Burners and pyrolysis furnaces

Abstract

This invention discloses a burner and a pyrolysis furnace. The burner includes a premixing device, a gas injection pipe, a nozzle, and a straight injection pipe. The premixing device has a shell, inside which a mixing chamber is formed. The shell includes a front wall, a rear wall, and an annular sidewall extending towards the combustion end. The front wall is connected to the end of the annular sidewall near the combustion end, and the rear wall is connected to the end of the annular sidewall away from the combustion end. An air inlet is provided on the rear wall. The gas injection pipe penetrates the rear wall and extends into the mixing chamber. A gas outlet is provided on the wall of the gas injection pipe. The nozzle penetrates the side of the annular sidewall near the combustion end and is spaced apart circumferentially on the annular sidewall. Swirl vanes are provided inside the nozzle and are connected to the inner wall of the nozzle. The straight injection pipe penetrates the side of the annular sidewall near the combustion end. This burner can improve combustion stability and gas burnout rate, thereby reducing gas consumption and CO content in flue gas, and improving economic efficiency.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, and more specifically, to a burner and a pyrolysis furnace. Background Technology

[0002] Cracking furnaces are key equipment in petroleum refining and chemical production. During operation, burners continuously heat the furnace walls, with the flames close to the furnace walls and no visible flame inside the furnace chamber. Therefore, the quality of burner operation has a significant impact on the cracking furnace. Due to these requirements, the burners are positioned on the side walls of the petrochemical furnace, and fuel is injected radially along the burners, forming a ring-shaped flame.

[0003] In related technologies, to ensure uniform heating of the furnace walls, a single pyrolysis furnace is equipped with 120-140 burners. Each burner has a relatively small power output, typically around 60 kW. The burner spacing within the pyrolysis furnace is approximately 3 meters. Since the annular flame should cover as much of the furnace sidewalls as possible, its radius is generally no less than 1.2 meters. The burners typically employ a premixed small-aperture jet combustion method. To maintain the flame radius, the jet velocity is generally high, leading to unstable combustion. In actual operation, reducing the air volume to decrease the injection velocity further reduces fuel burnout, increases CO content in the flue gas, increases fuel consumption, and reduces economic efficiency. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to provide a burner and pyrolysis furnace that can improve combustion stability and fuel gas burnout rate, thereby reducing fuel gas consumption and CO content in flue gas, and improving economic efficiency.

[0005] In one aspect of the invention, a burner is provided. According to an embodiment of the invention, the burner includes:

[0006] A premixing device has a housing, inside which a mixing chamber is formed. The housing includes a front wall, a rear wall, and an annular sidewall extending in a direction close to the combustion end. The front wall is connected to the end of the annular sidewall near the combustion end, and the rear wall is connected to the end of the annular sidewall away from the combustion end. An air inlet is provided on the rear wall.

[0007] A gas nozzle, which penetrates the rear wall and extends into the mixing chamber, has a gas outlet on its pipe wall;

[0008] The nozzle penetrates the annular sidewall near the combustion end and is spaced apart in the circumferential direction of the annular sidewall. The nozzle is provided with swirl vanes, which are connected to the inner wall of the nozzle.

[0009] The injection straight pipe extends through the annular sidewall near the combustion end and is spaced apart circumferentially on the annular sidewall, the injection straight pipe being located on at least one side of the nozzle circumferentially.

[0010] According to the burner of the above embodiments of the present invention, a mixing chamber is formed inside the housing of the premixing device, and a gas injection pipe is provided that penetrates the rear wall of the housing and extends into the mixing chamber, as well as a nozzle and a straight injection pipe that penetrate the annular sidewall near the combustion end. Gas is injected into the mixing chamber through the gas outlet of the gas injection pipe, and air enters the mixing chamber through the air inlet on the rear wall. The gas and air are mixed in the mixing chamber to obtain a mixed gas. The mixed gas is then injected into the furnace through the nozzle and the straight injection pipe for combustion, forming an annular flame. The nozzle is equipped with swirl vanes, which can create a certain resistance to the mixed gas, reducing the jet velocity, thereby... This invention avoids combustion instability caused by excessively high jet velocity and eliminates the need to reduce air volume, thus preventing a decrease in combustion efficiency due to insufficient air. Furthermore, it enhances the mixing of air and fuel gas in the mixture, improving its uniformity. Additionally, it creates a recirculation zone, which improves combustion stability and combustion efficiency, reduces fuel consumption and CO content in flue gas, and increases economic efficiency. Compared to nozzles, the jet velocity of the straight jet is faster, allowing it to reach a greater distance from the burner within the furnace. This improves combustion stability and combustion efficiency while ensuring a more uniform flame distribution within the furnace. Therefore, the burner of this invention improves combustion stability and combustion efficiency, thereby reducing fuel consumption and CO content in flue gas, increasing economic efficiency, and ensuring a more uniform flame distribution within the furnace.

[0011] In addition, the burner according to the above embodiments of the present invention may also have the following additional technical features:

[0012] In some embodiments of the present invention, the nozzle sequentially includes a converging section, a throat, and a diverging section along the material flow direction. The converging section contains the swirl vanes, the throat contains a connecting rod, and one end of the swirl vanes is connected to one end of the connecting rod. The diverging section contains a blunt body, and the other end of the connecting rod is connected to the blunt body. This improves combustion stability and fuel burnout rate, reduces fuel consumption and CO content in flue gas, and enhances economic efficiency.

[0013] In some embodiments of the present invention, the blunt body is conical, and the cross-sectional area of ​​the blunt body gradually increases along the material flow direction.

[0014] In some embodiments of the present invention, the angle between the swirl blade and the central axis does not exceed 30°.

[0015] In some embodiments of the present invention, the angle between the gas outlet's outlet direction and the air inlet's inlet direction is not less than 90°. This is beneficial for improving gas burnout rate, reducing gas consumption and CO content in flue gas, and improving economic efficiency.

[0016] In some embodiments of the present invention, the nozzles are uniformly distributed circumferentially on the annular sidewall, and the injection straight pipes are uniformly distributed circumferentially on the nozzles. This facilitates the control of thermal NO. X The generation of .

[0017] In some embodiments of the present invention, the annular sidewall comprises, from the outside in, an outer annular sidewall, a middle annular sidewall, and an inner annular sidewall arranged coaxially. The end of the outer annular sidewall near the combustion end is connected to the front wall. A first notch is provided between the end of the middle annular sidewall near the combustion end and the inner wall of the front wall. The end of the middle annular sidewall away from the combustion end is connected to the rear wall. An outer air passage is formed between the inner wall of the outer annular sidewall and the outer wall of the middle annular sidewall, and this outer air passage communicates with the air inlet. A second notch is provided between the end of the inner annular sidewall away from the combustion end and the inner wall of the rear wall. The end of the inner annular sidewall near the combustion end is connected to the front wall. An inner air passage is formed between the inner wall of the middle annular sidewall and the outer wall of the inner annular sidewall. Therefore, on the one hand, it can prevent the fuel-air mixture from burning in the mixing chamber and causing a safety accident; on the other hand, it can help improve combustion stability.

[0018] In some embodiments of the present invention, the front wall comprises an outer front wall and an inner front wall from the outside in. The outer front wall is connected to the end of the outer annular sidewall near the combustion end, and the inner front wall is connected to the end of the inner annular sidewall near the combustion end. An end air passage is formed between the outer wall of the inner front wall and the inner wall of the outer front wall. This prevents the fuel-air mixture from burning within the mixing chamber and thus avoiding safety accidents, while also improving combustion stability.

[0019] In some embodiments of the present invention, the burner further includes: an air duct connected to one end of the outer annular sidewall away from the combustion end; and a gas duct penetrating the wall of the air duct and connected to one end of the gas nozzle away from the mixing chamber.

[0020] In another aspect, the present invention provides a pyrolysis furnace. According to an embodiment of the invention, the pyrolysis furnace is equipped with the burner described in any of the preceding embodiments. This improves the combustion rate of the fuel gas in the pyrolysis furnace, thereby reducing fuel gas consumption and CO content in the flue gas, improving economic efficiency, and allowing for a more uniform flame distribution within the furnace.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a schematic diagram of the longitudinal section structure of a burner according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the longitudinal section structure of a premixing device according to an embodiment of the present invention.

[0025] Figure label:

[0026] 100-Premixing device; 110-Shell; 111-Front wall; 1111-Outer front wall; 1112-Inner front wall; 1113-End air passage; 112-Rear wall; 1121-Air inlet; 113-Annular side wall; 1131-Outer annular side wall; 1132-Middle annular side wall; 1133-Inner annular side wall; 1134-First notch; 1135-Outer air passage; 1136-Second notch; 1137-Inner air passage; 120-Mixing chamber; 200-Gas injector; 210-Gas outlet; 300-Nozzle; 310-Swirl vane; 320-Converging section; 330-Throat; 331-Connecting rod; 340-Diverging section; 341-Blunt body; 400-Injection straight pipe; 500-Furnace wall; 600-Air duct; 700-Gas duct. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] In one aspect of the invention, a burner is provided. According to an embodiment of the invention, reference is made to... Figure 1-2 The burner includes a premixing device 100, a gas injection pipe 200, a nozzle 300, and an injection straight pipe 400. The burner according to an embodiment of the present invention will be further described in detail below.

[0033] According to an embodiment of the present invention, reference Figure 1-2 The premixing device 100 has a housing 110, inside which a mixing chamber 120 is formed. The housing 110 may include a front wall 111, a rear wall 112, and an annular sidewall 113 extending in the direction close to the combustion end. The front wall 111 is connected to the end of the annular sidewall 113 near the combustion end, and the rear wall 112 is connected to the end of the annular sidewall 113 away from the combustion end. An air inlet 1121 is provided on the rear wall 112, through which air can enter the mixing chamber 120 and mix with the gas entering the mixing chamber 120 through the gas injector 200 to obtain a mixed gas. Specifically, the burner can be fixed to the furnace wall 500 by a flange, and the annular sidewall 113 can extend into the furnace through the furnace wall 500.

[0034] According to a specific embodiment of the present invention, reference is made to Figure 2 The annular sidewall 113 comprises, from the outside in, an outer annular sidewall 1131, a middle annular sidewall 1132, and an inner annular sidewall 1133, all coaxially arranged. The outer annular sidewall 1131, near the combustion end, is connected to the front wall 111. The middle annular sidewall 1132, near the combustion end, has a first notch 1134 between it and the inner wall of the front wall 111. The middle annular sidewall 1132, away from the combustion end, is connected to the rear wall 112. The inner wall of the outer annular sidewall 1131... An outer air passage 1135 is formed between the inner wall and the outer wall of the middle annular sidewall 1132. The outer air passage 1135 is connected to the air inlet 1121. A second notch 1136 is provided between the end of the inner annular sidewall 1133 away from the combustion end and the inner wall of the rear wall 112. The end of the inner annular sidewall 1133 near the combustion end is connected to the front wall 111. An inner air passage 1137 is formed between the inner wall of the middle annular sidewall 1132 and the outer wall of the inner annular sidewall 1133. Specifically, air can enter the outer air channel 1135 through the air inlet 1121 on the rear wall 112, then enter the inner air channel 1137 through the first gap 1134, and finally enter the mixing chamber 120 through the second gap 1136. Thus, on the one hand, the area of ​​the annular sidewall 113 that is in direct contact with the high-temperature zone of the furnace can be cooled by air, which helps to reduce the temperature in the mixing chamber 120 and prevent the fuel-air mixture from burning in the mixing chamber 120 and causing a safety accident. On the other hand, the temperature of the area of ​​the annular sidewall 113 that is in direct contact with the high-temperature zone of the furnace is increased after the air cools it, which can help improve combustion stability.

[0035] According to another specific embodiment of the present invention, reference is made to Figure 2The front wall 111 includes an outer front wall 1111 and an inner front wall 1112 from the outside to the inside. The outer front wall 1111 is connected to the end of the outer annular side wall 1131 near the combustion end. The inner front wall 1112 is connected to the end of the inner annular side wall 1133 near the combustion end. An end air passage 1113 is formed between the outer wall of the inner front wall 1112 and the inner wall of the outer front wall 1111. Specifically, the outer air channel 1135 and the inner air channel 1137 are respectively connected to the end air channel 1113. Air can enter the outer air channel 1135 through the air inlet 1121 on the rear wall 112, then enter the end air channel 1113 through the first notch 1134, then enter the inner air channel 1137 through the first notch 1134, and finally enter the mixing chamber 120 through the second notch 1136. Thus, on the one hand, the areas of the annular sidewall 113 and the front wall 111 that are in direct contact with the high-temperature zone of the furnace can be cooled by the air, which is conducive to reducing the temperature of the air-fuel mixture in the mixing chamber 120 and preventing the fuel-air mixture from burning in the mixing chamber 120 and causing a safety accident. On the other hand, the temperature of the areas of the annular sidewall 113 and the front wall 111 that are in direct contact with the high-temperature zone of the furnace is increased after the air cools them, which is conducive to improving combustion stability.

[0036] According to an embodiment of the present invention, reference Figure 2 The gas nozzle 200 penetrates the rear wall 112 and extends into the mixing chamber 120. A gas outlet 210 is provided on the pipe wall of the gas nozzle 200. Specifically, gas is injected into the mixing chamber 120 through the gas outlet 210 of the gas nozzle 200, and air enters the mixing chamber 120 through the air inlet 1121 on the rear wall 112. The gas and air are mixed in the mixing chamber 120 to obtain a mixed gas.

[0037] Specifically, the angle between the gas outlet 210 and the air inlet 1121 is not less than 90°. This allows the gas and air to collide, ensuring thorough mixing within a limited mixing distance. This improves the gas burnout rate, reduces gas consumption and CO content in the flue gas, and ultimately increases economic efficiency.

[0038] According to an embodiment of the present invention, reference Figure 2The nozzle 300 penetrates the annular sidewall 113 near the combustion end and is spaced out circumferentially along the annular sidewall 113. A swirl vane 310 is provided inside the nozzle 300 and connected to the inner wall of the nozzle 300. Thus, the swirl vane 310 can, on the one hand, create resistance to the gas mixture, reducing the jet velocity and preventing combustion instability caused by excessive jet velocity, and eliminating the need to reduce the air volume, thus avoiding a decrease in combustion efficiency due to insufficient air volume. On the other hand, it can enhance the mixing of air and gas in the gas mixture, improving the uniformity of air-gas mixing. Furthermore, it can form a recirculation zone, which is beneficial for improving combustion stability and combustion efficiency, reducing gas consumption and CO content in flue gas, and improving economic efficiency. Specifically, the nozzles 300 are evenly distributed circumferentially along the annular sidewall 113. This helps to control the uniform distribution of gas on the burner surface, eliminating localized high-temperature zones, and thus controlling thermal NO. X The generation of .

[0039] According to another specific embodiment of the present invention, the nozzle 300 includes, in sequence along the material flow direction, a converging section 320, a throat 330, and a diverging section 340. The converging section 320 is provided with the aforementioned swirl vanes 310, the throat 330 is provided with a connecting rod 331, one end of the swirl vanes 310 is connected to one end of the connecting rod 331, and the diverging section 340 is provided with a blunt body 341, the other end of the connecting rod 331 is connected to the blunt body 341. Specifically, the air and fuel gas mixed in the mixing chamber 120 enter the throat 330 from the converging section 320 and are then injected into the furnace from the diverging section 340. An expanding airflow is formed downstream of the diverging section 340, and a swirling flow is generated under the action of the swirl vanes 310. A recirculation zone is generated under the action of the blunt body 341, entraining the surrounding high-temperature flue gas. This ensures a sufficient mixing effect between the air and fuel gas, thereby improving combustion stability and fuel burnout rate, reducing fuel consumption and CO content in the flue gas, and improving economic efficiency. It should be noted that the shape of the blunt body 341 is not particularly limited, and those skilled in the art can choose it according to actual needs. For example, the blunt body 341 is conical, and the cross-sectional area of ​​the blunt body 341 gradually increases along the material flow direction.

[0040] According to another specific embodiment of the present invention, the angle between the swirl vane 310 and the central axis does not exceed 30°. Therefore, limiting the angle between the swirl vane 310 and the central axis to the above range helps to avoid excessive airflow resistance, thereby helping to prevent problems such as backfire and improving combustion safety.

[0041] It should be noted that the specific number of swirl blades 310 in each nozzle 300 is not particularly limited, and those skilled in the art can select according to actual needs, for example, 6 to 8.

[0042] According to another specific embodiment of the present invention, each nozzle has a combustion power of about 5kW. At this power, the injection speed of the gas-air mixture is greater than the flame propagation speed, which effectively prevents problems such as backfire and improves combustion safety. At the same time, it also ensures that the flame is not completely blown away and thus extinguished.

[0043] According to an embodiment of the present invention, the injection straight pipe 400 penetrates the side of the annular sidewall 113 near the combustion end and is spaced apart circumferentially on the annular sidewall 113. The injection straight pipe 400 is located on at least one side of the nozzle 300 circumferentially. Specifically, after the air and fuel are fully mixed, they are directly injected into the furnace through the injection straight pipe 400. Compared with the nozzle 300, the jet velocity of the injection straight pipe 400 is faster, and it can reach a space in the furnace farther from the burner, making the flame more uniformly distributed in the furnace.

[0044] According to another specific embodiment of the present invention, the injection straight pipes 400 are uniformly distributed circumferentially around the nozzle 300. This further facilitates the control of uniform gas distribution on the burner surface, eliminates localized high-temperature zones, and thus further facilitates the control of thermal NO₂. X The generation of .

[0045] According to an embodiment of the present invention, the burner further includes an air duct 600 and a gas duct 700. The air duct 600 is connected to the end of the outer annular sidewall 1131 away from the combustion end and is used to introduce air or other combustion aids. The gas duct 700 penetrates the wall of the air duct 600 and is connected to the end of the gas nozzle 200 away from the mixing chamber 120 and is used to introduce gas.

[0046] According to the burner of the above embodiment of the present invention, a mixing chamber 120 is formed inside the housing of the premixing device 100, and a gas injection pipe 200 is provided that penetrates the rear wall 112 of the housing 110 and extends into the mixing chamber 120, as well as a nozzle 300 and an injection straight pipe 400 that penetrate the annular sidewall 113 near the combustion end. Gas is injected into the mixing chamber 120 through the gas outlet 210 of the gas injection pipe 200, and air enters the mixing chamber 120 through the air inlet 1121 on the rear wall 112. The gas and air are mixed in the mixing chamber 120 to obtain a mixed gas. The mixed gas is injected into the furnace through the nozzle 300 and the injection straight pipe 400 for combustion to form an annular flame. The nozzle 300 is provided with a swirl vane 310. The nozzle 310 provides resistance to the gas mixture, reducing the jet velocity and preventing combustion instability caused by excessively high jet velocity. It also eliminates the need to reduce air volume, preventing a decrease in burnout rate due to insufficient air. Furthermore, it enhances the mixing of air and gas, improving the uniformity of the mixture. Additionally, it creates a recirculation zone, which improves combustion stability and burnout rate, reduces gas consumption and CO content in flue gas, and increases economic efficiency. Compared to the nozzle 300, the jet velocity of the straight injection pipe 400 is faster, allowing it to reach a greater distance from the burner within the furnace. This improves combustion stability and burnout rate while ensuring a more uniform flame distribution within the furnace. Therefore, the burner of this invention improves combustion stability and burnout rate, reducing gas consumption and CO content in flue gas, increasing economic efficiency, and ensuring a more uniform flame distribution within the furnace. Moreover, this burner can be installed in burner mounting holes of limited diameter, adapting to the structure of most existing heating furnace combustion chambers.

[0047] In another aspect, the present invention provides a pyrolysis furnace. According to embodiments of the invention, the pyrolysis furnace is equipped with a burner provided in any of the above embodiments. This improves the combustion rate of the fuel gas in the pyrolysis furnace, thereby reducing fuel gas consumption and CO content in the flue gas, improving economic efficiency, and allowing for a more uniform flame distribution within the furnace. It should be noted that the features and advantages described above for the burner also apply to this pyrolysis furnace, and will not be repeated here.

[0048] According to an embodiment of the present invention, the pyrolysis furnace may further include an ignition gun assembly, which may be disposed above or below the burner. Specifically, the ignition gun assembly may include an ignition electrode and an ignition gas pipe.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A burner, characterized by The application relates to a premixing device for a gas combustion device. The premixing device comprises a housing, a mixing cavity is formed inside the housing, the housing comprises a front wall, a rear wall and an annular side wall extending in the direction close to a combustion end, the front wall is connected with one end of the annular side wall close to the combustion end, the rear wall is connected with one end of the annular side wall away from the combustion end, and an air inlet is arranged on the rear wall. A gas injection pipe is arranged through the rear wall and extends into the mixing cavity, and a gas outlet is arranged on the pipe wall of the gas injection pipe. A nozzle is arranged through one side of the annular side wall close to the combustion end and is distributed at intervals in the circumferential direction of the annular side wall, a rotating flow vane is arranged in the nozzle, and the rotating flow vane is connected with the inner wall of the nozzle. A jet straight pipe is arranged through one side of the annular side wall close to the combustion end and is distributed at intervals in the circumferential direction of the annular side wall, and the jet straight pipe is located at least one side of the nozzle in the circumferential direction.

2. The burner of claim 1, wherein The nozzle comprises a converging section, a throat section and a diverging section in sequence along the material flow direction, the rotating flow vane is arranged in the converging section, a connecting rod is arranged in the throat section, one end of the rotating flow vane is connected with the connecting rod, a blunt body is arranged in the diverging section, and the other end of the connecting rod is connected with the blunt body.

3. The burner of claim 2, wherein The blunt body is conical, and the cross-sectional area of the blunt body gradually increases along the material flow direction.

4. The burner of claim 1, wherein The angle between the rotating flow vane and the central axis is not more than 30 DEG.

5. The burner of claim 1, wherein The angle between the gas outlet direction of the gas outlet and the air inlet direction of the air inlet is not less than 90 DEG.

6. The burner of claim 1, wherein The nozzles are uniformly distributed in the circumferential direction of the annular side wall, and the jet straight pipes are uniformly distributed in the circumferential direction of the nozzles.

7. The burner of claim 1, wherein The annular side wall comprises an outer annular side wall, a middle annular side wall and an inner annular side wall arranged coaxially in sequence from outside to inside, one end of the outer annular side wall close to the combustion end is connected with the front wall, a first gap is arranged between one end of the middle annular side wall close to the combustion end and the inner wall of the front wall, one end of the middle annular side wall away from the combustion end is connected with the rear wall, an outer air channel is formed between the inner wall of the outer annular side wall and the outer wall of the middle annular side wall, the outer air channel is communicated with the air inlet, a second gap is arranged between one end of the inner annular side wall away from the combustion end and the inner wall of the rear wall, one end of the inner annular side wall close to the combustion end is connected with the front wall, and an inner air channel is formed between the inner wall of the middle annular side wall and the outer wall of the inner annular side wall.

8. The burner of claim 7, wherein The front wall comprises an outer front wall and an inner front wall arranged in sequence from outside to inside, one end of the outer front wall close to the combustion end is connected with the outer annular side wall, one end of the inner front wall close to the combustion end is connected with the inner annular side wall, and an end air channel is formed between the outer wall of the inner front wall and the inner wall of the outer front wall.

9. The burner of claim 7, wherein The application further relates to an air pipeline connected with one end of the outer annular side wall away from the combustion end and a gas pipeline arranged through the pipe wall of the air pipeline and connected with one end of the gas injection pipe away from the mixing cavity. ​ ​ 10. A cracking furnace characterized by comprising: The cracking furnace is provided with the combustor according to any one of claims 1-9.

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