Laboratory-scale validation of a DEM model for the cross-screen processes of wet coals

Abstract

In this work, the reliability of a DEM model for the screening process is validated by comparing numerical results and experimental data in a laboratory-scale cross-screen. The validation is carried out in two steps. First, the linear cohesion contact model in DEM is calibrated for simulating wet coal particles. The values of cohesion energy density corresponding to different water contents are determined based on the repose angle test. Then, the screening process of the cross-screen is simulated using the cohesive DEM model and compared with the corresponding experiments. The results show that the discrete model agrees well with the experiment in various aspects. On average, the relative error of the undersize particle yield for segmented screen surface and the total screening efficiency for three different screen surfaces was about 11.8% and 5.7%, respectively. Hence the calibrated DEM model can serve as a useful quantitative tool for screening of wet coals.