WO2023139339A1

WO2023139339A1 - Thermite-weld cooling device

Info

Publication number: WO2023139339A1
Application number: PCT/FR2023/050084
Authority: WO
Inventors: Armand KANJER; Lionel Winiar; Imad ERRABIE
Original assignee: Pandrol
Priority date: 2022-01-21
Filing date: 2023-01-20
Publication date: 2023-07-27
Also published as: FR3132039A3; FR3132039B3

Abstract

The invention relates to a device (10) for cooling a thermite weld (70) of a rail, comprising - a reservoir (2) suitable for storing a volume of water, - a pump (3), - an electronic control system (4) for controlling the pump (3), - a control button (8) for triggering the control system (4), - a spray lance (6) comprising a nozzle (61), said spray lance (6) being connected to the reservoir (2) via the pump (3), - a housing (1) from which the spray lance (6) projects towards the thermite weld (70) - and a support (7), the cooling device (10) being characterized in that the electronic control system (4) is suitable for triggering the spraying of a jet of water, from the nozzle (61) onto a weld (70) made on said rail, when an operator actuates the control button (8).

Description

THERMAL WELDING COOLING DEVICE

FIELD OF THE INVENTION

The present invention relates to a thermite weld cooling device for welding railway rails.

STATE OF THE ART

Thermite welding is a process frequently used to repair and/or make joints in metal rails, and in particular railway rails. To produce such a weld, a mold comprising several parts is used which grips the metal sections, thus forming a molding cavity containing the ends of the metal sections to be welded and intended to receive the molten metal.

Molten metal requires cooling in order to solidify. It is desirable to accelerate this cooling in order to limit in time the steps inherent in the realization of a weld which can be linked over two consecutive days. However, if the cooling is too rapid, it can lead to a quenching of the weld which modifies the metallurgical properties of the cast metal during welding and often results in hard but fragile microstructures and consequently a risk of rupture of the weld produced. It is therefore necessary to adapt the cooling parameters to the dimensions of the weld.

It is known to accelerate cooling by applying a jet of cold water to the weld. Systems allowing such cooling on site are often heavy and bulky or comprise a plurality of modules which must be connected and installed separately. It is therefore difficult to install them close to the welding to be carried out on a railway site. Spray parameters, water flow and cooling temperatures in these systems are not optimized for thermite rail welds.

Due to the known hardenability risk of steels as previously described, it is difficult to randomly cool a weld. The only known possibility is to spray water directly on the weld in order to speed up the implementation while guaranteeing a standardized welding quality. However, it is difficult to control parameters such as the water flow, the temperatures at the start of cooling or the water spray pressure.

In addition, since the welds are carried out on a railway line, operators must be able to use reliable, light, robust and easy-to-use equipment. For this, it is It is also desirable to improve the portability and ease of operation of the cooling system for such welds.

DISCLOSURE OF THE INVENTION

An object of the invention is to provide a compact, portable cooling device, easy to install on railway worksites, the cooling power of which is optimized for the thermite welds of the rails. To this end, the invention proposes a device for cooling a thermite rail weld, comprising o a tank suitable for storing a volume of water, o a pump, o an electronic control system for controlling the pump, o a control button for triggering the control system, o a spray rod comprising a nozzle, said spray rod being connected to the tank via the pump, o a box in which the tank and the pump are arranged and from which the spray rod protrudes in the direction thermite welding, o a support adapted to be removably mounted on a rail and is integral with the casing, characterized in that the electronic control system is adapted to trigger the projection of a jet of water by the nozzle after actuation of the control button by an operator on a weld carried out on the said rail.

Advantageously, the electronic control system is configured to stop the projection of the water jet automatically after a pre-programmed projection time.

Preferably, the electronic control system is suitable for triggering the projection of the water jet after a waiting time after the control button has been pressed.

Advantageously, the device further comprises a user interface capable of receiving a waiting time and/or a projection time of the water jet entered by the user.

In some embodiments, the device further comprises a display device capable of displaying the quantity of water present in the reservoir and/or a waiting time after completion of the weld and/or a projection time of the water jet. Advantageously, the tank has an internal volume of between 5 and 20 liters.

Preferably, the electronic control system is configured to trigger the projection of a quantity of water of between 5 and 10 liters.

Advantageously, the spray cane is pivotable in a horizontal plane and/or a vertical plane, so as to adjust the orientation of said spray cane with respect to the aluminothermic weld to be cooled.

In certain embodiments, the spray rod comprises several tubes each comprising a nozzle, said nozzles being oriented along distinct axes with respect to the aluminothermic weld to be cooled.

Advantageously, the device further comprises a carrying handle for the case and/or a housing for a removable battery suitable for electrically powering the pump and the electronic control system.

In some embodiments, the device further comprises a system for measuring the temperature of the solder, and electronic control determines the duration of the spraying of water as a function of the measured temperature.

Preferably, the device further comprises a connector suitable for establishing a fluid connection between a water reservoir external to the housing and the pump.

BRIEF DESCRIPTION OF FIGURES

Other characteristics and advantages of the invention will emerge from the detailed description which follows, with reference to the appended drawings, in which:

Figure 1 is a perspective front view of the system with its mounting bracket on the rails.

Figure 2 is a perspective front view of the system, with no representation of the case to illustrate the layout inside the system.

Figure 3 is a rear perspective view of the system with its installation support on the rails.

Figure 4 is a rear perspective view of the system, with no representation of the case to illustrate the layout inside the system.

DETAILED DESCRIPTION OF EMBODIMENTS

Presentation of the device

FIG. 1 schematically illustrates a cooling device 10 according to the invention. The cooling device 10 comprises a box 1 secured to a support 7 adapted to be mounted on a rail. The rail is typically a railway rail on which a thermite welding 70 is to be carried out, either for a maintenance or repair operation, or to join said rail to a second rail to build a railway track. Bracket 7 may include screws, clamps or other devices to temporarily secure bracket 7 to the rail.

Referring to Figure 2, the box 1 includes a tank 2 in which a volume of water is stored. Typically, the capacity of tank 2 is around 5 to 20 liters. Tank 2 and housing 1 include a filling hole to fill tank 2 with water. The filling orifice may be closed by a cap 22 or a valve or other closing device. In an illustrative and non-limiting way, the tank 2 is arranged in the upper part of the box 1. However, the tank 2 can be arranged in the lower part or at another location in the box 1. The tank 2 can also include a water level sensor. Protection elements 21 made of foam can be arranged on the outer walls of the tank.

Referring to Figures 3 and 4, the box further comprises a housing 50 arranged to receive a rechargeable battery (not shown).

Preferably, the box 1 is provided with a handle 11 to transport the cooling device 10 comprising a volume of water to the place where the aluminothermic welding 70 must be carried out. The handle can also be used to facilitate installation of the system on the job site. Such a handle 11 can be made of metal or plastic or any other material suitable for transporting the device with a quantity of water included in the tank 2. The handle 11 can be screwed, riveted or fixed in any other appropriate way on the box 1.

A spray rod 6 comprising a nozzle 61 protrudes from the box 1. A seal can be arranged between the rod 6 and the box 1. Advantageously, the spray cane 6 has a substantially horizontal portion 66, a curved portion 67 downwards and a substantially vertical portion 68, at the end of which the nozzle 61 is arranged. The length of the substantially horizontal portion is typically between 50 mm and 300 mm, and the length of the substantially vertical portion is typically between 30 mm and 150 mm. A second seal is typically arranged between the rod 6 and the nozzle 61. The curved portion can be oriented at a right angle or any other obtuse or acute angle suitable for orienting the nozzle 61 towards the rail.

In other embodiments (not shown), the spray cane may include a multiple nozzle. For example, such a multiple nozzle may include three tubes and three nozzles, one of which is oriented to spray water onto the weld in a vertical direction. Two other tubes and nozzles can be arranged in both respective sides with respect to the plane (X, Y) of a weld, so as to spray water onto the weld in a horizontal or oblique direction.

Preferably each nozzle 61 is removable, in order to adapt the type and geometry of the nozzle 61 to the weld to be cooled.

By "vertical" is meant in the present text, as commonly accepted, in the direction of gravity. “Horizontal” means perpendicular to the vertical. The description of the cooling device is made assuming that the running surface of the rail extends in a horizontal plane, as shown in the figures.

Preferably, the spray rod 6 is movably mounted on a specific pivoting connection on the housing 1 allowing the nozzle 6 to be mounted and removed with ease. To this end, the spray cane 6 may have a horizontal pivot axis Y corresponding to an axis of revolution of the horizontal portion 66 of the cane 6 and extending perpendicularly to an opening of the housing 1 in which the cane 6 is mounted. In a complementary or alternative manner, the spray cane 6 can have a vertical pivot axis X at the level of the horizontal portion 66 of the cane 6, for example near the junction between said horizontal portion 66 of the cane 6 and the box 1.

When the support 7 is mounted on a rail, the nozzle 61 is oriented in the direction of the aluminothermic welding 70 to be carried out on the rail. When the cane 6 is movable in pivoting, its orientation can be adjusted after mounting the support 7 on the rail in order to take up mechanical play and adjust the perpendicularity between the spray cane 6 and the support and/or the rail.

The box 1 further comprises a water pump 3. A person skilled in the art will know how to choose a suitable pump 3 according to its weight and the size in the box 1 . Pump 3 is connected to water tank 2 and nozzle 6, so as to transfer water from tank 2 to spray cane 6 and nozzle 61 . The spray parameters can be adjusted by adjusting the flow rate of the pump. Alternatively, the nozzle can be changed to change the spray rate. A water filtration system can also be added, for example to protect the pump and the nozzle from impurities potentially present in the volume of water.

The system further comprises an electronic control system 4 which is arranged inside the box 1 and can be triggered via a control button 8 mounted on the box 1 . The electronic control system 4 is used to control the pump 3. If sensors are present in the system, the data measured by these sensors are transmitted to the electronic control system 4. The electronic control system can also be used for time management standby and/or to establish a wireless connection, for example a Bluetooth connection, with an external computer system.

A power source (not shown), typically a rechargeable battery, having sufficient power to power the pump 3 and the electronic control system 4, is removably inserted into the housing 50. The pump 3 is connected to the electronic system 4 itself connected to the power source. A voltage regulator 51 is inserted between the power source and the electronic control system 4 in order to transfer a stable voltage to the pump 3. This arrangement makes it possible to stabilize the water spray rate. The electronic control system can thus be used for the monitoring and protection of an energy source.

Optionally, the system can include a user interface which can be protected by a shutter 9 connected to the electronic control system. Such a user interface can receive a time entered by a user, such as a waiting time after finalizing a weld or a duration of water projection. The user interface can be a simple means of adjustment such as one or two buttons, a slider or an adjustment wheel. In other embodiments, more complex user interfaces comprising several elements can be mounted. The system may further comprise a display device, for example a seven-segment single or multiple LED display. The display can show various system parameters, such as a waiting time and/or a water projection duration entered by the user, and/or a quantity of water present in the tank and measured by means of a sensor or any other parameter relating to the cooling or the welding process.

The device may further comprise a temperature measuring means for determining the temperature of the aluminothermic weld. Such a temperature measuring means is connected to the electronic control system and comprises a temperature sensor, for example a pyrometer capable of measuring the temperature of the weld 70 at the distance of the box 1 from the location of said weld 70.

For filling reservoir 2, the system may further comprise a connector adapted to establish a fluid connection between the filling orifice and an external reservoir via a conduit. In this case, the pump 3 can be used to pump water directly from the external tank to the spray cane 6 and the nozzle 61, once this external tank is connected to the cooling device 10.

Use

We will now describe the use of the cooling device 10 for a thermite welding 70 of a rail. Before making a thermite weld 70 at a defined location on a rail, the user fills the tank 2 with a volume of water and installs the device via the support 7 on a rail close to the weld to be made. He fixes the support 7 on the rail at an appropriate distance from the weld 70. If the spray cane 6 is pivotable around one or two axes, the user adjusts the spray cane 6 so that the nozzle 61 is oriented towards the weld 70 to be made.

The cooling device 10 is thus installed on the site and fixed close to the aluminothermic weld 70 to be produced. No other connection or mechanical installation, such as the fitting of pipes or a pump, is necessary for the operation of the system and no other peripherals are necessary for the operation of the device 10. Installation is therefore simple and quick to perform, and the space occupied by the cooling device 10 on the construction site is minimal.

When the nozzle is equipped with an adjustment device, the user adjusts the flow rate and/or the degree of spray according to the thermite weld. It can take into account parameters such as the type of weld, which can be a repair weld for different types of defects or a weld to join two rails. The user can also adjust the nozzle setting based on weld geometry and volume or material properties or temperature. In other embodiments, the flow rate and/or the degree of spray are fixed. When the cooling device includes a user interface capable of receiving a waiting time, the user programs a waiting time according to the parameters of the aluminothermic welding. When the cooling device comprises a temperature measurement means and a user interface capable of receiving a welding cooling temperature, it adjusts the orientation of the temperature sensor on the welding and a welding cooling temperature is programmed according to the parameters of the aluminothermic welding.

An operator then performs the thermite welding 70.

Immediately after the completion of thermite welding 70, the user waits for a waiting time predefined in a protocol, and then presses the control button 8. He adjusts, if necessary, the duration of the water spray and then triggers the system with commands located at the level of the user interface under the flap 9. Alternatively, when the user has programmed a waiting time via the user interface, he presses the control button 8 immediately after the completion of the weld 70 and the device is in a waiting state for the programmed time. Alternatively, if the device includes means for measuring the temperature of the weld 70, the user presses the control button 8 immediately after the completion of the weld 70 and the device is in a waiting state until the programmed temperature is reached. After pressing the control button or, where applicable, once the waiting time has elapsed or the programmed temperature has been reached, the electronic control system 4 triggers the cooling of the weld 70 and the pump 3 is started. The pump 3 transfers water from the reservoir 2 to the nozzle 61, so as to spray a defined quantity of water on the weld 70. The defined quantity of water is for example between 5 and 10 liters. With regard to the flow rate adjustment, a protocol is defined which uses a low flow rate, but which nevertheless allows intense cooling of the weld 70. It is thus sought to optimize the water consumption, which must be low in order to minimize the weight and the size of the cooling device 10 and to avoid problems with the water supply on the site, while applying an efficient cooling process which saves time in the welding process.

After the ejection of a defined quantity of water, or the ejection of water at a defined rate for a defined period of time, the electronic control system 4 interrupts the supply to the pump 3. The spraying of water on the weld 70 is therefore stopped. The thermite weld 70 is cooled sufficiently to remove the chiller, mold, and any other materials used to make the weld. Said material can thus be used for other welds to be made.

Weld cooling

The aluminothermic weld thus undergoes a first stage of natural cooling directly after the welding process. This step is slower than cooling by spraying water and avoids quenching the molten metal. In fact, too rapid cooling often leads to stresses in the weld and can have a negative effect on the quality of the weld, in particular its mechanical stability. In some cases, such stresses can cause deterioration or even breakage of the weld. The natural cooling of the hot molten metal of a weld therefore promotes a good metallurgical quality of the weld.

In a second step, after having reached a certain temperature by natural cooling, the weld is cooled in an accelerated but controlled manner by spraying water. Such cooling is desirable in order to solidify the metal more quickly without the adverse effects described above, allowing the removal of the mold and any other material used during the weld. This saves time on the entire site procedure.

Claims

9 CLAIMS

1. Device for cooling (10) a thermite weld (70) of rail, comprising o a tank (2) suitable for storing a volume of water, o a pump (3), o an electronic control system (4) for controlling the pump (3), o a control button (8) for triggering the control system (4), o a spray rod (6) comprising a nozzle (61), said spray rod (6) being connected to the tank (2) via of the pump (3), o a casing (1) in which the reservoir (2) and the pump (3) are arranged and from which the spray pipe (6) protrudes in the direction of the aluminothermic welding (70), o a support (7) adapted to be removably mounted on a rail and is integral with the casing (1), characterized in that the electronic control system (4) is adapted to trigger the projection of a jet of water by the nozzle (61) after actuation of the control (8) by an operator on a weld (70) performed on said rail.

2. Cooling device (10) according to claim 1, wherein the electronic control system (4) is configured to stop the projection of the water jet automatically after a preprogrammed projection time.

3. Cooling device (10) according to any one of the preceding claims, in which the electronic control system (4) is adapted to trigger the projection of the jet of water after a waiting time after the actuation of the control button (8).

4. Cooling device (10) according to any one of the preceding claims, further comprising a user interface capable of receiving a waiting time and/or a projection time of the water jet entered by the user.

5. Cooling device (10) according to any one of the preceding claims, further comprising a display device capable of displaying the quantity of water present in the tank (2) and/or a waiting time after completion of the weld and/or a projection time of the water jet. Cooling device (10) according to any one of the preceding claims, in which the tank (2) has an internal volume of between 5 and 20 litres. Cooling device (10) according to any one of the preceding claims, in which the electronic control system (4) is configured to trigger the spraying of a quantity of water comprised between 5 and 10 litres. Cooling device (10) according to any one of the preceding claims, in which the spray rod (6) is pivotable in a horizontal plane and/or a vertical plane, so as to adjust the orientation of the said spray rod (6) with respect to the aluminothermic weld (70) to be cooled. Cooling device (10) according to one of the preceding claims, in which the spray pipe (6) comprises several tubes each comprising a nozzle, the said nozzles being oriented along distinct axes with respect to the aluminothermic weld (70) to be cooled. A cooling device (10) according to any preceding claim, further comprising a handle (11) for transporting the case. Cooling device (10) according to any of the preceding claims, further comprising a housing (50) for a removable battery adapted to electrically supply the pump and the electronic control system. A cooling device (10) according to any preceding claim, further comprising a solder temperature measurement system (70), in which the electronic control system (4) determines the duration of the spraying of water as a function of the measured temperature. Cooling device (10) according to any one of the preceding claims, further comprising a connector adapted to establish a fluid connection between a water reservoir external to the housing (1) and the pump (3).