A continuum model for the segregation of bidisperse particles in a blade mixer

Abstract

AbstractThe process of blending powders using stirring blades involves complicated granular flows, particle‐scale mechanisms, and blade–particle interactions, which is challenging to predict and control. This article proposes a continuum‐based model for such a process by incorporating the flow rheology, isotropic particle diffusion and the percolation of granular materials. A method combining finite element method (FEM), finite difference method (FDM), and immersed boundary method (IBM) is developed to numerically implement the continuum model and applied to a cylindrical blade mixer. The model well describes the tempo‐spatial distribution of small/large particles in the stirring process, such as the accumulation of small particles in the vicinity of blades. Remarkably, this model can capture the various intricate effects of blade parameters, including the blade rake angle, rotating speeds, filling level, and the friction coefficient of the mixer wall. It is therefore promising for optimizing the blade mixers in industries.