An exhaust gas treatment device after the catalytic oxidation reaction of nitrogen oxides

Abstract

The present invention discloses a device for treating waste gas after a catalytic oxidation reaction of nitrogen oxides, which relates to the technical field of filter bag dust collectors. The device comprises a dust box and a purification chamber, comprising a first chamber and a second chamber that are opened in the dust box and separated from each other; a filter bag assembly arranged in the dust box, comprising an inner filter cartridge and an outer filter bag that is arranged around the inner filter cartridge and encloses a light dust storage area. The device for treating waste gas after a catalytic oxidation reaction of nitrogen oxides uses a three-way valve to allow two chambers to be alternately purified. When one chamber needs to clean the dust in the filter bag assembly, the other chamber is activated, reducing the time required to wait for the sedimentation to end. Furthermore, the filter bag assembly is used to separate light and heavy dust, and the folding of the outer filter bag shakes off the heavy dust and compresses the light dust, thereby helping the light dust to clump, reducing the content of light dust floating in the chamber, and increasing the dust sedimentation rate.

Description

Technical Field

[0001] The present invention relates to the technical field of filter bag dust collectors, and in particular to a device for treating waste gas after a catalytic oxidation reaction of nitrogen oxides. Background Art

[0002] Factory emissions, especially in high-emission industries like thermal power plants, chemical plants, and steel mills, generate large amounts of nitrogen oxides through the combustion of fossil fuels. To prevent direct release into the atmosphere and the resulting serious air pollution, catalytic oxidation is typically used to convert NO into NO2 for subsequent treatment. The treated exhaust gas then passes through a bag filter to remove dust before being released into the air once it meets standards.

[0003] In conjunction with publication number CN113546481A, the publication date discloses a bag filter bag, comprising a bag body, a frame and a connecting head mounted to the bag body; the connecting head is arranged at the top of the frame; a plurality of annular positioning hooks are arranged on the top of the bag body; a plurality of groups of vertically arranged shaping wires and annular drawstrings are arranged inside the bag body; a counterweight block is arranged on the shaping wire; a vertical air duct is arranged inside the bag body; a plurality of groups of interconnected ducts are arranged on the air duct, and the other end of the duct is connected to the bag body; the duct includes an elastic part and a connecting part; the elastic part extends and retracts left and right along the horizontal direction; a limiting block is arranged inside the connecting part, and an inner lining layer is arranged on the inner wall of the connecting part; an active ball is arranged inside the connecting part, and the active ball slides along the inner lining layer. The above technology can hit the bag body during the spraying and cleaning, thereby increasing the range of movement of the bag body, thereby improving the cleaning effect, and combined with the nozzle to spray air into the air duct, the gas in the connecting part is discharged through the air vent, and the bag body expands rapidly in a short time.

[0004] However, in the prior art including the above-mentioned patents, since the exhaust gas undergoes high-temperature combustion, the light dust particles therein have a higher temperature and a lower density, and the volume of the particles expands, similar to a small "hot air balloon". The dust is sucked by the filter bag opening and adheres to the outer wall of the filter bag. Among them, the heavy dust is more likely to agglomerate and further increase its own weight due to its greater density, but the nuclei of the light dust still maintain a distance due to the volume expansion, making it difficult for the light dust to agglomerate. When a counterweight is used to impact the bag body, the agglomerated heavy dust is shaken off and settles, while the light dust floats in the filter bag dust collector under the effect of thermal buoyancy. Since the filter bag dust collector is always maintained at a high temperature due to the exhaust waste heat, thermal buoyancy always exists, making it difficult to make the light dust fall quickly by sedimentation.

[0005] When the pulse jet tube that comes with the filter bag is ejecting air, the gas will spread outward along the surface of the filter bag. Light dust will remain suspended after being blown away, but heavy dust that has already settled may float again under the blowing of the airflow, causing the concentration of floating dust in the filter bag dust collector to decrease and the actual amount of dust removed by settling to decrease. As the exhaust gas continues to be discharged from the filter bag dust collector, the floating dust in the filter bag dust collector will gradually increase, making the filter bag increasingly susceptible to dust. The frequency of pulse jets needs to be gradually increased, and the number of settling and cleaning times increases, making the waiting time for settling longer. Summary of the Invention

[0006] The object of the present invention is to provide a device for treating exhaust gas after catalytic oxidation reaction of nitrogen oxides, so as to solve the above-mentioned problems.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an exhaust gas treatment device after a catalytic oxidation reaction of nitrogen oxides, comprising a dust removal box and a purification chamber, including a first chamber and a second chamber that are opened in the dust removal box and separated from each other, and an air inlet pipe that alternately supplies air to the first chamber and the second chamber, and a three-way valve that is switched under program control is provided on the air inlet pipe;

[0008] The filter bag assembly is arranged in the dust removal box, which includes an inner filter cartridge and an outer filter bag arranged around the inner filter cartridge to enclose a light dust storage area, and an intermittently open movable bottom plate is installed at the bottom of the light dust storage area;

[0009] The outer filter bag is in a folded state in the axial direction;

[0010] The movable port is fixedly arranged at the port of the outer filter bag and is driven to move in the vertical direction.

[0011] Preferably, a folding assembly for supporting the outer filter bag is further included, which includes a first folding rod and a second folding rod hinged to each other, and a sliding piece that slides along the outer wall of the inner filter cartridge is provided at the connection position of each folding assembly.

[0012] Preferably, the first folding rod and the second folding rod form an acute angle structure obliquely downward when folded.

[0013] Preferably, a rotating wheel is rotatably provided on the slide and rotates as the folding assembly unfolds.

[0014] Preferably, it further comprises keels arranged in a circumferential array on the inner filter cartridge.

[0015] Preferably, the filter further comprises a rotating member which is rotatably arranged relative to the inner filter cartridge and forms a blocking fit with the movable opening, and the rotating member and the movable bottom plate keep synchronous movement.

[0016] Preferably, it further comprises a hook-shaped portion, on which a first spring for maintaining a predetermined height is provided, and the rotating member has a station in its movable stroke for engaging with the hook-shaped portion.

[0017] Preferably, the device further comprises a transmission rod slidably arranged in a vertical direction, and the hook-shaped portion is fixedly arranged at the end of the transmission rod.

[0018] Preferably, it also includes an inclined block that slides radially along the port of the inner filter cartridge and is used to clamp the movable port.

[0019] Preferably, the inclined block and the transmission rod move synchronously.

[0020] In the above-mentioned technical solution, the present invention provides an exhaust gas treatment device after the catalytic oxidation reaction of nitrogen oxides, which has the following beneficial effects: the configuration of a three-way valve allows the two chambers to be cleaned alternately. When one chamber needs to clean the dust in the filter bag assembly, the other chamber is activated, reducing the time required to wait for the sedimentation to complete. The filter bag assembly also separates light and heavy dust. The folding of the outer filter bag shakes off the heavy dust and compresses the light dust, helping the light dust to agglomerate, reducing the amount of light dust floating in the chamber, and increasing the dust settling rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 An overall three-dimensional schematic diagram provided for an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the overall longitudinal cross-sectional structure provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the overall three-dimensional rear structure provided by an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of a cross-sectional structure in the overall width direction provided by an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of the filter bag assembly structure in a default state provided by an embodiment of the present invention;

[0027] Figure 6 A schematic structural diagram of a filter bag assembly in a folded state provided by an embodiment of the present invention;

[0028] Figure 7A schematic diagram of the keel and movable opening structure provided in an embodiment of the present invention;

[0029] Figure 8 A schematic diagram of the keel and folding assembly structure provided by an embodiment of the present invention;

[0030] Figure 9 A schematic diagram of the keel structure provided by an embodiment of the present invention;

[0031] Figure 10 A schematic diagram of the structure of the keel, inner filter cartridge, and movable port provided in an embodiment of the present invention;

[0032] Figure 11 Schematic diagram of the first folding rod, the second folding rod and the sliding member structure provided by an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Dust removal box; 11. First chamber; 12. Second chamber; 13. Purification chamber; 14. Fixed partition; 15. Movable plate; 16. Drive unit; 2. Air inlet pipe; 21. Side pipe; 3. Three-way valve; 4. Lower ash hopper; 5. Filter bag assembly; 51. Inner filter cartridge; 52. Fixed port; 521. Keel; 53. Movable port; 531. Slot; 54. First folding rod; 55. Second folding rod; 56. Sliding piece; 561. Scraper; 562. Ratchet; 563. Rotating wheel; 564. Elastic piece; 57. Outer filter bag; 58. Support frame; 581. First spring; 582. Transmission rod; 583. Hook-shaped portion; 584. Rotating piece; 585. Second spring; 586. Slide rail; 587. Inclined block; 59. Movable bottom plate; 591. Movable rod. DETAILED DESCRIPTION

[0035] 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.

[0036] like Figures 1-11 As shown, an exhaust gas treatment device after a catalytic oxidation reaction of nitrogen oxides includes a dust removal box 1 and a purification chamber 13, including a first chamber 11 and a second chamber 12 opened in the dust removal box 1 and separated from each other, and an air inlet pipe 2 that alternately supplies air to the first chamber 11 and the second chamber 12, and is provided with a three-way valve 3 that is switched under program control;

[0037] The filter bag assembly 5 disposed in the dust removal box 1 includes an inner filter cartridge 51 and an outer filter bag 57 disposed around the inner filter cartridge 51 to enclose a light dust storage area, and an intermittently open movable bottom plate 59 is installed at the bottom of the light dust storage area;

[0038] The outer filter bag 57 has a folded state in the axial direction;

[0039] The movable port 53 is fixedly provided at the end of the outer filter bag 57 and is driven to move in the vertical direction.

[0040] Specifically, it also includes an outlet connected to the purification chamber 13 for discharging purified gas. A side pipe 21 is fixedly connected to the first chamber 11. One port of the three-way valve 3 is connected to the air inlet pipe 2, and the other two ports are connected to the side pipe 21 and the second chamber 12, respectively. It also includes an air injection unit for pulsed air injection at the center of the filter bag assembly 5. The above structures are well known to those skilled in the art and will not be described in detail here.

[0041] The three-way valve 3 can be preset with a timer program that switches at a fixed time (e.g., a time period determined by actual circumstances, such as a day or a week), so that the exhaust gas in the air inlet pipe 2 is discharged into the first chamber 11 or the second chamber 12, and exhaust to the other chamber is stopped. The gas is purified only by the filter bag assembly 5 in the first chamber 11 or the second chamber 12 before being discharged through the purification chamber 13. Alternatively, based on the gas flow rate detection at the gas outlet, when the gas flow rate falls below a threshold, it indicates that the filter bag assembly 5 in the currently operating chamber is clogged with dust. Subsequently, the three-way valve 3 is controlled by the program to switch to the other chamber, where purification is performed through the unblocked filter bag assembly 5. Other system control methods known to those skilled in the art are also possible. This allows the two chambers to purify the exhaust gas in turn. When one chamber needs to clean the filter bag assembly 5 of dust, the other chamber is activated, reducing the time required to wait for the sedimentation to complete when there is only one chamber.

[0042] Furthermore, movable plates 15 are slidably provided in the first chamber 11 and the second chamber 12, respectively, and a driving unit 16 that moves in the vertical direction is provided in the dust removal box 1. The movable plate 15 and the driving unit 16 are fixedly welded, and a plurality of movable ports 53 are all engaged with the movable plate 15. A fixed partition 14 is fixedly provided in the dust removal box 1 to separate the purification chamber 13. The port of the inner filter cartridge 51 is engaged with the fixed partition 14, and the purified gas enters the purification chamber 13 through the inner filter cartridge 51. In the default state, the movable plate 15 is located at the highest point, that is, close to the port position of the inner filter cartridge 51. At this time, the outer filter bag 57 is unfolded in the axial direction and is sleeved on the outside of the inner filter cartridge 51. The bottom of the outer filter bag 57 is fixedly connected to the bottom of the inner filter cartridge 51, as shown in FIG. Figure 5 As shown. Since the filter holes of the outer filter bag 57 are larger than the filter holes of the inner filter cartridge 51, when the exhaust gas passes through the filter bag assembly 5, the heavy dust in it is intercepted outside the outer filter bag 57 due to its larger particles, while the light dust enters the outer filter bag 57 and is finally intercepted by the inner filter cartridge 51. At this time, the area between the outer filter bag 57 and the inner filter cartridge 51 becomes the light dust storage area, which separates the light and heavy dust.

[0043] When air intake into the chamber stops, the movable plate 15 is first driven downward in the vertical direction by a drive unit 16, such as a linear motor or an electric telescopic rod. This increases the distance between the movable plate 15 and the port of the inner filter cartridge 51, and the movable opening 53 of the outer filter bag 57 moves downward, causing the outer filter bag 57 to be squeezed in the axial direction and folded. The outer filter bag 57 can be configured to have an annular bellows structure, or a Z-shaped fold can be pre-set on the outer filter bag 57 to achieve folding. During the folding process, the dust in the light dust storage area is compressed by the inner wall of the outer filter bag 57, squeezing out the air between the light dust nuclei, shortening the distance between the dust nuclei and increasing their density. The pressure causes the light dust to agglomerate and form lumps. Simultaneously, during the folding process of the outer filter bag 57, heavy dust intercepted by the outer wall is shaken off and automatically settles.

[0044] The movable bottom plate 59 is symmetrically arranged at the bottom of the light dust storage area, and the movable bottom plate 59 is a semicircular ring structure rotatably arranged between the outer filter bag 57 and the inner filter cartridge 51. Figure 7 As shown. The two movable bottom plates 59 are hinged to each other. In the default state, the two movable bottom plates 59 form a right angle between them. To subsequently open the movable bottom plates 59, a drive motor can be provided. The output shaft of the drive motor can output torque to drive the movable bottom plates 59 to rotate, thereby opening the movable bottom plates 59. Alternatively, electromagnets that attract each other can be provided on the movable bottom plates 59. When the electromagnets are energized, the movable bottom plates 59 move closer together and open. At this point, the agglomerated light dust falls due to its own weight, along with the heavy dust outside the outer filter bag 57. This can effectively reduce the problem of light dust remaining floating.

[0045] Then, the movable plate 15 is driven to move upward and reset to a position close to the port of the inner filter cartridge 51 , and the outer filter bag 57 is restored to the expanded state while the movable bottom plate 59 is kept open.

[0046] Finally, the air is ejected through the air jet unit. Because the nozzle is located in the center of the filter bag assembly 5, i.e., at the axis of the inner filter cartridge 51, the ejected gas diffuses along the outer wall of the inner filter cartridge 51, weakening the impact of the airflow. This weakened airflow is then blocked by the inner wall of the outer filter bag 57, where it is guided by the inner wall to form a top-down flow direction, blowing the remaining dust in the light dust storage area downward and accelerating the settling of the light dust. After the air jet is completed, the movable bottom plate 59 is driven to close, returning to the default state.

[0047] In the above technology, the three-way valve 3 allows the two chambers to be cleaned alternately. When one chamber needs to clean the dust in the filter bag assembly 5, the other chamber is activated, reducing the time required to wait for the sedimentation to complete. The filter bag assembly 5 also separates light and heavy dust. The folding of the outer filter bag 57 shakes off the heavy dust and compresses the light dust, helping the light dust to agglomerate, reducing the amount of light dust floating in the chamber and increasing the dust settling rate.

[0048] As an embodiment further provided by the present invention, it also includes a folding assembly for supporting the outer filter bag 57, which includes a first folding rod 54 and a second folding rod 55 hinged to each other, and a sliding member 56 that slides along the outer wall of the inner filter cylinder 51 is provided at the connection position of each folding assembly.

[0049] Specifically, the first folding rod 54 and the second folding rod 55 form a group of folding components, which are rotatably connected to each other, and the slide 56 is rotatably provided at the connecting shaft of the first folding rod 54 and the second folding rod 55, that is, each group of folding components has a slide 56 above and below. The first folding rod 54 at the top is rotatably connected to the movable opening 53, and the second folding rod 55 at the bottom is rotatably connected to the bottom of the outer filter bag 57. Figure 5 and Figure 6 As shown. When the movable opening 53 moves downward from the default state, the slider 56 slides vertically on the outer wall of the inner filter cartridge 51, so that each group of folding components is constrained by the slider 56 and folds in the specified direction, and the angle between the first folding rod 54 and the second folding rod 55 decreases. The outer filter bag 57 is wrapped around the outer periphery of the folding component and folds as the angle between the first folding rod 54 and the second folding rod 55 decreases, as shown. Figure 6 shown.

[0050] A scraper 561 made of rubber is provided between the slides 56, and the scraper 561 is a hollow structure. The inner wall of the outer filter bag 57 is fixedly glued to the scraper 561, so that when the folding assembly is folded, the outer filter bag 57 is driven to fold and deform, and the outer filter bag 57 has pleats. When the folding assembly is folded, the outer filter bag 57 is radially expanded, but the existence of the pleats prevents the aperture of the filter from changing.

[0051] When the movable opening 53 moves downward, each folding assembly folds, causing the slider 56 to move downward. The slider 56 drives the scraper 561 down the outer wall of the inner filter cartridge 51, scraping it against the outer wall and removing the adsorbed light dust. Since the inner filter cartridge 51 is typically made of polyester fiber, the scraping between the inner filter cartridge 51 and the rubber scraper 561 generates static electricity. This static electricity causes the light dust to adhere more to the scraper 561, which then compresses the light dust and causes it to fall downward through the hollow structure.

[0052] Even if the light dust is scraped off and floats in the light dust storage area, it will be squeezed by the inner wall of the outer filter bag 57 due to the folding of the outer filter bag 57. At this time, the outer filter bag 57 blocks the larger filter holes due to the heavy dust adsorbed on the surface, preventing the light dust from floating out directly, thereby further improving the cleaning and agglomeration effect of the light dust.

[0053] As another embodiment further provided by the present invention, the first folding rod 54 and the second folding rod 55 form an acute angle structure obliquely downward when folded.

[0054] Specifically, the length of the second folding rod 55 is shorter than that of the first folding rod 54. When the movable opening 53 moves downward, the two ends of the folding assembly approach each other, and the angle between the first folding rod 54 and the second folding rod 55 decreases. Since the second folding rod 55 is shorter, the first folding rod 54 gradually swings from the outer circumference to the center of the circle. At this time, the angle between the first folding rod 54 and the second folding rod 55 is as follows: Figure 6 The status shown.

[0055] The tip of the angle points diagonally downward, and the angle serves as the boundary between the outer filter bag 57 and the upper side. The heavy dust on the upper side is automatically driven by the swing and rolls down along the inclined surface, while the heavy dust on the lower side swings with the second folding rod 55, and the swing angle is large, which can make the heavy dust on the lower side automatically roll down to the upper side of the next group. Some of the heavy dust that adheres to the filter does not roll down and is blocked in the filter holes. As the angle between the lower plate and the upper side decreases, this part of the heavy dust is squeezed and agglomerated. After the folding assembly is unfolded, the upper and lower sides swing again and shake off the heavy dust.

[0056] However, the above technical solution has a problem: during the exhaust process, the exhaust gas is at a high temperature, while the inside of the filter bag assembly 5 is connected to the outside air, which is relatively low in temperature and contains varying amounts of moisture depending on the humidity at the site. When the high-temperature exhaust gas first contacts the outer filter bag 57, the moisture contained within the outer filter bag 57 liquefies under the contact of the cold and hot air flows. Condensation forms on the inner wall of the outer filter bag 57, which absorbs light dust, causing it to stick inside the outer filter bag 57. This light dust is not scraped off by the scraper 561, causing the outer filter bag 57 to clog.

[0057] As an embodiment further provided by the present invention to solve the above-mentioned problem, a rotating wheel 563 is rotatably provided on the sliding member 56 and rotates as the folding assembly is unfolded.

[0058] Specifically, Figure 11 As shown for reference, ratchets 562 are fixed on both sides of the top of the second folding rod 55, and the bottom of the first folding rod 54 is rotatably arranged between the two ratchets 562. The slide 56 remains vertical and movable, and the ratchets 562 rotate relative to the slide 56. A plurality of elastic members 564 are fixedly arranged in a circumferential array on the rotating wheel 563. The elastic members 564 have a tip and an opposite tail end. When the folding assembly is folded, the elastic members 564 are arranged in a circumferential array. Figure 11The direction shown is for reference. At this time, the second folding rod 55 is swung upward relative to the slide 56, that is, it rotates clockwise, that is, the ratchet 562 rotates clockwise relative to the slide 56. At this time, the ratchet teeth of the ratchet 562 are oriented in the same direction as the tip of the elastic member 564. The ratchet teeth are weakly blocked by the elastic member 564, and the ratchet 562 will not drive the rotating wheel 563 to rotate. When the folding assembly is folded, the rotating wheel 563 does not move, avoiding knocking on the heavy dust on the outer filter bag 57, so that part of the heavy dust stays on the outer filter bag 57 to block the filter holes, preventing light dust from floating out.

[0059] When the folding assembly is unfolded, the second folding rod 55 swings downward relative to the slide 56 and rotates counterclockwise. At this time, the ratchet 562 rotates counterclockwise, and the ratchet teeth abut against the tip of the elastic member 564, so that the tail end of the elastic member 564 is under pressure and swings. The tail ends of multiple elastic members 564 extend out of the rotating wheel 563, and when the ratchet 562 rotates, it pushes the elastic member 564 to drive the rotating wheel 563 to rotate. The rotating wheel 563 and the tail end of the extended elastic member 564 rotate and abut against the inner wall of the outer filter bag 57. The tail end knocks and vibrates the inner wall of the outer filter bag 57 multiple times, which promotes the light dust adhering to the inner wall to fall off.

[0060] As another embodiment further provided by the present invention, it also includes keels 521 arranged in a circumferential array on the inner filter cartridge 51.

[0061] Specifically, the keel 521 is provided with a rectangular opening, through which the inner filter cartridge 51 is inserted into the keel 521 and supported by the keel 521 to be shaped, so that the inner filter cartridge 51 can be a hard filter material or a soft bag. Figure 7 and Figure 8 As shown in the structure, a fixed opening 52 is provided at the top of the keel 521 . In the default state, the movable opening 53 is close to the port of the inner filter cartridge 51 and is closely attached to the bottom side of the fixed opening 52 .

[0062] As another embodiment further provided by the present invention, the present invention further includes a rotating member 584 that is rotatably arranged relative to the inner filter cartridge 51 and forms a blocking fit with the movable opening 53 , and the rotating member 584 and the movable bottom plate 59 maintain synchronous movement.

[0063] Specifically, it also includes a support frame 58 provided in the keel 521, and the support frame 58 is located between the outer filter bag 57 and the inner filter cartridge 51. The rotating member 584 is rotatably provided on the support frame 58, and the rotating member 584 is symmetrically and fixedly provided with a slide rail 586 about the center of the rotating axis. Figure 7 The two movable bottom plates 59 are fixed with protrusions, and further include movable rods 591 slidably arranged on both sides of the support frame 58 , wherein the bottom ends of the movable rods 591 move in the protrusions, and the top ends of the movable rods 591 are slidably arranged in the slide rails 586 .

[0064] A second spring 585 is provided on the rotating member 584 to maintain a fixed angle. When the movable opening 53 moves downward, the movable opening 53 pushes downward against the rotating member 584, causing the rotating member 584 to rotate clockwise until it is offset from the movable opening 53. The rotating member 584 then moves above the movable opening 53 and does not interfere with the movable opening 53's downward movement. At this time, the upward swing of the slide rail 586 is relatively small, causing the top of the movable rod 591 to move slightly upward. As a result, the bottom of the movable rod 591 does not pull the raised block upward to a much greater extent, and the movable bottom plate 59 remains closed. When the movable opening 53 moves upward, it will push the rotating member 584 upward, causing the rotating member 584 to rotate counterclockwise and drive the slide rail 586 to rotate counterclockwise. The slide rail 586 pushes the top of the movable rod 591 to move downward, causing the bottom end of the movable rod 591 to move downward a distance and then push the movable bottom plate 59. During the pushing process, the bottom end of the movable rod 591 is always in the raised block, so that the movable bottom plate 59 is open.

[0065] After the movable opening 53 moves upward for a period of time, it is offset from the rotating member 584. The rotating member 584 is pulled back to a fixed angle by the second spring 585. The slide rail 586 swings clockwise and pulls the movable bottom plate 59 through the movable rod 591, so that the movable bottom plate 59 is closed again.

[0066] As another embodiment further provided by the present invention, it also includes a hook portion 583, on which a first spring 581 is provided for maintaining a predetermined height, and the rotating member 584 has a station in its movable stroke for engaging with the hook portion 583.

[0067] Specifically, the hook portion 583 is slidably arranged on the support frame 58. The hook portion 583 has an inclined surface, and a cylinder corresponding to the hook portion 583 is fixedly arranged inside the rotating member 584. When the movable opening 53 moves upward, it will push the rotating member 584 upward, causing the rotating member 584 to rotate counterclockwise and drive the cylinder to rotate counterclockwise to the inclined surface. The cylinder squeezes the inclined surface to make the hook portion 583 move downward, and the first spring 581 is squeezed and accumulates force. After the cylinder is separated from the inclined surface, the cylinder falls into the hook portion 583. At this time, the stored force of the first spring 581 is released and drives the hook portion 583 to clamp the rotating member 584, and pushes the top end of the movable rod 591 downward through the slide rail 586, so that the bottom end of the movable rod 591 moves downward for a distance and then pushes the movable bottom plate 59, so that the movable bottom plate 59 remains open.

[0068] As another embodiment further provided by the present invention, it further includes a transmission rod 582 slidably arranged along the vertical direction, and a hook portion 583 is fixedly arranged at the end of the transmission rod 582.

[0069] Specifically, it also includes an inclined block 587 that slides radially along the port of the inner filter cartridge 51, which is used to clamp the movable port 53. The inclined block 587 and the transmission rod 582 keep synchronous movement. The transmission rod 582 is slidably set on the support frame 58, and the inclined block 587 is slidably matched with the first end of the transmission rod 582. Figure 10 As shown, a locking groove 531 is provided on the movable opening 53 , and an inclined guiding surface exists between the top surface of the movable opening 53 and the locking groove 531 .

[0070] During the upward movement of the movable port 53, the guide surface first contacts the inclined block 587. Pushed by the guide surface, the inclined block 587 radially approaches the axis of the port of the inner filter cartridge 51, causing the inclined block 587 to squeeze the first end of the transmission rod 582. The transmission rod 582 slides downward, causing the hook portion 583 at the second end to move downward synchronously, compressing the first spring 581. Furthermore, the hook portion 583 is offset from the cylinder on the rotating member 584. After the rotating member 584 disengages from the hook portion 583, it rotates clockwise under the pull of the second spring 585, and pulls the movable bottom plate 59 via the movable rod 591, causing the movable bottom plate 59 to resume its closed state.

[0071] At the same time, the inclined block 587 slides into the card slot 531 along the guide surface. After losing the obstruction of the guide surface, the elastic potential energy of the first spring 581 is released and drives the transmission rod 582 to move upward. The transmission rod 582 pushes the inclined block 587 and the card slot 531 to engage with each other, so that the position of the movable opening 53 is locked in a state close to the fixed opening 52. At this time, a large force is required to move the movable opening 53 downward to disengage the inclined block 587 from the card slot 531.

[0072] Working principle: The three-way valve 3 uses a preset program to discharge the exhaust gas in the air inlet pipe 2 to the first chamber 11 or the second chamber 12, and stops exhausting the other chamber. When one of the chambers needs to clean the dust in the filter bag assembly 5, the other chamber is started.

[0073] In the default state, the movable plate 15 is located at the highest point, that is, close to the port position of the inner filter cartridge 51. At this time, the outer filter bag 57 is expanded in the axial direction and is sleeved on the outside of the inner filter cartridge 51. The bottom of the outer filter bag 57 is fixedly connected to the bottom of the inner filter cartridge 51. Figure 5 As shown. Since the filter holes of the outer filter bag 57 are larger than the filter holes of the inner filter cartridge 51, when the exhaust gas passes through the filter bag assembly 5, the heavy dust in it is intercepted outside the outer filter bag 57 due to its larger particles, while the light dust enters the outer filter bag 57 and is finally intercepted by the inner filter cartridge 51. At this time, the area between the outer filter bag 57 and the inner filter cartridge 51 becomes the light dust storage area, which separates the light and heavy dust.

[0074] When air intake in the chamber stops, the movable plate 15 is first driven downward in the vertical direction by the driving unit 16 such as a linear motor or an electric telescopic rod, the distance between the movable plate 15 and the port of the inner filter cartridge 51 increases, and the movable port 53 of the outer filter bag 57 moves downward.

[0075] When the movable opening 53 moves downward from the default state, the angle between the first folding rod 54 and the second folding rod 55 decreases, and the angle between the first folding rod 54 and the second folding rod 55 becomes as follows: Figure 6 In the state shown, the heavy dust on the upper side automatically rolls down along the inclined surface due to the swinging, while the heavy dust on the lower side swings with the second folding rod 55, and the swinging angle is large, which can make the heavy dust on the lower side automatically roll down to the upper side of the next group.

[0076] Each folding assembly folds, causing the slider 56 to move downward. The slider 56 drives the scraper 561 down the outer wall of the inner filter cartridge 51, scraping it and removing the adsorbed light dust. During the folding process, the dust in the light dust storage area is compressed by the inner wall of the outer filter bag 57, squeezing out the air between the light dust nuclei, shortening the distance between the dust nuclei and increasing their density. This pressure causes the light dust to agglomerate and form lumps.

[0077] The movable opening 53 pushes downward against the rotating member 584, causing it to rotate clockwise until it is offset from the movable opening 53. The rotating member 584 then moves above the movable opening 53 and does not interfere with the downward movement of the movable opening 53. At this point, the upward swing of the slide rail 586 is relatively small, causing the top of the movable rod 591 to move slightly upward, and the movable bottom plate 59 remains closed. When the movable opening 53 moves upward further, it pushes upward against the rotating member 584, causing it to rotate counterclockwise and driving the slide rail 586 to rotate counterclockwise. The slide rail 586 pushes the top of the movable rod 591 downward, causing the bottom of the movable rod 591 to move downward a distance before pushing against the movable bottom plate 59. During this pushing process, the bottom of the movable rod 591 remains within the raised block, causing the movable bottom plate 59 to open.

[0078] At the same time, the rotating member 584 rotates counterclockwise, driving the cylinder to rotate counterclockwise to the inclined surface. The cylinder presses the inclined surface, causing the hook 583 to move downward, compressing the first spring 581 and accumulating force. After the cylinder leaves the inclined surface, it falls into the hook 583. At this time, the accumulated force of the first spring 581 is released, driving the hook 583 to clamp the rotating member 584, so that the movable bottom plate 59 remains open.

[0079] At this time, the agglomerated light dust falls due to its own weight, and falls together with the heavy dust outside the outer filter bag 57, which can effectively reduce the problem of light dust continuing to float.

[0080] During the upward movement of the movable port 53, the guiding surface first contacts the inclined block 587. The inclined block 587 is pushed radially toward the axis of the port of the inner filter cartridge 51 by the guiding surface, so that the inclined block 587 squeezes the first end of the transmission rod 582. The transmission rod 582 slides downward and causes the hook portion 583 at the second end to move downward synchronously, so that the hook portion 583 is staggered with the cylinder on the rotating member 584, and the movable bottom plate 59 is lifted by the movable rod 591, so that the movable bottom plate 59 is restored to be closed.

[0081] Finally, the air is ejected through the air jet unit. Because the nozzle is located in the center of the filter bag assembly 5, i.e., at the axis of the inner filter cartridge 51, the ejected gas diffuses along the outer wall of the inner filter cartridge 51, weakening the impact of the airflow. This weakened airflow is then blocked by the inner wall of the outer filter bag 57, where it is guided by the inner wall to form a top-down flow direction, blowing the remaining dust in the light dust storage area downward and accelerating the settling of the light dust. After the air jet is completed, the movable bottom plate 59 is driven to close, returning to the default state.

[0082] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A device for treating exhaust gas after a catalytic oxidation reaction of nitrogen oxides, comprising a dust removal box (1) and a purification chamber (13), characterized in that: It also includes a first chamber (11) and a second chamber (12) which are opened in the dust removal box (1) and separated from each other, and an air inlet pipe (2) for alternately supplying air to the first chamber (11) and the second chamber (12), and a three-way valve (3) which is switched under program control is provided on the air inlet pipe; A filter bag assembly (5) is provided in the dust removal box (1), comprising an inner filter cartridge (51) and an outer filter bag (57) arranged around the inner filter cartridge (51) to enclose a light dust storage area, and an intermittently open movable bottom plate (59) is installed at the bottom of the light dust storage area; The outer filter bag (57) has a folded state in an axial radial direction; A movable port (53) fixedly arranged at the end of the outer filter bag (57) is driven to move in a vertical direction; It also includes a folding assembly for supporting the outer filter bag (57), which includes a first folding rod (54) and a second folding rod (55) hinged to each other, and a sliding member (56) is provided at the connection position of each folding assembly to slide along the outer wall of the inner filter cartridge (51); It also includes a rotating member (584) that is rotatably arranged relative to the inner filter cartridge (51) and forms a blocking fit with the movable opening (53), and the rotating member (584) and the movable bottom plate (59) maintain synchronous movement; It also includes a hook-shaped portion (583) on which a first spring (581) for maintaining a predetermined height is provided, and the rotating member (584) has a station in its movable stroke for engaging with the hook-shaped portion (583).

2. The exhaust gas treatment device after the catalytic oxidation reaction of nitrogen oxides according to claim 1 is characterized in that: The first folding rod (54) and the second folding rod (55) form an acute angle structure obliquely pointing downwards when in the folded state.

3. The exhaust gas treatment device after catalytic oxidation reaction of nitrogen oxides according to claim 1, characterized in that: The sliding member (56) is rotatably provided with a rotating wheel (563) that rotates as the folding assembly unfolds.

4. The exhaust gas treatment device after catalytic oxidation reaction of nitrogen oxides according to claim 1, characterized in that: It also includes keels (521) arranged in a circumferential array on the inner filter cartridge (51).

5. The exhaust gas treatment device after catalytic oxidation reaction of nitrogen oxides according to claim 1, characterized in that: It also includes a transmission rod (582) slidably arranged in a vertical direction, and the hook-shaped portion (583) is fixedly arranged at the end of the transmission rod (582).

6. The exhaust gas treatment device after catalytic oxidation reaction of nitrogen oxides according to claim 5, characterized in that: It also includes an inclined block (587) that slides radially along the port of the inner filter cartridge (51) and is used to engage the movable port (53).

7. The exhaust gas treatment device after catalytic oxidation reaction of nitrogen oxides according to claim 6, characterized in that: The inclined block (587) and the transmission rod (582) maintain synchronous movement.

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