課程設(shè)計(jì)題目苯-氯苯分離過(guò)程板式精餾塔設(shè)計(jì)96%勺餾來(lái)完成該分離任務(wù)；原min3.回流比自定(取2.4R);min4.塔釜加熱蒸汽壓力506kPa(表壓);大于0.7kPa;苯760Pi°32.組分的液相密度32.組分的液相密度苯P純組分在任何溫度下的密度可由下式計(jì)算=912.13-1.1886t氯苯p=1124.4-1.0657t0BOABOAX'OBXB 4.氯苯的汽化潛熱常壓沸點(diǎn)下的汽化潛熱為式表示:kmolttc=359.2C) 定的時(shí)間然后進(jìn)入苯的儲(chǔ)罐，而其中的氣態(tài)部分重新回到精餾塔中，即回流。而液相混合 (1)料液及塔頂?shù)桩a(chǎn)品含苯的摩爾分率45/78.1145/78.1155/112.6196/78.11X-0.972D96/78.114/112.61 2/78.113.組分的表面張力(T(mN/m苯雙組分混合液體的表面張力陌可按下式計(jì)算: (2)平均摩爾質(zhì)量MF10.542(1-0.542)11261=93.91kg/kmolMD.110.972(1-0.972)11261=79.08kg/kmolMW)112.6仁111.6kg/kmolFDW0.45F'=0.96D'0.02W'二D^1429.52kg/hW=1695.47kg/hDkmolhW=15.19kmol/hT (1)相平衡數(shù)據(jù)的求取根據(jù)苯-氯苯的相平衡數(shù)據(jù)，利用泡點(diǎn)方程和露點(diǎn)方程求取Pi° 苯xy0011本題中，塔內(nèi)壓力接近常壓(實(shí)際上略高于常壓)，而表中所給為常壓下的相平衡數(shù)據(jù)，因?yàn)椴僮鲏毫ζx常壓很小，所以其對(duì)x~y平衡關(guān)系的影響完全可以忽略。 (2)確定操作的回流比Rx二X=0.542時(shí)，泡點(diǎn)溫度為95.4C,平均溫度F95457.7330.7K2Cp=ABTCT2DT32323p(6.1906E-1)T(—6.346E—3)T2(1.8478E—6)T3Cp1=143.42kJ/(kmolK),Cp2=157.15kJ/(kmolK).Cp=Cp10.542Cp20.458=149.71kJ/(kmolK)原料液汽化熱.治=0.542393.978.110.458325112.61=18402.66kJ/kmolq1.611Cp：trm149.71(95.4-20)q1.611rm18402.66b圖得yyx~y曲線qXFxq-1q-1q1.611q-11.611-1cQ"2.637DDy=y=RxXD“30X0.69R1--------=------------=---------------------------=------------=-------------------=0.2二R1R1x-x0.972-0.682mDf所以R=0.24Rmin=0.6 (3)求理論塔板數(shù)圖解得NT=7.5「1=6.5塊(不含塔釜)。其中，精餾段NTI=3塊，提餾段NT2=3.5塊，第5 (1)全塔效率ET選用ET=0.17-0.616log軸公式計(jì)算。該式適用于液相粘度為0.07~1.4mPa?s的烴類物系，式中的(Jm為全塔平均溫度下以進(jìn)料組成表示的平均粘度。J=亠人斥」B(1-斥)=0.240.5420.34(1-0.542)=0.286總塔板數(shù)Np=Np1?Np2=13塊a塔頂：y1=XD=0.9721=0.892MVD,m=0.972x78.11+(1—0.972)x112.61=79.08MLD,m=0.892x78.11+(1—0.892)x112.61=81.84加料板：y2=0.9,X2=0.64MvF,m=0.9x78.11+(1—0.9)X112.61=81.56MLF,m=0.64漢78.11+(1—0.64)匯112.61=90.53塔底：y3=0.06,3=0.02M'=0.0278.11M'=0.0278.11(1-0.06)112.61=110.54(1-0.02)112.61=111.92mML,m=(81.84+90.53)/2=86.19ML,m'=(90.53+111.92)/2=101.23(4)平均密度(kg/m3)A=912.13-1.1886t=912.13-1.188680=817.0=1124.4-1.0657t=1124.4-1.065780二1039.1A817.01039.1=824.0PLDmTLF,A=912.13-1.1886t=912.13-1.188695.4=798.7LB=1124.4—1.0657t=1124.4-1.065795.4二1023.2aBa6,m‘LF,AB0.450.55908798.7*1023.2二LF,m_.3仏仏'=912.13-1.1886t=912.13-1.1886131.8=755.5=1124.4-1.0657t=1124.4-1.0657131.8=983.91aAaAaBa旦75559839LWm,mFFrL,m=[824.0908.3/2=866.152.汽相平均密度p,m2.汽相平均密度p,m=3.314Pm'MVm……一?8.314273113.621.0826.02<!AXB+UB21.0826.02<!AXB+UBXAJD121.08x0.028+26.02x0.972丿19.23=21.31F,m19.230.45824.450.542JAXBBXA(5)液體的平均表面張力cm(mN/m)-1523AWB=20.31(131.8C)BW,m15.23X20.31]15.23X20.31||—J5.23X0.9714+20.31匯0.0286丿精餾段：匚二21.1921.31/2=21.25=20.1221.31/2=20.72％(mPas),mJW,A=0.217mPas,%B=0.301mPas(131.8C)MLDmMAXALMBXBLx=0.317mPas,加料板：％m=0.2790.5420.3750.458=0.323mPas,LLLL塔底:」LW,m一」AXAWZ」BXBW=°.2170.02860.3010.9714=0.399mPas,精餾段：Pm=(0.323+0.317y2=0.32mPas,,Pm9y2=0.361mPa-s,里V=R1D=1.618.08=28.93kmol/hVM28.93x80.32Vh=0.2265m3/s=815m3/h液相回流摩爾流率L二RD二0.618.08二10.85kmol/h液相體積流量Lh=0.0002m3/s=1.08m3/h冷凝器的熱負(fù)荷Q=Vr=28.9380.32393.9/3600=254.25kW汽相摩爾流率V—V(q-1)F=28.93(1.611-1)33.28=49.26kmol/hV'M'm,0漢3.314397m/shV'=0.397m3/s=1429m3/hh液相回流摩爾流率s-LM液相回流摩爾流率s-LM4510123液相體積流量L,m3液相體積流量L,m33600PL,m'3600743.15液相體積流量Lh』0.0019m3/3600PL,m'3600743.15液相體積流量Lh』0.0019m3/s=6.918m3/h七、精餾段塔和塔板主要工藝結(jié)構(gòu)尺寸的計(jì)算1)塔徑mTLH-h=0.35-0.06二TL2.按Smith法求取允許的空塔氣速Umax(即泛點(diǎn)氣速UF)9.0003『866.15『<0.2265人2.850丿=0.02309c0.2c負(fù)荷因子C二C20—I=0.07沃<20J泛點(diǎn)氣速:(21.25學(xué)丿3.操作氣速，取u=0.7umax=0.864m/s4.精餾段的塔徑sDVu140.80^0.598ms2)塔板工藝結(jié)構(gòu)尺寸的設(shè)計(jì)與計(jì)算內(nèi)堰。①溢流堰長(zhǎng)(出口堰長(zhǎng))lw取lw=0.7D=0.71.0=0.7m堰上溢流強(qiáng)度Lh/lw=1.08/0.7=1.54m3/mh:::100~130m3/mh，滿足篩板九—hLhow對(duì)平直堰h(yuǎn)ow=0.00284E(Lh/lw嚴(yán)由lw/D=0.7及Lh/lw.5=1.08/0.72.5=2.54，查得E=1.02，于是:how=0.002841.021.08/0.72/3=0.004m<0.006m(不滿足要求)對(duì)齒形堰gw=0.044240/5)2/5hw=m—'how=0.06—0.0083=0.0517m③降液管的寬度Wd和降液管的面積Af由匚/D=0.7，查得Wd/D=0.14,Af/AT=0.09，即：Wd=0.14m，AT=0.785D2=0.785m2，Af=0.115m2。留時(shí)間.=AfHT/Ls=0.1150.35/0.0003=134.17s5s(滿足要求)uo=0.02m/s，則有：oLswolwox22.塔板布置⑦邊緣區(qū)寬度Wc與安定區(qū)寬度ws安定區(qū)寬度Ws:規(guī)定D<1.5m時(shí)Ws=75mmD>1.5m時(shí)Ws=100mm本設(shè)計(jì)取Wc=50mmWs=75mm③開孔區(qū)面積AAa2X、R2-x2■-2_1X2R2sin0.242m2180R式中：x=D/2-WdWs=0.5-0.140.075=0.285mR=D/2—Wc=0.5—0.050=0.450m---------:6.516m/s4Vs=29擬定塔板采用碳鋼且按等腰三角形叉排，板厚5=3mm，且Wc=50mmWs=75mm0.075n%ssVs=4.98m/4.精餾段的塔高Z1Z1=Np1-1HT=6-10.3^1.75m八、提餾段塔和塔板主要工藝結(jié)構(gòu)尺寸的計(jì)算1)塔徑TLH-h=0.35-0.06二0.2TLumax'(即泛點(diǎn)氣速uF)=0.080740.0019「943.15=0.08074----------I-----------I10.397人3.314丿rcr'I0.2(負(fù)荷因子C'=C20'120丿泛點(diǎn)氣速:3.操作氣速，取u'=0.7umax'=0.782m/s4.精餾段的塔徑2)塔板工藝結(jié)構(gòu)尺寸的設(shè)計(jì)與計(jì)算內(nèi)堰。①溢流堰長(zhǎng)(出口堰長(zhǎng))lw取lw=0.7D=0.71.0=0.7m堰上溢流強(qiáng)度Lh'/lw=6.918/0.7=9.88m3/mh:：:100~130m3/mh，滿足篩板塔的堰W-hL-how對(duì)平直堰h(yuǎn)ow=0.00284ELh'/lw2/3由匚/D=0.7及Lh/lW.5=6.918/0.72.5=16.87，查得l%w=0.002841.036.918/0.72/3=0.0135mhw=hL-how=0.06-0.0135=0.0465m0.006m(滿足要求)管的寬度Wd和降液管的面積Af由lw/D=0.7，查得Wd/D=0.14,Af/AT=0.09，即：Wd=0.14m,AT=0.785D2=0.785m2,Af=0.115m2。留時(shí)間二AfHT/Ls=0.1150.35/0.0019=21.18s5s(滿足要求)ssh。hlwu00.70.02①②③AAxRxRSWE式x=D/2-WdWs=0.5-0.140.075=0.285mR=D/2-Wc=0.5-0.050=0.450m%6.042m/s3.314個(gè)擬定塔板采用碳鋼且按等腰三角形叉排，板厚5=3mm，且Wc=50mmWs=75mm作等腰三角形叉排時(shí)時(shí)，hA-0.059m，按推薦尺寸，此處取h「65mm。0.075n浮閥個(gè)數(shù)為57個(gè)。如圖2..V%s=5.83m/sdn471.2°4.精餾段的塔高Z1Z2二Np2-1HT=7-10.35二2.1m4-1豐密詢(SmiliLRB)關(guān)采啃然團(tuán)出-丈=機(jī)勒酥營(yíng)瑟到味面陳性校核 (1)塔板壓降校核hf=hche1?氣體通過(guò)干板的壓降hc/</182^ (Pv丿7^|=5.92m/scu12.850丿2.854.982=5.34=5.34=0.0222m866.1529.812?氣體通過(guò)板上液層的壓降he/曲21.2510「000700027m(顯然此項(xiàng)很小可忽略)(T；\gdo866.159.810.039hf和?巾fpf」〔ghf=866.1559.81 (2)霧沫夾帶量校核0.0300.00027=0.0525mPvkgmHTm,得CF=0.109。再根據(jù)表(化工原理課程設(shè)計(jì)5-13)取K=0.85?！鯝—Pv,100Vs■A—Pv,ACFK校核oooouuKU2.96om(4)降液管液泛校核為防止降液管發(fā)生液泛，應(yīng)使降液管中的清液層高度Hd乞①(HThw)Lhd0.0003；2hd=0.153-0.153hd=0.153wwoy60Hd=0.05250.00006Hd=0.0525①(HThw)①(HThw)=0.5(0.35dd十、提餾段塔板上的流體力學(xué)驗(yàn)算e1?氣體通過(guò)干板的壓降heoeG314丿0UoeG314丿02?氣體通過(guò)板上液層的壓降hehehwhowhL0=0.030m3?克服表面張力的壓降h._(—般情況下可不考慮)匕亙二士竺土衛(wèi)理0.00023m(T讓gdo943.159.810.039(顯然此項(xiàng)很小可忽略)4?氣體通過(guò)篩板的壓降(單板壓降)hf和'=pfhf=兀亠he亠h…=0.063maZ=D-2Wd=1-20.14=0.72m5-13)取K=0.85。(p'?5svsACK100V'svsACKF=.PL-Pv\112.41%--------------------LvaFasoouU2.75om(4)降液管液泛校核為防止降液管發(fā)生液泛，應(yīng)使降液管中的清液層高度Hd乞①(HThw)「L'!'000192臨=0.153=0.153=0.00006mHd=0.0630.0600.00006=0.1231m①(HThw)=0.5(0.350.0465)=0.198mThw通過(guò)流體力學(xué)驗(yàn)算，可認(rèn)為精餾段塔徑及塔板各工藝結(jié)構(gòu)尺寸合適，若要做出更合理的設(shè)一、精餾段塔板負(fù)荷性能圖2.85866.15—1.36866.15—s=0.80整理得到Vs=0.312-17.04Ls上限線)①(HThw)=hf-hwhow-hd、,—L'3600LS!w—0.00284Ew丿o4oA■nd2o4o/32/3LLI0.7丿20.0454m2n(VS/AO)幾2g%2g…2.85V2=5.34s22/3=0.0259十0.4231Ls//x.2h=0.153=0.153s$V2=0.284-2.92f3-1569.2s$(氣相負(fù)荷下限線)Xms}=3.928L}=3.928L^n=0.006.07how=0.00284.0733maxAfmmaxT4Vs/Ls=0.226/0.0003操作彈性定義為操作線與界限曲線交點(diǎn)的氣相最大負(fù)荷比，即:V操作彈性=巴Vs,minVs,max許最小負(fù)荷Vs,min之——茅沫來(lái)芾錢—?dú)饫碡?fù)荷上阪線—我相負(fù)荷下限線線精餾段塔板負(fù)荷性能圖十二、提餾段塔板負(fù)荷性能圖V3.3141.360.72Ls943.15—s=0.800.2420.2420.110.85整理得到Vs=0.305-16.49Ls2降液管液泛線(氣相負(fù)荷上限線)降液管發(fā)生液泛的條件為：①(HThw)二hf-hwhow-hdhow-0.00284E'3600LswLw/3=0.00284136002/