Page 301 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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The mean error of equation (198) is 6%, and the maximum- 39%. Two
of the experimental points have deviations over 30%.
It can be assumed, that the packing void fraction affects the gas-side
controlled mass transfer through the packing volume occupied by the packing
material (1-e), i.e. through the cross-section of the packing material flown
around by the gas. Taking into account this possibility the following equations
are presented [167]:

With Zhavoronkov's correction of the gas velocity:

74 3 u7(I Sll) U7
Sh G = 0.090 Re G Sc G (h / d h y - s^ (199)

The mean error is 9% and the maximum one is 39%. One of the experimental
points has a deviation of 30%.

Without Zhavoronkov's correction:

/3 M(I SJ U0
Sh G = 0.137 Re™ S4 (h/d hy ~ e~ (200)

The mean error is 7% and the maximum one is 43%. Four of the experimental
points have deviations over 30%.
The arithmetical mean difference between the data calculated with the
last two equations (with and without Zhavoronkov's correction) is 6%. The
comparisons of the experimental data for the packings given in Table 28 and the
lines calculated using equations (199) and (200) are presented in Fig. 61 and
Fig. 62 respectively.
The comparison between the two equations shows that though the
correction of Zhavoronkov is physically grounded, it does not improve the
equation accuracy.

3,2,2,1,2.5, Liquid-side controlled mass transfer coefficient of packings with
vertical smooth walls
For calculating the liquid-side controlled mass transfer coefficient
Ramm and Chagina [140] proposed the equation:

m
0 m
k La h = lL6Lf .h' - , (201)