Equipment Costing6/10th scale up/down FactorAccounting for InflationSlide 4Cost Estimate MethodsPurchase Costs for EquipmentPumps & Electric MotorsFansBlowersCompressorsHeat ExchangersFired HeatersPressure VesselsSlide 14Hoop Stress Calc for thickness, tsDistillation TowersPacked Distillation ColumnAbsorbers/StrippersOther process equipmentOther Process EquipmentEquipment CostingChapter 22 (p558-597)CH EN 4253Terry A. Ring6/10th 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-scaleAccounting for Inflation•Cost to purchase = Base Cost*(I/Ibase)–Base Cost, CB, = Historical price at Ibase –I is a Cost Index at present time•Chemical Engineering, CE, 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)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)0.6•Study Estimate (±35%)–Method of Lang•CTCI=1.05*fL-TCI ∑ (Ii/Ibase-i) Cp-i•Lang factors for different types of Plants–Solids -3.10, Solids&Fluids 3.62, Fluids 4.73•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, p = pressure factor, m =materials factor–CTCI= ∑ CBM_i•Quote EstimatePurchase Costs for Equipment•Size Factor, S, 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) averagePumps & Electric Motors•Pump Types (Centrifugal, Gear, Plunger)–Centrifugal Pump•Size factor, S=Q(Head)0.5•Base Cost, CB=exp(9.2951- 0.6019[ln(S)] +0.0519[ln(S)]2)•Cp=FTFMatCB•Fm materials factor see Table 22.21•FT pump type factor see Table 22.20•Other types of pumps have different CB formulas–Electric Motor to drive pump•Size Factor=Power consumption, PC=PT/ηp/ηM=PB/ηM=QHρ/(33,000ηpηM)•Q= flow rate, H = head, ρ = density•Efficiencies (pump and motor) are a function of flow rate and break horsepower (power without any losses), respectively•CB=exp{5.4866+0.013141[ln(PC)]+0.053255 [ln(PC)]2 +0.028628 [ln(PC)]3-0.0035549[ln(PC)]4}•Cp=FTCB•FT= motor types factor see Table 22.22•ηM=~90%–Installation, etc, FBM=3.3–CBM=FBM*∑CPFans•Fan–Sizing factor is the volumetric flow rate, Q–Different CB formula for different types of fans–CP=FHFM CB–FH Head factor see Table 22.24–FM material of construction factor•Fiberglass 1.8•Stainless steel 2.5•Nickel Alloy 5.0•Motor size by PC=QHt(in. water)/(6,350 ηFηM)•ηM =~90%, FBM = 2.15•CBM=FBM*∑CPBlowers•Sizing factor is the power consumption, PC•Centrifugal (turbo) BlowerCB=exp{6.6547+0.7900[ln(Pc)]}•CP=Fm-fansCB•Motor –Motor size by PC=QHt(in. water)/(6,350 ηFηM)–ηM =90% , FBM = 2.15•CBM=FBM*∑CPCompressors•Compressor types–Centrifugal, CB=exp{7.2223+0.80[ln(PC)]}–Reciprocating, CB=exp{7.6084+0.80[ln(PC)]}–Screw, CB=exp{7.7661+0.7243[ln(PC)]}•Size factor is the power consumed, PC=PB/ηC•CP=FDriveFMatCB•FDrive =1 (electric motor), 1.15 (steam), 1.25 (gas turbine)•FMat = 1.0 Carbon steel, 2.5 SS, 5.0 Nickel Alloy•CBM=FBM*∑CP•FBM = 2.15Heat Exchangers•Types of Heat exchangers–Floating, CB=exp{11.667-0.8709[ln(A)]+0.09005[ln(A)]2}–Fixed Head, CB=exp{11.0545-0.9228[ln(A)]+0.09861[ln(A)]2}–U-tube, CB=exp{11.147-0.9186[ln(A)]+0.09790[ln(A)]2}–Kettle, CB=exp{11.967-0.8709[ln(A)]+0.09005[ln(A)]2}–Thermosiphon, CB=–Double pipe, CB=exp{7.1248-0.16[ln(A)]}•Size Factor is HX area, A•CP=FpFMatFLCB•Pressure Factor, Fp= 0.9803+0.018(P(psig)/100)+0.0017(P(psig)/100)2–Not for double pipe•Materials Factor, Fmat=a+(A/100)b, a & b from Table 22.25 –a≥1.0 note error in first row of Table 22.5 •Tube Length Factor FL= 1.25 for 8 ft, 1.0 for 20 ft. on a sliding scale•CBM = FBM*CP, FBM=3.17 (S&T), 1.80 (DP), 2.17 (Fin/Fan)Fired Heaters•Size Factor is the heat duty, Q•CB=exp{0.08505+0.766[ln(Q)]}•CP=FPFMatCB•FP=0.986-0.0035(P(psig)\500)+0.0175(P/500)2•Fmat=1.4 Cr-Mo alloy steel, 1.7 for stainless steel•CBM = FBM*CP, FBM=2.19Pressure Vessels•Storage Tanks•Distillation Towers–Tray–Packed•Absorber Towers•Stripping TowersPressure Vessels•Sizing Factor is the weight of steel, W•Horizontal Vessels, 1,000<W<920,00 lb CB=exp{8.717-0.2330[ln(W)]+0.4333[ln(W)]2}•Vertical Vessels, 4,200<W<1,000,00 lbCB=exp{6.775-0.18255[ln(W)]+0.02297[ln(W)]2}•Add Platform Costs, –Horizontal, 3<Di<12 ft•CPL=1580(Di)0.20294–Vertical, 3<Di<21 ft•CPL=258.1(Di)0.7396(L)0.70684•Weight, W=π(Di+ts)(L+0.8Di)tsρs•C=FMCB+CPL•FM= materials factor see Table 22.26–Installation, etc, FBM=4.16 (V), 3.05 (H)–CBM=FBM*∑CPHoop Stress Calc for thickness, ts•Design Pressure is function of operating pressure, Po–For Po> 1,000psig use Pd=1.1Po–For Po< 1,000psig but not for vacuum Pd=exp{0.60608+0.91615[ln(Po)]+0.0015655[ln(Po)]2}•Thickness (Hoop Stress Calculation)•ts= PdDi/(2SE-1.2 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, corrosion•Different calculation for vacuum vessels–Also account for leakage when vacuum vessel is usedDistillation Towers•Pressure vessel with plates or packing and additional nozzles and manholes•Tray Cost CT=NTFNTFTTFTMCBT•NT= no. trays•FNT= 1 for NT>20 otherwise FNT=2.25/(1.0414NT)•FTT = tray type, 1.0 sieve, 1.87 bubble cap•FTM= Materials, f(D)–Carbon Steel FTM=1.0–316 SS FTM=1.401+0.0788 Di•Installation, etc, FBM=4.16–CBM=FBM*∑CPPacked Distillation Column•Pressure vessel with platforms plus packing•Packing Cost basis is volume of packing, VP•C=VpCPK+CDR•CPK= is installed cost per unit volume•Distributors cost, CDRAbsorbers/Strippers•Pressure Vessel plus platforms and packing •Separate costs for blowers•Separate costs for motorsOther process equipment•Different sizing factors•Different basis cost equations•Same methods used for cost calculationOther Process Equipment•Various Size Factors•Table