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United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-79-199b
August 1979 .. .
Survey of Flue Gas
Desulfurization Systems:
Lawrence Energy Center,
Kansas Power and Light Co.
Interagency
Energy/Environment
R&D Program Report
-ji;. --..=.,»-~f^--
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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 nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
ilk- » *
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental 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 Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-79-199b
August 1979
Survey of Flue Gas
Desulfurization Systems:
Lawrence Energy Center,
Kansas Power and Light Co
by
Bernard A. Lasekf, Jr.
PEDCo Environmental, Inc.
11499 Chester Raad
Cincinnati, Ohio 45246
Contract No. 68-02 2603
Task No. 24
Program Element No. EHE624
EPA Project Officer: Neman Kaplan
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and D jveloprnent
Washington, DC 2O460. pin,,-,- - " t/y
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TABLE OF CONTENTS
Page
List of Figures iii
List of Tables iv
Acknowledgment v^
. Summary vl:L
1. Introduction 1
2. Facility Description 2
3. Flue Gas Desulfurization System 6
Background Information 6
Process Description 22
Process Design 31
Process Chemistry: Principal Reactions 42
Process Control 46
4. FGD System Performance 50
Background Information 5^
Operating History and Performance 51
Problems and Solutions 51
System Performances Dependability, Removal
Efficiencies, and Chemical Characterization 55
Future Operations 62
Appendix A. Plant Survey Form A"1
Appendix B. Plant Survey Form B"1
Appendix C. Plant Photographs C"1
11
r.
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No.
LIST OF FIGURES
gage
1 View of the Lawrence 5 Combustion Engineering 3
Steam Generator
2 Scrubber Train Schematic for Lawrence Unit 5 9
3 Simplified Process Flow Diagram of the Lawrence 10
Limestone-injection and Tail-end Scrubbing System
4 Lawrence 4 Flow Diagram: December 1968 15
5 Lawrence 4 Flow Diagrams October 1969 16
6 Lawrence 4 Flow Diagram: October 1970 18
7 Lawrence 4 Flow Diagram: October 1972 20
8 Lawrence 4 Limestone preparation and Handling System 24
9 Diagram of the Proprietary Mist Eliminator Design 27
Used in the Lawrence Scrubbing System
10 Simplified Process Flow Diagram of One of the Two 30
Lawrence 4 Scrubbing Modules
11 Simplified Process Flow Diagram of One of the Two 32
Lawrence 5 Scrubbing Modules
12 Diagram of Slurry Hold Tank Strainer and Wash 43
Mechanism
13 Arrangement of Variable-throat Rod-deck Venturi
Scrubber
54
14 Lawrence 4 Scrubbing System Performance Summary - _ 60
Particulate Emission as a Function of Rod-deck Venturi
Scrubber Differential Pressure: October 1977
15 Summary of Lawrence 4 Scrubbing System Performance - 61
Particulate Emission Versus Opacity: October 1977
16 Schematic of Jeffrey Steam Generator and Emission 66
Control Equipment
iii
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LIST OF TABLES
No. ; Page
1 Data Summary; Lawrence 4 and 5 ix
2 Design, Operation,, and Emission Data; Lawrence 4 5
and 5
3 Summary of Data 2 Scrubber Modules 11
4 Summary of Data: Mist Eliminators 12
5 Summary of Data; Reheaters 12
6 Summary of Data: Recycle Tanks 13
7 Summary of Data; Pressure Drop 13
8 Specifications and Consumption Rates of Performance 33
Coal
9 Inlet and Outlet Gas Conditions a id Design Removal 34
Efficiencies
10 Rod-deck Scrubber Design Parameters and Operating 36
Conditions
11 Spray Tower Absorber Design Parameters and 37
Operating Conditions
12 Mist Eliminator Design Parameters and Operating 38
Conditions
13 Reheater Design Parameters and Operating Conditions 39
14 Gas-side Pressure Drop Data 40
15 Waste Disposal. Design Parameters and Operating 41
Condition!.
16 Sum.uary of Lawrence 4 Scrubbina System Performance— 57
Analysis of Solids; October 1.977
(continued)
iv
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LIST OF TABLES (continued)
™~ Page
No. —2—
17 Summary of Lawrence 4 Scrubbing System Performance— 57
Gypsum Crystallization Data: October 1977
18 Summary of Overall Performance of Lawrence 4 58
Scrubbing: October 1977
19 Lawrence 4 Scrubbing System Performance Summary: 59
October 1977
20 Jeffrey Average Ultimate and Ash Coal Analysis 64
21 Summary of Jeffrey 1 and 2 Emission Control Systems 67
22 Summary of Jeffrey 1 and 2 Gas Plow Rates 68
23 Summary of Jeffrey 1 and 2 Draft Losses 68
24 Summary of Jeffrey 1 and 2 Liquid Flow Rates 69
v
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ACKNOWLEDGMENT
This report was prepared under the direction of Mr. Timothy
Devitt. The principal author was Mr. Bernard Laseke.
Mr. Norman Kaplan, EPA Project Officer, had primary respon-
sibility within EPA for this project report. Information on
plant design and operation was provided by the following members
of the Kansas Power and Light Companys Mr. Kelley Green, Elec-
tric Production Manager, and Ron Teeter, Plant Superintendent,
Lawrence Energy Center. Mr. A. J. Snider, Manager, Environmental
Control, Combustion Engineering, Inc., also provided information
on plant design and operation.
VI
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SUMMARY
The Lawrence Energy Center, a power generating station with
a capacity of 625 MW (gross)> is owned and operated by the Kansas
Power and Light Company (KP&L) in Lawrence, Douglas County,
Kansas. The station consists of five power generating units, the
first of which was built in 1939. Lawrence 2 and 3 are oil/gas-
fired peaking units rated at 30 and 60 MW. Lawrence 4 and B are
multiple-fuel-fired units that now fire coal exclusively, and are
rated at 125 and 400 MW.
Lawrence 4 and 5 are equipped with, tail-end wet limestone
scrubbing systems to meet air emission regulations of the Depart-
ment of Health and Environment of the State of Kansas and the
U.S. Environmental Protection Agency. Control of particulate and
sulfur dioxide is accomplished by operational scrubbing systems
consisting of two parallel two-stage scrubber modules, each of
which includes a rectangular, variable-throat rod-deck venturi
scrubber arranged in series with a spray tower absorber. Each
system is also equipped with slurry-hold tanks, mist eliminators,
and in-line reheaters, as well as isolation and bypass dampers
that permit the modules to be bypassed during periods when oil
or natural gas may be burned in the boilers. The two systems
share a common limestone storage and preparation facility and
waste-disposal facility.
The scrubbing systems, which were designed and supplied by
Combustion Engineering, represent a second-generation design
replacement of the limestone furnace-injection and tail-end
scrubbing systems originally installed on these boilers in 1968
and 1971.
Vll
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The original limestone furnace-injection and tail-end scrub-
bing system retrofitted on Lawrence 4 was started up in November
1968 and operated until raid-September 197i, when it was shut down
to perform a scheduled turbine overhaul. During the course of
this overhaul (2-1/2 months), the new scrubber modules were
completed. The new system went into service in early January
1977. During the November 1968 to September 1976 period, the
original injection system operated on coal-fired flue gas approx-
imately 27,000 hours. To date, the new scrubbing system has
accumulated approximately 10,000 hours of service time.
The original limestone furnace-injection and tail-end scrub-
bing system, installed as new equipment on Lawrence 5, started up
in November 1971 and operated until March 20, 1978, when it was
shut down to complete the tie-in of the new scrubbing system to
the flue gas path. The new scrubber modules were erected directly
behind the existing system? which remained in service during the
construction period. Because the new system, which went into
service on April 14, 1978, was designed to use the existing
reaction tank, spray pumps, induced-draft fans, and stack, a 4-
week outage was required to complete installation. The original
injection system accumulated approximately 23,000 hours of
service time on coal-fired flue gas.
Kansas Power and Light is now in the process of developing
the Jeffrey Energy Center, a coal-fired power generating station
with a 2880-MW (gross) capacity. This station is composed of
four coal-fired units, having a capacity of 720 MW (gross).
Scheduled for operation in October 1978, June 1980, 1982, and
1984, these units will fire low-sulfur Wyoming coal. The steam
generators and emission control systems for Jeffrey 1 and 2 are
designed and supplied by Combustion Engineering. The emission
control systems include an overfire air system at the tangential-
fired pulverise,,. ; arners for nitrogen oxide abatement, electro-
static precipitators for particulate control, and limestone
VI11
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slurry spray towers for sulfur dioxide control. Because the
Jeffrey scrubbing systems are similar in design to the Lawrence
systems, the experience gained at Lawrence will facilitate the
design and operation of the Jeffrey systems.
Table 1 summarizes data on the Lawrence facility and scrub-
bing systems.
TABLE 1. DATA SUMMARY: LAWRENCE 4 AND 5
Units
4 and 5
Gross rating, MW
Lawrence 4
Lawrence 5
Net rating, MW
Lawrence 4
Lawrence 5
Fuel
Average fuel characteristics
Heating value, kJ/kg (Btu/lb)
Ash, percent
Moisture, percent
Sulfur, percent
FGD process
FGD system supplier
Status
Startup dates
Lawrence 4
Lawrence 5
Design removal efficiency
Particulate, percent
Sulfur dioxide, percent
Lawrence 4
Lawrence 5
Water loop
Sludge disposal
125
420
115
400
Coal
23,260 (10,000)
9.R
11.8
0.55
Limestone
Combustion Engineering
Operational
January 1977
April 1978
98.9
73
52
Closed
Unstabilized sludge disposed
in an onsite pond
xx
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SECTION 1
INTRODUCTION
The Industrial Environmental Research Laboratory (IERL) of
the U.S. Environmental Protection Agency (EPA) has initiated a
study to evaluate the performance characteristics and reliability
of flue gas desulfurization (FGD) systems operating on coal-fired
utility boilers in the United States.
This report, one of a series on such systems, covers the
Lawrence Energy Center of the Kansas Power and Light Company
(KP&L). It includes pertinent process design and operating data,
a description of major startup and operational problems and
solutions, and atmospheric-emission data.
This report is based on information obtained during and
after a plant inspection that KP&L conducted for PEDCo Environ-
mental personnel on June 8, 1977. The information presented in
this report is current as of October L978.
Section 2 provides data on facility design and operation;
Section 3 provides background information, as well as a detailed
description and design features of the air quality control
systems; Section 4 describes and analyzes the operation and
performance of the air quality control systems. Appendices A, B,
and C contain details of plant and system operation and photos of
the installation.
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SECTION 2
FACILITY DESCRIPTION
The Lawrence Energy Center, a power generating station with
a capacity of 625 MW (gross), is owned and'operated by KP&L.
Located in Douglas County, the station is situated in a lightly-
industrialized area on the outskirts of Lawrence, a town of about
47,000 people, near the Kansas River.
The station consists of five power generating units. The
first, Lawrence 1, was built in 1939. This 10-MW turbine is
powered by extraction steam from Lawrence 5. Lawrence 2 and 3,
oil/gas-fired units rated at 30 and 60 MW, were originally placed
in service in 1950 and 1956, and operate as peaking units.
Lawrence 4, rated at 125 MW, and Lawrence 5, rated at 400 MW, are
multiple-fuel-fired units that now fire pulverized coal exclu-
sively. In service since 1959 and 1971, respectively, they
currently operate as cyclic-load units.
The steam generators for Lawrence 4 and 5 are balanced-
draft, tangential-fired, multiple-fuel-burning units supplied by
Combustion Engineering. Lawrence 5 produces 1272 Mg (2,805,000
lb) per hour of superheat steam at 540°C (1005°F) and 18.1 MPa
(2620 psi) and reheat steam at 540°C (1005°F). Figure 1 presents
a view of the Lawrence 5 steam generator.
'Although they were designed to burn pulverized coal, oil,
and/or gas in any combination, both units are now fueled exclu-
sively by a low-sulfur subbituminous grade of coal, which
originates from mines located in Medicine Bow in the southeast
section of Wyoming. This coal contains on the average 0.5
percent sulfur, IU percent ash, and 12 percent moisture, and has
a heating value of 23,260 kj/kg (10,000 Btu/lb). At full load,
Lawrence 4 and Lawrence 5 consume approximately 45 Mg (50 tons)
and 145 Mg (150 tons) of coal per hour, respectively.
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Figure 1. View of the Lawrence 5
Combustion Engineering steam generator,
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To meet air omission regulations of the oapcutwau* or Hart S t U
and Environment of th© State of Kansas and the u.vS, NVA, eaoh
unit is equipped with A ••t<*il-^«U w*H ii«vs*at)v»««» puJvvtWU^vj «y
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TABLE 2. DESIGN, OPERATION, AND EMISSION DATA:
LAWRENCE 4 AND 5
Description
Generating capacity, MW
Gross
Net with scrubbing
Maximum coal consumption,
Mg/h (tons/h)
Maximum heat input, GJ/h
(106 Btu/h)
Maximum flue gas rate, m /s
(103 acfm)
Flue gas temperature, "C (°F)
Unit heat rate, kj/net kWh
(Btu/net kWh)
Unit capacity factor,
percent (1977)
Emission control
Particulate
Sulfur dioxide
Particulate emission rate
Allowable, ng/J
(lb/106 Btu)
Actual, ng/J
(lb/106 Btu)
Sulfur dioxide emission rate
Allowable, ng/J
'(lb/106 Btu)
Actual, ng/J
(lb/106 Btu)
Lawrence 4
125°
115a
1,055 (1,000)
190 (403,000)
138 (280)
10,900 (10,300)
55-60
Rod-deck
venturi
scrubbers
Spray tower
absorbers
43 (0.1)
34 (0.08)
129 (0.3)
6.5-13 (0.015-0.08)
Lawrence 5
400
375
145 (150)
j
3,376 (3,200)
600 (1,271,000)
149 (300)
10,900 (10,300)
55-60
Rod-deck
venturi
scrubbers
Spray tower
absorbers
43 (0.1)
215 (0.5)
Gross output of Lawrence 4 is as high as 143 MW when natural
gas is burned in the boiler. This value decreases to 125 MW
when coal and natural gas are burned in the boiler.
Retrofitting the boiler with the limestone-injection scrubbing
system in 1968 reduced the unit's net output to 115 MW.
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SECTION 3
FLUE GAS DESULFURIZATION SYSTEM
BACKGROUND INFORMATION
Approach
In 1967 KP&L decided to expand the generating capacity of
Lawrence Energy Center by adding a 400-MW unit. At that time
KP&L was still classified as a'gas-fired utility, even though 65
percent of its steam generators were equipped to fire pulverized
coal. Because of the increasing potential interruptions in gas
supply, KP&L designed Lawrence 5 to burn primarily coal, supple-
mented by natural gas and fuel oil.
When planning this addition, KP&L assumed that some ambient
and/or emission regulations for particulate and sulfur dioxide
would be in effect by the commercial startup date of Lawrence 5
(November 1971). This assumption, plus the availability of high-
sulfur Kansas coal, prompted the decision to install, as original
equipment, facilities to remove particulate and sulfur dioxide
from the flue gas of Lawrence 5.
The emission-control strategy selected for Lawrence 5 was a
limestone wet scrubbing system. This furnace-injection, tail-end
system was developed by Combustion Engineering. This steam
generator supplier has been committed since 1964 to an intensive
research and development program based on work done earlier in
the field of oil and coal corrosion and stack gas emission
control.
Lacking full-scale scrubbing experience on utility coal-
fired steam ger .. .ors, KP&L decided to retrofit a similar but
smaller sy.tera on Lawrence 4, an existing 125-MW unit, to obtain
valuable design and operating experience prior to startup of the
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larger unit. Construction on this scrubber system began in March
1968, and initial startup occurred in November 1968. Construc-
tion of the Lawrence 5 boiler and scrubbing system also commenced
in March 1968 and proceeded simultaneously with the retrofit work
on Lawrence 4. Initial operation of Lawrence 5, including the
emission control system, occurred in March 1971. Shakedown and
debugging of the equipment was completed, and commercial operations
began in November 1971.
Design
The original scrubbing systems installed on Lawrence 4 and
5 were identical in basic design and operation. Each system
included facilities for pulverizing limestone and then injecting
it into the boiler furnace chamber for calcination. The flue gas
transported the calcined limestone and fly ash to the scrubber
modules for particulate and sulfur dioxide scrubbing. The
cleaned gases then passed through a set of mist eliminators,
reheaters, and induced-draft fans before being discharged through
the stacks to the atmosphere.
The Lawrence 4 scrubbing system consisted of two scrubber
modules. The Lawrence 5 scrubbing system was originally equipped
with six, and two more were added soon after startup. All the
modules were identical in size; each was designed to handle
approximately 70 m3/s (150,000 scfm) of flue gas. Each module
had a single marble bed of 1.9-cm (0.75-in.) diameter Pyrex glass
marbles. The beds were approximately 9 cm (3.5 in.) thick and
included overflow pots for drainage of spent slurry into the
receiving recirculation tanks.
Each module was also equipped with mist eliminators and
reheaters. Two stages of horizontal, chevron-type mist eliminators
were situated approximately 1.5m (4.5 ft) above the marble bed.
Four rows of carbon steel finned-tube reheat bundles were
situated approximately 6.5m (20 ft) above the second mist
eliminator stage. The mist eliminators were equipped with
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automatic retractable wash lances that sprayed pond return water
under high pressure [0.7 MPa (100 psig)] 1 cycle each day. Thp
reheaters were also equipped with a self-el.aanimi system in whioh
high-pressure [0.65 to 0.80 MPa (80 to 100 psig}] compressed air
was blown from lances for 3 minutes six times daily.
Each Lawrence 4 module was connected through an induced-
draft fan to a separate 36-m (120-ft) carbon steel stack. The
Lawrence 5 unit consists of eight modules discharging to two I.D.
fans with separate stack connections to a common 114-m (375 ft)
stack. Originally, all the modules were equipped with bypass
ducts and hydraulic seal dampers, but eKtensive corrosion and
plugging necessitated their removal from both modules of Lawrence
4. Figure 2 provides a simplified schematic of the Lawrence 5
scrubbing system arrangement.
Spent scrubbing slurry from each system was collected in a
separate, external recirculation tank, where a 35-minute reten-
tion time permitted completion of chemical reactions and where
pond return water and discharge of spent slurry were added.
The waste streams from both systems were discharged to
onsite, unlined settling ponds for ultimate disposal of waste
solids. The scrubbing wastes were collected in three ponds with
areas of 16,000 m2 (4 acres), 65,000 m2 (16 acres), and 113,000
m2 (28 acres). Clarified supernatant from these ponds was
returned to the systems for further use after selective staging.
Figure 3 is a simplified process flow diagram of the lime-
stone furnace-injection and tail-end scrubbing system installed
and operated at Lawrence. Design parameters and operating
conditions for the Lawrence scrubbing systems are summarized in
Tables 3, 4, 5, 6, and 7.
Performance
Problems and So1r^ions--
As indicated above, the Lawrence 4 scrubbing system was
placed in service in March 1968, approximately 3 years before
that of Lawrence 5. Although the configuration of these original
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WATER DAMPER
BOILER
DAMPER
^
O
AIR
HEATER
O
FAN
SCRUBBERS
STACK
Figure 2. Scrubber train schematic for Lawrence Unit 5.
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FURNACE
FEEDER
PULVERIZER
STACK
I.D. FAN
STACK GAS
REHEATER
RECYCLE
WATER
F.D. FAN
STACK 6AS
SCRUiSER
Figure 3. Simplified process flow diagram of the Lawrence limestone-injection
and tail-end scrubbing system.
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TABLE 3. SUMMARY QF DATA: SCRUBBER MODULES
Category
Lawrence 4
Lawrence 5
Number of modules
Type
Capacity, m /s (scfm)
Liquid-to-gas ratio (L/G),
liters/m3 (gal/103 acf)
Superficial gas velocity,
m/s (ft/s)
Equipment internals
Number of beds
Bed packing thickness, cm (in.)
Marble sphere diameter, cm (in.)
Materials of construction
Shell
Internal supports
Drain pots
2 8
Marble bed
70 (150,000)
2.9 (22)
2 (6.5)
9 (3.5)
1.9 (0.75)
Flake-glass-lined carbon steel
316L SS
316L SS
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TABLE 4. SUMMARY OF DATA: MIST ELIMINATORS
Type
Configuration (relative to gas flow)
Shape
lumber of stages
Number of passes
Distance between stages, m" (ft)
Pressure drop, kPa (in. H20)
Materials of construction
Chevron
Horizontal
V-shape, sharp angle,
2
2
0.3 (1.0)
0.25 (1.0)
FRP
90-deg
bend
TABLE 5. SUMMARY OF DATAj REHEATERS
Type
Heating medium
Heating medium source
Materials of construction
Heat input, GJ/h (106 Btu/h)
Lawrence 4
Lawrence 5
AT, °C (°F)
Indirect, in-line
Hot water
Deaerator
Carbon steel
21.1 (20)
84.4 (80)
17 (30)
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TABLE 6. SUMMARY OF DATA: RECYCLE TANKS
Item
Total number of tanks
Retention time,a minutes
PH
Solids concentration, %
Lawrence 4
1
40
9.5-10
8.5-9.5
Lawrence 5
1
30
9.5-10
8.5-9.5
At full-load conditions .
TABLE 7. SUMMARY OF DATA: PRESSURE DROP
Component
Scrubber module
Mist eliminator and reheater
Duct work
Total
Pressure drop, kPa (in.
H20)
2.0 (8.0)
0.25 (1.0)
0.25 (1.0)
2.5 (10.0)
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systems was fairly simple, many operating problems and design
inadequacies were encountered. Since the purpose of installing
the Lawrence 4 scrubbing system was to gai i design and operating
experience, all design modifications and other corrective action
were first implemented on this system. Successful results were
then utilized on Lawrence 5.*
Nearly all of the problems that were encountered during and
following startup were due to improper control of process
chemistry. In the injection process, it was difficult to achieve
satisfactory control of the limestone calcination as well as the
amount of lime/limestone carried in the flue gas to the tail-end
scrubbers. 'This problem was complicated further when the boiler
operated as a cyclic-load unit and fired a variable combination
of coal, natural gas, and oil.
Figure 4 illustrates the configuration of each of the
Lawrence 4 modules when the system started operating in 1968.
This design presented many operating problems, including (1)
scale buildup and solids deposition on the hot gas inlet duct;
(2) erosion of the scrubber walls; (3) corrosion of scrubber
internals; (4) plugging and scaling of drain lines, tanks, pumps,
marble bed, mist eliminator, and reheater; (5) scale buildup on
induced-draft fan rotors, resulting in fan imbalance and vibration;
and (6) dead burning of limestone in the furnace and the dropout
of the lime with the ash in the bottom of the scrubbers.
After the first few months of operation, the scrubbers were
modified as follows: (see Figure 5).
1. Soot blowers were added in the gas-inlet duct and under
the reheater bundle to minimize solids deposition
problems.
Lawrence 5 experienced one major problem that was not encountered
with Lawrence severe gas distribution problems to and through
the marble-beu scrubber modules. This complicated scrubbing
operations on Lawrence 5 and, as a result, Lawrence 4 achieved
a higher level of operating efficiency.
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TO STACK
00
oo
WATER
SEAL
FROM AIR
HEATER
I.D. FAN
lj-1 ^vA/VWVWWW
HJ NAAAAAAAAA/W
HOT H20 REHEAT
MIST ELIMINATOR
MARBLE BED
CLARIFIED FROM POND
DRAIN TANK
SOLID DISPOSAL POND
Figure 4. Lawrence 4 flow diagram: December 1968.
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TO STACK
H
O-
FPOM AIR
HEATER
-Ufr -&K. -SMS,
D-l
SOOT BLOWER AIR
:HOT H20 REHEAT
MIST ELIMINATOR
OVERHEAD SPRAY
MARBLE BED BED OVERFLOW
OVERFLOW
CLARIFIED
FROM POND
TO SOLID
DISPOSAL
•-POND
RECYCLE TANK
DRAIN TANK
Figure 5. Lawrence 4 flow diagram: October 1969.
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2. The freeboard distance of -he mist eliminators was
increased to reduce solids carryover from the spray
zone.
3. Overflow liquor from the pots was directed to the pond.
I
4. A larger recycle tank and pump were installed to
collect and recirculate th<3 spent slurry back to the
marble bed.
5. A new type of spray nozzle was installed.
6. The bottom section of the scrubber tanks was lined with
gunite.
7. Hydraulic variable-speed drives were installed on all
the fans.
Most of the problems were reduced but not eliminated by
these modifications. For further reduction of corrosion,
erosion, scaling, and solids deposition problems, additional
modifications were made during the summer of 1970. The resulting
scrubber configuration is illustrated in Figure 6. These major
revisions included:
1. The interiors of the module-s were sandblasted and
coated with flake-glass lining.
2. All internal steel pipes were replaced with plastic and
fiberglass piping.
3. The stainless steel mist eliminators were replaced with
fiberglass components.
4. A ladder vane was added uncer the marble beds to
improve gas flow distribution.
5. The pot overflow drain piping was modified to permit
liquor return to the recycle tank.
6. The original copper fin tubes on the reheater coils
were replaced with a carbon steel fin tube coil. Be-
cause of the close spacing of the fins on the copper
tubes, the reheaters plugged easily and the fins were
flattened by the soot-blower jets.
17
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TO STACK
00
FROM AIR
HEATER
•SOOT BLOWER AIR
HOT H20 REHEAT
MIST ELIMINATOR
OVERHEAD SPRAY
MARBLE BED BED QyERFLOW
OVERFLOW
•CLARIFIED
FROM POND
TO SOLID
DISPOSAL
RECYCLE TANK
DRAIN TANK
Figure 6. Lawrence 4 flow diagram: October 1970.
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Solids deposition in the mist eliminators continued to 'be a !
serious problem, necessitating manual washing every other night
to maintain the required unit output.
In the summer of 1972, the modules were modified to operate
using a high-solid slurry-crystallization process to control
sulfate saturation and subsequent scale development. These
latest major modifications, shown in Figure 7, included the
enlargement of the liquor-recirculation tank as well as the
replacement of piping, nozzles, pumps, and agitators. The mist
eliminators were replaced with a new two-bank fiberglass unit
fitted with high-pressure wash water lances.
Even though this last series of major modifications resulted
in a dramatic improvement in overall performance, some chemical
and mechanical problems were still encountered, including isolated
corrosion, expansion-joint failure, solids deposition in the mist
eliminators, erosion and premature failure of slurry pumps,
and valve failures. Load demand at this station allowed both
units to be reduced to half-load each night so necessary and
preventive maintenance to combat these latter problems could be
accomplished without forced outages. Maintenance requirements
declined to two 8-h shifts weekly of manual cleaning per module.
In 1974 KP&L completed negotiations for a low-sulfur coal
supply from southeast Wyoming (Medicine Bow), and the high-sulfur
Kansas coal was completely phased out by late spring of 1975.
Subsequent operation of the scrubbing systems was more efficient
and economical because.of the reduced sulfur removal requirements
and the alkaline components of the fly ash. This latter factor
substantially reduced the amount of limestone required for
scrubbing since the alkaline species were already present in the
slurry from fly ash collected in the modules. As a result,
normal maintenance requirements were halved to two 4-h shifts of
manual cleaning per module.
19
-------
TO STACK
to
o
FROM AiR
HEATER
WATER
SEAL
• SOOT BLOWER AIR
#HATER WASH LANCE
HOT H20 REHEAT
CLARIFIED FROM POND
TO SOLID
DISPOSAL
RECYCLE TANK
(ENLARGED)
DRAIN TANK
Figure 1. Lawrence 4 flow diagram: October 1972.
-------
Removal Efficiency—
Both Lawrence scrubbing systems were designed to remove 99.3
percent of the inlet particulate and 65 percent of the inlet
sulfur dioxide when high-sulfur Kansas coal was combusted in the
boilers. Actual removal values indicated that these goals were
attained or exceeded. Sulfur dioxide removal efficiencies as
high as 85 percent were achieved over short periods, but only at
the expense of an accelerated rate of scale formation in the
modules, which ultimately required shutdown for cleaning and
reduced system availability.
Future Development
j
In 1976, having achieved success with scrubbing operations
at Lawrence, KP&L decided, to replace both systems with a second-
generation scrubbing design developed by Combustion Engineering.
There were several reasons for this decision:
1. During modifications and revisions in the scrubber
modules, Lawrence operated at deleterious corrosion
levels, which caused widespread deterioration of the
modules and ancillary equipment and necessitated either
the installation of new systems or the implementation
of an alternative control strategy (low-sulfur coal
combustion and electrostatic precipitators).
2. Lawrence 4 redesign was committed at approximately the
same time that the decision was made concerning the
Jeffrey Energy Center's emission control strategy. The
company decided to incorporate the use of wet particu-
late scrubbers rather than an electrostatic precipitatdr,
primarily because resistivity of the Medicine Bow
coal fly ash is very high and would require large ESP's
for attainment of 99 percent removal. This would have
necessitated relocation of other plant equipment and,
thus, was deemed impractical.
3. Lawrence 5 redesign was committed soon afterwards.
KP&L elected to employ basically the same strategy as
that developed for Lawrence 4. Many of the components
of Lawrence 5, unlike Lawrence 4, had not been destroyed
during initial phases of operation; the fact that the
air quality control system's original reaction tank,
21
-------
spray-pump system, induced-draft fans, and stack could
all be employed in the redesign gave this plan a
decided economic, spatial, and temporal advantage over
alternative strategies.
4. With the exception of the method of particulate collec-
tion, the emission control strategies developed for
Lawrence and Jeffrey Energy Centers are basically the
same. The installation of these systems at Lawrence
would provide valuable design and operating experience
for future, larger-scale applications at Jeffrey. This
would offer the added benefit that any potentially
costly modifications could be made prior to startup.
PROCESS DESCRIPTION
The limestone scrubbing systems now in service on Lawrence 4
and 5 are second-generation design units supplied and installed
by Combustion Engineering. Basically, both systems encompass the
same general equipment layout, consisting of a common limestone
storage and preparation facility, two rod-deck venturi scrubbers
and spray tower absorber modules, and a common waste disposal
facility.
The process description provided in the paragraphs that
follow particularly address the Lawrence 4 scrubbing system.
Although the Lawrence 5 scrubbing system is similar in design and
operation, a number of major features that differ are noted and
described at the end of this subsection.
The air quality control system at Lawrence 4 can be described
in terms of three basic operations: (1) limestone handling and
preparation, (2) gas treatment, and (3) waste solids disposal and
pond water return.
Reagent Handling and Preparation
Limestone for the Lawience scrubbing systems is trucked from
quarries owned and operated by the N.R. Hamm Company, approxi-
mately 3 km (2 »!'.!• north of the plant, and stored in an area
situated directly behind the milling facility. It is received as
-------
Removal Efficiency—
Both Lawrence scrubbing systems were designed to remove 99.3
percent of the inlet particulate and 65 percent of the inlet
sulfur dioxide when high-sulfur Kansas coal was combusted in the
boilers. Actual removal values indicated that these goals were
attained or exceeded. Sulfur dioxide; removal efficiencies as
high as 85 percent were achieved over short periods,, but only at
the expense of an accelerated rate of scale formation in the
modules, which ultimately required shutdown for cleaning and
reduced system availability,
Future Development
^
In 1976, having achieved success; with scrubbing operations
at Lawrence, KP&L decided to replace both systems with a second-
generation scrubbing design developed by Combustion Engineering.
There were several reasons for this decisions
1. During modifications and revisions in the scrubber
modules, Lawrence operated at deleterious corrosion
levels, which caused widespread deterioration of the
modules and ancillary equipment and necessitated either
the installation of new systems or the implementation
of an alternative control strategy (low-sulfur coal
combustion and electrostatic precipitators).
2. Lawrence 4 redesign was committed at approximately the
same time that the decision was made concerning the
Jeffrey Energy Center's emission control strategy. The
company decided to incorporate the use of wet particu-
late scrubbers rather than an electrostatic precipitatdr,
primarily because resistivity of the Medicine.Bow
coal fly ash is very high and would require large ESP's
for attainment of 99 percent removal. This would have
necessitated relocation of other plant equipment and,
thus, was deemed impractical.
3. Lawrence 5 redesign was committed soon afterwards.
KP&L elected to employ basically the same strategy as
that developed for Lawrence 4. Many of the components
of Lawrence 5, unlike Lawrence 4, had not been destroyed
during initial phases of operation; the fact that the
air quality control system's original reaction tank,
21
-------
spray-pump system, induced-draft fans, and stack could
all be employed in the redesign gave this plan a
decided economic, spatial, and temporal advantage over
alternative strategies.
4. With the exception of the method of particulate collec-
tion, the emission control strategies developed for
Lawrence and Jeffrey Energy Centers are basically the
same. The installation of these systems at Lawrence
would provide valuable design and operating experience
for future, larger-scale applications at Jeffrey. This
would offer the added benefit that any potentially
costly modifications could be made prior to startup.
PROCESS DESCRIPTION
The limestone scrubbing systems now in service on Lawrence 4
and 5 are second-generation design units supplied and installed
by Combustion Engineering. Basically, both systems encompass the
same general equipment layout, consisting of a common limestone
storage and preparation facility, two rod-deck venturi scrubbers
and spray tower absorber modules, and a common' waste disposal
facility.
The process description provided in the paragraphs that
follow particularly address the Lawrence 4 scrubbing system.
Although the Lawrence 5 scrubbing system is similar in design and
operation, a number of major features that differ are noted and
described at the end of this subsection.
The air quality control system at Lawrence 4 can be described
in terms of three basic operations: (1) limestone handling and
preparation, (2) gas treatment, and (3) waste solids disposal and
pond water return.
Reagent Handling and Preparatixm
Limestone for the Lawience scrubbing systems is trucked from
quarries owned and operated by the N.R. Hamm Company, approxi-
mately 3 km (2 i. i; north of the plant, and stored in an area
sitiiated directly behind the milling facility. It is received as
-------
Removal Efficiency—
,!
Both Lawrence scrubbing systems were designed to remove 99; 3
percent of the inlet particulate and 65 percent of the inlet
sulfur dioxide when high-sulfur Kansas coal was combusted in the
boilers. Actual removal values indicated that these goals were
attained or exceeded. Sulfur dioxide removal efficiencies as
high as 85 percent were achieved over short periods, but only at
the expense of an accelerated rate of scale formation in the
modules, which ultimately required shutdown for cleaning and
reduced system availability.
Future Development
In 1976, having achieved success; with scrubbing operations
at Lawrence, KP&L decided to replace both systems with a second-
generation scrubbing design developed by Combustion Engineering.
There were several reasons for this decision;
1. During modifications and revisions in the scrubber
modules, Lawrence operated at deleterious corrosion
levels, which caused widespread deterioration of the
modules and ancillary equipment and necessitated either
the installation of new systems or the implementation
of an alternative control strategy (low-sulfur coal
combustion and electrostatic precipitators).
2. Lawrence 4 redesign was committed at approximately the
same time that the decision was made concerning the
Jeffrey Energy Center's emission control strategy. The
company decided to incorporate the use of wet particu-
late scrubbers rather than an electrostatic precipitatbr,
primarily because resistivity of the Medicine Bow
coal fly ash is very high and would require large ESP's
for attainment of 99 percent removal. This would have
necessitated relocation of other plant equipment and,
thus, was deemed impractical.
3. Lawrence 5 redesign was committed soon afterwards.
KP&L elected to employ basically the same strategy as
that developed for Lawrence 4. Many of the components
of Lawrence 5, unlike Lawrence 4, had not been destroyed
during initial phases of operation; the fact that the
air quality control system's original reaction tank,
21
-------
spray-pump system, induced-draft fans, and stack could
all be employed in the redesign gave this plan a
decided economic, spatial, and temporal advantage over
alternative strategies.
4. With the exception of the method of particulate collec-
tion, the emission control strategies developed for
Lawrence and Jeffrey Energy Centers are basically the
same. The installation of these systems at Lawrence
would provide valuable design and operating experience
for future, larger-scale applications at Jeffrey. This
would offer the added benefit that any potentially
costly modifications could be made prior to startup.
PROCESS DESCRIPTION
The limestone scrubbing systems now in service on Lawrence 4
and 5 are second-generation design units supplied and installed
by Combustion Engineering. Basically, both systems encompass the
same general equipment layout, consisting of a common limestone
storage and preparation facility, two rod-deck venturi scrubbers
and spray tower absorber modules, and a common waste disposal
facility.
The process description provided in the paragraphs that
follow particularly address the Lawrence 4 scrubbing system.
Although the Lawrence 5 scrubbing system is similar in design and
operation, a number of major features that differ are noted and
described at the end of this subsection.
The air quality control system at Lawrence 4 can be described
in terms of three basic operations: (1) limestone handling and
preparation, (2) gas treatment, and (3) waste solids disposal and
pond water return.
Reagent Handling and -Prepara.ti.on.
Limestone for the Lawxence scrubbing systems is trucked from
quarries owned and operated by the N.R. Hamm Company, approxi-
mately 3 km (2 „.:,; north of the plant, and stored in an area
situated directly behind the milling facility. It is received as
22
-------
1.9-cm (3/4-in.) rock (gravel size) containing 93 percent calcium
carbonate, 6 percent silicas, and 1 percent magnesium carbonate.
After limestone from the storage area has been fed by bucket
elevator to a storage hopper, a weigh feeder transfers it to the
wet ball mill, where it is ground to an 80 percent minus 200 mesh
particle size. The mill effluent, which is approximately a 60
percent solids slurry, is collected in a mill sump. From there,
it is transferred by mill slurry purips (two, one operational/one
spare) to a classification system consisting of a scalping screen
and collection tank. Slurry particles larger than 200 mesh are
collected on the screen and returned to the mill for crushing.
The slurry contained in the classification collection tank'is
transferred by additive transfer pumps to an agitated additive
storage tank. Variable speed pumps (two, one operational/one
spare) transfer the 60 percent solics slurry to a dilution tank,
where it is diluted to 10 percent solids with makeup water (a
blend of thickener overflow and pond return water) collected in
the scrubbing system's recirculatior, tank. The 10 percent solids
limestone slurry is transferred to the spray tower reaction tanks
by additive feed pumps (four, two operational/two spare) at a
rate of 3 liters/s (50 gpm) per module at full load.
As indicated above, the limestone handling and preparation
facility is shared by both Lawrence 4 and 5 scrubbing systems.
Figure 8 shows a simplified process flow diagram of the limestone
handling and preparation facility.
Gas Treatment
Flue gas from the boiler passes through the existing air
heater and is conveyed by new duct work to two unitized 50 percent
capacity scrubber modules, each module consisting of a rectangular,
variable-throat rod-deck, venturi scrubber arranged in series
with a spray tower absorber. Each module is equipped with two
reaction tanks, mist eliminators, reheater, bypass duct, bypass
23
-------
LIMESTONE WATER FOR
to
CRUSHED
LIMESTONE
BUCKET
ELEVATOR
_
nur
^
rtN
\
/
1
-
-------
4
dampers, and isolation dampers. Bypass ducts make possible the
bypass of the scrubber modules during periods when oil or natural
gas is burned in the boiler.
Flue gas at 138°C (280°F) enters the scrubbing system at a
rate of 190 m3/s (403,000 acfm) through two parallel, rectangular,
rod-deck venturi scrubbers, each comprised of a converging gas
section and rod section. The converging gas section directs the
flue gas downward to the rod-deck section, which measures 0.9 m
by 7 m (3 ft by 23 ft) and consists of two staggered levels of
rubber-coated fiberglass rods. The rods, which have an outer
diameter of 16.8 cm (6.625 in.}, are Located on 33-cm (13-in.)
centers. The vertical spacing betweei the two rows of rods 'is
automatically controlled according to gas load in order to insure
a constant gas-side pressure drop across the rod section.
A series of nonatomizing, fan-type spray nozzles located
around the perimeter of the throat araa continuously spray
limestone slurry into the rod-deck scrubber, where an intimate
gas-slurry contact occurs, which facilitates particulate and
sulfur dioxide removal. Spent slurry from the rod section
gravity feeds into a collection tank Located directly below the
venturi. This tank, which has a liquid capacity of 190,000
liters (50,100 gal), retains the slurry for approximately 14 min
to allow for completion of chemical reactions. The slurry is
recycled from the collection tank to- ;he rod-deck scrubber by
means of a slurry recirculation pump one operational/one spare)
at a rate of 227 liters/s (3600 gpm) .
After passing through the rod-deck venturi, the flue gas
makes one 90-degree turn as it approaches the spray tower and
another 90-degree turn before passing upward through the spray
tower at 165 m /s (349,000 acfm). The saturated gas, cooled to
52°C (124°F), flows upward through two levels of sprays in the
open towers, where the gas is contacted by the slurry, which is
sprayed countercurrent to the gas flov. The spray levels, each
of which include four internal spray headers containing six
spray nozzles each, are situated at approximately 3-m (10-ft)
intervals above the inlet duct.
25
-------
Spent slurry from each spray tower gravity feeds into a
reaction tank located directly below the tower. The reaction
tank, which has a liquid capacity of 262,000 liters (69,200 gal),
retains the slurry for approximately 10 min for completion of
chemical reactions and dissolution of fresh limestone additive.
The slurry is then recycled to the spray tower by means -of one
slurry recirculation pump at a rate of 335 liters/s (5300 gpm).
Entrained droplets of moisture and slurry picked up by the
flue gas stream are removed in a mist elimination section
approximately 3m (10 ft) above the spray zone in the spray
towers. Each mist eliminator is an A-frame design comprised of
a bulk entrainment separator followed by two stages of chevron
vanes. Each is equipped with an intermittent, high-pressure,
water-wash system which sprays blended makeup water on the top of
the bulk entrainment separator and the bottom of the first mist-
eliminator stage. Figure 9 shows the mist eliminator design used
in the Lawrence scrubbing systems.
Following passage through the mist eliminators, the saturated
gas stream is reheated by an in-line, carbon steel reheater. One
such reheater, which consists of four rows of circumferential
finned tubes arranged in a staggered fashion, is provided for
each spray tower. The heating medium is hot water from the
boiler feed water deaerator. Two half-track soot blowers located
upstream of the reheaters provide compressed air every 4 hours of
service to keep the reheaters clean. The reheaters boost the
temperature of the gas stream approximately 11°C (20°F), after
which it flows through the ducts leading to the induced-draft
fans and stacks, which discharge it to the atmosphere.
Waste-Solids Disposal and Pond WaterReturn
Waste solids accumulated in the slurry circuits are effec-
tively removed •" the scrubbing system by a sequence of liquid
26
-------
CHEVRON VANES
SECOND
STAGE
FIRST
STAGE
WASHER
LANCE
BULK ENTRAPMENT
SEPARATOR
Figure 9. Diagram of the proprietary mist eliminator design
used in the Lawrence scrubbing systems.
27
-------
staging, forced oxidation, and thickening, which ultimately
produces a 35 percent solids waste stream for disposal in ponds
on the plant site. The supernatant from the ponds is recycled
for additional use. Liquid staging is accomplished by the
separate slurry-hold tanks provided for each rod-deck scrubber
and spray tower absorber. The solids in the reaction tanks are
controlled at the 5 percent level by bleeding slurry via gravity
feed to the collection tanks. At full load, the reaction tank
bleed stream discharges at a rate of approximately 2.5 liters/s
(40 gpm) per module. The solids in the collection tanks are
controlled at the 8 to 10 percent level by varying the flow of
the effluent bleed pump.
Each collection tank is equipped with a forced oxidation
system, which converts virtually all of the sulfite to sulfate by
sparging air through the collection tanks at an air stoichiometry
of 400 percent. This reduces the level of sulfite species in the
scrubbing circuit, thus minimizing the likelihood that hard
sulfate scale will develop in the scrubbers. Forced oxidation
also improves the quality of the sludge because the oxidized
wastes (gypsum) tend to settle out faster and set up harder than
unoxidized wastes.
Each collection tank is also equipped with one effluent
bleed pump which discharges the underflow-to the system's
thickener. The thickener concentrates the slurry to a 30 to 35
percent solids underflow, which is transferred to onsite sludge
disposal ponds. Thickener overflow flows by gravity into a
recirculation (surge) tank. Sludge disposal is provided by a
2
network of three ponds with areas of 16,000 m (4 acres), 65,000
m2 (16 acres) and 113,000 m2 (28 acres). Thickener overflow
enters the 65,000-m2 (16-acre) pond and overflows into the other
two. The supernatanl is returned to the process, where it is
blended with i.L.j.c^erier overflow in the recirculation tank. This
blended water is used for mist eliminator wash, strainer wash,
and maintaining liquid levels in Lne collection and reaction tanks.
-------
Figure 10 shows a simplified process flow diagram of the
Lawrence 4 scrubbing system.
Lawrence 5 Scrubbing System
The design of the Lawrence 5 scrubbing system is very
similar to that of Lawrence 4 in that it contains two scrubbing
modules, each consisting of a rod-deck scrubber in series with a
spray tower absorber, to treat 100 percent of the flue gas from
the steam generator. In addition, the system shares the lime-
stone handling and preparation facilities and the sludge disposal
ponds used by Lawrence 4. Several major features of Lawrence 5
are different, however, and these are summarized briefly in the
following paragraphs.
Gas Conditions--
Medicine Bow coal is burned in both Lawrence 5 and Lawrence
4, but the inlet gas conditions differ significantly: 178 m /s
(3,937,000 acfm) at 149°C (300°F) at Lawrence 5, compared with
190 m3/s (403,000 acfm) at 138°C (280°F) at Lawrence 4.
Scrubber Modules--
The modules are significantly larger to accommodate the
greater flue gas flow and temperature. The rectangular-throat,
rod-deck scrubbers are 1.5 m (5 ft) by 11 m (37 ft), and the
rods, which are constructed of 316L SS Schedule 80 pipe, have an
outer diameter of 1.68 cm (6.63 in.). The flue gas entering the
spray towers is contacted by a single level of slurry sprays
operating in a countercurrent fashion approximately 3 m (10 ft)
above the inlet duct. A single reaction tank equipped with four
agitators and two strainers receives the spent slurry from both
modules, as well as the fresh limestone slurry introduced into
the system. After it has been retained for 10 minutes, the
slurry is recycled to both the rod-deck scrubber and spray tower
of both modules.
29
-------
INLET -
FLUE GAS
TO OTHER
MODULE
BYPASS
I.D. FAN
/•^d
I
MIST
ELIMINATOR
VANES
Q
GAS -
REHEATER-
/
-£^
STACK
BLOWERS
ROD
SCRUBBER
ADDITIVE
rr=jLjZROD SECTION
Y-—"£,.,
SPRAY
TOWER
ABSORBER
POND RETURN
WATER
SPRAYS
WATER
ABSORBER
[ON BLEED
"
SPRAY
PUMPS
EFFLUENT<
BLEED PUMP1
BLOWERS
TO STRAINER
WASHERS
WASH
PUMP
""OH
If
RECIRcl
PUMPS I
RECIRCULATION
TANK
REACTION
TANK
I
D-i
STRAINERl
L
EFFLUENT BLEED
I FROM OTHER
I MODULE
SPRAY
PUMP
WEIR
OVERFLOW
L-€> SETTLING
THICKENER POND
UNDERFLOW
PUMPS
Figure 10. Simplified process flow diagram of one of the two
Lawrence 4 scrubbing modules.
-------
Waste Solids Disposal—
Although the two systems share the same sludge disposal
ponds, Lawrence 5 is not equipped with a liquid staging and
thickening system. Spent slurry (forcibly oxidized by air
sparging) is bled from the system by effluent bleed pumps that
discharge the reaction tank underflow directly to the ponds.
Supernatant is returned to the process and added directly to the
reaction tank, where a 10 percent solids level is maintained for
liquid level control.
Figure 11 shows a simplified process flow diagram of the
Lawrence 5 scrubbing system.
PROCESS DESIGN
Fuel
The Lawrence scrubbing systems were designed to process flue
gas resulting from the combustion of pulverized-coal in the
boilers. The coal is a low-sulfur, subbituminous grade, originat-
ing from mines located in Medicine Bow, Wyoming. Table 8 presents
fuel specifications and consumption rates of the performance
coal.
T^Tehand_Outlet_Gas Conditions and Removal Efficiencies
The inlet and outlet gas conditions of the scrubbing systems
and particulate and sulfur dioxide design removal efficiencies
are summarized in Table 9. The values presented are based on the
performance coal data summarized in Table 8.
Scrubber Modules
Each scrubbing system is equipped with two modules, each
containing a rod-deck venturi scrubber in series with a spray
tower absorber. Whereas Lawrence 4 is equipped with four slurry
hold tanks, Lawrence 5 has only one. Lawrence 5 has less liquid
staging for two major reasons: the existing reaction tank for the
original furnace-injection system was available for use in the
31
-------
to
t-o
TO STACK
I.D. FANS (2)
OUTLET
DAMPER
BYPASS
FLUE GAS FROM
AIR PREHEATER
r
REHEATER
•* • REHEATER BLOWER
MIST ELIMINATOR
BLOWER
STRAINER
WASHER (TYP)
STRAINER
WASH LINE (TYP)
X
ADDITIVE
(FROM MILL)
ROD SCRUBBER
SPRAY PUMP
ADDITIVE FEED
PUMPS (2)
i«
°~T0j TANK
{STRAINERS
ABSORBER"
SPRAY PUMP
ADDITIVE
-STORAGE
TANK
COMMINUTQRD
[EFFLUENT
•Q BLEED
^ PUMP
TO POND
Figure 11. Simplified process flow diagram of one of the two Lawrence 5 scrubbing modules,
-------
TABLE 8. SPECIFICATIONS AND CONSUMPTION RATES
OF PERFORMANCE COALa
Category
Maximum consumption, Mg/h (tons/h)
Heating value, kj/kg (Btu/lb)
Ash, percent
Moisture, percent
Carbon, percent
Sulfur, percent
Chlorine, percent
Ash analysis
Silicon dioxide, percent
Aluminum oxide, percent
Calcium oxide, percent
Ferric oxide, percent
Magnesium oxide, percent
Lawrence 4 Lawrence 5
45 (50) 145 (160)
23,260 (10,000)
9.8
11.8
60.7
0.55
0.03
38.0
23.9
13.2
9.5
3.5
a Analyses are as-received average values.
-------
TABLE 9. INLET AND OUTLET GAS CONDITIONS
AND DESIGN REMOVAL EFFICIENCIES
Category
Lawrence 4
Lawrence 5
Superheater outlet, Mg/h (Ib/h)
'od-deck scrubber inlet
Volume, m3/s (acfm)
Weight, Mg/h (Ib/h)
Temperature, °C (°F)
Sulfur dioxide, ppm
Spray--cower absorber inlet
Volume, m3/s (acfm)
Weight, Mg/h (Ib/h)
Temperature, °C (°F)
Scrubbing system outlet
Volume, rn-Vs (acfm)
Weight, Mg/h (Ib/h)
Temperature, °C (°F)
Sulfur dioxide, ppm
Sulfur dioxide removal effi-
ciency, percent
Particulate removal efficiency,
percent
382 (842,100) 1,272 (2,805,000)
190 (403,000)
585 (1,290,000)
138 (280)
748
165 (349,000)
607 (1,338,000)
51 (124)
171 {363,000)
607 (1,339,000)
62 (144)
200
73
98.9
600 (1,271,000)
1,713 (3,777,000)
149 (300)
748
513 (1,088,000)
1,786 (3,937,000)
52 (126)
551 (1,168,000)
1,788 (3,941,000)
69 (156)
359
52
98.9
-------
new tail-end system, thus providing a substantial savings in
capital and time; and the percentage of sulfur dioxide removal is
substantially less (52 versus 73 percent). Tables 10 and 11
summarize the design parameters and operating conditions of the
Lawrence scrubbing modules and ancillary equipment.
Mist Eliminators
Each module is equipped with its own separate mist elimina-
tor, which is situated in the spray tower horizontal to the gas
stream. The mist eliminators (a proprietary two-stage design)
are preceded by a precollector (bulk entrainment separator).
They are constructed of a fiberglass reinforced plastic (FRP)
capable of withstanding exposure to 205°C (400°F) . Table 12
summarizes design parameters and operating conditions.
Reheaters
Each module is equipped with its own reheater, which is
situated in the spray tower downstream of the mist eliminator.
The reheaters elevate the discharge gas temperature to avoid
downstream condensation and corrosion, suppress plume visibility,
and enhance plume rise and dispersion of pollutants. Table 13
summarizes reheater design and operating conditions.
Draft Losses
Draft losses through both systems (the boilers, stacks, and
ducts) are summarized in Table 14.
Waste Solids Treatment and Disposal
Waste disposal design parameters and operating conditions
are summarized in Table 15. The Lawrence 4 system features a
treatment system that forcibly oxidizes virtually all the sulfite
into sulfate in the slurry hold tanks and a thickener which
concentrates waste slurry to 30 to 35 percent solids prior to
disposal in the sludge ponds. The Lawrence 5 system disposes the
waste slurry directly to the pond.
35
-------
TABLE 10. ROD-DECK SCRUBBER DESIGN PARAMETERS
AND OPERATING CONDITIONS
u>
Category
Number
Type
Flue gas volume, m /s acfm
Flue gas temperature, 0C(°F)
Pressure drop, kPa (in. H2O)
Liquid recirculation rate,
lit.ers/s (gpm)
Liquid-to-gas ratio (L/G) ,
liters/m3(gal/103 acf)
Materials of construction
Venturi approach
Throat
Rod-deck
Slurry hold tanks
Number
Capacity, liters (gal)
Rentention time, min
Agitators, number
Materials of construction
Lawrence 4
Rectangular, vari-
able-throat, rod-
deck venturi
95 (201,500)
138 (280)
2.3 (<>. 0)
227 (2,600)
2.4 (18)
316L SS
316L SS
Rubber-coated
fiberglass (Norel]
rods
189,600 (50,100)
14
1
Carbon steel
Lawrence 5
Rectangular, vari-
able-throat, rod-
deck venturi
300 (635,500)
149 (300)
2.3 (9.0)
656 (10,400)
2.2 (16-)
316L SS
316L SS
316L SS
2,300,000 (600,000)
10
4
Carbon steel
a One slurry hold tank with a liquid capacity of approximately
2.3 million liters (600,000 gal) provides a retention time of
10 minutes for the spent slurry from both modules. Thus, half
of the tank's capacity is provided for the rod-deck scrubbers
and half for the spray tower absorbers.
-------
TABLE 11. SPRAY TOWER ABSORBER DESIGN PARAMETERS
AND OPERATING CONDITIONS
Category
Lawrence 4
Lawrence 5
\
Number
Type
Flue gas volume, m /s (acfm)
Flue gas temperature, °C(°F)
Pressure drop, kPa (in. H2O)
Liquid recirculation rate,
liters/s (gpm)
L/G, liters/m3 (gal/103 acf)
Materials of construction
Slurry hold tanks
Number
Capacity, liters (gal)
Retention time, min
Agitators, number
Materials of construction
Vertical, counter-
current spray
tower
82.4 (174,500)
51 (124)
0.6 (2.5)
334 (5300)
4.1 (30)
316L SS
262,000 (69,200)
10
1
Carbon steel
Vertical, counter-
current spray
tower
257 (544,000)
52 (126)
0.2 (0.8)
656 (10,400)
2.6 (19)
316L SS
2,300,000 (600,000)
10
4
Carbon steel
One slurry hold tank with a liquid capacity of approximately 2.3
million liters (600,000 gal) retains the spent slurry from
both modules for 10 minutes. Thus, half the tank's capacity is
provided for the rod-deck scrubbers and half for the spray
tower absorbers.
-------
TABLE 12. MIST ELIMINATOR DESIGN PARAMETERS
AND OPERATING CONDITIONS
Total number
Number per module
Type
Configuration (relative to gas flow)
Materials of construction
Number of stages
Number of passes per stage
Shape
4
1
Chevron
Horizontal
FRP
3a
3b
A-frame
A bulk entrainment separator is incorporated in the mist
eliminator design to remove medium- rto large-^size droplets
from the gas stream prior to passage through the chevron
vanes. The bulk entrainment separator is, in essence, an
additional mist eliminator stage.
Three passes per chevron stage,
-------
U)
TABLE 13. REHEATER DESIGN PARAMETERS
AND OPERATING CONDITIONS
Total number
Number per module
Type
Heating medium
Number of rows per exchanger
Configuration
Tube size, outer diameter, cm (in.)
Materials of construction
Heating medium source
Energy requirement, percent
4
1
Indirect, in-line
Hot water
4
Staggered, circumferential
finned tubes
2.5 (1.0)
Carbon steel
Deaerator
1.25
Percent of boiler input..
-------
TABLE 14. GAS-SIDE PRESSURE DROP DATA
Category
Bo ler, air preheater, and duct
work, kPa (in. H20)
Rod- deck scrubber, kPa (in. H2O)
Spray tower and discharge duct
work, kPa (in. H-O)
Reheater, 3
-------
TABLE 15. WASTE DISPOSAL DESIGN PARAMETERS
AND OPERATING CONDITIONS
Category
Lawrence 4
Lawrence 5
Waste stream characteristics
Flow, kg/h (Ib/h)
Solids, percent
Treatment method
Disposal ponds
Number
Type 2
Area, m (acre)
Transporaticn rr.cthod
Pond water return,
liters/s (gpm)
Service life, yr
6,075 (13,392) 15,444 (34,048)
30-35 10
Forced oxidation
Onsite, unlined settling ponds
16,000 (4); 65,000 (16); 113,000 (28)
Pipeline
8.2 (130) 16.8 (266)
20
-------
Cleaning ancMWaah, 1ng_jDeviceis_
The Lawrence scrubbing systems are equipped with several
mechanical and automatic cleaning devices designed to insure
trouble-free, low maintenance operation. These devices are
described briefly below:
0 Each slurry hold tank has an in-tank strainer equipped
with an automatic water wash. The strainer, which is a
perforated plate containing 0.5 cm (3/16 in.) holes and
constructed of carbon steel, prevents over-sized
particles from entering the spray system and plugging
the nozzles. After the automatic water wash backwashes
the strainer to prevent solids accumulation, the col-
lected particles are purged from the system as a bleed
stream upstream of the strainer. Figure 12 provides a
diagram of the strainer and wash mechanism.
i-
0 To prevent solids accumulation at the wet/dry interface
each rod-scrubber inlet is equipped with a soot blower,
which provides periodic compressed air at 1.4 MPa (200
psi) „
0 Each mist eliminator is equipped with a water washer
that automatically provides intermittent (once per
day), high-pressure [0.65 to 0.80 MPa (80 to 100 psig)]
wash water. The water washer is located between the
bulk entrainment separator and first chevron stage of
each mist eliminator and pxovides an overspray and
underspray to each of these stages.
0 Two half-track soot blowers, located upstream of each
reheater, provide 1.5 MPa (200 psig) of compressed air
twice per shift for cleaning.
PROCESS CHEMISTRY: PRINCIPAL REACTIONS
The chemical reactions involved in the Lawrence wet-limestone
scrubbing systems are highly complex. Although details are be-
yond the scope of this dis ,'ussion, the principal chemical mechan-
isms are described in the following paragraphs.
The first *"& most important step in the wet-phase absorp-
tion of sulfur dioxide from the flue gas stream is diffusion
-------
OSCILLATING AND
RETRACTING
WASH LANCE
MECHANISM
PERFORATED
PLATE
SOLID PLATE
FROM MIST ELIMINATOR
WASH SUPPLY
SUCTION VALVE
SPRAY PUMP
SUCTION
Figure 12,
Diagram of slurry hold tank strainer
and wash mechanism.
43
-------
from the gas to the liquid phase. , Sulfur dioxide is an acidic
j "•-'.:-•
anhydride that reacts readily to form an acidic species in the
presence of water.
so2| ±
so
2(aq>)
S02(aq») + H2°
In addition, some sulfur trioxide is formed from further oxida-
tiort of the sulfur dioxide in the flue ges stream.
2 1
Because conditions are thermodynamically but not klnetically
favorable, only small amounts of sulfur trioxide are formed.
This specie, like sulfur dioxide, is, an acidic-anhydride that
reacts readily to form an add in the presence of water.
The sulfurous and sulfurio acid compounda> .are polyprotic
species; the sulfurous species is we,,'c and the sulfuric species,
' •'if • • 0
strong. Their di.ssoclai:loi« Into ioni'* .species occurs as follows:
^L j\ ' ~*
tit '•>' / i j UL M~ , !' l V .^ ,, . ' ' i
„ ' ',, ' 1 « ' i, I i ' i ! 1 H
dioxide «to
iors by dissolved
°C f*
* f
e- j> g*
¥ I ?
-------
The limestone absorbent, which is approximately 93 percent
calcium carbonate by weight, enters the scrubbing system as a
slurry (10 percent solids) with water. It is insoluble in
water, and solubility increases only slightly as the temperature
increases. When introduced into the scrubbing system (Lawrence
4 collection tanks, Lawrence 5 reaction tank), the slurry
dissolves and ionizes into an acidic aqueous medium, yielding the
ionic products of calcium, carbonate, bicarbonate, and hydrogen.
raCO.. 1 ^
3f
CaC°3(aq.)
Ca++ + H+ + <
+ «r
CaHCO^ *
^. CaCO- , .
^ 3(aq.)
* -, ++
^ ^ Ca +
++
_^ Ca + HCO^
CO3
The chemical absorption of sulfur dioxide occurs in the
venturi scrubber and spray tower and is completed in the external
recirculation tank. In addition, tho sulfite species accumulated
in the slurry circuit is forcibly oxidized to sulfate in the
recirculation tanks by bubbling air :.nto the tanks at an air
stoichiometry of 400 percent. The sulfate formed by forced
oxidation plus the sulfate species already present in the slurry
(formed by natural oxidate) precipit^ite as calcium salts, and the
•i
scrubbing solution is recycled. Following are the principal
reaction mechanisms for product formation and precipitation.
S03~ + 1/2O2 * > SO
Ca++ + S04= " x CaSO4
CaS04 + 2H20 ZZZ^ CaS04 • 2H20
The hydrated calcium sulfate reaction product, along with the ,
collected fly ash and unreacted limestone, is transferred to the
45
-------
sludge ponds for final disposal. The supernatant is recycled to
the system.
PROCESS CONTROL
The process control networks of the Lawrence limestone
scrubbing systems rely on a significant amount of instrumentation
to provide total automatic control of process chemistry. Included
are sulfur dioxide gas analyzers (DuPont Photometric 460) for all
gas inlet and outlet streams, magnetic flow meters (Foxboro) for
all liquid slurry streams (recirculation, bleed, and feed lines),
pH meters (Uniloc) for all the reaction tanks, and nuclear
density meters for all the collection and reaction tanks. This
instrumentation provides the basis of the control network that
maintains particulate and sulfur dioxide removal efficiencies at
desired levels while preventing the loss of chemical control and
subsequent scale formation, corrosion damage, and/or plugging.
The effect of the Lawrence control network on the performance of
these major functions is briefly described in the following.
Particulate Removal
Particulate removal is maintained by controlling gas-side
pressure drop across the rod-decks situated in the throat area of
each module through regulation of the vertical spacing between
the two rows of rods in response to gas flow. This maintains a
set gas-side pressure drop of 2.25 kPa (9.0 in. H2O) across the
rods and insures particulate removal efficiency at 43 ng/J (0.1
lb/106 Btu) of heat input to the boiler.
Sulfur DiQxide_Removal
Sulfur dioxide removal is maintained by regulating the flow
of limestone to ^' -: scrubbing systems as a function of inlet
0 sulfur. A characterized coal flow signal is used to indicate the
inlet sulfur content of the flue gas, and this signal regulates
the limestone feed rate. The coal How signal will only be re-
lated to inlet sulfur conditions if the sulfur content of the
46
-------
coal is constant, and an operator selected stoichiometry bias
allows correction of the limestone demand signal to account for
change in the coal sulfur content. The sulfur in the coal is
usually constant; therefore, the coal flow signal provides an
accurate indication of the inlet sulfur conditions for all boiler
loads. This allows the limestone feed rate to be accurately
varied for the correct stoichiometry rate throughout the load
range. This permits operation at design removal efficiencies
while preventing the loss of chemical control, which can lead to
formation of hard scale (gypsum), soft scale (calcium sulfite,
calcium carbonate), and/or corrosion. Any of these phenomena can
cause forced outages for cleanout or necessary repairs to damaged
scrubber internals. •"
Spent Slurry Bleed
The spent slurry, consisting of collected fly ash, calcium
sulfate, and unused reagent, accumulates in the slurry circuits,
and must be discharged from the system in order to maintain
system removal efficiency and process chemistry integrity.
In the Lawrence 4 scrubbing system, discharge occurs in the
liquid staging system where the slurry from the reaction tanks
(spray-tower-absorber slurry hold tanks--one 'per module) is bled
to the collection tanks (rod-deck venruri scrubber slurry hold
tanks—one per module). Spent slurry that accumulates in the
slurry circuit of the rod-deck scrubber is discharged from the
collection tanks by variable-drive, effluent bleed pumps. The
solids in the reaction tanks are controlled at the 5 percent
level by a constant gravity-flow bleed stream, which discharges
to the collection tanks; those in the collection tanks are con-
trolled at the 8 to 10 percent level by varying the effluent-
bleed-pump flow. The effluent bleed stream is transferred to the
thickener, where the slurry is concen trated to 30 to 35 percent
solids before it is discharged to the sludge ponds. Solids
content in the collection tanks and thickener is monitored via
nuclear density meters placed in the spray lines.
47
-------
Spent slurry is discharged from the Lawrence 5 scrubbing
system in a manner similar to that described in the above for
Lawrence 4. Notable differences are the lack of selective liquid
staging and thickening in Lawrence 5, which is equipped with only
one reaction tank for scrubbing modules, and the direct transfer
of the effluent bleed stream to the sludge ponds without a preced-
ing thickening step. The solids in the reaction tank are con-
trolled at the 10 percent level by cycling the effluent bleed
pump on and off.
Water Balance
Freshwater, thickener overflow water, and pond return water
are used to compensate for water loss due to evaporation, mist
carryover, water of hydration, and residual liquor trapped by the
wasi$e solids.
Procedures for maintaining water balance in the two systems
differ because of the presence of additional liquid-staging and
thickening equipment in Lawrence 4,. For Lawrence 4, freshwater
is used to slurry limestone prepared in the ball mill. Dilution
water, which is added to the slurry ,. - dilute the solids control
of the mill effluent, originates from the recirculation tank,
which receives pond return water and thickener overflow. This
water is used to maintain liquid levels in the slurry hold tanks
and also for mist eliminator wash and tank strainer wash.
The water balance network is essentially the same for
Lawrence 5 except that, since Lawrence 5 contains no thickener,
pond return water is not the only component of the dilution
water. As in the other system,- this water is used to maintain
liquid level in the slurry hold tank and also for mist eliminator
and tank strainer wash,,
Scale Preventi '..„.._
Sulfate scale* is a chemical phenomenon resulting from general
or ..localized losses of chemical c.^.'.-'rol in the scrubbing system.
It plagues limestone system beceuse thei" pH operating range is
4b
-------
generally in the slightly acidic to neutral range of 5 to 7.
Calcium sulfate is generally formed in the system because of
sulfite oxidation in the slurry circuit. Uncontrolled crystalli-
zation occurs when the system becomes excessively supersaturated
with calcium sulfate, and hard scale forms on the system compo-
nents such as walls, piping, nozzles, and other internals.
This problem is minimized in the slurry hold tanks of the
Lawrence scrubbing systems by controlled desupersaturation, which
is effected by providing calcium sulfate seed crystals for crystal
growth sites, providing and maintaining adequate solids levels in
the slurry circuits, and providing adequate mixing and retention
time in the slurry hold tanks.
Precipitation of calcium sulfate is maintained by providing
a sufficient amount of seed crystals as crystal growth sites in
the slurry circuit and controlling saturation below the critical
supersaturation level. Sufficient seed crystals are miantained
by controlling the percent solids in the slurry circuits (5
percent solids in the Lawrence 4 reaction tanks; 10 percent
solids in the Lawrence 4 collection tanks and the Lawrence 5
reaction tank). Each slurry hold tank is equipped with top-and-
side entry agitators. In addition, the collection tanks provide
a 14-minute retention time and the reaction tanks a 10-minute
retention time.
The sulfates formed by oxidation are discharged from the
systems by the effluent bleed pumps. The Lawrence 4 system is
equipped with a thickener which concentrates the slurry before it
is pumped to the pond on the opposite side of the site, thus
reducing the amount of the solids from the thickener and elimi-
nates the soluble sulfites recycled from the thickener overflow
to the scrubbers. The effluent bleed from the Lawrence 5 scrub-
bers is pumped directly to the ponds that are in close proximity
to the unit.
*Sulfate scale is actually calcium sulfate dihydrate, or gypsum,
commonly referred to in the industr/ as hard scale to differen-
tiate it from the scale formed by deposition of calcium sulfate
hemihydrate commonly referred to as soft scale.
49
-------
SECTION 4
FGD SYSTEM PERFORMANCE
BACKGROUND INFORMATION
The original limestone furnace-injection and tail-end scrub-
bing system retrofitted on Lawrence 4 were started up in November
1968 and operated until mid-September 1976, when it was shut down
to perform a scheduled turbine overhaul, which took 2-1/2 months.
During this time, construction and erection of the new rod-deck
venturi scrubber and spray tower absorber system were completed.
The new system went into service in early January 1977. During
this November 1968 to September 1976 period, the original system
accumulated approximately 27,000 hours of service on coal-fired
flue gas.
The original limestone furnace-injection and tail-end scrub-
bing system (installed as new equipment) on Lawrence 5 was
started up in November 1971 and operated until March 20, 1978,
when it was shut clown to tie the new scrubbing systera into the
flue gas path. The new rod-deck scrubber and spray tower absorber
modules were erected, directly behind the existing system, which
remained in service during construction of the new,system.
Because the new system was dewiigned to use the original reaction
tank, spray pumps, induced --draft fans, and stack, a 4-week outage
was required to complete installation. The new system went into
service on April 14, 1978. During the November 1971 to March 30,
1978, period, the original system accumulated approximately 23,000
hours of servir.^ .... coal-fired flue. gas.
50
-------
OPERATING HISTORY AND PERFORMANCE
Because the new Lawrence 4 scrubbing system was placed in
the flue-gas path approximately 15 months earlier than the
Lawrence 5 system, virtually all the operating information and
data now available reflect the experience of Lawrence 4. Through
the end of September 1978, this system had accumulated approxi-
mately 10,000 hours of service on coul-fired flue gas. It should
be noted that the scrubbing system was bypassed from April 1,
1977, to September 15, 1977, because natural gas was available,
which precluded the necessity of scrubber operations.
During the course of the initial and subsequent operation of
Lawrence 4, a number of preliminary performance tests and a com-
plete acceptance test were performed, Also, corrective measures
were taken to solve a number of mechanical, chemical, and
design-related problems that were encountered. The results of
the acceptance tests, as well as information on problems and
solutions, are provided in the following subsections.
PROBLEMS AND SOLUTIONS
Mechanical Problems
The in-tank strainer washers failed repeatedly during
initial operation and required extensive overhauling. The
failures, which subsequently necessitated overhaul, were at-
tributed to mechanical malfunction oi limit switches, improper
operation, or operator error. Another contributing factor was an
inoperable air compressor that failed to provide forced oxida-
tion and agitation in the cavity behind the strainer, thus
allowing the cavity to become plugged during shutdown periods.
This problem was resolved by operatirg the air compressor.
Limestone slurry is transferred to the reaction tank of each
module by positive-displacement screw-type pumps. The rubber
liners and rotors of the pumps have teen subject to premature
failures, consistently wearing out within 10 to 15 weeks. No
51
-------
corrective action has been taken; rather, the liners and rotors
are replaced prior to complete failure. This approach has been
adopted for several reasons. The pumps accurately control the
rate of limestone slurry flow to each reaction tank and thus are
integral components in maintaining control of process chemistry.
Because the rate of wear of the liners and rotors is predictable,
they can be replaced before complete failure occurs, and finally,
since the entire system has only two additive feed pumps, such
periodic replacement is not costly.
Some minor agitator problems have been encountered. Several
of the rubber-coated blades of the top-entry agitators in the
collection tanks failed and were replaced by the manufacturer.
Bearing failures in the side-entry agitators of the reaction
tanks were attributed to improper lubrication.
A number of small cracks have been observed in the mist
eliminators. Some cracking and failure of pumps and pipes have
been encountered because of freezing and severe winter weather
conditions, especially during the initial phases of operation
when heat tracing and insulation were not completed.
Since' the scrubbing system is located completely outdoors,
the completion of heat tracing and insulation, plus the
erection of enclosures around the spray pumps, resolved many of
these problems. Some freezing and subsequent plugging, however,
have recurred around the clarifier.
Chemical Problems
To date, no major episodes of scaling or corrosion have
occurred in the system. Some minor problems that have had
chemical ramifications concern the maintainance of adequate
solids levels in the reaction tanks. Specifically, during
initial operatic it was determined that water pressure to the
mist eliminator washers was insufficient. Before this problem
was corrected by installing a booster- pump in the wash system,
the frequency of washing had to be doubled to twice every 24
52
-------
hours to compensate for low water pressure and to insure mist
eliminator cleanliness. Because the spent wash water eventually
flows into the reaction tank, doubling the amount of spent wash
water made it difficult to maintain the 5 percent solids level.
This dilution diminished the concentration of sulfate seed
crystals and resulted in sporadic episodes of scaling within the
spray towers. The scale buildup never exceeded 3 mm (1/8 in.)
and was corrected with the insertion of the booster pump, which
made more than one daily cleaning of the mist eliminator
unnecessary.
Design-related Problems
The incoming flue gas comes into contact with slurry sprayed
by nonatomizing fan-type nozzles located around the rectangular
perimeter of the venturi scrubber just above the rod decks.
Because of the abrasive nature of the 10 percent solids slurry
sprayed through these nozzles, sacrificial wear plates were
inserted directly below the nozzles to prevent premature failure
of materials in the converging section of the Venturis. It
should be noted that these wear plates were inserted into the
Venturis after initial startup, durirg the period when natural
gas was fired in the boiler. A materials failure did not occur
here, but it did at another utility installation (Sherburne
County, Northern States Power Co.), which utilizes a similar
scrubber design. The experience Comkustion Engineering gained
there prompted the insertion of wear plates at Lawrence. Time
limitations necessitated making these insertions after startup.
Figure 13 shows the arrangement of the variable-throat venturi
scrubber and rod-decks, including the spray nozzles and wear
plates.
Each module is equipped with three dampers that allow bypass
or isolation during periods of gas/oiL firing, reduced boiler
load, or maintanance. One module is equipped with a double-
53
-------
SPRAY
NOZZLES
ROD
PRAY
./^NOZZLES
16.83 cm (6.625 1n.)
/ 0,0, .ROD
&
Figure 13, Arrangement of variable-throat rod-deck venturi scrubber,
54
-------
louver bypass damper, whereas the other has a top-entry guillotine
damper. A certain amount of gas leakage through these dampers
was observed during a series of preliminary performance tests.
This was corrected immediately by replacing the old seals.
Combustion Engineering also determined that the damper drives
were susceptible to frequent drifting that allowed the dampers to
to move off their limit switches every 5 to 10 minutes, thus
activating controls to drive them back to their original position.
This caused flue gas to bypass the modules and activated nuisance
alarms in the control room. The damper drives have beqn replaced
with redesigned mechanisms by the damper supplier.
The soot blowers located at the inlets of the rod-deck
f
venturi scrubbers were not adequately cleaning the wet/dry
interfaces of solids buildup. The lances were subsequently
modified to obtain better coverage, and have performed adequately
since that time.
A materials failure detected in the FRP slurry spray piping
was related directly to operation of a downstream butterfly
control valve. The valve was throttling flow to the spray tower
sprays, thus creating undue stress on the piping. Corrective
action consisted of opening the valve completely during operation,
thereby eliminating any turbulence and wear on the upstream
piping.
Shortly after startup it was noticed that several spray
pumps required repacking every 10 days. This problem was
resolved by redesigning the seal water system so that the flow
rate of the water was approximately doubled.
SYSTEM PERFORMANCE: DEPENDABILITY, REMOVAL EFFICIENCIES, AND
CHEMICAL CHARACTERIZATION
As indicated previously, Lawrence 4 has accumulated approxi-
mately 10,000 hours of service time since commencing operations
in January 1977, and the problems encountered have been minor in
55
-------
nature. Therefore system availability* during the January 1977 to
September 1978 period was in the 90 to 95 percent range.t
A number of preliminary and acceptance performance tests of
actual particulate and sulfur dioxide removal efficiencies were
conducted by Combustion Engineering during the first year of
operation. Measurements obtained included particulate removal,
sulfur dioxide removal, and opacity, as well as chemical and
physical measurements of'the liquid and solids effluents from the
system. The results of the acceptance performance tests are
provided in Tables 16, 17, 18, and 19, and Figures 14 and 15.
The results of the performance tests, which have since been
corroborated by subsequent operation, indicate ,the following:
the system can achieve sulfur dioxide removal efficiencies as
high as 96 to 98 percent when operating at optimum design con-
ditions; it has demonstrated that a particulate removal capa-
bility in excess of 99 percent of the inlet particulate when the
design pressure drop [2.25 kPa (9 in. H20)] is maintained across
the rod-decks. This translates into an emission-outlet value of
34 ng/J (0.08 lb/10 Btu) heat input, to the boiler when operating
at optimum design conditions, and opacity measurements of between
2 and 8 percent have been achieved on the twin 2.5-m (8-ft)
diameter stacks when operating at optimum design conditions.
Availability index: the number of hours the system is available
for operation (whether operated or not), divided by the number
of hours in the period, expressed as a percentage.
'^This range is a PEDCo Environmental estimate based on performance
information provid* 1 by KP&L and Combustion Engineering. It
should be not^ ' at KP&L doen not maintain separate records or
operating lot-AS ior their scrubber plants. They are considered
part of the power generating facility and as such are logged
accordingly. This precludes the possibility of analyzing the
dependability of the systems independently and presenting actual
performance data other them estimates or ranges.
56
-------
Ul
-J
TABLE 16 SUMMARY OF LAWRENCE 4 SCRUBBING SYSTEM PERFORMANCE--
ANALYSIS OF SOLIDS: OCTOBER 1977
Category"
Mi) , percent
Oxidation, percent
Util ization,
percent
Solids, percent
CaSO • 1/2H-0,
percent
CaSO • 2H90,
percefit
CaCO,, percent
Fly ash, percent
107
0. I/- 0.1
77. 2/97.7
55.9/30.0
7.0/7.9
2.42/0. 32
10.93/18.63
6.46/25.21
80.19/55.84
) 0/7
• O.I/- 0.1
78.6/98.9
62.7/42.0
8.5/7.8
2.42/0. 16
11.82/19.89
5.21/16.09
80.55/63. 91
Tost d
10/18
- O.I/- 0.1
57.4/94 .1
73.8/65.9
12.4/9.0
6.77/1.29
12.18/27.23
4.37/8.75
76.67/62.73
.itc
10/19
O.I/- 0.1
57.6/95.8
79.3/68.5
11.7/8.4
6.12/1.44
11.11/29.56
2.91/8.33
79.85/60.66
10/23
• O.I/' 0.1
56. 3/99. 2
79. 3/90.8
12.8/5.2
6.77/0.16
11.64/27.95
3.12/1.66
78.47/70.22
10/23
O.I/ 0.1
56.7/97.4
83. 2/86.1
12. 0/9.8
6.93/0.64
12.18/32.4
2. 5/2.12
78.39/63.8
Values reported for collection tank and reaction tank.
TABLE 17 SUMMARY OF LAWRENCE 4 SCRUBBING SYSTEM PERFORMANCE-
GYPSUM CRYSTALLIZATION DATA: OCTOBER 1977
Category3
Solids, percent
Gypsum, percent
Gypsum, relative saturation
Sulfur dioxide removal, percent
Oxidation, percent
Gypsum percipitation' rate,
mi 11 imoles/ liter-minute
Forced oxidation
Test date
10/7
8.5/7.8
1.00/1.55
1.41/1.18
225/55
78.6/98.9
0.211/0.047
Yes/Yes
10/18
12. 8/9. 0
1.51/2.45
1.34/1.10
235/55
57.4/94.1
0.116/0.049
No /No
10/23
12.8/5.2
1.49/1.45
1.30/1.12
265/60
56.3/99.2
0.189/0. 055
No/No
10/23
12. 0/9.8
1.46/3.18
1.33/1.18
265/60
56.8/97.4
0.189/0.055
No /No
Values reported for collection tank and reaction tank.
-------
TABLE 18. SUMMARY OF OVERALL PERFORMANCE
OF LAWRENCE 4 SCRUBBING: OCTOBER 1977
ui
00
Test blocks
Cateaory f I II
Inlet sulfur dioxide, ppmaa \ 400-450
Outlet sulfur dioxide, ppni 10-20
Sulfur dioxide removal, percent
Limestone stoichiGiiietry, percent
Limestone utilization, percentb^c
Sulfite oxidation, percent0
Solids, perce ^tc
pHc
Ca++ , ppmc
M.q++ , ppmc
S03=f ppmc
304--, ppmc
Gypsum relative saturation
95.5-97.5
100 j 41
60/38
78/98
8.5/7.8
7.5/6.6
876/715
137/127
106/23
2340/2064
] 45/1.22
CaS03 • 1/2H20, percentd | 2.41/0.20
CaS04 - 2H20, percent^ 111. 57/19. 25
CaCOs, percent^ j 5.85/21.52
75/67
58/95
12.4/8.0
6.8/6.3
801/702
225/210
100/87
2570/2375
1.38/1.21
6.50/1.35
11.65/28.70
3.74/8.59
III
18
81/87
57/98
12.8/5.2
7,7/5.5
781/669
256/214
89/214
2598/2303
1.35/1.15
6.85/0.38
11.78/30.65
2.83/2.35
a Corrected to 3 percent oxygen.
k includes alkali contributed by limestone and fly ash.
c Values reported for collection tank and reaction tank.
Weight percent.
-------
TABLE 19. LAWRENCE 4 SCRUBBING SYSTEM PERFORMANCE SUMMARY: OCTOBER 1977
Date
Test No.
Location
Pdrticulate
loading.
••a./-3
(gr/scf)
Paniculate
•S/"3
(gr/scf)
Opacity. I
Rod section
pressure drop.
kPa
(In. H,0)
(./&.' liters/iu3
(gal/10J acf)
Excess air. 2
Gas temperature .
°C
(°n
«3/s '
(ftVuin)
Load, Ml
10/18/77
1
South
outlet
70.9
(0.031)
100.6
(0.044)
2.5
2 6
(10.4)
2.7/4.1
(20/30)
64.7
63
(145)
106
(228,254)
51
10/10/77
2
South
outlet
50.3
(0.022)
70.9
(0.031)
3.0
2.5
(10-1)
2.7/4.1
(20/30)
67.6
62
(143)
108
(229.301)
52
10/12/77
3
South
outlet
68.6
(0.030)
98.3
(0.043)
2.5
4.0
(16.0)
2.7/4.1
(20/30)
63.3
61
(142)
111
(236,000)
52
10/12/77
4
South
outlet
54.9
(0.024)
77.8
(0.034)
3.0
4.0
(16.0)
2.7/4.1
(20/30)
63.3
62
(144)
109
(231,948)
52
10/14/77
5-
South
outlet
59.5
(0.026)
84.6
(0.037)
2.5
2.6
(10.4)
1.4/4.1
(10/30)
61.5
63
(146)
113
(238.554)
53
10/18/77
6
South
outlet
64.0
(0.028)
91.5
(0.040)
2.5
2.6
(10.4)
1.4/4.1
(10/30)
64.8
63
(145)
108
(228,275)
51
10/18/77
7
South
outlet
73.2
(0.031)
100.6
(0.044)
2.0
2.6
(10.4)
2 7/0
(20/0)
60.2
62
(144)
106
(224,444)
51
10/19/77
8
South
outlet
73.2
(0.032)
105.2
(0.046)
2.0
2.6
(10.4)
2.0/0
(15/0)
60.2
62
(144)
108
(228,951)
51
10/20/77
9
South
outlet
80.0
(0.035)
114.4
(0.050)
2.0
4.0
(16.0)
2.7/0
(20/0)
61.9
62
(144)
109
(231,845)
51
10/24/77
10
South
outlet
73.2
(0.032)
105.2
(0.046)
2.0
4.0
(16.0)
2.7/0
(20/0)
63.9
62
(144)
111
(235,691)
51
10/24/77
11
South
outlet
89.2
(0.039)
128.1
(0.056)
7.5
1.1
(4.5)
2.7/4.1
(20/30)
68.4
64
(147)
65
(138,475)
51
10/24/77
10/25/77
10/25/77
12 ! 13 14
South
outlet
89.2
(0.039)
128.1
(0.056)
7.5
1.2
(4 6!
2.7/4.1
(20/30)
68.4
South ! South
tnUt : inlet
10)7 I 6838
(3.077) j (2.990)
10,040 9765
(4.39) (4.27)
i
(4 5\ '4 •>)
2.7/4.1
(20/30)
2.7/4.1
(20/30)
68.4 68.4
1
64
(147)
65
(137,363)
51
142
(288)
144
(292)
<153'.575)
52
74
(156,623)
52
* Rod-deck scrubber/spray torn ibsortcr value*.
-------
o
en o
PO
2 -o
(C
in
en
a:
=£
a.
0.15
(0.07)
,13
,06)
^ " 0.11
„ 2. (0.05)
0.09
01 •£ (0.04)
0.07
(0.03)
EQUIVALENT TO 43 n§/J
(Q.1/1G6 B)
©2
1.0
(4)
1.5
(6)
2.0
(8)
2.5
(10).
3.0
(12)
3.5
(14)
4.0
(16)
AP, kPt (in. H20)
Figure 14. •Lawrence 4 scrubbing system performance summary -
particulate emission as a function of rod-deck venturi scrubber
differential pressure: October 1977.
-------
10
C1J
o
s-
cu
Q.
O
Q_
O
ALL VALUES CORRECTED
TO 3% 00
LEVEL
0
0.07
(0.03)
0.08
(0.035)
0.09
(0.040)
0.10
(0.045)
PARTICULATE EMISSION, g/nf
(dry basis)
0.11
(0.050)
(gr/scf)
0.12
(0.055)
Figure 15. Summary of Lawrence 4 scrubbing system performance-
particulate emission versus opacity: October 1977.
-------
As indicated above, a number of chemical and physical pro-
cess stream measurements were l.akem to determine reagent usage
and material balance (see Tables 16, 17, and 18). An analysis of
these results provides some interesting conclusions, the most
notable of which is that the alkaline constituents (calcium
oxide, magnesium oxide) in the collected fly ash provide the
major portion of the alk lx in the slurry circuit. This in-
creases sulfur dioxide removal efficiencies during short-term
performance tests and, more importantly, allows reduction in
limestone feed rates during normal operations, thereby providing
a substantial savings in annual costs for reagent consumption.
One disadvantage is that the alkalinity contributed by the fly
ash affects the degree of sulfite oxidation attained in the
collection tanks. Without air addition, oxidation is generally
in the 57 to 58 percent range? whereas air.addition increases the
oxidation to approximately 78 percent,because the additional fly
ash alkalinity increases slurry pH. Since sulfite solubility
tends to decrease with'increasing pH, less sulfite is available
in solution for chemical conversion to sulfate. This could
affect the quality of the sludge and gypsum relative saturation
values.*
FUTURE,OPERATIONS . ' . \ '
Kansas Power and Light Company is now in the process of
developing the Jeffrey Energy Center, a coal-fired power generating
station with a capacity of 2880 MW (gross). This station is
located in Pottawatomie County, Belvue, Kansas, and is composed
.of four 720-MW (gross) coal-fired units, which are scheduled' for
'operation in-October 1978, June 1980, 1982, and 1984. All of . .
These effects nay be overstated. Overall sulfite oxidation in
the systeiv without forced oxidation in the collection tanks is
approximately 98 to 99 percent,- wich forced oxidation it is in
excess of 99.5 percent (assuming air addition in the reaction.
tanks oxidizing 95 to 98 percent of the sulfite). These levels
have had no pronounced effect on sludge quality or system
• chemistry (.
62
-------
these units will fire low-sulfur Gilette (Bell Ayr), a Wyoming
coal supplied under long-term contract with the Amax Coal Company.
The ultimate and ash analyses of this coal are provided in Table
20. The steam generators for Jeffrey 1 and 2 are supplied by
Combustion Engineering, the turbine generators by Allis Chalmers.
In order to meet air emission regulations of the Department
of Health and Environment of the State of Kansas and Federal New
Source Performance Standards, Jeffrey 1 and 2 are equipped with
emission control systems for the control of nitrogen oxides,
particulate, and sulfur dioxide.
The emission control system for each unit is designed and
supplied by Combustion Engineering and includes an overfire" air
system at the tangential-fired-pulverized burners for nitrogen
oxide control, two electrostatic precipitators (ESP's) and
crossover ducts upstream and downstream of the ESP's for particu-
late control, and six pressurized vertical spray towers for
sulfur dioxide control.
The Jeffrey FGD systems consist of six vertical spray towers
(one of which is a spare) for the removal of sulfur dioxide from
75 percent of the flue gas. The remaining 25 percent of the flue
gas is bypassed around the spray towers to provide reheat* to the
scrubbed gas prior to its discharge to the atmosphere through
separate 183-m (600-ft) stacks. Four induced-draft fans (with
respect to the boilers) are located upstream of the pressurized
spray towers. The limestone used in the systems (for sulfur
dioxide removal) is received at the plant as rock and ground by
three wet ball mills with capacities of 11 Mg (12 tons)/h. One
ball mill presently serves Jeffrey 1, one serves Jeffrey 2, and
Only 75 percent of gas at Jeffrey is treated because of lower
sulfur fuel, while Lawrence, having anticipated high sulfur
coal origianlly, cleans 100 percent of gas flow. Consequently,
in-line carbon steel reheaters were required for Lawrence.
63
-------
TABLE 20. JEFFREY AVERAGE ULTIMATE AND ASH COAL ANALYSES
Ultimate analysis
Heating value, kj/kg (Btu/lb)
Ash, percent
Moisture, percent
Carbon, percent
Sulfur, percent
Chlorine, percent
Ash analysis
Silicon oxide, percent
Ferric oxide, percent
Aluminum oxide, percent
Calcium oxide, percent
Magnesium oxide, percent
18,900 (8,125)
5.8
30.0
48.5
0.32
0.01
31.4
4.1
16.2
25.0
4.2
-------
the other is a spare.* Each spray tower has two spray headers
located 4 and 8 m (13 and 26 ft) above the gas inlet. Each
system is equipped with four reaction tanks. Two of these tanks
are shared by two spray towers each and two serve only one spray
tower each. Each tower is also equipped with louver isolation
and bypass dampers that permit module isolation from the gas path
during periods of inactivity (reduced load, spare duty, or main-
tenance) . A mixing chamber in each system permits drying of the
scrubbed gas stream and mixing with the bypass gas stream prior
to discharge to the atmosphere. The mist eliminators are identi-
cal to those at Lawrence (A-frame, two-stage with bulk-entrain-
ment separator, FRP construction), as are the modules, whicti are
constructed of 316 low-carbon stainless steel. Spent slurry
collected in the reaction tanks is bled as a 10 percent solids
slurry to a common transfer tank and then pumped to a settling
pond located approximately 1.6 km (1 mi) from the plant. Water
returned from the pond is used as makeup in the reaction tanks.
Figure 16 illustrates the arrangement of the steam generators
and emission control systems for Jeffrey. Tables 21, 22, 23, and
24 summarize design information and criteria for Jeffrey 1 and 2.
* The ball mills will serve all four planned units at the Jeffrey
site with one spare.
65
-------
FURNACE
DAMPERS
ONE
STACK
TWO PRECIPITATOFS
FOUR I.D. FANS
WATER RETURN TO
REACTION TANKS
SIX SPRAY
TOWERS
FOUR,
REACTION
TANKS
BLEED PUMP
SPRAY PUMP
TRANSFER. TANK
SLUDGE DISPOSAL
POND
Figure 16. Schematic of Jeffrey steam generator and emission control equipment.
-------
TABLE 21. SUMMARY OF JEFFREY 1 AND 2 EMISSION CONTROL SYSTEMS
Unit capacity, MW (gross)
Design coal, source
Steam generator supplier
Turbine generator supplier
Particulate emission rate,
ng/J (Ib/I06 Btu)
Sulfur dioxide emission rate,
ng/J (Ib/I06 Btu)
Emission controls
Particulate
Sulfur dioxide
ESP supplier
ESP type
Number of ESP's
FGD supplier
FGD design
Number of modules
Gas reheat, type
Gas bypass capability
Sludge disposal
Startup date
Jeffrey 1 Jeffrey 2
720
Gilette (Bell Ayr)
Combustion Engineering
Allis Chalmer
43 (0.1)
129 (0.3)
ESP's
Spray tower absorbers
CE-Walther
Cold side
2
Combustion Engineering
Vertical spray tower
6a
Bypass
Yes
Unstabilized/onsite pond
10/78 6/80
Five operational, 1 spare at full load.
67
-------
TABLE 22. SUMMARY OF JEFFREY 1 AND 2 GAS FLOW RATES
cr>
00
Superheater outlet, Mg/h (10 Ib/h)
ESP inlet, Mg/h (103 Ib/h)
m3/s (acfm)
oc (oF)
FGD inlet, Mg/h (103 Ib/h)
m3/s (acfm)
°C (°F)
FGD bypass, Mg/h (103 Ib/h)
m3/s (acfm)
°C (°F)
Stack inlet, Mg/h (103 Ib/h)
mVs (acfm)
°C (°F)
2,290 (5,050)
3,788 (8,351)
1,312 (2,781,000)
135 (276)
2,651 (5,845)
857 (1,815,000)
135 (276)
1,136 (2,505)
334 (708,000)
135 (276)
3,876 (8,545)
1,119 (2,370,000)
77 (170)
TABLE 23. SUMMARY OF JEFFREY 1 AND 2 DRAFT LOSSES
Steam generator, air preheater, duct,
kPa (in. HjO)
ESP, kPa (in. HjO)
Spray tower, duct, kPa (in. H20)
Reheat mixing chamber, kPa (in. H20)
Discharge duct and stack, kPa (in. H2O)
Total, kPa (in. H20)
5
0
1
0
0
7
.16
.28'
.01
.75
.65
.85
(20
(1.
(4.
(2.
(2.
(31
.63)
14)
04)
99)
61)
.41)
-------
TABLE 24, SUMMARY OF JEFFREY 1 AND 2 LIQUID FLOW RATES
Limestone feed, kg/h (Ib/h)
Tower recirculation rate, liters/s (gpm)
Effluent bleed, Mg/h (lb/h)c
Makeup water, liters/s (gpm)
b, c
5500 (12,130)
908 (14,400)
8.6 (19,000)
35 (557)
Dry feed rate.
Per module.
Ten percent solids.
-------
A.
APPENDIX A
PLANT SURVEY FORM
Company and Plant Information
1. Company name:_JKansas Power and Light Company
Main office: Topeka, Kansas
Plant name:
2.
3.
Lawrence, Unit 4
4. Plant location: Lawrence, Douglas County, Kansas
5. Responsible officer: Derek Miller
6. Plant manager: Ron Teeter
7.
8.
9.
Plant contact: Kelly Green
Position; Electric Production Manager
Telephone number:
10. Date information gathered: June 8, 1977
Participants in meeting
Ron Teeter
Bernard Laseke
John Tuttle
Jay Master
Affiliation
Kansas Power and Light
PEDCo Environmental, Inc.
PEDCo Environmental, Inc.
PEDCo Environmental, Inc.
A-l
-------
B. Plant and Site Data
1. UTM coordinates:
2. Sea Level elevation:
3. Plant site plot plan (Yes, No); No
(include drawing or aerial overviews)
4. FGD system plan (Yes, No): Yes
5. General description of plant environs; Located in a
lightly industrialized area on the outskirts of
Lawrence
6. Coal shipment mode(s): rail
C. FGD Vendor/Designer Background
1. Process: Limestone slurrv
2. Developer/licensor: Combustion Engineering
3. Address; 1QQQ Prospect Hill Road,
Windsor, Connecticut 06095
4. Company offering process:
Company: Combustion Engineering
Address 1000 Prospect Hill Road
A-2
-------
Location: Windsor, Connecticut 06095
Company contact; A.J. Snider
Position: Manager, Environmental Control
Telephone number; (203) 688-1911
5. Architectural/engineer:
Company:
Address:
Location:
Company contact:
Position:
Telephone number:
D. Boiler Data
1. Boiler: Lawrence 4
2. Boiler manufacturer; Combustion Engineering
3. Boiler service (base, intermediate, cycling, peak):
Cyclic load
4. Year placed in service; 1959 • •
5. Total hours operation (date):
6. Remaining life of unit:
7. Boiler type; Pulverized coal, (multiple-fuel design)
Balahced-^raft, tangential-fired
8. Served by stack N'O. :
9. Stack height; 36 m (120 ft)
10. Stack top inner diameter; 2.5 m (8 ft)
13. Unit ratings (MW):
Gross unit rating: 125
Net unit rating without FGD:
A-3
-------
Net unit rating with FGD; -\
Name plate rating:
12. Unit heat rate:
Heat rate without FGD:
Heat rate with FGD: 10,900 kJ/kWh (10,300 Btu/kWh)
13. Boiler capacity factor, (1977 ) ; 55 to 60
14. Fuel type: Coal
15. Flue gas flow rate:
Maximum: 190 m3/s (403,000 acfm)
Temperature; 138°C (280°F)
16. Total excess air:
17. Boiler efficiency:
E. Coal Data
1. Coal supplier(s):
Name(s):
Location(s):
Mine location (s): Medicine Bow
County, State:_ Wyoming
Seam:
2. Gross heating value; 23,260 kJ/kg (10,000 Btu/lb)
3. Ash (dry basis); j.8 (as received)
4. Moisture: 11.8
5. Sulfur '-•=-y basis); 0.55 (as received)
6. Chloride: 0.03 _______
7. Ash composition (See Table Al)
A-4
-------
Table Al
Constituent Percent weight
Silica, Si02 38-°
Alumina, A120, 23.9
Titania, Ti02
Ferric oxide, Fe203 9.5
Calcium oxide, CaO . 13.2
Magnesium oxide, MgO 3-5
Sodium oxide, Na20
Potassium oxide, K~0
Phosphorous pentoxide, PoO,-
Sulfur trioxide, SO.,
Other
Undetermined
F. Atmospheric Emission Regulations
1. Applicable particulate emission regulation
a) Current requirement: 43 ng/J (0.1 lb/10 Btu)
Regulation and section:
b) Future requirement;
Regulation and sections
2. Applicable S02 emission regulation
a) Current requirement; 129 ng/J (0.3 lb/106 Btu)
Regulation and section No.:
b) Future requirement:
Regulation and section?
A-5
-------
Chemical Additives; (Includes all reagent additives -
absorbents, precipitants, flocculants, coagulants, pH
adjusters, fixatives, catalysts, etc.}
1. Trade name: Limestone
Principal ingredient; Calcium carbonate (93%), silicas (6%),
Magnesium carbonate(1$)~~~
Function; Absorbent
Source/manufacturer: N.R. Hamm Company
Quantity employed;
Point of addition; Reaction tank
Trade name:
Principal ingredient:
Function:
Source/manufacturer:
Quantity employed:_
Point of addition:
Trade name:
Principal ingredient:
Function:
Source/manufacturer:
Quantity employed:
Point of addition:
Trade name:
Principal ingredient:
Function:
Sour1"".,' -;.nuf acturer:
Quantity employed:
Point of addition:
A-6
-------
5. Trade names
Principal ingredient:
Function:
Source/manufacturer:
Quantity employed:
Point of addition:
H. Equipment Specifications
1. Electrostatic precipitator(s) Not applicable
Number: ....
Manufacturer:
Design removal efficiency:
Outlet temperature:
Pressure drop:
2. Mechanical collector(s) Not applicable
Number:
Type: -
Size: ;
Manufacturer:
Design removal efficiency:
Pressure drop:
3. Particulate scrubber(s) In conjunction with SO2 absorber
Number: 2
Type: Rectangular variable-throat, rod-deck venturi
Manufacturer: Combustion Engineering
Dimensions; 0.9 m x 7 m (3 ft x 23 ft)
Material, shell: 316L SS _ :
A-7
-------
Material, shell lining; None
Material, internals; Rubber-coat ad fiberglass (Norel) rods
No. of modules per train; 1 _ _ _ _ -
No. of stages per module: 1 _ ' -
No. of nozzles or sprays: _ ___ _ _ -
Nozzle type; Nonatomizinq, fan-type sprav -
Nozzle size: _ • _ . - _ - . -
Boiler load capacity; 50% each train _ _ -
95 ra3/s (201,500 acfm)
Gas flow and temperature; ^ ],38 °c (?R °v\
Liquid recirculation rate-. 227 liters/s (3600 gal/min) each
Modulation : _ _ _ _ - _ -
L/G ratio; 2.4 liters/s m3 (18 gal/103 acf) _
Pressure drop; 2.3 kPa (9.0 in. H00) -
Modulation : _ _ _ _ --
Superficial gas velocity;
Particulate removal efficiency (design/actual):
Inlet loading: .—
Outlet loading:
S02 removal efficiency (design/actual):
Inlet concentration: 748 ppm
Outlet concentration:
S02 absorber(s)
Number:
Type: ''' .tical, countercurrent spray tower
Manufacturer: Combustion Engineering
Dimensions:
A-8
-------
Material, shell; 316L SS
Material, shell lining; None
Material, internals; FRP (spray headers)
No. of modules per train; 1
No. of stages per module; 2 spray levels
Packing/tray type; None
Packing/tray dimensions: Not applicable
No. of nozzles or sprays; 24 per level
Nozzle type; Spinner vane
Nozzle size: 220 gpm
Boiler load capacity: 50% each train
82.4 m3/s (174,500 acfm)
Gas flow and temperature: at 51 °C (124 °F) each train.
Liquid recirculation rates 334 liters/a (5300 gpm)
Modulation:
L/G ratio; 4.1 liters/m3 (30 gal/acf)
Pressure drop; 0.6 kPa (2.5 in.. H?.Q)
Modulation:
Superficial gas velocity:
98.9 (venturi
Particulate removal efficiency (design/actual) ; and _ gp_r_a.y
tower combined^)
Inlet loading: \
Outlet loading
S09 removal efficiency (design/actual)s 73 (venturi and spray
^ tower combined)
Inlet concentration; See particulate scrubber
Outie>_ concentration: 200 ppm
Wash water tray(s) Not applicable
Number:
-------
Type: ___...,- .
Materials of construction:
Liquid recirculation rates
Source of water:
6. Mist eliminator(s)
Number: Two' one per scrubbing train
Type: Chevron
Materials of construction; FRP
Manufacturer:
Configuration (horizontal/vertical); Horizontal
Number of stages. ^Jwo^plus^one^^ separator
Number of passes per stage:£hfee^Jchevron_stage) _
Mist eliminator depth; : _
Vane spacing: _____-™. — •
Vane angles: _
Type and location of wash ByBtemi_Intermltt^^
water wash directed to top of bulk entrainment separator
and bottom of chevrons.
Superficial gas velocity:
Freeboard distance:
Pressure drop:______
Comments: __
7. Keheater(s):
Type (check appropriate category):.
A-10
-------
X
in-line
indirect hot air
direct combustion
bypass
exit gas recirculation
waste heat recovery
other
Gas conditions for reheat:
Flow rate; 171 m3/s (363,000 acfm)
Temperature: 62°C (144°F)
SO- concentration; 200 ppm
Heating medium; Hot water
Combustion fuel; Not applicable
Percent of gas bypassed for reheat; Not applicable
Temperature boost (AT) ; 11°C (20°F)
Energy required; 1.25% of boiler output
Comments: Staggered, circumferential-finned tubes
constructed of carbon steel _____
8. Fan(s)
Number : _2
Type: Induced: draft
Materials of construction; Carbon steel
Manufacturer; __
Location: Downstream of reheater
Rating: ,
Pressure drop:
A-ll
-------
Recirculation tank(s):
Number : 4, two per train (collee :ion, tank. a.nd_ £9 .sg..U,p.n tank)
Materials of construction; Carbo.n steel
Function: Slurry retention, bleed, and limestone addition
Configuration/dimensions: Circular
Capacity; 262,000 liters (69.200 gal) (reaction tank)
190,000 liters (50,100 gal) (collection tank)
Retention time; 1_Q miry (absorber) ; 14 min (venturi)
Covered (yes/no); No '
Agitator: One per tank
10. Recirculation/slurry pump(s):
Number : 2 (1 spare)
Type:
Manufacturer:
Materials of construction:
Head:
Capacity:
11. Thickener(s)/clarifier(s)
Number: 1
Type: Denver
Manufacturer:
Materials of construction; Carbon steel
Configuration:
Diameter: 50 ft-
Depth: 10 ft-
Rake speed:
Retention time:
12. Vacuum filter(s) Not applicable
A-12
-------
Number:
Type:
Manufacturer:
Materials of construction:
Belt cloth material:
Design capacity:
Filter area:
13. Centrifuge(s) Not applicable
Number:
Type :
Manufacturer:
Materials of construction:
Size/dimensions:
Capacity:
14. Interim sludge pond(s)
Number: 1
Description; Unlined pond
Area: 65,000 m (16 acres)
Depth:
Liner type:
Locations Onsite
Service Life: 20 yr
Typical operating schedule:
Ground water/surface water monitors:
15. Final disposal site(s)
A-13
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Number : TWO
Descriptions Qnlined settling ponds
Areas i« noo m2
Depths
Location: Onsite
Transportation mode; Pipeline
Service life: 20 yr
Typical operating schedule; Continuous
16. Raw materials production
Number: One for Units 4 and 5
Type: Wet ball mills
Manufacturer:
Capacity; 12,OOP Ibs/h
Product characteristics: 80% <200 mesh particle size
I. Equipment Operation, Maintenance, and Overhaul Schedule
1. Scrubber(s)
Design life: .^.^^
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Clea* j^•„-duration:
Other preventive maintenance procedures; Soot blower to
prevent solids accumulation at wet/dry interface
2. Absorber(s)
A-14
-------
Design life:
Elapsed operation time:
Cleanout method:
Cleanout frequency; Maintenance performed as needed
Cleanout duration:
Other preventive maintenance procedures:
3. Reheater(s)
Design life:
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Cleanout duration:
Other preventive maintenance procedures; Soot blowers
upstream of each reheater
4. Fan(s)
Design life;
Elapsed operation time:
Cleanout method: .
Cleanout frequency; Maintenance performed as needed
Cleanout duration:
Other preventive maintenance procedures:
5. Mist eliminator(s)
Design life:
Elapsed operation time:__
A-L5
-------
Cleanout method; Wash water sprays
Cleanout frequency; Continuous/intermittent
Cleanout duration; Intermittent spray once per day
Other preventive maintenance procedures:
6. Pump(s)
Design life:
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Cleanout duration:
Other preventive maintenance procedures:
Vacuum filter(s)/centrifuge(s) Not applicable
Design life: .
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Cleanout duration:
Other preventive maintenance procedures:
Sludge disposal pond(s)
Design life:_
Elap ea operation time:
Capacity consumed:
Remaining capacity s
A-16
-------
Cleanout procedures:
J. Instrumentation See text of report
A brief description of the control mechanism or method of
measurement for each of the following process parameters:
0 Reagent addition:
Liquor solids content:
0 Liquor dissolved solids content;
0 Liquor ion concentrations
Chloride:
Calcium:
Magnesium:
Sodium:
Sulfite:
Sulfate:
Carbonate:
Other (specify)
A-17
-------
0 Liquor alkalinity:
Liquor pH:
Liquor flow:
0 Pollutant (S02, particulate, N0x) concentration in
flue gas; ...... _
0 Gas flow:
0 Waste water
0 Waste solids:
Provide a diagram or drawing of the scrubber/absorber train
that illustrates the function and location of the components
of: the scrubber/absorber control system.
Remarks:
K. Discussion of Major Problem Areas:
• • See the main body of the report concerning
•
uroblem areas
A-18
-------
2 Erosion: See tne main body of the report concerning
problem areas
3. Scaling; See the main body of the report concerning
problem areas
4. Plugging; See the main body of the report concerning
problem areas
5. Design problems; See the main body of the report
concerning problem areas
6. Waste water/solids disposal; See the main body of the
report concerning problem areas
A-19
-------
7. Mechanical proble'ms; See the main body of the report
concerning problem areas —
L. General comments:
A-20
-------
APPENDIX B
PLANT SURVEY FORM
Company and Plant Information
1. Company name: Kansas Power and Light Company
Main office; Topeka. Kansas
Plant name: Lawrence, Unit 5
2.
3.
4. Plant location: Lawrence, Douglas County, Kansas
5. Responsible officer; Derek Miller
6. Plant manager: Ron Teeter
Plant contact; Kelly Green
7.
8. Position: Electric Production Manager
9. Telephone number:
10.
Date information gathered:
Participants in meeting
Ron Teeter
June 8. 1977
Bernard Laseke
John Tuttle
Jay Master
Affiliation
Kansas Power and Light
PEDCo Environmental, Inc.
PEDCo Environmental, Inc.
PEDCo Environmental, Inc.
B-l
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B. Plant and Site Data
1. UTM coordinates:
2. Sea Level elevation:
3. Plant site plot plan (Yes, No); NQ
(include drawing or aerial overviews)"
4. FGD system plan (Yes, No): yes
5. General description of plant environs; Located in a
lightly industrialized area on the outskirts of
Lawrence
6. Coal shipment mode(s): rail
C. FGD Vendor/Designer Background
1. Process: Limestone
2. Developer/licensor; Combustion Engineering
3. Address: ,___JLOP_Q_Prospect Hill Road.
Windsor, Connecticut 06095
Company tfering process:
Company: Combustion Engineering
Address: 1000 Prospect Hill Road
B-2
-------
Location: Windsor. Connecticut 06095
Company contact; A.j. Snider_
Position: Manager, Environmentalj-nn^^ 1
Telephone number; (203) 688-1911
5. Architectural/engineer:
Company:
Address:
Location:
Company contact:
Position:
Telephone number:
D. Boiler Data,
1. Boiler; Lawrence 5
2. Boiler manufacturer .-^Combustion E
4.
5.
6.
7.
B.
9.
10.
11.
3. Boiler service (base, intermediate, cycling, peak)
Cyclic load
Year placed in service: 1971
Total hours operation (date)::
Remaining life of unit:
Boiler
I by
Stack height:_ll4_i[L_Q75L I
Stack top inner diametor:
Unit ratings (MW):
Gross unit rating: 420
Net unit rating without FGO:
B-3
-------
Net unit rating with FGD: 400
Name plate rat ing :____
12. Unit heat rate:
Heat rate without FGD:
Heat rate with FGD; 10,900 kJ/kWh (10,300 Btu/kWh)
13. Boiler capacity factor, (1977) ; 55 to 60
14. Fuel type; Coal
15. Flue gas flow rate:
Maximum: 600 m3/s (1,271,000 acfm)
Temperature: 149°C (300°F)
16. Total excess air: 18 to 20
17. Boiler efficiency:
E. CoaI_Data
1. Coal supplier(s) :
Name(s):
Location(s):
Mine location(s); Near Medicine Bow
County, State: Wyoming
Seam:
2. Gross heating value; 23,260 kJ/kg (10,000 Btu/lb)
3. Ash (dry basis): 9^j3_
4. Moisture: 11.8
5. Sulfur ' y basis): 0.55 (as received)
6. Chloride: 0.03
7. Ash composition (See. Table Al)
B-4
-------
Table Al
Constituent r'ercent weight
Silica, SiO2 38.0
Alumina, A120., 23.9
Titania, Ti02
Ferric oxide, Fe2O^ 9.5
Calcium oxide, CaO 13.2
Magnesium oxide, MgO 3.5
Sodium oxide, Na20
Potassium oxide, K20
Phosphorous pentoxide, P2°5
Sulfur trioxide, SO,
Other
Undetermined
Atmospheric Emission Regulations
1. Applicable particulate emission regulation
a) Current requirement: 43 ng/J (0.1 lb/106 Btu)
Regulation and section:
b) Future requirement:
Regulation and section:
Applicable SO2 emission regulation
a) Current requirement: 215 ng/J (0.5 lb/106 Btu)
Regulation and section No.:
b) Future requirement:
Regulation and section:
B-5
-------
G- Chemical Additives; (Includes all reagent additives. -
absorbents, precipitants, flocculants, coagulants, pH
adjusters, fixatives, catalysts, etc.)
1. Trade name: Limestone
Principal ingredient; Calcium carbonate (93%) , silicas (6%)
magnesium carbonate (1%)
Function: Absorbent
Source/manufacturer: N.R. Hamm.Company
Quantity employed:
Point of addition; Reaction tank
Trade name:
Principal ingredient:
Function:
Source/manufacturer:
Quantity employed:
Point of addition:
Trade name:
Principal ingredients
Function:
Source/manufacturer:
Quantity employed:
Point of addition:
Trade name:
Principal ingredient:
Function:
Source/manufacturer:
Quant, ty employed:
Point of addition:
B-6
-------
5. Trade name:
Principal ingredient:
Function:
Source/manufacturer:
Quantity employed:
Point of addition:
H. Equipment Specifications
1. Electrostatic precipitator(s) Not applicable
Number:
Manufacturer:
Design removal efficiency:
Outlet temperature:
Pressure drop:
2. Mechanical collector (s) Not applicable
Number:
Type;
Size:
Manufacturer:
Design removal efficiency:
Pressure drop:
3. Particulate scrubber(s) In conjunction with SO2 absorber
Number: 2
Type; Rectangular-throat , variable-throat, rod-deck venturi
Manufacturer : Combustion Engineering
Dimensions: 1. 5 m (5 ft) x 11 m (37 ft)
Material, shell: 316L SG
B-7
-------
Material, shell lining: Non«
Material, internals = __116L_SS_|rodsl
No. of modules per train: one
No. of stages per module; pne
No. of nozzles or sprays: 44
Nozzle
Nozzle size: 235 gpm
Boiler load capacity; 50% each train
r f, -. 300 m-Vs (635,000 acfm) '
Gas flow and temperature; at 149 °C (300 °F) each
Liquid recirculation rate: 656 liters/s (10.400 cral/min)
Modulation:
L/G ratio>. 2. 2 liter s/m3 J_T6_gal/j£J^fL.
Pressure drop; 2.3 kPa (9.0 in. H20)
Modulation:
Superficial gas velocity:
Particulate removal efficiency (design/actual):
Inlet loading:__
Outlet loading:
SO2 removal efficiency (design/actual):
Inlet concentration: 748 ppm .
Outlet concentration:
S02 absorber(s)
Number: Two
Type •._J^rticalj:_countercurrent spra^jbowers
Manufacturer ;___Comb_ustlon Engineering
Dimensions:
B-8
-------
Material, shell: 316L SS
Material, shell lining: None
Material, internals; Headers of PRP
No", of modules per train: One
No. of stages per module: One level of spray
Packing/tray type: None
Packing/tray dimensions: Not applicable
No. of nozzles or sprays: 48 per module
Nozzle type: Spinner vane
Nozzle size:
Boiler load capacity; 50% each train
257 m-Vs (544,000 acfm)
Gas flow and temperature; at.52 °C (126 °F) each
656 liters/s
Liquid recirculation rate: (10,400 gal/min) each
Modulation:
L/G ratio; 2.6 liters/m3 (19 gal/103 acf) each
Pressure drop; 0.6 kPa (2.5 in. IUO)
Modulation:
Superficial gas velocity:
Particulate removal efficiency (design/actual) :and
T , . n tower combined
Inlet loading: _
Outlet loading:
S02 removal efficiency (design/actual) :
Inlet concentration; See parti
Outle^ concentration; 359 ppm
T , . , . spray tower combined)
Inlet concentration; See particulate scrubber
Wash water tray(s) Not 'applicable
Number :
B-9
-------
Type:
Materials of construction:
Liquid recirculation rate:
Source of water:
6. Mist eliminator(s)
Number: Two, one per train
Type: Chevron
Materials of construction: FRP
Manufacturer:
Configuration (horizontal/vertical):Horizontal
Number of stages;Two plus one bulk entrainment separator
Number of passes per stage: Three (chevron stage)
Mist eliminator depth:_
Vane spacing: ,
Vane angles: ____________
Type and location of wash system: Intermittent, high-pressure
water wash directed to top of bulk entrainment separator
and bottom ot clievrons. ~~~~ ' "~~~
Superficial gas velocity;
Freeboard distance:
Pressure drop:
Comments:
7. Reheater(s):
Type (check appropriate category)
B-10
-------
X
in-line
indirect hot air
direct combustion
bypass
exit gas recirculation
I | waste heat recovery
other
Gas conditions for reheat:
Flow rate: 551 m3/s (1.168,000 acfm)
Temperature: 69°C (156°F)
S02 concentration: 359
Heating medium: Hot water
Combustion fuel: Not applicable
Percent of gas bypassed for reheat; Not applicable
Temperature boost (AT): ll°c (20°F)
Energy required: 1.25% of boiler output
Comments: Staggeredf circumferential-finned tubes
constructed of carbon steel
Fan(s)
Number:
Typo: _I nduced_draf t
Materials of construction: Carbon steel
Manufacturer:
Location : ___Dg_Wjistream oj:_ceh3ater
Rating:
Pressure drop:
B-ll
-------
9. Recirculation tank(s):
Number: 1
Materials of construction: Carbon steel
Function: Reaction and recirculation
Configuration/dimensions;__48_ft dia x 31 ft high
Capacity: 2.3 x 106 liters (600,000
Retention time: 10 min
Covered (yes/no): No
Agitator: 4
10. Recirculation/slurry pump(s):
Number:
Type:
Manufacturer:
Materials of construction:
Head:
Capacity:
11. Thickener(s)/clarifier(s) Not applicable
Number:
Type:
Manufacturer:
Materials of construction:
Configuration:
Diameter:
Depth:
Rake speed:
Retention time:
12. Vacuum filter(s) Not applicable
B-12
-------
Number:
Type:
Manufacturer:
Materials of construction:
*
Belt cloth material:
Design capacity:
Filter area:
13. Centrifuge(s) Not applicable
Number:
Type:
Manufacturer:
Materials of'construction:
Size/dimensions:
Capacity:
14. Interim sludge pond(s)
Number: One (shared by Units 4 and 5)
Description; -Unlined pond
Area: 65,000 m2 (16 acres)
Depth:
Liner type:
Location: Onsite
Service Life: 20 yr
Typical operating schedule:
Ground wa*ter/surface water monitors:
15. Final disposal .site (s)
B-13
-------
Number !_Twg (shared by Units 4_ _and_5)
Description;_____J[Jnlined settling ponds
Area: _JL1 i222jJL_Ji__acrc)£)j _Ji^OO_ml>.121>_a£Eesi.
Depth:
Location: Onsite
Transportation mode; Pipeline
Service life; 20 yr
Typical operating schedule:
16. Raw materials production
Number: One for Units 4 and 5
Type; Wet ball mill
Manufacturer: KVS
Capacity; 12,000 Ibs/h
Product characteristics: 80% <200 mesh particle size.
Equipment Operation, Maintenance, and Overhaul Schedule
1. Scrubber(s)
Design life:
Elapsed operation time:
Cleanout method:
Cloanout frequency:
Cleanout duration:
Othc:: preventive maintenance procedures: Soot blower to
prevent solids accumulation at wet/dry interface
2. Absorber(s)
B-14
------- OCR error (c:\conversion\JobRoot\000002MS\tiff\20006M2I.tif): Unspecified error
-------
Cleanout method; Wash water sprays
Cleanout frequency: Continuous/intermittent
Cleanout duration: Intermittent spray once per day
Other preventive maintenance procedures:
6. Pump(s)
Design life:
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Cleanout duration:
Other preventive maintenance procedures:
7. Vacuum filter(s)/centrifuge(s) Not applicable
Design life:
Elapsed operation time:
Cleanout method:
Cleanout frequency:
Cleanout duration:
Other preventive maintenance procedures:
8. Sludge disposal pond(s)
Design life:
Elapsed operation time:
Capacity consumed:
Remaining capacity:
L-16
-------
Cleanout procedures:
J. Instrumentation see text of report
A brief description of the control mechanism or method of
measurement for each of the following process parameters:
Reagent addition:
Liquor solids content:
Liquor dissolved solids content:
Liquor ion concentrations
Chloride:
Calcium:
Magnesium:
Sodium:
Sulfite:
Sulfate:
Carbon:1 te:
Other (specify)
B-17
-------
Liquor alkalinity:
Liquor pH:
Liquor flow:
Pollutant (SO,,, particulate, NO ) concentration in
^ 5C
flue gas:
Gas flow:
Waste water
Waste solids:
Provide a diagram or drawing of the scrubber/absorber train
that illustrates the function and location of the components
of the scrubber/absorber control system.
Remarks:
K. Discussion of Major Problem Areas:
1. Corrosion: See the main body of the report concerning
prcbxem areas
B-18
-------
2. Erosion; See the main body of the report concerning
problem areas
3. Scaling; See the main body of the report concerning
problem areas
4. Plugging: See the main body of the report concerning
problem areas
5. 'Design problems; See the main body of the report
concerning problem areas
6. Waste water/solids disposal; See the main body of the
report concerning problem areas
B-19
-------
7. Mechanical problems; See the main body of the report-.
concerning problem areas?
L. General comments:
B-20
-------
APPENDIX C
PLANT PHOTOGRAPHS
C.-l
-------
Photo 1. View of Lawrence Energy Center. At left is Lawrence 5,
including coal bunkers, steam generator, and carbon steel stack.
Photo 2. View of new Lawrence 5 scrubbing system under construc-
tion. The original marble-bed modules, which are located behind
the new modules, remained in service virtually throughout the
construction period.
C-2
-------
TECHNICAL REPORT CATA
If lease rcad/nstmcitotu on llic n. urj< /• Ion taxtnli tirn'i
1 REPORT NO.
EPA-600/7-7£-mb
TSR t C I Pl I N T 'S AC CESSION NO.
4. TITLE AND SUBTITLE
Survey of Flue Gas Desulfurizatior
Systems:, Lawrence Energy Center, Kansas Power ard
Light Co.
5 RE PC'HT DATE
_ August, 18 76
£, PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
Bernard A. Laseke, Jr.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
PEDCo Environmental, Inc.
11499 Chester Road
Cincinnati, Ohio 45246
8 PERFORMING ORGANIZATION REPORT NO.
PN 3470-1-C
tO PROCfRAM ETifMENT NO.
E HE 62 4
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
11. CONTRACT/GRANT NO.
68-02-2603, Task 24
13 TYPE OF REPORT AND PERIOD COVERED
Final: 7/78 - 12/78
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES IERL-RTP project officer is Norman Kaplan, Mail Drop 61, 919/
541-2556. E.PA-650/2-75-057e is an earlier report on this same station.
16. ABSTRACT
This report describes the results of a survey cf operational flue gas desul-
furization (FGD) systems on coal-fired utility boilers in the United States. The
FGD systems installed on Units 4 and 5 at the Lawrence Energy Center of the Kansas
Power and Light Company is described in terms of design and performance. The FGD
system installed on each unit consists of two parallel two-stage scrubber modules,
each of which includes a rectangular, variable-throat rod-deck venturi scrubber
arranged in series with a spray tower absorber. Each system is also equipped with
slurry-hold tanks, mist eliminators, and in-line reheaters, as well as isolation
and bypass dampers. The two systems share a common limestone storage and pre-
paration facility and waste-disposal facility. These FGD systems represent a
second generation design replacement of limestone furnace-injection and tail-end
scrubbing systems which were originally installed on Units 4 and 5 in 1968 and
1971, respectively. The original systems operated approximately 27,000 hours
and 23,000 hours on coal-fired flue gas for Units 4 and 5, respectively. The
redesigned FGD system on Unit 4 went into service in early January 1977. The
Unit 5 FGD system went into service on April 14, 1978.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Flue Gases
Desulfurization
Fly Ash
Limestone
Slurries
Ponds
Scrubbers
Coal
Combustion
Cost Engineering
Sulfur Dioxide
Dust Control
Air Pollution Control
Stationary Sources
Wet Limestone
Particjlate
13B
21B
07A.07D
116
08H
21D
14A
07B
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
123
20. SECUF ITY CLASS (This page)
Unclas n'fied
22. PRICE
EPA Form 2220-1 (9-73)
C-3
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