IMAGING SYSTEM FOR ROBOTICALLY INSPECTING GAS TURBINE COMBUSTION COMPONENTS

• US 20050073673A1
• Filed: 10/01/2003
• Published: 04/07/2005
• Est. Priority Date: 10/01/2003
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Devitt, John William, Ferreira, Custodio J.S.
• Granted Patent: US 7,271,894 B2
• Time in Patent Office: Days
• US Class Current: 356/37
• CPC Class Codes: F01D 21/003 Arrangements for testing or measuring for measuring vibrations G01H
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: G01N 21/6447 by visual observation
• CPC Class Codes: G01N 21/8803 Visual inspection measuring projectors G01B9/08
• CPC Class Codes: G01N 21/954 Inspecting the inner surface of hollow bodies, e.g. bores
• CPC Class Codes: G01N 2203/0647 Image analysis
• CPC Class Codes: G01N 3/567 by submitting the specimen to the action of a fluid or of a fluidised material, e.g. cavitation, jet abrasion G01N3/565 takes precedence
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A system for in situ inspection of a surface of a hot gas component of a turbine includes a robot having an elongated inspection arm extending toward the surface of the hot gas component; and an inspection head carried adjacent an end of the inspection arm remote from controls for the robot. The inspection head is manipulated by the inspection arm to locate the inspection head adjacent interior wall portions defining the hot gas component including by displacing the inspection head in a generally axial direction and generally radially toward a wall portion of the hot gas component being inspected. The inspection head is configured with a UV system to excite and detect fluorescence from a taggant material disposed in a coating on the hot gas component.

Claims

1. A system for in situ inspection of a surface of a hot gas component of a turbine comprising:

a robot having an elongated inspection arm extending toward the surface of the hot gas component; and

an inspection head carried adjacent an end of said inspection arm remote from controls for said robot, said inspection head manipulated by said inspection arm to locate said inspection head adjacent interior wall portions defining the hot gas component including by displacing the inspection head in a generally axial direction and generally radially toward a wall portion of the hot gas component being inspected;

wherein said inspection head is configured with a UV system to excite and detect fluorescence from a taggant material disposed in a coating on the hot gas component.

2. The system of claim 1, wherein said UV system is configured for simultaneous usage with a visual inspection system on said inspection head.

3. The system of claim 1, wherein said UV system includes a UV light source configured to excite said taggant material with a wavelength between about 254 nm and about 300 nm.

4. The system of claim 1, wherein said UV system includes an intensified camera configured to detect fluorescence from said taggant material.

5. The system of claim 4, wherein said intensified camera is fiber optically coupled to a collection lens.

6. The system of claim 2, wherein each UV system and visual inspection system camera includes a suitable filter to filter out light generated from a light source for use with the other system camera.

7. The system of claim 6, wherein said suitable filter for a camera of said UV system includes a 610 nm optical filter with about a 10 nm bandwidth operably coupled to an objective lens of the camera configured to protect the camera from stray environmental light.

8. The system of claim 3, wherein a corresponding 254 nm to about 300 nm band pass filter is operably coupled to said UV source.

9. The system of claim 4, wherein said intensified camera is a black and white (CCD) digital camera with a built-in intensifier tube.

10. The system of claim 4, wherein said intensified camera includes an objective lens with an auto iris for protection from intense focused light.

11. The system of claim 4, wherein said intensified camera is operably connected to said inspection arm along an axis defining said inspection arm and is axially aligned therewith such that a mirror is oriented generally at a 45 degree angle for viewing an object normal to a field of view of said intensified camera.

12. The system of claim 1, wherein said UV system is configured to detect at least one of defects as small as 12.5 mm in diameter and defects in said coating with less than about 1% of said taggant material.

13. The system of claim 1, wherein said coating is a thermal barrier coating (TBC).

14. The system of claim 1, wherein said inspection head is configured to rotate about pan and tilt axes relative to said arm.

15. A system for in situ inspection of a turbine having a transition piece body forming part of each of a plurality of an annular array of combustors for a gas turbine, each combustor having a combustion casing forwardly of the transition piece body thereof comprising:

a mount secured to an interior robotic manipulator and to an open end of one of said combustion casings forwardly of the transition piece body thereof;

an elongated inspection arm extending from said mount toward the one transition piece body of the one combustion casing; and

an inspection head carried adjacent an end of said inspection arm remote from said mount within the one transition piece body of the one combustion casing, said inspection head manipulated by said inspection arm to locate said inspection head adjacent interior wall portions of the said transition piece body including by displacing the inspection head in a generally axial direction and generally radially toward a wall portion of the transition piece body being inspected;

wherein said inspection head is configured with a UV system to excite and detect fluorescence from a taggant material buried in a thermal barrier coating (TBC) on the transition piece body.

16. The system of claim 15, wherein said UV system is configured for simultaneous usage with a visual inspection system on said inspection head.

17. The system of claim 15, wherein said UV system includes a UV light source configured to excite said taggant material with a wavelength between about 254 nm and about 300 nm.

18. The system of claim 15, wherein said UV system includes an intensified camera configured to detect fluorescence from said taggant material.

19. The system of claim 18, wherein said intensified camera is fiber optically coupled to a collection lens.

20. The system of claim 18, wherein said intensified camera is a black and white (CCD) digital camera with a built-in intensifier tube.

21. The system of claim 18, wherein said intensified camera includes an objective lens with an auto iris for protection from intense focused light.

22. The system of claim 15, wherein said UV system is configured to detect at least one of defects as small as 12.5 mm in diameter and defects in said coating with less than about 1% of said taggant material.