An Agitated Thin Film Evaporator (ATFE)/ Agitated thin Film Dryer (ATFD) consists of a cylinder (shell) covered with heat-jacket, a rotating assembly of blades mounted coaxially within the cylinder, a motor that drives the blades and a bottom cone to collect the concentrate or the powder.
ATFE / ATFD are ideally used for very high viscous liquids where falling film, rising film or forced circulation type evaporator cannot function, and the aim is to achieve slurry / powder / cake (Dry Solids). Tangential entry of the liquid to the wall of the vessel ensures centrifugal action and uniform distribution of the liquid. The wiper blades mounted on the rotor continuously wipes the feed that is traveling along the inside wall. The feed starts evaporating and the wipers remove deposition of product on the inner wall and try to maintain the heat transfer area clean.
The vapours that are generated inside the vessel travel to the center where they get condensed along the condenser tubes. Cooling water is circulated in condenser shell as coolant.