DEM simulation of particle flow and separation in a vibrating flip-flow screen

Abstract

Vibrating flip-flow screens (VFFS) with stretchable polyurethane sieve mats have been widely used in screening fine-grained materials in recent years. In this work, the discrete element method (DEM) is used to study the screening process in VFFS to explain particle flow and separation behavior at the particle scale. Unlike traditional vibrating screens, for VFFS, the amplitude response of each point on the elastic sieve mat is different everywhere. This study measures the kinematics of the elastic sieve mat under different conditions such as different stretched lengths and material loads. To establish the elastic sieve mat model in a DEM simulation, the continuous elastic sieve mat is discretized into multiple units, and the displacement signal of each unit tested is analyzed by Fourier series. The Fourier series analysis results of each unit are used as the setting parameters for motion. In this way, the movement of the elastic sieve mat is approximately simulated, and a DEM model of VFFS is produced. Through the simulation, the flow and separation of different-sized particles in VFFS are studied, and the reasonability of the simulation is verified by a pilot-scale screening experiment. The present study demonstrates the potential of the DEM method for the analysis of screening processes in VFFS.