| 摘要 |
PURPOSE:To improve the water saving efficiency by supplying a purifying agent to a water storage means according to measured contamination concentration or discharging part of washing water. CONSTITUTION:The contamination concentration of the washing water in the water storage tank 2 is measured by using a contamination concentration measuring means and the purifying agent is added to the washing water in a circulation path automatically from a purifying agent supply tank 5 according to the measured value to purify the washing water in the water storage tank 2 to a permissible value. Then at least part of the purified washing water is discharged by a water discharging means 7. At this time, all of the washing water in the water storage tank 2 may be discharged and only part of the washing water may be discharged and mixed with substitute fresh washing water for use. Consequently, cost merit which is the recovery of silver is obtained in addition to cost merit which is the saving of water, and contamination is reduced to improve the maintainability. |
