SW-36d.iii
REFUSE AS A SUPPLEMENTARY FUEL FOR POWER PLANTS
November 1973 through March 1974
Interim Progress Report
This third interim report (SW-36d.iii) on work performed
under Federal solid waste management demonstration grant No. S-802255
was prepared by G. WAYNE SUTTERFIELD, City of St. Louis
U.S. ENVIRONMENTAL PROTECTION AGENCY
July 1974
-------
-------
TABLE OF CONTENTS
I . Operations Report;
Processing Plant 1
Storage and Outloading Facility 10
Processed Refuse Receiving Facility 11
Refuse Firing Facility 12
II . Economics:
Capital Cost New Equipment 13
Maintenance & Operating Cost City Facilities 15
Maintenance & Operating Cost U.E. Facilities 19
Cost Considerations 20
III. Diagram; PpoaQssa.nrj Facilitj^
23
-------
-------
FOREWORD
The City of St. Louis, Missouri, and the Union Electric
Company, with financial support to the City from the U.S.
Environmental Protection Agency, have been conducting a
demonstration of the use of prepared solid waste as a
supplementary fuel in coal-fired electric utility boilers.
Operations began in April 1972 and continued intermittently
until May 1973, when operations ceased to allow for con-
struction of an air classifier and a metals processing
system. Operations resumed in November 1973.
This report summarizes the operating experience from
November 1973 thru March 1974. It provides a technical
description of the equipment added since May 1973 and
summarizes the operating problems and costs incurred
during that period.
Although the present report is limited in scope, a
general description of the entire system, entitled Energy
Recovery from Waste, is available from EPA's Office of
Solid Waste Management Programs. In addition, the results
of the air pollution tests mentioned on page 12 will be
published by EPA later this summer.
All of these reports are part of our effort to provide
information about as many resource recovery options as
possible.
ARSEN J. DARNAY
Deputy Assistant Administrator
for Solid Waste Management
-------
-------
I. PROJECT OPERATIONS
A. Processing Plant
In November 1973, after installation of the new air density
separator equipment, the processing plant was returned to service.
Shake down of the new equipment was conducted from 9 to 23 November
1973- The new equipment proved to be functional, however, cer-
tain modifications were determined to be necessary to permit an
acceptable level of plant operation. Minor modifications to the
equipment were made to permit plant operations to proceed while
more extensive modifications were scheduled for late April 1974.
The processing plant has operated at considerably less than
optimum capacity since returning to service in November. The
principal factors contributing to the reduced operation include;
1. Excessive downtime for repairs at the firing facility
operated by Union Electric»
2. Severe weather conditions which curtailed collection
of refuse for several days during December 1973 and January 1974.
3. "Work stoppages by city refuse collection crews.
4. Additional maintenance and operating problems caused by
failure of newly installed equipment to operate as anticipated.
5. Loss of 13 potential operating days due to repairs
necessitated by damage resulting from a fire which occurred on
February 28, 1974.
6. Reduced capacity of the firing facility to consume
processed refuse due to:
-------
a. Two rather than three shift burning operations.
b. Inability of U.E. to maintain firing on all four
refuse burners in any consistent manner due to excessive pipe
wear. Only two to three burners are normally in service at any
given time. The reduced capacity of the firing facility has
subsequently reduced the necessary operating time of the proces-
sing facility that is required to provide sufficient quanities
of processed refuse.
PLANT OPERATING TIME (AFTER SHAKE DOWN)
NOVEMBER 73 thru MARCH 74
Possible Operating Actual Operating
Time @ 7 hrs/day Time During
Optimum Period
616 hours 264 hours
Lost Time Lost Time Non-Operation
Assigned to Assigned to Due To Reduced
UE Operations City Operations Firing System Capacity
f
84 hours 133 hours* 135 Hours
*91 hours lost time to City operation caused by repair
of fire damage
Report on Equipment:
The following discussion is related only to equipment
which has had some noteworthy developments since the writing of
the previous interim progress report for the period April 1972
to February 1973•
-------
Raw Refuse Receiving Belt Conveyor
The raw refuse receiving conveyor was installed in May 1973»
by T.E.C.O. Inc. St. Louis, Mo. The conveyor has a 96" wide belt
24*0" in length, and an infinitely variable belt speed between
zero and 54* per minute.
t
The purpose of the conveyor is to provide a means of
metering raw refuse to the shredder at a rate which will result
in providing optimum refuse processing.
In addition, the conveyor enables a visual inspection of
the incoming refuse by the control room operator. This visual
inspection capability enables the operator to detect and remove
heavy metal objects from the refuse which may be of potential
damage to the shredder. The belt conveyor was installed as a
replacement to a vibrating conveyor which was not functionally
compatible with the processing building, (see previous interim
report.)
The general performance of the conveyor to date has been
very unsatisfactory. Problems which have been encountered with
the conveyor are as follows.
1
1. The S.E.C.O. SCR drive motor and motor control package
has not functioned well since the beginning of operation in
November 1973* The electrical control package has blown fuses
and diodes. Corrective measures taken to resolve the circuitry
problem has involved numberous visits to the processing plant
by the conveyor supplier, two visits by the equipment manufacturer's
representative, returning the entire control package to the
assembly plant for re-work, and several days work on the system
3''
-------
by local electricians and electrical engineers. In addition to
the work done on the electrical system, gears have been changed
in the motor drive train to increase the ratio from 1:75 to 1:125
and subsequently increase the output torque available to the
drive sprocket of the conveyor belt.
At this point in time the conveyor is performing considerably
better, however, there is still an occasional stoppage due to
overload. In an attempt to resolve the occasional overload
problem, a new drive sprocket has been placed on order. The
new sprocket will provide approximately 50$ more torque delivery
to the head pully drive shaft,
2. The conveyor belt will drift from one side to the other
depending on the direction of belt loading. There is apparently
no amount of adjustment that can be made to resolve this tracking
problem. The belt tends to move away from the side that material
loading is occurring on. This presents an operational problem
in that loading of the belt must be accomplished by alternating
material loading from one side then the other in order to com-
pensate for lateral belt movement.
Air Density Separator (ADS)
The newly installed (ADS) system was provided by Rader
Pneumatics Inc. of Memphis Term. The system consists of seven
basic items of equipment. Unless differently indicated, all
equipment items are products of Rader Pneumatics Co.
1. Metering Surge Bin
The metering surge bin has a capacity of approximately
-------
6.5 cubic yards. The north and south walls of the bin are straight
while the east and west walls are inclined forming a "V" shape
where they join together at the bottom. The west inclined wall
of the bin is live having a chain driven flight conveyor traveling
up its face. The east bin wall is a dead wall.
The intended function of the surge bin is to accept discharge
variations from the raw refuse shredder, and provide a uniform
rate of material feed to the vibrating conveyor feeding the inlet
air lock feeder to the A.D.S. separation zone.
The major problems encountered with the surge bin are:
a. Material bridging in the bin in spite of the fact that
one wall is live and equipped with a moving flight conveyor.
b. Excessive wear has occurred on the rails carrying the
flight conveyor chain. After approximately 2#0 hours of operation
the chain rail required replacement.
c. Excessive carry-over of milled refuse by the flight conveyor
has created a housekeeping problem. The material tends to accum-
ulate in the lower return side of the conveyor housing and requires
cleaning weekly.
In an effort to resolve the operational problems encountered
with the surge bin, Rader Pneumatics has proposed the following
modifications:
a. Install ultra high density plastic liners in the surge
bin to overcome bridging.
b. Install seals and rearrange the flight conveyor sprocket
carriers to overcome the housekeeping problems.
-------
c. Install wear resistant alloyed steel on the chain carriers
to reduce the wear problem.
The work to accomplish these modifications is scheduled for
late April 1974.
2. Vibrating Conveyor
The vibrating conveyor is a product of F.M.C./Link Belt,
Chicago, 111. The conveyor is an £' wide 10' long excentric type
machine with a 3/#" straight line stroke.
The vibrating conveyor transfers milled refuse from the surge
bin to the infeed air lock to the ADS separation zone.
The conveyor has presented one minor problem since beginning
operations. The conveyor was unable to convey material at a high
enough rate initially to accomodate the output rate of the shredder,
The problem was overcome by increasing the slope of the conveyor
several inches which subsequently increased the linear velocity
of the material being conveyed.
3. Infeed air lock feeder
The air lock feeder is a typical rotary type machine, £' 2"
long and 2* 9" in diameter. The feeder is driven by a 15 HP, l£00
RPM TEFC, 3 phase, 60 cycle, 460 V motor through a Falk 2407 T25
shaft mount 76:1 reducer. The air lock feeder serves to transfer
shredded refuse from the vibrating conveyor into the air separation
zone of the ADS.
During the first several weeks of operation, the air lock
feeder would plug-up with refuse periodically. The plugging
-------
problem was resolved by cutting out a portion of the rotor center
plates on which the refuse tended to bridge and accumulate. No
problems have been experienced with the feeder since the minor
rotor modification was accomplished.
4. Air Separation Zone
The air separation zone is a rectangular open ended steel box
31 9" wide (maximum) x 7' 10-1/2" long x 51 6" deep. The two long
walls (5f 6" x 7* 10-1/2") have four hinged segments which may be
adjusted in and out to vary the 3' 9" dimension of the zone. Milled
refuse is introduced at the top of the steel box and to one side
across the long dimension. The adjustable side walls may be moved
in and out to provide separation zone configurations which will
yeild optimum separation of material consistent with given air
velocities. As the refuse enters the separation zone it tumbles
down and encounters turbulent air flow. The quantity of air may be
adjusted to obtain the desired level of separation within the limits
of the separators capability.
Operating experience thus far has indicated that approximately
14 to I6f<> by weight of the shredded refuse tends to drop as heavy
fraction in this separation process. Tests are currently underway
to establish the optimum separation capability of the separator.
-'• /^
The optimum separation capability siiail be determined for the sys-
tem by systematically changing the configuration of the separation
zone and establishing the quantity of air flow which will give the
best results.
-------
5» Cyclone Separator and Transfer Pipe
The cyclone separator is 36* 6" high and 14' in diameter at
the widest point. The cyclone serves to separate the refuse from
the conveying air and returns the refuse fuel fraction to a con-
veyor leading to the storage bin.
The cyclone separator and connecting conveying pipe has func-
tioned reasonably well and there appears to be little evidence of
internal wear due to abrasion to date. One major problem with the
cyclone separator is the amount of carry over of particulate matter
that is exhausted with the conveying air to the atmosphere. At
the present time the exhaust from the cyclone separator is quite
unacceptable due to the carry over problem,
A reverse flow trap was installed initially, down stream from
the cyclone to attempt to minimize the carry over problem, however,
this proved unfeasible due to severe plugging problems on the trap
screens.
The screens were removed from the reverse flow trap to permit
temporary operation with high particulate emissions.
Rader Pneumatics Co. has proposed installation of a cylin-
drical baffle plate in the center of the cyclone beneath the dis-
charge tube. The purpose of the baffle plate would be to break-up
the inner vortex as it exits the cyclone thereby reducing the
tangential velocity and subsequently the ability of the discharge
air to carry out particulate matter. This modification will be
; , ' I f
dene in late April 1974*
-------
If the discharge air is still considered to be too heavy with
particulate matter to be exhausted to the atmosphere, other measures
will have to be employed to resolve the problem.
6. A.D.S. Fan
The fan which provides the air for the A.D.S. system is a size
44, type PLR HDI. The fan is rated at 4^,000 CFM at 13.5" SP, 70° F,
1443 RPM and 134 BHP. The fan is a product of the New York Blower
Co. Chicago, 111.
Operation of the fan to date has been satisfactory. Several
minor problems require attention to improve the fan's performance.
The inlet vanes to the fan require cleaning on a daily basis. Re-
moval of the particulate matter from the air up stream from the fan
would resolve this problem. The pneumatic controller which governs
the quantity of air flow through inlet vanes to the fan, is sluggish
and reacts rather slowly. Rader Pneumatics has proposed increasing
the fan's rpm to improve the responsiveness of the controller.
This change can be accomplished by altering the fan pulley drive
ratios. This modification is presently scheduled to be done in
May 1974.
7. Discharge Air Lock Feeder
The discharge air lock feeder, a Rader model 60 x 60, has a
rotor housing 4' 11" long with a 4' 10" diameter. The feeder is
driven by a 25 HP, 1800 RPM TEFC motor through a Falk model 2415J25
reducer. The feeder maintains an air seal at the discharge point
of the cyclone separator while passing shredded refuse to a conveyor
-------
belt leading to the storage bin.
The discharge air lock feeder has functioned well in all
respects since the beginning of operations.
In general the entire A.D.,3. system has functioned reasonably
well considering the relative newness of the idea of air classify-
ing shredded solid wastes. There is a considerable amount of test-
ing and evaluation which is required to improve on the operation of
the present system. At this point in time it is difficult to say
if the present A.D.S. system will provide the desired level of
separation efficiency. In any event, air separation of processed
refuse can be done successfully. It does improve material handling
characteristics and it opens a new avenue of approach to further
recycling of solid waste.
B. Storage and Outloading Facility
Storage Bin
At the writing of the last report, it was indicated that the
storage bin walls had a tendency to bulge when the bin was filled.
The Miller Hofft Company, manufacturers of the bin, attempted to
correct the problem of the bulging walls by installing two tension
rods on the inside of the bin. The tension rods were intended to
tie the bulging walls together and overcome the outward force. Upon
filling the bin after installing the rods, it was noted that the
rods had been bent downward due to the overhead weight of the refuse,
The result was that the bin walls were drawn inward and this inter-
fered with the unloading process. The rods had to be removed and
Miller Hofft has now determined that they must reinforce the weak
10
-------
wall from the outside. The work to reinforce the wall is scheduled
to be done by Miller Hofft in May or June 1974.
Storage Bin Unloading System
The processed refuse is removed from the storage bin by means
of a traversing, twin screw unloader. The previous interim report
indicated that a torque problem existed with the 150 HP drive motor
on the bin unloader. The original drive motor was unable to develop
sufficient starting torque to turn the screw unloader under normal
load. A new motor was installed in April of 1973* The new motor
provides approximately 300$ more starting torque than the original
motor. Installation of the new motor appears to have resolved the
starting problem.
C. Processed Refuse Receiving Facility
There has only been one item of equipment modified at the
receiving facility since the previous interim report. The original
pneumatic transfer line which conveyed material from the receiving
facility to U.E.'s storage facility was a 12" diameter round pipe.
The 90 degree pipe elbow, which was located at the discharge open-
ing of the air lock feeder, has been removed and replaced with a
flatback elbow having a replaceable wear plate. The replaceable
wear plate is placed in the impact zone of the 90 degree turn. It
is thought that the replaceable wear plate feature will reduce
maintenance problems associated with pipe wear due to abrasion.
The elbow has been functioning very well since installation.
11
-------
Refuse Firing Facility
The basic operation of the refuse firing facility has not
changed since the previous interim report. Union Electric replaced
the worn turns in their pneumatic transfer system and has had the
housing of their air lock feeders equipped with replaceable stainless
steel liner plates to improve feeder wear. The rework of their
pneumatic system was done during the same period as the installation
of the A.D.S. system at the processing plant.
The Union Electric Co. has indicated that air classification
of processed refuse has improved the firing operations. Prior to
air classification of the refuse the air lock feeders in the firing
facilities experienced frequent jamming. The air classifier has
essentially eliminated the feeder jamming. Though the pipe wear
problem has been somewhat reduced, there is still a considerable
amount of pipe wear occurring. The pipe wear occurs primarily at
the piping bends and elbows with little wear occurring in the
straight pipe sections. Union Electric has indicated that they
do not consider the pipe wear to be a serious problem. It is recog-
nized, however, that special wear resistant elbows and bends will
be necessary in the pneumatic trano/ort system.
Union Electric and the U.S. E.P.A. conducted precipitator and
gas emmission tests in late November and early December 1973* The
preliminary results of the tests did not disclose any apparent
serious pollution problems. It has been generally concluded that
additional air testing will be done to confirm the first test data
prior to release of any detailed information on the subject.
12
-------
CAPITAL EXPENDITURES
Capital expenditures which have occurred in addition to those
reported in the previous interim report for the period of April 1972
to February 1973 are:
Processing Plant
Equipment:
Air Density Separator System $ 114,934
Metal Densification Unit 30,430
Belt Conveyors 19,271
Air Compressor, Vent Fan and Motor 1,391
Perment Magnet Drum 2 f620
Sub Total $ -169,146
Construction:
Excavation and Grading $ 4,660
Concrete Id,791
Structural Steel • 83,360
Asphalt Concrete 4,169
Installation of Equipment 97,353
Electrical 65,393
Painting 7,372
Sub Total $ 237,103
Engineering (ADS System) 53,000
Total Additional Capital
Processing Plant $ 514,249
Rolling Stock
Tandem Metal Haul Dump 10,557
Pick-up Truck 2,403
75 Cubic Yard Transport Trailer 17,197
Total Rolling Stock $ 30,157
13
-------
Miscellaneous .Equipment
Office 160
Testing 2,#22
Communication 2,#71
Shop 1,269
Total Miscellaneous Equipment 7,122
Total Additional Capital Cost
of Project May 73 - March 74 $ 551,523
Capital Cost of System Prior To Installation of A.D.S.
Processing Plant 1,226,933
Receiving Facility 367,543
Firing Facility 573,097
Rolling Stock 121,029
Miscellaneous Equipment 4^054
*Total $ 2,297,711
Capital Cost of System to Date:
Processing Plant 1,741,237
Receiving Facility 367,543
Firing Facility 573,097
Rolling Stock 151,136
Miscellaneous Equipment 11,176
Total (excluding amortisation) $2,349,239
*See Interim Report for period April 1972 to February 1973
Itemized breakdown.
14
-------
OPERATING AND MAINTENANCE COST
CITY OPERATED FACILITIES
November 73 to April 74
MAINTENANCE AND FUEL COST CITY OPERATED EQUIPMENT ITEMS
Raw Refuse Receiving and Processing Facilities
Shredding Equipment
Raw Refuse Receiving Conveyor
Raw Refuse Belt Conveyor
Raw Refuse Vibrating Conveyor
Haramerrnill (retipping)
(other;
Processed Refuse Vibrating Conveyor
Processed Refuse Belt Conveyor
Shuttle Belt Conveyor
Total Shredding Equipment
Air Density Separation Equipment
Surge Bin Drag Conveyor
Vibrating Pan Conveyor
Infeed Air lock Feeder
Pneumatic Pipe
Cyclone Separator
Separation Zone
Discharge Airlock Feeder
Conveying Fan
Heavy Fraction Belt
Total Classification Equipment
Ferrous Metal Recovery Equipment
Magnetic Belt Separator
Nuggetizer
Magnetic Drum Separator
Ferrous Recovery Belt
Total Ferrous Metal Recovery
Parts/
Supplies
57.01
7.29
1.23
2,241.62
580.16
235.72
266.06
30.15
3,419.24
Parts/
Supplies
262.02
113.94
19.62
36.61
45.50
100.03
702. 33
Parts/
Supplies
9.04
559.15
30.69
6.55
Maint .
Labor
77.46
9.92
1.69
2,724.20
783.32
320.35
140.13
41.25
4,103.32
Maint .
Labor
355.85
161.59
26.67
117.72
61.37
136.06
955.31
Maint .
Labor
12o30
753.34
41.33
3.92
*Cost/ton
.01
.53
.15
.06
.04
.01
.30
* Cost/ton
.07
.03
.02
.01
.13
**Cost/ton
.07
4.03
.22
605.43
321.44
4.37
15
-------
Storage and _0utloadirig Facility
Equipment
Traversing Bin Unloader
Bin Reclaim Conveyor
Packer Belt Conveyor
Packer
Total Storage and
Outloading Equipment
Parts/
Supplies
115.39
72.36
1.24
23.35
212.34
Maint,
Labor
156.96
9S.2?
1.69
31.73
233.65
Cost/ton
*** .04
• 03
.01
.03
City Receiving Facilities at Power Plant
Equipment
Traversing Bin Unloader
Bin Reclaim Conveyor
Pneumatic Feeder
Blower
Pneumatic Transfer Pipe
Total City Receiving
Facility Equipment
Parts/
Supplies
162.27
41.66
feint.
Labor
220.37
56.36
***
Cost/ton
.06
.01
203.93
277.23
.07
Equipment
Tractor Trailer 52 Body
Chassis
Fuel
Tractor Trailer 53 Body
Chassis
Fuel
Total Tractor Trailers
ROLLING STOCK
P/Supplies
67.01
671.61
14.79
621.41
1,374.32
M/Labor ***Cost/ton
33.75
7.50
120.75
217.00
.02
.10
.02
.10
.24
Front end loader 50
Front end loader 51
fuel 50
fuel for 51
Total Front End Loaders
6.99
35.31
123.44
122.32
233.56
40.00
272.00
314.00
Cost/ton
.01
.03
.01
.01
.06
16
-------
)ther Vehicles
.3 cu. yd. Dump Truck Maint.
Fuel
3ick-up Truck Maint
Fuel
^reject Sedan Maint
Fuel
?otal Rolling Stock
iain.t and Fuel Cost
Parts/
Supplies
$ 64.23
149.30
55.92
30.05
37.70
Ma int.
Labor
$ 146.00
6.00
34.60
Total
$ 210.23
149. SO
6.00
55.92
64.65
87.70
$2,051.08
$ 717.60 $2,768068
*Eased on 9,393.31 Tons Processed
**Eased on 326.27 Tons Recovered
***Based on 6,641.62 Tons Delivered
MATERIAL SUMMARY
November 73-March 74
4onth
Raw Refuse
Delivered to Plant
Processed Refuse
Delivered to Electric Plant
Metal Delivered
To Granite City S.
vember
:ember
luary
Druary
rch
Lds
203
379
386
490
234
Tons
1,244.73
2,125.65
2,142.24
2,690.57
1,190.12
Lds
46
77
85
94
-21
Tons
928.71
1,395.96
1,693-65
1,969.21
654.09
Lds
4
1
13
12
7
Tons
31o99
9.36
113.61
107.03
64.28
1,692 9,393.31
333
6,641.62
37
326.27
17
-------
COST SUMMARY
CITY OPERATED FACILITIES
Maintenance and Fuel Cost
Facilities and
Rolling Stock
Receiving & Processing
Storage & Outloading
Receiving (Power Plant)
Rolling Stock
Total
Parts &
Supplies
4,727.55
212.34
203.93
2,051.08
Maint.
Labor
5,880.07
288.65
277.23
314.00
Total
10,607.62
500.99
481.16
2,365.08
7,194.90
6,759.95
13,954.85
Cost Catagory
Maintenance Labor
Operating Personnel
Supervisory Personnel
Office Supplies
Parts and Supplies
Electrical Power (264,000 KWH)
Total Normal Operating
and Maintenance cost
$ 6,759.95
29,599.68
7,050.28
82.60
7,194.90
2.230.86
$52,918.2?
Refuse Processed November 73 - March 74
Operating and Maintenance Cost
9,393.31 tons
5.63/ton
Note: The following amounts were removed from the total cost
in order to arrive at the normal operating and maintenance
figures.
Cost of Fire Damage Repairs
Cost of Experimental Grate Bars
$ 8,025.05
5,509oOO
18
-------
OPERATING AND MAINTENANCE COST
UNION ELECTRIC OPERATED FACILITIES
NOVEMBER 73 to APRIL 74
The following cost data has been extracted from Union
Electric*s monthly print-out, which reflects categorical costs
as indicated. There is no break down in cost as related to
individual items of equipment.
Operating Cost
Operating Personnel Cost 3,200.00
Maintenance Personnel Cost 25,926.00
Supervision Cost 2,010.00
Parts and Supplies 8,077.23
Total Operating and
Maintenance Cost for Period $ 44,213.23
Tons Processed refuse delivered
to Union Electric for Period 6,642
Operating and Maintenance Cost Per Ton $6.66
Cost Incurred by UE Not Relevant to Facility Operations
Refuse Testing $ 4,967.00
Miscellaneous Testing 10,506.20
Engineering a,415.17
Travel & Miscellaneous Changes 167.25
Total $ 24,055.65
19
-------
COST CONSIDERATIONS
City Operated Facilities
The cost shown on the cost summary sheet reflect the normal
operating and maintenance cost for the period November 1973 thru
March 1974. During this period the operating personnel costs were
excessive due to large amounts of lost operating time. The pro-
cessing plant was operated only 42$ of the normally available
operating time. City operations were responsible for 3&fo of the
total lost time, with U.E. operations accounting for the resto
Of the lost time assigned to city operations, &9$ was uncon-
trollable being caused by severe weather conditions, employee work
stoppages, and repairs caused by fire damage. The lost time, charg-
able to normal city operations amounts to approximately 5$ of the
total.
If the operating personnel cost is adjusted to reflect only
the normal lost operating time of the city operated facilities,
the cost of processing and delivery drops from $5.63/ton to $3«90/
ton.
The ferrous metal being recovered at the processing plant is
valued at $20.00 per long ton. If the value of the recovered
ferrous metal is taken into consideration, the processing and deliv-
ery cost amounts to $3«40/ton.
Union Electric Facilities
U.E. operating and maintenance cost for the period covered
20
-------
in this report has been $6.66 per ton of refuse fired into their
boiler.
Approximately 11% of this cost is concentrated in the mainten-
ance area. The principal cause of the high maintenance expenditure
is still attributed to repairs due to adrasion in the transfer
pipes. U.E. does not express particular alarm at the high cost
of the pipe wear problem contending that the matter of abrasion
can be brought under control with special wear resistant pipe turns
and elbows. At the present time, however, the transfer pipes are,
for the most part, mild steel piping, little different from the
original installation.
The main problem with the high maintenance requirements of
the firing facility is the excessive amount of lost operating
time.
Lost time due to maintenance of the firing facility has
accounted for 62fo of the total lost operating time for the project
systems during the period of this report.
U.E. has indicated that it is their intent to maintain and
provide for the necessary modifications to the firing facility
that are necessary to accomplish optimum reliability and efficiency
of operation. There has, however, been no definitely established
direction or concrete commitment on the part of U.E. to resolve
the firing facility problems.
In light of the above discussion it is apparent that the lost
time problems encountered at the firing facility must be resolved
before meaningful long term operating data can be obtained.
21
-------
Amortization
The subject of amortization cost cannot be properly addressed
until the useful life and optimum capacity of the various systems
have been established with some degree of reliability. Therefore
discussion of amortization cost will be defered until such infor-
mation becomes available. v
22
-------
DIAGRAMS
a. Processing Facilities
b. Receiving Facilities
r, F-irfn TVi-ili'-i •-
-------
Refuse Collection Truck
Belt Scale
Surge Bin
Hammermill
Conveyors
Nuggetizer
Magnetic Separator-
4 ^- Conveyor
^-Magnetic Metals Truck
Feeders
Air Density Separator
Magnetic Separator
Heavy Fraction
Conveyor
L
Non —Magnetic Residue-^
Fan
Light Fraction Storage Bin
Conveyor
Cyclone Separator
Belt Scale
'— Stationary Packer
Self—Unloading Truck
SOLID WASTE
PROCESSING FACILiT
-------
ry
c.-r» S tract
-------
------- |