Flue gas denitration and dust removal treatment device for casting smelting furnace

Abstract

The application discloses a casting smelting furnace flue gas denitration and dust removal treatment device, relates to the technical field of flue gas denitration and dust removal appliances, and comprises a purification tower installed on a placing area, a dust removal pipe is connected and installed at the lower end of the purification tower, a gas outlet cylinder is connected and installed at the upper end of the purification tower, external supports are welded on the top and the side end outer wall of the purification tower, a dust falling part, a spraying part and a gas washing part are sequentially installed in the purification tower from bottom to top, a liquid return filtering assembly is installed between the spraying part and the gas washing part, the gas washing part comprises a gas washing cylinder fixedly installed on the inner wall upper end of the purification tower and a separation frame installed in the gas washing cylinder, and a gas washing adjusting assembly for adjusting the gas retention degree barrier is installed in the separation frame; through the liquid return filtering assembly, the circulation filtering of the gas washing liquid is realized, and through the gas washing adjusting assembly, the adjustment of the flue gas gas retention degree is realized.

Description

Technical Field

[0001] This invention relates to the technical field of flue gas denitrification and dust removal equipment, and in particular to a flue gas denitrification and dust removal treatment device for foundry and smelting furnaces. Background Technology

[0002] The flue gas denitrification and dust removal treatment device for foundry smelting furnaces is an important environmental protection equipment in the foundry production process. It is mainly used to remove dust, denitrify, and purify harmful gases from the high-temperature flue gas generated during the operation of the smelting furnace. It is widely used in flue gas treatment fields such as foundry workshops and metal smelting production lines. The existing flue gas denitrification and dust removal treatment device for foundry smelting furnaces mainly consists of a purification tower, a dust removal structure, a spray structure, a gas washing structure, and a circulating liquid supply system. It relies on the contact reaction between the flue gas and the spray liquid and gas washing liquid to absorb and treat pollutants such as dust particles and nitrogen oxides in the flue gas.

[0003] Its working method is as follows: After the high-temperature flue gas generated by the casting and smelting furnace enters the purification tower, it first passes through the dust removal structure to initially separate the large particles of dust in the flue gas. Then it enters the spray area, where the spray liquid contacts the flue gas to absorb some of the dust and harmful components. Then it enters the gas washing area, where the gas washing liquid further purifies the flue gas. The cleaned flue gas is then discharged through the exhaust structure.

[0004] In existing flue gas denitrification and dust removal treatment devices for foundry smelting furnaces, the flow path and residence time of flue gas after entering the scrubbing zone are usually fixed during actual operation. There is a lack of a structure to adjust the degree of flue gas retention based on the flue gas flow rate and treatment status. When the flue gas velocity is high, the flue gas easily passes through the scrubbing zone quickly, resulting in insufficient contact time between the flue gas and the scrubbing liquid. This leads to insufficient reaction and absorption of nitrogen oxides and other harmful components in the flue gas, reducing the denitrification and dust removal effect. Simultaneously, the recycled reaction liquid easily carries incompletely filtered impurities, affecting the stable operation of the spray structure and further reducing flue gas treatment efficiency. Therefore, this application designs a flue gas denitrification and dust removal treatment device for foundry smelting furnaces to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a denitrification and dust removal device for casting and smelting furnace flue gas.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a flue gas denitrification and dust removal treatment device for casting and smelting furnaces, comprising a purification tower installed in the placement area, a dust discharge pipe connected to the lower end of the purification tower, an air outlet pipe connected to the upper end of the purification tower, external supports welded to the top and side outer walls of the purification tower, and a dust settling section, a spray section, and a gas washing section installed sequentially from bottom to top inside the purification tower, with a liquid return filter assembly installed between the spray section and the gas washing section, and the gas washing section comprising a gas washing cylinder fixedly installed on the upper end of the inner wall of the purification tower and a partition frame installed in the gas washing cylinder, with a gas washing adjustment assembly installed in the partition frame for adjusting the degree of gas retention.

[0007] Preferably, the air washing regulating component includes multiple air supply columns spaced apart at the bottom of the air washing cylinder and a sleeve rod slidably mounted on the air supply columns. Multiple first connecting holes are spaced apart on the air supply columns, and multiple second connecting holes are spaced apart on the sleeve rod. The two sides of the first connecting holes and the second connecting holes are respectively connected to the spray section and the air washing section.

[0008] Preferably, an air-retaining top plate is fixedly installed at the top of the sleeve rod, and multiple air-retaining stacked plates are installed at the lower end of the air-retaining top plate. Both the air-retaining top plate and the air-retaining stacked plates are corrosion-resistant porous materials, and the air-retaining top plate is placed on the partition frame.

[0009] Preferably, multiple spaced ropes are installed and connected between the air-retaining top plate and the multiple air-retaining stacked plates, and both the air-retaining top plate and the multiple air-retaining stacked plates are counterweight adjustment plates adapted to air pressure pushing design.

[0010] Preferably, the spray section includes a central spray packing installed in the purification tower, a plurality of connecting columns equidistantly installed on the lower end face of the air scrubbing cylinder, and a collection cylinder installed below the spray packing. Spray heads are installed at the bottom ends of the connecting columns, and a pressure supply plate for transmitting pressure to the spray heads is provided on the lower end face of the air scrubbing cylinder.

[0011] Preferably, a reflux guide plate is installed on the inner wall of the purification tower between the collection cylinder and the spray packing, and multiple connecting columns for connecting the dust settling section and the spray section are installed at intervals on the collection cylinder. A baffle cap is installed on the connecting column, and a connecting groove is opened on the connecting column.

[0012] Preferably, each of the connecting columns is provided with a connecting through hole for the spray head to connect to the upper end of the air washing section, and a filter baffle is installed at the top of the connecting through hole.

[0013] Preferably, each of the filter baffles is rotatably mounted with a rotating impeller, and the rotating impeller is provided with blades at intervals for stirring the reaction liquid in the gas washing section, and the lower end of the blades is provided with scraping blades for extending into the filter holes of the filter baffle.

[0014] Preferably, the return liquid filtration assembly includes a suction circulation box installed at the top of the purification tower. Two liquid return pipes are installed at the lower end of the suction circulation box, and a liquid collection seat is installed at the bottom end of each liquid return pipe. A filter outlet pipe located above the air washing cylinder is installed at the side end of the suction circulation box. The bottom ends of the two liquid return pipes are respectively located on the upper wall of the air washing cylinder and the collection cylinder.

[0015] Preferably, the dust removal section includes an interlaced baffle dust collector plate installed on the side end of the air inlet pipe of the purification tower and a flow equalization guide plate installed on the interlaced baffle dust collector plate, wherein the interlaced baffle dust collector plate is located at the upper end of the dust discharge pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. In this invention, the combination of the gas washing cylinder, the partition frame, and the gas washing adjustment component, along with the gas delivery column, the sleeve rod, and the first and second connecting holes to form an adjustable communication structure, allows for adjustment of the flow obstruction of the flue gas through the gas washing section according to the flue gas flow state. Combined with the gas retention top plate, gas retention stack, spacer rope, and counterweight adjustment plate to form a multi-stage gas retention structure, this effectively extends the residence time of the flue gas in the gas washing area, improves the contact reaction efficiency between the flue gas and the reaction liquid, thereby achieving sufficient gas washing and good denitrification and dust removal effects. Furthermore, the combination of the spray section and the return liquid filtration component allows the gas washing liquid to be recycled and filtered before re-participating in the spray, reducing the impurity content in the circulating liquid, improving the utilization efficiency of the circulating liquid, and thus achieving stable recycling and high flue gas purification efficiency.

[0018] 2. In this invention, the coordinated use of the spray packing, connecting column, spray head, and pressure supply plate enables the spray head to stably absorb the reaction liquid and spray it evenly, increasing the contact area between the flue gas and the spray liquid. Combined with the return guide plate, connecting column, baffle cap, and connecting groove, a liquid return structure is formed, achieving continuous recycling of the spray liquid and reducing reaction liquid waste. This results in uniform spraying and high liquid recovery efficiency. Through the coordination of the filter baffle, rotating impeller, blades, and scraper, the reaction liquid is continuously agitated by the blades while being filtered, and the scraper made of fine steel wire extends into the filter holes of the filter baffle to scrape, effectively preventing filter clogging, reducing the risk of spray head blockage, and ensuring... The system ensures continuous and stable operation, achieving excellent filtration, strong self-cleaning ability, and reliable spraying. Through the combined use of a suction circulation box, liquid return pipe, liquid collection seat, filter outlet pipe, and replaceable filter, the reaction liquid in the gas washing cylinder and collection cylinder is continuously suctioned, filtered, and circulated. The filter can be replaced periodically according to usage, further reducing the impurity content in the circulating liquid, ensuring the cleanliness of the spray liquid, and extending the service life of the spray unit. This results in high circulating filtration efficiency, convenient maintenance, and stable and durable operation. Ultimately, it solves the problem of insufficient adjustment capability of the contact residence time between flue gas and gas washing liquid in existing foundry smelting furnace flue gas treatment processes. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0021] Figure 2 This is a cross-sectional perspective view of the purification tower of the present invention.

[0022] Figure 3 This is a schematic diagram of the three-dimensional structure of the spray filler of the present invention;

[0023] Figure 4 This is a three-dimensional structural diagram of the recirculation guide plate of the present invention;

[0024] Figure 5 This is a schematic diagram of the three-dimensional structure of the cap of the present invention;

[0025] Figure 6 This is a schematic diagram of the three-dimensional structure of the connecting groove of the present invention;

[0026] Figure 7 This is a schematic diagram of the three-dimensional structure of the flow guide plate of the present invention;

[0027] Figure 8This is a schematic diagram of the three-dimensional structure of the partition frame of the present invention;

[0028] Figure 9 This is a three-dimensional structural diagram of the spray head of the present invention;

[0029] Figure 10 This is a schematic diagram of the three-dimensional structure of the air-retaining stack plate of the present invention;

[0030] Figure 11 This is a three-dimensional structural diagram of the filter baffle of the present invention;

[0031] Figure 12 This is a three-dimensional structural diagram of the rotating impeller of the present invention;

[0032] Figure 13 This is a schematic diagram of the three-dimensional structure of the sleeve rod of the present invention.

[0033] The following are the components listed in the diagram: 1. Purification tower; 2. Dust discharge pipe; 3. External support frame; 4. Air outlet; 5. Interlaced baffle dust collector; 6. Collection cylinder; 7. Air washing cylinder; 8. Suction circulation box; 9. Spray packing; 10. Return guide plate; 11. Flow equalization guide plate; 12. Connecting column; 13. Baffle cap; 14. Connecting groove; 15. Liquid return pipe; 16. Filter liquid outlet pipe; 17. Separating frame; 18. Air retention top plate; 19. Connecting column; 20. Spray head; 21. Pressure supply connecting plate; 22. Air delivery column; 23. Air retention stack plate; 24. Spacing rope; 25. Filter baffle; 26. Rotating impeller; 27. Blade; 28. Scraper; 29. ​​First connecting hole; 30. Sleeve rod; 31. Second connecting hole; 32. Liquid intake seat. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] Example 1: See Figures 1 to 13The casting and smelting furnace flue gas denitrification and dust removal treatment device of the present invention includes a purification tower 1 installed in the placement area. A dust discharge pipe 2 is connected to the lower end of the purification tower 1, and an air outlet 4 is connected to the upper end of the purification tower 1. External supports 3 are welded to the top and side outer walls of the purification tower 1. Inside the purification tower 1, from bottom to top, a dust settling section, a spray section, and a gas washing section are installed sequentially. A return liquid filter assembly is installed between the spray section and the gas washing section. The gas washing section includes a gas washing cylinder 7 fixedly installed on the upper end of the inner wall of the purification tower 1 and a partition frame 17 installed in the gas washing cylinder 7. A gas washing adjustment assembly for adjusting the degree of gas retention is installed in the partition frame 17. The return liquid filtration assembly realizes the circulation filtration of the washing liquid. By setting the washing gas adjustment assembly, the degree of flue gas retention can be adjusted. The washing gas adjustment assembly includes multiple air supply columns 22 spaced apart at the bottom of the washing cylinder 7 and sleeve rods 30 slidably mounted on the air supply columns 22. Multiple first connecting holes 29 are spaced apart on the air supply columns 22, and multiple second connecting holes 31 are spaced apart on the sleeve rods 30. The two sides of the first connecting holes 29 and the second connecting holes 31 are respectively connected to the spray section and the washing section. By sliding the sleeve rods 30 along the air supply columns 22, the first connecting holes 29 and the second connecting holes 31 are connected to different degrees, thereby realizing the adjustment of the flue gas flow state.

[0036] Example 2: The technical solution is basically the same as that of Example 1, except that, as Figures 8 to 11 As shown, a gas-retaining top plate 18 is fixedly installed at the top of the sleeve rod 30, and multiple gas-retaining stacked plates 23 are installed at the lower end of the gas-retaining top plate 18. Both the gas-retaining top plate 18 and the gas-retaining stacked plates 23 are made of corrosion-resistant porous materials. The gas-retaining top plate 18 is placed on the partition frame 17. A multi-stage gas-retaining structure is formed by the gas-retaining top plate 18 and the gas-retaining stacked plates 23 to increase the contact time between the flue gas and the reaction liquid. Multiple spacer ropes 24 are installed and connected between the gas-retaining top plate 18 and the multiple gas-retaining stacked plates 23. Both the gas-retaining top plate 18 and the multiple gas-retaining stacked plates 23 are counterweight adjustment plates adapted to the air pressure pushing design. 4. The relative position of the gas retention stack 23 is restricted, and the gas retention state is adjusted by the counterweight adjustment plate in conjunction with the air pressure. The spray section includes a central spray packing 9 installed in the purification tower 1, multiple connecting columns 19 equidistantly installed on the lower end face of the gas washing cylinder 7, and a collection cylinder 6 installed below the spray packing 9. Spray heads 20 are installed at the bottom of each connecting column 19. A pressure supply connecting plate 21 for transmitting pressure to the spray heads 20 is arranged on the lower end face of the gas washing cylinder 7. The pressure supply connecting plate 21 has a liquid supply channel inside. Pressure is transmitted to the spray heads 20 through the pressure supply connecting plate 21, so that the spray heads 20 can perform spraying operations.

[0037] Example 3: The technical solution is basically the same as that of Example 1, except that, as Figures 6 to 13As shown, a reflux guide plate 10 is installed on the inner wall of the purification tower 1 between the collection cylinder 6 and the spray packing 9. Multiple connecting columns 12 for connecting the dust settling section and the spray section are installed at intervals on the collection cylinder 6. A baffle cap 13 is installed on each connecting column 12, and a connecting groove 14 is provided on each connecting column 12. The reflux guide plate 10 guides the liquid backflow, and the connecting columns 12 and the connecting groove 14 achieve liquid communication between the dust settling section and the spray section. Each connecting column 19 has a connecting through hole for the spray head 20 to connect to the upper end of the gas washing section. A filter baffle 25 is installed at the top of the connecting through hole. The filter baffle 25 filters the absorbed reaction liquid. To reduce the entry of impurities into the spray head 20, a rotating impeller 26 is rotatably mounted in the middle of each filter baffle 25. The rotating impeller 26 is spaced with blades 27 for agitating the reaction liquid in the gas washing section. The lower end of each blade 27 is spaced with scrapers 28 for extending into the filter holes of the filter baffle 25. The reaction liquid is agitated by the blades 27, and the scrapers 28 scrape the filter holes, reducing clogging of the filter holes. The scrapers 28 are made of multiple bundles of corrosion-resistant fine steel wire, and their lower ends can extend into the filter holes of the filter baffle 25. Driven by the rotating impeller 26, they scrape the inner wall of the filter holes to remove adhering impurities and keep the filter holes clear.

[0038] Example 4: The technical solution is basically the same as that of Example 1, except that, as Figures 1 to 5 ,like Figures 7 to 11 As shown, the liquid return filtration assembly includes a suction circulation box 8 installed at the top of the purification tower 1. Two liquid return pipes 15 are installed at the lower end of the suction circulation box 8, and each liquid return pipe 15 has a liquid receiving seat 32 installed at its bottom end. A filter outlet pipe 16 located above the air scrubbing cylinder 7 is installed on the side end of the suction circulation box 8. The two liquid return pipes 15 pass through the upper walls of the air scrubbing cylinder 7 and the collection cylinder 6 respectively, and the liquid receiving ends of the two liquid return pipes 15 extend downwards to below the set minimum liquid level of the air scrubbing cylinder 7 and the collection cylinder 6 respectively. The liquid receiving seat 32 is installed on the corresponding liquid receiving end. Liquid is drawn by the suction circulation box 8 in conjunction with the liquid return pipes 15, filtered, and then returned by the filter outlet pipe 16. The dust settling section includes components installed in the purification tower... The staggered baffle dust collector 5 at the side end of the air inlet pipe and the uniform flow guide plate 11 installed on the staggered baffle dust collector 5 are located at the upper end of the dust discharge pipe 2. The staggered baffle dust collector 5 deflects and reduces dust in the flue gas, and the uniform flow guide plate 11 guides the flue gas. The suction circulation box 8 adopts the existing circulating filter pump structure. It is equipped with a replaceable filter for filtering impurities in the washing liquid. The replaceable filter is installed in the circulation channel between the liquid return pipe 15 and the filter outlet pipe 16 to facilitate the filtration of the suction return reaction liquid. The filter can be disassembled and replaced periodically according to the usage to ensure the filtration effect of the circulating liquid and reduce the possibility of clogging of the spray head 20.

[0039] Working principle: In this embodiment, the present invention also proposes a method for using the denitrification and dust removal treatment device for casting and smelting furnace flue gas, including the following steps:

[0040] Step 1: First, install and fix the purification tower 1 in the placement area using the external support 3, and connect the lower end of the purification tower 1 to the flue gas output end of the casting and smelting furnace. Connect the gas outlet 4 to the subsequent discharge pipeline. Add an appropriate amount of gas washing reaction liquid to the gas washing cylinder 7 and the collection cylinder 6 to bring the spray section and gas washing section to the normal working liquid level. Then, check the installation status of the spray packing 9, the gas retention top plate 18, the gas retention stack 23 and the filter baffle 25. Install a replaceable filter in the suction circulation box 8, connect the suction circulation box 8 and the pressure supply system, so that the pressure supply connecting plate 21 can transmit pressure to each spray head 20. The suction circulation box 8 forms a circulating filtration loop, completing the preparation work before the operation of the device.

[0041] Step two: During operation, the flue gas generated by the casting and smelting furnace enters from the lower part of the purification tower 1. It first passes through the dust settling section formed by the staggered baffle dust collector 5 and the uniform flow guide plate 11. During multiple baffles and flow guides, large dust particles gradually settle to the bottom of the purification tower 1 and are discharged through the dust discharge pipe 2. Simultaneously, the uniform flow guide plate 11 guides the flue gas, ensuring it enters the spray section evenly. The pressure supply plate 21 continuously provides spray pressure to each spray head 20, and each spray head 20 draws the reaction liquid from the gas washing section through the connecting holes provided in the connecting column 19. Before entering the connecting through-hole, the reaction liquid is first filtered by the filter baffle 25 to prevent particulate impurities from entering the spray head 20. The filtered reaction liquid is then transported to the spray head 20 via the connecting column 19 and sprayed into the area of ​​the middle spray packing 9. When the flue gas passes through the middle spray packing 9, it comes into full contact with the atomized reaction liquid, thereby achieving the spray absorption of dust and harmful gases in the flue gas. The sprayed reaction liquid is guided to the collection cylinder 6 along the return guide plate 10. At the same time, the liquid in the dust settling section flows into the collection cylinder 6 via the connecting column 12 and the connecting groove 14, thereby achieving the recycling of the spray liquid.

[0042] Step 3: After the spraying treatment, the flue gas continues to enter the gas washing section. The flue gas first passes through the flow channel formed by the gas delivery column 22 and the sleeve rod 30. By adjusting the position of the sleeve rod 30 along the gas delivery column 22, the first connecting hole 29 and the second connecting hole 31 are connected to different degrees, thereby changing the degree of flue gas flow obstruction and adjusting the flow speed of the flue gas after entering the gas washing section. The flue gas then passes through the multi-stage gas retention area formed by the gas retention top plate 18 and multiple gas retention stacks 23 in sequence. Under the action of flue gas pressure, the gas retention top plate 18 and the gas retention stacks 23 act as counterweight adjustment plates and work with the interval rope 24 to produce corresponding position changes, so that the flue gas forms different degrees of gas retention effect in the gas washing area, prolonging the contact time between the flue gas and the reaction liquid and improving the flue gas washing treatment effect.

[0043] Step four: During the continuous extraction of reaction liquid by the spray head 20, the reaction liquid first passes through the filter baffle 25 for filtration. The filter baffle 25 can intercept particulate impurities in the reaction liquid, reducing the possibility of impurities entering the spray head 20 and causing blockage. As the reaction liquid flows, the rotating impeller 26 rotates continuously under the action of the liquid flow, driving the blade 27 to rotate synchronously, stirring the reaction liquid near the filter baffle 25 and preventing particulate impurities from depositing on the surface of the filter baffle 25. At the same time, the scraper 28 set at the lower end of the blade 27 rotates synchronously with the rotating impeller 26 and extends into the inner wall of the filter hole of the filter baffle 25 to scrape and remove impurities attached to the inner wall of the filter hole in time, reducing the possibility of blockage of the filter baffle 25 and keeping the filter baffle 25 in good filtration condition. This ensures that the reaction liquid can stably enter the connecting through hole and be transported to the spray head 20 for continuous spraying through the connecting column 19, improving the stability of the spray system operation.

[0044] Step 5: The suction circulation box 8 continuously draws the reaction liquid from the gas washing cylinder 7 and the collection cylinder 6 through the two liquid return pipes 15. After entering the suction circulation box 8, the reaction liquid is filtered by the internal filtration structure and then transported back to the gas washing cylinder 7 for recycling through the filtration outlet pipe 16 to ensure a stable liquid level and cleanliness of the reaction liquid in the gas washing section. After the continuous synergistic action of the dust settling section, spray section, gas washing section and return liquid filtration assembly, the dust and harmful gases in the flue gas are fully purified. Finally, the purified flue gas is discharged through the outlet pipe 4, and the settled impurities are discharged through the dust discharge pipe 2, realizing flue gas denitrification and dust removal and the recycling of the reaction liquid.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flue gas denitrification and dust removal treatment device for casting and smelting furnaces, comprising a purification tower (1) installed in a placement area, a dust discharge pipe (2) connected to the lower end of the purification tower (1), an air outlet pipe (4) connected to the upper end of the purification tower (1), external supports (3) welded to the top and side outer walls of the purification tower (1), and a dust settling section, a spraying section, and a gas scrubbing section installed sequentially from bottom to top inside the purification tower (1), characterized in that: A return liquid filtration assembly is installed between the spray section and the gas washing section. The gas washing section includes a gas washing cylinder (7) fixedly installed on the upper end of the inner wall of the purification tower (1) and a partition frame (17) installed in the gas washing cylinder (7). A gas washing adjustment assembly for adjusting the degree of gas retention is installed in the partition frame (17).

2. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 1, characterized in that: The air washing adjustment assembly includes multiple air supply columns (22) spaced apart at the bottom of the air washing cylinder (7) and a sleeve rod (30) slidably mounted on the air supply columns (22). Multiple first connecting holes (29) are spaced apart on the air supply columns (22), and multiple second connecting holes (31) are spaced apart on the sleeve rod (30). The two sides of the first connecting holes (29) and the second connecting holes (31) are respectively connected to the spray section and the air washing section.

3. The casting and smelting furnace flue gas denitrification and dust removal treatment device according to claim 2, characterized in that: The top of the sleeve rod (30) is fixedly installed with an air-retaining top plate (18), and multiple air-retaining stacked plates (23) are installed at the lower end of the air-retaining top plate (18). Both the air-retaining top plate (18) and the air-retaining stacked plates (23) are corrosion-resistant porous materials. The air-retaining top plate (18) is placed on the partition frame (17).

4. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 3, characterized in that: Multiple spaced ropes (24) are installed and connected between the air-retaining top plate (18) and the multiple air-retaining stacked plates (23). Both the air-retaining top plate (18) and the multiple air-retaining stacked plates (23) are counterweight adjustment plates adapted to air pressure pushing design.

5. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 1, characterized in that: The spray section includes a central spray packing (9) installed in the purification tower (1), a plurality of connecting columns (19) equidistantly installed on the lower end face of the air scrubbing cylinder (7), and a collection cylinder (6) installed below the spray packing (9). Spray heads (20) are installed at the bottom of each connecting column (19), and a pressure supply connecting plate (21) for transmitting pressure to the spray heads (20) is provided on the lower end face of the air scrubbing cylinder (7).

6. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 5, characterized in that: A reflux guide plate (10) is installed on the inner wall of the purification tower (1) between the collection cylinder (6) and the spray packing (9). Multiple connecting columns (12) for connecting the dust settling section and the spray section are installed at intervals on the collection cylinder (6). A baffle cap (13) is installed on the connecting column (12). A connecting groove (14) is opened on the connecting column (12).

7. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 5, characterized in that: Each of the connecting columns (19) is provided with a connecting through hole for the spray head (20) to connect to the upper end of the air washing section, and a filter baffle (25) is installed at the top of the connecting through hole.

8. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 7, characterized in that: Each of the filter baffles (25) is rotatably mounted with a rotating impeller (26). The rotating impellers (26) are provided with blades (27) at intervals for stirring the reaction liquid in the gas washing section. The lower end of the blades (27) is provided with scrapers (28) for extending into the filter holes of the filter baffles (25).

9. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 1, characterized in that: The return liquid filtration assembly includes a suction circulation box (8) installed at the top of the purification tower (1). Two liquid return pipes (15) are installed at the lower end of the suction circulation box (8). Liquid collection seats (32) are installed at the bottom of each liquid return pipe (15). A filter outlet pipe (16) located above the air washing cylinder (7) is installed at the side end of the suction circulation box (8). The bottom ends of the two liquid return pipes (15) are located on the upper walls of the air washing cylinder (7) and the collection cylinder (6), respectively.

10. The fume denitrification and dust removal device for casting and smelting furnaces according to claim 1, characterized in that: The dust removal section includes an interlaced baffle dust removal plate (5) installed on the side of the air inlet pipe of the purification tower (1) and a flow equalization guide plate (11) installed on the interlaced baffle dust removal plate (5). The interlaced baffle dust removal plate (5) is located at the upper end of the dust discharge pipe (2).

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