METHOD OF MAKING SEA WATER INTO PLAIN WATER BY REFRIGERATION MAKING USE OF COLDNESS OF LIQUEFIED NATURAL GAS

摘要

PURPOSE:To save power and to recover high-pressure natural gas continuously by operating crystallization tanks, where sea water is refrigerated, intermittentaly by turns and by separating the vaporized natural gas from, ice crystals, hydrats, etc., and brine through a separating tank. CONSTITUTION:Sea water pumped up by a sea water pump is precooled through thawing tank 63 and after-heater 64 and charged into crystallization tank 61. On the other hand, boosted liquefied natural gas (LNG) enters crystallizer 64 by way of pipe 80 and is vaporized into natural gas (NG) to cool the sea water, thereby producing ice crystals and hydrates. Then, NG, ice crystals, hydrates, and brine are supplied via pipe 71 into separating tank 62, where the gas, brine and ice crystals plus hydrates are separated. Crystallization tanks 61 is carried out by batch operation with valves changed over to charge the sea water at a low pressure, so that high-pressure NG is recovered continuously.