Method and device for cleaning a jet engine

Patent metadata

Field	Value
Publication number	US-9903223-B2
Application number	US-201415100344-A
Country	US
Kind code	B2
Filing date	Nov 28, 2014
Priority date	Nov 29, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

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

What is claimed is:

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;
wherein a main exit direction of the at least one nozzle is obliquely inward towards the axis of rotation of the engine and in relation to the rotation axis of the engine encloses an angle of 10 to 30°;
wherein a compressor of the engine includes a flow duct having a first convex curvature at a radially-inward side of the flow duct and a second convex curvature at a radially-outward side of the flow duct, the first convex curvature being disposed in front of the second convex curvature in a flow direction of the flow duct;
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 the first and the second convex curvatures;
wherein α is the angle between the rotation axis of the engine and a second straight line which runs as a tangent on a periphery of an inlet of the compressor at the radially-outward side of the flow duct, and on the first convex curvature which is disposed behind the inlet in the flow direction of the flow duct; 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 radial spacings of intersection points of the first and the second straight lines with a radial plane at which the exit of the at least one nozzle is disposed.

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 solids are selected from the group composed of solid carbon dioxide and water ice.

4. The method of claim 3 , 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.

5. The method of claim 3 , wherein the cleaning medium has solid carbon dioxide and water ice in a ratio by mass of 5:1 to 1:5.

6. The method of claim 3 , wherein the solid carbon dioxide and/or the water ice have/has a pellet size of 1 to 10 mm.

7. The method of claim 1 , wherein the solids are introduced at a mass flow rate of 100 to 2000 kg/h.

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

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

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

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

12. 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 of 12 to 25°.

Assignees

• Lufthansa Technik Ag

Inventors

• Appel Holger
• Braeutigam Klaus

Classifications

• 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

• F04D29/701

  especially adapted for elastic fluid pumps · CPC title

• B08B5/02

  Cleaning by the force of jets, e.g. blowing-out cavities {(airguns or nozzles per se B05B1/005)} · CPC title