Patent GB-983242-A (GB)
Title: Plant and process for the desalinization of saline water
IPC: B01D1/28
Filed: 1961-09-06
Abstract: 983,242. Distilling water. A. OSDOR. Sept. 6, 1961, No. 31946/61. Heading BIB. [Also in Division F4] Distilled water is produced from saline water by heating the saline water at a temperature in the vicinity of its critical temperature, i.e. above 374 C., under the critical pressure, separating water-vapour from the saline water by phase separation, further compressing the watervapour, and contacting the compressed watervapour with an immiscible heat-exchange fluid whereby water-condensate is obtained. The heat-exchange fluid, so heated, is then used to heat saline water by direct contact. Sea water at a temperature of about 17C. is drawn through pipe 1 and compressed to 220 atm. by pump P 1 ; the saline water then flows to a sprayer 8 at the upper end of heat-exchanger H 1 , which may be packed with granules of inert material, wherein the downflowing water is contacted with compressed humid nitrogen at 220 atm., introduced through injectors a 1 , a 2  and a 3  at different temperatures, whereby the water is heated to 356 C. The water is withdrawn from the bottom-section of heat exchanger H 1  and is passed through conduit 12 to a distributer in the bottom-section of heatexchanger H 2 , wherein the upflowing water is contacted with hot compressed paraffin, introduced into the top at a temperature of 408 C. The sea water leaving the top of heat-exchanger H 2  has a temperature just below 400 C., and it is now raised to 400 C. in fuel-heated coil 15, and introduced into separator S, where it separates into a vapour phase, a brine phase, and a solid salt phase. The vapour flows through conduit 21 into compressor C 1  where the pressure is increased to 245 atm. and the temperature rises to 415 C. The compressed vapour flows through conduit 24 into the lower section of heat-exchanger H<SP>1</SP> 2  where it is contacted with a countercurrent stream of compressed paraffin, introduced into the top at a temperature of 358 C. The water condensate, withdrawn from the top of heat-exchanger H<SP>1</SP> 2  at a temperature of 370 C., is passed through conduit 26 into the top of heat-exchanger H<SP>1</SP> 1  wherein it is cooled by contact with nitrogen, introduced through injector a<SP>1</SP> 1  at a pressure of 245 atm. and a temperature of 28 C. The water under pressure, withdrawn from the base of heat-exchanger H<SP>1</SP> 1  through conduit 28, is used to drive prime mover M 1 , and is then withdrawn as product through conduit I<SP>1</SP>. The residual brine is withdrawn from separator S through conduit 30 and is introduced into the top of heat-exchanger h wherein it is contacted with compressed nitrogen, introduced through injector b 1  at a temperature of 19 C.; some nitrogen is also through introduced at a higher temperature through injector b 2 . The water of the hot brine vaporizes almost completely into the nitrogen, and the mixture of steam and nitrogen flows through conduit 54 to compressor C 4 , whence it is introduced through injector a 1  into heat-exchanger H 1 . Salts are withdrawn from the base of the heat-exchangers H 1 , H 2  and h, and the separator S. The paraffin withdrawn from the base of heat-exchanger H<SP>1</SP> 2  is heated to 408 C. in coil 15<SP>1</SP> and then expanded from 245 to 220 atm. in prime mover M 3 . The paraffin then flows through conduit 34 to heatexchanger H 2 . After heating the sea water, the paraffin flows through conduit 36 to pump P 2  where it is compressed to 245 atm., before being delivered through conduit 39 to heat-exchanger H<SP>1</SP> 2  where it cools the water-vapour from separator S. About 90% of the nitrogen leaving the top of heat-exchanger H 1  is passed through conduit 40 to compressor C 3 , where it is raised to 28C. by adiabatic compression, before being supplied via injector a<SP>1</SP> 1  to heat-exchanger H<SP>1</SP> 1 . The remainder of the nitrogen withdrawn from the top of heat-exchanger H 1  is supplied through conduit 40<SP>1</SP> to heat-exchanger h. Some of the nitrogen is withdrawn from the middle of heat-exchanger H<SP>1</SP> 1  through conduit 44, and is used to actuate prime-mover M 2 . The nitrogen discharged from prime-mover M 2  is introduced into heat-exchanger H 1  through injector a 5 . The nitrogen leaving the top of heat-exchanger H<SP>1</SP> 1  passes through heating-coil 49 and is then used to actuate prime-mover M 4  before being introduced, via injector a 2 , into heat-exchanger H 1 . Mercury may also be used, in three separate heat-exchange cycles, as heating- and cooling-medium. Tar and air are are also mentioned as heat-exchange fluids.