DEM analysis of the thermal treatment of granular materials in a rotary drum equipped with baffles

Rotary drums play a vital role in the thermal treatment of granular materials in processes such as calcination and drying in various industries. Baffles/flights in rotary drums are utilized to improve mixing and heat transfer, effectively decreasing the heating time while improving the final product's uniformity. A series of simulations were performed with different operating conditions and particle properties such as fill level, baffle size, number of baffles, thermal conductivity, and particle size using the discrete element method (DEM) coupled with heat conduction. We categorized the simulation results based on the ratio of the baffle height to bed depth and introduced an optimum condition for adding baffles. A model was proposed to estimate the heating time for particles as a function of the number and size of the baffles for different operating conditions and particle properties, thus providing a method to predict heating in a rotary drum with baffles.