GB937623A - Improvements in or relating to the evaporation of sea water - Google Patents

Abstract

<PICT:0937623/III/1> Sea water is pumped through condensers 21 to 31, wherein it is heated to 152 DEG F. by the vapours from multi-stage flash evaporator 20-30, the water is next raised to 172 DEG F. in heat-exchanger 50 and passes through valvedline 34 into flash chamber 30 wherein it is substantially de-aerated and partially evaporated; the water is then pumped through line 80 into evaporator chamber 10 which is connected to heat-exchanger 11, the water being circulated by pump 16 through heat-exchanger 11, and back to chamber 10. While in heat-exchanger 11 the water is heated by steam withdrawn from chamber 10 and compressed by compressor 12, the compression ratio not exceeding 1,25. Non-condensible gases are sucked out of condensers 21-31 and from the condensing side of heat-exchanger 11 by steam-ejector 40 through line 42. The exhaust steam discharged from ejector 40 and from turbines 14 and 18, which actuate compressor 12 and pump 16 respectively, is used to heat the water flowing through heatexchanger 50. A small fraction of the water circulating through pump 16 is passed through valved line 84 to flash chamber 28. The residue from flash chamber 28 is introduced into flash chamber 26. The residue passes through chambers 24, 22 and 20, and is discharged by pump 102. The condensate from heat-exchanger 11 is passed through line 32 to condenser 29 where it mixes with the distillate from chamber 28 as well as that from condenser 31. The distillate flows through condensers 27, 25, 23, 21, and the product-i.e. distilled water-is withdrawn from the system by pump 100.