Magnetofluidization of fine magnetite particles

Abstract

In this study we investigate the behaviour of a fluidized bed of fine magnetite particles as affected by a crossflow uniform magnetic field. Due to the small particle size (35 microns), the fluidized system displays a typical Geldart A fluidization behaviour in the absence of an external field, i.e. natural van der Waals forces are able to stabilize fluidization in a short interval of gas velocities above the minimum fluidization velocity. The effect of the external field is to delay bed stability to higher gas velocities. Mechanical measurements on the magnetofluidized bed have been carried out using the Seville Powder Tester, which allows us for an accurate control of gas flow, and measurement of gas pressure drop across the bed and bed height. The tensile strength of the magnetically stabilized bed has been tested as a function of the gas velocit