MASS TRANSFER TO THE FREE INTERFACE IN STIRRED VESSELS

Liquid-phase mass transfer coefficients between gas and a flat liquid interface in a stirred tank are proportional to the average rate of energy dissipation raised to the power of one third for water and one quarter for organic solvents. This discrepancy can be attributed to the presence of surface active contaminants in aqueous systems. The critical value of the Reynolds number for the transition between the regime controlled by the small scale turbulence to that controlled by large scale eddies is about 100. The Levich-Davies model was found inappropriate in this case.