Abstract: A device for reducing pollution of an internal combustion engine, including a collection of monolithic elements of honeycomb type connected by a jointing compound, each element incorporating a set of adjacent cells of mutually parallel axes separated by porous walls, which cells are plugged by plugs at one or other of their ends to delimit inlet chambers opening onto a gas intake face and outlet chambers opening onto a gas discharge face such that gas that is to be filtered passes through the porous walls, the collection being inserted in a metal casing by a compacted fibrous mat. A jointing compound has a three-point flexural modulus of rupture of between 0.5 and 6 MPa, the jointing compound has a dynamic Young's modulus less than or equal to 17 GPa, the mat has a mean density in the compacted state of between 0.30 and 0.54, and the mean thickness of the mat in the compacted state is between 2 and 8 mm.

Abstract: The subject of the invention is a gas filter structure for filtering particulate-laden gases, of the honeycomb type and comprising an assembly of longitudinal adjacent channels (21, 22) of mutually parallel axes separated by porous filtering walls (23), said channels (21, 22) being alternately blocked off at one or the other of the ends of the structure so as to define inlet channels (21) and outlet channels (22) for the gas to be filtered and so as to force said gas to pass through the porous walls (23) separating the inlet (21) and outlet (22) channels, said structure being such that, in cross section: the ratio R of the sum of the areas of the inlet channels to the sum of the areas of the outlet channels is greater than 1; at least some of the porous walls (23) are wavy so as to be concave relative to the center of the inlet channels (21) and convex in their middle relative to the center of the outlet channels (22); and the outlet channels (22) possess at least one rounded corner (25).

Abstract: The invention relates to an assembly consisting of a device for detecting radial cracks in a particulate filter of the honeycomb type, of which the filtering part is made up of a porous inorganic material, said particulate filter comprising a single monolithic element or being obtained by combining a plurality of monolithic elements, the device being characterized in that it comprises an electrically conducting material arranged in the form of a strip or of a wire on at least one longitudinal part of the filter, secured to a monolithic element and/or to the coating cement or the jointing cement, and having an electrical conductivity greater than that of the material that makes up that part of the filter to which it is secured, and a strength less than or equal to that of the material that constitutes that part of the filter to which it is secured, and means of measuring the conductivity or the electrical resistance of the strip or wire of electrically conducting material.

Abstract: A nondestructive method for detecting internal defects of a filter, for example a catalytic filter, and a device for implementing the method. The method may be used in particular for treating a gas laden with soot particulates. The filter includes a honeycomb filter element or a plurality of honeycomb filter elements. In the method the presence or absence of the defects is determined by measuring a propagation of a gas stream such as air through the filter element or elements.

Abstract: The invention relates to a catalytic filter for the treatment of a gas laden with soot and pollutant particles in a gas phase, comprising a plurality of monolithic honeycomb blocks connected together by a jointing cement, the thermal conductivity of which is greater than 0.3 W/m.K, said filter being characterized in that at least the monolithic blocks placed in the central part of the filter, and preferably all of the monolithic blocks, have, along a radial direction, a peripheral portion whose total filtration area is greater than the total filtration area of the central portion of said blocks.

Abstract: The invention relates to a method for measuring the uniformity of the deposit of soot in a particulate filter, comprising the steps consisting in measuring, simultaneously or in succession, the respective characteristic quantities of at least two gas streams each having passed through a different longitudinal portion of said filter, and then in comparing the characteristic quantities thus measured. It also relates to a method for controlling the regeneration of a particulate filter, comprising the steps consisting in measuring the uniformity of the soot deposit in said filter and in adjusting the parameters of said regeneration according to the uniformity value obtained.