Flue gas premixing staggered-layer low-nitrogen gas burner

Abstract

The utility model relates to the technical field of combustors, and discloses a flue gas premixing staggered-layer low-nitrogen gas combustor which comprises a tray frame, a shell and a mixing cavity, the shell is installed on one side of the tray frame, the mixing cavity is installed on the other side of the tray frame, the shell is of a hollow structure, the end, away from a lower tray, of the shell is a combustion-supporting air input cavity, and the other end of the shell is a combustion-supporting air output cavity. An outer ring gas ring and an inner ring gas ring are arranged on the lower tray, the outer ring gas ring and the inner ring gas ring input gas into the shell and the tail end of the shell respectively, and an adjusting cone capable of moving along the axis is arranged on the shell along the axis. Mixed gas obtained after inner ring gas and combustion-supporting air are premixed is sprayed out through the pipe and continues to be mixed with outer ring gas, backflow flue gas is entrained, uniform flue gas internal backflow is forcibly formed in the long mixing cavity, the combustion temperature is lowered, nitrogen oxide is reduced, and low-nitrogen combustion is achieved.

Description

Technical Field

[0001] The utility model relates to the field of burners, and more specifically, to a flue gas premixed staggered low-nitrogen gas burner. Background Technique

[0002] A burner is a general term for a device that makes fuel and air spray and mix (or mix and spray) in a certain way for combustion.

[0003] Conventional burners do not have a long mixing chamber, so the mixing is uneven and the nitrogen oxide emissions are unstable. Currently, through multi-layer or staged entry, only a better ratio between the combustion gas and the combustion-supporting air can be provided. However, during the combustion process, due to the influence of the high combustion temperature, part of the combustion-supporting air escapes at the spraying position and cannot be mixed well with the combustion-supporting air, resulting in poor mixing effect. The staged or layered burner structure distribution still cannot reduce the nitrogen oxide content of the combustibles, causing incomplete combustion, unstable combustion, and insufficient nitrogen oxide emissions. Content of the Utility Model

[0004] The utility model provides a flue gas premixed staggered low-nitrogen gas burner, which solves the technical problems in the related art that due to the influence of the high combustion temperature, part of the combustion-supporting air escapes at the spraying position and cannot be mixed well with the combustion-supporting air, resulting in poor mixing effect, and the staged or layered burner structure distribution still cannot reduce the nitrogen oxide content of the combustibles, causing incomplete combustion, unstable combustion, and insufficient nitrogen oxide emissions.

[0005] According to one aspect of the utility model, a flue gas premixed staggered low-nitrogen gas burner is provided, which includes a tray rack, a housing, and a mixing chamber. The housing is installed on one side of the tray rack, and the mixing chamber is installed on the other side of the tray rack. The housing is a hollow structure. The end of the housing far from the lower tray is a combustion-supporting air input chamber. An outer ring gas ring and an inner ring gas ring are provided on the lower tray. The outer ring gas ring and the inner ring gas ring respectively input gas into the housing and the end of the housing.

[0006] An adjusting cone that can move along the axis is arranged along the axis of the housing. The adjusting cone includes a cone rod, a flow dividing guide plate, an expansion part, and a cone platform push block. The flow dividing guide plate is installed on the outer wall of one end of the cone rod, the cone platform push block is installed on the other end of the cone rod, and the expansion part is arranged at the connection between the cone rod and the cone platform push block.

[0007] In the middle of the inner wall at one end of the mixing chamber close to the housing, there is a fitting seat. An elastic strip is annularly arranged on the outer side of the fitting seat. A winder is arranged at the end of the elastic strip. A through hole is provided in the hollow of the fitting seat. The inner side wall of the convex block extends into the through hole. The vertical cross-section of the through hole is an isosceles trapezoid structure. Convex blocks are annularly distributed on the outer side wall of the fitting seat. One end of the elastic strip away from the winder is connected to the convex block. When the adjusting cone moves along the axis towards the mixing chamber, the expansion part will move towards one end of the spoiler, changing the flow rate of the mixture of the outer ring gas flange and the combustion-supporting air. The frustum push block moves into the through hole and abuts against and squeezes the convex block to move towards the outside of the fitting seat. The winder can push the elastic strip to arch along;

[0008] The elastic strip changes from a strip shape distributed radially to an arc shape distributed radially. When the high-flow mixed gas enters, a swirl can be formed in the mixing chamber, enabling the high-flow gas to spiral into along the cavity wall of the mixing chamber, increasing the probability of gas mixing and collision, and making the high-flow gas mix fully.

[0009] Furthermore, one end of the flow dividing guide plate is close to the air inlet end of the housing. When the adjusting cone moves along the axis towards the mixing chamber, the expansion part will move towards one end of the spoiler, increasing the flow rate of the mixture of the outer ring gas flange and the combustion-supporting air.

[0010] Furthermore, the outer ring gas ring and the inner ring gas ring are concentrically arranged. The input end of the outer ring gas ring is connected to an outer ring gas flange. The ring end face of the outer ring gas ring is annularly distributed with outer ring gas nozzles. The pipe ends of the outer ring gas nozzles are perpendicular to the ring end face of the outer ring gas ring and extend into the outer ring gas ring.

[0011] Furthermore, the input end of the inner ring gas ring is connected to an inner ring gas flange. The inner ring side face of the inner ring gas ring is annularly distributed with inner ring gas outlet pipes. One of the pipe ends of the inner ring gas outlet pipes is perpendicular to the inner ring side face of the inner ring gas ring and extends into the inner ring gas ring. The other pipe end of the inner ring gas outlet pipe extends into the housing.

[0012] Furthermore, at one end of the housing away from the combustion-supporting air input chamber, there is a circle of spoilers arranged in a staggered manner. The outer ring gas nozzles are divided into inner layer nozzles and outer layer nozzles. The inner layer nozzles and the outer layer nozzles are attached to the outer side wall of the spoiler and are arranged in a staggered manner accordingly.

[0013] Furthermore, a flared opening is provided at one end of the mixing chamber close to the housing. The flared opening covers the output end of the housing.

[0014] Further, a combustion inner cylinder is provided at the other end of the mixing chamber. A swirler is provided inside the combustion inner cylinder, and an igniter nozzle is provided at the bottom end of the swirler. An ignition gas pipe is provided on the lower tray. One end of the ignition gas pipe is an ignition gas inlet, and the other end extends to a position near the igniter nozzle in the combustion inner cylinder. At the same time, a high-energy igniter is provided on the lower tray, and the ignition end of the high-energy igniter extends to the intersection of the igniter nozzle and the ignition gas pipe.

[0015] Further, a ring of side air inlets is provided on the outer side wall of the mixing chamber, and the side air inlets are used to obliquely introduce air into the mixing chamber.

[0016] Further, a return spring is provided between the bump and the inner side wall of the mating seat, and the return spring is used to provide a return force for the bump to return to the initial position.

[0017] Further, the tray rack includes an upper tray, a lower tray and tray connecting rods, and the connecting rods are annularly distributed between the parallel upper tray and lower tray.

[0018] The beneficial effects of the present utility model are as follows:

[0019] In this burner, the mixed gas after premixing of the inner ring gas and the combustion-supporting air is ejected through a pipe, and continues to mix with the outer ring gas and entrain and recirculate the flue gas. A uniform flue gas internal recirculation is forcibly formed in the long mixing chamber, reducing the combustion temperature, reducing the generation of nitrogen oxides, and realizing low-nitrogen combustion;

[0020] It also makes the combustion gas spiral upward along the mixing chamber wall through the deformation cooperation of the adjusting cone and the elastic strip, forming a certain included angle with the air. When burning high-calorific value combustion gas, it improves the strong rotational movement of the air flow, which is beneficial to mixing. At the same time, it changes the speed of the air flow. Cooperating with the spoiler, in the turbulent state, the diffusion of the air flow is greatly enhanced, and the mixing speed also increases. Without changing the flow rate, using a larger flow velocity can improve the mixing, increase the ratio of the flow velocities of the two air flows, which is beneficial to the improvement of mixing. According to the gas flow rate, the air flow can also be divided into many fine strands, which can increase the contact area between the combustion gas and the air, be beneficial to accelerating the mixing speed, and improving the mixing conditions of the combustion gas and the air. Description of the Drawings

[0021] Figure 1 is a schematic structural view of a flue gas premixing staggered low-nitrogen gas burner proposed by the present utility model;

[0022] Figure 2 is of the present utility model Figure 1 a schematic structural view from another perspective;

[0023] Figure 3 is of the present utility model Figure 1 front view;

[0024] Figure 4 The utility model Figure 3 Schematic diagram of the AA section structure;

[0025] Figure 5 The utility model Figure 3 Schematic diagram of the structure of the middle BB section;

[0026] Figure 6 The utility model Figure 1 Side view of

[0027] Figure 7 The utility model Figure 4 Schematic diagram of the structure of the middle adjustment cone.

[0028] In the figure: 1. shell; 2. mixing chamber; 3. combustion inner cylinder; 4. ignition gas pipe; 41. ignition gas inlet; 5. upper tray; 6. high-energy igniter; 7. outer ring gas nozzle; 71. inner layer nozzle; 72. outer layer nozzle; 8. retractor; 9. inner ring gas flange; 10. lower tray; 11. outer ring gas ring; 12. inner ring gas ring; 13. outer ring gas flange; 14. inner ring gas outlet pipe; 15. adjusting cone; 151. cone rod; 152. diverter guide plate; 153. expansion part; 154. cone push block; 16. matching seat; 17. spring bar; 18. side gas port; 19. igniter nozzle; 20. swirler; 21. bump; 22. spoiler. DETAILED DESCRIPTION

[0029] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Various examples may omit, replace, or add various processes or components as needed. In addition, the features described relative to some examples may also be combined and referenced in other examples.

[0030] Figures 1-7 As shown, a flue gas premixing staggered low nitrogen gas burner realizes efficient combustion of gas with low nitrogen oxide emission; specifically, the gas burner is divided into two parts, which are connected by a tray frame, and the two parts are a shell 1 and a mixing chamber 2. The tray frame includes an upper tray 5, a lower tray 10 and a tray connecting rod, and the connecting rod is annularly distributed between the upper tray 5 and the lower tray 10 which are arranged in parallel, wherein the shell 1 is installed on the lower tray 10, and the mixing chamber 2 is installed on the upper tray 5;

[0031] The housing 1 has a hollow structure. The end of the housing 1 away from the lower tray 10 is a combustion-supporting air input chamber. An outer-ring air ring 11 and an inner-ring air ring 12 are provided on the lower tray 10, and the outer-ring air ring 11 and the inner-ring air ring 12 are concentrically arranged. The input end of the outer-ring air ring 11 is connected to an outer-ring gas flange 13, and the input end of the inner-ring air ring 12 is connected to an inner-ring gas flange 9. The ring end face of the outer-ring air ring 11 is annularly distributed with outer-ring air nozzles 7. The pipe ends of the outer-ring air nozzles 7 are perpendicular to the ring end face of the outer-ring air ring 11 and extend into the outer-ring air ring 11. The inner-ring side of the inner-ring air ring 12 is annularly distributed with inner-ring air outlet pipes 14. One of the pipe ends of the inner-ring air outlet pipes 14 is perpendicular to the inner-ring side of the inner-ring air ring 12 and extends into the inner-ring air ring 12, and the other pipe end of the inner-ring air outlet pipes 14 extends into the housing 1;

[0032] As Figure 5 shown, a circle of staggered spoiler plates 22 is provided at the end of the housing 1 away from the combustion-supporting air input chamber. The outer-ring air nozzles 7 are divided into an inner-layer nozzle 71 and an outer-layer nozzle 72. The inner-layer nozzle 71 and the outer-layer nozzle 72 are attached to the outer side wall of the spoiler plate 22, and the inner-layer nozzle 71 and the outer-layer nozzle 72 are adaptively staggered;

[0033] An adjusting cone 15 that can move along the axis is provided in the housing 1 along the axis. The adjusting cone 15 includes a cone rod 151, a flow-dividing guide plate 152, an expansion part 153, and a cone platform push block 154. The flow-dividing guide plate 152 is installed on the outer wall of one end of the cone rod 151, the cone platform push block 154 is installed on the other end of the cone rod 151, and the expansion part 153 is provided at the connection between the cone rod 151 and the cone platform push block 154;

[0034] One end of the flow-dividing guide plate 152 is close to the air inlet end of the housing 1. When the adjusting cone 15 moves along the axis towards the mixing chamber 2, the expansion part 153 will continuously move towards one end of the spoiler plate 22, making the flow rate of the mixed gas on the side close to the spoiler plate 22 increase;

[0035] At the same time, a fitting seat 16 is provided in the middle of the inner wall at the end of the mixing chamber 2 close to the housing 1. A spring strip 17 is annularly provided outside the fitting seat 16. A winder 8 is provided at the end of the spring strip 17. A through hole is provided in the hollow of the fitting seat 16. The inner side wall of the convex block 21 extends into the through hole. The vertical cross-section of the through hole is an isosceles trapezoid structure. The outer side wall of the fitting seat 16 is annularly distributed with convex blocks 21. The end of the spring strip 17 away from the winder 8 is connected to the convex block 21. When the cone platform push block 154 moves into the through hole, it abuts and squeezes the convex block 21 to move towards the outside of the fitting seat 16. Cooperating with the winder 8, the spring strip 17 can be pushed to arch along, forming as Figure 5As shown, the spring strip 17 is strip-shaped and distributed radially, and becomes arc-shaped and distributed radially. When the mixed gas with a relatively high flow rate enters, a swirling flow can be formed in the mixing chamber 2, so that the gas with a high flow rate spirally enters along the chamber wall of the mixing chamber 2, increasing the probability of gas mixing and collision, and making the high-flow gas mix fully;

[0036] When the flow rate is relatively small, that is, the expansion part 153 moves away from one end of the spoiler, the gas output through the spoiler plate 22 has a relatively low flow rate but a large flow rate, and is separated by the reset strip-shaped spring strip 17, increasing the contact area between the combustion gas and the air, and then entering one end of the swirler 20 for mixing, and being ignited by the ignition end to achieve full combustion;

[0037] It should be added that a return spring is provided between the inner side wall of the convex block 21 and the mating seat 16, and the return spring is used to provide a return force for the convex block 21 to return to the initial position;

[0038] A flared opening is provided at one end of the mixing chamber 2 close to the housing 1, and the flared opening covers the output end of the housing 1. A combustion inner cylinder 3 is provided at the other end of the mixing chamber 2. A swirler 20 is provided inside the combustion inner cylinder 3. An igniter nozzle 19 is provided at the bottom end of the swirler 20. An ignition gas pipe 4 is provided on the lower tray 10. One end of the ignition gas pipe 4 is an ignition gas inlet 41, and the other end extends to a position close to the igniter nozzle 19 in the combustion inner cylinder 3, that is, the ignition gas spray port. At the same time, a high-energy igniter 6 is provided on the lower tray 10, and the ignition end of the high-energy igniter 6 extends to the intersection of the igniter nozzle 19 and the ignition gas pipe 4;

[0039] It should be added that a circle of side air inlets 18 is provided on the outer side wall of the mixing chamber 2, and the side air inlets 18 are used to obliquely introduce air into the mixing chamber 2;

[0040] It should be added that a driving motor is provided inside the winder 8, the output shaft of the driving motor is connected to a winding shaft, one end of the spring strip 17 is connected to the winding shaft. When the driving motor rotates, the winding shaft can be driven to rotate, releasing some of the wound spring strip 17, and forming an arched structure under the extrusion of the convex block 21;

[0041] The winder 8 is a prior art, mainly used to cooperate with the convex block 21 to abut and deform the spring strip 17, so its working principle will not be elaborated here;

[0042] It should be added that small spray ports are opened on the pipe wall of the inner ring gas outlet pipe 14, and the inner ring gas is sprayed out through the small spray ports and mixed into the housing 1;

[0043] The working process of this gas burner is as follows:

[0044] Among them, the combustion-supporting air is input from one end of the front end of the housing 1 close to the adjusting cone 15. The inner-ring gas enters the inner-ring gas ring 12 from the inner-ring gas flange 9, enters the inner-ring gas outlet pipe 14 through the inner-ring gas ring 12. There are multiple small nozzles on the inner-ring gas outlet pipe 14, and the inner-ring gas is ejected from the small nozzles and mixed with the combustion-supporting air in the housing 1;

[0045] The mixed gas after the inner-ring gas is mixed with the combustion-supporting air is ejected from the outlet at the front end of the housing 1. A flared mouth is provided at the front part of the housing 1 to accelerate the flow rate of the mixed gas, and a negative pressure area is formed on one side close to the spoiler 22 to attract the flue gas to flow back. As shown in Figure 5, there is a spoiler 22 at the outlet at the front end of the housing 1, which further accelerates the gas mixing. An adjusting cone 15 is provided at the center of the housing 1. The adjusting cone 15 can be adjusted back and forth to change the flow rate distribution of the mixed gas at the outlet of the housing 1, so as to change the flue gas return flow rate;

[0046] Among them, when the adjusting cone 15 moves axially, the frustum push block 154 moves and inserts into the through hole, and the abutting and extruding convex block 21 moves toward the outside of the mating seat 16, that is, the convex block 21 expands radially outward. The coiling device 8 can push the elastic strip 17 to arch along, forming as Figure 5 shown in. The elastic strip 17 is strip-shaped and distributed radially, and becomes arc-shaped and distributed radially. When the mixed gas with a relatively high flow rate enters, a swirl can be formed in the mixing chamber 2, and then the high-flow-rate gas spirally enters along the cavity wall of the mixing chamber 2, increasing the probability of gas mixing and collision, and making the high-flow-rate gas mix fully;

[0047] When the expansion part 153 of the adjusting cone 15 is far from the side of the spoiler 22, the elastic plate is strip-shaped and is used to separate the mixed gas entering the mixing chamber 2, so as to divide the air flow into several thin strands, or adopt a flat flow strand, improve the remixing of the mixed gas and the air entering from the side air port 18, increase the proportion of combustion-supporting air in the mixed gas, and improve the combustion efficiency;

[0048] The outer-ring gas enters the outer-ring gas ring 11 from the outer-ring gas flange 13, enters the outer-ring gas nozzle 7 through the outer-ring gas ring 11 and is ejected. The outer-ring gas nozzles 7 are arranged in a circumferential staggered layer at the nozzle of the housing 1 to facilitate the mixing of the outer-ring gas and the mixed gas ejected from the housing 1. The mixed gas, the outer-ring gas return flue gas, enter the mixing chamber 2 together and flow out from the front end of the mixing chamber 2 for stable combustion;

[0049] A combustion inner cylinder 3 is provided at the front end of the mixing chamber 2. There is a swirler 20 at the front end of the combustion inner cylinder 3. The ignition gas enters the ignition gas pipe 4 from the ignition gas inlet 41, is ejected from the ignition gas nozzle through the ignition gas ejector, and is ignited by the high-energy igniter 6, thus realizing ignition.

[0050] The above has described the embodiments of this example, but this example is not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative rather than restrictive. Under the inspiration of this example, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of this example.

Claims

1. A flue gas premixed staggered low nitrogen gas burner, characterized in that: The invention comprises a tray frame, a shell (1) and a mixing chamber (2), wherein the shell (1) is mounted on one side of the tray frame, and the mixing chamber (2) is mounted on the other side of the tray frame, the shell (1) is a hollow structure, and one end of the shell (1) away from the lower tray (10) is a combustion air input chamber, and an outer ring gas ring (11) and an inner ring gas ring (12) are provided on the lower tray (10), and the outer ring gas ring (11) and the inner ring gas ring (12) respectively input fuel gas into the shell (1) and the end of the shell (1); An adjusting cone (15) is arranged on the housing (1) along the axis and can move along the axis. The adjusting cone (15) comprises a cone rod (151), a flow dividing guide plate (152), an expansion portion (153) and a cone push block (154). The flow dividing guide plate (152) is mounted on the outer wall of one end of the cone rod (151), the cone push block (154) is mounted on the other end of the cone rod (151), and the expansion portion (153) is arranged at the connection between the cone rod (151) and the cone push block (154). A matching seat (16) is provided in the middle of the inner wall of one end of the mixing chamber (2) close to the shell (1), a spring bar (17) is provided in an annular shape on the outer side of the matching seat (16), a reel (8) is provided at the end of the spring bar (17), a through hole is provided in the hollow of the matching seat (16), wherein the inner side wall of the protrusion (21) extends into the through hole, the vertical section of the through hole is an isosceles trapezoidal structure, the outer side wall of the matching seat (16) is provided with protrusions (21) in an annular shape, and the spring bar (17) is away from the reel. One end of the adjusting cone (15) is connected to the protrusion (21). When the adjusting cone (15) moves along the axis toward the mixing chamber (2), the expansion portion (153) moves toward one end of the spoiler (22), so that the flow rate of the outer ring gas flange (13) and the combustion air after mixing changes. The cone push block (154) moves into the through hole, abuts against the extrusion protrusion (21) and moves toward the outside of the matching seat (16). The matching reel (8) can push the elastic strip (17) to arch along. The elastic strips (17) are changed from being strip-shaped and distributed radially to being arc-shaped and distributed radially. When a mixed gas with a relatively high flow rate enters, a swirl flow can be formed in the mixing chamber (2), so that the high-flow-rate gas enters in a spiral along the wall of the mixing chamber (2), thereby increasing the probability of gas mixing and collision, and allowing the high-flow-rate gas to be fully mixed.

2. The flue gas premixing staggered low nitrogen gas burner according to claim 1 is characterized in that: One end of the flow dividing guide plate (152) is close to the air inlet end of the shell (1). When the regulating cone (15) moves along the axis toward the mixing chamber (2), the expansion portion (153) moves toward one end of the spoiler (22), thereby increasing the flow rate of the outer ring gas flange (13) and the combustion-supporting air after mixing.

3. The flue gas premixing staggered low nitrogen gas burner according to claim 2 is characterized in that: The outer ring gas ring (11) and the inner ring gas ring (12) are arranged concentrically, and the input end of the outer ring gas ring (11) is connected to the outer ring gas flange (13), wherein the ring end surface of the outer ring gas ring (11) is annularly distributed with an outer ring gas nozzle (7), and the pipe end of the outer ring gas nozzle (7) is perpendicular to the ring end surface of the outer ring gas ring (11) and extends to the inside of the outer ring gas ring (11).

4. The flue gas premixing staggered low nitrogen gas burner according to claim 3 is characterized in that: The input end of the inner ring gas ring (12) is connected to an inner ring gas flange (9), and an inner ring gas outlet pipe (14) is distributed in an annular manner on the inner ring side surface of the inner ring gas ring (12), one pipe end of the inner ring gas outlet pipe (14) is perpendicular to the inner ring side surface of the inner ring gas ring (12) and extends into the inner ring gas ring (12), and the other pipe end of the inner ring gas outlet pipe (14) extends into the shell (1).

5. The flue gas premixing staggered low nitrogen gas burner according to claim 4 is characterized in that: A circle of staggered spoilers (22) is provided at one end of the shell (1) away from the combustion air input chamber, and the outer ring air nozzle (7) is divided into an inner layer nozzle (71) and an outer layer nozzle (72). The inner layer nozzle (71) and the outer layer nozzle (72) are attached to the outer side wall of the spoiler (22), and the inner layer nozzle (71) and the outer layer nozzle (72) are staggered in an adaptive manner.

6. The flue gas premixing staggered low nitrogen gas burner according to claim 5, characterized in that: A bell mouth is provided at one end of the mixing chamber (2) close to the shell (1), and the bell mouth cover is provided on the output end of the shell (1).

7. The flue gas premixing staggered low nitrogen gas burner according to claim 6, characterized in that: A combustion inner cylinder (3) is provided at the other end of the mixing chamber (2), a swirler (20) is provided inside the combustion inner cylinder (3), an igniter nozzle (19) is provided at the bottom end of the swirler (20), an ignition gas pipe (4) is provided on the lower tray (10), one end of the ignition gas pipe (4) is an ignition gas inlet (41), and the other end extends to the combustion inner cylinder (3) near the igniter nozzle (19), and a high-energy igniter (6) is provided on the lower tray (10), and the ignition end of the high-energy igniter (6) extends to the intersection of the igniter nozzle (19) and the ignition gas pipe (4).

8. The flue gas premixing staggered low nitrogen gas burner according to claim 7 is characterized in that: A circle of side air ports (18) is provided on the outer side wall of the mixing chamber (2), and the side air ports (18) are used to obliquely introduce air into the mixing chamber (2).

9. The flue gas premixing staggered low nitrogen gas burner according to claim 8, characterized in that: A return spring is provided between the projection (21) and the inner side wall of the matching seat (16), and the return spring is used to provide a return force for returning the projection (21) to an initial position.

10. The flue gas premixing staggered low nitrogen gas burner according to claim 9, characterized in that: The tray rack comprises an upper tray (5), a lower tray (10) and tray connecting rods, wherein the connecting rods are annularly distributed between the upper tray (5) and the lower tray (10) which are arranged in parallel.

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