Liquid fluidisation of binary particle mixtures - III. Stratification by size and related topics

This final paper in a series of three on continuous steady-state liquid fluidisation of an unchanging batch of bottom-restrained binary solid mixtures deals primarily with the problem of stratification by size, which is shown to depend on the bulk density difference of the two particle components when each is fluidised separately by the same liquid at the same velocity, normalised with respect to the buoyed density of the particles. This simple composition-independent approach to particle segregation by size is formulated in the context of the more sophisticated composition-dependent approach to the bed inversion problem developed by Gibilaro et al. (1986, Chem. Engng Sci., 41, 379-387), which involves complete or partial segregation by density ('sorting') at low velocity and partial or complete segregation by size ('sizing') at high velocity. (C) 1998 Elsevier Science Ltd. All rights reserved.