Scale-up of heat transfer in a rotary drum equipped with baffles

Abstract

In this study, discrete element method (DEM) simulations were performed to investigate how baffles regulate heat transfer in a rotary drum. In order to scale up the system, we established an empirical relationship based on a new characteristic time for baffles that predicts the average particle bed temperature. Particle fill level, drum size, baffle size, baffle number, and rotation speed were adjusted to alter the operating conditions of the rotary drum. Thermal conductivity and particle size were also examined as influences on material properties. It was found that increasing the number and size of baffles significantly improved the rate of heat transfer but had no significant effect on particle temperature distribution and bed uniformity. Baffle effectiveness was found to be correlated with the fill level and rotational speed such that higher rotation speed generally increases temperature uniformity without significantly increasing the rate of heat transfer.