Liquid fluidization of binary particle mixtures—I: Overall bed expansion

Abstract Semi-batch liquid fluidization of binary solid mixtures is investigated for bed expansion, for inversion of solid species and for stratification by size. This first of three papers deals with overall bed expansion, and it is shown that, even where there is total inter-mixing of the two solid species, the bed expands as if it were two single species beds in series. The superiority of this serial model over property-averaging models, and the inapplicability of relative velocity models, for predicting the expansion of semi-batch liquid-fluidized beds of multi-species solids are also demonstrated.