Patent ID: 9650928
Date: 2017-05-16
CPC Classifications: B01D,C04B,F01N,Y02T

Claim:
1. A honeycomb filter comprising: a plurality of cells through which exhaust gas is to flow and which include exhaust gas introduction cells and exhaust gas emission cells, the exhaust gas introduction cells each having an open end at an exhaust gas introduction side and a plugged end at an exhaust gas emission side, the exhaust gas emission cells each having an open end at the exhaust gas emission side and a plugged end at the exhaust gas introduction side; porous cell walls defining rims of the plurality of cells, the porous cell walls each having a porosity of 55% or more but not more than 70%, the porous cell walls including pores with a pore diameter of 40 μm or more which have a pore volume occupying 10% or more of a total pore volume of the porous cell walls, the porous cell walls being free from pores with a pore diameter of 10 μm or less or including pores with the pore diameter of 10 μm or less which have a pore volume occupying 10% or less of the total pore volume; the exhaust gas introduction cells and the exhaust gas emission cells each having a uniform cross sectional shape except for a plugged portion in a cross section perpendicular to a longitudinal direction of the plurality of cells thoroughly from the exhaust gas introduction side to the exhaust gas emission side; the exhaust gas emission cells having an average cross sectional area larger than an average cross sectional area of the exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells; and a total volume of the exhaust gas introduction cells being larger than a total volume of the exhaust gas emission cells, wherein each of the exhaust gas emission cells is adjacently surrounded fully by the exhaust gas introduction cells across the porous cell walls, wherein the exhaust gas introduction cells include first exhaust as introduction cells and second exhaust as introduction cells the second exhaust as introduction cells each having a cross sectional area larger than a cross sectional area of each of the first exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells, wherein each of the exhaust gas emission cells has a cross sectional area equal to or larger than the cross sectional area of each of the second exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells, and wherein, in the cross section perpendicular to the longitudinal direction of the plurality of cells, the exhaust gas introduction cells and the exhaust gas emission cells each have a polygonal shape, and wherein, in the cross section perpendicular to the longitudinal direction of the plurality of cells,