Pellet belt type roasting burner with adjustable smoke backflow structure
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WISCODRI WUGANG ENG
- Filing Date
- 2025-06-23
- Publication Date
- 2026-05-26
AI Technical Summary
Existing burners exhibit high NOx emissions under conditions of high blast furnace temperature and high excess air, poor cold-state flame stability, low control ratio, and flame instability due to mixed combustion within the combustion chamber.
The design incorporates a pelletized belt roasting burner with an adjustable flue gas recirculation structure. By setting up a Laval channel and recirculation chamber, combined with an adjustment plate and adjustment device, flue gas recirculation and flow regulation are achieved, reducing NOx emissions and improving flame stability and control ratio.
It effectively reduces local high-temperature zones in the furnace, lowers NOx emissions, improves flame stability and hot/cold state adjustment ratio, and ensures the stability and reliability of the burner across the entire power range.
Smart Images
Figure CN224284616U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of burners, and more specifically, to a pellet belt roasting burner with an adjustable flue gas recirculation structure. Background Technology
[0002] The combustion system is the core of the entire belt roaster system, including the burner body, gas supply system, combustion air system, ignition system, and safety detection system. Compared with conventional burners, belt roaster burners require 90% of the furnace process gas to be used as combustion air, with the burner's own fresh air supply accounting for only 10%. This places higher demands on the burner's structural design, stability during cold-to-hot operation, and adaptability to the roasting process.
[0003] There are generally two approaches to burner structural design: one is to use an air-fuel dual-swirl combustion structure, where primary air and fuel gas are introduced into the burner through independent channels, and then ejected from the burner outlet after high-speed swirling using swirl vanes at the burner head. The other approach is to stage the fuel gas based on the air-fuel swirl structure, separating it into primary and secondary fuel gas through two independent intake channels. After high-speed swirling at the burner head, the fuel gas enters the combustion chamber for combustion.
[0004] Both types of burners mentioned above achieve stable combustion through enhanced mixing, under conditions of high blast furnace temperature and high excess air, NO X Emissions are easily generated, and since the burner bricks are not equipped with a combustion section, the mixed combustion occurs entirely within the combustion chamber space. Under cold start-up conditions, there are problems such as poor flame stability and low adjustment ratio.
[0005] Therefore, there is a need for a method that can improve cold flame stability, increase burner control ratio, and reduce high-temperature NO. X Burners that discharge pollutants and improve the uniformity of furnace temperature. Utility Model Content
[0006] The purpose of this application is to provide a pellet belt roasting burner with an adjustable flue gas recirculation structure, which can reduce the local high temperature zone in the furnace to lower NO levels. X Emissions are reduced to achieve flue gas recirculation flow regulation and control, improve flame stability, and increase the burner's hot and cold state regulation ratio.
[0007] This application is implemented as follows:
[0008] This application provides a pelletized belt roasting burner with an adjustable flue gas recirculation structure, including a burner brick with a Laval channel and a recirculation chamber, and a connecting flange connected to the burner brick. The two ends of the Laval channel are respectively connected to the recirculation chamber and the combustion chamber. One end of the connecting flange is connected to a burner core that extends through the recirculation chamber into one end of the Laval channel, and the other end is connected to an air pipe communicating with the burner core. The air pipe has a gas pipe extending into the burner core at one end, and the other end of the gas pipe extends out of the air pipe and is connected to a blind flange with an inspection hole. The air pipe and the gas pipe are respectively connected to an air inlet and a gas inlet. The burner brick also has multiple recirculation channels communicating with the recirculation chamber and the combustion chamber. The end of the burner brick away from the combustion chamber has an ignition pipe communicating with the recirculation chamber. An adjusting plate and an adjusting device for driving the adjusting plate to move axially along the burner core are fitted on the burner core. When the adjusting plate moves axially along the burner core, the cross-sectional area of the connection between the recirculation chamber and the Laval channel is adjusted.
[0009] In some alternative implementations, the regulating device includes multiple rods with one end connected to the regulating plate and the other end of the rods sliding through the burner brick and the connecting flange.
[0010] In some alternative implementations, the adjusting device further includes adjusting cylinders that are connected one-to-one with the connecting rods, the adjusting cylinders being used to drive the corresponding connecting rods to move axially along the burner core body.
[0011] In some alternative implementations, a mixing disc is connected to the end of the burner core away from the connecting flange.
[0012] In some alternative implementations, the burner brick is further provided with a sight tube communicating with the reflux chamber, which is provided with a sighting channel communicating with the combustion chamber, and the sight tube is aligned with the sighting channel.
[0013] In some alternative implementations, the inner diameter of the viewing channel gradually increases as it approaches the combustion chamber.
[0014] In some alternative implementations, the burner brick is also provided with a flame monitoring tube that connects to the reflux chamber.
[0015] In some alternative implementations, the Laval channel includes a contraction section, a throat, and an expansion section connected in sequence, with the contraction section and the expansion section connecting the return chamber and the combustion chamber, respectively, and the burner core extending into the contraction section.
[0016] In some alternative implementations, multiple return channels are arranged at circumferential intervals along the Laval channel.
[0017] In some alternative implementations, the air inlet is connected to the bottom of the air pipe, and the gas inlet is connected to the top of the gas pipe.
[0018] The beneficial effects of this application are as follows: The pellet belt roasting burner with adjustable flue gas recirculation structure provided in this application, by setting up Laval channels connecting the recirculation chamber and the combustion chamber at both ends respectively, and multiple recirculation channels connecting the recirculation chamber and the combustion chamber, and extending the burner core into one end of the Laval channel, can realize the recirculation of flue gas in the combustion chamber. Through the dilution effect of flue gas on the combustion air, it can effectively reduce the local high temperature zone in the furnace and reduce NO. X The system also includes an adjustment plate that adjusts the cross-sectional area of the connection between the flue gas return chamber and the Laval channel as the burner core moves axially. This allows for online adjustment and control of the flue gas return flow, improving flame stability while increasing the burner's hot and cold state adjustment ratio. Attached Figure Description
[0019] 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.
[0020] Figure 1 A cross-sectional schematic diagram of a pellet belt roasting burner with an adjustable flue gas recirculation structure provided in an embodiment of this application;
[0021] Figure 2 A partial cross-sectional view of a pellet belt roasting burner with an adjustable flue gas recirculation structure provided in an embodiment of this application;
[0022] Figure 3 A partial cross-sectional view of the pellet belt roasting burner with adjustable flue gas recirculation structure provided in the embodiments of this application, omitting the burner bricks;
[0023] Figure 4 A cross-sectional view of a pellet belt roasting burner with an adjustable flue gas recirculation structure, provided in another embodiment of this application.
[0024] In the diagram: 100, burner brick; 110, Laval channel; 111, contraction section; 112, throat; 113, expansion section; 120, reflux chamber; 130, connecting flange; 140, burner core; 141, mixing plate; 150, air pipe; 151, air inlet; 160, gas pipe; 161, gas inlet; 162, sealing flange; 170, blind flange for inspection hole; 180, reflux channel; 190, ignition tube; 200, combustion chamber; 210, regulating plate; 220, connecting rod; 230, regulating cylinder; 240, inspection tube; 241, inspection channel; 250, flame monitoring tube; 300, secondary air inlet. Detailed Implementation
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] The features and performance of the pellet belt roasting burner with adjustable flue gas recirculation structure of this application are further described in detail below with reference to embodiments.
[0033] like Figure 1 , Figure 2 and Figure 3 As shown, this application provides a pellet belt roasting burner with an adjustable flue gas recirculation structure, including a burner brick 100 with a Laval channel 110 and a recirculation chamber 120, and a connecting flange 130 connected to the burner brick 100. The Laval channel 110 includes a contraction section 111, a throat 112, and an expansion section 113 connected in sequence. The contraction section 111 and the expansion section 113 are respectively connected to the recirculation chamber 120 and the combustion chamber 200. The connecting flange... One end of the burner core 130 is connected to a burner core 140 that extends through the return chamber 120 into the contraction section 111, and the other end is connected to an air pipe 150 communicating with the burner core 140. One end of the burner core 140 extending into the contraction section 111 is connected to a mixing plate 141, which has spaced mixing holes. The air pipe 150 contains a gas pipe 160, one end of which extends into the burner core 140, and the other end of the gas pipe 160 extends out of the air pipe 111. 50 is connected to a blind flange 170 with an inspection hole. Air inlet 151 and gas inlet 161 are connected to the bottom of air pipe 150 and the top of gas pipe 160, respectively. A sealing flange 162 is fixedly fitted onto gas pipe 160. The sealing flange 162 is used to connect to and seal the end of air pipe 150 away from connecting flange 130. Burner brick 100 is also provided with eight return channels 180 connecting return chamber 120 and combustion chamber 200. The eight return channels 180 are along... The Laval channels 110 are arranged circumferentially. The burner brick 100 is provided with an ignition tube 190 that connects to the return chamber 120 at the end away from the combustion chamber 200. The burner brick 100 is also provided with a sight tube 240 and a flame monitoring tube 250 that connect to the return chamber 120. The return chamber 120 is provided with a sight channel 241 that connects to the combustion chamber 200. The sight tube 240 is aligned with the sight channel 241. The inner diameter of the sight channel 241 gradually increases as it approaches the combustion chamber 200.
[0034] An adjusting plate 210 and an adjusting device for driving the adjusting plate 210 to move axially along the burner core 140 are fitted onto the burner core 140. When the adjusting plate 210 moves axially along the burner core 140, it adjusts the cross-sectional area of the connection between the return chamber 120 and the Laval channel 110. The adjusting device includes four connecting rods 220, one end of which is connected to the adjusting plate 210, and the other end of the connecting rods 220 slides through the burner brick 100 and the connecting flange 130. In this embodiment, a secondary air inlet 300 is provided at the top of the combustion chamber 200.
[0035] The pellet belt roasting burner with adjustable flue gas recirculation structure provided in this application embodiment is equipped with a burner brick 100 having a Laval channel 110 and a recirculation chamber 120, and a connecting flange 130 connected to the burner brick 100. The connecting flange 130 is connected to a burner core 140 that extends through the recirculation chamber 120 and into the contraction section 111 of the Laval channel 110. The contraction section 111 and the expansion section 113 of the Laval channel 110 are respectively connected to the recirculation chamber 120 and the combustion chamber 200. This allows secondary air to be drawn into the combustion chamber 200 from the secondary air inlet 300 and mixed and burned secondaryally with the unburned flame ejected by the pellet belt roasting burner with adjustable flue gas recirculation structure in the combustion chamber 200. The fully combusted and mixed high-temperature flue gas is sent into the roasting chamber from the outlet of the combustion chamber 200. Simultaneously, air and gas are introduced into the burner core 140 through air inlet 151 and gas inlet 161 respectively, via air pipe 150 and gas pipe 160, to mix and form an air-gas mixture. This air-gas mixture is then ejected through mixing plate 141 to the contraction section 111 of Laval channel 110, creating a negative pressure zone in the contraction section 111. The burner brick 100 has eight return channels 180 connecting the return chamber 120 and the combustion chamber 200. These eight return channels 180 are arranged circumferentially along the Laval channel 110, allowing the flue gas in the combustion chamber 200 to enter the return chamber 120 through the return channels 180 and then mix with the air-gas mixture in the Laval channel 110 for combustion. This mixing effect of the return flue gas reduces the oxygen content in the flue gas, lowers the temperature of the high-temperature flame zone, and reduces NO₂ levels. X Generation was effectively suppressed.
[0036] An adjusting plate 210 and an adjusting device for driving the adjusting plate 210 to move axially along the burner core 140 are fitted onto the burner core 140. The adjusting device includes four connecting rods 220, one end of which is connected to the adjusting plate 210. The other end of the connecting rods 220 slides through the burner brick 100 and the connecting flange 130. The operator can pull the connecting rods 220 to move the adjusting plate 210 axially along the burner core 140 to adjust the cross-sectional area at the connection between the return chamber 120 and the Laval channel 110. Thus, the flow rate of the return flue gas flowing from the return chamber 120 into the Laval channel 110 is controlled by the blocking effect of the adjusting plate 210. When the adjusting plate 210 moves towards the combustion chamber 200, the return cross-sectional area is reduced, and the flue gas return flow rate decreases accordingly. Conversely, when the adjusting plate 210 moves away from the combustion chamber 200, the return cross-sectional area increases, and the flue gas return flow rate increases accordingly. By effectively controlling the return flue gas flow rate, NO in the combustion chamber 200 can be adjusted. X While maintaining emission levels, the system balances technical parameters such as burner cold ignition stability, control ratio, and flame length across the entire power range to ensure that the burner achieves ultra-low NO while meeting process requirements. X It can discharge gases and establish an effective negative pressure environment within the burner brick 100 even under low load conditions, thereby achieving stable combustion of the burner and reliable ignition and flame monitoring across the entire power range of the burner.
[0037] The burner brick 100 is also equipped with a sight tube 240 and a flame monitoring tube 250 that connect to the return chamber 120. The return chamber 120 is equipped with a sighting channel 241 that connects to the combustion chamber 200. The sight tube 240 is aligned with the sighting channel 241. The inner diameter of the sighting channel 241 gradually increases as it approaches the combustion chamber 200. Operators can monitor the combustion situation in the combustion chamber 200 through the sight tube 240 and the sighting channel 241, and use the flame monitoring tube 250 to monitor the return chamber 120.
[0038] In other alternative embodiments, such as Figure 4 As shown, the regulating device also includes regulating cylinders 230 that are connected one-to-one with connecting rods 220. The two ends of the regulating cylinders 230 are connected to the connecting rods 220 and the burner brick 100, respectively. The regulating cylinders 230 are used to drive the corresponding connecting rods 220 to move axially along the burner core 140. The regulating cylinders 230 can be regulating hydraulic cylinders, regulating pneumatic cylinders, or regulating electric cylinders. By setting the regulating cylinders 230 to drive the connecting rods 220 to move axially, thereby causing the regulating plate 210 to move axially along the burner core 140, the cross-sectional area at the connection between the return chamber 120 and the Laval channel 110 can be adjusted, thus enabling automatic control of the flow rate of the return flue gas flowing from the return chamber 120 into the Laval channel 110.
[0039] 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 pellet belt type indurating burner with an adjustable fume backflow structure, characterized by, The device includes a burner brick with a Laval channel and a reflux chamber, and a connecting flange connected to the burner brick. The two ends of the Laval channel are connected to the reflux chamber and the combustion chamber, respectively. One end of the connecting flange is connected to a burner core that extends through the reflux chamber and into one end of the Laval channel, and the other end is connected to an air pipe communicating with the burner core. The air pipe contains a gas pipe that extends into the burner core at one end, and the other end of the gas pipe extends out of the air pipe and is connected to a blind flange with an inspection hole. The air pipe and the gas pipe are respectively connected to an air inlet and a gas inlet. The burner brick also has multiple reflux channels communicating with the reflux chamber and the combustion chamber. The end of the burner brick away from the combustion chamber is provided with an ignition tube communicating with the reflux chamber. An adjusting plate and an adjusting device for driving the adjusting plate to move axially along the burner core are fitted on the burner core. When the adjusting plate moves axially along the burner core, it adjusts the cross-sectional area of the connection between the reflux chamber and the Laval channel.
2. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The adjusting device includes multiple connecting rods, one end of which is connected to the adjusting plate, and the other end of the connecting rods slides through the burner brick and the connecting flange.
3. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 2, characterized in that, The adjusting device also includes adjusting cylinders that are connected to each of the connecting rods in a one-to-one manner. The adjusting cylinders are used to drive the corresponding connecting rods to move axially along the burner core.
4. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The burner core is connected to a mixing plate at the end away from the connecting flange.
5. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The burner brick is also provided with a sight tube that connects to the reflux chamber, and the reflux chamber is provided with a sight channel that connects to the combustion chamber, with the sight tube aligned with the sight channel.
6. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 5, characterized in that, The inner diameter of the viewing channel gradually increases as it approaches the combustion chamber.
7. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The burner brick is also equipped with a flame monitoring tube that connects to the reflux chamber.
8. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The Laval channel includes a contraction section, a throat, and an expansion section connected in sequence. The contraction section and the expansion section are respectively connected to the reflux chamber and the combustion chamber, and the burner core extends into the contraction section.
9. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The plurality of the return channels are arranged at circumferential intervals along the Laval channel.
10. The pellet belt roasting burner with adjustable flue gas recirculation structure according to claim 1, characterized in that, The air inlet is connected to the bottom of the air pipe, and the gas inlet is connected to the top of the gas pipe.