Abstract
The published correlations for the velocity-voidage relationship observed during fluidization and sedimentation of uniformly sized spherical particles in solid-liquid systems are compared with published experimental results. It is found that the expression suggested by Richardson and Zaki represents the experimental data well over a wide range of values of Galileo number (10−2 < Ga< 1010) and voidage (0·4 < ϵ < 1). Methods are given for predicting the constants in the expression as a function of the properties of the system, including wall effects.