A low-NOx gas burner

Abstract

This utility model discloses a low-NOx gas burner, including a burner shell and a burner head disposed at the front end of the burner shell. One end of the burner head has an air inlet, and a premixer is disposed inside the burner head. The premixer includes a first sleeve and a second sleeve arranged coaxially in a ring, forming a premixing chamber. Several swirl blades are evenly distributed along the center of the outer side of the first sleeve near the air inlet. This utility model avoids gas diffusion and leakage during premixing by placing the premixer inside the burner head. Furthermore, the premixing chambers one and two of the premixer perform dual premixing of the gas and combustion air. The swirl blades one and two are arranged in opposite directions, causing bidirectional rotation and agitation between the combustion air and the gas, resulting in more uniform premixing and more complete combustion, thereby reducing the content of nitrogen oxides.

Description

Technical Field

[0001] This utility model relates to the field of gas burner technology, specifically to a low-NOx gas burner. Background Technology

[0002] With the advancement of technology, the types of burners used in daily life and work are increasing, and their applications are becoming more widespread. Gas burners are divided into natural gas burners, city gas burners, etc. According to the combustion control method, they are classified as single-stage burners, dual-stage burners, and proportional control burners. According to the fuel atomization method, they are classified as mechanical atomizing burners and medium atomizing burners. In a broad sense, household water heaters, gas stoves, and even lighters can all be considered as a type of burner.

[0003] The premixer in existing gas burners is usually located at the front end of the burner head, which makes it easy for the gas to diffuse and leak from the front end of the burner head during premixing. In addition, existing gas burners do not have a good premixing effect between gas and combustion air, resulting in incomplete combustion and thus producing more nitrogen oxides.

[0004] Therefore, the applicant has made beneficial designs and found a way to solve the above problems. The technical solution to be introduced below is generated in this context. Utility Model Content

[0005] The present invention provides a low-NOx gas burner to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A low-NOx gas burner includes a burner housing and a burner head disposed at the front end of the burner housing. One end of the burner head has an air inlet. A premixer is disposed inside the burner head. The premixer includes a first sleeve and a second sleeve arranged coaxially in a ring, forming a premixing chamber. A plurality of swirl blades are evenly distributed along the center of the outer side of the first sleeve near the air inlet. The second premixing chamber is disposed inside the first sleeve. A plurality of swirl blades are evenly distributed along the center of the outer side of the second sleeve near the air inlet. A plurality of swirl blades are evenly distributed around the center of the sleeve. A plurality of air outlets are evenly distributed around the center of the sleeve. A plurality of air outlets are evenly distributed around the center of the sleeve. The premixing chamber is connected to the premixing chamber through the air outlets. An air inlet is provided at the bottom of the sleeve. A plurality of swirl blades are inclined in the same direction around the center of the sleeve. A plurality of swirl blades are inclined in the same direction around the center of the sleeve. The inclination angles of the plurality of swirl blades are opposite to those of the plurality of swirl blades.

[0008] Preferably, the burner housing has an air supply chamber inside, and the air inlet is connected to the air supply chamber.

[0009] Preferably, the air supply chamber is equipped with a fan wheel, and a motor is provided on one side of the air supply chamber, with the fan wheel connected to the output shaft of the motor.

[0010] Preferably, the burner housing has an air inlet chamber at the bottom front end, which is connected to the air supply chamber, and a filter plate is detachably provided at the front end of the air inlet chamber.

[0011] Preferably, a flame arrester is provided at the end of the burner head away from the air inlet, a flame stabilizing plate is provided at the front end of the flame arrester, and an igniter is provided at the front end of the flame stabilizing plate.

[0012] Preferably, the flame stabilizing disk has a plurality of flame passage holes on its surface, and the plurality of flame passage holes are arranged in a dense or sparse manner along the center of the flame stabilizing disk.

[0013] Preferably, the bottom of the vent pipe is provided with a gas interface, and the air inlet is connected to the gas interface. Beneficial effects

[0014] The low-NOx gas burner provided in this embodiment of the utility model has at least one of the following technical effects:

[0015] This invention, through the above-mentioned technical solution, avoids gas diffusion and leakage during premixing by placing the premixer inside the burner head. Furthermore, the premixer's first and second premixing chambers perform dual premixing of the gas and combustion air, resulting in better premixing effect. Moreover, by arranging the first and second swirl blades in opposite directions, the combustion air and gas are bidirectionally rotated and stirred, making the premixing more uniform and enabling more complete combustion during combustion, thereby reducing the content of nitrogen oxides. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0018] Figure 3 This is a schematic diagram of the internal structure of the burner housing of this utility model;

[0019] Figure 4 This is a schematic diagram of the premixer structure of this utility model;

[0020] Figure 5 This is a cross-sectional structural diagram of the premixer of this utility model.

[0021] The correspondence between the labels and component names in the attached figures is as follows:

[0022] 1. Burner shell; 2. Burner head; 3. Air inlet; 4. Premixer; 5. Sleeve 1; 6. Sleeve 2; 7. Premixing chamber 1; 8. Swirl blade 1; 9. Premixing chamber 2; 10. Swirl blade 2; 11. Outlet 1; 12. Outlet 2; 13. Air inlet; 14. Air supply chamber; 15. Fan impeller; 16. Motor; 17. Air supply chamber; 18. Filter plate; 19. Flame arrester; 20. Flame stabilizer; 21. Ignition device; 22. Flame vent; 23. Gas interface. Detailed Implementation

[0023] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] To avoid excessive and unnecessary details, well-known structures or functions will not be described in detail in the following embodiments.

[0027] like Figure 1-5 The diagram shown is a structural schematic of a low-NOx gas burner according to a preferred embodiment of the present invention.

[0028] In this embodiment, a burner housing 1 and a burner head 2 located at the front end of the burner housing 1 are included. One end of the burner head 2 has an air inlet 3 for receiving combustion air. A premixer 4 is located inside the burner head 2 for mixing the combustion air and fuel gas. The premixer 4 includes a first sleeve 5 and a second sleeve 6 arranged coaxially in a ring. Both sleeves 5 and 6 are cylindrical structures. A premixing chamber 7 is formed between the first sleeve 5 and the second sleeve 6. The premixing chamber 7 is used for the first premixing of the fuel gas and combustion air. Several swirl vanes 8 are evenly distributed along the center of the outer side of the first sleeve 5 near the air inlet 3. When the combustion air passes through the swirl vanes 8, it is... 8. The combustion air is rotated and guided, causing the combustion air to rotate and mix with the gas. A premixing chamber 9 is provided inside the sleeve 5, which is used for a second premixing of the gas and combustion air. Several swirl vanes 10 are evenly distributed along the center of the inner side of the sleeve 6 near the air inlet 3. When the combustion air passes through the swirl vanes 8, the swirl vanes 8 rotate and guide the combustion air, causing the combustion air to rotate and mix with the gas. Several air outlets 11 and 12 are evenly distributed along the center of the surface of the sleeve 5 and the sleeve 6, respectively. The premixing chamber 9 is connected to the premixing chamber 7 through the air outlets 12. The bottom of the sleeve 5 is provided with... The device has an air inlet 13. Several swirl vanes 8 are inclined in the same direction along the center of sleeve 5, and several swirl vanes 10 are inclined in the same direction along the center of sleeve 6. The inclination angles of the swirl vanes 8 and 10 are opposite. In use, combustion air enters the burner head through the air inlet 3. As the combustion air passes through the swirl vanes 8 and 10, their inclination angles guide the air, causing it to rotate and agitate the combustion gas, thus completing the mixing. Because the inclination angles of the swirl vanes 8 and 10 are opposite, the combustion gas in premixing chamber 7 and premixing chamber 9 are mixed. The combustion air is rotated and stirred in opposite directions, resulting in more intense stirring and more uniform and thorough mixing. The premixed gas and combustion air are discharged to the front end of the burner head 2 through the end of the premixing chamber 2 9 away from the swirl blade 2 10 and the outlet 11. By placing the premixer 4 inside the burner head 2, gas diffusion and leakage during premixing are avoided. The premixing chamber 1 7 and the premixing chamber 2 9 of the premixer 4 perform double premixing of the gas and combustion air, resulting in better premixing effect. Furthermore, by setting the swirl blade 1 8 and the swirl blade 2 10 in opposite directions, the combustion air and gas rotate and stir in both directions, resulting in more uniform premixing and more complete combustion during combustion, thereby reducing the content of nitrogen oxides.

[0029] In this embodiment, the burner housing 1 is provided with an air supply chamber 14 inside, and the air inlet 3 is connected to the air supply chamber 14. This structure realizes the communication effect between the burner housing 1 and the burner head 2, so that the combustion air can smoothly enter the burner head 2.

[0030] In this embodiment, a fan wheel 15 is provided inside the air supply chamber 14, and a motor 16 is provided on one side of the air supply chamber 14. The fan wheel 15 is connected to the output shaft of the motor 16. The motor 16 drives the fan wheel 15 to rotate, and sends the air (combustion air) in the air supply chamber 14 to the air inlet 3 of the burner head 2 (this structure is a conventional method in the prior art, so it will not be described in detail).

[0031] In this embodiment, an air inlet chamber 17 is provided at the bottom front end of the burner housing 1. The air inlet chamber 17 is connected to the air supply chamber 14. Outside air enters the air supply chamber 14 through the air inlet chamber 17. A filter plate 18 is detachably provided at the front end of the air inlet chamber 17. The filter plate 18 is used to filter the air and prevent dust and water molecules in the air from entering the air inlet chamber 17 (this structure is a conventional method in the prior art, so it will not be described in detail).

[0032] In this embodiment, a flame arrester 19 is provided at the end of the burner head 2 opposite to the air inlet 3. A flame stabilizing disc 20 is provided at the front end of the flame arrester 19, and an igniter 21 is provided at the front end of the flame stabilizing disc 20. The flame stabilizing disc 20 is mainly used to stabilize the flame, optimize combustion efficiency, and control the flame shape. High-speed airflow may extinguish the flame (flame detachment) or cause the flame to backfire into the burner (backfire). The flame stabilizing disc 20 reduces the local airflow velocity through physical structures (such as vent holes and swirl vanes), forming a low-speed backflow zone, so that the flame root is always anchored near the disc surface. The vortex zone behind the flame stabilizing disc 20 can retain high-temperature combustion products, continuously ignite fresh mixture, and maintain flame stability. The igniter 21 is mainly used for ignition (this structure is a conventional method in the prior art, so it will not be described in detail).

[0033] In this embodiment, the flame stabilizing disk 20 has a plurality of flame holes 22 on its surface. The plurality of flame holes 22 are arranged in a dense or sparse manner along the center of the flame stabilizing disk 20. When the flame holes 22 are densely arranged, the flame jet is long and thin. When the flame holes 22 are sparsely arranged, the flame jet is short and thick. (Principle: 1. Dense flame holes: Dense flame holes will divide the airflow into more small streams, each with a smaller cross-sectional area. According to the law of conservation of mass (Q=A⋅v), when the total flow rate is constant, the reduction of the area of ​​a single hole will lead to an increase in the airflow velocity (vv). High-speed airflow can penetrate a greater distance, forming a longer flame. Dense small holes increase the contact area between the airflow and the surrounding air (enhanced turbulent mixing), and the fuel and air are mixed more thoroughly. The combustion reaction speed of a thoroughly mixed airflow is faster, but the flame length is extended due to the inertia of the high-speed airflow, forming a slender flame shape. There is less interference between multiple small flames, and the flames are not easy to merge, exhibiting a uniform and slender characteristic. 2.) Sparse flame orifice configuration: Sparse flame orifices result in a larger individual orifice area and a lower exhaust velocity (vv). The low-velocity airflow is easily slowed by surrounding air resistance, making it difficult for the flame to extend and resulting in a shorter flame. The large-aperture airflow has lower mixing efficiency with air (weaker turbulence), and the combustion reaction is concentrated near the nozzle, resulting in a thicker flame front. Incompletely mixed fuel may burn on the periphery of the flame, forming a diffuse flame characteristic (thick and short). Sparse flames are more likely to attract and merge after ejection, forming a larger flame cluster, further exacerbating the thick and short flame shape.

[0034] In this embodiment, the burner head 2 is provided with a gas interface 23 at the bottom. The air inlet 13 is connected to the gas interface 23. The gas interface 23 is used to connect to the gas pipeline. The gas enters the air inlet 13 through the gas interface 23 and enters the premixing chamber 7 through the air inlet 13 for the first premixing.

[0035] The low-NOx gas burner of this utility model can be installed, connected, or set in a common mechanical manner, and can be implemented as long as it can achieve its beneficial effects.

[0036] All technologies not described in detail in this utility model are known technologies. Those skilled in the art can easily implement this utility model based on their understanding of this specification, and the contents shown in the accompanying drawings are part of this specification.

[0037] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present utility model. It should not be construed that the specific implementation of the present utility model is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present utility model, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted by the present utility model.

Claims

1. A low-NOx gas burner, comprising a burner housing (1) and a burner head (2) disposed at the front end of the burner housing (1), characterized in that: The burner head (2) has an air inlet (3) at one end, and a premixer (4) is provided inside the burner head (2). The premixer (4) includes a sleeve 1 (5) and a sleeve 2 (6) arranged in a coaxial ring. A premixing chamber 1 (7) is formed between the sleeve 1 (5) and the sleeve 2 (6). Several swirl blades 1 (8) are evenly distributed along the center of the outer side of the sleeve 1 (5) near the air inlet (3). A premixing chamber 2 (9) is provided inside the sleeve 1 (5). Several swirl blades 2 (10) are evenly distributed along the center of the inner side of the sleeve 2 (6) near the air inlet (3). The surface of sleeve one (5) is evenly distributed with several air outlet holes one (11) along the center. The surface of sleeve two (6) is evenly distributed with several air outlet holes two (12) along the center. The premixing chamber two (9) is connected to the premixing chamber one (7) through the air outlet holes two (12). The bottom of sleeve one (5) is provided with an air inlet (13). Several swirl blades one (8) are inclined in the same direction along the center of sleeve one (5). Several swirl blades two (10) are inclined in the same direction along the center of sleeve two (6). The inclination angles between several swirl blades one (8) and several swirl blades two (10) are opposite.

2. The low-NOx gas burner according to claim 1, characterized in that: The burner housing (1) has an air supply chamber (14) inside, and the air inlet (3) is connected to the air supply chamber (14).

3. A low-NOx gas burner according to claim 2, characterized in that: The air supply chamber (14) is equipped with a fan wheel (15), and a motor (16) is provided on one side of the air supply chamber (14). The fan wheel (15) is connected to the output shaft of the motor (16).

4. A low-NOx gas burner according to claim 2, characterized in that: The burner housing (1) has an air inlet chamber (17) at the bottom of its front end. The air inlet chamber (17) is connected to the air supply chamber (14). The front end of the air inlet chamber (17) is detachably equipped with a filter plate (18).

5. A low-NOx gas burner according to claim 1, characterized in that: The burner head (2) is provided with a flame arrester (19) at the end away from the air inlet (3), and a flame stabilizer (20) is provided at the front end of the flame arrester (19), and an igniter (21) is provided at the front end of the flame stabilizer (20).

6. A low-NOx gas burner according to claim 5, characterized in that: The flame stabilizer (20) has a number of flame holes (22) on its surface, and the number of flame holes (22) are arranged in a dense or sparse manner along the center of the flame stabilizer (20).

7. A low-NOx gas burner according to claim 1, characterized in that: The burner head (2) is provided with a gas interface (23) at the bottom, and the air inlet (13) is connected to the gas interface (23).

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