CFB脱硫塔设计计算

Preparedby:ColumnTagNo.:HCLScrubberCheckedby:JobNo.:4506ADate:Client:JOLProject:SR-Plant-4,5InputDataStream:HCLVap.Packingtype=IntalloxSaddlesPackingsize=25mmPackingMOC=PPGaspr.Drop/mbed=15mmWC/mpackingheight=147.1(N/m2)/mTotalpackingheight=3.2m(includingallpackedbeds)Gas/VapourPropertiesGas/Airflowrate=1000kg/hOR0m3/h=0.2778kg/s=0m3/sGaspressureatentry=1.0000atmGastemperatureatentry=30.00oC=303.00oKGas/Airmolweight=29ComponenttobescrubbedComponentName=HCLVapComponentflowrate=70Kg/h%comp.inair/gas=6%(v/v)(presumed)/(givenbyclient)/(byprocesscal.)Molecularweightofcomp.=36.5Liquid/ScrubbingmediaPropertiesScrubbingmedia=20%NaOHLiquidflowrate,L=77kg/h=0.0214kg/sLiquidDensity,L=1100kg/m3Conversion:LiquidViscosity,µL=0.0035000Ns/m23.5Cp=Ns/m2Packingfactor,Fp=21m-1Charac.PackingFactor,Cf=33Ref.Table6.3,CharactersticsofRandompackingsConversionfactor,J=1.0factorforadequateliquiddistribution&irrigationacrossthebedSCRUBBERDESIGN(PACKEDCOLUMN)0.00350000Sheet1of11CalculationsSincelargerflowquantitiesareatthebottomforanabsorber,thediameterwillbechosentoaccommodatethebottomconditions.TocalculateGasdensityAvg.molecularweight=29.45Kg/KmolIfgasflowrateisgiveninkg/hIfgasflowrateisgiveninm3/hGasin=0.009432183Kmol/sGasin=(m3/s)x273xpr.inatmx1kmol=mass/molwtTinkelvin1.0atm22.4=(kmol/s)xTinkelvinx1.0atmx22.4273pr.Inatm1=0Kmol/s=0.234499m3/s=0Kg/smass=molwtxkmolSelectvol.flowrateandmassflowratefromabove,Selectedmassflowrate=0.277778Kg/sSelectedvol.Flowrate=0.234499m3/sSelectedmolarflowrate=0.009432Kmol/sTherefore,gasdensity=1.1846Kg/m3(massflowrate/vol.Flowrate)TofindL',G'andTowerc/sareaAssumingessentiallycompleteabsorbtion,Componentremoved=0.0207Kg/s(molarflowratex%comp.xmol.Wt.)Liquidleaving=0.0420Kg/s(Inletliquidflowrate+comp.Removed)L'G0.5=0.00497G'LUsing0.00497asordinate,Referfig.6.34usingagaspressuredropof147.1(N/m2)/mG'2CfµL0.1J=0.04(fromgraph)G(L--G)gcTherefore,G'=0.04G(L--G)gc0.5CfµL0.1J=1.6665Kg/m2.sTowerc/sarea=0.1667m2(c/sarea=massflowrate/G')Towerdiameter=0.4607m=460.7mm=500mmCorrespondingc/sarea=0.1963m2TOCALCULATECOLUMNDIAMETERSheet2of11Efficiencyoffan/blower=60%assumed/givenTocalculatepressuredropPressuredropforirrigated=470.72N/m2(pressuredroppermpackingxtotalht.ofpacking)packingFordrypacking,O/LGasflowrate,G'=1.3095Kg/m2.s(Gasinletflowrate-Componentremoved)/c/sareaO/LGaspressure=100854.3N/m2(subtractingpressuredropacrosspacking)Gasdensity,G=gasmolwt.x273xgaso/lpr.22.41m3/KmolTinkelvin101330=1.1605Kg/m3CD=96.7Ref.Table6.3,CharactersticsofRandompackingsDeltaP=CDG'2ZG=142.89N/m2Pressuredropforpacking=613.61N/m2(irrigatedpacking+drypacking)Pressuredropforinternals=25mmWC(packingsupportsandliquiddistributors)=245.17N/m2Gasvelocity=7.5m/sInletexpansion&outlet=1.5xVelocityheads=1.5x(V2/2g)contractionlosses=42.19Nm/Kg=49.97N/m2(dividebydensity)Totalpressuredrop=908.75N/m2(packing+internals+losses)Fanpoweroutput=pressuredrop,N/m2x(gasin-componentremoved)Kg/sO/Lgasdensity,Kg/m3=201.35N.m/s=0.20kWPowerforfanmotor=0.34kW(fanpoweroutput/motorefficiency)=0.45hpTOESTIMATEPOWERREQUIREMENTSheet3of11Liq.-Vap.Flowfactor,FLV=(L/V)x(V/L)=0.0025Designforaninitialpressuredropof15mmH2O/mpackingFromK4v/sFLV,K4=0.85K4atflooding=6.50Trial%flooding=((K4/K4atflooding))x100=36.1620Gasmassflowrate,Vm=K4.V(L--V)13.1Fp(µL/L)0.1=3.7763kg/m2.sTrialcolumnc/sarea=V/Vm(TrialAs)=0.0736m2Trialcolumndia.,D=0.3060mD=(4/pi)xTrialAsRoundoff'D'toneareststandardsizeTherefore,D=0.500mColumnC/Sarea,As=0.1963m2As=(pi/4)xD2%flooding=13.5472%flooding=Trial%floodingx(TrialAs/As)ConclusionGenerallypackedtowersaredesignedfor50%--85%flooding.Iffloodingistobereduced,(i)Selectlargerpackingsizeandrepeattheabovesteps.OR(ii)Increasethecolumndiameterandrepeattheabovesteps.COLUMNDIAMETER/HYDRAULICCHECK(1/2)Sheet4of11Norton'sCorrelation:lnHETP=n-0.187ln+0.213lnµApplicablewhen,liquidphasesurfacetension4dyne/cm&36dyne/cmliquidviscosity0.08cP&0.83cPConversion:InputData0.018N/m=dyne/cmLiquid-phaseSurfaceTension,=20dyne/cmLiquidViscosity=3.5cPn=1.13080CalculationlnHETP=0.837437HETP=2.310437ft=0.704221mForseparations,lessthan15theoriticalstages,a20%designsafetyfactorcanbeapplied.Considering20%safetyfactor,HETP=0.845065mForseparations,requiring15to25theoriticalstages,a15%designsafetyfactorcanbeapplied.Considering15%safetyfactor,HETP=0.809854mHETPPREDICTIONNorton'sCorrelationApplicableNorton'sCorrelationNOTapplicable18Sheet5of11ConstantforHETPCorrelationRef.::RandomPackingsandPackedTowers----StrigleTable6.2Ref.::ChemicalEngineering,Volume-6,COULSON&RICHARDSON'SRef.::MassTransferOperation::Treybal