The present invention provides a honeycomb filter including a honeycomb fired body including porous cell partition walls, exhaust gas introduction cells each having an open end at an exhaust gas inlet side and a plugged end at an exhaust gas outlet side, exhaust gas emission cells each having an open end at the exhaust gas outlet side and a plugged end at the exhaust gas inlet side, and an outer wall on the periphery thereof. The cross-sectional shape of each exhaust gas introduction cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion, and the cross-sectional shape of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The cross-sectional shape of each exhaust gas introduction cell in a plane perpendicular to the longitudinal direction thereof is a polygon. The exhaust gas emission cells, except for the cells adjacent to the outer wall, are each adjacently surrounded fully by the exhaust gas introduction cells across the porous cell partition walls. The cells adjacent to the outer wall include the exhaust gas introduction cells and the exhaust gas emission cells. The aperture ratio of the exhaust gas introduction cells is higher than the aperture ratio of the exhaust gas emission cells, and the cross-sectional area of each exhaust gas emission cell is larger than the cross-sectional area of each exhaust gas introduction cell. Among the sides forming the polygon, the number of sides facing the exhaust gas introduction cells across the cell partition walls is larger than the number of sides facing the exhaust gas emission cells across the cell partition walls.

The present invention provides a honeycomb filter including a honeycomb fired body including porous cell partition walls, exhaust gas introduction cells each having an open end at an exhaust gas inlet side and a plugged end at an exhaust gas outlet side, exhaust gas emission cells each having an open end at the exhaust gas outlet side and a plugged end at the exhaust gas inlet side, and an outer wall on the periphery thereof. The cross-sectional shape of each exhaust gas introduction cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The cross-sectional shape of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The exhaust gas emission cells, except for the cells adjacent to the outer wall, are each adjacently surrounded fully by the exhaust gas introduction cells across the porous cell partition walls. The cells adjacent to the outer wall include the exhaust gas introduction cells and the exhaust gas emission cells. A substantial ratio of the number of the exhaust gas introduction cells to the number of the exhaust gas emission cells (exhaust gas introduction cells:exhaust gas emission cells) is 4:1. All the exhaust gas introduction cells, except for the cells adjacent to the outer wall, have the same cross-sectional area in a plane perpendicular to the longitudinal direction thereof, the cross-sectional area of each exhaust gas introduction cell being smaller than that of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof.

The present invention provides a honeycomb filter including a honeycomb fired body including porous cell partition walls, exhaust gas introduction cells each having an open end at an exhaust gas inlet side and a plugged end at an exhaust gas outlet side, exhaust gas emission cells each having an open end at the exhaust gas outlet side and a plugged end at the exhaust gas inlet side, and an outer wall on the periphery thereof. The cross-sectional shape of each exhaust gas introduction cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The cross-sectional shape of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The exhaust gas emission cells, except for the cells adjacent to the outer wall, are each adjacently surrounded fully by the exhaust gas introduction cells across the porous cell partition walls; the cross-sectional area of each exhaust gas emission cell is larger than the cross-sectional area of each exhaust gas introduction cell. Provided that the hydraulic diameter is given by the following equation (1) and the area based on the given hydraulic diameter is given by the following equation (2), the ratio of the area based on the hydraulic diameter of an exhaust gas introduction cell to the cross-sectional area of the exhaust gas introduction cell is 0.95 to 0.98, and the ratio of the area based on the hydraulic diameter of an exhaust gas emission cell to the cross-sectional area of the exhaust gas emission cell is 0.7 to 0.9:

Hydraulic diameter=(4cross-sectional area of cell)/Cross-sectional peripheral length of cell(1),

Area based on the hydraulic diameter=(Hydraulic diameter/2).sup.2(2).

A honeycomb filter includes a silicon carbide honeycomb fired body, an end face, and porous cell walls. The silicon carbide honeycomb fired body includes a plurality of cells through which exhaust gas is to flow and which include exhaust gas introduction cells and exhaust gas emission cells. The silicon carbide honeycomb fired body includes silicon carbide grains having a silicon-containing oxide layer with a thickness of 0.1 to 2 m on surfaces of the silicon carbide grains. The end face has an aperture ratio of not less than 20% at the exhaust gas emission side. The porous cell walls define rims of the plurality of cells. The plugged portions of the exhaust gas introduction cells are arranged in vertical and horizontal lines with the porous cell walls residing between the plugged portions in the end face at the exhaust gas emission side.

Provided is a honeycomb fired body in which the pressure loss in the initial state where PM has not accumulated is sufficiently low, the strength is sufficiently high, and the heat capacity is not small. The honeycomb fired body of the present invention is a honeycomb fired body including a plurality of cells in each of which one end is plugged and which serve as channels of exhaust gas, and porous cell partition walls that define the cells, wherein the honeycomb fired body is formed of SiC, the plurality of cells include peripheral cells located at an outermost peripheral region of the honeycomb fired body and inner cells located more inward than the peripheral cells, all the inner cells have the same cross-sectional shape that is a rectangle in a plane perpendicular to the longitudinal direction thereof, each peripheral cell is defined by the cell partition walls and an outer wall forming a periphery of the honeycomb fired body, the cell partition walls in contact with the outer wall each have a thick wall region where the wall thickness gradually increases toward the outer wall, the cross-sectional shape of the peripheral cells in a plane perpendicular to the longitudinal direction thereof is a shape formed by reducing the rectangular cross-sectional shape of the inner cells to obtain a reduced rectangle and chamfering or rounding two corners of the reduced rectangle, the cross-sectional area of each peripheral cell in a plane perpendicular to the longitudinal direction thereof is 60 to 80% of the cross-sectional area of each inner cell in a plane perpendicular to the longitudinal direction thereof, the cell partition walls include inter-peripheral-cell cell partition walls each located between the peripheral cells and inter-inner-cell cell partition walls each located between the inner cells, and the minimum thickness of the inter-peripheral-cell cell partition walls is greater than the thickness of the inter-inner-cell cell partition walls.

In one aspect, catalytic assemblies are described herein. A catalytic assembly, in some embodiments, comprises a plurality of honeycomb catalyst segments bonded to one another by a bonding material, the honeycomb catalyst segments comprising an outer peripheral wall and a plurality of inner partition walls defining flow channels extending longitudinally through the catalyst segments, wherein the outer peripheral wall and inner partition walls have dispersed throughout a chemical composition comprising 50-99.9 weight percent an inorganic oxide composition and at least 0.1 weight percent a catalytically active metal functional group.

A multi-segmented monolith (MSM) which can be used as a structured packing in mass-transfer and catalytic operations is disclosed. The MSM comprises a series of longitudinally attached segments. The length of each segment is between 0.2 to 5 inches. Each segment has flow passages which extend from the inlet flow face to the outlet flow face. The segments are located such that the outlet of a flow passage on a segment is in flow communication with the inlet of a flow passage on an adjacent attached segment. The segments are attached to each other either in the green state or with an adhesive, such as sodium silicate. Alternately, the segments are attached to each other by a mechanical means, such as a tie-rod or a dowel pin. The MSM further includes a spacer means between adjacent segments. A plurality of MSMs are further assembled into a Compound MSM (CMSM).

There is disclosed a grinding method of a honeycomb structure, wherein a grind processing member having an outer peripheral surface, a first grinding wheel tapered surface and a second grinding wheel tapered surface and rotating around a central axis grinds a joined honeycomb segment assembly rotating around a central axis, and the above respective surfaces of the grind processing member form a first ground region, a second ground region, a center ground surface, a first tapered surface and a second tapered surface, to prepare the honeycomb structure including a cylindrical honeycomb base material, and a ring-like bulge portion which surrounds an outer periphery of the honeycomb base material, protrudes from the outer periphery of the honeycomb base material toward the outside in a flange manner, and has the first tapered surface, the second tapered surface and the center ground surface.

A honeycomb filter includes a plurality of cells and porous cell walls. The plurality of cells include exhaust gas introduction cells and exhaust gas emission cells. The porous cell walls each have a porosity of 55% or acre but not more than 70%. The porous cell walls include pores with a pore diameter of 40 m or more. The pores have a pore volume occupying 10% or more of a total pore volume of the porous cell walls. The exhaust gas emission cells have 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. A total volume of the exhaust gas introduction cells is larger than a total volume of the exhaust gas emission cells.

A honeycomb filter includes a plurality of cells and porous cell walls. The plurality of cells include exhaust gas introduction cells and exhaust gas emission cells. Each of the exhaust gas emission cells is adjacently surrounded fully by the exhaust gas introduction cells across the porous cell walls. The exhaust gas introduction cells include first exhaust gas introduction cells and second exhaust gas introduction cells. Each of the first exhaust gas introduction cells has the cross sectional area equal to or smaller than 0.7 mm.sup.2 in the cross section perpendicular to the longitudinal direction of the plurality of cells.