Page 211 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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in which Ffj^ is the modification of the Froude number for the liquid phase
defined as follows:

(76)

(77)
a

f w is a factor that depends on the load and is specific for the packing. Billet
[177] mentioned also that this factor is a measure of the uniformity of the liquid
distribution and thus of the degree to which the surface topography of the
packing is exploited. The higher the Reynolds number, the higher the factot f w.
3
According to measurements in a range of low viscosity up to 8x10"
Pa.s and surface tensions up to 0.02 N/m, carried out under standard conditions,
1 3
the product ^.Re^ ^ remains almost constant for a given liquid in the
operating range below 70% of the flood point (under the loading point). I. e. it
can be written

(78)

where Co is a packing factor for the respective system with kinematic
viscosity v 0.
Thus, the liquid holdup can be expressed by means of the following
equation

r \l2-\ p r U3 nq\
V
\ L J

The value of Co for some packings can be taken from Table 12.