Freeze drying prod. in adsorbent fluidised bed - is speeded by incorporating inert solid particles in bed material

摘要

The prod. is mixed into a fluidised bed of a material which is adsorbant of water vapour. The temp. of the fluidised bed, and the partial pressure of water vapour in the chamber in which drying takes place, are regulated to obtain sublimation of the frozen water contained in the prod. In this addn., finely divided solid particles of an inert material are incorporated into the fluidised bed, intimately mixed in the adsorbant material and the prod. to be dried. The inert material pref. has a fluidisation min. speed close to that of the adsorbant material. The average particle size of the inert material is pref. less than that of the adsorbant material. The density of the inert material is pref. greater than that of the adsorbent material. The fluidised bed pref. includes approximately equal volumes of inert and adsorbent materials. Microballs of glass are pref. used as the inert material.