Equipment CostingChapter 22 (p558-597) CH EN 4253 Terry A. Ring 6/10th scale up/down Factor • Used for scaling the total capital cost for a chemical plant of a different size • Cost2/Cost1 = (Capacity2/Capacity1)0.6 • Accounts for economy-of-scale CB. = Historical price at Ibase – I is a Cost Index at present time • Chemical Engineering.Accounting for Inflation • Cost to purchase = Base Cost*(I/Ibase) – Base Cost. Plant Cost Index • Marshall and Swift (MS) Equipment Cost Index • Nelson-Farrar (NF) Refinery Construction Cost Index • Engineering News-Record (ENR) Construction Cost Index – Cp(I) = Cp(Ibase)*(I/Ibase) – Cp(Ibase)=FT*Fm*Cbase(Ibase) . CE. . m =materials factor – CTCI= ∑ CBM_i • Quote Estimate . p = pressure factor.62.6 • Study Estimate (±35%) – Method of Lang • CTCI=1.05*fL-TCI ∑ (Ii/Ibase-i) Cp-i • Lang factors for different types of Plants – Solids -3. Fluids 4.10.Cost Estimate Methods • Order of Magnitude Estimate – Method of Hill • Marshall Swift for I/Ibase • Six Tenths Rule for Production Capacity – CTCI-2 (I)=CTCI-1 (Ibase)*(I/Ibase)* (Capacity2/Capacity1)0. Solids&Fluids 3.73 • Sum over all major equipment • Preliminary Estimate (±20%) – Method of Guthrie – Bare module cost. CBM= Cp-base(I/Ibase)[FBM+(FdFpFm-1)] • d= design factor. S.Purchase Costs for Equipment • Size Factor. depends on type of equipment • Cp(Ibase)=A*(S)b • Cp(Ibase)=exp(Ao+A1[lnS]+A2[lnS]2+…) • Your book gives 2006 base costs • Ibase = 500 (2006) average . 2951. ρ = density • Efficiencies (pump and motor) are a function of flow rate and break horsepower (power without any losses).0519[ln(S)]2) Cp=FTFMatCB Fm materials factor see Table 22. CB=exp(9.0035549[ln(PC)]4} • Cp=FTCB • FT= motor types factor see Table 22.000ηpηM) • Q= flow rate.4866+0. PC=PT/ηp/ηM=PB/ηM=QHρ/(33. etc. respectively • CB=exp{5.21 FT pump type factor see Table 22. FBM=3.3 – CBM=FBM*∑CP • Size Factor=Power consumption. Gear.5 Base Cost. S=Q(Head)0. H = head.20 Other types of pumps have different CB formulas – Electric Motor to drive pump – Installation.053255 [ln(PC)]2 +0. Plunger) – Centrifugal Pump • • • • • • Size factor.028628 [ln(PC)]30.013141[ln(PC)]+0.22 • ηM=~90% .6019[ln(S)] +0.Pumps & Electric Motors • Pump Types (Centrifugal.0. Q Different CB formula for different types of fans CP=FHFM CB FH Head factor see Table 22.350 ηFηM) • ηM =~90%.8 2.24 FM material of construction factor • Fiberglass • Stainless steel • Nickel Alloy 1. water)/(6.15 • CBM=FBM*∑CP .5 5.Fans • Fan – – – – – Sizing factor is the volumetric flow rate. FBM = 2.0 • Motor size by PC=QHt(in. 15 • CBM=FBM*∑CP . PC • Centrifugal (turbo) Blower CB=exp{6.350 ηFηM) – ηM =90% . FBM = 2.7900[ln(Pc)]} • CP=Fm-fansCB • Motor – Motor size by PC=QHt(in.Blowers • Sizing factor is the power consumption.6547+0. water)/(6. CB=exp{7.Compressors • Compressor types – Centrifugal.6084+0.0 Carbon steel. 1. PC=PB/ηC • CP=FDriveFMatCB • • • • FDrive =1 (electric motor).80[ln(PC)]} – Screw. 2. CB=exp{7.5 SS.15 .0 Nickel Alloy CBM=FBM*∑CP FBM = 2. CB=exp{7.25 (gas turbine) FMat = 1. 1.15 (steam).7243[ln(PC)]} • Size factor is the power consumed. 5.7661+0.80[ln(PC)]} – Reciprocating.2223+0. 25 a≥1. Fmat=a+(A/100)b.0017(P(psig)/100)2 • • • Materials Factor. FBM=3.0545-0. 1.Heat Exchangers • Types of Heat exchangers – – – – – – Floating. CB=exp{11.147-0. CB= Double pipe. A • CP=FpFMatFLCB • – Not for double pipe – Pressure Factor.667-0. CB=exp{11.8709[ln(A)]+0.80 (DP).1248-0.8709[ln(A)]+0.09005[ln(A)]2} Thermosiphon. Fp= 0.0 note error in first row of Table 22. 2.0 for 20 ft.5 Tube Length Factor FL= 1.17 (Fin/Fan) .9803+0.17 (S&T).09861[ln(A)]2} U-tube. a & b from Table 22.09005[ln(A)]2} Fixed Head. 1. on a sliding scale CBM = FBM*CP. CB=exp{7.967-0. CB=exp{11.16[ln(A)]} • Size Factor is HX area.018(P(psig)/100)+0.9186[ln(A)]+0.25 for 8 ft. CB=exp{11.09790[ln(A)]2} Kettle.9228[ln(A)]+0. 7 for stainless steel • CBM = FBM*CP.Fired Heaters • Size Factor is the heat duty. 1. FBM=2. Q • CB=exp{0.0175(P/500)2 • Fmat=1.08505+0.19 .986-0.0035(P(psig)\500)+0.766[ln(Q)]} • CP=FPFMatCB • FP=0.4 Cr-Mo alloy steel. Pressure Vessels • Storage Tanks • Distillation Towers – Tray – Packed • Absorber Towers • Stripping Towers . 8Di)tsρs • C=FMCB+CPL • FM= materials factor see Table 22.02297[ln(W)]2} – Horizontal. – Vertical. etc.20294 CB=exp{8.2330[ln(W)]+0.16 (V).26 – Installation.200<W<1. W • Horizontal Vessels.717-0.775-0. 3<Di<21 ft • CPL=1580(Di)0. FBM=4.Pressure Vessels • Sizing Factor is the weight of steel.18255[ln(W)]+0.1(Di)0.000.05 (H) – CBM=FBM*∑CP . 3<Di<12 ft • CPL=258. 3. W=π(Di+ts)(L+0.70684 • Weight.00 lb • Add Platform Costs.00 lb • Vertical Vessels.7396(L)0.000<W<920. 1.4333[ln(W)]2} CB=exp{6. 4. 2 Pd) S = max allowable stress for steel is f(T) E = weld efficiency (fraction) Minimum wall thickness for given diameters May add extra thickness for wind stresses.000psig but not for vacuum Pd=exp{0.0015655[ln(Po)]2} • • • • • • • Thickness (Hoop Stress Calculation) ts= PdDi/(2SE-1.000psig use Pd=1. ts • Design Pressure is function of operating pressure.Hoop Stress Calc for thickness.60608+0. Po – For Po> 1.1Po – For Po< 1. corrosion Different calculation for vacuum vessels – Also account for leakage when vacuum vessel is used .91615[ln(Po)]+0. FBM=4. f(D) – Carbon Steel FTM=1.Distillation Towers • Pressure vessel with plates or packing and additional nozzles and manholes • Tray Cost • NT= no.0 sieve. etc.0788 Di • Installation.0 – 316 SS FTM=1.401+0. 1. 1.16 – CBM=FBM*∑CP .25/(1.0414NT) • FTT = tray type.87 bubble cap • FTM= Materials. trays CT=NTFNTFTTFTMCBT • FNT= 1 for NT>20 otherwise FNT=2. VP • C=VpCPK+CDR • CPK= is installed cost per unit volume • Distributors cost.Packed Distillation Column • Pressure vessel with platforms plus packing • Packing Cost basis is volume of packing. CDR . Absorbers/Strippers • Pressure Vessel plus platforms and packing • Separate costs for blowers • Separate costs for motors . Other process equipment • Different sizing factors • Different basis cost equations • Same methods used for cost calculation . Other Process Equipment • Various Size Factors • Table 22.32 .