INSTRUMENTED OVEN PLATE

Abstract

An instrumented plate for monitoring a refractory section of a furnace, the instrumented plate comprising: - a support plate (310) through which a plurality of orifices (304) pass, and at least partially 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; - a sensor (312) carried by said support plate, a precursor of a ceramic matrix composite being a material capable of transforming into said ceramic matrix composite under the effect of heating. Abbreviated figure: 3

Description

Title of the invention: INSTRUMENTED OVEN PLATE 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, in particular 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 evaluate the thickness, the average temperature, or a 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 manufacture of molten products, for example for the manufacture of metallurgical or glass products, but also for the incineration of waste or the production of energy from fuels. For example, a reaction gas turbine is considered a furnace.

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

[0006] A metallurgical furnace can be an installation in which a metal precursor is reduced to obtain pig iron. A metallurgical furnace can also be a metalworking furnace or a remelting furnace. For example, a furnace can be a blast furnace for producing pig iron from iron ore or for remelting copper cathodes produced by another process, for example, to produce 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 the molten glass must also resist abrasion by the molten glass.

[0009] The composition of the refractory coating is particularly suited to the application targeted.

[0010] For example, the refractory lining in contact with molten glass or with 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 generally SiC-based.

[0012] In a blast furnace for iron production, refractory linings of SiC, cordinon, SiAlON, carbon or mullite are conventionally 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 by infrared thermography, but this is only possible in areas visually accessible by an infrared camera, which notably excludes certain parts of the oven lining. Furthermore, this solution generally does not allow for continuous monitoring.

[0015] Measurement devices allowing continuous, non-intrusive monitoring, i.e., without penetration into the furnace chamber, are known. 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 side wall blocks of the furnace chamber 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] However, prior art solutions allowing continuous monitoring pose problems - reliability, and in particular resistance to high temperatures, especially when the sensors include polymer parts, - disruption of the furnace's 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 coating, and - installation and maintenance, particularly in the event of sensor failure.

[0017] 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 disturbing the heat transfers through the refractory lining.

[0018] One object of the invention is to meet, at least partially, this need. Summary of the invention

[0019] 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 through 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.

[0020] As will be seen in more detail later in the description, the inventors discovered that a ceramic matrix composite plate constitutes a particularly well-suited sensor support for the intended applications. A ceramic matrix composite is highly resistant to high temperatures and effectively protects the sensor, particularly from mechanical shocks. It is easy to handle and install.

[0021] Furthermore, the inventors discovered that the presence of the orifices limits interactions with the refractory part. In particular, the presence of the instrumented plate on the refractory part 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 part on which the instrumented plate is immobilized is cooled, for example, by blowing air.

[0022] Furthermore, the inventors discovered that the presence of the orifices significantly reduces the transmission of mechanical stresses to the sensor. Reliability is therefore improved.

[0023] Finally, the instrumented plate can be shaped to fit this face of the refractory part, which improves the accuracy of the measurements taken.

[0024] The instrumented plate may also include, in particular, one or more of the ca- The following optional and preferred characteristics:

[0025] • at least one orifice, preferably each orifice, has an equivalent diameter greater than 3 mm, and / or less than 50 mm; • the percentage of adjournment, equal to the ratio of - the cumulative surface area of ​​the orifices, or "perforated surface area", on - the surface area of ​​the support plate, said surface area including the perforated surface, 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 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 holes, identical or different, preferably identical, are regularly distributed in at least one "perforated" area of ​​the support plate; • the support plate comprises several of said perforated areas and at least one reinforcement area, or "non-perforated area", separating two of said perforated areas, the reinforcement area having a width greater than the largest dimension of said openings; • the ceramic matrix composite or 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 fiber arrangement of the ceramic matrix composite or of the precursor of said ceramic matrix composite, for example as weft yarn, warp yarn or knitting yarn, or - housed in a recess or inserted into the ceramic matrix composite or into the precursor of said ceramic matrix composite, preferably in a recess on a large face of the backing 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 refractory adhesive, tape, staple or wire; • 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: Al2O3, ZrO2, HfO2, Cr2O3, MgO, CaO, SiO2, SiC, Si3N4, SiAlON, AIN, Si2ON2, BN, B4C, silicon oxycarbide, MoSi2, and carbon C; • The ceramic matrix composite exhibits a compressive strength greater than 10 MPa, and / or a thermal conductivity between 20°C and 500°C greater than 2.0 Wm*.K

[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, particularly 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

[0028] - the physical state of the refractory part, for example the presence of a trans phase formation or damage to the refractory part, for example scaling, internal cracking, phase change due to infiltration, or oxidation in the case of a refractory part into a non-oxide material.

[0029] A person skilled in the art knows how to choose the sensors appropriate for the information required.

[0030] The invention further relates to an oven comprising a measuring device according to the invention.

[0031] The oven may also include, in particular, one or more of the following optional and preferred features:

[0032] • the furnace is selected from 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 oven includes a refractory part and the instrumented plate is placed in contact with one face of the refractory part, preferably so as to fit said face; • the refractory part is a side wall or a floor of a furnace chamber or a block of said side wall or of said sole; • 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 oven; • 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 of the instrumented plate, which includes the surface of the orifices, represents more than 20% of the surface 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 ceramic matrix composite has a coefficient of thermal expansion 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 in the refractory part resulting from nominal operation of the furnace. Brief description of the figures

[0033] Other features and advantages of the invention will become apparent upon reading the detailed description that follows and upon examination of the accompanying drawing in which: - [Fig.l] [Fig.l] schematically represents half a cross-section of an example of a glass furnace; - [Fig.2] [Fig.2] schematically represents a half-section of an example of an induction metallurgical furnace; - [Fig.3] [Fig.3] schematically represents, seen from the front, a first example of an instrumented plate according to the invention; - [Fig.4] [Fig.4] schematically represents, from the front, a second example of instrumented plate according to the invention; - [Fig.5] [Fig.5] schematically represents, seen from the front, a third example of an instrumented plate according to the invention; - [Fig.6] [Fig.6] schematically represents, seen from the front, a fourth example of an instrumented plate according to the invention, in the service position; - [Fig.7] [Fig.7] schematically represents, seen from the front, a fifth example of an instrumented plate according to the invention; - [Fig.8] [Fig.8] schematically represents, in cross-section, an example of an instrumented plate according to the invention; - [Fig.9] [Fig.9] schematically represents, in cross-section, another example of an instrumented plate according to the invention; - [Fig. 10] [Fig. 10] schematically represents, in cross-section, yet another example of an instrumented plate according to the invention; - [Fig. 11] [Fig. 11] illustrates the bending deformability of an instrumented plate in a preferred embodiment of the invention; - [Fig. 12] [Fig. 12] illustrates a positioning of an instrumented plate according to the invention between refractory blocks of a furnace; - [Fig. 13] [Fig. 13] represents, in vertical section, an embodiment in which two superimposed blocks are inserted between which an instrumented plate is inserted.

[0034] Identical references are used to designate identical or similar parts. Definitions

[0035] The term "refractory part" refers to a furnace component made of a refractory material. A refractory part may be a single block, but also an assembly of blocks, for example, a side wall of a furnace, or a hearth, particularly one formed by casting. A refractory part is typically made of a molten or sintered material. Typically, an insulating layer covers the cold side of the refractory part to limit heat transfer.

[0036] Conventionally, when the refractory part has a hot face, its "thickness" is its dimension measured along a direction perpendicular to its hot face. For example, for a side block of a tank in contact with molten glass or metal, the thickness is measured along a substantially horizontal direction directed towards the molten glass or metal bath. For a hearth, the thickness is measured along a vertical direction.

[0037] The "hot face" is the face of a refractory part that is exposed to a space in the furnace that is at more than 800°C, for example containing molten glass or metal 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 that extends above the molten glass or metal. The hot face is thus the face of the refractory material that is subjected, or is 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 described as the "hot face."

[0038] 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.

[0039] A "cold face" is a surface of the refractory portion 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 portion. The cold face opposite the hot face is the face furthest from said space. Conventionally, the cold face opposite the hot face is the face that, during operation, is subjected or is intended to be subjected to the lowest temperatures. The cold face may be parallel to the hot face.

[0040] 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.

[0041] The term "plate" conventionally refers to a part having two large faces that are substantially parallel to each other and having a small thickness relative to the surface area of ​​said large face, 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 m1, preferably less than 1 / 1000 m*, preferably less than 1 / 5000 m1, preferably less than 1 / 10000 m1.

[0042] The "surface" of a plate is the area inside the perimeter of the plate. The surface of the plate therefore includes the surface defined by the material of the plate and the surface of the orifices that pass through the plate.

[0043] The thickness of the instrumented plate is its dimension measured perpendicularly to the large face of the instrumented plate intended to be positioned or positioned against the refractory part.

[0044] An orifice that passes through a plate is an orifice that has first and second openings that lead to the first and second large faces of the plate. An orifice is preferably straight and extends preferably perpendicularly to the large faces of the plate. The "surface" 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.

[0045] By "perforated surface", we mean the cumulative surface of all the surfaces of the orifices.

[0046] The percentage of perforation of a perforation area or of the instrumented plate is the ratio of the perforation area of ​​the orifices of said perforation area or of said instrumented plate, respectively, to the area of ​​said perforation area or of said instrumented plate, respectively.

[0047] The "equivalent diameter" of an orifice is the diameter of a disk with the same surface area as that orifice.

[0048] By "molten product", often called "electro-fused", is meant 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.

[0049] By "sintered product" is meant a product obtained by mixing suitable raw materials and then shaping this mixture raw and cooking the resulting raw part at a temperature and for a time sufficient to achieve sintering of this raw part, said cooking being able to be carried out in situ during use.

[0050] By "Ceramic Matrix Composite," or "CMC," we classically mean 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 is to be placed, in particular according to the conditions of temperature, corrosion, thermal cycling, expansion, and according to the nature of the refractory part to be lined.

[0051] The arrangement of the fibers, which constitutes 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 to it. 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 filament placement is well suited for large, complex shapes.

[0052] A “ceramic matrix composite precursor” is a material capable of transforming into said ceramic matrix composite under the effect of heating, preferably at more than 600°C, preferably at more than 700°C, preferably under the effect of sintering.

[0053] The fibers are classically in the form of a textile. The CMC can then be described as a "ceramic matrix textile".

[0054] A textile can be: - an organized two-dimensional structure of fibers or threads, including a knit, a braid, a fabric, or - a random two-dimensional structure of fibers or threads, this random structure not being preferred.

[0055] 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.

[0056] 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.

[0057] A “yarn” is an assembly of fibers which, in cross-section, comprises more than 10 and preferably less than 500,000 fibers, and whose length is greater than 5 times the diameter.

[0058] The term "ceramic" means a product that is neither metallic nor organic. In the context of the present invention, carbon is considered to be a ceramic product.

[0059] By "skin", we classically mean the peripheral region of a molten block, formed from the molten material that was less than 5 millimeters (mm) from the mold wall when it solidified.

[0060] By "machining" is meant a grinding operation by which the surface of a refractory part is machined in order to obtain a precise surface geometry.

[0061] For the sake of clarity, the chemical formulas of the oxides are used to designate the contents of these oxides in a composition. For example, "ZrO2", "SiO2" or "Al12O3" designate the contents of these oxides and "zirconia", "silica" and "alumina" are used to designate phases of these oxides consisting of ZrO2, SiO2 and Al12O3, respectively.

[0062] Unless otherwise stated, all oxide contents are mass percentages on an oxide basis. 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.

[0063] A transverse plane is a plane perpendicular to the direction of the length.

[0064] 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°.

[0065] “Contain” or “include” or “present” should be interpreted as in a non-exhaustive manner. Detailed description Oven - refractory section

[0066] 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.

[0067] The invention preferably relates to a glass furnace. However, the invention is not limited to this preferred application.

[0068] Fig. 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 distinguished.

[0069] The tank 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 tank blocks which extend over the entire height of the tank, up to an upper edge 25.

[0070] A thermally insulating layer, not shown in [Fig. 1], is conventionally placed against the cold face of the side wall. In particular, the insulating layer can encircle the side wall of the glass melting tank of the furnace.

[0071] The superstructure 16 conventionally 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.

[0072] The metal structure 14, conventionally made of cast iron, surrounds the lateral wall 22 of the tank externally. It supports the weight of the superstructure 16.

[0073] The intermediate layer 18 comprises, and preferably consists of, pieces with a basic nose 20 (“tuckstones” in English).

[0074] 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.

[0075] The refractory part may be in particular the vault, the side wall of the superstructure, the intermediate stratum, the side wall of the tank, the floor, a block of the vault, of the side wall of the superstructure, of the intermediate stratum, of the side wall of the tank, or of the floor.

[0076] The invention also relates to a metallurgical furnace. In particular, [Fig. 2] schematically represents, in cross-section, a crucible of an induction furnace, for example for dephosphorization. This crucible has a side wall 110 extending substantially vertically from a bottom 112.

[0077] The side wall 110 of the crucible conventionally 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 120 electrical insulation; - a refractory coating 122 defining the inner surface 128 of the crucible.

[0078] The base 112 conventionally 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.

[0079] 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 involved. The temperature is generally below 1700°C.

[0080] The refractory part can 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'.

[0081] The refractory part can be a part of the furnace that is not in contact with the inside of the furnace enclosure.

[0082] 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 of a glass furnace, an injector block, a glass furnace throat, a part of a furnace heat exchanger, in particular a heat exchanger tube, a plate or a refractory tile, 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.

[0083] Preferably, the refractory part is rigid, such as a block or an assembly of blocks, preferably consolidated, and in particular sintered or melted.

[0084] The invention is particularly well suited to a refractory section having 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 being detectable with conventional furnace monitoring tools.

[0085] 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 higher than 1800°C.

[0086] 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.

[0087] The chemical composition of the refractory part can be a composition known for conventional coatings, in the intended application.

[0088] The refractory part is preferably formed of a refractory block or an assembly of several refractory blocks.

[0089] 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.

[0090] The refractory part is preferably made up of more than 95%, more than 97%, more than 99%, more than 99.5%, more than 99.9% of its mass, of refractory oxides and / or non-oxides.

[0091] In one embodiment, the refractory part has a chemical composition, in mass percentage on the basis of oxides, such that A12O3 + ZrO2 + SiO2+ Cr2O3 > 80.0%.

[0092] 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.

[0093] In one embodiment, the refractory part is a molten product and may further comprise one or more of the following optional features:

[0094] - at least a part, preferably all of the surfaces of the refractory part intended to be exposed to the environment inside the furnace have a skin microstructure. In particular, preferably at least a part, preferably all of the vessel surface and / or the upper transition surface have a skin microstructure; - the skin microstructure surface has 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;

[0095] Obtaining a skin microstructure on the surface of a molten part, i.e., a molten product, does not present any particular difficulty to those skilled in the art. In particular, those skilled in the art know that a microstructure can be made finer on the surface by increasing the solidification rate of the molten material.

[0096] When the molten material is poured into the mold, the mold properties and temperature can be adjusted to ensure sufficiently rapid cooling to obtain 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 a machining operation, a skin microstructure is thus obtained on the surfaces of the refractory portion that have not been machined.

[0097] Limited machining (surfacing) however allows a skin microstructure to be retained.

[0098] Of course, the composition, dimensions, shapes and microstructures described above are not limiting.

[0099] 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

[0100] The instrumented plate is an "instrument", in the form of a thin piece or layer, intended for capturing measurements.

[0101] Figures 3 to 8 represent examples of instrumented plate 300.

[0102] 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.

[0103] As illustrated in [Fig.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.

[0104] The portion of the face of the refractory part in contact with the instrumented plate 300 may be flat, for example defined by the throat of a glass furnace or a gas turbine tile. It may be a straight or curved flat surface, for example being the face of a nose brick in the particular case of a glass furnace. Preferably, it is flat.

[0105] 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.

[0106] Preferably, the instrumented plate 300 has, between the large faces Gi and G2, an average thickness e (see [Fig. 8]) that is preferably constant, 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, or greater than 10 mm. A thickness between 1 and 20 mm, preferably between 2 and 10 mm is preferred, in order to be able to fit easily between the refractory part and the insulating rear part or the outer casing of the oven while allowing sufficient mechanical hold of the instrumented plate 300.

[0107] 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.

[0108] 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.

[0109] Preferably, the instrumented plate 300 is prefabricated, that is to say manufactured before being applied against the refractory part.

[0110] The instrumented plate 300 preferably has sufficient rigidity to be self-supporting, i.e., to retain its shape when handled at ambient temperature (20°C). In the operating position, the sensor is thus effectively held in position.

[0111] 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.

[0112] For example, it can be arranged, or even fixed, in a recess provided on this face, for example in the embodiment in which it is arranged between two adjacent blocks, as illustrated in Figures 12 and 13.

[0113] In particular, the instrumented plate 300 may have the shape of a flat plate, with several flat sides, or cylindrical.

[0114] The rigidity of the instrumented plate 300 preferably allows it to be flexed by hand, as shown in [Fig. 11]. Advantageously, it can thus better conform to the shape of the face of the refractory part which receives it.

[0115] In one embodiment, the instrumented plate 300 is in the form of a roll before being applied against the refractory part.

[0116] According to the invention, the instrumented plate 300 has a perforated area 302, that is to say, traversed by a plurality of orifices 304.

[0117] The perforation significantly limits the influence of the instrumented plate on the functioning of the refractory part, and in particular the impact of the instrumented plate on heat transfer. The perforation also reduces the thermomechanical stresses that the instrumented plate exerts on the refractory part.

[0118] The percentage of perforation of a perforation area, preferably of any perforation 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%.

[0119] Fig. 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.

[0120] The shape and distribution of the orifices 304 can take different configurations depending on the dimensions of the refractory part.

[0121] In a perforated area, preferably in each perforated area 302, the orifices 304 are preferably regularly distributed.

[0122] In an openwork area 302, preferably in each openwork area, the orifices may have identical or different shapes and / or dimensions, preferably identical.

[0123] The orifices 304 preferably have an oval, round shape, as illustrated in [Fig.6], or polygonal, preferably rectangular, square or diamond-shaped, as illustrated in Figures 3 and 4.

[0124] 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.

[0125] Preferably, to minimize the impact on heat transfer, the surface area of ​​each orifice 304 is between 4 mm2 and 1000 cm2.

[0126] 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 considered. A variation in cross-section advantageously allows for the local definition of mechanical resistance properties, for example, how the instrumented plate deforms.

[0127] In a perforated area 302, preferably in each perforated area, the orifices 304 are preferably regularly distributed. 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.

[0128] An openwork area 302, preferably each openwork area, preferably has the general shape of a grid, a mesh or a trellis.

[0129] In one embodiment, the instrumented plate 300 comprises several zones perforated 302, preferably regularly distributed on the instrumented plate, separated by areas without perforations, called "reinforcement areas" 306, as illustrated in [Fig.4]. In one embodiment, all the reinforcement areas form a regular pattern, for example a frame or a grid.

[0130] The reinforcement zones contribute advantageously to the mechanical resistance of the instrumented plate.

[0131] The width l of a reinforcement zone, that is to say the smallest distance between the two perforated 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 one time, preferably greater than 2 times, preferably greater than 3 times, and / or preferably less than 20 times the largest dimension of the orifices of the perforated areas it separates.

[0132] Preferably, the thickness of the reinforcement zones 306 is identical to that of the openwork zones.

[0133] The instrumented plate 300 can be kept in contact with the refractory part by any means known in the prior art.

[0134] The face of the refractory part which receives the instrumented plate can be grooved or machined so as to provide a housing or a recess allowing the instrumented plate to be fixed, for example by clipping or pinching.

[0135] 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.

[0136] Preferably, it is not fixed over its entire surface, but by fixing points and / or fixing lines.

[0137] 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.

[0138] In one embodiment, the instrumented plate 300 is immobilized on the face which receives it by complementarity of form with said face.

[0139] 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.

[0140] Preferably, the powders are alumina and / or silica and / or mullite powders. Preferably, the binders are selected from colloidal silica, sodium silicate, organic resins, organic adhesives, and mixtures thereof. The adhesive used may also be a commercial adhesive such as Fixwool FX adhesives from Unifrax.

[0141] In one embodiment, the instrumented plate 300 is manufactured, in particular sintered, in situ, i.e. on the refractory part. The instrumented plate 300 can then be considered as a "layer" covering the face of the refractory part that receives it, i.e. against which it extends.

[0142] 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. CMC

[0143] The support plate 310 preferably comprises a ceramic matrix composite, or "CMC", or a CMC precursor.

[0144] A person skilled in the art knows how to adapt a CMC precursor according to the desired CMC. Only the CMC is therefore described in detail below.

[0145] The support plate 310 defines the general shape of the instrumented plate and serves as a support for one or more sensors.

[0146] A CMC has proven to be particularly resistant to thermal degradation. A CMC also exhibits good resistance to corrosion by sodium vapors.

[0147] Preferably, the CMC is sintered, conventionally under air, at atmospheric pressure.

[0148] Preferably, the CMC has an open porosity, measured by imbibition, according to the principle of Archimedes' buoyancy, greater than 25%, preferably greater than 30% and less than 45%, preferably less than 35%.

[0149] 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.

[0150] In particular, when the instrumented plate is fixed to the cold side of the refractory part, for example by bonding or mechanical fastening, for example 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 part material by more than 20%. The coefficient of thermal expansion of the CMC can be adjusted by techniques well known to those skilled in the art, in particular 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 10⁶ mK⁻¹, 8.0 x 10⁶ mK⁻¹ for alumina, 4.5 x 10⁶ mK⁻¹ for SiC, and less than 1.0 x 10⁶ mK⁻¹ for carbon.

[0151] 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 Wm'.K', between 20°C and 500°C.

[0152] In one embodiment, the CMC has, between 20°C and 500°C, a thermal conductivity greater than 2.0 Wm'.K', preferably greater than 5.0 Wm'.K' or even greater than 10 Wm'.K or even greater than 50 Wm'.K'.

[0153] Simple tests allow, in order to obtain a specific coefficient of thermal expansion and / or a specific thermal conductivity, the quantities of silica, alumina, SiC, and carbon fibers and / or the quantity of silica, alumina, SiC, and carbon matrix to be determined. For example, the thermal conductivity of CMC can be adjusted by combining fibers, for example thermally conductive SiC or graphite fibers, with a more insulating matrix, for example alumina, or by combining a thermally conductive matrix, for example SiC, with more insulating fibers such as alumina or silica fibers.

[0154] Preferably, the CMC has a 3-point bending strength, measured according to ASTM C1341-13, greater than 3 MPa, preferably greater than 6 MPa, preferably greater than 10 MPa. Advantageously, its mechanical strength, in particular its impact resistance, is improved.

[0155] Preferably, the CMC, particularly in the form of a ceramic matrix textile, exhibits very high compressive strength, for example measured as described below, greater than 5 MPa, preferably greater than 10 MPa, which improves the stability of the sensor. This compressive strength is notably greater than that of layers made of fiber mats (insulating mats).

[0156] To measure the compressive strength of a layer of thickness e, a sample with dimensions of 50 x 50 x 10 mm³ is extracted, the 10 mm dimension being along the direction of the thickness e. A load is then applied, at room temperature, over the entire 50 x 50 mm² surface of the sample, along the direction of the thickness, with a displacement rate of 0.1 mm / min. The load is increased until the sample thickness is reduced by half (i.e., by 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).

[0157] 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.

[0158] The CMC is preferably made up of one or more of the oxides or non-oxides The following: Al2O3, ZrO2, HfO2, Cr2O3, MgO, CaO, SiO2, SiC, Si3N4, SiAlON, AIN, Si2ON2, BN, B4C, silicon oxycarbide, MoSi2, carbon C, particularly in the form of amorphous carbon, graphite or graphene. It is then particularly resistant to thermal degradation.

[0159] Preferably, the CMC is made up of more than 90% of its mass, more preferably more than 95% of its mass, more preferably more than 98% of its mass, more preferably more than 99% of its mass, more preferably more than 99.5% of its mass, of oxides.

[0160] In particular, preferably, the sum of the contents of A12O3, SiO2, ZrO2, CaO, Na2O, MgO, K2O, TiO2, Fe2O3, HfO2, Cr2O3, P2O5 and Y2O3 or "A12O3 + SiO2 + ZrO2 + CaO + Na2O + MgO + K2O + TiO2 + Fe2O3 + HfO2 + Cr2O3 + P2O5 + Y2O3", 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%.

[0161] In one embodiment, the CMC has a chemical composition, expressed as a mass percentage on the basis of 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 on the basis of the oxides, such that the total content of Al2O3 + SiO2 + ZrO2 + CaO + Na2O + MgO + K2O + TiO2 + Fe2O3 + HfO2, expressed as a mass percentage on the basis of 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 A12O3 + SiO2 + ZrO2 + CaO + HfO2 is greater than 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%.

[0162] In one embodiment, the CMC has a chemical composition, in mass percentage on the basis of the oxides, such that A12O3 + SiO2 > 80%, preferably greater than 85%, preferably greater than 90%, or even greater than 95%.

[0163] 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%, - A12O3: 32% - 52%, - oxide species other than Al2O3 and SiO2: < 5%, preferably < 4%, preferably < 3%, preferably < 2%. CMC Fibers

[0164] 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 taking into account its porosity, the remaining 100% being made up of the ceramic matrix binding the said fibers together.

[0165] 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.

[0166] The fibers are preferably grouped in the form of yarns. Each yarn preferably comprises more than 10, more preferably more than 50, more preferably more than 100 fibers, and more 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.

[0167] The CMC fibers preferably comprise 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.

[0168] 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.

[0169] 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 Al2O3 and / or SiO2 and / or ZrO2, as a percentage by mass on the basis of the oxides.

[0170] The fibres may also be, at least in part, made of a non-oxide material, for example SiC, another carbide, a nitride or an oxynitride.

[0171] 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

[0172] The ceramic matrix, or “binding phase”, of the CMC may comprise, by mass percentage, more than 80%, more than 90%, more than 95%, or even substantially 100% of one or several compound(s) chosen from the group formed by SiC a or [3, silicon oxycarbide, carbon C, in particular in the form of amorphous carbon, graphite or graphene, Si3N4, AIN, silicon oxynitrides including SiAlON and Si2ON2, boron nitride BN, boron carbide B4C, and molybdenum disilicide MoSi2.

[0173] 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.

[0174] 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 Al2O3, ZrO2, Cr2O3, MgO, CaO and SiO2.

[0175] 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 based on the oxides in the matrix, is less than 3%, preferably less than 2%, preferably less than 1%.

[0176] In one embodiment, the silica of the matrix is ​​amorphous. Sensor

[0177] The instrumented plate includes one or more sensors 312.

[0178] In Figures 3 and 6 to 9, the sensors have been represented by dashed lines. They have not been represented in the other figures.

[0179] The sensor 312 can be any known sensor. It allows 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.

[0180] 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, described by WO2017 / 009256.

[0181] According to a particularly advantageous embodiment, the sensor 312 takes the form of a wire or an assembly of wires, fixed to or incorporated into the support plate 310, preferably incorporated into the CMC of the plate. support 310.

[0182] According to a first particular embodiment, as illustrated in [Fig. 10], the sensor is fixed to the support plate 310 by means of an interface layer. The interface layer may be, particularly if the temperature of the face of the refractory part 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 interfacing 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. Kôhler, Jena. "Inorganic High-Temperature Adhesives - Applications and Limits" published in "SchweiBen und Schneiden 2000 Vortrage der gleichnamigen GroBen SchweiBtechnischen 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 its quantity of organic materials (thermosetting polymers, thermoplastics, or crosslinking elastomers), accelerators, retarders, or fluidizers. It is also possible to fill it, in particular with an elastomer filling or one made of polymer or mineral fibers.

[0183] 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, or Inconel or even platinum wire may be used, depending on the maximum temperature reached by the face of the refractory part that receives the instrumented plate.

[0184] According to a third embodiment, the sensor, whether wired or wireless, is integrated within the support plate 310, in particular within the CMC of the support plate 310. As illustrated in [Fig. 9], the instrumented plate 300 may, 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 may be joined to each other by staples or during sintering to form the CMC. They may, by to form a housing for receiving 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.

[0185] Figure 7 illustrates 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.

[0186] 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.

[0187] 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.

[0188] 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 preferably being 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.

[0189] 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.

[0190] 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, said woven or said braid.

[0191] The assembly formed by the CMC's knit, woven, or braided material on the one hand and the sensor on the other is then partially or completely covered with the ceramic matrix. Advantageously, the matrix thus provides a protective function for the sensor. The sensor is selected to withstand the coating and firing process of the ceramic matrix. This embodiment is particularly suitable for wire or ceramic sensors.

[0192] The incorporation of a wired sensor into the support plate can be carried out according to a preferred plane, preferably in a preferred direction or according to a particular pattern.

[0193] The instrumented plate may include several sensors, for example: - several temperature sensors, for example two different fiber arrays optics; - a temperature sensor and a deformation sensor.

[0194] The sensors can all be arranged between the same two textiles, or between different textiles.

[0195] Measuring device

[0196] The measuring device 320, which has only been shown in [Fig.3], is intended for the control of the sensor 312, in particular for receiving and interpreting the signal emitted by the sensor.

[0197] 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.

[0198] Preferably, the cables and connecting terminals are made of a refractory metal resistant to over 400°C, for example platinum. A refractory and conductive platinum-based adhesive can be used to improve electrical contacts.

[0199] 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.

[0200] The measuring device conventionally comprises 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.

[0201] Any conventional measuring device may be used. In particular, the processing, analysis and recording of the electrical property measured by the sensor and its variations may employ amplification, filtering, multiplexing and digitization methods known to those skilled in the art in the field of sensors.

[0202] Communication between the sensor and the measuring device can be carried out wired or wirelessly, for example by wifi or Bluetooth®.

[0203] Preferably, the measuring device is programmed to record the sensor signal at regular time intervals. Heating and cooling

[0204] 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 face, and / or the instrumented plate. Preferably, the instrumented plate is arranged between the cold face of the refractory part and the cooling system. cooling.

[0205] Preferably, the cooling system is mainly intended to cool the cold face of the refractory part, the sensor being protected by the ceramic matrix.

[0206] The furnace may also include a heating device, for example a heating element. Such heating can be useful for limiting thermal shock and temperature gradients in the thickness of the refractory part. Manufacturing

[0207] The refractory part and the instrumented plate can be manufactured by all conventional manufacturing processes.

[0208] The process for manufacturing the instrumented plate may in particular include the following steps: - arrangement, around the fibers, of a slip capable of forming a ceramic matrix after consolidation, for example by impregnation of one or more fabrics or sheets, preferably fabrics or sheets of yarns, preferably ceramic yarns; - if several fabrics or sheets have been impregnated, stacking of said fabrics and / or sheets, said stacking being possible by pressing, or under vacuum, - consolidation, preferably by drying and / or sintering, so as to form said matrix.

[0209] 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 that transform into ceramic particles during the manufacture of CMC, and in particular during heating, and - optionally dispersants, plasticizers, lubricants, and / or temporary binders.

[0210] 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 deposited around or on the fibers, particularly by direct lamination, infusion, injection, infiltration, or deposition, under atmospheric pressure or higher pressure or vacuum, at ambient temperature or higher temperature.

[0211] Consolidation may possibly be carried out in situ, i.e. during the start-up of the furnace after application on the refractory part, for example and in particular on the cold face of a refractory block.

[0212] The sensor(s) may 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.

[0213] Fabrics or tablecloths 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 surface of the refractory part in order to obtain a support plate 310 with a profile close to that of said surface.

[0214] The perforated surface can be obtained by any technique known to those skilled in the art. In particular, holes can be made by drilling or cutting under water jet, for example on the CMC obtained after sintering. Holes can also be made on the fiber assembly of the CMC, in particular on a textile, preferably a woven one, before coating with the matrix.

[0215] 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 by deformation.

[0216] In one embodiment, the refractory part and / or the instrumented plate are arranged in the raw service position, i.e., before being sintered. The refractory part is preferably in the form of concrete. The sintering of the refractory part and / or 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 furnace heating process.

[0217] 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.

[0218] The instrumented plate can be fixed to a cold surface.

[0219] It can also be arranged between opposite faces of adjacent refractory blocks. Figure 12 illustrates an example in which an instrumented plate 300i according to the invention is arranged between the horizontal faces of two superimposed refractory blocks B1 and B2, and an instrumented plate 3002 according to the invention is arranged between the vertical faces of two side-by-side refractory blocks B2 and B3. The instrumented plates 300i and 3002 can be held in position by the compression exerted by the refractory blocks between which they extend.

[0220] 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 only examples and could be modified, in particular by substituting technical equivalents, without departing from the scope of the invention.

[0221] In particular, the presence of the holes passing through the support plate is particularly advantageous, but the invention is not limited to this embodiment. In particular, in addition to or alternatively to the orifices, the support plate can be very thin, which advantageously also increases the deformability of the instrumented plate and limits its insulating effect. The thickness can be greater than 1 mm and less than 20 mm, preferably less than 10 mm, or preferably less than 5 mm.

[0222] Furthermore, in certain applications, it may be useful for the CMC to participate in 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. between 20°C and 1000°C.

Claims

Demands

1. Instrumented plate for monitoring a refractory part of a furnace, the instrumented plate comprising: - a support plate (310) through which a plurality of orifices (304) pass and 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; - a sensor (312) carried by said support plate, a precursor of ceramic matrix composite being a material capable of transforming into said ceramic matrix composite under the effect of heating.

2. Instrumented plate according to the preceding claim, wherein each said orifice (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 area of ​​the orifices (304), or "perforated area", to - the area of ​​the support plate, said area including the perforated 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 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 regularly distributed in at least one "perforated" area (302) of the support plate.

5. Instrumented plate according to the immediately preceding claim, wherein the support plate has several said perforated zones (302) and at least one reinforcement zone (306) separating two said perforated zones, the reinforcement zone having a width (Z) 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 into the arrangement of the fibers of the ceramic matrix composite or of the precursor of said ceramic matrix composite, or - housed in a housing (314, 316) formed or inserted in the ceramic matrix composite or the precursor of said ceramic matrix composite, or - fixed 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 ceramic matrix composite precursor comprises a plurality of superimposed textiles (310a,310b), one or more sensors (312), identical or different, being inserted between two said textiles.

8. Instrumented plate according to any one of the preceding claims, wherein - the fibers represent more than 25% and less than 70% of the volume of the ceramic matrix composite, and - the ceramic matrix composite comprises, by mass percentage, more than 80% of one or more of the following oxides or non-oxides: Al2O3, ZrO2, HfO2, Cr2O3, MgO, CaO, SiO2, SiC, Si3N4, SiAlON, AIN, 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 compressive crush strength greater than 10 MPa, and / or a thermal conductivity between 20°C and 500°C greater than 2.0 Wm⁻¹K⁻¹

10. • IV. Measuring device comprising an instrumented plate (300) according to any one of the preceding claims and a measuring apparatus (320) in communication 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 for energy production, and a gas reforming plant 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 a face of the refractory part.

12. Oven according to the immediately preceding claim, wherein the refractory part comprises a face intended to be at a temperature sufficient for above 800°C, called the "hot side" and a side away from said hot side, called the "cold side" (F), the instrumented plate being placed in contact with said cold side.

13. Oven according to any one of the two immediately preceding claims, wherein the coefficient of thermal expansion of the ceramic matrix composite is equal to that of the refractory part material plus or minus 20% and / or wherein the ceramic matrix composite has a coefficient of thermal expansion equal to that of the refractory part material plus or minus 20%.

14. Oven according to any one of the three immediately preceding claims, wherein the instrumented plate (300) is fixed to 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 resulting from nominal operation of the oven.

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

16. A furnace according to any one of the five immediately preceding claims, wherein the refractory part is selected from: - a throat block or lintel, - a tank block, - a wall or side brick or block, - a corner or angle block, a nose brick, - a floor block or slab, - a vault brick or springer, - a tuyere surround brick or block, - a pouring hole or channel brick, - an electrode holder block, - an injector block, - a refractory nozzle part of a glass furnace, - an injector block, - a glass furnace throat, - a part of a furnace heat exchanger, - a refractory plate or tile of a boiler lining, - a heater tube protective shell of an incinerator, - a tile from an incinerator, - a ceramic component of a solar absorber, - a tile or protective part of a combustion turbine chamber.

17. Oven 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 average temperature in the oven, or - the physical state of the refractory part.

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