Low air pressure low air ratio burner

Abstract

The utility model belongs to the technical field of combustor, specifically relates to low air pressure low air -fuel ratio combustor, low air pressure low air -fuel ratio combustor of the utility model, through the collaborative design of premix gas delivery part and combustion gas delivery air -supply disc, realized the high -efficient stable combustion under the condition of low air pressure state and low air -fuel ratio (alpha < 1), gas delivery hole transports gas jet and the first air jet of first air jet input, under the cooperation of conical guide diffusion body and first premix gas annular jet, form the first premix jet of conical film shape, form multistage stable flame vortex in combination with the secondary air jet of secondary air jet generation, significantly improve flame rigidity and combustion fullness, gas distribution chamber and radial first air jet design enhance the premix effect of gas and air, reduce the risk of carbon deposition, comprehensively solve the problems, such as high flue gas heat loss, easy coking shutdown and poor pressure adaptability of traditional combustor, greatly reduce the frequency of cleaning.

Description

Technical Field

[0001] This utility model belongs to the field of burner technology, specifically relating to a low air pressure, low air-fuel ratio burner. Background Technology

[0002] In the production cost structure of ceramic industrial kilns, fuel expenditure accounts for a significant proportion of 60%-80%, making the profitability of enterprises highly susceptible to fluctuations in fuel market prices. Existing combustion systems face multiple technical bottlenecks when operating under low excess air conditions (α<1): Firstly, they exhibit low combustion efficiency, unstable flame morphology, and insufficient thermal radiation intensity, accompanied by significant energy loss from high-temperature flue gas; secondly, they show a severe tendency to coking, with accelerated carbon deposition rates on the combustion chamber and fire tube inner walls, necessitating increased maintenance frequency and severely restricting the continuous operation efficiency of the production line; furthermore, they suffer from poor adaptability to air pressure, specifically being sensitive to pressure fluctuations and unable to operate stably at ultra-low pressures (e.g., below 500 Pa), limiting energy-saving potential. Utility Model Content

[0003] The purpose of this invention is to overcome the problems of incomplete combustion of gas in existing roller kiln burners under low air excess coefficient conditions, which leads to poor flame rigidity and easy carbon accumulation, and to provide a low air pressure and low air-fuel ratio burner that can achieve complete combustion under low air excess coefficient conditions.

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

[0005] A low air pressure, low air-fuel ratio burner includes an igniter, a combustion gas delivery section, a premixed gas delivery section, and a combustion gas delivery fan.

[0006] The combustion-supporting gas delivery unit is equipped with an inner combustion-supporting gas delivery channel, and the outer end of the combustion-supporting gas delivery channel opens to form a flame nozzle.

[0007] The premixed gas delivery unit, located within the combustion gas delivery channel, includes a premixed gas delivery body and a conical guide diffuser. The premixed gas delivery body includes a gas distribution chamber at its inner end and a premixed chamber with an opening at its outer end. The gas distribution chamber has gas delivery holes that connect to the premixed chamber and are arranged axially. The periphery of the premixed gas delivery body has several primary air nozzles that connect the combustion gas delivery channel and the premixed chamber. The conical guide diffuser is located within the premixed chamber and is connected to the inner side of the premixed chamber via a connecting column. The outer diameter of the conical guide diffuser gradually increases in the outer direction. A primary premixed gas annular nozzle is formed between the inner periphery of the premixed chamber opening and the outer periphery of the bottom of the conical guide diffuser.

[0008] The combustion-supporting gas delivery fan is connected around the outer periphery of the premixed gas delivery body and is provided with several secondary air nozzles for mixing with the primary premixed jet ejected from the primary premixed gas annular nozzle.

[0009] Compared with existing technologies, the low air pressure and low air-fuel ratio burner of this invention achieves efficient and stable combustion under low air pressure and low air-fuel ratio (α<1) conditions through the coordinated design of the premixed gas delivery section and the auxiliary gas delivery fan. The gas delivery hole delivers the gas jet and the primary air jet input from the primary air nozzle. Under the cooperation of the conical guide diffuser and the primary premixed gas annular nozzle, a conical film-shaped primary premixed jet is formed. Combined with the secondary air jet generated by the secondary air nozzle, a multi-stage flame stabilizing vortex is formed, which significantly improves the flame rigidity and combustion completeness. The gas distribution chamber and radial primary air nozzle design enhance the premixing effect of gas and air, reducing the risk of carbon buildup. It comprehensively solves the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of traditional burners. Compared with traditional burners, it can reduce fuel consumption by more than 15% and greatly reduce the frequency of coking.

[0010] Furthermore, the secondary air nozzle is oriented along the axial direction of the premixed gas delivery section; by arranging the secondary air nozzle along the axial direction, it can be mixed more directly with the primary premixed jet, enhancing combustion stability and improving flame rigidity, while further reducing the risk of carbon buildup.

[0011] Alternatively, the combustion-supporting gas delivery fan disc is a conical disc structure, with a plurality of secondary air nozzles arranged circumferentially on the combustion-supporting gas delivery fan disc. The orientation of the secondary air nozzles is perpendicular to the inner conical surface of the combustion-supporting gas delivery fan disc, so that they are arranged at an angle along the center line of the premixed gas delivery section. By setting the secondary air nozzles perpendicular to the inner conical surface of the conical fan disc, the secondary air jet is injected into the combustion zone in an inclined direction, enhancing the swirling mixing effect with the primary premixed jet, improving combustion efficiency and optimizing flame morphology, while also improving combustion stability under low air pressure.

[0012] Furthermore, the premixed gas conveying unit and the combustion-supporting gas conveying fan are an integral structure, preferably manufactured by integral molding; this arrangement facilitates product production and assembly.

[0013] Furthermore, a secondary premixed gas annular nozzle is formed between the gas-supporting gas conveying fan and the inner peripheral wall of the gas-supporting gas conveying section, which is inclined along the center line of the premixed gas conveying section. With this setting, the secondary premixed gas annular nozzle extends the mixing path between the primary premixed jet and the secondary air jet during combustion, making the gas combustion more complete and solving the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of traditional burners.

[0014] Furthermore, the bottom surface of the conical guide diffuser extends out of or is located at the opening of the premixing chamber, and the inner circumference of the premixing chamber opening is provided with a first guide slope arranged in an outward direction. With this configuration, the bottom surface of the conical guide diffuser extends out of or is located at the opening of the premixing chamber, and in conjunction with the outwardly inclined first guide slope structure, the primary premixed gas forms a conical thin-layer jet with a controllable expansion angle when it is ejected. This ensures sufficient premixing effect between the secondary air jet and the primary premixed jet, and precisely controls the flame diffusion pattern through the guiding effect of the first guide slope structure. This design optimizes the airflow expansion angle, reduces the velocity of the primary premixed jet while enhancing the radial coverage, making the flame pattern more stable and the heat distribution more uniform. It effectively avoids flame drift or local high temperature problems caused by excessive airflow diffusion. At the same time, the Venturi effect generated by the inclined first guide slope structure can improve the gas entrainment capacity under low pressure conditions, further enhancing the stability and combustion efficiency of the burner under ultra-low air pressure conditions.

[0015] Furthermore, the inner circumference of the opening of the combustion-supporting gas delivery section is provided with a second guide slope that is inclined inward on the outside of the combustion-supporting gas delivery fan. With this arrangement, the second guide slope forms a contracting guide channel around the flame by means of the inward inclined structural design, so that the secondary air and the combustion flue gas produce a centripetal convergence effect. This not only strengthens the internal circulation and flame stabilization effect of the high-temperature flue gas, but also effectively increases the temperature of the flame core area through airflow compression.

[0016] Furthermore, the primary air nozzles are arranged in at least two rows along the axial direction in the premixing chamber. With this arrangement, the multiple rows of axially arranged primary air nozzles form a stepped air distribution structure, which allows the combustion air to be gradually mixed with the fuel gas in stages and regions. This avoids the problem of local overcooling caused by single-point centralized air distribution and extends the residence time of the fuel gas in the premixing chamber through staged combustion. This design establishes a basic combustion zone through upstream nozzles and supplements the burnout air through downstream nozzles, forming a laminar combustion environment with a controllable temperature gradient in the premixing chamber, ensuring that the optimal air-fuel ratio is maintained even under low air pressure conditions.

[0017] Furthermore, a conical flow guide diffuser is disposed in the premixing chamber and connected to the inner end of the premixing chamber via a connecting column. The connecting column is cylindrical with an outer diameter smaller than that of the conical flow guide diffuser. The outer diameter of the conical flow guide diffuser gradually increases along the outer direction. Multiple gas delivery holes are arranged around the connecting column. With this arrangement, the conical flow guide diffuser is supported by the cylindrical connecting column, and its connection structure size is reduced. At the same time, in conjunction with the surrounding gas delivery holes, the gas jet diffuses more evenly and is fully premixed with the primary air, thereby improving combustion efficiency and reducing the risk of local high-temperature carbon buildup.

[0018] Furthermore, the gas distribution chamber has an opening at its rear end, which is connected to a main gas delivery unit. The main gas delivery unit has a main gas delivery channel that communicates with the gas distribution chamber and is used to supply gas to the gas distribution chamber. The auxiliary gas delivery unit is equipped with an air intake regulating valve. With this configuration, the air intake volume can be adjusted according to process requirements by setting the air intake regulating valve.

[0019] Furthermore, the intake regulating valve includes a valve body, a rotary valve core, and an adjusting handle. The valve body has an inner valve body cavity and an air inlet and an air outlet communicating with both ends of the valve body cavity. A rotating mounting seat is provided inside the valve body cavity, and the rotating mounting seat has a rotating movable cavity arranged radially along the valve body cavity. Flow regulating holes communicating with the air inlet and air outlet are respectively provided at both ends of the rotating movable cavity. The rotary valve core is rotatably placed inside the rotating movable cavity, and the rotary valve core has a valve core cavity arranged radially. The adjusting handle is located outside the valve body and is drivenly connected to the rotary valve core. By controlling the relative rotation of the rotary valve core, the airflow between the valve core cavity and the valve body cavity is adjusted, thereby adjusting the air intake volume of the combustion air delivery channel. Through this setting, precise control and rapid response of the combustion air flow are achieved: the rotation of the rotary valve core in the rotating movable cavity can infinitely adjust the alignment area between the valve core cavity and the flow regulating hole, achieving high-precision control of the air flow.

[0020] Furthermore, the intake regulating valve also includes a valve cover with a clearance opening corresponding to the regulating handle. The valve housing has a radially open assembly port that communicates with the rotating chamber. The rotary valve core is assembled into the rotating chamber through the assembly port. The inner end of the rotary valve core is assembled into the rotating chamber via a corrugated spring. The valve cover is connected to the assembly port to fix the rotary valve core in the rotating chamber. The valve cover is sealed to the outer end of the rotary valve core via a sealing ring. This design optimizes the sealing and assembly structure of the intake regulating valve, significantly improving the reliability and ease of maintenance of the equipment. The fit between the valve cover and the assembly port enables quick assembly and disassembly of the rotary valve core. The elastic support of the corrugated spring ensures the flexibility of the valve core rotation and automatically compensates for wear gaps, allowing the valve to maintain precise control performance even after long-term use, resulting in high product reliability.

[0021] Furthermore, the adjusting handle is equipped with a valve position pointer; this configuration allows the operator to intuitively and accurately read the current opening position of the intake regulating valve, not only achieving visual adjustment of the air-fuel ratio, but also ensuring consistency of repeated adjustments through scale markings; this design, through the linkage between the mechanical indicator and the adjusting handle, facilitates the operator to quickly adjust the valve to the preset optimal operating point, significantly improving the adjustment accuracy and operational reliability of the combustion system under low air-fuel ratio conditions. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of a low-air-pressure, low-air-fuel-ratio burner.

[0023] Figure 2 This is a cross-sectional view of a low-air-pressure, low-air-fuel-ratio burner located at the intake regulating valve.

[0024] Figure 3 This is a cross-sectional view of a low-air-pressure, low-air-fuel-ratio burner located in the premixed gas delivery section.

[0025] Figure 4 This is a schematic diagram of the premixed gas delivery section and the combustion-supporting gas delivery fan coil unit.

[0026] Figure 5 This is a cross-sectional view of the premixed gas delivery section located at the primary air nozzle.

[0027] Figure 6 Cross-section of the intake regulating valve Figure 1 .

[0028] Figure 7 Cross-section of the intake regulating valve Figure 2 .

[0029] Labeling Explanation: Igniter 5, Combustion-supporting gas delivery section 2, Premixed gas delivery section 1, Combustion-supporting gas delivery fan 3, Combustion-supporting gas delivery channel 21, Flame nozzle 22, Premixed gas delivery body 11, Conical guide diffuser 12, Gas distribution chamber 13, Premixing chamber 14, Gas delivery hole 111, Primary air nozzle 141, Connecting column 121, Primary premixed gas annular nozzle 15, Main gas delivery section 4, Main gas delivery channel 41, Secondary air nozzle 31, Secondary premixed gas annular nozzle 32, First guide slope 16, Secondary guide slope 23, Inlet regulating valve 6, Valve body 61, Rotary valve core 62, Adjusting handle 63, Air inlet 64, Air outlet 65, Rotary mounting base 66, Rotary movable chamber 661, Flow regulating hole 67, Valve core chamber 621, Valve cover 68, Clearance port 69, Assembly port 611, Corrugated spring 613, Sealing ring 614, Valve position pointer 615. Detailed Implementation

[0030] The specific embodiments of this utility model are described below with reference to the accompanying drawings. In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model 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 of this utility model.

[0031] See Figures 1 to 7The low air pressure and low air-fuel ratio burner of this utility model includes an igniter 5, a combustion gas delivery unit 2, a premixed gas delivery unit 1, and a combustion gas delivery fan 3.

[0032] The combustion gas delivery unit 2 is provided with a combustion gas delivery channel 21 located on the inner side, and the outer end of the combustion gas delivery channel 21 opens to form a flame nozzle 22.

[0033] The premixed gas delivery unit 1 is located in the combustion gas delivery channel 21 and includes a premixed gas delivery body 11 and a conical guide diffuser 12. The premixed gas delivery body 11 includes a gas distribution chamber 13 located at the inner end and a premixed chamber 14 with an opening at the outer end. The gas distribution chamber 13 is provided with a gas delivery hole 111 that connects to the premixed chamber 14 and is arranged axially. The outer periphery of the premixed gas delivery body 11 is provided with a plurality of primary air nozzles 141 that connect the combustion gas delivery channel 21 and the premixed chamber 14 and are arranged radially. The conical guide diffuser 12 is located in the premixed chamber 14 and is connected to the inner side of the premixed chamber 14 through a connecting column 121. The outer diameter of the conical guide diffuser 12 gradually increases in the outer direction. A primary premixed gas annular nozzle 15 is formed between the inner periphery of the opening of the premixed chamber 14 and the outer periphery of the bottom of the conical guide diffuser 12.

[0034] The combustion gas conveying fan 3 is connected around the outer periphery of the premixed gas conveying body 11 and is provided with a number of secondary air nozzles 31 for mixing with the primary premixed jet ejected from the primary premixed gas annular nozzle 15.

[0035] The gas delivery hole 111 is used to deliver the gas jet axially to the premixing chamber 14 and premix it with the primary air jet radially input from the primary air nozzle 141. After premixing, the gas jet is ejected from the primary premixed gas annular nozzle 15 to form a conical film-shaped primary premixed jet and is burned. Then, it intersects with the secondary air jet generated by the secondary air nozzle 31 on the auxiliary gas delivery fan 3 at a certain angle to form a multi-stage flame stabilizing vortex. The tertiary air jet generated by the secondary premixed gas annular nozzle 32 is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion.

[0036] Compared with existing technologies, the low air pressure and low air-fuel ratio burner of this invention achieves efficient and stable combustion under low air pressure and low air-fuel ratio (α<1) conditions through the coordinated design of the premixed gas delivery section 1 and the auxiliary gas delivery fan 3. The gas delivery hole 111 delivers the gas jet and the primary air jet input by the primary air nozzle 141. Under the cooperation of the conical guide diffuser 12 and the primary premixed gas annular nozzle 15, a conical film-shaped primary premixed jet is formed. Combined with the secondary air jet generated by the secondary air nozzle 31, a multi-stage flame stabilizing vortex is formed, which significantly improves the flame rigidity and combustion completeness. The gas distribution chamber 13 and the radial primary air nozzle 141 are designed to enhance the premixing effect of gas and air and reduce the risk of carbon buildup. It comprehensively solves the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of traditional burners. Compared with traditional burners, it can reduce fuel consumption by more than 15% and greatly reduce the frequency of coking.

[0037] See Figures 1 to 5 In one embodiment, the secondary air nozzle 31 is oriented along the axial direction of the premixed gas delivery section 1. By arranging the secondary air nozzle 31 axially, it can be mixed more directly with the primary premixed jet, thereby enhancing combustion stability and improving flame rigidity, while further reducing the risk of carbon buildup.

[0038] Alternatively, in this embodiment, the combustion-supporting gas delivery fan 3 is a conical disc structure, and a plurality of secondary air nozzles 31 are arranged circumferentially on the combustion-supporting gas delivery fan 3. The orientation of the secondary air nozzles 31 is perpendicular to the inner conical surface of the combustion-supporting gas delivery fan 3, so that they are arranged at an angle along the center line of the premixed gas delivery section 1. With this arrangement, by setting the secondary air nozzles 31 perpendicular to the inner conical surface of the conical fan, the secondary air jet is injected into the combustion zone in an inclined direction, which enhances the swirling mixing effect with the primary premixed jet, improves combustion efficiency and optimizes flame morphology, and improves combustion stability under low air pressure. Moreover, the conical disc-shaped combustion air supply fan 3 forms a uniformly distributed inclined secondary air jet through the circumferentially arranged secondary air nozzles 31. This not only enhances the radial mixing effect of the primary premixed jet and the secondary air jet, but also creates a stable high-temperature vortex zone in the combustion area. This strengthens the flame rigidity and extends the gas residence time, enabling complete combustion even under ultra-low air pressure conditions. At the same time, the centrifugal effect generated by the conical disc-shaped structure can effectively prevent carbon soot from depositing at the nozzle, improving the burner's anti-carbon deposit capability and adaptability to low-pressure conditions.

[0039] In a further embodiment, several of the secondary air nozzles 31 are inclined in the circumferential direction along the relative radial direction, so that the centrifugal effect of the generated premixed airflow can effectively prevent carbon soot from depositing at the nozzle, further improving the burner's anti-carbon deposit capability and low-pressure operating condition adaptability.

[0040] See Figures 1 to 5 In one embodiment, the premixed gas conveying unit 1 and the combustion-supporting gas conveying fan 3 are an integral structure, preferably manufactured by integral molding; this arrangement facilitates product production and assembly.

[0041] See Figures 1 to 5 In one embodiment, a secondary premixed gas annular nozzle 32 is formed between the combustion gas delivery fan 3 and the inner peripheral wall of the combustion gas delivery section 2, which is inclined along the center line of the premixed gas delivery section 1. With this arrangement, the secondary premixed gas annular nozzle 32 extends the mixing path between the primary premixed jet and the secondary air jet during combustion, making the combustion of the gas more complete and solving the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of traditional burners.

[0042] See Figures 1 to 5 In one embodiment, the bottom surface of the conical guide diffuser 12 extends out of or is located at the opening of the premixing chamber 14. The inner circumference of the opening of the premixing chamber 14 is provided with a first guide slope 16 arranged in an outward direction. With this arrangement, the bottom surface of the conical guide diffuser 12 extends out of or is located at the opening of the premixing chamber 14. Combined with the outwardly inclined first guide slope 16, this allows the primary premixed gas to form a conical thin-layer jet with a controllable expansion angle upon ejection, ensuring sufficient mixing of the secondary air jet and the primary premixed jet. The premixing effect is further enhanced by the precise control of the flame diffusion pattern through the guiding effect of the first guide slope 16 structure. This design optimizes the airflow expansion angle, reduces the velocity of the primary premixed jet while enhancing the radial coverage, making the flame pattern more stable and the heat distribution more uniform. It effectively avoids flame drift or local high temperature problems caused by excessive airflow diffusion. At the same time, the Venturi effect generated by the inclined first guide slope 16 structure can improve the gas entrainment capacity under low pressure conditions, further enhancing the stability and combustion efficiency of the burner under ultra-low air pressure conditions.

[0043] See Figures 1 to 5 In one embodiment, the inner periphery of the opening of the combustion-supporting gas delivery section 2 is provided with a second guide slope 23 that is inclined inward on the outside of the combustion-supporting gas delivery fan 3. With this arrangement, the second guide slope 23 forms a contraction guide channel around the flame by means of the inward inclined structural design, so that the secondary air and the combustion flue gas generate a centripetal convergence effect, which not only strengthens the internal circulation and flame stabilization effect of the high-temperature flue gas, but also effectively increases the temperature of the flame core area through airflow compression.

[0044] See Figures 1 to 5In one embodiment, the primary air nozzles 141 are arranged in at least two or more rows along the axial direction in the premixing chamber 14. With this arrangement, the multiple rows of axially arranged primary air nozzles 141 form a stepped air distribution structure, which allows the combustion air to be gradually mixed with the gas in stages and regions. This avoids the problem of local overcooling caused by single-point centralized air distribution, and extends the residence time of the gas in the premixing chamber 14 through staged combustion. This design establishes a basic combustion zone through upstream nozzles and supplements the burnout air through downstream nozzles, forming a laminar combustion environment with a controllable temperature gradient in the premixing chamber 14, ensuring that the optimal air-fuel ratio is maintained even under low air pressure conditions.

[0045] See Figures 1 to 5 In one embodiment, a conical diffuser 12 is disposed in a premixing chamber 14 and connected to the inner end of the premixing chamber 14 via a connecting post 121. The connecting post 121 is cylindrical and its outer diameter is smaller than that of the conical diffuser 12. The outer diameter of the conical diffuser 12 gradually increases along the outer direction. Multiple gas delivery holes 111 are provided around the connecting post 121. With this arrangement, the conical diffuser 12 is supported by the cylindrical connecting post 121 and its connection structure size is reduced. At the same time, in conjunction with the surrounding gas delivery holes 111, the gas jet diffuses more evenly and is fully premixed with primary air, thereby improving combustion efficiency and reducing the risk of local high-temperature carbon buildup.

[0046] See Figures 1 to 5 In one embodiment, the gas distribution chamber 13 has an opening at its rear end, and the rear opening of the gas distribution chamber 13 is connected to a main gas delivery section 4. The main gas delivery section 4 is provided with a main gas delivery channel 41 that communicates with the gas distribution chamber 13. The main gas delivery channel 41 is used to supply gas to the gas distribution chamber 13. The auxiliary gas delivery section 2 is equipped with an air intake regulating valve 6. With this configuration, the air intake volume can be adjusted according to process requirements by setting the air intake regulating valve 6.

[0047] See Figure 6 and Figure 7In one embodiment, the intake regulating valve 6 includes a valve housing 61, a rotary valve core 62, and an adjusting handle 63. The valve housing 61 has an inner valve housing cavity and an air inlet 64 and an air outlet 65 communicating with both ends of the valve housing cavity. The air outlet 65 communicates with the combustion-supporting gas delivery channel 21. A rotary mounting base 66 is provided inside the valve housing cavity. The rotary mounting base 66 has a rotary movable cavity 661 arranged radially along the valve housing cavity. Flow regulating holes 67 communicating with the air inlet 64 and the air outlet 65 are respectively provided at both ends of the rotary movable cavity 661. The rotary valve core 62 is rotatably mounted on the rotary valve core 63. Within the movable cavity 661, the rotary valve core 62 has a radially arranged valve core cavity 621. The adjusting handle 63 is located outside the valve housing 61 and is connected to the rotary valve core 62 in a transmission manner. By controlling the relative rotation of the rotary valve core 62, the airflow between the valve core cavity 621 and the valve housing cavity is adjusted, thereby adjusting the air intake of the combustion air delivery channel 21. Through this arrangement, precise control and rapid response of the combustion air flow are achieved: the rotation of the rotary valve core 62 within the rotating movable cavity 661 can infinitely adjust the alignment area between the valve core cavity 621 and the flow adjustment hole 67, achieving high-precision control of the air flow.

[0048] See Figure 6 and Figure 7 In a further embodiment, the intake regulating valve 6 further includes a valve cover 68, the valve cover 68 having a clearance opening 69 corresponding to the regulating handle 63, and the valve housing 61 having a mounting port 611 that is radially open and communicates with the rotating movable cavity 661. The rotary valve core 62 is mounted in the rotating movable cavity 661 through the mounting port 611, and the inner end of the rotary valve core 62 is mounted in the rotating movable cavity 661 through a bellows spring 613. The valve cover 68 is connected to the mounting port 611 to fix the rotary valve core 62 in the rotating movable cavity 661. Inside the movable chamber 661, the valve cover 68 is sealed to the outer end of the rotary valve core 62 via a sealing ring 614. This arrangement, by optimizing the sealing and assembly structure of the intake regulating valve 6, significantly improves the reliability and ease of maintenance of the equipment. The fit design between the valve cover 68 and the assembly port 611 enables quick assembly and disassembly of the rotary valve core 62. The elastic support of the bellows spring 613 ensures the flexibility of the valve core rotation and automatically compensates for wear gaps, allowing the valve to maintain precise control performance even after long-term use, resulting in high product reliability.

[0049] See Figure 6 and Figure 7In a further embodiment, the adjusting handle 63 is equipped with a valve position pointer 615. This configuration allows the operator to intuitively and accurately read the current opening position of the intake regulating valve 6, achieving not only visual adjustment of the air-fuel ratio but also ensuring consistency of repeated adjustments through scale markings. This design, through the linkage between the mechanical indicator and the adjusting handle 63, facilitates the operator to quickly adjust the valve to the preset optimal operating point, significantly improving the adjustment accuracy and operational reliability of the combustion system under low air-fuel ratio conditions.

[0050] When the low air pressure and low air-fuel ratio burner of this utility model is working, the gas delivery hole 111 is used to deliver the gas jet axially to the premixing chamber 14 and premix it with the primary air jet radially input from the primary air nozzle 141. After premixing, the gas jet is ejected from the primary premixed gas annular nozzle 15 to form a conical film-shaped primary premixed jet and is burned. Then, it intersects with the secondary air jet generated by the secondary air nozzle 31 on the auxiliary gas delivery fan 3 at a certain angle to form a multi-stage flame stabilizing vortex. The tertiary air jet generated by the secondary premixed gas annular nozzle 32 is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion.

[0051] This invention relates to a low-air-pressure, low-air-fuel-ratio burner. Through the coordinated design of the premixed gas delivery unit 1 and the combustion-supporting gas delivery fan 3, it achieves efficient and stable combustion under low air-pressure and low air-fuel ratio (α<1) conditions. The gas delivery hole 111 delivers a gas jet, which, together with the primary air jet input from the primary air nozzle 141, forms a conical thin-film primary premixed jet in cooperation with the conical guide diffuser 12 and the primary premixed gas annular nozzle 15. This, combined with the inclined secondary air jet generated by the secondary air nozzle 31, forms a multi-stage flame-stabilizing vortex, significantly improving flame rigidity and combustion completeness. The gas distribution chamber 13 and the radial primary air nozzle 141 are designed to enhance the premixing effect of gas and air, reducing the risk of carbon buildup. The tertiary air jet generated by the secondary premixed gas annular nozzle 32 is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion. Together with the inclined secondary air nozzle 31, it forms a pressure adaptive structure, enabling the burner to maintain flame stability even under ultra-low pressure. This comprehensively solves the problems of high flue gas heat loss, easy coking and shutdown, and poor pressure adaptability of traditional burners. Compared with traditional burners, it can reduce fuel consumption by more than 15% and greatly reduce the frequency of coking.

[0052] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. 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 this utility model.

Claims

1. A low air pressure, low air-fuel ratio burner, characterized in that, include: The combustion-supporting gas delivery unit is equipped with an inner combustion-supporting gas delivery channel, and the outer end of the combustion-supporting gas delivery channel opens to form a flame nozzle. The premixed gas delivery unit, located within the combustion-supporting gas delivery channel, includes a premixed gas delivery body and a conical guide diffuser. The premixed gas delivery body includes a gas distribution chamber located at the inner end and a premixing chamber with an opening at the outer end. The gas distribution chamber is provided with a gas delivery hole communicating with the premixing chamber. The periphery of the premixed gas delivery body is provided with several primary air nozzles communicating with the combustion-supporting gas delivery channel and the premixing chamber. The conical guide diffuser is located within the premixing chamber and is connected to the premixing chamber via a connecting column. The outer diameter of the conical guide diffuser gradually increases along the outer direction. 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 combustion-supporting gas delivery fan is connected around the outer periphery of the premixed gas delivery body and is provided with several secondary air nozzles for mixing with the primary premixed jet ejected from the primary premixed gas annular nozzle.

2. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, The secondary air nozzle is oriented along the axial direction of the premixed gas conveying section. Alternatively, the combustion-supporting gas conveying fan can be a conical disc structure, with a plurality of secondary air nozzles arranged circumferentially on the combustion-supporting gas conveying fan. The orientation of the secondary air nozzles is perpendicular to the inner conical surface of the combustion-supporting gas conveying fan, so that they are arranged at an angle along the center line of the premixed gas conveying section.

3. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, The premixed gas delivery section and the combustion-supporting gas delivery fan are an integrated structure.

4. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, A secondary premixed gas annular nozzle is formed between the gas-supporting gas conveying fan and the inner peripheral wall of the gas-supporting gas conveying section, and is arranged at an inclination along the center line of the premixed gas conveying section.

5. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, The bottom surface of the conical flow diffuser extends out of or is located at the opening of the premixing chamber, and the inner periphery of the premixing chamber opening is provided with a first flow guide slope arranged in an outward direction.

6. The low air pressure, low air-fuel ratio burner according to claim 4, characterized in that, The inner periphery of the opening of the gas-supporting conveying section is provided with a second guide slope that is inclined inward on the outside of the gas-supporting conveying fan.

7. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, The primary air nozzles are located in the premixing chamber and are arranged in at least two rows along the axial direction.

8. The low air pressure, low air-fuel ratio burner according to claim 1, characterized in that, A conical flow guide diffuser is disposed in the premixing chamber and connected to the inner end of the premixing chamber via a connecting column. The connecting column is cylindrical and its outer diameter is smaller than that of the conical flow guide diffuser. The outer diameter of the conical flow guide diffuser gradually increases along the outer direction. Multiple gas delivery holes are provided around the connecting column.

9. The low air pressure, low air-fuel ratio burner according to any one of claims 1 to 8, characterized in that, The gas distribution chamber has an opening at the rear end, which is connected to a main gas delivery unit. The main gas delivery unit has a main gas delivery channel that communicates with the gas distribution chamber and is used to supply gas to the gas distribution chamber. The combustion-supporting gas delivery unit is equipped with an air intake regulating valve; The intake regulating valve includes a valve body, a rotary valve core, and an adjusting handle. The valve body has an inner valve body cavity and an air inlet and an air outlet communicating with both ends of the valve body cavity. A rotating mounting seat is provided inside the valve body cavity. The rotating mounting seat has a rotating movable cavity arranged radially along the valve body cavity. Flow regulating holes communicating with the air inlet and air outlet are respectively provided at both ends of the rotating movable cavity. The rotary valve core is rotatably placed inside the rotating movable cavity. The rotary valve core has a valve core cavity arranged radially. The adjusting handle is located outside the valve body and is kinetically connected to the rotary valve core. By controlling the relative rotation of the rotary valve core, the airflow between the valve core cavity and the valve body cavity is adjusted, thereby adjusting the air intake volume of the combustion gas delivery channel.

10. The low air pressure, low air-fuel ratio burner according to claim 9, characterized in that, The intake regulating valve also includes a valve cover, which has a clearance opening corresponding to the regulating handle. The valve housing has an assembly port that is radially open and communicates with the rotating movable cavity. The rotary valve core is assembled in the rotating movable cavity through the assembly port. The inner end of the rotary valve core is assembled in the rotating movable cavity through a corrugated spring. The valve cover is connected to the assembly port to fix the rotary valve core in the rotating movable cavity. The valve cover is sealed to the outer end of the rotary valve core through a sealing ring.

Images