1988 Volume 21 Issue 2 Pages 107-112
The mass transfer coefficients between solid particles and turbulent liquids were measured in agitated vessels. For large particles characterized by large values of the specific power group (γ1/3d4/3/v), the measured mass transfer coefficients were in good agreement with Levins and Glastonbury''s correlation. For fine particles less than 100μm, however, the mass transfer coefficient deviated below their correlation, reaching more rapidly the theoretical limiting value Sh = 2 for molecular diffusion in an infinite stagnant fluid. This lends the first quantitative support to the postulate that fine particles may stay in and move together with microeddies. A new correlation for the mass transfer coefficient is presented. The effect of particle density and vessel diameter on the mass transfer coefficients was found to be negligible. Furthermore, the effect of solid particle concentration was found to be of little importance in the range of specific surface area up to at least 3000m2/m3 of liquid.