DEVICE AND METHOD FOR HEAT TREATMENT OF A FLAT PRODUCT

Description

[0001] The invention relates to a device and a method for heat-treating a flat product, in particular a strip-shaped sheet of metal, in a nozzle device comprising a first nozzle system and a second nozzle system, wherein at least one gas jet emerges from at least one gas outlet opening in each nozzle system, wherein the gas jet exiting from the gas outlet opening in the first nozzle system is directed towards the front of the flat product and the gas jet exiting from the gas outlet opening in the second nozzle system is directed towards the back of the flat product, and wherein the flat product is guided through the nozzle device in the direction of travel by means of conveying means during the heat treatment.

[0002] A flat product is understood to be a sheet-like item that can be made of any material, especially metal, and is typically heat-treated in a continuous process. Heat treatment refers to cooling or heating.

[0003] One important application is the heating or cooling of strip-shaped sheets, bands or other flat products made of steel or other metals, such as aluminium, using technical gases such as air, N2, H2 or gas mixtures.

[0004] During convective heating or cooling using gases, a strip of sheet metal is continuously transported through the nozzle assembly by means of conveying devices, usually pairs of rollers between which the sheet is guided. Heat treatment of sheet metal for cooling purposes is preceded by heating, particularly in annealing processes to achieve defined material properties. Industrial furnaces are used for annealing steel sheets or strips. The sheets are heated in an industrial furnace and then rapidly cooled or quenched in the continuous cooling direction. This rapid cooling serves to create a specific microstructure or to transform the microstructure of the sheet metal. To achieve high cooling rates, liquid coolants, usually water, are typically used under increased pressure.

[0005] When annealing very thin metal strips with typical thicknesses of 1 mm to 2 mm made of high-performance or multi-phase steels, very high cooling rates of 100 K / s or more are sometimes required. Because of the heat transfer required for this, water baths, cooling rollers, or water spray cooling are used in practice. A disadvantage of these methods is the contamination of the sheet surface due to mechanical contact between the sheet and the cooling rollers, or the unwanted contamination of the sheet surface with the liquid cooling medium.

[0006] The convective heat treatment of sheet metal with technical gases in a continuous process using nozzles, gas nozzle systems, or nozzle arrays directed at the front and back of the sheet metal is known in practice. For example, the nozzle system can have a slot-shaped outlet opening for the gas that extends across the entire width of the nozzle system. Nozzle systems with a multitude of nozzle outlet openings are also known.

[0007] US Patent 6,309,483 B1 discloses a system and method for preventing belt vibrations in the gas injection zones, particularly in the cooling zones. In the known method, in a zone located at one edge of the belt, the pressure and / or flow velocity of the cooling gas on one side of the belt is set to a value lower than the nominal value. On the opposite side of the belt, the pressure and / or flow velocity of the cooling gas is set to a value lower than the nominal value, so that the belt is subjected to an asymmetric force field, which gives the belt an equilibrium position with a torsional angle.

[0008] US patent 2014 / 0158234 A1 discloses a device for spraying gas onto a moving belt material transported between two nozzle systems. If the belt material is narrower than the discharge zone of the nozzle systems, the gas outlet openings, which are located next to the belt material, are closed by means of a movable closing element to adjust the width of the discharge zone to the width of the belt material.

[0009] Furthermore, US Patent 5,201,132 A discloses a device and a method for cooling, heating, or drying a metal strip transported between two nozzle systems. If the strip's width is narrower than the maximum width of the nozzle system, and thus nozzles positioned next to the strip are directly facing each other, the flow rate of these nozzles can be reduced to minimize the likelihood of generating unwanted vibrations and noise in the strip.

[0010] US Patent 5,182,074 A discloses a device for the continuous cooling of a metal strip running longitudinally between two nozzle systems of a gas cooler. The gas cooling is intended to achieve a uniform temperature distribution across the width of the metal strip after it has been cooled to a predetermined temperature by several cooling rollers. Each nozzle system has nozzle manifolds arranged side-by-side transversely to the direction of travel, extending in the direction of travel. Each nozzle manifold is connected by a branch line to a line containing a blower. Control valves in the branch lines allow the flow rate of the cooling gas to be regulated to uniformly distribute the strip's temperature.

[0011] German Patent Application GB 2 352 731 A describes a device for cooling steel strip on both sides. A plurality of gas jets are directed onto the surface of the steel strip. The jets are arranged in several sections in an arrangement extending transversely to the strip. In at least one section within the arrangement, the jets are directed perpendicular to the central position of the strip. Furthermore, a portion of the jets is directed towards the edge of the strip, with the nozzles angled in opposite directions. This is intended to increase the potential cooling rate without causing torsional vibration about the vertical axis in the center of the strip.

[0012] During heat transfer, the heat transfer coefficient increases depending on the nozzle exit velocity. Rapid cooling of sheet metal, for example with air that has a high heat transfer coefficient, can be achieved by means of an intense impact flow from nozzles directed at the sheet metal surface.

[0013] High nozzle exit velocities are required to achieve high heat transfer coefficients. Tests have shown that the intense flow across the sheet metal leads to vibrations and oscillations. This negatively affects the stability of the sheet or strip's movement in the direction of travel.

[0014] A small distance between the nozzle outlets and the strip surface is desirable to optimally utilize the high gas velocity exiting the nozzles. If the distance between the sheet surfaces and the nozzle outlets is too small, vibrations can cause contact between the nozzles and the strip or sheet surface, significantly reducing the surface quality of the sheet. Therefore, process reliability in the gas heat treatment of thin sheets, especially at high nozzle outlet velocities, requires improvement.

[0015] The object of the invention is therefore to improve a device and a method of the type mentioned at the outset for the heat treatment of flat products, in particular thin sheets of metal, in such a way as to avoid the aforementioned problems, so that optimal stability of the flat product is ensured during passage, especially at high nozzle exit velocities.

[0016] According to the invention, the problem is solved by a device according to claim 1. The preferred embodiments are defined in the dependent device claims.

[0017] In the apparatus according to the invention, each nozzle system has a nozzle box connected to a gas source, wherein several nozzle bars are connected to each nozzle box, extending along its length in the flow direction (D) and spaced apart from one another transversely to the flow direction, wherein the nozzle bars extend from the nozzle box towards the flat product, so that outflow channels are formed between the nozzle bars, wherein the nozzle bars have an equal distance from one another across the width of each nozzle system, wherein each nozzle bar tapers towards the flat product, wherein the passage cross-section for the gas is trapezoidal and the gas can flow out vertically between the nozzle bars after heat exchange with the flat product, wherein each nozzle bar has a trapezoidal cross-section, and wherein each nozzle bar has at least one gas outlet opening.wherein each nozzle system has at least five zones transverse to the direction of flow, wherein each zone has a separate gas supply, wherein a first zone is located between second zones, wherein the gas supply and the at least one gas outlet opening in the first zone are configured for the outlet of the gas with a maximum volume flow rate acting on the center of the flat product, wherein the second zones extend from the longitudinal edges of the flat product towards the first zone, and wherein the gas supplies or the at least one gas outlet opening in the second zones are configured for an adjustable volume flow rate, such that during the heat treatment the volume flow rate of the gas in the second zones can be adjusted in such a way as to avoid or minimize vibrations of the flat product during the heat treatment.wherein during heat treatment the gas volume flow in every second zone is less than the maximum gas volume flow in the first zone, wherein third zones are located next to each second zone, wherein the third zones extend from the longitudinal edges of the flat product alongside the flat product, and wherein the gas inlets or the at least one gas outlet opening in the third zones is / are at least partially closable, wherein the gas inlet in each third zone is completely closable or alternatively the gas outlet openings in the third zones can be completely closable by means of an adjusting device or with the aid of several adjusting devices.

[0018] The center of the flat product is exposed to a maximum gas flow rate in the first zone, thus achieving maximum heat transfer in this zone. In the second zones, the flow rate is reduced compared to the maximum gas flow rate applied to the center of the flat product.

[0019] The application of the inventive method is particularly advantageous in the context of an annealing process for thin sheets, since these, compared to sheets with greater thicknesses, can be excited to vibrations with high amplitudes at lower nozzle exit velocities.

[0020] Experiments with thin sheets of steel have shown that when gas impacts the surface of a sheet at high velocity, it forms vortices as it flows out along the longitudinal edges. This vortex formation, in addition to the excitation caused by the direct impact of the free jets, leads to vibrations and oscillations of the sheet. The invention is based on the finding that these vibrations and oscillations can be avoided when gas flows at high velocities onto the sheet if the gas flow rate in the secondary zones along the longitudinal edges is adjusted to ensure the stability of the strip.

[0021] Tests have shown that belt stability is further improved when gas supply in the third zones is partially or preferably interrupted.

[0022] Preferably, the gas inlets or gas outlet openings in the third zones are controlled or regulated by means of adjusting devices and can be at least partially closed, wherein the adjusting devices can each be actuated by means of a drive, in particular a mechanical, electrical or pneumatic drive.

[0023] The gas supply in the third zones can be completely closed off.

[0024] Alternatively, the gas outlet openings in the third zones can be completely closed using one or more adjusting devices. One or more adjusting devices can be used per zone.

[0025] Preferably, the gas inlets or gas outlet openings in the second zones can be at least partially closed by means of adjusting devices, preferably controlled or regulated, wherein the adjusting devices can each be actuated by means of a drive, in particular a mechanical, electrical or pneumatic drive.

[0026] The gas supply in the second zones can be partially closed with an adjusting device, allowing the gas flow rate to be adjusted or changed. Alternatively, the gas outlet openings in the second zones can be partially closed by means of one or more adjusting devices, allowing the flow rate to be adjusted. The free cross-sectional area of ​​at least one gas outlet opening is also adjustable.

[0027] The adjusting element in the gas supply of the second zone can be designed as a flap or a valve. Alternatively, the adjusting element can be designed such that, when adjusted, the free cross-sectional area of ​​the at least one gas outlet opening in the second zone is reduced. In other words, the free cross-sectional area for the gas is variable. In the third zone, the adjusting element in the gas supply is preferably designed as a shut-off device.

[0028] Preferably, each nozzle bar located in the second zones and / or the third zones has an adjusting device with which all gas outlet openings in a nozzle bar can be at least partially closed in parallel.

[0029] Each nozzle bar tapers towards the flat product. The cross-sectional area for the gas flow is therefore trapezoidal. This design ensures that the gas can flow vertically between the nozzle bars particularly well after heat exchange at the flat product.

[0030] A further development consists in the at least one gas outlet opening being formed at the gas outlet end of a nozzle body that extends towards the flat product. An alternative preferred embodiment is characterized in that each nozzle bar has gas outlet openings of equal size along its length in the direction of flow, which are preferably circular and distributed in at least one row, preferably at equal intervals, along the nozzle bar. The gas exiting from the gas outlet openings is directed perpendicularly towards the flat product.

[0031] According to the invention, each nozzle system or nozzle box is displaceable towards the flat product, preferably steplessly. The nozzle systems are preferably aligned parallel to the flat product.

[0032] According to the invention, the problem is also solved by a method according to claim 8. The preferred embodiments are defined in the dependent method claims.

[0033] The invention includes a method for heat-treating a flat product, in particular a strip-shaped sheet of metal, in a nozzle device comprising a first nozzle system and a second nozzle system, wherein at least one gas jet emerges from at least one gas outlet opening in each nozzle system, wherein the gas jet exiting the gas outlet opening in the first nozzle system is directed towards the front of the flat product and the gas jet exiting the gas outlet opening in the second nozzle system is directed towards the rear of the flat product, and wherein the flat product is conveyed through the nozzle device in a continuous direction by means of conveying means during the heat treatment, wherein each nozzle system comprises a nozzle box connected to a gas source, and wherein several nozzle bars are connected to each nozzle box.which extend along the length in the direction of flow and are spaced apart from each other transversely to the direction of flow, wherein the nozzle bars extend from the nozzle box towards the flat product, so that outflow channels are formed between the nozzle bars, wherein the nozzle bars have an equal distance between each other across the width of each nozzle system, wherein each nozzle bar tapers towards the flat product, wherein the passage cross-section for the gas is trapezoidal and the gas can flow vertically between the nozzle bars after heat exchange with the flat product, wherein each nozzle bar has a trapezoidal cross-section, wherein each nozzle bar has at least one gas outlet opening, wherein each nozzle system has at least five zones transversely to the direction of flow, wherein each zone has a separate gas supply, wherein a first zone is located between second zones.wherein the gas supply and the at least one gas outlet opening in the first zone are configured for the gas to exit with a maximum volume flow rate, wherein in the first zone the gas jet exits from the gas outlet opening with a maximum volume flow rate, wherein the second zones extend from the longitudinal edges of the flat product towards the first zone, wherein the gas supplies or the at least one gas outlet opening in the second zones are configured for an adjustable volume flow rate, such that during the heat treatment the volume flow rate in the second zones can be adjusted in such a way that vibrations of the flat product during the heat treatment are avoided or minimized, wherein during the heat treatment the gas volume flow rate in every second zone is less than the maximum gas volume flow rate acting on the center of the flat product in the first zone.wherein in the second zones the volume flow of the gas jet is adjusted such that vibrations of the flat product are avoided or minimized during heat treatment, wherein third zones are located next to the second zones, wherein the third zones extend from the longitudinal edges of the flat product alongside the flat product, wherein the gas inlets or the at least one gas outlet opening in the third zones is / are at least partially closable, and wherein the volume flow of the gas in the third zones is interrupted during heat treatment.

[0034] The invention offers the advantageous possibility of measuring the width of the flat product and determining the width(s) of the second and / or third zones based on the measurement result. The width of the second zones should be as narrow as possible and selected so that the gas jet(s) act upon the longitudinal edge of the flat product.

[0035] In the invention, the flat product is designed as a strip-shaped sheet of metal, which is heated to annealing temperature before entering the nozzle assembly and cooled in the nozzle assembly, in particular to a predetermined temperature. Consequently, the nozzle assembly is designed as a cooling zone preceded by a heating zone.

[0036] The invention is explained in more detail below with reference to a preferred embodiment. It shows: Fig. 1 schematic representation of a top view of a nozzle system of a device for the heat treatment of a flat product; Fig. 2 a schematic diagram of a device for the heat treatment of a flat product; Fig. 3 a schematic sketch of the cross-section of an embodiment of the device according to the invention, with which the method according to the invention can be carried out.

[0037] In Fig. 1 The diagram schematically shows a top view of a nozzle system 1 of a device for the heat treatment of a flat product. It is a device for cooling thin sheets of steel with a cooling gas, in this case air.

[0038] A sheet 2, which is to be annealed, is heated to a predetermined temperature in an industrial furnace (not shown) and held at that temperature during a holding phase. The sheet 2 then passes vertically through the unit in direction D, guided by conveying means (not shown) designed as two spaced-apart pairs of rollers. During a cooling phase, the sheet 2 is cooled to ambient temperature within the unit. The sheet is guided with its center positioned between nozzle system 1 and a second, identically constructed nozzle system (not shown).

[0039] The cooling gas is applied evenly to both sides of sheet 2, so that the pressure conditions are the same on the front and back of the sheet. Each nozzle system is infinitely adjustable towards sheet 2.

[0040] The nozzle system 1 has a first zone 3, second zones 4a and 4b, and third zones 5a and 5b, perpendicular to the flow direction D. The first zone 3 runs centrally. Two second zones 4a and 4b extend from the longitudinal edges 6a and 6b of the sheet 2 towards the first zone 3. The third zones 5a and 5b are connected to each of the two second zones 4a and 4b. The two third zones 5a and 5b extend from the longitudinal edges 6a and 6b of the sheet 2 alongside the sheet. Each zone contains a multitude of Fig. 1 Gas outlet openings not shown.

[0041] Fig. 2 Figure 1 shows a schematic diagram of a device for the heat treatment of a flat product. A nozzle box 7 is connected to a gas source 8 in the form of a fan. The in Fig. 2 The gas outlet openings in the first zone 3, which are not shown, are connected to the nozzle box 7 by means of a gas supply 9.

[0042] The gas outlet openings in the first zone 3 are designed for the discharge of cooling air at a maximum volume flow rate. In the two second zones 4a and 4b, the gas outlet openings are connected to the nozzle box 7 via the gas inlets 10a and 10b. By means of an adjusting element 12a, 12b in each of the gas inlets 10a and 10b, the volume flow rate of the gas is reduced during the heat treatment in the second zones 4a, 4b such that vibrations of the sheet metal, especially in the direction of the gas outlet openings, are avoided or minimized during the heat treatment.

[0043] During heat treatment, the volume flow of cooling air directly acting on the longitudinal edges 6a, 6b of the sheet metal is therefore lower than the maximum volume flow acting on the center of the sheet metal 2 in the first zone 3. This is in Fig. 2 represented by arrows of varying lengths.

[0044] The width of the second zones 4a, 4b is chosen so that the reduced volume flow of cooling gas exiting from the gas outlet opening 21a, 21b in the second zones 4a, 4b still fully acts on the longitudinal edges of the sheet metal 6a, 6b.

[0045] The two gas inlets 11a, 11b, which lead to the gas outlet openings in the third zones 5a, 5b, are equipped with adjusting devices 13a, 13b in the form of shut-off devices, so that the flow of cooling gas in both third zones 5a and 5b can be interrupted or completely shut off during the cooling period. Tests have shown that this contributes to stabilizing the flow.

[0046] Fig. 3 shows a schematic sketch of the cross-section of an embodiment of the device according to the invention. Fig. 3 The schematic diagram shows that two nozzle bars 14-16 extend across the entire width of the nozzle system, transverse to the flow direction D of the sheet. The first zone 3 is formed by several nozzle bars, of which only one nozzle bar 14 is shown. Gas outlet openings 20 in the nozzle bars 14 in the first zone 3 ( Fig. 1 ) are designed for the outlet of cooling air with a maximum volume flow.

[0047] The distance between the gas outlet openings 20-22 and the flat product 2 is the same. In other words, each gas outlet opening is equidistant from the flat product 2. The gas exits from all gas outlet openings essentially perpendicularly towards the flat product.

[0048] The second zones 4a, 4b are each formed by a nozzle bar 15a, 15b. Depending on the width of the sheet 2, the third zones 5a, 5b can be formed by one or more nozzle bars. Fig. 3 In the third zone 5a, 5b, only one nozzle bar each 16a, 16b is shown. In a plant, sheets of varying widths are typically heat-treated. Fig. 1 A measuring device 19 is shown, with which the width of the sheet metal 2 is measured. Depending on the measurement result, the width of the second and third zones is determined.

[0049] The nozzle bars 14-16 are equidistant from each other across the width of the nozzle system 1. The nozzle bars 14-16 extend from a nozzle box 7 towards the sheet metal 2 and, in the embodiment shown here, have a trapezoidal cross-section. This design ensures that the air heated at the sheet metal surface can flow particularly efficiently perpendicularly away from the sheet metal surface between the nozzle bars.

[0050] Each nozzle bar 14 - 16 has gas outlet openings of equal size along its length in the direction of flow, which are circular and are distributed in a row one behind the other at equal intervals along the nozzle bar.

[0051] The cross-sectional areas of all gas outlet openings 21a, 21b in the nozzle bars 15a, 15b in the second zones can be changed in parallel by means of adjusting devices 17a, 17b in order to reduce the volume flow of the gas during the heat treatment in the second zones 4a, 4b in such a way that vibrations or oscillations of the sheet metal, in particular in the direction of the gas outlet openings during the heat treatment, are avoided or minimized. Fig. 3 It is shown that each nozzle bar 16a, 16b, which is located in the third zones 5a, 5b, has an adjusting element 18a, 18b with which all gas outlet openings 22a, 22b in this nozzle bar can be closed in parallel.

[0052] The inventive method achieves an extremely high heat transfer without any oscillations or vibrations occurring.

[0053] Modifications to the invention are readily possible. The scope is limited by the patent claims.

[0054] The method according to the invention can also be used for heating flat products in a continuous process.

[0055] In the direction of flow, several nozzle bars can be arranged one behind the other. According to the invention, another suitable technical gas can be used instead of air. The adjusting elements can each be actuated by means of a drive, in particular a mechanical, electrical, or pneumatic one. The gas outlet openings can be not only round, but can have any other geometry, for example, square or slotted. Any other shape is also possible.

[0056] As an alternative to round openings in the nozzle bar, at least one gas outlet opening can be formed at the gas outlet end of a nozzle body, with the nozzle body extending towards the flat product. For example, tubular nozzles can be used. Reference symbol list

[0057] 1 Nozzle system 2 Flat product 3 First zone 4a Second zone 4b Second zone 5a Third zone 5b Third zone 6a Longitudinal edges 6b Longitudinal edges 7 Nozzle box 8 Gas source 9 Gas supply to first zone 10a Gas supply to second zone 10b Gas supply to second zone 11a Gas supply to third zone 11b Gas supply to third zone 12a Adjusting device 12b Adjusting device 13a Adjusting device or shut-off device in gas supply to third zone 13b Adjusting device or shut-off device in gas supply to third zone 14 Nozzle bar in first zone 15a Nozzle bar in second zone 15b Nozzle bar in second zone 16a Nozzle bar in third zone 16b Nozzle bar to third zone 17a Adjusting device for Gas outlet openings in second zone 17b Adjusting device for gas outlet openings in second zone 18a Adjusting device or shut-off device for gas outlet openings in third zone 18b Adjusting device orShut-off device for gas outlet openings in third zone 19 Measuring device 20 Gas outlet openings in first zone 21a Gas outlet openings in second zone 21b Gas outlet openings in second zone 22a Gas outlet openings in third zone 22b Gas outlet openings in third zone D Flow direction.

Claims

1. Device for heat treating a flat product (2), in particular strip-shaped sheet metal, with a nozzle device having a first nozzle system (1) and a second nozzle system, wherein each nozzle system has at least one gas outlet opening (20, 21a, 21b, 22a, 22b), wherein the gas outlet opening (21a, 21b, 22a, 22b) in the first nozzle system (1) is directed toward the front side of the flat product (2) and the gas outlet opening in the second nozzle system is directed toward the rear side of the flat product (2), with conveyor means for guiding the flat product during heat treatment through the nozzle device in the direction of flow (D), wherein each nozzle system (1) has a nozzle box (7) connected to a gas source (5), wherein multiple nozzle beams (14, 15a, 15b, 16a, 16b) are connected to each nozzle box (7), which extend over the length in the direction of travel (D) and are arranged at a distance from each other transversely to the direction of travel (D), wherein the nozzle beams (14, 15a, 15b, 16a, 16b) extend from the nozzle box (7) toward the flat product (2) so that outflow channels are formed between the nozzle beams (14, 15a, 15b, 16a, 16b), wherein the nozzle beams (14, 15a, 15b, 16a, 16b) have an equal distance between them across the width of each nozzle system, wherein each nozzle beam (14, 15a, 15b, 16a, 16b) tapers in the direction of the flat product (2), wherein the passage cross-section for the gas is trapezoidal and the gas can flow vertically out between the nozzle beams (14, 15a, 15b, 16a, 16b) after heat exchange with the flat product (2), wherein each nozzle beam (14, 15a, 15b, 16a, 16b) is designed with a trapezoidal cross-section, wherein each nozzle beam (14, 15a, 15b, 16a, 16b) has the at least one gas outlet opening (20, 21a, 21b, 22a, 22b), wherein each nozzle system (1) has at least five zones (3, 4a, 4b, 5a, 5b) transverse to the direction of flow (D), wherein each zone has a separate gas supply (9, 10a, 10b, 11a, 11b), wherein a first zone (3) is located between second zones (4a, 4b), wherein the gas supply (9) and the at least one gas outlet opening (20) in the first zone (3) are arranged for the gas to exit with a maximum volume flow that acts on the center of the flat product (2), wherein the second zones (4a, 4b) extend from the longitudinal edges (6a, 6b) of the flat product (2) in the direction of the first zone (3), and wherein the gas supplies (10a, 10b) or the at least one gas outlet opening (21a, 21b) in the second zones (4a, 4b) are arranged for an adjustable volume flow, so that during the heat treatment the volume flow of the gas in the second zones (4a, 4b) can be adjusted in such a way that vibrations of the flat product during heat treatment are avoided or minimized, wherein during heat treatment the gas volume flow in each second zone (4a, 4b) is lower than the maximum gas volume flow in the first zone (3), wherein third zones (5a, 5b) are located next to the second zones (4a, 4b), wherein the third zones (5a, 5b) extend next to the flat product (2) starting from the longitudinal edges (6a, 6b) of the flat product (2), and wherein the gas supplies (11a, 11b) or the at least one gas outlet opening (22a, 22b) in the third zones (5a, 5b) can be at least partially closed, wherein the gas supply (11a, 11b) in each third zone (5a, 5b) can be completely closed or, alternatively, the gas outlet openings (22a, 22b) in the third zones (5a, 5b) can be completely closed by means of an adjustment element (18a, 18b) or with the aid of multiple adjustment elements.

2. Device according to claim 1, characterized in that the gas supplies (11a, 11b) or the gas outlet openings (22a, 22b) in the third zones (5a, 5b) can be controlled or regulated by means of adjustment elements (18a, 18b) and can be closed at least partially, and in that the adjustment elements (18a, 18b) can each be actuated by means of a drive, in particular a mechanical, electrical, or pneumatic drive.

3. Device according to claim 1 or 2, characterized in that the gas supplies (10a, 10b) or the gas outlet openings (21a, 21b) in the second zones (4a, 4b) can be closed, at least partially, by means of adjustment elements (17a, 17b), preferably controlled or regulated, and in that the adjustment elements (17a, 17b) can each be actuated by means of a drive, in particular a mechanical, electrical, or pneumatic drive.

4. Device according to claim 2 or 3, characterized in that in the second zones (4a, 4b) and / or third zones (5a, 5b), each nozzle beam (15a, 15b, 16a, 16b) has an adjustment element (17a, 17b, 18a, 18b), through which all gas outlet openings (21a, 21b, 22a, 22b) in a nozzle beam (15a, 15b, 16a, 16b) can be at least partially closed in parallel.

5. Device according to any one of claims 1 to 4, characterized in that the at least one gas outlet opening (21a, 21b, 22a, 22b) is formed at the gas outlet end of a nozzle body which extends toward the flat product (2).

6. Device according to any one of claims 1 to 4, characterized in that each nozzle beam (14, 15a, 15b, 16a, 16b) has gas outlet openings (20, 21a, 21b, 22a, 22b) of equal size over its lenght in the direction of flow (D), which are preferably circular and are distributed in at least one row one behind the other, preferably at equal distances from each other, over the nozzle beam (14, 15a, 15b, 16a, 16b).

7. Device according to any one of the preceding claims, characterized in that each nozzle system (1) or each nozzle box (7) can be moved in the direction of the flat product (2), preferably continuously.

8. Method for heat treating a flat product, in particular a strip-shaped metal sheet, in a nozzle device having a first nozzle system and a second nozzle system, wherein at least one gas jet emerges from each nozzle system (1) from at least one gas outlet opening (21a, 21b, 22a, 22b), wherein the gas jet emerging from the gas outlet opening in the first nozzle system is directed at the front side of the flat product and the gas jet emerging from the gas outlet opening in the second nozzle system is directed at the rear side of the flat product, and wherein the flat product (2) is guided by means of conveyor means through the nozzle device in the direction of flow (D) during the heat treatment, wherein each nozzle system (1) has a nozzle box (7) connected to a gas source (5), wherein multiple nozzle beams (14, 15a, 15b, 16a, 16b) are connected to each nozzle box (7), which extend over the length in the direction of flow (D) and are arranged at a distance from each other transversely to the direction of flow (D), wherein the nozzle beams (14, 15a, 15b, 16a, 16b) extend from the nozzle box (7) toward the flat product (2) so that outflow channels are formed between the nozzle beams (14, 15a, 15b, 16a, 16b), wherein the nozzle beams (14, 15a, 15b, 16a, 16b) have an equal distance between them across the width of each nozzle system, wherein each nozzle beam (14, 15a, 15b, 16a, 16b) tapers toward the flat product (2), wherein the passage cross-section for the gas is trapezoidal and the gas can flow out perpendicularly between the nozzle beams (14, 15a, 15b, 16a, 16b), wherein each nozzle beam (14, 15a, 15b, 16a, 16b) is designed with a trapezoidal cross-section, wherein each nozzle beam (14, 15a, 15b, 16a, 16b) has the at least one gas outlet opening (20, 21a, 21b, 22a, 22b), wherein each nozzle system (1) has at least five zones (3, 4a, 4b, 5a, 5b) transverse to the direction of flow (D), where each zone (3, 4a, 4b, 5a, 5b) has a separate gas supply (9, 10a, 10b, 11a, 11b), wherein a first zone (3) is located between second zones (4a, 4b), wherein the gas supply (9) and the at least one gas outlet opening (20) in the first zone are arranged for the gas to exit at a maximum volume flow, wherein in the first zone (3) the gas jet exits from the gas outlet opening (20) at a maximum volume flow, wherein the second zones (4a, 4b) extend from the longitudinal edges (6a, 6b) of the flat product (2) in the direction of the first zone (3), wherein the gas supplies (10a, 10b) or the at least one gas outlet opening (21a, 21b) in the second zones (4a, 4b) are designed for an adjustable volume flow, so that during heat treatment the volume flow in the second zones can be adjusted in such a way that vibrations of the flat product during heat treatment are avoided or minimized, wherein during heat treatment the gas volume flow in each second zone (4a, 4b) is lower than the maximum gas volume flow that acts on the center of the flat product (2) in the first zone (3), wherein in the second zones (4a, 4b) the volume flow of the gas jet is adjusted in such a way that vibrations of the flat product (2) during heat treatment are avoided or minimized, wherein third zones (5a, 5b) are located next to the second zones (4a, 4b), wherein the third zones (5a, 5b) extend from the longitudinal edges (6a, 6b) of the flat product (2) alongside the flat product (2), wherein the gas supplies (11a, 11b) or the at least one gas outlet opening (22a, 22b) in the third zones (5a, 5b) can be at least partially closed, and wherein the volume flow of the gas in the third zones (5a, 5b) is interrupted during the heat treatment.

9. Method according to claim 8, characterized in that the width of the flat product (2) is measured and, depending on the measurement result, the width of the second zones (4a, 4b) and / or the third zones (5a, 5b) is or are determined.

10. Method according to claim 8 or 9, characterized in that the flat product (2) is designed as a strip-shaped sheet of metal and is heated to annealing temperature before entering the nozzle device and cooled in the nozzle device, in particular to a predetermined temperature.