Patent ID: 7267328

Claim:
An airlift pump suitable for transporting large volumes of water to a water surface at low pumping head comprising: at least three vertically-mounted, concentric opened-ended pipe sections, having diameters increasing from lower sections to upper sections with expanding tapers of less than two degrees, with a top end of each lower section positioned in close proximity to a bottom end of an upper section and positioned such that airlift induced water is able to flow upwardly through a resulting gap between the walls of each such section, and having the bottom of each pipe section flared and the flare on the uppermost pipe extending up to 2 meters radially and predominantly horizontally, and an air input positioned at the bottom of the lowest pipe section; whereby, in operation, the top of the uppermost section is not above the surface and water rises from the bottom sections to the top section and flows radially at the water surface from the top section.