506
Chapter 11
Gas-liquid
oxygen
transfer
Figure 11.13. Schematic representation of oxygen transport processes.
Liquid
exchange
The correlations for kta used for the well-mixed region (subscript m) were
for the coalescing case and
f
2
.
6-10
-
2
w
°5
V
k}a
m
2-10~3w
0.2
L
V
0 .7
0)
(
2
)
for the non-coalescing case, respectively. The kja value in the bubble region (subscript b) was given by
k;ab =
0.32
u™
(3)
The top bubble region was assumed to start just above the top impeller in both cases. For the non-
coalescing case, the volume of the well mixed region, Vm
, was assumed to be
Vm - n d ,d ,2^
where n was the number of stirrers (=2), dw
was the impeller blade width and dt was the tank diameter.
The liquid flow between the compartments was estimated from the pumping capacity, vr.mr. which was
given by:
v
=
02 N Ad]N
pump
A s
(5)
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