Page 196 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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where A is the dimensionless parameter calculated by Eq. (22). The values of
the constants Bi and B^ depending on the type and dimensions of the packing
and also on A are presented in Table 9.
Eq. (41) in comparison to Eq. (40) has the advantage that on the right-
hand side there are no terms including the gas velocity, which makes it easier to
determine w§. So calculating Fby Eq. (41) using Eq. (39), we can easy obtain
wg at the loading or flooding point.
For determination of the flooding point Sherwood et al. [41] have
offered the equation:

(42)
Pi

The equation is used by Labo et al. [42] who offered a diagram based
on it, presented in Fig. 14. It is noteworthy that the differences between the
experimental points and the curve in the figure in some cases are more than
300%.

Table 9, The values of A, B, and B 2 in Eq. (41) for different packings
A B, B t
Ceramic Raschig rinp (<30 mm)
Loading point 0-07 0.046 1.0
Flooding point 0-0.2 0.168 1.83
Flooding point 0.2-1 0.081 1.22
Ceramic Raschig rings (>3Q mm)
Loading point 0.2 - 0.7 0.0243 1.165
Flooding point 0.3 - 0.7 0.118 1.22
Steel Raschig rings (25 - 50 mm)
Loading point 0.3 - 0.55 0.081 1.44
Flooding point 0.55 - 0.8 0.067 0.96