Burner and heat treatment facility

Abstract

This burner comprises: a combustion cylinder that forms a combustion chamber for combusting fuel; at least one nozzle pipe that is provided inside the combustion cylinder and that jets a gas containing air or the fuel into the combustion chamber; and a nozzle plate that extends, within the combustion cylinder, along a plane orthogonal to the axial direction of the combustion cylinder and that has at least one hole into which the tip of the at least one nozzle pipe is fitted. A hole formation part of the nozzle plate where the at least one hole is formed contains SiC or graphite, and the tip of the nozzle pipe contains an Fe-Cr-Al-based alloy.

Description

Burners and heat treatment equipment

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

[0002] 2. Description of the Related Art In heat treatment of metal plates and the like, a burner that burns gas fuel is used.

[0003] Patent Document 1 describes a burner equipped with a nozzle tube for injecting fuel into a combustion chamber formed inside a combustion tube. In this burner, the nozzle tube is provided to extend along the axial direction of the combustion tube and is supported by a nozzle plate provided inside the combustion tube. The nozzle plate is provided to extend along a plane perpendicular to the axial direction of the combustion tube so as to form the combustion chamber, and the tip of the nozzle tube is fitted into a hole provided in the nozzle plate.

[0004] Patent No. 6823730

[0005] However, depending on the operating conditions of the heat treatment equipment or the structure of the combustion tube, the nozzle plate may become so hot that the nozzle plate and the nozzle tube fitted into the hole in the nozzle plate may adhere to each other. If the nozzle plate and the nozzle tube adhere to each other, the heat resistance of the nozzle may decrease, which may lead to burner failure due to deformation or thinning of the nozzle, or may cause problems with maintenance.

[0006] In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a burner and heat treatment equipment that can suppress adhesion between components.

[0007] A burner according to at least one embodiment of the present invention comprises: a combustion liner forming a combustion chamber for burning fuel; at least one nozzle tube provided inside the combustion liner for ejecting gas containing the fuel or air into the combustion chamber; and a nozzle plate extending inside the combustion liner along a plane perpendicular to the axial direction of the combustion liner and having at least one hole into which a tip end of the at least one nozzle tube is fitted, wherein a hole forming portion of the nozzle plate in which the at least one hole is formed comprises SiC or graphite, and the tip end of the nozzle tube comprises an Fe-Cr-Al alloy.

[0008] Moreover, a heat treatment facility according to at least one embodiment of the present invention includes: the burner described above; and a fuel supply line for supplying fuel to the burner.

[0009] According to at least one embodiment of the present invention, there are provided a burner and heat treatment equipment capable of suppressing adhesion between members.

[0010] FIG. 1 is a schematic cross-sectional view of a burner according to an embodiment. FIG. 2 is an enlarged view of a front portion of the burner shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a schematic cross-sectional view of a front portion of a burner according to an embodiment. FIG. 5 is a schematic cross-sectional view of a front portion of a burner according to an embodiment. FIG. 6 is a schematic cross-sectional view of a front portion of a burner according to an embodiment. FIG. 7 is a schematic view showing the flow of gas in a combustion chamber of the burner. FIG. 8 is a schematic cross-sectional view of a front portion of a burner according to an embodiment.

[0011] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0012] Fig. 1 is a schematic cross-sectional view of a burner according to one embodiment. Fig. 2 is an enlarged view of the front portion of the burner 1 shown in Fig. 1, and Fig. 3 is a cross-sectional view taken along line A-A in Fig. 2. Figs. 4 to 6 and 8 are each a schematic cross-sectional view of the front portion of the burner 1 according to one embodiment. In this specification, the side where the opening 25 of the combustion liner 24 is located in the axial direction of the burner 1 (or the axial direction of the combustion liner 24) is referred to as the front, and the opposite side is referred to as the rear.

[0013] 1 to 6, the burner 1 comprises a combustion liner 24 that forms a combustion chamber 23, at least one nozzle pipe 40 (41, 42) that forms at least one combustion nozzle 2 (3, 4) for ejecting gas containing fuel or air into the combustion chamber 23, and a nozzle plate 30 that supports the at least one nozzle pipe 40. In the illustrated embodiment, the burner 1 comprises a plurality of nozzle pipes 40 (41, 42).

[0014] The combustion liner 24 includes a cylindrical member extending along the axial direction (the direction of the central axis O (see FIG. 2 )) and forms a combustion chamber 23 for burning fuel. Typically, the combustion chamber 23 is formed by an inner circumferential surface at the front end of the combustion liner 24 and a nozzle plate 30. The combustion chamber 23 is formed at the front end of the combustion liner 24 and communicates with an opening 25 of the combustion liner 24.

[0015] Each of the at least one nozzle pipe 40 is provided inside the combustion liner 24 and configured to inject gas containing fuel or air into the combustion chamber 23. Each of the at least one nozzle pipe 40 may be provided to extend along the axial direction of the combustion liner 24.

[0016] The burner 1 includes an ignition rod 10 for igniting fuel-containing gas. The ignition rod 10 is inserted into at least one of the nozzle pipes 40. As shown in FIG. 1, the ignition rod 10 is attached to an ignition plug 9. As shown in FIG. 2, the ignition rod 10, except for its tip, is covered with an insulating tube 11 made of an insulator so as to be insulated from surrounding components. When the burner 1 is ignited, a spark is generated at the tip of the ignition rod 10 to ignite the fuel-containing gas ejected from the nozzle pipe 40.

[0017] 1 to 6 , the ignition rod 10 is provided inside the first nozzle 3 of the multiple combustion nozzles 2 (3, 4). Furthermore, the ignition rod 10 is not provided in the second nozzle 4 of the multiple combustion nozzles 2 (3, 4) other than the first nozzle 3. That is, the multiple nozzle tubes 40 that form each of the multiple combustion nozzles 2 include a first nozzle tube 41 (the nozzle tube 40 that forms the first nozzle 3) through which the ignition rod 10 is inserted, and a second nozzle tube 42 (the nozzle tube 40 that forms the second nozzle 4 and through which the ignition rod 10 is not inserted) other than the first nozzle tube 41.

[0018] The nozzle plate 30 is provided inside the combustion liner 24 so as to extend along a plane perpendicular to the axial direction of the combustion liner 24. As shown in Fig. 2, the nozzle plate 30 has at least one hole 31 into which the tip ends (front ends) 41a, 42a of the nozzle pipes 40 (41, 42) can be fitted. The hole 31 is provided so as to penetrate the nozzle plate 30 in the axial direction.

[0019] 2 and 4 to 6, the tip ends (front ends) 41a, 42a of the nozzle pipes 40 (41, 42) are fitted into the holes 31 of the nozzle plate 30. In addition, the rear end (end opposite the tip ends 41a, 42a) of the nozzle pipes 40 (41, 42) is fitted into the holes 17 formed in the front plate 14 located rearward of the nozzle plate 30. In this way, the nozzle pipes 40 (41, 42) are supported so as to extend along the axial direction of the combustion liner 24.

[0020] A heat-resistant material 36 may be provided around the nozzle pipe 40 between the nozzle plate 30 and the front plate 14 .

[0021] The multiple combustion nozzles 2 (3, 4) may be arranged in a circumferential direction around the central axis O of the combustion tube 24, as shown in Fig. 3, for example. The multiple combustion nozzles 2 (3, 4) may also be arranged at different radial positions. In the example shown in Fig. 3, the multiple combustion nozzles 2 include a first nozzle 3 provided at the center in the radial direction, six second nozzles 4 arranged circumferentially on the inner circumferential side, and ten second nozzles 4 arranged circumferentially on the outer circumferential side.

[0022] In some embodiments, the first nozzle 3 does not have to be located at the center in the radial direction; for example, a plurality of combustion nozzles 2 arranged circumferentially may include one first nozzle 3 and a plurality of second nozzles 4.

[0023] A first gas containing fuel is supplied to the first nozzle 3 via a first gas passage 6. A second gas containing fuel or air is supplied to the second nozzle 4 via a second gas passage 8. The first gas and the second gas supplied to the first nozzle 3 and the second nozzle 4 may be fuel gas, air, or a premixed gas in which fuel and air are mixed in advance, respectively.

[0024] In the burner 1, a flame is generated by combustion of the gas containing fuel ejected from the outlets 3a, 4a of the first nozzle 3 and the second nozzle 4, and this flame is ejected from an opening 25 formed at the tip of the combustion tube 24. The flame F ejected from the combustion tube 24 in this manner heat-treats the workpiece 101.

[0025] The above-mentioned first gas passage 6 may include a flow path 13 formed by a pipe 12 provided 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.

[0026] The pipe 12 is provided so as to extend at least between the front plate 14 and the rear plate 16 provided behind the front plate 14. An ignition rod 10 provided inside the first nozzle 3 is inserted through the pipe 12. In the illustrated embodiment, the pipe 12 is provided so as to penetrate the rear plate 16. As shown in FIG. 2 , a male thread 44 is formed on the front end 12a of the pipe 12, and the end 12a may be screwed into a threaded hole 45 formed in the front plate 14, thereby fastening the pipe 12 to the front plate 14.

[0027] Alternatively, the pipe 12 may be connected to the front plate 14 by fitting the front end 12a of the pipe 12 into a hole formed in the front plate 14. An oil seal or the like may be installed at the fitting portion.

[0028] 8, the pipe 12 and the first nozzle pipe 41 may be integrally formed, and the pipe 12 and the first nozzle pipe 41 may be connected to the front plate 14 by fitting the integral pipe 12 and first nozzle pipe 41 into a hole 17 formed in the front plate 14. This allows the ignition rod 10 and the first nozzle pipe 41 to be pulled out as a unit from the combustion tube 24, making it easy to check the spark status outside the furnace. Furthermore, when the ignition rod 10 is inserted into the pipe 12 and the first nozzle pipe 41, the insulator at the tip of the ignition rod 10 (the insulating tube 11 and an ignition rod centering part, not shown) will not get caught on the step at the connection between the first nozzle pipe 41, the front plate 14, and the pipe 12. As shown in FIG. 8 , a seal portion 18 (e.g., an oil seal) may be provided between the pipe 12 and the first nozzle pipe 41 and the front plate 14 in the radial direction of the pipe 12 and the first nozzle pipe 41 in order to reduce gas leakage through the gap between the pipe 12 and the first nozzle pipe 41 and the front plate 14.

[0029] The first cylindrical member 20 is provided to extend axially behind the rear plate 16. The front end of the first cylindrical member 20 may be attached to the rear plate 16. Alternatively, the front end of the first cylindrical member 20 may be attached to the rear plate 16 by fitting the pipe 12 into the front end of the first cylindrical member 20 and fitting the pipe 12 into the rear plate 16. An opening at the rear end of the first cylindrical member 20 may be closed by inserting an ignition plug 9 into it.

[0030] The second gas passage 8 may include a second chamber 28 and a second inlet flow path 58. As shown in Fig. 1, the second chamber 28 may be formed by the front plate 14, the rear plate 16, and the inner wall surface of a second tubular member 22 extending axially between the front plate 14 and the rear plate 16. The second inlet flow path 58 may be formed by a second inlet pipe 56 connected to the second tubular member 22.

[0031] 1 is attached to a furnace wall 38. The furnace wall 38 may be at least partially formed of a heat insulating material.

[0032] In some embodiments, the hole forming portion of the nozzle plate 30 described above, in which the hole 31 into which the nozzle tube 40 is fitted is formed, contains SiC (silicon carbide) or graphite (carbon graphite), and the tip ends 41a, 42a of the nozzle tubes 40 (41, 42) contain an Fe—Cr—Al alloy. Here, the hole forming portion of the nozzle plate 30 refers to a portion that includes the inner wall surface of the hole 31. Furthermore, the tip ends 41a, 42a of the nozzle tubes 40 (41, 42) are portions of the nozzle tube 40 that are fitted into the hole 31 of the nozzle plate 30, and are portions that are located in an extension region of the nozzle plate 30 in the axial direction.

[0033] That is, in some embodiments, the hole forming portion of the nozzle plate 30 is made of SiC (silicon carbide) or graphite, and the tip portions 41a, 42a of the nozzle pipes 40 (41, 42) are made of an Fe-Cr-Al alloy.

[0034] In some embodiments, the hole forming portion of the nozzle plate 30 may be made of SiC (silicon carbide) or graphite, or the nozzle pipes 40 (41, 42) may be made of an Fe-Cr-Al alloy.

[0035] The SiC forming the hole forming portion of the nozzle plate 30 may include a pressureless sintered product or a reaction sintered product.

[0036] The Fe-Cr-Al alloy forming the tip portions 41a, 42a of the nozzle pipes 40 (41, 42) is an alloy containing 61 to 83 weight percent iron (Fe), 15 to 25 weight percent chromium (Cr), and 2 to 8 weight percent aluminum (Al). The Fe-Cr-Al alloy may further contain 3 weight percent or less molybdenum (Mo), 1 weight percent or less manganese (Mn), 1 weight percent or less silicon (Si), and / or 1 weight percent or less carbon (C).

[0037] Conventionally, when the nozzle plate becomes hot due to the operating conditions of the heat treatment equipment or the structure of the combustion tube, the nozzle plate and the nozzle tube fitted into the hole of the nozzle plate may adhere to each other. For example, in the case of a nozzle plate made of SiC and a nozzle tube made of high Cr-Ni steel, the reaction between SiC and the chromium (Cr) contained in the high Cr-Ni steel under high temperature conditions causes Cr ３ C ２ This adhesion between the nozzle plate and the nozzle pipe reduces the heat resistance of the nozzle, which may lead to burner failure due to deformation or thinning of the nozzle, or may cause problems with maintenance.

[0038] In this regard, in the above-described embodiment, the hole forming portion of the nozzle plate 30 is formed of SiC (silicon carbide) or graphite, and the tip portions 41a, 42a of the nozzle pipes 40 (41, 42) are formed of an Fe-Cr-Al alloy. Therefore, when the nozzle plate 30 becomes hot, aluminum oxide (Al ２ O ３This coating prevents the Cr at the nozzle tip from reacting with the C contained in the SiC or graphite, so it is possible to suppress adhesion between the nozzle plate and the nozzle tube even if the nozzle plate becomes hot.

[0039] In some embodiments, for example as shown in FIGS. 4-6, the combustion liner 24 may have a segmented structure including multiple members that are connected to one another.

[0040] 4 to 6, the combustion liner 24 includes a base member 60 that surrounds at least one nozzle tube 40, and a tip member 62 that has an opening 25 of the combustion liner 24. The base member 60 and the tip member 62 are connected to each other at a position axially distal to (i.e., forward of) the nozzle plate 30. The tip member 62 is located forward of the nozzle plate 30.

[0041] 4 to 6, the base member 60 has an inward flange 61 at its front end, and the tip member 62 has an outward flange 63 at its rear end. The base member 60 and the tip member 62 are connected by the surface 61 a of the inward flange 61 abutting against the surface 63 a of the outward flange 63.

[0042] When the combustion tube 24 has a divided structure including the base end member 60 and the tip end member 62, the temperature gradient in each member can be reduced, thereby suppressing the occurrence of cracks due to thermal stress, but the heat of the higher temperature tip end member 62 is less likely to be transferred to the base end member 60, so the temperatures of the tip end member 62 and the combustion chamber 23 tend to become high, and the nozzle plate 30 also tends to become high in temperature. In this regard, in the above-described embodiment, even though the combustion tube 24 includes the base end member 60 and the tip end member 62 and is configured so that the nozzle plate 30 tends to become high in temperature, as described above, adhesion between the nozzle plate 30 and the nozzle tubes 40 can be suppressed even if the nozzle plate 30 becomes high in temperature.

[0043] In some embodiments, as shown, for example, in FIGS. 2, 4 and 5, the burner 1 includes a thermal insulator 46 disposed between the combustion liner 24 and the nozzle plate 30.

[0044] In the exemplary embodiment shown in Fig. 2, a heat insulating material 46 is provided between the inner circumferential surface 24a of the combustion tube 24 and the outer circumferential surface 30a of the nozzle plate 30. In the exemplary embodiment shown in Fig. 4, a heat insulating material 46 is provided between the rear end surface 62a of the tip member 62 that constitutes the combustion tube 24 and the front end surface 30b of the nozzle plate 30. In the exemplary embodiment shown in Fig. 5, a heat insulating material 46 is provided between the inner circumferential surface 60a of the base end member 60 that constitutes the combustion tube 24 and the outer circumferential surface 30a of the nozzle plate 30, and between the rear end surface 62a of the tip member 62 and the front end surface 30b of the nozzle plate 30.

[0045] According to the above-described embodiment, the heat insulating material 46 is provided between the combustion liner 24 and the nozzle plate 30, so that heat from the combustion liner 24 is less likely to be transmitted to the nozzle plate 30. Therefore, even if the combustion liner 24 becomes hot, the nozzle plate 30 can be prevented from becoming hot. Therefore, adhesion between the nozzle plate 30 and the nozzle pipes 40 can be more effectively prevented.

[0046] As shown in Figures 1, 2 and 4 to 6, the combustion liner 24 may include a tapered portion 34 whose diameter gradually decreases axially from the nozzle plate 30 toward the opening 25 of the combustion liner 24.

[0047] In the exemplary embodiment shown in FIGS. 4 and 5 , the tapered portion 34 comprises a portion of a tip member 62 that defines the combustion liner 24 .

[0048] In the exemplary embodiment shown in FIG. 6 , the tapered portion 34 includes a first tapered portion 34a that is a part of the tip member 62 that constitutes the combustion tube 24, and a second tapered portion 34b that is a part of the base member 60. Each of the first tapered portion 34a and the second tapered portion 34b has a shape in which the diameter gradually decreases in the axial direction from the nozzle plate 30 toward the opening 25 of the combustion tube 24. In this case, when the axial distance between the nozzle plate 30 and the opening 25 of the combustion tube 24 is L1 (see FIG. 6 ), the second tapered portion 34b may be located within a range where the distance from the nozzle plate 30 in the axial direction is L1 / 2 or less. Alternatively, the axial distance L2 (see FIG. 6 ) between the nozzle plate 30 and the connection portion 64 of the tip member 62 and the base member 60 and the nozzle plate 30 may be ½ or less of the above-mentioned distance L1.

[0049] In some embodiments, a radial distance R2 (see FIGS. 2 to 6) between the center of each of the at least one hole 31 in the nozzle plate 30 and the central axis O of the combustion liner 24 is less than 80% of the maximum inner diameter R1 (see FIGS. 2 to 6) of the tapered portion 34 of the combustion liner 24. Alternatively, in some embodiments, each of the at least one hole 31 in 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.

[0050] FIG. 7 is a schematic diagram showing the flow of gas in the combustion chamber 23. According to the embodiment described above, since each of the holes 31 in the nozzle plate 30 is located relatively radially inward, as shown in FIG. 7 , a vortex F3 is formed in the region of the combustion chamber 23 radially outward of the holes 31 by the unburned fuel gas ejected from the nozzle tube 40 fitted in the hole 31 and the combustion gas in the combustion chamber. This vortex F3 is maintained at a relatively low temperature by contacting the nozzle plate 30, which has a temperature lower than the temperature of the flame formed in the combustion chamber 23. A portion of this relatively low-temperature vortex F3 is entrained by the main flow F1 of the gas ejected from the nozzle tube 40 and flows along the inner wall surface of the tapered portion 34, forming a relatively low-temperature gas film F2. This gas film F2 can suppress the transfer of heat from the high-temperature gas inside the combustion chamber 23 to the combustion liner 24. Therefore, the nozzle plate 30 can be more effectively prevented from becoming too hot, thereby more effectively suppressing adhesion between the nozzle plate 30 and the nozzle tube 40.

[0051] In some embodiments, for example as shown in Figures 1 to 6, the hole 31 of the nozzle plate 30 into which the second nozzle pipe 42 is fitted is located radially outward of the combustion liner 24 than the hole 31 of the nozzle plate 30 into which the first nozzle pipe 41 is fitted.

[0052] According to the above-described embodiment, the hole 31 of the nozzle plate 30 into which the first nozzle pipe 41, through which the ignition rod 10 is inserted, is fitted is located radially inward of the hole 31 of the nozzle plate 30 into which the second nozzle pipe 42, through which the ignition rod 10 is not inserted, is fitted. In other words, because the ignition rod 10 is provided near the central axis O of the combustion liner 24, a stable flame can be maintained. Furthermore, because the ignition rod 10 is provided near the central axis O of the combustion liner 24 as described above, the temperature distribution in the circumferential direction tends to be uniform. Therefore, the occurrence of cracks in the combustion liner 24 and the nozzle plate 30 can be more effectively suppressed.

[0053] In some embodiments, as shown in FIG. 2 , for example, the tip 10 a of the ignition rod 10 inserted into the first nozzle pipe 41 protrudes further toward the opening 25 of the combustion liner 24 than the nozzle plate 30 .

[0054] In this way, since the tip 10a of the ignition rod 10 protrudes toward the opening 25 of the combustion chamber 24 more than the nozzle plate 30, the tip of the ignition rod 10 can be used to properly detect the flame formed in the combustion chamber 23.

[0055] Furthermore, by exposing the tip of the ignition rod 10 to the combustion chamber 23, the tip of the ignition rod 10 can function as the detection part of a flame rod (flame detector), and can detect the presence or absence of a flame in the combustion chamber 23.

[0056] In the embodiment in which the tip 10a of the ignition rod 10 protrudes further toward the opening 25 of the combustion chamber 24 than the nozzle plate 30 as described above, the axial distance L3 (see Figure 2) between the tip 10a of the ignition rod 10 and the nozzle plate 30 may be 3 mm or more and 20 mm or less.

[0057] 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 tip of the ignition rod 10 can be used to properly detect the flame formed in the combustion chamber 23. 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-described embodiment, the ignition rod 10 can be protected while properly detecting the flame.

[0058] The burner 1 described above can be applied to various heat treatment facilities. Heat treatment facilities according to some embodiments include the burner 1 described above and a fuel line (not shown) for supplying fuel to the burner 1.

[0059] The heat treatment equipment according to one embodiment may be heat treatment equipment for heat treating a metal plate, and may be, for example, a continuous annealing equipment for a metal plate (e.g., a steel plate) or a continuous plating equipment for a metal plate (e.g., a steel plate), or a heating furnace included in these equipment.

[0060] In some embodiments, the metal plate heat treatment equipment further includes a conveying device (not shown) for conveying the metal plate as the workpiece 101, and the burner 1 is configured to heat the metal plate conveyed by the conveying device. The metal plate may be a strip-shaped metal band. In this case, the metal band may be continuously conveyed using rollers as the conveying device. The burner 1 may be configured to continuously heat-treat the metal band being conveyed by the rollers.

[0061] The contents described in each of the above embodiments can be understood, for example, as follows.

[0062] [1] A burner (1) according to at least one embodiment of the present invention comprises: a combustion liner (24) forming a combustion chamber (23) for burning fuel; at least one nozzle pipe (40) provided inside the combustion liner for ejecting gas containing the fuel or air into the combustion chamber; and a nozzle plate (30) extending inside the combustion liner along a plane perpendicular to the axial direction of the combustion liner and having at least one hole (31) into which a tip end of the at least one nozzle pipe is fitted, wherein a hole forming portion of the nozzle plate in which the at least one hole is formed contains SiC or graphite, and the tip end of the nozzle pipe contains an Fe-Cr-Al alloy.

[0063] According to the configuration [1] above, the hole forming portion of the nozzle plate is made of SiC (silicon carbide) or graphite, and the tip of the nozzle pipe is made of an Fe-Cr-Al alloy. Therefore, when the nozzle plate becomes hot, aluminum oxide (Al ２ O ３ This coating prevents the Cr at the nozzle tip from reacting with the C contained in the SiC or graphite, so it is possible to suppress adhesion between the nozzle plate and the nozzle tube even if the nozzle plate becomes hot.

[0064] [2] In some embodiments, in the configuration of [1] above, the combustion tube includes a base end member (60) surrounding the at least one nozzle pipe, and a tip end member (62) having an opening (25) of the combustion tube, and the base end member and the tip end member are connected to each other at a position further tip than the nozzle plate in the axial direction of the combustion tube.

[0065] When the combustion tube has a divided structure including a base end member and a tip end member, the temperature gradient in each member can be reduced, thereby suppressing the occurrence of cracks due to thermal stress, but because the heat from the higher temperature tip end member is less likely to transfer to the base end member, the temperatures of the tip end member and the combustion chamber tend to become high, and the nozzle plate also tends to become high. In this regard, according to the configuration [2] above, even though the combustion tube includes a base end member and a tip end member and the nozzle plate is configured to easily become high in temperature, as described in [1] above, adhesion between the nozzle plate and the nozzle tube can be suppressed even if the nozzle plate becomes high in temperature.

[0066] [3] In some embodiments, in the configuration of [1] or [2] above, the at least one nozzle tube includes a first nozzle tube (41) through which an ignition rod (10) is inserted, and a second nozzle tube (42) other than the first nozzle tube, and the hole in the nozzle plate into which the second nozzle tube is fitted is located radially outward of the combustion tube than the hole in the nozzle plate into which the first nozzle tube is fitted.

[0067] According to the configuration [3] above, the hole in the nozzle plate into which the first nozzle pipe, through which the ignition rod is inserted, is fitted is located radially inward of the hole in the nozzle plate into which the second nozzle pipe, through which the ignition rod is not inserted, is fitted. In other words, since the ignition rod is located near the central axis of the combustion liner, a stable flame can be maintained. Furthermore, since the ignition rod is located near the central axis of the combustion liner as described above, the temperature distribution in the circumferential direction tends to be uniform. Therefore, the occurrence of cracks in the combustion liner and the nozzle plate can be more effectively suppressed.

[0068] [4] In some embodiments, in the configuration of any one of [1] to [3] above, a heat insulating material (46) is provided between the combustion liner and the nozzle plate.

[0069] According to the configuration [4] above, since a heat insulating material is provided between the combustion liner and the nozzle plate, heat from the combustion liner is less likely to transfer to the nozzle plate. Therefore, even if the combustion liner becomes hot, the nozzle plate can be prevented from becoming too hot. Therefore, adhesion between the nozzle plate and the nozzle pipe can be more effectively prevented.

[0070] [5] In some embodiments, in any of the configurations [1] to [4] above, the combustion tube includes a tapered portion (38) whose diameter gradually decreases from the nozzle plate toward the opening of the combustion tube in the axial direction of the combustion tube, and a radial distance R2 between the center of the at least one hole in the nozzle plate and the central axis of the combustion tube is less than 80% of the maximum inner diameter R1 of the tapered portion.

[0071] According to the configuration [5] above, since the nozzle plate hole is located relatively radially inward, a vortex is formed in the region of the combustion chamber radially outward of the hole by the unburned fuel gas ejected from the nozzle pipe fitted to the hole and the combustion gas in the combustion chamber. This vortex is maintained at a relatively low temperature by contacting the nozzle plate, which is cooler than the temperature of the flame formed in the combustion chamber. A portion of this relatively low-temperature vortex is entrained by the main flow of gas ejected from the nozzle pipe and flows along the inner wall surface of the tapered section, forming a relatively low-temperature gas film. This gas film can suppress the transfer of heat from the high-temperature gas in the combustion chamber to the combustion liner. This can more effectively suppress the nozzle plate from becoming too hot, thereby more effectively suppressing adhesion between the nozzle plate and the nozzle pipe.

[0072] [6] In some embodiments, in any of the configurations [1] to [5] above, the at least one nozzle pipe includes a first nozzle pipe (41) through which an ignition rod is inserted, and a tip (10a) of the ignition rod protrudes toward the opening of the combustion tube beyond the nozzle plate.

[0073] According to the configuration [6] above, the tip of the ignition rod protrudes further toward the opening of the combustion chamber than the nozzle plate, so that the tip of the ignition rod can be used to properly detect the flame formed in the combustion chamber.

[0074] [7] In some embodiments, in the configuration of [8] above, the distance (L3) in the axial direction between the tip of the ignition rod and the nozzle plate is 3 mm or more and 20 mm or less.

[0075] In the configuration [7] above, the axial distance between the tip of the ignition rod and the nozzle plate is 3 mm or more, so the tip of the ignition rod can be used to properly detect the flame formed in the combustion chamber. Also, in the configuration [7] above, the axial distance between the tip of the ignition rod and the nozzle plate is 20 mm or less, so the ignition rod is not exposed to excessively high temperatures. Therefore, the configuration [7] above allows proper flame detection while protecting the ignition rod.

[0076] [8] In some embodiments, in the configuration of [2] above, the combustion tube includes a tapered portion (34) whose diameter gradually decreases from the nozzle plate toward the opening of the combustion tube in the axial direction of the combustion tube, and the tapered portion includes a first tapered portion (34a) formed by the tip member and a second tapered portion (34b) formed by the base member.

[0077] According to the configuration [8] above, even if the burner has a configuration in which the connection position between the base end member and the tip member is located relatively toward the tip, such that a part of the base end member (second tapered portion) forms a tapered portion, as described in [1] above, adhesion between the nozzle plate and the nozzle tube can be suppressed even if the nozzle plate becomes hot.

[0078] [9] In some embodiments, in the configuration of [8] above, when the axial distance between the nozzle plate and the opening of the combustion liner is L1, the second tapered portion is located within a range where the distance from the nozzle plate in the axial direction is L1 / 2 or less.

[0079] According to the configuration [9] above, even if the burner has a configuration in which the connection position between the base end member and the tip member is located relatively toward the tip, such that a part of the base end member (second tapered portion) forms a tapered portion, as described in [1] above, adhesion between the nozzle plate and the nozzle tube can be suppressed even if the nozzle plate becomes hot.

[0080]

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

[0081] According to the configuration of

[10] above, the hole forming portion of the nozzle plate is made of SiC (silicon carbide) or graphite, and the tip of the nozzle pipe is made of an Fe-Cr-Al alloy. Therefore, when the nozzle plate becomes hot, aluminum oxide (Al ２ O ３ Therefore, even if the nozzle plate becomes hot, adhesion between the nozzle plate and the nozzle pipe can be suppressed.

[0082] The above describes an embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and also includes forms in which the above-described embodiment is modified, or forms in which these forms are appropriately combined.

[0083] In this specification, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "identical," "equal," and "homogeneous," not only express a state in which there is a strict equivalence, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions expressing shapes such as a rectangular shape or a cylindrical shape not only express shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0084] REFERENCE SIGNS LIST 1 burner 2 combustion nozzle 3 first nozzle 3a outlet 4 second nozzle 4a outlet 6 first gas passage 8 second gas passage 9 spark plug 10 ignition rod 10a tip 11 insulating tube 12 pipe 12a end 13 flow path 14 front plate 16 rear plate 17 hole 18 seal portion 20 first cylindrical member 22 second cylindrical member 23 combustion chamber 24 combustion liner 24a inner peripheral surface 25 opening 26 first chamber 28 second chamber 30 nozzle plate 30a outer peripheral surface 30b front end surface 31 hole 34 tapered portion 34a first tapered portion 34b second tapered portion 36 heat-resistant material 38 furnace wall 40 nozzle pipe 41 first nozzle pipe 41a tip portion 42 Second nozzle pipe 42a Tip portion 44 Male thread 45 Threaded hole 46 Heat insulating material 52 First inlet pipe 54 First inlet flow path 56 Second inlet pipe 58 Second inlet flow path 60 Base end member 60a Inner peripheral surface 61 Inward flange 61a Surface 62 Tip member 62a Rear end surface 63 Outward flange 63a Surface 64 Connection portion 101 Workpiece F Flame F1 Main flow F2 Gas film F3 Swirl L1 Distance L2 Distance L3 Distance O Central axis R1 Maximum inner diameter R2 Distance

Claims

1. A burner comprising: a combustion tube forming a combustion chamber for burning fuel; at least one nozzle tube provided inside said combustion tube for ejecting gas containing said fuel or air into said combustion chamber; and a nozzle plate extending inside said combustion tube along a plane perpendicular to the axial direction of said combustion tube and having at least one hole into which a tip end of said at least one nozzle tube is respectively fitted, wherein a hole forming portion of said nozzle plate in which said at least one hole is formed comprises SiC or graphite, and said tip end of said nozzle tube comprises an Fe-Cr-Al based alloy.

2. A burner as described in claim 1, wherein the combustion tube includes a base end member surrounding the at least one nozzle tube and a tip end member having an opening of the combustion tube, and the base end member and the tip end member are connected to each other at a position further tip than the nozzle plate in the axial direction of the combustion tube.

3. A burner as claimed in claim 1 or 2, wherein the at least one nozzle tube includes a first nozzle tube through which an ignition rod is inserted and a second nozzle tube other than the first nozzle tube, and the hole in the nozzle plate into which the second nozzle tube is fitted is provided radially outward of the combustion tube than the hole in the nozzle plate into which the first nozzle tube is fitted.

4. A burner as claimed in claim 1 or 2, further comprising a heat insulating material provided between said combustion tube and said nozzle plate.

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

6. A burner as claimed in claim 1 or 2, wherein the at least one nozzle tube includes a first nozzle tube through which an ignition rod is inserted, and a tip of the ignition rod protrudes further towards the opening of the combustion tube than the nozzle plate.

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

8. A burner as described in claim 2, wherein the combustion tube includes a tapered portion whose diameter gradually decreases from the nozzle plate toward the opening of the combustion tube in the axial direction of the combustion tube, the tapered portion including: a first tapered portion formed by the tip member; and a second tapered portion formed by the base member.

9. A burner as described in claim 8, wherein when the axial distance between the nozzle plate and the opening of the combustion tube is L1, the second tapered portion is located within a range where the distance from the nozzle plate in the axial direction is L1 / 2 or less.

10. A heat treatment facility comprising: a burner according to claim 1 or 2; and a fuel supply line for supplying fuel to the burner.

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