Page 235 - Air Pollution Control Engineering

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214 Lawrence K. Wang et al.

Table 6
Capital Costs Factors for Absorbers
Cost Item Factor
Direct Costs (DC)
Purchased equipment cost
Absorber (tower & packing) + auxillary equipment As estimated, EC
Instrumentation 0.10 EC
Sales tax 0.03 EC
Freight 0.05 EC
Purchased Equipment Cost (PEC) 1 PEC = 1.18 EC
Direct Installation Costs
Foundation and supports 0.12 PEC
Erection and handling 0.40 PEC
Electrical 0.01 PEC
Piping 0.30 PEC
Insulation 0.01 PEC
Painting 0.01 PEC
Direct Installation Cost 0.85 PEC
Site preparation As required. SP
Building As required, Bldg.
Total Direct Costs 1.85 PEC + SP + Bldg.
Indirect Costs (IC)
Engineering 0.10 PEC
Construction 0.10 PEC
Contractor fee 0.10PEC
Start–up 0.01 PEC
Performance test 0.01 PEC
Contingencies 0.03 PEC
Total Indirect Cost 0.35 PEC
Total Capital Costs 2.20 PEC + SP + Bldg.
Source: ref. 9.

scrubber tower treating 50,000 scfm with a pressure loss of 5 in. of H O, the fan is pulling
2
approx 46 hp. This horsepower is costing the plant over $37,000 per year. Therefore, if
a 50% reduction in pressure drop in the tower could be realized, the plant would net a
power savings of over $18,000 per year.
Another consideration in scrubber tower operating cost is the cost of scrubbing liquor
(absorbent), usually water that is consumed in normal operation of the tower. The annual
solvent required (ASR) is expressed by
ASR = 60 (L ) HRS (26)
gal
Table 6 presents capital cost factors for several absorbents (9). The annual solvent cost
(ASC) may now be calculated by multiplication of ASR by the unit solvent cost (USC):
ASC = (USC) (ASR) (27)