Assembly for a gas turbine engine
An assembly for removing entrained particles from a fluid stream passing through a gas turbine engine includes a first particle remover, a second particle remover fluidly coupled which receives a particle-laden stream from the first particle remover, and a venturi having a fluidly coupled to the second particle remover to increase the pressure differential across the assembly.
1. An assembly for removing entrained particles from a fluid stream passing through a gas turbine engine, comprising:
a first particle remover having a particle separator separating the fluid stream into a first reduced-particle stream and a particle-laden stream, and comprising a main flow outlet emitting the first reduced-particle stream and a scavenge flow outlet emitting the particle-laden stream; and
a second particle remover fluidly coupled to the scavenge flow outlet and comprising a return outlet emitting a second reduced-particle stream; and
a venturi formed by a junction of the main flow outlet and the return outlet, where the main flow outlet at the junction has a reduced cross section defining a low pressure area, and the return outlet is fluidly coupled to the low pressure area at the junction, whereby the second reduced-particle stream is drawn by the low pressure area into and mixed with the first reduced particle stream at the junction.
2. The assembly of claim 1 wherein the venturi comprises a constricted section of a conduit downstream of the return outlet.
3. The assembly of claim 1 wherein the second particle remover comprises a filter.
4. The assembly of claim 3 wherein the filter is configured to capture particles greater than 0.01 microns in size.
5. The assembly of claim 3 wherein the filter comprises a filter media of porous ceramic, porous metal, metal foam, metal fiber, ceramic fiber, metal honeycomb, or ceramic honeycomb.
6. The assembly of claim 1 wherein the first particle remover comprises a centrifugal separator.
7. The assembly of claim 6 wherein the second particle remover comprises an inertial separator.
8. The assembly of claim 7 wherein the inertial separator comprises a swirler located within the fluid stream and imparting a tangential velocity to the fluid stream, thereby providing the fluid stream with a swirling motion downstream of the swirler.
9. The assembly of claim 8 wherein the inertial separator comprises a deswirler located downstream of the swirler and removing the tangential velocity from the fluid stream.
10. The assembly of claim 9 wherein the swirler comprises one of a plurality of swirl vanes, and the deswirler comprises one of a plurality of deswirl vanes.
11. The assembly of claim 7 wherein the inertial separator comprises a body having a peripheral wall defining a flow passage through which the fluid stream flows.
12. The assembly of claim 11 wherein the inertial separator further comprises a scavenge annulus within the peripheral wall and defining the main flow outlet.
13. The assembly of claim 1 wherein the second particle remover is coupled with the first particle remover via at least one conduit.
14. The assembly of claim 13 wherein the at least one conduit comprises a first conduit extending from the scavenge outlet to the second particle remover and a second conduit extending from the return outlet to the venturi.
15. The assembly of claim 14 wherein the second conduit is fluidly coupled with the venturi to provide the second reduced-particle stream at an angle of 45 degrees or less with respect to the first reduced-particle stream.
16. The assembly of claim 1 , wherein the venturi further comprises a low pressure outlet downstream of the main flow outlet.
17. The assembly of claim 1 , wherein the venturi further comprises a low pressure outlet upstream of the main flow outlet.