| 摘要 |
PURPOSE:To stop corrosion from developing due to sea water and improve the safety and lifetime of a machine by providing a fresh water containing chamber, feeding pressurized fresh water into said chamber, preventing the spray of sea water from colliding against the surface of a machine, and covering the surface of said machine with said fresh water. CONSTITUTION:Fresh water is fed into a fresh water chamber R1 through a fresh water feed pipe 10, and a flow regulating valve 16, and the pressure in the fresh water chamber R1 is set slightly higher than the pressure maintained in a runner back pressure chamber R2. Accordingly, sea water in the runner back pressure chamber R2 does not flow into the fresh water chamber R1. The fresh water in the chamber R1 reaches a drain chamber R3 through a gap between a packing 14 and the outer periphery of a main shaft 3, and discharged out of equipment through a drain pipe 13. Therefore, the spray of sea water which accelerates corrosion, can be prevented from being splashed against a metal case 5 and a bottom plate 5-1. A salt concentration detector 9 is housed in the fresh water chamber R1, to adjust the opening of the flow regulating valves 16, 17 in accordance with the concentration of salt, and control the quantity of feeding fresh water, enabling the control of the concentration of salt in the chamber R1. |
