appC Process Engineering Economics - James R. Couper

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Unformatted text preview: APPENDIX C Equipment Cost-Capacity Algorithms1 The choice of appropriate equipment often is influenced by considerations of price. A lower efficiency or a shorter life may be compensated for by a lower price. Funds may be low at the time of purchase and expected to be more abundant later, or the economic life of the process is expected to be limited. Alternative kinds of equipment for the same service may need to be considered: water-cooled exchangers vs. air coolers, concrete cooling towers vs. redwood, filters vs. centrifuges, pneumatic conveyors vs. screw or bucket elevators, and so on. In this chapter, the prices of classes of the most frequently used equipment are collected in the form of correlating equations. The prices are given in terms of appropriate key characteristics of the equipment, such as sqft, gpm, lb/hr, etc. Factors for materials of construction and performance characteristics other than the basic ones also are provided. Although graphs are easily read and can bring out clearly desirable comparisons between related types of equipment, algebraic representation has been adopted here. Equations are capable of consistent 1 The cost-capacity algorithms were obtained from Stanley M. Walas' book, Chemical Process Equipment: Selection and Design (Woburn, MA: Butterworth, 1988). Permission was obtained to reproduce the material. Butterworth is now part of Elsevier Science and Technical Publications. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 392 Appendix C Example 1 Installed Cost of a Distillation Tower Shell and trays are made of AISI 304 stainless steel. Dimensional data are: D 4 ft, L 120 ft, N 58 sieve trays, wall thickness tp 0.50 in. for pressure, tb 0.75 in. at the bottom, flanged and dished heads weigh 325 lb each, weight W (p/4)(16)(120(0.5/12)(501) 2(325) 32,129 lb Cb 1.218 exp[7.123 0.1478(10.38) 0.02488(10.38)2 0.158(120/4) ln (0.75/0.50)] 697,532, f1 1.7, f2 1.189 0.0577(4) 1.420, f3 0.85, f4 1, Ct 457.7 exp[0.1739(4)] 917.6, Cp1 249.1(4)0.6332(120)0.8016 27,867, purchase price C 1.7(697,532) 58(1.42)(0.85)(917.6) 27,867 $1,266,414 From Table 3, the installation factor is 2.1 so that the installed price is Cinstalled 2.1(1,266,414) $2,659,467. A tower packed with 2 in. pall rings instead of trays: packing volume Vp (p/4)(4)2(120) 1508 cuft, Cinstalled 2.1[1.7(697,532) 1508(28.0) 27,867] $2,637,380. reading, particularly in comparison with interpolation on logarithmic scales, and are amenable to incorporation in computer programs. Unless otherwise indicated, the unit price is $1000, $K. Except where indicated, notably for fired heaters, refrigeration systems, and cooling towers TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 393 Example 2 Purchased and Installed Prices of Some Equipment a. A box type fired heater with CrMo tubes for pyrolysis at 1500 psig with a duty of 40 million Btu/hr. From Item No. 10 (Table 1), the installed price is Cinstalled (6218) 33.8(1.0 0.10 0.15)(40)0.86 1,228,134 b. A 225 HP reciprocating compressor with motor drive and belt drive coupling. Items Nos. 2 and 13 (Table 1). The installation factor is 1.3. Compressor C 7190(225)0.61 197,572, motor,1800 rpm,TEFC, C 1.46 exp[4.5347 0.57065(5.42) 0.04069(5.42)2] $11,858 belt drive coupling, C 1.46 exp[3.689 0.8917(5.42)] $8,772, total installed cost, Ctotal 1.3(197,572 11,858 8772) $283,663. c. A two-stage steam ejector with one surface condenser to handle 200 lb/hr of air at 25 Torr, in carbon steel construction. From Table 3 the installation factor is 1.7. X 200/25 8, f1 1.6, f2 1.8, f3 1.0 purchase Cp 13.3(1.6)(1.8(1.0)(8))0.41 $90,510, installed C 1.7Cp $153,866. (which are installed prices), the prices are purchase prices, FOB, with delivery charges extra. In the United States delivery charges are of the order of 5% of the purchase price, but, of course, dependent on the unit value, as cost per lb or per cuft. Multipliers have been developed whereby the installed cost of various kinds of equipment may be found. Such multipliers range from 1.2 to 3.0, but details are shown in Table 1. Data are taken from Walas and were updated to the end of fourth quarter 2002, a selection of which is in Table 2. The equipment prices have been spot checked with vendors. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 394 Appendix C Index of Equipment Falling film Fired heaters Box types Cylindrical types Heat exchangers Shell-and-tube Double pipe Air coolers Mechanical separators Centrifuges Cyclone separators Heavy duty Standard duty Multiclone Disk separators Filters Rotary vacuum belt discharge Rotary vacuum scraper discharge Rotary vacuum disk Horizontal vacuum belt Pressure leaf Plate-and-frame Vibrating screens Motors and couplings Motors Belt drive coupling Chain drive coupling Variable speed drive coupling Pumps Centrifugal Vertical mixed flow Vertical axial flow Gear pumps Reciprocating pumps Refrigeration Steam ejectors and vacuum pumps Ejectors Vacuum pumps Vessels Horizontal pressure vessels Vertical pressure vessels Storage tanks, shop fabricated Storage tanks, field erected TABLE 1 1. 2. 3. 4. 5. 6. 7. 8. 9. Agitators Compressors, turbines, fans Centrifugal compressors Reciprocating compressors Screw compressors Turbines Pressure discharge Vacuum discharge Fans Conveyors Troughed belt Flat belt Screw, steel Screw, stainless Bucket elevator Pneumatic Cooling towers Concrete Wooden Crushers and grinders Cone crusher Gyratory crusher Jaw crusher Hammer mill Ball mill Pulverizer Crystallizers External forced circulation Internal draft tube Batch vacuum Distillation and absorption towers Distillation tray towers Absorption tray towers Packed towers Dryers Rotary, combustion gas heated Rotary, hot air heated Rotary, steam tube heated Cabinet dryers Spray dryers Multiple hearth furnace Evaporators Forced circulation Long tube 10. 11. 12. 13. 14. 15. 16. 17. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 395 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 396 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 397 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 398 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 399 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 400 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 401 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 402 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 403 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 404 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 405 TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 406 Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms 407 Material of construction is a major factor in the price of equipment so that multipliers for prices relative to carbon steel or other standard materials are given for many for many of the items covered here. Usually only the parts in contact with process substances need be of special construction, so that, in general, the multipliers are not always as great as they are for vessels that are made entirely of special materials. Thus, when the tube side of an exchanger is special and the shell is carbon steel, the multiplier will vary with the amount of tube surface, as shown in that section. For multipliers see Table 3. As with most collections of data, the price data correlated here exhibit a certain amount of scatter. This is due in part to the incomplete characterizations in terms of which the correlations are made, but also to variations among manufacturers, qualities of construction, design differences, market situations, and other factors. Accordingly, the accuracy of the correlations cannot be claimed to be better than ^ 25% or so. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 408 TABLE 3 Equipment Multipliers for Installed Costs of Process Equipmenta Multiplier 1.3 1.2 1.5 1.4 1.3 1.4 1.5 1.3 1.2 1.2 3.0 2.1 1.3 1.5 1.4 1.2 1.3 1.9 1.4 1.6 1.4 1.7 Equipment Evaporators, calandria thin film, carbon steel thin film, stainless steel Extruders, compounding Fans Filters, all types Furnaces, direct fired Gas holders Granulators for plastic Heat exchangers, air cooled, carbon steel coil in shell, stainless steel Glass Graphite plate, stainless steel plate, carbon steel shell and tube, stainless/stainless steel shell and tube, carbon/stainless steel Heat exchangers, shell and tube, carbon/steel/aluminum shell and tube, carbon steel/copper shell and tube, carbon steel/Monal shell and tube, Monel/Monel shell and tube, carbon steel/Hastelloy Multiplier 1.5 2.5 1.9 1.5 1.4 1.4 1.3 1.3 1.5 2.5 1.7 2.2 2.0 1.5 1.7 1.9 2.1 2.2 2.0 1.8 1.6 1.4 Agitators, carbon steel stainless steel Air heaters, all types Beaters Blenders Blowers Boilers Centrifuges, carbon steel stainless steel Chimneys and stacks Columns, distillation, carbon steel distillation, stainless steel Compressors, motor driven steam on gas driven Conveyors and elevators Cooling tower, concrete Crushers, classifiers and mills Crystallizers Cyclones Dryers, spray and air other Ejectors Appendix C TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. Equipment Cost-Capacity Algorithms Instruments, all types Miscellaneous, carbon steel stainless steel Pumps, centrifugal, carbon steel centrifugal, stainless steel centrifugal, Hastelloy trim centrifugal, nickel trim centrifugal, Monel trim centrifugal, titanium trim all others, stainless steel all others, carbon steel Reactor kettles, carbon steel kettles, glass lined kettles, carbon steel Reactors, multitubular, stainless steel multitubular, copper a 2.5 2.0 1.5 2.8 2.0 1.4 1.7 1.7 1.4 1.4 1.6 1.9 2.1 1.9 1.6 1.8 multitubular, carbon steel Refrigeration plant Steam drums Sum of equipment costs, stainless steel Sum of equipment costs, carbon steel Tanks, process, stainless steel Tanks, process, copper process, aluminum storage, stainless steel storage, aluminum storage, carbon steel field erected, stainless steel field erected, carbon steel Turbines Vessels, pressure, stainless steel pressure, carbon steel 2.2 1.5 2.0 1.8 2.0 1.8 1.9 2.0 1.5 1.7 2.3 1.2 1.4 1.5 1.7 2.8 [J. Gran, Chem. Eng., (6 Apr. 1981)]. Installed Cost (purchase price)(multiplier). Note: The multipliers have remained essentially the same through late 2002. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. 410 Appendix C REFERENCE 1. SM Walas. Chemical Process Equipment: Selection and Design. Woburn, MA: Butterworth, 1988. TM Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved. ...
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