A boiler flue gas recirculation system capable of adjusting the oxygen content of the flue gas

Abstract

The application relates to a boiler flue gas recirculation system capable of adjusting the oxygen content of flue gas, and relates to the technical field of the boiler flue gas recirculation system, which comprises an air outlet pipe, an air return fan, a filtering and adjusting device, the filtering and adjusting device comprises: a filter plate which is slidably arranged on the air outlet pipe and is used for filtering; a moving block which is slidably arranged on the air outlet pipe; a linkage assembly which is arranged on the moving block and is connected with the filter plate; a reaction plate which is rotatably arranged on the moving block and is used for removing oxygen; a cleaning mechanism which is arranged on the air outlet pipe and is used for impurities and reactants; a rotating assembly which is arranged on the moving block and is used for driving the reaction plate to rotate; and a detection assembly which is arranged on the air outlet pipe and is used for detecting the oxygen content. The air return fan is started, flue gas is filtered through the filter plate, then the reaction plate is used for removing oxygen in the flue gas, so as to control the oxygen content in the flue gas, and energy saving, emission reduction and environmental protection are realized.

Description

Technical Field

[0001] This application relates to the technical field of boiler flue gas recirculation systems, and in particular to a boiler flue gas recirculation system capable of regulating the oxygen content of flue gas. Background Technology

[0002] For ultra-low nitrogen oxide emissions, reducing nitrogen oxide formation at the source is the most important control measure. Flue gas recirculation (FGR) technology can reduce the oxygen content in the air, creating a low-oxygen combustion process and reducing the initial formation of nitrogen oxides, making it an important means of achieving stratified combustion. Simultaneously, FGR technology can also influence boiler operating bed temperature, ash combustible content, and flue gas temperature, creating a suitable temperature window for efficient non-linear combustion recombinant nitrogen oxide (SNCR) denitrification, making it a crucial technology for achieving a balance between energy conservation, emission reduction, and environmental protection.

[0003] Flue gas recirculation (FGR) technology has encountered some problems in practical applications. FGR requires the operation of a fan to circulate the flue gas. However, the flue gas contains a large number of impurities, which easily adhere to the fan, reducing its air delivery efficiency and the utilization efficiency of the flue gas, resulting in energy waste. At the same time, the flue gas also contains a large amount of oxygen, which increases the generation of nitrogen oxides. However, the amount of oxygen cannot be too low for the flue gas to burn properly. Therefore, controlling the oxygen content of the flue gas is essential to save energy, thereby achieving energy conservation, emission reduction, and environmental protection. Summary of the Invention

[0004] In order to achieve energy conservation, emission reduction and environmental protection, this application provides a boiler flue gas recirculation system that can regulate the oxygen content of flue gas.

[0005] This application provides a boiler flue gas recirculation system capable of adjusting the oxygen content of flue gas, which adopts the following technical solution:

[0006] A boiler flue gas recirculation system capable of regulating the oxygen content of flue gas includes an outlet pipe for connecting to the outlet of the boiler body flue, a return air fan installed on the outlet pipe and for connecting to the inlet of the boiler body flue, and a filter regulating device installed on the outlet pipe, the filter regulating device comprising:

[0007] A filter plate, which is slidably disposed on the exhaust pipe and is used to filter the flue gas;

[0008] A movable block is slidably disposed on the air outlet pipe and the sliding direction is opposite to the sliding direction of the filter plate;

[0009] A linkage component is disposed on the moving block and connected to the filter plate, thereby causing the moving block to generate a restoring force.

[0010] A reaction plate, which is rotatably mounted on a moving block and used to react with oxygen to remove oxygen, and flue gas is filtered by the filter plate and then moved to the reaction plate to remove oxygen;

[0011] A cleaning mechanism is installed on the exhaust pipe and is activated after the flue gas pushes the filter plate to move to clean impurities on the filter plate and reactants on the reaction plate.

[0012] A rotating assembly, which is mounted on a movable block and is used to drive the reaction plate to rotate;

[0013] A detection component is installed on the exhaust pipe and is used to detect the oxygen content of the flue gas after passing through the reaction plate. It is also electrically connected to the rotating component and the return air fan.

[0014] By adopting the above technical solution, the return air fan starts, the flue gas is filtered through the filter plate, and then the flue gas moves to the reaction plate to react, thereby removing oxygen from the flue gas. Then the flue gas moves back to the boiler body for recycling after passing through the return air fan. In this way, the flue gas is filtered first to remove oxygen, which reduces the probability of the return air fan being blocked, and also allows more oxygen to react with the reaction plate for removal, improving the recovery effect of the flue gas. At the same time, the detection component detects the oxygen content in the flue gas after passing through the reaction plate. When the oxygen content is high, the rotation component starts to drive the reaction plate to rotate, increasing the contact area between the reaction plate and oxygen, so that more oxygen is removed. At the same time, the speed of the return air fan slows down, thereby improving the oxygen removal effect. When the oxygen content is low, the operation is reversed, thus controlling the oxygen content as needed, thereby achieving energy saving, emission reduction and environmental protection.

[0015] The filter plate removes impurities, while the reaction plate removes oxygen. After a period of time, the impurities clog the filter plate, and the reactants from the reaction plate also adhere to it, reducing the removal efficiency of impurities and oxygen. Therefore, the flue gas pushes the filter plate to move, which in turn moves the reaction plate. Then, the cleaning mechanism is activated to clean the impurities on the filter plate and the reactants from the reaction plate. When the force of the flue gas on the filter plate decreases, the filter plate and the moving plate return to their original positions under the restoring force of the linkage component, thereby further improving the removal efficiency of impurities and oxygen in the flue gas. This further achieves energy saving, emission reduction, and environmental protection. Moreover, the cleaning mechanism is activated again after the flue gas pushes the filter plate to move, thus saving the energy loss generated by the continuous operation of the cleaning mechanism and achieving energy saving and emission reduction.

[0016] Optionally, the linkage component includes:

[0017] A linkage spring is provided on the air outlet pipe and connected to the movable block.

[0018] A linkage rope is mounted on the movable block and connected to the filter plate.

[0019] A guide wheel is rotatably mounted on the air outlet pipe, and the linkage rope passes around the guide wheel for guidance.

[0020] By adopting the above technical solution, the filter plate moves by pulling the moving block with the linkage rope. The moving block moves the reaction plate. At the same time, the moving block squeezes the linkage spring. After the push of the flue gas on the filter plate decreases, the reaction plate and the filter plate move back to their original positions under the action of the linkage spring.

[0021] Optionally, the cleaning mechanism includes:

[0022] A brush plate and a scraper are respectively vertically slidably disposed on a filter plate and a moving block and are used to clean impurities on the filter plate and scrape off reactants on the reaction plate.

[0023] A pushing component is disposed on the filter plate and the moving block and is used to push the brush plate and the scraper to move.

[0024] By adopting the above technical solution, the flue gas drives the filter plate to move, the filter plate drives the reaction plate to move, the movement and rotation of the filter plate drives the scraper to move and rotate simultaneously, and the movement of the reaction plate drives the brush plate to move. Then, the control push component is started to drive the brush plate and scraper to move down simultaneously. The movement of the brush plate is used to clean the impurities on the filter plate, while the movement of the scraper is used to scrape off the reactants on the reaction plate after reacting with oxygen, thereby achieving the removal of impurities on the filter plate and reactants on the reaction plate.

[0025] Optionally, the pushing component includes:

[0026] A rotating disk is rotatably mounted on a movable block, and the reaction plate is mounted on the rotating disk;

[0027] A connecting rod is disposed on the scraper and slides through the rotating disk;

[0028] The first push rod is mounted on the rotating disk and connected to the connecting rod.

[0029] The second push rod is mounted on the filter plate and connected to the brush plate.

[0030] By adopting the above technical solution, the first push rod is activated to drive the connecting rod to move, and the moving connecting rod drives the scraper to move. At the same time, the second push rod is activated to drive the brush plate to move. Therefore, the moving scraper is used to scrape off the reactants on the reaction plate after they have reacted with oxygen, while the moving brush plate is used to clean the impurities adhering to the filter plate. This achieves the cleaning of the reactants on the reaction plate and the impurities on the filter plate. At the same time, the scraper rotates with the rotation of the scraper, so that the scraper can also scrape off the reactants on the reaction plate after it rotates, thereby further realizing energy saving, emission reduction and environmental protection.

[0031] Optionally, both sides of the reaction plate can react after contact with oxygen, and two scrapers are provided to scrape off the reactants on both sides of the reaction plate.

[0032] By adopting the above technical solution, when one side wall of the reaction plate reacts with oxygen to form reactants, the reaction blocks the oxygen. Therefore, the rotating component is activated to drive the reaction plate to rotate, so that the two sides of the reaction plate are reversed. The unreacted side wall of the reaction plate continues to react with oxygen, while the two scrapers are used to scrape off the reactants on the two side walls of the reaction plate, thereby further improving the oxygen removal effect and achieving energy saving, emission reduction and environmental protection.

[0033] Optionally, the scraper includes:

[0034] The mounting part is disposed on the connecting rod;

[0035] A scraping section, which is slidably disposed on the mounting section;

[0036] A compression spring is provided on the mounting part and connected to the scraping part, so that the scraping part presses against the reaction plate to scrape off the reactants.

[0037] By adopting the above technical solution, the thickness of the reaction plate decreases as it reacts with oxygen. Therefore, the scraping part is pressed against the reaction plate under the action of the compression spring to scrape off the reactants on the reaction plate, thereby improving the removal effect of reactants and oxygen, and achieving energy conservation, emission reduction and environmental protection.

[0038] Optionally, the rotating assembly includes:

[0039] A worm gear, which is mounted on a rotating disk;

[0040] A rotating motor is mounted on a movable block;

[0041] A worm gear, which is mounted on the output shaft of a rotating motor and meshes with a worm wheel.

[0042] By adopting the above technical solution, the rotating motor starts and drives the worm gear to rotate, the worm gear rotates and drives the worm wheel to rotate, and the worm wheel rotates and drives the reaction plate to rotate. This achieves the goal of starting the rotating motor and driving the reaction plate to rotate. At the same time, the worm gear and worm wheel have a self-locking function, which further improves the stability of the position of the reaction plate after adjustment, further improves the oxygen removal effect, and achieves energy saving, emission reduction and environmental protection.

[0043] Optionally, the vent pipe is provided with a collection component for collecting impurities, the collection component comprising:

[0044] A collection box, which is slidably disposed on the exhaust pipe and is used to collect impurities that fall off the filter plate and precipitate in the flue gas;

[0045] A collection plate is disposed on the collection box and positioned against the air outlet pipe.

[0046] By adopting the above technical solution, the collection box collects impurities that fall from the filter plate, as well as impurities that settle down during the movement of flue gas. The collection plate is pulled to remove the collection box for cleaning. After cleaning, the collection box is slidably installed onto the exhaust pipe, thereby improving the collection effect of impurities and achieving energy conservation, emission reduction and environmental protection.

[0047] Optionally, the exhaust pipe is provided with a bent buffer section, and the filter plate and the reaction plate are located in the exhaust pipes on both sides of the buffer section, so that the flue gas moves in opposite directions through the exhaust pipes on both sides of the buffer section, and the collection box extends from below the filter plate to below the buffer section.

[0048] By adopting the above technical solution, the flue gas enters the buffer section after being filtered by the filter plate. The buffer section slows down the movement speed of the flue gas, allowing impurities in the flue gas to continue to settle and then move to the collection box for collection, thereby further improving the removal effect of impurities and achieving energy conservation, emission reduction and environmental protection.

[0049] Optionally, the collection box extends below the reaction plate and is used to collect reactants, and the collection box is provided with a separator to separate reactants and impurities.

[0050] By adopting the above technical solution, the collection box collects both impurities and reactants, thereby improving the collection effect of impurities and reactants. At the same time, since the impurities in the flue gas contain combustible substances, the separator separates the impurities and reactants, making it easier to recover the impurities for continued combustion, thus achieving energy conservation, emission reduction and environmental protection.

[0051] In summary, this application includes at least one of the following beneficial technical effects:

[0052] By starting the return air fan, the flue gas is filtered through the filter plate, and then the reaction plate removes oxygen from the flue gas. The flue gas is then moved into the boiler body for recovery, reducing the probability of the return air fan being blocked and allowing more oxygen to react with the reaction plate for removal, thus improving the flue gas recovery effect. At the same time, the detection component detects the oxygen content in the flue gas after passing through the reaction plate, thereby controlling the rotation component to drive the reaction plate to rotate and controlling the speed of the return air fan, thereby controlling the oxygen content in the flue gas, achieving energy saving, emission reduction and environmental protection. Attached Figure Description

[0053] Figure 1 This is a three-dimensional structural diagram of this application;

[0054] Figure 2 yes Figure 1 Enlarged diagram of section A in the middle;

[0055] Figure 3 This is a schematic diagram of the structure of the cleaning organization in this application;

[0056] Figure 4 This is a schematic diagram of the structure of the components collected in this application.

[0057] Reference numerals: 1. Outlet pipe; 11. First pipe; 12. Second pipe; 13. Buffer section; 14. Return air fan; 15. First moving hole; 16. Second moving hole; 17. Moving plate; 18. Mounting base; 19. Sensor; 2. Filter adjustment device; 21. Filter plate; 22. Moving block; 23. Reaction plate; 24. Rotating shaft; 3. Linkage assembly; 31. Linkage spring; 32. Linkage rope; 33. Guide wheel; 4. Cleaning mechanism; 41. Brush plate; 42. Scraper; 43. Mounting section; 44. Scraping section; 45. Compression spring; 5. Pushing assembly; 51. Rotating disk; 52. Connecting rod; 53. First push rod; 54. Second push rod; 6. Rotating assembly; 61. Worm gear; 62. Rotating motor; 63. Worm; 7. Collection assembly; 71. Collection box; 72. Collection plate; 74. Divider plate. Detailed Implementation

[0058] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0059] This application discloses a boiler flue gas recirculation system capable of adjusting the oxygen content of flue gas.

[0060] Reference Figure 1 The boiler flue gas recirculation system capable of regulating the oxygen content of flue gas includes an outlet pipe 1 for connecting to the outlet of the boiler body flue, a return air fan 14 installed on the outlet pipe 1 and for connecting to the inlet of the boiler body flue, and a filter regulating device 2 installed on the outlet pipe 1.

[0061] Reference Figure 1 The exhaust pipe 1 includes a first pipe 11 and a second pipe 12 arranged parallel to each other. The first pipe 11 and the second pipe 12 are horizontal and have a square cross-section. A bent buffer section 13 is integrally provided on the end of the first pipe 11 and the second pipe 12 that are close to each other. The end of the first pipe 11 away from the buffer section 13 is fixedly connected to the flue outlet of the boiler body. The return air fan 14 is fixedly installed on the end of the second pipe 12 away from the buffer section 13. When the return air fan 14 is started, the flue gas enters the first pipe 11. Then the flue gas moves to the buffer section 13 and collides with the inner wall of the buffer section 13, which slows down the movement speed of the flue gas. Finally, the flue gas in the second pipe 12 enters the boiler body for recycling. At the same time, the movement direction of the flue gas when passing through the first pipe 11 and the second pipe 12 is opposite.

[0062] Reference Figure 1 The filter adjustment device 2 includes a filter plate 21, a moving block 22, and a linkage assembly 3. A first moving hole 15 is provided on the upper surface of the first pipe 11, and a second moving hole 16 is provided on the upper surface of the second pipe 12. A moving plate 17 is horizontally slidably installed on the opposite side walls of the first moving hole 15, and the lower surface of the moving plate 17 communicates with the inside of the first pipe 11 and blocks the first moving hole 15. The moving block 22 is horizontally slidably installed on the opposite side walls of the second moving hole 16, and the lower surface of the moving block 22 communicates with the inside of the second pipe 12 and blocks the second moving hole 16. At the same time, the sliding directions of the moving plate 17 and the moving block 22 are parallel to the center lines of the first pipe 11 and the second pipe 12.

[0063] Reference Figure 1 The filter plate 21 is fixedly installed on the lower surface of the movable plate 17. The upper surface of the filter plate 21 is in contact with the inner top wall of the first pipe 11, while the opposite side walls of the filter plate 21 are in contact with the opposite side walls of the first pipe 11. The filter plate 21 is used to filter the flue gas entering the first pipe 11. The linkage component 3 is set on the movable block 22 and connected to the filter plate 21. The linkage component 3 causes the filter plate 21 and the movable block 22 to move simultaneously and in opposite directions. At the same time, the linkage component 3 also causes the movable block 22 to generate a restoring force.

[0064] Reference Figure 1 and Figure 2 The linkage component 3 includes a linkage spring 31, a linkage rope 32, and a guide wheel 33. Two connecting blocks are fixedly installed horizontally at intervals on the moving block 22. The linkage spring 31 is fixedly installed on the side wall of the second moving hole 16 away from the buffer part 13 and is fixedly connected to the side wall of the connecting block therein. The guide wheel 33 is rotatably installed on the upper surface of the second tube 12 and is in a vertical state. One end of the linkage rope 32 is fixedly installed on the side wall of the other connecting block and passes around the guide wheel 33 and is fixedly connected to the upper surface of the moving plate 17.

[0065] Reference Figure 2and Figure 3 The filter adjustment device 2 also includes a reaction plate 23 and a cleaning mechanism 4. The reaction plate 23 is vertically rotated and installed on the lower surface of the moving block 22 via a rotating shaft 24. The top of the reaction plate 23 contacts the inner top wall of the second pipe 12. When the reaction plate 23 rotates to a position where its length direction is perpendicular to the center line of the second pipe 12, both ends of the reaction plate 23 contact the opposite side walls of the second pipe 12. At the same time, multiple through holes for flue gas to pass through are evenly opened on the reaction plate 23. The reaction plate 23 is a metal plate that can react with oxygen. The reaction plate 23 can be a copper plate or an aluminum plate, etc., and the reaction plate 23 is preferably an aluminum plate. The aluminum plate reacts with oxygen at room temperature, while the flue gas has a higher temperature when it is output, which makes the reaction between oxygen and aluminum plate more intense, thereby improving the removal effect of oxygen.

[0066] Reference Figure 1 and Figure 3 The cleaning mechanism 4 is installed on the exhaust pipe 1. When the flue gas pushes the filter plate 21 to move, the cleaning mechanism 4 starts to clean the impurities adhering to the filter plate 21 and the reactants on the reaction plate 23 after reacting with oxygen. The mounting base 18 is fixedly installed on the upper surface of the first pipe 11. At the same time, the sensor 19, which is electrically connected to the cleaning mechanism 4, is fixedly installed on the mounting base 18. When the filter plate 21 moves and drives the moving plate 17 to move, the moving plate 17 presses against the mounting base 18 to position the filter plate 21 and the reaction plate 23. At the same time, the moving plate 17 contacts the sensor 19, and the sensor 19 controls the cleaning mechanism 4 to start cleaning the filter plate 21 and the reaction plate 23.

[0067] Reference Figure 1 , Figure 2 and Figure 3 When the filter plate 21 is clogged with impurities, the force of the flue gas on the filter plate 21 increases. Therefore, the flue gas pushes the filter plate 21 to move closer to the buffer section 13. The movement of the filter plate 21 pulls the moving block 22 away from the buffer section 13 through the linkage rope 32. The movement of the moving block 22 compresses the linkage spring 31, causing the moving plate 17 to press against the mounting base 18 and contact the sensor 19, thereby positioning the filter plate 21 and the reaction plate 23. At the same time, the sensor 19 triggers a signal to the cleaning mechanism 4, and the cleaning mechanism 4 starts to clean the impurities on the filter plate 21 and the reactants on the reaction plate 23.

[0068] Reference Figure 1 and Figure 3The cleaning mechanism 4 includes a brush plate 41, a scraper 42, and a pushing assembly 5. The brush plate 41 is vertically slidably mounted on the moving plate 17 and is located on the side of the filter plate 21 away from the buffer part 13. The brush plate 41 is used to clean impurities on the filter plate 21. The scraper 42 is vertically slidably mounted on the moving block 22 and there are two scrapers 42 located on both sides of the reaction plate 23. The two scrapers 42 are used to scrape off the reactants on the opposite side walls of the reaction plate 23.

[0069] Reference Figure 1 , Figure 2 and Figure 3 The pushing component 5 is set on the moving plate 17 and the moving block 22 and is used to push the brush plate 41 and the scraper 42 to move. The pushing component 5 includes a rotating disk 51, a connecting rod 52, a first push rod 53 and a second push rod 54. The rotating disk 51 is rotatably mounted on the lower surface of the moving block 22. The rotating disk 51 is in a vertical state and its two ends are flush with the upper and lower surfaces of the moving block 22 respectively. The lower surface of the rotating disk 51 is located above the inner top wall of the second tube 12. At the same time, the rotating shaft 24 is coaxially mounted on the lower surface of the rotating disk 51 and extends above the rotating disk 51.

[0070] Reference Figure 2 and Figure 3 The connecting rod 52 is eccentrically slidably mounted on the rotating disk 51, and the sliding direction of the connecting rod 52 is parallel to the axis of the rotating shaft 24. Two scrapers 42 are installed on the bottom end of the connecting rod 52. The scraper 42 includes a mounting part 43, a scraping part 44 and a compression spring 45. The mounting part 43 is fixedly installed on the bottom end of the connecting rod 52, while the scraping part 44 is horizontally slidably installed on the side wall of the mounting part 43, and the sliding direction of the scraping part 44 is along the direction of approaching or moving away from the reaction plate 23. At the same time, the scraping part 44 is used to scrape off the reactants on the reaction plate 23 after reacting with oxygen. The two ends of the compression spring 45 are fixedly connected to the mounting part 43 and the scraping part 44 respectively, and the scraping part 44 is pressed against the reaction plate 23 under the action of the compression spring 45, so as to scrape off the reactants.

[0071] Reference Figure 2 and Figure 3 The top ends of the two connecting rods 52 are fixedly connected together. The first push rod 53 is fixedly installed on the upper surface of the rotating disk 51, and the piston rod of the first push rod 53 is vertically upward and fixedly connected to the two connecting rods 52. The second push rod 54 is fixedly installed on the upper surface of the moving plate 17, and the piston rod of the second push rod 54 is fixedly connected to the brush plate 41. A control board for controlling the start and stop of the first push rod 53 and the second push rod 54 is fixedly installed on the second tube 12, and the sensor 19 is electrically connected to the control board.

[0072] Reference Figure 1 and Figure 3When the filter plate 21 moves and causes the moving plate 17 to contact the sensor 19, the control board starts and drives the first push rod 53 and the second push rod 54 to start simultaneously. The brush plate 41 and the two scrapers 42 move down at the same time. The brush plate 41 cleans the impurities on the filter plate 21, while the scrapers 42 are used to scrape off the reactants on the reaction plate 23.

[0073] Reference Figure 1 and Figure 2 The filter adjustment device 2 also includes a rotating assembly 6 and a detection assembly. The rotating assembly 6 is mounted on the moving block 22 and is used to drive the reaction plate 23 to rotate. The rotating assembly 6 can drive the reaction plate 23 to rotate and achieve reversal, so that the opposite side walls of the reaction plate 23 can interchange positions, allowing both side walls of the reaction plate 23 to come into contact with oxygen for reaction. The rotating assembly 6 includes a worm gear 61, a rotating motor 62, and a worm 63. The worm gear 61 is keyed to the rotating shaft 24 and is located above the rotating disk 51. The rotating motor 62 is fixedly mounted on the upper surface of the moving block 22. The worm 63 is mounted on the output shaft of the rotating motor 62, and the worm... The meshing of worm gear 63 with worm wheel 61 enables self-locking. The starting of motor 62 drives worm gear 63 to rotate, which in turn drives worm wheel 61 and shaft 24 to rotate. The rotation of shaft 24 drives reaction plate 23 to rotate. When reaction plate 23 rotates to a position where its length is perpendicular to the center line of the second tube 12, the contact area between reaction plate 23 and oxygen is maximized, resulting in the best oxygen removal effect. However, as reaction plate 23 rotates, the contact area between reaction plate 23 and oxygen decreases, thus reducing the oxygen removal effect. This ensures that the oxygen content in the flue gas remains within the required range, preventing it from becoming too high or too low.

[0074] Reference Figure 1 and Figure 3 The detection component is an oxygen detector, which is fixedly installed on the inner wall of the second pipe 12 and located between the reaction plate 23 and the return air fan 14. The oxygen detector is used to detect the oxygen content in the flue gas after passing through the reaction plate 23. The outlet pipe 1 is fixedly equipped with a control box that controls the start and stop of the rotating motor 62 and the speed of the return air fan 14. The oxygen detector is electrically connected to the control box. When the oxygen detector detects a high oxygen content, the rotating motor 62 starts and drives the reaction plate 23 to rotate, which increases the contact area between the side wall of the reaction plate 23 and the oxygen. At the same time, the speed of the return air fan 14 slows down, which slows down the movement speed of the flue gas, thereby improving the oxygen removal effect. Conversely, the operation is reversed.

[0075] Reference Figure 1 and Figure 4The exhaust pipe 1 is equipped with a collection assembly 7 for collecting impurities. The collection assembly 7 includes a collection box 71 and a collection plate 72. A collection hole is provided on the side wall of the buffer part 13 and below the filter plate 21 and the reaction plate 23. The collection box 71 is slidably installed on the collection hole. Two collection boxes 71 are provided and fixedly connected together near the collection hole. One collection box 71 extends below the filter plate 21 and is used to collect impurities that fall on the filter plate 21. At the same time, the collection box 71 is located at the buffer part 13, so that the collection box 71 can also collect impurities that settle during the movement of flue gas. The other collection box 71 extends below the reaction plate 23 and has a partition plate 74 fixedly installed inside. The collection box 71 can also collect reactants that fall on the reaction plate 23. The partition plate 74 is used to separate impurities and reactants.

[0076] The working principle of this application embodiment is as follows:

[0077] When the return air fan 14 starts, the flue gas enters the first pipe 11 and is filtered by the filter plate 21. Then, the flue gas passes through the buffer section 13 and moves to the second pipe 12. The oxygen in the flue gas then reacts with the reaction plate 23 to remove the oxygen from the flue gas. The oxygen detector then detects the oxygen content in the flue gas, thereby controlling the start of the rotating motor 62 to adjust the angle of the reaction plate 23 and the moving speed of the flue gas, so that the oxygen content in the flue gas is within the required range. The flue gas that meets the requirements is then moved back to the boiler body for recycling, thus achieving energy saving, environmental protection and environmental protection.

[0078] When the filter plate 21 is clogged by a large amount of impurities, the flue gas pushes the filter plate 21 closer to the buffer section 13. The movement of the filter plate 21 pulls the reaction plate 23 away from the buffer section 13. The movement of the filter plate 21 causes the moving plate 17 to press against the mounting base 18 for positioning. The moving plate 17 contacts the sensor 19, so the first push rod 53 and the second push rod 54 are activated simultaneously. The brush plate 41 moves down to clean the impurities on the filter plate 21, while the scraper 42 is used to scrape off the reactants on the reaction plate 23. The cleaned impurities and reactants fall into the collection box 71 for collection. After cleaning, the first push rod 53 and the second push rod 54 are activated to move the brush plate 41 and the scraper 42 upward. The pushing force of the flue gas on the filter plate 21 decreases, and the filter plate 21 and the reaction plate 23 move back to their original positions under the action of the linkage spring 31. This further improves the removal effect of impurities and oxygen in the flue gas, thereby achieving energy saving, environmental protection and environmental protection.

[0079] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A boiler flue gas recirculation system capable of regulating the oxygen content of flue gas, comprising an outlet pipe (1) for connecting to the outlet of the boiler body flue, and a return air fan (14) disposed on the outlet pipe (1) and for connecting to the inlet of the boiler body flue, characterized in that: A filter adjustment device (2) is provided on the air outlet pipe (1), and the filter adjustment device (2) includes: A filter plate (21) is slidably disposed on the exhaust pipe (1) and used to filter the flue gas; The movable block (22) is slidably disposed on the air outlet pipe (1) and the sliding direction is opposite to the sliding direction of the filter plate (21); Linkage component (3), which is disposed on the moving block (22) and connected to the filter plate (21) and causes the moving block (22) to generate a restoring force; The reaction plate (23) is rotatably mounted on the moving block (22) and is used to react with oxygen to remove oxygen. The flue gas is filtered by the filter plate (21) and then moved to the reaction plate (23) to remove oxygen. Cleaning mechanism (4) is installed on the exhaust pipe (1) and is activated to clean impurities on the filter plate (21) and reactants on the reaction plate (23) after the flue gas pushes the filter plate (21) to move. Rotating assembly (6), which is mounted on the moving block (22) and is used to drive the reaction plate (23) to rotate; The detection component is installed on the exhaust pipe (1) and is used to detect the oxygen content of the flue gas after passing through the reaction plate (23) and is electrically connected to the rotating component (6) and the return air fan (14). The linkage component (3) includes: Linkage spring (31), the linkage spring (31) is disposed on the air outlet pipe (1) and connected to the moving block (22); Linkage rope (32), which is mounted on the movable block (22) and connected to the filter plate (21); The guide wheel (33) is rotatably mounted on the air outlet pipe (1), and the linkage rope (32) passes around the guide wheel (33) for guidance.

2. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 1, characterized in that: The cleaning mechanism (4) includes: The brush plate (41) and scraper (42) are vertically slidably disposed on the filter plate (21) and the moving block (22) respectively, and are used to clean the impurities on the filter plate (21) and scrape off the reactants on the reaction plate (23); A pushing component (5) is disposed on the filter plate (21) and the moving block (22) and is used to push the brush plate (41) and the scraper (42) to move.

3. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 2, characterized in that: The actuation component (5) includes: A rotating disk (51) is rotatably mounted on a movable block (22), and a reaction plate (23) is mounted on the rotating disk (51). A connecting rod (52) is disposed on a scraper (42) and slides through a rotating disk (51); The first push rod (53) is mounted on the rotating disk (51) and connected to the connecting rod (52); The second push rod (54) is disposed on the filter plate (21) and connected to the brush plate (41).

4. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 3, characterized in that: Both sides of the reaction plate (23) can react after contact with oxygen. Two scrapers (42) are provided and used to scrape off the reactants on both sides of the reaction plate (23).

5. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 3, characterized in that: The scraper (42) includes: Mounting part (43), which is provided on the connecting rod (52); A scraping part (44) is slidably disposed on the mounting part (43); A compression spring (45) is provided on the mounting part (43) and connected to the scraping part (44) so ​​that the scraping part (44) presses against the reaction plate (23) to scrape off the reactants.

6. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 1, characterized in that: The rotating assembly (6) includes: A worm gear (61) is mounted on a rotating disk (51); A rotating motor (62) is mounted on a moving block (22); The worm (63) is mounted on the output shaft of the rotating motor (62) and meshes with the worm wheel (61).

7. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 1, characterized in that: The vent pipe (1) is provided with a collection component (7) for collecting impurities, the collection component (7) comprising: Collection box (71), which is slidably disposed on the exhaust pipe (1) and is used to collect impurities that fall from the filter plate (21) and are deposited in the flue gas; A collection plate (72) is disposed on a collection box (71) and positioned against an air outlet pipe (1).

8. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 7, characterized in that: The exhaust pipe (1) is provided with a bent buffer section (13). The filter plate (21) and the reaction plate (23) are located in the exhaust pipes (1) on both sides of the buffer section (13), so that the flue gas moves in opposite directions through the exhaust pipes (1) on both sides of the buffer section (13). The collection box (71) extends from below the filter plate (21) to below the buffer section (13).

9. A boiler flue gas recirculation system capable of adjusting flue gas oxygen content according to claim 8, characterized in that: The collection box (71) extends below the reaction plate (23) and is used to collect the reactants. The collection box (71) is provided with a separator (74) to separate the reactants and impurities.

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