Numerical simulation of the dryer drum radiation area using coupled CFD and DEM methods

Abstract

This article investigates the use of coupled computational fluid dynamics (CFD) and discrete element methods (DEM) to simulate the heat transfer by thermal radiation in the material containing zone of an aggregate drum dryer for hot mix asphalt production, a 250mm long material containing zone structure was selected. For the asphalt binder to properly coat the aggregate, the aggregate must be completely dry. This process is accomplished in a counter-flow drum heated by a burner with the flights attached inside the drum walls to facilitate heat transfer. The materials containing drum area was tested and simulated, and the material temperature rise and drum temperature were obtained, with an error of less than 5% from the experimental results, indicating that the simulation is feasible. The results of the study show that the best heat radiation effect is achieved with a semi-contained flight; the material temperature increases and then decreases as the output increases. The flame diameter increases by 1.5 times, the heat radiation effect is enhanced. The preliminary results may provide some guidelines for operating the dry drum efficiently and designing drum to control quality of material mixes and save energy.