2
??????323600????2×0.0123)=0.0442()=0.54????23
1.0223
2
?????=0.0442(
????
???=2.5???=2.5×(???+?????)=2.5×(0.059+0.54????2
?6
)=0.15+1.35????2
3.2
23
5.7×10????=(1.11×
55.9×0.001????2
(0.45?(0.15+1.35????2
232))3)=0.1
整理得:????2=2.33?(10.47????2
)
(2)液相负荷下限
对平直堰,取堰上液层高度how=0.006m作为最小液体负荷标准。
22.84
=??()=0.54????23=0.006 1000????
2????3?????
取E=1,则:
?????=0.0442(
???????
)=0.006 ????
23??????????=1.7???07??3╱??
(3)液相负荷上限
液体的最大流量应保证降液管中停留时间不低于3-5s。 液体降液管内停留时间
??????????==3?5??
????
以θ=5s作为液体在降液管内停留时间的下限,则:
??????????
????????0.2261×0.45===0.02035??3╱??
??528
(4)漏液线
由??0??????=4.4??0√(0.0056+0.13×(???+?????)????)×(
2.84=??() 1000????
2????3??????????????)= ??????0
?????
⑴精馏段:
????12.84
????1??????=4.4??0??0√(0.0056+0.13×(???1+??())????1)×()
1000????????1
2
2
????32.84????13816.66
=4.4×0.5×0.164√(0.0056+0.13×(0.064+×1(3600×))?0.0044)×()
10001.021.02即????1??????
⑵提馏段:
=0.36×√7.62+68.52??
2
??13
????2??????=4.4??0??0√(0.0056+0.13×(???2+
??2.84
??())????2)×(??2) 1000????????2
2
32????3=4.4×0.5×0.164√(0.0056+0.13×(0.059+
2.84????2931.46
×1(3600×))?0.0061)×() 10001.020.752
??23
即????2??????
=0.36×√8.9+106.29??
(5)液泛线
????=??(????+???)=???+???+???=???+?1+???+???+???
?1=????? ????=???+?????
29
联立解得:??????+(??????1)×(???)=(??+1)×(?????)+???+???+???
忽略hσ,将how与Ls,hd与Ls,hc与Vs的关系式代入,并整理得:
??????=??????????
⑴精馏段:
22
2
??????3
0.051????10.0511.02??1===0.0095
(??0??0)2????1(0.164×0.5)2816.66??1=??????+(??????1)×(???1)=0.5×0.45+(0.5?0.564?1)×0.064=0.157
0.1530.153??1===1815.541
(?????0)2(1.02×0.009)2??1=2.84×10?3??(1+??)(
36003600
)=2.84×10?3×1(1+0.564)()=1.03 ????1.022
323将有关数据代入整理得:????12=16.53?191109.58????12?108.42????1?
⑵提馏段:
??2=
0.051????20.0510.75
==0.0061
(??0??0)2????2(0.164×0.5)2931.46??2=??????+(??????1)×(???2)=0.5×0.45+(0.5?0.573?1)×0.059=0.162
??2=
0.1530.153
==277.994
(?????0)2(1.02×0.023)2232336003600?3)=2.84×10×1(1+0.573)()=1.036 ??2=2.84×10??(1+??)(????1.02
?3
整理得:????22=26.56?45572.79????22?169.84????2?
在操作范围内任意取两个Ls值算出Vs。
30
由以上1-5作出塔板负荷性能
图4-5精馏段塔板负荷性能图
图4-6提馏段塔板负荷性能图
由塔板负荷性能图可以看出:
31
①在任务规定的气、液负荷下的操作点P(设计点)处在适宜操作区内的适中位置; ②塔板的气相负荷上限完全由雾沫夹带控制,操作下限由漏液控制; ③按固定的液气比,由图可查出塔板的气相负荷上限
Vs1max=3.54(m3╱s),Vs2max=3.57(m3╱s),气相负荷下限Vs1min=0.9939(m3╱s),Vs2min=1.0742(m3╱s)
精馏段操作弹性:
提馏段操作弹性:
故设计基本合理。
????1=??1??????????1??????=3.54
0.9939=3.56
????2=??2??????????2??????=3.571.0742=3.32
32