Forced circulation evaporators handle viscous, scaling, and salting liquors effectively; which of the following represents this type ?
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Answer: C. Agitated film evaporator
Explanation
Agitated film evaporators use mechanical wiper blades to spread viscous and scaling liquids into a turbulent thin film. Mechanical agitation prevents stagnant zones and fouling on heating surfaces during difficult concentration duties. Viscous, scaling, and salting liquors are processed efficiently because blades continuously shear the liquid film. Evaporator designs vary from vertical calandria tubes to mechanically aided wiped film devices. Thin-film evaporation minimizes residence time and thermal degradation for sensitive or highly viscous fluids. Wiper blades maintain high turbulence and rapid heat transfer coefficients across the heated cylindrical wall.
Pharmaceutical and polymer industries rely on agitated film evaporators to concentrate highly viscous extracts. Handling heat-sensitive products prone to fouling requires mechanical thin-film evaporation technology. High equipment cost is offset by successful processing of materials that clog conventional evaporators. Long vertical evaporators rely on natural or forced liquid circulation rather than mechanical wiper blades. Horizontal tube evaporators are typically used for desalination rather than highly viscous agitated film duties. Calandria vertical tube evaporators lack mechanical agitators and struggle with extremely viscous scaling fluids.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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