Other fluidized bed drying techniques

Vibro-fluidization is used for cohesive, sticky solids or friable foods (Bahu, 1997) and for materials which would defluidize in a conventional plug flow drier (Reay and Baker, 1985). Vibration of the bed increases the drying rate due to an increase in the surface-to-bed heat transfer coefficient (Reay and Baker, 1985), particularly below minimum fluidizing velocity. A detailed treatment of the mechanisms of vibration fluidization is given by Reay and Baker (1985). 

Alternative methods of assisting the fluidization of difficult materials include the use of impellers in the bed to break up agglomerated particles, particularly to help initial fluidization in plug flow driers (Reay and Baker, 1985), and the use of a pulsed gas flow (Butcher, 1988). Bahu 

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