Crosslinking oven comprising an electric heating means arranged in the combustion chamber

Abstract

The present invention relates to an oven (2) for crosslinking a mat (16) of mineral and / or plant fibres, comprising at least one combustion chamber (4), at least one burner (14) configured to generate a flame inside the combustion chamber (4) and a crosslinking enclosure (6) which is configured to receive the mat (16) and is aeraulically connected to the combustion chamber (4), the oven (2) comprising at least one electric heating source (18) for heating the crosslinking enclosure (6), characterised in that the electric heating source (18) is arranged inside the combustion chamber (4).

Description

CROSSLINKING OVEN COMPRISING AN ELECTRIC HEATING MEANS ARRANGED IN THE COMBUSTION CHAMBER 5

[0001] The present invention relates to the field of crosslinking ovens and more particularly to the heating of mineral and / or plant fiber mats.

[0002] Currently available crosslinking ovens for mineral and / or plant fiber 10 mats comprise a heating system operated by a gas burner. It is known to add to this oven a second heating means such as an electric heating source, combined with the burner already included in the oven. In the prior art, this electric heating source is specifically arranged in the crosslinking enclosure, in particular in a corner of the crosslinking enclosure. 15

[0003] The current economic and ecological situation calls for improvements in the efficiency of the heating means used in these ovens, for example by reducing the calorific input from the burner. In this way, the electric heating source is configured to heat the mat present in the crosslinking enclosure, 20 thereby reducing the proportion of heating generated by the burner and, consequently, the gas consumption.

[0004] Nevertheless, it is necessary to go further. The space available in the crosslinking chamber does not allow the integration of sufficient electric 25 heating power to meet the power requirements for curing the mineral and / or plant fiber mat, and the amount of gas consumed by the burner remains too high. In addition, the electric heating source located in a corner of the crosslinking enclosure tends to become clogged, resulting in reduced electric heating and lower efficiency. Furthermore, this clogging requires downtime to 30 clean the electric heating source. This downtime has a negative impact on the costs of manufacturing the mineral and / or plant fiber mat. 2024357286   23 Jun 2026

[0005] In one aspect, the present invention proposes an oven for crosslinking a mat of mineral and / or plant fibers, comprising at least one combustion chamber, at least one burner configured to generate a flame within the combustion chamber and a crosslinking enclosure which is configured to 5 receive said mat and is aeraulically connected to the combustion chamber, said oven comprising at least one electric heating source configured to heat the mat, characterized in that the electric heating source is arranged inside the combustion chamber. 10

[0006] The specific arrangement of the electric heating source within the combustion chamber reduces the burner’s installed power rating. The air flow has no time to cool down and remains at a high temperature until it comes into contact with the mat circulating within the crosslinking enclosure. 15

[0007] According to another feature of some embodiments of the invention, the electric heating source is arranged so as to be exposed to the flame generated by the burner. This arrangement enables any deposits or impurities present on the electric heating source to be destroyed, for example by pyrolysis. This assembly prevents loss of efficiency due to clogging of electric heating 20 sources.

[0008] According to a further feature of some embodiments of the invention, the oven comprises a hot air loop which comprises an outlet from the combustion chamber, a passage through the crosslinking enclosure and an 25 inlet into the combustion chamber.

[0009] The air is heated in the combustion chamber via the burner and the electric heating source, and the heated air then enters the crosslinking enclosure. The hot air then transfers its calories to the mat, crosslinking the 30 glue that binds the fibers together. The air in the hot air loop leaving the crosslinking chamber is cooler than when it entered, and the burner and electric heating source add further calories to the hot air flow. 2024357286   23 Jun 2026

[0010] The glue binding the fibers is generally known as the “binder”.

[0011] According to another feature of some embodiments of the invention, the 5 oven comprises at least one air circulation device configured to circulate hot air through the hot air loop.

[0012] The air circulation device may, for example, be a fan arranged between the outlet of the combustion chamber and an inlet of the crosslinking enclosure. 10

[0013] According to a further feature of some embodiments of the invention, the electric heating source comprises at least one radiant tube resistor, said radiant tube extending transversely to a direction of hot air flow within the combustion chamber. The radiant tube extends mainly along a first direction, 15 while the air flow moves generally along a second direction, these two directions being secant at a single point. The radiant tube of the resistor extends, for example, perpendicularly to a direction of extension of the burner flame. 20

[0014] According to another feature of some embodiments of the invention, the electric heating source comprises at least two radiant tubes aligned within the combustion chamber along the same axis. The axis on which the radiant tubes are aligned is perpendicular, or substantially perpendicular, to the direction of extension of the burner flame. According to one variant, in the combustion 25 chamber, at least two radiant tubes are parallel and aligned on this axis, forming a pair of radiant tubes arranged along a common axis. The combustion chamber therefore has a minimum width enabling two radiant tubes to be placed end-to-end, along the same axis running perpendicularly through the combustion chamber. 30

[0015] A succession of several radiant tubes is operated along different axes perpendicular to the combustion chamber. 2024357286   23 Jun 2026

[0016] According to another feature of some embodiments of the invention, the electric heating source comprises at least two radiant tubes arranged within the combustion chamber along two distinct axes. 5

[0017] The axes on which the radiant tubes are aligned are perpendicular to a direction of extension of the burner flame. A single radiant tube is positioned on each axis. Multiple radiant tubes may be arranged side-by-side, along parallel but distinct axes. 10

[0018] According to another feature of some embodiments of the invention, the combustion chamber comprises a first section where the burner is arranged and a second section where the electric heating source is arranged, a volume of the first section being smaller than a volume of the second section. 15

[0019] The volume of the second section is greater than that of the first section, so that at least two radiant tubes may be arranged end-to-end, aligned on the same axis. Limiting certain sections reduces the amount of air to be heated, and therefore the power required for heating. 20

[0020] According to another feature of some embodiments of the invention, the combustion chamber comprises a first section where the burner is arranged and a second section where the electric heating source is arranged, a volume of the first section being equal to a volume of the second section. 25

[0021] In this embodiment, the radiant tubes are arranged side-by-side, along a single row. The radiant tubes are inserted into the combustion chamber from one side only, or from two sides arranged opposite each other. 30

[0022] In some embodiments, the combustion chamber is delimited by a peripheral wall which comprises at least one outer frame, an inner peripheral metal sheet and a thermal insulator arranged between said peripheral wall and 2024357286   23 Jun 2026 the inner peripheral metal sheet. According to another feature of the invention, the combustion chamber is delimited by a peripheral wall comprising at least one outer frame, an inner peripheral metal sheet and thermal insulation arranged between the two metal sheets. 5

[0023] The temperature of the outer frame of the combustion chamber must be less than 60 degrees Celsius (°C). The assembly as envisaged here reduces the nominal power of the burner. For this reason, the structure of the peripheral wall of the combustion chamber may be a sandwich of metal sheets with 10 thermal insulation between them.

[0024] According to another feature of some embodiments of the invention, the nominal power of the electric heating source is greater than or equal to the nominal power of the burner. In this way, the gas consumption can be reduced 15 compared with a prior art system with equivalent total power.

[0025] The nominal power of the burner is, for example, 200 kW, whereas the nominal power of the electric source is, for example, 220 kW. The system requires 220 kW / h at steady state. The total heat output of the oven is 50% 20 from the electric heating source and 50% from the burner. Alternatively, the distribution can be modified until 75% of the total heat production is provided by the electric heating source and 25% by the burner. It is thus possible to consider that the electric heating source provides between 50% and 90% of the heating power required by the system. 25

[0026] The invention also relates to a method for manufacturing an insulation product comprising mineral and / or plant fibers bound by a binder, in particular an organic binder, the method comprising the following steps: - providing a mat of mineral and / or plant fibers coated with a binder, in 30 particular an organic binder, and 2024357286   23 Jun 2026 - heating the mat, the heating step being carried out by the crosslinking oven as defined above, the mat being placed in the crosslinking enclosure of the crosslinking oven during heating. 5

[0027] According to another feature of some embodiments of the invention, the mass ratio of binder in the insulation product is strictly greater than 0% and less than or equal to 20%, preferably greater than or equal to 2% and less than or equal to 10%, relative to the total mass of the insulation product. 10

[0028] According to a further feature of some embodiments of the invention, the crosslinking oven comprises a hot air loop which comprises an outlet from the combustion chamber, a passage through the crosslinking enclosure and an inlet into the combustion chamber, the mat housed in the crosslinking enclosure being heated during heating by a flow of hot air circulating in the hot 15 air loop.

[0029] According to another feature of some embodiments of the invention, the hot air flow is, for example, at a temperature greater than or equal to 100°C and less than or equal to 320°C, in particular greater than or equal to 220°C 20 and less than or equal to 300°C, for example greater than or equal to 250°C and less than or equal to 300°C, for example equal to 260°C.

[0030] Other features and advantages of embodiments of the invention will appear both from the description which follows and from multiple exemplary 25 embodiments, which are given for illustrative purposes and without limitation with reference to the appended schematic drawings, in which: [Fig 1], Fig. 1 is a representation of a crosslinking oven comprising a combustion chamber which consists of a burner and an electric heating source; 30 [Fig. 2], Fig. 2 is a cross-sectional view of an embodiment of the combustion chamber of the oven according to the invention; 2024357286   23 Jun 2026 [Fig. 3], Fig. 3 is a cross-sectional view of another embodiment of the combustion chamber of the oven according to the invention; [Fig. 4], Fig. 4 is a cross-sectional view of a peripheral wall surrounding the combustion chamber. 5

[0031] The features, variants, and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. 10

[0032] In particular, it is possible to imagine variants of the invention comprising only a selection of features described hereinafter in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art. 15

[0033] The invention relates to a new oven and more particularly to a new combustion chamber of this oven which allows the crosslinking enclosure to be heated by calories from a burner and by calories from an electric heating source, these two components being arranged inside the combustion chamber. 20

[0034] Fig. 1 shows a crosslinking oven 2 according to the invention, comprising a combustion chamber 4, a crosslinking enclosure 6 and a device for circulating a hot air flow 8. 25

[0035] Fig. 1 shows that the combustion chamber 4 is located at the top of the crosslinking oven 2. More specifically, the combustion chamber 4 is located vertically above the crosslinking enclosure 6. The combustion chamber 4 is connected aeraulically to the crosslinking enclosure 6, on the one hand, by a first duct 10 arranged between an outlet 11 of the combustion chamber 4 and 30 an inlet 13 of the crosslinking enclosure 6 and, on the other hand, by a second duct 12 extending between a discharge port 15 of the crosslinking enclosure 6 and an inlet 17 of the combustion chamber 4. The combination of these ducts 2024357286   23 Jun 2026 10, 12, the combustion chamber 4 and the crosslinking enclosure 6 forms a hot-air loop in which a flow of hot air circulates in a loop.

[0036] The crosslinking oven 2 comprises a support 19 configured to support 5 the combustion chamber 4. The support 19 extends above the crosslinking enclosure 6 and supports the weight of the combustion chamber 4.

[0037] The combustion chamber 4 comprises a burner 14 configured to generate a flame within the combustion chamber 4. In general, the burner 14 10 is fueled by gas.

[0038] The combustion chamber 4 can comprise a hot air circulation device 8, such as a radial impeller fan 7 configured to implement air flow circulation within the hot air loop. The radial impeller 7 is configured to change the 15 direction of air flow within the hot air loop from a horizontal direction in the combustion chamber 4 to a vertical direction in the first duct 10. The air circulation device 8 is connected on one side to a portion of the combustion chamber 4 and on the other to the outlet 11 of the combustion chamber 4. The circulation device comprises an actuating device 9 such as a motor and 20 gearbox configured to actuate the rotation of the impeller 7 of the circulation device 8.

[0039] The crosslinking enclosure 6 receives at least one mat 16 of mineral and / or plant fibers, such a mat 16 being intended to become a roll or panel of 25 glass wool, rock wool or a plant material used to thermally insulate any duct, wall or, more generally, any object requiring thermal insulation.

[0040] The hot air flow passes through the fiber mat(s) 16. The inlet 13 of the crosslinking enclosure 6 is located at the top of a box which defines the 30 crosslinking enclosure 6. The discharge port 15 of the crosslinking enclosure 6 is located at the bottom of this box, on a side opposite that of the inlet port 2024357286   23 Jun 2026 13. The air flow thus follows a diagonal, downward path as it passes through the crosslinking enclosure 6.

[0041] Fig. 2 and 3 show that, according to the invention, the combustion 5 chamber 4 houses an electric heating source 18, such as radiant tubes, for example, inserted on either side of the combustion chamber 4.

[0042] The radiant tube is a metal cylinder comprising an inner surface and an outer surface. The outer surface of the radiant tube is in contact with the air 10 flow of the hot air loop, which is why the tube, or at least the outer surface of the tube, comprises or is coated with a material capable of resisting the corrosive nature of the burner flame. The inner surface is configured to be in contact with air heated by a resistor comprised in the radiant tube. The radiant tube is hermetically sealed, with the free end inside the combustion chamber 15   4 being closed. The radiant tube comprises a flange on the free end outside the combustion chamber 4. The radiant tube is secured to the combustion chamber 4, for example by releasably mounting the flange to the outer metal sheet of the combustion chamber 4. 20

[0043] The radiant tubes arranged in the combustion chamber 4 are spaced apart to allow the air flow to pass through the combustion chamber 4 and exchange heat with the metal cylinders heated by the resistors.

[0044] The flame of the burner 14 is in contact with the radiant tubes. Thus, a 25 direction of extension 27 illustrating a projection of the burner flame 14, is secant, advantageously perpendicular, to an axis 20 of each of the radiant tubes.

[0045] Fig. 2 shows a longitudinal sectional view of one embodiment of the 30 combustion chamber 4, the crosslinking oven 2, the burner 14 and the circulation device 8. The burner 14 is arranged at a first end of the combustion chamber 4 so that its flame extends into the combustion chamber 4 along the 2024357286   23 Jun 2026 extension direction 27. At the other end of the combustion chamber is the circulation device 8.

[0046] By way of example, thirty radiant tubes are arranged in the combustion 5 chamber 4, organized in six rows of radiant tubes arranged in two blocks of three rows facing each other, each row comprising five radiant tubes arranged one above the other. The combination of these radiant tubes forms the electric heating source 18. The tubes of a first block of radiant tubes are aligned with the tubes of a second block of tubes, along the axis 20 passing perpendicularly 10 through the combustion chamber 4. The block tubes are thus aligned in pairs, each pair sharing the same axis 20, with the air flow flowing over each pair of radiant tubes aligned end-to-end.

[0047] The combustion chamber 4 comprises a first section 22 where the 15 burner 14 is at least partly arranged, and a second section 24 where the electric heating source 18 is arranged. Fig. 2 shows that the second section 24 has dimensions greater than those of the first section 22. The volume of the first section 22 is thus smaller than the volume of the second section 24. 20

[0048] The first section 22 and the second section 24 are aligned along the extension direction 27.

[0049] The second section 24 is arranged vertically above the combustion chamber 4. The electric heating source 18 is thus located vertically above the 25 combustion chamber 4.

[0050] The combustion chamber 4 also comprises a divergent section 21 connecting the first section 22 to the second section 24, in the form of a conical tube. The combustion chamber 4 also comprises a convergent section 23 30 which connects the second section 24 to the hot air flow circulation device 8, this convergent section being in the form of a conical channel. 2024357286   23 Jun 2026

[0051] Fig. 3 is a longitudinal cross-sectional view of another embodiment of the combustion chamber 4 of the crosslinking oven 2. The burner 14 is arranged at a first end of the combustion chamber 4 so that its flame extends into the combustion chamber 4 along the extension direction 27. At the other 5 end of the combustion chamber 4 is the circulation device 8, the function of which is to circulate the hot air flow within the hot air loop.

[0052] By way of example, thirty-two radiant tubes are arranged in the combustion chamber 4, organized in eight rows of radiant tubes arranged in a 10 block, each row comprising four radiant tubes arranged one above the other. The combination of these radiant tubes forms the electric heating source 18. Each radiant tube is aligned along a separate axis 20 running perpendicularly through the combustion chamber 4. The radiant tubes are thus aligned one-by-one, side-by-side, along separate but parallel axes 20. 15

[0053] The second section 24, in which the electric heating source 18 is located, has dimensions greater than or equal to those of the first section 22, in which the burner 14 is located. 20

[0054] Fig. 4 is a cross-sectional view illustrating a new type of thermal insulation of the combustion chamber 4, which is made possible by the arrangement of the electric heating source 18 within the combustion chamber 4. 25

[0055] The insulation of the combustion chamber 4 comprises six layers, for example: the first layer 26 is a peripheral metal sheet inside the combustion chamber 4, in this case a steel or stainless steel coating. The choice of placing this metal sheet inside the combustion chamber 4 is advantageous because it prevents premature wear of the thermal insulation layer, which could result 30 from friction from the hot air flow circulating within the hot air loop, or even from the flame itself. 2024357286   23 Jun 2026

[0056] The second 28 and third 30 layers of the combustion chamber 4 are high-temperature microporous thermal insulators, each 50 mm thick, for example. 5

[0057] The fourth 32 and fifth 34 layers comprise two different insulators between the side walls 36 and the top and bottom walls 38. The side walls 36 are rock wool panels. The top and bottom walls 38 are rigid mineral fiber panels. The fourth 32 and fifth 34 layers are 50 mm thick. The sixth layer 40 is an external frame that surrounds and holds the five layers described above. 10 The first layer 26 is the inner peripheral metal sheet closest to the flame generated by the burner 14, while the sixth layer 40 is closest to the external environment of the combustion chamber 4.

[0058] The invention also relates to a method of manufacturing an insulation 15 product comprising mineral and / or plant fibers.

[0059] Such a product is, as previously mentioned, a roll or panel of glass wool, rock wool or plant material used to thermally insulate any duct, wall or more generally any object requiring thermal insulation. 20

[0060] The insulation product comprises a binder.

[0061] The binder is, for example, an organic binder. 25

[0062] In this way, the mineral and / or plant fibers of the insulation product are bound by the binder.

[0063] For example, the insulation product has a binder mass ratio strictly greater than 0% and less than or equal to 20%, in particular greater than or 30 equal to 2% and less than or equal to 10%, relative to the total mass of the insulation product. 2024357286   23 Jun 2026

[0064] The method comprises a step of providing the mat 16 of mineral and / or plant fibers with binder.

[0065] In this example, the binder is an organic binder. 5

[0066] The manufacturing method further comprises a step of heating the mat 16. The heating step is carried out with the crosslinking oven 2.

[0067] During the heating step, the mat 16 is placed in the crosslinking 10 enclosure 6 of the oven 2.

[0068] Furthermore, during heating, the mat 16 placed in the crosslinking enclosure 6 is heated by the flow of hot air circulating in the oven 2. 15

[0069] The hot air flow is generated by the hot air circulation device 8.

[0070] The hot air flow passes through the mat 16 placed in the crosslinking enclosure 6. 20

[0071] For example, the hot air flow is at a temperature greater than or equal to 100 degrees Celsius (°C) and less than or equal to 320°C, in particular greater than or equal to 220°C and less than or equal to 300°C, for example greater than or equal to 250°C and less than or equal to 300°C, for example equal to 260°C. 25

[0072] In the present example, the mat 16 is heated to a temperature and for a time that allows the binder to harden, i.e. crosslink.

[0073] Of course, the invention is not limited to the examples that have just 30 been described, and numerous modifications can be made to these examples, without departing from the scope of the invention. 2024357286   23 Jun 2026

[0074] One or more embodiments of the invention, as described above, may make it possible to offer a crosslinking oven which comprises at least two heating sources arranged inside a combustion chamber, the two heating sources being at least one source of electric energy and one source of energy 5 resulting from combustion. Variations not described here could be implemented without deviating from the context of the invention, provided that, in accordance with the invention, they comprise a combustion chamber comprising at least one resistor in accordance with the invention. 10

[0075] It is to be understood that, if any prior art publication (or information derived from it), or any matter which is known, is referred to herein, such reference does not constitute an admission that the publication (or information derived from it) or known matter forms a part of the common general knowledge in the art, in Australia or any other country. 15

[0076] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the 20 presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

5   1.     An oven for crosslinking a mat of mineral and / or plant fibers, comprisingat least one combustion chamber, at least one burner configured to generate a flame inside the combustion chamber and a crosslinking enclosure aeraulically connected to the combustion chamber and configured to receive the mat, the oven comprising at least one electric heating source for the mat, 10 characterized in that the electric heating source is arranged inside the combustion chamber.

2. The crosslinking oven according to the preceding claim, wherein theelectric heating source is arranged so as to be exposed to the flame generated 15 by the burner.

3. The crosslinking oven according to any one of the preceding claims,comprising a hot air loop which comprises an outlet from the combustion chamber, a passage through the crosslinking enclosure and an inlet into the 20 combustion chamber.

4. The crosslinking oven according to the preceding claim, comprising atleast one air circulation device configured to circulate hot air through the hot air loop.

255. The crosslinking oven according to any one of the preceding claims,wherein the electric heating source comprises at least one radiant tube resistor, said radiant tube resistor extending transversely to a direction of hot air flow within the combustion chamber.302024357286   23 Jun 20266.    The crosslinking oven according to any one of the preceding claims,wherein the electric heating source comprises at least two radiant tube resistors aligned within the combustion chamber along the same axis.5   7.    The crosslinking oven according to any one of claims 1 to 5, whereinthe electric heating source comprises at least two radiant tube resistors arranged within the combustion chamber along two separate axes.

8. The crosslinking oven according to claim 6, wherein the combustion10 chamber comprises a first section where the burner is arranged and a second section where the electric heating source is arranged, a volume of the first section being smaller than a volume of the second section.

9. The crosslinking oven according to claim 7, wherein the combustion15 chamber comprises a first section where the burner is arranged and a second section where the electric heating source is arranged, a volume of the first section being equal to a volume of the second section.

10. The crosslinking oven according to any one of the preceding claims, 20 wherein the combustion chamber is delimited by a peripheral wall which comprises at least one outer frame, an inner peripheral metal sheet and a thermal insulator arranged between said peripheral wall and the inner peripheral metal sheet.25   11. The crosslinking oven according to any one of the preceding claims,wherein a nominal power of the electric heating source is greater than or equal to a nominal power of the burner.

12. A method for manufacturing an insulation product comprising mineral 30 and / or plant fibers bonded by an organic binder, said method comprising the following steps:2024357286   23 Jun 2026- providing a mat of mineral and / or plant fibers coated with a binder, in particular an organic binder, and- heating the mat, the heating step being carried out by the crosslinking oven according to any one of claims 1 to 11, the mat being housed in the 5 crosslinking enclosure of the crosslinking oven during heating.

13. The manufacturing method according to claim 12, wherein the massratio of binder in the insulation product is strictly greater than 0% and less than or equal to 20%, relative to the total mass of the insulation product.1014. The manufacturing method according to claim 13, wherein the mass ratio of binder in the insulation product is greater than or equal to 2% and less than or equal to 10%, relative to the total mass of the insulation product.15   15.   The manufacturing method according to claim 12, 13 or 14, wherein thecrosslinking oven comprises a hot air loop which comprises an outlet from the combustion chamber, a passage through the crosslinking enclosure and an inlet into the combustion chamber, the mat housed in the crosslinking enclosure being heated during heating by a flow of hot air circulating in the hot20 air loop.

16. The manufacturing method according to claim 15, wherein the flow of hot air heating the mat is at a temperature greater than or equal to 100 degrees Celsius and less than or equal to 320 degrees Celsius.

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