Patent ID: 7150149

Claim:
An apparatus for extracting power from a fluid flow, the apparatus comprising: a fluid driveable engine; a fluid directing arrangement formed to define a channel in the flow of a primary fluid, the channel having a flow accelerating constriction shaped such that the primary fluid accelerates as it passes through the flow accelerating constriction, the fluid directing arrangement being formed to impart a rotational flow component to the primary fluid entering the flow accelerating constriction thereby creating a radial pressure gradient in the primary fluid as it passes through the flow accelerating constriction; a conduit for directing flow of a driving fluid, the driving fluid and the primary fluid being different fluids, the conduit being in fluid communication with the fluid driveable engine and a portion of the channel having accelerated fluid flow; in which the flow of driving fluid through the conduit via the rotational flow of the primary fluid in the flow accelerating constriction acts to drive the fluid driveable engine and the driving fluid is delivered to the fluid directing arrangement in response to suction pressure developed by the flow accelerating constriction such that the driving fluid is drawn substantially along the central axis of the rotational flow; whereby the fluid directing arrangement comprises at least one fluid deflector upstream of the flow accelerating constriction, the at least one fluid deflector being operable to impart angular momentum to the primary fluid.