Page 249 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

239

Re/4

Fig. 36. Comparison of experimental data for gas-side controlled mass transfer for Berl saddles
with Eq. (141).

It must be mentioned that according to the Buckingham theorem for
determination of the dimensionless numbers in this type of equations, the
number of the complexes in Eq. 141 is 4, but not 5. That is, the Galilei number
is not necessary,
Zhavoronkov, Gildenblat and Ramm [130] proposed the equation:

S3 33
= 0.407 Re™ Sc° G (142)

This equation describes the experimental data for random Raschig rings
and saddles.
For calculating the volumetric gas phase controlled mass transfer
coefficient, Billet [177] proposed the equation:

k Ga-C v. (143)

The constant C v depends on the type and dimensions of the packing. Its value
for different random packings is presented in Table 10.