Chapter 22 (p558-597) CH EN 4253 Terry A. Ring Equipment Costing Chapter 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

Accounting 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 Estimate

Purchase 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) average

Pumps & 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*∑CP

Fans Fan Motor size by PC=QHt(in. water)/(6,350 ηFηM) 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*∑CP

Blowers Sizing factor is the power consumption, PC Centrifugal (turbo) Blower CB=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*∑CP

Compressors 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 = 2.15

Heat Exchangers Types of Heat exchangers Size Factor is HX area, A 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=2.19

Pressure Vessels Storage Tanks Distillation Towers Absorber Towers Tray Packed Absorber Towers Stripping Towers

Pressure 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 lb CB=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*∑CP

Hoop 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 used

Distillation 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*∑CP

Packed 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, 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