A low-nitrogen burner based on flue gas internal circulation

Abstract

The present invention relates to the technical field of burners, and discloses a low-nitrogen burner based on flue gas internal circulation, including a burner housing. At the center position of the burner housing, a connection sleeve is fixedly spliced in an embedded manner. At the center position of the connection sleeve, an internal sleeve is fixedly spliced. On the front side of the burner housing, a plurality of air pipe connection ports communicating with the air outer cavity are penetrated in an annular array. On the front side of the connection sleeve, a plurality of gas pipe connection ports communicating with the gas inner cavity are penetrated in an annular array. Spiral threads are provided on the inner wall surfaces of the air pipe connection ports and the gas pipe connection ports. A plurality of support plates are fixedly installed at equal intervals on the inner wall surface of the internal sleeve. In the present invention, the air and gas in the internal sleeve are well mixed and then burned, further improving the combustion efficiency. At the same time, the central temperature in the burner is reduced, achieving the effect of reducing the generation of thermal nitrogen oxides.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and particularly to a low-nitrogen burner based on flue gas internal circulation. Background Art

[0002] Industrial boilers provide kinetic energy for the production of industries such as textile, printing and dyeing, pharmaceutical, chemical, and oil refining; compared with coal and petroleum, natural gas is the cleanest among the three major petrochemical energy sources; natural gas has gradually changed from an alternative energy source to a main energy source, and natural gas burners have many advantages compared with oil-fired and coal-fired burners, such as stable combustion flame, high combustion thermal efficiency, low noise, relatively less harmful gases and soot, etc.

[0003] There are many current low-nitrogen combustion technologies, including fuel staging and air staging combustion technologies, low excess air coefficient combustion, catalytic combustion, flameless combustion, flue gas recirculation technology combustion, which are divided into flue gas external circulation and flue gas internal circulation technology combustion. When the existing natural gas burners are in use, the central flame is concentrated, making the central temperature inside the burner the highest, and it cannot disperse the central flame to reduce the central combustion temperature to achieve the effect of reducing the generation of thermal nitrogen oxides.

[0004] For this reason, we propose a low-nitrogen burner based on flue gas internal circulation. Summary of the Invention

[0005] The present invention mainly solves the technical problems existing in the above-mentioned prior art, and provides a low-nitrogen burner based on flue gas internal circulation.

[0006] To achieve the above object, the present invention adopts the following technical solution. A low-nitrogen burner based on flue gas internal circulation includes a burner housing. At the center position of the burner housing, a connection sleeve is fixedly spliced in an embedded manner. At the center position of the connection sleeve, an inner sleeve is fixedly spliced. On the front side of the burner housing, a plurality of air pipe connection ports communicating with the air outer cavity are formed in a circular array. On the front side of the connection sleeve, a plurality of gas pipe connection ports communicating with the gas inner cavity are formed in a circular array. The inner wall surfaces of the air pipe connection ports and the gas pipe connection ports are both provided with spiral threads. A plurality of support plates are equidistantly and fixedly installed on the inner wall surface of the inner sleeve. A flame plate is fixedly installed inside the inner sleeve through a plurality of support plates. A plurality of swirl vanes are arranged at the outer circle of the flame plate;

[0007] A plurality of air pipes are threadedly installed on the burner housing through a plurality of air pipe connection ports. The air pipes include injection pipes, mixing pipes and threaded sections. The injection pipes are sleeved and installed inside the mixing pipes;

[0008] A plurality of gas pipes are threadedly installed on the connection sleeve through a plurality of gas pipe connection ports. The structure of the gas pipes is the same as that of the air pipes.

[0009] Preferably, a cavity is formed between the outer wall surface of the connecting sleeve inside the burner housing and the inner wall surface of the burner housing, and the cavity formed between the burner housing and the connecting sleeve is an outer air cavity.

[0010] Preferably, the inner space of the connecting sleeve inside the burner housing is a gas inner cavity.

[0011] Preferably, the flame disk is coaxially arranged inside the built-in sleeve, a central gas pipe is fixedly sleeved at the center position of the flame disk, a central nozzle is fixedly installed inside the central gas pipe located inside the flame disk, and a plurality of groups of gas small holes are opened on the central nozzle, and the plurality of groups of gas small holes are evenly distributed on the central nozzle.

[0012] Preferably, a plurality of groups of sliding grooves are equidistantly opened at the outer circle of the flame disk, a rotating connecting leg and a sliding connecting leg are respectively fixedly installed on the swirl vane, the rotating connecting leg drives the swirl vane to be rotatably installed at the outer circle of the flame disk, and the sliding connecting leg drives the swirl vane to be slidably installed at the outer circle of the flame disk through the sliding groove.

[0013] Preferably, a heat insulation ring made of heat insulation material is threadedly installed at the outer circle of the flame disk, and a small connecting column is fixedly installed at the position of the outer side surface of the swirl vane close to the sliding connecting leg, and the swirl vane is fixedly connected to the heat insulation ring through the small connecting column.

[0014] Preferably, a plurality of groups of air holes are penetrated through the flame disk.

[0015] Preferably, a threaded section is provided on the outer surface of the outer circle of the injection pipe on the side far from the mixing pipe.

[0016] Preferably, a plurality of groups of elastic inner expansion strips are fixedly installed at the end position of the injection pipe close to the mixing pipe, and the inner expansion strips are distributed in an expanded state away from the injection pipe at one end of the injection pipe far from the threaded section.

[0017] Preferably, a plurality of groups of elastic outer fastening strips are fixedly installed at the end position of one end of the mixing pipe, and the plurality of groups of outer fastening strips are distributed in a contracted state away from the mixing pipe.

[0018] Beneficial effects

[0019] The present invention provides a low-nitrogen burner based on flue gas internal circulation. It has the following beneficial effects:

[0020] (1) This low-nitrogen burner based on flue gas internal circulation delivers gas to the inside of the furnace through two paths. Most of the gas is transported through multiple gas pipes, passes through the gas chamber, and then reaches the furnace. A small part of the gas is transported through the central gas pipe and sent into the furnace. Air also reaches the furnace through two paths. A part of the air is transported through multiple air pipes, passes through the outer air chamber, and then enters the furnace. Another part of the air enters the furnace through the gaps between multiple swirl vanes and the flame disk. By delivering both gas and air to the furnace through two paths, the gas and air that reach the gas inner chamber and the outer air chamber respectively are fully mixed before reaching the furnace, achieving the effect of improving the combustion efficiency of the burner.

[0021] (2) This low-nitrogen burner based on flue gas internal circulation effectively disperses the central air through the multiple sets of swirl vanes installed, reducing the gas flow rate of the direct-flow burner head, enabling the air and gas in the built-in sleeve to be well mixed and burned, further improving the combustion efficiency, and at the same time achieving the effect of reducing the central temperature inside the burner and reducing the generation of thermal-type nitrogen oxides.

[0022] (3) This low-nitrogen burner based on flue gas internal circulation rotates the heat insulation ring, causing the heat insulation ring to move back and forth on the flame disk. During the back-and-forth movement of the heat insulation ring, it drives the swirl vanes to move through the small connecting columns, enabling the swirl vanes to move back and forth in the chute through the sliding connecting legs on the side away from the rotating connecting legs. By rotating the heat insulation ring to drive the swirl vanes to flip, the angle between the swirl vanes and the flame disk is adjusted. When the angle between the multiple sets of swirl vanes and the flame disk is larger, the gap between the swirl vanes and the flame disk is larger. The gap formed between the swirl vanes and the flame disk plays the role of air swirl. Through such a setting, the effect of freely adjusting the distribution angle of the swirl vanes is achieved, improving the practicality of the device.

[0023] (4) This low-nitrogen burner based on flue gas internal circulation transports most of the gas through multiple gas pipes, passes through the gas inner chamber, and then reaches the furnace. A small part of the gas is transported through the central gas pipe and sent into the furnace. A small part of the gas is input into the furnace from the central gas pipe, achieving the effects of facilitating ignition and stabilizing the flame.

[0024] (5) When the injection pipe is sleeved and installed inside the mixing pipe, the injection pipe expands through multiple inner expansion strips and squeezes the inner wall surface of the mixing pipe, thereby fixing the injection pipe to be sleeved inside the mixing pipe. When the injection pipe is sleeved and installed inside the mixing pipe, the mixing pipe contracts through multiple outer fastening strips and squeezes the outer wall surface of the injection pipe, further firmly sleeving the injection pipe inside the mixing pipe. The injection pipe and the mixing pipe are firmly connected and installed together through the mutual cooperation of multiple inner expansion strips and outer fastening strips, achieving the effect of firmly connecting the injection pipe and the mixing pipe. Description of the Drawings

[0025] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0026] The structures, proportions, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0027] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention;

[0028] Figure 2 It is a split schematic diagram of the position structure of the swirl vane of the present invention;

[0029] Figure 3 It is a three-dimensional structure schematic diagram of the swirl vane and the flame disc of the present invention;

[0030] Figure 4 It is a three-dimensional structure schematic diagram of the air pipe of the present invention;

[0031] Figure 5 It is a split three-dimensional structure schematic diagram of the air pipe of the present invention.

[0032] Legend Explanation:

[0033] 1. Burner housing; 2. Connecting sleeve; 3. Air pipe connection port; 4. Gas pipe connection port; 5. Built-in sleeve; 6. Central gas pipe; 7. Flame disc; 8. Support plate; 9. Swirl vane; 10. Chute; 11. Rotating connecting leg; 12. Sliding connecting leg; 13. Heat insulation ring; 14. Air pipe; 15. Injection pipe; 16. Mixing pipe; 17. Threaded section; 18. Inner expansion strip; 19. Outer fastening strip; 20. Small connecting column; 21. Air hole. Specific Embodiments

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] Embodiment: A low-nitrogen burner based on flue gas internal circulation, as Figures 1 - 5 shown, includes a burner housing 1. At the center position of the burner housing 1, a connecting sleeve 2 is fixedly spliced in an embedded manner. At the center position of the connecting sleeve 2, an inner sleeve 5 is fixedly spliced. A cavity is formed between the outer wall surface of the connecting sleeve 2 inside the burner housing 1 and the inner wall surface of the burner housing 1. The cavity formed between the burner housing 1 and the connecting sleeve 2 is an outer air cavity. The inner space of the connecting sleeve 2 inside the burner housing 1 is a gas inner cavity. On the front side of the burner housing 1, a plurality of air pipe connection ports 3 communicating with the outer air cavity are arranged in a circular array. On the front side of the connecting sleeve 2, a plurality of gas pipe connection ports 4 communicating with the gas inner cavity are arranged in a circular array. Threads are provided on the inner wall surfaces of the air pipe connection ports 3 and the gas pipe connection ports 4. A plurality of support plates 8 are fixedly installed at equal intervals on the inner wall surface of the inner sleeve 5. A flame plate 7 is fixedly installed inside the inner sleeve 5 through the plurality of support plates 8. The flame plate 7 is coaxially arranged inside the inner sleeve 5. A central gas pipe 6 is fixedly sleeved at the center position of the flame plate 7. A central nozzle is fixedly installed inside the central gas pipe 6 inside the flame plate 7. A plurality of gas small holes are provided on the central nozzle. The plurality of gas small holes are evenly distributed on the central nozzle. The central nozzle is communicated with natural gas. The central nozzle is used for stabilizing the flame. A plurality of swirl vanes 9 are arranged at the outer circle of the flame plate 7. A plurality of chutes 10 are provided at equal intervals at the outer circle of the flame plate 7. Rotating connecting legs 11 and sliding connecting legs 12 are respectively fixedly installed on the swirl vanes 9. The rotating connecting legs 11 drive the swirl vanes 9 to be rotatably installed at the outer circle of the flame plate 7. The sliding connecting legs 12 drive the swirl vanes 9 to be slidably installed at the outer circle of the flame plate 7 through the chutes 10. A heat insulation ring 13 made of heat insulation material is threadedly installed at the outer circle of the flame plate 7. A small connecting column 20 is fixedly installed at a position on the outer side surface of the swirl vane 9 close to the sliding connecting leg 12. The swirl vane 9 is fixedly connected to the heat insulation ring 13 through the small connecting column 20. By rotating the heat insulation ring 13, the heat insulation ring 13 moves back and forth on the flame plate 7. During the back-and-forth movement of the heat insulation ring 13, the swirl vanes 9 will be driven through the small connecting column 20, so that the swirl vanes 9 move back and forth through the sliding connecting legs 12 on one side away from the rotating connecting legs 11 in the chutes 10. By rotating the heat insulation ring 13, the swirl vanes 9 are driven to flip, so as to adjust the angle between the swirl vanes 9 and the flame plate 7. When the angle between the plurality of swirl vanes 9 and the flame plate 7 is larger, the gap between the swirl vanes 9 and the flame plate 7 is larger. The air swirl function is achieved through the gap formed between the swirl vanes 9 and the flame plate 7. A plurality of air holes 21 are provided through the flame plate 7;

[0036] On the burner housing 1, a plurality of air pipes 14 are threadedly installed through a plurality of air pipe connection ports 3. The air pipes 14 include injection pipes 15, mixing pipes 16 and threaded sections 17. On the outer surface of the outer circle of the injection pipe 15, on the side far from the mixing pipe 16, a threaded section 17 is provided. At the end position of the injection pipe 15 close to the mixing pipe 16, a plurality of inner expansion strips 18 with elastic characteristics are fixedly installed. The inner expansion strips 18 are distributed in an expanded state away from the injection pipe 15 at one end of the injection pipe 15 far from the threaded section 17. At the end position of one end of the mixing pipe 16, a plurality of outer fastening strips 19 with elastic characteristics are fixedly installed. The plurality of outer fastening strips 19 are distributed in a contracted state away from the mixing pipe 16. When the injection pipe 15 is sleeved and installed inside the mixing pipe 16, the injection pipe 15 expands through the plurality of inner expansion strips 18 and presses against the inner wall surface of the mixing pipe 16, so that the injection pipe 15 is fixedly sleeved inside the mixing pipe 16. When the injection pipe 15 is sleeved and installed inside the mixing pipe 16, the mixing pipe 16 contracts and presses against the outer wall surface of the injection pipe 15 through the plurality of outer fastening strips 19, so as to further firmly sleeve the injection pipe 15 inside the mixing pipe 16. The injection pipe 15 and the mixing pipe 16 are firmly connected and installed together through the mutual cooperation of the plurality of inner expansion strips 18 and the outer fastening strips 19. A part of the air is transported through the plurality of air pipes 14, passes through the air outer cavity and then is sent into the furnace chamber. Another part of the air is sent into the furnace chamber through the gaps between the plurality of swirl vanes 9 and the flame plate 7. The fuel gas is delivered to the inside of the furnace chamber through two paths. Most of the fuel gas is transported through the plurality of fuel gas pipes, passes through the fuel gas cavity and then reaches the furnace chamber. A small part of the fuel gas is transported into the furnace chamber through the central fuel gas pipe 6;

[0037] On the connecting sleeve 2, a plurality of fuel gas pipes are threadedly installed through a plurality of fuel gas pipe connection ports 4. The structure of the fuel gas pipes is the same as that of the air pipes 14. Most of the fuel gas is transported through the plurality of fuel gas pipes, passes through the inner fuel gas cavity and then reaches the furnace chamber. A small part of the fuel gas is transported into the furnace chamber through the central fuel gas pipe 6. A small part of the fuel gas is input into the furnace chamber through the central fuel gas pipe 6 for the convenience of ignition and for the function of stabilizing the flame. The air also reaches the furnace chamber through two paths. A part of the air is transported through the plurality of air pipes 14, passes through the air outer cavity and then is sent into the furnace chamber. Another part of the air is sent into the furnace chamber through the gaps between the plurality of swirl vanes 9 and the flame plate 7. The fuel gas and the air are both sent into the furnace chamber through two paths, so that the fuel gas and the air reaching the fuel gas inner cavity and the air outer cavity are fully mixed and then reach the furnace chamber.

[0038] Working principle of the present invention: The fuel gas is delivered to the inside of the furnace through two paths. Most of the fuel gas is transported through multiple groups of gas pipes, passes through the gas cavity, and then reaches the furnace. A small part of the fuel gas is delivered into the furnace through the central gas pipe 6. The air is also delivered to the inside of the furnace through two paths. Part of the air is transported through multiple groups of air pipes 14, passes through the outer air cavity, and then is sent into the furnace. Another part of the air is sent into the furnace through the gap between multiple groups of swirl vanes 9 and the flame plate 7. The fuel gas and the air are both delivered into the furnace through two paths, so that the fuel gas and the air reaching the gas inner cavity and the outer air cavity are fully mixed and then reach the furnace.

[0039] The multiple groups of swirl vanes 9 provided effectively disperse the central air, reduce the gas flow rate of the direct-flow burner head, enable the air and the fuel gas in the inner sleeve 5 to be well mixed and then burned, and improve the combustion efficiency.

[0040] By rotating the heat insulation ring 13, the heat insulation ring 13 moves back and forth on the flame plate 7. During the back-and-forth movement of the heat insulation ring 13, the swirl vanes 9 will be driven to move by the small connecting posts 20, so that the swirl vanes 9 move back and forth in the chute 10 through the sliding connecting legs 12 on the side away from the rotating connecting legs 11. By rotating the heat insulation ring 13 to drive the swirl vanes 9 to flip, the included angle between the swirl vanes 9 and the flame plate 7 is adjusted. When the included angle between multiple groups of swirl vanes 9 and the flame plate 7 is larger, the gap between the swirl vanes 9 and the flame plate 7 is larger, and the air swirl effect is achieved through the gap formed between the swirl vanes 9 and the flame plate 7.

[0041] When the injection pipe 15 is sleeved and installed inside the mixing pipe 16, the injection pipe 15 expands through multiple groups of inner expansion strips 18 and squeezes the inner wall surface of the mixing pipe 16, so that the injection pipe 15 is fixedly sleeved inside the mixing pipe 16. When the injection pipe 15 is sleeved and installed inside the mixing pipe 16, the mixing pipe 16 contracts and squeezes the outer wall surface of the injection pipe 15 through multiple groups of outer fastening strips 19, so as to further firmly sleeve the injection pipe 15 inside the mixing pipe 16. The injection pipe 15 and the mixing pipe 16 are firmly connected and installed together through the mutual cooperation of multiple groups of inner expansion strips 18 and outer fastening strips 19.

[0042] The above shows and describes the basic principle, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-nitrogen burner based on flue gas internal circulation, comprising a burner housing (1), characterized in that: At the center position of the burner housing (1), a connecting sleeve (2) is fixedly spliced in an embedded manner. A cavity is formed between the outer wall surface of the connecting sleeve (2) inside the burner housing (1) and the inner wall surface of the burner housing (1). The cavity formed between the burner housing (1) and the connecting sleeve (2) is the outer air cavity, and the inner space of the connecting sleeve (2) inside the burner housing (1) is the inner gas cavity. At the center position of the connecting sleeve (2), an inner sleeve (5) is fixedly spliced. On the front side of the burner housing (1), a plurality of air pipe connection ports (3) communicating with the outer air cavity are formed in a circular array. On the front side of the connecting sleeve (2), a plurality of gas pipe connection ports (4) communicating with the inner gas cavity are formed in a circular array. Threads are provided on the inner wall surfaces of the air pipe connection ports (3) and the gas pipe connection ports (4). A plurality of support plates (8) are fixedly installed at equal intervals on the inner wall surface of the inner sleeve (5). A flame plate (7) is fixedly installed inside the inner sleeve (5) through a plurality of support plates (8). A plurality of swirl vanes (9) are arranged at the outer circle of the flame plate (7). A plurality of chutes (10) are opened at equal intervals at the outer circle of the flame plate (7). Rotating connecting legs (11) and sliding connecting legs (12) are respectively fixedly installed on the swirl vanes (9). The rotating connecting legs (11) drive the swirl vanes (9) to be rotatably installed at the outer circle of the flame plate (7), and the sliding connecting legs (12) drive the swirl vanes (9) to be slidably installed at the outer circle of the flame plate (7) through the chutes (10). A heat insulation ring (13) made of heat insulation material is threadedly installed at the outer circle of the flame plate (7). A small connecting column (20) is fixedly installed at a position close to the sliding connecting leg (12) on the outer side surface of the swirl vane (9). The swirl vane (9) is fixedly connected to the heat insulation ring (13) through the small connecting column (20); A plurality of air pipes (14) are threadedly installed on the burner housing (1) through a plurality of air pipe connection ports (3). The air pipes (14) include injection pipes (15), mixing pipes (16), and threaded sections (17). The injection pipes (15) are sleeved inside the mixing pipes (16); A plurality of gas pipes are threadedly installed on the connecting sleeve (2) through a plurality of gas pipe connection ports (4). The structure of the gas pipes is the same as that of the air pipes (14).

2. The low-nitrogen burner based on flue gas internal circulation according to claim 1, characterized in that: The flame plate (7) is coaxially arranged inside the inner sleeve (5). A central gas pipe (6) is fixedly sleeved at the center position of the flame plate (7). A central nozzle is fixedly installed inside the central gas pipe (6) inside the flame plate (7). A plurality of gas small holes are provided on the central nozzle, and the plurality of gas small holes are evenly distributed on the central nozzle.

3. The low-nitrogen burner based on flue gas internal circulation according to claim 1, characterized in that: A plurality of air holes (21) are formed through the flame plate (7).

4. The low-nitrogen burner based on flue gas internal circulation according to claim 1, wherein: A threaded section (17) is provided on the outer surface of the outer circle of the injection pipe (15) away from the mixing pipe (16).

5. The low-nitrogen burner based on flue gas internal circulation according to claim 4, characterized in that: At the end position of one end of the injection pipe (15) close to the mixing pipe (16), a plurality of inner expansion strips (18) with elastic characteristics are fixedly installed. The inner expansion strips (18) are distributed in an expanded shape away from the injection pipe (15) at one end of the injection pipe (15) away from the threaded section (17).

6. The low-nitrogen burner based on flue gas internal circulation according to claim 1, wherein: At the end position of one end of the mixing pipe (16), a plurality of outer fastening strips (19) with elastic characteristics are fixedly installed. The plurality of outer fastening strips (19) are distributed in a contracted shape away from the mixing pipe (16).

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