Page 243 - Packed bed columns for absorption, desorption, rectification and direct heat transfer
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233
P* =19AXf™Ga+r(ad,? M
L
and (131)
l
i
Pe L=7.58xl0T Re %*
The values of Gau and Ren here are defined as in equation (129).
Hochman and Effron [119] carried out experiments with 4.8 mm
spheres using the system methanol-nitrogen. Based on their own experimental
data, they proposed the equation:
Pe L = 0.042i?^ 5
Using data of different investigators and their own, presented in Table
17, Elenkov and Kolev [120] proposed the equation:
33
B
Pe = 0.068 Ref Gaf , (132)
L
where
H dD La
Re L =
Ga L=^j.
The average accuracy of equation (132) is + 25%. The error of the data
of Hochman [119] for 4.75 mm spheres is quite greater and reaches up to 130%.
This might be connected with the influence of the stagnant zones for the liquid
phase in that packing, i.e. with the greater static holdup. In all cases the
accuracy of the experimental data for the axial mixing in the liquid phase is low
because different investigators use different measuring cells and do not account
for their influence. Taking into account this influence, Kolev and Semkov [125]
obtain the equation:
