Device for bleeding air from a turbomachine compressor
View Patent ↗A turbomachine compressor, including an air bleed device including a duct having a suction end opening out into an outer casing of the compressor level with a rotor wheel and a stator stage of the compressor is disclosed. A screen sheet of annular shape is mounted radially inside the casing facing a portion of the suction end of the duct so as to make the bleeding of air uniform over 360° around the axis of the compressor.
1. A compressor, including air bleed means comprising a duct having a suction end opening out into an outer casing of the compressor level with a rotor wheel and a stator stage arranged coaxially with the compressor,
wherein a screen sheet of annular shape is mounted radially inside the outer casing facing a portion of the suction end of the duct, and
wherein the screen sheet extends over less than 360° and includes circumferential ends each having a rim of cylindrical shape, the rims bearing radially against a flange of the outer casing and defining an annular space between them and between the screen sheet and the flange.
2. A compressor according to claim 1 , wherein the sheet has a downstream end fastened by screws to an annular flange of the stator stage mounted downstream from the rotor wheel.
3. A compressor according to claim 2 , wherein the screen sheet extends over about 234° and the cylindrical rims at the circumferential ends of the screen sheet extend angularly over several tens of degrees.
4. A compressor according to claim 2 , wherein the downstream end of the screen sheet includes holes of larger diameter disposed alternately with holes of smaller diameter for passing fastener screws.
5. A compressor according to claim 2 , wherein the screen sheet is mounted with resilient prestress to bear against the flange of the casing.
6. A compressor according to claim 2 , wherein a stator stage situated upstream from the rotor wheel is fastened to the flange of the casing by a shroud that includes holes, with those that are angularly situated level with the suction end of the duct and a central portion of the screen sheet being totally covered.
7. A compressor according to claim 6 , wherein the holes in the shroud facing axially the circumferential end portions of the screen sheet are 50% covered.
8. A compressor according to claim 1 , wherein the screen sheet includes at least one orifice for passing an endoscope.
9. A screen sheet of annular shape for use in a compressor according to claim 1 , wherein the screen sheet section is L-shaped.
10. A screen sheet according to claim 9 , comprising a cylindrical wall connected at a first end to a radial wall having holes for passing fastener screws and connected at a second end to a frustoconical wall.
11. A screen sheet according to claim 10 , wherein the circumferential ends of the frustoconical wall includes radial rims facing outwards.
12. A turbomachine including a compressor according to claim 1 .
13. A turbomachine according to claim 12 , wherein the turbomachine is an airplane turboprop or a turbojet.
14. A compressor according to claim 1 , wherein the cylindrical rims are provided on an upstream end of the screen sheet.