Powder Technology, Vol.183, No.2, 152-160, 2008
Hydrodynamic study of a liquid/solid fluidized bed under transverse electromagnetic field
This work is devoted to the study of liquid/solid fluidization subjected to an external transverse electromagnetic field (either steady, or periodic orientation changing), in the range 0-48 000 A m(-1). The porous media is constituted by a mixture of ferromagnetic steel shots and non-magnetic zinc particles with mass fractions from 10 to 100% of ferromagnetic material. Key parameters of the bed (superficial velocity, pressure drop, porosity, particle movement) are used to describe the influence of electromagnetic field and mass fraction on fluidization and bed behaviour. Whereas changing orientation fields do not produce any positive effect, steady fields provide peculiar and interesting properties to the media through the drawing of state diagrams. Thus Magnetic Stabilized Fluidized Bed (MSFB) can be obtained and the stabilization zone is increased by a factor 6 when ferromagnetic mass fraction goes from 10 to 75%. Such stabilizing effects improve bed performances of some applications, such as electrochemical cementation. Besides typical remanant porosity effects are highlighted. (c) 2007 Elsevier B.V. All rights reserved.