| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform the functions of iron ion and ozone sufficiently by a method wherein a closed circuit or a circulation circuit, including a heat conducting unit, is formed in one part of a cooling water circuit while circulation water, iron ion and ozone are supplied into the circulation circuit to circulate the mix water of them, and form a protecting coat on the inner surface of the heat conducting unit. SOLUTION: A circulation circuit C includes a part of a cooling water circuit A and is constituted of a cooling water passage 3 of a heat conducting part 2, a supplying pipe 13 and a discharging pipe 14. Clean water is supplied into a circulation circuit C through a circulation water supplying passage C1 and. thereafter, an opening and closing valve 21 is closed to retain the circulation circuit C in the condition of a closed circuit. Then, iron ion and ozone are mixed into the clean water and these substances are circulated through the circulation circuit C for a predetermined period of time. In this case, a PH value is regulate so as to be 5-7. Accordingly, slime, adhered to the boundary wall of the heat conducting unit 2 upon the circulation, is oxidized by the sterilizing power of ozone and iron oxide coat is formed on the boundary wall. According to this method, a period of time, in which predetermined amounts of iron ion and ozone are contacted with the heat conducting unit 2, can be set arbitrarily.</p> |
