GB913024A - Sea water evaporator - Google Patents

Abstract

<PICT:0913024/III/1> <PICT:0913024/III/2> <PICT:0913024/III/3> A still for distilling sea water comprises a chamber 15 equipped with a bundle 22 of U-tubes 23 supplied with a heating-medium, and an upper chamber 16 containing a tubular condenser 39, a semi-cylindrical shroud 27, comprising two arcuate members, being mounted longitudinally beneath the heater so that there is an elongated opening 29 between the bottom edges of the members, which runs lengthwise beneath the tube-bundle, whereby circulation of the sea water over the tubes is promoted when the still is in operation. Sea water is supplied to the bottom of chamber 15, through a conduit (not shown), at such a rate that a slight amount passes over weir 34, and is withdrawn through pipe 36. A vacuum is maintained in the still by a jet pump (not shown) connected to the top of the condenser housing by pipe 58. The pump may be actuated by the cooling medium discharged from the condenser. The heating medium for tubes 23 may be water at about 180 DEG F., taken from the cooling jacket of an internal combustion engine. The steam from the boiling sea water passes through a wire mesh de-mister 20, mounted in the opening of partition 17, whereby entrained sea water is removed. The steam condenses on the tubes of condenser 39, the condensate is collected in trough 42, and flows into reservoir 44. The condensate is normally withdrawn through pipe 45 but it may be withdrawn through pipe 48 which has a valve operated by a salinity cell, if the salt content of the distilled water exceeds a predetermined value. The shell of the still may be made of a copper-nickel alloy or laminated fibre glass.