METHOD FOR REPAIRING A GLASS MELTING FURNACE

Abstract

A method for repairing a repairable area (30) extending over the intrados (29) of a side wall (22, 26) of the enclosure of a glass melting furnace (10), said method comprising the following steps: a) installing an inner formwork (32) comprising a flexible textile element (50) and a stiffening element (52) for stiffening the inner formwork, so as to create a mold (36) around the area to be repaired; b) filling the mold with a repair product (41) to a service configuration; the method wherein, in step a), the textile element is rigidly fixed to the furnace, the textile element being shaped to exert, in the service configuration, a force (R) on the stiffening element opposing the thrust (P) exerted by the repair product on the stiffening element. Abbreviated figure: 10

Description

Title of the invention: METHOD FOR REPAIRING A GLASS MELTING FURNACE technical field

[0001] The present invention relates to a method for repairing a glass melting furnace. It also relates to a formwork for implementing this method. Prior art

[0002] Fig. 1 schematically represents half a cross-section of a glass melting furnace 10. In particular, a tank 12, a metal structure 14 and a superstructure 16 are distinguished.

[0003] The tank 12, intended to contain the molten glass, has a vertical side wall 22 and a base 24. The side wall 22 conventionally comprises lateral tank blocks which extend over the entire height of the tank, up to an upper edge 25. The base of the tank defines the substantially horizontal bottom of the tank and the substantially vertical side wall surrounds the bottom.

[0004] The part of the furnace that covers the vessel and closes the enclosure is conventionally called the "superstructure" 16 of a glass melting furnace. It typically comprises tuckstones (if present), walls, and the vault. It does not come into contact with the molten glass. It typically comprises, at its base, an intermediate layer 18 on which it rests on the metal structure, a side wall 26 resting on the intermediate layer, and a vault 28. In a gas furnace, the burners, not shown, are arranged in the side wall 26. The intermediate layer 18 comprises, and preferably is made of, tuckstones 20.

[0005] The tank and the superstructure together constitute the furnace enclosure.

[0006] In the remainder of this description and unless otherwise indicated, the term "side wall" refers to the side wall 22 of the tank and / or the side wall 26 of the superstructure. The side wall defines an inner surface of the enclosure, or "intrados" 29, and a surface opposite the intrados, called the "extrados" 31. The side wall conventionally includes not only the refractory blocks that define the intrados, but also insulation and / or cladding pieces and / or a metal framework surrounding the assembly of these blocks.

[0007] The "interior" of the oven is delimited by the intrados 29.

[0008] Molten glass, vapors and condensate are highly corrosive. Refractory parts undergo significant wear.

[0009] The refractory pieces used, which are typically in the form of blocks or slabs, are cast and molded pieces, or pieces obtained by sintering. They are The materials are chosen based on their location, ensuring they can withstand local stresses and provide the furnace with a satisfactory lifespan. The selection is also guided by the need to avoid defects that would render the glass unusable and reduce production yields.

[0010] In order to increase the lifespan of the furnace, the glassmaker is required to carry out repairs.

[0011] The repair can be carried out after draining the glass and cooling the furnace. A person can then enter the furnace to perform the repair. Alternatively, the repair can be a so-called "hot" repair, preferably at over 300°C, in which case a person cannot enter the furnace to perform the repair.

[0012] A repair consists of filling, with a repair product, a void resulting from the wear of the furnace, that is to say, fixing a repair product in an area initially occupied by a refractory material and which has disappeared due to wear. This area is called the "area to be repaired".

[0013] A repairable area 30 may, in particular, result from wear on the side wall 22 of the tank and / or the side wall 26 of the superstructure. To repair the side wall, it is necessary to retain the repair product to prevent it from flowing out by gravity. This problem generally does not arise when repairing the hearth.

[0014] The area to be repaired may sometimes extend through the furnace chamber, creating a fluid connection between the inside and outside of the furnace. Such a through-hole can, in particular, lead to leaks of molten glass into the furnace. These leaks are dangerous and can cause the furnace to shut down.

[0015] To repair the hot furnace, as illustrated in EP 0 739 861, a formwork is typically constructed to create, using the refractory component(s), a mold capable of retaining the repair material before it hardens. The area to be repaired is then partially delimited by one or more refractory components of the furnace and partially by the formwork.

[0016] The casing includes a portion inside a furnace, where wear has occurred. It may also include a portion outside the furnace when wear has led to a penetration through the furnace chamber, in order to prevent the repair product from escaping outside the furnace. The outer portion of the casing is typically a veneer. For clarity, the portions of the casing inside and outside the furnace are referred to as the "inner casing" and "outer casing," respectively.

[0017] Figure 2 illustrates an example of conventional internal formwork 32i. This formwork comprises three adjacent panels 35i and 352 and 353 held in position by means of metal clamps 39, shoring bricks 43 and cooled tubes 45.

[0018] A "hot" repair is a repair that is carried out at a temperature typically above 300°C. Hot repair therefore only requires a reduction Limited temperature reduction, known as "de-soaking," or even no temperature reduction at all, significantly limits the duration of kiln downtime. However, the introduction of formwork elements into the kiln can lead to their degradation due to thermal shock.

[0019] Furthermore, particularly for hot repairs, the interior of a furnace is difficult to access, making it challenging to construct the internal formwork for certain areas requiring repair. Specifically, inserting the internal formwork elements may necessitate creating passages through the furnace chamber. Moreover, during a hot repair, no operator can enter the furnace. Therefore, the internal formwork installation must sometimes be carried out remotely from the area to be repaired. The size and weight of the internal formwork elements can thus significantly slow down the formwork construction process.

[0020] These constraints also make it very difficult to produce an internal formwork of complex shape, in particular when the area to be repaired protrudes towards the inside of the oven.

[0021] After the formwork is installed, the mold is filled with repair material, typically using a pump. During a hot repair, the repair material experiences a sudden temperature increase upon entering the mold, resulting in a reduction of its flowability. Therefore, it is difficult to fill the mold evenly.

[0022] Conventionally, for hot repair, the inner casing is made of metal and is cooled by circulating water. After the repair product has hardened, the inner casing must therefore be removed, as the metal generates bubbles when it comes into contact with the molten glass.

[0023] After the repair product has hardened, the formwork is removed, revealing the reconstituted refractory parts. Generally, however, metal formwork does not allow for the reconstitution of the original shapes if they are complex. The temperature can then be increased to restart the furnace, in an operation called "quenching."

[0024] EP 0 739 861 B1 describes an example of a method for hot repair of glass melting furnaces, in particular the tank.

[0025] JP03-140793 describes an internal formwork for the repair of a side wall of Blast furnace. This formwork consists of vertical plates rigidly fixed to the wall to be repaired by means of horizontal rods. Bags are suspended from the rods and then filled with a repair product. The use of bags effectively prevents leaks into the furnace.

[0026] However, the rods must be securely fixed to the wall and pass through it. The installation of the formwork is therefore lengthy and affects the structure of the furnace.

[0027] These rods must also be dimensioned to retain the plates and be fixed precisely on the plates and on the wall to be repaired.

[0028] There is a permanent need for glass melting furnace repair solutions that resolve the aforementioned problems, in particular allowing the furnace to be put back into production quickly, without degradation of the quality of the glass produced.

[0029] The present invention aims to satisfy, at least partially, this need. Summary of the invention

[0030] The invention relates to a method for repairing a repaired area extending over the intrados of a side wall of the enclosure of a glass melting furnace, said method comprising the following steps: a) installation of an internal formwork comprising, or even consisting of, a flexible textile element and a stiffening element intended to stiffen the internal formwork, so as to create a mold around the area to be repaired; b) filling the mold with a repair product up to a service configuration.

[0031] According to a main aspect of the invention, in step a), the textile element is rigidly fixed to the oven, preferably outside the oven enclosure, preferably on the extrados of the side wall, the textile element being shaped to exert on the stiffening element, in the service configuration, but also during step b), a force opposing the thrust exerted by the repair product on the stiffening element.

[0032] The textile element thus retains the stiffening element against the pressure exerted by the repair product towards the inside of the oven.

[0033] As will be seen in more detail later in the description, the partial, and preferably total, transfer of the pressure of the repair product by the textile element advantageously simplifies the assembly of the internal casing, which is particularly useful for hot repairs. It also makes it possible to limit, or even eliminate, the need for rigid fixings between the furnace and the stiffening element.

[0034] According to another main aspect of the invention, in step a), the stiffening element and / or the textile element, preferably at least the textile element, preferably exclusively the textile element, is rigidly fixed to a surface of the oven different from the intrados of the side wall of the oven enclosure, preferably on the extrados of the side wall of the enclosure.

[0035] As will be seen in more detail later in the description, fixing outside the intrados prevents any damage to the intrados during the assembly of the inner formwork. Fixing outside the intrados is also much simpler to perform. than a fixing on the intrados, particularly during a hot repair.

[0036] According to another principal aspect of the invention, the textile element comprises or is made of a knit.

[0037] As will be seen in more detail later in the description, the use of knitting has proven to be particularly well suited to producing a complex-shaped textile element with a minimum of seams.

[0038] According to another principal aspect of the invention, the textile element, preferably in the form of a pocket, comprises a portion which, in the service configuration, is in contact with the underside of the wall to be repaired, said portion being permeable to the repair product. As will be seen in more detail later in the description, this permeability allows contact between the repair product and the underside of the wall to be repaired, and, after hardening, good adhesion of the repair product to the underside of the wall to be repaired.

[0039] Preferably, the textile element has the shape of a pocket having a first large face, called the "back face", in contact with the intrados of the wall to be repaired in the service configuration, and the part permeable to the repair product includes at least said back face.

[0040] Preferably, the pouch has a second large face, called the "front face", opposite to the first large face, i.e. exposed towards the inside of the oven, and the pouch preferably has a part impermeable to the repair product, the part impermeable, or "watertight" to the repair product includes at least said front face.

[0041] A method according to the invention may further include one or more of the following optional and preferred features: - during steps a) and b), the area to be repaired is at a temperature above 300°C; - in step a), the textile element is rigidly fixed to the outside of the oven enclosure, preferably on the extrados of the side wall; - in step b), a pocket defined by the textile element is filled with the repair product, at least part of which is waterproof to the repair product, the part waterproof to the repair product preferably comprising at least one front face of the pocket; - the pocket includes a part permeable to the repair product, the part permeable to the repair product preferably including at least one rear face of the pocket which, in the service configuration, extends against and in contact with the wall to be repaired; - the textile element defines at least one pocket, and, in step a), the stiffening element, preferably in the form of a plate, is introduced into the pocket or is fixed on a front face of the bag exposed towards the inside of the oven, the bag may (or may not) be airtight to the repair product; - a pocket defined by the textile element is partitioned so as to define a plurality of compartments, and in step a), a stiffening element, preferably in the form of a plate, is introduced into one or more of said compartments and / or, in step b), one or more of said compartments, preferably all of said compartments, are filled with the repair product, said compartments being preferably impermeable to the repair product; - the textile element is made of a material chosen from a ceramic, a metal, an organic material, and mixtures thereof, preferably a ceramic; - the textile element defines at least one link, and, in step a), the link is fixed to the stiffening element, preferably in the form of a plate, preferably at the lower end of the stiffening element, and arranged so as to extend partially, outside the oven, tension being exerted on the link, from outside the oven, so as to pull on the stiffening element; - the knitting comprises a repetition of elementary cells, at least a part of said elementary cells being at least partially closed by at least one closing thread, an elementary cell being defined as the smallest rectangular motif, which by its repetition forms 70%, or more, of the surface of the knitting; the rest of the surface of the knitting may in particular be occupied by singular points, which can classically exist in a knitting, such as for example increases (simple or stripes), decreases (simple or stripes), arrows, selvedges, nets or chains; - more than 30% on average of the total surface area of ​​said elementary cells is blocked by said at least one blocking wire; - more than 40%, preferably more than 90%, by number of elementary cells are at least partially obturated by an obturator wire, preferably by a set of obturators, said obturator wire or set of said obturators together obturating more than 30% of the total surface of said elementary cells at least partially obturated; - more than 30%, by number of elementary cells are at least partially obturated by an obturator wire, preferably by a set of obturators, said obturator wire or set of said obturators together obturating more than 50%, preferably more than 70% of the total surface of said elementary cells at least partially obturated; - more than 90%, by number of elementary cells, are at least partially obturated by an obturator wire, preferably by a set of obturators, said obturator wire or set of said obturators together obturating more than 70% of the total surface area of ​​said elementary cells at least partially blocked; - the knitting is made of a material chosen from among a ceramic, a metal, an organic material, and mixtures thereof, preferably ceramic; - the repetition of the elementary cell allows to cover more than 85%, preferably more than 97% of the surface of the knitting; - the ceramic knit represents more than 5% and less than 25% of the mass of said textile element; - the sealing wires are oriented parallel to each other; and / or - a sealing wire, preferably each sealing wire is made of a material chosen from a ceramic, an organic product, and mixtures thereof, preferably a ceramic; - the knit fabric preferably consists of knit yarn(s) containing more than 95% by mass of oxides; - a sealing wire, preferably each sealing wire containing more than 95% by mass of oxides; - the stiffening element is made of a ceramic matrix composite and / or the textile element is made of a ceramic, the entire internal formwork preferably being made of ceramic; - the stiffening element has the form of a plate, a grid, a frame or a bar; - in step a), the stiffening element is removably attached to the textile element; - the stiffening element is fixed to the textile element so as to adopt a predefined position in the service configuration; - the process includes, after step b), a step 5) of sintering the repair product introduced into the mold in step b); - the sintered repair product obtained consists of a plurality of constituents, the content of any constituent of the sintered repair product being greater than 5%, - differing by less than 20% from the content of said constituent in the stiffening element, and / or - differing by less than 20% from the content of said constituent in a region of the furnace delimiting the area to be repaired, and / or - differing by less than 20% from the content of said constituent in the textile element, the contents being in mass percentages on the basis of the oxides; - the internal formwork is left in the area to be repaired after said repair, that is to say it is not extracted before the furnace is put back into operation; - the stiffening element - is made of a ceramic matrix composite, and / or - includes through holes and / or recesses arranged to be filled by the repair product in step b), and / or - has the form of a plate, flat or not flat, the thickness of the plate being greater than 3 mm and less than 50 mm, preferably to form the bottom of a pocket defined by the textile element; - the internal formwork includes a plurality of stiffening elements arranged, in the service configuration, so that after hardening of the repair product, the repaired wall has the same shape as it initially had, i.e. before being worn; - the internal formwork includes accessories for retaining the stiffening element in the service configuration, said accessories preferably being made of a ceramic matrix composite, said ceramic matrix composite being identical or different from the ceramic matrix composite of the stiffening element when the stiffening element is made of an identical ceramic matrix composite; - the ceramic matrix composite of the stiffening element and / or said accessory - is (are) sintered, and / or - is (are) composed of more than 90% of its mass of oxides, and / or - contain more than 20% and less than 80% by volume of fibers, and / or - comprise(s) fibers composed of more than 90% by mass of oxides and / or arranged in the form of a textile, and / or - comprise(s) a matrix composed of more than 90% oxides by mass percentage, and / or - comprise(s) a matrix comprising Al2O3 and / or SiO2 and / or ZrO2 and / or Cr2O3, and / or - have(s) a total SiO2+Al2O3+ZrO2+Cr2O3 content greater than 80%, by mass percentage on the basis of the oxides.

[0042] In particularly preferred embodiments, the inner formwork comprises: - a textile element, preferably made of a ceramic material, in the form of a pocket having a rear face which, in the service configuration, extends against and in contact with the wall to be repaired, a front face exposed towards the inside of the oven, two side faces joining the side edges of the front and rear faces, and a bottom face, the pocket preferably having an extra length, preferably in the form of a tie, preferably a band, fixed, in step a), to the outside of the enclosure; And - a single stiffening element fixed to the pocket, preferably in a CMC, preferably in the form of a plate or several rigidly fixed plates one to the other, preferably openwork, or of one or more bars rigidly fixed to one another, preferably in the form of an I or a III (the upper and lower ends of the three vertical bars being rigidly connected by upper and lower horizontal bars, respectively); or - a set of stiffening elements attached to the pocket and comprising: - a first stiffening element, preferably made of CMC, preferably in the form of a plate, preferably perforated, or a grid, fixed to the textile element so as to stiffen the front face, preferably disposed in a housing defined by the textile element, and - a second stiffening element, preferably in a CMC, preferably in the form of a plate, preferably perforated, or a bar or an assembly of bars, preferably in the form of an I, fixed to the textile element so as to stiffen one side face of the pocket; Or - a plurality of stiffening elements, each stiffening element, preferably in a CMC, being in the form of a U-shaped frame and being fixed to the textile element, in the service configuration, so that the web of the U stiffens the front face and the two arms of the U stiffen the two side faces, respectively, said stiffening elements in the form of a U-shaped frame being preferably horizontal and superimposed one on top of the other, the web of the highest U-shaped frame being preferably fixed to a tie, the other end of said tie being fixed to the side wall, preferably outside the enclosure.

[0043] Of course, the features, optional or not, of the different main aspects of the invention can be combined, insofar as they are technically compatible.

[0044] The invention also relates to an internal formwork intended for the implementation of a process according to the invention.

[0045] The invention also relates to a glass melting furnace comprising an internal casing according to the invention, and / or at least one region repaired according to a process according to the invention. Brief description of the figures

[0046] Other features and advantages of the invention will become apparent upon examination of the following description and with regard to the accompanying drawing in which: - the [Fig. 1] [Fig. 1], described in the preamble, schematically represents a half cross-section of a glass melting furnace, before wear; - Figure 2 schematically represents an example of formwork conventional; - Fig. 3 [Fig. 3] schematically represents a process according to the invention; - Fig. 4 represents an example of a stiffening element in the form of a plate and having through holes; - [Fig.5] [Fig.5] schematically represents an example of texture for a knit usable as a textile element; - [Fig.6] [Fig.6] schematically represents the knitting object of [Fig.5]; - [Fig.7] [Fig.7] schematically represents an example of knitting incorporating stiffening yarns and usable as a textile element; - [Fig.8] [Fig.8] schematically represents the knit structure of [Fig.7]; - [Fig.9][Fig.9] represents a zoom of the knitting of [Fig.7], which allows in particular to describe the SI and S2 surfaces allowing the calculation of the filling rate; - [Fig. 10][Fig. 10] schematically represents an example of a formwork according to the invention, in the service configuration; - the [Fig. 11][Fig. 11] schematically represents an example of a formwork according to the invention, in the service configuration; - the [Fig. 12] [Fig. 12] schematically represents different examples of formwork according to the invention, in the service configuration; - the [Fig. 13][Fig. 13] schematically represents an example of a formwork according to the invention, in the service configuration; - the [Fig. 14][Fig. 14] schematically represents an example of a formwork according to the invention, in the service configuration; - the [Fig. 15][Fig. 15] schematically represents an example of a formwork according to the invention, in the service configuration; - the [Fig. 16][Fig. 16] schematically represents an example of a formwork according to the invention, in the service configuration; - Fig. 17 [Fig. 17] schematically represents an example of a formwork according to the invention, in the service configuration. In the different figures, identical references are used to designate identical or similar organs. Definitions

[0047] A “formwork” is a part of the “mold” into which the repair product is introduced.

[0048] It results from the assembly of one or more "formwork elements" and the positioning of the assembled formwork element(s). The portion of the mold defined by the formwork is completed with a portion of the oven's inner surface and / or a portion of the textile element that extends against the intrados (inner surface) of the wall, so as to constitute the mold. The relative position of the various elements of The formwork may change shape during filling due to the pressure exerted by the repair product. The "service configuration" is the shape adopted by the formwork at the end of the filling process.

[0049] The formwork elements comprise one, preferably several, stiffening elements, and one, preferably several, textile elements. In addition to the formwork elements, a formwork may include "accessories" used to assemble and fix the formwork elements, and which do not come into contact with the repair product during the repair. Unlike accessories, the formwork elements are parts that come into contact with the repair product during the repair.

[0050] A “textile” is an assembly of fibers, possibly a yarn, in particular an assembly of yarns.

[0051] A "fiber" is a filament whose length is greater than 5 times its equivalent diameter. The "equivalent diameter" of a fiber is the diameter of a disk with the same area as its cross-section at half its length.

[0052] In a textile, the fibers may be assembled in a disordered manner, as in felt or paper, or in one or more preferred directions, preferably in the form of yarns, themselves preferably in the form of one or more fabrics. A yarn of a textile may be - a "single yarn", which is an assembly of fibers which, in cross-section, comprises more than 10 and preferably fewer than 500,000 fibers, and whose length is greater than 5 times the diameter, or - an "assembled wire", which is an assembly of simple wires which, in cross-section, preferably comprises more than 2 and preferably less than 500 simple wires.

[0053] A textile can be, in particular: - an organized structure of fibers and / or threads, simple or assembled, including a knit or fabric, or - a random structure of fibers, and / or yarns, simple or assembled and / or of fibers not incorporated in the form of yarns, said random structure being for example a paper or a felt, a random structure not being preferred.

[0054] The textile of a CMC and of a textile element is preferably an organized structure.

[0055] A "fabric" consists of a network of parallel warp yarns and weft yarns passing transversely through said network.

[0056] A "knit" consists of a network of yarns in the form of loops, optionally reinforced by one or more sets of yarns extending substantially parallel to each other, said set or sets being trapped in said loops.

[0057] A "knitting yarn" is the yarn forming all or part of the stitches of a knitted fabric. A knitted fabric may consist of a single knitting yarn, particularly when said fabric is produced by a weft knitting method. A knitted fabric may also consist of several knitting yarns, particularly when said fabric is produced by a warp knitting technique.

[0058] A set of sealing wires oriented in substantially the same direction is a set of "unidirectional" wires.

[0059] A "net" consists of a set of parallel wires.

[0060] A "veil" is a textile, woven or non-woven, for example knitted, which defines a surface free of openings that could be penetrated by the repair product. Preferably, the spaces between the threads or fibers that make up the veil do not form such openings, so that a veil can constitute a barrier that is impermeable to the repair product.

[0061] A "net" is a textile, woven or non-woven, for example knitted, which, unlike a veil, has openings that can be penetrated by the repair product. The cumulative surface area of ​​these openings may represent more than 5%, more than 10%, more than 30%, more than 60%, more than 90% or more than 95% of the surface area of ​​the veil delimited by its perimeter, that is to say including the surface area of ​​the openings.

[0062] A textile may have the shape of a "pocket". A pocket is defined as a cavity, notably intended to receive one or more stiffening elements and / or repair material. A pocket may be formed, in particular, with a veil and / or a net.

[0063] In the textile element, the textile is flexible, and in particular is not stiffened by a ceramic matrix. Conventionally, this flexibility allows the textile element to be folded or rolled upon itself, preferably by hand, preferably without tools.

[0064] A "link" typically has a length greater than twice its width. A link may, in particular, be in the form of a cord, rope, band, or cable. In one embodiment, a link, preferably each link, is rigidly attached to at least one stiffening element, in particular a plate, made of CMC during its manufacture. The link is thus integrated into the stiffening element, which avoids the need for an additional fastening means. In another embodiment, a link is bonded to the stiffening element.

[0065] A stiffening element is rigid, preferably self-supporting, i.e., retaining its shape when handled at room temperature. Preferably, its shape is not significantly altered during filling with the repair product. Several stiffening elements can be connected to each other by hinges. Two parts rigidly fixed to each other to stiffen the formwork. the interior form a single stiffening element.

[0066] Each stiffening element is preferably made of a CMC.

[0067] By “Ceramic Matrix Composite”, or “CMC”, we classically mean a ceramic composed of a ceramic textile stiffened by a ceramic matrix.

[0068] In a CMC, the textile typically represents between 20% and 80% of the volume of a CMC, the complement to 100% being the matrix.

[0069] Generally speaking, when reference is made to a volume percentage relative to an object, for example a CMC (for example a percentage of fibers) or the matrix of a CMC (as in the preceding sentence), the volume to be considered is that of the object defined by its outer surface, that is to say it includes the empty spaces inside the object.

[0070] 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.

[0071] A "sialon", SiAlON, is an oxynitride compound of at least the elements Si, Al and N, in particular a compound conforming to one of the following formulas: - SixAlON, in which: - x is greater than or equal to 0, greater than 0.05, greater than 0.1 or greater than 0.2, and less than or equal to 1, less than or equal to 0.8 or less than or equal to 0.4, - y is greater than or equal to 0, or greater than 0.1, greater than 0.3 or greater than 0.5, and less than or equal to 1, - u is greater than 0, greater than 0.1 or greater than 0.2, and less than or equal to 1 or less than or equal to 0.7, - v is greater than 0, greater than 0.1, greater than 0.2 or greater than 0.5, or greater than 0.7, and less than or equal to 1, %+y > 0,

[0072] x, y, u and v being stoichiometric indices normalized with respect to the highest one, made equal to 1; - MexSii2-(m+n)Al(m+n)OnNi6.n, with 0 < x < 2, Me a cation chosen from the lanthanide cations, Fe, Y, Ca, Li and their mixtures, 0 < m < 12, Q < n < 12 and 0 < n+m <12, the SiAlON following this formula being generally called "a'-SiA10N" or "SiA10N-a'".

[0073] A “passage” is a hole that goes through the enclosure of the oven, thus connecting the inside and outside of the oven.

[0074] The "equivalent diameter" of a surface is the diameter of a disk with the same area as that surface.

[0075] A dry particulate mixture is classically called an "unshaped product".

[0076] By product "in a material" or "of a material" is meant a product consisting of more than 95%, more than 98%, preferably substantially 100% of its mass of said material.

[0077] By "refractory material" is meant a material having a melting point above 1500°C. This definition is commonly used by those skilled in the art and cited in "Refractory Materials and Technical Ceramics (Elements of Ceramics and Technology)", G. Aliprandi, Septima Paris, 1979. This work also gives examples of refractory materials on pages 297 to 301, including oxides, carbides and nitrides.

[0078] The "glass transition temperature" of a glass is defined as the temperature at which the glass transitions from a solid to a viscous state. The glass transition temperature can be determined by differential thermal analysis (DTA). The glass transition temperature is the temperature at which the glass has a viscosity of approximately 10¹² Pa·s. A glass is conventionally considered to be in a "solid state" at a temperature below its glass transition temperature.

[0079] By "hot binder" is meant a constituent having a melting point above 600°C, and capable of binding together, after hardening under the effect of a drop in temperature, particles with which it has been mixed.

[0080] The "maximum size" is defined as the 99.5th percentile (D995) of a powder, this percentile corresponding to the mass percentage of 99.5% on the cumulative particle size distribution curve of the powder, the particle sizes being ranked in ascending order. The particle size distributions and the maximum size can be determined using a laser particle size analyzer. The laser particle size analyzer can be a Partica LA-950 from HORIBA.

[0081] By "impurities" is meant unavoidable constituents, introduced unintentionally and necessarily with the raw materials or resulting from reactions with these constituents. Impurities are not necessary constituents, but merely tolerated. Preferably, the quantity of impurities is less than 2%, less than 1%, less than 0.5%, or even substantially zero.

[0082] Unless otherwise specified, the "repair product" is the product before it has hardened. It is preferably self-casting, that is to say, capable of spreading under its own weight and filling the mold without causing segregation.

[0083] By "hot self-casting" is meant a repair product capable of spreading under its own weight and filling the mold without causing segregation, within a temperature range of 300°C to 1550°C. Segregation is considered to have occurred when the pouring face of the product obtained after placement of the repair product and sintering exhibits a surface layer of laitance extending from said pouring face to a depth of 3 mm or more. This The surface layer of laitance can easily be highlighted after drying or sintering the product, with sawing carried out in a plane perpendicular to the casting face.

[0084] AZS products are products, preferably electrofused, whose main constituents are alumina (Al₂O₃), zirconia (ZrO₂), and silica (SiO₂). In other words, alumina, zirconia, and silica are the constituents present in the highest mass fractions. These products are well-suited for the manufacture of glass furnaces. More specifically, current AZS products are primarily used for areas in contact with molten glass as well as for the superstructure of glass furnaces. AZS products include, in particular, products marketed by Saint-Gobain SEFPRO, such as ER-1681, ER-1685, and ER-1711.

[0085] When reference is made to ZrO2 or zirconia, this should be understood to mean ZrO2 and traces of HfO2. Indeed, a small amount of HfO2, which is chemically inseparable from ZrO2 in a melting process and has similar properties, is always naturally present in zirconia sources at levels generally below 2%. Hafnium oxide is therefore not considered an impurity. The HfO2 content in AZS particles is preferably less than 5%, less than 3%, or less than 2%.

[0086] Unless otherwise stated, all percentages are mass percentages based on oxides. A mass content of an element is expressed in the form of its most stable oxide.

[0087] A stiffening element is "fixed" to a textile element, or vice versa, if, in the service configuration, no translation of the stiffening element of more than 20 cm can be completed without displacement or deformation of the textile element, except for an upward vertical translation. The fixing may be rigid, in which case no displacement of the stiffening element can be achieved without displacement or deformation of the textile element. It may be non-rigid, for example, if the stiffening element is housed in a recess defined by the textile element.

[0088] The attachment of the textile element to the furnace is rigid in that there is at least one point of contact between the textile element and the furnace at which the textile element and the furnace are rigidly immobilized relative to each other. Attachments made by gluing, by fastening with a knot, or by wrapping around a pin or bar are examples of rigid attachments, particularly for securing the textile element to the furnace.

[0089] Preferably, the textile element is rigidly fixed to the stiffening element by at least two points, preferably at least three points, aligned or not aligned.

[0090] Unless otherwise specified, a fastener may be rigid or not. A fastener between The joining of two parts can be direct, with the two parts in contact with each other in the fixing area, or indirect.

[0091] “Contain” or “include” or “present” should be interpreted as in a non-exhaustive manner. Detailed description

[0092] The formwork is intended, in a service configuration, to be filled with a repair product in order to repair a damaged wall of a glass furnace, in particular a side wall of a furnace chamber. It comprises a flexible textile element and a stiffening element intended to give shape to said repair product. Textile element

[0093] A flexible textile element can be deformed. This makes it advantageously easy to introduce into the oven, for example in a rolled-up form, and then deform it into the desired shape. The deformability of the textile element also facilitates its transport. The stiffening element forms a skeleton which, preferably in cooperation with the textile element, gives the repair product the desired shape in its service configuration.

[0094] According to a principal aspect of the invention, the inner formwork is configured such that, in the service configuration of the inner formwork, the textile element is rigidly attached to the oven, preferably to the wall to be repaired, and in contact with the stiffening element so as to absorb, at least partially, preferably completely, the thrust exerted by the repair product on the inner formwork. In other words, the textile element, attached to the oven, can counteract the forces exerted by the repair product on the stiffening element. It contributes to maintaining the stiffening element in position.

[0095] Advantageously, the textile element limits, or even eliminates, the need for specific fasteners, such as metal rods, to immobilize the stiffening element in relation to the wall to be repaired. This facilitates the installation of the internal formwork.

[0096] Preferably, the stiffening element is held in its service configuration without being rigidly fixed to the furnace, and in particular to the wall to be repaired. It may, in particular, be held in its service configuration exclusively by one or more textile elements.

[0097] Preferably, the textile element is fixed to the wall to be repaired (i.e., the side wall of the enclosure), preferably directly, without an intermediate piece (i.e., the textile element comes into contact with the wall to be repaired in the fixing area). The use of a textile element offers numerous possibilities for fixing the inner casing to the wall to be repaired. In particular, the flexibility of the textile element allows it to be positioned easily, especially for fixing it in an easily accessible area, without damaging the intrados of the wall to be repaired.

[0098] Attaching the stiffening element to the textile element allows the latter to participate in positioning the stiffening element when the textile element is in its service configuration and preferably rigidly fixed to the wall to be repaired. Preferably, the attachment, whether rigid or not, of the stiffening element to the textile element is adapted so that, when the textile element is in its service configuration, the stiffening element, preferably each stiffening element, has a predefined position. This considerably simplifies the installation of the internal formwork, which is particularly advantageous for hot repairs.

[0099] Preferably, the textile element is, before the inner formwork is filled with the repair product, fixed to the wall to be repaired and retains the stiffening element. Preferably, the textile element is configured to counteract the thrust exerted, during filling, by the repair product on the stiffening element.

[0100] Preferably, the textile element is shaped to retain the repair product, in particular to prevent leakage into the oven.

[0101] According to a principal aspect of the invention, the textile element is shaped so that, in the service configuration, it extends partially outside the enclosure. The portion of the textile element extending outside the interior space of the furnace, or "excess length," can be used to retain the textile element against the forces exerted by the repair product.

[0102] This embodiment is particularly advantageous when the textile element has, at least locally, the shape of a pocket defining a top opening for introducing the repair product into the pocket. The pocket may, when laid flat, have a length greater than the height of the wall to be repaired.

[0103] The excess length may extend over all or part of the width of the textile element, and in particular of the pocket (the dimension of the side of the pocket opening which, in the service configuration, rests against the wall to be repaired), preferably in the form of one or more ties, preferably in the form of a strip. It preferably has a length greater than 40 cm, greater than 70 cm, greater than 100 cm, and / or less than 500 cm, and / or a width greater than 1 cm, preferably greater than 3 cm, and / or less than 30 cm, preferably less than 20 cm, preferably less than 10 cm. The procedures for removing the excess length from the furnace chamber and then attaching it are simplified.

[0104] The textile element comprises one or preferably several overlengths, preferably in the form of ties, preferably bands, preferably more than 2 and / or less than 100, preferably less than 50, preferably less than 10 overlengths.

[0105] The excess length may pass through the side wall, preferably outside the area to be repaired, through any passage created for this purpose or preferably pre-existing, preferably through an opening, in particular a burner opening, or by a sight block intended to observe the inside of the furnace in operation.

[0106] The links, preferably the bands, can extend, in the service configuration, to an altitude lower than the altitude of the pocket opening. The weight and size of the pocket are advantageously reduced as a result.

[0107] Preferably, the ties, preferably the strips, do not extend to the bottom of the pocket, that is to say, on the side of the wall to be repaired, the pocket rises, preferably to a height of more than 20 cm, which limits the risks of leakage of repair product from the bottom of the pocket.

[0108] The textile element preferably defines a pocket, preferably having the shape of a pocket, preferably of a generally parallelepiped shape in the service configuration, and / or of a veil and / or of a net, or - of a strip.

[0109] In one embodiment, the textile element defines several pockets intended to receive each a respective stiffening element, preferably in the form of a plate.

[0110] Preferably, the textile element is impermeable to the repair product when the casing is filled with the repair product. Preferably, the textile element is a veil, at least a portion of which is impermeable to the repair product and shaped to form, in the service configuration, at the end of the filling process, an interface between the inside of the furnace and the repair product.

[0111] Said sealed portion covers more than 1%, more than 10%, more than 30%, more than 50%, more than 70%, more than 90%, or even 100% of the part of the inner casing in contact with the inside of the furnace in the service configuration.

[0112] The textile element is preferably made of a material selected from a ceramic, a metal, an organic material, and mixtures thereof. Preferably, the textile element is made of ceramic, particularly for hot repair.

[0113] Preferably, the textile element is made of a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides. The textile element is preferably made of a material resistant to a temperature above 800°C, preferably above 1000°C, preferably a ceramic material, preferably alumina and / or silica and / or E-glass.

[0114] The textile element is preferably made of a fibrous material.

[0115] The textile element may be woven or non-woven. Knitting

[0116] According to a main aspect of the invention, the textile element is, at least in part, preferably completely made up of a knit.

[0117] Knitting offers the advantage of producing a wide variety of shapes without the need for seams. This results in better control of the stress distribution of the repair product, as well as lower manufacturing costs.

[0118] The knit is preferably made of a material selected from a ceramic, a metal, an organic material, and mixtures thereof. Preferably, the knit is made of ceramic, particularly for hot repair. Otherwise, the knit may be, in particular, metallic or made of an organic material.

[0119] It comprises a repetition of elementary cells, at least a part of said elementary cells being preferably at least partially sealed by at least one sealing thread, an elementary cell being defined as the smallest rectangular motif, which by its repetition forms 70%, or more, of the surface of the knit.

[0120] The inventors have discovered that a knit fabric whose elementary cells are at least partially sealed by at least one so-called sealing yarn is particularly well suited to the invention. In particular, it allows the knit fabric to be impermeable to the repair product.

[0121] Preferably, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 95%, more than approximately 100% by number of elementary cells of the knit are at least partially sealed by a sealing yarn, preferably by a set of sealing yarns, preferably unidirectional.

[0122] Preferably, said sealing wire or all of said sealing wires together seal(s) more than 30% of the total surface area of ​​said elementary cells at least partially sealed.

[0123] In particular, said obturator wire or set of said obturator wires together preferably obturate more than 40%, preferably even more than 50%, preferably even more than 60%, preferably more than 70%, preferably more than 80% of the total surface of said elementary cells at least partially obturated.

[0124] Preferably, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 95%, more than approximately 100% by number of the elementary cells of the knit are at least partially sealed by a sealing yarn, preferably by a set of sealing yarns, preferably unidirectional, said sealing yarn or set of said sealing yarns together sealing more than 30%, preferably more than 40%, preferably more than 50%, preferably more than 60%, preferably more than 70%, more than 80% of the total surface of said elementary cells at least partially sealed.

[0125] The ceramic knit preferably comprises, is made of, yarn(s) Choose from: - one or more mesh yarns comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides, - one or more mesh wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbides, - one or more mesh yarns comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of borides, - one or more mesh yarns comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of nitrides, - one or more mesh yarns comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbon, - and a mixture of said mesh threads.

[0126] The ceramic knit comprises, preferably is made up of knit yarn(s) selected from one or more knit yarns comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides. Preferably, said mesh yarn(s) comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides are selected from: - one or more wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such as SiO2 + Al2O3 + ZrO2 > 50%, preferably SiO2 + Al2O3 + ZrO2 > 60%, or even SiO2 + Al2O3 + ZrO2 > 70%, or even SiO2 + Al2O3 + ZrO2 > 80%, or even SiO2 + Al2O3 + ZrO2 > 90%, by mass percentage, - one or more wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such as SiO2 > 70%, of Preference for SiO2 > 80%, preferably SiO2 > 90%, or even SiO2 > 99%, as a percentage by mass. - one or more wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such as Al2O3 > 65%, preferably Al2O3 > 70%, or even Al2O3 > 80%, or even Al2O3 > 90%, or even Al2O3 > 95%, as a percentage by mass, - and their mixtures.

[0127] Preferably, at least a part, preferably said yarn or yarns of mesh are: - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of alumina, and / or - one or more wires composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 95%, preferably more than 98%, of amorphous silica, and / or - one or more yarns composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of mullite, and / or - one or more yarns composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of mullite and corundum, and / or - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of glass, preferably washed.

[0128] Preferably, said mesh wire(s) comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbides are: - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon carbide, - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of boron carbide, - and their mixtures.

[0129] Preferably, said mesh wire or wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of nitrides are one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon nitride.

[0130] Preferably, the mesh yarn(s) have a linear mass greater than 20 g / km, preferably greater than 25 g / km, preferably greater than 30 g / km and preferably less than 300 g / km, preferably less than 250 g / km, preferably less than 200 g / km. The linear mass in g / km is conventionally called "tex".

[0131] Preferably, the knit fabric has a surface mass greater than 50 g / m2, preferably greater than 100 g / m2, and preferably less than 300 g / m2, preferably less than 200 g / m2.

[0132] Preferably, the knitting has a row density of 2 to 5 rows per centimeter and a column density of 1 to 3 columns per centimeter.

[0133] Preferably, the repetition of the elementary cell allows to cover more than 80%, preferably more than 85%, preferably more than 90%, preferably more than 92%, preferably more than 94%, preferably more than 95%, preferably more than 97%, preferably more than 99% of the surface of the knitting, the complement being occupied by singular points, which can classically exist in a knitting, such as for example increases (simple or stripes), decreases (simple or stripes), arrows, edges, nets or chains.

[0134] The knitting is preferably chosen from a jersey knit, an interlock knit, a garter stitch knit, a rice stitch knit, an English rib knit, a 1x1 rib knit, a satin knit and a charmeuse knit.

[0135] The textile element may comprise several different knits linked together, i.e. having different elementary cells, said knits being able in particular to be chosen from the preceding list. Sealing threads

[0136] Preferably, a sealing wire, preferably each sealing wire is a single wire or an assembled wire.

[0137] The sealing wire can be a filler, a float, a unidirectional wire, preferably a unidirectional wire.

[0138] Preferably, the shutter wire, preferably each shutter wire, is a unidirectional wire.

[0139] Preferably, the sealing wire, preferably each sealing wire, is distinct from a mesh wire.

[0140] Preferably the sealing wire, preferably each sealing wire, has a linear mass greater than 100 tex, preferably greater than 300 tex, preferably greater than 500 tex, preferably greater than 600 tex, and preferably less than 3000 tex, preferably less than 2000 tex, preferably less than 1500 tex.

[0141] Preferably, a sealing yarn, preferably each sealing yarn, is inserted into the meshes of the sealed elementary cells of the knit, preferably by depositing and entrapment in the meshes, without support from the meshes.

[0142] The number of sealing wire(s) sealing the elementary cells depends on the surface area of ​​said elementary cell and the linear mass of the sealing wire(s). Preferably, the sealing wires are oriented parallel to each other and preferably along the direction of the rows or columns of mesh.

[0143] In one embodiment, a sealing yarn, preferably each sealing yarn is made of the same material as the knitting yarns.

[0144] In one embodiment, a sealing yarn, preferably each sealing yarn is made of a different material from the material of the knitting yarns.

[0145] A sealing wire, preferably each sealing wire is made of a material selected from a ceramic, particularly for hot repair, a metallic product, an organic product, and mixtures thereof. Preferably, a sealing wire, preferably each sealing wire is made of a ceramic material.

[0146] In a preferred embodiment, a shuttering thread, preferably each shuttering thread, is chosen from: - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides, - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbides, - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of borides, - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of nitrides, - a yarn comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbon, - and a mixture of said yarns.

[0147] Preferably, a sealing wire, preferably each sealing wire, is a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides.

[0148] Preferably, a sealing wire, preferably each sealing wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides is: - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such as SiO2 + A12O3 + ZrO2 > 50%, preferably SiO2 + A12O3 + ZrO2 > 60%, or even SiO2 + A12O3 + ZrO2 > 70%, or even SiO2 + A12O3 + ZrO2 > 80%, or even SiO2 + A12O3 + ZrO2 > 90%, as a percentage by mass, and / or - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such that SiO2 > 70%, preferably SiO2 > 80%, preferably SiO2 > 90%, or even SiO2 > 99%, by mass percentage, and / or - a wire comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and exhibiting a chemical analysis such as A12O3 > 65%, preferably A12O3 > 70%, or even A12O3 > 80%, or even A12O3 > 90%, or even A12O3 > 95%, as a percentage by mass.

[0149] Preferably, at least a part, preferably said thread or said sealing threads are: - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of alumina, and / or - one or more wires composed of more than 90%, preferably 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%, of amorphous silica, and / or - one or more yarns composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of mullite, and / or - one or more yarns composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of mullite and corundum, and / or - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of glass, preferably washed.

[0150] Preferably, said sealing wire(s) comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of carbides are: - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon carbide, - one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of boron carbide, - and their mixtures.

[0151] Preferably, said sealing wire or wires comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of nitrides are one or more wires composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon nitride.

[0152] In a first preferred embodiment, the knit yarn or yarns of the knit are made of a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides and one, preferably each sealing yarn is made of a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides.

[0153] Preferably in this first embodiment: - the said knitting yarn(s) are composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 95%, preferably more than 98%, of amorphous silica, and one, preferably each sealing yarn is composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 95%, preferably more than 98% of amorphous silica;- the said knitting yarn(s) are composed of more than 90%, preferably 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%, of amorphous silica, and one, preferably each sealing yarn is composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably approximately 100% by mass of glass, preferably washed; - the said knitting yarn(s) are composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 95%, preferably more than 98%, of amorphous silica, and one, preferably each sealing yarn is composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of alumina; - the said knitting yarn(s) are composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 95%, preferably more than 98%, of amorphous silica, and one, preferably each sealing yarn is composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of mullite.

[0154] In a second embodiment, the knit yarn(s) of the knit are made of a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of a carbide and one, preferably each sealing yarn is made of a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of a carbide.

[0155] Preferably in this second embodiment, the knit yarn(s) are composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon carbide, and one, preferably each sealing yarn is composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon carbide.

[0156] In a third embodiment, the knit yarn(s) are in a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides, and one, preferably each sealing wire is a material comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of a carbide.

[0157] Preferably in this third embodiment, the knit yarn(s) are composed of more than 90%, preferably more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silica, preferably composed of more than 90%, preferably more than 95%, preferably more than 98%, of amorphous silica, and one, preferably each sealing yarn is composed of more than 95%, preferably more than 98%, preferably more than 99%, preferably substantially 100% by mass of silicon carbide.

[0158] The knitted textile element can be manufactured using techniques known in the prior art. In particular, it can be manufactured by simultaneously knitting a plurality of knitting yarns and / or a plurality of sealing yarns. The knit stitches can thus be formed from a plurality of knitting yarns. Similarly, a plurality of sealing yarns can be introduced into the knit. All combinations are possible, for example, a plurality of knitting yarns with a single sealing yarn, but also a plurality of sealing yarns with a single knitting yarn, or even a plurality of knitting yarns with a plurality of sealing yarns.

[0159] Preferably, the textile element comprises several layers of knitting, preferably is made up of several layers of knitting, at least one of which is a knitting incorporating a sealing yarn, the above characteristics being optionally applicable to this knitting.

[0160] The set of sealing threads is preferably a set of unidirectional threads when the textile element comprises, or is made up of, several knits, preferably arranged in layers.

[0161] In one embodiment, the textile element is made using several pockets inserted one inside the other. Preferably, each pocket is knitted. Preferably, each pocket includes a set of sealing yarns, preferably unidirectional yarns, preferably unidirectional yarns in a different direction from one pocket to another, preferably in a direction at 90° from one pocket to the other.

[0162] The introduction of at least one sealing yarn into the elementary cells of a knit can advantageously be carried out with conventional knitting machines. Stiffening element

[0163] The stiffening element is preferably chosen from a plate, solid or openwork, a closed frame, for example rectangular, preferably an open frame, preferably L-shaped or U-shaped, and a bar.

[0164] Preferably, the formwork includes a stiffening element, for example in the form of a bar, which preferably extends substantially in a vertical plane in the service configuration, preferably not extending along an edge of the formwork to avoid the formation of a sharp edge, and preferably over the entire height of the formwork. The ends of vertical bars can be rigidly fixed to the ends of horizontal bars to define a stiffening element in the form of one or more frames, preferably open, or even a cage.

[0165] In one embodiment, at least one stiffening element, or even each stiffening element, extends, in the service configuration, substantially horizontally, preferably substantially parallel or perpendicular to the wall to be repaired. Such a stiffening element extending perpendicularly to the wall to be repaired can, in particular, serve to distance at least a portion of the textile element from the wall to be repaired, for example, to provide an opening for introducing the repair product.

[0166] Preferably, the stiffening element has the form of a formwork plate, flat or not flat, preferably flat, the thickness of the plate being greater than 3 mm, preferably greater than 8 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.

[0167] In a preferred embodiment, the formwork plate has a surface area greater than 500 cm2 and / or less than 1 m2.

[0168] The formwork plate can in particular be a plate substantially parallel to the wall to be repaired of the furnace, or a plate perpendicular to the wall to be repaired of the furnace, in particular at the ends of the area to be repaired.

[0169] The formwork plate is preferably fixed, preferably rigidly, on a pocket, a veil or a net of the textile element.

[0170] In one embodiment, at least one tie, preferably a strip, preferably several ties, preferably several strips, made of a textile are attached to the stiffening element, for example a formwork panel or a frame, preferably open, preferably by bonding or integrated into the stiffening element during its manufacture, in particular if the stiffening element is made of a CMC. For example, at least two ties, preferably two strips, may be attached to the top of the formwork panel and at least two ties, preferably two strips, may be attached to the bottom of the formwork panel. The ties, preferably the strips, may be attached to the outside of the enclosure and to serve to hold the stiffening element in position, and in particular to retain the formwork plate.

[0171] In one embodiment, the formwork plate is fixed inside a pocket.

[0172] In a preferred embodiment, the formwork plate is arranged inside of a pocket, without being rigidly fixed to the textile element. Preferably, the shape of the pocket is roughly that of the formwork panel, which allows the formwork panel to be held effectively in place. The pocket can be replaced, in a substantially equivalent manner, by strips that at least partially encircle the formwork panel.

[0173] In particular, one or more formwork panels can be attached to a pocket, a canvas, a net, or one or more strips. The resulting assembly can be deformed to facilitate its insertion into the furnace and then deployed within the furnace to reach the operating configuration. The textile element limits the relative positions of the formwork panels with respect to each other, which greatly facilitates deployment.

[0174] A similar result can be obtained by equipping the textile element with means for attaching said formwork plates, for example by providing it with a plurality of pockets intended to receive each of a respective formwork plate.

[0175] The internal formwork preferably includes a "bottom" stiffening element, that is to say substantially parallel to the floor of the furnace in the service configuration, and preferably configured to impose, in the service configuration, a predefined shape on the lower part of the formwork.

[0176] The bottom stiffening element preferably has the shape of a plate, a frame, a bar, preferably the shape of a bar, in particular when the textile element is a veil.

[0177] The base stiffening element preferably rests on the furnace floor in the service configuration. Advantageously, it facilitates the positioning of the formwork relative to the wall to be repaired. The base stiffening element is preferably fixed or placed on the bottom of a pocket or sleeve defined by the textile element.

[0178] In one embodiment, at least one stiffening element, or even each stiffening element, extends, in the service configuration, parallel to the wall to be repaired, preferably horizontally or vertically.

[0179] In one embodiment, at least one stiffening element, preferably a base stiffening element, has through holes and / or recesses, as illustrated in [Fig. 4]. Filling these holes and recesses with the repair product in step b) advantageously provides better immobilization of the formwork and reduces the thermal gradient in the repair product during the sintering stage and to facilitate the handling of said stiffening element by reducing its mass. Preferably, the average equivalent diameter of the holes is greater than 8 mm and preferably less than 350 mm, preferably less than 300 mm.

[0180] In one embodiment, said stiffening element is in the form of a grid, the holes being preferably distributed homogeneously, the total surface of the holes representing more than 10%, preferably more than 15% and preferably less than 80%, preferably less than 70% of the surface of said stiffening element delimited by its perimeter, that is to say the surface participating in the definition of the mold around the region to be repaired (surface of the holes and of the material of the grid).

[0181] The creation of through holes and / or indentations can be achieved by any technique known to a person skilled in the art. In particular, through holes can be made by drilling or cutting under a water jet, for example on ceramics, preferably in the form of a CMC (Certified Metal Coating), obtained after sintering. In a CMC, through holes and / or indentations can also be made on textiles, preferably woven textiles, before coating with slip.

[0182] The stiffening element is preferably fixed on the textile element so as to have limited mobility, or even to be held in position relative to the textile element during the introduction of the formwork into the oven and / or during the filling of the formwork.

[0183] The stiffening element can be attached to the textile element, preferably by sewing, with openings preferably provided for this purpose in the stiffening element, or glued to the textile element, integrated into the textile element, particularly when the stiffening element is made of a CMC, or enveloped by the textile element, for example housed in a sleeve or pocket defined by the textile element, or inserted into the thickness of the textile element. The attachment can be ensured by one or more attachment points, preferably at least three attachment points, and / or by one or more attachment lines, or even by an attachment surface, for example with a surface area greater than 5 cm².

[0184] Preferably, the stiffening element is removable, i.e., it can be detached from the textile element without breaking any part of the casing, for example, without breaking a glue point or a stitch. Preferably, the stiffening element is removable by hand, preferably without tools, and preferably reversibly.

[0185] The removable feature advantageously allows for a modular formwork. In particular, the formwork can be easily adapted to the area of ​​the wall to be repaired.

[0186] The formwork preferably comprises several stiffening elements, for example in the form of bars or frames, arranged preferably at regular intervals, preferably substantially horizontally, over the height of the formwork, for example spaced more than 10 cm and / or less than 50 cm apart, preferably less than 40 cm apart, the textile element preferably having a pocket on which the stiffening elements are fixed.Bars can form a rigidifying element in the form of a frame, preferably open, or a grid which, combined with a textile element forming an interface between the inside of the oven (i.e. the space defined by the oven chamber) and the repair product, for example in the form of a veil, makes it possible to obtain the function of a conventional formwork plate (retention of the repair product by imposing a predefined surface, for example substantially flat, on the repair product) while benefiting from great flexibility for installation in the service configuration.

[0187] The stiffening element is preferably made of a material resistant to a temperature above 1000°C, preferably resistant to a temperature above 1200°C.

[0188] The stiffening element is preferably a ceramic, preferably an oxide, preferably the total content of SiCl+AhOi+ZiLL+CiyOiCtant greater than 80%, preferably greater than 90%, preferably greater than 95%, as a percentage by mass on the basis of the oxides. CMC

[0189] The stiffening element is preferably made of a Ceramic Matrix Composite (CMC). The use of ceramic stiffening elements, particularly in the form of a CMC, advantageously allows for the construction of formwork that does not require cooling. This formwork can therefore be lighter (especially if made with thin plates). Furthermore, due to the absence of cooling, this internal formwork is very quick to install.

[0190] Furthermore, a ceramic, particularly in the form of a CMC, does not significantly alter the quality of the manufactured glass when it comes into contact with molten glass or with the corrosive vapors present in the furnace, and therefore does not require the removal of the inner lining at the end of the repair. A particularly rapid return to production of the furnace, without the repair affecting the quality of the glass, and in particular without affecting the number of defects in the glass, is advantageously possible.

[0191] Finally, the internal formwork can be of complex shape.

[0192] Furthermore, a ceramic, in particular in the form of a CMC - is lightweight, which makes it easier to handle, - is easy to conform to complex geometries, allowing for precise adaptation to the configuration of the region to be repaired.

[0193] In addition, a CMC is highly resistant to thermal shock, which allows for hot repair without degradation of the stiffening elements when they are introduced into the oven.

[0194] The manufacture of a CMC can be carried out by any conventional method, and in particular includes the following steps: (i) disposition, on or in a textile, of a slip capable of forming a ceramic matrix after consolidation; ii) before or after step i), shaping of the textile; iii) consolidation of the preform obtained after the previous steps, preferably by drying and / or sintering, preferably by sintering, so as to form said matrix and obtain the CMC.

[0195] In step i), the textile may in particular have the form of a sheet, for example a sheet made up of yarns extending substantially parallel to each other (the said yarns being called "unidirectional yarns"), a knit, a fabric (i.e. a woven textile) or a stack of one or more sheets and / or knits and / or fabrics.

[0196] The textile preferably has the form of a felt or a fabric or a layer or a stack of felt(s) and / or layer(s) and / or fabric(s). The stack of fabrics and / or layers can be arranged so that the threads of the different fabrics or layers all extend substantially in the same direction, or in 2, 3, 4, 5 or 6 different directions, depending in particular on the mechanical properties required.

[0197] Preferably, at least a part, preferably all of the textile fibers possibly assembled in the form of single yarns and / or assembled, are fibers in a ceramic, preferably fibers comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides.

[0198] Preferably, all the fibres have the same composition.

[0199] The arrangement of the slip on or in the textile can be, for example, by im Pregnancy. Said stacking can be achieved by pressing, or under vacuum, preferably after impregnation.

[0200] 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 the CMC, and in particular during hardening, in particular sintering, and - optionally dispersants, plasticizers, lubricants, and / or binders temporary.

[0201] The composition of the slip, the size distribution of the ceramic particles or ceramic precursors, and the mineral content of the slip are adapted to the type of fiber and the shaping technique. For example, the slip can be deposited on or within the textile, particularly by direct lamination, by infusion, injection, infiltration, or deposition, under atmospheric pressure or under higher pressure or under vacuum, at ambient temperature or at higher temperatures.

[0202] Preferably, the ceramic particles are particles comprising more than 95%, preferably more than 97%, preferably more than 98%, preferably more than 99%, preferably more than 99.5% by mass of oxides.

[0203] In step ii), the resulting textile, preferably impregnated with the slip, is shaped. The desired shape is preferably the final shape of the CMC. In one embodiment, however, the shape can be modified after the matrix has hardened, for example by machining or deformation.

[0204] In step iii), consolidation is preferably carried out by sintering.

[0205] A person skilled in the art knows how to adjust the parameters of the process chosen for the manufacture of the CMC, and in particular how to determine the particle size of the raw materials, the water content during shaping, and the sintering temperature if the ceramic is sintered.

[0206] Preferably, the stiffening element is made of a ceramic and - said ceramic, preferably in the form of a CMC, is sintered; and / or - said ceramic, preferably in the form of a CMC, is composed of oxides for more than 90% of its mass, preferably for more than 95% of its mass, preferably for more than 98% of its mass, preferably for more than 99% of its mass, preferably for more than 99.5% of its mass. The compatibility of the ceramic, particularly in the form of a CMC, with molten glass during normal furnace operation is advantageously improved.

[0207] Preferably, in said ceramic, preferably in the form of a CMC, the total content of SiO2+Al2O3+ZrO2+Cr2O3 is preferably greater than 80%, preferably greater than 90%, preferably greater than 95%, as a percentage by mass on the basis of the oxides.

[0208] Preferably still, - said CMC comprises more than 20% and less than 80% by volume of fibers, the remainder being constituted by the matrix and / or - the fibers of said CMC are composed of more than 90%, preferably more than 99%, preferably 100% oxides, by mass percentage, preferably consisting of an oxide and / or - the fibers of said CMC are arranged in the form of a textile, preferably a fabric and / or - the matrix of said CMC is composed of more than 90%, preferably more than 99%, preferably 100% oxides, by mass percentage and / or - the matrix of said CMC comprises Al2O3 and / or SiO2 and / or ZrO2 and / or Cr2O3 and / or - in the matrix of said CMC, the total content of SiO2+Al2O3+ZrO2+Cr2O3 is preferably greater than 80%, preferably greater than 90%, preferably greater than 95%, as a percentage by mass on the basis of the oxides. Accessories

[0209] In addition to the textile element(s) and stiffening element(s), the internal casing may include accessories, preferably a fixing element intended for fixing the textile element to the oven.

[0210] The formwork may include accessories made of ceramic, preferably in the form of a CMC, said formwork elements and accessories preferably not being cooled, and in particular not being cooled by means of water circulation. Hot repair

[0211] A method according to the invention, illustrated in [Fig.3], is preferably used for the hot repair of a region of a glass melting furnace.

[0212] In one embodiment, particularly for repairing a tank initially containing a bath of molten glass in contact with the area to be repaired, the repair process comprises the following steps: 1) if the area to be repaired is, at least partially, delimited by a surface of the furnace tank in contact with the molten glass bath, drain, at least partially, of said molten glass out of the tank, so as to expose said area to be repaired; 2) Optionally, but preferably, rinse the area to be repaired to remove any glass residue; 3) reducing the temperature in the oven to a temperature above 300°C, preferably above 400°C, preferably above 500°C, preferably above 600°C, preferably above 700°C, preferably above 800°C, preferably above 900°C, and preferably below 1550°C, preferably below 1500°C, or even below 1450°C or 1400°C; 4) installation of the repair product following steps a) and b); 5) increasing and maintaining the oven temperature between 900°C and 1400°C in order to sinter the repair product; 6) introduction of a glass composition to be melted into the tank and increase of the furnace temperature to an operating temperature leading to the melting of said composition.

[0213] In one embodiment, the repair product used in step b) contains a (hot binder, and in step 3), the temperature in the furnace is reduced to a temperature at which the hot binder is not in a solid state. In particular, when the hot binder is a glass, the temperature in the furnace is reduced to a temperature that remains above the glass transition temperature of said glass. Said glass is preferably chosen so that its glass transition temperature is between 600°C and 1350°C, preferably between 900°C and 1350°C, preferably between 1000°C and 1300°C, preferably between 1150°C and 1250°C.

[0214] At step 4), the formwork is installed by assembling its elements.

[0215] In step a), the installation of the internal formwork is delicate due to the differences access difficulties.

[0216] The flexible textile elements can be advantageously and easily deformed to facilitate their introduction into the oven.

[0217] Conventional accessories may optionally be used to consolidate the retention of the formwork elements in the service configuration.

[0218] In step b), the mold which delimits the area to be repaired is filled with a repair product, preferably by casting. Repair product

[0219] The repair product may be a conventional repair product and may be prepared by any known technique.

[0220] Preferably, the repair product is the result of moistening an unshaped product. This moistening can be carried out using any known technique, for example in a mixer. A person skilled in the art knows how to determine the quantity of solvent, preferably water, to be used to moisten the unshaped product and obtain the repair product.

[0221] The unprocessed product may include, in particular: - Repair Hot Overcoat AZS, Repair Hot Overcoat Alumina or Repair Hot Overcoat Chrom50, particularly when the area to be repaired is located on a wall of the furnace chamber, or - the Repair Hot Overcoat Fused Silica when the area to be repaired is located at the level of the vault.

[0222] These unfinished products are marketed by the company Saint-Gobain Sefpro.

[0223] Preferably, the maximum particle size of the repair product or, of equivalently, of the unshaped product, is less than 10 mm, preferably less than 8 mm, preferably less than 6 mm.

[0224] The particle size distribution of the repair product or, equivalently, of the unshaped product is preferably determined so that the repair product is hot self-casting.

[0225] Preferably, the repair product is chosen so as to present an analysis chemical similar to that of the furnace material which delimits the area to be repaired, preferably so that the content of any constituent of the repair product differs by less than 10% from the content of said constituent in said material.

[0226] For example, if the area to be repaired is delimited by one or more refractory blocks made of an AZS (Alumina Zirconia Silica) product, the unshaped product used to manufacture the repair product is preferably Repair Hot Overcoat AZS, depending on the location of the area to be repaired in the glass melting furnace. If the area to be repaired is delimited by one or more refractory blocks made of an AZS-Chrome product, the unshaped product used to manufacture the repair product is preferably Repair Hot Overcoat Chrom50. Finally, if the area to be repaired is delimited by one or more refractory blocks made of a silica product, the unshaped product used to manufacture the repair product is preferably Repair Hot Overcoat Fused Silica.

[0227] The repair product can be brought to the area to be repaired using any technique known to a person skilled in the art. If access to the area to be repaired is difficult, one or more passages, for example by drilling, can be made from the outside to the inside of the furnace. These passages advantageously allow the introduction of the means of conveying the repair product, for example a cooled rod or a nozzle, to the area to be repaired.

[0228] In one embodiment, the repair product is pumped by means of a pump producing a suction pressure preferably less than or equal to 180 bar and preferably conveyed to the area to be repaired by means of a water-cooled lance or nozzle.

[0229] During the whole of step b), the area to be repaired is preferably maintained at a temperature above 300°C, preferably above 400°C, preferably above 500°C, preferably above 600°C, preferably above 700°C, preferably above 800°C, preferably above 900°C, and / or preferably below 1550°C, preferably below 1500°C.

[0230] In step 5), optional, and in particular if the process includes a step 3), the furnace is maintained at a temperature between 900°C and 1400°C, preferably between 1250°C and 1400°C, preferably between 1300°C and 1400°C, in order to allow the sintering of the repair product, preferably for a period of more than 8 hours, preferably more than 10 hours and preferably less than 15 hours.

[0231] At step 6), normal operation of the furnace is resumed: A composition of glass to be melted is introduced into the furnace and, if said process includes a step 3), the temperature of the furnace is increased to put it back into operation. Examples

[0232] The following non-limiting examples are given for the purpose of illustrating the invention.

[0233] Figures 5 to 9 illustrate knits that can be used for the textile element.

[0234] Figures 5 and 6 illustrate a Tl knit in picked stockinette type jersey in Quartzel® yarns having a basis weight of 120 g / m2, a row density of 3.43 rows per centimeter and a column density of 2.1 columns per centimeter, of rectangular shape of length equal to 300 mm and width equal to 300 mm, manufactured by the company Saint-Gobain Performance Plastics, said Quartzel® yarns bearing the reference C9 33 Z20 QS1318 and being marketed by the company Saint-Gobain Quartz.

[0235] The texture of this knit is described in [Fig.5].

[0236] Figure 6 is a representation of a knit Tl in which the marker 1 represents the Quartzel® yarns and in which the elementary cell of this knit is illustrated by the dotted rectangle SL

[0237] Figures 7 and 8 illustrate a T2 knit identical to the T1 knit but incorporating sealing yarns, represented on [Fig.7] by grey lines 2, said sealing yarns being Quartzel® yarns of reference C14 640 QS1318 marketed by the company Saint-Gobain Quartz, deposited in the direction of the rows of stitches, without support in the stitches, said yarns being trapped in said stitches.

[0238] The total basis weight of each knitted support is equal to 1000 g / m2 for a mesh density equivalent to that of the Tl knit, said yarns being oriented substantially all in the same direction (that of the rows of stitches), as illustrated in [Fig.7]

[0239] The texture of this knit is illustrated in [Fig.8].

[0240] The sealing rate is the ratio between the surface area S2 occupied by all the Quartzel® sealing yarns in the elementary cell and the surface area SI of the elementary cell described above, as illustrated in [Fig. 9]. For the T2 knit, it is thus calculated that 59% of the total surface area of ​​the elementary cells is sealed by the sealing yarns. In this example, 100% (by number) of the elementary cells are sealed by said yarns.

[0241] In a particularly advantageous embodiment, illustrated in [Fig. 10], the inner casing 32 comprises a textile element 50 in the form of a pocket intended to receive the repair product, preferably made of knit fabric, and a stiffening element 52 in the form of a plate, preferably made of CMC, arranged inside the pocket.

[0242] The textile element 50 has an extra length 54 which is fixed to the outside of the enclosure, preferably on the extrados. The fixing is preferably achieved by winding, for example around a cleat, or by hooking, for example on a hook, by gluing or by pinching, preferably on the extrados 31.

[0243] The repair product 30 is introduced into the pocket through the upper opening of the pocket (broad arrow). It exerts a thrust P, symbolized by a horizontal arrow, on the stiffening element 52. The stiffening element opposes this thrust P with a reaction force R on the stiffening element 52, opposite and of the same magnitude.

[0244] The inner formwork 32 may optionally include a bar 58, preferably made of ceramic, preferably of a CMC, or a tie, in particular a textile strip, optionally integrated into the textile element, intended to be held in position in contact with the upper part of the plate or pocket, so as to counteract, together with the textile element, the pressure exerted by the repair product towards the interior of the furnace, i.e., so as to pull the upper part of the plate or pocket towards the intrados of the wall to be repaired. The bar 58 may also be used to hold the pocket open during filling.

[0245] The formwork may also include a wedge, preferably in the form of a wedge brick 60, intended to rest on the base 24 and supported on the lower part of the plate, so as to prevent the said inner part from sliding towards the interior of the oven.

[0246] As illustrated in [Fig. 11], the stiffening element can be immobilized on the pocket in a predefined position, for example inserted into a housing, preferably of substantially complementary shape, for example in the form of a pouch. In [Fig. 11], in a non-preferred embodiment, two stiffening elements are immobilized on the pocket formed by the textile element 50. These stiffening elements 52i and 522, respectively, in the form of plates, are immobilized one above the other by insertion into housings 62i and 622, respectively.

[0247] Figure 12 illustrates different embodiments, which can be combined:

[0248] Figure 12A represents a textile element 50 whose "back face" 50a is made of a The textile is permeable to the repair product before it hardens. Preferably, the "front face" 50b is made of a textile permeable to the repair product before it hardens, preferably a knit T1 as described above. The side faces 50c, joining the lateral edges of the front and rear faces along the vertical edges 63, and the bottom face 50d are preferably made of a textile impermeable to the repair product before it hardens, preferably a knit T2 as described above. This embodiment ensures good adhesion of the repair product to the wall being repaired, preventing leakage into the oven before hardening.

[0249] In Figure 12B, the inner formwork includes a grid-shaped stiffening element, which can be fixed, preferably rigidly, to the inside or to the outside (as shown), preferably inside the pocket defined by the textile element.

[0250] In Figure 12C, the inner casing comprises a stiffening element in the form of a substantially vertical plate, for stiffening the front face of the pocket exposed inside the oven, and, for each lateral face of the pocket, three superimposed, regularly spaced stiffening elements in the form of substantially horizontal bars. In the illustrated embodiment, the bars are outside the pocket and the plate is inside the pocket defined by the textile element. Preferably, however, the bars are inside the pocket and the plate is inside the defined pocket.

[0251] In Figure 12D, the inner casing includes a stiffening element in the form of a substantially vertical plate, to stiffen the front face of the ladle exposed inside the furnace. In the illustrated embodiment, the plate is outside the ladle and inside a recess defined by a horizontal strip 65h whose ends are fixed to the ladle and a vertical strip 65v whose ends are fixed to the horizontal strip and to the ladle.

[0252] In Figure 12E, the inner casing includes a stiffening element in the form of a substantially vertical plate to stiffen the front face of the pocket exposed inside the furnace, and, for each lateral face of the pocket, a stiffening element in the form of a plate, substantially vertical and substantially perpendicular to the wall to be repaired. In the illustrated embodiment, the stiffening elements are all inside the pocket. The textile element has two excess lengths in the form of ties, preferably strips.

[0253] In Figure 12F, the inner casing includes a plate-shaped stiffening element, which can be fixed, preferably rigidly, to the inside (as shown) or to the outside, preferably inside the pocket defined by the textile element. The textile element has an extra length across the entire width of the pocket.

[0254] In Figure 13A, the casing comprises several textile elements in the form of pockets 50b 502, each containing a plate 52b 522, respectively, the pockets being arranged adjacent to one another or separated by an independent plate 523, i.e., not arranged within a pocket. The independent plate is preferably arranged so as to rest, in the service configuration, on the adjacent plates fixed, preferably rigidly, to two pockets arranged on each side of the independent plate. Preferably, the adjacent plates act as a stop to prevent the independent plate from moving towards the interior of the oven.

[0255] In figure 13A, the two side plates are sewn inside the pockets.

[0256] In Figure 13B, which represents a top view of Figure 13A, the two Side plates 52i and 522 are sewn inside the pockets, and the inde- pendant 523 is housed in folds 72 formed by pockets 50i and 502.

[0257] Figure 14 illustrates a particularly advantageous embodiment. The formwork It comprises a textile element in the form of a pocket, preferably knitted, and a stiffening element in the form of a bar, preferably several stiffening elements in the form of bars. The bars are preferably connected to each other to form a stiffening element in the form of one or more frames, preferably several open frames, preferably U-shaped and open towards the wall to be repaired.

[0258] Preferably, the frames extend horizontally in the service configuration, preferably spaced apart from each other by a distance d between 10 cm and 30 cm. Preferably, they are fixed, preferably removably, to the pocket, preferably inside the pocket.

[0259] Preferably, at least one frame, preferably each frame is also held in position on the textile element, preferably by insertion into a sleeve or by sewing. Preferably, the core of the highest U-shaped frame is attached to a tie forming an overlength 54, the other end of said tie being attached to the side wall, preferably on the outside of the enclosure. Preferably still, the core of each other U-shaped frame is attached by a tie 55 to the frame above it.

[0260] Fig. 15 illustrates another particularly advantageous embodiment. The textile element is in the form of a pocket, substantially parallelepiped in the service configuration, provided with extra lengths in the form of ties in order to fix it to the outside of the enclosure, preferably on the extrados of the wall to be repaired.

[0261] The inner formwork comprises a III-shaped stiffening element (Roman numeral 3) that stiffens the exposed face of the pocket inside the furnace, and, for each side of the pocket, an I-shaped stiffening element, substantially vertical and substantially perpendicular to the wall to be repaired. In the illustrated embodiment, the stiffening elements are all inside the pocket. Preferably, the III-shaped stiffening element is not connected to the I-shaped stiffening elements.

[0262] Preferably, no vertical bar extends along the edges, which helps to avoid sharp angles.

[0263] The textile element has two extra lengths in the form of strips.

[0264] The III-shaped stiffening element can be replaced by a plate, preferably perforated. The presence of a bottom stiffening element, preferably in the shape of a bar, is also possible.

[0265] In one embodiment, the inner formwork may comprise several modules such as that shown in [Fig. 15], arranged side by side, adjacently. Preferably, I-shaped stiffening elements are not positioned only on the lateral faces at the lateral ends of the inner formwork. In other words, no I-shaped stiffening element is positioned at the interface between two adjacent pockets.

[0266] Fig. 16 illustrates an internal formwork according to the invention in the form of a partitioned pocket so as to define a plurality of boxes, preferably extending substantially vertically, separated by partitions 74.

[0267] The partitions 74 can isolate the boxes they separate from each other, i.e. prohibit the transfer of repair product between these boxes, or on the contrary allow communication between these boxes, i.e. authorize the transfer of repair product between these other boxes.

[0268] Preferably, the caissons, or "inter-caisson walls," extend substantially vertically, and preferably also substantially perpendicularly to the side wall. The shape and structure of the caissons are preferably determined to create reinforcements along lines of force, so that the weight of the repair product gives a predetermined shape to the formwork.

[0269] In one embodiment, at least one, preferably each partition, comprises and / or constitutes a stiffening element, preferably made of ceramic. One or more stiffening elements may be fixed, preferably rigidly, to a partition.

[0270] Unlike bags or pouches placed side by side, the compartments interact with each other to create a predefined shape in the service configuration. Furthermore, it is not necessary to fix each pouch to the oven, which reduces costs. Finally, the partitions 74 can form a mechanically reinforcing framework after curing.

[0271] In one embodiment, as illustrated in [Fig. 16], the textile element comprises at least one central box 503' and two lateral boxes 501' and 502', adjacent to the central box. The rigidity of the central box can then be obtained from that of the lateral boxes, in particular after filling the latter with repair material. In particular, the front face of the central box exposed inside the oven may be without a stiffening element, as illustrated.

[0272] Figure 17 illustrates an internal formwork according to the invention in which the stiffening element 52, in the form of a plate, is held in position partially by means of a tie 77, preferably in the form of a strip. The tie, preferably the strip, is attached to the lower part of the plate and pulled from outside the enclosure so as to exert a tension, a component R of which opposes the thrust exerted by the repair product on the plate. It advantageously exerts an action equivalent to the wedge 60 shown in Figure 1, which is generally difficult to position, particularly for hot repairs.

[0273] The link, preferably the band, is fixed to the outside of the enclosure, while the The repair product hardens. After the repair product has hardened, the bond, preferably the tape, is embedded in the hardened repair product.

[0274] The bar 58 is used to hold the plate so that it does not fall either towards the inside of the oven or towards the wall to be repaired. Preferably, a bar 58 is used to prevent the plate from falling towards the wall to be repaired, and a tie, preferably a band, fixed to the plate is used to prevent the plate from falling towards the inside of the oven.

[0275] As is now clear, the invention provides a casing and a method for repairing a glass melting furnace that uses this casing which: - facilitate the introduction of the formwork elements into the oven, in particular by folding or rolling the textile elements; - allow for quick and easy installation, in particular because the textile element can be easily fixed outside the intrados of the side wall to be repaired; - facilitate the arrangement of stiffening elements, particularly when they are fixed to a textile element; - allow a sacrifice of the formwork elements, i.e. their retention in the kiln after the repair, in particular because the composition of a ceramic, preferably in the form of a CMC, can be chosen to be similar to that of the repair product.

[0276] Of course, the present invention is not limited to the embodiments described or represented, provided by way of illustrative and non-limiting examples.

[0277] In particular, the compositions of the ceramics and / or the structures of the CMC of the different parts of the formwork and / or accessories may be identical or different.

[0278] The detailed description generally mentions a textile element and a stiffening element for clarity. The inner formwork may, however, comprise several textile elements and / or several stiffening elements, and the optional features described above for the textile element and the stiffening element are also optional features applicable to each textile element and each stiffening element of the inner formwork, respectively.

[0279] Not all textile elements are necessarily identical and / or used in the same way. For example, the inner casing may comprise several textile elements, only some of which are fixed, preferably rigidly, to the oven.

[0280] Nor are all stiffening elements necessarily identical and / or used in the same way. For example, the internal formwork may include several stiffening elements, only some of which are fixed, preferably rigidly, to a textile element.

[0281] Preferably, the inner casing comprises at least one textile element and several stiffening elements.

Claims

Claims

1. Method for repairing a region to be repaired (30) extending over the intrados (29) of a side wall (22, 26) of the enclosure of a glass melting furnace (10), said method comprising the following steps: a) installation of an internal formwork (32) comprising a flexible textile element (50) and a stiffening element (52) intended to stiffen the internal formwork, so as to produce a mold (36) around the region to be repaired; b) filling the mold with a repair product (41) to a service configuration; method in which, in step a), the textile element is rigidly fixed to the furnace, the textile element being shaped to exert on the stiffening element, in the service configuration, a force (R) opposing the thrust (P) exerted by the repair product on the stiffening element.

2. Method according to the preceding claim, in which, during steps a) and b), the region to be repaired is at a temperature above 300°C.

3. Method according to any one of the preceding claims, in which, in step a), the textile element is rigidly fixed to the outside of the oven enclosure, preferably on the extrados of the side wall (22, 26).

4. Method according to any one of the preceding claims, in which, in step b), a pocket defined by the textile element and at least one part of which is impervious to the repair product is filled with the repair product, the part impervious to the repair product preferably comprising at least one front face (50b) of the pocket.

5. A method according to any one of the preceding claims, wherein the textile element defines a pocket, identical to or different from the pocket mentioned in claim 4, said pocket comprising a part permeable to the repair product, the part permeable to the repair product preferably comprising at least one rear face (50a) of the pocket which, in the service configuration, extends against and in contact with the wall to be repaired.

6. A method according to any preceding claim, wherein, in step a), the stiffening element is introduced into a pocket defined by the textile element or is fixed to a front face (50b), exposed towards the interior of the oven, of a pocket defined by the textile element, said pocket being able to be identical or different from the pocket mentioned in claims 4 and 5.

7. Method according to any one of the two immediately preceding claims, in which the textile element defines a pocket, identical to or different from the pocket mentioned in claims 4 to 6, said pocket being partitioned so as to define a plurality of boxes, and in which in step a), a stiffening element, preferably in the form of a plate, is introduced into one or more of said boxes and / or, in step b), one or more of said boxes, preferably all of said boxes, are filled with the repair product.

8. A method according to any one of the preceding claims, wherein the textile element is made of a material chosen from a ceramic, a metal, an organic material, and mixtures thereof, preferably a ceramic.

9. A method according to any preceding claim, wherein the textile element comprises or consists of a knitted fabric.

10. Method according to the immediately preceding claim, in which the knit comprises a repetition of elementary cells, at least a part of said elementary cells being at least partially closed by at least one so-called closing thread, an elementary cell being defined as being the smallest rectangular pattern, which by its repetition forms 70%, or more, of the surface of the knit.

11. Method according to the immediately preceding claim, in which - more than 30% on average of the total surface area of ​​said elementary cells is closed by said at least one closing wire; and / or - more than 40%, preferably more than 90%, in number of elementary cells are at least partially closed by a closing wire, preferably by a set of closing wires, said closing wire or all of said closing wires together closing more than 30% of the total surface area of ​​said at least partially closed elementary cells; and / or - more than 30%, in number of elementary cells are at least partially closed by a sealing wire, preferably by a set of sealing wires, said sealing wire or all of said sealing wires together closing more than 50%, preferably more than 70% of the total surface area of ​​said elementary cells at least partially closed; and / or - more than 90%, in number of elementary cells are at least partially closed by a closing thread, preferably by a set of closing threads, said closing thread or all of said closing threads together closing more than 70% of the total surface area of ​​said at least partially closed elementary cells; and / or - the knit is made of a material chosen from a ceramic, a metal, an organic material, and their mixtures, preferably ceramic; and / or - the repetition of the elementary cell makes it possible to cover more than 85%, preferably more than 97% of the surface area of ​​the knit; and / or - the ceramic knit represents more than 5% and less than 25% of the mass of said textile element; and / or - the closing threads are oriented parallel to each other; and / or - a sealing wire, preferably each sealing wire is made of a material chosen from a ceramic, an organic product, and their mixtures, preferably a ceramic.

12. Method according to the immediately preceding claim, in which - the knit comprises, preferably consists of mesh yarn(s) comprising more than 95% by mass of oxides; and / or - a sealing yarn, preferably each sealing yarn comprising more than 95% by mass of oxides.

13. A method according to any preceding claim, wherein the stiffening element is made of a ceramic matrix composite and the textile element is made of a ceramic, the entire inner casing (32i) preferably being made of ceramic.

14. A method according to any preceding claim, wherein the stiffening element is in the form of a plate, grid, frame or bar.

15. A method according to any preceding claim, wherein, in step a), the stiffening element is removably attached to the textile element.

16. A method according to any preceding claim, wherein the stiffening element is fixed to the textile element so as to adopt a predefined position in the service configuration.

17. A method according to any preceding claim, comprising, after step b), a step 5) of sintering the repair product introduced into the mold in step b), the sintered repair product obtained being made up of a plurality of constituents, the content of any constituent of the sintered repair product present in a content greater than 5%, - differing by less than 20% from the content of said constituent in the stiffening element, and / or - differing by less than 20% from the content of said constituent in a region of the furnace delimiting the region to be repaired, and / or - differing by less than 20% from the content of said constituent in the textile element, the contents being in mass percentages on the basis of the oxides.

18. A method according to any preceding claim, wherein the inner formwork (32i) is left in the region to be repaired after said repair.

19. Method according to any one of the preceding claims, in which the stiffening element: - is made of a ceramic matrix composite, and / or - comprises through holes and / or recesses arranged so as to be filled by the repair product during step b), and / or - has the shape of a plate, flat or non-flat, the thickness of the plate being greater than 3 mm and less than 50 mm, preferably to form the bottom of a pocket defined by the textile element, and / or - is removable.

20. A method according to any preceding claim, wherein the interior formwork comprises accessories for holding the stiffening element in the service configuration, said accessories being made of a ceramic matrix composite, said ceramic matrix composite being identical to or different from the ceramic matrix composite of the stiffening element when the stiffening element is made of an identical ceramic matrix composite.

21. Method according to either of the two preceding claims, in which the ceramic matrix composite of the stiffening element and / or, when the preceding claim applies, the ceramic matrix composite of said accessory - is (are) sintered, and / or - is (are) made up for more than 90% of its mass of oxides, and / or - comprise(s) more than 20% and less than 80% by volume of fibers, and / or - comprise(s) fibers composed of more than 90% by mass of oxides, and / or arranged in the form of a textile, and / or - comprise(s) a matrix composed of more than 90% oxides by mass percentage, and / or - comprise(s) a matrix comprising A12O3 and / or SiO2 and / or ZrO2 and / or Cr2O3, and / or - have(s) a total SiO2+Al2O3+ZrO2+Cr2O3 content greater than 80%, as a percentage by mass based on oxides.

22. A method according to any preceding claim, wherein the interior formwork comprises: - a textile element, preferably made of a ceramic material, in the form of a pocket comprising a rear face (50a) which, in the service configuration, extends against and in contact with the wall to be repaired, a front face (50b), exposed towards the inside of the oven, two side faces (50c) joining the side edges of the front and rear faces, and a bottom face (50d), the pocket preferably comprising an excess length (54), preferably in the form of a tie, fixed, in step a), to the outside of the enclosure; And - a single stiffening element fixed to the pocket, preferably in a CMC, preferably in the form of a plate or several plates rigidly fixed to each other, preferably openwork, or one or more bars rigidly fixed to each other, preferably in the form of an I or a III, the upper and lower ends of the three vertical bars being rigidly connected by upper and lower bars, respectively, horizontal; or - a set of stiffening elements fixed to the pocket comprising: - a first stiffening element, preferably in a CMC, preferably in the form of a plate, preferably openwork, or a grid, fixed to the textile element so as to stiffen the front face (50b), preferably arranged in a housing (62b 622) defined by the textile element, and - a second stiffening element, preferably in a CMC, preferably in the form of a plate, preferably openwork, or a bar or an assembly of bars, preferably in the form of an I, fixed to the textile element so as to stiffen a lateral face (50c) from the pocket; Or - a plurality of stiffening elements, each stiffening element, preferably in a CMC, being in the form of a U-shaped frame and being fixed to the textile element, in the service configuration, so that the web of the U stiffens the front face (50b) and the two branches of the U stiffen the two side faces (50c), respectively, said stiffening elements in the form of a U-shaped frame being preferably horizontal and superimposed on each other, the web of the highest arranged U-shaped frame being preferably fixed to a tie, the other end of said tie being fixed to the side wall, preferably outside the enclosure.

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