DE10036597A1 - Filter system for separation of particles from exhaust gas has porous filter component installed in flow path between lower inlet chamber and upper outlet chamber, and has means for release of burnt soot deposits - Google Patents

Abstract

The filter system for the separation of particles from exhaust gas has a porous filter component (8) installed in a flow path (5,6,7) between a lower inlet chamber (2) and an upper outlet chamber (3). The filter has means (12) for the release of burnt soot deposits, and also an ash collecting chamber (14) for the inlet chamber. The ash collecting chamber has a cover (13) which is penetrable by particles. The filter may have at least one vibrating device (15) which may be powered.

Description

For exhaust gas aftertreatment systems on commercial vehicles with Diesel engines are equipped, the arrangement of filters for the separation of particles, especially soot particles, significant. Such filter arrangements have a housing in which came between an inlet chamber and an outlet mer appropriately trained, porous filter body known Are arranged. Such a filter arrangement is for example from EP-B-0 236 817 in its basic structure known.

The surface of the filter body is deposited in the course of Operation soot particles, which in the operating time the through Reduce the casualness of the filter, so that by a appropriate energy supply the accumulated soot on soot ignition temperature must be heated, which then burns, so that the relevant filter body is regenerated again. This Ab burning the soot can be done by motor measures, with the help of the exhaust gas temperature to soot ignition temperature is lifted. Another combination is the combination with fuel additives through which the soot ignition temperature is lowered. By supplying energy at low Temperatures of the soot are burned off. Furthermore, on due to the excess of oxygen in the exhaust gases of a diesel combustion after reaching the soot ignition temperature be self-supporting so that the energy supply after ignition can be switched off again. Such an arrangement for Ignition of the soot deposit is, for example, from EP-B-0 286 932 in the form of ignition wires that have an electrical energy Power source are known.

The burnup is only for a part of the total filter area carried out because of the soot burning in the rain filter part of the exhaust gas flow as a result thermi  shear throttling is reduced. So that the exhaust gas flows redirected to the non-regenerating filter body, so that on the one hand an independent soot burn-up by the regenerie filter is ensured, on the other hand ensured is that during operation, the exhaust gases from the rest Filter bodies continue to be filtered. The soot burns up Deposits alone, however, are not sufficient for the passages restore the filter body, as it burns down the soot deposits also produce a certain amount of ash, which further reduces the permeability of the filter body.

The invention has for its object a filter arrangement creation of the type described in the introduction, in which a Clogging of the filter surface due to ash content avoided becomes.

This object is achieved according to the invention by a fil teranordnung for the separation of particles from the exhaust egg ner piston internal combustion engine, in particular a piston internal combustion engine Engine, for example on a commercial vehicle, with an egg Nem housing in which between a lower inlet chamber and an upper outlet chamber in a flow channel at least a porous filter body is arranged with means for Trigger the burning of soot deposits on the filter body Per surface is provided, as well as with one of the inlet chamber assigned ash collection chamber opposite the exhaust gas flows tion in the inlet chamber with a particle permeable Cover is provided. Due to the essentially vertical Arrangement of the flow channels in the filter bodies can itself as a result of the exhaust gas pulsation and also as a result of the Er vibrations, for example due to vehicle movement the filter surface of deposited ash parts during operation conditions with low flow velocity of the exhaust gases loosen, fall down and into the ash collecting chamber to be caught. Since the ash collecting chamber with an ent Talking cover is provided, even at high Flow velocities that flow through the inlet chamber practically no ash from the ash collection  whirled up and back into the entry channels of the Filter body are entrained. The one in the ash collecting chamber Ashes can then accumulate in front of each other available operating times with simple means the. This will cause clogging to occur over time the pore channels of the filter body through non-flammable parts kel avoided, so that the exhaust gas back pressure even at long Running times, but also when using fuel additi ven to improve the soot filter regeneration remains. Such fuel additives serve to soot the soot lower manure temperature so that with a reduced Burning soot with an energy supply can be achieved via the filter surface.

Since at least two filter bodies are preferably provided, to alternately regenerate them for filter operation can, unless regeneration during breastfeeding is done, is in an advantageous further Ausge staltung of the invention for increasing the filter area vorese hen that at least two filter bodies in flow Direction are arranged one behind the other and that too the second filter body means for triggering the erosion assigned. This arrangement has the advantage that the subdivision of the two filter bodies in modular design each because two successive filter bodies are provided can, which form relatively long filter channels. By the second device for triggering the burnup is despite which ensures that the soot deposits on the ever because filter passage to be regenerated reliably and in full length of the inlet channels are burned.

In a particularly advantageous embodiment of the invention at least one vibrating device is provided. Such Vibration device can move itself or through the vehicle can also be activated by a drive, so that in addition to the vehicle vibrations and intensified during loading driven ash deposits from the filter surface can be removed. When using a drivable  Vibration device can do this periodically, for example when downtimes are activated. Particularly advantageous it is here when the vibrating device turns off the motor is automatically switched on, so that the still hot and dry ash residues in the ash collecting chamber dormant atmosphere can be stored in the inlet chamber NEN.

The term "vibrator" within the scope of the invention summarizes everyone about the vehicle vibrations while driving and / or device that can be activated via a drive, with the vibrations in the filter bodies to be cleaned can be initiated. Such vibrators can each by electromagnetically driven vibrators, electromotive tumblers, pendulum hammers or the like be formed.

In an advantageous embodiment of the invention, that the vibrating device by at least one ne ben that formed by the filter body to be cleaned Flow channel arranged, swinging on a bearing gela gerten hammer body is formed, which in operation to the tub filter body strikes. The advantage of such a gene shaking device is that the hammer body in Vehicle operation due to the changing from outside Accelerations are set in motion, and each time Weil on the walls of the filter body to be cleaned suggests.

In an advantageous, further embodiment of the invention provided that the hammer body with its bearing a change selventil forms with which two flow channels in connection stand, which open out on one side of the hanmer body and which alternately apply compressed air during a pendulum movement be struck, with a channel above the pendulum axis and a channel opens below the pendulum axis, so that the Compressed air exiting the mouths alternately the ham body moved back and forth. This arrangement is in particular re for commercial vehicles that have a compressed air source anyway  are provided for the braking system, particularly advantageous. so probably during operation, but especially with one The piston internal combustion engine can be stopped via the front available compressed air reservoir for a short time are driven and thus the cleaning of the filter body respectively.

The invention is based on schematic drawings of a Embodiment explained in more detail. Show it:

Fig. 1 is a filter assembly, partially in section,

Fig. 2 in detail a swinging hammer body.

The filter arrangement shown in Fig. 1 consists Wesent union of a housing 1 with a lower inlet chamber 2 and an upper outlet chamber. 3 The inlet chamber 2 is connected via an exhaust manifold 4.1 to a piston internal combustion engine and the outlet chamber 3 is connected via an exhaust manifold 4.2 to a silencer device.

Porous filter bodies 8 are arranged next to one another in the housing 1 in three flow paths 5 , 6 and 7 . The filter body 8 are formed, for example, be a so-called monoliths which len with a plurality of parallel Strömungskanä provided 9.1 and 9.2, wherein the flow channels 9.1 2 side remote are closed on its inlet chamber, while the flow channels 9.2, on its inlet chamber 2 facing side are closed. The intermediate walls 10 between the individual flow channels 9.1 and 9.2 are made of a porous material, for example ceramic or metal sintered, so that the gas flow entering the flow channels 9.1 (arrow 11 ) through the housing sewand 10 into the parallel flow channel 9.2 can cross. Particles contained in the exhaust gas stream entering through the exhaust gas manifold 4.1 , in particular soot particles, are deposited on the intermediate wall 10 when the exhaust gases pass through the porous intermediate wall 10 . The exhaust gases flow through the intermediate wall 10 and only then enter the outlet chamber 3 from the flow channel 9.2 of the filter body 8 .

On the inlet side, an activatable device 12 for triggering the soot burnup can be provided on the filter body 8 , for example in the form of a filament. The means for releasing the soot burnup can also be "passive" in nature, ie in the form of catalytically active coatings on the surface or the like. Such devices are known and need not be described in more detail here.

The inlet chamber 2 is provided at a distance above its bottom with a cover 13 in the form of a sheet with holes or Schlit zen 13.1 sheet metal or a temperature-resistant tissue, through which an Aschesam melkammer 14 is divided by the inlet chamber 2 . The holes or slots 13.1 can be protected from the flow (arrows 5 , 6 , 7 ) with deflecting means 13.2 , for example in the form of web-shaped deflectors formed by stamping and shaping, which run transversely to the direction of flow. The particle particles falling off when cleaning from the filter bodies 8 , these are primarily ash particles, then fall through the openings of the cover 13 into the ash collecting chamber 14 and are not whirled up again by the exhaust gas flowing into the inlet chamber 2 . The ash collection chamber 14 is provided with a Entnahmevor direction, not shown here, for example a removable Ka most, a flap preferably arranged in the bottom or a connection for a suction device, so that the collected ash can be removed at predetermined intervals who can.

The arrangement of the filter body is now made such that the operation of each of a filter body ignition energy can be supplied currency rend via the ignition device 12, so that here the combustion of the soot deposits can be carried out, while the other filter located in the flow paths body continue to operate as a filter , In this way, the filter bodies of the individual flow paths 5 , 6 and 7 can be cleaned sequentially in such a way that in each case one flow path is regenerated, while the others filter on the flow paths.

Indicated by the in FIG. 1, modular construction can be with uniform filter bodies 8 by arranging a corresponding number of filter bodies side by side and out behind the other in a matched in size housing a filter arrangement for the different sizes create benbrennkraftmaschinen Kol.

Between the individual filter bodies 8 , a drivable vibrating device 15 , which is shown only schematically here, is arranged, which in operation mutually strikes adjacent bodies and thereby deposits deposited soot particles, but in particular deposited ash particles.

Since the soot accumulation is relatively low when operating a piston internal combustion engine according to the sel process, it is generally sufficient for the vibrating device 15 to be actuated in each of the downtimes between the individual operating times, so that deposited ash parts through the inlet chamber 2 no longer flowed through into the Aschesammelkam mer 14 can fall down. The arrangement can be made so that the vibrator 15 for the filter as a whole is automatically actuated when the piston internal combustion engine is stopped.

In FIG. 2 a drivable by compressed air vibrating device is shown in the form of a hammer mounted delnd pen body 17 on an axis 16 15 schematically. The Hammerkör by 17 is in this case provided with an upwardly directed blow channel 18 which opens into a mouth 19 directed towards the outer wall 8.1 of a fil terkörpers 8 .

Furthermore, a second blowing channel 20 is provided, which is guided downwards from the axis 16 and is directed toward the wall 8.1 of the same filter body 8 with an orifice 21 .

The axis 16 is designed as a shuttle valve and is connected via a central bore 22 with a compressed air supply.

When pressurized, the hammer body 17 is first pivoted away from the outer wall 8.1 by its upper end by the air jet emerging from the mouth 19 . This closes the valve bore 24 connected to the blow duct 18 in the axis 16 , while at the same time a valve bore 25 connects with the lower blow duct 20 , so that the ham body 17 is moved back again via the compressed air jet emerging from the mouth 21 and on the outer wall 8.2 of the adjacent filter body 8 strikes. During this pendulum movement (arrow 23 ) of the hammer body 17 , the upper blowing duct 18 and the lower blowing duct 21 are then acted upon with compressed air, so that the hammer body 17 alternatingly exits against the wall 8.1 of the adjacent fil terkkörper via the compressed air jet emerging from the mouth 19 strikes with its lower end.

Due to the alternating striking of the hammer body 17 on the filter bodies 8 , corresponding vibrations are introduced into these so that the particle particles located on the filter surface, primarily ash particles when the piston internal combustion engine is at a standstill, can fall down through the inlet chamber 2 into the ash collecting chamber 14 . When the vibrating device 15 is started up when the piston internal combustion engine is stopped or shortly after stopping, the dry ash particles on the still hot filter surface have little adhesion and can thus be removed easily and almost completely from the filter surface.

Claims (5)

1. Filter arrangement for the separation of particles from the gas from a piston internal combustion engine, in particular a Kol benbrennkraftmaschine on a commercial vehicle, with a Ge housing ( 1 ) in which between a lower inlet chamber ( 2 ) and an upper outlet chamber ( 3 ) in a flow path ( 5 , 6 , 7 ) at least one porous filter body ( 8 ) is arranged, which is provided with means ( 12 ) for triggering the combustion of soot deposits, as well as with an ash collecting chamber ( 14 ) assigned to the inlet housing ( 2 ), which prevents the exhaust gas flow in the inlet housing ( 2 ) is provided with a particle-permeable cover ( 13 ). 2. Filter arrangement according to claim 1, characterized in that at least one vibrating device ( 15 ) is provided. 3. Filter arrangement according to claim 1 or 2, characterized in that the vibrating device ( 15 ) is drivable ausgebil det. 4. Filter arrangement according to one of claims 1 to 3, characterized in that the vibrating device ( 15 ) is formed next to the filter body ( 8 ) arranged, on a bearing swinging hammer body ( 17 ) which in operation on the wall ( 8.1 ) of the filter body ( 8 ) strikes. 5. Filter arrangement according to one of claims 1 to 4, characterized in that the hammer body ( 17 ) on an axis ( 16 ) forms a shuttle valve with which two flow channels ( 18 , 20 ) are in communication, which on one side of the ham body (17) open out and which are acted on alternately during a reciprocating movement with compressed air, wherein a chan nel (18) opens laterally above the oscillation axis and a channel (20) laterally below the swing arm, so that the turns of the outlets (19, 21) escaping compressed air moves the hammer body ( 17 ) back and forth.