| 摘要 |
PURPOSE:To prevent an outflow of the liquid load through a crack by operating an automatic control device to open a switch valve automatically, and reducing the gaseous area contacting the free surface of the liquid load in a liquid load hold, when a crack is generated at the bottom of a vessel as the bottom of the hold of the liquid load. CONSTITUTION:Inside a hold A, a microphone to measure the sound when the vessel body contacts a sunken rock or the like, and a crack sensor 16 made by using a pressure gauge to measure the pressure variation transmitted in the liquid load and the like, are provided. And when the vessel body generates a crack at the bottom 2 by contacting a sunken rock or the like, an automatic control device 15 is operated by the detecting signal from the crack sensor 16 to control to open a switch valve 14 automatically, and the gaseous area 6 contacting the free surface 4 of the liquid load in the liquid load hold A is communicated to a vacuum tank 12 instantly through a gas communicating pipe 13, so as to reduce the pressure therein. In other words, the gas such as an inert gas and a crude oil vapor is absorbed to the vacuum tank 12 through the gas communicating pipe 13 to reduce the pressure of the gaseous area 6 suddenly. Consequently, the outflow of the liquid load through the crack can be prevented. |
