Principle:
• Climbing Film Evaporator Utilizes the principle of forming a thin film of liquid that climbs up the walls of a heated tube, enhancing evaporation due to increased surface area and reduced film thickness.
Construction:
Vertical Tubes: Long, vertical tubes where the liquid forms a climbing film.
Steam Jacket: Surrounds the tubes, providing the heat necessary for evaporation.
Feed Inlet: Introduces the liquid at the bottom of the tubes.
Vapor Outlet: For removing the evaporated vapor at the top.
Concentrate Outlet: For removing the concentrated liquid.
Working:
The liquid is introduced at the bottom of the vertical tubes.
As the liquid heats, vapor bubbles form, causing the liquid to rise and form a thin film on the tube walls.
The film climbs up the tube due to the vapor's upward force, evaporating along the way.
Vapor is removed at the top, and the concentrated liquid exits through a separate outlet.
Uses:
Concentration of heat-sensitive liquids in the food, pharmaceutical, and chemical industries.
Evaporation of solvents from solutions in the production of extracts and concentrates.
Merits:
Efficient heat transfers due to the thin film and large surface area.
Suitable for heat-sensitive materials due to short residence time.
High evaporation rates.
Demerits:
Complex design and operation.
Requires precise control of feed rates and temperatures.
High initial investment.