Combustor and metal melting furnace structure

Abstract

The present application belongs to the technical field of burners, and particularly relates to a burner and a metal smelting furnace structure. The burner of the present application is provided with a first flame-stabilizing air jet and a first auxiliary gas jet. After ignition, the first flame-stabilizing air jet and the first auxiliary gas jet form a first auxiliary flame combustion zone. A second premixing combustion part further transports the first auxiliary flame of the first auxiliary flame combustion zone and the unburned first premixing jet stream to mix and burn with a second auxiliary gas jet. Through the interlacing, rubbing and collision of multiple streams, countless flame stagnation points with different vector directions and speeds are generated, forming a second auxiliary flame combustion zone. The second auxiliary flame combustion zone forms and provides a stable and reliable ignition source around the main flame combustion zone, avoiding the occurrence of flame loss and flameout of the main flame, and being reliable in use.

Description

Technical Field

[0001] This invention belongs to the field of burner technology, specifically relating to burner and metal furnace structures. Background Technology

[0002] Due to the need for energy conservation in industrial furnaces, high-temperature air combustion technology in regenerators has been widely applied. However, the high NOx emissions from high-temperature air combustion have become a significant limiting factor for its widespread adoption. In recent years, various low-NOx combustion technologies have been developed to reduce NOx emissions from high-temperature air combustion in regenerators. For example, the method of adding a central gas burner to regenerators on both sides in aluminum melting furnaces has achieved significant results in reducing NOx emissions. While this method has a significant emission reduction effect, it also brings other serious problems. Because the gas and air mix and burn inside the furnace, the gas jet is far from the air jet, resulting in extremely poor mixing and an inability to establish a stable flame. Once flameout or extinguishing occurs, it can easily lead to a gas explosion. Moreover, the unstable flame combustion and fluctuating ignition point make flame monitoring difficult, posing a significant safety hazard. Therefore, it is necessary to develop new central gas burner technology to leverage the ultra-low NOx emission advantages of high-temperature air combustion in regenerators while addressing the safety hazards it brings. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems of existing burners that cannot establish a stable flame on their own and are prone to flameout and extinction. The invention provides a burner and metal furnace structure that uses staged mixing and combustion of air and auxiliary gas to form and provide a stable and reliable ignition source around the main flame combustion zone.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The burner includes an igniter, a main gas output section, and an air-fuel premixed combustion section; the main gas output section is provided with a main gas nozzle at its end;

[0006] The air-fuel premixed combustion section is arranged around the outside of the main gas output section, including an auxiliary gas output section located outside the main gas output section, and a first premixed combustion section and a second premixed combustion section arranged sequentially along the gas conveying direction of the auxiliary gas output section. The auxiliary gas output section is provided with a first auxiliary gas nozzle located between the first premixed combustion section and the second premixed combustion section, and a second auxiliary gas nozzle located between the second premixed combustion section and the main gas nozzle.

[0007] The first premixed combustion section is provided with a plurality of first flame-stabilizing air nozzles and a plurality of first main combustion air nozzles in the circumferential direction. The first flame-stabilizing air jet generated by the first flame-stabilizing air nozzle is used to mix with the first auxiliary gas jet generated by the first auxiliary gas nozzle to form a first auxiliary flame combustion zone when ignited by the igniter.

[0008] The second premixed combustion section is provided with a plurality of second flame-stabilizing air nozzles and a plurality of second main combustion air nozzles in the circumferential direction. The second flame-stabilizing air nozzles are used to deliver the first auxiliary flame of the first auxiliary flame combustion zone and the unburned first premixed jet. The first premixed jet generated by the second flame-stabilizing air nozzles is used to mix with the second auxiliary gas jet generated by the second auxiliary gas nozzles to form the second auxiliary flame combustion zone under the ignition action of the first auxiliary flame.

[0009] The second main combustion air nozzle is used to transmit the main combustion air jet generated by the first main combustion air nozzle. The main combustion air jet generated by the second main combustion air nozzle is mixed with the main combustion gas jet generated by the main combustion gas nozzle and then forms the main combustion zone under the ignition of the second auxiliary flame in the second auxiliary flame combustion zone.

[0010] Compared with existing technologies, the burner of this invention forms a first auxiliary flame combustion zone after the first stabilizing air jet and the first auxiliary gas jet are mixed and ignited. The second premixed combustion section further transports the first auxiliary flame and unburned first premixed jet from the first auxiliary flame combustion zone to mix and burn with the second auxiliary gas jet. Through the interlacing, friction, and collision of multiple streams, countless flame stagnation points with different vector directions and velocities are generated, forming the second auxiliary flame combustion zone. This provides a stable and reliable ignition source around the main flame combustion zone, preventing flameout and extinguishing of the main flame, ensuring reliable operation. In addition to providing a reliable and stable ignition source for the flame combustion zone, the first and second auxiliary flame combustion zones can also provide the required flame rigidity, spread, and heat transfer performance by adjusting the auxiliary gas supply, as well as adjust the flame shape, length, and width. The burner's auxiliary flame is divided into two secondary combustion zones (first and second auxiliary flame combustion zones), achieving super-stable auxiliary main flame combustion, sufficient to handle various normal and abnormal operations on-site without flameout, flame lift-off, flame detachment, or backfire, ensuring the safety of the main flame operation. It also achieves an ultra-large control ratio to adapt to the special requirements of the process for flame performance, while ensuring that it has ultra-low nitrogen emissions.

[0011] Furthermore, the first and second premixed combustion sections are arranged around the outside of the auxiliary gas output section. The first main combustion air nozzle is located outside the first flame-stabilizing air nozzle, and the normal of the first flame-stabilizing air nozzle intersects or alternates with the normal of the first auxiliary gas nozzle. The second main combustion air nozzle is located outside the second flame-stabilizing air nozzle, and the normal of the second flame-stabilizing air nozzle intersects or alternates with the normal of the second auxiliary gas nozzle. This arrangement allows the generated first flame-stabilizing air jet and first auxiliary gas jet to achieve staggered mixing and combustion, forming a first auxiliary flame combustion zone with multiple flame-stabilizing vortices and independent stable combustion. Similarly, the generated second flame-stabilizing air jet and second auxiliary gas jet achieve staggered mixing and combustion, forming a second auxiliary flame combustion zone with multiple flame-stabilizing vortices and independent stable combustion.

[0012] Furthermore, the first flame-stabilizing air nozzle, the first main combustion air nozzle, the second flame-stabilizing air nozzle, and the second main combustion air nozzle are arranged along the axial direction of the main combustion gas output section; this arrangement ensures that the airflow generated by each air nozzle has a consistent direction, and the airflow delivery is smoother.

[0013] Furthermore, the first auxiliary gas nozzle is arranged radially along the axial direction of the main gas output section, and the second auxiliary gas nozzle includes a second auxiliary gas radial nozzle and a second auxiliary gas tilt nozzle arranged along the axial direction of the main gas output section. With this arrangement, the second auxiliary gas is supplied in two separate paths, and the airflow generated by the second flame stabilizing air nozzle and the second main combustion air nozzle will form countless flame stabilizing points with different vector directions and velocities through multiple streams intersecting, rubbing, and colliding, thus constituting multi-point flame stabilization conditions in the main flame combustion zone, resulting in a good flame stabilization effect for the main flame.

[0014] Furthermore, the normal of the second auxiliary gas radial nozzle intersects or is staggered with the normal of the second auxiliary gas tilt nozzle; this arrangement enables the second auxiliary gas generated by the second auxiliary gas nozzle to have a vortex effect, resulting in better mixing with the first premixed jet generated by the second flame stabilizing air nozzle.

[0015] Furthermore, the normals of the first flame-stabilizing air nozzle, the first main combustion air nozzle, the second flame-stabilizing air nozzle, and the second main combustion air nozzle are staggered from each other along the axial direction of the main combustion gas output section. This arrangement effectively extends the travel distance of the first flame-stabilizing air jet and the first main combustion air jet within the first auxiliary flame combustion zone, thereby extending the mixing time of the first flame-stabilizing air jet, the first main combustion air jet, and the first auxiliary combustion gas jet within the first auxiliary flame combustion zone, resulting in better gas-air mixing.

[0016] Furthermore, the first auxiliary gas jet generated by the first auxiliary gas nozzle accounts for 15-50% of the gas delivery volume of the auxiliary gas output section; the second auxiliary gas jet generated by the second auxiliary gas nozzle accounts for 50-85% of the gas delivery volume of the auxiliary gas output section; with this setting, the second auxiliary gas jet has a larger proportion, effectively improving the flame stabilization effect of the second auxiliary flame combustion zone.

[0017] Furthermore, the orifice width of the first main combustion air nozzle is smaller than that of the second main combustion air nozzle. This setting effectively reduces the flow velocity of the main combustion air jet through the second main combustion air nozzle, allowing the main combustion air jet to mix with the second auxiliary gas jet and the main gas jet for a longer time, resulting in a more thorough mixing effect.

[0018] Furthermore, it also includes a gas delivery section connected to the upstream end of the main gas output section and the air-fuel premixed combustion section, and a flame tube sleeved at the downstream end of the main gas output section and the air-fuel premixed combustion section. The gas delivery section is provided with a main gas conduit, an auxiliary gas delivery channel, and an air delivery channel located inside. The main gas conduit is connected to the main gas output section, the auxiliary gas delivery channel is connected to the auxiliary gas output section, and the air delivery channel is connected to the first premixed combustion section and the second premixed combustion section. With this arrangement, a flame tube is set at the downstream end of the main gas output section and the air-fuel premixed combustion section, so that the first auxiliary flame combustion zone, the second auxiliary flame combustion zone, and the main flame combustion zone form a relatively closed space, and the flame stabilization effect of each combustion zone is good.

[0019] The metal melting furnace structure includes a furnace body, a first heat storage and gas conveying chamber, a second heat storage and gas conveying chamber, a gas path switching control module, an air conveying pipe, a flue gas exhaust pipe, and a burner. The burner, the first heat storage and gas conveying chamber, and the second heat storage and gas conveying chamber are respectively connected to the furnace chamber of the furnace body. The burner is used to provide combustion conveying and ignition for the furnace body. The first heat storage and gas conveying chamber and the second heat storage and gas conveying chamber are respectively connected to the air conveying pipe and the flue gas exhaust pipe, which are used to convey air into the furnace chamber or to discharge the flue gas generated after combustion in the furnace chamber. The gas path switching control module is used to switch the air input state or the flue gas discharge state of the first heat storage and gas conveying chamber and the second heat storage and gas conveying chamber. With this setup, the first stabilizing air jet mixes and ignites with the first auxiliary gas jet to form the first auxiliary flame combustion zone. The second premixed combustion section further transports the first auxiliary flame and the unburned first premixed jet from the first auxiliary flame combustion zone to mix and burn with the second auxiliary gas jet. Through the interlacing, friction, and collision of multiple streams, countless flame stagnation points with different vector directions and velocities are generated, forming the second auxiliary flame combustion zone. This forms and provides a stable and reliable ignition source around the main flame combustion zone, preventing the main flame from detaching or going out, ensuring reliable operation. Attached Figure Description

[0020] Figure 1 Schematic diagram of the main gas output section and the air-fuel premixed combustion section

[0021] Figure 2 Schematic diagram of the burner

[0022] Figure 3 for Figure 2 Sectional view located in BB

[0023] Figure 4 for Figure 2 Sectional view located in AA

[0024] Figure 5 for Figure 2 Right side view of the burner

[0025] Figure 6 A schematic diagram of the structure of a metal furnace.

[0026] Figure 7 This is a diagram showing the working state of a metal furnace structure (the first heat storage and gas conveying chamber is in the flue gas discharge state, and the second heat storage and gas conveying chamber is in the air input state).

[0027] Figure 8 This is a diagram showing the working state of a metal furnace structure (the first heat storage and gas conveying chamber is in the air input state, and the second heat storage and gas conveying chamber is in the flue gas discharge state). Detailed Implementation

[0028] The technical solution of the present invention is described below with reference to the accompanying drawings:

[0029] Example 1:

[0030] See Figures 1 to 5 The burner 100 of the present invention includes an igniter 3, a main gas output section 1 and an air-fuel premixed combustion section 2; the main gas output section 1 is provided with a main gas nozzle 11 at its end.

[0031] The air-fuel premixed combustion section 2 is arranged around the outside of the main gas output section 1, including an auxiliary gas output section 21 located outside the main gas output section 1, and a first premixed combustion section 22 and a second premixed combustion section 23 arranged sequentially along the gas conveying direction of the auxiliary gas output section 21. The auxiliary gas output section 21 is provided with a first auxiliary gas nozzle 211 located between the first premixed combustion section 22 and the second premixed combustion section 23, and a second auxiliary gas nozzle 212 located between the second premixed combustion section 23 and the main gas nozzle 11.

[0032] The first premixed combustion section 22 is provided with a plurality of first flame-stabilizing air nozzles 221 and a plurality of first main combustion air nozzles 222 in the circumferential direction. The first flame-stabilizing air jet generated by the first flame-stabilizing air nozzles 221 is used to mix with the first auxiliary gas jet generated by the first auxiliary gas nozzles 211 to form a first auxiliary flame combustion zone 26 when ignited by the igniter 3.

[0033] The second premixed combustion section 23 is provided with a plurality of second flame-stabilizing air nozzles 231 and a plurality of second main combustion air nozzles 232 in the circumferential direction. The second flame-stabilizing air nozzles 231 are used to deliver the first auxiliary flame of the first auxiliary flame combustion zone 26 and the first premixed jet after the first flame-stabilizing air jet and the first auxiliary gas jet are mixed but not burned. The first premixed jet generated by the second flame-stabilizing air nozzles 231 is used to mix with the second auxiliary gas jet generated by the second auxiliary gas nozzles 212 to form the second auxiliary flame combustion zone 25 under the action of the first auxiliary flame ignition.

[0034] The second main combustion air nozzle 232 is used to transmit the main combustion air jet generated by the first main combustion air nozzle 222. The main combustion air jet generated by the second main combustion air nozzle 232 is mixed with the main combustion gas jet generated by the main combustion gas nozzle 11 and then forms the main combustion gas zone 25 under the action of the second auxiliary flame ignition in the second auxiliary flame combustion zone 25.

[0035] The first auxiliary gas nozzle 211 faces the first premixed combustion section 22 and is located near the first flame stabilizing air nozzle 221, and the second auxiliary gas nozzle 212 faces the second premixed combustion section 23 and is located near the second flame stabilizing air nozzle 231.

[0036] Compared with the prior art, the burner 100 of the present invention, after the first flame-stabilizing air jet and the first auxiliary gas jet are mixed and ignited, form a first auxiliary flame combustion zone 26. The second premixed combustion section 23 further transports the first auxiliary flame and the unburned first premixed jet from the first auxiliary flame combustion zone 26 to mix and burn with the second auxiliary gas jet. Through the interlacing, friction, and collision of multiple streams, countless flame stagnation points with different vector directions and velocities are generated, forming a second auxiliary flame combustion zone 25. This forms and provides a stable and reliable ignition source around the main flame combustion zone 25, avoiding flameout and flameout of the main flame, and ensuring reliable operation. In addition to providing a reliable and stable ignition source for the flame combustion zone 25, the first auxiliary flame combustion zone 26 and the second auxiliary flame combustion zone 25 can also provide the required flame rigidity, spread, and heat transfer performance by adjusting the auxiliary gas supply, as well as adjust the flame shape, length, and width. The auxiliary flame of the burner 100 is divided into a first auxiliary flame combustion zone 26 and a second auxiliary flame combustion zone 25, which enables super-stable auxiliary main flame combustion. This is sufficient to handle various normal and abnormal operations on site without flameout, flame lift-off, flame detachment, or backfire, ensuring the safety of the main flame operation. It also achieves an ultra-large control ratio to adapt to the special requirements of the process for flame performance, while simultaneously ensuring ultra-low nitrogen emissions.

[0037] See Figures 1 to 4 In one embodiment, the first premixed combustion section 22 and the second premixed combustion section 23 are arranged around the outside of the auxiliary gas output section 21. The first main combustion air nozzle 222 is located outside the first flame stabilizing air nozzle 221, and the normal of the first flame stabilizing air nozzle 221 intersects or alternates with the normal of the first auxiliary gas nozzle 211. The second main combustion air nozzle 232 is located outside the second flame stabilizing air nozzle 231, and the normal of the second flame stabilizing air nozzle 231 intersects or alternates with the normal of the second auxiliary gas nozzle 212. This arrangement allows the generated first flame stabilizing air jet and the first auxiliary gas jet to achieve staggered mixing and combustion, forming a first auxiliary flame combustion zone 26 with multiple flame stabilizing vortices and independent stable combustion. Similarly, the generated second flame stabilizing air jet and the second auxiliary gas jet achieve staggered mixing and combustion, forming a second auxiliary flame combustion zone 25 with multiple flame stabilizing vortices and independent stable combustion.

[0038] In one embodiment, the first flame stabilizing air nozzle 221, the first main combustion air nozzle 222, the second flame stabilizing air nozzle 231, and the second main combustion air nozzle 232 are arranged along the axial direction of the main combustion gas output section 1, respectively. By setting it in this way, the airflow generated by each air nozzle has a consistent direction, and the airflow delivery is smoother.

[0039] See Figures 1 to 5In one embodiment, the first premixed combustion section 22 and the second premixed combustion section 23 are arranged at intervals relative to each other, and the first flame stabilizing air nozzle 221, the first main combustion air nozzle 222, the second flame stabilizing air nozzle 231 and the second main combustion air nozzle 232 are interconnected. With this arrangement, the main combustion air jet flowing from the first auxiliary flame combustion zone 26 into the second auxiliary flame combustion zone 25 is no longer just air, but a complex flow field in the second auxiliary flame combustion zone 25 mixed with the first premixed jet, the first auxiliary flame, and the first auxiliary gas jet, thereby generating a super-stable flame, which constitutes the technical basis for the flame stabilization effect of the burner 100.

[0040] See Figures 1 to 4 In one embodiment, the first auxiliary gas nozzle 211 is arranged radially along the axial direction of the main gas output section 1, and the second auxiliary gas nozzle 212 includes a second auxiliary gas radial nozzle 2121 and a second auxiliary gas tilt nozzle 2122 arranged along the axial direction of the main gas output section 1. The angle between the second auxiliary gas tilt nozzle 2122 and the axial direction of the main gas output section 1 is an acute angle α°. With this arrangement, the second auxiliary gas is supplied in two directions, and the airflow generated by the second flame stabilizing air nozzle 231 and the second main combustion air nozzle 232 forms numerous flame stabilizing points with different vector directions and velocities through multiple flow streams intersecting, rubbing, and colliding. This constitutes the multi-point flame stabilization conditions of the main flame combustion zone 25, resulting in a good flame stabilization effect for the main flame.

[0041] In one embodiment, the normal of the second auxiliary gas radial nozzle 2121 intersects or is staggered with the normal of the second auxiliary gas angle nozzle 2122. The second auxiliary gas radial nozzle 2121 is located on the side of the second auxiliary gas angle nozzle 2122 downstream of the main combustion air jet in the vertical direction, and the angle between the second auxiliary gas radial nozzle 2121 and the second auxiliary gas angle nozzle 2122 is an acute angle. With this arrangement, the second auxiliary gas generated by the second auxiliary gas nozzle 212 has a vortex effect, and the mixing effect with the first premixed jet generated by the second flame stabilizing air nozzle 231 is better.

[0042] See Figure 1In one embodiment, the normals of the first flame stabilizing air nozzle 221, the first main combustion air nozzle 222, the second flame stabilizing air nozzle 231, and the second main combustion air nozzle 232 are respectively staggered along the axial direction of the main gas output section 1. By setting it this way, the travel distance of the first flame stabilizing air jet and the first main combustion air jet in the first auxiliary flame combustion zone 26 is effectively extended, thereby extending the mixing time of the first flame stabilizing air jet, the first main combustion air jet, and the first auxiliary gas jet in the first auxiliary flame combustion zone 26, resulting in a better gas-air mixing effect.

[0043] See Figures 1 to 4 In one embodiment, the first auxiliary gas jet generated by the first auxiliary gas nozzle 211 accounts for 15-50% of the gas delivery volume of the auxiliary gas output section 21; the second auxiliary gas jet generated by the second auxiliary gas nozzle 212 accounts for 50-85% of the gas delivery volume of the auxiliary gas output section 21. With this arrangement, the second auxiliary gas jet has a larger proportion, effectively improving the flame stabilization effect of the second auxiliary flame combustion zone 25.

[0044] See Figure 1 In one embodiment, the orifice width of the first main combustion air nozzle 222 is smaller than the orifice width of the second main combustion air nozzle 232. By setting it in this way, the flow velocity of the main combustion air jet through the second main combustion air nozzle 232 is effectively reduced, so that the main combustion air jet mixes with the second auxiliary gas jet and the main gas jet for a longer time and the mixing effect is more complete.

[0045] See Figures 1 to 5 In one embodiment, the system further includes a gas delivery section 26 connected upstream of the main gas output section 1 and the air-fuel premixed combustion section 2, and a flame tube 27 sleeved at the downstream end of the main gas output section 1 and the air-fuel premixed combustion section 2. The gas delivery section 26 has a main gas conduit 261, an auxiliary gas delivery channel 262, and an air delivery channel 263 located inside. The main gas conduit 261 communicates with the main gas output section 1, and a main gas inlet 264 is provided upstream of the main gas conduit 261. The auxiliary gas delivery channel 262 communicates with the auxiliary gas output section 263. The gas output section 21 is connected, and the auxiliary gas delivery channel 262 is provided with an auxiliary gas inlet 265 upstream. The air delivery channel 263 is connected to the first premixed combustion section 22 and the second premixed combustion section 23, and the air delivery channel 263 is provided with an air inlet 266 upstream. With this arrangement, a flame tube 27 is provided at the downstream end of the main gas output section 1 and the air-fuel premixed combustion section 2, so that the first auxiliary flame combustion zone 26, the second auxiliary flame combustion zone 25 and the main flame combustion zone 25 form a relatively closed space, and the flame stabilization effect of each combustion zone is good.

[0046] In one embodiment, the auxiliary gas accounts for 3-20% of the total gas supply, resulting in a stable auxiliary flame with a wide operating range, good flame monitoring performance, and a large adjustment ratio. The main gas accounts for 80% of the total gas supply.

[0047] See Figures 1 to 4 In one embodiment, the igniter 3 is disposed between the first premixed combustion section 22 and the second premixed combustion section 23 and connects the first auxiliary flame combustion zone 26 and the second auxiliary flame combustion zone 24, for igniting the air-fuel premixed gas formed between the first premixed combustion section 22 and the second premixed combustion section 23.

[0048] In one embodiment, an auxiliary flame monitor 4 is also included for detecting the first auxiliary flame and the second auxiliary flame.

[0049] The burner 100 has an independent combustion control and monitoring system. When the total power of the burner 100 is less than 500 kW, the igniter 3 can be an electric spark igniter 3; when the total power of the burner 100 is greater than 500 kW, the igniter 3 can be a burner nozzle.

[0050] The burner 100 of this invention operates with the following startup sequence: igniter 3 is started; after a stable and reliable ignition flame is detected by igniter 3, auxiliary gas is introduced to start the auxiliary flame; after the auxiliary flame signal is stably detected by the dedicated flame monitor, main gas is introduced to start the main flame. Subsequently, the parameters of the auxiliary flame and main flame are adjusted to achieve the flame characteristics required by the process, and the burner enters normal operating condition.

[0051] Example 2:

[0052] See Figures 6 to 8 The main purpose of this embodiment is to provide a metal furnace structure 5 using the burner 100 of Embodiment 1, including a furnace body 51, a first heat storage and gas delivery chamber 52, a second heat storage and gas delivery chamber 53, a gas path switching control module (not shown), an air delivery pipe 54, a flue gas discharge pipe 55, and the burner 100. The burner 100, the first heat storage and gas delivery chamber 52, and the second heat storage and gas delivery chamber 53 are respectively connected to the furnace chamber of the furnace body 51. The burner 100 is used to provide combustion delivery and ignition for the furnace body 51. The first heat storage and gas delivery chamber 52 and the second heat storage and gas delivery chamber 53 are respectively connected to the air delivery pipe 54 and the flue gas discharge pipe 55, and are used to deliver air to the furnace chamber or to discharge the flue gas generated after combustion in the furnace chamber. The gas path switching control module is used to switch the air input state or the flue gas discharge state of the first heat storage and gas delivery chamber 52 and the second heat storage and gas delivery chamber 53.

[0053] When the first heat storage and gas conveying chamber 52 and the second heat storage and gas conveying chamber 53 are used in the flue gas discharge state, they can absorb the heat of the high-temperature flue gas to heat their own bodies. When they are switched to the air input state, they heat the input cold air to high-temperature combustion air and then discharge it into the furnace body 51, thereby improving the heating efficiency of the metal furnace structure 5.

[0054] See Figures 6 to 8 When the metal furnace structure 5 is in use, the following working process is included: After the new low-NOx burner is started, cold air is supplied to the first heat storage and gas conveying chamber 52. After being heated by the hot first heat storage and gas conveying chamber 52, it becomes high-temperature combustion air and is injected into the furnace. It mixes and burns with the fuel-rich flame injected by the new low-NOx burner, transferring heat to the heated material. The resulting flue gas is then drawn into the second heat storage and gas conveying chamber 53. Most of the heat from the high-temperature flue gas is used to heat the body of the second heat storage and gas conveying chamber 53. When the temperature of the first heat storage and gas conveying chamber 52 drops to insufficient heat storage, the operating states of the first heat storage and gas conveying chamber 52 and the second heat storage and gas conveying chamber 53 switch with each other. The first heat storage and gas conveying chamber provides hot air, while the first heat storage and gas conveying chamber 52 draws in flue gas and enters the heat storage state.

[0055] Compared with the prior art, the metal furnace structure 5 of the present invention forms a first auxiliary flame combustion zone 26 after the first flame-stabilizing air jet and the first auxiliary gas jet are mixed and ignited. The second premixed combustion section 23 further transports the first auxiliary flame and the unburned first premixed jet in the first auxiliary flame combustion zone 26 to mix and burn with the second auxiliary gas jet. Through the interlacing, friction and collision of multiple streams, countless flame stagnation points with different vector directions and velocities are generated to form a second auxiliary flame combustion zone 25, which forms and provides a stable and reliable ignition source around the main flame combustion zone 25, avoiding flameout and flameout of the main flame, and is reliable in use.

[0056] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A burner, characterized in that, include: Ignition device; The main gas output section is equipped with a main gas nozzle at the end. An air-fuel premixed combustion section is arranged around the outside of the main gas output section, including an auxiliary gas output section located outside the main gas output section, and a first premixed combustion section and a second premixed combustion section arranged sequentially along the gas conveying direction of the auxiliary gas output section. The auxiliary gas output section is provided with a first auxiliary gas nozzle located between the first premixed combustion section and the second premixed combustion section, and a second auxiliary gas nozzle located between the second premixed combustion section and the main gas nozzle. The first premixed combustion section is provided with a plurality of first flame-stabilizing air nozzles and a plurality of first main combustion air nozzles in the circumferential direction. The first flame-stabilizing air jet generated by the first flame-stabilizing air nozzle is used to mix with the first auxiliary gas jet generated by the first auxiliary gas nozzle to form a first auxiliary flame combustion zone when the igniter is ignited. The second premixed combustion section is provided with a plurality of second flame-stabilizing air nozzles and a plurality of second main combustion air nozzles in the circumferential direction. The second flame-stabilizing air nozzles are used to deliver the first auxiliary flame in the first auxiliary flame combustion zone and the unburned first premixed jet. The first premixed jet generated by the second flame-stabilizing air nozzles is used to mix with the second auxiliary gas jet generated by the second auxiliary gas nozzles to form the second auxiliary flame combustion zone under the ignition action of the first auxiliary flame. The second main combustion air nozzle is used to transmit the main combustion air jet generated by the first main combustion air nozzle. The main combustion air jet generated by the second main combustion air nozzle is mixed with the main combustion gas jet generated by the main combustion gas nozzle and then forms the main combustion zone under the ignition of the second auxiliary flame in the second auxiliary flame combustion zone.

2. The burner according to claim 1, characterized in that, The first premixed combustion section and the second premixed combustion section are arranged around the outside of the auxiliary gas output section. The first main combustion air nozzle is located outside the first flame stabilizing air nozzle. The normal of the first flame stabilizing air nozzle intersects or is staggered with the normal of the first auxiliary gas nozzle. The second main combustion air nozzle is located outside the second flame stabilizing air nozzle. The normal of the second flame stabilizing air nozzle intersects or is staggered with the normal of the second auxiliary gas nozzle.

3. The burner according to claim 2, characterized in that, The first flame-stabilizing air nozzle, the first main combustion air nozzle, the second flame-stabilizing air nozzle, and the second main combustion air nozzle are arranged along the axial direction of the main combustion gas output section, respectively. The first premixed combustion section and the second premixed combustion section are arranged at intervals relative to each other, and the first flame stabilizing air nozzle, the first main combustion air nozzle, the second flame stabilizing air nozzle and the second main combustion air nozzle are interconnected.

4. The burner according to claim 3, characterized in that, The first auxiliary gas nozzle is arranged radially along the axial direction of the main gas output section, and the second auxiliary gas nozzle includes a second auxiliary gas radial nozzle and a second auxiliary gas tilt nozzle arranged along the axial direction of the main gas output section.

5. The burner according to claim 4, characterized in that, The normal to the second auxiliary gas radial nozzle intersects with or is staggered with the normal to the second auxiliary gas inclined nozzle.

6. The burner according to claim 3, characterized in that, The normals of the first flame-stabilizing air nozzle, the first main combustion air nozzle, the second flame-stabilizing air nozzle, and the second main combustion air nozzle are respectively staggered from each other along the axial direction of the main combustion gas output section.

7. The burner according to claim 1, characterized in that, The first auxiliary gas jet generated by the first auxiliary gas nozzle accounts for 15-50% of the gas delivery volume of the auxiliary gas output section; the second auxiliary gas jet generated by the second auxiliary gas nozzle accounts for 50-85% of the gas delivery volume of the auxiliary gas output section.

8. The burner according to claim 3 or 6, characterized in that, The orifice width of the first main combustion air nozzle is smaller than that of the second main combustion air nozzle.

9. The burner according to any one of claims 1 to 7, characterized in that, It also includes a gas delivery section connected to the upstream end of the main gas output section and the air-fuel premixed combustion section, and a flame tube sleeved at the downstream end of the main gas output section and the air-fuel premixed combustion section. The gas delivery section is provided with a main gas conduit, an auxiliary gas delivery channel and an air delivery channel located inside. The main gas conduit is connected to the main gas output section, the auxiliary gas delivery channel is connected to the auxiliary gas output section, and the air delivery channel is connected to the first premixed combustion section and the second premixed combustion section.

10. A metal furnace structure, characterized in that, The device includes a furnace body, a first heat storage and gas delivery chamber, a second heat storage and gas delivery chamber, a gas path switching control module, an air delivery pipe and a flue gas emission pipe, and a burner as described in any one of claims 1 to 9. The burner, the first heat storage and gas delivery chamber, and the second heat storage and gas delivery chamber are respectively connected to the furnace chamber of the furnace body. The burner is used to provide combustion delivery and ignition for the furnace body. The first heat storage and gas delivery chamber and the second heat storage and gas delivery chamber are respectively connected to the air delivery pipe and the flue gas emission pipe, and are used to deliver air to the furnace chamber or to discharge the flue gas generated after combustion in the furnace chamber. The gas path switching control module is used to switch the air input state or the flue gas discharge state of the first heat storage and gas delivery chamber and the second heat storage and gas delivery chamber.

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