Surface Conditioning Of Railway Tracks Or Wheels

Abstract

A surface conditioning device for railway track rails and/or railway vehicle wheels includes a DC power supply, a supply of gas, a plasma delivery head connected to receive DC power from the power supply and gas from the gas supply, and an igniter for igniting the gas in the plasma delivery head. In use, plasma is generated within the delivery head by ignition of the gas in the delivery head. Plasma with gas is blown from the delivery head onto a railway track rail and/or railway vehicle wheel, thereby conditioning the rail and/or wheel.

Claims

1-21. (canceled)

22. A surface conditioning device for railway track rails and/or railway vehicle wheels, the surface conditioning device comprising: a DC power supply; a supply of gas; a plasma delivery head connected to receive DC power from said power supply and gas from said gas supply; and an igniter for igniting said gas in said plasma delivery head; wherein plasma is generated within said delivery head by ignition of said gas in said delivery head, and plasma with gas is blown from the delivery head onto a railway track rail and/or railway vehicle wheel, thereby conditioning said rail and/or wheel.

23. The surface conditioning device of claim 22, wherein said gas comprises nitrogen.

24. The surface conditioning device of claim 22, wherein said gas comprises a mixture of gases.

25. The surface conditioning device of claim 24, wherein said mixture of gases comprise a mixture of hydrogen and nitrogen or a mixture of nitrogen and oxygen.

26. The surface conditioning device of claim 22, wherein said gas includes argon as an initial gas to initiate ignition and another gas or mixture of gases to replace the argon and generate the plasma.

27. The surface conditioning device of claim 22, wherein the power supply is a dual-voltage inverter power supply.

28. The surface conditioning device of claim 22, further comprising a heat exchange system that is operative to reduce a temperature at or in the vicinity of the plasma delivery head.

29. The surface conditioning device of claim 22, further comprising an anti-freeze system that is operative to circulate an anti-freeze medium at or in the vicinity of the plasma delivery head.

30. The surface conditioning device of claim 22, further comprising a cooling system that is operative to circulate coolant at or in the vicinity of the plasma delivery head.

31. The surface conditioning device of claim 22, wherein the plasma delivery head operates at a temperature in the range 300° C.-1500° C.

32. The surface conditioning device of claim 22, further comprising a Raman spectrometer that is operative to sense the presence or absence of contaminants on a railway track rail and/or railway vehicle wheel, without contact with the rail or wheel.

33. The surface conditioning device of claim 32, wherein the Raman spectrometer is operative to analyse a composition of said contaminants and indicate a level of contamination.

34. The surface conditioning device of claim 32, further comprising an optimizer that is operative to optimize energy requirement for conditioning of the rail or wheel, in response to an output of the Raman spectrometer.

35. The surface conditioning device of claim 32, further comprising a Raman spectrometer that is operative to sense a level of achievement of conditioning of a rail or wheel.

36. The surface conditioning device of claim 22, comprising a plurality of said plasma delivery heads spaced along a direction of travel along a rail, such that said delivery heads successively condition the rail, one after another.

37. The surface conditioning device of claim 22, including an operating interface whereby a user can control operation of the surface conditioning device.

38. A method of conditioning a railway track rail and/or railway vehicle wheel, the method comprising operating the surface conditioning device of claim 1 to condition a rail or wheel.

39. The method of claim 38, wherein the surface conditioning device is operated on a railway vehicle as it travels along a railway track rail.

40. The method of claim 38, wherein the surface conditioning device is operated as the railway vehicle makes multiple passes along the railway track rail.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which:

[0039] FIG. 1 shows one embodiment of surface conditioning device as a schematic diagram, showing the inter-relationship between a nitrogen generator, DC power supply and a chilling system to deliver coolant, a nitrogen supply and a high voltage supply through outputs A, B and C;

[0040] FIG. 2 shows one embodiment of plasma delivery head in section view, showing the inputs A, B and C from FIG. 1, delivering the coolant, nitrogen supply and high voltage supply to the plasma delivery head;

[0041] FIG. 3 shows one embodiment of a surface conditioning device when mounted to a railway vehicle, showing a pair of plasma delivery heads between wheels of said railway vehicle;

[0042] FIG. 4 shows a further embodiment of surface conditioning device when mounted to a manual track treatment vehicle, showing a remote location of nitrogen generator, ignition box and DC Power supply operatively connected to a plasma delivery head;

[0043] FIG. 5 shows a further embodiment of surface conditioning device when configured as a railway vehicle specific for rail track treatment, showing possible locations for mounting plasma delivery heads;

[0044] FIG. 6 shows a further embodiment of surface conditioning device when mounted to a locomotive, showing possible locations for mounting plasma delivery heads to railway vehicles for carrying passengers or freight;

[0045] FIG. 7 shows a pair of plasma delivery heads of FIG. 2 in isometric view, and the relationship of the plasma delivery heads to wheels of a railway vehicle when configured to surface condition rails;

[0046] FIG. 8 shows a side view of one of the plasma delivery heads of FIG. 7, and the relationship of the plasma delivery head to the wheel when configured to surface condition the rail;

[0047] FIG. 9 shows a side view of a plasma delivery head of FIG. 2, and the relationship of the plasma delivery head to the wheel of a railway vehicle when configured to treat the wheel;

[0048] FIG. 10 shows a pair of plasma delivery heads of FIG. 2 in isometric view, when configured to treat respective wheels; and

[0049] FIGS. 11 to 15 show a series of graphs that show the impact that a surface conditioning device has on the surface condition of a rail, showing change in condition with successive passes.

[0050] In the figures, like references denote like or corresponding parts.

DETAILED DESCRIPTION

[0051] It is to be understood that the various features that are described in the following and/or illustrated in the drawings are preferred but not essential. Combinations of features described and/or illustrated are not considered to be the only possible combinations. Unless stated to the contrary, individual features may be omitted, varied or combined in different combinations, where practical.

[0052] FIG. 1 shows one embodiment of surface conditioning device 1 showing an AC three-phase generator 24 operatively connected to a number of components that make up the surface conditioning device 1, to provide a source of power to these components. The generator 24 input may be from a rechargeable battery, or it may use regenerative power. The components that may be provided with power from the generator 24 include a chilling system 10, heat exchanger 11, nitrogen generator 4, DC power supply 3, an ignition box 5 and a gas box 25. The surface conditioning device 1 may be manually controlled by an operator through an operating interface 14. One or more sensors, not shown, may be in communication with operating interface 14 to operate the surface conditioning device 1 in response to one or more conditions. For an example, the surface conditioning device 1 may be configured to condition the surface of a rail 2 and/or wheel 7 when a railway vehicle 8 (e.g. in FIG. 3) begins braking. In a further example, the surface conditioning device 1 may respond to environmental conditions, such as the detection of moisture in the vicinity of the rail 2, or in response to a drop in temperature of the environment surrounding the rail 2. This allows surface conditioning to occur in direct response to a specific condition being detected, by the railway vehicle 8 that has detected the condition. It also allows railway vehicles 8 that pass along the rails 2 to condition these rails 2 as they travel. The surface conditioning device 1 may be configured to sense and analyse the nature and intensity of the contaminant. For an example, if the quantity of contaminant is less than say expected, the plasma energy supplied may be dialled down accordingly, or vice versa for heavy contamination.

[0053] The DC power supply 3 is configured to generate a direct current from an AC supply received from the generator 24, and to provide a high voltage supply 12 of DC current to the ignition box 5. The ignition box 5 provides the circuitry to generate a spark at an igniter 6 within the plasma delivery head 13, shown in FIG. 2. Plasma is generated within the plasma delivery head 13, by striking an electric arc between an anode 20 and a cathode 21, whereby a spark is created at a tip of the igniter 6. A plasma jet then emerges from plasma delivery head 13, and onto the rail 2 or wheel 7.

[0054] The surface conditioning device 1 incorporates the nitrogen generator 4. This nitrogen generator 4 comprises an air compressor 16, that feeds compressed air into a membrane nitrogen generator 15. This membrane nitrogen generator 15 separates the compressed air, and passes a supply of nitrogen from this compressed air into a condensate treatment 18. The condensate treatment 18 is configured to condense the nitrogen and supply a feed of this into a pressure vessel 17. The pressure vessel 17 pressurises the nitrogen to generate a nitrogen supply 9 that is suitable for passing by tube to the gas box 25.

[0055] The gas box 25 may house one or more of the following components: primary and secondary gas mass flow controllers, control PLC with industry standard Ethernet interface, control valves and switching for sequencing and safe operation of the system, E-stop circuit. Signals from these components can all be linked into a control system through the operating interface 14. The gas box 25 may also comprise interlocks to inhibit system operation unless the following are within preset limits: coolant pressure, temperature and flow; primary, secondary and/or carrier gas pressure and flow, a fault indication strobe, control connections for DC power supply 3, or DIPS power supply.

[0056] FIG. 2 shows the plasma delivery head 13, that may be referred to as a plasma gun or pistol. The igniter 6, within the plasma delivery head 13, is configured to ignite the nitrogen supply 9 by generating a spark within the plasma delivery head 13. A single spark from the igniter 6 excites and ignites the nitrogen supply 9, and by adding such heat energy the nitrogen supply 9 loses some of its electrons, becoming ionised and converted into plasma. The generated plasma is carried by the nitrogen supply 9, and gains energy from the high voltage supply 12 supplied by the DC power supply 3. More plasma is generated from the nitrogen supply 9 by the generated plasma and the high voltage supply 12 exciting and ionising the gas at atmospheric pressure. A gas vortex is generated by the nitrogen supply 9 and this vortex continues to become excited by the high voltage supply 12 driving the plasma through a nozzle 22 and out of the plasma delivery head 13 to be blown onto the surface to be conditioned. The nozzle 22 helps to contain and concentrate the plasma. This configuration enables a high velocity blast of plasma to be delivered to the rail or wheel to be conditioned. This facilitates thermal ablation of contaminant on the rail or wheel.

[0057] It is to be noted that devices embodying the invention preferably employ a non-transferred configuration, without any additional current between the plasma delivery head 13 and rail surface or wheel to be conditioned.

[0058] In an alternative embodiment a first gas is introduced into the plasma delivery head 13, prior to the nitrogen supply 9. This first gas is readily ignited. One example of suitable first gas is argon. Once the argon has been ignited at the igniter 6 by a spark, and plasma begins to form, the current and voltage can be increased and then the nitrogen supply 9 is introduced into the plasma delivery head 13, to achieve stable plasma. The first gas, not shown, is configured to pass along the same supply line as the nitrogen supply 9. The moment at which the supply of gas switches from argon to nitrogen is automatically determined by control circuitry, and is timed to ensure optimum levels of plasma are generated.

[0059] The igniter 6 may only be activated for a few seconds, sufficient to generate a spark and ignite the nitrogen supply 9, or other gas supply suitable for igniting. The nitrogen supply 9 may alternatively comprise another gas that can be any monoatomic or diatomic, or a gas mixture. For an example, the gas mixture may comprise water molecules added to the gas.

[0060] The surface conditioning device 1 may incorporate a chilling system 10, to ensure that the plasma delivery head 13 is not allowed to exceed a predetermined temperature level that could cause risk to the surroundings, and could also cause damage to the plasma head as components of the head could melt. This chilling system 10 is configured to help cope with the high heat loads that the plasma delivery head 13 experiences. The chilling system 10 may comprise a coolant reservoir or coolant generator, to supply coolant 19 to the plasma delivery head 13. The coolant 19 may comprise water, oil or similar fluid for drawing heat energy from the plasma delivery head 13.

[0061] The chilling system 10 is shown operatively connected to the heat exchanger 11. The heat exchanger generates the supply of coolant 19 that is then fed to the plasma delivery head 13.

[0062] FIG. 2 shows one embodiment of plasma delivery head 13 that is operatively connected to FIG. 1 through the three inputs A, B and C. These inputs comprise nitrogen supply 9 from the nitrogen generator 4, high voltage supply 12 from the DC power supply 3, and coolant 19 from the chilling system 10 to the plasma delivery head 13. The plasma delivery head may incorporate a delivery tube that comprises a hollow, elongate tube of electrically conductive material, for example copper, configured to supply plasma to a surface. The plasma delivery head 13 may incorporate a nozzle 22 for delivering plasma to a surface. The nozzle 22 may be a separate element affixed to a plasma output of the plasma delivery head 13. Alternatively, the nozzle 22 may be formed as part of the plasma delivery head 13, and may be shaped at one end to form an effective nozzle 22, through its geometry, such as venturi, divergent, convergent or asymmetrical. The nozzle 22 helps to focus the plasma onto the portion of rail 2 or wheel 7 that is to be treated. This portion of surface of rail 2 or wheel 7 is likely to be within the range of 5 mm to 20 mm that is to be conditioned at any one time. Mounting the end bore of the nozzle 22 at a distance of between 25 mm and 75 mm to the surface to be conditioned provides sufficient coverage to this portion of rail 2. The nozzle 22 may comprise metal, which would therefore reduce EMC emissions. The nozzle 22 and/or plasma delivery head 13 may incorporate some form of shielding, not shown, for shielding the surroundings. The shielding may shield against UV light and may also create an aerodynamic effect to assist delivery of the plasma onto the railway track rail 2.

[0063] The distance between the plasma delivery head 13 and the rail or wheel to be conditioned may be in the range 10 mm to 75 mm. A distance in the range 10 mm to 25 mm may facilitate improved conditioning.

[0064] The surface conditioning device 1 may incorporate at least one mounting means, not shown, for mounting the component parts that make up the surface conditioning device 1 to a railway vehicle 8. This mounting means may be permanent or releasable. Permanent means might include welding, or securing through a plurality of bolts or rivets to the railway vehicle 8.

[0065] The surface conditioning device 1 may incorporate at least one sensor, not shown, for sensing a condition and activating the surface conditioning device 1 in response to a change or a predetermined value for that condition. The sensor may comprise a Raman spectrometer. The sensor may comprise a thermal sensor, mechanical sensor and/or motion sensor, or any combination of these. Thermal sensors detect a change in temperature within a surrounding environment, which may affect the condition of rails 2 and require surface conditioning to be activated to ensure that the surface of the rails 2 remains unaffected by the change. Thermal sensors may comprise thermometers or thermostats. The sensor may comprise a motion sensor or speed sensor, such as an accelerometer or speedometer, for detecting retardation or braking of a railway vehicle 8, and activating the surface conditioning device 1 during braking of the railway vehicle 8. The sensor may comprise a frictional sensor, visual track condition sensor or slippage sensor. This should help to prevent slip between the rail 2 and wheel 7 interface. The sensor may also comprise a moisture sensor for detecting dew within the immediate environment surrounding a rail 2.

[0066] FIG. 3 shows one embodiment of surface conditioning device 1 when mounted between the wheels 7 of a typical railway vehicle 8. The wheels 7 run along a rail 2 or rail head, and the surface conditioning device 1 is mounted such that it conditions the surface of the rail 2 as the railway vehicle 8 passes along. The surface conditioning device 1 comprises at least one DC power supply 3, at least one nitrogen generator 4 and at least one plasma delivery head 13. The DC power supply 3 may be a Dual-voltage Inverter Power Supply (DIPS). Shown in FIG. 3 is a pair of plasma delivery heads 13 mounted adjacent to one another. The surface conditioning device 1 may comprise a modular arrangement with multiple plasma delivery heads 13. In such a modular arrangement the plasma delivery heads 13 may be mounted at various locations throughout the railway vehicle 8 to enable the surface conditioning device 1 to condition a surface of the rails 2 and/or to condition a surface of the wheels 7 of the railway vehicle 8 at any one time, intermittently or on an ongoing basis. Each plasma delivery head 13 may be controlled independently or all of the plasma delivery heads 13 may be controlled to operate at the same time, through the operating interface 14, not shown, where the operating interface 14 is within a driver’s cab of the railway vehicle 8. The operating interface 14 may be mounted at a suitable location within the railway vehicle 8 such that a display of can be read and responded to by a rail vehicle operator.

[0067] Each plasma delivery head 13 is operatively connected to the nitrogen supply 9, the high voltage supply 12, and the supply of coolant 19 for generating plasma and delivering this plasma onto the rail 2 and/or wheel 7. The plasma delivery head 13 is mounted to the railway vehicle 8 such that the end is at a suitable distance from the surface of the rail 2 for conditioning this surface. Mounting the plasma delivery heads 13 between wheels 7 of the railway vehicle 8 ensures that the plasma delivery heads 13 are shielded from the harsher conditions experienced in front of the leading wheel 7 of the railway vehicle 8. The railway vehicle 8 may be a locomotive or carriage of any railway vehicle 8 for transporting passengers or freight, and the surface conditioning means 1 may therefore be carried out during the usual passage of the railway vehicle 8 along the rails 2.

[0068] FIG. 4 shows the surface conditioning device 1 forming part of a specialist railway vehicle 8 or manual track treatment vehicle. This railway vehicle 8 has the sole purpose of travelling along rails 2, providing means to condition these rails 2. This track treatment vehicle is provided with carriages that carry the components of the surface conditioning device 1. In the configuration shown, the second carriage carries the nitrogen generator 4, and this carriage is operatively connected to the gas box 25. The chilling system 10 and DC power supply 3 are housed within the first carriage. This first carriage is operatively connected to the plasma delivery head 13 through a nitrogen supply 9, high voltage supply 12 and a supply of coolant 19, not shown. The plasma delivery head 13 is mounted to the carriage of the railway vehicle 8 such that a plasma output or nozzle 22, not shown, has one end in close communication with the surface of the rail 2 that is to be conditioned.

[0069] FIG. 5 shows a further embodiment of railway vehicle 8 or track treatment vehicle with a pair of plasma delivery heads 13 mounted at intervals along the undercarriage of the railway vehicle 8. This track treatment vehicle conditions the rails 2 when there are no freight or passenger trains needing to use the line. FIG. 6 shows a surface conditioning device 1 when installed within a typical railway vehicle 8 such as a locomotive, that provides the advantage of conditioning the rails 2 during the usual passage of said railway vehicle 8 along the line. Shown in this modular arrangement are two plasma delivery heads 13 mounted to the undercarriage of the railway vehicle 8, and likely a further pair of plasma delivery heads 13 in a similar location on the other side of the railway vehicle 8. This modular arrangement allows for a number of plasma delivery heads 13 to be conditioning the rails at various locations at any one time, to ensure thorough coverage and conditioning of the surfaces of the railway track rails 2. Each portion of rail 2 is therefore subjected to multiple passes of surface conditioning with just one pass of the railway vehicle 8.

[0070] For each of FIGS. 3 to 6, the plasma delivery heads 13 may additionally or alternatively be mounted to condition the surfaces of the wheels 7 of the railway vehicles 8, as shown for example in FIGS. 9 and 10. In these embodiments the plasma delivery heads 13 would be mounted such that the output or nozzle is directed towards, yet at a suitable distance from, the surface of each wheel 7 of the railway vehicle 8 that requires conditioning.

[0071] Some of the components that make up the surface conditioning device 1 may be located at a fair distance away from the plasma delivery head 13 within any of these railway vehicles 8. This allows any bulky or heavy components of the surface conditioning system 1 to be located in a more suitable position within the railway vehicle 8. The sensitive elements that make up the surface conditioning device 1 may be provided with a buffer or vibration damping element, not shown, to prevent those elements from being exposed to vibrations and shocks during operation.

[0072] A surface monitoring device 29 may be operatively connected to an optimiser 31 as shown, for feeding instructions back to the surface conditioning device 1, to ensure that a required treatment of the surface is optimised. The optimiser 31 may send instructions through a control device, not shown, to activate further surface conditioning processes

[0073] FIGS. 7 and 8 show an isometric view and side view of one possible arrangement of plasma delivery head 13 in relation to wheel 7, when the plasma delivery head 13 is configured to condition the surface of the rail 2. Plasma delivery heads 13 are mounted on each side of the railway vehicle 8, and at a suitable spacing from the wheels 7 and axle 23.

[0074] FIGS. 9 and 10 show an isometric view and side view of one possible arrangement of plasma delivery heads 13 when they are configured to surface condition the wheel 7 of the railway vehicle 8, rather than rail 2.

[0075] FIGS. 11, 12, 13, 14 and 15 show graphs to illustrate contamination levels on a surface, and the impact of the surface conditioning device 1 when it has passed over a surface. The main peaks on the graphs represent an intensity of contamination and the frequencies represent the compound types. The intensity value is dimensionless as it relates directly to a RAMAN spectrometer algorithm. In FIG. 11 there are high intensities of Cellulose, Cellulose Acetate & Tryosine present. These key compounds are indicators of the presence of leaf layer contamination. The plasma has been tuned to target these compounds and remove them.

[0076] This can be seen with the progressive passing of the plasma over the same surface. Each graph shows how the intensity is reduced with each pass of plasma until there is no longer any significant leaf layer remaining, the change in surface condition of the surface following passes of the surface conditioning device 1. FIG. 11 shows the results obtained through RAMAN spectroscopy before passing over the surface conditioning device 1 in grey, and the results of surface condition after conditioning, shown in darker grey. This graph represents an experiment conducted at a treatment height of 15 mm between plasma delivery head 13 and rail 2.

[0077] FIGS. 12, 13, 14 and 15 show a series of graphs, with each one in the series showing the results of a further pass of the surface conditioning device 1 over the rail 2, at a treatment height of 20 mm. FIG. 12 shows the change in results from this first condition, shown by the lighter grey line, to the results following a first pass of the surface conditioning device 1. The main peak appears to split, which represents two different components of contamination. FIG. 13 shows the results of a second pass, shown in dark grey, in relation to the results after the first pass, shown in light grey. The peaks have been greatly reduced in size. FIG. 14 shows the condition of the same surface after yet a further pass of the surface conditioning device 1, where results after the second pass are now shown in light grey, and results after this third pass are shown in dark grey. The peaks have evened out some more. FIG. 15 shows the results of a further, or fourth pass, of the surface conditioning device 1. The results of the third pass are shown here in light grey with the results of the fourth pass in dark grey. The peaks have now been virtually eradicated, showing that the surface condition has been optimised after the fourth successive pass.

[0078] Where a Raman spectrometer is provided, it may be configured to scan frequencies of particular interest to a driver or other operator on the rail network. Those frequencies may correspond to the components of anticipated contaminants on the rails. For example, frequencies having a wavenumber selected from the group comprising 640, 1430, 1480, 1260, 1213, 1240, 1580, 2000 cm.sup.1. Contaminants of potential interest may include Cellulose, Cellulose Acetate and Tyrosine.

[0079] By limiting the Raman spectroscopic analysis to frequencies of particular interest, corresponding to anticipated contaminants of interest, scanning can be carried out much more quickly than if broadband frequencies are scanned. This leads to critical data being available to a driver or other operative much more quickly, thereby improving safety on the railway network.

[0080] Results from Raman spectrometry may be displayed to a driver in a driver’s cab or to a person responsible for maintaining the condition of rails. The display may indicate detailed data representing the condition of monitored rails. Additionally or alternatively, it may simply indicate if the condition of a monitored rail is either GOOD or BAD — e.g. indicated by a tick or a cross. This enables a driver or track manager to respond quickly to either change speed or request track conditioning, without having to spend time analysing more detailed data.

[0081] Contaminants can be referred to as a third layer, between first and second layers, which are respectively the rail 2 and the wheel 7.

[0082] In this specification, the verb “comprise” has its normal dictionary meaning, to denote non-exclusive inclusion. That is, use of the word “comprise” (or any of its derivatives) to include one feature or more, does not exclude the possibility of also including further features. The word “preferable” (or any of its derivatives) indicates one feature or more that is preferred but not essential.

[0083] All or any of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all or any of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0084] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0085] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.