Abstract:
This work presents a contribution to the study of the problems of the magnetic separation. It is a 3D study of the existing magnetic, hydraulic and particle dynamic phenomena, the conception and the realization of a prototype intended to purify flowing water by the extraction of contained ferromagnetic fine particles. A numerical approach has been adapted and used in a 3D configuration. Such approach permits the taking into account the real effect of the acting magnetic and hydrodynamic actions applied on the particles. The study of the particle behaviour in water turbulent flow has permitted the identification of the parameters influencing on the separation performances. These parameters are considered as optimization keys of the proposed device. The optimization was based on the minimization of an objective function which is the distance between the central point of the capture element and the capture site of a given particle with initial conditions chosen as a function of the flow and applied field specifications. To implement the optimization approach, the Tabu search method has been used. The obtained results have shown that the best capture is obtained by a separator with three capture elements spaced between them by an angle of 120°. For a practical validation, a device has been realized and experiments have been achieved. The
flow regime is obtained by a pumping system. The capture elements are identical rectangular electromagnets. The particles are injected through an opening made in the entrance of the channel. For a quantitative validation, the particle motion and the captured particle build-up have been controlled by a camera. The quantitative validation has been achieved by using a Hall effect sensing device.
