Multistage evaporator for desalination of seawater - in which throughput can be halved without alteration of press. and temp.

摘要

In a multistage flash evaporator, a channel in the form of a crevice connects the feed point of a stage to the vapour offtake point. The stage has two sections. One has a cross-section rsembling that of a snail shell and evaporation occurs here. The other is sack-shaped and is primarily a transport zone for concentrated liquor. The evaporator is esp. used for deslination of sea water. The throughput of the unit can be reduced by 50% of the design rate without variation of stage pressures and temps. No mechanical regulation of flow in the unit is necessary. Vapour is produced differentially so that no disentrainment equipment is needed and the press. drop in the vapour offtake line is minimal. The residence time in the unit is short.