Spray Dryer

Spray drying is a method of producing a dry powder from a liquid or slurry by rapidly drying with a hot air. The pump-able feed is pumped to a nozzle or atomizer. The atomizer or nozzle atomizes the pumped feed. At the same time hot air is passed through air distributor into drying chamber. This hot air comes in contact with the atomized feed particles and removes moisture. The dry powder drops down at chamber cone at bottom and collected. Air leaves the drying chamber and is passed through cyclone and or bag filter / wet scrubber. Alternatively powder can be collected at the outlet of cyclone separator. Spray Dryers can be of co-current or counter current type. Also the design of chamber varies according to product and operating temperature. Spray Dryers are used in foods, chemicals, ceramic and pharmaceutical sectors. If product is oxygen sensitive or flammable then nitrogen gas is used.