Method and device for cleaning a jet engine

Patent metadata

Field	Value
Publication number	US-11215071-B2
Application number	US-201615577782-A
Country	US
Kind code	B2
Filing date	May 26, 2016
Priority date	May 29, 2015
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A method for cleaning a jet engine includes introducing a cleaning medium having solid materials into the engine by way of at least one discharging device, wherein the cleaning medium exits from the discharging device at an exit speed of 80 m/s or less.

First claim

The invention claimed is:

1. A method for cleaning a jet engine, the method comprising:
introducing a cleaning medium having solid materials into the engine by way of at least one discharging device, wherein the cleaning medium exits from the discharging device at an exit speed of from 5 to 50 m/s
wherein the cleaning medium is introduced into the jet engine via a cleaning apparatus comprising the at least one discharging device in addition to a fan, a nozzle, a storage chamber a mixing chamber, and a diffuser
wherein the method further comprises:
flowing a gas into the mixing chamber via the fan;
releasing solid materials from the storage chamber into the mixing chamber such that the gas entrains the released solid materials to form the cleaning medium;
flowing the cleaning medium from the mixing chamber to the diffuser and from the diffuser, to the discharging device;
wherein the nozzle is upstream of the mixing chamber and the diffuser is downstream of the mixing chamber;

wherein a pressure of the gas is:
(i) greater than ambient pressure directly upstream of the nozzle but lesser than ambient pressure directly downstream of the nozzle;
(ii) lesser than ambient pressure both directly upstream of the mixing chamber and directly downstream of the mixing chamber; and
(iii) lesser than ambient pressure directly upstream of the diffuser but greater than ambient pressure directly downstream of the diffuser.

2. The method of claim 1 ,
wherein the solid materials comprise water ice in the form of pellets or another comminuted form; and
wherein each of the pellets or each of the solid materials in the another comminuted form are less than 6 mm in size.

3. The method as claimed in claim 1 , wherein the exit speed is from 10 to 30 m/s.

4. The method as claimed in claim 2 , wherein the size of each of the pellets of the water ice is from 2 mm to 6 mm in length.

5. The method as claimed in claim 1 , wherein the cleaning medium is conveyed mechanically to the discharging device.

6. The method as claimed in claim 5 , wherein the cleaning medium is conveyed mechanically to the discharging device by a conveying device comprising a spiral conveyor.

7. The method as claimed in claim 1 , wherein the cleaning medium is conveyed pneumatically to the discharging device.

8. The method as claimed in claim 1 , wherein the jet engine comprises a first compressor stage and an inlet opening, and
wherein an outlet of the at least one discharging device is arranged at a radial spacing from a rotational axis of the engine, which radial spacing corresponds to from 0.5 to 1.2 times a radius of the inlet opening, which is directed upstream, of the first compressor stage.

9. The method as claimed in claim 1 , wherein a main exit direction of the discharging device encloses an angle with a rotational axis of the engine, which angle corresponds substantially to an angle of attack of fan blades of the engine.

10. The method as claimed in claim 1 , wherein the solid material includes particles having different sizes.

11. The method as claimed in claim 1 , wherein the solid materials comprise carbon dioxide in the form of pellets or another comminuted form.

12. The method as claimed in claim 1 , wherein the cleaning medium has solid carbon dioxide and water ice in the mass ratio of from 5:1 to 1:5.

13. The method as claimed in claim 1 , wherein the solid materials are introduced with a mass flow of from 500 to 2500 kg/h.

14. The method as claimed in claim 1 , wherein the cleaning of the jet engine is carried out over a time period of from 1 to 15 minutes.

15. The method as claimed in claim 1 , wherein from 10 to 600 kg of solid material is introduced into the engine during a cleaning operation.

16. The method as claimed in claim 1 , wherein the jet engine comprises a fan, which is rotated at a fan rotational speed of from 50 to 500 min −1 while the cleaning medium is introduced into the jet engine.

17. The method as claimed in claim 1 , wherein the cleaning medium is pneumatically conveyed to the discharging device by way of a carrier gas at a pressure of from 0.5 bar to 2 bar.

18. The method as claimed in claim 1 , wherein the cleaning medium is introduced into the jet engine via a cleaning apparatus comprising the at least one discharging device in addition to a fan, a nozzle, a storage chamber, nozzle, a mixing chamber, and a diffuser.

19. The method as claimed in claim 1 , wherein the cleaning apparatus comprises a scrambler disposed downstream of the diffuser and the method comprises flowing the cleaning medium through the scrambler to comminute the solid materials.

20. A cleaning apparatus for introducing a cleaning medium into a jet engine, the cleaning apparatus comprising:
at least one discharging device;
a fan;
a nozzle;
a storage chamber;
a mixing chamber; and
a diffuser,
wherein the at least one discharging device is configured to introduce the cleaning medium having solid materials into the jet engine, wherein the cleaning medium exits from the discharging device at an exit speed of from 5 to 50 m/s,
wherein the fan is configured to flow a gas into the mixing chamber;
wherein the mixing chamber is configured to receive the solid materials from the storage chamber such that the gas entrains the received solid materials to form the cleaning medium;
wherein the diffuser is configured to receive a flow of the cleaning medium from the mixing chamber,
wherein the discharging device is configured to receive the flow of the cleaning medium from the diffuser,
wherein the nozzle is upstream of the mixing chamber and the diffuser is downstream of the mixing chamber;
wherein the cleaning apparatus is configured such that a pressure of the gas is:
(i) greater than ambient pressure directly upstream of the nozzle but lesser than ambient pressure directly downstream of the nozzle;
(ii) lesser than ambient pressure both directly upstream of the mixing chamber and directly downstream of the mixing chamber; and
(iii) lesser than ambient pressure directly upstream of the diffuser but greater than ambient pressure directly downstream of the diffuser.

21. The cleaning apparatus according to claim 20 ,
wherein the cleaning medium comprises the solid material, which comprises water ice in the form of pellets or another comminuted form; and
wherein each of the pellets or each of the solid materials in the another comminuted form are less than 6 mm in size.

22. The cleaning apparatus as claimed in claim 21 , wherein the mixing device is arranged in a region of increased gas flow speed.

Assignees

• Lufthansa Technik Ag

Inventors

• Giljohann Sebastian
• Appel Holger Stefan
• Deja Dirk

Classifications

• B24C7/0046

  the abrasive material being fed in a gaseous carrier · CPC title

• B08B7/0092 Primary

  by cooling · CPC title

• F01D25/002 Primary

  Cleaning of turbomachines · CPC title

• B64F5/30

  Cleaning aircraft · CPC title

• B24C7/0053

  with control of feed parameters, e.g. feed rate of abrasive material or carrier · CPC title