Page 72 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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tending to infinity. Obviously, the number of mass transfer units which
corresponds to a theoretical plate in countereurrent flow can be calculated by
the equations:

for concentrations of the gas phase

MTTJ = —Si (239)
ill U Te —

for concentrations of the liquid phase

(240)

The concentrations of both phases are explained in Fig. 10.

Xm

Fig. 10. Theoretical stage.

Where k 2=G x/Gf,
In integral form instead of Eq. (239) and (240), it can be written

NTU = J dY (241)
re
Y*-Y