Ultralow-emission wet desulfurization tower
By adding a washing layer and a water spray layer inside the wet desulfurization tower, and using the inclined washing plates and gaps to form a water film, combined with the washing liquid circulation treatment, the problem of wet desulfurization towers being unable to achieve ultra-low emissions has been solved, and the effective removal of particulate matter in flue gas has been achieved, thus achieving ultra-low emission results.
Patent Information
- Application Number
- CN202520026920.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2035-01-06
AI Technical Summary
Existing wet desulfurization towers are unable to achieve ultra-low emissions, especially in the effective removal of fine particulate matter, which makes it difficult to reduce the concentration of particulate matter in flue gas and affects air quality.
A washing layer and a water spray layer are added inside the absorption tower. A water film is formed by the inclined washing plates and gaps. Combined with a washing liquid circulation treatment device, the washing water is cooled and filtered to enhance the washing effect on the flue gas, thereby capturing and removing microparticles.
It effectively removes particulate matter from flue gas, achieving ultra-low emission standards, reducing the concentration of particulate matter in flue gas, and improving air quality.
Smart Images
Figure CN223697238U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of wet desulphurization, particularly to a kind of ultra-low emission wet desulphurization tower. BACKGROUND
[0002] In WFGD wet desulphurization system, the limit value of particulate matter emission required by national standard is 20mg / Nm 3 With people's longing for a better life, someone proposes more stringent ultra-low emission requirements, hoping to achieve 10mg / Nm 3 Also proposed 5mg / Nm 3 .
[0003] Wet desulphurization system is a widely used flue gas treatment process, which can effectively reduce the concentration of sulfur dioxide emissions. At the same time, the evaporation entrainment of desulfurization slurry makes the desulfurization clean flue gas contain a large number of soluble salts and gypsum grains, which makes it difficult to reduce the concentration of fine particulate matter in the emission flue gas, which is currently maintained at about 15-30mg / Nm 3 Around the emission limit. In the wet desulphurization absorption tower, the high-temperature flue gas rises from bottom to top, first collides with the sprayed lime slurry desulfurization liquid, and then transmits mass and heat on the gas-liquid interface, resulting in a series of physical and chemical reactions. Desulfurization liquid not only absorbs SO2 in flue gas, but also absorbs soluble salt, especially soluble sulfate, and desulfurization liquid droplets also wrap gypsum grains. The droplets of desulfurization liquid evaporate water due to heat, making the droplets tend to be smaller, with a particle size distribution range of about 0-800um. When the flue gas entrains droplets passes through the demisting layer, large droplets are captured by the demister, and small droplets (≤30um) cannot be captured by the demister (which is determined by the characteristics of the demister itself), and then are discharged into the atmosphere from the chimney. Practice shows that in the wet desulfurization clean flue gas, 90% of the droplet particles are less than 30um, and more than half of them are less than 10um. These fine particulate matter and soluble sulfate entrained by the droplets are a major factor in the formation of haze, so it is of great practical significance to reduce the content of particulate matter in wet desulfurization flue gas emissions as much as possible.
[0004] Currently, there are methods to reduce the inlet temperature of flue gas, reduce the evaporation amount, and increase the droplet size. There are also methods to reduce the desulfurization liquid spray pressure and select large-diameter nozzles to increase the droplet size of the sprayed liquid. There are also methods to increase the liquid-gas ratio and add more spray layers to increase the droplet size. The purpose of these methods to increase the droplet size is to increase the probability of being captured when the flue gas passes through the demister. Increasing wet-type electric precipitator at the rear section of the desulfurization tower can effectively reduce the particulate matter emission, but the electricity cost is high, which is not easy to be accepted by many manufacturers. In newly built wet desulfurization system, single-tower double-circulation process or double-tower double-circulation process is also a good method for ultra-low emission, but it is difficult to achieve ultra-low emission in the widely used wet desulfurization tower.
[0005] Therefore, it is an urgent technical problem for those skilled in the art to provide a wet desulfurization tower capable of achieving ultra-low emission. Content of the utility model
[0006] The utility model discloses a wet desulfurization tower of ultra-low emission, which solves the problems of the prior art and can achieve ultra-low emission of the wet desulfurization tower.
[0007] To achieve the above object, the utility model provides the following scheme:
[0008] The utility model provides a wet desulfurization tower of ultra-low emission, it includes absorption tower body, washing layer, water spraying layer and washing liquid circulating treatment device, the washing layer sets up at the top of absorption tower body, the water spraying layer is located at the top of washing layer and is used to spray water to washing layer, the bottom of washing layer is provided with liquid collecting device, and the liquid collecting device is communicated with washing liquid circulating treatment device, and the washing liquid treated through washing liquid circulating treatment device is passed into water spraying layer.
[0009] The washing layer includes two washing plates arranged in an upper-lower interval, and the two washing plates are arranged in an inclination.
[0010] Preferably, the liquid collecting device is a liquid collecting groove arranged at the bottom of the washing layer.
[0011] Preferably, the washing liquid circulating treatment device includes a cooling tower, a water storage tank, a water pump, a primary filter and a secondary filter, the cooling tower is communicated with the water outlet at the bottom of the liquid collecting groove through a pipeline at the top, the bottom of the cooling tower is communicated with the water storage tank, the water outlet at the bottom of the water storage tank is connected with the water inlet of the water pump through a pipeline, the water outlet of the water pump is connected with the primary filter through a pipeline, the primary filter is connected with the secondary filter through a pipeline, and the secondary filter is connected with the water spraying layer through a backwater pipeline.
[0012] Preferably, the top of the water spraying layer is provided with a second mist removal layer.
[0013] Preferably, the top of the second mist removal layer is further provided with a chimney on the absorption tower body.
[0014] Preferably, one side of the chimney is provided with a sampling detection port.
[0015] Preferably, one side of the bottom of the absorption tower body is provided with a flue gas inlet.
[0016] Preferably, the absorption tower body between the flue gas inlet and the liquid collecting device is sequentially provided with a spraying layer and a first mist removal layer from bottom to top, and a mist eliminator flushing layer is arranged at the first mist removal layer.
[0017] Preferably, the spray layer is a lime slurry desulfurization liquid spray layer, and the spray layer is provided in 3 layers.
[0018] Preferably, the first demister layer has two layers, and the demister flushing layer is used to spray and flush the two layers of the first demister layer.
[0019] The present invention achieves the following technical advantages over the prior art:
[0020] The ultra-low emission wet desulfurization tower of this invention adds a washing layer and a water spraying layer inside the absorption tower body, above the topmost demisting layer. A water film can be formed on the upper and lower surfaces of the washing plates in the washing layer. When the flue gas after desulfurization and demisting passes between two inclined washing plates, a small amount of flue gas passes through the gaps in the washing plates, while most of the flue gas passes between the two plates, but cannot form a laminar flow. This causes the flue gas to continuously collide with the water film on the two surfaces of the washing plates. Most of the microparticles and soluble salts carried in the flue gas are cooled and trapped in the cooling water, thereby removing microparticles from the flue gas and reducing the amount of microparticles in the flue gas, thus achieving ultra-low emissions.
[0021] Furthermore, by adding a washing liquid circulation treatment device, the washing water is filtered and cooled. While removing microparticles, the water sprayed from the spray layer is also cooling water. The washing of the flue gas by the cooling water objectively reduces the flue gas temperature, causing the flue gas to release saturated water, reducing the amount of water mist entrained in the flue gas, and also reducing microparticles. This further reduces the microparticles carried by the flue gas and reduces emissions. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments 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.
[0023] Figure 1 This is a schematic diagram of the ultra-low emission wet desulfurization tower in this utility model;
[0024] Figure 2 This is a schematic diagram of the structure of the washing plate in this utility model;
[0025] In the diagram: 1. Absorption tower body; 2. Flue gas inlet; 3. Spray layer; 4. First demister layer; 5. Demister flushing layer; 6. Chimney; 7. Sampling and testing port; 8. Washing layer; 81. Washing plate; 82. Gap; 9. Water spray layer; 10. Liquid collection tank; 11. Second demister layer; 12. Cooling tower; 13. Water storage tank; 14. Water pump; 15. Primary filter; 16. Secondary filter. Detailed Implementation
[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0027] The purpose of this invention is to provide an ultra-low emission wet desulfurization tower to solve the problems existing in the prior art.
[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] The ultra-low emission wet desulfurization tower in this embodiment, such as Figure 1 As shown, it includes an absorption tower body 1, a washing layer 8, a spray layer 9, and a washing liquid circulation treatment device. The washing layer 8 is located at the top of the absorption tower body 1. The spray layer 9 is located at the top of the washing layer 8 and is used to spray water onto the washing layer 8. A liquid collection device is provided at the bottom of the washing layer 8. The liquid collection device is connected to the washing liquid circulation treatment device. The washing liquid treated by the washing liquid circulation treatment device is introduced into the spray layer 9.
[0030] The washing layer 8 includes two washing plates 81 that are spaced apart vertically. The two washing plates 81 are inclined, and each washing plate 81 has multiple horizontally arranged slits 82.
[0031] In this specific embodiment, the liquid collection device is a liquid collection tank 10 disposed at the bottom of the washing layer 8.
[0032] In this specific embodiment, the washing liquid circulation treatment device includes a cooling tower 12, a water storage tank 13, a water pump 14, a primary filter 15, and a secondary filter 16. The top of the cooling tower 12 is connected to the outlet at the bottom of the liquid collection tank 10 via a pipeline. The bottom of the cooling tower 12 is connected to the water storage tank 13. The outlet at the bottom of the water storage tank 13 is connected to the inlet of the water pump 14 via a pipeline. The outlet of the water pump 14 is connected to the primary filter 15 via a pipeline. The primary filter 15 is connected to the secondary filter 16 via a pipeline. The secondary filter 16 is connected to the spray layer 9 via a return water pipeline.
[0033] In this specific embodiment, a second demisting layer 11 is provided on the top of the water spray layer 9.
[0034] In this specific embodiment, a chimney 6 is also provided on the absorption tower body 1 at the top of the second demisting layer 11, and a sampling and detection port 7 is provided on one side of the chimney 6.
[0035] In this specific embodiment, a flue gas inlet 2 is provided on one side of the bottom of the absorption tower body 1.
[0036] In this specific embodiment, a spray layer 3 and a first demister layer 4 are arranged sequentially from bottom to top inside the absorption tower body 1 between the flue gas inlet 2 and the liquid collection device, and a demister flushing layer 5 is provided at the first demister layer 4.
[0037] In this specific embodiment, the spray layer 3 is a lime slurry desulfurization liquid spray layer 3, and the spray layer 3 is provided with 3 layers.
[0038] In this specific embodiment, the first demister layer 4 is provided with two layers, and the demister flushing layer 5 is used to spray and flush the two layers of the first demister layer 4.
[0039] The working principle of the ultra-low emission wet desulfurization tower in this invention is as follows:
[0040] The clean flue gas after desulfurization and demisting is washed through the washing layer 8. The washing water is introduced outside the absorption tower through the collection tank and automatically flows to the cooling tower 12 by utilizing the height difference. The washing liquid circulation treatment device cools the washing water through the cooling tower 12 to turn it into cooling water. The cooling water in the storage tank 13 is drawn by the water pump 14 and then passed through the primary filter 15 and the secondary filter 16 (or, through a membrane filter again) before being pumped back into the tower and circulated through the spray layer 9 for washing.
[0041] like Figure 2As shown, the washing plate 81 is a flat plate with many horizontally laser-cut slits 82. When the washing plate 81 is installed at an angle (the slits 82 are horizontal), its upper surface receives cooling water sprayed from the water spray layer 9 (cooled by the cooling tower 12). When the water volume is large enough, a water curtain layer similar to a waterfall is uniformly formed on the upper surface and flows downwards along the upper surface. When the water curtain passes through the slits 82, most of it flows past the slits 82 and continues to flow downwards. Due to the surface tension of the water, the slits 82 play a role in making the water curtain more uniform in the horizontal direction, so that the entire upper surface of the washing plate 81 is covered with cooling water and there is no drying phenomenon. A small portion of the cooling water will flow through the slits 82 to the lower surface of the washing plate 81. Similarly, under the action of the surface tension of the water, most of the cooling water on the lower surface is spread along the lower surface of the washing plate 81 and will not fall off, thus forming a water film layer on the lower surface as well. In this way, water films are present on both the upper and lower surfaces of the washing plates 81. When the desulfurized and demisting flue gas passes between the two inclined washing plates 81, a small amount of flue gas passes through the gaps 82 of the washing plates 81, while most of the flue gas passes between the two plates. However, laminar flow cannot be formed, causing the flue gas to continuously collide with the water films on both surfaces of the washing plates 81. Most of the microparticles and soluble salts entrained in the flue gas are cooled and trapped in the cooling water, thus greatly reducing the amount of microparticles in the flue gas. The purpose of using cooling water is also because the washing of the flue gas by the cooling water objectively lowers the flue gas temperature, causing the flue gas to precipitate saturated water, reducing the amount of water mist entrained in the flue gas, and also playing a role in reducing microparticles.
[0042] The biggest difference between the washing plate 81 and the demister plate is that the water film layer on the washing plate 81 is thicker. When the droplets in the flue gas collide with the water film, they quickly nucleate and grow in the water film. The tiny droplets are encapsulated and enclosed by the water film and are washed away. On the other hand, the surface of the demister plate can only be wet at most, and some parts are even dry. There is no water film present, so it cannot play the role of encapsulation and encapsulation, and therefore cannot remove the micro-droplets.
[0043] The purpose of the defogging layer above the washing layer 8 is to capture large water molecules formed during the washing process and reduce the amount of water vapor emitted from the chimney 6.
[0044] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.
Claims
1. An ultra-low emission wet desulfurization tower, characterized in that: The system includes an absorption tower body, a washing layer, a spray layer, and a washing liquid circulation and treatment device. The washing layer is located at the top of the absorption tower body. The spray layer is located at the top of the washing layer and is used to spray water onto the washing layer. A liquid collection device is located at the bottom of the washing layer and is connected to the washing liquid circulation and treatment device. The washing liquid treated by the washing liquid circulation and treatment device is then introduced into the spray layer. The washing layer includes two washing plates spaced apart vertically. The two washing plates are inclined, and each washing plate has multiple horizontally spaced slits.
2. The ultra-low emission wet desulfurization tower according to claim 1, characterized in that: The liquid collection device is a liquid collection tank located at the bottom of the washing layer.
3. The ultra-low emission wet desulfurization tower according to claim 2, characterized in that: The washing liquid circulation treatment device includes a cooling tower, a water storage tank, a water pump, a primary filter, and a secondary filter. The top of the cooling tower is connected to the outlet at the bottom of the liquid collection tank via a pipeline. The bottom of the cooling tower is connected to the water storage tank. The outlet at the bottom of the water storage tank is connected to the inlet of the water pump via a pipeline. The outlet of the water pump is connected to the primary filter via a pipeline. The primary filter is connected to the secondary filter via a pipeline. The secondary filter is connected to the spray layer via a return water pipeline.
4. The ultra-low emission wet desulfurization tower according to claim 1, characterized in that: A second demisting layer is provided on top of the water spray layer.
5. The ultra-low emission wet desulfurization tower according to claim 4, characterized in that: A chimney is also provided on the absorption tower body at the top of the second demisting layer.
6. The ultra-low emission wet desulfurization tower according to claim 5, characterized in that: A sampling and testing port is provided on one side of the chimney.
7. The ultra-low emission wet desulfurization tower according to claim 1, characterized in that: A flue gas inlet is provided on one side of the bottom of the absorption tower.
8. The ultra-low emission wet desulfurization tower according to claim 7, characterized in that: The absorption tower body between the flue gas inlet and the liquid collection device is provided with a spray layer and a first demister layer from bottom to top, and a demister flushing layer is provided at the first demister layer.
9. The ultra-low emission wet desulfurization tower according to claim 8, characterized in that: The spray layer is a lime slurry desulfurization liquid spray layer, and the spray layer is provided in 3 layers.
10. The ultra-low emission wet desulfurization tower according to claim 8, characterized in that: The first demister layer has two layers, and the demister flushing layer is used to spray and flush the two layers of the first demister layer.