System for washing an aero gas turbine engine

Abstract

System for washing a gas turbine engine. The system comprises a spray device including at least one nozzle adapted to inject liquid into an inlet of said engine during a washing operation; a wash unit adapted to distribute said liquid to said spray device; and a positioning device adapted to move said spray device in three dimensions, thereby enabling a positioning of said spray device in a washing operation position in said three dimensions relative said engine inlet without any contact between the spray device and the engine. The invention further relates to a vehicle for making the inventive system mobile and to a mobile system for serving a gas turbine engine comprising a mobile vehicle carrying the washing system and a liquid collecting unit comprising a collecting device adapted to collect waste wash liquid emanating from the engine during a washing operation of the engine.

Claims

1. A washing system for washing a gas turbine engine, said washing system being arranged on a mobile vehicle and comprising: a spray device including: a carrying body; a plurality of nozzles attached to the carrying body and adapted to inject liquid directly into an inlet of said engine during a washing operation, wherein the plurality of nozzles are arranged outward from the carrying body; and an optical sensing device adapted to monitor the washing operation of the engine, wherein the optical sensing device is arranged on the carrying body and inward from the plurality of nozzles; a wash unit adapted to distribute said liquid to said spray device; a positioning device adapted to move said spray device in three dimensions, thereby enabling a positioning of said spray device in a washing operation position in said three dimensions relative the inlet of said engine without contact between the spray device and the engine during the washing operation, wherein the optical sensing device is supported by the carrying body so as to be movable in concert with the plurality of nozzles when moved by the positioning device; and a control panel adapted to enable an operator to adjust the position of said spray device in three dimensions relative the inlet of said engine by means of said positioning device.

2. The washing system according to claim 1, wherein said positioning device comprises a robotic arm including joints enabling a movement of said spray device in said three dimensions.

3. The washing system according to claim 1, wherein said optical sensing device is connected to said control panel and is adapted to deliver a view of the inlet of said engine to an operator of said washing system at a monitor.

4. The washing system according to claim 1, wherein said optical sensing device comprises a camera or a fiber optic device.

5. The washing system according to claim 1, wherein said spray device further comprises a distance measuring device adapted to measure a distance between said spray device and said engine.

6. The washing system according to claim 5, wherein said distance measuring device is connected to said control panel and is adapted to deliver an indication of the distance between said spray device and said engine, thereby informing an operator of a present distance between said spray device and said engine by means of a monitor.

7. The washing system according to claim 5, wherein said distance measuring device is an ultra sound sensing device comprising a transmitter adapted to emit a sound beam and a receiver adapted to receive said beam, wherein said distance is estimated by a time difference for said beam to be transmitted from said transmitter to said receiver.

8. The washing system according to claim 5, wherein said distance measuring device is an optical measuring device comprising a transmitter adapted to emit a laser beam and a receiver adapted to receive said beam, wherein said distance is estimated by a time for said beam to be transmitted from said transmitter to said receiver.

9. The washing system according to claim 5, wherein said distance measuring device further comprises an alarm means adapted to emit an alarm signal if said measured distance decreases below a predetermined value.

10. The washing system according to claim 1, wherein said spray device further comprises an illumination means.

11. The washing system according to claim 1, wherein the optical sensing device is configured with a field of view that overlaps with the inlet of said engine into which the spray device injects liquid during the washing operation.

12. A liquid wash system comprising: a mobile unit; a wash unit associated with the mobile unit for providing wash liquid; a plurality of nozzles for streamline injecting wash liquid provided by the wash unit directly into an engine inlet without contact between the wash unit and an engine inlet cowling during a washing operation, wherein the plurality of nozzles are supported in an array surround a central body; and one or more controls for use in regulating the wash unit, wherein one of the one or more controls comprises an optical sensing device adapted for monitoring the washing operation, wherein the optical sensing device is located at the central body and inward from the plurality of nozzles.

13. The liquid wash system of claim 12, further comprising an articulating arm for use in positioning the plurality of nozzles, wherein the articulating arm is operable via one of a hydraulic, a pneumatic, an electrical, a mechanical, or a hand-driven operating means.

14. The liquid wash system of claim 12, wherein the wash unit comprises one or more tanks for storing wash liquid.

15. The liquid wash system of claim 14, wherein the wash unit comprises two or more tanks, at least one of the two or more tanks for storing chemical wash solvents, and at least another one of the two or more tanks for storing water only.

16. The liquid wash system of claim 14, wherein the wash unit further comprises one or more heaters for heating the wash liquid in one or more of the one or more tanks.

17. The liquid wash system of claim 16, wherein the wash unit further comprises one or more pumps for raising a pressure in one or more of the one or more tanks, thereby enabling the wash unit to provide pressurized washing liquid.

18. The liquid wash system of claim 17, wherein the one or more controls comprises at least one of a liquid pressure meter, a liquid flow meter, a liquid temperature meter, and a pump on-off switch.

19. The liquid wash system of claim 12, wherein one of the one or more controls further comprises a distance measuring device for measuring a distance between the plurality of nozzles and an engine being washed.

20. The liquid wash system of claim 12, wherein the plurality of nozzles comprise an annular manifold.

21. The liquid wash system according to claim 12, wherein the optical sensing device is configured with a field of view that overlaps with the engine inlet into which the plurality of nozzles streamline inject liquid during the washing operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention will now be described in greater detail with reference to the accompanying drawings, in which:

(2) FIG. 1 shows the cross section of a two shaft turbofan engine with manifold and nozzles for washing according to prior art.

(3) FIG. 2 shows the manifold installed in the inlet of an aero engine according to prior art.

(4) FIG. 3 shows the wash unit with the no-contact spray head according to the invention.

(5) FIG. 4a show the application of the invention when washing an under wing mounted engine.

(6) FIG. 4b shows the application of the invention when washing a tail mounted engine.

(7) FIG. 5 shows spray head details according to the invention.

(8) FIG. 6 shows an alternative embodiment of the spray head.

(9) FIG. 7a shows washing of the fan of a turbofan engine according to the invention.

(10) FIG. 7b shows washing of the core engine of a turbofan engine according to the invention.

(11) FIG. 8 shows how the wash procedure is controlled by means of a camera and distance measuring device installed on the spray head.

(12) FIG. 9 shows the universal, no-contact spray head according to the invention.

(13) FIG. 10 shows the universal, no-contact spray head and a waste water collecting device with waste water treatment for reuse of the wash liquid.

DETAILED DESCRIPTION

(14) The invention disclosed heir in describes a system including a manifold that has no contact with the inlet air cowling. Having no contact with the inlet air cowling eliminates the issue of manufacturing adapted manifolds to the large number of aircraft engine inlet cowlings. Further, the manifold disclosed heir in is universal in the meaning that it may service small engines as well as large engines as the manifold has multi size capabilities. A manifold having multi size capability eliminates the issue of manufacturing many manifolds for aircraft engines of varying size.

(15) FIG. 3 shows the application of the universal and non-contact manifold according to the invention. An aero engine 1 installed on an aircraft (not shown) is subject to washing. Wash unit 31 is a unit for delivering wash liquid to a spray head 33. Spray head 33 includes a manifold 36 for distributing the liquid to nozzles (not shown for clarity) on manifold 36. The nozzles inject the wash liquid into the engine inlet. The nozzles may either atomize the liquid or inject liquid as a solid stream. Wash unit 31 comprises of the necessary equipment and components for enabling washing such as tanks for storing wash liquid, heaters for heating the liquid, a pump for raising the liquid pressure, controls required to enable and monitor the wash operation. The liquid may be water only or water with chemicals or chemicals only such as solvents. Typically the liquid is heated as washing with hot liquid as hot liquid enhances the wash result. The wash liquid is pressurized by the pump for distribution to the nozzles. The controls typically comprise of liquid pressure meter, liquid flow meter, liquid temperature meter and pump on-off switch. Wash unit 31 may be mobile as to make it practical for use for washing aircraft engines at an airport. Wash unit 31 may then be part of a vehicle 32. Vehicle 32 may be a hand towed cart or a motor driven cart or a person carrying vehicle such as a small truck. Alternatively, wash unit 31 may not be mobile.

(16) Spray head 33 is held in fixed position in the inlet of engine 1 by robotic arm 34. Robotic arm 34 is at one end installed on wash unit 31 and has spray head 33 on the other end. Robotic arm 34 has at least one articulated joint and a wrist enabling appropriate positioning of spray head 33 in inlet 301 of engine 1. The robotic arm is moveable with at least three degrees of freedom. Robot arm 34 operates by a hydraulic or pneumatic or electric or mechanically hand driven operating device (not shown) or may be moved by hand force. In an embodiment of the present invention, the robotic arm may comprise one or several telescopic parts. For example, a part between two joints may be telescopic.

(17) Spray head 33 is sized to be smaller than the opening of inlet 301. Spray head 33 is preferably positioned in inlet 301 by operating robotic arm 34 from a control panel (not shown) by an operator. Spray head 33 is positioned essentially in the centre of the opening of inlet 301. When spray head 33 is in its appropriate position there is no contact between the aircraft and the spray head or any other parts of the washing device. Wash unit 31 delivers the pressurized wash liquid to spray head 33 via conduit 35 where conduit 35 comprises of a flex hose or similar device for that service. In spray head 33 the liquid is distributed to a multiple of nozzles via manifold 36 where the nozzles have the purpose of injecting the wash liquid into the engine.

(18) FIG. 4a exemplifies the invention when in position for use when washing an engine of an under wing engine type aircraft. Similar parts are shown with the same reference numbers as FIG. 1 and FIG. 3. Aircraft 40 has a wing 41 on which engine 1 is installed. Vehicle 32 with the wash unit is parked adjacent to the engine. Vehicle 32 is preferably parked at one side of the engine as not to be standing in the direct air stream during washing. This is to avoid that any loose objects on the vehicle may accidentally be brought by the air stream into the engine. Robotic arm 34 holds the spray head with its manifold 36 in position in the engine inlet. There is no contact between the aircraft and the manifold or any other parts of the wash unit. FIG. 4b exemplifies the invention when in position for use when washing an engine of a tail engine type aircraft. Similar parts are shown with the same reference numbers as FIG. 1 and FIG. 3. Vehicle 32 with the wash unit is parked adjacent to the engine. Robotic arm 34 holds the spray head and its manifold 36 in position in the engine inlet. There is no contact between the aircraft and the manifold or any other parts of the wash unit. The invention is not limited to the illustrations in FIG. 4a and FIG. 4b as there are many other aircraft of different designs where the invention is equally applicable. Further, there may be aircraft where there is an advantage to arrange for the wash equipment to take support by the cowling or other parts of the aircraft.

(19) FIG. 5 shows the details of spray head 33. Spray head 33 is shown in a perspective view where the arrow shows the direction of the engine air flow. Similar parts are shown with the same reference numbers as FIG. 3. Spray head 33 comprises of a unit with essentially rotational symmetry with axis 501 being the centre of symmetry. When spray head 33 is in position for washing axis 501 is essentially aligned with the engine shaft centre of symmetry. Spray head 33 has a central body 50. Body 50 has a front end 58 faced towards the engine. Body 50 has a rear end 59 opposite to front end 58. Rear end 59 is connected to robotic arm 34. Body 50 includes optical sensing device 55 used as an aid for positioning spray head 33 and for monitoring the wash operation. Optical sensing device 55 is directed essentially towards the engine inlet. Optical sensing device 55 may comprise of a camera where the camera view can instantaneously be viewed by the operator at the control panel. Alternatively, the optical sensing device may comprise of a fibre optic device with the same purpose as the camera. Alternatively, there are other means of recoding the view form the spray head. Optical sensing device 55 serves the purpose to deliver a view of the engine inlet to the operator. The camera view is used for helping the operator to align the spray head with the engine shaft centre by manoeuvring the robotic arm from the operator's control panel. Further, the camera view enables the operator to position the spray head at the appropriate distance upstream of the engine. Further, the camera view enables the operator monitor the washing process by delivering a view from the engine centre line during washing. Further, the camera view helps the operator take decision in adjusting any wash parameter from the view that the camera delivers. Further, the camera view is a safety improving device as the operator may stop the wash process as of anything he observes in the camera.

(20) Body 50 in FIG. 5 include a distance measuring device for measuring the distance to the engine. Typically the distance measuring device comprises of a transmitter 56 and a receiver 57. The distance measuring device could comprise of a sound sensing device such as an ultra sound sensing device where the transmitter emits a sound beam which reflect on the engine nose bullet and where the reflected beam is received by the receiver. The distance from the transmitter and receiver is then estimated by the time difference for the signal from the transmitter to the receiver. Alternatively, the distance measuring device could be an optical measuring device such as a laser where the transmitter emits a laser beam which reflects on the engine nose bullet and is received by the receiver. Alternatively, there are other distance measuring devices that could be used. The recorded distance is delivered to the operating panel where the operator will use the information when adjusting the appropriate position of the spray head upstream of the engine. During washing the measured distance helps the operator control the wash process by reporting any changes in distances. The distance measure helps the operator take decision in adjusting any wash parameter if he finds the distance not to be appropriate. The distance measuring device is a safety improving device as the operator may stop the wash process if he finds the distance is not safe. The distance measuring device may include alarms which emit an alarm signal in form of an acoustic sound or a light flash if the distance is out of range. For example, if the measured distance decreases below a predetermined value. In one embodiment, this limit value can be adjusted by the operator by means of the control panel.

(21) Body 50 include a lamp 52 for illuminating the engine inlet. The illumination improves the view from the camera as well as the view from direct eye contact with the engine inlet. Body 50 may include other device for improving the safety or for improving the wash operation.

(22) As the man skilled within the art easily realizes, can each of the following features: the optical sensing device 55, the distance measuring device 56, 57, or the lamp 52 be used independently of the others. That is, the spray head 33 may, for example, only include the optical sensing means 55 or only the distance measuring device 56, 57.

(23) Spray head 33 in FIG. 5 shows the manifold as a ring shaped tube, i.e. a torus. Liquid is pumped from the wash unit (not shown) via a hose (not shown) to manifold 36. Manifold 36 is essentially circular with the circle centre aligned with axis 501. The plane of manifold 36 is essentially perpendicular to axis 501. Manifold 36 is connected to body 50. Manifold 36 has multiple nozzles arranged around the manifold for different wash services. For example, Nozzle 53 serves the purpose of washing the engine fan. Nozzle 54 serves the purpose of washing the core engine. Nozzle 510 serves the purpose of washing the nose bullet. Nozzle 511 serves the purpose of washing the cowling. In addition to nozzles 53, 54, 510 and 511 the manifold may comprise of other nozzles (not shown) for washing other engine details. Manifold 36 has at least one nozzle 54. The nozzles may atomize the liquid into a spray of droplets. Alternatively, the nozzles may deliver the liquid as a non-atomized jet. The objective of using ring shaped manifolds is that the manifolds may be manufactured from one tube which is bent into a ring requiring only one joint (one weld). This is an advantage to alternative designs requiring many more joints. Any reduction in joints is regarded as a safety feature as joints may brake and can cause damage if loosened parts enter the engine. Further, the ring shaped manifold is considered safe as any accidental contact between the manifold and any aircraft parts would not imply contact with any sharp edges. Alternatively may the manifold be equipped with a cushion such as rubber foam material (not shown) as to pick up any force in case of an accidental contact with the engine.

(24) FIG. 6 shows an alternative embodiment of the spray head. Similar parts are shown with the same reference numbers as FIG. 3 and FIG. 5. The ring shaped manifold is here replaced by pipes 61 holding the nozzles in position. Alternatively, the manifold can be made differently.

(25) FIGS. 7a, 7b and 8 shows the application of the invention when washing a turbofan engine. Similar parts are shown with the same reference numbers as previous figures. FIG. 7a shows the washing of the fan of turbofan engine 1 by use of nozzles for washing of the fan. During washing the fan is forced to rotation by the use of the engine starter motor. Nozzle 53 is atomizing the wash liquid into spray 71. The nozzles have a spray pattern resulting in a distribution of liquid limited on one side by streamline 75 and on the other side by streamline 76. The spray's distribution at the leading edge of fan blade 72 is essentially equal to the total blade length limited by tip point 702 and hub point 701. The spray thus covers the whole blade length. Manifold 51 may comprise of only one nozzle 53 which then only covers a portion of the engine inlet. Wetting of the whole fan is then accomplished by the rotation of the fan. FIG. 7b shows the washing of the core engine of turbofan engine 1. During washing the engine shaft is rotated by the use of the starter motor. Nozzle 54 is atomizing the wash liquid into spray 73. The nozzles have a spray pattern resulting in a distribution of liquid limited on one side by streamline 77 and the other side by streamline 78. The purpose of the spray is to deliver liquid into core engine inlet 74. The core engine inlet is limited by air splitter 705 and a point 704 on the hub on the opposite side of air splitter 705. The spray's distribution at the core engine inlet is equal to the core engine inlet opening limited by air splitter 705 and point 704. Thereby will the liquid emanating from nozzle 54 enter core engine inlet 74. Further, nozzle 54 is oriented as to enable the liquid to penetrate in between the blades during fan rotation. FIG. 7a and FIG. 7b describes washing of the turbofan engine by the use of the engine's starter motor. Alternatively may other starting device be used such as a separate APU starter. Alternatively, washing may be conducted without rotating the engine shaft.

(26) FIG. 8 shows the use of the camera and the distance measuring device. Similar parts are shown with the same reference numbers as previous figures. A camera 55 has a viewing angle limited by lines 81. The camera will provide a view of the engine nose bullet enabling the operator to move the spray head to the appropriate position for washing. When the engine is cranked by its starter motor the camera view is used for monitoring the shaft rotation. The camera may then be attached to a computing device (not shown) with software for estimating the rotational speed. The rotational speed serves as an input parameter to the operator when to start liquid pumping. Having control of the rotational speed is essential for a good wash result. Further, the camera view allows viewing of the liquid distribution onto the fan as well as the penetration of liquid into the core engine.

(27) This view serves as an important input to the operator as he may adjust the positioning of the spray head or adjust the wash parameters as to better serve his objectives. To avoid that the camera lens is contaminated with air borne liquid, the lens is purged by an air stream supplied from a compressed air source (not shown). The distance measuring device comprise of a transmitter 56 emitting a beam 82 towards nose bullet 83 where it reflects and returns the reflected beam to receiver 57. The signal is fed to a computing unit (not shown) for computing the distance. The computing unit may be set with alarm levels as to provide, e.g. an acoustic alarm, if the distance to any object becomes critically short. The distance measuring device may be directed towards other objects than the nose bullet in the engine inlet as to provide information on measured distances. To avoid that the measuring device sensors are contaminated with air born liquid they are purged by an air stream supplied from a compressed air source (not shown).

(28) FIG. 9 shows the universal spray head which will service a large range of differently sized engines. Spray head 90 is shown in a perspective view where the arrow shows the direction of the air flow. Spray head 90 has a central body 91 with similar camera, distance measuring device and lamp as earlier described in spray head 33 in FIG. 5. Spray head 90 comprise of multiple ring shaped manifolds 92 each with different diameters. Rings 92 are arranged in symmetry around central axis 501. Rings 92 are all essentially in the same plane where the planes are essentially perpendicular to axis 501. The rings are arranged with a gap in between the rings as to allow air flow through the spray head. Each ring comprises of one or multiple nozzles 93 where the nozzle type, number of nozzles and the nozzles spacing is according to the wash service the ring will do. Nozzles may be used for washing of the fan, the core engine, the cowling, the bullet nose or similar service. In principal, the inner rings are used for washing of smaller engines while the outer rings are used for washing of larger engines. Further, one ring may de dedicated to washing of a specific engine type or a specific family of engines. The ring with the largest diameter, i.e. the outer ring, has a diameter less than the diameter of the inlet cowling of the smallest engines that the spray head will service. For example, the engines of the popular passenger carrying commercial airlines have an inlet cowling diameter varying in between 1.5 to 3 meters. The spray head to service those engines would then have an outer diameter less than 1.5 meter.

(29) For washing of an engine typically only one ring is in service. This is accomplished by having each ring 92 connected via a conduit to a distributor (not shown for clarity) on the spray head. The distributor comprise of individual valves for closing each conduit. Prior to set-up for washing the operator would activate the ring to be in use by opening the corresponding valve. All other valves would then be closed.

(30) Although spray head 90 is universal in the meaning that it may service a wide range of aircraft types and engine types it is practical to have multiple spray heads that are exchangeable. This may be reasoned by different requirements set by the aircraft's instructions or other instructions. Another reason could be a separate spray head for meeting military aircraft requirements. There may be additional reasons. To accomplish changing of the spray heads the spray head is mounted on the robotic arm with a coupling enabling an easy exchange.

(31) The invention as here disclosed provides means for reducing the time for washing as well as reducing labour requirement. FIG. 10 shows the arrangement for engine washing that is both less time consuming and less labour intensive compared to prior art. Similar parts are shown with the same reference numbers as previous figures. The process described herein would typically require only one operator for conducting the wash. A wash unit 31 supplies wash liquid via conduit 35 to a spray head held by robotic arm 34. During washing the operator controls the process from control panel 113. Controlling includes viewing the spray head camera image from monitor 112. The waste wash liquid emanating from the engine is collected by collecting device 114 at the rear of the engine. The collected waste liquid enters a tank (not shown) in unit 116 via conduit 115. Unit 116 may be equipped with wheels for mobility. A suitable collecting device is described in the international application PCT/SE 2004/000922, wherein the content of said application hereby is included herein by reference. The waste liquid is pumped via conduit 118 to a tank in wash unit 31 where the released fouling material is separated from the liquid by an appropriate waste water treatment process. The treated water will then be used for washing of next engine or is alternatively dumped into a sewer. While the waste water is being treated the operator may move his vehicle 32 and other equipment to the next engine for set-up for the next wash.

(32) Although specific embodiments have been shown and described herein for purposes of illustration and exemplification, it is understood by those of ordinary skill in the art that the specific embodiments shown and described may be substituted for a wide variety of alternative and/or equivalent implementations without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Consequently, the present invention is defined by the wordings of the appended claims and equivalents thereof.

(33) While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.