Multi-stage rotary plate spray tower absorption device for preparing nitroso sulfuric acid
The multi-stage rotary plate spray tower absorption device solves the problems of gaseous pollution emissions and equipment corrosion in the production of nitrososulfuric acid, and achieves efficient NOx conversion and stable equipment operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG LINJIANG CHEM
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-05
AI Technical Summary
The existing nitrososulfuric acid production process generates polluting gases that are directly emitted, causing serious environmental pollution. Single-stage absorption towers have low NOx conversion rates, and traditional spray towers have insufficient gas-liquid contact, making them prone to clogging and consuming a lot of energy. Acid mist entrainment leads to severe equipment corrosion.
The multi-stage swirl plate spray tower absorption device processes the gas step by step through a multi-stage spray system. The Z-shaped baffle pipe and swirl plate design improve the gas-liquid contact efficiency. The swirl plates are equipped with swirl guide holes and demister plates to promote the oxidation of NO to NO2, enhance the gas-liquid reaction, and prevent blockage and corrosion.
It enables continuous production of nitrososulfuric acid, meets NOx emission standards, improves gas conversion efficiency, extends equipment life, reduces energy consumption, and prevents equipment corrosion.
Smart Images
Figure CN224194446U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of waste gas treatment technology, and more specifically, relates to a multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid. Background Technology
[0002] Existing nitrososulfuric acid production processes generate polluting gases, which, when directly emitted, cause serious pollution to the surrounding environment. Therefore, waste gas treatment is necessary. Currently, single-stage absorption towers generally have low NOx conversion rates, traditional spray towers have insufficient gas-liquid contact, resulting in high tail gas emissions, easy clogging of spray towers, high energy consumption, and severe corrosion of subsequent treatment equipment due to acid mist entrainment. Therefore, a multi-stage rotary plate spray tower absorption device that can continuously produce nitrososulfuric acid and meet NOx emission standards is needed. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide a multi-stage rotary plate spray tower absorption device for the preparation of nitrososulfuric acid, which can meet the requirements of continuous preparation of nitrososulfuric acid by the multi-stage rotary plate spray tower absorption device and NOx emission compliance.
[0004] This invention relates to a multi-stage swirl plate spray tower absorption device for preparing nitrososulfuric acid, comprising a multi-stage spray system, spray towers, gas pipelines, spray units, swirl plates, a water tank, and a drying tower. The multi-stage spray system consists of multiple independent spray towers connected in series via gas pipelines. The gas pipelines between adjacent spray towers are designed as Z-shaped baffles, so that when the gas rises, it carries droplets and collides with the tower wall due to inertia at the height difference turning point, improving the demisting efficiency. The centerlines of adjacent spray towers are offset from each other, forcing the gas to change direction, improving the mass transfer efficiency, extending the gas residence time, promoting the oxidation of NO to NO2, and improving the preparation capacity of nitrososulfuric acid. At least one swirl plate is fixedly installed inside the spray tower to enhance the gas-liquid contact efficiency. Each stage of the spray tower is independently and fixedly connected to the spray unit. The main end of the spray unit is fixedly connected to the water tank. The last stage of the spray tower is connected to the drying tower via the gas pipeline.
[0005] As a further improvement of this utility model, the spray tower includes an air inlet, an air outlet, a spray nozzle, and a support ring. The air supply end and the air delivery end of the gas pipeline are respectively connected to the air inlet and the air outlet adjacent to the spray tower. The spray nozzle is fixedly connected to the spray unit. The rotating plate is fixedly connected to the support ring by bolts. The air inlet is opened at the lower end of the spray tower, and the air outlet is opened at the upper end of the spray tower. The spray nozzle and the support ring are located between the air inlet and the air outlet, and the spray nozzle is higher than the support ring. The support ring is installed on the inner wall of the spray tower to guide the gas to rotate and rise through the rotating plate of the support ring, so that the liquid of the spray unit is sprayed into droplets, increasing the gas-liquid contact area and improving the mass transfer efficiency.
[0006] As a further improvement of this utility model, the spray nozzles are set as a pair, with the pair of spray nozzles at the same height on both sides of the spray tower, and each spray nozzle is independently connected to a spray unit to increase the gas-liquid contact efficiency.
[0007] As a further improvement of this utility model, several swirl plates are fixedly installed inside the spray tower to increase the gas flow path, promote full gas reaction, stabilize the distribution of airflow and liquid flow, reduce swirl accumulation at the swirl plate installation point, reduce wear and corrosion of local areas by swirl, and extend the service life of the equipment.
[0008] As a further improvement of this utility model, the swirl plate is provided with a number of swirling air guide holes, and the diameter of the swirling air guide holes gradually decreases as the number of stages of the spray tower increases, so as to gradually intercept particles of different sizes, improve efficiency and prevent particle blockage.
[0009] As a further improvement of this utility model, a demister plate is fixedly installed inside the spray tower. The demister plate is installed above the rotary plate and below the spray unit to purify water mist, prevent the gas from carrying away moisture, and allow the gas to be dehydrated and discharged. The vertical distance between the two forms a buffer transition zone to ensure that the airflow speed is reduced. The demister plate completely covers the opening area of the rotary plate, forcing all airflow to pass through the demister plate channel, thereby increasing the droplet interception efficiency by increasing the gas travel path.
[0010] As a further improvement of this utility model, an expansion gap is maintained between the edge of the rotary plate and the inner wall of the spray tower to increase stability and prevent vibration.
[0011] Compared with existing technologies, the advantages of this utility model are as follows: A multi-stage spray system is provided, which processes the gas step-by-step through multiple spray towers connected in series, improving gas conversion efficiency; the gas transmission pipeline between adjacent spray towers is designed as a Z-shaped baffle, so that when the gas rises, it carries droplets and collides with the tower wall due to inertia at the height difference turning point, improving demisting efficiency; the centerlines of adjacent spray towers are offset from each other, forcing the gas to change direction, improving mass transfer efficiency, extending gas residence time, promoting the oxidation of NO to NO2, and improving the production capacity of nitrososulfuric acid; a pair of spray nozzles leading into the spray unit are provided to increase gas-liquid contact efficiency and accelerate gas processing speed; the aperture of the swirl guide holes gradually decreases with the increase of the number of spray tower stages to intercept particles of different sizes and prevent the swirl plates from clogging; a demisting plate is installed above the swirl plates to purify water mist, prevent the gas from carrying moisture, and allow the gas to be dehydrated and discharged; an expansion gap is maintained between the edge of the swirl plates and the inner wall of the spray tower to increase stability and prevent vibration. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of this utility model;
[0013] Figure 2 This is a schematic diagram of the front section of the spray tower of this utility model;
[0014] Figure 3 For the present utility model Figure 2 Enlarged view of the region;
[0015] Figure 4 This is a top view of the spray tower and a schematic diagram showing the offset of the center line of this utility model;
[0016] Figure 5 This is a schematic diagram of the rotary plate structure of this utility model;
[0017] Figure 6 This is a comparative schematic diagram of the swirling air guide holes of each level of the swirl plate of this utility model.
[0018] Explanation of the labels in the diagram:
[0019] 1. Multi-stage spray system; 2. Spray tower; 21. Air inlet; 22. Air outlet; 23. Spray nozzle; 24. Support ring; 3. Gas pipeline; 4. Spray unit; 5. Rotary plate; 51. Swirl air guide hole; 52. Demisting plate; 6. Spray pipeline; 7. Water tank; 8. Drying tower. Detailed Implementation
[0020] Specific Implementation Example 1: Please refer to Figures 1-6 This utility model relates to a multi-stage swirl plate spray tower absorption device for preparing nitrososulfuric acid, comprising a multi-stage spray system 1, spray towers 2, gas pipelines 3, spray units 4, swirl plates 5, a water tank 7, and a drying tower 8. The multi-stage spray system 1 consists of eight independent spray towers 2 connected in series via gas pipelines 3. The gas pipelines 3 between adjacent spray towers 2 are designed as Z-shaped baffles. When the gas rises, it carries droplets that collide with the tower wall due to inertia at the height difference turning point, improving the demisting efficiency. The centerlines of adjacent spray towers 2 are offset along the gas conveying direction. The centerlines of the second, fourth, sixth, and eighth stage spray towers 2 are offset by 150 mm from the centerlines of their adjacent spray towers 2, forcing the gas to change direction. To improve mass transfer efficiency, extend gas residence time, and promote the oxidation of NO to NO2, a rotating plate 5 is fixedly installed inside the spray tower 2 to enhance gas-liquid contact efficiency. Each stage of the spray tower 2 is independently and fixedly connected to the spray unit 4. The concentration of sulfuric acid sprayed from the spray unit 4 increases progressively with the gas entering the spray tower 2. The specific concentration gradient is designed based on actual usage experience. The main end of the spray unit 4 is fixedly connected to the water tank 7. The eighth-stage spray tower 2 is connected to the drying tower 8 through the gas pipeline 3 to dry the output gas at the end of the multi-stage spray system 1 and reduce the water content of the output gas. A valve is installed at the connection between the water tank 7 and the spray pipeline 6 to control the total liquid supply flow of the entire system to match the multi-stage spray requirements.
[0021] In a further embodiment, such as Figure 2As shown, the spray tower 2 includes an air inlet 21, an air outlet 22, a pair of spray nozzles 23, and a support ring 24. The air supply end and the air delivery end of the air pipeline 3 are respectively connected to the air inlet 21 and the air outlet 22 adjacent to the spray tower 2. The pair of spray nozzles 23 are respectively fixedly connected to a spray unit 4. The rotating plate 5 is fixedly connected to the support ring 24 by bolts. The air inlet 21 is opened at the lower end of the spray tower 2, the air outlet 22 is opened at the upper end of the spray tower 2, and the pair of spray nozzles 23 are set at the same height on the spray tower 2. On both sides, a pair of spray nozzles 23 and a support ring 24 are located between the air inlet 21 and the air outlet 22, with the spray nozzles 23 being higher than the support ring 24. The support ring 24 is installed on the inner wall of the spray tower 2, guiding the gas to rotate and rise through the swivel plate 5 of the support ring 24, so that the liquid in the spray unit 4 is sprayed into droplets, increasing the gas-liquid contact area and improving the mass transfer efficiency. The spray unit 4 is equipped with a valve, which controls the spray flow rate, thereby adjusting the gas-liquid ratio in different stages of the spray tower 2 to improve the gas conversion efficiency.
[0022] In a further embodiment, such as Figure 2 As shown, two swirl plates 5 are fixedly installed inside the spray tower 2 to create more swirling areas, increase the gas flow path, promote full gas reaction, stabilize the distribution of air and liquid flow, reduce swirling accumulation at the swirl plate installation location, reduce wear and corrosion of local areas by swirling, and extend the service life of the equipment.
[0023] In a further embodiment, such as Figure 6 As shown, the swirl plate 5 is provided with several swirling air guide holes 51. The swirling air guide holes 51 on the swirl plate 5 installed in the 1st to 3rd stage spray tower 2 are set with a large aperture to trap particles with a diameter greater than 50μm. The swirling air guide holes 51 on the swirl plate 5 installed in the 4th to 6th stage spray tower 2 are set with a medium aperture to trap particles with a diameter of 10-50μm. The swirling air guide holes 51 on the swirl plate 5 installed in the 7th to 8th stage spray tower 2 are set with a small aperture to trap particles with a diameter not greater than 10μm. A demister plate 52 is fixedly installed at the upper end of the swirl plate 5 to purify water mist, prevent the gas from carrying away moisture, and allow the gas to be dehydrated and discharged.
[0024] In a further embodiment, such as Figure 2 As shown, the demister plate 52 is installed above the rotary plate 5 with a vertical distance of 200mm between them, forming a buffer transition zone to ensure that the airflow speed is reduced, making it easier for droplets to be captured due to gravity and inertia. The demister plate 52 completely covers the opening area of the rotary plate 5, forcing all airflow to pass through the demister plate channel, thereby increasing the droplet interception efficiency by increasing the gas travel path.
[0025] In a further embodiment, such as Figure 3 As shown, a 3mm expansion gap is maintained between the edge of the rotary plate 5 and the inner wall of the spray tower 2 to increase stability and prevent vibration stress from damaging the rotary plate 5.
[0026] When gas containing nitrogen oxides enters the bottom of the first-stage spray tower 2 through the inlet 21, the gas first forms a rotating upward airflow through the large-diameter swirl plate 5, which mixes thoroughly with the sulfuric acid droplets sprayed from the spray units 4 on both sides, initiating a preliminary absorption reaction and intercepting large particles. Subsequently, the gas exits through the outlet 22 and enters the subsequent spray towers 2 through the Z-shaped baffle gas pipeline 3, where the above mixing operation is carried out. When entering the fourth and seventh-stage spray towers 2, the diameter of the swirl plate guide holes 51 is changed to medium and small diameters, respectively, and the concentration of sulfuric acid sprayed in the spray tower 2 increases step by step. The nitrogen oxides in the gas are transformed in stages and depths. At the same time, the demister plate 52 above each swirl plate 5 continuously intercepts the escaping droplets. After eight stages of spray treatment, the gas enters the terminal drying tower 8 to remove residual moisture and acid mist, and finally, qualified gas is discharged.
Claims
1. A multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid, characterized in that: The system includes a multi-stage spray system (1), a spray tower (2), an air supply pipeline (3), a spray unit (4), and a rotary vane (5). The multi-stage spray system (1) is composed of multiple independent spray towers (2) connected in series through the air supply pipeline (3). At least one rotary vane (5) is fixedly installed inside the spray tower (2). The spray tower (2) includes an air inlet (21), an air outlet (22), and a spray nozzle (23). The air inlet (21) is located at the bottom of the spray tower (2). The air outlet (22) is located at the upper end of the spray tower (2), and the spray nozzle (23) is located between the air inlet (21) and the air outlet (22). The air supply end and the air delivery end of the gas pipeline (3) are respectively connected to the air inlet (21) and the air outlet (22) of the adjacent spray tower (2). The spray nozzle (23) is fixedly connected to the spray unit (4). The installation position of the rotary plate (5) in the spray tower (2) is lower than the spray nozzle (23) and higher than the air inlet (21).
2. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: The gas transmission pipeline (3) between adjacent spray towers (2) is set as a Z-type baffle pipeline, and the center lines of adjacent spray towers (2) are offset from each other.
3. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: The spray tower (2) also includes a support ring (24) installed on the inner wall of the spray tower (2). The rotary plate (5) is fixedly connected to the support ring (24) by bolts. The support ring (24) is located between the air inlet (21) and the air outlet (22), and the spray nozzle (23) is higher than the support ring (24).
4. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: The swirl plate (5) is provided with several swirling air guide holes (51), and the diameter of the swirling air guide holes (51) gradually decreases as the number of stages of the spray tower (2) increases.
5. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: It also includes a spray pipeline (6), a water tank (7) and a drying tower (8). The other end of the spray unit (4) connected to each spray tower (2) is independently connected to the spray pipeline (6). The main end of the spray pipeline (6) is fixedly connected to the water tank (7). The last spray tower (2) in the multi-stage spray system (1) is connected to the drying tower (8) through the gas pipeline (3).
6. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 4, characterized in that: An expansion gap is maintained between the edge of the rotary plate (5) and the inner wall of the spray tower (2).
7. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: Spray nozzles (23) are set as a pair, and the pair of spray nozzles (23) are set at the same height on both sides of the spray tower (2). Each spray nozzle (23) is independently connected to a spray unit (4).
8. The multi-stage rotary plate spray tower absorption device for preparing nitrososulfuric acid according to claim 1, characterized in that: A demisting plate (52) is fixedly installed inside the spray tower (2). The demisting plate (52) is installed above the rotary plate (5) and below the spray unit (4). The demisting plate (52) completely covers the opening area of the rotary plate (5).