Patent ID: 6053261
Filing Date: 2000-04-25
Classification: E21B

Abstract:
Apparatus for effecting pulsations in a flow of liquid comprising:an elongated hollow housing defining a primary flow passage adapted to carry a flow of liquid axially therealong;an elongated conduit having an upstream end and a downstream end extending within said housing and defining a main flow passage interiorly of said conduit which communicates at its downstream end with said primary flow passage, and a by-pass flow passage extending lengthwise of said conduit from said upstream end to said downstream end thereof;a nozzle located in said hollow housing adjacent to and spaced from the upstream end of said conduit and adapted to discharge flow passing along said primary passage into said main flow passage defined by said conduit; the space between said nozzle and said upstream end providing communication between said main flow passage and said by-pass flow passage;an axially movable valve member located in the downstream end of said conduit and co-operating with a valve seat located downstream of said valve member for interrupting the flow through said conduit; there being one or more further passages downstream of said valve seat providing communication between said main flow passage and said by-pass passage in a region downstream of said valve seat;a spring for urging said valve member toward an open position in the upstream direction; said valve member being adapted to move to a closed position in response to flow along said valve member thus interrupting the flow through said conduit and creating a water hammer pulse which travels upstream through said conduit and said nozzle and also through said space between said nozzle and the upstream end of said conduit whereupon said pulse also travels downstream along said by-pass passage and through said further passage(s) to said region downstream of said valve member thus tending to momentarily equalize water hammer pressures on upstream and downstream sides of said valve member with said spring being adapted to move said valve member away from said seat under these equalized pressures whereupon flow within said conduit again commences thus again effecting the closure of said valve member whereupon the above recited sequence of events is repeated to produce a cyclical water hammer and flow pulsating effect.