TURBULENT MIXING-LENGTH MODEL FOR AXIAL TURBULENT DIFFUSION OF LIQUID IN THREE-PHASE FLUIDIZED BED

Abstract

The axial turbulent diffusion coefficient of liquid, E_l, was investigated experimentally and theoretically in a three-phase fluidized bed where the solid concentration at the bottom of the column was less than 1200kg/slurrym³. The measurement was conducted in a column of 0.07 m diameter and 4.25 m maximum height. The solid phase was glass beads of 230 μm and 450 μm diameter. No appreciable effect of the solid concentration on gas holdup was observed under the present conditions. It was also shown that a model based on the turbulent mixing-length theory was in good agreement with experimental values of E_l. Data in the literature for column diameters of 0.07-1.07 m were also well explained by the present model.