Low-air-fuel-ratio roller kiln burner

Abstract

The invention belongs to the technical field of combustors, and particularly relates to a low-air-fuel-ratio roller kiln combustor. According to the low-air-fuel-ratio roller kiln burner, fuel gas jet flow conveyed by a fuel gas conveying hole and primary air conveyed by an air distribution chamber are premixed in a premixing chamber in a premixed gas conveying part to form uniform premixed gas, and conical film-shaped primary premixed jet flow is formed under the cooperation of a conical flow guide diffuser and a primary premixed gas annular nozzle; flame rigidity and combustion stability are improved; meanwhile, a secondary air nozzle obliquely arranged on the air conveying air disc sprays out secondary air jet flow at a specific angle, the secondary air jet flow intersects with the primary premixing jet flow to form multi-stage flame stabilizing vortexes, the mixing path is prolonged, sufficient combustion under the low-air-fuel ratio is ensured, the smoke heat loss is reduced, and the energy efficiency is improved; the anti-coking performance is enhanced through multi-stage vortexes, the carbon deposition frequency and the kiln stopping cleaning frequency are reduced, and the production continuity is guaranteed; the problems that a traditional combustor is high in smoke heat loss, prone to coking shutdown, poor in pressure adaptability and the like are comprehensively solved, and the decoking frequency is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of burners, and particularly relates to a low air-fuel ratio roller kiln burner. BACKGROUND

[0002] In the production cost composition of ceramic industry roller kiln, fuel expenditure accounts for as high as 60% to 80%, and its price fluctuation has a decisive influence on the profit level of enterprises. The conventional burners commonly used at present have multiple technical bottlenecks under the condition of low air excess coefficient (α<1). On the one hand, insufficient combustion leads to weakened flame rigidity, decreased stability, increased flue gas heat loss and reduced energy efficiency; on the other hand, the system has insufficient anti-coking performance, which easily causes carbon deposition in the fire tube, forces the equipment to frequently stop kiln cleaning, and seriously restricts the continuity and stability of production. In addition, the adaptability of such burners to the change of combustion air pressure is poor, especially under ultra-low pressure (such as below 500 Pa), it is difficult to maintain stable combustion, thereby limiting the further optimization space of the kiln system in energy saving. SUMMARY

[0003] The purpose of the present application is to overcome the problems of insufficient gas combustion, poor flame rigidity and easy carbon deposition of the existing roller kiln burners under the condition of low air excess coefficient, and to provide a low air-fuel ratio roller kiln burner with sufficient combustion under the condition of low air excess coefficient.

[0004] In order to achieve the above purpose, the present application adopts the following technical scheme: The low air-fuel ratio roller kiln burner comprises an igniter, an air conveying pipe, a premixed gas conveying part and an air conveying air disc.

[0005] The air conveying pipe is provided with an air conveying channel located at the inner side, and the outer end opening of the air conveying channel forms a flame spout.

[0006] The premixed gas conveying part is arranged in the air conveying channel and is provided with an air distribution chamber located at the inner end, a premixing chamber located outside the air distribution chamber and having an outer end opening, and a conical flow guide diffuser. The inner side of the air distribution chamber is provided with an air conveying hole communicating with the air conveying channel. The premixed gas conveying part is provided with a plurality of gas conveying holes arranged in the axial direction and a gas annular mixing chamber around the outer side of the air distribution chamber. Each gas conveying hole communicates with the premixing chamber through the gas annular mixing chamber, and the outer ends of each gas conveying hole communicate with each other through the gas annular mixing chamber. The conical flow guide diffuser is arranged in the premixing chamber and is concentrically arranged with the air distribution chamber. The outer diameter of the conical flow guide diffuser gradually increases in the outer side direction. The inner circumference of the opening of the premixing chamber and the outer circumference of the bottom of the conical flow guide diffuser form a primary premixed gas annular spout.

[0007] The air conveying air disc is connected around the outer periphery of the outer end of the premixed gas conveying part and is provided with a plurality of secondary air spouts arranged obliquely along the center line direction of the premixed gas conveying part.

[0008] The gas delivery hole is used to deliver the gas jet along the ring direction through the gas annular mixing chamber, then deliver the gas jet to the primary air jet delivered by the air distribution chamber after the premixing in the premixing chamber, then the primary premixed gas annular jet is formed into a conical thin film primary premixed jet and combusted, and then the primary premixed jet is ejected from the primary premixed gas annular nozzle, and the secondary air jet generated by the secondary air nozzle on the air delivery disc intersects with the primary premixed jet at a certain angle to form a multi-stage stable flame vortex, and the secondary air jet generated by the secondary air nozzle is also used to prolong the mixing path of the primary premixed jet and the secondary air jet during combustion.

[0009] Compared with the prior art, the low air-fuel ratio roller kiln burner of the application improves the flame rigidity and combustion stability by premixing the gas jet delivered by the gas delivery hole in the premixed gas delivery part and the primary air delivered by the air distribution chamber in the premixing chamber to form uniform premixed gas, and forming a conical thin film primary premixed jet under the cooperation of the conical flow guide diffuser and the primary premixed gas annular nozzle; meanwhile, the secondary air nozzle arranged obliquely on the air delivery disc sprays the secondary air jet at a certain angle to intersect with the primary premixed jet to form a multi-stage stable flame vortex, prolong the mixing path, ensure sufficient combustion under low air-fuel ratio, reduce flue gas heat loss, and improve energy efficiency; the multi-stage vortex strengthens the anti-coking performance, reduces the carbon deposition and the cleaning frequency, and ensures the production continuity; in addition, the staged supply structure of the primary premixed jet and the secondary air enhances the adaptability to the combustion air pressure fluctuation, so that the burner can still maintain flame stability under ultra-low pressure, and comprehensively solves the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of the traditional burner, and can reduce fuel consumption by more than 15% compared with the traditional burner, greatly reducing the decoking frequency.

[0010] Further, the gas annular mixing chamber is provided with a gas annular nozzle at the outer end, and the ring width of the gas annular nozzle is smaller than the ring width of the gas annular mixing chamber; by setting the ring width of the gas annular nozzle to be smaller than the ring width of the gas annular mixing chamber, the flow rate and jet kinetic energy of the gas jet are effectively improved, the premixing effect with the primary air is enhanced, and the uniformity and combustion stability of the premixed gas are further optimized, which helps to reduce the air-fuel ratio and reduce the formation of carbon deposition.

[0011] Further, the conical flow guide diffuser is connected with the inner end of the air distribution chamber through a connecting column, and the connecting column is cylindrical and has an outer diameter smaller than the conical flow guide diffuser; by adopting the cylindrical connecting column with an outer diameter smaller than the conical flow guide diffuser for connection, the blocking and interference of the connecting structure to the primary air and the premixed gas flow are minimized, and the smooth flow and uniform mixing of the gas flow in the premixing chamber are ensured, thereby helping to form a more stable conical thin film premixed jet, improving the flame quality and combustion efficiency.

[0012] Further, the outer diameter of the outer end of the conical flow guide diffuser is greater than or equal to the inner diameter of the air distribution chamber and less than the inner diameter of the premixing chamber; by setting the outer diameter of the outer end of the conical flow guide diffuser to be greater than or equal to the inner diameter of the air distribution chamber and less than the inner diameter of the premixing chamber, the size of the annular jet of the primary premixed gas between the conical flow guide diffuser and the wall of the premixing chamber is accurately defined, ensuring that the premixed gas can be ejected at a high speed in the form of a uniform conical film, effectively improving the rigidity and stability of the flame, and optimizing the mixing efficiency with the secondary air, making the combustion more complete.

[0013] Further, the bottom of the conical flow guide diffuser extends outside the opening of the premixing chamber, and the outer end of the conical flow guide diffuser does not extend outside the outer end of the air delivery air disc or the air delivery pipe; by extending the bottom of the conical flow guide diffuser to the outside of the opening of the premixing chamber but not beyond the outer end of the burner, the conical film-shaped premixed jet flow is effectively guided and protected from premature diffusion or interference, while ensuring that the premixed jet flow can mix with the secondary air jet at the optimal position and angle at the outlet of the burner, thereby strengthening the formation of multi-stage stable flame vortices and further improving the stability and efficiency of combustion.

[0014] Further, the secondary air jet is provided with multiple in the radial direction of the air delivery air disc; by providing multiple secondary air jets in the radial direction of the air delivery air disc, the coverage range of the secondary air jet and the intersection point with the primary premixed jet flow are significantly increased, thereby forming more levels and more evenly distributed stable flame vortices, greatly extending the mixing path and strengthening the turbulent mixing effect, ensuring the complete combustion of fuel under low air-fuel ratio conditions, while effectively improving the stability of the flame and the adaptability of the burner to load changes.

[0015] Further, the air delivery holes are arranged in the radial direction and are arranged in opposite staggered arrangement with the gas delivery holes; by arranging the air delivery holes and the gas delivery holes in opposite staggered arrangement, the two types of holes are structurally avoided from crossing in the premixed gas delivery part, simplifying the processing process and enhancing the structural strength; at the same time, this layout ensures that the primary air and gas jet can maintain their own independent flow paths until the premixing stage when entering the premixing chamber, thereby achieving more complete and controllable mixing in the premixing chamber, which is beneficial to the formation of uniform and stable premixed gas and improves the combustion efficiency.

[0016] Further, the air delivery pipe is provided with an air inlet adjusting valve; by setting the air inlet adjusting valve, the air intake can be adjusted according to process requirements.

[0017] Further, the air intake regulating valve comprises a valve housing, a rotary valve core and a regulating handle, the valve housing is provided with a valve housing cavity on the inner side, an air inlet and an air outlet which are communicated with both ends of the valve housing cavity, a rotary mounting seat is arranged in the valve housing cavity, the rotary mounting seat is provided with a rotary movable cavity arranged along the radial direction of the valve housing cavity, flow regulating holes which are communicated with the air inlet and the air outlet are arranged at both ends of the rotary movable cavity, the rotary valve core is rotatably arranged in the rotary movable cavity, a valve core cavity is arranged in the rotary valve core along the radial direction, the regulating handle is arranged outside the valve housing and is in transmission connection with the rotary valve core, the air flow between the valve core cavity and the valve housing cavity is regulated by controlling the relative rotation of the rotary valve core, so that the air intake of the air delivery channel is regulated; the precise regulation and rapid response of the combustion air flow are realized; the rotation of the rotary valve core in the rotary movable cavity can infinitely adjust the alignment area of the valve core cavity and the flow regulating hole, so that the air flow is controlled with high precision.

[0018] Further, the air intake regulating valve further comprises a valve cover, the valve cover is provided with a avoiding port corresponding to the regulating handle, the valve housing is provided with a assembly port which is opened along the radial direction and is communicated with the rotary movable cavity, the rotary valve core is assembled in the rotary movable cavity through the assembly port, the inner end of the rotary valve core is assembled in the rotary movable cavity through the corrugated spring, the valve cover is connected with the assembly port to fix the rotary valve core in the rotary movable cavity, and the valve cover is in sealing cooperation with the outer end of the rotary valve core through a sealing ring; by optimizing the sealing and assembly structure of the air intake regulating valve, the reliability and maintenance convenience of the equipment are significantly improved; the cooperation design of the valve cover and the assembly port realizes the quick disassembly and assembly of the rotary valve core, the elastic support of the corrugated spring not only ensures the flexibility of the valve core rotation but also automatically compensates the wear gap, so that the air intake regulating valve still maintains the precise regulation performance after long-term use, and the product has good use reliability.

[0019] Further, the regulating handle is provided with a valve position pointer; the configuration of the valve position pointer enables the operator to intuitively and accurately read the opening position of the current air intake regulating valve, so that the visual adjustment of the air-fuel ratio is realized, and the consistency of repeated adjustment is ensured through the scale mark; the design realizes the linkage of the mechanical indication and the regulating handle, so that the worker can quickly adjust the air intake regulating valve to the preset optimal working point, and the adjustment precision and operation reliability of the combustion system under the low air-fuel ratio working condition are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic view of the low air-fuel ratio roller kiln burner located at the top of the air delivery pipe and the premixed gas delivery part.

[0021] Figure 2 A Figure 1 A sectional view of D-D.

[0022] Figure 3The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner.

[0023] Figure 4 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 2 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner.

[0024] Figure 5 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 2 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner.

[0025] Figure 6 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 2 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner.

[0026] Figure 7 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 2 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner.

[0027] Figure 8 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 1 .

[0028] Figure 9 The sectional view of the air intake regulating valve for low air-fuel ratio roller kiln burner. Figure 2 .

[0029] Explanation of reference numerals: igniter 5, air delivery pipe 2, premix gas delivery part 1, air delivery fan disc 3, air delivery channel 21, flame spout 22, gas delivery pipe 4, gas delivery channel 41, conical flow guide diffuser 12, air distribution chamber 11, premix chamber 13, air delivery hole 111, gas delivery hole 141, gas annular mixing chamber 15, primary premix gas annular spout 16, gas distribution chamber 14, secondary air spout 31, gas annular spout joint 151, connecting column 121, gas delivery body 140, air delivery body 110, guide slope 152, air intake regulating valve 6, valve housing 61, rotary valve core 62, regulating handle 63, air inlet 64, air outlet 65, rotary mounting seat 66, rotary movable cavity 661, flow regulating hole 67, valve core cavity 621, valve cover 68, avoiding port 69, assembly port 611, corrugated spring 613, sealing ring 614, valve position pointer 615. DETAILED DESCRIPTION

[0030] The specific embodiments of the present application will be described below with reference to the drawings. In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the device or element indicated to have a specific orientation, to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0031] Reference Figures 1 to 9The low air-fuel ratio roller kiln burner of the present invention includes an igniter 5, an air delivery pipe 2, a fuel gas delivery pipe 4, a premixed gas delivery part 1 and an air delivery fan disc 3.

[0032] The air delivery pipe 2 is provided with an air delivery channel 21 located on the inner side, and the outer end of the air delivery channel 21 is opened to form a flame nozzle 22.

[0033] The gas delivery pipe 4 is arranged in the air delivery channel 21 and is provided with a gas delivery channel 41 located on the inner side. The gas delivery channel 41 is used to provide and deliver the gas jet.

[0034] The premixed gas delivery portion 1 is provided in the air delivery channel 21 and is provided with an air distribution chamber 11 at the inner end, a premixing chamber 13 located outside the air distribution chamber 11 and open at the outer end, and a conical guide diffuser 12. The air distribution chamber 11 is provided with an air delivery hole 111 connected to the air delivery channel 21 on the inner side. The premixed gas delivery portion 1 is provided with a plurality of axially arranged gas delivery holes 141 and a gas annular mixing chamber 15 around the outer side of the air distribution chamber 11. The inner end of the gas delivery hole 141 is connected to the gas delivery channel 41. Each gas delivery hole 141 is connected to the gas delivery channel 41. The outer ends of the gas delivery holes 141 are connected to each other through the gas annular mixing chamber 15. The conical guide diffuser 12 is arranged in the premixing chamber 13 and is concentric with the air distribution chamber 11. Specifically, the centers of the two circles coincide with each other or the center lines of the two coincide with each other. The premixing chamber 13 and the air distribution chamber 11 are preferably circular. The outer diameter of the conical guide diffuser 12 gradually increases along the outer direction. A primary premixed gas annular nozzle 16 is formed between the inner periphery of the opening of the premixing chamber 13 and the outer periphery of the bottom of the conical guide diffuser 12.

[0035] The air delivery fan 3 is connected around the outer periphery of the premixed gas delivery part 1 and is provided with a plurality of secondary air nozzles 31 arranged obliquely along the center line of the premixed gas delivery part 1. The premixed gas delivery part 1 and the air delivery fan 3 are preferably an integrated structure.

[0036] The gas delivery hole 141 is used to convey the gas jet axially to the premixing chamber 13 after it flows annularly through the gas annular mixing chamber 15 and is premixed with the primary air jet delivered by the air distribution chamber 11, and then ejected from the primary premixed gas annular nozzle 16 to form a conical film-shaped primary premixed jet and burn, and then intersect with the secondary air jet generated by the secondary air nozzle 31 on the air delivery wind disk 3 at a certain angle to form a multi-stage flame-stabilizing vortex. The secondary air jet generated by the secondary air nozzle 31 is also used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion.

[0037] The gas delivery holes 141 are provided in multiple numbers, and three of the gas delivery holes 141 are provided in each of the four directions of the premixed gas delivery part 1, and the gas delivery holes 141 in adjacent groups are provided with the radially arranged air delivery holes 111.

[0038] Compared with the prior art, the low-air-fuel ratio roller kiln burner of the present application can improve the flame rigidity and combustion stability by premixing the gas jet delivered by the gas delivery holes 141 in the premixed gas delivery part 1 with the primary air delivered by the air distribution chamber 11 in the premixing chamber 13 to form uniform premixed gas, and forming a conical thin film-shaped primary premixed jet flow under the cooperation of the conical flow guide diffuser 12 and the primary premixed gas annular nozzle 16; meanwhile, the secondary air jet flow is sprayed out from the secondary air nozzles 31 of the air delivery fan disc 3 at a specific angle to intersect with the primary premixed jet flow to form a multi-stage stable flame vortex, thereby prolonging the mixing path, ensuring sufficient combustion at a low air-fuel ratio, reducing the flue gas heat loss, and improving the energy efficiency; the multi-stage vortex can strengthen the anti-coking performance, reduce the carbon deposition and the cleaning frequency, and ensure the production continuity; in addition, the primary premixed jet flow and the secondary air staged supply structure can enhance the adaptability to the combustion air pressure fluctuation, so that the burner can still maintain flame stability at an ultra-low pressure, and the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of the traditional burner can be comprehensively solved, and the fuel consumption can be reduced by more than 15% compared with the traditional burner, and the decoking frequency can be greatly reduced.

[0039] Referring to Figures 1 to 7 In an embodiment, the outer end of the gas annular mixing chamber 15 is provided with a gas annular nozzle 151, the ring width of the gas annular nozzle 151 is smaller than the ring width of the gas annular mixing chamber 15, and the inner side of the gas annular mixing chamber 15 is transitionally connected to the gas annular nozzle 151 through a guide slope 152; by setting the ring width of the gas annular nozzle 151 to be smaller than the ring width of the gas annular mixing chamber 15, the flow rate and the jet kinetic energy of the gas jet flow are effectively improved, the premixing effect with the primary air is enhanced, the uniformity of the premixed gas and the combustion stability are further optimized, which is helpful to reduce the air-fuel ratio and reduce the carbon deposition.

[0040] Referring to Figures 1 to 7 In an embodiment, the conical flow guide diffuser 12 is connected to the inner end of the air distribution chamber 11 through a connecting column 121, and the connecting column 121 is in a cylindrical shape and has an outer diameter smaller than the conical flow guide diffuser 12; by adopting the cylindrical connecting column 121 with an outer diameter smaller than the conical flow guide diffuser 12 for connection, the blocking and interference of the connecting structure to the primary air and the premixed gas flow are minimized, the smooth flow and uniform mixing of the gas flow in the premixing chamber 13 are ensured, and thus a more stable conical thin film-shaped premixed jet flow can be formed, and the flame quality and the combustion efficiency are improved.

[0041] Referring to Figures 1 to 7In an embodiment, the premixed gas delivery part 1 comprises a gas delivery body 140 and an air delivery body 110 arranged in the gas delivery body 140, the gas delivery holes 141 are arranged in the gas delivery body 140, and the air distribution chamber 11 is arranged in the air delivery body 110; the gas delivery body 140, the air delivery body 110 and the conical flow guide diffuser 12 are integrated into one structure; by arranging the gas delivery body 140, the air delivery body 110 and the conical flow guide diffuser 12 into one structure, the overall structural strength and sealing performance of the premixed gas delivery part 1 are greatly enhanced, the problems of gas leakage and flow channel misplacement caused by assembly errors or thermal deformation are effectively avoided, and the stability and reliability of the premixed process of gas and air are ensured; at the same time, the integrated structure reduces the thermal stress concentration under high temperature, improves the durability and service life of the burner, and simplifies the manufacturing and maintenance process.

[0042] Referring to Figures 1 to 7 In an embodiment, the premixed gas delivery part 1 is provided with a gas distribution chamber 14 communicating with the outer end of the gas delivery channel 41, and the inner end of each gas delivery hole 141 communicates with the gas distribution chamber 14; by arranging the gas distribution chamber 14 and making it communicate with the inner end of each gas delivery hole 141, it is ensured that the gas can be uniformly distributed and delivered into each gas delivery hole 141, so as to form multiple gas jets with balanced flow and pressure in the gas annular mixing chamber 15, significantly improving the uniformity of subsequent air premixing, providing reliable guarantee for forming stable and consistent conical thin film shaped premixed jets, and finally optimizing the sufficiency of combustion and the stability of flame.

[0043] Referring to Figures 1 to 7 In an embodiment, the outer diameter of the outer end of the conical flow guide diffuser 12 is greater than or equal to the inner diameter of the air distribution chamber 11 and less than the inner diameter of the premixing chamber 13; by setting the outer diameter of the outer end of the conical flow guide diffuser 12 to be greater than or equal to the inner diameter of the air distribution chamber 11 and less than the inner diameter of the premixing chamber 13, the size of the primary premixed gas annular nozzle 16 between the conical flow guide diffuser 12 and the wall of the premixing chamber 13 is accurately defined, it is ensured that the premixed gas can be uniformly ejected in the form of a conical thin film at high speed, the rigidity and stability of the flame are effectively improved, and the mixing efficiency with secondary air is optimized, so that the combustion is more sufficient.

[0044] Referring to Figures 1 to 7In an embodiment, the bottom of the conical flow guide diffuser 12 extends outside the opening of the premixing chamber 13, and the outer end of the conical flow guide diffuser 12 does not extend outside the outer end of the air delivery air disc 3 or the air delivery pipe 2; by extending the bottom of the conical flow guide diffuser 12 to the outside of the opening of the premixing chamber 13 but not beyond the outer end of the burner, the conical thin film premixed jet flow is effectively guided and protected from premature diffusion or interference, while ensuring that the premixed jet flow can mix with the secondary air jet at the optimal position and angle at the outlet of the burner, thereby strengthening the formation of multi-stage stable flame vortex and further improving the combustion stability and efficiency.

[0045] Referring to Figures 1 to 7 In an embodiment, the secondary air nozzles 31 are arranged in multiple numbers in the radial direction of the air delivery air disc 3; by arranging multiple secondary air nozzles 31 in the radial direction of the air delivery air disc 3, the coverage range of the secondary air jet and the intersection point with the primary premixed jet flow are significantly increased, thereby forming more levels and more uniform distribution of stable flame vortex, greatly extending the mixing path and strengthening the turbulent mixing effect, ensuring the sufficient combustion of fuel under low air-fuel ratio conditions, while effectively improving the stability of the flame and the adaptability of the burner to load changes.

[0046] Referring to Figures 1 to 7 In an embodiment, the air delivery holes 111 are arranged in the radial direction and are arranged in opposite staggered arrangement with the gas delivery holes 141; by arranging the air delivery holes 111 and the gas delivery holes 141 in opposite staggered arrangement in the radial direction, the primary air jet and the gas jet can collide and interweave at the optimal angle and position in the premixing chamber 13, greatly strengthening the turbulent shear and mixing effect, thereby significantly improving the uniformity and mixing efficiency of the premixed gas, laying a solid foundation for the formation of stable and uniform conical thin film premixed jet flow, and finally ensuring the sufficiency and stability of combustion under low air-fuel ratio conditions.

[0047] Referring to Figure 2 , Figure 3 , Figure 8 and Figure 9 In an embodiment, the air delivery pipe 2 is provided with an air inlet adjusting valve 6; by providing the air inlet adjusting valve 6, the air inlet amount can be adjusted according to process requirements.

[0048] Referring to Figure 2 , Figure 3 , Figure 8 and Figure 9In an embodiment, the air intake regulating valve 6 comprises a valve housing 61, a rotary valve core 62, and a regulating handle 63. The valve housing 61 is provided with a valve housing cavity on the inner side, and an air inlet 64 and an air outlet 65 communicating with both ends of the valve housing cavity. A rotary mounting seat 66 is arranged in the valve housing cavity, and the rotary mounting seat 66 is provided with a rotary movable cavity 661 arranged radially along the valve housing cavity. The rotary movable cavity 661 is provided with flow regulating holes 67 communicating with the air inlet 64 and the air outlet 65 at both ends, respectively. The rotary valve core 62 is rotatably arranged in the rotary movable cavity 661. The rotary valve core 62 is provided with a valve core cavity 621 arranged radially. The regulating handle 63 is arranged on the outer side of the valve housing 61 and is in transmission connection with the rotary valve core 62. By controlling the relative rotation of the rotary valve core 62, the air flow between the valve core cavity 621 and the valve housing cavity is adjusted, so as to adjust the air intake of the air delivery channel 21. The precise regulation and rapid response of the combustion air flow are realized. The rotation of the rotary valve core 62 in the rotary movable cavity 661 can infinitely adjust the alignment area of the valve core cavity 621 and the flow regulating holes 67, so as to realize the high-precision control of the air flow.

[0049] Referring to Figure 2 , Figure 3 , Figure 8 and Figure 9 In an embodiment, the air intake regulating valve 6 further comprises a valve cover 68. The valve cover 68 is provided with a avoiding port 69 corresponding to the regulating handle 63. The valve housing 61 is provided with a mounting port 611 opening radially and communicating with the rotary movable cavity 661. The rotary valve core 62 is mounted in the rotary movable cavity 661 through the mounting port 611. The inner end of the rotary valve core 62 is mounted in the rotary movable cavity 661 through a corrugated spring 613. The valve cover 68 is connected with the mounting port 611, so that the rotary valve core 62 is fixedly arranged in the rotary movable cavity 661. The valve cover 68 is in sealing cooperation with the outer end of the rotary valve core 62 through a sealing ring 614. By optimizing the sealing and mounting structure of the air intake regulating valve 6, the reliability and maintenance convenience of the equipment are significantly improved. The cooperation design of the valve cover 68 and the mounting port 611 realizes the quick disassembly and assembly of the rotary valve core 62. The elastic support of the corrugated spring 613 ensures the flexibility of the valve core rotation and automatically compensates the wear gap, so that the air intake regulating valve 6 still maintains the precise regulation performance after long-term use, and the product has good reliability.

[0050] Referring to Figure 2 , Figure 3 , Figure 8 and Figure 9In an embodiment, the adjusting handle 63 is configured with a valve position pointer 615; the configuration of the valve position pointer 615 enables the operator to intuitively and accurately read the opening position of the current intake adjusting valve 6, not only realizing visual adjustment of the air-fuel ratio, but also ensuring consistency of repeated adjustment through scale identification; the design is linked with the adjusting handle 63 through mechanical indication, so as to facilitate the worker to quickly adjust the intake adjusting valve 6 to the preset optimal working point, and significantly improve the adjustment accuracy and operation reliability of the combustion system under the low air-fuel ratio working condition.

[0051] According to the disclosure and teaching of the above description, those skilled in the art of the present application can also make changes and modifications to the above embodiments. Therefore, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the present application should fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. Low air-fuel ratio roller kiln burner, characterized by: include: Igniter; The air delivery pipe is provided with an air delivery channel located on the inner side, and the outer end of the air delivery channel is opened to form a flame nozzle; A premixed gas delivery portion is provided in the air delivery channel, and is provided with an air distribution chamber located at the inner end, a premixing chamber located outside the air distribution chamber and open at the outer end, and a conical guide diffuser. An air delivery hole communicating with the air delivery channel is provided inside the air distribution chamber. A plurality of axially arranged gas delivery holes and a gas annular mixing chamber are provided in the premixed gas delivery portion around the outer side of the air distribution chamber. Each gas delivery hole is communicated with the premixing chamber through the gas annular mixing chamber, and the outer ends of each gas delivery hole are communicated with each other through the gas annular mixing chamber. The conical guide diffuser is provided in the premixing chamber and is concentric with the air distribution chamber. The outer diameter of the conical guide diffuser gradually increases along the outer direction, and a primary premixed gas annular nozzle is formed between the inner periphery of the premixing chamber opening and the outer periphery of the bottom of the conical guide diffuser. The air delivery fan disk is connected around the outer periphery of the premixed gas delivery part and is provided with a plurality of secondary air nozzles arranged obliquely along the center line of the premixed gas delivery part; The gas delivery hole is used to deliver the gas jet axially to the premixing chamber after it flows annularly through the gas annular mixing chamber and is premixed with the primary air jet delivered from the air distribution chamber, and then ejected from the primary premixed gas annular nozzle to form a conical film-shaped primary premixed jet and burn, and then intersect with the secondary air jet generated by the secondary air nozzle on the air delivery wind disk at a certain angle to form a multi-stage flame-stabilizing vortex. The secondary air jet generated by the secondary air nozzle is also used to extend the mixing path of the primary premixed jet and the secondary air jet during combustion.

2. The low air-fuel ratio roller kiln burner according to claim 1, characterized in that: An annular gas spray slot is provided at the outer end of the annular gas mixing chamber, and the ring width of the annular gas spray slot is smaller than the ring width of the annular gas mixing chamber.

3. The low air-fuel ratio roller kiln burner according to claim 1, characterized in that: The conical flow-guiding diffuser is connected to the inner end of the air distribution chamber through a connecting column. The connecting column is cylindrical and has an outer diameter smaller than that of the conical flow-guiding diffuser.

4. The low air-fuel ratio roller kiln burner according to claim 1, characterized in that: The outer diameter of the end portion of the conical guide diffuser is greater than or equal to the inner diameter of the air distribution chamber and smaller than the inner diameter of the premixing chamber; The bottom of the conical guide diffuser extends out of the outside of the premixing chamber opening, and the outer end of the conical guide diffuser does not extend out of the air delivery fan disc or the outer end of the air delivery pipe.

5. The low air-fuel ratio roller kiln burner according to claim 1, characterized in that: A plurality of secondary air nozzles are provided along the radial direction of the air delivery fan disc.

6. The low air-fuel ratio roller kiln burner according to claim 1, characterized in that: The air delivery holes are arranged radially and staggered relative to the gas delivery holes.

7. The low air-fuel ratio roller kiln burner according to any one of claims 1 to 6, characterized in that: The air delivery pipe is equipped with an air intake regulating valve; The air intake regulating valve includes a valve housing, a rotary valve core, and an adjusting handle. The valve housing is provided with a valve housing cavity located on the inner side and an air inlet and an air outlet connected to both ends of the valve housing cavity. A rotating mounting seat is provided in the valve housing cavity. The rotating mounting seat is provided with a rotating active cavity arranged radially along the valve housing cavity. Flow regulating holes connecting the air inlet and the air outlet are respectively provided at both ends of the rotating active cavity. The rotary valve core can be rotatably placed in the rotating active cavity. A valve core cavity arranged radially is provided in the rotary valve core. The adjusting handle is located on the outer side of the valve housing and is transmission-connected to the rotary valve core. By controlling the relative rotation of the rotary valve core, the air flow rate of the valve core cavity and the valve housing cavity is adjusted, thereby adjusting the air intake volume of the air delivery channel.

8. The low air-fuel ratio roller kiln burner according to claim 7, characterized in that: The air intake regulating valve also includes a valve cover, which is provided with a avoidance port corresponding to the regulating handle, and the valve housing is provided with an assembly port which is radially open and connected to the rotating movable chamber, the rotary valve core is assembled in the rotating movable chamber through the assembly port, the inner end of the rotary valve core is assembled in the rotating movable chamber through a corrugated spring, the valve cover is connected to the assembly port so that the rotary valve core is placed and fixed in the rotating movable chamber, and the valve cover is sealed with the outer end of the rotary valve core through a sealing ring.

9. The low air-fuel ratio roller kiln burner according to claim 7, characterized in that: The regulating handle is provided with a valve position pointer.

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