Method and device for cleaning a jet engine

Patent metadata

Field	Value
Publication number	US-2016298488-A1
Application number	US-201415100344-A
Country	US
Kind code	A1
Filing date	Nov 28, 2014
Priority date	Nov 29, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

A method for cleaning a jet engine includes introducing into the engine, via a carrier gas by way of at least one nozzle, a cleaning medium which contains solids. The pressure of the carrier gas is 1 to 5 bar. An exit of the at least one nozzle is disposed at a radial spacing from a rotation axis of the engine which corresponds to 0.6 to 1.2 times the radius of the entry opening of a first compressor stage that is directed upstream. A main exit direction of the nozzle in relation to the rotation axis of the engine encloses an angle of 10 to 30°.

First claim

1 . A method for cleaning a jet engine, the method comprising:
introducing into the engine, via a carrier gas by way of at least one nozzle, a cleaning medium which contains solids, wherein the pressure of the carrier gas is 1 to 5 bar; wherein an exit of the at least one nozzle is disposed at a radial spacing from a rotation axis of the engine which corresponds to 0.6 to 1.2 times the radius of the entry opening of a first compressor stage that is directed upstream, and wherein a main exit direction of the at least one nozzle in relation to the rotation axis of the engine encloses an angle of 10 to 30°.

2 . The method of claim 1 , wherein the exit of the at least one nozzle is disposed at a radial spacing from the rotation axis of the engine which corresponds to 0.6 to 1 times the radius of the entry opening of the first compressor stage that is directed upstream.

3 . The method of claim 1 , wherein the main exit direction of the at least one nozzle in relation to the rotation axis of the engine encloses an angle which is between β and α;
wherein β is the angle between the rotation axis of the engine and a first straight line which runs as a tangent on that convex curvature of the flow duct of the compressor that in the flow direction is at the front and is disposed so as to be radially inward, and on that convex curvature of the flow duct that in the flow direction is disposed behind the former and so as to be radially outward;
wherein α is the angle between the rotation axis of the engine and a second straight line which runs as a tangent on that periphery of the inlet of the compressor that is disposed so as to be radially outward, and on that convex curvature of the flow duct that in the flow direction is disposed behind the former and so as to be radially inward; and
wherein the exit of the at least one nozzle is disposed at a radial spacing from the rotation axis of the engine which lies between the radial spacings of the intersection points of the first and the second straight line with that radial plane in which the exit is disposed.

4 . The method of claim 1 , wherein the solids are selected from the group composed of solid carbon dioxide and water ice.

5 . The method of claim 4 , wherein the carbon dioxide and/or the water ice is present and used so as to be comminuted in the form of pellets or in another form.

6 . The method of claim 4 , wherein the cleaning medium has solid carbon dioxide and water ice in a ratio by mass of 5:1 to 1:5.

7 . The method of claim 4 , wherein the solid carbon dioxide and/or the water ice have/has a pellet size of 1 to 10 mm.

8 . The method of claim 1 , characterized in that the solids are introduced at a mass flow rate of 100 to 2000 kg/h.

9 . The method of claim 1 , wherein cleaning of the jet engine is carried out over a duration of 1 to 15 min.

10 . The method of claim 1 , wherein during one cleaning procedure 1.5 to 200 kg of solids are introduced into the engine.

11 . The method of claim 1 , wherein the at least one nozzle is a flat-jet nozzle.

12 . The method of claim 1 , wherein the jet engine is allowed to rotate at a fan revolution speed of 50 to 500 min −1 .

13 . (canceled)

14 . A nozzle installation comprising:
at least one nozzle configured for introducing cleaning media containing solids into a jet engine, and for a rotationally fixed connection to a shaft of a turbofan of a jet engine, and wherein the at least one nozzle has a swivel coupling to which a line connection is connectable, wherein a flexible hose forms a connection of a nozzle-side outlet of the swivel coupling to an inlet of the at least one nozzle.

15 . The nozzle installation of claim 14 , wherein the nozzle-side outlet of the swivel coupling is diametrically opposite the inlet.

16 . The nozzle installation of claim 14 , wherein the swivel coupling is spaced apart from the means for the rotationally fixed connection to the shaft of the turbofan of a jet engine by 0.2 to 2 m.

17 . The nozzle installation of claim 14 , wherein guiding of the cleaning medium from the inlet of the at least one nozzle to the nozzle exit is configured so as to be substantially in a straight line.

18 . The nozzle installation of claim 14 , wherein the nozzle installation is configured for introducing the cleaning medium into the compressor stages of the jet engine.

19 . The nozzle installation of claim 14 , wherein the nozzle installation has at least one nozzle.

20 . The nozzle installation of claim 14 , wherein the nozzle installation has flat-jet nozzles.

21 . The nozzle installation of claim 14 , wherein the radial spacing of the nozzle exit from the rotation axis of the engine is 200 to 800 mm.

22 . The nozzle installation of claim 14 , wherein the plane of the jet in relation to the rotation axis of the jet engine encloses an angle which is preferably 10 to 30°.

23 . The nozzle installation of claim 14 , wherein the plane of the jet in relation to the rotation axis of the jet engine encloses an angle which is between β and α;
wherein β is the angle between the rotation axis of the engine and a first straight line which runs as a tangent on that convex curvature of the flow duct of the compressor that in the flow direction is at the front and is disposed so as to be radially inward, and on that convex curvature of the flow duct that in the flow direction is disposed behind the former and so as to be radially outward;
wherein α is the angle between the rotation axis of the engine and a second straight line which runs as a tangent on that periphery of the inlet of the compressor that is disposed so as to be radially outward, and on that convex curvature of the flow duct that in the flow direction is disposed behind the former and so as to be radially inward.

24 . An assembly comprising:
a jet engine; and the nozzle installation of claim 14 , wherein the nozzle installation is disposed such that the at least one nozzle thereof is directed toward an inlet of the jet engine such that the cleaning medium can make its way into the jet engine.

25 . The assembly of claim 24 , wherein a main exit direction of the at least one nozzle in relation to the rotation axis of the jet engine encloses an angle of 10 to 30°.

26 . The assembly of claim 24 , wherein the exit of the at least one nozzle is disposed at a radial spacing from the rotation axis of the engine which corresponds to 0.5 to 1.2 times the radius of the entry opening of the first compressor stage that is directed upstream.

27 . The assembly of claim 24 , wherein the main exit direction of the at least one nozzle in relation to the rotation axis of the jet engine encloses an angle which is between β and α;
wherein β is the angle between the rotation axis of the engine and a first straight line which runs as a tangent on that convex curvature of the flow duct of the compressor that in the flow direction is at the front and is disposed so as to be radially inward, and on that convex curvature of the flow duct that in the flow direction is disposed behind the former and so as to be radially outward;
wherein α is the angle between the rotation axis of the engine and a second straight line which runs as a tangent on that periphery of the inlet of the compressor that is disposed so as to be radially outward, and on that convex curvature of the flow duct that in the flow direction is d

Assignees

• Lufthansa Technik Ag

Inventors

• Appel Holger
• Braeutigam Klaus

Classifications

• F01D25/002 Primary

  Cleaning of turbomachines · CPC title

• F04D29/701

  especially adapted for elastic fluid pumps · CPC title

• B24C1/003

  using material which dissolves or changes phase after the treatment, e.g. ice, CO2 · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• B24C5/04

  Nozzles therefor (nozzles in general B05B) · CPC title