Application of
Computerized Analysis to Comparative
Costs of Sludge Dewatering by
Vacuum Filter and Centrifuge
THOMAS P. QUIRK, Parmer
Quirk, Lawler, and Matusky Engineers
505 Fifth Avenue
New York, New York
DEWATERING SYSTEM AND ANALYTICAL APPROACH
Dewatering operations follow sludge concentration and precede final disposal
of dewatered cake. The degree of solids concentration achieved prior to dewatering will control dewatering performances for a given sludge. Similarly, the final
disposal operation will exert a major influence on the definition of dewatered
sludge. The analyses used in this paper recognize the intermediate nature of the
dewatering operation and provide for acceptance of the various limitations and
controls imposed by upstream pretreatment and downstream final disposal.
For broad appeal, cost and performance data require generalization. However, generalization without recognition of specific process limitations can lead
to misleading information. Similarly, cost and performance information for
specific process conditions, while of local interest, cannot supply enough relationships for broad, general appeal. The use of the system analysis approach
allows for both generalization and specificity needs to be served.
The system analysis procedure employed (Table I) involves the following
steps: 1) Development of performance model for the unit operation and/or the
equipment under study; 2) Use of field performance data to define the constants in
the performance model; 3) Development of a cost model for the unit operation
and/or equipment under study; 4) Relation of cost and performance parameters so
that cost effects of changes in performance requirements can be determined for
each component of total cost; and 5) Use of computer facilities to execute the
cost of performance relationships for any condition desired.
TABLE I
CENTRIFUGE VERSUS VACUUM FILTER SYSTEMS ANALYSIS APPROACH
Develop Models for Equipment Performance
Determine Performance Constants from Field Data
Develop Models for Capital and Operating Costs
Determine Cost Constants from Bids, Take-Offs and Analysis of Operation
Program Performance and Cost Models for Computer Solution
Compare Centrifuge and Vacuum Filter Costs
- In General
- For Specific Installation
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