Dirt particle separator device for use in a gas turbine engine
A separator device is provided for separating dirt particles from a flow of cooling air fed to airfoils of the turbine section of a gas turbine engine. In use the separator device extends across a conduit which bypasses the combustor of the engine to convey pressurized cooling air carrying dirt particles from the compressor section of the engine to openings which direct the air into the airfoils. The separator device is configured to direct a first portion of the impinging cooling air flow away from the openings and to allow a second portion of the impinging cooling air to continue to the openings. The first portion of cooling air has a higher concentration of the coarsest dirt particles carried by the cooling air than the second portion of cooling air.
1. A separator device that separates dirt particles from a flow of cooling air fed to airfoils of the turbine section of a gas turbine engine comprising:
an array of scoops that direct a first portion of impinging cooling air flow away from openings which direct the air into the airfoils and to allow a second portion of the impinging cooling air to continue to the openings; and
an impingement surface provided on the array of scoops, wherein the separator device has a plurality of through-holes formed on the impingement surface through which the second portion of the cooling air passes to continue to the openings,
wherein the separator device is located in a conduit which is radially outwards of a working gas annulus,
wherein the separator device extends, in use, across the conduit which bypasses a combustor of the engine to convey pressurized cooling air carrying dirt particles from a compressor section of the engine to the openings, and
wherein the first portion of cooling air has a higher concentration of the coarsest dirt particles carried by the cooling air than the second portion of cooling air.
2. The separator device according to claim 1 , wherein each scoop comprises ridges and a trough.
3. The separator device according to claim 1 , wherein the conduit forms an annulus and the separator device is correspondingly ring-shaped to extend across the conduit and may be either annular or an annular array of circumferential segments.
4. The separator device according to claim 1 , wherein the through-holes are sized to prevent or restrict the passage therethrough of the coarsest dirt particles.
5. The separator device according to claim 1 , wherein the through-holes are formed as slots.
6. The separator device according to claim 5 , wherein the slots extend substantially in a radial direction of the engine.
7. The separator device according to claim 1 , wherein the impingement surface is shaped to direct the first portion of the cooling air flow away from the openings.
8. The separator device according to claim 7 , wherein the impingement surface forms a series of generally radially extending, circumferentially spaced, ridges.
9. The separator device according to claim 2 , wherein the height of each ridge increases towards the radial center of the conduit.
10. The separator device according to claim 8 , wherein the through-holes are located on the tops of the ridges.
11. The separator device according to claim 1 , which directs the first portion of the cooling air towards discharge nozzles which feed the first portion of the cooling air into a working gas annulus upstream of the airfoils.
12. The separator device according to claim 1 , which is formed from a plurality of separator sub-portions, each sub-portion occupying a respective sector of the conduit.
13. The separator device according to claim 1 , wherein the separator device is located in a conduit which is radially outwards of a working gas annulus of the gas turbine engine with respect to the central axis of the gas turbine engine.
14. A gas turbine engine comprising the separator device according to claim 1 .