Passive regeneration type tail gas purifier with multiple layers of filter screens

Abstract

The utility model discloses a passive regeneration type tail gas purifier with multiple layers of filter screens, and relates to a tail gas purification device, and the tail gas purifier comprises a composite heat insulation shell, a three-stage gradient filter assembly, a piezoelectric actuating assembly and a dynamic catalysis supply unit. Wherein the composite heat insulation shell is of a cylindrical structure, an air inlet end and an air outlet end are arranged at the two ends of the composite heat insulation shell respectively, the composite heat insulation shell sequentially comprises a high-temperature-resistant lining layer, a heat insulation functional layer and a protective outer cover from inside to outside, the filter chamber lining cylinder is coaxially nested in the composite heat insulation shell, and an annular interlayer is formed between the filter chamber lining cylinder and the high-temperature-resistant lining layer. According to the tail gas purifier, through the integrated design of inter-layer flow field collaborative optimization, electric control vibration self-cleaning and dynamic catalytic supply, the technical problems that in the prior art, a plurality of layers of filter screens are poor in collaboration, low in passive regeneration efficiency and too high in back pressure are solved.

Description

Technical Field

[0001] This application relates to exhaust gas purification devices, and in particular to a passive regeneration exhaust gas purifier with multi-layer filters. Background Technology

[0002] As emission regulations become increasingly stringent in their requirements for the coordinated control of particulate matter and gaseous pollutants, vehicle exhaust purification technologies are gradually moving towards integration. In existing technologies, exhaust treatment devices with multi-layer filters typically employ a series structure of metal or ceramic filters, combined with an oxidation catalytic coating to achieve particulate capture and pollutant conversion. For example, a typical scheme uses a primary metal filter to intercept large particles, a secondary catalytic filter to treat fine particles and nitrogen oxides, and a final porous carrier to adsorb residual pollutants. While this structure can achieve staged filtration, it has many limitations in practical applications. Existing multi-layer filters suffer from poor flow channel matching between layers, leading to uneven airflow distribution. Especially at high speeds, eddies easily form in the transition areas between layers, causing a sudden increase in local pressure drop. Simultaneously, traditional passive regeneration relies on the oxidation reaction of a single catalytic layer, while multi-layer structures, due to differences in temperature field distribution, struggle to maintain consistent catalytic activity across layers. For instance, the primary filter, being close to the engine, experiences higher temperatures, but the catalytic coating is prone to sintering, while the final filter suffers from low regeneration efficiency due to insufficient temperature.

[0003] Existing passive regeneration mechanisms face insufficient synergy in multi-layer filtration structures. On the one hand, uneven carbon deposition among multiple filter layers makes it difficult to meet regeneration triggering conditions, resulting in spatial misalignment between high-temperature regions and catalytically active zones. On the other hand, traditional vibration cleaning mechanisms are difficult to adapt to different filter layer structures, and mechanical cleaning actions are easily attenuated by the damping of multiple filter layers. Furthermore, the stacking of multiple filter layers exacerbates back pressure imbalances. The pore structure of conventional homogeneous filter media cannot simultaneously accommodate the interception efficiency of particles of different sizes. Often, compensating for accuracy by increasing filter layer thickness leads to a linear increase in pressure loss. In terms of durability, the interface between multiple layers is prone to microcracks due to differences in thermal expansion. Particle penetration accelerates the peeling of the catalytic coating, and existing technologies lack a comprehensive thermal management solution for multi-layer filters, making it difficult to balance the operating temperature of each layer.

[0004] To address the aforementioned technical shortcomings, there is an urgent need to develop a novel multi-layer filter structure that achieves efficient passive regeneration through optimized interlayer synergistic mechanisms. Key challenges include ensuring flow field matching, balanced distribution of the regeneration temperature field, and structural reliability within the multi-layer filter. This requires overcoming the inherent trade-off between filtration accuracy and back pressure performance in traditional solutions, while simultaneously ensuring that each filter unit achieves self-sustaining cleaning and catalytic activity recovery without external energy input. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency in the existing technology and provide a passively regenerating exhaust gas purifier with multi-layer filters. This purifier solves the technical problems of poor synergy of multi-layer filters, low passive regeneration efficiency, and excessive back pressure in the existing technology through an integrated design of inter-layer flow field synergistic optimization, electronically controlled vibration self-cleaning, and dynamic catalytic replenishment. The device adopts an innovative solution combining all-mechanical and electromechanical components, achieving highly efficient synergy between particulate matter capture and pollutant conversion without the need for a complex control system.

[0006] To achieve the above objectives, this application discloses a passive regeneration exhaust gas purifier with multi-layer filters. The exhaust gas purifier includes a composite heat insulation shell, a three-stage gradient filter assembly, a piezoelectric actuation assembly, and a dynamic catalytic recharge unit.

[0007] The composite heat insulation shell is a cylindrical structure with an air inlet and an exhaust end at each end. The composite heat insulation shell consists of a high-temperature resistant inner lining, a heat insulation functional layer, and a protective outer cover from the inside to the outside. The composite heat insulation shell has a filter chamber liner nested coaxially inside, and an annular partition is formed between the filter chamber liner and the high-temperature resistant inner lining.

[0008] The three-stage gradient filter assembly is detachably inserted into and installed in the filter chamber liner through a support frame. The three-stage gradient filter assembly consists of a first-stage swirl separation module, a second-stage interception filter module, and a third-stage catalytic conversion module from the intake end to the exhaust end.

[0009] The first-stage cyclone separation module consists of a tapered spiral guide and a settling chamber. The inlet of the tapered spiral guide matches the air inlet of the composite heat insulation shell, and the outlet tapes to form a centrifugal separation chamber. The separation chamber is connected to the settling chamber. The centrifugal force field is used to achieve the pre-separation of large particles and metal debris, and the separated material is input into the settling chamber.

[0010] The secondary interception and filtration module is composed of multiple layers of staggered interception filter elements. The guide plates of adjacent filter elements are arranged at cross angles to form a composite cross-section flow channel, which forces the airflow to deflect continuously and enhances the particle collision and interception efficiency.

[0011] The three-stage catalytic conversion module is a gradient porous catalytic support with molecular sieve catalyst loaded on the inner wall of the pores, which realizes the interception of ultrafine particles and the catalytic reduction of gaseous pollutants.

[0012] The piezoelectric actuator is integrated into the composite heat insulation shell and consists of a piezoelectric ceramic actuator and a transmission link. The piezoelectric ceramic actuator drives the support frame of the three-stage filter assembly to generate axial micro-vibration synchronously through a high-frequency pulse signal to remove carbon deposits in each layer.

[0013] The dynamic catalytic replenishment unit includes a catalyst storage tank and a Venturi spray array. The catalyst storage tank is installed on the top of the composite heat-insulating shell and is connected to the Venturi spray array through a controllable valve. The Venturi spray array is embedded in the air inlet of the three-stage catalytic conversion module. It uses the local negative pressure generated by the high-speed airflow to uniformly spray the catalyst powder onto the surface of the catalyst carrier through the pipeline to form a dynamic active layer.

[0014] Furthermore, within the three-stage gradient filter assembly, conical guide rings are set between adjacent modules, and axial microgrooves are machined on the surface to reduce the intensity of interlayer turbulence.

[0015] This application, through the synergistic design of a three-stage gradient filtration assembly and a dual-vortex settling chamber, combined with piezoelectric actuation cleaning and dynamic catalytic replenishment mechanisms, effectively overcomes the problems of low passive regeneration efficiency, interlayer flow field imbalance, and insufficient structural reliability inherent in traditional multi-layer filtration devices. Compared with existing technologies, its beneficial effects include: significantly improving the synergistic effect of multi-layer filters in the graded capture of particulate matter; extending the passive regeneration cycle through self-sustaining vibration cleaning and dynamic catalytic layer renewal; optimizing the flow field distribution to reduce back pressure and suppress local clogging; and enhancing the system's durability and maintenance convenience under high-temperature vibration environments through modular design combined with a thermal expansion compensation mechanism, thus solving the pain point of traditional technologies where filtration accuracy, regeneration efficiency, and structural reliability are difficult to balance.

[0016] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0017] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0018] Figure 1 This is a schematic diagram of the internal structure of one embodiment disclosed in this application. Detailed Implementation

[0019] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0020] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0021] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0022] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0023] See attached document Figure 1 This embodiment discloses an exemplary structure of a passive regenerative exhaust gas purifier with multi-layer filters.

[0024] In this embodiment, it mainly consists of a composite heat insulation shell 1, a three-stage gradient filter assembly 2, a piezoelectric actuation assembly 3, and a dynamic catalytic recharge unit 4.

[0025] The composite heat insulation shell 1 is cylindrical, with an air inlet 101 and an exhaust 102 at both ends. From the inside to the outside, it includes a high-temperature resistant inner lining 103, a heat insulation functional layer 104, and a protective outer cover 105. A filter chamber liner 5 is coaxially nested inside the composite heat insulation shell 1. An annular partition 106 is formed between the filter chamber liner 5 and the high-temperature resistant inner lining 103, which plays a role in heat insulation and protection, effectively preventing the exhaust gas from being discharged at high temperature and increasing the working temperature of the composite heat insulation shell 1.

[0026] Those skilled in the art can select appropriate materials and processes to manufacture composite heat insulation shells according to actual needs. For example, the high-temperature resistant inner lining 103 can be made of ceramic fiber material, the heat insulation functional layer 104 can be made of vacuum heat insulation board or aerogel material, and the protective outer cover 105 can be made of high-strength alloy steel or stainless steel, etc. The selection of these materials and manufacturing processes are well known in the art and will not be described in detail here.

[0027] The three-stage gradient filter assembly 2 is detachably inserted into and installed within the filter chamber liner 5 via the support frame 6. From the inlet end 101 to the exhaust end 102, it consists of a first-stage cyclone separation module 201, a second-stage interception filter module 202, and a third-stage catalytic conversion module 203. The first-stage cyclone separation module 201 comprises a tapered spiral guide and a settling chamber. The inlet of the tapered spiral guide matches the inlet end 102 of the composite heat-insulating shell 1, and the outlet tapers to form a centrifugal separation chamber. This separation chamber connects to the settling chamber, utilizing a centrifugal force field to pre-separate large particles and metal debris. The separated material is then input into the settling chamber, effectively reducing the burden on subsequent filter modules and improving the overall lifespan and purification efficiency of the purifier. For example, in diesel vehicle exhaust emission treatment scenarios, this module can pre-separate larger carbon soot particles and metal debris generated by engine wear in the exhaust gas, reducing the risk of clogging of subsequent filters.

[0028] It should be noted that the specific design and manufacturing process of the tapered spiral guide can refer to existing swirl separation technology. For example, parameters such as the angle, width, and thickness of the guide vanes can be optimized and adjusted according to actual working conditions and fluid mechanics principles. These are well-known technologies in the field of science.

[0029] The secondary interception and filtration module 202 is composed of multiple layers of staggered interception filter elements 2022. The guide plates 2021 of adjacent filter elements are arranged at cross angles to form a composite cross-section flow channel, which forces the airflow to deflect continuously and enhances the particle collision interception efficiency.

[0030] The filter element can be made of sintered metal fiber materials or ceramic fiber filter media, which have high specific surface area and mechanical strength. It can operate stably in complex exhaust gas environments, effectively intercepting micron-sized particles, such as fine carbon soot particles in diesel vehicle exhaust, further purifying the exhaust gas and reducing particulate matter emissions. Specific manufacturing processes for the filter element, such as the sintering method for metal fibers and the molding process for ceramic fibers, are existing technologies in this field and will not be disclosed in detail here.

[0031] The three-stage catalytic conversion module 203 is a gradient porous catalytic support with molecular sieve catalyst loaded on the inner wall of the pores, achieving the interception of ultrafine particles and the catalytic reduction of gaseous pollutants. The catalytic support can be a honeycomb ceramic or metal support, possessing good thermal stability and mechanical strength. Its pore structure is designed with a gradient distribution to adapt to the interception and catalytic reaction requirements of pollutants of different particle sizes. The molecular sieve catalyst has highly efficient adsorption and catalytic performance, capable of specifically catalytically converting gaseous pollutants such as nitrogen oxides, carbon monoxide, and hydrocarbons into harmless nitrogen, carbon dioxide, and water vapor, significantly reducing the emission of harmful gases in exhaust gas and meeting stringent environmental emission standards. It should be noted that the molding process of the catalytic support and the loading method of the molecular sieve catalyst are existing technologies, and those skilled in the art can select and optimize them according to actual needs.

[0032] The piezoelectric actuator 3 is integrated into the composite heat-insulating housing 1 and consists of a piezoelectric ceramic actuator and a transmission link. The piezoelectric ceramic actuator receives high-frequency pulse signals and drives the support frame 5 of the three-stage filtration assembly 2 to synchronously generate axial micro-amplitude vibrations, thereby removing carbon deposits from each layer. The piezoelectric ceramic actuator features fast response, high precision, and high reliability. It can generate stable micro-amplitude vibrations at a specific frequency, which are transmitted to the support frame 5 via the transmission link, causing the entire filtration assembly to vibrate. This effectively loosens and removes carbon deposits adhering to the filter screen and catalyst carrier surface, achieving passive regeneration, reducing manual maintenance costs and equipment downtime, and improving the operational economy of the equipment.

[0033] For example, in an industrial waste gas treatment system that operates for extended periods, this piezoelectric actuator can automatically activate according to a set time period or a monitored differential pressure signal to vibrate and clean the filter components, ensuring a continuous and stable purification effect. The specific drive circuit and control method of the piezoelectric ceramic actuator are well-known technologies in the field and will not be elaborated upon here.

[0034] The dynamic catalytic replenishment unit 7 includes a catalyst storage tank and a Venturi jet array. The catalyst storage tank is installed on top of the composite insulated shell 1 and is controllably connected to the Venturi jet array via a controllable valve. The Venturi jet array is embedded at the air inlet of the three-stage catalytic conversion module 203, using the local negative pressure generated by the high-speed airflow to uniformly spray catalyst powder onto the surface of the catalyst support through pipelines, forming a dynamic active layer. The catalyst powder stored in the catalyst storage tank can be a composite material of noble metal catalysts (such as platinum, palladium, rhodium, etc.) and molecular sieve catalysts, which has high catalytic activity and stability.

[0035] In actual operation, when the vehicle's exhaust gas monitoring device (not part of this embodiment) detects a decrease in the catalytic efficiency of the catalyst carrier, the controllable valve can be opened through the external control system, so that the catalyst powder is evenly sprayed onto the surface of the catalyst carrier under the action of the Venturi spray array, replenishing the active components in time, restoring the performance of the catalyst carrier, extending its service life, and ensuring the continuous and stable exhaust gas purification effect. It is especially suitable for treating industrial exhaust gas emissions with high concentrations and complex components, and can effectively cope with changes in catalytic demand under different operating conditions.

[0036] It should be noted that the structural design of the catalyst storage tank and the specific injection parameter adjustment of the Venturi injection array can refer to existing similar technologies, and will not be described in detail here.

[0037] Furthermore, to further optimize the airflow transition between filter components and reduce interlayer turbulence intensity, a conical guide ring with axial microgrooves is installed between adjacent modules within the three-stage gradient filter component 2. The shape of the conical guide ring guides the airflow smoothly from one module to the next, reducing airflow impact and turbulence, and improving the flow uniformity and purification efficiency of the entire filtration system. The axial microgrooves help reduce interlayer turbulence intensity, further reducing airflow wear and energy loss on the filter components, while also increasing the contact area and time between the airflow and the filter media, thus enhancing the purification effect. The manufacturing process and material selection of the conical guide ring can be determined according to actual needs, and these are all technologies known to those skilled in the art.

[0038] In practical applications, such as in the engine exhaust emission treatment system of an automobile manufacturer, this passive regenerative exhaust purifier with multi-layered filters is installed between the engine exhaust pipe and the atmospheric emission port. When the engine starts and runs, the generated high-temperature exhaust gas first enters the filter chamber inside the composite heat-insulating housing through the intake end. After undergoing multi-stage treatment, the gaseous pollutants in the exhaust gas undergo catalytic reduction reactions, transforming into harmless substances before being discharged into the atmosphere through the exhaust end.

[0039] Compared with traditional exhaust gas purifiers, the purifier in this embodiment, through the gradient design of multi-layer filters, combined with the passive regeneration function of piezoelectric actuators and the timely active replenishment of dynamic catalytic replenishment units, can not only effectively intercept particulate matter of different sizes, but also efficiently treat gaseous pollutants, and greatly reduce the amount of manual maintenance and equipment downtime, thereby improving the operating efficiency and economy of the entire exhaust gas purification system.

[0040] In summary, this passive regenerative exhaust gas purifier with multi-layer filters achieves efficient, stable, and economical exhaust gas purification through reasonable structural design and close cooperation of its components, providing reliable technical support for addressing increasingly stringent environmental emission standards.

[0041] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A passive regenerative type exhaust gas purifier with a multi-layer filter, characterized by, The tail gas purifier comprises a composite heat insulation shell, a three-stage gradient filtering assembly, a piezoelectric actuating assembly and a dynamic catalytic supplement unit. The composite heat insulation shell is in a cylindrical structure, and is provided with an air inlet end and an air outlet end at two ends respectively. The composite heat insulation shell comprises, from inside to outside, a high-temperature-resistant inner lining layer, a heat insulation functional layer and a protective outer cover. A filtering chamber lining tube is coaxially nested in the composite heat insulation shell, and an annular partition layer is formed between the filtering chamber lining tube and the high-temperature-resistant inner lining layer. The three-stage gradient filtering assembly is detachably inserted and installed in the filtering chamber lining tube through a support frame. The three-stage gradient filtering assembly comprises, from the air inlet end to the air outlet end, a first-stage cyclone separation module, a second-stage interception filtering module and a third-stage catalytic conversion module.

2. A passive regenerative type exhaust gas purifier with multiple filter screens as claimed in claim 1, wherein, The first-stage cyclone separation module is composed of a tapered spiral flow guide and a sedimentation chamber. The inlet of the tapered spiral flow guide is matched with the air inlet end of the composite heat insulation shell, and the outlet is tapered to form a centrifugal separation chamber. The separation chamber is connected with the sedimentation chamber, and the pre-separation of large particles and metal scraps is realized through a centrifugal force field. The separated materials are input into the sedimentation chamber. The second-stage interception filtering module is composed of a plurality of layers of staggered interception filter cartridges. The flow guide plates of adjacent filter cartridges are arranged at a cross angle to form a composite cross-section flow channel, so as to force the airflow to produce continuous directional deflection and enhance the particle collision interception efficiency. The third-stage catalytic conversion module is a gradient porous catalytic carrier, and a molecular sieve catalyst is loaded on the inner wall of the hole. The interception of superfine particles and the catalytic reduction of gaseous pollutants are realized. The piezoelectric actuating assembly is integrated in the composite heat insulation shell and is composed of a piezoelectric ceramic actuator and a transmission connecting rod. The piezoelectric ceramic actuator drives the support frame of the three-stage filtering assembly to produce synchronous axial micro-vibration through high-frequency pulse signals, so as to remove the accumulated carbon in each layer. The dynamic catalytic supplement unit comprises a catalyst storage tank and a Venturi injection array. The catalyst storage tank is installed at the top of the composite heat insulation shell and is in controllable communication with the Venturi injection array through a controllable valve. The Venturi injection array is embedded at the air inlet of the third-stage catalytic conversion module. The catalyst powder is uniformly sprayed to the surface of the catalytic carrier through a pipeline by using the local negative pressure generated by high-speed airflow to form a dynamic active layer.

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