| 摘要 |
PROBLEM TO BE SOLVED: To provide an excavating conduit disconnecting method according to which the vertical vibration of an excavation conduit is easily and effectively reduced when a riser pipe is disconnected, and to provide an excavating conduit disconnecting apparatus and seabed excavating facilities using the same. SOLUTION: The excavating conduit disconnecting apparatus is formed of: the excavating conduit 7 of a double pipe structure having a drill pipe 3 into which muddy water MW having a specific gravity larger than that of sea water SW is supplied, and the riser pipe 6 arranged outside the drill pipe 3, and connecting between an excavating ship (floating body) floating on the sea, and an excavation port formed in the seabed; a separating device for separating the excavating conduit 7 and the excavation port from each other; a central valve 32 arranged at the longitudinal center of the drill pipe 3, for restricting flowage of fluid; and a sea water supply device for supplying the sea water SW to the drill pipe 3 at a location immediately below the central valve 32. According to the excavating conduit disconnecting method, the excavating conduit 7 is separated from the excavation port, and before and after the separation, the muddy water MW in the drill pipe 3 is replaced by the sea water SW except for the muddy water MW remaining at the longitudinal center of the drill pipe 3. COPYRIGHT: (C)2007,JPO&INPIT
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