A New Approach to Monitoring the Movement of Particulate Material in Rotating Drums

Rotating drums are widely used for a variety of particle processing operations including mixing, calcining, and granulation. The mode of motion of the particles can be characterized as one of seven regimes and three of these, “slumping”, “rolling”and “cascading” are relevant to industrial practice. This paper describes apparatus in which a rotating cylinder is mounted on a pivoted framework acting on a load cell. Changes in the position of the centre of mass of the material in the drum cause changes in the moment measured by the load cell, and experimental results are presented showing that the variance of the load cell signal can be used to track the transition from slumping to rolling. A simple model that can facilitate the interpretation of the load cell output in terms of gross movement of material in the drum is outlined, and load cell response in the slumping regime, is discussed with reference to video footage of particle motion.