Tar purification system of downdraft biomass gasifier

Abstract

The present invention relates to the technical field of biomass gasifiers, specifically to a tar purification system for a downdraft biomass gasifier, comprising a separator, on which a plurality of scrapers distributed in a central symmetrical manner are arranged, and a first guide groove corresponding to the scrapers is opened on the inner wall of the separation chamber of the separator. The tar purification system for the downdraft biomass gasifier provided by the invention comprises a scraper moving along the first guide groove located at the cylindrical part of the separation chamber, a connecting bar pushing the tar on the cylindrical part to move downward, and then the scraper moving along the first guide groove located at the conical part of the separation chamber, the conical part pushes the connecting bar, the connecting bar deforms and pushes a plurality of scrapers closer, the scraper can block the tar, and prevent the tar from being excessive and continuing to stay on the inner wall of the separation chamber beyond the connecting bar, and after the inner wall of the separation chamber is cleaned, the static electricity can better release the attraction force, and the tar and other particulate matter in the airflow is adsorbed on the inner wall of the separator, so as to ensure the cleanliness of the straw gas.

Description

Technical Field

[0001] The invention relates to the technical field of biomass gasifiers, and in particular to a tar purification system of a downdraft biomass gasifier. Background Art

[0002] The biomass gasifier is a device used to produce straw gas. It mainly uses high temperature to oxidize the biomass first and then reduce it. The hot gas generated in the oxidation zone and the reduction zone is then cracked. Finally, the cracked hot gas passes through the drying zone to generate straw gas. The straw gas is then cooled and impurities are removed before it can be used as fuel gas.

[0003] According to the publication (announcement) number CN114561231A, the publication (announcement) date is 2022.05.31, and a downdraft biomass gasifier is disclosed, including a furnace body, a gasification chamber arranged in the furnace body, and a chamber arranged outside the gasification chamber, wherein a feed port is provided at the top of the gasification chamber, and a grate is provided at the bottom. The device can use the high temperature of the gas to heat up and maintain the upper half of the gasification chamber through the design of the heat-insulating chamber, which greatly promotes the pyrolysis efficiency of the pyrolysis zone in the gasification chamber and improves the gas yield; at the same time, the gasification chamber can also be used to pre-dry the preheating chamber, reduce the requirements for the moisture content of the biomass, and save drying energy.

[0004] In the prior art including the above-mentioned patent, oxygen needs to be introduced into the biomass gasifier during the process of producing straw gas, but part of the straw gas will react with the oxygen in the biomass gasifier to generate tar vapor, which will combine with the particulate matter in the straw gas. The combination of tar vapor and particulate matter is easy to adhere to the inner wall of the straw gas flow channel, reducing the efficiency of the straw gas passing through. Therefore, it is necessary to remove the tar vapor in the straw gas in time. At present, the best way to remove tar from straw gas is the electrostatic cyclone detarring method, which applies static electricity to the inner wall of the cyclone dust collector, and uses the inertial force of the airflow in the cyclone dust collector and the electrostatic adsorption of light and small objects to adsorb the combination of tar vapor and particulate matter in the straw gas. In the process of the gas flowing along the inner wall of the cyclone dust collector, the static electricity on the inner wall of the cyclone dust collector adsorbs the combination of tar vapor and particulate matter on the inner wall of the cyclone dust collector, and the tar vapor gathers into tar droplets, but the viscosity of tar is high and the fluidity is very poor. The tar adheres to the inner wall of the cyclone dust collector, reducing the smoothness of the inner wall of the cyclone dust collector, which is not conducive to the flow of airflow along the inner wall of the cyclone dust collector. In addition, the tar adheres to the inner wall of the cyclone dust collector, which increases the distance between the airflow and the static electricity, reducing the effect of electrostatic traction on the tar. Summary of the invention

[0005] The object of the present invention is to provide a tar purification system for a downdraft biomass gasifier, aiming to solve the problem that tar adheres to the inner wall of a separator, affecting the electrostatic adsorption of subsequent tar on the inner wall of the separator.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a tar purification system for a downdraft biomass gasifier, including a separator, on which a plurality of scrapers distributed in a centrally symmetrical manner are arranged, and a first guide groove corresponding to the scrapers is opened on the inner wall of the separation chamber of the separator, and two relatively distributed scrapers form a group, and a plurality of groups of scrapers alternately move back and forth along the first guide groove, and the scraper includes a soft and elastic connecting strip slidably mounted on the inner wall of the separator, and a plurality of scrapers distributed in a linear array are arranged on the connecting strip, and when the scraper moves along the cylindrical portion of the separation chamber to the conical portion of the separation chamber, the conical portion pushes the connecting strip, and the connecting strip is deformed and the plurality of scrapers thereon are brought closer.

[0007] Preferably, a hollow cavity is provided inside the separator, and a pulling block corresponding to the scraper is movably provided inside the hollow cavity, and the pulling block moves vertically upward inside the cavity to move the scraper.

[0008] Preferably, a sliding ring is slidably provided inside the hollow cavity, and a movable ring is rotatably provided on the sliding ring, and the movable ring moves to make two pulling blocks corresponding to a pair of scrapers move synchronously.

[0009] Preferably, the movable ring is provided with a pair of paddles for moving the pull block, and the paddles include the following two states:

[0010] In the first state, the movable ring and the paddles move upward, and the two paddles push one pair of the pull blocks upward;

[0011] In the second state, the movable ring and the paddles move downward, and the movable ring rotates relative to the sliding ring so that the two paddles face the next pair of pull blocks.

[0012] Preferably, a first tenon block is provided on the movable ring, and a second guide groove for guiding the first tenon block is provided on the side wall of the hollow cavity, and the second guide groove includes vertical portions distributed in a circular array and an inclined portion for connecting two adjacent vertical portions.

[0013] Preferably, the paddle is an elastic arc-shaped piece, and the opening of the arc-shaped piece faces upward.

[0014] Preferably, a driving rod for driving the sliding ring to move is rotatably provided inside the separator, and an impeller for driving the driving rod to rotate is rotatably provided inside the air outlet pipe of the separator.

[0015] Preferably, a plurality of sealing plates for sealing the first guide groove are symmetrically and movably provided inside the first guide groove.

[0016] Preferably, the scraper is provided with a second tenon block extending into the first guide groove, and the second tenon block is provided with a push block for forcing the sealing plate to rotate toward the inside of the first guide groove.

[0017] Preferably, the second tenon block is provided with a cavity for storing cleaning liquid, the scraper blade is provided with a drain port for the cleaning liquid to flow out, and a plurality of scrapers are brought together to allow the cleaning liquid in the second tenon block to be discharged from the drain port.

[0018] In the above technical scheme, a tar purification system of a downdraft biomass gasifier provided by the present invention has the following beneficial effects: when performing tar purification work, static electricity is first introduced into the inner wall of the separator, and then the newly generated straw gas is introduced into the separator, and the gas flows along the inner wall of the separator. The scraper arranged obliquely is roughly in the same direction as the airflow, and will not hinder the airflow from flowing along the inner wall of the separator. The tar in the airflow is adsorbed by the static electricity on the inner wall of the separator, and the tar adheres to the inner wall of the separator. At this time, a group of scrapers can be driven to move, and the scraper moves along the part of the first guide groove located in the cylindrical part of the separation chamber, and the connecting bar pushes the tar on the cylindrical part to move downward, and then the scraper moves along the part of the first guide groove located in the conical part of the separation chamber, and the conical part pushes the connecting bar, and the connecting bar is deformed and pushes multiple scrapers together, and the scraper can block the tar to prevent excessive tar from crossing the connecting bar and continuing to stay on the inner wall of the separation chamber. After the inner wall of the separation chamber is cleaned, the static electricity can better release the attraction, and adsorb the tar and other particulate matter in the airflow on the inner wall of the separator to ensure the cleanliness of the straw gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 A schematic diagram of the overall structure provided for an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the internal structure of a separator provided in an embodiment of the present invention;

[0022] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 A schematic diagram of the internal structure of an air outlet pipe provided in an embodiment of the present invention;

[0024] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0025] Figure 6 A schematic diagram of the expansion structure of the separation chamber provided in an embodiment of the present invention;

[0026] Figure 7 A schematic structural diagram of a first guide groove provided in an embodiment of the present invention;

[0027] Figure 8 A schematic diagram of the structure of a second tenon block provided in an embodiment of the present invention;

[0028] Fig. 9 A schematic diagram of the internal structure of a scraper provided by an embodiment of the present invention;

[0029] Fig.10 A schematic diagram of the structure of the scrapers on the scraper provided by the embodiment of the present invention being brought together;

[0030] Fig.11 A schematic diagram of the expanded structure of the hollow cavity provided in an embodiment of the present invention;

[0031] Fig.12 A schematic structural diagram of a paddle provided in an embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 1. separator; 11. upper part; 111. separation chamber; 112. hollow chamber; 1121. second guide groove; 1122. vertical part; 1123. inclined part; 1124. movable sheet; 113. air outlet pipe; 114. impeller; 115. driving rod; 116. sliding ring; 1161. slider; 117. movable ring; 118. first tenon; 119. paddle; 12. scraper; 121. connecting strip; 122. scraper; 123. second tenon; 124. first guide groove; 125. sealing plate; 126. push block; 127. trigger block; 128. sealing sheet; 129. drain port; 131. pull block; 132. pull rope; 14. lower part. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] like Figure 1-12As shown, a tar purification system of a downdraft biomass gasifier includes a separator 1, on which a plurality of scrapers 12 distributed in a centrally symmetrical manner are arranged, and an inner wall of a separation chamber 111 of the separator 1 is provided with a first guide groove 124 corresponding to the scrapers 12 one by one, and two scrapers 12 distributed relatively to each other form a group, and a plurality of groups of scrapers 12 alternately reciprocate along the first guide groove 124, and the scraper 12 includes a soft and elastic connecting strip 121 slidably mounted on the inner wall of the separator 1, and a plurality of scrapers 122 distributed in a linear array are arranged on the connecting strip 121, and when the scraper 12 moves along the cylindrical portion of the separation chamber 111 to the conical portion of the separation chamber 111, the conical portion pushes the connecting strip 121, and the connecting strip 121 is deformed and the plurality of scrapers 122 thereon are brought closer.

[0036] Specifically, the separator 1 in the above embodiment is specifically a cyclone separator, and the scraper 12 is obliquely arranged on the inner wall of the separator 1, and the inclination angle of the scraper 12 is roughly the same as the gas flow direction in the separator 1. The separator 1 includes an upper part 11 and a lower part 14. The upper part 11 is used to separate impurities in the gas, and the lower part 14 is used to collect impurities pushed down by the scraper 12. An air inlet pipe tangent to the side wall of the cylindrical part of the separation chamber 111 is arranged on the upper part 11, and an air outlet pipe 113 is arranged at the center of the upper part 11, and the bottom of the air outlet pipe 113 is located below the air inlet pipe.

[0037] Furthermore, when the tar purification work is carried out, static electricity is first introduced into the inner wall of the separator 1, and then the newly generated straw gas is introduced into the separator 1 through the air inlet pipe. The gas flows along the inner wall of the separator 1. The inclined scraper 12 is roughly the same as the air flow direction, and will not hinder the air flow along the inner wall of the separator 1. The tar in the air flow is adsorbed by the static electricity on the inner wall of the separator 1, and the tar adheres to the inner wall of the separator 1. After the gas flows along the inner wall of the separator 1 for a distance, it is gradually separated from the inner wall of the separator 1, and the gas is discharged from the outlet pipe 113. The bottom of the outlet pipe 113 is located below the air inlet pipe, which can prevent the gas entering from the air inlet pipe from being discharged from the outlet pipe 113 without separation, and then a The scraper group 12 moves, and the scraper 12 moves along the first guide groove 124 located at the cylindrical part of the separation chamber 111. The connecting strip 121 pushes the tar on the cylindrical part to move downward, and then the scraper 12 moves along the first guide groove 124 located at the conical part of the separation chamber 111. The conical part pushes the connecting strip 121, and the connecting strip 121 deforms and pushes multiple scrapers 122 together. The scraper 122 can block the tar to prevent excessive tar from crossing the connecting strip 121 and continuing to stay on the inner wall of the separation chamber 111. After the inner wall of the separation chamber 111 is cleaned, static electricity can better release the attraction, and adsorb the tar and other particulate matter in the airflow on the inner wall of the separator 1 to ensure the cleanliness of the straw gas.

[0038] In the above technical scheme, when the tar purification work is carried out, static electricity is first introduced into the inner wall of the separator 1, and then the newly generated straw gas is introduced into the separator 1. The gas flows along the inner wall of the separator 1. The scraper 12 arranged obliquely is roughly in the same direction as the airflow, and will not hinder the airflow from flowing along the inner wall of the separator 1. The tar in the airflow is adsorbed by the static electricity on the inner wall of the separator 1, and the tar adheres to the inner wall of the separator 1. At this time, a group of scrapers 12 can be driven to move. The scraper 12 moves along the first guide groove 124 located at the cylindrical part of the separation chamber 111. The connecting strip 121 pushes the tar on the cylindrical part to move downward, and then the scraper 12 moves along the first guide groove 124. The part located at the conical part of the separation chamber 111 moves, and the conical part pushes the connecting strip 121. The connecting strip 121 is deformed and pushes multiple scrapers 122 together. The scrapers 122 can block tar to prevent excessive tar from crossing the connecting strip 121 and continuing to stay on the inner wall of the separation chamber 111, and only allow a pair of scrapers 12 to move synchronously, which can clean the inner wall of the separation chamber 111 while avoiding interference between multiple scrapers 12 in the area with a smaller diameter of the conical part of the separation chamber 111. After the inner wall of the separation chamber 111 is cleaned, static electricity can better release the attraction, and adsorb tar and other particulate matter in the airflow on the inner wall of the separator 1, thereby ensuring the cleanliness of the straw gas.

[0039] As a further embodiment of the present invention, a hollow cavity 112 is opened inside the separator 1, and a pulling block 131 corresponding to the scraper 12 is movably arranged inside the hollow cavity 112. The pulling block 131 moves vertically upward inside the hollow cavity 112 to move the scraper 12.

[0040] Specifically, a pull rope 132 is provided between the pull block 131 and the scraper 12 , and a spring located inside the first guide groove 124 is provided between the scraper 12 and the separator 1 .

[0041] Furthermore, during the upward movement of the pulling block 131 , the pulling block 131 drives the scraper 12 to move downward along the first guide groove 124 through the pulling rope 132 , scraping off the tar attached to the inner wall of the separator 1 , and at the same time the spring between the scraper 12 and the separator 1 is stretched.

[0042] As another embodiment further provided by the present invention, a sliding ring 116 is slidably provided inside the hollow cavity 112 , and a movable ring 117 is rotatably provided on the sliding ring 116 . The movable ring 117 moves to make the two pulling blocks 131 corresponding to the pair of scrapers 12 move synchronously.

[0043] Specifically, sliding blocks 1161 are symmetrically arranged on the sliding ring 116 , and sliding grooves adapted to the sliding blocks 1161 are opened on the side walls of the hollow cavity 112 .

[0044] Furthermore, when the sliding ring 116 moves in the vertical direction, the sliding ring 116 drives any pair of pulling blocks 131 to move through the movable ring 117, and then drives a pair of scrapers 12 to move, so as to scrape off the tar on the side wall of the separation chamber 111. After the pair of scrapers 12 move, the movable ring 117 rotates relative to the sliding ring 116, and the movable ring 117 can move with the next pair of scrapers 12.

[0045] As another embodiment further provided by the present invention, a pair of paddles 119 for moving the pull block 131 are provided on the movable ring 117, and the paddles 119 include the following two states:

[0046] In the first state, the movable ring 117 and the paddle 119 move upward, and the two paddles 119 push one pair of pull blocks 131 to move upward;

[0047] In the second state, the movable ring 117 and the paddles 119 move downward, and the movable ring 117 rotates relative to the sliding ring 116 so that the two paddles 119 face the next pair of pull blocks 131 .

[0048] Specifically, the pull block 131 in the above embodiment is specifically an inverted "L" shape.

[0049] Furthermore, in the process of the sliding ring 116 moving upward with the movable ring 117, the paddle 119 on the movable ring 117 pushes the horizontal part of the L-shaped pull block 131, and the paddle 119 pushes the pull block 131 to move upward, thereby driving the corresponding scraper 12 to move; in the process of the sliding ring 116 moving downward with the movable ring 117, the movable ring 117 rotates relative to the sliding ring 116, and the paddle 119 on the movable ring 117 separates from the pull block 131 and gradually moves to below the horizontal part of the next pair of L-shaped pull blocks 131, so that the movable ring 117 drives the scrapers 12 corresponding to the next pair of pull blocks 131 to move through the paddle 119.

[0050] As another embodiment further provided by the present invention, a first tenon block 118 is arranged on the movable ring 117, and a second guide groove 1121 for guiding the first tenon block 118 is opened on the side wall of the hollow cavity 112, and the second guide groove 1121 includes vertical portions 1122 distributed in a circular array and an inclined portion 1123 for connecting two adjacent vertical portions 1122.

[0051] Specifically, a movable piece 1124 is hinged at the connection between the higher end of the inclined portion 1123 and the vertical portion 1122, a torsion spring is arranged between the movable piece 1124 and the side wall of the hollow cavity 112, the first tenon block 118 is specifically cylindrical, and the number of the first tenon blocks 118 is the same as the number of the scraper 12.

[0052] Furthermore, in the process of the sliding ring 116 moving upward with the movable ring 117, the first tenon block 118 on the movable ring 117 moves along the vertical portion 1122 of the second guide groove 1121 and gradually pushes the movable sheet 1124, so that the movable sheet 1124 rotates and makes room for the first tenon block 118 to move. The first tenon block 118 continues to move upward and separates from the movable sheet 1124. The movable sheet 1124 rotates under the action of the torsion spring and returns to the vertical portion 1122 and blocks the vertical portion 1122. After the first tenon block 118 moves to the highest point, it gradually moves downward. The first tenon block 118 Gradually contact with the movable sheet 1124, the movable sheet 1124 guides the first tenon block 118 to enter the inclined portion 1123, the first tenon block 118 moves along the inclined portion 1123, gradually enters the next vertical portion 1122, the movable ring 117 rotates relative to the sliding ring 116, the paddle 119 on the movable ring 117 faces the next group of pull blocks 131, so that the paddle 119 drives the next group of pull blocks 131 to move, the number of first tenons 118 is greater than the number of slide grooves, which can ensure that there is always a first tenon block 118 located in the second guide groove 1121, ensuring that the first tenon block 118 can move along the second guide groove 1121.

[0053] As another embodiment further provided by the present invention, the paddle 119 is specifically an elastic arc-shaped piece, and the opening of the arc-shaped piece faces upward.

[0054] Specifically, when the paddle 119 approaches the pulling block 131 from above the pulling block 131, the horizontal portion of the pulling block 131 will first abut against the bottom center of the paddle 119, causing the paddle 119 to deform and gradually staggered from the horizontal portion of the pulling block 131. After the paddle 119 is separated from the pulling block 131, the paddle 119 returns to its original shape under the action of its own elasticity and is located below the horizontal portion of the pulling block 131. In the process of the paddle 119 moving upward, the arc-shaped paddle 119 has a good ability to resist the force from above and can move upward with the pulling block 131.

[0055] As another embodiment further provided by the present invention, a driving rod 115 is rotatably provided inside the separator 1 for driving the sliding ring 116 to move, and an impeller 114 is rotatably provided inside the air outlet pipe 113 of the separator 1 for driving the driving rod 115 to rotate.

[0056] Specifically, the driving rod 115 is a reciprocating screw rod, a through hole adapted to the driving rod 115 is provided on the slider 1161 on the sliding ring 116 , and a synchronous belt is provided between the impeller 114 and the driving rod 115 .

[0057] Furthermore, when the airflow flows along the outlet pipe 113, the airflow drives the impeller 114 in the outlet pipe 113 to rotate, and the impeller 114 drives the driving rod 115 to rotate through the synchronous belt, and the driving rod 115 drives the sliding ring 116 to move back and forth along the sliding groove inside the hollow cavity 112 through the slider 1161.

[0058] As another embodiment further provided by the present invention, a plurality of sealing plates 125 for sealing the first guide groove 124 are symmetrically and movably provided inside the first guide groove 124 .

[0059] Specifically, a plurality of sealing plates 125 are disposed on the side walls on opposite sides of the same first guide groove 124 , and a torsion spring is disposed between the sealing plates 125 and the first guide groove 124 .

[0060] Furthermore, the sealing plate 125 can seal the first guide groove 124 , so that the gas can flow along the side wall of the separation chamber 111 , thereby reducing the influence of the first guide groove 124 on the flow of the gas.

[0061] As another embodiment further provided by the present invention, the scraper 12 is provided with a second tenon block 123 extending into the first guide groove 124 , and the second tenon block 123 is provided with a push block 126 for pressing the sealing plate 125 to rotate into the first guide groove 124 .

[0062] Specifically, the middle part of the connecting strip 121 of the scraper 12 is fixedly mounted on the second tenon block 123, a spring located inside the first guide groove 124 is arranged between the second tenon block 123 and the separator 1, a pull rope 132 is arranged between the second tenon block 123 and the pull block 131, and a slope is arranged on the second tenon block 123 to facilitate the movement of the cylindrical part of the separation chamber 111 to the conical part.

[0063] Furthermore, in the process of the second tenon 123 moving with the scraper 12, the pusher on the second tenon 123 pushes the sealing plate 125 to rotate toward the inside of the first guide groove 124, making room for the second tenon 123 to move, so that the second tenon 123 can move with the scraper 12. After the second tenon 123 passes, the sealing plate 125 seals the first guide groove 124 again under the action of the torsion spring, thereby reducing the influence of the first guide groove 124 on the airflow.

[0064] As another embodiment further provided by the present invention, a cavity for storing cleaning liquid is provided on the second tenon block 123, a drain port 129 for the cleaning liquid to flow out is provided on the scraper blade 122, and a plurality of scrapers 122 are brought together to allow the cleaning liquid in the second tenon block 123 to be discharged from the drain port 129.

[0065] Specifically, the scraper 122 is provided with a sealing piece 128 for sealing the drain port 129, the sealing piece 128 is provided with a trigger block 127 extending to the outside of the scraper 122, a spring is provided between the trigger block 127 and the scraper 122, and the separator 1 is provided with a pipeline for introducing cleaning liquid into the multiple first guide grooves 124.

[0066] Furthermore, when the tar purification work is carried out, static electricity is first introduced into the inner wall of the separator 1, and then the newly generated straw gas is introduced into the separator 1 through the air inlet pipe. The gas flows along the inner wall of the separator 1. The inclined scraper 12 is roughly the same as the airflow direction, and will not hinder the airflow along the inner wall of the separator 1. The tar in the airflow is adsorbed by the static electricity on the inner wall of the separator 1, and the tar adheres to the inner wall of the separator 1. After flowing along the inner wall of the separator 1 for a distance, the gas is gradually separated from the inner wall of the separator 1, and the gas is discharged from the outlet pipe 113. The bottom of the outlet pipe 113 is located below the inlet pipe, which can prevent the gas entering from the inlet pipe from being discharged from the outlet pipe 113 without separation.

[0067] As the airflow flows along the air outlet pipe 113, the airflow pushes the impeller 114 in the air outlet pipe 113 to rotate, and the impeller 114 drives the driving rod 115 to rotate through the synchronous belt, and the driving rod 115 drives the sliding ring 116 to move back and forth along the sliding groove inside the hollow cavity 112 through the slider 1161. As the sliding ring 116 moves upward with the movable ring 117, the first tenon 118 on the movable ring 117 moves along the vertical portion 1122 of the second guide groove 1121, and the pair of paddles 119 on the movable ring 117 push the pair of pull blocks 131 to move. The arc-shaped paddles 119 have a good ability to resist the force from above, and can move upward with the pull block 131. The pair of pull blocks 131 The corresponding pair of scrapers 12 are driven downward by the pull rope 132, and the spring between the second tenon 123 on the scraper 12 and the separator 1 is stretched, and the scraper 12 scrapes off the tar attached to the inner wall of the separation chamber 111. During the movement of the scraper 12, the push of the second tenon 123 pushes the sealing plate 125 to rotate inside the first guide groove 124, leaving space for the second tenon 123 to move, so that the second tenon 123 can move with the scraper 12. After the second tenon 123 passes, the sealing plate 125 seals the first guide groove 124 again under the action of the torsion spring, reducing the influence of the first guide groove 124 on the airflow, and the connecting strip 121 of the scraper 12 pushes the tar on the cylindrical part to move downward. Then the scraper 12 moves along the first guide groove 124 at the conical part of the separation chamber 111, the conical part pushes the connecting strip 121, the connecting strip 121 deforms and pushes the multiple scrapers 122 together, the scrapers 122 can block the tar, and prevent the tar from exceeding the connecting strip 121 and continuing to stay on the inner wall of the separation chamber 111. After the inner wall of the separation chamber 111 is cleaned, the static electricity can better release the attraction, and adsorb the tar and other particles in the airflow on the inner wall of the separator 1 to ensure the cleanliness of the straw gas. At the same time, the pipeline in the separator 1 introduces a cleaning agent into the first guide groove 124, and the cleaning agent flows along the first guide groove 124 to remove the tar accumulated in the first guide groove 124. The cleaning liquid continues to flow downward and enters the second tenon block 123. At the same time, as the multiple scraper blades 122 on the connecting strip 121 approach each other, the scraper blades 122 push the trigger blocks 127 on the adjacent scraper blades 122. The trigger blocks 127 push the sealing piece 128 to move. The sealing piece 128 is staggered with the drain port 129. The cleaning liquid in the second tenon block 123 is slowly discharged from the drain port 129 and cleans the scraper blades 122, removing the tar on the scraper blades 122. The cleaning liquid and tar gradually fall into the lower part 14, so that the staff can concentrate on cleaning. Only a pair of scrapers 12 are allowed to move synchronously, which can avoid the interference of multiple scrapers 12 in the area with a smaller diameter of the tapered portion of the separation chamber 111 while cleaning the inner wall of the separation chamber 111.

[0068] The first tenon block 118 continues to move along the vertical portion 1122 of the second guide groove 1121, and gradually pushes the movable piece 1124, so that the movable piece 1124 rotates and makes room for the first tenon block 118 to move. The first tenon block 118 continues to move upward and separates from the movable piece 1124. The movable piece 1124 rotates under the action of the torsion spring, returns to the vertical portion 1122 and blocks the vertical portion 1122. After the first tenon block 118 moves to the highest point, it gradually moves downward. The spring pulls the second tenon block 123 to gradually move upward with the scraper 12. The first tenon block 118 gradually contacts the movable piece 1124. The movable piece 1124 guides the first tenon block 118 to enter the inclined portion 1123. The first tenon block 118 moves along the inclined portion 1123 and gradually enters the next vertical portion 1122. The movable ring 11 The sliding ring 116 rotates relative to the sliding ring 116, and the paddle 119 on the movable ring 117 faces the next group of pulling blocks 131. The first tenon block 118 continues to move downward along the vertical portion 1122. When the paddle 119 approaches the pulling block 131 from above the pulling block 131, the horizontal portion of the pulling block 131 will first abut against the bottom center of the paddle 119, and the paddle 119 will be deformed and gradually staggered from the horizontal portion of the pulling block 131. After the paddle 119 is separated from the pulling block 131, the paddle 119 returns to its original shape under the action of its own elasticity and is located below the horizontal portion of the pulling block 131, so that the paddle 119 can paddle the next group of pulling blocks 131 to move. The number of the first tenon blocks 118 is greater than the number of the sliding grooves, which can ensure that there is always a first tenon block 118 located in the second guide groove 1121, and ensure that the first tenon block 118 can move along the second guide groove 1121.

[0069] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A tar purification system for a downdraft biomass gasifier, characterized in that: The separator comprises a plurality of scrapers which are centrally symmetrically arranged on the separator, a first guide groove which corresponds to the scrapers is opened on the inner wall of the separation chamber of the separator, two scrapers which are oppositely arranged form a group, and a plurality of groups of scrapers move back and forth alternately along the first guide groove, the scraper comprises a soft and elastic connecting strip which is slidably mounted on the inner wall of the separation chamber, a plurality of scrapers which are linearly arranged on the connecting strip, when the scraper moves along the cylindrical part of the separation chamber to the conical part of the separation chamber, the conical part pushes the connecting strip, the connecting strip is deformed and the plurality of scrapers on the connecting strip are brought closer; A hollow cavity is provided inside the separator, the hollow cavity is arranged outside the separation cavity, a pulling block corresponding to the scraper is movably arranged inside the hollow cavity, and the pulling block moves vertically upward inside the hollow cavity to move the scraper; A sliding ring is slidably arranged inside the hollow cavity, and a movable ring is rotatably arranged on the sliding ring, and the movable ring moves to make two pulling blocks corresponding to a pair of the scrapers move synchronously; The movable ring is provided with a pair of paddles for moving the pull block, and the paddles include the following two states: In the first state, the movable ring and the paddles move upward, and the two paddles push one pair of the pull blocks upward; In the second state, the movable ring and the paddles move downward, and the movable ring rotates relative to the sliding ring so that the two paddles face the next pair of pull blocks; The movable ring is provided with a first tenon block, and the side wall of the hollow cavity is provided with a second guide groove for guiding the first tenon block, the second guide groove includes vertical portions distributed in a circumferential array and an inclined portion for connecting two adjacent vertical portions; The plectrum is specifically an elastic arc-shaped piece, and the opening of the arc-shaped piece faces upward.

2. The tar purification system of a downdraft biomass gasifier according to claim 1, characterized in that: A driving rod for driving the sliding ring to move is rotatably arranged inside the separator, and an impeller for driving the driving rod to rotate is rotatably arranged inside the air outlet pipe of the separator.

3. The tar purification system of a downdraft biomass gasifier according to claim 1, characterized in that: A plurality of sealing plates for sealing the first guide groove are symmetrically and movably arranged inside the first guide groove.

4. The tar purification system of a downdraft biomass gasifier according to claim 3, characterized in that: The scraper is provided with a second tenon block extending into the first guide groove, and the second tenon block is provided with a push block for pressing the sealing plate to rotate toward the first guide groove.

5. The tar purification system of a downdraft biomass gasifier according to claim 4, characterized in that: The second tenon block is provided with a cavity for storing cleaning liquid, the scraper blade is provided with a drain port for the cleaning liquid to flow out, and a plurality of scrapers are brought together to allow the cleaning liquid in the second tenon block to be discharged from the drain port.

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