Three-way catalyst

Abstract

The invention discloses a three-way catalytic converter which comprises a shell, an air inlet passage is arranged in the center of the shell, an annular filler area is arranged on the outer side of the air inlet passage, a plurality of mounting frames are inserted into the filler area, ceramic fillers are mounted on the mounting frames, vent holes are formed between the filler area and the air inlet passage, one end of the air inlet passage is connected with an air inlet pipe, and the other end of the air inlet passage is connected with an air outlet pipe. The other end of the air inlet passage is communicated with one end of the filler area through a switch valve, the other end of the filler area is connected with one end of an annular exhaust area arranged on the outer side of the filler area, and the other end of the exhaust area is connected with an exhaust pipe. The defects in the prior art can be overcome, and emission of tail gas pollutants is reduced.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology, and in particular to a three-way catalytic converter. Background Technology

[0002] To reduce the pollutant content in exhaust emissions from gasoline-powered vehicles, all existing gasoline-powered cars are equipped with three-way catalytic converters. These converters work by using fillers coated with precious metals to convert harmful gases into harmless ones at high temperatures, thus purifying exhaust gases. However, after a vehicle has been idle for an extended period and is then started, the temperature of the three-way catalytic converter is far below its normal operating temperature. This results in the catalytic converter being essentially inactive or operating at low efficiency for a period after the vehicle is started, preventing the complete conversion and decomposition of exhaust pollutants. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a three-way catalytic converter that can overcome the shortcomings of the prior art, accelerate the heating rate of the three-way catalytic converter, and reduce exhaust pollutant emissions.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows.

[0005] A three-way catalytic converter includes a housing with an intake passage at its center and an annular packing area on the outer side of the intake passage. Several mounting brackets are inserted into the packing area, and ceramic packing is installed on the mounting brackets. A vent is provided between the packing area and the intake passage. One end of the intake passage is connected to an intake pipe, and the other end of the intake passage is connected to one end of the packing area through a switching valve. The other end of the packing area is connected to one end of an annular exhaust area located outside the packing area, and the other end of the exhaust area is connected to an exhaust pipe.

[0006] Preferably, the housing comprises several housings assembled together, with at least one mounting bracket inserted into each housing.

[0007] Preferably, a partition made of thermal bimetallic sheet is provided between the filling zone and the exhaust zone via a flexible spring sheet.

[0008] Preferably, the ceramic filler has several void areas on the side near the vent, and the surface area of ​​the void areas is 3-4 cm². 2 The height of the cavity is 0.5 to 2 mm, and the distance between adjacent cavities is greater than 2 mm.

[0009] Preferably, the height of the cavity area gradually decreases from the side closer to the switch valve to the side closer to the partition. Several metal heat-conducting plates are inserted into the ceramic packing. One end of the metal heat-conducting plate is inserted into the cavity area, and the other end of the metal heat-conducting plate is attached to the inner wall of the air intake passage. The end of the metal heat-conducting plate located in the cavity area is tilted towards the side closer to the switch valve.

[0010] Preferably, the diameter of the vent hole communicating with the cavity area is larger than the diameter of other vent holes, and the axial direction of the vent hole communicating with the cavity area is parallel to the metal heat-conducting sheet.

[0011] Preferably, a heat insulation layer is provided on the outside of the exhaust zone.

[0012] The beneficial effects of adopting the above technical solution are as follows: the invention has a simple structure and high durability. Compared with traditional three-way catalytic converters, the cost increase is less than 5%. Under the premise of reasonable cost and durability control, it effectively improves the packing heating process and reduces exhaust pollutant emissions during the initial ignition stage. Attached Figure Description

[0013] Figure 1 This is a structural diagram of a specific embodiment of the present invention.

[0014] Figure 2 This is a radial sectional view of the outer casing in a specific embodiment of the present invention.

[0015] Figure 3 This is a partial enlarged view of the cavity area in a specific embodiment of the present invention.

[0016] In the diagram: 1. Outer shell; 2. Intake passage; 3. Packing area; 4. Mounting bracket; 5. Ceramic packing; 6. Vent hole; 7. Intake pipe; 8. Switch valve; 9. Exhaust area; 10. Exhaust pipe; 11. Shell; 12. Partition; 13. Cavity area; 14. Metal heat-conducting plate; 15. Insulation layer; 16. Flexible spring; 17. Narrow section. Detailed Implementation

[0017] Reference Figure 1-3 One specific embodiment of the present invention includes a housing 1. An air intake passage 2 is centrally located on the housing 1. An annular packing area 3 is located outside the air intake passage 2. Several mounting brackets 4 are inserted into the packing area 3, and ceramic packing 5 is mounted on the mounting brackets 4. A vent hole 6 is provided between the packing area 3 and the air intake passage 2. One end of the air intake passage 2 is connected to an air intake pipe 7, and the other end of the air intake passage 2 is connected to one end of the packing area 3 via a switching valve 8. The other end of the packing area 3 is connected to one end of an annular exhaust area 9 located outside the packing area 3, and the other end of the exhaust area 9 is connected to an exhaust pipe 10. A bimetallic strip partition 12 is provided between the packing area 3 and the exhaust area 9 via a flexible spring 16. Several cavities 13 are provided on the side of the ceramic packing 5 near the vent hole 6, and the surface area of ​​the cavities 13 is 3-4 cm². 2 The height of the cavity 13 is 0.5 to 2 mm, and the distance between adjacent cavity 13 is greater than 2 mm.

[0018] During idling after ignition, the switch valve 8 remains closed. Engine exhaust enters the intake passage 2 through the intake pipe 7, then enters the packing zone 3 through the vent 6, passes through the baffle 12 into the exhaust zone 9, and finally exits through the exhaust pipe 10. This exhaust path allows the packing zone to fully absorb exhaust heat, increasing the temperature rise rate of the packing zone. When the packing temperature rises to the operating temperature or the exhaust flow increases to the set threshold, the switch valve 8 is opened, and exhaust gas enters the packing zone 3 from the intake passage 2 through the switch valve 8. Simultaneously, as the gas flow rate in the packing zone 3 increases, some exhaust gas enters the packing zone 3 through the vent 6. The two gas flows are fully mixed in the packing zone 3, improving the decomposition and conversion efficiency of pollutants by the precious metal carrier.

[0019] A constriction section 17 is provided at the mounting location of the baffle 12. As the temperature rises, the baffle 12 bends, causing the edge of the baffle 12 to gradually move away from the constriction section 17. This increases the gap between the edge of the baffle 12 and the constriction section 17, thereby improving exhaust efficiency. The baffle 12 can automatically change the cross-sectional area of ​​the passage according to temperature changes, thus adapting to the exhaust flow rate requirements under different operating conditions.

[0020] The inclusion of void zone 13 allows the airflow to diffuse freely after entering the packing zone, improving the uniformity of exhaust gas distribution within the packing zone 3. Simultaneously, when two airflows converge in void zone 13, they can form localized interactive flow patterns in different void zones 13, thereby increasing the total contact area between the airflow and the packing material per unit time and enhancing the decomposition and conversion effect.

[0021] The height of the cavity zone 13 gradually decreases from the side closer to the switch valve 8 to the side closer to the partition 12. Several metal heat-conducting fins 14 are inserted into the ceramic packing 5. One end of each metal heat-conducting fin 14 is inserted into the cavity zone 13, and the other end is attached to the inner wall of the air intake passage 2. The end of the metal heat-conducting fin 14 located in the cavity zone 13 is inclined towards the side closer to the switch valve 8. The diameter of the vent 6 communicating with the cavity zone 13 is larger than the diameter of other vent 6, and the axial direction of the vent 6 communicating with the cavity zone 13 is parallel to the metal heat-conducting fins 14. The airflow flows from the higher end to the lower end, increasing the flow velocity within the cavity zone 13, thereby allowing the airflow below the cavity zone 13 to effectively enter the cavity zone 13 through the vent 6. The metal heat-conducting plate 14 directly conducts the exhaust temperature to the packing zone 3, increasing the heating rate of the packing zone. In addition, the metal heat-conducting plate 14 can form a turbulent zone at the top of the void zone 13, improving the contact efficiency between the packing and the airflow, while avoiding excessive turbulence at the bottom of the void zone 13, ensuring the efficiency of the airflow through the vent 6.

[0022] A heat insulation layer 15 is provided on the outside of the exhaust zone 9 to ensure the working temperature of the packing and to prevent burns to personnel during maintenance.

[0023] The outer casing 1 consists of two assembled shells 11, with two mounting brackets 4 inserted into each shell 11. The assembled outer casing facilitates the installation and maintenance of the filler.

[0024] In the description of this invention, it should be understood that the terms longitudinal, transverse, up, down, front, back, left, right, vertical, horizontal, top, bottom, inside, outside, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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. Therefore, they should not be construed as limitations on this invention.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A three-way catalytic converter, comprising a housing (1), characterized in that: The outer shell (1) has an air intake passage (2) at its center. An annular packing area (3) is provided on the outside of the air intake passage (2). Several mounting brackets (4) are inserted into the packing area (3). Ceramic packing (5) is installed on the mounting brackets (4). A vent hole (6) is provided between the packing area (3) and the air intake passage (2). One end of the air intake passage (2) is connected to an air intake pipe (7). The other end of the air intake passage (2) is connected to one end of the packing area (3) through a switch valve (8). The other end of the packing area (3) is connected to one end of an annular exhaust area (9) located on the outside of the packing area (3). The other end of the exhaust area (9) is connected to an exhaust pipe (10).

2. The three-way catalytic converter according to claim 1, characterized in that: The outer shell (1) comprises several shells (11) assembled together, and each shell (11) has at least one mounting bracket (4) inserted into it.

3. The three-way catalytic converter according to claim 1, characterized in that: A thermoplastic bimetallic strip partition (12) is provided between the packing zone (3) and the exhaust zone (9) via a flexible spring sheet (16).

4. The three-way catalytic converter according to claim 3, characterized in that: The ceramic filler (5) has several void areas (13) on the side near the vent (6), and the surface area of ​​the void areas (13) is 3-4 cm². 2 The height of the cavity (13) is 0.5 to 2 mm, and the distance between adjacent cavities (13) is greater than 2 mm.

5. The three-way catalytic converter according to claim 4, characterized in that: The height of the cavity area (13) gradually decreases from the side closer to the switch valve (8) to the side closer to the partition (12). Several metal heat-conducting plates (14) are inserted into the ceramic packing (5). One end of the metal heat-conducting plate (14) is inserted into the cavity area (13), and the other end of the metal heat-conducting plate (14) is attached to the inner wall of the air intake passage (2). The end of the metal heat-conducting plate (14) located in the cavity area (13) is tilted towards the side closer to the switch valve (8).

6. The three-way catalytic converter according to claim 5, characterized in that: The diameter of the vent (6) connected to the cavity area (13) is larger than the diameter of the other vents (6), and the axial direction of the vent (6) connected to the cavity area (13) is parallel to the metal heat-conducting plate (14).

7. The three-way catalytic converter according to claim 1, characterized in that: A heat insulation layer (15) is provided on the outside of the exhaust zone (9).

Images