| 摘要 |
PURPOSE:To obtain desalted water of low salt concentration and low concentrated water of high salt concentration by a small area of membrance at the same time, by supplying sea water to the primary desalting apparatus having reverse osmotic membrance of high desalting rate under pressure and then, supplying produced primary desalted water to the secondary desalting apparatus having reverse osmotic membrance of low desalting rate under back pressure. CONSTITUTION:The sea water 3 pumped up by the pump 2 from the pipe 1, is aggregated and precipitated by the prcipitator 4 and is filtered by the filter 7 9 after injecting the flocculant 5 and Cl26. Next, the water 3 is pressurized by the pump 15 after injecting the acid 10 and inhibitor 11 and is sent to the primary desalting apparatus 17 and then, 800-1000ppm (TDS) of the primary desalted water 20 is obtained by treating with a high desalting rate at less than 30% recovery. Then, the water 20 is supplied to the secondary desalting apparatus 21 under 7-10.5kg/cm<2> of back pressure and the secondary desalted water 27 having less than 500 ppm of salt concentration, is obtained by carrying out desalting treatment at less than 30% recovery and then, is recovered as the suitable drinking water 29 through the mineralizer 28. On the other hand, CO2 is exhausted from the concentrated water 22 by the decarboxylation column 23 and the water 22 is recovered from the duct 24. |
