Discrete element simulation study on the screening effect of composite vibrating screen for coal particles

Abstract

ABSTRACT To strengthen the layering effect of coal particles on the screen surface and improve the screening efficiency, a composite vibrating screen was proposed based on the void filling effect of mixed particles under vibration and the Lissajous vibration synthesis theory, and the theoretical basis and working principle of the composite vibrating screen were described. The Taguchi orthogonal experiment was designed with the composite, linear, elliptical, and circular vibrating screens as the object, and frequency, amplitude, and vibration direction angle as the variables, wherein the discrete element simulation of the traditional vibrating screen and the composite vibrating screen was conducted, and the comparison results showed that the composite vibrating screen was of great advantage in both screening efficiency and material processing. On the basis of the traditional vibrating screen, the composite vibrating screen further imposed on the particles an exciting force along the width of the screen surface, so that the particles were subject to the effect of exciting force in the xyz three directions; as a result, more diversified force to the particles, more loose mixed particle system, greater activity degree and better layering effect were realized, and then the composite vibrating screen can achieve a more ideal screening effect.