甲苯-乙苯的精馏工艺设计
八、塔板负荷性能图
(一)、精馏段塔板负荷性能图 1、液相负荷上限线 Ls,max1?HTAf1??0.5?0.07065?0.007065 m3/s ① 5 2、液相负荷下限线
取平堰堰上液层高度how?0.006m,E?1.031。
?3600Ls,min1?? how1?0.00284E1???lw1??2/3?3600Ls,min1???0.00284?1.031????0.7??2/3?0.006
Ls,min1?5.7037?10?4 m3/s ② 3、雾沫夹带线
5.7?10?6?ua1?ev1???LM1??HT?hf1?3.2
式中ua1?Vs1Vs1??1.39987Vs1
AT?Af10.785?0.07065hf1?2.5hL1?2.5?hw1?how1? E?1.031
2/3??3600Ls1????2.5?0.0442?0.00284E??l???w1?????/3?2.50.0442?0.8724L2S1
??/3?0.1105?2.181L2S1??1.39987Vs15.7?10?6?代入数据得ev1??/3?18.1241?10?3?0.5?0.1105?2.181L2s1?/3简化得:Vs1?1.6843?9.4311L2s1
3.2?0.1
在操作范围内,任取几个Ls值,依上式算出对应的Vs值列于下表:
Ls,m3/s×10Vs,m3/s 4 5.704 1.62 20.1677 34.6317 49.0957 70.65 1.53 1.47 1.41 1.34
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甲苯-乙苯的精馏工艺设计
依据表中数据作出雾沫夹带线 ③ 4、液泛线
??HT?hw1??hp1?hw1?how1?hd1 how1?3600Ls1???0.00284E1??l?w1??22/3?3600Ls1??0.00284?1.031???0.7??22/3/3?0.8724L2s1
1?uo1???hc1??2g?Co1???Vs1???Vm1?????0.051????CA???Lm1??o1o1?2??Vm1???????Lm1?
Vs1???3.2508??0.051?????0.8011?0.05395??773.2563??0.1148Vs21/3hl1???hw1?how1??0.60?0.0442?0.8724L2s1/3?0.0265?0.52344L2s1
??
h?1?0.0019114 m
2/3hp1?hc1?hl1?h?1?0.1148Vs2?0.52344L1s1?0.0265?0.0019114
?Ls1?Ls1??2?hd1?0.153??0.153?256.945L??s1 ?lh??0.7?0.03486??w1o1?2/30.5?0.5?0.0442??0.1148Vs21?0.52344Ls1?0.0284114?0.0442/32?0.8724L2?256.945Ls1s12/32Vs21?1.7377?12.15889Ls1?2238.1969Ls1
22??
在操作范围内,任取几个Ls值,依上式算出对应的Vs值列于下表:
Ls,m3/s×10Vs,m3/s 4 5.704 20.1677 34.6317 49.0957 1.29 1.24 1.20 1.15 70.65 1.09 依据表中数据作出液泛线 ④ 5、漏液线(气相负荷下限线)
/3hL?hw1?how1?0.0442?0.8724L2s1
漏液点气速
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甲苯-乙苯的精馏工艺设计
uOM1?4.4C0(0.0056?0.13hL?h?1)?Lm1?Vm1 ?4.4?0.8011?0.0056?0.13?(0.0442?0.8724Ls1)?0.0019114??2/3?773.25633.2508 Vs,min1?Ao1uom1,整理得:
2/3 Vs2,min1?0.97556Ls1?0.081156
在操作范围内,任取几个Ls值,依上式算出对应的Vs,min值列于下表:
Ls,m3/s×104 5.704 0.296 20.1677 34.6317 49.0957 0.311 0.321 0.330 70.65 0.342 Vs了,min,m3/s 依据表中数据作出漏液线 ⑤ 6、操作弹性
操作气液比 Vs1/Ls1?0.6708/0.00244?274.92
操作弹性定义为操作线与界限曲线交点的气相最大负荷Vs1,max与气相允许最小负荷Vs1,min之比,即:
操作弹性=
Vs1,maxVs1,min?1.17347?3.88
0.30246将所得上述五个方程绘制成精馏段塔板负荷性能图(如图6) (二)、提馏段塔板负荷性能图 1、液相负荷上限线 Ls,max2?HTAf2??0.5?0.07065?0.007065 m3/s ① 5 2、液相负荷下限线
取平堰堰上液层高度how?0.006m,E?1.031。
33
甲苯-乙苯的精馏工艺设计
?3600Ls,min2???0.00284E2???lw2??2/3how2?3600Ls,min2?? ?0.00284?1.081????0.7?? ?0.0062/3
Ls,min2?5.3126?10?4 m3/s ② 3、雾沫夹带线
5.7?10?6?ua2?ev2???LM2?H?hf2??T3.2
式中ua2?Vs2Vs2??1.39987Vs2
AT?Af20.785?0.07065hf2?2.5hL2?2.5?hw2?how2? E2?1.081
2/3??3600Ls2????2.5?0.0368?0.00284E2??l???w2?????/3?2.50.0368?0.9147L2S2
??/3?0.092?2.28676L2S2??1.39987Vs25.7?10?6?代入数据得ev2??/3?17.4532?10?3?0.5?0.092?2.28676L2s2?/3简化得:Vs2?1.7436?9.77255L2s2
3.2?0.1
在操作范围内,任取几个Ls值,依上式算出对应的Vs值列于下表:
Ls,m3/s×10Vs,m3/s 4 5.3126 19.8306 34.3486 48.8666 1.68 1.59 1.52 1.46 70.65 1.38 依据表中数据作出雾沫夹带线 ③ 4、液泛线
??HT?hw2??hp2?hw2?how2?hd2 how2?3600Ls2???0.00284E2??l?w2??2/3?3600Ls2??0.00284?1.081????0.7?2/3/3?0.9147L2s2
34
甲苯-乙苯的精馏工艺设计
1?uo2???hc2??2g?Co2??2??Vm2????Lm2?Vs2?????0.051??CA????o2o2?22??Vm2????Lm2????
Vs2???3.7023??0.051????0.8011?0.05395763.6458?????0.13237Vs22
/32/3 hl2???hw2?how2??0.60??0.0368?0.9147L2s2??0.02208?0.54882Ls2
h?2?0.001864 m
2/3hp2?hc2?hl2?h?2?0.13237Vs22?0.54882Ls2?0.02208?0.001864
hd2?Ls2?Ls2??2??0.153??0.153?374.889L??s2 ?lh?0.7?0.02886???w2o2?222/32/320.5?0.5?0.0368??0.13237Vs22?0.54882Ls2?0.023944?0.0368?0.9147Ls2?374.889Ls2/32 Vs22?1.5688?11.0563L2s2?2832.13Ls2
??在操作范围内,任取几个Ls值,依上式算出对应的Vs值列于下表:
Ls,m3/s×10Vs,m3/s 4 5.3126 1.22 19.8306 34.3486 48.8666 70.65 1.18 1.13 1.09 1.01 依据表中数据作出液泛线 ④ 5、漏液线(气相负荷下限线)
/3hL?hw2?how2?0.0368?0.9147L2s2
漏液点气速
uOM2?4.4C0(0.0056?0.13hL?h?2)?Lm2?Vm2 ?4.4?0.8011?0.0056?0.13?(0.0368?0.9147Ls2)?0.001864??2/3?763.64583.7023 Vs,min2?Ao2uom2,整理得:
2/3 Vs2,min2?0.88696Ls2?0.06355
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