(232e) Theoretical Studies of Nanoparticle Fluidizations

Different nanoparticle beds have been successfully fluidized in the form of agglomerates with the assistance of high superficial gas velocity, mechanical vibration, acoustical agitation, or magnet stirring by many researchers. The minimum fluidization velocities reported range from as low as 0.2 cm/s to as high as 6 cm/s. Some direct measurements of the size of the fluidized nanoparticle agglomerate have also been performed by a few researchers, showing several hundred micron nanoparticle agglomerates. However, until now most investigation of nanoparticle fluidizations focused on experimental studies. The mechanism of nanoparticle fluidization is not clear at all and still remains untouched. In this study, a parametric model has been developed to predict the fluidization behavior of nanoparticle beds. A minimum energy criterion (MEC), which is required to promote the fluidization of nanoparticle beds, has been proposed. The effect of different types of energy inputs such as mechanical vibration and acoustical agitation on minimum fluidization velocity and agglomerate size are also investigated.