Aluminum electrolysis flue gas wet desulfurization system
Patent Information
- Application Number
- CN202522007320.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-18
- Publication Date
- 2026-09-01
- Estimated Expiration
- 2035-09-18
AI Technical Summary
石灰石浆液制备时，石灰石粉（CaCO3）在水中溶解度低，若溶解不充分，会导致浆液中有效Ca2+不足，需要多投加石灰石才能保证效果，造成浪费；
1、本实用新型在浆液池布置盘型喷气组件和搅拌叶片，在浆液进入脱硫塔前，提前进行氧化和结晶预处理，盘型喷气组件提前通入氧气，让浆液中提前形成氧化氛围，当后续进入脱硫塔与SO2反应生成CaSO3时，能更快被氧化为CaSO4，因为O2已充足，无需等待塔内氧化，CaSO4的溶解度远低于CaSO3，更容易结晶析出，而结晶会拉动反应正向进行，减少浆液中未反应的CaCO3残留。
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Figure CN224699954U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wet system technology, and in particular to a wet desulfurization system for aluminum electrolysis flue gas. Background Technology
[0002] In aluminum electrolysis production, flue gas recovery and purification are crucial, as they affect the protection of employees and the surrounding environment of the workshop. The flue gas generated by the electrolytic cell in aluminum electrolysis production contains harmful substances such as sulfur dioxide and hydrogen fluoride. The sulfur dioxide in the flue gas enters the absorption tower and reacts with limestone slurry to produce sulfites, thereby reducing the sulfur dioxide in the flue gas by 98%. The use of limestone slurry is crucial for reducing sulfur dioxide. When the limestone slurry can fully react and crystallize, the amount of limestone powder used can be effectively reduced, thus improving the sulfur dioxide purification effect. Limestone powder plays a vital role in wet desulfurization. However, the core reaction of wet desulfurization is the reaction between limestone slurry (CaCO3) and SO2 in the flue gas, ultimately producing gypsum (CaSO4·2H2O) crystals. But there are two key limitations in the actual reaction: During the preparation of limestone slurry, limestone powder (CaCO3) has low solubility in water. If dissolution is insufficient, it will lead to a decrease in the available Ca in the slurry. 2+ The drawback is that more limestone needs to be added to ensure the effect, resulting in waste. The intermediate product calcium sulfite (CaSO3) generated in the reaction has high solubility. If the oxidation (to CaSO4) and crystallization rate are slow, it will accumulate in the slurry, hindering the further reaction between CaCO3 and SO2, and may also lead to scaling in the desulfurization tower. Therefore, this utility model proposes a wet desulfurization system for aluminum electrolysis flue gas to solve the problems existing in the prior art. Utility Model Content
[0003] To address the aforementioned problems, this invention proposes a wet desulfurization system for aluminum electrolysis flue gas. This system arranges disc-shaped jetting components and stirring blades in the slurry tank. Before the slurry enters the desulfurization tower, it undergoes pre-treatment for oxidation and crystallization. Oxygen is introduced into the disc-shaped jetting components in advance, creating an oxidizing atmosphere in the slurry. When the slurry subsequently enters the desulfurization tower and reacts with SO2 to generate CaSO3, it can be oxidized to CaSO4 more quickly. Because O2 is already sufficient, there is no need to wait for oxidation within the tower. The solubility of CaSO4 is much lower than that of CaSO3, making it easier to crystallize and precipitate. Crystallization promotes the forward reaction, reducing unreacted CaCO3 residue in the slurry.
[0004] To achieve the purpose of this utility model, the utility model is implemented through the following technical solution: a wet desulfurization system for aluminum electrolysis flue gas, including a slurry tank and a support. The support is located above the slurry tank, and a drive component is provided at the middle of the support. The slurry tank is equipped with stirring blades inside. The drive component is used to drive the stirring blades to rise, fall, and rotate. A limestone powder hopper is provided on one side of the support, and a feeding pipe is connected between the limestone powder hopper and the inside of the slurry tank. A water pipe is connected to one side of the top of the slurry tank. The bottom of the slurry tank is equipped with a disc-shaped jet assembly, and a compressed air pipe is connected to the lower side of one side of the slurry tank. The compressed air pipe is connected to the disc-shaped jet assembly.
[0005] A further improvement is that the disc-shaped jet assembly includes a coil and a connecting pipe, the coil is provided in multiple sets, the compressed air pipe is connected to the outermost coil, the multiple sets of coils are connected to each other through the connecting pipe, and the coil is provided with a nozzle, and the nozzle is provided in multiple sets.
[0006] A further improvement is that the feeding pipeline includes a conveying pipe and a first valve, the conveying pipe connecting the bottom of the limestone powder hopper and the top of the slurry tank, and the first valve being located on the conveying pipe.
[0007] A further improvement is that the drive assembly includes a geared motor and an adjusting cylinder. The geared motor is located at the middle of the top of the support, and the adjusting cylinder is located at the middle of the upper inner side of the support. A rotating cylinder is movably provided inside the adjusting cylinder, and a rotating shaft is provided below the rotating cylinder. The rotating shaft extends movably into the interior of the slurry tank and is connected to the stirring blades.
[0008] A further improvement is that: the inner wall of the adjusting cylinder is provided with an arc-shaped groove, the outer side of the rotating cylinder is provided with a protrusion that matches the arc-shaped groove, and the output end of the reduction motor is provided with a rectangular rod, which is inserted into the interior of the rotating cylinder and slidably adapted.
[0009] A further improvement is that a slurry discharge pipe is provided on one side of the bottom of the slurry tank, and a second valve is provided on the slurry discharge pipe.
[0010] The beneficial effects of this utility model are as follows: 1. This utility model arranges a disc-shaped jet assembly and stirring blades in the slurry tank to perform oxidation and crystallization pretreatment before the slurry enters the desulfurization tower. The disc-shaped jet assembly introduces oxygen in advance to create an oxidation atmosphere in the slurry. When the slurry enters the desulfurization tower and reacts with SO2 to generate CaSO3, it can be oxidized to CaSO4 more quickly. Because O2 is sufficient, there is no need to wait for oxidation in the tower. The solubility of CaSO4 is much lower than that of CaSO3, making it easier to crystallize and precipitate. Crystallization will drive the reaction forward and reduce the amount of unreacted CaCO3 residue in the slurry.
[0011] 2. This utility model uses a drive assembly to drive the stirring blades to rise and rotate, which can prevent limestone powder from settling and make the slurry uniform. When compressed air is sprayed from the bottom, a large number of bubbles will be formed, which will further agitate the slurry, which is equivalent to double stirring. This allows the limestone powder to come into more full contact with water, reduces agglomeration, and increases the dissolution rate of CaCO3. The turbulence generated when the bubbles break can make the slurry more uniform, avoid local concentrations that are too high or too low, and provide a stable environment for subsequent oxidation and crystallization.
[0012] 3. In this invention, the pre-oxidation and thorough stirring in the slurry tank will promote the early formation of a small amount of tiny CaSO4 crystals in the slurry. When this seed slurry enters the desulfurization tower, the newly generated CaSO4 will preferentially grow on the existing seed crystals instead of randomly settling on the tower wall, thus accelerating the crystallization rate and enabling faster separation of the reaction product (CaSO4) from the slurry. This promotes the continuous dissolution of CaCO3 and its reaction with SO2, improving the overall reaction efficiency. At the same time, because the limestone powder dissolves and reacts more fully, it does not need to be added in excess to achieve the desired effect, ultimately achieving the goal of improving desulfurization efficiency and reducing limestone usage. Attached Figure Description
[0013] Figure 1 This is the front view of the present invention; Figure 2 This is a schematic diagram of the stirring blade of this utility model; Figure 3 This is a schematic diagram of the disc-shaped jet assembly of this utility model; Figure 4 This is a schematic diagram of the drive component of this utility model.
[0014] The components include: 1. Slurry tank; 2. Support frame; 3. Agitator blades; 4. Limestone powder hopper; 5. Water pipe; 6. Compressed air pipe; 7. Coil; 8. Connecting pipe; 9. Nozzle; 10. Material conveying pipe; 11. First valve; 12. Gear motor; 13. Adjusting cylinder; 14. Rotary cylinder; 15. Rotating shaft; 16. Arc groove; 17. Protrusion; 18. Rectangular rod; 19. Slurry discharge pipe; 20. Second valve. Detailed Implementation
[0015] To deepen the understanding of this utility model, the following detailed description will be provided in conjunction with embodiments. These embodiments are only used to explain this utility model and do not constitute a limitation on the scope of protection of this utility model.
[0016] Example 1 according to Figure 1 , 2As shown in Figures 3 and 4, this embodiment proposes a wet desulfurization system for aluminum electrolysis flue gas, including a slurry tank 1 and a support 2. The support 2 is located above the slurry tank 1, and a drive assembly is provided at the middle of the support 2. The slurry tank 1 is equipped with stirring blades 3 inside, and the drive assembly is used to drive the stirring blades 3 to rise, fall, and rotate. A limestone powder hopper 4 is provided on one side of the support 2, and a feeding pipe is connected between the limestone powder hopper 4 and the inside of the slurry tank 1. A water pipe 5 is connected to one side of the top of the slurry tank 1. The bottom of the slurry tank 1 is equipped with a disc-shaped jet assembly, and a compressed air pipe 6 is connected to the lower side of one side of the slurry tank 1. The compressed air pipe 6 is connected to the disc-shaped jet assembly. In operation, a disc-shaped jet assembly and stirring blades are arranged in the slurry tank 1. Before the slurry enters the desulfurization tower, it undergoes pre-treatment for oxidation and crystallization. The disc-shaped jet assembly introduces oxygen in advance to create an oxidizing atmosphere in the slurry. When the slurry enters the desulfurization tower and reacts with SO2 to generate CaSO3, it can be oxidized to CaSO4 more quickly because O2 is already sufficient and there is no need to wait for oxidation in the tower. The solubility of CaSO4 is much lower than that of CaSO3, making it easier to crystallize and precipitate. Crystallization will drive the reaction forward and reduce the amount of unreacted CaCO3 residue in the slurry. The stirring blades 3 are driven to rise and rotate by the drive assembly to prevent limestone powder from settling and to make the slurry uniform. When compressed air is sprayed from the bottom, a large number of bubbles are formed, which further agitates the slurry, which is equivalent to double stirring. This allows the limestone powder to come into more complete contact with water, reduces agglomeration, and increases the dissolution rate of CaCO3. The turbulence generated when the bubbles break makes the slurry more uniform and avoids local concentrations that are too high or too low, providing a stable environment for subsequent oxidation and crystallization.
[0017] The disc-shaped jet assembly includes a coil 7 and a connecting pipe 8. Multiple sets of coil 7 are provided. The compressed air pipe 6 connects to the outermost coil 7, and the multiple sets of coil 7 are connected by the connecting pipes 8. Multiple sets of nozzles 9 are provided on each coil 7. In use, compressed air is introduced through the compressed air pipe 6, entering the multiple sets of coil 7 and connecting pipes 8, and is then evenly and widely sprayed from the multiple sets of nozzles 9. When the compressed air is sprayed from the bottom, it forms a large number of bubbles, further agitating the slurry, equivalent to double stirring. This allows for more thorough contact between limestone powder and water, reducing agglomeration and increasing the dissolution rate of CaCO3. The turbulence generated when the bubbles break makes the slurry more uniform, avoiding excessively high or low local concentrations, and providing a stable environment for subsequent oxidation and crystallization.
[0018] The feeding pipeline includes a conveying pipe 10 and a first valve 11. The conveying pipe 10 connects the bottom of the limestone powder hopper 4 and the top of the slurry tank 1, and the first valve 11 is located on the conveying pipe 10. In use, the first valve 11 is opened, and the limestone powder in the limestone powder hopper 4 is supplied to the slurry tank 1 through the conveying pipe 10 to prepare limestone slurry.
[0019] The drive assembly includes a geared motor 12 and an adjusting cylinder 13. The geared motor 12 is located at the middle of the top of the support 2, and the adjusting cylinder 13 is located at the middle of the upper inner side of the support 2. A rotating cylinder 14 is movably mounted inside the adjusting cylinder 13, and a rotating shaft 15 is located below the rotating cylinder 14. The rotating shaft 15 extends movably into the interior of the slurry tank 1 and connects to the stirring blades 3. An arc-shaped groove 16 is provided on the inner wall of the adjusting cylinder 13, and a protrusion 17 that matches the arc-shaped groove 16 is provided on the outer side of the rotating cylinder 14. A rectangular rod 18 is provided at the output end of the geared motor 12, and the rectangular rod 18 is inserted into the interior of the rotating cylinder 14 and slidably adapted. In operation, the geared motor 12 drives the rectangular rod 18 to rotate, which in turn drives the rotating drum 14 to rotate. During the rotation of the rotating drum 14, the convex point 17 and the arc groove 16 are matched to move up and down, which drives the rotating shaft 15 and the stirring blades to rotate and move up and down, thus carrying out full-range stirring. The pre-oxidation and full stirring will promote the early formation of a small amount of CaSO4 micro crystals in the slurry. When this seed slurry enters the desulfurization tower, the newly generated CaSO4 will preferentially grow on the existing seed crystals instead of randomly settling on the tower wall. The crystallization speed is accelerated, and the reaction product (CaSO4) can be separated from the slurry more quickly, which promotes the continuous dissolution of CaCO3 and its reaction with SO2, thereby improving the overall reaction efficiency.
[0020] Example 2 according to Figure 1 , 2 As shown in Figures 3 and 4, this embodiment proposes a wet desulfurization system for aluminum electrolysis flue gas, including a slurry tank 1 and a support 2. The support 2 is located above the slurry tank 1, and a drive assembly is provided at the middle of the support 2. The slurry tank 1 is equipped with stirring blades 3 inside, and the drive assembly is used to drive the stirring blades 3 to rise, fall, and rotate. A limestone powder hopper 4 is provided on one side of the support 2, and a feeding pipe is connected between the limestone powder hopper 4 and the inside of the slurry tank 1. A water pipe 5 is connected to one side of the top of the slurry tank 1. The bottom of the slurry tank 1 is equipped with a disc-shaped jet assembly, and a compressed air pipe 6 is connected to the lower side of one side of the slurry tank 1. The compressed air pipe 6 is connected to the disc-shaped jet assembly. In operation, a disc-shaped jet assembly and stirring blades are arranged in the slurry tank 1. Before the slurry enters the desulfurization tower, it undergoes pre-treatment for oxidation and crystallization. The disc-shaped jet assembly introduces oxygen in advance to create an oxidizing atmosphere in the slurry. When the slurry enters the desulfurization tower and reacts with SO2 to generate CaSO3, it can be oxidized to CaSO4 more quickly because O2 is already sufficient and there is no need to wait for oxidation in the tower. The solubility of CaSO4 is much lower than that of CaSO3, making it easier to crystallize and precipitate. Crystallization will drive the reaction forward and reduce the amount of unreacted CaCO3 residue in the slurry. The stirring blades 3 are driven to rise and rotate by the drive assembly to prevent limestone powder from settling and to make the slurry uniform. When compressed air is sprayed from the bottom, a large number of bubbles are formed, which further agitates the slurry, which is equivalent to double stirring. This allows the limestone powder to come into more complete contact with water, reduces agglomeration, and increases the dissolution rate of CaCO3. The turbulence generated when the bubbles break makes the slurry more uniform and avoids local concentrations that are too high or too low, providing a stable environment for subsequent oxidation and crystallization.
[0021] A slurry discharge pipe 19 is provided on one side of the bottom of the slurry tank 1, and a second valve 20 is provided on the slurry discharge pipe 19. After the limestone slurry inside the slurry tank 1 is prepared, the pre-oxidation and sufficient stirring will promote the early formation of a small amount of CaSO4 micro crystals in the slurry. After opening the second valve 20, this seed-containing slurry is introduced into the desulfurization tower through the slurry discharge pipe 19. The newly generated CaSO4 will preferentially grow on the existing seed crystals instead of randomly settling on the tower wall, thus accelerating the crystallization rate and separating the reaction product (CaSO4) from the slurry more quickly. This promotes the continuous dissolution of CaCO3 and its reaction with SO2, improving the overall reaction efficiency. At the same time, because the limestone powder dissolves and reacts more fully, it can achieve the desired effect without excessive addition, ultimately achieving the goal of improving desulfurization efficiency and reducing limestone consumption.
[0022] This aluminum electrolysis flue gas wet desulfurization system arranges disc-shaped jet components and stirring blades in the slurry tank 1. Before the slurry enters the desulfurization tower, it undergoes pre-treatment for oxidation and crystallization. The disc-shaped jet components introduce oxygen in advance, creating an oxidizing atmosphere in the slurry. When the slurry subsequently enters the desulfurization tower and reacts with SO2 to produce CaSO3, it can be oxidized to CaSO4 more quickly because O2 is already sufficient, eliminating the need to wait for oxidation within the tower. The solubility of CaSO4 is much lower than that of CaSO3, making it easier to crystallize and precipitate. Crystallization drives the reaction forward, reducing unreacted CaCO3 residue in the slurry. Furthermore, the stirring blades 3, driven by the drive component, rise and rotate, preventing limestone powder from settling and ensuring a uniform slurry. When compressed air is sprayed from the bottom, it forms a large number of bubbles, further agitating the slurry, effectively creating a double stirring effect. This allows for more thorough contact between limestone powder and water, reducing agglomeration and increasing the dissolution rate of CaCO3. The turbulence generated when the bubbles break further homogenizes the slurry, preventing localized high or low concentrations and providing a stable environment for subsequent oxidation and crystallization. Meanwhile, in slurry tank 1, the pre-oxidation and thorough stirring will promote the early formation of a small amount of CaSO4 microcrystals in the slurry. When this seed-containing slurry enters the desulfurization tower, the newly generated CaSO4 will preferentially grow on the existing seed crystals instead of randomly settling on the tower wall, thus accelerating the crystallization rate and enabling faster separation of the reaction product (CaSO4) from the slurry. This promotes the continuous dissolution of CaCO3 and its reaction with SO2, improving the overall reaction efficiency. At the same time, because the limestone powder dissolves and reacts more fully, it does not need to be added in excess to achieve the desired effect, ultimately achieving the goal of improving desulfurization efficiency and reducing limestone usage.
[0023] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A wet desulfurization system for aluminum electrolysis flue gas, comprising a slurry tank (1) and a support frame (2), characterized in that: The support (2) is located above the slurry tank (1), and a drive assembly is provided at the middle of the support (2). The slurry tank (1) is provided with stirring blades (3). The drive assembly is used to drive the stirring blades (3) to rise and rotate. A limestone powder hopper (4) is provided on one side of the support (2), and a feeding pipe is connected between the limestone powder hopper (4) and the inside of the slurry tank (1). A water pipe (5) is connected to one side of the top of the slurry tank (1). The bottom of the slurry tank (1) is provided with a disc-shaped jet assembly, and a compressed air pipe (6) is connected to the lower side of one side of the slurry tank (1). The compressed air pipe (6) is connected to the disc-shaped jet assembly.
2. The wet desulfurization system for aluminum electrolysis flue gas according to claim 1, characterized in that: The disc-shaped jet assembly includes a coil (7) and a connecting pipe (8). The coil (7) is provided in multiple sets. The compressed air pipe (6) is connected to the outermost coil (7). The multiple sets of coils (7) are connected to each other through the connecting pipe (8). The coil (7) is provided with nozzles (9), and the nozzles (9) are provided in multiple sets.
3. The wet desulfurization system for aluminum electrolysis flue gas according to claim 1, characterized in that: The feeding pipeline includes a conveying pipe (10) and a first valve (11). The conveying pipe (10) connects the bottom of the limestone powder hopper (4) and the top of the slurry tank (1). The first valve (11) is located on the conveying pipe (10).
4. The wet desulfurization system for aluminum electrolysis flue gas according to claim 1, characterized in that: The drive assembly includes a geared motor (12) and an adjusting cylinder (13). The geared motor (12) is located at the middle of the top of the support (2). The adjusting cylinder (13) is located at the middle of the inner side of the support (2). A rotating cylinder (14) is movably provided inside the adjusting cylinder (13), and a rotating shaft (15) is provided below the rotating cylinder (14). The rotating shaft (15) extends movably into the interior of the slurry tank (1) and is connected to the stirring blade (3).
5. The wet desulfurization system for aluminum electrolysis flue gas according to claim 4, characterized in that: The inner wall of the adjusting cylinder (13) is provided with an arc groove (16), and the outer side of the rotating cylinder (14) is provided with a protrusion (17) that matches the arc groove (16). The output end of the reduction motor (12) is provided with a rectangular rod (18), which is inserted into the interior of the rotating cylinder (14) and slidably adapted.
6. The wet desulfurization system for aluminum electrolysis flue gas according to any one of claims 1-5, characterized in that: The bottom of the slurry tank (1) is provided with a slurry discharge pipe (19) on one side, and a second valve (20) is provided on the slurry discharge pipe (19).