Segregation Behavior of a Mixture of Spherical Steel Balls and Wood Chips in a Rotating Tumbler with Internal Baffles

International audience; The aim of the present work is to simulate the segregation and interaction between the two kinds of particles involved. Thesimulation is made using the Discrete Elements Method (Ref 1) implemented in the Open Software LIGGGHTS (Ref 2). The wood chips are represented using either a multisphere approximation or a single sphere model. In both approximations, the model particles have the same volume and the same dynamic properties as the wood chips.The following differences differences between the two approximations are observed:- The transient behaviour of mixing is slower with the single sphere approximation than with the multisphere one. Differences are specially notable at low rotation speed.- The multisphere approximations shows that the orientation of the wood chips is approximately anisotropic except near the walls or the baffles- At given values of the number of steel balls and wood chips and of the rotating speed, the average porosity of the bed is smaller with the multisphere approximation than with the single sphere one.With both approximations, the final (stationary) value of the segregation index is independent of the rotating speed (in therange investigated); however, the values of this final segregation index is slightly larger with the single sphere model.This kind of simulations can be extended to the investigation of heat transfer between the two kinds of particles and to thefragmentation of the wood particles.