REPORT ON A STUDY
OF THE ALEXANDRIA, VIRGINIA INCINERATOR
This report (SW-12ts) was written by
TOBIAS A. HEGDAHL
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Environmental Health Service
Bureau of Solid Waste Management
1970
-------
Single copies of this publication will be distributed as supplies
permit. Address requests to the Bureau of Solid Waste Management,
Office of Information, 5555 Ridge Avenue, Cincinnati, Ohio 45213-
-------
FOREWORD
Incineration is an important method of solid waste processing in
the United States, and although over 300 incinerators are in operation,
little information on the performance of these units is available. It
is therefore not surprising that the effects of incineration on the
environment are little understood and frequently ignored.
An incinerator discharges effluents into the environment in three
states: solid, liquid, and gaseous. The sources of these effluents
are the processes of combustion, gas cleaning, and residue quenching.
Any determination of the pollution contribution to the environment by
incineration must be concerned with all these effluents.
The Bureau of Solid Waste Management, through the Division of
Technical Operations, has initiated a testing program to characterize
the performance of incinerators of different designs and configurations.
The primary objectives of this program are to produce basic information
that identifies the results of the incineration process and to develop
reliable sampling methodology.
During the studies it is considered necessary to make a complete
analysis of all features that affect the operation of the facility as
well as those that influence its potential for environmental pollution.
The operation of the facility is not altered in any way unless specific
i i i
-------
study objectives dictate a change. Therefore, no special effort is
made to operate the facility at its design capacity; rather, it is
tested at its "operating" capacity.
Reports from each study in this program will be prepared primarily
for use by the management of the facility, although they will be
available upon request to other interested technical personnel. Each
report will contain only the data obtained during one individual study.
Data comparisons with other studies will not be made in individual
study reports. Summaries and comparisons of the data from all studies
will be reported annually.
--RICHARD D. VAUGHAN, Direotov
Bureau of Solid Waste Management
-------
CONTENTS
INTRODUCTION 1
SUMMARY 3
DESCRIPTION OF ALEXANDRIA, VIRGINIA, INCINERATOR 5
Operating Procedure 5
Plant Layout , 6
«
Incinerator Design 8
Maintenance , 1*4
METHODS AND PROCEDURES 17
Input and Output Measurements 17
Sampling Techniques 18
RESULTS 23
Overall Plant Efficiency 23
Stack Tests 25
Incoming Solid Waste and Residue Composition 27
Heat Contents and Burning Efficiency 27
Liquid Effluents 30
Cost Analysis 32
REFERENCES 38
ACKNOWLEDGMENTS 39
-------
APPENDICES ............................ 41
A Example Calculations for the Ash, Volatile, and
Heat Content of the Solid Waste ............... 43
B Example Calculations for the Ash, Volatile, and
Heat Content of the Residue ................. kj
C Plant Efficiency Calculations ................ 51
TABLES
1 Incinerator Performance Data ................ 24
2 Stack Effluent Data ..................... 26
3 Composition of Solid Waste ................. 28
4 Composition of Residue Samples ............... 29
5 Solid Waste, Residue, and Fly Ash Heat Contents ....... 29
6 Volatile and Ash Content .................. 30
7 Liquid Effluent Analysis .................. 31
8 Total Annual Cost ...................... 33
9 Annual Operating Cost by Cost Center ............ 35
10 Breakdown of Annual Repair and Maintenance Cost ....... 36
11 Cost Projections for Full Capacity ............. 37
A-l Proximate Analyses of the Combustible Portion
of the Solid Waste Samples ................. 43
A-2 Conversion of the Separation Data to a Dry Basis
B-l Proximate Analyses of the Unburned Combustibles
and Fines .......................... 47
B-2 Conversion of Residue Separation Data to a Dry Basis .... 48
VI
-------
FIGURES
1 General Layout of Alexandria, Virginia, Incinerator 7
2 Furnace Schematic of Alexandria, Virginia, Incinerator ... 9
3 Scrubber Schematic of Alexandria, Virginia, Incinerator ... 12
k Incinerator Cost Centers, Alexandria, Virginia 3^
VI I
-------
REPORT ON A STUDY OF THE ALEXANDRIA, VIRGINIA, INCINERATOR
The Division of Technical Operations of the Bureau of Solid Waste
Management provides technical information and assistance to public and
private agencies, organizations, and individuals throughout the country.
In October 196? Mr. Leroy Stone, Solid Waste Management Representative,
Bureau of Solid Waste Management, Region III was contacted by the City of
Alexandria, Virginia, regarding the possibility of having their incinerator
tested. The city was interested in finding out if recently made changes
in furnace operation had affected particulate emissions. Since the
National Air Pollution Control Administration had conducted stack-emission
tests in April 1967, before the changes in operation were made, a direct
comparison would be possible.
Testing the incinerator would not only satisfy Alexandria's need for
stack-emission data, it would also further the Division of Technical
Operation's efforts to develop basic information about the environmental
pollution potential of incinerators. A study was, therefore, conducted
from May 18 to 25, 1968.
-------
SUMMARY
The burning rate of each furnace during the study week, May 20-24,
1968, averaged 6.42 tons per hr, slightly more than rated capacity. The
plant was designed to burn 6.25 tons of solid waste per hr per furnace,
or 300 tons per day for both furnaces, with a heat content of 5,000 Btu
per Ib. Laboratory analysis revealed that the gross heat content available
in the incoming solid waste averaged approximately 4,300 Btu per Ib.
Annual figures indicate, however, that based on a 5~day week, the plant
burns an average of 250 tons per day. This can be explained partly by
the fact that when the supply of solid waste is low, one furnace is shut
down. When operating, however, the furnaces do burn close to design
capaci ty.
The average particulate-emission rate with one furnace operating
was 0.88 gr per standard cubic foot (scf) corrected to 12 percent C0?.
With both furnaces operating, the average emission rate was 1.12 gr per
scf at 12 percent C02-
The National Air Pollution Control Administration had conducted
stack-emission tests on the incinerator in April 1967, before an increase
in underfire air was made to reduce slag buildup on the grates. The
average of their three tests with both furnaces operating was 0.26 gr
per scf at 12 percent CO-.
-------
All wastewater from the plant operation is discharged into the
city sewer system. In both the residue-quench and fly ash scrubber
systems, water is recirculated for 1 week before discharge. Makeup
water is obtained from the city water supply. The extreme acidity
that occurs in the fly ash scrubber water necessitates a soda ash
neutralization system to protect equipment from corrosion.
The plant employs 2k full-time personnel to work the three shifts
each day. Solid waste is burned Monday through Friday, and the plant is
open until noon on Saturday to receive waste. The cost of plant operation
was $4.90 per ton of solid waste burned. The total cost per ton,
including depreciation came to $7.26.
Total weight-reduction efficiency of the incinerator was approximately
68 percent on a dry basis. The residue contained an average of 2.0
percent volatiles, and the fly ash had 13.9 percent volatiles. Total
weight reduction of volatiles was approximately 99 percent. Approximately
99 percent of the available heat was released during incineration.
The operation of the plant was well managed. Complete records of
the data taken from the instrumentation are kept on file for possible
future reference. The working atmosphere was clean, and employees did
their jobs effectively.
-------
DESCRIPTION OF ALEXANDRIA, VIRGINIA, INCINERATOR
Operating Procedure
The Alexandria, Virginia, municipal incinerator is located in the
southeastern section of the city at 5301 Wheeler Avenue. It was placed
in operation in October 1966 and handles the solid waste generated by
household, commercial, and industrial sources in Alexandria and Cameron
Station. The total population served numbers about 100,000. Operating
funds are provided from the municipal budget.
Plant operation is under the administrative control of the director
of public works, but the plant superintendent is directly in charge of
the day-to-day operation. The plant operates three shifts a day and
requires 2^4 full-time employees. Both the foreman and the superintendent
have offices at the plant. Employees understand their jobs and perform
them efficiently.
All trucks using the incinerator are required to secure a tag that
is valid for 1 year. When the tag is issued, the tare weight of the
vehicle is recorded. A full-time operator is on duty during the hours
the plant is open to receive solid wastes, and all incoming trucks are
weighed on semi-automatic scales of 45,000-lb capacity. The residue
and fly ash trucks leaving the plant while the operator is on duty are
also weighed. Normally, estimates are made on the weights of residue
-------
and fly ash that are removed when the scales are closed. During the study,
however, all fly ash and residue were weighed to enable reduction-efficiency
calculations to be made.
The incinerator is open to receive solid waste from 7 am to 5 pm on
weekdays, and from 6 am to 12 noon on Saturday. Both furnaces are fired
up on Monday morning and are usually run continuously until Wednesday
evening or Thursday morning, when one is shut down because the supply of
solid waste is usually insufficient to keep both furnaces in operation
all week. The furnace is fired up again Thursday evening or Friday
morning, and both furnaces are run continuously until very early Saturday
morning, when the pit is emptied. The solid waste coming in Saturday
morning remains in the pit until operation begins Monday.
Inflammable liquids and hazardous dusts such as pulverized coal,
flour, and sawdust are excluded from the incinerator. Any material
that the plant foreman feels may be harmful to the operation is also
rejected and hauled to a landfill.
Plant Layout
The incinerator is located in an industrially zoned area with no
residences in the immediate vicinity. A fence with two lockable gates
borders the entire plant, and the area (Figure 1) is well landscaped
and free of 1i tter.
The plant structure is of conventional brick design with one storage
pit and a covered, ventilated tipping area that can accommodate eight
trucks at a time. The storage pit is 111 ft long, 23.5 ft wide and
-------
N
Figure 1. General layout of Alexandria, Virginia, incinerator.
-------
32 ft deep. It has a level capacity of approximately 3,000 cu yd and
is capable of storing 2 days of solid waste.
The building has four floors. A large meeting room and the residue
dumping area are on the ground floor, the furnaces and offices are
located on the second floor, the employee facilities are on the third
floor, and the charging hoppers are located on the fourth floor.
The plant environment is very clean, with a charging floor, tipping
area, furnace room, and residue-disposal area that are nearly dust and
odor free. Temperatures are not excessive in any working area. Drinking
fountains and soft-drink machines are located throughout the plant, and
employees have access to a refrigerator and stove in their lunchroom. A
large locker room is also available for employees to shower and dress.
Incinerator Design
Furnaces. The incinerator was designed to burn 300 tons per 2k hr
of operation. The two identical, continuous-feed furnaces have rocking
grates and a common 200-ft stack (Figure 2). Each is designed to burn
6.25 tons per hr, or 150 tons per day. The design was based on a solid
waste heat content of 5,000 Btu per Ib.
Combustion gases are partially cleaned by passing them through a
water-spray baffle scrubber. Residue from both furnaces is water-quenched
in a common tank and removed by conveyor. The highly acidic scrubber
water is neutralized with soda ash before being pumped to a settling
basin, where the resulting sediment is removed with a conveyor.
-------
o
C£
g&
5§
" "^
L^
\
\
\
\
\
s
\
s
\
s
\
s
\
s
\
\
s
s
s
s
V
3
U
L/
<
L
"2.
C
H
u
a
< h-
Q oo
O CQ
<-> ^
LU O
LU
Qi
LU ^
CQ U
CQ <
CK °°
U Q
oo z
O <
U
k\\\\\\\X\\\X\\\\\\X\\\\\
O
4->
TO
(U
c
U
c
TO
C
01
"D
C
TO
X
(U
TO
1)
-C
O
(/>
0)
o
nj
c
L.
3
CN
QJ
-------
The furnace chambers were manufactured by Plibrico.* The primary
combustion chamber is approximately 3^ ft long, 8 ft wide, and 8 ft
high. The brick refractories are 8 in. thick.
An automatic hydraulic system controls tne three separate sections
of grates (manufactured by Flynn and Emrich), which can be set to rock
at various speeds and in various cycles. The grates nearest the
residue-quench tank are usually run one-fifth as fast as the middle
grates. The first section of grates is essentially for drying, and
most of the burning occurs on the next two sections. Approximately
30 min are required for solid waste to pass from the charging hoppers
to the residue-quench tank.
A thermocouple located in the secondary combustion chamber is
connected to a buzzer alarm that rings when the temperature exceeds
1,450 F. Operating experience has shown that when this temperature
is reached in the secondary combustion chamber, the temperature is
high enough in the primary chamber to cause slagging and refractory
deterioration. Adjustments are then made in grate speeds and/or
auxiliary air to lower the temperature.
Each furnace is equipped with underfire and overfire air fans
that are rated at 19,000 cfm each, with the dampers fully open. The
underfire air fan is usually run with the damper half open, which is
equal to about 75 percent of the available fan capacity. Overfire
air fans are usually operated with the dampers one-eighth open, which
is equal to about 20 percent of the fan capacity. A 200-ft stack
"The mention of commercial products does not imply endorsement by
the U.S. Public Health Service.
10
-------
provides the necessary natural draft for removal of combustion gases
from the combustion chamber.
Charging System. Solid waste is charged into the furnace hoppers
with a 2.5-cu-yd grapple attached to a P S H overhead crane of ^-ton
capacity. A standby crane is not available. The operator sits in an
enclosed moving cab and feeds each furnace through separate charging
hoppers. The solid waste is fed both by gravity and by the movement
of the furnace grates from the charging hoppers, through the charging
chutes, and into the furnaces. The charging chutes are water-cooled to
protect them from excessive heat buildup.
Air Pollution Control Equipment. After the combustion gases leave
the primary combustion chamber they pass through a flue into the secondary
combustion chamber before entering the spray-baffle scrubber (Figure 3).
A set of pressurized nozzles spray water down the firebrick baffle walls
from above. The combustion gases make two 90° turns while passing
through the baffle walls, thus causing the particulates to impinge
upon the wetted surfaces where some are entrained in the water droplets.
Water is pumped through the scrubber system at a rate of 500 gpm. The
scrubber water, laden with fly ash, is processed through a fly ash
settling basin and pumped back to a sump tank for recirculation. Before
entering the settling basin, however, the water is treated with soda ash
to reduce the extreme acidity of the water. Sedimentation and neutrali-
zation are the only treatments the scrubber water receives before its
once-a-week discharge into the city sewer system. Replacement and make-
up water come from fresh city water. Make-up water is pumped through
11
-------
o
tn
<
e>
iiiiiiini
cc
UJ
CD
2
<
I
o
-*':
< :£
'''/
IIIIIIIIIT
"""""^
0)
c
o
c
fO
c
O)
a
c
m
x
0)
03
(U
o:
o_
0)
-Q
o
ro
0)
L.
O)
12
-------
the charging chute cooling system before it is utilized in the scrubber
and residue-quench systems.
Residue and Fly Ash Removal Systems. The residue from each furnace
falls off the last section of grates into a common quench tank where it
is removed by conveyor to a truck. The plant is equipped with a reserve
quench tank and conveyor system. A movable flap gate diverts the residue
to one system or the other, and in this way, plant operation is not
impeded if a conveyor fails. The water from the residue-quench tank is
recirculated at a rate of 300 gpm from a sump tank that is separate from
the scrubber-water sump tank. The material that settles out in the sump
tank is removed Monday morning when fresh water is added. The residue-
quench water, untreated except for sedimentation, is discharged into
the city sewer system at this time.
The sludge from the bottom of the fly ash settling basin is removed
by conveyor to a truck. Both residue and fly ash were weighed during
the study, then hauled to a disposal site located on Wheeler Avenue about
i mile from the plant. The disposal site is leveled off and covered about
four times a year.
Instrumentation. The incinerator is equipped with an upright Honeywell
instrument panel located on the furnace floor between the two furnaces.
Controls for regulating the hydraulic grates are located on each furnace.
The instrument panel contains continuous-recording circular charts that
record readouts of temperatures for each secondary combustion chamber
as well as the temperature in the stack. Underfire and overfire air-
pressure gauges are located on the instrument panel. Air flow is
13
-------
regulated by adjusting the dampers. The stack draft and the vacuum
between the breeching and the combustion chambers are indicated on gauges
located on the instrument panel. A continuous-recording circular chart
indicating smoke opacity is also on the panel. Manual readings of water
temperature in the water-cooled charging chutes are taken hourly with a
thermometer to indicate possible heat buildup in the chutes.
Each furnace is controlled by an operator who monitors the instrument
panel and makes necessary adjustments in grate speeds and overfire and
underfire air to keep combustion as efficient as possible. If temperatures
in the secondary combustion chamber become too high (about 1,450 F) , a
buzzer alarm rings and necessary adjustments are made. The degree of
burnout in the residue is observed to determine whether grate speeds
should be changed to vary the residence time of the solid waste in the
furnace. The furnace temperature and the completeness of combustion can
also be regulated by varying the overfire and underfire air. These
methods are used in combination to obtain the desired operating conditions.
Readings are taken every hour from all instrumentation and filed for
future reference. The charts from the continuous recorders are also
kept on file.
Mai ntenance
Minimal corrective maintenance has been required in most aspects of
plant operation, but problems with clinker buildup on the grates did
develop soon after the plant was opened. The problem was alleviated
by increasing the underfire air rate. The increase in underfire air
-------
resulted in excessive fly ash blowover into the secondary combustion
chamber, which reportedly lowered the pH in the scrubber water. To
prevent the acidic water from corroding the pumping and settling basin
equipment, a soda ash neutralization system was added. This treatment
takes place after the water is drained from the scrubbers and before it
enters the settling basin. The cost of the treatment is about $2,500
per yr. When the cost of the grate replacement is compared to the cost
of the neutralization system after the underfire air rate was changed,
the expenditure was certainly justified. However, as discussed later
under Results, the increased underfire air probably did substantially
increase stack emissions. During the first year and a half of operation,
a total of 98 grate sections were replaced, but most of them were re-
quired before the changes in the underfire air rate were made. Each
grate section costs $2^0 and requires about 1 hr to replace.
Routine maintenance work is done on Monday mornings before the
furnaces are fired. The only other maintenance that has been required
has been patchwork on the refractories and frequent repairs on the smoke
opacity meter.
15
-------
METHODS AND PROCEDURES
The methods and procedures used in this study were designed to give
an overall view of the potential for air, water, and land pollution that
the incinerator has on the surrounding environment. The study was also
undertaken to provide information on the characteristics of solid wastes.
During the week of the tests, the incinerator was operated normally,
which meant that one furnace was shut down on Thursday, May 23. Four
stack tests were performed while both furnaces were operating; two were
performed with one furnace operating. Sampling of all effluents was
done simultaneously.
Input and Output Measurements
All incoming solid waste is weighed on the incinerator scale before
it is dumped into the storage pit. Efforts were made to obtain a more
accurate measurement of the charging rate while stack tests were being
conducted Ly weighing the grapple loads on a platform scale before they
were charged into the furnace. Difficulties were encountered in keeping
the crane cables slack and in keepsng the solid waste in the grapple
while weighing, thus making it impossible to gather more definitive data.
The average charging rate over the study week was determined by
dividing the total number of furnace operating hours into the number of
tons of solid waste received and burned from May 18 to 2k, 1968. The
-------
residue and fly ash were also weighed during the study week to determine
the reduction efficiencies.
Sampling Techniques
Incoming Solid Waste. Samples of incoming solid waste were taken
on Monday, Tuesday, and Wednesday. The solid waste samples were obtained
by dumping a partial grapple load of what was considered typical waste
(determined by visual inspection) onto a plastic drop cloth on the charging
floor. The sample was then separated into the following nine categories:
Combustibles: Noncombustibles:
Food wastes Metal products
Garden wastes Glass and ceramic
Paper products products
Plastics, rubber, and Ash, dirt, and rocks
leather
Textiles
Wood
After separation, materials in each of the categories were weighed.
The total sample weight was then calculated, and the percent by weight
of each category was determined. Using these percentages, a 10- to 15-lb
sample was reconstituted by weight from the combustible categories.
Noncombustibles were assumed inert and were excluded from this sample to
make the laboratory grinding less troublesome. Laboratory analysis of
the sample included determinations of moisture content, heat content,
percent volatiles, and percent ash. The analysis indicated that adequate
precautions to protect against moisture loss were not taken, thus making
it necessary to estimate the moisture content. Once the sample was
well mixed and dried, the volatile and ash analyses were performed on
18
-------
a portion of the sample according to procedures outlined in Appendix A
of Tentative Methods of Analysis of Refuse and Compost in Mun icipal
Refuse Disposal.1 The heat content was determined on a well miAed,
dry portion of the sample in the Parr Adiabatic Calorimeter by the
method outlined in the Parr Instrument Company's Manual Number 130.2
Res i due. Furnace residue samples were taken on Tuesday, Wednesday,
and Thursday of the test week for determination of burning efficiency.
Approximately 15 gal of residue were caught in a 30-gal drum as it was
discharged from the residue conveyor. The sample was allowed to dry for
several hours and was then separated by hand Into three categories:
metals, glass and rocks, and unburned combustibles and fines.
After the larger pieces of unburned combustibles (glass, metal,
and rock) were removed, the remainder of the sample was sifted through
a i-in. mesh screen to remove the fines. The weight of each category
was recorded, and all the unburned combustibles and fines were returned
to the laboratory for analysis. The remainder of the sample was discarded
and assumed to contain no heat, moisture, or volatiles. Laboratory
analysis of the residue was the same as for the Incoming solid waste
except that the moisture content was determined from one sample taken
from the conveyor in a 6-gal plastic container that was tightly sealed
to guard against moisture loss during shipment to the laboratory.
Fly Ash. Fly ash samples were taken from the fly ash conveyor.
A 1-gal composite sample was taken for the 3 days of stack testing and
was returned to the laboratory for the same analyses that were made
on the solid waste and residue.
-------
S_t£d£jijFfJjjen_tJ._ The majority of time and effort during the week was
devoted to sampling the stack effluent. Monday was spent in setting up
the sampling equipment. Two tests were made on both Tuesday and Wednesday
when both furnaces were operating, and two tests were made on Thursday
when only one furnace was operating.
The two stack sampling ports were located 100 ft above the ground
and l80 degrees apart. Equipment was set up on a catwalk located at this
level, TVelve points across the diameter of the stack were sampled during
each test. Each point was sampled for E> min, making a total sampling
time of 1 hr, SEX of the points were sampled from each port. Approximately
15 min were required to move the sampling probe between the ports during
the test. The sampling was done approximately 10 stack diameters up
from the top of the breeching at the base of the stack. The maximum
velocity head encountered during testing was 0.32 in. of water. A 3/8-
in. diameter nozzle, wa-j used on che sampling probe. Two particulate
coiU-ction boxes were required per test because of plugging problems
encountered wHh t*e glass fiber filters. The plugging occurred because
of part i cu i .3i~e huiUup o>'> the filter, which prevented maintenance of
isokinetic sampling conditions.
The procedures used in stack sampling are described in the publication
Specifications for Incinerator Testing at Federal Faci1ities3 and the
addendum to that publication. The particulate samples returned to the
laboratory were analyzed according to the procedures outlined in that
publi cation .
20
-------
Liquid Effluent. Liquid samples of 1 liter were taken from the
residue quench tank and the fly ash settling basin during each day of
stack sampling. Half of each sample was collected during the mcrning
tests and half during the afternoon tests. It was not possible to
collect samples of the scrubber water before the neutralization process.
The samples were sealed, labeled, and returned to the laboratory for
determination of solid, chemical, and biological characteristics. The
samples were analyzed according to procedures outlined in Standard
Methods for Examination of Water and Waste Water.** Separate grab samples
were collected and delivered to the Alexandria Sanitation Department
where BOD tests were performed.
21
-------
RESULTS
Overall Plant Efficiency
During the week of the study, 1,271.8 tons of solid waste were
received and burned. With the furnaces operating a total of 198 hours,
the average burning rate was 6.1*2 tons per furnace per hour. The storage
pit was emptied before and after the study week, and all incoming solid
waste and solid effluents were weighed during the week. The burning
rates of the furnaces could not be determined on a daily basis because
burning was not continuous and the solid waste was not completely burned
until the end of the week. The moisture contents for the residue and
fly ash were obtained from single samples taken for that purpose.
Laboratory data for the moisture content of the incoming solid waste
were unrealistically low (5 to 15 percent), considering that the wastes
were visibly wet. This indicates that not enough precaution had been
taken in sealing the sample containers for shipment back to the laboratory.
An estimated moisture content of 20 percent was assumed for all calculations
(Table 1).
The overall weight reduction efficiency for the week was approximately
68 percent, weight reduction in volatiles was approximately 99 percent,
and the percentage of heat released was approximately 99- These calcula-
tions are shown in Appendix C.
23
-------
<
a
LU
o
^
0
LU
CC
0-
QC
0
1-
2
z
o
z
'
. .
4-1
a> in
C I-
*£ O
0)
Q.
O
3
4-J
3
O
4-J
a.
c
a)
O CM
ro
c
i- O
3 C
^
ft) C
O
0> xjj
14-
L-
3 C
+» OJ >.
.- C s '
o o
a: u
in in
4-J (0 C
-^
,_x_
4-1 Q)
JC 3
D1T3 ^-^
VI
P
O O
31 0
- O
i- in
Q
CL) ^
1- 4-J
4-J 0) (J^
in 4-J
. c
O O
^. O
0)
l/l "O
ro a) ^-~,
3 > in
c
o o O
O 4-J
- 0) -
O i-
-------
Stack Tests
A total of six stack tests was conducted during the study week.
The results of the particulate emissions tests are expressed in three
different ways (Table 2.)
A spectrographic analysis of the particulate matter collected on
the filter paper used during the stack tests was conducted to determine
the metallic elements present in the stack effluent. The most prominent
elements were aluminum, lead, tin, and zinc, but none were present in
great quantity.
Because a qualified smoke reader was not available during the study
and the smoke opacity meter on the instrument panel was not functioning,
a comparison of the Ringlemann number to particulate loadings could not
be made.
The National Air Pollution Control Administration had conducted
stack-emission tests on the incinerator in April 196?, before the increase
in underfire air was made to reduce slag buildup on the grates. The
average of their three tests with both furnaces operating was 0.26 gr
per scf at 12 percent carbon dioxide, which may be compared with this
study's average of 1.12 gr per scf at 12 percent carbon dioxide with
both furnaces operating (Table 2). The increased turbulence caused by
the additional underfire air appears to have increased particulate
emissions by a factor of approximately four. The sampling techniques
and equipment used for the two studies were identical except that the
National Air Pollution samples were taken at only two points along the
stack diameter, compared with the 12 points used during this study.
25
-------
1-
o
h-
CM Z
UJ
LU =>
-I _l
CO LJL.
< U-
1- LU
^/
O
1
CO
in
C
o
in
.If!
E
(U
(U
(0
^
3
O
1 i
«J
Q-
(1)
i i
M- U)
O *TJ
2
c
O -D
4-1 <1)
\ O)
j"> ^
_i ro
u
i_
^
5
nj CM
0
i; o
<4_
O d^>
in CM
0
0) ^
4J L.
ro _c
tn
-o c
V O
(U 4->
U. '
in
(U
in
c to
.- O)
0 O
t_J (0
4_l
I/I
4-1
in
0)
OLAO-3- LA OOP^OO
LAOOCM -3- O LA
CT»M>CMv£> OO OO O CTv
^ CM
r^ r^> OA CM CM CA CA oo
cr\voooo r^o oo
o o o o
J- -3- -3- -3- 1 CM CM 1
OO OO OO OO 1 -3- -3- 1
1 ««|
CM CM CM CM vO vO
CM LA Cf\ ' 1 CA CM 1
-3- CA <>A OA ! -3- CA !
"ro ^-.x- x,-.,-^ ^~,^
E CM CM rA rA
UCMCMCMCM (OCMCM
O I I I I Eli
CLALALALA L.LALA
S-^ *** S-^ ' v«_^* QN^^-X_^
in c
0) CM OA-3- LA\D
U (U
(^' (U O** *)
COOOO O) (TJOO O)
1-CCCC (D CCC (D
3 1- !_ I-
l4_4J4-)4-J4J Q) 34->4-l 0)
inininin > 4-inin >
-Cs
l_
"O
u.
o
*^
c
o
*
1 1
-o
c
0
o
-a
i_
OJ
-o
c
OJ
4-1
CO
-X
-------
Incoming Solid Waste and Residue Composition
A total of seven samples was separated (Table 3) on an as received
basis into nine categories during the week of the study. Three residue
samples were separated to determine their composition during the week of
the study (Table k).
Heat Contents and Burning Efficiency
Laboratory analysis to determine heat content was performed on the
incoming solid waste, residue, and fly ash by standard bomb calorimetry
(Table 5). The data for the solid waste are representative of the solid
waste as received at the incinerator. Data for the fly ash and residue
are on a dry basis. Appendix A shows the methods for calculating the
data for the solid waste, and Appendix B shows the methods for calculating
the data for the residue and fly ash.
For the three samples analyzed, the incoming solid waste had an
average gross heat content of A,320 Btu per Ib. This is below the 5,000-
Btu-per-lb design heat-release rate, but the heat content can fluctuate
considerably because of seasonal variation in solid waste composition.
The furnace residue had an average gross heat content of about 200 Btu
per Ib, and the composite fly ash sample contained 180 Btu per Ib.
The laboratory analyzed the combustible portion of the solid waste
samples for the percent volatiles and ash (Table 6). The noncombustibles
were discarded in the field after their percentage by weight of the total
sample had been determined. The percent volatiles and ash for the total
27
-------
LU
O
UJ
_1 U.
m o
<
1- z
0
COMPOS ITI
T3
0)
(D
in
V
4-1
o
" C
O M-
co
vO
1
CM
CM
1
00
VO
1
CM
CM
1
CO
\0
1
CM
1
CO
VO
1
CM
I
CO
v£>
I
O
CM
1
00
v£>
I
O
CM
1
CO
vO
O
CM
Component ,-.
> »>
$
*e
J3
iff
-Q
**
J3
**
J3
.^
.a
(3-9
_a
*c
J3
-TO m ^ rr> CM -3- r-~ o
\ococo r»i m o co co m o
trv oo o
o~> r-. CM -a- -3- UA o ~-\o o
CM r«i r- CM or-- *o IA CM o
vO CO O
ooo o LA LA o o o LA LA LTV
-3- o-\ f\ ro o
OLTVO^ vO-TO-d" O O \OvD O
\O o CM -a- in
CM CM
cr>r~--a- o oo r-\ m r^> e»i en o
v*>or-. CM o i~~ \o voo^-a--a- rr\ o ofo r-s
CM flOO LT> CM CM CM VO
CM c«>
CM cr\ so oo oo -a- m in co \o o
CMv£>r^- vOLTVCM O LA CMOO O
J- OO 0
OOO OOOO O O OO O
LT\OO o~\ rv.oo\r> o vo oo j- o
i r»-i' . r*\ r*\ u"\c*\
CM CM
r^COCMCO 1^ VO vOCT> r-^
<7\ CM CM -3" r-.
(V-\CN1UT\ VOO^LAO CM CTl CT»O O
CM CO -3- -3- CO r~ CM CM O
\D r-~ CM O
ooo oooo o o oo o
vOror^ CMC^-3-lA CT\ -3- LAOO cf\
\£) O r^» LA\D
CM CM
oo-3-m 0^1 r^ o-i r~ -3- r-oo o
-3--3-CM CMUACMCM OO \D CMP^- O
UA OO O
OOO OOOO O O OO O
UAv£>-3- f-^OrA -3" l-~ O -3-
IVIOOO CMt^CMO v£) -3- »^'vl tv>
rv~v \D ' r^
L-
1/10 " "O
4-J _Q Ul C
o) o _Q a) nj
4-j 3 3
i/)
(U-uroo i- -ao_^
tn2u^a>ui (T3 *- c o OJ
_oro CLOJ=(U. 4J _D. l/li- 1-4J 03
l/l"OT3raox:-D3 o
J3Onj(D- OJOt/1 Od)' Ul t/1 t
gU-CDQ-O- 1 3 CZO <
o
0 'Z.
.
"ra
c
re
i_
M«
>^
L-
0
4-»
l_
O
J3
ID
0)
J=
O
4-1
a
1)
L-
3
4-*
V
1_
0)
1_
in
O
a.
re
in
O
Q
1-
U-
(D
4-1
in
3
_a
U
-------
sample (combustibles and noncombustibles) were calculated from laboratory
values by assuming that the noncombustibles contained no moisture, were
completely ash, and contained no heat.
TABLE 4
COMPOSITION OF RESIDUE SAMPLES*
Date of sample
Component
Unburned combustibles
and fines
Metal
Glass
Total
5-
Ib
31
9
23
63
21-68
%
1*3.2
14.3
36.5
100.0
5-22-68
Ib
31.8
10.0
21.0
62.8
%
50.6
15-9
33.5
100.0
5-23-68
Ib
38
9
19
66
%
57.6
13.6
28.8
100.0
Average %
52.5
14.6
32.9
100.0
'Data on a wet basis although the samples were allowed to drain.
TABLE 5
SOLID WASTE, RESIDUE, AND FLY ASH HEAT CONTENTS
Date
5-20-68
5-21-68
5-22-68
5-23-68
Average
Sol i d waste
(Btu/lb, as
received basis)
4,140
4,260
4,550
---
4,320
Residue Fly ash*
(Btu/lb, (Btu/lb
dry basis) dry basis)
___
180
170
250
200 180
"A composite sample was analyzed.
29
-------
TABLE 6
VOLATILE AND ASH CONTENT
(Dry basis)
Material and date tested
Incoming solid waste:
May 20
May 21
May 22
May 23
Average
Res i due :
May 21
May 22
May 23
Average
Volati les
(*)
65. k
69.0
70.3
---
68.2
1.8
1.8
2.3
2.0
Ash
(°A
\'o)
3^.6
31.0
29.8
31 .8
98.2
98.2
97-7
98.0
Fly ash:
May 21-23* 13-9 86.
"One composite sample was analyzed.
The same procedure was used to determine the volatiles and ash in
the total residue sample, because only the unburned combustibles and fines
were returned and analyzed in the laboratory. The percentages of glass
and of rocks and metals were determined in the field, and these two
categories were then discarded. The fly ash sample was returned in its
enti rety.
Liquid Effluents
Laboratory analysis was also performed on the fly ash scrubber water
and the residue quench water (Table 7)- The residue quench water is
recirculated at the rate of 300 gpm, and the fly ash scrubber water is
30
-------
<
z
<
a
o1
,
fl
o
1
4~
O
1
rA
O
l/l O
y) fi3
4) 0
C
1- \
x e
>- rA
4-1 O
LJ
C 03
C_J
03
-^ **v
O")
< E
-j-
0) O
M i/l
03
<4-
^-^
«J
(U J-
4J O
O-
^ ^.
0 g,
a. *-*
CIJ
o . *
1- "\
O Oi
o
-a
OJ 1/1 s-*.
"O "O '"
C \
a) a>
Q. O E
in 1/1
T3
CD (n --
> -o
'o ^ CD
1/1 O E
1/1 in - -
-D
a_
0)
-M
(0
TJ
D
C
l/l Ol
CM .>.>,>
(TJ O3 03 -X X X
LL.
J- O MO O
O O OACO
CM vo cr>
-3- o CM en
-a- CM en
r- co LA r-
-4- J- OO LA
PA CM LT\ O
LA CM CO
-J- ro CO CO
co r*- LA
o CM \o MO
rA ro CM
c
0)
3
^CM^
(U CM Cs| CM
OJ
4-»
M-
(D
C
a)
ro
31
-------
recirculated at 500 gpm. Both systems are drained and flushed at the
end of each week and replenished with fresh water from the city water
supply. The acidic water from the fly ash scrubber is neutralized with
soda ash and is then circulated through a settling basin, where the
entrained fly ash is removed. This water is then pumped to the sump
tank for recirculation. As stated earlier, it was impossible to get a
sample before the soda ash neutralization process. The residue quench
water is recirculated from a separate sump tank with no settlement except
that which takes place in the conveyor tank and in the sump tank itself.
the wastewater from the incinerator is discharged to the city sewer
system for treatment. No additional treatment other than the soda ash
neutralization and sedimentation is performed on the process water before
di scharge.
Cost Analysis
The total annual cost for incinerating 65,000 tons of solid waste
was $^72,082 (Table 8), yielding a unit cost of $7-26 per ton. This
figure includes both operating costs, depreciation, and interest costs.
The operating cost amounted to $^.90 per ton, or 67.5 percent of the
total. Interest and depreciation costs amounted to $2.36 per ton, or
32.5 percent of the total.
The capital cost of the plant was $1,978,7^0, excluding the cost
of land. The depreciation cost was calculated by using a 25-year plant
life and straight-1ine depreciation. The yearly interest was determined
32
-------
TABLE 8
TOTAL ANNUAL COST
1 tern
Annual operating cost:
Direct labor
Uti 1 i ties
Parts and suppl ies
Vehicle operating expenses
External repair charges
Disposal charges
Overhead
Subtotal
Annual financing and
ownership costs:
Plant depreciation
Vehicle depreciation
1 nterest
Subtotal
Total annual cost
Cost
$197,500
20,000
32,950
7,200
6,250
2,000
52,800
318,700
79,1^9
9,675
61*, 558
153,382
i»72,082
Percent of total
ltl.9
k.2
7.0
1.5
1.3
0.1*
11.2
67.5
16.8
2.0
13.7
32.5
100.0
by retiring the bond over the 25~year plant life at an interest rate of
3.2 percent.
The operating costs were analyzed by breaking them into functional
cost centers: receiving, volume reduction, and effluent handling and
treatment (Figure 4). Operations involved in each cost center are also
shown. The cost breakdown by cost center is shown In Table 9-
The total annual cost of repair and maintenance (Table 10) for the
three cost centers was $76,7^7- These repair and maintenance costs (labor,
parts, external charges, and overhead) were allocated to each of the cost
33
-------
UJ
D
9
CO
UJ
co uj tr
UJ |_ 1
s 1 A
§ T
t
O
£
CO
X
m
zzi:
»- t
"Z. Z
UJ UJ
o: 2S
< £ -
so
£S
\
1
_l
- t-
« z z
(K UJ UJ
UJ 2 5
g<^
T-I^ « iii :j ^~t
* £%
Q
5 C
a 5
S 7-
- Li]
I UJ 2
Z z 5
uj o 2
g°s
/i /
,
o
z
o
z
I
z
UJ
u.
u,
UJ
z a:
UJ IU
UJ
o:
l-
UJ
o
o
o
K
-) u]
° 5
I
UJ
o
UJ
or.
i!
UJ <
UJ
o
o:
o
CO
cr
UJ
UJ
o
to
o
o
(D
C
CD
X
0)
Ul
1_
0)
o
o
o
M
(0
0)
c
o
c
(!)
1_
D
cn
'UJ
CO
-------
TABLE 10
BREAKDOWN OF ANNUAL REPAIR AND MAINTENANCE COST
I tern Cost Percent of total
Actual charge:
Labor
Parts
External charges
Overhead
$29,625
32,950
6,250
7,922
38.6
k2.S
8.2
10.3
Total 76,7^7 100.0
Cost center:
Receiving 9,112 11.9
Volume reduction 56,826 7^.0
Effluent handling
and treatment 10,809 1^.1
Total 76,7^7 100.0
of 250 tons. Because the plant was designed to burn 300 tons a day, a
projection was made to estimate what the change in cost would be if the
plant were operated at design capacity (Table 11). Although the total
annual cost would increase from $^72,082 to $^85,762, savings would be
made on a unit cost basis. The greatest savings on a per-ton basis wouid
be in direct labor, since no additional men would be required, and in
financing and ownership costs. The total cost per ton would be reduced
from $7.26 to $6.22.
36
-------
1-
o
s
>. ro
^
O (O
fO C
0. O
ro 4->
o
1 O
o
"3^
0)
"o ro
CTlTJ
C >^
I/I
C C
1- O
3 4->
O
LA
ro CM
3
4-J
U
£
0)
_
c
o
4-1
J_
(U
4-1
(/I
O
o
4-1
(/)
O
o
^_
ro
4-J
o
H-
c
0
4-1
U
0)
4-1
O
O
4-1
U1
0
O
^_
ro
o
i-
CA' OCAI^vO
LACALA OvDCM
CMOOOOOO-3-
oooooooo
OO-3--3-OOOOO
LAO LAvO LA-3-OO CA
I -3"
X i-
4-1 0)0)
l/l l/l .C
O Q) CJ) O
o cm
._ l_ 0)
Dl Q. 4-> O)
c Q- ro ro L.
»- 3 L. Q. ro
4-1 O I/) 0) 0) -C
ro _a a. t- u
i- ro t/i TJ o »
a) d) c "oro
o_ ro Q) ro ro ro 4-*
O4J4J C Ul 0) O
O inOV_OJC4J
r (D^-4->. 1/)Q)3
3 4-to
CQIDQ->LUQO
c
,
o
,
cn
~r
cn
f^»
CM
CM
^J
cn
-a-
cn
r~.
TJ C
c O
ro
4-1
01 4-> ro
C Ul
0 0
O O 0)
C L.
ro o- Q.
c
LA
^~
LA cnvo
en PA
o o CM
LAOO CM
r-~ LAOO
\i) LA PA
O"^ *^f f^\
vO LA
C
0
_
4-1
ro
o
(U
Q.
0)
TJ
4-1 ro
0) l/l 4->
m o
0 »- 4J
(1) -Q
.C 4-1 3
C tO
^ >
CM
CM
M3
CM
vD
LA
00
-T
vO
CM
rC
CM
CO
0
CM
r--
4-1
t/1
0
o
^~
ro
3
C
C
ro
,_-
ro
O
h-
37
-------
REFERENCES
1. American Public Works Association. Municipal refuse disposal.
2d ed. Chicago, Public Administration Service, 1966. p. 375-399.
2. Parr Instrument Company. Operating the adiabatic calorimeter.
J^ Oxygen bomb calorimetry and combustion methods. Technical
Manual No. 130. Moline, 111., I960. p. 30-32.
3. National Center for Air Pollution Control. Specifications for
incinerator testing at Federal facilities. Durham, N.C., U.S.
Department of Health, Education, and Welfare, Oct. 1967- 35 p.
k. American Public Health Association, American Water Works Association,
and Water Pollution Control Federation, Standard methods for the
examination of water and wastewater; including bottom sediments
and sludges. 12th ed. New York, American Public Health Associa-
tion, Inc., 1965. 769 p.
38
-------
ACKNOWLEDGMENTS
The author expresses his appreciation for the excellent cooperation
and assistance extended by the Alexandria Incinerator staff. A special
thank you is extended to Mr. P. B. Hall, Director of Public Works, Mr. Carl
Struder, incinerator superintendent, and Mr. Harry Dodson, incinerator
foreman, whose efforts were essential in planning and conducting the study.
The laboratory assistance provided by the Alexandria Sanitation Authority
in analyzing liquid samples is also greatly appreciated.
The author is also grateful for the aid and support of the staff of the
Bureau of Solid Waste Management. The Division of Research and Development
Operations provided the laboratory support for the study. Members of the
field study team from the Bureau of Solid Waste Management were:
James S. Bridges Tobias A. Hegdahl
Richard A. Carnes Billy P. Helms
Dennis E. Carruth Albert E. O'Connor
Clyde J. Dial Thomas J. Sorg
John J. Giar Charles S. Spooner
Robert Griffin Morris G. Tucker
39
-------
APPENDICES
-------
APPENDIX A
Example Calculations for the Ash, Volatile,
and Heat Content of the Solid Waste
Using the data from the laboratory analyses of the solid waste sample
collected on May 20, 1968, these calculations show the methods used to
calculate the ash, volatile, and heat content of the total sample.
The laboratory analyses (Table A-l) were performed on a dry basis.
The moisture contents shown are inaccurate and it was assumed that the
solid waste contained 20 percent moisture. For the following calculation,
the assumptions were made that the noncombustibles contained no moisture,
no heat, and were considered as "ash."
TABLE A-l
PROXIMATE ANALYSES OF THE COMBUSTIBLE PORTION
OF THE SOLID WASTE SAMPLES
Date sample
col lected
5-20-68
5-21-68
5-22-68
Moi sture
(%)
8.8
18.5
16.8
Volati le
U)
90.2
86.9
93.0
Ash
(*)
9.8
13.1
7.0
Heat
(Btu/lb)
71^5
7090
7530
The moisture content of the combustibles is calculated by the following
method:
-------
rcent moisture /,, . ... . \ / ., \
in total = (lb combust.bles \ f lb moisture \
samole \ lb waste / \1b combust.ble/
bustibleJ
Percent moisture
in tot
sample
20.0 (assumed) = (0.78) [^^i^J^.] 100.0
Ib moisture _ 20.0
lb combustible ~ 100.0 (0.78)
Because the volatile and ash fractions are calculated on a dry basis,
the percent combustibles must be converted to a dry basis by means of the
following equation:
Percent
combus
dry _ Mb wet combustibles - Ib moisture in combustibles] ,nn
tibles \ dry sample wt /
These calculations are summarized in Table A-2.
TABLE A-2
CONVERSION OF THE SEPARATION DATA TO A DRY BASIS
Wet weight Moisture Dry weight
^UIIIpUMfcJM L
Combustibles
iNoncombus ti bles
Total sample
(lb)
205-0
58.0
263.0
U)
78.0
22.0
100.0
(*)
25.6
0.0*
20 . 0*
(lb)
52.5
0.0
52.5
(Ib)
152.5
58.0
210.5
(%)
72. /t
27.6
100.0
kAssumed.
The percent volatiles and ash are calculated by the following method:
Percent volatiles
in total sample
j lb volat i les \ Mb dry combustibles] ,QO Q
\lb dry combustibles/ \ lb dry waste /
Percent volatiles = ( }( ^ } >Q = 6
in total sample
Percent ash in ^ 100>Q _ ent volatiles
total sample
Percent ash in =
total sample
-------
The laboratory reports the heat content on a dry basis for the
combustibles only, thus the moisture content and the noncombustibles in
the total sample must be considered when calculating the heat content of
the total sample. The heat content of the total sample on an "as received
basis" was calculated by the following method:
Heat content
in total
sample
Btu
Ib dry combustibles
1 -1
f% moisture
in total +
sample
noncombustibles
in total samp 1e
100.0
Heat content
in total = 7145
sample
[.
1 -
.O + 22.0
\
;j =
= 7145 (0.58) =
45
-------
-------
APPENDIX B
Example Calculations for the Ash, Volatile,
and Heat Content of the Residue and Fly Ash
Using the data from the laboratory analyses (Table B-l) of the
residue sample taken on May 21, 1968, these example calculations show
the methods used to calculate the moisture, ash, volatile, and heat
content of the total sample. For each sample, only the fines and
unburned combustibles were returned for laboratory analyses. The
laboratory volatile, ash, and heat content data are on a dry basis.
TABLE B-l
PROXIMATE ANALYSES OF THE UNBURNED COMBUSTIBLES AND FINES
Date sample
col lected
5-21-68
5-22-68
5-23-68
Moi sture
(*)
2k. k
20.6
29.9
Volati le
(*)
k.2
k.\
Jt.8
Ash
(*)
95.8
95.9
95.2
Heat
(Btu/lb)
A37
383
513
An additional sample was taken on May 22, 1968 which was analyzed for
moisture only. It contained 2^.5 percent moisture and is the value used
in the efficiency calculations (Appendix C) and was assumed representative
of the residue.
-------
Because the remaining calculations are on a dry basis, the separation
data (Table 4) must be converted to a dry basis by means of the following
equation:
Percent dry _ Mb wet component - lb moisture in wet component j ,_n -
component \ total dry sample wt /
It was assumed that all the moisture was in the fines and unburned
combustibles and that the glass and metals were dry. These calculations
are summarized in Table B-2.
TABLE B-2
CONVERSION OF RESIDUE SEPARATION DATA TO A DRY BASIS
Component
Fines and unburned
combust! bles
Glass and rocks
Metal
Total sample
Wet weight
(Ib)
31
23
9
63
(%)
49.2
36.5
14.3
100.0
Moi sture
(*)
2lt.lt
0.0*
0.0-
12.1
(Ib)
7.6
0.0
0.0
7.6
Dry weight
(Ib)
23. 4
23.0
9.0
55.4
T°/\
'01
1*2.2
41.6
16.2
100.0
-'Assumed.
The percent volatiles and ash are calculated by the following method:
'lb dry fines and
Percent volatiles [ lb volatiles \ I unburned combustibles
in total sample \lb dry fines and ] \ lb dry residue
unburned combustibles,
Percent volatiles = ( ^ (Q ^} ]QQ >Q = ]
in total sample
ioc.;
-------
Percent ash in = ]QQ>Q _ nt vo]atiles
total sample
Percent ash in = 100>Q ,<8 = 98-2
total sample
The heat content is calculated on a dry basis by the following method
(\ /lb dry fines and
Btu I I unburned combustibles
lb dry fines and I I lb dry residue
unburned combustibles/ \
Heat content in = (ll37) (o>422) = ,8o
total sample
The volatile and ash contents of the fly ash as reported by the
laboratory were on a dry basis. Therefore, no adjustment is needed. The
heat content, however, was reported as 1,290 Btu/lb on a moisture and ash
free basis. The following calculation is used to adjust this value to
only a dry basis:
Heat content
total sample
in _| Btu J Mb dry volati les j
e \lb dry volati les/ \ lb dry fly ash /
"9
-------
-------
APPENDIX C
Plant Efficiency Calculations
These calculations show the methods used to calculate the percent
weight reduction, the percent volatile reduction, and the percent heat
released. The following data were used:
Soli d waste
> ,271,8 tons wet
20 percent moisture
; ,017.4 tons dry
6-3,2 percent volatiles
'i,320 Btu/lb
'98.0 hr of burning time
Parti culate
186 Ib/hr
Fly ash
Res i due
31.0 tons wet
69.4 percent moisture
9.5 tons dry
13.9 percent volatiles
180 Btu/lb
399-5 tons wet
24.5 percent moisture
301.6 tons dry
2.0 percent volatiles
200 Btu/lb
51
-------
o
0 0
0 0
1 __ \
1
0)
4->
in -is
TO in
3 -o
14-
O 0
in
4-J
2 i-
- 4J
1- TO
o 3
+
>-
'-
vD -::
in
r-» -o
vO
^
II O
c in
0
. i_
O >- in d>
O S_ d) 4J
T> TO
2
| 1 14- 4-> 0)
LA
cn
CM
CO
4-J
4- 2
>- -C
a- 1/5
T3 TO
+
4->
2
0)
4-1
TO
3
1_
TO
Q.
>>
1_
-o
+
4->
3
0)
3
o
in
d>
i_
>.
i_
o
- O TO 4-i
-3" in
4J O TO
r-~ 3 > 2
0 +
*\
,
_- c
d) ._
4-J 1
in >* in
TO 1-0)
2 i t -o x
in
-O 14- 4-> TO
II O TO
>
O 0 4-1 O
in 3 > LI-
o
14-0 +
o
K
3 ' ~~' o>
LA
>-
L- cn
-o
+
s~*.
CO
cn o
o
o
\O CM
oo
% ^
+
^>
o
r«^
.1 *
4-1
>- in TO
1- 0)
a D
o
14- 4J ._
O TO 4->
I-
4-> O TO
-* 3 > Q-
P--
+
O
a)
>- in 3
i- 0>
O TO «-
4-" O C
2 >
-'": 5
oo
cn
II '
^ *
O 4-J in
c -a
0 0)
O 4-1 1
c a) O
O <- in
. ' TO i-
cn 4J s a)
-3- TO 4->
0) fl 0) M- TO
4-> P-~ cr> x: O 2
in h-D
TO ^ +
2
-a i 4->
- c
. <"
in c
O x:
cn o >^ in
1- TO
O 4-> T3
in TO >
0) 0 a) 14-
0 -C O M-
*
4_t pvH^^^^ ^-
TO
r -K
O x .
> LA
M- cn
o *-*
4-" cn
2 ro
>
L- 0
TD ^^
+
^ ^
\O
1
O
ca
^-^
^
CM
O
O
' '
4-> in
C d)
d) 4-J
4-J TO
C
0 3
^^ O >- O
r=r i-
4-1 -O 4-1
r--. TO i-
d) M- TO
O X O Q
>,
+
, ^
CM 4->
OO C
^0 0)
4-J
0 C
O 0)
0 >- 3
1- T>
4-> -a
TO m
d) <4- d)
_C O 1-
*
'
o
o
0) 0
4-1 .
in
m
2 ^=
u o
o
0
0
in CM
* *
M- *-*
O LA
4-j cn
d) - .
4-> O
c oo
0
(J ~ -
4-- +
TO
d) .
x o
o
o
»*
CM
* '
s~^
vO
i
O
CA
^ ^
^ *
o
o
CM
--
=?
cn
»
co
en
II
- . o
o
o o
0 0
CM
v~"' f^~"~"~*^n~
X s ' *
co co
o
^ 1
r--
CM X
*
D
« ' O O
^"^» t" ~
O 0
CM X
f~> +
cn
-S- co
- o cn
o
*
X
*
CM
d
ii
c
0
4-)
O
3
-a
D
!_
4-J
j:
01
OJ
-3.
4-1
^:
01
- c:
D O
3
4-1
4-J O
C D
a) -a
o a)
1_ !_
0)
Q_
II C
0
4-J
0
3
-o
0)
i_
0)
._.
4J
TO
O
>
1
a>
,
.
-M
OJ
i
o
>
4->
C
TO
0) T3
^ 0)
U)
4-1 TO
C 0)
------- |