Simulation of motion of particles in high-speed elliptical-rotor-type mixer by particle element method

In order to obtain an insight into the mechanical composing process of particulate materials in a high-speed elliptical rotor type mixer (theta-composer), a S-dimensional numerical simulation (PEM) was carried out to predict the dynamic behavior of the cure particles in the device. Mono-disperse spherical particles with a diameter of 200 mu m were charged into the mixer as cores. The variation of the contact forces acting on the particles and the number of contacts in time were analyzed. The motion of the particle bed in the mixer without rotor predicted by the PEM simulation is in good agreement with that actually observed one. Thus, this particular simulation seems to he reasonable. The compressive force exerted on the particle bed has a maximum at an angle of around 45 degrees in terms of the horizontal inclination of the long axis of the elliptical vessel. The highest deformation forces are found for the particle-rotor contacts as compared to the forces arising from the particle-particle and particle-vessel wall contacts. It is clarified that the force acting on particles due to interaction with the rotor strongly depends on the rpm of the rotor. Therefore, control of the rotational speed of the rotor is important for controlling the deposit layer formation in the theta-composer.