Ammonia gas mixer device

Abstract

The utility model belongs to the technical field of diesel engine tail gas after-treatment, and particularly relates to an ammonia gas mixer device. The ammonia gas mixer device comprises a mixer, the gas inlet end of the mixer is connected with the gas outlet end of a DOC assembly, the gas inlet end of the DOC assembly is connected with a gas inlet end cone, the gas inlet end cone is provided with a gas inlet flange, the gas outlet end of the mixer is connected with the gas inlet end of an SDPF assembly, and the gas outlet end of the SDPF assembly is connected with a gas outlet end cone; an ejector, a rotational flow pipe and a special-shaped pore plate are arranged at the upper part of the mixer, the rotational flow pipe and the special-shaped pore plate are sequentially arranged between the DOC assembly and the SDPF assembly, the ejector is communicated with the rotational flow pipe, and a flow guide crushing plate is arranged at the bottom of the rotational flow pipe. The inclined holes are formed in the special-shaped pore plate in the ammonia gas mixer device, so that the flowing state of air flow can be adjusted, ammonia gas in a dead zone can be taken away to enter the SDPF assembly, the crystallization risk is reduced, and pressure relief, back pressure reduction and oil consumption reduction can be realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of diesel engine exhaust after-treatment, and particularly relates to an ammonia mixer device. Background Technique

[0002] The urea selective catalytic reduction technology is a key technology that can effectively reduce the NOx emissions of diesel engines. However, during the operation of this system, it is affected by factors such as the diesel engine working conditions, ambient temperature, and the properties of the urea aqueous solution itself. The urea aqueous solution cannot be completely evaporated and pyrolyzed, and will adhere to the device wall to form crystals. If urea crystals are generated, it will affect the working state of the entire after-treatment system, resulting in problems such as a decrease in NOx conversion efficiency and ammonia leakage. In severe cases, it may even block the exhaust pipe, leading to an increase in exhaust back pressure, thereby increasing diesel engine fuel consumption.

[0003] Limited by the boundary conditions, the layout space of the mixer structure is limited. When arranging the DOC component and the SDPF component, there will be an included angle and a small distance. The axis of the orifice plate of the mixer is offset by 6.8 mm from the central axis of the SDPF component. The conventional orifice plate structure results in an air flow dead zone at the position on the inlet side of the SDPF component ( Figure 1 enclosed by the red dotted line), generating urea crystals, affecting the service life, reducing the uniformity of ammonia mixing, affecting the efficiency of the SDPF component, resulting in unqualified tail gas emissions. In addition, the back pressure increases and the fuel consumption rate rises, affecting the performance of the diesel engine. Content of the Utility Model

[0004] The purpose of the utility model is to overcome the deficiencies existing in the prior art and provide an ammonia mixer device. The special-shaped orifice plate structure of the ammonia mixer device of the utility model can prevent local crystallization caused by boundary limitations under low-temperature and low-flow conditions, improve the ammonia mixing uniformity and eccentricity at the inlet of the SDPF component, improve the SDPF efficiency, reduce the risk of urea crystallization, extend the service life, reduce the back pressure of the post-processor, and improve the engine performance.

[0005] To achieve the above technical purposes, the technical solution adopted in the embodiment of the utility model is:

[0006] An ammonia mixer device, comprising a mixer. The intake end of the mixer is connected to the outlet end of the DOC component. An intake end cone is connected to the intake end of the DOC component, and an intake flange is arranged on the intake end cone. The outlet end of the mixer is connected to the intake end of the SDPF component, and an outlet end cone is connected to the outlet end of the SDPF component;

[0007] An ejector, a cyclone tube, and a special-shaped orifice plate are provided at the upper part of the mixer. The cyclone tube and the special-shaped orifice plate are sequentially arranged between the DOC component and the SDPF component. The ejector is communicated with the cyclone tube, and a diversion and fragmentation plate is arranged at the bottom of the cyclone tube.

[0008] Further, an included angle of 95°-110° is formed between the axes of the DOC component and the SDPF component.

[0009] Further, the distance d between the axis of the special-shaped orifice plate and the axis of the SDPF component is 6.5-7.5 mm.

[0010] Further, inclined holes are uniformly formed in the special-shaped orifice plate. The inclined holes are close to the DOC component and far from the cyclone tube. The included angle α between the axis of the inclined hole and the axis of the special-shaped orifice plate is 30-40°;

[0011] The distribution diameter Ф2 of the centers of the upper surfaces of the inclined holes is (0.85-0.95)D, where D is the diameter of the special-shaped orifice plate.

[0012] Further, the diameter Ф1 of the inclined hole is 2.5-3.5 mm, the number of the inclined holes is 5, and the included angle β between the centers of the upper surfaces of adjacent inclined holes is 20-40°.

[0013] The special-shaped orifice plate is further provided with large flanging blades, small flanging blades, and air holes. The large flanging blades are arranged on the outer periphery of the small flanging blades, and the inclined holes are arranged on the outer periphery of the large flanging blades;

[0014] A circle of air holes is uniformly distributed between the large flanging blades and the small flanging blades and between the large flanging blades and the inclined holes;

[0015] The flanging directions of the large flanging blades and the small flanging blades are the same as the air flow direction.

[0016] The beneficial effects brought by the technical solution provided by the embodiment of the present invention are as follows:

[0017] (1) In the ammonia mixer device of the present invention, inclined holes are provided on the special-shaped orifice plate. The inclined holes are close to the axis of the SDPF component. The inclined holes of the special-shaped orifice plate can be used to adjust the air flow state, take away the ammonia in the dead zone and enter the SDPF, reduce the crystallization risk, and improve the SDPF efficiency.

[0018] (2) The ammonia mixer device of the present invention can use the inclined holes on the special-shaped orifice plate to relieve pressure, reduce the back pressure, reduce the fuel consumption, and improve the engine performance. Brief Description of the Drawings

[0019] Figure 1This is a schematic structural diagram of the ammonia mixer device in the embodiment of the present utility model.

[0020] Figure 2 It is Figure 1 a schematic structural diagram of the distance between the axis of the special-shaped orifice plate and the axis of the SDPF assembly in

[0021] Figure 3 a schematic structural diagram of a conventional special-shaped orifice plate in the prior art.

[0022] Figure 4 This is a schematic structural diagram of the special-shaped orifice plate of the present utility model.

[0023] Explanation of reference numerals: 1 - intake flange; 2 - intake end cone; 3 - DOC assembly; 4 - mixer; 5 - injector; 6 - swirl tube; 7 - deflector breaker plate; 8 - special-shaped orifice plate; 81 - inclined hole; 82 - large flanging blade; 83 - small flanging blade; 84 - air hole; 9 - SDPF assembly; 10 - outlet end cone; 11 - outer cylinder of DOC assembly; 12 - outer cylinder of SDPF assembly; 13 - axis of special-shaped orifice plate; 14 - axis of SDPF assembly; 15 - axis of inclined hole. Detailed implementation manners

[0024] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by orientation words such as "inside, outside", "up, down", "left, right", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as limiting the protection scope of the present utility model.

[0025] In order to make the purpose, technical solution and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0026] Embodiment 1

[0027] As Figure 1 shown, an ammonia mixer device includes a mixer 4. The intake end of the mixer 4 is connected to the outlet end of the DOC assembly 3. The intake end of the DOC assembly 3 is connected with an intake end cone 2, and an intake flange 1 is arranged on the intake end cone 2. The outlet end of the mixer 4 is connected to the intake end of the SDPF assembly 9, and the outlet end of the SDPF assembly 9 is connected with an outlet end cone 10;

[0028] The upper part of the mixer 4 is provided with an injector 5, a swirl tube 6 and a special-shaped orifice plate 8. The swirl tube 6 and the special-shaped orifice plate 8 are sequentially arranged between the DOC component 3 and the SDPF component 9. The injector 5 is communicated with the swirl tube 6, and a flow guiding and crushing plate 7 is arranged at the bottom of the swirl tube 6.

[0029] Specifically, the intake end cone 2, the outer shell of the mixer 4 are connected to the outer cylinder 11 of the DOC component. The injector 5 is inserted into the mixer 4. The swirl tube 6 is welded to the outer shell of the mixer 4. The flow guiding and crushing plate 7 is welded to the swirl tube 6. The special-shaped orifice plate 8 is welded to the inner wall surface of the mixer 4. The outer shell of the mixer 4 and the outlet end cone 2 are welded to the outer cylinder 12 of the SDPF component.

[0030] The axes of the DOC component 3 and the SDPF component 9 form an angle of 95° - 110°.

[0031] As Figure 2 shown, the distance d between the axis of the special-shaped orifice plate 8 and the axis of the SDPF component 9 is 6.5 - 7.5 mm.

[0032] As shown in Figure 4, inclined holes 81 are evenly arranged on the special-shaped orifice plate 8. The inclined holes 81 are close to the DOC component 3 and far from the swirl tube 6. The angle α between the axis 15 of the inclined hole and the axis 13 of the special-shaped orifice plate is 30° - 40°;

[0033] The distribution diameter Ф2 of the centers of the upper surfaces of the inclined holes 81 = (0.85 - 0.95)D, where D is the diameter of the special-shaped orifice plate 8.

[0034] The diameter Ф1 of the inclined holes 81 is 2.5 - 3.5 mm, the number of the inclined holes 81 is 5, and the angle β between the centers of the upper surfaces of adjacent inclined holes 81 is 20° - 40°.

[0035] The special-shaped orifice plate 8 is also provided with large flanging blades 82, small flanging blades 83 and air holes 84. The large flanging blades 82 are arranged on the outer periphery of the small flanging blades 83, and the inclined holes 81 are arranged on the outer periphery of the large flanging blades 82;

[0036] A circle of air holes 84 are evenly distributed between the large flanging blades 82 and the small flanging blades 83 and between the large flanging blades 82 and the inclined holes 81;

[0037] The flanging directions of the large flanging blades 82 and the small flanging blades 83 are the same as the air flow direction.

[0038] The gas enters the mixer 4 through the DOC component 3 via the intake end cone 2. In the mixer 4, after the injector 5 injects urea, the flow guide and fragmentation plate 7 conducts preliminary fragmentation on it. The airflow passes through the cyclone tube 6 and the flow guide and fragmentation plate 7 to organize the airflow to drive the fragmented urea mixture towards the special-shaped orifice plate 8. The special-shaped orifice plate 8 conducts secondary fragmentation on the mixture and further organizes the airflow to drive the mixture towards the SDPF component 9. Limited by the layout space, the axis 13 of the special-shaped orifice plate does not coincide with the axis 14 of the SDPF component, and the distance between the two is d (as Figure 2 shown). Affected by this, in the position (as Figure 3 shown) circled in red at the entrance of the SDPF component for the conventional orifice plate structure (as Figure 1 shown), there is no gas flow, resulting in urea crystallization and high back pressure. The special-shaped orifice plate 8 of the present utility model is provided with inclined holes 81 (as Figure 4 shown) according to the airflow direction at the position where the airflow dead zone is generated, that is, close to the DOC component 3 and away from the side where the cyclone tube 6 is located. The axis 15, layout method and dimensions of the inclined holes meet the above requirements, which can organize the airflow to pass through, reduce the crystallization risk and reduce the back pressure.

[0039] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present utility model, and they should all be covered within the scope of the claims of the present utility model.

Claims

1. An ammonia mixer device, characterized in that, It includes a mixer (4), the intake end of the mixer (4) is connected to the outlet end of the DOC component (3), the intake end of the DOC component (3) is connected with an intake end cone (2), an intake flange (1) is arranged on the intake end cone (2), the outlet end of the mixer (4) is connected to the intake end of the SDPF component (9), and the outlet end of the SDPF component (9) is connected with an outlet end cone (10); An injector (5), a swirl tube (6) and a special-shaped orifice plate (8) are arranged on the upper part of the mixer (4), the swirl tube (6) and the special-shaped orifice plate (8) are sequentially arranged between the DOC component (3) and the SDPF component (9), the injector (5) is communicated with the swirl tube (6), and a flow guiding and breaking plate (7) is arranged at the bottom of the swirl tube (6).

2. The ammonia mixer device according to claim 1, characterized in that, The axis of the DOC component (3) forms an angle of 95° - 110° with the axis of the SDPF component (9).

3. The ammonia mixer device according to claim 1, wherein, The distance d between the axis of the special-shaped orifice plate (8) and the axis of the SDPF component (9) is 6.5 - 7.5 mm.

4. The ammonia mixer device according to claim 1, characterized in that, Oblique holes (81) are evenly arranged on the special-shaped orifice plate (8), the oblique holes (81) are close to the DOC component (3) and far away from the swirl tube (6), and the angle α between the axis of the oblique holes (81) and the axis of the special-shaped orifice plate (8) is 30 - 40°; The distribution diameter Ф2 of the centers of the upper surfaces of the oblique holes (81) = (0.85 - 0.95)D, where D is the diameter of the special-shaped orifice plate (8).

5. The ammonia mixer device according to claim 1, characterized in that, The diameter Ф1 of the oblique holes (81) is 2.5 - 3.5 mm, the number of the oblique holes (81) is 5, and the angle β between the centers of the upper surfaces of adjacent oblique holes (81) is 20 - 40°.

6. The ammonia mixer device according to claim 4, characterized in that, Large flanging blades (82), small flanging blades (83) and air holes (84) are also arranged on the special-shaped orifice plate (8), the large flanging blades (82) are arranged on the outer periphery of the small flanging blades (83), and the oblique holes (81) are arranged on the outer periphery of the large flanging blades (82); A circle of air holes (84) is evenly distributed between the large flanging blades (82) and the small flanging blades (83) and between the large flanging blades (82) and the oblique holes (81); The flanging directions of the large flanging blades (82) and the small flanging blades (83) are the same as the air flow direction.

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