GB944179A - Improvements relating to land drainage - Google Patents

Abstract

944,179. Forcing liquids by gaseous pressure. SOIL MECHANICS Ltd. Nov. 20, 1961 [Nov. 21, 1960], No. 39971/60. Heading FIR. In apparatus for raising water from a bore hole by compressed air and comprising a perforated pipe 4, 6 with a sump 1 at its bottom end and enclosing a riser pipe 8, means are provided at the bottom of the annular space between the perforated pipe and riser pipe for obstructing flow of fluid between the sump and the annular space when the sump is full of water. In the embodiment shown, said means comprise an annular float valve 19 which seats against a sleeve 18. Electrical contacts may be provided whereby, when valve 19 closes, a source of compressed air is connected to a pipe 22 and when the sump is empty a source of vacuum is connected thereto. In other embodiments said means comprise constricted rubber tubes depending into the sump, and vertical flap valves controlling communication between the pipe 4 and the sump. In another embodiment a Venturi formed in the riser pipe communicates at its throat with the annular space through ports such that upward flow in the riser pipe causes suction at the ports. The riser pipe 8 is removable and has a tapered end 14 to facilitate re-location. A non-return valve 11 is provided in the riser pipe.