Electro-filtration composite dust removal device

Abstract

The utility model provides an electro-filtration composite dust removal device which is beneficial to collection of fine dust of medium-high temperature flue gas. The electro-filtration composite dust removal device comprises an electrostatic dust removal area and a filtration dust removal area; the filtering dust removal area comprises a filter box system, the filter box system comprises a plurality of filter boxes, each filter box comprises a metal filter screen, each metal filter screen comprises multiple layers of metal nets, and the multiple layers of metal nets are connected in a sintering mode.

Description

Technical Field

[0001] This application relates to the field of dust removal technology, specifically to an electro-filtration composite dust removal device. Background Technology

[0002] Electrostatic precipitators (ESPs), as one of the main technical means of controlling air pollution, are widely used in the treatment of dust-laden flue gas during the sintering process in the steel industry. However, it is difficult to achieve long-term stable control of the outlet dust concentration. Some related technical solutions employ a hybrid ESP-baghouse system, which combines an ESP zone and a baghouse zone. The baghouse zone includes a filter bag. While this improves dust removal efficiency compared to a single ESP or baghouse, it is not suitable for capturing fine dust from medium- and high-temperature flue gas. Utility Model Content

[0003] The purpose of this application is to provide an electrofiltration composite dust removal device that facilitates the collection of fine dust in medium- and high-temperature flue gas.

[0004] To address the aforementioned technical problems, this application provides an electrostatic filtration composite dust removal device, comprising an electrostatic dust removal zone and a filtration dust removal zone; the filtration dust removal zone includes a filter box system, the filter box system includes multiple filter boxes, each filter box includes a metal filter screen, the metal filter screen includes multiple layers of metal mesh, and the multiple layers of metal mesh are sintered together.

[0005] Optionally, the metal filter screen comprises at least three layers of metal mesh, wherein the wire diameter of the outermost two layers of metal mesh is larger than the wire diameter of the remaining layers of metal mesh.

[0006] Optionally, the filter box includes a filter structure, which includes a metal filter and two outer frames, with the metal filter sandwiched between the two outer frames.

[0007] Optionally, the metal filter screen and the outer frame are welded together.

[0008] Optionally, the filter box has a square box structure with two opposing first box sidewalls and two opposing second box sidewalls, wherein at least one of the first box sidewalls and the second box sidewalls is the filter screen structure.

[0009] Optionally, the filter structure is the second box side wall portion, the first box side wall portion is a plate structure, and the filter structure and the plate structure are welded and fixed.

[0010] Optionally, the electro-filtration composite dust removal device includes a rapping mechanism, which includes a rapping rod connected to multiple filter boxes.

[0011] Optionally, the vibration mechanism includes a plurality of vibration rods arranged along a second direction, and further includes a vibration limiting structure disposed between two adjacent vibration rods.

[0012] Optionally, the electro-filtration composite dust removal device has an inlet flue, and the electro-filtration composite dust removal device further includes a cold air valve and / or a heating device, wherein the cold air valve and the heating device are disposed in the inlet flue.

[0013] Optionally, the electro-filtration composite dust removal device further includes a tube sheet sealing structure, which includes a pressing plate, a locking assembly, a sealing gasket, and a support plate.

[0014] The clamping plate is provided with perforated plate holes, the filter box has a top opening, the clamping plate covers the filter box, and the perforated plate holes and the top opening are opposite to each other;

[0015] The support plate is located on the outside of the filter box, and the sealing gasket is provided between the pressure plate and the support plate around its perimeter. The locking assembly fixes the support plate and the pressure plate.

[0016] The electrostatic precipitator and filtration combined dust collector in this application includes an electrostatic precipitator zone and a filtration zone, combining the advantages of both electrostatic precipitators and bag filters. Furthermore, the filter box in the filtration zone includes a metal filter screen with conductive properties. Charged dust particles are adsorbed onto the surface of the metal filter screen under electrostatic force, forming a flocculent, relatively thick, and well-permeable powder cake layer on the surface. This significantly enhances the capture of fine dust and improves dust collection efficiency. Compared to bag filters, the metal filter screen also has the advantage of high-temperature resistance, making it suitable for dust removal of medium- and high-temperature flue gas. In addition, the metal filter screen is made of multiple layers of sintered metal mesh, resulting in higher filtration precision. It also offers diverse combination options, exhibiting good air permeability and low flow resistance, making it even more conducive to collecting fine dust and aerosol particles. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an electrofiltration composite dust removal device according to an embodiment of this application;

[0018] Figure 2 for Figure 1 A top view of the electrostatic filtration combined dust removal device;

[0019] Figure 3 for Figure 1 Left view of the electrostatic precipitator combined with dust removal device;

[0020] Figure 4 For Figure 1 Schematic diagram of the structure of the middle filtration and dust removal zone;

[0021] Figure 5 for Figure 3Schematic diagram of the middle filter box system;

[0022] Figure 6 for Figure 5 A magnified view of part A in the middle;

[0023] Figure 7 for Figure 5 A schematic diagram of the structure of the middle filter screen;

[0024] Figure 8 for Figure 7 A top view of the middle filter structure;

[0025] Figure 9 for Figure 8 Enlarged diagram of part B in the middle.

[0026] Figure 10 for Figure 5 A schematic diagram of the sealing structure of the central perforated plate.

[0027] The annotations in the attached figures are explained as follows:

[0028] 1-Inlet flue; 11-Front-end inlet flue; 12-Rear-end inlet flue;

[0029] 2-Electrostatic dust removal area; 21-First housing; 22-Electrode system;

[0030] 3-Dust removal and filtration area; 31-Second housing; 32-Filter box system; 321-Filter box; 321a-Top opening; 3211-Filter screen structure; 32111-Outer frame; 32112-Metal filter screen; 3212-Side wall of first housing; 322-Tube plate sealing structure; 3221-Pressure plate; 3221a-Tube plate hole; 3222-Locking assembly; 3223-Sealing gasket; 3224-Sealing block; 3225-Support plate; 33-Bracket; 34-Vibration mechanism; 342-Vibration rod; 341-Vibration limiting structure; 343-Connecting plate;

[0031] 4-Clean air chamber;

[0032] 5-Exit flue;

[0033] 6-Cold air valve;

[0034] 7-Heating device;

[0035] 8-Distribution plate;

[0036] 9-Grey hopper. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] In the embodiments of this application, the terms "first" and "second" are mainly used to distinguish the same or similar features, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0039] Please refer to Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of an electrofiltration composite dust removal device according to an embodiment of this application; Figure 2 for Figure 1 A top view of the electrostatic filtration combined dust removal device; Figure 3 for Figure 1 Left view of the electro-filtration composite dust removal device.

[0040] The electrostatic precipitator and filtration combined dust collector used in this embodiment includes an inlet flue 1, an electrostatic precipitator zone 2, a filtration zone 3, a clean air chamber 4, and an outlet flue 5. The inlet flue 1 is used to introduce flue gas into the electrostatic precipitator and filtration combined dust collector, and is connected to the electrostatic precipitator zone 2. The electrostatic precipitator zone 2 and the filtration zone 3 are directly connected, and the electrostatic precipitator zone 2 is located in front of the filtration zone 3, i.e., upstream of the filtration zone 3. Furthermore, the clean air chamber 4 is connected to the filtration zone 3, specifically positioned above the filtration zone 3. The outlet flue 5 is connected to the clean air chamber 4 and is used to discharge flue gas.

[0041] In this embodiment, an induced draft fan can also be installed outside the inlet flue 1. The induced draft fan can ensure better flow of flue gas into the electrostatic filtration composite dust removal device, making the flue gas flow more stable. Along the flow direction of the flue gas, the aforementioned inlet flue 1, electrostatic dust removal zone 2, filtration dust removal zone 3, clean air chamber 4, and outlet flue 5 are distributed in sequence.

[0042] Flue gas enters through inlet flue 1 and then enters electrostatic precipitator 2 for preliminary dust removal. Electrostatic precipitator 2 is located in front of filtration and dust removal zone 3. After preliminary dust removal, the flue gas continues to filtration and dust removal zone 3 for further cleaning and filtration. This electrostatic-filtration hybrid dust removal device effectively combines electrostatic dust removal and mechanical filtration, which can improve the adsorption efficiency of dust in flue gas, better achieve flue gas cleaning, and meet the cleaning needs of different complex flue gases. Clean air chamber 4 is located above filtration and dust removal zone 3, and outlet flue 5 is directly connected to clean air chamber 4. Outlet flue 5 is also located above filtration and dust removal zone 3 and is connected to downstream equipment, such as an exhaust chimney.

[0043] like Figure 1As shown, the electro-filtration composite dust removal device also includes a cold air valve 6 and a heating device 7. Both the cold air valve 6 and the heating device 7 can be used to adjust the flue gas temperature to achieve better filtration and dust removal effects. Specifically, the cold air valve 6 is used to address the problem of excessively high flue gas temperature when the sintering machine head is not operating normally (such as during a shutdown). In this case, the valve is opened to increase the volume of cold air for cooling. The heating device 7 is used to heat the flue gas to above the dew point when the flue gas temperature is too low during the start-up phase of the sintering machine system, ensuring maximum efficiency during flue gas treatment.

[0044] Furthermore, the inlet flue 1 in this embodiment may include a front inlet flue 11 with a constant diameter and a rear inlet flue 12 with a gradually increasing diameter along the air intake direction. Due to the constant diameter design of the front inlet flue 11, according to the gas equation, the temperature of the flue gas in the front inlet flue 11 will remain stable. The cold air valve 6 and the heating device 7 are both located in the front inlet flue 11, which facilitates more accurate temperature regulation of the flue gas. At the same time, the real-time temperature can be displayed by adding sensors.

[0045] As for the rear inlet flue 12, which can also be called the inlet horn, the flow rate of the flue gas will gradually decrease as the cross-sectional area increases. This decrease in flow rate ensures that the flue gas passes slowly through the electrostatic precipitator zone 2, the filtration zone 3, and the clean air chamber 4, thus improving the dust removal and cleaning effect. The electrostatic filtration composite dust removal device in this embodiment also includes a distribution plate 8, which is disposed in the rear inlet flue 12. This distribution plate 8 can further distribute the airflow evenly, allowing the flue gas to enter the front electrostatic precipitator zone 2 uniformly, thereby improving the dust removal effect.

[0046] Both the electrostatic precipitator zone 2 and the filtration zone 3 are equipped with dust hoppers 9 (shown below). Figure 1 , 2 This allows for better collection of dust from the flue gas, preventing it from accumulating in the electrostatic dust removal zone 2 and the filtration dust removal zone 3, thus affecting the dust removal effect.

[0047] The electrostatic precipitator zone 2 includes a first housing 21, inside which is an electrode system 22. The electrode system 22 includes a cathode and an anode, used to generate an electric field to charge the dust particles in the flue gas. The charged dust particles can move to the anode under the action of the electric field and be collected. The collected dust particles can fall into the ash hopper 9 after being shaken, thereby achieving the effect of electrostatic precipitator.

[0048] Please continue to refer to this. Figure 4 , Figure 4 For Figure 1 A schematic diagram of the structure of the middle filtration and dust removal zone 3.

[0049] The dust removal filtration zone 3 in this embodiment includes a second housing 31, a filter box system 32, a support 33, and a vibrating dust removal device 34. The second housing 31 protects the internal structure and restricts flue gas flow. The filter box system 32 is located inside the second housing 31, at the upper part of the dust removal filtration zone 3, and is a major component of the zone, used for efficient end-of-pipe dust removal. The support 33 is located at the lower part of the dust removal filtration zone 3, providing support and ensuring the stability of the device; the support 33 is, for example, a steel support. The vibrating dust removal device 34 is located below the filter box system 32, vibrating the filtered dust within the system to collect it in the ash hopper 9 below.

[0050] Please continue to refer to this. Figures 5 to 8 , Figure 5 for Figure 3 Schematic diagram of the structure of the middle filter box system 32; Figure 6 for Figure 5 A magnified view of part A in the middle; Figure 7 for Figure 5 Schematic diagram of the structure of the middle filter screen 3211; Figure 8 for Figure 7 A top view of the middle filter structure 3211; Figure 9 for Figure 7 Enlarged diagram of part B in the middle.

[0051] like Figure 5 As shown, the filter box system 32 includes multiple filter boxes 321, each filter box 321 including a filter screen structure 321 and a tube sheet sealing structure 322. The filter screen structure 3211 includes an outer frame 32111 and a metal filter screen 32112. The metal filter screen 32112 is disposed within the outer frame 32111, which is a square frame structure and can be made of steel plate. The metal filter screen 32112 can be made by high-temperature sintering three layers of 316L stainless steel wire mesh with different mesh sizes, i.e., multiple metal meshes are sintered and connected. Depending on different flue gas conditions, an economical and practical metal mesh can be selected, or more layers of metal mesh can be sintered. Multiple layers of metal mesh can meet the requirements of strength and filtration accuracy. Furthermore, the wire diameters of the multiple layers of metal mesh can be set to different values. The outermost metal mesh with a larger wire diameter serves as a reinforcing layer, while the remaining layers with smaller wire diameters serve as the filtration layer, i.e., the filtration layer is located between the two outermost reinforcing layers. As can be seen, the metal filter 32112 can be made of multiple layers (i.e., at least two layers) of metal mesh sintered together, with various combination forms. It has the characteristics of good air permeability and low flow resistance, and is effective in collecting fine dust and aerosol particles.

[0052] like Figure 7As shown, in this embodiment, the metal filter 32112 of the filter structure 3211 is sandwiched between two outer frames 32111. Specifically, the metal filter 32112 is sandwiched between the two outer frames 32111, that is, the outer frames 32111 wrap the metal filter 32112. The connection between the two is a wrapping connection, which improves the structural strength of the filter structure 3211 without affecting the filtration effect of the metal filter 32112.

[0053] The filter box 321 is specifically a square box structure with two opposing first box side walls and two opposing second box side walls. All side walls can be filter screen structures 3211, or only the two opposing second box side walls can be filter screen structures 3211. The two opposing first box side walls 3212 can be plate structures, such as C-shaped or U-shaped structural members. The plate structure can be steel plate, more specifically, C-shaped steel, U-shaped steel, or channel steel. The width sides of the filter screen structures 3211 and the width sides of the plate structures can be welded and fixed. In other words, the filter box 321 primarily uses two opposing filter screen structures 321 for filtration. Figure 6 The diagram shows that the filter box 321 is a relatively thin cuboid structure. The two large surfaces are filter screen structures 3211, which realize the filtration function, while the two small surfaces are plate structures, which mainly serve to connect the filter screen structures 3211 and can improve the structural strength of the filter box 321.

[0054] The manufacturing process of the filter structure 3211 in this embodiment is as follows:

[0055] Two outer frames 32111 are used to clamp and fix the metal filter screen 32112. The thickness of the outer frame 32111 can be 1~2mm. Then, the metal filter screen 32112 is tightened with a clamp so that the metal filter screen 32112 is tensioned in the outer frame 32111.

[0056] Then, the metal filter screen 32112 is spot-welded to the outer frame 32111. The spot welding method can be laser welding or argon arc welding, etc. After the spot welding is completed, roll welding is performed on the outer frame 32111 to increase the reliability of the connection between the metal filter screen 32112 and the outer frame 32111, so as to form the filter structure 3211. It can be seen that the filter structure 321 is formed by edge welding, which has good sealing performance and can effectively prevent flue gas from escaping.

[0057] The fabricated filter structure 3211 and the first side wall 3212 of the filter box 321 are fixed to the first side wall 3212 of the filter box using a continuous welding process. Continuous welding offers stable quality, high efficiency, and can be automated. Of course, the filter structure 3211 can also be fixed to the first side wall 3212 of the filter box using other methods, such as clips, rivets, roll welding, or manual welding. However, continuous welding improves production efficiency and better ensures stable welding quality, avoiding problems such as melting of the metal filter screen 32112 during processing and easy detachment of the fixing point due to hole expansion.

[0058] In this embodiment, the metal filter 32112, while filtering dust, also possesses conductive properties. Charged dust particles are adsorbed onto the surface of the metal filter 32112 under the action of electrostatic force, forming a flocculent powder cake layer of a certain thickness and good air permeability on the surface of the metal filter 32112. This can greatly capture fine dust and improve dust collection efficiency. Under the action of mechanical vibration or sonic cleaning force, some dust is peeled off, but a powder cake layer of a certain thickness is still retained, achieving filter cleaning with stable pressure differential. For example, when used for dust removal in sintering machines, the raw materials of the sintering machine contain a large amount of substances such as NaCl, KCl, and MgCl2. During the high-temperature sintering process, a large amount of gaseous salt substances and potassium and sodium oxides will be generated. After entering the electrostatic precipitator zone and the temperature decreases, they will condense and crystallize into needle-like flocculent substances with extremely low density (only 0.13t / m3-0.5t / m3), high resistivity (1011~1012Ω·cm), and fine particle size. The proportion of dust particles smaller than 5μm is more than 30%. The dust is fine and viscous, and it floats in the electric field, making it difficult to capture and clean. After adopting the electro-filtration composite dust removal device in this embodiment, it is beneficial to effectively capture the dust, adapt to ultra-low emissions under the complex flue gas conditions at the sintering machine head, and effectively improve the service life of the electro-filtration composite dust collector.

[0059] like Figure 6 As shown, the filter box system 32 includes a vibration mechanism 34, which includes a vibration rod 342, a connecting plate 343, and a bolt assembly. Multiple filter boxes 321 can be connected to a vibration rod 342 in a row via the connecting plate 343 and the bolt assembly. The arrangement direction of the row is a first direction, and the multiple rows of filter boxes 321 are arranged along a second direction, which is perpendicular to the first direction. The rows of filter boxes 321 are limited by a vibration limiting structure 341, which is positioned between adjacent vibration rods 342 to restrict the movement of the vibration rods 342 along the second direction, thereby ensuring the distance between each row of filter boxes 321. The vibration limiting structure 341 is, for example, a... Figure 6 The U-shaped plate shown has one side connected to a vibrating rod 342 and the other side connected to another adjacent vibrating rod 342.

[0060] Therefore, in this embodiment, multiple filter boxes 321 are arranged in rows, and each row of filter boxes 321 can be connected to a vibrating rod 342. This allows for vibration cleaning via the vibration mechanism 34, resulting in better cleaning performance compared to the blowing cleaning of ordinary filter bags. Furthermore, in this embodiment, the filter box 321 is designed as a square box structure through the filter mesh structure 3211, which facilitates connection to the vibrating rod 342 and allows multiple filter boxes 321 to be arranged in an array, making it easier to achieve uniform vibration cleaning.

[0061] Please refer to this again. Figure 10 , Figure 10 for Figure 5 Schematic diagram of the sealing structure 322 of the central panel.

[0062] The tube sheet sealing structure 322 ensures that flue gas does not leak during dust removal. The tube sheet sealing structure 322 includes a pressure plate 3221, a locking assembly 3222, a sealing gasket 3223, a sealing block 3224, and a support plate 3225. A support plate 3225 is installed outside the filter box 321, positioned between adjacent filter boxes 321. A pressure plate 3221 is also installed on the upper part of the filter box 321. The filter box 321 has a top opening 321a, and the pressure plate 3221 covers the filter box 321, with the tube sheet opening 3221a facing the top opening 321a to allow filtered flue gas to flow upwards from the tube sheet opening 3221a. Sealing gaskets 3223 and sealing blocks 3224 are installed around the pressure plate 3221 and between it and the support plate 3225 to achieve a better sealing effect. Figure 8 The central sealing block 3224 is sandwiched between two sealing gaskets 3223. The sealing block 3224 reduces the thickness of the sealing gaskets 3223, ensuring a good seal. Simultaneously, the tube sheet sealing structure 322 is fixed to the support plate 3225 via a locking assembly 3222 that penetrates the pressure plate 3221, improving the stability and reliability of the seal. It is evident that the outer frame 32111 of the filter structure 3211 also facilitates a sealing connection with the tube sheet sealing structure 322.

[0063] In summary, the filtration and dust removal zone 3 of the electro-filtration composite dust removal device provided in this embodiment includes multiple filter boxes 321. Each filter box 321 includes a filter screen structure 3211. The filter box 321 has a large filtration area, low filtration velocity, and low equipment resistance, and can adapt to complex flue gas and dust characteristics. This helps to solve the adverse effects of fly ash adhesion, composition, and other properties on emissions from electrostatic precipitators. For example, it can be used in dust removal in sintering machines.

[0064] In addition, the metal filter 32112 is sealed by welding the outer frame 32111, which can effectively prevent the escape of flue gas from affecting the emission of excessive emissions. At the same time, the metal filter 32112 is sintered with metal mesh of different layers and mesh counts, and the samples are diverse. It can be used to treat different flue gas properties in a targeted manner. For example, when it is used for dust removal in sintering machines, it can effectively avoid the adverse effects of sintering process fluctuations, high resistivity dust, and low resistivity dust.

[0065] In addition, the electro-filtration composite dust removal device is also equipped with a cold air valve 6 and a heating device 7. Through the temperature detection and feedback system, the flue gas can be autonomously regulated to ensure that the flue gas always operates safely above the dew point temperature. This avoids the impact of problems such as "bag clogging" on the system resistance and ensures that the sintering machine operates within a stable negative pressure range, thereby ensuring the output and quality of sintered ore.

[0066] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An electro-filtration composite dust removal device, characterized in that, It includes an electrostatic dust removal area (2) and a filtration dust removal area (3); the filtration dust removal area (3) includes a filter box system (32), the filter box system (32) includes multiple filter boxes (321), the filter box (321) includes a metal filter screen (32112), the metal filter screen (32112) includes multiple layers of metal mesh, and the multiple layers of metal mesh are sintered together.

2. The electro-filtration composite dust removal device according to claim 1, characterized in that, The metal filter (31112) comprises at least three layers of the metal mesh, wherein the wire diameter of the outermost two layers of the metal mesh is greater than that of the remaining layers of the metal mesh.

3. The electro-filtration composite dust removal device according to claim 1, characterized in that, The filter box (321) includes a filter structure (3211), which includes a metal filter (32112) and two outer frames (32111). The metal filter (32112) is sandwiched between the two outer frames (32111).

4. The electro-filtration composite dust removal device according to claim 3, characterized in that, The metal filter (32112) and the outer frame (32111) are fixed by edge welding.

5. The electro-filtration composite dust removal device according to claim 3, characterized in that, The filter box (321) is a square box structure with two opposing first box sidewalls and two opposing second box sidewalls, at least one of the first box sidewalls and the second box sidewalls being the filter structure (3211).

6. The electro-filtration composite dust removal device according to claim 5, characterized in that, The filter structure (3211) is the second box side wall, and the first box side wall is a plate structure. The filter structure (3211) and the plate structure are welded and fixed.

7. The electro-filtration composite dust removal device according to any one of claims 1-6, characterized in that, The electrofiltration composite dust removal device includes a rapping mechanism (34), which includes a rapping rod (342) and is connected to a plurality of filter boxes (321).

8. The electro-filtration composite dust removal device according to claim 7, characterized in that, The vibrating mechanism (34) includes a plurality of vibrating rods (342) arranged along a second direction, and also includes a vibrating limiting structure (341) disposed between two adjacent vibrating rods (342).

9. The electro-filtration composite dust removal device according to any one of claims 1-6, characterized in that, The electro-filtration composite dust removal device has an inlet flue (1), and the electro-filtration composite dust removal device also includes a cold air valve (6) and / or a heating device (7), the cold air valve (6) and the heating device (7) being disposed in the inlet flue (1).

10. The electro-filtration composite dust removal device according to any one of claims 1-6, characterized in that, The electro-filtration composite dust removal device also includes a tube sheet sealing structure (322), which includes a pressing plate (3221), a locking assembly (3222), a sealing gasket (3223), and a support plate (3225). The clamping plate (3221) is provided with a perforated plate hole (3221a), the filter box (321) has a top opening (321a), the clamping plate (3221) covers the filter box (321), and the perforated plate hole (3221a) and the top opening (321a) are opposite to each other; The support plate (3225) is located on the outside of the filter box (321), and the sealing gasket (3223) is provided between the pressure plate (3221) and the support plate (3225). The locking assembly (3222) fixes the support plate (3225) and the pressure plate (3221).

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