Mixing and heat transfer of binary mixtures of monodispersed spherical particles with different densities and thermal diffusivities

Abstract

Mixing and heat transfer among particles in rotating drums are widely applied in numerous industrial processes. Generally, mixing and heat transfer occur simultaneously. Consequently, the interrelationship between mixing and heat transfer must be investigated for industrial applications. In this study, the radial mixing and heat transfer of spherical granular materials (3mm) with various properties in batch rotating drums are investigated numerically using the discrete element method. The evolution of mixing and heat transfer characteristics with rotation speed is analyzed from the perspective of time and number of revolutions, respectively. The results indicate that, depending on the physical parameters and thermal properties of particles, the mixing quality does not always accurately reflect the heat transfer effect. In binary granular beds of monodispersed spherical particles with different densities and thermal diffusivities, the main heat transfer mechanism is related to the ratio of the thermal conductivity of the particles to that of the fluid.