Effect of Particle Shape On Just Suspended Impeller Speed

There has been little to no research done on the effect of particle shape on the ability of suspending those particles. The goal of this study was to determine this effect of particle size and shape in solid-liquid suspensions. Three Aluminium shape geometries were tested: spheres, rods, and plates. These experiments were performed holding the density of the material constant and using a single tank and impeller geometry. It was determined that at equivalent solid-liquid mass fractions, spheres were the most difficult to suspend requiring higher impeller speeds than both rods and plates.  In addition, the required speed to just suspend rods and plates was very similar. New correlations were developed based on the Zwietering equation for the three Aluminium geometries tested in this study. It was found that the minimum dimension of each shape is the controlling factor in determining the minimum just suspended speed of the particle at constant weight percentages.