Combustor and heat treatment equipment

Abstract

A combustor is provided with: a combustion cylinder that forms a combustion chamber for combusting fuel; the at least one nozzle pipe is arranged in the combustion cylinder and is used for spraying gas containing the fuel or the air to the combustion chamber; and a nozzle plate which extends inside the combustion cylinder along a plane orthogonal to the axial direction of the combustion cylinder and which has at least one hole into which the tip of each of the at least one nozzle tube is fitted, a hole-forming portion of the nozzle plate, which forms the at least one hole, contains SiC or graphite, and the nozzle plate is provided with at least one nozzle tube. The front end portion of the nozzle tube is made of an Fe-Cr-Al alloy.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a burner and a heat treatment apparatus. BACKGROUND

[0002] In heat treatment of a metal plate or the like, a burner that causes a gaseous fuel to burn is used.

[0003] In Patent Literature 1, a burner that has a nozzle pipe for ejecting a fuel to a combustion chamber formed in the inside of a combustion cylinder is described. In the burner, the nozzle pipe is provided so as to extend along the axial direction of the combustion cylinder, and is supported by a nozzle plate provided in the inside of the combustion cylinder. The nozzle plate is provided so as to extend along a plane orthogonal to the axial direction of the combustion cylinder, so as to form the combustion chamber, and the front end portion of the nozzle pipe is fitted to a hole provided in the nozzle plate.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent No. 6823730 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, depending on the operating conditions of the heat treatment apparatus or the structure of the combustion cylinder or the like, the nozzle plate sometimes becomes high temperature, and the nozzle plate and the nozzle pipe fitted to the hole of the nozzle plate adhere to each other. If the nozzle plate and the nozzle pipe adhere to each other, the heat resistance of the nozzle decreases, and it can lead to malfunction of the burner due to deformation or thinning of the wall of the nozzle, or an obstacle to maintenance.

[0009] In view of the above, an object of at least one embodiment of the present application is to provide a burner and a heat treatment apparatus that can suppress adhesion of members to each other.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The burner of at least one embodiment of the present application has: a combustion cylinder that forms a combustion chamber for causing a fuel to burn; at least one nozzle pipe that is provided in the inside of the combustion cylinder, and that is used for ejecting a gas containing the fuel or air to the combustion chamber; and a nozzle plate that extends along a plane orthogonal to the axial direction of the combustion cylinder in the inside of the combustion cylinder, and that has at least one hole into which the front end portion of the at least one nozzle pipe is fitted respectively, wherein the hole forming portion of the at least one hole in the nozzle plate contains SiC or graphite, and the front end portion of the nozzle pipe contains an Fe-Cr-Al based alloy.

[0012] Further, the heat treatment apparatus of at least one embodiment of the present application has the above-described burner, and a fuel supply line for supplying a fuel to the burner.

[0013] Invention Effects

[0014] According to at least one embodiment of the present invention, a burner and heat treatment apparatus capable of suppressing the adhesion of components to each other are provided. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of a burner according to one embodiment.

[0016] Figure 2 yes Figure 1 An enlarged view of the front part of the burner shown.

[0017] Figure 3 It is along Figure 2 A cross-sectional view along line AA.

[0018] Figure 4 This is a schematic cross-sectional view of the front portion of a burner according to one embodiment.

[0019] Figure 5 This is a schematic cross-sectional view of the front portion of a burner according to one embodiment.

[0020] Figure 6 This is a schematic cross-sectional view of the front portion of a burner according to one embodiment.

[0021] Figure 7 This is a schematic diagram showing the flow of gas in the combustion chamber of a burner.

[0022] Figure 8 This is a schematic cross-sectional view of the front portion of a burner according to one embodiment. Detailed Implementation

[0023] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. The dimensions, materials, shapes, and relative arrangements of the constituent components described or shown in the drawings as embodiments are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0024] Figure 1 This is a schematic cross-sectional view of a burner according to one embodiment. Figure 2 yes Figure 1 An enlarged view of the front portion of the burner 1 shown. Figure 3 It is along Figure 2 A cross-sectional view along line AA. Figure 4~Figure 6 and Figure 8 These are schematic cross-sectional views of the front portion of the burner 1 according to one embodiment. It should be noted that, in this specification, in the axial direction of the burner 1 (or the axial direction of the combustion cylinder 24), the side where the opening 25 of the combustion cylinder 24 is located is designated as the front, and the opposite side is designated as the rear.

[0025] like Figure 1~Figure 6 As shown, the burner 1 includes: a combustion tube 24 forming a combustion chamber 23; at least one nozzle tube 40 (41, 42), which respectively forms at least one combustion nozzle 2 (3, 4) for injecting a gas containing fuel or air into the combustion chamber 23; and a nozzle plate 30 for supporting the at least one nozzle tube 40. It should be noted that in the illustrated embodiment, the burner 1 includes multiple nozzle tubes 40 (41, 42).

[0026] Combustion tube 24 includes components along the axial direction (central axis O (reference)). Figure 2 A cylindrical member extending in the direction of the combustion chamber 24 forms a combustion chamber 23 for burning fuel. Typically, the combustion chamber 23 is formed by the inner circumferential surface of the front end of the combustion chamber 24 and the nozzle plate 30. The combustion chamber 23 is formed at the front end of the combustion chamber 24 and communicates with the opening 25 of the combustion chamber 24.

[0027] At least one nozzle pipe 40 is disposed inside the combustion cylinder 24 and configured to inject a gas containing fuel or air into the combustion chamber 23. The at least one nozzle pipe 40 may also be disposed such that it extends along the axial direction of the combustion cylinder 24.

[0028] The burner 1 includes an ignition rod 10 for igniting a fuel-containing gas. The ignition rod 10 is inserted into any one of at least one nozzle tube 40. Figure 1 As shown, the ignition rod 10 is mounted on the spark plug 9. Additionally, as... Figure 2 As shown, the ignition rod 10, except for its front end, is covered by an insulating tube 11 formed of an insulator, which insulates it from the surrounding components. When the burner 1 is ignited, a spark is generated at the front end of the ignition rod 10 to ignite the fuel-containing gas ejected from the nozzle tube 40.

[0029] exist Figure 1~Figure 6 In the exemplary embodiment shown, the ignition rod 10 is disposed inside the first nozzle 3 of the plurality of combustion nozzles 2 (3, 4). Furthermore, the second nozzle 4, other than the first nozzle 3 in the plurality of combustion nozzles 2 (3, 4), does not have the ignition rod 10 disposed therein. That is, the plurality of nozzle tubes 40 forming the plurality of combustion nozzles 2 respectively include: a first nozzle tube 41 through which the ignition rod 10 is inserted (the nozzle tube 40 forming the first nozzle 3); and a second nozzle tube 42 other than the first nozzle tube 41 (the nozzle tube 40 forming the second nozzle 4, which does not have the ignition rod 10 inserted therein).

[0030] The nozzle plate 30 is disposed inside the combustion chamber 24 in a manner extending along a plane orthogonal to the axial direction of the combustion chamber 24. For example... Figure 2As shown, the nozzle plate 30 has at least one hole 31 that can be fitted into the front ends (front ends) 41a, 42a of the nozzle tubes 40 (41, 42). The hole 31 is provided in such a way that it extends through the nozzle plate 30 in the axial direction.

[0031] like Figure 2 and Figure 4~Figure 6 As shown, the front ends (front ends) 41a and 42a of each of the nozzle tubes 40 (41, 42) are fitted into the holes 31 of the nozzle plate 30. Furthermore, the rear ends (ends opposite to the front ends 41a and 42a) of each of the nozzle tubes 40 (41, 42) are fitted into the holes 17 formed in the front plate 14 located further rearward than the nozzle plate 30. Thus, the nozzle tubes 40 (41, 42) are supported to extend axially along the combustion chamber 24.

[0032] It should be noted that heat-resistant material 36 can also be provided around the nozzle tube 40 between the nozzle plate 30 and the front plate 14.

[0033] For example, Figure 3 As shown, multiple combustion nozzles 2 (3, 4) can also be arranged circumferentially around the central axis O of the combustion cylinder 24. Alternatively, the multiple combustion nozzles 2 (3, 4) can be positioned at different radial locations. Figure 3 In the example shown, the plurality of combustion nozzles 2 include a first nozzle 3 disposed at the center in the radial direction, six second nozzles 4 arranged in a circular pattern on the inner circumference side, and ten second nozzles 4 arranged in a circular pattern on the outer circumference side.

[0034] It should be noted that in several embodiments, the first nozzle 3 may not be located at the radial center. For example, a plurality of combustion nozzles 2 arranged in a circular pattern may include a first nozzle 3 and a plurality of second nozzles 4.

[0035] A first gas containing fuel is supplied to the first nozzle 3 via the first gas passage 6. A second gas containing fuel or air is supplied to the second nozzle 4 via the second gas passage 8. The first gas and the second gas supplied to the first nozzle 3 and the second nozzle 4 may also be fuel gas, air, or a premixed gas formed by premixing fuel and air.

[0036] In the burner 1, a flame is generated by burning fuel-containing gas ejected from the outlets 3a and 4a of the first nozzle 3 and the second nozzle 4. This flame is ejected from the opening 25 formed at the front end of the combustion cylinder 24. In this way, the workpiece 101 is heat-treated by the flame F ejected from the combustion cylinder 24.

[0037] The first gas passage 6 described above may also include a flow path 13 formed by a pipe 12 disposed behind the first nozzle 3, a first chamber 26 formed inside the first cylindrical member 20, and a first inlet flow path 54 formed by a first inlet pipe 52 connected to the first cylindrical member 20.

[0038] The tube 12 is provided such that it extends at least between the front plate 14 and the rear plate 16 disposed behind the front plate 14. Furthermore, the ignition rod 10 disposed inside the first nozzle 3 is inserted through the tube 12. In the illustrated embodiment, the tube 12 is provided such that it passes through the rear plate 16. Additionally, as... Figure 2 As shown, an external thread 44 can also be formed at the front end 12a of the tube 12, and the tube 12 can be fastened to the front plate 14 by screwing the end 12a into the threaded hole 45 formed in the front plate 14.

[0039] Alternatively, the tube 12 can be connected to the front plate 14 by fitting the front end 12a of the tube 12 into a hole formed in the front plate 14. Furthermore, an oil seal or similar material can be provided at the fitting portion.

[0040] Or, such as Figure 8 As shown, the tube 12 and the first nozzle tube 41 can also be integrally formed, with the integral tube 12 and the first nozzle tube 41 fitting into the hole 17 formed in the front plate 14, thereby connecting the tube 12 and the first nozzle tube 41 to the front plate 14. This allows the ignition rod 10 and the first nozzle tube 41 to be integrally pulled out of the combustion chamber 24, making it easy to check the spark status outside the furnace. Furthermore, when the ignition rod 10 is inserted into the tube 12 and the first nozzle tube 41, the insulator at the front end of the ignition rod 10 (insulating tube 11, a component for centering the ignition rod not shown) will not get stuck on the step at the connection between the first nozzle tube 41, the front plate 14, and the tube 12. Figure 8 As shown, a sealing part 18 (e.g., an oil seal) may also be provided radially between the pipe 12 and the first nozzle pipe 41 and the front plate 14 to reduce gas leakage through the gap between the pipe 12 and the first nozzle pipe 41 and the front plate 14.

[0041] The first cylindrical member 20 is disposed behind the rear plate 16 in an axially extending manner. The front end of the first cylindrical member 20 may also be mounted to the rear plate 16. Alternatively, the front end of the first cylindrical member 20 may be mounted to the rear plate 16 by fitting a tube 12 into the front end of the first cylindrical member 20 and fitting the tube 12 into the rear plate 16. The opening at the rear end of the first cylindrical member 20 may also be closed by inserting a spark plug 9.

[0042] The aforementioned second gas passage 8 may also include a second chamber 28 and a second inlet flow path 58. For example... Figure 1As shown, the second chamber 28 can also be formed by the inner wall surface of the front plate 14, the rear plate 16, and the second cylindrical member 22 extending axially between the front plate 14 and the rear plate 16. The second inlet flow path 58 can also be formed by the second inlet pipe 56 connected to the second cylindrical member 22.

[0043] It should be noted that, Figure 1 The burner 1 shown is mounted on the furnace wall 38. The furnace wall 38 may also be formed at least partially by heat insulation.

[0044] In several embodiments, the hole-forming portion of the nozzle plate 30, which forms the hole 31 for fitting the nozzle tube 40, is made of SiC (silicon carbide) or graphite (carbon graphite), and the front ends 41a and 42a of the nozzle tubes 40 (41, 42) are made of Fe-Cr-Al alloy. Here, the hole-forming portion of the nozzle plate 30 is the portion including the inner wall surface of the hole 31. Furthermore, the front ends 41a and 42a of the nozzle tubes 40 (41, 42) are the portions of the nozzle tubes 40 that fit into the hole 31 of the nozzle plate 30, and are located axially in the extension region of the nozzle plate 30.

[0045] That is, in several embodiments, the above-mentioned hole forming portion of the nozzle plate 30 is formed of SiC (silicon carbide) or graphite, and the front ends 41a, 42a of the nozzle tubes 40 (41, 42) are formed of Fe-Cr-Al alloy.

[0046] It should be noted that, in several embodiments, the entire orifice forming portion of the nozzle plate 30 may also be formed of SiC (silicon carbide) or graphite. Alternatively, in several embodiments, the entire nozzle tube 40 (41, 42) may also be formed of an Fe-Cr-Al alloy.

[0047] The SiC forming the hole forming portion of the nozzle plate 30 may contain atmospheric pressure sintered material or reaction sintered material.

[0048] The Fe-Cr-Al alloy forming the front ends 41a and 42a of the nozzle tubes 40 (41, 42) is an alloy containing 61% to 83% by weight of iron (Fe), 15% to 25% by weight of chromium (Cr), and 2% to 8% by weight of aluminum (Al). This Fe-Cr-Al alloy may further contain 3% to 1% by weight of molybdenum (Mo), 1% to 1% by weight of manganese (Mn), 1% to 1% by weight of silicon (Si), and / or 1% to 1% by weight of carbon (C).

[0049] In the past, when the nozzle plate reached high temperatures due to the operating conditions of the heat treatment equipment or the structure of the combustion chamber, the nozzle plate sometimes adhered to the nozzle tube fitted into the hole of the nozzle plate. For example, in the case of a nozzle plate made of SiC and a nozzle tube made of high-Cr-Ni steel, under high-temperature conditions, the reaction between SiC and the chromium (Cr) contained in the high-Cr-Ni steel easily forms Cr3C2, causing the nozzle plate and nozzle tube to adhere. If the nozzle plate and nozzle tube adhere in this way, the heat resistance of the nozzle decreases, which may lead to burner failure due to nozzle deformation and thinning of the wall thickness, and may also create obstacles to maintenance.

[0050] In this regard, in the above embodiment, the orifice forming portion of the nozzle plate 30 is formed of SiC (silicon carbide) or graphite, and the front ends 41a and 42a of the nozzle tubes 40 (41, 42) are formed of Fe-Cr-Al alloy. Therefore, when the nozzle plate 30 reaches a high temperature, an aluminum oxide (Al2O3) film is formed on the surface of the front ends 41a and 42a of the nozzle tubes 40 (41, 42). This film prevents the Cr at the nozzle tip from reacting with the C contained in SiC and graphite, thus suppressing adhesion between the nozzle plate and the nozzle tube even when the nozzle plate reaches a high temperature.

[0051] In several implementations, for example, Figure 4~Figure 6 As shown, the combustion chamber 24 may also have a segmented structure comprising multiple interconnected components.

[0052] exist Figure 4~Figure 6 In the exemplary embodiment shown, the combustion chamber 24 includes a base end member 60 surrounding at least one nozzle tube 40 and a front end member 62 having an opening 25 of the combustion chamber 24. The base end member 60 and the front end member 62 are connected to each other axially at a position further forward than the nozzle plate 30 (i.e., a forward position). It should be noted that the front end member 62 is located further forward than the nozzle plate 30.

[0053] exist Figure 4~Figure 6 In the exemplary embodiment shown, the base member 60 has an inward flange 61 at its front end, and the front member 62 has an outward flange 63 at its rear end. Furthermore, the base member 60 and the front member 62 are connected by the contact between the surface 61a of the inward flange 61 and the surface 63a of the outward flange 63.

[0054] In the case where the combustion chamber 24 has a segmented structure including a base member 60 and a front member 62, the temperature gradient between the components can be reduced, thus suppressing the generation of cracks caused by thermal stress. However, the heat from the higher-temperature front member 62 is difficult to transfer to the base member 60, so the temperature of the front member 62 and the combustion chamber 23 easily becomes high, and the nozzle plate 30 also easily becomes even higher. Regarding this point, in the above embodiment, although the combustion chamber 24 includes a structure with a base member 60 and a front member 62 and the nozzle plate 30 easily becomes high-temperature, as described above, even if the nozzle plate 30 becomes high-temperature, adhesion between the nozzle plate 30 and the nozzle tube 40 can be suppressed.

[0055] In several implementations, for example, Figure 2 , Figure 4 as well as Figure 5 As shown, the burner 1 has a heat insulation member 46 disposed between the combustion cylinder 24 and the nozzle plate 30.

[0056] exist Figure 2 In the exemplary embodiment shown, a heat insulation member 46 is provided between the inner peripheral surface 24a of the combustion cylinder 24 and the outer peripheral surface 30a of the nozzle plate 30. Figure 4 In the exemplary embodiment shown, a heat insulation member 46 is provided between the rear end face 62a of the front end member 62 constituting the combustion cylinder 24 and the front end face 30b of the nozzle plate 30. Figure 5 In the exemplary embodiment shown, heat insulation members 46 are respectively provided between the inner peripheral surface 60a of the base end member 60 constituting the combustion cylinder 24 and the outer peripheral surface 30a of the nozzle plate 30, and between the rear end surface 62a of the front end member 62 and the front end surface 30b of the nozzle plate 30.

[0057] According to the above embodiment, since a heat insulation member 46 is provided between the combustion chamber 24 and the nozzle plate 30, heat from the combustion chamber 24 is difficult to transfer to the nozzle plate 30. Therefore, even if the combustion chamber 24 becomes hot, the nozzle plate 30 can be prevented from becoming hot. Thus, adhesion between the nozzle plate 30 and the nozzle tube 40 can be more effectively suppressed.

[0058] like Figure 1 , Figure 2 and Figure 4~Figure 6 As shown, the combustion chamber 24 may also include a tapered portion 34 whose diameter gradually decreases in the axial direction as it moves from the nozzle plate 30 toward the opening 25 of the combustion chamber 24.

[0059] exist Figure 4 and Figure 5 In the exemplary embodiment shown, the conical portion 34 includes a portion of the front end member 62 that constitutes the combustion chamber 24.

[0060] exist Figure 6In the exemplary embodiment shown, the conical portion 34 includes a first conical portion 34a, which is part of the front end member 62 constituting the combustion chamber 24, and a second conical portion 34b, which is part of the base end member 60. The first conical portion 34a and the second conical portion 34b each have a shape in which the diameter gradually decreases axially as it moves from the nozzle plate 30 toward the opening 25 of the combustion chamber 24. In this case, the axial distance between the nozzle plate 30 and the opening 25 of the combustion chamber 24 is defined as L1 (refer to...). Figure 6 In this case, the second conical portion 34b may also be located within a range where the axial distance from the nozzle plate 30 is less than L1 / 2. Alternatively, the axial distance L2 between the connecting portion 64 of the front end member 62 and the base end member 60 and the nozzle plate 30 (refer to...) Figure 6 It can also be less than 1 / 2 of the distance L1 mentioned above.

[0061] In several embodiments, the radial distance R2 between the respective center of at least one hole 31 of the nozzle plate 30 and the central axis O of the combustion chamber 24 (refer to...) Figure 2~Figure 6 The inner diameter R1 of the conical portion 34 of the combustion chamber 24 is smaller than that of the combustion chamber 24 (refer to...). Figure 2~Figure 6 80% of the maximum inner diameter R1 of the tapered portion 34. Alternatively, in several embodiments, at least one hole 31 of the nozzle plate 30 may be provided in a region where the radial distance from the central axis O is less than 80% of the maximum inner diameter R1 of the tapered portion 34.

[0062] Here, Figure 7 This is a schematic diagram showing the flow of gas in the combustion chamber 23. According to the embodiment described above, the holes 31 of the nozzle plate 30 are located at a position relatively close to the radial inward side, therefore... Figure 7 As shown, in the region radially outer of the orifice 31 within the combustion chamber 23, a vortex F3 is formed by the pre-combustion fuel gas ejected from the nozzle tube 40 fitted with the orifice 31 and the combustion gas within the combustion chamber. This vortex F3 is maintained at a relatively low temperature by contacting the nozzle plate 30, whose temperature is lower than that of the flame formed in the combustion chamber 23. A portion of this relatively low-temperature vortex F3 is dragged along the inner wall of the conical portion 34 by the mainstream gas F1 ejected from the nozzle tube 40, thereby forming a relatively low-temperature gas film F2. Through this gas film F2, the movement of heat from the high-temperature gas inside the combustion chamber 23 to the combustion tube 24 can be suppressed. Therefore, it is possible to more effectively suppress the nozzle plate 30 from becoming high-temperature, thereby more effectively suppressing the adhesion between the nozzle plate 30 and the nozzle tube 40.

[0063] In several implementations, for example, Figure 1~Figure 6 As shown, the hole 31 of the nozzle plate 30 for the second nozzle tube 42 is located on the outer side of the combustion cylinder 24 in the radial direction, which is closer to the hole 31 of the nozzle plate 30 for the first nozzle tube 41.

[0064] According to the above embodiment, the hole 31 of the nozzle plate 30 for fitting the first nozzle tube 41 through which the ignition rod 10 is inserted is located radially inward than the hole 31 of the nozzle plate 30 for fitting the second nozzle tube 42 through which the ignition rod 10 is not inserted. That is, the ignition rod 10 is positioned near the central axis O of the combustion chamber 24, thus enabling stable flame maintenance. Furthermore, as described above, the ignition rod 10 is positioned near the central axis O of the combustion chamber 24, thus circumferential temperature distribution is more easily made uniform. Therefore, the generation of cracks in the combustion chamber 24 and the nozzle plate 30 can be more effectively suppressed.

[0065] In several implementations, for example, Figure 2 As shown, the front end 10a of the ignition rod 10 inserted into the first nozzle tube 41 protrudes towards the opening 25 of the combustion tube 24 from the nozzle plate 30.

[0066] In this way, the front end 10a of the ignition rod 10 protrudes further toward the opening 25 of the combustion chamber 24 than the nozzle plate 30, so that the flame formed in the combustion chamber 23 can be properly detected by the front end of the ignition rod 10.

[0067] It should be noted that by exposing the front end of the ignition rod 10 in the combustion chamber 23, the front end of the ignition rod 10 can function as the detection part of the flame rod (flame detector) and can detect whether there is a flame in the combustion chamber 23.

[0068] In the embodiment described above, where the front end 10a of the ignition rod 10 protrudes further toward the opening 25 of the combustion chamber 24 than the nozzle plate 30, the axial distance L3 between the front end 10a of the ignition rod 10 and the nozzle plate 30 (refer to...) Figure 2 It can also be 3mm or more and 20mm or less.

[0069] If the axial distance L3 between the tip 10a of the ignition rod 10 and the nozzle plate 30 is 3 mm or more, the flame formed in the combustion chamber 23 can be appropriately detected using the tip of the ignition rod 10. Furthermore, if the axial distance between the tip 10a of the ignition rod 10 and the nozzle plate 30 is 20 mm or less, the ignition rod 10 will not be exposed to excessively high temperatures. Therefore, according to the above embodiment, the flame can be appropriately detected while protecting the ignition rod 10.

[0070] The burner 1 described above can be applied to various heat treatment equipment. Several embodiments of the heat treatment equipment include the burner 1 described above and a fuel line (not shown) for supplying fuel to the burner 1.

[0071] One embodiment of the heat treatment apparatus may be a heat treatment apparatus for heat treating metal plates, such as a continuous annealing apparatus for metal plates (e.g., steel plates) or a continuous plating apparatus for metal plates (e.g., steel plates), or a heating furnace included in these apparatuses.

[0072] In several embodiments, the heat treatment apparatus for the metal sheet also includes a conveying device (not shown) for conveying the metal sheet 101, which is being treated, and a burner 1 is configured to heat the metal sheet conveyed by the conveying device. The metal sheet may also be a strip of metal. In this case, a roller, which serves as the conveying device, may be used to continuously convey the metal strip. The burner 1 may also continuously heat the metal strip conveyed by the roller.

[0073] The contents described in the above embodiments are as follows, for example.

[0074] [1] A burner (1) according to at least one embodiment of the present invention comprises: a combustion tube (24) which forms a combustion chamber (23) for burning fuel; at least one nozzle tube (40) disposed inside the combustion tube and for injecting a gas containing the fuel or air into the combustion chamber; and a nozzle plate (30) which extends inside the combustion tube along a plane orthogonal to the axial direction of the combustion tube and has at least one hole (31) for the front end of the at least one nozzle tube to be fitted, wherein the hole forming portion of the nozzle plate forming the at least one hole comprises SiC or graphite, and the front end of the nozzle tube comprises an Fe-Cr-Al alloy.

[0075] According to the structure described above [1], the orifice forming portion of the nozzle plate is formed of SiC (silicon carbide) or graphite, and the front end of the nozzle tube is formed of an Fe-Cr-Al alloy. Therefore, when the nozzle plate reaches a high temperature, an aluminum oxide (Al2O3) film is formed on the surface of the front end of the nozzle tube. This film prevents the Cr at the nozzle tip from reacting with the C contained in SiC and graphite, thus suppressing the adhesion between the nozzle plate and the nozzle tube even when the nozzle plate reaches a high temperature.

[0076] [2] In several embodiments, based on the structure of [1] above, the combustion tube includes: a base end member (60) surrounding the at least one nozzle tube; and a front end member (62) having an opening (25) of the combustion tube, wherein the base end member and the front end member are connected to each other in the axial direction of the combustion tube at a position closer to the front end than the nozzle plate.

[0077] When the combustion chamber has a segmented structure including a base end member and a front end member, the temperature gradient of each member can be reduced, thus suppressing the generation of cracks caused by thermal stress. However, the heat from the higher-temperature front end member is difficult to move to the base end member, so the temperature of the front end member and the combustion chamber easily becomes high, and the nozzle plate also easily becomes even higher. Regarding this point, according to the structure described above [2], although the combustion chamber includes a base end member and a front end member and the nozzle plate easily becomes high-temperature, as described above [1], even if the nozzle plate becomes high-temperature, the adhesion between the nozzle plate and the nozzle tube can be suppressed.

[0078] [3] In several embodiments, based on the structure of [1] or [2] above, the at least one nozzle tube includes: a first nozzle tube (41) through which the ignition rod (10) is inserted; and a second nozzle tube (42) other than the first nozzle tube, wherein the hole of the nozzle plate into which the second nozzle tube is fitted is located radially outward of the combustion chamber than the hole of the nozzle plate into which the first nozzle tube is fitted.

[0079] According to the structure described above [3], the hole in the nozzle plate for fitting the first nozzle tube into which the ignition rod is inserted is located radially inward compared to the hole in the nozzle plate for fitting the second nozzle tube into which the ignition rod is not inserted. That is, the ignition rod is positioned near the central axis of the combustion chamber, thus enabling stable flame maintenance. Furthermore, as mentioned above, the ignition rod's positioning near the central axis of the combustion chamber facilitates a more uniform circumferential temperature distribution. Therefore, the generation of cracks in the combustion chamber and nozzle plate can be more effectively suppressed.

[0080] [4] In several embodiments, based on the structure of any one of [1] to [3] above, the burner includes a heat insulation member (46) disposed between the combustion cylinder and the nozzle plate.

[0081] According to the structure described above [4], since a heat insulation component is provided between the combustion chamber and the nozzle plate, heat from the combustion chamber is difficult to move to the nozzle plate. Therefore, even if the combustion chamber becomes hot, the nozzle plate can be prevented from becoming hot. Thus, adhesion between the nozzle plate and the nozzle tube can be more effectively suppressed.

[0082] [5] In several embodiments, based on any of the structures described in [1] to [4] above, the combustion chamber includes a tapered portion (38) whose diameter gradually decreases in the axial direction of the combustion chamber as it moves from the nozzle plate toward the opening of the combustion chamber, wherein the radial distance R2 between the center of the at least one hole of the nozzle plate and the central axis of the combustion chamber is less than 80% of the maximum inner diameter R1 of the tapered portion.

[0083] According to the structure described above [5], since the orifice of the nozzle plate is located relatively radially inward, a vortex is formed in the region of the combustion chamber that is radially outward than the orifice, consisting of the pre-combustion fuel gas ejected from the nozzle tube fitted with the orifice and the combustion gas in the combustion chamber. This vortex is maintained at a relatively low temperature by contacting the nozzle plate, whose temperature is lower than that of the flame formed in the combustion chamber. A portion of this relatively low-temperature vortex is dragged along the inner wall of the conical section by the mainstream of the gas ejected from the nozzle tube, thereby forming a relatively low-temperature gas film. Through this gas film, the movement of heat from the high-temperature gas in the combustion chamber to the combustion tube can be suppressed. Therefore, it is possible to more effectively suppress the nozzle plate from becoming high-temperature, thereby more effectively suppressing the adhesion between the nozzle plate and the nozzle tube.

[0084] [6] In several embodiments, based on any of the structures described in [1] to [5] above, the at least one nozzle tube includes a first nozzle tube (41) through which an ignition rod is inserted, the front end (10a) of which protrudes further toward the opening of the combustion chamber than the nozzle plate.

[0085] According to the structure described above [6], the front end of the ignition rod protrudes towards the opening of the combustion chamber than the nozzle plate, thus enabling proper detection of the flame formed in the combustion chamber using the front end of the ignition rod.

[0086] [7] In several embodiments, based on the structure described in [8] above, the distance (L3) between the front end of the ignition rod and the nozzle plate in the axial direction is more than 3 mm and less than 20 mm.

[0087] In the structure described above [7], the axial distance between the tip of the ignition rod and the nozzle plate is 3 mm or more, thus allowing for proper detection of the flame formed in the combustion chamber using the tip of the ignition rod. Furthermore, in the structure described above [7], the axial distance between the tip of the ignition rod and the nozzle plate is 20 mm or less, preventing the ignition rod from being exposed to excessively high temperatures. Therefore, according to the structure described above [7], the flame can be properly detected while protecting the ignition rod.

[0088] [8] In several embodiments, based on the structure of [2] above, the combustion chamber includes a tapered portion (34) whose diameter gradually decreases in the axial direction of the combustion chamber as it moves from the nozzle plate toward the opening of the combustion chamber. The tapered portion includes a first tapered portion (34a) formed by the front end member and a second tapered portion (34b) formed by the base end member.

[0089] According to the structure described above [8], even in the case where the burner has a structure in which a portion of the base member (the second conical portion) forms a conical portion and the connection position between the base member and the front member is located on the front side, as described above [1], even if the nozzle plate becomes hot, the adhesion between the nozzle plate and the nozzle tube can be suppressed.

[0090] [9] In several embodiments, based on the structure of [8] above, when the axial distance between the nozzle plate and the opening of the combustion cylinder is set to L1, the second conical portion is located in the range where the axial distance from the nozzle plate is less than L1 / 2.

[0091] According to the structure described above [9], even in the case where the burner has a structure in which a portion of the base member (the second conical portion) forms a conical portion and the connection position between the base member and the front member is located on the front side, as described above [1], even if the nozzle plate becomes hot, the adhesion between the nozzle plate and the nozzle tube can be suppressed.

[0092]

[10] A heat treatment apparatus according to at least one embodiment of the present invention comprises: a burner (1) as described in any one of [1] to [9] above; and a fuel supply line for supplying fuel to the burner.

[0093] According to the structure described above

[10] , the orifice forming portion of the nozzle plate is formed of SiC (silicon carbide) or graphite, and the front end of the nozzle tube is formed of an Fe-Cr-Al alloy. Therefore, when the nozzle plate reaches a high temperature, an aluminum oxide (Al2O3) film is formed on the surface of the front end of the nozzle tube. Thus, even when the nozzle plate reaches a high temperature, adhesion between the nozzle plate and the nozzle tube can be suppressed.

[0094] The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments described above, and also includes modifications to the embodiments described above, and embodiments obtained by appropriately combining these embodiments.

[0095] In this specification, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations not only strictly indicate such configurations, but also indicate a state of relative displacement by an angle or distance with tolerance or to the extent that the same function can be obtained.

[0096] For example, terms like "same," "equal," and "homogeneous" indicate that things are equal, not only that they are strictly equal, but also that there is a difference in degree, such as the presence of a tolerance or the ability to achieve the same function.

[0097] Furthermore, in this specification, the terms "quadrilateral shape," "cylindrical shape," etc., not only refer to quadrilateral shapes, cylindrical shapes, etc., in a strictly geometric sense, but also to shapes including concave and convex parts, chamfered parts, etc., within the range where the same effect can be obtained.

[0098] Furthermore, in this specification, expressions such as "possessing," "comprises," or "have" a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

[0099] Explanation of reference numerals in the attached figures

[0100] 1. Burner

[0101] 2. Combustion Nozzle

[0102] 3 First Nozzle

[0103] 3a Export

[0104] 4 Second nozzle

[0105] 4a Export

[0106] 6 First Gas Passage

[0107] 8 Second Gas Passage

[0108] 9. Spark plugs

[0109] 10 Ignition Rods

[0110] 10a Frontend

[0111] 11 Insulating tubes

[0112] 12 tubes

[0113] 12a end

[0114] 13 flow path

[0115] 14 front panel

[0116] 16 Rear Panel

[0117] 17 holes

[0118] 18 Sealing section

[0119] 20 First tube component

[0120] 22 Second cylindrical component

[0121] 23 Combustion Chamber

[0122] 24 Combustion Tube

[0123] 24a Inner circumferential surface

[0124] 25 Opening

[0125] 26 First Chamber

[0126] 28 Second Chamber

[0127] 30 Nozzle Plate

[0128] 30a outer peripheral surface

[0129] 30b front face

[0130] 31 holes

[0131] 34. Conical part

[0132] 34a First conical part

[0133] 34b Second conical part

[0134] 36 Heat-resistant materials

[0135] 38 Furnace wall

[0136] 40 Nozzle tube

[0137] 41 First Nozzle Tube

[0138] 41a Front end

[0139] 42 Second Nozzle Tube

[0140] 42a Front end

[0141] 44 External thread

[0142] 45 threaded hole

[0143] 46 Thermal insulation components

[0144] 52 First Inlet Pipe

[0145] 54 First entrance flow path

[0146] 56 Second Inlet Pipe

[0147] 58 Second Inlet Flow Path

[0148] 60 Base end components

[0149] 60a inner surface

[0150] 61 Inward flange

[0151] 61a surface

[0152] 62 Front-end components

[0153] 62a rear end face

[0154] 63 Outward flange

[0155] 63a surface

[0156] 64 Connecting parts

[0157] 101 Items to be processed

[0158] F Flame

[0159] F1 mainstream

[0160] F2 gas membrane

[0161] F3 Vortex

[0162] L1 distance

[0163] L2 distance

[0164] L3 distance

[0165] O Central axis

[0166] R1 maximum inner diameter

[0167] R2 distance.

Claims

1. A burner, wherein, The burner includes: A combustion chamber, which is formed to burn fuel; At least one nozzle tube, disposed inside the combustion chamber, is used to inject a gas containing the fuel or air into the combustion chamber; and A nozzle plate extends inside the combustion chamber along a plane orthogonal to the axial direction of the combustion chamber and has at least one hole for the front ends of the at least one nozzle tube to be fitted into. The hole-forming portion of the nozzle plate forming the at least one hole comprises SiC or graphite, and the front end of the nozzle tube comprises an Fe-Cr-Al alloy.

2. The burner according to claim 1, wherein, The combustion chamber includes: The base end member surrounds the at least one nozzle tube; and The front-end component has an opening in the combustion chamber. The base end member and the front end member are connected to each other in the axial direction of the combustion cylinder at a position closer to the front end than the nozzle plate.

3. The burner according to claim 1 or 2, wherein, The at least one nozzle tube includes: The first nozzle tube through which the ignition rod is inserted; and A second nozzle tube other than the first nozzle tube. The hole in the nozzle plate that is fitted with the second nozzle tube is located radially outward from the hole in the nozzle plate that is fitted with the first nozzle tube.

4. The burner according to claim 1 or 2, wherein, The burner includes a heat insulation component disposed between the combustion cylinder and the nozzle plate.

5. The burner according to claim 1 or 2, wherein, The combustion chamber includes a tapered portion whose diameter gradually decreases along the axial direction of the combustion chamber as it moves from the nozzle plate toward the opening of the combustion chamber. The radial distance R2 between the center of each of the at least one hole of the nozzle plate and the central axis of the combustion cylinder is less than 80% of the maximum inner diameter R1 of the tapered portion.

6. The burner according to claim 1 or 2, wherein, The at least one nozzle tube includes a first nozzle tube through which the ignition rod is inserted. The front end of the ignition rod protrudes further toward the opening of the combustion chamber than the nozzle plate.

7. The burner according to claim 6, wherein, The distance between the front end of the ignition rod and the nozzle plate in the axial direction is more than 3 mm and less than 20 mm.

8. The burner according to claim 2, wherein, The combustion chamber includes a tapered portion whose diameter gradually decreases along the axial direction of the combustion chamber as it moves from the nozzle plate toward the opening of the combustion chamber. The tapered portion includes: The first tapered portion formed by the front end member; and The second tapered portion formed by the base end member.

9. The burner according to claim 8, wherein, When the axial distance between the nozzle plate and the opening of the combustion cylinder is set to L1, the second conical portion is located within a range where the axial distance from the nozzle plate is less than L1 / 2.

10. A heat treatment apparatus, wherein, The heat treatment equipment includes: The burner according to claim 1 or 2; and A fuel supply line for supplying fuel to the burner.

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