GB1212632A - Water purification - Google Patents

Abstract

1,212,632. Degasification and distillation of water; direct-contact condensers. ALUMINUM CO. OF AMERICA. 19 March, 1969, No. 14540/69. Headings BIB and B1M. Water which contains non-condensible gas (e.g. absorbed air) is purified ;by feeding it into evaporator 26 (Fig. 4) which is maintained at sub-atmospheric pressure so that partial evaporation of the water and liberation of the gases take place; the vapour/gas mixture flows through passage 30 into the head 37 and chambers 38 where the gaseous mixture is formed into capsules each surrounded by distilled water, pumped into head 37 through pipe 44, and the capsules are forced down through chambers 38 and 54 wherei nthe water-vapour condenses, the gases being released from the liquid into the atmosphere when the capsules reach basin 39. Some of the distilled water is withdrawn from basin 39 through pipe 21, and the remainder is pumped back to head 37 via cooler 45. Heat may be added to the feed water in basin 24. Unevaporated water flows out of evaporator 26 through leg 28. Head 37 contains a perforated liquid-distributing plate, or packing. If mercury is used as encapsulating-liquid, the height of the apparatus can be reduced. In the apparatus shown in Fig. 10, the vapours from the evaporator (not shown) are first passed through condenser 31 in which a large proportion of the water-vapour is condensed, and the residual mixture of watervapour and gases flows into column 83 where it is formed into a foam with oil introduced through pipe 44. The foam is forced down the column and compressed by gravity, and the water-vapour condenses. When the mixture reaches basin 39, the gases are released and the condensate separates from the oil. Distilled water, to which a foam-promoting detergent has been added, may be used as condensing-medium in place of oil.