Multiple Effect Evaporators
Falling Film/ Rising Film Evaporators
Comprises a vertical shell-and-tube heat exchanger (Calendria) with a liquid distributor unit and a vapour-liquid separator. Its ease of operation and time-efficiency makes it one of the most widely used evaporators. The product is fed into the top distributor unit. The liquid from the distributor unit uniformly falls through the tubes forming a consistent layer across its walls.For distribution, stationery distributor and spray nozzles also can be used. The steam is injected through the inlet which heats the falling liquid and evaporates the liquid partially. The vapour and the liquid flows downward into the bottom of the calendria. The residual liquid accumulates at the bottom on the tube side, and the vapour travels through a duct into the attached vapour-liquid separator. The vapouris let out from the top of the separator, and the residual liquid, at the bottom,is fed back into the distributor unit with help of a pump, until the desired concentrationis arrived at.
Agitated Thin Film Dryer / Evaporator
Due to its inherent design features, it is ideal for thermal treatment of solutions and heat sensitive products, where reduced operating temperatures and vacuum operating pressures are desirable. The typical Agitated Thin Film Evaporator consists of a tubular heat transfer area with an external heating jacket and a fast-revolving, inner rotor with flexible or rigid wiper elements. The driving speed is adapted to the product being handled, its particular specifications and task.
The feed product is evenly distributed by the rotor and its wipers over the heating surface, forming a thin liquid film of uniform thickness. Highly turbulent swirls are produced at the tip of the rotor blades and wipers with intensive mixing and agitation of the product, as it comes into contact with the heating surface. This assures excellent heat transfer combined with constant renewal of the product film and provides an even heating and short residence time of the product through the heated zone.
