Urea mixer with heating fins

Abstract

The application provides a urea mixer with heating pieces, which comprises a cylinder and a nozzle base arranged on the outer wall of the cylinder, the nozzle base is used for fixing and mounting a urea nozzle, the urea nozzle is communicated with the inside of the cylinder, the inside of the cylinder is provided with a mixer pipe, a heating assembly and a flow guide plate, the mixer pipe is communicated with the urea nozzle, the upper end of the mixer pipe is connected with the inner wall of the cylinder, the lower end penetrates through the flow guide plate, the heating assembly is arranged below the mixer pipe and is used for heating the urea from the mixer pipe, a plurality of flange blades and openings are arranged on the pipe wall of the mixer pipe, and exhaust gas flows into the mixer pipe from the inlet under the guidance of the flow guide plate. The urea mixer with heating pieces has the advantages of good urea distribution uniformity, low crystallization of urea, uniform distribution of urea on the end face of the SCR carrier, uniform mixing of exhaust gas and ammonia gas, high-efficiency and stable work of the SCR, small size and low back pressure.

Description

A urea mixer with heating element Technical Field

[0001] This invention belongs to the field of diesel vehicle exhaust aftertreatment technology, and relates to an exhaust aftertreatment urea mixing device, especially a urea mixer with heating elements. Background Technology

[0002] In diesel engine exhaust aftertreatment systems, selective catalytic reduction (SCR) technology is commonly used to reduce the NOx content in the exhaust gas. SCR involves injecting a urea solution into the exhaust aftertreatment mixer. Under the action of a catalyst, nitrogen oxides (NOx) in the exhaust gas are reduced into harmless nitrogen (N2) and water (H2O), thus reducing emissions. However, existing urea mixing devices often suffer from poor urea mixing uniformity, easily forming urea crystals, resulting in high back pressure, which affects the performance of the aftertreatment system. In more severe cases, it can even cause excessive emissions or blockages in the aftertreatment system, leading to insufficient vehicle power. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a urea mixer with a heating element. This urea mixer with a heating element exhibits good urea distribution uniformity, prevents urea crystallization, and ensures that urea is evenly distributed on the SCR carrier end face, resulting in uniform mixing of exhaust gas and ammonia, and ensuring efficient and stable SCR operation. Simultaneously, this urea mixer has the advantages of small size and low back pressure, better meeting the stringent boundary requirements of vehicle packaging structures.

[0004] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows:

[0005] A urea mixer with a heating element includes a cylinder and a nozzle base disposed on the outer wall of the cylinder. The nozzle base is used to fix and install a urea nozzle, and the urea nozzle communicates with the interior of the cylinder.

[0006] The cylinder is equipped with a mixer tube, a heating assembly, and a guide plate. The mixer tube is connected to the urea nozzle. The upper end of the mixer tube is connected to the inner wall of the cylinder, and the lower end passes through the guide plate. The heating assembly is located below the mixer tube and is used to heat the urea from the mixer tube.

[0007] The mixer tube has several flanged blades and openings on its tube wall, and the exhaust gas flows into the mixer tube from the inlet under the guidance of the guide plate.

[0008] Furthermore, the nozzle base is fixed to the cylinder by a fixing base and a patch. The fixing base is used to ensure the setting angle of the nozzle base so that urea can be sprayed vertically downward into the inside of the mixer tube.

[0009] Furthermore, the guide plate is integrally formed and includes a first vertical part, a second vertical part and an intermediate connecting part located between the two. The lower end of the mixer tube passes through the intermediate connecting part and extends to the space between the intermediate connecting part and the cylinder.

[0010] The lower end of the first vertical part is connected to the cylinder body, and there is an air inlet between the lower end of the first vertical part and the cylinder body. The upper end of the first vertical part is connected to one end of the intermediate connecting part, the other end of the intermediate connecting part is connected to the lower end of the second vertical part, and the upper end of the second vertical part is connected to the cylinder body.

[0011] Furthermore, the heating assembly includes a heating plate and an airflow baffle. The airflow baffle is connected to the cylinder body, and the heating plate is disposed between the airflow baffle and the first vertical part. The heating plate is provided with a plurality of heating elements.

[0012] Furthermore, the airflow baffle is provided with several adjustment holes, and the airflow baffle and adjustment holes cooperate to adjust the airflow rate of the exhaust airflow entering the lower surface of the heating element from the air inlet.

[0013] Furthermore, the heating element is disposed on the lower surface of the heating plate, and the heating element is V-shaped or U-shaped.

[0014] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0015] 1. The urea mixer with heating element of the present invention is used in a single-tube type aftertreatment structure and has the advantages of low exhaust back pressure and small size.

[0016] 2. The urea mixer with heating element of this invention has high mixing efficiency, good ammonia mixing performance, and strong anti-crystallization ability.

[0017] 3. The urea mixer with heating element of the present invention improves the crystallization problem at the urea landing point by setting up the heating element assembly. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the structure of a urea mixer with heating elements in an embodiment of the present invention.

[0019] Figure 2 is a schematic diagram of the structure of the inlet end of the urea mixer with heating element shown in Figure 1.

[0020] Figure 3 is a schematic diagram of the internal structure of the urea mixer with heating elements shown in Figure 1.

[0021] Figure 4 is a schematic diagram of the V-shaped heating element of the urea mixer with heating element shown in Figure 1.

[0022] Figure 5 is a schematic diagram of the structure of the U-shaped heating element of the urea mixer with heating element shown in Figure 1.

[0023] Explanation of reference numerals in the attached drawings: 1-Cylinder body; 2-Patch; 3-Nozzle base; 4-Fixed base; 5-Mixer tube; 6-Heating assembly; 7-First vertical part; 8-Second vertical part; 5-1-Flanged blade; 5-2-Opening; 6-1-Heating plate; 6-2-Heating element; 6-3-Airflow baffle; 6-4-Adjustment hole; 7-1-Air inlet. Detailed Implementation

[0024] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention.

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] Example 1

[0027] As shown in Figures 1-3, a urea mixer with a heating element includes a cylinder 1 and a nozzle base 3 disposed on the outer wall of the cylinder 1. The nozzle base 3 is used to fix and install a urea nozzle, and the urea nozzle is in communication with the interior of the cylinder 1.

[0028] The interior of the cylinder 1 is provided with a mixer tube 5, a heating component 6 and a guide plate. The mixer tube 5 is connected to the urea nozzle. The upper end of the mixer tube 5 is connected to the inner wall of the cylinder 1 and the lower end passes through the guide plate. The heating component is located below the mixer tube 5 and is used to heat the urea from the mixer tube 5.

[0029] The mixer tube 5 has several flanged blades 5-1 and openings 5-2 on its tube wall. The exhaust gas flow enters the mixer tube 5 from the inlet 5-2 under the guidance of the guide plate.

[0030] The rotating blades 5-1 rotate uniformly inwards towards the inside of the mixer tube 5, and are evenly arranged on the mixer tube 5. The rotating blades 5-1 and the mixer tube 5 form an opening 5-2, through which the airflow enters the interior of the mixer tube 5. The evenly arranged rotating blades 5-1 and the opening 5-2 guide the airflow evenly into the interior of the mixer tube 5. Under the turbulence effect of the rotating blades 5-1, the mixing of exhaust gas and urea is more uniform.

[0031] The nozzle base 3 is fixed to the cylinder 1 by the fixing base 4 and the patch 2. The fixing base 4 is used to ensure the setting angle of the nozzle base 3 so that the urea can be sprayed vertically downward into the mixer tube 5.

[0032] The guide plate is integrally formed and includes a first vertical part 7, a second vertical part 8 and an intermediate connecting part located between the two. The lower end of the mixer tube 5 passes through the intermediate connecting part and extends to the space between the intermediate connecting part and the cylinder 1.

[0033] The lower end of the first vertical part 7 is connected to the cylinder 1, and there is an air inlet 7-1 between the lower end of the first vertical part 7 and the cylinder 1. The upper end of the first vertical part 7 is connected to one end of the intermediate connecting part, and the other end of the intermediate connecting part is connected to the lower end of the second vertical part 8. The upper end of the second vertical part 8 is connected to the cylinder 1.

[0034] The heating assembly 6 includes a heating plate 6-1 and an airflow baffle 6-3. The airflow baffle 6-3 is connected to the cylinder 1. The heating plate 6-1 is disposed between the airflow baffle 6-3 and the first vertical part 7. A plurality of heating elements 6-2 are disposed on the heating plate 6-1.

[0035] Heating elements 6-2 are disposed on the lower surface of heating plate 6-1. To increase the surface area of ​​the heating surface, heating elements 6-2 are V-shaped or U-shaped, as shown in Figures 4 and 5. The more heating elements 6-2 there are, the better the heating effect on heating plate 6-1, and consequently, the better the anti-crystallization ability of heating component 6.

[0036] The airflow baffle 6-3 is provided with several adjustment holes 6-4. The airflow baffle 6-3 and the adjustment holes 6-4 work together to adjust the airflow rate of the exhaust airflow entering the lower surface of the heating element 6-2 from the air inlet 7-1.

[0037] Generally, the larger the through-hole area of ​​the regulating hole 6-4, the greater the exhaust flow rate from the air inlet 7-1 into the heating plate 6-1, and the stronger the heating effect of the exhaust on the heating plate assembly. However, this will reduce the exhaust flow rate from the opening 5-1 into the mixing pipe, reducing the mixing effect of the mixing pipe 5. Therefore, the size of the regulating hole 6-4 is determined according to the needs.

[0038] The urea mixer with heating element of the present invention is used in the exhaust treatment packaging assembly. The left side of the mixer is the air inlet end, which is connected to the rear end of the DPF, and the right side is the air outlet end, which is connected to the front end of the SCR.

[0039] The exhaust gas flows into the cylinder 1 from the left and enters the mixer tube 5 through the opening 5-2. The airflow inside the mixer tube 5 is from top to bottom. The urea solution enters the mixer tube 5 from the base 3 and moves downwards with the airflow, simultaneously affected by gravity. The urea solution then falls onto the upper surface of the heating plate 6-1 and flows out of the urea mixer from the right under the influence of the airflow. The urea mixer is mainly used for crushing urea particles, decomposing urea, and mixing urea with exhaust gas. The urea solution sprayed from the urea nozzle is injected into the urea mixer through the through-hole in the middle of the base 3. Inside the mixer, the urea solution evaporates under the heat of the exhaust gas, undergoing a pyrolysis reaction, and the urea particles gradually become smaller.

[0040] After the exhaust gas enters the mixer from the left side, most of the airflow enters the mixer tube 5 through 5-2. At the same time, some airflow enters the lower surface of the heating element 6-2 through the air inlet 7-1. The airflow at this point does not pass through the mixing tube 5. Its main function is to purge the heating element 6-2 and the lower surface of the heating plate 6-1. When urea falls onto the upper surface of the heating plate 6-1 through the mixing tube 5, the urea requires a certain amount of heat to evaporate and will absorb the heat of the exhaust gas during evaporation. This will cause the upper surface of the heating plate to cool down and produce urea crystals. Severe crystallization will reduce the performance of the mixer, worsen emissions, and even cause the mixer to be blocked by crystals, leading to problems such as engine stalling.

[0041] To address the aforementioned issues, this application incorporates an air inlet 7-1. The exhaust gas entering the air inlet 7-1 heats the lower surfaces of the heating element 6-2 and the heating plate 6-1. When the temperature of the upper surface of the heating plate 6-1 decreases, the heat energy from the heating element 6-2 can be promptly transferred to the heating plate 6-1, preventing urea crystallization on the upper surface of the heating plate 6-1. This improves the urea crystallization phenomenon in the urea drop area and enhances the mixer's anti-crystallization capability.

[0042] The heating element 6-2 and the heating plate 6-1 are made of materials with good thermal conductivity, such as metal plates, and the heating element is heated by the heat carried by the exhaust.

[0043] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A urea mixer with a heating element, characterized in that, The device includes a cylinder (1) and a nozzle base (3) disposed on the outer wall of the cylinder (1). The nozzle base (3) is used to fix and install a urea nozzle, which is in communication with the interior of the cylinder (1). The interior of the cylinder (1) is provided with a mixer tube (5), a heating assembly (6), and a guide plate. The mixer tube (5) is in communication with the urea nozzle. The upper end of the mixer tube (5) is connected to the inner wall of the cylinder (1), and the lower end passes through the guide plate. The heating assembly is disposed on the mixer tube (5). Below 5), urea from the mixer tube (5) is heated; the mixer tube (5) has several flanged blades (5-1) and openings (5-2) on its wall, and the exhaust gas flows into the mixer tube (5) through the openings (5-2) under the guidance of the guide plate; the heating assembly (6) includes a heating plate (6-1) and an airflow baffle (6-3), the airflow baffle (6-3) is connected to the cylinder (1), and the heating plate (6-1) is disposed on the airflow baffle (6-3). Between the heating plate (6-1) and the first vertical part (7), a plurality of heating elements (6-2) are provided on the heating plate (6-1); a plurality of adjusting holes (6-4) are provided on the airflow baffle (6-3), and the airflow baffle (6-3) and the adjusting holes (6-4) cooperate to adjust the airflow rate of the exhaust airflow entering the lower surface of the heating element (6-2) from the air inlet (7-1); the guide plate is integrally formed, including the first vertical part (7), the second vertical part (8) and the intermediate connecting part located between the two, and the mixer tube (5) The lower end of the first vertical part (7) passes through the intermediate connecting part and extends between the intermediate connecting part and the cylinder (1); the lower end of the first vertical part (7) is connected to the cylinder (1), and there is an air inlet (7-1) between the lower end of the first vertical part (7) and the cylinder (1); the upper end of the first vertical part (7) is connected to one end of the intermediate connecting part; the other end of the intermediate connecting part is connected to the lower end of the second vertical part (8); and the upper end of the second vertical part (8) is connected to the cylinder (1).

2. The urea mixer with heating element according to claim 1, characterized in that, The nozzle base (3) is fixed to the cylinder (1) by a fixing base (4) and a patch (2). The fixing base (4) is used to ensure the setting angle of the nozzle base (3) so that urea can be sprayed vertically downward into the mixer tube (5).

3. The urea mixer with heating element according to claim 1, characterized in that, The heating element (6-2) is disposed on the lower surface of the heating plate (6-1), and the heating element (6-2) is V-shaped or U-shaped.

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