A Fluid Bed Dryer is designed for fast and uniform drying of powders, crystalsand medium sized pellets. The Fluid Bed Dryer finds application in Pharmaceuticals, Bulk Drugs, Dyes & Chemicals, Phyto-Chemicals, Catalysts, Food Products & Starch derivatives, Pesticides etc. Fresh air is drawn in by means of a fan. The air is then passed through a filter andheated to produce warm air by use of electric heaters. If the product contains asolvent or inflammable substances, the dryer must be operated using steam andprovided with a flame-proof motor. The heated air passes through the product container which has diffuser plates and a sieve. Due to the stream of air, the wetproduct gets fluidised. The material gets surrounded by the hot air and gets drieddue to heat transfer. Moist air passes through a filter bag and an exhaust duct. The Fluid Bed Dryer is not suitable for drying of liquids or pastes.
Advantages : In a Fluid Bed Dryer, the temperature is distributed uniformly throughout theproduct and the heat rate is very high. High production rates are achievedbecause of reduced drying time. As the product is in close contact with the dryingair at a low temperature and for a short duration, the physical and chemical properties of the product are not affected generally and hence the dryer can beeffectively used in the case of heat-sensitive products. As the product iscontinuously moving during the drying process, there is minimal lump formation or case hardening.