化工原理课程设计设计,甲苯—二甲苯连续精馏筛板塔的设计(共18页)

1、 PAGE 21PAGE PAGE 21目录(ml)第一(dy)部分 工艺设计物料(w lio)衡算 2塔顶温度、塔底温度及Rmin 2确定最佳操作回流比及塔板层数 4第二部分 结构设计塔顶实际气液相体积流量 12塔板间距HT的选择 13确定液泛的动能参数 13计算液泛速度UF（Umax） 14空塔气速UG 14确定溢流方式 14根据VG求D 14计算圆整后实际气速 14确定溢流堰高度hw及堰上液层高度how 15板面筛孔位置设计 15水力学性能参数的计算、校核 16负荷性能(xngnng)图及操作性能评定 17筛板塔工艺(gngy)设计计算结果总表 18第三(d sn)部分 结束语结束语 1

2、9甲苯二甲苯连续精馏筛板塔的设计第一部分 工艺设计物料衡算原料 甲苯 （M=92kg/kmol） 二甲苯 （M=106kg/kmol）F=12500kg/h 将F换成kmol/hF=125000.45/92+12500(1-0.45)/106=126.00kmol/h馏出液中低沸点组分的含量不低于0.952XF = 0.45/（0.45/92+0.55/106）=0.485XD =0.952/920.952/92+（1-0.952）/106=0.9581D XD/F XF =0.962 D =0.962126.000.4852/0.9581=61.38kmol/hW =FD =126.0061

3、.38=64.62F XF = D XD+WXWXW =（F XFD XD）/W=（126.000.485261.380.9581）/64.62=0.036塔顶温度、塔底温度及Rmin1、确定操作压力P顶 =760mmHgP底 =760+28100/13.6=965.882 mmHg2、计算(j sun)塔顶温度td （露点(ldin)） 设td =112P0A =AiBi/(Ci+td)AA=6.953 BA=1344 CA=219,4AB=7,000 BB=1463 CB=214.7lgP0A =AABA/(CA+td)= 6.9531344/（112+219.4）P0A =789.73m

4、mHgKA = P0A/P顶=789.73/760=1.039lgP0B =ABBB/(CB+td)= 7.0001463/（112+214.7）同理，P0B = 332.57mmHg KB=0.4376XA=yA/ KA 其中(qzhng)yA = XDXA=yA/ KA =0.9581/1.039=0.9221XB = yB/ KB 其中yB =1yA =10.9581=0.0419XB = yB/ KB =0.0419/0.4376=0.0957Xi1=XA+ XB1=0.9221+0.09571=0.0178（0.0004） 设td =112.7lgP0A =AABA/(CA+td)=

5、 6.9531344/（112.7+219.4）P0A =805.43mmHgKA = P0A/P顶=1.060lgP0B =ABBB/(CB+td)= 7.0001463/（112.7+214.7）同理，P0B = 339.99mmHg KB=0.4473XA=yA/ KA 其中(qzhng)yA = XDXA=yA/ KA =0.9039XB = yB/ KB 其中(qzhng)yB =1yA =10.9581=0.0419XB = yB/ KB =0.0937Xi1=XA+ XB1=0.9039+0.09371=0.024（0.0004） 设td =112.6lgP0A =AABA/(C

6、A+td)= 6.9531344/（112.6+219.4）P0A =803.12mmHgKA = P0A/P顶=1.057lgP0B =ABBB/(CB+td)= 7.0001463/（112.6+214.7）同理，P0B = 338.92mmHg KB=0.4459XA=yA/ KA 其中(qzhng)yA = XDXA=yA/ KA =0.9064XB = yB/ KB 其中yB =1yA =10.9581=0.0419XB = yB/ KB =0.09396Xi1=XA+ XB1=0.9064+0.093961=0.00036（0.0004）顶= P0A /P0B =803.12/33

7、8.92=2.3696t顶 =112.63、塔底温度tb （泡点） 设tb =145.5P0A =AiBi/(Ci+tb)AA=6.953 BA=1344 CA=219.4AB=7.000 BB=1463 CB=214.7lgP0A =AABA/(CA+tb)= 6.9531344/（145.5+219.4）lgP0B =ABBB/(CB+tb)= 7.0001463/（145.5+214.7）P0A =1861.23mmHg KA = P0A/P=1861.23/965.882=1.927同理，P0B =867.696 KB=0.898yA= XA KA 其中(qzhng)XA = XWyA

8、 = XA KA = KA XW =1.9270.036=0.069yB = XB KB 其中(qzhng)XB =1XW =10.036=0.964yB = XB KB =0.9640.898=0.8657yi1=yA+ yB1=0.069+0.9641=0.0653（0.0004） 设tb =149P0A =2017.4mmHg KA =2.0886同理，P0B =949.41 KB=0.9829yA = 0.075 yB = 0.9475yi1=yA+ yB1=0.075+0.94751=0.0225（0.00004） 设tb =148P0A =1971.79mmHg KA =2.041

9、4同理，P0B =925.47 KB=0.9582yA = 0.073 yB = 0.9236yi1=yA+ yB1=0.073+0.92361=0.0033（0.0004） 设tb =148.1P0A =1976.32mmHg KA =2.0461同理，P0B =927.84 KB=0.9606yA = 0.0737 yB = 0.9260yi1=yA+ yB1=0.0737+0.92601=0.00026（0.0004）底= P0A /P0B =1976.32/927.84=2.1300t底 =148.1 =（顶 底 ）1/2=（2.3696 2.1030）1/2 =2.247 4.求Rm

10、inq=1Xe= XF =0.4852ye =Xe/1+（1）Xe =2.2470.4852/1+（2.2471）0.4852=0.6793Rmin =（XDye）/（yeXe）=（0.95810.6793）/（0.67930.4852）=1.4364三、确定最佳操作回流(hu li)比及塔板层数R=（1.1，1.3，1.5，1.7，1.9）Rmin采用(ciyng)逐板法计算 R=（1.2，1.4，1.6，1.8，2.0）Rmin采用捷算法(sun f)计算逐板法计算 R=1.1Rmin =1.11.4364=1.580精馏段：Xn =yn/（1）yn = yn /2.247（2.2471）

11、yn Yn+1 =XnR/（R+1）+ XD/（R+1）=0.6124 Xn +0.3713 X1=0.9150 y2=0.9289 X2 =0.85326 y3 =0.8938 X3 =0.3793 y4 =0.7236 X4 =0.7124 y5 =0.8144 X5 =0.66137 y6 =0.7763 X6 =0.6070 y7 =0.7430 X7 =0.5627 y8 =0.7159 X8 =0.5286 y9 =0.6950 X9 =0.5035 y10 =0.6797 X10 =0.4856 y11=0.6687 X11 =0.4732XF （0.4852）所以此操作(coz

12、u)回流比下精馏段理论塔板数为10（块）提馏段：Ym+1 =（R+qFD）Xn/（R+1）(1q）FD(FD 1) XW/（R+1） (1q）FD=1.4081 Xn0.01469 y12 =0.6516 X12 =0.4543 y13 =0.6249 X13 =0.4258 y14 =0.5849 X14 =0.3854 y15 =0.5280 X15 =0.3324y16 =0.4534 X16 =0.2696 y17 =0.3649 X17 =0.2036 y18 =0.2721 X18 =0.1426 y19 =0.1861 X19 =0.0924 y20 =0.1154 X20 =0

13、.0548 y21 =0.0625 X21XW （0.036） 此操作回流(hu li)比下提馏段理论塔板数为10（块）全塔理论(lln)塔板数NT =20（块） R=1.3Rmin 时，精馏段：X1 =0.9105 y2 =0.9217 X2 =0.8499 y3 =0.8877 X3 =0.7786 y4 =0.8412 X4 =0.7022 y5 = 0.7951 X5 =0.6281 y6 =0.7432 X6 =0.5629 y7 =0.7008 X7 = 0.51038 y8 =0.6665 X8 =0.47081 XF （0.4852）提馏段：Y9 =0.6305 X9 =0.4

14、316 y10 =0.5768 X10 =0.3776 y11 =0.5031 X11 =0.3106 y12 =0.4115 X12 =0.2373 y13 =0.3113 X13 =0.1674 Y14 =0.2157 X14 =0.1090 y15 =0.1359 X15 =0.0654 y16 =0.0762 X16 XW （0.036） R=1.5Rmin 时，精馏段：X1 =0.9105 y2 =0.9256 X2 =0.8469 y3 =0.8821 X3 =0.7692 y4 =0.8291 X4 =0.6833 y5 =0.7704 X5 =0.5900 y6 =0.7128

15、 X6 =0.5249 y7 =0.6621 X7 =0.4659 XF（0.4852）提馏段：Y8 =0.6093 X8 =0.4098 y9 =0.5345 X9 =0.3382 Y10 =0.4390 X10 =0.2583 y11 =0.3325 X11 =0.1815 Y12 =0.2301 X12 =0.1174 y13 =0.1445 X13 =0.0699 Y14 =0.0813 X14 =0.0378 y15 =0.03851 X15XW （0.036） R=1.7Rmin 时，精馏段：X1 =0.9105 y2 =0.9244 X2 =0.8448 y3 =0.8777 X

16、3 =0.7617 y4 =0.8188 X4 =0.6679 y5 =0.7522 X5 =0.5748 y6 =0.6862 X6 =0.4932 y7 =0.6283 X7 =0.42933 XF（0.4852）提馏段：Y8 =0.5496 X8 =0.3519 y9 =0.4486 X9 =0.2658 Y10 =0.336 X10 =0.1839 y11 =0.2292 X11 =0.1168 Y12 =0.1416 X12 =0.0684 y13 =0.0783 X13 =0.0364 Y14 =0.0365 X14XW （0.036） R=1.9Rmin 时，精馏段：X1 =0.

17、9105 y2 =0.9232 X2 =0.8427 y3 =0.8736 X3 =0.7548 y4 =0.8093 X4 =0.6538 y5 =0.7355 X5 =0.5530 y6 =0.6426 X6 =0.46535XF （0.4852）提馏段Y7 =0.5865 X7 =0.3869Y8 =0.4860 X8 =0.2961 y9 =0.3695 X9 =0.2069 Y10 =0.2551 X10 =0.1322 y11 =0.1594 X11 =0.07783 Y12 =0.0896 X12 =0.0419 y13 =0.0436 X13XW （0.036）捷算法(sun

18、f)计算 R=1.2Rmin=1.7237Nmin=lg(XD/1-XD)/(XD/1-XD)/lg= 7.9265X=(R-Rmin )/(R+1)=0.1055Y=0.75(1-X0.5668)=0.5404因为(yn wi) Y=(N- Nmin)/(N+1) 所以(suy) N=(Y+ Nmin)/(1-Y)=18.42) (包括釜) R=1.42Rmin=2.0110X=0.1908 Y=0.4567 N=15.43(包括釜) R=1.6Rmin=2.2982X=0.2613 Y=0.3995 N=13.86(包括釜) R=1.8Rmin=2.5855X=0.3205 Y=0.356

19、5 N=12.87(包括(boku)釜) R=2.0Rmin=2.8728X=0.3709 Y=0.3225 N=12.17(包括(boku)釜)回流(hu li)比R为1.12.0倍Rmin，步长为0.1Rmin时各塔段及全塔理论塔板数如下表：R为n倍Rmin全塔理论塔板数NTR为n倍Rmin全塔理论塔板数NT1.1201.6121.2171.7131.3151.8111.4141.9121.5142.011最佳操作回流比R=2.01196 最佳理论塔板数NT =14（块）塔板效率t=(td+tb)/2=(112.6+146.63)/2=129.62 甲苯 =20+（t20）/t=0.586

20、+-0.0035（129.6220）=0.2023 二甲苯=20+（t20）/t=0.687+-0.0042（129.6220）=0.2266AV =xiLi = XFL甲苯(ji bn)+ XFL二甲苯 =0.48520.2023+0.22660.5148=0.2148E=0.563-0.276LogaAV +0.0815（ LogaAV）2=0.6245N= N/ 1.1E =14/0.7240=20.37 圆整为21块第二(d r)部分 结构设计塔精馏(jn li)段第一块塔板的设计塔顶实际气液相体积流量=20+（td20）/t对液相来说：L二甲苯=20+（td20）/t=864+-0.

21、875（112.620）=782.975 Kg/m3L甲苯=20+（td20）/t=869+-0.978（112.620）=778.437 Kg/m3L=xiL i=L甲苯 X1+L二甲苯（1X1）=778.4370.9105+782.975（10.9105）=781.25 Kg/m3ML=xi Mi= M甲苯X1+M 二甲苯（1X1）=920.9105+106（10.9105）=93.2554对气相来说：G =PMG/RT =Pyi Mi/RT =101325XDM甲苯+（1XD）M二甲苯/8.314（273.15+td）=1013250.958192+（1-0.9581）106/8.314

22、（273.15+112.6）=2.9251 Kg/m3VG =（R+1）DMG/G=（2.0110+1）61.3892.5866/2.9251=5849.85VL =RDML/L=2.011061.3893.2554/781.25=14.734塔板间距HT的选择HT =0.45m 三、确定液汽的动能(dngnng)参数VL/ VG=0.0412查表 C20=0.084=20+（t20）/t二甲苯=20+（t20）/t=28.99+（-0.109）（112.620）=18.8966甲苯(ji bn)=20+（t20）/t=28.53+（-0.113）（112.620）=18.0662=xi i=

23、甲苯(ji bn)XD+二甲苯（1XD）=18.06620.4852+18.8966（10.4852）=18.4937C= C20（/20）0.2=0.084（18.4937/20）0.2 =0.0836四、计算液泛速度UF（Umax）UF =C=0.0836（781.25-2.9251/2.9251）0.5=1.37 m/s 五、空塔气速UG =0.7UF =0.71.37=0.959 m/s六、确定溢流方式LW/D =0.7Ad/A=0.088Wd/D=0.14七、根据VG求DAG =VG/ UG =5849.85/0.9593600=1.694AG =A（1Ad/A）A=1.857D=（

24、4A/）0.5=（42.1708/3.14）0.5=1.54m圆整后D=1.6m八、计算(j sun)圆整后实际气速A=D2/4=3.141.62/4=2.01m2AG = A（1Ad/A）=2.01（10.088）=21.83UG = VG/ AG =5849.85/1.833600=0.8879UG/ UF =0.8879/1.37=0.648lW =0.7D=0.71.6=1.12mWd =0.14D=0.141.6=0.224mAd =0.088A =0.1634 m2九、确定溢流(y li)堰高度hw和堰上液层高度(god)how选hw =0.05m VL/ lW2.5=1.734/

25、1.122.5=13.16EW =1.032how =0.0028EW（VL/ lW）2/3=0.00281.032（14.734/1.12）2/3=0.016mhw + how =0.05+0.016=0.066m=66mm 十、板面筛孔位置设计1、板面筛孔孔径 do =5mm 中心距 t / do =3 板厚 tp =3.5mm2、计算开孔区面积AaAa =A2 AdAa =1.85720.1634=1.530 m23、求开孔率= A0/ Aa =0.907（do / t）2=0.907（1/3）2=0.1014、计算(j sun)塔板开孔面积A0=Aa =0.1011.530=0.154

26、6 5、孔速U0 = VG/ A0=5849.85/0.15463600=10.511 m/s6、孔数 N= A0/（do 2/4）=0.1546/（3.140.0052）/4=7878（个）十一(ShY)、水力学性能参数的计算、校核1、液沫夹带分率(fn l)的校核EG =0.057UG/HT2.5（hw + how）/ =0.0570.8879/（0.452.59(0.05 +0.016）/18.4937=0.009810% 2、塔板压降干板压降h0 =（U0/C0）2（G/L）/2g=（10.5107/0.8）2（2.9251/781.25）/29.8=0.0329m液体静压降He =（

27、hw + how）=0.590.066=0.0389m表面压力降h=410-3/gL do=410-318.4937/（9.8781.250.005）=0.0019m单板压降 h= h0+ he=0.0329+0.0389=0.0718m3、液面落差 h0/2 忽略4、塔板漏液情况校验产生漏液的干板压降h0h0=0.0056+0.13（hw + how）- h0=0.0056+0.130.066-0.0019=0.0123工作状态下K= （h0/ h0）0.5=（0.0329/0.0123）0.5=1.63681.55、降液管液泛情况(qngkung)校验选取(xunq)降液管下缘到下层塔板距

28、离 20mmAda=0.02lW =0.021.12=0.0224m2 液体(yt)流出降液管的阻力损失hda=1.39（VL/3600 Ada）2/g=1.39（14.734/36000.0224）2/9.8=0.0047计算液层高度Hd，泡沫层高度HdHd=Ht+ hw + how+ hda =0.0718+0.05+0.016+0.004730=0.1425Hd= Hd/=0.1425/0.5=0.285Hd (HT + hw) =0.285(0.5+0.05)=0.5681符合 液体在降液管中停留时间的校验=3600 Hd Ad / VL =36000.14250.1634/14.73

29、4=5.69 s 3 s十二、负荷性能图及操作性能评定负荷性能图漏液线漏液点的干板压降为：H10=0.0056+0.13(hw+how)- h hw=0.05 h= 0.0019最大气相负荷线（最大允许液沫夹带线） how = 0.0028 EW (VL/ LW)2/3= 0.00281.032(VL /1.12)2/3= 0.579(VL )2/3H10=0.00560.13(0.050.596VL 2/3)-0.0019=0.01020.0775(VL )2/3干板压力降的表示式h0 =（U0/C0）2（G/L）/2g=0.0125VG2得漏液点VG和VL的关系VG=（0.8166.2(V

30、L )2/3）1/2VL m3/s00.0020.0040.0060.008VG m3/s0.90330.95520.98461.00861.0296绘出漏液(lu y)线如图中的线液体(yt)流量下限线how = 0.596 EW (VL)2/3 VL =0.0010VL=1200 Ad Hd=12000.19980.3112=74.6133绘出液体(yt)流量如图中的线液体流量上限线停留时间 = Hd Ad / VL=0.14250.1634/ VL = 3 VL =0.0077 绘出液体流量上限线降液管液泛线 Hd= Hd/=HT+hw(Ht+ hw + how+ had) /= HT+

31、hw HT =0.45 hw=0.05 =0 how = 0.596 (VL )2/3 hda=1.39（VL/0.0224 ）2/g= 282.68 (VL)2 h= h0+ he h0=0.0125（VG）2 He =（hw + how）=0.03+0.3516(VL )2/3 把代入所以VG = （13.6-75.808 (VL )2/3- 22614.4(VL )2 )1/2VL m3/s0.0020.0040.0060.008VG m3/s3.51153.37093.21333.0280绘出液泛线 雾沫夹带上限线 Eg=0.0057/(u/ HT-2.5（hw + how） )3.20.1=0.005