GB834162A - Distilling apparatus - Google Patents

Abstract

<PICT:0834162/III/1> A flash evaporator in which heated feed water is introduced into a partially evacuated chamber to cause vapours to flash therefrom provided with means for removing a portion of feed water particles entrained in said vapours comprises an upwardly-facing opening communicating with the inlet, a cover overlying the opening in spaced relation thereto, said cover being in the path of movement of feed water introduced into the chamber, and being shaped to form the feed water into a curtain through which the vapours flashed at the opening are directed to pass, and a feed water outlet from the chamber located below said opening. In a preferred embodiment a two-stage flash evaporator for obtaining pure water from sea water comprises a first stage flash chamber 11 and a second stage flash chamber 12. Feed water at 170 DEG F. enters at an inlet 13 and passes to a plurality of vertically extending pipes such as 14 and 15 which terminate in flash openings 16 and 17 respectively which are fitted with covers 35 and 36 respectively so positioned that the water is formed into an annular curtain through which the flashed vapours must pass before moving through a wire mesh type demister 18 to the condenser 19, distilled water being removed through an outlet 21. Unflashed feed passes through an outlet 22 to the second flash chamber 12 and is similarly treated at a lower pressure. To obtain optimum conditions the circumferential area of the space between the end of the pipe and the top of the cover in the first stage should be one-fourth square inch per gallon per minute of flow of feed water, and one-half square inch per gallon of flow per minute in the second stage.