Instrumented plate for oven

Description

technical field

[0001] The invention relates to an instrumented plate intended for the control of a refractory part of a furnace, in particular a metallurgical or glass furnace, notably to determine the opportune time for repair or shutdown of the furnace.

[0002] The invention also relates to a furnace comprising a refractory part subjected to high temperatures and such an instrumented plate arranged to control said refractory part, in particular to assess the thickness, average temperature, or state of damage of said refractory part. Previous art

[0003] Generally speaking, a "furnace" is an installation or reactor comprising an enclosure and a heating system adapted to establish a temperature above 800°C in said enclosure.

[0004] A furnace is used in particular for the production of molten products, for example in the manufacture of metallurgical or glass products, but also for waste incineration or energy production from fuels. For example, a reaction gas turbine is considered a furnace.

[0005] An oven can consume gas or other fuels, or be equipped with electric heating elements, or be heated by induction.

[0006] A metallurgical furnace can be a facility in which a metal precursor is reduced to produce pig iron. A metallurgical furnace can also be a metalworking furnace or a remelting furnace. For example, a furnace might be a blast furnace used to produce pig iron from iron ore or to remelt copper cathodes produced by another process, such as for manufacturing copper cable.

[0007] A glass furnace can be an installation in which the melting and refining of a vitrifiable mixture is carried out, in particular comprising oxides, carbonates, sulfates and nitrates.

[0008] The walls of a furnace chamber are typically protected with a refractory lining. The refractory lining is subjected to different chemical and mechanical stresses depending on the application. Its composition is adapted accordingly. For example, the interior of a glass furnace is typically subjected to a temperature of approximately 1500°C. The refractory lining in contact with molten glass must also resist abrasion from the molten glass.

[0009] The composition of the refractory lining is specifically adapted to the intended application.

[0010] For example, the refractory lining in contact with molten glass or its vapors is classically made up of a refractory product of the Alumina-Zircone-Silica type (AZS for short) generally containing 30 to 45% by mass of zirconia, a product with a very high zirconia content (typically more than 85% by mass of zirconia), a product with a high alumina content (typically more than 90% by mass of alumina), or a zircon product, or a chromium oxide product.

[0011] In a copper cathode melting furnace, the refractory lining is usually SiC-based.

[0012] In a blast furnace for iron production, refractory linings made of SiC, corundum, SiAlON, carbon or mullite are classically used, depending on the area of ​​the furnace considered.

[0013] To optimize the lifespan of the refractory lining, measurements can be taken inside or outside the furnace. These measurements allow for more precise planning of repair operations, particularly hot repairs, or replacement of the refractory lining.

[0014] For example, temperature readings can be taken using infrared thermography, but this is only possible in areas visually accessible to an infrared camera, which excludes certain parts of the oven lining. Furthermore, this method generally does not allow for continuous monitoring.

[0015] Measurement devices are known that allow continuous, non-intrusive monitoring, meaning without penetrating the furnace chamber. In particular, WO2020025492A1 describes, for measuring the wear of a refractory lining in a glass furnace, the use of an optical fiber network sandwiched between the cold face of the furnace wall blocks and a thermally insulating layer, or through said insulating layer. Furthermore, EP1527306A1 describes, for measuring the temperature in an induction metallurgical furnace, the use of an optical fiber arranged within a fibrous mat between a dense refractory lining and an inductor insulator.

[0016] US-A 5319671 describes a device for measuring the temperature of a refractory wall of a metallurgical furnace comprising an array of electronic sensors or optical fibers housed in a prefabricated plate mounted in the furnace wall, the plate containing fibers bonded in a ceramic matrix.

[0017] However, prior art solutions that allow for continuous monitoring pose problems reliability, and in particular resistance to high temperatures, especially when the sensors include polymer parts, disruption of furnace operation, in particular disruption of heat exchange through the cold side of the refractory lining, thermomechanical stresses resulting from the attachment of the sensors to the refractory lining, and installation and maintenance, particularly in the event of sensor failure.

[0018] There is therefore a permanent need for a solution that is easy to implement (installation, maintenance) and that allows the refractory lining of a furnace to be controlled continuously and reliably, without significantly altering the behavior of the furnace, and in particular without altering the thermomechanical stresses exerted on the refractory lining, or disrupting heat transfers through the refractory lining.

[0019] One aim of the invention is to meet, at least partially, this need. Summary of the invention

[0020] The invention relates to an instrumented plate for monitoring a refractory part of a furnace, and in particular a refractory part whose hot face is subjected to a temperature exceeding 800°C, or even exceeding 1000°C, 1200°C, 1400°C or 1500°C, the instrumented plate comprising: a support plate, preferably traversed by a plurality of orifices, at least partly made of a material consisting of fibers bonded together by a ceramic matrix, called a "ceramic matrix composite" or made of a precursor of said ceramic matrix composite, preferably made of a ceramic matrix composite or a precursor of said ceramic matrix composite; a sensor carried by said support plate.

[0021] As will be explained in more detail later in the description, the inventors discovered that a ceramic matrix composite plate provides a particularly well-suited sensor substrate for the intended applications. A ceramic matrix composite offers good resistance to high temperatures and effectively protects the sensor, particularly from mechanical shocks. It is also easy to handle and install.

[0022] Furthermore, the inventors discovered that the presence of the openings limits interactions with the refractory material. In particular, the presence of the instrumented plate on the refractory material adds virtually no mechanical stress or thermal insulation. Therefore, the furnace does not need to be modified due to the placement of the instrumented plate, especially when the face of the refractory material on which the instrumented plate is immobilized is cooled, for example, by blowing air.

[0023] Furthermore, the inventors discovered that the presence of the holes significantly reduces the transmission of mechanical stresses to the sensor. Reliability is therefore improved.

[0024] Finally, the instrumented plate can be shaped to fit this face of the refractory part, which improves the accuracy of the measurements taken.

[0025] The instrumented plate may also include, in particular, one or more of the following optional and preferred features: at least one orifice, preferably each orifice, has an equivalent diameter greater than 3 mm, and / or less than 50 mm; the percentage of perforation, equal to the ratio of the cumulative area of ​​the orifices, or "perforated area", to the area of ​​the support plate, said area including the perforated area, is greater than 5%, preferably greater than 50%, and / or less than 95%; the sensor is a sensor for measuring an optical, electrical or acoustic signal, preferably chosen from among a thermocouple, a piezoelectric sensor, a strain gauge, an optical fiber, an ultrasonic wave propagation fiber, and an acoustic sensor; the support plate has a thickness between 1 and 20 mm; the orifices, identical or different, preferably identical, are regularly distributed in at least one "perforated" area of ​​the support plate;the support plate comprises several said perforated zones and at least one reinforcement zone, or "non-perforated zone", separating two said perforated zones, the reinforcement zone having a width greater than the largest dimension of said orifices; the ceramic matrix composite or the ceramic matrix composite precursor comprises a plurality of superimposed textiles, one or more sensors, identical or different, for example a temperature sensor and a deformation sensor, being preferably sandwiched between two said textiles;the sensor is embedded within the ceramic matrix composite or the precursor of said ceramic matrix composite, preferably sandwiched between two textiles, or integrated into the arrangement of the fibers of the ceramic matrix composite or the precursor of said ceramic matrix composite, for example as weft yarn, warp yarn or knitting yarn, or housed in a recess provided or inserted in the ceramic matrix composite or the precursor of said ceramic matrix composite, preferably in a recess provided on a large face of the support plate, for example in a pocket, a sheath, a tube open at both ends, a sleeve open at one end or a shell, or fixed to a large face of the support plate, preferably by means of a refractory adhesive, tape, staple or wire; the fibers represent more than 25% and less than 70% of the volume of the ceramic matrix composite;the ceramic matrix composite comprises, by mass percentage, more than 80%, more than 90%, more than 95%, or even substantially 100% of one or more of the following oxides or non-oxides: Al 2 O 3 , ZrO 2 , HfO 2 , Cr 2 O 3 , MgO, CaO, SiO 2 , SiC, Si 3 N 4 , SiAlON, AlN, Si 2 ON 2 , BN, B 4 C, silicon oxycarbide, MoSi 2 , and carbon C ; the ceramic matrix composite exhibits a compressive crush strength greater than 10 MPa, and / or a thermal conductivity between 20°C and 500°C greater than 2.0 Wm ⁻¹ .K ⁻¹ .

[0026] The invention also relates to a measuring device comprising an instrumented plate according to the invention and a measuring device in communication with the sensor so as to receive and interpret a signal emitted by the sensor.

[0027] Preferably, the measuring device uses the signal it receives from the sensor to provide information relating to: the thickness of the refractory part, especially when the instrumented plate is fixed to the cold face of a block and the hot face of the refractory part is in contact with a molten material, for example glass or metal, or the average temperature of the refractory part, or the physical state of the refractory part, for example the presence of a phase transformation or damage to the refractory part, for example spalling, an internal crack, a phase change related to seepage, or oxidation in the case of a refractory part into a non-oxide material.

[0028] A person skilled in the art knows how to choose the sensors best suited to the desired information.

[0029] The invention further relates to an oven comprising a measuring device according to the invention. The oven may further comprise, in particular, one or more of the following optional and preferred features: the furnace is selected from among a glass melting furnace, a metallurgical furnace, an incinerator, a gasifier, a combustion chamber for energy production, and a gas reforming plant for the chemical industry; the furnace contains a molten material, in particular molten glass or metal, or a gaseous environment at a temperature above 800°C; the furnace has a refractory part and the instrumented plate is positioned in contact with a face of the refractory part, preferably so as to conform to said face; the refractory part is a side wall or a floor of a furnace vessel or a block of said side wall or of said floor;the refractory part has a face intended to be at a temperature above 800°C, called the "hot face" and a face away from said hot face, called the "cold face", and the instrumented plate is placed in contact with said cold face, the hot face preferably being in contact with the inside of the furnace; the refractory part is a first refractory block adjacent to a second refractory block, and the instrumented plate is placed between said first and second refractory blocks, preferably pinched, or "compressed", between said first and second refractory blocks; the first refractory block is denser than the second refractory block, which may in particular be an insulating block; the instrumented plate extends against a vertical or horizontal face of the refractory part, in particular, for example, if the refractory part is a throat block or a tank block, respectively;The surface area of ​​the instrumented plate, which includes the surface area of ​​the orifices, represents more than 20% of the surface area of ​​the face of the refractory part against which it is applied; the coefficient of thermal expansion of the ceramic matrix composite of the instrumented plate is equal to that of the material of the refractory part plus or minus 20%; the instrumented plate is fixed to the refractory part in such a way as not to exert thermomechanical stresses on the refractory part under the effect of a dimensional change of the refractory part resulting from nominal operation of the furnace. Brief description of the figures

[0030] Other features and advantages of the invention will become apparent upon reading the detailed description that follows and examining the attached drawing in which: [ Fig 1 ] there figure 1 schematically represents half a cross-section of an example of a glass furnace; Fig 2 ] there figure 2schematically represents half a cross-section of an example of an induction metallurgical furnace; Fig 3 ] there figure 3 schematically represents, from the front, a first example of an instrumented plate according to the invention; Fig 4 ] there figure 4 schematically represents, from the front, a second example of an instrumented plate according to the invention; Fig 5 ] there figure 5 schematically represents, from the front, a third example of an instrumented plate according to the invention; Fig 6 ] there figure 6 schematically represents, from the front, a fourth example of an instrumented plate according to the invention, in the service position; Fig 7 ] there figure 7 schematically represents, from the front, a fifth example of an instrumented plate according to the invention; Fig 8 ] there figure 8 schematically represents, in cross-section, a sixth example of an instrumented plate according to the invention; Fig 9 ] there figure 9schematically represents, in cross-section, another example of an instrumented plate according to the invention; Fig 10 ] there Figure 10 schematically represents, in cross-section, yet another example of an instrumented plate according to the invention; Fig 11 ] there figure 11 illustrates the bending deformability of an instrumented plate in a preferred embodiment of the invention; [ Fig 12 ] there figure 12 illustrates the positioning of an instrumented plate according to the invention between refractory blocks of a furnace; [ Fig 13 ] there figure 13 represents, in vertical section, an embodiment in which two superimposed blocks are inserted between which an instrumented plate is inserted.

[0031] Identical references are used to designate identical or similar organs. Definitions

[0032] A "refractory section" refers to a component of the furnace made of a refractory material. A refractory section can be a single block, but also an assembly of blocks, such as a side wall of a furnace or a hearth, often formed by casting. A refractory section is typically made of a molten or sintered material. Typically, an insulating layer covers the cold side of the refractory section to limit heat transfer. This insulating layer may be absent, for example, in a portion of the refractory lining of an incineration furnace or in a blast furnace.

[0033] Traditionally, when a refractory material has a hot surface, its "thickness" is its dimension measured perpendicular to that hot surface. For example, for a side block of a tank in contact with molten glass or metal, the thickness is measured along a roughly horizontal line directed towards the molten glass or metal. For a hearth, the thickness is measured vertically.

[0034] The "hot face" is the face of a refractory component exposed to a space within the furnace that is above 800°C, for example, containing, or intended to contain, molten glass or metal. The hot face may be in contact with, or intended to be in contact with, molten glass or metal and / or with the gaseous environment above the molten glass or metal. The hot face is thus the face of the refractory component that is subjected to, or intended to be subjected to, the highest temperatures. By extension, all the hot faces of the blocks on the side wall of the glass or metal melting pot can also be referred to as the "hot face." The upper surface of the hearth can also be considered the "hot face."

[0035] The adjective "hot" is used for clarity. Before the furnace is put into service, the "hot" side is the side that is intended to be subjected to the highest temperatures after commissioning.

[0036] A "cold face" is a surface of the refractory material that is not exposed to a space within the furnace heated to over 800°C; that is, it is insulated from this space by material from the refractory material. The cold face opposite the hot face is the face furthest from this space. Typically, the cold face opposite the hot face is the face that, during operation, is subjected or intended to be subjected to the lowest temperatures. The cold face may be parallel to the hot face.

[0037] The "service position" is the configuration in which the instrumented plate is supported on one face, for example the cold face, of the refractory part so as to acquire a measurement relative to said refractory part.

[0038] The term "plate" classically refers to a piece having two large faces that are substantially parallel to each other and having a small thickness relative to the surface area of ​​one of said large faces, the direction of the plate's thickness being perpendicular to said large faces. The ratio "maximum thickness / surface area of ​​the large face" is preferably less than 1 / 500 m -1, preferably less than 1 / 1000 m -1, preferably less than 1 / 5000 m -1, preferably less than 1 / 10000 m -1.

[0039] The "surface area" of a plate is the area within the perimeter of the plate. The surface area of ​​the plate therefore includes the area defined by the material of the plate and the area of ​​the holes that pass through the plate.

[0040] The thickness of the instrumented plate is its dimension measured perpendicular to the large face of the instrumented plate intended to be positioned or placed against the refractory part.

[0041] An orifice that passes through a plate is an orifice that has first and second openings leading to the first and second large faces of the plate. An orifice is preferably straight and extends perpendicularly to the large faces of the plate. The "surface area" of an orifice is the surface area of ​​its opening on the side of the refractory material against which the plate is intended to be placed. The length of an orifice is the longest dimension of this opening. Its width is the longest dimension of this opening perpendicular to the length.

[0042] By "perforated surface" we mean the cumulative surface area of ​​all the surfaces of the orifices.

[0043] The percentage of perforation of a perforation area (or of the instrumented plate) is the ratio of the perforation area of ​​said perforation area (or of said instrumented plate, respectively), to the area of ​​said perforation area (or of said instrumented plate, respectively), which includes said perforation area.

[0044] The "equivalent diameter" of an orifice is the diameter of a disk with the same surface area as that orifice.

[0045] By "molten product", often called "electro-fused", we mean a product obtained by complete solidification of a composition in the liquid state obtained by melting a mixture of suitable raw materials in an electric arc furnace or by any other suitable technique.

[0046] The term "sintered product" means a product obtained by mixing suitable raw materials, then shaping this mixture in its raw state and firing the resulting raw piece at a temperature and for a sufficient time to achieve sintering of this raw piece, said firing being carried out in situ during use.

[0047] Ceramic Matrix Composite, or CMC, is classically defined as a product composed of fibers bonded together by a ceramic matrix. The fibers will be chosen according to the environment in which the ceramic matrix composite will be placed, particularly based on temperature, corrosion, thermal cycling, expansion, and the nature of the refractory material to be lined.

[0048] The arrangement of the fibers, which forms the fibrous support for the matrix, is chosen according to the desired shape of the ceramic matrix composite and the ease of attaching the sensor. For example, a stack of woven or layered fibers is well-suited for simple plates, a filament winding is well-suited for plates with a geometry of revolution, and a filamentary placement is well-suited for large, complex shapes.

[0049] A "ceramic matrix composite precursor" is a material capable of transforming into said ceramic matrix composite under the effect of heating, preferably above 600°C, preferably above 700°C, preferably under the effect of sintering.

[0050] The fibers are typically in the form of a textile. CMC can then be described as a "ceramic matrix textile".

[0051] A textile can be: an organized two-dimensional structure of fibers or yarns, including a knit, braid, fabric, or a random two-dimensional structure of fibers or yarns, this random structure not being preferred.

[0052] A textile is distinguished in particular from a fibrous mat, in which the organization of the fibers or threads is random in the three dimensions of space.

[0053] A "fiber" is a filament whose length is greater than 5 times its equivalent diameter. The "diameter" of a fiber is the diameter of a disk with the same area as its cross-section at half its length.

[0054] A "thread" is an assembly of fibers which, in cross-section, has more than 10 and preferably less than 500,000 fibers, and whose length is greater than 5 times the diameter.

[0055] The term "ceramic" refers to a product that is neither metallic nor organic. For the purposes of this invention, carbon is considered a ceramic product.

[0056] By "skin" we classically mean the peripheral region of a molten block, made up of the molten material that was less than 5 millimeters (mm) from the mold wall when it solidified.

[0057] By "machining" we mean a grinding operation by which the surface of a refractory part is machined in order to obtain a precise surface geometry.

[0058] For clarity, the chemical formulas of oxides are used to designate the contents of these oxides in a composition. For example, "ZrO2", "SiO2" or "Al2O3" designate the contents of these oxides and "zirconia", "silica" and "alumina" are used to designate phases of these oxides made up of ZrO2, SiO2 and Al2O3, respectively.

[0059] Unless otherwise stated, all oxide contents are mass percentages based on the oxides. A mass content of an oxide of a metallic element refers to the total content of that element expressed in the form of the most stable oxide, according to the usual industry convention.

[0060] A transverse plane of an object is a plane perpendicular to the direction of the length of said object.

[0061] By "horizontal" and "vertical" we mean an orientation forming with a perfectly horizontal and vertical plane, respectively, an angle of less than 5°, or even less than 2°, or even less than 1°.

[0062] “Contain” or “understand” or “present” should be interpreted in a non-limiting manner. Detailed description Oven - part refractory

[0063] A furnace according to the invention can be any conventional furnace, in particular chosen from glass furnaces, metallurgical furnaces, waste incineration plant furnaces, gasifiers, power generation furnaces, in particular gas turbines, and gas reforming plants for the chemical industry.

[0064] The invention preferably relates to a glass furnace. However, the invention is not limited to this preferred application.

[0065] There figure 1 schematically represents half a cross-section of a glass furnace 10. In particular, a tank 12, a metal structure 14 and a superstructure 16 are distinguishable.

[0066] The vat 12, intended to contain the molten glass, has a vertical side wall 22 and a base 24. The side wall 22 is conventionally made up of lateral vat blocks which extend over the entire height of the vat, up to an upper edge 25.

[0067] A thermally insulating layer, not shown on the figure 1 It is typically positioned against the cold side of the wall. In particular, the insulating layer can encircle the side wall of the glass melting tank in the furnace.

[0068] The superstructure 16 classically comprises, at its base, an intermediate layer 18 by which it rests on the metal structure, a side wall 26 resting on the intermediate layer 18, and a vault 28. Burners, not shown, are arranged in the side wall 26 and operate alternately.

[0069] The metal structure 14, typically made of cast iron, surrounds the side wall 22 of the tank externally. It supports the weight of the superstructure 16.

[0070] The intermediate layer 18 comprises, and preferably consists of, pieces with a basic nose 20 (tuckstones) " in English).

[0071] The furnace enclosure is thus defined by different parts subjected to different chemical and mechanical stresses. The invention is particularly useful for monitoring a refractory part in contact with molten glass, and in particular for monitoring the condition of the side wall of the vessel and the hearth.

[0072] The refractory part can be in particular the vault, the side wall of the superstructure, the intermediate layer, the side wall of the tank, the floor, a block of the vault, the side wall of the superstructure, the intermediate layer, the side wall of the tank, or the floor.

[0073] The invention also relates to a metallurgical furnace. In particular, the figure 2This schematically represents, in cross-section, a crucible of an induction furnace, for example for the remelting of metals and / or their treatment, for example dephosphorization. This crucible has a side wall 110 which extends, substantially vertically, from a bottom 112.

[0074] The lateral wall 110 of the crucible typically comprises, from the outside to the inside of the crucible: a support layer 114, on which the inductor 116 is fixed; at least one layer of thermal insulation 118; at least one layer of electrical insulation 120; a refractory coating 122 defining the inner surface 128 of the crucible.

[0075] The base 112 typically comprises, from the outside to the inside of the crucible: a base 130, substantially horizontal; a refractory lining 122' defining the inner surface 128 of the crucible.

[0076] During operation, the temperature can typically exceed 800°C, or even 1000°C or 1200°C, or even 1300°C or 1400°C, depending on the metal in question - The temperature is generally less than 1700°C.

[0077] The refractory part may in particular be the support layer 114, the thermal insulation layer 118, the electrical insulation layer 120, the refractory lining 122 directly in contact with the metal, the sole 130, the refractory lining 122' or one or more blocks of these thermal insulation layer 118, electrical insulation layer 120, refractory lining 122, sole 130, and refractory lining 122'.

[0078] The refractory part can be a part of the oven that is not in contact with the inside of the oven chamber.

[0079] The refractory part may be, in particular, a throat lintel or block, a soldier block, a refractory brick or sidewall block, a corner block, a tuckstone, a paving tile or pavement, a crown brick or pier, a tuyere surround brick or block, a pouring hole or channel brick, an electrode block, an injector block, a refractory spout lip, an injector block, a glass furnace throat, a part of a furnace heat exchanger, in particular a heat exchanger tube, plate, or tile. refractory, in particular a boiler lining tube or tile,a protective shell for a heater tube of an incinerator, a tile of an incinerator, a ceramic part of a solar absorber, a tile or protective part of a combustion turbine chamber, in particular a gas turbine chamber, a block or surround of a nozzle or burner.

[0080] Preferably, the refractory part is rigid, such as a block or an assembly of blocks, preferably consolidated, and in particular sintered or melted.

[0081] The invention is particularly well-suited for a refractory section comprising a hot face in contact with the interior of the furnace, preferably in contact with molten material, and a cold face opposite the hot face. The instrumented plate makes it possible, in particular, to detect abnormal or excessive infiltration of molten material into the refractory section, such infiltration not always detectable with conventional furnace monitoring tools.

[0082] The refractory part can be a molten product, that is to say obtained by melting a refractory mixture at a temperature above 1000°C, preferably above 1500°C, or even above 1800°C.

[0083] The refractory part can be a sintered product, that is to say obtained from a refractory mixture shaped and sintered, preferably at a temperature above 600°C, preferably above 1000°C.

[0084] The chemical composition of the refractory part can be a composition known for conventional coatings, in the intended application.

[0085] The refractory part is preferably formed from a refractory block or an assembly of several refractory blocks.

[0086] Preferably, the said refractory block(s) are prefabricated, that is to say obtained from a refractory mixture, for example refractory concrete or rammed earth, shaped and then subjected to steaming, preferably at a temperature below 600°C.

[0087] The refractory part is preferably made up of more than 95%, preferably more than 97%, preferably more than 99%, preferably more than 99.5%, preferably more than 99.9% of its mass, of refractory oxides and / or non-oxides.

[0088] In one embodiment, the refractory part has a chemical composition, in mass percentage on the basis of oxides, such that Al 2 O 3 + ZrO 2 + SiO 2 + Cr 2 O 3 > 80.0%.

[0089] In one embodiment, the refractory part, preferably fused, has a chemical composition comprising, as a mass percentage on the basis of oxides, more than 0.5%, or even more than 1.5%, or even more than 3.0%, or even more than 4.0%, or even more than 5.0%, or even more than 6.0%, and / or less than 10.0%, or even less than 9.0%, or even less than 8.0% of a zirconia stabilizer, in particular CaO and / or Y2O3 and / or MgO and / or CeO2, preferably Y2O3 and / or CaO, preferably Y2O3.

[0090] In one embodiment, the refractory part is a molten product and may further comprise one or more of the following optional characteristics: at least part, preferably all, of the surfaces of the refractory portion intended to be exposed to the environment inside the furnace shall have a skin microstructure. In particular, preferably at least part, preferably all, of the vessel surface and / or the upper transition surface shall have a skin microstructure; the surface with the skin microstructure shall have a crystal density less than 30 times, or even less than 25 times, or even less than 20 times the crystal density measured at a depth of 4 cm below said surface;

[0091] Obtaining a skin-like microstructure on the surface of a molten part, that is, a molten product, presents no particular difficulty for those skilled in the art. In particular, those skilled in the art know that a microstructure can be made finer at the surface by increasing the solidification rate of the molten material.

[0092] When the molten material is poured into the mold, the mold's properties and temperature can be adjusted to ensure sufficiently rapid cooling to create a skin microstructure. For example, when the mold is initially at room temperature, a skin microstructure forms on the surface in contact with, or near, the mold walls. If, contrary to standard practice, this skin is not removed during machining, a skin microstructure is then formed on the unmachined surfaces of the refractory material.

[0093] However, limited machining (surfacing) allows a skin microstructure to be preserved.

[0094] Of course, the composition, dimensions, shapes and microstructures described above are not exhaustive.

[0095] The fact that the instrumented plate conforms to the shape of the refractory part contributes advantageously to the optimal performance of the sensor. Instrumented plate

[0096] The instrumented plate is an "instrument", in the form of a thin piece or layer, intended for capturing measurements.

[0097] THE figures 3 to 8 represent examples of 300 instrumented plates.

[0098] The instrumented plate can be placed against any face but is particularly useful for covering, at least partially, a face at a temperature above 150°C, above 300°C, above 400°C, and / or below 800°C.

[0099] As illustrated on the figure 6 In the service position, the instrumented plate 300 extends against one face of the refractory part P, in this case the cold face F.

[0100] The portion of the refractory surface in contact with the instrumented plate 300 can be flat, for example, defined by the throat of a glass furnace or a gas turbine tile. It can be a straight or curved flat surface, for example, the face of a nose brick in the specific case of a glass furnace. Preferably, it is flat.

[0101] There figure 6 illustrates an embodiment in which the cold face F of the refractory part, opposite the hot face C, has the general shape of an angle formed by two sides which can in particular extend perpendicularly to each other.

[0102] Preferably, the instrumented plate 300 has, between the large faces G1 and G2, an average thickness e (see figure 8Preferably a constant thickness of less than 40 mm, preferably less than 32 mm, preferably less than 28 mm, preferably less than 22 mm, preferably less than 20 mm, preferably less than 10 mm, or even less than 18 mm or 15 mm, and / or preferably greater than 1 mm, preferably greater than 2 mm, or even greater than 3 mm, or greater than 5 mm. A thickness between 1 and 20 mm, preferably between 2 and 10 mm, is preferred, particularly to allow for easy insertion between the refractory part and the insulating rear part or the outer casing of the furnace while ensuring sufficient mechanical strength for the instrumented plate 300.

[0103] The surface area of ​​the instrumented plate 300 is preferably greater than 100 cm², preferably greater than 200 cm², preferably greater than 300 cm², preferably greater than 400 cm², and / or less than 20,000 cm², preferably less than 15,000 cm² or even less than 10,000 cm².

[0104] Preferably, the instrumented plate 300 extends over more than 20%, or even more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, or even 100% of the surface of the face of the refractory part which receives it, in particular the cold face of the refractory part.

[0105] Preferably, the instrumented plate 300 is prefabricated, that is, manufactured before being applied against the refractory part.

[0106] The instrumented plate 300 preferably has sufficient rigidity to be self-supporting, i.e., to retain its shape when handled at room temperature (20°C). In the operating position, the sensor is thus effectively held in place.

[0107] Preferably, the instrumented plate 300 has a shape complementary to that of the face against which it is intended to be placed or against which it is placed.

[0108] For example, it can be positioned, or even fixed, in a recess on this face, for example in the embodiment in which it is positioned between two adjacent blocks, as illustrated in the Figures 12 and 13 .

[0109] In particular, the instrumented plate 300 can be in the form of a flat plate, with several flat sides, or cylindrical.

[0110] The rigidity of the instrumented plate 300 preferably allows for manual bending, as shown in the figure 11 Advantageously, it can thus better conform to the shape of the face of the refractory part that receives it.

[0111] In one embodiment, the instrumented plate 300 is in the form of a roll before being applied against the refractory part.

[0112] According to the invention, the instrumented plate 300 has a perforated area 302, that is to say, traversed by a plurality of orifices 304.

[0113] The perforation significantly limits the influence of the instrumented plate on the functioning of the refractory section, and in particular its impact on heat transfer. The perforation also reduces the thermomechanical stresses that the instrumented plate exerts on the refractory section.

[0114] The percentage of openwork of an openwork area, preferably of any openwork area, preferably of the instrumented plate, is preferably greater than 5%, preferably greater than 10%, preferably greater than 15%, or even greater than 20%, greater than 30%, greater than 40%, greater than 50%, and / or less than 95%, preferably less than 90%.

[0115] There figure 5 provides an example of an instrumented plate with a very high percentage of perforation, the instrumented plate having the general shape of a grid.

[0116] The shape and distribution of the 304 orifices can take different configurations depending on the dimensions of the refractory part.

[0117] In a perforated area, preferably in each perforated area 302, the orifices 304 are preferably regularly distributed.

[0118] In an openwork area 302, preferably in each openwork area, the openings may have identical or different shapes and / or dimensions, preferably identical.

[0119] The 304 orifices preferably have an oval or round shape, as illustrated in the figure 6 , or polygonal, preferably rectangular, square or diamond-shaped, as illustrated on the figures 3 and 4 .

[0120] Preferably, at least one orifice 304, preferably each orifice of a perforated area 302, preferably of each perforated area, has an equivalent diameter and / or length and / or width greater than 2 mm, greater than 3 mm, and / or less than 300 mm, preferably less than 200 mm, preferably less than 150 mm, preferably less than 100 mm, preferably less than 50 mm.

[0121] Preferably, to minimize the impact on heat transfer, the surface area of ​​each 304 orifice is between 4 mm² and 1000 cm².

[0122] The cross-section of an orifice 304, in a cutting plane perpendicular to the thickness direction of the instrumented plate, can be constant or variable depending on the cutting plane. A variation in cross-section advantageously allows for the local definition of mechanical resistance properties, for example, how the instrumented plate deforms.

[0123] In a perforated area 302, preferably in each perforated area, the orifices 304 are preferably regularly spaced. Preferably, each orifice is separated from any adjacent orifice by a distance greater than 0.5 mm, preferably greater than 1 mm, preferably greater than 2 mm, and / or less than 50 mm, preferably less than 40 mm, preferably less than 30 mm, preferably less than 20 mm, preferably less than 15 mm, preferably less than 10 mm, preferably less than 5 mm.

[0124] An openwork zone 302, preferably each openwork zone, preferably has the general shape of a grid, a mesh or a trellis.

[0125] In one embodiment, the instrumented plate 300 has several perforated areas 302, preferably regularly distributed on the instrumented plate, separated by areas without perforations, called "reinforcement areas" 306, as illustrated in the figure 4In one embodiment, the set of reinforcement areas forms a regular pattern, for example a frame or a grid.

[0126] The reinforced areas contribute advantageously to the mechanical resistance of the instrumented plate.

[0127] The width l of a reinforcement zone, that is to say the smallest distance between the two openwork zones it separates, preferably the width of any reinforcement zone, is preferably greater than 5 mm, preferably greater than 10 mm, preferably greater than 15 mm and / or preferably less than 200 mm, preferably less than 150 mm, preferably less than 100 mm, or even less than 80 mm, and / or greater than once, preferably more than twice, preferably more than three times, and / or preferably less than 20 times the largest dimension of the orifices of the perforated areas it separates.

[0128] Preferably, the thickness of the 306 reinforcement zones is identical to that of the openwork zones.

[0129] The instrumented plate 300 can be kept in contact with the refractory part by any means known in the prior art.

[0130] The face of the refractory part which receives the instrumented plate can be grooved or machined so as to provide a housing or recess allowing the instrumented plate to be fixed, for example by clipping or pinching.

[0131] In general, the instrumented plate is preferably immobilized on the refractory part, so as not to exert thermomechanical stresses on the refractory part under the effect of a dimensional change in the refractory part during the normal or "nominal" operation of the furnace.

[0132] Preferably, it is not fixed over its entire surface, but by fixing points and / or fixing lines.

[0133] In one embodiment, the instrumented plate 300 is interposed between two opposing faces of two adjacent refractory blocks, in particular vertical or horizontal faces. It is preferably compressed between these faces, so that it is not necessary to fix it to said faces.

[0134] In one embodiment, the instrumented plate 300 is immobilized on the face that receives it by complementarity of form with said face.

[0135] The instrumented plate 300 can also be glued to the refractory part. Preferably, the adhesive used to fix the instrumented plate is chosen from mixtures of ceramic powders and binders, preferably applied in liquid form.

[0136] Preferably, the powders are alumina and / or silica and / or mullite powders. Preferably, the binders are chosen from colloidal silica, sodium silicate, organic resins, organic adhesives, and mixtures thereof. The adhesive used may also be a commercial adhesive such as Unifrax's Fixwool FX adhesives.

[0137] The instrumented plate 300 comprises a support plate 310 and one or more sensors 312 carried by the support plate 310, preferably integrated into the support plate 310, as illustrated in the figures 8 to 10 For example.

[0138] In one embodiment, the support plate 310, or even the instrumented plate 300, is manufactured, in particular by sintering, in situ, that is to say on the refractory part. The instrumented plate 300 can then be considered as a "layer" covering the face of the refractory part which receives it, that is to say against which it extends. CMC

[0139] The support plate 310 preferably comprises a ceramic matrix composite, or "CMC", or a CMC precursor.

[0140] A person skilled in the art knows how to adapt a CMC precursor to the desired CMC. Therefore, only the CMC is described in detail below.

[0141] The support plate 310 defines the general shape of the instrumented plate and serves as a support for one or more sensors.

[0142] CMC has proven to be particularly resistant to thermal degradation. CMC also exhibits good resistance to corrosion by sodium vapors.

[0143] Preferably, CMC is sintered, classically under air, at atmospheric pressure.

[0144] Preferably, the CMC has an open porosity, measured by imbibition, according to the principle of Archimedes' thrust, greater than 25%, preferably greater than 30% and less than 45%, preferably less than 35%.

[0145] The CMC preferably has an apparent density greater than 1.4 g / cm³, or even greater than 1.50 g / cm³ and / or less than 2 g / cm³, preferably less than 1.9 g / cm³, preferably less than 1.80 g / cm³.

[0146] In particular, when the instrumented plate is fixed to the cold side of the refractory material, for example by gluing or mechanical fastening, such as by insertion into a groove, it is preferable that the coefficient of thermal expansion (also called the coefficient of thermal expansion) of the CMC not differ from that of the refractory material by more than 20%. The coefficient of thermal expansion of the CMC can be adjusted using techniques well known to those skilled in the art, notably by adapting the composition of the CMC. For example, the coefficient of thermal expansion of silica between 20°C and 1000°C is 0.5 x 10⁻⁶ mK⁻¹, 8.0 x 10⁻⁶ mK⁻¹ for alumina, 4.5 x 10⁻⁶ mK⁻¹ for SiC, and less than 1.0 x 10⁻⁶ mK⁻¹ for carbon.

[0147] In one embodiment, the absolute value of the difference between the thermal conductivity of the CMC and the thermal conductivity of the refractory part is less than 10% of the thermal conductivity of the CMC, preferably less than 2.0 WW 1< .K -1< , between 20°C and 500°C.

[0148] In one embodiment, the CMC exhibits, between 20°C and 500°C, a thermal conductivity greater than 2.0 Wm⁻¹.K⁻¹, preferably greater than 50 Wm⁻¹.K⁻¹, or even greater than 10 Ww⁻¹.K⁻¹, or even greater than 50 Ww⁻¹.K⁻¹.

[0149] Simple tests allow for the determination of the quantities of silica, alumina, SiC, and carbon fibers, and / or the quantity of silica, alumina, SiC, and carbon matrix, to obtain a specific coefficient of thermal expansion and / or a specific thermal conductivity. For example, the thermal conductivity of CMC can be adjusted by combining thermally conductive fibers, such as SiC or graphite fibers, with a more insulating matrix, such as alumina, or by combining a thermally conductive matrix, such as SiC, with more insulating fibers, such as alumina or silica fibers.

[0150] Preferably, the CMC exhibits a 3-point bending strength, measured according to ASTM C1341-13, greater than 3 MPa, preferably greater than 6 MPa, and preferably greater than 10 MPa. Advantageously, its mechanical strength, particularly its impact resistance, is improved.

[0151] Preferably, the CMC, particularly in the form of a ceramic matrix textile, exhibits very high compressive strength, for example, measured as described below, exceeding 5 MPa, and preferably exceeding 10 MPa, which improves sensor stability. This compressive strength is notably superior to that of layers made of fiber webs. (insulating mats) in English).

[0152] To measure the compressive strength of a layer of thickness e, a sample measuring 50 x 50 x 10 mm is extracted, with the 10 mm dimension running along the direction of the thickness e. A load is then applied, at room temperature, to the entire 50 x 50 mm² surface of the sample, along the direction of the thickness, at a rate of 0.1 mm / min. The load is increased until the sample thickness is reduced by half (5 mm). The compressive strength is equal to the load obtained, expressed in newtons, divided by the area over which the load is applied (in this case, 25 cm²).

[0153] Preferably, the CMC has a melting or sublimation temperature above 600 °C, preferably above 1000 °C. Advantageously, it therefore does not need to be cooled in service.

[0154] CMC is preferably composed of one or more of the following oxides or non-oxides: Al₂O₃, ZrO₂, HfO₂, Cr₂O₃, MgO, CaO, SiO₂, SiC, Si₃N₄, SiAlON, AlN, Si₂ON₂, BN, B₄C, silicon oxycarbide, MoSi₂, carbon, particularly in the form of amorphous carbon, graphite, or graphene. It is then particularly resistant to thermal degradation.

[0155] Preferably, CMC consists of more than 90% of its mass, preferably more than 95% of its mass, preferably more than 98% of its mass, preferably more than 99% of its mass, preferably more than 99.5% of its mass, of oxides.

[0156] In particular, preferably, the sum of the contents of Al 2 O 3 , SiO 2 , ZrO 2 , CaO, Na 2 O, MgO, K 2 O, TiO 2 , Fe 2 O 3 , HfO 2 , Cr 2 O 3 , P 2 O 5 and Y 2 O 3 , or "Al 2 O 3 + SiO 2 + ZrO 2 + CaO + Na 2 O + MgO + K 2 O + TiO 2 + Fe 2 O 3 + HfO 2 + Cr 2 O 3 + P 2 O 5 + Y 2 O 3 ", in mass percentage on the basis of the oxides of the CMC , is preferably greater than 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%.

[0157] In one embodiment, the CMC has a chemical composition, expressed as a mass percentage based on the oxides, such that Al₂O₃ + SiO₂ + ZrO₂ + CaO + Na₂O + MgO + K₂O + TiO₂ + Fe₂O₃ + HfO₂ + P₂O₅ + Y₂O₃ > 85%, preferably greater than 90%, or even greater than 95%. Preferably, it has a chemical composition, expressed as a mass percentage based on the oxides, such that the total content of Al₂O₃ + SiO₂ + ZrO₂ + CaO + Na₂O + MgO + K₂O + TiO₂ + Fe₂O₃ + HfO₂, expressed as a mass percentage based on the oxides, is greater than 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%. Preferably, it has a chemical composition, expressed as a mass percentage based on oxides, such that the total content of Al2O3 + SiO2 + ZrO2 + CaO + HfO2 is greater than 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%.

[0158] In one embodiment, the CMC has a chemical composition, in mass percentage on the basis of oxides, such as Al 2 O 3 + SiO 2 > 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%.

[0159] In one embodiment, the CMC presents the following chemical analysis, as a percentage by mass based on oxides and for a total of 100%: SiO2: 47% - 67%, Al2O3: 32% - 52%, oxide species other than Al2O3 and SiO2: < 5%, preferably < 4%, preferably < 3%, preferably < 2%. CMC Fibers

[0160] Preferably, the volume of the fibers represents more than 25%, preferably more than 30%, preferably more than 40%, preferably more than 50%, preferably more than 60% and / or less than 70% of the volume of the CMC material, i.e. without taking into account its porosity, the remainder to 100% being constituted by the ceramic matrix binding the said fibers together.

[0161] The diameter of the fibers, measured at mid-length of the fibers and averaged over the entire set of fibers, is between 3 and 30 micrometers, preferably between 5 and 25 micrometers.

[0162] The fibers are preferably grouped into yarns. Each yarn preferably comprises more than 10, more preferably more than 50, more preferably more than 100 fibers, and preferably several hundred to several thousand fibers. The fibers, preferably the yarns, are preferably continuous and have a length greater than 50 mm, or even greater than 100 mm, or even greater than 1 m, greater than 10 m, greater than 100 m, or even greater than 1000 meters. In one embodiment, the fibers, preferably the yarns, are arranged in the form of a textile, in particular a woven, non-woven, knitted, or braided textile.

[0163] The fibers of the CMC preferably consist of ceramic fibers. Preferably, the fibers are chosen from fibers composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of alumina, fibers composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of silica, preferably composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of amorphous silica, fibers composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of mullite, and fibers composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of glass, preferably washed.

[0164] Advantageously, the CMC then exhibits sufficient mechanical resistance to withstand shocks, as well as sufficient rigidity to be easily handled and assembled to the refractory part without deforming.

[0165] Preferably, the fibers are made of an oxide material comprising preferably more than 50%, preferably more than 60%, or even more than 70%, or even more than 80%, or even more than 90% by mass of Al 2 O 3 and / or SiO 2 and / or ZrO 2, as a percentage by mass on the basis of the oxides.

[0166] The fibers can also be, at least in part, made of a non-oxide material, for example SiC, another carbide, a nitride or an oxynitride.

[0167] Preferably, the fibers in a non-oxide material are chosen from SiC fibers, for example Nicalon ® fibers grades NL; Hi or Hi-S. CMC Matrix

[0168] The ceramic matrix, or "binding phase", of CMC may comprise, by mass percentage, more than 80%, more than 90%, more than 95%, or even substantially 100% of one or more compound(s) chosen from the group formed by α or β SiC, silicon oxycarbide, carbon C, in particular in the form of amorphous carbon, graphite or graphene, Si 3 N 4 , AlN, Silicon oxynitrides including SiAlON and Si 2 ON 2 , boron nitride BN, boron carbide B 4 C, and molybdenum disilicide MoSi 2 .

[0169] The matrix is ​​preferably composed of more than 90%, preferably more than 95%, preferably more than 99%, of oxides, by mass percentage. Preferably, the CMC matrix is ​​composed substantially entirely of oxides.

[0170] In one embodiment, the matrix comprises, preferably is made up of, more than 80%, more than 90%, more than 95%, preferably substantially 100% of its mass, one or more compound(s) chosen from the group formed by Al 2 O 3 , ZrO 2 , Cr 2 O 3 , MgO, CaO and SiO 2 .

[0171] The matrix preferably comprises Al₂O₃ and / or SiO₂, preferably Al₂O₃ and SiO₂. The total content of Al₂O₃ and SiO₂ is preferably greater than 80%, preferably greater than 85%, preferably greater than 90%, preferably greater than 95%, as a mass percentage based on the oxides in the matrix. Preferably, the Al₂O₃ content in the matrix, as a mass percentage based on the oxides in the matrix, is greater than 60%, preferably greater than 65%, preferably greater than 70%, and / or the SiO₂ content in the matrix, as a mass percentage based on the oxides in the matrix, is greater than 15%, preferably greater than 20%, and / or less than 35%, preferably less than 30%. Preferably, the content of oxides other than Al2O3 and SiO2 in the matrix, as a percentage by mass on the basis of the oxides in the matrix, is less than 3%, preferably less than 2%, preferably less than 1%.

[0172] In one embodiment, the silica of the matrix is ​​amorphous. Sensor

[0173] The instrumented plate includes one or more 312 sensors.

[0174] On the figures 3 And 6 à 9 The sensors were represented by dashed lines. They were not shown in the other figures.

[0175] The 312 sensor can be any known type of sensor. It allows for the physical measurement of an optical, electrical, or acoustic signal. It is preferably chosen from among a thermocouple, a piezoelectric sensor, a strain gauge, an optical fiber, an ultrasonic wave propagation fiber, and an acoustic sensor.

[0176] Preferably, the sensor is a temperature sensor, for example a thermocouple or a Bragg grating optical fiber. The sensor can also be a strain sensor such as, for example, one described by WO2017 / 009256.

[0177] According to a particularly advantageous embodiment, the sensor 312 takes the form of a wire or an assembly of wires, fixed to the support plate 310 or incorporated into the support plate 310, preferably incorporated into the CMC of the support plate 310.

[0178] According to a first particular method, as illustrated on the Figure 10The sensor is fixed to the support plate 310 by means of an interface layer 313. The interface layer may be, particularly if the temperature of the face of the refractory portion receiving the instrumented plate, especially the cold face, is less than or equal to 400°C, an adhesive comprising a thermosetting, thermoplastic, or crosslinkable elastomer polymer. Preferably, when the polymer is thermosetting, its degree of crosslinking is greater than 75%, or even greater than 90%. Preferably, when the polymer is thermoplastic, its degree of crystallinity varies from 0% to 80%. Even more preferably, the adhesive comprises more than 50% by mass of polymer(s), for example, polyurethane or epoxy.If the service temperature is greater than or equal to 400°C, the interface layer is preferably an inorganic adhesive, for example a geopolymer-based adhesive, for example including sodium silicate, or for example a platinum- or copper-based adhesive, or for example a refractory adhesive described in the article R. Luhn, E. Zimmermann und G. Köhler, Jena “Anorganische Hochtemperaturklebstoffe - Anwendungsmöglichkeiten und Grenzen” published in “Schweiòen und Schneiden 2000 Vorträge der gleichnamigen Groòen Schweiòtechnischen Tagung in Nürnberg vom 27. bis 29. September 2000”, pages 249 to 252, for example a Pyro-Putty #653 or 2400 ceramic adhesive supplied by Aremco, The thickness of the interface layer is preferably constant, preferably greater than 0.1 mm and / or less than 2 mm, preferably less than 1 mm.In general, the behavior of an adhesive can be modified by adjusting its composition, for example by changing the amount of organic materials (thermosetting polymers, thermoplastics, or crosslinking elastomers), accelerators, retarders, or fluidizers. It is also possible to add fillers, particularly elastomer fillers or fillers made of polymer or mineral fibers.

[0179] According to a second embodiment, the sensor is attached or fixed to the support plate 310 by means of refractory tapes, staples, or wires. In particular, alumina tape, Inconel wire, or even platinum wire can be used, depending on the maximum temperature reached by the face of the refractory portion that receives the instrumented plate.

[0180] According to a third embodiment, the sensor, wired or wireless, is integrated within the support plate 310, in particular within the CMC of the support plate 310. As illustrated in the figure 9 The instrumented plate 300 can, for example, comprise two elementary layers 310a and 310b, for example in the form of textiles, preferably woven, superimposed one on the other, and between which the sensor 312 is arranged. The two elementary layers can be joined together by staples or during sintering to form the CMC. In particular, they can form a housing for the sensor (for example, a thermocouple), for example in the form of a pocket, a tube open at both ends, a sheath open at one end, or a shell.

[0181] There figure 7illustrates an embodiment in which a pocket 314 has been created in the center of a set of rectangular orifices 304. The sensor 312 is arranged inside the pocket 314.

[0182] One or, preferably, both elementary layers are CMCs of the type described above, preferably ceramic matrix textiles. Preferably, at least one, preferably each of the two elementary layers has a thickness greater than 2 mm, preferably greater than 3 mm, preferably greater than 5 mm and / or less than 10 mm.

[0183] According to a fourth embodiment, the sensor is housed in a refractory sheath 316 incorporated into the support plate 310 during its manufacture, or in a channel formed during or after the manufacture of the support plate 310.

[0184] According to a fifth embodiment, the CMC fibers are arranged in the form of a textile, preferably a woven one, and the sensor, preferably in wire form, is incorporated into the textile. The ceramic matrix of the CMC is preferably formed by sintering during the furnace heating process. This embodiment requires a matrix composition that allows for consolidation by firing at a temperature below 800°C.

[0185] According to a sixth embodiment, the CMC fibers are arranged in the form of a textile, preferably a woven one, and the sensor, preferably in wire form, is incorporated into the textile before coating by the matrix and sintering at a temperature of at least 800°C.

[0186] In particular, the CMC fibers can be arranged in the form of a knit, a woven or a braid and the wire sensor can be knitted or woven or braided during the manufacture of said knit, woven or braid.

[0187] The assembly formed by the CMC's knit, woven, or braided material on one side and the sensor on the other is then partially or completely covered with the ceramic matrix. Advantageously, the matrix thus provides protection for the sensor. The sensor is selected to withstand the coating and firing process of the ceramic matrix. This embodiment is particularly suitable for wired or ceramic sensors.

[0188] The incorporation of a wired sensor into the support plate can be carried out according to a preferred plan, preferably in a preferred direction or according to a particular pattern.

[0189] The instrumented plate may include several sensors, for example: several temperature sensors, for example two different optical fiber networks; a temperature sensor and a strain sensor.

[0190] The sensors can all be placed between the same two textiles, or between different textiles. Measuring device

[0191] The measuring device 320, which was only shown on the figure 3 , is intended for the control of sensor 312, in particular to receive and interpret the signal emitted by the sensor.

[0192] The measuring device 320 can be connected to the sensor by means of cables 322, for example connecting it to connection terminals 324 integrated into the instrumented plate 300. For clarity, the "sensor" 312 is then considered to include the part which captures the signal to be measured, classically a transducer, and the electrical lines which connect this part to the connection terminals 324.

[0193] Preferably, the cables and connection terminals are made of a refractory metal resistant to temperatures exceeding 400°C, for example, platinum. A refractory and conductive platinum-based adhesive can be used to improve electrical contacts.

[0194] In a preferred embodiment, the measuring device 320 is not connected to the sensor 312. The sensor can in particular define a loop allowing a non-contact measurement, by induction.

[0195] The measuring device typically includes a processor, computer memory and software configured to determine, from the signal received from the sensor, a property relating to the state of the refractory part, for example the average temperature or a temperature distribution or an average residual thickness or a residual thickness distribution.

[0196] Any conventional measuring device can be used. In particular, the processing, analysis and recording of the electrical property measured by the sensor and its variations can employ amplification, filtering, multiplexing and digitization methods known to those skilled in the art in the field of sensors.

[0197] Communication between the sensor and the measuring device can be achieved via wired or wireless means, for example via Wi-Fi or Bluetooth®.

[0198] Preferably, the measuring device is programmed to record the sensor signal at regular time intervals. Heating and cooling

[0199] The furnace may include a cooling system, for example a water or air box, arranged to cool the face receiving the instrumented plate, in particular the cold side, and / or the instrumented plate itself. Preferably, the instrumented plate is positioned between the cold side of the refractory section and the cooling system.

[0200] Preferably, the cooling system is primarily aimed at cooling the cold face of the refractory part, with the sensor being protected by the ceramic matrix.

[0201] The oven may also include a heating device, such as a heating element. Such heating can be useful for limiting thermal shock and temperature gradients within the thickness of the refractory material. Manufacturing

[0202] The refractory part and the instrumented plate can be manufactured by all conventional manufacturing processes.

[0203] The manufacturing process for the instrumented plate may include the following steps: arrangement, around the fibers, of a slip suitable for forming a ceramic matrix after consolidation, for example by impregnation of one or more fabrics or webs, preferably fabrics or webs of yarns, preferably of ceramic yarns; if several fabrics or webs have been impregnated, stacking of said fabrics and / or webs, said stacking being able to be carried out by pressing, or under vacuum, consolidation, preferably by drying and / or sintering, so as to form said matrix.

[0204] The manufacture of slip is well known to those skilled in the art. Slip is classically a suspension, for example of an aqueous base or an organic solvent, containing ceramic particles and / or ceramic particle precursors, i.e. compounds which are transformed into ceramic particles during the manufacture of CMC, and in particular by heating, and optionally dispersants, plasticizers, lubricants, and / or temporary binders.

[0205] The composition of the slip, the size distribution of ceramic particles or ceramic precursors, and the mineral content of the slip are adapted to the type of fibers and the shaping technique. For example, the slip can be applied around or onto the fibers, notably by direct lamination, infusion, injection, infiltration, or deposition, under atmospheric pressure, higher pressure, or vacuum, at ambient temperature or higher temperatures.

[0206] Consolidation can possibly be achieved in situ, that is to say when starting up the oven after application on the refractory part, for example and in particular on the cold face of a refractory block.

[0207] The sensor(s) can be rigidly fixed to the fabric or the sheet or to the stack of fabric(s) and / or sheet(s) before or after said drying and / or sintering.

[0208] The fabrics or layers can be stacked so that the threads of the different fabrics or layers all have essentially the same direction, or different directions, for example at 45°, depending in particular on the desired mechanical properties. The stacking can also be carried out on a rigid support having the profile of the cold face of the refractory part in order to obtain a support plate 310 with a profile close to that of said surface.

[0209] The perforated surface can be obtained by any technique known to those skilled in the art. In particular, holes can be created by drilling or cutting under a water jet, for example on the CMC obtained after sintering. Holes can also be created on the fiber assembly of the CMC, particularly on a textile, preferably a woven one, before coating with the matrix.

[0210] The shape of the instrumented plate is preferably adapted to fit the face of the refractory part that receives it. This shape can be given before hardening of the matrix, or after hardening of the matrix, for example by machining or deformation.

[0211] In one embodiment, the refractory part and / or the support plate, or even the instrumented plate, are positioned in their raw service position, that is, before being sintered. The refractory part is preferably in the form of concrete. The sintering of the refractory part and / or the support plate, or even the instrumented plate, is then carried out. in situ in the furnace. Preferably, the ceramic matrix of the CMC is formed by sintering during the heating of the furnace.

[0212] In one embodiment, the instrumented plate is fixed to a refractory block before the refractory block is assembled in the furnace. The invention thus relates to a refractory block to which an instrumented plate according to the invention is fixed before its assembly in the furnace.

[0213] The instrumented plate can be fixed to a cold surface.

[0214] It can also be placed between the facing sides of adjacent refractory blocks. figure 12 This illustrates an example in which an instrumented plate 300 1 according to the invention is arranged between the horizontal faces of two superimposed refractory blocks B1 and B2, and an instrumented plate 300 2 according to the invention is arranged between the vertical faces of two side-by-side refractory blocks B2 and B3. The instrumented plates 300 1 and 300 2 can be held in position by the compression exerted by the refractory blocks between which they extend.

[0215] Of course, the invention is not limited to the foregoing detailed description, which is provided for illustrative purposes only. It is also understood that the embodiments described are merely examples and could be modified, in particular by substituting technical equivalents, without departing from the scope of the invention.

[0216] In particular, the presence of holes through the support plate is especially advantageous, but the invention is not limited to this embodiment. Specifically, in addition to or alternatively to the holes, the support plate may be very thin, which advantageously also increases the deformability of the instrumented plate and limits its insulating effect. The thickness may, in particular, be greater than 1 mm and less than 20 mm, preferably less than 10 mm, or preferably less than 5 mm.

[0217] Furthermore, in certain applications, it may be useful for the CMC to contribute to the thermal insulation of the cold face of the refractory part. Preferably, it has a thermal conductivity of less than 2.0 W / m·K, preferably less than 1.8 W / m·K, preferably less than 1.5 W / m·K, preferably less than 1.3 W / m·K, preferably less than 1 W / m·K, preferably less than 0.9 W / m·K, preferably less than 0.8 W / m·K, preferably less than 0.7 W / m·K, preferably less than 0.6 W / m·K, preferably less than 0.5 W / m·K, between 20°C and 500°C, preferably between 20°C and 600°C, preferably between 20°C and 700°C, preferably between 20°C and 800°C, preferably between 20°C and 900°C, preferably between 20°C and 1000°C.

Claims

1. Instrumented plate intended for the monitoring of a refractory part of a furnace, the instrumented plate comprising: - a support plate (310) through which a plurality of orifices (304) pass and which is at least partially made of a material consisting of fibres interconnected by a ceramic matrix, referred to as "ceramic-matrix composite", or consisting of a precursor of said ceramic-matrix composite; - a sensor (312) borne by said support plate, a ceramic-matrix composite precursor being a material which is capable of transforming into said ceramic-matrix composite under the effect of heating.

2. Instrumented plate according to the preceding claim, wherein each of said orifices (304) has an equivalent diameter greater than 3 mm and / or less than 50 mm; and the percentage of perforation, equal to the ratio of - the cumulative surface area of the orifices (304), or "perforated surface area", to - the surface area of the support plate, said surface area including the perforated surface area, is greater than 5% and less than 95%, and the sensor (312) is a sensor for measuring an optical, electrical or acoustic signal, and the support plate (310) has a thickness of between 1 and 20 mm.

3. Instrumented plate according to the immediately preceding claim, wherein said percentage of perforation is greater than 50%.

4. Instrumented plate according to any one of the preceding claims, wherein the orifices (304) are evenly distributed in at least one "perforated" zone (302) of the support plate.

5. Instrumented plate according to the immediately preceding claim, wherein the support plate has several of said perforated zones (302) and at least one reinforcing zone (306) separating two of said perforated zones, the reinforcing zone having a width (1) greater than the largest dimension of said orifices.

6. Instrumented plate according to any one of the preceding claims, wherein the sensor (312) is - embedded within the ceramic-matrix composite or the precursor of said ceramic-matrix composite, or - integrated in the arrangement of fibres of the ceramic-matrix composite or of the precursor of said ceramic-matrix composite, or - accommodated in a recess (314, 316) formed or inserted in the ceramic-matrix composite or the precursor of said ceramic-matrix composite, or - attached to a large face of the support plate.

7. Instrumented plate according to any one of the preceding claims, wherein the ceramic-matrix composite or the ceramic-matrix composite precursor comprises a plurality of superposed textiles (310a, 310b), one or more identical or different sensors (312) being inserted between two of said textiles.

8. Instrumented plate according to any one of the preceding claims, wherein - the fibres represent more than 25% and less than 70% of the volume of the ceramic-matrix composite, and - the ceramic-matrix composite comprises, in percentage by mass, more than 80% of one or more of the following oxides or non-oxides: Al2O3, ZrO2, HfO2, Cr2O3, MgO, CaO, SiO2, SiC, Si3N4, SiAlON, AlN, Si2ON2, BN, B4C, silicon oxycarbide, MoSi2, and carbon C.

9. Instrumented plate according to any one of the preceding claims, wherein the ceramic-matrix composite has a resistance to compressive crushing of greater than 5 MPa, and / or a thermal conductivity between 20°C and 500°C of greater than 2.0 W.m-1.K-1.

10. Measuring device comprising an instrumented plate (300) according to any one of the preceding claims and a measuring appliance (320) communicating with the sensor (312) so as to receive and interpret a signal emitted by the sensor.

11. Furnace selected from a glass melting furnace, a metallurgical furnace, an incinerator, a gasifier, a combustion chamber intended for energy generation, and a gas reforming installation intended for the chemical industry, said furnace comprising: - a refractory part, and - a measuring device according to the immediately preceding claim, the instrumented plate (300) of the measuring device being disposed in contact with one face of the refractory part.

12. Furnace according to the immediately preceding claim, wherein the refractory part has a face intended to be at a temperature greater than 800°C, referred to as "hot face", and a face facing away from said hot face, referred to as "cold face" (F), the instrumented plate being disposed in contact with said cold face.

13. Furnace according to either one of the two immediately preceding claims, wherein the coefficient of thermal expansion of the ceramic-matrix composite is equal to that of the material of the refractory part plus or minus 20%.

14. Furnace according to any one of the three immediately preceding claims, wherein the instrumented plate (300) is attached to the refractory part so as to not exert thermomechanical stresses on the refractory part under the effect of a dimensional modification of the refractory part resulting from nominal operation of the furnace.

15. Furnace according to any one of the four immediately preceding claims, wherein the surface area of the instrumented plate represents more than 20% of the surface area of the face of the refractory part to which it is applied.

16. Furnace according to any one of the five immediately preceding claims, wherein the refractory part is selected from the following: - a throat lintel or block, - a soldier block, - a refractory brick or sidewall block, - a corner block, - a tuckstone, - a paving tile or pavement, - a crown brick or beam, - a tuyere surround brick or block, - a brick for a tapping hole or spout, - an electrode block, - an injector block, - a refractory spout-lip for a glass furnace, - a block for an injector, - a glass furnace throat, - a component for a heat exchanger of the furnace, - a refractory tile or plate for a boiler lining, - a protective shell for a heater tube for an incinerator, - a tile of an incinerator, - a ceramic component for a solar absorber, - a protective component or tile for a turbine combustion chamber, - a block or surround for a tuyere or a burner.

17. Furnace according to any one of the six immediately preceding claims, wherein the measuring device uses the signal it receives from the sensor to provide information relating to - the thickness of the refractory part, or - the mean temperature in the furnace, or - the physical state of the refractory part.