Oven arrangement

Abstract

The invention relates to a furnace arrangement (100) with a tube annealing furnace (1). The tube annealing furnace (1) has tube holders (9) in which tubes (2) are individually stored. Heat generated by a heating device is transferred to the tubes (2) stored in the tube holders (9) by thermal conduction. The tube annealing furnace (1) has a modular arrangement (4) of furnace modules (5), wherein each furnace module (5) has a module body (8) made of thermally conductive material, in which at least one tube holder (9) for a tube (2) and at least one receptacle spaced apart from the tube holder (9) for an electric heating element are provided. The heat generated by the electric heating element is transferred by thermal conduction via the module body (8) to the tube (2) stored in the tube holder (9), wherein each furnace module (5) is at least partially surrounded by a heat-insulating material.

Description

[0001] The invention relates to a furnace module with a tube annealing furnace.

[0002] Such tube annealing furnaces are used for annealing tubes, especially aluminum tubes.

[0003] Aluminum tubes are typically manufactured seamlessly using cold extrusion. The aluminum tubes produced in this way have a relatively high hardness (e.g., 40 HV 0.01), which is generally too high for further processing and subsequent use. The cold-formed aluminum tubes are therefore soft-annealed in a tube annealing furnace at a temperature of several hundred degrees Celsius. This soft-annealing process causes the aluminum atoms in the aluminum tubes to recrystallize, thus reducing the material's hardness. Important factors influencing the recrystallization process are temperature and time.

[0004] Conventional tube annealing furnaces comprise a large chamber heated by a burner, through which the tubes are transported by conveyor chains. The tubes rest on transport trays attached to the chains. One disadvantage of such furnaces is that the chains must be relubricated approximately weekly with graphite-containing lubricants, which can result in production interruptions of several hours. Furthermore, the entire interior of the tube annealing furnace must be heated to the operating temperature of several hundred degrees Celsius, which is relatively energy-intensive. Such tube annealing furnaces therefore have relatively poor energy efficiency.

[0005] DE 10 2012 109 436 B4 discloses a tube annealing furnace comprising a hollow cylindrical furnace body. A tube, i.e., a tube blank, is stored horizontally in the circular cylindrical cavity of the furnace body, forming a chamber, so that it is in contact with the inside of the furnace body wall. An electrical heating device, such as a heating coil, is located in the wall of the hollow cylindrical furnace body. Heat generated by the heating device is transferred to the tube by conduction, so that it is soft-annealed while lying in the furnace body.

[0006] The invention is based on the object of providing a furnace arrangement of the type mentioned above which has high functionality and energy efficiency.

[0007] To achieve this object, the features of claim 1 are provided. Advantageous embodiments and expedient developments of the invention are described in the dependent claims.

[0008] The invention relates to a furnace arrangement with a tube annealing furnace. The tube annealing furnace has tube receptacles in which tubes are individually stored. Heat generated by a heating device is transferred by thermal conduction to the tubes stored in the tube receptacles. The tube annealing furnace has a modular arrangement of furnace modules, wherein the or each furnace module has a module body made of thermally conductive material, in which at least one tube receptacle for a tube and at least one receptacle, spaced from the tube receptacle, for an electrical heating element is present. The heat generated by the electrical heating element is transferred by thermal conduction via the module body to the tube stored in the tube receptacle, wherein the or each furnace module is surrounded at least in sections by a thermally insulating material.

[0009] The tube annealing furnace according to the invention has a modular design. The tube annealing furnace comprises a modular arrangement of furnace modules.

[0010] Each furnace module comprises at least one tube holder, in which a tube holder can be stored, and a holder for an electric heating element. The furnace module has a module body made of heat-conducting material, in which the tube holder and the holder are located.

[0011] The electric heating element of a furnace module is used to soft anneal the tubes contained within this furnace module. Annealing occurs through thermal conduction. The tube(s) in the tube holder are in thermal contact with the module body, so that the heat generated by the electric heating element is transferred to the tube by conduction via the module body, enabling energy-efficient soft annealing of the tube(s) in the furnace module.

[0012] The furnace module is dimensioned, particularly with regard to the number and positioning of tube holders and holders with electrical heating elements, in such a way that an optimized heat transfer and uniform heat distribution within the furnace module is achieved, so that all tubes present there are soft-annealed with short annealing times.

[0013] For this purpose, it is particularly advantageous if, in a furnace module, the longitudinal axes of each tube holder and each holder run parallel and at a distance from one another.

[0014] The furnace module is thus designed to be uniform in its longitudinal direction, ensuring uniform annealing of the tubes over the entire length of the tube holders.

[0015] Another advantage is that the furnace module is dimensioned in such a way that the thermal expansion of the furnace module is minimized during the annealing processes.

[0016] Another key aspect of the invention is that each furnace module is at least partially surrounded by a heat-insulating material. This ensures that each furnace module is thermally insulated from its surroundings.

[0017] In particular, adjacent furnace modules are separated by the heat-insulating material.

[0018] The heat-insulated furnace modules form energy-autonomous units, meaning that the electrical heating element(s) of a furnace module are used to heat only that particular furnace module for annealing. The furnace modules can then be individually optimized for the specific annealing processes.

[0019] A further advantage is that thermal expansion of individual furnace modules is not transmitted to the surrounding area, especially to neighboring furnace modules, thanks to the thermally insulating materials placed between them. This minimizes material stresses caused by thermal expansion for the entire tube annealing furnace.

[0020] Advantageously, the furnace modules of the module arrangement are stored in a furnace block of the tube annealing furnace.

[0021] The furnace block itself can also be made of a heat-insulating material surrounded by a sheet metal casing or the like.

[0022] Due to the modular design, the tube annealing furnace according to the invention is easily scalable, i.e. the size of the tube annealing furnace can be easily specified by the number of furnace modules.

[0023] Particularly advantageously, the tube annealing furnace has a multiple arrangement of identically designed furnace modules.

[0024] This means that the tube annealing furnace can be constructed from only one type of furnace module in a cost-effective manner.

[0025] A particularly efficient design provides that one or each oven module has only one electrical heating element.

[0026] One or each furnace module has several tube holders.

[0027] Because there is only one electrical heating element in the oven module, the heating output within the oven module is limited, so that undesirable thermal expansion of the oven module is largely avoided.

[0028] In the simplest case, only one tube holder can be assigned to the electrical heating element in the furnace module, so that only one tube is heated and annealed in the furnace module.

[0029] Particularly advantageously, one or each oven module has a holder for an electric heating element and two tube holders.

[0030] This allows two tubes to be heated and annealed simultaneously in the furnace module using the electric heating element.

[0031] It is particularly advantageous to have the tube holders arranged on both sides of the holder for the electric heating element.

[0032] Due to the central arrangement of the electrical heating element, the heat generated in it is fed directly to the two tubes in the tube holders by heat conduction via the module body.

[0033] According to a geometrically advantageous embodiment, the furnace modules of the module arrangement form a row arrangement.

[0034] In the event that each furnace module has two tube holders arranged one above the other with an electric heating element in between, the row arrangement of the furnace modules forms two parallel rows of tube holders running at a distance from one another.

[0035] If there is a precise adaptation of the outer contour of the tubes and the associated tube holder, a tube is mounted in a tube holder with little play and at least in point contact with the module body.

[0036] In this case, a heat-conducting transition occurs from the module body directly to the tube.

[0037] If the outer contour of the tube is considerably narrower than the cross-section of the tube holder, the tube is accommodated in a plug-in sleeve made of heat-conducting material, whereby the plug-in sleeve is mounted in a tube holder with little play and in contact with the module body.

[0038] The plug-in sleeve inserted into the tube holder then ensures a heat-conducting transition from the module body to the tube.

[0039] It is particularly advantageous that the module bodies are made of steel.

[0040] Another advantage is that the heat-insulating material is made of insulating panels.

[0041] According to an advantageous embodiment, the or each electrical heating element is formed by a heating cartridge.

[0042] Advantageously, the tube holders in each furnace module are circular cylindrical, with the front sides of the tube holders being open.

[0043] The circular cylindrical shape represents an optimal geometric adaptation of the tube holder to the geometry of the tubes, which in the form of tube blanks also have rotationally symmetrical shapes.

[0044] The open front sides of the tube holders enable automated feeding of tubes into the tube holders and automated removal of tubes from the tube holders.

[0045] For this purpose, the furnace arrangement advantageously has two conveyor systems, wherein a first conveyor system carries out an automated feeding of tubes into tube receptacles, and a second conveyor system carries out an automated removal of tubes from tube receptacles.

[0046] The two conveyor systems can be independent of each other or form linked units.

[0047] Advantageously, each conveyor system comprises a conveyor belt on which tubes are transported and an arrangement of plungers performing linear movements.

[0048] The plungers allow tubes to be simultaneously inserted into or removed from the tube receptacles. Each plunger pushes a tube into or out of a tube receptacle.

[0049] For this purpose, the rams perform linear movements in the direction of their longitudinal axes.

[0050] The number and arrangement of the rams of both conveying systems is adapted to the arrangement of the tube receptacles of the tube annealing furnace so that the rams simultaneously insert tubes into and remove them from the tube receptacles.

[0051] This allows the tubes to be fed in and out quickly and efficiently.

[0052] The conveyor belt of the first conveyor system is used to deliver tubes to target positions so that the tubes in the target positions can be pushed into the tube holders using the pushers.

[0053] In the second conveyor system, tubes present in the tube annealing furnace are pushed onto the conveyor belt with the rams after soft annealing and then transported to further processing stations.

[0054] The invention is explained below with reference to the drawings. They show: Fig. 1: Schematic representation of a tube annealing furnace of the furnace arrangement according to the invention. Fig. 2: Individual representation of a furnace module of the tube annealing furnace according to Fig. 1. Fig. 3: Sectional view of the furnace module of the tube annealing furnace according to Fig. 2. Fig. 4a: Schematic representation of the tube annealing furnace according to Fig. 1 with a first conveyor system. Fig. 4b: Sectional view of a detail of the arrangement according to Fig. 4a. Fig. 5a: Schematic representation of the tube annealing furnace according to Fig. 1 with a second conveyor system. Fig. 5b: Sectional view of a detail of the arrangement according to Fig. 5a.

[0055] Fig. 1 shows schematically an embodiment of a tube annealing furnace 1.

[0056] The tube annealing furnace 1 is used for soft annealing tubes 2, in particular aluminum tubes, which are in the form of tube blanks, as shown schematically in the Fig. 4a, Fig. 4b and Fig. 5a, Fig. 5b.

[0057] The tube annealing furnace 1 is part of a furnace arrangement 100, wherein the Fig. 4a, Fig. 4b and Fig. 5a, Fig. 5b shows the tube annealing furnace 1 with further components of the furnace arrangement 100.

[0058] As from Fig. 1, the tube annealing furnace 1 has a furnace block 3 in which a module arrangement 4 of several furnace modules 5 is mounted.

[0059] The furnace block 3 has a solid core 6 surrounding the module arrangement 4. The core 6 is made of heat-insulating material, in particular insulating panels. The core 6 is encased in a sheet metal casing 7.

[0060] In the present case, the tube annealing furnace 1 has sixteen identically designed furnace modules 5, which is not mandatory. The number of furnace modules 5 can vary. Different furnace modules 5 can also be provided to form the module arrangement 4.

[0061] In the present case, the furnace modules 5 form a series arrangement, ie, a linear arrangement extending in the longitudinal direction of the tube annealing furnace 1. This configuration is also not mandatory. Other arrangements of furnace modules 5, such as matrix-like arrangements, may also be provided.

[0062] The individual furnace modules 5 are spaced apart from one another, with heat-insulating material being present between adjacent furnace modules 5.

[0063] The Fig. 2 and Fig. 3 show a furnace module 5 in a single view.

[0064] The furnace module 5 has a module body 8 made of heat-conducting material, which in this case is made of steel. The furnace module 5 contains two tube receptacles 9, which are identically designed and are formed as circular-cylindrical openings in the module body 8, which are open at their ends.

[0065] The tube receptacles 9 are arranged one above the other at a distance from one another, with their longitudinal axes running parallel to one another in the longitudinal direction of the furnace module 5.

[0066] The furnace module 5 contains an electric heating element in the form of a heating cartridge 10. The electric heating element is mounted in a receptacle of the module body 8 without play, so that the electric heating element is in heat-conducting contact with the module body 8.

[0067] The heating cartridge 10 is arranged between the tube receptacles 9, with the longitudinal axis of the heating cartridge 10 running parallel to the longitudinal axes of the tube receptacles 9. The tube receptacles 9 and the heating cartridge 10 form a mirror-symmetrical arrangement with respect to the horizontal plane of symmetry of the furnace module 5. Fig. 3 shows a cable 11 as an electrical connection of the heating cartridge 10.

[0068] In general, the oven module 5 can also have a different arrangement and number of electrical heating elements and tube holders 9.

[0069] Due to the series arrangement of the furnace module 5 in the tube annealing furnace 1, as can be seen Fig. 1, two parallel, spaced-apart, superimposed row arrangements of tube receptacles 9 are obtained, each of which can be equipped with a tube 2.

[0070] For annealing the tubes 2, heat generated in the heating cartridge 10 is transferred via the module body 8 by heat conduction to the respective tube 2 in the tube holder 9.

[0071] According to a first configuration, the diameter of the tube receptacles 9 can be adapted to the outer contours of the tube 2, so that the tube 2 has little play and is partially in contact with the wall of the module body 8 delimiting the tube receptacle 9. In this Fig. In the configuration shown in Figure 2, heat generated by the heating cartridge 10 is transferred via the module body 8 directly to the tube 2 by heat conduction.

[0072] If the outer contour of the tube 2 is smaller than the diameter of the tube receptacle 9, a plug-in sleeve 12 is inserted into the tube receptacle 9 in a second configuration ( Fig. 3). The plug-in sleeve 12 is made of a heat-conducting material, e.g., steel. The outer diameter of the plug-in sleeve 12 is adapted to the diameter of the tube receptacle 9, so that the plug-in sleeve 12 is in contact with the wall of the module body 8 surrounding the tube receptacle 9.

[0073] The inner diameter of the plug-in sleeve 12 is adapted to the outer contour of the respective tube 2 in an application-specific manner, so that the tube 2 has little play and is partially in contact with the plug-in sleeve 12. In this case, heat generated by the heating cartridge 10 is transferred to the tube 2 by thermal conduction via the module body 8 and the plug-in sleeve 12.

[0074] The supply of tubes 2 into the tube holders 9 of the oven module 5 is automated by means of a first conveyor system 13, which is Fig. 4a, Fig. 4b. The removal of tubes 2 from the tube holders 9 of the furnace module 5 is automated by a second conveyor system 14, which is Fig. 5a, Fig. 5b is shown.

[0075] The first conveyor system 13 comprises a conveyor belt 15 for delivering tubes 2 to the tube annealing furnace 1. Furthermore, the first conveyor system 13 comprises an arrangement of identically designed rams 16 arranged in the region of the conveyor belt 15. By means of a drive (not shown), the rams 16 can simultaneously perform adjusting movements in the direction of their longitudinal axes. The number of rams 16 corresponds to the number of tube receptacles 9 in a row of the module arrangement 4 according to Fig. 1. The distances between the plungers 16 correspond to the distances between the tube holders 9 in a row.

[0076] With the conveyor belt 15, as shown in Fig. 4a, tubes 2 are delivered so that they are located in target positions in front of a tube holder 9 of a row of tube holders 9.

[0077] By adjusting movements of the plungers 16, the plungers 16 push a tube 2 into the associated tube holder 9, as Fig. 4b shows. Fig. Figure 4b shows the shape of the tube 2, i.e., the tube blank. The tube 2 has a circular-cylindrical hollow body 2a, which has a thread 2b on its front side and is open on its back side.

[0078] The respective plunger 16 engages the open back of the tube 2 and pushes it into the tube holder 9.

[0079] As from Fig. As can be seen in Figure 4b, in the illustrated case, the upper row of tube holders 9 of the module arrangement 4 is equipped with tubes 2. By adjusting the height of the tube annealing furnace 1 (not shown), the lower row of tube holders 9 can then also be equipped with tubes 2.

[0080] The second conveyor system 14 comprises, analogously to the first conveyor system 13, a conveyor belt 17 and an arrangement of rams 18. The second conveyor system 14 differs from the first conveyor system 13 only in that the conveyor belt 17 and the rams 18 are arranged on opposite sides of the tube annealing furnace 1 ( Fig. 5a).

[0081] After the soft annealing of the tubes 2 in the tube annealing furnace 1, the tubes 2 are simultaneously pushed out of the tube receptacles 9 of a row of the module arrangement 4 by means of the pushers 18 and placed on the conveyor belt 17, with which the tubes 2 are transported away.

[0082] How Fig. As shown in Figure 5b, the plungers 18 engage the threads 2b of the tubes 2 in order to push them out of the tube receptacles 9.

[0083] In the Fig. In the case shown in Figure 5b, the tubes 2 are pushed out of the upper row of tube receptacles 9.

[0084] By adjusting the height of the tube annealing furnace 1, the tubes 2 can also be pushed out of the lower row using the push rods 18.

[0085] By adjusting the height, the tube annealing furnace 1 is placed optionally on the first conveyor system 13 or the second conveyor system 14, depending on whether tubes 2 are to be fed into the tube holders 9 or whether tubes 2 are to be pushed out of the tube holders 9. List of reference symbols 1 tube annealing furnace 2 tubes 2a Hollow body 2b thread 3 furnace block 4 Module arrangement 5 Oven module 6 core 7 Sheet metal cladding 8 module bodies 9 Tube holder 10 heating cartridges 11 cables 12 plug-in sleeves 13 first conveyor system 14 second conveyor system 15 Conveyor belt 16 tappets 17 Conveyor belt 18 tappets 100 furnace arrangement QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2012 109 436 B4

[0005]

Claims

[1] Furnace arrangement (100) with a tube annealing furnace (1) which has tube receptacles (9) in which tubes (2) are individually stored, wherein heat generated by a heating device is transferred by heat conduction to the tubes (2) stored in the tube receptacles (9), characterized by in that the tube annealing furnace (1) has a module arrangement (4) of furnace modules (5), wherein the or each furnace module (5) has a module body (8) made of thermally conductive material, in which there is at least one tube receptacle (9) for a tube (2) and at least one receptacle, spaced from the tube receptacle (9), for an electrical heating element, wherein heat generated by the latter is transferred by thermal conduction via the module body (8) to the tube (2) mounted in the tube receptacle (9), and wherein the or each furnace module (5) is surrounded at least in sections by a thermally insulating material. [2] Furnace arrangement (100) according to claim 1, characterized bythat the tube annealing furnace (1) has a multiple arrangement of identically designed furnace modules (5). [3] Furnace arrangement (100) according to one of claims 1 or 2, characterized by that adjacent furnace modules (5) are separated by the heat-insulating material. [4] Furnace arrangement (100) according to one of claims 1 to 3, characterized by that the furnace modules (5) of the module arrangement (4) are mounted in a furnace block (3) of the tube annealing furnace (1). [5] Furnace arrangement (100) according to one of claims 1 to 4, characterized by that in a furnace module (5) the longitudinal axes of each tube holder (9) and each holder run parallel and spaced from one another. [6] Furnace arrangement (100) according to one of claims 1 to 5, characterized by that one or each oven module (5) has only one electric heating element. [7] Furnace arrangement (100) according to one of claims 1 to 6, characterized by that one or each furnace module (5) has several tube receptacles (9). [8] Furnace arrangement (100) according to one of claims 1 to 7, characterized by that one or each oven module (5) has a receptacle for an electric heating element and two tube receptacles (9). [9] Furnace arrangement (100) according to claim 8, characterized by that the tube receptacles (9) are arranged on both sides of the receptacle for the electric heating element. [10] Furnace arrangement (100) according to one of claims 1 to 9, characterized by that the furnace modules (5) of the module arrangement (4) form a series arrangement. [11] Furnace arrangement (100) according to one of claims 9 and 10, characterized by that the row arrangement of the furnace modules (5) forms two parallel rows of tube holders (9) spaced apart from one another. [12] Furnace arrangement (100) according to one of claims 1 to 11, characterized by that a tube (2) is mounted in a tube holder (9) with little play and at least in point contact with the module body (8). [13] Furnace arrangement (100) according to one of claims 1 to 11, characterized by that a tube (2) is accommodated in a plug-in sleeve (12) made of heat-conducting material, wherein the plug-in sleeve (12) is mounted in a tube receptacle (9) which is connected to the module body (8) in a heat-conducting manner, and that a tube (2) is mounted in the plug-in sleeve (12) and is in contact with it with little play and at least at certain points. [14] Furnace arrangement (100) according to one of claims 1 to 13, characterized by that the module bodies (8) are made of steel. [15] Furnace arrangement (100) according to one of claims 1 to 14, characterized by that the heat-insulating material is formed by insulating panels. [16] Furnace arrangement (100) according to one of claims 1 to 15, characterized by that the or each electrical heating element is formed by a heating cartridge. [17] Furnace arrangement (100) according to one of claims 1 to 16, characterized bythat the tube receptacles (9) are circular-cylindrical, with the end faces of the tube receptacles (9) being open. [18] Furnace arrangement (100) according to one of claims 1 to 17, characterized by in that it has two conveyor systems (13, 14), wherein a first conveyor system (13) carries out an automated feeding of tubes (2) into tube receptacles (9), and wherein a second conveyor system (14) carries out an automated removal of tubes (2) from tube receptacles (9). [19] Furnace arrangement (100) according to claim 18, characterized by that each conveyor system (13, 14) has a conveyor belt (15, 17) on which tubes (2) are transported, and an arrangement of plungers (16, 18) performing linear movements. [20] Furnace arrangement (100) according to claim 18, characterized bythat tubes (2) are pushed into tube receptacles (9) with the pushers (16) of the first conveyor system (13), and that tubes (2) are pushed out of the tube receptacles (9) with the pushers (18) of the second conveyor system (14).

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