DE202004006749U1 - Diesel engine exhaust gas filter has corrugated sintered sheet metal channels with converging passage for incoming gas and diverging passages for filtered outgoing gas - Google Patents

Abstract

Exhaust gas particle filter with a filter body (6), made up of one or more arrangements with filter channels (F _an , F _an ) which are alternately end-closed in the flow direction and separated from one another transversely to the flow direction by a filter wall (W _an ), the filter channels (F _an being open _on the inflow side) are) conically tapered in the direction of flow of the filter body and the downstream open filter channels (F _ab) counter to the direction of flow, characterized in that the filter channels (F _in, F _ab) of an arrangement (1) separating filter walls (W _in) with a wave-shaped Sintered metal sheet strips (2) are defined and the filter channels (F _an , F _{ab) are} alternately conically tapered in the transverse direction to extend their alternately end-sealed arrangement.

Description

The invention relates to an exhaust gas particle filter with a filter body, constructed from one or more arrangements with in the flow direction alternately end-sealed, transverse to the flow direction each separated by a filter wall filter channels, the inflow open filter channels in the direction of flow of the filter body and the downstream open filter channels against the flow direction tapered are.

Such exhaust gas particulate filters are in the exhaust line of an internal combustion engine, such as a diesel engine for collecting solid particles transported in the exhaust gas stream, especially soot turned on. Such an exhaust gas particle filter made of sintered metal sheet elements is known from WO 02/102484 A1. The filter body of this known exhaust gas particle filter consists of a large number of individual, wedge-shaped filter bags, each filter pocket having a filter channel open on the outflow side is defined and tapered against the main flow direction. The individual filter bags are also wedge-shaped in their transverse direction, thus by arranging a large number of such filter bags different filter body cross-sectional geometries can be realized, in particular an annular Arrangement of a variety of such filter bags for implementation a filter body with a round cross-sectional area. The filter bags arranged adjacent to one another are in the area the downstream faces of the filter body sealed together at their adjoining wall sections connected, so that two filter bags arranged adjacent to one another, one on the upstream side open, upstream tapering Define filter channel.

The individual filter bags are made from a sintered metal strip. The sintered metal sheet material consists of an opening having carrier, for example a wire mesh or preferably an expanded metal, whose openings are filled with sintered metal powder to form the desired porous filter wall.

Even if the characteristics of a such a filter body comprehensive exhaust gas particle filter are extremely satisfactory, would it be desirable, a filter body with in the direction of flow alternately end-closed and alternately in opposite Direction tapered filter channels with an enlarged effective filter surface on hand, the v. a. can also be produced in a simplified manner can.

This object is achieved by a Exhaust particle filter released, where the the filter channels an arrangement separating filter walls by a wave-like shaped sintered metal sheet strips are defined and the filter channels in the transverse direction to extend their alternately end-closed arrangement alternately conversely tapered are.

This exhaust gas particle filter exists the filter body from one or more filter channel arrangements. The filter channels one such an arrangement are converted into a waveform by a waveform Sintered metal strips defined. They represent the vertices the flanks of the sintered metal sheet strip connecting the waveform each represent a filter wall, the two adjacent filter channels from each other separates. The waveform of the formed sintered metal strip can be curved or straight, connected by edges Have sections.

By spiraling one such an arrangement or by stacking several such arrangements are characterized by the wavy embossing of the Sintered metal sheet strip first only defined filter channels closed or edged, using a smooth Sintered metal sheet strip as an intermediate layer between two arrangements is appropriate. The the filter walls forming flanks of the wave-shaped sintered metal strip to form each filter channel are related to each filter channel inclined in opposite directions to each other, so that the arrangement filter channels in the transverse direction to extend their alternately end-closed arrangement are alternately conically tapered. Through this measure, so-called Filtertoträume be minimized because in combination with the tapered design of the filter channels in or against the flow direction the filter walls running towards each other - if at all - only converge along one side. The across the depth of the filter channels inclined alignment of the filter walls, that are straight or curved in the direction of their inclination can cause a distraction in the upstream inflowing open filter channel Partial exhaust gas flow, which favor passage through the filter walls can. This exhaust particle filter is also not an advantage just the simple design of its filter body, but that the cross-sectional area of the individual filter channels can be relatively small, so that the total number of filter channels with the same filter cross-sectional area compared to the previously discussed State of the art can be enlarged many times, whereby the filter surface is enlarged accordingly.

Without increasing the manufacturing outlay of such a filter body, it is readily possible to design the filter channels that are alternately open on the upstream and downstream sides asymmetrically, for example in order to provide the filter channels open on the upstream side wider than the open on the downstream side. It is provided that the taper angle of the filter defining the filter channels walls to one another both with the upstream open filter channels and with the downstream open filter channels. If the filter channels open on the upstream side are wider than the open on the downstream side with these requirements, they have an ash storage space in the area of their downstream side termination. The ash that arises after the regeneration of such a filter body due to the soot burn-off can then accumulate in the region of each end of an upstream open filter body without the filter surface of the filter body being noticeably reduced.

The invention is based on the following of an embodiment with reference to the attached Figures described. Show it:

1 1 shows a schematic perspective view of a detail of an arrangement with filter channels which are alternately end-closed in the direction of flow to form a filter body

2 : one of several arrangements of the 1 formed filter body in a perspective, partially cut view and

3 : the in 2 shown filter body in a reduced view on its underside.

A filter channel arrangement 1 is in the illustrated embodiment of two filter components 2 . 3 built up. For the filter components 2 . 3 it is sintered metal sheets, consisting of a support having openings (expanded metal in the illustrated embodiment), the openings of which are filled with a sintered metal powder. The sintered sintered metal powder in the openings of the carrier represents the actual filter surface. The filter component 2 is through edges in its in 1 shown waveform has been reshaped. The waveform alternately defines filter channels that are open upwards or downwards. They are closed by the filter component 2 initially only defined filter channels through the filter component designed as a flat sheet 3 on which the filter component 2 is on the hook. By stacking multiple filter assemblies 1 through the bottom of the filter component 3 also in 1 Filter channels of the filter component shown open on the top 2 locked.

In the 1 through the filter component 3 Filter channels sealed on the underside are likewise in the area of their front termination by a solder plug 4 locked. In the 1 Filter channels that are open towards the top, on the other hand, are soldered in the area of their rear end 5 locked. In this way, alternately end-closed filter channels are formed, the filter channels open _on the upstream side being designated by the reference symbol F _an and the filter channels open _on the downstream side being designated by F _ab . The flow direction of the filter channel arrangement 1 is represented by an arrow in this figure.

The plugs of solder 4 . 5 for alternately closing the filter channels F _to, Fab serve for realizing the desired alternate end closure for a. On the other hand, the solder plugs serve 4 . 5 to establish a joint between the two filter components 2 . 3 a filter arrangement 1 as well as for connecting the filter arrangement 1 with others, for example if several such filter arrangements 1 to be stacked to form a filter body.

The filter channels Fan, F _ab are tapered in the direction of their depth (z direction). It is provided that the upstream filter channels Fan taper conically in the flow direction (z-direction), while the downstream filter channels F taper _off in the opposite direction. This mutual tapering means that the flow cross-section of the upstream filter channels Fan decreases in the z-direction, while due to the same taper angle of the opposite tapering of the downstream filter channels F _, the flow cross-section of these filter channels F _{ab increases in} accordance with the decrease in the cross-section of the upstream filter channels Fan , This has a favorable effect on the flow conditions from where the inflowing exhaust gas flows into the filter channels F _at which the filter channels F _to the wall delimiting portions of the filter member 2 respectively. 3 must flow through before it can flow out of the open filter channels F _ab .

Conveniently located on the presence or discharge of the exhaust gas is also inclined formation of the filter channels F F acts _{on, from} the walls defining the filter member 2 out. The oppositely inclined arrangement of these walls defining a filter channel - examples are in 1 two marked a flow channel F open _{on the} upstream side with W _an - form trough-shaped filter channels F _an , F _ab that widen conically in the y direction with respect to the clear width. Thus, the filter channels F _an , F _ab in the transverse direction (y direction) are alternately conically tapered to extend their alternately end-closed arrangement (x direction).

The through the filter component 2 Filter channels Fan, Fab defined due to its corrugation are asymmetrical with regard to their width. The upstream open filter channels F _to have a greater width than the downstream open _onto filter channels F. This implies that at the inflow side open filter channels F _to each other as a result of the taper in the z-direction tapered walls _of W in the area of downstream completion of the filter channel assembly 1 stay spaced from each other. For this reason, the solder plug 5 adjacent the region of the inflow side open filter channels F _to be readily used as an ash storage without the angstrom by successive accumulation of ash in the region of the deepest side channels open filter F reduces the effective filter surface _at markedly.

Out 1 it is also clear that as a result of the tapering of the filter channels F _an , F _ab in the y-direction, filter dead spaces formed by walls which converge and therefore do not have any flow-related effects in the arrangement 1 have been almost completely avoided.

One of several filter channel arrangements 1 the 1 formed filter body 6 of an otherwise not shown exhaust gas particle filter is in 2 shown. The flow direction of the exhaust gas is again indicated by an arrow in this figure. This becomes clear in 2 Stacked arrangement shown that the upstream open filter channels F _{on the} top through the bottom of each filter component 3 are closed. The filter body is used to form an exhaust gas particle filter 6 inserted into a housing (not shown).

In 3 is the filter body 6 reproduced again from its bottom. While in the presentation of the 2 in the topmost position of the filter body 6 Open filter channels F _{an were} present on the upstream side, it is now in the bottom view of the 3 of the filter body 6 to open downstream filter channels F _from.

The insertion of the solder plugs 4 . 5 is useful when stacking the individual filter components 2 . 3 introduced into the stack, it being sufficient if solder strands are stacked in the area of the intended closures. After the introduction of such as in the 2 and 3 formed stack in an oven, the solder runs by itself in the end regions of adjacent channels open filter F _at or F _and forms then illustrated in the figures Lotpfropfen 4 respectively. 5 out.

Without further ado, the in 1 filter channel arrangement shown only as a detail can also be wound spirally to form a filter body, the winding axis running parallel to the longitudinal extension of the filter channels F _ab , F _ab . Both filter components can then be used 2 . 3 unrolled from a reel. It is then expedient in the area of the edge of the filter component 2 a paste user solder application of a suitable composition should be introduced into the winding on the top and bottom sides in order to form the solder plugs desired for the end closure after the wound arrangement has been introduced.

The end closure of the filter channels F _an , F _{ab described} by solder plugs described in the figures 4 . 5 can also be realized in other ways. For example, the filter channels F _on or F _{from the} end can also be introduced by inserting a plug made of other material or by a deformation of the filter component closing the respective channel 2 be educated.

1

Filter channel arrangement

2

filter component

3

filter component

4

Loftpfropfen

5

Lotpfropfen

F _on

inflow open filter channel

F _from

downstream open filter channel

W _on

Filter channel wall

Claims (7)

Exhaust particle filter with a filter body ( 6 ), made up of one or more arrangements with filter channels (F _an , F _an ) which are alternately end-closed in the flow direction and separated from each other by a filter wall (W _an ), the filter channels (F _an ) open _on the inflow side in the flow direction of the filter body and the filter channels (F _ab ) open on the outflow side are conically tapered counter to the flow direction, characterized in that the filter channels (F _an , F _ab ) of an arrangement ( 1 ) separating filter walls (W _an ) through a wave-shaped sintered metal strip ( 2 ) are defined and the filter channels (F _an , F _ab) are tapered transversely to extend their alternately end-sealed arrangement. Exhaust gas particle filter according to claim 1, characterized in that with the same taper angle of the conical taper of the filter channels (F _an , F _ab ) in or against the flow direction, the upstream open filter channels (F _an ) have a greater width than the open downstream filter channels (F _ab ). Exhaust gas particle filter according to Claim 1 or 2, characterized in that the filter walls (W _an ) are provided to run essentially straight in the transverse direction to their longitudinal extent pointing in the flow direction. Exhaust gas particle filter according to claim 3, characterized in that the sintered metal sheet strip ( 2 ) an arrangement for forming the waveform defining the filter channels (F _an , F _ab ) is folded. Exhaust gas particle filter according to one of claims 1 to 4, characterized in that the filter body ( 6 ) several stacked arrangements ( 1 ) includes. Exhaust particle filter according to one of claims 1 to 4, characterized in that the filter body from a jointly with a separating layer spiral rolled up arrangement is formed. Exhaust gas particle filter according to claim 6, characterized in that that the separating layer is a smooth sintered metal strip.