CN220609582U - Honeycomb filter - Google Patents
Honeycomb filter Download PDFInfo
- Publication number
- CN220609582U CN220609582U CN202320909971.2U CN202320909971U CN220609582U CN 220609582 U CN220609582 U CN 220609582U CN 202320909971 U CN202320909971 U CN 202320909971U CN 220609582 U CN220609582 U CN 220609582U
- Authority
- CN
- China
- Prior art keywords
- partition wall
- honeycomb filter
- equivalent circle
- pores
- honeycomb
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005192 partition Methods 0.000 claims abstract description 123
- 239000011148 porous material Substances 0.000 claims abstract description 102
- 238000007789 sealing Methods 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 16
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 6
- 229910052753 mercury Inorganic materials 0.000 claims description 6
- 239000012530 fluid Substances 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims 1
- 239000003054 catalyst Substances 0.000 abstract description 42
- 239000000463 material Substances 0.000 abstract description 25
- 229910052878 cordierite Inorganic materials 0.000 abstract description 10
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 abstract description 10
- 230000000630 rising effect Effects 0.000 abstract 1
- 238000011156 evaluation Methods 0.000 description 32
- 239000007789 gas Substances 0.000 description 31
- 230000000052 comparative effect Effects 0.000 description 17
- 238000005259 measurement Methods 0.000 description 11
- 239000002245 particle Substances 0.000 description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 8
- 239000002994 raw material Substances 0.000 description 7
- 239000005995 Aluminium silicate Substances 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 6
- 235000012211 aluminium silicate Nutrition 0.000 description 6
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 6
- 238000000746 purification Methods 0.000 description 6
- 238000001125 extrusion Methods 0.000 description 5
- 239000013618 particulate matter Substances 0.000 description 5
- 230000002093 peripheral effect Effects 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- 239000004071 soot Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000010304 firing Methods 0.000 description 4
- 238000010191 image analysis Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 239000000454 talc Substances 0.000 description 3
- 229910052623 talc Inorganic materials 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 244000299461 Theobroma cacao Species 0.000 description 2
- 235000009470 Theobroma cacao Nutrition 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000002459 porosimetry Methods 0.000 description 2
- 238000000638 solvent extraction Methods 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000011369 resultant mixture Substances 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000002341 toxic gas Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Filtering Materials (AREA)
Abstract
The utility model provides a honeycomb filter, which can improve the trapping efficiency and inhibit the pressure loss from rising when a catalyst for purifying exhaust gas is loaded. The honeycomb filter includes: a columnar honeycomb structure (4) having porous partition walls (1) arranged so as to surround a plurality of cells (2); and a hole sealing part (5) which is arranged at either end of the compartment (2), wherein the partition wall (1) is composed of a material containing cordierite as a main component, the porosity of the partition wall (1) is 60-70%, the ratio (S2/S1×100%) of the sum S2 of the opening areas of pores having equivalent circle diameters exceeding 3 μm in each unit surface area S1 of the partition wall (1) is 58-70%, and the ratio (R/D) of the average opening equivalent circle diameter R (μm) of pores having equivalent circle diameters exceeding 3 μm in the surface of the partition wall (1) to the average pore diameter D (μm) of the partition wall (1) is 0.3-0.8.
Description
Technical Field
The present utility model relates to a honeycomb filter. More specifically, the present utility model relates to a honeycomb filter capable of improving the trapping efficiency and suppressing the increase of the pressure loss when a catalyst for purifying exhaust gas is supported.
Background
Conventionally, as a filter for trapping particulate matter in exhaust gas discharged from an internal combustion engine such as an engine of an automobile or a device for purifying toxic gas components such as CO, HC, NOx, there have been known: a honeycomb filter using a honeycomb structure (see patent document 1). The honeycomb structure has partition walls made of porous ceramics such as cordierite, and a plurality of cells are partitioned by the partition walls. In the honeycomb filter, the honeycomb structure is provided with plugged portions so that openings on the inflow end face side and openings on the outflow end face side of the cells are alternately plugged. That is, the honeycomb filter has the structure: the inflow cells whose inflow end face side is open and whose outflow end face side is sealed and the outflow cells whose inflow end face side is sealed and whose outflow end face side is open are alternately arranged with the partition wall interposed therebetween. In the honeycomb filter, porous partition walls function as: filtering action for trapping particulate matter in exhaust gas. Hereinafter, particulate matter contained in the exhaust gas may be referred to as "PM". "PM" is an abbreviation for "particulate matter".
The purification of exhaust gas by the honeycomb filter is performed as follows. First, the honeycomb filter is configured to: the inflow end face side thereof is located on the upstream side of the exhaust system from which the exhaust gas is discharged. The exhaust gas flows into the cells from the inflow end face side of the honeycomb filter. The exhaust gas flowing into the inflow cells passes through the porous partition walls, flows into the outflow cells, and is discharged from the outflow end face of the honeycomb filter. PM and the like in the exhaust gas are trapped and removed when passing through the porous partition walls. In addition, such a honeycomb filter may be loaded with: an oxidation catalyst for promoting PM oxidation (combustion), an exhaust gas purifying catalyst for purifying harmful components such as NOx, and the like.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2002-219319
Disclosure of Invention
In recent years, exhaust gas restrictions for automobiles are strict year by year, and there is a need to improve the performance of honeycomb filters for exhaust gas purification. For example, in order to improve the PM trapping performance, it is considered to reduce the average pore diameter of porous partition walls. On the other hand, as described above, the honeycomb filter may be used so as to support an exhaust gas purifying catalyst (hereinafter also simply referred to as "catalyst") or the like. When the honeycomb filter is used with a catalyst supported thereon, it is desirable that the pore diameters of pores on the surfaces of the partition walls be as large as possible in order to reduce pressure loss after the catalyst is supported and to facilitate the support of the catalyst in the pores of the partition walls.
However, if the opening diameters of the pores at the surfaces of the partition walls are increased, large pits remain on the surfaces of the partition walls after the catalyst is supported, and the trapping performance of the honeycomb filter may be deteriorated. In addition, as a measure for improving the trapping performance of the honeycomb filter, a method of supporting the catalyst in a layer form on the surface of the partition wall has been studied, but if the opening diameter of the pores at the surface of the partition wall is increased as described above, the surface of the partition wall cannot be completely covered with the catalyst, and the effect of improving the trapping performance by the supported catalyst is reduced. On the other hand, if the pore diameter of the entire partition wall is reduced in view of improvement of the trapping performance, the flow path of the exhaust gas flow path in the partition wall is likely to be blocked, and the pressure loss increases after the catalyst is supported.
The present utility model has been made in view of the above-described problems of the prior art. According to the present utility model, there is provided a honeycomb filter capable of improving the trapping efficiency and suppressing the increase of the pressure loss when a catalyst for purifying exhaust gas is supported.
According to the present utility model, there is provided a honeycomb filter shown below.
[1] A honeycomb filter, comprising:
a columnar honeycomb structure having porous partition walls arranged to surround a plurality of cells, the plurality of cells forming fluid flow paths extending from an inflow end face to an outflow end face; and
a porous sealing portion disposed at either one of an end portion on the inflow end face side and an end portion on the outflow end face side of the cell,
the partition wall is composed of a material containing cordierite as a main component,
the porosity of the partition wall is 60-70%,
the ratio (S2/S1.times.100%) of the sum S2 of the opening areas of pores having equivalent circle diameters exceeding 3 μm in the unit surface area S1 of the partition walls to the unit surface area S1 is 58 to 70%,
the ratio (R/D) of the average opening equivalent circle diameter R (μm) of the pores having an equivalent circle diameter exceeding 3 μm present at the surface of the partition wall, which is measured by mercury intrusion method, to the average pore diameter D (μm) of the partition wall is 0.3 to 0.8.
[2] The honeycomb filter according to the above [1], wherein the ratio (S3/S2X 100%) of the sum S3 of the opening areas of pores having an equivalent circle diameter of 40 μm or more in the unit surface area S1 to the sum S2 of the opening areas of pores having an equivalent circle diameter exceeding 3 μm in the unit surface area S1 is 3 to 5%.
[3] The honeycomb filter according to [1] or [2], wherein the pore depth of the pores at the surface of the partition wall obtained by a laser microscope is 1.0 to 3.0 μm.
[4] The honeycomb filter according to any one of [1] to [3], wherein the partition wall has a thickness of 190.5 to 254 μm.
Effects of the utility model
The honeycomb filter of the present utility model can improve the trapping efficiency and suppress the increase of the pressure loss when the catalyst for purifying exhaust gas is supported.
Drawings
Fig. 1 is a perspective view schematically showing an embodiment of the honeycomb filter of the present utility model.
Fig. 2 is a plan view showing the inflow end face side of the honeycomb filter shown in fig. 1.
Fig. 3 is a sectional view schematically showing a section A-A' of fig. 2.
Description of the reference numerals
1: partition wall, 2: compartment, 2a: inflow compartment, 2b: outflow compartment, 3: peripheral wall, 4: honeycomb structure, 5: hole sealing portion, 11: inflow end face, 12: outflow end face, 100: a honeycomb filter.
Detailed Description
Hereinafter, embodiments of the present utility model will be described, but the present utility model is not limited to the following embodiments. Thus, it should be understood that: the following embodiments are appropriately modified and improved based on the general knowledge of those skilled in the art within the scope of the present utility model without departing from the gist of the present utility model.
(1) Honeycomb filter:
one embodiment of the honeycomb filter of the present utility model is a honeycomb filter 100 shown in fig. 1-3. Here, fig. 1 is a perspective view schematically showing an embodiment of the honeycomb filter of the present utility model. Fig. 2 is a plan view showing the inflow end face side of the honeycomb filter shown in fig. 1. Fig. 3 is a sectional view schematically showing a section A-A' of fig. 2.
As shown in fig. 1 to 3, the honeycomb filter 100 includes a honeycomb structure 4 and a plugged portion 5. The honeycomb structure 4 has a columnar shape and includes porous partition walls 1 arranged to surround a plurality of cells 2, and the plurality of cells 2 form fluid flow paths extending from an inflow end face 11 to an outflow end face 12. In the honeycomb filter 100, the honeycomb structure 4 has a columnar shape and has an outer peripheral wall 3 on its outer peripheral side surface. That is, the outer peripheral wall 3 is provided with: surrounding the partition walls 1 arranged in a lattice shape.
The hole sealing portion 5 is disposed in an opening portion of each cell 2 on the inflow end face 11 side or the outflow end face 12 side. In the honeycomb filter 100 shown in fig. 1 to 3, the plugging portions 5 are disposed in the openings of the end portions of the predetermined cells 2 on the inflow end face 11 side and the openings of the end portions of the remaining cells 2 on the outflow end face 12 side, respectively. The compartment 2 in which the hole sealing portion 5 is disposed in the opening portion on the outflow end face 12 side and the inflow end face 11 side is opened is referred to as an inflow compartment 2a. The compartment 2 in which the hole sealing portion 5 is disposed in the opening portion on the inflow end face 11 side and the outflow end face 12 side is opened is referred to as an outflow compartment 2b. The inflow cells 2a and the outflow cells 2b are preferably alternately arranged with the partition wall 1 interposed therebetween. It is preferable that both end surfaces of the honeycomb filter 100 are formed in a checkered pattern by the hole sealing portions 5 and the "openings of the cells 2".
The honeycomb filter 100 of the present embodiment has main characteristics particularly in terms of the structure of the porous partition walls 1 constituting the honeycomb structure 4. Hereinafter, the structure of the porous partition walls 1 constituting the honeycomb structure 4 will be described.
First, the partition wall 1 is made of a material containing cordierite as a main component. That is, the partition walls 1 are porous bodies made of a material containing cordierite as a main component. Here, "principal component" means: the content of the components is 90% by mass or more. The content of cordierite in the material constituting the partition wall 1 is preferably 92 mass% or more, more preferably 94 mass% or more. In addition, the partition wall 1 particularly preferably contains only cordierite in addition to the components inevitably contained.
In the honeycomb filter 100, the porosity of the partition walls 1 is 60 to 70%. The porosity of the partition wall 1 is a value measured by mercury porosimetry. For example, the porosity of the partition wall 1 can be measured by using Autopore 9500 (trade name) manufactured by Micromeritics corporation. A part of the partition wall 1 may be cut out from the honeycomb structure 4 to prepare a sample sheet, and the porosity of the partition wall 1 may be measured using the sample sheet thus obtained. The porosity of the partition walls 1 is preferably a constant value throughout the entire area of the honeycomb structure 4. If the porosity of the partition wall 1 is less than 60% or more than 70%, the rise in pressure loss becomes large when the catalyst for purifying exhaust gas is supported by the partition wall 1. The porosity of the partition wall 1 is preferably 65 to 70%, more preferably 67 to 70%.
In the honeycomb filter 100, the ratio (S2/s1×100%) of the sum S2 of the opening areas of the pores having an equivalent circle diameter exceeding 3 μm in the unit surface area S1 of the partition walls 1 to the unit surface area S1 is 58 to 70%. By configuring in this way, when the exhaust gas purifying catalyst is supported, the trapping efficiency can be improved and the increase in pressure loss can be suppressed.
The sum S2 of the opening areas of the pores having an equivalent circle diameter exceeding 3 μm present in the unit surface area S1 of the partition wall 1 can be measured by the following method. First, a sample for measurement is cut out from the honeycomb structure 4 so that the surfaces of the partition walls 1 of the honeycomb structure 4 can be observed. Then, the surface of the partition wall 1 of the sample for measurement was photographed by a laser microscope. For example, a shape analysis laser microscope "VK X250/260 (trade name)" manufactured by Keyence corporation may be used as the laser microscope. In the imaging of the surface of the partition wall 1, the magnification was 480 times, and any part of 10 fields of view was imaged. Image processing is performed on the captured image to determine the opening area S of each pore on the surface of the partition wall 1 x (μm 2 ) Equivalent circle diameter (μm). In the image processing, the area is selected so as not to include the partition wall 1 other than the surface of the partition wall 1 in the area where the image processing is performed, and the inclination of the surface of the partition wall 1 is corrected to be horizontal. Then, the upper limit of the height of the pores was changed to-3.0 μm from the reference surface. The opening area A of each pore of the captured image is calculated by image processing software under the condition that pores with equivalent circle diameters of 3 μm or less are ignored x (μm 2 ) Equivalent circle diameter R x (μm). The opening area A of each pore can be measured x (μm 2 ) For the measured opening area A x (μm 2 ) In equivalent circle diameter R x (μm) = v {4× (opening area a) x (μm 2 ) The equivalent circle diameter R of the pores on the surface of the partition wall 1 is calculated by)/pi x (μm). Further, the ratio (S2/S1X 100%) of the sum S2 of the opening areas of the pores having an equivalent circle diameter exceeding 3 μm in the unit surface area S1 of the partition wall 1 to the unit surface area S1 was calculated. Hereinafter, the above ratio may be referred to as "ratio (%) of the total opening area of pores having an equivalent circle diameter exceeding 3 μm". Can be measured as "opening area A" by the above-mentioned method x (μm 2 ) The form of the sum of "per unit surface area S1" is used to determine "unit tableThe sum of the opening areas S2 of pores having an equivalent circle diameter exceeding 3 μm present in the area S1. The "unit surface area S1" may be any size, and for example, may be 1mm as the "unit surface area S1 2 . The ratio (%) of the total opening area of pores having an equivalent circle diameter exceeding 3 μm is set as an average value of measurement results of 10 fields of view (i.e., the ratio (%) of the total opening area of pores having an equivalent circle diameter exceeding 3 μm for each of the photographed images of 10 fields of view). As the image processing software, for example, "VK-X (trade name)" attached to a shape analysis laser microscope "VK X250/260 (trade name)" manufactured by Keyence corporation may be used. The image processing software described above can be used to perform: measurement of equivalent circle diameter of each pore, and image analysis of pores of a predetermined equivalent circle diameter were ignored.
The proportion (%) of the total opening area of pores having an equivalent circle diameter exceeding 3 μm present on the surface of the partition wall 1 may be 58 to 70%, for example, preferably 60 to 70%, and more preferably 65 to 70%.
In the honeycomb filter 100, the ratio (R/D) of the average opening equivalent circle diameter R (μm) of the pores having an equivalent circle diameter exceeding 3 μm present on the surface of the partition wall 1 measured by mercury intrusion method to the average pore diameter D (μm) of the partition wall 1 is 0.3 to 0.8. By configuring in this way, when the exhaust gas purifying catalyst is supported, the trapping efficiency can be improved and the increase in pressure loss can be suppressed. Hereinafter, the average opening equivalent circle diameter R (μm) of the pores present on the surface of the partition wall 1 may be simply referred to as "average opening equivalent circle diameter R (μm)" of the pores on the surface of the partition wall 1 "or" average opening diameter R (μm) of the pores on the surface of the partition wall 1 ".
The average opening equivalent circle diameter R (μm) of the pores on the surface of the partition wall 1 can be calculated from the result of image analysis when the ratio (%) of the total opening area of the pores having the equivalent circle diameter exceeding 3 μm is calculated. That is, the opening area A of each pore can be measured by image analysis x (μm 2 ) Using the above calculation formula, the equivalent circle diameter R of each pore is calculated x (μm). Average opening of pores on the surface of partition wall 1The value of the equivalent circle diameter R (μm) was set as the measurement result of 10 fields of view (i.e., the equivalent circle diameter R of each of the photographed images of 10 fields of view) x (μm)). Although not particularly limited, the average opening equivalent circle diameter R (μm) of the pores on the surface of the partition wall 1 is preferably 5 to 12 μm.
On the other hand, the average pore diameter D (μm) of the partition walls 1 is a value measured by mercury porosimetry. For example, the average pore diameter D (μm) of the partition wall 1 can be measured by using Autopore 9500 (trade name) manufactured by Micromeritics. The average pore diameter D (μm) can be measured using the above-described test piece for measuring the porosity. Although not particularly limited, the average pore diameter D (μm) of the partition wall 1 is preferably 9 to 15 μm. The average pore diameter D (μm) of the partition walls 1 is: is defined as the value calculated by providing a pore diameter of half the volume of the total pore volume by mercury intrusion.
The ratio (R/D) of the average opening equivalent circle diameter R (μm) of the pores on the surface of the partition wall 1 to the average pore diameter D (μm) of the partition wall 1 may be 0.3 to 0.8, for example, preferably 0.3 to 0.7, and more preferably 0.3 to 0.5.
In the honeycomb filter 100, the ratio (S3/s2×100%) of the sum S3 of the opening areas of the pores having an equivalent circle diameter of 40 μm or more in the unit surface area S1 of the partition walls 1 to the sum S2 of the opening areas of the pores having an equivalent circle diameter exceeding 3 μm in the unit surface area S1 is preferably 3 to 5%. By configuring in this manner, the collection efficiency of the honeycomb filter 100 can be further improved. The sum S3 of the opening areas of the pores having an equivalent circle diameter of 40 μm or more can be obtained from the result of image analysis when the ratio (%) of the total opening area of the pores having an equivalent circle diameter of more than 3 μm is calculated. That is, the equivalent circle diameter R of each pore on the surface of the partition wall 1 is obtained x After (μm), only the equivalent circle diameter R x Opening area A of pores having a diameter of 40 μm or more x (μm 2 ) The sum of (2) is: the sum S3 of opening areas of pores having an equivalent circle diameter of 40 μm or more. Hereinafter, the ratio of the sum S3 of the opening areas of the pores having an equivalent circle diameter of 40 μm or more may be referred to as "equivalent circle diameter of 40The ratio (%) of the total opening area of the pores having a diameter of μm or more.
In the honeycomb filter 100, the pore depth of the pores at the surface of the partition walls 1 as determined by a laser microscope is preferably 1.0 to 3.0 μm. By configuring in this way, the catalyst is easily applied to the partition walls 1, and the collection efficiency of the honeycomb filter 100 after the catalyst application can be further improved. The pore depth of the pores at the surface of the partition wall 1 indicates: the surface of the partition wall 1 formed of a porous body has a depth of pores which are open. Hereinafter, the "pore depth of the pores at the surface of the partition wall 1" may be referred to as "pore depth of the surface of the partition wall 1".
The pore depth of the pores at the surface of the partition wall 1 can be measured by the following method. First, a part of the partition wall 1 is cut out from the honeycomb filter 100 to prepare a measurement sample, and the surface roughness of the partition wall 1 of the measurement sample is photographed by a laser microscope. As the laser microscope, a shape analysis laser microscope "VK-X250/260 (trade name)", manufactured by Keyence corporation, may be used. The magnification at the time of measurement was set to 240 times. The image obtained by photographing was subjected to image processing using the multi-file parsing application VK-H1XM, excluding the region specific to the light amount. Further, surface shape correction is performed on the image. A reference surface is set so as to be-3 μm from the surface of the partition wall, and the pore depth of pores having a pore diameter of 3.8 μm or more from the reference surface is measured. The number average value of the measured values was defined as the pore depth (μm) of the surface of the partition wall 1.
The thickness of the partition wall 1 is not particularly limited, and for example, the thickness of the partition wall 1 is preferably 190.5 to 254 μm, more preferably 215.9 to 241.3 μm. For example, the thickness of the partition wall 1 may be measured using a scanning electron microscope or a microscope (microscope). If the thickness of the partition wall 1 is less than 190.5 μm, sufficient strength may not be obtained. On the other hand, if the thickness of the partition wall 1 exceeds 254 μm, the pressure loss of the honeycomb filter 100 sometimes increases.
The shape of the compartment 2 partitioned by the partition wall 1 is not particularly limited. For example, examples of the shape of the cell 2 in a cross section orthogonal to the direction in which the cell 2 extends include: polygonal, circular, oval, etc. As the polygon, there may be mentioned: triangle, quadrilateral, pentagon, hexagon, octagon, etc. The shape of the cells 2 is preferably triangle, quadrangle, pentagon, hexagon, octagon. In addition, regarding the shape of the cells 2, the shape of all the cells 2 may be the same shape or may be different shapes. For example, although not shown, quadrangular cells and octagonal cells may be mixed. In addition, regarding the size of the compartments 2, the sizes of all the compartments 2 may be the same or different. For example, although not shown, among the plurality of compartments, a part of the compartments may be made larger in size and the other compartments may be made relatively smaller in size. In the present utility model, the compartment means: a space surrounded by the partition wall.
The cell density of the honeycomb structure 4 is not particularly limited, and for example, the cell density of the honeycomb structure 4 is preferably 43.4 to 49.6 cells/cm 2 More preferably 45.0 to 48.1 pieces/cm 2 . By configuring in this manner, the pressure loss can be suppressed from increasing while maintaining the trapping performance of the honeycomb filter 100.
The shape of the honeycomb structural body 4 is not particularly limited. The shape of the honeycomb structure 4 may be: the inflow end face 11 and the outflow end face 12 have a columnar shape such as a circle, an ellipse, or a polygon.
The size of the honeycomb structure 4, for example, the length from the inflow end face 11 to the outflow end face 12, and the size of the cross section of the honeycomb structure 4 orthogonal to the direction in which the cells 2 extend are not particularly limited. When the honeycomb filter 100 is used as a filter for purifying exhaust gas, the respective sizes may be appropriately selected so as to obtain the optimum purification performance.
The material of the plugging portion 5 is not particularly limited. For example, the material may be the same as that of the partition wall 1 described above, or may be a material different from that of the partition wall 1.
The honeycomb filter 100 preferably has a catalyst for purifying exhaust gas supported on partition walls 1 partitioning a plurality of cells 2. The supporting of the catalyst on the partition wall 1 means: catalyst is applied to the surfaces of the partition walls 1 and to the inner walls of the pores formed in the partition walls 1. By configuring in this manner, CO, NOx, HC and the like in the exhaust gas can be rendered harmless by the catalytic reaction. In addition, oxidation of PM such as trapped soot can be promoted.
The catalyst supported on the partition wall 1 is not particularly limited. For example, as such a catalyst, a catalyst containing a platinum group element and an oxide containing at least one element selected from aluminum, zirconium and cerium is exemplified. The catalyst loading is preferably 50 to 100g/L. The catalyst loading (g/L) in the present specification indicates the amount (g) of catalyst loaded per unit volume (L) of the honeycomb filter 100.
(2) The manufacturing method of the honeycomb filter comprises the following steps:
the method for producing the honeycomb filter of the present utility model is not particularly limited, and the following methods are exemplified. First, a plastic blank for manufacturing a honeycomb structure is prepared. The green body for producing the honeycomb structure can be prepared by appropriately adding an additive such as a binder, a pore-forming material, and water to a material selected from the preferable materials of the partition walls as a raw material powder. In the production of the honeycomb filter of the present utility model, kaolin, talc, alumina, aluminum hydroxide, silica, and the like may be used as raw material powders for producing a green body, and these raw material powders may be prepared so as to be: a chemical composition of silica in the range of 42 to 56 mass%, alumina in the range of 30 to 45 mass% and magnesia in the range of 12 to 16 mass%. The pore-forming material may be a spherical material having an average particle diameter of 10 to 25. Mu.m, and the kaolin, alumina, or aluminum hydroxide may be a material having an average particle diameter of 7 μm or less.
Next, the thus obtained preform was extrusion molded, thereby producing: a honeycomb formed body having a columnar shape and having partition walls partitioning a plurality of cells and disposed so as to surround the peripheral walls of the partition walls. In extrusion molding, as a die for extrusion molding, there may be used: the extrusion face of the preform is provided with a die which is a slit of a reverse shape of the honeycomb formed body to be formed.
The obtained honeycomb formed body is dried by, for example, microwaves and hot air, and the openings of the cells are sealed by the same material as that used for the honeycomb formed body, thereby producing sealed portions. After the plugging portion is produced, the honeycomb formed body may be further dried.
Next, the honeycomb formed body having the plugged portions formed therein was fired to produce a honeycomb filter. The firing temperature and firing atmosphere vary depending on the raw materials, and if one skilled in the art would choose: the firing temperature and firing atmosphere are optimal for the selected material.
Examples
Hereinafter, the present utility model will be described in further detail with reference to examples, but the present utility model is not limited to these examples.
Example 1
As cordierite raw material powders, kaolin, talc, alumina, aluminum hydroxide, and silica were used, and these were mixed to prepare cordierite raw materials. Then, a pore-forming material, a dispersion medium, and an organic binder were added to the prepared cordierite raw material, and the resultant mixture was mixed and kneaded to prepare a green body. The pore-forming material was a spherical material having an average particle diameter of 20. Mu.m, the talc was a material having an average particle diameter of 7. Mu.m, the kaolin was a material having an average particle diameter of 4. Mu.m, the alumina was a material having an average particle diameter of 5. Mu.m, and the aluminum hydroxide was a material having an average particle diameter of 4. Mu.m.
Next, the obtained preform was molded by an extrusion molding machine to produce a honeycomb molded body. Then, the obtained honeycomb formed body was subjected to high-frequency dielectric heating and drying, and then further dried by a hot air dryer. The cells in the honeycomb formed body are quadrangular in shape.
Next, a plugged portion was formed in the dried honeycomb formed body. First, a mask is applied to the inflow end face of the honeycomb formed body. Next, the end to which the mask is applied (end on the inflow end face side) is immersed in the plugging slurry, and the opening of the compartment to which the mask is not applied (outflow compartment) is filled with the plugging slurry. In this way, the plugging portion is formed on the inflow end face side of the honeycomb formed body. In addition, the plugged portions are formed in the same manner in the inflow cells also in the outflow end face of the dried honeycomb formed body.
Next, the honeycomb formed body having the plugged portions formed therein was dried by a microwave dryer, and then completely dried by a hot air dryer, and both end faces of the honeycomb formed body were cut and adjusted to a predetermined size. Next, the dried honeycomb formed body was degreased and fired to produce a honeycomb filter of example 1.
In the honeycomb filter of example 1, the end face had a diameter of 132mm and the cell length in the extending direction was 110mm. In addition, the thickness of the partition wall was 215.9. Mu.m, and the cell density was 46 cells/cm 2 . The values of the thicknesses of the partition walls are shown in table 1.
In the honeycomb filter of example 1, the following procedure was used: measurement of "porosity (%)" and "average pore diameter D (μm)" of partition walls. Further, by the method described above, the following was obtained: "ratio (%) of the total opening area of pores having an equivalent circle diameter exceeding 3 μm", "average opening equivalent circle diameter R (μm)" of pores of the partition wall surface "," ratio (R/D) of average opening equivalent circle diameter R (μm) to average pore diameter D (μm) ", and" ratio (%) of the total opening area of pores having an equivalent circle diameter of 40 μm or more ". Further, by the method described above, the following was obtained: the "pore depth of the pores (μm)" at the surface of the partition wall. The results are shown in Table 1.
[ porosity (%) and average pore diameter D (μm) ]
The porosity (%) and the average pore diameter D (μm) of the partition walls were measured by using Autopore 9500 (trade name) manufactured by Micromeritics Co. In the measurement of the porosity (%) and the average pore diameter D (μm), a part of the partition wall was cut out from the honeycomb filter to prepare a test piece, and the measurement was performed using the obtained test piece. The test piece was a rectangular parallelepiped having a length of about 10mm, and about 20mm in each of the longitudinal, transverse, and height directions. The sampling position of the test piece was set near the center of the honeycomb structure in the axial direction.
TABLE 1
The honeycomb filter of example 1 was evaluated for trapping efficiency and pressure loss by the following method. In each evaluation of the trapping efficiency and the pressure loss, the platinum group element-containing catalyst was supported by the following method for each honeycomb filter to be evaluated, and the catalyst was measured after the catalyst was supported. The results are shown in Table 2.
(method of supporting catalyst)
First, a catalyst slurry containing alumina having an average particle diameter of 30 μm was prepared. Further, the catalyst is supported on the honeycomb filter using the prepared catalyst slurry. Specifically, the catalyst is carried by impregnating (dispersing) the honeycomb filter, and thereafter, excess catalyst slurry is blown off with air, whereby a predetermined amount of catalyst is carried on the partition walls of the honeycomb filter. Thereafter, the catalyst-supporting honeycomb filter was dried at a temperature of 100 ℃, and further, heat treatment was performed at 500 ℃ for 2 hours, thereby obtaining a catalyst-attached honeycomb filter. The catalyst loading on the honeycomb filter of example 1 was 75g/L.
(trapping efficiency)
First, the method comprises the following steps: the honeycomb filters attached with the catalyst of each of the examples and comparative examples were used as exhaust gas purifying filters. Next, the produced exhaust gas purification device was connected to the outlet side of an engine exhaust manifold of a 1.2L direct injection gasoline engine vehicle, and the number of soot contained in the gas discharged from the outlet of the exhaust gas purification device was measured by a PN measurement method. Regarding the running mode, implementation: the worst case driving mode of RDE driving was simulated (RTS 95). The accumulation of the number of soot discharged after the mode running is set as the number of soot in the exhaust gas purification device to be determined, and the collection efficiency (%) is calculated from the number of soot. Then, the following was found: the value (%) of the trapping efficiency of the exhaust gas purifying device using the catalyst-attached honeycomb filter of each of the examples and comparative examples is as follows: the value of the trapping efficiency of the exhaust gas purifying apparatus using the catalyst-attached honeycomb filter of comparative example 1 was set to 100%. In the collection efficiency evaluation, the honeycomb filters of each example and comparative example were evaluated based on the following evaluation criteria.
Evaluation of "you": when the value of the trapping efficiency ratio (%) exceeds 120%, the evaluation was set to "excellent".
Evaluation of "good": when the value of the collection efficiency ratio (%) exceeds 110% and is 120% or less, the evaluation is regarded as "good".
Evaluation "cocoa": when the value of the collection efficiency ratio (%) exceeds 100% and is 110% or less, the evaluation is "ok".
Evaluation of "difference": when the value of the collection efficiency ratio (%) is 100% or less, the evaluation is set to "poor".
(pressure loss)
Exhaust gas discharged from a 1.2L direct injection gasoline engine is heated at 700 ℃ for 600m 3 The flow rate of/h was measured on the inflow end face side and the outflow end face side of the catalyst-attached honeycomb filter. Then, the pressure difference between the inflow end face side and the outflow end face side was calculated, and the pressure loss (kPa) of the honeycomb filter was obtained. Then, the following was found: the values (%) of the pressure loss of the catalyst-attached honeycomb filters of the examples and comparative examples below were: the value of the pressure loss of the catalyst-attached honeycomb filter of comparative example 1 was set to 100%. In the pressure loss evaluation, the honeycomb filters of the respective examples were evaluated based on the following evaluation criteria.
Evaluation of "you": when the value of the pressure loss ratio (%) was 90% or less, the evaluation was "excellent".
Evaluation of "good": when the value of the pressure loss ratio (%) exceeds 90% and is 95% or less, the evaluation is regarded as "good".
Evaluation "cocoa": when the value of the pressure loss ratio (%) exceeds 95% and is 100% or less, the evaluation is "ok".
Evaluation of "difference": when the value of the pressure loss ratio (%) exceeds 100%, the evaluation thereof is set to "poor".
Examples 2 to 7
In examples 2 to 7, the structure of the honeycomb structure was changed as shown in table 1. In examples 2 to 7, the average particle size of the pore-forming material and the average particle sizes of kaolin, alumina, and aluminum hydroxide were adjusted as in the characteristics of examples 2 to 7, to produce honeycomb structures.
Comparative examples 1 to 6
In comparative examples 1 to 6, the structure of the honeycomb structure was changed as shown in table 1. In comparative examples 1 to 6, a crushed pore-forming material, and kaolin, alumina, and aluminum hydroxide having an average particle diameter of more than 7 μm were used.
The honeycomb filters of examples 2 to 7 and comparative examples 1 to 6 were evaluated for trapping efficiency and pressure loss by the same method as in example 1. The results are shown in Table 2. The honeycomb filter of comparative example 1 was set as an evaluation criterion in each evaluation.
TABLE 2
(results)
The honeycomb filters of examples 1 to 7 showed that, in the evaluation of the trapping efficiency and the pressure loss: more excellent results than the honeycomb filter of comparative example 1 as the evaluation reference. In particular, in the honeycomb filter of example 2, the porosity (%) of the partition walls was 69%, the pore depth of the micropores was 3 μm, and the result of evaluation of the pressure loss was particularly excellent. In the honeycomb filter of example 3, the average opening equivalent circle diameter was 5 μm, the proportion of pores having an equivalent circle diameter of 40 μm or more was 5%, and the result of the evaluation of the collection efficiency was particularly excellent.
On the other hand, in the honeycomb filter of comparative example 2, the ratio (%) of the total opening area of the pores having an equivalent circle diameter exceeding 3 μm was 71%, and the ratio (R/D) of the average opening equivalent circle diameter R (μm) to the average pore diameter D (μm) was 0.9, and the evaluation result (judgment) of the collection efficiency was poor.
In the honeycomb filter of comparative example 3, the ratio (%) of the total opening area of the pores having an equivalent circle diameter exceeding 3 μm was 57%, and the evaluation result (judgment) of the pressure loss was poor.
In the honeycomb filter of comparative example 4, the porosity (%) of the partition walls was 71%, the ratio (R/D) of the average opening equivalent circle diameter R (μm) to the average pore diameter D (μm) was 0.9, and the evaluation result (judgment) of the pressure loss was poor.
In the honeycomb filter of comparative example 5, the porosity (%) of the partition walls was 59%, and the evaluation result (determination) of the pressure loss was poor.
In the honeycomb filter of comparative example 6, the ratio (R/D) of the average opening equivalent circle diameter R (μm) to the average pore diameter D (μm) was 1.9, and the evaluation result (judgment) of the pressure loss was poor.
Industrial applicability
The honeycomb filter of the present utility model can be used as a filter for trapping particulate matter in exhaust gas.
Claims (4)
1. A honeycomb filter, comprising:
a columnar honeycomb structure having porous partition walls arranged to surround a plurality of cells, the plurality of cells forming fluid flow paths extending from an inflow end face to an outflow end face; and
a porous sealing portion disposed at either one of an end portion on the inflow end face side and an end portion on the outflow end face side of the cell,
the porosity of the partition wall is 60-70%,
the ratio (S2/S1.times.100%) of the sum S2 of the opening areas of pores having equivalent circle diameters exceeding 3 μm in the unit surface area S1 of the partition walls to the unit surface area S1 is 58 to 70%,
the ratio (R/D) of the average opening equivalent circle diameter R of the pores having an equivalent circle diameter exceeding 3 μm present at the surface of the partition wall measured by mercury intrusion method to the average pore diameter D of the partition wall is 0.3 to 0.8, wherein the average opening equivalent circle diameter R and the average pore diameter D are in μm.
2. The honeycomb filter of claim 1 wherein the filter is configured to filter the liquid,
the ratio (S3/S2X 100%) of the sum S3 of the opening areas of pores having an equivalent circle diameter of 40 μm or more in the unit surface area S1 to the sum S2 of the opening areas of pores having an equivalent circle diameter exceeding 3 μm in the unit surface area S1 is 3 to 5%.
3. The honeycomb filter according to claim 1 or 2, wherein,
the pore depth of the pores at the surface of the partition wall as determined by a laser microscope is 1.0 to 3.0 μm.
4. The honeycomb filter according to claim 1 or 2, wherein,
the thickness of the partition wall is 190.5-254 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320909971.2U CN220609582U (en) | 2023-04-21 | 2023-04-21 | Honeycomb filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320909971.2U CN220609582U (en) | 2023-04-21 | 2023-04-21 | Honeycomb filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220609582U true CN220609582U (en) | 2024-03-19 |
Family
ID=90213096
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320909971.2U Active CN220609582U (en) | 2023-04-21 | 2023-04-21 | Honeycomb filter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220609582U (en) |
-
2023
- 2023-04-21 CN CN202320909971.2U patent/CN220609582U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2019171318A (en) | Honeycomb filter | |
| JP7097210B2 (en) | Honeycomb filter | |
| JP2019150737A (en) | Honeycomb structure | |
| US11085342B2 (en) | Honeycomb filter | |
| US20230311048A1 (en) | Honeycomb filter | |
| CN219333795U (en) | Honeycomb filter | |
| CN220609582U (en) | Honeycomb filter | |
| CN113332811B (en) | Honeycomb filter | |
| US20210270162A1 (en) | Honeycomb filter | |
| CN113332809B (en) | Honeycomb filter | |
| CN113332812B (en) | Honeycomb filter | |
| CN113413704B (en) | Honeycomb filter | |
| CN113332808B (en) | Honeycomb filter | |
| CN218934533U (en) | Honeycomb filter | |
| US11571688B2 (en) | Honeycomb filter | |
| CN220609583U (en) | Honeycomb filter | |
| CN219672708U (en) | Honeycomb filter | |
| CN218816601U (en) | Honeycomb filter | |
| CN219159046U (en) | Honeycomb filter | |
| US20230405505A1 (en) | Honeycomb filter | |
| CN118718583A (en) | Honeycomb filter | |
| JP2022152976A (en) | honeycomb filter | |
| CN118356731A (en) | Honeycomb filter | |
| CN118361303A (en) | Honeycomb filter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |