Gas burner and boiler comprising the same

Abstract

To provide a gas burner that can keep sealability of a seal part in a through hole through which a burner body penetrates a wind box even if a relative displacement between the burner body and the wind box is changed.SOLUTION: A gas burner 1 comprises: a wind box 3 to which combustion air is supplied; and a burner body 5 that is provided inside the wind box 3, and supplies fuel gas to a furnace 7 of a boiler. The burner body 5 comprises: a tip part 5a supported toward the furnace 7; and a base end part 5b connected to the tip part 5a, extending to a base end side, and penetrating a through hole 9 provided in a rear wall part 3a of the wind box 3. Between the rear wall part 3a and the base end part 5b in the through hole 9, a seal part 20 for airtightly sealing a gap between them is provided. The seal part 20 comprises packing 26 for allowing a relative movement between the rear wall part 3a and the base end part 5b, and sealing the gap by being pressed between the rear wall part 3a and the base end part 5b.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a gas burner and a boiler equipped with the same. [Background technology]

[0002] A gas burner that supplies fuel gas to a boiler to form a flame is known (Patent Document 1). Patent Document 1 discloses an invention related to reducing gas leakage caused by differential thermal expansion in a flange portion that connects a burner panel to a wind box that houses multiple burner nozzles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-110829 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in Patent Document 1, gas burners require leakage countermeasures for the wind box to prevent fuel gas leakage. Patent Document 1 considers leakage countermeasures between the furnace wall (burner panel) and the wind box, but it is also necessary to consider the sealing performance of the seal part in the through hole that penetrates the burner body from the wind box to the outside of the furnace.

[0005] The sealing performance of the above seal portion is degraded by the relative displacement caused by the thermal expansion difference between the burner body and the wind box. Also, the support portion that supports the burner body from the outside of the wind box causes a relative displacement between the wind box, which thermally deforms together with the furnace, and the support portion generates a load on the seal portion, which may degrade the sealing performance.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a gas burner and a boiler equipped with the same that can maintain the sealing property of the sealing portion in the through hole through which the burner body passes through the wind box even if the relative displacement between the burner body and the wind box changes. [Means for solving the problem]

[0007] A gas burner according to one aspect of the present disclosure comprises a wind box to which combustion air is supplied, and a burner body provided inside the wind box and supplying fuel gas to a furnace of a boiler, the burner body comprising a tip end supported toward the furnace, and a base end connected to the tip end and extending toward the base end to pass through a through hole provided in a rear wall of the wind box, and a seal portion is provided between the rear wall and the base end at the through hole to hermetically seal them, and the seal portion comprises a gasket which allows relative movement between the rear wall and the base end and is pressed between the rear wall and the base end to provide a seal.

[0008] A gas burner according to one aspect of the present disclosure comprises a wind box to which combustion air is supplied, and a burner body provided inside the wind box and supplying fuel gas to a furnace of a boiler, the burner body comprising a tip portion supported toward the furnace, and a base portion connected to the tip portion and extending toward the base end to pass through a through hole provided in a rear wall portion of the wind box, a seal portion for airtightly sealing the rear wall portion and the base portion is provided in the through hole, the seal portion comprising a flange portion provided around the base portion, a shaft portion that passes through a hole formed in the flange portion and is fixed to the rear wall portion and has a male thread, and a nut portion that is screwed onto the shaft portion and presses and fixes the flange portion against the rear wall portion, the size of the hole portion being set according to the width or height of the burner so as to ensure a clearance for a thermal expansion difference between the wind box and the burner body in the axial direction and in a direction perpendicular to the axial direction.

[0009] A boiler according to one aspect of the present disclosure includes a boiler body and any one of the above-mentioned gas burners provided to the boiler body. Effect of the Invention

[0010] Even if the relative displacement between the burner body and the wind box changes, the sealing performance of the seal part in the through hole through which the burner body passes through the wind box can be maintained. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a gas burner according to a first embodiment of the present disclosure. [Diagram 2] 2 is a front view of the burner body of FIG. 1 as viewed from the front end side. FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 3 is a cross-sectional view taken along line VV in FIG. 2. [Figure 6] FIG. 4 is an enlarged view of an area S enclosed in a dashed square in FIG. [Figure 7] FIG. 7 is a cross-sectional view of the base end at the location of the packing in FIG. 6. [Figure 8] FIG. 13 is a rear view of the gas burner as viewed from the rear wall portion of the comparative example. [Figure 9] FIG. 4 is a cross-sectional view showing a comparative example and a gas burner corresponding to FIG. 3. [Figure 10] FIG. 4 is a perspective view showing a gas burner according to a second embodiment of the present disclosure. [Figure 11] 11 is a partially enlarged vertical sectional view showing a flange portion of FIG. 10 in an enlarged manner. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [First embodiment] The first embodiment of the present disclosure will be described below. A gas burner 1 provided in a boiler is shown in Fig. 1. In the figure, the gas burner 1 is shown as viewed from the rear side (the side opposite the furnace).

[0013] The gas burner 1 comprises an air box 3 into which the combustion air is introduced, and a burner body 5 through which the fuel gas and the combustion air flow. In the figure, the left side of the gas burner 1 is the boiler furnace 7. The furnace 7 side is the tip side of the gas burner 1, and the opposite side (the right side in the figure) is the base end side of the gas burner 1.

[0014] The wind box 3 is attached to the wall of the boiler and houses the burner body 5 inside. Combustion air is supplied to the inside of the wind box 3 and is fed into the furnace 7 of the boiler. The combustion air is heated by heat exchange with the combustion gas generated in the boiler, and is kept at a temperature of about 300°C.

[0015] The burner body 5 includes a tip portion 5a located on the tip side, and a base end portion 5b connected to the tip portion and extending to the base end side (the right side in FIG. 1).

[0016] A through hole 9 is formed in the rear wall 3a of the wind box 3, and the base end 5b of the burner body 5 is inserted into this through hole 9. A seal portion 20 is provided in the through hole 9 to airtightly seal between the rear wall 3a and the base end 5b. As shown by the dashed line in Fig. 1, the seal portion 20 is provided around the entire periphery of the base end 5b, which has a rectangular cross section. The configuration of the seal portion 20 will be described later.

[0017] A guide pipe 15 for an igniter (ignition device) and an attachment portion 17 for a flame detector 16 that detects the flame formed by the gas burner 1 are provided on the rear wall portion 3a.

[0018] Fig. 2 shows a front view of the burner body 5 of the gas burner 1 in Fig. 1 from the tip portion 5a side. As shown in Fig. 2, the burner body 5 has a plurality of fuel gas supply ports 11 and a plurality of air supply ports 12. The fuel gas supply port 11 is a flow path for supplying fuel gas to the furnace 7 (see Fig. 1). The air supply port 12 is a flow path for supplying combustion air to the furnace 7 (see Fig. 1).

[0019] Each fuel gas supply inlet 11 and each air supply inlet 12 is partitioned into, for example, 22 sections by partition plates 10a extending along the horizontal direction HD and partition plates 10b extending along the vertical direction VD. The fuel gas supply inlets 11 and the air supply inlets 12 are arranged alternately in both the horizontal direction HD and the vertical direction VD. Fuel gas and combustion air are introduced into each fuel gas supply inlet 11 and each air supply inlet 12 from a supply source (not shown).

[0020] Fig. 3 shows a cross section taken along line III-III in Fig. 2. The fuel gas supply ports 11 shown in Fig. 3 are two fuel gas supply ports 11 adjacent to each other in the horizontal direction HD and adjacent to each other in the vertical direction VD as shown along line III-III in Fig. 2. These two adjacent fuel gas supply ports 11 are connected to a single common fuel gas flow path 13. The fuel gas G introduced into the fuel gas flow path 13 branches and is introduced to each fuel gas supply port 11.

[0021] 3, an igniter 18 inserted into a guide pipe 15 is provided above the fuel gas flow path 13. A heat insulating material 19 is provided on the inner side of the wind box 3 at the rear wall portion 3a.

[0022] A base end 5b of the burner body 5 is connected to the upstream side (right side in FIG. 3) of the fuel gas flow passage 13 of a fuel gas supply port 11 constituting the tip end 5a of the burner body 5. The base end 5b of the burner body 5 passes through a through hole 9 formed in the rear wall 3a of the wind box 3. As shown in FIG. 5, the base end 5b passing through the through hole 9 is extended to the outside of the wind box 3 and is connected to a supply source of fuel gas G (not shown).

[0023] Fig. 4 shows a cross section taken along line IV-IV in Fig. 2. The air supply ports 12 shown in Fig. 4 are two air supply ports 12 adjacent to each other in the horizontal direction HD and adjacent to each other in the vertical direction VD as shown along line IV-IV in Fig. 2. These two adjacent air supply ports 12 are connected to air introduction spaces 24 formed above and below the fuel gas flow path 13. The combustion air A introduced into the air introduction space 24 branches and is introduced to each air supply port 12.

[0024] Fig. 5 shows a cross section taken along the VV cutting line in Fig. 2. As shown in Fig. 5, the fuel gas G flowing into the fuel gas flow passage 13 from the base end 5b of the burner body 5 is supplied to the furnace 7 via the fuel gas supply port 11. The combustion air A is guided from the air supply passage 22 formed on the side of the wind box 3 to the air introduction space 24 (see Fig. 4) and then supplied to the furnace 7 via each air supply port 12.

[0025] <Sealing part 20> 1 and 3, a seal portion 20 that provides airtightness between the base end portion 5b and the rear wall portion 3a is provided in the through hole 9. Fig. 6 is an enlarged view of an area S enclosed by a dashed square in Figs. 3 and 4.

[0026] As shown in Figure 6, the sealing portion 20 includes a gasket 26, a stopper 28 provided on the tip side (left side in the figure) of the base end 5b of the burner body 5 relative to the gasket 26, and a gasket retainer 30 provided on the base side (right side in the figure) of the base end 5b relative to the gasket 26.

[0027] The packing 26 is in the form of a long, thin string, and is formed by braiding, for example, various types of fiber threads. Note that, although the cross-sectional shape of the packing 26 is round in Fig. 6, it may be other shapes, such as a square.

[0028] As shown in Fig. 7, the packing 26 is wound around the outer periphery of the base end 5b, which has a rectangular cross section. In Fig. 6, the packing 26 is wound three times in the longitudinal direction of the base end 5b (horizontal direction in Fig. 6), but it may be wound two or four or more times. The packing 26 may be wound two or more times using a continuous string, or multiple C-shaped strings may be arranged overlapping each other in the longitudinal direction of the base end 5b. When multiple C-shaped strings are used, they are arranged so that the strings are not continuous in the C shape and the missing position does not overlap the missing position of the adjacent C-shaped string.

[0029] Stopper 28 is fixed to the outer periphery of base end 5b by welding or the like. Stopper 28 is provided around the entire outer periphery of base end 5b. Stopper 28 prevents packing 26 from moving towards the tip side. Note that stopper 28 may be provided on part of the outer periphery of base end 5b (on all four sides of the outer periphery of base end 5b, at a paired position on the outer periphery, etc.) as long as it is possible to prevent packing 26 from moving.

[0030] The packing gland 30 is provided around the entire outer periphery of the base end 5b. When viewed in vertical cross section as in Fig. 6, the packing gland 30 is L-shaped and includes a pressing portion 30a extending along the outer surface of the base end 5b, a flange portion 30b connected to the pressing portion 30a and extending along the rear wall portion 3a, and a bolt (adjustment portion) 30c inserted into the flange portion 30b.

[0031] The tip of the pressing portion 30a (the left end in the figure) passes through the through hole 9 from the rear wall portion 3a and enters the inside of the wind box 3, and presses down the end portion on the base end side of the packing 26. The bolt 30c passes through a bolt hole formed in the flange portion 30b and is screwed into the rear wall portion 3a. By rotating the bolt 30c, the pressing portion 30a is moved forward and backward relative to the packing 26. In other words, the distance of the pressing portion 30a from the stopper 28 can be adjusted by rotating the bolt 30c.

[0032] By rotating the bolt 30c and pressing the packing 26 between the stopper 28 and the packing gland 30, the base end 5b and the rear wall 3a are airtightly sealed at the through hole 9. Since the packing gland 30 is connected to the rear wall 3a and the stopper 28 is connected to the base end 5b, the sealing performance is maintained with the packing 26 pressed down by the packing gland 30 even if the base end 5b and the rear wall 3a are displaced relative to each other.

[0033] The effects of the present embodiment described above are as follows. 8 shows a comparative example of the present embodiment, in which welding is used as a seal that does not allow relative displacement between the base end 5b and the rear wall 3a, unlike the seal 20 of the present embodiment. As shown in the figure, a weld W is provided around the entire circumference of the through hole 9 between the base end 5b and the rear wall 3a.

[0034] When the gas burner 1 is started and the temperature of the burner body 5 rises, the combustion air A is supplied into the wind box 3, so the temperature does not rise as much as the burner body 5, resulting in a temperature difference. When the burner body 5 is heated, the base end 5b thermally expands and tries to deform in all directions in the direction of the thick arrows. On the other hand, the rear wall 3a is cooled by the combustion air A, so it does not thermally expand like the base end 5b, and prevents displacement due to thermal expansion of the base end 5b. This causes stress in the welded part W, which may concentrate at the corners of the welded part W and cause cracks BR.

[0035] As shown in Fig. 9, the burner body 5 has its base end 5b side suspended from a frame (support structure) by a hanger 33 outside the wind box 3. The frame is a structure that suspends the entire boiler body from above. An expansion 35 is provided next to the hanger 33 to absorb displacement.

[0036] When the boiler starts, the boiler body suspended from the frame is displaced downward (see arrow A1) due to thermal expansion. Accordingly, the wind box 3 fixed to the boiler body is also displaced downward. On the other hand, the base end 5b suspended from the hanger 33 is not affected by the thermal expansion of the boiler body because the hanger 33 is attached to the frame. Therefore, the suspension position of the base end 5b by the hanger 33 does not change, so the base end 5b suspended from the hanger 33 is pulled upward (see arrow A2) relative to the wind box 3 displaced downward. As a result, stress is generated between the base end 5b at the through hole 9 and the rear wall 3a of the wind box 3.

[0037] Furthermore, the expansion 35 is bent and deformed due to the relative displacement between the wind box 3 and the base end 5b at the hanging position of the hanger 33, and a reaction force due to this bending deformation is generated between the base end 5b at the through hole 9 and the rear wall 3a of the wind box 3.

[0038] As described above, in the comparative example shown in Figures 8 and 9, sealing is performed by the welded portion W. When thermal deformation is taken into consideration, the relative displacement between the rear wall portion 3a and the base end portion 5b may cause stress to be generated at the welded portion W, which may result in damage.

[0039] In contrast, the sealing portion 20 of the present embodiment allows relative movement between the rear wall portion 3a and the base end portion 5b, and an elastic gasket 26 is pressed between the rear wall portion 3a and the base end portion 5b, so that the sealing properties of the sealing portion 20 can be maintained even if relative displacement occurs between the rear wall portion 3a and the base end portion 5b due to thermal expansion.

[0040] The packing 26 is wound around the base end 5b to prevent gas leakage from the periphery of the base end 5b. The packing 26 is sandwiched and pressed between the stopper 28 and the packing gland 30 to effectively exert a sealing property.

[0041] The packing gland 30 is provided with a bolt 30c that can adjust the distance from the stopper 28. This allows the amount of pressure applied to the packing 26 to be adjusted, and if the amount of pressure applied to the packing 26 decreases during periodic inspection, the amount of pressure can be readjusted by using the bolt 30c.

[0042] [Second embodiment] Next, a second embodiment of the present disclosure will be described. This embodiment differs from the first embodiment in the configuration of the seal portion, but is otherwise similar. Therefore, in the following, the same components as those in the first embodiment are given the same reference numerals and their description will be omitted.

[0043] 10, the seal portion 40 of this embodiment has a flange structure. That is, the seal portion 40 includes a flange portion 42 provided on the base end portion 5b, a shaft portion 44, and a nut 46 screwed onto the shaft portion 44.

[0044] The flange portion 42 is provided around the entire outer periphery of the base end portion 5b, and is fixed to the base end portion 5b by, for example, welding.

[0045] As shown in FIG. 11, the flange portion 42 is formed with a hole 42a through which the shaft portion 44 penetrates. The size of the hole 42a is set according to the width or height of the burner body 5 so as to ensure a clearance for the thermal expansion difference between the axial direction of the wind box 3 and the burner body 5 and the direction perpendicular to the axial direction. The thermal expansion difference is the thermal expansion difference between when the boiler and the burner are stopped and when they are started. The clearance is made larger than a hole of a general size formed to insert a bolt into the flange. The shape of the hole 42a may be round, elliptical, or oval. However, the minimum diameter of the hole 42a is set according to the width or height of the burner so as to ensure a clearance for the thermal expansion difference between the axial direction of the wind box 3 and the burner body 5 and the direction perpendicular to the axial direction. Here, the axial direction of the burner body 5 is the flow direction of the fuel gas G flowing from the base end portion 5b to the tip end portion 5a, and is perpendicular to the vertical direction VD.

[0046] 11, the shaft portion 44 is fixed to the rear wall portion 3a by welding or the like, and is disposed so as to pass through the hole portion 42a. A male screw is formed on the outer periphery of the shaft portion 44.

[0047] The nut 46 is screwed onto the shaft portion 44 to press and fix the flange portion 42 against the rear wall portion 3a. A washer 48 is provided between the nut 46 and the flange portion 42. The washer 48 has a shape larger than the hole portion 42a. Although not shown, a gasket is inserted between the flange portion 42 and the rear wall portion 3a to effectively achieve an airtight seal.

[0048] The effects of the present embodiment described above are as follows. The base end 5b is fixed to the rear wall 3a by the flange 42 to provide an airtight seal. At this time, the hole 42a formed in the flange 42 is set according to the width or height of the burner so as to ensure a clearance for the thermal expansion difference between the wind box and the burner body in the axial direction and in the direction perpendicular to the axial direction, so that the shaft 44 is allowed to move within the range of the size of the hole 42a even if a relative displacement occurs between the rear wall 3a and the base end 5b. This allows the sealing performance of the seal portion 40 to be maintained even if a relative displacement occurs between the rear wall 3a and the base end 5b.

[0049] The gas burner and the boiler including the gas burner according to each of the above-described embodiments can be understood, for example, as follows.

[0050] A gas burner (1) according to a first aspect of the present disclosure comprises a wind box (3) to which combustion air is supplied, and a burner body (5) provided inside the wind box (3) and configured to supply fuel gas to a furnace (7) of a boiler. The burner body (5) comprises a tip end (5a) supported toward the furnace (7), and a base end (5b) connected to the tip end (5a) and extending toward the base end to pass through a through hole (9) provided in a rear wall portion (3a) of the wind box (3). A seal portion (20) is provided between the rear wall portion (3a) and the base end portion (5b) at the through hole (9) to hermetically seal them, and the seal portion (20) comprises a packing (26) which allows relative movement between the rear wall portion (3a) and the base end portion (5b) and which is pressed against the rear wall portion (3a) and the base end portion (5b) to provide a seal.

[0051] A seal portion is provided in the through hole to hermetically seal between the rear wall portion and the base end portion. The seal portion allows relative movement between the rear wall portion and the base end portion and is pressed between the rear wall portion and the base end portion, so that the sealing performance of the seal portion can be maintained even if relative displacement occurs between the rear wall portion and the base end portion.

[0052] In the gas burner (1) according to the second aspect of the present disclosure, in the above-mentioned first aspect, the gasket (26) is wound around the base end (5b), the seal portion (20) is fixed to the base end (5b), and is provided with a stopper (28) that prevents the gasket (26) from moving toward the tip end (5a), and a gasket retainer (30) that is fixed to the rear wall portion (3a) and presses and holds the gasket (26) against the stopper (28).

[0053] The packing is wrapped around the base end to prevent gas leakage around the base end. The packing can effectively exhibit sealing properties by being sandwiched and pressed between the stopper and the packing gland.

[0054] A gas burner (1) according to a third aspect of the present disclosure is the gas burner (1) of the second aspect, wherein the packing gland (30) includes an adjustment portion (30c) capable of adjusting the distance from the stopper (28).

[0055] The packing gland has an adjustment section that allows the distance from the stopper to be adjusted, which makes it possible to adjust the amount of pressure applied to the packing, and if the amount of pressure applied to the packing decreases during periodic inspections, the amount of pressure can be readjusted. The adjustment portion may be, for example, a bolt.

[0056] A gas burner (1) according to a fourth aspect of the present disclosure includes a wind box (3) to which combustion air is supplied, and a burner body (5) provided inside the wind box (3) and configured to supply fuel gas to a furnace (7) of a boiler. The burner body (5) includes a tip portion (5a) supported so as to face the furnace (7), and a base portion (5b) connected to the tip portion (5a) and extending toward the base end to pass through a through hole (9) provided in a rear wall portion (3a) of the wind box (3). A seal portion (40) is provided between the rear wall portion (3a) and the base portion (5b) at the through hole (9) to airtightly seal them. The seal portion (40) comprises a flange portion (42) provided around the base end portion (5b), a shaft portion (44) which penetrates a hole portion (42a) formed in the flange portion (42) and is fixed to the rear wall portion (3a) and has a male thread, and a nut portion (46) which is screwed onto the shaft portion (44) and presses and fixes the flange portion (42) against the rear wall portion (3a). The size of the hole portion (42a) is set according to the width or height of the burner so as to ensure a clearance for the thermal expansion difference between the wind box and the burner body in the axial direction and in the direction perpendicular to the axial direction.

[0057] The base end is fixed to the rear wall by a flange to provide an airtight seal. At this time, the hole formed in the flange is set according to the width or height of the burner so as to ensure a clearance for the thermal expansion difference between the wind box and the burner body in the axial direction and in the direction perpendicular to the axial direction. Therefore, even if a relative displacement occurs between the rear wall and the base end, the shaft can move within the range of the size of the hole, so that the sealing performance of the seal can be maintained.

[0058] A boiler according to a first aspect of the present disclosure includes a boiler body and any of the above-described gas burners (1) provided to the boiler body. [Explanation of symbols]

[0059] 1 Gas burner 3 Wind box 3a Rear wall 5 Burner body 5a Tip 5b Proximal end 7 Furnace 9 Through holes 10a Partition 10b Partition plate 11 Fuel gas supply port 12 Air supply port 15 Guide pipe 16 Flame Detector 17 Mounting part 18 Igniter 19 Insulation 20 Seal part 22 Air supply line 24 Air intake space 26 Packing 28 Stopper 30 Packing gland 30a Presser section 30b Tsubabe 30c Bolt (adjustment part) 33 Hanger 35 Expansion 40 Seal part 42 Flange part 42a Hole 44 Shaft 46 Nut 48 Washer A Combustion air G Fuel gas

Claims

1. a wind box to which combustion air is supplied; a burner body provided inside the wind box and configured to supply fuel gas to a furnace of a boiler; Equipped with The burner body includes a tip portion supported toward the furnace and a base end portion connected to the tip portion and extending toward the base end side to pass through a through hole provided in a rear wall portion of the wind box, a seal portion is provided between the rear wall portion and the base end portion of the through hole to air-tightly seal them, The sealing portion is provided with a packing that allows relative movement between the rear wall portion and the base end portion and is pressed between the rear wall portion and the base end portion to form a seal.

2. The packing is wound around the base end, The sealing portion is a stopper fixed to the base end portion to prevent the packing from moving toward the tip end portion; a packing gland fixed to the rear wall portion and configured to bias and hold the packing against the stopper; 2. The gas burner of claim 1, comprising:

3. 3. The gas burner according to claim 2, wherein the packing gland has an adjustment portion that allows a distance from the stopper to be adjusted.

4. a wind box to which combustion air is supplied; a burner body provided inside the wind box and configured to supply fuel gas to a furnace of a boiler; Equipped with The burner body includes a tip portion supported toward the furnace and a base end portion connected to the tip portion and extending toward the base end side to pass through a through hole provided in a rear wall portion of the wind box, a seal portion is provided between the rear wall portion and the base end portion of the through hole to air-tightly seal them, The seal portion includes a flange portion provided around the base end portion, a shaft portion having a male thread that is inserted through a hole formed in the flange portion and fixed to the rear wall portion, and a nut portion that is screwed onto the shaft portion and presses and fixes the flange portion against the rear wall portion. Equipped with A gas burner in which the size of the hole is set according to the width or height of the burner so as to ensure a clearance for the thermal expansion difference between the wind box and the burner body in the axial direction and in the direction perpendicular to the axial direction.

5. A boiler body, The gas burner according to claim 1 or 4, which is provided to the boiler body; A boiler equipped with:

Images