Patent ID: 7036577
Filing Date: 2006-05-02
Classification: E02D,E21B

Abstract:
1. A groundwater pumping apparatus comprising: an outer tube buried in ground, which has a water-passing portion at its lower part; an inner tube having a substantially same length as said outer tube and placed in said outer tube such that said inner tube is spaced from said outer tube, said inner tube having a groundwater inlet at its bottom end, which is provided at a position lower than a top end of said water-passing portion; a shield member configured to shield top ends of said outer tube and said inner tube; a vacuum unit configured to reduce a pressure in said inner tube; a pump unit configured to pump groundwater that comes in said inner tube through said groundwater inlet; a pressure unit configured to increase the pressure in said inner tube; and a water injection unit configured to carry out a pressure injection of water in said inner tube.