Page 141 - Distillation theory

P1: JPJ/FFX P2: FCH/FFX QC: FCH/FFX T1: FCH
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5.2 Calculation of Distillation at Minimum Reflux for Ideal Mixtures 115

x D
a) b)
2 2
y F
x B
S
S

x
+
+
N x F D N x F
x D y y
F F
1 3 1 3
−
N N −
2 2
c) d)
S
S

x B
x
x D B
y
y N + F
F
x
D
1 3 1 − + 3
N N
−
N
2 S 2
S
e) f)

x
B x B
y
y F F
x x D
D
1 − 3 1 − + 3
N N + N N
R
Figure 5.2. Evolution of a rectifying section region Reg w,r for a ternary ideal mixture: (a) R <
2
1
1
1
2
R , (b) R = R , (c) R 2 > R > R , (d) R = R , (e) R > R , (f) R =∞.
lim lim lim lim lim lim
one-section column, there are two zones of constant concentrations, the compo-
+
sitions of which coincide with the compositions in stationary points N and S.
At α i = const and L/V = const, the part of the trajectory located inside the
+
concentration triangle S → N is rectilinear.