EMULSION PHASE EXPANSION AND SEDIMENTATION-VELOCITY IN FLUIDIZED-BEDS OF FINE PARTICLES

In fluidized beds of fine particles, minimum fluidization velocity U//m//f, voidage of the emulsion phase epsilon //e , and sedimentation velocity U//s were measured for various gas-powder systems. For both U//m//f and U//s, the relationship between velocity and voidage was experimentally determined on the basis of the Richardson-Zaki equation. The voidage of the emulsion phase was correlated by a dimensionless parameter taking into account the effect of gas density. By using this correlation and the relationship between velocity and voidage obtained in this study, U//s was expressed as a function of U//m//f. The calculated U//s from U//m//f agreed with the experimental data.