A honeycomb structure includes a honeycomb body having a partition wall defining a plurality of cells that extend from an inflow-end face as one end face to an outflow-end face as the other end face, the honeycomb body having a circumferential shape at a cross section orthogonal to an extending direction of the cells that is a rectangular shape with four corners being chamfered and having a long diameter and a short diameter, wherein the plurality of cells are hexagon cells having a hexagonal shape at the cross section orthogonal to the extending direction of the cells, and the hexagon cells are configured so that a longest diagonal line of each hexagon cell and the short diameter S of the honeycomb body form an angle that is 0 to 6.

The invention relates to an exhaust gas purification system applied to an internal combustion engine. The engine has a turbocharger including a turbine wheel and a housing for housing the turbine wheel. The housing defines a turbine outlet passage communicating with an exhaust gas discharging part of the turbine wheel. The engine further has an exhaust passage part communicating with an exhaust gas outlet of the turbine outlet passage. The system comprises an exhaust gas purification apparatus disposed in the exhaust passage part at a position adjacent to the exhaust gas outlet of the turbine outlet passage. Further, the apparatus includes an exhaust gas purification member. The member is provided such that its density in a peripheral part of the exhaust passage part is larger than that in a central part of the exhaust passage part and a flow passage resistance per unit volume of the member at an area of the central part of the exhaust passage part is smaller than that at an area of the peripheral part of the exhaust passage part.

In the plugged honeycomb structure, 30% or more of first intersection portions in which a first partition wall intersects a second partition wall are first specific intersection portions in which a diameter of a maximum inscribed circle drawn in the first intersection portion is a specific size for a shortest distance between an inflow cell and an outflow cell, and 30% or more of non-first intersection portions other than the first intersection portions are non-first specific intersection portions in which a diameter of a maximum inscribed circle drawn in a non-first intersection portion is a specific size for a shortest distance between the inflow cells or the outflow cells.

Ho Honeycomb monolith structure, especially for use in mass transfer-limited processes or processes for the selective catalytic reduction (SCR) of nitrogen oxides, comprising: a plurality of cell walls defining a plurality of polygonal channels, the plurality of cell walls and channels extending in parallel along a common direction from an entrance end to an outlet end of the structure in the fluid flow direction. The transversal cross section of a polygonal channel has the shape of a convex elongated polygon, wherein at least 50% of the internal angles between two adjacent walls of the convex polygon are above 90 degrees and wherein the cell diameter ratio L.sub.L/L.sub.S is greater than 1.5.

An air filter, including: at least one wall-flow honeycomb particulate filter having at least one coat on at least a portion of the interior surface of the filter, wherein the at least one coat comprises at least one of: a sorbent; a catalyst; or a combination thereof, and the air filter, in-use, retains from filtered air at least one of: a particulate, a volatile organic compound, or a combination thereof. Also disclosed is an interior air purification system including the air filter, and methods of making and using the air filter.

Honeycomb monolith structure, especially for use as catalyst or support for a catalyst in selective catalytic reduction (SCR) of nitrogen oxides, comprising: a plurality of cell walls defining a plurality of polygonal channels, the plurality of cell walls and channels extending in parallel along a common direction from an entrance end to an outlet end of the structure in the fluid flow direction. The transversal cross section of a polygonal channel has the shape of a convex polygon in closest packing, wherein more than 50% of the internal angels between two adjacent walls of the convex polygon are above 90 degrees and wherein the cell aspect ratio L.sub.L/L.sub.S is greater than 1.5. The monolith structure has an outer row of polygons in shifted direction perpendicular to each other at the two side edges of the monolith which are parallel to the longest direction of the cells/channels.

A packing is provided which has an increased corrosion resistance, high chemical resistance, low flow resistance, and an increased service life in comparison with conventional packings, wherein, to this end, it is provided that the packing comprises includes a honeycomb body having first and second end faces, wherein the honeycomb body has a honeycomb structure which has a plurality of flow channels that are arranged substantially in parallel and that are adjacent to each other by means of channel walls, and wherein the honeycomb body is made from a first plastics material based on polytetrafluoroethylene (PTFE) polymer material. Furthermore, a column is proposed which comprises includes a housing that has at least one inlet, at least one outlet and one or more packings according to the invention which are preferably arranged in a flow path running from the inlet to the outlet, in succession if applicable.

A honeycomb filter includes a plugged honeycomb structure body which has cell rows arranged along one direction, in a cross section of the honeycomb structure body and including a first cell row constituted of at least one of an inflow cell and an outflow cell, and a through-cell, and a second cell row including no through-cells. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell row and a curvature radius R (m) of a curved shape of corner portions of a polygonal shape of each cell satisfy a relation of Equation (1) below: Equation (1): 0.4 (R/1000)/((P1+P2)/2) 100 20.

A honeycomb filter includes a plugged honeycomb structure body which has cell rows arranged along one direction in a cross section of the honeycomb structure body and including a first cell row constituted of inflow cells and a second cell row including outflow cells. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell row and a curvature radius R (m) of a curved shape of corner portions of a polygonal shape of each cell satisfy relations of Equations (1) and (2) below: Equation (1): 2100(P1/P2100)50, and Equation (2): 0.4(R/1000)/((P1+P2)/2)10020.

A honeycomb filter includes a plugged honeycomb structure body which has cell rows arranged along one direction in a cross section of the honeycomb structure body and including a first cell row constituted of at least one of an inflow cell and an outflow cell, and a through-cell, and a second cell row including no through-cells. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell and a curvature radius R of a curved shape of corner portions of a polygonal shape of each cell satisfy relations of Equations (1) and (2) below: Equation (1): 2100(P1/P2100)50, and Equation (2): 0.4(R/1000)/((P1+P2)/2)10020.