| 摘要 |
1,143,392. Multi-stage flash evaporators; desalination of sea water. APPLIED RESEARCH & ENG. Ltd. 3 March, 1966 [4 March, 1965], No. 9358/65. Heading B1B [Also in Division F1] Liquid, e.g. sea water or other brine, is submitted to distillation in a multistage flash evaporator 5, 6, 7, in which each flash chamber is associated with heat-exchange tubes 14, 15, 16 on the outer surface of which the flashed vapours are condensed thereby heating feed liquid flowing through the tubes, provision being made so that some of the vapour from an intermediate flash chamber 6 is conducted to a turbine 12 which drives an alternator 11. Turbine 12 is connected to (or forms the low pressure end of) turbine 13, the latter being supplied with steam from boiler 1. Brine, supplied through line 20, is preheated in heatexchangers 15 and 16, and is then introduced into flash chamber 6. The brine is next pumped through heat-exchanger 14 in heater 4 where the brine is further heated by steam discharged from turbine 13; and the brine is then fed into flash chamber. Part of the steam discharged from turbine 12 is passed via line 17 into the condenser casing of heat-exchanger 16, and the remainder flows to condenser 10. Distilled water is withdrawn from the system through lines 19 and 21. Brine is discharged from chamber 7 via line 22. The condensate formed in heater 4 is returned to boiler I via heater 3 which is heated by steam bled from turbine 13 by line 18. If desired, the condensate from condenser 10 may be pumped through line 19a to heater 3 and boiler 1. In a modified plant, turbine 13 is eliminated and the steam from boiler 1 is passed directly to heater 4; and, instead of driving an alternator, turbine 12 compresses vapour withdrawn from one of the flash chambers, and the compressed vapour is also supplied to heater 4. It is stated that the vapour from the intermediate distillation stage may be expanded in an internal-combustion engine (e.g. a gas turbine).
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