CFD and DEM numerical modelling of industrial vibrating desliming screen for performance optimization and minimal misplacement

Abstract

Desliming screens separate coal slimes from coarse coal, which are treated separately in different unit operations. Misplacements of undersize and oversize significantly hampers the performance of these unit operations. The one-way CFD-DEM method was used to develop the mathematical models to predict the undersize and oversize efficiency as functions of screen vibration frequency, angle, amplitude, and feed rate. A small portion of the screen with periodic boundary conditions was modelled to reduce the computation load. The optimized results from the developed models showed that the screening efficiency could be increased from the current levels of 94.5% to 98% at optimal operating conditions. At optimized conditions, the oversize (-1 + 0.5 mm) mis-placements decreased from 28% to 25%, and undersize (-0.5 mm) misplacements decreased from 4% to negligible levels. The combination of CFD and DEM simulation was identified as an effective tool where per-forming experiments is challenging at an industrial scale.