Impact of screening coals on screen surface and multi-index optimization for coal cleaning production

Abstract

Abstract Vibrating screen is the key screening equipment in coal cleaning. With the increase in coal production, vibrating screen with large processing capacity, high reliability, and excellent screening effect is essentially required. In this study, particle velocity, mass of oversized material, screening efficiency, and impact force were regarded as important evaluation indexes to reflect the performance of vibrating screen. The motion analysis of single particle on screen surface was performed, and the theoretical model of impact force was proposed in order to search for the most significant influencing factors. These indexes were investigated by discrete element method. Furthermore, the data coupling between discrete element method and finite element method was applied, and the distribution of stress and deformation of screen surface under impact force were obtained. Single factor analysis was carried out for the comprehensive evaluation; and the influence law of amplitude, frequency, inclination angle, and vibration direction angle on evaluation indexes was discussed. Based on orthogonal experiment and range analysis, the combined effects of factors on each index were systematically analyzed, and optimization schemes for every index were put forward. The result of this study showed the dynamic response of screen surface under impact, revealed the relationship between vibration parameters and evaluation indexes, and provided an adjustment method for multi-index evaluation, which was found to be feasible for the effective improvement of the performance of vibrating screen.