MUDDY WATER SUCKING DEVICE FOR USE IN UNDERGROUND CONSTRUCTION WORK

PROBLEM TO BE SOLVED: To feed muddy water in a shaft of great depth onto the ground with discharge capability that is several times those of conventional devices by allowing a pump to exhibit its own ability to a maximum by eliminating the influence of atmospheric pressure above the ground. SOLUTION: A vacuum tank 9 provided on the ground is connected to a vacuum pump 11 and connected via a pipe 10 to a vacuum tank 6 installed in a shaft to decompress the vacuum tank 6 in the shaft to negative pressure to suck muddy water D from the in-shaft vacuum tank 6 via a pipe 7 connected to the inside of an adit 2. The above-ground vacuum tank 9 is connected via a pipe 13 to a pump 5 incorporated in the in-shaft vacuum tank 6 to feed the muddy water D in the in-shaft vacuum tank 6 into the above-ground vacuum tank 9 while reducing the influence of atmospheric pressure on the pipe 13 and to feed the muddy water D in the above-ground vacuum tank 9 from the pipe 13 connected via a check valve 13a to the pump 8 incorporated in the above-ground vacuum tank 9.