Low air pressure, low air-fuel ratio roller kiln burner

Abstract

This invention belongs to the field of burner technology, specifically relating to a low-air-pressure, low-air-fuel-ratio roller kiln burner. The low-air-pressure, low-air-fuel-ratio roller kiln 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 orifice delivers a gas jet and the primary air jet input from the primary air nozzle, forming a conical thin-film primary premixed jet in cooperation with the conical guide diffuser and the primary premixed gas annular nozzle. This, combined with the inclined secondary air jet generated by the secondary air nozzle, forms a multi-stage flame-stabilizing vortex, significantly improving 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.

Description

Technical Field

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

[0002] Fuel costs account for 60%-80% of the total production cost of roller kilns in the ceramic industry. Fuel price fluctuations have a significant impact on enterprise profits. Traditional burners suffer from incomplete combustion, poor flame rigidity, and easy carbon buildup under low excess air coefficient (α<1) conditions. Specifically, this manifests as insufficient flame stability, high flue gas heat loss, and insufficient anti-coking ability, leading to easy carbon buildup in the fire tubes, requiring frequent shutdowns for cleaning and affecting production continuity. Furthermore, they have poor air pressure adaptability, being sensitive to pressure fluctuations and unable to operate stably at ultra-low pressures (such as below 500Pa), limiting energy-saving potential. Summary of the Invention

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

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

[0005] A low-air-pressure, low-air-fuel-ratio roller kiln burner includes an igniter, a combustion-supporting gas delivery section, a premixed gas delivery section, and a combustion-supporting gas delivery fan. The combustion-supporting gas delivery section has an inner combustion-supporting gas delivery channel, with an outer opening forming a flame nozzle. The premixed gas delivery section is located within the combustion-supporting gas delivery channel and 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 premixing chamber at its outer opening. The gas distribution chamber has a gas delivery hole connecting to the premixing chamber. Several primary air nozzles connecting the combustion-supporting gas delivery channel and the premixing chamber are located around the periphery of the premixed gas delivery body. The conical guide diffuser is located within the premixing chamber, with its outer diameter gradually increasing outwards. 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 to the outer periphery of the premixed gas delivery body. It is provided with several secondary air nozzles that are inclined along the center line of the premixed gas delivery section. The combustion-supporting gas delivery fan and the inner peripheral wall of the combustion-supporting gas delivery section form a secondary premixed gas annular nozzle that is inclined along the center line of the premixed gas delivery section. The gas delivery hole is used to deliver the gas jet axially to the premixing chamber and premix it with the primary air jet radially input by the primary air nozzle. After premixing, the gas jet is ejected from the primary premixed gas annular nozzle to form a conical film-shaped primary premixed jet and is combusted. Then, it intersects with the secondary air jet generated by the secondary air nozzle on the combustion-supporting gas delivery fan at a certain angle to form a multi-stage flame stabilizing vortex. The tertiary air jet generated by the secondary premixed gas annular nozzle is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion.

[0006] Compared with existing technologies, the low air pressure and low air-fuel ratio roller kiln burner of the present 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 conveying section and the auxiliary gas conveying fan: the gas jet conveyed by the gas conveying hole and the primary air jet input by the primary air nozzle form a conical film-shaped primary premixed jet under the cooperation of the conical guide diffuser and the primary premixed gas annular nozzle. Combined with the inclined secondary air jet generated by the secondary air nozzle, a multi-stage flame stabilizing vortex is formed, which significantly improves flame rigidity and combustion fullness. The design of the gas distribution chamber and radial primary air nozzle enhances 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 is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion. Combined with the inclined arrangement of the secondary air nozzle, 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.

[0007] Furthermore, the combustion-supporting air supply fan is a conical disc structure, and several secondary air nozzles are arranged circumferentially on the combustion-supporting air supply fan. With this arrangement, the conical disc structure of the combustion-supporting air supply fan forms a uniformly distributed inclined secondary air jet through the circumferentially arranged secondary air nozzles. This not only enhances the radial mixing effect between 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 residence time of the combustion gas, enabling complete combustion to be maintained even under ultra-low air pressure conditions. At the same time, the centrifugal effect generated by the conical disc 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.

[0008] Furthermore, by tilting several of the secondary air nozzles along a relative radial direction, the centrifugal effect of the generated premixed airflow can effectively prevent carbon soot from depositing at the nozzles, further improving the burner's resistance to carbon buildup and its adaptability to low-pressure conditions.

[0009] Furthermore, the orientation of the secondary air nozzle is perpendicular to the inner conical surface of the combustion-supporting air distribution fan. This arrangement, with the secondary air nozzle perpendicular to the inner conical surface of the combustion-supporting air distribution fan, allows the secondary air jet to cut into the primary premixed jet at the optimal angle. While ensuring sufficient shear mixing between the primary and secondary air jets, it forms a bidirectional vortex in both the axial and radial directions. This enhances the high-temperature flue gas recirculation effect to stabilize the flame root, and the conical reflection effect of the conical disc structure extends the mixing path between the secondary air jet and the primary premixed jet, thereby achieving complete combustion under lower air-fuel ratio conditions. This vertical injection method also allows the secondary air jet to diffuse evenly along the conical surface, effectively eliminating local oxygen-rich or oxygen-deficient areas and avoiding local high-temperature coking or incomplete combustion caused by uneven mixing. This further improves the reliability and energy efficiency of the burner under extreme operating conditions.

[0010] 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.

[0011] 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.

[0012] Furthermore, the primary air nozzles are arranged in multiple rows along the axial direction in the premixing chamber. This arrangement creates a stepped air distribution structure, allowing the combustion air to be gradually mixed with the fuel gas in stages and zones. This avoids the problem of local overcooling caused by concentrated air distribution at a single point 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 burnout air through downstream nozzles, creating 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.

[0013] Furthermore, the gas distribution chamber is connected to a main gas delivery unit, and 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.

[0014] 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.

[0015] 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.

[0016] 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

[0017] Figure 1 This is a cross-sectional view of a roller kiln burner with low air pressure and low air-fuel ratio.

[0018] Figure 2 This is a cross-sectional view of the burner of a low-air-pressure, low-air-fuel-ratio roller kiln located at the inlet regulating valve.

[0019] Figure 3This is a cross-sectional view of the burner of a low-air-pressure, low-air-fuel-ratio roller kiln located in the premixed gas conveying section.

[0020] Figure 4 This is a schematic diagram of the premixed gas delivery section and the combustion-supporting gas delivery fan coil unit.

[0021] Figure 5 This is a cross-sectional view of the premixed gas delivery section located at the primary air nozzle.

[0022] Figure 6 Cross-section of the intake regulating valve Figure 1 .

[0023] Figure 7 Cross-section of the intake regulating valve Figure 2 .

[0024] 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 141, Primary air nozzle 111, 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 cavity 661, Flow regulating hole 67, Valve core cavity 621, Valve cover 68, Clearance port 69, Assembly port 611, Corrugated spring 613, Sealing ring 614, Valve position pointer 615. Detailed Implementation

[0025] The specific embodiments of the present invention are described below with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0026] See Figures 1 to 7 The low air pressure and low air-fuel ratio roller kiln burner of the present invention includes an igniter 5, a combustion gas delivery unit 2, a premixed gas delivery unit 1, and a combustion gas delivery fan 3.

[0027] 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.

[0028] The premixed gas delivery unit 1 is located within the combustion-supporting gas delivery channel 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 its inner end and a premixing chamber 14 with an opening at its outer end. The gas distribution chamber 13 has a gas delivery hole 141 communicating with the premixing chamber 14. The premixed gas delivery body 11 has several primary air nozzles 111 on its outer periphery communicating with the combustion-supporting gas delivery channel 21 and the premixing chamber 14. The conical guide diffuser 12 is located inside the premixing chamber 14 and is connected to the inner end of the premixing chamber 14 via a connecting column 121. The connecting column 121 is cylindrical and... The outer diameter is smaller than that of the conical flow guide diffuser 12, and the outer diameter of the conical flow guide diffuser 12 gradually increases along the outer direction. Multiple gas delivery holes 141 are provided around the connecting column 121. A primary premixed gas annular nozzle 15 is formed between the inner circumference of the opening of the premixing chamber 14 and the outer circumference of the bottom of the conical flow guide diffuser 12. The rear end opening of the gas distribution chamber 13 is connected to the 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.

[0029] The combustion-supporting gas conveying fan 3 is connected to the outer periphery of the premixed gas conveying body 11. It is provided with a number of secondary air nozzles 31 that are inclined along the center line of the premixed gas conveying section 1. The combustion-supporting gas conveying fan 3 and the inner peripheral wall of the combustion-supporting gas conveying section 2 form a secondary premixed gas annular nozzle 32 that is inclined along the center line of the premixed gas conveying section 1. The premixed gas conveying section 1 and the combustion-supporting gas conveying fan 3 are an integral structure.

[0030] The gas delivery hole 141 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 111. 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 combustion-supporting 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.

[0031] Compared with the prior art, the low air pressure and low air-fuel ratio roller kiln burner of the present 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 conveying section 1 and the auxiliary gas conveying fan 3: the gas conveying hole 141 conveys the gas jet and the primary air jet input by the primary air nozzle 111, forming a conical film-shaped primary premixed jet under the cooperation of the conical guide diffuser 12 and the primary premixed gas annular nozzle 15, which, 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 111 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 of the primary premixed jet and the secondary air jet during combustion, and together with the inclined secondary air nozzle 31, a pressure adaptive structure is formed, which enables the burner to maintain flame stability 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.

[0032] See Figures 1 to 5 In one embodiment, the combustion-supporting air supply fan 3 is a conical disc structure, and a plurality of secondary air nozzles 31 are arranged circumferentially on the combustion-supporting air supply fan 3. With this arrangement, the combustion-supporting air supply fan 3 of the conical disc structure 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 forms a stable high-temperature vortex zone in the combustion area. This strengthens the flame rigidity and prolongs the residence time of the combustion gas, enabling complete combustion to be maintained even under ultra-low air pressure conditions. At the same time, the centrifugal effect generated by the conical disc 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.

[0033] 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.

[0034] In one embodiment, the secondary air nozzle 31 is oriented along the axial direction of the premixed gas delivery section 1.

[0035] See Figures 1 to 5In one embodiment, the orientation of the secondary air nozzle 31 is perpendicular to the inner conical surface of the combustion-supporting air supply fan 3. This arrangement, with the secondary air nozzle 31 perpendicular to the inner conical surface of the combustion-supporting air supply fan 3, allows the secondary air jet to cut into the primary premixed jet at an optimal angle. This ensures thorough shear mixing between the primary and secondary air jets while simultaneously creating a bidirectional vortex in both the axial and radial directions. This enhances the high-temperature flue gas recirculation effect to stabilize the flame root, and the conical reflection effect of the conical combustion-supporting air supply fan 3 extends the mixing path between the secondary and primary premixed jets, thus achieving complete combustion under lower air-fuel ratio conditions. This vertical injection method also ensures uniform diffusion of the secondary air jet along the conical surface, effectively eliminating localized oxygen-rich or oxygen-deficient areas and preventing localized high-temperature coking or incomplete combustion caused by uneven mixing. This further improves the reliability and energy efficiency of the burner under extreme operating conditions.

[0036] 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.

[0037] 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.

[0038] See Figures 1 to 5In one embodiment, the primary air nozzles 111 are arranged in multiple rows along the axial direction in the premixing chamber 14. With this arrangement, the multiple rows of axially arranged primary air nozzles 111 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.

[0039] See Figure 6 and Figure 7 In one embodiment, the combustion-supporting gas delivery section 2 is equipped with an air intake regulating valve 6, which is used to regulate the air intake volume of the combustion-supporting gas delivery channel 21. With this configuration, the air intake volume can be adjusted according to process requirements by setting the air intake regulating valve 6.

[0040] See Figure 6 and Figure 7 In 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.

[0041] See Figure 6 and Figure 7In 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.

[0042] See Figure 6 and Figure 7 In 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.

[0043] 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 low-air-pressure, low-air-fuel-ratio roller kiln burner, characterized in that, include: Ignition device; 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 is located within the combustion gas delivery channel and 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 that connects to the premixing chamber. The periphery of the premixed gas delivery body is provided with several primary air nozzles that connect the combustion gas delivery channel and the premixing chamber. The conical guide diffuser is located within the premixing chamber. 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 conveying fan is connected around the outer periphery of the premixed gas conveying body and has several secondary air nozzles that are inclined along the center line of the premixed gas conveying section. The combustion-supporting gas conveying fan and the inner peripheral wall of the combustion-supporting gas conveying section form a secondary premixed gas annular nozzle that is inclined along the center line of the premixed gas conveying section. The gas delivery hole is used to transport the gas jet axially to the premixing chamber and premix it with the primary air jet radially input from the primary air nozzle. After premixing, the gas jet is ejected from the primary premixed gas annular nozzle to form a conical film-shaped primary premixed jet and is combusted. Then, it intersects with the secondary air jet generated by the secondary air nozzle on the combustion-supporting gas delivery fan at a certain angle to form a multi-stage flame-stabilizing vortex. The tertiary air jet generated by the secondary premixed gas annular nozzle is used to extend the mixing path between the primary premixed jet and the secondary air jet during combustion.

2. The low air pressure, low air-fuel ratio roller kiln burner according to claim 1, characterized in that, The combustion-supporting air conveying fan has a conical disc structure, and several secondary air nozzles are arranged circumferentially on the combustion-supporting air conveying fan.

3. The low air pressure, low air-fuel ratio roller kiln burner according to claim 2, characterized in that, The orientation of the secondary air nozzle is perpendicular to the inner conical surface of the combustion-supporting air delivery fan.

4. The low air pressure, low air-fuel ratio roller kiln 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.

5. The low air pressure, low air-fuel ratio roller kiln burner according to claim 1, 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.

6. The low air pressure, low air-fuel ratio roller kiln burner according to claim 1, characterized in that, The primary air nozzles are located in the premixing chamber and are arranged in multiple rows along the axial direction.

7. The low air pressure, low air-fuel ratio roller kiln burner according to any one of claims 1 to 6, characterized in that, 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.

8. The low air pressure, low air-fuel ratio roller kiln burner according to claim 7, 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.

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

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