Page 246 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

236

100

1
i
j
|
m 8 o
• « o °
& ; c
1
rf 10 -fc i
i 1
H
O

20
Liquid mass vetasity,

Liqiid f low: W3ter Q 25.4-mm Raachig rings [ 202 ]
Tracer; Sad m 26.4-mm Raschig rings [ 204 ]
H L=0.»144 m a 25.4-mm Pall* rings
• SuliBr*BX
n n 8«ipac«2

Fig. 34. Liquid-phase Bodenstein number vs. liquid mass superficial velocity. Hi is the length of
the packing between the sensors.

3.2.1.2.1.5.3. Radial mixing in the liquid phase
For determination of the Peclet number in radial direction for the liquid
phase Pei n the following equation is presented [274]:

Pg = —£- = $ (135)
" A,

2
where Di, is the radial mixing coefficient for the liquid phase in m /s.
3.2.1.2.1.6. Equation for calculation of the mass transfer coefficients

3.2.1.2.1.6.1. Gas-side controlled mass transfer coefficient

3.2.1.2.1.6.1.1. Coefficient for the piston flow model
Using own data for evaporation of water in air stream obtained in
column with a 280 mm diameter for random rings 13, 25 and 50 mm, arranged
rings 50 mm, and Berl saddles 6.5 and 13 mm, Teacker and Hougen [127]