EP2531624B1 - Device and method for heat-treating steel wires - Google Patents

Description

The invention relates to a furnace for heat treating at least one elongated, in particular metallic object such as one or more wires, in particular steel wires, in a continuous process, comprising a furnace inlet and a furnace outlet and one or more furnace sections which extend between the furnace inlet and the furnace outlet and form a first shaft , wherein in the furnace, in particular in the first shaft, one or more heating elements are arranged for setting a temperature in the one or more furnace sections, and wherein the elongated, in particular metallic object can be transported along the first shaft, at least a second one with the first shaft connected shaft and at least one fan is provided with which an atmosphere in the furnace can be circulated in a circuit along the first shaft and the second shaft.

Furthermore, the invention relates to a device with such an oven and a module for the heat treatment of at least one elongated, in particular metallic object such as one or more wires, in particular steel wires, in a continuous process, the module having a module inlet and a module outlet and in between a water bath and subsequently has a stop section with one or more heating devices.

Finally, the invention relates to a process for the heat treatment of at least one elongated metallic object, such as one or more wires, in particular steel wires, in a continuous process, the metallic object being passed through an oven and an adjoining module with a water bath and a holding section in order to ensure a structure of the adjust metallic object, wherein an atmosphere in the furnace (1) is continuously circulated in a circuit.

It is known from the prior art to use devices for the heat treatment of one or more elongated metallic objects, in particular one or more wires such as steel wires, in a continuous process. In this context, continuous process means that the at least one elongated metallic object, for example a metallic wire such as a steel wire or a metallic strip such as a steel strip, is drawn off from an unwinding device and by a device for Heat treatment is performed. In the heat treatment, it can be intended, in particular, that the elongated metallic object to be treated is transferred into a structure that is possibly particularly suitable for further processing. For steel wires, for example, it is known to carry out a heat treatment in order to obtain steel wires with a pearlitic structure, in particular for high-carbon steel wires with a carbon content of approximately more than 0.5 to 1.0 percent by weight. In this regard, a steel wire is first passed through a furnace for austenitizing the steel wire and then quenched in a module separate from the furnace to a temperature in the region of the pearlite nose of the structure before the steel wire is kept at a temperature of about 550 ° C. to convert the Structure in perlite without ensuring the formation of martensite ( EP 0 524 689 A1 or EP 0 216 434 A1 ).

In GB 491 052 A discloses an oven with a subsequent water bath for the heat treatment of long metal products. In BE 834 316 A1 discloses a furnace for the heat treatment of long metal products, in which an atmosphere is circulated through an upper shaft and into a lower shaft.

Furnaces for the austenitization of a steel wire generally have a plurality of heating elements, for example in the form of gas burners, with which a wire, in particular steel wire, and optionally also a plurality of bundles of steel wires guided in parallel, are heated to or above an austenitization temperature, so that a subsequent setting of the Structure can be done in the manner described above.

From the EP 0 524 689 A1 A combination of a furnace for austenitizing and an adjoining module for quenching or adjusting a structure of a steel wire has become known, but in particular with large dimensions of a steel wire, several water baths, which are alternatively connected with air cooling zones, must be provided.

Furnaces for the austenitization of steel wires or other elongated metallic objects have the disadvantage, among other things, that the furnaces are relatively long and therefore require a large amount of space.

Similarly, modules that are used in connection with furnaces for the austenitization of steel wires, for example, have the disadvantage that, particularly with large wire diameters, several water baths must be provided, which can be switched alternately with air cooling zones, which also requires a large overall length or a considerable space requirement required.

It also follows from the disadvantages of the prior art that a device which comprises a combination of a furnace for austenitizing, for example, one or more steel wires and a downstream module for the purpose of adjusting the structure requires a considerable amount of space.

Appropriate disadvantages also have methods of the type mentioned.

The object of the invention is to provide a furnace of the type mentioned, which is shorter than the stoves specified in the prior art and with which an elongated, in particular metallic object such as a steel wire can be heated to austenitizing temperature or another temperature in a simple manner.

Another object of the invention is to provide a device with such a furnace and a module, which enables the setting of a desired structure, for example of a steel wire, over a short distance, if this has previously been heated to or above an austenitizing temperature.

Finally, it is an object of the invention to provide a method of the type mentioned at the outset with which a desired structure can be set along a comparatively short distance.

The object is achieved according to the invention in that control loops are provided for setting the temperature in the oven sections in an oven of the type mentioned at the outset.

An advantage achieved with an oven according to the invention can be seen in particular in the fact that it can be used in a short construction. The first shaft and the second shaft together form a circuit along which the fan provided atmosphere or circulating air in the furnace can be continuously circulated. For example, in the case of heat treatment of steel wires, the atmosphere can be conducted in cocurrent or countercurrent over the steel wires, for example at a speed of 15 to 25 ms ^-1 , which leads to a large amount of convection. Because of the convection, there is good heat transfer and therefore rapid heating of an elongated metallic object passed through the furnace. This results in a shorter treatment distance and therefore shorter construction than is the case with an oven without recirculation of the atmosphere. The circulation also results in better controllability in part-load operation and the atmosphere in the furnace is independent of the load.

Basically, it is provided that the furnace has several furnace sections in which the temperatures can be set separately. The background is that, for example, in the case of heat treatment of steel wires, the steel wires in the area of the furnace inlet are cold and therefore a higher temperature is required in the first furnace section than in the subsequent furnace sections, in which the steel wire is basically already warm and only ensures a homogeneous temperature distribution in it shall be. In this regard, control loops for temperature adjustment are provided in the furnace sections according to the invention. This allows an optimal temperature profile to be set in the furnace or along the individual furnace sections. With regard to setting a temperature profile, it proves expedient in many cases that two to ten, in particular two to six, furnace sections are provided.

The heating element or elements can be provided in the first and / or second shaft. As a rule, it is expedient for efficient heating and targeted setting of temperatures to arrange the heating element or elements in the first shaft.

A furnace according to the invention is preferably used in the patenting of steel wires for heating the steel wires to or above an austenitizing temperature, but can also be used in other heat treatment processes such as tempering, diffusing or stress-relieving, where appropriate Additional devices are connected downstream, for. B. a module with a coolant or a water bath when tempering.

The at least one fan can in principle be positioned at any position of the furnace. It is preferably provided that the fan is arranged closer to the kiln outlet than to the kiln inlet because circulation of the atmosphere in the kiln is usually circulated counter to a transport direction of a material to be treated or in countercurrent and a temperature load for the fan in the region of the kiln outlet is less than in the area of the stove inlet. It is also possible that several fans with several partial circles are provided for circulating the atmosphere. It is also advantageous if an oxidizing or reducing gas can be supplied in each pitch circle via provided feed lines, so that a process-dependent atmosphere can be maintained.

Any heating elements can be provided as heating elements, e.g. B. electric heating elements. The heating elements are usually arranged along the first shaft. In particular, the heating elements can be gas burners with which hot combustion gas can be fed in normally or transversely to the transport direction of the material to be treated. While the energy supply in the first shaft takes place at different positions transversely to the elongated object, convection is improved by the circulation of the atmosphere at a higher speed of, for example, 15 to 25 ms ^-1 , so that overall the material to be treated is rapidly heated. If gas burners are provided, the furnace can have at least one exhaust air outlet through which excess furnace exhaust air can escape.

If gas burners are provided, they are preferably recuperation burners, waste heat from the furnace being usable for heating combustion gases, and preferably the combustion air supplied to the recuperation burners is preheated to 130 ° C. to 250 ° C. Alternatively, cold air burners or warm air burners with central preheating can also be provided.

If gas burners are provided, the furnace advantageously has a device for measuring a calorific value of a (combustible) gas used and a regulating unit for regulating a volume flow of combustion air supplied to the gas burners. The combustible gases supplied or supplied to the gas burners can have different qualities, which can lead to a locally different atmosphere in the furnace. This is usually not desirable and is avoided by this device.

In order to achieve good convection of the circulated atmosphere in relation to the material carried through, it can also be provided that the first shaft has indentations for deflecting the circulated atmosphere. As a result, the atmosphere in the furnace is not only circulated, for example, in countercurrent to the good being carried out, but also there is occasional cross-flow of the good being carried out, which favors rapid heating of the good and thus ultimately a short construction of the furnace. Instead of the indentations, means having the same or a similar effect can also be provided. It is possible, for example, to design the first shaft at the top and bottom in cross section with straight side walls, but to arrange deflecting plates at one or more positions which, like the indentations, ensure that the circulated atmosphere is deflected towards the moving or carried-through material. In general, any means for redirecting the recirculated atmosphere are suitable.

With regard to the indentations, it would in principle be optimal if they were to have an angle of approximately 90 ° on the inflow side, but this is not practical in view of the simultaneous circulation of the atmosphere, for example in direct current. However, the desired effects can already be achieved in a practical manner if the indentations on the inflow side have an angle of approximately 30 ° to 60 °. The same applies if, instead of the indentations, agents having the same or a similar effect are provided.

In view of a not only short but also low construction, it is particularly preferred if the first shaft runs horizontally and the at least one second shaft is arranged directly below the first shaft. It goes without saying that the two shafts, insofar as they are not directly connected, by one intermediate element are separated so that a circulation of the atmosphere in a circuit is possible. For example, the two shafts can be largely separated from one another by ceramic plates located between them. Such a construction also offers advantages in terms of efficient heat management when operating the furnace.

The furnace is preferably designed such that the first shaft and the at least one second shaft merge into one another in the region of the furnace inlet and the furnace outlet, so that the atmosphere in the furnace can be circulated. In the other areas, the shafts are separated from one another as mentioned. With such a design, the convection effect achieved by the circulation of the atmosphere can be used throughout the furnace. For this reason, at least the first shaft should extend at least over 65%, preferably at least over 75%, of the length of the furnace. If the furnace is used for diffusion processes, however, it may be advisable that at least the first shaft does not extend to the furnace outlet but ends beforehand, so that a holding zone with heating elements for subsequent heat treatment can be integrated between one end of the first shaft and the furnace outlet.

In view of an efficient heat balance or a low energy expenditure during the operation of the furnace and any further devices connected downstream, one or more heat exchangers are preferably provided for utilizing waste heat from the furnace and the recuperation burner. The waste heat can be used, for example, to heat drying ovens. As an alternative to using the heat content of exhaust gas or flue gas for external systems such as e.g. B. bathroom heaters or heat chambers, the gas burners, in particular recuperation burners, fresh air supplied can be preheated by means of heat exchangers from the flue gas, for. B. by guiding an acid-resistant supply air duct made of stainless steel in an exhaust air outlet or chimney. This reduces thermal furnace losses to heat losses over a housing surface of the furnace to the surrounding space and a product of the amount of exhaust gas or flue gas times the difference between a required minimum smoke temperature at the chimney outlet and less the supply air temperature times the specific heat. A combination of external and internal use of the flue gas via heat exchange surfaces is also possible. Since a gas / air mixture also in partial load operation in the composition remains constant, the ratio of the amount of exhaust gas to the amount of supply air is constant and there are only slight shifts in the combustion air temperature and the chimney outlet temperature from the changed flue gas temperature and the heating surface load on the heat exchanger surface due to the lower flow rate.

An oven according to the invention can, for example, be completely or exclusively bricked. However, it is preferred that the furnace is only bricked up to a certain height, but is formed on the head side with a detachably fastened cladding. This makes it possible to open the furnace in the event of faults or service or maintenance work and to carry it out inside the same work without major problems. In this case, removable insulation is arranged underneath the detachably fastened cladding, so that the furnace is well insulated from the environment, similar to a brick-only furnace.

The further object of the invention is achieved by a device with an oven and a module of the type mentioned at the beginning, in which the length of the water bath can be variably adjusted and the holding distance to the water bath can be correspondingly extended or shortened.

An advantage achieved with such a device can be seen in the fact that it can be made relatively short and nevertheless a desired structure can be set, for example when patenting steel wires with a diameter of up to 10 mm. The module also offers great flexibility, since the length of the water bath can be variably adjusted so that the dimensions of a good to be treated can be taken into account or a desired cooling can be set based on an austenitizing temperature. Even with larger dimensions of steel wires, it has proven to be sufficient if only a single water bath is provided, which is followed by a stop section in which the material to be treated is kept at a certain temperature in order to complete the structural change. The stop distance can be extended or shortened corresponding to the water bath, so that the material to be treated can always be guided in a defined atmosphere after exiting the water bath. The water bath is suitably elongated. With regard to, for example, the patenting of steel wires, the water bath advantageously has a plurality of parallel sections which can be variably adjusted in length separately. The stop section is then formed with correspondingly extendable or shortenable sections. This makes it possible, for example, for several bundles of steel wires of different dimensions to be passed through the module in parallel for the purpose of heat treatment, without having to forego the advantages set out above.

In order to be able to specifically set and maintain conditions in the water bath, a plurality of supply lines and, if appropriate, at least one discharge line for setting a cooling medium can be provided along the length of the water bath or the sections thereof.

It is advantageous that the module is completed and the length of the water bath or the sections thereof can be adjusted, in particular, manually and / or automatically from the outside. When changing the dimensions of the material to be treated, this allows the length of the water bath to be adapted accordingly.

It can be provided that the length of the water bath or the sections thereof can be adjusted continuously or discretely with individual segments, the distance of the segments from the module inlet to the module outlet decreasing in particular logarithmically. As a result, an optimal length of the water bath can be set in a simple manner for almost any dimensions of, for example, steel wires.

An advantage achieved with a device according to the invention can be seen in the fact that it has a short or compact construction and therefore enables, for example, patenting of steel wires over a short distance or generally the setting of a desired structure of a material to be treated.

It is preferably provided that the oven is connected in an airtight manner to the module inlet of the module and its water bath. This ensures that what is to be treated It is good that the furnace leaves the furnace at a relatively high temperature and does not come into contact with an uncontrolled or uncontrollable atmosphere before immersing it in the water bath.

It is furthermore advantageous if a pull-in device with reels and at least one band is provided, the at least one band running through the device and preferably being arranged in a lateral region thereof. Thereby, preference for inserting wires or the like can be easily drawn through the device. The tape, which remains permanently positioned in the device, advantageously consists of a high-temperature resistant alloy.

The further object of the invention is achieved by a method of the type mentioned at the outset if a temperature setting in the furnace sections is carried out in a furnace according to the invention with control circuits.

In a method according to the invention, it is particularly advantageous that good circulation is achieved by circulating the atmosphere in the furnace, so that a good to be treated can be heated to a desired temperature over a relatively short distance before the good is immersed in a water bath.

It is advantageously provided that the atmosphere is circulated at a speed of up to 50 ms ^-1 , preferably 15 to 25 ms ^-1 , in order to achieve the desired convection effect as effectively as possible.

It is advantageously provided that the atmosphere is circulated countercurrent to the transport direction of the elongated metallic object. Nevertheless, it is of course also possible for circulation to be carried out in the direction of transport.

In particular with regard to patenting steel wires, it is preferably provided that the elongated metallic object is guided from the furnace into the module in a controlled atmosphere in order to avoid undesired contact with an uncontrolled or uncontrollable atmosphere.

The elongated metallic object is preferably cooled in a water bath by film boiling, as is known per se from the prior art. A suitable additive is added to the water bath. In this regard, it can be provided that water or additive is metered in via a metering unit and an associated control circuit in order to keep an additive content in the water bath constant or within predetermined limits while maintaining a constant coolant temperature.

• Fig. 1 eine schematische Darstellung eines Ofens in seitlicher Ansicht;
• Fig. 2 einen Querschnitt des Ofens gemäß Fig. 1 normal zu dessen Längsachse;
• Fig. 3 eine weitere Ausführungsvariante eines Ofens;
• Fig. 4 einen Querschnitt des Ofens gemäß Fig. 3 normal zu dessen Längsachse;
• Fig. 5 ein Modul umfassend ein Wasserbad und eine Haltestrecke;
• Fig. 6 eine schematische Darstellung einer Einzieheinrichtung in seitlicher Ansicht;
• Fig. 7 eine schematische Darstellung der Einzieheinrichtung gemäß Fig. 6 in Draufsicht;
• Fig. 8 eine schematische Darstellung eines Ofens.

Further features, advantages and effects of the invention result from the exemplary embodiments presented below. Individual features of the exemplary embodiments, even if they are mentioned in connection with further features, can be combined with the general teaching of the invention explained above. The drawings show:

• Fig. 1 a schematic representation of a furnace in a side view;
• Fig. 2 a cross section of the furnace Fig. 1 normal to its longitudinal axis;
• Fig. 3 another embodiment of a furnace;
• Fig. 4 a cross section of the furnace Fig. 3 normal to its longitudinal axis;
• Fig. 5 a module comprising a water bath and a stopping line;
• Fig. 6 a schematic representation of a retractor in a side view;
• Fig. 7 a schematic representation of the retractor according to Fig. 6 in top view;
• Fig. 8 a schematic representation of an oven.

In Fig. 1 and 2nd A first variant of an oven 1 according to the invention is shown. The furnace 1 is elongated and has a furnace inlet 3 or furnace outlet 4 at the end. The furnace 1 can be part of a device for heat treating, in particular patenting, steel wires. The steel wires are introduced in bundles in the area of the oven inlet 3 and leave the oven 1 in the area of the oven outlet 4. The oven 1 comprises a brick base, which is surrounded on the outside by a housing and carries a structure. The construction includes a further part of the housing as well as insulation elements. How from Fig. 2 can be seen is in the lower part of the furnace 1 a first shaft 8 is formed. A second shaft 9 is formed in the upper part of the furnace 1 or structure. The first shaft 8 and the second shaft 9 run essentially along an entire length of the furnace 1 and parallel to one another. The first shaft 8 and the second shaft 9 are connected to one another in the area of the furnace inlet 3 and the furnace outlet 4, so that an atmosphere in the furnace 1 can be circulated. As a result, steel wires, which are guided through the first shaft 8 for example for the purpose of heating to or above an austenitizing temperature and heated therein by means of heating devices (not shown in more detail), can be brought to the desired temperature along a relatively short distance. As can be seen, the second shaft 9 is constructed and arranged above the first shaft 8. However, it is also possible for the second shaft 9 to be positioned next to the first shaft 8 or to run outside the housing.

In Fig. 3 and 4th a second, preferred variant of a furnace 1 is shown. The oven 1 in turn has an oven inlet 3 and an oven outlet 4. Both the kiln inlet 3 and the kiln outlet 4 are closed or closable by an openable flap, the flaps each having one or more recesses approximately in the center, so that a wire 2 or more bundles of wires 2 can be inserted into and out of the oven 1 can be removed again. The furnace 1 is elongated and has a plurality of furnace sections 5. A plurality of heating elements 6 in the form of gas burners, in particular recuperation burners, are provided in the individual furnace sections 5. The gas burners are fed with a combustible gas and combustion air via a central main gas line. Nevertheless, it is also possible for the individual gas burners to be fed separately. As in summary of the representations in Fig. 3 and 4th can be seen, the furnace 1 is formed with a first shaft 8, along which a wire 2 or one or more bundles of wires 2 can be guided. Suitable wire guides are provided for this. Three further, second shafts 9 are arranged below the first shaft 8. The first shaft 8 is completely separated from the second shafts 9 along a longitudinal axis of the furnace 1 with the exception of end regions, for example in the region of the furnace inlet 3 and the furnace outlet 4. In the area of the kiln inlet 3 and the kiln outlet 4, the first shaft 8 merges into the second shafts 9 via a curve, the curves in the area of one Transport direction R of the wire 2 or possibly one or more bundles of wires 2 guided in parallel are interrupted. The separation of the first shaft 8 from the second shafts 9, which is essentially given in the region of the longitudinal axis, can be carried out in a simple manner by ceramic elements 14 which extend over a width of the first shaft 8. In general, however, a plurality of first shafts 8 can also be provided, which merge into a single second shaft 9 or a plurality of separate second shafts 9. Since the ceramic elements 14 are usually made as thin as possible, a masonry 13 additionally comprises webs, so that the ceramic elements are carried laterally by the masonry 13 and at the same time rest on the webs. This ensures that the ceramic elements 14 can withstand the given mechanical loads even with a thin design. This also leads to the formation with three second shafts 9, although only a second shaft 9 can also be present. It is also possible for the webs to be formed only in sections. The masonry 13 extends over the height of the second shaft 8 and carries components 12, which together with the ceramic elements 14 define the first shaft 8 at least in some areas, and a removable insulation 16. A detachably fastened cladding 15 is arranged above the insulation 16 on the head side . The combination of detachably fastened cladding 15 in the area on the head side and the removable insulation 16 arranged underneath it allows the furnace 1 to be opened from above, for example for service or maintenance work, which is not possible with a brick-only furnace. A fan 7 is arranged in that end region of the furnace 1 which is adjacent to the furnace outlet 4. With the fan 7, an atmosphere located in the furnace 1 can be circulated along the first shaft 8 and the second shafts 9, in countercurrent to the transport direction R, as shown in FIG Fig. 3 is indicated by several arrows. In order to achieve the best possible flow against a material to be heated, the first shaft 8 has indentations 10, so that the atmosphere or circulating air flows in certain directions towards the wire 2 or the wires 2 at an angle. The furnace 1 is not only of short construction, but is also highly energy-efficient, especially since the first shaft 8 is separated from the second shafts 9 only by the ceramic elements 14, which consist for example of cordierite. Since additional gases can be introduced into the first shaft 8 in order to, for. B. adjust the atmosphere or recirculated air, small-sized exhaust outlets 11 are also provided, through which excess recirculated air can be removed so that it there is no undesirable pressure build-up. A temperature can be set in the individual furnace sections 5 by means of provided control loops and regulation of the recuperation burners. In particular, so-called low-load operation is also possible, since sufficient heating of a wire 2 or possibly one or more bundles of wires 2 can be achieved even at low loads through the intended circulation of the circulating air. This is otherwise a major problem when using gas burners, because the already poor heat transfer is throttled even further.

In Fig. 5 A module 17 can be seen, which has a water bath 18 and a holding section 19, the holding section 19 connecting to the water bath 18. The module 17 has a module inlet 20 and a module outlet 21, which are each arranged at the ends. In a device for patenting steel wires, the module inlet 20 directly adjoins the furnace Fig. 3 in such a way that the wire 2 dips from the furnace outlet 4 directly into the water bath 18 of the module 17 without coming into contact with an atmosphere surrounding the device. This ensures that the steel wire which is at the austenitizing temperature is not adversely changed or is not adversely changed before it is immersed in the water bath 18. The water bath 18, which in Fig. 5 as the entire module 17 is only shown schematically, the length can be changed. In this regard, for example, a crank can be provided on the outside, with which a weir can be continuously adjusted. It is also possible for the water bath 18 to be subdivided into individual segments which can be flooded as required or a required length of a cooling section. At the same time, it can also be provided that the water bath 18 has a plurality of sections which can be regulated in parallel and independently of one another, each of the sections being variable in length. The holding section 19 is formed with a plurality of holding zones which can be operated independently of one another and each comprise one or more heating devices. A temperature can be set in each of the individual holding zones by the heating devices, for example in the range from 500 ° C. to 600 ° C., as may be necessary for patenting steel wires. Surprisingly, it has been shown that a single water bath 18 in combination with a holding section 19 with a plurality of temperature-controlled holding zones is sufficient for patenting steel wires with cross sections of at least up to 15 mm ² . So that an exact over the entire length of the module 17 Controllability of the temperature is possible, it is provided that the holding section 19 is designed according to a length adjustability of the water bath 18 with correspondingly extendable or shortenable elements. These elements can be designed, for example, in the form of pull-out panels which also have insulation on the inside. It is also possible that the holding section 19 can be partially or completely telescopically extended at the end adjoining the water bath 18. These constructive measures ensure that the wire 2 can be guided immediately into a temperature-controlled zone when leaving the water bath 18, regardless of its length, without there being an uncontrolled or uncontrollable space.

In 6 and 7 A drawing device 22 is shown, which can be provided in connection with a device from a furnace 1 and a module 17 connected to it, in particular if the device is used for the heat treatment of steel wires. The pull-in device 22 has two reels 23, 24, on each of which a band 25 is rolled up. Both reels 23, 24 are provided with a motor so that the belts 25 can be moved in one direction or the other as required. As mentioned, the entire pull-in device 22 can be an integral part of a device with an oven 1 and an adjoining module 17 with a water bath 18 and a holding section 19. In order not to hinder the guiding of steel wires during operation, the strips 25 of the drawing-in device 22, which run through the furnace 1 and the module 17, are arranged laterally, in particular laterally in the first shaft 8 in a furnace 1 according to FIG Fig. 3 or a module 17 according to Fig. 5 . Since the belts 25 only require a small amount of space, this does not result in a loss of capacity. The tapes 25 are expediently made of a high-temperature alloy to withstand the high temperatures. Basically, the tapes 25 are wound onto the reel 23 as far as possible. Only one end of the tapes 25 is connected to the reel 24. When starting a production, a so-called preference is fastened to the strips 25, with which the wires 2 can ultimately be inserted into the device. For this purpose, the preference must be transported through the entire device by winding the tapes 25 with the preference attached to the reel 24. If the preference is passed through the device, the wires 2 can then be drawn in. In this regard, there is also one equipped with a motor Auxiliary winder 26 is provided, on which wires 2 or wire bundles already carried out can be temporarily wound up. The wires 2 are then kept in motion until they are welded on by the auxiliary winder 26, and disadvantageous wire stoppages in the furnace 1 can be avoided.

In Fig. 8 Another variant of an oven 1 according to the invention is shown in a highly schematic manner. The furnace 1 is designed as a diffusion furnace and has one or more fans 7, preferably two fans 7. With the fans 7, recirculated air is circulated along the first shaft 8 and the two second shafts 9, in countercurrent to a wire 2 which is guided through the furnace 1. Components for heating are arranged in the second shafts 9, preferably electrical or gas-heated heating elements, e.g. B. electric heating register. The furnace 1 is formed on the inlet side with a zone in which the wire 2 that is passed through is exposed vertically to a heating medium, so that the wire 2 is brought to temperature quickly or over a short distance. In the subsequent zone, the wire 2 only needs to be kept at temperature, which is achieved by circulating the atmosphere with the fans 7.

Claims (13)

1. An oven (1) for the heat treatment of at least one oblong, in particular, metallic object, such as one or a plurality of wires (2), in particular, steel wires, using the through-feed method, comprising an oven inlet (3) and an oven outlet (4), as well as a plurality of oven sections (5), which extend between the oven inlet (3) and the oven outlet (4) and form a first shaft (8), wherein, in the oven (1), in particular, in the first shaft (8), one or a plurality of heating elements (6) are respectively arranged for configuring a temperature in the oven sections (5) and wherein the oblong, in particular, metal object can be transported along the first shaft (8), wherein at least one second shaft (9) in connection with the first shaft (8), and at least one fan (7) are provided, with which an atmosphere within the oven (1) can be circulated in the circuit along the first shaft (8) and the second shaft (9), characterized in that control circuits are provided for temperature configuration in the oven sections (5).
2. The oven (1) according to claim 1, characterized in that the fan (7) is arranged closer to the oven outlet (4) than to the oven inlet (3).
3. The oven (1) according to claim 1 or 2, characterized in that a device for measuring a calorific value of a supplied fuel gas is provided and a regulation unit for regulating a volumetric flow of a combustion air supplied to gas burners is provided.
4. The oven (1) according to one of the claims 1 to 3, characterized in that two to ten, in particular, two to six oven sections (5) are provided.
5. The oven (1) according to one of the claims 1 to 4, characterized in that the first shaft (8) has recesses (10) for deflecting the circulated atmosphere.
6. The oven (1) according to one of the claims 1 to 5, characterized in that the first shaft (8) and the at least second shaft (9) merge into one another in the region of the oven inlet (3) and the oven outlet (4).
7. An apparatus with an oven (1) according to one of the claims 1 to 6, and a module (17) for the heat treatment of at least one oblong, in particular, metallic object, such as one or a plurality of wires (2), in particular, steel wires, using the through-feed method, wherein the module (17) has a module inlet (20) and a module outlet (21) as well as, in-between, a water bath (18) and a stop distance (19) adjoining it with one or a plurality of heating devices, characterized in that the length of water bath (18) can be variably configured and the stop distance (19) towards the water bath (18) can be extended or shortened accordingly.
8. The apparatus according claim 7, characterized in that the water bath (18) is oblong and has a plurality of parallel sections, the lengths of which can be variably configured on an individual basis and the stop distance (19) is designed with sections that can be correspondingly extended or shortened.
9. The apparatus according to claim 7 or 8, characterized in that a plurality of supply lines and, if applicable, at least one discharge line are respectively provided along the length of the water bath (18) or the sections of the same for configuring a cooling medium.
10. The apparatus according to claim 9, characterized in that the oven (1) is connected in an air-tight manner to the module inlet (20) of the module (17) and its water bath (18).
11. A method for the heat treatment of at least one oblong metallic object such as one or a plurality of wires (2), in particular, steel wires, using the through-feed method, wherein the metallic object is guided through an oven (1) with oven sections (5) and a module (17) adjoining it with a water bath (18) and a stop distance (19) in order to configure a structure of the metal object, wherein an atmosphere in the oven (1) is continuously circulated in a circuit, characterized in that a temperature configuration is carried out in the oven sections (5) in an oven (1) with control circuits according to one of the claims 1 to 6.
12. The method according to Claim 11, characterized in that the atmosphere is recirculated at a speed of up to 50 ms^-1, preferably 15 to 25 ms^-1.
13. The method according to Claim 11 or 12, characterized in that the atmosphere is circulated in countercurrent to a transport direction (R) of the oblong metallic object.

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