Measuring powder flow properties in a rotating drum

Abstract

The rotating drum geometry is widely used to analyze the flow of powders and granular materials in low consolidation conditions. Many different physical quantities can be measured using image analysis algorithms. This variety of methods makes it difficult to compare the results obtained with different set-ups and methods. In this paper, the set of physical quantities (Dynamic angle of repose α, Cohesive index CI, Roughness index RI, Aeration AE and Thixotropy index TI) measured by GranuDrum instrument from the images using dedicated algorithms are presented in details. Moreover, the results obtained with a set of typical powders are analyzed to illustrate the interpretation of the different measurements. For the whole set of parameters, a strong dependence to the drum rotating speed is shown by the measurement results, highlighting the importance of the measurement at different flowing speeds. Moreover, time-dependent or shear-dependent properties are evidenced.