Simulation of particles motion on a double vibrating flip-flow screen surface based on FEM and DEM coupling

The surfaces of vibrating flip-flow screens have the advantages of high vibration intensity, non-blocking holes, easy depolymerization of clustered particles, and self-cleaning functionality, which are widely used in the classification of wet fine-grained granular materials. Various scholars have studied the screening performance, dynamics, elastic elements, and single-particle motion of vibrating flip-flow screens, however, relatively few studies have been conducted on the movement of particles, the elastic screen surface, and numerical simulation of particles on the elastic screen surface. In this study, the numerical simulation was conducted on the elastic screen surface and movement of particles based on finite element method and discrete element method coupling. The result of on a single elastic screen plate indicated that when the excitation angular frequency of the screen was 70 rad/s, the effect of different sizes of particles' stratification on the screen surface was better. The material on the double vibrating flip-flow screen surface exhibited the vibration excitation “filtering effect” on the screen surface; frequency-doubling signals in the vibration response of the stable, transition, and chaotic zones on the screen surface gradually increased, and the particles displayed stable, wave and chaos motions. With an increase in particle size, the particle velocity increased along the direction of the screen surface while decreasing perpendicular to the direction of the screen surface, and the velocity difference between the 10-, 16-, and 25-mm particles was small. A standard deviation analysis of the velocity value demonstrated that the velocity of 10 mm particles can effectively represent the movement velocity of particles on the screen surface. The velocity values in the x and y directions were 1.0725 m/s and 0.8303 m/s respectively. The feed rate had little influence on the movement velocity of the particles.