Influence of the Blades Geometry on the Mixing Phenomena in an Agitating Mixer

Abstract

The mixing behavior of particles in an agitating mixer was simulated by Discrete Element Method （DEM） in order to discuss the particle mixing mechanism. First of all, mixing behavior of alumina and SUS particles in the agitating mixer with a wedge-shaped blade was experimentally observed. Most of the alumina particles existed around the rotational center of the blade, and most of SUS particles were near the mixer wall. The segregation of alumina and SUS particles was obviously observed. The similar mixing behavior of particles was also observed in the DEM simulation, and it was confirmed that DEM simulation has high reliability. Two different types of blades, which are comb-shaped and twisted rectangular prism, were prepared in order to investigate the effect of the blades geometry on the particle mixing phenomena via DEM simulation. The DEM simulation indicated that the mixing state is strongly influenced by the blade geometry. In case of comb-shaped blade, most of SUS particles are at the bottom in the mixer, and most of alumina particles are on and near the surface of particle bed. On the other hand, SUS and alumina particles are uniformly mixed in the mixer with twisted rectangular prism blade promptly. This would be due to reciprocating motion of particles in the depth and the radial direction.