Vapor compression distillation system and method

摘要

Distillation system having an evaporator/condenser core with heat transfer plates welded together along their edges to form alternate boiling and condensing chambers. Feed liquid is supplied to the boiling chambers through a pair of heat exchangers which preheats the liquid and a steam stripper utilizing ceramic pieces to remove gasses from the liquid. Vapor from the boiling chambers is compressed and delivered to the condensing chambers where it is condensed and gives up its heat to the liquid in the boiling chambers. Pumps positioned between the two heat exchangers draw the condensed product and unvaporized feed liquid containing dissolved solids from the evaporator/condenser and circulate them through the heat exchangers to transfer heat to the feed liquid. The level of the liquid in the boiling chambers is maintained by means of a sight glass and a photosensor which monitors the level of liquid in the sight glass and controls the operation of a valve in the feed line to control the amount of feed liquid delivered to the boiling chambers. The distilled product is collected in a manifold at the output side of the condensing chamber, and the level of the product in the manifold is maintained by means of another sight glass and sensor which controls the operation of a valve in the product line downstream of the two heat exchangers. Pressure in the boiling chambers is monitored by means of a manometer tube with level switches which control the application of heat to the chambers and shut the system down in case the pressure gets too high or too low. The heat exchanger has corrugated plates which are formed by a rolling process and clamped together, with seals bonded to the plates defining counter-flow chambers between them for the different liquids.