Gas bleed arrangement

Patent metadata

Field	Value
Publication number	US-2016265442-A1
Application number	US-201615048401-A
Country	US
Kind code	A1
Filing date	Feb 19, 2016
Priority date	Mar 10, 2015
Publication date	Sep 15, 2016
Grant date	—

Abstract

A gas bleed arrangement for a gas turbine engine. The gas bleed arrangement includes an annular casing defining a main gas flow path. The annular casing has a plurality of bleed ducts each defining a respective bleed flow path. The arrangement further includes a blocking element having at least one aperture. The blocking element is moveable to align the at least one aperture at least partly between the main gas flow path and at least one of the bleed flow paths to control fluid communication between the main gas flow path and the at least one of the bleed flow paths through the aperture.

First claim

1 . A gas bleed arrangement for a gas turbine engine, said gas bleed arrangement comprising:
an annular casing defining a main gas flow path, said annular casing having a plurality of bleed ducts each defining a respective bleed flow path; a blocking element having at least one aperture, wherein the blocking element is moveable to align the at least one aperture at least partly between the main gas flow path and at least one of the bleed flow paths to control fluid communication between the main gas flow path and the at least one of the bleed flow paths through the aperture.

2 . An arrangement according to claim 1 wherein the blocking element is axially and/or rotatably or pivotably moveable.

3 . An arrangement according to claim 1 wherein each bleed duct extends from a respective radially inner bleed duct opening.

4 . An arrangement according to claim 3 wherein the radially inner bleed duct openings open into a common duct extending from a radially inner common duct opening through the annular casing from the main gas flow path to the bleed flow paths/ducts.

5 . An arrangement according to claim 3 wherein the blocking element comprises a main blocking portion dimensioned to fully block the plurality of radially inner bleed duct openings or to fully block the radially inner common duct opening.

6 . An arrangement according to claim 3 wherein, in a first, fully closed position, the main blocking portion is completely aligned with the plurality of radially inner bleed duct openings or with the radially inner common duct opening.

7 . An arrangement according to claim 6 wherein the blocking element is moveable to move the blocking element from the first, fully closed position to a second fully open position in which the plurality of bleed ducts are in fluid communication with the main gas flow path.

8 . An arrangement according to claim 7 wherein the blocking element is moveable from the first position to the second position through at least one intermediate position in which only one/some of the bleed duct(s) but not all is/are in fluid communication with the main gas flow path.

9 . An arrangement according to claim 8 wherein, in a first intermediate position, the or one of the at least one apertures is at least partly aligned with one of the radially inner bleed duct openings.

10 . An arrangement according to claim 5 wherein the blocking element is annular or a segment of an annulus and the blocking element comprises the main blocking portion and a secondary blocking portion, the main and secondary blocking portions being spaced by the at least one aperture.

11 . An arrangement according to claim 10 wherein the secondary blocking portion is dimensioned to be smaller than the cross-sectional area of the plurality of bleed ducts.

12 . An arrangement according to claim 11 wherein the secondary blocking portion is dimensioned to match the cross-sectional area of one of the plurality of bleed flow paths/radially inner openings.

13 . An arrangement according to claim 10 wherein the main blocking portion is axially and/or circumferentially spaced from the secondary blocking portion by the at least one aperture.

14 . An arrangement according to claim 1 wherein the blocking element is a scoop element having a scoop opening which is alignable with the main gas flow path, a main blocking portion extending to a curved surface opposite the scoop opening, the curved surface comprising the at least one aperture.

15 . An arrangement according to claim 14 comprising at least two apertures in the curved surface, the at least two apertures spaced from one another around the radius of the curved surface.

16 . A method for bleeding gas from a main gas flow path in a gas turbine engine, said gas bleed arrangement comprising:
providing a gas bleed arrangement according to claim 1 ; and moving the blocking element to selectively align the at least one aperture at least partly between the main gas flow path and at least one of the bleed flow paths to control fluid communication between the main gas flow path and the at least one of the bleed flow paths through the aperture.

17 . A method according to claim 16 wherein the main blocking portion is dimensioned to completely block the plurality of radially inner bleed duct openings/common duct opening and the method comprises moving the blocking element to a first, fully closed position in which the main blocking portion is completely aligned between the main gas flow path and the plurality of bleed flow paths.

18 . A method according to claim 17 comprising moving the blocking element from the first, fully closed position to a second fully open position in which the plurality of bleed ducts are in fluid communication with the main gas flow path.

19 . A method according to claim 18 comprising moving the blocking element from the first position to the second position through at least one intermediate position in which in which only one/some of the bleed duct(s) is/are in fluid communication with the main gas flow path.

20 . A gas turbine engine comprising a bleed arrangement according to claim 1 .

Assignees

• Rolls Royce Plc

Inventors

• Beecroft Peter

Classifications

• F04D29/522

  especially adapted for elastic fluid pumps · CPC title

• F04D27/009

  by bleeding, by passing or recycling fluid · CPC title

• F02C9/18 Primary

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title

• F01D17/105

  by passing part of the fluid · CPC title

• F04D27/023

  Details or means for fluid extraction · CPC title