EPA-600/2-77-129
July 1977
Environmental Protection Technology Series
OPERATION AND MAINTENANCE
F PARTICULATE CONTROL DEVICES
ON COAL-FIRED UTILITY BOILERS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park. North Carolina 27/11
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental Protection
Agency, have been grouped into five series. These five broad categories were established to
facilitate further development and application of environmental technology. Elimination of
traditional grouping was consciously planned to foster technology transfer and a maximum
interface in related fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION TECHNOLOGY
series. This series describes research performed to develop and demonstrate instrumenta-
tion, equipment, and methodology to repair or prevent environmental degradation from point
and non-point sources of pollution. This work provides the new or improved technology
required for the control and treatment of pollution sources to meet environmental quality
standards.
EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily reflect the views and
policy of the Agency, 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 Information Service,
Springfield, Virginia 22161.
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EPA-600/2-77-129
July 1977
OPERATION AND MAINTENANCE OF
PARTICULATE CONTROL DEVICES
ON COAL-FIRED UTILITY BOILERS
by
Michael F. Szabo and Richard W. Gerstle
PEDCo. Environmental Specialists, Inc.
11499 Chester Road
Cincinnati, Ohio 45246
Contract No. 68-02-2105
Program Element No. 1 ABO 12
ROAP 21ADL-037
EPA Project Officer: Dennis C. Drehmel
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, N.C. 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, D.C. 20460
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ABSTRACT
The subject of control of fine particulate from coal-
fired utility boilers with electrostatic precipitators, wet
scrubbers, and fabric filters is addressed. Utility person-
nel who are responsible for the selection of fine particu-
late control equipment are presented with guidelines on the
significant design and cost data correlations based on
current design practice for electrostatic precipitators and
actual operating and cost data for wet scrubbers and fabric
filters. Fractional efficiency prediction models are pre-
sented for electrostatic precipitators and wet scrubbers
which allow comparison of capital and operating costs under
different coal/boiler application conditions and different
levels of fractional efficiency on particles in the size
range of 0.2 to 0.4 microns.
11
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ACKNOWLEDGEMENT
This report was prepared for the Industrial Environ-
mental Research Laboratory, U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina by PEDCo
Environmental, Inc., Cincinnati, Ohio; Cottrell Environmental
Sciences, Research-Cottrell, Inc., Bound Brook, New Jersey;
and Midwest Research Institute, Kansas City, Missouri.
The project director was Mr. Richard W. Gerstle and the
project managers were Messrs. Norman J. Kulujian and Michael
F. Szabo. PEDCo Environmental, Inc., as the primary con-
tractor, directed and coordinated the entire project effort,
as well as providing and integrating into the report addi-
tional data to that provided by the subcontractors. John
Tuttle provided the computer program of the Calvert Scrubber
model for use in the study. Graphics for the report were
prepared under the direction of Ms. Nancy Wohleber. The
report was edited by Ms. Anne Cassel and Ms. Marty Phillips.
Cottrell Environmental Sciences researched and coordi-
nated the electrostatic precipitator and wet scrubber infor-
mation. The scope of work was managed and executed by Mr.
David V. Bubenick with major contributions from Mr. David W.
iii
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Coy, presently with Research Triangle Institute, North
Carolina. Contributions from the following persons are also
gratefully acknowledged; Dr. P. D. Paranjpe, Messrs. Chin T.
Sui, Matt D. Willis, Peter J. Aa, Richard Jakoplic, George
A. Carkhuff, and D. Scott Kelly. The CES effort was directed
by Drs. Paul L. Feldman and Richard S. Atkins.
Midwest Research Institute performed the evaluation in
fabric filtration systems. The effort was conducted by Dr.
K. P. Ananth and Mr. Joe Schum.
IV
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TABLE OF CONTENTS
Page
SUMMARY xv
1.0 INTRODUCTION 1-1
1.1 Purpose of Report 1-1
1.2 Significance of Particulate Emissions 1-2
1.3 Scope of the Report 1-3
2.0 CONTROL SYSTEM PARAMETERS 2-1
2.1 Summary of Control Devices 2-1
2.2 Comparison of Alternative Control Systems 2-3
2.3 Design Considerations - Electrostatic
Precipitators 2-6
2.4 Interpretation of Graphical Correlations
for Cold- and Hot-Side Electrostatic
Precipitators 2-24
2.5 Design Considerations - Wet Scrubbers 2-49
2.6 Design Considerations for Fabric Filters 2-59
3.0 OPERATION AND MAINTENANCE OF PARTICULATE CONTROL
DEVICES ON COAL-FIRED BOILERS 3-1
3.1 Operation and Maintenance of Electrostatic
Precipitators 3-1
3.2 Operation and Maintenance of Wet Scrubbers 3-52
3.3 Operation and Maintenance of Fabric Filters 3-76
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TABLE OF CONTENTS (Cont'd)
4.0 FRACTIONAL EFFICIENCY RELATIONSHIPS
4.1 Limitations of Current Data
4.2 Summary of Inlet Particle Size Distribution
Data Used for Precipitator and Scrubber
Computer Models
4.3 Electrostatic Precipitator Computer Model
4.4 Wet Scrubber Computer Models
4.5 Fractional/Total Mass Efficiency for Fabric
Filters
5.0 CONCLUSIONS
5.1 Design Practices
5.2 Operation and Maintenance
5.3 Fractional Efficiency Relationships
5.4 Costs
APPENDIX A LIST OF U.S. POWER PLANTS WITH
ELECTROSTATIC PRECIPITATORS HAVING
EFFICIENCIES OF 95 PERCENT OR GREATER
APPENDIX B
APPENDIX C
APPENDIX D
Page
4-1
4-2
4-3
4-3
4-24
4-52
5-1
5-1
5-7
5-8
5-10
A-l
GRAPHICAL CORRELATIONS OF CAPITAL AND
ANNUALIZED OPERATING COSTS, AS A
FUNCTION OF PLANT POWER OUTPUT FOR
ELECTROSTATIC PRECIPITATORS
PRE-OPERATING CHECKLIST FOR
PRECIPITATORS
CHECKLIST FOR OBTAINING DESIGN AND
OPERATING DATA ON PARTICULATE SCRUBBERS
B-l
C-l
D-l
Vi
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LIST OF FIGURES
No. Page
2-1 Sectionalization of the Precipitator 2-16
2-2 High-Tension Splits of a Mechanical Section 2-21
2-3 SCA Versus Sulfur Content: Cold-Side ESP,
Pulverized Eastern Bituminous 2-28
2-4 SCA Versus Sulfur Content: Cold-Side ESP,
Cyclone-Fired Eastern Bituminous 2-29
2-5 SCA Versus Sulfur Content: Cold-Side ESP,
Pulverized Western Subbituminous 2-33
2-6 SCA Versus Sodium Content: Cold-Side ESP,
Pulverized Lignite 2-34
2-7 SCA Versus Sodium Content: Hot-Side ESP,
Pulverized-Coal Firing 2-38
2-8 SCA Versus Sodium Content: Hot-Side ESP,
Cyclone Firing 2-39
2-9 Performance Versus SCA of Hot-Side Precipitators 2-41
2-10 Power Density Versus Sulfur Content: Cold-Side
ESP, Pulverized Eastern Bituminous 2-43
2-11 Power Density Versus Sodium Content: Cold-Side
ESP, Pulverized Lignite 2-45
2-12 Maintenance Labor Requirements for the Nucla
Baghouse 2-83
3-1 Typical Electrostatic Precipitator with Top
Housing 3-4
3-2 Vibrator and Rapper Assembly, and Precipitator
High-Voltage Frame 3-8
vii
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LIST OF FIGURES (GontM)
No.
3-3 Typical Precipitator Insulator Compartment and
Cleaning Assembly 3-9
3-4 SCR Mainline Control 3-14
3-5 Discharge Electrode Unshrouded 3-19
3-6 Discharge Electrode Shrouded 3-19
3-7 Precipitator Collecting Electrodes 3*19
3-8 Typical Operating Curve to Meet Emission
Regulations with Partial Malfunctions of ESP 3-51
3-9 Simplified Flow Diagram of Fly Ash Scrubbers,
Four Corners Plant 3~3€
3-10 Simplified Flow Diagram of Fly Ash Scrubbers,
Dave Johnston Plant 3*57
3-11 Simplified Flow Diagram of Fly Ash Scrubber,,
Lewis and Clark Plant 3*-59
V
3-12 Simplified Flow Diagram for the Particulate
at the Clay Boswell Station 3-€7
3-13 Typical Scrubber Installation at Valmont,
Cherokee, and Arapahoe Stations, Public Service
Company of Colorado 3-71
4-1 Percent Penetration, Pulverized-Coal -Fired
Boiler (Cold-Side ESP) ? 4*9
4-2 Percent Penetration, Cyclone-Fired Boiler
(Cold-Side ESP) 4_10
4-3 Percent Penetration, Stoker-Fired Boiler
(Cold-Side ESP) 4-11
4-4 Measured Efficiency as a Function of Particle
Size for Precipitator Installation at the Gc-rgas
Plant of Alabama Power Company 4-13
4-5 Fractional Efficiencies for the Wood River
Precipitator 4-14
viii
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LIST OF FIGURES (Cont'd)
NO.
4-6 Average Fractional Efficiency for a Hot-Side
ESP Installation 4-15
4-7 Computed Versus Actual Percent Penetration for
Cold-Side ESP on a Western Subbituminous-Fired
Boiler 4-16
4-8 Predicted Performance of Venturi Scrubbers in
Removal of Fine Particulate 4-34
4-9 Predicted Fine Particulate Performance of
Flooded-Disc Scrubber at Montana-Dakota Utilities
Lewis and Clark Station 4-36
4-10 Predicted Performance of TCA Scrubbers on Fine
Particulate 4-38
4-11 Predicted Performance of High-Pressure Spray
Scrubbers in Removal of Fine Particulate 4-40
4-12 Wet Scrubber Fractional Efficiency Test Data
from Various Coal-Fired Boilers 4-48
4-13 Comparison of Predicted and Actual Test Results
for the Cherokee Scrubber 4-51
4-14 Median Fractional Efficiency for 22 Tests on
Nucla Baghouse 4-58
4-15 Penetration as a Function of Air-to-Cloth Ratio
with One Standard Deviation Limit, Nucla
Baghouse 4-59
4-16 Fractional Penetration Through Nucla Baghouse
(11-MW Load) 4-61
4-17 Fractional Penetration Through Nucla Baghouse
(6-MW Load) 4-63
4-18 Removal Efficiency as a Function of Particle
Size for Runs with Used Bags, Sunbury Baghouse 4-70
4-19 Removal Efficiency as a Function of Particle
Size for Runs with New Bags, Sunbury Baghouse 4-71
IX
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LIST OF FIGURES (Cont'd)
No. Page
4-20 Baghouse Performance at Sunbury Steam Electric
Station 4-73
4-21 Penetration Vs. Particle Diameter, Teflon Felt
Style 2663 4-75
4-22 Penetration Vs. Particle Diameter, Gore-Tex/
Nomex 4-77
4-23 Penetration Vs. Particle Diameter, Dralon-T 4^-79
4-24 Penetration Vs. Particle Diameter, Nomex Felt 4-80
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LIST OF TABLES
No. Page
2-1 Factors Bearing on Control Device Selection 2-4
2-2 Design Consideration for an ESP 2-7
2-3 Emissions from Different Boiler Types 2-10
2-4 Design Parameters and Design Categories for
Electrostatic Precipitators 2-14
2-5 Design Power Density 2-20
2-6 Percipitator Parameters Recently Specified
by TVA 2-31
2-7 ESP Design and Test Data for Power Plants
Burning North Dakota Lignites 2-36
2-8 Trends in Capital and Operating Costs of ESP's
as a Function of Coal and Boiler Types (at 99.5
Percent Overall Mass Collection Efficiency) 2-48
2-9 Condensed Summary of Operating Wet Scrubbers in
Western United States 2-52
2-10 Cherokee No. 3 Scrubber Capital Cost Breakdown
1972 Dollars 2-57
2-11 Cherokee No. 3 Scrubber Operating Costs (1972) 2-58
2-12 Comparison of Fabric Filter Cleaning Methods 2-63
2-13 Normal Cleaning Sequence for each Compartment
of the Nucla Baghouse 2-64
2-14 Fabric Filter Characteristics 2-67
2-15 Characteristics of Nomex^Teflon,®Gore-Tex,®
and Draloftfi/ 2-69
xi
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LIST OF TABLES (Cont'd)
No.
Page
2-16 Design Factors for Fabric Filtration Systems
Operating at Coal-Fired Power Plants 2-73
2-17 Boiler and Fuel Characteristics for Utility
Plants Using Fabric Filtration Systems 2-74
2-18 Summary of Capital Cost Nucla Station Eagliouses 2-75
2-19 Sunbury Steam Electric Station Bag Filter
Installation Cost Breakdown 2-77
2-20 Nucla Fabric Filter System Operating Cost
Estimate (1976) 2-81
2-21 Baghouse Maintenance Summary 2-82
2-22 Reliability of Unit 2-84
2-23 Estimated Operating and Maintenance Costs -of the
Sunbury Steam Electric Station Baghouse 2-U5
3-1 Troubleshooting Chart for ESP Operation 3-39
3-2 Summary of Problems Associated with ESP's 3-46
4-1 Summary of Inlet Particle Size Distribution Data 4-4
4-2 Nomenclature for Electrostatic Precipitator
Computer Model 4-6
4-3 Cold-Side Electrostatic Precipitator - Cost of
Fine Particulate Control 4-18
'••i
4-4 Hot-Side Electrostatic Precipitator - Cost of
Fine Particulate Control 4-19
4-5 Costs for Overall Mass and Fractional Effi-
ciencies of Cold-Side ESP on Boilers Burning
Eastern Bituminous Low-Sulfur (0.6%) Coal 4-20
4-6 Costs for Overall Mass and Fractional Effi-
ciencies of Hot-Side ESP on Boilers Burning
Western Subbituminous Low-Sulfur (0.6%) Coal 4-20
xii
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LIST OP TABLES (Cont'd)
No. Pages
4-7 Comparison of Cold- and Hot-Side ESP's on Boilers
Burning Eastern Bituminous Low-Sulfur (0.6%) Coal 4-23
4-8 Comparison of Cold- and Hot-Side ESP's on PC
Boilers Burning Western Subbituminous Low-Sulfur
(0.6%) Coal 4-23
4-9 Predicted Performance of Chemico Venturi Scrub-
bers in Collection of Fine Particles 4-33
4-10 Predicted Performance of Research-Cottrell
Flooded-Disc Scrubber in Collection of Fine
Particulate 4-35
4-11 Predicted Performance of OOP TCA Scrubbers in
Collection of Fine Particulate 4-37
4-12 Predicted Performance of Krebs-Elbair High-
Pressure Spray Scrubber in Collection of Fine
Particulate 4-39
4-13 Predicted Performance of Wet Scrubbers in
Collection of Fine Particulate from Coal-Fired
Utility Boilers 4-41
4-14 Summary of Fractional Efficiency Test Data for
Wet Scrubbers Operating on Coal-Fired Boilers 4-47
4-15 Results of Particulate Sampling at Nucla 4-54
4-16 Results of Particle Sizing at Nucla 4-56
4-17 List of Variables Analyzed in Nucla Study 4-64
4-18 Results of Particulate Sampling at Sunbury
Steam Electric Station 4-67
4-19 Penetration and Outlet Concentration 4-68
4-20 Inlet and Outlet Mass Median Diameters 4-69
5-1 Advantages and Disadvantages of Using Precipi-
tators on Coal-Fired Utility Boilers 5-2
xiii
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LIST OP TABLES (Cont'd)
No.
5-2 Advantages and Disadvantages of Using Wet
Scrubbers on Coal-Fired Utility Boilers 5-3
5-3 Advantages and Disadvantages of Using Fabric
Filters on Coal-Fired Utility Boilers 5-4
xiv
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SUMMARY
Although the specific health effects of fine particu-
late emissions are still under investigation, our knowledge
of their capability for penetration deep into the human
respiratory system warrants immediate consideration of
control measures. This report is concerned with control of
fine particulate emissions from coal-fired utility boilers,
which represent a large-scale emission source. Three classes
of conventional control devices are considered: electro-
static precipitators, wet scrubbers, and fabric filters.
The report is organized into three major sections, which
cover (1) control device design, (2) operation and mainten-
ance procedures, and (3) relationship of fractional collec-
tion efficiency and costs to other operating parameters.
CONTROL SYSTEM DESIGN PARAMETERS
Numerous factors enter into selection of a control
system for a specific application, however, they can be
categorized as those related to (1) emission rates specified
by Federal, state, and local regulations, (2) particle
characteristics (electrical, physical, chemical), (3) gas
stream characteristics (temperature, pressure, velocity,
etc.), (4) site restrictions, and (5) costs of control.
xv
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Electrostatic Precipitators (ESP' s)
When considering an ESP design, it is necessary first
to define a proposed installation in terms of certain known
or determined factors:
0 Type of coal (moisture, ash, sulfur, other con-
stituents)
0 Ash chemical analysis
0 Particulate bulk electrical resistivity
0 Type of boiler (pulverized-coal-fired, stoker-
fired, cyclone-fired) and resulting particle siae
distribution
0 Total gas throughput (acfm)*
0 Applicable emission standard Or regulation
Prom these known factors, two basic design parameters
stand out as the most influential in the precipitator de-
sign:
0 Specific collection area (SCA, collection area:
ft2/1000 acfm)
2
0 Power density (watts/ft of collecting area)
Specific precipitator design parameters (see Table 2-4)
include:
0 Precipitator capacity
0 Type of rappers, electrodes, etc.
Although it is the policy of EPA to use the metric system
for quantitative descriptions, the British system is used in
this report. Readers who.are more accustomed to metric
units are referred to the conversion table on page xxv.
XVi
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0 Electrical energization values for each section
0 Performance-related parameters
Given these parameters, the following items can be
estimated:
0 Mass and fractional collection efficiencies
0 Capital and operating costs
Considerable information is presented in the form of
equations for computation of such factors as precipitator
size, plate height, treatment velocity, ducting, section-
alization, and energization. In addition, graphical cor-
relations are presented for selected combinations of boilers
and coal to relate the input variables to optimum design and
to capital and operating costs. A modified migration veloc-
ity (w,), first proposed by Matts and Ohnfeldt is used to
estimate SCA requirements for cold and hot precipitators.
The modified migration velocity is an improvement over the
standard Deutsch Anderson migration velocity (w), since once
the particle size distribution is known, w, can be treated
as a constant for a given application whereas w can not be.
The modified migration velocity is used almost exclusively
by the Australian power industry, and its usage is on the
increase in the United States.
Because of the larger amounts of smaller-sized par-
ticles and increased carbon carryover, cyclone boilers are
xvi i
-------
shown to require higher SCA's than pulverized boilers. This
applies to both cold- and hot-precipitators and on all types
of coal, although to a lesser extent on lignite coal. The
SCA requirements for cold precipitators on bituminous and.
subbituminous coal vary with" the percent sulfur in the fly
ash; for lignite, the percent Na^O governs SCA requirements.
The SCA's required for hot precipitators are in.a much
narrower band than those for cold precipitators, and depend
on the Na20 and Fe2°3 contents of the fly.ash. - *
Power density for bituminous pulverized-coal applica-
tions is influenced by the sulfur content of* the coal. Low-
sulfur coal produces a reduction-in maximum power density
achievable compared with high^sulfur coal, and requires
additional plate area to compensate. ;t , «
For lignites, Ha^O influences the design power density
in much the same manner as does the sulfur content of bitu-
minous coal, although to a lesser extent.
The considerations that weigh heavily in the evaluation
of hot-side versus cold-side precipitator applications are
coal constituents, mode of firing, and temperature effects.
Wet Scrubbers ;
Three major categories of wet scrubbers are evaluated:
0 Gas-atomized spray scrubbers including the con-
ventional venturi and the flooded-disc venturi.
xvi 11
-------
0 Three-stage turbulent-contact absorber (TCA), also
known as a moving-bed scrubber.
0 Preformed spray scrubber.
Assuming that the same factors are known or determined
for scrubbers as are indicated for the analysis of precipi-
tators, the following key design parameters have the great-
est effect on the efficiency of the scrubber:
0 Pressure drop
0 Liquid-to-gas (L/G) ratio
0 Gas velocities
Other specific design parameters include the following:
0 Gas-handling capacity per module
0 Total number of modules required
0 Water requirement/water recirculation
0 Availability of equipment/downtime
0 Total power consumption as a fraction of generated
power
A detailed checklist (Appendix C) is provided to use in the
evaluation of a wet scrubber design for collection of par-
ticulate; these design parameters are also summarized (Table
2-9) as they pertain to wet scrubbers now operating in the
United States.
Graphical correlations were not developed for scrubbers
because the data base was inadequate.
xix
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Fabric Filters
Only three fabric filter systems are MOW operating
domestically for particulate collection on coal-fired
utility boilers. The key design factors for fabric filtra-
tion systems are air-to-cloth ratio, pressure drop, cleaning
mode, frequency of cleaning, composition and wea-yse *©£ fabric,
degree of sectionalization, type of filter homsiaig, and gas
conditioning or cooling requirement. These design data for
' the three utility-size fabric filter systems operating in
the United States are summarized .(Table 2-16),, and capital/
operating costs are presented for these installations.
OPERATION AND MAINTENANCE PROCEDURES
This section of the report provides a set .<&£ procedures
for operation and maintenance of precipitators, wet scrub-
bers, and fabric filter systems installed on coal-fired
utility boilers. The procedures presented for precipitators
are much more detailed than those for scrubbers or fabric
filters. Preoperational checklists, start-up procedures,,
and the salient features of efficient normal operation,
troubleshooting, inspection, and maintenance are presented
for each of the three types of control systems; common
malfunctions are also discussed, particularly with respect
to precipitators.
In precipitator operation, which is based on the elec-
trical charging and collection of particles, the components
xx
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and controls associated with transformer-rectifier sets,
rappers, and vibrators are the heart of the system. Because
the precipitator incorporates high-voltage components,
particular emphasis is given to safety considerations,
including proper connection and grounding. Inspection and
maintenance procedures are directed toward achieving reli-
able functioning of the total precipitator system, including
electrical/mechanical components. An extensive trouble-
shooting chart (Table 3-2), lists the symptom, probable
cause, and remedy for numerous ESP malfunctions, the most
/
common of which are discharge wire breakage and ash hopper
plugging.
Scrubber operation in removal of particulates from
power plant effluent has encountered its own characteristic
problems, including a potential for corrosion, scaling, and
plugging. These problems emphasize the need for research
and development of scrubber technology. The operating/
maintenance procedures outlined here are designe4 to mini-
mize malfunctions. Problem areas that require frequent
inspection are summarized for each scrubber type; adherence
to manufacturer's recommendations as they apply to each
specific system/unit is urged. In normal operation, effi-
ciency of a scrubber system for collection of submicron
particles is related most closely to maintaining proper
levels of pressure drop and L/G ratio.
xxi
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A lack of historical data on fabric filter operation
limits the determination of the effects of operating and
maintenance procedures on baghouse efficiency. On the basis
of available data, operations at the Sunbury fabric filter
installation are discussed briefly. Maintenance'practices
are focused on surveillance to detect and prevent potential
problems. Visual inspection-of the stack emission, smoke-'
density instruments, and pressure-drop recorders are used to
indicate malfunctions. : *
Most maintenance time at Sunbury has been spent on bag
replacement, collapse fan repairs, and air-operated1 dampers.
Procedures are outlined for isolation of a malfunctioning
compartment and performance of repairs and maintenance;
detection of collapse fan and damper failure are also dis-
cussed.
FRACTIONAL EFFICIENCY RELATIONSHIPS
This section deals further with the major variables
that define a specific application (coal type, boiler type),
relating them to efficiency of the control device for col-
lection of particles of specified size. A computer model is
used to predict percentage of particle penetration as a
function of particle size. Predictive modeling is limited,
however, by the deficiency of currently available methods
for measuring particle size distribution, pointing out the
xxn
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need for development of a reliable technique for fine-
particle measurement. Such a technique is a prerequisite
for future compliance monitoring of fine-particle emissions.
Mathematical models for determining fractional effi-
ciency as applied to ESP's and wet scrubbers are described.
Predicted performance is presented graphically, and wherever
possible is compared with actual performance data.
The computer models for precipitators show a minimum of
efficiency in the particle size range of 0.2 to 0.4 micron.
This observation is verified by field tests (Figures 4-5
through 4-7). If properly designed, precipitators are par-
ticularly efficient in the collection of particles in the
submicron range.
The computer models for wet scrubbers show predicted
performance down to a particle size of 0.2 micron, at which
level they show minimal efficiency. Although precise com-
parison is not possible because of the lack of accurate
particle size data the gas-atomized spray scrubber is pre-
dicted to perform better than either the TCA or high-pressure
spray-type scrubbers. Test data on venturi and TCA scrubbers
generally confirm the results of the computer model; however
the test data do not indicate that the gas-atomized spray
scrubber will perform better in every instance than the
other types of scrubbers, as predicted by the computer
model.
xxiii
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For hot and cold side precipitators, on the basis of
stated assumptions/ capital and operating costs for given
levels of total mass and fractional efficiencies for a
variety of coal and boiler types are summarized, fhese cost
comparisons show a precipitator on a pulverized boiler to be
cheaper than on a cyclone boiler at equal overall mass
efficiency levels, and show the hot side precipitator to be
more economically attractive to a cold precipitator on
either a pulverized or cyclone fired bedler. All precipi-^
tator cost comparisons underscore the faet that total mass
as well as fractional efficiency should be considered when
establishing standards for control of fine partieulate,
regardless of the control device b©ii*g considered*
xxiv
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METRIC CONVERSION FACTORS
To convert
English units
Multiply
by
To obtain
SI units
British thermal unit (Btu)
Cubic foot (ft3)
Degrees fahrenheit
Foot
Gallon (U.S. Liquid)
Gallon (U.S. Liquid)
Horsepower (hp)
Inch
Inch
Inches of water
Pound
Ton, short
1054
0.0283
5/9 (°F-32)
0.3048
0.0038
3.7854
746.0
0.0254
2.54
248.8
0.4536
0.9072
Joule (j)
3
Cubic meter (m )
Degrees Celsium (C)
Meter (m)
3
Cubic meter (m )
Liter (1)
Watt (w)
Meter (m)
Centimeter (cm)
Pascal (pa)
Kilogram (kg)
Metric ton (kkg)
xxv
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1.0 INTRODUCTION
1.1 PURPOSE OF REPORT
This report presents a set of guidelines by which
operators of coal-fired electric utility boilers and environ-
mental control personnel can (1) select a feasible parti-
culate control method for a specific application to comply
with air pollution control regulations, (2) follow opera-
tional and maintenance practices that will maintain high
particulate collection efficiencies and minimize malfunc-
tions, and (3) relate the total mass efficiencies of various
control devices to their efficiencies for collection of
particulate in specific size fractions.
The high-efficiency control devices considered in this
report for use on coal-fired power plant boilers are hot and
cold electrostatic precipitators, wet scrubbers, and fabric
filters.
It should be noted that the vast majority of coal-fired
electric utility boilers in the United States that control
particulate emissions are equipped with precipitators,
either alone or in series with a mechanical collector.
Consequently, much more information is available on the
design, operation and maintenance, and fractional efficiency
1-1
-------
of precipitators than of wet scrubbers or fabric filters in
this application. The availability of information accounts
for the relatively greater depth of coverage of preeipita-
tors in some sections of this report.
1.2 SIGNIFICANCE OF PARTICULATE EMISSIONS
Many undesirable effects have been related to the
discharge of particulate matter into the atmosphere. Par-
ticulates constitute a health hazard, cause poor visibility,
function as a transport vehicle for gaseous pollutants, and
(in many cases) are highly active both chemically and
catalytically.
Concerning the health effects of particulates, the
severity and scope of the problems caused by submicron
particulates are not yet well defined. Fine particulates
constitute a large category of pollutants rather than toeing
a single pollutant. Once dispersed, they behave (depending
on size) similarly to coarse particles and gases; they
remain suspended and diffuse, are subject to Brownian motion,
follow fluid flow around obstacles, and can penetrate deep
into the respiratory system.
Particles larger than 5 microns diameter are deposited
in the nasal cavity or nasopharynx. Increasing numbers of
smaller particles are deposited in the lungs, where Over 50
•>
percent of the particles between 0.01 and 0.1 micron pene-
1-2
-------
trating the pulmonary compartment are deposited. This
ability of participates to penetrate the respiratory system
and be captured is mainly a function of their geometry
rather than their chemical properties. In addition, parti-
cles in these smaller size ranges are difficult to measure.
The resulting health effects of the captured fine
particulates depend largely on their chemical or toxic
qualities, excepting for long, fibrous materials whose
physical qualities also provide potential for irritation of
tissue. Because of the many factors as yet unknown, it is
unwise to generalize concerning health effects of fine
particulates.
1.3 SCOPE OF THE REPORT
Section 2.0 of the report discusses control system
design parameters. Experience with control device operation,
engineering judgment, and current design practice provide
the data base for discussion of electrostatic precipitator
design, relating input variables to basic design variables.
The discussion of design parameters for wet scrubbers
includes venturi, flooded disc, turbulent contact absorber
(TCA), and high-pressure spray scrubbers. This discussion
is based primarily on the detailed presentation of Sondreal
2
and Tufte .
The use of fabric filters for control of particulates
1-3
-------
from coal-fired boilers is a recent alternative; data are
available for only three installations.
Section 3.0 describes maintenance and operational pro-
cedures that contribute to operation of the particulate
collection devices with maximum efficiency. The discussion
emcompasses start-up, shutdown, and normal operational
procedures; common malfunctions are also discussed.
The fractional collection efficiencies of ESP's, wet
scrubbers, and fabric filters are discussed in Section 4.0.
Reliable data on particle size distribution are not readily
available because of the high degree of operator error and
the technical limitations of some particle sizing instrumen-
tation. Because awareness of the potential adverse health
effects of fine particulates is relatively recent, programs
for systematic measurement of particle size distribution
have been undertaken only in the past few years.
The particle size distribution data available for this
study show an appreciable amount of scatter in the mean and
standard deviation of size distributions for the same coal/
boiler application. Although coal type does influence
particle size distribution, the effect of boiler type is
stronger. Therefore, values for coal type, boiler type,
overall mass collection efficiency, and typical particle
size distribution data selected on the basis of boiler type
1-4
-------
were used to develop computer models to predict fractional
efficiencies of ESP's and wet scrubbers. For ESP's and
scrubbers the predicted data are compared with actual operat-
ing data.
A computer model is not presented for predicting frac-
tional efficiencies of fabric filters, only test data.
Section 5.0 presents conclusions regarding the use of
precipitators, scrubbers, and fabric filters on coal-fired
utility boilers. Advantages, disadvantages, and costs to
install and operate each type of control device are com-
pared. The effectiveness of each device in collecting fine
particles is also discussed.
1-5
-------
2.0 CONTROL SYSTEM PARAMETERS
2.1 SUMMARY OF CONTROL DEVICES
Among the utilities in the United States producing (as
opposed to buying and selling) electric power through year-
end 1975, there were 1166 coal-fired units (boilers).
Approximately 582 of these are equipped with pollution
control devices designed to operate with an overall mass
particulate collection efficiency of 95 percent or greater.
A list of these installations is presented in Appendix A.
Of that number, approximately 75 percent of the units have
cold-side electrostatic precipitators, 16 percent have a
mechanical collector and a cold-side precipitator, 7 percent
have hot-side precipitators, 1.5 percent have wet scrubbers,
and 0.5 percent have mechanical collectors only. In addi-
tion, three fabric filter systems are collecting fly ash
from coal-fired utility boilers.
Hybrid systems are certainly of interest, but for a
number of reasons their consideration exceeds the practical
limits of this document. For example, the reason for use of
hybrid systems is primarily the tightening of emission
regulations, often requiring addition of a control system to
one already in operation. This patchwork approach, in which
2-1
-------
control devices are added in series or in parallel, does not
constitute a sound basis from which to generalize concerning
optimum design of hybrid systems. Therefore, this document
deals only with cold-side and hot-side electrostatic preci-
pitators; wet scrubber systems including venturi, flooded
disc, turbulent contact absorbers (TCA), and high-pressure
spray scrubbers; and fabric filters.
The information presented on electrostatic precipita-
tors consists of current design relationships. It is based
on designs that have met or surpassed guaranteed efficiency.
Current design practice is considered rather than historical
data because design is influenced strongly by time-related
factors. Among the factors influencing changes in design
practice are the Clean Air Act of 1970 (as amended), pro-
vision of increased control device reliability as a result
of vendor competition, and increased attention to coal
composition, thereby strengthening the basis for electro-
static precipitator design.
The primary source of data on wet scrubbers for this
study is "Scrubber Developments in the West" by Sondreal and
2
Tufte. This source includes the operating experience of
the Four Corners Station of Arizona Public Service; the Dave
Johnston Station of the Pacific Power and Light Company; the
Valmont, Cherokee, and Arapahoe Stations of the Public
2-2
-------
Service Company of Colorado; and the Clay Boswell and Aurora
Stations of the Minnesota Power and Light Company.
The use of fabric filters for emissions control in
coal-fired power plants is limited to three utility plants,
located at Nucla, Colorado; Sunbury, Pennsylvania; and
Holtwood, Pennsylvania.
2.2 COMPARISON OF ALTERNATIVE CONTROL SYSTEMS
2.2.1 Selection and Evaluation
A number of factors must be carefully weighed in selec-
tion of a control device for a specific application. Some
of the important considerations are presented in Table 2-1.
These factors apply in general to precipitators, wet scrub-
bers, and fabric filters. When a device is installed and
operational, its performance can be compared with that of
other devices in operation. The performance of conventional
control equipment is currently judged with respect to over-
all mass collection efficiency. As discussed in Section 4
of this report, fractional efficiency and overall effi-
ciency, both on a mass basis, should be considered in estab-
lishing fine particle emission standards.
2.2.2 Economic Rationale for Evaluating Costs
A number of methods are available for determining the
cost competitiveness of different devices, utilizing such
concepts as discounted cash flow, present worth, and capi-
2-3
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Table 2-1. FACTORS BEARING ON CONTROL DEVICE
SELECTION
Characteristics of
particles and gas stream
Facilities, costs, legal
factors
Particle characteristics
Electrical properties
(precipitators only)
Resistivity
Dielectric constant
Physical properties
Surface properties
a. abras iveness
b. porosity
Density
Shape
Hygroscopic nature
Adhesivity
Cohesivity
Chemical properties
Ignition point (preci-
tators, fabric filters)
Chemical composition
Particulate concentration
Size distribution
Gas stream characteristics
Flowrate
Temperature
Pressure
Viscosity
Chemical composition
Acid constituents
Alkaline constituents
Sulfur oxide content
Moisture content
Plant facility
Waste treatment
Space restriction
Product recovery
Water availability
Cost of control
Engineering studies
Hardware
Auxiliary equipment
Land
Structures
Installation
Start-up
Power
Waste disposal or recycle
Water
Materials
Gas conditioning
Labor
Maintenance
Taxes
Interest on borrowed capital
Depreciation
Insurance
Return on investment
Regulations
Maximum .particulate and S02
emission rates allowed by
Federal, state, and local laws
2-4
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talized cost. A simple approach based on the rate of return
on incremental investment to determine the economically
superior control device is presented below.3
As an illustration, let T. and Tn be the capital in-
A 13
vestments required for control devices A and B, respectively,
for a specific application (e.g. 99.5 percent overall mass
collection efficiency for fly ash particles having a resis-
tivity of 10 ohm-cm) . Let the corresponding total annual
operating costs be 0A and 0_.
A o
If TA < TB and OA < OB, it is obvious that control
device A is more economical. Similarly, control device B
would be clearly more attractive if TA > T and OA > 0 .
However, if T_, > T and 0D < Oa, the choice can be made on
13 A D A
the basis of annual savings that can be realized when the
additional investment is made. Thus, the incremental in-
vestment of (T_. - T ) for control device B yields an annual
3 **
savings of (CL - O ) compared with control device A.
°A- °B , ,
If m - - T
^B A
where Z is the desired (or acceptable) return on investment,
then it is profitable to invest in device B.
Alternatively, if (OA - 0B)/(Tfi- TA) < Z, then control
device A is preferable. This is because additional capital
2-5
-------
required for device B (i.e., Tfi - TA) can be invested else-
where, so that the return on the additional investment of
(T - Tn) is greater than the acceptable limit of Z.
B A
2.3 DESIGN CONSIDERATIONS - ELECTROSTATIC PRECIPITATQRS
This section of the report is intended to provide
insight into the major parameters that must be weighed in
design of an electrostatic precipitator. The basic proce-
dure is a simple one; given certain input variables (coal
type, boiler type, and emission standard) and applying
experience and theory, one can arrive at a design that meets
the criteria for efficiency and cost. The procedure is
summarized in Table 2-2.
An application can be characterized in a very general
way by a coal type and a boiler type. The available litera-
ture provides an enormous number of possible application
areas that might be defined. The following list summarizes
some of the important types of coal currently used by
utilities and their characteristics.
Low-sulfur western (subbiturainous and bituminous)
High and low sodium
High moisture
High ash
High and low calcium + magnesium
Low-sulfur eastern (bituminous)
Low sodium
High and low iron
High and low silica + alumina
High and low magnesium + calcium
2-6
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Table 2-2. DESIGN CONSIDERATION FOR AN ESP
System input
Coal type
Boiler type
Federal or state emission standard
Basic design parameters
Total acfm
Total collection area
Power density
Specific design parameters
Firing method and coal characteristics
Ash chemical analysis
Precipitator size
Rapping, electrodes, etc.
Electrical energization
Performance parameters
System output
Overall and fractional mass efficiency
Capital cost
Operating cost
2-7
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High-sulfur (bituminous)
High and low sodium
High and low iron
Lignite
High and low sodium
High moisture
Low sulfur
Following are the major types of boilers now used by utilities;
Pulverized-coal-fired
Wet bottom
Dry bottom
Stoker-fired
Spreader
Underfeed
Cyclone-fired
Screened
Open
Within the constraints of availability of data and
desirability of keeping the application areas to a manage-
able number, the following scheme has been adopted for
discussion of the graphical correlations presented later in
Section 2.0. For cold-side electrostatic precipitators the
overall mass efficiency levels are 95, 97,5, 99, 99.5, and
99.9 percent. The major applications are (1) pulverized*
coal-firing of bituminous, subbituminous, and lignite coals,
and (2) cyclone firing of bituminous coal. The influencing
coal characteristics are sodium and sulfur contents (for
lignites and low-sulfur coals in general).
2-8
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For hot-side electrostatic precipitators at the same
efficiency levels, the major applications are pulverized-
coal and cyclone firing of typical western (subbituminous)
and eastern (bituminous) coals. The influencing coal
characteristics are percent iron and sodium oxides.
In most cases the graphical correlations presented
represent a range of values that could extend above or below
the plotted curve.
Table 2-3 provides an approximation of expected emis-
sions from the boiler types under consideration. With some
refinements in the inlet fly ash characteristics, Section
4.0 provides a comparison of precipitator performances for
the different application areas at various levels of frac-
tional and overall mass collection efficiency. The capital
and operating costs associated with attaining those levels
are also provided.
2.3.1 Basic Design Parameters
The objective is to determine from coal type, boiler
type, and emission standard the values for gas volumetric
2
throughput (acfm), total plate collection area (ft ), and
2
power density (watts per ft of collecting plate). These
three parameters form the basis for precipitator design.
2-9
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Table 2-3. EMISSIONS FROM DIFFERENT BOILER TYPES
Boiler
Stoker
Cyclone
Pulverized-
coal
Loadings
Low to medium,
depending on
coal ash
Low
High to medium,
depending on
coal ash and
type bottom
Particle
size
Coarse ,
20%<10ym
Fine,
80%<10um
Medium,
50%<10ym
Combustible
content in
fly ash,%
40-60
10-30
<5
The total gas volume to be treated is known, since it
is determined by the conditions of combustion. (Conditions
of time, temperature, and turbulence of combustion together
with precipitator approach ductwork determine the degree of
turbulence of the gas to be treated, a matter of no small
consequence in performance of an electrostatic precipitator.
In the discussion of design that follows, it is assumed that
generation of large-scale turbulent eddies due to structural
design of approach ductwork and hoppers has been minimized).
Knowing the total acfm and the specific collection area
2
(SCA, ft /1000 acfm}, one can determine the total collection
area required to meet an emission standard. Following are
the equations for calculating SCA and required efficiency:
2-10
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SCA = 16.67 In2(l-n)
Wk
n = [i - ( —s * )] 100
(10 /H.V.)(ASH)(A.C.)
where
n = Overall mass collection efficiency, percent
w, = Modified migration velocity/ ft/sec.
i\.
X = Emission standard, lb/10 Btu
H.V. = Heating value of the coal, Btu/lb
ASH = Ash in the coal, fraction by weight
A.C. = Ash carryover, fraction by weight
The required overall mass efficiency, therefore, is a
function of the coal heating value and ash content as well
as the fraction of ash carryover, which is a function of
boiler type. The modified migration velocity is a function
of electrical energization of the precipitator, gas proper-
ties, and particle size entering the precipitator. It is
often conveniently linked with resistivity level, such that
for a moderate resistivity of 109 ohm-cm the value will be
between 1.6 and 1.9, ft/sec whereas for a very resistive
dust it may approach 0.5 ft/sec.
A digression is in order at this point to clarify the
usage of w (modified migration velocity) in contrast to the
*V .
effective migration velocity w, which is used in the conven-
2-11
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tional Deutsch-Anderson efficiency equation. The effective
migration velocity w is a function of several factors,
including precipitation length, overall mass collection
efficiency, and gas velocity. The variation in w within a
given precipitator is caused by changing particle si*e
distribution, as precipitation proceeds in the direction of
gas flow.
The modified migration velocity, w, , as presented by
4
Matts and Ohnfeldt can be treated as independent of chang-
ing current and voltage levels, and particle size distribu-
tion within a precipitator as the precipitation process
proceeds in the direction of gas flow. However, changes
in the properties of the dust entering the precipitator
(resistivity, size distribution) produce a change in w, just
as they also change the conventional w. This report does
not present actual values of vt.y it only explains the
method by which w, is used in the modified Deutsch-Anderson
equation.
The third basic design.parameter is power density
required to establish the necessary voltage-current char-
acteristics of the corona, given the fly ash entering the
precipitator. Power density is a function of electrical
resistivity, particle size and gas composition, gas tempera-
ture, and gas pressure. It is often conveniently linked
with resistivity, such that for a moderate resistivity of
2-12
-------
10 ohm-cm the value will be approximately 2.5 watts/ft2.
For a high-resistivity application the design value will be
in the neighborhood of 0.5 to 1.0 watt/ft2.
It appears that resistivity plays a significant role in
selection of wfc and power density, yet there is no precise
method of predicting resistivity from the coal type and
firing conditions for the numerous cold-side applications.
2.3.2 Specific Design Parameters
Table 2-4 is a compilation of design parameters and
input variables grouped in logical categories.
Information from the first two categories has been used
in definition of the design approach. The last category,
performance-related parameters, includes two of the basic
system design parameters. As explained in Section 4.0, this
category will help to define the system output parameters
and the overall and fractional mass collection efficiencies
for various application areas. The remaining categories,
precipitator size; rapping, electrodes, etc,; and electrical
energization, are discussed in the following subsections.
Precipitator Size
One of the first structural parameters to be determined
is the width of the precipitator (s) . This value is depen-
dent on total number of ducts, which is calculated as follows,
ACFM
Total no. ducts =
(T,V.) (60) (P.S.) (P.H.)
2-13
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Table 2-4. DESIGN PARAMETERS AND DESIGN CATEGORIES
FOR ELECTROSTATIC PRECIPITATORS
Firing method and
coal characteristics Ash chemical analysis
Firing method Si02
% ash A1°<>
% sulfur
t moisture (as received) TiO,
Btu/lb (wet) CaO
Sample source MgO
ASTM class K20
Mine, state Na2O
Mine, county Li 20
Nine name P2°5
Seam name 803
Sample source
Mean
Deviation
Precipitator capacity Sample type
No. precipitators
No. chambers (units) /precipitator
No. ducts/chamber (unit)
Duct spacing
Plate height
Treatment length
Section lengths and total no. of each (per
precipitator)
Collecting area
No. electrical sections parallel to gas flow
(per precipitator)
No. electrical sections across gas flow (per
precipitator)
No. hoppers parallel to gas flow (per precipi-
tator)
No. hoppers across gas flow (per precipitator)
Rapping , electrodes ( etc .
Type discharge electrode
Ft. discharge electrode/vibrator or rapper
Type discharge electrode vibrator or rapper
Type collecting electrode
Sq ft collecting electrode/rapper
Type collecting electrode rapper
Electrical energization (of each electrical section)
Watts/ft2 of collecting electrode
of collecting electrode/T-R
Mode (switching)
Corona kilovolts ,
Mill iamperes/1 000 ft of collecting electrode
Milliamperes/T-R
Milliamperes/ft2 of discharge electrode
Performance-related parameters
Gas flow
Gas temperature
Gas (treatment) velocity
SCA
Overall mass collection efficiency
Fractional mass collection efficiency
Inlet grain loading
Outlet grain loading
Generated plant power output
Fuel burning rate
2-14
-------
where, ACFM = Total gas volumetric throughput, acfm
T.V. = Gas (treatment) velocity, fps
P.S. = Plate spacing, ft
P.H. = Plate height, ft
Treatment velocity (T.V.) is a function of resistivity of
the fly ash. Values of T.V. should range from 3.0 to 4.0
fps in high-resistivity, in cold-side ESP applications, and
in low-resistivity applications (hot-side or cold-side).
For most other applications the values should range from 3.0
to 5.5 fps.
Plate spacing (P.S.) is more or less fixed by the
precipitator manufacturer and his experience with different
types of fly ash and by velocity distribution across the
precipitator, as well as the plate type. Plate spacing
usually ranges from 6 to 15 inches. Most precipitators in
the United States have 9-inch spacing, but precipitator
designers are now showing a great deal of interest in larger
spacings.
Plate height (P.H.) is selected from consideration of
simultaneously maintaining the required treatment velocity
and also maintaining an adequate aspect ratio, which is the
ratio of the length of a precipitator to its height.
Historically, this value varies between 0.5 and 1.5, with a
present-day average of approximately 1.3. Plate heights
usually range from 24 to 45 feet. The practical limitation
on plate height imposed by structural stability is obvious.
2-15
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Each manufacturer limits the practical plate heights in
accordance with his overall design.
The total number of ducts indicates the width of the
box. What is required now is some indication of chamber-
wise sectionalization of the precipitator* as indicated in
Figure 2-1. Chamber-wise (parallel) sectionalization is
sectionalization across the gas flow, whereas series sec-
tionalization is in the direction of gas flow.
4TH SECTION
3RD SECTION
2ND SECTION
1ST SECTION
OL
UJ
CM
0£.
LU
CO
o
CO
oc
UJ
CD
O
(DIRECTION OF GAS FLOW
INDICATED BY ARROW)
Figure 2-1. Sectionalization of the precipitator,
2-16
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A practical procedure from the standpoint of energiza-
tion and reliability is to limit the total number of ducts
per unit. A precipitator will have a number of chambers
determined by the total number of ducts, which itself is
determined from Eq. 1 and its associated criteria. The
total number of precipitators needed will depend upon the
degree of reliability required, space limitations at the
utility site, and relative ease with which the effluent gas
may be distributed to the precipitator(s) .
The second general design equation provides a guide to
the length of the precipitator. As mentioned before, the
length is dependent on the selection of treatment velocity,
plate spacing, plate height, volumetric throughput, and
total collecting plate area.
Treatment _ _ -
Length ~ Eq* 2
total collecting plate area
(no. precip.)(chambers/precip.)(ducts/chamber)(P.H.)(2)
The design treatment length will be determined by selection
of an integer value of standard section lengths that may be
i
offered by the precipitator manufacturer. If it is found,
for example, that four sections are required, two of one
length and two of another, the structural considerations
such as hopper spans determine the positioning of the sec-
tions in the direction of gas flow. The size of the T-R*
Transformer-rectifier set.
2-17
-------
sets is selected to provide lower current density at the
inlet, where corona suppression is likely to decrease col-
lection efficiency, and higher current density at the outlet,
where there is a greater percentage of fine particles.
Mechanical sections result from the chamber-wise and
section-wise sectionalization of an electrostatic precipi-
tator. Hopper selection is based upon the size of the
mechanical sections.
Rapping, Electrodes, etc.
The geometry of the discharge electrodes (fine, barbed,
rigid, etc.) will determine the current-voltage character-
istics. The smaller the wire or the more pointed its sur-
face, the greater the value of current for a given voltage.
Typical values for length of discharge wire per vibra-
tor or rapper are 3300 feet for hot-side applications and
3000 feet for cold-side applications. These values, however,
should not be taken as absolute because actual practice
varies widely and values range from 2500 to 3500 ft per
vibrator or rapper, ^
For cold-side precipitatprs, 2000 square feet of col-
lection area is a typical value 'for one rapper. For hot-
side applications, the value is typically 2500 square feet
per rapper. Again, there is a wide variation in actual
\
practice, and values range from 2000 to 3000 ft per rapper.
2-18
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Baffles are used to provide stiffness for support of
the collecting plate and a region of low turbulence to
minimize reentrainment of fly ash, particularly during
rapping. Although a variety of plates is commercially
available, their functional characteristics are not substan-
tially different.6
Rappers can be pneumatic, electromagnetic, or mechani-
cal. Single-impact (magnetic-impulse, gravity-impact)
rappers are often used. The rapping intensity is determined
by the height of the rapper when released from its elevated
position and by the plunger weight. The weight of the
plunger may range from 8 to 32 pounds. The frequency of
rapping is essentially determined empirically by observing
the values of opacity and overall mass efficiency measured
as the intensity of rapping is varied.
Mechanical rappers are lifted by means of a rotating
shaft to which a number of rappers are attached. Impact can
be provided in a horizontal direction. Intensity and fre-
quency of raps are determined by the weight of the rapping
hammers and shaft speed, respectively.
Electrical Energization
The way in which a precipitator is energized strongly
affects its performance. Electrical energization involves
the number and size of the transformer-rectifier (T-R) sets,
2-19
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the number of electrical sections, half wave-full wave (HW-
FW) operation, and changes in the voltage-current character-
istics as precipitation proceeds in the direction of gas
flow.
Selection of design power density is often conveniently
based on resistivity of the fly ash. Table 2-5 illustrates
design values of average power density as a function of
resistivity.
Table 2-5. DESIGN POWER DENSITY
Resistivity, ohm-cm
10
4-7
10
10
7-8
9-10
Power density,
watts/ft2 of
collecting plate
4.0
3.0
2.5
2.0
1.5
1.0
For a cold-side precipitator an average operating
voltage may be between 25 and 45 KV for 9-inch spacing,
whereas for a hot-side precipitator typical values range
from 20 to 35 KV for 9-inch spacing. Knowing power density
and operating voltage, one can estimate the current density
2 2
(ma/ft ). The value of ma/ft of collecting electrode is
not constant for each point in the precipitator. At the
2-20
-------
inlet section, where the dust loading is greatest, the
voltage-current characteristics differ significantly from
those at the outlet, since the probability of corona sup-
pression is greater at the inlet and the percentage of fine
particles is greater at the outlet.
A mechanical section by definition may become an
electrical section if it can be separately energized.
Within an electrical section one may have a chamber-wise or
section-wise high tension split, or both (see Figure 2-2).
SECTION-WISE
CHAMBER-WISE
CHAMBER-WISE
SECTION-WISE
f I f
(DIRECTION OF GAS FLOW INDICATED BY ARROW)
Figure 2-2. High-tension splits of a mechanical section.
2-21
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The advantage of splitting a mechanical section both chamber-^
and section-wise is greater reliability; this is achieved at
an increase in cost. - :;':!
Reliability increases with the degree of-sectionaliza-
tion in the direction of gas flow. For a precipitator that
is highly sectionalized in the direction of gas flow, ran-
domly generated failure patterns generally produce a pre-
dicted efficiency in a narrower band than for a precipitator
with less sectionalization in the direction of gas flow. > ,
Reliability of the precipitator is involved not only
with sectionalization of a given collection area but -also
with the addition of collection area or electrical sections.
At the discretion of the designer and in accordance with
specifications of the utility, the degree of reliability can
be defined in terms of a redundant capacity, which is .a
function of anticipated failure and time between maintenance
periods. In this context, redundancy may be defined as that
additional area in a precipitator that compensates for the
"normal" level of unavailable collecting area. How much
additional area will be required is a function of the utility
fuel specifications and the designer's experience with the
fuel(s). To provide a reliable yet cost-competitive design,
the designer must have detailed information, such as ulti-
mate, proximate, and ash chemical analyses for all potential
fuels.
2-22
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The basic consideration in energizing the precipitator
is to maximize the power input to achieve the highest effi-
ciency from a given collection area. The decision regarding
degree of sectionalization, however, is made independently
of the way in which the precipitator is to be energized,
since the number, size, and mode of operation (half wave or
full wave) of the T-R sets can be manipulated to provide the
required current density within each electrical section of
the precipitator. Following is a brief commentary on the
rationale for half wave-full wave operation.
In spark-limited operation on a cold-side precipitator
treating high-resistivity ash, half-wave operation allows
time during the off half cycle to recover from the sparking
condition (spark quenching). Complete decay of the charging
field and of collection efficiency during the off half cycle
is avoided because of the capacitive effect of high-resis-
tivity fly ash, which tends to maintain the field potential.
In operation of hot-side precipitators, since fly ash
resistivity has been reduced by virtue of the increased
temperature of operation, the capacitive effect of the fly
ash is reduced. Thus the charging field decays more in
half-wave than in full-wave operation.
Selection of the mode of operation depends somewhat on
site-specific factors; in fact the variability of perform-
ance in full-scale precipitators may overwhelm any differ-
2-23
-------
ences due to operation in either half-wave or full-Wave
mode.
In summary, the design of precipitator sectionalizatioh
and energization is based on maximizing the powet input to
the precipitator to achieve the highest efficiency from a
given collection area while minimizing loss of performance
as a result of various failure patterns* Reliability of
precipitator performance is a function of fuel specifica-
tions, utility requirements* and design experience« The way
in which a precipitator is energized depends on the sec*-
tionalization configuration and the current 'density to fee
supplied to each electrical section, as determined fey chemi-
cal and physical characteristics of the fly ash* dust load-
ing, and characteristics of the gas stream* The number,
size, and mode of operation of the T-R sets dan be fitted to
the sectionalized configuration after the bus section design
has been established.
2.4 INTERPRETATION OF GRAPHICAL CORRELATIONS FDR OOLD-
AND HOT-SIDE ELECTROSTATIC PRECIPITATORS
%•
The preceding discussion of precipitator design shows
that three parameters are of central interest: gas vblu-
2
metric throughput (acfm); total collecting area (ft ); and
2
power density (watts/ft of collecting plate). The graphi-
cal correlations discussed in this section relate input
variables to these basic design variables and to the capital
2-24
-------
and operating costs for each case. As indicated earlier,
the designer's judgment, experience, and understanding of
precipitator theory allow him to select the values of over-
all mass efficiency, SCA, and power density required for
given coal type, boiler type, and Federal emission standard.
A word of caution is needed however. It is not intended
that the broad-based approach presented here should provide
information that can be directly applied to a specific site
or installation. A number of highly practical points must
be considered in the overall design, including such nonideal
conditions as gas nonisoturbulence, gas sneakage, and par-
ticle reentrainment. In addition, many points of detail are
to be considered in electrical energization and structural
design.
The data presented in the graphs are based on current
design practice. The SCA values are shown for various
coal/boiler applications and efficiency levels in relation
to sulfur, percent Na20, and percent Fe203 in the fly ash.
For this study, sufficient data were not available on the
cyclone firing of subbituminous and lignite coals or on
power density relationships for hot-side precipitators to
develop correlations. Also, data were insufficient to allow
meaningful correlations with regard to stoker-fired boiler
applications.
2-25
-------
Current design and/or performance data are also pre-
sented for comparison with the graphical correlations. If
SCA values for the design data are based on the conventional
Deutsch-Anderson migration velocity (w), direct comparison
with the graphical correlations is difficult because they
are based on the modified migration velocity (w, ). As
stated previously, the modified migration velocity is an
improvement over the conventional migration velocity, since
•;';••
once the particle size is determined, w, can be treated as a
.; ~! K
constant for a given application; w cannot be treated as
such. The modified migration velocity is used almost ex-
clusively in the Australian power industry where they have
found that well-designed and maintained precipitators in-
variably conform closely to a w, relationship. Actual test
points from an intensive series of pilot tests at Waller-
awang, Australia, in 1969, as well as actual full-load
installations, have shown the validity of the w, concept.
2.4.1 SCA as a Function of Significant Ash Constituents
Cold-Side Electrostatic Precipitators
For bituminous coal (pulverized-coal and cyclone-fired)
and subbituminous coal (pulverized-coal-fired) the sulfur
content is very important in determining the SCA required
since it affects resistivity. Recall that the governing
equation for SCA is
2-26
-------
SCA = 16-67 In2(l -n)
wk
As the percent sulfur decreases, resistivity increases, WR
decreases at a given temperature, and the SCA increases.
With very high resistivities, one can expect a value of wfc
approaching 0.5 ft/sec. The utility will sometimes specify
that a slightly inflated value of SCA be used to provide a
degree of redundancy or reliability so that a more stringent
future emission standard may be met relatively easily. In
other instances, the utility may specify additional treat-
ment length. The expression of the redundant capacity may
vary, but the result is the same.
Figures 2-3 and 2-4 present SCA as a function of sulfur
content of bituminous coal for pulverized-coal and cyclone
firing, respectively.
The SCA's required for cyclone firing of bituminous
coal (Figure 2-4) are 30 to 40 percent higher than those for
pulverized-coal firing. The fly ash emitted from a cyclone-
fired boiler is approximately 20 to 30 percent of the total
coal ash produced upon combustion, whereas for a dry ash
pulverized-coal-fired unit it is about 80 percent. Even
though less ash is carried over to the precipitator with the
cyclone-fired boiler, the particle size distribution makes
precipitation difficult (compare x = 6.0 and o = 3.33 for
2-27
-------
700
600
500
*
o
400
300
200
100
99.9
Coal: Eastern bituminous
Boiler: Pulverized coal
Note: each curve represents
a band of values that
could be expected to de-
viate above or below the
curve.
99.5
99.0
95.0
'1.0
2.0 3.0
SULFUR IN COAL, %
4.0
Figure 2-3. SCA versus sulfur content:
cold-side-ESP, pulverized eastern.bituminous.
2-28
-------
700
o
o
o
CSJ
5
oo
600
500
400
300
200
TOO
Coal: Eastern bituminous'
Boiler: Cyclone
99.9
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
J.
1.0 2.0 3.0
.SULFUR IN COAL, %
Figure "2-4. SCA versus sulfur content:
cold-side ESP, cyclone-fired eastern bituminous.
4.0
2-29
-------
cyclone firing with x = 12 and a = 3.8 for pulverized-coal
p
firing). Also, the increased carryover of unburned carbon
from a cyclone boiler can adversely alter the precipitabil-
ity of the fly ash. Carbon particles tend to reentrain more
easily than fly ash particles. Since the carbon particles
are more conductive, they tend to discharge upon contact
with collection electrodes and become reentrained.
Table 2-6 presents a number of design parameters for
precipitators recently specified by the Tennessee Valley
Authority (TVA) for compliance with various state particu-
late emission regulations. The coal supply for all of these
plants will probably be eastern bituminous, and all of the
boilers are pulverized-coal-fired. The method by which
these precipitator specifications were prepared is not
known.
Assuming that the coal is bituminous, all but one of
the SCA requirements as a function of coal sulfur content
appear to lie within the range of the curves presented in
Figure 2-3. The SCA of 672 for an efficiency of 98.5 per-
cent with 0.6 percent sulfur bituminous coal at Bull Run
appears rather stringent. It may be that these precipita-
tors are designed for western coal.
It should be noted that since all of the TVA precipita-
tors are retrofit designs, the inlet concentrations may
2-30
-------
Table 2-6. PRECIPITATOR PARAMETERS RECENTLY SPECIFIED BY TVA
to
I
u>
Plant name
Bull run
Gallatin 1 & 2
Gallatin 3 & 4
Johnsonville 1-6
Kingstone 1-4
Kingston 5-9
Colbert 5
Widows Creek
Shawnee 1-10
No.
of
units
1
2
2
6
• 4
5
1
6
10
NO.
Of
precips.
4
2
2
6
4
5
2
6
10
Boiler
type
PC
PC
PC
PC
PC
PC
PC
PC
PC
Efficiency
specif ied,%
98.5
99.5
99.5
98.7
99.2
99.2
99.5
99.6
98.0
Gas flow,
acfm
2,800,000
700,000
816,000
575,000
500,000
700,000
2,000,000
575,000
584,000
Coal3
Sulfur,
%
0.6
1.5
1.5
2.0
0.9
0.9
1.5
0.7
1.0
Ash,
%
22
28
28
18
25
25
25
30
27
SCA
ft2/1000 acfm
672
386
386
220
450
450
325
495
345
New or
retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Retrofit
Bituminous.
-------
differ from those which would be typical of a new precipita-
tor design; therefore, comparison with Figure 2-3 should be
made with this in mind.
At sulfur contents about 1.5 to 2,0 percent, the SCA
requirements of eastern bituminous and western subbituminous
pulverized coals are similar. Below this range, a dramatic
increase in SCA is noted as percent sulfur in the coal
decreases, especially for the subbituminous pulverized
coals, mainly because most experience on subbituminous is
with western coals high in resistive components like Ca and
Mg, as shown in Figure 2-5. The SCA requirement (SCA-488)
for precipitators on Units 1 and 2 at the Jim Bridger
pulverized-coal-fired generating station is plotted on
Figure 2-5. This station fires low sulfur subbituminous
western coal. When Unit 1 was tested in April, 1975, the
collection efficiency ranged from 99.5 to 99.6 percent
(99.3% guaranteed) with all gas paths in service. The
Matts-Ohnfeldt modified migration velocity (wfc) was used in
9
sizing this precipitator. The requirement for high-SCA
cold-side electrostatic precipitators causes one to consider
the advantages of a hot-side electrostatic precipitator (see
next section).
SCA values for boilers firing pulverized lignite are
shown in Figure 2-6 as a function of sodium content of the
2-32
-------
£
u
«\J
1200 -
1100 -
1000 -
Coal: Western subbituminous
Boiler: Pulverized coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
JIM BRIDGER STATION:
SCA FOR UNIT 1 @ 99.3%,
0.6% S COAL
2.0 3.0
SULFUR IN COAL, %
Figure 2-5. SCA versus sulfur content:
cold-side ESP, pulverized western subbituminous.
2-23
-------
800
700
.600
500
o
CM
400
300
200
TOO
Coal:
Boiler:
Lignite
Pulverized
.Coal
Note: each curve represents
a band of values that could
be expected to deviate above
or below the curve.
1.20 2.40 3.60 4.80
Na20 IN LIGNITE, %
99.9
6.00
7.20
Figure 2-6. SCA versus sodium content: cold-side
ESP, pulverized lignite.
2-34
-------
lignite. Although the data on cyclone boilers are inade-
quate for plotting, it was found with one specific lignite-
fired cyclone boiler that increasing percentage of sodium in
the coal apparently (1) fused other constituents in the ash
and caused retention of ash in the boiler; (2) produced
coarser fly ash particles; (3) lowered the electrical resis-
tivity of the fly ash; and (4) improved the optical proper-
ties of the stack plume. If, as is indicated in (2) the fly
ash particle is coarser, then one would not expect a differ-
ence in SCA requirements for cyclone and pulverized-coal
firing of lignite as great as that for cyclone and pulver-
ized-coal firing of bituminous coal (recall 30 to 40 per-
cent) . The precipitator design and operating data shown in
Table 2-7 for power plants burning North Dakota lignite seem
to bear out this observation; however, this table does not
show a comparison between new cyclone and pulverized-coal
firing boilers designed by the same company.
The general class of western coals presents a problem
in selection of a design SCA value for cold-side electro-
static precipitators. The effect of resistivities exhibited
by ashes of these coals is complicated by the high proba-
bility of back corona. Also, as mentioned previously, the
unburned carbon particles emitted from cyclone boilers can
be a significant factor in design for firing of both eastern
and western coals.
2-35
-------
Table 2-7.
ESP DESIGN AND TEST DATA FOR POWER PLANTS BURNING
NORTH DAKOTA LIGNITES9
Utility company
Station
Location
Boiler capacity, MH
firing method
ESP vendor
Hew or retrofit
installation.
Completion, date.
Flue gas
temperature, *F
volume, 10OO acfur
velocity in ESP, fps
Specific collection
area, ft2/1000 acftn
Number of TR sets
Collecting surface/TR
set, ft2
Collecting- surface/
Rapper, ft?
Inlet loading, gr/acf
Outlet loading, gr-/acf
Design efficiency, %
Measured efficiency, t
Migration velocity
390
5.07
23*
*
3,07S
2560
2.0>
5.015
)8.50
99*
9.9-
Ortonville
Ortonviile,
Minnesota
21
Spreader-
stoker
Research
Cottrell
Retrofit
6/72
3*5
1J3
4.25
280
4
310
2!07'0
O.S7
0.0042
9ff.90
99*
tf.41-
Biq Stone
Milbank,
South Dakota
440
CYC
wheel-abrator
New
5/75
288
2330
5.25
355
24
34,400
,1120
1.17
0.014
5S.80
ESP downstrea»; of mechanical collector.
' Data not available.
Only outlet loading has been measured to date.
-------
Hot-Side Electrostatic Frecipitators
In contrast to the situation with cold-side electro-
static precipitators, the design SCA for a hot-side electro-
static precipitator at a gas temperature of about 700°F is a
strong function of the iron and sodium contents of the fly
ash. In general, eastern coals will have relatively high
iron content (ranging from 5 to 40 percent with a moderate
value of around 9 percent) and relatively low sodium content
(0.2 to 1.2 percent). Western subbituminous coals charac-
teristically have lower iron contents, in the neighborhood
of 5 percent Fe~O,, a percentage that would be a moderate to
high for lignite coals. Figure 2-7 shows that with pul-
verized-coal firing, design SCA's for eastern low-sulfur
coals are lower than those for western low-sulfur coals.
The higher SCA's in western coal applications result from
the lower amounts of conductive constituents, namely iron
and sodium, in western coals. Generally the influence of
iron content on SCA is greater than that of sodium content
because the differences in iron content of eastern and
western coals are greater. The SCA's for cyclone firing, as
shown in Figure 2-8, are again typically 30 to 40 percent
higher than for pulverized-coal firing, the skewness of
particle size distribution being responsible for the differ-
ence.
2-37
-------
500
u
10
o
o
o
CM
5
. to
400
300
200
100
Western Coal:
Eastern Coal:
= 5-
= 9.
Boiler: Pulverized coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
99.9
1.0
2.0
3.0
Figure 2-7. SCA versus sodium content: hot-side
ESP, pulverized-coal firing.
2-38
-------
600
500
400
u
IB
o
CM
5
to
300
200
100
0
Western Coal:
Eastern Coal:
Boiler: Cyclone
to
the
% Fe203 = 5-
% Fe203 = 9-
Note: each curve repre-
sents a band of values
that could be expected
deviate above or below
curve.
99.9
99.9
1.0 2.0
N»20 IN COAL, %
3.0
Figure 2-8. SCA versus sodium content: hot-side ESP,
cyclone firing.
2-39
-------
A hot-side precipitator may overcome the potential back
corona problem prevalent with cold-side precipitators, but
introduces two additional problems, Higher gas temperature
causes an increase in the gas volume flow rate by slightly
over 50 percent (assuming 700 and 300°F temperatures for
representative hot-side and cold-side precipitators/ respec-
tively) . This increased gas volume would require a greater
collection area than is needed for a cold-side precipitator
with the same SCA. Furthermore, the higher temperature
increases the current density and reduces the sparkover
voltage associated with the lower gas density. The result
is operation of the precipitator at reduced voltages, with a
concurrent reduction in the effective migration velocity,
again requiring additional plate area although higher cur-
rent levels can partially offset the effect of operating at
reduced voltages. Both of these effects are offset by the
lower SCA requirement associated with the higher temperature
of operation because of reduced resistivity (often by 2
orders of magnitude). Performance data as shown in Figure
2-9, as well as the correlations presented in this report
verify the reduced SCA requirement for hot-side precipitators,
The decision to select a hot-side or a cold-side preci-
pitator is based on economics. This must be carefully
*•
evaluated for each application.
2-40
-------
to
I
«
O
z
LU
o
H-l
u.
I f
Lt,
LU
LECTION
o
o
99.98
99.96
99.94
99.9
99.8
99.6
99.0
98.0
97.0
96.0
95.0
90.0
85.0
80.0
70.0
i i 1 I i w i 1 1 1 1 I
_ _
1 J*l =
•• i* .
•:Xr* *
••"**• •
•
**
— -
LEGEND _
UNIT SIZE, OPER. TEMP., FUEL REGION SULFUR, * ~~
m 575-660 EAST. BITUM. 2.8
* 1000 580 - 610 EAST. BITUM.
_ • ^ 206 669 - 681 EAST. BITUM. 0.9 - 1.6 _
t • 248 645 - 650 EAST. BITUM. 1.4-1.9
• 52 700 - 710 ILLINOIS 2.5 - 3.1
_ 30 595 KENTUCKY _
* 66-77 620 - 650 KENTUCKY 0.67 - 1 .06
•• 299 670 MONTANA (DECKER) 0.33
~ 299 670 WYOMING (ARCH MIN) 0.52 - 0.77 ~
360 947 HYOMING (AMAX) 0.26 - 0.42
1 1*1 1 1 1 1 1 1 1 1
60 80 TOO 200 300 400 500 600 800 101
SCA, FT2/1000 ACFM
Figure 2-9. Performance versus SCA of hot-side precipitators.
-------
2.4.2 Power Density as a Function of Significant Ash
Constituents
Power density is a function of electrical resistivity,
particle size, gas temperature, gas composition, and gas
pressure. The value for typical design power density for
pulverized-coal firing of bituminous coal is presented in
Figure 2-10 for cold-side precipitators.
With high-sulfur-content coal, the fly ash is more
conductive. This situation is characterized by high current
and moderate working voltage. Since the milliamp rating
determines the size of the transformer-rectifier sets, the
T-R sets are large in anticipation of the great power demand
of the highly conductive fly ash. With low sulfur content
and higher resistivity (low conductivity) the current and
voltage are lower. The initial effect in high-resistivity
cases is increased sparking, requiring a voltage reduction
in order to hold a designated spark rate. Lower corona
current and power input does cause a decrease in efficiency
''..-• ' • •.
for a given collection area. In order to compensate for
lower power, the particle residence time is increased; this
entails increasing the size of the precipitator until the
total power requirements for the desired efficiency are met.
Note that the corona power per precipitator is lower, but
increased area increases the total corona power to the
desired level. For this reason the effect of efficiency on
power density is not shown in Figure 2-10.
2-42
-------
0
§
LU
CD
t—t
LU
8
u.
o
t
to
LU
o
DC
£
£'
6.00
5.40
4.80
4.20
3.60
3.00
2.40
1.80
1.20
0.60
0.
Coal: Eastern bituminous
Boiler: Pulverized coal
_L
_L
o.
1.20 2.40 3.60
SULFUR-, %
4.80
6.00
Figure 2-10. Power density versus sulfur content:
cold-side ESP, pulverized eastern bituminous.
2-43
-------
The reasoning above applies similarly to the firing of
pulverized lignites (Figure 2-11). Here, however, the
effect of sodium content governs the design power density.
A correlation for cyclone firing of bituminous coal is
unavailable. Carbon carryover is responsible for higher
power inputs than in pulverized-coal firing, but the magni-
tude of the shift cannot be demonstrated. The presence of
smaller particles with cyclone firing can reduce corona
power by suppressing corona current at a given voltage
through space charge phenomena. Submicron particles of
fairly high loadings would be necessary to produce a signi-
ficant effect. The increased conductivity of the particle
cloud due to the presence of unburned carbon, however, more
than offsets the small-particle effect.
Although the values are not plotted, it can be expected
that at sulfur contents above 1.5 to 2.0 percent for firing
of pulverized subbituminous coal the relationship between
percent sulfur and power density is similar to that in
pulverized bituminous coal applications. Below 1.5 percent
sulfur, the effect of sodium content is overriding, and high
sodium content will induce high power.
In general, an increase in gas temperature reduces gas
density, reduces sparkover potential, and increases the rate
of rise of current with voltage. For hot-side electrostatic
2-44
-------
i
UJ
6.00
5.40
4.80h
CD
p 4.20|-
o
u_ 3.60J
o
00
UJ
ca
of.
UJ
3.00
2.40
1.80
1.20
0.60
0.
0. 1.20
Coal: Lignite
Boiler: Pulverized
coal
JL
2.40 3.60 4.80 6.00
Na20, %
Figure 2-11. Power density versus sodium content;
cold-side ESP, pulverized lignite.
2-45
-------
precipitators (up to 1000°F), the net result is that in-
creased gas temperature will likely yield an increase in
power density.
2.4.3 Cost as a Function of Power Plant Output
Cost models were used to develop capital and operating
costs on a consistent basis for cold-side and hot-side
electrostatic precipitators for the various application
areas as a function of plant power output (MW). These costs
are presented graphically in Appendix B; Figures B-l through
B-12 present capital cost and Figures B-13 through B-24
represent annualized operating costs. Capital cost in $/kW
represents the flange-to-flange installed capital cost to
the user (December 1975). The values include costs for the
basic collector, foundation, engineering, and erection;
costs for approach ductwork and fans are not included.
Operating cost in mills/kWh includes annual labor cost,
annual maintenance cost, power cost, and annual capital
charges. The capital charges are based on depreciation at 7
percent of capital investment (service life of the control
device, 15 years) and an interest rate of 12 percent. The
total interest charge over the life of the equipment is
obtained by summing the annual interest charges on the
undepreciated investment. It can be shown that the average
annual interest charge is (X/2) percent of the initial
2-46
-------
capital investment when the interest rate is X. Thus, based
on these assumptions the annual capital charge is 13 percent
of the capital investment.
The unit electricity cost is assumed to be 3.0 cents/
kWh. Required operating availability of the electrostatic
precipitator as a function of boiler availability, is taken
at 85 percent (7446 hours/yr).
The many cases defined in Figures B-l to B-24 are
summarized in Table 2-8 with respect to the increase in cost
and SCA associated with the controlling ash constituent for
a given application. In line with the increase in SCA with
the change from cyclone to pulverized-coal firing of bitu-
minous coal (usually 30 to 40 percent, may be as high as 85
percent), one would expect a constant increase in cost
(Cases 1 and 2). The increase in cost is fairly constant
irrespective of boiler power output, that is, +2 percent.
The dramatic increase in SCA, capital cost, and oper-
ating cost for Case 3 is somewhat misleading. One would not
expect to find a subbituminous coal with 3.0 percent sulfur,
in the U.S.A. In general, however, the costs do increase
markedly at low sulfur levels and high efficiencies. The
high resistivity of the fly ash requires conservatively low
apparent migration velocities on the order of 0.6 to 0.75
ft/sec.
2-47
-------
Table 2-8. TRENDS IN CAPITAL AND OPERATING COSTS OF ESP'S AS A FUNCTION OF COAL
AND BOILER TYPES ( AT 99.5 PERCENT OVERALL MASS COLLECTION EFFICIENCY)
to
I
42.
00
Case
1
2
3
4
5
6
7
8
Coal type
Bitum.
Subbit.b
Lignite
Western0
Eastern
Western
Eastern
Boiler
type
PCe
CYC
PC
PC
PC
PC
CYC
CYC
ESP
type
Cold
Cold
Cold
Cold
Hot
Sot
Hot
Hot
Direction of change
of coal constituent
causing increase in
cost
3.0 -0.6% sulfur
3.0 0.6% sulfur
3.0 0.6% sulfur
6.0 1.2% Na20
2.0 0.2% Na,0
A
2.0 0.2% Na2O
2.0 0.2% Ma20
2.0 0.2% Na2O
Increase in
SCA as a result
of decrease in
sulfur or Na20
83
83
155
236
56
56
56
56
Increase in cost, %a
Capital
cost
70
70
125
101
48
48
48
48
Operating
cost
34
34
75
77
43
43
43
43
Reference
figure no.
Capital
cost
B-l
B-2
B-3
B-4
B-5, B-6
B-7, B-8
B-9, B-10
B-ll.B-12
Operating
cost
B-13
B-l 4
B-15
B-16
B-l 7, B-18
B-19, B-20
B-21, B-22
B-23, B-24
a The increase in capital cost over the entire range of plant power outputs considered
for a given decrease in % sulfur or % Na.O is fairly constant and may vary at most
by +2%. *
b The sulfur range for this case is somewhat misleading. One would not expect to find
a subbituminous coal with 3.0% sulfur. Therefore, the value cited for cost increase
is hot particularly meaningful.
0 5% Fe2O3 content with % Na2O ranging from 0.2 to 2.0.
d 9% Fe203 content with % Na2O ranging from 0.2 to 2.0.
e Pulverized-coal-fired boiler.
Cyclone-fired boiler.
-------
2.5 DESIGN CONSIDERATIONS - WET SCRUBBERS
Various categories of wet gas scrubbers are available
on the market today. Within each category are numerous
design variations, each manufacturer offering his own de-
sign. Thus, selection of a particular scrubber for a spec-
ific job is a complex task. Some of the wet scrubbers are
specially designed and recommended for particulate collec-
tion rather than gaseous absorption. The following discus-
sion, briefly describes four types of wet scrubbers that are
2
operating on western coal utilities for particulate removal:
0 Chemico Venturi Scrubber 1 -
0 Research Cottrell's Flooded-disc Scrubber
0 UOP Three-stage TCA (Turbulent Contact Absorber)
0 Krebs-Elbair High-pressure Spray Scrubber
Table 2-9 presents a summary of operating parameters for wet
scrubbers in the western United States.
For a specific job, the scrubber is judged by its
performance in removing particulate matter over a given
range of particulate size. Of course, consideration is
given also to the amount of net energy spent to clean a unit
mass of gas per unit time. With the increasing stringency
of permissible emission limits in recent years, special
interest is now focused on collection efficiencies of fine
particles in the size range 5 pm and below.
The key parameters affecting particulate collection for
all scrubbers are pressure drop, liquid/gas ratio (L/G),
2-49
-------
particle size distribution, and gas velocities. Besides
these key parameters, the following general information is
also required to justify the choice of equipment:
General Parameters
a) Gas handling capacity/module
b) Total number of modules required
c) Capital cost
d) Annual operating cost
e) Water requirement; water recirculation
f) Availability of the equipment; necessary downtime
g) Indication of fractional collection efficiency of
the device
h) Total power consumption as a fraction of the
generated power.
The following paragraphs describe the four types of wet
scrubbers, emphasizing the variables that influence their
performance. This discussion, together with the available
2
operating data, should provide information useful to
utility operators in considering installation of Wet scrub-
bers for particulate removal.
2.5.1 Category 1; Chemico Venturi
In conventional terminology, this device is also called
a gas-atomized spray scrubber. The collection process
mainly relies upon acceleration of the gas stream to provide
impaction and intimate contact between the particulates and
t
fine liquid droplets generated as a result of gas atomiza-
tion. This is a high-energy-consuming device designed for
high-efficiency particulate collection* Typically, the
pressure drop in utility use is on the order of 20 inches of
2-50
-------
water or more. Collection efficiency increases with pres-
sure drop and ratio of liquid to gas circulation. There is,
however, an optimum L/G value above which additional liquid
rate is not effective at a given pressure drop. In this
device the pressure drop can be increased by increasing the
gas velocity. The high gas velocities, which can reach
40,000 fpm, cause a high rate of wear. Not enough evidence
is available to indicate the superiority of this device for
fine particulate removal as applied to coal-fired boilers.
Concerning the earlier-mentioned parameters relevant to
scrubber operation, not enough data on this device are
available to allow full evaluation. The available operating
data are given in Table 2-9.
2.5.2 Category 2: Research-Cottrell Venturi, Flooded-Disc
' Scrubber:'•
In Research-Cottrell's flooded-disc scrubber, the
primary mechanism for particulate removal is impaction.
Slurry and flue gas pass through an orifice whose area
depends upon the vertical position of the disc. The result-
ant shearing force will create slurry droplets, which com-
bine with particulate. The system pressure drop is a func-
tion of the gas velocity in the orifice and, to a lesser
degree, the liquid velocity in that region. Although the
efficiency of particle collection increases with increasing
pressure drop, the inlet particle size distribution will
2-51
-------
Table 2-9. CONDENSED SUMMARY OF OPERATING WET SCRUBBERS IN
WESTERN UNITED STATES
£32*: ;:::::::::;:
Oeaioji
Tiring Method . i
He. of equipped boilers. ....
Ho of scrubber nodules
Installed scrubber capacity. HH.
Hottest? - * • . * . .
Coal
Ash In coal, t
Calciun oxide in ash t •
Open or cloMd loop. . ,.,...
Mater reo,uires»nt. acra ft/yr. .
ACre-ft/M* yr
Elec, power requiroMnt, NH. . .
Elec. power, t of 9eneratifm
Manpower, total operators. . - .
Inlet dv*t loadiao. or/scfd. . .
SOj reeoval , % . 4 , . . .
•articulate coll. off.. «...
Public
Service
Pour
Corner*
12/71
Par t i cul ate
Cheaico
Vkntiuti
PC
3
£
575
fee
No
S3
Wt eabbit
ft. 68
22
4
9
11
Open
3,400
S.91
20
3-4
•
12
($0
t* 2
10
•0
99.2
Pacific
Power and
Lieht
Dave Johnaton
plant
4/72
Ctteitico
Vwnturi
PC
j
3
330
Ho
Ho
24
MY eobbit
0 5
12
ZO
13
U
Intermittent open
BOO
2.42
7-1
j j
HA
4
500
0 04 ar/Bcf eitit
HA
«.o
PublJ
Valeent
station
UOP
3— etaoe TCA*
j
2
in
Yea
90
Ify gyMiit
O.S
3 2
20
SO
1«-15
Open
340
2.M
6
S 09
NA
o.t
soo
0 02 ar/*cf exit
40
•0
«.75
c Service cowpany
of Colorado
Cherokee
atation
j
6«0
jj
CO Mftw
O.t
• 4
5
SO
10-15
Open
1,900
2.95
2C.4
4.00
•ft
0.4 to O.I
500
0.02 ar/acf exit
20
59-15
95.0*97.5
Arapahoe
station
112
fl
Ify f|||ffrjt
0 t
S 2
20
SO
10-15
Opm
300
2. fit
4.5
4 02
.3
$00
0 02 9r/*cf evit
40
JO-40
97.5
NiHMMOta Power
Clay Bomell
plant
5/73
spray
150
NT aAbit
0 9
9
11
|
4
Open
1,500
4.29
3
o.t*
HA
3
•00
99
20
MA
99
and Uefet
Aurora
plant
«/71
•pray
n*
NA
Mr subbit
o •
9
11
§
4
Open
3,500
30.2
1
fi.U
MA
2
•00
9t
20
MA
91
Southern
California
Idiaon
nohave
station
11/73
S02
Lime
So. Cal. Edison
4 -stage spray*
170
210
l.Jt
2.7
t
0.07
Arisen
Public
Service
Choi la
station
10/73
SO? and
Particulate
Lis*etone
tovera
115
45 to rower
203
i.n
2.1
4
1.1
Nevada
Power
Company
Me id Gardner
atation
3/74
SOj and
particulate
aoda ash
•quip. Aaeoe.
wash trayd
250
550
2.20
2.4
««
4
0.1 ta O.I
NontaM-Oehota
Utilitiea
bawls and Clark
atation. Unit
12/75
psrticulate
LiMstone
flooded disc*
Pulverised coal
55
17 (based on outlet)
114
2.1
0.9
a
1.4 laverao*)
N)
I
t v>
Metallic*! collector «nd *l.ctroatatie prceipitator.
fro. m in mi koll*rt 170 iw •ojoimnwt aerittktr «M
ir. 40 p«rc.Bt to CSP.
by « »0 p«rc«lit «((lci*fit
ky M PWMM *f<4eMilt *chiiiie«l eolUetor.
coll«ctor.
-------
determine the gas and liquid velocities required to achieve
the desired overall mass collection efficiency.
Since venturi scrubbers generally require higher energy
input than other types of wet scrubbers used for particulate
collection, accurate determination of the optimum pressure
drop is required. Therefore, the liquid-to-gas ratio, gas
velocity, disc position, and inlet particle size distribu-
tion are all important parameters to consider.
2.5-3 Category 3; UOP, Three-Stage TCA Scrubber
This device is also known as a moving-bed scrubber, for
11 12
which design details are available in the literature. '
In principle, dusty gas passes upward through a bed of
spheres, which may or may not go into a fluidized state
depending upon the gas velocity and the density of the
spheres. Scrubbing liquid is sprayed from above the spheres,
resulting in formation of a turbulent zone around the spheres,
In the UOP design, lightweight hollow plastic spheres go
into random motion with the formation of a turbulent layer
above the sphere as a result of gas flow. Dust enters the
scrubber at the bottom countercurrently, contacts the main
liquor, and bubbles with the liquor upward through the tur-
bulent layer. Inertial impaction and interception are the
primary collection mechanisms. The solid particles that are
captured by the liquid are drained out the bottom of the
scrubber. Energy consumption of this device is relatively
2-53
-------
low, with a typical pressure drop of 4 inches of water per
stage and L/G ratio approximately 20 to 25 gpm per 1000 cfm.
Although the device is not as efficient as the venturi
scrubber for particulate removal, it has definitely better
gas absorption characteristics. Provision of additional
stages does not improve particle collection. The special
advantage of the system is high throughput gas velocities,
up to 1100 fpm. In addition to the general parameters for
wet scrubbers, the following are key variables for TCAs:
a) Diameter of the collecting sphere
b) Gas viscosity, temperature
c) Stage height, (height of the expanded bed)
d) Interstitial gas velocity (depends on the effective
bed porosity)
\"''tl-1'" ':' . ••'' '"£' •
•'.is'Si..,; " • • ..^
Some of these variables are given in the operating
data, Table 2-9.
2.5.4 Category 4; Krebs-Elbair Scrubber
This device is also categorized as a preformed spray
scrubber. High-pressure spray nozzles (100 to 200 psig) are
used to generate liquid droplets (300 to 600 urn in diameter),
which are projected at high velocity against a membrane in
•:(.• •.'".-:
the direction of gas flow. The membrane is made up of
vertical bars closely spaced to act as Venturis. The spray
nozzles are arranged so that a rebound zone of fast-moving
drops is established at the membrane surface. When the
dirty gas enters the scrubber, the solid large particles are
captured by the high-speed water drops (concurrent flows),
2-54
-------
mainly by the impaction mechanism. At the membrane the gas
is suddenly accelerated, acting as linear Venturis to do
more scrubbing. Particle size distribution has a signifi-
cant effect on the overall performance. Theoretically, the
device can be considered as a hybrid scrubber, a combination
of a concurrent spray tower and a venturi scrubber with the
following important key variables:
a) Nozzle type
b) Average droplet size generated
c) Orientations of nozzles
d) Liquid flow rate per nozzle
e) Speed of the droplet
f) Average droplet number and density
g) Gas residence time
h) Length of the concurrent flow path
i) Linear size of the membrane opening
Gas retention time is very low, on the order of 2 to 3
seconds. Gas throughput velocities are very high, up to 600
fpm. Because of the low retention time, diffusional forces
are not very effective in capturing submicron particles. In
general, the device is not efficient enough to compete with
a high-pressure venturi scrubber. The main disadvantage of
this device is potential plugging of the nozzles. The gas
pressure drop is on the order of 3 to 4 inches of water.
There is excessive pressure drop across the nozzles, however.
A checklist for obtaining design and operating data on
scrubbers used for particulate control is presented in
Appendix C.
2-55
-------
2.5.5 Costs for Particulate Scrubbers
Capital Costs
Available capital costs for operating particulate only
scrubbers, as summarized in Table 2-9, range from $30/kW to
$52/kW.
Detailed cost information is provided by Ensor et al.'
on the Unit 3 particulate scrubber at the Cherokee Station-
The total cost of the scrubber was $4,400,000, or $29/kW,
based on a nameplate rating of 150 MW. This figure repre-
sents the total installed cost of the scrubber, which was
completed in 1972. The 1975 cost of the same scrubber would
be about $5,800,000, and with modification for better per-
formance and availability would increase to $7,370,000, or
$49/kW. Table 2-10 presents a breakdown of the capital
costs of the Cherokee Unit 3 particulate scrubber-,
Annual Costs for Scrubbers
Ensor et al. has also provided a detailed analysis of
the operation and maintenance costs for the Cherokee Unit 3
particulate scrubber. The estimates are for direct costs
only and do not include items such as general plant overhead
or charges against capital (depreciation, interest, taxes,
etc.). The total direct operating costs are approximately
$495,000/year. Based on 75 percent availability of the
scrubber, this amounts to a cost of 0.50 mills/kWh. These
costs are summarized in Table 2-11.
2-56
-------
Table 2-10. CHEROKEE NO. 3 SCRUBBER
CAPITAL COST BREAKDOWN
1972 DOLLARS13
Account
Excavation and earthwork
Concrete
Structural steel and buildings
Process equipment
Scrubber vessel
Ductwork
Presaturator
Scrubber fans and motors
Sootblowers
Sootblowing air compressors
Reheater
Dampers and isolation gates
Recirculation pumps and motors
Miscellaneous pumps and motors
Stack lining
Instrument air compressors
Monitoring equipment
Miscellaneous equipment
Piping
Electrical
Painting
Instrumentation
Insulation
Indirect field costs (includes
field supervision and payroll
expenses; construction supplies;
temporary facilities; demolition;
construction equipment)
PSCC overhead costs
Engineering
Pre start-up and revisions
Post start-up and maintenance
Contractor fee
Interest during construction
TOTAL
Installed cost
$ 19,100
100,800
324,300
$463,900
224,600
65,600
194,900
50,700
56,100
42,200
53,400
48,900
6,500
86,900
10,700
16,400
16,500 1,337,300
235,000
444,300
28,000
263,900
110,700
385,000
74,600
404,400
67,800
143,800
369,000
69,300
$ 4,377,300
Percent
0.4
2.3
7.4
30.6
5.4
0.2
0.6
6.0
2.5
8.8
1.7
9.2
1.6
3.3
8.4
1.6
100.0
2-57
-------
Table 2-11. CHEROKEE NO. 3 SCRUBBER OPERATING COSTS (1972)
13
1
-------
Annualized operating costs for other operating parti-
culate scrubbers are not available.
2.6 DESIGN CONSIDERATIONS FOR FABRIC FILTERS
Fabric filters are basically simple devices. The re-
moval of particulate from waste gases is accomplished by
forcing the gases to flow through the fabric filter media
which removes the particulates by one or more of the follow-
ing mechanisms:
(1) Inertial impaction
(2) Diffusion to the surface of an obstacle because of
Brownian diffusion
(3) Direct interception because of finite particle
size
(4) Sedimentation
(5) Electrostatic phenomena
Parameters that are important in fabric filtration
system design include air-to-cloth ratio, pressure drop,
cleaning mode and frequency of cleaning, composition and
weave of fabric, degree of sectionalization, type of hous-
ing, and gas cooling. Each of these factors is discussed
briefly below, and available data are tabulated for the
fabric filters now installed in utility plants.
2.6.1 Air-to-Cloth Ratio
A major factor in the design and operation of a fabric
filter, the air-to-cloth (A/C) ratio is the ratio of the
quantity of gas entering the filter (cfm) to the surface
area of the fabric (ft2). The ratio is therefore expressed
2-59
-------
2
as cfm/ft or sometimes also as filtering velocity (ft/min).
Most often only the first member of the ratio term is given,
2
e.g. an A/C ratio of 1.5 implies 1.5 (cfm)/1.0 (ft ). In
general, a lower ratio is used for filtering of gases con-
taining small particles or particles that may otherwise be
difficult to capture. Selection of the ratio is generally
based on industry practice or the recommendation of the
filter manufacturer. Design A/C ratios for the fabric
filters now installed in U.S. utility plants range from 1.9
to 2.8.
2.6.2 Pressure Drop
Pressure drop in a fabric filter is caused by the
combined resistances of the fabric and the accumulated dust
layer. The resistance of the fabric alone is affected by
the type of cloth and the weave; it varies directly with the
air flow. The permeability of various fabrics to clean air
is usually specified by the manufacturer as the air flow
2
rate (cfm) through 1 ft of fabric when the pressure dif-
ferential is 0.5 in. H»0 in accordance with the American
£
Society for Testing and Materials (ASTM). At normal filter-
ing velocities the resistance of the clean fabric is usually
less than 10 percent of the total resistance. The spaces
between the fibers are usually larger than the particles
that are collected. Thus the efficiency and low-pressure
drop of a new filter are initially low. After a coating of
2-60
-------
particles is formed on the surface, the collection effi-
ciency improves and the pressure drop also increases. Even
after the first cleaning and subsequent cleaning cycles,
collection efficiency remains high because the accumulated
dust is not entirely removed.
The pressure drop through the accumulated dust layer
has been found to be directly proportional to the thickness
of the layer. Resistance also increases with decreasing
14
particle size. Even though several studies have been
devoted to filtration theory, it is difficult to relate
collection efficiency and pressure drop on an industrial
scale. Maximum pressure drop on existing utility fabric
filters is 5 to 6 in. H2O.
2.6.3 Cleaning of Fabric Filters
Various cleaning methods are used to remove collected
dust from fabric filters to maintain a nominal pressure drop
of 2 to 6 in. HpO. Mechanical shaking or reversed air flow
are generally used to force the collected dust off the
cloth.
Many mechanical shaking methods are in use. High-
frequency agitation can be very effective, especially with
deposits of medium to large particles adhering rather loosely.
In such cases, high filtering velocities can be used and
higher pressure drops can be tolerated without danger of
blinding the cloth.
2-61
-------
In a relatively new cleaning method, an intermittent
pulse jet of high-pressure air (100 psi) is directed down-
ward into the bag to remove the collected dust. In some
designs the air is introduced at lower pressures, but these
systems may require a greater quantity of cleaning air.
Felted fabrics are used in conjunction with the pulse-jet
cleaning method. This type of cleaning, however has not yet
found use in the U.S. electric utility industry. A qualita-
tive comparison of cleaning methods is given in Table 2-127
In the fabric filter installation at the Nucla power
plant, the bags are cleaned by a combination of shaking and
reverse air flow. The normal cleaning cycle, shown in Table
2-13, is actuated by a pressure transducer near the inlet to
the induced-draft fan. The pressure switch is normally set
to initiate cleaning when the pressure drop across the bags
exceeds about 4 in. H-O. Once started, the cleaning cycle
proceeds through all six compartments, with a 17-second
interval between compartments. The pressure drop across the
baghouse is about 1.2 in. H20 lower after cleaning.
The repressure air (also reverse air or collapse air)
i
is supplied by a separate blower that constantly circulates
5600 cfm of flue gas from the outlet side of the baghouse.
When no compartment is undergoing repressure, the gas is
exhausted back into the duct leading to the induced-draft
2-62
-------
Table 2-12. COMPARISON OF FABRIC FILTER CLEANING METHODS
14
CJ
Cleaning
method
Shake
Rev. air
Plenum pulse
Pulse- jet
Vibrating,
rapping
Sonic assist
Uniformity
of
cleaning
Average
Good
Good
Average
Good
Average
Bag
attrition
Average
Low
Low
Average
Average
Low
Equipment
rugged ness
Average
Good
Good
Good
Low
Low
Type
fabric
Woven
Woven
Felt, woven
Felt, woven
Woven
Woven
Filter
velocity
Average
Average
High
High
Average
Aberage
Appa-
ratus
cost
Average
Average
High
High
Average
Average
Power
cost
Low
Med.
low
Med.
High
Med.
low
Med.
Dust
loading
Average
Good
High
V. high
Average
-------
Table 2-13. NORMAL CLEANING SEQUENCE FOR EACH COMPARTMENT
OF THE NUCLA BAGHOUSE 15
Event
Settle
Repressure
Settle
Shake
Settle
Repressure
Settle
Interval
Duration ,
Seconds
54
15
56
10
56
15
34
17
• : " -T— !—»-
Damper Positions
Main damper closed, repressure damper closed
Main damper closed, repressure damper open
Main damper closed, repressure damper closed
Main damper closed, repressure damper closed
Main damper closed, repressure damper closed
Main damper closed, repressure damper open
Main damper closed, repressure damper closed
Main damper open, repressure damper closed
Initiate next compartment cleaning
2-64
-------
fan. When repressuring is initiated, the main damper is
already closed and the repressure damper opens, allowing the
filtered flue gas to flow through the dirty bags in the
opposite direction to normal filtration at a velocity of
1.09 fpm. This gas then exits the compartment and joins the
dirty flue gas entering the remaining five compartments.15
Following the first reverse air flow and after about 1
minute of settling time the bags are shaken. The amplitude
is not known and is not divulged by the manufacturer; fre-
quency was measured at 4 cycles per second. The shaking
action appeared gentle and is most likely performed to
ensure loosening of the cake from the bag.
At the Sunbury plant the bags are cleaned by reversing
the gas flow through a compartment using a collapse air fan.
This partially collapses the bags and allows some of the
dust to be released and fall into the hopper below. Collapse
fan airflow is discharged into the baghouse inlet flue where
any entrained fly ash is filtered by the bags.
Each compartment is cleaned in the following manner:
1. The gas inlet damper to the compartment closes,
shutting off the flow of "dirty" flue gas to this
compartment.
2. The collapse damper opens, allowing a reverse flow
of "clean" flue gas from the outlet flue to be
pulled through the bags, partially collapsing and
thus cleaning the bags.
3. The collapse damper closes.
4. The gas inlet damper opens, returning the compart-
ment to the filtering mode.
2-65
-------
2.6.4 Frequency of Cleaning
So that no sizable portion of the total fabric will be
out of service for cleaning at any given time, the time
required for cleaning should be a small fraction of the time
required for dust deposition. With shake cleaning equip-
ment, for example, a common cleaning-to-deposition time
ratio is 0.1 or less. With a ratio of 0.1, 10 percent of
the compartments in the baghouse are out of
-------
Table 2-14. FABRIC FILTER CHARACTERISTICS"
14
to
I
Fiber
Cotton
Wool
Nylnnd
Orion
Dacron
Polypropylene
Nome*®15
Fiberglass
Teflo^J
Operating
Exposure.
°F
Long
180
200
200
240
275
200
425
550
450
Short
225
250
250
275
325
250
500
600
500
Sup-
ports
Combus-
tion
Yes
No
Yes
Yes
Yes
Yes
No
Yes
No
Air
Permea-
bility3,
cfm/ft2
10-20
20-60
15-30
20-45
10-60
7-30
25-54
10-70
15-65
Composition
Cellulose
Protein
Palyaiaide
Polys cry lonitr lie
Polyester
Olefin
Polyamlde
Glass
Polyfluoroethylene
Abra-
sion1"
C
G
E
G
E
E
E
P-F
F
Mineral
Acidsb
P
F
P
G
G
E
F
E
E
Organic
Acids.b
G
F
F
G
G
E
E
E
E
Alkaltb
G
P
G
F
G
E
G
P
E
Costc
Rank
1
7
2
3
4
6
3
5
9
cfm/£t* at 0.5 in. w.g.
a
b P = poor, F " fair, G • good, E » excellent.
c. Cost rank, 1 - lowest coat, 9 - highest cost.
d Du Pont registered trademark.
-------
A recent study conducted to determine the feasibility
of applying fabric filters on coal-fired industrial boilers
R R
involved four different filter media: Nomex felt, Teflon
R R
felt, Gore-Tex , and Dralon . Weights and permeabilities
are shown in Table 2-15. The study concluded that filtra-
tion with Nomex achieved the lowest outlet dust concentra-
tions and provided higher collection efficiencies than with
the other fabrics both with and without cleaning being done.
Teflon felt operated at the lowest pressure drop, and the
dust-release properties of Teflon felt and Gore-Tex appeared
better than those of Nomex and Dralon. However, it is
expected that the life of Nomex will be short because of
hydrolytic attack, unless the fabric is protected or treated
to resist attack. Thus far only fiberglass bags have been
used on the coal-fired utility boilers at Nucla, Sunbury,
and Holtwood.
2.6.6 Degree of Sectionalization
Design of the degree of sectionalization or the number
of separate filter compartments requires knowledge of the
variation in gas flow with respect to process or plant
ventilation, the sizes of commercially available units, and
the expected frequency of maintenance. Individual com-
partments in small collectors may contain as little as 100
2
ft of fabric surface; some large collectors with a capacity
of 50,000 cfm may contain only one compartment. Multiple
2-68
-------
Table 2-15. CHARACTERISTICS OF NOMEX, TEFLON,
GORE-TEX,® AND ORALON^16
Filter
Media
Weight,
oz/yd^
Permeability
cfm sq ft @ 1/2 in. H2O AP
Nomex Felt
Teflon® Feltb
Style 2663
(R)
Teflon^ Felt
Style 2063
Gore-Tex
Dralon-T^Felt
14
22-24
18-20
4-5 +
Laminate
13-15
25-35
15-35
25-65
8-15
20-30
a
b
c
d
High temperature resistant nylon fiber (polyamide).
Tetrafluoroethylene (TFC) Fluro-Carbon.
Expanded Teflon (polytetrafluroethylene) with interfacing
air filled pores.
Homopolymer of 100% acrylonitrile.
(n\
and Tef lorW — -
Registered trademarks:
(Ri
E.I. du Pont de Nempurs and Company; Dralonw — Farbenfabriekn
Bayer AG; Gore-Tex^ — W. L. Gore and Associates.
2-69
-------
compartments of any size may be selected, depending upon
availability. The largest size to date has a capacity of
4.5 x 10 acfm.
The Nucla and Sunbury Stations contain 6 and 14 com-
2
partments per baghouse, respectively, with 5161 ft and' 8262
ft per compartment, respectively.
In existing utility applications, at least one com-
partment will be out of service during the cleaning! cycle.
2.6.7 Filter Housing
Configuration of the filter housing depends on the
required fabric surface area and on the temperature, moist-
ure content, and corrosiveness of the gases. When the
baghouse is designed so that the dirty gas enters the inside
of the bags under positive pressure, housing may be needed
only for weather protection, or for emission measurements..
Both the Nucla and Sunbury baghouses are enclosed and in-
sulated to keep the temperature above the dew point. At
Sunbury, the baghouse enclosures, including the interior
partitions, are constructed of 14-gauge mild steel and are
of all welded construction. The 14-gauge partitions and
welded construction were decided upon to insure gastight
construction to permit safe entering of isolated compart-
ments for routine inspections and minor maintenance while
the baghouse is in service.
2-70
-------
The floor area required for a baghouse depends on the
filtering surface area and size of the bags. For example,
2 2
1750 ft of filtering area can be provided in about 80 ft
of floor area by using bags 6 inches in diameter and 10 feet
long. If 12-inch-diameter bags are used, they must be about
14 feet long to provide the same filtering area in the same
floor space, though 12-inch-diameter bags can easily be
obtained in length of 20 feet or more when there is adequate
head room. This configuration (12 in. x 20 ft) would pro-
2
vide a baghouse having about 2500 ft of filtering area in
2 17
the same floor space (80 ft ) . The length/diameter ratio
affects the stability of vertical bags, so care must be
taken to ensure that bags do not rub together during opera-
tion or cleaning. The length/diameter ratio ranges from 5
14
to 40, and the Nucla and Sunbury ratios are 33 and 30,
respectively.
Design consideration must be given to allow adequate
space below the filter bags for the collecting hopper. The
hoppers are commonly designed with 45-degree or 60-degree
sloping sides to provide adequate sliding. The dust col-
lected in the hopper can be removed by screw conveyors,
rotary valves, trip gates, air slides, and other methods.
The most common construction material for the housing
is steel; other materials, such as concrete and aluminum,
2-71
-------
are also used. Corrugated asbestos cement paneling is often
used for exterior roofing and siding, with interior walls
and partitions made of steel.
2.6.8 Gas Conditioning or Cooling
Frequently, gases to be cleaned are too hot to directly
undergo cleaning in a baghouse and they are therefore; cooled
before entering the filtration system. Gas cooling,, how-
ever, is not required for fabric filters used ofi coal-fired-
utility boilers, because most are equipped with air preheateors,
2.6.9 Tabulation of Design Factors
Values for some of the design factors discussed above
are presented in Table 2-16 for the three filtrastion, systems
currently operating in the electric utility industry.
Boiler and fuel characteristics for these installations are
shown in Table 2-17. The fabric used; at all three installa-
tions is made of fiberglass.. Note that the Teflon-coated
fiberglass used at Sunbury weighs les& than the fabric used
at Nucla, even with a lower permeability.
2.6.10 Costs for Fabric Filters
2.6.10.1 Capital Costs - Nucla- Station - An, engineering
analysis of the installation was performed by Ensor,, et
9
al. [1976] to (1) assemble xnformation on capital and,
operating costs, (2) determine reliability, and; (3:) identify
any major problems. Ensor used the records of Colorado Ute,,
Jelco, Inc. (constructor) and Steams-Rogers (engineer).
2-72
-------
I
-J
Table 2 16. DESIGN FACTORS FOR FABRIC FILTRATION SYSTEMS OPERATING
AT COAL-FIRED POWER PLANTS
Baghouse manufacturer
Baghouse capacity, .acfm.
Type of baghouse
Air-to-cloth ratio
Maximum pressure drop, in. H20
Bag fabric
Fabric weight
Fabric permeability
Cleaning method
Bag size
Total no. of bags
Total filter area
No. cf compartments 1
in baghouse ]
Hue la Plant
Whee labrator-Frye , Inc .
• a
86,240
Suction
(size 814, model 264,
Series 8)
2.79
6
Graphited
Fiberglass
10.5 oz/yd2
86.5 cfm/ft2
Shacking and reverse
air flow
8 in. diameter x 22 ft
length
672
30,964 ft2
6
Sunbury Plant
Western Precipitation
222,000
Suction
1.92
5
Teflon-coated
fiberglass
9.5 oz/yd2
75 cfm/ft2
Reverse air flow
12 in. diameter x
30 ft length
1,260
115,668 ft2
14
Holtwood Plant
Wheelabrator-Frye, Inc.
200,000-
Suction
2.42
N/A
Fiberglass
N/A
N/A
Shaking and. reverse
air flow
8 in. diameter
N/A
N/A
S/A
N/A: Not available.
a
3 Baghouses; each 86,240 acfm.
-------
Table 2-17. BOILER AND FUEL CHARACTERISTICS FOR UTILITY
PLANTS USING FABRIC FILTRATION SYSTEMS
Nucla Plant
Sunbury Plant
Holtwood Plant
Boiler Data;
No. of boilers
Firing method
Rated capacity, MM
Steam rate/boiler,
Ib/hr
Fuel Characteristics;
Coal type
3
Stoker
39 (total)
131,800 ....
Western coal
HV, 12,000 Btu/lb
0.5 - 0.7% sulfur
14-20% ash
45% fixed carbon
Pulverized
175 (total)
400,000 ir
N/A
Pulverized
N/A
700,000 .
ir
807. anthracite
silt and 207.
petroleum coke
normally used.
Minimum coke is
15% and maximum
coke is 357..
Rest is anthracite
silt
Goke:
3.7-5.97. sulfur
0.1-4.97. ash
81.8-90.77, fixed
carbon
Anthracite Silt;
0.4-1.27. sulfur
22.8-49.37. ash
44.5-65.57. fixed
carbon
Anthracite
fines
(NO other
data available)
2-74
-------
Since the Nucla plant was retrofitted with baghouses and
other additional equipment, some of the costs may be unique
to the Nucla site. Table 2-18 presents a summary of Ensor's
estimate. The unit costs of $87/kw or $12.97/acfm include
everything associated with the control devices. The costs
are escalated from 1973/1974 to 1976 at 10 percent per year.
Remote location, small size, lack of skilled labor at the
site all contributed to abnormally high cost.
Table 2-18. SUMMARY OF CAPITAL COST
NUCLA STATION BAGHOUSES9
Equipment and Installation
Baghouse and general
Ash conveyor system
Retrofit items
TOTAL FIELD COST3
Indirect Owner Costs
Engineering and Fee
1973/1974 INSTALLED
SYSTEM COST
Estimated Escalation to 1976
$1,740,000
250,000
210,000
$2,200,000
120,000
300,000
$2,620,000
680,000
%
67
9
8
84
5
11
100
25
1976 INSTALLED SYSTEM
COST
Unit Factors (1976)
$3,300,000
- $87/kw
- $13/acfm
- $36/ft2 filter
(gross)
a Includes material, labor, supervision, field overhead, and
constructor's fees.
2-75
-------
2.6.10.2 Capital Costs - Sunbury Station - For the Sunbury
baghouse system, the 1973 total cost was about $5.5 million,
including the ash slurry handling system. This cost is for
18
four baghouses, each having a capacity of 222,000 acfm.
Escalated to 1976 at 10 percent per year, the installed cost
is $42/kw or $8/acfm. If the baghouse cost alone is con-
sidered, the capital cost works out to be $25/kw or $5/acfm.
Unfortunately, the costs for Sunbury cannot be compared
directly with those for Nucla since the baghouses are made
by different manufacturers and have different capacities,
which might affect the cost per kw or acfnu It is reason-
able to conclude, however, that the 1976 installed capital
cost would range from about $42 to $87/kw ($8 to $13/acfm)
for a baghouse having a capacity in the range of 86,000 to
220,000 acfm. These values are based on the 1973 Nucla and
Sunbury costs of $29 and $65/kw ($6 and $10/acfm) and as-
sumption of an inflationary rate of 10 percent per year. A
detailed breakdown of installation costs for the Sunbury
18
system is shown in Table 2-19. Some of Sunbury's steam is
used other than in the two 87.5-MW turbines, so that $/kw
are slightly higher than would be expected.
Since selection of control devices cannot be made on
the basis of capital cost alone, and since complete data on
operation and maintenance costs of fabric filters on coal
2-76
-------
Table 2-19. SUNBURY STEAM ELECTRIC STATION BAG FILTER
INSTALLATION COST BREAKDOWN18
Expenditure Description
Western Precipitation contract
Four baghouses
Design and engineering - baghouse
Design and engineering - hopper enclosures
Vacuum cleaning system
Extra platforms, caged ladders, etc.
Supplements and contingencies
Western Precipitation contract
Land and land rights
Structures and improvements
Foundation - baghouse
Clearing site - ash lines
Clearing site - seal water lines
Clearing site - elec. conduit
Clearing site - storm drain & sewer In
Grading (crushed stones)
Pump house
Foundation
Superstructure
Drainage system
Light and power system
Heating system
Precipitator roof alterations
fihr-iiotiiYcs and imorovements
Material
cost, $
1,266,985
30 ,'415
95,105
37,800
2,000
6,600
40,000
6,500
16,500
3,700
17,500
Labor
cost , $
1,020,000
43,820
21,205
Subtotal
45,900
9,200
500
87,200
6,000
3,000
7,000
37,000
7,900
2,700
1,600
32,600
Subtotal
Total
cost, $
2,285,985
493,400
69,740
74,235
1,16,310.
161,030
3,201,700
1,500
83,700
9,200
500
87,200
6,900
5,000
13,600
77,000
14,400
19,200
5,300
50,100
372,100
2-77
-------
Table 2-19 (continued). SUNBURY STEAM ELECTRIC STATION
BAG FILTER INSTALLATION COST BREAKDOWN18
Expenditure Description
Boiler plant equipment
Afh removal system - bag filter
Piping and fittings
High-capacity intake and accessories
Electrical connections
Ash slurry systems
Piping, valves, and fittings
Slurry tank and accessories
Pumps & drives
Electrical connections
Raw water pump
Foundations
Pumps and drives
Piping, valves, and fittings
Electrical connections
Booster pumps
Foundation
Pumps & drives
Piping, valves, and fittings
Electrical connections
Mechanical hoppers -expansion
Multiclones in mesh collectors -replace
Piping for extended mech. hopper
Air piping, valves, and drives
Platforms and walkways
Boiler plant equipment
Material
cost, $
190,000
50,000
1,500
175,000
11,400
57,000
500
7,700
15,400
28,500
2,500
4,400
24,600
12,500
3,500
26,400
700
6,800
21,500
Labor
cost, $
135,000
37,000
1,000
113,400
4,600
26,300
400
7,000
7,000
16,700
900
10,500
7,900
15,000
1,500
59,400
51,000
3,900
10,500
40,900
Subtotal
Total
'cost, $
325,000
87,200
2,500
288,400
16,000
83,300
900
14,700
22,400
45,200
3,400
14,900
32,500
27,500
5,000
85,800
51,000
4,600
17,300
62,500
1,190,000
2-78
-------
Table 2-19 (continued). SUNBURY STEAM ELECTRIC STATION
BAG FILTER INSTALLATION COST BREAKDOWN18
Expenditure Description
Accessory electric equipment
Conduit
Power and control cable
Power cable
Control cable
Accessory electric equipment
Misc. power plant equipment
Communication
Public address system
Overheads
Engr. and supervision-indirect
Contract engineering .
Engr. and supervision-direct
Civil
Mechanical
Sta. electrical
Cost analysis and inspection
Allow, for funds used during constr.
Temporary construction power
Construction supervision
Removal cost
Salvage recovered
Overheads
Total construction costs (1973)
Escalation to 1976 9 10%/yr
1976 Installed system cost
Material
cost , $
4,000
7,900
23,500
200
Unit fac
Labor
cost , $
11,000
10,900
14,400
Subtotal
100
Subtotal
Total
cost, $
15,000
18,800
3 7 ,,900
71,700
300
109,400
15,000
75,000
85,800
37,000
64,500
240,000
6,000
10,000
23,100
3,000 Cr
662,800
5,500,100
1,821,000
7,321,000
tors (1976) - $42/kW
- $8/acfm
- $16/ft2
filters (gross)
1
2-79
-------
fired boilers are not available, no attempt is made here to
compare the costs of fabric filters with costs of precipita-
tors and scrubbers.
2.6.10-3 Maintenance and Operating Costs - Nucla Station -
9
Ensor, et al./ defined operating costs as any additional
costs incurred by the utility attributable to the operation
of the baghouse. The costs were estimated from Colorado Ute
records and estimated by the plant personnel. Table 2-20
summarizes the operating costs for 1976, which were esti-
mated at 1.53 mills/kwh based on a 55 percent capacity
factor (all direct and indirect costs).
After a review of plant maintenance records Ensor, et
al., found that the major maintenance item has been the
replacement of bags. Table 2-21 summarizes maintenance
records for the Nucla plant. The trend in labor maintenance
requirements are illustrated in Figure 2-12. During the
initial months of operation, it was discovered that severe
bag erosion at the inlet of the bags resulted in premature
bag failure. During a 6-month period starting in September
1974, gas straighteners, called "thimbles", were installed
at the inlet of the bags. The, thimbles resulted in a major
decline in maintenance.
During the first 2 years of operation, 18 percent of
the 2016 bags were replaced (32,577 baghouse hours of
2-80
-------
Table 2-20. NUCLA FABRIC FILTER SYSTEM
OPERATING COST ESTIMATE (1976)
Direct Costs
Operation labor '
Maintenenace labor
Maintenance material
Utilities
Ash handling
Subtotal ,
Direct
Interest Costs
Depreciation
Interest
Insurance
Taxes
Subtotal,
Indirect
TOTAL
$/year
(9,500)
2,500
8,500
31,000
11,000
53,000
127,000
81,000
3,000
23,000
234,000
287,000
%
(3.3)
0.9
3.0
10.8
3.8
18.5
44.3
28.2
1.0
8.0
81.5
100
mills/kwh (b)
(0.05)
0.01
0.05
0.16
0.06
0.28
0.68
0.43
0.02
0.12
1.25
1.53
Not added since no new costs were incurred.
Based on 188 million kwh/year or 55 percent capacity.
2-81
-------
Table 2-21. BAGHOUSE MAINTENANCE SUMMARY
a9
Maintenance
Category
Bag Replacement
Control System
Dampers and Actuators
Reverse Air Fans
Pressure Taps
Hopper Heaters
Miscellaneous
Subtotal
Routine
Total
Dec 1973
July 1974
106/24
67/15
19/6
40/7
2/1
1/1
12/4
247/58
6/2
253/60
Period
Aug 1974
Jan 1975
99/19
66/11
35/9
80/10
23/6
16/3
7/2
326/60
6/2
332/62
Feb 1975
July 1976
46/7
22/4
20/6
10/2
4/1
14/4
0/0
116/24
6/2
122/26
Aug 1975
Dec 1976
13/4
42/10
26/7
2/1
2/1
0/0
9/1
94/24
6/2
100/26
Total
264/54
197/40
100/28
132/20
31/9
31/8
28/7
783/166
24/8
807/174
to
00
N)
Units: man hours/occurrences
The four periods have the same amount of baghouse operating time.
-------
50
00
U)
40
Q_
o
CO
on
o
n:
i
LLJ
CO
O
CD
3
o
o
o
LU
O.
CO
OS
O
-l
30
20
10-
I T
AVERAGE OF
PREVIOUS
3 MONTHS
INSTALLATION OF
•« THIMBLES
j I
AVERAGE OF
PREVIOUS
\ 12 MONTHS
1 I
.DJ FMAMJJASONDJ FMAMJJASQN
1974 _ 1975
\
Figure 2-12. Maintenance labor requirements for the Nucla baghouse.
-------
operation). Most of the bags were replaced before thimble
installation.
The following equipment requires regular maintenance:
0 the control system
0 dampers and actuators
0 reverse air for drives
0 plugged pressure taps
o
o
hopper heating system
freezing of compressed air lines
Ensor, et al., analyzed the reliability of the baghouse
from various points of view. The various estimates of
reliability are summarized in Table 2-22.
Table 2-22. RELIABILITY OF UNIT
Reliability Type
Noninterference with boiler operation
Ability to produce clear stack opacity
Compartment reliability
Precent of Time
100.0
99.4
99.8
2.6.10.4 Maintenance and Operating Costs - Sunbury Baghouse -
Yearly operating and maintenance costs as estimated by the
18
Sunbury plant superintendent are given in Table 2-23.
These costs, excluding complete baghouse bag replacement
material and labor costs, for the four baghouses for 1973
and 1974 were $0.037 and $0.036/acfm, respectively, based
18
on the design flow rate of 222,000 acfm per baghouse.
Table 2-23 indicates that mechanical maintenance costs have
been increasing while electrical maintenance costs have been
decreasing. This is believed to reflect some electrical
problems during and after start-up and wearing of the collapse
air fans with age.
2-84
-------
to
1
00
Table 2-23. ESTIMATED OPERATING AND MAINTENANCE COSTS OF THE
SUNBURY STEAM ELECTRIC STATION BAGHOUSE
Cost
Description
Collapse fans power consumption
Air compressor power consumption
Complete bag replacement
Boiler 1A
material
labor
Boiler 2A
material
labor
Boiler 2B
material
labor
Instrument department labor
Mechanical maintenance labor
Electrical maintenance labor
Construction department labor
Total costs
1973
Cost , $
18,600
Insignificant
950
2,130
7,410
3.950
33,040
1974
Cost , $
18,600
Insignificant
48,000
11,000
950
5,840
3,800
2.350
90,540
First 6 Months
1975
Cost , $
9,300
Insignificant
48,000
11,000
48,000
11,000
450
6,270
2,910
: —
136,930
Cost Incurred
Through
June 1975, $
46,500
Insignificant
43,000
11,000
48,000
11,000
48,000
11,000
2,350
14,240
14,120
6.300
260,510
-------
REFERENCES - SECTIONS 1.0 and 2.0
1. Symposium on Electrostatic Precipitators for the Con-
trol of Fine Particles. EPA-650/2-75-016. pp. 5-12.
2. Sondreal, E.A., and P.H. Tufte. Scrubber Developments
in the West. U.S. ERDA, Grand Forks Energy Research
Center. Grand Forks, North Dakota. 1975.
3. Peters, M.S., and K.D. Timmerhaus. Plant Design and
Economics for Chemical Engineers. McGraw-Hill, New
York. 1968. pp. 252-254.
4. Matts, S., and P.O. Ohnfeldt. Efficient Gas Cleaning
with SF Electrostatic Precipitators.
5. Greco, J. and J.A. Hudson. "Specifications for High
Efficiency Electrostatic Precipitators for Coal Fired
Steam-Electric Generating Plants" in Air Pollution
Control and Industrial Energy Production.EdTtecT~by
Kenneth E. Noll, Wayne T.Davis,and Joseph R. Duncan,
Ann Arbor Science, Ann Arbor, Michigan. 1975.
6. Marchello, J.M., and J.J. Kelly. Gas Cleaning for Air
Quality Control. Marcel Dekker. New York. 1975.
7. Frisch, N.W., and D.W. Coy. Specifying Electrostatic
Precipitators for High Reliability. Proceedings of
Symposium on Electrostatic Precipitators for the Con-
trol of Fine Particles, Pensacola, Florida. September
30 - October 2, 1974. EPA-650/2-75-016. p. 149.
8. Personal communication with Dr. Grady B. Nichols.
Southern Research Institute. February 1976.
9. Symposium on Particulate Control in Energy Processes.
EPA-600/7-76-010. September 1976.
10. Research Cottrell, Flooded Disc Scrubber, Montana-
Dakota Utility - Lewis and Clark Station, Unit No. 1.
June 1976.
11. The Mcllvaine Scrubber Manual, Volume I. The Mcllvaine
Co. 1974.
2-86
-------
12. Wet Scrubber System Study, Volume I, Scrubber Handbook.
APT, Inc. PB213-016. July 1972.
13. Ensor, et al. Evaluation of a Particulate Scrubber on
a Coal Fired Utility Boiler. Meteorology Research,
Inc. EPA-600/2-75-074. November 1975.
14. Gorman, P.G., A.E. Vandegrift, and L.J. Shannon.
Fabric Filters in Gas Cleaning for Air Quality Control.
Marchello, J.M., and J.J. Kelly (eds.). Marcel Dekker,
Inc. New York. 1975.
15. Bradway, R.W., and R.W. Cass. Fractional Efficiency of
a Utility Boiler Baghouse, Nucla Generating Plant. NTIS
Document No. PB 245541. August 1975.
16. McKenna, J.D., J.C. Mycock, and W.O. Lipscomb. Apply-
ing Fabric Filtration to Coal-Firing Industrial Boilers
A Pilot Scale Investigation. EPA Report No. EPA-650/
2-74-048-a. August 1975.
17. Billings, C.E., and J. Wilder. Handbook of Fabric
Filter Technology, Volume 1. Prepared by GCA Corpora-
tion for National Air Pollution Control Administration,
Contract No. CPA-22-69-38. December 1970.
18. Cass, R.W., and R.M. Bradway. Fractional Efficiency of
a Utility Boiler Baghouse—Sunbury Steam Electric
Stations. EPA Report No. EPA-600/2-76-077a. March
1976.
2-87
-------
3.0 OPERATION AND MAINTENANCE OF PARTICULATE
CONTROL DEVICES ON COAL-FIRED BOILERS
As with other complex equipment, the successful func-
tioning of pollution control systems depends not only on
sound design and proper installation, but also on proper
operation. Plant personnel who use and maintain the equip-
ment ideally will understand the engineering principles on
which the system is based and will apply this knowledge both
in routine operation/maintenance and in emergency situations.
3.1 OPERATION AND MAINTENANCE OF ELECTROSTATIC PRECIPITATORS
Problems with electrostatic precipitators can arise
when the precipitator is brought on line and also after
extended operation. Since the possible causes of poor
precipitator performance are diverse, it is impractical to
outline a single procedure for determining the nature of a
specific problem. When a malfunction occurs, the operator
must depend on his theoretical understanding of the equip-
ment, backed by his practical experience. This section,
therefore, provides background information on precipitator
operation, together with detailed maintenance and trouble-
shooting procedures for the major component categories.
3-1
-------
Since the basic precipitator functions are those of charging
and collection of particles, the components and controls
associated with the transformer-rectifier sets, rappers, and
vibrators constitute the heart of the system.
The procedures presented here are those suggested by
Research Cottrell, Inc. Although other manufacturers might
recommend different procedures as dictated by details of
system design, most of the major components, and therefore
the operating procedures, are similar. Where it is possi-
ble, the recommended practices are interpreted in terms of
their effects on equipment performance.
3.1.1 Background on Precipitator Operation
Electrostatic precipitation requires two groups of
equipment: (1) the precipitation chamber, in which the
suspended particles are electrified and removed from the
gas, and (2) the high-voltage transformer and rectifier,
which function to create the strong electrical field in the
chamber.
The chamber consists of an outside shell (precipitator
shell) made of metal, tile, or other material. Suspended
within the shell are grounded steel plates (collecting
electrodes) connected to the grounded steel framework of the
supporting structure and to an earth-driven ground. Sus-
pended between the plates are metal rods or wires (discharge
3-2
-------
electrodes) insulated from ground, which are negatively
charged at voltages ranging from 70,000 to 105,000 volts.
The great difference in voltage of the wires and the collec-
ting plates sets up a powerful electrical field between
them, which imparts a negative charge to the solid particles
suspended in the gas stream. Understanding of this phenom-
enon requires some knowledge of electricity and chemistry;
for practical purposes it is enough to know that the parti-
cles become electrically charged. The negatively charged
particles are attracted to the collecting plates, which are
at ground potential. The particles cling to the collecting
plate and become electrically inert. Removal of the collec-
ted dust is best achieved by rapping the plates at an in-
tensity and frequency that causes the dust to fall from the
plates in sheets into a receiving hopper. Rapping that is
too intense or too frequent will clean the collection plate
but may also cause reentrainment of the collected dust into
the gas stream.
The gas that entered the precipitator laden with
particles is channeled through the precipitator outlet,
while the dust collected in the hopper is removed via an ash
handling system.
Figure 3-1 illustrates the major components of a fly
ash precipitator with top housing (as opposed to insulator
compartments, which are used in both hot- and cold-side
3-3
-------
TRANSFORMER-RECTIFIER
GROUND SWITCH BOX
ON TRANSFORMER
DISCHARGE ELECTRODE VIBRATOP
TOP END FRAMES
HIGH VOLTAGE
CONDUCTOR
HIGH TENSION
SUPPORT INSULATORS
PERFORATED
DISTRIBUTION
PLATES
BOTTOM END FRAMES
UPPER H.T. HANGER ASSEMBLY
(HANGER AND HANGER FRAME)
UPPER H.T. WIRE
SUPPORT FRAME
COLLECTING ELECTRODE
M.I.G.I RAPPERS
TOP HOUSING
HOT ROOF
ACCESS DOOR
HOT ROOF
SIDE FRAMES
DISCHARGE
ELECTRODE,
ACCESS DOOR
BETWEEN
COLLECTING PLATE
SECTIONS
PRECIPITATE
BASE PLATE
SLIDE PLATE
PACKAGE
SUPPORT STRUCTURE
CAP PLATE
HOPPER
HORIZONTAL BRACING STRUT
STEADYING BARS
LOWER H.T.
STEADYING FRAME
COLLECTING ELECTRODES
Figure 3-1. Typical electrostatic precipitator with top housing.
3-4
-------
applications. In recent years, however, top housings have
not been used in hot-side applications because of expansion
problems. The remainder of this section describes the major
precipitator components.
3.1.1.1 Transformer-Rectifiers - The transformer-rectifier
unit consists of a high-voltage transformer, high-voltage
silicon rectifiers, and high-frequency choke coils. The
unit converts the low-voltage alternating current to high-
voltage unidirectional current suitable for energizing the
precipitator.
The transformer, rectifiers, and choke coils are sub-
merged in a tank filled with a dielectric fluid. The tank
is equipped with high-voltage bushings, liquid level gauge,
drain valve, ground lug, filling plug, lifting lugs, and
surge arresters, which discharge any harmful transients
appearing across the dc metering circuit to ground.
The electrical equipment described below comprises the
components necessary to produce and control the high-voltage
unidirectional power required to energize the electrostatic
precipitator. The transformer-rectifier and control unit
provide a complete system for energizing with either half-
wave or full-wave voltages. Not all precipitator installa-
tions incorporate all of these subcircuits, but most will
include many of the features; some of the automatic features
described here may be done manually on some installations.
3-5
-------
A subsystem that automatically maintains and limits
optimum current and voltage to the high-voltage trans-
former, which is connected to the discharge wires.
Silicon controlled rectifiers (SCR's), which provide a
wide range of precipitator current and voltage control.
A current-limiting reactor, which limits current surges
during precipitator sparking.
Automatic restart to initiate system operation after a
line voltage failure or temporary ground condition in
the precipitator.
Overload protection for the high-voltage rectifiers.
Panels containing component modules; the SCR power
circuit, dc overload circuits, relays, control transformers,
resistors, main contactor, and current transformer and other
components are mounted in the control cabinet and are com-
pletely accessible for servicing. Positive ventilation for
the control unit is provided by an intake fan located near
floor level. Ventilating air is exhausted through an open-
ing (grill-protected) in the upper rear of the control unit.
The transformer enclosure is a square metal housing
bolted to the top of the transformer tank. The enclosure
protects the transformer bushings and electrical connections
from weather and also ensures, via a key interlock system,
that none of the electrical connections or bushings can be
handled until the associated control cabinet has been de-
energized and grounded.
j
The transformer pipe and guard are used to feed the
high-voltage output of the transformer-rectifier to the
3-6
-------
support bushings, which in turn are connected to the upper
high-tension support frame, from which the discharge wires
are suspended. Figures 3-2 and 3-3 illustrate rapper and
insulator assemblies and their relationship to the ESP
system.
During normal operation, optimization of applied power
to the precipitator is accomplished by automatic power
controls, which vary the input voltage in response to a
signal generated by the sparkover rate. Provisions are also
included to make the circuit current sensitive to overload
and to allow control in the event that spark level cannot be
reached. Although the circuits may vary among installa-
tions, many of the features described below are common.
When the circuit breaker and control circuit on/off
switch are closed, power flows through the current-limiting
reactor, current transformer, and current signal transformer
to the primary of the high-voltage transformer. The SCR's
act as a variable impedance and control the flow of power in
the circuit. An SCR is a three-junction semiconductor
device that is normally an open circuit until an appropriate
gate signal is applied to the gate terminal, at which time
it rapidly switches to the conducting state. Its operation
is equivalent to that of a thyroton. The amount of current
that flows is controlled by the forward blocking ability of
the SCR's. This blocking ability is controlled by the
3-7
-------
DISCHARGE
ELECTRODE
VIBRATOR
DISCHARGE
ELECTRODE
VIBRATOR
DISCHARGE ELECTRODE VIBRATOR
AND INSULATOR ASSEMBLY
COLLECTING
ELECTRODE
RAPPER
RAPPER
COUPLING
COLLECTING ELECTRODE RAPPER
Figure 3-2. Vibrator and rapper assembly, and
precipitator high-voltage frame.
3-8
-------
VIBRATOR OR
RAPPER
POWER CABLE
STUFFING BOX
SEAL PLATE
ASBESTOS PAD
INSTALLATION
ACCESS DOOR
LOCATED TO SUIT
BRACKET
UPPER RAPPER ROD
INSULATOR COMPARTMENT
VENTILIATING OR PRESSURIZING
AIR CONNECTION, LOCATED TO SUIT
INSULATOR SHAFT
ASBESTOS PAD
INSTALLATION
HIGH TENSION
DUCT CONNECTION
LOCATED TO SUIT
LOWER RAPPER ROD
SUPPORT BUSHING
PRECIPITATOR ROOF
Figure 3-3. Typical precipitator insulator compartment and
cleaning assembly..
3-9
-------
firing pulse to the gate of the SCR. The current-limiting
reactor reshapes the current wave form and limits peak
current due to sparking.
The firing circuit module provides the .proper phase-
controlled signal to fire the SCR. The timing of the signal
is controlled by (1) the potentiometer built in the module,
(2) the signal received by the automatic controller, and (3)
the signal received by the spark stabilizer.
The automatic control circuit performs three functions:
spark control, current-limit control, and voltage-limit
control.
Spark control is based on storing electrical pulses in
a capacitor for each spark occurring in the precipitator.
If the voltage of the capacitor exceeds the present refer-
ence, an error signal will phase the mainline SCR's back to
a point where the sparking will stop. Usually this snap-
action type of control will tend to overcorrect, resulting
in a longer downtime than is desirable. At low sparking
rates, about 50 sparks per minute, the overcorrection is
more pronounced, resulting in reduced voltage for a longer
period, with subsequent loss of dust and reduced efficiency.
Proportional control, another method of spark control,
is also based on storing of electrical pulses for each spark
occurring in the precipitator. The phaseback of the main-
line SCR's, however, is proportional to the number of sparks
3-10
-------
in the precipitator. The main advantage of proportional
control over spark control is that the precipitator deter-
mines its own optimum spark rate, based on four factors:
temperature of the gas, ash resistivity, dust concentration,
and internal condition of the precipitator. In summary,
with proportional spark rate control, the precipitator
determines the optimum operating parameters. With conven-
tional spark control, the operator selects the operating
parameters, which may not be correct.
Some precipitators operate at the maximum voltage or
current settings on the power supply with no sparking. In
collection of low-resistivity dusts, where the electric
field and the ash deposit are insufficient to initiate
sparking, the no-spark condition may arise. The fact that
the precipitator is not sparking does not mean necessarily
that the unit is underpowered. The unit may have sufficient
power to provide charging and electric fields without spark-
ing.
The voltage-limit control feature of the automatic
control module limits the primary voltage of the high-
voltage transformer to its rating. A transformer across the
primary supplies a voltage signal that is compared to the
setting of the voltage control, as in the case of the cur-
rent limit. The voltage control setting is adjusted for the
primary voltage rating of the high-voltage transformer.
3-11
-------
When the primary voltage exceeds this value, a signal is
generated that retards the firing pulse of the firing module
and brings the primary voltage back to the control setting.
For current-limit control, a transformer in the primary
circuit of the high-voltage transformer monitors the primary
current. The voltage from this transformer is compared with
the setting of the current control, which is adjusted to the
rating of the transformer-rectifier unit. If the primary
current exceeds the unit's rating, a signal is generated, as
with spark control, which retards the firing pulse of the
firing circuit and this brings the current back to the
current-limit setting.
With all three control functions properly adjusted, the
control unit will energize the precipitator at its optimum
or maximum level at all times. This level will be deter-
mined by conditions within the precipitator and will result
in any one of the three automatic control functions operat-
ing at its maximum, i.e., maximum voltage, maximum primary
current, or maximum spark rate. Once one of the three
maximum conditions is reached, the automatic control will
prevent any increase in power to reach a second maximum. If
changes within the precipitator so require, the automatic
control will switch from one maximum limit to another.
Other features include secondary overload circuits and
an undervoltage trip capability in the event that the volt-
3-12
-------
age on the primary of the high-voltage transformer falls
below a predetermined level and remains below that level for
a period of time. A time-delay relay is also used to pro-
vide a delay period in the annunciator circuit while the
network of contacts is changing position for circuit stabi-
lization due to an undervoltage condition.
An SCR mainline control diagram (Figure 3-4) illus-
trates operation of the system described above.
3.1.1.2 Rappers - The rapper equipment is a completely
electrically operated system for continuously removing dust
from the collecting plates within the precipitator. The
system is composed of a number of magnetic-impulse, gravity-
impact rappers that are periodically energized to rap the
collecting plates for removal of dust deposits. The main
components of the system are the rappers and the electrical
controls.
The magnetic-impulse, gravity-impact rapper is a sole-
noid electromagnet consisting of a steel plunger surrounded
by a concentric coil, both enclosed in a watertight steel
case. The control unit contains all the components (except
the rapper) needed to distribute and control the power to
the rappers for optimum precipitation. The electrical
controls provide a number of separate adjustments so that
all rappers can be assembled into a number of different
groups, each of which can be independently adjusted from
zero to maximum rapping intensity.
3-13
-------
OJ
I
SCR
CURRENT
LIMITING
REACTOR
PHASE
CONTROL
H.V.
TRANS.
H.V.
RECTIFIER
FULL WAVE JUMPER-
SPARK
RATE
CURRENT, VOLTAGE
AND SPARK RATE CONTROL
STAB.
POWER
430-480V.
60 HZ
UNDER
VOLTAGE
ALARM
-WIRES-
V /
XPLATES
SECONDARY
OVERLOADS
CONTROL
CONTACT-
PRECIP
MA
CURRENT
METER
Figure 3-4. SCR mainline control,
-------
During normal operation, a short-duration, dc pulse
through the coil of the rapper supplies the energy to move
the steel plunger. The plunger is raised by the magnetic
field of the coil and then is allowed to fall back and
strike a rapper bar, which is connected to a bank of collec-
ting electrodes within the precipitator. The shock trans-
mitted to the collecting electrodes dislodges the accu-
mulated dust.
The electrical controls provide a number of separate
adjustments so that rappers can be assembled into a number
of different groups and each group independently adjusted
according to transmissometer readings. The controls are
adjusted manually to provide adequate release of dust from
collecting plates while preventing undesirable stack puf-
fing.
In some applications, the magnetic impulse, gravity
impact rapper is also used to clean the precipitator dis-
charge wires. In this case the blow is imparted to the
electrode supporting frame in the same manner, except that
an insulator isolates the rapper from the high voltage of
the electrode supporting frame.
Some installations have mechanical rappers. In these
installations each frame is rapped by one hammer assembly
3-15
-------
mounted on a shaft. A low-speed gear motor is linked to the
hammer shaft by a drive insulator, fork, and linkage assembly,
Rapping intensity is governed by the hammer weight, and rap-
ping frequency is governed by the speed of rotation of the
shaft.
3.1.1.3 Vibrators - The purpose of a vibrating system is to
create vibrations in either the collecting plates or the
discharge wires to dislodge accumulations of particles so
that the plates or wires are kept in optimum operating
condition. For collection of fly ash, vibrators are not
normally used to clean the collecting electrodes.
The vibrator is an electromagnetic device, the coil of
which is energized by alternating current. Each time the
coil is energized, the vibration set up is transmitted to
the high-tension wire supporting frame and/or collecting
plates through a rod. The number of vibrators depends on
the number of high-tension frames and/or collecting plates
in the system.
The control unit contains all devices for operation of
the vibrators, including means of adjusting the intensity of
vibration and the vibration period. Alternating current is
supplied to the discharge wire vibrators through a multiple
3-16
-------
cam-type timer to provide the sequencing and time cycle for
energization of the vibrators.
For each installation, a certain intensity and time
period of vibration will produce the best collecting effi-
ciency. Insufficient intensity of vibrating will result in
heavy buildups of dust on the discharge wires, which can
cause the following adverse operating conditions:
It reduces the spark-over distance between the elec-
trodes, thereby limiting the power input to the pre-
cipitator.
It tends to suppress the formation of negative corona
and the production of unipolar ions required for the
precipitator process.
It alters the normal distribution of electrostatic
forces in the treatment zone. Unbalanced electrostatic
fields can cause the discharge wires and the high-
tension frame to oscillate.
Upper Precipitator
On all positive and on some negative pressure installa-
tions a pressurizing fan is supplied (located on the cold
roof) to force air into the top housing and down through the
support bushings. This air prevents the process gases in
the precipitator from entering the top housing and contami-
nating the support and high-tension frame rapper (vibrator)
insulators. Electric heaters are also used to warm the
inflowing air.
In place of a top housing, some installations have
insulator compartments. The insulator compartment is a
3-17
-------
steel enclosure that surrounds the high-tension frame sup-
port insulators and rapper rod insulators. Fans are pro-
vided to prevent condensation of moisture on the high-
voltage support insulator, and sometimes electric heaters
are installed near each bushing in each insulator compart-
ment.
The purpose of the high-tension anvil beam, which is
part of the high-tension frame, is to transfer the impact of
the high-tension vibrator to the discharge wires.
Discharge Wires
The discharge electrodes are small-diameter wires
suspended from a structural steel wire supporting frame,
held taut by individual cast iron weights at the lower end
and stabilized by a steadying frame at the top of the cast
iron weights. Unshrouded and shrouded discharge wires are
illustrated in Figures 3-5 and 3-6, respectively.
Collecting Plates
The gas flows horizontally in the precipitator through
individual gas ducts formed by the collecting plates. The
discharge wires are located midway between the plates for
the purpose of ionizing the gases and imparting an electric
charge to the dust particles. It is important that the
plate and wire spacing be held to close tolerances.. Figure
3-7 illustrates the type of collection plate used in most
ESP's manufactured by Research Cottre.ll.
3-l<8
-------
< ' J Shroud Cap
-Shroud
Vir.
- Sh'oud
I i
L.-..J
/ \
Figure 3-5. Discharge
electrode unshrouded.
— Cast
Iron
Weight
Figure 3-7. Precipitator
collecting electrodes.
Figure 3-6. Discharge
electrode shrouded.
3-19
-------
Lower Precipitator
The lower steadying frame limits or restricts the
horizontal movement of the discharge wires.
The foregoing discussion summarizes the design and
operation of the major precipitator components. The follow-
ing section outlines inspection and maintenance procedures
that will promote reliable functioning of the total precipi-
tator system.
3.1.2 Precipitator start-Up and Shutdown Procedures
Operation of an electrostatic precipitator involves
high voltage, which is dangerous to life; although all
practical safety measures are incorporated into the equip-
ment, extreme caution should be exercised at all times. An
electrostatic precipitator is, in effect, a large capacitor
which, when de-energized, can retain dangerous electric
charges. Therefore, grounding mechanisms provided at each
access point should be used before entering the precipitator.
3.1.2.1 Preoperational Checklist - Before placing the
equipment in operation, plant personnel should perform a
thorough check and visually inspect the system components in
accordance with recommendations of the manufacturer. A
complete checklist of items is presented in Appendix C.
Some of the major items that should be checked are sum-
marized below:
3-20
-------
Control unit
Proper connections to control
Silicon rectifier unit
Rectifier-transformer insulating liquid level
Rectifier ground switch operation
Rectifier high-voltage connections made
High-voltage bus transfer switch operation
High-tension connections
High-tension bus duct
Proper installation
Vent ports properly installed
Equipment grounding
Precipitator grounded
Transformer grounded
Rectifier controls grounded
High-tension guard grounded
Conduits grounded
Rapper and vibrator ground jumpers in place
3.1.2.2 Air Load Tests - After the precipitator is inspec-
ted (i.e., preoperational check adjustment of the rectifier
control, and check of safety features) the air load test is
performed. Air load is defined as energization of the
precipitator with minimum flow of air (stack draft) through
the precipitator. Before introduction of an air load or gas
load (i.e. entrance of dust-laden gas into the precipita-
tor) , the following components should be energized:
Collecting plate rappers
Perforated distribution plate rappers
High-tension discharge electrode vibrators
Bushing heaters - housing/compartments
Hopper heaters - vibrators - level indicators
Transformer rectifier
Rectifier control units
Ventilation and forced-draft fans
Ash conveying system
3-21
-------
The purpose of the air load test is to establish ref-
erence readings for future operations, to check operation of
electrical equipment, and to detect any improper wire clear-
ances or grounds not detected during preparation inspection.
Air load data are taken with the internal metal surfaces
clean. The data consist of current-voltage characteristics
at intervals of roughly 10 percent of the T-R milliamp
rating, gas flow rate, gas temperature, and relative humidity.
For an air load test the precipitator is energized on
manual control. The electrical characteristics of a pre-
cipitator are such that no sparking should occur. If spark-
ing does occur, an internal inspection must be made to
determine the cause. Usually, the cause is (1) close elec-
trical clearances and/or (2) the presence of foreign matter,
such as baling wire, that has been left inside the precipi-
tator.
After the precipitator has been in operation for some
time, it may be necessary to shut it down to perform inter-
nal inspections. At such times it would be of interest to
take air load data for comparison with the original readings.
3.1.2.3 Gas Load Tests - The operation of a precipitator on
gas load differs considerably from operation on air load
with respect to voltage and current relationships. The
condition of high current and low voltage characterizes the
air load, whereas low current and high voltage characterize
3-22
-------
the gas load. This effect governs operation of the precipi-
tator and the final setting of the electrical equipment.
In general, optimum precipitator efficiencies are
obtained when the dc voltage applied to the precipitator is
just at the threshold of sparking. The spark rate at this
point will be on the order of 50 to 150 sparks per minute
and may be controlled at this level with automatic control.
3.1.2.4 Shutdown Procedure - To shut down the precipitator,
the operator opens the control circuit start/stop switch and
then opens the main circuit breaker. Before entering the
system, the operator should follow all safety procedures.
Proper grounding of all precipitator parts is important.
The key interlock system prevents access to the interior of
each transformer-rectifier ground switch enclosure until the
individual set is de-energized and the ground connections
are made. This system prevents access to the interior of
the precipitator, including top housing or insulator com-
partments, precipitator roof doors, side doors, and hopper
doors, until the transformer-rectifiers of each precipitator
are de-energized and ground connections are made. Purging
the system with ambient air may also be desirable from the
standpoint of plant personnel who must inspect the internal
parts of the precipitator.
3-23
-------
3.1.3 Inspection and Maintenance During Normal Operation
Following are detailed directions for plant personnel
who are assigned responsibility for inspection and main-
tenance of the precipitator system. Although electrical
portions of the system require very little maintenance, the
items enumerated should be attended regularly if the equip-
ment is to give optimum service. It is good practice to
assign to one operator on each shift the task of checking
and recording data on electrical equipment at the start of
the shift.
3.1.3.1 Transformer-Rectifier Sets and Associated Equipment
and Controls - Check the liquid level in the transformer
weekly. If it is low, fill the tank to the level indicated
on the gauge with the dielectric liquid specified on the
nameplate. Dielectric fluid should be handled with extreme
caution.
Clean high-tension insulators, bushings, and terminals
during each outage to minimize surface leakage. Glazed
porcelain is best cleaned with a damp cloth and a non-
abrasive cleaner.
Once each year or more often, clean the contacts of
relays and dress them with a fine grade of crocus
cloth.
Check the dustop filter weekly. The air filter as-
sembly, easily attached and convenient for servicing,
is mounted on the control cabinet.
Transformer Enclosure
Inspect all bushings and insulators. Replace those
that are damaged; clean those that are dusty with a
nonabrasive cleaner.
3-24
-------
Clean all interlocks and lubricate with powdered graph-
ite to ensure smooth and proper action.
Lubricate all bearing points on the ground-operated
lever, connecting rods, and bevel gears.
Check all electrical connections to ensure that they
are corrosion-free and tight. Loose electrical connec-
tions can cause electrical erosion of connections and
failure of metering circuits and electrical components
in both the control cabinet and transformer.
Overhead HW-FW Switchgear
Inspect all insulators for cracks, chips, and/or duct
buildup. Replace all damaged insulators and remove
dust accumulations with a nonabrasive cleaner.
Inspect all visible contacts to be sure that they are
free of corrosion and pitting due to electrical arcing.
Handcleaning, filing, and/or wire-wheel cleaning may be
required.
Inspect for a tight fit on all couplings associated
with transformer output bushings and switching insula-
tors.
Lubricate mechanical bearing surfaces under the switch-
ing insulators to ensure smooth and proper operation.
Pipe and Guard
Remove all internal rust and/or scaling. Rust appear-
ing on the internal walls of the guard could peel off
and fall against the pipe, causing a ground on the
secondary of the transformer.
Check the condition of the wall and post insulators for
signs of electrical tracking (arcing), dust buildup,
and cracked insulators. Clean or replace parts as
required.
Check the pipe to ensure that all connections to wall
bushings and post insulators are tight and that the
pipe elbows used to redirect the pipe at various turns
in the guard are tight and secure.
Ensure against water leakage by checking and main-
taining the seal on the inspection plates of the pipe
and guard.
3-25
-------
When replacing the inspection covers, be certain to
reinstall the ground jumper between the guard and cover
plate; this ensures that any static charge or high-
voltage leak goes to ground.
3.1.3.2 Plate Rappers
Cold Precipitator
Check the rapper assemblies periodically for any pos-
sible binding of the plunger or misalignment of assem-
bly. The maximum amount of energy can be transmitted
from coil to plunger only when the plunger is properly
located with respect to the coil. Any deviation will
decrease the energy transmitted. Adjusting bolts allow
changes of the distance between the lower casing and
the mounting and thereby allow variation of the plunger
insertion in the coil.
If boot seal or service sheet gasket has deteriorated,
dismantle the rapper assembly and inspect the rapper
rod sleeve for ash accumulation. Packed ash in this
area will dampen shock wave to the collecting plate and
cause excessive ash accumulation on the plates (wires).
[A boot seal is the rubber seal that is stretch-fitted
over the end of the rapper rod. On negative-pressure
installations, the boot seal prevents air and water
from entering the precipitator chamber through the
rapper rod guide sleeve. On positive-pressure instal-
lations, the boot seal prevents precipitator gases from
flowing up the rapper and guide sleeve and entering the
rapper coil tube.]
Inspect striking end of plunger to insure that the end
has not been flared or otherwise deformed due to exces-
sive height in its lift and/or misalignment.
'*,
When reassembling the rapper assembly after maintenance
has been performed, make certain that the coil and coil
cover are plumb and level, and that the plunger is
properly aligned in a vertical plane on the rapper rod.
The maintenance checks outlined above apply also to
wire rappers.
3-26
-------
Hot Precipitator
As with cold precipitators, inspect each rapper to
ensure that it is operational and that the rapper
plunger is lifting at its prescribed height. If a
rapper is not operational, check the coil for electri-
cal continuity and grounds. If the problem is not in
the coil, check the field wiring and the rapper control
cabinet for malfunctions.
As with cold precipitators, with the rappers de-ener-
gized, check the plungers to see that they slide easily
into the coil tubes. If a plunger does not move
smoothly, dismantle the coil cover and inspect the coil
tube for accumulations of debris or ash.
Check the area where the rapper rod passes through the
packing ring retainer plate for signs of ash. If the
retainer plate is loose, retighten, being careful that
the plate is tightened equally on all sides and that
the plate is parallel with the nipple flange on the
stuffing box. If gas leaks are found, the packing
glands should be inspected.
When leaks in the packing are discovered, dismantle the
rapper assembly and inspect the stuffing box support
assembly for ash accumulations.
When reassembling the rapper assembly after maintenance,
make sure that the coil and coil cover are plumb and
level and that the plunger sits full-face on the rapper
rod.
The maintenance checks outlined above apply also to
wire rappers on hot precipitators.
3.1.3.3 Vibrators
Cold Precipitator
Inspect each vibrator for proper gas setting.
Inspect boot seal for holes or tears and replace if
necessary.
Inspect the service sheet gasket between the guide
plate and the mounting nipple for signs of deteriora-
tion and replace if necessary.
3-27
-------
If boot seal or service sheet gasket has deteriorated,
dismantle the rapper rod assembly and inspect the
vibrator rod nipple for ash accumulation. Packed ash
in this area will dampen the vibrations to the dis-
charge wires and cause excessive ash accumulation,
close electrical clearances, and reduced precipitator
performance.
Hot Precipitator
In addition to the instructions for vibrators on cold
precipitators, check the area where the rapper rod
passes through the packing ring retainer plate for ash
or for sign of inleakage of air and/or water. This
condition is indicative of a loose retainer plate
providing an inadequate seal between the packing and
the rapper rod or of failure of the packing rings. A
loose retainer plate should be tightened and in case of
gas leakage, the packing should be replaced.
3.1.3.4 Upper Precipitator
Top Housing
Inspect the fan to ensure that it is working and that
the filters are in good condition.
Inspect vent elbows for accumulation of foreign matter,
which would reduce or cut off the air flow.
Check access doors, inspecting the gaskets for signs of
deterioration and leaks. Replace defective gaskets and
lubricate door lugs and hinges as required.
Check that interlocks are clean, and lubricate with
powdered graphite.
Inspect the upper rapper (or vibrator) rod on the high-
tension frame to ensure that it is centered in its
guide nipple and that no fly ash has packed between the
nipple and the rapper/vibrator rod. If the rapper/
vibrator rod needs to be centered in the nipple, cover
the insulator with an asbestos blanket, and with a
torch cut the nipple loose from the cold roof. Reposi-
tion the nipple, centering the rod, and reweld the
nipple to the cold roof. Care must be taken that the
new weld is a complete seal; water and ambient air
could flow through pinholes and contaminate the in-
sulators.
3-28
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Note: Whenever it is necessary to do any welding on
the high-tension wire supporting frame, the electrical
bus connection to the high-tension support bushing
should be disconnected. A heavy, temporary ground,
sufficient to carry total welding current, should be
solidly connected to the high-tension frame. The
disconnected bus should be securely grounded at both
ends; i.e., in the rectifier ground switch enclosure
and at the support bushing end.
Insulator Compartments
Energize high-tension frame vibrators and check for
smooth operation. Check field wiring and vibrator
control cabinet if an inoperative vibrator is found.
Vibrator insulator nuts and all pipe plugs should be
secure.
Check all nipples and seals.
Inspect all dampers in the duct connections to the
compartments to ensure that they are in the open posi-
tion. Operate pressurizing fan and check that air is
flowing uniformly into each insulator compartment.
The vent elbow should be equipped with a pipe plug
unless the installation is operating under negative
pressure. If the installation is under negative pres-
sure, there should be no plug. Inspect the elbow for
ash and/or other foreign material.
Inspect the pipe and guard through the inspection hatch
to ensure that the inside surface is free from ash
accumulation and/or rust and scale. Remove all ash
accumulations and/or rust and scale buildups to prevent
high-voltage arcing from the pipe to the guard.
Inspect insulators to ensure that they are free from
cracks, chips, and dust accumulations. Replace any
cracked or chipped insulators and clean dirty insula-
tors with a nonabrasive cleaner.
Inspect the gasket on the inspection door for deteri-
oration and leaks; replace worn or leaky gaskets. Make
sure that all bolts are in place and securely fastened.
Determine that interlock is operable and well-lubri-
cated with powdered graphite.
Inspect upper rapper rod - see Section 3.1.3.3.
3-29
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Inspect the rapper rod insulator for ash accumulations,
chips, cracks, and electrical tracking. Electrical
tracking that has not damaged the glazed surface of the
insulator and ash accumulations should be cleaned off
with a nonabrasive cleaner. Replace cracked, chipped,
or glaze-damaged insulators.
Inspect the area between the rapper rod and the hanger
pipe for packed ash accumulations. Remove any accumu-
lation as it tends to dampen the vibration transmitted
to the upper high-tension frame. Check to see that the
rapper rod is centered in the support pipe. If the
support pipe is off center, chances are that the weld
between the lower rapper rod and the upper high-tension
frame has broken. Recenter the rod and reweld it to
the high-tension frame. As with the upper rapper rod,
inspect the insulator clamp, ensuring that all bolts
are in place and tight.
Check the high-tension frame support pipe. Inspect the
round nut screwed onto the support pipe to prevent pipe
movement.
Remove the cover plates and inspect the inside and
outside surfaces of the support insulator for dust
accumulations, electrical tracking, cracks, and chips.
Dust accumulations and electrical tracking that have
not damaged the glazed surface of the insulator should
be cleaned with a nonabrasive cleaner.
Plate Hanger Anvil Beam
Inspect the anvil beam hanger rod clips to ensure that
they are straight. Excessively heavy plate rapping can
in time cause these clips to bend, causing the plate
bank to shift out of alignment. This shift results in
electrical clearances out of tolerance and reduced
precipitator performance.
Inspect the hanger rods to ensure that none are broken,
missing, or bent. Broken, missing, or bent hanger rods
usually cause out-of-tolerance electrical clearance and
reduced precipitator performance. Replace any defec-
tive hanger rods.
Inspect the area behind the plate hanger anvil beam for
packed fly ash. Remove fly ash, since it can force the
beam out of plumb.
3-30
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Inspect the weld between the rapper rod and the anvil
beam. If this weld is broken or cracked, it should be
replaced.
Upper High-Tension Frame
Check bolts and welds on the high-tension frame.
Replace broken, bent, or missing support rods.
Check wire support angles for broken welds where they
attach to the spacer beam. Repair broken welds, making
sure that the wire support angles are parallel and on
9-inch centers.
Check to determine whether the high-tension frame is
level both perpendicular and parallel to the gas flow.
If the frame is not level in the direction of gas flow,
adjust at the appropriate high-tension frame support
rods. If the frame is not level perpendicular to the
gas flow, adjust at the appropriate high-tension frame
hanger pipes.
Check for excessive accumulation of fly ash on this
frame. Accumulations are excessive if they interfere
with specified clearances of 4-1/2 inches +_ 1/4 inch
between the discharge wires and collecting plates or if
they create a clearance of less than 4-1/2 inches
between the high-tension frame and any other grounded
surface.
3.1.3.5 Discharge Wires
Whenever possible, determine the condition of the
discharge wires with regard to dust buildup. The
amount of buildup will indicate whether the high-
tension vibrators, when furnished, are operating at the
proper intensity.
The discharge wires should be kept as clean as is prac-
tical.
Inadequate rapping of the discharge wires can result in
heavy dust buildup, with localization of the corona
current and excessive sparking.
A deposit on the discharge wires results from many
things, including poor gas distribution and charac-
teristics of the dust. Doughnut-shaped deposits often
are formed. They are composed generally of finer dust
3-31
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particles. Deposits on the discharge wires do not
necessarily result in poor performance, although de-
pending on resistivity, power supply range, and uni-
formity of the deposit, they can cause reduced effi-
ciency.
The discharge wires should be perfectly centered be-
tween the plates from top to bottom for optimum precip-
itator operation. Any broken discharge wires should be
removed and if time permits, replaced with new wires.
Since a cast iron weight is connected to each wire at
its lower end, a resistance will be felt when pulling
on the wire. A wire that gives no resistance is broken.
Broken wires can sometimes be seen from catwalks
located between the collecting plate banks. With a
flashlight, look down each duct noting any bottle
weight that is hanging on its bottle guide and any
wires that are out of alignment.
The location of a broken wire that is removed but not
replaced should be recorded on a permanent log sheet.
This recording will save time during future outages
when time permits the installation of a new wire. A
record of broken wire locations is also helpful in
determining the cause of wire breakage, i.e. if a
number of wires break in the same area of the pre-
cipitator, there are alignment problems. If the wire
breakage is random, the breakage is probably caused by
ash buildups on wires or plates.
The damaged wire may be cut away and the replacement
wire brought into the precipitator through the top
upper high-tension frame area, placed in the proper
duct, lowered into place, and attached.
3.1.3.6 Collecting Plates
Whenever the precipitator is out of service and in-
ternal inspections are possible, the collecting plates
should be checked for proper alignment and spacing.
Check all hangers. Make sure that spacers at the
bottom of the plates do not bind plates to prevent
proper rapping. Check the lower portion of all plates
and the portion of plates adjacent to any door openings
for signs of corrosion. If corrosion is present, it
usually indicates air inleakage through hoppers or
around doors.
3-32
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Observe the dust deposits on the collecting plates
before starting any cleaning of the precipitator. The
normal thickness of collected fly ash is about 1/8 inch
with occasional buildups of 1/4 inch. If the buildup
exceeds this amount, the intensity of the plate rappers
should be increased. If the collecting plates are
almost metal clean, this may be an indication of high
gas velocity, extremely coarse fly ash, too high a
rapping intensity, or too low an operation voltage for
good precipitation. This condition may be noted if a
section has been shorted out prior to the inspection.
The plate may be in effect removed from service by
removing the discharge wires surrounding it. When
bellying or bowing of the plates is noted, the concave
side of the plate may be heat-treated with a torch,
depending upon the severity of the deformity.
3.1.3.7 Lower Precipitator Steadying Frame
During periods when the hoppers are overfull, fly ash
exerts pressure on the guide rings and can severely
bend them. If the rings are bent upward, they usually
lift the weight and cause a slack wire. Slack wires
cause excessive sparking and/or grounds inside the
precipitator. If the rings are bent in the horizontal
plane, clearances will be reduced and sparking will
increase, resulting in reduced efficiency.
Cast iron weight rings that are bent out of their
normal configuration must be straightened. This can
usually be done by hand.
Inspect the steadying bars for cracked or broken welds
where they mount to the steadying bar support. Perform
any needed repairs.
Make sure that the lower steadying frame is level both
in the direction of gas flow and perpendicular to gas
flow. If the frame is not level, readjust the support
wires, adjusting both until the frame is level. Place
equal tension on each of the support wires connected to
adjusting bolts, since slack wires will cause excessive
sparking.
Inspect the steadying frame for downward bow in the
steadying bars (usually occurs after operating the
precipitator at overdesign temperatures). Downward
3-33
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bows can usually be removed by cutting a wedge-shape
slot in the vertical member of the steadying bar angle,
pushing with jacks or pulling with a block and tackle
until the frame is straight, then welding an additional
piece of angle iron inside the steadying bar angle and
across the wedge slot.
Inspect the steadying frame for twisting. A twisted
frame causes excessive weight on some wires and slack-
ness in others. To straighten a twisted frame, grasp
one end of the frame and twist the frame until that end
is straight and level. While holding the frame in this
position, weld the frame to the hopper walls. Repeat
for the other end of the frame. Once the frame has
been welded to the hopper walls and is straight and
level, using a torch, stress-relieve the frame by heat-
ing each connection between the steadying bar supports
and the steadying bars until it glows to a cherry red.
After all joints have been relieved, allow the frame to
cool, then cut it free of the hopper walls. If the
frame is still twisted, repeat the procedure. If after
the second heating the frame is still twisted, a new
frame will have to be installed.
When checking the lower steadying frame antisway
insulators, check the surface for ash accumulation,
glaze damage caused by electrical tracking, cracks, and
chips. Insulators with ash accumulation and/or elec-
trical tracking that has not damaged the glazed sur-
faces may be cleaned with a nonabrasive cleaner.
Cracked, chipped, broken, or glaze-damaged insulators
must be replaced.
3.1.3.8 Hoppers
It is extremely important to establish a regular sched-
ule of hopper emptying at the start of operation and
adhere to it as closely as possible, preferably once a
shift. If the hoppers are allowed to fill over a 24-
hour period or longer, the electrical components may
short out and precipitation will cease. Also, if a fly
ash hopper is allowed to stand for more than 24 hours,
the dust tends to pack, cool off, and absorb some
moisture from the gases. The dust is then extremely
hard to remove, and the presence of moisture can start
corrosion of the hopper steel. Dust often tends to
build up in the upper corners of the hoppers, espe-
cially if they have been filled completely at any time.
3-34
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I
Any abnormal buildups should be removed. If this
condition becomes chronic, it is an indication of low
operating temperatures, insufficient heat insulation,
or inadequate hopper emptying. Heat tracing of the
hoppers will usually correct this condition unless it
is due to inadequate hopper emptying.
3.1.3.9 Precipitator Shell
Combustion of coal usually produces small amounts of
sulfur dioxide and sulfur trioxide, as well as CO2, 02
and moisture. The traces of sulfur trioxide result in
fairly rapid corrosion of the interior of gas ducts,
fans, and dust-collecting equipment if these interior
surfaces become cool for any reason. It is therefore
recommended that thorough internal inspection be made
during the first year of operation. If interior corro-
sion is noted, apply some means of correction as soon
as possible. Heat insulation applied to exteriors of
the corroded components will normally correct this
condition. In installations where boiler loads are
periodically low, covering the interior surfaces of
side frames, end frames, and roof with gunite will
prevent damage to the steel.
3.1.4 Maintenance Schedule and Troubleshooting
3.1.4.1 Annual Inspection/Maintenance
Prior to any inspection, it is of utmost importance
that the precipitator is de-energized and grounded and
the necessary precautions are taken to ensure that the
equipment cannot be energized during the internal
inspection.
Dust Accumulations
Observe the dust accumulations on both plates and
wires. The discharge wires should have only a slight
coating of dust with no corona tufts (doughnut-shaped
ash accumulations). Thickness of dust buildup on
plates is normally between 1/8 and 1/4 inch. If the
plates have more than 1/4 inch of dust, the rappers are
not cleaning properly.
Discharge Wires
Replace any broken discharge wires, necked-down wires,
or fatigued wires to avoid the possibility of breaking
3-35
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during operation. Breakage of just one wire may render
an entire precipitator section inoperative. Record the
exact location of all wire failures as well as the
location of breakage on the wire.
Alignment of Plates and Wires
The plate-to-wire clearance at both top and bottom of
plates should not be less than 4-1/4 inches, while the
minimum acceptable plate-to-wire clearance at the
vertical midpoint of the plates is 4 inches (assuming
9-inch duct spacing). Close electrical clearances
create excessive sparking and prevent optimum opera-
tion.
High-Tension and Plate Rappers
Check all high-tension and plate rappers for misalign-
ment and/or binding of the rapper rods through the roof
sleeves. Binding in this area prevents transmission of
rapper energy to the collecting plates and high-tension
discharge wires and results in excessive dust accumula-
tions.
High-Tension Frame Support Bushing
The internal and external surfaces of the high-tension
frame support bushing must be maintained free of dust
to guard against high-voltage electrode tracking across
insulator surfaces. This condition will lead to ther-
mal fracturing of the bushings through heat concentra-
tion. Clean all high-voltage insulators and check
thoroughly for sign of cracks; replace where necessary.
All electrical connections should be secure.
High-Voltage Electrical Control Cabinet
Clean all components of dust accumulation and lubricate
where necessary. Replace the ventilating fan filter.
Transformer-Rectifier Sets
Check the oil level in the high-voltage transformer and
add the proper oil if necessary. Check all bushings,
terminals, and insulators for dust buildup and evidence
of electrical tracking. Check the surge arrester gap
setting on the high-voltage transformer and readjust if
necessary. Check high-voltage switchgear and inter-
locks.
3-36
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Hoppers
Check for dust buildup in upper corners of hoppers and
debris such as fallen wires and weights in the hopper
bottom and valves. Inspect antisway insulators to see
that they are clean and not cracked. If a discharge
electrode weight has dropped 3 inches, this indicates a
broken wire.
Precipitator Shell
Interior corrosion could indicate inleakage of air or
moisture through the housing. Exterior inspection
should focus on loose insulation and joints, air leak-
age, and general damage as well as corrosion.
3.1.4.2 Daily Inspection and Readings
Record all control set electrical readings once per
shift. Any abnormalities in shift-to-shift readings
may well be the first clue of a malfunction within the
precipitator. In addition, the daily log should in-
clude boiler operating data, flue gas analysis, coal
analysis, verification of transmissometer calibration,
and a record of all transmissometer readings.
Rappers
Ensure that all collecting plate and discharge wire
(high-tension) rappers are functioning properly and
operating at the proper intensity level. Lack of
rapping will result in dust buildup on both the plates
and wires, which reduces electrical clearances and
necessitates operation of the equipment at reduced
power levels. Over-rapping of the internals leads to
reentrainment of collected dust; therefore, it is
important that proper intensity values be used for
optimum precipitator performance.
Hoppers
Thoroughly check all hoppers, particularly the un-
loading mechanism and system, for proper operation.
Overfilling of hoppers can lead to very serious damage
of internal components. Check thoroughly for air
inleakage at the hoppers. The siphoning of cold am-
bient air into the hoppers usually results in formation
3-37
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of condensation and agglomerating of dust, result-
ing in plugging of the hopper.
A troubleshooting chart for ESP's is presented in Table
3-1.
3.1.5 Pr e c ip i t a to r Mal'f u'nc t ion s
Many precipitator components are subject to failure or
malfunction, which can lead to increased emissions. Faulty
design, installation, or operation of the precipitator can
cause these malfunctions. The reduction in efficiency is
variable and depends on the severity of the malfunction.
Many malfunctions are interrelated, with one malfunction
causing another. A brief discussion follows on common
precipitator malfunctions and how they affect emissions.
The most common malfunctions associated with precipita-
tors stem from broken discharge wires and plugged ash hoppers.
Other problems result from failure of rappers or vibrators
and suspension insulators, changes in coal specifications,
and boiler-related malfunctions or variations.
3-1.5.1 Broken Discharge Wires - When a discharge electrode
breaks, it usually causes an electrical short circuit
between the high-tension discharge wire system and the
grounded collection plate. This electrical short trips the
circuit breaker, disabling a section of the precipitator.
Electrical erosion, mechanical fatigue, and ash hopper
buildup are three common causes of electrode wire failure,
along with many others.
3-38
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Table 3-1. TROUBLESHOOTING CHART FOR ESP OPERATION
Symptom
CO
I
W
VO
Spark meter reads high, primary voltage
and current very unstable
Neither spark rate, current, nor voltage
at maximum
No spark rate indication, voltmeter and
ammeter unstable, indicating sparking
No response to current-limit adjustment,
response to other adjustments
No response to voltage-limit adjustment,
response to current adjustment
No response to spark rate adjustment,
response to other adjustment
Precipitator current low with respect to
primary current, low or no voltage across
ground return resistors
Probable cause
Misadjustment of automatic control, loss
of limiting control
Misadjustment of automatic control, auto-
matic control not at maximum, failure of
signal circuits
Failure of spark meter, failure of inte-
grating capacitor, spark counter sen-
sitivity too low
Controlling on spark rate or voltage
limit, failure of automatic control,
current signal to automatic control
defective
Controlling on current limit or spark
rate, voltage signal to automatic control
defective, failure of automatic control
Controlling on voltage or current,
failure of automatic control
Surge arrestors shorted, H.V. rectifiers
failed, H.V. transformer failed, ground
or partial ground in the ground return
circuit
Remedy
Readjust automatic control, replace
automatic control
Readjust setting of automatic con-
trol, readjust automatic control,
check signal circuits
Replace spark meter, replace capac-
itor, readjust potentiometer on
automatic control
None needed if unit is operating at
maximum spark rate or voltage adjust-
ment, reset voltage or spark rate if
neither is at maximum, replace auto-
matic control, check signal circuit
None needed if unit is operating at
maximum current or spark rate, reset
current and spark rate adjustment if
neither is at maximum, check voltage
circuit, replace automatic control
None needed if unit is operating at
maximum voltage or current, reset
voltage and current adjustment if
neither is at maximum, replace auto-
matic control
Reset or replace surge arrestors, re-
place H.V. rectifiers, replace H.V.
transformer, repair ground return
circuit
-------
Table 3-1 (Cont'd). TROUBLESHOOTING CHART FOR ESP OPERATION
Symptom
OJ
I
No primary voltage, no primary current,
no precipitator current, vent fan on,
alarm energized
No primary voltage, no primary current,
no precipitator current, vent fan off,
alarm energized
Control unit trips out on overcurrent
when sparking occurs at high currents
High primary current, no precipitator
current
No primary voltage, no primary current,
no precipitator current, vent fan on,
alarm not energized
Low primary voltage, high secondary
current
Abnormally low precipitator current and
primary voltage with no sparking
Spark meter reads high-off scale, low
primary voltage and current, no spark
rate indication
Probable cause
Transformer-Rectifier Controls
DC overload, misadjustment of current
limit control, overdrive of SCR's
Control panel fuse blown, loss of power
supply, circuit breaker tripped
Overload circuit incorrectly set
Short circuit in primary current,
transformer or rectifier short
SCR and/or diode failure, no firing
circuit
Short circuit in secondary circuit or
precipitator
Misadjustment of current and/or voltage
limit controls, misadjustment of firing
circuit control
Continuous conduction of spark counting
circuit, spark sounter counting 60 cycles
peak, failure of automatic control
Remedy
Check overload relay setting, check
wiring and components, check adjust-
ment of current-limit control set-
ting, check signal from firing cir-
cuit module
Replace fuse or reset circuit breaker,
check supply to control unit, reset
circuit breaker
Reset overload circuit
Check primary power wiring, check
transformer and rectifiers
Replace, check signal from firing
circuit
Check wiring and components in H.V.
circuit and pipe and guard. Check
precipitator for interior dust
buildup, full hoppers, broken wires,
ground switch left on, ground jumper
left on, foreign materials on H.V.
frames or wires, broken insulators
Check settings of current and voltage
limit controls
De-energize, allow integrating capac-
itor to discharge and re-energize,
adjust spark control circuit, replace
automatic control
-------
Table 3-1 (Cont'd). TROUBLESHOOTING CHART FOR ESP OPERATION
Symptom
00
I
Primary current and secondary current
normal, primary voltmeter drops from
normal to zero and remains for a second
then jumps back to normal, repeating
this sequence rhythmically
Circuit breaker trips
Fuses blown, indicator light not flashing
Indicator light not flashing, no fuse
failure
No manual intensity control
Vibrator inoperative
Abnormal ammeter reading
Line breaker trips
Probable cause
Broken wire, swinging frame
Rapper Controls
Short circuit or component failure in con-
trol circuit or power transformer
Control circuit failure, rapper coil
failure, distributor switch firing two
coils at once
Control circuit not operating effectively,
no rotation of distributor switch
Failed potentiometer, faulty intensity
control module
Vibrators and Controls
Vibrator coil open circuited, vibrator
improperly adjusted
Vibrator improperly adjusted, vibrator
coil short circuited
Short circuit in control wiring
Remedy
Remove broken wire, check for
broken anti-sway bushings
Check wiring and component
Replace defective component, re-
place coil, repair or realign dis-
tributor switch
Repair or replace component, check
motor and drive train
Replace potentiometer, replace in-
tensity control module
Replace coil, adjust vibrator
Adjust vibrator, replace coil
Check circuit
-------
The impact of wire failures on precipitator avail-
ability and efficiency is a function not only of the fre-
quency of failure, but also the degree of sectionalization
and the difficulty involved in removing failed wires during
unit operation. Most precipitatdrs do not have suitable
isolation dampers to allow safe access to the interior while
the boiler is in operation; thus, the unit must shut down
for removal of these broken wires. Inadequate sectionaliza-
tion causes a greater drop in efficiency, and a number of
wire breaks in different sections may seriously impair the
operation of the precipitator.
Design methods that can reduce wire failures include
fabricating discharge electrodes of the proper materials and
applying shrouds and rounded surfaces to reduce localized
sparking. Frequent inspection can help prevent failures
through detection of problems such as inadequate rapping and
ash hopper buildup before they cause wires to fail. Because
of the great number of wires in a precipitator, some wire
failure is to be expected, even with a good operation and
maintenance program.
3.1.5.2 Collection Hoppers and Ash Removal - Inadequate ash
removal is a major cause of precipitator malfunctions.
Most problems associated with hoppers are related to proper
flow of the dust. Improper adjustment of the hopper vibra-
3-42
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tors or failure of the conveyor system is usually the cause
of the hoppers failing to empty. Low flue-gas temperature,
which permits moisture condensation, can also cause plugging
of the hopper. This results from carrying the boiler exit
gas temperature too low or from excessive leakage of ambient
air into the hopper.
Buildup of ash can cause short-circuiting of the pre-
cipitator. It can also cause excessive sparking, which
erodes electrodes and sometimes pushes internal components
out of position, causing misalignment that can drastically
affect performance. Reentrainment of ash also increases
emissions.
Since ash buildup can affect so many of the precipita-
tor components, a proper inspection schedule of the ash
removal system is an important factor in the elimination or
minimizing of many common precipitator malfunctions.
3.1.5.3 Rappers or Vibrators - Poor performance can result
from rapping forces that are either too mild or too severe.
Although some reentrainment always occurs, effective rapping
minimizes the amount of material reentrained in the gas
stream. Rapping that is too intense and frequent results in
a clean plate, which causes the collected dust to become
reentrained rather than falling into the hopper. Inadequate
rapping of the discharge electrode results in a heavy dust
3-43
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buildup with localization on the corona, low corona current,
excessive sparking, impaired performance, and possible
grounding of the high-voltage system.
The first step in dealing with problems related to
rappers and vibrators is to determine the adequacy of the
rapping acceleration. An accelerometer can be mounted on
the plates for this purpose. An optical dust-measuring
instrument in the gas stream is commonly used to adjust the
rappers.
If discharge electrodes are kept as clean as possible
with minimum reentrainment, rapping intensity is then
limited only by the possibility of mechanical damage to the
electrodes and support structure.
3.1.5.4 Insulator/Bushing Failure - Suspension insulators
are used to support and isolate the high-voltage parts of
precipitators. Inadequate pressurization of the top housing
of the insulators can cause ash deposits and/or moisture
condensation on the bushing, which may result in electrical
breakdown. Fouling and cracking of insulators reduce the
effective voltage levels and collector performance but
rarely decommission a bus section.
Corrective or preventive measures include inspection of
ventilation fans for the top housing and availability of a
spare fan for emergencies. Frequent cleaning and checking
3-44
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the fans for damage from vibration are also necessary to
ensure trouble-free operation.
Table 3-2 lists common precipitator malfunctions, their
causes, the effects on emissions, and the corrective action
required.
3.1.6 Operational Procedures and Firing Practices That
Affect Emissions2
In addition to precipitator malfunctions, a number of
operating and coal boiler firing practices can affect pre-
cipitator emissions. Changes in these practices can also
cause precipitator malfunctions, which may in turn degrade
performance.
3.1.6.1 Gas Volume - Any increase in boiler load that
results in excessive flow through the precipitator will
cause a loss in efficiency. For example, if a precipitator
is designed for a velocity of 3 ft/sec and an efficiency of
99 percent, an increase in velocity to 4 ft/sec (a 33 per-
cent load increase) will decrease the efficiency to about
97 percent.
3.1.6.2 Temperature - A change in operating temperature may
also affect precipitator efficiency. Particle resistivity
varies greatly in the temperature range of 200 to 400°F.
Ignoring the effects of temperature on gas volume, the
impact of temperature on efficiency depending on the coal
composition could be as follows, assuming a 1.5 percent sul-
3-45
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Table 3-2. SUMMARY OP PROBLEMS ASSOCIATED WITH ESP'S
Mn 1 f unct ion
Cause
Effect on ESP Efficiency3
Corrective
act ion
Preventive
measures
1 . Poor electrode al ignment
2. Broken electrodes
CO
I
3, Distorted or skewed
electrode plates
4. Vibrating or swinging
electrodes
1) Poor design
2) Ash buildup on frame hoppers
3) Poor gas flow
1) Wi rf> not rapped clean, causes an arc
which embrittles and burns through
the wire
2) CJ. ink^red wire. Causes: aJ ppnr flow
area, distribution through unit ia
uneven? b) excess free carbon because of
excess air above combustion requi re-
men ts or f*n capacity insufficient
for demand required: c) wires not
properly centered; d) ash buildup re-
sulting In bent frame, same as c);
e) clinker bridges the plates & wire
shpr ts out; f) ash buiIdup, pushes
bottle weight up causing sag in the
wire; g) "J" hooks have improper
clearances to the hanging wire; h) bot-
tle weight hanqs up during cooling
causing a buckled wire; i) ash build-
up on bottle weight to the frame
forms a clinker and burns off the wire
1) Ash buildup in hoppers
2) Gas flow irregularities
3) High temperatures
1) Uneven gas flow
2) Broken electrodes
Can drastically affect performance
anH lower efficiency
Reduction in efficiency because of
rcrtucnd power input, bus sect ion
unavailability
Reduced efficiency
Decrease in efficiency caused by
reduced power input
Realign electrodes
Correct gas flow
Replace electrode
Repnir or re-
place plates
Correct gas flow
Repair electrode
Check hoppers frequently
for proper operation
Boiler problems: check space
between recording steam & air
flow pens, pressure gauges; fouled
screen tubes.
Inspect hoppers
Check electrodes frequently for wear
Inspect rappers frequently
Check hoppers frequently for
proper operation; check electrode plates
during outages
Check electrodes frequently
for wear
The effects of precipitation problems can only be discussed on a qualitative basis. There are no known emission
tests of precipitators to determine performance degradation as a function of operational problems.
-------
Table 3-2 (Cont'd). SUMMARY OF PROBLEMS ASSOCIATED WITH ESP'S
Malfunction
S. Inadequate level
of power input
(voltage too low!
«. Back corona
?. Broken or cracked inaulator
or flower pot bushing '
leakage
hoppers
». Mr inlaakags through ESP
10. Gas bypaas around ESP:
^ dead paassgs above
platea
- around nigh-tenslon
11. Corrosion
Cause
11 Blgh duat resistivity
21 EBceeeive aah on electrodes
1) unusually fine particle alia
4| Inadequate power supply
SI Inadequate seetionaUiation
il Improper rectifier and control operation
T) Hiaalignmant of eleetrodee
1) ash accumulated on olectrodee - causes
eveeeaive aparking requiring reduction
in voltage charge
11 aah buildup during operation cauaaa
leakage to ground .
11 Hoiature gathered during ahutdown
or low load operation
1> Prom dust conveyor
1) Flange expansion
11 Poor design - improper isolation
of active portion of ESP
1) Temperature goes below dew point
Eft act on ESP Efficiency*
maduetloi in efficiency
Eeductloi in efficiency
Eeductioi In efficiency
Lower efficiency - duat resatraimad
through iSP
Sams SB ibove, also causes intense
aparking
Only few percent drop in efficiency
unlaaa aavare
negligible until precipitator interior
plugs or platea are-eatsn awayi air lease
may develop cauaing signif icsnt drops in
Corrective
action.
- Clean alactrodaei
gss conditioning
or slterntlsms
in tamp, to re-
duce resistivity)
increase seetiom-
ellastien
fame ae above
Clean or replace
insulator* t
buahinge
Seal leaks
Baffling to direct
gas into active
EEP section
maintain flue gas
temperature above
dew point.
manssrss
Check range of volteges
frequently to make sure they
are correct
In alto reaistivity measursnenta
Same as above
Check frequently
Cleen and dry aa needed) cheek for
adequate preasurirstion of top housing
Identify early by increeae in aah coneen-
tretion at bottom of esit to ESP
Identify eerly by meesurement of eas
flow in auapeeted areas
Energise preclpltetor after boiler system haa been
online fir ample period to raise flu. ... t.»r»r.
ture above acid dew point
* The effects of precipitation problems can, only be discusssd on a qualitative basis. There are mo known emission
teete of pracipitotore to determine performance degradation aa a function of operetlcnel problems.
-------
Table 3-2 (Cont'd). SUMMARY OF PROBLEMS ASSOCIATED WITH ESP'S
Malfunction
1 2 . Hopper p 1 uggage
1 3 . Inadequate rapping ,
vibrators fail
14. Too intense rapping
IS. Control failures
1 6 . Sparking
Cause
1) Wires, plates, insulators fouled
because of low temperature
2) Inadequate hopper insulation
3) Improper maintenance
5) Ash conveying system) gasket leakage
malfunction ) blower malfunction
) solenoid valves
6) Misadjustinent of hopper vibrators
7) Material dropped into hopper - from
bottle weights
8) Solenoid, timer malfunction
9} Suction blower filter not changed
1) Ash buildup
2) Poor design
3) Rappers misadjusted *
1) Poor design
2 ) Rappers mi and justed
3) Improper rapping force
1) Power failure in primary system
2) Transformer or rectifier failure
a. insulation breakdown in trans-
former
h. arcing in transformer between
high voltage switch contacts
c. leaks or shorts in high voltage
structure
d. insulating field contamination
1) Inspection door ajar
2) Boiler leaks
3) Plugging of hoppers
4) Dirty insulators
Effect on ESP Efficiency8
Reduction in efficiency
Resulting buildup on electrodes may
reduce efficiency
Reentrains ash, reduces efficiency
Reduced efficiency
Reduced efficiency
Corrective
action
Provide proper
flow of ash
Adjust rappers with
optical dust measur-
ing instrument in
ESP exit stream
Same as No. 13
Find source of
failure and
repair or replace
Close inspection
doors; repair leaks
in boiler; unplug
hoppers ; clean
insulators
Preventive
measures
Frequent checks for adequate operation
of hoppers.
Provide heater thermal insulation
to avoid moisture condensation
Frequent checks for adequate operation
rappers
Same as No. 13
Reduce vibrating or impact force
Pay close attention to daily readings
of
of control
room instrumentation to spot deviations from
normal readings
Regular preventive maintenance will alleviate
these problems
u>
I
^
00
a The effects of precipitation problems can only be discussed on a qualitative basis. There are no known emission
tests of precipitators to determine performance degradation as a function of operational problems.
-------
fur coal, and 99 percent guarantee at 325°F (fly ash appli-
cation) :
Temperature, °F Efficiency, %
200 =99.6
325 99
400 ' = 99.4
Any change in the sulfur content of the coal along with
other parameters such as sodium, would cause the above
efficiencies to change differently with temperature. Changes
•«.
in fuel are discussed below.
3.1.6.3 Fuel - Any significant change in the type of fuel
being fired will affect precipitator performance. Sulfur
»
content is one of the significant factors. For example,
changing from a bituminous coal with 2 percent sulfur to a
subbitiuminous western coal with 0.5 percent sulfur can
result in a design efficiency of 99.5 percent dropping to 90
percent or less. Other chemical constituents, such as
sodium oxide, in the ash can affect performance by reducing
bulk resistivity (see Section 2.0).
The unit should be designed for the lowest quality
expected fuel.
3.1.6.4 Inlet Loading - Since a precipitator is designed to
remove a certain percentage (by weight) of the entering
material, a 50 percent increase of the inlet concentration
will cause the outlet concentration to increase by the same
3-49
-------
amount if no other factors change. This increase can be
expected to result in greater opacity.
3.1.6.5 Carbon - Variations in firing practice or coal
pulverization that affect the quantity of cqmbustibles in
the fly ash also have been impact on,precip4.tator perform-
ance. Carbonaceous,materials readily take on an electrical
charge in a precipitator but, lose their charge quickly and
are readily reentrained. The carbon particle is very con- ,f
.ductive and is also large and light in comparison with the
other fly ash constitutents• ,;;.:
These are the major operating parameters to be con-
sidered in preventing a deterioration in performance,
3.1.7 Reduced.ESP Collection Efficiency as Related to
Number of Bus Sections Not in Operation
Although ESP collection efficiency is reduced by mal-
: - .=••••:.;: j>- \'\ ••..•:. •••,••, • . . , • y .• • :•• ; ,. , • • v--;j _,.,.,-.
functions such as breakage of discharge wires and deteriora-
tion of power supply components, rectifiers, insulators, and
' -' r ' ' • ••'•> :'''•••••'•'. - • )' *>'" ' ; • • .' '• ' ' . '' • ;'' / '• --
similar equipment, a unit can often be kept in compliance
with particulate emission regulations by reducing boiler
- • • •*•>-, , • . . ,. ,
load. Figure 3-8 (top graph) illustrates collection effi-
ciency of a four-field ESP with 24 bus sections as a func-
- -,'• '•* :••••• v,u.. i : '• ;•;•••
tion of the gross boiler load, depending on the number of
bus sections out and whether they are in series or parallel.
•i- ,,.•-•
The bottom graph shows the efficiency needed by the ESP to
meet a state regulation of 0.38 lb/10 Btu as a function of
3-50
-------
I
ui
99.0
z 98.0
97.0
o
H-
O
96.0
95.0
98.0
97.0
~ 96.0
95.0
10
A4 B4 C4 04 E4 F4
A3 B3 C3 D3 E3 F3
A2 B2 C2 02 E2 F2
Al B1 Cl 01 El F1
COLLECTOR SECTION ARRANGEMENT
GAS FLOW
CURVE A
300
CURVE B
SECTIONS OUT
0
1 OUT
2 OUT IN PARALLEL
3 OUT IN PARALLEL
4 OUT IN PARALLEL OR
2 OUT IN A SERIES
5 OUT IN PARALLEL OR
2 OUT IN SERIES AND 1
6 OUT IN PARALLEL OR
2 OUT IN A SERIES AND
OUT IN PARALLEL
2 OUT IN PARALLEL
EXAMPLE: LOAD 290 MW
SECTIONS OUT Al, A2. C2, F4
(CURVE A) EFFICENCY AT 290 MW WITH 2 OUT
IN A SERIES AND 2 OUT IN PARALLEL - 95.3
COAL-ASH 14%
MOISTURE 10S
(CURVE B) EFFICIENCY REQUIRED TO MEET
STATE REGULATIONS - 96.52
TO MEET STATE REGULATIONS REDUCE
LOAD TO 210 MM
12
14
16 18
ASH IN COAL, %
20 22
24
Figure 3-8
Typical operating curve to meet emission regulations
with partial malfunctions of ESP.
-------
the ash content of coal (assuming a heating value of 11,000
Btu/lb).
These types of graphs are extremely helpful to the
utility operator. Knowing the ash content of the coal he is
firing and knowing which bus sections of his ESP are inoper-
ative, he can easily tell from the top graph how much the
boiler load must be reduced to keep emissions in compliance
with regulations. Charts of this type must be developed for
each boiler-ESP combination.
3.2 OPERATION AND MAINTENANCE OF WET SCRUBBERS
The selection of wet scrubbers over electrostatic
precipitators for use with coal-fired boilers has been
motivated in many instances by the relatively poor perfor-
mance of the first electrostatic precipitators on boilers
firing low-sulfur Western coals. A few years ago scrubbers
were beginning to look like a good prospect for collection
of fly ash. A number of scrubbers were installed for col-
lection of particulate from boilers burning low-sulfur
Western coal. Examples are the Pacific Power and Light
Company, Public Service of Colorado, and Minnesota Power and
Light Company. At the Arizona Public Service Cholla Station,
removal of both SO- and particulate was accomplished. Six
commercial-scale scrubber modules have been installed in the
West to remove S02 from power plant stack gas. This
3-52
-------
report, however, considers only those scrubbers designed
principally for the collection of fly ash.
Of the new Western coal-fired boilers being built,4
virtually all are using precipitators for particulate con-
trol followed by scrubbers for removal of SO-. This situa-
tion is the reverse of what was projected a few years back.
Several of the problems that contributed to this change in
control plans are as follows:
0 With the scrubber, the fan can no longer be operated
dry, creating potential for corrosion and imbalance.
0 In many cases, the desulfurization system cannot be
bypassed without also bypassing the particulate removal
system.
0 The chemistry of the S02 system and the total slurry
solids content are affected by the particulate loading.
Many of the problems with wet scrubbers arose from the
newness of the application. The occurrence of erosion,
corrosion, scaling, and plugging underscores the need for
development of scrubber technology. Both corrosion and
buildup decrease the efficiency of particulate removal, the
finer particles being the ones most likely to escape collec-
tion. No clear trend emerges as to the preferred scrubber
system for use in collection of fly ash from utility boilers.
Not enough scrubbers have been installed to allow meaningful
performance evaluations. Of the pilot and full-scale units
placed in operation thus far, only three have been used with
any success: the gas-atomized spray scrubber (venturi and
3-53
-------
flooded-disc scrubbers), the preformed spray impingement
scrubber (spray tower type), and the turbulent contact
absorber (TCA) (moving-bed scrubber type). The installa-
3
tions that serve as a basis for the discussions that follow
are the Four Corners Station of Arizona Public Service; the
Dave Johnston Station of the Pacific Power and Light Com-
pany; the Valmont, Cherokee, and Arapahoe Stations of the
Public Service Company of Colorado; and the Clay Boswell and
Aurora Stations of the Minnesota Power and Light Company.
Using available information, the remainder of this section
describes these scrubber systems and the maintenance pro-
cedures used to maintain efficient operation.
3.2.1 Gas Atomized Spray Type Scrubber
3.2.1.1 Description - In devices of this type a moving gas
stream atomizes liquid into drops and then accelerates the
drops. Acceleration of the gas provides impaction forces as
well as intimate contact with the liquid stream. The typi-
cal gas atomized spray devices are the venturi scrubber and
the flooded disc scrubber. Whereas in the venturi liquid is
introduced at the throat, in the flooded disc scrubber the
liquid is introduced slightly upstream of the throat, flows
over the edge of the disc, and is atomized.
Within this category many differences in design and
operation are noted with respect to the following items:
method of adjusting pressure drop (the difference being with
3-54
-------
regard to the true venturi and the annular orifice); the
method of introducing water (spray or cascade); and the
method of eliminating moisture (spinning vanes or multi-
centrifugals) . In any event, most gas atomized spray
scrubbers incorporate the converging and diverging section
typical of the venturi throat.
High-efficiency particulate wet scrubbers of the ven-
turi type are being used at the Four Corners Plant of the
Arizona Public Service Company, and at the Dave Johnston
Plant of Pacific Power and Light Company. At the Four
Corners plant, as shown in Figure 3-9, flue gas from the air
preheaters enters the venturi and is then channeled through
a mist eliminator, a wet induced-draft fan, another mist
eliminator, and steam reheaters (although reheaters have not
been used recently). Scrubber liquor is recycled continu-
ously from the cyclone separator back to the venturi.
Blowdown from the cyclone is sent to the thickener, lime is
added, and the thickener underflow is diluted before being
sent to ash ponds.
The installation at the Dave Johnston Station is some-
what different (Figure 3-10). Flue gas from the air pre-
heater enters the venturi and is channeled through the mist
eliminator, a wet induced-draft fan, and a wet stack. No
reheat is used, and, as with the Four Corners scrubber,
there is no bypass.
3-55
-------
TO STACK
FLUE GAS FROM
AIR HEATERS
MIST ELIMINATORS
AND REHEATER
FLY ASH
TRANSFER TANK ®
LIQUID TRANSFER
TANK
Figure 3-9. Simplified flow diagram of fly ash
scrubbers, Four Corners plant.3
-------
FLUE GAS FROM
AIR HEATERS
COOLING TOWER SLOWDOWN
CLEAR POND./
FLY ASH POND
Figure 3-10. Simplified flow diagram of fly ash
scrubbers, Dave Johnston plant.
3-57
-------
Scrubbing liquor is continuously recycled from the
bottom of the venturi back to the plumb bob and to the
deflector surrounding the bob. Slowdown from this loop is
pumped directly to the ash ponds, where the solids settle
without addition of thickener. Clear liquor from the set-
tling pond along with cooling tower blowdown are pH treated
and pumped to the recycle loop.
At the Lewis and Clark Station, the gas, after passing
through a mechanical collector, is pushed through the flood-
ed disc by a forced-draft fan. A limestone slurry is used
as a reagent for pH control. The flue gas then passes
through a mist eliminator and out the stack. A portion of
the liquid reagent is recycled. The remainder is discharged
to a waste pond. Figure 3-11 presents a simplified diagram
of the Lewis and Clark station's flooded disc scrubber.
3.2.1.2 Normal Operation - In view of the few applications
of scrubbers for collection of fly ash from coal-fired uti-
lity boilers and the wide variations in design within any
scrubber category, no specific list of items can be said to
constitute 'normal1 operation. Some qualitative aspects of
scrubber operation are discussed briefly.
Efficiency of collection of submicron particles in-
creases with increasing pressure drop. For the Four Corners
and Dave Johnston plants, the operating pressure drops are
28 inches and 15 inches (water gauge), respectively. Pres-
3-58
-------
U)
I
Ul
VD
FLUE GAS FROM
MECHANICAL COLLECTOR
BOOSTER F.D.
FAN
SPRAY QUENCHING
/FLOODED-DISC
SCRUUBER
GAS FLOW
DISC FEED
STACK
LIMESTONE BIN
\
MIST
ELIMINATOR
SCRUBBER
RECYCLE
SUMP
8-
MAKE UP WATER
y
LIMESTONE
SLURRY TANK
WASTE
POND
Figure 3-11.
Simplified flow diagram of fly ash scrubber,
Lewis and Clark plant.
-------
sure drop of the flooded disc scrubber at the Lewis and
Clark Station is 12 to 13 inches of water. At system pres-
sure drops of about 20 inches, liquid distribution has an
important effect on equipment performance. It can be as-
sumed that efficiency will be somewhat lower in a venturi at
low pressure drops when liquor is introduced through a weir
rather than through sprays.
Efficiency can be improved by increasing the liquid-to-
gas ratio; after a certain point, however, increasing the
amount of liquid will not enhance particulate collection
efficiency. Furthermore, moisture reentrainment can cause
increased emissions. For this reason, mist eliminators are
always required.
3.2.1.3 Operational Procedures for Start-up and Shutdown
Preoperational Checks — As with the precipitator sys-
tems, it is important that all of the major items of equip-
ment, connecting pipe, and auxiliaries be inspected, cleaned,
and tested before startup.
General preoperation practices include checks to ensure
that piping is free of debris, oil levels are correct, fans
and pumps rotate in the proper direction, and alignments
appear proper. More specifically, checkout of the following
items should be done in accordance with manufacturer's
recommendations:
3-60
-------
Utilities
Power supply
Instrument air
Process air
Pumps
Belt tensions, pump rotation, pump alignment,
lubrication, seal water operation, and electrical
interlocks.
Recycle pumps - suction and discharge valves.
Flush water pumps
Pneumatic pumps for flooded disc control and
liquid level.
Spare pump availability and operation.
Valves/dampers (stack, isolation, bypass)
Bypass
Density control
Water purge control
pH elements flush water
Reagent slurry control
Pond return
Fresh water make-up
Disc control (flooded-disc scrubber)
ID/FD Fan
Electrical controls
Fan bearing coolant water
Lubrication
Vibration sensors
Bearing temperature sensors
3-61
-------
Process water
Level detector calibration
Mist eliminator sump level alarm calibration
Mist eliminator sump agitator
Recycle pump
System controls/feedback controls
Stack gas flow
Make-up water control
Reagent feeder rate
Slurry pH
Reagent dissolver level
Slurry density
Sludge drainoff and disposal
Safety system
Interlocks
Alarms for various system components according to
design of system.
Start-Up Procedures
Energize motor control center, fan controller, and con-
trol panel.
Turn compressed air supplies on (both plant and instru-
ment air). Check to see that domestic water is ready
for process, coolant to fan bearings is sufficient,
holding tanks are filled, pump is on automatic, and
slurry pumps are ready.
Following the manufacturer's instruction manual, close
drain valves; ensure that bypass is in operation, and
that all process and control lines are clear.
Start Slurry System
This entails activation of process water booster pumps,
scrubber flushdown program, slurry circulating pumps,
and reagent feeder systems.
Start ID/FD Fan
Check that inlet damper is closed and interlocks are
satisfied.
3-62
-------
Start Sludge System
Activate sludge-to-thickener controls, sludge pumps,
delumper, and all associated equipment.
Shutdown
Stop fan.
Stop reagent feed.
Flush scrubber. This may not be necessary for short
outages, in which case some process control flow
circuits may be kept operational, i.e. any flow cir-
cuits that carry slurry.
Slurry circulating pumps should be on as long as there
is slurry in the system.
Shut down reagent feeder, then slaker.
As slurry tank levels become too low for slurry to
circulate, dilute tank slurry, drain off to pond, and
turn process off.
Flush and drain slurry pumps and close suction and
discharge valves on the slurry pumps.
3.2.1.4 Inspection/Maintenance During Normal Operation
and Common Malfunction Areas - Many of the items on the
preoperation checklist should be checked in routine mainte-
nance. The maintenance performed generally includes unplug-
ging lines, nozzles, pumps, etc.; replacing worn pump parts,
erosion/corrosion prevention liners, and instruments (level
indicators, pH indicators, etc.); and repairing damaged
components when this is practical from the standpoint of
labor and materials.
The following checklist is based on problems encoun-
tered in scrubber operation. These should be checked rou-
3-63
-------
tinely and corrected: by the manufacturer's recommended
procedures.
Check for wear in the throat section. Heavy wear:
occurs in areas downstream of the acceleration. Sili-
con carbide brick or replaceable wear liners help to
extend throat life.
If abrasion is high, inside the scrubber and* large
particles predominate the size distribution/, check
operation of the quench chamber.
Check for excessive scaling below disc of flooded disc
scrubber. This can be caused by process changes such,
as changes in= temperature, pH, chemical composition of
the dust, or chemical composition of the make-*up water;
reduced liquor recycle rate; increase in the inlet
loading; or failure of solids removal system.
Check the nozzle for buildup.and/or damage.
replacement may be necessary.
Repair or
Check for solids buildup in blowdown lines. Cleaning
may be effected without system shutdown,, and a flush
connection may be installed, to prevent this condition
in the future.
Check for corrosion and leaks in lines and vessels
where protective liners may have deteriorated. Replace
liners as required.
Check operation of mist eliminator. Formation of
droplets can be caused, by excessive gas flow. rate,.
plugged drains from the moisture eliminator, or con-
densation in the outlet duct. Check structural sup-
ports and agitator for structural integrity and smooth;
operation.
Check pumps for wear, seal water, packing, and smooth
operation.
Check dampers and damper linkages for proper position-
ing and wear.
Check fan for lubrication, fan bearing coolant, belt
wear and belt tension, and impeller erosion/corrosion..
3-64
-------
Inspect all interior surfaces and condition of holding
tanks during major outages.
Inspect exterior for leaks in all process and control
lines, ductwork, and expansion joints.
Note the condition of all instruments, e.g. level
probes, and pH elements, with regard to solids buildup.
It is impractical and usually impossible to remove
solids buildup from the probes, and the probes must be
replaced.
Check the reagent system and associated equipment for
proper functioning (lime feeder, slaker, thickener and
rake mechanism, and delumper).
Perform a final check for proper operation of pH
sensors, density sensors, lime feed rate control, and
level elements.
3.2.2 Preformed Spray Impingement Scrubber
3.2.2.1 Description - The scrubbing efficiency of this type
of scrubber is dependent on distribution of the liquid in
the gas by means other than the gas velocity. Particles or
gases are collected on liquid droplets atomized by use of
high-pressure spray nozzles. The properties of the nozzle,
the liquid to be atomized, and pressure determine the
characteristics of the liquid droplets. Spray towers can be
used for both mass transfer and particle collection; they
represent probably the least expensive method for achieving
mass transfer. Particle collection is principally by
impaction, but is usually limited by the terminal settling
velocity and diameter of the spray droplets.
3-65
-------
The Minnesota Power and Light Company operates similar
horizontal spray chambers at its Clay Boswell and Aurora
plants. Nozzles located in the stainless steel enclosures
direct a high-pressure spray against baffles, causing the
spray to be finely atomized. Also, the induced turbulence
promotes effective scrubbing of particulate.
The flow circuit for the Clay Boswell scrubber is shown
in Figure 3-12. As indicated, liquid is pumped from a seal
tank at the bottom of the spray chamber to two clarifiers
(not provided at the Aurora Station). The overflow is then
combined with make-up water and pumped back to feed the
spray nozzles.
3.2.2.2 Normal Operation - Again, the operation of a scrub-
ber is very specific to the site and the manufacturer's
design.
Particulate removal efficiency depends upon the droplet
size and opportunity for intimate contact of particles and
liquid. For high efficiencies, nozzle pressures will exceed
200 psig. According to one test, the efficiency can be
comparable to that of a venturi and the preformed spray
impingement scrubber consumes equivalent energy.
Depending on the particle size distribution, increasing
the number of nozzles, liquid rate, or nozzle pressure may
provide significant positive effects on scrubber perfor-
mance.
3^66
-------
MAKE-UP WATER
TO STACK
POST HUMIDICATIONA
SPRAY '
QUENCH
SPRAY ~*"
*jnn
MIST ELIMINATOR
PUNCH PLATE
FLY ASH POND
Figure 3-12. Simplified flow diagram for the particulate
at the Clay Boswell station.
3-67
-------
Gas atomizing and sonic nozzles can produce small
droplets, but only at the expense of power consumption.
Collection of fine particulate can be effected, of
course, by increasing gas retention time but only at the
expense of increased scrubber size.
3.2.2.3 Operational Procedures For Start-up and Shutdown -
Preoperational Checks - The instruction manuals pro-
vided by equipment manufacturers should supersede any check-
list presented here. The items listed for preoperation
check of the gas atomized spray scrubber (Section 3.2.1.3)
are applicable to spray towers also.
3.2.2.4 Start-Up/Shutdown - Again, follow the manufac-
turer's instructions for any given unit. Essentially all of
the items mentioned in Section 3.2.1.3 apply here.
3.2.2.5 Inspection/Maintenance During Normal Operation
and Common Malfunction Areas - The points presented
with respect to inspection and maintenance of gas atomized
spray scrubbers (Section 3.2.1.4) are applicable. Potential
problem areas with high-pressure spray impingement scrubbers
that should be checked include the following:
Check for nozzle problems. The high velocity causes
potential erosion and the small orifices can be easily
plugged.
Check wet induced-draft fan for plugging.
Check for scaling in the scrubber liquid circuit.
3-68
-------
Check for stack gas mist carryover in the scrubber and
liquid circuit.
3.2.3 Moving-Bed Scrubber
3.2.3.1 Description - Moving-bed scrubbers are designed to
provide intimate contact between flue gas and liquid. The
gas passes through a zone of mobile packing, which rests on
a perforated plate. Liquid is either sprayed up from the
bottom through the perforated plate and/or from the top down
onto the perforated plate. The recirculation liquid flow
rate and gas flow rate must be controlled within specified
limits to create proper turbulence of the bed, thereby
keeping the packing elements clean. If the gas and liquid
flow rates are too high, the spheres will be carried upward
and be held in a semistationary state against the underside
of the top grid. In this latter condition, liquor can build
up above the top grid and a condition known as flooding will
develop. Flooding will be indicated by excessive pressure
drop across the scrubber. The pressure drop across the
scrubber is an indication of scrubbing action. Efficient
scrubbing action occurs if the pressure drop is within the
specified limits (7 to 12 in. water). The operating tempera-
ture of the TCA must not exceed 170° to avoid damage to the
rubber lining and plastic spheres.
The only scrubbers of this type applied successfully to
utility installations are at the Valmont, Arapahoe, and
Cherokee stations of Colorado Public Service. A typical
3-69
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arrangment is shown in Figure 3-13. At the Valmont station,
flue gas is treated first with a mechanical collector, then
channeled with a booster fan through the scrubber to the
chevron mist eliminator, and on to a reheater. The Arapahoe
and Cherokee stations use electrostatic precipitators
following the mechanical collector and before the scrubber.
3.2.3.2 Normal Operation - Using the Cherokee Station
scrubber as an example, the flue gas from the precipitator
passes into two parallel induced draft fans. A bypass
damper is used to direct the flue gas into either the stack
or the scrubber. The flue gas enters the booster fans to
offset the pressure drop through the scrubber. In the
presaturator, the makeup water is sprayed into the gas to
reduce the temperature to approximately 125°F. From the
presaturator, the gas enters the scrubber. The scrubber
consists of three stages of fluidized beds with 1.5-inch
diameter plastic balls arranged into three separated paral-
lel scrubber sections. The two outer sections each handle
20 percent of the flow, while the center section handles the
remaining 60 percent. All three sections can operate
independently to provide flexibility of operation. The
scrubber liquor is then pumped from the bottom of the scrub-
ber to a header equipped with spray nozzles at the top of
the packing. Under normal operation, a portion of the
3-70
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FLUE GAS TO REHEATER
FLUE GAS FROM
ELECTROSTATIC
PRECIPITATOR
CLEAR EFFLUENT
DISCHARGE
MAKEUP WATER
MIST ELIMINATOR
Figure 3-13. Typical scrubber installation at Valmont, Cherokee,
and Arapahoe Stations, Public Service Company of Colorado.
3-71
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slurry is purged from the system to prevent buildup of
solids. This slurry is pumped to an ash pond for disposal.
The scrubbed gas passes through a Chevron-type mist
eliminator made of fiberglass-reinforced plastic where
entrained droplets are removed. The mist eliminators are
sprayed from the top once per shift to prevent accumulation
of solids.
The gas is then heated by steam coils to 185°F before
entering the stack to prevent corrosion of the stack and
ductwork and to provide plume buoyancy after discharge into
the atmosphere. The steam coils are equipped with two sets
of soot blowers to remove fly ash from the heat transfer
surfaces.
3.2.3.3 Operational Procedures For Start-Up and Shutdown
Preoperational Checks - Before start-up is initiated,
all of the major items of equipment, connecting pipe, and
auxiliaries must be inspected, cleaned, and tested. The
manufacturer's instruction manuals will specify the checks
that apply to the unit. In general, all the preparation
checks listed earlier are applicable here, except with
regard to the reagent system. In the TCA's discussed above
(Colorado Public Service Stations) reagents are not normally
used.
In addition, the following equipment should be checked
in accordance with the manufacturer's recommendations:
3-72
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Induced-draft fans
Bypass damper (isolation and stack dampers)
Booster fans (to overcome pressure loss across the
scrubber)
Presaturator
Three stages of mobile balls
Scrubber liquor pump
Spray nozzles
Purging apparatus (to remove suspended solids from
slurry)
Chevron-type mist eliminators
Steam coils (reheater coils)
Start-Up
Make a final check to insure that all internals have
been installed in accordance with the instructions and
accompanying drawings.
Carefully review all utility connections and ductwork;
inspect all filters for debris; and check all presatura-
tor, recycle liquor, trapout and demister wash nozzles
for proper operation.
Set the scrubber inlet high temperature alarm at 150°F.
Start flow to presaturator and demister nozzles at the
prescribed rate, and check for proper distribution of
water and functioning of nozzles.
When the recirculation liquid in the external recircula-
tion tanks is at the desired level, start the recircula-
tion pumps and adjust flow to the design rate. Check
the distribution of the recirculation header to make
sure that all nozzles are functioning properly.
Start the fan. If the damper is available to control
gas flow, close the damper during start-up of fan.
When fan has reached its operating RPM, slowly open
the damper until the design gas flow and pressure drop
are obtained.
3-73
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Check the pressure drop and temperature differences
across the unit. Compare these values with design
values. If a discrepancy appears, check the system for
gas flow, gas temperature, gas distribution, liquor
flow, and liquor distribution.
Continue to monitor process variables after the scrubber
is operating satisfactorily.
Shutdown
Reduce the gas flow through the scrubber by closing the
TCA inlet and outlet dampers.
Shut off the fan after damper is completely closed.
Shut off presaturator liquid flow, recirculation liquid
flow demister wash flow, and deflector tray wash flow.
3.2.3.4 Inspection/Maintenance During Normal Operation;
and Common Malfunction Areas
Routine maintenance suggested by the manufacturer
includes the following inspection procedures:
Open access doors and visually inspect the scrubber
internals such as grids, spheres, headers, and demister.
Check periodically for proper operation of pressure,
temperature, and flow sensors.
Clean scrubber sumps periodically to remove solids
which may have built up.
Check periodically to verify proper operation of the
recirculation liquid nozzles, deflector tray wash
nozzles, demister wash nozzles, and presaturator nozzles.
Check the chevron demister for buildup on the blades.
If significant buildup is present, the blades must be
cleaned or plugging will occur, causing excessive
pressure drop across the demister.
Based on actual operation at Colorado Public Service
generating stations, the following items are indicated as
3-74
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problem areas that must be inspected consistently:
Check condition of mobile bed contactors. The basic
problem is that, because of the turbulent nature of the
system, the spheres wear out prematurely or break
apart. In addition, sphere fragments falling through
the grids and into the recirculation pumps severely cut
the rubber linings. As a further consequence of
deterioration of mobile balls, fragments may pass
through the pump and plug the nozzles in the recircula-
tory system. Screens installed to prevent this passage
of fragments into the recirculation system must be
checked often for plugging. Cleaning of the screens
may necessitate system shutdown.
Check vertical partitions for structural integrity and
position to prevent migration of mobile-bed contactors.
Migration of the spheres because of improper position-
ing of a vertical partition so that it blocks a portal
can allow gas to channel through the empty section and
thereby reduce contacting efficiency. Reduction of the
pressure drop across the scrubber below 8 inches w.g.
would indicate that channeling of the gas is occurring
and a shutdown for repair is imminent.
Check guillotine isolation dampers. An ash buildup in
the duct may prevent the guillotine damper from closing
completely and thereby shear the motor couplings.
Leaky dampers cause excessive ash buildup over the
drive train motors, gear boxes, and couplings; this
will hinder operation and create an unworkable atmos-
phere for maintenance personnel.
Check recirculation pumps. If V-belts on overhead
motors are too tight, they should be readjusted to
prevent excessive wear on motor bearings. Adhere to a
periodic schedule of lubrication and cleaning of motor
parts.
Check reheater section. Check condition of the steam
coils for signs of corrosion. Since the service life
is a direct function of the performance of the mist
eliminators, condensed slurry corrodes and helps plug
subcooling coils and fins respectively. This problem
may be aggravated by reentrainment of slurry droplets,
which is caused by higher-than-design flue gas veloc-
ity. The excessive velocity can be caused by backflow
at the edges of the mist eliminators caused by duct
section that expands at too great an angle.
3-75
-------
Check rubber-lined piping. Where rubber lining is
designed to protect stainless steel pipes, care should
be taken to ensure that the covering is complete and in
good condition. Y-sections lined with rubber are
particularly vulnerable and should be checked regularly
for signs of failure.
Check for buildup in the presaturator. Since the job
of the presaturator is to cool the flue gas to near the
saturation temperature of the gas with water sprays,
buildup of soft solids may occur in the area of the
wet-dry interface. These accumulations may fall into
the scrubber hopper screens and cause plugging. Cor-
rection may require reorientation of the nozzle sprays.
Check mist eliminators for signs of corrosion and
erosion and increased pressure drops due to plugging.
Inspect stack damper interlock system to ensure that
the system is failsafe and that isolation and stack
dampers respond quickly to the interlock system. All
dampers should be clean and free-moving.
Check booster fan bearings. Ensure a clean atmosphere
around all moving parts by providing soot blowers and
following a regular lubrication schedule.
Inspect for weather-related problems. Freezing weather
can cause dampers to lock up and can freeze water and
slurry lines (process lines). All lines (process and
control) should be properly insulated and heat-traced.
In conclusion, although many of the required operation
and maintenance procedures are the same, each type of scrub-
ber has its own characteristic problems, which are discussed
in the inspection and maintenance sections.
3.3 OPERATION AND MAINTENANCE OF FABRIC FILTERS
Regular maintenance and proper operation of fabric
filters are critical to good performance. Although most
plant personnel realize the importance of these factors,
proper records of operation and maintenance are seldom kept.
3-76
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D
The Nucla study conducted by GCA did not include main-
tenance but was concerned with normal and abnormal operation
of the baghouse during testing to determine the effects of
operating variables on baghouse performance. These effects
were discussed in Section 2.0. An early study on fabric
Q
filters by GCA does present detailed maintenance procedures,
however, many of which could be applied to fabric filters
for collecting fly ash. A more recent study of the Nucla
baghouse, sponsored by the Electric Power Research Institute
(EPRI), has systematically analyzed maintenance and opera-
tion procedures and their effects on performance as well as
g
costs. Results of this study are not yet available. Some
data are reported on the Sunbury baghouse operation by the
manufacturer (Western Precipitation). Reference 11 and a
12
recent EPA-sponsored study discuss performance and costs
of maintenance and operation of the Sunbury baghouse. No
information is available on maintenance and operation of the
Holtwood baghouse. The available data on the Sunbury fa-
cility, and general maintenance procedures applicable to
all types of fabric filters are summarized below.
3.3.1 Sunbury Baghouse
The recommended preoperational checks, start-up and
shutdown procedures, and maintenance practices used at
Sunbury are presented below and are based on information
reported in Reference 11 and 12.
3-77
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3.3.1.1 Preoperational Checks - The following checks are
recommended prior to start-up:
0 Test control air lines (hydrostatically).
0 Check air dryers that supply control air to the
bag filters.
0 Check ash removal system.
0 Inspect collapse air fans for alignment and rota-
tion.
0 Check seals at gas inlet, collapse air, and gas
outlet damper.
0 Check baghouse compartments, remove debris.
0 Check filter bags for proper installation and
tension.
0 Check and sweep thimble floors clean. Dust build-
up on floor during operation is a positive indica-
tion of a broken bag.
0 Calibrate pressure drop recorders and transmitters.
0 Check pressure taps for leakage.
0 Coat filter bags with fly ash prior to light-off
(fly ash coating is required to prevent blinding
by fuel oil during start-up).
3.3.1.2 Start-Up - Before a new set of bags is placed in
service, each bag is precoated with fly ash remaining in the
boiler gas passes to prevent blinding of the bags with the
oil used during boiler start-ups. The boiler is brought on
the line and the baghouse cleaning cycle is not activiated
until 1 hour after coal is fired. This allows an additional
coating to form on the bags.
3-78
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3.3.1.3 Shutdown - Approximately 15 to 20 minutes before
taking the last mill and exhauster out of service, the
collapse air fan is de-energized. This preserves the filter
cake on the bags and prevents blinding by the fuel oil
residue during the ensuing start-up period. The cleaning
cycle controls remain in service during the entire outage to
continuously exercise the gas inlet and collapse air dampers.
When a boiler is taken off line for furnace and gas
pass cleaning, it may be necessary to restart the collapse
air fan during the outage to clean the bags. Pressure drop
must be monitored during the shutdown. If it rises to 3 in.
H^O because of dust collected from the gas passes, the
collapse air fan will be placed in service for one complete
cleaning cycle and then taken out of service. This process
may be repeated as necessary. It must be kept in mind,
however, that because a fly ash coating on the bags prior to
start-up is very desirable, good judgment must be used when
cleaning the filter bags during an outage.
3.3.1.4 Maintenance During Normal Operation - It is re-
ported13 that most maintenance hours at Sunbury have been
spent on bag replacement, collapse air fan repairs, and air-
operated damper repairs. Although little data are available
on maintenance of fabric filters relative to collection of
fly ash, many maintenance procedures can be applied to all
3-79
-------
types of fabric filters. This section summaries some of
these procedures.
Inlet Ducting
Common problems such as abrasion, corrosion, sticking
or plugging of fly ash, and settling must be dealt with on
a routine basis. Abrasion can be reduced with special
materials at bends in ducting, for example. Corrosion can
be minimized by supplying insulation, especially in long
duct runs, which are most susceptible to moisture condensa-
tion. Regular inspection will help control plugging and
settling problems in ducts.
Blast Gate and Flow Control
Problems with flow control equipment are reported
frequently. The blast gate valve is especially vulnerable
and should be checked periodically and adjusted. Filter
compartment inlet dampers are a high-maintenance item, and
spare parts should be stocked. A bad damper seal can
shorten the life of bags in a shake-type system, and caking
bags, if not replaced, can foul valves on the clean side
of the baghouse and cause them to malfunction.
Fans
Fans and blowers are reported to be a large problem
area, particularly those located on the dirty side of the
baghouse where material can accumulate on the vanes and
3-80
-------
throw off the balance. Corrosion and abrasion can also
cause problems.
Condensation and corrosion in the fan may be alleviated
with duct and fan insulation. Most fan housing can be
drained, and the drains should be checked on a regular
basis.
Air flow and fan speed should be measured periodically
and belt condition and tension determined; the fan should
also be checked for direction of rotation. These checks can
be combined with routine lubrication procedures.
Collapse Fan Repairs
At Sunbury, collapse fan failure is detected from
increased differential pressure signals. When a main
collapse fan fails, the spare collapse fan is put into
service by opening blast-gate (butterfly-type) dampers. The
spare fan is normally filled with fly ash caused by leakage
past the blast gate dampers, and normally the fan is cleaned
out before it is put into service. This takes as much as 2
to 3 hours. Originally, the spare fan was isolated by
sliding gate dampers. These dampers provided a tight seal;
however, they were difficult to open and close. It took
four men with a chain hoist approximately 4 hours. As a
temporary measure, the spare fans were pressurized with
compressed air to prevent inleakage.
3-81
-------
Damper failures can sometimes be detected by observa-
tion of the differential pressure chart. As the dampers
open and close the differential pressure swings. If a
damper fails, the absence of this pressure swing leaves a
"gap" on the differential pressure chart. If a high dif-
ferential pressure alarms/ the dampers are routinely checked
for proper operation. If not, the operator must go up to
the baghouse and visually observe damper operation through
the complete cycle (a total of 32 minutes).
Entrance Baffles
Baffles may be added to improve distribution of the gas
to each compartment and bag. The baffles should be adjust-
able, however. Also, they may cause problems by accumu-
lating dust or abrading too rapidly.
Hoppers
Hoppers are a common problem in any fly ash collection
system. Ash flow can be facilitated by the use of vibrators
and/or heaters (if they work properly); by lining the hop-
pers with antifriction material; by the use of air-pulsed
rubber-lined hoppers; by placing poke holes in the side of
the hoppers; or by insulation if condensation is a problem.
Regular inspection (once per shift) of the hopper is
mandatory to alleviate problems with the suction removal
system or bridging in the hopper before the problems become
serious.
3-82
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Bag Replacement
In most filter systems, the biggest part of the main-
tenance program is related to fabric upkeep.13
At Sunbury, all baghouse compartments are inspected
during each annual boiler outage. If an accumulation of
dust is found on the compartment floor, each bag in the
compartment is inspected for possible failure, and all
failed bags are replaced.
To replace a bag with the boiler in service, the asso-
ciated compartments are isolated by closing the gas inlet
and outlet dampers. The lower and upper doors of the com-
partment are opened to allow ambient air to circulate. The
cover is removed from the vent stack, and a portable 7000-
cfm fan is set on the vent stack and started to provide
forced ventilation. It normally takes 3 to 4 hours to
ventilate the compartment sufficiently for men to enter to
replace the failed bag, and it is still necessary that they
12
wear masks to prevent inhalation of sulfur dioxide. The
entire procedure (isolating and ventilating the compartment,
finding the leak, replacing the bag, and returning the
compartment to service) takes approximately 6 to 8 hours.
Bag failures are detected by daily observations of the
opacity meter charts. When a bag has failed, the opacity
meter senses the increased particulate emissions; generally,
3-83
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the stack discharge is not visible. The opacity meter chart
will indicate a periodic spike in sequence with the cleaning
cycle. There will be a decrease in the reading when the
compartment with the failed bag is removed from service, a
spike when the compartment is returned to service, and a
settling out to a higher-than-normal reading. Some spikes
are not easily discernable, and a careful study of each
chart is necessary. Also some nonperiodic spikes occur, but
these do not indicate an abnormal condition.
When it is determined which compartment has the failed
bag, the compartment is taken out of service. The opacity
meter readings then return to normal. The compartment is
entered, and each of the 90 bags is inspected. An accumu-
lation of fly ash on the compartment floor is a telltale
sign of an actual bag failure in the compartment. However,
bag failures have been found in compartments with no fly ash
accumulations. The bags are inspected by holding a flash-
light at the bottom of the bag and shining it up the side of
the bag. Any tears are illuminated in this manner. Also, a
slight tap on the bag will, if there is a failure, cause a
stream of fly ash to flow from the bag, which is illuminated
by the light, thus providing an additional check for failures,
The failed bag is replaced, the compartment floor is
cleaned, and the compartment is returned to service.
3-84
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Tension
The amount of bag tension required for best overall
performance varies between manufacturers. A bag that is too
slack can fold over at the lower cuff and bridge across and
wear rapidly. Too much tension can damage the cloth and
the fastenings. Correct tension is a function of filter
dimensions and cleaning mechanism. Shake cleaning in par-
ticular seems to require a unique combination of tension,
shake frequency, and bag properties for best results.
In any event, the manufacturer's recommendations should be
followed and the tension checked periodically, and espe-
cially a few hours after installing a new bag.
Spare Stock
It is advisable to have a complete set of filter
elements in stock, in case of an emergency. The spare
filter elements should be clearly labeled and kept well-
separated from used filter elements.
Inspection Frequency
External maintenance inspection of the filter house is
usually performed daily, whereas the filter elements them-
selves are typically inspected once a week to once a month.
Shake Cleaning
The shaking machinery should be checked periodically
for wear. If the bags are not being cleaned properly, some-
times a minor adjustment of the shake amplitude of frequency
3-85
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can markedly improve cleaning. If a safe amount of shaking
still does not properly clean the cloth, it may be necessary
to reduce the filtration velocity for a few hours.
Reverse-Flow Cleaning
With this type of cleaning, the only maintenance
requirement is to periodically check the rate of flow (back
pressure) and the timing to keep the residual drag at an
economical level.
Shake and Reverse-Flow Cleaning
As in the case of shake cleaning, wherever the bag is
flexed, the rate of wear is apt to be high. This is espe-
cially common near the thimbles, as was the cage at the
Nucla plant (section 2.6.10.3). The maintenance procedures
outlined for the shale and reverse-flow methods also apply
here.
Ins trumentation
Proper operation of fail—safe mechanisms and automatic
control instrumentation is very important to the safety of
the filter cloth. The location of all sensing instruments
should be checked to see that the proper temperature, air
i
flow, etc. are being measured. All instruments should be
calibrated after installation and rechecked monthly for sen-
sor location, leaks (manometer), sticking, and legibility.
The instrument readings covering one complete operating
cycle should be recorded for future use in routine checks
3-86
-------
and trouble shooting. This record should be posted beside
each instrument.
3-87
-------
REFERENCES - SECTION 3.0
1. The Electrostatic Precipitator Manual. The Mcllvaine
Company. Copyright 1976.
2. Bump, R.L. Research Cottrell, Inc. Electrostatic
Precipitators In Industry. In: Chemical Engineering,
January 17, 1977.
3. Sondreal, E.A. , and P.H. Tufte. Scrubber Developments
in the West. U.S. ERDA, Grand Forks Energy Research
Center, Grand Forks, North Dakota. 1975.
4. Mcllvaine Electrostatic Precipitator Newsletter. April
20, 1976.
5. Research Cottrell, Inc. Flooded -Disc Scrubber, Montana-
Dakota Utility - Lewis and Clark Station, Unit No. 1.
June 1976.
6. Calvert, S., et al. Wet Scrubber Manual, Volume II.
7. Ensor, D.S. , et al. Evaluation of a Particulate Scrub-
ber on a Coal-Fired Utility Boiler. Prepared by
Meteorology Research, Inc., and others for EPA Contract
No. 68-02-1802. November 1975. pp. D-13 - D-19.
8. Bradway, R.W., and R.W. Cass. Fractional Efficiency of
a Utility Boiler Baghouse, Nucla Generating Plant.
NTIS Document No. PB 245541. August 1975.
9. Private Communication with R.C. Carr of EPRI on March
23, 1976.
10. Meyler, J.A. One Year of Bag Filter Operation in a
Coal Burning Power Plant. Presented to the American
Power Conference, April 30, 1974.
11. Waner, N.H., and D.C. Houserick. Sunbury Steam Elec-
tric Stations — Unit Numbers 1 and 2, Design and Oper-
ation of a Baghouse Dust Collector for a Pulveri zed-
Coal -Fired Utility Boiler. Presented at the Spring
Meeting of the Pennsylvania Electric Association, May
17-19, 1973.
3-88
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12. Cass, R.W., and R.M. Bradway. Fractional Efficiency of
a Utility Boiler Baghouse—Sunbury Steam Electric Sta-
tions. EPA Report No. EPA-600/2-76-077a. March 1976.
13. Billings, C.E., Ph.D., and John Wilder, SCD. Handbook
of Fabric Filter Technology. GCA Corporation, GCA
Technology Division. Contract No. CPA-22-69-38.
Bedford, Massachusetts. December 1970. pp. 8-9 to
8-21.
3-89
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4.Q FRACTIONAL EFFICIENCY RELATIONSHIPS
Up to this point, this report has dealt with the rela-
tionship of input variables to control device design and
costs for various application areas. Recall that an appli-
cation area is defined with respect to coal type, boiler
type, and overall mass efficiency level. This information
along with typical data on fly ash size distribution at the
collector inlet was used in developing a computer model that
predicts percent penetration (the portion of particulate
that escapes the collection devices) versus particle size
for electrostatic precipitators. Computer models have also
been developed to predict percent penetration as a function
of particle size for gas atomized spray (venturi) TCA, and
high-pressure spray impingement scrubbers. These models are
based on the data described above and also on values for L/G
ratio and system pressure drop. In this section, the assump-
tions and descriptions of the models are presented, along
with the results of computer runs. For a 500-MW power
output, precipitator costs are calculated for different
levels of control for particles in the 0.2 to 0.4 micron
range.
4-1
-------
In the assessment of fractional and total mass effi-
ciencies of fabric filters, performance data for the Nucla
and Sunbury baghouses are presented. Since minimal infor-
mation is available on percent penetration as a function of
particle size below 1 micron, additional fractional effi-
ciency data are presented from a pilot plant fabric filter
on an industrial pulverized-coal-fired boiler.
No computer model is presented in this report for
predicting the fractional efficiency of fabric filters as a
function of particle size. A suitable model is presently
not available for predicting the fractional collection
efficiency of fabric filters, as applied to this study.
4.1 LIMITATIONS OF CURRENT DATA
Only in the past 4 or 5 years has particle size distri-
bution been measured and recorded with any regularity by
control equipment manufacturers, independent testing com-
panies, and consultants; and because of operator error and
the inherent technical limitations of some particle-sizing
instruments, reliable data are still not readily available.
Meaningful evaluation of fine particulate emissions will
require development of a reliable and consistent fine-
particle measuring technique that can be applied widely. A
broadly applicable technique for compliance monitoring of
4-2
-------
fine-particle sources would have the added advantage ena-
bling the collection of valuable data concerning various
coal/boiler applications and operating conditions.
4.2 SUMMARY OF INLET PARTICLE SIZE DISTRIBUTION DATA
USED FOR PRECIPITATOR AND SCRUBBER COMPUTER MODELS
Table 4-1 summarizes size distribution data obtained
from several sources by different particle-sizing tech-
niques. These data represent measurements at the collector
inlet. Because of the high degree of scatter, "standard"
statistics have been selected from the literature to charac-
terize only the effect of boiler type on the particle size
distribution at the outlet of the boiler. Coal type, of
course, also influences particle size distribution, particu-
larly whether the coal is soft or hard and how it is affected
by preparation procedures. The data of Table 4-1, however,
do not allow differentiation on the basis of coal type.
References providing the input for Table 4-1 are listed at
the end of Section 4.0.
4.3 ELECTROSTATIC PRECIPITATOR COMPUTER MODEL
The electrostatic precipitator computer model computes
size distribution at the precipitator outlet, based on inlet
size distribution and overall mass collection efficiency.
From the inlet and outlet distributions, fractional ef-
ficiencies can be calculated directly.
4-3
-------
Table 4-1. SUMMARY OF INLET PARTICLE SIZE DISTRIBUTION DATA
l
*»
Case
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Utility name/station
TVA/Widows Creek,
Unit 5
Union Electric/
Meraraec
TV A/ unidentified
TVA/unidentified !
Illinois Power/
Wood River, Unit 4
Col. Ute Elec./Nucla
North Dakota Lignite/ !
unidentified ;
North Dakota Lignite/
unidentified
North Dakota Lignite/ ;
unidentified
Iowa Pub. Serv./
George Neal
Kansas City Power &
Light/Montrose, Unit 1
So . Cal . Ed/Mohave
Hot-side utility/
unidentified
Ala. Power/Gorgas,
Unit 10
Location
Bridgeport , TN
St. Louis, MO
—
—
East Alton,
IL
Nucla, CO
Sioux City,
IA :
Ladue, MO
near Bullhead
City, AZ
;
Birmingham,
AL
Type
Bitumin-
ous
30% ash
Bitumin-
ous
Bitujnin-
ous
Bitumin-
ous
Bitumin-
ous
Subbitum-
inous
Lignite
(Baukol)
Lignite
(Beulah)
Lignite
(Beulah)
Subbitum-
inous
Subbitum-
inous
(Amax)
Subbitum-
inous
Sutobitum-
inous
Bitumin-
ous
Coal
Sulfur, %
0.7
2.46
1.64
1.64
2.82
0.70
0.96
0.96
0.96
0.81
5.52
0.38 :
—
1.43
Na20, %
2.0 ;
1,0
6.0
Firing
method
PC
PC
PC
PC
PC :
STO
PC
PC
CYC
PC
PC
PC
PC
PC
Inlet particle
size distribution
characteristics
3f
13.8
11.0
24.3 ;
24.0
20.0 I
18.0
5.20
8.60 ;
18.0
34.0
5.6«
14.0
21.0
22.5
erg
2.26
3.44
2.35
2.33
3.15 ;
3.16 :
4.04 :
2.91
5.56
4.72
3.57
5.34
2.62
2.93
Particle
sizing
method
Brinks cascade
impactor
Brinks
impactor
Brinks
impactor
Brinks
impactor
Cascade
impactor
Anderson
Mark III
Bahco
Bahco
Bahco
Brinks
impactor
Bahco sub-
sieve
Bahco
Modified
Brinks cascade
Modified
Brinks
-------
4.3.1 Design Equations and Assumptions - Electrostatic
Precipitators
2
The following relationships are used in the program to
determine particle collection as a function of particle
sxze.
The electrical force on a charged particle in an elec-
tric field is given by:
F = qEp (1)
where E (by the Deutsch model) is the electric field
strength at the precipitator collecting electrode. (See
Table 4-2 for definition of all terms. Units are m k s
system.) The force opposing particle motion through the gas
is:
F = 3irydwd/C (2)
Equating the forces and solving for the migration velocity of
particles of size d:
wd = qEp°
ITjId (3)
C is the Cunningham correction factor given by:
C = 1 + 2.5X/d + 0.84X/d exp (-.435d/X) (4)
The particle charge q can be represented by the Cochet
equation:
4-5
-------
Table 4-2. NOMENCLATURE FOR ELECTROSTATIC
PRECIPITATOR COMPUTER MODEL
A
a
C
d
d
E.
g(d)
k
Q
q
w
w,
n
-1
precipitator collecting area, m
defined by equation (6), dimensionless
Cunningham correction factor, dimensionless
particle diameter, m
geometric mean particle diameter, m
effective charging field, (V/m)
effective precipitating field, (V/m)
force, N
inlet particle size distribution function, m
defined by equation (10), m
defined by equation (9) , m~
volumetric gas flow rate, m /sec
particle charge, C
Deutsch effective migration velocity, m/sec
migration velocity for particle of diameter
d, m/sec
permittivity of free space, 8.86 x 10~12 F/m
overall collection efficiency, dimensionless
k
collection efficiency for particles of diameter d
mean free path of gas molecules, m
gas viscosity, kg (m/sec)
geometric standard deviation of size distribution,
dimensionless
4-6
-------
The Cochet equation accounts for particle charging by
both field charging and diffusion charging mechanisms. This
is important in analyzing the effects of particle size,
since the charging mechanism changes from field to diffusion
in the submicron range.
Combining (3) and (5) and defining
2
(1 + 2Xd)
the particle migration velocity for particles of size d
becomes:
e E E
"a = <-VL£) acd
For particles of a single size, d, the Deutsch equation
can be applied to calculate collection efficiency:
(1 - nd) = exp [5^] = exp [-(l^P-) (aCd] (8)
Defining new terms:
]; . £QEQEPA
k ~ 3yQ (9)
g(d) = aCd (10)
the single-size efficiency equation becomes:
(1 - nd) = exp [-kg (d)] (11)
The overall collection efficiency is found by integrating
over the inlet size distribution, f ^ (d) :
(1 - n) = /" d - nd) f1 (d) dd (12)
4-7
-------
Assuming a log normal inlet distribution, this becomes:
(1 - »> - 'o eXPf-kg(d) - 0.5 )] dlnd (13)
The above procedures can be used to determine outlet
size distribution and fractional efficiencies (or percent
penetration). An important effect that the program cannot
model is that of reentrainment of particles on fractional
efficiency. This limitation is discussed in Section 4.3,2.
Nomenclature for the above equations is defined in Table
4-2.
4.3.2 Percent Penetration as a Function of Particle Size
For Electrostatic Preeipitators^ ........ *""""" —-— ~"- ~~ ~
Predicted penetration as a function of particle size is
presented for electrostatic precipitator applications in
Figures 4~1 through 4-3. Use of the computer program shows
»?
an important result; a minimum in efficiency in the parti-
cle size range of 0.2 to 0.4 micron for pulverized-coal-
cyclone-and stoker-fired boilers (Figures 4-1 through 4-3 ,
respectively) . This observed minimum is probably caused by
the changing particle charging rates from the diffusion and
field charging mechanisms. The particle size range between
0.1 and 1.0 micron represents a transition region where
particles begin to exhibit actions characteristic of gases.
Diffusion charging is related to the motion of negative ions
in the gas stream caused by their thermal velocity (Brownian
4-8
-------
x = 12, a = 3.8
(inlet)
0.01 0.020.03 O.OSO.OS.'IO .2 .3 .4 5 6--8 1.0 Z 3 4 56 810
PARTICLE SIZE, microns
Figure 4-1,
Percent penetration, pulverized-coal-fired
boiler (cold-side ESP).
4-9
-------
100
I I
r i
TO
LU
1.0
.01
x » 6.0, a * 3.33
(INLET)
.10 l.Q
PARTICUiATE' SIZE, MICRONS
i i
10
Figure 4-2. Percent penetration, cyclone-fired
boiler (cold-side ESP).
4-10
-------
0.1
x = 68, a = 3.54
(inlet)
0.01 0.02 0.03 0.05 .08.10 0.2 .3 .4.5.6 .8 1.0
PARTICLE SIZE, microns
2 3 456 8 10
Figure 4-3. Percent penetration, stoker-fired
boiler (cold-side ESP).
4-11
-------
motion), and field charging results from the flow of nega-
tive ions along the direction of the electric field.
Field data on coal-fired boilers confirm this obser-
vation. Figures 4-4 through 4-7 present fractional effi-
ciencies obtained in tests of precipitators at the Gorgas
Station of Alabama Power Company, the Wood River Station of
the Illinois Power Co., an unidentified hot-side installa-
tion, and an unidentified western subbituminous-fired boiler,
respectively. The Gorgas, Wood River, and hot-side installa-
tion are pulverized-coal-fired boilers. The data for the
western subbituminous-fired boiler show predicted versus
test values on the same graph.
As mentioned earlier, the program cannot model the
effect of reentrainment of particles on fractional effi-
ciency. In the process of reentrainment, fine particles
form agglomerates on the collecting plates and are reen-
trained as larger particles. Thus, the measured fractional
efficiencies must show a decrease at the larger particle
sizes. The data in Figure 4-7 {lignite boiler) show an
apparent increase in penetration at a particle size of 6
microns. Note the agreement between computed and measured
fractional efficiency at particle sizes below the size range
where reentrainment becomes obvious.
4-12
-------
j Jr • yy
99.95
99.9
99.8
99.5
99
98
95
90
80
** 70
z 60
2 50
< 40
*• tj 30
M UJ on
U> Q_ £U
10
5
2
1
0.2
0.1
i i I i i I I I i r™i — i IIIM 1 1 i i i i i i fl-Oi
-I0.05
• DIFFUSIONAL -fe.l
-fo.2
4 INERTIAL J0>5
• OPTICAL "I1
-12
-J5
H10
-J20
-J30
-|40
H50
-160
-J70
• -J80
A 1
| -190
• *•':**? I95
• • f _ -J98
~ A H99
4
• -199.8
-J99.9
i i i i i u i i i i I I i I i 1 i i i i i i i i 1
0.01
0.1 1.0
PARTICLE SIZE, microns
10
Figure 4-4. Measured efficiency as a function of particle size for
Precipitator Installation at the Gorgas Plant of Alabama Power Company.
Source: (Reference 3)
-------
I
M
it*
99.9
99
90
50
1.0
.01
• 10/14/73
O 10/19/73
X 10/20/73
D 10/21/73
A 10/22/73
DIFFUSIONAL DATA
OPTICAL DATA
i
i
0.01
O.T 1.0
PARTICLE SIZE, microns
.01
1.0
o
LU
50
90
99
o
o
99.9
10
Figure 4-5. Fractional efficiencies fc-r the Wood River Precipitator.
Source: (Reference 4)
-------
O
I—I
i
40
30
20
10
5
2
1
0.5
0.2
0.1
0.02
MEASUREMENT METHOD:
V CASCADE IMPACTORS
— _
O OPTICAL PARTICLE COUNTERS
+ DIFFUSIONAL
— —
PRECIPITATOR CHARACTERISTICS:
TEMPERATURE - 335°C
y SCA - 85 M2/(M3/sec)
_ CURRENT DENSITY - 35 nA/CM2 -
0^0
v y
~+ + +
^
-
S7
1 1
60
70
80
90
95
98
99
99.5
99.8
99.9
99.98
0.05
O
I—I
u.
u_
UJ
z
O
I—I
O
O
O
0.1
0.5
1.0
5.0
10.0
PARTICLE SIZE, microns
Figure 4-6. Average fractional efficiency for a
hot-side ESP installation.
Source: (Reference 3)
-------
100
80
60,
50
40
30
20
10
8
6
5
4
3
LU
1.0
.8
.6
.5
.4
.3
.2
0.1
T 1—pi 1—T f 1—i1 | T" T"
ACTUAL FIELD DATA -
&- 98 3%
B- 98.8%
<3" 98.6%
O- 99.2%
X- 99.5%
(inlet: x<*3.2; o=2.72)
PREDICTED BY ESP MODEL
FOR n = 99%
i i ii
i i
LI
0.1 0.20.3 0.5
1.0
2 3456 8 10
20 30 50 80 100
PARTICLE SIZE, microns .
Figure 4-7. Computed versus actual percent penetration
for cold-side ESP on a western subbituminOus-fired boiler.
4-16
-------
4.3.3 Projected Costs of Fine Particulate Control -
Electrostatic Precipitators
The projected costs of fine particulate control with
cold-side and hot-side electrostatic precipitators are
presented in Tables 4-3 and 4-4, respectively. The data are
based on assumptions of no particle reentrainment, gas
nonisoturbulence, and absence of gas sneakage. Temperatures
of 700°F and 300°F are assumed for representative hot-side
and cold-side precipitators, respectively.
As mentioned earlier, in the absence of reliable data
on inlet fly ash size distribution the influence of coal
type on fractional efficiency is not shown. The influence
of significant coal characteristics for the various applica-
tion areas is shown clearly, however. The information
presented is intended to support two points: (1) in estab-
lishing a fine particulate emissions standard, both frac-
tional efficiency in collection of the most difficult
particles to collect (those in the 0.2- to 0.4-micron range)
and overall mass efficiency must be considered; and (2) for
low-sulfur coal applications, a hot-side precipitator is
often a more economically attractive alternative to a cold-
side precipitator.
Selected cases from Tables 4-3 and 4-4 are presented in
Tables 4-5 and 4-6 respectively and discussed below to
illustrate the first point.
4-17
-------
Table 4-3. COLD-SIDE ELECTROSTATIC PRECIPITATOR -
COST OF FINE PARTICULATE CONTROL
I
M
oo
Type
* i **
boiler
PC
CYC
Coal ash
characteristics ,
% of signifi-
cant constituent
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
0.6 sulfur
1.2 sulfur
3.0 sulfur
1.2 Na2O
6.0 Na20
1.2 Na20
6.0 Na2O
1.2 Na2O
6.0 Na,0
1.2 Na2O
6.0 Na2O
1.2 Na2O
6.0 Na20
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
0.6 sulfur
3.0 sulfur
1.2 sulfur
3.0 sulfur
Overall
mass
eff. ,
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
99.9
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
Frac. eff. on
particles in
0.2-0.4p
range , %
41.0
41.0
56.0
56.0
73.0
73.0
82.0
82.0
99.0
99.0
99.0
41.0
41.0
56.0
56.0
73.0
73.0
82.0
82.0
99.0
99.0
80.0
80.0
88.0
88.0
95.0
95.0
97.0
97,0
97.0
97.0
SCA required,
ft2/1000 acfm
Bitum.
195
108
265
140
420
208
520
284
'"
620
460
265
147
360
191
571
283
707
386
843
626
Subbit.
252
115
396
132
535
200
740
290
1050
455
Lignite
137
61
207
93
323
144
427
191
726
324
Cost 3 500 MW
Capital cost,
$AW
Bitum.
6.17
3.69
8.05
4.62
12.03
6.52
14.49
8.55
16.89
13.02
8.05
4.82
10.52
6.06
15.72
8.53,
18.94
11.18
22.07
17.03
Subbit.
7.71
3.90
11.43
4.39
14.85
6.30
19.70
8.71
26.73
12.90
Lignite
4.54
2.24
6.50
3.24
9.57
4.74
12.20
6.06
19.38
9.59
Ann. oper. cost,
mills/kWh
Bitum.
0.133
0.101
0.169
0.123
0.244
0.169
0.291
0.218
0.355
0.329
0.169
0.128
0.216
0.158
0.315
0.218
0.377
0.283
0.461
0.429
Subbit.
0.162
0.106
0.233
0.118
0.298
0.164
0.392
0.222
0.527
0.326
Lignite
0.112
0.067
0.154
0.090
0.221
0.125
0.279
0.157
0.439
0.242
PC - Pulverized coal; CYC - Cyclone.
-------
Table 4-4.
HOT-SIDE ELECTROSTATIC PRECIPITATOR - COST OF
FINE PARTICULATE CONTROL
*>.
I
V£>
Type
boiler
PC
CYC
Coal ash
characteristics.
% of signifi-
cant constituent
Fe,0,=5.0; Na,0=0.2
^2.0
0.2
2.0
0.2
2.0
0.2
2.0
0.2
2.0
Fe,O,=9.0; Na2O=0.2
2.0
0.2
2.0
0.2
2.0
0.2
2.0
0.2
2.0
Fe00,=5.0; Na.,O=0.2
23 2 2.0
0.2
2.0
0.2
2.0
0.2
2.0
0.2
2.0
Fe.0,=9.0; Na0O=0.2
23 2 2.0
0.2
2.0
0.2
2.0
0.2
2.0
0.2
2.0
Overall
mass
eff.,
*
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
93.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
95.0
95.0
97.5
97.5
99.0
99.0
99.5
99.5
99.9
99.9
Frac. eff. on
particles in
0.2-0.4u
range, %
41.0
41.0
56.0
56.0
73.0
73.0
82.0
82.0
99.0
99.0
41.0
41.0
56.0
56.0
73.0
73.0
82.0
82.0
99.0
99.0
56.0
56.0
69.0
69.0
83.0
83.0
89.0
89.0
97.0
97.0
56.0
56.0
69.0
69.0
83.0
83.0
89.0
89.0
97.0
97.0
SCA required,
ft2/1000 acfm
Western low-
sulfur coals
265
170
297
190
325
208
344
220
436
280
361
232
404
259
442
283
468
300
593
381
Eastern low-
sulfur coals
234
150
262
168
286
184
303
194
384
247
319
204
357
229
389
251
413
264
523
336
Cost J
Capital cost,
$/kW
Western
11.66
7.92
12.88
8.73
13.93
9.45
14.64
9.92
18.00
12.24
15.27
10.39
16.84
11.43
18.22
12.35
19.15
13.00
23.54
16.00
Eastern
10.47
7.11
11.55
7.84
12.47
8.49
13.11
8.89
16.11
10.97
13.71
9.29
15.12
10.27
16.30
11.13
17.17
11.63
21.09
14.34
a 500 MW
Ann. oper. cost,
mills/kwh
Western
0.273
0.193
0.299
0.211
0.323
0.227
0.338
0.237
0.412
0.288
0.352
0.247
0.386
0.270
0.417
0.291
0.437
0.305
0.535
0.372
Eastern
0.247
0.176
0.270
0.192
0.290
0.206
0.304
0.215
0.370
0.260
0.318
0.223
0.349
0.245
0.374
0.264
0.394
0.275
0.480
0.335
PC - Pulverized coal; CYC - Cyclone.
-------
Table 4-5. COSTS FOR OVERALL MASS AMD FRACTIONAL EFFICIENCIES OF
COLD-SIDE ESP ON BOILERS BURNING EASTERN BITUMINOUS
LOW-SULFUR (0.6%) COAL
Case
1
2
3
4
5
Boiler
type
PC
CYC
CYC
CYC
CYC
Overall mass
efficiency,
%
99.5
95.0
97.5
99.0
99.5
Fractional mass:
efficiency on
particles in,
0.2 - 0.4 micron
range, %
82
56
69
83
89
Capital
cost ,
$/kW
14.49
8.05
10.52
15.72
18.94
PC - Pulverized-coal-fired-boiler.
CYC - Cyclone-fired-boiler.
Table 4-6. COSTS FOR OVERALL MASS AND FRACTIONAL EFFICIENCIES OF
HOT-SIDE ESP ON BOILERS BURNING WESTERN SUBBITUMINOUS
LOW-SULFUR (0.6%) COAL
Case
1
2
3
4
5
Boiler
type
PC
CYC
CYC
CYC
CYC
Overall ma as
efficiency,
%
99.5
95.0
97.5
99.0
99.5
t
Fractional mass
efficiency on
particles in
0.2 - 0.4 micron
range , %
82
56
69
83
89
Capital
cost ,
$/kW
14.64
15.27
16,84
18.22
19.15
4-20
-------
Table 4-5 indicates thit the cost of maintaining a
fractional efficiency level of 82 percent for collection of
0.2- to 0.4-micron particles from a pulverized-coal-fired
boiler burning Eastern bituminous coal (0.6% S) is only
slightly higher than the cost of maintaining an 83 percent
fractional efficiency level for the same size particles with
a cyclone-fired boiler (refer to Cases 1 and 2) . However,
the overall mass efficiency must also be considered. When
both the fractional efficiency and the overall efficiency
criteria are considered (comparison of Case 1 with Case 5),
the capital costs show the cyclone to be 31 percent more
expensive than for the pulverized boiler. The cyclone
boiler, however, does show a higher collection efficiency in
the 0.2 to 0.4 micron range (89%). If both criteria are
satisfied with a hot-side electrostatic precipitator (Table
4-6 - Western subbituminous coal) the cost of the cyclone-
firing application (Case 5) is approximately 30 percent
higher than that of the pulverized-coal-firing application
(Case 1), but again is more efficient in collecting fine
particles.
The differences in size distribution characteristics of
fly ash from the boilers in question are responsible for
differences in fractional efficiency at a given overall mass
efficiency level. Coal type also affects the size distribu-
tion of particles at the outlet of the boiler. For example,
4-21
-------
size distribution data obtained from burning of a pulverized
hard coal may show larger mean and standard deviations than
those obtained from firing a pulverized soft coal. Also,
there is some evidence that fine particles often agglomerate
to some extent when passing through the air preheater.
Therefore, the fly ash size distribution at the inlet of a
hot-side precipitator may be different from that entering a
cold-side precipitator. The problem of quantifying the
particle size distribution and precipitator fractional
efficiency becomes even more complex and difficult when the
nonidealities of gas nonisoturbulence, gas sneakage, and
particle reentrainment are considered. It is not surpris-
ing, therefore, that reliable data are not easily obtain-
able. In any event, it is clear that both fractional and
overall efficiencies must be carefully weighed in the estab-
lishment of a fine particulate emissions standard.
The economic advantage of hot-side electrostatic pre-
cipitators is illustrated for a variety of cases in Table
4-7 and Table 4-8.
The percentage of Na20 in the coal affects the cost for
hot-side precipitators. Cases 2 and 4 in Table 4-7 and Case
2 in Table 4-8 show that hot-side electrostatic precipita-
tors have an economic advantage over cold-side precipitators
a
given the assumptions previously stated. Data on cyclone-
firing or Western subbituminous coal were not available.
4-22
-------
Table 4-7. COMPARISON OF COLD- AND HOT-SIDE ESP'S
ON BOILERS BURNING EASTERN BITUMINOUS LOW-SULFUR (0.6%) COAL
Case
1
2
3
4
Boiler
type
PC
PC
CYC
CYC
ESP
type
cold
hot
cold
hot
Overall
mass
eff.,
%
99.5
99.5
99.5
99.5
Fractional mass
efficiency on
particles in
0.2-0.4 micron
range, %
82
82
89
89
Capital cost @ 500 MW,
$/k]
% Na2O=0.2
14.49
13.11
18.94
17.17
f7
% Na2O=2.0
14.49
8.89
18.94
11.63
Table 4-8. COMPARISON OF COLD- AND HOT-SIDE ESP1S ON PC
BOILERS BURNING WESTERN SUBBITUMINOUS LOW-SULFUR (0.6%) COAL
Case
1
2
Boiler
type
PC
PC
ESP
type
cold
hot
Overall
mass
eff.,
%
99.5
99.5
Fractional mass
efficiency on
particles in
0.2-0.4 micron
range , %
82
82
Capital cost @ 500 MW,
$/kW
% Na2O=0.2
19.70
14.64
% Na20=2.0
19.70
9.92
4-23
-------
4.4 WET SCRUBBER COMPUTER MODELS
Thirty commercial-size scrubber modules operating in
the Western United States were installed specifically for
particulate removal. Selection of scrubbers over electro-
static precipitators in the past was motivated by the poor
performance of the precipitators on boilers firing low-
sulfur Western coals. These installations include the
following three classes of scrubbers:
1. Gas-Atomized Spray {Venturi) Scrubbers
2. Three-Stage TCA
3. High-Pressure Spray Scrubber
Available operating data have been summarized by Sondreal.
In spite of some of the problems that have become apparent
with the use of scrubbers over the last 5 or 6 years, it is
.?
still of interest to estimate the scrubber capabilities in
removing fine particles.
Design equations and the assumptions for formulation of
the models to predict fractional efficiency performance are
included in the following paragraphs.
4.4.1 Design Equations and Assumptions - Venturi Scrubber
Computer Model
Venturi scrubbers are well described in the available
7 8
literature. ' The particle collection process depends
4-24
-------
mainly upon the acceleration of the gas to provide impaction
and intimate contact between the particles and fine liquid
droplets generated as a result of gas atomization. The
condensation effect also plays an important role in the
effectiveness of the venturi scrubber. If the gas in the
reduced pressure region in the throat is fully saturated,
condensation will occur on the particles in the higher
pressure region of the diffuser. This is known as hetero-
geneous nucleation; it helps particle growth and also causes
agglomeration, which tends to enhance collection. Particle
collection mechanisms in the venturi scrubber have been
8 9 10
investigated by many researchers. ' '
The venturi model used in this study is based on in-
ertial impaction. It is assumed that the particles do not
grow during the collection process as a result of hetero-
geneous nucleation and condensation effects. The general
form of the expression for collection efficiency for parti-
cle size i can be written as:
Ei = 1 - exp(-KCL/G) «F±) (1)
where E. = Removal efficiency, fractional
K = Impaction correlational parameter (system
parameter)
L/G = Outlet liguid-to-gas ratio, (gal/1000
' actual ft3)
Y. = Inertial impaction parameter of particle
size grade, i
4-25
-------
Available experimental data have been used to develop a
correlation for inlet throat velocity, V in ft/sec, based
on AP (in. H00) and outlet L/G measurements.
AP
Vt -
5.23 X 10~6(L/G + 105)
(2)
Knowing the inlet throat velocity and measured outlet
L/G, the droplet diameter in microns can be calculated from
a modified form of an equation developed by Nukiyama and
11
Tanasawa.
L4KL/G)1'5 (3)
The system parameter K is determined by an iterative
procedure based on comparison of the actual measured overall
mass collection efficiency and that calculated from summing
the individual fractional efficiencies. For a given parti-
cle size the inertial impact ion parameter is defined below:
_0.85(CHpp)(Dp,2Vt
i y D
c
where C = Cunningham correction coefficient
:*
p = Particle specific gravity, (grams/cm )
D = Particle diameter, (microns)
A
p = Dynamic gas viscosity, {poise x 10 )
D = Droplet diameter, (microns)
C
4-26
-------
•>\ D
and C = 1 + =£- 1.23 + 0.41 exp(-0.44 JE) (5)
°P *
where A = Mean free path of gas molecules, (microns)
The value of K is modified during the course of itera-
tion to yield a closer match between measured and calculated
overall mass collection efficiencies for given input values
of L/G and AP. When the "optimum" value of K has been
found, it is inserted into the above equations to generate
the outlet particle size distribution and finally the frac-
tional penetration for the various particle sizes. It
should be noted that this is really an averaged system
parameter since it is not a function of any specific parti-
cle size.
4.4.2 Design Equations and Assumptions - UOP Three-Stage
TCA Scrubber
The design details of this moving-bed scrubber are
9 10
given in the literature. ' Inertial impaction and inter-
ception are the primary collection mechanisms. The UOP
design uses lightweight hollow plastic spheres, which
exhibit random motion with the formation of a turbulent
layer above the spheres as a result of the gas flow.
Based upon the theory of moving-bed scrubbers and
p
experimental data, Calvert recommends a semi-empirical
design equation of the form
4-27
-------
- exp [-2.45E6(U)3-3(U)'36K ]
where UT = Superficial liquid velocity, cm/sec
L
U_ = Superficial gas velocity, cm/sec
G
Z = Stage height, cm
d = Packing diameter (spherical, hollow
balls), cm
K = Inertia! parameter
., ~2
(6)
.
9yd
(7)
where
p = Dynamic gas viscosity, poise
D = Particle diameter, cm
Unfortunately, the values for IL, and U_ could not be
(j LI
obtained from the available operating data. Therefore, an
alternative approach was elected and is described in the
following paragraphs.
An alternative method of determining the fractional ef
ficiency of the TCA scrubber is to perform empirical cor-
relations of the form
± = f(Ap, L, D)
12 *
(8)
Statnick and Drehmel have published data on measured
fractional efficiency for a TCA scrubber under different
operating conditions. Regression analysis performed on
those data yields a best fit of the form
E± = 1 - K exp E-0.0222(L).6(Ap).85(D)1-5] (9)
, 4-28
-------
where Ap = Total pressure drop, in. HLO
D = Particle diameter, microns
K = System parameter
4.4.3 Design Equations and Assumptions^ - Krebs-Elbair
High-Pressure Spray Impingement~Scrubber"
In this design, liquid is atomized by some means other
than energy transferred from the gas being cleaned. There-
fore, these scrubbers are also called preformed spray
scrubbers. High-pressure spray nozzles are used to generate
high-velocity water droplets in the size range of 200 to 600
microns. In this particular design, droplets flow initially
in a concurrent fashion acting as a spray column, then hit
against a membrane to form a rebound zone at the membrane
surface. At the membrane the gas is suddenly accelerated,
the membrane itself simulating many linear venturi tubes,
which do further scrubbing.
Inertial impaction is the predominant mechanism of
particulate collection. Calculation of the collection ef-
ficiency of the device is based on the following assumptions;
a) Nozzle type and Ap across the nozzle
b) Opening of nozzle orifice, droplet size, and
droplet velocity
c) Opening area of the membrane
4-29
-------
d) Percent (fraction) of the droplets actually re-
bounding from the membrane, their size, and
velocity
e) Percent (fraction) of the droplets actually
passing through the membrane
f) Percent (fraction) of the droplets actually lost
at the membrane surface.
With the above assumptions, the Krebs-Elbair high-
pressure spray system could be looked upon as a hybrid
scrubber for which particulate collection can be split into
three components:
(1) Collection resulting from concurrent spray
(2) Collection resulting from countercurrent spray
(3) Collection resulting from the venturi effect
Mathematically, the total collection of particle size grade
i could be written as:
E± = 1 - exp [-K1Lfli°-5 - O.lK-jLY.^0'5 - 0.1K2L¥2i°-5] (10)
where the first two terms under the exponential indicate
penetration resulting from the concurrent spray zone and the
countercurrent rebound zone, respectively. The last term
represents the contribution resulting from the venturi
effect simulated by the membrane surface. The various
assumptions used in developing Equation (10) are as follows:
(i) The system parameters K^ and K2 (Kj_ for the con-
current spray zone and K2 for the counter current
(rebound) spray zone) are assumed to be the same-
This further implies that during the process of
rebounding there is no'-change in droplet size.
4-30
-------
(ii) In estimating the impaction parameter t^i' know~
ledge of the droplet velocity relative to that of
the gas is essential. It is assumed that the
droplets rebound with the same velocity as that of
the oncoming gas.
(iii) It is further assumed that only 10 percent of the
spray rebounds.
(iv) It is assumed that the opening area of the mem-
brane is 10 percent of the effective scrubber
cross section and that the water flow rate through
the membrane is 10 percent of the total water
flow. For computational purposes, the value of
both system parameters (K-, and K2) is assumed to
be 0.1, which is typical for most venturi scrubbers,
The process parameters for the Krebs-Elbair high-pressure
spray scrubber are assumed and are given below.
(i) Average gas velocity before the membrane = 10 fps
(ii) Spray nozzle type - whirljet nozzle
(iii) Spray nozzle pressure = 200 psi
(iv) Average droplet size = 280 ym
(v) Water flow rate per nozzle =6.52 gpm
(vi) Droplet velocity (assuming 1/8-inch orifice) = 170
fps
The above values and a typical inlet particle size
distribution from a pulverized-coal-fired boiler are used to
determine fractional efficiency values for specific L/G
measurements.
4.4.4 Percent Penetration As a Function of Particle Size
For Wet Scrubbers
Tables 4-9 through 4-12 show performances of the four
types of wet scrubbers for collection of particulate from
4-31
-------
coal-fired utility boilers as predicted by mathematical
models, and Figures 4-8 through 4-11 graphically show these
performances. Table 4-13 summarizes the relative predicted
performance of all scrubbers considered at particle sizes of
0.2, 0.5, and 1.0 micron. All particle sizes given with
reference to scrubbers are in terms of aerodynamic diameter
unless specifically noted.
Inlet particle size distribution information only was
available for the Montana-Dakota Flooded Disc, venturi
scrubber, and the Cherokee TCA scrubber. An inlet particle
size distribution (x = 12 ym, o = 3.8 pm) was assumed for
all of the scrubbers evaluated except for the Montana-Dakota
installation. Section 4.4.4.3 includes reasons for not
using particle size distribution from the Cherokee station
in the computer model predictions. Three other power sta-
tions (Arapahoe, Mohave, and Reid Gardner) were preceded by
a mechanical collector, precipitator, or both (see Table 2-9
for details), but no particle size data were available. Thus,
because of a lack in accurate particle size data, precise
comparison of the predicted scrubber fractional'efficiencies
is not possible.
The results of the model predictions within each scrub-
ber category are discussed in the next sections.
4-32
-------
Table 4-9. PREDICTED PERFORMANCE OF CHEMICO VENTURI SCRUBBERS IN
COLLECTION OF FINE PARTICLES
^"^\^^^ Utility and
^^-\^^ station
System ^"~"\^^
parameters ^~~~~---^^
^, %
Ap, in. H20
L/G, gal/1000 acf
Particle size,
microns
0.2
0.6
0.9
1.5
3.0
7.0
Arizona Public Service
(Four Corners)
99.2
28
9
Penetration, %
Calvert
Model
81.6
21.5
4.8
0.17
0.0
0.0
Research-Cottrell
Model
60.20
28.60
16.40
5.37
0.33
0.0
Pacific Power and Light
(Dave Johnston plant)
99.0
15
13
Penetration, %
Calvert
Model
86.1
30.0
7.5
0.33
0.0
0.0
Research-Cottrell
Model
63.80
33.00
20.10
7.52
0.64
0.0
to
u>
-------
100.0
10.0-
1..C -
0.1
T 1 1—I I I -I"
PACIFIC POWER 4 LIGHT
(DAVE JOHNSTON PLANT)
fi = 99.0*; AP - 15 1n. H?0;
L/6 - 13; K = 0.123
ARIZONA PUBLIC SERVICE-
(FOUR CORNERS)
n - 99.2*; AP - 28 1n. HjO;
1/6- 9; X » 0.139 c
I I I I I I I I I I I I I I I I I I
5 - 12, a - 3.B
(Inlet)
0.1
1.0 * 10,0
PARTICLE -SIZE, mterons
Figure 4—8. Predicted performance of venturi scrubbers
in removal of fine particulate.
4-34
-------
Table 4-10. PREDICTED PERFORMANCE OF RESEARCH-COTTRELL
FLOODED DISC SCRUBBER IN COLLECTION OF
FINE PARTICULATE
~~~ ---___^^ Utility and
"" -~—___^^ station
System • — -_____^^
parameters ~~~- — _______
"n, %
AP, in. H-0
L/G, gal/1000 acf
Particle size,
microns
i 0.2
Ul
01
0.6
0.9
1.5
3.0
7.0
•Montana-Dakota Utilities
(Lewis and Clark station, Unit 1)
96.0
12.3
11.8
Penetration, %
Calvert Model
89.0
•44.0
24.5
1.65
0.0
0.0
Research- Co ttrell Model
67.40
37.80
24.50
10.4
1.20
0.004
-------
100.0
J—I I I I I 11 1 1—I—I I I I
MONTANA-DAKOTA UTILITIES
(LEWIS AND CLARK STATION)
ft « 96*; AP - 12.3 1n. H^
L/6 • 11.8
10.0
§
1-4
i
1.0
0.7
I I I I I I
RESEARCH COTTRELL
MODEL (K - 0.125)
CALVERT MODEL
» * 3.1, o • 2.3
(Inlet)
0.1
r.O 10.0
PARTICLE SIZE, microns
TO
Figure 4-9. Predicted fine particulate performance of
flooded-disc scrubber at Montana-Dakota Utilities
Lewis and Clark Station.
4-36
-------
Table 4-11. 'PREDICTED PERFORMANCE OF UOP TCA SCRUBBERS IN
COLLECTION OF FINE PARTICULATE
^^
System
parameters
"n
AP,
L/G,
Utility and
^•\^^ statipn
, %
in. H^O
gal/1000 acf
Particle size,
microns
0.2
0.6
0.9
1.5
3.0
7.0
Public Service of Colorado
(Cherokee station)
95 - 97. 5a ,
10 - 15 (10)D
50 (40)c
Fractional
efficiency,
%
12.07
48.73
70.69
92.87
99.94
100.00
Penetration,
%
87.93
51.27
29.30
7.13
0.06
0.00
Public Service of Colorado
(Arapahoe station)
97. 5a .
10 - 15 (12)D
50 (40)c
Fractional
efficiency,
%
14.88
56.70
78.52
96.35
99.91
100.00
Penetration,
%
85.12
43.30
21.48
3.65
0.09
0.00
a Calculated overall mass efficiencies for the Cherokee and Arapahoe Stations are
98.71 and 99.0 percent, respectively.
Values in parentheses were selected from the ranges given for system pressure
drop. (See note c).
c Scrubber model utilizes an iterative procedure to determine the calculated over-
all mass efficiency and the model is sensitive only to L/G, AP, and r\. The_values
for L/G and AP were selected so as to give close agreement of the computed n to
the actual rj". The value "K" (iterative parameter) is selected based on the
scrubber system, ranging between 0.3 and 1.0 for the different scrubbers.
-------
100
80
60
50
40
30
20-
10-
2 6|
g 5
UJ
LU
a.
2
4
3
1.0-
.8
.6
.5
.4
.3
,2-
I I I
PUBLIC SERVICE OF COLORADO
(CHEROKEE STATION)
r\ = 98.71%; Ap - 10 in. H 0;
L/6 =40 2
PUBLIC SERVICE OF COLORADO
(ARAPAHOE STATION)
ii" = 992; Ap * 12 in. H20;
L/G = 40
x = 12, a = 3.8
(inlet)
i i i i
i i i i
i i i
.1 .2 .3 .4.5.6 .81.0 2 3 4 5 6 810
PARTICLE SIZE, microns
20 30 50 80100
Figure 4-10. Predicted performance of TCA scrubbers
on fine particulate.
4-38
-------
Table 4-12. PREDICTED PERFORMANCE OF KREBS-ELBAIR HIGH-PRESSURE
SPRAY SCRUBBER IN COLLECTION OF FINE PARTICULATE
^\
System
parameters
AP,
L/G,
Utility and
"~~~^^^ station
r\, %
in. H2O
gal/1000 acf
Particle size,
microns
0.2
0.6
0.9
1.5
3.0
7.0
Minnesota Power and Light
(Clay Boswell plant)
99.0
4
8
Fractional
efficiency,
%
29.98
65.67
79.89
93.09
99.52
100.00
Penetration,
%
70.02
34.33
20.11
6.91
0.48
0.00
Minnesota Power and Light
(Aurora plant)
98.0
4
8
Fractional
efficiency,
%
24.14
56.35
71.16
87.41
98.42
99.99
Penetration,
%
75.86
43.65
28.84
12.59
1.58
0.01
it*
i
-------
1.00
80
60
50
40
30
20
10
** 8
- 6
§ 5
i *
? 3
I'.O
.8
.6
,5
.4
.3
.2
.1
T 1 T
I I I
x = 12, a = 3.8
(inlet)
i I i i i
MINNESOTA POWER & LIGHT
(AURORA PLANT)
r\ « 98.0%; Ap = 4 in- M;
L/G = 8
-MINNESOTA POWER & LIGHT
(CLAY BOSWELL PLANT)
n - 99.0%; Ap =4 in. H20
.L/G = 8
i i i i i
.1 .2 .3.^.5.6.81.0 ;2 3 ,'4'S 6 8 10. 20 30.' 50 80100
PARTICLE SIZE, microns.
Figure 4-11. Predicted performance of high-pressure spray
scrubbers in removal of fine particulate.
4-40
-------
Table 4-13. PREDICTED PERFORMANCE OF WET SCRUBBERS IN
COLLECTION OF FINE PARTICULATE FROM COAL-FIRED UTILITY BOILERS
Scrubber type
Gas-atomized spray scrubbers
Research-Cottrell flood disc
Montana-Dakota Utilities (Calvert Model)
(Lewis and Clark station) (RC Model)
Chemico venturi
Pacific Power & Light (Calvert Model)
(Dave Johnston plant) (RC Model)
Arizona Public Service (Calvert Model)
(Four Corners plant) (RC Model)
High-pressure spray impingement Scrubbers
Krebs-Elbair high-pressure spray
Minnesota Power & Light
(Aurora plant)
Minnesota Power & Light
(Clay Boswell plant)
Moving-bed scrubbers
UOP, three- stage TCA scrubber
Public Service of Colorado
(Cherokee station)
Public Service of Colorado
(Arapahoe station)
Penetration, %
0.2 um
89
67.4
86.1
64
81.6
60
75
70
90
85
0.5 ym
55
44
42
42
33
36
52
44
60
52
1.0 ym
13
22
4.8
17
3
13
23.5
17
22.5
16
-------
4.4.4.1 Gas Atomized Spray Scrubbers - Figure 4-8 presents
Research Cottrell's (RC) predicted penetration vs. particle
size for the conventional venturi scrubbers at the Dave
Johnston and Four Corners Station and Figure 9 presents the
flooded disc venturi scrubber at the Montana-Dakota station.
Q
These predictions were compared with Calvert's Model,
which is also plotted in Figure 4-9 for comparison with the
RC model.
The cut diameter particle sizes* obtained for the three
scrubbers mentioned above are slightly higher using the
Calvert Model than for the RC Model. The Calvert Model also
shows 1) a sharper rise in penetration for particle sizes
below the cut diameter size, and 2) a more rapid decrease in
penetration for particle sizes above the cut diameter size,
as compared to the RC Model.
Variations in the RC and Calvert models could result
from the following: 1) use of an average correlational
impaction value, K, as an iterative value as opposed to the
use of an "F" factor as an iterative parameter in the Calvert
model (the "F" factor relates the nonuniformity of the
4
atomized liquid resulting in a difference in the liquid and
gas velocities, particle diameter, and the nature of the
particles), 2) use of the Nukiyama and Tanasawa droplet
Particle size at which penetration is 50 percent.
4-42
-------
diameter in the RC model as opposed to the Sauter mean
droplet diameter in the Calvert model, and 3) use of a
greater number of particle size intervals for the Calvert
model than for the RC model for the comparisons made in this
report. The greater the number of size intervals used, the
more precise the penetration will be when plotted on a
graph.
The Chemico venturi scrubber shows little improvement
in collection as a result of increased pressure drop (Figure
4-8). Increasing the pressure drop from 15 inches of water
at Dave Johnston to 28 inches of water at Four Corners con-
tributes relatively little to the overall collection. The
water requirements, however, decrease by about 70 percent.
The cut diameter predictions for the Dave Johnston
Station are approximately 0.40 micron with the RC Model and
0.44 micron with the Calvert Model (AP = 15 in. H20). For
the Four Corners Station the cut diameter predictions are
approximately 0.36 micron with the RC Model and 0.39 micron
with the Calvert Model (AP = 28 in. H20). As would be
expected from the venturi scrubber models, the flooded-disc
venturi scrubber at the Lewis and Clark Station, because of
its lower pressure drop, shows a higher cut diameter (0.42
micron at AP of 12.3 in H_0 using the RC model) than the
other conventional venturi scrubbers. Use of the Calvert
4-43
-------
Model for the Lewis and Clark Station yields a cut diameter
of approximately 0.54 micron.
4.4.4.2 High Pressure Sgray Scrubber - Operating data on
the Krebs-Elbair high-pressure spray impingement scrubber
indicate different degrees of collection for the same system
pressure drop and L/G values (Figure 4-11). The computer
model accounts for this variation by adjusting the system
parameter K, in equation (10). Various assumptions were
required in formulating the model for this scrubber, as
indicated in the design equations.
4.4.4.3 TCA Scrubbers - The predicted performance of the
TCA scrubber at the Valtnont Station of the Public Service of
Colorado appeared to be the best among the scrubbers under
study. However, its pressure drop of 15 in. water lies
outside of the limit for which the model was developed (AP *
12 in. H20). Therefore, no conclusions were drawn from this data.
The predicted performance of the TCA scrubbers at the
Cherokee and Arapahoe stations is shown in Figure 4-10.
Both the Cherokee and Arapahoe scrubbers were preceded by a
mechanical collector and a precipitator. The effect of
these preceding devices on the particle size distribution
was not evaluated in the model. Scrubber model values for
the Cherokee and Arapahoe stations indicate that the frac-
tional efficiencies in collection of submicron particles are
4-44
-------
extremely sensitive to system pressure drop and L/G values.
It is apparent that high rates of water circulation are
necessary to achieve greater collection of submicron parti-
cles.
The TCA scrubber models perform an iterative procedure
by selecting a value of the system parameter, K, to reflect
the particular features of the system. The input overall
mass efficiency is compared to that calculated from L/G and
Ap values. Since the model is sensitive only to those
parameters, and since both the Cherokee and Arapahoe sta-
tions have identical L/G and Ap values but different overall
mass efficiency levels, it is clear that some modification
of the input variables is required. To minimize the dis-
crepancy between the actual and calculated values of overall
mass efficiency, the values of L/G and Ap were modified
slightly, as shown in Table 4-11.
An attempt was also made to base predicted performance
of the Cherokee scrubber on actual test data for Ap, L/G,
and particle size distribution as measured in two separate
tests on the Cherokee scrubber in 1974 and 1975.
However, it was not possible to match the actual collection
efficiencies and the calculated efficiencies from the model
within the limits, of the system parameter, K.. This means
that for the Cherokee scrubber, the data upon which the
4-45
-------
model is based do not agree with actual TCA scrubber results
as measured in the above tests.
4.4.5 Comparison of Wet Scrubber Test Data and the
Computer Models
The validity of the assumptions underlying the perfor-
mance prediction models for the particulate wet scrubbers
can be determined only after testing the models against
experimental data under various operating conditions.
Data are available on a number of coal-fired boilers
utilizing venturi and TGA wet scrubbers for particulate
10 10 "I yi "ic
control. ' ' ' Unfortunately, in only one case,
(Cherokee Station) are predicted and actual results avail-
•v
able for the same scrubber.
Table 4-14 summarizes pertinent fractional efficiency
test data for two venturi and three TCA scrubbers on a
number of coal-fired boilers. Without making direct com-
parisons it can be seen that the test data demonstrate what
the scrubber models predict: a sharp rise in penetration
below a particle size of about 2 microns.
Figure 4-12 presents the test results of two venturi
scrubbers and one TCA scrubber from Table 4-14. The TVA-
Shawnee-TCA scrubber fractional efficiencies plotted in
Figure 4-12 show much lower penetrations through all size
ranges than the TVA-Shawnee or unidentified Chemico venturi
scrubber. At particle sizes between 0.3 and 1.0 micron, the
4-46
-------
Table 4-14.
SUMMARY OF FRACTIONAL EFFICIENCY TEST DATA FOR WET SCRUBBERS
OPERATING ON COAL-FIRED BOILERS
Location/ Company
1 . TVA-Shawnee
2. TVA-Shawnee
3. Coal-fired boiler
(360,000 acfm)
4 . Eublic Service of
Colorado-Cherokee
Station (1974)
5. Public Service of
Colorado - Cherokee
Station (1974)
Type of scrubber
UOP-TCA
"
Chemico venturi
Chemico venturi
UOP-TCA
UOP-TCAa
Particle
size,
microns
0.11
0.29
0.65
0.99
1.73
0.11
0.29
0.65
0.99
1.73
0.3
0.5
1.0
2.0
0.3
0.5
1.0
2.0
0.1
0.3
0.5
0.8
1.0
2.0
Percent
penetration
5.4
5.0
7.1
1.5
0.4
100
71
19
8
6
93
53
10
<1
90
30
10
2.0
5
63
70
54
44
15
Source
Reference 12
Reference 12
Reference 14
Reference 14
Based on data
from Reference
-------
100
80
60
50
40
30
20
10.
8
e
5
4
3
2
1.0
.8
.6
.5
.4
.3
.2
.1
I" I I I I I
Mill
T—i—i—r
KEY:
A TVA - SHAWNEE - UOP-TCA SCRUBBER
V TVA - SHAHNEE CHEH1CO VENTURI SCRUBBER
^ COAL FIRED BOILER - (360,000 acfm) - CHEMICO
^ VENTURI SCRUBBER
i I I i
lilt
.1
.3 .4 .5.6 .8 1.0 2 3 4 5 6 8 10
PARTICLE SIZE, microns
20 30 40 5060 80 100
Figure 4-12. Wet scrubber fractional efficiency test data from
various coal-fired boilers.
4-48
-------
TVA-Shawnee Chemico venturi scrubber shows the next lowest
penetration, followed by the unidentified venturi scrubber.
Thus, these data do not demonstrate the expected greater
performance of the venturi type scrubber. This does not
mean that the computer models are invalid. The computer
model predictions are based on assumed inlet particle size
distribution. The 360,000-acfm venturi scrubber is the only
test result in Figure 4-12 for which a particle size dis-
tribution is available (x = 38, a = 5). It is highly probable
that the size distributions occurring in the other two tests
%
are different from the ones assumed in the scrubber models.
Furthermore, when the scrubbers are designed as a part of a
hybrid system (i.e. in conjunction with mechanical collectors
and electrostatic precipitators), assumed values for inlet
particle size distribution may unfavorably bias the pre-
dicted results for any one of the scrubbers.
Test data for the same Cherokee station TCA scrubber
are available from both a 1974 and a 1975 study. The
penetrations determined in the 1975 study are significantly
higher than the 1974 test data, and higher than the penetra-
tions determined in the TVA-TCA scrubber study (Statnick and
Drehmel), as shown in Figure 4-12. Cascade impactor
results from the 1974 and 1975 Cherokee scrubber studies,
plus diffusion battery results from the 1975 Cherokee data,
4-49
-------
are presented in Figure 4-13. The predicted performance of
the TCA scrubber for the Cherokee station (from Figure
4-10), is also shown in Figure 4-13 for comparison with the
test results. It can be seen that the predicted performance
for the Cherokee station falls between the 1974 and 1975
test results. As mentioned in section 4.4.4.3 the predicted
performance is not based on actual operating conditions
because of the limits of the system parameter, K .
In comparing the 1974 and 1975 test data one would
expect that the smaller particle size distribution measured
in the 1974 data would shift the entire curve to the right
in relation to the 1975 data. However, the higher Ap of
the 1974 data combined with a higher overall efficiency
apparently more than offsets the effect of the smaller
particle size distribution and results in lower penetrations
for the 1974 data.
The 1975 Cherokee results in Figure 4-13 include dif-
fusion battery data and show a maximum penetration in the
0.2 to 0.5 micron range, similar to the fractional effi-
ciency relationship of precipitators; this is because of a
transition region between collection by inertial impaction,
which begins to lose its effect around 0.5 micron, and
collection by Brownian diffusion, which would account for
the decrease in penetration below the 0.2 to 0.5 micron
range.
4-50
-------
lOO
I
en
CHEROKEE TEST DATA - 1974
AVG. rf = 94.1; Ap = 11.8 in.
L/G = 50; x" = 3.0; a = 2.5
I I I I I I I -
CHEROKEE TEST DATA - 1975
AV6. in = 92.2%; Ap = 9.05 in.
L/G = NA; x" = 14.3 a = 7.4
PREDICTED CHEROKEE
PERFORMANCE
n = 98.71, Ap = 10 in. HgO
L/G = 40; 7 = 12; a = 3.8
i i i i i i i i i
I
.3 .4 .5.6.7.8 1.0
2 3 45678910 20
PARTICLE SIZE, microns
30 40 5060 80 100
Figure 4-13. Comparison of predicted and actual test results for
the Cherokee scrubber.
-------
Test data are not available for any of the other power
stations for which predictions were made.
In conclusion it is realized that because of a lack of
accurate particle size data, precise comparison of the wet
scrubber fractional efficiency prediction models is not
possible. However, in general the wet scrubber computer
models, show the performance of the venturi-type gas-atomized
spray scrubbers in fine-particle collection to be better
than that of the high-pressure spray impingement or the
three-stage TCA scrubber. Although presently available test
data on TCA and venturi scrubbers generally confirm the
scrubber computer models, the expected superior performance
of the venturi scrubbers is not confirmed in all cases.
4.5 FRACTIONAL/TOTAL MASS EFFICIENCY FOR FABRIC FILTERS
Efficiency data are available for fabric filters in
operation at two of the three utility plants. Fractional
and mass efficiency and mean particle size data are reported
in detail for the Nucla baghouse and for the Sunbury bag-
house. ' ' Apparently no performance tests have been
T8
conducted on the Holtwood baghouse. The available data on
particle size, collection efficiency, and the effects of
operating variables on penetration are presented for the
Nucla and Sunbury installations. Experimental data on
various types of fabric used at a pilot plant baghouse
4-52
-------
operation are also presented. A suitable theoretical model
is not available for prediction of fractional efficiencies
for fabric filters.
4.5.1. Nucla Baghouse
A total of 22 tests were run at the Nucla facility.
The baghouse operating conditions and the measured inlet/
outlet mass loadings are shown in Table 4-15. Mass effi-
ciency was calculated by use of the inlet and outlet mass
loadings determined by Method 5. Because the outlet mass
loading for run 22 was not obtained, no mass efficiency
value was determined but the particle size information from
that run was included in the sizing analysis.
The mean mass efficiency for all runs was 99.84 percent
with a standard deviation of 0.11. Results of two parti-
cular tests are noteworthy. Run 8 shows a mass efficiency
of over 99.98 percent, the highest reported for all runs.
This high collection efficiency is explained by the very
high inlet loadings observed that day. Combustion condi-
tions in the boiler were very poor for part of the run, and
the problem is attributed to the combustion system rather
than the fuel because the coal properties did not appear to
be atypical. The observation that the baghouse could
operate under such adverse conditions and still allow a
penetration of only 0.0016 gr/dscf is important.
4-53
-------
TABLE 4-15.
RESULTS OF PARTICULATE SAMPLING AT NUCLA-
16
Date
9/21/74
9/22/74
9/23/74
9/24/74
9/25/74
9/26/74
9/27/74
9/28/74
9/30/74
10/1/74
10/2/74
10/3/74
10/4/74
10/5/74
10/6/74
10/7/74
10/22/74
10/23/74
10/24/74
10/25/74
10/26/74
10/27/74
Run
1
2
3
4
5
6
7
8
9
"10
11
12
13
14
15
16
17
18
19
20
21
22
Inlet Mass Loading,
gr/dscf
Method
5
2.0759
2.1712
1.9753
1.7021
1.6768
1.7995
1.8516
11.4446
2.3878
1.6873
1.7422
2.1112
2.2693
1.7751
1.3572
2.1779
2.1098
2.0669
1.9828
1.7791
1.9502
2.0572
Andersen
Aa
0.4984
1.5078
1.4014
1.7092
1.4819
1.3426
1.3144
1.6248
1.6636
1.4206
1.0294
1.5900
1.8991
1.6593
2.4579
2.3232
1.8337
1.5351
1.8120
2.9943
1.5053
1.9528
Andersen
Ba
1.4610
1.7176
1.1793
1.4382
1.1600
1.9251
2.0818
1.9608
1.3540
1.4893
1.3091
2.0574
1.4318
1.6854
1.5909
-
1.6651
1 . 7094
1.6683
1.3352
1.7008
Outlet Mass Loading/
gr/dscf ••
Method
5
0.0044
0.0049
0.0045
0.0063
0.0042
0.0047
0.0045
0.0016
0.0016
0.0010
0.0015
0.0092
0.0040
0.0029
0.0007
0.0019
0.0022
0.0010
0.0015
0.0017
0.0015
•"
Andersen
North3
0.0101
0.0069
0.0034
0.0043
0.0031
0.0048
0.0033
0.0053
0.0021
0.0021
0.0035
0.0563
0.0034
0.0047
0.0039
0.0042
0.0025
0.0024
0.0030
0.0025
0.0028
0.0036
Andersen
Westa
0.0031
0.0034
0.0028
0.0021
0.0030
0.0051
0.0025
0.0015
0.0020
0.0034
0.0046
0.0796
0.0035
0.0154
0.0036
0.0037
0.0025
0.0022
0.0021
0.0025
0.0023
0.0035
Mass
Efficiency,
%
99.7880
99.7743
99.7722
99.6299
99.7495
99.7388
99.7570
99.9860
99.9330
99.9407
99.9139
99.5642
99.8237
99.8366
99.9484
99.9128
99.8957
99.9516
99.9244
99.9045
99.9231
™
Baghouse
Operation
Normal
Normal
Normal
Normal
Cont. cleaning
Cont. cleaning
Normal
Long repressure
Long repressure
Norma 1
No cleaning
No cleaning
Norma 1
No repressure
No repressure •
Normal
Normal
Long repressure
Normal
No shaking
No shaking
Normal
I
tn
Duplicate samplers for both inlet and outlet.
-------
Results of run 12 are interesting in that they show the
lowest efficiency and highest outlet loading of all tests.
Seven bags were replaced in the baghouse on that day, and
one might expect performance to improve with the removal of
failed bags. The bags that were replaced during run 12,
however, were in particularly bad shape, some having tears
several feet long. As a result, large amounts of fly ash
were deposited on the floor of the baghouse and were not
removed when the bags were replaced. It is theorized that
when that compartment came back on line the fly ash was
gradually reentrained and swept up the stack, causing the
extraordinarily high outlet concentrations.
Results of cascade impactor measurements show a mean
mass median diameter at the inlet of 18.4 microns, with a
standard deviation of 5.2; at the outlet of the baghouse the
mean mass median diameter was 8.8 microns, with a standard
deviation of 4.1. The outlet value of 8.8 microns appears
large for the reported mean mass efficiency of 99.84 percent
and suggests a possible leak in the system. This has not
been verified. A summary of the mass median diameter data
is shown in Table 4-16.
4-55
-------
TABLE 4-16.
16
RESULTS OF PARTICLE SIZING AT NUCLA-
Date
9/21/74
9/22/74
9/23/74
9/24/74
9/25/74
9/26/74
9/27/74
9/28/74
9/30/74
10/1/74
10/2/74
10/3/74
10/4/74
10/5/74
10/6/74
10/7/74
10/22/74
10/23/74
10/24/74
10/25/74
10/26/74
10/27/74
Inlet
Andersen A,a
mmd, um
37
17.6
21
16.5
20
16.5
17.1
16.2
18.2
19.0
16.5
18.1
12.5
18.6
1.2
21.0
17.3
18.8
15.8
••
22.0
19.5
Andersen B, a
mmd , Jim
••
28
20.5
21.5
23.4
20.8
18.3
15.5
11.6
15.5
16.0
14.2
27
20.7
16.0
16.0
-
15.3
17.2
18.0
18.0
21.7
Outlet
Andersen
Northa
mmd , Jim
10.8
8.8
18.1
14.9
15.3
10.1
8.6
.
9.7
6.1
7.2
0.80
14.6
10.2
9.5
7.7
4.1
7.0
4.4
6.3
5.8
7.4
Andersen
Westa
mmd , um
12.9
21
13.5
9.4
8,0
11.0
9o5
4.55
4.45
13.4
7.6
-
7.0
-
8.7
6.3
6.2
5.4
5.2
5.5
5.4
7.4
Duplicate samplers for both inlet and outlet.
4-56
-------
The fractional efficiency values for each run were
calculated from differential size distribution plots. The
differential particle size distributions were constructed in
19
Reference 16 in the manner described by Smith et al. The
concentrations of each of six particle diameters were
averaged for the two impactor runs at the inlet and outlet,
and the efficiency value calculated for each size. These
fractional efficiency or fractional penetration curves show
the performance of the baghouse as a function of particle
size. The results of all 22 fractional efficiency curves
have been combined in Figure 4-14 to give the median effi-
ciency/penetration over the range of 1 to 10 microns. The
result is a fairly smooth curve that tends toward higher
collection efficiencies for the larger particles and toward
higher penetration for the smaller particle sizes. Also
shown in Figure 4-14 is the range of observed efficiency/
penetration values for each size, but excluding the extreme
observations (highest and lowest). The wide bar indicates
the range of that half of the values nearest the median; the
narrow bar indicates the range of that half of the values
farthest from the median.
The effect of boiler load (air-to-cloth ratio) on
particulate penetration is reported for the Nucla facility
in a more recent report, as illustrated in Figure 4-15.
4-57
-------
o
IU.U
5.0
4.0
3.0
;2.0
1.0
0.9
0.8
0.7
0.6
.0.5
0,4
0.3
0.2
0.1
i
-
-
•
~
™"
: [
-
w
Jl
:h
-
m
i iii i i i i i
-
-
-
«
r
j
•
1
•
•
*
i i
m
MP» ~"
X
\
1
•
•
•
1
™
-
-
•
K
^
\
M
»
i
•
«
« —
i i i
7U. U
95.0
96.0
97.0
98.0
A
UJ
99.0 £
99.1 IT
99.2 lii
99.3
99.4
99.5
99.6
99.7
99.8
99.9
12 34 56 7 8 9 10 11 12 13 14
PARTICLE SIZE, microns
Figure 4-14. Median fractional efficiency for 22 tests
on Nucla baghouse.
-------
SYMBOL LOAD CLEANING
MW FREQUENCY
o
D
A
6
11
12
NONE
HOURLY
HOURLY-
CONTINUOUS
PRESSURE DROP
BETWEEN CLEANING
IN H20
3.0
3-4.5
3-4.5
fpr « 1 T
o
§•«
0.
~ .12
t .11
3
o 10
nl .1 V/
\ -09
UJ
t .08
0
W .07
1 >06
™ .05
:n
CD
§ 04
QL
* .03
| .02
§ .01
1 1 1
•z.
uj n
iliii
-
•
-
-
-
-
L
-
-
_
m
•
-
-
-
-
>k
-
•V
_
•
- 5 H
i i i i i
33. OU
•99.87
99.88
99.89
99.90
99.91
99.92
'99.93
99.94
99.95
99,96
$9.97
99.98
99.99
0.5
1.0
1.5
2.0
2.5
3.0
O
HH
LI-
AIR TO CLOTH RATIO ACFM/Fr
Figure 4-15. Penetration as a function of air-to-cloth ratio
with one standard deviation limit, Nucla baghouse.15
4-59
-------
With increasing load the baghouse cleaning cycle increased
in frequency; the pressure drop also increased. As indi-
cated at 6 MW, the baghouse operated during a full-day test
period without requiring cleaning, and the pressure drop was
nearly constant at 3 in. H2O. As load increased, cleaning
became more frequent. The large variation in the 12-MW data
is believed to be related to bag cleaning and to condition
of the filter cake.15
Reference 15 also presents penetration data for par-
ticle sizes from 0.1 to 10 microns. Measurement in the size
range of 0.01 to 1 micron were done with an Electrical Aero-
sol Size Analyzer (EASA), in the range 0.5 to 10 microns,
with cascade impactors. Results for an 11-MW load are shown
in Figure 4-16. The submicron tests were conducted between
bag cleaning cycles, whereas the impactor tests included at
least three cleaning cycles. The difference between the
EASA penetration curve and impactor penetration curve is
probably because of increase in emissions during cleaning.
The flat penetration of particles greater than 1.5
microns in Figure 4-16 is illustrative of particle "seepage"
through the bags. This "seepage" occurs after the baghouse
is cleaned and is a result of particles sifting through the
newly cleaned bag until a cake again forms and aids filtra-
tion. The increased penetration of the 0.01 micron par-
4-60
-------
1.0
CD
IE
0.01
0.001
;o.ot
SULFURIC ACID
NUCLEI
NOVEMBER 12, 1975
11 MW LOAD
.HOURLY CLEANING FREQUENCY
PRESSURE DROP 3-4.5 IN. H?0
• ELECTRICAL AEROSOL SIZE
ANALYZER
DCASCADE IMPACTOR
ONE STANDARD DEVIATION LIMITS
'PARTICLE DENSITY =2.0 g/em3
0.10 1.00
PARTICLE SIZE, microns
10.0
Figure 4-16. Fractional penetration through Nucla
baghouse (11-MW load).16
4-61
-------
ticle is believed to be the result of the formation of
sulfuric acid nuclei. The stack temperature was at 210°F,
which is below the acid dew point.
The penetration values obtained with cascade impactors
by Bradway and Cass (Figure 4-14) for the same baghouse
are about 10 times greater than those shown in Figure 4-16.
It is suspected that the former data were strongly influ-
enced by bag leakage.
The particle diameter fractional penetration for the
half-load of 6 MW is shown in Figure 4-17. During the test
day, the bags were not cleaned. The good match of the EASA
and cascade impactor penetrations was because of the lack of
bag cleaning cycles.
16
The earlier Nucla study also reports the effect of
several variables on particulate penetration. The list of
variables analyzed is shown in Table 4-17. Among these
variables, numbers 6, 7, 9, and 10 relate to baghouse op-
eration. Variable 6, number of shakes per cycle, was varied
only for two tests when the shaking part of the cleaning
cycle was eliminated. Variable 7 is a somewhat qualita-
tive assignment in that it attempts to account for the
excessive frequency of bag failures. The baghouse was
inspected periodically for broken bags, and nearly every
inspection resulted in some bag replacement.16 Because it
4-62
-------
1.0
0.1
oe
g 0.01
0.001
'0.
•ISULFURIC ACID NUCLEI
1
NOVEMBER 14, 197?
6 MW LOAD
NO CLEANING CYCLES
PRESSURE DROP 3.0 IN. HJD
O ELECTRICAL AEROSOL Sf2E ANALYZER
D CASCADE IMPACTOR
ONE STANDARD DEVIATION LIMITS
PARTICLE DENSITY - 2.0 g/cm3
1
0.10 1.00
PARTICLE SIZE, microns
;io.o
Figure 4-1-7. Fractional penetration through Nucla
baghouse (6-MW load).16
4-63
-------
Table 4-iy. LIST OF VARIABLES ANALYZED
IN NUCLA STUDY16
1. Inlet grain loading, gr/ft
3
2. Outlet grain loading, gr/ft
3. Coal moisture, %
4. Coal ash, %
5. Coal sulfur, %
6. Bag shakes per cleaning cycle
7. Days since baghouse inspection
8. Boiler steam load, 1000 Ib/hr
9. Repressure time, sec
10. Cleaning cycles per test
11. Efficiency, %
12. Penetration, %
4-64
-------
was impossible to determine when the bag failure had actually
occurred, each day was assigned the number equal to the
number of days since a baghouse inspection resulted in bag
replacement.
Variable 9, length of reverse flow, was normally 15
seconds. In three tests it was extended to 60 seconds, and
in two tests it was eliminated. Variable 10, number of
cleaning cycles during the test, was included because the
frequency of cleaning cannot be closely controlled. The
cleaning cycle is actuated when pressure drop across the bag
reaches 4 in. of water and hence is dependent upon the
quality of the coal, the quality of combustion in the boiler,
the flue gas flow rate, and other factors. In addition, two
tests were run in which the pressure transducer was bypassed
so that no cleaning took place; thus each compartment was
active for the entire 6-hour sampling period.
In two other tests the baghouse was forced to clean
continuously. As a result, 14 cleaning cycles occurred
during the test period and each compartment was active
during only 5 of the 6 hours of testing.
Multiple regression analysis of the variables in Table
4-17 shows that changes in the cleaning cycle had no statis-
tically significant effect on particle collection efficiency
and only the time since last replacement of failed bags had
a significant effect on penetration.
4-65
-------
4.5.2 Sunbury Baghouse
A total of 31 tests were run at the Sunbury installa-
tion. Table 4-18 shows the inlet and outlet particulate
mass concentrations determined by total mass and cascade
17
impactor sampling techniques. The particulate mass pen-
etration and emission rate for each run are also shown.
Mass penetration and the total mass sample outlet concen-
tration statistics for all 31 runs are presented in Table
4-19. These data show that the average particulate
penetration and mean outlet concentrations with new bags
were 1.7 times and 1.45 times greater, respectively, than
with used fabric.
Inlet and outlet mass median diameters (mmd) were also
measured using impactors for each run. Table 4-20 presents
the inlet and outlet mmd summaries for all 31 runs.
These data show that the mmd values for the filter effluents
are on the average lower than those for the inlet dust.
Excluding the two questionable mmd values, the average
outlet mmd is roughly 19 percent lower than that at the
filter inlet.
Fractional efficiency curves down to 1 micron for used
and new bags at Sunbury are also reported. These plots
are shown in Figures 4-18 and 4-19. The fractional effi-
ciencies of the new bags are slightly higher than those of
the used bags. This is not what would be expected based
4-66
-------
Table 4-18. RESULTS OF PARTICULATE SAMPLING AT
SUNBURY STEAM ELECTRIC STATION17
Run
no.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
IS
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Baghouse inlet
concentration! grains/dacf
Total mass
sampler
3.6296
2.6596
2.8062
4.1235
2.6851
2. 5243
3.1661
2.2977
2.4280
3.2936 •
2.6678
2.0891
2.6020
2.884$
2.6728
2.4403
2.5058
1.8291
2.8942
2.2016
1.6694
1.3822
3.2646
2.0503
3.0946
2.3859
1.3477
3.0022
2.0174
2.0843
2.2181
Impactor
run A
2.6154
2.2244
2.0680
1.0839
2.5708
1.6296
2.0869
2.S095
1.9984
2.0085
2.5278
1.5471
1.9184
1.4442
1.3356
2.80S6
1.9631
1.2430
1.2809
1.3857
2.2743
2.3328
1.7175
2.0914
1.6780
1.8363
1.8289
1.3270
1.6922
1.7849
2.5772
Impactor
run B
-
1.3184
2.2677
3.5096
1.3776
2.8180
2.1190
1.3616
1.9855
2.0120
2.1174
2.0761
2.5280
3.3717
1.3409
1.0743
1.9043
2.0925
1.9564
1.8968
1.3782
1.7426
1.4863
2.2034
1.6408
1.8807
1.8489
1.8423
1.8105
1.9178
2.3989
Impactor
run C
-
-
-
_
-
.
_
.
_
„
_
„
_
..
.
„
_
„
_
_
.
1.9390
1.8851
2.7331
2.4440
1.6942
1.8929
1.1209
2.1041
1.5965
2.8530
Baghouse outlet
concentration, grains/dscf
Total mass
sampler
0.0022
E
E
0.0013
0.0017
0.0014
0.0014
0.0014
0.0015
0.0016
0.0033
0.0017
0.0020
0.0015
0.0016
0.0013
0.0016
0.0013
0.0016
0.001B
0.0019
0.0031
0.0028
0.0029
0.0025
0.0022
0.0022
0.0022
0.0023
0.0020
0.0022
Impactor
A
0.0046
0.0272
0.0075
0.0059
0.0028°
0.0077
0.0029°
0.0024°
0.0020D
0.0014°
S
0.0018°
0.0040°
0.0018°
S
S
0.0026°
0.0019°
0.0020D
0.0024°
0.0032°
0.0016W
0.0014™
o.oois™
0.00191*
0.0033™
0.00021*
0.0009W
0.00121*
o.ooio"
0.0011™
Impactor
B
0.0051
0.0146
0.0084
0.0064
0.0025°
0.0060
P
0.0019°
0.0029°
S
L™
L«
o.ooio"
0.0021"
0.0004"
0.0019™
P°
P°
0.0002™
P°
0.0011™
0.0029°
0.0037°
0.0035°
0.0029°
0.0035°
0.0029°
0.0016°
0.0024°
0.0026°
0.0020°
Mass
penetration,
percent
0.06
-
-
0.03
0.06
0.06
0.04
0.06
0.06
0.05
0.12
0.08
0.08
0.05
0.06
0.05
0.06
0.07
0.06
0.08
0.11
0.22
0.09
0.14
0.08
0.09
0.16
0.07
0.11
0.10
0.10
Emission rate,
lba/106 Btu
0.0047
-
-
0.0028
0.0039
0.0031
0.0031
0.0031
0.0035
0.0041
0.0101
0.0044
0.0047
0.1)035
0.0037
0.0033
0.0038
0.0031
0.0037
0.0044
0.0044
0.0074
0.0063
0.0058
0.0056
0.0047
0.0051
0.0049
0.0054
0.0044
0.0047
a Calculated from the inlet and outlet total mass sampler concentrations.
Note: E - Excluded because of apparent vacuuming of the duct floor during sample collection.
D - Double substrates per stage.
p - Impactor with prefilter.
S - Substrates stuck together.
L - Substrates lost weight.
H - University of Washington impactor.
-------
Table 4-19. PENETRATION AND OUTLET CONCENTRATION
17
Runs
All, normal and abnormal;
new and used bags3
Normal
Normal
with used bags
with new bags
Penetration,
percent
Mean
0.08276
0.06889
Q',11667
Standard
deviation
0.03963
0.03018
0.05610
Outlet concentration,
grains/dscf
Mean
0.00195
0.00181
0.00262
Standard
deviation
0.00056
0.00063
0.00033
Does not include Huns 2 and 3, which were discounted because
of apparent vacuuming of the outlet duct floor.
4-68
-------
Table 4-20. INLET AND OUTLET MASS MEDIAN DIAMETERS
17
Runs
All, normal and abnormal;
new and used bags
Normal
Normal
with used bags
with new bags
Inlet mmd, um
Mean
6.9
7.1
7.0
Standard
deviation
2.5
2.7
2.3
Outlet mmd, um
Mean
6.3, (5.6a)
5.7
6.4, (4.9b)
Standard
deviation
4.3, (2.5a)
1.8
5.9, (2.2b)
a
Impactor A data for runs 25 and 26 excluded.
'impactor A data for run 25 excluded.
4-69
-------
IU
c
4
4h
"
2
1
0.8
0.6
0.5
0.4
** -0,3
ar
i 0.2
i
s
* 0.1
0.08
0.06
0.05
0.04
0.03
0.02
0.01
i i i i i i i i i i i i i
©NORMAL RUNS EXCEPT THOSE WITH ONE SET OF SUBSTRATES
Q NORMAL RUNS WITH ONE SET OF SUBSTRATES
A ABNORMAL RUNS EXCEPT THOSE WITH ONE SET OF SUBSTRATES
X ABNORMAL RUNS WITH ONE SET OF SUBSTRATES
CURVE BASED ON AVERAGE OF ALL USED BAG RUNS
CURVE BASED ON AVERAGE OF ALL RUNS EXCEPT THOSE WITH ONE
SET OF SUBSTRATES AND RUN 16
NOTE: CURVES ARE BELIEVED TO BE BIASED TOWARD LOWER
REMOVAL EFFICIENCY FOR 8 m AND LARGER PARTICLES
_ BECAUSE OF USE OF A CYCLONE PRECOLLECTOR ON THE
Q INLET SAMPLER.
CD
E)
B @ X
B B
B
I O B -
A ^ : n
- Q 6 s
- . p Q Q < --* 5
* x B Sf A A
rt ' 7k ®
- \g ^--$'' A ^J§^^*^S
f ©X. ° J^^"^ Q
£^ ^ ****^!lj /\
©A
- Q -
A © A
- A © A -
-A -
©
*• «••
A
A
1 A 1 A 1 A 1 A 1 1 t 1 1
3U.W
95.0
96.0
A ••. f*
97.0
98.0
99.0
99.2
99.4
99.5
99.6
99.7
99.8
99.90
99.92
99.94
99.95
99.96
99.97
99.98
99.99
u
1 2 34 56 78 9 10 11 12 13 14
PARTICLE SIZE, microns
Figure 4-18. Removal efficiency as a function of particle
size for runs with used bags, Sunbury baghouse.
4-70
-------
, i.o
0.9
0.8
0.7
0.6
0.5
0.4
,0.3
,0.2
i,
*
|
£ 0,1
£ 0.09
g 0.08
°- 0.07
0.06
'0.05
0.04
0.03
0.02
_^^ % V mm^
0 01
%/ • ^/ 1
(
1 1 1 1 1 1 1 1 1 r
-
-
_
-
© © -
" A
A
— —
& 0
A © © °
- 0* A ~ ^-A
A % \$ * /7\
0 \8 ° x©x'
© \ © fi x''§ ©
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X>><^—- ••^**^ A
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-
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-
0.NORMAL RUNS
" A -ABNORMAL RUNS
— niDUF RAcrn OM AUPDArr np AI i NFUI RAA RIIN^ ~
— l/UKVt DnotU UIN MVtKnbt Ur MLL INtW DMu KUNi
'NOTE: CURVES ARE BELIEVED TO BE BIASED TOWARD
LOWER REMOVAL EFFICIENCY FOR 8 m AND
LARGER PARTICLES BECAUSE OF USE OF A
CYCLONE PRECOLLECTOR ON THE INLET
SAMPLER.
i i i i i i i i i i i i i — _ i
) 1 2 3 4. 5 6 7 8 9 10 11 12 13 1
99.0
99.1
^9.2
99.3
99.4
99.5
99.6
,99-7
99.8;
'
**.
^.90 g
99. 9t S
99.92 %
99.93 t
99.94
99.95
19.96
'99.97
99.98
99.99
4
PARTICLE SIZE, microns
Figure 4-19. Removal efficiency as a function of particle
size for runs with new bags, Sunbury baghouse.
4-71
-------
upon the higher mass efficiencies determined for used bags.
Reference 17 indicates that this difference might have been
caused by problems with the Andersen impactor substrate.
Furthermore, it is reported that the curves in Figure 4-18
and 4-19 are somewhat distorted for the larger particle
sizes because of the use of the Andersen cyclone precollec-
tor at the baghouse inlet.
Apparent collection efficiency by particle size for the
size range 0.1 to 10 microns is shown in Figure 4-20. This
figure shows a nearly uniform, high reduction of particles
entering the system. All sizes in the impactor range are
collected with better than 99 percent efficiency.
The Sunbury study also investigated the effects on
particle penetration or outlet mass concentration of alter-
ing such operating parameters as ash and sulfur content of
coal, boiler steam flow, and number of compartments in
service.• Tests on used bags showed no significant effect of
these parameters. Significant differences were observed,
however, when results obtained with new bags were compared
with those from used bags. With new bags, particulate
penetration and outlet mass concentration were most depend-
ent upon inlet mass concentration and pressure drop across
the baghouse. With used bags* moisture content of the fuel
and the baghouse face velocity had the most significant
effects.17
4-72
-------
I
-«J
CO
yy.yy
99.9
99
95
90
«
E 50
3
-t
"•»
i
LJ
j;
ij
L 10
5
1
0.1
n m
1 1 1 1 M 1 I 1 1 1 1 1 1 II 1 1 1 1 1 1 II
r i
— —
— —
~ FILTRATION VELOCITY = 2.0 ft/min ~
— (1.0 cm/sec) —
~~ OUTLET LOADING = 0.0017 grains/DSCF —
(0.0039 grams/m3)
— —
E ^ "^-^^^
i i i i i 1 1 1 i I i i i 1 1 1 i i i M I II
U.UI
S S w " °
* EFFICIENCY, %
o
o
90 3
95 8
99
99.9
QQ.QQ
0.01
0.1 1.0
PARTICLE SIZE, microns
10.0
Figure 4-20. Baghouse performance at Sunbury Steam Electric Station.
17
-------
4.5.3 Pilot Scale Investigation of Fractional Efficiency
of Fabric Filters on Coal-Fired Industrial Boilers
The fractional efficiency of five different fabrics was
determined on a coal-fired boiler at Kerr Industries by
McKenna et al. The fabrics tested were Nomex felt,
Teflon felt, Gore-Tex, and Dralon-T. Fractional efficiency
was determined using an Andersen inertial impactor for the
four filter media at three air/cloth ratios.
Although data of this type are interesting, the results
are experimental and should not be compared with actual
fabric filter efficiency under normal operating conditions
of a utility coal-fired boiler. Bags used on utility
boilers are made of fiberglass; none of the bags tested here
are of fiberglass construction. In addition, many of the
air/cloth ratios used in the pilot plant tests are con-
siderably higher than those used on the fabric filters now
in use on coal-fired utility boilers. One of the fabrics
(Gore-Tex) has a different filtration mechanism than other
fabrics, called laminate filtration.
It should also be noted that penetration figures for
the pilot plant are much higher than Sunbury or Nucla,
partly because inlet loading is much lower.
Teflon Felt - Style 2663
Figure 4-21 presents collection efficiency versus
particle size for Teflon felt - Style 2663. The curves at
4-74
-------
100
80
60
40
1.0
0.8
0.6
0.4
0.3
A/C RATIO
O 5.1/1
O 8.4/1
i i
CASE: TEELON FELT, STYLE 2663 -
J L
0.1 0.2 0.4 0.6 0.8 1.0 2
PARTICLE SIZE, microns
8 10
Figure 4-21. Penetration•vs. particle diameter,
Teflon felt style 2663.20
4-75
-------
each A/C ratio all show the same general trend, with the
curve sloping downward to the right indicating less pen-
etration of the larger particles. Two of the curves indi-
cate some leveling or decrease of penetration for the very
small fractions. This improved collection of the finest
fractions is also present and, in some cases, even more
pronounced in the data for the other media. For the Teflon,
an increase in A/C ratio generally resulted in an increase
in outlet loadings. For the smaller size fractions, the
curve does appear to flatten above an A/C ratio of about 8.
Gore-Tex/Nomex
Figure 4-22 illustrates collection efficiency versus
particle size for Gore-Tex/Nomex. These curves indicate an
increase in penetration as the fractions decrease from 10 to
0.5 micron. Below 0.5 micron, there is a sharp decrease in
penetration for all three A/C ratios. The performance of
Gore-Tex on submicron particles seems essentially the same
at all three A/C levels. As with the Teflon felt, the
largest particle size fraction, i.e. the total of all sizes
greater than 9.35 ym, is most sensitive to increases in A/C
ratio, and an increase in velocity results in an increase in
the outlet concentration. One unresolved problem with the
Gore-Tex bags, however, was that of durability.
4-76
-------
100
80
60
40
20
§ 8.0|-
>—i
| 6,
UJ
£ 4.0
2.0
1.0
0.8
0.6
0.4h
0.3
1 1 T
FILTER MEDIA: GORE-TEX/NOMEX
KEY:
A/CRATIOS
O.3.2/1
Oe.i/i
[D8.8/1
i i i
0.1 0.2 0.4 0.6 0.8 1.0 2
PARTICLE SIZE, microns
6 8 10
Figure 4-22. Penetration vs. particle diameter,
Gore-Tex/Nomex.20
4-77
-------
Dralon-T
The collection efficiency versus particle size for
Dralon-T is illustrated in Figure 4-23. Dralon-T was found
to exhibit greater filtering capabilities as the A/C ratio
was increased.
Nomex Felt
The efficiency of Nomex felt vs. particle size is shown
in Figure 4-24. Again, these curves show a higher effi-
ciency for the larger particles and indicate a significant
decrease in penetration of the two smallest fractions. When
compared with the other bag materials, Nomex was considered
to provide the best filtering efficiency.
McKenna et al. also studied the effect of duration and
volume of cleaning air on particle size efficiency, clean-
down, and pressure drop, using Nomex felt as the filter
medium. They found that higher collection efficiencies were
possible when the reverse air fan was not employed and that
varying the volume of reverse air (once in operation) has
little effect on overall efficiency. They also found that
A/C ratio is the key parameter in predicting baghouse effi-
ciency. Their data showed an increase in outlet loading
with increasing velocity for the three larger fractions,
while the outlet loading for the smallest fraction did not
seem to increase above an A/C ratio of 6.
4-78
-------
100
80
60
40
20
« 10.
•\
2 8.0
I 6.0
LU
UJ
4.0
2.0
1.0
0.8
0.5
n 1 1—i—i—rr~r
FILTER MEDIA: DRALON T
KEY:
A/C RATIOS
O 3.1/1
O 6.1/1
D 8.9/1
0.1 0.2 0.4 0.6 1.0 2
PARTICLE SIZE, microns
4 6 8 10
Figure 4-23. Penetration vs. particle diameter,
Dralon-T.20
4-79
-------
20
10
8.0
6.0
4.0
o 2.0
UJ
0- 1.0
0.8
0.6
0.4
0.2
0.1
I i i i r i i i i i i >
FILTER MEDIA: NOMEX FELT
KEY:
A/C RATIOS
O 3/1
O 6/1
D 8.5/1
I i i
0.1 0.2 0.4 0.6 0.8 2
PARTICLE SIZE, microns
6 8 10
Figure 4-24. Penetration vs. particle diameter,
Nomex felt .'20
4-80
-------
REFERENCES FOR TABLE 4-1
Case
1 Tests conducted by MRI 8/15/74 - 8/24/74 TVA, Widows
Creek Station, Unit 5. Bridgeport, Tennessee. Re-
ference: EPA-650/2-75-066.
2 Tests conducted by MRI, Union Electric, Meramec Plant.
St. Louis, Missouri.
3 Private Communication
4 Private Communication
5 Catalytic Oxidation Precipitator Performance at the
Wood River Power Station. Final Report to Mitre Cor-
poration, McLean, Virginia. Prepared by SRI, Birmingham,
Alabama. SORI-EAS-74-009 (3155-IF). March 12, 1974.
p. 3.
6 Fractional Efficiency of a Utility Boiler Baghouse,
Nucla Generating Plant. Prepared for EPA by Robert M.
Bradway and Reed W. Cass, GCA/Technology Division.
Bedford, Massachusetts. August 1975.
7 Private Report, Research-Cottrell, Inc.
8 Ref. 7
9 Ref. 7
10 Iowa Public Service/George Neal (Different source from
Ref. 7).
11 Private Report, Research-Cottrell, Inc.
12 Private Report, Research-Cottrell, Inc.
13 Nichols, G.B., and J.D. McCain. Particulate Collection
Efficiency Measurements on Three Electrostatic Precip-
itator s. Prepared by SRI for M.W. Kellogg Company.
EPA-600/2-75-056. October 1975.
14 Ref. 13
4-81
-------
REFERENCES - SECTION 4.0
1. Atmospheric Emissions from Coal Combustion: An Inven-
tory Guide. Public Health Service Pub. No. 999-AP-24.
1966.
2. Feldman, P.L. Effects of Particle Size Distribution on
the Performance of Electrostatic Precipitators. Re—
search-Cottrell, Inc. Bound Brook, New Jersey. Pre-
sented at the 68th Annual Meeting of the Air Pollution
Control Association. June 15-20, 1975; No. 75-02-3.
3. Nichols, G.B., and J.D. McCain, Particulate Collection
Efficiency Measurements on Three Electrostatic Precip-
itators. Souther Research Institute. EPA-600/2-74-
056. October 1975.
4. Jamgochian, E.M., et al.. Test Evaluation of Cat-Ox
High-Efficiency Electrostatic Precipiator. The Mitre
Corporation. EPA-600/2-75-037. August 1975.
5. Sondreal, E.A., and P.H. Tufte. Scrubber Developments
in the West. U.S. ERDA, Grand Forks Energy Research
Center. Grand Forks, North Dakota. 1975.
6. Mcllvaine Electrostatic Precipitator Newsletter. April
20, 1976.
7. The Mcllvaine Scrubber Manual, Volume I. The Mcllvaine
Co. 1974.
8. Wet Scrubber System Study, Volume I, Scrubber Handbook.
APT, Inc. PB213-016. July 1972.
9. Johnstone, H.F., R.B. Field, and M.C. Tassler. Ind.
Engng. Chem., Vol. 46. 1954. p. 1601.
10. Johnstone, H.F., and P.O. Eckman. Ind. Engng. Chem.,
Vol. 43. 1951. p. 1358.
11. Nukiyama, S., and Y. Tanasawa. Trans. Coc. Mech.
Engrs., Japan, Vol. 5. 1939. pp. 62-68.
4-82
-------
12. Statnick, R.M., and D.C. Drehmel. Fine Particle Con-
trol Using Sulfur Oxide Scrubbers. Presented at the
67th Annual Meeting of the APCA, Denver, Colorado.
Paper #74-231. June 9-13, 1974.
13. Calvert, S., N.C. Jhaveri, and C. Yung. Fine Particle
Scrubber Performance. EPA-650/2-74-093. October 1974.
14. Abbott, J.A., and D.C. Drehmel, Control of Fine Parti-
cle Emissions. Environmental Protection Agency, Re-
search Triangle Park, N.C. Chemical Engineering Pro-
gress. December 1976.
15. Symposium of Particulate Control in Energy Processes.
EPA-600/7-76-010. September 1976.
16. Bradway, R.W., and R.W. Cass. Fractional Efficiency of
a Utility Boiler Baghouse, Nucla Generating Plant.
NTIS Document No. PB 245541. August 1975.
17. Cass, R.W., and R.M. Bradway. Fractional Efficiency of
a Utility Boiler Baghouse—Sunbury Steam Electric Sta-
tions. EPA Report No. EPA-600/2-76-077a. March 1976.
18. Private Communication with R.C. Carr of EPRI on April
21, 1976.
19. Smith, W.B., K.M. Gushing, and J.D. McCain. Particu-
late Sizing Techniques for Control Device Evaluation.
Southern Research Institute. EPA-650/2-74-102.
October 1974.
20. McKenna, J.D., J.C. Mycock, and W.O. Lipscomb. Applying
Fabric Filtration to Coal-Firing Industrial Boilers - A
Pilot Scale Investigation. EPA Report No. EPA-650/2-
74-048a. August 1975.
4-83
-------
5.0 CONCLUSIONS
Particulate emissions from coal-fired utility boilers
have historically been controlled by electrostatic precipi-
tators, but wet scrubbers and fabric filters have also
recently been utilized for this purpose. Some advantages
and disadvantages of each type of control device are sum-
marized in Tables 5-1 through 5-3.
It is likely that precipitators will remain the pre-
dominant device for controlling particulate emissions from
coal-fired utility boilers because, when well-designed, they
offer high reliability and low operating costs. However,
each application must be reviewed on a case-by-case basis.
Low-sulfur coal, which presents the greatest design problems
for precipitators, will be consumed to a much greater extent
in the future; and when this occurs, utilities will most
likely consider a wet scrubber or fabric filter since these
control devices are less sensitive to low-sulfur coal.
5.1 DESIGN PRACTICES
The design of precipitators has been refined consider-
ably in the past few years to meet increasingly stringent
particulate emission regulations. Using the current design
5-1
-------
Table 5-1. ADVANTAGES AND DISADVANTAGES OF USING PRECIPITATORS ON COAL-
FIRED UTILITY BOILERS
Control device
Electrostatic
precipitator
to
Advantages
1) Can be designed to provide high
collection efficiency for all
sizes of particles from submicron
to the largest present; new designs
can meet stringent particulate reg-
ulations .
2) Economical in operation because
of low internal power requirements
and inherently low draft loss; high
reliability.
3) Flexible in gas temperature used,
ranging from as low as 200°F to as
high as 800°F.
4) Long useful life, if properly
maintained.
5) No water pollution potential.
6) Extensive history of application.
Di sadvantages
1) High resistivity of low-sulfur coal
fly ash degrades performance of cold
precipitator not designed for this
type of fuel.
2) Discharge wire breakage, ash hopper
plugging are potential maintenance
problemr.
3) Efficiency is sensitive to change in
ash characteristics.
4) Potential explosion and fire problems
during start-up because of high
voltage sparking.
5) High-voltage hazards to personnel.
-------
Table 5-2. ADVANTAGES AND DISADVANTAGES OF USING WET SCRUBBERS
ON COAL-FIRED UTILITY BOILERS
Control device
Wet scrubber
en
I
co
Advantages
1) Smaller space requirements than
precipitator or fabric filter.
2) Not affected by high resistivity
associated with low-sulfur coal
fly ash; relatively insensitive to
coal chemical composition and
variations in gas temperature.
3) No high-voltage hazard.
Disadvantages
1) Collection efficiency decreases
rapidly with decreasing particle size.
2) Maintenance costs are higher than
for precipitators and fabric filters.
(Corrosion, scaling, plugging)
3) Water pollution control required
for scrubber effluent.
4) Greater pressure drop and resulting
higher power demand needed for high
efficiency.
-------
Table 5-3. ADVANTAGES AND DISADVANTAGES OF USING FABRIC FILTERS
ON COAL-FIRED UTILITY BOILERS
Control device
Advantages
Disadvantages
Fabric filter
1) Collection efficiency essentially
independent of sulfur content in
coal.
2) High overall mass and fractional
efficiency. (99 + %)
3) Collection efficiency and pressure
drop are relatively unaffected by
changes in inlet grain loadings for
continuously cleaned filters.
4) No water pollution potential.
5} Corrosion is not a problem, with
bags
6) No high-voltage hazard, thus sim-
plifying repairs.
1) Higher pressure drop than ESP result-
ing in higher energy consumption.
2) Fabric life is difficult to estimate;
may be shortened in the presence of
acid or alkaline particles.
3) Low air-tc-cloth ratios require
large amounts of space (70 ft^/MW), at
A/C ratio of 2.5. However, as coal
sulfur content decreases, sizes of
fabric filters and precipitators begin
to equalize.
4) Condensation of moisture may cause
crusty deposits or plugging of the
fabric or require special additives.
-------
practices discussed in Section 2.0, a precipitator can be
more precisely tailored to its specific application. The
use of the Matts-Ohnfeldt modified migration velocity (w, ),
is an improvement over the conventional Deutsch Anderson
migration velocity (w), which is no longer adequate to meet
current demands for efficiencies well in excess of 98 per-
cent. Once the particle size distribution for a given
application is known, w, can be treated as a constant; w
cannot be treated as such. American and foreign manufac-
turers have used the w, concept in sizing precipitators.
The Jim Bridger Power Station in Wyoming is a recent example
where the w, concept was used successfully to help size a
precipitator for use with low-sulfur coal.
Increased use of other procedures such as combustor
tests and pilot scale precipitators also help in the sizing
of precipitators, especially where low-sulfur coal is to be
used.
Increased sectionalization, i.e., a greater number of
independent electrical sections in modern precipitators, is
another major design improvement since it substantially
improves on-stream reliability. Automatic controls for
power input also assist in assuring reliable performance.
Reported operating data from Sondreal and Tute on
particulate scrubbers in the western U.S. have shown overall
5-5
-------
mass collection efficiencies, ranging from 70 to 99.75
2
percent, although Green reports lower overall mass effici-
encies on some of the same installations as reference 1.
No clear trend, however, emerges from available test data
as to which type of scrubber is the best for use in the
collection of fly ash. Applications of scrubbers for
collection of fly ash have been limited for the most part to
low sulfur coal, sometimes in conjunction with an SO_
scrubber. To date, operation and maintenance costs of
particulate scrubbers have been higher than precipitators or
fabric filters, and utilities have placed less emphasis on
their use for particulate control. The high maintenance
costs are caused by corrosion, scaling, and plugging of
equipment.
j
The design of fabric filters for utility use does not
represent a breakthrough in technology, but rather a refine-
ment of the basic design procedures used in other indus-
tries. Existing fabric filters on utility boilers have
shown excellent overall mass collection efficiencies.
The present size of fabric filters required for in-
stallation on large coal-fired utility boilers (approxi-
2
mately 70 ft area/MW) may present a problem, where space is
at a premium. This size could be reduced if air-to-cloth
ratios in the baghouses were increased. Innovations such as
5-6
-------
pulse-jet cleaning (cleaning with periodic bursts of com-
pressed air) may allow this increase in the air-to-cloth-
ratio in baghouses. Also, changes in baghouse construction
such as utilizing suspended bags attached to a tube sheet
will allow changing entire sets of bags without entering the
chamber. This type of modification will reduce the number
of internal walkways and total area requirements for the
baghouse.
Another design problem that requires attention is the
vena contracta effect which occurs when fly ash enters the
filter through a hole in the cell plate. The vena contracta
effect impacts fly ash at relatively high velocity against
the filter surface and rapidly abrades it immediately fol-
lowing the mouth of the filter. One utility that operates a
baghouse solved this design problem by installing gas
straighteners, called "thimbles", at the inlet of the bags.
Improved filtration media are also being developed to
supplement fiberglass bags.
Thus, it appears that design improvements and modifica-
tions to make fabric filters smaller, more reliable, and
easier to maintain are occurring fairly rapidly.
5.2 OPERATION AND MAINTENANCE
The collection efficiency of particulate control sys-
tems degrades rapidly, especially in the fine-particle
5-7
-------
range, when strict maintenance and operating procedures are
not followed. However, more study is needed on the quan-
titative relationship between malfunctions resulting from
neglect or improper maintenance and the degradation in
efficiency of the control device. For particulate scrubbers
and fabric filters especially, a detailed handbook of main-
tenance procedures and troubleshooting tips would be useful
for utility operators who are responsible for maintaining
these control devices.
5.3 FRACTIONAL EFFICIENCY RELATIONSHIPS
Precipitators and fabric filters are highly efficient
collectors of submicron particles, while the collection
efficiency of scrubbers decreases rapidly with decreasing
particles size.
More fractional collection efficiency test data are
available for precipitators and scrubbers than for fabric
filters, and the tested data generally confirm predicted
efficiencies of computer models for precipitators and scrub-
bers. Test data show that precipitators can effectively
remove fine particles under favorable conditions. Overall
collection efficiencies can be greater than 99.5 percent,
and the efficiency for any particle size can be greater than
90 percent. Particles smaller than 0.1 micron can be col-
lected with efficiencies greater than 99 percent. Test data
5-8
-------
for particulate scrubbers on coal fired boilers usually show
a sharp decrease in efficiency below a a particle size of
micron, but the magnitude of the efficiency drop varies
greatly, (from approximately 5% to 94%) as shown in section
4.4.5, Table 4-13. Existing fabric filter systems operating
at an air-to-cloth ratio of 1 to 2 or less can collect 99+
percent of the particles from less than 0.1 micron to 10
microns in size.
Precipitators show a minimum in collection efficiency
in the particle size range of 0.2 to 0.4 micron, while
available data for fabric filters show a more uniform col-
lection efficiency in the submicron particle size range.
The collection efficiency of scrubbers declines to about the
0.2 to 0.5 micron range, the limit of collection by inertial
impaction. Below the 0.2 to 0.5 micron range, the effi-
ciency usually increases because of diffusion effects.
However, scrubbers are least effective in the collection of
submicron particles.
The limited and scattered available particle size data
point out a need for a reliable, consistent, and widely used
technique for measuring particle size distribution. This
would enable valuable data to be collected for different
coal/boiler applications and different operating conditions.
5-9
-------
5.4 COSTS
Installation costs for precipitators, scrubbers, and
fabric filters applied to a model plant have not been esti-
mated; the results would present a biased cost picture that
depends largely on the selected boiler and fuel. Thus a few
selected model cost estimates would present a less-than-
accurate overall picture of cost comparison. In addition,
variable site-specific conditions can greatly affect in-
stallation costs of control systems.
Limited cost data were available from two scrubber
installations and two fabric filter installations.
Using the costs presented for precipitators, it is
evident that both the total mass and fractional collection
efficiencies of a control device must be considered. For
example, a comparison of precipitators for cyclone and
pulverized-coal-fired boilers with roughly equal efficien-
cies in the range of 0.2 to 0.4 micron (83% cyclone vs. 82%
pulverized coal), shows the cyclone boiler precipitator to
be only slightly more expensive than that for a similar
sized pulverized-coal boiler. The corresponding overall
mass collection efficiency of the precipitator for the
cyclone boiler, however, is less than that of the precipi-
tator for the pulverized-coal boiler (99% vs. 99.5%). When
the overall mass collection efficiencies of the two control
, 5-10
-------
systems are both 99.5 percent, the cyclone boiler precipi-
tator becomes about 31 percent more expensive than the
precipitator for the pulverized-coal unit. In this instance,
however, the fractional efficiency of the cyclone boiler in
the 0.2 to 0.4 micron range does increase considerably (83%
to 89%) . A similar comparison should be made when deter-
mining the cost of installing any type of control device on
a coal-fired utility boiler; i.e. the fractional control
efficiency should be studied in addition to the overall
control efficiency.
5-11
-------
REFERENCES - SECTION 5.0
1. Sondreal, E.A., and P.H. Tufte. "Scrubber Developments
in the West. U.S. ERDA, Grand Forks Energy Research
Center. Grand Forks, North Dakota, 1975.
2. Green, G.P. "Problems and Control Options Using Low
Sulfur Coal in Utility Boilers." Public Service
Company of Colorado. Presented at the Symposium of
Particulate Control in Control in Energy Processes.
September, 1976.
5-12
-------
APPENDIX A
LIST OF U.S. POWER PLANTS WITH
ELECTROSTATIC PRECIPITATORS HAVING
EFFICIENCIES OF 95 PERCENT OR GREATER
A-l
-------
>
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE * AB
UNIT F U E L —PARTICULATE— —S02
N SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
ST MO YR MM I 2 UTU MOIS MIN MAX AiH YR PE MFR EFY Y YR PE MFR SLT
UTILITY CO. NAME
TVA
ALABAMA PMK
ALABAMA PWR
ALAUAMA PWR
ALAbAMA PwR
ALABAMA PWR
ALAdAMA PWR
AL40A.1A PWR
ALAflAIA
ALABAMA
ALAbAHA
ALABAMA PrtR
PLANT
COLBERT
GORGAS
BARRY
BARRY
GASTUN
GREENE
.GREENE
GASTON
GASTUN
GASTON
BAKKY
3AKRY
BARKY
GASTUN
GORGAS
NAME
E.C.
COUNTY
COUNTY
E.G.
E.C.
E.G.
E.C.
UN
IT
05
10
05
04
02
02
01
01
03
03
02
01
05
09
L 0 C A T
CITY
PRIOE
GORGAS
BUCKS
BUCKS
MILSONVILLE
OEMOPOLIS
BEMOPOLlS
WILSONVILLE
WILSGNVILLE
BUCKS
BUCKS
BUCKS
WILSGNVILLE
GOKGAS
AB 11 65 550 C3
11032
3.5 4.2 12.3 75 PE
99-7
AB
AB
AB
AB
AB
AB
AB
AB
AB
AS
AD
A3
AB
AB
06
».
03
04
04
06
06
02
05
72
71
69
60
69
65
60
62
61
59
56
54
74
58
700
712
350
250
250
250
250
^50
250
225
125
125
380
165
CB
CB
CB
CB
CB
CB
CB
C
CB
CB
CB
CB
C
CB
0
0
0
0
U
0
0
0
0
11751
11B15
11815
11509
11757
11757
1150V
11 = 09
11509
Ilol5
11S15
11*15
11509
11751
7.1
7.7
7.7
7.5
6.6
6.6
7.5
7.5
7.5
7.7
7.7
7.7
7.5
7.1
.6
.9
.9
.7
1.0
1.0
.7
.7
.7
.9
.9
.9
.7
.6
3.7
3.2
3.2
2.o
1.3
I. a
2.6
2.6
2.6
J.2
3.2
3.2
2.6
3.7
16.0
14.4
14.4
14.7
14.9
14.9
14.7
14.7
l^.f
lH.4
14.4
14.4
14.7
16.0
72
7j
73
73
73
73
73
72
73
73
7d
73
71
Pfc
PE
PE
HP
HP
HP
HP
HP
HP
HP
HP
HP
PE
PE
flu
BU
BU
BU
RC
RC
RC
KC
RC
WA
HA
WA
kP
«P
98.0
98.5
98.5
99.3
99.1
99*1
99.3
9S.3
99. f
99.0
99.0
99.0
93.0
99.5
PI TV
ss
ss
ss
ss
ss
ss
ss
SUBTOTAL
ALL UNITS
MM
15 5.332
— COAL — OIL — GAS —NUCLEAR-
UNITS MM UNITS MM UNITS MM UNITS MW
15 5.332
-------
DATE RUN 12/24/75
ELECTRIC UTILITY UATA
LIST OF UNITS INSTALLED THROUGH 1975 bY STATE
STATE = AI
UTILITY CO. NAME
SALT RIVER PROJ
SALT RIVER PKOJ
PLANT NAME
NAVAJO
NAVAJO
UN L I
IT C
01 PAGE
02 PAGE
LOCATION
CITY ST
AZ
AZ
UNIT F U E L —PARTICULATE— :—S02
SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
MO YR MH 1 2 6TU HOIS MI* HAX ASH YR PE MFR EFY Y YR PE MFR SLT
74
75
770 CS
770 CS
11070
11070
.4
PE rtP 99.5
PC HP 99.5
Pi
PI
dE
bE
SUBTOTAL
ALL UNITS
— COAL — on. — GAS —NUCLEAR--
MW UNITS MM UNITS MM UNITS MH UNITS KW
1,540 2 1,540
-------
DATE RUN 12/2W75 fcLECTRIt UTILITY DATA PAGE NO 3
LIST OF UNITS INSTALLED THkOUiiH 1975 «JY STATE
STATE - CL
UNIT —" -F U E L —PARTICULATE— —S02
UN LOCATION SUE TYP£ HcAT PCT SULF-PCT PCT TY PCT R TY CON
UTILITY CO. NAHE PLANT NAHE IT CITY ST HO YR MW 1 2 BTO MOIS MIN MAX ASH YR PE HFR EFY Y YR PE MFR SLT
COLORADO DTE ELEC. HAYDEw 01 HAyDEN CL 65 185 CS 10770 H.l .4 ** IQ '2 73 HP By 99,6
— ALL UNITS ~ COAL — — OIL — '— GAS —NUCLEAR
MM UNITS MM UNITS MM UNITS MM UNITS MM
SUBTOTAL 1 165 1 165
-------
DATE RUN 12/2V75
ELECTRIC UTILITY DATA
PAGE NO
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = CN
UTILITY CO. NAME
UNITED ILLUM.CO.
PLANT NAME
BRIDGEPORT HSR
UN
IT
LOCATION
CITY ST
01 BRIDGEPORT
Crt
UM I f
SIZE TYPE HEAT
HO YR MH 1 i 6TU
U E L
PCT SULF-PCT PCT
51
75 CS 0
HOIS MIN MAX
1.5 1.5
ASH
—PARTICULATE— —S02
TY PCT R TY CON
YR PE MFR EFY Y YR PE HFR SLT
PE RC 97.5
— ALL UNITS
SUBTOTAL
— COAL — OIL —
MM UMTS HW UNITS HU
75 1 75
— GAS —NUCLEAR—
UNITS HU UNITS MM
-------
tlECIRiC UTILITY OA1A PAGE NO 5
LIST Of UNITS INiTAUEU THROUGH 1*75 BY STATE
STATE = DC
UM1 F U E L —PAKT1CULAT6— —SU2
UN LOCATION SUE TYPt HEAT PCT SULF-PCT PCT TY PCT R TY CON
UTILITY CO. NAME PLANT NAME IT CITY ST MU YR HN 1 2 BTU HOIS M1N MAX ASH YR PE MFR EFY Y YR PE MFR SLT
POTOMAC ELEC PwR BENNlNG 14 WASHINGTON OC 52 28 c8 12985 5*1 -6 1.0 Ifl-i "E AT 9?.9
POTOMAC ELtC PtJR BENNlNG 13 WASHINGTON DC <>7 55 C8 12985 5.1 .6 1.0 10.1 PE RC 9fa.O
* ALL UNITS — COAL ' — UIL — GAS —NUCLEAR
MW UNITS MM UNITS MM UNITS MM UNITS MM
SUBTOTAL 2 83 2 83
-------
DATE RUN 12/2V75
ELECTRIC UTILITY DATA
PA&k NO
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = OE
UTILITY CO..NAME
DELMARVA PHR I LT
OELMARVA PMR b LT
OELMARVA PNR t LT
PLANT NAME
DELAWARE CITY
INDIAN RIVER
INDIAN RIVER
UN L 0 C A T I
IT CITY
03 DELAWARE CITY
01 MILLSflORO
02 MILLSBORO
0 N
ST
D£
OE
OE
UNIT —
"•^""•*^»l
SI/E TYPE
MO YR
61
5b
56
MM 1
66 C
73 C
75 C
2
G
0
0
F U E
HEAT PCT
6TU MO IS
14019 7
12231 5.8
12231 5.8
: L
SULF-PCT PCT
MIN MAX ASH
7.2 7.2 3
.1 3.2 12. a
.1 3.2 12.6
— PARTICULATE —
TY
YR PE
ME
75 ME
75 ME
PCT R
MF* EFY Y
RC 97.5
RC 99.5
RC 99.5
— S02
TY
YR PE
CON
MFR SLT
GA
DELMARVA PUR C LT INDIAN RIVER 03 MILLSBORO
DE
70 167 C 0 12231 5.8 .1 3.2 12.6 70 Pfc UP 98.0
SUBTOTAL
ALL UNITS
— COAL — OIL — GAS —NUCLEAR—
MM UNITS Mb UNITS Mrf UNITS MH UNITS MM
383 4 383
-------
DATE RUN 12/24/75
ELECTRIC UTILITY OATA
NO
LIST UF UNITS INSTALLED THRUUGH 1975 BY STA Ft
STATt - PL
UNIT F U E L —P ARTICULATE— —S02-
TY CON
UTILITY CO. NAME
TAMPA EL.CO.
SS
ss
SS
ss
SN
1
oo
GULF POWER CO
GULF PCWER CO
GULF POKER CO
GULF POrfER CO
GULF POWER CO
GULF POWER CO
GULF PdwER CO
GULF POhER CO
TAMPA EL. CO.
TAMPA EL. CO.
TAMPA EL. CO.
TAMPA EL. CO.
SUBTOTAL
PLANT NAME
FRANCIS J. GANN
CRIST
CRIST
LANSING SMITH
LANSING SMITH
CRIST
CRIST
SCHULZ
SCHQLZ
FRANCIS J. GANN
FRANCIS J. GANN
BIG BEND
BIG 8ENO
UN
IT
04
06
07
01
02
05
04
02
01
05
06
01
02
LOCATION
CITY
TAMPA
PENSACOLA
PENSACOLA
PANAMA CTY
PANAMA CTY
PENSACOLA
PENSACOLA
CHATTAHOOCMEE
CHATTAHOOCHEE
TAMPA
TAMPA
— — — — A I 1 1 1M I T <
™—— •• Aul- UW1 I i
13
ST
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
MO YR
63
70
73
65
to?
61
59
53
53
65
67
70
1 73
SIZE TYPE HEAT
Mh 1
180 C
323 CB
505 CB
125 C
160 C
75 CB
75 CB
40 CB
<*0 CB
240 C
325 C
350 CB
300 CB
2 BTU
11325
12179
12179
11522
11522
12179
12i79
12
-------
UATE RUN 12/24/75
ELECTRIC UTILITY UVTA
PAGE NO
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE «= GA
UTILITY
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GfcuSGI A
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GEORGIA
GcORGIA
GEORGIA
GEORGIA
CO. NAME
PWR.CO.
PWR.CO.
PWR.CO.
PHR.CO.
PWR.CO.
PWR.CO.
PhR.CO.
PNR.C.O.
PWR.CO.
PWR.CO.
PWR.CO.
HWR.CJ.
PWR.CJ.
PWR.CO.
PMR.CO.
PWR.CO.
PWR.CO.
PWR.CO.
PWR.CO.
PWR.CO.
PWR.CJ.
PWR.C'J.
PWR.CO.
PWR.CO.
PHR.CO.
PWR.CO.
PLANT NAME
MC OONOUGH JACK
MC OONOUGH JACK
HAMMQNU
HARLLEE BRANCH
YATES
YATES
YATES
YATES
HAMMOND
YATES
YATES
MITCHELL
YATES
MITCHELL
MITCHELL
BOWEN
ARKWRIGHT
BOWEN
BOW EN
HARLLEE BRANCH
BOW EN
HAMMOND
HAMMOND
ARKWRIGHT
ARKWRIGHT
ARKWRIGHT
UN
IT
01
02
04
04
05
04
03
02
01
06
07
03
01
02
01
04
03
02
01
03
03
03
02
01
02
04
LOCATION
CITY
SMYRNA
SMYRNA
COOSA
M1LLEDGEVILLE
NEWMAN
NEWMAN
NEWMAN
NcWMAN
COOSA
NEWMAN
NtuMAN
ALBANY
NEWMAN
ALdANY
ALBANY
TAYLORSVILLE
MACON
TAYLORSVILLE
TAYLORSVILLE
MILLEOGEVILLE
TAYLORSVILLE
COOSA
COOSA
MACON
MACON
MACON
ST
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
GA
MO YR
07 63
05 64
70
06 69
05 58
06 57
06 52
11 60
Oo 54
74
74
04 46
09 50
03 49
11 48
75
09 «.3
72
71
06 68
74
06 55
09 54
06 41
05 42
11 *8
UN 11
— — r- u e L- '
SIZE TYPt HEAT PCT
MM 1
245 C
245 C
505 C
490 C
125 C
125 C
100 C
100 C
100 C
350 C
350 C.
125 C
100 C
23 C
23 C
876 C
40 C
712 C
712 C
431 C
67fe C
100 C
100 C
40 C
40 C
*rO C
2 BTU MOIS
11963
11983
12236
0 11746
1^390
12390
12390
12i90
12236
12390
12390
0 11*37
1^390
0 11337
0 11337
11265
11595
11595
0 11748
12236
1223o
G 11265
G 11285
11265
SULF-PCT PCT
MIN MAX
.6 1.3
.6 1.3
.3 3.4
.7 2.2
1.0 2.9
1.0 2.9
1.0 2.9
1.0 2.9
.3 3.4
1.0 2.9
1.0 2.0
.7 3.0
1.0 2.9
.7 3.0
.7 3.0
2.5 2.5
.7 4.0
.9 3.1
.9 3.1
.7 2.2
2.5 2.5
.3 3.4
.3 3.4
.7 4.0
.7 4.0
.7 4.0
ASH
14.2
14.2
12.6
20.0
16.8
16.8
16.8
16.8
12. a
16.6
16.8
12.0
16. 6
12.0
12.0
12.0
12.7
12.7
20.0
12.6
12.6
12.0
12.0
12.0
— "TMR 1 1 WUUM 1 C
TY
YR PE
PE
PE
67 PE
PE
PE
PE
PE
PE
PE
71 PE
71 PE
73 Pt
71 PC
PE
PE
72 PE
PE
68 PE
66 PE
PE
72 PE
PE
PE
73 PE
73 PE
73 PE
MFR
au
BU
BU
BU
BU
BU
BO
BU
bU
BU
BU
BU
bU
RC
RC
RC
RC
RC
RC
RC
RC
wP
WP
WP
WP
WP
PCT R
EFY Y
98.0
96.0
96.0
93.3
96.3
98.3
98.3
98.3
96-7
99.0
99.0
99.0
99.1
96.0
95.0
96.0
98.0
96.0
98.0
96.5
99.0
9o.O
98.0
99.0
99.0
99.0
,JW*>
TY CON
YR Pt MFR SLT
SS
UE
ue
SS
SS
SS
OH
SUBTOTAL
ALL UNITS
MW
26 7,023
— COAL — OIL — GAS —NUCLEAR-
UNITS MW UNITS MW UNITS MH UNITS MM
26 7,023
-------
OATE RUN 12/24/75
ELECTRIC UTILITY L.ATA
PAGE NO
LIST OF UNITS INSTALLED THROUGH 1975 BY STATc
STATE = IL
>
1
wi«* i r
UTILITY CO. NAME
CENTRAL ILL.LT.
COMMUNwEALTH EDISON
COMMONWEALTH EDISON
ELECTRIC ENERGY
ELECTRIC ENERGY
ELECTRIC tNERGY
ELcCTRIC ENERGY
SPRINGFIELD WT.LTtPW
SPRINGFIELD WT.LTtPW
SO ILLINOIS PWR COOP
SO ILLINOIS PW* COOP
SO ILLINOIS ?W* COOP
CENTRAL ILL. P S
ILLINOIS PWR.
ILLINOIS PWR.
ILLINOIS PWR.
ILLINOIS PWR.
CENTRAL ILL. P S
COMMONWEALTH EDISON
COMMONWEALTH EDISON
CENTRAL ILL. P S
CO-MONwEALTH EOISON
COMMONWEALTH EOISON
COMMONWEALTH EOISON
COMMONWEALTH EOISOM
COMMONWEALTH EOISJN
CCMMU-iwEALTH EOISON
COMMONWEALTH EJISON
COMMONWEALTH EOISON
COMMONWEALTH EOISON
COMMONWEALTH EDISON
COMMONWEALTH cOISON
.COMMO-NhtALTH EOISON
COMMONWEALTH EOISON
PLANT NAME
WALLACE R.5.
HAUKEGAN
WILL COUNTY
JOPPA
JOPPA
JOPPA
JOPPA
DALLMAN
LAKESIDE
MARION
MARION
MARION
COFFEEN
WOOD RIVER
VERMILION
HENttEPIN
HENNEPIN
MEREOOSIA
JOLIET
WAUKE&AN
GRAND TOWER
KINCAID
CRArfFURD
JOLIET
FISK
JOLIET
WILL COUNTY
CRAWFORD
JOLIET
WAUKEGAN
WILL COUNTY
K.INCAIO
WILL COUNTY
* 2 OcFERRED IN
UN
IT
07
05
01
03
OA
01
02
01
04
01
03
02
02
05
01
02
01
03
06
08
04
02
Ob
07
19
08
04
07
05
06
03
01
02
4)5
L 0 C A T I
CITY
E. PEOR1A
JOLIET
MASSAC CTY
MASSAC CTY
MASSAC CTY
MASSAC CTY
SPR INGFIELO
SPRINGFIELD
MARION
MARION
MARION
COFFEEN
EAST ALTON
OAK HOOD
HENNEPIN
HENNEPIN
M EREUOS I A
JOLItT
GRAND TOWER
KINCAID
CHICAGO
JOLIET
CHICAGO
JOLItT
JULIET
CHICAGO
JOLIET
JOLIcT
KINCAIO
JOLIET
PEKIN
0 N
ST
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
IL
MO YR
58
31
55
68
50
6 63
9 63
a 63
3 72
64
52
59
50
60
59
62
58
o&
61
65
59
66
63
58
50
52
57
67
55
A 72
SIZE TYPE
MW 1 2
100 C
130 CS G
188 CS
174 C
174 C
174 C
174 C
80 C
20 C
33 C
33 C
33 C
600 CB
3o9 C G
77 C
235 C G
7to C G
237 C
3oO C
355 CS t>
194 C
600 «,
3=d CS G
obO CS G
374 CS G
tbO CS G
5S8 CS
239 CS G
107 C
111 CS G
29V CS
ofcO Cd
Id* CS
040 CS
HEAT
BTU
10623
11042
10114
3115
3115
3115
3115
1U375
10375
10000
10964
10S31
11017
11017
10880
1029
11042
10833
9706
9124
10570
9124
10570
10114
9124
1029
11042
10114
96 1 6
10114
10383
y C l_ — — — — —
PCT SULF-PCT PCT
KOIS MIN MAX ASH
17.3 2.6 2*8 9.5
16.1 .3 3.6 12.0
.3 i.O 15.8
10.8 2.2 2.2 25.1
10.8 2.2 2.^ 25.1
10. d 2.2 2.2 25.1
10.8 2.2 2.2 25.1
2.o
-------
)ATE RUN U/24/75
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
ELECTRIC UTILITY DATA
UTILITY CO. NAME
PLANT NAME
I-'
I-1
ILLINOIS PWR.
ILLINOIS PHR.
COMMONWEALTH EDISON
CENTRAL ILL. P S
CENTRAL ILL. P S
CENTRAL ILL. P S
CENTRAL ILL. P S
CENTRAL ILL. P S
CENTRAL ILL.LT.
CENTRAL ILL. P S
CENTRAL ILL.LT.
ILLINOIS PWR.
ILLINOIS PHR.
ILLINOIS PWR.
BALDWIN
WOOD RIVER
W AUK. EG AN
GRAND TOWER
MEREWSIA
MERtOOSIA
HUTSONVILLE
HUTSONVILLE
EOHARDSt E.O
COFFEEN
EDWARDS, e.D
BALDWIN
BALDWIN
VERMILION
PAGE NO 10
—PARTICULATE— —S02
UNIT F U £ L
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CCN
IT CITY ST MO YR MW 1 i tiTU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE MFR SLT
03 BALDWIN
0* EAST ALTON
07
03 GRAND TOHER
02 MEREUQSIA
01 MEREDOSIA
04 HUTSGNVlLLE
03 HUTSONV1LLS
02 BARTOMVlLLE
01 COFFEtN
03 6ARTUNVILLE
01 BALDWIN
01 BALDWIN
02 OAKWDUD
SUBTOTAL
48
ALL UNITS
1L
IL
IL
IL
IL
U
IL
IL
IL
IL
it.
IL
IL
IL
6 75
60
58
50
47
46
54
54
66
65
4 72
3 73
70
56
MM
13.320
632
103
326
73
65
65
78
78
250
365
350
604
626
109
c
C G
CS G
C
C
C
C
C
c
CB
C
C
C
c
r r\a *
""""" l*VJMfc_
UNITS
48
13
10574
10964
11042
10833
10880
10860
11214
11214
lOeUO
9297
10600
10574
X0574
10431
11.3
11.9
16.1
10.8
15.8
15.8
13.2
13.2
17.7
15.2
17.7
11.4
13.o
nil
MM UNITS
t320
2.8
.4
.3
2.3
2.8
2.8
1.6
1.6
2.6
3.6
1.4
2.8
2. a
1.1
MM
3.3
3.0
3.6
3.4
3.6
3.6
4.0
4.0
2.8
4.5
3.2
3.3
3.3
3.1
14.3
10.6
12.6
16.2
9.7
9.7
11.3
11.3
8.1
20.5
8.1
11.4
9.6
10.9
UNITS
72 PE
f £
74 HP
6* PE
71 Pt
71 PE
71 PE
71 PE
PE
72 .PE
PE
73 Pt
70 PE
72 PE
MM
RC
RC
HA
HP
Wi»
HP
HP
HP
HP
HP
mf
WP
WP
WP
99.5
99.6
99.1
97.1
96.0
98.0
99.0
99.0
9V.O
99.0
99.0
S9.0
99.0
99.5
M E i r i i
UNITS
OE MS
SL
SL
79 FS
CA
SL
SL
SL
MW
-------
DATE RUN 12/24/
tttClklC UTILITY OA1A
PAGE NO 11
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = IN
,
UT ILITY CO. NAME
INDIANAPOLIS prfR.
NORTHERN INDIANA
NORTHERN INDIANA
NORTHERN INuIANA
NORTHERN INDIANA
NORTHERN INDIANA
INDIANAPOLIS »>»JR.
INDIANAPOLIS PWR.
INDIANAPOLIS PriR.
P.S. OF INDIANA
P.S. OF INDIANA
PLANT NAME
dLT
PS
PS
PS
PS
PS
£LT
tLT
<
PERRY w
BAILLY
BAlLLY
MITCHELL 0.
MITCHELL 3.
MITCHELL 0.
STOUT ELMER
PRIJCHARD H
STOUT ELMER
EOWAKOSPURT
EDHARDSPORT
H.
H.
H.
W.
.T.
U.
UN
IT
07
08
07
05
04
06
06
06
07
02
03
L 0 C A T I
CITY
INDIANAPOLIS
DUNE ACRES
DUNE ACRES
GARY
GARY
GARY
INDIANAPOLIS
MAKTINSVILLE
INDIANAPOLIS
EOfcAKDSPORT
EUWARDSPORT
0 N
ST
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
VR
32
08
64
61
58
64
61
54
73
46
50
UNIT
SIZE
MW
11
422
194
138
138
138
100
100
450
t5
75
— —
•
TYPE
1
C
C
C
C
C
C
C
C
C
C
C
2
G
G
G
G
G
F
HEAT
BTU
1112V
11215
11215
11103
11103
114.03
11467
11047
11467
10947
10947
U E L
PCT
MOIS
13.1
12.0
12.0
11.7
11.7
11.7
12.4
K.2
12.4
13.5
13.5
SULF-PCT PCT
MIN
3.2
3.0
3.0
2.7
2.7
2.7
1.3
.9
1.3
1.0
1.0
MAX
3.2
4.0
4.0
3.6
3.6
3.6
5.3
3.5
5.3
2.9
2.9
ASH
11.6
10.0
10.0
10.4
10.4
10.4
9.4
11.2
9.4
10.3
10.3
— PARTICIPATE-
TY
YR PE
PE
PE
PE
69 PE
69 PE
69 PE
71 ME
71 PE
73 PE
72 PE
72 PE
MFR
AS
AS
AS
BU
BU
BU
BU
BU
PCT
EFV
99.0
98.0
98.0
98.0
98.0
98.0
99.0
99.0
99*5
98.0
98.0
R TY CON
Y YR PE MFR SLT
NJ
NORTHERN INDIANA PS MICHIGAN CTY 12 MICHIGAN CTY IN 2 74 520 C G 10691 13.7 1.0 4.0 10.0 72 PE KC 99.5
S. INDIANA G&E
INDIANA-MICH.=L.
CULLEY, F.B.
BREED
03 NEW3URGH
01 SULLIVAN
IN
IN
73 265 C
60 450 CS
13476 3.2 3.0 4.5 15.8 71 PE LC 98.0
10901
.3 6.0 28.0
PE 98.3
SL
BR
SR
COM'SCMEALTH EDISON
CG.-'.tfQN'rfEALTri SOISON
Ifcjl A.sAPGLIS PWR.tLT
lNOIA.>iA-MICH.EL.
INDIANA-MICH.EL.
INDIANA-MICH.EL.
INDIANA-MICH.EL.
P.S. Or INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
DIXON
STATE LINH
STOUT ELMirR W.
TANNERS C*EEK
TANNERS CrtEcK
TANNERS CREEK
TANKERS CREEK
nAbASH RVR.
WA84SH RVR.
WAdAStt RVR.
WABASH RVR.
WA6ASH RVK*
MAdASH RVR.
05
04
05
04
03
02
01
06
04
01
03
05
02
HAMtfOND
INDIANAPOLIS
LAWRtNCtdU^G
LAhReNCcSURG
LAnktNCcaUkG
LAV«RtNCc3URG
W. TtRRE HAUTE
M. TtRRE HAUTE
W* TcARE HAUTE
W. TERRE HAUTE
w. TERRE HAUTE
U. TERRE HAUTE
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
53
o2
58
64
54
52
51
66
54
46
53
5o
51
69
389
100
580
213
153
I5i
360
100
99
99
122
ioo
C G
CS G
C
ca
CtJ
Cd
Co
C
C
C
C
C
C
9646
9655
11-67
lOcbd
10668
10688
10^89
11004
11004
11004
11004
11004
11004
14.2
18.0
12.4
12.9
1^.9
12.9
12.9
12.9
12.9
1.3 4.0
.3 3.7
1.3 5.3
.8 4.4
.8 4.4
.8 4.4
.8 4.4
2.5 2.9
2.5 2.9
2.5 2.9
2.5 2.9
2.5 2.9
2.5 2.9
15.8
13.0
9.4
10.4
10.4
10.4
10.4
10.4
10.4
PE
PE
69 MC
75 PE
74 ME
74 Pt
74 PE
68 PE
69 PE
71 PE
71 PE
69 PE
70 PE
RC 96.3
RC 98.0
RC 99.0
RC 99.1
RC 99.7
RC 99.7
RC 99.7
RC 9B.O
RC 98.5
RC 98.5
RC 98.5
RC 98.5
RC 98.5
INDIANAPOLIS PrfR.£LT PETERS3URG
01 PETERSBURG
IN
67 220 C
10915 13.4 1.0 6.0 12.0 72 PE UP 99.5
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 12
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
1NDIA.NA-KENTJCXY cL
INDIANAPOLIS PW
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
P.S. OF INDIANA
S. INJIANA G&E
S. INDIANA GSE
SU9TOTAL
PLANT NAME
CLIFTY CREEK ST
PETERSBURG
N03LESVII.LE
NOBLcSVILLE
GALLAGM5K R.A.
GIsJSUN
GALLAGHER R^A.
GALLAGHcR K.A.
CAYUGA
GALLAGHER R.A.
CAYUGA
CULLtY, F.B.
CULLEY, F.I).
UN
IT
L 0 C A T I 0
CITY
06 .MADISON
02 PETERSoURG
02 NOBLcSVlLLE
01 NQSLtSVILLE
02 N£W ALdANY
02 PLAINFIELD
01 M£» ALBANY
04 NcW ALSA.NY
01 CAYUGA
03 N6U ALBANY
02 CAYUGA
02 NEndURGH
01 NEUSURGH
ALL UNITS
N
ST
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
^V4B^B>
MO YR
55
69
Lit
40
58
3 75
58
61
70
60
72
67
60
_____
MH
UNIT
SliE
MM
266
420
53
53
159
050
159
159
500
159
500
96
40
__
.
TYPE
1 2
CB
C
C
C
C
C
C
C
C
C
C
C
C
COAL
UNITS
f
He AT
8TU
10336
10915
H4¥d
11493
11267
11267
11267
10335
1126?
10335
10476
10476
___ •! —
U E
PCT
HOIS
13.4
11.4
11.4
11.6
11.6
11.6
14.3
11.6
14.3
3;2
3.2
OIL
MH UNITS
L
— PARTICJLATE —
SULF-PCT
MIN
.3
1.0
2.9
2.9
3.1
1.5
3.1
3.1
2.3
3.1
2.3
3.0
3.0
MM
MAX
6.0
6.0
2.9
2.9
4.1
1.5
4.1
4.1
2.3
4.1
2.3
4.5
4.5
— ^
PCT
ASH
12.0
12.0
8.9
8.9
10.3
10.3
10.3
13.0
10.3
13.0
15.8
15.6
- GAS
TY
YR PE
75 PE
69 PE
72 PE
72 PE
68 PE
75 PE
6tf PE
68 PE
70 PE
68 PE
71 PE
71 MC
72 MC
PCT
MFK EFY
HP 99.4
HP 99.0
MP 93.0
HP 98.0
MP 99.0
UP 99.0
HP 99.0
MP 99.0
MP 99.0
MP 99.0
Up 99.0
HP 99.3
HP 99.3
R
Y
— NUCLEAR-
UNITS MH
UNITS
MM
TY CON
YR P£ MFR SLT
SP
GH
SL
SL
SL
9,017
-------
DATE
12/24/75
ELECTRIC UTILITY OAT*
k>A.it NO I)
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = 10
UNIT F U E L —PART1CULATE— —S02
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
IT CITY ST MO YR MM 1 2 6TU HOIS HIM MAX ASH YR PE MFR EFY Y YR PE HFR StT
UTILITY CO. NAME
IOWA-ILLINOIS G6E
PLANT NAME
RIVcRS IDE
04 BETT£NOO*F
10
56
43 C
16.6 1.7 2.7 9.7 72 PE BU 99.1
INTERSTATE Prf*.
INTERSTATE PWR.
INTERSTATE P«iR.
IOWA P.S. CC.
IOXA P.S. CO.
LANSING 02 LANSING 10 46
KAPP M.L. 01 CLINTON 10
LANSING 01 LAUSING 10 39
GtOftGE NEAL 01 SIOUX CITY 10 64
GEurtGE NEAL 02 SIOUX CITY 10 72
11 CB
15 CB G
15 CB
CB G
147
11302 11.3 1.0 3.5
11030
11302
12700
10071
14.5 2.6 3.4
11.3 1.0 3.5
2.9 2.9
10.5
10.9
10.5
11.5
.4 1.2 13.2
73 PE RC 99.0
73 PE RC 99.0
73 PE RC 99.0
72 PE RC 99.0
HP RC 99.6
SL
SL
E8
IOWA ELEC. LT.SPWR.
JO«A ELEC. LT.CPWR.
lO^A ELEC. LT.dPrfS.
IOWA ELEC. LT.&PWR.
:> 10*A CLEC. LT.4.PWR.
-I, IOWA PWR.tLT.
,U IOWA SOUTHERN UTIL
PRAIRIE C*£EK 3
PKAIfUt CREEK 4
SIXTH STREET
SIXTH STREET
SIXTH STREcT "
COUNCIL BLUFFS
BURLINGTON
03 CEDAR RAPIOS 10
04 CEDAR RAPIOS lu
04 CEDAR RAPIOS 10
02 CEDAR RAPID5 10
01 CfcDAR RAPIOS 10
02 COUNCIL 3LUFFS 10
01 BURLINGTON 10
61
67
51
49
49
58
68
50
140
20
4
10
ti2
212
C
C
Co
CB
Cd
CS
CB
G
G
0
10306
10367
10257
10257
10257
10633
10219
16.9
16
16
16
16
13
10
.9
.9
.9
.9
.2
.9
1
1
1
1
2
.9
.6
.9
.9
.9
.9
.5
2.
2.
1.
1.
3.
1.
3.
4
7
9
9
7
5
0
10.3
37.1
37.1
10.3
8.8
9.1
70 PE UP 99.0
75 PE UP 99.0
73 PE UP 99.0
73 PE UP 99.0
73 PE UP 99.0
72 HP UP 99.3
67 PE UP 98.0
SV
INTERSTATE PUR.
INTERSTATE PrfR.
IOWA P.S. CO.
DUBUClUE
LAPSING
MAYNARO
03 DUBUQUE
03 LANSING
07 WATERLOO
10 50 25 Cri b 11326 11.3 2.9 3.1 10.9
10 61 33 CB 11302 11.3 3.0 3.0 10.5
10 50 54 Cd G 1072B 2.9 3.5
73 PE HP 99.0
73 PE UP 99.0
72 HP hP 99.0
SUBTOTAL
— ALL UNITS
16
MM
1,401
~ COAL — OIL — CAS —NUCLEAR-
UNITS MM UNITS MM UNITS MM UNITS Mta
16 1,401
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE • KY
CT'
UTILITY CO. NAME
LOUISVILLE GSE
OWENSaCRO
c. KENTUCKY RS EL.
E. KENTUCKY Rft EL.
E. KENTUCKY Ri< EL.
c. K.C.MUCKY RR EL.
Ke^TlCKY UTIL.
KENTUCKY UTIL.
KcNUCKY UTIL.
KENTUCKY UTIL.
KENTUCKY UTIL.
KENTUCKY PWR,
3IG RIVERS CO-OP
BIG DIVERS CO-OP
KE.VTUCKY PWR.
KENTUCKY UTIL.
LOUISVILLE GtE
LOUISVILLE GtE
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
KENTUCKY UTIL.
LOUISVILLE G6E
LOUISVILLE G&E
SUBTOTAL
PLANT NAME
CANE KUN
SMITH E.
DALE M.C.
DALE M.C.
COOPER J.i.
CObPcS J.S.
PINEVILLfc
EtRuMN E.U.
GREEN RIVER
GREEN RIVEn
BROWN E.W.
BIG SANDY
COLEMAN
COL tHAN
BIG SANDY
BPQ^H E.W
CANc *UN
CANE RUN
SHAHNEE
SHAriNEE
SHAWNEE
SHAWitEE
SHAWNEE
SHAWNEE
SHA-WNEE
SHAWN EC
GHENT
MILL CREEK
MILL CRcEK
PARTICULATE—
R
Y
UN L 0 C A T I 0
IT CITY
04 LOUISVILLE
02 OMENSBOKO
04 FORD
03 FORD
01 8UKNSIGE
02 BUR iMS I DC
03 FOUR MILE
01 BURGIN
03 CENTRAL CITY
04 CENTRAL CITY
02 BURGIN
01 LAURENCE
02 HANESVILLE
01 HAhcSVILLE
02 LAURENCE
03 UUrvGIN
03 LOUISVILLE
05 tUUISVILLe
06 PADUCAH
07 PAOUCAH
05 PAOUCAH
10 PADUCAH
04 PAOUCAH
03 PAOUCAH
02 PAOUCAH
08 PAuUCAM
01 PAOUCAH
09 PAOUCAH
01 GHENT
01 KOSMOSOALE
02 KOSMOSOALE
* * t L t+t T ^ r
31
N
ST
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
KY
SIZE TYPE HEAT PCT
MO YR
62
7*
8 60
d 57
2 65
69
38
57
52
59
63
63
70
69
69
71
38
66
11 54
12 54
10 54
1C 56
01 54
10 53
06 53
03 55
04 53
07 55
74
5 72
5 74
MM
6t45J
Mb 1
138 Cd
265 C
72 C
72 C
114 C
221 C
32 CB
105 Cb
72 C6
105 CB
165 CB
265 C3
185 C
185 C
600 Cd
<*n CB
137 CB
183 Co
175 C6
175 Co
175 CB
175 Cu
175 Co
175 Co
175 CB
175 C6
175 C6
175 CB
500 CB
330 CB
2 BTU MOIS
G 11267
10663 12
1195o 7
11956 7
11332 5
11332 5
12336 5
11S79 5
11276 11
11276 11
11879 5
11139
11117
11117
11139
Ild79 5
G 11267
G 11267
10d50
10850
10850
10350
10350
10d50
10850
10o50
10850
10o50
10800
G 11400
330 Cb G
UNITS MW UNITS
31 6,453
.7
.6
.6
.7
.7
.6
.9
.5
.5
.9
.9
n r i
U&L
SULF-PCT PCT
MIN
3.3
3.2
.8
.8
1.5
1.5
.9
.8
.6
.6
.8
.7
2.8
2.8
.7
.a
3.3
3.3
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.7
3.2
3.2
MU
MAX
3.8
3.2
1.5
1.5
3.3
3.3
6.8
3.1
3.5
3.5
3-1
3.2
3.6
3.6
3.2
3.1
3.U
3.8
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
3.8
3.7
3.2
ASH
13.7
12.0
16.4
16.4
15.6
13.1
10.9
10.9
13.1
12.2
12.2
13.1
13.7
13.7
12.2
14.2
14.2
r* * e
UNITS
YR
72
72
71
71
73
71
73
73
73
69
70
69
69
74
69
69
69
o9
69
69
69
09
69
69
69
70
MM
TY
PE MFR
PE
PE
PE AS
PE AS
PE AS
PE AS
PE BU
HE BU
PE 6U
PE 3U
PE BU
PE KC
PE RC
PE RC
PE RC
PE RC
PE RC
PE RC
ME RC
ME RC
ME RC
ME RC
ME RC
ME RC
ME RC
Mt RC
ME RC
ME RC
PE MP
PE UP
PE UP
PCT
EFY
98.5
99.5
96.0
96.0
98.0
98.0
98.5
98.5
98.5
99.0
99.0
98.5
99.0
99.0
98.5
99.0
97.5
98.5
9U.O
98.0
98.0
98.0
98.0
96.0
98.0
98.0
98.0
96.0
98.0
99.4
99.4
&ttir*i i
UNITS
—S02
TY CON
YR PE MFR SLT
AH
av
SL
AM
RP
SL
75 FS CE
FS BE
BU
SL
PI
PI
MM
-------
DATE RUN 12/2V 75
LIST OF UNITS INSTALLED THROUGH 1975 bY STATE
UTILITY .CO. NAME
STATE = MC
CONSUMERS ?WR
CONSUMERS PWR
LANSING BD *T & LT.
LANSING BO WT t LT.
LAr.SING BD WT & LT.
LANSING BO WT £ LT.
LANSING BD WT C LT.
LANDING BD WT fc LT.
CONSUMERS PWR
CONSUMERS PwA
CONSUMERS PWR
CONSUMERS PWR
CONSUMERS PWR
CONSUMERS PWR
CONSUMERS PW*
UPPc* PENINSULA PWR.
DETROIT EDISON
DETROIT EOISUN
DETROIT EDISON
DETROIT EDISON
DETROIT EOISO.M
DETROIT EDISON
DETROIT fcOISON
LANSING BO WT u LT .
LANSING BD WT t LT .
LANSING 6D HT & LT.
LANSING BD WT t LT.
LANSING BD WT £ LT.
LAPSING 60 wT S LT.
DETROIT EDISON
DETROIT EDISON
DETROIT EDISON
DETROIT EDISON
PLANT NAME
WEAOUCK. J.C.
WtAOQCK J.C.
ERICKSON
OTTAWA
OTTAWA
OTTAWA
OTTAWA
OTTAWA
KARN D.E.
KARN O.c.
WHITING J.R.
WHITING J.R.
WHITING J.R.
CAMPBELL J.H.
CAMPBELL J.H.
pREsaue ISLE
RIVER ROUGE
MARYVILLE
MARYVILLE
MUNRGE
MJNROE
MuNkLit
Mu^ROt
ECKSKT, O.E.
fcCKERT, O.E.
ECKERT, O.E.
ECKEftT, O.E.
ECKERT, O.E.
ECKERT, O.E.
ST. CLAIR
ST. CLAIR
ST. CLAIR
ST. CLAIR
UN L 0 C A T
IT CITY
08 BAY CITY
07 tJAY CITY
01 LANSING
05 LANSING
03 LANSING
02 LANSING
01 LANSING
04 LANSING
01 ESSEXVILLE
02 ESSEXVILLE
01 ERIE
03 ERIE
02 ERIE
01 WfcST OLIVE
02 WEST OLIVE
05 «ARQUETT£
03 RIVER ROUGE
07 MARYVILLE
08 MARYVILLE
02 MONROE
01 MONROt
03 MONROE
04 MONROE
05 LANSING
06 LANSING
04 LANSING
02 LANSING
03 LANSING
01 LANSING
01 BELLE RIVE
04 BELLE RIVE
03 BELLE RIVc
02 BELLE RIVE
ELECTRIC UTILITY DATA
UNIT F U E L
N SIZE TYPE HEAT PCT SULF-PCT PCT
ST HO YR KW 1 2 BTO HOIS WIN MAX ASH
—PARTICULATE—
TV PCT R
YR PE HF* EFY Y
HC
MC
MC
MC
MC
MC
MC
MC
f.C
MC
MC
MC
Mr
ns,
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
MC
58
55
73
49
48
41
38
49
59
61
52
54
i y
382
i i A u y
L iGtff.
11203
1U03
12540
12397
12030
12030
12V4B
12948
12946
12S48
12382
12382
12382
12382
12382
12382
12066
12066
12066
12066
7.5
7.5
6.0
6.0
6.0
6.0
6.0
8.7
8.7
7.1
7.1
8.2
8.2
5.3
5.8
5.8
5.3
3.1
3.1
3.1
3.1
5.5
5.5
5.5
5.5
5.5
5.5
7.2
7.2
7.2
7.2
.4
.4
2.0
2.5
2.5
2.5
2.5
2.5
.6
.6
.7
.7
.8
.8
1.5
.5
1.6
1.6
2.7
2.7
2.7
2.7
2.3
2.3
2.3
.8
.8
.8
1.6
1.6
1.6
1.6
3.7
3.7
3.9
2.5
2.5
2.5
2.5
2.5
3.7
3.7
4.4
4.4
3.3
3.3
2.8
3.8
4.6
4.6
3.7
3.7
3.7
3.7
3.1
3.1
3.1
3.1
3.1
3.1
4.6
4.6
4.6
4.6
14.7
14.7
11.5
12.6
12.6
12.6
12.6
12. b
14.7
14.7
14.3
14.3
1 J. ~1
A *f » J
17.9
14.5
11.2
14.7
14.0
14.0
12.0
12.0
12.0
12.0
11.5
11,5
11.5
11.5
11.5
11.5
14.0
14.0
14.0
14.0
PE
PE
PE
PE
PE
PE
PE
PE
P£
72 PE
72 PE
"J Or O C
im- " C
74 PE
67 PE
73 PE
58 PE
69 PE
69 PE
73 P£
73 PE
PE
72 PE
73 PE
73 PE
73 PE
75 PE
75 P£
75 PE
74 ME
74 ME
74 Me
74 HE
AS
AS
AS
AS
A C
M J
BU
au
BU
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
WH
WH
WH
WH
99.0
9V. 0
95.0
97.5
97.5
97.5
97.5
97.5
95.0
95.0
99.0
99.0
QQ A
7 7» W
97.0
9o.O
99.0
97.8
99.4
99.4
99.6
99.6
99.6
99.6
97.4
97.4
97.4
98.4
96.4
98.4
99.6
99.6
99.6
99.6
PAGE NO 15
—502
TY CON
YR PE MFR SiT
CA
CA
SE
PI BE
CA
CA
CA
CA
CA
St.
Ota
On
OU
DM
OM
OW
OM
-------
DATE RUN
ELECTRIC UTILITY BATA
PAGE NO 16
CIST OF UNITS INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
CONSUMERS P*R
CONSUMERS PhR
CGNSOKERS PWR
CONSUMERS
UN
PLANT NAME IT
C3B8
C086
COdd
cosa
COBB
B.C.
B.C.
b.C.
a.c.
tJ.C.
05
04
03
01
02
L 0 C A T
CITY
MUSKEGON
MUSKEGON
MUSKEGuN
MUSKEGON
MUSKEGuN
ION
ST MO YR
MC
MC
MC
MC
MC
57
56
50
48
40
SUE
MH
156
136
66
66
66
T
1
C
C
C
C
C
UNIT f-
E HEAT
2 UTU
— ALL UNITS
U E L ' —PARTICULATE— —S02
PCT SULF-PCT PCT TY PCT R TY CON
MOIS MIN MAX ASH YR PE MFR EFY V YR PE MFR SLT
CA
CA
CA
CA
CA
SUBTOTAL
38
— COAL -
MK UNITS
7,274 36 7,274
11592 10
11592 10
11592 iO
11592 13
11592 10
_
ri UNITS
.9
.9
.9
.9
.9
OIL
1.5
1.5
1.5
1.5
1.5
MM
4
4
4
4
4
._
.6
.6
.6
.6
.6
M —
9.
9.
9.
9.
9.
2
2
2
2
2
GAS
UNITS
PE
PE
69 PE
PE
PE
MP
MP
MP
WP
MP
99
99
99
99
99
.0
.0
.0
.0
.0
— NUCLEAR—
MM
UNITS
MM
I
H
^1
-------
DATE RUN 12/24/75
ELECTRIC UTILITY UATA
PAGE NO 17
LIST OF UNITS INSTALLED THROUGH 1975 faY STATE
STATE » HO
UNIT -—-F U E L —PARTICULATE—
UN LOCATION SIZE TYPE HcAT PCT SULF-PCT PCT TY PCT R
IT CITY ST MO YR MW 1 <:
-S02-
TY
CON
UTILITY CO. NAME
POTOMAC EDISON
PLANT NAME
SMITH K.PAUL
04
75 CiJ
bTU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE MFR SLT
11066 6.2 «6 2.5 15.3 71 PE 6u 99.0
POTOMAC ELEC PWR
POTOMAC ELEC PWR
*>«3TO«AC ELEC PufR
POTOMAC ELEC PWR
POTOMAC ELEC P*R
POTOMAC ELEC P«|R
DICKERSON
DICKERSON
DICKt*SON
CHALK POINT
MORUANTOMN
MuRGANTOriN -
02
03
01
02
01
02
=4 DEFERRED
=
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 18
U)
LIST OF UNITS
STATE = MI
INSTALLED THROUGH 1
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 19
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = MO
ONIT F U E L —P ARTICULATE— —S02
UN LOCATION SUE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
PLANT NAME IT CITY ST MO YR M«l 1 2 8TU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE HFR SLT
UTILITY CO. NAME
KANSAS CTY. PWR.6LT. HAWTHORN
Oa KANSAS CITY
69 493 CB 6 10409 14.4 .6 3.0 8.2 69 PE SU 99.0
UiNICN ELEC.
RUSH ISLE
01 CRYSTAL CITY MO 10 75 590 C 10400 9.7 1.2 1.2 18.7 72 PE LC 99.5
BE
UNION
UNIJN
UNION
UMCN
U.'.IUN
UNION
UNI ON
UNION
ELEC.
ELEC.
ELEC.
&LEC.
ettc.
ELEC.
ELcC.
ELEC.
ELEC.
™ ASSCC ELEC COOP
0 MliSO'JRI P.S.
MISSOURI P.S.
SPRIN3FIELD CTY U.
MERAMfcC
MERAMEC
MEkAMEC
LudAUIE
LA8ADIE
LA6A01E
LABAOIE
SIOUX
SIOUX
NEW MADRID
SI3LEY
SI6LEY
JAMES RVR.
01 SE ST. LOUIS
02 SE ST. LOUIS
03 St ST. LOUIS
03 LA8AOIE
Ot LA6AOIE
02 LA6AOIE
01 LABAOIE
02 PRTGfc DtS SIOUX MO
01 PKTGE DES SIOUX MO
01 NEW MADRID
01 SIBLEY
02 SIBLEY
05 KISSICK
MO
MO
MO
MO
MO
MO
MO
MO
MO
MO
MO
MO
MO
05
07
01
5
5
05
05
A
53
54
59
72
73
71
70
66
67
72
55
62
70
125
125
253
5BO
580
oOO
600
488
488
600
50
50
112
C G
C G
C G
C
C
C
C
C
C
C
CB
ca
C G
12175
12175
12175
11200
11200
11200
11200
10975
10*75
12066
12041
liJ41
.8
.8
.8
11.3 2.9
11.3 2.9
11.3 2.9
11.3 2.9
2.7
2.7
4.8
3.7
3.7
3.1
3.1
3.1
3.2
3.2
3.2
3.2
3.7
3.7
5.0
3.9
3.9
11.7
11.7
11.7
9.9
9.9
9.9
9.9
12.8
12.8
10.7
10.7
72
73
71
70
74
74
72
72
75
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
RC
RC
RC
RC
RC
RC
RC
RC
RC
UP
UP
UP
UP
97.5
97.5
97.5
99.5
99.5
99.5
99.5
99.6
99.6
97.5
99.0
99.0
99.0
FS CE
BE
BE
BE
BE
BM
UNION ELEC.
MERAMEC
04 SE ST. LOUIS MO 07 61 300 C G 12175
.8 3.1 11.7
PE UP 97.5
SUBTOTAL
ALL UNITS —
16
— COAL — OIL —— — GAS '—- —NUCLEAR—
MM UNITS MM UNITS MU UNITS MM UNITS MM
6,031 it> 6*031
-------
DATE RUN 12/2<»/75
ELECTRIC UTILITY 1>ATA
PAGE NO 20
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE - MP
UNIT F u E L —PARTICULATE— —S02
UN LOCATION SliE TYPE HEAT PCT SULF-PCT PCT TV PCT R TV CON
IT CITY ' ST HO YR M* I 2 BTU MOIS HlN MAX ASH YR PE MFR EFY V YR PE MFR SLT
UTILITY CO. NAME
MISSISSIPPI PWR.
MISSISSIPPI PwR.
PLANT NAME
WATSON JACK
NATSON JACK
o«« GULFPORT
05 GULFPORT
MP
MP
05 68
250 C
505 C
11809
11609
2.9 2.9
2.9 2.9
68 PE MP 96.0
PE UP 99.0
SS
SU3TOTAL
— ALL UNITS
— COAL —• OIL — GAS —NUCLEAR—
MM UNITS MU UNITS MM UNITS MM UNITS MM
755 2 755
N>
-------
DATE RUN 12/2V/75 ELECTKIC UTILITY DATA PAGE N0 2l
LIST OF UNITS INSTALLED THkuUGH 1975 dY STATE
STATE .= MT
UNIT -F- U 6 L —PARTICULATE— —S02
UN LOCATION SUc TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
UTILITY Cl>. NAME PLANT NAME IT CITY ST Mo YR MM 1 i BTU HOIS MIN MAX ASH YR PE HFR EFY Y YR PE MfR SLT
MONTANA f'Wu. c^Kl I T fc J.t. 01 OILLlNCS MT 68 173 CS 86*3 25.2 .7 .7 8.* 68 PE 95.0
ALL UNITS —< — COAL — — OIL — GAS —NUCLEAR
MU UMTS MW UNITS HU UMTS HU UNITS MU
1 173 1 173
-------
QATc «U.V 12/24/75
ELECTRIC UTILITY. DATA
PAGE NO iZ
LIST OF UNITS
STATE = NB
INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
OMAHA PUB. Prfft.
OMAHA PUB. PriR.
OMAHA PuB. PrfR.
OMAHA PUB. P*R.
OMAHA PUS. PrfR.
SUBTOTAL
PLANT NAME
N. OMAHA
N. OMAHA
N. OHAHA
N. OMAHA
N. OMAHA
U £ L- —PARTICULATE— —S02
TY CON
YR PE HFR SLT
UN
IT
04
05
01
03
02
L 0 C A T I 0
CITY
OMAHA
OMAHA
OMAHA
OMAHA
OMAHA
.••.••.» All 1 1NJ 1 T C
«.«,.... Mi.*. UN i 1 3
N
ST
NB
NB
NB
NB
NB
SUE TYPE
MO YR
ol
68
54
59
57
MM 1
102 C
235 C
102 C
102 C
102 C
2
G
G
G
0
G
HEAT
6TU
10300
10300
10300
10300
10300
PCT
MOIS
12.0
12.0
12.0
12.0
12.0
SULF-PCT PCT
HIM
.3
.3
.3
.3
.3
„ - /-ri.i i-» I » —
MM
VrWMl.
UNITS
MM UNITS
MM
MAX ASH
.9 6.0
.9 6.0
.9 6.0
.9 6.0
.9 6.0
TY
YR PE
74 PE
74 PE
74 PE
74 PE
74 PE
-— — GAS — —
^^^ W^l v
UMTS MM
PCT R
MFR EFY Y 1
BU 99.4
BU 99.4
bU 9Vi.4
BU 99.4
BU 99.4
—NUCLEAR—
*» W W Iv %»P^'»
UNITS MM
NJ
-------
DATE RUN 12/2V75
LIST OF UNUS INSTALLED THROUGH 1975 BY STATE
STATfe * NC
ELECTRIC UTILITY DATA
UTILITY CO. NAME
CAROLINA PhR & LT LEE H.F
UNIT F U E L
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT
PLANT NAME IT CITY ST MO YR Mh 1 2 BTU MOIS MIN MAX ASH
—PARTICULATE—
TY PCT R
YR PE MFR EFY Y
DUKE POWER CO.
MARSHALL
02 GOLDSBOKO NC 51 66 CB 0 12753 5.8 .8 2.2 8.6 73 ME 99.2
02 TERRELL NC 66 386 C6 0 11657 7.4 .8 3.0 16.3 70 ME AT 99.0
CAROLINA PKR & LT
CAROLI \A PwR u -LT
CARuLliNA PWR L LT
CAnuLlNA Pxri & LT
Ci^bLINA PWP. i. LT
CArvL^I.iA PKS i. LT
OUKE POWER CO.
DUKE POKER CJ.
CUK; POKES cj.
DUKE POwER CJ.
DUKE POKER CO.
OUKE POWER CJ.
DUKE POWER CJ.
t> OUf.6 PunER CO.
' DUKc POWER CO.
j^ DUNE PoWEA CO.
CAfsLLINA ?nR £ LT
CAROLINA PwR i LT
CARC^IMA PKR tl LT
CAKuuI^A P«« i LT
CAKt'_Ir
14J CB
143 CB
76 C
38 C
109 C1*
137 C
38 CB
36 CB
133 C
193 CB C
63 CB (j
63 CB G
220 CB
llf C 0
290 Cd
169 Cd
2d7 Cd
76 CB
76 CB
, f ca
66 Co
66 Cd
268 CB
170 CB
o7l CB 0
6bO CB 0
575 Cd
1144 C
12641
12o41
12185
12133
12268
12268
12050
12050
12050
1220o
12206
12050
12206
12530
12530
12206
11820
12753
126tl
12753
12133
12161
12161
121ol
12263
12263
12530
12161
12161
11657
11657
12530
5.6
5.6
5.5
7.0
4.6
4.6
5.9
5.9
5.9
7.4
7.4
5.9
7.4
6.4
6.4
7.4
7.2
5.8
5.6
4.0
7.0
6.8
6.3
6.8
7.0
7.0
6.4
6.3
6.8
7.4
7.4
0.4
.7 1.3
.7 1.3
.7 1.5
.7 1.4
1.0 2.5
1.0 2.5
.6 3.2
.6 3.2
.6 3.2
.6 1.5
.6 1.5
.6 3.2
.6 1.5
.6 1.6
.6 1.6
.6 1.5
.6 2.4
.6 2.2
.7 1.3
.8 2.2
.7 1.4
.7 1.0
.7 1.0
.7 1.0
.6 1.5
.6 1.3
.6 1.6
.7 1.0
.7 1.0
.8 3.0
.8 3.0
.6 1.6
.8 .8
13.0
13.0
16.0
12.1
12.0
12.0
17.5
17.5
17.5
11.9
11.9
17.5
11.9
It. 2
14.2
11.9
12.3
d.6
10.0
14.0
12.1
11. 6
11.8
11.6
16.3
16.3
1 f. J
i*f *£.
14.2
11.8
11.8
16.3
16.3
14.2
73 ME
73 ME
73 ME
73 HP
72 PE
72 PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
71 PE
73 Mt
73 ME
73 ME
72 HP
HP
ME
HP
HP
HP
WO
nr
HP
HP
ME
70 PE
69 PE
PE
73 ft
BU 99.3
BU 99.3
BU 99.5
BU 99.5
BU 99.6
BU 99.6
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
BU 99.0
RC 99.0
RC 99.3
KC 99.3
RC 99.4
RC 99.5
RC 99.0
RC 99.0
RC 99.0
RC 99.0
RC 99.0
RC 9^« 0
RC 99.0
RC 99.0
RC 99.0
RC 99.5
RC 99.5
RC 99.5
RC 99.7
PAGE NO 23
—S02
TY CON
YR PE MFR SLT
E6
EB
BR
BE
01
-------
DATE RUN 12/24/75 ELECTRIC UTILITY DATA PAGE NO 2*
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
UNIT ------ f U E L ----- — PARTICULATE — — $02 --
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
UTILITY CO* NAME PLANT NAME IT CITY ST MO YR MW I 2 BTU MOIS MIN MAX ASH YR PE MFR EFV Y YR PE MFR SLT
DUK£ POWER CJ. BELEWS CREEK 01 W INSTQN-SALEM NC 74 11*4 C .8 .8 73 PE RC 99.7 0*
CAROLINA PWR £ LT SUTTON LOUIS V. 03 WILMINGTON NC 72 420 C 0 12133 7.0 .7 1.4 12.1 73 PE UP 99.0
CAROLINA PWR C LT ROXBORO 03 ROX3URO NC 3 73 720 CB 12268 4.6 1.0 2.5 12.0 73 PE UP 99.0
--- ALL UNITS ---- — COAL --- — OIL - — GAS -- — NUCLEAR --
MM UNITS MW UNITS MM UNITS HU UNITS MW
SUBTOTAL 39 10,238 39 10,238
Ul
-------
DAIL RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 25
LIST OF UNITS
STATE * NO
INSTALLED THKGtHSH 1575 BY STATE
UTILITY CO. NAME
BASIN EL PWR CO-JP
MINNK.OTA COOP
MONTANA-DAKOTA UTIL.
UN
IT
PLANT NAME
LELAND OLOS 01 STANTGn
YOUNG, MILTON K 01 CENTER
LOCATION
CITY
HESKETT R.M.
MONTANA-DAKOTA UTIi_. HESKETT R.M.
UNITED POWER ASSOC STANTON
01 MAMOAN
02 MANOAN
01 STANTON
N
ST MO YR
NO
NO
NO
NO
NO
62
70
50
63
67
UNIT
SIZE
M*
216
235
25
75
150
TYPE
1 2
CL
CL 0
CL G
CL
CL
HEAT
dTU
6061
6370
6975
6975
7032
U E L
PCT SULF-PCT PCT
MG1S
37.6
3d. 5
36.1
36.1
MIN MAX
.7 .6
.5 1.3
.3 1.4
.3 1.4
.4 .9
ASH
12.1
a. 5
6.7
6.7
6.9
— P ARTICULATE — — S02
TY PCT R TY CON
YR PE
73 PE
73 PE
73 ME
73 ME
74 PE
MFR EFY Y YR PE MFR SLT
RC
RC
RC
RC
RC
99.5
99.0
99.5
99.5
98.0
bQ
SP
SR
SR
0V
BASIN EL PMR CO-OP LELAND OLOS
02 STANTON
NO 10 75 450 CL
73 PE UP 99.5
SUBTOTAL
ALL UNITS
—•• — COAL — OIL
MW UNITS MM UNITS
1,151 6 1.151
— — GAS —
UNITS MM
—NUCLEAR-
UNITS MM
-------
CATt RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 26
LIST OF UNITS
STATE =. NJ
INSTALLED THROUGH 1975 BY STATE
UTILITY CC. NAME
ATLANTIC CTY cLEC
ATLANTIC CTY ELEC
ATLANTIC CTY cLEC
ATLANTIC CTY cLEC
PUBLIC SERV. E&li
PUBLIC SEriV. EtG
PUBLIC
PLANT NAME
ENGLAND 6.L.
ENGLAND o.L.
MISSOURI AVc
MISSOURI AVE
«£RC£S
MERCER
HUDSON
UNIT
UN LOCATION
IT C I T
01 BEESLEYS
02 BEtSLtYS
07 ATLANTIC
06 ATLANTIC
02 HAMILTON
01 HAMILTON
Y
pr.
PT.
CITY
CITY
TwP
THP
02 JERSEY CITY
ST
NJ
NJ
NJ
NJ
NJ
NJ
NJ
MC YH
62
6H
46
41
59
58
69
SUE
«K
125
150
25
15
320
320
600
TYPE
1 I
C3 0
Cd 0
C
C
CB 0
CB 0
C 0
— f
HEAT
BTU
12064
12004
13653
13653
12S37
12B37
12156
U E L
PCT
M01S
3.5
3.5
5.7
5.7
5.7
5.7
SULF-PCT PCT
MIN
2.0
2.0
.5
.5
.9
.9
.9
MAX
5.0
5.0
.5
.5
2.4
2.4
2.1
ASH
15.0
15.0
6.8
6.6
11.6
11.6
12.1
— PART1CULATE-
TY
YR PE
PE
PE
46 PE
41 PC
69 PE
69 PE
68 PE
PCT
MFR EFY
9fl.O
99.5
RC 95.0
RC 95.0
RC 99.0
RC 99.0
RC 99.5
- — soz—
a TV CON
Y YK PE MFR SLT
K>
SUBTOTAL
ALL UNITS — COAL — OIL — GAS —NUCLEAR"
MU UNITS MM UNITS MW UNITS MM UNITS MM
1,565 7 1.565
-------
DATE RUN 12/2t/75
ELECTRIC UTILITY DATA
PAGE NO 27
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = NM
UTILITY CO. NAME
P.S. OF NEW MEXICO
PLANT NAME
SAN JUAN
UN
IT
LOCATION
CITY
02 HATERFLOH
UNIT F U E L
SUE TYPE HEAT PCT SULF-PCT PCT
—PARTICIPATE— —S02-
TY
PCT R
TV
CON
ST MO YR
NM 73
Mti 1 2
3
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 28
to
LIST OF UNITS INSTALLED THROUGH 1*75 BY STATt
STAT E = NV
UTILITY CO.
SOUTHERN CAL ED.
SOUTHERN CAL tO.
SUBTOTAL
PLANT NAHE
HOHAVt
MOHAVE
UN
IT
01
02
L 0 C A T I 0
CITY
2
N
ST
NV
NV
MO YR
71
71
MM
1.580
UNIT F
SIZE TYPE HEAT
Mrf 1 2 6TU
790 CS G
790 CS G
— COAL
UNITS
2 1.
10774
10774
MM UN;
r580
U E L
PCT SULF-PCT PCT
MOIS HIN MAX ASH
.4 .8 10.9
.4 .8 10.9
—PARTICULATE— —502
TY PCT R TY CON
YR PE MFR EFY Y YR ?E MFR SLT
70 PE RC 98.6
71 Pt HC 98.6
OH
OH
BE
BE
— GAS —
MW UNITS MW
—NUCLEAR-
UNITS MM
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 2S
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
iTATE = NY
•
UTILITY CO. NAME
N.Y. STATE EL.6G.
N.Y. STATE EL.iG.
N.Y. STATE EL. £5.
N.Y. STATE EL.SG.
N.Y. STATE Ei_.tG.
ORANGE RQCKLANJ UTIL
ORANGE ROCKLANO UTIL
N.Y. STATE tL.tG.
K,, N.Y. STATE EL.tG.
1 N.Y. STATE EL.tG.
W NIAGARA MOHAWK PWR.
° NIAGARA MOHAWK PWR.
NIAGARA HGHA^K P*R.
NIAGARA rtGHAUK l>dR.
NlAGi*A KUHAWK PUR.
NIAGARA MGHArfK PWR.
NIAGARA MJHA4K PMR.
NIAGARA MOMAriK PHR.
PLANT NAME
GOUjY
GREENIOGE
GREENIOGE
MILL I KEN
GREeUIDGE
LOVtTT
LOVETT
GOUDY
GOUDY
GOUDY
DUNKIRK
DUNKIRK
HUNTLEY C.R.
DUNKIRK
HUNTLEY C.R.
HUNTLEY C.R.
DUNKIRK
HUNTLEY C.R.
UN
IT
05
02
03
02
04
04
05
06
07
08
01
03
68
04
fc7
65
02
66
L 0 C
A T
CITY
JOHNSON
DRESDEN
DRESDEN
CTY
LUDLOhVlLLE
DRESDEN
TOKKINS
TOMKINS
JOHNSON
JCHNSCN
JOHNSON
DUNKIRK
DUNKIRn
BUFFALO
DUNKIRK
BUFFALO
BUFFALO
DUNKIRK
BUFFALO
COVE
COVE
CTY
CTY
CTY
1 i t\l
UNIT F U E L —PARTICULATE— —S02
N SI7E TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
ST MO YR M* 1 1 BTU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE MFR SLT
NY
35
12 C
12048 4.8 1.7 4.1 18.7
PE
99.8
SU6TOTAJ.
18
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
NY
43
48
58
52
66
6V
39
47
50
50
59
58
60
57
53
50
54
- ^
MM
2,175
20
40
135
dO
199
202
30
44
60
109
2
-------
DATE KON 12/24/75
ELECTRIC UTILITY OATA
PAGE NO 30
u>
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATc = QH
UTILITY CO. NAME
CHIU POWER
OHIO POWER
OHIO POHER
OHIO EDISON
OHIO POWER
OHIO POWER
OHIO EDISON
CINCINNATI G&E
CINCINNATI G&c
CINCINNATI G6,c
COcUMbUS C S. OHIO E
COtUMoUS t S. OHIO c
COLUMBUS 6 S. OHIO E
CHIU EDISON
OHIO EDISON
OHIO EDISON
OHIO EuISON
OHIO EDISON
OnIO tDISON
OHIO EDISON
OHIO POWER
OHIU POWER
CINCINNATI G£E
CINCINNATI Gtc
CINCINNATI G£E
CLEVELAND ELSC ILLUM
CLEVELAND ELEC ILLUM
COLUMoUS &S. OHIO E
DAYTON PWR t LT
DAYTON PwA t LT
DAYTON PWR £ LT
DAYTON PWR i LT
DAYTON PWR 6 LT
DAYTON PWR 6 LT
SAMMIS M.H.
BECKJOSD w.C.
STUAHT J.M.
MIAMI FORT
STUART J.M.
STUART J.rt.
STJART J.M.
SAMMIS W.H.
SAMMIS w.H.
SAMMIS W.H.
SAMMIS W.H.
TORONTO
TORONTO
TORONTO
GAVIN
GAVIN
BECKJO*D W.C.
BECK.JGRD W.C.
BECKJORD W.C.
EAST LAKE
cASTLAKE
CGNcSVILLE
HUTCHINGS O.H.
HUTCHINGS O.H.
TAIT P.M.
HUTCHINGS O.H.
HUTCHINGS O.H.
HUTCHINGS O.H.
UN LOCATION
IT CITY
06 PHJLO
04 PMILO
05 PMILO
01 SHADYSIDE
02 BRILLIANT
01 BRILLIANT
05 STRATTON
05 NE« RICHMOND
U~ AbERDiiE.*
05 NORTH oEND
02 ABERDEEN
03 ABERDEEN
01 ABERDEEN
Q<- STRATTON
03 STRATTCN
02 STRATTGN
01 STRATTON
05 TORONTO
06 TORONTO
07 TORONTO
01 GALLIOPOLIS
02 GALLIOPOLIS
02 NEw RICHMOND
01 NEW RICHMOND
03 NEW RICHMJNO
04 EAST LAKE
05 EASTLAKE
04 CONESVILLE
05 MIAMISBiMG
06 MlAMIScJURG
04 DAYTON
04 MIAHISBURG
03 MIAMISBURG
02 MIAMIS6URG
ST
OH
On
OH
OH
OH
OH
OH
UH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
Ori
OH
OH
OH
OH
OH
OH
OH
OH
OM
MO YR
57
42
42
44
48
45
67
62
74
56
70
03 72
71
62
61
t>0
59
40
49
49
10 74
10 75
52
49
55
56
8 72
1 73
58
UNiT
SUE
HW
125
03
65
63
111
105
318
246
580
90
560
580
580
185
185
185
185
44
66
66
1380
1380
101
98
128
208
625
744
70
70
136
70
70
63
TYPE
i ^
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
C 0
c
c
CB
ca
ca
CB
CB
CA
HEAT
BTU
10679
10679
10679
11700
11635
11635
11563
10637
1123o
11272
11206
11206
11206
11503
11563
11563
115o3
10515
10515
10515
10687
10687
10667
11921
11921
10B22
12360
12360
11915
12360
12360
12360
U t L
PCT SULF-PCT PCT
HOIS MIN MAX ASH
1.8 5.7
l.d 5.7
1.8 5.7
7.5 1.2 4.3 16.2
2.6 3.3
2.6 3.3
7.1 .7 4.0 17.7
d. 8 1.0 5.5 17.7
.6 .6 50.1
9.5 1.0 4.6 13.9
7.5 .6 5.0 15.4
7.5 .6 5.0 15.4
7.5 .6 5.0 15.4
7.1 .7 4.0 17.7
7.1 .7 4.0 17.7
7.1 .7 4.0 17.7
7.1 .7 4.0 17.7
8.1 1.8 3.5 16.0
3.1 1.8 3.5 16.0
8.1 1.8 3.5 16.0
1.0 3.0 20.0
1.0 3.0 20.0
8.8 1.0 5.5 17.7
8.8 1.0 5.5 17.7
6.8 1.0 5.5 17.7
7.0 .5 4.2 13.9
7.0 .5 7.1 13.9
3.0 5.1
5.9 .6 1.0 9.9
5.9 .6 1.0 9.9
6.9 .7 2.3 11.9
5.9 .6 1.0 9.9
5.9 .6 1.0 9.9
5.V .6 1.0 9.9
TY PCT ft
YR
71
74
72
75
72
72
72
70
70
70
72
72
72
72
72
73
73
73
73
73
73
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
ME
PE
PE
HP
HP
HP
HP
HP
HP
MFR EFY Y
AS
BU
au
BU
BU
BU
BU
BU
BU
BU
BU
au
BU
BU
KC
KC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
98.3
99.0
99.0
99.0
99.4
99.4
99.0
98.0
98.0
99.5
98.0
96.0
98.0
97.0
97.0
97.0
97.0
99.0
99.0
99.0
99.7
99.7
99.0
99.0
99.5
95.0
99.5
99.3
99.5
99.5
99.5
99.5
99.5
99.5
TY CON
YR PE MFR SLT
PI RC
EB
SL
Efl
EB
EB
AP
AP
—
GA
BV
.
-------
DATE RUN 12/24/75
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
DAYTON PHR £ LT
tiAYTON PHR £ LT
COLUMBUS £ S. OHIO
COLUMBUS £ S. OHIO
CQLU.13US £ S. OHIO
CJLUM3US £ S. OHIO
CCLUMdUS £ S. OHIO
COLU'WUS £ S. OHI.O
CCLUMbUS £ S. OHIO
COtU'-WuS £ S. OHIO
OHIO EDISON
OHIO EDISON
OHIU EDISON
OHIO £01 SON
^ OHIO eDISCN
1 OHIO POi/ER
U) OHiu POWER
^ UHIO 6DISON
OHIO EDISON
CHIO tOtSON
OHIO EDISON
OHIO tuISON
OHIO EDISON
OHIO PJHER
OHIO PO«ER
CHIC POWER
OHIO POWER
OHIO POWER
PLANT NAME
HUTcHINGS O.H.
TAIT P.M.
E POSTON
E POSTON
E POSTON
E CONcSVILLE
E COMcSVlLLE
c POSTON
E COUESVILLE
E PICdAY
UURGER H.E.
BURjEk R*E.
GORGE
GORGE
EOGEwATER
MUSKINGUM RIVER
MUSKINGUM RIVER
BURGER R.E.
EuGEWATER
EOGc^ATER
BURGER R.E.
SAMMIS W.H.
SAMMIS
CARDINAL
MUSKINGUM RIVER
CARDINAL
MUSKINGUM RIVER
MUSKINGUH RIVER
UN L 0 C A
IT CITY
Oi MIAMISBURG
05 DAyTON
04 ATHENS
03 ATHENS
02 ATHENS
02 CCNfcSVlLLE
03 CONESVlLLE
01 ATHENS
01 CONESVlLLE
05 COLUMBUS
05 SHADYSIDE
Q-* SHAOYSIOt
06 AKKUN
07 AK.RON
04 LORAIN
04 BcVcRLY
03 tJtVERLY
02 SHADYSIDE
03 LOrtAIN
02 LOftAIN
03 SHADYSIOE
06 STRATTUN
07
02 BRILLIANT
05 BEVERLY
01 BRILLIANT
02 BEVERLY
01 BEVERLY
iNCINNATI G&E
MIAMI FORT
07 NORTH BEND
ELECTRIC UTILITY DATA
UNI T F U E L
N SUE TYPE HEAT PCT SULF-PCT PCT
ST MO YR MM 1 2 BTU MOIS MIN MAX ASH
OH
OH
CH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
OH
CH
OH
CH
OH
OH
OH
OH
OH
OH
OH
—PARTICULATE—
TY PCT R
YR PE MFR EFY Y
59
58
62
59
0
160
44
4<»
105
225
225
63
63
7
100
623
625
590
591
590
213
213
ca
cu
CB
ca
CB
Cfl
Cb
C6
CB
C8
C
C
C
C
C
C
C
C
C
C
C
C
C
CB
C
ca
c
c
12360
11915
11178
11178
11174
10322
10«22
11173
10822
11279
11700
11700
10V12
10912
12122
10531
10531
11700
12122
12122
11700
11563
11012
11867
10531
11867
10531
10531
5.9
6.9
9.5
9.5
9.5
7.V
7.9
9.5
7.9
8.2
7.5
7.5
7.1
7.1
6.1
7.5
6.1
6.1
7.5
7.1
.6
• 7
2.1
2.1
2.1
3.8
3.8
2.1
3.U
2.9
1.2
1.2
1.6
1.6
1.3
1.4
1.4
1.2
1.3
1.3
1.2
.7
.5
.3
1.4
.3
1.4
1.4
1.0
2.3
4.2
4.2
4.2
5.0
5.0
4.2
5.0
5.2
4.3
4.3
4.2
4.2
4.2
5.U
5.8
4.3
4.2
4.2
4.3
4.0
4.1
3.6
5.8
3.6
5.8
5.8
9.9
11.9
12.2
12.2
12.2
15.9
15.9
12.2
15.9
17.9
16.2
16.2
16.9
18.9
16.8
16.2
16.8
16.8
16.2
17.7
15.4
15.0
15.0
.
73
73
75
75
75
75
75
75
75
75
71
71
69
69
70
70
71
70
70
71
69
71
67
66
67
70
70
HP
HP
ME
ME
ME
ME
ME
ME
ME
PE
ME
ME
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
RC
RC
UP
UP
UP
UP
UP
UP
UP
UP
MP
WP
HP
WP
WP
HP
HP
HP
WP
HP
HP
WP
HP
HP
HP
HP
HP
HP
99.5
99.5
99.0
99.0
99.0
99.0
99.0
99.0
99.0
99.0
97.0
97.0
98.0
98.0
93.0
98.5
98. 5
99.0
99.0
99.0
99.0
99.0
99.0
99.4
99.4
99.4
99.5
99.5
PAGE NO 31
TV CON
YR PE MFR SLT
75 500 C
71 PE WP 99.5
CA
SL
SL
SL
SUBTOTAL
-- ALL UNITS
63
MM
15,735
— COAL
UNITS MM
63 15,735
— OIL
UNITS
— GAS
HH UNITS
—NUCLEAR—
MH UNITS MM
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 32
CIST Q? UNITS
STATE = PA
INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
OUdUESNE LT.
METROPOLITAN EO
METROPOLITAN ED
METROPOLITAN EO
Pi. 5LiC.CC.
PA. TL^C.C'j.
PA.
PA.
PA. PsR.fi.LT.
PA. PHR.fiLT.
PHILADELPHIA ELEC
PHlC^JtLPHI A ct-EC
PHI L-WEcPHI A =L£C
PHlLACiC-LPHIA ELEC
LEC.CG.
PLANT NAME
ELRAMA
TITJS
TiTUS
TITL'3
S?rfu:> D
HCLr>-.OCD
SU^dlMY
S'JNiiiJRY
EOUYSTONE
UN
IT
03
03
02
01
03
02
Oi
01
02
01
02
C-l
02
01
L 0 C A T I
CITY
ELRAtfA
READING
REDOING
READING
VARRc.N
hA
to
METROPOLITAN EO
METROPOLITAN EO
N.Y. STATE EL.iG.
N.Y. STATE EL.66.
P4. ELEC.CO.
PA. EueC.CO.
FA. ?«.-,.<.
PA. P'/iR.iiLT.
PA. P«R.".LT.
PA. PAA.<.
liEST PENN PHR.
PORTLANO
PORTLAND
HOriSP. CITY
HOMER CITY
SHAMVILLE
SHA^VILLE
CONEy.AUviH
CONE^AUGH
SUN5URY
SUNSURY
SPRINGDALE
01 PGRTL^NO
02 PG.\TLAND
02 HO-'icR CITY
01 HO«ER CITY
03 SHAWVILL5
04 SHArtVILLt
02 NEW FLORENCE
01 N£:n FL3RE.MCE
04 SHMC.<;.x 0AM
03 SHA/GKiN DArt
OB SPRl.iGDALE
PA
PA
PA'
PA
PA
PA
PA
PA
PA
PA
PA
53
62
70
69
59
60
71
70
33
51
21
213
213
6^0
6^0
183
183
900
900
125
125
141
C
C
r
C
C
C
C \
C
C3
Ca
C
0
0
0
0
12044
12044
11659
11659
12428
12428
11394
113S't
11C3P
llOJii
13330
6.2
6.2
4.1
4.1
5.1
5.1
5.3
= ..*
3,6
5.6
4.5
.7
.7
.9
.9
1.4
1.4
.9
.9
.7
.7
1.5
3.6
3.6
2.5
2.5
2.3
2.6
4.6
4.6
5.4
5.4
2.1
l<-.3
1^.3
20.1
20.1
13.4
13.4
2U.3
20.3
3^.9
34.9
o.O
58
62
70
69
74
74
70
74
74
68
PE
PE
PE
PE
Fc
PE
M -=
fit
PE
dU
BU
su
6U
BU
BJ
SU
3D
SU
BSJ
BU
97.0
97.0
99.5
9S.5
9(3.5
96.5
99.5
99.5
99.6
99.6
96.0
GA
GA
GA
GA
DUdJcSNE LT.
OUJJESNE LT.
PA. P.
-------
DATE RUN 12/24/75
ELECTRIC UTILIIY DATA
PAGb NO 33
OJ
*>.
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
UTILITY CO. NAME
DUUUeSNE LT.
PA. ELEC.CG.
PA. ElEC.CO.
PA. ELEC.CO.
I'A. PWR.ELT.
PA. PWR.tLT.
f'A. PWx.GLT.
PUBLIC SERV. E6G
I'UtJLlC SERV. E£G
WSST PENN PwR.
WcST PENN PrtR.
WEST PtNK PMR. •
WEST PENN PWR.
PENN PHR.
DUaUESNE LT.
<>A. PrtR.CLT.
PA. P«R.<.
PLANT NAME
CHESHICK
SEMARD
FRONT ST.
SEHARO
BRUNNER ISLAND
BRUNNER ISLAND
BRUNNER ISLAND
KEYSTONE
KEYSTONE
HATF1ELDS FERRY
HATF1ELDS FERRY
HAT FIELDS FERRY
ARMSTRONG
ARMSTRONG
ELRAMA
MONT OUR
MONT OU ft
UN
IT
01
04
07
05
02
01
03
02
01
01
02
03
01
02
04
02
01
L 0 C A T I
CITY
SPRINGOALE
ERIE
YORK HAVEN
YORK HAVEN
YORK HAVEN
SHELOCTA
SHELOCTA
MASONTOWN
MASONTOWN
MASONTUWN
REESEDALE
REESEOALE
ELRAMA
OERRY THP
OERRY T»IP
0 N
iT
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
PA
MO YR
70
37
40
57
65
61
69
68 68
67 67
69
70
71
58
59
58
.73
3 72
umi i
SIZE
MW
570
29
17
137
390
330
750
444
4*4
5<-0
5^0
5<-0
163
le>3
165
750
750
TYPE
I 2
CB
C
C«
C
CB 0
ca o
ca c
C 0
C 0
C
C
C
C
C
CB
C
C
HEAT
bTU
10950
12124
12143
12124
12501
12501
12501
11956
11956
12445
12445
12445
11686
116S6
11041
12405
12405
PCT SULF-PCT PCT
MOIS
5.7
3.9
4.8
3.9
4.5
4.5
4.5
2.8
Z.d
4.0
4.0
4.0
4.0
4.0
5.S
5.0
5.0
MIN MAX
1.2 4«4
2.4 3.0
1.1 3.9
2.4 3.0
1.5 3.6
1.5 3.6
1.5 3.6
1.3 3.1
1.3 3.1
1.1 3.0
1.1 3.0
1.1 3.0
1.6 4.1
1.6 4.1
1.1 3.5
1.1 5.4
1.1 5.4
ASH
20.6
17.3
12.4
17.3
20.1
20.1
20.1
IB. 5
18.4
13. ti
13.6
13. B
16.7
16.7
19.3
13.4
13.4
TY PCT R
YR PE
73 PE
ME
74 P6
ME
65 PE
61 PE
69 PE
68 PE
67 PE
65 PE
PE
PE
73 PE
73 PE
SC
PE
PE
MFR
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
UP
UP
HP
WP
MP
cFY Y
99.5
97.0
98.0
96.0
97.3
9o.7
99. 5
99.5
99.5
99.0
99.0
9V. 0
99.5
99.5
99.0
99.5
99.5
TY CON
YR PE MFR SLT
SM
GA
GA
GA
UE
UE
UE
EB
EB
SUBTOTAL
ALL UNITS
50
— COAL — OIL — GAS —NUCLEAR—
MM UMTS MM UNITS MM UNITS MM UNITS MM
13.663 50 13,663
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 34
U)
Ul
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE - SC
UNIT F U E L
SUE TYPE HEAT PCT SULF-PCT PCT TY PCT R
UTILITY CO. NAME PLANT NAME IT CITY 5>T MC YR MH 1 2 B.J M01S MIN MAX ASH YR PE MFR EFY Y
CAROLINA PWR £ LT
DUKE POdER CO.
DUKE POKER CO.
DUKE POWER CO..
SOUTH CAROLINA
SuUTH CAROLINA
SOUTH CAROLINA
SOUTH CAiNULlNA
SOUTH CAROLINA
SOUTH CAROLINA
SOUTH CAROLINA
SOUTH CAROLINA
SOUTH CAROLINA
SOUTH CAROLINA
ME
LT
ECG
ESG
E&G
EtG
EdG
E&G
E&G
E6G
E&G
E&G
PLANT NAME
ROBINSON H.B.
LEE
LEE
LEE
CANAOYS
URCUHART
MC MEEK IN
USQJHART
CANAOYS
CANADYS
URQUHART
HAT6REE
WAT ERE E
MC MEEK IN
UN L 0 C A T I
IT CITY
01 HARTSVILLE
03 PELZER
02 PaZ£ft
01 PtLZcR
01 CANAOYS
03 3E6CH ISLAND
02 IAMO
02 &t£Cn ISLAND
02 CAUAQYS
03 CANAOYS
01 BccCM ISLAND
01 WATEREE
02 riATEREE
01 IKMO
0 N
5>T
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
SC
—PARTICULATE— —502
TY CON
YR PE MFR SLT
ALL UNITS —
60
56
51
51
62
56
58
53
0*
6?
53
70
71
58
185
169
104
103
127
100
125
75
127
200
75
375
385
125
__
CB 0
CB G
Ca G
CB G
CB G
CB G
CB G
ca G
Cb G
CB G
Co G
Cb 0
ca o
CB G
COAL
H UNITS
12550
11742
11742
11742
12<-70
12573
12476
12573
12-^70
12
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 35
LIST OF UNITS INSTALLED THROUGH 1975 dY STATE
STATE * SO
UTILITY CO. NAME
PLANT NAME
BLACK HILLS PHft & LT KIRK
BLACK HILLS Prift t LT KIRK
BLACK HILLS PrtR t LT KIRK
BLACK HILLS PJ* C i-T KlrtK
UN
IT
01
03
02
04
L 0 C A T 1
CITY
LtAJ
LEAD
LEAD
LEAD
0 N
ST
SO
SO
SO
so
um i
SUE
MO YR
32
39
36
40
MW
5
5
5
17
TYPE
1 2
CS
CS
CS
CS
HEAT
BTU
3045
8045
6045
8045
PCT SULF-PCT
MOIS MIN
• 3
.3
.3
.3
MAX
.4
.4
.4
.4
PCT
ASH
8.5
8.5
8.5
8.5
—PARTICULATE— —S02
TY PCT R TY CON
YR PE MFR EFY Y YR PE MFR SLT
75 PE RC 97.5
75 PE RC 97.5
75 PE RC 97.5
75 ME RC 97.5
OTTER TAIL PWR.
BIG STONE
01 BIG STONE
SO
75 440 CL
6200 42.0 .4 .9 6.5 72 PE WH 98.6
BE
U)
SUBTOTAL
ALL UNITS — COAL — OIL — GAS —NUCLEAR—
HW UNITS MU UNITS MW UNITS MW UNITS MW
5 <»72 5 472
-------
DATE RUN 12/24/75
LIST OF UNITS INSTALLED THROUGH 1975 BY STATc
STATE - TN
ELECTRIC UTILITY DATA
>
U,
UTILITY CO. NAME
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
TVA
PLANT NAME
GALLATIN
GALLAT IN
CUMBERLAND
CUMBERLAND
GALLATIN
GALLATIN
BULL RUN
JGHN5CKJVILLE
JOHNSO.lVlLLe
SEVIER JOHN
SEVIER JOHN
SEVIER JOHN
SEVIER JOHN
JOHMSONVILLE
WATTS BAR
WATTS BAR
WATTS BAR
WATTS BAR
SUBTOTAL
UN L 0 C A T I 0
IT CITY
04 GALLATIN
03 GALLATIN
02 CUMBERLAND CITY
01 CUMBERLAND CITY
01 GALLATIN
02 GALLATiN
01 CLINTON
06 NEh JOHNSQNVILL
09 NEW JUHNSONVILL
04 ROGfcRSVlLLE
02 RUGERSVILLE
01 ROGERSVILLE
03 ROGcftSVILLt
10 NEH JOHrtSUNVILL
03 WATTS bAR DAM
02 WATTS BAK 0AM
01 WATTS BAR 0AM
04 WATTS BAR QAM
ALL UNITS
18
N
ST
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
TN
_„
UNIT F U E L
SUE TYPE HEAT PCT SULF-PCT PCT
MO
Ob
05
11
06
06
01
Ob
10
09
07
02
Ob
02
02
03
04
-lmr_u 1—
YR
59
59
73
73
56
57
67
59
59
57
55
55
56
59
43
42
42
45
„-,_
MW
6,336
MW 1
328 CB
32 6 CB
1275 CB
1275 CB
300 CB
300 CB
950 CB
173 CB
173 C6
200 CB
200 CB
223 C49
9 11&49
10909
11617
11617
11617
11617
11 _M
MW UNITS
6,338
2.6
2.6
3.5
3.5
2.6
2.6
.9
3.4
3.4
.9
.9
.9
.9
3.4
1.3
1.3
1.3
1.3
OIL —
MW
MAX
4.6
4.6
4.5
4.5
4.6
4.6
1.9
4.2
4.2
3.4
3.4
3.5
3.5
4.2
4.2
4.2
4.2
4.2
.— .
ASH
15.5
15.5
15.5
15.5
I*..
13 '.4
13.4
16.1
16.1
16. 1
16.1
13.4
- GAS
— PARTICULATE —
TY PCT R
YR PE
70 ME
70 ME
73 PE
72 PE
70 ME
70 Me
75 PE
75 ME
75 ME
74 ME
74 Me
74 ME
7«. ME
76 ME
69 PE
69 PE
69 PC
69 PE
MFR EFY Y
AS
AS
AS
AS
BU
ttU
CA
LC
LC
LC
LC
LC
LC
LC
RC
KC
RC
RC
96.5
90.5
99.0
99.0
9S.5
96.5
99.0
96.5
9o.5
9t>.5
96.5
98.5
9*>.S
9b.S
95.0
95.0
95.0
95.0
— NUCLEAR—
UNITS KM
UNITS MM
PAGE NO 36
TY CON
YR PE MFR 5LT
TV
TV
-------
u>
00
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 37
LIST OF UNITS INSTALLED THRJUGH 1975 BY STATE
STATE = TX
UNIT F U E L —PARTICULAR— —S02
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
IT CITY ST MO YR MH 1 2 BTU MOIS MIN MAX ASH YR PE MFR hfY Y YR PE MFR SLT
UTILITY CO. NAMC
DALLAS PWR £ LT
DALLAS PMft & LT
PLANT NAME
BIG bftOKN
BIG 3ROWN
02 FAlHFjELO
01 FAIRFIELD
TX
TX
12 72
12 71
576 CL G
576 CL G
7000 30.8
7000 30.8
.6
.6
.6 10.4
.6 10.4
71 PE RC 93.0
71 PE RC 98.0
EB
EB
SUBTOTAL
ALL UNITS — COAL — OIL —
MM UNITS MM UNITS MM
1.152 2 1.152
—NUCLEAR--
UNITS MW UNITS MM
-------
DATE'RUN 12/2^/75
ELECTRIC UTILITY DATA
PAGE NO 36
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE - UT
UTILITY CO. NAME
UTAH PWR.SLT.
JTAH PnR.<.
PLANT NAME
CARBON
CARtJGN
UN
IT
02
01
•T
oo
SUBTOTAL
UN
IT
02
01
L 0 C A T I 0
CITY
CASTLE GATE
CASTLE GATE
ALL UNITS
2
N
ST
UT
UT
^»*>»«
MO YR
57
MH
166
vni i
SIZE TYPE
MW 1 2
100 CS
66 CS
— COAL
UNITS
2
r
HEAT
BTU
12165
12165
MM UN
166
U E L
PCT SULF-PCT PCT
—P ARTICULATE— —S02-
TY
PCT R
TY
CON
BTU MQIS MIN MAX ASH YR PE MFR EFY Y YR PC HFR SLT
.5 .6
.5 .6
75 ME BE 97.0
73 HE 6E 97.0
— OIL -- — GAS
MW UNITS MW
— NUCLEAR—
UNITS MH
-------
DATE RUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO 39
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = VA
UNIT f U E
UN LOCATION SUE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY COM
PLANT NAME IT CITY ST MO YR MX I 2 BTU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE HFR SL T
—PARTICULATE— —S02-
UTILITY CO. NAME
APPALACHIAN PWft
APPALACHIAN PWR
APPALACHIAN
APPALACHIAN
APPALACHIAN
P*R
GLEN LYN
GLEN LYN
CLINCH
CLINCH
CLINCH
RIVER
RIVcR
RIVcR
05
06
01
03
02
GLEN LYN
GLfciM LYN
CLEVELAND
CLEVELAND
CLEVELAND
VA
VA
VA
VA
VA
44
57
58
58
58
111 CB
225 Cfl
223 CB
223 CB
223 CB
12232
12232
11839
11839
11839
.5
.5
.5
.5
.5
2.7
2.7
2.6
2.6
2.6
72 PE
72 PE
72 PE
72 PE
72 PE
AS 99.4
AS 99.4
KC 99.7
KC 99.7
KC 99.7
POTOMAC ELEC PWR
POTOMAC ELEC P^R
PuTOMAC ELtC PWR
PuTCIAC cLcC PrfR
POTOMAC ELEC PWR
VIRGINIA EL.&PrfR.
VIRGINIA EL.bPriR.
POTOMAC RIVER
POTOMAC RIVER
PCTGMAC RIVER
PuTuMAC RIVES
POTOMAC RIVER
BREMO
BREMO
01 ALEXANDRIA
02 ALEXANDRIA
03 ALEXANDRIA
04 ALEXANDRIA
05 ALEXANDRIA
04 BREMO BLUFr
03 BREMO BLUfF
VA
VA
VA
VA
VA
VA
VA
49
50
54
56
57
56
52
95
95
I OB
108
108
170
60
CB 0
Cd u
C6 0
CB 0
CB 0
C C
C 0
13099
1J099
ij099
1J09S
13099
1272b
12728
4.3
<*.8
4.tt
4.3
4.8
.6
.6
.6
.6
.6
.7
.7
1.3
1.3
1.3
1.3
1.3
2.2
2.2'
17.5
17.5
17.5
17.5
17.5
75
75
75
71
71
HE HP
ME WP
ME MP
ME UP
ME kP
PE WP
PE MP
99.3
99.3
99.7
99.7
99.7
99.3
99.3
BE
BE
BE
BE
BE
SUBTOTAL
ALL UNITS
12
MM
1,749
UNITS
12
MH
,749
— OIL — GAS —NUCLEAR-
UNITS MM UNITS MU UNITS MM
-------
UATt RUN
ELECTRIC UTILITY DATA
PAGE NO 40
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = MA
UTILITY CO. NAME
PACIFIC PMR £ LT
PACIFIC PWR & LT
SU8TOTAL
UN L 0 C A T I u
PLANT NAME IT CITY
CENTKALIA
CENTRALIA
01 CeNTRALIA
02 CENTRALIA
ALL UNITS
Z
N
ST MO YR
MA 73
MA 73
MM
It400
UNIT —. 1- U C L
SIZE TYPE HEAT PCT SULF-PCT PCT
HH 1
700 CS
700 CS
2 0TU MOIS MIN MAX ASH
8100
8100
.4
.4
— COAL — OIL
UNITS
Z
MM UNITS
If 400
MM
.7
.7
— GAS
UNITS
TY
YR PE
73 PE
73 PE
iji,ui.«ie— ju*.
PCT R TY
CON
MFR ErY Y YR PE MFR SLT
LC
LC
99
99
.0
.0
BE
BE
— NUCLEAR
MW
UNITS
MM
-------
DATE HUN 12/24/75
ELECTRIC UTILITY DATA
PAGE NO
LIST OF UNITS INSTALLED THKOUGH 1975 aY STATE
STATE - Wl
NJ
UTILITY CO. NAME
WISCONSIN
WISCONSIN
WISCONSIN
WISCONSIN
WISCONSIN
WISCONSIN
EL.PWR
EL.PWR
EL.PWR
EL.PWR
EL.PWR
PWR. t LT.
MAO I SON G&E
wISCu'MS IN
kliCONSIN
W1SCUNS IN
WISCONSIN
WiSC CMS IN
WISCONSIN
nlSCGiMS IN
WISCONSIN
WISCONSIN
WISCONSIN
WISC'-iNsIN
KiSC j:JSlN
WJSCJNS IN
WISCONSIN
WISCONSIN
wl SCONS IN
WISCONSIN
WISCONSIN
WISCONSIN
WISCONSIN
WISCONSIN
EL.PWR
EL.PWR
fcL.PwR
bL.PWR
EL.PWR
EL.PWR
IL.PWR
P.S.
P.S.
P.S.
P.S.
PWK. 6, LT.
PWK. L LT.
PWR. L LT.
PWR. 6 LT.
PWR. t LT.
PWR. 6 LT.
EL.PWR
CL.PWR
P.S.
P.S.
PLANT NAME
PORT WASHINGTON
PORT WASHINGTON
PORT WASHINGTON
PORT WASHINGTON
PORT WASHINGTON
EDGEwATER
BLOJNT ST.
S.OAK CREEK
VALLEY
S.OAK CREcK
S.OAK CREEK
VALLEY
N. OAK CREEK
N. OAK CREEK
PULL I AM
PULLIArt
PULLIAM
PULLIA*
ROCK RIVER
RUCK RIVER
NELSON OEWtY
NELSON OEWEY
COLUMBIA
EOGEwATER
S.OAK CREEK
S.OAK CREEK
WESTON
WESTON
UN
IT
01
05
02
04
03
04
07
03
02
OS
05
01
02
01
06
05
04
03
02
01
02
01
01
03
07
Oo
02
01
LOCATION
CITY
P. WASHINGTON
P. WASHINGTON
P. WASHINGTON
P. WASHINGTON
P. WASHINGTON
SHEBOYGAN
MADISON
OAK CKEEK
MILWAUKEE
OAK CREcK
CAK CScEK
MILWAUKEE
OAK CREEK
OAK CREEK
GKEfcN BAY
GREEN BAY
GRctN 6AY
GREEN BAY
BELOIT
BfcLOIT
CASSVILLE
CASSVILLE
PORTAGE
SHEBUYGAN
OAK CREEK
UAK CREcK
ROTHSCHILD
ROTHSCHILD
ST
ml
Wl
WI
Wl
WI
WI
WI
wl
wl
Wl
Ml
Nl
hi
wl
Wl
Hi
Wl
M
WI
WI
wl
WI
Wl
WI
WI
wl
WI
wl
UNIT F
SIZE TYPE HEAT
MO YR M» 1 2 falU
U E L —PARTICULATE— —S02
PCT SULF-PCT PCT TY PCT R TY CON
HOIS M1N MAX ASH YR PE MFR 6FY Y YR PE MFR SLT
35
35
35
35
35
69
70
55
o9
o7
59
68
52
52
54
49
44
39
55
5-t
62
59
6 75
51
65
bl
49
40
60
80
ao
BO
80
225
50
3oO
140
336
275
140
120
120
63
50
30
30
75
75
100
100
466
60
313
275
75
60
C
C
C
C
C
C
C
C3
C
C
C
C
CB
CB
C
C
C
C
C
C
C
C
C
C
C
C
C
C
0
G
C
G
0
C
G
G
G
G
G
G
12940
12990
12990
12990
12990
10763
11669
H6jy
11949
11639
11639
11949
11639
11639
11819
11619
11619
11819
11447
11447
10637
10837
107o3
11639
11639
11585
11585
7.9
8.5
8.5
11.0
11.0
7.7
7.7
7.7
7.7
26.5
26.5
1.9
1.9
1.9
1.9
1.9
1.6
1.3
.3
1.3
.i
.3
1.3
.3
.3
.9
.9
.9
.9
1.0
1.0
1.0
1.0
.5
1.6
.3
.3
2.1
2.1
4.4
4.4
4.4
4.4
4.4
4.6
4.2
3.9
3.7
3.9
3.9
3.7
3.9
3.9
4.1
4.1
4.1
4.1
4.4
4.4
4.1
4.1
2.9
4.6
3.9
3.9
8.0
8.0
10.9
11.9
11.9
11.9
11.9
9.0
8.4
11.2
11.5
11.2
il.2
11.5
11.2
11.2
12.6
12.6
12.t>
12.6
9.0
9.0
10.0
10.0
9.0
9.0
11.2
11.2
69
74
66
69
67
59
68
70
70
72
72
72
72
72
71
72
72
74
72
71
71
71
71
P6
PE
PE
PE
PE
PE BU
PE RC
PE RC
PE RC
PE RC
PE RC
PE RC
PE RC
PE RC
PE RC
PE KC
PE RC
PE RC
PE RC
•>£ RC
HP RC
PE RC
HP RC
PE RC
PE WP
PC WP
PE WP
PE WP
96.8
99.0
99.1
99.1
99.2
98.0
97.3
99.0
99.0
99.0
99.0
99.2
99.5
99.5
98.0
98.0
98.0
98.0
99.5
99.5
99.5
99.5
99.5
99.5
99.5
99.5
99.0
99.0
PI
PI SW
PI
PI
PI
PI
SL
SUBTOTAL
ALL UNITS —
28
— COAL — OIL — GAS —NUCLEAR—
MW UNITS MM UNITS MM UNITS MM UNITS MM
3,958 28 3,958
-------
OATc RUN
ELECTRIC UTILITY UATA
PAGE NO 42
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE « WV
UNIT F
UTILITY CO. NAMt
MONJNGAHELA PWR.
MUNONGAHELA PWA.
WEST PtNN PWR.
WEST PENN PWR.
WEST PENN PrtR.
APPALACHIAN PrfR
APPALACHIAN PrfR'
MONuNUAHELA PitA.
MONUNGAHEtA P •.>!••»*•
27
N
ST
WV
LiU
rl V
HV
WV
WV
wV
WV
WV
WV
WV
WV
WV
ViV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
WV
HV
WV
WV
MO YR
42
73
72
1 75
53
53
52
60
48
57
53
50
73
60
52
50
3 72
71
71
59
58
58
70
65
66
6 73
MH
10,879
SUE
MH
48
650
650
650
213
213
50
165
69
140
153
153
1300
450
153
153
800
bOO
800
225
225
225
800
570
570
560
TYPE HEAT PCT
1
C
C
C
C
C
C
C
C
C
C
CB
CB
C
ca
CB
CB
C
C
C
CB
CB
CB
C
C
C
Z BTU HOIS
12440 4.1
12200
12200
11486
11486
10897 4.8
10897 4.8
11041 5.7
11041 5.7
12017
12017
12017
11731
12101
12101
12101
11731
0 11137
C 11137
C D 11137
""— WWMh. W*k
UNITS MU UNITS
27 10,879
SULF-PCT PCT
MIN MAX ASH
1.6 4.4 12.3
.9 4.0
.9 4.0
4.0 4.0
.6 1.7
.6 1.7
1.0 5.4 11.0
1.0 5.4 11.0
.7 3.8 21.6
.7 3.8 21.6
.8 3.0
.8 3.0
.6 1.5
1.0 6.0
1.0 6.0
1.0 6.0
.4 3.6
.4 3.8
1.2 4.3
1.0 6.0
1.0 6.0
1.0 6.0
1.2 4.3
.7 2.0 25.5
.7 2.0 25.5
.7 2.0 25.5
MU UNITS
YR
73
69
69
73
73
73
73
74
74
73
74
74
74
72
71
70
75
75
75
70
71
71
69
TY
PE
PE
PP
v C
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
ME
ME
PE
PE
PE
ME
ME
ME
PE
PE
PE
PE
MU
MFR
AS
AS
AS
BU
BU
BU
bU
BU
BU
KC
KC
KC
KC
KC
KC
RC
RC
RC
RC
RC
RC
RC
RC
RC
RC
PCT
6FY
99.5
9Q-5
7 7 9 ^
99.5
99.5
99.5
99.5
99.5
99.5
99.5
99.5
99.5
V9.7
99.7
99.5
99.7
99.7
99.7
99.7
99.7
98.5
99.4
99.4
99.4
99.7
99.5
99.5
99.7
klllfl J
UNITS
—PARTICULATE— —S02
R TY CON
Y YR PE MFR SLT
GH
GH
GH
AP
AP
AP
AP
SR
SR
SR
AP
SH
MH
-------
OAfE RUN
ELECTRIC UTILITY DATA
PACE NO 43
LIST OF UNITS INSTALLED THROUGH 1975 BY STATE
STATE = rfY
UNIT F U E L —PARTICULATE— —S02
UN LOCATION SIZE TYPE HEAT PCT SULF-PCT PCT TY PCT R TY CON
PLANT NAME IT CITY ST MO YR Mrt 1 2 BTU MOIS MIN MAX ASH YR PE MFR EFY Y YR PE MFR StT
UTILITY CO. NAME
PACIFIC P»R & L.T
UTAH PwR.<.
JOHNSTON o.
NAUGHTON
04 &LENROCK
03 KEMMERER
HY
MY
72 330 C
71 330 CS 0
7583
.8 .8 9.3
.5 .5 4.7
Sc
PE
99.7
98.0
FS CH
EB
SR
UTAH PWR.tLT.
NAUGHTON
01 KEMMERER
HY
63 163 CS 0 9413
.5 .5 4.7 72 ME LC 99.1
PACIFIC PM8 &. LT
BRIDGE* JIM
01 ROCK SPRINGS
WY
74 500 C
74 PE SF 99.3
BE
>£>
SU3TOTAL
GRAND TOTAL
ALL UNITS
4
582 142,657
Mln
1.323
— COAL - _
UNITS MW UNITS
4 1.323
582 142,657
— GAS —
MW UNITS MM
—NUCLEAR-
UNITS MW
-------
APPENDIX B
GRAPHICAL CORRELATIONS OF CAPITAL AND
ANNUALIZED OPERATING COSTS, AS A
FUNCTION OF PLANT POWER OUTPUT FOR
ELECTROSTATIC PRECIPITATORS
B-l
-------
O
O
Q.
-------
28
26
24
22
20
18
16
to deviate above or below
I-X the curve.
o
o
S 14
Q.
.5
12
10
T
T
T
I \ I
Note: each curve repre-
sents a band of values Coal: Bituminous
that could be expected Boiler: Cyclone
Key for % sulfur
0.6%
95.0
_L
TOO 200 300 400 500 600 700 800 900 1000
POWER OUTPUT, MM.
Figure B-2. Capital cost: cold-side ESP, cyclone-fired bituminous.
B-3
-------
Coal: Subbitundnous
Boiler: Pulverized coal
Key for % sulfur
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
"•••«»-*«» 99.5
95.
TOO 200 300 400 500 600 700 800 900 1000
POWER OUTPUT, MW
Figure B-3. Capital cost: cold-side ESP, pulverized
subbituminous.
B-4
-------
24
I I
EACH CURVE REPRESENTS
A BAND OF VALUES THAT
COULD BE EXPECTED TO
DEVIATE ABOVE OR
BELOW THE CURVE.
I I
COAL: LIGNITE
BOILER: PULVERIZED COAL
KEY FOR % Na20
6.0%
100 200 300 400 500 600 700 800 900 1000
POWER OUTPUT, MW
Figure B-4. Capital cost: cold-side ESP,
pulverized lignite.
B-5
-------
30
28
26
24
22
20
I 18
_i
«c
£ 16
o
14
12
10
8
Western Coal: %
Boiler:
Na20 = 0.2
Fe2°3 = 5'°
Pulverized
coal
Note: each curve repre-
sents a band of values
that .could be expected
to deviate above or below
the curve.
100 200 300 400
500
600
700
800
POWER OUTPUT, MW
Figure B-5. Capital cost: hot-side
ESP, pulverized low-sodium western coal,
900 1000
B-6
-------
30
28
26
24
22
20
0 18
, c
16
14
12
10
8
to
o
o
Western Coal:
Boiler:
1
Na20 = 2.0
Fe2°3 = ^'^
Pulverized "
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
_L
_L
_L
_L
100 200 300 400 500 600
POWER OUTPUT, MW
700
800
Figure B-6. Capital cost: hot-side ESP,
pulverized western coal.
900 '1000
B-7
-------
5
30
28
26
24
22
20
8 18
«c
14
12
10
Eastern Coal:
r~
= 0.2
= 9.0
Boiler: Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
100 200 300 400 500 600 700
POWER OUTPUT, MW
800
900 1000
Figure B-7. Capital cost: hot-side ESP,
pulverized low-sodium eastern coal.
B-8
-------
30
28
26
24
22
20
8 18
O
16
14
12
10
Eastern Coal:
= 2.0
= 9.0
Boiler: Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
_L
_L
100 200 300 400 500 600 700
POWER OUTPUT,'MW
800
Figure B-8. Capital cost: hot-side ESP,
pulverized eastern coal.
900 1000
B-9
-------
CO
o
Western Coal:
% Na-O
Boiler:
23
Cyclone
_ r
= 0.2
= 5.0
Note: each curve repre-
sents a band of values
that coul'd be expected
to deviate above or below
the curve.
600
700
800
900 1000
POWER OUTPUT, MW
Figure B-9. Capital cost: hot-side ESP,
cyclone-fired low-sodium western coal.
B-10
-------
30
28
26
24
22
20
S 18
5 16
14
12
•10
8
100
J_
—i 1 1 1 r-
Western Coal: % Na~0 = 2.0
% Fe-O- =5.0
Boiler: Cyclone
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or t>elow
the curve.
4-
_L
200 300
400
500
600 700
800
POWER OUTPUT, MW
Figure B-10. Capital cost: hot-side ESP,
cyclone-fired western coal.
900 1000
B-ll
-------
- 18
oo
o
o
16
14
12
10
Eastern Coal:
I Na_0 =0.2
% Fe~0^ = 9.0
Boiler: Cyclone
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
100 200
300
400
500
600
700 800 900 1000
POWER OUTPUT, MW
Figure B-ll. Capital cost: hot-side ESP,
cyclone-fired low-sodium eastern coal.
B-12
-------
30 -
28
26
24
22
20
tf
8 18
<:
i—i
Q.
16
14
12
10
8
i n i
Eastern Coal:
i i
Na20 =2.0
% Fe20_ = 9.0
Boiler: Cyclone
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
_L
100 200 300 400
500
600
700
800
POWER OUTPUT, MW
Figure B-12. Capital cost: hot-side ESP
cyclone-fired eastern coal.
900 1000
B-13
-------
0.52
0.48
0.44
0.40
| 0.36
r—
1 0.32
g 0.28
o
OJ
n.
o
0.24
0.20
0.16
0.12
0.08
0.04
Coal:
Boiler:
Key for % sulfur
____ 0.6%
3.0%
1 j-
Bituminous
Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
100 200 300 400 500 600 700 800 900 1000
POWER OUTPUT. MW
Figure B-13. Operating cost: cold-side ESP,
pulverized bituminous
B-14
-------
CO
o
o
CO
0.52
0.48
0.44
0.40
0.36
0.32
0.28
0.24
0.20
0.16
0.12
0.08
T 1 1 1 T
Coal: Bituminous
Boiler: Cyclone
'••«•«•. 99 5 ~
^^ ^* «» «W ^^ ^^ -7 J * *x
99.0
Key for % sulfur
0.6%
1.2%
3.0%
97.5
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
0.04
J.
_L
J_
100
200 300
400 500 600
POWER OUTPUT, MW
700 800 900 1000
Figure B-14. Operating cost: cold-side ESP,
cyclone-fired bituminous.
B-15
-------
0.56
Subbitumxnous
Boiler: Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
400 500 600
POWER OUTPUT, MW
Figure B-15. Operating cost: cold-side ESP,
pulverized subbituminous.
1000
B-16
-------
LU
a.
o
0.60
0.56
0.52
0.48
0.44
0.40
0.36
0.32
0.28
0.24
0.20
0.16
0.12
J_
Western Coal:
Coal:
—1
= 0-2
= 5.0
Boiler: Pulverized
coal
Note: each curve repre-
sents a band of valu^^
that could be expected
to deviate above or below
the curve.
_L
J_
_L
100 200 300
400 500 600 700
POWER OUTPUT, MW
J_
800 900 1000
Figure B-16. Operating cost: hot-side ESP,
pulverized low^sodium western coal.
B-17
-------
0.48
0.44
0.40
0.36
0.32
IS)
1 0.28
A
to
S 0.24
CD
2 0.20
o.
o
0.16
0.12
0,08
0.04 -
Coal:
Boiler:
1 r
Lignite
Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
Key for % Na2O
1.2%
6.0%
0
100 200
L
300 400 500 600
POWER OUTPUT, MW
700 800
900 1000
Figure B-17.
Operating cost: cold-side ESP,
pulverized lignite.
B-18
-------
.52
.48
.44
.40
.36
.^ .32
E
oo
O
0 .28
CO
2
UJ
Q-
O
.24
.20
,16
,12
.08
.04
NOTE: EACH CURVE REPRESENTS
A BAND OF VALUES THAT
COULD BE EXPECTED TO
DEVIATE ABOVE OR
BELOW THE CURVE.
COAL:' LIGNITE
BOILER: PULVERIZED COAL
KEY FOR % Na20
,____ 1.2%
6.0%
99.9
100 200 300
400 500 600 700
POWER OUTPUT, MW
800
900 1000
Figure B-18. Operating cost: hot-side ESP,
pulverized western coal.
R-1Q
-------
0.60
0.56
0.52
0.48
0.44
0.40
CO
S 0.36
to
CD
Z
LU
Q.
O
0.32
0.28
0.24
0.20
0.16
0.12
Eastern Coal: % Na2O = 0.2
% FeoO_ = 9.0
Boiler: Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
100 200 300
400 500 600 700
POWER OUTPUT/ MW
800 900 1000
Figure B-19. Operating cost: hot-side ESP,
pulverized low-sodium eastern coal.
B-20
-------
I
o
o
(3
§
LU
0.
O
0.60
0.56
0.52
0.48
0.44
0.40
0.36
0.32
0.28
0.24
0.20
0.16
0.12
J_
i i r
Eastern Coal: S
Boiler:
%
I i
Na20 =2.0
Fe203 =9.0
Pulverized
coal
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
JL
J_
JL
J_
j_
TOO 200 300 400 500 600 700
POWER OUTPUT MW
J_
800 900 1000
Figure B-20. Operating cost: hot-side ESP,
pulverized eastern coal.
B-21
-------
CO
OO
o
0.60
0.56
0.52
0.48
0.44
0.40
0.36
§
gj ,"0.32
0.28
0.24
0.20-
0.16-
0.12
Western Coal:
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
J_
100 200 300 400 500 600 700 '800 900 1000
POWER OUTPUT, MW
Figure B-21. Operating cost: hot-side ESP,
cyclone-fired low-sodium western coal.
B-22
-------
0.60
0.56
0.52
0.48
0.44
f 0.401-
5
•—t •
5 0.36
•
I 0.32
3
i—<
i 0.28
Ul
§»
0.24
0.20
0.16
0.12
I I
Eastern Coal:
I
I Na20 =0.2
% Fe2
-------
0.60
0.56
0.52
0.48
0.44
0.40
0.36
O
o
CO
P 0.32
2
CL
O
0.28
0.24
0.20
0.16 -
T
Eastern Coal: %
^O = 2.0
% Fe203 =9.0
Boiler: Cyclone
Note: each curve repre-
sents a band of values
that coul-d be expected
to deviate above or below
the curve.
200 300
400 500 600
POWER OUTPUT, MW
Figure B-23. Operating cost: hot-side ESP,
cyclone-fired eastern coal.
700 800 900 1000
B-24
-------
0.60
0.56
0.52
0.48
0.44
£ 0.40
'i
o
o
0.36
0.32
0.28
0.24
0.20
0.16
0.12
Western Coal: % Na20 =2.0
% Fe2O- =5.0
Boiler: Cyclone
Note: each curve repre-
sents a band of values
that could be expected
to deviate above or below
the curve.
_L
JL
JL
-L
100 200 300
400 500 600
POWER OUTPUT, MW
700
800 900 1000
Figure B-24. Operating cost: hot-side ESP,
cyclone-fired western coal.
B-25
-------
APPENDIX C
PRE-OPERATING CHECKLIST FOR PRECIPITATORS
C-l
-------
APPENDIX C. PRE-OPERATING CHECKLIST
FOR PRECIPITATORS
1.) General
Before start-up of the precipitator(s) and auxiliary
equipment, a complete check and visual inspection of
the following items should be performed.
2.) Precipitator
a) Duct spacing
b) Collecting plates
0 Bowing
0 Bellying
0 Supports
0 Spacer bars
0 Corner guides
c) Gas sneakage baffles
d) Anti-swing devices
e) Hoppers
0 Dust level indicators
0 Outlet connections
0 Access doors
0 Poke holes - anvils
0 Vibrators
f) Insulator housing
0 Support bushings
0 Access doors
0 Ventilation system
0 Bushing connections
0 Bushing heaters
Check Initial Date Recheck Remarks
C-2
-------
Check
Initial
Data
Recheck
Remarks
g) Flues
0 Nozzle connections
0 Expansion joints
0 Louver dampers
0 Guillotine dampers
0 Perf. distribution
plates
h) Line voltage
0 460/480 volts-60 Hz
0 575 volts - 60 Hz
0 120 volts
0 Line matching transformer
i) Discharge electrode wires
0 Upper steadying frame
0 Lower steadying frame
0 Hanger pipes
0 Lifting rods
0 C.I. weights -
15 25 35
j) High-tension guard
0 Installation
0 Vent ports open
0 Ground connections
k) Drag bottom conveyor
1) Wet bottom agitators
m) Heat jacket system
0 Recirculating fan
0 Electric heater - kW
0 Steam heater coils
0 Temperature transmitters
0 Pneumatic recorders
0 Steam control valve
0 Starters - pushbuttons
0 Thermostats
n) Roof enclosure
0 Ventilation
0 Air conditioning
0 Monorail system
0 Roof exhausters
0 Louvers
0 Heaters
C-3
-------
o) Gaskets for high
temperature
3.) Auxiliary Equipment
a) Transformer-rectifier
units
b)
d)
o
o
o.
o o
o o
o o
o o
o o
o o
o o
o o
p
o
o
o
o
Surge arrester gap
Transformer liquid level
Ground connections
Precipitator
Transformer
Rectifier
H.T. bus duct
Conduits
FW/HW switch box
Alarm connections
Contact making
thermometer
Ground switch
operation
High-voltage connections
Telephone jacks
Sound power jacks
Resistor board
Space heaters
Rectifier control units
0 Controls grounded
0 Connections to
equipment
0 Space heaters
0 Internal light and
switch
0 Alarm connections
0 Space heaters
c) Rapper control unit
o
o
o
Connections
Lights
Space heaters
Vibrator control unit
0 Connections
0 Lights
0 Space heaters
Check
Initial
Data
Recheck
Remarks
— —
.. - — . — —
C-4
-------
e)
f)
g)
h)
i)
j)
k)
1)
m)
n)
o)
P)
q)
F.D. Ventilation
controls
0 Motor
0 Starters
0 Pushbutton stations
0 Alarm connections
0 Filters
Electric heater controls
0 Hoppers
0 Insulator housing/
compartment
0 Roof enclosure
0 Control house
Control house
0 Heaters
0 Ventilation
0 Motor control centers
0 Distribution
panelboards
0 Lighting panelboards
0 Starters
Screw conveyors
Rotary feeder valves
Zero speed detectors
Speed reducers
Trough type hoppers
Inner doors - drag bottom
level
Air vibrators
Air vibrator controls
Water spray piping
Pillow block assembly
Check
Initial
Data
Recheck
Remarks
C-5
-------
r) Automatic back draft
pampers
s) Filter boxes - filters
t) Butterfly dampers
Check
Initial
Date
Recheck
Remarks
C-6
-------
APPENDIX D
CHECKLIST FOR OBTAINING DESIGN AND OPERATING
DATA ON PARTICULATE SCRUBBERS
D-l
-------
APPENDIX D
CHECKLIST FOR OBTAINING DESIGN AND OPERATING DATA
ON PARTICULATE SCRUBBERS
Design and Operating Parameters:
Start-up date
Application
Vendor
Design type
Firing method
No. of equipped boilers
No. of scrubber modules
Installed scrubber capacity, MW
Reheat?
Capital cost, $/kW
Coal type
Sulfur in coal, pet.
Ash in coal, pet.
CaO in ash, pet.
Gas flow, acfm
Temperature, °F
Gas flow/module
Scrubber cross section
Cross section (type)
Length of scrubber
Gas velocity, fpm
Gas retention time
Particle size distribution
Inlet dust loading, gr/scfd
Inlet SO2, ppm
L/G, gal/1000 acf
D-2
-------
Method of water injection (type)
Nozzle type
Flow rate per nozzle, gal/hr
Pressure drop across nozzle, in. H20
Number of nozzles
Average droplet size
Average droplet speed
Open or closed loop
Total pressure drop, in.
Type of scrubber
Diameter of collector, in.
Bed porosity
Expanded bed height, ft
Linear size of membrane
Overall collection efficiency
Fractional collection efficiency
Water requirement, acre-ft/yr
Acre-ft/MW yr
Elec. power requirement
Elec. power, pet. of generating capacity
Manpower, total operators
Availability, pet.
D-3
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-77-129
2.
3. RECIPIENT'S ACCESSION'NO.
4. TITLE AND SUBTITLE
Operation and Maintenance of Particulate Control
Devices on Coal-Fired Utility Boilers
5. REPORT DATE
July 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHO«(S) ~ —
Michael F. Szabo and Richard W. Gerstle
8. PERFORMING ORGANIZATION REPORT NO.
PN 3216
9. PERFORMING ORGANIZATION NAME AND ADDRESS
PEDCo Environmental /.-•=inc.
11499 Chester Road
Cincinnati, Ohio 45246
10. PROGRAM ELEMENT NO.
1AB012: ROAP 21AD1.-087
11. CONTRACT/GRANT NO.
68-02-2105
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 6/75-6/77
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES
IERL-RTP project officer for this report is Dennis C. Drehmel,
Mail Drop 61, 919/541-2925.
16. ABSTRACT
The report discusses the control of fine particulate from coal-fired utility
boilers, using electrostatic precipitators (ESPs), wet scrubbers, and fabric filters.
It provides guidelines to utility personnel, responsible for selecting fine particulate
control equipment, on significant design and cost data correlations based on current
design practice for ESPs and actual operating and cost data for wet scrubbers and
fabric filters. It gives fractional efficiency prediction models for ESPs and wet
scrubbers, allowing comparison of capital and operating costs under different coal/
boiler application conditions and different levels of fractional efficiency.
7.
K«Y WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Dust
Coal
Utilities
Boilers
Electrostatic Precipitators
Scrubbers
Dust Filters
Fabrics
Mathematical Models
Air Pollution Control
Stationary Sources
Particulate
Fractional Efficiency
13B
11G
21D
13A
07A
13K
HE
12A
3. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report}
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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