| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a washing method for ultrapure water production system, removing metal impurities from an ultrapure water production system with high efficiency and shortening washing time. <P>SOLUTION: Hydrochloric acid is added into a primary pure water tank 21, circulated in a heat exchanger 23, an ultraviolet ray oxidation treatment apparatus 24, bypass lines 30, 31, 32, a flow path 6a, a use point 4 and a flow path 6b by a pump 22 in the order and then placed under an immersed state. Subsequently, the inside of the tank 21 is filled with primary pure water. Next, the primary pure water is passed in the same order, and washing liquid is discharged from the terminal of the flow path 6b to the system outside. In performing pickling, a degassing apparatus 25, an ion exchange resin tower 26, and a UF apparatus 27 are bypassed. By bypassing the UF apparatus 27, extrusion washing time of hydrochloric acid-containing liquid is shortened. <P>COPYRIGHT: (C)2011,JPO&INPIT |
