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CN-224221005-U - Honeycomb filter

CN224221005UCN 224221005 UCN224221005 UCN 224221005UCN-224221005-U

Abstract

The utility model provides a honeycomb filter which has excellent trapping performance. A honeycomb filter is characterized by comprising a columnar honeycomb structure portion having porous partition walls arranged so as to surround a plurality of cells, the plurality of cells being fluid passages extending from a first end surface to a second end surface, and a hole sealing portion arranged at an opening on the first end surface side or the second end surface side of each of the cells, wherein the pore diameter distribution of the partition walls obtained by structural analysis has a pore diameter D90 which is 90% of the total pore volume of the cumulative pore volume, and the average value of the equivalent circle diameters of the necks in which the flow passage area of the communication pores in the porous structure is the smallest is an average neck diameter, and the product of the D90 and the average neck diameter is 1.0X10- ‑10 m 2 to 9.0X10- ‑10 m 2 , wherein the unit of the pore diameter, the D90, the average value, and the average neck diameter is m.

Inventors

  • Sakai Wenxiang
  • Ito Hatsune

Assignees

  • 日本碍子株式会社

Dates

Publication Date
20260512
Application Date
20250306
Priority Date
20240329

Claims (6)

  1. 1. A honeycomb filter, comprising: A columnar honeycomb structure portion having porous partition walls arranged so as to surround a plurality of cells which form fluid flow paths extending from a first end surface to a second end surface, and A hole sealing portion disposed in an opening portion of each of the cells on the first end surface side or the second end surface side, In the pore diameter distribution of the partition walls obtained by structural analysis, the pore diameter in which the cumulative pore volume is 90% of the total pore volume is defined as D90, In the porous structure of the partition wall obtained by the structural analysis, the average value of equivalent circle diameters of necks in which the flow path area of the communicating pores in the porous structure is the smallest is defined as the average neck diameter, The product of the D90 and the average neck diameter is 1.0X10 -10 m 2 or more and 9.0X10 -10 m 2 or less, Wherein, the units of the pore diameter, the D90, the average value and the average neck diameter are m.
  2. 2. The honeycomb filter of claim 1, The D90 is 1.0X10 -5 m or more and 8.0X10 -5 m or less.
  3. 3. A honeycomb filter according to claim 1 or 2, characterized in that, The average neck diameter is 5.0X10 -6 m or more and 1.7X10 -5 m or less.
  4. 4. A honeycomb filter according to claim 1 or 2, characterized in that, In the pore diameter distribution of the partition walls obtained by the structural analysis, the pore diameter in which the cumulative pore volume is 10% of the total pore volume is defined as D10, The D10 is 5.0X10 -6 m or more and 2.5X10 -5 m or less, Wherein, the unit of D10 is m.
  5. 5. A honeycomb filter according to claim 1 or 2, characterized in that, In the pore diameter distribution of the partition walls obtained by the structural analysis, the pore diameter in which the cumulative pore volume is 50% of the total pore volume is set to D50, The D50 is 1.7X10 -5 m or more and 4.1X10 -5 m or less, Wherein the unit of D50 is m.
  6. 6. A honeycomb filter according to claim 1 or 2, characterized in that, The percentage of the porosity of the partition wall obtained by the structural analysis is 33% to 65%.

Description

Honeycomb filter Technical Field The present utility model relates to a honeycomb filter. More specifically, the present utility model relates to a honeycomb filter having excellent trapping performance. Background Conventionally, as a device for trapping particulate matter in exhaust gas discharged from an internal combustion engine such as an engine of an automobile, or for purifying a toxic gas component such as CO, HC, NOx, a honeycomb filter using a honeycomb structure has been known (see patent documents 1 to 5). The honeycomb structure has partition walls made of porous ceramics such as cordierite, and a plurality of cells are partitioned by the partition walls. The honeycomb filter is provided with hole sealing portions so as to alternately seal openings on the inflow end face side and openings on the outflow end face side of the plurality of cells with respect to the honeycomb structure. That is, the honeycomb filter has a structure in which inlet cells having inlet end face side openings and sealed at outlet end face sides and outlet cells having sealed at inlet end face sides and open at outlet end face sides are alternately arranged with partition walls interposed therebetween. In the honeycomb filter, porous partition walls function as a filter for trapping particulate matter in the exhaust gas. Hereinafter, particulate matter contained in the exhaust gas may be referred to as "PM". "PM" is an abbreviation for "particulate matter (particulate matter)". The purification of exhaust gas by the honeycomb filter is performed as follows. First, the honeycomb filter is arranged such that 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 inflow cells from the inflow end face side of the honeycomb filter. Then, 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. When passing through the porous partition walls, PM and the like in the exhaust gas are trapped and removed. Prior art literature Patent literature Patent document 1 Japanese patent No. 5507575 Patent document 2 Japanese patent No. 5469335 Patent document 3 Japanese patent No. 5518327 Patent document 4 Japanese patent No. 5372494 Patent document 5 Japanese patent No. 6004150 Disclosure of utility model Problems to be solved by the utility model A honeycomb filter for purifying exhaust gas discharged from an engine of an automobile employs a porous body having a high porosity and a high porosity as a porous partition wall. In recent years, further improvement in the trapping performance of the honeycomb filter has been demanded due to reinforcement of the exhaust gas restriction of automobiles and the like. Conventionally, in order to improve the trapping performance of a honeycomb filter, for example, the average pore diameter and pore diameter distribution of porous partition walls have been controlled. For example, as control of pore diameter distribution, there has been attempted to improve the collection performance of a honeycomb filter by adjusting the average pore diameter, or adjusting the value of pore diameter D90 in which the cumulative pore volume is 90% of the total pore volume. PM such as soot in the exhaust gas is trapped in pores of porous partition walls constituting the honeycomb filter, but particularly, neck portions having narrowed flow passage areas in the pores of the partition walls may affect trapping performance. Conventionally, the average pore diameter and pore diameter distribution of partition walls have been measured by a mercury-free method using a mercury porosimeter or the like. However, in the measurement by a conventional mercury porosimeter or the like, information on the diameter of the neck portion (hereinafter, also referred to as "neck diameter") in the air hole in the partition wall cannot be obtained. Therefore, it is not necessarily required to achieve sufficient improvement in the trapping performance by controlling only the parameters such as the average pore diameter and pore diameter distribution specified in the prior art, and it is desired to develop a new technique for improving the trapping performance of the honeycomb filter. The present utility model has been made in view of the problems of the prior art as described above. According to the present utility model, a honeycomb filter excellent in trapping performance is provided. Means for solving the problems According to the present utility model, there is provided a honeycomb filter shown below. [1] A honeycomb filter is characterized by comprising a columnar honeycomb structure portion having porous partition walls arranged so as to surround a plurality of cells, the plurality of cells being fluid passages extending from a first end surface to a second end surface, and a hole sealing portion arrange