| 摘要 |
PCT No. PCT/GB85/00048 Sec. 371 Date Oct. 2, 1985 Sec. 102(e) Date Oct. 2, 1985 PCT Filed Jan. 31, 1985 PCT Pub. No. WO85/03459 PCT Pub. Date Aug. 15, 1985.To control build-up of paint in the water tank an alkaline liquid containing NaOH is added in quantities to maintain a pH not substantially less than 9, thus preventing corrosion, and a hydroxide ion concentration not exceeding 0.01M. The additive is introduced by a metering pump under the control of a programmed timer over a seven day cycle. Over half the amount to be added in the cycle is introduced as a single discrete dose (preferably before a weekend) and the rest as smaller doses at intervals. |
