Heating assembly for an industrial furnace

Abstract

The invention relates to a heating assembly (16) for an industrial furnace (10) and comprising a radiant housing (18) extending along a first main axis (23) in the industrial furnace (10) and supported by a first support (26) and a second support (27), and an electrical heating insert (60) extending along a second main axis (61) and arranged in the radiant housing (18), wherein the radiant housing (18) is configured for operating in a plurality of angular positions relative to the first main axis (23), and wherein the first support (26) and the second support (27) comprise supporting means (30) for allowing a rotation of the radiant housing (18) around the first main axis (23) during a maintenance operation in order to compensate for previous deformation of the radiant housing (18) and therefore extend the service life of the radiant housing (18).

Description

Heating assembly for an industrial furnaceTechnical field of the invention

[0001] The invention pertains to the field of industrial furnaces for the production of metal products and in particular steel products.Background of the invention

[0002] Industrial furnaces are used for the manufacture of metal products. Such furnaces allow the heat treatment of metal strips, preferably steel strips, and in particular the continuous heat treatment of steel strips. In a continuous line for the heat treatment of steel strips, said strips are conveyed past radiant housings.

[0003] A radiant housing operated in an industrial furnace may undergo deformation such as bending due to creep and / or fatigue, which may shorten its service life and even ultimately lead to the destruction of the radiant housing. Said deformation may be progressive, for instance when due to creep and / or fatigue, or sudden, for instance in the case of a prevented deformation of a stuck mechanical part. More precisely, a straight radiant housing operated in an industrial furnace may progressively deform due to creep and / or fatigue, which may shorten its service life.

[0004] Therefore, there is a need for extending the service life of a radiant housing operated in an industrial furnace.Disclosure of the invention

[0005] To this end, the invention provides a heating assembly for an industrial furnace and comprising: a first furnace wall portion and a second furnace wall portion facing each other, said wall portions delimiting an inner volume of the heating assembly; a radiant housing for heating the inner volume, the radiant housing extending along a first main axis and comprising a first end and a second end, the first main axis extending between said wall portions; an electrical heating insert extending along a second main axis and arranged in the radiant housing; a first support for supporting the first end of the radiant housing, said first support being arranged on one of the furnace wall portions; a second support for supporting the second end of the radiant housing, said second support being arranged on one of the furnace wall portions;wherein the radiant housing is configured for operating in a plurality of angular positions relative to the first main axis, and wherein the first support and the second support comprise supporting means for allowing a rotation of the radiant housing around the first main axis during maintenance, with said radiant housing resting on said first and second supports.In an embodiment, at least one of said first and second supports further comprise blocking means for preventing rotation of the radiant housing around the first main axis during operation.In an embodiment, said supporting means are further configured for allowing a translation of the radiant housing along the first main axis.In an embodiment, the first support further comprises a stop for limiting the translation of the radiant housing along the first main axis during maintenance.In an embodiment, the radiant housing is configured to be rotated around the first main axis by an angle comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°, even more preferably substantially equal to 180°.In an embodiment, the heating assembly further comprises a handle mechanically coupled to the radiant housing at least during maintenance for facilitating the rotation of the radiant housing around the first main axis.In an embodiment, the first support is configured for allowing a local rotation of the first end of the radiant housing around a first transverse axis transverse to the first main axis.In an embodiment, the first support is arranged outside the inner volume.In an embodiment, the first support further comprises compensating means for allowing a deformed radiant housing to be mechanically coupled to one of the furnace wall portions.In an embodiment, said compensating means of the first support comprise a sleeve mechanically coupled to the first end of the radiant housing and to the furnace wall portion on which the first support is arranged.In an embodiment, the first end of the radiant housing and the sleeve each comprise a flange, both flanges being configured to be bolted together for preventing rotation of the radiant housing around the first main axis during operation.In an embodiment, the first end of the radiant housing is gas-tightly sealed against the furnace wall portion on which the first support is arranged during operation.In an embodiment, the heating assembly further comprises a gasket, and the gas-tight sealing between the first end of the radiant housing and the furnace wall portion on which the first support is arranged is ensured by said gasket being arranged between the flange of the first end of the radiant housing and the flange of the sleeve.In an embodiment, the second support is configured for allowing a local rotation of the second end of the radiant housing around a second transverse axis transverse to the first main axis.In an embodiment, the second support is arranged inside the inner volume and is mechanically coupled to one of the furnace wall portions through a socket.In an embodiment, the second support is configured for supporting a plurality of radiant housings from said socket, each radiant housing in the plurality extending along a respective main axis, and each radiant housing in the plurality being rotatable individually around its respective main axis.In an embodiment, the plurality of radiant housings are arranged in the inner volume along an axis transverse to their respective main axes.In an embodiment, the radiant housing is movable along the first main axis in sliding friction relative to the second support.In an embodiment, the second support further comprises a pad for preventing sticking of the second end of the radiant housing to the second support.In an embodiment, the electrical heating insert comprises an electrical heating conductor and at least one support element for supporting the electrical heating conductor, the at least one support element being made of a heat-resistant and electrically insulating material, the electrical heating conductor being electrically insulated from the radiant housing.In an embodiment, the electrical heating insert is configured for operating in a plurality of angular positions relative to the second main axis.In an embodiment, an envelope of the electrical heating insert is substantially cylindrical in shape and has a uniform cross-section along the second main axis.In an embodiment, the electrical heating insert is configured for being inserted into or removed from the radiant housing.In an embodiment, the first end of the radiant housing is configured for allowing the insertion of a measuring device through said first end for measuring a physical property of the inner volume.In an embodiment, the measuring device is a thermocouple for measuring a temperature of the inner volume.In an embodiment, the first end of the radiant housing is configured for allowing the insertion of a measuring device through said first end for measuring a physical property of an interior volume of the radiant housing.In an embodiment, the measuring device is a thermocouple for measuring a temperature of the interior volume.In an embodiment, the radiant housing is substantially cylindrical in shape.In an embodiment, the first end of the radiant housing is an open end.In an embodiment, said open end is configured for allowing the insertion of the electrical heating insert into the radiant housing.In an embodiment, the radiant housing is made of steel.In an embodiment, a surface of the radiant housing is not smooth.The invention also relates to a furnace comprising a heating assembly according to the invention.The invention also relates to a use of a heating assembly according to the invention for a heat treatment of a steel product.The invention also relates to a maintenance operation for a heating assembly according to the invention and comprising the following step:(d) rotating the radiant housing by an angle of rotation around the first main axis while the radiant housing is supported by the first support and the second support.In an embodiment, the angle of rotation is comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°, even more preferably substantially equal to 180°.In an embodiment, the maintenance operation further comprises the following steps:(c) translating the radiant housing along the first main axis for separating the first end of the radiant housing from the blocking means preventing rotation of the radiant housing around the first main axis, while the radiant housing is supported by the first support and the second support;(e) translating the radiant housing along the first main axis for joining the first end of the radiant housing with the blocking means preventing rotation of the radiant housing around the first main axis, while the radiant housing is supported by the first support and the second support.In an embodiment, the maintenance operation further comprises the following steps:(b) releasing the blocking means preventing rotation of the radiant housing around the first main axis;(f) reinstalling the blocking means for preventing rotation of the radiant housing around the first main axis.In an embodiment, the maintenance operation further comprises the following steps:(a) removing the electrical heating insert from the radiant housing before the rotation of the radiant housing performed in step (d);(g) inserting the electrical heating insert into the radiant housing after the rotation of the radiant housing performed in step (d).In an embodiment, the maintenance operation is performed once a certain amount or threshold of deformation of the radiant housing has been reached.In an embodiment, the amount or threshold of deformation of the radiant housing for performing the maintenance operation is measured by a local rotation of the first end of the radiant housing around a first transverse axis transverse to the first main axis.

[0006] Rotating a radiant housing around its main axis allows creep and / or fatigue to be exerted in another direction, thereby at least partially compensating for previous deformation of the radiant housing caused by creep and / or fatigue and therefore extending the service life of the radiant housing.

[0007] In the framework of this document, the use of the indefinite article “a”, “an” or the definite article “the” to introduce an element does not exclude the presence of a plurality of such elements. In this document, the terms “first”, “second”, “third” and the like are solely used to differentiate elements and do not imply any order in these elements. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

[0008] In the framework of this document, the use of the verbs “comprise”, “include”, “involve” or any other similar variant, as well as their conjugational forms, cannot exclude the presence of elements other than those mentioned. When the verb “comprise” is used for defining an interval by the terms “comprised between” two values, these two values should not be interpreted as excluded from the interval.

[0009] All the possible embodiments of the heating assembly according to the invention and the advantages of these embodiments apply mutatis mutandis to the present use of a heating assembly and maintenance operation for a heating assembly according to the invention, and vice versa.Brief description of the figures

[0010] For a better understanding of the features and advantages of the present invention, reference will now be made, by way of example, to the accompanying drawings in which:Fig. 1 represents an industrial furnace;Fig. 2 represents a heating assembly;Fig. 3 represents a deformed radiant housing in a heating assembly;Fig. 4 represents a maintenance operation;Fig. 5 represents a support for a radiant housing;Fig. 6 represents a heating assembly with a deformed radiant housing;Fig. 7 represents a gasket;Fig. 8 represents a heating assembly with a plurality of radiant housings;Fig. 9 represents a radiant housing;Fig. 10 represents an electrical heating insert;Fig. 11 represents an electrical heating insert in a radiant housing;Fig. 12 represents a set comprising a tool for manipulating an electrical heating insert arranged in a radiant housing;Fig. 13 represents a set comprising a tool for manipulating an electrical heating insert arranged in a radiant housing;Fig. 14 represents a set comprising a tool for manipulating an electrical heating insert arranged in a radiant housing;Fig. 15 represents an electrical heating insert according to the prior art arranged in a radiant housing;Fig. 16 represents a deficiency of the prior art after a rotation of the electrical heating insert of Fig. 15 around a main axis;Fig. 17 represents an electrical heating device comprising an electrical heating insert arranged in a radiant housing;Fig. 18 represents an electrical heating insert;Fig. 19 represents an electrical heating device with a heat barrier;Fig. 20 represents a support element of an electrical heating insert;Fig. 21 represents a support element of an electrical heating insert;Fig. 22 represents a support element of an electrical heating insert;Fig. 23 represents a support element of an electrical heating insert;Fig. 24 represents a support element of an electrical heating insert;Fig. 25 represents a support element of an electrical heating insert.

[0011] The figures are not drawn to scale. Similar elements may be assigned similar references in the figures. In the framework of the present document, identical or analogous elements may have the same references. The presence of reference numbers in the drawings cannot be considered to be limiting, in particular if these numbers are indicated in the claims.Detailed description of some embodiments

[0012] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto. The described functions are not limited by the described structures. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. Furthermore, embodiments referred to as “preferred” are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.

[0013] An industrial furnace may be used to process metal sheets, plates, or slabs, for example up to 120mm thick. An industrial furnace may also be used to process metal strips. The metal strips may be continuous strips, for example with a length comprised between 1 ,5km and 13km. In particular, the sheets, plates, slabs, or strips may be made of steel. Fig. 1 shows an industrial furnace 10 comprising a furnace chamber 11 for processing metal strips and in particular steel strips. In the following, reference will be made to steel strips 12, but the description of the invention also applies to metal or steel sheets, plates, or slabs.

[0014] The strip 12 travels in the furnace 10 while being driven by rollers 14. The strip 12 is conveyed in the furnace chamber 11 in front of heating assemblies 16 in multiple vertical passes thanks to the rollers 14, which enables a more compact configuration of the furnace 10 as compared to a furnace 10 with a single (horizontal) pass of the strip 12 in front of heating assemblies 16. An example of a heating assembly 16 is represented schematically in Fig. 2. The heating assembly 16 comprises an inner volume 20 delimited between a first furnace wall portion 21 and a second furnace wall portion 22. The first wall portion 21 and the second wall portion 22 face each other. A first main axis 23 extends between the first and second wall portions 21, 22. Preferably, the first main axis 23 is transverse (or normal, or perpendicular) to the first and second wall portions 21, 22. Preferably, the first and second wall portions 21 , 22 are covered with refractory insulation 25. The inner volume 20 of the heating assembly 16 is comprised in the furnace chamber 11 of the industrial furnace 10.

[0015] The heating assembly 16 also comprises at least one radiant housing 18 for radiantly heating the inner volume 20 of the heating assembly 16. The radiant housing 18 extends along the first main axis 23 and comprises a first end 181 and a second end 182. By extending along the first main axis 23, the radiant housing 18 is rectilinear. Preferably, the radiant housing 18 extends substantially horizontally in the inner volume 20. The heatingassembly 16 may comprise one or more radiant housings 18. In an embodiment, the heating assembly 16 comprises a single radiant housing 18. In another embodiment, the heating assembly 16 comprises a plurality of radiant housings 18. More generally, the heating assembly 16 may comprise all the radiant housings 18 of a column of radiant housings 18 past which the steel strip 12 is conveyed in the furnace chamber 11. In other words, the strip 12 is conveyed in the inner volume 20, between the first and second wall portions 21 , 22, facing one or more radiant housings 18. In this configuration, the strip 12 is radiantly heated by the radiant housings 18.

[0016] The heating assembly 16 further comprises an electrical heating insert 60. The electrical heating insert 60 may also be referred to herein as a resistive insert. The electrical heating insert 60 extends along a second main axis 61 , as shown by way of example in Fig. 10. By extending along the second main axis 61 , the electrical heating insert 60 is rectilinear. The electrical heating insert 60 is arranged within the radiant housing 18, as shown by way of example in Fig. 11. The first main axis 23 of the radiant housing 18 and the second main axis 61 of the electrical heating insert 60 are substantially parallel, or even merged.

[0017] The electrical heating insert 60 provides energy for heating the radiant housing 18. The energy source used to heat the radiant housing 18 is electricity. Electricity is more environmentally friendly than hydrocarbon gas, which is traditionally used. Another advantage of using electricity for heating the radiant housing 18 is that the shape of the radiant housing 18 may be simpler. Indeed, if combustible gas is used as an energy source to heat a radiant housing, a gas inlet and a gas outlet must be provided. Possibly, a gas-powered radiant housing may comprise a general W-shape, with a gas inlet and a gas outlet at each leg of the W. A radiant housing in the shape of a W is also known as a W-shaped radiant housing. A W- shaped radiant housing is heavy and therefore difficult to handle in the furnace, for example when installing or replacing a W-shaped radiant housing. In addition, a W-shape also complicates the gas-tightness of the radiant housing in the furnace. Finally, a W-shaped radiant housing is also complex to manufacture. On the contrary, as the heating assembly 16 operates electrically, the general shape of the heating insert 60 may be greatly simplified, for example by being straight, i.e. extending along a main axis. Therefore, the general shape of the radiant housing 18 may also be greatly simplified, for example by being straight. A straight radiant housing is also known as an l-shaped radiant housing. The simplified shape of the radiant housing 18 enables a simplified maintenance operation and also simplifies the construction (or erection) of new industrial furnaces 10.

[0018] The heating assembly 16 also comprises a first support 26 for supporting the first end 181 of the radiant housing 18. The first support 26 is arranged (or in other words, fixed, positioned, placed, mounted) on one of the furnace wall portions 21 , 22. More generally, the first support 26 is mechanically coupled to one of the furnace wall portions 21 , 22. The heating assembly 16 also comprises a second support 27 for supporting the second end 182 of the radiant housing 18. The second support 27 is arranged (or in other words, fixed, positioned, placed, mounted) on one of the furnace wall portions 21, 22. More generally, the second support 27 is mechanically coupled to one of the furnace wall portions 21 , 22. A radiant housing 18 extends along a first main axis 23. Therefore, a radiant housing 18 is rectilinear, which simplifies the support of the radiant housing 18. Thus, the first and second supports 26, 27 have a simplified shape.

[0019] Herein, two working modes of the heating assembly 16 are considered: an operating mode, and a maintenance mode. The operating mode is also generally designated herein by the following expressions: “during operation”, “during operation of the radiant housing”, “during use of the radiant housing for heating the inner volume”, “during heating mode”. The maintenance mode is also generally designated herein by the following expressions: “during maintenance”, “during a maintenance operation”. The term “maintenance operation” as used herein may also be referred to as a “maintenance method” or a “maintenance process”. These terms may be used interchangeably in the description and in the claims.

[0020] The radiant housing 18 may deform during its service life due to creep and / or fatigue. In particular, the radiant housing 18 may bend under its own weight, i.e. due to gravity. More precisely, a central part of the radiant housing 18 may sag due to gravity. This deformation may shorten the service life of the radiant housing 18 and even ultimately lead to the destruction of the radiant housing 18. In order to compensate for such deformation, the radiant housing 18 may be periodically rotated around the first main axis 23 during a maintenance operation, thereby extending the service life of the radiant housing 18.

[0021] The maintenance operation of the heating assembly 16 comprises a rotation of the radiant housing 18 around the first main axis 23 in order to compensate for previous deformation of the radiant housing 18 and therefore extend the service life of the radiant housing 18. In particular, the maintenance operation of the heating assembly 16 may be performed with an electrical heating insert 60 arranged in or on the radiant housing 18. Said maintenance operation may also be performed with no electrical heating insert 60 arranged in or on the radiant housing 18. Therefore, the maintenance operation of the heating assembly16 may comprise a removal of an electrical heating insert 60 from the radiant housing 18. The maintenance operation of the heating assembly 16 may also comprise an insertion of an electrical heating insert 60 into the radiant housing 18, including when the insert 60 is inserted into the housing 18 for the first time.

[0022] The radiant housing 18 is configured for operating in a plurality of angular positions relative to the first main axis 23. The angular position of such a radiant housing 18 relative to the first main axis 23 may be changed during a maintenance operation in which the radiant housing 18 is rotated around the first main axis 23. In other words, the ability of the radiant housing 18 to operate in a plurality of angular positions relative to the first main axis 23 allows the radiant housing 18 to be rotated around the first main axis 23, for example during a maintenance operation. The radiant housing 18 may be rotated around the first main axis 23 with or without the electrical heating insert 60 inside it. In addition, the radiant housing 18 is configured to be rotated around the first main axis 23 independently of the angular position of the electrical heating insert 60 relative to the second main axis 61. Therefore, the relative angular position of the radiant housing 18 and the electrical heating insert 60 around their respective main axes 23, 61 may vary.

[0023] A radiant housing 18 having some degree of symmetry around the first main axis 23 is configured for operating in a plurality of angular positions relative to the first main axis 23. For example, a radiant housing 18 with a square cross-section with respect to the first main axis 23 is configured for operating in a plurality of angular positions relative to the first main axis 23. Another example is a radiant housing 18 with an hexagonal cross-section with respect to the first main axis 23, or an octagonal cross-section, or a circular cross-section. In particular, a radiant tube, i.e. a radiant housing 18 having a circular cross-section with respect to the first main axis 23, is an example of a radiant housing 18 configured for operating in a plurality of angular positions relative to the first main axis 23. Other examples, and in particular radiant housings 18 with cross-sections of different shapes, are possible.

[0024] The first support 26 and the second support 27 each comprise supporting means 30 for supporting the radiant housing 18 during operation and during maintenance. Supporting means 30 hold the radiant housing 18 in place so that the strip 12 is conveyed facing the radiant housing 18 during operation. Supporting means 30 allow a rotation of the radiant housing 18 around the first main axis 23 during maintenance, with the radiant housing 18 resting on the first and second supports 26, 27. In particular, supporting means 30 allow the weight of the radiant housing 18 and its components such as the electrical heating insert 60 to be supported during maintenance, such that the radiant housing 18 may be rotated around thefirst main axis 23 while resting on said first and second supports 26, 27. The supporting means 30 may comprise for instance a bearing 31 , or one or more rollers, or one or more balls, or any kind of mechanical device allowing the weight of the radiant housing 18 and its components to be supported while the radiant housing 18 is rotated around the first main axis 23. A support 27 comprising a bearing 31 able to act as a supporting means 30 is represented by way of example in Fig. 5.

[0025] Supporting means 30 allow a maintenance operation to be carried out easily to extend the service life of the radiant housing 18. More precisely, supporting means 30 allow the radiant housing 18 to be rotated around the first main axis 23 periodically during a maintenance operation, for example every 3 months, every 6 months, every year, or every two years. Fig. 3 and Fig. 4 schematically illustrate the maintenance operation performed on a heating assembly 16 comprising a deformed radiant housing 18. Said maintenance operation may be performed individually on a single radiant housing 18, or on a plurality of radiant housings 18. It is also recalled that the heating assembly 16 may generally comprise a single radiant housing 18, or a plurality of radiant housings 18. The maintenance operation shown in Fig. 3 and Fig. 4 is for illustrative purposes only and should not be interpreted in such a way as to limit the scope of the invention.

[0026] In Fig. 3, the radiant housing 18 is deformed, and more precisely bent, by creep and / or fatigue over its lifetime. In particular, the central part of the radiant housing 18 tends to sag, as represented in dashed lines in Fig. 3. This may contribute to deformation and / or breakage of an electrical heating insert 60 comprised in the radiant housing 18. More generally, the deformation of a radiant housing 18 may shorten its service life and even ultimately lead to the destruction of the radiant housing 18. In Fig. 4, the deformed radiant housing 18 is rotated around the first main axis 23 according to arrows 32 by an angle comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°, even more preferably substantially equal to 180°. The radiant housing 18 is rotated while resting on the first and second supports 26, 27, as enabled by the supporting means 30. Rotation of the radiant housing 18 allows creep and / or fatigue to be exerted in another direction, thereby at least partially compensating for previous deformation of the radiant housing 18 caused by creep and / or fatigue and therefore extending the service life of the radiant housing 18. Preferably, the angle of rotation of the radiant housing 18 around the first main axis 23 is substantially equal to 180°, which compensates for previous deformation of the radiant housing 18 caused by creep and / or fatigue and therefore extends the service life of the radiant housing 18.

[0027] Extending the service life of the radiant housing 18 has several advantages. First, it reduces a maintenance cost of a furnace 10 comprising the radiant housing 18. Second, it is beneficial for the environment since the radiant housing 18 needs to be replaced less often. Third, it facilitates a periodical maintenance operation of the furnace 10, such as a yearly maintenance, by reducing a number of damaged radiant housings 18 to be replaced during said maintenance operation.

[0028] The heating assembly 16 may further comprise a handle mechanically coupled to the radiant housing 18 at least during maintenance for facilitating the rotation of the radiant housing 18 around the first main axis 23.

[0029] At least one of the first and second supports 26, 27 may further comprise blocking means for preventing rotation of the radiant housing 18 around the first main axis 23. Especially, the blocking means prevent rotation of the radiant housing 18 around the first main axis 23 during operation, i.e. during use of the radiant housing 18 for heating the inner volume 20. In other words, the blocking means ensure that the angular position of the radiant housing 18 around the first main axis 23 does not change during operation. One or both of the first and second supports 26, 27 may comprise said blocking means. The blocking means are preferably removable so that they may be easily installed and removed. By way of example, the blocking means may comprise nuts and bolts that may be fastened during operation and released during maintenance. For example, the blocking means may be installed in a flange 40 of a first end 181 of the radiant housing 18. Other examples of blocking means are a keyway and a key, or a mortise and a tenon, or a pin. Other blocking means are possible.

[0030] The supporting means 30 of the first and second supports 26, 27 for supporting the radiant housing 18 may be further configured for allowing a translation of the radiant housing 18 along the first main axis 23. Such a translation may occur during operation, for instance due to thermal expansion of the radiant housing 18, or during maintenance. A translation of the radiant housing 18 on the supporting means 30 may facilitate a maintenance operation by allowing an end 181 , 182 of the radiant housing 18 to be slightly separated from one of the furnace wall portions 21, 22 while the radiant housing 18 continues to be supported by the first and / or second supports 26, 27 such as to allow an easier rotation of the radiant housing 18 around the first main axis 23 during maintenance. Said translation may also facilitate the construction (or erection) or the revamping of the furnace 10 by allowing the radiant housing 18 to be installed on the first and / or second supports 26, 27 in a temporary position close to a final position, with the radiant housing 18 being already supported by thefirst and / or second supports 26, 27 in the temporary position. Said translation therefore allows the radiant housing 18 to be inserted into or removed from the furnace 10 in a simpler manner.

[0031] The first support 26 may comprise a stop 50 for limiting the translation of the radiant housing 18 along the first main axis 23. This prevents the radiant housing 18 from falling due to the translation during operation or during maintenance. Such a stop 50 is represented in the figures by way of example, for instance in Fig. 2 and Fig. 6.

[0032] The first support 26 and the second support 27 may be arranged on either the first wall portion 21 or the second wall portion 22. It is possible that all the first supports 26 are arranged on the first wall portion 21 and all the second supports 27 are arranged on the second wall portion 22. Preferably, the first support 26 and the second support 27 are alternately arranged on the first wall portion 21 and the second wall portion 22 for adjacent heating assemblies 16. In other words, the first supports 26 are alternately arranged on the first wall portion 21 and then on the second wall portion 22 and the second supports 27 are arranged on the other wall portion. This provides more space outside the furnace 10, particularly for a maintenance operation.

[0033] The heating assembly 16 may be comprised in an industrial furnace 10. In this case, the inner volume 20 of the heating assembly 16 is comprised in a furnace chamber 11 of the industrial furnace 10.

[0034] The heating assembly 16 may be used for a heat treatment of a steel product. A steel product may be for instance a steel sheet, a steel plate, a steel slab, or a steel strip.First support

[0035] The first support 26 may be arranged outside the inner volume 20. The first support 26 arranged outside the inner volume 20 allows one or more radiant housings 18 to be handled from outside the inner volume 20. The first support 26 is visible outside the inner volume 20 in some figures, for example in Fig. 2 and Fig. 6. The first support 26 allows one or more radiant housings 18 to be supported outside the inner volume 20.

[0036] The first support 26 may be configured for allowing a local rotation of the first end 181 of the radiant housing 18 around a first transverse axis 36 transverse to the first main axis 23. The local rotation may be due to a deformation of the housing 18. For instance, the local rotation may occur during operation, i.e. during use of the radiant housing 18 for heating the inner volume 20. The first transverse axis 36 is preferably substantially horizontal. The first transverse axis 36 is preferably perpendicular to the first main axis 23 in a horizontal plane comprising the first main axis 23. The first end 181 of the radiant housing 18 may locally rotatearound the first transverse axis 36 due to a deformation of the radiant housing 18 caused by creep and / or fatigue, said deformation being for example a bending of the radiant housing 18. This is represented by way of example in Fig. 6, which schematically represents a heating assembly 16 comprising a deformed radiant housing 18. The radiant housing 18 of Fig. 6 is deformed due to creep and / or fatigue. In particular, the radiant housing 18 of Fig. 6 is bent due to creep and / or fatigue. By way of example, the first end 181 of the radiant housing 18 may locally rotate around the first transverse axis 36 by 1.5° when the radiant housing 18 is deformed.

[0037] The first support 26 may comprise compensating means 34 for allowing a deformed radiant housing to be mechanically coupled to one of the furnace wall portions 21, 22. The compensating means 34 compensate for deformation of the radiant housing 18 along the first transverse axis 36. Indeed, although the radiant housing 18 is periodically rotated in a maintenance operation, deformation of the radiant housing 18 due to creep and / or fatigue may occur between two maintenance operations. Locally, the first end 181 undergoes a rotation around the first transverse axis 36, when the radiant housing 18 (and in particular the central zone of the radiant housing 18) deforms. An advantage of the compensating means 34 is that a deformed radiant housing 18 may be maintained in position in the first support 26 during operation. By way of example, the first end 181 of the radiant housing 18 may locally rotate around the first transverse axis 36 by 1.5° when the radiant housing 18 is deformed. Another advantage of the compensating means 34 is that said compensating means 34 may allow a deformed radiant housing 18 to be mechanically coupled to one of the furnace wall portions 21 , 22 during a maintenance operation. Yet another advantage of the compensating means 34 is to allow the deformation of the radiant housing 18 to be monitored from outside the furnace chamber 11. Indeed, as the radiant housing 18 deforms during its service life, the first end 181 of the radiant housing 18 may locally rotate around the first transverse axis 36. This is visible and may thus be monitored from outside the furnace chamber 11. The compensating means 34 may therefore act as a gauge of the deformation of the radiant housing 18. In turn, the maintenance operation may be performed once a certain amount or threshold of deformation of the radiant housing 18 has been reached, as indicated or measured via the deformation gauge. Said amount of deformation may be for instance a local rotation of the first end 181 of the radiant housing 18 around the first transverse axis 36 by 1.5°.

[0038] The compensating means 34 of the first support 26 may comprise a sleeve 35 mechanically coupled to the first end 181 of the radiant housing 18 and to the furnace wall portion 21, 22 on which the first support 26 is arranged. The sleeve 35 may be a cylindricaldevice extending along an axis, for instance along the first main axis 23 of the radiant housing 18. The sleeve 35 may be flexible such as to allow a deformation of the radiant housing 18 and in particular a rotation of the first end 181 of the radiant housing 18 around the first transverse axis 36 transverse to the first main axis 23. Generally, the sleeve 35 being flexible, it may adapt to any deformation of the radiant housing 18. In particular, the sleeve 35 may also allow a thermal expansion of the radiant housing 18. Preferably, the sleeve 35 is a corrugated sleeve comprising a bellow. The sleeve 35 may also be referred to herein as a compensator. The sleeve 35 is mechanically coupled to the first end 181 of the radiant housing 18 and to one of the furnace wall portions 21, 22. The sleeve 35 may be attached to either of these, even though the two ends of the sleeve 35 are not aligned, for instance in the case of a deformed radiant housing 18. Such a sleeve 35 is represented by way of example in Fig. 2 and Fig. 6. The sleeve 35 as represented in Fig. 2 and Fig. 6 is a corrugated sleeve surrounding the end 181 of a radiant housing 18. In Fig. 6, the sleeve 35 allows a deformed radiant housing 18 to be maintained in position in the first support 26 during operation.

[0039] The first end 181 of the radiant housing 18 and the sleeve 35 may each comprise a flange 40, 42, both flanges 40, 42 being configured to be bolted together for preventing rotation of the radiant housing 18 around the first main axis 23 during operation, thereby acting as a blocking means as described hereinabove. In the figures, the flange of the first end 181 of the radiant housing 18 is designated by reference 40 and the flange of the sleeve 35 is designated by reference 42. During operation of the heating assembly 16, fastening flanges 40, 42 together prevents rotation of the radiant housing 18 around the first main axis 23. This allows the radiant housing 18 to keep the same angular position relative to the first main axis 23 during operation. This also allows the angular position of the radiant housing 18 to be controlled between two maintenance operations. This further allows the change in angular position of the radiant housing 18 relative to the first main axis 23 to be controlled during maintenance.

[0040] The first end 181 of the radiant housing 18 may be gas-tightly sealed against one of the furnace wall portions 21 , 22 during operation, i.e. during use of the radiant housing 18 for heating the inner volume 20. In other words, the first end 181 of the radiant housing 18 may be gas-tightly sealed during operation against the furnace wall portion 21 , 22 on which the first support 26 is arranged. This ensures that the atmosphere present in the inner volume 20, e.g. a reducing atmosphere, does not escape out of the inner volume 20.

[0041] More specifically, the heating assembly 16 may comprise a gasket 44. The gastight sealing between the first end 181 of the radiant housing 18 and one of the furnace wallportions 21 , 22 is ensured by the gasket 44 being arranged between the flange 40 of the first end 181 of the radiant housing 18 and the flange 42 of the sleeve 35. Preferably, the gasket 44 is compressed between said flanges 40, 42. In order to allow the gasket 44 to be replaced without having to remove the radiant housing 18 from the furnace 10, the gasket 44 may comprise at least two parts 441, 442, etc. In other words, the gasket 44 may comprise a plurality of parts 441 , 442, etc. The plurality of parts allows the gasket 44 to be replaced without having to put it onto the radiant housing 18 from one of its ends 181 , 182 and therefore without having to remove the radiant housing 18 from the furnace 10. The gasket 44 comprises at least two parts which can be removed by loosening the coupling between the flanges 40, 42. Fig. 7 schematically represents an example of a gasket 44. In the example of Fig. 7, the gasket 44 comprises two parts 441 , 442. Each part 441 , 442 makes a circular arc around the radiant housing 18, for example 180° in the case of two parts. Several shapes are possible for the junction between the two parts 441, 442 of the gasket 44. In the example of Fig. 7, it may be a bulge projecting from part 442 and matching the shape of a concavity in part 441. An alternative solution to the multi-part gasket 44 is to make the gas-tight seal by means of a cord made of a fibrous material resistant to high temperatures, which may also be referred to as a flexible rope gasket 44. A flexible rope gasket 44 may be replaced without having to remove the radiant housing 18 from the furnace 10.Second support

[0042] The second support 27 may be configured for allowing a local rotation of the second end 182 of the radiant housing 18 around a second transverse axis 38 transverse to the first main axis 23. The local rotation may be due to a deformation of the housing 18. For instance, the local rotation may occur during operation, i.e. during use of the radiant housing 18 for heating the inner volume 20. The second transverse axis 38 is preferably substantially horizontal. The second transverse axis 38 is preferably perpendicular to the first main axis 23 in a horizontal plane comprising the first main axis 23. The second end 182 of the radiant housing 18 may locally rotate around the second transverse axis 38 due to a deformation of the radiant housing 18 caused by creep and / or fatigue, said deformation being for example a bending of the radiant housing 18. This is represented by way of example in Fig. 6, which schematically represents a heating assembly 16 comprising a deformed radiant housing 18. The radiant housing 18 of Fig. 6 is deformed due to creep and / or fatigue. In particular, the radiant housing 18 of Fig. 6 is bent due to creep and / or fatigue. Indeed, although the radiant housing 18 is periodically rotated in a maintenance operation, deformation of the radianthousing 18 due to creep and / or fatigue may occur between two maintenance operations. Locally, the second end 182 undergoes a rotation around the second transverse axis 38, when the radiant housing 18 (and in particular the central zone of the radiant housing 18) deforms. By way of example, the second end 182 of the radiant housing 18 may locally rotate around the second transverse axis 38 by 1.5° when the radiant housing 18 is deformed. An advantage of allowing a local rotation of the second end 182 of the radiant housing 18 around the second transverse axis 38 is to allow the radiant housing 18 to deform while continuing to be supported by the second support 27. Another advantage is to allow the radiant housing 18 to deform without being overly constrained in the second support 27.

[0043] The second support 27 may be arranged inside the inner volume 20. In addition, the second support 27 may be mechanically coupled to one of the furnace wall portions 21 , 22 through a socket 46. The second support 27 arranged inside the inner volume 20 allows the second end 182 of the radiant housing 18 to be installed more easily into the furnace 10. In addition, the socket 46 may be already present in the furnace 10, for instance in the case of a revamping of the furnace 10, in which case the second support may be mechanically coupled to one of the furnace wall portions 21, 22 through an existing socket 46. The second support 27 is visible inside the inner volume 20 in some figures, for example in Fig. 2 and Fig. 6. The socket 46 is not part of the support 27.

[0044] Generally, the second support 27 may be coupled to one of the furnace wall portions 21 , 22 through one or more sockets 46. In an embodiment, the second support 27 is coupled to one of the furnace wall portions 21 , 22 through a single socket 46. In another embodiment, the second support 27 is coupled to one of the furnace wall portions 21 , 22 through a plurality of sockets 46.

[0045] The second support 27 may be configured for supporting a plurality of radiant housings 18 from the socket 46. More precisely, the second support 27 may be configured for supporting a plurality of radiant housings 18 while being mechanically coupled to one of the furnace wall portions 21, 22 through the socket 46. In this case, each radiant housing 18 in the plurality extends along a respective main axis 23. In addition, each radiant housing 18 in the plurality is rotatable individually around its respective main axis 23, i.e. independently of the configuration of the other radiant housings 18 in the plurality or, more precisely, independently of the angular position of the other radiant housings 18 in the plurality relative to their respective main axes 23. In the case of a revamping of the furnace 10, it is advantageous to support a plurality of radiant housings 18 from one or more existing sockets 46 so as to avoid having to install new sockets inside the furnace 10. Indeed, installing a new socket on a furnace wallmay be complex, especially if the new socket must be installed in the refractory insulation of the furnace wall. An advantage of supporting a plurality of radiant housings 18 from a reduced number of sockets 46 or even from a single socket 46 is to limit the number of sockets 46 within the furnace 10.

[0046] Preferably, the plurality of radiant housings 18 are arranged in the inner volume 20 along an axis 28 transverse to their respective main axes 23. In this case, the plurality of radiant housings 18 are preferably arranged vertically, or in other words on top of each other, in the inner volume 20. Such an arrangement is shown by way of example in Fig. 8, which schematically represents a front view of a heating assembly 16 comprising a plurality of radiant housings 18 arranged along an axis 28 transverse to the respective main axes 23 of the radiant housings 18.

[0047] In an embodiment, the radiant housing 18 is movable along the first main axis 23 in sliding friction relative to the second support 27. Herein, sliding friction, also known as kinetic friction, designates a relative displacement between two objects in contact with each other wherein one object slides on the other, as opposed to rolling friction for instance, which designates a relative displacement between two objects in contact with each other wherein one object rolls on the other. In this embodiment, the radiant housing 18 may move relative to the second support 27 in sliding friction, i.e. by sliding on the second support 27. An advantage of this embodiment is to allow thermal expansion of the radiant housing 18 to be accommodated during operation. Another advantage of this embodiment is to facilitate the manipulation of a radiant housing 18 during maintenance.

[0048] Preferably, the second support 27 comprises a pad 48 for preventing sticking of the second end 182 of the radiant housing 18 to the second support 27, in particular during operation. The pad 48 is placed between the second end 182 of the radiant housing 18 and a supporting means 30 of the second support 27, as illustrated by way of example in Fig. 2 and Fig. 6.

[0049] Generally, the first support 26 and the second support 27 must be interpreted broadly as comprising all types of coupling means described herein: supporting means and blocking means. In addition, the first support may comprise compensating means.Electrical heating insert

[0050] The electrical heating insert 60 may comprise an electrical heating conductor 62. The electrical heating conductor 62 may have for example the shape of one or more bars, or one or more rods, or also have a helical shape. Other shapes of the electrical heatingconductor 62 are possible. The electrical heating conductor 62 may also be referred to herein as an electrical heating resistor, or simply an electrical resistor. The electrical heating conductor 62 may be made of an electrically conductive material such as for example: a nickel- chromium-based alloy (NiCr alloy) suitable for use at temperatures up to 1250°C; a ferritic iron- chromium-aluminium-based alloy (FeCrAI alloy) suitable for use at temperatures up to 1425°C, which combines excellent resistance to oxidation and hot corrosion with high creep resistance and superior form stability; a ceramic material such as silicon carbide (SiC) suitable for use at temperatures comprised between 600°C and 1600°C, or molybdenum disilicide (MoSi2).

[0051] The electrical heating insert 60 may also comprise at least one support element 64 for supporting the electrical heating conductor 62. The at least one support element 64 may be made of a heat-resistant and electrically insulating material such as a ceramic material. The support element 64 may have several functions. A first function of the support element 64 is to support the electrical heating conductor 62. In this regard, the electrical heating conductor 62 may be supported for example in one or several holes or bores of the support element 64, or in one or several brackets of the support element 64, or also wrapped around the support element 64. For example, the electrical heating conductor 62 may be helically wrapped around one or more bars of the support element 64. In addition, the support element 64 may be used as a spacer between different parts of the electrical heating conductor 62. The support element 64 may also be referred to herein as a resistor spacer. A second function of the support element 64 is to support the electrical heating insert 60 when the insert 60 is placed in or on a radiant housing 18. When the insert 60 is placed in or on a radiant housing 18, the electrical heating conductor 62 is preferably electrically insulated from the radiant housing 18, more precisely from a wall 24 of the radiant housing 18 on which the insert 60 is supported, thanks to the at least one support element 64.

[0052] Preferably, the electrical heating insert 60 is flexible and is configured to be supported within the radiant housing 18. The insert 60 being “flexible” means that the insert 60 may deform. In particular, the insert 60 may deform with the radiant housing 18 in which the insert 60 is supported. In other words, the insert 60 is preferably not rigid nor self-supporting. A “self-supporting” structure as used herein is a structure that maintains its shape when placed on a surface or when supported by two points. In other words, a “self-supporting” structure as used herein is a structure that keeps its shape when it rests on a surface or when it rests only on two supports.

[0053] In an embodiment, the electrical heating insert 60 comprises a plurality of support elements 64 for supporting the electrical heating conductor 62. The plurality of supportelements 64 may be mechanically coupled to a support bar 68. The support bar 68 may occupy a central position in the electrical heating insert 60, for instance along the second main axis 61 of the electrical heating insert 60, in which case the support bar 68 may be called a central support bar. The support bar 68 may be made of a heat-resistant material such as refractory steel. The support bar 68 may be protected by a sheath 69. The sheath 69 may have the shape of one or more hollow cylinders, or one or more sleeves, such that it may be put on, or in other words slipped over, the support bar 68. The sheath 69 may be made of a refractory material such as a ceramic material. The sheath 69 protects the support bar 68 from the heat emitted by the electrical heating conductor 62.

[0054] The electrical heating insert 60 may further comprise a heat stopper 66. The heat stopper 66 may have the shape of a cylinder. The heat stopper 66 may be made of a refractory material. Said refractory material may be rigid or flexible. A rigid refractory material may be for example a ceramic material, or a material comprising compressed refractory fibers. A flexible refractory material may be for example a fibrous material such as glass wool or rock wool. Generally, the heat stopper 66 may be made of a different material from the material of the support element 64. The “heat stopper” 66 may also be referred to herein as a “bung”, a “bung heat stopper”, a “plug”, or a “thermal plug”. These terms may be used interchangeably in the description and in the claims. When the electrical heating insert 60 is arranged in or on a radiant housing 18, the heat stopper 66 prevents at least partially the heat emitted by the electrical heating conductor 62 from escaping out of an interior volume 29 of the radiant housing 18. In addition, the heat stopper 66 may also support the electrical heating conductor 62 or a part thereof, in which case the heat stopper 66 is preferably electrically insulating.

[0055] The electrical heating insert 60 may further comprise a heat barrier 98 configured for covering a gap 56 between the heat stopper 66 and an inner surface 58 of the radiant housing 18. The heat barrier 98 is represented by way of example in Fig. 19.

[0056] The electrical heating insert 60 may further comprise electrical terminals 70 for electrically coupling the electrical heating insert 60 to an electrical energy source. More precisely, the electrical terminals 70 are electrically coupled to the electrical heating conductor 62 within the electrical heating insert 60.

[0057] Figures 9 to 11 respectively represent by way of example: a radiant housing 18, an electrical heating insert 60, and an electrical heating insert 60 arranged in a radiant housing 18.

[0058] Fig. 9 schematically illustrates a radiant housing 18 extending along a first main axis 23 and having a first end 181 which is an open end 183 and a second end 182 which is a closed end 184. In addition, the radiant housing 18 has a flange 40 at its first end 181.

[0059] Fig. 10 schematically illustrates an electrical heating insert 60 extending along a second main axis 61. The electrical heating insert 60 comprises an electrical heating conductor 62 in the shape of a plurality of rods. The electrical heating insert 60 also comprises a plurality of support elements 64 for supporting the electrical heating conductor 62. The plurality of support elements 64 are made of ceramic material. The plurality of support elements 64 are mechanically coupled to a central support bar 68 made of refractory steel. The central support bar 68 is protected from the heat emitted by the electrical heating conductor 62 by a sheath 69 made of ceramic material. The electrical heating insert 60 further comprises electrical terminals 70 for electrically coupling the electrical heating insert 60 to an electrical energy source. The electrical terminals 70 are electrically coupled to the electrical heating conductor 62 within the electrical heating insert 60. The electrical heating insert 60 further comprises a heat stopper 66 in the shape of a cylinder and made of ceramic material.

[0060] Fig. 11 schematically illustrates the electrical heating insert 60 of Fig. 10 arranged in the radiant housing 18 of Fig. 9. The electrical heating insert 60 rests on a wall 24 of the radiant housing 18. The second main axis 61 of the electrical heating insert 60 is parallel to the first main axis 23 of the radiant housing 18. The heat stopper 66 prevents at least partially the heat emitted by the electrical heating conductor 62 from escaping out of an interior volume 29 of the radiant housing 18. There is a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18 for inserting a tool 80 for manipulating the electrical heating insert 60.

[0061] In an embodiment, the electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis 61, i.e. in several orientations relative to the second main axis 61. This allows the electrical heating insert 60 to be rotated around the second main axis 61 with a reduced risk of damage for the electrical heating insert 60 or a part thereof, such as an electrical heating conductor 62 comprised in the insert 60. An advantage of being able to operate an electrical heating insert 60 in a plurality of angular positions relative to the second main axis 61 is to facilitate a maintenance operation for extending the service life of the radiant housing 18 in which the insert 60 is arranged. Indeed, the radiant housing 18 may deform, and in particular sag or bend, during operation due to creep and / or fatigue. In order to compensate for such deformation, the radiant housing 18 may be periodically rotated around the first main axis 23 during a maintenance operation, therebyextending the service life of the radiant housing 18. Rotating the radiant housing 18 with the electrical heating insert 60 inside facilitates the maintenance operation by avoiding additional steps of insertion or removal of the insert 60 into or from the housing 18. However, this is possible only if the electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis 61. Indeed, during the rotation of the radiant housing 18 around the first main axis 23, the electrical heating insert 60 comprised in the housing 18 also rotates around the second main axis 61 , thereby taking a new angular position relative to the second main axis 61.

[0062] To enable the electrical heating insert 60 to operate in a plurality of angular positions relative to the second main axis 61 , the electrical heating conductors 62 comprised in the insert 60 are preferably arranged uniformly along a circumferential direction, i.e. in a radially symmetric way with respect to the second main axis 61. This allows the heat emitted by said conductors 62 to be emitted uniformly along the circumferential direction. Uniform arrangement of the electrical heating conductors 62 along the circumferential direction means that said conductors 62 are symmetrically positioned in a plane perpendicular to the second main axis 61. This is represented by way of example in Figures 20 to 25.

[0063] In an embodiment, an envelope 72 of the electrical heating insert 60 is substantially cylindrical in shape and has a uniform cross-section along the second main axis 61 of the electrical heating insert 60. An envelope 72 of the electrical heating insert 60 is defined herein as a closed surface surrounding the electrical heating insert 60. Herein, when the cross-section of the envelope 72 of the electrical heating insert 60 is said to be uniform along the second main axis 61 , it is meant that the cross-section is uniform enough along the second main axis 61 to limit the deformation of the insert 60 or a part thereof after a rotation of the insert 60 around the second main axis 61 , so as to reduce a risk of damage for the insert 60 or a part thereof after the rotation. An advantage of this embodiment is that it allows the radiant housing 18 to be rotated around the first main axis 23 with a reduced risk of damage for an electrical heating insert 60 arranged in or on the radiant housing 18. Indeed, when a radiant housing 18 is rotated around the first main axis 23, an electrical heating insert 60 arranged in or on the radiant housing 18 and having a cylindrical envelope 72 with a uniform cross-section along the second main axis 61 may roll uniformly within the radiant housing 18, i.e. all sections of the insert 60 may rotate around the second main axis 61 in a similar manner, thereby allowing the radiant housing 18 to be rotated around the first main axis 23 with a reduced risk of damage for the electrical heating insert 60 or a part thereof. On the contrary, if the insert 60 has cross-sections transverse to the second main axis 61 of various diameters,these sections will rotate at different speeds when the radiant housing 18 is rotated. This may lead to undesired friction of part of the insert 60 against a wall 24 of the radiant housing, which may damage the insert 60 or some of its components for several reasons. A first reason is because the insert 60 may comprise some brittle parts made of ceramic material such as the at least one support element 64, which may be damaged if they rub against a wall 24 of the radiant housing 18. Another reason is because this may lead to undesired deformation (e.g. by flexion or torsion) of an electrical heating conductor 62 comprised in the insert 60.

[0064] In an embodiment, the electrical heating insert 60 further comprises a heat barrier 98 configured for covering a gap 56 between the heat stopper 66 and an inner surface 58 of the radiant housing 18. The heat barrier 98 is not part of the heat stopper 66, but rather comes in addition to the heat stopper 66 for preventing the heat emitted by the electrical heating conductor 62 comprised in the electrical heating insert 60 from escaping out of an interior volume 29 of the radiant housing 18. The heat barrier 98 may consist of a refractory material, such as a ceramic material, or compressed refractory fibers, or a fibrous material such as glass wool or rock wool. Generally, the heat barrier 98 may differ in composition from the support element 64 or the heat stopper 66. An advantage of the heat barrier 98 is to block at least a portion of the heat that is emitted by the electrical heating conductor 62 and that may otherwise pass through the gap 56 between the heat stopper 66 and the inner surface 58 of the radiant housing 18. The heat barrier 98 preferably covers the gap 56 by being arranged either in the gap 56 or in front of the gap 56. The heat barrier 98 is represented by way of example in Fig. 19.

[0065] An advantage of this embodiment is to allow the heat stopper 66 to have a smaller diameter 95 than the inner diameter 96 of the radiant housing 18 while still effectively preventing the heat emitted by the electrical heating conductor 62 of the insert 60 from escaping the interior volume 29 of the radiant housing 18. It is advantageous for the heat stopper 66 to be of such smaller diameter 95 for allowing the insert 60 to be rotated around its main axis 61 with a reduced risk of damage for the insert 60 or a part thereof, as described hereinabove.Radiant housing

[0066] A radiant housing 18 used to heat the inner volume 20 as described herein is preferably a closed radiant housing 18. A closed radiant housing 18 comprises a wall 24 between a power source comprised in the housing 18 and the inner volume 20. In a closed radiant housing 18, radiant energy emitted by the power source heats the wall 24 of thehousing 18, then the radiant housing 18 heats the inner volume 20. In other words, in the case of a closed radiant housing 18, the power source comprised in the housing 18 heats the inner volume 20 in an indirect manner. Said power source is preferably an electrical power source, such as an electrical heating insert 60. Other power sources are possible. An advantage of using an electrical power source is that electricity is more environmentally friendly than fossil energy sources such as gas or fuel. An advantage of a closed radiant housing 18 is to separate the atmosphere of the inner volume 20 from the atmosphere of an interior volume 29 of the radiant housing 18. This protects the power source comprised in the housing 18 from the atmosphere of the inner volume 20. Indeed, the atmosphere of the inner volume 20 may be an oxidizing atmosphere or a reducing atmosphere, which may damage the power source or a part thereof. In addition, the atmosphere of the interior volume 29 may contain impurities or chemical compounds that may soil, damage or generally have a negative impact on some properties of the strip 12 conveyed in the inner volume 20. Therefore, it is also advantageous to protect the inner volume 20 or an element conveyed therein, such as the strip 12, from the atmosphere of the interior volume 29. A closed radiant housing 18 may be for example a radiant tube, preferably a radiant tube in the shape of a cylinder.

[0067] In an embodiment, the first end 181 of the radiant housing 18 is configured for allowing the insertion of a measuring device 51 through said first end 181 for measuring a physical property of the inner volume 20.

[0068] Preferably, the measuring device 51 is a thermocouple for measuring a temperature of the inner volume 20.

[0069] In this embodiment, the measuring device 51 may be inserted in a guide tube mechanically coupled to an outer surface of the radiant housing 18, i.e. a surface in contact with the inner volume 20. The measuring device 51 may be inserted in the guide tube through an opening in the first end 181 of the radiant housing 18, for instance through an opening 52 in the flange 40 of the first end 181 of the radiant housing 18. An advantage of inserting the measuring device 51 in a guide tube instead of inserting it directly in the inner volume 20 is that it may prevent an undesirable leak of atmosphere of the inner volume toward the exterior. Another advantage is to protect the measuring device 51 from the atmosphere of the inner volume 20. Indeed, the atmosphere of the inner volume 20 may be an oxidizing atmosphere or a reducing atmosphere, which may damage the measuring device 51 or a part thereof. Alternatively, the measuring device 51 may be inserted directly in the inner volume through an opening in the first end 181 of the radiant housing 18, for instance through an opening 52 in the flange 40 of the first end 181 of the radiant housing 18. In this case, gas-tightness may beensured so as to avoid a leak of atmosphere of the inner volume 20, e.g. with a seal such as a clamping gasket.

[0070] In an embodiment, the first end 181 of the radiant housing 18 is configured for allowing the insertion of a measuring device 51 through said first end 181 for measuring a physical property of an interior volume 29 of the radiant housing 18.

[0071] Preferably, the measuring device 51 is a thermocouple for measuring a temperature of the interior volume 29.

[0072] Fig. 8 schematically represents a front view of a heating assembly 16 comprising a plurality of radiant housings 18 arranged along an axis 28 transverse to the respective main axes 23 of the radiant housings 18. In particular, two radiant housings 18 are represented in Fig. 8, but the plurality of radiant housings 18 may generally comprise two or more radiant housings 18, as indicated by the dashed lines at the top and bottom of Fig. 8. In addition, Fig. 8 illustrates an opening 52 in the flange 40 of the first end 181 of a radiant housing 18. The opening 52 allows the insertion of a measuring device 51 through said first end 181 for measuring a physical property of the inner volume 20, such as the insertion of a thermocouple for measuring a temperature of the inner volume 20. Fig. 8 also illustrates an opening 54 in the first end 181 of a radiant housing 18. The opening 54 allows the insertion of a measuring device 51 through said first end 181 for measuring a physical property of an interior volume 29 of the radiant housing 18, such as the insertion of a thermocouple for measuring a temperature of the interior volume 29.

[0073] In an embodiment, the radiant housing 18 is substantially cylindrical in shape. In this embodiment, the radiant housing 18 is preferably a radiant tube.

[0074] In an embodiment, the first end 181 of the radiant housing 18 is an open end 183. In this embodiment, the first end 181 of the radiant housing is preferably open towards the exterior of the heating assembly 16 and the second end 182 of the radiant housing 18 is preferably a closed end 184, so that the radiant housing 18 is a closed radiant housing 18. An advantage of a closed radiant housing 18 is to separate the atmosphere of the inner volume 20 from the atmosphere of the interior volume 29 of the radiant housing 18.

[0075] Preferably, said open end 183 is configured for allowing the insertion of an electrical heating insert 60 into the radiant housing 18, i.e. the open end 183 is large enough to allow the electrical heating insert 60 to be inserted into the radiant housing 18 and / or removed from the radiant housing 18. Preferably, the open end 183 is also large enough to allow the insertion of a tool 80 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18 for manipulating the electrical heating insert 60. The gap56 is at least 1mm wide, preferably at least 5mm wide, more preferably at least 10mm wide. The open end 183 and the gap 56 are illustrated by way of example in Fig. 11.

[0076] In an embodiment, the radiant housing 18 is made of steel. Steel, and in particular refractory steel, is a material that can withstand or operate at high temperatures. Steel also offers good mechanical strength properties, while being relatively easy to shape for the construction of such a radiant housing 18. In particular, the radiant housing 18 may be made of sheet steel, or cast steel, or using powder metallurgy techniques.

[0077] In an embodiment, a surface of the radiant housing 18 is not smooth. The nonsmooth surface improves the mechanical strength of the radiant housing 18. As an example, a surface of a radiant housing 18 made of sheet steel may comprise bubble-like patterns. As another example, a surface of a radiant housing 18 made of cast steel may be corrugated.Rotation of a radiant housing around its main axis

[0078] A radiant housing 18 comprised in a heating assembly 16 may be rotated around the first main axis 23 by an angle of rotation in a maintenance operation. An advantage of such a rotation of the radiant housing 18 around the first main axis 23 is to allow creep and / or fatigue to be exerted in another direction, thereby at least partially compensating for previous deformation of the radiant housing 18 caused by creep and / or fatigue and therefore extending the service life of the radiant housing 18. The angle of rotation is comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°. Even more preferably, the angle of rotation of the radiant housing 18 around the first main axis 23 is substantially equal to 180°, which compensates for previous deformation of the radiant housing 18 caused by creep and / or fatigue and therefore extends the service life of the radiant housing 18. The radiant housing 18 is rotated while resting on the first and second supports 26, 27, as enabled by the supporting means 30. Fig. 3 and Fig. 4 schematically illustrate by way of example such a maintenance operation performed on a heating assembly 16 comprising a deformed radiant housing 18. In Fig. 4, a rotation of the radiant housing 18 around the first main axis 23 is schematically represented by arrows 32.

[0079] The maintenance operation may comprise the following steps:(a) removing the electrical heating insert 60 from the radiant housing 18 before the rotation of the radiant housing 18 performed in step (d);(b) releasing the blocking means preventing rotation of the radiant housing 18 around the first main axis 23;(c) translating the radiant housing 18 along the first main axis 23 for separating the first end 181 of the radiant housing 18 from the blocking means preventing rotation of the radiant housing 18 around the first main axis 23, while the radiant housing 18 is supported by the first support 26 and the second support 27;(d) rotating the radiant housing 18 by an angle of rotation around the first main axis 23 while the radiant housing 18 is supported by the first support 26 and the second support 27;(e) translating the radiant housing 18 along the first main axis 23 for joining the first end 181 of the radiant housing 18 with the blocking means preventing rotation of the radiant housing 18 around the first main axis 23, while the radiant housing 18 is supported by the first support 26 and the second support 27;(f) reinstalling the blocking means for preventing rotation of the radiant housing 18 around the first main axis 23;(g) inserting the electrical heating insert 60 into the radiant housing 18 after the rotation of the radiant housing 18 performed in step (d).

[0080] Said steps are executed preferably, but not necessarily, in the indicated order, i.e. the alphabetical order. Some of the steps described hereinabove are optional. In addition, some of said steps are related to each other. Related steps are preferably performed together during the maintenance operation. In particular, steps (a) and (g) are related to each other. Steps (b) and (f) are also related to each other. Finally, steps (c) and (e) are also related to each other.

[0081] Step (c) may offer an opportunity to replace a gas-tight seal such as a gasket 44, e.g. in case it is damaged.

[0082] In step (d), it is possible to apply several (partial) rotations of the radiant housing 18, so that the electrical heating insert 60 reaches a target orientation after the rotation.Support for a radiant housing and comprising a bearing

[0083] Generally, the radiant housing 18 may need to be rotated around the first main axis 23, for instance in order to compensate for previous deformation of the radiant housing 18 so as to extend its service life. To this end, there may be provided a support 27 for supporting a radiant housing 18 within a furnace chamber 11 of an industrial furnace 10. The furnace chamber 11 of the industrial furnace 10 comprises the inner volume 20 of the heating assembly 16. The radiant housing 18 extends along a first main axis 23 and comprises a first end 181 , a second end 182. In addition, the radiant housing 18 comprises an electrical heating insert 60. In other words, the radiant housing 18 is electrically powered. The support 27described in this section is an example of the second support 27 for supporting the second end 182 of the radiant housing 18 as described hereinbefore. Therefore, all the possible embodiments of the second support 27 as described hereinbefore and the advantages of these embodiments apply mutatis mutandis to the support 27 described in this section.

[0084] The support 27 may support one or more radiant housings 18 in the furnace chamber H . In other words, the support 27 may support at least one radiant housing 18. In an embodiment, the support 27 supports a single radiant housing 18. In another embodiment, the support 27 supports a plurality of radiant housings 18.

[0085] The support 27 comprises a coupling interface 33 for mechanically coupling with a socket 46 in the furnace chamber 11. The support 27 is configured to be coupled to the socket 46 via the coupling interface 33. The socket 46 is not part of the support 27. The socket 46 is preferably arranged on a wall 21 , 22 of the industrial furnace 10. The socket 46 may be an existing socket 46, for instance in the case of a revamping of the industrial furnace 10. The support 27 may comprise more than one coupling interface 33 for coupling with more than one socket 46. Generally, the support 27 may be configured for coupling with one or more sockets 46. In an embodiment, the support 27 is configured for coupling with a single socket 46. In another embodiment, the support 27 is configured for coupling with a plurality of sockets 46.

[0086] The support 27 further comprises a bearing 31 for supporting the second end 182 of the radiant housing 18. The bearing 31 is configured for allowing a rotation of the radiant housing 18 around the first main axis 23. In the case of a deformed radiant housing 18, for instance due to creep and / or fatigue, such a rotation allows creep and / or fatigue to be exerted in another direction, thereby at least partially compensating for previous deformation of the radiant housing 18 and therefore extending the service life of the radiant housing 18. The angle of rotation of the radiant housing 18 around the first main axis 23 may be comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°. Even more preferably, the rotation of the radiant housing 18 around the first main axis 23 is substantially equal to 180°, which compensates for previous deformation of the radiant housing 18 caused by creep and / or fatigue and therefore extends the service life of the radiant housing 18.

[0087] The radiant housing 18 rests on the bearing 31. In other words, the radiant housing 18 is simply placed on the bearing 31. The radiant housing 18 is rotatably coupled to the support 27 through the bearing 31 , i.e. the radiant housing 18 is able to rotate freely around the first main axis 23 while being supported by the bearing 31. In particular, the rotation of the radiant housing 18 around the first main axis 23 is not enabled by the socket 46 but rather bythe bearing 31 comprised in the support 27. Indeed, the support 27 is preferably rigidly coupled to the socket 46. In addition, the bearing 31 is distinct from the socket 46. The bearing 31 and the socket 46 are two different parts. The bearing 31 is part of the support 27. The socket 46 is not part of the support 27.

[0088] In an embodiment, the radiant housing 18 is substantially cylindrical in shape. In this embodiment, the radiant housing 18 is preferably a radiant tube.

[0089] In an embodiment, the bearing 31 is configured for supporting a radiant housing 18 whose cross-section with respect to the first main axis 23 is larger than the socket 46. An advantage of this embodiment is to allow a housing 18 that is larger than the socket 46, i.e. that would not adapt to the socket 46 or that cannot be directly fixed on the socket 46, to be supported within the furnace chamber 11. In this embodiment, such housing 18 larger than the socket 46 may be supported in the bearing 31 with no need to adapt the shape of the housing 18 to the socket 46, nor to add to the housing 18 a part fitting the socket 46, such as a pin. This is advantageous since this fitting part could constitute a stress concentration point and therefore a weak point in the mechanical structure of the housing 18 that could shorten the service life of the housing 18.

[0090] In the particular case of a cylindrical housing 18, such as a radiant tube, and a cylindrical socket 46, this embodiment implies that an outer diameter 185 of the housing 18 is larger than an inner diameter 461 of the socket 46, such that the housing 18 cannot be inserted directly into the socket 46, as represented by way of example in Fig. 2. An outer diameter 185 of the housing 18 is a diameter of a circle circumscribed to the housing 18. An inner diameter 461 of the socket 46 is a diameter of a circle inscribed in the socket 46. Herein, a circle circumscribed to an object or a circle inscribed in an object is assumed to be tangent in at least one point to the object.

[0091] In an embodiment, the coupling interface 33 is configured for being inserted into the socket 46. Inserting the coupling interface 33 into the socket may improve the mechanical coupling between the support 27 and the socket 46. In particular, the insertion of the coupling interface 33 into the socket 46 may allow the support 27 to withstand a greater torque. Besides, the insertion of the coupling interface 33 into the socket 46 may also enable a weld-free mechanical coupling between the support 27 and the socket 46. Indeed, welding a support 27 on a socket 46 in a furnace chamber 11 of an industrial furnace 10 may be difficult, in particular in the case of an existing socket 46 in the furnace chamber 11, for example in a revamping of the furnace 10. Indeed, the existing socket 46 may be deformed, or its chemical composition may be altered, particularly at the surface level, in a way that may be difficult to predict ormeasure. A weld-free mechanical coupling between the support 27 and the socket 46 may be performed for example with clamps or hooks for securing the coupling interface 33 into the socket 46.

[0092] In an embodiment, the coupling interface 33 comprises a shaft 47 configured for being inserted into the socket 46. The shaft 47 may facilitate the insertion of the coupling interface 33 into the socket 46.

[0093] In an embodiment, the bearing 31 is further configured for allowing a translation of the radiant housing 18 along the first main axis 23. Such a translation may occur during operation, for instance due to thermal expansion of the radiant housing 18, or during maintenance. A translation of the radiant housing 18 on the bearing 31 may facilitate a maintenance operation by allowing the radiant housing 18 to be slightly separated from one of the furnace wall portions 21 , 22 while the radiant housing 18 continues to be supported by the bearing 31 , such as to allow an easier rotation of the radiant housing 18 around the first main axis 23 during maintenance. Said translation may also facilitate the construction (or erection) or the revamping of the furnace 10 by allowing the radiant housing 18 to be installed on the support 27 in a temporary position close to a final position, with the radiant housing 18 being already supported by the bearing 31 in the temporary position. Said translation therefore allows the radiant housing 18 to be inserted into or removed from the furnace 10 in a simpler manner.

[0094] In an embodiment, the radiant housing 18 is movable along the first main axis 23 in sliding friction relative to the bearing 31. Herein, the expression “movable in sliding friction” designates a relative displacement between two objects in contact with each other wherein one object slides on the other. “Sliding friction”, also known as “kinetic friction”, is a resistive force that acts between two surfaces in relative motion. Herein, a displacement in sliding friction is meant to be opposed to a displacement in rolling friction, which designates a relative displacement between two objects in contact with each other wherein one object rolls on the other. In this embodiment, the radiant housing 18 may move relative to the bearing 31 in sliding friction, i.e. by sliding on the bearing 31. An advantage of this embodiment is to allow thermal expansion of the radiant housing 18 to be accommodated during operation. Another advantage of this embodiment is to facilitate the manipulation of a radiant housing 18 during maintenance.

[0095] In an embodiment, the bearing 31 further comprises a pad 48 for preventing sticking of the radiant housing 18 to the bearing 31, in particular during operation. The pad 48 is placed between the radiant housing 18 and the bearing 31.

[0096] In an embodiment, the bearing 31 supports the radiant housing 18 over a distance of at least 10mm. An advantage of this embodiment is to reduce the pressure between the housing 18 and the bearing 31 compared to a smaller contact interface between the housing 18 and the bearing 31. Another advantage of this embodiment is to reduce the stress concentration within the housing 18 and / or the bearing 31 at their contact area compared to a smaller contact interface between the housing 18 and the bearing 31. Preferably, the distance is at least 50mm, more preferably at least 100mm, even more preferably at least 150mm, which allows a further reduction of the pressure and / or the stress concentration.

[0097] In an embodiment, the bearing 31 has a cross-section transverse to the first main axis 23 in the shape of a circular arc. An advantage of this embodiment is to facilitate the rotation of the housing 18 on the bearing 31.

[0098] In an embodiment, a diameter 311 of said circular arc is larger than an outer diameter 185 of the radiant housing 18 by at least 1mm. An advantage of this embodiment is to allow the bearing 31 to accommodate a larger diversity of radiant housings 18, i.e. radiant housings 18 with more diverse shapes and / or dimensions. Preferably, the diameter 311 of the circular arc is larger than the outer diameter 185 of the radiant housing 18 by at least 5mm, more preferably at least 10mm, even more preferably at least 50mm, which allows the bearing 31 to accommodate an even larger diversity of radiant housings 18.

[0099] In an embodiment, the support 27 further comprises blocking means for preventing rotation of the radiant housing 18 around the first main axis 23 during operation, i.e. during use of the radiant housing 18 for heating the furnace chamber 11. Examples of said blocking means for the support 27 are given below. I n a first example, the end 182 of the radiant housing 18 supported in the bearing 31 has a square cross-section with respect to the first main axis 23. In a second example, the end 182 of the radiant housing 18 supported in the bearing 31 comprises a clamp for preventing rotation of the housing 18.

[0100] In an embodiment, the bearing 31 is further configured for allowing a local rotation of the second end 182 of the radiant housing 18 around a second transverse axis 38 transverse to the first main axis 23. The local rotation may be due to a deformation of the housing 18. For instance, the local rotation may occur during operation, i.e. during use of the radiant housing 18 for heating the furnace chamber 11. Indeed, the second end 182 of the radiant housing 18 may locally rotate around the second transverse axis 38 due to a deformation of the radiant housing 18 caused by creep and / or fatigue, said deformation being for example a bending of the radiant housing 18, as represented by way of example in Fig. 6. By way of example, the second end 182 of the radiant housing 18 may locally rotate around the second transverseaxis 38 by 1.5° when the radiant housing 18 is deformed. An advantage of this embodiment is to allow the radiant housing 18 to deform while continuing to be supported by the bearing 31. Another advantage of this embodiment is to allow the radiant housing 18 to deform without being overly constrained in the bearing 31.

[0101] In an embodiment, the support 27 further comprises a plurality of bearings 31 for supporting respective ends of a plurality of radiant housings 18, each radiant housing 18 extending along a respective main axis 23, each bearing 31 being configured for allowing a rotation of a radiant housing 18 around its respective main axis 23. In this embodiment, each bearing 31 supports an end of a radiant housing 18. In addition, each radiant housing 18 in the plurality is rotatable individually around its respective main axis 23, i.e. independently of the configuration of the other radiant housings 18 in the plurality or, more precisely, independently of the angular position of the other radiant housings 18 in the plurality relative to their respective main axes 23. An advantage of this embodiment is to allow an individual maintenance operation for each of the radiant housings 18 supported by the support 27. Indeed, the bearings 31 comprised in the support 27 enable an individual rotation of each radiant housing 18 in the plurality around its respective main axis 23.

[0102] Preferably, the plurality of radiant housings 18 are arranged in the furnace chamber 11 along an axis 28 transverse to their respective main axes 23. In this embodiment, the plurality of radiant housings 18 are preferably arranged vertically, or in other words on top of each other, in the furnace chamber 11 , as represented by way of example in Fig. 8. In other words, the plurality of bearings 31 are preferably arranged along an axis 312. The axis 312 is represented by way of example in Fig. 5.

[0103] In an embodiment, a heating assembly 16 comprises a support 27 as described in this section as second support 27. In this embodiment, the bearing 31 of the support 27 acts as a supporting means 30.

[0104] Preferably, a heating assembly 16 comprising a support 27 as described in this section further comprises: a refractory insulation 25 covering the second furnace wall portion 22; a socket 46 on the second furnace wall portion 22 in the refractory insulation 25, the second support 27 being mechanically coupled with the socket 46.

[0105] Fig. 2 schematically represents by way of example a heating assembly 16. The heating assembly 16 comprises a first furnace wall portion 21 and a second furnace wall portion 22 facing each other. The first and the second furnace wall portions 21 , 22 delimit an inner volume 20 of the heating assembly 16. A first main axis 23 extends between said wallportions 21 , 22. The first and the second furnace wall portions 21, 22 are covered with refractory insulation 25. The heating assembly 16 comprises a radiant housing 18 for heating the inner volume 20. The radiant housing 18 extends along the first main axis 23 and comprises a first end 181 and a second end 182. The heating assembly 16 further comprises a first support 26 for supporting the first end 181 of the radiant housing 18. The first support 26 is arranged on the first wall portion 21. The heating assembly 16 further comprises a second support 27 for supporting the second end 182 of the radiant housing 18. The second support 27 is arranged on the second wall portion 22. The radiant housing 18 is configured for operating in a plurality of angular positions relative to the first main axis 23. The first support 26 and the second support 27 comprise supporting means 30 configured for allowing a rotation of the radiant housing 18 around the first main axis 23 during maintenance, with said radiant housing 18 resting on said first and second supports 26, 27. An outer diameter of the radiant housing 18 is designated by arrows 185.

[0106] In Fig. 2, the first support 26 is arranged outside the inner volume 20. The first support 26 comprises supporting means 30 for supporting the first end 181 of the radiant housing 18. The supporting means 30 of the first support 26 are further configured for allowing a translation of the radiant housing 18 along the first main axis 23. The first support 26 further comprises a stop 50 for limiting the translation of the radiant housing 18 along the first main axis 23. The first support 26 further comprises compensating means 34 for allowing a flexible coupling of the first end 181 of the radiant housing 18 to the first wall portion 21 , so that the radiant housing 18 may deform or expand while remaining coupled to the first wall portion 21. The compensating means 34 of the first support 26 comprise a corrugated sleeve 35 mechanically coupled to the first end 181 of the radiant housing 18 and to the first wall portion 21. More precisely, the first end 181 of the radiant housing 18 and the sleeve 35 each comprise a respective flange 40, 42. Both flanges 40, 42 may be bolted together for preventing rotation of the radiant housing 18 around the first main axis 23 during operation. The first end 181 of the radiant housing 18 is gas-tightly sealed against the first wall portion 21 during operation. More precisely, the heating assembly 16 further comprises a gasket 44 for ensuring the gastight sealing between the first end 181 of the radiant housing 18 and the first wall portion 21 during operation. Said gasket 44 is arranged between the flange 40 of the first end 181 of the radiant housing 18 and the flange 42 of the sleeve 35.

[0107] In Fig. 2, the second support 27 is arranged inside the inner volume 20. The second support 27 is mechanically coupled to the second wall portion 22 through a socket 46. The second support 27 comprises supporting means 30 for supporting the second end 182 ofthe radiant housing 18. The supporting means 30 of the second support 27 are further configured for allowing a translation of the radiant housing 18 along the first main axis 23. The second support 27 further comprises a pad 48 for preventing sticking of the second end 182 of the radiant housing 18 to the second support 27. The pad 48 is placed between the second end 182 of the radiant housing 18 and the second support 27. An inner diameter of the socket 46 is designated by arrows 461.

[0108] Fig. 5 schematically represents by way of example a support 27 for supporting a plurality of radiant housings 18. The support 27 comprises a plurality of bearings 31. Each bearing 31 may support an end of a radiant housing 18. Each bearing 31 is configured for allowing a rotation of a radiant housing 18 around a first main axis 23. In particular, two bearings 31 are represented in Fig. 5, but the plurality of bearings 31 may generally comprise two or more bearings 31 , as indicated by the dashed lines at the top and bottom of the support 27 of Fig. 5. In Fig. 5, the bearings 31 are arranged along an axis 312. Each bearing 31 of Fig. 5 has a cross-section in the shape of a circular arc. A diameter of said circular arc is designated by the arrow 311. The support 27 represented in Fig. 5 further comprises a coupling interface 33 for mechanically coupling with a socket 46. The socket 46 is arranged on a furnace wall portion 22. The coupling interface 33 is configured for being inserted into the socket 46. More precisely, the coupling interface 33 comprises a shaft 47 configured for being inserted into the socket 46. The socket 46 represented in Fig. 5 is a cylindrical socket. An inner diameter of the socket 46 is designated by arrows 461. The support 27 represented in Fig. 5 may generally comprise one or more coupling interfaces 33 for coupling with one or more respective sockets 46, as indicated by the additional coupling interface and socket represented in dotted lines in Fig. 5 and as also indicated by the dashed lines at the top and bottom of the furnace wall portion 22 of Fig. 5.Tool for manipulating an electrical heating insert

[0109] Generally, the electrical heating insert 60 may be configured for being inserted into or removed from the radiant housing 18. In particular, the electrical heating insert 60 may be manipulated with a tool 80 for performing such insertion or removal with a reduced risk of damage for the electrical heating insert 60 or a part thereof. To this end, there may be provided a set 17 for heating a furnace chamber 11 of an industrial furnace 10 and for maintenance. The furnace chamber 11 of the industrial furnace 10 comprises the inner volume 20 of the heating assembly 16. The set 17 comprises a radiant housing 18, an electrical heating insert60 arranged in the radiant housing 18, and a tool 80 for manipulating the electrical heating insert 60.

[0110] The radiant housing 18 extends along a first main axis 23 and comprises a first end 181 and a second end 182. The radiant housing 18 is preferably mounted substantially horizontally in the industrial furnace 10.

[0111] The electrical heating 60 insert extends along a second main axis 61 and comprises an electrical heating conductor 62 and at least one support element 64 for supporting the electrical heating conductor 62. The at least one support element 64 is made of a heat-resistant and electrically insulating material, such as a ceramic material, which may be brittle. The second main axis 61 of the electrical heating insert 60 is substantially parallel to or even merged with the first main axis 23 of the radiant housing 18. The electrical heating insert 60 may also be referred to herein as a resistive insert. Preferably, the electrical heating conductor 62 is electrically insulated from the radiant housing 18, more precisely from a wall 24 of the radiant housing 18.

[0112] The tool 80 extends along a third main axis 81. More precisely, the tool 80 comprises at least one part extending along the third main axis 81. The third main axis 81 of the tool 80 is substantially parallel to or even merged with the first main axis 23 of the radiant housing 18. The tool 80 is preferably made of a material able to withstand a high temperature, such as for example refractory steel.

[0113] The radiant housing 18, the electrical heating insert 60, and the tool 80 of the set 17 are configured such that: during operation, the at least one support element 64 is in contact with a wall 24 of the radiant housing 18, thereby supporting the electrical heating insert 60 on the radiant housing 18; during maintenance, the tool 80 is arranged between the electrical heating insert 60 and the wall 24 of the radiant housing 18, thereby enabling a translation of the electrical heating insert 60 along the first main axis 23 with no direct contact between the at least one support element 64 or a part thereof and the wall 24 of the radiant housing 18.

[0114] Preferably, the tool 80 is removably arranged in the radiant housing 18 during maintenance, such that the tool 80 may be removed from the radiant housing 18 before operation.

[0115] Preferably, during maintenance, the tool 80 is arranged between the electrical heating insert 60 and the wall 24 of the radiant housing 18 in such a way as to enable a translation of the electrical heating insert 60 along the first main axis 23 with no direct contact between any part of the at least one support element 64 and the wall 24 of the radiant housing 18.

[0116] Herein, two working modes of the set 17 are considered: an operating mode, and a maintenance mode. The operating mode is also generally designated herein by the following expressions: “during operation”, “during operation of the radiant housing”, “during use of the radiant housing for heating the furnace chamber”, “during heating mode”. The maintenance mode is also generally designated herein by the following expressions: “during maintenance”, “during a maintenance operation”.

[0117] The maintenance operation of the heating assembly 16 as described hereinbefore comprises a rotation of the radiant housing 18 around the first main axis 23 in order to compensate for previous deformation of the radiant housing 18 and therefore extend the service life of the radiant housing 18. In particular, the maintenance operation of the heating assembly 16 may be performed with an electrical heating insert 60 arranged in or on the radiant housing 18. Said maintenance operation may also be performed with no electrical heating insert 60 arranged in or on the radiant housing 18.

[0118] The maintenance operation of the set 17 as described herein comprises a manipulation of the electrical heating insert 60 arranged in or on the radiant housing 18 of the set 17. Said manipulation is performed with the tool 80 of the set 17. During the maintenance operation of the set 17, the electrical heating insert 60 is manipulated with the tool 80 with no direct contact between the at least one support element 64 or a part thereof and the wall 24 of the radiant housing 18. The maintenance operation of the set 17 allows the electrical heating insert 60 to be manipulated with a reduced risk of damage for the electrical heating insert 60 or a part thereof. In particular, the maintenance operation of the set 17 allows the electrical heating insert 60 to be inserted into or removed from the radiant housing 18 with a reduced risk of damage for the electrical heating insert 60 or a part thereof, such as the at least one support element 64 comprised in the electrical heating insert 60. Indeed, an electrical heating insert 60 arranged in or on a radiant housing 18 may comprise brittle parts that may be easily damaged when manipulating the electrical heating insert, in particular when said brittle parts rub against a wall 24 of the radiant housing 18, for instance when the electrical heating insert 60 is inserted into or removed from the radiant housing 18. The at least one support element 64 comprised in the electrical heating insert 60 is an example of such a brittle part. In addition, the maintenance operation of the set 17 may also comprise a rotation of the radiant housing 18 around the first main axis 23.

[0119] In the case of a deformed radiant housing 18, a rotation of said housing 18 around the first main axis 23 may not lead to a rotation of an electrical heating insert 60 comprised insaid housing 18. In this case, it is advantageous to remove the insert 60 from the housing 18 prior to the rotation the housing 18, which is made possible with the set 17.

[0120] In the case of a deformed radiant housing 18, in particular in the case of a bent radiant housing 18 due to creep and / or fatigue, the tool 80 is preferably flexible in order to facilitate the insertion of the tool 80 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18 and improve the conformation of the tool 80 with the deformed radiant housing 18. In the case of a deformed radiant housing 18, the electrical heating insert 60 comprised in the radiant housing 18 may also be deformed. In this case, an advantage of a flexible tool 80 is to improve the conformation of the tool 80 with the deformed electrical heating insert 60.

[0121] Preferably, the tool 80 is configured for allowing the manipulation of an electrical heating insert 60 equipped with a measuring device 51 , such as a thermocouple.

[0122] In an embodiment, the radiant housing 18 is configured for operating in a plurality of angular positions relative to the first main axis 23. The radiant housing 18 may be rotated around the first main axis 23 with or without the electrical heating insert 60 inside it. In addition, the radiant housing 18 may be rotated around the first main axis 23 independently of the angular position of the electrical heating insert 60 relative to the second main axis 61. Therefore, the relative angular position of the radiant housing 18 and the electrical heating insert 60 around their respective main axes 23, 61 may vary.

[0123] In an embodiment, the radiant housing 18 is substantially cylindrical in shape. In this embodiment, the radiant housing 18 is preferably a radiant tube.

[0124] In an embodiment, the electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis 61.

[0125] In an embodiment, an envelope 72 of the electrical heating insert 60 is substantially cylindrical in shape and has a uniform cross-section along the second main axis 61. Herein, when the cross-section of the envelope 72 of the electrical heating insert 60 is said to be uniform along the second main axis 61 , it is meant that the cross-section is uniform enough along the second main axis 61 to limit the deformation of the insert 60 or a part thereof after a rotation of the insert 60 around the second main axis 61 , so as to reduce a risk of damage for the insert 60 or a part thereof after the rotation. In addition, a uniform envelope 72 of the electrical heating insert 60 along the second main axis 61 facilitates the manipulation of the insert 60 with the tool 80.

[0126] In an embodiment, the tool 80 comprises at least two bars 82 substantially parallel to the third main axis 81 and linked together by at least one segment 83. The at least two bars82 being substantially parallel to the third main axis 81, they are also substantially parallel to each other. Therefore, said at least two bars 82 are also referred to herein as the parallel bars 82. The at least one segment 83 is preferably transverse or perpendicular to the parallel bars 82. Preferably, the parallel bars 82 are linked together by a plurality of segments 83, which increases the rigidity and the robustness of the tool 80. Preferably, a segment 83 is formed by a plurality of sub-segments. More preferably, a segment 83 is a curved segment, which may improve the conformation of the tool 80 with a wall 24 of the radiant housing 18. In this embodiment, the tool 80 may also be referred to as a ladder. An advantage of this embodiment, wherein the tool 80 is configured as a ladder, is to reduce or limit the ability of the tool 80 to block the energy radiated by the electrical heating insert 60 during operation thanks to the reduced surface area covered by the tool 80.

[0127] More generally, when the tool 80 is said to be configured as a ladder, it is meant that the tool 80 has a reduced surface area, so as to reduce or limit the ability of the tool 80 to block the energy radiated by the electrical heating insert 60 during operation. In this respect, various configurations of tool 80 may be considered as a ladder as defined herein. As an example, a tool 80 comprising a single bar coupled to one or more transverse segments may be considered as a ladder. As another example, a plate comprising one or more openings through which radiated energy can pass may be considered as a ladder.

[0128] When the tool 80 is configured as a ladder, the electrical heating insert 60 comprised in the radiant housing 18 may be placed on the tool 80 by first inserting the tool 80 into the radiant housing 18 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18, and then rotating the radiant housing 18 around the first main axis 23 until the electrical heating insert 60 rests on the tool 80.

[0129] Fig. 12 schematically represents by way of example a set 17 comprising a tool 80 for manipulating an electrical heating insert 60 arranged in a radiant housing 18 according to this embodiment. The radiant housing 18 represented in Fig. 12 extends along a first main axis 23. The radiant housing 18 of Fig. 12 has a cylindrical shape. Said radiant housing 18 may be for example a radiant tube. In particular, the radiant housing 18 of Fig. 12 may be the radiant housing 18 represented in Fig. 9. Fig. 12 represents a cut of the set 17 made transversally, or in other words perpendicularly, to the first main axis 23 of the radiant housing 18. In the representation of Fig. 12, the electrical heating insert 60 is placed on the tool 80, which corresponds to the maintenance configuration of the set 17. More precisely, the tool 80 is arranged between the electrical heating insert 60 and a wall 24 of the radiant housing 18. The electrical heating insert 60 represented in Fig. 12 extends along a second main axis 61. Thesecond main axis 61 of the electrical heating insert 60 is parallel to the first main axis 23 of the radiant housing 18. The tool 80 represented in Fig. 12 extends along a third main axis 81. The third main axis 81 of the tool 80 is parallel to the first main axis 23 of the radiant housing 18. The tool 80 of Fig. 12 comprises two bars 82 parallel to the third main axis 81. The two parallel bars 82 are linked together by a segment 83. The segment 83 is transverse to the parallel bars 82. The segment 83 is a curved segment. Fig. 12 illustrates that such a curved segment may improve the conformation of the tool 80 with the wall 24 of the radiant housing 18. The electrical heating insert 60 of Fig. 12 comprises an electrical heating conductor 62 in the shape of a plurality of rods. The electrical heating insert 60 of Fig. 12 also comprises a support element 64 for supporting the electrical heating conductor 62. The support element 64 is made of ceramic material, which may be brittle. The electrical heating insert 60 of Fig. 12 also comprises a central support bar 68 on which the support element 64 is mechanically coupled. The central support bar 68 is made of refractory steel. The central support bar 68 is protected from the heat emitted by the electrical heating conductor 62 by a sheath 69 made of ceramic material. In particular, the electrical heating insert 60 of Fig. 12 may be the electrical heating insert 60 represented in Fig. 10.

[0130] In an embodiment, the set 17 is configured such that the tool 80 remains in the radiant housing 18 during operation, with no contact between the tool 80 and an inner surface 58 of the radiant housing 18. An advantage of avoiding contact between the tool 80 and the inner surface 58 of the radiant housing 18 during operation is to avoid that the tool 80 sticks to the radiant housing 18. Indeed, due to the high temperature in the radiant housing 18 during operation, the tool 80 or part thereof may partially melt and therefore stick to or merge with an inner surface 58 of the radiant housing 18. In this embodiment, the tool 80 is advantageously configured as a ladder so as to reduce or limit the ability of the tool 80 to block the energy radiated by the electrical heating insert 60 during operation thanks to the reduced surface area covered by the tool 80.

[0131] Preferably, the tool 80 is supported by the electrical heating insert 60 and lies in a gap 56 between the electrical heating insert 60 and the inner surface 58 of the radiant housing 18 during operation. The gap 56 is at least 1mm wide, preferably at least 5mm wide, more preferably at least 10mm wide. An advantage of this configuration is that the energy radiated by the electrical heating insert 60 during operation and that is blocked by the tool 80 is not directed towards the strip 12 but rather towards neighboring radiant housings 18 in the furnace 10 in a case where radiant housings 18 are positioned vertically, i.e. on top of each other, as illustrated in Fig. 1 by way of example. Therefore, the blocking by the tool 80 of part of theradiated energy has only a reduced impact or even no impact on the heating of the strip 12 in this case.

[0132] Preferably, the tool 80 is mechanically coupled to the electrical heating insert 60. An advantage of this configuration is to ensure that the tool 80 remains in place during operation and in particular that the tool 80 does not come into contact with an inner surface 58 of the radiant housing 18 during operation.

[0133] In an embodiment, the tool 80 comprises a plate 84 substantially conforming to the wall 24 of the radiant housing 18. The plate 84 may be curved, or in other words rounded, which may improve its conformation with the wall 24 of the radiant housing 18. In this embodiment, the tool 80 may also be referred to as a plate. An advantage of this embodiment, wherein the tool 80 is configured as a plate, is that the tool 80 is able to manipulate a large variety of electrical heating inserts 60, i.e. electrical heating inserts 60 with a large variety of shapes and configurations.

[0134] When the tool 80 is configured as a plate, the electrical heating insert 60 comprised in the radiant housing 18 may be placed on the tool 80 by first inserting the tool 80 into the radiant housing 18 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18, and then rotating the radiant housing 18 around the first main axis 23 until the electrical heating insert 60 rests on the tool 80. Alternatively, the electrical heating insert 60 comprised in the radiant housing 18 may be placed on the tool 80 configured as a plate by first inserting the tool 80 into the radiant housing 18 in the gap 56, and then sliding the tool 80 between the electrical heating insert 60 and the wall 24 of the radiant housing 18 without rotating the radiant housing 18 until the electrical heating insert 60 rests on the tool 80. More precisely, in this case the tool 80 is slid between the electrical heating insert 60 and the wall 24 of the radiant housing 18 by rotating the tool 80 around the first main axis 23 without rotating the radiant housing 18.

[0135] Fig. 13 schematically represents by way of example a set 17 comprising a tool 80 for manipulating an electrical heating insert 60 arranged in a radiant housing 18 according to this embodiment. Fig. 13 is similar to Fig. 12 and the description of the radiant housing 18 and the electrical heating insert 60 of Fig. 12 also applies to Fig. 13. The tool 80 represented in Fig. 13 extends along a third main axis 81. In Fig. 13, the third main axis 81 of the tool 80 is parallel to the first main axis 23 of the radiant housing 18. The tool 80 of Fig. 13 comprises a plate 84 which is a curved plate substantially conforming to the wall 24 of the radiant housing 18.

[0136] In an embodiment, the tool 80 comprises at least two parts 85, each one of said at least two parts 85 extending along a respective main axis 851, 852 substantially parallel to the third main axis 81 of the tool 80. In this embodiment, the at least one support element 64 of the electrical heating insert 60 comprises a respective groove 86 for each one of the at least two parts 85 for receiving said parts 85. Preferably, each groove 86 is substantially parallel to the third main axis 81.

[0137] Preferably, each one of the at least two parts 85 comprises articulated segments forming a chain. In this embodiment, the tool 80 may also be referred to as a chain. An advantage of this embodiment, wherein the tool 80 is configured as a chain, is to allow the tool 80 to be inserted in a deformed radiant housing 18, in particular in a bent radiant housing 18. Another advantage of this embodiment is that the tool 80 is able to manipulate a large variety of electrical heating inserts 60, i.e. electrical heating inserts 60 with a large variety of shapes and configurations.

[0138] Preferably, a cross-section of each one of said at least two parts 85 transverse to its respective axis 851 , 852 comprises a first length 87 along a first direction 88 longer than a second length 89 along a second direction 90 transverse to the first direction 88. An advantage of this embodiment is to allow the electrical heating insert 60 to be placed on the tool 80 thanks to a rotation of each part 85 of the tool 80 around its respective axis 851 , 852. The depth of each groove 86 is at least 1mm, preferably at least 5mm, more preferably at least 10mm. In order to allow the electrical heating insert 60 to be lifted by the tool 80, the first length 87 of each part 85 must be at least 1mm longer than the second length 89, preferably at least 5mm longer, more preferably at least 10mm longer.

[0139] When the tool 80 is configured as a chain, the electrical heating insert 60 comprised in the radiant housing 18 may be placed on the tool 80 by first inserting each one of the at least two parts 85 of the tool 80 into the radiant housing 18 in a respective aperture formed between a respective groove 86 of the at least one support element 64 of the electrical heating insert 60 and the wall 24 of the radiant housing 18, and then rotating each one of said at least two parts 85 around its respective axis 851, 852 until the electrical heating insert 60 rests on the tool 80.

[0140] Fig. 14 schematically represents by way of example a set 17 comprising a tool 80 for manipulating an electrical heating insert 60 arranged in a radiant housing 18 according to this embodiment. Fig. 14 is similar to Fig. 12 and the description of the radiant housing 18 and the electrical heating insert 60 of Fig. 12 also applies to Fig. 14. The tool 80 represented in Fig. 14 extends along a third main axis 81. In Fig. 14, the third main axis 81 of the tool 80 isparallel to the first main axis 23 of the radiant housing 18. The tool 80 of Fig. 14 comprises two parts 85 extending along a respective main axis 851 , 852 parallel to the third main axis 81. In addition, the support element 64 of the electrical heating insert 60 comprises a groove 86 for each one of the two parts 85 for receiving said parts 85. In Fig. 14, each groove 86 is parallel to the third main axis 81.Insertion of an electrical heating insert into a radiant housing

[0141] An electrical heating insert 60 comprised in a set 17 may be inserted into a radiant housing 18 for an industrial furnace 10 with a tool 80 in a maintenance operation of the set 17. An advantage of manipulating the electrical heating insert 60 with the tool 80 is to avoid damaging the electrical heating insert 60 or a part thereof during the maintenance operation.

[0142] The maintenance operation of the set 17 wherein the electrical heating insert 60 is inserted into the radiant housing 18 may comprise the following steps:(a) providing a set 17 comprising a radiant housing 18, an electrical heating insert 60 arranged in the radiant housing 18, and a tool 80 for manipulating the electrical heating insert 60;(b) placing the electrical heating insert 60 on the tool 80;(c) translating the electrical heating insert 60 resting on the tool 80 along the first main axis 23 such as to insert the electrical heating insert 60 into the radiant housing 18;(d) placing the electrical heating insert 60 on the radiant housing 18 such that the electrical heating insert 60 no longer rests on the tool 80;(e) removing the tool 80 from the radiant housing 18.

[0143] Said steps are executed preferably, but not necessarily, in the indicated order, i.e. the alphabetical order. Some of the steps described hereinabove may be optional. In particular, the step (e) is optional because the tool 80 may be left in the radiant housing 18 after the maintenance operation.

[0144] An advantage of inserting the electrical heating insert 60 into the radiant housing 18 with the tool 80 is to avoid damaging the electrical heating insert 60 or a part thereof during its insertion into the radiant housing 18.

[0145] Preferably, the step (d) of placing the electrical heating insert 60 on the radiant housing 18 comprises the following step:(d’) rotating the radiant housing 18 around the first main axis 23 until the electrical heating insert 60 no longer rests on the tool 80.

[0146] An advantage of step (d’) is to allow the electrical heating insert 60 to be easily placed on the radiant housing 18.

[0147] When the tool 80 comprises a plate 84 substantially conforming to the wall 24 of the radiant housing 18, or in other words when the tool 80 is configured as a plate, the step (d) of placing the electrical heating insert 60 on the radiant housing 18 preferably comprises the following step:(d”) rotating the tool 80 around the first main axis 23 until the electrical heating insert 60 no longer rests on the tool 80.

[0148] An advantage of step (d”) is to allow the electrical heating insert 60 to be placed on the radiant housing 18 without having to manipulate the radiant housing 18, in particular without having to rotate the radiant housing 18 around the first main axis 23.

[0149] When the tool 80 comprises at least two parts 85 and the at least one support element 64 of the electrical heating insert 60 comprises a respective groove 86 for each one of the at least two parts 85 for receiving said parts 85 as described hereinbefore, and in particular when the tool 80 is configured as a chain, the step (d) of placing the electrical heating insert 60 on the radiant housing 18 preferably comprises the following step:(d’”) rotating each one of the at least two parts 85 of the tool 80 around its respective axis 851 , 852 until the electrical heating insert 60 no longer rests on the tool 80.

[0150] An advantage of step (d’”) is to allow the electrical heating insert 60 to be placed on the radiant housing 18 without having to manipulate the radiant housing 18, in particular without having to rotate the radiant housing 18 around the first main axis 23.Removal of an electrical heating insert from a radiant housing

[0151] An electrical heating insert 60 comprised in a set 17 may be removed from a radiant housing 18 for an industrial furnace 10 with a tool 80 in a maintenance operation of the set 17. An advantage of manipulating the electrical heating insert 60 with the tool 80 is to avoid damaging the electrical heating insert 60 or a part thereof during the maintenance operation.

[0152] The maintenance operation of the set 17 wherein the electrical heating insert 60 is removed from the radiant housing 18 is analogous to the maintenance operation of the set 17 wherein the electrical heating insert 60 is inserted into the radiant housing 18, with some steps performed in reverse order. Therefore, the two maintenance operations are two aspects of a same invention, forming a single general inventive concept. In particular, both maintenance operations allow the electrical heating insert 60 to be manipulated with a reduced risk of damage for the electrical heating insert 60 or a part thereof.

[0153] The maintenance operation of the set 17 wherein the electrical heating insert 60 is removed from the radiant housing 18 may comprise the following steps:(a) providing a set 17 comprising a radiant housing 18, an electrical heating insert 60 arranged in the radiant housing 18, and a tool 80 for manipulating the electrical heating insert 60;(b) placing the electrical heating insert 60 on the tool 80;(c) translating the electrical heating insert 60 resting on the tool 80 along the first main axis 23 such as to remove the electrical heating insert 60 from the radiant housing 18.

[0154] Said steps are executed preferably, but not necessarily, in the indicated order, i.e. the alphabetical order. Some of the steps described hereinabove may be optional.

[0155] Preferably, the tool 80 may be inserted in the radiant housing 18 prior to the step (b) of placing the electrical heating insert 60 on the tool 80. Alternatively, the tool 80 may be already present in the radiant housing 18 before the maintenance operation.

[0156] An advantage of removing the electrical heating insert 60 from the radiant housing 18 with the tool 80 is to avoid damaging the electrical heating insert 60 or a part thereof during its removal from the radiant housing 18.

[0157] Preferably, the step (b) of placing the electrical heating insert 60 on the tool 80 comprises the following step:(b’) rotating the radiant housing 18 around the first main axis 23 until the electrical heating insert 60 rests on the tool 80.

[0158] An advantage of step (b’) is to allow the electrical heating insert 60 to be easily placed on the tool 80.

[0159] Preferably, the step (b) of placing the electrical heating insert 60 on the tool 80 comprises the following steps:(b”1) inserting the tool 80 or a part thereof into the radiant housing 18 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18;(b”2) rotating the radiant housing 18 around the first main axis 23 until the electrical heating insert 60 rests on the tool 80.

[0160] An advantage of steps (b”1) and (b”2) is to allow the electrical heating insert 60 to be easily placed on the tool 80.

[0161] When the tool 80 comprises a plate 84 substantially conforming to the wall 24 of the radiant housing 18, or in other words when the tool 80 is configured as a plate, the step (b) of placing the electrical heating insert 60 on the tool 80 preferably comprises the following steps:(b’”1) inserting the tool 80 or a part thereof into the radiant housing 18 in a gap 56 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18;(b’”2) rotating the tool 80 around the first main axis 23 until the electrical heating insert 60 rests on the tool 80.

[0162] An advantage of steps (b’”1) and (b’”2) is to allow the electrical heating insert 60 to be placed on the tool 80 without having to manipulate the radiant housing 18, in particular without having to rotate the radiant housing 18 around the first main axis 23.

[0163] When the tool 80 comprises at least two parts 85 and the at least one support element 64 of the electrical heating insert 60 comprises a respective groove 86 for each one of the at least two parts 85 for receiving said parts 85 as described hereinbefore, and in particular when the tool 80 is configured as a chain, the step (b) of placing the electrical heating insert 60 on the tool 80 preferably comprises the following steps:(b””1) inserting each one of the at least two parts 85 of the tool 80 or a part thereof into the radiant housing 18 in a respective aperture formed between a respective groove 86 of the at least one support element 64 of the electrical heating insert 60 and the wall 24 of the radiant housing 18;(b””2) rotating each one of said at least two parts 85 around its respective axis 851 , 852 until the electrical heating insert 60 rests on the tool 80.

[0164] An advantage of steps (b””1) and (b””2) is to allow the electrical heating insert 60 to be placed on the tool 80 without having to manipulate the radiant housing 18, in particular without having to rotate the radiant housing 18 around the first main axis 23.

[0165] The two maintenance operations of the set 17 described hereinabove, i.e. the maintenance operations wherein the electrical heating insert 60 is respectively inserted into and removed from the radiant housing 18, may be combined such as to form a combined maintenance operation. Such a combined maintenance operation may allow an electrical heating insert 60 to be removed from a radiant housing 18, and then inserted into the radiant housing 18, for instance for a replacement or a repair of a damaged or a defective electrical heating insert 60, or for a replacement or a repair of a damaged or a defective radiant housing 18.Electrical heating device

[0166] Generally, an electrical heating insert 60 arranged in or on a radiant housing 18 for an industrial furnace 10 may be configured for operating in a plurality of angular positions relative to a main axis 61 so as to allow a rotation of the electrical heating insert 60 around themain axis 61 with a reduced risk of damage for the electrical heating insert 60 or a part thereof. To this end, there may be provided an electrical heating insert 60 for an industrial furnace 10, the electrical heating insert 60 extending along a main axis 61 and comprising a first end 601 and a second end 602. The electrical heating insert 60 may be configured for being arranged in a radiant housing 18. More precisely, the electrical heating insert 60 may be configured for being supported in or on the radiant housing 18. The main axis 61 of the electrical heating insert 60 corresponds to the second main axis 61 as described hereinbefore. Preferably, the electrical heating insert 60 is neither rigid nor self-supporting. Instead, the electrical heating insert 60 is supported within the radiant housing 18 via at least one support element 64, as described hereinafter. In other words, the electrical heating insert 60 rests within the radiant housing 18. This allows the electrical heating insert 60 to deform in conjunction with any deformation of the radiant housing 18.

[0167] The electrical heating insert 60 may further comprise an electrical heating conductor 62. The electrical heating conductor 62 may have for example the shape of one or more bars, or one or more rods, or also have a helical shape. Other shapes of the electrical heating conductor 62 are possible. The electrical heating conductor 62 may also be referred to herein as an electrical heating resistor, or simply an electrical resistor. The electrical heating conductor 62 may be made of an electrically conductive material such as for example: a nickel- chromium-based alloy (NiCr alloy) suitable for use at temperatures up to 1250°C; a ferritic iron- chromium-aluminium-based alloy (FeCrAI alloy) suitable for use at temperatures up to 1425°C, which combines excellent resistance to oxidation and hot corrosion with high creep resistance and superior form stability; a ceramic material such as silicon carbide (SiC) suitable for use at temperatures comprised between 600°C and 1600°C, or molybdenum disilicide (MoSi2).

[0168] The electrical heating insert 60 may further comprise at least one support element 64 for supporting the electrical heating conductor 62. The at least one support element 64 may be made of a heat-resistant and electrically insulating material such as a ceramic material. The support element 64 may have several functions. A first function of the support element 64 is to support the electrical heating conductor 62. In this regard, the electrical heating conductor 62 may be supported for example in one or several holes or bores of the support element 64, or in one or several brackets of the support element 64, or also wrapped around the support element 64. For example, the electrical heating conductor 62 may be helically wrapped around one or more bars of the support element 64. A second function of the support element 64 is to support the electrical heating insert 60 within the radiant housing 18. When the insert 60 is placed in or on a radiant housing 18, the electrical heating conductor 62 is preferablyelectrically insulated from the radiant housing 18, more precisely from a wall 24 of the radiant housing 18 on which the insert 60 is supported, thanks to the at least one support element 64.

[0169] The electrical heating insert 60 may comprise a plurality of support elements 64 for supporting the electrical heating conductor 62.

[0170] The electrical heating insert 60 may further comprise a heat stopper 66. The heat stopper 66 may have the shape of a cylinder. The heat stopper 66 may be made of a refractory material. Said refractory material may be rigid or flexible. A rigid refractory material may be for example a ceramic material, or a material comprising compressed refractory fibers. A flexible refractory material may be for example a fibrous material such as glass wool or rock wool. Generally, the heat stopper 66 may be made of a different material from the material of the support element 64. The heat stopper 66 may also be referred to herein as a bung, or a bung heat stopper. When the electrical heating insert 60 is arranged in or on a radiant housing 18, the heat stopper 66 prevents at least partially the heat emitted by the electrical heating conductor 62 from escaping out of an interior volume 29 of the radiant housing 18. In addition, the heat stopper 66 may also support the electrical heating conductor 62 or a part thereof, in which case the heat stopper 66 is preferably electrically insulating. Finally, the heat stopper 66 is preferably arranged at one end 601 , 602 of the electrical heating insert 60. Even more preferably, the heat stopper 66 is arranged at the end 601 of the electrical heating insert 60 that is close to an open end 183 of a radiant housing 18 in which the insert 60 is comprised.

[0171] The electrical heating insert 60 may be configured for operating in a plurality of angular positions relative to the second main axis 61 , so as to allow a rotation of the electrical heating insert 60 around the second main axis 61 with a reduced risk of damage for the electrical heating insert 60 or a part thereof, such as an electrical heating conductor 62 comprised in the insert 60. Indeed, a deformation of the insert 60 or a part thereof may damage the insert 60 during operation or during maintenance. As an example, a deformation of a conductor 62 may cause additional stresses to arise in the conductor 62 during operation, thereby increasing the creep of the conductor 62 during operation, and therefore reducing the service life of an insert 60 comprising the conductor 62. As another example, a conductor 62 may be brittle and therefore may be damaged by a deformation such as a flexion or a torsion during maintenance. Therefore, by reducing the deformation of the electrical heating insert 60 or a part thereof after a rotation of the insert 60 around the second main axis 61 , as enabled by the electrical heating insert 60 described herein, the risk of damage for the insert 60 may be reduced during operation or during maintenance.

[0172] Herein, when an electrical heating insert 60 is said to be configured for operating in a plurality of angular positions relative to the second main axis 61 , it is meant that the insert 60 may operate in each one of several angular positions, or orientations, relative to the second main axis 61. The plurality of angular positions comprises at least two different angular positions. Therefore, the invention also applies in the case of an electrical heating insert 60 having a cross-section transverse to the second main axis 61 that is non-circular in shape, as long as said cross-section enables a stable support of the insert 60 in at least two different angular positions relative to the second main axis 61. For instance, said cross-section may have a square shape, or an hexagonal shape, or an octagonal shape. Other shapes are possible within the scope of the invention. Preferably, an envelope 72 of the electrical heating insert 60 is substantially cylindrical in shape and has a uniform cross-section along the second main axis 61 of the electrical heating insert 60, such as to allow the electrical heating insert 60 to be operated in a large number of angular positions.

[0173] An advantage of being able to operate an electrical heating insert 60 in a plurality of angular positions relative to the second main axis 61 is to facilitate a maintenance operation for extending the service life of the radiant housing 18 in which the insert 60 is arranged. Indeed, the radiant housing 18 may deform, and in particular sag or bend, during operation due to creep and / or fatigue. In order to compensate for such deformation, the radiant housing 18 may be periodically rotated around the first main axis 23 during a maintenance operation, thereby extending the service life of the radiant housing 18. Rotating the radiant housing 18 with the electrical heating insert 60 inside facilitates the maintenance operation by avoiding additional steps of insertion or removal of the insert 60 into or from the housing 18. However, this is possible only if the electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis 61. Indeed, during the rotation of the radiant housing 18 around the first main axis 23, the electrical heating insert 60 comprised in the housing 18 also rotates around the second main axis 61 , thereby taking a new angular position relative to the second main axis 61.

[0174] However, electrical heating inserts of the prior art are configured for operating in a single angular position relative to a main axis. In particular, electrical heating inserts of the prior art are not configured for being rotated around a main axis. Therefore, after a rotation of an electrical heating insert of the prior art around a main axis, the insert may be positioned in such a way as to present a risk of damage for the insert or a part thereof. For example, an electrical heating conductor comprised in the insert may be at risk of being deformed after the rotation, and thus damaged during operation of the insert because of additional stresses due to thedeformation. Such deformation may be for example a flexion or a torsion. Such deformation may occur for example due to gravity, for instance when a cantilevered part of the insert bends under its own weight, or due to mechanical interactions between parts of the insert, for instance when a conductor of the insert is pushed or pulled by a support element or a heat stopper of the insert.

[0175] Fig. 15 schematically illustrates an electrical heating insert 100 according to the prior art arranged in a radiant housing 18. The radiant housing 18 of Fig. 15 is a closed radiant housing 18 comprising an open end 183 with a flange 40 and a closed end 184. The electrical heating insert 100 of the prior art is supported on a wall 24 of the radiant housing 18. The electrical heating insert 100 extends along a main axis 101. The electrical heating insert 100 comprises an electrical heating conductor 102 in the shape of a plurality of rods. The electrical heating conductor 102 is supported by a plurality of support elements 104. The electrical heating insert 100 further comprises a heat stopper 106. The heat stopper 106 is configured for blocking the heat emitted by the electrical heating conductor 102. Therefore, the size of the heat stopper 106 is close to the size of the open end 183 of the radiant housing 18, so as to minimize a gap 108 between the heat stopper 106 and the radiant housing 18. In addition, the size of the heat stopper 106 is larger than the size of the support elements 104, as is usually the case for an electrical heating insert 100 according to the prior art. Moreover, the heat stopper 106 supports a part of the electrical heating conductor 102. As represented in Fig. 15, the electrical heating conductor 102 is not supported in the middle of the heat stopper 106 but rather in an eccentric position.

[0176] Fig. 16 repeats the representation of Fig. 15 after a rotation of the electrical heating insert 100 around the main axis 101 by an angle of rotation equal to 180°. Due to the eccentric position of the electrical heating conductor 102 relative to the heat stopper 106, the electrical heating conductor 102 is deformed, and more precisely flexed, after the rotation of the electrical heating insert 100, as designated by reference 110. This illustrates a deficiency of electrical heating inserts of the prior art, which are not configured for operating in a plurality of angular positions. Fig. 16 illustrates that an electrical heating conductor 102 comprised in an electrical heating insert 100 of the prior art may be deformed after the rotation, and thus damaged during operation of the insert 100 because of additional stresses due to the deformation. In Fig. 16, the electrical heating conductor 102 is deformed by flexion.

[0177] In contrast, the heat stopper 66 comprised in the electrical heating insert 60 has a size close to the size of the at least one support element 64 of the insert 60, so as to allow the insert 60 to be rotated around the second main axis 61 within the radiant housing 18 with areduced risk of damage for the insert 60 or a part thereof. This facilitates a maintenance operation during which the radiant housing 18 is rotated around the first main axis 23 in order to compensate for a deformation of the housing 18 and therefore extend the service life of the radiant housing 18. The housing 18 may be rotated with or without the insert 60 inside it, as detailed below.

[0178] In a first case where the housing 18 is rotated with the insert 60 inside it, the insert 60 rolls within the housing 18 when the housing 18 is rotated, thus taking a new angular position relative to the second main axis 61. In this case, all sections of the insert 60 roll uniformly within the housing 18 when the housing 18 is rotated around the first main axis 23, thereby reducing the risk of a damage by deformation (e.g. flexion or torsion) of the insert 60 or a part thereof.

[0179] In a second case where the insert 60 is removed from the housing 18 prior to the rotation of the housing 18, the insert 60 is advantageously manipulated with a tool 80 to avoid damaging the insert 60 or a part thereof, as described hereinbefore. In this case, the insert 60 may be placed on the tool 80 by a rotation of the housing 18 around the first main axis 23. Similarly, in order to reinstall the insert 60 within the housing 18 with the tool 80 after the rotation of the housing 18, the insert 60 may be removed from the tool 80 by a rotation of the housing 18 around the first main axis 23.

[0180] So in both cases above, the insert 60 needs to be rotated around the second main axis 61 within the radiant housing 18, and therefore take a new angular position relative to the second main axis 61 , which is enabled by an electrical heating insert 60 as described herein, i.e. that is able to operate in a plurality of angular positions relative to the second main axis 61.

[0181] Finally, there may be a gap 56 between the heat stopper 66 and an inner surface 58 of the radiant housing 18. An advantage of this gap 56 is to allow the insertion and / or removal of a tool 80 for manipulating the electrical heating insert 60.

[0182] Fig. 17 schematically illustrates an electrical heating insert 60 arranged in a radiant housing 18. The radiant housing 18 is a closed radiant housing 18 comprising an open end 183 with a flange 40 and a closed end 184. The electrical heating insert 60 is supported on a wall 24 of the radiant housing 18. The electrical heating insert 60 extends along a second main axis 61 and comprises a first and 601 and a second end 602. The electrical heating insert 60 further comprises an electrical heating conductor 62 in the shape of a plurality of rods. The electrical heating conductor 62 is supported by a plurality of support elements 64. The electrical heating insert 60 further comprises a heat stopper 66. The heat stopper 66 is configured for blocking at least part of the heat emitted by the electrical heating conductor 62. The heatstopper has a size close to the size of the support elements 64 of the insert 60, thereby leaving a gap 56 between the heat stopper 66 and an inner surface 58 of the radiant housing 18. Moreover, an envelope 72 of the electrical heating insert 60 is represented in Fig. 17. The envelope 72 is a closed surface surrounding the electrical heating insert 60 and delimiting an interior volume 78 of the electrical heating insert 60.

[0183] In an embodiment, the heat stopper 66 is configured such that the deformation of the electrical heating insert 60 ora part thereof (e.g. the electrical heating conductor 62) relative to the at least one support element 64 and measured in a plane perpendicular to the second main axis 61 is limited to a difference between an inner diameter 96 of the radiant housing 18 and a diameter 94 of a first circle 74 circumscribed to the at least one support element 64 in any of said angular positions. An inner diameter 96 of the radiant housing 18 is a diameter of a circle inscribed in the radiant housing 18. Herein, a circle circumscribed to an object or a circle inscribed in an object is assumed to be tangent in at least one point to the object. The first circle 74 of this embodiment is represented by way of example in Fig. 18.

[0184] Generally, said deformation may be larger than said difference, in particular in a case where the heat stopper 66 is deformed with a combination of flexion and torsion relative to the second main axis 61. Therefore, limiting said deformation to said difference allows the electrical heating insert 60 to be rotated around the second main axis 61 with a reduced risk of damage for the electrical heating insert 60 or a part thereof, which is an advantage of this embodiment.

[0185] Preferably, said deformation is limited to half of said difference, in order to further reduce the risk of damage. More preferably, said deformation is limited to a quarter of said difference, in order to even further reduce the risk of damage.

[0186] When said difference is substantially equal to zero, this embodiment becomes equivalent to another embodiment wherein the diameter 94 of the first circle 74 circumscribed to the at least one support element 64 is substantially equal to a diameter 95 of a second circle 75 circumscribed to the heat stopper 66, the centers of said first and second circles 74, 75 lying on the second main axis 61.

[0187] Examples of heat stoppers 66 configured according to this embodiment are provided below.

[0188] A first example is a heat stopper 66 in the shape of a cylinder extending along the second main axis 61 and with substantially the same diameter as the first circle 74 circumscribed to the at least one support element 64. Indeed, in such a case the deformationof the electrical heating insert 60 or a part thereof relative to the at least one support element64 is close to zero.

[0189] A second example is a heat stopper 66 in the shape of a cylinder extending along the second main axis 61 and with a larger or smaller diameter than the diameter of the first circle 74 but such that said deformation remains within the range of deformation permitted in this embodiment.

[0190] A third example is a heat stopper 66 made of a flexible refractory material such as a fibrous material, which allows a limited deformation relative to the at least one support element 64 within the range of deformation permitted in this embodiment.

[0191] In an embodiment, a diameter 94 of a first circle 74 circumscribed to the at least one support element 64 is substantially equal to, and preferably equal to, a diameter 95 of a second circle 75 circumscribed to the heat stopper 66, the centers of said first and second circles 74, 75 lying on the second main axis 61. Herein, the terms “substantially equal” and “equal” are to be interpreted as being as equal as possible within manufacturing tolerances. The first and second circles 74, 75 of this embodiment are preferably comprised in respective planes substantially transverse to the second main axis 61. The fact that said first and second circles 74, 75 are of the same diameter does not necessarily imply that the at least one support element 64 and the heat stopper 66 are circular in shape or have a circular cross-section with respect to the second main axis 61. Other cross-sectional shapes are possible within the scope of this embodiment, such as for instance an hexagon, an octagon, or a circular shape comprising one or more grooves, as represented by way of example in Figures 20 to 25. Generally, the at least one support element 64 and the heat stopper 66 may have different shapes and in particular cross-sections of different shapes with respect to the second main axis 61. Herein, a circle circumscribed to an object is assumed to be tangent in at least one point to the object. The first and second circles 74, 75 of this embodiment are represented by way of example in Fig. 18.

[0192] In this embodiment, an envelope 72 of the electrical heating insert 60 is substantially cylindrical in shape and has a uniform cross-section along the second main axis 61. An advantage of this embodiment is that the electrical heating insert 60 may operate in a plurality of angular positions relative to the second main axis 61 with a reduced risk of damage for the insert 60 or a part thereof. Indeed, for any of said angular positions, the insert 60 may be supported within the radiant housing 18 with a reduced or even no deformation of the insert 60 or a part thereof.

[0193] Fig. 18 schematically represents by way of example an electrical heating insert 60 according to this embodiment. The electrical heating insert 60 extends along a second main axis 61 and comprises a first end 601 and a second end 602. The electrical heating insert 60 also comprises an electrical heating conductor 62 comprising a plurality of rods, a plurality of support elements 64 for supporting the electrical heating conductor 62, and a heat stopper 66 arranged at one end 601 of the electrical heating insert 60. In Fig. 18, the support elements 64 have a non-circular shape and comprise a plurality of grooves, whereas the heat stopper 66 is essentially cylindrical in shape. However, the first circle 74 circumscribed to one of the support elements 64 and the second circle 75 circumscribed to the heat stopper 66 have substantially the same diameter, with the centers of said first and second circles 74, 75 lying on the second main axis 61 of the insert 60. Therefore, an envelope 72 of the insert 60 is substantially cylindrical in shape and has a uniform cross-section along the second main axis 61.

[0194] In an embodiment, the heat stopper 66 and the at least one support element 64 are both substantially circular in cross-section with respect to the second main axis 61. In other words, the heat stopper 66 and the at least one support element 64 both have a cross-section transverse to the second main axis 61 of substantially circular shape. An advantage of this embodiment is to allow the electrical heating insert 60 to be operated in a large number of angular positions relative to the second main axis 61. In other words, this embodiment allows the electrical heating insert 60 by a large number of angles of rotation around the second main axis 61 with a reduced or even no risk of damage for the insert 60 or a part thereof.

[0195] In an embodiment, the at least one support element 64 is made of a heat-resistant and electrically insulating material. Said material may be a refractory material such as a ceramic material. An advantage of this embodiment is to allow the radiant housing 18 to be electrically insulated from the electrical heating conductor 62 thanks to the at least one support element 64. More precisely, the at least one support element 64 allows the wall 24 of the radiant housing 18 on which the insert 60 is supported to be electrically insulated from the electrical heating conductor 62. Another advantage of this embodiment is that the at least one support element 64 may be used as a spacer between different parts of the electrical heating conductor 62.

[0196] In an embodiment, the electrical heating insert 60 further comprises a support bar 68 extending along the second main axis 61 and mechanically coupled to the at least one support element 64 and to the heat stopper 66. In the case of a plurality of support elements 64, each support element 64 in the plurality may be mechanically coupled to the support bar 68, which ensures a spacing between each support element 64 in the plurality. The supportbar 68 may be made of a heat-resistant material such as refractory steel. An advantage of the support bar 68 is to improve the mechanical coupling between the at least one support element 64 and the heat stopper 66. In addition, no electric current flows through the support bar 68. Therefore, the support bar 68 is cooler than the electrical heating conductor 62, which improves the mechanical strength of the support bar 68.

[0197] The support bar 68 may occupy a central position in the electrical heating insert 60, for instance along the second main axis 61 of the electrical heating insert 60, in which case the support bar 68 may be called a central support bar. An advantage of a central support bar is to improve the robustness of the mechanical coupling between the support bar 68 and the elements coupled to the support bar 68.

[0198] In an embodiment, the electrical heating insert 60 further comprises a sheath 69 for protecting the support bar 68 from the heat emitted by the electrical heating conductor 62. The sheath 69 may have the shape of one or more hollow cylinders, or one or more sleeves, such that it may be put on, or in other words slipped over, the support bar 68. The sheath 69 may be made of a refractory material such as a ceramic material.

[0199] In an embodiment, the electrical heating insert 60 further comprises electrical terminals 70 for electrically coupling the electrical heating insert 60 to an electrical energy source, the electrical terminals 70 being electrically coupled to the electrical heating conductor 62. Preferably, the electrical terminals 70 are arranged at one end 601 , 602 of the electrical heating insert 60, in order to facilitate the access to the electrical terminals 70. More preferably, the electrical terminals 70 are arranged at the end 601 on which the heat stopper 66 is arranged, in order to further facilitate the access to the electrical terminals 70, in particular so that said terminals 70 may be accessed easily from the exterior of the electrical heating insert 60. Even more preferably, the electrical terminals 70 are supported by the heat stopper 66. The electrical terminals 70 are represented by way of example in Fig. 10, Fig. 17, and Fig. 18.

[0200] Preferably, the electrical terminals 70 are arranged along a diameter of the heat stopper 66, i.e. along a diameter of a circle circumscribed to the heat stopper 66, such as the second circle 75.

[0201] In an embodiment, the electrical heating conductor 62 comprises rods of electrically conductive material. Said rods have preferably a thick diameter to improve their mechanical resistance to creep. An advantage of this embodiment is to improve the emissivity of the electrical heating conductor 62, i.e. its ability to radiate energy for heating the industrial furnace 10. Another advantage of this embodiment is to allow the electrical heating conductor 62 to be regularly supported by the support element 64. A further advantage of thisembodiment is that the rods may be well spaced from each other, thereby limiting the risk of electrical arc within the electrical heating conductor 62 and also between the electrical heating conductor 62 and the radiant housing 18.

[0202] Preferably, said rods are electrically connected in series, which facilitates the electrical coupling of the electrical heating conductor 62 to an electrical energy source.

[0203] In an embodiment, the heat stopper 66 and the at least one support element 64 each comprise a groove 76 for receiving a measuring device 51 for measuring a physical property of an interior volume 78 of the electrical heating insert 60. Preferably, the groove 76 is parallel to the second main axis 61 of the electrical heating insert 60. The groove 76 facilitates the insertion of the measuring device 51 within the interior volume 78. An advantage of measuring a physical property of the interior volume 78 of the electrical heating insert 60 is to monitor the status of the electrical heating insert 60 to ensure that it is working as intended and, if necessary, to be able to detect a fault. Another advantage of measuring a physical property of the interior volume 78 of the electrical heating insert 60 is to collect data in order to calibrate an operating model of the electrical heating insert 60. The interior volume 78 is defined herein as the volume comprised within an envelope 72 of the electrical heating insert 60, as represented by way of example in Fig. 17. The groove 76 and the measuring device 51 are represented by way of example in Fig. 18.

[0204] Preferably, the measuring device 51 is a thermocouple for measuring a temperature of the interior volume 78.

[0205] In an embodiment, the measuring device 51 is inserted in the interior volume 78 of the electrical heating insert 60 through a first opening in the heat stopper 66 and a second opening in the at least one support element 64. Preferably, the first and second openings are aligned so as to facilitate the insertion of the measuring device 51. An advantage of this embodiment is to allow the measuring device 51 to be held in place during a rotation of the electrical heating insert 60 around the second main axis 61.

[0206] Preferably, the measuring device 51 is inserted in the interior volume 78 close to the center of the electrical heating insert 60, i.e. close to the second main axis 61.

[0207] Furthermore, there may be provided an electrical heating device 92 for an industrial furnace 10 and comprising a radiant housing 18 extending along a first main axis 23 and an electrical heating insert 60 as described hereinbefore, the electrical heating insert 60 extending along a second main axis 61. The electrical heating insert 60 is arranged in the radiant housing 18 and lies on a wall 24 of the radiant housing 18. The electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis61. The first main axis 23 of the radiant housing 18 and the second main axis 61 of the electrical heating insert 60 are substantially parallel, or even merged. The radiant housing 18 is preferably a closed radiant housing 18. The invention generally applies for radiant housings 18 having a cross-section transverse to the first main axis 23 that is non-circular in shape. The electrical heating device 92 is represented by way of example in Fig. 17 and Fig. 19.

[0208] In an embodiment, the radiant housing 18 is configured for operating in a plurality of angular positions relative to the first main axis 23.

[0209] In an embodiment, the radiant housing 18 is substantially cylindrical in shape. In this embodiment, the radiant housing 18 is preferably a radiant tube.

[0210] In an embodiment, the electrical heating insert 60 is configured for being inserted into the radiant housing 18. In order for the electrical heating insert 60 to be inserted into the radiant housing 18, an outer diameter of the electrical heating insert 60, i.e. a diameter of a circle circumscribed to the electrical heating insert 60, must be smaller than an inner diameter of the radiant housing 18, i.e. a diameter of a circle inscribed in the radiant housing 18. Herein, a circle circumscribed to an object or a circle inscribed in an object is assumed to be tangent in at least one point to the object. Preferably, the electrical heating insert 60 may also be configured for being removed from the radiant housing 18, for instance for a maintenance operation or for a repair. In particular, the electrical heating insert 60 may be inserted into or removed from the radiant housing 18 with a tool 80.

[0211] In an embodiment, the diameters 94, 95 of the first and second circles 74, 75 are smaller than an inner diameter 96 of the radiant housing 18 by a margin 97 of at least 1mm, preferably at least 5mm, more preferably at least 10mm, even more preferably at least 60mm. The inner diameter 96 of the radiant housing 18 is the diameter of a circle inscribed in the radiant housing 18. An advantage of this embodiment is to allow the insertion of a tool 80 between the electrical heating insert 60 and an inner surface 58 of the radiant housing 18. More precisely the tool 80 may be inserted in a gap 56 between the heat stopper 66 and the inner surface 58. The tool 80 may be used for manipulating the electrical heating insert 60, for instance for inserting the electrical heating insert 60 into the radiant housing 18, or for removing the electrical heating insert 60 from the radiant housing 18. The diameters 94, 95, and 96 are illustrated in Fig. 17, as well as the gap 56 and the inner surface 58 of the radiant housing 18. The margin 97 is also illustrated in Fig. 17, where it is shown that the margin 97 measures the amplitude of the gap 56 as the difference between the inner diameter 96 of the radiant housing 18 and the diameters 94, 95 of the first and second circles 74, 75. The first and second circles 74, 75 are represented by way of example in Fig. 18.

[0212] In an embodiment, the electrical heating insert 60 further comprises a heat barrier 98 configured for covering a gap 56 between the heat stopper 66 and an inner surface 58 of the radiant housing 18. The heat barrier 98 is not part of the heat stopper 66, but rather comes in addition to the heat stopper 66 for preventing the heat emitted by the electrical heating conductor 62 comprised in the electrical heating insert 60 from escaping the interior volume 29 of the radiant housing 18. The heat barrier 98 may be made of a refractory material, such as a ceramic material, or compressed refractory fibers, or a fibrous material such as glass wool or rock wool. Generally, the heat barrier 98 may be made of a different material than the support element 64 or the heat stopper 66. An advantage of the heat barrier 98 is to block at least part of the heat that is emitted by the electrical heating conductor 62 and that may pass through the gap 56 between the heat stopper 66 and the inner surface 58 of the radiant housing 18. The heat barrier 98 preferably covers the gap 56 by being arranged either in the gap 56 or in front of the gap 56.

[0213] Fig. 19 schematically represents by way of example a transversal cut of an electrical heating device 92 with a heat barrier 98. The electrical heating device 92 comprises an electrical heating insert 60. The electrical heating insert 60 comprises a heat stopper 66 and a heat barrier 98 as represented in Fig. 19. The heat stopper 66 is traversed by a support bar 68 and electrical terminals 70. The heat stopper 66 is supported on a wall 24 of a radiant housing 18 comprised in the electrical heating device 92. The heat barrier 98 represented in Fig. 19 is a crescent-shaped part made of refractory, i.e. heat-resistant, material. In Fig. 19, the heat barrier 98 is arranged between the heat stopper 66 and an inner surface 58 of the radiant housing 18. Alternatively, the heat barrier 98 could also be arranged in front of the heat stopper 66 such as to cover the gap 56 between the heat stopper 66 and the inner surface 58 of the radiant housing 18.

[0214] Figures 20 to 25 schematically represent by way of example a support element 64 of an electrical heating insert 60 according to different embodiments. Each one of said Figures represents a transversal cut of a support element 64 supporting an electrical heating conductor 62. Each one of said Figures further represents a first circle 74 circumscribed to said support element 64. The support element 64 represented in each one of said Figures may be rotated around a second main axis 61 of the electrical heating insert 60 such that the insert 60 may operate in a plurality of angular positions relative to the second main axis 61.

[0215] In Fig. 20, the support element 64 has an hexagonal cross-section. In Fig. 21, the support element 64 has an octagonal cross-section. In Fig. 22, the support element 64 has a circular cross-section. In Fig. 23, the support element 64 has a substantially circular cross-section. In addition, the support element 64 represented in Fig. 23 comprises a groove 76 for receiving a measuring device 51 , such as a thermocouple. In Fig. 24 and in Fig. 25, the support element 64 comprises a plurality of grooves 761 , 762, 763. In Fig. 24, the electrical heating conductor 62 is supported inside the support element 64. In Fig. 25, the electrical heating conductor 62 is supported outside the support element 64.Rotation of an electrical heating insert relative to a radiant housing

[0216] A radiant housing 18 comprised in an electrical heating device 92 for an industrial furnace 10 may undergo deformation, in particular sagging or bending, over its service life due to creep and / or fatigue, as described hereinabove. To mitigate such deformation and extend the service life of the radiant housing 18, said housing 18 may be periodically rotated around a first main axis 23 during a maintenance operation of the electrical heating device 92. This rotation helps compensate for, or counteract, the sagging or bending of the radiant housing 18 caused by creep and / or fatigue. An electrical heating insert 60 comprised in the electrical heating device 92 and supported in the radiant housing 18 may be rotated by an angle of rotation around a second main axis 61 in said maintenance operation. The insert 60 may be configured for operating in a plurality of angular positions around the second main axis 61 such that said insert 60 may undergo a rotation around the second main axis 61 with a reduced risk of damage for the insert 60 or a part thereof.

[0217] The maintenance operation of the electrical heating device 92 may comprise the following steps:(a) providing an electrical heating device 92 comprising a radiant housing 18 extending along a first main axis 23 and an electrical heating insert 60 extending along a second main axis 61, wherein the electrical heating insert 60 is arranged in the radiant housing 18 and lies on a wall 24 of the radiant housing 18, and wherein the electrical heating insert 60 is configured for operating in a plurality of angular positions relative to the second main axis 61 ;(b) rotating the electrical heating insert 60 relative to the radiant housing 18 by an angle of rotation around the second main axis 61, such as to position the electrical heating insert 60 in a new angular position relative to the radiant housing 18;(c) operating the electrical heating insert 60 in said new angular position.

[0218] Said steps are executed preferably, but not necessarily, in the indicated order, i.e. the alphabetical order.

[0219] The first main axis 23 of the radiant housing 18 and the second main axis 61 of the electrical heating insert 60 are substantially parallel, or even merged.

[0220] An electrical heating insert 60 may be rotated around the second main axis 61 when the insert 60 is equipped with a measuring device 51 such as a thermocouple, in particular when the measuring device 51 is inserted in the interior volume 78 of the electrical heating insert 60 through a first opening in the heat stopper 66 and a second opening in the at least one support element 64.

[0221] An advantage of rotating the electrical heating insert 60 relative to the radiant housing 18 is to facilitate a maintenance operation of the radiant housing 18, for example a maintenance operation in which the radiant housing is rotated around the first main axis 23 in order to compensate for a deformation of the radiant housing 18, in particular in order to compensate for a sagging or bending of the radiant housing due to creep and / or fatigue. More precisely, the maintenance operation is facilitated by avoiding additional steps of insertion or removal of the electrical heating insert 60 into or from the radiant housing 18.

[0222] The angle of rotation of the electrical heating insert 60 around the second main axis 61 may be comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°. Even more preferably, the angle of rotation may be substantially equal to 180°.

[0223] Preferably, the step (b) of rotating the electrical heating insert 60 comprises the following step:(b’) rotating the radiant housing 18 around the first main axis 23.

[0224] An advantage of rotating the electrical heating insert 60 by rotating the radiant housing 18 in which the insert 60 is arranged is to further facilitate the maintenance operation of the radiant housing 18.

[0225] Rotating the electrical heating insert 60 by rotating the radiant housing 18 is particularly advantageous in the case of a cylindrical radiant housing 18 such as a radiant tube. In such a case, the insert 60 may roll inside the housing 18 during the rotation of the housing 18, thereby causing a rotation of the insert 60.

[0226] However, other ways of rotating the electrical heating insert 60 relative to the radiant housing 18 are generally possible, for instance by removing the insert 60 from the housing 18 before the rotation of the housing 18, and re-inserting the insert 60 into the housing 18 after the rotation of the housing 18. Such an insertion or removal of the insert 60 is preferably performed with a tool 80. In particular, an insertion or removal of the insert 60 with a tool 80 may allow to manipulate the insert 60 in the case of a deformed housing 18, such as a bent housing 18 due to creep and / or fatigue. Indeed, in such a case, rotating the housing 18 with the insert 60 inside may not allow the insert 60 to rotate freely within the housing 18, andmay even cause damage to the insert 60 or a part thereof. Therefore, in the case of a deformed housing 18, the insert 60 is preferably removed from the housing 18 prior to the rotation of the housing 18.

[0227] In an embodiment, the step (b), i.e. rotating the electrical heating insert 60, of the maintenance operation of the electrical heating device 92 is performed once a certain amount of deformation of the radiant housing 18 has been reached. This allows said maintenance operation 92 to be performed only when needed, thereby reducing a cost of said maintenance operation.

[0228] In an embodiment, the rotation of the electrical heating insert 60 around the second main axis 61 in the step (b) of the maintenance operation of the electrical heating device 92 is performed so as to limit the deformation of the electrical heating insert 60 or a part thereof (e.g. an electrical heating conductor 62) relative to the at least one support element 64 and measured in a plane perpendicular to the second main axis 61 to a difference between an inner diameter 96 of the radiant housing 18 and a diameter 94 of a first circle 74 circumscribed to the at least one support element 64. This may be achieved by limiting the torsion of the insert 60 around the second main axis 61 , for instance. Generally, the deformation of the insert 60 may be larger than said difference. Limiting or reducing the deformation of the insert 60 or a part thereof during said maintenance operation allows a risk of damage of the insert 60 or a part thereof to be limited or reduced. Therefore, this allows the service life of the insert 60 and of the electrical heating device 92 to be extended.

[0229] In summary, the invention relates to a heating assembly 16 for an industrial furnace 10 and comprising a radiant housing 18 extending along a first main axis 23 in the industrial furnace 10 and supported by a first support 26 and a second support 27, and an electrical heating insert 60 extending along a second main axis 61 and arranged in the radiant housing 18, wherein the radiant housing 18 is configured for operating in a plurality of angular positions relative to the first main axis 23, and wherein the first support 26 and the second support 27 comprise supporting means 30 for allowing a rotation of the radiant housing 18 around the first main axis 23 during a maintenance operation in order to compensate for previous deformation of the radiant housing 18 and therefore extend the service life of the radiant housing 18.

[0230] Although the present invention has been described herein with respect to particular embodiments, it will readily be appreciated by a person skilled in the art that the present disclosure is not limited by what has been particularly shown and / or described and that alternatives, modified embodiments, or combined embodiments could be developed in thelight of the overall teaching of this disclosure. Several objects have been described herein, which may be considered independently or be combined. These objects relate to, but are not limited to, the following elements: the heating assembly 16, the set 17, the radiant housing 18, the support 27, the electrical heating insert 60, and the electrical heating device 92. The scope of the invention is more generally defined by the following appended claims.

Claims

- 62 -Claims1. Heating assembly (16) for an industrial furnace (10) and comprising: a first furnace wall portion (21) and a second furnace wall portion (22) facing each other, said wall portions (21 , 22) delimiting an inner volume (20) of the heating assembly (16); a radiant housing (18) for heating the inner volume (20), the radiant housing (18) extending along a first main axis (23) and comprising a first end (181) and a second end (182), the first main axis (23) extending between said wall portions (21, 22); an electrical heating insert (60) extending along a second main axis (61) and arranged in the radiant housing (18); a first support (26) for supporting the first end (181) of the radiant housing (18), said first support (26) being arranged on one of the furnace wall portions (21, 22); a second support (27) for supporting the second end (182) of the radiant housing (18), said second support (27) being arranged on one of the furnace wall portions (21 , 22); wherein the radiant housing (18) is configured for operating in a plurality of angular positions relative to the first main axis (23), and wherein the first support (26) and the second support (27) comprise supporting means (30) for allowing a rotation of the radiant housing (18) around the first main axis (23) during maintenance, with said radiant housing (18) resting on said first and second supports (26, 27).

2. Heating assembly (16) according to the preceding claim, wherein at least one of said first and second supports (26, 27) further comprise blocking means for preventing rotation of the radiant housing (18) around the first main axis (23) during operation.

3. Heating assembly (16) according to any one of the preceding claims, wherein said supporting means (30) are further configured for allowing a translation of the radiant housing (18) along the first main axis (23).

4. Heating assembly (16) according to the preceding claim, wherein the first support (26) further comprises a stop (50) for limiting the translation of the radiant housing (18) along the first main axis (23) during maintenance.

5. Heating assembly (16) according to any one of the preceding claims, wherein the radiant housing (18) is configured to be rotated around the first main axis (23) by an angle comprised- 63 - between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°, even more preferably substantially equal to 180°.

6. Heating assembly (16) according to any one of the preceding claims and further comprising a handle mechanically coupled to the radiant housing (18) at least during maintenance for facilitating the rotation of the radiant housing (18) around the first main axis (23).

7. Heating assembly (16) according to any one of the preceding claims, wherein the first support (26) is configured for allowing a local rotation of the first end (181) of the radiant housing (18) around a first transverse axis (36) transverse to the first main axis (23).

8. Heating assembly (16) according to any one of the preceding claims, wherein the first support (26) is arranged outside the inner volume (20).

9. Heating assembly (16) according to any one of the preceding claims, wherein the first support (26) further comprises compensating means (34) for allowing a deformed radiant housing (18) to be mechanically coupled to one of the furnace wall portions (21 , 22).

10. Heating assembly (16) according to the preceding claim, wherein said compensating means (34) of the first support (26) comprise a sleeve (35) mechanically coupled to the first end (181) of the radiant housing (18) and to the furnace wall portion (21 , 22) on which the first support (26) is arranged.

11. Heating assembly (16) according to the preceding claim, wherein the first end (181) of the radiant housing (18) and the sleeve (35) each comprise a flange (40, 42), both flanges (40, 42) being configured to be bolted together for preventing rotation of the radiant housing (18) around the first main axis (23) during operation.

12. Heating assembly (16) according to the preceding claim, wherein the first end (181) of the radiant housing (18) is gas-tightly sealed against the furnace wall portion (21 , 22) on which the first support (26) is arranged during operation.- 64 -13. Heating assembly (16) according to the preceding claim, wherein the heating assembly (16) further comprises a gasket (44), and wherein the gas-tight sealing between the first end (181) of the radiant housing (18) and the furnace wall portion (21 , 22) on which the first support(26) is arranged is ensured by said gasket (44) being arranged between the flange (40) of the first end (181) of the radiant housing (18) and the flange (42) of the sleeve (35).

14. Heating assembly (16) according to any one of the preceding claims, wherein the second support (27) is configured for allowing a local rotation of the second end (182) of the radiant housing (18) around a second transverse axis (38) transverse to the first main axis (23).

15. Heating assembly (16) according to any one of the preceding claims, wherein the second support (27) is arranged inside the inner volume (20) and is mechanically coupled to one of the furnace wall portions (21 , 22) through a socket (46).

16. Heating assembly (16) according to the preceding claim, wherein the second support(27) is configured for supporting a plurality of radiant housings (18) from said socket (46), wherein each radiant housing (18) in the plurality extends along a respective main axis (23), and wherein each radiant housing (18) in the plurality is rotatable individually around its respective main axis (23).

17. Heating assembly (16) according to the preceding claim, wherein the plurality of radiant housings (18) are arranged in the inner volume (20) along an axis (28) transverse to their respective main axes (23).

18. Heating assembly (16) according to any one of the preceding claims, wherein the radiant housing (18) is movable along the first main axis (23) in sliding friction relative to the second support (27).

19. Heating assembly (16) according to the preceding claim, wherein the second support (27) further comprises a pad (48) for preventing sticking of the second end (182) of the radiant housing (18) to the second support (27).

20. Heating assembly (16) according to any one of the preceding claims, wherein the electrical heating insert (60) comprises an electrical heating conductor (62) and at least one- 65 - support element (64) for supporting the electrical heating conductor (62), the at least one support element (64) being made of a heat-resistant and electrically insulating material, the electrical heating conductor (62) being electrically insulated from the radiant housing (18).

21. Heating assembly (16) according to any one of the preceding claims, wherein the electrical heating insert (60) is configured for operating in a plurality of angular positions relative to the second main axis (61).

22. Heating assembly (16) according to any one of the preceding claims, wherein an envelope (72) of the electrical heating insert (60) is substantially cylindrical in shape and has a uniform cross-section along the second main axis (61).

23. Heating assembly (16) according to any one of the preceding claims, wherein the electrical heating insert (60) is configured for being inserted into or removed from the radiant housing (18).

24. Heating assembly (16) according to any one of the preceding claims, wherein the first end (181) of the radiant housing (18) is configured for allowing the insertion of a measuring device (51) through said first end (181) for measuring a physical property of the inner volume (20).

25. Heating assembly (16) according to the preceding claim, wherein the measuring device (51) is a thermocouple for measuring a temperature of the inner volume (20).

26. Heating assembly (16) according to any one of the preceding claims, wherein the first end (181) of the radiant housing (18) is configured for allowing the insertion of a measuring device (51) through said first end (181) for measuring a physical property of an interior volume (29) of the radiant housing (18).

27. Heating assembly (16) according to the preceding claim, wherein the measuring device (51) is a thermocouple for measuring a temperature of the interior volume (29).

28. Heating assembly (16) according to any one of the preceding claims, wherein the radiant housing (18) is substantially cylindrical in shape.- 66 -29. Heating assembly (16) according to any one of the preceding claims, wherein the first end (181) of the radiant housing (18) is an open end (183).

30. Heating assembly (16) according to the preceding claim, wherein said open end (183) is configured for allowing the insertion of the electrical heating insert (60) into the radiant housing (18).

31. Heating assembly (16) according to any one of the preceding claims, wherein the radiant housing (18) is made of steel.

32. Heating assembly (16) according to any one of the preceding claims, wherein a surface of the radiant housing (18) is not smooth.

33. Furnace (10) comprising a heating assembly (16) according to any one of the preceding claims.

34. Use of a heating assembly (16) according to any one of claims 1 to 32 for a heat treatment of a steel product.

35. Maintenance operation for a heating assembly (16) according to any one of claims 1 to 32 and comprising the following step:(d) rotating the radiant housing (18) by an angle of rotation around the first main axis (23) while the radiant housing (18) is supported by the first support (26) and the second support (27).

36. Maintenance operation according to the preceding claim, wherein the angle of rotation is comprised between 15° and 345°, preferably between 90° and 270°, more preferably between 135° and 225°, even more preferably substantially equal to 180°.

37. Maintenance operation according to any one of the two preceding claims and further comprising the following steps:(c) translating the radiant housing (18) along the first main axis (23) for separating the first end (181) of the radiant housing (18) from the blocking means preventing rotation of theradiant housing (18) around the first main axis (23), while the radiant housing (18) is supported by the first support (26) and the second support (27);(e) translating the radiant housing (18) along the first main axis (23) for joining the first end (181) of the radiant housing (18) with the blocking means preventing rotation of the radiant housing (18) around the first main axis (23), while the radiant housing (18) is supported by the first support (26) and the second support (27).

38. Maintenance operation according to any one of the three preceding claims and further comprising the following steps:(b) releasing the blocking means preventing rotation of the radiant housing (18) around the first main axis (23);(f) reinstalling the blocking means for preventing rotation of the radiant housing (18) around the first main axis (23).

39. Maintenance operation according to any one of the four preceding claims and further comprising the following steps:(a) removing the electrical heating insert (60) from the radiant housing (18) before the rotation of the radiant housing (18) performed in step (d);(g) inserting the electrical heating insert (60) into the radiant housing (18) after the rotation of the radiant housing (18) performed in step (d).

40. Maintenance operation according to any one of the five preceding claims characterized in that said maintenance operation is performed once a certain amount of deformation of the radiant housing (18) has been reached.

41. Maintenance operation according to the preceding claim, wherein the amount of deformation of the radiant housing (18) is measured by a local rotation of the first end (181) of the radiant housing (18) around a first transverse axis (36) transverse to the first main axis (23).

Images