Mechanical and Thermal Vapor Recompression in liquid food concentration by evaporation

摘要

The vapor recompression technique consists in increasing the pressure of the vapor produced in a liquid food evaporation process, so that it can be re-employed as heating fluid in the process itself. This results in substantial savings of live steamconsumption and therefore of fuel costs; other remarkable advantages include reduction of both condensation water requirements and environmental impact. Mechanical Vapor Recompression (MVR) involves the use of a compressor, driven by an external source of mechanical energy. Thermal Vapor Recompression (TVR) is performed by means of a steam ejector, in which the low-pressure vapor is sucked and compressed by high-pressure live steam. In this paper, some thermodynamics and engineering aspects of both MVRand TVR are discussed and some examples of process optimization criteria and costs estimation are presented.