Density-induced segregation property of solid phase in a three-dimensional liquid-solid fluidized bed

Abstract

This study employs the multiphase particle-in-cell method to explore fluid dynamics and solid segregation processes in a liquid-solid fluidized bed. The model reliability is established through rigorous experimental verification. Subsequently, this study scrutinizes the segregation behaviors of solid phase under various operational parameters. The findings indicate that turbulent viscosity predominantly localizes in regions where liquid and solid phases interact. Increasing the liquid inlet velocity amplifies both radial and axial mass fluxes of liquid and solid phases. Conversely, enlarging the diameter ratio between small and large solid particles, as well as adjusting the density of small solids, exerts negligible influence on radial and axial mass fluxes of liquid phase. As the liquid inlet velocity increases, a gradual reduction in solid concentration occurs, accompanied by an expansion in the solid movement zone. The diameter and density of solid particles exhibit little impact on the axial distribution of solid volume fraction. Notably, disparities in the particle Reynolds number become more apparent beyond an axial height of 0.05 m. Increasing the inlet velocity of liquid phase diminishes segregation intensity. Conversely, altering the solid diameter ratio and the density of smaller solid particles enhances solid segregation. However, solid segregation becomes constrained when the density of smaller solid particles exceeds 1700 kg/m3.