Effect of pseudoplastic behaviour of liquid in co-current three-phase fluidized beds on beds expansion

摘要

Gas hold-up and bed expansion measurements were carried out for a bed of glass beads fluidized in Newtonian liquids and non-Newtonian liquids with gas. The value of hold-up increased and decrased with increasing particle size and liquid velocity, respectively. The effect of rheological properties on gas hold-up was insignificant and therefoe the gas hold up data for both Newtonian and non-Newtonian fluids were reasonablly fitted by the available correlation which had no liquid viscosity term. The bed voidage increased with increasing superficial liquid velocities and superficial gas velocities. The increase of the viscous non-Nertonian flow behavious resulted in an increase of the bed voidage. The correlation for the bed voidage in three-phase fluidized beds were developed for gas-Newtonian or non-Newtonian liquid-solid three-phase systems by combining the generalized wake model and the correlation for liquid-solid two-phase systems proposed previously by the authors. The predictions for bed voidage were in reasonable agreement with the present experimental data for three-phase systems with Newtonian and non-Newtonian liquids in a wide range of Reynolds numbers