The Research Of Granular Piling And Bulk Material Transfer Process Using DEM Simulation

Discrete element method (DEM) is a numerical method of studying mechanical behavior of the discontinuity (discrete body) by explicit solution, which can simulate the detailed interaction such as contact or collision process. In the absence of a reliable theory about motion of particles in industrial equipment, discrete element simulation can design and optimize the equipment and measure data more easily than experiment, so it better solve practical problems.Angle of repose reflects the macroscopic characteristics of granular particles. In the mine production system, angle of repose affects the upgrading angle of conveyor, which results in large arrangement area of belt conveyor, large project, long conveyor. Discrete element method helps to understand the micro-mechanics mechanism of granular piling, so in this article DEM software is applied to simulate three-dimensional granular piling problem and to analyze how particle-particle, particle-plate friction coefficient and particle shape affect angle of repose.In the bulk material handling systems, especially large tonnage continuous conveyor system, transfer station occupies an extremely important position. Based on discrete element method, DEM software is applied to simulate the bulk material transfer process. The current DEM method still cannot calculate the motion of tiny particles, through the comparative calculations of different particle size 75mm,100mm,150mm, we find that the simulation results are close with the actual operating conditions in particle size range of 50-300mm. The feeding direction is also analyzed in the transfer process. Put forward to using the impact coefficient to characterize the impact influence, the coefficient can be used to compare the impact effect of different cases for blanking height and particle size. The maximum force and impact coefficient can be obtained by computer simulation of single particle and particle flow, which better reflects the impact effect of particle flow. The fact that the normal force acting on the conveyor belt due to the impact effect of particles approximates to the gravity of bulk material also verifies the accuracy of the results. Material offset on conveyor is qualified according to the required offset of conveyor belt when material flow concentrates on belt, we also improve the structure of the bifurcation chute. Through the comparative analysis using normal distribution of particle size 50-300mm, we get the conclusion that material migration lessens after modification.