Liquid phase mass transfer coefficients for bubbles growing in a pressure field: A simplified analysis

The rigorous mathematical treatment of the mass transfer process of a solut e between a growing bubble and the surrounding liquid requires the resoluti on of a non-steady state diffusion equation with an expanding surface. In t he present study a simplified analysis of this mass transfer process is pre sented in order to estimate the liquid phase mass transfer coefficients. In particular, the mass transfer process from/into a bubble rising through a liquid pool with a low pressure above the liquid free surface, is considere d. The enhancement factors obtained with this simplified analysis to correc t the liquid phase mass transfer coefficients are overestimated relatively to the predictions obtained with the detailed one but their variation with the bubble expansion rate is well predicted. (C) 2000 Elsevier Science Ltd.