Simulation of heavy particles fluidized with non-Newtonian fluids

Aqueous solutions of very fine particles behave as non-Newtonian fluids and are used to fluidize heavy spherical particles creating large bed expansions and inhomogeneities similar to those observed in traditional fluidization of particles with Newtonian fluids. This study attempts to extend the validity of traditional computational fluid dynamics (CFD) models that are routinely used for gas-solids fluidization to non-Newtonian fluids. The modified model incorporates a shear-thinning power law viscosity for the non-Newtonian fluid and a recently published drag correlation derived from direct numerical simulation data of flow around randomly positioned spheres. This validation study compares numerical results obtained in 3D fluidized beds with two independent experimental bed porosity data sets for heavy steel and glass spherical particles. The current CFD results show a better agreement with experimental data obtained over a wide range of porosity and Reynolds number than a previously published semi-empirical correlation.