(238b) Dynamics of Monoshaped Non-Spherical Particles In a Cylindrical Tumbler

The dynamics of granular materials in cylindrical tumblers have been studied extensively. However, even though it has been known for a while that the shape of particles may affect significantly their dynamical properties, most reported studies on this topic have involved so far spherical or quasi-spherical particles. This is no doubt in part due to the difficulty in producing monoshaped non-spherical particles with given properties, and singling out the effect of particle shape on particle dynamics.

The objective of this talk is twofold: first, to present an optimized approach for the production of identical non-spherical particles suitable for radioactive particle tracking (RPT) experiments, and then to use RPT as a characterization method to investigate the dynamics of these particles in a cylindrical tumbler. The particles are in fact tablets that were produced using a high-performance Korsh XL100 press, and irradiated in the Slowpoke reactor of Ecole Polytechnique de Montréal. These tablets were coated with an aqueous solution of Opadry II (Colorcon) to alleviate friability problems in the tumbler. Results obtained in the case of seven different tablet shapes with significantly different sphericity indices in a cylindrical tumbler rotating at various speeds will be presented. In particular, velocity, trajectory and occurrence fields, as well as radial and axial mixing efficiencies, will be discussed in detail to highlight the effect of particle shape on flow and mixing dynamics.