Patent ID: 7658779

Claim:
A monolithic honeycomb element, comprising a plurality of adjacent ducts or channels, wherein: each of the plurality of adjacent ducts or channels is situated along an axis, the axes of the plurality of adjacent ducts or channels being substantially parallel; each of the plurality of adjacent ducts or channels is separated from adjacent ducts or channels by porous walls; each of the plurality of adjacent ducts or channels is stopped by a plug at one end; the plurality of adjacent ducts or channels comprises inlet ducts or channels being open at a gas intake face of the element, and outlet ducts or channels being open at a gas discharge face of the element, such that gas passing from the gas intake face of the element to the gas discharge face of the element passes through the porous walls; the plurality of adjacent ducts or channels comprises peripheral ducts or channels forming part of an outer wall of the element, the peripheral ducts or channels being configured to provide the element with an outer wall having an inner face that is substantially flat over an entire length of the element; the outer wall, when viewed in a cross-section substantially perpendicular to the axes of the plurality of adjacent ducts or channels, comprises at least one corner portion; the outer wall has a first cross-sectional thickness at the corner portion, the first cross-sectional thickness being measured along a line bisecting an angle between portions of the outer wall adjacent to the corner portion; the outer wall has a second cross-sectional thickness, the second cross-sectional thickness being a minimum thickness of the outer wall; and a ratio of the first cross-sectional thickness to the second cross-sectional thickness is greater than 1.5.