Combination pulverized coal and oxidant burner

Abstract

The present application provides a kind of pulverized coal, oxidant combination formula burner, belong to coal chemical technology field, comprising: body and protective shell;Oxidant is transported by the oxidant flow channel in the body, pulverized coal is transported by pulverized coal flow channel, the body is internally provided with oxidant outlet pipe and pulverized coal outlet pipe, the protective shell is sleeved in the head of the body, the oxidant outlet pipe and the pulverized coal outlet pipe respectively from the head of the protective shell, the pulverized coal, oxidant combination formula burner provided by the present application, oxidant and pulverized coal are mixed outside the protective shell, can effectively prevent the backflow oxidation reaction of near burner, prolongs the trouble-free operation cycle of burner.

Description

A pulverized coal and oxidizer combined burner Technical Field

[0001] This invention relates to the field of coal chemical technology, specifically to a combined pulverized coal and oxidant burner. Background Technology

[0002] Coal gasification refers to the process of feeding appropriately treated coal (such as pulverized coal, coke particles, combustible powder, etc.) into a reactor, such as a gasifier, and converting it into gas (such as CO, H2, H2O, CO2, etc.) under specific temperature and pressure conditions within the coal gasification process, using an oxidant (air or oxygen and steam). The resulting syngas can be widely used in various chemical industries. In the coal gasification process, the burner is an indispensable and crucial component.

[0003] Existing burners, such as the process burner for a fluidized bed gasifier disclosed in Chinese patent document CN110003957A, have an oxidant injection port recessed inside the shell, and a pulverized coal injection port annular around the oxidant injection port. The oxidant and pulverized coal come into contact inside the shell and are then sprayed out together. This design is prone to near-orifice backflow oxidation reactions, causing burner damage and resulting in a short trouble-free operating cycle. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the nozzle of the burner is prone to backflow oxidation reaction, which causes the burner to be easily burned and damaged in the prior art, thereby providing a pulverized coal and oxidant combined burner.

[0005] To solve the above-mentioned technical problems, the present invention provides a pulverized coal and oxidizer combined burner, comprising:

[0006] The body has an oxidant flow channel and a pulverized coal flow channel. The head of the body has an outwardly extending oxidant outlet pipe and a pulverized coal outlet pipe. The oxidant outlet pipe is connected to the oxidant flow channel, and the pulverized coal outlet pipe is connected to the pulverized coal flow channel.

[0007] A protective shell is fitted over the head of the main body, and the oxidant outlet pipe and the pulverized coal outlet pipe extend into the protective shell and at least partially protrude from the head of the protective shell.

[0008] Optionally, the body includes an inner shell and an outer shell, the outer shell being concentrically fitted outside the inner shell, the oxidant flow channel being disposed in the inner shell, the pulverized coal flow channel being disposed in the outer shell, and the pulverized coal outlet pipe being disposed circumferentially around the oxidant outlet pipe.

[0009] Optionally, the oxidant outlet pipe is located at the center of the body, and there are at least three pulverized coal outlet pipes, with a plurality of pulverized coal outlet pipes evenly arranged around the oxidant outlet pipe.

[0010] Optionally, the protective shell has a cooling channel inside, the cooling channel comprising:

[0011] The inlet channel extends from the tail of the protective shell to the head of the protective shell;

[0012] The coiled flow channel is connected to the inlet flow channel. The coiled flow channel extends from the head of the protective shell toward the tail of the protective shell. The cooling medium enters the head of the protective shell from the inlet flow channel and then flows spirally along the coiled flow channel from the head to the tail of the protective shell.

[0013] Optionally, it further includes: a first mounting flange connected to the body, wherein the first mounting flange and the protective shell are spaced apart;

[0014] A cooling pipe is connected to the first mounting flange and communicates with the cooling channel of the protective shell. An expansion compensation structure is provided in the cooling pipe at the interval between the first mounting flange and the protective shell.

[0015] Optionally, the expansion compensation structure includes a coiled bend.

[0016] Optionally, it further includes: an external protective gas passage disposed on the first mounting flange, the external protective gas passage having an outlet facing the protective shell.

[0017] Optionally, the oxidant channel and the pulverized coal channel have a tapering section; the outlets of the oxidant outlet pipe and the pulverized coal outlet pipe have a flared structure.

[0018] Optionally, an oxidant inlet pipe is connected to the end of the main body, and a heat compensation device that cooperates with the oxidant inlet pipe is provided at the end of the inner shell.

[0019] Optionally, a second mounting flange is provided on the outer wall of the end of the body, and a third mounting flange is provided on the oxidant inlet pipe to cooperate with the second mounting flange for installation, and a sealing element is provided between the second mounting flange and the third mounting flange.

[0020] The technical solution of this invention has the following advantages:

[0021] 1. The pulverized coal and oxidant combined burner provided by the present invention delivers oxidant through an oxidant channel inside the main body and pulverized coal through a pulverized coal channel. An oxidant outlet pipe and a pulverized coal outlet pipe are provided at the head of the main body. A protective shell is fitted over the head of the main body. After the protective shell is fitted over the head of the main body, the oxidant outlet pipe and the pulverized coal outlet pipe extend from the head of the protective shell, respectively. The oxidant and pulverized coal are mixed outside the protective shell, which can effectively prevent backflow oxidation reaction near the burner and extend the trouble-free operation cycle of the burner.

[0022] 2. The pulverized coal and oxidant combined burner provided by the present invention has an outer shell concentrically fitted outside an inner shell, the cavity inside the inner shell forming an oxidant flow channel, the cavity between the outer shell and the inner shell forming a pulverized coal flow channel, and the pulverized coal outlet pipe being arranged circumferentially around the oxidant outlet pipe, so that the sprayed pulverized coal and oxidant come into contact and mix.

[0023] 3. The pulverized coal and oxidant combined burner provided by this invention has multiple pulverized coal outlet pipes evenly arranged around the oxidant outlet pipe, so that the pulverized coal and oxidant are sprayed coaxially and parallel, effectively controlling the mixing and combustion zone of pulverized coal and oxidant, ensuring full mixing for oxidation reaction while preventing oxidation reaction at close range with the furnace wall and thus preventing "wall burning"; when the high flow rate of pulverized coal causes severe wear to the pulverized coal outlet pipe, only the pulverized coal outlet pipe needs to be replaced, reducing costs.

[0024] 4. The pulverized coal and oxidizer combined burner provided by the present invention has a cooling channel inside the protective shell. The cooling medium is preferentially transported from the tail of the protective shell to the head of the protective shell through the inlet channel, and then flows spirally from the head to the tail of the protective shell through the coiled channel, so that the temperature rise of the most severe working part is preferentially limited, and the fault-free operation cycle of the burner is extended.

[0025] 5. The pulverized coal and oxidant combined burner provided by the present invention is mounted on the reactor via a first mounting flange on the main body. The first mounting flange and the protective shell are spaced apart to prevent equipment damage caused by the expansion difference between the main body and the protective shell after heating, thereby extending the trouble-free operation cycle of the burner. The cooling channel inside the protective shell is connected to the cooling pipe connected to the first mounting flange. The cooling medium is input from outside the reactor through the cooling pipe. An expansion compensation structure is provided between the first mounting flange and the protective shell in the cooling pipe, which can compensate for the expansion difference between the outer shell and the cooling channel, thereby extending the trouble-free operation cycle of the burner.

[0026] 6. The pulverized coal and oxidizer combined burner provided by the present invention has an expansion compensation structure with a coiled bend tube, which performs expansion compensation through the stretchability and compressibility of the coiled bend tube.

[0027] 7. The pulverized coal and oxidant combined burner provided by the present invention is further provided with an external protective gas channel on the first mounting flange. The burner surface extending into the reactor is purged by the outlet facing the protective shell, which can prevent pulverized coal or its combustion products from adhering to the surface. The airflow can also cool the burner surface, thereby protecting the burner surface extending into the reactor and extending the burner's trouble-free operation cycle.

[0028] 8. The pulverized coal and oxidant combined burner provided by the present invention has a tapering section in the oxidant flow channel and the pulverized coal flow channel to accelerate the oxidant and pulverized coal airflow. The flared structure at the outlet of the oxidant outlet pipe and the pulverized coal outlet pipe enables the airflow to be dispersed and dispersed, which is beneficial to the mixing of oxidant and pulverized coal. The tapering section and the flared structure work together to control the ejection velocity of oxidant and pulverized coal within the required range, so that the airflow swirl zone at the burner outlet end is far away from the burner front end, but not so far that it will cause wall burning.

[0029] 9. The pulverized coal and oxidizer combined burner provided by the present invention has an oxidizer inlet pipe connected to the end of the main body. The oxidizer inlet pipe is used to connect to the oxidizer input device. The end of the inner shell is provided with a heat compensation device that cooperates with the oxidizer inlet pipe, which can compensate for the expansion difference between the inner shell and the outer shell and extend the fault-free operation cycle of the burner.

[0030] 10. The pulverized coal and oxidizer combined burner provided by the present invention has a second mounting flange on the outer wall of the end of the main body. The oxidizer inlet pipe is installed on the main body through a third mounting flange that cooperates with the second mounting flange, which facilitates disassembly, assembly, inspection and maintenance. The gap between the second mounting flange and the third mounting flange is sealed by a sealing element provided between the second mounting flange and the third mounting flange to prevent oxidizer leakage. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 is a schematic diagram of one embodiment of the pulverized coal and oxidizer combined burner provided in this invention.

[0033] Figure 2 is a side view of Figure 1.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Body; 2. Oxidant flow channel; 3. Pulverized coal flow channel; 4. Oxidant outlet pipe; 5. Pulverized coal outlet pipe; 6. Protective shell; 7. Inner shell; 8. Outer shell; 9. Cooling channel; 10. Inlet flow channel; 11. Coiled flow channel; 12. First mounting flange; 13. Cooling pipe; 14. Coiled bend; 15. External protective gas channel; 16. Oxidant inlet pipe; 17. Thermal compensation device; 18. Pulverized coal inlet pipe; 19. Second mounting flange; 20. Third mounting flange; 21. Seal; 22. Protective layer; 23. Connector. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] This embodiment provides a pulverized coal and oxidant combined burner that can extend the fault-free operation cycle of the burner, used in fixed-bed coal gasification technology to deliver pulverized coal and oxidant into the reactor.

[0041] Figure 1 shows a specific embodiment of a pulverized coal and oxidizer combined burner provided in this example, comprising: a body 1 and a protective shell 6; the body 1 is provided with an oxidizer channel 2 and a pulverized coal channel 3, and the head of the body 1 has an outwardly extending oxidizer outlet pipe 4 and a pulverized coal outlet pipe 5, the oxidizer outlet pipe 4 being connected to the oxidizer channel 2 and the pulverized coal outlet pipe 5 being connected to the pulverized coal channel 3; the protective shell 6 is sleeved on the head of the body 1, and the oxidizer outlet pipe 4 and the pulverized coal outlet pipe 5 respectively extend into the protective shell 6, and at least partially extend out from the head of the protective shell 6.

[0042] In use, oxidant is transported through the oxidant channel 2 inside the main body 1, and pulverized coal is transported through the pulverized coal channel 3. The protective shell 6 is fitted over the head of the main body 1, so that the oxidant outlet pipe 4 and the pulverized coal outlet pipe 5, which are located at the head of the main body 1, extend from the head of the protective shell 6, respectively. The pulverized coal and oxidant combined burner provided by this invention effectively prevents backflow oxidation reactions near the burner and extends the burner's trouble-free operating cycle because the oxidant and pulverized coal are mixed outside the protective shell 6.

[0043] Specifically, the main body 1 is preferably made of a wear-resistant, corrosion-resistant, and temperature-resistant alloy material. The oxidant outlet pipe 4 and the pulverized coal outlet pipe 5 are preferably made of nickel-chromium-iron alloy and hardened to ensure strength, wear resistance, and overall durability under fixed-bed operating conditions. The protective shell 6 is cast from copper or a copper alloy with high thermal conductivity, protecting the head of the main body 1 from damage caused by the high temperature, oxidation, and abrasion of the reactor's internal operating conditions. At the contact point between the front end of the protective shell 6 and the high-temperature medium inside the reactor, a composite temperature-resistant and corrosion-resistant nickel alloy protective layer 22 is preferably welded to provide surface protection against high temperature, abrasion, and oxidation, ensuring the protective shell 6's durability under operating conditions. The protective shell 6 and the pulverized coal outlet pipe 5 are cast tightly together to ensure heat conduction between them and improve the operating conditions of the pulverized coal outlet pipe 5.

[0044] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, the body 1 includes an inner shell 7 and an outer shell 8. The outer shell 8 is concentrically fitted outside the inner shell 7. The oxidizer flow channel 2 is disposed in the inner shell 7, and the pulverized coal flow channel 3 is disposed in the outer shell 8. The pulverized coal outlet pipe 5 is arranged circumferentially around the oxidizer outlet pipe 4. In use, the cavity inside the inner shell 7 forms the oxidizer flow channel 2, the cavity between the outer shell 8 and the inner shell 7 forms the pulverized coal flow channel 3, and the pulverized coal outlet pipe 5 is arranged circumferentially around the oxidizer outlet pipe 4, so that the sprayed pulverized coal and oxidizer come into contact and mix.

[0045] As shown in Figure 2, in the pulverized coal and oxidant combined burner provided by the present invention, the oxidant outlet pipe 4 is located at the center of the body 1, and there are at least three pulverized coal outlet pipes 5, which are uniformly arranged around the oxidant outlet pipe 4. In use, the multiple pulverized coal outlet pipes 5 are uniformly arranged around the oxidant outlet pipe 4, allowing the pulverized coal and oxidant to be sprayed coaxially and parallel, effectively controlling the mixing and combustion zone of the pulverized coal and oxidant. This ensures thorough mixing for oxidation while preventing close-range oxidation reactions with the furnace wall, thus avoiding "wall burning." When the high-velocity pulverized coal causes severe wear on the pulverized coal outlet pipe 5, only the pulverized coal outlet pipe 5 needs to be replaced, reducing costs. Specifically, an anti-wear layer is provided on the inner wall of the pulverized coal outlet pipe 5. The anti-wear layer is preferably made of metal-ceramic material to effectively withstand the wear caused by the high-speed flow of pulverized coal and has good self-lubricating properties to reduce frictional resistance. Alternatively, as an alternative embodiment, the pulverized coal outlet pipe 5 can also be a ring structure arranged concentrically with the oxidant outlet pipe 4.

[0046] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, a cooling channel 9 is provided inside the protective shell 6. The cooling channel 9 includes: an inlet channel 10 extending from the tail to the head of the protective shell 6; and a coiled channel 11 connected to the inlet channel 10, extending from the head to the tail of the protective shell 6. The cooling medium enters the head of the protective shell 6 through the inlet channel 10 and then flows spirally from the head to the tail along the coiled channel 11. In use, the cooling medium is preferentially delivered from the tail to the head of the protective shell 6 through the inlet channel 10, and then flows spirally from the head to the tail through the coiled channel 11, so that the temperature rise of the most severe operating part is preferentially limited, thus extending the burner's trouble-free operation cycle. Alternatively, as an alternative implementation, the coiled flow channel 11 can be omitted. Instead, an annular cavity concentric with the body 1 is provided inside the protective shell 6. The cooling medium is delivered to the head of the protective shell 6 through the inlet flow channel 10, enters the annular cavity from the head of the protective shell 6, and is then output from the tail of the protective shell 6.

[0047] As shown in Figure 1, the pulverized coal and oxidizer combined burner provided by the present invention further includes: a first mounting flange 12 connected to the body 1, with a gap between the first mounting flange 12 and the protective shell 6; and a cooling pipe 13 connected to the first mounting flange 12, the cooling pipe 13 communicating with the cooling channel 9 of the protective shell 6, and an expansion compensation structure provided at the gap between the first mounting flange 12 and the protective shell 6. In use, the body 1 is mounted on the reactor via the first mounting flange 12. The gap between the first mounting flange 12 and the protective shell 6 prevents equipment damage caused by the expansion difference between the body 1 and the protective shell 6 after heating, thus extending the burner's trouble-free operating cycle. The cooling channel 9 inside the protective shell 6 communicates with the cooling pipe 13, which is connected to the first mounting flange 12. Cooling medium is input from outside the reactor through the cooling pipe 13. The expansion compensation structure between the first mounting flange 12 and the protective shell 6 compensates for the expansion difference between the outer shell 8 and the cooling channel 9, further extending the burner's trouble-free operating cycle. Specifically, the cooling pipe 13 is connected to the cooling channel 9 via a connector 23.

[0048] As shown in Figure 1, the expansion compensation structure in the pulverized coal and oxidizer combined burner provided by the present invention includes a coiled bend 14. During use, expansion compensation is achieved through the stretchability and compressibility of the coiled bend 14. Alternatively, as an alternative embodiment, the coiled bend 14 can be omitted, and expansion compensation can be achieved through other means, such as installing a corrugated pipe on the cooling pipe 13.

[0049] As shown in Figure 1, the pulverized coal and oxidizer combined burner provided by the present invention further includes an external protective gas channel 15, which is disposed on the first mounting flange 12. The external protective gas channel 15 has an outlet facing the protective shell 6. In use, the external protective gas channel 15 purges the burner surface extending into the reactor through the outlet facing the protective shell 6, preventing pulverized coal or its combustion products from adhering to the burner surface, and cooling the surface through the airflow, thereby protecting the burner surface extending into the reactor and extending the burner's trouble-free operation cycle. Specifically, the external protective gas is preferably an inert protective gas such as nitrogen or carbon dioxide.

[0050] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, the oxidizer channel 2 and the pulverized coal channel 3 have tapered sections; the outlets of the oxidizer outlet pipe 4 and the pulverized coal outlet pipe 5 have flared structures. In use, the tapered sections in the oxidizer channel 2 and the pulverized coal channel 3 accelerate the oxidizer and pulverized coal airflow, while the flared structures at the outlets of the oxidizer outlet pipe 4 and the pulverized coal outlet pipe 5 facilitate the dispersion of the airflow, which is beneficial for the mixing of the oxidizer and pulverized coal. The combination of the tapered sections and the flared structures controls the ejection velocity of the oxidizer and pulverized coal within the required range, ensuring that the airflow swirl zone at the burner outlet is far from the burner front end without being too far away and causing wall burns.

[0051] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, the end of the main body 1 is connected to an oxidizer inlet pipe 16, and the end of the inner shell 7 is provided with a heat compensation device 17 that cooperates with the oxidizer inlet pipe 16. In use, the end of the main body 1 is connected to the oxidizer inlet pipe 16, which is used to connect to an oxidizer input device. The heat compensation device 17 at the end of the inner shell 7, which cooperates with the oxidizer inlet pipe 16, can compensate for the expansion difference between the inner shell 7 and the outer shell 8, avoiding damage to the inner shell 7 and the outer shell 8 due to the compensation difference, and extending the burner's trouble-free operation cycle. Specifically, the pre-pressure applied to the inner shell 7 by the heat compensation device 17 enables a metal hard seal between the oxidizer outlet pipe 4 and the protective shell 6. The heat compensation device 17 can be a bellows or other device capable of compensating for the expansion difference between the inner shell 7 and the outer shell 8.

[0052] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, a pulverized coal inlet pipe 18 is provided on the outer shell 8, which is used to connect to a pulverized coal conveying device. Specifically, the pulverized coal is preferably conveyed by inert protective gases such as nitrogen and carbon dioxide, and the high-flow-rate inert protective gas is used to protect the burner tip from damage by high temperature and oxides.

[0053] As shown in Figure 1, in the pulverized coal and oxidizer combined burner provided by the present invention, a second mounting flange 19 is provided on the outer wall of the end of the main body 1, and a third mounting flange 20 is provided on the oxidizer inlet pipe 16 to cooperate with the second mounting flange 19. A sealing element 21 is provided between the second mounting flange 19 and the third mounting flange 20. In use, the oxidizer inlet pipe 16 is installed on the main body 1 by cooperating with the second mounting flange 19 through the third mounting flange 20, which facilitates disassembly, assembly, inspection and maintenance. The sealing element 21 seals the gap between the second mounting flange 19 and the third mounting flange 20 to prevent oxidizer leakage. Specifically, the second mounting flange 19 and the third mounting flange 20 are flange-connected by fasteners.

[0054] How to use

[0055] As shown in Figure 1, the pulverized coal and oxidant combined burner provided in this embodiment, during use, delivers oxidant through the oxidant channel 2 inside the body 1 and pulverized coal through the pulverized coal channel 3. The oxidant outlet pipe 4 and the pulverized coal outlet pipe 5 have a structure with a gradually narrowing inlet, a small central circular pipe, and a gradually widening outlet, ensuring that the sprayed oxidant and pulverized coal reach the required flow velocity. They are then sprayed out from the oxidant outlet pipe 4 and the pulverized coal outlet pipe 5 extending from the protective shell 6. The oxidant and pulverized coal mix outside the protective shell 6, keeping the airflow swirl zone away from the burner, effectively preventing backflow oxidation reactions near the burner and extending the burner's trouble-free operating cycle. The pulverized coal and oxidant combined burner provided by this invention overcomes the problem in the prior art where backflow oxidation reactions easily form at the burner's injection port, causing burner burnout and damage.

[0056] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A combined pulverized coal and oxidizer burner, characterized in that, include: The body (1) is provided with an oxidant channel (2) and a pulverized coal channel (3) inside the body (1). The head of the body (1) has an outwardly extending oxidant outlet pipe (4) and a pulverized coal outlet pipe (5). The oxidant outlet pipe (4) is connected to the oxidant channel (2), and the pulverized coal outlet pipe (5) is connected to the pulverized coal channel (3). A protective shell (6) is fitted on the head of the body (1). The oxidant outlet pipe (4) and the pulverized coal outlet pipe (5) extend into the protective shell (6) respectively, and at least part of them extend out from the head of the protective shell (6).

2. The pulverized coal and oxidizer combined burner according to claim 1, characterized in that, The main body (1) includes an inner shell (7) and an outer shell (8). The outer shell (8) is concentrically fitted outside the inner shell (7). The oxidant flow channel (2) is disposed in the inner shell (7). The pulverized coal flow channel (3) is disposed in the outer shell (8). The pulverized coal outlet pipe (5) is disposed around the circumference of the oxidant outlet pipe (4).

3. The pulverized coal and oxidizer combined burner according to claim 2, characterized in that, The oxidant outlet pipe (4) is located at the center of the body (1), and there are at least three pulverized coal outlet pipes (5), with multiple pulverized coal outlet pipes (5) evenly arranged around the oxidant outlet pipe (4).

4. The pulverized coal and oxidizer combined burner according to claim 2, characterized in that, The protective shell (6) is provided with a cooling channel (9) inside. The cooling channel (9) includes: an inlet channel (10) that extends from the tail of the protective shell (6) to the head of the protective shell (6); and a coiled channel (11) that communicates with the inlet channel (10). The coiled channel (11) extends from the head of the protective shell (6) toward the tail of the protective shell (6). The cooling medium enters the head of the protective shell (6) from the inlet channel (10) and then flows spirally from the head of the protective shell (6) toward the tail along the coiled channel (11).

5. The pulverized coal and oxidizer combined burner according to claim 4, characterized in that, Also includes: A first mounting flange (12) is connected to the body (1), and there is a gap between the first mounting flange (12) and the protective shell (6); a cooling pipe (13) is connected to the first mounting flange (12), and the cooling pipe (13) communicates with the cooling channel (9) of the protective shell (6), and the cooling pipe (13) is provided with an expansion compensation structure at the gap between the first mounting flange (12) and the protective shell (6).

6. The pulverized coal and oxidizer combined burner according to claim 5, characterized in that, The expansion compensation structure includes: a coiled bend (14).

7. The pulverized coal and oxidizer combined burner according to claim 5, characterized in that, It also includes an external protective gas channel (15) disposed on the first mounting flange (12), the external protective gas channel (15) having an outlet facing the protective shell (6).

8. The pulverized coal and oxidizer combined burner according to any one of claims 1-7, characterized in that, The oxidant channel (2) and the pulverized coal channel (3) have tapered sections; the outlets of the oxidant outlet pipe (4) and the pulverized coal outlet pipe (5) are flared structures.

9. The pulverized coal and oxidizer combined burner according to any one of claims 2-7, characterized in that, The end of the main body (1) is connected to an oxidant inlet pipe (16), and the end of the inner shell (7) is provided with a heat compensation device (17) that cooperates with the oxidant inlet pipe (16).

10. The pulverized coal and oxidizer combined burner according to claim 9, characterized in that, A second mounting flange (19) is provided on the outer wall of the end of the main body (1), and a third mounting flange (20) is provided on the oxidant inlet pipe (16) to cooperate with the second mounting flange (19). A sealing element (21) is provided between the second mounting flange (19) and the third mounting flange (20).

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