Single-tower two-stage double-absorbent wet desulphurization system

Abstract

The invention discloses a single-tower two-stage double-absorbent wet desulphurization system, and relates to the technical field of flue gas purification, the single-tower two-stage double-absorbent wet desulphurization system comprises a tower body, the side wall close to the bottom of the tower body is provided with a flue gas inlet, and the top of the tower body is provided with a flue gas outlet; the first spraying layer and the second spraying layer are distributed in the tower body at intervals up and down; the flow guide plate is arranged in the tower body and is positioned between the first spraying layer and the second spraying layer; the mounting pipe bodies are fixed on the top surface of the flow guide plate at intervals; each hollow gas distribution pipe is vertically arranged, the bottom of each hollow gas distribution pipe penetrates through the flow guide plate and is communicated with an inner cavity of a mounting pipe body, and the top of each hollow gas distribution pipe is sealed. Gas redistribution is formed between two stages of spraying layers through cooperation of the flow guide plates and the lateral gas outlet gas distribution pipes, so that washing channels for slurry with different pH values are formed; the absorption of most SO2 is completed at a low pH value, and the deep desulfurization is completed at a high pH value slurry, so that the desulfurization efficiency and the utilization rate of an absorbent are improved.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification technology, specifically to a single-tower, two-stage, dual-absorbent wet desulfurization system. Background Technology

[0002] Wet limestone-gypsum desulfurization is the most widely used flue gas purification technology in coal-fired power plants and other fields. Its typical equipment is a spray absorption tower, in which flue gas flows from bottom to top and comes into countercurrent contact with limestone slurry sprayed from top to bottom, resulting in a neutralization reaction to remove sulfur dioxide.

[0003] In traditional single-stage spray desulfurization processes, the pH value of the desulfurization slurry is a key parameter affecting absorption and oxidation efficiency. Studies have shown that a higher pH value is beneficial for the gas-liquid absorption of SO2 but detrimental to the dissolution of limestone and the oxidation of gypsum; while a lower pH value is beneficial for the oxidation reaction, it significantly reduces the slurry's SO2 absorption capacity. Therefore, to balance absorption and oxidation efficiency, industrial applications typically control the desulfurization slurry under slightly acidic conditions (pH approximately 5.0–5.8). Under these conditions, the slurry's SO2 absorption capacity is limited, and the SO2 gas-phase equilibrium concentration is relatively high.

[0004] With increasingly stringent environmental protection requirements, coal-fired power units must meet ultra-low emission or even ultra-ultra-low emission standards. Traditional single-stage spraying processes, under acidic slurry conditions, are limited by the SO2 gas-liquid equilibrium concentration, making it difficult to further reduce outlet emission concentrations by improving single-stage absorption efficiency. To achieve emission standards, current technologies can only enhance gas-liquid contact by significantly increasing the liquid-to-gas ratio, i.e., increasing spray density and circulating slurry volume. However, this approach significantly increases the energy consumption of the slurry circulation pump and system operating costs, and suffers from diminishing marginal returns. Summary of the Invention

[0005] The purpose of this invention is to provide a single-tower, two-stage, dual-absorbent wet desulfurization system to solve the problems of insufficient SO2 absorption capacity, excessive reliance on large liquid-to-gas ratio, and high energy consumption in traditional single-stage wet desulfurization processes due to the limitation of slurry pH value in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a single-tower, two-stage, dual-absorbent wet desulfurization system, comprising a tower body, wherein a flue gas inlet is provided on the side wall near the bottom and a flue gas outlet is provided at the top;

[0007] The first spray layer and the second spray layer are distributed vertically and alternately inside the tower body;

[0008] A guide plate is disposed inside the tower body and located between the first spray layer and the second spray layer;

[0009] The air distribution mechanism is installed on the air distribution plate and includes multiple mounting tubes fixed at intervals to the top surface of the air distribution plate, multiple hollow air distribution tubes that are vertically arranged and whose bottoms pass through the air distribution plate and communicate with the interior of the mounting tubes, multiple air outlet tubes that are circumferentially distributed on the side walls of the hollow air distribution tubes and communicate with the interior, and a conical cover plate fixedly installed on the top of the hollow air distribution tubes.

[0010] The first slurry circulation mechanism includes a first slurry tank containing a strong alkali absorbent and a first conveying pipeline. One end of the first conveying pipeline is connected to the first spray layer, and the other end is connected to the first slurry tank.

[0011] The second slurry circulation mechanism includes a second slurry tank containing limestone slurry and a second conveying pipeline. One end of the second conveying pipeline is connected to the second spray layer, and the other end is connected to the second slurry tank.

[0012] Furthermore, the first slurry tank contains a strong alkali absorbent, the second slurry tank contains limestone slurry, and both the first and second conveying pipelines are equipped with conveying pumps.

[0013] Furthermore, a flue gas detector is installed at the flue gas outlet of the tower body, and a gypsum discharge pipe is also provided on the side wall of the tower body.

[0014] Furthermore, the top surface of the guide plate is a conical surface that gradually decreases from the center of the tower body towards the tower wall, and the guide plate is provided with an installation hole for the hollow gas distribution pipe to pass through, and the installation pipe body is a hollow structure with an open bottom.

[0015] Furthermore, the hollow air distribution pipe is provided with a threaded portion, which is detachably connected to the mounting pipe body. The air outlet pipes are distributed in at least two layers along the axial direction of the hollow air distribution pipe, and the axis of each layer of air outlet pipes is inclined upward relative to the horizontal direction.

[0016] Furthermore, the hollow gas distribution pipe is also provided with a baffle plate, which is located between the uppermost gas outlet pipe and the conical cover plate. The baffle plate is installed on the outside of the hollow gas distribution pipe through a hinge shaft and is configured to swing or vibrate under the impact of the flue gas flow from the gas outlet pipe.

[0017] Furthermore, the surface of the spoiler facing the airflow is an arc-shaped guide surface, and its surface facing away from the airflow is provided with spaced protruding spoiler ribs.

[0018] Furthermore, it also includes a slurry collection plate. The inner wall of the tower body is provided with annularly distributed support blocks. The bottom of the slurry collection plate is fixedly connected to an installation block. The bottom of the installation block is provided with an installation groove that cooperates with the support block. The bottom of the slurry collection plate is provided with a receiving hole. The vertical cross-section of the receiving hole is concave. The outer wall of the guide plate is provided with a sealing rubber layer, which seals the guide plate in the receiving hole.

[0019] Furthermore, the top of the slurry collection plate is provided with annularly distributed slurry collection tanks, the bottom of the slurry collection tanks is an arc-shaped surface, the bottom of the slurry collection plate is symmetrically provided with guide pipes communicating with the slurry collection tanks, and the interior of the tower body and above the guide plate is also provided with a sludge removal component.

[0020] Furthermore, the dredging assembly consists of a positioning rod, a driving component, a rotating plate, and a dredging plate. The positioning rod is an inverted T-shape, and the outer wall of the tower body is provided with a locking component. The locking component passes through the tower body and locks into the T-shaped transverse section of the positioning rod. The driving component is connected to an external power supply and installed at the bottom of the T-shaped vertical section of the positioning rod. The rotating plate is connected to the output shaft of the driving component through a coupling. The dredging plate is symmetrically fixedly connected to the bottom of the rotating plate, and the bottom surface of the dredging plate is movably fitted with the collection tank.

[0021] Compared with the prior art, the present invention provides a single-tower, two-stage, dual-absorbent wet desulfurization system.

[0022] 1. By setting up independent first and second slurry circulation mechanisms, strong alkali absorbent and limestone slurry are respectively supplied to the tower body, achieving zoned supply of dual absorbents. Flue gas flows sequentially from bottom to top through the limestone spray zone and the strong alkali spray zone. Initial removal of sulfur dioxide is achieved by the limestone slurry, followed by deep purification by the strong alkali absorbent. This dual-stage absorption structure overcomes the limitation of SO2 absorption capacity based on a single pH value in traditional single-stage spray processes. While maintaining slurry oxidation efficiency, it significantly improves overall desulfurization efficiency, meeting ultra-low emission standards without requiring additional spray layers, effectively reducing equipment modification and installation costs.

[0023] 2. This invention constructs an interstage gas redistribution system by combining a guide plate and a side-exit gas distribution pipe between the two spray layers. This structure can re-uniform the flow of flue gas after the first-stage spray, effectively breaking the possible concentrated upward path of flue gas and forcing it to diffuse towards the tower wall area, thereby increasing its residence time and travel distance in the second-stage spray area. This not only makes the contact between the flue gas and the two-stage alkaline spray more thorough and uniform, improving the utilization efficiency of the absorbent, but also reduces the system pressure drop and energy consumption required to achieve the same desulfurization efficiency by improving the overall flow field.

[0024] 3. This invention further incorporates turbulence-inducing plates and a sludge-removing component. The turbulence-inducing plates oscillate or vibrate under the impact of flue gas flow, breaking up falling slurry droplets and enhancing local turbulence. Simultaneously, they generate a self-cleaning effect on the pipe wall area, preventing blockage of the outlet holes. The sludge-removing component periodically cleans the surface of the guide plate and the collection tank, preventing the slurry from drying and hardening. The synergistic effect of both helps maintain the long-term stability of gas distribution and slurry flow performance, thereby improving the overall operational economy and reliability of the desulfurization system. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of the overall structure of the interstage gas distribution device for a two-stage spray desulfurization tower provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of components such as the guide plate and the mounting pipe provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the baffle component structure provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of components such as the hollow air distribution pipe and the conical cover plate provided in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure of components such as the hollow air distribution tube and the baffle plate provided in an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the internal positioning rod and other components of the tower body provided in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the structure of components such as the slurry collection plate and mounting block provided in an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the internal sludge removal components and slurry collection plate provided in an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Tower body; 2. Flue gas inlet; 3. Flue gas outlet; 4. First spray layer; 5. Second spray layer; 6. Guide plate; 7. Mounting pipe; 8. Hollow gas distribution pipe; 9. Gas outlet pipe; 10. Conical cover plate; 11. First slurry tank; 12. Second slurry tank; 13. First conveying pipeline; 14. Second conveying pipeline; 15. Conveying pump; 16. Flue gas detector; 17. Gypsum discharge pipe; 18. Mounting hole; 19. Threaded part; 20. Baffle plate; 201. Arc-shaped guide surface; 202. Protruding baffle rib; 21. Hinge shaft; 22. Slurry collection plate; 23. Bearing block; 24. Mounting block; 25. Mounting slot; 26. Sealing rubber layer; 27. Liquid collection tank; 28. Guide pipe; 29. ​​Positioning rod; 30. Driving component; 31. Rotating plate; 32. Sludge removal plate; 33. Locking component. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] As attached Figure 1 To be continued Figure 8 As shown:

[0038] Example:

[0039] The present invention provides a single-tower, two-stage, dual-absorbent wet desulfurization system, including a tower body 1, which has a flue gas inlet 2 on its side wall near the bottom and a flue gas outlet 3 on its top.

[0040] The first spray layer 4 and the second spray layer 5 are distributed vertically and alternately inside the tower body 1;

[0041] A guide plate 6 is disposed inside the tower body 1 and located between the first spray layer 4 and the second spray layer 5;

[0042] The air distribution mechanism is installed on the air distribution plate 6 and includes multiple mounting tubes 7 fixed at intervals to the top surface of the air distribution plate 6, multiple hollow air distribution pipes 8 that are vertically arranged and pass through the air distribution plate 6 at the bottom and communicate with the interior of the mounting tubes 7, multiple air outlet pipes 9 that are circumferentially distributed on the side walls of the hollow air distribution pipes 8 and communicate with the interior, and a conical cover plate 10 fixedly installed on the top of the hollow air distribution pipes 8.

[0043] The first slurry circulation mechanism includes a first slurry tank 11 containing a strong alkali absorbent and a first conveying pipeline 13. One end of the first conveying pipeline 13 is connected to the first spray layer 4, and the other end is connected to the first slurry tank 11.

[0044] The second slurry circulation mechanism includes a second slurry tank 12 containing limestone slurry and a second conveying pipeline 14. One end of the second conveying pipeline 14 is connected to the second spray layer 5, and the other end is connected to the second slurry tank 12.

[0045] It should be noted that by setting up independent first and second slurry circulation mechanisms, strong alkali absorbent and limestone slurry are respectively supplied to tower body 1, achieving zoned supply of dual absorbents. Flue gas flows sequentially from bottom to top through the limestone spray zone and the strong alkali spray zone. Initial removal of sulfur dioxide is achieved first by the limestone slurry, followed by deep purification by the strong alkali absorbent. This dual-stage absorption structure overcomes the limitation of SO2 absorption capacity based on a single pH value in traditional single-stage spray processes. While maintaining slurry oxidation efficiency, it significantly improves overall desulfurization efficiency, meeting ultra-low emission standards without requiring additional spray layers, effectively reducing equipment modification and installation costs.

[0046] In this embodiment, a first slurry tank 11 and a second slurry tank 12 are also included. The first spray layer 4 is connected to the first slurry tank 11 through a first conveying pipeline 13, and the second spray layer 5 is connected to the second slurry tank 12 through a second conveying pipeline 14. The first slurry tank 11 contains a strong alkali absorbent, and the second slurry tank 12 contains limestone slurry. Both the first conveying pipeline 13 and the second conveying pipeline 14 are equipped with a conveying pump 15.

[0047] It should be noted that by setting up independent slurry tanks and delivery pipelines, separate and systematic circulation of limestone slurry and strong alkali absorbents (such as calcium hydroxide slurry) is achieved. This two-stage independent slurry circulation method allows the first and second stage spray layers to operate under optimal pH values ​​and reaction conditions. For example, the first stage performs deep purification at a higher pH, while the second stage can efficiently absorb large amounts of sulfur dioxide and promote limestone dissolution at a lower pH, ensuring that the final emissions meet standards. The independent circulation system also facilitates the separate control and recovery of by-products of different qualities (such as gypsum), improving the flexibility and economy of system operation.

[0048] Additionally, the two-layer spray design, using different absorbents, further avoids the need to add spray layers due to stricter emission standards (such as reducing desulfurization emissions from 35 mg to 20 mg or lower), thereby reducing retrofit costs and energy consumption, and better meeting subsequent emission standards for desulfurization.

[0049] In this embodiment: a flue gas detector 16 is provided at the flue gas outlet 3 of the tower body 1, and a gypsum discharge pipe 17 is also provided on the side wall of the tower body 1.

[0050] It should be noted that the flue gas detector 16 is used for online monitoring of the concentration of pollutants such as sulfur dioxide in the purified flue gas, providing real-time feedback for assessing desulfurization efficiency and controlling operating parameters such as spray volume. It is a key component for realizing the automated and intelligent operation of the system. The gypsum discharge pipe 17 is used to continuously or intermittently discharge the gypsum slurry generated by oxidation in the slurry pool at the bottom of the tower and send it to the dewatering system, thereby maintaining the balance of solid content and reactant concentration in the slurry pool and ensuring the continuous and stable progress of the desulfurization reaction.

[0051] In this embodiment: the top surface of the guide plate 6 is a conical surface that gradually decreases from the center of the tower body 1 towards the tower wall. The guide plate 6 is provided with an installation hole 18 for the hollow gas distribution pipe 8 to pass through. The installation pipe body 7 is a hollow structure with an open bottom.

[0052] It should be noted that the conical design of the guide plate 6 itself has a guiding function, which can naturally gather the flue gas arriving in this area to the lower two sides where the gas distribution pipe is installed, thus improving the uniformity of flue gas entering the gas distribution pipe. The bottom of the mounting pipe 7 is open and connected to the bottom of the hollow gas distribution pipe 8, so that the flue gas flowing from the conical surface of the guide plate 6 can smoothly enter the mounting pipe 7 and then flow upward into the hollow gas distribution pipe 8, forming a continuous flow channel from gathering to distribution, reducing the flow dead zone.

[0053] In this embodiment: the hollow air distribution pipe 8 is provided with a threaded part 19, which is detachably connected to the mounting pipe body 7 through the threaded part 19. The air outlet pipe 9 is distributed in at least two layers along the axial direction of the hollow air distribution pipe 8, and the axis of each layer of the air outlet pipe 9 is inclined upward relative to the horizontal direction.

[0054] It should be noted that the threaded connection facilitates the installation, replacement, and maintenance of the hollow gas distribution pipe 8. Especially when the outlet pipe 9 or its internal parts become blocked or worn, individual gas distribution pipes can be replaced selectively without large-scale disassembly. The outlet pipe 9 is multi-layered and arranged at an upward angle, allowing the flue gas to be sprayed upwards at a certain angle. This spraying method helps the flue gas continue to move upwards after leaving the pipe opening, forming a stronger reverse contact with the falling spray liquid. Furthermore, the upward angle reduces the possibility of slurry droplets falling directly into the outlet pipe 9 due to gravity, lowering the risk of the pipe opening being blocked by slurry backflow.

[0055] In this embodiment: the hollow air distribution pipe 8 is also provided with a baffle plate 20. The baffle plate 20 is located between the uppermost air outlet pipe 9 and the conical cover plate 10. The baffle plate 20 is installed on the outside of the hollow air distribution pipe 8 through a hinge shaft 21 and is configured to swing or vibrate under the impact of the flue gas flow from the air outlet pipe 9.

[0056] It should be noted that the baffle plate 20 is an important improvement in this embodiment. It is arranged in the path of the flue gas ejection. When high-speed flue gas is ejected from the outlet pipe 9, it directly impacts the baffle plate 20, causing it to oscillate or vibrate at high frequency around the hinge axis 21. This dynamic process has multiple effects: First, the oscillating baffle plate 20 can mechanically break up larger slurry droplets falling from above, increasing the gas-liquid contact area; second, its movement can disturb the surrounding airflow, generating small-scale eddies, enhancing the local turbulence, thereby improving mass transfer efficiency; finally, the continuous movement of the baffle plate 20 produces a "self-cleaning" effect on the pipe wall area it covers, sweeping away slurry particles attempting to adhere to the area above the outlet pipe 9, preventing the formation of a scaling initiation point.

[0057] In this embodiment: the surface of the spoiler 20 facing the airflow is an arc-shaped guide surface 201, and the surface facing away from the airflow is provided with spaced protruding spoiler ribs 202.

[0058] It should be noted that the arc-shaped guide surface 201 can more effectively guide and utilize the force of the flue gas flow, efficiently converting kinetic energy into the oscillating kinetic energy of the baffle 20, ensuring its reliable drive under various operating conditions. The raised baffle ribs 202 on the back further enhance the disturbance and cutting effect of the baffle 20 on the airflow and droplets during oscillation, while increasing the scraping contact area during cleaning, thus improving its comprehensive performance in enhancing mixing and preventing clogging.

[0059] In this embodiment, a slurry collection plate 22 is also included. The inner wall of the tower body 1 is provided with annularly distributed support blocks 23. The bottom of the slurry collection plate 22 is fixedly connected to an installation block 24. The bottom of the installation block 24 is provided with an installation groove 25 that cooperates with the support block 23. The bottom of the slurry collection plate 22 is provided with a receiving hole. The vertical cross-section of the receiving hole is concave. The outer wall of the guide plate 6 is provided with a sealing rubber layer 26. The guide plate 6 is sealed in the receiving hole by the sealing rubber layer 26.

[0060] It should be noted that the slurry collection plate 22 is located above the second spray layer 5 and is mainly used to capture slurry droplets entrained in the flue gas, reduce mist entrainment, protect the subsequent demister, and reduce slurry loss. It is detachable and installable through the slotted engagement of the mounting block 24 and the supporting block 23, facilitating maintenance. The concave receiving hole at the bottom is sealed to the edge of the guide plate 6 via a sealing rubber layer 26. This design allows the guide plate 6 to be stably supported below the liquid collector, while the sealing structure prevents flue gas from short-circuiting through gaps between the edge of the guide plate 6 and the tower wall or collector, ensuring that all flue gas must be redistributed through the gas distribution pipe, thus guaranteeing effective distribution.

[0061] In this embodiment: the top of the slurry collection plate 22 is provided with annularly distributed collection troughs 27, the bottom of the collection troughs 27 is an arc-shaped surface, the bottom of the slurry collection plate 22 is symmetrically provided with guide pipes 28 that communicate with the collection troughs 27, and the inside of the tower body 1 and above the guide plate 6 is also provided with a sludge removal component.

[0062] It should be noted that the annular collection tank 27 is used to collect the slurry collected from the surface of the liquid collector. The arc-shaped bottom surface facilitates the slurry to converge towards the center. The collected slurry is guided back to the slurry pool at the bottom of the tower or a designated collection point through the guide pipe 28, achieving slurry recovery. The sludge removal component installed above the guide plate 6 is mainly designed to remove slurry deposits that may appear on the surface of the guide plate 6. The sludge removal component can periodically or automatically clean the surface of the guide plate 6 to prevent the slurry from drying and hardening, maintaining the smoothness and flow guidance function of the guide plate 6 surface.

[0063] Specifically: the outlet of the guide pipe 28 extends below the liquid level of the slurry pool (not shown in the figure) at the bottom of the tower body 1, so that the collected slurry is returned to the main circulation system.

[0064] In this embodiment: the dredging assembly consists of a positioning rod 29, a driving component 30, a rotating plate 31, and a dredging plate 32. The positioning rod 29 is an inverted T-shape. The outer wall of the tower body 1 is provided with a locking component 33. The locking component 33 passes through the tower body 1 and locks into the T-shaped horizontal section of the positioning rod 29. The driving component 30 is connected to an external power supply and installed at the bottom of the T-shaped vertical section of the positioning rod 29. The rotating plate 31 is connected to the output shaft of the driving component 30 through a coupling. The dredging plate 32 is symmetrically fixedly connected to the bottom of the rotating plate 31. The bottom surface of the dredging plate 32 is movably fitted with the collection tank 27.

[0065] It should be noted that this sludge removal component is a specific implementation. The positioning rod 29 is fixed from outside the tower by the locking member 33, making installation and maintenance relatively convenient and not affecting other components inside the tower. The driving member 30 (such as a motor) drives the rotating plate 31 to rotate, thereby causing the sludge removal plate 32, which is fixed at the bottom of the rotating plate 31, to move along the annular trajectory of the collection tank 27. During the movement, the bottom surface of the sludge removal plate 32 is in contact with the collection tank 27, which can effectively scrape off the sludge or solid particles deposited at the bottom of the tank, prevent the collection tank 27 from being blocked, and ensure that the collected slurry can be smoothly discharged through the guide pipe 28. This mechanical sludge removal method has a reliable structure and a direct sludge removal effect.

[0066] Specifically: the dredging component is located above the guide plate 6, and the movement range of its dredging plate 32 covers the top surface of the guide plate 6, used to scrape off the deposits on the surface of the guide plate 6; at the same time, the dredging plate 32 is also configured to simultaneously clean the deposits in the collection tank 27 when it rotates to the position corresponding to the collection tank 27 of the slurry collection plate 22.

[0067] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A single-tower, two-stage, dual-absorbent wet desulfurization system, characterized in that, include: The tower body (1) has a flue gas inlet (2) on its side wall near the bottom and a flue gas outlet (3) on its top. The first spray layer (4) and the second spray layer (5) are distributed vertically and horizontally inside the tower body (1); A guide plate (6) is disposed inside the tower body (1) and located between the first spray layer (4) and the second spray layer (5); The air distribution mechanism is installed on the air distribution plate (6) and includes multiple mounting tubes (7) fixed at intervals to the top surface of the air distribution plate (6), multiple hollow air distribution pipes (8) that are vertically arranged and pass through the air distribution plate (6) at the bottom and communicate with the interior of the mounting tubes (7), multiple air outlet pipes (9) that are circumferentially distributed on the side wall of the hollow air distribution pipes (8) and communicate with the interior, and a conical cover plate (10) fixedly installed on the top of the hollow air distribution pipes (8). The first slurry circulation mechanism includes a first slurry tank (11) containing a strong alkali absorbent and a first conveying pipeline (13). One end of the first conveying pipeline (13) is connected to the first spray layer (4), and the other end is connected to the first slurry tank (11). The second slurry circulation mechanism includes a second slurry tank (12) containing limestone slurry and a second conveying pipeline (14). One end of the second conveying pipeline (14) is connected to the second spray layer (5), and the other end is connected to the second slurry tank (12).

2. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 1, characterized in that, The first slurry tank (11) contains a strong alkali absorbent, the second slurry tank (12) contains limestone slurry, and both the first conveying pipeline (13) and the second conveying pipeline (14) are equipped with conveying pumps (15).

3. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 2, characterized in that, A flue gas detector (16) is provided at the flue gas outlet (3) of the tower body (1), and a gypsum discharge pipe (17) is also provided on the side wall of the tower body (1).

4. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 1, characterized in that, The top surface of the guide plate (6) is a tapered surface that gradually decreases from the center of the tower body (1) towards the tower wall. The guide plate (6) has an installation hole (18) for the hollow gas distribution pipe (8) to pass through. The installation pipe body (7) is a hollow structure with an open bottom.

5. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 1, characterized in that, The hollow air distribution pipe (8) is provided with a threaded part (19), which is detachably connected to the mounting pipe body (7) through the threaded part (19). The air outlet pipe (9) is distributed in at least two layers along the axial direction of the hollow air distribution pipe (8), and the axis of each layer of the air outlet pipe (9) is inclined upward relative to the horizontal direction.

6. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 1, characterized in that, The hollow gas distribution pipe (8) is also provided with a baffle plate (20). The baffle plate (20) is located between the uppermost gas outlet pipe (9) and the conical cover plate (10). The baffle plate (20) is installed on the outside of the hollow gas distribution pipe (8) through a hinge shaft (21) and is configured to swing or vibrate under the impact of the flue gas flow from the gas outlet pipe (9).

7. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 6, characterized in that, The surface of the spoiler (20) facing the airflow is an arc-shaped guide surface (201), and the surface facing away from the airflow is provided with spaced protruding spoiler ribs (202).

8. The single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 1, characterized in that, It also includes a slurry collection plate (22), the inner wall of the tower body (1) is provided with a ring-shaped distribution of bearing blocks (23), the bottom of the slurry collection plate (22) is fixedly connected to an installation block (24), the bottom of the installation block (24) is provided with an installation slot (25) that cooperates with the bearing block (23), the bottom of the slurry collection plate (22) is provided with a receiving hole, the vertical section of the receiving hole is concave, the outer wall of the guide plate (6) is provided with a sealing rubber layer (26), and the guide plate (6) is sealed in the receiving hole by the sealing rubber layer (26).

9. A single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 8, characterized in that, The top of the slurry collection plate (22) is provided with a ring-shaped collection tank (27), the bottom of the collection tank (27) is an arc-shaped surface, and the bottom of the slurry collection plate (22) is symmetrically provided with a guide pipe (28) that communicates with the collection tank (27). The tower body (1) is also provided with a sludge removal component inside and above the guide plate (6).

10. A single-tower, two-stage, dual-absorbent wet desulfurization system according to claim 9, characterized in that, The dredging assembly consists of a positioning rod (29), a driving component (30), a rotating plate (31), and a dredging plate (32). The positioning rod (29) is an inverted T-shape. The outer wall of the tower body (1) is provided with a locking component (33). The locking component (33) passes through the tower body (1) and locks itself into the T-shaped transverse section of the positioning rod (29). The driving component (30) is connected to an external power supply and installed at the bottom of the T-shaped vertical section of the positioning rod (29). The rotating plate (31) is connected to the output shaft of the driving component (30) through a coupling. The dredging plate (32) is symmetrically fixed to the bottom of the rotating plate (31). The bottom surface of the dredging plate (32) is movably fitted with the liquid collection tank (27).

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