Modeling of the motion of particles in a rotary crusher

The dynamics of the gas flow in the interdisk space of a real crusher is studied. It is shown that the centrifugal force displaces the gas from the space between the rotating disks. This decreases the probability of collision between particles coming from different disks. The gas displacement near the disk surface is illustrated using the example of a system of two counterrotating flat disks. An exact self-similar solution is obtained. The flow between the two disks is demonstrated to be qualitatively rearranged in comparison with the flow over a single rotating disk. Using a two-parameter turbulence model, the gas dynamics are calculated both in the set of two disks and within a real crusher. The results of calculating the trajectories of particles are presented. The causes that limit the minimal particle size that can be reached in a rotary crusher are analyzed.