Novel SCR (Selective Catalytic Reduction) catalyst front-end mixing turbulent flow device

Abstract

The utility model provides a novel SCR (Selective Catalytic Reduction) catalyst front-end mixing turbulent flow device which comprises a cylinder body, a cyclone pipe is vertically arranged in the cylinder body, a plurality of diversion trenches are arranged on the side wall of the cyclone pipe, 8-16 diversion plates are obliquely arranged on the side walls of the diversion trenches, and the 8-16 diversion plates are annularly distributed on the side wall of the cyclone pipe; the length of the flow guide plate is 60-200 mm, and the width of the flow guide groove is 6-20 mm; a silk screen is installed in the bottom end of the cylinder body, and a spoiler is welded to the side wall of the bottom end of the cylinder body. The novel SCR catalyst front-end mixing turbulent flow device provided by the utility model has the advantages that urea liquid drops can be fully crushed, and the urea liquid drops and tail gas can be conveniently and uniformly mixed.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a novel SCR catalyst front end mixing and turbulence device. Background Art

[0002] Particulate matter and harmful gases in automobile exhaust will pollute the air and cause a decline in air quality. With the continuous upgrading of emission regulations, the requirements for exhaust pollutants are becoming more and more stringent, resulting in higher and higher requirements for exhaust after-treatment performance.

[0003] In the process of exhaust gas treatment, SCR catalysts are often used. Their working principle is to spray a reducing agent (such as ammonia or urea) into the exhaust gas containing NOx. Under the action of the catalyst, NOx and the reducing agent react to produce harmless nitrogen and water. Before the exhaust gas enters the SCR catalyst, the exhaust gas needs to be evenly mixed with urea liquid. However, when the existing mixer mixes the exhaust gas and urea, urea droplets are directly sprayed into the exhaust gas. The diameter of the urea droplets is too large, making it difficult to mix quickly with the exhaust gas. In addition, the large diameter causes the urea droplets to not fully absorb heat for thermal decomposition, which will cause crystallization inside the mixer, increasing the risk of mixer clogging. It will also affect the efficiency of the SCR catalyst, thereby causing emissions to exceed the standard.

[0004] Therefore, it is necessary to provide a new type of SCR catalyst front end mixing and turbulence device to solve the above problems. Utility Model Content

[0005] The technical problem solved by the utility model is to provide a novel SCR catalyst front end mixing and turbulence device which can fully break up urea droplets and facilitate uniform mixing of urea droplets and tail gas.

[0006] In order to solve the above technical problems, the new SCR catalyst front-end mixing and spoiler device provided by the present invention includes: a cylinder, a vortex tube is vertically installed inside the cylinder, the side wall of the vortex tube is provided with multiple guide grooves, and the side walls of the guide grooves are obliquely installed with guide plates, 8 to 16 of the guide plates are distributed in a ring shape on the side walls of the vortex tube; the length of the guide plate is 60 to 200 mm, and the width of the guide groove is 6 to 20 mm; a wire mesh is installed inside the bottom end of the cylinder, and a spoiler is welded to the bottom end side wall of the cylinder.

[0007] Preferably, a urea nozzle mounting seat is welded to the side wall of the cylinder, and the urea nozzle mounting seat is communicated with the interior of the swirl tube.

[0008] Preferably, both ends of the cylinder are funnel-shaped.

[0009] Preferably, the top side wall of the swirl tube is provided with 2 to 6 grooves, and the grooves are located between the guide groove and the urea nozzle mounting seat.

[0010] Preferably, a second cover plate is installed at the top end of the vortex tube, and a first cover plate is installed at the bottom end of the vortex tube. The first cover plate and the second cover plate are located on both sides of the vortex tube, and the first cover plate and the second cover plate are installed inside the cylinder.

[0011] Preferably, the outer diameter of the wire mesh is 60 to 300 mm, the thickness of the wire mesh is 15 to 40 mm, and the wire diameter of the wire mesh is 0.22±0.02 mm.

[0012] Preferably, a plurality of through holes are provided on the surface of the spoiler, and the through holes are funnel-shaped.

[0013] Compared with related technologies, the novel SCR catalyst front end mixing and spoiling device provided by the present invention has the following beneficial effects:

[0014] The utility model provides a novel SCR catalyst front-end mixing and spoiling device, wherein both ends of the cylinder are funnel-shaped, so that the cylinder is convenient for close cooperation with the front and rear end covers of the SCR catalyst, so that the cylinder forms a sealed airflow cavity, which is convenient for sufficient mixing of exhaust gas and urea; the wire mesh is installed at the bottom end of the cylinder, and when urea droplets contact the wire mesh, the droplets will be broken and the urea can be fully heat-exchanged with the outside world, thereby improving the thermal decomposition performance of urea, effectively avoiding the risk of urea crystallization blocking post-treatment, having strong anti-crystallization performance, and being adaptable to different types of engines; the outer diameter of the wire mesh is 60 to 300 mm, and the large diameter of the wire mesh increases the contact area between the two, making it convenient for exhaust gas and urea to pass through the wire mesh, so that the overall exhaust back pressure is low; and the exhaust gas passing through the wire mesh contacts the spoiler, which can effectively improve the airflow uniformity of the cylinder outlet, thereby improving the reaction efficiency of the SCR catalyst; the overall structure of the device is simple, the process is easy to form, and the economy is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a preferred embodiment of the novel SCR catalyst front-end mixing and turbulence device provided by the present utility model;

[0016] Figure 2 for Figure 1 The schematic diagram of the cylinder outlet end structure is shown;

[0017] Figure 3 for Figure 1 Schematic diagram of the internal structure of the cylinder shown.

[0018] Numbers in the figure: 1, cylinder, 2, swirl tube, 21, groove, 22, guide groove, 23, guide plate, 3, urea nozzle mounting seat, 4, first cover plate, 5, second cover plate, 6, spoiler, 61, through hole, 7, wire mesh. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and implementation examples.

[0020] See also Figure 1 、 Figure 2 and Figure 3 , Figure 1 A schematic structural diagram of a preferred embodiment of the novel SCR catalyst front-end mixing and turbulence device provided by the present utility model; Figure 2 for Figure 1 The schematic diagram of the structure of the cylinder outlet end is shown; Figure 3 for Figure 1 The schematic diagram of the internal structure of the cylinder is shown. The novel SCR catalyst front-end mixing and turbulence device comprises: a cylinder 1, a swirl tube 2 is vertically installed inside the cylinder 1, the side wall of the swirl tube 2 is provided with a plurality of guide grooves 22, and the side wall of the guide groove 22 is obliquely installed with guide plates 23, 8 to 16 of the guide plates 23 are distributed in a ring shape on the side wall of the swirl tube 2; the length of the guide plate 23 is 60 to 200 mm, and the width of the guide groove 22 is 6 to 20 mm; when the exhaust gas enters the interior of the cylinder 1 and the swirl tube 2 The exhaust gas contacts the cyclone 2 and enters the interior of the cyclone 2 through the guide groove 22 on the side wall of the cyclone 2. The guide plate 23 is installed obliquely on the surface of the guide groove 22. The exhaust gas enters the interior of the cyclone 2 along the guide plate 23. The exhaust gas rotates inside the cyclone 2. At this time, urea droplets are sprayed into the cyclone 2 and contact with the rotating exhaust gas. The rotating exhaust gas breaks up the urea droplets, reduces the volume of the droplets, facilitates the heating of the urea, and facilitates the initial and uniform mixing of the urea droplets and the exhaust gas.

[0021] A wire mesh 7 is installed inside the bottom end of the cylinder 1. The outer diameter of the wire mesh 7 is 60 to 300 mm, the thickness of the wire mesh 7 is 15 to 40 mm, and the wire diameter of the wire mesh 7 is 0.22±0.02 mm. When urea droplets and exhaust gas contact the wire mesh 7, the droplets will be broken by the wire mesh 7. At the same time, the urea can fully exchange heat with the outside world, thereby improving the thermal decomposition performance of urea, effectively avoiding the risk of urea crystallization clogging post-processing, having strong anti-crystallization performance, and being adaptable to different types of engines.

[0022] A spoiler 6 is welded to the side wall of the bottom end of the cylinder 1, and the shortest distance between the spoiler 6 and the cyclone tube 2 is 0 to 50 mm; a plurality of through holes 61 are provided on the surface of the spoiler 6, and the through holes 61 are funnel-shaped. The exhaust gas discharged from the inside of the cyclone tube 2 contacts the spoiler 6, and the exhaust gas passes through the through holes 61 and is discharged, which can effectively improve the airflow uniformity of the exhaust gas from the cylinder 1; and the through holes 61 are funnel-shaped, so that the exhaust gas is re-converged and accelerated through the through holes 61, which helps to evenly mix the exhaust gas and urea again and facilitates the exhaust gas to quickly pass through the through holes 61.

[0023] A urea nozzle mounting seat 3 is welded to the side wall of the cylinder 1, and the urea nozzle mounting seat 3 is communicated with the interior of the vortex tube 2. In order to facilitate fixing the urea nozzle on the surface of the urea nozzle mounting seat 3, urea enters the interior of the vortex tube 2 through the urea nozzle.

[0024] Both ends of the cylinder 1 are funnel-shaped, which facilitates the close fit between the cylinder and the front and rear end covers of the SCR catalyst.

[0025] The top side wall of the swirl tube 2 is provided with 2 to 6 grooves 21, and the grooves 21 are located between the guide groove 22 and the urea nozzle mounting seat 3. The grooves 21 connect the swirl tube 2 with the interior of the cylinder 1, avoiding the risk of crystallization caused by airflow vortex at the urea nozzle mounting seat 3.

[0026] A second cover plate 5 is installed at the top end of the cyclone tube 2, and a first cover plate 4 is installed at the bottom end of the cyclone tube 2. The first cover plate 4 and the second cover plate 5 are located on both sides of the cyclone tube 2, and the first cover plate 4 and the second cover plate 5 are installed inside the cylinder 1. The first cover plate 4 allows the exhaust gas inside the cylinder 1 to enter the interior of the cyclone tube 2 through the guide groove 22, and the second cover plate 5 allows the exhaust gas and urea inside the cyclone tube 2 to be discharged through the bottom end of the cyclone tube 2. The front end of the cyclone tube 2 is sealed by the first cover plate 4, and the rear end is sealed by the second cover plate 5. In this way, the cyclone tube 2 can be ensured to be a sealed airflow cavity, and the mixed airflow can only flow out through the wire mesh 7.

[0027] The working principle of the novel SCR catalyst front-end mixing and turbulence device provided by the present invention is as follows: the exhaust gas enters the interior of the cylinder 1 and contacts the swirl tube 2, enters the interior of the swirl tube 2 through the guide groove 22 on the side wall of the swirl tube 2, and the guide plate 23 is installed obliquely on the surface of the guide groove 22, and the exhaust gas enters the interior of the swirl tube 2 along the guide plate 23. The exhaust gas rotates inside the swirl tube 2. At this time, urea droplets are sprayed into the interior of the swirl tube 2 and contact with the rotating exhaust gas. The rotating exhaust gas breaks up the urea droplets. Reducing the volume of the droplets facilitates the heating of urea and facilitates the preliminary uniform mixing of the urea droplets and the exhaust gas; after the urea droplets and the exhaust gas are mixed, they continue to move upward and contact the wire mesh 7, where the droplets will be broken by the wire mesh 7. At the same time, the urea can fully exchange heat with the outside world, thereby improving the thermal decomposition performance of urea, effectively avoiding the risk of urea crystallization blocking post-processing, and having strong anti-crystallization performance; the exhaust gas passes through the wire mesh 7 and is discharged, contacts the spoiler 6, and passes through the through hole 61 and is discharged into the interior of the SCR catalyst, which can effectively improve the airflow uniformity of the exhaust gas from the cylinder 1.

[0028] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A new type of SCR catalyst front end mixing and turbulence device, characterized in that: include: A cylinder (1), wherein a swirl tube (2) is vertically installed inside the cylinder (1), a side wall of the swirl tube (2) is provided with a plurality of guide grooves (22), and guide plates (23) are obliquely installed on the side walls of the guide grooves (22), and 8 to 16 guide plates (23) are distributed in an annular shape on the side walls of the swirl tube (2); the length of the guide plates (23) is 60 to 200 mm, and the width of the guide grooves (22) is 6 to 20 mm; A wire mesh (7) is installed inside the bottom end of the cylinder (1), and a spoiler (6) is welded to the side wall of the bottom end of the cylinder (1).

2. The novel SCR catalyst front end mixing and spoiling device according to claim 1 is characterized in that: A urea nozzle mounting seat (3) is welded to the side wall of the cylinder (1), and the urea nozzle mounting seat (3) is in communication with the interior of the swirl tube (2).

3. The novel SCR catalyst front end mixing and spoiling device according to claim 1 is characterized in that: Both ends of the cylinder (1) are funnel-shaped structures.

4. The novel SCR catalyst front end mixing and spoiling device according to claim 2 is characterized in that: The top side wall of the swirl tube (2) is provided with 2 to 6 grooves (21), and the grooves (21) are located between the guide groove (22) and the urea nozzle mounting seat (3).

5. The novel SCR catalyst front end mixing and spoiling device according to claim 1 is characterized in that: A second cover plate (5) is installed at the top end of the cyclone tube (2), and a first cover plate (4) is installed at the bottom end of the cyclone tube (2). The first cover plate (4) and the second cover plate (5) are located on both sides of the cyclone tube (2), and the first cover plate (4) and the second cover plate (5) are installed inside the cylinder (1).

6. The novel SCR catalyst front end mixing and spoiling device according to claim 1 is characterized in that: The outer diameter of the wire mesh (7) is 60 to 300 mm, the thickness of the wire mesh (7) is 15 to 40 mm, and the wire diameter of the wire mesh (7) is 0.22±0.02 mm.

7. The novel SCR catalyst front end mixing and spoiling device according to claim 1 is characterized in that: The surface of the spoiler (6) is provided with a plurality of through holes (61), and the through holes (61) are in a funnel-shaped structure.

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