Hydrodynamic characteristics of inverse fluidization in liquid—solid and gas—liquid—solid systems

Abstract

The flow characteristics of inverse fluidization utilizing low density spherical particles are experimentally investigated for both the liquid—solid and gas—liquid—solid systems. The experimental data for the bed expansion in the liquid-solid system are correlated, both empirically and semi-empirically. In the gas—liquid—solid system in which the gas and liquid flows are countercurrent, two modes of fluidization are examined. They are fluidization with the liquid as a continuous phase and fluidization with the gas as a continuous phase; the former characterizes the inverse gas—liquid—solid fluidized bed, while the latter characterizes the turbulent contacting bed. A flow regime diagram which portrays these modes of fluidization is presented. Correlations of the bed expansion and gas hold-up are proposed for the inverse gas—liquid—solid fluidization.