| 摘要 |
PURPOSE:To smoothly perform operations in water by a method in which lower- temperature fresh water than turbid water is supplied to the turbid water portion to produce a fresh water region in the turbid water and the range of vision in the turbid water section is made better. CONSTITUTION:Turbid water is taken out of the intake port 41 of a water suction tube 4 lowered to an operation range A, and the temperature of the turbid water is measured. Turbid water coming through the water suction tube 4 is put into a turbid water clarifier 1 for clarification, and the clarified turbid water is put into a cooler 2 to cool it to temperatures lower than the turbid water to obtain a fresh water having a higher density than the turbid water. The fresh water so cooled is discharged at a low flow rate from the outlet 31 of a low- temperature water supply tube 3 upward the operation range A. Since the operation range A has flowing fresh water, not turbid water, the range of vision in the turbid water region becomes better, and operations can be performed easily, exactly and safely. Also, since any chemical method is not used, there is no fear of pollution caused by chemicals for example. |
