Mass transfer with buoyancy driven convective cells

Abstract

In an attempt to find the relationship between the mass transfer coefficient and the parameters involving cell size and amplitude, the problem of steady state mass transfer through a stagnant layer of liquid heated uniformly from below is analyzed theoretically. It is shown that the mass transfer coefficient in the presence of buoyancy driven convective cells is related to a single dimensionless group consisting of cell number a, cell amplitude A, Lewis number Le, Schmidt number Sc and Rayleigh number Ra. Concentration profiles that are established deviate from those given by the film theory depending on the magnitude of this dimensionless group. Justification of the theory requires experimental methods in which the amount of the transferred mass and the cell characteristics are measured simultaneously.