Flash evaporator

摘要

In a flash distillation apparatus, particularly for water, comprising a shell 5 enclosing an evaporation and a condensation section, feed liquid supplied through an inlet 6 (Fig. 2) is caused to be deflected twice on its way to the excess feed outlet 13, the first deflection being effected at 15 and the second by the arcuate arrangement of plates 17 which separate the evaporation section from the condensation section 9. Vapour evolved from the liquid is thus caused to pass through a spray of liquid before it reaches the condensation section 9 via the de-mister 8, and is thus freed of fine droplets of entrained liquid. Condensate is withdrawn through a pipe 14. Alternative means of deflecting the feed are also described, and in one of these (Fig. 5) the feed is divided by a plate 30 into two streams, each of which is separately deflected first by a deflector 15 and then by the curved walls 32, which may be extended, as shown at 34. In this modification two de-misters 8 are provided and condensate is withdrawn through a pipe 33a. In all cases a perforated distributing plate 35 (Fig. 6) may extend from the first deflecting means to the shell 5, to reduce the tendency of unflashed feed to rush from one end of the apparatus to the other when the apparatus is installed in a ship and the ship is in motion. The apparatus may operate under reduced pressure.