contents of a memo relating
to this problem is given in Appendix A of this report, and may be referred to
for further discussion of the problem.
Because the Wheelwright coal was ruled out, testing on the primary
White Ash coal continued until a suitable alternative was found. Three
carloads of 1-1/2 by 1/4 inch modified stoker coal from the Pevler mine
in Pevler, Kentucky were acquired. This coal contained 7.32% ash and did
not cause problems with the grate.
The average "as-fired" analysis for each of the three coals are presented
in Table 3-3. The individual coal analysis for each test are included in
Section 5.4 of this report. All analyses are based on coal samples obtained by
the test crew during each particulate test or SASS test.
18
-------
1 ' •—
4
4
O
4
__i i__
4
$
o
4
4
__l 4_^_l «^— 1
4 4
O
4 4
0
4 4
i__
4
4
O
4
_^ «—
4
O
4
4
_^ i—
4
D
4
O
4-
mm* !•— •
4
O
4
4
Lr 124.5" ^
i
k
44.5
i
r
CROSS SECTIONAL APEA = 38.47 ft2
BOILER OUTLET SAMPLING PLANE
45"-
CROSS SECTIONAL AREA = 11.04 ft2
DUST COLLECTOR OUTLET SAMPLING PLANE
4» PARTICULATE SAMPLING POINT
Q SASS SAMPLING POINT
Q GASEOUS SAMPLING POINT
S03 SAMPLING POINT
BRINK SAMPLING POINT
FIGURE 3-4. Boiler G Sample Plane Geometry
19
-------
TABLE 3-3
AVERAGE COAL ANALYSIS
TEST SITE G
Proximate (as Rec)
% Moisture
% Ash
% Volatile
% Fired Carbon
Btu/lb
% Sulfur
Ultimate (as Rec)
% Moisture
% Carbon
% Hydrogen
% Nitrogen
% Chlorine
% Sulfur
% Ash
% Oxygen (diff)
White Ash
4.56
8.05
35.19
52.21
12869
0.78
4.27
72.69
4.78
0.98
0.10
0.75
8.32
8.07
Spur lock
3.02
4.42
38.98
53.59
13860
1.31
3.32
74.59
5.11
1.12
0.18
1.31
6.56
7.81
Pevler
4.59
7.32
36.29
51.79
12813
0.76
4.81
72.43
4.90
1.04
0.05
0.69
6.95
9.13
20
-------
4.0 TEST EQUIPMENT AND PROCEDURES
This section details how specific emissions were measured and the
sampling procedures followed to assure that accurate, reliable data were
collected.
4.1 GASEOUS EMISSIONS MEASUREMENTS (NOx, CO, CO?, O;., HC)
A description is given below of the analytical instrumentation, re-
lated equipment, and the gas sampling and conditioning system, all of which
are located in a mobile testing van owned and operated by KVB. The systems
have been developed as a result of testing since 1970, and are operational
and fully checked out.
4.1.1 Analytical Instruments and Related Equipment
The analytical system consists of five instruments and associated
equipment for simultaneously measuring the constituents of flue gas. The
analyzers, recorders, valves, controls, and manifolds are mounted on a panel
in the vehicle. The analyzers are shock mounted to prevent vibration damage.
The flue gas constituents which are measured are oxides of nitrogen (NO, NOx),
carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), and gaseous hydro-
carbons (HC) .
Listed below are the measurement parameters, the analyzer model
furnished, and the range and accuracy of each parameter for the system. A
detailed discussion of each analyzer follows:
Constituent: Nitric Oxide/Total Oxides of Nitrogen (NO/NOx)
Analyzer: Thermo Electron Model 10 Chemiluminescent Analyzer
Range: 0-2.5, 10, 25, 100, 250, 1000, 2500, 10,000 ppm NO
Accuracy: il% 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
21
-------
Constituent: Carbon Dioxide
Analyzer: Beckman Model 864 NDIR Analyzer
Range: 0-5% and 0-20% C02
Accuracy: ±1% of full scale
Constituent: Oxygen
Analyzer: Teledyne Model 326A Fuel Cell Analyzer
Range: 0-5, 10, and 25% O2 full scale
Accuracy: il% of full scale
Constituent: Hydrocarbons
Analyzer: : Beckman Model 402 Flame lonization Analyzer
Range: 5 ppm full scale to 10% full scale
Accuracy: ^1% of full scale
Oxides of nitrogen. The instrument used to monitor oxides of nitrogen
is a Thermo Electron chemiluminescent nitric oxide analyzer. The instrument
operates by measuring the chemiluminescent reaction of NO and 03 to form 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+NO21, the NO2 is first converted to NO. This is accomplished by a
convertar 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. N02 is obtained by the
difference in readings obtained with and without the converter in operation.
Specifications: Accuracy 1% of full scale
Span stability tl% of full scale in 24 hours
Zero stability il ppm in 24 hours
Power requirements 115±10V, 60 Hz, 1000 watts
Response 90% of full scale in 1 sec. (NOx mode),
0.7 sec. NO mode
Output 4-20 ma
22
-------
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. (Note: this instrument was out of service during testing at Site G.)
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 115il5V 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 -1% of full scale in 24 hours
Zero stability ±1% of full scale in 24 hours
Ambient temperature range 32°F to 120°F
Line voltage 115il5V rms
Response 90% of full scale in 0.5 or 2.5 sec.
Precision ±1% of full scale
Output 4-20 ma
23
-------
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 O2 by
volume for operating ranges of 0% to 5%, 0% to 10%, or 0% to 25%.
Specifications: Precision il% of full scale
Response 90% in less than 40 sec.
Sensitivity 1% of low range
Linearity ±1% of full scale
Ambient temperature range 32-125°F
Fuel cell life expectancy 40,000%-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
a circuit. This ionization current is proportional to the concentration of
hydrocarbon atoms which enter the burner. The instrument is available with
range selection from 5 ppm to 10% full scale as CH4.
Specifications: Full scale sensitivity, adjustable from 5 ppm CH^ to
10% CH4
Ranges: Range multiplier switch has 8 positions: XI,
X5, X10, X50, X100, X500, XlOOO, and X5000. In
addition, span control provides continuously variable
adjustment within a dynamic range of 10:1
Response time 90% full scale in 0.5 sec.
Precision ±1% of full scale
Electronic stability ±1% of full scale for successive
identical samples
24
-------
Reproducibility -1% 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 15 to 80 cc/min of pre-mixed
fuel consisting of 40% hydrogen and 60% nitrogen
or helium, supplied at 30 to 200 psig
Electrical power requirements 120V, 60 Hz
Automatic flame-out indication and fuel shut-off valve
4.1.2 Recording Instruments
The output of the four analyzers is displayed on front panel meters
and are simultaneously recorded on a Texas Instrument Model FLO4W6D four-pen
strip chart recorder. The recorder specifications are as follows:
Chart size 9-3/4 inch
Accuracy ±0.25%
Linearity <0.1%
Line voltage 120V±10% at 60 Hz
Span step response: one second
4.1.3 Gas Sampling and Conditioning System
The gas sampling and conditioning system consists of probes, sample
lines, valves, pumps, filters and other components necessary to deliver a
representative, conditioned sample gas to the analytical instrumentation. The
following sections describe the system and its components. The entire gas
sampling and conditioning system shown schematically in Figure 4-1 is con-
tained in the emission test vehicle.
4.1.4 Gaseous Emission Sampling Techniques
Boiler access points for gaseous sampling are selected in the same
sample plane as are particulate sample points. Each probe consists of one-
half inch 316 stainless steel heavy wall tubing. A 100 micrometer Mott Metal-
lurgical Corporation sintered stainless steel filter is attached to each
probe for removal of particulate material.
25
-------
a-
.fi
TK
I .p.
=51
L N
..11
-1 1
'|
I S
^n
p
i
..TH
- 1
'7 ff
T>6
-------
Gas samples to be analyzed for C^, CC^, CO and NO are convoyed to the
KVB mobile laboratory through 3/8 inch nylon sample lines. After passing
through bubblers for flow control, the samples pass through a diaphragm pump
and a refrigerated dryer to reduce the sample dew point temperature to 35°F.
After the dryer, the sample gas is split between the various continuous gas
monitors for analysis. Flow through each continuous monitor is accurately
controlled witli rotometers. Excess flow is vented to the outside. Gas samples
may be drawn both individually and/or compositely from all probes during each
test. The average emission values are reported in this report.
4.2 SULFUR OXIDES (SOx) MEASUREMENT AND PROCEDURES
Measurement of SO2 and SO-^ concentrations is made by wet chemical
analysis using both the "Shell-Emeryville" method and EPA Method 6. In the
Shell-Emeryville method the gas sample is drawn from the stack through a
glass probe (Figure 4-2), containing a quartz wool filter to remove particu-
late matter, into a system of three sintered glass plate absorbers (Figure 4-3)
The first two absorbers contain aqueous isopropyl alcohol and remove the sul-
fur trioxide; the third contains aqueous hydrogen peroxide solution which
absorbs the sulfur dioxide. Some of the sulfur trioxide is removed by the
first absorber, while the remainder, which passes through as sulfuric acid
mist, is completely removed by the secondary absorber mounted above the first.
After the gas sample has passed through the absorbers, the gas train is purged
with nitrogen to transfer sulfur dioxide, which has dissolved in the first
two absorbers, to the third absorber to complete the separation of the two
components. The isopropyl alcohol is used to inhibit the oxidation of sulfur
dioxide to sulfur trioxide before it gets to the third absorber.
The isopropyl alcohol absorber solutions are combined and the sulfate
resulting from the sulfur trioxide absorption is titrated with standard lead
perchlorate solution using Sulfonazo III indicator. In a similar manner, the
hydrogen peroxide solution is titrated for the sulfate resulting from the
sulfur dioxide absorption.
The gas sample is drawn from the flue by a single probe made of
quartz glass inserted into the duct approximately one-third to one-half way.
27
-------
Flue Wall
Asbestos Plug
Ball Joint
Support Tube
Insulation
vycor
Sample Probe
Heating
Tape
Pryometer
and
Thermocouple
Figure 4-2. SOx Sample Probe Construction
Spray Trap
Dial Thermometer
Pressure Gauge
Volume Indie
Vapor Trap Diaphragm
Pump-
Dry Test Meter
Figure 4-3.
Sulfur Oxides Sampling Train
(Shell-Emeryville)
28
-------
The inlet end of the probe holds a quartz wool filter to remove particulate
matter. It is important that the entire probe temperature be kept above
the dew point of sulfuric acid during sampling (minimum temperature of
260°C). This is accomplished by wrapping the probe with a heating tape.
EPA Method 6, which is an alternative method for determining SC>2
(Figure 4-4), employs an impinger train consisting of a bubbler and three
midget impingers. The bubbler contains isopropanol. The first and second
impingers contain aqueous hydrogen peroxide. The third impinger is left dry.
The quartz probe and filter used in the Shell-Emeryville method is also used
in Method 6.
Method 6 differs from Shell-Emeryville in that Method 6 requires
that the sample rate be proportional to stack gas velocity. Method 6 also
differs from Shell-Emeryville in that the sample train in Method 6 is purged
with ambient air, instead of nitrogen. Sample recovery involves combining
the solutions from the first and second impingers. A 10 ml aliquot of
this solution is then titrated with standardized barium perchlorate.
Two repetitions of Shell-Emeryville and two reptitions of EPA
Method 6 were made during each test.
4.3 PARTICULATE MEASUREMENT AND PROCEDURES
Particulate samples are taken at the same sample ports as the gaseous
emission samples using a Joy Manufacturing Company portable effluent sampler
(Figure 4-5). This system, which meets the EPA design specifications for
Test Method 5, Determination of Particulate Emissions from Stationary Sources
(Federal Register, Volume 36, No. 27, page 24888, December 23, 1971), is used
to perform both the initial velocity traverse and the particulate sample
collection. Dry particulates are collected in a heated case using first a
cyclone to separate particles larger than five micrometers and a 100 mm glass
fiber filter for retention of particles down to 0.3 micrometers. Condensible
particulates are collected in a train of four Greenburg-Smith impingers in an
ice water bath. The control unit includes a total gas meter and thermocouple
indicator. A pitot tube system is provided for setting sample flows to obtain
isokinetic sampling conditions.
29
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PROBE (END PACKED'
WITH QUARTZ OR
PYREX WOOL)
STACK WALL
MIDGET IMPINGERS
THERMOMETER
MIDGET BUBBLER
GLASS WOOL
SILICA GEL
DRYING TUBE
ICE BATH
THERMOMETER
o <*. -», 11
o ii;
u |||
NEEDLE VALVE
SURGE TANK
FIGURE 4-4. EPA Method 6 Sulfur Oxide Sampling Train
PUMP
30
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TEMPERATURE SENSOR
IMPINGER TRAIN OPTIONAL,MAY BE REPLACED
BY AN EQUIVALENT CONDENSER
REVERSETYPE
PITOTTUBE
VACUUM
GAUGE
THERMOMETERS
MAIN VALVE
DRY GAS METER
AIRTIGHT
PUMP
VACUUM
LINE
THERMOMETER
FILTERHOLOER
PITOT MANOMETER
ORIFICE
FIGURE 4-5. EPA Method 5 Particulate Sampling Train
31
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All peripheral equipment is carried in the instrument van. This
includes a scale (accurate to to.I mg), hot plate, drying oven (212°F), high
temperature oven, desiccator, and related glassware. A particulate analysis
laboratory is set up in the vicinity of the boiler in a vibration-free area.
Here filters are prepared, tare weighed and weighed again after particulate
collection. Also, probe washes are evaporated and weighed in the lab.
4.4 PARTICLE SIZE DISTRIBUTION MEASUREMENT AND PROCEDURES
Particle size distribution is measured using several methods. These
include the Brink Cascade Impactor, SASS cyclones, and 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 CO.3 to 3.0 micrometers) and its small sample
nozzle (J..5 to 2.0 mm maximum diameter) . Both are inadequate for the job at
hand. The particles being collected at the boiler outlet are often as large
as the sample nozzle.
The sampling procedure is straight forward. First, the gas velocity
at the sample point is determined using a calibrated S-type pitot tube. For
this purpose a hand held particulate probe, inclined manometer, thermocouple
and indicator are used. Second, a nozzle size is selected which will main-
tain isokinetic flow rates within the recommended .02-.07 ftVmin rate at
stack conditions. Having selected a nozzle and determined the 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,
32
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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 rag. A schematic of the Brink sampling train is shown in Figure 4-6.
Banco. The Bahco classifier is described in ASME 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 G came from
the cyclone in the EPA Method 5 particulate train. These samples are spatially
representative because they are taken from a 24-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
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 4.9.
4.5" COAL SAMPLING AND ANALYSIS PROCEDURE
Coal samples at Test Site G were taken during each test from the
units three observation ports immediately above the feeders. The samples
were processed and analyzed for both size consistency and chemical composition.
Normally coal samples would be taken off the apron of the coal scale feeders,
but there were no coal scales at Site G. The observation ports above the
feeders were used because they are close enough to the furnace that the
coal sampled simultaneously with testing is representative of the coal fired
during the testing.
33
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PRESSURE TAP
FOR 0-20"
MAGNAHELIX
CYCLONE
STAGE 1
STAGE 2
STAGE 3
STAGE 4
STAGE 5
FINAL FILTER
EXHAUST
ELECTRICALLY HEATED PROBE
DRY GAS
METER
FLOW CONTROL
VALVE
DRYING
COLUMN
FIGURE 4-6. Brink Cascade Impactor Sampling Train
34
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Representative samples were obtained by first purging the ports of
clogged coal and then lifting the ports allowing 10 to 20 pounds of coal
to flow into a rectangular bucket. This was done from one of the ports
at the start of testing, and once more from each of the other two ports
during the test, (three-to-five hours duration), so that a three-increment
sample was obtained. The samples were then riffled using a Gilson Model
SP-2 Porta Splitter until two representative twenty-pound samples were ob-
tained.
The sample to be used for sieve analysis is weighed, air dried over-
night, and re-weighed. Drying of the coal is necessary for good separation
of fines. If the coal is wet, fines cling to the larger pieces of coal and
to each other. Once dry, the coal is sized using a six tray Gilson Model
PS-3 Porta Screen. Screen sizes used are 1", 1/2", 1/4", #8 and #16 mesh.
Screen area per tray is 14"xl4". The coal in each tray is weighed on a
triple beam balance to the nearest 0.1 gram.
The coal sample for chemical analysis is reduced to 2-3 pounds by
further riffling and sealed in a plastic bag. All coal samples are sent to
Commercial Testing and Engineering Company, South Holland, Illinois. Each
sample associated with a particulate loading or particle sizing test is
given a proximate analysis. In addition, composite samples consisting of
one increment of coal for each test for each coal type receive ultimate
analysis, ash fusion temperature, mineral analysis, Hardgrove grindability
and free swelling index measurements.
4.6 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
35
-------
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 G the bottom ash samples were collected in several in-
crements from the discharge end of 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 dust collector hopper. These samples,
approximately one quart in size, were sent to Commercial Testing and Engineering
Company for combustible determination.
4.7 BOILER EFFICIENCY EVALUATION
Boiler efficiency is calculated using the ASME Test Form for Abbre-
viated Efficiency Test, Revised, September, 1965. The general approach to
efficiency evaluation is based on the assessment of combustion losses. These
losses can be grouped into three major categories: stack gas losses, com-
bustible losses, and radiation losses. The first two groups of losses are
measured directly. The third is estimated from the ABMA standard Radiation
Loss Chart.
Unlike the ASME test in which combustible losses are lumped into one
category, combustible losses are calculated and reported separately for com-
bustibles in the bottom ash, 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 (5ASS) train for the collection of particulate and volatile matter
36
-------
in addition to gaseous samples (Figure 4-7). The "catch" from the SASS
train is analyzed for polynuclear aromatic hydrocarbons (PAH) and inorganic
trace elements.
In this system, a stainless steel heated probe is connected to an
oven module containing three cyclones and a filter. Size fractionation is
accomplished in the series cyclone portion of the SASS train, which incor-
porates the cyclones in series to provide large quantities of particulate
matter which are classified by size into three ranges:
A) >10 ym 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.
37
-------
U)
oo
Convection
oven
Filter
Gas cooler
Gas
.temperature
T.C.
Stack velocity (&P)
magnehellc gauges
Sorbent
cartridge
trace element
collector
Impinge r
T.C.
Coarse adjustment
F1ne v»1ve
adjustment
valve Qr \ (\
Vacuum pumps
Vacuum
gage
Orifice AH1
magnehellc gauqe
Dry test meter
FIGURE 4-7. Source Assessment Sampling System (SASS) Sampling Train
-------
5^.0 TEST RESULTS AND OBSERVATIONS
This section of the report presents the results of tests performed
on Boiler G. Observations are made regarding the influence on gaseous and
particulate emissions and on boiler efficiency as the control parameters
were varied. Twenty-six tests were conducted over a six-week test period
to develop these data. Reference may be made to the Emission Data Summary,
Table 2-2, in the Executive Summary and to Tables 5-28 through 5-31 at the
end of this section when reading through the following discussion. Please
note that carbon monoxide (CO) data is absent in this report due to the CO
analyzer being out of service.
5.1 OVERFIRE AIR
Boiler G had a standard overfire air (OFA) configuration consisting
of two rows of jets on the rear water wall and one row of the front water
wall above the feeders. The detailed geometry of the overfire air system
is described in Section 3.2. Air flow to each row of overfire air jets was
controlled by a system of butterfly valves.
Two test sets were run in which overfire air pressure (and thus
overfire air flow) was the independent variable. The test results, described
in this section, indicate that the overfire air variations examined had little
effect on emissions or efficiency. Table 5-1 summarizes the overfire air
test data.
Tests were also run to determine the overfire air flow rate as a
function of static pressure in the overfire air headers. These tests
indicate that overfire air supplies 10% of the combustion air on Boiler G at
full load.
5.1.1 Particulate Loading vs Overfire Air
Particulate loading was not affected by a reduction in overfire air
pressure. The test data, shown in Table 5-2, show conflicting trends for the
two test sets. This is interpreted to be the result of normal variation (or
scatter) in the emission level and is unrelated to the overfire air change.
39
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TABLE 5-1
EFFECT OF OVERFIRE AIR ON EMISSIONS AND EFFICIENCY
TEST SITE G
TEST NO. 2 3 23 24
Base Base
Description line Low line Low
OFA OFA OFA OFA
OVERFIRE AIR CONDITIONS
Front Upper, "H2O 23 18 19 12
Rear Upper, "H2O 23 13 19 12
Rear Lower, "H2O 23 12 19 12
FIRING CONDITIONS
Load, % of Capacity 85 80 76 78
Grate Heat Release, 103Btu/hr-ft2 695 651 618 639
Coal White Ash White Ash Pevler Pevler
Coal Fines, % Passing 1/4" 40 31 32 32
Excess Air, % 69 67 58 51
BOILER OUTLET EMISSIONS
Particulate Loading, Ibs/lO^tu 4.27 4.33 4.57 4.00
Combustible Loading, Ibs/lO^tu 2.48 2.26 2.31 2.52
Inorganic Ash Loading, lbs/106Btu 1.79 2.07 2.26 1.48
Combustibles in Flyash, % 58.1 52.2 50.6 62.9
02, % (dry) 8.9 8.7 8.0 7.3
C02, % (dry) 10.2 10.5 11.2 11.7
NO, Ibs/lO^Btu .435 .515 .573 .456
MECHANICAL COLLECTOR OUT EMISSIONS
Particulate Loading, Ibs/lO^tu 0.22 0.22 0.32 0.26
Combustible Loading, lbs/106Btu — 0.06 0.09 0.08
Inorganic Ash Loading, lbs/106Btu — 0.16 0.23 0.18
Combustibles in Flyash, % — 29.1 28.8 30.2
Mechanical Collector Efficiency, % 94.8 94.9 93.0 93.5
HEAT LOSSES, %
Dry Gas 14.74 13.35 12.95 11.94
Moisture in Fuel 0.45 0.41 0.44 0.38
H2O from Combustion of H2 4.22 4.00 4.26 4.19
Combustibles in Flyash 3.54 3.22 3.29 3.59
Combustibles in Bottom Ash 1.16 0.27 0.71 0.75
Radiation 0.62 0.66 0.69 0.67
Unmeasured 1.50 1.50 1.50 1.50
Total Losses 26.23 23.41 23.84 23.02
Boiler Efficiency 73>77 76>59 76>16 J6^Q
40
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Test
No.
2
3
23
24
TABLE 5-2
PARTICULATE LOADING VS OVERFIRE AIR
Boiler Outlet Mechanical Collector Outlet
Particulate Loading Particulate Loading
Overfire Air lbs/106Btu lbs/106Btu
Baseline
Low
Baseline
Low
4.27
4.33
4.57
4.00
0.22
0.22
0.32
0.26
5.1.2 Nitric Oxide vs Overfire Air
The nitric oxide (NO) data from the two test sets indicate that
nitric oxide was not significantly affected by a reduction in overfire air
pressure. The test data, shown in Table 5-3, shows a 24% increase in NO
for the first test set and a 13% decrease in NO for the second test set
based on corrected NO concentrations. These deviations are interpreted as
normal data scatter and unrelated to the overfire air pressure change.
The nitric oxide correction to 8% O2 shown in Table 5-3 is based on
the average NO vs O2 relationship plotted in Figure 5- 11. This plot shows
that NO increases 0.046 lbs/10 Btu for each one percent increase in O2. This
correction removes the effects of the variable oxygen from the test results.
TABLE 5-3
NITRIC OXIDE VS OVERFIRE AIR
Test
No.
2
3
23
24
Overfire Air
Baseline
Low
Baseline
Low
8.9
8.7
8.0
7.3
Measured
Nitric Oxide
lbs/106Btu
0.435
0.515
0.573
0.456
. Nitric Oxide
Corrected to 8% 02
lbs/106Btu
0.394
0.483
0.573
0.488
41
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5.1.3 Boiler Efficiency vs Overfire Air
Boiler efficiency increased when overfire air pressure was reduced
in both test sets. However, the efficiency increase appears to be the re-
sult of factors other than overfire air. For example, in the first test
set a measured 2.82% efficiency increase resulted primarily from a 1.39%
decrease in dry gas loss and a 0.89% decrease in bottom ash combustible
loss (Table 5-1). Both of these heat loss changes are thought to have re-
sulted from factors other than overfire air. In the second test set a
measured 0.82% efficiency gain resulted primarily from a 1.01% decrease in
dry gas loss.
The heat loss of primary interest when overfire air is changed is the
loss due to combustibles in the flyash. As shown in Table 5-4, this loss did
not change significantly in these tests.
TABLE 5-4
BOILER EFFICIENCY VS OVERFIRE AIR
Boiler
Efficiency, %
73.77
76.59
76.16
76.98
5.1.4 Overfire Air Flow Rate
The rate at which air is injected into the furnace above the grate
was measured using a standard pitot tube traverse of the overfire air system.
The locations at which these measurements were made are shown in the overfire
air system schematic, Figure 5-1.
These measurements were made for two reasons. First, by making the
measurements at two overfire air settings, it was possible to relate overfire
Test
No.
2
3
23
24
Overfire Air
Baseline
Low
Baseline
Low
Heat Loss Due to
Comb, in Flyash, %
3.54
3.22
3.29
3.59
42
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FIGURE 5-1.
Schematic of Overfire Air System Showing Location
of Flow Rate Measurements - Itest Site G
a - Front Lower Overfire Air
b - Rear Main Overfire Air
c - Rear Upper Overfire Air
d - Real Lower Overfire Air
43
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air flow in Ibs/hr to the overfire air pressure. Since the overfire air
pressure was measured during each test on the boiler, this relationship
allows overfire air flow to be accurately estimated for each test. The
second reason for making these measurements was to determine the percentage
of combustion air introduced above the grate as opposed to that introduced
through the grate.
The test results are shown in Table 5-5. it is significant to note
that 85% of the overfire air is introduced through the rear water wall on
this boiler. The remaining 15% is introduced through the front water wall.
Of the air introduced through the rear water wall, 41% went to the upper
rear overfire air jets, 31% went to the lower rear overfire air jets and 28%
was used in the pneumatic flyash reinjection lines.
In general, the overfire air test data was good considering the
difficulties in measuring -turbulent gas flows. Maximum OFA Tests 14 and
15 were -taken under nearly identical conditions and gave nearly identical
results. Test 21 was taken at reduced overfire air pressures and, with the
exception of the rear lower OFA measurement, gave the expected reduction in
flow rate.
The relationship between overfire air flow rate and overfire air
pressure is given in Figure 5-2. Bernoulli's equation for fluid flow through
an orifice predicts that flow rate will be proportional to the square root of
the pressure drop. This relationship and the maximum overfire air test data
were used to create Figure 5-2. With this set of curves it is possible to
estimate overfire air flow through each of the three rows of overfire air
jets and the flyash reinjection lines by knowing only the static pressure in
the duct.
The overfire air system supplies 8% of the total combustion air
at full load and 8% Oj. This conclusion is based on calculations indicating
that 176,000 Ibs/hr air are used to burn coal at 8% Q^, and full load, where
the overfire air system on this unit is normally operated wide open at full
load and introduces about 14,130 Ibs/hr air to the furnace.
44
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TABLE 5-5
OVERFIRE AIR AND REINJECTION AIR FLOW RATES
TEST SITE G
HIGH OVERFIRE AIR PRESSURE, TEST NO. 13
Pressure Air Flow
Main Duct "H2O Ib/hr Split
Branch Duct
Pressure Air Flow Split
"H?O Ib/hr Rear Only
Front OFA
Rear OFA
20 2,084 15%
22 12,055 85% Rear Upper OFA
Rear Lower OFA
Reinj (by diff)
22
21
—
4,963
3,696
3,396
41%
31%
28%
HIGH OVERFIRE AIR PRESSURE, TEST NO. 14
Pressure Air Flow
Main Duct "H20 Ib/hr Split
Branch Duct
Pressure Air Flow Split
"H2O Ib/hr Rear Only
Front OFA
Rear OFA
21 2,238 16%
23 11,878 84% Rear Upper OFA
Rear Lower OFA
Reinj (by diff)
23
21
—
4,840
3,752
3,286
41%
31%
28%
MEDIUM OVERFIRE AIR PRESSURE, TEST NO. 21
Pressure Air Flow
Main Duct "H2O Ib/hr Split
Branch Duct
Pressure Air Flow Split
"H2O Ib/hr Rear Only
Front OFA
Rear OFA
13 1,919 15%
16 10,678 85% Rear Upper OFA
Rear Lower OFA
Reinj (by diff)
15
13
—
3,474
3,758
3,446
33%
35%
32%
45
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ON
)
CO
B
ca
1234
OVERFIRE AIR FLOW RATE, Ibs/hr x 103
FIGURE 5-2.
Overfire Air Flow Rate as a Function of Static Pressure.
Relationship is Based on Data From Tests 13 and 14, and
on Bernoulli's Equation for Fluid Flow Through an OrifiCe
46
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5.2 FLYASH REINJECTION
Boiler G does not reinject flyash from the mechanical dust collector
or from the economizer hopper. However, it does reinject flyash pneumatically
and continuously from the boiler hopper. During one test, Test 17, the
boiler hopper ash was diverted into barrels rather than reinjected. This
resulted in a 14% drop in particulate mass loading at the boiler outlet,
and a 33% increase in particulate mass loading at the mechanical collector
outlet. The data are shown in Table 5-6.
TABLE 5-6
PARTICULATE LOADING VS FLYASH REINJECTION
Test
No.
5
17
Reinjection from
Boiler Hopper
Yes
No
Test Conditions
% Load % Oy
102 7.0
98 7.4
"OFA
22
21
Boiler Out
Particulate
lbs/106Btu
6.79
5.86
Mech Coll Out
Particulate
lbs/106Btu
0.27
0.36
The 14% drop in particulate emissions at the boiler outlet is small,
but is believed to be a result of the stopped reinjection. Some reduction in
particulate emissions was expected. On the other hand, the increased
particulate loading at the mechanical collector outlet was not expected and
could be due to other factors relating to the collection efficiency of the
mechanical dust collector.
The collection rate of the boiler hopper ash was not measured directly
but can be deduced from the differences in boiler outlet dust loadings of
Tests 5 and 17. By this method, it is estimated that the flyash collection
rate is about 0.92 lbs/106Btu. With a measured combustible fraction of 0.833,
this represents a potential efficiency gain of 1.1%.
Table 5-7 lists the combustible heat losses and boiler efficiency for
the flyash reinjection tost set.
47
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TABLE 5-7
BOILER EFFICIENCY VS FLYASH REINJKCTION
Test
No.
5
17
Reinjection from
Boiler Hopper
Yes
No
% Com!
Blr
Hpr
—
83.3
justible;
D.C.
Hpr
49.9
57.3
J in At;h
Bottom
Ash
G . 9 3
7.34
'A Heat
Flyash
4.81
5.45
Loss
Bottom
Ash
0.52
0. 32
Boiler
Ef f icienc'
74.12
73.77
5.3 EXCESS OXYGEN AND GRATE HEAT RELEASE
The boiler at Test Site G was tested for emissions and boiler efficien
at loads ranging from 17% to 102% of the unit's design capacity. At the
higher loads, the excess air was varied over a wide range. This section pro-
files the various emissions and boiler efficiency as a function of these two
variables.
Boiler steam loading is expressed in terms of grate heat release. A-t-
full load, the measured grate heat release on this unit averaged 809,000 Btu/
hr-ft2 grate area. Excess air is expressed in terms of percent oxygen in the
flue gas at the boiler outlet.
It is of special interest to note that some tests were run under
swing load conditions while others were run under steady load conditions Th
two types of tests are differentiated on many of the plots. The three coals
fired are also differentiated on many of the plots.
5.3.1 Excess Oxygen Operating Levels
Figure 5-3 depicts the various conditions of grate heat release and
excess oxygen under which tests were run on the boiler at Site G. Different
symbols are used to distinguish between the three coals fired.
Full design capacity was easily met on this unit without significant
deterioration in combustion efficiency. At full capacity the unit was
48
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( )
>-
DC
O
O
UJ
O
oc o
UJ O
O
O
00
X
o
co
0
•i
€>
150.0 300.0 450.0 600.0 750.0
GRRTE HERT RELERSE 1000 BTU/HR-SQ FT
O I WHITE RSH -j- : SPURLOCK
FIG. 5-3
OXYGEN
TEST SITE G
'• PEVLER
VS. GRRTE HERT RELERSE
THIS PLOT SHOWS THE RANGE IN OXYGEN LEVEL UNDER WHICH TESTS WERE CONDUCTED
SHADED AREA ENCOMPASSES ALL OF THE PARTICULATE TESTS. THE LOW Oo TESTS
BELOW THE SHADED AREA WERE SHORT DURATION GASEOUS TESTS.
-------
operated at oxygen levels as low as 7'i, (48% excess air) without problems
for periods of up to four hours. The unit was operated at. lower oxyqon
levels for shorter periods of time including one test (Test 2rxi) at 4.1%
02 (22% excess air). The manufacturer's design performance? summary sheet
for this unit specifies 31% excess air at full load.
Most of the test data was obtained above a grate heat release of
600,000 Btu/hr-ft2, or 75% of design capacity. However, three tests were
also run at a grate heat release of 135,000 Btu/hr-ft2, or 17% of design
capacity. At this low load the excess oxygen averaged 15% which is equiva-
lent to 225% excess air.
5.3.2 Particulate Loading vs Grate Heat Release
Figure 5-4 profiles the particulate loading at the boiler outlet as
a function of grate heat release. Different symbols are used for the three
coals fired, and special test conditions are identified with labels.
Swing load conditions increased particulate loading when firing
white ash coal. Swing load Tests 4 and 10 averaged 60% higher particulate
emissions than base fired Tests 2 and 3. When firing Pevler coal, however,
the swing load Test 22 gave a particulate loading which was similar to the
base fired Tests 23 and 24.
Boiler outlet particulate loading increased as grate heat release
increased. When firing White Ash coal, particulate loading tripled between
135,000 and 809,000 Btu/hr-ft2 (17% and 100% capacity). At full load, boiler
outlet particulate loading averaged 5.09 lbs/10 Btu and ranged from a low of
2.93 lb3/106Btu for Spurlock coal to a high of 6.79 lbs/10 Btu for White Ash
coal.
The effects of coal properties are discussed in a later section but
it is worth noting here that the low ash Spurlock coal (4.4% ash) had signifi-
cantly lower full load particulate emissions than either of the other two
coals *8.1% and 7.3% ash).
The average ash carryover was 41% for all tests except the three low
load tests which averaged 25% ash carryover. The percentage of coal ash carried
over as flyash did vary from coal to coal. Table 5-8 shows the basis for this
determination.
50
-------
o
o
DO
O
O
O
00
-v. O
DQ O
o_
o
cc
LU
o
DO
o
o
0
REDUCED REINJECTION TEST
SWING LOAD TESTS
LOW OFA TESTS
150.0 300.0 450.0 600.0 750.0
GRflTE HERT RELERSE 1000 BTU/HR-SQ FT
0 : WHITE flSH + : SPURLOCK
FIG. 5-4
BOILER OUT PRRT.
TEST SITE G
'• PEVLER
VS. GRRTE HERT RELERSE
51
-------
TABLE 5-H
ASH CARRYOVER VS COAL TYPE
Average Ash Average A.sh
Content of Coal Content of Flyash Average Ash
Coal lbs/106Btu lhs/]QGBtu __ Carryover, %
White Ash 6.27 2.66 42.4
Spurlock 3.07 1.54 50.2
Pevler 5.97 2.02 33-8
Particulate loadings were measured at the mechanical collector out-
let simultaneously with each of the fifteen boiler outlet particulate loadinq
determinations. These data are shown in Figure 5-5 as a function of grate
heat release. Again, the data are identified by coal and special tests are
labeled.
The mechanical collector outlet particulate loadings are highest at
low load as a result of a significant drop in collector efficiency. Mechanical
collector efficiency is discussed in another section.
Some of the trends observed at the boiler outlet are still evident
Swing load particulate loadings average higher than base load particulate
loadings. Also, the high load Spurlock coal test gives the lowest particulat
loading. At full load the collector outlet particulate loading averaged
0.28 lbs/10%tu and ranged in value from a low of 0.17 lbs/l06Btu to a high of
0.36 lbs/106Btu.
5.3.3 Nitrogen Oxides vs Oxygen and Grate Heat Release
Nitric oxide (NO) and nitrogen dioxide (NO2) 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 units
have been converted from ppm to lbs/106Btu in this report so that they can be
more easily compared with existing and proposed emission standards. Table 2-2
52
-------
CD
O
O
O
O
O
O
00 _|
03 O
_J O
CD
OC
cn
Q_
o
I?
O
CJ
o
o
(\J-|
0
m
~r ~T- ~r ~T- nr
150.0 300.0 450.0 600.0 750.0
GRRTE HERT RELERSE 1000 BTU/HR-SQ FT
O : WHITE nsH + : SPURLOCK
FIG. 5-5
DUST COLL. OUT PRRT
TEST SITE G
: PEVLER
VS. GRRTE HERT RELERSE
-------
in the Executive Summary lists the nitric oxide data in units of ppm for the
convenience of those who prefer these units.
Nitrogen dioxide CNC^) emissions are not discussed in this section
because measurable concentrations were not present. As shown in Table 2-1
of the Executive Summary, only 2 of 22 NC>2 readings were above 0.0 ppm.
Figure 5-6 presents the nitric oxide data as a function of grate
heat release under the various excess air conditions encountered during
testing. The average nitric oxide emissions are invarient with load.
Nitric oxide concentrations are known to increase with load at con-
stant excess air. However, excess air is decreasing with increasing load" on
this boiler and effectively cancels out the effects of load (flame temperature)
on the nitric oxide emissions. Table 5-9 shows the average nitric oxide
emissions for three load ranges.
TABLE 5-9
AVERAGE NITRIC OXIDE CONCENTRATIONS VS LOAD
Nitric Oxide Nitric Oxide
% O-> lbs/10 Btu ppm @ 3% O?
100% Load
80% Load
17% Load
6.2
8.0
15.0
0.488
0.516
0.513
360
379
379
Figure 5-7 presents the nitric oxide data as a function of oxygen in
the flue gas at three grate heat release ranges. The figure shows nitric
oxide concentration increasing with increasing oxygen and with increasing grate
heat release.
The nitric oxide data in each grate heat release range (load range)
are plotted versus oxygen on an expanded scale in Figures 5-8, 5-9 and 5-10.
In each of these plots a trend line was determined by linear regression
analysis. The three trend lines are combined in Figure 5-11 to form a nitric
54
-------
CD
O
O
O
O
O
O
00
O
§
UJ
O
I—I
X
O
LJ
t—I
cc
O
O
o
O
CM
0
80%
CAPACITY
100%
CAPACITY
17%
CAPACITY
T
T
T
150.0 300.0 450.0 600.0 750.0
GRflTE HERT RELERSE 1000 BTU/HR-SQ FT
(T) : WHITE RSH + Z SPURLOCK
FIG. 5-6
NITRIC OXIDE
TEST SITE G
; PEVLER
VS. GRflTE HEflT RELERSE
55
-------
O
O
O
m o
•ZL °
o °°
"v. O
CD O
_J CD
O
i — i
X
O
a:
O
O
(\J _
0
x
6.00 8.00 10.00 12.00
OXYGEN PERCENT DRY
14.00
: 129-142GHR X '• 469-591GHR + : B18-7I5GHR
: 794-831GHR
FIG. 5-7
NITRIC OXIDE
TEST SITE G
VS. OXYGEN
56
-------
o
o
LO
CO
e CD-I
^ S
3 S
o
o
uJ en
§
l/M
100% CAPACITY TESTS
0
^TT I
6.00
OXYGEN
0 ; 7M-831GHR
FIG. 5-8
NITRIC OXIDE
TEST SITE G
8.00
10.00 12.00
PERCENT DRY
14.00
VS. OXYGEN
TREND LINE DETERMINED BY LINEAR REGRESSION ANALYSIS.
CORRELATION COEFFICIENT r = 0.75
SLOPE = 0.042,
57
-------
00
o
o
in
r-*
o
o
CD
\ O
OQ O
_i in
o
o
UJ
CD
I— I
X
o
80% CAPACITY TESTS
J-J-
T
T
0
6.00
OXYGEN
+ : 618-715GWI
FIG. 5-9
NITRIC OXIDE
TEST SITE G
8.00
10.00 12.00
PERCENT DRY
—I
14.00
VS. OXYGEN
TREND LINE DETERMINED BY LINEAR REGRESSION ANALYSIS. SLOPE = 0.047,
CORRELATION COEFFICIENT r = 0.78
58
-------
CD
o
o
LO
o
o
o
CD
S
o
o
UJ (D
X
O
17% CAPACITY TESTS
J-J-
o
6.00
OXYGEN
A : 129-142GHR
FIG. 5-10
NITRIC OXIDE
TEST SITE G
8.00
10.00 12.00
PERCENT DRY
14.00
VS. OXYGEN
TREND LINE DETERMINED BY LINEAR REGRESSION ANALYSIS. SLOPE = 0.058,
CORRELATION COEFFICIENT r = 0.99
59
-------
o
o
in
\ O
CD O
_i in
o
o
°
X
O
0 S
in
J-L.
~T 1 1
8.00 10.00 12.00
PERCENT DRY
0
6.00
OXYGEN
O : TflEW LIME
FIG. 5-11
NITRIC OXIDE
TEST SITE G
VS. OXYGEN
14.00
60
-------
oxide trend line plot which could be used for predicting nitric oxide con-
centrations on the unit. The slope of these trend lines indicate that nitric
oxide increases by 0.058 lbs/10^Btu for each one percent increase in oxygen
on this unit.
5.3.4 Hydrocarbons vs Oxygen and Grate Beat Release
Unburned hydrocarbons (HC) were measured during Tests 11 and 12
with a heated sample line and a continuous monitoring instrument utilizing
the flame ionization method of detection. The data are plotted as a function
of grate heat release in Figure 5-12; and as a function of oxygen in Figure
5-13.
Hydrocarbon concentrations decreased with load, averaging 38 ppm
at 100% load and 22 ppm at 80% load. Hydrocarbon concentrations decreased
with increasing excess oxygen at 80% load but showed no trend at 100% load.
5.3.5 Combustibles in the Ash vs Oxygen and Grate Heat Release
Flyash samples collected at the boiler outlet, mechanical collector
outlet and mechanical collector hopper were baked in a high temperature oven
for determination of combustible content. Bottom ash samples were also pro-
cessed in this manner. The test data for each of these sample locations are
plotted as a function of grate heat release in Figures 5-14, 5-15, 5-16 and
5-17.
In general, combustible content of the bottom ash and boiler outlet
flyash was higher at high loads than at low loads. All trends with grate
heat release (load) are slight.
Combustibles in the ash did not vary as a function of oxygen. This
relationship is not shown in any figures in this report, but it was examined
and no relationship was found.
61
-------
8
LU
O
E
Q_
CO
x: o
o_ o
Q_
o
CO
o
o
o
CD
QC
CE
CJ
CD
O
O
|2
100%
CAPACITY
80%
CAPACITY
T
T
T
T
0
150.0 300.0 450.0 600.0 750.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
O • UNITE RSH + : SPURLOCX
FIG. 5-12
HYDROCflRBONS
TEST SITE G
VS. GRflTE HEflT RELEflSE
62
-------
o
CM 0
0 ._
z m
LU
O
£ g
£ °_
« S
cc
z: CD
Q_ 0
/* •
°- d-
00
o
o
CD d "
~^P /v 1
0 ^
CO
cc
§§
I2"
O 0 ® * 100% CAPACITY
0
,.
~> ^ L
r- < 80% CAPACITY
^^i
+
^^
/ / 1 1 1 1 1
0 6.00 8.00 10.00 12.00 14.00
OXYGEN PERCENT DRY
: 637 GHR
; 803 GHR
FIG. 5-13
HYDROCRRBONS
TEST SITE G
VS. OXYGEN
63
-------
CD-
CD
O
•
O _
CO
_
QC O
LU
Q_ 0_
CD
CJ
en
cr
o
CO
o
o _
CM
+
0
150.0 300.0 450.0 600.0 750.0
GRflTE HEflT RELEflSE 1000 BTU/HR-SQ FT
O • MWTE RSH -f- : SPUFLOCK
FIG. 5-14
BOTTOM flSH COMB.
TEST SITE G
VS. GRflTE HEflT RELEflSE
64
-------
o
CD-J
O
o
00
UJ
CO O
2_ •
o o
CJ <«-
o
cc
O
CD
CM
T
T
0
150.0 300.0 450.0 600.0 750.0
GRRTE HERT RELERSE 1000 BTU/HR-SQ FT
0 : WHITE flSH + : SPURLOCK
FIG. 5-15
BOILER OUT COMB.
TEST SITE G
m. PEVLER
VS. GRRTE HERT RELERSE
65
-------
o
•
o
o
o
00
Lcl
OC
LU
Q_
CD
O
O
CD
(_)
cn
ZD
Q
1 - 1 - 1 - 1 - 1 -
150.0 300.0 450.0 600.0 750.0
GRRTE HEflT RELEflSE 1000 BTU/HR-SQ FT
0
O : UNITE RSH + : SPURLOCK
FIG. 5-16
DUST COLL. OUT COMB.
TEST SITE G
" PEVLER
VS. GRflTE HEflT RELEflSE
66
-------
LU
CD
O
O
•
O
CO
o
s-1
g
CD
<_> o
I *
CJ
CC
<-> O
•
( i CD
*—' (NS|
0
O
150.0 300.0 450.0 600.0 750.0
GRflTE HEflT RELERSE 1000 BTU/HR-SQ FT '
O : WHITE flSH + ; SPURLOCK
FIG. 5-17
D. C. CRTCH COMB.
TEST SITE G
; PEVLER
VS. GRflTE HERT RELERSE
67
-------
Coal properties did affect combustible levels. Pevler coal
averaged higher ash combustible fractions than the other two coals. Spurlock
coal had the lowest combustible fractions in the bottom ash, but the highest
combustible fractions in the mechanical collector outlet flyash. This
relationship will be examined in greater detail in section 5.4, Coal Properf
5.3.6 Boiler Efficiency vs Grate Heat Release
Boiler efficiency was determined using the ASME heat loss method fo
all tests which included a particulate mass loading determination. The test
data, plotted in Figure 5-18, shows a general increase in efficiency as grat
heat release increases. The reason for this increase in efficiency is
illustrated in Table 5-10. It is seen that dry gas loss is a major determin'
factor.
TABLE 5-10
BOILER EFFICIENCY VS LOAD
Average Heat Losses Boiler
100%
80%
17%
Load
Load
Load
Dry
13
13
23
Gas
.1
.9
.8
Combustibles
4
4
1
.3
.8
.9
Radiation
0.
0.
3.
5
7
1
Other
6
6
5
.3
.1
.7
Efficiency
75.8
74.
65.
5
5
The measured heat losses are compared with the manufacturers pre-
dicted heat losses at 100% and 80% of design capacity in Table 5-11. The
largest discrepancy is in the dry gas heat loss category where predicted heat-
loss is several percent lower than measured heat loss.
The primary reason for this discrepancy is that design excess air
was not met on this unit. The manufacturers predicted performance is based
on 31% excess air whereas the measured excess air ranged from 43 to 69% exc
air. The predicted vs measured performance data are shown in Table 5-12
68
-------
a
c '
a
o
en
a
a
a
C '
CJ
cc o
LU O
Q_
O
[-
CJ
o
CD
DC
LU
O
CD
O
LO
-
ii
w
o
150.0 300.0 450.0 600.0 750.0
GRRTE HEflT RELERSE 1000 BTU/HR-SQ FT
O ; WHITE RSH -f : SPURLOCK
FIG. 5-18
BOILER EFFICIENCY
TEST SITE G
A : PEVLER
VS. GRflTE HERT RELERSE
69
-------
TABLE 5-11
PREDICTED VS MEASURED HEAT LOSSES
100% Design Capacity
80% Design Capacity
HEAT LOSSES, %
Dry Gas
H2 & H2O in Fuel
Moisture in Air*
Combustibles in Refuse
Radiation
Unmeasured
Total Heat Loss
Predicted
by Mfg.
10.74
4.93
0.27
4.95
0.57
1.50
22.96
White Ash
Test 5
13.25
5.28
0.00
5.33
0.52
1.50
25.88
Spur lock
Test 8
12.25
4.40
0.00
2.12
0.53
1.50
20.80
Pevler
Test 18
13.07
4.94
0.00
4.87
0.54
1.50
24.92
Predicted
by Mfg.
9.95
4.78
0.25
3.50
0.73
1.50
20.78
White Ash
Test 2
14.74
4.67
0.00
4.70
0.62
1.50
26.23
Pevler
Test 23
12.95
4.70
0.00
4.00
0.69
1.50
23.84
BOILER EFFICIENCY
77.04
74.12
79.20
75.08
79.22
73.77
76.16
*KVB used the ASME Test Form for Abbreviated Efficiency Test (PR 4.1)
which does not include moisture in air as a measured heat loss.
-------
TABLE 5-12
PREDICTED VS MEASURED PERFORMANCE DATA
100% Design Capacity
80% Design Capacity
Steam Flow, Ibs/hr
Steam Pressure, psig
Steam Temperature, °F
Feedwater Temp., °F*
Gas Temp Blr Out, °F
Excess Air, %
Boiler Efficiency, %
As Fired Coal Analysis
Moisture, %
Ash, %
Volatile, %
Fixed Carbon, %
Btu/lb
Sulfur, %
Predicted
by Mfg.
75,000
160
Sat
212
530
31
77.04
White Ash
Test 5
76,278
137
Sat
—
539
48
74.12
Spurlock
Test 8
74,690
140
Sat
—
511
43
79.20
Pevler
Test 18
72,857
138
Sat
—
526
53
75.08
Predicted
by Mfg.
60,000
160
Sat
212
490
31
79.22
White Ash
Test 2
63,750
138
Sat
—
531
69
73.77
Pevler
Test 23
56,667
139
Sat
—
515
58
76.16
6.01
6.68
34.54
51.70
12834
1.07
7.56
10.05
31.80
50.59
12036
0.85
2.91
4.27
38.62
54.20
13922
1.46
5.04
8.94
34.03
51.99
12488
0.69
6.01
6.68
34.54
51.70
12834
1.07
4.55
9.44
35.68
50.33
12639
0.72
4.56
7.15
36.83
51.46
12830
0.83
* — means data was not recorded
-------
5.4 COAL PROPERTIES
Three coals were tested in Boiler G. These coals are identified in
this report as White Ash, Spurlock and Pevler. This section describes the
chemical and physical properties of these three coals, and discusses their
observed influence on boiler emissions and efficiency.
5.4.1 Chemical Composition of the Coals
Representative coal samples were obtained from access doors
immediately above each of the unit's three coal feeders as described in -
section 4.5. Each of these coal samples was given a proximate analysis. In
addition, 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 moisture, ash and sulfur content of the three coals are compared
on a heating value basis in Table 5-13. Such a comparison is often more
meaningful than percentage by weight. This table shows that the White Ash and
Pevler coals were very similar while the Spurlock coal was lower in both
moisture and ash, and higher in sulfur content.
TABLE 5-13
COAL PROPERTIES CORRECTED TO A CONSTANT lO^TU BASIS
White Ash Spurlock Pevler
Moisture,
Ash,
Sulfur,
Ihs/lO^tu
Ibs/lO^tu
lbs/106Btu
3.5
6.3
0.61
2.2
3.2
0.95
3.6
5.7
0.59
The coal analysis for each individual sample are tabulated in
Tables 5-14, 5-15, 5-16 and 5-17.
72
-------
TABLE 5-14
FUEL ANALYSIS - WHITE ASH
TEST SITE G
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 (reducing)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
02 03 04 05 06 09 10
4.55 4.40 5.57 7.56 3.16 4.32 3.90
9.44 5.91 7.65 10.05 7.05 7.24 8.57
35.68 35.79 34.66 31.80 37.23 36.72 34.89
50.33 53.90 52.12 50.59 52.56 51.72 52.64
12639 13224 12864 12036 13254 13117 12837
0.72 0.81 0.60 0.85 0.86 0.81 0.93
4.32
73.76
4.90
0.84
0.12
0.81
7.24
8.01
2700+
2700+
2700+
2700+
41
2-1/2
15 16
4.22 4.02
9.50 7.63
34.95 34.86
51.33 53.49
12649 12965
0.68 0.74
4.22
71.62
4.66
1.12
0.07
0.68
9.50
8.13
2700+
2700+
2700+
2700+
41
2
17 COMP
3.88 4.00
7.41 10.03
35.33 36.46
53.38 49.51
13103 12635
0.82 0.77
4.00
71.40
4.60
0.98
0.10
0.77
10.03
8.12
2700+
2700+
2700+
2700+
38
1-1/2
AVG
4.56
8.05
35.19
52.21
12869
0.78
4.27
72.69
4.78
0.98
0.10
0.75
8.37
8.07
41.00
2.25
STD
DEV
1.22
1.30
1.46
1.22
365
0.10
0.07
1.51
0.17
0.20
0.04
0.09
1.60
0.08
0.00
0.35
-------
TABLE 5-15
FUEL ANALYSIS - SPURLOCK
TEST SITE G
-j
*>.
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 (reducing)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
STD
07 08 COMP AVG DEV
3.12 2.91 3.32 3.02 0.15
4.57 4.27 6.56 4.42 0.21
39.33 38.62 39.20 38.98 0.50
52.98 54.20 50.92 53.59 0.86
13797 13922 13397 13860 88
1.16 1.46 1.31 1.31 0.21
3.32
74.59
5.11
1.12
0.18
1.31
6.56
7.81
2420°F
2650°F
2680°F
2700°F+
37
2-1/2
-------
TABLE 5-16
FUEL ANALYSIS - PEVLER
TEST SITE G
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 (reducing)
Initial Deformation
Soft (H=W)
Soft (H=1/2W)
Fluid
HARDGROVE GRINDABILITY
FREE SWELLING INDEX
18 19 20 22 23 24
5.04 4.53 4.81 4.69 4.56 3.93
8.94 6.52 6.95 7.17 7.15 7.19
34.03 36.91 36.47 37.65 36.83 35.87
51.99 52.04 51.77 50.49 51.46 53.01
12488 12989 12860 12881 12830 12943
0.69 0.85 0.69 0.78 0.83 0.69
4.81
72.43
4.90
1.04
0.05
0.69
6.95
9.13
2700+°F
2700+°F
2700+°F
2700+°F
35
2-1/2
COMP AVG
4.45 4.59
7.24 7.32
37.07 36.29
51.24 51.79
12912 12832
0.65 0.76
4.45
72.91
4.86
0.96
0.05
0.65
7.24
8.88
2700+°F
2700+°F
2700+°F
2700+°F
37
1-1/2
STD
DEV
0.37
0.83
1.25
0.82
178
0.07
-------
TABLE 5-17
MINERAL ANALYSIS OF COAL ASH
TEST SITE G
Coal
Test No.
Silica, Si02
Alumina, A12O3
Titania, Ti02
Ferric Oxide, Fe2O3
Lime, CaO
Magnesia, MgO
Potassium Oxide, K2O
Sodium Oxide, Na2O
Sulfur Trioxide, 803
Phos. Pentoxide, f2°5
Strontium Oxide, SrO
Barium Oxide, BaO
Manganese Oxide, Mn^O^
Undetermined
Alkalies as Na2O (dry basis)
Silica Value
Base: Acid Ratio
T250 Temperature
Fouling Index
Slagging Index
% Pyritic Sulfur
% Sulfate Sulfur
% Organic Sulfur
White Ash
9
51.40
32.80
1.34
6.99
2.11
1.02
2.23
0.52
0.99
0.18
0.05
0.24
0.01
0.07
0.15
83.55
0.15
2820°F
0.08
0.13
0.12
0.03
0.66
15
52.83
31.52
1.58
6.84
1.19
1.09
2.47
0.48
0.80
0.14
0.08
0.23
0.02
0.73
0.21
85.28
0.14
2845°F
0.07
0.10
0.05
0.04
0.59
Comp
54.45
29.56
1.29
7.15
1.54
0.98
2.69
0.44
0.57
0.18
0.00
0.24
0.03
0.88
0.24
84.92
0.15
2825°F
0.03
0.12
0.09
0.05
0.63
Spur lock
Comp
43.26
30.37
1.21
13.50
3.43
1.32
2.05
0.61
3.61
0.19
0.10
0.26
0.02
0.07
0.13
70.33
0.28
2575°F
0.17
0.38
0.47
0.04
0.80
Pevler
20
49.62
37.75
1.88
4.52
1.32
0.84
1.53
0.31
0.56
0.15
0.07
0.12
0.01
1.32
0.10
88.13
0.10
2900°F+
0.03
0.07
0.10
0.00
0.59
Comp
52.38
36.61
1.96
3.75
1.19
0.77
1.61
0.26
0.65
0.16
0.06
0.13
0.00
0.47
0.10
90.17
0.08
2900°F+
0.02
0.05
0.08
0.00
0.57
-------
5.4.2 Coal Size Consistency
Coal size consistency was not varied for test purposes at Site G
but it was measured. 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 5-18. Spurlock coal, which had the lowest
ash content of the three coals tested, also had the lowest percentage of
fines.
The standard deviation of the coal size consistency measurements
are compared with the ABMA recommended limits for spreader stokers in Figures
5-19, 5-20 and 5-21. The size consistency of all three coals is within the
ABMA recommended limits at sizes below 1/2 inch. The fact that the measured
size distribution curves extend outside the ABMA recommended limits above
about 1/2 inch indicates only that the top size on these coals was close to
one inch whereas the ABMA limits are based on a coal having a top size of
about 1-1/4 inch. This is not considered an undesirable property.
5.4.3 Effect of Coal Properties on Emissions and Efficiency
The influence that changing coals — from White Ash to Spurlock to
Pevler — had on boiler emissions and efficiency is discussed below. Fre-
quent 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. In general, all three coals
were tested under similar excess oxygen conditions. There was no data indi-
cating that one coal could be fired at consistently lower excess oxygen con-
ditions than any other coal. Figure 5-3 shows the oxygen levels under which
the various tests were run for each coal.
Particulate Mass Loading. The effect of coal properties on this
emission is illustrated in Figure 5-4 and Table 5-19. At full load, the low
ash low fines Spurlock coal produced the lowest boiler outlet particulate
loading. The high ash high fines White Ash coal produced the highest full load
boiler outlet particulate loading. At 80% load and base load conditions there
77
-------
TABLE 5-18
AS FIRED COAL SIZE CONSISTENCY
TEST SITE G
nc
<
H
H
s
Test
No.
02
03
04
05
06
09
10
15
16
17
Composite
Average
PERCENT
1"
97.5
99.3
96.9
99.4
99.2
99.0
98.9
98.5
98.3
95.6
98.2
98.3
PASSING
1/2"
66.9
64.3
71.0
78.3
82.4
65.9
70.5
79.5
80.6
75.0
77.5
73.4
STATED
1/4"
39.5
30.7
36.3
43.0
49.8
32.2
39.3
46.6
47.8
43.0
46.6
40.8
SCREEN SIZE
#8
20.3
13.7
14.8
17.2
26.6
15.0
21.8
24.7
22.8
23.0
25.3
20.0
• .•1 i m^m^^m
#16
12.7
8.9
5.8
7.5
16.1
8.1
15.3
15.2
13.0
15.0
16.7
11.8
«
o
D
O)
07
08
Composite
Average
99.6
100.0
99.8
99.8
51.0
49.0
50.4
50.0
24.2
19.1
22.3
21.7
14.8
11.3
13.2
13.1
10.6
8.3
9.5
9.5
PEVLER
18
19
20
22
23
24
Composite
Average
98.6
95.7
96.5
94.2
98.6
95.6
94.6
96.5
86.3
67.8
64.4
68.9
79.1
69.1
68.3
72.6
51.9
33.6
32.1
31.9
32.3
31.5
32.1
35.6
24.4
15.3
14.7
13.2
12.6
14.2
14.3
15.7
14.3
9.9
9.6
8.0
8.0
9.7
9.1
9.9
78
-------
95
80
50
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Spreader Stokers
Standard Deviation Limits of White
Ash Coal Size Consistency
FIGURE 5-19,
Size Consistency of "As Fired" White Ash Coal vs
ABMA Recommended Limits of
Spreader Stokers •- Test Site
79
-------
95
80
i<
g 20
B
LO
-
50
16 8 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Spreader Stokers
Standard Deviation Limits of
Spurlock Coal Size Consistency
FIGURE 5-20.
Size Consistency of "As Fired" Spurlock Coal
vs ABMA Recommended Limits of Coal Sizing
for Spreader Stokers - Test Site G
-------
95
80
£j 50
| -
S 20
H
w
10
:
16 1/4 1/2
SIEVE SIZE DESIGNATION
ABMA Recommended Limits of Coal
Sizing for Spreader Stokers
Standard Deviation Limits of Pevler
Coal Size Consistency
FIGURE 5-21. Size Consistency of "As Fired" Pevler Coal
vs ABMA Recommended Limits of Coal Sizing
for Spreader Stokers -- Test Site G
81
-------
TABLE 5-19
EFFECT OF COAL CHANGE ON PARTICULATE LOADING
TEST DESCRIPTION
Coal
White Ash
Spurlock
Pevler
White Ash
Pevler
White Ash
Spurlock
Pevler
Test No. % Load
5
8
18
2
23
16
7
19
102
100
97
85
76
16
17
17
7.0
6.6
7.5
8.9
8.0
15.2
14.6
15.1
COAL PROPERTIES
"OFA % Ash % Fines
22
22
21
23
19
7
15
5
10.
4.
8.9
9.4
7.2
7.6
4.6
6.5
43
19
52
40
32
48
24
34
BOILER OUT
PARTICULATE
lbs/!Q6Btu
6.8
2.9
4.8
4.3
4.6
2.3
2.1
2.1
82
-------
were no differences between the White Ash and Pevler coal particulate loadings.
Only under swing load conditions did the White Ash coal produce significantly
greater particulate loadings. At 17% load all three coals gave similar
particulate loadings. Therefore, it is concluded that the coal properties
of ash and size consistency did influence particulate loadings at full load,
but not at reduced loads.
Ash Carryover. The percent of coal ash carried over as flyash was
greatest for the low fines Spurlock coal (50%). The higher fines White Ash and
Pevler coals had average ash carryovers of 42 and 34%, respectively. The
basis for this determination was given previously in Table 5-8.
Nitric Oxide. The nitric oxide concentration of the single full
load Spurlock coal test (Test 8) was 20% lower than that of the other two
coals at similar conditions. If this reduction is real (it is a risk to
base conclusions on a single data point) it cannot be attributed to fuel
nitrogen. Spurlock coal had a slightly higher fuel nitrogen content than
fa
the other two coals. Expressed in terms of lbs/10 Btu as NO , the coal's
b
nitrogen contents were White Ash - 1.63, Spurlock - 1.73, and Pevler - 1.67
lbs/106Btu.
The measured difference in full load Spurlock coal nitric oxide
concentration did not re-occur at low load. The White Ash and Pevler tests
produced similar nitric oxide concentrations. It is, therefore, concluded
that nitric oxide concentrations were similar for all three coals tested
based on available data.
Sulfur Dioxide. Sulfur balance measurments were made during three
tests, two on White Ash coal and one on Pevler coal. The sulfur balance data
are presented in Table 5-20.
83
-------
TABLE 5-20
SULFUR BALANCE ON BOILER G
White Ash (Test 9)
White Ash (Test 15)
Pevler (Test 20)
Sulfur in
Fuel
lbs/106Btu
as SO2
1.235
1.075
1.073
Sulfur in
Flue Gas
lbs/106Btu
as SO?
1.208
1.056
1.049
Sulfur in
Bottom Ash
lbs/106Btu
as SOp
0.004
0.009
0.006
Sulfur in
Flyash
lbs/106Btu
as SO 7
0.065
0.055
0.032
The sulfur balance was good. Sulfur output was between one and 4%
greater than sulfur input which is within expected measurement accuracy for
this type of test. Sulfur retention in the ash was 5.6% and 6.0% for the
White Ash coal tests, and 3.5% for the Pevler coal tests. Percent conversion
of fuel sulfur to SO2 and SO^ in the flue gas can be obtained in two ways.
The indirect method, i.e., comparing the first two columns in Table 5-20,
yields conversion efficiencies of 97.8, 98.2 and 97.8%, respectively for
Tests 9, 15 and 20. Perhaps a more accurate r.ethod is to subtract the sulfur
retained in the ash from the sulfur input. This direct method yields conversion
efficiencies of 94.4, 94.0 and 96.5%, respectively for the same tests.
Combustibles in the Ash. Percent combustibles in the bottom ash and
in the flyash showed some correlation to coal. These correlations are best
illustrated in Figure 5-14, 5-15, 5-16 and 5-17 of section 5.3. The average
combustible data for all tests above 50% load are given in Table 5-21.
The low ash, low fines and low moisture Spur lock coal had the lowest
combustible fraction in the bottom ash (Figure 5-14) but the highest com-
bustible fraction in the dust collector outlet flyash (Figure 5-16). Pevler
coal on the other hand, had the highest bottom ash fraction (Figure 5-14) and
dust collector hopper fraction (Figure 5-17). The effect of coal change in
combustibles was not great and no mechanism for the observed correlations is
proposed.
84
-------
TABLE 5-21
AVERAGE PERCENT COMBUSTIBLE IN ASH
AT LOADS ABOVE 50%
White Ash
Spurlock
Pevler
Bottom Ash
9
6
14
Boiler Out D.C. Out
Flyash Flyash
53 27
35
56 29
D.C. Hopper
Flyash
51
57
58
Boiler Efficiency. Boiler efficiency was highest while burning
Spurlock coal because of a lower combustible heat loss. This is probably
related to coal properties. Moisture related heat losses on the other hand
were similar for all three coals. Data are presented in Figure 5-18 of
section 5.3 and in Table 5-22.
TABLE 5-22
BOILER EFFICIENCY VS COAL
BOILER HEAT LOSSES, %
White Ash Coal
(Test 5)
Spurlock Coal
(Test 8)
Pevler Coal
(Test 18)
Moisture Comb us- BOILER
Dry Gas Related tible Other EFFICIENCY, %
13.3 5.3
12.3 4.4
13.1 4.9
5.3
2.1
4.9
2.0
2.0
2.0
74.1
79.2
75.1
85
-------
5.5 PARTICLE SIZE DISTRIBUTION OF FLYASH
Ten particle size distribution determinations were made at the
boiler outlet on Boiler G. These determinations were made using a Bahco
classifier, a Brink cascade impactor, and a SASS cyclone train. Test
conditions for the ten particle size distribution tests are described in
Table 5-23.
The test results are presented in Table 5-24, and in Figures 5-22,
5-23 and 5-24. The test results are grouped by sample methodology (i.e.,
Brink, Bahco or SASS) because each methodology may influence the data. A
discussion of each method, its advantages and drawbacks, is presented in
Section 4. The basic differences are outlined below.
The Bahco classifier sample was collected with a cyclone. As a
result, a fraction of the sample (6 to 12%) 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 5-24, 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.
Despite the differences in methodologies, there is a degree of
validity to the data trends. The measured differences in particle size
distribution are often reflected in the multiclone collection efficiencies
as shown in Table 5-25. In many cases, the flyash with the lowest percentage
of particles below 10 or 3 micrometers was the flyash most efficiently
collected in the mechanical dust collector.
The data indicates that flyash from White Ash coal was sized smaller
than flyash from Pevler coal and was thus captured more efficiently in
the mechanical dust collector.
86
-------
TABLE 5-23
DESCRIPTION OF PARTICLE SIZE DISTRIBUTION
TESTS AT THE BOILER OUTLET
TEST SITE G
Coal
White Ash 102
Spurlock 100
Pevler 97
White Ash 98
White Ash 77
©2 Test
%_ Description
White Ash
White Ash
White Ash
White Ash
Pevler
102
98
72
87
78
7.0 Base Loaded
6.6 Base Loaded
7.5 Base Loaded
7.4 w/o Reinjection
10.4 Swing Loaded
7.0 Base Loaded
7.4 w/o Reinjection
10.2 Swing Loaded
8.7 Swing Loaded
9.2 Swing Loaded
Particle Size Distribution
Methodology Used
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Bahco - Sieve
Brink Impactor
Brink Impactor
SASS Gravimetrics
SASS Gravimetrics
SASS Gravimetrics
87
-------
TABLE 5-24
RESULTS OF PARTICLE SIZE DISTRIBUTION TESTS
AT THE BOILER OUTLET
TEST SITE G
CD
oo
Test
No.
5
8
18
9
15
20
5
17
5
17
5
4
Test Description
Full Load, White Ash Coal-
Full Load, Spur lock Coal -
Full Load, Pevler Coal
Swing Load, White Ash Coal-
Swing Load, Spur lock Coal -
Swing Load, Pevler Coal -
With Reinjection
Without Reinjection
With Reinjection
Without Reinjection
Full Load
77% Load
Size
Distribution
% Below
3ym
Banco
Bah co
Bahco
SASS
SASS
SASS
Bahco
Bahco
Brink
Brink
Bahco
Bahco
1
.2
2
10
8
23
1
2
7
3
1
2
.1
.5
.2
.4
.1
.0
.1
.5
.2
.6
.1
.6
% Below
lOym
4
7
8
21
27
50
4
10
4
9
.5
.5
.8
.1
.5
.2
.5
.0
--
.5
.2
Size Concentration
lb/10bBtu
Below 3ym
0
0
0
0
0
0
0
0
0
.075
.073
.105
--
.075
.146
.489
.211
.075
.193
lb/106Btu
Below loym
0.305
0.220
0.421
—
0.305
0.586
--
0.305
0.682
Sample
Collection
Efficiency, %
93
87
91
100
100
100
93
91
100
100
93
89
.4
.8
.2
.4
.9
.4
.1
-------
99.9
H
-
95 ~
80
50
-
oo w 20
5
0.1
teAHCO CLASSIFIER :
::'• : :
SIEVE ANALYSIS :
10 30 100 300
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
1000
3000
FIGURE 5-22. Particle Size Distribution of the Boiler Outlet Flyash by
Bahco Classifier and Sieve Analysis -• Test Site G
-------
-
20
,:,
i1!
w
0.1
100% Capacity Base Load Tests
With Flyash Reinjection
Without Flyash Reinjection
0.3 1 3
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
Figure 5-23.
Particle Size Distribution at the Boiler Outlet
by Brink Cascade Impactor - Test Site G.
-------
lit!:.. : ::...:
80% Capacity Swing Load Tests -
LO
EQUIVALENT PARTICLE DIAMETER, MICROMETERS
Figure 5-24.
Particle Size Distribution at the Boiler Outlet
by SASS Gravimetrics - Test Site G.
91
-------
TABLE 5-25
PARTICLE SIZE DISTRIBUTION
VS DUST COLLECTOR EFFICIENCY
Test Test
No. Methodology
5 Bahco
8 Bahco
18 Bahco
9 SASS
15 SASS
20 SASS
5 Bahco
17 Bahco
% Flyash
Test Description Below IQyim
White Ash - Full Load 4.5
Spurlock Coal - Full Load 7.5
Pevler Coal - Full Load 8.8
White Ash Coal - Swing Load 21.1
White Ash Coal - Swing Load 27.5
Pevler Coal - Swing Load 50.2
White Ash Coal - w/Reinjection 4.5
White Ash Coal w/o Reinjection 10.0
Dust Collector
Efficiency, %
96.0
94.3
93.3
97.0 -(Test 4)*
92.7 (Test 10)
92.9 (Test 22)
96.0
93.8
*SASS tests 9, 15 and 20 did not include determination of dust
collector efficiency, but a glance at Figure 5-25 in the
following section shows that White Ash coal averaged higher col-
lection efficiencies than Pevler B coal at this load range.
Collection efficiencies shown are for the most similar particu-
late tests.
92
-------
5.6 EFFICIENCY OF MULTICLONE DUST COLLECTOR
The collection efficiency of the multiclone dust collector was
determined in fifteen 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. The data are presented in Table
5-26 and plotted as a function of grate heat release in Figure 5-25.
At loads above 50% of design capacity, the dust collection efficiency
ranged from 92.7% to 97.0% and averaged 94.4%. At the low load of 17% of de-
sign steam capacity, the mechanical dust collection efficiency dropped off
drastically averaging 63.4%. This is due to the reduced pressure drop across
the dust collector at low loads.
5.7 SOURCE ASSESSMENT SAMPLING SYSTEM (SASS)
Three SASS tests were run at Test Site G and two of these were
selected for further processing. Test 15 on White Ash coal was a repeat of Test
9 which was suspect due to a procedural error. On Pevler coal, Test 20
was processed.
Process of the SASS sample catches involves combined gas chromato-
graphy/mass spectroscopy for total polynuclear content and seven specific
polynuclear aromatic hydrocarbons (PAH). These are listed in Table 5-27.
All SASS test results will be reported under separate cover at the conclusion
of this test program.
93
-------
TABLE 5-26
EFFICIENCY OF DUST COLLECTOR
TEST SITE G
Particulate Loading
lb/106Btu
Test
No.
02
03
04
05
06
07
08
10
16
17
18
19
22
23
24
Coal
Type
White Ash
White Ash
White Ash
White Ash
White Ash
Spur lock
Spur lock
White Ash
White Ash
White Ash
Pevler
Pevler
Pevler
Pevler
Pevler
Load
%
85.0
79.6
76.7
101.7
57.4
17.3
99.6
86.0
15.8
97.7
97.1
16.6
82.4
75.6
78.3
°2
%
8.9
8.7
10.4
7.0
10.5
14.6
6.6
9.7
15.2
7.4
7.5
15.1
9.1
8.0
7.3
Collector
Inlet
4.271
4.332
7.408
6.786
4.171
2.139
2.932
6.592
2.265
5.858
4.783
2.057
4.720
4.567
4.003
Collector
Outlet
0.222
0.220
0.221
0.274
0.129
0.953
0.166
0.484
0.933
0.364
0.320
0.495
0.334
0.320
0.260
Collector
Efficiency
%
94.8
94.9
97.0
96.0
96.9
55.4
94.3
92.7
58.8
93.8
93.3
75.9
92.9
93.0
93.5
94
-------
o
o
•
o
CO
o
o
LU
(_>
DC O
UJ O
Q- •
O
LU
LU
Z
O
g
'—'
0
1 1 1 1 1
150.0 300.0 450.0 600.0 750.0
GRRTE HERT RELERSE 1000 BTU/HR-SQ FT
; WHITE flSH
: SPURLOCK
: PEVLER
FIG. 5-25
MULTICLONE EFF.
TEST SITE G
VS. GRRTE HERT RELERSE
95
-------
TABLE 5-27
POLYNUCLEAR AROMATIC HYDROCARBONS
ANALYZED IN THE SITE G 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
C24H14
C24H14
C20H13N
5.8 DATA TABLES
Tables 5-28 through 5-31 sunmarize the test data obtained at Test
Site G. These tables, in conjunction with Table 2-2 in the Executive
Summary, are included for reference purposes.
96
-------
TABLE 5-28
PARTICULATE EMISSIONS
TEST SITE G
f
p
§
05
3
H
o
03
Test
No.
02
03
04
05
06
07
08
10
16
17
18
19
22
23
24
% Design O
Coal Capacity %
White Ash 85
White Ash
White Ash
White Ash
White Ash
Spur lock
Spur lock
White Ash
White Ash
White Ash
Pevler
Pevler
Pevler
Pevler
Pevler
80
77
102
57
17
100
86
16
98
97
17
82
76
78
8.9
8.7
10.4
7.0
10.5
14.6
6.6
9.7
15.2
7.4
7.5
15.1
9.1
8.0
7.3
EMISSIONS
lb/106Btu gr/SCF
4.271 1.772
4.332
7.408
6.786
4.171
2.139
2.932
6.592
2.265
5.858
4.783
2.057
4.720
4.567
4.003
1.911
2.740
3.102
1.572
0.482
1.506
2.590
0.460
2.550
2.138
0.416
1.917
2.018
1.882
Ib/hr
763
782
1,179
1,464
558
96
568
1,120
96
1,326
980
81
848
811
717
Velocity
ft/sec
39.69
37.32
38.04
42.27
30.36
16.16
35.14
38.79
16.72
50.45
42.64
15.83
41.63
37.70
35.86
EH
p
8
e:
o
H
N
3
O
U
J
o
H
X
M
02
03
04
05
06
07
08
10
16
17
18
19
22
23
24
White Ash
White Ash
White Ash
White Ash
White Ash
Spur lock
Spur lock
White Ash
White Ash
White Ash
Pevler
Pevler
Pevler
Pevler
Pevler
85
80
77
102
57
17
100
86
16
98
97
17
82
76
78
9.9
9.2
10.0
7.6
11.0
14.8
6.9
9.1
15.2
7.4
7.5
15.1
9.1
8.0
7.3
0.222
0.220
0.221
0.274
0.129
0.953
0.166
0.484
0.933
0.364
0.320
0.495
0.334
0.320
0.260
0.085
0.093
0.085
0.120
0.046
0.208
0.084
0.200
0.190
0.158
0.142
0.100
0.136
0.141
0.122
18
19
17
25
8
26
18
42
20
34
32
10
29
27
24
63.21
62.64
62.88
65.63
50.28
34.78
68.19
65.87
28.70
68.65
70.96
27.57
67.62
60.42
62.61
97
-------
TABLE 5-29
HEAT LOSSES AND EFFICIENCIES
TEST SITE G
3
8
K
a
s
H
H
§B
E^
to
g
02
03
04
05
06
09
10
15
16
17
to
Q
•J
rij
w
1
14.74
13.35
19.27
13.25
13.13
14.29
13.48
12.91
22.73
13.96
H
E
2
H
§
p
to
M
0.45
0.41
0.54
0.80
0.29
0.41
0.38
0.42
0.36
0.37
1
-------
TABLE 5-30
PERCENT COMBUSTIBLES IN REFUSE
TEST SITE G
SB
3
W
^
g
Test
No.
02
03
04
05
06
10
15
16
17
09
Average
Boiler
Outlet
58.1
52.2
—
49.7
47.7
57.0
—
47.6
—
—
52.05
Mechanical
Collector
Hopper
53.91
53.91
56.74
49.85
49.85
42.73
40.65
57.30
57.30
55.71
51.80
Mechanical
Collector
Outlet
^ ^
29.1
28.9
—
—
22.9
—
16.8
28.7
—
25.3
Bottom
Ash
12.53
7.26
11.23
6.93
7.11
9.77
14.88
8.18
7.34
7.87
9.51
SPURLOCK
07
08
Average
47.4
47.4
50.05
56.65
53.35
54.2
34.6
44.4
4.22
6.02
5.12
tt
>
8
18
19
20
22
23
24
Average
_ —
50.1
—
54.7
50.6
62.9
54.6
51.15
62.51
57.09
67.03
57.57
56.15
58.58
29.5
53.0
—
28.6
28.8
30.2
34.0
13.93
8.79
12.32
19.09
13.12
11.48
13.12
99
-------
TABLE 5-31
STEAM FLOW AND HEAT RELEASE RATES
TEST SITE G
Test
No.
01
02
03
04
05
06
07
08
09
10
11
12
15
16
17
18
19
20
22
23
24
25
26
% Design
Capacity
92.2
85.5
79.6
76.7
101.7
57.4
17.3
99.6
72.3
86.0
77.9
98.3
87.4
15.8
97.7
97.1
16.6
77.7
82.4
75.5
78.3
99.5
77. 8
Steam Flow
103lb/hr
69.2
63.8
59.7
57.6
76.3
43.1
13.0
74.7
54.2
64.5
58.4
73.7
65.6
11.9
73.3
72.9
12.4
58.3
61.8
56.7
58.7
74.6
58.4
Heat Input*
106Btu/nr
103.2
95.2
89.2
85.9
113.9
64.3
19.4
111.5
80.9
96.3
87.2
110.0
97.9
17.7
109.4
108.8
18.6
87.0
92.2
84.6
87.6
111.4
87.2
Heat Output
106Btu/hr
82.6
76.1
71.3
68.8
91.1
51.4
15.5
89.2
64.8
77.0
69.8
88.0
78.3
14.2
87.5
87.0
14.9
69.6
73.8
67.7
70.1
89.1
69.8
Front Foot.
Heat Release
IQ^tu/ft/hr
1058.9
976.3
914.4
881.5
1168.0
659.5
199.2
1143.9
830.2
987.7
894.5
1128.6
1004.0
181.5
1121.8
1115.6
190.7
892.5
946.0
867.7
898.7
1142.1
894.3
Grate
Heat Release
lO^tu/ftVhr
753.6
694.7
650.7
627.4
831.3
469.4
141.8
814.1
590.8
702.9
636.6
803.2
714.5
129.2
798.3
793.9
135.7
635.2
673.3
617.5
639.4
812.8
636.4
Furnace
Heat Release
102Btu/ft3/hr
250.6
231.0
216.4
208.6
276.4
156.1
47.1
270.7
196.5
233.7
212.0
267.1
237.6
43.0
265.5
264.0
45.1
211.2
223.9
205.3
212.7
271.6
212.7
o
o
* Because there was no coal scale on Boiler G, heat input was computed as
heat output divided by 0.8.
-------
APPENDICES
Page
APPENDIX A Discussion of Low Ash Coal Problem iQ2
APPENDIX B English and Metric Units to SI Units 103
APPENDIX C SI Units to English and Metric Units 104
APPENDIX D SI Prefixes 105
APPENDIX E Emissions Units Conversion Factors 106
APPENDIX F Unit Conversion from ppm to lb/106Btu 107
101
-------
APPENDIX A
DISCUSSION OF LOW ASH COAL PROBLEM
The following discussion is taken from internal correspondence at
Test Site G. In this discussion, coal A and B refer to the coals described
in this report as White Ash and Spurlock respectively. Coal C refers to a coal
which was never fired and which was later replaced by Pevler Coal.
As discussed in our telephone conversation on February 26,
the low ash content of test coal B (I" x 3/8") is causing
problems in maintaining the proper depth of ashes (4" - 6")
on the grate of the #5 boiler. We are able to maintain only
1-1/2" of ash depth with the grate moving as slow as possible.
The low ash depth could cause the grate to overheat if a high
steam load is maintained over an extended period of time.
I realize we are in the process of testing different coals
with the American Boiler Manufacturers Association, but with
this low ash content, the test schedule will have to be
altered.
We have tested our normally stocked coal (1-1/4" x 1/4")
according to the suggested first week test schedule of
KVB with the exception of a 60 - 75,000 Lb/Hr swing load
with normal 02 and OFA. That test could not be run due
to coal handling problems at the time.
The test involving Coal B was started on Sunday, Febru-
ary 25 and the 15,000 and 75,000 Lb/Hr steady load tests
were completed. Stack appearance at 15,000 Lb/Hr does
not appear to be acceptable. Boiler controls were varied
at the end of the minimum load test to reduce the smoking
condition/ but no change was noticed. With these two tests
of Coal B completed, we plan no further testing of this low
ash coal. We plan to mix the existing car of low ash coal
with the coal already in the silo and the remaining cars
will be unloaded at the Anchor storage stockpile. The
rest of the test period for coal B will be used for test-
ing coal A.
We will have to discuss the remaining test schedule with
the KVB testing group. Two cars of coal c (1/2" x 1/8"
are in shipment to this facility and scheduled for testing
during the week of March 10. If arrangements can be made,
we would like to test at 15,000 Lb/Hr and then discontinue
testing. Coal C, which is also a low ash coal, with 30 -
40% fines will also cause problems in maintaining a proper
depth of ashes, but should not damage the grate at the
low load.
I plan to discuss these changes in testing with Jim Burlingame
of KVB and will let you know of any further development.
102
-------
APPENDIX B
CONVERSION FACTORS
ENGLISH AND METRIC UNITS TO SI UNITS
To Convert From
in
ft
ft
To
cm
m
m-
Multiply By
2.540
6.452
0.3048
0.09290
0.02832
Ib
Ib/hr
lb/106BTU
g/Mcal
BTU
BTU/lb
BTU/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
°2
°2
02
02
°2
(S02)
(SO 3)
(NO)*
(N02)
(CO)
(CH4)
Kg
Mg/s
ng/J
ng/J
J
JAg
w
w
w
W/m
J/hr/m
J/hr/m2
W/m3
J/hr/m3
Pa
Pa
Celsius
Celsius
Kelvin
Kelvin
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
(lb/106Btu)
(Ib/lO^Btu)
(Ib/lO^tu)
(lb/106Btu)
(Ib/lO^tu)
(lb/106Btu)
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
(1. 98x10" J)
(2.47xlO~3)
(9.28xlO~4)
(1.42xlO~3)
(8.65xlO~4)
0.213
(4.95xlO~4)
*Federal environmental regulations express NOx in terms of NO2;
thus NO units should be converted using the N02 conversion factor.
103
-------
APPENDIX C
CONVERSION FACTORS
SI UNITS TO ENGLISH AND METRIC UNITS
To Convert From
cm
cm"
m
Kg
Mg/s
ng/J
ng/J
J
JAg
J/hr/m
J/hr/m2
J/hr/m3
W
W
W/m
W/m2
W/m3
Pa
Pa
Kelvin
Celsius
Fahrenheit
Kelvin
FOR TYPICAL COAL FUEL
ng/J
ng/J
ng/J
ng/J
ng/J
ng/J
To
Multiply By
in
in2
ft
ft2
ft3
Ib
Ib/hr
Ib/lO^TU
g/Mcal
BTU
BTU/lb
BTU/ft/hr
BTU/ft2/hr
BTU/ft3/hr
BTU/hr
J/hr
BTU/ft/hr
BTU/ft2/hr
BTU/ft3/hr
psia
"H20
Fahrenheit
Fahrenheit
Rankine
Rankine
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
ppm @ 3% 02 (SO2)
ppro @ 3% O2 (S03)
ppm @ 3% O2 (NO)
ppm @ 3% O2 (N02)
ppm @ 3% 02 (CO)
ppm @ 3% 02 (CH4)
1.18
0.941
2.51
1.64
2.69
4.69
104
-------
APPENDIX D
SI PREFIXES
Multiplication
Factor Prefix SI Symbol
1018 exa E-
1015 peta P
1012 tera T
10^ giga G
10 mega M
103 kilo k
10 hecto* h
101 deka* da
10 deci* d
10 centi* c
10" ^ milli m
10" micro p
10~9 nano n
10~12 pico p
10~15 femto f
10~18 atto a
*Not recommended but occasionally used
105
-------
EMISSION UNITS CONVERSION FACTORS
FOR TYPICAL COAL FUEL (HV = 13,320 BTU/LB)
Multiply
To "~\^ By
Obtain
% Weight
In Fuel
N
% Weight in Fuel
S N
lbs/!06Btu
S02 NO2
0.666
0.405
grams/106Cal
SO2 NO2
0.370
0.225
PPM
(Dry @ 3% 02)
SOx NOx
13.2x10
-4
5.76xlO~4
Grains/SCF.
(Dry @ 12% C02)
SO2 N02
1.48
.903
lbs/106Btu
SO-
1.50
NO-
(.556)
19.8x10
,-4
(2.23)
2.47
(.556)
14.2xlO~4
(2.23)
SO-
2.70
grams/106Cal
(1.8)
NO-
4.44
35.6x10
-4
(4.01)
(1.8)
25.6x10"
(4.01)
SOx
PPM
(Dry @ 3% 02)
NOx
758
505
281
1736
704
1127
391
1566
Grains/SCF
(Dry@12%
SO-
.676
(.448)
(.249)
8.87x10
-4
NO-
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.
-------
APPENDIX F
UNITS CONVERSION FROM PARTS PER MILLION (PPM) TO
POUNDS PER MILLION BTU INPUT (LB/IO^TU)
lb/10^Btu = (ppm) (fuel factor, y-g——) (O2 correction, n.d. ) (density of
emission, } (1CT6)
SCF* r
Fuel factor, ,b = 106[1.53C + 3.61H2 + -14N2 + -57S - .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 •=• (20.9 - %02)
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 = S02 - 0.1696 Ib/SCF*
NO - 0.0778 Ib/SCF
CO - 0.0724 Ib/SCF
CH4 - 0.0415 Ib/SCF
to convert Ibs/lO^tu to ng/J multiply by 430
* Standard conditions are 70°F, 29.92 "Hg barometric pressure
107
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
. REPORT NO.
EPA-600/7-80-0823.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Field Tests of Industrial Stoker Coal-
fired Boilers for Emissions Control and Efficiency
Improvement--Site G
5. REPORT DATE
April 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
PERFORMING ORGANIZATION REPORT NO.
P.L.Langsjoen, J.O. Burlingame, and
J.E.Gabriels on
). PERFORMING ORGANIZATION NAME AND ADDRESS
KVB, Inc.
6176 Olson Memorial Highway
Minneapolis, Minnesota 55422
10. PROGRAM ELEMENT NO.
EHE624
11. CONTRACT/GRANT NO. ~
IAG-D7-E681 (EPA) and
EH-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
Final; 2/79-3/79
NDPERIOC COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
15.SUPPLEMENTARY NOTES T£RL-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.-130a.-147a.-80-064a and -065a are Site A.B,C,D,E,and F reports.
4^^^^^^^^^^^^^^^^•'"^^^^••^""••••i™
16. ABS1
The report gives results of field measurements made on a 75,000 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 reinjec-
tion, excess air, boiler load, and fuel properties. Measurements included O2, CO2
NO, NO2, SO2, SO3, HC, controlled and uncontrolled particulate loading, particle
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 5.09 Ib/million Btu uncontrolled and 0.28 Ib/million Btu controlled at full load.
Nitric oxide emissions averaged 0.49 Ib/million Ptu (360 ppm) at full load.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution
Boilers
Combustion
Coal
Field Tests
Dust
Stokers
13"B
13A
21B
21D
14B
COSATI Field/Group
Improvement
Efficiency
Flue Gases
Fly Ash
Particle Size
Nitrogen Oxides
Sulfur Oxides
Air Pollution Control
Stationary Sources
Combustion Modification
Spreader Stokers
Particulate
Overfire Air
Flyash Reinjection
3. DISTRIBUTION STATEMEN1
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
20. SECURITY CLASS (Thispage)
21. NO. OF PAGES
114
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
108
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