Electrification study in dielectric material fluidized beds for different fluidization regimes

The interest in electrostatics has grown in the past decades, because it has been recognized both as a source of the many problems in the chemical industry and as a useful tool in the powder industry. These materials are manily of particles dielectrics, which can acquire an electrical charge by various procedures. This influence may be undesirable (explosions) or beneficial (mineral separation, mixing and powder characterization). In this paper, the main parameters intervening in electrofluidodynamics phenomena during the fluidization process have been analyzed. The electrification degree was measured by the potential difference between various circular electrodes placed on the column wall and the electrode central. This study shows that the triboelectrification of granular dielectric materials is associated to the agitation degree (relative velocity gas, bubbles size and particles diameter), to the humidity rate and the fluidization regime (bubble or slugging). The results obtained show that in the splash zone exits more electrification on the column wall that in the center one and that, this electrification is a function linear to the gas relative velocity for the bubbling regime while. Also, the electrification degree increases with the particle diameter.