Mass Transfer in Irrigated Plane-Parallel Channels at Uniflow Laminar Motion of Liquid and Gas

Abstract

Hydrodynamics and mass transfer in regular film apparatuses containing flat irrigated channels with a laminar flow of gas and liquid as the principal element are studied. The problem is solved by the approximate method, which makes it possible to drastically decrease the amount of the required calculations. It is proven that it is sufficient to determine the dimensionless flux as the function of dimensionless length in a restricted domain of parameters. Approximations are permissible outside the bounds of this domain: in some cases the changes of concentrations in phases along the crosswise direction can be neglected and, in other instances, the concentration changes can be neglected in the whole active mass-transfer region; i.e., diffusion layers exist in one or another phase before the estimation of concentration equilibrium in the system. Finally, the mass transfer resistance is concentrated in liquid or gas; there are parameter spaces where the change of concentration in one of the phases in a crosswise direction can be neglected, while another one contains diffusion boundary layers.