A belt type calcination burner using a semi-premix structure

Abstract

A belt roasting burner with semi-premix structure relates to the field of burners. The belt roasting burner with semi-premix structure comprises a burner brick provided with a combustion chamber, a premix pipe penetrating into the combustion chamber, an air connecting pipe communicating with the premix pipe and a gas pipe arranged in the air connecting pipe, the gas pipe is connected with a burner core body, the burner core body comprises a center pipe connected with the gas pipe and a plurality of branch nozzles arranged in a circumferential direction and connected with the outer wall of the center pipe, and the end of the center pipe away from the gas pipe is closed; the gas pipe is provided with an ignition electrode extending into the combustion chamber, the air connecting pipe and the gas pipe are respectively connected with an air inlet and a gas inlet, the gas inlet is connected with a plurality of gas branch pipes arranged in a circumferential direction of the air connecting pipe, and the gas branch pipes extend into the combustion chamber. The belt roasting burner with semi-premix structure can significantly reduce the NOx emission generated in the high-temperature combustion process, reduce the local high-temperature area in the combustion chamber and improve the temperature uniformity in the combustion chamber. X ​

Description

Technical Field

[0001] This application relates to the field of burners, and more specifically, to a belt roasting burner employing a semi-premixed structure. Background Technology

[0002] As a core component of the pelletizing process, the combustion system of a belt calciner directly impacts production efficiency, energy consumption, and environmental performance through its design and combustion technology selection. Existing belt calciner burners typically employ staged combustion technology, separating the primary air-fuel mixture into two stages and mixing them using a swirling and direct injection method. This achieves uniform and complete combustion, reduces local flame temperature and oxygen concentration in the combustion zone, and shortens the residence time of the mixed gas in the high-temperature zone, thereby reducing NOx emissions. X Emissions are reduced, but because the primary air accounts for only about 10% of the burner's output, and the secondary air is high-temperature gas and in large excess, the combustion chamber is a strongly oxidizing atmosphere during combustion, resulting in NO emissions. X The emission reduction effect is limited and it is difficult to meet the ultra-low emission technical targets stipulated by national and local governments.

[0003] Therefore, there is a need for a method that can effectively reduce NO at high temperatures. X A burner that emits emissions and improves flame stability. Utility Model Content

[0004] The purpose of this application is to provide a belt-type roasting burner with a semi-premixed structure, which can significantly reduce NO generated during high-temperature combustion. X Emissions are reduced, localized high-temperature zones within the combustion chamber are decreased, and temperature uniformity within the combustion chamber is improved.

[0005] This application is implemented as follows:

[0006] This application provides a belt-type roasting burner with a semi-premixed structure, including a burner brick with a combustion chamber and a connecting flange connected to the burner brick. One side of the connecting flange is connected to a premixing pipe extending into the combustion chamber, and the other side is connected to an air connecting pipe communicating with the premixing pipe. One end of the premixing pipe extending into the combustion chamber is connected to an air distribution plate. A gas pipe is provided inside the air connecting pipe. One end of the gas pipe extends into the premixing pipe and is connected to a burner core, while the other end extends out of the air connecting pipe and is connected to a blind flange with an inspection hole. The burner core includes a central pipe connected to the gas pipe and multiple branch nozzles arranged circumferentially and connected to the outer wall of the central pipe. The end of the central pipe away from the gas pipe is closed. An ignition electrode extending into the combustion chamber is provided inside the gas pipe. The air connecting pipe and the gas pipe are respectively connected to an air inlet and a gas inlet. The gas inlet is connected to multiple gas branch pipes arranged circumferentially and extending into the combustion chamber.

[0007] In some alternative implementations, the outer wall of the branch nozzle has multiple through holes.

[0008] In some optional implementations, the air distribution plate has multiple rings of air distribution holes arranged at intervals from the inside to the outside. Each ring includes multiple air distribution holes arranged at intervals along the circumference of the air distribution plate. The air distribution holes of adjacent rings are staggered along the circumference, and the axis of each air distribution hole is inclined at an angle along the circumference of the air distribution plate.

[0009] In some alternative implementations, the ignition electrode includes a ceramic sleeve with one end connected to the blind flange of the access hole and an electrode wire fixed inside the ceramic sleeve, the electrode wire passing through the air distribution plate and extending into the combustion chamber.

[0010] In some alternative implementations, an annular secondary gas pipe is fitted around the outside of the air connection pipe, and each gas branch pipe is connected to the secondary gas pipe. The secondary gas pipe is connected to the gas inlet through a secondary gas delivery pipe.

[0011] In some alternative implementations, the burner brick has a viewing hole that communicates with the combustion chamber.

[0012] In some alternative implementations, the viewing port is connected to a flame detection tube.

[0013] In some alternative implementations, the inner diameter of the peephole gradually increases as it approaches the combustion chamber.

[0014] In some alternative implementations, the burner brick is provided with mounting holes for the premixing tube to extend into the combustion chamber, and the inner diameter of the mounting holes gradually increases as they approach the combustion chamber.

[0015] In some alternative implementations, the mounting hole is provided with a flared opening at the connection with the combustion chamber.

[0016] The beneficial effects of this application are as follows: The belt roasting burner with a semi-premixed structure provided by this application includes a burner brick with a combustion chamber inside and a connecting flange connected to the burner brick. One side of the connecting flange is connected to a premixing pipe extending into the combustion chamber, and the other side is connected to an air connecting pipe that communicates with the premixing pipe. One end of the premixing pipe extending into the combustion chamber is connected to an air distribution plate. A gas pipe is provided inside the air connecting pipe. One end of the gas pipe extends into the premixing pipe and is connected to the burner core. The other end extends out of the air connecting pipe and is connected to a blind flange with an inspection hole. The burner core includes a central pipe connected to the gas pipe and multiple branch nozzles arranged circumferentially and connected to the outer wall of the central pipe. The end of the central pipe away from the gas pipe is closed. An ignition electrode extending into the combustion chamber is provided inside the gas pipe. The air connecting pipe and the gas pipe are respectively connected to an air inlet and a gas inlet. The gas inlet is connected to multiple gas branch pipes arranged circumferentially and at intervals along the air connecting pipe. The gas branch pipes extend into the combustion chamber. The belt roasting burner with a semi-premixed structure provided in this application uses a semi-premixed design to mix primary combustion gas and primary air in a premixing pipe through branch nozzles and air connection pipes. The mixture is then sprayed out through an air distribution plate and mixed with secondary combustion gas introduced through a gas branch pipe in the combustion chamber. This design achieves multiple effects of premixed combustion, staged combustion, and high-speed flue gas entrainment, thereby significantly reducing NO produced during high-temperature combustion. X Emissions are reduced, localized high-temperature zones within the combustion chamber are decreased, and temperature uniformity within the combustion chamber is improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional view of a belt roasting burner with a semi-premixed structure provided in an embodiment of this application.

[0019] Figure 2 A partial cross-sectional view of a belt roasting burner with a semi-premixed structure provided in an embodiment of this application;

[0020] Figure 3 This is a partial cross-sectional view of a belt-type roasting burner with a semi-premixed structure, omitting the burner bricks, provided in an embodiment of this application.

[0021] In the diagram: 100, burner brick; 110, combustion chamber; 120, connecting flange; 130, premixing pipe; 140, air connection pipe; 141, air inlet; 150, air distribution plate; 160, gas pipe; 161, gas inlet; 162, sealing flange; 170, burner core; 171, central tube; 172, branch nozzle; 180, inspection hole blind flange; 190, ignition electrode; 191, ceramic sleeve; 192, electrode wire; 200, gas branch pipe; 210, secondary gas pipe; 220, secondary gas delivery pipe; 230, inspection hole; 240, flame detection tube; 250, mounting hole; 260, bell mouth. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of this application, 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, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] The features and performance of the semi-premixed belt roasting burner of this application are further described in detail below with reference to embodiments.

[0030] like Figure 1 , Figure 2 and Figure 3As shown, this application provides a belt roasting burner with a semi-premixed structure, including a burner brick 100 with a combustion chamber 110 inside and a connecting flange 120 connected to the burner brick 100. A premixed pipe 130 is connected to one side of the connecting flange 120, passing through a mounting hole 250 on the burner brick 100 and extending into the combustion chamber 110. An air connecting pipe 140 is connected to the other side. The inner diameter of the mounting hole 250 gradually increases as it approaches the combustion chamber 110. A flared opening 260 is provided at the connection between the mounting hole 250 and the combustion chamber 110. The air connecting pipe 140 communicates with the premixed pipe 130. One end of the premixed pipe 130 extending into the combustion chamber 110 is connected to an air distribution plate 150. A gas pipe 160 is located inside the air connecting pipe 140. One end extends into the premixing pipe 130 and is connected to the burner core 170 by threads. The other end extends out of the air connection pipe 140 and is connected to the inspection hole blind plate 180. The bottom of the air connection pipe 140 and the top of the gas pipe 160 are respectively connected to the air inlet 141 and the gas inlet 161. The gas pipe 160 is fixedly fitted with a sealing flange 162 that connects and seals the end of the air connection pipe 140 away from the connecting flange 120. The burner core 170 includes a central pipe 171 connected to the gas pipe 160 by threads and three branch nozzles 172 arranged circumferentially and connected to the outer wall of the central pipe 171. Each branch nozzle 172 has 100 through holes arranged at intervals on its outer wall. The end of the central pipe 171 away from the gas pipe 160 is closed.

[0031] An ignition electrode 190 is installed inside the gas pipe 160, extending through the air distribution plate 150 and into the combustion chamber 110. The ignition electrode 190 includes a ceramic sleeve 191 with one end connected to the blind flange 180 of the inspection hole and an electrode wire 192 fixed inside the ceramic sleeve 191. The electrode wire 192 extends through the air distribution plate 150 and into the combustion chamber 110. The gas inlet 161 is connected to four gas branch pipes 200 arranged circumferentially along the air connection pipe 140. A ring-shaped secondary gas pipe 210 is sleeved on the outside of the air connection pipe 140. One end of each gas branch pipe 200 is connected to the secondary gas pipe 210, and the other end extends through the burner brick 100 into the combustion chamber 110. The secondary gas pipe 210 is connected to the gas inlet 161 through a secondary gas delivery pipe 220.

[0032] The air distribution plate 150 has three concentric rings of air distribution holes arranged at intervals from the inside to the outside. Each ring includes six air distribution holes arranged at intervals along the circumference of the air distribution plate 150. The air distribution holes in adjacent rings are staggered circumferentially. The axis of each air distribution hole is inclined at a 30-degree angle along the circumference of the air distribution plate 150. The burner brick 100 has an inspection hole 230 communicating with the combustion chamber 110. The inspection hole 230 is connected to a flame detection tube 240. The inner diameter of the inspection hole 230 gradually increases as it approaches the combustion chamber 110.

[0033] The belt-type calcining burner with a semi-premixed structure provided in this application uses a connecting flange 120 connected to the burner brick 100 to connect a premixed pipe 130 and an air connecting pipe 140 extending into the combustion chamber 110. A gas pipe 160 is provided inside the air connecting pipe 140, with one end extending into the premixed pipe 130 and connected to the burner core 170. The other end of the gas pipe 160 extends out of the air connecting pipe 140 and is connected to a blind flange 180 with a maintenance hole. A sealing flange 162 is fixedly fitted onto the gas pipe 160 to seal the air connecting pipe 140. The burner core 170 includes a central pipe 171 connected to the gas pipe 160 by threads and three branch nozzles 172 arranged circumferentially and connected to the outer wall of the central pipe 171. Each branch nozzle 172... The outer wall has 100 spaced through holes, which allow air to enter the premixing pipe 130 through the air inlet 141 and the air connecting pipe 140, and allow coal gas to enter the central pipe 171 through the coal gas inlet 161 and the coal gas pipe 160, and then be sprayed out from each branch nozzle 172 into the premixing pipe 130. Thus, the primary air and primary coal gas are mixed and the primary air-fuel mixture enters the combustion chamber 110 from the air distribution plate 150 at the end of the premixing pipe 130 and is ignited by the ignition electrode 190. Since the primary air-fuel mixture is premixed through the premixing pipe 130, a stable flame root will be formed at the outlet of the premixing pipe 130, which greatly enhances the stability of the root flame and significantly improves the stability of the burner ignition under cold conditions, realizing stable ignition of the gas-air mixture in a large space.

[0034] Simultaneously, secondary gas enters the secondary gas delivery pipe 220 through the gas inlet 161 and then enters the secondary gas pipe 210. It is then fed into the combustion chamber 110 through the secondary gas pipes 210 spaced circumferentially along the air connection pipe 140. Through a semi-premixed structure design, the primary combustion gas and primary air are mixed in the premixing pipe 130, then sprayed out at high speed through the air distribution plate 150. This mixture then mixes and burns with the high-speed injected secondary combustion gas in the combustion chamber 110, forming a stable secondary combustion zone. Through the combined effects of premixed combustion, staged combustion, and high-speed flue gas entrainment, the NO production during high-temperature combustion can be significantly reduced. X Emissions are reduced, local high-temperature zones within the combustion chamber 110 are decreased, and temperature uniformity within the combustion chamber 110 is improved.

[0035] Each branch nozzle 172 has 100 spaced through holes on its outer wall, which allow the gas to disperse through the through holes when it enters the premixing pipe 130 through the branch nozzle 172, thereby improving the mixing degree of the gas and air in the premixing pipe 130. The air distribution plate 150 has three rings of air distribution holes arranged at intervals from the inside to the outside. Each ring includes a set of air distribution holes arranged at intervals along the circumference of the air distribution plate 150. The air distribution holes of adjacent rings are staggered along the circumference. The axis of each air distribution hole is inclined at a 45-degree angle along the circumference of the air distribution plate 150, which allows the premixed gas passing through the air distribution plate 150 to simultaneously form a swirling flow along the circumference of the air distribution plate 150 when it passes through each air distribution hole, thereby improving the premixing effect.

[0036] The burner brick 100 has an inspection hole 230 that communicates with the combustion chamber 110. The inspection hole 230 is connected to a flame detection tube 240. The inner diameter of the inspection hole 230 gradually increases as it approaches the combustion chamber 110, which makes it convenient for operators to use the flame detection tube 240 to monitor the combustion in the combustion chamber 110 through the inspection hole 230.

[0037] In other alternative embodiments, the air distribution plate may also be selected from other existing air distribution plate structures.

[0038] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A belt-type roasting burner employing a semi-premixed structure, comprising a burner brick with an internal combustion chamber and a connecting flange connected to the burner brick, characterized in that, One side of the connecting flange is connected to a premixing pipe extending into the combustion chamber, and the other side is connected to an air connection pipe communicating with the premixing pipe. One end of the premixing pipe extending into the combustion chamber is connected to an air distribution plate. A gas pipe is provided inside the air connection pipe. One end of the gas pipe extends into the premixing pipe and is connected to a burner core. The other end extends out of the air connection pipe and is connected to a blind flange with an inspection hole. The burner core includes a central pipe connected to the gas pipe and multiple branch nozzles arranged circumferentially and connected to the outer wall of the central pipe. The end of the central pipe away from the gas pipe is closed. An ignition electrode is provided inside the gas pipe and extends into the combustion chamber. The air connection pipe and the gas pipe are respectively connected to an air inlet and a gas inlet. The gas inlet is connected to multiple gas branch pipes arranged circumferentially and at intervals along the air connection pipe. The gas branch pipes extend into the combustion chamber.

2. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, The outer wall of the branch nozzle has multiple through holes.

3. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, The air distribution plate has multiple rings of air distribution holes arranged at intervals from the inside to the outside. Each ring includes multiple air distribution holes arranged at intervals along the circumference of the air distribution plate. The air distribution holes of adjacent rings are staggered along the circumference, and the axis of each air distribution hole is inclined at an angle along the circumference of the air distribution plate.

4. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, The ignition electrode includes a ceramic sleeve with one end connected to the blind flange of the inspection hole and an electrode wire fixed inside the ceramic sleeve. The electrode wire passes through the air distribution plate and extends into the combustion chamber.

5. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, An annular secondary gas pipe is sleeved on the outside of the air connection pipe, and each of the gas branch pipes is connected to the secondary gas pipe. The secondary gas pipe is connected to the gas inlet through a secondary gas delivery pipe.

6. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, The burner brick has a viewing hole that communicates with the combustion chamber.

7. The belt-type roasting burner with a semi-premixed structure according to claim 6, characterized in that, The viewing hole is connected to a flame detection tube.

8. The belt-type roasting burner with a semi-premixed structure according to claim 6, characterized in that, The inner diameter of the viewing hole gradually increases as it approaches the combustion chamber.

9. The belt-type roasting burner with a semi-premixed structure according to claim 1, characterized in that, The burner brick has an installation hole for the premixing tube to extend into the combustion chamber, and the inner diameter of the installation hole gradually increases as it approaches the combustion chamber.

10. The belt-type roasting burner with a semi-premixed structure according to claim 9, characterized in that, The mounting hole is provided with a flared opening at the connection between it and the combustion chamber.

Images