The Thermal Vapor Recompression (TVR) is based on the same principle as the mechanical alternative, but uses only a portion of the resulting vapor for heating the system. The compression of the steam for heat recovery takes place in a steam jet pump. This is usually designed for a specific operating point and works on the jet pump principle. A certain amount of steam, the so-called motive steam, is required for the operation of a thermal vapor compressor. The resulting energy savings correspond in many cases in about an additional evaporator stage.
The main advantage of the Thermal Vapor Recompression is thus improved steam economy for a moderate investment cost, which is lower than that for an additional evaporation stage.