| 摘要 |
PURPOSE:To prevent an insulating oil in an oil tank from decreasing its quantity below a certain quantity in case of occurrence of oil leakage in a clean oil pipe line of the insulating oil by providing an oil level lowering prevention device to a part of a drainage pipe of the oil tank. CONSTITUTION:When a leakage is generated in a clean oil pipe line such as feed and drainage pipes 5 and 6 and a hot-line oil cleaner 7, an oil level in an oil tank 3 begins to lower by a siphon method. When this oil level lowering reaches a drainage pipe 6a provided with an oil level lowering prevention device 12 of an A frame portion, the air introduced into the oil tank 3 through a conservator pipe 9 is introduced into the drainage pipe 6a through a cylinder 13 and a vent hole 21 from a vent hole 20 of the oil level lowering prevention device 12. As a suction power of the air by the drainage pipe 6 is smaller than that of an insulating oil 2 from a bottom of the oil tank 3, the suction of the insulating oil 2 from a bottom of the oil tank 3 by the drainage pipe 6 is prevented, and lowering below a certain quantity of the insulating oil 2 in the oil tank 3, that is to say, lowering below a part of the drainage pipe 6a of the A frame portion provided with the oil level lowering prevention device 12 is prevented. |
