DE102016206246A1 - Method and device for cleaning turbine blades - Google Patents

Abstract

The invention relates to a method for cleaning turbine blades (80) of a turbine stage (81), in particular a high-pressure turbine stage, of a jet engine (82). Furthermore, the invention relates to a particularly suitable for carrying out the method device (1). The method of cleaning turbine blades (80) of a turbine stage (81) of a jet engine (82) comprises the steps of: a. Heating the turbine blades (80) at least in a cleaning area (71); and b. Cleaning the turbine blades (80) by compressed-gas blasting with a cleaning medium comprising solid carbon dioxide in the cleaning area, wherein the cleaning area (71) is the blade surface which can be reached directly by the compressed-gas jet. The apparatus (1) for cleaning turbine blades (80) of a turbine stage (81) of a jet engine (82), in particular according to a method according to any one of the preceding claims, comprising a cleaning lance (2) with a compressed gas jets with a cleaning medium comprising solid carbon dioxide formed outlet opening (3) at its one end (4) and a supply port (5) for supplying cleaning medium at its other end, which is designed for insertion into a jet engine (82) through a lateral opening (83) that the outlet opening (3) is alignable on a turbine blade (80) of a turbine stage (82).

Description

The invention relates to a method for cleaning turbine blades of a turbine stage, in particular a high-pressure turbine stage, of a jet engine. Furthermore, the invention relates to a particularly suitable for carrying out the method device.

Aircraft jet engines have in known manner one or more compressor stages, a combustion chamber, and one or more turbine stages. In the turbine stages, the hot combustion gases from the combustion chamber release some of their thermal and mechanical energy, which is used to drive the compressor stages. Contamination of an aircraft jet engine can lead to a reduction in efficiency, resulting in increased fuel consumption and thus increased environmental impact. This is especially true when the contaminants form a deposit on the air flowed through parts of an aircraft engine and thereby affect the surface quality.

In particular, in airplanes used in desert regions, there is still a problem that the desert sand (CMAS), which is in the air, is sucked in by the engine and becomes molten due to the high temperatures in the combustion chamber. When hitting the high-pressure turbine blades (HPT blades) arranged downstream of the combustion chamber, the molten sand solidifies again. In addition, extremely fine sand passes into the cooling air bled in the high-pressure compressor from the inside into the internal cooling channels of the high-pressure turbine blades, which open at the profile nose of the blades to form a film cooling, and settles there. Both effects lead to a narrowing or blockage of the cooling air ducts of the high-pressure turbine blades, so that they are no longer sufficiently cooled. Combined with erosion and oxidation effects, the high-pressure turbine blades are significantly faster, and their service life is dramatically reduced, especially when compared to use outside desert regions.

To clean the high pressure turbine blades, it is known in the art to disassemble the affected engine from the aircraft and to overhaul the engine to subject the high pressure turbine blades to a repair cycle involving a cleaning. This engine overhaul is complicated and costly.

From the DE 10 2012 002 275 A1 Furthermore, a method is known in which the aircraft engine can remain on the aircraft for cleaning the high-pressure turbine blades. For this purpose, a cleaning device is introduced into the combustion chamber via a lateral opening of the engine, which is to be removed a jet nozzle for generating a pressurized liquid jet, with the deposits on the high-pressure turbine blades. However, the results of such a process are not always satisfactory.

The invention has for its object to provide a method for cleaning turbine blades of a turbine stage, in particular a high-pressure turbine stage, as well as a device particularly suitable for this, which are improved over the prior art.

This object is achieved by a method according to the main claim and a device according to claim 5. Advantageous developments are the subject of the dependent claims.

• a. Erwärmen der Turbinenschaufeln zumindest in einem Reinigungsbereich; und
• b. Reinigen der Turbinenschaufeln im Reinigungsbereich durch Druckgasstrahlen mit einem Reinigungsmedium umfassend festes Kohlendioxid,

wobei der Reinigungsbereich die unmittelbar vom Druckgasstrahl erreichbare Schaufeloberfläche ist.Accordingly, the invention relates to a method for cleaning turbine blades of a turbine stage of a jet engine, comprising the steps of:

• a. Heating the turbine blades at least in a cleaning area; and
• b. Cleaning the turbine blades in the cleaning area by compressed-gas blasting with a cleaning medium comprising solid carbon dioxide,

wherein the cleaning area is the blade surface which can be reached directly by the compressed gas jet.

Furthermore, the invention relates to an apparatus for cleaning the turbine blades of a turbine stage of a jet engine which is particularly suitable for carrying out the method according to the invention, comprising a cleaning lance with an outlet opening for the cleaning medium at one end and a feed connection for supplying cleaning medium, for solidifying carbon dioxide with a cleaning medium comprising solid carbon dioxide at its other end, which is designed for insertion into a jet engine through a lateral opening, that the outlet opening is aligned with a turbine blade of a turbine stage.

The turbine blades may in particular be the turbine blade of a high-pressure turbine stage.

First, some terms used in the invention will be explained.

The "cleaning area" is defined as "blade surface accessible by the compressed gas jet". This refers to the area of the surfaces of the blades of a turbine stage, to which the Compressed gas jet can hit unhindered and directly. The cleaning region of a turbine stage is dependent in particular on shading effects of adjacent turbine blades of the same turbine stage and / or upstream stages, as well as on the orientation and width of the compressed gas jet. The cleaning area can be determined individually for different cleaning tasks (eg cleaning of the profile nose), for example by changing the compressed-gas jet guide. Ends in the cleaning area of a blade, for example. Cooling air ducts to form a film cooling during operation of the engine or there are other openings provided, the compressed gas jet can also get into the cooling air ducts or other openings, which then the inner wall of the cooling air ducts or other openings can be cleaned.

The inventive method achieved over the prior art, an improved cleaning effect in the cleaning of turbine blades of a turbine stage of a jet engine. Due to the solid carbon dioxide in the cleaning medium is already compared to a cleaning with liquid (see. DE 10 2012 002 275 A1 ) achieved increased cleaning effect. However, the cleaning effect is increased even further by the temperature difference between the cleaning medium and the cleaning area being increased by the preceding heating of at least the cleaning area of the turbine blade, which contributes to the break-up and spalling of impurities. The device according to the invention is designed for the use of cleaning medium comprising solid carbon dioxide and in particular allows the cleaning of turbine blades of a turbine stage, while the jet engine remains on the aircraft (on-wing).

It is basically possible that the device liquid carbon dioxide is supplied as a precursor of the cleaning medium. The liquid carbon dioxide then at least partially solidifies on leaving the outlet and forms a solid component in the form of carbon dioxide flakes. If liquid carbon dioxide comes into contact with ambient air in which it exits, for example, from a nozzle arranged at the outlet opening, a part readily assumes the form of gas. Another part of the carbon dioxide gets stuck in the form of flakes. This is due to the fact that the part of the carbon dioxide passing from the liquid to the gaseous state binds a great deal of heat, which is removed from the remaining liquid part, as a result of which the temperature of the carbon dioxide drops to the point at which the carbon dioxide solidifies.

However, it is preferred if the device supplied to the cleaning medium directly solid carbon dioxide - also called dry ice - which is promoted by a propellant gas. The solid carbon dioxide can be provided in the form of pellets, which are sprayed with the aid of the propellant gas, such as. Air or CO2 from the outlet opening. Pellets can be produced in a so-called pelletizer from liquid CO ₂ and are well storable. It can be provided that already prefabricated pellets are conveyed by means of the propellant gas to the outlet opening. However, it is also possible for the pellets to be formed from liquid carbon dioxide immediately before they are used, in order subsequently to be conveyed with the propellant gas to the outlet opening. In both cases, the solid carbon dioxide exits the outlet and enters the engine to be cleaned. The outlet opening must be suitably designed for a corresponding cleaning medium comprising solid carbon dioxide as a solid component.

It is preferred if the jet pressure during the compressed gas jet is between 6 and 16 bar, preferably between 8 and 12 bar, more preferably between 9 and 10 bar. The cleaning range of the turbine blades is preferably at a temperature of 50 to 450 ° C, more preferably at a temperature of 120 to 300 ° C, more preferably at a temperature of 180 to 230 ° C. If the cleaning medium is based on carbon dioxide pellets, the amount of dry ice included in the cleaning medium is preferably 50 to 200 kg / h, more preferably 70 to 200 kg / h, more preferably 180 to 200 kg / h. The jet time per cleaning area of a single turbine blade is preferably 0.5 to 20 seconds, more preferably 1 to 10 seconds, more preferably 2 to 4 seconds.

The turbine blades of the jet engine can be cleaned one at a time, whereby the turbine stage is rotated stepwise, so that there is always a cleaning area of an engine blade in the compressed gas jet, which is moved at least once over the entire cleaning area in one cycle. Alternatively, it is possible that a stochastic cleaning of all engine blades takes place together, for this purpose, the turbine stage continuously rotated and the compressed gas jet is continuously moved back and forth in a direction perpendicular to the axis of rotation of the turbine stage, so after a determined period of time, the compressed gas jet at least once over every cleaning area of each turbine blade of the turbine stage was performed.

The heating of the turbine blades preceding the actual cleaning of the turbine blades can be achieved by hot or hot gas, preferably compressed air or combustion gas (in particular the exhaust air of an external burner, such as a propane burner), laser radiation and / or by inductive heating. Will warm or hot gas to heat the Used turbine blades, the gas can be introduced via a comparable with the cleaning lance device to the turbine blades. It is also possible to use this directly the cleaning lance, in which case first warm or hot gas flows through the cleaning lance before the cleaning medium is supplied. The warm or hot gas can flow through the same channel in the cleaning lance through which the cleaning medium then flows. However, the cleaning lance can also have a separate hot gas duct designed for this purpose. If laser radiation or inductive heating is provided for heating the turbine blades, the light guides or electrical lines required for this purpose can be guided directly along the cleaning lance. Hot gas duct, light guide and / or the electrical lines are designed so that a turbine blade arranged in the region of the outlet opening of the cleaning lance turbine blade can be heated.

Even if the method according to the invention can be carried out on a dismantled and possibly partially dismantled jet engine, it is preferred if the method is carried out on a jet engine (on-wing) located on the aircraft. The complex disassembly and / or (partial) decomposition of the engine can be omitted.

The cleaning lance is preferably adapted for insertion into a jet engine through a borescope port, an orifice for receiving a spark plug, or an orifice for a fuel injector of the engine, and preferably includes a mounting device for securing the cleaning lance to the outside of the jet engine opposite the introduction port can. Corresponding openings are present on the jet engine, in particular in the region of the combustion chamber housing, and can be used to introduce the cleaning lance after removing a cover or the components respectively arranged in the openings for the operation of the engine, such as spark plugs or injection nozzles. The fixing device may in particular cooperate with connection components provided on the outside of the engine, to which covers and / or components, such as those mentioned above, are attached, in order to secure the cleaning lance opposite the introduction opening.

The fastening device preferably comprises a guide mechanism with which the cleaning lance can be moved after fastening of the fastening device on the jet engine at least in the direction of the opening through which the cleaning lance is guided. A corresponding mobility is advantageous for the above-described stepwise cleaning of the individual turbine blade and for the stochastic cleaning of all engine blades together. Preferably, the guide mechanism further allows the cleaning lance to be moved in the direction of the engine axis and / or pivoted about an axis perpendicular to the engine axis. With a thereby achievable adjustability of the position of the outlet opening of the cleaning lance, the cleaning range of the individual turbine blades or the achievable by the compressed gas jet blade surface can be adjusted.

For (partial) automation of the cleaning process is preferred if the guide mechanism at least for the movement of the cleaning lance in the direction of the opening through which the cleaning lance is guided, has a controllable by a control device drive.

For a stochastic cleaning of all engine blades of an engine stage together, the engine stage can then be rotated by the engine-side starter or a separate, preferably the cleaning device associated drive unit in rotation and the controller performs the cleaning lance or its outlet opening so that after a certain period of time the compressed gas jet at least once over each cleaning area of each turbine blade of the turbine stage.

It is preferred if the cleaning device has a drive unit for rotating the turbine stage with the turbine blades to be cleaned, wherein the control device is designed to control the controllable drive of the guide mechanism and the drive unit for rotation of the turbine stage, that the turbine blades of the jet engine are cleaned one after another in that the turbine stage is rotated step by step, so that there is always the cleaning area of an engine blade in the compressed gas jet, which is moved at least once over the entire cleaning area in one cycle.

The outlet opening of the cleaning lance may have a deflection device with which the compressed gas jet is deflected relative to the axis of the cleaning lance. The deflection device may comprise a curved pipe section or a baffle plate. The deflection device may be formed integrally with the cleaning lance. But it is also possible that the deflection device as attachable to the cleaning lance cap or as part of a protective cover of the cleaning lance, which protects the components of the engine from damage caused by the cleaning lance form. In this case, the deflection device can be comparatively easy to change and / or replace.

It is preferred if a Laval nozzle is integrated in the cleaning lance, which is preferably arranged near the outlet opening. Thanks to the Laval nozzle, solid carbon dioxide particles already present in the cleaning medium can be further accelerated, thus increasing the cleaning effect. The Laval nozzle can be adapted to a possible curve of the cleaning lance and thus also be bent or curved.

It is preferred if an optic is provided on the cleaning lance, through which at least the cleaning area of a turbine blade can be seen. If a corresponding optics is provided, a separate endoscope is no longer required, especially for on-wing cleaning, for the assessment of at least the cleaning area.

The cleaning lance and / or the protective cover of the cleaning lance may be formed at least in partial areas such that they are elastically deformable at ambient temperature, wherein this elasticity preferably decreases during the supply of the cleaning medium. The same can be achieved by suitable material which has the desired elasticity at ambient temperature, but stiffened at lower temperatures which inevitably result when the cleaning medium is supplied due to the solid or at least liquid carbon dioxide contained therein. The elasticity at ambient temperature makes it easier to introduce the cleaning lance into the engine. By stiffening the resilient portions of the cleaning lance and / or the protective coating upon delivery of the cleaning medium (i.e., the resilience decreases), vibrations and vibrations in the cleaning lance can still be minimized during the cleaning process.

The apparatus for cleaning turbine blades of a turbine stage of a jet engine further preferably comprises a dry ice reservoir or a dry ice generator for carbon dioxide pellets for the cleaning medium.

The invention will now be described by way of advantageous embodiments with reference to the accompanying drawings. Show it:

1 a schematic representation of a first embodiment of an inventive device for cleaning turbine blades of a turbine stage of a jet engine;

2 : a detailed representation of the outlet opening of the cleaning lance of the device 1 ;

3 : a schematic representation of a detail of the cleaning lance of the device 1 ;

4 : a detailed representation of the fastening device of the cleaning device 1 ;

5 : A schematic representation of the cleaning of a turbine blade with the cleaning device off 1 ; and

6a -D: Variants for the design of the cleaning lance of the cleaning device 1 ,

In 1 is a schematic representation of a device according to the invention 1 for cleaning turbine blades 80 a turbine stage 81 a jet engine 82 shown. The jet engine also shown only schematically 82 is attached directly to the aircraft (not shown). The following statements therefore relate in particular to on-wing cleaning.

The device 1 for cleaning turbine blades 80 includes a cleaning lance 2 with an outlet opening formed for pressurized gas jetting with a cleaning medium comprising solid carbon dioxide 3 at one end 4 (see. 2 ). At the other end 6 is a supply connection 5 arranged to supply cleaning medium.

The cleaning lance 2 is by a originally intended for a spark plug side opening 83 in the case 84 the combustion chamber 85 introduced, with one end 4 through the turbine vanes 86 The result is that the outlet opening 3 the cleaning lance 2 on the turbine blades 80 the first high-pressure turbine stage 81 is aligned.

The cleaning lance 1 is about a fastening device 7 on the housing 84 the combustion chamber 85 attached (see also 4 ). The fastening device 7 engages in the thread 87 , which is intended for the attachment of the spark plug, a. For easy installation of the fastening device 7 is a drive profile 8th , preferably a hexagonal profile with a standard key width, provided.

The fastening device 7 comprises a guide mechanism, not shown, with which by a controllable electric drive, the cleaning lance after attachment of the fastening device 7 at the jet engine 82 in through the double arrow 90 indicated direction of the opening 83 through which the cleaning lance 2 is guided, lets move, bringing also the exit opening 3 moves accordingly. The control signals and power supply for the electric drive via the connecting cable 9 ,

The cleaning lance 2 includes a core tube 10 , which with a protective cover 11 is provided to the components of the engine 82 on contact with the cleaning lance 2 to protect against damage (cf. 2 ). Besides, is in the area of the end 4 with the outlet 3 around the inside of the cleaning lance 2 a Laval nozzle 12 provided in the illustrated embodiment in a curved region of the core tube 10 arranged and thus also executed curved (see. 3 ).

The device 1 for cleaning turbine blades 80 further comprises a drive unit 13 to the rotation of the engine 82 and thus also the turbine stage 81 with the turbine blades to be cleaned 80 , The drive unit 13 is via an engine-side transmission 14 directly with the engine axle, at the inter alia the turbine stage in question 81 attached, coupled.

Both the drive unit 13 for rotation of the turbine stage 81 as well as the fastening device 7 with the electric drive arranged therein for moving the cleaning lance 6 are with a control device 15 coupled and controlled by this. Control cables are in 1 indicated by dashed arrows.

The device 1 further comprises one of the control device 15 controlled dry ice jet generator 16 based on solid carbon dioxide pellets from the dry ice reservoir 17 and the air compressor 18 provided compressed air can form a cleaning medium comprising solid carbon dioxide.

The air compressor 18 is also equipped with a heater 19 connected, which also from the controller 15 is controlled and the compressed air can heat to hot gas when needed.

All electrically operated components 7 . 13 . 15 . 16 . 18 . 19 be from a power generator 20 powered by a mobile, independent of power connections use of the device 1 allows (in 1 by solid arrows starting from power generator 20 indicated).

For cleaning a turbine blade 80 This is first with hot gas from the heater 19 heated. The hot gas can pass directly through the cleaning lance 2 on the engine blade 80 be applied. Alternatively, it is possible to provide a separate hot gas lance (not shown), with which the hot gas in the position of the turbine blade 80 in which the subsequent cleaning is carried out, is applied. It is also possible that hot gas via a hot gas lance (not shown) on a turbine blade 80 is applied in a different position and the turbine blade 80 subsequently by rotation of the turbine stage 81 over the drive motor 13 is moved to the cleaning position.

Subsequently, the turbine blade 80 by compressed gas jets with one of the dry ice jet generator 16 generated cleaning medium comprising solid carbon dioxide and air purified as a propellant gas. In 5 is an example of the situation during the cleaning of the turbine blades 80 represented with the compressed gas jet. As already described is the end 4 the cleaning lance 2 with the outlet 3 between the turbine vanes 86 passed through, so that by the in 5 by dashed lines 70 enclosed pressurized gas jet basically unhindered on the turbine blades 80 can hit. Depending on in 5 drawn compressed gas jet angle α can be reached directly from the compressed gas jet blade surface - ie the cleaning area 71 the turbine blade 80 - by shading effects of adjacent turbine blades 80 ' be impaired. In the cleaning area 71 ending cooling air ducts 91 can also be cleaned. The in 5 drawn distance A between the outlet opening 3 and the turbine stage input level is at least 10 mm.

The control device 15 is formed in the illustrated embodiment, the cleaning lance 2 over the fastening device 7 to move so that the entire, reachable by the compressed gas jet cleaning area 71 the turbine blade 80 is cleaned from the compressed gas jet. This is the cleaning lance 2 in the direction 90 the opening 83 through which the cleaning lance 2 is guided at least once over the entire blade length.

Is that a turbine blade 80 cleaned, controls the control device 15 the drive motor 13 such that the turbine stage 81 around a turbine blade 80 is rotated further, so the previously cleaned turbine blade 80 adjacent turbine blade 80 herself with her cleaning area 71 located in the compressed gas jet. The turbine stage 81 is thus clocked gradually rotated, so there is always a cleaning area 71 a power shovel 80 located in the compressed gas jet, the in a cycle at least once over the entire cleaning area 71 is moved.

The actual cleaning area 71 the turbine blade 80 is inter alia significantly dependent on the compressed gas jet angle α. In principle, at a higher compressed gas jet angle α (up to a maximum of 90 °), a better cleaning of the leading edge of the turbine blades 80 can be achieved.

To adjust the compressed gas jet angle α, if necessary, the outlet opening 3 the cleaning lance 2 a deflection device 21 exhibit. In 6a -D are different variants of corresponding deflection devices 21 shown.

In the variant according to 6a is the deflection device 21 as part of the protective cover 11 the cleaning lance 2 formed over the core tube 10 protrudes and is bent. Also in the variant according to 6b is the coating 11 over the core tube 10 out. However, the coating is 11 in this case only bevelled so that the resulting outlet opening 3 ' runs parallel to the turbine stage input level.

In the variant according to 6c has the core tube 10 at its one end a baffle plate 22 on, with the deflector 21 is formed. In the variant according to 6d is the end of the core tube 10 bent around the deflection device 21 to build. Although not shown, can in the embodiments according to 6c and d also a protective coating 11 be provided.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012002275 A1 [0005, 0013]

Claims (14)

Method for cleaning turbine blades ( 80 ) a turbine stage ( 81 ) of a jet engine ( 82 ), with the steps: a. Heating the turbine blades ( 80 ) at least in a cleaning area ( 71 ); and b. Cleaning the turbine blades ( 80 by pressurized gas blasting with a cleaning medium comprising solid carbon dioxide in the cleaning area, wherein the cleaning area ( 71 ) which is directly accessible from the compressed gas jet blade surface. A method according to claim 1, characterized in that the method is carried out with one, several or all of the following parameters: - jet pressure during the compressed gas jets: 6-16 bar, preferably 8-12 bar, more preferably 9-10 bar; - temperature of the cleaning region after heating: 50-450 ° C, preferably 120-300 ° C, more preferably 180-230 ° C; Dry ice amount: 50-200 kg / h, preferably 70-200 kg / h, more preferably 180-200 kg / h; and / or jet time per cleaning area of a single turbine blade: 0.5-20 s, preferably 1-10 s, more preferably 2-4 s. Method according to one of the preceding claims, characterized in that the turbine blades ( 80 ) of the jet engine ( 82 ) are cleaned one after another, in which case the turbine stage ( 81 ) is rotated step by step so that there is always a cleaning area ( 71 ) an engine blade ( 80 ) is located in the compressed gas jet, which in one cycle at least once over the entire cleaning area ( 71 ) or that a stochastic cleaning of all engine blades ( 80 ) takes place together, in which case the turbine stage ( 81 ) continuously rotated and the compressed gas jet continuously in a direction perpendicular to the axis of rotation ( 88 ) of the turbine stage ( 81 ) is moved back and forth, so that after a determinable period of time the compressed gas jet at least once completely over each cleaning area ( 71 ) of each turbine blade ( 80 ) of the turbine stage ( 81 ) was performed. Method according to one of the preceding claims, characterized in that the turbine blades ( 80 ) are heated by means of hot or hot gas, preferably compressed air or combustion gas, laser radiation and / or by inductive heating. Contraption ( 1 ) for cleaning turbine blades ( 80 ) a turbine stage ( 81 ) of a jet engine ( 82 ), in particular according to a method according to one of the preceding claims, comprising a cleaning lance ( 2 ) with an outlet opening formed for compressed-gas jetting with a cleaning medium comprising solid carbon dioxide (US Pat. 3 ) at one end ( 4 ) and a supply connection ( 5 ) for the supply of cleaning medium at its other end, which is so for insertion into a jet engine ( 82 ) through a lateral opening ( 83 ) is formed, that the outlet opening ( 3 ) on a turbine blade ( 80 ) a turbine stage ( 82 ) is alignable. Apparatus according to claim 5, characterized in that the cleaning lance ( 2 ) for insertion into the jet engine ( 82 ) is formed by a Boroskopöffnung, an opening for receiving a spark plug or an opening for a fuel injection nozzle of the engine, and preferably a fastening device ( 7 ), with which the cleaning lance ( 2 ) on the outside of the jet engine ( 82 ) opposite the introduction opening ( 83 ) is attachable. Apparatus according to claim 6, characterized in that the fastening device ( 7 ) comprises a guide mechanism with which the cleaning lance ( 2 ) after attachment of the fastening device ( 7 ) at the jet engine ( 82 ) in the direction of the opening ( 83 ), wherein the guide mechanism preferably continues to move the cleaning lance ( 2 ) in the direction of the engine axis ( 88 ) and / or pivoting about an axis perpendicular to the engine axis ( 88 ). Apparatus according to claim 7, characterized in that the guide mechanism at least for the movement of the cleaning lance ( 2 ) in a direction radial to the engine axis ( 88 ) one, above a control device ( 15 ) has controllable drive. Apparatus according to claim 8, characterized in that the cleaning device ( 1 ) a drive unit ( 13 ) for rotation of the turbine stage ( 81 ) with the turbine blades to be cleaned ( 80 ), wherein the control device ( 15 ) preferably in such a way for driving the controllable drive of the guide mechanism and the drive unit ( 13 ) for rotation of the turbine stage ( 81 ) is formed such that the turbine blades ( 80 ) of the jet engine ( 82 ) can be cleaned one after the other by the turbine stage ( 81 ) is rotated step by step, so that always the cleaning area ( 71 ) an engine blade ( 80 ) is located in the compressed gas jet, which in one cycle at least once over the entire cleaning area ( 71 ) is moved. Device according to one of claims 5 to 9, characterized in that the outlet opening ( 3 ) of the cleaning lance ( 2 ) a deflection device ( 21 ) for deflecting the compressed gas jet with respect to the axis of the cleaning lance ( 2 ), wherein the deflection device ( 21 ) preferably as an attachable cap or as part of a protective cover ( 11 ) of the cleaning lance, which is the components of the engine ( 82 ) from damage by the cleaning lance ( 2 ), is formed. Device according to one of claims 5 to 10, characterized in that in the cleaning lance ( 2 ) a Laval nozzle ( 12 ) is preferably integrated near the outlet opening ( 3 ) is arranged and further preferably bent or curved. Device according to one of claims 5 to 11, characterized in that at the cleaning lance ( 2 ) an optics is provided by which at least the cleaning area ( 71 ) of a turbine blade ( 80 ) is visible. Device according to one of claims 5 to 12, characterized in that for the preparation of the cleaning medium, a dry ice reservoir ( 17 ) or a dry ice generator for carbon dioxide pellets is provided. Device according to one of claims 5 to 13, characterized in that the cleaning lance has a separate hot gas channel and / or guided along the cleaning lance light guide or electrical lines.

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