(3)操作压力
塔顶操作压力:
????=101.3+??=101.3+0=101.3??????
每层塔板压降:△p=0.7kPa 进料板压力:
????=????+????????=101.3+0.7×10=108.3??????
精馏段平均压力:
????=(????+????)×0.5=(101.3+108.3)×0.5=104.8??????
塔底板压力:
????=????+????????=101.3+0.7×29=121.6??????
提馏段平均压力:
??′??=(????+????)×0.5=(121.6+108.3)×0.5=114.95??????
(4)气液相体积流量计算
精馏段:L=140.428kmol╱h V=219.498kmol╱h
已知:????1=24.865????╱????????;????1=28.859????╱????????
????1=816.66????╱?;????1=1.02????╱╱
精馏段质量流量:
??1=??????1=140.428×24.865=3491.742????╱? ??1=??????1=219.498×28.859=6334.493????╱?
精馏段体积流量:
????1=????1
??13491.742
==0.00119?╱??
????1×3600816.66×3600??16334.493===1.72508?╱?? ????1×36001.02×360013
提馏段:L’=542.418kmol╱h V’=219.498kmol╱h
已知:????2=18.895????╱????????;????2=22.406????╱????????
????2=931.46????╱?;????2=0.75????╱╱
提馏段质量流量:
??2=??????2=542.418×18.895=10248.988????╱? ??2=??????2=219.498×22.406=4918.072????╱?
提馏段体积流量:
????2=
??210248.988
==0.00306?╱??
????2×3600931.46×3600??24918.072
==1.82151?╱??
????2×36000.75×3600
????2=
14
第四章 精馏塔主要工艺尺寸的设计计算
4.1精馏塔塔体工艺尺寸计算
(1)塔径计算
精馏段:
由u=(安全系数)×umax,安全系数=0.6~0.8
????????
求取史密斯关联图的横坐标:
?????????
=??√
????
0.5
????1????10.00119816.660.5
??1=()=()=0.02
????1????11.725081.02
图4-1史密斯关联图
设板间距:HT=0.45m,板上清液高度:hL=0.07m 所以液体沉降高度:
15
?=?????????=0.45?0.07=0.38??
于是查图可知道:C20=0.0802
??10.235.34
??1=??201()=0.0802()
2020????????1
0.2
=0.0899
????1?????1816.66?1.02
√=??1√=0.0899×=2.542
????11.02取安全系数K=0.65
??1=??????????=0.65×2.542=1.6523 ??1=√
圆整到D1=1.2m
4????14×1.72508
√==1.153??
????13.14×1.6523????1=
空塔气速:
??23.14??1=×1.22=1.1304╱ 44??′1=
提馏段:
????11.72508
==1.526??╱?? ????11.1304求取史密斯关联图的横坐标:
0.5
????2????20.00306931.460.5
??2=()=()=0.059
????2????21.821510.75设板间距:HT=0.45m,板上清液高度:hL=0.07m 所以液体沉降高度:
?=?????????=0.45?0.07=0.38??
于是查图可知道:C20=0.0789
??20.255.9??2=??202()=0.0789()2020????????2
0.2
=0.0969
????2?????2931.46?0.75
√=??2√=0.0969×=3.414
????20.7516
取安全系数K=0.65
??2=??????????=0.65×3.414=2.2191 ??2=√
圆整到D2=1.2m
4????24×1.82151
=√=1.023?? ????23.14×2.2191????2
空塔气速
??23.14=??2=×1.22=1.1304╱ 44????21.82151??′2===1.611??╱??
????21.1304(2)精馏塔有效高度计算
精馏段有效高度:
??╱=(????╱?1)×(????)=(9?1)×0.45=3.6??
提馏段有效高度:
??╱=(????╱?1)×(????)=(20?1)×0.45=8.55??
在进料板上方开一人孔,其高度为0.8m,故精馏塔的有效高度为:
??=??1+??2+0.8=3.6+8.55+0.8=12.95??
4.2塔板主要工艺尺寸计算
(1)溢流装置的计算
本设计采用单溢流弓形降液管,凹形受液盘 堰长取
????=0.85??=0.85×1.2=1.02?? ╱╱╱╱╱╱╱╱╱╱╱╱╱╱╱?????=0.0442(???
???
) ????
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