Flash evaporation for treatment bath recovery - using vapour recompression and recycle to balance evaporator load

摘要

A vapour recompression evaporator system has a housing surrounding a vapour chamber and means of introducing the feed. An extended surface inside the chamber, a compressor in teh vapour outlet is used to recompress the vapour and recover its energy and hold the chamber at reduced pressure. A compressor is in two parts, one rotating, the other on the stationary flights to effect the recompression. A jacket surrounds the chamber in which the vapour is recondensed to heat the liquid and provide the heat of evapn. Means of returning reconcentrated liquor back to the process and means of recycling condensed vapour as wash liquir are provided. Used esp. for use in reconcentrating plating solns. It permits recycle of the valuable metal ions etc. in the soln. and also provides a closed system for the wash liquor which reduces material usage, and effluent. Main problem with existing systems is control of recycle quality and the problem of keeping the system in balance when the process load varies. The system fulfills these functions, gives reduces mechanical maintenance and permits a more compact compressor construction.