Assessment of bi-disperse solid particles mixing in a horizontal paddle mixer through experiments and DEM

Abstract

In the current study, the mixing of bi-disperse particles in a horizontal paddle mixer was investigated through the sampling experimental technique and discrete element method (DEM). LIGGGHTS software was employed as the DEM solver. A close agreement between the simulation and experimental data was observed. Using the calibrated DEM model, the influence of some operating parameters such as impeller rotational speed, vessel fill level, particle number ratio (rn) and particle loading arrangement on the mixing quality was analyzed. A detailed analysis of this specific type of mixer comprising bi-disperse particles has not been reported in literature. It was found that rn had the most significant effect on the mixing performance. It was also found that the diffusion mechanism was dominant over the convection mechanism and in the cases in which the values of the diffusion coefficients of 5 mm and 3 mm particles were close, the best mixing performance was achieved.