CN-121988107-A - Honeycomb filter

CN121988107ACN 121988107 ACN121988107 ACN 121988107ACN-121988107-A

Abstract

The invention provides a honeycomb filter which can restrain the rising of pressure loss and realize excellent purification performance. The honeycomb filter comprises a columnar honeycomb structure (4) having porous partition walls (1) arranged so as to surround a plurality of cells (2), and a hole sealing portion (5) wherein the cross-sectional shape of an inflow cell (2 a) is octagonal, the cross-sectional shape of an outflow cell (2 b) is quadrangular, the area ratio S1/S2 of the cross-sectional area S2 of the outflow cell (2 b) to the cross-sectional area S1 of the inflow cell (2 a) is 1.40-2.20, the central portion (15) in the cross-section of the honeycomb structure (4) orthogonal to the cell extending direction is composed of a cell straight region (15A) in which the cells extend in a straight line, the outer peripheral portion (16) in the cross-section is composed of a cell bending region (16A) in which the cells extend so as to bend toward the outer peripheral side, and the percentage h/Lx 100% of the ratio of the bending height h of the cell bending region (16A) to the total length L of the honeycomb structure (4) is 1.00-3.00%.

Inventors

Nakagoshi Yuta
YOSHIOKA FUMIHIKO
KATO KYOHEI
KASUGA

Assignees

日本碍子株式会社

Dates

Publication Date: 20260508
Application Date: 20250928
Priority Date: 20241101

Claims (3)

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 flow paths for a fluid extending from an inflow end face to an outflow end face, and A hole sealing portion disposed to seal an end portion of either one of the inflow end face side and the outflow end face side of the compartment, The compartment in which the hole sealing portion is disposed at the end portion on the outflow end face side and in which the inflow end face side is opened is defined as an inflow compartment, The compartment in which the hole sealing portion is disposed at the end portion on the inflow end face side and in which the outflow end face side is opened is referred to as an outflow compartment, In a cross section of the honeycomb structural portion orthogonal to a direction in which the cells extend, the cross section of the inflow cells is octagonal, and the cross section of the outflow cells is quadrangular except for the cells arranged at the outermost periphery of the honeycomb structural portion, The area ratio S1/S2 of the cross-sectional area S2 of the quadrangular outflow compartment to the cross-sectional area S1 of the octagonal inflow compartment is 1.60 to 1.90, The central portion in a cross section of the honeycomb structural portion orthogonal to the direction in which the cells extend is constituted by a cell straight region in which the cells extend linearly from the inflow end face toward the outflow end face, and the outer peripheral portion in the cross section is constituted by a cell curved region extending in such a manner that the cells curve toward the outer peripheral side at a midway portion from the inflow end face toward the outflow end face, The length of the honeycomb structure from the inflow end face to the outflow end face is set to be the full length L, The distance from the boundary between the compartment straight region and the compartment curved region to the maximum point of the compartment curved region curved toward the outer peripheral side is defined as a curved height h, The percentage of the bending height h of the cell bending region relative to the total length L of the honeycomb structure, i.e., h/LX100%, is 1.00 to 3.00%.
2. The honeycomb filter of claim 1, The thickness of the partition wall is 0.17-0.36 mm.
3. A honeycomb filter according to claim 1 or 2, characterized in that, The cell density of the honeycomb structure part is 30/cm 2 -63/cm 2 .

Description

Honeycomb filter Technical Field The present invention relates to a honeycomb filter. More specifically, the present invention relates to a honeycomb filter which can effectively suppress an increase in pressure loss when particulate matter such as soot adheres to the surface of a partition wall and can realize excellent purification performance when an exhaust gas purification catalyst 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 the like, and a device for purifying toxic gas components such as CO, HC, NO x, etc., a honeycomb filter using a honeycomb structure has been known (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. 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". 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. If the PM in the exhaust gas is continuously removed by the honeycomb filter, PM such as soot accumulates in the honeycomb filter, the purification efficiency decreases, and the pressure loss of the honeycomb filter increases. For this reason, for example, in a purification apparatus using a honeycomb filter, "regeneration treatment" or the like is performed in which PM deposited inside the honeycomb filter is burned. Prior art literature Patent literature Patent document 1 International publication No. 2006/095835 Disclosure of Invention Problems to be solved by the invention A honeycomb filter for purifying exhaust gas discharged from an engine of an automobile or the like has a problem in that particulate matter such as soot adheres to the surfaces of partition walls, which results in a high pressure loss. Accordingly, it is desired to develop a honeycomb filter capable of suppressing the increase in pressure loss. For example, as one of measures for reducing the pressure loss, studies have been made on "thinning" in which the thickness of the partition walls of the honeycomb filter is thinned. However, if the thickness of the partition wall is made thin, there is a problem that the trapping performance of the honeycomb filter is lowered. Further, if the thickness of the partition wall is made thin, the heat capacity of the entire honeycomb filter is reduced, and there is a problem that the honeycomb filter is likely to be broken during the regeneration process as described above. On the other hand, if the thickness of the partition wall is increased, the pressure loss of the honeycomb filter increases, and the mass of the honeycomb filter increases, so that the catalytic performance (in other words, the purification performance) of the exhaust gas purification catalyst supported on the honeycomb filter is deteriorated. The present invention has been made in view of the problems of the prior art as described above. The invention provides a honeycomb filter which can effectively inhibit the rise of pressure loss when particulate matters such as coal ash adhere to the surfaces of partition walls and can realize excellent purification performance when an exhaust gas purification catalyst is loaded. Means for solving the problems According to the present invention, there is provided a honeycomb filter shown below. [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 flow paths for a fluid extending from an inflow end face to an outflow end face, and A hole sealing portion disposed to seal an end portion of either one of the inflow end face side and the outflow end face side of the compartment, The c