GB2074048A

GB2074048A - Spray cleaning apparatus

Info

Publication number: GB2074048A
Application number: GB8006892A
Authority: GB
Original assignee: UK Secretary of State for Defence
Current assignee: UK Secretary of State for Defence
Priority date: 1980-02-29
Filing date: 1980-02-29
Publication date: 1981-10-28
Also published as: GB2074048B

Abstract

Apparatus for removing corrosive and/or abrasive matter from an aircraft engine in situ after landing comprises a one-man manoeuvrable trolley 10 carrying a reservoir 11 for demineralized water, a gas bottle 12 for pressurizing the reservoir, and a lance 15 for delivering the water to an engine intake while the engine is running, the lance carrying a nozzle 20 in the form of a cylinder entered tangentially by the lance and having an exit port centrally in an end wall thereof, the diameter of the port being of the order of the bore of the lance. The apparatus may also include a further reservoir 13 and a nozzle 26 for spraying a protective fluid (eg WD 40) into the engine after the washing. <IMAGE>

Description

SPECIFICATION Aircraft engine desaliniser The present invention relates to cleaning apparatus, and is particularly concerned with apparatus for cleaning corrosive and abrasive matter and substances from gas turbine engines, especially those of craft such as aircraft liable in certain operations to ingest such matters and substances.

It is, or course, desirable that adequate cleaning of a machine such as a gas turbine engine be effected without dismantling the machine more often than may be required for normal wear servicing, as this is costly both intrinsically and also due to the machine being out of service, Adequate cleaning of a gas turbine engine can be effected with the assistance of the engine if a quantity of sluicing fluid is introduced to the engine intake across the whole area thereof while the engine is running. The quantity of fluid introduced in any instant must be large if cleaning is to be thorough and the offending material is to be removed from rather than relocated within the engine, and to ensure that the cleaning fluid is substantially all ejected by the engine even if it has dowsed the engine ignitor.It is also particularly desirable for the cleaning apparatus to be mobile, to be one-man operated and to carry its own power source.

Gas turbine engine cleaning apparatus hitherto known has not been mobile and has not been capable of mobility because of the quantity of power it has been thought necessary to provide in order to introduce the required quantity of fluid into the engine within the required time.

The present invention provides cleaning apparatus wherewith a required quantity of cleaning fluid can be introduced to a gas turbine engine using a power source capable of mobility and one man manoeuvring and control.

According to the present invention cleaning apparatus comprises: a reservoirforcarrying cleaning liquid pressurized gas means for pressurising the cleaning liquid, and a nozzle for spraying the liquid, the nozzle comprising a cylinder having an entry tube disposed tangentially with respect thereto and an exit port centrally in an end wall thereof whereby in operation of the apparatus liquid under pressure from the reservoir enters the nozzle via the entry tube and swirls within the cylinder before leaving the exit port in a divergent spray.

The exit port is preferably unique and circular with a diameter of the order of the bore of the entry tube, so that there is no restriction in the nozzle to the flow of the fluid. The entry tube may, if desired, be directed slightly axially of the cylinder, preferably toward the exit port end thereof. The exit port is advantageously belled out at the lip thereof.

The cleaning liquid may be water, and is preferably demineralized water.

According to a preferred feature of the invention the apparatus also comprises a trolley carrying the reservoir and is manoeuvrable under the effort of one person. The pressurized gas means may be a container of pressurized gas and is preferably carried on the trolley and connected to the cleaning liquid reservoir via a control cock. The nozzle is advantageously mounted on a lance, preferably formed by metal tubing for conveying the liquid, whereby the nozzle may be held in front of a gas turbine engine intake without the person holding it being so situated.

It will be appreciated that after sluicing out a machine such as a gas turbine engine with a cleaning liquid such as water it may be highly desirable to effect protection of the machine from corrosion etc due to exposure of bare metal and the presence of a residuum of cleaning fluid. It is in fact known to spray a light oil compound into a gas turbine engine for this purpose as the engine is being run down.

According to another feature of the present invention the apparatus may include a reservoir of protective liquid and a nozzle for the injection thereof into a machine. As the quantity of protective liquid required is likely to be considerably less than that of the cleaning fluid, and also the liquid may preferably be dispersed in fine droplet or mist form, the nozzle for the injection thereof is preferably of a traditional restrictive type. The protective liquid supply facility is advantageously arranged for operation under gas pressure, and may, particularly if mounted on the above-mentioned trolley, employ the same pressurized gas supply means.

A typical protective liquid for use in aircraft gas turbine engines is the de-watering aid marketed by General Motors under the trade name "Rocket WD40"and known in the trade as WD40.

Certain machines, including certain gas turbine engines, may have means whereby cleaning, followed perhaps by protective, fluid can be directly inserted. Apparatus in accordance with the invention may have an additional delivery tube for direct insertion of fluid. On certain gas turbine engines an entry port is available in the region of the compressor stage and the additional delivery tube may have a connector for attachment to this entry port.

The apparatus may include metering means for delivering predetermined quantities of the fluids in a given time.

Atypical cleaning operation will now be outlined with respect to an aircraft gas turbine engine following low flight over desert or sea water for example and using apparatus in accordance with the invention comprising pressurized demineralized water and protective oil reservoirs with the above described nozzles and additional delivery tube.

While the engine is idling a gallon of the water is injected into the compressor stage over a period of 30 seconds followed by 3-4 gallons of the water into the intake over about 30 seconds. Then, while the engine is running down, a pint of protective liquid is injected into the compressor stage over about 15 seconds followed by a pint of protective liquid sprayed into the intake over 10-20 seconds.

Aircraft gas turbine engine cleaning and protective apparatus in accordance with the invention will now be described by way of example with reference to the accompanying drawings, of which: Figure lisa schematic diagram of a cleansing trolley, and Figure 2 is a view in perspective of a cleaning liquid nozzle.

The apparatus illustrated in Figure 1 comprises a one-man manoeuvrable trolley 10 carrying a demineralized water reservoir 11, a pressurized gas bottle 12 and a protective oil reservoir 13. The bottle 12 is connected via a three-way cock 14 with either of the reservoirs 11 and 12.

An outlet to the water reservoir 11 supplies a water spray lance 15 via a three-way control cock 16 and a length of flexible hose 17. The lance 15 has a handle 18, a flow control valve 19 and a nozzle 20.

An outlet to the protective oil reservoir 13 supplies an oil spray lance 21 via a three-way control cock 22 and a length of flexible hose 23. The lance 21 has a handle 24, a flow control valve 25 and a nozzle 26.

The control cocks 16 and 22 supply, via non-return valves 27 and 28 associated one with each cock respectively, an additional delivery tube 29 carrying a connector 30.

The reservoirs 11 and 13 have pressure relief valves 31 and 32 respectively.

The cleaning water nozzle 20 is more clearly illustrated in Figure 2. It comprises a cylinder 41 closed at both ends, one end being pierced centrally by an exit port 32 which is slightly belled out. The lance 15 provides the entry tube to the cylinder 41 and does so in tangential manner so that liquid entering thereby is forced to swirl around the cylinder and is flung out centrifugally as it leaves the exit port 42. The diameter of the port 42 is slightly larger than the bore of the lance 15.

The protective liquid nozzle 26 is, as shown, forked wih two orifices.

For operation of the apparatus with an aircraft gas turbine engine of the type having a high pressure compressor stage tapping receptive to the connector 30 the cylinder 11 is charged with demineralized water, the cylinder 13 with WD40 (trade name) protective oil, and the cylinder 12 with air to a suitable pressure. The trolley is manoeuvred to a position just to the side of the engine intake and the connector 30 plugged in.

With the engine idling the cock 14 is adjusted to allow gas from the container 12 to pressurize the water in the reservoir 11. With the cock 22 off the cock 16 is opened for 30 seconds so as to permit a gallon of water to be pumped into the engine. With the lance held so that the nozzle 20 is central to and ahead of the engine intake the cock 16 is adjusted and the control 19 operated to inject 3-4 gallons of the water into the engine via the intake. The cock 16 is then closed and the lance 15 stowed.

The cock 14 is then adjusted so that the contents of the reservoir 13 are pressurized. A short time after closing the HP cock as part of the engine shut down procedure the cock 22 is adjusted to permit a pint of protective fluid to enter the compressor stage via the connector 30 over 15 seconds. The cock 22 is then adjusted to cut off protective fluid flow to the tube 29 and to direct it to the lance 21 whence, by cock 25, a pint of protective fluid is sprayed into the engine intake over 10-20 seconds.

In a typical example of the above described apparatus the reservoir 11 has a capacity often gallons, and the reservoir 13 of 2 gallons.The lance 15 has a bore of 3/8 inch, the cylinder 31 of the nozzle 20 a diameter of 3 inches and a length of 21/2 inches, and the exit 2 orifice a diameter of 5/8 inch.

The cocks 16,22, 19 and 24 are arranged, for a working pressure of 40 psi, to pass the required quantities of fluid in the given times.

In an alternative embodiment of the invention metering devices are included which determine both the quantity and the period of delivery.

Claims

1. Cleaning apparatus comprising a reservoirfor carrying cleaning liquid, pressurized gas means for pressurizing the cleaning liquid, and a nozzle for spraying the liquid, the nozzle comprising a cylinder having an entry tube disposed tangentially with respect thereto and an exit port centrally in an end wall thereof, whereby in operation of the apparatus liquid under pressure from the reservoir enters the nozzle via the entry tube and swirls within the cylinder before leaving the exit port in a divergent spray.

2. Cleaning apparatus according to claim 1 in which the exit port is unique and circular with a diameter of the order of the bore of the entry tube, so that there is no restriction in the nozzle to the flow of the fluid.

3. Cleaning apparatus according to claim 1 or claim 2 in which the entry tube is located axially along the cylinder towards the end remote from the exit port.

4. Cleaning apparatus according to claim 1, claim 2 or claim 3 in which the entry tube is displaced slightly axially of the cylinder toward the exit port end thereof.

5. Cleaning apparatus according to claim 1, claim 2, claim 3 or claim 4 in which the exit port is belled out towards the lip thereof.

6. Cleaning apparatus according to any previous claim, further comprising a trolley carrying the reservoir and manoeuvrable under the effort of one person.

7. Cleaning apparatus according to claim 6 in which the pressurized gas means is a container of pressurized gas carried on the trolley and connected to the cleaning liquid reservoir via a control cock.

8. Cleaning apparatus according to any previous claims in which the nozzle is mounted on a lance formed by metal tubing for conveying the liquid.

9. Cleaning apparatus according to any previous claim including a reservoir of protective liquid and a nozzle for the injection thereof into a machine.

10. Cleaning apparatus according to claim 6 including a reservoir of protective liquid carried on the trolley and arranged for operation under pressurized gas means.

11. Cleaning apparatus according to claim 10 in which the pressurized gas means is a container of pressurized gas carried on the trolley and selectively connected to the cleaning liquid and protective liquid reservoirs via a control cock.

12. Cleaning apparatus substantially as herein described with reference to the accompanying drawings.