A model for estimating agglomerate sizes of non-magnetic nanoparticles in magnetic fluidized beds

The behavior of SiO2, TiO2 and ZnO non-magnetic nanoparticles and the effects of processing parameters on agglomerate sizes were investigated systematically in a magnetic fluidized bed (MFB) by adding coarse magnets. A mathematical model is developed based on energy balance among the agglomerate collision energy, magnetic energy, energy generated by turbulent shear and cohesive energy to predict the agglomerate sizes. The results showed that slugging of the bed disappeared and the measured agglomerate sizes decreased, so that the fluidization quality of non-magnetic nanoparticles was significantly improved by adding coarse magnets due to introduction of magnetic field. The average agglomerate sizes predicted by this model are in agreement with the experimental data.