| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make the concentration of persulfuric acid sufficiently high to be repeatedly recycled, and to determine the life of a solution in a persulfuric acid supply apparatus. <P>SOLUTION: The sulfuric acid recycling type cleaning system has: a cleaning tank 1 for cleaning a material 30 to be cleaned using a persulfate solution 2 as a cleaning liquid; electrolytic tanks 10a, 10b for electrolyzing the cleaning liquid discharged from the cleaning tank to generate persulfate ions from sulfate ions contained in the cleaning liquid to produce a persulfate solution; and circulation lines 4, 4a, 5, 5a for circulating the persulfate solution between the cleaning tank 1 and the electrolytic tanks 10a, 10b. The system further has impurity amount measuring means 16, 17a-17c, 18 for measuring the amount of impurity accumulated in the persulfate solution accompanied by cleaning. The sulfate solution is repeatedly used to regenerate the persulfate solution using an electrolytic apparatus on site, so as to use it for cleaning. Moreover, the life of the persulfate solution is accurately determined, thereby preventing the cleaning action from being lowered. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
