Multi-stage flash distillation process

Abstract

Abstract In a multi-stage flash distillation process, feed liquid to be distilled is progressively preheated by passage along a primary flow path in heat exchange relation with vapor zones of a series of successively staged flash evaporation chambers having flash liquid zones arranged in fluid communication. Flash liquid evaporated from the various flash liquid zones is replenished by feed liquid diverted from the primary flow path to and along secondary or by-pass flow paths leading directly to associated liquid zones. The liquid diverted to each secondary flow path has a temperature substantially equal to the temperature of the flash liquid in the zone to which it is diverted. When the liquid to be distilled contains scale forming materials which tend to precipitate at high temperatures, the liquid is preferably divided into a plurality of parts and at least one of the parts is treated with a suitable scale inhibitor. Feed liquid is tapped from the various parts to provide a plurality of streams of feed liquid which collectively comprise the primary flow path. At least some of the streams contain differing concentrations of scale inhibitor. Each stream is diverted from the primary flow path as aforedescribed when the preheated liquid in the stream attains a temperature slightly below the temperature at which scale deposition tends to occur.

Inventors

• 👤 A Spicacci

Bibliographic Details