ABSTRACT
Very vigorous mixing of the fluidized particles takes place just the distributor, and heat and mass can be exchanged very effectively between particles and the fluidizing gas because of the large surface area of the particles. The gas fluid bed is characterized by having good heat transfer properties between the fluidized layer and heating or cooling surfaces. The height of the fluidized layer is controlled by a weir over which the dried material freely flows. The fluidizing air is heated and led into the plenum chamber to the fluid bed. An air distributor ensures that the fluidizing air velocity is even throughout the fluidized layer and that all material is properly fluidized. Small lumps of the feed can be fed to the top of the fluidized layer by means of a rotating product spreader. In a stationary fluid bed dryer, violent agitation of the particles takes place in the fluidized layer because of gas bubbling.
