| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for operating the production unit of pure water, in which a water quality control system being inexpensive and easy in operation and maintenance is adopted. SOLUTION: In a method for operating the production unit of pure water, in which at least an anion-exchange tower filled with a strong basic anion- exchange resin or a mixed bed tower filled with both the strong basic anion- exchange resin and a cation-exchange resin is contained, when water-passing is performed in a descending flow, electric conductivity or pH of water-passing in the position corresponding to the range of the part upper by 10-50 cm from the bottom of the resin filling layer of the inside of the anion-exchange tower or the mixed bed tower is measured. When water-passing is performed in an ascending flow, electric conductivity or pH of water-passing in the position corresponding to the range of the part lower by 10-50 cm from the top part of the resin filling layer of the inside of the anion-exchange tower or the mixed bed tower is measured. At a point of time in which the measured value is quickly changed, water-passing is stopped. |
