Computational investigation of contraction behavior in a liquid-solid fluidized bed

Abstract

Contraction beha ior of a liquid-solid fluidized bed has been in estigated numerically. ased on a sim le hydrodynamic model ro osed by randani and hang (2006), a case study for solid articles with a density of ,000 g m and a diameter of 2.5 10m is simulated in a two-dimensional uidized bed (0.50 m height and 0.10 m width). Due to the continuity of numerical com utation, there is a transition region between two zones of different solid holdu s when the liquid elocity is suddenly changed. he to , middle and bottom interfaces are e lored to obtain a reasonable interface height. he simulated results show that the steady time of the middle interface is more close to Gibilaro's theory and suitable for describing the contraction rocess of a hase interface. urthermore, the effect of liquid elocity and article diameter is simulated in the other two-dimensional fluidized bed (0.10 m height and 0.02 m width) where the solid articles are glass beads whose ro erties are similar to those of the catalyst articles used in the al ylation rocess. he results also show good agreement with Gibilaro's theory, and that larger articles lead to a more ob ious bed contraction.