Fumes Treatment System

Abstract

A fumes treatment system is provided for exhaust gases of internal combustion engines, for example. The system includes a housing inside which a series of elements are provided for intercepting the flow of fumes. The elements are such that they do not completely take up the internal cross-section of the housing and are provided with or leave such discontinuities as to create a tortuous path for the fumes to be treated.

1 - 17 . (canceled) 
   
   
       18 . A fumes treatment system comprising a housing having a fumes inlet and an outlet for treated fumes, and a series of essentially planar flow interception elements inside the housing, wherein the elements are formed and arranged such that:
 a) at least two successive interception elements of the series each has at least one discontinuity, such that a geometrical area of the discontinuity comprises between 10 and 40% of an area that the element would have if it completely occupied an internal cross-section of the housing;   b) for any pair of successive interception elements, one being upstream and one being downstream of the other and each having a discontinuity, a projection (P) of the discontinuity of the downstream element on the upstream element, wherein the projection is made perpendicular to the upstream element, does not superimpose with the discontinuity on the upstream element; and   c) a minimum distance between two discontinuities on two successive elements lies along a segment forming an angle α of at least 5° with respect to a straight line perpendicular to the upstream element.   
   
   
       19 . The system according to  claim 18 , wherein the angle α is greater than 15°. 
   
   
       20 . The system according to  claim 18 , wherein the angle α is greater than 30°. 
   
   
       21 . The system according to  claim 18 , wherein the housing has a circular or elliptical shape in a cross-section perpendicular to an axis of the housing. 
   
   
       22 . The system according to  claim 18 , wherein all of the flow interception elements have discontinuities. 
   
   
       23 . The system according to  claim 18 , wherein the flow interception elements are all essentially perpendicular to an axis of the housing and essentially parallel and equidistant to each other, wherein each of the elements has discontinuities, and wherein the angle α is lower than 90°. 
   
   
       24 . The system according to  claim 23 , wherein the angle α is lower than 85°. 
   
   
       25 . The system according to  claim 23 , wherein the flow interception elements are retained in a desired position by hollow cylindrical metal parts having a height equal to a desired distance between two successive elements. 
   
   
       26 . The system according to  claim 23 , wherein the housing has a circular cross-section, the flow interception elements exhibit discontinuities at an internal wall of the housing in a form of segments missing from a circle which would completely take up a cross-section of the housing, and the elements are oriented such that chords defining the segments are all parallel to each other and alternated in successive elements with respect to the axis of the housing. 
   
   
       27 . The system according to  claim 23 , wherein two types of interception elements are present in the housing, a first type having the discontinuity in a form of a central aperture and a second type wherein the discontinuity has a form of at least one aperture in a peripheral area of the element, and wherein elements of the two types are arranged in an alternating manner along the axis of the housing. 
   
   
       28 . The system according to  claim 23 , wherein the angle α between two successive flow interception elements is constant along the axis of the housing. 
   
   
       29 . The system according to  claim 23 , wherein the angle α between two successive flow interception elements increases along the axis of the housing going from the inlet to the outlet of the housing. 
   
   
       30 . The system according to  claim 18 , wherein the flow interception elements comprise a porous metal material having a form selected from a fiber mesh, a porous body of sintered powders, a foam, and combinations of these forms. 
   
   
       31 . The system according to  claim 30 , wherein the elements comprise Fecralloy alloy or AISI 310S steel. 
   
   
       32 . The system according to  claim 30 , wherein the elements are mats comprising multilayers of metal fibers, wherein the layers have different porosities and are formed of fibers of different size. 
   
   
       33 . The system according to  claim 18 , wherein the flow interception elements comprise a ceramic material selected among silicon carbide, cordierite and aluminum titanate. 
   
   
       34 . The system according to  claim 18 , for use as a particulate filter, wherein the flow interception elements comprise two layers of different materials, one layer of solid material and one layer of a material selected from fine metal nets, sintered metal powders and metal fiber meshes.