An air filtration system

Abstract

The utility model discloses an air filtering system, alkali recovery boiler flue is connected on the electric dust collector, and electric dust collector downstream is connected with ammonia injection system, and ammonia injection system is connected with condensing filter box, the condensing filter box includes the box, and the inside bottom of box is provided with the accumulation groove, and the inside both sides of box are alternately installed with the temperature baffle, and the temperature baffle is connected with the low temperature plate mechanism of symmetrical setting of box outside, the condensing filter box is connected with the filtering mechanism, and the filtering mechanism is connected with the separation cylinder through first conveying pipe, the inside of separation cylinder is connected with compressed air subassembly, and the inside of separation cylinder is installed with the centrifugal fan mechanism of cooperation of compressed air subassembly use. The utility model discloses, the device is to solve the air filtering system in the purification process of existing air filtering system and needs to carry out ammonia injection operation, wherein in the ammonia injection process, flue gas contacts after ammonia molecule, will produce certain amount of sticky material such as ammonium bisulfate, and the sticky material is easy to adhere to the surface of catalyst.

Description

Technical Field

[0001] This utility model relates to the field of air filtration technology, specifically to an air filtration system. Background Technology

[0002] Alkali recovery is a core component of the pulping process in the paper industry. An alkali recovery boiler burns the waste liquor (commonly known as black liquor) from the pulping process, recovering salts such as sodium (Na) and potassium (K). This significantly reduces the pollution load from organic and inorganic emissions during production. The heat generated from combustion can be reused in black liquor evaporation and concentration processes, preventing substantial resource waste. Related research indicates that the main pollutants in the flue gas emitted from alkali recovery boilers during black liquor combustion are particulate matter and NOx. Particulate matter emissions contribute to severe weather such as haze, while NOx emissions damage the ozone layer and can even directly poison humans and animals. NOx is also a major cause of acid rain and acid fog. Therefore, air filtration systems for dust removal and denitrification purification of flue gas from alkali recovery boilers in the paper industry are essential. Existing air filtration systems require ammonia injection during the purification process. During ammonia injection, when flue gas comes into contact with ammonia molecules, a certain amount of viscous substances such as ammonium bisulfate are produced. These viscous substances easily adhere to the catalyst surface, affecting the catalyst's lifespan and thus the denitrification efficiency of the flue gas. Therefore, an air filtration system is proposed to solve the above problems. Utility Model Content

[0003] The purpose of this invention is to provide an air filtration system to solve the problem mentioned in the background art that existing air filtration systems require ammonia injection during the purification process. During ammonia injection, after the flue gas comes into contact with ammonia molecules, a certain amount of viscous substances such as ammonium bisulfate are generated. These viscous substances easily adhere to the catalyst surface, affecting the catalyst's service life and thus the denitrification efficiency of the flue gas.

[0004] To achieve the above objectives, this utility model provides the following technical solution: an air filtration system, including an electrostatic precipitator, the upstream of which is connected to the flue of an alkali recovery boiler, and the downstream of which is connected to an ammonia injection system. The ammonia injection system is connected to a condensation filter box, the condensation filter box including a box body, and a storage tank provided at the bottom of the inner side of the box body. Temperature transfer baffles are alternately installed on both sides of the inner side of the box body, and the temperature transfer baffles are connected to low-temperature plate mechanisms symmetrically arranged on the outer side of the box body. The condensation filter box is connected to a filtration mechanism, and the filtration mechanism is connected to a separation cylinder for centrifugal separation of viscous substances in a mixed gas through a first conveying pipe. The output of the separation cylinder... The end is connected to the SCR denitrification tower (9) through the second conveying pipe (8). The inside of the separation cylinder is connected to the compressed air assembly, and a centrifugal fan mechanism that works with the compressed air assembly is installed inside the separation cylinder. The centrifugal fan mechanism is rotatably arranged between the exhaust hood and the exhaust hood, and the exhaust hood is fixedly installed inside the annular partition. The centrifugal fan mechanism includes a rotating rod, and centrifugal fan blades are fixedly installed on the outside of the rotating rod. One end of the rotating rod is connected to the rotating column, and the outside of the rotating column is connected to the fixed column through symmetrically arranged connecting rods. The fixed column is connected to the L-shaped scraper through the connecting block. The exhaust hood is connected to the SCR denitrification tower through the second conveying pipe.

[0005] Preferably, the bottom of the storage tank is provided with a discharge port, and the opening end of the discharge port is fitted with a matching cap.

[0006] Preferably, the low-temperature plate mechanism includes a low-temperature conductive plate, which is installed inside the temperature transfer baffle. The low-temperature conductive plate is connected to the cooling plate, which is installed on one side of the cooling surface of the semiconductor cooling chip. The heating surface of the semiconductor cooling chip is connected to the heat-conducting plate, and the other side of the heat-conducting plate is connected to the cooling fan through a heat sink. The cooling fan is located inside the mounting slot.

[0007] Preferably, the filtration mechanism includes a filter mounting box, and a filter screen is detachably installed inside the filter mounting box.

[0008] Preferably, the annular partition has symmetrical discharge ports, and the discharge ports are connected to the storage area inside the separation cylinder.

[0009] Preferably, the L-shaped scraper is in contact with the separation cylinder and the annular partition.

[0010] Preferably, the SCR denitrification tower includes an inlet flue, an inlet multi-head chamber, a hot air system, a catalyst chamber, an outlet multi-head chamber, and an outlet flue. The outlet flue is connected to a heat exchanger, and the outlet of the heat exchanger is sequentially equipped with a flue butterfly valve, an induced draft fan, and a chimney.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This air filtration system addresses the problem that existing air filtration systems require ammonia injection during the purification process. During ammonia injection, when flue gas comes into contact with ammonia molecules, a certain amount of viscous substances such as ammonium bisulfate are produced. These viscous substances easily adhere to the catalyst surface, affecting the catalyst's lifespan and thus impacting the denitrification efficiency of the flue gas. By connecting the ammonia injection system to a condensation filter box, which includes a box body with a storage tank at the bottom of the inner side, and alternating temperature transfer baffles installed on both sides of the box body, the temperature transfer baffles are connected to a low-temperature plate mechanism symmetrically arranged on the outer side of the box body. The condensation filter box is connected to a filtration mechanism, and the filtration mechanism is connected via a first conveying pipe to a centrifugal separator for separating viscous substances in the mixed gas. The separator is connected to a compressed air assembly and contains a centrifugal fan mechanism that works in conjunction with the compressed air assembly. The centrifugal fan mechanism is rotatably positioned between the exhaust hood and the inlet hood, with the exhaust hood fixedly installed inside an annular baffle. During operation, the mixed gas enters the condensation filter chamber and comes into contact with a low-temperature heat transfer baffle. The temperature of the mixed gas decreases, causing viscous substances such as ammonium bisulfate and water molecules to condense into droplets that fall into a collection tank for collection. The filtration mechanism can further filter the condensed ammonium bisulfate and other viscous substances. The filtered mixed gas then enters the separator, where the centrifugal fan mechanism centrifuges the ammonium bisulfate and other viscous substances, throwing them against the inner wall of the separator and ultimately into the storage area for storage. This process removes viscous substances such as ammonium bisulfate before the mixed gas enters the SCR denitrification tower, effectively solving the problem of these substances adhering to the catalyst surface and affecting flue gas denitrification efficiency.

[0012] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall front cross-sectional structure of this utility model;

[0014] Figure 2 This is a top view cross-sectional structural diagram of the condenser filter box of this utility model;

[0015] Figure 3 This is a schematic diagram of the internal structure of the separator cylinder of this utility model;

[0016] Figure 4 This is a schematic diagram of the annular partition structure of this utility model.

[0017] In the diagram: 1. Electrostatic precipitator; 2. Condensation filter box; 201. Box body; 202. Storage tank; 2021. Discharge port; 203. Temperature transfer baffle; 204. Low-temperature plate mechanism; 2041. Low-temperature conduction plate; 2042. Cooling plate; 2043. Semiconductor cooling chip; 2044. Heat conduction plate; 2045. Heat dissipation plate; 2046. Cooling fan; 3. Ammonia injection system; 4. Filtration mechanism; 401. Separation cylinder; 4011. Filter mounting box; 4012. Filter screen; 402. Compressed air assembly; 403. Centrifugal fan mechanism; 4031. 4032. Rotating rod; 4033. Centrifugal fan blade; 4034. Rotating column; 4035. Connecting rod; 4036. Fixed column; 4037. Connecting block; 4038. L-shaped scraper; 5. Exhaust hood; 6. Exhaust hood; 7. Annular baffle; 701. Discharge port; 702. Storage area; 8. Second conveying pipe; 9. SCR denitrification tower; 901. Inlet flue; 902. Inlet reducer chamber; 903. Hot air system; 904. Outlet reducer chamber; 905. Outlet flue; 10. Heat exchanger; 11. Flue butterfly valve; 12. Exhaust fan; 13. Chimney. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-4 This utility model provides a technical solution: an air filtration system, wherein an electrostatic precipitator 1 is connected upstream to the flue of an alkali recovery boiler, and downstream to an ammonia injection system 3. The ammonia injection system 3 is connected to a condensation filter box 2, and the condensation filter box 2 is connected to a filtration mechanism 4. The filtration mechanism 4 is connected to a separation cylinder 401 for centrifugal separation of viscous substances in a mixed gas via a first conveying pipe. The inner cavity of the separation cylinder 401 is connected to a compressed air assembly 402, and a centrifugal fan mechanism 403 for use with the compressed air assembly 402 is installed inside the separation cylinder 401. The centrifugal fan mechanism 403 is rotatably disposed between an exhaust hood 5 and an exhaust hood 6, and the exhaust hood 6 is fixedly installed at the center of an annular partition 7.

[0020] To further explain, the ammonia injection system 3 consists of an ammonia injector, an ammonia-air mixer, an ammonia dilution fan, an ammonia-water evaporator, and an ammonia-water tank. The ammonia-water tank is connected to the ammonia-water evaporator, the ammonia-water evaporator is connected to the ammonia-air mixer, the inlet of the ammonia-air mixer is connected to the ammonia dilution fan, and the outlet of the ammonia-air mixer is connected to the ammonia injector.

[0021] Specifically, the condensation filter box 2 includes a box body 201, and a storage groove 202 is provided at the bottom of the inner side of the box body 201. Temperature transfer baffles 203 are alternately installed on both sides of the inner side of the box body 201. By alternately installing the temperature transfer baffles 203, the gas flow rate can be reduced to a certain extent, thereby making the gas condensation more complete. The temperature transfer baffles 203 are connected to a low temperature plate mechanism 204 provided on the outer side of the box body 201. The low temperature plate mechanism 204 includes a low temperature conduction plate 2041, and the low temperature conduction plate 2041 is installed inside the temperature transfer baffles 203. The low temperature conduction plate 2041 is connected to a cooling plate 2042, and the cooling plate 2042 is installed on one side of the cooling surface of the semiconductor cooling chip 2043. The heating surface of the semiconductor cooling chip 2043 is connected to a heat conduction plate 2044, and the other side of the heat conduction plate 2044 is connected to a cooling fan 2046 through a heat dissipation plate 2045. The cooling fan 2046 is located inside the mounting groove.

[0022] To further explain, the housing 201, the temperature transfer baffle 203, and the storage tank 202 are all made of corrosion-resistant and anti-sticking materials.

[0023] In a further embodiment, the bottom of the storage tank 202 is provided with a discharge port 2021, and the opening end of the discharge port 2021 is equipped with a matching cap.

[0024] When it is necessary to reduce the temperature of the heat transfer baffle 203, the thermoelectric cooler 2043 is turned on. Under the action of the thermoelectric cooler 2043, the low temperature is conducted to the cooling plate 2042 and the low temperature conduction plate 2041 through the cooling plate 2042. The heat generated by the heating surface of the thermoelectric cooler 2043 is conducted to the heat sink 2045 through the heat conduction plate 2044. The cooling fan 2046 can dissipate heat from the heat sink 2045.

[0025] Specifically, the filter mechanism 4 includes a filter mounting box 4011, and a filter screen 4012 is detachably installed inside the filter mounting box 4011. The detachable filter screen 4012 facilitates cleaning and replacement of the filter screen 4012 in the future.

[0026] To further explain, the compressed air assembly 402 includes a compressed air tank and a compressed air pipeline. The compressed air tank compresses and stores external air inside it. The output end of the compressed air tank is connected to the compressed air pipeline. The output end of the compressed air pipeline extends through the interior of the separator 401 and points to the centrifugal fan mechanism 403, thereby driving the centrifugal fan mechanism 403 to rotate.

[0027] To further explain, under a specific compressed air pressure (such as 0.8 MPa), the centrifugal fan speed can reach over 2000 RPM, and the separation efficiency is >90%.

[0028] Specifically, the centrifugal fan mechanism 403 includes a rotating rod 4031. One end of the rotating rod 4031 is rotatably connected to a first positioning mounting plate inside the exhaust hood 5. A centrifugal fan blade 4032 is fixedly installed on the outside of the rotating rod 4031. One end of the rotating rod 4031 is connected to a rotating column 4033. The outside of the rotating column 4033 is connected to a fixed column 4035 through symmetrically arranged connecting rods 4034. One end of the rotating column (4033) is rotatably connected to a second positioning mounting plate inside the exhaust hood 6. The fixed column 4035 is connected to an L-shaped scraper 4037 through a connecting block 4036. The exhaust hood 6 is connected to the SCR denitrification tower 9 through a second conveying pipe 8.

[0029] To further explain, the centrifugal fan mechanism 403 is made of a corrosion-resistant and non-sticky material.

[0030] In a further embodiment, the annular partition 7 is symmetrically provided with discharge ports 701, and the discharge ports 701 are connected to the storage area 702 provided inside the separation cylinder 401. By providing discharge ports 701, viscous substances such as ammonium bisulfate can easily enter the storage area 702 through the discharge ports 701.

[0031] To further explain, the L-shaped scraper 4037 is in contact with the separation cylinder 401 and the annular partition 7.

[0032] In a further embodiment, the SCR denitrification tower 9 includes an inlet flue 901, an inlet multi-head chamber 902, a hot air system 903, a catalyst chamber, an outlet multi-head chamber 904, and an outlet flue 905. The outlet flue 905 is connected to the heat exchanger 10, and the outlet of the heat exchanger 10 is sequentially provided with a flue butterfly valve 11, an induced draft fan 12, and a chimney 13.

[0033] In operation, the mixed gas enters the electrostatic precipitator 1 for dust removal. The dust-removed gas is then mixed with ammonia gas through the ammonia injection system 3. The mixed gas then enters the condensation filter box 2 and comes into contact with the low-temperature heat transfer baffle 203. The temperature of the mixed gas decreases, causing viscous substances such as ammonium bisulfate and water molecules to condense into droplets that fall into the accumulation tank 202 for collection. The filtration mechanism 4 can further filter the condensed ammonium bisulfate and other viscous substances. The filtered mixed gas then enters the separation cylinder 401. The centrifugal fan mechanism 403 rotates under the action of the compressed air assembly 402. Under the action of centrifugation, viscous substances such as ammonium bisulfate in the mixed gas are centrifuged, which also makes the ammonia gas more thoroughly mixed. Under the action of centrifugal force, viscous substances such as ammonium bisulfate are thrown towards the inner wall of the separation cylinder 401. The centrifugal fan mechanism 403 can drive the L-shaped scraper 4037 to rotate and move, thereby scraping off the viscous substances such as ammonium bisulfate adhering to the inner wall of the separation cylinder 401. Finally, the gas enters the storage area 702 through the discharge port 701 for storage. The centrifuged gas enters the SCR denitrification tower 9 through the second conveying pipe 8 for denitrification operation. The denitrified gas is finally discharged through the chimney 13 by the induced draft fan 12.

[0034] The terms “center,” “longitudinal,” “lateral,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0035] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air filtration system comprising an electrostatic precipitator (1) and an SCR denitrification tower (9), wherein the electrostatic precipitator (1) is connected upstream to an alkali recovery boiler flue and downstream to an ammonia injection system (3), characterized in that: The ammonia injection system (3) is connected to the condensation filter box (2). The condensation filter box (2) includes a box body (201) and a storage tank (202) is provided at the bottom of the inner side of the box body (201). Temperature transfer baffles (203) are alternately installed on both sides of the inner side of the box body (201). The temperature transfer baffles (203) are connected to the low temperature plate mechanism (204) symmetrically arranged on the outer side of the box body (201). The condensation filter box (2) is connected to the filter mechanism (4). The filter mechanism (4) is connected to a separation cylinder (401) for centrifugal separation of viscous substances in the mixed gas through a first conveying pipe. The output end of the separation cylinder (401) is connected to the SCR denitrification tower (9) through a second conveying pipe (8).

2. The air filtration system according to claim 1, characterized in that: The storage tank (202) has a discharge port (2021) at the bottom, and a matching cap is installed at the opening end of the discharge port (2021).

3. An air filtration system according to claim 1, characterized in that: The low-temperature plate mechanism (204) includes a low-temperature conductive plate (2041), which is installed inside the temperature transfer baffle (203). The low-temperature conductive plate (2041) is connected to the cooling plate (2042), which is installed on the cooling side of the semiconductor cooling chip (2043). The heating side of the semiconductor cooling chip (2043) is connected to the heat-conducting plate (2044), and the other side of the heat-conducting plate (2044) is connected to the cooling fan (2046) through the heat sink (2045). The cooling fan (2046) is located inside the mounting groove.

4. An air filtration system according to claim 1, characterized in that: The filtration mechanism (4) includes a filter mounting box (4011), and a filter screen (4012) is detachably installed inside the filter mounting box (4011).

5. An air filtration system according to claim 1, characterized in that: The separator (401) is connected to the compressed air assembly (402), and a centrifugal fan mechanism (403) is installed inside the separator (401) to cooperate with the compressed air assembly (402). The centrifugal fan mechanism (403) is rotatably disposed between the induced draft hood (5) and the exhaust hood (6), and the exhaust hood (6) is fixedly installed inside the annular partition (7). The exhaust hood (6) is connected to the SCR denitrification tower (9) through the second conveying pipe (8).

6. An air filtration system according to claim 5, characterized in that: The centrifugal fan mechanism (403) includes a rotating rod (4031), and centrifugal fan blades (4032) are fixedly installed on the outside of the rotating rod (4031). One end of the rotating rod (4031) is connected to a rotating column (4033), and the outside of the rotating column (4033) is connected to a fixed column (4035) through symmetrically arranged connecting rods (4034). The fixed column (4035) is connected to an L-shaped scraper (4037) through a connecting block (4036).

7. An air filtration system according to claim 5, characterized in that: The annular partition (7) has symmetrical discharge ports (701) at the beginning, and the discharge ports (701) are connected to the storage area (702) set inside the separation cylinder (401).

8. An air filtration system according to claim 6, characterized in that: The L-shaped scraper (4037) is in contact with the separation cylinder (401) and the annular partition (7).

9. An air filtration system according to claim 1, characterized in that: The SCR denitrification tower (9) includes an inlet flue (901), an inlet end chamber (902), a hot air system (903), a catalyst chamber, an outlet end chamber (904), and an outlet flue (905). The outlet flue (905) is connected to a heat exchanger (10), and the outlet of the heat exchanger (10) is provided with a flue butterfly valve (11), an induced draft fan (12), and a chimney (13) in sequence.

Images