Ceramic honeycomb filter and its structure
AssigneeHitachi Metals, Ltd.
InventorsHirohisa Suwabe, Shunji Okazaki, Osamu Tokudome, Yasuhiko Otsubo
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Abstract
A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, wherein one end of each flow path is provided with a sealer, such that sealers of the flow paths in an inlet and an outlet of the ceramic honeycomb structure in a desired pattern; wherein the partition walls have thickness of 0.1-0.5 mm and a porosity of 50-80%; wherein the porosity of the sealers is larger than that of partition walls; and wherein the depth of the sealers is 3-15 mm.
Claims20
A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through said porous partition walls to remove particulates from said exhaust gas, wherein one end of each flow path is provided with a sealer, such that scalers of said flow paths are in an inlet and an outlet of said ceramic honeycomb structure in a desired pattern;
- wherein said partition walls have a thickness of 0.1-0.5 mm and a porosity of 50-80%;
- wherein the porosity of said sealers is larger than that of the partition walls;
- wherein the depth of said scalers is 3-15 mm, and
- wherein at least part of pores having cross section areas of 1,000 μm2 or more in an arbitrary cross section of said partition walls have circular cross sections.
A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through said porous partition walls to remove particulates from said exhaust gas, wherein one end of each flow path is provided with a sealer, such that scalers of said flow paths in an inlet and an outlet of said ceramic honeycomb structure are in a desired pattern, wherein said sealers have pores;
- and wherein at least part of said pores have substantially circular cross sections.
A ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, wherein an arbitrary cross section of said partition walls forming said flow paths have nonuniform thickness,
- wherein the average thickness Tav, the maximum thickness Tmax and the minimum thickness Tmin of said partition walls satisfy the conditions of Tav/(Tmax−Tmin)≦40, and
- wherein a transverse cross section of each flow path is in a substantially square shape as a whole;
- wherein at least part of the transverse cross sections of flow paths is arcuate in one pair of opposing corners;
- and wherein said one pair of opposing corners is larger than the other pair of opposing corners in a radius of curvature in each flow path.
A ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, wherein a transverse cross section of each flow path is in a substantially square shape as a whole;
- wherein at least part of cross sections perpendicular to axial direction of flow paths is arcuate in one pair of opposing corners;
- and wherein said one pair of opposing corners is larger than the other pair of opposing corners in a radius of curvature in each flow path.
A ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, wherein an arbitrary cross section of said partition walls forming said flow paths have nonuniform thickness, wherein it has a porosity of 50-80%;
- and wherein at least part of pores having cross section areas of 1,000 μm2 or more in an arbitrary cross section of said partition walls have circular cross sections.
Dependencies are inferred from the claim text.