| 摘要 |
PURPOSE:To prevent semipermanently corrosion and contamination of the shell plate by covering said plate with a copper-base metallic material and maintaining the protective current value only during sailing at an optimum value based on specific potential thereby effecting electrolytic protection. CONSTITUTION:The submerged part of a shell plate 1 is covered by a copper or copper alloy material 2. A power source 3 in the ship and an electrode 4 which is hoisted up and down by a hoisting device 6 are connected by a conductor 5 and the material 2 and the power source 3 as well as one end of a control device 8 are connected by a conductor 7. The device 8 detects the sailing and stop of the ship, commands the device 6 and receives the signal from a reference electrode 9 provided in part of the plate 1. The power source 3 turns off and the device 6 lifts the electrode 4 from the sea when the ship calls at a port. Then the material 2 elutes to generate an effect of preventing contamination. When the ship leaves the port, the device 6 casts the electrode 4 into the sea by the command from the device 8 and the power source 3 is turned on by the signal passing through the wire 12 of the device 8, then protective current 13 flows from the electrode 4 into the material 2, thereby decreasing the elution of the copper. The optimum current value is maintained in this stage by detecting the potential of the material 2 by the electrode 9 and controlling the power source 3 by the device 8 based on said value. |
