Device for temperating articles

Abstract

The invention relates to a device (1) for controlling the temperature of an article (2), comprising: a chamber (5) for accommodating the article (2), which chamber (5) is surrounded by a chamber circumference (7), a bottom element (4) and a cover element (8); a heating element; a running wheel (9) for circulating a first gas, said running wheel (9) being arranged in the chamber (5); and a running wheel drive (12), by means of which the running wheel (9) is rotated. The heating element is formed by the rotor (9) having the rotor drive (12).

Description

Technical Field

[0001] The present invention relates to a device for adjusting the temperature of an object, in particular a metal object, the device comprising: a chamber for accommodating the object, the chamber being surrounded by a chamber periphery, a bottom element and a top cover element; a heating element; a working wheel for circulating a first gas, the working wheel being arranged in the chamber; and a working wheel driving device, by which the working wheel is caused to rotate.

[0002] The present invention also relates to a method for controlling the temperature of an object, in particular a metal object, wherein the object is introduced into a device comprising a chamber for accommodating the object, the chamber being surrounded by a chamber periphery, a bottom element and a cover element, the temperature in the chamber being changed by a heating element, and a first gas being circulated in the chamber by a working wheel arranged in the chamber, and the working wheel being rotated by a working wheel drive device. Background Art

[0003] Many industrial furnaces are used for heat treatment of various materials such as aluminum, steel, non-ferrous metals, etc., in which heat transfer is achieved by convection. Here, the annealing workpiece to be heated or cooled is flowed through or around with air or other various protective gases. This allows uniform and rapid heat treatment of the annealing workpiece.

[0004] In particular, the steel industry is keen to use hydrogen as a protective gas, because the heat transfer is better than with air due to the good thermal conductivity of hydrogen. In addition, hydrogen also has reducing properties on the annealed workpiece surface. Due to the low density of hydrogen, the fan motor responsible for convection requires less energy.

[0005] Traditionally, in such facilities, the energy input is achieved via individual calandria heaters, wherein the heating conductor material needs to be subjected to a certain excess temperature in order to achieve heat transfer, that is, the heating conductor material always needs to be hotter than the furnace temperature.

[0006] It is known from the prior art to control the fan motor in the furnace chamber by means of the gas density. Thus, for example, DE 35 19 994 C1 describes a method for accelerating the cooling of annealing workpieces in an annealing furnace after the annealing process, wherein the cooling gas is guided through the furnace chamber in a circuit and outside the furnace chamber through a cooler and a circulating fan, the cooling gas first circulates at a substantially constant circulation speed, and after reaching a predetermined mass density of the cooling gas to be accelerated by the circulating fan, which is substantially determined by the temperature, the circulation speed of the cooling air is reduced according to the temperature-related increase in the mass density. The cooling time should therefore be reduced.

[0007] US4543891A describes an annealing device, which includes: a fan for circulating hot gases within a furnace; and a motor, a load being applied to the motor by the fan; and a load converter for detecting the electrical load on the motor, and the load converter is capable of generating a load signal; a load change detector, which responds to the load signal and is capable of generating a load change signal; a frequency reference integrator, which responds to the load change signal and is capable of generating, storing and changing a reference signal in a manner responsive to the load change signal; and a drive device having an adjustable frequency, which responds to the reference signal and is capable of supplying AC power having a variable frequency to the motor. Summary of the invention

[0008] The object of the present invention is to specify a possibility for controlling the temperature of objects.

[0009] The object of the invention is achieved in the case of the device mentioned in the introduction in that the heating element is formed by the impeller with the impeller drive.

[0010] Furthermore, the object is achieved by the method mentioned at the outset, according to which it is provided that the impeller with the impeller drive is used as the heating element.

[0011] Advantageously, by using the impeller with the impeller drive as a heating element, thermal energy can be introduced directly into the circulating gas. In addition, a simple possibility of influencing the temperature of the article can be provided.

[0012] According to one embodiment of the present invention, it can be provided that one of the impellers with the impeller drive is a single heating element; or a plurality of impellers with each impeller drive are provided, and these impellers are a plurality of single heating elements. By abandoning the additional heating element, the device can be constructed more simply. In addition, the effects mentioned above can be further improved.

[0013] According to a further embodiment of the invention, it can be provided that the chamber periphery is surrounded by a supporting periphery and preferably the cover element is surrounded by a supporting cover element. It is thus possible to reduce the resistance of the thermally loaded chamber housing to pressure loads, so that a larger construction free space can be achieved for the housing, in particular with regard to: achieving a more uniform temperature distribution in the chamber by heat conduction for heating or for temperature maintenance and / or achieving a faster heat dissipation by heat conduction for cooling the items.

[0014] According to a further embodiment of the invention, it can be provided that a thermal insulation is provided between the chamber periphery and the support periphery and preferably between the cover element and the support cover element in order to reduce the transfer of thermal energy to the support periphery or the support cover element, so that the wall thickness can be reduced in this case. In addition, it can be achieved that the thermal energy that needs to be introduced into the chamber by at least one impeller with at least one impeller drive in order to achieve a certain predefinable temperature can be reduced, because the thermal efficiency of the device can be improved by the thermal insulation.

[0015] In order to further improve this effect, according to one embodiment of the invention, provision can be made for the thermal insulation element to have a plurality of layers, so that a plurality of boundary surfaces or transition surfaces can be realized within the thermal insulation element.

[0016] A further improvement of these effects can be achieved by a further embodiment of the invention according to which the plurality of layers are made of different materials. This can also reduce costs by providing more expensive insulation material only in areas with a higher temperature load, whereas less expensive insulation material can be used in areas with a reduced thermal load. This can also achieve a better adaptation of the thermal properties of the device facing inwards or outwards.

[0017] According to a further embodiment of the invention, it can be provided that the fan wheel has a first diameter, and furthermore the chamber has a second diameter, and the first diameter is between 20% and 80% of the second diameter. By enlarging the fan wheel, the power requirement of the electric motor having the fan wheel can be increased, and thus the input of heat energy into the circulating gas can also be increased. For example, a 10% increase in diameter increases the power requirement by a factor of 1.6. Within the framework of the evaluation of the invention, it was determined that a fan wheel diameter within the mentioned range is advantageous.

[0018] In order to increase the power consumption of the fan wheel with the impeller drive, it can also be provided according to another embodiment of the invention that the device has at least one mixing element for mixing at least one second gas into the first gas. By mixing in the second gas, the density of the circulating gas can be influenced. For example, doubling the density of the circulating gas also doubles the power requirement of the impeller drive.

[0019] In order to further reduce the pressure load on the chamber periphery and the chamber top cover, that is, in order to further reduce the pressure load on the inner shell of the chamber, according to another embodiment of the present invention, it can be provided that at least one pressure measuring element is provided so that the pressure acting from the chamber on the chamber periphery and the top cover element differs from the pressure existing between the chamber periphery and the supporting periphery and between the top cover element and the supporting top cover element by a maximum of 10%. Therefore, the pressure in the chamber can be measured by the pressure measuring element, and the pressure acting from the outside on the chamber periphery and the chamber top cover can be adapted accordingly.

[0020] According to one embodiment of the method, in order to change the temperature in the chamber, it can be provided that this is carried out by changing the power consumption of the impeller with the impeller drive.

[0021] To this end, according to further embodiments of the method, it can be provided that, as already explained, a second gas different from the first gas is mixed into the first gas and the power consumption is changed by changing the mixing ratio of the two gases, and / or to change the power consumption of the impeller with the impeller drive, the pressure in the chamber is changed, and / or to change the power consumption of the impeller with the impeller drive, the rotational speed of the impeller drive is changed and optionally the rotational speed of the impeller. For example, by doubling the rotational speed of the fan wheel, the power requirement of the impeller drive can be increased by a factor of four.

[0022] In order to change the density of the circulating gas, according to one embodiment of the method, a gas having a molecular weight at least 50% greater than that of the first gas is preferably used as the second gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] For a better understanding of the invention, the invention is explained in more detail with the aid of the following drawings.

[0024] The simplified diagram is as follows: Figure 1 Displays equipment used to adjust the temperature of items. DETAILED DESCRIPTION

[0025] First of all, it should be pointed out that in the various embodiments described, the same components are provided with the same reference numerals or the same component names, and the disclosure contained in the entire description can be applied to the same components with the same reference numerals or the same component names in a meaningful manner. The orientation descriptions selected in the description, such as top, bottom, side, etc., also refer to the directly described and described drawings, and these orientation descriptions can be applied to the new orientation in a meaningful manner when the orientation changes.

[0026] exist Figure 1 A device 1 for tempering an object 2 is described in detail.

[0027] The device 1 is described as a so-called bell furnace, which comprises a furnace bell 3 and a bottom element 4. However, the described geometry of the bell furnace should not be understood restrictively. In addition, the device 1 can also look different overall than in Figure 1 As described in, as long as the device is suitable for temperature control of object 2.

[0028] The term “temperature control” within the meaning of the present invention includes the maintenance of temperature, the cooling of the object 2 and in particular the heating of the object 2 .

[0029] The object 2 can be a product, in particular a metal product, such as a sheet or slab, etc., or a raw material, such as a metal, etc. The processes in the device 1 can be, for example: melting of the object; or certain reactions in or on or with the object 2, such as phase changes; hardening of the metal object 2; temperature control of the object; etc. This enumeration is merely exemplary and should not be understood as limiting. In general, the device 1 can be used in a thermal treatment facility in order to treat the object 2 thermally, i.e. at elevated temperatures, in batches or continuously.

[0030] Merely by way of example, it should also be noted that the device 1 can be used for objects 2 made of aluminum or aluminum alloys or, in general, of non-ferrous metals (for example light metals, non-ferrous metals) or of steel.

[0031] Furthermore, it is possible for only a single object 2 or a plurality of objects 2 to be subjected to a heat treatment simultaneously in the device.

[0032] When the device 1 or its components are described in more detail below, this does not mean that the device 1 cannot have other components or other components, which are known from the prior art in such a device 1. For example, the device 1 can also have various measuring probes, closed-loop control and / or open-loop control devices, etc.

[0033] The device 1 has a chamber 5 for receiving the objects 2 for processing in the device 1 or during processing in the device. Figure 1 It can be seen that a plurality of objects 2, optionally different objects, can also be subjected to a heat treatment simultaneously in the device 1. Optionally, each object 2 can be held on a holding device 6, which can be arranged in the chamber 5.

[0034] The chamber 5 is surrounded by a bottom element 4, a chamber periphery 7 and a cover element 8. The chamber periphery 7 can be arranged to stand on the bottom element 4. In addition, the cover element 8 can be formed in one piece with the chamber periphery 7, as is known from bell-type furnaces. However, the bottom element 4 can also be formed in one piece with the chamber periphery 7 and optionally with the cover element 8. Here, a closable opening can be formed optionally in the chamber periphery 7 and / or in the cover element 8 as an entrance to the chamber 5. The chamber periphery 7 can define the volume of the chamber 5 with the cover element 8 and the bottom element 4.

[0035] In addition, the device 1 has a running wheel 9 (also referred to as a blower wheel). The running wheel 9 is arranged in the chamber 5, in particular below at least one object 2. The running wheel 9 can be arranged above the bottom element 4 or at least partially in a corresponding recess within the bottom element 4. Preferably, the running wheel 9 is arranged between the object 2 and the bottom element 4.

[0036] The working wheel 9 is used to circulate the first gas within the chamber 5 during the heat treatment of the object 2, as in Figure 1 In this case, the circulation can be carried out, for example, in such a way that the first gas is guided beside at least one object 2 and flows again in the center in the direction of the impeller 9, as in Figure 1 For the first gas to flow back in the center, a central flow channel 11 can be provided in the chamber 5. This flow channel can be provided or formed, for example, in the holding device 6 for at least one object.

[0037] As the first gas, hydrogen (H2) can be used, for example. However, depending on the heat treatment to be performed on the object, the first gas can also be another gas, for example nitrogen (N2) and / or a carbon-donating gas such as carbon dioxide (CO2), in order to thus perform nitriding, carburizing or carbonitriding. These gases are to be understood only as examples, and preferably, for the reasons explained above, hydrogen is used as the first gas if no other reactions with the object 2 should occur during the heat treatment.

[0038] The first gas can be fed into the chamber 5 via a supply line not described further, optionally after one or more purification steps of the chamber atmosphere, for example by evacuating the chamber 5 one or more times and flushing it with a gas, in particular with the first gas.

[0039] The impeller 9 is operatively connected to the impeller drive 12, for example, via a shaft 13, so that the impeller can be placed in a rotational motion by the impeller drive 12. The impeller drive 12 is in particular an electric motor, but can also be formed by other suitable drive devices. Similarly, the impeller 9 can also have other operative connections with the impeller drive 12, for example, via a gear or multiple gears or via a chain drive mechanism, etc.

[0040] The impeller drive 12 and / or the shaft 13 or the mentioned working connection can be arranged, for example, at least partially in a recess in the bottom element 4, as is the case in Figure 1 The impeller drive 12 can also be arranged below the bottom element 4.

[0041] The invention provides the possibility that the device 1 has more than one impeller 9 and more than one impeller drive 12, for example two or three impeller drives, etc. Preferably, each impeller 9 is operatively connected to each impeller drive 12, for example, via each shaft 13. A plurality of impellers 9 can be arranged side by side in the region of the bottom element 4. However, some or all of these impellers can also be arranged in the region of the chamber circumference 7 or the cover element 8, so that different flow conditions can be formed in the chamber 5. The impeller drives 12 corresponding to the impellers 9 can be arranged in the device 1 accordingly.

[0042] The device 1 also has at least one heating element. The heating element is formed by at least one impeller 9 having an impeller drive 12. In a preferred embodiment of the device 1, it is provided that an impeller 9 having an impeller drive 12 is a single heating element, or a plurality of impellers 9 each having an impeller drive 12 are arranged in the device 1, and these impellers are a plurality of single heating elements. Unlike in this type of device 1 according to the prior art, energy input is not achieved through a separate calandria radiator or a separate heating element. In the case of energy input through a separate calandria radiator or a separate heating element, the heating conductor material needs to be subjected to a certain excess temperature in order to achieve heat transfer. That is, the heating conductor material needs to be always hotter than the temperature in the chamber 5. The present invention circumvents this defect in that at least one impeller 9 having an impeller drive 12 is directly used as an energy source (heating source).

[0043] Although preferably no further heating elements are provided in the device 1 for heating the circulating gas in the chamber 5, in a non-preferred embodiment, further heating elements, for example resistance heating elements or radiation heating elements, other than the impeller 9 with the impeller drive 12 can be provided, by means of which the energy input into the circulating gas can be supported if necessary. The at least one additional heating element can be provided in the chamber 5, for example, on the chamber circumference 7 or on the cover element 8.

[0044] The device 1 can be used to implement a method for temperature control of objects 2, in particular metal objects 2, according to which the objects 2 are introduced into the device 1 and the temperature in the chamber is changed by at least one impeller 9 with an impeller drive 12. In this case, energy is directly introduced into the circulating gas in the chamber 5 by the impeller 9 with the impeller drive 12.

[0045] In order to change the temperature in the chamber 5, it can be provided that this is changed by changing the power consumption of at least one impeller 9 with at least one impeller drive 12. By increasing the power requirement of at least one impeller 9 with at least one impeller drive 12, the temperature of the circulating gas in the chamber 5 can be increased. Conversely, by reducing this power requirement, the temperature of the circulating gas in the chamber 5 can be reduced. Since the circulating gas in the chamber is in direct contact with the at least one object, a change in the temperature of the object can also be achieved by changing the temperature of the circulating gas.

[0046] To change the power consumption, for example, the density of the circulating gas in the chamber 5 can be changed. As explained above, doubling the density of the circulating gas in the chamber 5 doubles the power requirement of the at least one impeller 9 having the at least one impeller drive 12.

[0047] According to one embodiment, the density can be achieved, for example, by mixing at least one second gas into the first gas. The second gas is different from the first gas. In particular, the second gas has a molecular weight that is at least 50% higher than the first gas.

[0048] As the second gas, nitrogen or argon can be used, for example (as long as the first gas is not already nitrogen or argon). Other suitable gases can also be used. In this case, the temperature change can be set by the mixing ratio of the two gases or the individual gases, because by increasing the density, that is, by increasing the volume fraction of the heavy second gas in the chamber 5, the power requirement of the at least one fan wheel 9 with the at least one fan drive 12 increases. Conversely, by reducing the volume fraction of the heavy second gas in the chamber 5, the power requirement of the at least one fan wheel 9 with the at least one fan drive 12 can be reduced.

[0049] The specific mixing ratio of the gases in the individual method steps depends on the object 2 to be processed and the type of thermal treatment of the object. The mixing ratio can be determined by a person skilled in the art by a small amount of experimentation without inventive effort, so that a description of the specific mixing ratio is superfluous.

[0050] According to one embodiment, in order to set the desired mixing ratio of the gases for the circulating gas, the device 1 can have at least one mixing element for mixing at least one second gas into the first gas. The mixing element can be, for example, a mixing valve which can be controlled in a closed loop and / or in an open loop.

[0051] However, it is also possible to provide a plurality of separate gas lines for different gases entering the chamber 5. In this case, the mixing ratio can be closed-loop controlled and / or open-loop controlled, for example, by setting and / or measuring the volume flow of the individual gases.

[0052] In addition or as an alternative to this, the density change can also be achieved by increasing the pressure or reducing the pressure in the chamber 5. The pressure increase can be achieved by feeding more first gas and / or at least one second gas into the chamber. Thus, by increasing the pressure in the chamber 5, the power consumption of at least one blower wheel 9 with at least one blower drive 12 can be increased. Conversely, by reducing the pressure in the chamber 5, the power consumption of at least one blower wheel 9 with at least one blower drive 12 can be reduced.

[0053] It should also be noted with regard to this embodiment that the person skilled in the art can determine the advantageous pressure increase for the respective application by a small number of experiments without inventive effort, so that the specification of a specific pressure is superfluous. It should be noted merely as an example that the pressure can be between 30 mbar and 80 mbar.

[0054] To increase the pressure in the chamber 5, it is advantageous if, according to one embodiment of the device 1, the chamber periphery 7 is surrounded by a supporting periphery 14 and preferably the cover element 8 is surrounded by a supporting cover element 15. The supporting periphery 14 can optionally also be supported on the bottom element 4.

[0055] The support cover element 15 can be formed in one piece with the support periphery 14. However, the bottom element 4 can also be formed in one piece with the support periphery 14 and optionally with the support cover element 15. In this case, a closable opening can optionally be provided in the support periphery 14 and / or in the support cover element 15 as an access to the chamber 5.

[0056] This double-shell construction of the "housing" of the chamber 5 has the following advantages: Thus, the chamber periphery 7 and the cover element 8, which are subjected to thermal loads, can be protected from pressure loads. For this purpose, a first pressure can be applied to the chamber periphery 7 and the cover element 8 on the inside (on the chamber side), and a second pressure can be applied to the chamber periphery 7 and the cover element 8 on the outside (on the support housing side).

[0057] According to a further embodiment of the device 1, it can be provided that at least one pressure measuring element is arranged in the device and / or on the device. Figure 1 Not described in the specification), so that the pressure acting from the chamber 5 on the chamber periphery 7 and the top cover element 8 differs from the pressure between the chamber periphery 7 and the supporting periphery 14 and between the top cover element 8 and the supporting top cover element 15 by a maximum of 10%, in particular a maximum of 5%, preferably a maximum of 2.5%. By means of at least one pressure measuring element, for example, the pressure difference (the difference between two pressures) can be determined and, depending on the result, the pressure externally between the chamber periphery 7 and the supporting periphery 14 and between the top cover element 8 and the supporting top cover element 15 can be either reduced or increased. For this purpose, at least one Figure 1 Fluid lines not shown in the figure can be introduced into the intermediate space between the chamber periphery 7 and the support periphery 14 and between the cover element 8 and the support cover element 15, and at least one fluid line can be led out of the intermediate space.

[0058] To provide pressure between the chamber periphery 7 and the support periphery 14 and between the cover element 8 and the support cover element 15, nitrogen or argon or a gas mixture consisting of or including nitrogen or argon can be used, for example.

[0059] It can also be provided that the circulating gas is introduced from the chamber 5 into the intermediate space between the chamber periphery 7 and the supporting periphery 14 and between the cover element 8 and the supporting cover element 15 in order to achieve pressure compensation. However, this embodiment is not a preferred embodiment, because in the preferred embodiment the supporting periphery 14 and the supporting cover element 15 are not subjected to the same thermal load as the chamber periphery 7 and the cover element 8.

[0060] The pressure exerted externally and internally on the chamber periphery 7 and the cover element 8 is preferably of equal magnitude.

[0061] By such a configuration of the device, it is also possible to reduce the wall thickness of the chamber periphery 7 and optionally the cover element 8. For example, the chamber periphery 7 and optionally the cover element 8 may have a wall thickness of between 3 mm and 15 mm.

[0062] The supporting periphery 14 and optionally the supporting cover element 15 may have a wall thickness of between 5 mm and 30 mm.

[0063] It goes without saying that other measuring sensors that are used to measure pressure can also be adopted. In addition, a plurality of measuring sensors can also be provided accordingly to measure each of the pressures.

[0064] The data from the pressure measuring sensor can be processed by a data processing device for closed-loop control and / or open-loop control of at least one of the pressures.

[0065] Another alternative or additional possibility of changing the power consumption of at least one impeller 9 with at least one impeller drive 12 is to change the rotation speed of the impeller drive 12 and optionally the rotation speed of the impeller 9. The change in rotation speed acts as a change of the square of the power consumption and thus influences the generation of thermal energy and the feeding of thermal energy to the circulating gas in the chamber 5. For example, doubling the rotation speed of the impeller drive 12 and optionally the impeller 9 can increase the power demand by a factor of four. Thus, the actual value of the temperature in the chamber and the deviation of the actual value from the rated value can be determined by a closed-loop control and / or open-loop control device. Depending on the deviation, the rotation speed can then be increased or reduced by a closed-loop control and / or open-loop control device or in another suitable manner, so that more or less thermal energy is provided for changing the temperature of the circulating gas.

[0066] According to a further embodiment of the device 1, in addition to or as an alternative to at least one of the possibilities mentioned, the power consumption of at least one impeller 9 with at least one impeller drive 12 can be varied by changing the diameter 16 (maximum outer diameter) of the fan wheel 9. Such a change is naturally preferably already taken into account when designing the device 1 and the objects 2 to be processed, because such a change can only be implemented with great effort during the ongoing operation of the device. That is, the diameter 16 of the fan wheel 9 is determined in advance according to the different conditions of the expected demand for thermal energy for processing the objects 2, and the fan wheel 9 with the corresponding diameter 16 is installed in the device 1. In this regard, according to an embodiment of the device 1, it has proven to be advantageous if the diameter of the fan wheel 9 is between 20% and 80%, in particular between 40% and 70%, of the second diameter 17 of the chamber 5 (maximum inner diameter of the chamber 5, viewed in the same direction as the diameter 16 of the fan wheel 9).

[0067] A change in the diameter 16 of the fan wheel results in a change in the power requirement of the fifth power. For example, a 10% increase in the diameter results in a 1.6-fold increase in the power requirement.

[0068] If Figure 1It can be seen that in the double-shell embodiment of the device 1, it can be provided that a thermal insulation 18 is arranged between the chamber periphery 7 and the supporting periphery 14 and preferably between the cover element 8 and the supporting cover element 15. Preferably, the thermal insulation 18 extends over the entire volume of the intermediate space.

[0069] The thermal insulation 18 can also be loaded with the pressure mentioned above if necessary, which can be applied as required between the chamber periphery 7 and the supporting periphery 14 and preferably between the cover element 8 and the supporting cover element 15. For example, the thermal insulation 18 can also be loaded with nitrogen or argon under pressure.

[0070] The heat insulation element 18 includes or consists of a heat insulation material, such as ceramic fiber material, mineral wool, graphite, and the like.

[0071] According to other embodiments of the device 1, the thermal insulation element 18 can be multi-layered, for example comprising a first thermal insulation layer 19 and a second thermal insulation layer 20 lying on the first thermal insulation layer, in particular directly lying on the first thermal insulation layer. The thermal insulation element 18 can also have more than two thermal insulation layers.

[0072] According to a further embodiment, it can be provided that the plurality of heat-insulating layers 19, 20 are made of or have different materials from one another. The heat-insulating properties can thus be changed accordingly. For example, the heat-insulating layer 19 near the chamber periphery 7 and the cover element 8 can be made of a material that has better heat-insulating properties than the material of the heat-insulating layer 20. The heat-insulating effect can thus be designed to decrease from the inside to the outside within the heat-insulating element 18.

[0073] If the device 1 is also intended to be used for cooling objects 2, it can be provided that the device is flow-connected to an external cooler (heat exchanger) in order to thereby reduce the cooling time. For this purpose, the circulating gas can be guided in a circuit from the chamber 5 via the cooler through corresponding fluid lines.

[0074] The device 1 has the advantage that no burner with flame is required for the thermal treatment of the objects 2 .

[0075] The exemplary embodiments show or explain possible embodiments; a combination of individual embodiments with one another is also possible.

[0076] Finally, for the sake of clarity, it is pointed out that, in order to better understand the structure of the device 1 , this device is not necessarily drawn to scale.

[0077] Reference numerals list 1 device 2 Items 3 hoods 4 Bottom element 5 Chambers 6. Holding device 7 Chamber periphery 8 Top cover element 9 working wheels 10 Flow Arrows 11 Flow channels 12 working wheel drive 13 Axis 14 Support periphery 15 Supporting top cover element 16 Diameter 17 Diameter 18 Insulation 19 Insulation layer 20 Insulation Layer

Claims

1. A device (1) for adjusting the temperature of an object (2), in particular a metal object (2), comprising: - a chamber (5) for receiving an object (2), the chamber (5) being surrounded by a chamber perimeter (7), a bottom element (4) and a cover element (8); - Heating elements; - an impeller (9) for circulating the first gas, the impeller (9) being arranged in the chamber (5); - and a running wheel drive device (12), by means of which the running wheel (9) is caused to rotate; It is characterized in that the heating element is formed by the impeller (9) having the impeller drive (12).

2. The device (1) according to claim 1, characterized in that One of the impellers (9) having the impeller drive device (12) is a single heating element; or a plurality of impellers (9) each having a impeller drive device (12) are provided, and the plurality of impellers are a plurality of single heating elements.

3. The device (1) according to claim 1 or 2, characterized in that The chamber periphery (7) is surrounded by a supporting periphery (14), and preferably the cover element (8) is surrounded by a supporting cover element (15).

4. The device (1) according to claim 3, characterized in that A thermal insulation (18) is arranged between the chamber periphery (7) and the supporting periphery (14), and preferably between the cover element (8) and the supporting cover element (15).

5. The device (1) according to claim 4, characterized in that The thermal insulation element (18) has a plurality of layers.

6. The device (1) according to claim 5, characterized in that The plurality of layers are made of materials different from each other.

7. The device (1) according to any one of claims 1 to 6, characterized in that The blower wheel (9) has a first diameter (16), and the chamber (5) has a second diameter (17), and the first diameter (16) is between 20% and 80% of the second diameter (17).

8. The device (1) according to any one of claims 1 to 7, characterized in that The device has at least one mixing element for mixing at least one second gas into the first gas.

9. The device (1) according to any one of claims 3 to 8, characterized in that At least one pressure measuring element is arranged so that the pressure acting from the chamber (5) on the chamber periphery (7) and the cover element (8) differs from the pressure existing between the chamber periphery (7) and the supporting periphery (14) and between the cover element (8) and the supporting cover element (15) by a maximum of 10%.

10. A method for controlling the temperature of an object (2), in particular a metal object (2), wherein the object is introduced into a device (1), the device (1) comprising a chamber (5) for accommodating the object (2), the chamber being surrounded by a chamber periphery (7), a bottom element (4) and a cover element (8), the temperature in the chamber (5) being changed by a heating element, and a first gas being circulated in the chamber (5) by a running wheel (9) arranged in the chamber (5), and the running wheel (9) being caused to rotate by a running wheel drive device (12), characterized in that: The impeller (9) having the impeller drive (12) is used as a heating element.

11. The method according to claim 10, characterized in that By varying the power consumption of the impeller (9) with the impeller drive (12), the temperature in the chamber is varied.

12. The method according to claim 11, characterized in that A second gas different from the first gas is mixed into the first gas, and power consumption is changed by changing the mixing ratio of the two gases.

13. The method according to claim 12, characterized in that As the second gas, a gas having a molecular weight at least 50% greater than that of the first gas is used.

14. The method according to any one of claims 11 to 13, characterized in that In order to vary the power consumption of the impeller (9) with the impeller drive (12), the pressure in the chamber (5) is varied.

15. The method according to any one of claims 11 to 14, characterized in that In order to change the power consumption of the impeller (9) having the impeller drive (12), the rotational speed of the impeller drive (12) and optionally the rotational speed of the impeller (9) are changed.

Images