EP3297398B1 - Device for heat-treating objects, in particular tubes and containers made of metal - Google Patents

Description

The present invention relates to a device for the heat treatment of objects, in particular pipes and containers made of metal.

Generic devices are known in many different ways and are used for preheating objects that have to be welded together, for example. The objects are heated accordingly on both sides of the intended weld. The desired temperature distribution must be generated by appropriate geometric design of the inductor.

With stationary heating, there is no relative movement between the welded parts and the inductor. In this case, the inductor is usually designed to be flexible. The inductor can be a cable, for example made of copper braid, self-cooling or water-cooled. The inductor and the welded part are arranged at the smallest possible distance from each other, since the inductor efficiency decreases sharply with increasing distance and the electromagnetic stray field, which is dangerous to people, rises sharply.

With rotating heating, there is a relative movement between the welded parts and the inductor. The stationary inductor must also be kept a short distance from the surface of the parts to be heated. In this case, both rigid inductors made of water-cooled copper profile tube and flexible inductors are used. Rigid and flexible inductors have to be kept at the minimum possible distance from the welded parts by means of complex equipment being held. Any change in the geometry of the welded parts leads to considerable effort on the inductor and the holding apparatus.

Out US 4,388,510 a generic device for heating pipes is known in which an electrical conductor (inductor) through which alternating current flows generates an alternating electromagnetic field. The inductor is arranged in segment-like parts which are rigid and are arranged around the tube. The rigid segments have on their inside a radius of curvature which corresponds to the radius of curvature of the outer wall of the pipe to be heated. The device has rollers, by means of which the device rests on the outer wall of the tube and can be moved along the longitudinal direction of the tube. In the area of action of the alternating electromagnetic field, the pipe, which consists of electrically conductive material, is heated by induced eddy currents. If the pipe material also has ferromagnetic properties, there is additional heating due to magnetic reversal losses. From US 4,388,510 before known devices show that due to the rigid design of the segments and their defined inner radius, only tubes of a certain outer diameter can be heated by means of this device. If, for example, this device is placed on a pipe with a much larger outer radius, the inductor does not lie at a uniform distance over the circumference of the pipe, so that uniform heating of the pipe material is not possible.

Out US 4,595,607 a device for warming up objects is also known, which also consists of a plurality of rigid segments which can be pivoted relative to one another. The segments also have a defined inner radius which is adapted to the inner radius of the object or pipe to be heated. The individual segments can be spread or pulled together using belts or chain drives. In the spread state, the device can be placed on a pipe, after which the individual segments are then placed around the pipe using the belt. The inductors are arranged in the segments. This device also has the disadvantage that only Objects or pipes with a defined outer diameter can be warmed up.

Out DE 2340722 a device and method for heat treatment of steel tubes is also known, in which the area of heat treatment is encompassed by a semicircular heating device, the tube being rotatable about its axial axis under the device. This device also has the disadvantage that only pipes of a very specific diameter can be processed. Furthermore is off WO 2007/128384 A2 a hand-held device for welding plastic pipes is known, which has a chain that can be placed around a special pipe connector and is closed with a plug at the upper end of the hand-held device. The pipe connector, which is made of plastic like the pipes to be connected, has a metal ring which lies between the inside diameter of the pipe connector and the outside diameter of an inserted pipe. This can be heated by high-frequency AC induction, so that the surrounding plastic material melts. Electrical conductors run within the chain to induce the AC voltage. To weld pipes with different diameters, the chain part must be replaced by a chain part whose length is adapted to the respective outer diameter of the pipe connector used. The object of the present invention is therefore to provide a device for the heat treatment of objects which can be used for objects with a wide variety of external radii of curvature.

This object is achieved according to the invention with a device which is formed by a chain composed of chain links, the chain links being connected to one another in a rotatable or pivotable manner, and in that at least one electrical conductor in the form of an inductor is arranged in or on the chain. At least one coolant, in particular in the form of a cooling hose, can be arranged in or on the chain.

The chain according to the invention is constructed in principle like a known energy chain. It can have a rectangular cross section, in the interior of which the electrical cables or conductors are located. So the chain can Have start and an end piece, which are connected by many identical chain links. It is also possible that the chain links can be opened externally or internally so that conductors can also be inserted or removed from the chain, even if the individual chain links are connected to one another. The chain links can have longitudinal webs that separate the individual conductors from one another. It also makes sense if the conductors are clamped at the beginning and end of the chain with strain relief.

The chain links are advantageously opened on their side facing the object in such a way that the thermal resistance between the electrical conductor and the object is as small as possible.

In order for the at least one inductor of the device to be kept at a defined, as small as possible distance from the surface of the object, the chain has rollers which serve, as it were, for rolling and / or for contacting the object to be heated, the pivot axis of the chain links pivotally connected to one another at the same time can form the axis of rotation for the rollers. At least one roller can be arranged on each, every second or third chain link.

So that the device can be guided or moved both in the circumferential direction and axially along the object, in a further development of the device the rollers can allow the object to roll in the longitudinal direction of the chain and / or transversely thereto. So it is possible to store ball bearings or the bearings of the rollers themselves so that they can be pivoted.

So that the chain according to the invention can lie on curved surfaces as close as possible, the length of a chain link is as short as possible than the eighth part of the circumference of the object to be treated.

In the simplest case, the chain links have straight side parts, such that the chain can also lie flat on a flat surface. However, it is it is also possible for the side parts to have a, in particular slight, curvature on their side facing the object.

So that the chain does not heat itself, it is made of an electrically non-conductive and non-ferromagnetic material.

That the chain rests securely on the outer wall of the object during the entire heat treatment can be achieved by at least one traction means encompassing the object, which presses the chain against the outer wall of the object. The traction means is advantageously tensioned, and the necessary tension can be ensured by appropriate spring elements.

The at least one traction means can rest on the outside of the chain or by at least one chain link, e.g. be guided through one or more eyelets formed or attached to the chain links.

The invention also provides that two or more chains are put together to form a long chain. The ends of the chains can be attached to each other for this purpose. It is also possible that another chain is arranged parallel to a chain. The chains arranged parallel to one another can also be connected to one another if the chains and connecting elements are designed accordingly.

1. a) die Kette kann leicht an der Oberfläche der Schweißteile durch Seilspanner oder dergleichen befestigt werden;
2. b) die Kette bedeckt das Schweißteil partiell bis vollumfänglich;
3. c) es kann zunächst die rollende Kette und danach der eigentliche Induktor in die Kette montiert werden; Änderungen der Kettenlänge sind leicht möglich. Auch das Verbinden von vormontierten Ketten mit darin befindlichen Induktoren ist möglich;
4. d) der in der Kette einliegende Induktor kann ein Flächeninduktor sein, welcher aus mehreren Teilinduktoren in Reihen- und Parallelschaltung zusammengesetzt ist;
5. e) der Induktor kann im Bedarfsfall auch aus starren und flexiblen Segmenten bestehen;
6. f) die Kette schmiegt sich problemlos an unterschiedliche Durchmesser der rotationssymmetrischen Schweißteile an;
7. g) bei Abweichungen von der Rotationssymmetrie legt sich die Kette dennoch mit geringem Abstand an die des zu behandelnden Gegenstandes an.

In addition to the known methods and devices, the device according to the invention has the following innovations and advantages:

1. a) the chain can be easily attached to the surface of the welded parts by rope tensioners or the like;
2. b) the chain partially or completely covers the welded part;
3. c) first the rolling chain and then the actual inductor can be installed in the chain; Changes in chain length are easily possible. It is also possible to connect pre-assembled chains with inductors located in them;
4. d) the inductor lying in the chain can be a surface inductor which is composed of several partial inductors in series and parallel connection;
5. e) if necessary, the inductor can also consist of rigid and flexible segments;
6. f) the chain adapts easily to different diameters of the rotationally symmetrical welded parts;
7. g) in the event of deviations from the rotational symmetry, the chain nevertheless places itself at a short distance from that of the object to be treated.

Various possible embodiments of the device according to the invention are explained in more detail below with reference to drawings.

Show it:

Figure 1:

Cross-sectional view through a tube with two chains according to the invention arranged around it;

Figure 2:

Side view of a container on which two chains according to the invention are arranged for warming up the area of a weld seam to be made;

Figure 3:

Top view of a chain according to the invention that has just been laid;

Figure 4:

Top view of the chain according to Figure 3 with inductor arranged therein;

Figure 5:

Chain according to the invention with rollers which enable the chain to be moved on an object transversely to the longitudinal direction of the chain;

Figure 6:

two chains connected at the front;

Figure 7:

Chain according to Figure 3 with an inductor arranged in the chain, which at the same time enables cooling;

Figure 8:

Chain according to Figure 5 with an inductor that can be controlled to warm up and cool down;

Figure 9:

Cross-sectional view through a tube with chains around it according to another possible embodiment;

Figure 9a:

schematic cross-sectional view through the surface of an object with a chain arranged thereon;

Figure 10:

Device according to the invention with a support for a tube with a chain that can be tensioned around it, the tube being rotatable about its longitudinal axis under the fixed chain;

Figure 11:

alternative embodiment for the rotatable mounting of a pipe to be treated, in which the chain is laid around more than 80% of the circumference of the pipe.

The Figure 1 shows a cross-sectional view through a pipe R with two chains K1 and K2 according to the invention arranged around it. The chains K1 and K2 are each formed by interconnected chain links 1, the chains K1 and K2 having rollers 1a with which they rest on the outer wall of the tube R. Not shown are traction means or tensioning means with which the chains K1 and K2 are pressed against the outer tube wall. The rollers 1 define the distance AB of the inductors arranged in the chain links 1.

The Figure 2 shows a side view of a container B, on which two chains K1 and K2 according to the invention are arranged for warming up the area of a weld seam SN to be made. The chains K1 and K2 can be pressed against the outer wall of the container B by a chain holder (not shown). The chain holder can be designed such that it slowly moves the chains K1 and K2 to the left of the weld seam SN. However, it is also possible for wires to be stretched around the container, with which the chains are fixed in their illustrated position. The inductor IN is a surface inductor that covers the entire surface of the container B, which are covered by the chains K1 and K2, can be heated.

The Figure 3 shows a plan view of a chain according to the invention which has just been laid and which is formed from a plurality of chain segments 1. The chain segments have transverse webs 1B which connect the side parts 1c of the chain links 1 to one another.

The Figure 4 shows a top view of the chain according to Figure 3 with inductor IN arranged therein. The inductor IN has several turns, its connections INa being led out of the chain end K1a.

The Figure 5 shows a chain according to the invention with rollers 1a, which allow movement of the chain on an object transverse to the longitudinal direction LR of the chain. It is also possible for the rollers 1a to be pivotally mounted on the chain links 1 about the axes 1a ', so that the chain can in principle be moved in any direction over the surface of the object.

The Figure 6 shows two chains K1 and K2 connected to one another at the end by means of the connecting parts V.

The Figure 7 shows a chain according to Figure 3 with an inductor arranged therein, which at the same time enables cooling of the object.

The Figure 8 shows a chain according to Figure 5 with an inductor which can also be heated and cooled in a controlled manner, the rollers 1a being pivotally mounted about the axis 1a 'or being rigidly attached to the chain links in the position shown, so that the chain can be rolled across the object transversely to its longitudinal direction.

The Figure 9 shows a cross-sectional view through a pipe R with chains K1 and K2 placed around it according to a further possible embodiment. These chains also consist of interconnected chain links 1 with rollers 1a arranged thereon. This inductor IN also has additional cooling K. The two chains can be connected to one another via their end links. The water-cooled inductors can e.g. B. be a surface inductor (above) and a comprehensive inductor.

The Figure 9a shows a schematic cross-sectional view through the surface Go of an object G with a chain arranged thereon. The inductors IN are arranged in the longitudinal direction LR (perpendicular to the plane of the drawing) within the chain links 1. Laterally, the rollers 1a are rotatably mounted on the chain links 1 and keep the inductors IN at a certain distance AB from the object surface Go.

The Figure 10 shows a device according to the invention with supports L1, L2 for a tube R. From above, a chain K1 according to the invention is placed on the tube R, which chain is held in position by means of the tensioning means S. The tensioning means S is fastened at 9 to the device floor or hall floor, spring elements F being arranged in the tensioning means, which hold the tensioning means S under tension, whereby the chain K1 is pressed firmly against the outer tube wall. The tube can be rotated around its longitudinal axis, so that a continuous weld seam can be produced. If a chain according to Figure 5 or 8th is used, the tube R can also be moved in the axial direction (perpendicular to the plane of the drawing), provided the bearings L1 and L2 are designed accordingly, whereby an axially extending weld seam can also be made with this device.

The Figure 11 points to the device according to Figure 10 alternative embodiment in which the chain is wrapped around more than 80% of the circumference of the tube R. This is possible because the clamping device S encloses the tube by more than 360 °.

Claims (18)

1. Device for the heat treatment of objects (G), in particular of tubes (R) and containers (B) made of metal, wherein the device comprises a chain (K1, K2) composed of chain links (1), wherein the chain links (1) are rotatably or pivotably connected to one another, and the device comprises at least one electrical conductor (IN) arranged in or on the chain (K1, K2), characterised in that the chain (K1, K2) has rollers (1a) which serve for rolling and/or bearing against the object (G) to be heated.
2. Device according to claim 1, characterised in that at least one coolant (K), in particular in the form of a coolant hose (K), is arranged in or on the chain (K1, K2).
3. Device according to claim 1 or 2, characterised in that the chain links (1) each have two side parts (1c) which are connected to one another via at least one connecting web or at least one connecting wall (1b).
4. Device according to claim 1 or 2, characterised in that the chain links (1) each have two side parts (1c) which are connected to one another via at least two connecting webs, and in that the webs (1b) together with the two side parts (1c) form a window-like, in particular rectangular, access opening (12) through which the electrical conductor (IN) and/or the coolant (K) pass.
5. Device according to any one of claims 1 to 4, characterised in that the chain links (1) are open on their side (1g) facing the object (G) in such a way that the electromagnetic resistance between the electrical conductor (IN) and the object is as low as possible.
6. Device according to any one of the preceding claims, characterised in that the pivot axis (A1) of the pivotally interconnected chain links (1) simultaneously forms or is the axis of rotation for the rollers (1a).
7. Device according to one of the preceding claims, characterised in that at least one roller (1a) is arranged on each chain link or every second or third chain link (1).
8. Device according to one of the preceding claims, characterised in that the rollers (1a) allow rolling on the object (G) in the longitudinal direction (LR) of the chain (K1, K2) and/or transversely thereto.
9. Device according to any one of the preceding claims, characterised in that the rollers (1a) are rotatably mounted in a first bearing part (1r), wherein the bearing part (1r) itself is rotatably or pivotably mounted on the chain link (1).
10. Device according to one of the preceding claims, characterised in that the length (1n) of a chain link (1) is shorter than the eighth part of the circumference (U) of the object (G) to be treated.
11. Device according to one of the preceding claims, characterised in that the chain links (1) have straight side parts (1c), such that the chain (K1, K2) can also rest flat on a flat surface.
12. Device according to claim 3, characterised in that the side parts (1c) have an, in particular slight, curvature (KR) on their side facing the object (G).
13. Device according to any one of the preceding claims, characterised in that the chain links (1) are engaged with one another.
14. Device according to any one of the preceding claims, characterised in that the chain links (1) are made of an electrically non-conductive and non-ferromagnetic material.
15. Device according to one of the preceding claims, characterised in that the device can be pressed against the outer wall (Go) of the object (G) by means of at least one traction means (S) guided around the object (G) and tensioned.
16. Device according to claim 15, characterised in that the traction means rests on the outside of the chain (K1, K2) or is guided by at least one chain link (1).
17. Device according to one of the preceding claims, characterised in that several chains (K1, K2) can be attached to each other with their ends (K1a, K2a).
18. Device according to one of the preceding claims, characterised in that at least one electrical conductor or inductor extends over or is inserted into more than one chain (K1, K2).

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