Improved diesel engine tail gas particle catcher and tail gas aftertreatment system

Abstract

The invention discloses an improved diesel engine tail gas particle catcher and a tail gas after-treatment system, and belongs to the technical field of diesel engine tail gas after-treatment. The diesel engine tail gas particle catcher is firstly protected and improved, the diesel engine tail gas particle catcher comprises a particle catcher shell, a tail gas inlet pipe and a filter cartridge, and a check valve is arranged in the tail gas inlet pipe; an ash hopper is installed at the tail gas inlet end of the particle catcher shell, a connecting plate is installed on the inner side of the tail gas outlet end of the particle catcher shell, the filter cartridge is installed on the connecting plate, and a filtering part of the filter cartridge faces the interior of the particle catcher shell. And a vibration device is arranged on the outer side of the particle catcher shell. The invention further protects a tail gas aftertreatment system, and the oxidation catalyst is arranged at the rear end of the tail gas outlet end of the particle catcher. The method has the beneficial effects that particulate matters in the tail gas of the diesel engine are removed at low resistance and high efficiency, the regeneration operation is simple and efficient, and the energy consumption is low; and meanwhile, the service life of the oxidation catalyst is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine exhaust after-treatment, and particularly relates to an improved diesel engine exhaust particulate trap and an exhaust after-treatment system. Background Art

[0002] While diesel engines, as the main power source for automobiles and non-road mobile machinery, provide convenience to society, they have gradually become one of the main causes of air pollution. According to the relevant requirements of the fourth stage in the "Emission Limits and Measurement Methods for Exhaust Pollutants from Diesel Engines for Non-road Mobile Machinery (China's Third and Fourth Stages)" (GB 20891-2014) and its "Amendment Sheet", it is required that the exhaust pollutants of diesel engines include particulate matter and gaseous pollutants. Particulate matter has a direct impact on human health and ambient air quality, and its particle size is related to the degree of its impact on the incidence of respiratory and cardiovascular diseases. At the same time, gaseous pollutants, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NO x x), will undergo photochemical reactions in the air to generate secondary organic aerosols, reducing atmospheric visibility and deteriorating air quality.

[0003] In order to reduce the emissions of particulate matter and gaseous pollutants in diesel engine exhaust, at present, the vast majority of domestic diesel engine manufacturers adopt the diesel engine exhaust after-treatment technical route represented by the products of Bosch of Germany to meet the national standards for pollutant limits. That is, a technical route combining an oxidation catalytic converter (DOC), a particulate trap (DPF), and a reduction catalytic converter (SCR) is adopted. In this technical route, the oxidation catalytic converter is located in front of the particulate trap. The oxidation catalytic converter removes carbon monoxide and hydrocarbons through oxidation, and at the same time uses the heat generated during oxidation to heat and warm the exhaust gas. The subsequent particulate trap is regenerated by burning off particulate matter, and the heat also promotes the removal of NO x x.

[0004] At present, although the exhaust gas of diesel engines can meet the emission standards completely after being treated by this technical route, some serious technical defects have also occurred. The manifestation of the serious technical defects is a substantial increase in exhaust back pressure, which causes a substantial increase in diesel engine fuel consumption, a significant decrease in output power, and even a complete shutdown of the diesel engine. Among them, the wall-flow porous honeycomb ceramic particulate trap (DPF) made of silicon carbide or cordierite materials, represented by the products of Bosch of Germany, is the main cause of such serious technical defects. By analyzing its structure and working principle (see the attached Figure 1 and attached Figure 2) Analysis, tracing the reasons for its serious technical defects: Its structure filters particulate matter by alternately blocking both ends of the honeycomb ceramic pores (front block and rear block) and using the pore walls of the ceramic. The so-called wall-flow means that the gas penetrates and filters through the side walls, obtaining a large filtration area within a relatively small volume to achieve the function of filtering particulate matter. However, this structure has the following technical problems: (1) This filtration form belongs to the internal filtration form where the dusty gas enters from the pre-filter channel inside the filter, passes through the filter layer, and then discharges clean gas from the post-filter channel of the filter. This form causes the filtered particulate matter to be stored in the pre-filter channel space surrounded by the filter layer, which is extremely difficult to remove; (2) Since the distance between the filter layers is too short (about 1.5 mm, even smaller at the corners), and it is a four-sided filter layer, the filtered particulate matter cannot break away from the filter layer, making the pre-filter channel become a particulate matter warehouse (or ash bin). The accumulation of ash causes the filter layer to become blocked, resulting in a large pressure difference between the inside and outside of the filter layer. This large pressure difference significantly increases the exhaust back pressure of the diesel engine, causing a sharp increase in diesel fuel consumption and a sharp decrease in output power, and even completely stalling the diesel engine. When the filtered particulate matter reaches about 50% of this space, the filter layer loses its filtering function. For example, in heavy trucks, the failure time of this particulate trap is about 30 hours. In the use of construction machinery, because many construction machinery are operating at idle speed, the particulate matter generated far exceeds that of heavy trucks operating under normal conditions. Therefore, the failure time of this particulate trap in construction machinery is generally only a dozen hours, or even a few hours. According to the setting of the diesel engine manufacturer, when the pressure difference between the inside and outside of the filter layer (dust-containing area and clean area) reaches the threshold value of 20 kPa, regeneration treatment is required. In the working range from the initial state to the threshold value, the average value of the pressure difference between the inside and outside of the filter layer of the particulate trap will reach more than 10 kPa, increasing the fuel consumption of the diesel engine by 2.3 - 6.7%, greatly increasing the environmental cost of the diesel engine operation. When the pressure difference between the inside and outside of the filter layer (dust-containing area and clean area) reaches the threshold value of 20 kPa, the wall-flow porous honeycomb ceramic particulate trap (DPF) starts the operation of particulate trap regeneration. The purpose of the operation is to remove the filtered particulate matter in the pre-filter channel and solve the problem of filter failure caused by the blockage of the pre-filter channel. Due to structural defects, regeneration means that are very effective in the field of air filtration technology, such as mechanical vibration and pulse back-blowing for dust cleaning, have no effect on the wall-flow porous honeycomb ceramic particulate trap. Only by injecting diesel (the diesel engine manufacturer sets a control program in the diesel engine control system to spray the unburned diesel into the blocked pre-filter channel, then run the diesel engine at high speed, and use the heat generated by the oxidation of the front-end oxidation catalyst (DOC) to heat the exhaust gas to above 600°C, and ignite and ablate the particulate matter blocking the pre-filter channel through high temperature to achieve the regeneration of the filtering function of the particulate trap.Structurally, the pre-filter channels are multiple narrow channels with a size of 1.5×1.5 mm and a length of about 200 mm. When spraying diesel into the narrow channels, the amount of diesel sprayed each time is limited. Therefore, the distance of regeneration by ablation each time is very short, and the regeneration process must be completed through multiple spraying and burning cycles. According to the usage specifications of diesel engine manufacturers, it is required to run the diesel engine at high speed in neutral for 45 minutes to one hour for parking. This regeneration method not only wastes precious fuel by running the diesel engine in neutral at high speed for a long time during parking and spraying fuel into the particulate matter accumulation area, but also makes the regeneration process complicated and time-consuming due to long-term parking. Therefore, this regeneration method is energy-consuming and inefficient. There is also a serious problem that because the oil contains a small amount of substances with very high ignition points and high viscosities, they cannot be burned off in a short time of burning and will penetrate into the gaps of the filter layer, damaging the filter layer. Therefore, the regeneration effect will be discounted each time it is burned. According to relevant information, the number of regeneration times of the wall-flow porous honeycomb ceramic particulate trap is about 15 times. After 15 times, the regeneration effect will be discounted to the extent that the particulate trap can no longer be used.

[0005] Since its regeneration relies on the heat generated by the oxidation catalysis of the oxidation catalyst (DOC) at its front end, the oxidation catalyst (DOC) can only be placed in the front stage of the diesel engine exhaust particulate trap. In this way, the precious metal coating of the oxidation catalyst (DOC) has to work in the dusty gas, resulting in the precious metal coating being washed away by the dusty gas and losing its oxidation catalytic function. In addition, the unburned diesel first passes through the oxidation catalyst (DOC) before reaching the diesel engine exhaust particulate trap, which covers the precious metal coating of the oxidation catalyst (DOC) and reduces the oxidation catalytic effect. At the same time, the pollution of the precious metal coating by the unburned diesel will also cause the oxidation catalyst to be poisoned, reducing the service life of the oxidation catalyst (DOC). Summary of the Invention

[0006] In view of the deficiencies of the prior art, the first object of the present invention is to provide an improved diesel engine exhaust particulate trap, which can solve the technical problems of easy blockage of the filter layer during filtration of the particulate trap in the prior art, high energy consumption, low efficiency in regeneration, and short service life of the diesel engine exhaust particulate trap.

[0007] The second object of the present invention is to provide an exhaust gas post-treatment system, which can solve the problems of insufficient removal of fine exhaust gas particles, short durability of the oxidation catalyst, and low use efficiency.

[0008] To achieve the above objects, the present invention first discloses an improved diesel engine exhaust particulate trap, including a particulate trap housing, an exhaust gas inlet pipe, and a filter cartridge. A check valve is arranged inside the exhaust gas inlet pipe;

[0009] A dust hopper is installed at the exhaust gas inlet end of the particulate filter housing for storing the filtered dust, and the particulate filter housing is detachably connected to the dust hopper;

[0010] A connecting plate is installed inside the exhaust gas outlet end of the particulate filter housing. The connecting plate is provided with ventilation holes. The filter cartridge is installed on the connecting plate. The open end of the filter cartridge corresponds to the ventilation holes of the connecting plate, and the filtering part of the filter cartridge faces the inside of the particulate filter housing;

[0011] A vibration device is arranged on the outside of the particulate filter housing.

[0012] Further, the vibration device is a high-frequency vibration motor with an eccentric wheel.

[0013] Further, the vibration device is an electromagnetic vibrator.

[0014] Further, the filter cartridge is a cylindrical barrel made by winding and sintering multiple layers of stainless steel filter meshes.

[0015] Further, the filter cartridge is a frustum-shaped barrel made by winding and sintering multiple layers of stainless steel filter meshes.

[0016] Further, a filter cartridge end sleeve is installed at the open end of the filter cartridge. The side of the filter cartridge end sleeve is provided with a sleeve with external threads, and the ventilation holes of the connecting plate are provided with internal threads that match the external threads of the filter cartridge end sleeve. The connecting plate and the filter cartridge end sleeve are fixedly connected by threads.

[0017] Further, a sealing gasket is arranged between the filter cartridge end sleeve and the bottom surface of the connecting plate.

[0018] Further, a filter cartridge bottom support is also arranged at the closed side end of the filter cartridge. The filter cartridge bottom support is circular ring-shaped and is fixedly connected to the closed side end of the filter cartridge. A tool connection end is arranged on the filter cartridge bottom support, and the tool connection end is used for externally rotating the filter cartridge for installation.

[0019] Further, the tool connection end on the filter cartridge bottom support is a square hole, and a square column is inserted into the square hole.

[0020] Further, a differential pressure monitor is also included. The differential pressure monitor includes a front air nozzle, a front air pipe, a differential pressure transmitter, a rear air pipe, and a rear air nozzle. The front air nozzle is arranged on the side wall of the exhaust gas inlet end of the particulate filter housing and is communicated with the inside of the particulate filter housing. One end of the front air pipe is connected to the front air nozzle, and the other end of the front air pipe is connected to the differential pressure transmitter. The rear air nozzle is arranged on the side wall of the exhaust gas outlet end of the particulate filter housing and is communicated with the inside of the housing. One end of the rear air pipe is connected to the rear air nozzle, and the other end of the rear air pipe is connected to the differential pressure transmitter.

[0021] Further, a controller is also included. The controller is electrically connected to the vibration device, and a differential pressure threshold alarm light, a vibration intensity regulator, and a vibration start button are arranged on the controller.

[0022] Furthermore, a photoelectric switch and an ash bin full alarm lamp are arranged on the upper part of the side wall of the ash hopper, and the photoelectric switch and the ash bin full alarm lamp are electrically connected.

[0023] Furthermore, the tail gas inlet pipe is arranged at the end of the tail gas inlet end of the particulate trap housing, and a first clamp is provided to connect the tail gas inlet pipe with the particulate trap housing; the side wall of the tail gas inlet end of the particulate trap housing is connected with the ash hopper through a second clamp.

[0024] Furthermore, the tail gas inlet pipe is arranged on the side wall of the tail gas inlet end of the particulate trap housing; the end of the tail gas inlet end of the particulate trap housing is connected with the ash hopper through a second clamp.

[0025] According to the second aspect of the present invention, there is also provided an exhaust gas after-treatment system, including the improved diesel engine exhaust particulate trap as described above. An oxidation catalytic converter housing is connected to the exhaust gas outlet end of the particulate trap housing, and an oxidation catalytic converter is arranged in the internal space of the oxidation catalytic converter housing.

[0026] Furthermore, a flange is arranged at the exhaust gas outlet end of the particulate trap housing, and a flange is arranged at the end of the oxidation catalytic converter housing. A third clamp is provided to connect the particulate trap housing and the oxidation treatment housing through the third clamp.

[0027] The present invention has the following beneficial effects:

[0028] 1. Compared with the wall-flow porous honeycomb ceramic particulate trap, in the improved diesel engine exhaust particulate trap of the present invention, due to the external filtration method, the filtered particulate matter accumulates outside the filter layer, the distance between the filter layers is relatively large, there is enough ash storage space, the vibration device shakes off the particulate matter outside the filter cartridge, and at the same time, during the driving of the diesel vehicle, the bumps will cause some of the filtered particulate matter to automatically separate from the filter layer, forming natural regeneration. Therefore, the increase in the pressure difference between the two sides of the filter layer with the extension of the filtration working time is significantly reduced. The number of regenerations can be greatly reduced during the same working duration, and the service life of the diesel engine exhaust particulate trap is long;

[0029] 2. Due to the adoption of the regeneration method of high-frequency mechanical vibration, the ash accumulated outside the filter cartridge can quickly separate from the outside of the filter cartridge under the action of the high-frequency mechanical vibration force. The regeneration effect is good, the regeneration energy consumption is extremely low, and at the same time, the regeneration can be started while the diesel engine is working, so that the number of regenerations can be appropriately increased, and the diesel engine can always work under the condition of low back pressure, realizing the operation of the diesel engine with low fuel consumption and high power;

[0030] 3. In the exhaust gas after-treatment system, the oxidation catalytic converter is placed at the rear stage of the particulate trap, so that the diesel engine exhaust gas removes particulate matter and then passes through the oxidation catalytic converter, which can avoid the precious metal coating of the oxidation catalytic converter being washed by the dust-containing gas and covered and poisoned by the oil product, and improve the service life of the oxidation catalytic converter;

[0031] 4. In the exhaust gas after-treatment system, the remaining particulate matter after filtration is particulate matter with a very small average particle size and a very large specific surface area. Placing the oxidation catalyst after filtration enables the oxidation catalyst to better play its role in oxidizing and ablating some of the particulate matter, which can further improve the purification efficiency of the diesel engine exhaust gas after-treatment system for particulate matter. During regeneration, unburned diesel is not required, which extends the service life of the oxidation catalyst and saves diesel. Description of the Drawings

[0032] Figure 1 Diesel engine exhaust gas after-treatment system diagram of the prior art;

[0033] Figure 2 Schematic diagram of the filtration treatment principle of the prior art;

[0034] Figure 3 Cross-sectional view of the improved diesel engine exhaust gas particulate trap of Example 1;

[0035] Figure 4 For Figure 3 Partial enlarged view at B in

[0036] Figure 5 For Figure 3 Partial enlarged view at C in

[0037] Figure 6 Stereogram of the filter component on the closed side of the filter cartridge;

[0038] Figure 7 Stereogram of the filter component on the open side of the filter cartridge;

[0039] Figure 8 Stereogram of the filter cartridge connection component on the closed side of the filter cartridge;

[0040] Figure 9 Front view of the filter cartridge connection component;

[0041] Figure 10 Stereogram of the filter cartridge end sleeve;

[0042] Figure 11 Stereogram of the filter cartridge bottom support;

[0043] Figure 12 Stereogram of the main body component of the filter cartridge bottom support;

[0044] Figure 13 Stereogram of the connecting plate;

[0045] Figure 14 Front view of the controller;

[0046] Figure 15 Schematic diagram of the filtration principle of the filter cartridge;

[0047] Figure 16 It is a cross-sectional view of the improved diesel engine exhaust particulate trap of Example 2;

[0048] Figure 17 It is a cross-sectional view of the improved diesel engine exhaust particulate trap of Example 3;

[0049] Figure 18 It is a front view of the filter cartridge connection component of Example 3;

[0050] Figure 19 It is a cross-sectional view of the diesel engine exhaust aftertreatment system of Example 4;

[0051] Figure 20 It is a cross-sectional view of the diesel engine exhaust aftertreatment system of Example 5.

[0052] In the figure, 1 is the particulate trap housing; 2 is the exhaust gas inlet pipe; 3 is the check valve; 4 is the filter cartridge; 5 is the connecting plate; 5-1 is the vent hole; 6 is the ash hopper; 7 is the vibration device; 8 is the differential pressure monitor; 8-1 is the front air nozzle; 8-2 is the front air pipe; 8-3 is the differential pressure transmitter; 8-4 is the rear air pipe; 8-5 is the rear air nozzle; 9 is the controller; 9-1 is the differential pressure threshold alarm light; 9-2 is the vibration intensity regulator; 9-3 is the vibration start button; 10 is the first clamp; 11 is the second clamp; 12 is the photoelectric switch; 13 is the ash bin full alarm light; 14 is the filter cartridge bottom support; 14-1 is the square hole; 14-2 is the square column; 15 is the filter cartridge end sleeve; 16 is the gasket; 17 is the oxidation catalyst housing; 18 is the oxidation catalyst; 19 is the third clamp. Specific embodiments

[0053] The following combines the attached Figures 3 to 20 The specific embodiments of the present invention will be described in detail. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention, and are not used to limit the protection scope of the present invention.

[0054] Example 1:

[0055] This example provides an improved diesel engine exhaust particulate trap, as Figures 3 to 15 shown, including a particulate trap housing 1, an exhaust gas inlet pipe 2 and a filter cartridge 4. A check valve 3 is arranged inside the exhaust gas inlet pipe 2; the filter cartridge 4 is a cylindrical barrel made by winding and sintering multiple layers of stainless steel filter meshes, with good filtering effect, and at the same time, the filter mesh structure helps with ash cleaning and regeneration. The function of the check valve 3 is to prevent the exhaust gas containing particulate matter from flowing back into the diesel engine through the diesel engine exhaust port during the pulse injection and backblowing of compressed air.

[0056] A dust hopper 6 is installed at the exhaust gas inlet end of the particulate filter housing 1 for storing the filtered dust, and the particulate filter housing 1 and the dust hopper 6 are detachably connected. In this embodiment, the side wall of the exhaust gas inlet end of the particulate filter housing 1 and the dust hopper 11 are connected by a second clamp 11.

[0057] A connecting plate 5 is installed inside the exhaust gas outlet end of the particulate filter housing 1. A ventilation hole 5-1 is provided on the connecting plate 5. The filter cartridge 4 is installed on the connecting plate 5. The open end of the filter cartridge 4 corresponds to the ventilation hole 5-1 of the connecting plate 5, and the filtering part of the filter cartridge 4 faces the inside of the particulate filter housing 1.

[0058] A vibration device 7 is arranged on the outside of the particulate filter housing 1. Specifically, the vibration device 7 is arranged on the outside of the particulate filter housing 1 corresponding to the connecting plate 5, and the vibration action of the vibration device 7 is transmitted to the filter cartridge 4. The vibration device 7 is a high-frequency vibration motor with an eccentric wheel or an electromagnetic vibrator, and other devices capable of generating vibration action are also within the scope of the present invention.

[0059] As Figures 6 to 9 , a filter cartridge end sleeve 15 is installed at the open end of the filter cartridge 4. The side of the filter cartridge end sleeve 15 is provided with a sleeve with an external thread. The ventilation hole 5-1 of the connecting plate 5 is provided with an internal thread that matches the external thread of the filter cartridge end sleeve 15. The connecting plate 5 and the filter cartridge end sleeve 15 are fixedly connected by threads. The outer edge of the connecting plate 5 is fixedly connected to the inner wall of the particulate filter housing 1. A sealing gasket 16 is arranged between the filter cartridge end sleeve 15 and the bottom surface of the connecting plate 5.

[0060] As Figure 15 shown, when the dusty exhaust gas passes through the filter cartridge 4, the dust particles are blocked on the outer surface of the filter cartridge 4, and the internal space of the filter cartridge 4 is the exhaust gas after dust removal, avoiding the problem that the dust particles in the prior art accumulate inside the filter cartridge 4.

[0061] A filter cartridge bottom support 14 is further arranged at the closed side end of the filter cartridge 4. The filter cartridge bottom support 14 is circular ring-shaped and is fixedly connected to the closed side end of the filter cartridge 4. A tool connection end is arranged on the filter cartridge bottom support 14, and the tool connection end is used for externally rotating the filter cartridge 4 for installation. The tool connection end on the filter cartridge bottom support 14 is a square hole 14-1, and a square column 14-2 is inserted into the square hole 14-1.

[0062] It further includes a differential pressure monitor 8. The differential pressure monitor 8 includes a front air nozzle 8-1, a front air pipe 8-2, a differential pressure transmitter 8-3, a rear air pipe 8-4 and a rear air nozzle 8-5. As Figure 5As shown in the figure. The front air nozzle 8-1 is arranged on the side wall of the tail gas inlet end of the particulate trap housing 1. The front air nozzle 8-1 is communicated with the inside of the particulate trap housing 1. One end of the front air pipe 8-2 is connected to the front air nozzle 8-1, and the other end of the front air pipe 8-2 is connected to the differential pressure transmitter 8-3. The rear air nozzle 8-5 is arranged on the side wall of the tail gas outlet end of the particulate trap housing 1. The rear air nozzle 8-5 is communicated with the inside of the housing. One end of the rear air pipe 8-4 is connected to the rear air nozzle 8-5, and the other end of the rear air pipe 8-4 is connected to the differential pressure transmitter 8-3. The differential pressure monitor 8 is used to measure the pressure difference between the inside and outside of the filter layer (dust-containing area and clean area).

[0063] It further includes a controller 9. The controller 9 is electrically connected to the vibration device 7. A differential pressure threshold alarm lamp 9-1, a vibration intensity regulator 9-2 and a vibration start button 9-3 are arranged on the controller 9.

[0064] An optoelectronic switch 12 and a ash bin full alarm lamp 13 are arranged on the upper part of the side wall of the ash hopper 6. The optoelectronic switch 12 and the ash bin full alarm lamp 13 are electrically connected, as Figure 4 shown. The optoelectronic switch 12 is a sensing device for sensing the limit of the ash accumulation amount in the ash hopper 6 through optoelectronic sensing. When the ash accumulation amount reaches the set height, the optoelectronic switch 12 emits a signal, and the ash bin full alarm lamp 13 emits light for alarm, indicating that the ash hopper 6 is full and needs to be unloaded, emptied, and then reinstalled. The ash hopper 6 provides a storage space for the filtered particulate matter, completely avoiding the interference to the filtration process caused by the lack of storage space for the filtered particulate matter in the wall-flow porous honeycomb ceramic particulate trap.

[0065] The tail gas inlet pipe 2 is arranged at the end of the tail gas inlet end of the particulate trap housing 1, and a first clamp 10 is provided to connect the tail gas inlet pipe 2 and the particulate trap housing 1; the side wall of the tail gas inlet end of the particulate trap housing 1 is connected to the ash hopper 6 through a second clamp 11.

[0066] Embodiment 2:

[0067] The difference between this embodiment and Embodiment 1 is that the particulate trap housing 1 is arranged in the vertical direction. The tail gas inlet pipe 2 is arranged on the side wall of the tail gas inlet end of the particulate trap housing 1, and the tail gas inlet pipe 2 is communicated with the inside of the particulate trap housing 1; the end of the tail gas inlet end of the particulate trap housing 1 is connected to the ash hopper 6 through a second clamp 11, and the ash hopper 6 is communicated with the inside of the particulate trap housing 1. The other parts are the same as those in Embodiment 1, as Figure 16 shown.

[0068] Embodiment 3:

[0069] The difference between this embodiment and Embodiment 2 is that the filter cartridge 4 is a frustum-shaped cylinder made by winding and sintering multiple layers of stainless steel filter meshes, as Figure 17。The large bottom surface of the filter cartridge 4 is the open end, and the large bottom surface of the filter cartridge 4 is fixedly welded to the filter cartridge end sleeve 15; the small bottom surface of the filter cartridge 4 is the closed end, and the small bottom surface of the filter cartridge 4 is fixedly welded to the filter cartridge bottom support 14. The connection structure of the filter cartridge 4 is as Figure 18 shown. The other parts are the same as those in Embodiment 1. The filter cartridge 4 adopts a frustum shape. Compared with a cylindrical filter cartridge, the distance between multiple filter cartridges 4 is increased in this embodiment. The filtered particulate matter accumulates outside the filter layer. The distance between the filter layers is large, providing sufficient ash storage space. At the same time, the side surface of the filter cartridge 4 is inclined, facilitating ash falling and being more conducive to vibration regeneration.

[0070] The beneficial effects of Embodiment 1, Embodiment 2, and Embodiment 3 are as follows: (1). Compared with the wall-flow porous honeycomb ceramic particulate trap, in the improved diesel engine exhaust particulate trap of the present invention, due to the external filtration method, the filtered particulate matter accumulates outside the filter layer. The distance between the filter layers is large, providing sufficient ash storage space. At the same time, during the bumpy driving of the diesel vehicle, some of the filtered particulate matter will automatically detach from the filter layer, forming natural regeneration. Therefore, the increase in the pressure difference on both sides of the filter layer with the extension of the filtration working time is significantly reduced. The number of regenerations can be greatly reduced during the same working duration, and the service life of the diesel engine exhaust particulate trap is long; (2). Due to the use of the high-frequency mechanical vibration regeneration method, the ash accumulated on the outside of the filter cartridge can quickly detach from the outside of the filter cartridge under the action of the high-frequency mechanical vibration force. The regeneration effect is good, the regeneration energy consumption is extremely low, and regeneration can be started while the diesel engine is working. In this way, the number of regenerations can be appropriately increased, enabling the diesel engine to always work under low backpressure conditions, achieving low fuel consumption and high power operation of the diesel engine.

[0071] Embodiment 4:

[0072] Embodiment 4 of the present invention is an exhaust gas aftertreatment system including the improved diesel engine exhaust particulate trap provided in Embodiment 1. Embodiment 4 is a horizontal diesel engine exhaust gas aftertreatment system, as Figure 19 shown.

[0073] An oxidation catalytic converter housing 17 is connected to the exhaust gas outlet end of the particulate trap housing 1, and an oxidation catalytic converter 18 is arranged in the internal space of the oxidation catalytic converter housing 17.

[0074] Specifically, a flange is provided at the exhaust gas outlet end of the particulate trap housing 1, and a flange is provided at the end of the oxidation catalytic converter housing 17. A third clamp 19 is provided to connect the particulate trap housing 1 and the oxidation treatment housing through the third clamp 19.

[0075] Seven filter cartridges 4 are arranged on the connecting plate 5. The diameter of the filter cartridge 4 is 50 mm, the length is 200 mm, the thickness of the filter layer of the filter cartridge 4 is 1.7 mm, and the pore density of the single-layer filter screen is 100 meshes.

[0076] Embodiment 5:

[0077] An embodiment of the present invention is another exhaust gas aftertreatment system that includes an improved diesel engine exhaust particulate filter provided in Embodiment 3. Embodiment 5 is a vertical diesel engine exhaust gas aftertreatment system, as Figure 20 shown. An exhaust gas outlet end of a particulate filter housing 1 is connected to an oxidation catalyst housing 17. An oxidation catalyst 18 is disposed in an internal space of the oxidation catalyst housing 17. A third clamp 19 is provided to connect the particulate filter housing 1 and the oxidation treatment housing through the third clamp 19.

[0078] Seven filter cartridges are provided on a connecting plate 5. The filter cartridge 4 has a diameter of 50 mm, a length of 200 mm, a filtration layer thickness of 1.7 mm, and a pore density of 100 meshes for a single-layer filter screen.

[0079] The diesel engine exhaust gas aftertreatment devices of Embodiment 4 and Embodiment 5 of the present invention include all the technical solutions of the improved diesel engine exhaust particulate filters in Embodiment 1, Embodiment 2, and Embodiment 3, and thus have the beneficial effects described in Embodiment 1 to Embodiment 3, which will not be elaborated here. In addition, Embodiment 4 and Embodiment 5 of the present invention have the following beneficial effects: (1) In the exhaust gas aftertreatment system, the oxidation catalyst is placed at the rear stage of the particulate filter, so that the diesel engine exhaust gas passes through the oxidation catalyst after removing particulate matter, which can avoid the noble metal coating of the oxidation catalyst being washed by the dust-containing gas and poisoned by oil product coverage pollution, and improve the service life of the oxidation catalyst; (2) In the exhaust gas aftertreatment system, the remaining particulate matter after filtration is particulate matter with a very small average particle size and a very large specific surface area. Placing the oxidation catalyst after filtration enables the oxidation catalyst to better play its role of oxidizing and burning off some particulate matter, and can further improve the purification efficiency of the diesel engine exhaust gas aftertreatment system for particulate matter. During regeneration, unburned diesel is not required, which prolongs the service life of the oxidation catalyst and saves diesel.

[0080] The above are only schematic specific embodiments of the present invention. Without departing from the concept and principles of the present invention, any equivalent changes and modifications made by any person skilled in the art shall fall within the scope of protection of the present invention.

Claims

1. An improved diesel engine exhaust particulate trap, comprising a particulate trap housing (1), an exhaust gas inlet pipe (2) and a filter cartridge (4), characterized in that: A check valve (3) is provided inside the exhaust gas inlet pipe (2); A dust hopper (6) is installed at the exhaust gas inlet end of the particulate filter housing (1) for storing the filtered dust, and the particulate filter housing (1) is detachably connected to the dust hopper (6); A connecting plate (5) is installed inside the exhaust gas outlet end of the particulate filter housing (1). Vent holes (5-1) are provided on the connecting plate (5). The filter cartridge (4) is installed on the connecting plate (5). The open end of the filter cartridge (4) corresponds to the vent holes (5-1) of the connecting plate (5), and the filtering part of the filter cartridge (4) faces the inside of the particulate filter housing (1); A vibration device (7) is provided on the outside of the particulate filter housing (1).

2. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, The vibration device (7) is a high-frequency vibration motor with an eccentric wheel.

3. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, The vibration device (7) is an electromagnetic vibrator.

4. The improved diesel engine exhaust particulate trap according to claim 1, wherein The filter cartridge (4) is a cylindrical body made by winding and sintering multiple layers of stainless steel filter meshes.

5. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, The filter cartridge (4) is a frustum-shaped body made by winding and sintering multiple layers of stainless steel filter meshes.

6. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, A filter cartridge end sleeve (15) is installed at the open end of the filter cartridge (4). The side of the filter cartridge end sleeve (15) is a sleeve with an external thread. The vent holes (5-1) of the connecting plate (5) are provided with internal threads that match the external thread of the filter cartridge end sleeve (15), and the connecting plate (5) and the filter cartridge end sleeve (15) are fixedly connected by threads.

7. The improved diesel engine exhaust particulate trap according to claim 6, wherein, A sealing gasket (16) is provided between the filter cartridge end sleeve (15) and the bottom surface of the connecting plate (5).

8. The improved diesel engine exhaust particulate trap according to claim 1, wherein A filter cartridge bottom support (14) is further provided at the closed side end of the filter cartridge (4). The filter cartridge bottom support (14) is circular. The filter cartridge bottom support (14) is fixedly connected to the closed side end of the filter cartridge (4). A tool connection end is provided on the filter cartridge bottom support (14), and the tool connection end is used for externally rotating the filter cartridge (4) for installation.

9. The improved diesel engine exhaust particulate trap according to claim 8, wherein, The tool connection end on the filter cartridge bottom support (14) is a square hole (14-1), and a square column (14-2) is inserted into the square hole (14-1).

10. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, It further includes a differential pressure monitor (8). The differential pressure monitor (8) includes a front air nozzle (8-1), a front air pipe (8-2), a differential pressure transmitter (8-3), a rear air pipe (8-4), and a rear air nozzle (8-5). The front air nozzle (8-1) is provided on the side wall of the exhaust gas inlet end of the particulate filter housing (1), and the front air nozzle (8-1) communicates with the inside of the particulate filter housing (1). One end of the front air pipe (8-2) is connected to the front air nozzle (8-1), and the other end of the front air pipe (8-2) is connected to the differential pressure transmitter (8-3). The rear air nozzle (8-5) is provided on the side wall of the exhaust gas outlet end of the particulate filter housing (1), and the rear air nozzle (8-5) communicates with the inside of the housing. One end of the rear air pipe (8-4) is connected to the rear air nozzle (8-5), and the other end of the rear air pipe (8-4) is connected to the differential pressure transmitter (8-3).

11. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, It further includes a controller (9). The controller (9) is electrically connected to the vibration device (7). A differential pressure threshold alarm lamp (9-1), a vibration intensity regulator (9-2), and a vibration start button (9-3) are provided on the controller (9).

12. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, An optoelectronic switch (12) and a dust bin full alarm lamp (13) are provided on the upper part of the side wall of the dust hopper (6), and the optoelectronic switch (12) and the dust bin full alarm lamp (13) are electrically connected.

13. The improved diesel engine exhaust particulate trap according to claim 1, wherein, The tail gas inlet pipe (2) is arranged at the end of the tail gas inlet end of the particulate trap housing (1), and a first clamp (10) is provided to connect the tail gas inlet pipe (2) and the particulate trap housing (1); The side wall of the tail gas inlet end of the particulate trap housing (1) is connected to the ash hopper (6) through a second clamp (11).

14. The improved diesel engine exhaust particulate trap according to claim 1, characterized in that, The tail gas inlet pipe (2) is arranged on the side wall of the tail gas inlet end of the particulate trap housing (1); The end of the tail gas inlet end of the particulate trap housing (1) is connected to the ash hopper (6) through a second clamp (11).

15. An exhaust gas aftertreatment system, comprising the improved diesel engine exhaust particulate trap according to any one of claims 1-14, characterized in that, The tail gas outlet end of the particulate trap housing (1) is connected to an oxidation catalytic converter housing (17), and an oxidation catalytic converter (18) is arranged in the internal space of the oxidation catalytic converter housing (17).

16. The post-treatment system for exhaust gas according to claim 15, characterized in that, The tail gas outlet end of the particulate trap housing (1) is provided with a flanging, the end of the oxidation catalytic converter housing (17) is provided with a flanging, and a third clamp (19) is provided to connect the particulate trap housing (1) and the oxidation treatment housing (17) through the third clamp (19).

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