Suspension of solids in a bubbling liquid: Critical gas flow rates for complete suspension

Abstract

Critical solids hold-up data for three-phase batch-fluidized bubble-bed and foam-bed systems are presented, using air as the gas phase, pure liquids and solutions as the liquid phase and quartz, coal and different catalyst powders as the solid phase. Effects of gas velocity, gas distribution, solid particle size, liquid surface tension, liquid viscosity and solid-liquid wettability parameter are established. A correlation in terms of dimensionless groups containing these parameters is proposed. A possible indirect way of evaluating the solid-liquid contact angles for powders from the proposed critical solids hold-up correlation is indicated.