Page 162 - Distillation theory

P1: JPJ/FFX P2: FCH/FFX QC: FCH/FFX T1: FCH
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136 Distillation Trajectories and Conditions of Mixture Separability

2
x D
(K )
23
(K )
22
(K ) N +
x F 21 3
a)
+
x B N 2
+
N 1

(L/V) 1
(L/V) 2
(K )
21
(L/V) 3
1 x D 13 3
S 1 S 2 S 3
2

b)

+
N qsh

pinch
L ( V )
SN qsh
x D
1 3
13
Figure 5.18. The tangential pinch in rectifying section for the
acetone(1)-benzene(2)- chloroform(3) mixture for the split 1,3 : 2: (a)
(3)
sharp separation (the tangential-pinch region Reg tang not shaded), (b)
quasisharp separation. 1, 2, 3, different values of L/V and different
iso-K 2 lines (thin lines); SN, saddle-node point.

nonmonotony leads to “tangential pinch.” Figure 5.18 shows the region Reg tang
(it is not shaded), where points N are absent at any points of the top product
+
located at side 1-3 and at any values of parameter L/V (pinch region Reg tang ).

5.4.3. The Product Is a Three-Component Mixture (k = 3)

Three-component mixture is a separation product of initial three-component mix-
ture at nonsharp separation.