Optimisation du profil de l'induction magnétique Pour application de la séparation des particules non homogènes en voies sèche et humide.

Abstract

The presented work in this thesis presents a contribution to the process of magnetic separation problems. This study based mainly on study and realization of an eddy current magnetic separator with a horizontal drum dedicated to ferromagnetic, diamagnetic, paramagnetic and conductive particles separation in dry and wet ways. A two-dimensional approach based on the model equations coupling governing the existing phenomena (magnetic, hydraulic and particle dynamics) has been developed and used to treat the magnetic separation problem. In order to achieve a successful separation, optimization of the proposed separator has been accomplished. This optimization requires the key parameters identification on which the separation depends. Such identification requires a resolution and analysis of the separation problem taking into account the existing phenomena evolution. The optimization carried out is based on the minimization of an objective function which is the distance between the end point of the separation and a chosen position in a way to take into account the specifications of the applied magnetic field and the velocities of the belt and liquid. For this, the Particle Swarm Optimization (PSO) method was used. In order to validate the approaches and the developed and implemented calculation codes on one hand, to verify the theoretical analysis carried out and the performances of the designed separator and to define the limits of its use on the other hand, experiments have been carried out in dry way. The device consists mainly of a drum with a succession of identical permanent magnets successively arranged with alternating polarity and driven by a motor controlled by a variable speed drive. Transport of the treated material is ensured by a conveyor belt running independently of the drum. The qualitative comparison of theoretical and experimental results showed a great concordance which validates the different approaches and performed calculations.