Collision Energy Analysis within the Vertical Shaft Impact Crusher Based on the Computational Fluid Dynamics-Discrete Element Method.

Abstract

Particles in the vertical shaft impact crusher absorb and dissipate collision energy in the impact breakage. The distribution of the collision energy determines the breakage rate of materials and breakage energy consumption of the entire system. In this paper, the gas-solid coupling method is used to explore the regional distribution of collision energy, collision frequency, and collision energy spectrum of the material particle groups. Hence, a theoretical basis is provided for the efficient and energy-saving design of the crusher. First, a coupling mathematical model of the computational fluid dynamics and discrete element method is established to describe the interaction between material and fluid in the crushing chamber. Moreover, the experiment is carried out using a PL8500 VSI crusher and compared with the simulation results to verify the model's reliability. Finally, the effects of different working conditions on the energy dissipation distribution and energy spectrum are explored. The results show that the collision energy within the crushing chamber can be accurately predicted by using the fluid-solid coupling model. Moreover, increasing the rotational speed can effectively transform low-energy collision events into high-energy collisions and increase the collision frequency with energy dissipation above the threshold energy. Thus, the probability of material breakage is increased. Last, increasing the feed rate minorly affects the material breakage rate, while the specific energy of the entire system is reduced.