PERFORMANCE OF FALLING FILM PLATE EVAPORATORS

摘要

Evaporation is merely separation of dissolved solids from water, by the application of thermal energy. Norbert Rillieux did the most revolutionary work in the field of juice evaporation by inventing Multiple Effect Evaporators. He also described the effect of lowering BPT (boiling point elevation) by application of vacuum. Classification of evaporators can be done as: Tube Evaporators & Plate evaporators. Tube evaporators are further divided into: Robert Evaporators & Thin-Film Evaporators (rising film & falling film). The plate type of evaporators the coil usually made up of copper or aluminium is embedded in the plate so as so to form a flat looking surface. It was found out that besides thermal efficiency, falling film plate type evaporators have better juice quality and in that way quality of final product i.e. sugar, considering its color. Falling film evaporators also have an advantage of ability to work at low temperature difference.