Porous graded air distribution biomass gas low-nitrogen burner

Abstract

The invention relates to the technical field of combustion equipment, in particular to a porous staged air distribution biomass gas low-nitrogen combustor which comprises a fan, a combustion cylinder is fixedly arranged at the output end of the fan, a first-stage mixing part is arranged at one end in the combustion cylinder, the first-stage mixing part forms an equidistant flow dividing structure and cuts airflow, and the first-stage mixing part further forms a tightening structure; a plurality of groups of crossed flow channels are formed in the first-stage mixing part, a second-stage mixing part is arranged at one end of the first-stage mixing part, a stirring structure is arranged to tear gas blocks, a plurality of filtering structures are formed in the second-stage mixing part, a third-stage mixing part is arranged at one end of the second-stage mixing part, and a plurality of axially arranged porous structures are formed in the third-stage mixing part. The first-stage mixing part is used for cutting mixed gas at equal intervals to generate large turbulent flow, then the mixed gas flows through the tightening structure and the multiple sets of cross flow channels to generate shearing force, the stirring structure drives the filtering structure to rotate when rotating, and finally the mixed gas flows through the third-stage mixing part to increase the number of times of gas flow impact and flow division.

Description

Technical Field

[0001] This invention relates to the field of combustion equipment technology, and more specifically, to a porous, staged air distribution biomass gas low-NOx burner. Background Technology

[0002] Biomass fuel gas is a combustible gas generated from biomass through processes such as pyrolysis and gasification. It mainly includes combustible gases such as carbon monoxide, hydrogen, and methane, which provide combustion heat energy; inert gases such as carbon dioxide and nitrogen, which affect the calorific value and combustion characteristics of the fuel gas; and small amounts of impurities such as water vapor, tar, and hydrogen sulfide, which require purification treatment to avoid equipment corrosion. Low-NOx burners are combustion equipment specifically designed for biomass fuel gas. They reduce nitrogen oxide (NOx) emissions through staged combustion and flue gas recirculation technologies. They are mainly used in boilers, industrial kilns, and other scenarios to achieve efficient combustion and environmentally friendly emissions in processes such as heating, power generation, and drying, meeting the requirements of low-carbon and environmental protection.

[0003] Currently, existing burners have the following drawbacks when in use: Firstly, the burner generates airflow through a fan. The airflow carries biomass gas and flows and mixes inside the burner before being ignited by the ignition head at the burner's output end. However, existing burners mostly rely on the natural diffusion and mixing of gas and air, which results in a slow mixing speed and poor mixing effect. This leads to incomplete combustion of biomass gas when it is ignited, making it easy to produce nitrogen oxides. Secondly, biomass gas generally contains a certain amount of impurities, such as tar, ash and sawdust. Even after purification by a purification system, the fine particles of impurities in biomass gas are still difficult to remove. After entering the burner with the biomass gas, the impurities can easily clog the internal channels of the burner, which is not conducive to the normal operation of the burner. In view of this, we propose a porous staged air distribution biomass gas low-NOx burner. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a porous, staged air distribution biomass gas low-NOx burner. This solves the problems that existing solutions rely on the natural diffusion of gas and air to mix air and biomass gas, resulting in a slow mixing speed. Furthermore, biomass gas generally contains a certain amount of impurities, and even after purification by a purification system, the fine particles of these impurities are still difficult to remove.

[0005] To achieve the above objectives, a porous, staged air distribution biomass gas low-NOx burner includes a blower. A combustion chamber is fixedly installed at the output end of the blower. A proportioning device for proportioning biomass gas and air is fixedly connected to one side of the combustion chamber. An ignition head for igniting the biomass gas is fixedly installed at one end of the combustion chamber. A primary mixing section for preliminary mixing of biomass gas and air is provided at one end inside the combustion chamber. The primary mixing section forms an equidistant flow-dividing structure, cutting the airflow and breaking the laminar flow state. The primary mixing section also forms a tightening structure, with the cross-sectional area shrinking axially, accelerating the airflow to generate a jet and forming turbulence. The primary mixing section also forms multiple sets of intersecting flow channels, causing the airflow to generate shear force and forming turbulent vortices. A secondary mixing section is provided at one end of the primary mixing section. The secondary mixing section is used to further mix biomass fuel gas and air, and to filter impurities such as tar, ash, and sawdust from the mixed gas. The secondary mixing section is equipped with a stirring structure to agitate the fluid and generate turbulence, tearing apart gas clumps. The secondary mixing section also forms multiple filter structures, which rotate with the stirring structure, causing the airflow to generate spiral flow on the surface of the filter structures, increasing the probability of particle collision with the filter structures, and inducing high-frequency small-scale vortices to form multi-scale vortex coupling, promoting airflow mixing. In addition, the secondary mixing section, in conjunction with cross-flow channels, increases the relative flow velocity of the airflow and promotes the uniformity of gas mixing. A tertiary mixing section is provided at one end of the secondary mixing section. The tertiary mixing section forms multiple axially arranged porous structures with progressively smaller pore sizes, creating periodic disturbances and increasing the number of airflow impacts and splits.

[0006] The beneficial effects of this invention are: 1) In this porous staged air distribution biomass gas low-NOx burner, the air-biomass gas mixture is first cut at equal intervals by the equidistant flow splitting structure and tightening structure of the first-stage mixing section, generating large turbulence in the mixture and breaking the laminar flow state of the mixture, thus playing a preliminary mixing role. The mixture then flows through the tightening structure, which, in conjunction with multiple sets of cross-flow channels, generates shear force in the mixture. As the cross-sectional area of ​​the tightening structure shrinks along the axial direction, the velocity of the mixture increases, generating a jet and forming turbulence again, further playing a mixing role. In conjunction with the stirring and filtering structures of the second-stage mixing section, the rotation of the stirring structure drives the rotation of the filtering structure, stirring the mixture and inducing high-frequency small-scale vortices, forming multi-scale vortex coupling, effectively improving the mixing uniformity of the mixture. Finally, the mixture flows through multiple porous structures in the third-stage mixing section. The pore size of the multiple porous structures decreases sequentially, forming periodic disturbances, increasing the number of airflow impacts and splits, generating fine turbulence, and fully mixing the air and biomass gas, which is conducive to the complete combustion of biomass gas.

[0007] 2) In this porous staged air distribution biomass gas low-NOx burner, through the setting of multiple cross channels in the primary mixing section and the secondary mixing section, the mixed gas passes through the contraction structure of the primary mixing section and enters the cross channels, forming multiple sets of cross small airflows. When two airflows in each set of small airflows are ejected from the corresponding cross channels, the two airflows overlap and intersect. The airflow impacts the filter structure at a certain speed, and the filter structure retains impurities in the airflow. As the filter structure rotates with the stirring structure, due to the centrifugal force, the impurities filtered by the filter structure are not easy to leave the filter structure and return to the mixed gas, reducing the possibility of impurities clogging the tertiary mixing section, which is conducive to ensuring the normal operation of the combustion chamber.

[0008] Based on the above technical solution, the present invention can be further improved as follows: As a further improvement to this technical solution, the primary mixing section includes a conical hood, the outer wall of which is fixedly disposed at one end of the inner wall of the combustion cylinder, and the cross-sectional area of ​​the conical hood decreases axially in the direction away from the blower.

[0009] The beneficial effect of adopting the above-mentioned further scheme is that, by setting the conical mask, the mixed gas entering the conical mask flows along the axial direction of the conical mask. As the cross-sectional area of ​​the conical mask becomes smaller and smaller, the mixed gas contracts, which increases the flow velocity of the mixed gas. After the flow velocity of the mixed gas increases, the rapidly flowing gas generates a jet and forms turbulence, which further plays a role in homogenizing the mixed gas.

[0010] As a further improvement to this technical solution, the cone-shaped cover is fixedly provided with multiple inclined plates at one end near the fan, which are vertically arranged and linearly equidistantly distributed.

[0011] The beneficial effect of adopting the above-mentioned further scheme is that by using multiple equally spaced inclined plates, the mixed airflow entering the conical mask is divided, which causes the mixed airflow to generate large turbulence, thereby breaking the laminar flow state of the mixed airflow and playing a preliminary mixing role.

[0012] As a further improvement to this technical solution, a fixing block is fixedly installed at the end of the conical mask away from the fan. The fixing block has multiple sets of inclined holes that communicate with the inside of the conical mask. Each set of inclined holes has two holes and is arranged in a figure-eight shape. Each of the inclined holes is designed to be frustum-shaped, with the cross-sectional area decreasing along the axial direction.

[0013] The beneficial effect of adopting the above-mentioned further scheme is that, through the multiple sets of inclined holes arranged in a figure-eight shape, the airflow flowing through the conical mask enters the multiple sets of inclined holes, and a mixed airflow is divided into multiple fine mixed airflows. Each set of fine mixed airflows passes through the corresponding inclined hole and enters the secondary mixing section. Since the cross-sectional area of ​​the inclined hole is smaller than that of the conical mask, the flow velocity of the fine mixed airflow is further accelerated. This not only generates even smaller turbulence in the fine airflows, promoting further homogenization of the mixed gas, but also causes each set of fine mixed airflows to overlap and collide with each other in the secondary mixing section, generating shear force and forming turbulent vortices, further promoting homogenization of the mixed gas. Moreover, the airflow impacts the filter structure of the secondary mixing section at a relatively high speed, which can also promote homogenization of the mixed gas and help the filter structure filter out impurities in the mixed gas.

[0014] As a further improvement to this technical solution, the secondary mixing section includes a fixing box, the surface of which is fixedly disposed at the center of the inner wall of the combustion cylinder, one end of the fixing block is fixedly connected to one end of the fixing box, and the multiple sets of inclined holes are all in communication with the interior of the fixing box. The top of the fixed box is rotatably provided with a rotating shaft, and multiple mounting brackets are fixedly provided on the surface of the rotating shaft. The outer walls of the multiple mounting brackets are in contact with the inner wall of the fixed box.

[0015] The beneficial effect of adopting the above-mentioned further solution is that the rotating shaft drives the mounting frame to rotate inside the fixed box. The filter structure is installed on the mounting frame. The rotation of the mounting frame drives the filter structure to rotate. During the rotation, the mounting frame and the filter structure continuously impact the mixed airflow, continue to generate turbulence in the gas, and continuously tear apart gas clumps, which can promote further homogenization of the mixed gas.

[0016] As a further improvement to this technical solution, filters are fixedly installed on the inner walls of multiple mounting brackets.

[0017] The beneficial effects of adopting the above-mentioned further solution are that, through the setting of the filter screen, when the filter screen rotates with the mounting bracket and the rotating shaft, the openings on the filter screen fully contact the mixed airflow entering the fixed box and continuously impact the airflow, causing the airflow to repeatedly pass through the filter screen, separating the mixed airflow into fine airflows, and inducing high-frequency small-scale vortices, forming multi-scale vortex coupling, which can effectively promote the mixed gas to achieve a further homogenization effect. In addition, the filter screen continuously rotates in the same direction, retaining impurities in the mixed airflow on the filter screen. Due to the centrifugal force generated by the rotation of the filter screen, the impurities remain on the filter screen for a long time and are not easy to detach from the filter screen and return to the mixed gas, reducing the possibility of impurities clogging the third-stage mixing section. Moreover, the airflow ejected from the inclined hole impacts the filter screen, which can promote the further homogenization of the mixed gas.

[0018] As a further improvement to this technical solution, the secondary mixing section also includes a mounting block. The bottom of the mounting block is fixedly mounted on the top of the combustion cylinder, and a motor is fixedly mounted on the top of the mounting block. The output end of the motor passes through the mounting block and the combustion cylinder and is fixedly connected to the top of the rotating shaft.

[0019] The beneficial effect of adopting the above-mentioned further solution is that by operating the motor, the rotating shaft is driven to rotate, which in turn drives the mounting bracket and filter screen, thereby further agitating the gas in the fixed box, achieving the purpose of mixing the gas and filtering impurities in the gas.

[0020] As a further improvement to this technical solution, multiple conical blocks are fixedly arranged on one side of each of the mounting brackets, and the tips of the conical blocks face the same direction as the rotation of the motor.

[0021] The beneficial effect of adopting the above-mentioned further solution is that, by setting the conical block, the conical block continuously punctures the mixed airflow as the mounting frame rotates, causing the mixed airflow to generate micro-turbulence near the conical block, which promotes further homogenization of the mixed gas.

[0022] As a further improvement to this technical solution, the three-stage mixing section includes an air guide tube, one end of which is fixedly connected to the other end of the fixed box; The inner wall of the air duct has annularly distributed grooves.

[0023] The beneficial effect of adopting the above-mentioned further solution is that, through the setting of the gas guide pipe, the mixed gas can leave the fixed box and continue to flow along the inside of the combustion cylinder. The mixed gas flows through the gas guide pipe into the third-stage mixing section, so that the third-stage mixing section continues to perform the mixing operation on the mixed gas.

[0024] As a further improvement to this technical solution, one end of the air guide tube is fixedly connected to an installation cover, and a plurality of perforated plates are fixedly arranged inside the installation cover, wherein the aperture of the plurality of perforated plates decreases along the axial direction.

[0025] The beneficial effect of adopting the above-mentioned further scheme is that, through the setting of the mounting hood and perforated plates, the mixed airflow passes through the air guide pipe into the interior of the mounting hood and continues to move along the interior of the mounting hood, thereby passing through several perforated plates. Moreover, the aperture of the perforated plates gradually decreases along the flow direction of the mixed airflow, forming periodic disturbances to the mixed gas, increasing the number of airflow impacts and splits, generating fine turbulence, and fully mixing the air and biomass fuel gas.

[0026] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages, which will be further described in detail below with reference to the figures. Attached Figure Description

[0027] Figure 1This is a schematic diagram of the overall external first-view structure of the present invention; Figure 2 This is a schematic diagram of the overall external second-view structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the combustion chamber of the present invention; Figure 4 This is a first-view structural diagram showing the connection between the primary mixing section, the secondary mixing section and the tertiary mixing section of the present invention. Figure 5 This is a second-view structural diagram showing the connection between the primary mixing section, the secondary mixing section and the tertiary mixing section of the present invention. Figure 6 This is a schematic diagram of the flow of the mixed airflow inside the combustion chamber according to the present invention; Figure 7 For the present invention Figure 6 Enlarged view of the structure at point A in the middle; Figure 8 For the present invention Figure 6 Enlarged view of the structure at point B.

[0028] The meanings of the labels in the diagram are as follows: 1. Fan; 2. Combustion cylinder; 3. Proportioning device; 4. Ignition head; 5. Primary mixing section; 51. Conical shroud; 52. Inclined plate; 53. Fixing block; 54. Inclined hole; 6. Secondary mixing section; 61. Fixing box; 62. Rotating shaft; 63. Mounting bracket; 64. Filter screen; 65. Mounting block; 66. Motor; 67. Conical block; 7. Tertiary mixing section; 71. Air guide pipe; 72. Groove; 73. Mounting cover; 74. Perforated plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The way air and biomass gas are mixed in the combustion chamber mostly relies on the natural diffusion of gas and air, which is a slow mixing speed. Biomass gas generally contains a certain amount of impurities, and even after purification by a purification system, the fine particles of impurities in biomass gas are still difficult to remove.

[0031] Therefore, this invention provides a porous, staged air distribution biomass gas low-NOx burner. Please refer to [link / reference]. Figures 1-8The system includes a blower 1, which comprises a motor, casing, and impeller. The motor is mounted outside the casing, and the impeller is mounted inside. The motor drives the impeller to rotate. A combustion chamber 2 is fixedly installed at the output end of the blower 1. A proportioning device 3 for mixing biomass fuel gas and air is fixedly connected to one side of the combustion chamber 2. The proportioning device 3 includes a gas valve, an air valve, a proportional adjustment structure, and a pressure sensor. The proportional adjustment structure synchronously adjusts the opening of the gas valve and the air valve according to the signal. The pressure sensor monitors and provides feedback in real time to ensure that the fuel gas and air are mixed in proportion, achieving precise proportioning. An ignition head 4 for igniting biomass fuel gas is fixedly installed at one end of the combustion chamber 2. A primary mixing section 5 for preliminary mixing of biomass fuel gas and air is installed at one end inside the combustion chamber 2. The primary mixing section 5 forms an equidistant flow distribution structure, cutting the airflow and breaking the laminar flow state. The primary mixing section 5 also forms a tightening structure, with the cross-sectional area shrinking axially, accelerating the airflow to generate a jet. The primary mixing section 5 forms multiple sets of intersecting channels, generating shear force in the airflow and creating turbulent vortices. A secondary mixing section 6 is located at one end of the primary mixing section 5. The secondary mixing section 6 is used for secondary mixing of biomass fuel gas and air, and filters impurities such as tar, ash, and sawdust from the mixed gas. The secondary mixing section 6 is equipped with a stirring structure to agitate the fluid, generating turbulence and tearing apart gas clumps. The secondary mixing section 6 also forms multiple filter structures that rotate with the stirring structure, causing the airflow to spiral on the filter structure surface, increasing the probability of particle collisions with the filter structure and inducing high-frequency small-scale vortices, forming multi-scale vortex coupling, promoting airflow mixing. Furthermore, the secondary mixing section 6, in conjunction with the intersecting channels, increases the relative velocity of the airflow, promoting gas mixing uniformity. A tertiary mixing section 7 is located at one end of the secondary mixing section 6. The tertiary mixing section 7 forms multiple axially arranged porous structures with progressively decreasing pore sizes, creating periodic disturbances and increasing the number of airflow impacts and splits. Specifically: The present invention is as follows Figure 1-3 As shown, considering that the burner generates airflow through the fan 1, and the airflow carries biomass fuel gas through the combustion chamber 2 for mixing, and then it is ignited by the ignition head 4 at the output end of the combustion chamber 2, the existing combustion chamber 2 relies mainly on the natural diffusion and mixing of the fuel gas and air. This mixing speed is slow and the mixing effect is poor, resulting in incomplete combustion of the biomass fuel gas when ignited, easily producing nitrogen oxides. Therefore, if... Figure 3-5As shown, the air-biomass combustion gas mixture is first cut at equal intervals by the equidistant flow splitting and tightening structures of the first-stage mixing section 5, generating large turbulence and breaking the laminar flow state of the mixture, thus achieving initial mixing. The mixture then flows through the tightening structure, which, in conjunction with multiple sets of cross-flow channels, generates shear force. As the cross-sectional area of ​​the tightening structure shrinks along the axial direction, the velocity of the mixture increases, generating a jet and forming turbulence again, further enhancing the mixing effect. Combined with the stirring and filtering structures of the second-stage mixing section 6, the rotation of the stirring structure drives the rotation of the filtering structure, stirring the mixture and inducing high-frequency small-scale vortices, forming multi-scale vortex coupling, effectively improving the mixing uniformity of the mixture. Finally, the mixture flows through the multiple porous structures of the third-stage mixing section 7. The pore size of the multiple porous structures decreases sequentially, forming periodic disturbances, increasing the number of airflow impacts and splits, generating fine turbulence, and fully mixing the air and biomass combustion gas, which is beneficial to the complete combustion of biomass combustion gas. Furthermore, biomass gas generally contains a certain amount of impurities, such as tar, ash, and sawdust. Even after purification by a purification system, the fine particles of these impurities are still difficult to remove. These impurities, once inside the combustion chamber 2, can easily clog its internal channels, hindering its normal operation. Therefore, if... Figure 3 As shown, through the multiple cross channels of the primary mixing section 5 and the secondary mixing section 6, the mixed gas passes through the contraction structure of the primary mixing section 5 and enters the cross channels, forming multiple sets of cross-flow small streams. When two streams in each set of small streams are ejected from the corresponding cross channels, the two streams overlap and intersect. The airflow impacts the filter structure at a certain speed, and the filter structure retains impurities in the airflow. As the filter structure rotates with the stirring structure, due to the centrifugal force, the impurities filtered by the filter structure are not easily removed from the filter structure and return to the mixed gas, reducing the possibility of impurities clogging the tertiary mixing section 7, which is beneficial to ensuring the normal operation of the combustion chamber 2.

[0032] Based on the above, the specific structure will be disclosed in detail: To achieve the desired effect of air and biomass fuel gas entering the primary mixing section 5, flowing through a contraction structure to accelerate the gas flow, generate a jet, and create turbulence to further promote mixing, the specific structure of the primary mixing section 5 must be disclosed. Therefore, as... Figure 3As shown, the primary mixing section 5 includes a conical shroud 51. The outer wall of the conical shroud 51 is fixedly disposed at one end of the inner wall of the combustion cylinder 2. The cross-sectional area of ​​the conical shroud 51 decreases axially in the direction away from the blower 1. By setting the conical shroud 51, the mixed gas entering the conical shroud 51 flows along the axial direction of the conical shroud 51. As the cross-sectional area of ​​the conical shroud 51 becomes smaller and smaller, the mixed gas contracts, which increases the flow velocity of the mixed gas. After the flow velocity of the mixed gas increases, the rapidly flowing gas generates a jet and forms turbulence, which further plays a role in homogenizing the mixed gas.

[0033] To ensure that air and biomass fuel gas entering the conical shroud 51 are cut off by the equidistant flow-splitting structure in the primary mixing section 5, creating large turbulence, it is necessary to further disclose the specific structure of the primary mixing section 5. Therefore, as... Figure 3 As shown, multiple inclined plates 52 are fixedly installed at one end of the conical mask 51 near the fan 1. The multiple inclined plates 52 are equidistant flow splitting structures, and are vertically arranged and linearly equidistantly distributed. Through the multiple equidistantly distributed inclined plates 52, the mixed airflow entering the conical mask 51 is divided, so that the mixed airflow generates large turbulence, thereby breaking the laminar flow state of the mixed airflow and playing a preliminary mixing role.

[0034] In order for the already contracted mixed airflow flowing through the conical mask 51 to continue flowing into the crossflow channel of the primary mixing section 5, the diameter of the mixed airflow continues to contract, and it is ejected alternately from the crossflow channel. This, combined with the secondary mixing section 6 continuing to mix the mixed airflow and filter impurities, requires further disclosure of the specific structure of the primary mixing section 5. Therefore, as... Figure 6 As shown, a fixing block 53 is fixedly installed at the end of the conical mask 51 away from the fan 1. The fixing block 53 has multiple sets of inclined holes 54 that communicate with the inside of the conical mask 51. Each set of inclined holes 54 has two holes and is arranged in a figure-eight shape. Each inclined hole 54 is designed to be a frustum shape, with the cross-sectional area decreasing along the axial direction; Multiple sets of inclined holes 54 arranged in a figure-eight shape allow the airflow passing through the conical mask 51 to enter the multiple sets of inclined holes 54. A single mixed airflow is divided into multiple fine mixed airflows. Each set of fine mixed airflows passes through the corresponding inclined hole 54 and enters the secondary mixing section 6. Since the cross-sectional area of ​​the inclined hole 54 is smaller than that of the conical mask 51, the flow velocity of the fine mixed airflows is further increased. This not only generates even smaller turbulence in the fine airflows, promoting further homogenization of the mixed gas, but also causes each set of fine mixed airflows to overlap and collide with each other in the secondary mixing section 6. This causes the airflows to generate shear force, forming turbulent vortices, which further promotes homogenization of the mixed gas. Moreover, the airflow impacts the filter structure of the secondary mixing section 6 at a relatively high speed, which also promotes homogenization of the mixed gas and helps the filter structure filter out impurities in the mixed gas.

[0035] Considering that the stirring structure in the secondary mixing section 6 is needed to drive the filtration structure to rotate, thereby generating turbulence in the mixed gas flow and tearing apart gas clumps to promote further homogenization, the specific structure of the secondary mixing section 6 needs to be disclosed. Therefore, as... Figure 4-5 As shown, the secondary mixing section 6 includes a fixing box 61, the surface of which is fixedly disposed at the center of the inner wall of the combustion cylinder 2, one end of the fixing block 53 is fixedly connected to one end of the fixing box 61, and multiple sets of inclined holes 54 are all connected to the interior of the fixing box 61. A rotating shaft 62 is rotatably mounted on the top of the fixed box 61. Multiple mounting brackets 63 are fixedly mounted on the surface of the rotating shaft 62. The outer walls of the mounting brackets 63 are in contact with the inner wall of the fixed box 61. The rotating shaft 62 drives the mounting brackets 63 to rotate inside the fixed box 61. The filter structure is mounted on the mounting brackets 63. The rotation of the mounting brackets 63 drives the filter structure to rotate. During the rotation, the mounting brackets 63 and the filter structure continuously impact the mixed airflow, continue to generate turbulence in the gas, and continuously tear apart gas clumps, which can promote further mixing of the mixed gas.

[0036] To further homogenize the mixed gas and filter impurities in it by ensuring the filter structure rotates with the shaft 62 and mounting bracket 63, the specific structure of the secondary mixing unit 6 needs to be disclosed further. Therefore, as... Figure 4-5 As shown, multiple mounting brackets 63 are fixedly equipped with filter screens 64 on their inner walls. With the filter screens 64 rotating with the mounting brackets 63 and the rotating shaft 62, the openings on the filter screens 64 fully contact the mixed airflow entering the fixed box 61, continuously impacting the airflow. This causes the airflow to repeatedly pass through the filter screens 64, separating the mixed airflow into fine airflows and inducing high-frequency small-scale vortices, forming multi-scale vortex coupling. This effectively promotes further homogenization of the mixed gas. Furthermore, the continuous rotation of the filter screens 64 in the same direction traps impurities in the mixed airflow on the filter screens 64. Due to the centrifugal force generated by the rotation of the filter screens 64, impurities remain on the filter screens 64 for a long time, making it difficult for them to detach and return to the mixed gas, reducing the possibility of impurities clogging the third-stage mixing section 7. Moreover, the airflow ejected from the inclined holes 54 impacts the filter screens 64, further promoting homogenization of the mixed gas.

[0037] To enable the rotating shaft 62 to drive the mounting bracket 63 and filter screen 64 to rotate, thereby promoting further mixing of the gas mixture and filtering impurities in the gas mixture, the specific structure of the secondary mixing unit 6 needs to be further disclosed. Therefore, as... Figure 4-5As shown, the secondary mixing section 6 also includes a mounting block 65. The bottom of the mounting block 65 is fixedly mounted on the top of the combustion cylinder 2, and a motor 66 is fixedly mounted on the top of the mounting block 65. The output end of the motor 66 passes through the mounting block 65 and the combustion cylinder 2 and is fixedly connected to the top of the rotating shaft 62. When the motor 66 is running, it drives the rotating shaft 62 to rotate, which in turn drives the mounting frame 63 and the filter screen 64, thereby further agitating the gas in the fixed box 61 to achieve the purpose of mixing the gas and filtering impurities in the gas.

[0038] To further disperse the mixed gas in the fixing box 61 by rotating the mounting bracket 63 with the rotating shaft 62, the specific structure of the secondary mixing unit 6 needs to be disclosed. Therefore, as... Figure 4-5 As shown, multiple conical blocks 67 are fixedly mounted on one side of each mounting bracket 63, with the tips of the conical blocks 67 pointing in the same direction as the rotation of the motor 66. Through the arrangement of the conical blocks 67, as the mounting bracket 63 rotates, the conical blocks 67 continuously puncture the mixed airflow, such as... Figure 7 As shown, this generates minute turbulence in the mixed gas flow near the conical block 67, promoting further homogenization of the mixed gas.

[0039] To ensure that the mixed airflow, stirred by the rotation of the mounting bracket 63 and the filter screen 64, enters the third-stage mixing section 7 and generates even finer turbulence, the specific structure of the third-stage mixing section 7 must be disclosed. Therefore, as... Figure 3 As shown, the three-stage mixing section 7 includes an air guide tube 71, one end of which is fixedly connected to the other end of the fixed box 61. The inner wall of the air guide tube 71 is provided with annularly distributed grooves 72. The grooves 72 can help cut the mixed gas flowing through the air guide tube 71, generate turbulence, and promote the mixing effect. By setting the gas guide pipe 71, the mixed gas can leave the fixed box 61 and continue to flow along the inside of the combustion cylinder 2. The mixed gas flows through the gas guide pipe 71 and enters the three-stage mixing section 7, so that the three-stage mixing section 7 continues to mix the mixed gas.

[0040] To further disclose the specific structure of the third-stage mixing section 7, in order to make the mixed gas flowing through the air guide pipe 71 into the third-stage mixing section 7 be cut into finer particles and generate less turbulence, the specific structure of the third-stage mixing section 7 needs to be disclosed. Therefore, as... Figure 3 As shown, one end of the air guide pipe 71 is fixedly connected to a mounting cover 73. Several perforated plates 74 are fixedly arranged inside the mounting cover 73, and the aperture of the perforated plates 74 decreases axially. Through the mounting cover 73 and the perforated plates 74, the mixed airflow passes through the air guide pipe 71 and enters the interior of the mounting cover 73, continuing to move along the interior of the mounting cover 73, as shown. Figure 6 and Figure 8As shown, the gas passes through several perforated plates 74, and the aperture of the perforated plates 74 gradually decreases along the flow direction of the mixed gas flow, forming periodic disturbances to the mixed gas, increasing the number of airflow impacts and splits, generating fine turbulence, and fully mixing the air and biomass fuel gas.

[0041] In summary, the overall working principle of this invention is as follows: When the burner is needed, the output end of the burner's combustion cylinder 2 is installed at the input end of a boiler or industrial kiln. The fuel gas and air are mixed in a specific ratio using the proportioning device 3. The blower 1 is started to generate airflow, drawing the mixture of biomass fuel gas and air into the combustion cylinder 2. The mixed gas flows along the inside of the combustion cylinder 2. After being divided by multiple equally spaced inclined plates 52, the mixed gas enters the conical shroud 51. The mixed gas entering the conical shroud 51 flows axially along the axial direction of the shroud 51. As the cross-sectional area of ​​the conical shroud 51 decreases, the mixed gas contracts and enters the even smaller inclined holes 54, continuing to flow along the inclined holes 54. The mixed gas then flows within the fixed box 61. The gas is sprayed out in a cross pattern. The motor 66 is started to rotate, which drives the rotating shaft 62, mounting bracket 63 and filter screen 64 to rotate, agitating the mixed gas and filtering impurities in the mixed gas. The mixed gas continues to flow, leaving the fixed box 61, flowing through the gas guide pipe 71 into the mounting cover 73, and continuing to move along the inside of the mounting cover 73, passing through several perforated plates 74. Moreover, the aperture of the perforated plates 74 gradually decreases along the flow direction of the mixed gas flow, forming periodic disturbances to the mixed gas. The mixed gas continues to flow out of the mounting cover 73 and reaches the output end of the combustion tube 2. The ignition head 4 is started to ignite the mixed gas, achieving the purpose of efficient combustion of gas and environmentally friendly emissions in processes such as heating, power generation and drying.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A porous, staged, air-distribution biomass gas low-NOx burner, comprising a blower (1), a combustion cylinder (2) fixedly disposed at the output end of the blower (1), a proportioning device (3) for proportioning biomass gas and air fixedly connected to one side of the combustion cylinder (2), and an ignition head (4) fixedly disposed at one end of the combustion cylinder (2), characterized in that: The combustion chamber (2) has a primary mixing section (5) at one end for initial mixing of the mixed gas. The primary mixing section (5) forms an equidistant flow splitting structure to cut the airflow. The primary mixing section (5) also forms a tightening structure with axial shrinkage of cross-sectional area. The primary mixing section (5) also forms multiple sets of cross channels to generate shear force. The primary mixing section (5) has a secondary mixing section (6) at one end. The secondary mixing section (6) is used for secondary mixing of the mixed gas and filtering impurities. The secondary mixing section (6) has a stirring structure to tear apart clumps. The secondary mixing section (6) also forms multiple filtering structures to increase the probability of collision between particles and filtering structures. In conjunction with the cross channels, it increases the airflow velocity. The secondary mixing section (6) has a tertiary mixing section (7) at one end. The tertiary mixing section (7) forms multiple porous structures with successively decreasing pore sizes.

2. The porous, staged air distribution biomass gas low-NOx burner according to claim 1, characterized in that: The primary mixing section (5) includes a conical mask (51), the outer wall of which is fixedly disposed at one end of the inner wall of the combustion cylinder (2), and the cross-sectional area of ​​the conical mask (51) decreases axially in the direction away from the fan (1).

3. The porous, staged air distribution biomass gas low-NOx burner according to claim 2, characterized in that: The conical mask (51) has multiple inclined plates (52) fixedly installed at one end near the fan (1), and they are vertically arranged and linearly equidistantly distributed.

4. The porous, staged air distribution biomass gas low-NOx burner according to claim 3, characterized in that: A fixing block (53) is fixedly installed at one end of the cone mask (51) away from the fan (1). The fixing block (53) has multiple sets of inclined holes (54) that communicate with the inside of the cone mask (51). Each set of inclined holes (54) consists of two holes and is arranged in a figure-eight shape. Each of the inclined holes (54) is configured to be frustum-shaped with a cross-sectional area that decreases along the axial direction.

5. The porous, staged air distribution biomass gas low-NOx burner according to claim 4, characterized in that: The secondary mixing section (6) includes a fixed box (61), the surface of which is fixedly disposed at the center of the inner wall of the combustion cylinder (2), one end of the fixed block (53) is fixedly connected to one end of the fixed box (61), and multiple sets of inclined holes (54) are all connected to the interior of the fixed box (61). The top of the fixed box (61) is rotatably provided with a rotating shaft (62), and multiple mounting brackets (63) are fixedly provided on the surface of the rotating shaft (62). The outer walls of the multiple mounting brackets (63) are in contact with the inner wall of the fixed box (61).

6. The porous, staged air distribution biomass gas low-NOx burner according to claim 5, characterized in that: Each of the mounting brackets (63) has a filter screen (64) fixedly installed on its inner wall.

7. The porous, staged air distribution biomass gas low-NOx burner according to claim 6, characterized in that: The secondary mixing section (6) also includes a mounting block (65), the bottom of which is fixedly mounted on the top of the combustion cylinder (2), and a motor (66) is fixedly mounted on the top of the mounting block (65). The output end of the motor (66) passes through the mounting block (65) and the combustion cylinder (2) and is fixedly connected to the top of the rotating shaft (62).

8. The porous, staged air distribution biomass gas low-NOx burner according to claim 7, characterized in that: Multiple conical blocks (67) are fixedly provided on one side of each of the multiple mounting brackets (63), and the tip of the conical block (67) is oriented in the same direction as the rotation of the motor (66).

9. The porous, staged air distribution biomass gas low-NOx burner according to claim 8, characterized in that: The three-stage mixing section (7) includes an air guide tube (71), one end of which is fixedly connected to the other end of the fixed box (61); The inner wall of the air guide tube (71) is provided with annularly distributed grooves (72).

10. The porous, staged air distribution biomass gas low-NOx burner according to claim 9, characterized in that: One end of the air guide tube (71) is fixedly connected to the mounting cover (73), and a plurality of perforated plates (74) are fixedly arranged inside the mounting cover (73), and the aperture of the plurality of perforated plates (74) decreases along the axial direction.

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