Element for connecting two arms of a immersion fusion electrode holder, associated electrode holder, and furnace incorporating such a holder

Abstract

Element for connecting two arms of a immersion fusion electrode holder, associated electrode holder, and furnace comprising such a holder. The invention relates to an element (83) for connecting a first horizontal arm (81) and a second vertical arm (82) of a holder (8) for an immersion fusion electrode from the surface of a molten bath, each arm comprising a current supply system and a fluidic cooling device, the electrode (1) being intended to be fixed to one end of the second arm. The connecting element comprises a body (83_1) surrounded by a casing (83_2) made of electrically insulating material, said body being configured to connect the respective current supply systems of the first and second arms as well as to connect the respective cooling devices of the first and second arms. Figure for the abstract: Fig. 2

Description

Title of the invention: Element for connecting two arms of a immersion fusion electrode holder, associated electrode holder, and furnace comprising such a holder Previous technique

[0001] The present invention belongs to the field of electrical glass melting by means of techniques in which energy is dissipated by Joule effect in the molten mass from immersion electrodes.

[0002] The invention relates more particularly to the configuration of various parts involved in the construction of a support for a fusion electrode immersed from the surface of a molten bath, as well as to said electrode support itself. The invention also relates to a fusion furnace comprising one or more such electrode supports.

[0003] Conventionally, a furnace for melting a vitrifiable material, particularly used in the production of flat glass, hollow glass, or insulation fibers, and also called a glass furnace, comprises a chamber surmounted by a vault. The chamber, made of a refractory material, consists of a floor and side walls, and forms the area in which the vitrifiable material is melted to create a molten pool. The vault, also made of a refractory material, is suspended from a metal frame spanning the furnace, thus defining an enclosed space. Such a configuration is described, for example, in document WO 9509518.

[0004] In order to bring the vitrifiable material to a melting temperature, the furnace includes heating means in the form of immersion melting electrodes, i.e. melting electrodes immersed from the surface of the melting bath and through which electrical energy is dissipated by Joule effect in the molten mass.

[0005] More specifically, each immersion electrode is fixed to one end of an arm belonging to a support for which a passage is provided through a side wall of the tank. An opposite end of said arm is fixed to an electrical power supply unit.

[0006] The electrode support arm typically includes a metal portion adapted to carry the current from the power supply unit to the electrode and within which a primary cooling device of the "water-jacket" type is provided (i.e., a network of pipes adapted for the circulation of a cooling fluid). Optionally, an auxiliary cooling device, also of the water-jacket type, may be provided around a horizontal portion (i.e., parallel to the surface of the weld pool) of said metal portion.

[0007] In one variant, and as described in the aforementioned WO 9509518 document, the electrode holder arm may optionally include, in addition to the metal portion, another current-conducting element that is also equipped with a water jacket-type cooling device. This other element constitutes a vertical extension, one end of which is screwed onto the end of the metal portion opposite the power supply housing. The electrode is attached to the other end of this extension. This design allows for easy disassembly of the extension / electrode assembly because the screw connection is never immersed in the weld pool.

[0008] Regardless of whether or not such an extension is present, the metallic portion of the arm systematically consists of a horizontal section and a vertical (or substantially vertical) section joined by an angled section. The horizontal section is the longest, as it determines the electrode's position in the weld pool. Its length is constrained, in particular, by the size of the tank and can, for example, reach a value of approximately 4000 mm.

[0009] The presence of said bent section is problematic insofar as it constitutes a weakness in the arm, and therefore, a fortiori, in the electrode support as a whole. Indeed, on the one hand, bending the metal of the profile creates stresses that mechanically weaken this part. On the other hand, the operating efficiency of the main cooling device depends in particular on maintaining constant gaps between the pipes that compose it. However, maintaining such constant gaps is particularly difficult to guarantee when the metal portion must be bent in this way.

[0010] Moreover, this angled section is not protected from the vitrifiable materials introduced into the tank from above. Consequently, a fraction of said vitrifiable materials can be deposited on the angled section and then melt due to the heat within the furnace, which is detrimental to maintaining the integrity of the electrode support.

[0011] Finally, assuming the presence of an auxiliary cooling device composed of metal pipes, the presence of such a deposit of molten vitrifiable materials on the bent section can contribute to the formation of electric arcs between the bent section (which helps to conduct the current to the electrode) and said auxiliary cooling device. Such electric arcs are not only detrimental to the proper functioning of the furnace but also represent a safety risk for operators. Description of the invention

[0012] The present invention aims to remedy all or part of the disadvantages of the prior art, in particular those set out above, by proposing a solution which allows for a mechanically robust electrode support, capable of guaranteeing the maintenance of constant gaps between the pipes of a cooling device which equips it and without risk to the operators.

[0013] To this end, and according to a first aspect, the invention relates to an element for the connection between a first horizontal arm and a second vertical arm of a support for a fusion electrode immersed from the surface of a fusion bath, each arm comprising a current supply system as well as a fluidic cooling device, the electrode being intended to be fixed to one end of the second arm, the connecting element comprising a body surrounded by a sheath made of electrically insulating material, said body being configured to connect the respective current supply systems of the first and second arms as well as to connect the respective cooling devices of the first and second arms.

[0014] The notion of horizontality (respectively of verticality) refers to any direction parallel (respectively orthogonal) to the surface of the melting bath.

[0015] The connecting element according to the invention thus allows for both electrical and fluid connection between the first arm, which is purely horizontal, and the second arm, which is purely vertical. In other words, the connecting element advantageously prevents at least one of the arms from having a bent section. In this way, it is particularly easy to maintain constant spacing between the cooling channels of the respective cooling devices of the first and second arms.

[0016] The presence of the enclosure made of electrical insulating material advantageously minimizes electrical risks, particularly in terms of the appearance of electric arcs and protection from operators.

[0017] Moreover, it should be noted that the connecting element can, for example, be external to the first and second arms, or be integrated into the first arm as detailed in later embodiments.

[0018] In particular embodiments, the connecting element may further comprise one or more of the following characteristics, taken individually or in all technically possible combinations.

[0019] In embodiments, the current supply system and the fluidic cooling device of each arm can form a single system, of the type of a current-conducting cooling system.

[0020] In particular embodiments, the fluidic cooling device of each arm is of the “water-jacket” type.

[0021] In particular embodiments, the electrically insulating material of the body's casing may have a minimum dielectric strength of 2.5 kV / mm and / or be resistant to temperatures of at least 400°C. It may, for example, be a mica- or glass-based composite material, such as glass-epoxy, glass-polyester, or glass-vinylester composite materials, preferably made of woven fiber (particularly roving, i.e., with the fibers interlaced at 90°) to provide excellent mechanical strength. More specific examples of electrically insulating materials include the products marketed by ICM INDUSTRIE under the names R330 or Ciment 700 / H91, or the Dotherm 700 (registered trademark) or Doglas 280 (registered trademark) products from DO THERM.

[0022] Where the connecting element is external to the first and second arms, the electrically insulating material of the casing can advantageously be a material capable of withstanding very high temperatures, such as a non-conductive refractory material. This significantly reduces the risk of damage to the connecting element from vitrifiable materials introduced into the furnace from above, which could fall onto the connecting element and potentially melt.

[0023] More generally, these provisions relating to the electrical insulating material of the body casing can be applied to any other electrically insulating material used in the present invention. Preferably, the electrically insulating material has a dielectric strength of at least 2.5 kV / mm, preferably at least 5 kV / mm, and more preferably at least 10 kV / mm.

[0024] In particular embodiments, the cooling device for each arm comprises a first conduit and a second conduit, the second arm having a so-called "lower" end to which the electrode is intended to be attached and an opposite so-called "upper" end, the body comprising a fluidic circuit comprising first and second channels configured such that: - the first channel has opposite first and second ends, the first end opening at the level of the casing and configured to be fluidically connected to the first conduit of the first arm, the second end being located inside the body and configured to be fluidly connected to the second conduit of the second arm, - the second channel has opposite first and second ends opening at the level of the casing,The first end is configured to accommodate the upper end of the second arm and to be fluidly connected to the first conduit of the second arm, the second end being configured to be fluidly connected to the second conduit of the first arm.

[0025] It should be noted that the expression "connect fluidly", when used to describe a connection between two elements via an interface, for example between a channel and a conduit via an end, refers to a connection through which a fluid flowing in one of these elements is able, by reason of its flow and the passage of said interface, to flow in the other element.

[0026] In particular embodiments, the second channel includes, at the first end, means adapted for connecting the upper end of the second arm by screwing, for example a tapping.

[0027] In particular embodiments, the body is made of electrically conductive material.

[0028] Preferably, the electrically conductive material has an electrical conductivity of at least 3x107 Siemens / m, more preferably of at least 3.5x107 Siemens / m, even more preferably of at least 4x107 Siemens / m, even more preferably of at least 5x107 Siemens / m.

[0029] In particular embodiments, the electrically conductive material of the body is copper, aluminum, or silver. These metals have the advantage of very high conductivity. The electrical material of the body may also be an alloy using one or more of these metals. Examples of alloys include copper-aluminum, brass, or a silver alloy.

[0030] More generally, these provisions relating to the electrically conductive material of the body can be applied to any other electrically conductive material used in the present invention.

[0031] The connecting element can be of any shape. In particular embodiments, said connecting element is parallelepiped in shape.

[0032] According to a second aspect, the invention relates to an arm, referred to as the "first arm", for a support for a fusion electrode immersed from the surface of a fusion bath and comprising a second vertical arm having a "lower" end to which the electrode is intended to be fixed and an opposite "upper" end, the first arm being intended to extend horizontally when integrated into the support and comprising: - a profile comprising a first end configured to be fixed to a power supply box and a second opposite end, said second end further comprising an opening configured to accommodate the upper end of the second arm, - a power supply system and a fluidic cooling device, referred to as the "main cooling device", arranged inside the profile, - a connecting element according to the invention, said connecting element being arranged inside the profile at its second end.

[0033] In particular embodiments, the first arm may further comprise one or more of the following characteristics, taken individually or in all technically possible combinations.

[0034] In particular embodiments, the profile is a metal profile, preferably of parallelepiped shape.

[0035] In particular embodiments, the main cooling device comprises a first conduit and a second conduit, said first conduit and / or said second conduit being made of electrically conductive material so as to form the current supply system.

[0036] In particular embodiments, only one of the first and second conduits of the main cooling device is made of an electrically conductive material, for example the first conduit, the other conduit, for example the second conduit, being made of an electrically insulating material, for example polyethylene.

[0037] In particular embodiments, the first conduit of the main cooling device is surrounded by an electrically insulating material, said arm further comprising another fluidic cooling device, called "auxiliary cooling device", arranged inside the profile, around the electrically insulating material surrounding the main cooling device and around the connecting element.

[0038] In particular embodiments, the profile extends over a distance greater than 2000 mm, preferably greater than 3500 mm, more preferably greater than 4000 mm, and even more preferably greater than 5000 mm, for example up to 6000 mm. This offers an advantage for good heat transfer to the center of the melting vessel and for good melting of the raw materials, including in larger furnaces.

[0039] According to a third aspect, the invention also relates to a kit comprising the following elements: - a first horizontal arm and a second vertical arm, each arm comprising a current supply system and a fluidic cooling device, - a connection element according to the invention, said elements being intended to be assembled together to form a support for a fusion electrode immersed from the surface of a fusion bath, the electrode being intended to be fixed to one end of the second arm.

[0040] In particular embodiments of this kit, the first arm conforms to the invention.

[0041] According to a fourth aspect, the invention relates to a fusion electrode support immersed from the surface of a fusion bath comprising a first horizontal arm and a second vertical arm, each arm comprising a current supply system as well as a fluidic cooling device, the electrode being intended to be fixed to one end of the second arm, said support further comprising a connection element according to the invention.

[0042] In particular embodiments of this support, the first arm conforms to the invention.

[0043] According to a fifth aspect, the invention relates to a furnace comprising one or more supports for fusion electrodes according to the invention. Brief description of the drawings

[0044] Other features and advantages of the present invention will become apparent from the description below, with reference to the accompanying drawings which illustrate an example of an embodiment without being limiting in any way. In the figures:

[0045] Fig. 1 schematically represents, in its environment, part of a melting furnace, according to a particular embodiment of the invention;

[0046] Fig. 2 schematically represents a three-quarter view of an electrode support integrated into the furnace of Fig. 1;

[0047] Fig. 3 represents a cross-sectional view of the electrode support of Fig. 2, along a longitudinal section plane;

[0048] Fig. 4 schematically represents a particular example of the realization of cooling devices integrated into a first horizontal arm of the electrode support of Fig. 3, according to a section plane BB indicated on Fig. 3;

[0049] Fig. 5 schematically represents a particular example of the realization of the cooling devices of Fig. 4, according to another CC section plane shown on Fig. 3;

[0050] Fig. 6 is an enlarged view of an area of ​​the electrode support of Fig. 3, said area being located at one end of the first arm connected to a second vertical arm of said electrode support;

[0051] Fig. 7 is a top view of the electrode support area considered in Fig. 6.

[0052] Description of embodiments

[0053] Fig. 1 schematically represents, in its environment, part of a melting furnace, according to a particular embodiment of the invention.

[0054] Conventionally, and as illustrated by [Fig.1], the furnace comprises a tank made of refractory material to contain a melting bath 7.

[0055] In the present description, the notion of horizontality (respectively of verticality) refers to any direction parallel (respectively orthogonal) to the surface of the melting bath 7.

[0056] The furnace comprises a hearth 2 and side walls 3. Above the furnace, a refractory vault 4 is suspended from a metal frame 5 (partially shown) spanning the furnace. Movable refractory walls 6 are provided which, when in the lowered position, i.e., resting on the side walls 3, allow the molten bath 7 to be partially isolated from the surrounding atmosphere. This lowered position of the walls 6 is adopted when the furnace is in standby mode and it is no longer necessary to supply it with vitrifiable raw materials. This prevents excessive heat loss and the risk of damaging all the surrounding equipment.

[0057] Openings in the walls 3 are provided for the passage of supports 8. Each of said supports 8 is configured to support an electrode 1, for example made of molybdenum, immersed on the surface of the melting bath 7 under a layer 9 of vitrifiable materials to be melted. This layer 9, which covers the melting bath 7 in normal operating mode, thermally insulates the basin and prevents heat loss.

[0058] For reasons of readability, only one electrode 1, and therefore a fortiori only one support 8, are shown in [Fig. 1]. These provisions are not, however, limiting to the invention, and nothing precludes considering a plurality of immersion electrodes, and therefore a fortiori a plurality of supports 8.

[0059] As shown in [Fig.1], the support 8 is fixed, at an end opposite to that to which the electrode 1 is fixed, to a power supply box 10. In a known manner, this power supply box 10 includes a power supply collar 10_1, made of an electrically conductive material to put the support 8, and therefore a fortiori the electrode 1, at the desired voltage.

[0060] There is no limitation on the current that can supply the electrode 1, which can therefore be single-phase, two-phase, or three-phase. The housing 10 also includes an insulating box 10_2 (particularly for safety reasons) inside which the power supply collar 10_1 is arranged and which constitutes the outer casing of the housing 10.

[0061] The invention is not limited by the nature of the electrically conductive material of the power supply collar 10. Preferably, the electrically conductive material has an electrical conductivity of at least 3 x 10⁷ Siemens / m, more preferably of at least 3.5 x 10⁷ Siemens / m, even more preferably of at least 4 x 10⁷ Siemens / m, and even more preferably of at least 5 x 10⁷ Siemens / m. Said electrically conductive material may, for example, be copper or aluminum. or silver. The electrical material of the body can also be an alloy using one or more of these metals (examples: cupro-aluminum, brass, silver alloy).

[0062] More generally, these technical considerations relating to the nature of the electrically conductive material of the power supply collar 10 apply to any other electrically conductive material mentioned later in the description.

[0063] In its general principle, the support 8 according to the invention results from the assembly of a plurality of elements. It follows that the support 8 can be supplied in the form of a kit intended to be assembled according to a suitable assembly method.

[0064] Said support elements 8 comprise a first horizontal arm 81 and a second vertical arm 82, the electrode 1 being fixed to one end of said second arm 82.

[0065] Each arm 81, 82 comprises a current supply system and a fluidic cooling device. For the purposes of this description, the fluidic cooling device of each arm 81, 82 is considered, without limitation, to be a closed-loop "water-jacket" type system for circulating a coolant, for example, demineralized water. However, the invention is not limited by this type of fluidic cooling device. In particular, nothing precludes the use of a coolant other than a liquid, such as a gas (e.g., air). Generally, any technique known to those skilled in the art for circulating a coolant may be considered.

[0066] In addition to the said first and second arms 81, 82, the support 8 also includes an element 83 for making a connection between the arms 81, 82, also referred to more simply as "connecting element 83" below.

[0067] This configuration therefore differs from the prior art in that the first arm 81 is purely horizontal and the second arm 82 is purely vertical, the connection between them being ensured by the connecting element 83. In other words, neither of said arms 81, 82 has a bent section. In this way, it is particularly simple to maintain constant spacing between the conduits of the respective cooling devices of the first and second arms 81, 82.

[0068] Moreover, the connecting element 83 comprises a body 83_1 surrounded by an enclosure 83_2 made of electrically insulating material. The presence of such an enclosure 83_2 advantageously minimizes electrical risks, particularly in terms of the occurrence of electric arcs and protection for operators.

[0069] For example, the electrically insulating material may have a minimum dielectric strength of 2.5 kV / mm and / or be resistant to temperatures of at least 400°C. It may, for example, be a mica- or glass-based composite material, by Examples of composite materials include glass-epoxy, glass-polyester, or glass-vinylester, preferably woven fiber (particularly roving type, meaning the fibers are interlaced at 90°) to provide excellent mechanical strength. More specific examples of electrical insulating materials include products marketed by ICM INDUSTRIE under the names R330 or Ciment 700 / H91, as well as Dotherm 700 (registered trademark) and Doglas 280 (registered trademark) from DO THERM.

[0070] More generally, these technical considerations relating to the nature of the electrical insulating material of the body 83_1 apply to any other electrical insulating material mentioned later in the description.

[0071] Apart from the fact that the body 83_1 allows a mechanical connection (linkage) to be made between the first and second arms 81, 82, it is also configured to connect: - the respective current supply systems of said first and second arms 81, 82, and - the respective cooling devices of the first and second arms 81, 82.

[0072] It should be noted that [Fig.1] only provides a general and simplified schematic representation of the support 8 of electrode 1. Therefore, detailed embodiments of said support 8 will now be described in relation to other figures.

[0073] Fig. 2 schematically represents a three-quarter view of support 8.

[0074] Figure 3 shows a cross-sectional view of the support 8, along a cutting plane longitudinal (i.e. a cutting plane parallel to the average plane in which the support 8 extends).

[0075] As illustrated in [Fig. 3], the second arm 82 has a lower end 82_1 to which the electrode 1 is intended to be attached. Any method known to those skilled in the art for attaching the electrode 1 to the lower end 82_1 of the second arm 82 may be used. Opposite this lower end 82_1, the second arm has a higher end 82_2 connected to the connecting element 83, as described in more detail later.

[0076] The first arm 81 includes a main profile 81_1 which forms the external material envelope of said first arm 81. Said main profile 81_1 includes a first end 81_2 configured to be fixed to the power supply box 10. Opposite said first end 81_2, the first arm 81 includes a second end 81_3.

[0077] In this embodiment, the main profile 81_1 is a parallelepiped-shaped metal profile. The metal used can be steel or any other possible alloy or metal.

[0078] Considering a main metallic profile 81_1 of parallelepiped shape advantageously increases the structural strength of the first arm 81, and therefore a fortiori that of the entire support 8.

[0079] Correspondingly, due to this increased strength, it is possible to consider a first arm 81 of large horizontal dimension, for example extending over a distance greater than 2000 mm, preferably greater than 3500 mm, more preferably greater than 4000 mm, even more preferably greater than 5000 mm, for example up to 6000 mm.

[0080] It is important to note, however, that having a parallelepiped-shaped metal profile and / or a first arm 81 of large horizontal dimension constitutes only one variant of the invention, and nothing excludes considering another shape of profile (for example a shape having a circular section) and / or a horizontal dimension less than 2 m.

[0081] As mentioned above, the first arm 81 includes a power supply system and a water-jacket type cooling device, hereinafter referred to as the "main cooling device". Both the power supply system and the main cooling device are arranged inside the main profile 81_1.

[0082] The main cooling device comprises a first conduit 81_4 and a second conduit 81_5 (not shown in [Fig.3]), these first and second conduits 81_4, 81_5 being associated for the circulation of the coolant (in accordance with the known principle of the “water-jacket”).

[0083] In the present embodiment, the current supply system and the main cooling device form a single system, of the type of a current-conducting cooling system. More specifically, the first conduit 81_4 is made of electrically conductive material, so as to form the current supply system for the first arm 81.

[0084] The second conduit 81_5 is made of electrically insulating material, for example polyethylene.

[0085] In addition, the first conduit 81_4 is surrounded by an electrical insulating material 81_6. This electrical insulating material 81_6 allows in particular better accessibility to the support 8 without risk of electrocution for operators who have to approach the melting bath 7.

[0086] It should be noted that while the first and second conduits 81_4, 81_5 are considered here to be made of conductive and insulating materials respectively, nothing precludes the possibility of the reverse arrangement (i.e., first conduit 81_4 made of electrically insulating material and second conduit 81_5 made of conductive material). electrical). Nothing also excludes considering that each of the said first and second conduits 81_4, 81_5 is made of electrically conductive material.

[0087] In the embodiment illustrated in [Fig. 3], the connecting element 83 is arranged inside the main profile 81_1 at its second end 81_3. In other words, the main profile 81_1 of the first arm 81 surrounds the connecting element 83 at said second end 81_3. The connecting element 83 is thus protected, in particular from vitrifiable materials introduced into the furnace from above which would otherwise be liable to be deposited on said connecting element 83 and melt there.

[0088] Furthermore, in the embodiment of [Fig. 3], the connecting element 83 is also parallelepiped in shape. Since the shape of the main profile 81_1 is of the same type, this advantageously optimizes the integration of the connecting element 83 within the profile 81_1, particularly in terms of compactness and retention.

[0089] These provisions are not, however, limiting to the invention. In general, no limitation is attached to the shape of the connecting element 83.

[0090] Insofar as the connecting element 83 is arranged inside the main profile 81_1 of the first arm, said main profile 81_1 further includes an opening 81_7 configured to accommodate the upper end 82_2 of the second arm 82. Said opening 81_7 is therefore located vertically above the melt pool 7, and, as described in more detail later, in continuity with a vertical opening made in the connecting element 83 (i.e. through the envelope 83_2 so as to penetrate into the body 83_1) and in which the upper end 82_2 of the second arm is fixed.

[0091] As illustrated by [Fig. 3] by way of no limitation, the first arm 81 comprises, in the present embodiment and in addition to the main cooling device, another "water-jacket" type cooling device, referred to as the "auxiliary cooling device". This auxiliary cooling device is arranged inside the main profile 81_1, more particularly around the electrical insulating material 81_6 surrounding the main cooling device. In this case, the electrical insulating material 81_6 also provides insulation against the coolant circulating in the auxiliary cooling device.

[0092] Figure 4 schematically represents a particular embodiment of the main and auxiliary cooling devices, according to a cross-sectional view of the first arm 81, said cross-section being made along a plane labeled BB in Figure 3. By "cross-sectional", reference is made here to a plane orthogonal to the horizontal direction of the first arm 81.

[0093] Fig. 5 schematically represents said particular example of embodiment of the main and auxiliary cooling devices, according to a cross-sectional view of the first arm 81, said section being made along the plane marked CC on Fig. 3.

[0094] As can be seen from figures 4 and 5, the first and second conduits 81_4, 81_5 of the main cooling device are arranged inside an auxiliary profile 81_8, for example made of metal or metal alloy (examples: S235 steel, AISI 310, 304 or 316 type stainless steel).

[0095] In the non-limiting example of figures 4 and 5, the auxiliary profile 81_8 has a square cross-section and is arranged centrally within the main profile 81_1. For illustrative purposes, the auxiliary profile 81_8 may have height, width, and thickness dimensions of 120x120x5 mm or 150x150x5 mm.

[0096] Of course, considering an auxiliary profile 81_8 with a square section is in no way limiting of the invention, and nothing excludes considering another shape, for example rectangular (example of dimensions in the rectangular case: 200x100x6 mm).

[0097] The views in Figures 4 and 5 differ in that, in [Fig. 4], the electrical insulating material 81_6 takes the form of a plate that fills the internal space of the auxiliary profile 81_8 in which the first and second conduits 81_4, 81_5 of the main cooling device are arranged. Such a plate is advantageous in that it provides support for said first and second conduits 81_4, 81_5 along the entire length of the first arm 81. There is no limitation on the number of insulating plates that can be used. By way of illustration, in the example in [Fig. 3], five insulating plates are used and evenly distributed along the length of the arm 81.

[0098] Furthermore, in the example of Figures 4 and 5, the first and second conduits 81_4, 81_5 are not concentric. More specifically, the first conduit 81_4 is centered with respect to the main profile 81_1 and the auxiliary profile 81_8, while the second conduit 81_5 is offset with respect to the first conduit 81_4.

[0099] Still in this example of Figures 4 and 5, the auxiliary cooling device comprises a first conduit 81_9, herein being considered, without limitation, as the main profile 81_1, and a second conduit 81_10 surrounding the first and second conduits 81_4, 81_5 of the main cooling device, as well as the electrical insulating material 81_6. Moreover, the first and second conduits 81_9, 81_10 of the auxiliary cooling device extend to the second end 81_3 of the first arm 81, and also surround the connecting element 83. In this way, said second end 81_3 is closed in the horizontal direction in which the first arm 81 extends.

[0100] According to a cross-sectional view, the first and second conduits 81_9, 81_10 of the auxiliary cooling device are both rectangular in shape, said first conduit 81_9 being located inside said second conduit 81_10.

[0101] The first conduit 81_9 has longitudinal walls in contact with longitudinal walls of the auxiliary profile 81_8. A gap exists between the lateral walls of the first conduit 81_9 and the lateral walls of the auxiliary profile. Conversely, the second conduit 81_10 has lateral walls in contact with the lateral walls of the first conduit 81_9. A gap exists between the longitudinal walls of the second conduit 81_10 and the longitudinal walls of the first conduit 81_9. These gaps allow the circulation of the coolant from the auxiliary cooling system.

[0102] It should be noted that the presence of the auxiliary cooling device is optional within the meaning of the present invention. This auxiliary cooling device makes it possible, on the one hand, to prevent overheating of the electrical insulating material 81_6, even though the latter may be chosen to withstand fairly high temperatures and is already partially cooled by the main cooling device. On the other hand, it makes it possible to obtain an external surface of the support 8 that remains relatively cool and can allow handling or at least approach by an operator even when the furnace is in pilot mode and the support 8 is heated primarily by radiation from the melting bath 7.

[0103] Figure 6 is an enlarged view of a Z zone of the support 8 of Figure 3, said Z zone being located at the second end 81_3 of the first arm 81. More specifically, it is a close-up view of the Z zone identified in Figure 3, along a longitudinal section plane (i.e., a section plane parallel to the mean plane in which the support 8 extends). Note, however, that for the sake of clarity, electrode 1 is not shown in Figure 6.

[0104] The second arm 82 forms an extension whose upper end 82_2 is fixed to the connecting element 83 by passing through the opening 81_7 made in the main profile 81_1 of the first arm 81.

[0105] In this embodiment, and by way of non-limiting example, the connection between the upper end 82_2 and the connecting element 83 is achieved by screwing the upper end 82_2 into a recess made in the connecting element 83. Such an embodiment allows for easy and quick disassembly of the second arm 82 / electrode 1 assembly because the screwing point never immerses in the molten bath 7. Electrode replacements can be frequent because they are not only necessary in case of wear but also allow for modification of the electrodes and in particular their length in order to modify the immersion level and therefore the energy input within the furnace.

[0106] As shown in [Fig. 6], the arm 82 includes a sleeve 82_3, typically made of a high-temperature resistant material, such as steel, to provide protection against vitrifiable materials introduced into the furnace from above and against the molten bath 7. Such a sleeve 82_3 also provides the second arm 82 with excellent mechanical strength and protects its current supply system. Conventionally, the electrode 1 is attached to the sleeve 82_3 by surrounding one of its lower ends.

[0107] As mentioned above, the second arm 82 also includes a current supply system and a "water-jacket" type fluidic cooling device.

[0108] The cooling device for the second arm 82 allows the cooling fluid to pass to the electrode 1 so that it is cooled. For this purpose, it comprises a first conduit 82_4 and a second conduit 82_5, these first and second conduits 82_4, 82_5 being positioned inside the sleeve 82_3 and connected for the circulation of the cooling fluid (according to the known "water-jacket" principle). More particularly, in the embodiment illustrated in [Fig. 6], the first conduit 82_4 is positioned inside the second conduit 82_5, for example concentrically.

[0109] In this embodiment, the second conduit 82_5 is made of electrically conductive material. Since the body 83_1 of the connecting element 83 is also made of electrically conductive material, this allows the first conduit 81_4 of the first arm 81 to be electrically connected to the second conduit 82_5 of the second arm 82. In this way, the second conduit 82_5, which comes into contact with the electrode 1 at the lower end 82_1, forms the current supply system for the second arm 82. It should be noted that there is nothing to preclude the possibility of the first conduit 82_4 of the second arm 82 also being made of electrically conductive material.

[0110] It should be noted that the use of conductive materials such as those mentioned above (copper, aluminum, silver or an alloy using one or more of these metals) to achieve this continuity of current delivery (i.e. via the first conduit 81_4 of the main cooling device of said first arm 81, the second conduit 82_5 of the cooling device of said second arm 82 and the body 83_1 of the connecting element 83) advantageously makes it possible to supply the electrode 1 with an electric current of an intensity greater than that permitted by prior art configurations, for example more than 4500 A. Another advantage arising from these arrangements is the possibility of using, at comparable power, fewer supports 8 to heat the vitrifiable materials.

[0111] The upper end 82_2 of the second arm can be at least partially surrounded by an electrically insulating material 82_6. In the example of [Fig. 6], said electrically insulating material 82_6 is positioned between the walls of the opening 81_7 made in the main profile 81_1 of the first arm 81 and the sleeve 82_3 of the second arm 82. This electrically insulating material 82_6 achieves, for example, continuity in terms of electrical insulation with the casing 83_2 of the connecting element 83 and the electrically insulating material 81_6 arranged around the first conduit 81_4 of the main cooling device of the first arm 81.

[0112] In order to make the connection between the main cooling device of the first arm 81 and the cooling device of the second arm 82, the body 83_1 of the connecting element 83 includes a fluidic circuit.

[0113] As illustrated by [Fig.6] by way of no limitation, said fluidic circuit comprises a first channel 83_3 and a second channel 83_4, both made in the body 83_1.

[0114] The first channel 83_3 has a first end 83_5 and a second opposite end 83_6. Said first end 83_5 opens at the casing 83_2 of the body 83_1 and is configured to be fluidly connected to the first conduit 81_4 of the main cooling device of the first arm 81.

[0115] The second end 83_6, meanwhile, is located inside the body 83_1 and configured to be fluidly connected to the second conduit 82_5 of the cooling device of the second arm 82.

[0116] More specifically, in the embodiment described here with reference to [Fig.6], the first channel 83_3 comprises two parts, namely: - a recess into which the first conduit 81_4 of the main cooling device of the first arm 81 is inserted. Said first end 83_5 is therefore one of the ends of said recess; - a bore in communication with said recess and to which belongs said second end 83_6.

[0117] The second channel 83_4 has a first end 83_7 and a second opposite end 83_8 (not shown in [Fig. 6] for readability). Said first and second ends 83_7, 83_8 both open into the casing 83_2 of the body 83_1.

[0118] Said first end 83_7 is configured to accommodate the upper end 82_2 of the second arm 82 and to be fluidly connected to the first conduit 82_4 of the cooling device of the second arm 82. It follows from these arrangements that the first end 83_7 of the second channel 83_4 is open opposite the opening 81_7 made in the main profile 81_1 of the first arm 81.

[0119] The second end 83_8 is configured to be fluidly connected to the second conduit 81_5 of the main cooling device of the first arm 81.

[0120] More specifically, in the embodiment described here with reference to [Fig.6], the second channel 83_4 comprises two parts, namely: - a first recess into which the upper end 82_2 of the second arm 82 is inserted. Said first end 83_7 is therefore one of the ends of said first recess, the latter being dimensioned to accommodate said upper end 82_2, in particular so that the first conduit 82_4 of the second arm 82 is inserted into it, as illustrated in [Fig.6] by way of no limitation. Advantageously, said first recess may include a thread or any other means suitable for the screw connection of said upper end 82_2. - a second recess in communication with said first recess and to which said second end belongs 83_8.

[0121] It should be noted that the invention is not limited by the fact that the first conduit 82_4 of the second arm 82 is inserted inside the body 83_1 via the first recess of the second channel 83_4. Thus, according to an alternative embodiment (not shown in the figures), the first conduit 82_4 of the cooling device of the arm 82 can extend substantially to the level of said first end 83_7, and an auxiliary conduit, for example made of electrically conductive material, can be used to facilitate the connection between said first end 83_7 and the first conduit 82_4 of the cooling device of the second arm 82. This auxiliary conduit can either be integrated into the connecting element 83, or into the second arm 82 (for example by being fixed to the first conduit 82_4 of the second arm 82, so as to form an extension of the latter).

[0122] Fig. 7 is a top view of the Z area of ​​the support considered in Fig. 6.

[0123] The interest of [Fig.7] is to allow visualization of an example of realization of the second channel 83_4 of the fluidic circuit, more particularly of a part of the second recess mentioned above and leading to the second end 83_8.

[0124] As can be seen from [Fig.7], the arrangement of said second end 83_8 corresponds to the arrangement of the second conduit 81_5 of the main cooling device of the first arm 81 as shown in Figures 3 and 4.

[0125] Furthermore, and as also illustrated in [Fig.7], said second recess includes an angled part allowing successive access to a substantially central position of the body 83_1 and then to said first recess into which the upper end 82_2 of the second arm 82 is introduced, it being understood that this introduction of the upper end 82_2 is here carried out substantially in the middle of said body 83_1.

[0126] The support 8 of the electrode 1 has been described so far considering that the connecting element 83 is arranged inside the main profile 81_1 of the first arm 81, at the level of the second end 81_3 of said first arm 81. These provisions are however not limiting of the invention which covers other embodiments in which the connecting element 83 is external to the first arm 81.

[0127] More particularly, in these other modes, the connecting element 83 can be fixed to the first arm 81 at its second end 81_3, the latter therefore not being closed in the horizontal direction in which the first arm 81 extends. The fixing between the connecting element 83 and the first arm 81, at said second end 81_3, can be carried out according to any known method, provided that the body 83_1 of said connecting element 83 remains configured to connect the respective current supply systems of the first and second arms 81, 82 as well as to connect the respective cooling devices of the first and second arms 81, 82.

[0128] In such other embodiments, and insofar as the connecting element is no longer integrated into the first arm 81, the electrically insulating material of the casing 83_2 of the connecting element 83 may advantageously be a material capable of withstanding very high temperatures, such as, for example, a non-conductive refractory material. This makes it possible to greatly limit the risk of damage to the connecting element 83 due to vitrifiable materials introduced into the furnace from above, which may fall and potentially melt onto the connecting element 83.

[0129] Furthermore, the invention has also been described so far by considering that the body 83_1 of the connecting element 83 is made of an electrically conductive material so as to allow continuity of current delivery between the first arm 81 (via the first conduit 81_4 of the main cooling device of said first arm 81) and the second arm 82 (via the second conduit 82_5 of the cooling device of said second arm 82), to ultimately supply the electrode 1. Again, such arrangements are not limiting of the invention, and nothing precludes considering alternatives in which the current supply system of the first arm 81 and / or the current supply system of the second arm 82 consist of suitable cables separate from conduits useful for the circulation of a coolant.Therefore, it is also possible to consider passing such cables within the body 83_1 of the connection element 83, for example via dedicated channels within said body 83_1, so that the latter can be made of a non-conductive material.

Claims

Demands

1. Element (83) for connecting a first horizontal arm (81) and a second vertical arm (82) of a support (8) for a fusion electrode immersed from the surface of a fusion bath, each arm comprising a current supply system and a fluidic cooling device, the electrode (1) being intended to be fixed to one end of the second arm, the connecting element comprising a body (83_1) surrounded by a casing (83_2) made of electrically insulating material, said body being configured to connect the respective current supply systems of the first and second arms and to connect the respective cooling devices of the first and second arms.

2. Connection element (83) according to claim 1, the cooling device of each arm comprising a first conduit and a second conduit, the second arm having a so-called "lower" end (82_1) to which the electrode is intended to be attached and an opposite so-called "upper" end (82_2), the body comprising a fluidic circuit comprising first and second channels configured such that: - the first channel (83_3) has opposite first and second ends, the first end (83_5) opening at the level of the casing and configured to be fluidically connected to the first conduit (81_4) of the first arm, the second end (83_6) being located inside the body and configured to be fluidly connected to the second conduit (82_5) of the second arm, - the second channel (83_4) has opposite first and second ends opening at the level of the casing,the first end (83_7) being configured to accommodate the upper end of the second arm and to be fluidly connected to the first conduit (82_4) of the second arm, the second end (83_8) being configured to be fluidly connected to the second conduit (81_5) of the first arm.

3. A connecting element (83) according to claim 2, wherein the second channel (83_4) comprises, at the first end (83_7) of said second channel, means adapted for connection by screwing the upper end of the second arm, for example by tapping.

4. Connecting element (83) according to any one of claims 1 to 3, wherein the electrical insulating material has a dielectric strength of at least 2.5 kV / mm, preferably of at least 5 kV / mm, even more preferably of at least 10 kV / mm.

5. Connecting element (83) according to any one of claims 1 to 4, wherein the body is made of electrically conductive material.

6. Connecting element (83) according to claim 5, wherein the electrically conductive material of the body has an electrical conductivity of at least 3x07 Siemens / m, more preferably of at least 3.5x07 Siemens / m, even more preferably of at least 4x07 Siemens / m, even more preferably of at least 5x07 Siemens / m, the electrically conductive material being for example copper, aluminum, silver or an alloy using one or more of these metals, for example cupro-aluminum, brass, a silver alloy.

7. An arm, referred to as the "first arm" (81), for a support (8) for a fusion electrode immersed from the surface of a fusion bath and comprising a second vertical arm (82) having a "lower" end (82_1) to which the electrode (1) is intended to be attached and an opposite "upper" end (82_2), the first arm being intended to extend horizontally when integrated into the support and comprising: - a profile (81_1) comprising a first end (81_2) configured to be attached to a power supply housing and an opposite second end (81_2), said second end further comprising an opening (81_7) configured to receive the upper end of the second arm, - a power supply system and a fluidic cooling device, referred to as the "main cooling device", arranged inside the profile, - a connecting element according to any one of the claims 1 to 6,said connecting element being arranged inside the profile at its second end.

8. Arm (81) according to claim 7, wherein the profile is a metal profile, preferably of parallelepiped shape.

9. Arm (81) according to any one of claims 7 to 8, wherein the main cooling device comprises a first conduit (81_4) and a second conduit (81_5), said first conduit and / or second conduit being made of electrically conductive material so as to form the current supply system.

10. Arm (81) according to claim 9, wherein only one conduit among the first and second conduits of the main cooling device is made of an electrically conductive material, for example the first conduit, the other conduit, for example the second conduit, being made of an electrically insulating material, for example polyethylene.

11. Arm (81) according to any one of claims 9 to 10, wherein the electrically conductive material of a conduit (81_4, 81_5) of the main cooling device has an electrical conductivity of at least 3x07 Siemens / m, more preferably of at least 3.5x07 Siemens / m, even more preferably of at least 4x07 Siemens / m, even more preferably of at least 5x07 Siemens / m, such as, for example, copper, aluminum, silver or an alloy using one or more of these metals, for example, cupro-aluminum, brass, a silver alloy.

12. Arm (81) according to any one of claims 9 to 11, wherein the first conduit (81_4) of the main cooling device is surrounded by an electrically insulating material, said arm further comprising another fluidic cooling device, referred to as the "auxiliary cooling device", arranged inside the profile (81_1), around the electrically insulating material surrounding the main cooling device and around the connecting element (83).

13. Arm (81) according to any one of claims 7 to 12, wherein the profile (81_1) extends over a distance greater than 2000 mm, preferably greater than 3500 mm, more preferably greater than 4000 mm, even more preferably greater than 5000 mm, for example up to 6000 m.

14.

15.

16.

17.

18. Kit comprising the following elements: - a first horizontal arm (81) and a second vertical arm (82), each arm comprising a current supply system and a fluidic cooling device, - a connection element (83) according to any one of claims 1 to 6, said elements being intended to be assembled together to form a support (8) for a fusion electrode immersed from the surface of a fusion bath, the electrode (1) being intended to be fixed to one end of the second arm. Kit according to claim 14, wherein the first arm (81) conforms to any one of claims 7 to 13. A support (8) for a fusion electrode immersed from the surface of a fusion bath comprising a first horizontal arm (81) and a second vertical arm (82), each arm comprising a current supply system and a fluidic cooling device, the electrode (1) being intended to be fixed to one end of the second arm, said support further comprising a connecting element (83) according to any one of claims 1 to 6. A support (8) according to claim 16, wherein the first arm (81) conforms to any one of claims 7 to 12. A fusion furnace comprising one or more supports (8) for fusion electrodes according to any one of claims 16 to 17.

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