Thin Film Evaporation - The Technology
For thermal separation via distillation, part of the product to be treated is evaporated using heat, and condensed separately. Many organic substances, e.g. vitamins, flavoring agents or pharmaceutical intermediates, however, become damaged even at low temperatures, e.g. due to thermal decomposition, polymerization and side reactions which have a negative influence on the quality of the final product. There is an increasing loss of quality caused by rising temperature and duration of thermal stress. By means of extreme reduction of operating pressure and special design, the evaporation temperature and duration of thermal stress of a product can be reduced considerably and the quality is greatly improved.
Thin Film Evaporators
The UIC Thin Film Evaporators normally operate within a pressure range of 1 mbar and 100 mbar. The product to be treated flows along the inside wall of the evaporator as a liquid film from the feed point to the discharge point. The residence time in the vessel is very short reducing thermal stress to a minimum. We have developed a unique wiper system for the operation inside the evaporator supporting even distribution of liquid on the evaporator surface and ideal mixing of the product which flows downwards. This means that volatile substances are continuously brought to the film surface and evaporate more efficiently. Heating of the evaporator is made via heat transfer medium, e.g. thermal oil or steam. The evaporated compounds are condensed in an externally positioned condenser.
Thin Film Evaporators are used in the of mentioned vacuum range or in case of high viscous residue and also solids containing residue. Our wiper system can be modified to a rigid blade system if required.