CN115573793A

CN115573793A - Particulate filter and extrusion die

Info

Publication number: CN115573793A
Application number: CN202211216206.9A
Authority: CN
Inventors: 袁林峰; 约翰尼·马切尔; 尼古拉·霍恩斯科夫
Original assignee: Nanjing Hanshen Material Technology Co ltd; Landerson Emission Technology Co ltd
Current assignee: Nanjing Hanshen Material Technology Co ltd; Landerson Emission Technology Co ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2023-01-06
Also published as: WO2024067362A1

Abstract

The invention discloses a particulate filter and an extrusion die. The particle filter comprises a body, wherein a plurality of inlet channels and a plurality of outlet channels are arranged in the body, the inlet channels and the outlet channels are adjacently arranged, the inlet channels are not connected, the outlet channels are not connected, the hydraulic diameter of the inlet channels is larger than that of the outlet channels, the body between the two adjacent channels forms the pipe walls of the channels, and the pipe walls of the channels, the extension lines of which are positioned on the same straight line, have the same thickness. The particle filter has asymmetric channels, but the thickness of the tube wall of a plurality of the channels with extension lines positioned on the same line is equivalent, so that the particle filter can adopt the traditional electric spark cutting to produce an extrusion die, thereby having good filtering performance and lower production cost, and simultaneously being capable of easily obtaining large filter size.

Description

Particulate filter and extrusion die

Technical Field

The present invention relates to the field of materials, in particular, to particulate filters and extrusion dies.

Background

Particulate filters, such as Diesel Particulate Filters (DPFs), are important components installed in diesel vehicle exhaust systems to reduce Particulate Matter (PM) emissions by mechanically separating/trapping particulates in the exhaust gas. The filtering of a DPF is accomplished by passing the exhaust gas through a porous media that allows only particulate of a particular size to pass through. Thus, particles passing through the pores of the media will pass through the filter, while oversized particles remain within the filter. It will therefore be appreciated that over time, soot and ash build-up within the filtration channels, and in particular the inlet channels, can occur, resulting in a restricted flow through the filter and ultimately an increased back pressure in the system. Most of the present DPFs use a symmetrical channel cross-section, in which the inlet channels are of the same size as the outlet channels. The symmetrical structure DPF is constantly catched PM in the use, and after the PM is catched to a certain degree, the increase of backpressure can be very big, and the increase of backpressure can influence the oil consumption and the power of car. Although the above problem can be alleviated to some extent by using a DPF of asymmetric construction, where the inlet and outlet channels are of different sizes, the inlet channel has a larger area, which in turn allows for a higher soot loading per unit pore density, which can reduce the impact of soot loading on back pressure, but at the cost of increased initial back pressure.

However, since the channel walls of the DPF have an asymmetric structure, the DPF cannot be manufactured by using a conventional Electric Discharge Machine (EDM) and requires a special tool. This special tool has a series of disadvantages, resulting in high manufacturing cost, difficult manufacturing, time consuming and difficult amplification. Thus, the current particulate filters and extrusion dies remain to be improved.

Disclosure of Invention

The present invention aims to alleviate or even solve at least one of the above problems to some extent.

In one aspect of the invention, a particulate filter is provided. The particle filter comprises a body, wherein a plurality of inlet channels and a plurality of outlet channels are arranged in the body, the inlet channels and the outlet channels are adjacently arranged, the inlet channels are not connected, the outlet channels are not connected, the hydraulic diameter of the inlet channels is larger than that of the outlet channels, the body between the two adjacent channels forms the pipe walls of the channels, and the pipe walls of the channels, the extension lines of which are positioned on the same straight line, have the same thickness. The particle filter has asymmetrically-structured channels, but the walls of a plurality of said channels, which extend in the same line, are of such a thickness that the particle filter can be produced using conventional spark-cutting extrusion dies, thus having good filtering properties and low production costs, while at the same time large filter sizes can be obtained relatively easily.

According to the embodiment of the invention, the pipe walls of a plurality of other channels are uniformly distributed on the extension line of any pipe wall of the channel. Therefore, the production difficulty of an extrusion die for generating the filter can be reduced, and the production cost of the particle filter can be reduced.

According to an embodiment of the invention, the thickness of the wall of the inlet channel and the thickness of the wall of the outlet channel are comparable. Thereby, the production cost of the particulate filter can be further reduced.

According to an embodiment of the invention, the ratio of the area of the inlet channel and the outlet channel is 1.2-2. Thereby, the performance of the particulate filter can be further improved.

According to an embodiment of the invention, the ratio of the area of the inlet channel and the outlet channel is 1.3-1.6. Thereby, the performance of the particulate filter can be further improved.

According to an embodiment of the invention, the inlet channel and the outlet channel are triangular in cross-section in a direction perpendicular to the direction of extension of the channels. Thus, an asymmetrical structure in which the inlet channels and the outlet channels are alternately arranged can be easily constructed.

According to an embodiment of the invention, the inlet channel and the outlet channel are each equilateral triangular in cross-section. Thereby, the performance of the particulate filter can be further improved.

According to the embodiment of the invention, the plurality of channels are arranged in multiple rows and multiple columns, one of two adjacent channels in the same row is the inlet channel, the other one is the outlet channel, and the cross sections of the adjacent inlet channels and the adjacent outlet channels form a parallelogram together in the direction perpendicular to the extending direction of the channels. Thereby, the performance of the particulate filter can be further improved.

According to the embodiment of the invention, one of two adjacent channels in the same column is the inlet channel, and the other is the outlet channel, and the cross sections of the adjacent inlet channels and the adjacent outlet channels form a diamond shape in the direction perpendicular to the extending direction of the channels. Thereby, the performance of the particulate filter can be further improved.

According to the embodiment of the invention, the difference between the side length of the triangular inner wall of the inlet channel and the side length of the triangular inner wall of the outlet channel is smaller than the thickness of the pipe wall. Therefore, the pipe walls of the asymmetric structure can be simply and conveniently ensured to be formed by straight lines, and the production cost of the particle filter can be further reduced.

According to an embodiment of the invention, the particulate filter satisfies at least one of the following conditions: the thickness of the pipe wall of the channel is 100-10000 microns, preferably 200-1000 microns; the volume density of the particle filter is 0.45-0.8kg/L; the hydraulic diameter of the inlet channel is 100-10000 microns, preferably 900-1800 microns. Thereby, the performance of the particulate filter can be further improved.

According to an embodiment of the invention, the body is formed by a porous medium. Thereby, the performance of the particulate filter can be further improved.

According to an embodiment of the invention, the inlet channel has a first end and a second end, the first end is an inlet of the medium to be filtered, and the second end is a closed structure; the outlet channel is provided with a third end and a fourth end, the fourth end is an outlet of a medium to be filtered, the third end is of a closed structure, the first end and the third end are located on the same side, the second end and the fourth end are located on the same side, and the medium to be filtered can pass through the pipe wall between the inlet channel and the outlet channel and flows to the outlet of the filtering medium from one side of the inlet of the filtering medium. Thereby, the performance of the particulate filter can be further improved.

In another aspect of the invention, an extrusion die for making a particulate filter is provided. The mold comprises: the die comprises a die body, a die body and a die core, wherein the die body is provided with a feeding hole; the first forming parts and the second forming parts are arranged adjacently, the first forming parts are not connected, the second forming parts are not connected, the hydraulic diameter of the first forming parts is larger than that of the second forming parts, the feeding holes are positioned between the two adjacent forming parts, the distance between the two adjacent forming parts forms the pipe wall of the particle filter to be extruded, and the sizes and the positions of the first forming parts and the second forming parts are configured to enable the thicknesses of the pipe walls with extension lines positioned on the same straight line to be equivalent. The extrusion die can simply form the particle filter, and is beneficial to reducing the production cost of the particle filter.

According to an embodiment of the invention, the extrusion die is configured for preparing a particulate filter as described above.

According to an embodiment of the invention, the extrusion die is formed by cutting with an electric discharge machine. Thereby, the cost for forming the extrusion die can be further reduced, which is advantageous for reducing the production cost for producing the aforementioned particulate filter.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic view showing a structure of a particulate filter in the related art;

FIG. 2 is a schematic view showing a structure of another particulate filter in the related art;

FIG. 3 shows a schematic structural diagram of a particulate filter according to one embodiment of the present invention;

FIG. 4 shows a schematic structural diagram of a particulate filter according to another embodiment of the present invention;

FIG. 5 shows a schematic structural diagram of a particulate filter according to yet another embodiment of the present invention;

FIG. 6 shows a schematic structural diagram of a particulate filter according to yet another embodiment of the present invention;

FIG. 7 shows a schematic partial structural view of a particulate filter according to one embodiment of the present invention;

fig. 8 shows a schematic structural view of an extrusion die for manufacturing a particulate filter according to an embodiment of the present invention.

Description of the drawings:

1000: a particulate filter; 100: a body; 110: an inlet channel; 120: an outlet channel; 2000: extruding the mould; 1: a feed aperture; 2: a first molded member; 3: a second molding member.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

For convenience of understanding, the following first briefly explains the principle that the present application can achieve the above-mentioned advantageous effects:

as described above, referring to fig. 1, in a symmetric Diesel Particulate Filter (DPF), since the areas of the inlet channels 110 'and the outlet channels 120' are the same, after a period of use, the actual flow rate of the inlet channels is reduced due to the accumulation of soot and the like in the inlet channels, which leads to a problem of an increase in the back pressure of the system. Although the related art has adopted an asymmetrical design of the inlet channel and the outlet channel to solve the problem that the back pressure of the system is increased due to the flow rate reduction caused by the accumulation of soot and other substances in the inlet channel after the DPF is used for a period of time, referring to fig. 2, that is, the area of the inlet channel is larger than that of the outlet channel. However, in addition to the above-mentioned problems of difficult processing, the asymmetric channel structure also limits the size of the DPF product: referring to fig. 1, the inlet and outlet pipe walls of a conventional symmetrical DPF structure are also symmetrical, i.e., the pipe walls of a plurality of inlets and outlets are defined by a plurality of intersecting straight lines. The asymmetric structure causes the pipe wall between the inlet and the outlet of two adjacent rows to bend due to the asymmetric area of the outlet and the inlet. Referring to fig. 2, the pipe wall of the DPF is not formed by a plurality of straight lines, and there is an inflection point in the extending direction of the pipe wall. This structure can cause additional stress to the DPF substrate, which in turn can cause the pipe wall at that location to crack more easily. And as the size difference between the inlet and outlet channels increases, the thickness of the wall intersection decreases, further reducing the thermal and mechanical strength of the particulate filter body.

The particle filter provided by the invention designs the structures of the inlet channel and the outlet channel, so that the thicknesses of the pipe walls of a plurality of channels with extension lines positioned on the same straight line can be equivalent while the hydraulic diameter of the inlet channel is ensured to be larger than that of the outlet channel. Specifically, referring to fig. 3, by modifying the cross-sectional shapes of the inlet channels (110A and 110B as shown in the drawing) and the outlet channels 120 of the particulate filter 1000, the portion of the body 100 between the channels can still be made of a straight line structure, so that on one hand, the problem of difficulty in molding due to the pipe wall having an inflection point can be avoided, and on the other hand, the design can make the thicknesses (d as shown in the drawing) of the pipe walls of a plurality of the channels whose extension lines are on the same straight line comparable. Therefore, the problem of stress increase caused by the change of the pipe wall thickness at the inflection point can be solved, and the service life of the particle filter is further prolonged.

The specific structure of the particulate filter will be described in detail below according to a specific embodiment of the present invention:

according to the embodiment of the invention, referring to fig. 4, the pipe wall of a plurality of other channels is uniformly distributed on the extension line of any pipe wall of the channel. Specifically, the extension lines of the tube walls between the inlet channel 110A and the outlet channel 120C may be distributed with the tube walls between the inlet channel 110C and the outlet channel 120B. Similarly, the body of the proposed particulate filter may constitute a plurality of intersecting straight lines defining a plurality of inlet and outlet channels, i.e. the main body 100 of the particulate filter of the invention may be constituted by a plurality of intersecting straight lines, the main body 100 not having fold lines and inflection points. Therefore, the production difficulty of an extrusion die for generating the filter can be reduced, and the production cost of the particle filter can be reduced.

According to an embodiment of the present invention, referring to fig. 4, the tube wall thickness of the inlet channels (110A-110C as shown in the figure) and the tube wall thickness of the outlet channels (120A-120C as shown in the figure) are comparable, e.g. in particular, the tube wall thickness d of the inlet channel 110B may coincide with the tube wall thickness of the outlet channel 120B, more particularly, the tube wall thickness of any one of the plurality of inlet channels may coincide with the tube wall thickness of any one of the plurality of outlet channels. In other words, the body of the particulate filter according to the embodiment of the present invention may be formed by intersecting a plurality of straight lines having a uniform thickness. Thereby, the production cost of the particulate filter can be further reduced, and the extrusion die for manufacturing the particulate filter can be manufactured by relying on the technology of the extrusion die for manufacturing the symmetrically structured particulate filter in the related art, that is, using a conventional Electric Discharge Machine (EDM). Moreover, the body of the particle filter formed by the crossed straight lines with the same thickness is beneficial to improving the overall mechanical strength of the particle filter, and further can improve the overall diameter and size of the particle filter which can be prepared.

According to the embodiment of the present invention, the specific size, area, and shape of the inlet passage and the outlet passage are not particularly limited as long as the above-described functions can be achieved. For example, according to some embodiments of the invention, the ratio of the area of the inlet channel to the area of the outlet channel may be 1.2 to 2. For example, it may be 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 2, etc. In particular, the ratio of the areas of the inlet channel and the outlet channel may range from 1.3 to 1.6, in particular from 1.25 to 1.75, in particular 1.56. Thereby, the performance of the particulate filter can be further improved. The inventors have found that when the above-mentioned ratio range is too large, the actual filtering effect of the particulate filter will be affected because the area of the inlet channels is substantially larger than the area of the outlet channels: too small an outlet passage area may result in a large initial back pressure of the system and a low filtration efficiency; when the ratio of the inlet channel to the outlet channel is too small, i.e., the inlet channel is larger than the outlet channel by a small amount, it is difficult to solve the problem of back pressure rise due to the accumulation of soot and the like in the inlet channel after a period of use.

According to an embodiment of the invention, referring to fig. 3-6, the inlet channel and the outlet channel are triangular in cross-section in a direction perpendicular to the direction in which the channels extend. Thus, an asymmetrical structure in which the inlet channels and the outlet channels are alternately arranged can be easily constructed. More specifically, with reference to fig. 4, the inlet channel and the outlet channel are each equilateral triangular in cross-section: taking the inlet passage 110C as an example, the lengths of the three inner side edges a constituting the cross section of the inlet passage 110C may be equal. The lengths of the three inner side edges b in the cross-section of the outlet channel 120C may be equal. Therefore, the performance of the particle filter can be further improved, the lengths of the edges of the inlet channel and the outlet channel are equal, and the stress conditions of the edges are consistent in the use process of the particle filter, so that the service life of the particle filter is prolonged.

Referring to fig. 5, a plurality of channels are arranged in a plurality of rows and a plurality of columns according to an embodiment of the present invention. One of two adjacent channels in the same row is an inlet channel (e.g., 110A), and the other is an outlet channel (e.g., 120C), and the cross sections of the adjacent inlet channels and the outlet channels form a parallelogram (as shown by the dashed boxes in the figure) in the direction perpendicular to the extending direction of the channels. From this, can be under the prerequisite of guaranteeing that the pipe wall between a plurality of entrances and the export comprises crossing many straight lines, save the area that entry and exit channel occupy to can hold more entry and exit channel down in unit volume's particle filter, and then can promote this particle filter's filter effect.

According to an embodiment of the present invention, referring to fig. 6, one of two adjacent channels in the same column is the inlet channel (110A as shown in the figure) and the other is the outlet channel (120A as shown in the figure), and the cross sections of the adjacent inlet and outlet channels form a diamond shape (as shown by the dashed box in the figure) in a direction perpendicular to the extending direction of the channels. Thereby, the performance of the particulate filter can be further improved.

According to an embodiment of the invention, the particulate filter satisfies at least one of the following conditions: the thickness of the pipe wall of the channel is 100-10000 microns; the volume density of the particle filter is 0.45-0.8kg/L; the hydraulic diameter of the inlet channel is 100-10000 microns. Thereby, the performance of the particulate filter can be further improved. The particulate filter may meet any one, two, or all three of the aforementioned requirements. The inventors have found that a particulate filter can have better filtration performance when it meets the aforementioned requirements. For example, according to some examples of the invention, the walls of the channels have a thickness of 200-1000 microns and the inlet channels have a hydraulic diameter of 900-1800 microns. In particular, when the hydraulic diameter of the inlet channels is 900-1800 microns, the channel diameter of the particulate filter is modest, reducing the space occupied by the required cross-section while the back pressure is relatively low. When the bulk density is within the above range, the filtration area is moderate, and the high soot loading capacity and the low back pressure can be maintained. When the thickness of the pipe wall is within the above range, the mechanical strength can be maintained without significantly increasing the back pressure. Thus, the particulate filter may have a better overall performance.

According to an embodiment of the present invention, the specific material of the body 100 is not particularly limited, and a person skilled in the art may select a familiar material to construct the body 100 of the particulate filter. For example, according to some embodiments of the present invention, the body 100 may be formed of a porous medium. More specifically, the material of the body 100 may be any material that can be used to filter gas and trap particles such as soot. For example, the material of the body 100 may be recrystallized silicon carbide. The material has good high-temperature mechanical property, high-temperature tolerance, high compactness, good mechanical property and long service life, and is particularly suitable for preparing filter bodies such as Diesel Particulate Filters (DPF) which need to continuously work in a certain temperature environment. According to an embodiment of the present invention, referring to fig. 7, the inlet passage 110 may have a first end that is an inlet of the medium to be filtered (as shown by the arrow in the figure) and a second end that is a closed structure. The outlet channel 120 has a third end and a fourth end, the fourth end being the outlet for the media to be filtered (as indicated by the arrows in the figure), and the third end being of closed configuration. The first end and the third end are located on the same side, the second end and the fourth end are located on the same side, and the medium to be filtered can flow from the inlet side of the filter medium to the outlet of the filter medium through the pipe wall between the inlet channel and the outlet channel. Thus, air containing particles such as soot and the like entering the interior of the particulate filter through the first end of the inlet passage 110 may pass through the wall of the duct between the inlet passage 110 and the outlet passage 120 into the side of the outlet passage 120 and eventually be discharged, while particles such as soot and the like are trapped in the inlet passage 110 closed at the second end. Thereby, the performance of the particulate filter can be further improved.

In general, the particle filter has the advantages that the particle filter is convenient to produce due to the fact that the particle filter adopts an asymmetric structure and the body is formed by the straight lines which are crossed, and a die for extruding the particle filter does not need to be additionally designed. Moreover, the wall of each channel in the particle filter has uniform thickness and uniform stress distribution, so that the particle filter with relatively large volume can be formed, and the service life is ensured. In addition, the particulate filter has a low back pressure, so that the pressure loss inside the exhaust pipe to which the particulate filter is applied can be reduced, thereby enabling a vehicle to which the particulate filter is applied to have high fuel efficiency. In addition, the particulate filter has at least one of the advantages of good soot loading capacity, long maintenance interval, small influence on back pressure along with the lapse of service time, good heat resistance, high mechanical strength and the like.

In another aspect of the invention, the invention provides an extrusion die for making a particulate filter. Referring to fig. 8, the mold includes: a die body 2000 having a feed hole 1 thereon. The die also comprises a plurality of first forming parts 2 and a plurality of second forming parts 3, wherein the first forming parts and the second forming parts are arranged adjacently, the first forming parts are not connected, the second forming parts are not connected, the hydraulic diameter of the first forming parts is larger than that of the second forming parts, the feeding holes are arranged between the two adjacent forming parts, the distance between the two adjacent forming parts forms the pipe wall of the particle filter to be extruded, and the sizes and the positions of the first forming parts and the second forming parts are configured to enable the thicknesses of the pipe walls with extension lines on the same straight line to be equivalent. The extrusion die can simply form the particle filter, and is beneficial to reducing the production cost of the particle filter.

In particular, the first profile piece can be used to form the aforementioned inlet channel in the particle filter, and the second profile piece can be used to form the aforementioned outlet channel of the particle filter. It will be appreciated by those skilled in the art that the extrusion die described above may be used to form the particulate filter described above. As described in detail above with respect to the structure and advantages of the particulate filter, the extrusion die has first and second molding members for forming inlet and outlet passages of the particulate filter, and thus the first and second molding members may have the same features as the inlet and outlet passages, which will not be described in detail herein.

Specifically, referring to fig. 8, the first molding member 2 and the second molding member 3 on the extrusion die 2000 are arranged adjacently, the first molding members are not connected with each other, the second molding members are not connected with each other, the hydraulic diameter of the first molding member is larger than that of the second molding member, the feeding hole 1 is located between the two molding members, the distance between the two adjacent molding members constitutes the pipe wall of the particulate filter to be extruded, and the size and the position of the first molding member and the second molding member are configured such that the thicknesses of the pipe walls whose extension lines are located on the same straight line are equivalent. Extrusion dies according to embodiments of the present invention may be formed by conventional electric discharge machine cutting. Thereby, the cost for forming the extrusion die can be further reduced, which is advantageous for reducing the production cost for producing the aforementioned particulate filter.

In the description of the present invention, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description herein, references to the description of "one embodiment," "another embodiment," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction. In addition, it should be noted that the terms "first" and "second" in this specification are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A particulate filter comprising a body having a plurality of inlet channels and a plurality of outlet channels therein, the inlet channels and the outlet channels being arranged adjacent to one another without the inlet channels being contiguous and the outlet channels being non-contiguous, the inlet channels having a hydraulic diameter greater than the hydraulic diameter of the outlet channels, the body between two adjacent channels defining walls of the channels,

the thicknesses of the pipe walls of a plurality of channels with extension lines positioned on the same straight line are equivalent.

2. The particulate filter of claim 1 wherein a plurality of walls of other of said channels are distributed on an extension of any one of said walls of said channel.

3. The particulate filter of claim 1 wherein a wall thickness of the inlet passage is comparable to a wall thickness of the outlet passage.

4. The particulate filter of claim 1 wherein a ratio of the areas of the inlet channels and the outlet channels is between 1.2 and 2.

5. The particulate filter of claim 4 wherein the ratio of the area of the inlet passage to the area of the outlet passage is 1.3 to 1.6.

6. The particulate filter of any one of claims 1-5 wherein the inlet channel and the outlet channel are triangular in cross-section in a direction perpendicular to the direction of extension of the channels.

7. The particulate filter of claim 6 wherein the inlet passage and the outlet passage are each equilateral triangle in cross-section.

8. The particulate filter of claim 7 wherein a plurality of the channels are arranged in a plurality of rows and columns, one of two adjacent channels in a same row being the inlet channel and the other being the outlet channel, and wherein cross-sections of adjacent inlet and outlet channels in a direction perpendicular to a direction of extension of the channels collectively form a parallelogram.

9. The particulate filter of claim 8 wherein one of two adjacent channels in the same row is the inlet channel and the other is the outlet channel, and wherein cross-sections of adjacent inlet and outlet channels in a direction perpendicular to a direction of extension of the channels collectively form a diamond shape.

10. A particle filter as set forth in any one of claims 7-9, characterized in that the difference between the side length of the triangular inner wall of the inlet channel and the side length of the triangular inner wall of the outlet channel is smaller than the thickness of the tube wall.

11. The particulate filter of claim 1, wherein the particulate filter satisfies at least one of the following conditions:

the thickness of the pipe wall of the channel is 100-10000 microns, preferably 200-1000 microns;

the volume density of the particle filter is 0.45-0.8kg/L;

the hydraulic diameter of the inlet channel is 100-10000 microns, preferably 900-1800 microns.

12. The particulate filter of claim 1, wherein the body is formed of porous media.

13. The particulate filter of claim 12 wherein the inlet passage has a first end and a second end, the first end being an inlet for media to be filtered and the second end being a closed structure;

the outlet channel is provided with a third end and a fourth end, the fourth end is an outlet of the medium to be filtered, the third end is a closed structure,

the first end and the third end are located on the same side, the second end and the fourth end are located on the same side,

and the medium to be filtered can flow from the side of the inlet of the filter medium to the outlet of the filter medium through the pipe wall between the inlet channel and the outlet channel.

14. An extrusion die for making a particulate filter, comprising:

the die comprises a die body, a die body and a die core, wherein the die body is provided with a feeding hole;

the first forming parts and the second forming parts are arranged adjacently, the first forming parts are not connected, the second forming parts are not connected, the hydraulic diameter of the first forming parts is larger than that of the second forming parts, the supply holes are positioned between the two adjacent forming parts, the spacing between the two adjacent forming parts forms the pipe wall of the particulate filter to be extruded, and the sizes and the positions of the first forming parts and the second forming parts are configured to enable the thicknesses of the pipe wall with extension lines positioned on the same straight line to be equivalent.

15. The extrusion die of claim 14, wherein the extrusion die is configured for preparing the particulate filter of any one of claims 1-13.

16. The extrusion die of claim 14, wherein the extrusion die is formed by electric discharge machine cutting.