Mixer for tail gas treatment

Abstract

The utility model relates to the technical field of tail gas treatment of diesel engines, in particular to a mixer for tail gas treatment, which comprises a mixing cylinder, and two gas inlets and two gas outlets are respectively arranged at the top and the bottom of the mixing cylinder. The mixing cylinder is provided with a partition plate, and the partition plate is arranged in a Z shape; the interior of the mixing barrel is divided into an air inlet cavity and an air outlet cavity by the partition plate; a communicating connecting pipe is arranged between the air inlet cavity and the air outlet cavity, and a carrier is arranged on the connecting pipe; and a urea injector facing the gas inlet cavity is arranged on the side wall of the rear part of the mixing cylinder. According to the utility model, the mixing time of tail gas and urea in the mixing cylinder can be prolonged, so that the tail gas and urea particles can be mixed more uniformly and fully, and harmful substances in the waste gas can be better treated.

Description

Technical Field

[0001] This utility model relates to the field of diesel engine exhaust gas treatment technology, and in particular to a mixer for exhaust gas treatment. Background Technology

[0002] Currently, selective catalytic reduction (SCR) technology is commonly used in diesel engine exhaust aftertreatment systems to treat engine exhaust emissions. A urea solution is injected into the exhaust aftertreatment mixing device, where it is decomposed into ammonia (NH3) at the exhaust temperature. Under the action of a catalyst, the ammonia (NH3) reduces nitrogen oxides (NOx) in the exhaust gas into harmless nitrogen (N2) and water (H2O), which are then discharged from the exhaust pipe, thereby achieving the goal of reducing emissions.

[0003] However, when existing mixers mix exhaust gas and urea, the mixture is in a cylindrical shape, and the gas is quickly discharged after mixing. The short reaction time in the mixer results in a large amount of harmful substances in the exhaust gas not being decomposed and eliminated. Utility Model Content

[0004] To solve the above problems, this utility model provides a mixer for exhaust gas treatment, the specific technical solution of which is as follows:

[0005] A mixer for exhaust gas treatment includes a mixing cylinder with two air inlets and two air outlets at its top and bottom, respectively. The mixing cylinder is equipped with a partition arranged in a Z-shape, which divides the interior of the mixing cylinder into an air inlet chamber and an air outlet chamber. A connecting pipe is provided between the air inlet chamber and the air outlet chamber, and a carrier is provided on the connecting pipe. A urea injector facing the air inlet chamber is provided on the rear side wall of the mixing cylinder.

[0006] Furthermore, the connecting pipe has several equally spaced openings at the air intake chamber, and each opening is provided with an inclined baffle.

[0007] Furthermore, the connecting pipe is provided with several exhaust ports at the air outlet chamber.

[0008] Furthermore, an arc-shaped guide plate is provided below several exhaust ports in the air outlet chamber.

[0009] Furthermore, the two air inlets and the two air outlets are respectively equipped with upper figure-eight flanges and lower figure-eight flanges.

[0010] Furthermore, the carrier is provided in several parts, and the several carriers are arranged at equal intervals inside the connecting pipe.

[0011] Beneficial effects: In this invention, exhaust gas is delivered to the intake chamber through two air inlets. At the same time, the urea injector works to deliver urea into the intake chamber, allowing the urea to mix with the exhaust gas. The exhaust gas in the intake chamber is then delivered to the exhaust chamber through a connecting pipe. At this time, the carrier in the connecting pipe reacts with the exhaust gas, which can increase the reaction surface area, improve the gas mixing effect, and facilitate the diffusion of substances. The Z-shaped baffle can prolong the mixing time of the exhaust gas and urea in the mixing cylinder, making the exhaust gas and urea particles mix more evenly and thoroughly, and better treating the harmful substances in the exhaust gas. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 1 ;

[0013] Figure 2 This is a schematic diagram of the overall structure of this utility model. Figure 2 ;

[0014] Figure 3 This is a cross-sectional view of the present invention;

[0015] Figure 4 This is a partial three-dimensional structural schematic diagram of the present invention;

[0016] Figure 5 This is a three-dimensional structural diagram of the connecting pipe of this utility model;

[0017] Reference numerals: 1. Mixing cylinder; 10. Air inlet; 11. Air outlet; 12. Baffle; 13. Air inlet chamber; 14. Air outlet chamber; 2. Connecting pipe; 21. Opening; 22. Baffle; 23. Exhaust port; 3. Carrier; 4. Urea injector; 5. Arc-shaped guide plate; 6. Upper figure-eight flange; 7. Lower figure-eight flange. Detailed Implementation

[0018] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0019] Reference Figures 1 to 5This embodiment proposes a design for a mixer for exhaust gas treatment, including a mixing cylinder 1. The mixing cylinder 1 has two air inlets 10 and two air outlets 11 at its top and bottom, respectively. The mixing cylinder 1 is provided with a partition 12, which is arranged in a Z-shape. The partition 12 divides the mixing cylinder 1 into an air inlet chamber 13 and an air outlet chamber 14. A connecting pipe 2 is provided between the air inlet chamber 13 and the air outlet chamber 14, and a carrier 3 is provided on the connecting pipe 2. A urea injector 4 is provided on the rear side wall of the mixing cylinder 1, facing the air inlet chamber 13.

[0020] During use, exhaust gas is delivered to the intake chamber 13 through two air inlets 10. At the same time, the urea injector 4 delivers urea into the intake chamber 13, allowing the urea to mix with the exhaust gas. The exhaust gas in the intake chamber 13 is then delivered to the exhaust chamber 14 through the connecting pipe 2. At this time, the carrier 3 in the connecting pipe 2 reacts with the exhaust gas, which can increase the surface area of ​​the reaction, improve the gas mixing effect, and facilitate the diffusion of substances. The Z-shaped baffle 12 can prolong the mixing time of the exhaust gas and urea in the mixing cylinder 1, making the exhaust gas and urea particles mix more evenly and fully, and better treating the harmful substances in the exhaust gas.

[0021] Specifically, the connecting pipe 2 is provided with a number of equally spaced openings 21 at the air inlet chamber 13, and each opening 21 is provided with an inclined baffle 22.

[0022] During the reaction between exhaust gas and urea, several baffles 22 are installed at the opening 21 of the connecting pipe 2. The baffles 22 at the opening 21 of the connecting pipe 2 where exhaust gas and urea enter the reaction zone can change the flow path of exhaust gas and urea. Exhaust gas usually enters the connecting pipe 2 at a high flow rate, while the urea solution also has its own injection speed and direction. The baffles 22 can disperse these two fluids, preventing them from entering the reaction zone directly in a concentrated manner. The presence of the baffles 22 causes turbulence when the fluid passes through. The mixing process of exhaust gas and urea is more complete in the turbulent state. The turbulence can better entrain the droplets of urea solution into the exhaust gas flow. The turbulence formed in the connecting pipe 2 helps the urea and exhaust gas to be initially mixed before entering the reaction zone.

[0023] Specifically, the connecting pipe 2 is provided with a plurality of exhaust ports 23 at the air outlet chamber 14; an arc-shaped guide plate 5 is provided in the air outlet chamber 14 below the plurality of exhaust ports 23.

[0024] After reacting with the carrier 3 in the connecting pipe 2, the exhaust gas is discharged downwards through several exhaust ports 23 onto the arc-shaped guide plate 5 and then flows to the two exhaust ports 11. The arc-shaped guide plate 5 can change the flow direction of the exhaust gas. When the exhaust gas passes through the guide plate, its flow path will bend, forming vortices and turbulence. This turbulent airflow helps to better entrain the urea solution into the exhaust gas, so that the urea droplets can be more evenly distributed in the exhaust gas. By changing the flow path of the exhaust gas, the arc-shaped guide plate 5 prolongs the contact time between the exhaust gas and the urea droplets. The arc-shaped guide plate 5 can guide the exhaust gas to flow upwards, exerting an upward force on the urea droplets and preventing them from accumulating at the bottom.

[0025] Specifically, the two air inlets 10 and the two air outlets 11 are respectively provided with an upper figure-eight flange 6 and a lower figure-eight flange 7; the upper figure-eight flange 6 and the lower figure-eight flange 7 can better connect with the existing device during the docking process of the mixer, thereby fixing the mixing cylinder 1 and increasing the strength of the mixing cylinder 1.

[0026] Specifically, there are several carriers 3, and the several carriers 3 are arranged at equal intervals inside the connecting pipe 2.

[0027] Carrier 3 is a cordierite ceramic carrier. Cordierite has a low coefficient of thermal expansion, which allows it to maintain structural stability in environments with frequent changes in exhaust gas temperature. Its honeycomb structure can provide a large specific surface area, providing sufficient reaction sites for the reaction between ammonia produced by urea decomposition and nitrogen oxides in the exhaust gas.

[0028] Carrier 3 is a silicon carbide ceramic carrier: Silicon carbide (SiC) ceramic carriers possess excellent thermal conductivity and high-temperature strength. Its high thermal conductivity facilitates rapid heat transfer within carrier 3, allowing the reaction to proceed in a more uniform temperature field. During high-temperature exhaust gas treatment, the silicon carbide carrier can withstand higher temperatures and resist corrosion from chemicals in the exhaust gas, thus extending the service life of carrier 3.

[0029] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without inventive effort, and these embodiments will all fall within the protection scope of the claims of this utility model.

Claims

1. A mixer for exhaust gas treatment, characterized in that, The mixing cylinder (1) includes two air inlets (10) and two air outlets (11) at its top and bottom, respectively. The mixing cylinder (1) is provided with a partition (12) which is arranged in a Z-shape. The partition (12) divides the mixing cylinder (1) into an air inlet chamber (13) and an air outlet chamber (14). A connecting pipe (2) is provided between the air inlet chamber (13) and the air outlet chamber (14), and a carrier (3) is provided on the connecting pipe (2). A urea injector (4) facing the air inlet chamber (13) is provided on the rear side wall of the mixing cylinder (1).

2. The mixer for exhaust gas treatment according to claim 1, characterized in that: The connecting pipe (2) is provided with several equally spaced openings (21) at the air inlet chamber (13), and each opening (21) is provided with an inclined baffle (22).

3. The mixer for exhaust gas treatment according to claim 1, characterized in that: The connecting pipe (2) is provided with several exhaust ports (23) at the air outlet chamber (14).

4. A mixer for exhaust gas treatment according to claim 3, characterized in that: An arc-shaped guide plate (5) is provided in the air outlet chamber (14) below several exhaust ports (23).

5. A mixer for exhaust gas treatment according to claim 1, characterized in that: The two air inlets (10) and the two air outlets (11) are respectively provided with an upper figure-eight flange (6) and a lower figure-eight flange (7).

6. A mixer for exhaust gas treatment according to claim 1, characterized in that: The carrier (3) is provided in several parts, and the several carriers (3) are arranged at equal intervals inside the connecting pipe (2).

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