Groundwater drawdown methods and groundwater drawdown equipment

摘要

PROBLEM TO BE SOLVED: To provide pumping equipment and an underground water level lowering device, which can be applied to existing equipment without a modification to it, and offer efficiency and high convenience.;SOLUTION: The pumping equipment is equipped with a vacuum pump 11, a collecting vessel 7, a lifting pump 6 and a drain pipe 4 which is connected the lifting pump 6; an upper end of the collecting 7 is shielded; a lower end of the collecting vessel 7 is opened; air can be discharged from an internal space, which is surrounded by a side wall of the collecting vessel 7, by means of the vacuum pump 11; the lifting pump 6 is constituted by being housed in the collecting vessel 7; and a collecting pipe 7 can be used by being moved upward and downward in a well with the lifting pump 6. In addition, a gap (a) can be provided between the collecting vessel 7 and internal walls of well bypasses (1, 2 and 3), so that the air and water can be separated in the gap (a).;COPYRIGHT: (C)2003,JPO