| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an effective method for sterilizing bacteria propagating in the ultrapure water feed piping of an ultrapure water manufacturing apparatus. <P>SOLUTION: The ultrapure water feed piping 7 of a secondary pure water system is provided with an ozone/carbon-dioxide gas injection device 10 for injecting carbon dioxide gas and ozone, and bypass piping 9a, 9b connecting the inlet side piping 7 of an ion exchange device 5 and the outlet side piping 7 of an ultrafiltration device 6. Carbon dioxide gas and ozone are injected from the ozone/carbon-dioxide gas injection device 10 into the ultrapure water feed piping 7 and made to flow into the ultrapure water feed piping 7 while bypassing the ion exchange device 5 and the ultrafiltration device 6. After completing the sterilization operation, the treated water is introduced in an ultraviolet irradiation device 4 to decompose ozone, and then discharged. <P>COPYRIGHT: (C)2003,JPO |
