Page 242 - Packed bed columns for absorption, desorption, rectification and direct heat transfer
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Another equation, describing the experimental results of different
authors for Raschig rings 25.4 mm and 12.7 mm, is proposed also by Maeias-
Salinas and Fair [205].
Pe G =998.19Re- 0Mll .10~ 0Mm "^ (128)
3.2,1,2.1.5.2. Axial mixing in the liquid phase
The axial mixing in the liquid phase of random packings is investigated
by many scientists [115-126,203-213].
For determination of the axial mixing coefficient in the liquid phase
Otake et al. [115] proposed the equation:
s
1
Pe L = 5 ^ = 0.527 Rej^ Ga^ , (129)
ML
2
where D L is the axial mixing coefficient for the liquid phase in m /s. Re u is
the Reynolds number defined with the diameter of a packing element and with
the average real liquid velocity in the packing as follows:
R ^
The Galilei number is also defined with the packing element size:
Later Kunugita Otake and Yamanashi [117] presented the equation
0 77
33
Pe L = 1.425GoC" Re ^ (130)
Based on their own data for Berl saddles and Raschig rings with 7.85 to
15.5 mm size, Sater and Levenspiel [118] offered the equations: