The use of a rotating fluidized bed to impose a
centrifugal field on nanopowders has some distinct
advantages over a conventional fluidized bed. The
centrifugal force acting on the agglomerates allows
fluidizing them at much higher gas velocities resulting
in a much higher gas throughput per unit area of
distributor, less entrainment of particles, and shallow
beds resulting in very small bubbles and therefore very
little gas-bypassing. Fumed silica, alumina, and titania
nanopowders have been successfully fluidized in a
rotating fluidized bed (Matsuda et al. 2004; Nakamura
and Watano 2008; Quevedo et al. 2006). A smooth
surface and appreciable bed expansion were obtained
when using APF nanopowders, but ABF nanopowders
such as Aeroxide titania P25 did not expand significantly
due to bubbling