Power draw estimations in experimental tumbling mills using PEPT

Positron Emission Particle Tracking (PEPT) was employed to reconstruct the motion of mono-sized glass beads in an experimental tumbling mill run in batch mode. In each case, the derived trajectory field of a representative tracer particle was used to determine the charge power draw at steady state operation. Two approaches for calculating power draw were considered: the torque of the centre of mass about the mill centre, and the time averaged torque contribution per discrete grid cell summed over the volume of the mill. Results were compared across different operating conditions and particle sizes to measured power.

Research highlights
► PEPT tracking experiments found to be means of determining charge behaviour in tumbling mills.
► Using mean centre of mass of PEPT coordinates with mill velocity to calculate power draw led to underestimates.
► Power draw calculated from PEPT data using cumulated torque of discrete cells yielded accurate estimations of mill power.