CLEANING OF A TURBO-MACHINE STAGE

• US 20130174869A1
• Filed: 08/03/2011
• Published: 07/11/2013
• Est. Priority Date: 08/03/2010
• Status: Active Grant

• Current Assignee: MTU Aero Engines GmbH (MTU)
• Original Assignee: MTU Aero Engines GmbH (MTU)
• Inventors: Seidel, Frank, Winkler, Lutz, Kriegl, Bernd, Uihlein, Thomas, Rsing, Jrgen, Drr, Martin, Moritz, Fabian
• Granted Patent: US 9,492,906 B2
• Time in Patent Office: Days
• US Class Current: 134/7
• CPC Class Codes: B08B 7/0021 by liquid gases or supercritical fluids
• CPC Class Codes: B08B 9/00 Cleaning hollow articles by methods or apparatus specially adapted thereto B08B6/00 takes precedence
• CPC Class Codes: B24C 1/003 using material which dissolves or changes phase after the treatment, e.g. ice, CO2
• CPC Class Codes: B24C 1/086 Descaling; Removing coating films
• CPC Class Codes: B24C 3/325 for internal surfaces, e.g. of tubes
• CPC Class Codes: F01D 25/002 Cleaning of turbomachines

Abstract

The invention relates to a method for cleaning a turbo-machine stage (100) consisting of at least one of the following steps: a cleaning nozzle (1) is introduced into an opening of a turbo-machine, in particular into an inspection opening (220); and the blade (100) of the stage is acted upon by solid particles, said particles subliming at the blade temperature, in particular into dry ice particles.

Claims

1-11. -11. (canceled)

12. A method for cleaning a machine stage of a gas turbine, the method comprising the following steps:

introducing a cleaning nozzle through an opening in an outer wall of a gas turbine, the gas turbine further including a plurality of machine stages, each machine stage including

a rotor rotatable around an axis of rotation and defining a radial direction perpendicular to the axis of rotation,

a plurality of radially oriented blades arranged around the axis of rotation, each blade having a blade temperature and

at least some of the blades being mounted on the rotor so as to revolve around the axis of rotation when the machine stage rotates; and

acting on a blade of a machine stage with solid particles delivered by the cleaning nozzle, which particles sublime at the blade temperature.

13. A method in accordance with claim 12, wherein the solid particles are dry ice particles (CO_2(s)).

14. A method in accordance with claim 12, wherein the opening in the outer wall is arranged between the turbo-machine stage to be cleaned and an adjacent turbo-machine stage.

15. A method in accordance with claim 12, wherein the turbo-machine stage is rotated, either manually and/or by motor-drive, in situ during the cleaning.

16. A method in accordance with claim 15, wherein the cleaning nozzle is radially displaced, either manually and/or by motor-drive, during a rotation of the turbo-machine stage.

17. A method in accordance with claim 15, wherein the cleaning nozzle is radially displaced, either manually and/or by motor-drive, after a rotation of the turbo-machine stage.

18. A method in accordance with claim 12, wherein:

the cleaning nozzle includes a jet outlet defining a direction for delivery of the solid particles; and

the direction of the jet outlet includes a substantially constant radial and/or peripheral component.

19. A method in accordance with claim 12, wherein the blade temperature, during the cleaning, is at least 10°

C. higher than an environmental temperature.

20. A method in accordance with claim 12, wherein each cleaning nozzle delivers the solid particles acting on the blade at a mass flow within the range from 0.1 kg/min to 1.0 kg/min.

21. A method in accordance with claim 20, wherein each cleaning nozzle delivers the solid particles acting on the blade at a mass flow within the range from 0.6 kg/min to 0.7 kg/min.

22. A method in accordance with claim 12, wherein a plurality of cleaning nozzles are introduced through openings in the outer wall of the gas turbine simultaneously and:

a plurality of blades in a single machine stage are acted upon simultaneously; and

/or

at least one blade in each of a plurality of machine stages are acted upon simultaneously.

23. A method in accordance with claim 12, wherein the cleaning nozzle further comprises at least one of:

a radially front portion produced from a material that is softer than the material of the turbo-machine stage; and

/or

a stick-slip coating that comprises at least one of MoSi2 and PTFE; and

/or

an annular contact protection member.

24. A method in accordance with claim 12, wherein the cleaning nozzle further comprises:

a guide pipe; and

an inner pipe having a nozzle opening, the inner pipe being shiftably arranged at least partially within the guide pipe.

25. A method in accordance with claim 24, wherein the cleaning nozzle further comprises a handle for thermal insulation.