Experiments on granule transport and the mean residence time in a rotary horizontal drum with inclined flights showed that the granules can be transported steadily. A model for granule transport based on the analysis of granule motion and other studies on inclined drums was developed to calculate the mean residence time of the granules, and verification experiments under different conditions were conducted. The calculations agreed well with experimental results. The variation of the mean residence time with feed rate, flight slope and rotation speed was modeled and compared with experimental results. (c) 2005 Elsevier B.V. All rights reserved.