浙科化工分离13级习题 下载本文

SlnP1?16.0826?40504050lnP2S?16.3526?350;350

?

P1S=91.0284;P2S=119.2439

因为在恒沸点

S?1P?1P2S1 由?12? ?1得 ??2P1S?2P2SS?1P221ln?lnS?ln?1?ln?2?A(x2?x1)?A(1?2x1)?P2?2

ln91.0284?0.3009(1?2x1)119.2439

?x1=0.9487 x2=0.0513

2ln?2?0.3009?0.9487

2?ln?1?0.3009?0.0513

?1=1.0008 ?2=1.3110

S?xP?iiiP==1.0008?0.9487?91.0284+1.3110?0.0513?119.2439=95.0692

?99.75

设T为340K

则A=1.7884-4.25?10-3?340=0.3434

SlnP1?16.0826?40504050lnP2S?16.3526?340;340

?

P1S=64.7695;P2S=84.8458

lnSP1lnS?A(1?2x1)P2

64.7695?0.3434(1?2x1)84.8458

?x1=0.8931 x2=1-0.8931=0.1069

22?ln?1?0.3434?0.1069 ln?2?0.3434?0.8931

?1=1.0039

S?2=1.3151

P=??ixiPi=1.0039?0.8931?64.7695+1.3151?0.1069?84.8458=69.9992

?99.75

设T为352K

则A=1.7884-4.25?10-3?352=0.2924

SlnP1?16.0826?40504050;lnP2S?16.3526? 352352?

P1S=97.2143;P2S=127.3473

SP1由lnS?A(1?2x1)

P2ln97.2143?0.2924(1?2x1)

127.3473?x1=0.9617

x2=1-0.9617=0.0383

?ln?1?0.2924?0.03832 ln?2?0.2924?0.96172

?1=1.0004

?2=1.3105

P=??ixiPiS=1.0004?0.9617?97.2143+1.3105?0.0383?127.3473=99.9202

?99.75

8. 在101.3Kpa压力下氯仿a.-甲醇b.系统的NRTL参数为: ?12=8.9665J/mol,

?12=-0.83665J/mol,?12=0.3。试确定共沸温度和共沸组成。

安托尼方程(PS:Pa;T:K)

S2696.79氯仿:lnP 1?20.8660?(T?46.16)甲醇:lnP2S?23.4803?3626.55 (T?34.29)则lnP1S?20.8660?2696.79 (326.65?46.16).55 lnP2S?23.4803?3626(326.65?34.29)解:设T为53.5℃

P1S=76990.1 P2S=64595.6

(??ij?ij)由Gij?exp,?ij=?ji

G12?exp(??12?12)exp(?0.3?8.9665)==0.06788

G21?exp(??21?21)(0.3?0.8365)=exp=1.2852

2ln?1?x2???12G12?22?(x?xG)(x?xG)?1221?2112???2?21G21=

8.9665?0.06788?(1?x1)??22?[x?(1?x)?1.2852]([1?x)?0.06788x]?211??1?=

)?1.285222?(?0.8365??1.38170.60862?(1?x1)??22?(1.2852?0.2852x)(1?0.93212x)?11???

ln?2?2x1?

2?x1??21G21??22?(x?xG)(x?xG)?1221??2112??2?12G12=

28.9665?0.06788?0.8365?1.2852??22?(1?x?0.06788x)[x?1.2852(1?x)]??1111??=

?0.04131?1.075072?x1??22?(1?0.93212x)(1.2852?0.2852x)?11???

lnP1SP2Sln?1ln?2-==

ln76990.164595.6=0.1755

求得x1=0.32 ?1=1.2092 ?2=0.8971

?xiPiS?i?x1P1S?1?x2P2S?2=0.32?76990.1?1.2092?0.68?64595.6?0.8971 =69195.98Pa?101.3kPa 设T为60℃

S2696.79lnP1?20.8660?(333.15?46.16)则

.55lnP2S?23.4803?3626(333.15?34.29)

P1S=95721.9 P2S=84599.9

ln?1ln?2lnP1SP2S-==

ln95721.984599.9=0.1235

设T为56℃

则lnP1S?20.8660?2696.79 (329.15?46.16).55lnP2S?23.4803?3626(329.15?34.29) P1S=83815.2 P2S=71759.3

lnP1SP2Sln?1ln?2-==

ln83815.271759.3=0.1553

求的当ln?1-ln?2=0.1553时求得x1=0.30 ?1=1.1099 ?2=0.9500

?xiPiS?i?x1P1S?1?x2P2S?2=0.30?83815.2?1.1099?0.70?71759.3?0.9500 =75627.8Pa?101.3kPa

9. 在转盘塔中有机溶剂萃取烃类混合物中的芳烃。原料处理量100吨/天,溶剂:进料=5:1(质量)。取溶剂相为连续相。有关物性数据为

溶剂 ?c=1200Kg/m3, ?c?1.0?10?3Pa?s

烃 ?d?750Kg/m3 ?d?0.4?10?3Pa?s ?=5.924?10?3N/m 转盘塔转速n=0.5s?1。结构尺寸的比例为:DS/D?0.7 ,DR/D?0.6,

HT/D?0.1。试计算所需塔径。

解:为计算塔径。必先求特性速度uk,而uk的计算式中含由特定的塔径,故应试差。 假设 D=2.1m

则DS?D(DS/D)?1.47m,DR=1.26m, HT=0.21m 由式(5-30)得

?31200?7550.99.811.01.472.30.210.91.262.65.924?10uk?0.012()()()()()()=0.069/s 12001.261.262.11.26?0.521.0?10?3Vd?Vc?1000?1.543?10?2m3/s0.75?86400 5?1000?4.823?10?2m3/s1.2?86400

ud/uc?0.32

由式(5-35)

?dF(0.322?8?032)0.5?3?0.32??0.254(1?0.32)

由式(5-33)

ucF?0.069(1?2?0.25)(1?0.25)2?0.0194m/s

设计速度取液泛速度的75%

uc?0.75?0.0194?0.01455m/s

由式(5-39)

D?4?4.823?10?2?2.05m3.1416?0.01455

由于D=2.05可直接圆整成2.1m,故不再继续试差。

10. 乙醇-苯-水系统在101.3kPa,64.86℃形成恒沸物,其组成为22.8mol%乙醇a.,53.9mol%苯b.和23.3mol%水c.,利用恒沸点气相平衡组成与液相组成相等这样有利条件,计算在64.86℃等温分离该恒沸混合液成为三个纯液体产物所需的最小功。

解:在等温等压条件下,将其分离成纯组分时所需最小功为

?Wmin,T??RT?nF?xFiln?FixFi

设为理想溶液,?Fi?1,若nF?1kmol