2精馏塔的工艺计算

..”.”.2 精馏塔的工艺计算精馏塔的物料衡算根底数据〔一〕生产力量：10万吨/33024小时计时。〔二〕进料组成：212.6868Kmol/h3.5448Kmol/h10.6343Kmol/h。〔三〕分别要求：0.010.005。物料衡算〔清楚分割〕以甲苯为轻关键组分，乙苯为重关键组分，苯为非轻关键组分。x 0.01 x 0.005HK，D LK，W编号2.1组分进料和各组分条件f/kmol/hif/%i1苯3.54481.56252甲苯10.63434.68753乙苯212.686893.7500总计226.8659100由《分别工程》P653-23得：DF

LKzii1

x

〔2.1〕1x0.0156250.0468750.005

x,WD226.8659

10.010.005

13.2434Kmol/hW=F-D=226.8659-13.2434=213.6225Kmol/h2WX2，W213.62250.0051.0681Kmol/hd f 10.63431.06819.5662Kmol/h2 2 2d D 13.24340.010.132434Kmol/h3 X3，D f d 212.68680.132434212.5544Kmol/h3 3 3表2-2 物料衡算表编号 组分

f/kmol/hi

馏出液di

釜液i1苯3.54483.544802甲苯10.63439.56621.06813乙苯212.68680.1324212.5544总计226.865913.2434213.6225精馏塔工艺计算操作条件确实定一、塔顶温度纯物质饱和蒸气压关联式〔化工热力学P199：ln(PS/P)(1x)1(AxBx1.5Cx3Dx6)Cx1T/TC2-3物性参数组份相对分子质量临界温度TCPC苯78562.248.9甲苯92591.841.0乙苯106617.236.00.1MpaK名称 A B C D苯-6.982731.33213苯-6.982731.33213-2.62863-3.33399甲苯-7.286071.38091-2.83433-2.79168

1.45488

-3.37538

-2.23048

2-3汽压关联式数据x1T/TC

1318.15/562.20.434In(PS

P)(10.434)1C(6.982730.4341.332130.4341.52.628630.43433.333990.4346)5.1PSexp(5.1)48.90.29740.1MPaP0aP0b

0.09850.1MPan

yi 1，试差法求塔顶温度i1

p0 pitpatpa0pb0pc0等式左边等式右边80.085.0100105.51061.00801.17291.79612.07942.10670.38710.45870.73940.87120.88400.16720.20230.34170.40950.41612.18711.84881.52980.98040.96640.98690.98690.98690.98690.9869=105.5℃二、塔顶压力塔顶压力p顶

1.0130.1Mpa三、塔底温度ni1

p0xi

p 试差法求塔底温度等式左边0.34370.47510.85800.98411.0110等式右边1.01331.01331.01331.01331.0133tp10.73940.99221.6987tp10.73940.99221.69871.92491361.9728b0p0.34170.47260.85390.97951.0063c0塔底压力p底

1.0130.1Mpa五、进料温度p进

1.0130.1Mpa，ni1

p0x pi itptp11.79612.33573.77773.95211334.0415a0p0.73940.99221.69871.78661.8318b0p0.34170.47260.85390.90250.9276c0等式左边0.38310.52600.93920.99161.0186等式右边1.01331.01331.01331.01331.0133=133℃六、相对挥发度的计算据化学化工物性数据手册，用内插法求得各个数据t 105.5℃，顶

5.961 甲苯

2.514

1；乙苯t 136℃，底

1.96 乙苯

1；t 133℃，进

4.38 甲苯

1.97 1乙苯综上，各个组份挥发度见下表组份133105.5136平均相对挥发度苯4.385.9615.1705甲苯1.972.5141.962.148乙苯1111据清楚分割结果，计算最少平衡级数。x x 9.5612

212.5544xlg(( LKxN

)(HK) ) lg( LK D x W 1.0681LK

0.1324

)6.26min

lg

LKHK

lg2.148塔板数确实定Rmin本设计为泡点进料，即饱和液体进料，q=1由恩特伍德公式：

(x )i i,D mR 1i

minxx 1qix 5.17050.015625 2.1480.046875 10.9375iii

5.1705

2.148

1 0试差法求得2.3则最小回流比R

(x )i i，Dm

15.17050.26772.1480.722310.0111.304min

5.17052.3 2.1482.3 12.3i二、实际回流比1.2倍R=1.2Rmin=1.2×1.304=1.565三、全塔理论板数确实定RR 1.5651.304min 0.102R1 1.5651P331-28吉利兰图得NN

min0.52将N 6.26代入，求得N=15.2min四、进料板的计算

N2d d lg( ) ( ) (N ) m

f LKlg

f HK9.5LKHK(N)

lg(f) LK

(f

) HK3m lg

LKHK

(N ) NN N N15.2，Rm R由于 S R(N )Rm(N)

9.53

(N) NSm SN Sm N

15.211.12R (N ) 9.51 Rm 1(N) 3SmN NNS

15.211.124.0853 精馏塔主要尺寸的设计3.1塔径的计算填料精馏塔有关参数：R=2理论板数：N=16T进料板序号：N=5F塔顶温度：t=105.5℃D塔釜温度：t=136℃W塔顶有关参数计算[4 885kg/m3 866kg/m3由化工物性手册查得： 苯 甲苯 867kg/m3乙苯气体平均摩尔质量：M 0.268780.722920.0110688.39g/molV

PMV

1.01310588.39

2.85kg/m3V RTD

8.314103

105.5273液体密度： 0.2688850.7228660.01867871.102kg/m3L39.7388.39SV 36002.85S

0.342m3/sLRD213.243426.4868kmol/h进料板有关参数计算V V,S S

0.342m3/s气相组成： 2.94mx 2.940.005y1ax12.9410.005

0.014气体平均摩尔质量：M”0.014920.986106105.8g/molV

PM” V

1.013105105.8

3.71kg/m3V RTD

8.314103

133273.15”0.2687550.7227637710.01761kg/m3L精馏段塔径计算液相质量流量为： 26.486887.332313kg/hL气相质量流量为：V

39.788.393511.75kg/h 0.5 2313 2.85 0.5流淌参数为：LV

VL

3511.75871.102

0.0377由于填料选择的是金属孔板波浪填料350Y；u2

msx

V0.2

0.7g L 958.3水由于 0.262mPas 水L L

871.102

1.10 2.85L

0.0033 257

0.2620.2u2max

1.100.0033

0.7即：u 3.3m/smax

9.8由于u

=max

u u0.8u440.3423.142.64

max

0.83.32.64m/suuS

圆整后为0.6m3.3.5提溜段塔径计算”253.3567.4817096kg/hL气相质量流量为：” 39.7105.84200kg/hV”

”0.5 170963.710.5L VL V” ”

4200

0.28 V L

u”max

2””V

”0.2

0.4g ” LL由于257 ” 0.207mPasL 863 ”

3.71水”水

1.12

V 0.00488770 ”L

761

u”max

22571.120.004880.0002070.29.8

0.4即：u” 3.1m/smaxmaxu”0.8u” 0.83.12.48m/smax4Vu”S40.3423.144Vu”S40.3423.142.48比较精馏段与提溜段计算结果，二者根本一样。圆整塔径，取D=600mm液体喷淋密度及空塔气速核算精馏段液体喷淋密度为LLULL

74344.58m3/ 743D2

3.140.32 2 22VVV3511.75uD2

2.85 1.22m/s36003.140.622 2 提溜段液体喷淋密度为：170964200 170964200

0.62

33.3m3/m2h2 提溜段空塔气速为：u”

D2

V”V”42003.7136003.14V”V”42003.71

1.11m/s2 2 查规整填料性能参数知350m2/m3LW(min)

0.08m3/(m2h)则U L 0.0835028m3/(m2h)(min) W(min)600mm符合要求。填料层高度计算填料层高度计算承受理论板当量高度法。对350Y金属孔板波浪填料，由附录查每米填料理论板数为3.5～4块，nt

=3.