HYDRODYNAMIC STUDIES OF BED EXPANSION IN LIQUID SOLID FLUIDIZED BED

Abstract

Expanded bed behavior was modeled by using the Richardson-Zaki correlation between the superficial velocity of the feed stream and the void fraction of the bed at moderate Reynolds number. The terminal velocity expression was developed by introducing two empirical parameters, the effective diameter of the particles and an exponent for the    p l l l     2  term. The Richardson-Zaki exponent constant (n) was found to vary with the density ratio   p l l    and diameter ratio d D p . It was noted that when the density ratio   p l l    is less than one, there is no dense phase at the bottom of the test section. However, for density ratio   p l l    greater than unity, there exists accelerating or dense regime at the bottom of the test section.

Keywords

• Liquid-solid fluidized bed, Bed expansion, Richardson-Zaki correlation