Partial admission axial impulse turbine including cover for turbine wheel rotating assembly
AssigneeAlliedSignal Inc.
InventorLowell W. Pearson
Life of this patent
Estimating the term…
Abstract
A cover is affixed to a turbine housing on the downstream side of a turbine wheel rotating assembly to reduce a pumping loss inherently caused by a pressure gradient created by the turbine wheel blades when the turbine wheel rotates. A portion of an annular area on the exit face of the turbine wheel is left open for gas flow out of the blades being fed by the turbine nozzle or nozzles, with the remaining annular portion being covered with a close axial clearance with the turbine wheel rotating assembly to reduce the pumping loss.
Claims14
An axial impulse partial admission turbine, comprising:
- a plurality of nozzles configured in an array forming a partial arc, each of said nozzles comprising an opening for allowing gas to flow therethrough;
- a rotating turbine wheel having an inlet face opposite said are shaped nozzle array and an exit face on the side opposite the inlet face;
- a turbine wheel housing enclosing a portion of the rotating turbine wheel and providing an exit plenum adjacent the exit face of the turbine wheel;
- and
- a turbine pressure gradient control cover positioned in said exit plenum and affixed to the turbine wheel housing, opposite the turbine wheel exit face covering a portion of the turbine exit face not axially aligned with the arc shaped nozzle array, wherein gas flowing through said nozzle array flows axially through the turbine, and the cover reduces peripheral gas flow past the exit face of the turbine wheel to thereby reduce the turbine pressure gradient loss and increase turbine efficiency.
An axial impulse turbine, comprising:
- at least one nozzle having an opening for guiding a flow of gas;
- a rotating turbine wheel having an inlet face proximate the nozzle and an exit face on a side opposite the nozzle;
- a turbine wheel housing enclosing the rotating turbine wheel and forming an exit plenum with said exit face;
- and
- a cover affixed the turbine wheel housing, opposite the turbine wheel exit face and covering more than half the exit face but not those portions axially aligned with the nozzle opening, wherein gas flows axially, not peripherally, past the turbine wheel, and the cover increases efficiency of the turbine wheel by reducing a pressure gradient to avoid loss in turbine power that can reduce efficiency.
A method for reducing the exit plenum pressure gradient created by a rotating turbine wheel of an axial impulse partial admission turbine, whereby a loss in turbine power and efficiency is reduced, comprising the steps of:
- providing a rotating turbine having an exit plenum,
- providing gas to the turbine wheel through an arc shaped array of nozzle openings;
- rotating the turbine wheel by guiding the gas axially through said turbine wheel, and
- covering a substantial portion of the turbine exit face with a cover to thereby reduce a gas pressure gradient in the exit plenum.
Dependencies are inferred from the claim text.