Static gas mixer
By using a static gas mixer in the mixing pipe, the problem of uneven mixing of ammonia and flue gas is solved, the denitrification efficiency is improved, ammonia escape is reduced, the equipment life is extended, the cost is reduced, and environmental protection standards are met.
Patent Information
- Application Number
- CN202511095830.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2025-09-23
AI Technical Summary
The traditional mixing pipe design causes uneven mixing of ammonia and flue gas, resulting in excessively high or low reducing agent concentrations in some areas. High-concentration areas are prone to ammonia escape, while low-concentration areas experience insufficient denitrification reactions and low overall denitrification efficiency.
A static gas mixer is used, including guide plates and reinforcement rods that are staggered and spliced obliquely. The guide plates are embedded in the inner wall of the mixing pipe, with the included angle set to 45° or 135°. They are arranged in a scissor-like shape, with odd layers staggered. There are 10 groups of guide plates in the center layer, made of 304 stainless steel, and are used in the mixing pipe.
Improve denitrification efficiency by more than 20%, reduce ammonia escape rate to below 2.5mg/m³, minimize equipment corrosion damage, reduce reducing agent consumption, extend equipment life, reduce maintenance costs, and ensure environmental compliance.
Smart Images
Figure CN120679382A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of degassing equipment, in particular to a static gas mixer installed in a mixing pipeline. Background Art
[0002] A large amount of nitrogen oxides are produced in the production activities of various industries such as coal-fired power plants, industrial boilers, steel mills, cement plants, etc. As environmental protection requirements become increasingly stringent, nitrogen oxides, as an important source of air pollution, their emission control has attracted much attention.
[0003] Among the many denitrification technologies, selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) technologies are widely used. Both use ammonia as a reducing agent, which reacts with nitrogen oxides in the flue gas to produce nitrogen and water under certain conditions.
[0004] However, in actual operation, the problem of uneven mixing of the reducing agent ammonia and the flue gas is common, resulting in excessively high or too low reducing agent concentrations in some areas. High-concentration areas are prone to ammonia escape, causing secondary pollution and waste of resources, while low-concentration areas have insufficient denitrification reactions, resulting in low overall denitrification efficiency.
[0005] The main reason for the low overall denitrification efficiency is that the traditional mixing pipe design makes it difficult to evenly distribute the airflow, which cannot meet the requirement of efficient denitrification for sufficient mixing of ammonia and flue gas, thus restricting the full performance of the denitrification equipment. Summary of the Invention
[0006] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a
[0007] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a static gas mixer, assembled into a mixing pipe, including guide plates, which are staggered and spliced in an inclined shape, and the outer edge of the overall structure obtained by splicing the guide plates is kept in engagement with the inner wall of the mixing pipe.
[0008] The overall structure formed by splicing the guide plates appears to be scissor-shaped in a radial perspective of the mixing pipe.
[0009] Based on the above technical solution, to ensure the structural stability and service life of the mixer when assembled in the mixing duct, the following technical solution is provided: It further includes a reinforcing rod connected to the intersection of the guide plates, with the end of the reinforcing rod being engaged with the inner wall of the mixing duct.
[0010] The guide plate and the reinforcing rod are both made of 304 stainless steel.
[0011] The reinforcing rod adopts a solid rod structure or a hollow pipe structure.
[0012] On the basis of the above technical solution, in order to ensure that the mixer can fully mix and react ammonia and flue gas containing nitrogen oxides, the following technical solution is provided: The angle between the guide plate and the axis of the mixing pipe is set to 45° or 135°.
[0013] The guide plates that form two angles with the axis of the mixing pipe appear to be arranged alternately in the axial view of the mixing pipe.
[0014] The guide plates arranged in a scissor-like manner are arranged in an odd number of layers, and two adjacent groups of guide plates in the same layer are arranged in a staggered manner, and the guide plates in the central layer are located at the axis of the mixing pipe.
[0015] There are three layers of guide plates arranged in a scissor-like shape, and there are 10 groups of guide plates in the center layer.
[0016] Beneficial effects of the present invention: 1. Improve denitrification efficiency. The mixer provided in this application can make the flue gas and ammonia mix more evenly, and can fully contact in the reaction zone to increase the reaction probability, thereby effectively improving the denitrification efficiency. The removal rate of nitrogen oxides can be increased by more than 20% on the original basis, ensuring that the flue gas emissions of relevant enterprises stably meet or even exceed national and local environmental protection standards, reducing environmental pollution risks while enhancing the competitiveness of enterprises in environmental compliance.
[0017] 2. Reduce the ammonia escape rate. The mixer can evenly mix the flue gas and ammonia, significantly reducing the phenomenon of excessively high local ammonia concentration and suppressing ammonia escape from the source. After actual operation monitoring, the ammonia escape rate can be reduced to below 2.5mg / m³. On the one hand, it reduces the corrosion damage to equipment pipelines, catalysts, etc. caused by ammonia escape, extends the service life of the equipment, and reduces maintenance costs. On the other hand, it prevents the escaped ammonia from reacting with other components in the flue gas in the downstream process to form sticky substances such as ammonium bisulfate, which then clogs the catalyst, ensuring the smooth operation of the denitrification system and subsequent process flows, and improving the reliability and stability of the entire production system.
[0018] 3. Energy saving and consumption reduction and cost optimization. Efficient mixing shortens the time for ammonia and flue gas to reach reaction equilibrium. Therefore, the injection amount of reducing agent ammonia can be appropriately reduced, and the ammonia consumption can be reduced while ensuring the denitrification effect. At the same time, it reduces the resource investment such as repeated adjustment of operating parameters and equipment failure maintenance caused by poor mixing, realizes the comprehensive optimization of the denitrification system operation cost, and has significant economic benefits.
[0019] 4. The material advantage gives long-term stable performance. The 304 stainless steel material is selected, which can withstand high temperatures of up to 800℃ and is suitable for long-term stable use. At the same time, it has excellent corrosion resistance and can still maintain complete structure and excellent performance under complex flue gas conditions such as sulfur and nitrate. It reduces the frequency of replacing the mixer due to material damage, reduces equipment maintenance and replacement costs, and ensures the efficient and stable operation of the mixing link of the denitrification equipment in the long term. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the present invention observed along the axial direction of the mixing pipe; Figure 3 This is a schematic diagram of the present invention observed along the radial perspective of the mixing pipe; Figure 4 This is a droplet duration diagram of the urea spray test under 100% working conditions of the present invention; Figure 5 This is a graph of droplet urea concentration in a urea spray test under 100% working conditions of the present invention; Figure 6 This is the velocity streamline diagram of the flue gas input under 100% working condition of the present invention; Figure 7 This is the temperature streamline diagram of the flue gas input under 100% working condition of the present invention; Figure 8 This is the flow chart of the present invention when ammonia is input under 100% working condition; Figure 9 The flow chart of the present invention when ammonia and nitrogen dioxide are input under 100% working condition; Figure 10 This is the velocity distribution diagram of ammonia and flue gas at the center section of the mixer under 100% working conditions of the present invention; Figure 11 This is the temperature distribution diagram of ammonia and flue gas at the center section of the mixer under 100% working conditions of the present invention; Figure 12 This is the distribution diagram of the molar ratio of ammonia to flue gas at the center section of the mixer under 100% working conditions of the present invention; Figure 13 This is a droplet duration diagram of the urea spray test under 75% working conditions of the present invention; Figure 14 This is a graph of droplet urea concentration in a urea spray test under 75% working conditions of the present invention; Figure 15 This is the velocity streamline diagram of the flue gas input under 75% working condition of the present invention; Figure 16 This is the temperature streamline diagram of the flue gas input under 75% working condition of the present invention; Figure 17This is the flow chart of the present invention when ammonia is input under 75% working condition; Figure 18 The flow chart of the present invention when ammonia and nitrogen dioxide are input at 75% working condition; Figure 19 This is the velocity distribution diagram of ammonia and flue gas at the center section of the mixer under 75% working condition of the present invention; Figure 20 This is the temperature distribution diagram of ammonia and flue gas at the center section of the mixer under 75% working condition of the present invention; Figure 21 This is the distribution diagram of the molar ratio of ammonia to flue gas at the center section of the mixer under 75% working condition of the present invention; Figure 22 This is a droplet duration diagram of the urea spray test under 50% working conditions of the present invention; Figure 23 This is a graph of droplet urea concentration in a urea spray test under 50% working conditions of the present invention; Figure 24 This is the velocity streamline diagram of the flue gas input under 50% working condition of the present invention; Figure 25 This is the temperature streamline diagram of the flue gas input under 50% working condition of the present invention; Figure 26 This is the flow chart of the present invention when ammonia is input under 50% working condition; Figure 27 The flow chart of the present invention when ammonia and nitrogen dioxide are input at 50% working condition; Figure 28 This is the velocity distribution diagram of ammonia and flue gas at the center section of the mixer under 50% working condition of the present invention; Figure 29 This is the temperature distribution diagram of ammonia and flue gas at the center section of the mixer under 50% working condition of the present invention; Figure 30 This is the distribution diagram of the molar ratio of ammonia to flue gas at the center section of the mixer under 50% working conditions of the present invention.
[0021] In the picture: 110 deflector, 120 reinforcement rod. DETAILED DESCRIPTION
[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example
[0023] See also Figure 1-Figure 3A static gas mixer is assembled into a mixing pipe and includes guide plates 110. The guide plates 110 are staggered and spliced in an inclined manner. The outer edge of the overall structure obtained by splicing the guide plates 110 is kept in engagement with the inner wall of the mixing pipe.
[0024] The overall structure formed by splicing the guide plates 110 appears to be scissor-shaped in a radial perspective of the mixing duct.
[0025] When the guide plates 110 are staggered and spliced in an inclined manner, they can completely fill the cross-sectional space in the axial perspective of the mixing pipe, so that the airflow transmitted axially along the mixing pipe will inevitably collide with the guide plates 110 and change the transmission path, thereby effectively increasing the contact probability of different gases (ammonia, flue gas containing nitrogen oxides).
[0026] In the radial perspective of the mixing duct, the guide plate 110 is scissor-shaped to form a sufficient collision and accommodation area for the ammonia and the flue gas containing nitrogen oxides to fully collide and react.
[0027] To ensure the structural stability and service life of the mixer when assembled in the mixing pipe, the following technical solution is provided: It also includes a reinforcing rod 120, which is connected to the cross-connected portion of the guide plate 110, and the end of the reinforcing rod 120 is kept in engagement with the inner wall of the mixing pipe.
[0028] The guide plate 110 and the reinforcing rod 120 are both made of 304 stainless steel.
[0029] The reinforcing rod 120 adopts a solid rod structure or a hollow tube structure.
[0030] The reinforcing rod 120 and the guide plate 110 are assembled by welding, and can also be fixedly embedded in the mixing pipe by welding.
[0031] The use of 304 stainless steel can effectively improve the performance of the guide plate 110 and the reinforcing rod 120 in coping with harsh environments, thereby enabling them to be used stably for a long time in an atmosphere of ammonia and flue gas containing nitrogen oxides.
[0032] The reinforcing rod 120 has higher structural strength when adopting a rod structure, and can effectively reduce its own weight when adopting a pipe structure, thereby achieving the purpose of saving materials. The specific selection criteria can be determined according to the application scenario and needs. Example
[0033] See also Figure 1-Figure 3 On the basis of Example 1, in order to ensure that the mixer can fully mix and react ammonia and flue gas containing nitrogen oxides, the following technical solution is provided: The angle between the guide plate 110 and the axis of the mixing pipe is set to 45° or 135°.
[0034] The guide plates 110 that form two angles with the axis of the mixing pipe are arranged alternately in the axial direction of the mixing pipe.
[0035] The guide plates 110 arranged in a scissor-like manner are arranged in an odd number of layers. Two adjacent groups of guide plates 110 in the same layer are arranged in a staggered manner, and the guide plates 110 in the center layer are located at the axis of the mixing pipe.
[0036] The guide plates 110 are arranged in a scissor-like manner and are provided in three layers, with a total of 10 groups of guide plates 110 in the central layer.
[0037] Based on the above solution, the spacing between the scissor-shaped deflectors 110 in adjacent layers was set to 500 mm, and the width of each deflector 110 was set to 200 mm. The deflectors 110 in the middle layer were set to 700 mm in length, and their axial length along the mixing duct was also 500 mm. This optimized layout was then assembled into the mixing duct for use. Example
[0038] See also Figure 4-12 The performance test of the mixer used in Example 3 under 100% working conditions was carried out according to the urea spray test, the flue gas flow line test, the ammonia flow line test, the velocity and temperature distribution test of the central section of the mixer, and the molar ratio distribution of ammonia and ammonia nitrogen.
[0039] Depend on Figure 4-Figure 5 It can be seen that there is no problem in evaporation of urea droplets, and they can evaporate smoothly and undergo thermal decomposition.
[0040] Depend on Figure 6-Figure 9 It can be seen that the mixer produces strong turbulence on the flue gas and ammonia, which is conducive to the mixing of ammonia and nitrogen oxides.
[0041] Depend on Figure 10-12 It can be seen that the mixer can fully mix ammonia and nitrogen oxides. Example
[0042] See also Figure 13-Figure 21 The performance test of the mixer used in Example 3 under 75% working conditions was carried out according to the urea spray test, the flue gas flow line test, the ammonia flow line test, the velocity and temperature distribution test of the central section of the mixer, and the molar ratio distribution of ammonia and ammonia nitrogen.
[0043] Depend on Figure 13-14 It can be seen that there is no problem in evaporation of urea droplets, and they can evaporate smoothly and undergo thermal decomposition.
[0044] Depend on Figures 15-18 It can be seen that the mixer produces strong turbulence on the flue gas and ammonia, which is conducive to the mixing of ammonia and nitrogen oxides.
[0045] Depend on Figures 19-21It can be seen that the mixer can fully mix ammonia and nitrogen oxides. Example
[0046] See also Figures 22-30 The performance test of the mixer used in Example 3 under 50% working conditions was carried out according to the urea spray test, the flue gas flow line test, the ammonia flow line test, the velocity and temperature distribution test of the central section of the mixer, and the molar ratio distribution of ammonia and ammonia nitrogen.
[0047] Depend on Figure 22-23 It can be seen that there is no problem in evaporation of urea droplets, and they can evaporate smoothly and undergo thermal decomposition.
[0048] Depend on Figure 24-27 It can be seen that the mixer produces strong turbulence on the flue gas and ammonia, which is conducive to the mixing of ammonia and nitrogen oxides.
[0049] Depend on Figures 28-30 It can be seen that the mixer can fully mix ammonia and nitrogen oxides.
[0050] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.
[0051] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
Claims
1. A static gas mixer, assembled into a mixing pipe, characterized in that: It comprises guide plates (110), wherein the guide plates (110) are staggered and spliced in an inclined manner, and the outer edges of the integral structure obtained by splicing the guide plates (110) are kept in engagement with the inner wall of the mixing pipe.
2. A static gas mixer according to claim 1, characterized in that: The overall structure obtained by splicing the guide plates (110) appears in a scissor-like shape in a radial perspective of the mixing pipe.
3. A static gas mixer according to claim 1, characterized in that: It also includes a reinforcing rod (120), the reinforcing rod (120) being connected to the cross-connected portion of the guide plate (110), and the end of the reinforcing rod (120) being engaged with the inner wall of the mixing pipe.
4. A static gas mixer according to claim 3, characterized in that: The guide plate (110) and the reinforcing rod (120) are both made of 304 stainless steel.
5. A static gas mixer according to claim 3, characterized in that: The reinforcing rod (120) adopts a solid rod structure or a hollow tube structure.
6. A static gas mixer according to claim 1, characterized in that: The included angle between the guide plate (110) and the axis of the mixing pipe is set to 45° or 135°.
7. The static gas mixer according to claim 1, characterized in that: The guide plates (110) that are at two angles to the axis of the mixing pipe are arranged alternately in the axial direction of the mixing pipe.
8. The static gas mixer according to claim 1, characterized in that: The guide plates (110) arranged in a scissor-like manner are arranged in an odd number of layers, and two adjacent groups of guide plates (110) in the same layer are arranged in a staggered manner, with the guide plates (110) in the central layer being located at the axis of the mixing pipe.
9. The static gas mixer according to claim 1, characterized in that: The guide plates (110) arranged in a scissor-like manner are provided in three layers, and the number of guide plates (110) in the central layer is 10 groups in total.