Abstract:
The screening efficiency and average transport speed of materials are important indicators for measuring the performance of screening machinery. In recent years, few breakthroughs have been made in traditional screening machinery. As high-efficiency vibration machinery, high-frequency vibrating screens have become widely used in recent years, but the operational methods of high-frequency vibrating mesh screens are relatively unique: the screen box is fixed and the screen is vibrated at a high frequency. Despite its wide use, there are relatively few studies about the materials movement law and screening characteristics of high-frequency vibrating screen. In this study, a discrete element method (DEM) was used in a simulation of the screening process of the spherical and nonspherical particle groups, and an experimental study was also conducted. The results show that changes in the screening efficiency in the simulation of spherical and nonspherical particles are consistent with those observed experimentally, but the simulation results for the nonspherical particles were closer to those obtained in the experiments. Orthogonal designs and multiple sets of simulation tests were conducted to analyze the influence of each vibration parameter (vibration frequency, amplitude and mesh inclination) on the particle distribution curve, screening efficiency, and average transport speed of the materials. Multivariate nonlinear fitting was performed on the data using the orthogonal test table, and the relationship between the screening efficiency and the vibration parameters was obtained. Based on this relationship, the optimal vibration parameters were obtained and verified in the simulation. The results obtained in this research provide a theoretical basis for the design of the vibration parameters of the high-frequency vibrating screen, and the experimental and simulation data provide support for the investigation of the screening mechanism of the high-frequency vibration system.