In the field of thermal separation and concentration technology, evaporation plants are widely used for concentration of dilute feed to the desired percentage of dissolved solids.
In falling film evaporators the liquid product usually enters the evaporator at the top of the evaporator. In the head, the feed is evenly distributed into the heating tubesand flows downwards at boiling temperature and is partially evaporated.
Principle follows the vertical shell-and-tube heat exchanger concept in which feed is on tube side and steam is on shell side.
Need Of Evaporation :
- Reduces transportation cost
- Reduces storage cost
- Recovery of solvent
- Better microbiological stability
- Reduces deteriorative chemical reactions
- Prepare for the next unit operations- drying, crystallization etc.
The liquid to be concentrated is fed to the top of the evaporator and distributed in such a way as to flow down the inside of the tube walls as a thin film. As a result,the liquid film starts to boil due to the external heating of the tubes and is partially evaporated. The downward flow, initiallycaused by gravity, is enhanced by the parallel downward flow of the vapour formed. Residual film of liquid and vapour is separated in the lower part of the Calendria and in the vapor-liquid separator.
- Single or Multi-stage systems
- High heat transfer coefficients
- High Vacuum & Low temperature process for temperature sensitive products
- Low batch time
- Low pressure drop
- High Evaporation Rate
- Integrated Re-circulation Process