Mass transfer between solid particles and liquid in a three phase fluidized bed

Abstract
Particle‐liquid mass transfer in a co‐current three‐phase fluidized bed of glass beads, water and air was studied with two measurement techniques. Both techniques measured the weight loss of a few particles coated with benzoic acid in a bed of inert glass beads. The effects of liquid and gas velocities, gas distribution and surface active agents on particle‐liquid mass transfer in a three‐phase fluidized bed were thus determined. In the absence of surface active agents in the liquid, particle‐liquid mass transfer rates in a three‐phase fluidized bed were up to 30% higher than in the corresponding liquid fluidized bed. When surface active agents were added to the liquid, the particle‐liquid mass transfer rate was increased by up to about 100% in the three‐phase fluidized bed, relative to the liquid fluidized bed. The particle‐liquid mass transfer coefficient was found to be inversely proportional to the liquid hold‐up in the three‐phase fluidized bed.