Bionic spiral guide type tail gas treatment device and treatment method for bulldozer

Abstract

The application discloses a bionic spiral flow guide type tail gas treatment device and method for a bulldozer, and belongs to the technical field of internal combustion engine tail gas aftertreatment. In view of the technical problems that the existing tail gas treatment device of the bulldozer is not uniform in air flow distribution, loses heat quickly, and is unstable in catalytic efficiency, and is difficult to adapt to the harsh working conditions of variable load, strong vibration and much dust, the application adopts a fish-like bionic coaxial integrated structure, and is provided with double Archimedes spiral fan blades with opposite rotation directions to realize uniform air flow guiding and stable pressure of the tail gas. The device is provided with a DOC and a SCR two-stage catalytic filter core matched with a composite air guide hole structure, is matched with an inner heat insulation sleeve and a buffer ring sleeve to realize efficient heat management and vibration reduction and protection, and is matched with a modular filter core and a tail gas sensing and monitoring structure. The application effectively balances the tail gas air flow and the reaction heat field, has excellent anti-vibration and anti-blocking performance, can stably realize deep purification of tail gas multi-pollutants, is convenient to operate and maintain, has strong working condition adaptability, and significantly improves the stability and economy of the tail gas emission treatment of the bulldozer.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas aftertreatment technology for internal combustion engines, and in particular to a biomimetic spiral flow-guided exhaust gas treatment device and treatment method for bulldozers. Background Technology

[0002] Bulldozers, as core non-road construction machinery in engineering construction, mining, and road construction, are generally equipped with high-power diesel engines and are characterized by heavy workloads, frequent changes in operating conditions, and harsh working environments. During actual bulldozer operation, frequent load changes cause drastic fluctuations in diesel engine exhaust flow and temperature. Simultaneously, high dust concentrations at construction sites and continuous high vibration levels place extremely high demands on the adaptability, operational stability, and durability of diesel engine exhaust aftertreatment purification devices. As the core device for controlling exhaust pollutant emissions from construction machinery, the exhaust aftertreatment system's catalytic purification efficiency, thermal management capabilities, and anti-clogging and anti-vibration performance directly determine the equipment's ability to meet emission standards and its long-term service life.

[0003] Currently, traditional bulldozer exhaust catalytic converters mostly employ a fixed, straight-through chamber structure with a simple airflow guiding structure, exhibiting significant technical shortcomings in practical use. On one hand, the uneven flow velocity distribution of exhaust gas after entering the catalytic chamber easily leads to localized airflow concentration and stagnation. This not only causes inconsistent erosion and wear on the catalyst surface but also easily results in localized carbon buildup and dust blockage, significantly reducing catalyst utilization, shortening the lifespan of the catalytic filter, and increasing equipment maintenance frequency and operating costs. On the other hand, the variable load operation of bulldozers causes large fluctuations in exhaust temperature. Traditional exhaust gas treatment devices lack efficient active thermal management structures, making it impossible to quickly raise and stabilize the catalytic reaction temperature. Under low-temperature conditions, the catalyst struggles to reach its optimal activation temperature, resulting in a significant decrease in the purification efficiency for pollutants such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust gas, making it difficult to meet stringent emission requirements for non-road machinery.

[0004] Existing related improvement technologies mostly focus on single-dimensional improvements such as catalyst formulation optimization and filter element material upgrades, generally neglecting exhaust gas flow organization optimization and integrated thermal management structure design, resulting in strong limitations in technological improvement. Existing devices cannot achieve synergistic adaptation of uniform exhaust gas guidance, stable pressure delivery, and constant temperature catalysis, and cannot adapt to the harsh operating conditions of bulldozers with large exhaust temperature fluctuations, high dust levels, and strong vibrations. They generally suffer from many problems such as unstable catalytic efficiency, rapid heat dissipation, high exhaust back pressure, easy clogging, poor vibration resistance, and inconvenient maintenance.

[0005] In summary, there is currently a lack of exhaust gas treatment devices that are suitable for the complex and harsh working conditions of bulldozers, possessing features such as uniform flow guidance, efficient thermal management, staged and precise catalysis, vibration resistance and anti-clogging, and easy modular maintenance. This makes it difficult to simultaneously meet the requirements of efficient exhaust gas purification and long-term stable operation, thus hindering the upgrading and promotion of exhaust gas purification technology for non-road construction machinery. Therefore, developing a biomimetic spiral flow guiding bulldozer exhaust gas treatment device with good thermal management, high purification efficiency, strong adaptability, and convenient maintenance is a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems in the prior art and provide a biomimetic spiral-guided exhaust gas treatment device and method for bulldozers. The device adopts a fish-like biomimetic structure, with Archimedes spiral fan blades in opposite directions to achieve uniform exhaust gas flow and stable pressure. The device uses two-stage catalytic filter elements (DOC and SCR) for graded purification, combined with an inner heat insulation sleeve for efficient thermal management, and a buffer ring to improve vibration resistance. The filter elements adopt a modular and detachable structure, effectively adapting to the harsh and fluctuating operating conditions of bulldozers, improving exhaust gas purification efficiency and facilitating maintenance.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a biomimetic spiral flow guiding exhaust gas treatment device for bulldozers, comprising an exhaust gas inlet mask, a biomimetic gas collection hood, a catalytic reaction chamber, and an exhaust gas detection section that are coaxially connected in sequence along the exhaust gas flow direction.

[0008] The biomimetic gas collection hood has a first Archimedes spiral fan blade at its front end;

[0009] The inner wall of the catalytic reaction chamber is provided with an inner heat insulation sleeve, and the inner heat insulation sleeve is provided with a primary catalytic filter and a secondary catalytic filter.

[0010] The exhaust detection section is equipped with a second Archimedes spiral fan blade, the direction of rotation of the second Archimedes spiral fan blade being opposite to that of the first Archimedes spiral fan blade.

[0011] Furthermore, the primary catalytic filter element has a cylindrical structure with several through-holes. The through-holes include spiral cylindrical through-holes and prismatic upright through-holes, which are distributed in a ring-shaped interval on the cross-section of the filter element.

[0012] The inner walls of both the spiral cylindrical air guide holes and the prismatic upright air guide holes are coated with a diesel oxidation catalyst coating. This composite air guide hole structure can effectively disturb the exhaust gas flow, increase the catalytic reaction contact area, and rapidly increase the system temperature by relying on the exothermic reaction of the diesel oxidation catalyst, thereby improving the problems of low catalytic efficiency and uneven heat field distribution during low-temperature start-up of traditional devices.

[0013] Furthermore, the secondary catalytic filter element has a cylindrical structure with several hexagonal prism-shaped air guide holes arranged in a honeycomb pattern throughout.

[0014] The inner wall of the hexagonal prism-shaped air guide hole is coated with an SCR catalyst coating. The honeycomb-shaped densely packed hexagonal prism air guide hole can further uniformize the exhaust gas flow rate, reduce exhaust back pressure, and significantly improve the contact uniformity between nitrogen oxides and catalyst, achieving deep denitrification and purification of exhaust gas, effectively solving the defects of turbulent airflow and incomplete purification in traditional devices.

[0015] Furthermore, a filter element support frame is provided between the primary catalytic filter element and the secondary catalytic filter element;

[0016] One end of the filter element support frame is fixedly connected to the primary catalytic filter element, and the other end abuts against the secondary catalytic filter element. The filter element support frame is used to support the primary and secondary catalytic filter elements to form a buffer cavity between the two filter elements. The buffer cavity can stabilize and buffer the exhaust gas, avoid sudden changes in exhaust gas flow from affecting catalytic stability, and at the same time improve the overall structural strength of the filter element, making it suitable for the harsh working conditions of bulldozers with strong vibrations.

[0017] Furthermore, a buffer ring is provided between the outer shell and the inner heat insulation sleeve of the catalytic reaction chamber;

[0018] Both the primary and secondary catalytic filter elements are modular and detachable. The buffer ring effectively absorbs vibration and impact during equipment operation, reducing fatigue damage to internal components. The modular filter element structure allows for replacement and maintenance without disassembling the entire equipment, solving the problems of cumbersome maintenance and high downtime costs associated with traditional devices.

[0019] Furthermore, it also includes catalyst support pads;

[0020] The catalyst carrier gasket is disposed at the inlet end of the primary catalytic filter and the outlet end of the secondary catalytic filter, and is used for positioning, sealing and separating the filter elements;

[0021] The catalyst carrier gasket is equipped with a sludge collection tank. The gasket ensures the installation accuracy of the filter element and the sealing of the cavity, preventing exhaust gas leakage and short circuits from affecting the purification effect. The sludge collection tank can collect purification waste liquid and impurities in a timely manner, effectively avoiding problems such as dirt accumulation and blockage, and equipment aging and failure.

[0022] Furthermore, exhaust gas detection sensors are installed on both the biomimetic gas collection hood and the exhaust detection section;

[0023] The exhaust gas detection sensor is used to monitor the concentration of particulate matter, nitrogen oxide content, and temperature parameters in the exhaust gas, and is configured to send an alarm signal to the bulldozer control system when the detected value exceeds a preset threshold. It can monitor the exhaust gas emission status and device operating conditions in real time and accurately, promptly detect faults such as filter failure and excessive exhaust gas emissions, achieve controllable equipment status, provide early warning and maintenance, and ensure long-term stable and compliant emissions.

[0024] A method for treating exhaust gas using the above-mentioned exhaust gas treatment device includes the following steps:

[0025] S1 Bionic Gas Concentration and Guiding: The exhaust gas from the bulldozer enters the bionic gas collection hood through the exhaust gas inlet mask. The streamlined bionic gas collection hood gathers the scattered exhaust gas and, together with the first Archimedes spiral fan blade, swirls and disperses the exhaust gas, guides and pressurizes it, ensuring that the exhaust gas is evenly input into the catalytic reaction chamber.

[0026] S2 First-stage catalytic oxidation: The pressurized exhaust gas enters the first-stage catalytic filter element, and the reaction area is increased by using spiral cylindrical air guide holes and prismatic vertical air guide holes. The HC and CO in the exhaust gas are oxidized by the diesel oxidation catalyst coating, and the system temperature is rapidly increased by using the exothermic oxidation reaction.

[0027] S3 Secondary Catalytic Reduction: After primary treatment, the oxygen-enriched exhaust gas is pressure-stabilized and buffered by the buffer chamber, and then enters the hexagonal prism air guide hole of the secondary catalytic filter. Under the suitable temperature environment maintained by the inner heat insulation sleeve, nitrogen oxides are reduced to N2 and H2O through the SCR catalyst coating, achieving deep purification of exhaust gas.

[0028] S4 Pressure Stabilized Exhaust: The purified gas is guided by the second Archimedes spiral fan blade, and after reducing the system back pressure, it is discharged into the atmosphere.

[0029] Furthermore, in step S2, the reaction heat generated by the primary catalytic filter element is reduced through the inner heat insulation sleeve, and the alternating distribution of spiral cylindrical air guide holes and prismatic vertical air guide holes disturbs the airflow, promoting heat exchange and ensuring a uniform overall temperature of the filter element. This effectively improves the shortcomings of traditional exhaust gas treatment devices, such as rapid heat loss and large local temperature differences, stabilizes the thermal environment of the catalytic reaction, and ensures the continuous and efficient catalytic reaction under bulldozer load variations and fluctuating exhaust temperature conditions.

[0030] Furthermore, in step S4, the exhaust gas detection sensor on the exhaust detection section monitors emission indicators in real time; when the exhaust gas fails to meet standards, the system triggers an alarm and prompts for replacement or maintenance of the primary and secondary catalytic converter filters. This achieves real-time closed-loop monitoring of exhaust gas purification effects, enabling timely detection of problems such as filter blockage and failure, avoiding long-term excessive emissions, and significantly improving the reliability and intelligent operation and maintenance level of the device.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention employs a biomimetic streamlined gas collection structure combined with dual sets of Archimedean spiral fan blades in both directions to construct a novel swirling and guiding airflow organization system. This effectively overcomes the technical defects of traditional bulldozer exhaust gas treatment devices, such as uneven airflow distribution, localized carbon buildup and blockage, and inconsistent scouring and wear. The first spiral fan blade at the front end can swirl and disperse the scattered exhaust gas, guiding and pressurizing it to ensure that the exhaust gas evenly covers the cross-section of the catalytic filter element, avoiding excessively high local flow velocities that cause rapid catalyst loss. The reverse spiral fan blade at the rear end can smoothly exhaust the purified gas, significantly reducing the system's exhaust back pressure. This structure achieves uniform exhaust gas intake and stable exhaust pressure without the need for additional power components, greatly improving airflow utilization and catalytic uniformity.

[0033] This invention employs a two-stage catalytic purification structure of DOC+SCR, combined with composite air guide holes and an integrated heat insulation structure, achieving a synergistic improvement in both thermal management and high-efficiency purification. This addresses the pain points of traditional construction machinery exhaust systems, such as slow low-temperature start-up, poor adaptability to exhaust temperature fluctuations, and unstable purification efficiency. The first-stage catalytic filter element uses a spiral and prism-alternating composite air guide hole structure, significantly increasing the exhaust gas contact area. Relying on the exothermic reaction of the diesel oxidation catalyst, it rapidly raises the system temperature. Simultaneously, the airflow disturbance balances the filter element's thermal field, and the inner heat insulation sleeve effectively reduces heat loss, providing a stable temperature foundation for subsequent reactions. The second-stage hexagonal prism honeycomb filter element structure further optimizes the airflow channel, achieving deep reduction of nitrogen oxides through the SCR catalytic reaction. This allows the device to maintain continuous, stable, and efficient exhaust gas purification capabilities even under varying loads and frequent temperature changes in bulldozers, significantly improving the overall emission control effect.

[0034] The catalytic reaction chamber is equipped with a buffer ring structure, which effectively absorbs high-frequency vibrations and mechanical shocks during equipment operation, reducing fatigue damage to internal precision components such as filter elements and gaskets, and significantly improving the device's shock resistance and service reliability. Simultaneously, both stages of the catalytic filter elements adopt a modular, detachable structure, combined with a positioning sealing gasket design with a sludge collection groove. This ensures effective chamber sealing, prevents exhaust gas leakage, and allows for timely collection of purified waste liquid and impurities, reducing clogging issues. Filter element maintenance and replacement do not require complete equipment disassembly, simplifying the maintenance process. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0036] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0037] Figure 2 A partial sectional view of the isometric side view for the invention.

[0038] Figure 3This is a top half-sectional view of the present invention.

[0039] Figure 4 This is a schematic diagram of the structure of the primary catalytic filter element in this invention.

[0040] Figure 5 This is a schematic diagram of the structure of the secondary catalytic filter element in this invention.

[0041] Figure 6 This is a side view schematic diagram of the present invention in the direction of exhaust gas entering the mask.

[0042] Figure 7 Figure (a) is a three-dimensional structural schematic diagram of the first Archimedes spiral fan blade in this invention, and Figure (b) is a top view structural schematic diagram of the first Archimedes spiral fan blade.

[0043] Figure 8 This is a schematic diagram of the structure of the catalyst support pad in this invention.

[0044] The attached diagram is labeled as follows: 1. Exhaust gas inlet mask; 2. Fixing nut; 3. Bionic gas collection hood; 4. Catalytic reaction chamber; 5. Exhaust gas detection section; 6. Exhaust gas detection sensor; 7. First Archimedes spiral fan blade; 8. Catalytic carrier gasket; 9. Primary catalytic filter element; 10. Secondary catalytic filter element; 11. Inner heat insulation sleeve; 12. Buffer ring sleeve; 13. Spiral cylindrical air guide hole; 14. Prismatic upright air guide hole; 15. Filter element support frame; 16. Hexagonal prism air guide hole; 17. Sludge collection tank; 18. Second Archimedes spiral fan blade; 19. Buffer cavity. Detailed Implementation

[0045] 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. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] like Figure 1-8 As shown, this invention discloses a biomimetic spiral-guided exhaust gas treatment device for bulldozers. The device adopts a coaxial, integrated, fish-like biomimetic structure, with an exhaust gas inlet mask 1, a biomimetic gas collection hood 3, a catalytic reaction chamber 4, and an exhaust gas detection section 5 coaxially assembled along the exhaust gas flow direction. The overall structure is compact and occupies little space, adapting to the limited chassis installation space of bulldozers. It also effectively resists dust and mud erosion at construction sites, making it suitable for harsh operating conditions. The exhaust gas inlet mask 1 has a connecting and fixing nut 2 at its end, enabling quick and precise connection with the original exhaust pipe of the bulldozer. The installation has good sealing performance, effectively preventing exhaust gas leakage and ensuring that all exhaust gas is guided into the device for purification.

[0047] The front end of the biomimetic gas collection shroud 3 is equipped with a first Archimedes spiral fan blade 7, and the exhaust detection section 5 is equipped with a second Archimedes spiral fan blade 18. The two sets of fan blades rotate in opposite directions. Through the bidirectional reverse spiral flow guiding structure, the chaotic and scattered exhaust gas during bulldozer operation can be swirled, dispersed, guided, and pressurized. This solves the problem of concentrated and uneven airflow distribution in traditional exhaust gas treatment devices, effectively avoiding defects such as catalyst erosion and wear, and local carbon buildup and blockage caused by excessively fast local airflow. It significantly improves the uniformity of exhaust gas flow, while reducing the overall exhaust back pressure and ensuring smooth engine exhaust.

[0048] The catalytic reaction chamber 4, as the core purification unit for exhaust gas, has an inner heat insulation sleeve 11 on its inner shell. This effectively blocks heat loss during the catalytic reaction, stabilizes the internal thermal field of the device, and solves the problems of rapid heat loss and low catalytic efficiency under low-temperature conditions in traditional devices. The inner heat insulation sleeve 11 is divided into two stages of catalytic chambers by a filter element support frame 15, which are respectively equipped with a primary catalytic filter element 9 and a secondary catalytic filter element 10. The primary catalytic filter element 9 adopts a composite structure with spiral cylindrical air guide holes 13 and prismatic upright air guide holes 14 arranged in annular intervals. The pore walls are coated with diesel oxidation catalyst. This diverse pore structure significantly increases the exhaust gas contact area. Simultaneously, airflow disturbance evens the overall temperature of the filter element, and the exothermic oxidation reaction rapidly raises the system operating temperature, providing a stable heat source for the downstream denitrification reaction. The secondary catalytic filter element 10 adopts a honeycomb densely packed hexagonal prism air guide hole structure 16, with the pore walls coated with SCR catalyst. This structure has good airflow, a large contact area, and high structural strength, enabling deep reduction and purification of nitrogen oxides in the exhaust gas and significantly improving the exhaust gas treatment effect.

[0049] A filter element support frame 15 is fixedly installed between the primary catalytic filter element 9 and the secondary catalytic filter element 10. This frame not only stably supports the two filter elements, preventing them from shifting or deforming under the strong vibration of a bulldozer, but also forms an independent buffer chamber 19 between the two filter elements to stabilize and buffer the exhaust gas, avoiding the impact of sudden changes in exhaust gas flow on the stability of the catalytic reaction. A buffer ring sleeve 12 is added between the outer shell of the catalytic reaction chamber 4 and the inner heat insulation sleeve 11. This effectively absorbs high-frequency vibrations and mechanical impacts during equipment operation, reducing fatigue damage to internal precision components and significantly improving the reliability and service life of the device. Furthermore, both filter elements adopt a modular and detachable structure, which, together with the catalytic carrier gasket 8 with a sludge collection tank 17, achieves a positioning seal. This ensures the airtightness of the chamber, collects purified waste liquid and impurities, reduces clogging and other problems, and allows for filter element replacement without disassembling the entire equipment, making maintenance convenient and reducing downtime costs. The exhaust gas detection sensor 6, which is equipped with the bionic gas collection hood 3 and the exhaust detection section 5, can monitor parameters such as exhaust gas pollutant concentration and temperature in real time. When the parameters exceed the standard, an alarm will be triggered in time to realize intelligent operation and maintenance monitoring.

[0050] This invention also provides a biomimetic spiral flow guiding method for treating bulldozer exhaust gas, adapted to the aforementioned exhaust gas treatment device. The specific steps are as follows: First, biomimetic gas gathering and guiding is performed. The turbulent exhaust gas discharged from the bulldozer is introduced into the biomimetic gas collection hood 3 through the exhaust gas inlet hood 1. The streamlined hood gathers the scattered airflow, and in conjunction with the first Archimedes spiral fan blade 7, it completes the swirling dispersion and guiding pressurization, so that the exhaust gas is uniformly and stably input into the catalytic reaction chamber 4. Then, the first-stage catalytic oxidation is carried out. The uniformly distributed exhaust gas flows through the first-stage catalytic filter element 9, and fully contacts the diesel oxidation catalyst through the spiral cylindrical air guide holes 13 and the prismatic upright air guide holes 14, efficiently oxidizing and decomposing HC and CO pollutants in the exhaust gas. At the same time, the oxidation exothermic heat is used to quickly increase the system temperature, and the inner heat insulation sleeve 11 continuously locks in the temperature, balancing the heat field of the filter element and avoiding excessive local temperature differences that affect the purification effect.

[0051] Next, a secondary catalytic reduction process is performed. The oxygen-enriched exhaust gas, after being heated by the primary oxidation, is evenly introduced into the secondary catalytic filter 10 after being pressure-stabilized and buffered by the buffer chamber 19. Under a stable and suitable temperature environment, the nitrogen oxides in the exhaust gas are reduced to nitrogen and water by the SCR catalyst, completing the deep purification of the exhaust gas. Finally, pressure stabilization and monitoring are implemented. The purified exhaust gas is smoothly guided out through the counter-arranged second Archimedes spiral fan blades 18, effectively reducing the system exhaust back pressure. At the same time, the exhaust gas detection sensor 6 monitors the emission indicators in real time. Once the exhaust gas exceeds the standard, the system alarm is immediately triggered, prompting the staff to maintain or replace the primary catalytic filter 9 and the secondary catalytic filter 10 in time, ensuring the long-term stable and compliant operation of the device.

[0052] In summary, this invention effectively addresses the industry pain points of traditional bulldozer exhaust gas treatment devices, such as uneven airflow, poor thermal stability, weak vibration resistance, and unstable purification efficiency, through the synergistic combination of biomimetic reverse spiral flow guidance, a two-stage catalytic structure of DOC and SCR, and an integrated heat insulation and vibration reduction structure. The overall structure is compact and rationally designed, relying on a multi-stage airflow optimization structure to improve the uniformity and stability of exhaust gas purification. The built-in heat insulation and vibration reduction structure adapts to the harsh operating conditions of bulldozers, including varying loads, strong vibrations, and high dust levels. Furthermore, the modular filter element and intelligent monitoring design balance the multiple requirements of high-efficiency purification, stable operation, and convenient maintenance, significantly improving adaptability and economic efficiency.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A biomimetic spiral-guided exhaust gas treatment device for bulldozers, characterized in that, It includes an exhaust gas inlet mask (1), a bionic gas collection hood (3), a catalytic reaction chamber (4), and an exhaust gas detection section (5) that are coaxially connected in sequence along the exhaust gas flow direction. The biomimetic gas collection hood (3) has a first Archimedes spiral fan blade (7) at its front end; The inner wall of the catalytic reaction chamber (4) is provided with an inner heat insulation sleeve (11), and the inner heat insulation sleeve (11) is provided with a primary catalytic filter (9) and a secondary catalytic filter (10). The exhaust detection section (5) is equipped with a second Archimedes spiral fan blade (18), and the direction of rotation of the second Archimedes spiral fan blade (18) is opposite to that of the first Archimedes spiral fan blade (7).

2. The bulldozer exhaust gas treatment device according to claim 1, characterized in that, The primary catalytic filter element (9) has a cylindrical structure with several through-holes. The through-holes include spiral cylindrical through-holes (13) and prismatic upright through-holes (14). The two types of through-holes are distributed in a ring-shaped interval on the cross-section of the filter element. The inner walls of the spiral cylindrical air guide hole (13) and the prismatic upright air guide hole (14) are coated with a diesel oxidation catalyst coating.

3. The bulldozer exhaust gas treatment device according to claim 2, characterized in that, The secondary catalytic filter element (10) has a cylindrical structure with several hexagonal prism-shaped air guide holes (16) arranged in a honeycomb pattern. The inner wall of the hexagonal prism-shaped air guide hole (16) is coated with an SCR catalyst coating.

4. The bulldozer exhaust gas treatment device according to claim 1, characterized in that, A filter element support frame (15) is provided between the primary catalytic filter element (9) and the secondary catalytic filter element (10). One end of the filter element support frame (15) is fixedly connected to the primary catalytic filter element (9), and the other end abuts against the secondary catalytic filter element (10). The filter element support frame (15) is used to support the primary catalytic filter element (9) and the secondary catalytic filter element (10) to form a buffer cavity (19) between the two filter elements.

5. The bulldozer exhaust gas treatment device according to claim 1, characterized in that, A buffer ring (12) is also provided between the outer shell and the inner heat insulation sleeve (11) of the catalytic reaction chamber (4). Both the primary catalytic filter element (9) and the secondary catalytic filter element (10) are modular and detachable structures.

6. The bulldozer exhaust gas treatment device according to claim 1, characterized in that, It also includes a catalyst support pad (8); The catalyst carrier gasket (8) is disposed at the inlet end of the primary catalyst filter (9) and the outlet end of the secondary catalyst filter (10) for positioning, sealing and separating the filter elements; The catalyst carrier gasket (8) is provided with a sludge collection tank (17).

7. The bulldozer exhaust gas treatment device according to claim 1, characterized in that, Both the bionic gas collection hood (1) and the exhaust detection section (5) are equipped with exhaust gas detection sensors (6). The exhaust gas detection sensor (6) is used to monitor the particulate matter concentration, nitrogen oxide content and temperature parameters in the exhaust gas, and is configured to send an alarm signal to the bulldozer control system when the detected value exceeds a preset threshold.

8. A method for treating exhaust gas using the exhaust gas treatment device according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1 Bionic gas gathering and guiding: The exhaust gas of the bulldozer enters the bionic gas collection hood (3) through the exhaust gas inlet mask (1). The streamlined bionic gas collection hood (3) gathers the scattered exhaust gas and, together with the first Archimedes spiral fan blade (7), swirls and disperses the exhaust gas, guides and pressurizes it, so as to ensure that the exhaust gas is uniformly input into the catalytic reaction chamber (4). S2 First-stage catalytic oxidation: The pressurized exhaust gas enters the first-stage catalytic filter (9), and the reaction area is increased by using the spiral cylindrical air guide hole (13) and the prismatic upright air guide hole (14). The HC and CO in the exhaust gas are oxidized by the diesel oxidation catalyst coating, and the system temperature is rapidly increased by using the exothermic oxidation reaction. S3 Secondary Catalytic Reduction: After primary treatment, the oxygen-rich exhaust gas is stabilized and buffered by the buffer chamber (19) and then enters the hexagonal prism air guide hole (16) of the secondary catalytic filter (10). Under the suitable temperature environment maintained by the inner heat insulation sleeve (11), nitrogen oxides are reduced to N2 and H2O through the SCR catalyst coating to achieve deep purification of exhaust gas. S4 Pressure Stabilized Exhaust: The purified gas is guided by the second Archimedes spiral fan blade (18) to reduce the system back pressure before being discharged into the atmosphere.

9. The exhaust gas treatment method according to claim 8, characterized in that, In step S2, the heat generated by the primary catalytic filter element (9) is reduced by the inner heat insulation sleeve (11), and the airflow is disturbed by the alternating distribution of the spiral cylindrical air guide hole (13) and the prism vertical air guide hole (14), which promotes heat exchange and makes the overall temperature of the filter element uniform.

10. The exhaust gas treatment method according to claim 8, characterized in that, In step S4, the exhaust gas detection sensor (6) on the exhaust detection section (5) monitors the emission indicators in real time; when the exhaust gas fails to meet the standards, the system triggers an alarm and prompts for replacement or maintenance of the primary catalytic filter (9) and the secondary catalytic filter (10).

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