垂直多孔通道中的变质量流动

31Vol.3No.120032TheChineseJournalofProcessEngineeringFeb.2003,(200237).0.771.2610%15%..O351A1009–606X(2003)01–0001–071[1,2]..[3]0.6041~0.1561(wA2–wB2)/wA2[4]kd=0.57+0.15wB/wAkc=0.98+0.17wA/wBkd0.72,kc1.15[5]φ50mm(0.605±0.0109)u/w[6]φ32mm(0.475±0.015)u/w.[7–10]φ500mm0.684+0.0128(dw/dz)/w1.135+0.0158(dw/dz)/w.gWcOzudzp+dp,w+dwp,w,22.21(1)z,z(2).z1Fig.1Differentialelementoftheverticalperforatedchannel2002–07–27,2002–11–24(:2000)(1967–).23z.cd0AwAu.+=(1)()()22wcddddc.pAppAgAzDzAwwzAwAuwρτπρρρ−++−=+−+(2)2,4ADπ=cd,ADzπβ=2w,8wρτλ=(1)(2)dw2cdd2d2ddpwgλρρρρ−++−=(3)wc=2αwαd1kα=−,(4)2ddd2dd2pwgkww0.zzDλρρρ−++=(5)2ddd2dd2pwgkww0.zzDλρρρ+++=(6)2cdd2dd2pwgkww0.zzDλρρρ±++=(7)+–.3(1)2,3.1.Blower2.Valve3.Thermalcouple4.Flowmeter5.RadialpackedbedHDoDiDsAirVentVent54321AirFT23Fig.2FlowsheetoftheexperimentalfacilitiesFig.3Sketchofthemock-upcolumn131Table1Dimensionsofthemock-upandtheexperimentalconditionConfigurationDs(m)H(m)Di(m)Do(m)Dp(mm)Q(m3/h)Columnof120°sector(A)3.04.01.22.4φ3~510000Fullcylindricalcolumn(B)3.08.01.22.4φ3~536000..φ3~5mmφ2mm×8mm30%100mm..30~50oC300~1500Pa,1.2kg/m31.8×10–5Pa.s.JM–9(0~1470Pa0.1Pa,)()QDF–3(0~10m/s5~30m/s≤5%)QDF–2B(0~5m/s0.05m/s≤3%).4(5)nikdi+1()()()211d111122()22iiiiiiiiiippgzgzkλρρρ++++++−±−+−+−=(8)()()()211d111122()22iiiiiiiiiipgzpgzkλρρρ++++++±−±+−+−=pv=p±ρgz+–112.2iii(9)pi+1pe,i+1(21e,11,niiiSpp++=−∑)(10)[11]Skd.kc.λ1218.71.742lgDReελλ=−+0.01mm.4355.1u.φ3000mm5000~9000m3/h,wz,uz.22wDρλ0.8Pa/md2dwwzρ24Pa/m.5.245328004200m3/hppv.0.00.51.01.52.02.53.03.54.095096097098099010001010p(Pa)z(m)pvepeQ=4200m3/h012345678220240260280300320p(Pa)z(m)pvepeQ=32800m3/h4(B)5Fig.4PressureandvirtualpressureprofilealongchannelFig.5Pressureandvirtualpressureprofilealongchannelunderupwardsplittingflowunderdownwardsplittingflow(1),11.8Pa/m,.(2).(3).u2.0.7710%0.72[4].152Table2MomentumexchangecoefficientsforsplittingflowMainflowL(m)Q(m3/h)w0(m/s)Re0×10–5kdUpward(A)3.459004.323.620.766Upward(A)3.472005.244.390.804Upward(A)3.678805.814.870.760Upward(A)3.685006.265.240.823Upward(A)3.687006.375.330.804Downward(A)3.685406.305.280.746Downward(A)3.642003.042.550.714Upward(B)7.2328008.066.450.829Upward(B)7.2318007.826.260.826Upward(B)7.6340208.366.690.692Upward(B)7.6335508.246.590.816Upward(B)7.6331208.136.500.792Downward(B)7.0331508.146.510.706Downward(B)7.0325808.006.400.7585.3677200m3/h.0.00.51.01.52.02.53.03.5100110120130140p(Pa)z(m)pvepeQ=7200m3/h0.00.51.01.52.02.53.0-40-30-20-10010p(Pa)z(m)pvepeQ=7200m3/h6(A)7(A)Fig.6PressureandvirtualpressureprofilealongchannelFig.7Pressureandvirtualpressureprofilealongchannelunderupwardcollectingflowunderdownwardcollectingflow(1).(2)(3).633.3Table3MomentumexchangecoefficientsforcollectingflowMainflowL(m)D(m)Q(m3/h)w0(m/s)Re010–5kcUpward(B)7.00.60270002.951.181.10Upward(A)3.00.5672002.400.901.44Upward(A)3.00.5679202.580.961.41Upward(A)3.00.5687502.871.071.10Upward(A)3.00.5690002.931.091.07Downward(B)3.31.25672005.094.261.423,1.2615%1.15[4].,[3–6].ρgddwkw2zρ.6.(1)()2dd20dd2pgzwkwwzzDρλρρ±++.=+–.(2)0.7710%1.26±15%[4].(3),.A(m2)pe(Pa)Ac(m2)pii(Pa)D(m)pe,ii(Pa)Ds(m)Q(m3/h)Di(m)Re0Do(m)u(m/s)Dp(m)w(m/s)g(m/s2)w0(m/s)H(m)wii(m/s)kwc(m/s)17kcz(m)kdzii(m)L(m)αipvp±ρgz(Pa)λpvepe±ρgz(Pa)ρ(kg/m3)p(Pa)τw(N/m2)[1]BassiounyMK,MartinH.FlowDistributionandPressureDropinPlateHeatExchangers[J].Chem.Eng.Sci.,1984,39(4):693–670.[2]GenkinVS,DilmanVV,SergeevSP.TheDistributionofaGasStreamovertheHeightofaCatalystBedinaRadialContactApparatus[J].Inter.Chem.Eng.,1973,13(1):24–28.[3],,,.[J]..1984,35(3):203–212.[4],,,.[J].,1979,30(1):67–88.[5],.[J].,1990,18(3):28–34.[6],,,.[J].,1993,21(3):22–29.[7],,.[J].,1992,43(3):268–274.[8],,,.[J].,1992,7(1):41–51.[9],,,.[J].,1993,8(1):107–113.[10],,,.[J].,1997,28(4):47–53.[11].[M].:,1985.249.Variable-massFlowthroughtheVerticalPerforatedChannelsXUZhi-gang,YUFeng,LIRui-jiang,WUYong-qiang,ZHUZi-bin,ZHANGCheng-fang(InstituteofChemicalEngineering,EastChinaUniversityofScienceandTechnology,Shanghai200237,China)Abstract:Themomentumequationwithgravityconsideredwasappliedtodescribethevariable-massflowintheverticalperforatedchannelforradialpackedreactors.Theprofilesofpressureandthevirtualpressurealongtheperforatedchannelsweremeasuredforupwardanddownwardflowsinthedistributororcollectoronlargescalemock-up.Undertheexperimentalconditions,thecoefficientsofmomentumexchangefordistributionandcollectionwerecalculatedtobeequalto0.77withtheaveragerelativeerrorof10%and1.26withtheaveragerelativeerrorof15%respectively.Itisconcludedthatgravitycannotbeneglectedasthemassvelocityisrelativelysmall.Keywords:perforatedchannel;variable-massflow;momentumexchange