Effect of the Friction, Elastic, and Restitution Coefficients on the Fluid Dynamics Behavior of a Rotary Dryer Operating with Fertilizer

Some fluid-dynamics aspects of a rotary dryer, operating with granular single superphosphate, were investigated experimentally and by coupled discrete element model–computational fluid dynamics (DEM–CFD) simulations. The experimental data of flight holdup and dynamic angle of repose in the upper half flights, at different angular positions, were successfully used to identify the best set of parameters for the spring–dashpot model used in DEM simulations. The smallest deviations from the experimental data were obtained in the simulation whose parameters values were elastic constant k = 400 N/m, friction coefficient μf = 0.2, and restitution coefficient η = 0.2. The results have shown that the coupled DEM–CFD approach with the selected parameters has been suitable to predict the fluid dynamics behavior of the rotary dryer operating with granular single superphosphate.