METHOD FOR REPAIRING A GLASS MELTING FURNACE

Abstract

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. Abstract 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.l] schematically represents a half-cross section of a glass melting furnace 10. In particular, a tank 12, a metal structure 14 and a superstructure 16 can be seen.

[0003] The tank 12, intended to contain the molten glass, comprises 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 side wall, substantially vertical, surrounds the bottom.

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

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

[0006] In the remainder of the 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 interior surface of the enclosure, or "intrados" 29, and a surface opposite the intrados, called "extrados" 31. The side wall conventionally includes not only the refractory blocks which define the intrados, but also insulators and / or cladding pieces and / or a metal infrastructure surrounding the assembly of these blocks.

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

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

[0009] The refractory pieces used, typically in the form of blocks or slabs, are melted and cast pieces, or obtained by sintering. They are chosen according to the location where they are placed, so as to withstand local constraints and give the furnace a satisfactory lifespan. The choice is also guided by the need not to generate defects that would render the glass unusable, which would 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 the glass has been emptied and the furnace has cooled. A person can then enter the furnace to carry out the repair. Alternatively, the repair can be a so-called "hot" repair, preferably at more than 300°C, as a person cannot enter the furnace to carry out the repair.

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

[0013] A region to be repaired 30 may in particular result from wear of 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 does not generally arise for the repair of the sole.

[0014] The area to be repaired can sometimes pass through the furnace enclosure, putting the inside and outside of the furnace in fluid communication. Such a through area to be repaired can in particular lead to leaks of molten glass into the tank. 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 conventionally produced in order to produce, with the refractory part(s), a mold capable of retaining the repair product before it hardens. A region to be repaired is then partially delimited by one or more refractory parts of the furnace and partially by the formwork.

[0016] The formwork comprises a portion inside a furnace, where wear has occurred. It may also comprise a portion outside the furnace where wear has led to a passage through the furnace enclosure, in order to prevent the repair product from escaping outside the furnace. The outer portion of the formwork is conventionally a veneer. For the sake of clarity, the portions of the formwork inside and outside the furnace are referred to as "inner formwork" and "outer formwork", respectively.

[0017] [Fig. 2] illustrates an example of a conventional interior formwork 32i. This formwork comprises three adjacent panels 35i and 352 and 353 held in position by means of metal clamps 39, wedging 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 repairing therefore only requires a reduction limited temperature reduction, called "de-soaking", or even no temperature reduction, which considerably limits the duration of interruption of the furnace operation. The introduction of the formwork elements into the furnace can however lead to their degradation, under the effect of thermal shocks.

[0019] Furthermore, particularly for a hot repair, the interior of a furnace is difficult to access, which makes it difficult to create the internal formwork for certain regions to be repaired. In particular, the introduction of the internal formwork elements may require passages to be made through the furnace enclosure. Furthermore, during a hot repair, no operator can enter the furnace. The installation of the internal formwork must therefore sometimes be carried out at a distance from the region to be repaired. The size and weight of the internal formwork elements can therefore considerably slow down the creation of the formwork.

[0020] These constraints also make it very difficult to create an interior formwork of complex shape, in particular when the region to be repaired projects towards the interior of the furnace.

[0021] After installation of the formwork, the mold is filled with repair product, conventionally by means of a pump. During a hot repair, the repair product undergoes a sudden increase in temperature when entering the mold, resulting in particular in a reduction in its ability to flow. It is therefore difficult to fill the mold evenly.

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

[0023] After the repair product has hardened, the removal of the formwork leaves room for reconstituted refractory parts. Generally, however, metal formwork does not allow the original shapes to be reconstituted if they are complex. The temperature can then be increased to restart the furnace, during an operation called "tempering".

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

[0025] JP03-140793 describes an interior formwork for the repair of a side wall of blast furnace. This formwork consists of vertical plates rigidly attached 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 advantageously prevents leaks into the furnace.

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

[0027] These rods must also be sized to hold the plates and be fixed precisely to the plates and to the wall to be repaired.

[0028] There is a continuing need for glass melting furnace repair solutions that address the above-mentioned problems, particularly allowing rapid return to production of the furnace without degrading 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 region to be repaired extending on the intrados of a side wall of the enclosure of a glass melting furnace, said method comprising the following steps: a) installation of an interior formwork comprising, or even consisting of, a flexible textile element and a stiffening element intended to stiffen the interior formwork, so as to create a mold around the area to be repaired; b) filling the mold with a repair product 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 thrust exerted by the repair product towards the interior of the oven.

[0033] As will be seen in more detail in the remainder of the description, the absorption, at least in part, preferably in full, of the thrust of the repair product by the textile element advantageously makes it possible to simplify the assembly of the internal formwork, which is particularly useful for hot repair. It also makes it possible to limit, or even eliminate, the need for rigid fixings between the oven 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 on a surface of the furnace other than the intrados of the side wall of the furnace enclosure, preferably on the extrados of the side wall of the enclosure.

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

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

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

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

[0039] Preferably, the textile element has the shape of a pocket having a first large face, called the “rear 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 rear face.

[0040] Preferably, the pocket comprises a second large face, called the “front face”, opposite the first large face, i.e. exposed towards the inside of the oven, and the pocket preferably comprises 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 also comprise one or more of the following optional and preferred characteristics: - during steps a) and b), the region 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 one part of which is impervious to the repair product, the part impervious to the repair product preferably comprising at least one front face of the pocket; - the pocket comprises a portion permeable to the repair product, the portion permeable to the repair product preferably comprising 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 pouch exposed towards the inside of the oven, the pouch being able (or not) to be impervious to the repair product; - a pocket defined by the textile element is partitioned so as to define a plurality of boxes, and 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, said boxes preferably being sealed against the repair product; - the textile element is made of a material chosen from a ceramic, a metal, an organic material, and their mixtures, preferably a ceramic; - the textile element defines at least one tie, and, in step a), the tie 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, a tension being exerted on the tie, from outside the oven, so as to pull on the stiffening element; - 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; the rest of the surface of the knit can be occupied in particular by singular points, which can conventionally exist in a knit, such as for example increases (simple or baguettes), decreases (simple or baguettes), arrows, selvedges, networks or chains; - more than 30% on average of the total surface area of ​​said elementary cells is closed by said at least one closing wire; - 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 elementary cells at least partially closed; - more than 30%, 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 50%, preferably more than 70% of the total surface area of ​​said elementary cells at least partially closed; - 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 70% of the total surface area of ​​said elementary cells at least partially blocked; - the knit is made of a material chosen from a ceramic, a metal, an organic material, and their mixtures, preferably ceramic; - the repetition of the elementary cell makes it possible to cover more than 85%, preferably more than 97% of the surface of the knit; - 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 their mixtures, preferably a ceramic; - the knit comprises, preferably is made of, mesh yarn(s) comprising more than 95% by mass of oxides; - a sealing wire, preferably each sealing wire comprising 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 interior 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 method comprises, after step b), a step 5) of sintering the repair product introduced into the mold in step b); - the sintered repair product obtained is 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 based on the oxides; - the internal formwork is left in the area to be repaired after said repair, i.e. it is not removed before the furnace is put back into operation; - the stiffening element - is made of a ceramic matrix composite, and / or - has through holes and / or recesses arranged 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; - the interior formwork comprises a plurality of stiffening elements arranged, in the service configuration, so that after the repair product has hardened, the repaired wall has the same shape as it initially had, i.e. before being worn; - the internal formwork comprises accessories for holding the stiffening element in the service configuration, said accessories preferably 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; - the ceramic matrix composite of the stiffening element and / or said accessory - is (are) sintered, and / or - is (are) made up of more than 90% of its mass of oxides, and / or - contain(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 Al2O3 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 the oxides.

[0042] In particularly preferred embodiments, the interior formwork comprises: - a textile element, preferably made of a ceramic material, in the form of a pocket comprising 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 interior of the furnace, two side faces joining the side edges of the front and rear faces, and a bottom face, the pocket preferably comprising an excess length, preferably in the form of a tie, preferably a strip, 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 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 and 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, preferably arranged 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 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 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 branches 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 on each other, the web of the uppermost 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 characteristics, optional or not, of the different main aspects of the invention can be combined, to the extent that they are technically compatible.

[0044] The invention also relates to an interior formwork intended for implementing a method 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 method according to the invention. Brief description of the figures

[0046] Other characteristics and advantages of the invention will become apparent upon examination of the description which follows and with regard to the appended drawing in which: - [Fig. 1] [Fig. 1], described in the preamble, schematically represents a half-cross section of a glass melting furnace, before wear; - [Fig.2][Fig.2] schematically represents an example of formwork conventional; - [Fig.3][Fig.3] schematically represents a method according to the invention; - [Fig.4][Fig.4] represents an example of a stiffening element in the form of a plate and comprising through holes; - [Fig.5] [Fig.5] schematically represents an example of texture for a knit that can be used 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 threads and usable as a textile element; - [Fig.8] [Fig.8] schematically represents the texture of the knitting of [Fig.7]; - [Fig.9][Fig.9] represents a zoom of the knitting of [Fig.7], which in particular allows the description of the surfaces SI and S2 allowing the calculation of the shutter rate; - [Fig. 10][Fig. 10] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig. 11][Fig. 11] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig. 12] [Fig. 12] schematically represents different examples of formwork according to the invention, in the service configuration; - [Fig. 13][Fig. 13] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig. 14][Fig. 14] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig. 15][Fig. 15] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig. 16][Fig. 16] schematically represents an example of a formwork according to the invention, in the service configuration; - [Fig.l7][Fig.l7] schematically represents an example of a formwork according to the invention, in the service configuration. In the various figures, identical references are used to designate identical or similar parts. Definitions

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

[0048] It results from an assembly of one or more "formwork elements" and a positioning of the assembled formwork element(s). The part of the mold defined by the formwork is completed with a part of the interior surface of the oven and / or a part of the textile element which extends against the intrados (interior surface) of the wall, so as to constitute the mold. The relative position of the different elements of The formwork may vary during filling, due to the thrust exerted by the repair product. The "service configuration" is the shape adopted by the formwork at the end of filling.

[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 comprise "accessories", used to assemble and fix the formwork elements, and which are not in contact with the repair product during the repair. Unlike accessories, formwork elements are parts which come into contact with the repair product during the repair.

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

[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 surface area as its cross-section at mid-length.

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

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

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

[0055] A “fabric” consists of a network of parallel warp threads and weft threads crossing transversely said network.

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

[0057] A “knit yarn” is the yarn forming all or part of the stitches of the knitted fabric. A knitted fabric may comprise a single knit yarn, in particular when said knitted fabric is manufactured using a weft knitting method. A knitted fabric may also comprise several knit yarns, in particular when said knitted fabric is manufactured using a warp knitting technique.

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

[0059] A “sheet” is made up 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 holes capable of being crossed by the repair product. Preferably, the interstices between the threads or fibers which constitute the veil do not form such holes, so that a veil can constitute a waterproof barrier to the repair product.

[0061] A “net” is a textile, woven or non-woven, for example knitted, which, unlike a veil, has orifices capable of being passed through by the repair product. The cumulative surface area of ​​these orifices 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 orifices.

[0062] A textile may have the shape of a “pocket”. A pocket defines a cavity, in particular intended to receive one or more stiffening elements and / or repair product. A pocket may in particular be formed 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 makes it possible to fold or roll the textile element on itself, preferably by hand, preferably without an instrument.

[0064] A “tie” has a length typically greater than twice its width. A tie may in particular be in the form of a cord, a rope, a strip, or a cable. In one embodiment, a tie, preferably each tie, is rigidly attached to at least one stiffening element, in particular a plate, made of CMC during its manufacture of the CMC. The tie is thus integrated into the stiffening element, which avoids the need for an additional fastening means. In another embodiment, a tie is glued 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 substantially changed during filling with the repair product. Several stiffening elements may be connected to each other by hinges. Two pieces rigidly fixed to each other to stiffen the formwork interior form a single stiffening element.

[0066] Each stiffening element is preferably in a CMC.

[0067] By “Ceramic Matrix Composite”, or “CMC”, we conventionally 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 remainder to 100% being the matrix.

[0069] Generally speaking, when referring 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 previous sentence), the volume to be considered is that of the object defined by its external surface, that is to say it includes the empty spaces inside the object.

[0070] By "ceramic" is meant 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 respecting one of the following formulas: - SixAlyOuNv, 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 and normalized with respect to the one which is the highest, 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 passes through the furnace enclosure, thus connecting the interior and exterior of the furnace.

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

[0075] A dry particulate mixture is conventionally called an “unshaped product”.

[0076] By product “in a material” or “of a material”, we mean 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 temperature greater than 1500°C. This definition is commonly used by those skilled in the art and cited in "Refractory materials and technical ceramics (elements of ceramurgical and technology)", G. Aliprandi, Septima Paris editions, 1979. This work also gives on pages 297 to 301 examples of refractory materials, in particular oxides, carbides and nitrides.

[0078] By "glass transition temperature" of a glass is meant the temperature at which said glass passes from the solid state to the viscous state. The glass transition temperature can be determined by differential thermal analysis (DTA). The glass transition temperature is the temperature at which said glass has a viscosity substantially equal to 1012 Pa.s. A glass is conventionally considered "in the solid state" at a temperature lower than its glass transition temperature.

[0079] By "hot binder" is meant a constituent having a melting temperature 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 term "maximum size" refers to the 99.5 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 particles, the particle sizes being classified in ascending order. The particle size distributions and the maximum size can be determined using a laser granulometer. The laser granulometer can be a Partica LA-950 from HORIBA.

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

[0082] Unless otherwise indicated, the “repair product” is the product before it has hardened. It is preferably self-flowing, i.e. capable of spreading under its own weight, and of filling the mold without leading to segregation.

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

[0084] AZS products are products, preferably electrocast, whose main constituents are alumina (A12O3), zirconia (ZrO2) and silica (SiO2). In other words, alumina, zirconia and silica are the constituents with the highest mass contents. These products are well suited for the manufacture of glass furnaces. More particularly, current AZS products are mainly used for the regions 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 or ER-1711.

[0085] When reference is made to ZrO2 or zirconia, it is appropriate to understand ZrO2 and traces of HfO2. Indeed, a little HfO2, chemically inseparable from ZrO2 in a fusion process and having similar properties, is always naturally present in zirconia sources at contents generally less than 2%. Hafnium oxide is then not considered an impurity. The HfO2 content in the AZS particles is preferably less than 5%, less than 3%, less than 2%.

[0086] Unless otherwise stated, all percentages are mass percentages based on the oxides. A mass content of an element is expressed in the form of the 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 movement 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 housing defined by the textile element.

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

[0089] Preferably, the textile element is rigidly fixed to the stiffening element by at least two points, preferably at least three points, aligned or non-aligned.

[0090] Unless otherwise indicated, a binding may or may not be rigid. A binding between two parts can be direct, with both parts in contact with each other in the attachment area, or indirect.

[0091] “Behave” or “understand” or “present” must be interpreted non-limiting manner. Detailed description

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

[0093] A flexible textile element can be deformed. It is thus advantageously easy to introduce into the oven, for example in rolled form, then deformed to take 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 the service configuration.

[0094] According to a main aspect of the invention, the internal formwork is configured so that, in the service configuration of the internal formwork, the textile element is rigidly fixed to the oven, preferably to the wall to be repaired, and in contact with the stiffening element so as to take up, at least partially, preferably completely, the thrust exerted by the repair product on the internal formwork. In other words, the textile element, fixed to the oven, can oppose the forces exerted by the repair product on the stiffening element. It participates in 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 relative to the wall to be repaired. This makes it easier to install the interior formwork.

[0096] Preferably, the stiffening element is maintained in the service configuration without being rigidly fixed to the oven, and in particular to the wall to be repaired. It can in particular be maintained in the 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 zone). The use of a textile element offers numerous possibilities for fixing the interior formwork to the wall to be repaired. In particular, the flexibility of the textile element allows it to be positioned easily, in particular to fix it in an easily accessible area, without damaging the intrados of the wall to be repaired.

[0098] The attachment of the stiffening element to the textile element allows the latter to participate in the positioning of the stiffening element when the textile element is put into service configuration and preferably rigidly attached to the wall to be repaired. Preferably, the attachment, rigid or not, of the stiffening element to the textile element is adapted so that, when the textile element is in the service configuration, the stiffening element, preferably each stiffening element, has a predefined position. The installation of the interior formwork is considerably simplified, which is particularly advantageous for a hot repair.

[0099] Preferably, the textile element is, before filling the interior formwork with the repair product, fixed to the wall to be repaired and retains the stiffening element. Preferably, the textile element is configured to oppose 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 leaks into the interior of the oven.

[0101] According to a main aspect of the invention, the textile element is shaped so as, in the service configuration, to extend partly outside the enclosure. The portion of the textile element outside the interior space of the oven, 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 an upper opening intended for the introduction of the repair product into the pocket. The pocket may have, when flat, 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 (dimension of the side of the opening of the pocket which, in the service configuration, is supported on the wall to be repaired), preferably taking 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 manipulations for removing the excess length from the oven enclosure, then attaching it are simplified.

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

[0105] The excess length may pass through the side wall, preferably outside the region to be repaired, through any passage created for this purpose or preferably pre-existing, preferably through a sight glass, in particular a burner sight glass, or by a viewing block provided for observing the interior of the furnace in operation.

[0106] The links, preferably the bands, may extend, in the service configuration, to an altitude lower than the altitude of the opening of the pocket. The weight and bulk of the pocket are advantageously reduced.

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

[0108] The textile element preferably defines a pocket, preferably has the shape of - a pocket, preferably of a substantially parallelepipedal general shape in the service configuration, and / or of a veil and / or of a net, or - of a band.

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

[0110] Preferably, the textile element is impervious to the repair product when the formwork is filled with repair product. Preferably, the textile element is a web of which at least a portion is impervious to the repair product and shaped to form, in the service configuration, at the end of filling, an interface between the interior 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 interior formwork in contact with the interior of the furnace in the service configuration.

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

[0113] More 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 made of a ceramic material, preferably made of alumina and / or silica and / or an 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 of a knit.

[0117] Knitting advantageously makes it possible to obtain a wide variety of shapes without the need for seams. This results in better control of the absorption of forces exerted by the repair product, as well as a lower manufacturing cost.

[0118] The knit is preferably made of a material chosen from a ceramic, a metal, an organic material, and mixtures thereof. Preferably, the knit is made of ceramic, in particular 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 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.

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

[0121] Preferably, more than 40%, preferably more than 50%, preferably more than 60%, preferably more than 70%, preferably more than 80%, preferably more than 90%, preferably more than 95%, preferably substantially 100% in number of the elementary cells of the knit are at least partially closed by a closing thread, preferably by a set of closing threads, preferably unidirectional.

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

[0123] In particular, said sealing wire or all of said sealing wires together preferably seal(s) more than 40%, more preferably more than 50%, more preferably more than 60%, more preferably more than 70%, more preferably more than 80% of the total surface area of ​​said at least partially sealed elementary cells.

[0124] Preferably, more than 40%, preferably more than 50%, preferably more than 60%, preferably more than 70%, preferably more than 80%, preferably more than 90%, preferably more than 95%, preferably substantially 100% in number of the elementary cells of the knit are at least partially closed by a closing thread, preferably by a set of closing threads, preferably unidirectional, said closing thread or all of said closing threads together closing more than 30%, preferably more than 40%, preferably more than 50%, preferably more than 60%, preferably more than 70%, preferably more than 80% of the total surface area of ​​said at least partially closed elementary cells.

[0125] The ceramic knit comprises, preferably consists of, mesh yarn(s) chosen from: - one or more mesh threads 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 threads 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 threads 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 threads 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 threads 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 yarns.

[0126] The ceramic knit comprises, preferably consists of, mesh yarn(s) chosen 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. Preferably, said mesh thread(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 chosen 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 having 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%, in 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 having a chemical analysis such as SiO2 > 70%, preferably 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 having a chemical analysis such that A12O3 > 65%, preferably Al2 O3 > 70%, or even A12O3 > 80%, or even A12O3 > 90%, or even A12O3 > 95%, as a percentage by mass, - and their mixtures.

[0127] More preferably, at least a portion, preferably said yarn or said mesh yarns 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 threads 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 wires 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 wires 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 threads 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 substantially 100% by mass of boron carbide, - and their mixtures.

[0129] 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 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 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 knit 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 makes it possible 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 knit, the remainder being occupied by singular points, which can conventionally exist in a knit, such as for example increases (simple or baguettes), decreases (simple or baguettes), arrows, selvedges, networks or chains.

[0134] The knit 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 stitch 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 wires

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

[0137] The sealing thread may be a filler, a float, a unidirectional thread, preferably a unidirectional thread.

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

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

[0140] Preferably the sealing thread, preferably each sealing thread, 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 thread, preferably each sealing thread, is inserted into the stitches of the sealed elementary cells of the knit, preferably by depositing and trapping in the stitches, without being taken up by the stitches.

[0142] The number of sealing thread(s) sealing the elementary cells is a function of the surface area of ​​said elementary cell and the linear mass of the sealing thread(s). Preferably, the sealing threads are oriented parallel to each other and preferably in the direction of the rows or columns of mesh.

[0143] In one embodiment, a sealing thread, preferably each sealing thread, is made of a material identical to the material of the mesh threads of the knit.

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

[0145] A sealing wire, preferably each sealing wire, is made of a material selected from a ceramic, in particular 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 sealing wire, preferably each sealing wire, is selected 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 having 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 having a chemical analysis such as SiO2 > 70%, preferably SiO2 > 80%, preferably SiO2 > 90%, or even SiO2 > 99%, 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 having a chemical analysis such that A12O3 > 65%, preferably A12O3 > 70%, or even A12O3 > 80%, or even A12O3 > 90%, or even A12O3 > 95%, as a percentage by mass.

[0149] More preferably, at least a portion, preferably said sealing wire or wires 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 wires 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 wires 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 threads 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 substantially 100% by mass of boron carbide, - and their mixtures.

[0151] 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 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, said mesh 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 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: - said mesh yarn(s) of the knit 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, closure 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;- said mesh yarn(s) of the knit 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 glass, preferably washed; ; - said mesh yarn(s) of the knit 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; - said mesh yarn(s) of the knit 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, said mesh 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 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 said mesh yarn(s) of the knit 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 said mesh yarn(s) of the knit are in one 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, said mesh yarn(s) of the knit 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 may be manufactured according to techniques known from the prior art. In particular, it may be manufactured by simultaneously knitting a plurality of mesh yarns and / or a plurality of closure yarns. The stitches of the knitted fabric may thus be formed from a plurality of mesh yarns. Similarly, a plurality of closure yarns may be introduced into the knitted fabric. All combinations are possible, for example a plurality of mesh yarns with a single closure yarn, but also a plurality of closure yarns with a single mesh yarn, or a plurality of mesh yarns with a plurality of closure yarns.

[0159] Preferably, the textile element comprises several layers of knitting, preferably consists of several layers of knitting, at least one of which is a knitting incorporating a sealing thread, 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 even consists of, several knits, preferably arranged in layers.

[0161] In one embodiment, the textile element is made using several pockets inserted into one another. Preferably, each of the pockets is made of a knit. Preferably, each pocket comprises a set of sealing threads, preferably unidirectional threads, more preferably unidirectional threads in a different direction from one pocket to another, preferably in a 90° direction from one pocket to another.

[0162] The introduction of at least one sealing thread into the elementary cells of a knitted fabric 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- or U-shaped and a bar.

[0164] Preferably, the formwork comprises a stiffening element, for example in the form of a bar, which preferably extends substantially in a vertical plane in the service configuration, preferably which does not extend along an edge of the formwork in order to avoid the formation of a sharp edge, 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 perpendicular to the wall to be repaired may in particular serve to separate 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 shape of a formwork plate, flat or non-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 may in particular be a plate substantially parallel to the wall of the furnace to be repaired, or a plate perpendicular to the wall of the furnace to be repaired, in particular at the ends of the region 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 one strip, preferably several ties, preferably several strips, made of a textile are fixed to the stiffening element, for example a formwork plate or a frame, preferably open, preferably by gluing or integrated into the stiffening element during the manufacture thereof, in particular if the stiffening element is made of a CMC. For example, at least two ties, preferably two strips, can be fixed on the top of the formwork plate, preferably at least two ties, preferably two strips can be fixed on the top of the formwork plate and at least two ties, preferably two strips can be fixed on the bottom of the formwork plate. The ties, preferably the strips, can be attached to the outside of the enclosure and serve to hold the stiffening element in position, and in particular to retain the formwork plate.

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

[0172] In a preferred embodiment, the formwork plate is disposed inside of a pocket, without being rigidly fixed to the textile element. Preferably, the shape of the pocket is substantially that of the formwork plate, which makes it possible to effectively hold the formwork plate. The pocket can be replaced, in a substantially equivalent manner, by strips which at least partially encircle the formwork plate.

[0173] It is in particular possible to fix one or more formwork plates on a pocket, on a canvas, on a net or on one or more strips. The assembly thus formed can be deformed to facilitate its introduction into the furnace, then deployed in the furnace to reach the service configuration. The textile element limits the relative positions of the formwork plates with respect to each other, which greatly facilitates deployment.

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

[0175] The internal formwork preferably comprises a “bottom” stiffening element, i.e. 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 bottom stiffening element preferably rests on the floor of the furnace in the service configuration. Advantageously, it facilitates the positioning of the formwork relative to the wall to be repaired. The bottom stiffening element is preferably fixed or placed on the bottom of a pocket or sleeve defined by the textile element, preferably on the bottom of a pocket 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 bottom stiffening element, comprises through holes and / or recesses, as illustrated in [Fig.4]. Filling these holes and recesses with the repair product during step b) advantageously allows better immobilization of the formwork, allows the thermal gradient in the repair product during the sintering step 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 preferably being distributed homogeneously, the total surface area of ​​the holes representing more than 10%, preferably more than 15% and preferably less than 80%, preferably less than 70% of the surface area of ​​said stiffening element delimited by its perimeter, i.e. the surface area participating in the definition of the mold around the region to be repaired (surface area of ​​the holes and of the material of the grid).

[0181] The provision of through holes and / or recesses may be carried out by any technique known to those skilled in the art. In particular, through holes may be made by drilling or cutting under a water jet, for example on ceramic, preferably in the form of a CMC, obtained after sintering. In a CMC, the through holes and / or recesses may also be made on the textile, preferably a woven fabric, before coating with the slip.

[0182] The stiffening element is preferably fixed to 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 may be fixed to the textile element, preferably sewn, with holes preferably being provided for this purpose in the stiffening element, or glued to the textile element, integrated into the textile element, in particular when the stiffening element is in a CMC, or wrapped by the textile element, for example housed in a sheath or in a pocket defined by the textile element, or inserted into the thickness of the textile element. The fixing may be ensured by one or more fixing points, preferably at least three fixing points, and / or by one or more fixing lines, or even by a fixing surface, for example with a surface greater than 5 cm2.

[0184] Preferably, the stiffening element is removable, i.e. it can be detached from the textile element without breaking a part of the formwork, for example without breaking a glue point or a sewing thread. Preferably, the stiffening element is removable by hand, preferably without an instrument, preferably reversibly.

[0185] The removability advantageously makes it possible to obtain modular formwork. The formwork can in particular be easily adapted depending on the region 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 from each other by more than 10 cm and / or less than 50 cm, preferably less than 40 cm, the textile element preferably comprising a pocket on which the stiffening elements are fixed.Bars may form a stiffening element in the form of a frame, preferably open, or a grid which, combined with a textile element forming an interface between the interior of the furnace (i.e. the space defined by the furnace enclosure) 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 made of a ceramic, preferably an oxide, preferably the total content SiCL+AhOï+ZiLL+CiyOïC being greater than 80%, preferably greater than 90%, preferably greater than 95%, in percentage by mass based on 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 makes it possible to produce a formwork that does not need to be cooled. This formwork can therefore be lighter (particularly if it is made with thin plates). In addition, due to the absence of cooling, this interior formwork is very quick to install.

[0190] Furthermore, a ceramic, particularly in the form of a CMC, does not substantially alter the quality of the glass produced when it is brought into contact with molten glass or with the corrosive vapors present in the furnace, and therefore does not require removal of the inner formwork 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 quantity of defects in the glass, is advantageously possible.

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

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

[0193] In addition, a CMC is highly resistant to thermal shocks, which allows 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 include the following steps: (i) provision, 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 threads extending substantially parallel to one another (said threads being called “unidirectional threads”), 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 sheet or a stack of felt(s) and / or sheet(s) and / or fabric(s). The stacking of the fabrics and / or sheets can be carried out in such a way that the threads of the different fabrics or sheets extend substantially all in the same direction, or in 2, 3, 4, 5 or 6 different directions, depending in particular on the desired mechanical properties.

[0197] Preferably, at least a portion, preferably all of the fibers of the textile optionally assembled in the form of single and / or assembled threads, are fibers made of 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 fibers have the same composition.

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

[0200] The manufacture of slip is well known to those skilled in the art. Slip is conventionally a suspension, for example of an aqueous base or an organic solvent, containing: - ceramic particles and / or precursors of ceramic particles, i.e. compounds which 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 filler of the slip are adapted to the type of fibers and the shaping technique. For example, the slip can be placed on or in the textile, in particular by direct lamination, by infusion, injection, infiltration or deposition, under atmospheric pressure or under higher pressure or under vacuum, at room temperature or at higher temperature.

[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 textile obtained, preferably impregnated with the slip, is shaped. The desired shape is preferably the final shape of the CMC. In one embodiment, the shape can however be modified after hardening of the matrix, for example by machining or by deformation.

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

[0205] The 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, consists 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, in particular in the form of a CMC, with the molten glass during normal operation of the furnace is advantageously improved.

[0207] Preferably, in said ceramic, preferably in the form of a CMC, the total content of SiO2+A12O3+ZrO2+Cr2O3 is preferably greater than 80%, preferably greater than 90%, preferably greater than 95%, in mass percentage based on the oxides.

[0208] More preferably, - 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% of oxides, in 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% of oxides, in 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 SiO2+Al2O3+ZrO2+Cr2O3 is preferably greater than 80%, preferably greater than 90%, preferably greater than 95%, in percentage by mass based on the oxides. Accessories

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

[0210] The formwork may comprise accessories made of a ceramic, preferably in the form of a CMC, said formwork elements and accessories preferably not being cooled, and in particular not being cooled using 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, in particular for the repair of a tank initially containing a bath of molten glass in contact with the region to be repaired, the repair method comprises the following steps: 1) if the region to be repaired is, at least partially, delimited by a surface of the furnace tank in contact with the bath of molten glass, emptying, at least partially, said molten glass from the tank, so as to expose said region to be repaired; 2) optionally but preferably, rinsing the area to be repaired to remove glass residue; 3) reducing the temperature in the furnace 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 increasing the temperature of the furnace 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 the solid state. In particular, when the hot binder is a glass, the temperature in the furnace is reduced to a temperature which 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] In step 4), the formwork is installed by assembling its elements.

[0215] In step a), the installation of the interior formwork is delicate given the dif access difficulties.

[0216] The flexible textile elements can advantageously be 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 region to be repaired is filled with a repair product, preferably by pouring. 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 the humidification of an unshaped product. Said humidification can be carried out according to any known technique, for example in a mixer. The person skilled in the art knows how to determine the quantity of solvent, preferably water, to be used to humidify the unshaped product and obtain the repair product.

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

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

[0223] Preferably, the maximum particle size of the repair product or, 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 self-flowing when hot.

[0225] Preferably, the repair product is chosen so as to present an analysis chemical close to that of the furnace material which delimits the region to be repaired, preferably such 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 region to be repaired is delimited by one or more refractory blocks made of an AZS (Alumina Zirconia Silica) product, the unshaped product for manufacturing the repair product is preferably Repair Hot Overcoat AZS, depending on the location of the region to be repaired in the glass melting furnace. If the region to be repaired is delimited by one or more refractory blocks made of an AZS-Chrome product, the unshaped product for manufacturing the repair product is preferably Repair Hot Overcoat Chrom50. Finally, if the region to be repaired is delimited by one or more refractory blocks made of a silica product, the unshaped product for manufacturing the repair product is preferably Repair Hot Overcoat Fused Silica.

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

[0229] Throughout step b), the region 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 method 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 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] In step 6), normal operation of the furnace is resumed: A glass composition to be melted is introduced into the furnace and, if said method 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 with a view to 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 jersey-type gathered knit Tl made of Quartzel® yarns having a weight equal to 120 g / m2, a row density equal to 3.43 rows per centimeter and a column density equal to 2.1 columns per centimeter, of rectangular shape with a length equal to 300 mm and a 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] [Fig.6] is a representation of a knit Tl in which the reference 1 represents the Quartzel® threads and in which the elementary cell of this knit is illustrated by the dotted rectangle SL

[0237] Figures 7 and 8 illustrate a knit T2 identical to the knit T1 but incorporating sealing threads, represented in [Fig.7] by gray lines 2, said sealing threads being Quartzel® threads 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 threads being trapped in said stitches.

[0238] The total weight of each knitted support is equal to 1000 g / m2 for a mesh density equivalent to that of the T1 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 S2 occupied by all the Quartzel® sealing threads in the elementary cell and the surface SI of the elementary cell previously described, as illustrated in [Fig.9]. For the T2 knit, it is thus calculated that 59% of the total surface of the elementary cells is sealed by the sealing threads. In this example, 100% (in number) of the elementary cells are sealed by said threads.

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

[0242] The textile element 50 comprises an excess length 54 which is fixed to the outside of the enclosure, preferably on the extrados. The fixing is preferably carried out by winding, for example around a cleat, 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 (large arrow). It exerts a thrust P, symbolized by a horizontal arrow, on the stiffening element 52. The stiffening element opposes this thrust P by a reaction force R on the stiffening element 52 opposite and of the same value.

[0244] The inner formwork 32 may optionally comprise a bar 58, preferably made of ceramic, preferably 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 the pocket, so as to oppose, with the textile element, the thrust exerted by the repair product towards the inside of the furnace, that is to say so as to pull the upper part of the plate or the pocket towards the intrados of the wall to be repaired. The bar 58 may also be used to keep the pocket open during filling.

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

[0246] As illustrated in [Fig.l 1], the stiffening element can be immobilized on the pocket in a predefined position, for example inserted in a housing, preferably of substantially complementary shape, for example in the form of a pocket. In [Fig. 11], in an embodiment which is not preferred, 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 in housings 62i and 622, respectively.

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

[0248] Figure 12A shows a textile element 50 whose “rear face” 50a is in one textile 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 T1 knit 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 T2 knit described above. This embodiment allows good adhesion of the repair product to the wall to be repaired, avoiding leaks into the interior of the oven before hardening.

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

[0250] In Figure 12C, the inner formwork 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 side face of the pocket, three superimposed stiffening elements, regularly spaced, 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 comprises a stiffening element in the form of a substantially vertical plate, for stiffening the front face of the pocket exposed inside the furnace. In the illustrated embodiment, the plate is outside the pocket and is inside a housing defined by a horizontal strip 65h whose ends are fixed to the pocket and a vertical strip 65v whose ends are fixed to the horizontal strip and to the pocket.

[0252] In Figure 12E, the inner formwork comprises a stiffening element in the form of a substantially vertical plate, for stiffening the front face of the pocket exposed inside the furnace, and, for each side 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 comprises two excess lengths in the form of ties, preferably strips.

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

[0254] In Figure 13A, the formwork comprises several textile elements having the shape of pockets 50b 502, each containing a plate, 52b 522, respectively, the pockets being arranged adjacent to each other or separated by an independent plate 523, i.e. not arranged in a pocket. The independent plate is preferably arranged so as to rest, in the service configuration, on the adjacent plates fixed, preferably rigidly, on two pockets arranged on each side of the independent plate. Preferably, the adjacent plates serve as a stop to prevent the independent plate from moving towards the inside 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 independent plate- pendant 523 is housed in folds 72 formed by pockets 50i and 502.

[0257] [Fig. 14] illustrates a particularly advantageous embodiment. The formwork comprises a textile element in the form of a pocket, preferably made of a knit, 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 open towards the wall to be repaired.

[0258] Preferably, the frames extend horizontally in the service configuration, preferably spaced from each other by a distance d of 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 sheath or by sewing. Preferably, the core of the uppermost U-shaped frame is fixed to a tie forming an overlength 54, the other end of said tie being fixed to the side wall, preferably outside the enclosure. More preferably, the core of each other U-shaped frame is fixed 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 parallelepipedal in the service configuration, provided with excess 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 stiffening element in the shape of a III (3 in Roman numerals) which stiffens the face of the pocket exposed inside the furnace, and, for each side of the pocket, a stiffening element in the shape of an I, 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 stiffening element in the shape of a III is not connected to the stiffening elements in the shape of an I.

[0262] Preferably, no vertical bars extend along the edges, which makes it possible to avoid sharp corners.

[0263] The textile element comprises two excess 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 interior formwork may comprise several modules such as that shown in [Fig. 15], arranged side by side, adjacently. Preferably, stiffening elements in the form of an I are however not arranged only on the lateral faces at the lateral ends of the interior formwork. In other words, no I-shaped stiffening element is arranged at the interface between two adjacent pockets.

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

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

[0268] Preferably, the boxes, or "inter-box walls" extend substantially vertically, and more preferably substantially perpendicular to the side wall. The shape and structure of the boxes is preferably determined to create reinforcements along lines of force, so that the weight of the repair product gives a predefined 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 juxtaposed bags or pouches, the boxes interact with each other to give a predefined shape in the service configuration. In addition, it is not necessary to fix each pouch to the oven, which limits costs. The partitions 74 can finally form a mechanical reinforcement frame after hardening.

[0271] In one embodiment, as illustrated in [Fig. 16], the textile element comprises at least one central box 503' and two lateral boxes 50i' and 502', adjacent to the central box. The rigidity of the central box can then be obtained by that of the lateral boxes, in particular after filling the latter with repair product. In particular, the front face of the central box exposed inside the oven can be devoid of a stiffening element, as illustrated.

[0272] [Fig. 17] illustrates an interior 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 traction of which a component R opposes the thrust exerted by the repair product on the plate. It advantageously exerts an action equivalent to the wedging brick 60 shown in [Fig.l] and generally difficult to position, in particular for a hot repair.

[0273] The tie, preferably the band, is fixed to the outside of the enclosure, while 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 towards the inside of the furnace 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 furnace.

[0275] As now clearly appears, the invention provides a formwork and a method of repairing a glass melting furnace using this formwork which: - facilitate the introduction of formwork elements into the oven, in particular by folding or rolling up the textile elements; - allow quick and simple installation, in particular since the textile element can be easily fixed outside the intrados of the side wall to be repaired; - facilitate the arrangement of stiffening elements, in particular when they are fixed to textile elements; - allow a sacrifice of the formwork elements, i.e. their retention in the furnace 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 as illustrative and non-limiting examples.

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

[0278] The detailed description generally mentions a textile element and a stiffening element to improve 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 features optionally 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 interior formwork may comprise several textile elements, only some of which are fixed, preferably rigidly, to the oven.

[0280] All the stiffening elements are also not necessarily identical and / or used in the same way. For example, the interior formwork may comprise several stiffening elements, only some of which are fixed, preferably rigidly, to a textile element.

[0281] Preferably, the interior formwork 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 preceding claim, 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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