Heterogeneous fluidization in non-Newtonian liquid fluidized beds

A non-Newtonian liquid fluidized bed containing spherical steel particles and titanium dioxide slurry simulated using CFD was observed to exhibit heterogeneous fluidization reminiscent of bubbling fluidization in gas fluidized beds at high inlet superficial velocities. This fluidization behavior was reproducible using three different drag force models, the Gidaspow, Wen and Yu and Gibilaro drag force models, in the CFD simulations. Good agreement was observed between the space- and time-averaged voidage values obtained from the simulations using the Gibilaro drag force model and those obtained from CFD-DEM simulations and experiments by previous researchers. A second non-Newtonian liquid fluidized bed investigated in this study containing spherical glass particles and aqueous tylose exhibited channeling behavior at high inlet superficial velocity that was reminiscent of channeling behavior in gas-solid fluidized beds containing Geldart group C particles and spouting behavior in gas-solid fluidized beds containing Geldart group D particles. This fluidization behavior was also reproducible using the three different drag force models. By comparisons of space- and time-averaged voidage values obtained from the simulations using the three drag force models with those obtained from CFD-DEM simulations and experiments by previous researchers, it could be concluded that the Gidaspow model was more accurate than the Gibilaro model in computing drag forces in this non-Newtonian liquid fluidized bed. • Fluidization behaviors of non-Newtonian liquid fluidized beds were studied with CFD. • At high inlet velocities, the first fluidized bed showed heterogeneous fluidization. • At high inlet velocities, the second fluidized bed showed channeling behavior. • The fluidization behaviors were reproducible with three different drag force models.