EP1876296B1

EP1876296B1 - Method and device for removing ferrous material from a railway line

Info

Publication number: EP1876296B1
Application number: EP20070111925
Authority: EP
Inventors: Jacob Johan Schildmeijer
Original assignee: Koninklijke BAM Groep NV
Current assignee: Koninklijke BAM Groep NV
Priority date: 2006-07-06
Filing date: 2007-07-06
Publication date: 2013-04-10
Anticipated expiration: 2027-07-06
Also published as: NL2000129C2; EP1876296A3; EP1876296A2

Description

The invention relates to the maintenance of railway lines. In particular, in this case, it relates to both railway lines which are founded on a concrete slab and railway lines which are founded in a ballast bed. In the case of such railway lines, the problem occurs that pollution, such as iron particles which are released during grinding of the rails, ends up on the foundation and may lead to problems. The iron particles which end up on a concrete slab, may swirl up when a train passes and end up on the rails. This problem occurs to a lesser degree with railway lines which are founded in a ballast bed from pebbles and the like. However, with such a traditional foundation, pollution may nevertheless result from the fact that, due to the use of water and abrasive, relatively large lumps of abraded iron material can be formed which may end up on the ballast bed. Such lumps of abraded iron material usually have to be removed by hand, which is cumbersome and time-consuming. With such railway lines, the fine particles of the abraded iron material usually disappear into the gaps between the pebbles, which means that it is no longer free to move and remains trapped in the ballast bed.
Such iron particles result, first and foremost, from the fact that, after the rails have been laid, the rolling skin has to be removed therefrom. This rolling skin is created during the manufacturing process and can only be removed after the rails have been fixed in the correct position. The grinding procedure used for the removal of this rolling skin ensures that the running surfaces of the rails are of the appropriate quality, and also contributes to the correct spatial orientation of these running surfaces. Particularly with high-speed trains, this orientation is very important in order to ensure a smooth ride.
However, it is not only with newly laid rails that such a grinding procedure has to be carried out. After a certain amount of time which, depending on the intensity of the railway traffic, may for example be one or two years, the rails have to be ground again in order to remove the consequence of wear. During all these grinding activities, abraded iron material is formed which eventually ends up on the foundation of the railway line in the form of fine iron particles or as lumps of abraded iron material.
With railway lines which are founded on a concrete slab, there is the further problem that the top layer of the concrete material does not always set in the desired way. This may result in fine dust being present on the concrete slab which has a high quartz content. Quartz material is of great hardness, which may result in problems during use of the railway line.
The fact is that, during use, particulate material such as iron particles and quartz particles swirl up as a result of the suction generated by the passing railway traffic. The higher the speed of the railway traffic, the greater this suction becomes. Said problems therefore occur more often with railway lines which are used by high-speed trains. After such particulate material has swirled up, part of it ends up on the running surfaces of the rails. If then a subsequent train drives over the running surface covered in particulate material, the following problem occurs.
Due to the iron particles and the quartz particles being quite hard, they are not crushed between the wheels of the passing train and the running surfaces of the rails, but rather pressed into the running surfaces of the rails. This results in a significant deterioration in the quality and smoothness of the running surfaces, which is a problem, particularly with high-speed trains. For the latter, it is necessary that the running surfaces meet high requirements regarding quality and smoothness so as to be able to ensure an acceptable and comfortable ride.
EP-A-418.428 discloses a method for removing particulate material from a railway line which comprises a foundation and rails which are raised with respect to the foundation, which particulate material at least comprises magnetizable particles, such as abraded iron material or lumps of abraded iron material, which method comprises the steps of:

causing the particulate material to swirl up on account of a flow of fluid,
subjecting the swirled-up particulate material to a magnetic field,
causing the particulate material or lumps of abraded iron material to adhere to a magnet which is in a collecting position under the effect of the magnetic field,
removing the particulate material under the effect of this magnetic field,
providing the flow of fluid both on either side of the one rail and on either side of the other rail.

According to said prior art method, particulate material is swirled up from a railway bed by means of a rotating bristes which are contained in a housing. The swirled up particulate material is sucked from the housing. Any iron particles are attached by magnets which are arranged on the suction housing.
Once iron particulate material has been collected on the magnets, problems arise however concerning the further disposal thereof. De-energizing the magnets results in the particulate material dropping onto the railway bed again, apart from a fraction thereof which is sucked away.
The object of the invention is therefore to provide an improved method of the type described before, in such a way that any particulate material attracted by the magnets is reliably disposed. Said object is achieved by:

periodically displacing the magnet with particulate material or lumps of abraded iron material attached thereto from the collecting position to a container,
cancelling or reducing the magnetic field for depositing the particulate material or lumps of abraded iron material in a container,
returning the magnet to the collecting position,
restoring the magnetic field.

With the method according to the invention, the swirled-up particulate material, in particular iron particles, are subjected to a magnetic field. As a result thereof, these swirled-up particles can be removed in a reliable manner by this magnetic field, which is important, in particular with railway lines having a concrete foundation. As has already been mentioned, this concrete foundation contains a reinforcement made from iron material, which reinforcement is also affected by the magnetic field. The result of a reinforcement which has been magnetized in this way is that iron particles which may be present on the foundation are attracted by the reinforcement. However, as soon as such iron particles become attached to the foundation in such a manner, they are less easy to remove.
However, with the method according to the invention, the iron particles are prevented from being attracted by the reinforcement which has been magnetized on account of the magnetic field. After all, the iron particles are made to swirl up in such a manner that they are outside the influence of the reinforcement, which means that they can subsequently be removed by the magnetic field. The fact that the reinforcement is also magnetized on account of the magnetic field which removes the iron particles therefore then no longer plays a part in the removal of these iron particles.
Reference is made to the prior art, as is known from European patent 954,642 . This patent discloses a method for cleaning rails, in particular the grooves provided in rails for tram lines. According to this known method, a high-pressure jet of liquid is directed at the dirt. On account of the kinetic energy of this jet of liquid, the dirt is first sprayed off and subsequently directed to a collecting device by spraying. According to a variant of this method, a magnetic collecting device may be conducted over the railway line, prior to the spray nozzle being passed over it. This magnetic collecting device is designed to remove steel residues, such as chips and the like.
However, the problem with this known method is that when it is used on a railway line having a concrete foundation and an iron reinforcement, this reinforcement becomes magnetized and thus attracts iron particles. It is then no longer readily possible to remove these iron particles by means of a suction device, which is also evident from the fact that a high-pressure jet of liquid must be used with this known method.
Further reference is made to the prior art, such as is known from US patent 6,464,083 . This patent relates to the treatment of ferrous material, such as chips which result during the processing of metal in a factory environment. A recessed railway line is provided in the floor of the factory environment, the rails of which are situated in the recessed grooves. In these grooves, chips and the like may collect, which may pose problems for trains. The chips have to be removed from the grooves by means of a trolley having two spray nozzles which are located directly above the rails. The trolley also has magnets which are to collect the ferrous particles from the grooves. Such a device is not suitable for use with a railway line which comprises a foundation having raised rails, as the ferrous particles are not at the location of the rails but spread over a wide area inbetween and adjoining the rails.
Preferably, the method according to the invention also comprises the step of:

providing the magnetic field both on either side of the one rail and on either side of the other rail. By means of the method according to the invention, it is also possible to remove lumps of abraded iron material by energizing the magnet.

The method according to the invention may be carried out in various ways. According to a first possibility, the method according to the invention comprises the steps of:

providing flows of fluid which are at a distance apart from each other in the longitudinal direction of the railway line,
enclosing the magnetic field between the flows of fluid.

As an alternative or in addition thereto, the method according to the invention may comprise the step of directing the flows of fluid towards one another. In addition, the method may comprise the step of causing the flows of fluid to collide with one another.
Producing the desired flow of fluid may be achieved by means of spray nozzles on either side of the one rail and by means of spray nozzles on either side of the other rail.
The method may furthermore comprise the step of:

firstly causing the particulate material to swirl up,
subsequently subjecting the swirled-up particulate material to the magnetic field.

If the iron particles are swirled up only a short time before they are subjected to the magnetic field, they are still in a swirled-up state so that they can be directly displaced and removed by the magnetic field. However, it is not necessary to first make the iron particles swirl. Making the iron particles swirl and applying a magnetic field may also take place approximately simultaneously, provided that it is always ensured that the iron particles do not end up in a position where they are attracted by the iron reinforcement of the foundation which has been magnetized on account of the magnetic field.
The invention is furthermore related to a device for carrying out the method according to one of the preceding claims, comprising a trolley which is movable along a railway line having a gauge, a magnet structure, carrier means for carrying the magnet in such a position with respect to the railway line that particulate material or lumps of abraded iron material situated on that railway line are within the magnetic field generated by the magnet structure, and fluid spray means for releasing the particulate material from the railway line, wherein the fluid spray means have a spraying range which has a width which is larger than the gauge.
Such a device is disclosed in EP-A-418.428 as well. According to the invention, transfer means are provided for transferring the magnet structure between the position with respect to the railway line so that particulate material or lumps of abraded iron material on said railway line is/are within the magnetic field generated by the magnet structure, and a position with respect to a container so that particulate material or lumps of abraded iron material adhering to the magnet structure can be collected therein.
Good results can also be achieved if the spray nozzles are also spaced apart from one another in the longitudinal direction of the trolley. In that case, spray nozzles are provided on either side of the magnet structure, viewed in the longitudinal direction of the trolley. In that case, the ferrous particulate material which is situated beneath the magnet structures is reliably swirled up. In addition, the spray nozzles are prevented from producing a continuous flow in one direction, for example directed backwards or to the front. The drawback of such a continuous flow in a specific direction is that there is the risk that the particulate ferrous material could be blown away before it can be caught by the magnetic field.
Furthermore, the magnet structure is preferably designed in such a manner that it provides a magnetic field, the width of which is greater than the gauge. In particular, the magnet structure may comprise three magnets which are situated next to one another in the width direction and the maximum width of which is greater than the gauge. With this embodiment, the two outer magnets may be designed to fold up. As a result, the outer magnets may protrude far laterally with respect to the railway line, while forming no obstacle in the folded-up state when passing platforms and the like.
A further device is known from European patent 954,642 . In this case, a magnetic collecting device is arranged in front of the agitating means in the direction of movement of the device over the railway line. As has been described above, such a positioning of the agitating means and the magnet results in the problem that iron particles are attracted by the reinforcement in a concrete foundation which is magnetized on account of the magnetic field of the magnet.
According to the invention, this problem is solved by positioning the magnet, viewed in the direction of travel of the trolley, behind or at the same level as the swirl of particulate material to be produced by the agitating means. Such an orientation and position of the agitating means and the magnet with respect to one another prevents the iron particles from already adhering to the concrete foundation before they can be removed. As the particles are magnetized in the swirled-up state, they can be discharged in a reliable manner and without requiring a great force, for example by means of a jet of liquid.
Obviously, it is also possible to remove lumps of abraded iron material and the like from the railway line by means of the (energized) magnet.
The magnets are preferably electromagnets.
Below, the invention will be explained in more detail with reference to an exemplary embodiment of the device according to the invention illustrated in the figures, in which:

Fig. 1 shows a side view of the device according to the invention on a railway line.
Fig. 2 shows an enlarged detail of the side view from Fig. 1.
Fig. 3 shows a top view of the railway line at the location of the magnet structure.
Fig. 4 shows a front view of the magnet structure, in the folded-out state.
Fig. 5 shows a front view of the magnet structure in the folded-up state.

The device according to the invention and illustrated in Fig. 1 is situated on a railway line 1 comprising two raised rails 2 (one of which is shown) and a concrete foundation 3. This concrete foundation 3 comprises an iron reinforcement 4, embedded in a layer of concrete 5. The rails 2 are fastened to the concrete foundation 3 by means of fastening means which are denoted overall by reference numeral 6. Due to circumstances, such as grinding or wear of the rails 2, there is a layer of fine dust 7 on the concrete foundation 3, which essentially comprises iron particles. In addition thereto, this layer of dust 7 may also contain quartz which was formed during setting of the layer of concrete 5.
Such a layer of fine dust 7 comprising hard materials such as iron and quartz is highly undesirable, because such materials may end up on the running surfaces of the rails 2, as a result of which indentations may form. For the removal of the iron particles, the device according to the invention, as illustrated in Fig. 1, is used. This device comprises a trolley 8, which has a chassis 9 and wheels 10. On the chassis 9, a carrier 11 is provided for the magnet structure 12, which preferably comprises electromagnets. In addition, spray nozzles 13 are fitted to the chassis 9, which spray nozzles 13 are fed by the compressor 14. The magnet structure 12 can be energized by means of the power source 15. In addition, a container 19 is provided on the trolley 8, into which container 19 the dirt which has been collected can be deposited.
The trolley 8 is coupled to the wheeled vehicle 16, which is provided with an articulated arm 17. A magnet structure 12 is suspended from this articulated arm 17 by means of the connecting piece 18. The magnet structure 12 can be moved between its carrier 11 and the container 19 by means of this articulated arm 17.
When the device according to the invention is in use, the wheeled vehicle 16 together with the trolley 8 coupled thereto is moved along the railway line 1, namely to the right in Fig. 1, in the direction of arrow 20. A flow of air 21 is dispensed by the spray nozzles 13, in such a manner that the layer of fine dust 7 on the concrete foundation 3 is swirled up to form a cloud 22, as illustrated in Fig. 2. The magnet structure 12 is energized in such a manner that ferrous particulate material 23 from the layer of fine dust 7 adheres to the magnet structure 12. In this connection, it is important that the particles are already swirling before the reinforcement 4 of the concrete foundation 3 is magnetized by the magnetic field generated by the magnet structure 12. Thus, the ferrous particles 23 can no longer be attracted to the surface 24 of the concrete foundation 3 on account of the magnetized reinforcement 4. This may be achieved by providing the spray nozzle 13 slightly upstream of the magnet structure 12, viewed in the direction of travel 20. Spray nozzles 13 are also provided on the other side of the magnet structure 12, as is illustrated in the top view from Fig. 3, in such a manner that the swirled-up particulate material can remain localized to the area beneath the magnet structure 12. It is thus impossible for a flow in one direction to occur which would blow the particulate material away before it is caught by the magnetic field of the magnet structure 12. However, it is not absolutely essential that the spray nozzles 13 and the magnet structure 12 are oriented in this way with respect to one another, as long as it is ensured that the position of the spray nozzles 13 is such that the swirling action has started before the magnetic field of the magnet structure 12 takes effect. In other words, it has to be ensured that the ferrous particles 23 of the layer of fine dust 7 cannot be attracted to the surface 24 of the concrete foundation 3 by the magnetic field, but can be made to swirl.
As has already been mentioned before, it is possible to use the magnet structure 12 to also remove lumps of abraded iron material, which result from the use of water and an abrasive, from the railway line.
After an amount of ferrous particles 23 (or lumps of abraded iron material) has thus been collected on the magnet structure 12, the progress of the device along the railway line 1 is interrupted. By means of the articulated arm 17, the magnet structure 12, together with the amount of ferrous particles 23 or lumps of abraded iron material which adhere thereto, is lifted from the carrier 11 and moved to a position above the container 19. In this position, the excitation of the magnet structure 12 is cancelled, so that the particles 23 or lumps of abraded iron material fall into the container 19. Then, the magnet structure 12 is moved back onto the carrier 11 by means of the articulated arm 17, after which the progress of the device according to the invention along the railway line 1 can be resumed.
As has already been discussed above, there are also quartz particles on the concrete foundation 3. These quartz particles cannot be removed by means of the magnet structure 12, but conventional suction devices (not shown) can be used for the removal thereof which are known per se.
In Figures 4 and 5, a front view of the magnet structure 12 is illustrated. This magnet structure comprises three magnets 25, 26. The central magnet 25 extends between the two rails 2 and the magnets 26 are outside the rails 2. In this way, the region of the foundation both between and adjoining the rails 2 can be covered by the magnet structure 12. As is illustrated in Fig. 3, the spray nozzles 13 are not above but next to the rails 2, namely in front of and behind the magnet structure 12 viewed in the direction of travel 20. By this arrangement of the spray nozzles 13, the entire area of the foundation 3 which is covered by the magnet structure 12, can be influenced by the flow of fluid which emanates from the spray nozzles 13 positioned in this way.
Although six spray nozzles 13 are illustrated in Figures 3-5, it is also possible to use fewer or more spray nozzles, depending on the practical results. It is also possible to use spray nozzles with wide exit apertures, so that the entire region of the foundation 3 under the magnet structure 12 can still be swirled up, if desired, using fewer of such spray nozzles.
As illustrated in Figures 4 and 5, the outer magnets 26 are designed to be folded up. These magnets 26 are attached to bearing arms 27 which, in turn, are fastened to the magnet 25 by means of hinges 28. Under the effect of hydraulic piston/cylinder devices 29, the magnets 26 can be folded up or folded out. In the folded-up position, the magnet structure 12 is so narrow that it is possible to pass rail sections along platforms and the like without problems.
In the figures, the spray nozzles 13 are illustrated diagrammatically. The ducts, such as flexible hoses, by means of which the pressurized fluid is supplied to the spray nozzles 13 from the compressor 14, are not illustrated for the sake of clarity.
In the arrangement of the spray nozzles 13 illustrated in Figures 3-5, a spraying range is obtained which is more or less continuous in the width direction. Directly near the spray nozzles 13, the jet is possibly slightly stronger than next to the spray nozzles, but as a result of the reflection of the jet on the foundation 3, it is nevertheless possible to achieve such an evenness over the width of the railway line that the ferrous particulate material beneath the relatively wide magnet structure 12 can be swirled up in a reliable manner.
Such as illustrated in Fig. 3, the spray nozzles or jet nozzles 13 are arranged in such a manner that they face both sides of the adjacent rail, as indicated diagrammatically by the arrows. This direction is also indicated in Fig. 4, which figure also shows that the jets are directed at the core of the respective rails 2, that is to say the relatively narrow section just below the wide head and above the wide base. Abraded iron material which has collected there can therefore be swirled up in a reliable manner. In addition, the jets which are directed in such a manner cause a swirl over the entire width of the railway line and, as has already been mentioned above, also outside the rails, in the width direction. The distance between the, in the width direction outer, spray nozzles 13 is greater than the gauge.

Claims

Method for removing particulate material (7, 23) from a railway line (1) which comprises a foundation (3) and rails (2) which are raised with respect to the foundation, which particulate material (7, 23) at least comprises magnetizable particles, such as abraded iron material (23) or lumps of abraded iron material, which method comprises the steps of:
- causing the particulate material (7, 23) to swirl up on account of a flow of fluid,

- subjecting the swirled-up particulate material (7, 23) to a magnetic field,

- causing the particulate material (23) or lumps of abraded iron material to adhere to a magnet (12) which is in a collecting position under the effect of the magnetic field,

- removing the particulate material (7, 23) under the effect of this magnetic field,

- providing the flow of fluid both on either side of the one rail (2) and on either side of the other rail (2)
characterized by:

- periodically displacing the magnet (12) with particulate material (23) or lumps of abraded iron material attached thereto from the collecting position to a container (19),

- cancelling or reducing the magnetic field for depositing the particulate material (23) or lumps of abraded iron material in a container (19),

- returning the magnet (12) to the collecting position,

- restoring the magnetic field.
Method according to Claim 1, comprising the step of:
- providing the magnetic field both on either side of the one rail (2) and on either side of the other rail (2).
Method according to Claim 1 or 2, comprising the steps of:
- providing flows of fluid which are at a distance apart from one another in the longitudinal direction of the railway line (1),

- enclosing the magnetic field between flows of fluid.
Method according to Claim 3, comprising the step of:
- directing the flows of fluid towards one another.
Method according to Claim 3 or 4, comprising the step of:
- causing the flows of fluid to collide with one another.
Method according to one of the preceding claims, comprising the step of:
- providing the flow of fluid by means of spray nozzles (13) on either side of the one rail (2) and by means of spray nozzles (13) on either side of the other rail (2).
Method according to one of the preceding claims, comprising the steps of:
- firstly causing the particulate material (7, 23) to swirl up,

- subsequently subjecting the swirled-up particulate material (7, 23) to the magnetic field.
Method according to one of the preceding claims, comprising the steps of:
- causing the particulate material (7, 23) to swirl up,

- simultaneously subjecting the swirled-up particulate material (7, 23) to the magnetic field.
Method according to any of the preceding claims, comprising the step of:
- interrupting the swirling-up of the particulate material (7, 23) during the periodic displacement of the magnet (12).
Method according to one of the preceding claims, comprising the step of:
- carrying out a displacement along the railway line (1) while removing the particulate material (7, 23) or lumps of abraded iron material from the railway line (I).
Method according to one of the preceding claims, comprising the step of;
- causing the particulate material (7, 23) to swirl up under the effect of a swirl of air, as generated by a jet of air (21).
Method according to one of the preceding claims, comprising the step of:
- sucking up particulate material.
Device for carrying out the method according to one of the preceding claims, comprising a trolley (8) which is movable along a railway line (1) having a gauge, a magnet structure (12), carrier means (11) for carrying the magnet (12) in such a position with respect to the railway line (1) that particulate material (7, 23) or lumps of abraded iron material situated on that railway line (1) are within the magnetic field generated by the magnet structure (12), and fluid spray means (13, 14) for releasing the particulate material (7, 23) from the railway line (1), the fluid wherein spray means (13, 14) have a spraying range which has a width which is larger than the gauge, characterized in that transfer means (16, 17) are provided for transferring the magnet structure (12) between the position with respect to the railway line (1) so that particulate material (7) or lumps of abraded iron material on said railway line (1) is/are within the magnetic field generated by the magnet structure (12), and a position with respect to a container (19) so that particulate material or lumps of abraded iron material adhering to the magnet structure (12) can be collected therein.
Device according to Claim 13, wherein the spraying range of the fluid spray means (13, 14) has a regular or continuous pattern.
Device according to Claim 13 or 14, wherein several spray nozzles (13) may be provided with a maximum distance between them which is larger than the gauge.
Device according to one of Claims 13-15, wherein at least three spray nozzles (13) are provided which are evenly distributed in the width direction of the trolley (8).
Device according to one of Claims 13-16, wherein, viewed in the longitudinal direction of the trolley (8), spray nozzles (13) are provided on either side of the magnet structure (12).
Device according to one of Claims 15-17, wherein the magnet structure (12) is designed to provide a magnetic field, the width of which is greater than the gauge.
Device according to Claim 18, wherein the magnet structure (12) comprises three magnets (25, 26) which are situated next to one another in the width direction and the maximum width of which is greater than the gauge.
Device according to Claim 19, wherein the two outer magnets (26) are designed to be folded up.
Device according to one of Claims 13-20, wherein the mutual distance between the spray nozzles (13) which are furthest apart in the width direction, is greater than the gauge.
Device according to one of Claims 13-21, wherein the trolley (8) is provided with the container (19) for collecting particulate material or lumps of abraded iron material which adhere(s) to the magnet (12).
Device according to any of claims 19-22, wherein the transfer means comprises a wheeled vehicle (16) provided with an articulated hydraulic arm (17), from which arm (17) the magnet structure (12) is suspended.
Device according to Claim 23, wherein the trolley (8) is coupled to the wheeled vehicle (16).
Device according to one of Claims 13-24, wherein the magnet structure (12) comprises one or more electromagnets.
Device according to one of Claims 13-25, wherein a suction device is provided for sucking up particulate material.