Desulfurization smoke dust recycling system

Abstract

The utility model belongs to the technical field of flue gas treatment, and discloses a desulfurization smoke dust recycling system which comprises a desulfurization tower, a dust remover, a granulation device and a circulating desulfurizer conveying device. According to the system, a spraying device in the desulfurizing tower is replaced by the high-pressure water gun, so that the atomization effect is good, the contact area of water, flue gas and a desulfurizing agent is increased, the desulfurizing agent is fully utilized, and the desulfurizing agent cost of an enterprise is reduced; gas carrying desulfurizer-containing dust from the desulfurizing tower is dedusted and dedusted by the deduster, desulfurized gas is discharged, the dust enters the ash hopper, is granulated by the granulating device and then flows into the desulfurizing tower by the circulating desulfurizer conveying device, so that the reutilization of the desulfurizer is realized, the resource is saved, and the cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of flue gas treatment technology, specifically relating to a desulfurization flue dust recycling system. Background Technology

[0002] The fumes emitted during the production of industrial aluminum electrolysis cells contain a large number of pollutants, including fluorides, dust, and sulfur dioxide. These fumes, permeating the electrolysis workshop, worsen working conditions and seriously affect the health of production workers. Furthermore, the spread of these fumes to the surrounding area pollutes the atmosphere, posing a significant threat to agricultural and livestock production and people's lives. Therefore, it is essential to efficiently collect the fumes emitted from the electrolysis cells, improve the working environment in the electrolysis workshop, and centrally treat the fumes to recover harmful components and ensure that the fumes are discharged in compliance with standards.

[0003] Currently, the electrolytic aluminum industry generally uses defluorination + desulfurization technology to treat electrolytic aluminum flue gas. The electrolytic flue gas is defluorinated in the defluorination tower and then enters the desulfurization tower. After reacting with desulfurizing agent and spray water in the desulfurization tower, the dust-containing flue gas enters the dust collector for dust removal. After dust removal, the gas is discharged, and the dust containing desulfurizing agent is transported back to the desulfurization tower for recycling as a circulating desulfurizing agent. However, in actual operation, the desulfurization system still has the following problems: (1) The spray device in the desulfurization tower is now set with spray pipes and spray heads. The water mist distribution area is small, resulting in a small contact area between water, flue gas and desulfurizing agent. In order to desulfurize better, more desulfurizing agent calcium hydroxide needs to be used. The monthly usage is 2000-2500 tons, and the enterprise purchase cost is high; (2) The circulating desulfurizing agent is generally transported to the desulfurization tower by pneumatic (multiple fans) for desulfurization. The efficiency is low and the power consumption is high; (3) The circulating desulfurizing agent enters the desulfurization tower in the form of dust. Its distribution uniformity is poor, and it is easy to stick to the tower wall after entering the desulfurization tower and encountering water. Utility Model Content

[0004] The purpose of this invention is to provide a desulfurization flue gas recycling system to solve some or all of the technical problems mentioned in the background art.

[0005] This utility model is implemented by the following technical solution:

[0006] A desulfurization flue gas recycling system includes a desulfurization tower and a dust collector. The outlet of the desulfurization tower is connected to the inlet of the dust collector. Several high-pressure water guns are installed inside the desulfurization tower, equidistantly arranged along the inner wall of the tower. The system also includes a granulation device and a circulating desulfurizing agent conveying device. The circulating desulfurizing agent conveying device includes a material chamber, with one end near the granulation device inclined downwards towards the end near the desulfurization tower to facilitate the downward flow of the circulating desulfurizing agent. An air chamber is located below the material chamber, and its inlet is connected to a compressed air pipeline. A fluidized bed, also known as vulcanized cloth, gasification cloth, or gasification cloth for thermal power plants, is installed between the gas chamber and the fluidized bed. It is a type of breathable cloth used to support the conveyed material and allows compressed air to pass through it evenly to fluidize the circulating desulfurizing agent, thereby improving conveying efficiency. While compressed air passes through, the granular circulating desulfurizing agent will not get stuck in the corners of the fluidized bed. The ash outlet of the dust collector's ash hopper is connected to the feed inlet of the granulation device, the discharge outlet of the granulation device's collection hopper is connected to the feed inlet of the material chamber, and the discharge outlet of the material chamber is connected to the circulating desulfurizing agent inlet of the desulfurization tower. By replacing conventional spray heads with high-pressure water guns, the atomization effect is improved, increasing the contact area between water and flue gas, as well as the desulfurizing agent and circulating desulfurizing agent, thus achieving full utilization of the desulfurizing agent. After the gas containing desulfurizing agent dust exiting from the top of the desulfurization tower is dedusted by a bag filter, the desulfurized gas is discharged, and the desulfurizing agent dust enters the ash hopper. After being granulated by a granulation device, it flows into the desulfurization tower through a circulating desulfurizing agent conveying device for reuse, saving resources and further reducing the cost of using the desulfurizing agent. The circulating desulfurizing agent conveying device can be connected to a compressed air pipeline to enable the circulating desulfurizing agent to enter the desulfurization tower without the need for additional equipment such as fans, saving electricity and achieving a high circulation rate.

[0007] Furthermore, the granulation device is located directly below the dust collector's ash hopper. This allows the desulfurizing agent-containing dust to fall directly into the granulation device and flow downwards along the structure, eliminating the need for other conveying structures and saving costs and floor space.

[0008] Furthermore, the granulation device includes a shell, and the shell includes a humidification zone, an extrusion zone, and a granulation zone from top to bottom. The humidification zone is equipped with several atomizing nozzles, which can humidify the dust containing desulfurizing agent, so that the dust containing desulfurizing agent becomes wet and continues to move downward. Below the atomizing nozzles is a guide plate, which is bucket-shaped. Under the premise of controlling the water volume, the wet material is only humidified by water mist and will not stick together into a paste. Therefore, it will not stay on the guide plate, but will move downward along the structure of the guide plate. The extrusion zone, from top to bottom, includes a first pair of rollers and several sets of second pairs of rollers. The roller spacing of the second pairs of rollers is smaller than that of the first pairs of rollers, facilitating further extrusion of the wet material after extrusion by the first pairs of rollers into sheet form, and extrusion of the wet material that has not been extruded by the first pairs of rollers. The material discharge port of the guide plate is located directly above the first pairs of rollers. The granulation zone includes a guide cone, facilitating the material to fall along the guide cone into the receiving platform. The guide cone is fixed inside the outer shell by a fixing frame. A motor is fixed inside the guide cone, and a bearing is installed at the bottom of the guide cone. The motor is connected to a drive shaft, and a grinding pestle is connected to the lower part of the drive shaft. At least one fixed seat is provided inside the grinding pestle. The drive shaft is rotatably inserted into the bearing and fixed in the fixed seat, facilitating the motor to drive the drive shaft to rotate the grinding pestle. The bottom of the grinding pestle is concave upward in the middle, forming a ring-shaped grinding section around it. At least one material discharge notch is provided on the outer wall of the grinding section to facilitate the material to fall. A receiving platform is provided below the grinding pestle. The material holding platform has a bucket-shaped sidewall and its top is fixed to the inner wall of the outer shell. The bottom of the platform has a raised frustum at its center, and annular grinding troughs (which function as screens) surround the bottom. The dimensions of the grinding troughs are adapted to the dimensions of the grinding section. The grinding pestle rotates under the action of a motor, causing the grinding section to push and crush the material onto the grinding troughs. After passing through the grinding troughs, the material becomes granular circulating desulfurizing agent. A collection hopper is located below the material holding platform. This granulation device can humidify, compress, and granulate desulfurizing agent-containing dust into granules for use as circulating desulfurizing agent. The granules will not get stuck on the fluidized bed in the circulating desulfurizing agent conveying device and are less prone to clumping or sticking to the walls inside the desulfurization tower.

[0009] Furthermore, the humidification zone is provided with several buffer plates, which are inclined from top to bottom. The upper part of the buffer plate is fixed to the inner wall of the outer shell. The buffer plate is located above the atomizing nozzle, so as to allow the desulfurizing dust entering the granulation device to fall slowly.

[0010] Furthermore, the water inlet of the atomizing nozzle is connected to a water inlet pipeline, and a solenoid valve and a flow meter are installed on the water inlet pipeline to facilitate the control of water volume.

[0011] Furthermore, the first pair of rollers has several roller teeth on its roller skin, which facilitates pushing the wet material forward in the opposite direction, reduces the situation where the wet material falls without being squeezed, and can squeeze the wet material better.

[0012] Furthermore, a scraper is provided below each pair of the second rollers, and the top of the scraper contacts the roller skin of the second pair of rollers; the scraper is mounted on a scraper shaft, and the scraper shaft is fixed to the inner wall of the outer casing.

[0013] Furthermore, the inclination angle of the material chamber is 10~45°.

[0014] Beneficial effects:

[0015] This invention provides a desulfurization flue dust recycling system, which has the following advantages:

[0016] (1) The spray device inside the desulfurization tower is replaced with a high-pressure water gun, which has a good atomization effect, increases the contact area between water and flue gas and desulfurizing agent, and thus realizes the full utilization of desulfurizing agent and reduces the desulfurizing agent cost of enterprises.

[0017] (2) The gas carrying desulfurizing agent dust coming out from the top of the desulfurization tower is removed by a dust collector. After dust removal, the desulfurization gas is discharged and the dust enters the ash hopper. After being made into granules by the granulation device, it flows into the desulfurization tower by the circulating desulfurizing agent conveying device, realizing the reuse of desulfurizing agent, saving resources and reducing costs.

[0018] (3) The granulation device can humidify, compress and granulate the dust containing desulfurizing agent into granules as circulating desulfurizing agent. It will not get stuck on the boiling plate in the circulating desulfurizing agent conveying device, and it is not easy to agglomerate or stick to the wall in the desulfurization tower, which reduces the problem of equipment scaling during operation and extends the equipment maintenance cycle.

[0019] (4) The circulating desulfurizing agent conveying device adopts the structure of inclined material chamber + boiling plate + air chamber. It can be connected to the compressed air pipeline to realize the circulating desulfurizing agent entering the desulfurization tower without the need to add equipment such as fans, saving power consumption and having a high circulation rate. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the desulfurization flue dust recycling system;

[0022] Figure 2 This is a schematic diagram of the desulfurization unit;

[0023] Figure 3 This is a schematic diagram of the structure of the first pair of rollers;

[0024] Figure 4 This is a schematic diagram of the structure of a grinding pestle;

[0025] Figure 5 This is a schematic diagram of the material receiving platform.

[0026] The attached diagrams are described as follows: 10. Desulfurization tower; 11. High-pressure water gun; 20. Dust collector; 30. Granulation device; 301. Humidification zone; 302. Extrusion zone; 303. Granulation zone; 31. Outer shell; 32. Buffer plate; 33. Atomizing nozzle; 331. Solenoid valve; 332. Flow meter; 34. Guide plate; 351. First pair of rollers; 352. Roller teeth; 353. Second pair of rollers; 354. 355. Scraper shaft; 36. Scraper; 371. Guide cone; 372. Fixing frame; 373. Motor; 374. Drive shaft; 375. Bearing; 376. Fixing seat; 377. Grinding pestle; 378. Grinding section; 379. Material drop notch; 38. Material holding platform; 39. Grinding trough; 40. Frustum; 41. Collecting hopper; 42. Circulating desulfurizing agent conveying device; 43. Material chamber; 44. Gas chamber. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In the description of the present utility model, it should be noted that the terms "middle", "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, 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, and therefore should not be construed as a limitation of the present utility model. 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.

[0028] Example

[0029] A desulfurization flue gas recycling system, such as Figure 1As shown, it includes a desulfurization tower 10, a dust collector 20, a granulation device 30, and a circulating desulfurizing agent conveying device 40. The outlet of the desulfurization tower 10 is connected to the inlet of the dust collector 20, the outlet of the dust collector 20's ash hopper is connected to the inlet of the granulation device 30, the outlet of the granulation device 30 is connected to the inlet of the material chamber 41 of the circulating desulfurizing agent conveying device 40, and the outlet of the material chamber 41 is connected to the inlet of the desulfurization tower 10.

[0030] The desulfurization tower 10 has a desulfurizing agent inlet, a circulating desulfurizing agent inlet, and a flue gas inlet on its lower side wall. Ten high-pressure water guns 11 are installed inside the desulfurization tower 10, two of which are spares. In this embodiment, the high-pressure water guns 11 are high-pressure reflux spray guns, and are equidistantly arranged along the inner wall of the desulfurization tower. Each high-pressure water gun 11 is connected to a water inlet pipeline. In this embodiment, the dust collector 20 is a bag filter dust collector, with an exhaust port at the top and an ash hopper at the bottom.

[0031] like Figure 2-4As shown, the granulation device 30 is located directly below the dust collector 20's ash hopper. The granulation device 30 includes a shell 31, which contains, from top to bottom, a humidification zone 301, an extrusion zone 302, and a granulation zone 303. The shell 31 of the humidification zone 301 and the extrusion zone 302 has a rectangular cross-section, while the shell 31 of the granulation zone 303 has a circular cross-section. Two buffer plates 32 are installed in the humidification zone 301. The buffer plates 32 are smooth sliding plates that slope downwards. The upper part of the buffer plates 32 is fixed to the inner wall of the shell 31, and the lower part is flush with the longitudinal central axis of the granulation device 30. Several atomizing nozzles 33 are installed below the buffer plates 32. The water inlets of the atomizing nozzles 33 are connected to water inlet pipes, and solenoid valves 331 and flow meters 332 are installed on the water inlet pipes. A guide plate 34 is installed below the atomizing nozzles 33. The guide plate 34 is hopper-shaped. The extrusion zone 302 includes, from top to bottom, a first pair of rollers 351 and three sets of second pairs of rollers 353; the discharge port of the guide plate 34 is located directly above the first pair of rollers 351, and the roller skin of the first pair of rollers 351 is provided with a number of roller teeth 352; the roller spacing of the second pair of rollers 353 is smaller than the roller spacing of the first pair of rollers 351; a scraper 355 is provided below the rollers of each set of second pairs of rollers 353, and the top of the scraper 355 is in contact with the roller skin of the second pair of rollers 353; the scraper 355 is mounted on a scraper shaft 354, and the scraper shaft 354 is fixed to the inner wall of the outer casing 31. The granulation zone 303 includes a guide cone 36, which is fixed inside the outer casing 31 by a fixing bracket 361. A motor 371 is fixed inside the guide cone 36, and a bearing 373 is installed at the bottom of the guide cone 36. The motor 371 is connected to a drive shaft 372, and a grinding pestle 375 is connected to the lower part of the drive shaft 372. Two fixing seats 374 are provided inside the grinding pestle 375. The drive shaft 372 is rotatably inserted into the bearing 373 and fixed in the fixing seat 374. The bottom of the grinding pestle 375 is concave in the middle and forms a ring-shaped grinding section 376 around its perimeter. Two material dropping points are provided on the outer wall of the grinding section 376. A notch 377; a material receiving platform 38 is provided below the grinding pestle 376. The side wall of the material receiving platform 38 is shaped like a bucket. The top of the material receiving platform 38 is fixed to the inner wall of the outer shell 31. The center of the bottom of the material receiving platform 38 is a raised truncated cone 382, ​​and the surrounding area is a ring-shaped grinding trough 381. The grinding trough 381 is a screen with a mesh diameter of 1~4mm. The resulting circulating desulfurizing agent is neither too small, which would cause the same disadvantage as dust, nor too large, which would prevent it from being carried upward by the airflow in the desulfurization tower. The size of the grinding trough 381 is adapted to the size of the grinding section 376. A collection hopper 39 is provided below the material receiving platform 38.

[0032] like Figure 1As shown, the circulating desulfurizing agent conveying device 40 includes a material chamber 41. The top of the material chamber 41 has a feed inlet located directly below the discharge port of the collecting hopper 39. The end of the material chamber 41 has a discharge port connected to the desulfurization tower 10. The end of the material chamber 41 near the granulation device 30 slopes downwards towards the end near the desulfurization tower 40 at an angle of 20°. A gas chamber 42 is provided below the material chamber 41. The air inlet of the gas chamber 42 is connected to a compressed air pipeline. A fluidized bed is provided between the material chamber 41 and the gas chamber 42.

[0033] The working principle of this system for desulfurizing defluorinated electrolytic aluminum flue gas is as follows:

[0034] The defluorinated electrolytic flue gas is introduced into the desulfurization tower 10, and the desulfurizing agent (sodium hydroxide) is introduced into the desulfurization tower 10 at the same time. Under negative pressure, the flue gas and the desulfurizing agent come into contact with the water mist sprayed by the high-pressure water gun 11 and react to achieve flue gas desulfurization. The desulfurized flue gas in the desulfurization tower, carrying the dust containing the desulfurizing agent, is transported to the dust collector 20. After the flue gas and dust are separated, the desulfurized and dust-removed gas is discharged into the air, and the dust containing the desulfurizing agent enters the granulation device 30 through the ash hopper.

[0035] Inside the granulation device 30, dust containing desulfurizing agent first falls onto the buffer plate 32 and slowly descends along it. During this descent, atomizing nozzles 33 spray water mist to humidify the dust containing desulfurizing agent, making it moist as it continues to fall. The water volume is controlled by a solenoid valve 331 and a flow meter 332 during the humidification process. The wet material continues to fall, and the guide plate 34, being bucket-shaped, allows the wet material to fall onto the first pair of rollers 351. Because the water volume is controlled, the wet material is only humidified by the water mist and does not clump together, thus it does not remain on the guide plate 34. The first pair of rollers 351 performs the first round of compression on the wet material. The second pair of rollers 353 further compresses the wet material after compression by the first pair of rollers 351, and also compresses the wet material that has not been compressed by the first pair of rollers 351, making it into flakes. Simultaneously, a scraper scrapes off any remaining wet material from the rollers of the second pair of rollers 353. The sheet-like wet material falls along the guide cone 36 to the side wall of the receiving platform 38, and falls onto the grinding trough 381 along the dropping notch 377 of the grinding section 376. The motor 371 drives the transmission shaft 372 to rotate the grinding pestle 375. The grinding section 376 pushes and crushes the sheet-like wet material from the grinding trough 381. After passing through the grinding trough 381, the sheet-like wet material becomes granular circulating desulfurizing agent, which is conveyed downward along the collection hopper 39 out of the bottom of the outer shell 31 and enters the circulating desulfurizing agent conveying device 40.

[0036] After compressed air is introduced into the air chamber 42, it rises through the boiling plate into the material chamber 41, pushing the circulating desulfurizing agent into the desulfurization tower 10. There, it desulfurizes together with the newly added desulfurizing agent, and then enters the dust collector 20, the granulation device 30, and the circulating desulfurizing agent conveying device 40, and so on. After running for a period of time, the circulating desulfurizing agent is sampled. If the calcium content of the circulating desulfurizing agent is found to be less than 5%, it is treated as waste and no longer enters the desulfurization tower 10.

[0037] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A desulfurization flue gas recycling system, comprising a desulfurization tower and a dust collector, wherein the outlet of the desulfurization tower is connected to the inlet of the dust collector, characterized in that, The desulfurization tower is equipped with several high-pressure water guns, which are equidistantly arranged along the inner wall of the desulfurization tower. It also includes a granulation device and a circulating desulfurizing agent conveying device; the circulating desulfurizing agent conveying device includes a material chamber, the end of the material chamber near the granulation device is inclined from top to bottom towards the end near the desulfurization tower; a gas chamber is provided below the material chamber, and the air inlet of the gas chamber is connected to a compressed air pipeline; a fluidized bed is provided between the material chamber and the gas chamber. The ash outlet of the dust collector's ash hopper is connected to the feed inlet of the granulation device, the discharge outlet of the granulation device's collection hopper is connected to the feed inlet of the material chamber, and the discharge outlet of the material chamber is connected to the circulating desulfurizing agent inlet of the desulfurization tower.

2. The desulfurization flue gas recycling system according to claim 1, characterized in that, The granulation device is located directly below the dust collector's ash hopper.

3. The desulfurization flue gas recycling system according to claim 1, characterized in that, The granulation device includes a shell, and the shell includes, from top to bottom, a humidification zone, an extrusion zone, and a granulation zone; The humidification zone is equipped with several atomizing nozzles, and a guide plate is provided below the atomizing nozzles. The guide plate is shaped like a bucket. The extrusion zone includes, from top to bottom, a first pair of rollers and several sets of second pairs of rollers, the roller spacing of the second pairs of rollers being smaller than the roller spacing of the first pairs of rollers; the material discharge port of the guide plate is located directly above the first pairs of rollers; The granulation zone includes a guide cone, which is fixed inside the outer casing by a fixing frame. A motor is fixed inside the guide cone, and a bearing is installed at the bottom of the guide cone. The motor is connected to a drive shaft, and a grinding pestle is connected to the lower part of the drive shaft. At least one fixing seat is provided inside the grinding pestle, and the drive shaft is rotatably inserted into the bearing and fixed in the fixing seat. The bottom of the grinding pestle is concave upwards in the middle, forming a ring-shaped grinding section around its perimeter. At least one material discharge notch is provided on the outer wall of the grinding section. A material receiving platform is provided below the grinding pestle. The side walls of the material receiving platform are bucket-shaped, and the top of the material receiving platform is fixed to the inner wall of the outer casing. The bottom of the material receiving platform has a raised frustum at its center and a ring-shaped grinding groove around its perimeter. The grinding groove is a screen, and the size of the grinding groove is adapted to the size of the grinding section. A collection hopper is provided below the material receiving platform.

4. The desulfurization flue gas recycling system according to claim 3, characterized in that, The humidification zone is equipped with several buffer plates, which are inclined from top to bottom. The upper part of the buffer plate is fixed to the inner wall of the outer shell, and the buffer plate is located above the atomizing nozzle.

5. The desulfurization flue gas recycling system according to claim 3, characterized in that, The water inlet of the atomizing nozzle is connected to a water inlet pipeline, and a solenoid valve and a flow meter are installed on the water inlet pipeline.

6. The desulfurization flue gas recycling system according to claim 3, characterized in that, The first pair of rollers has several roller teeth on its roller skin.

7. A desulfurization flue gas recycling system according to claim 3, characterized in that, A scraper is provided below each pair of second rollers, and the top of the scraper is in contact with the roller skin of the second pair of rollers; the scraper is mounted on a scraper shaft, which is fixed to the inner wall of the outer casing.

8. The desulfurization flue gas recycling system according to claim 1, characterized in that, The inclination angle of the material chamber is 10~45°.

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