In multiple effect Thermal Vapour Recompression (TVR) evaporators, the evaporative energy in the first effect is supplied from a steam injector that compresses vapour from one of the associated effects to a higher temperature.
The heating medium in any subsequent effect is the vapour generated in the previous effect. Vapour from the final effect is condensed by heating the incoming product and in the condenser. The hot condensate can be reused for boiler water and/or CIP liquid.
The choice between Mechanical Vapour Recompression and Thermal Vapour Recompression depends on the local prices of different energy sources, the possibility of using the condensate, the depreciation of the capital cost (including capital cost of the building), and the cost of product losses during cleaning.