ABSTRACT
The model consists of a tube with gas flow and the walls filled by flowing liquid. Such a model simulates many chemical, metallurgical, and other systems involving the absorption process. To simplify the problem, it is assumed that the gas flow rate is high, so that the influence of solute on the flow and mass transfer is negligible, the velocity profiles in both phases are fully developed, and the liquid film thickness is small versus the tube radius. In such a case, the problem is governed by two diffusion equations:
u c z
D c
r k c c R r R U
C z
∂ ∂
= ∂ ∂
+ − ≤ ≤ ∂ ∂
= ∂ ∂
1 ( ), ,
r r
c r
r R ∂ ∂
≤ ≤, 0 (9.1)
The lower letters and capitals as well as subscripts L and G are used for liquid and gas parameters, respectively; c and C are concentrations; R and Re are internal and external radii; k is the first-order reaction constant; and ceq is the equilibrium concentration.
