Combustor and cracking furnace

Abstract

The invention discloses a combustor and a cracking furnace, and the combustor comprises a premixing device, a fuel gas spraying pipe, a nozzle and a spraying straight pipe. The premixing device is provided with a shell, a gas mixing cavity is formed in the shell, the shell comprises a front wall, a rear wall and an annular side wall extending in the direction close to the combustion end, the front wall is connected with the end, close to the combustion end, of the annular side wall, the rear wall is connected with the end, away from the combustion end, of the annular side wall, and an air inlet is formed in the rear wall. The fuel gas spraying pipe penetrates through the rear wall and extends into the gas mixing cavity, a fuel gas outlet is formed in the pipe wall of the fuel gas spraying pipe, the nozzles penetrate through the side, close to the combustion end, of the annular side wall and are distributed in the circumferential direction of the annular side wall at intervals, rotational flow blades are arranged in the nozzles, and the rotational flow blades are connected with the inner walls of the nozzles. The injection straight pipe penetrates through the side, close to the combustion end, of the annular side wall. The combustor can improve the combustion stability and the fuel gas burn-off rate, so that the fuel gas consumption and the CO content in flue gas are reduced, and the economic benefits are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical equipment, and in particular to a burner and a cracking furnace. Background Art

[0002] The cracking furnace is the main equipment for petroleum refining production. During the operation of the cracking furnace, the burner needs to provide heat to continuously heat the furnace wall. The flame is close to the furnace wall as a whole, and there is no obvious flame inside the furnace. Therefore, the operation of the burner will have a huge impact on the cracking furnace. Due to the above requirements, the burner is arranged on the side wall of the petrochemical furnace, and the fuel is sprayed radially along the burner to form a ring flame.

[0003] In the related art, in order to ensure uniform heating of the furnace wall, a single cracking furnace is equipped with 120-140 burners, and the power of a single burner is relatively small, generally about 60kw. The installation spacing of the burners in the cracking furnace is about 3m. Since the annular flame should cover the side wall of the cracking furnace as much as possible, the radius of the annular flame is generally not less than 1.2m. The burner generally adopts a premixed small hole jet combustion method. In order to ensure the flame radius, the jet velocity is generally high, resulting in unstable combustion. In actual operation, the main method is to reduce the air volume and thus reduce the injection velocity, which also leads to a low fuel burnout rate, an increase in the CO content in the flue gas, an increase in fuel consumption, and a decrease in economic benefits. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide a burner and a cracking furnace, which can improve the combustion stability and the gas burnout rate, thereby reducing the gas consumption and the CO content in the flue gas and improving the economic benefits.

[0005] In one aspect of the present invention, the present invention provides a burner. According to an embodiment of the present invention, the burner comprises:

[0006] A premixing device, the premixing device having a shell, an air mixing chamber formed inside the shell, the shell comprising a front wall, a rear wall and an annular side wall extending in a direction close to the combustion end, the front wall is connected to an end of the annular side wall close to the combustion end, the rear wall is connected to an end of the annular side wall away from the combustion end, and an air inlet is provided on the rear wall;

[0007] A gas nozzle, the gas nozzle passes through the rear wall and extends into the gas mixing chamber, and a gas outlet is provided on the wall of the gas nozzle;

[0008] A nozzle, wherein the nozzle penetrates a side of the annular side wall close to the combustion end and is spaced apart in the circumferential direction of the annular side wall, wherein a swirl blade is provided in the nozzle and the swirl blade is connected to the inner wall of the nozzle;

[0009] The straight injection pipe penetrates through the 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. The straight injection pipe is located on at least one side of the circumference of the nozzle.

[0010] According to the burner of the above embodiment of the present invention, a gas mixing chamber is formed inside the shell of the premixing device, and a gas nozzle penetrating the rear wall of the shell and extending into the gas mixing chamber is provided, as well as a nozzle and a straight injection pipe penetrating the annular side wall on the side close to the combustion end. Gas is sprayed into the gas mixing chamber through the gas outlet of the gas nozzle, and air enters the gas mixing chamber through the air inlet on the rear wall. Gas and air are mixed in the gas mixing chamber to obtain a mixed gas. The mixed gas is sprayed into the furnace through the nozzle and the straight injection pipe respectively for combustion to form an annular flame. Swirl blades are provided in the nozzle. The swirl blades can form a certain resistance to the mixed gas and reduce the jet speed, thereby It avoids unstable combustion caused by too fast jet speed, and there is no need to reduce the air volume, thereby avoiding the reduction of gas burnout rate due to too low air volume. On the one hand, it can enhance the mixing of air and gas in the mixed gas and improve the uniformity of the mixing of air and gas. On the other hand, it can form a reflow zone, which is conducive to improving combustion stability and gas burnout rate, reducing gas consumption and CO content in flue gas, and improving economic benefits. Compared with the nozzle, the jet speed of the jet straight pipe is faster and can reach the space farther away from the burner in the furnace, so that the flame can be distributed more evenly in the furnace while improving the combustion stability and gas burnout rate. Therefore, the burner of the present invention can improve the combustion stability and gas burnout rate, thereby reducing gas consumption and CO content in flue gas, improving economic benefits, and can make the flame more evenly distributed in the furnace.

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

[0012] In some embodiments of the present invention, the nozzle includes a gradually contracting section, a throat and a gradually expanding section in sequence along the material flow direction, the gradually contracting section is provided with the swirl blade, the throat is provided with a connecting rod, the swirl blade is connected to one end of the connecting rod, the gradually expanding section is provided with a blunt body, and the other end of the connecting rod is connected to the blunt body. This is conducive to improving combustion stability and gas burnout rate, reducing gas consumption and CO content in flue gas, and improving economic benefits.

[0013] In some embodiments of the present invention, the bluff body is conical, and the cross-sectional area of ​​the bluff 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 direction and the air inlet direction is not less than 90°, thereby improving the gas burnout rate, reducing gas consumption and CO content in flue gas, and improving economic benefits.

[0016] In some embodiments of the present invention, the nozzles are evenly distributed in the circumferential direction of the annular side wall, and the injection straight pipes are evenly distributed in the circumferential direction of the nozzles. X Generation of.

[0017] In some embodiments of the present invention, the annular side wall includes an outer annular side wall, a middle annular side wall and an inner annular side wall which are coaxially arranged from outside to inside, the end of the outer annular side wall close to the combustion end is connected to the front wall, the end of the middle annular side wall close to the combustion end is provided with a first notch between the inner wall of the front wall, the end of the middle annular side wall away from the combustion end is connected to 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 connected to the air inlet, a second notch is provided between the end of the inner annular side wall away from the combustion end and the inner wall of the rear wall, the end of the inner annular side wall close to the combustion end is connected to 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. Thus, on the one hand, it can prevent the fuel and air mixture from burning in the mixing chamber and causing safety accidents, and on the other hand, it can be beneficial to improve the combustion stability.

[0018] In some embodiments of the present invention, the front wall includes an outer front wall and an inner front wall from outside to inside, the outer front wall is connected to one end of the outer annular side wall close to the combustion end, the inner front wall is connected to one end of the inner annular side wall close to the combustion end, 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. Thus, on the one hand, it can prevent the fuel and air mixture from burning in the mixing chamber and causing safety accidents, and on the other hand, it can help improve the combustion stability.

[0019] In some embodiments of the present invention, the above-mentioned burner also includes: an air duct, which is connected to the end of the outer annular side wall away from the combustion end; and a gas pipeline, which passes through the pipe wall of the air duct and is connected to the end of the gas nozzle away from the mixing chamber.

[0020] In another aspect of the present invention, the present invention provides a cracking furnace. According to an embodiment of the present invention, the cracking furnace is provided with the burner provided in any of the above embodiments. Thus, the burnout rate of the gas in the cracking furnace can be improved, thereby reducing the gas consumption and the CO content in the flue gas, improving the economic benefits, and making the flame more evenly distributed in the furnace.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0025] Reference numerals:

[0026] 100-premixing device; 110-shell; 111-front wall; 1111-outer front wall; 1112-inner front wall; 1113-end air channel; 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 channel; 1136-second notch; 1137-inner air channel; 120-mixing chamber; 200-gas nozzle; 210-gas outlet; 300-nozzle; 310-swirl blade; 320-converging section; 330-throat; 331-connecting rod; 340-expanding section; 341-blunt body; 400-injection straight pipe; 500-furnace wall; 600-air duct; 700-gas duct. DETAILED DESCRIPTION

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

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

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

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

[0034] According to a specific embodiment of the present invention, referring to Figure 2 The annular side wall 113 includes, from outside to inside, a coaxially arranged outer annular side wall 1131, a middle annular side wall 1132 and an inner annular side wall 1133. The end of the outer annular side wall 1131 close to the combustion end is connected to the front wall 111. A first notch 1134 is provided between the end of the middle annular side wall 1132 close to the combustion end and the inner wall of the front wall 111. The end of the middle annular side wall 1132 away from the combustion end is connected to the rear wall 112. The inner wall of the outer annular side wall 1131 is connected to the rear wall 112. An outer air channel 1135 is formed between the wall and the outer wall of the middle annular side wall 1132, and the outer air channel 1135 is connected to the air inlet 1121. A second notch 1136 is provided between the end of the inner annular side wall 1133 away from the combustion end and the inner wall of the rear wall 112. The end of the inner annular side wall 1133 close to the combustion end is connected to the front wall 111. An inner air channel 1137 is formed between the inner wall of the middle annular side wall 1132 and the outer wall of the inner annular side wall 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 notch 1134, and finally enter the mixing chamber 120 through the second notch 1136. Therefore, on the one hand, the air can cool the area of ​​the annular side wall 113 that directly contacts the high-temperature zone of the furnace, which is beneficial to lowering the temperature in the mixing chamber 120 and preventing the mixture of fuel and air from burning in the mixing chamber 120 and causing safety accidents. On the other hand, the air cools the area of ​​the annular side wall 113 that directly contacts the high-temperature zone of the furnace, and the temperature increases, which is beneficial to improving combustion stability.

[0035] According to another specific embodiment of the present invention, 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 an end of the outer annular side wall 1131 close to the combustion end, and the inner front wall 1112 is connected to an end of the inner annular side wall 1133 close to the combustion end. An end air channel 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, and the air can enter the outer air channel 1135 through the air inlet 1121 on the rear wall 112, and then enter the end air channel 1113 through the first notch 1134, and then enter the inner air channel 1137 through the first notch 1134, and finally enter the mixing chamber 120 through the second notch 1136. Therefore, on the one hand, the air can be used to cool the area of ​​the annular side wall 113 and the front wall 111 that directly contacts the high-temperature zone of the furnace, which is further beneficial to reduce the temperature of the mixture of air and fuel gas in the mixing chamber 120 and prevent the mixture of fuel and air from burning in the mixing chamber 120 and causing safety accidents. On the other hand, the air cools the area of ​​the annular side wall 113 and the front wall 111 that directly contacts the high-temperature zone of the furnace, and the temperature increases, which can further help improve the combustion stability.

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

[0037] Specifically, the angle between the gas outlet direction of the gas outlet 210 and the gas inlet direction of the air inlet 1121 is not less than 90°. As a result, the gas and the air collide with each other, so that the gas and the air are mixed as fully as possible within a limited mixing distance, which is beneficial to improve the gas burnout rate, reduce gas consumption and CO content in flue gas, and improve economic benefits.

[0038] According to an embodiment of the present invention, referring to Figure 2The nozzle 300 penetrates the side of the annular side wall 113 close to the combustion end, and is distributed at intervals in the circumferential direction of the annular side wall 113. A swirl blade 310 is provided in the nozzle 300, and the swirl blade 310 is connected to the inner wall of the nozzle 300. Therefore, on the one hand, the swirl blade 310 can form a certain resistance to the mixed gas, reduce the jet speed, thereby avoiding the unstable combustion caused by the jet speed being too fast, and there is no need to reduce the air volume, thereby avoiding the reduction of the gas burnout rate due to the low air volume. On the other hand, it can enhance the mixing of air and gas in the mixed gas and improve the uniformity of the mixing of air and gas. On the other hand, it can form a recirculation zone, which is beneficial to improve the combustion stability and gas burnout rate, reduce the gas consumption and CO content in the flue gas, and improve the economic benefits. Specifically, the nozzles 300 are evenly distributed in the circumferential direction of the annular side wall 113. Therefore, it is beneficial to control the gas to be evenly distributed on the surface of the burner, eliminate local high temperature areas, and control the thermal NO X Generation of.

[0039] According to another specific embodiment of the present invention, the nozzle 300 includes a tapered section 320, a throat 330 and a gradually expanding section 340 in sequence along the material flow direction, the tapered section 320 is provided with the above-mentioned swirl blade 310, the throat 330 is provided with a connecting rod 331, the swirl blade 310 is connected to one end of the connecting rod 331, and the gradually expanding section 340 is provided with a blunt body 341, and the other end of the connecting rod 331 is connected to the blunt body 341. Specifically, the air and gas mixed in the gas mixing chamber 120 enter the throat 330 from the tapered section 320 and are sprayed into the furnace from the gradually expanding section 340, and an expansion airflow is formed downstream of the gradually expanding section 340, and at the same time, a swirl is generated under the action of the swirl blade 310, and a reflow zone is generated under the action of the blunt body 341, and the surrounding high-temperature flue gas is entrained, so that the mixing effect of air and gas can be fully guaranteed, which is conducive to improving the combustion stability and the gas burnout rate, reducing the gas consumption and the CO content in the flue gas, and improving the economic benefits. It should be noted that the shape of the bluff body 341 is not particularly limited, and those skilled in the art can select it according to actual needs. For example, the bluff body 341 is conical, and the cross-sectional area of ​​the bluff body 341 gradually increases along the material flow direction.

[0040] According to another specific embodiment of the present invention, the angle between the swirl blade 310 and the central axis does not exceed 30°. Therefore, limiting the angle between the swirl blade 310 and the central axis to the above range is conducive to avoiding excessive airflow resistance, thereby preventing the occurrence of problems such as flashback and improving combustion safety.

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

[0042] According to another specific embodiment of the present invention, the combustion power of each nozzle is about 5kW. At this power, the injection speed of the gas and air mixture is greater than the flame propagation speed, which effectively prevents the occurrence of problems such as backfire, improves combustion safety, and also ensures that the flame is not completely blown out and caused to go out.

[0043] According to the embodiment of the present invention, the injection straight pipe 400 penetrates the side of the annular side wall 113 close to the combustion end, and is spaced apart in the circumferential direction of the annular side wall 113, and the injection straight pipe 400 is located on at least one side of the circumferential direction of the nozzle 300. 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 injection straight pipe 400 has a faster jet speed and can reach a space farther from the burner in the furnace, so that the flame is more evenly distributed in the furnace.

[0044] According to another specific embodiment of the present invention, the injection straight pipes 400 are evenly distributed around the nozzle 300. This can further help control the uniform distribution of the gas on the surface of the burner, eliminate local high temperature areas, and further help control the thermal NO X Generation of.

[0045] According to an embodiment of the present invention, the above-mentioned burner also includes an air duct 600 and a gas duct 700. The air duct 600 is connected to the end of the outer annular side wall 1131 away from the combustion end, and is used to introduce air and other combustion aids. The gas duct 700 passes through the pipe 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 gas mixing chamber 120 is formed inside the shell of the premixing device 100, and a gas nozzle 200 is provided which penetrates the rear wall 112 of the shell 110 and extends into the gas mixing chamber 120, and a nozzle 300 and a spray straight pipe 400 are provided which penetrate the annular side wall 113 on the side close to the combustion end. Gas is sprayed into the gas mixing chamber 120 through the gas outlet 210 of the gas nozzle 200, and air enters the gas mixing chamber 120 through the air inlet 1121 on the rear wall 112. Gas and air are mixed in the gas mixing chamber 120 to obtain a mixed gas. The mixed gas is sprayed into the furnace through the nozzle 300 and the spray straight pipe 400 respectively for combustion to form an annular flame. A swirl blade 310 is provided in the nozzle 300. The swirl blade On the one hand, the sheet 310 can form a certain resistance to the mixed gas, reduce the jet speed, thereby avoiding the combustion instability caused by the jet speed being too fast, and there is no need to reduce the air volume, thereby avoiding the reduction of the gas burnout rate due to the low air volume. On the other hand, it can enhance the mixing of air and gas in the mixed gas and improve the uniformity of the mixing of air and gas. On the other hand, it can form a reflow zone, which is conducive to improving the combustion stability and gas burnout rate, reducing the gas consumption and the CO content in the flue gas, and improving the economic benefits. Compared with the nozzle 300, the jet speed of the injection straight pipe 400 is faster, and it can reach the space farther away from the burner in the furnace, so that the flame can be distributed more evenly in the furnace while improving the combustion stability and gas burnout rate. Therefore, the burner of the present invention can improve the combustion stability and gas burnout rate, thereby reducing the gas consumption and the CO content in the flue gas, improving the economic benefits, and can make the flame more evenly distributed in the furnace. In addition, the burner can be arranged and installed on a burner mounting hole with a limited diameter, which can adapt to the structure of the combustion chamber of most existing heating furnaces.

[0047] In another aspect of the present invention, the present invention provides a cracking furnace. According to an embodiment of the present invention, the cracking furnace is provided with a burner provided by any of the above embodiments. As a result, the burnout rate of the gas in the cracking furnace can be improved, thereby reducing the gas consumption and the CO content in the flue gas, improving the economic benefits, and making the flame more evenly distributed in the furnace. It should be noted that the features and advantages described above for the burner are also applicable to the cracking furnace, and will not be repeated here.

[0048] According to an embodiment of the present invention, the cracking furnace may further include an ignition gun assembly, which may be arranged 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 description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0050] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A burner, characterized in that: include: A premixing device, the premixing device having a shell, an air mixing chamber formed inside the shell, the shell comprising a front wall, a rear wall and an annular side wall extending in a direction close to the combustion end, the front wall is connected to an end of the annular side wall close to the combustion end, the rear wall is connected to an end of the annular side wall away from the combustion end, and an air inlet is provided on the rear wall; A gas nozzle, the gas nozzle passes through the rear wall and extends into the gas mixing chamber, and a gas outlet is provided on the wall of the gas nozzle; A nozzle, wherein the nozzle penetrates a side of the annular side wall close to the combustion end and is spaced apart in the circumferential direction of the annular side wall, wherein a swirl blade is provided in the nozzle and the swirl blade is connected to the inner wall of the nozzle; The straight injection pipe penetrates through the 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. The straight injection pipe is located on at least one side of the circumference of the nozzle.

2. The burner according to claim 1, characterized in that The nozzle includes a tapered section, a throat and a gradually expanding section in sequence along the material flow direction. The swirl blade is arranged in the tapered section, a connecting rod is arranged in the throat, the swirl blade is connected to one end of the connecting rod, a blunt body is arranged in the gradually expanding section, and the other end of the connecting rod is connected to the blunt body.

3. The burner according to claim 2, characterized in that The bluff body is conical, and the cross-sectional area of ​​the bluff body gradually increases along the material flow direction.

4. The burner according to claim 1, characterized in that The angle between the swirl blade and the central axis does not exceed 30°.

5. The burner according to claim 1, characterized in that The included angle between the gas outlet direction and the air inlet direction of the air inlet is not less than 90°.

6. The burner according to claim 1, characterized in that The nozzles are evenly distributed in the circumferential direction of the annular side wall, and the injection straight pipes are evenly distributed in the circumferential direction of the nozzles.

7. The burner according to claim 1, characterized in that The annular side wall includes, from the outside to the inside, a coaxially arranged outer annular side wall, a middle annular side wall and an inner annular side wall, the outer annular side wall is connected to the front wall at one end close to the combustion end, a first notch is provided between the inner wall of the front wall and the end of the middle annular side wall close to the combustion end, 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 connected to the air inlet, a second notch is provided between the inner wall of the rear wall and the end of the inner annular side wall close to the combustion end, the inner annular side wall is connected to the front wall, 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 according to claim 7, characterized in that The front wall includes an outer front wall and an inner front wall from the outside to the inside. The outer front wall is connected to an end of the outer annular side wall close to the combustion end, and the inner front wall is connected to an end of the inner annular side wall close to the combustion end. 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 according to claim 7, characterized in that Also includes: an air duct connected to an end of the outer annular side wall away from the combustion end; A gas pipeline runs through the pipe wall of the air pipeline and is connected to an end of the gas nozzle away from the gas mixing chamber.

10. A cracking furnace, characterized in that: The cracking furnace is provided with a burner according to any one of claims 1 to 9.

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