Device for Induction Heating of at Least One Workpiece and Method for Induction Heating of at Least One Workpiece

Abstract

The invention relates to a device for inductively heating at least one workpiece, in particular a substantially strip-shaped workpiece, including at least one furnace housing; at least one inductor arrangement arranged within the furnace housing, the inductor arrangement being arranged at least partially in an inductor region of the furnace housing; at least one heating region for receiving process gas. The heating region being arranged within the furnace housing; and separating material for separating, in particular for thermally separating, the inductor region and the heating region. Furthermore, the invention relates to a method for inductively heating at least one workpiece.

Claims

1-16. (canceled)

17. A device for inductively heating at least one workpiece, in particular a substantially strip-shaped workpiece, comprising at least one furnace housing; at least one inductor arrangement arranged within the furnace housing, the inductor arrangement being arranged at least partially in an inductor region of the furnace housing; at least one heating region for receiving process gas, the heating region being arranged within the furnace housing; and separating material for separating, in particular for thermally separating, the inductor region and the heating region; wherein the separating material is designed in such a way that there is a fluidic connection between the inductor region and the heating region, wherein the separating material is designed as an at least partially permeable material for the fluidic connection between the inductor region and the heating region and the permeable material is designed gas-permeable.

18. The device according to claim 17, wherein the separating material has at least one through-opening for the fluidic connection between the inductor region and the heating region.

19. The device according to claim 17, wherein the separating material comprises a fabric, in particular a fabric made of high-temperature fibers.

20. The device according to claim 17, wherein the inductor region has at least one inlet for feeding in housing gas; and a control means regulates the feed of housing gas into the inductor region in such a way that there is a pressure gradient from the housing gas arranged in the inductor region in the direction of process gas arranged in the heating region.

21. The device according to claim 20, wherein the inductor region has at least one outlet.

22. The device according to claim 20, wherein the device further comprises at least one measuring means for measuring a pressure within the inductor region and/or within the heating region and/or the differential pressure between the inductor region and the heating region.

23. The device according to claim 20, wherein the device further comprises at least one further measuring means for measuring a pressure within the inductor region and/or the ambient air and/or the differential pressure between the inductor region and the ambient air.

24. The device according to claim 20, wherein the device further comprises at least one flow measuring means for measuring a flow rate of the housing gas fed in, and/or the device further comprises at least one dew point measuring means for measuring the dew point of the gas mixture arranged in the inductor region and/or the dew point of the gas mixture arranged in the process region.

25. The device according to claim 20, wherein the control means further regulates the feed of housing gas into the inductor region in such a way that there is a pressure gradient from the housing gas arranged in the inductor region towards the ambient air arranged around the furnace housing.

26. The device according to claim 17, wherein the device further comprises a transport device for the substantially longitudinal transport of a workpiece to be inductively heated along the substantially longitudinal extent of the heating region.

27. The device according to claim 17, wherein a thermal insulation is provided between the separating material and the heating region.

28. A method for inductively heating at least one workpiece by means of a device according to claim 17, comprising the following steps: guiding a workpiece to be heated along a heating region of a furnace housing filled with a process gas; heating the workpiece by means of at least one inductor arrangement arranged in a housing gas-filled inductor region; establishing a fluidic connection between the inductor region and the heating region, in particular by means of a separating material arranged between the inductor region and the heating region; and feeding housing gas into the inductor region in such a way that there is a pressure gradient from the housing gas arranged in the inductor region towards the process gas arranged in the heating region.

29. A method according to claim 28, wherein the quantity of the housing gas to be fed in is determined as a function of the pressure difference existing between the inductor region and the heating region, and/or the quantity of the housing gas to be fed in is determined as a function of the housing gas flow occurring between the inductor region and the heating region, in particular as a function of the volume flow of the housing gas, and/or the housing gas is fed into the inductor region in such a way that the temperature, in particular the average temperature, of the housing gas in the inductor region is lower than the temperature, in particular the average temperature, of the shielding gas in the heating region.

30. The method according to claim 28, wherein before a workpiece to be heated is guided along the heating region of the furnace housing, the inductor region and the heating region are first purged by means of the housing gas; the process gas is then fed into the heating region; and preferably further housing gas is subsequently fed into the inductor region.

31. The method according to claim 28, wherein the gas mixture fed into the inductor region is such that the dew point of the housing gas arranged in the inductor region is shifted towards lower temperatures with respect to the dew point of the process gas arranged in the process region, and/or the dew point of the housing gas arranged in the inductor region is monitored essentially constantly and housing gas is fed as a function of the dew point.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The figures show:

[0040] FIG. 1 a schematic representation of a first embodiment of the device according to the invention; and

[0041] FIG. 2 a schematic representation of a second embodiment of the device according to the invention.

DESCRIPTION OF THE INVENTION

[0042] In the following description of the various embodiments according to the invention, components and elements with the same function and the same mode of operation are provided with the same reference signs, even if the components and elements may differ in their dimensions or shape in the various embodiments.

[0043] FIG. 1 shows a first embodiment of a device 2 for inductively heating at least one strip-shaped workpiece 4. The device 2 comprises a furnace housing 6 and an inductor arrangement 8 arranged inside the furnace housing 6. The inductor arrangement 8 can completely enclose the strip-shaped workpiece 4.

[0044] The inductor arrangement 8 is arranged in an inductor region 10, whereby the inductor region 10 is separated from a heating region 14 by means of separating material 12, in particular thermally. In addition to the separating material 12, thermal insulation 16 is provided between the separating material 12 and the heating region 14, wherein the separating material 12 and the thermal insulation 16 are designed in such a way that there is a fluidic connection between the inductor region 10 and the heating region 14.

[0045] For this purpose, the separating material 12 has at least one through-opening 18 for fluidic connection of the inductor region 10 and the heating region 14. In addition, the separating material 12 is designed as an at least partially permeable material, so that a fluidic exchange between the inductor region 10 and the heating region 14 can also take place away from the through opening 18.

[0046] The inductor region 10 has an inlet 20 for feeding a gas mixture, in particular housing gas, into the inductor region 10. Furthermore, a control means 22 is provided at the inlet 20, which regulates the feed of housing gas into the inductor region 10 in such a way that there is a pressure gradient from the housing gas arranged in the inductor region 10 towards the process gas arranged in the heating region 14. This makes it possible to avoid a flow of process gas arranged in the heating region 14 in the direction of the inductor region 10 or outside the furnace housing.

[0047] The inductor region 10 also has an outlet 24. By providing the outlet 24, the furnace housing 6 can be purged by means of a substantially inert gas, for example by means of the housing gas, when the device 2 is started.

[0048] Furthermore, the device has a measuring means 26 in the inductor region 10, a measuring means 28 within the heating region 14 and a further measuring means 30 on the outside of the furnace housing. The measuring means 26, 28 and 30 can, for example, be designed to measure the pressure present in the inductor region 10, in the heating region 14 and/or in the ambient air. The measuring means 26 and 28 can also be designed for measuring the dew point of the gas or gas mixture present in the inductor region 10 and/or in the heating region 14. The control means 22 can also have a measuring means for measuring the flow rate of the housing gas fed in.

[0049] FIG. 2 shows a schematic side view of a second embodiment of the device 2 according to the invention. In contrast to the embodiment of the device 2 shown in FIG. 1, the separating material 12 is designed as thermal insulation, the separating material 12 having through openings 18 for establishing a fluidic connection between the inductor region 10 and the heating region 14. At the start of a heating treatment, the air arranged in the furnace housing 6 can be displaced, for example by inert gas, by means of the inlet 20. The inductor region 10 and the heating region 14 can therefore be purged. This can prevent the process gas subsequently introduced into the inductor region 10 and the heating region 14 from reacting with residual air concentrations within the furnace housing 6.

LIST OF REFERENCES

[0050] 2 Device [0051] 4 Workpiece [0052] 6 Furnace housing [0053] 8 Inductor arrangement [0054] 10 Inductor region [0055] 12 Separation material [0056] 14 Heating region [0057] 16 Thermal insulation [0058] 18 Through-opening [0059] 20 Inlet [0060] 22 Control means [0061] 24 Outlet [0062] 26 Measuring equipment for the inductor region [0063] 28 Measuring equipment for the heating region [0064] 30 Measuring equipment for the ambient air