Ammonia-air mixing equipment for SCR denitration

Abstract

The utility model discloses a kind of ammonia air mixing equipment for SCR denitration, including mixer barrel, two groups of flow guide structure and mixing structure;Two groups of flow guide structure are respectively located at the both ends inside mixer barrel, each group of flow guide structure includes multiple flow guide baffles, multiple flow guide baffles are set along the axial direction of mixer barrel, and the adjacent two flow guide baffles are respectively set on the opposite inner wall of mixer barrel, the surface of flow guide baffle is configured as continuous corrugated shape;Mixing structure includes the axial setting of first-stage mixing unit and secondary mixing unit along mixer barrel, and first-stage mixing unit and secondary mixing unit all include multiple mixing baffles, multiple mixing baffles are arranged in circumferential array on the inner wall of mixer barrel, multiple mixing baffles of first-stage mixing unit are inclined to center along airflow direction, and multiple mixing baffles of secondary mixing unit are inclined to outside along airflow direction, so the utility model can realize that ammonia gas and air are fully mixed.

Description

Technical Field

[0001] This application relates to the field of gas mixing equipment technology, and more particularly to an ammonia-air mixing equipment for SCR denitrification. Background Technology

[0002] The main function of ammonia-air mixing equipment is to uniformly mix ammonia and air in a certain proportion, ensuring that ammonia and air are fully mixed, avoiding excessively high or low local concentrations of the ammonia-air mixture, ensuring reaction efficiency, reducing system ammonia consumption and ammonia escape. It is used in industry and power production, and is especially widely used in boiler SCR denitrification devices.

[0003] Existing ammonia-air mixing equipment includes a mixing pipe and a turbulence mechanism; the turbulence mechanism includes a turbulence shaft and multiple turbulence blades, wherein the turbulence shaft is rotatably installed inside the mixing pipe, and the turbulence blades are installed on the turbulence shaft. The turbulence blades are usually blade-shaped or columnar. When the turbulence shaft rotates, it drives the turbulence blades to move and generates airflow turbulence, thereby mixing ammonia and air.

[0004] In existing ammonia mixers, if the gas flow rate fluctuates significantly during the initial gas flow, the residence time of the gas within the mixer will be inconsistent, resulting in uneven mixing. Utility Model Content

[0005] This application provides an ammonia-air mixing device for SCR denitrification, which solves the problem of uneven gas mixing caused by large fluctuations in the flow rate before and after mixing ammonia and air in existing ammonia-air mixing devices.

[0006] This utility model embodiment provides an ammonia-air mixing device for SCR denitrification, including a mixer cylinder, characterized in that it further includes:

[0007] Two sets of flow guiding structures are located at both ends inside the mixer cylinder. Each set of flow guiding structures includes multiple flow guiding baffles that are perpendicular to the inner wall of the mixer cylinder. The multiple flow guiding baffles are arranged along the axial direction of the mixer cylinder, and two adjacent flow guiding baffles are respectively arranged on opposite inner walls of the mixer cylinder. The surface of the flow guiding baffles is configured as a continuous corrugation, and the corrugations are arranged along the radial direction of the mixer cylinder.

[0008] The mixing structure is located between two sets of flow guiding structures. The mixing structure includes a primary mixing unit and a secondary mixing unit arranged along the axial direction of the mixer cylinder. Both the primary and secondary mixing units include multiple mixing baffles. The multiple mixing baffles are arranged in a circumferential array on the inner wall of the mixer cylinder. The multiple mixing baffles that make up the primary mixing unit are inclined towards the center along the airflow direction, and the multiple mixing baffles that make up the secondary mixing unit are inclined outward along the airflow direction.

[0009] Preferably, the distance between the crests and troughs of the flow guide baffle is 25mm-30mm.

[0010] Preferably, one side of the flow guide baffle is configured with an arc-shaped side that matches the inner wall of the mixer cylinder, the arc of which is a superior arc, and the flow guide baffle is fixedly connected to the mixer cylinder through the arc-shaped side, while the other side of the flow guide baffle is configured as a straight side.

[0011] Preferably, a wavy notch extending along the length of the straight side is provided on the straight side.

[0012] Preferably, each flow guiding structure includes 2-4 flow guiding baffles.

[0013] Preferably, the distance between the crests of two adjacent guide baffles is 90mm-100mm.

[0014] Preferably, both the primary mixing unit and the secondary mixing unit include 3-4 mixing baffles, and the mixing baffles on the primary mixing unit and the secondary mixing unit are arranged in a one-to-one correspondence.

[0015] Preferably, the mixing structure is provided in 2-4 groups, and the multiple groups of mixing structures are arranged sequentially along the axial direction of the mixer cylinder.

[0016] Preferably, the mixing baffle is a circular perforated plate, and each mixing baffle is fixed to the inner wall of the mixer cylinder by a mixing baffle bracket. The angle between each mixing baffle and the center line of the mixer cylinder is 55°-60°.

[0017] Preferably, the distance between the centers of two adjacent mixing baffles along the axial direction of the mixer cylinder is 390mm-400mm.

[0018] The beneficial effects of this utility model are:

[0019] This invention relates to an ammonia-air mixing device for SCR denitrification. When mixing ammonia and air, the ammonia and air entering the mixer cylinder first pass through a first set of guide structures composed of multiple guide baffles. Because these guide baffles are staggered along the axial direction of the mixer cylinder and have corrugated surfaces, when the gas velocity at the inlet fluctuates significantly, the guide baffles can change the airflow direction. Furthermore, the corrugated design of the guide baffles increases the contact area and contact time between the gas and the baffles, inducing more vortex motion and increasing turbulence. This increased turbulence helps disperse the unevenness of the gas velocity, making the airflow more stable. Therefore, the buffering effect of the first set of guide structures helps to disperse and slow down the upstream and downstream velocities. The gas, after being buffered once, passes through the primary and secondary mixing units in sequence. Because the multiple mixing baffles constituting the primary mixing unit are inclined towards the center, they can guide the airflow to converge and increase the turbulence. The mixing baffles constituting the secondary mixing unit are inclined outward, which helps to diffuse the airflow and further increase the turbulence. After the convergence and diffusion of the primary and secondary mixing units, the gas can achieve more uniform mixing in a shorter process. When the mixed gas passes through the second set of guiding structures composed of multiple cross-flow baffles again, it can disperse and reduce the influence of the front and rear velocity fluctuations. Therefore, the ammonia-air mixing equipment for SCR denitrification disclosed in this utility model can avoid the problem of uneven mixing when the front and rear flow velocities of the gas fluctuate greatly. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments of this utility model or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This utility model relates to an ammonia-air mixing device for SCR denitrification;

[0022] Figure 2 This is a schematic diagram of the flow guide baffle.

[0023] Figure 3 for Figure 1 Cross-sectional view of AA.

[0024] Icons: 1. Mixer interface; 2. Mixer body; 3. Flow guide baffle; 4. Mixing baffle; 5. Mixing baffle bracket. Detailed Implementation

[0025] 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, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0026] This utility model provides an ammonia-air mixing device for SCR denitrification, such as... Figures 1-3 As shown, the mixer includes: a mixer cylinder 2, two sets of flow guiding structures, a mixing structure, and a mixer interface 1. The mixer interface 1 is located at the air inlet end of the mixer cylinder 2. The two sets of flow guiding structures are located at both ends inside the mixer cylinder 2. Each set of flow guiding structures includes multiple flow guiding baffles 3 arranged perpendicular to the inner wall of the mixer cylinder 2. The multiple flow guiding baffles 3 are arranged along the axial direction of the mixer cylinder 2, and two adjacent flow guiding baffles 3 are respectively arranged on opposite inner walls of the mixer cylinder 2. The surface of the flow guiding baffles 3 is configured as a continuous corrugated shape, and the corrugations are arranged along the radial direction of the mixer cylinder 2. The mixing structure is located between the two sets of flow guiding structures. The mixing structure includes a primary mixing unit and a secondary mixing unit arranged along the axial direction of the mixer cylinder 2. Both the primary mixing unit and the secondary mixing unit include multiple mixing baffles 4. The multiple mixing baffles 4 are arranged in a circumferential array on the inner wall of the mixer cylinder 2. The multiple mixing baffles 4 forming the primary mixing unit are inclined towards the center along the airflow direction, and the multiple mixing baffles 4 forming the secondary mixing unit are inclined outward along the airflow direction.

[0027] The SCR denitrification ammonia-air mixing device disclosed in this utility model, when mixing ammonia and air, the ammonia and air entering the mixer cylinder 2 first pass through a first set of guiding structures composed of multiple guide baffles 3. Because the multiple guide baffles 3 are staggered along the axial direction of the mixer cylinder 2 and because the surface of the guide baffles 3 is corrugated, when the gas velocity at the inlet end fluctuates significantly, the guide baffles 3 can, on the one hand, change the airflow direction, and on the other hand, the corrugated design on the guide baffles 3 increases the contact area and contact time between the gas and the guide baffles 3, inducing more vortex motion and increasing turbulence. The increased turbulence helps to disperse the unevenness of the gas velocity, making the airflow more stable. Therefore, the buffering effect of the first set of guiding structures helps to disperse and mitigate... The gas, after being buffered once, passes through the primary mixing unit and the secondary mixing unit in sequence. Because the multiple mixing baffles 4 constituting the primary mixing unit are inclined towards the center, they can guide the airflow to converge and increase the turbulence. The mixing baffles in the secondary mixing unit are inclined outward, which helps to diffuse the airflow and further increase the turbulence. After the convergence and diffusion of the primary and secondary mixing units, the gas can achieve more uniform mixing in a shorter process. When the mixed gas passes through the second set of guiding structures composed of multiple cross-flow baffles 3 again, it can disperse and reduce the influence of the front and rear flow velocity fluctuations again. Therefore, the ammonia-air mixing equipment for SCR denitrification disclosed in this utility model can avoid the problem of uneven mixing when the front and rear flow velocities of the gas are greatly fluctuated.

[0028] When gas flows over a corrugated surface, the alternation between crests and troughs disrupts the laminar flow of the gas, making it easier to form turbulence. In this embodiment, the distance between the crests and troughs of the guide baffle 3 is 25mm-30mm. Multiple experiments have shown that when the distance between the crests and troughs of the guide baffle 3 is 25mm-30mm, it can effectively disperse and mitigate the impact of gas flow velocity fluctuations, thereby helping to improve the overall performance of the mixing equipment.

[0029] To facilitate the installation of the guide vane 3 on the inner wall of the mixer cylinder 2, the guide baffle 3 disclosed in this embodiment is configured with an arc-shaped side that matches the inner wall of the mixer cylinder 2 on one side. The arc shape of the arc-shaped side is a superior arc. The guide baffle 3 is fixedly connected to the mixer cylinder 2 through the arc-shaped side. The other side of the guide baffle 3 is configured as a straight side. When the gas passes through the straight side of the guide baffle 3, the gas flow direction can be guided, thereby achieving effective gas diversion.

[0030] Furthermore, the straight side disclosed in this embodiment is provided with a wavy notch extending along the length direction of the straight side. On the one hand, the wavy notch can guide the flow of gas. On the other hand, the shape and arrangement of the wavy notch can divide the gas into multiple small streams when passing through the notch. These small streams collide and mix with each other in the subsequent flow process, thereby promoting the uniform mixing of the gas.

[0031] Generally, each flow guiding structure contains 2-4 flow guiding baffles 3. In this embodiment, the preferred number of flow guiding baffles is 2. After multiple experiments, it was found that when ammonia and air pass through two staggered flow guiding baffles 3, the flow velocity can be buffered and balanced.

[0032] Furthermore, the distance between the crests of two adjacent guide baffles 3 is 90mm-100mm. This distance is neither too large nor too small. An excessively large distance may cause the gas to lose its guidance during the flow process, while an excessively small distance may increase flow resistance and affect mixing efficiency. After multiple tests, in this embodiment, the preferred distance between the two guide baffles 3 is 100mm. In addition, the crest of the first guide baffle 3 on the first guide structure is 50mm from the front end interface of the mixer cylinder 2. This distance can provide sufficient buffer time, which can reduce the possibility of the gas directly impacting the guide baffle 3, thereby avoiding local high-speed flow or turbulence, and allowing the mixed gas to enter the guide area more smoothly. In addition, the last guide baffle 11 on the second set of guide structures is 50mm from the rear end interface of the mixer cylinder 2. Similarly, this distance provides another buffer for the gas. This buffer can reduce the impact of the gas on the guide baffle 11 when leaving the mixer cylinder 2, ensuring that the gas can leave the mixer cylinder 2 smoothly.

[0033] To achieve thorough gas mixing, both the primary and secondary mixing units disclosed in this embodiment include 3-4 mixing baffles 4, preferably 4, with each baffle 4 corresponding to the first and second-level mixing units. The presence of 3-4 mixing baffles ensures multi-point disturbance across the cross-section of the mixer cylinder 2, thus more comprehensively influencing the airflow and preventing insufficient mixing in localized areas. Furthermore, the four mixing baffles 4 form the primary and secondary mixing units, effectively converging and diffusing the gas. The one-to-one correspondence between the mixing baffles in the primary and secondary mixing units ensures that the gas, after passing through the primary mixing unit and entering the secondary mixing unit, is again disturbed by the mixing baffles 4 at the same location, creating a dual disturbance effect. This further enhances the turbulence and mixing effect of the airflow, resulting in more uniform gas mixing under the combined action of the primary and secondary mixing units.

[0034] Furthermore, the mixing structure disclosed in this embodiment is provided with 2-4 sets, and multiple sets of mixing structures are arranged sequentially along the axial direction of the mixer cylinder 2. The sequential arrangement of multiple sets of mixing structures along the axial direction of the mixer cylinder extends the flow path of the mixed gas, allowing more time for the mixed gas to mix as it travels along the longer path, thus improving the thoroughness of mixing.

[0035] In this embodiment, the mixing baffle 4 is fixed to the inner wall of the mixer cylinder 2 by a mixing baffle bracket 5, the length of which is 50mm. The mixing baffle 4 is a circular perforated plate with a diameter of 70mm. Each mixing baffle 4 has an angle of 55°-60° with the center line of the mixer cylinder 2. In this embodiment, the preferred angle between the mixing baffle 4 and the center line of the mixer cylinder 2 is 60°. This inclined design of the mixing baffle 4 allows the airflow to be divided into multiple small streams when passing through the pores of the circular perforated plate. Moreover, when the airflow passes through the first-stage mixing unit, it is guided by the mixing baffle 4 inclined towards the center and generates a convergence effect, causing the gas to concentrate and initially mix in the central region. Subsequently, in the second-stage mixing unit, the mixing baffle 4 inclined outward further divides and diffuses the converged airflow, forming a wider mixing area. This method of guiding the airflow to first converge and then diffuse, combined with the characteristics of the perforated plate, enables the airflow to achieve uniform mixing when passing through the mixing structure.

[0036] The distance between the centers of two adjacent mixing baffles 4 along the axial direction of the mixer cylinder 2 is 390mm-400mm. This distance provides sufficient mixing space for the gas. Between adjacent mixing baffles 4, the gas has enough space to mix, diffuse, and redistribute, thereby ensuring the full progress of the mixing process. The distance between the center of the mixing baffle 4 and its guide baffle 3 is 190mm-200mm. This distance provides a smooth path for the gas to transition from the guide zone to the mixing zone. In this embodiment, the distance between the centers of the two sets of mixing baffles 4 is preferably 400mm, and the distance between the centers of adjacent guide baffles 3 and mixing baffles 4 is 200mm.

[0037] In summary, this utility model discloses an ammonia-air mixing device for SCR denitrification. When mixing ammonia and air, the ammonia and air entering the mixer cylinder 2 first pass through a first set of guiding structures composed of multiple guide baffles 3. Because the multiple guide baffles 3 are staggered along the axial direction of the mixer cylinder 2 and because the surface of the guide baffles 3 is corrugated, when the gas velocity at the inlet fluctuates significantly, the guide baffles 3 can change the airflow direction. Furthermore, the corrugated design of the guide baffles 3 increases the contact area and contact time between the gas and the guide baffles 3, inducing more vortex motion and increasing turbulence. The increased turbulence helps to disperse the non-uniformity of the gas velocity, making the airflow more stable. Therefore, the buffering effect of the first set of guiding structures helps to disperse and mitigate the impact of velocity fluctuations. After this buffering, the gas sequentially passes through a primary mixing unit and a secondary mixing unit. Because the multiple mixing baffles 4 constituting the primary mixing unit are inclined towards the center, they can guide the airflow to converge and increase turbulence. The mixing baffles constituting the secondary mixing unit are inclined outward, which helps to diffuse the airflow and further increase turbulence. After the convergence and diffusion of the primary and secondary mixing units, the gas can achieve more uniform mixing in a shorter flow path. When the mixed gas passes through the second set of guiding structures composed of multiple cross-flow baffles 3 again, it can disperse and reduce the influence of the front and rear flow velocity fluctuations. Therefore, the ammonia-air mixing equipment for SCR denitrification disclosed in this utility model can avoid the problem of uneven mixing when the flow velocity of the gas before and after the input is greatly fluctuated. The ammonia-air mixing equipment for SCR denitrification disclosed in this utility model has the advantages of uniform ammonia-air mixing, reduced ammonia consumption for SCR denitrification, and stable operation. At the same time, the equipment has a simple structure, is a static mixing equipment, has high safety, and is highly practical.

[0038] In the description of the embodiments of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the embodiments of this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0039] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0040] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. An ammonia-air mixing device for SCR denitrification, comprising a mixer cylinder (2), characterized in that, Also includes: Two sets of flow guiding structures are located at both ends inside the mixer cylinder (2). Each set of flow guiding structures includes multiple flow guiding baffles (3) arranged perpendicular to the inner wall of the mixer cylinder (2). The multiple flow guiding baffles (3) are arranged along the axial direction of the mixer cylinder (2), and two adjacent flow guiding baffles (3) are respectively arranged on the opposite inner walls of the mixer cylinder (2). The surface of the flow guiding baffles (3) is configured as a continuous corrugated shape, and the corrugations are arranged along the radial direction of the mixer cylinder (2). A mixing structure is disposed between the two sets of the flow guiding structures. The mixing structure includes a primary mixing unit and a secondary mixing unit disposed along the axial direction of the mixer cylinder (2). Both the primary mixing unit and the secondary mixing unit include multiple mixing baffles (4). The multiple mixing baffles (4) are arranged in a circumferential array on the inner wall of the mixer cylinder (2). The multiple mixing baffles (4) constituting the primary mixing unit are inclined towards the center along the airflow direction, and the multiple mixing baffles (4) constituting the secondary mixing unit are inclined outward along the airflow direction.

2. The ammonia-air mixing equipment for SCR denitrification according to claim 1, characterized in that, The distance between the crest and trough of the flow guide baffle (3) is 25mm-30mm.

3. The ammonia-air mixing equipment for SCR denitrification according to claim 2, characterized in that, The flow guide baffle (3) has an arc-shaped side that matches the inner wall of the mixer cylinder (2) on one side. The arc shape of the arc-shaped side is a superior arc. The flow guide baffle (3) is fixedly connected to the mixer cylinder (2) through the arc-shaped side. The other side of the flow guide baffle (3) is configured as a straight side.

4. The ammonia-air mixing equipment for SCR denitrification according to claim 3, characterized in that, The straight side is provided with a wavy notch extending along the length direction of the straight side.

5. The ammonia-air mixing equipment for SCR denitrification according to claim 3, characterized in that, Each group of the flow guiding structure includes 2-4 flow guiding baffles (3).

6. The ammonia-air mixing equipment for SCR denitrification according to claim 5, characterized in that, The distance between the crests of two adjacent flow guide baffles (3) is 90mm-100mm.

7. The ammonia-air mixing equipment for SCR denitrification according to claim 1, characterized in that, Both the primary mixing unit and the secondary mixing unit contain 3-4 mixing baffles (4), and the mixing baffles (4) on the primary mixing unit and the secondary mixing unit are arranged in a one-to-one correspondence.

8. The ammonia-air mixing equipment for SCR denitrification according to claim 7, characterized in that, The mixing structure is provided in 2-4 groups, and multiple groups of the mixing structure are arranged sequentially along the axial direction of the mixer cylinder (2).

9. An ammonia-air mixing device for SCR denitrification according to claim 8, characterized in that, The mixing baffle (4) is a circular perforated plate. Each mixing baffle (4) is fixed to the inner wall of the mixer cylinder (2) by a mixing baffle bracket (5). The angle between each mixing baffle (4) and the center line of the mixer cylinder (2) is 55°-60°.

10. An ammonia-air mixing device for SCR denitrification according to claim 8, characterized in that, The distance between the centers of two adjacent mixing baffles (4) along the axial direction of the mixer cylinder (2) is 390mm-400mm.

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