查图表u=Cmax€\3.78取安全系数为0.7,则:u=0.7xumax=0.7„2.14=1.047m/s故:D=旷时T=1.265m;V…xl.047按标准,塔径圆整为1.4m,塔和塔板的主要工艺尺寸的计算(一)塔径D参考下表初选板间距H=0.40m,取板上液层高度TH=0.07m故:L①精馏段:H-h=0.40-0.07=0.3TL/L、/€、丄/0.0023J394.3、丄(—)(L)2=()()2=0.0425V€1.043.78Cs=0.078;依公式20C=C(2)0.2=0.078(26.06)0.2=0.0733;20220€-Pccrc(1394.3-3.78,lv=0.078x=1.496m/s则空塔气速为u=t=竺凹=0.78m/s…D2…X1.32塔的横截面积A636m2T44②提馏段:/L、€'、丄/0.00277、/1574.8、丄(-)(J=()()2=0.0507;查图V'€'0.9565.14C=0.068;依公式:c=C(,)0.2=0.068xf22.09202020€'l_€v=0.0694匚5・14=1.213m/s€V5.14取安全系数为0.70,I20丿0.2=0.0694;u=Cmaxu'=0.7xu=0.7x1.213=0.849m/s;D'=^^6=1.20m;…x0.849max4V=齐=为了使得整体的美观及加工工艺的简单易化,在提馏段与精馏段的塔径相差不大的情况下选择相同的尺寸;故:D'取1.4m塔的横截面积1.42=1.327m2T44空塔气速为u',-4V^,4X0.956,0.720m/s€D2€X1.32板间距取0.4m合适二)溢流装置采用单溢流、弓形降液管、平形受液盘及平形溢流堰,不设进流堰。
各计算如下:①精馏段:1、溢流堰长l为0.7D,即:l,0.7x1.4,0.91m;2、出口堰高hh=h-hL12.5二-8竺,10.48m查手册hw0.912.5wwLow由l/D=0.91/1.4=0.7,w知:3、E为1.03依下式得堰上液高度:/L„2E-h11丿2.84h,ow1000故:3,竺X1.03(8・2810000.91丿„233,0.013mh,h-h,0.07-0.013,0.057mwLow降液管宽度W与降液管面积Adf有l/D=0.7查手册得W/D,0.14,A/A,0.08wdfT故:w=0.14D=0.14X1.3=0.182md€€A,0.08D2,0.08xx1.32,0.1062m2f44t,AfHT,0.1062x0.4,18.5s(>5s,符合要求)L0.00234、降液管底隙高度h0取液体通过降液管底隙的流速u=0.1m/s0依式计算降液管底隙高度h,0即:L0.0023即:h,—,,0.025m②提馏段:0lu0.91x0.1w01、溢流堰长1'为0.7d,即:l',0.7xl.4,0.91m;w2、出口堰高h'h'=h-h';wLow9.980.912.5E为1.04依下式得堰上液高度:l'/D=0.91/1.4=0.7wLl'2.5,hw,12.63m查手册知h'ow2.8410002.841000xl.049.9810.91h,0.07—0.0146,0.0554m。
0.0146mw3、降液管宽度W与降液管面积Adf有l/D=0.7查手册得W/D,0.14,A/A,0.08wdfT故:w‘=0.14D=0.14x1.4=0.182md兀兀A,0.08—D'2,0.08x—x1.42,0.1062m2f44t,也,010空04,18.5s(>5s,符合要求)降液管底隙高度h'L0.00230取液体通过降液管底隙的流速u=0.008m/s0依式计算降液管底隙高度h'0L'0.00142h',—,0l'u0.56x0.08(三)塔板布置,0.0317m1、取边缘区宽度w=0.035m,安定区宽度w=0.065mcs①精馏段:依下式计算开孔区面积€I兀xAA,2x(R2—x2+R2sin—1一…D180]3R丿其中x,——(W+W<,一—(0.182+0.065<,0.403m2ds2D1.3R,——W,—0.035,0.615m2c2故:€,A,20.40^/0.6152—0.4032+丄0.6152sin-1°:4031800.615丿,0.915m2②提馏段:依下式计算开孔区面积A'ac;兀.x',2x'寸R'2—x'2+R'2sin—1—I/180R'丿、、€丿兀0223A,20.22^/0.3652—0.2232+——0.3652sin—1—(1800.365丿=0.304m2其中x',——(W'+W'),08—(0.112+0.065<,0.223m2ds2D'0.8R'€—W€——0.035€0.365m2c2(四)筛孔数n与开孔率,取筛孔的孔径d为5mm正三角形排列,一般碳钢的板厚5为04mm,取t/d€3.5故孔中心距t=3.5„5.0=17.5mm0依下式计算塔板上筛孔数n,即A(1158„103、.17.521158„10312n€„0.915€3460孔依下式计算塔板上开孔区的开孔率,,即:,€A0%€竺1€7.5%(在5~15%范围内)A(t/d)2精馏段每层板上的开孔面积A为oA€,„A€0.075„0.915=0.0686m2o…气孔通过筛孔的气速u€二€丄也€15.16m/s0A0.6086提馏段每层板上的开孔面积A'为oA'€,„A'€0.101„0.304€0.0307m2o…气孔通过筛孔的气速u'€匚€0.627€20.42m/s0A'0.0307o五)塔有效高度精馏段Z€(1)„0.4=4.4m;精提馏段有效咼度Z€(61„0.4二.m;提在进料板上方开一人孔,其咼为0.8m,—般每68层塔板设一人孔(安装、检修用),需经常清洗时每隔3~4层块塔板处设一人孔。
设人孔处的板间距等于或大于600m根据此塔人孔设3个故:精馏塔有效咼度Z€Z+Z+3„0.8€8.0+2.0+2.4=12.4m精提。