Gas turbine airfoil internal air system

• US 6,318,963 B1
• Filed: 05/30/2000
• Issued: 11/20/2001
• Est. Priority Date: 06/09/1999
• Status: Expired due to Term

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Self, Kevin P, Emery, Martin A J
• Primary Examiner(s): Kwon, John
• Application Number:
  US09/580,595
• Time in Patent Office: 539 Days
• Field of Search: 416/96.A, 416/97.R
• US Class Current: 416/96.00A
• CPC Class Codes: F01D 25/007 Preventing corrosion
• CPC Class Codes: F01D 25/32 Collecting of condensation water; Drainage ; Removing solid particles
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/189 the insert having a tubular cross-section, e.g. airfoil shape
• CPC Class Codes: F02C 7/30 Preventing corrosion or unwanted deposits in gas-swept spaces
• CPC Class Codes: F05D 2260/202 by film cooling
• CPC Class Codes: F05D 2260/607 Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles

Abstract

A hollow airfoil (8) has an internal air system in which a cooling gap (44) adjacent the internal surface (52) is formed by a liner insert (14) consisting of a shaped panel (14a). At least some of the cooling air circulating through the gap (44) enters through a screening arrangement, comprising exclusion apertures (50), which removes particulates over a predetermined size (e). The air is fed into a plenum chamber (46) which may be formed by a pressing in the insert panel (14a). There are two exits from the plenum (46): a first is through the screening arrangement to admit filtered air to the wall cooling gap (44), and a second is via apertures (54) in the airfoil wall (18) the sizes (d) of which apertures are large enough to pass the screened particulates into the gas path.

Claims

1. A gas turbine airfoil having an internal air system provided with a wall cooling arrangement comprises means for screening solid particulates over a predetermined size in the air flow of the internal air system, a plenum for isolating said oversize particulates, and discharge means leading from said plenum into an external airflow to discharge the oversize particles, wherein the plenum comprises a chamber adjacent a side wall of the airfoil and the wall cooling arrangement is formed by means of an insert spaced from the interior of the airfoil side wall by a predetermined gap to form the plenum chamber and a gap of narrow width through which the wall cooling arrangement is supplied with cooling air from the plenum chamber.

2. A gas turbine airfoil as claimed in claim 1 wherein the means for screening solid particulates is disposed between the plenum chamber and the wall cooling arrangement to screen particulates carried by the cooling air fed therebetween.

3. A gas turbine airfoil as claimed in claim 1 wherein the plenum chamber is formed by a concavity formed in the insert.

4. A gas turbine airfoil as claimed in claim 3 wherein the insert comprises a sheet metal panel and the concavity forming the plenum chamber is pressed into a wall of the panel.

5. A gas turbine airfoil as claimed in claim 1 wherein the discharge means comprises at least one open aperture communicating between the plenum and the external airflow.

6. A gas turbine airfoil as claimed in claim 5 wherein cooling air enters the plenum through at least one inlet aperture in a wall of the plenum which receives air from the internal air system.

7. A gas turbine airfoil as claimed in claim 6 wherein the at least one inlet aperture and the at least one discharge aperture are substantially co-axial.