FI20185870A1

FI20185870A1 - Exhaust gas after-treatment system and method for the exhaust gas after-treatment

Info

Publication number: FI20185870A1
Application number: FI20185870A
Authority: FI
Inventors: Axel Fiedler; Andreas Döring
Original assignee: Man Energy Solutions Se
Priority date: 2017-10-18
Filing date: 2018-10-16
Publication date: 2019-04-19
Also published as: JP7187250B2; KR20190043476A; DE102017124225A1; KR102515878B1; JP2019074089A; CN109681293A; CN109681293B

Abstract

An exhaust gas after-treatment system (2) for an internal combustion engine (1), having a particle separator (3) arranged downstream of an internal combustion engine (1) consisting of at least one particle separator module (6) for removing soot and ash particles from the exhaust gas, wherein exhaust gas to be cleaned can be fed to the particle separator (3) via at least one exhaust gas feed line, wherein in the particle separator (3) cleaned exhaust gas can be discharged from the particle separator (3) via at least one exhaust gas discharge line, wherein the respective particle separator module (6) comprises multiple exhaust gas flow passages (10) through which exhaust gas can flow, via which the exhaust gas emanating from the exhaust gas feed line can be conducted in the direction of the exhaust gas discharge line, wherein the exhaust gas flow passages (10) are delimited By neighbouring flow-control elements (8, 9), which in the exhaust gas flow passages (10) delimit macroscopic structures such as flow deflection zones with turbulent exhaust gas flow and/or dead zones of flow and/or flow zones with different flow velocities, wherein the respective particle separator module (6) comprises multiple cleaning passages (11) through which exhaust gas and/or compressed air can flow, which run transversely to the exhaust gas flow passages (10) and which are likewise delimited by the flow-control elements (8, 9), wherein in such sections of the flowcontrol elements (8, 9), which separate the exhaust gas flow passages (10) from the cleaning passages (11), recesses for the passage of exhaust gas flowing through the cleaning passages (11) and/or compressed air flowing through the cleaning passages (11) are introduced, via which surfaces of these sections of the flow-control elements (8, 9) facing the exhaust gas flow passages (10) can be cleaned of soot and/or ash.

Description

EXHAUST GAS AFTER-TREATMENT SYSTEM AND METHOD FOR THE EXHAUST GAS AFTER-TREATMENT

The invention relates to an exhaust gas after-treatment system. The invention, furthermore, relates to a method for the exhaust gas after-treatment.

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From practice, exhaust gas after-treatment systems of internal combustion engines are known which as exhaust gas after-treatment assemblies comprise at least one further exhaust gas after-treatment assembly which seen in the flow direction of the exhaust gas is arranged upstream of the particle filter and/or at least one further exhaust gas after-treatment assembly which seen in the flow direction of the exhaust gas is arranged downstream of the particle filter. An exhaust gas after-treatment assembly positioned, seen in the flow direction, upstream of the particle filter is in particular an oxidation catalytic converter for oxidising nitrogen monoxide (NO) into nitrogen dioxide (NO₂) · An exhaust gas after-treatment assembly which, seen in the flow direction, is positioned downstream of the particle filter can be a silencer. In particular when seen in the flow direction of the exhaust gas flow an oxidation catalytic converter for the oxidation of NO into NO2 is positioned upstream of the particle filter, oxidation in the oxidation catalytic converter of NO into NO2 takes place with the help of the residual oxygen O2 contained in the exhaust gas flow according to the following equation:

NO + O₂ 2 NO₂

During nitrogen reaction nitrogen this oxidation of nitrogen monoxide into dioxide, at high monoxide .

the equilibrium of the oxidation temperatures is on the side of

This has the consequence that at high temperatures the nitrogen dioxide proportion that can be achieved is greatly limited.

In the particle filter, the nitrogen dioxide obtained in the oxidation catalytic converter is converted with carbon-containing particles, so-called soot, accumulating in the particle filter into carbon monoxide (CO), carbon dioxide (CO2) , nitrogen (N2) and nitrogen monoxide (NO) . In the process, a continuous removal of the carbon-containing particulate matter or of the soot accumulated in the particle filter for the purposes of a passive regeneration of the particle filter takes place, wherein this conversion takes place according to the following equations:

NO₂ + C 2 NO + CO₂

NO₂ + C NO + CO

C + 2 NO₂ N₂ + 2 CO₂

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In particular when with such a passive regeneration of the particle filter no complete conversion of the carbon-containing particulate matter or of the soot accumulated in the particle filter can take place, the carbon proportion or soot proportion in the particle filter increases, wherein the particle filter then has a tendency towards clogging, as a result of which ultimately a so-called exhaust gas backpressure on an internal combustion engine connected upstream of the exhaust gas after-treatment system increases. An increasing exhaust gas backpressure on the internal combustion engine diminishes the power of the internal combustion engine and causes an elevated fuel consumption.

In order to avoid an increase of the carbon-containing particulate matter or of the soot in the particle filter and thus a clogging of the same it is already known from practice to provide particle filters with a catalytic coating. Here, platinum-containing coatings are preferentially employed. The use of such particle filters with catalytic coating however can prevent the charging of the particle filter with carbon-containing particulate matter, i.e. with soot, only to an inadequate degree.

In particular when, as is typically the case on diesel

internal	combustion	engines	of	ships, t	he internal
combustion	engine,	in which	the	exhaust	gas	after-
treatment	system is	operated,	is	operated	with	highly

sulphur-containing fuel such as for example with heavy fuel oil, there is the further problem that as a consequence of the high incurrence of ash and soot a clogging of a particle filter of the exhaust gas aftertreatment system can likewise occur. In particular in the case of internal combustion engines operated with heavy fuel oil maintenance intervals of particle

filters	can	be	shortened so dramatically 1	by	the
incurred	ash	and	soot that a practical	operation	of	the
exhaust	gas	after-treatment system	is no	longer
possible .

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For the above reasons it is therefore already known from practice to replace particle filters in the exhaust gas after-treatment systems by filterless particle separators. In the case of a particle separator, the exhaust gas does not flow through any filter medium, but the exhaust gas flow is rather conducted and deflected along a textured surface in order to thereby separate particles.

From EP 1 072 765 B2 a method for the separation of particles from the exhaust gas of internal combustion engines is known. Particles are separated by way of diffusion in dead zones of flow. The separation of

20185870 prh 16-10-2018 particles from the exhaust gas by diffusion is easily possible according to the method known from EP 1 072 765 B2, there is however the problem that in the case of unsteady internal combustion engine operation, adequate NO2 is frequently not available in order to oxidise separated carbon. For this reason, the particle separator has to store the particles until at a later time adequate NO2 for the oxidation of the carbon is available. However, the particle filter must not clog in the process.

A further particle separator is known from DE 10 2008 029 520 Al. In this particle separator, exhaust gas is also steadily deflected in order to separate particles from the exhaust gas.

There is a need for an exhaust gas after-treatment system with a particle separator, in which separated particles, in particular carbon particles, can be intermediate-stored for a later oxidation and from which soot and ash can be discharged for avoiding clogging of the particle separator. Starting out from this, the present invention is based on the object of creating a new type of exhaust gas after-treatment system and a new type of method for the exhaust gas after-treatment.

This object is solved through an exhaust gas aftertreatment system according to claim 1. The exhaust gas after-treatment system comprises at least one particle separator module for removing soot and ash particles from the exhaust gas, wherein exhaust gas to be cleaned can fed to the particle separator via at least one exhaust gas feed line, wherein exhaust gas cleaned in the particle separator can be discharged from the particle separator via at least one exhaust gas discharge line, wherein the respective particle

20185870 prh 16-10-2018 separator module comprises multiple exhaust gas flow passages through which exhaust gas can flow, via which the exhaust gas, emanating from the exhaust gas feed line, can be conducted in the direction of the exhaust gas discharge line, wherein the exhaust gas flow passages are delimited by neighbouring flow-control elements, which in the exhaust gas flow passages delimit macroscopic structures such as flow deflection zones with turbulent exhaust gas flow and/or dead zones of flow and/or flow zones with different flow velocities, wherein the respective particle separator module comprises multiple cleaning passages through which exhaust gas and/or compressed air can flow, which run transversely to the exhaust gas flow passages and which are likewise delimited by the flow-control elements, and wherein at least in such sections of the flow-control elements, which separate the exhaust gas flow passages from the cleaning passages, recesses for the passage of exhaust gas flowing through the cleaning passages and/or for the passage of compressed air flowing through the cleaning passages are introduced, via which surfaces of the flow-control elements facing the exhaust gas flow passages can be cleaned of soot and/or ash.

In the case of the particle filter of the exhaust gas after-treatment system according to the invention, carbon particles can be intermediate-stored for oxidation, ash and soot can, furthermore, be discharged for avoiding a blockage of the particle filter. The carbon particles are separated via diffusion and/or convection of the particles on surfaces of the exhaust gas flow passages. By way of the cleaning passages, via which compressed air and/or exhaust gas can be conducted, ash and soot can be effectively removed from the particle filter.

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According to a further development, the surfaces of the flow-control elements facing the exhaust gas flow passages form microscopic structures. Preferentially, the microscopic structures enlarge an effective surface area of the macroscopic structures, wherein the microscopic structures preferentially have a roughness between 0.05 pm and 50 pm. The microscopic structures on the surfaces of the flow-control elements facing the exhaust gas flow passages improve the separation of the particles from the exhaust gas via diffusion and/or convection. Here, the roughness of the microscopic structures between 0.05 pm and 50 pm is particularly preferred in order to form a thin, stagnating boundary film of separated particles, in which the flow velocity tends to zero. Accordingly it can be avoided that particles are again torn free by the flow.

According to a further development, the flow-control elements comprise flow-control elements that are flat or contoured two-dimensionally and flow-control elements which are undulating or contoured threedimensionally, which alternately are designed sandwichlike or stack-like forming multiple layers of exhaust gas flow passages and cleaning passages. Preferentially, the three-dimensionally contoured flowcontrol elements as macroscopic structures form flowconducting contours extending in the direction of the exhaust gas flow passages, flow-accumulating contours extending transversely to the direction of the exhaust gas flow passages and flow-conducting openings.

Flow-control elements arranged sandwich-like or stacklike on top of one another, which form or delimit the exhaust gas flow passages and cleaning passages, are particularly preferred for separating carbon particles by way of diffusion and/or convection and for cleaning the particle filter of ash and soot.

According to a further advantageous further development, the flow-control elements have a wall thickness between 40 pm and 150 pm, preferably between 40 pm and 100 pm, particularly preferably between 40 pm and 60 pm. Such a thin wall thickness of the flowcontrol elements allows an effective flow control, effective separation of carbon particles and effective cleaning of the particle separator in each case with compact design.

The method for the exhaust gas after-treatment according to the invention is defined in claim 14.

Preferred further developments of the invention are obtained from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail by way of the drawing without being restricted to this. There it shows:

Fig. 1: a block diagram of an exhaust gas aftertreatment system;

Fig. 2: a detail of Fig. 1.

20185870 prh 16-10-2018 invention present here relates to an after-treatment system preferentially employed on a sulphur-containing

The for an internal exhaust gas combustion engine, engine highly heavy fuel oil.

for an internal combustion ship, fuel which is operated with such as for example with

Fig. 1 shows an exemplary embodiment of an exhaust gas after-treatment system 2 positioned downstream of an internal combustion engine 1. The exhaust gas aftertreatment system 2 of Fig. 1 comprises a particle separator 3 positioned downstream of the internal combustion engine.

It is pointed out here that both seen in the flow direction of the exhaust gas upstream of the particle separator 3 and also seen in the flow direction of the exhaust gas downstream of the particle separator 3 at least one further exhaust gas after-treatment component of the exhaust gas after-treatment system can be positioned in each case.

Upstream of the particle separator 3, for example an oxidation catalytic converter for the oxidation of NO into NO2 can be positioned. Downstream of the particle separator 3, for example a silencer can be positioned.

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Exhaust gas 4 to be cleaned can be fed to the particle separator 3 via an exhaust gas feed line which is not shown in detail.

After the exhaust gas to be cleaned has flowed through the particle separator 3, cleaned exhaust gas 5 can be discharged from the particle separator 3, preferentially via at least one exhaust gas discharge line which is likewise not shown in detail.

In the block diagram of Fig. 1, the particle separator 3 comprises two particle separator modules 6. These two particle separator modules 6 shown in Fig. 1 are connected in parallel.

It is pointed out here that additionally or alternatively to such particle separator modules 6 connected in parallel, a particle separator 3 can also comprise particle separator modules 6 connected in series .

Each particle separator module 6 of the particle separator 3 comprises multiple exhaust gas flow passages 10 through which exhaust gas can flow (see Fig. 2, 3), via which the exhaust gas, emanating from the exhaust gas feed line can be conducted in the direction of the exhaust gas discharge line. The flow passages elements neighbouring flow-control ceramic are delimited by

8, 9 which preferentially are metallic and/or and/or containing containing, form or and/or which quartz-containing silicon-containing in the exhaust and/or glassand/or silicateflow passages 10 structures in gas millimetre delimit macroscopic (mm) size range or particular flow deflection zones centimetre (cm) range, in turbulent exhaust gas flow and/or dead zones of the size with flow and/or flow zones with different flow velocities.

In addition to the region of separated respective comprises multiple which exhaust gas flow passages 10, in in particular carbon particles diffusion and/or the are by particle separator module cleaning passages convection, in each the case through which exhaust gas and/or compressed air can flow, which run transversely to the exhaust gas flow passages 10 and are likewise delimited by the flow-control elements 8, 9.

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Some of the flow-control elements 8, 9 or sections of the same accordingly delimit on the one hand on a first side one of the exhaust gas flow passages 10 and on a second side one of the cleaning passages 11. In such flow elements 8, 9 or at least in such sections of the flow-control elements 8, 9, which on the one hand separate the exhaust gas flow passages 10 and on the other hand the cleaning passages 11 from one another, recesses for the passage of exhaust gas flowing through the cleaning passages 11 and/or of compressed air flowing through the cleaning passages 11 are introduced, via which surfaces or surface sections of the flow-control elements 8, 9 facing the exhaust gas flow passages 10 can be cleaned of soot and/or ash in that the exhaust gas and/or the compressed air flowing via the cleaning passages 11 flows via these recesses and thus cleans the surfaces or surface sections of the flow-control elements 8, 9 facing the exhaust gas flow passages 10 of soot and/or ash.

The flow-control elements 8, 9 on the one hand comprise flat, plate-like and thus two-dimensionally contoured flow-control elements 8 and on the other hand undulating and thus three-dimensionally embodied flowcontrol elements 9 which, as is evident from Fig. 2 and 3, are alternately arranged sandwich-like or stack-like on top of one another, namely forming multiple layers of exhaust gas flow passages 10 and cleaning passages 11.

The flow-control elements 8, 9 in this case preferentially have a wall thickness between 40 pm and 150 pm, preferably between 40 pm and 100 pm, particularly preferably between 40 pm and 60 pm, so that the same accordingly are formed film-like.

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The flow-control elements 8, 9 can also be embodied as expanded metal layers or lattice-like.

The three-dimensionally contoured flow-control elements 9 in this case form as macroscopic structures, flowconducting contours 12 extending in the direction of the exhaust gas flow passages 10 and flow-accumulating contours 13 extending transversely to the direction of the exhaust gas flow passages 10, just like flowconducting openings 14, in which turbulent flows are typically formed. The three-dimensionally contoured

20185870 prh 16-10-2018 flow-control elements 9 can be undulating expanded metal layers.

In each case, the two-dimensionally contoured flowcontrol elements 8 separate two neighbouring threedimensionally contoured flow-control elements 9 from one another and form, as macroscopic structures, flowconducting openings 15. The two-dimensionally contoured flow-control elements 8 can be smooth expanded metal layers .

Exhaust gas, which flows through an exhaust gas flow passage 10 of a layer and accumulates in the region of a flow-accumulating contour 13 of this layer, is forced to flow via a flow-conducting opening 14 either into another exhaust gas flow passage 10 in a neighbouring layer or into the following cleaning passage 11 and an opening 14 of a following flow-conducting contour 12 into an exhaust gas flow passage 10 of the same layer, wherein this exhaust gas in the region of this exhaust gas flow passage can then again flow so far in the direction of the exhaust gas discharge line until the exhaust gas again enters the region of a following flow-accumulating contour 13.

By way of this following flow-accumulating contour 13, the exhaust gas is again forced to flow via an opening 14 into a flow-conducting passage 10 of a neighbouring layer or via the following cleaning passage 11 and an opening 14 of the following flow-conducting contour 12 into an exhaust gas flow passage 10 of the same layer.

Accordingly, the exhaust gas flowing via the flowconducting passages 10 does not flow through any filter medium, but the exhaust gas is forced to undergo a flow deflection multiple times, wherein in the process particles can separate by diffusion and/or convection in particular in the region of the flow-accumulating contours 13, on which dead zones of flow form.

In order to promote the separation of particles from the exhaust gas by diffusion and/or convection, microscopic structures are formed on the flow-control elements 8, 9, namely on surfaces or surface sections of the flow-control elements 8, 9 facing the flowconducting passages 10, i.e. structures in the micrometer (pm) range, in order to establish in the region of these surfaces a roughness of preferentially between 0.05 pm and 50 pm and by way of this enlarge an effective surface area of the macroscopic structures.

In particular when the roughness of the microscopic structures is between 0.05 pm and 50 pm, a thin, stagnating boundary film can be formed in the region of the macroscopic structures, in which the flow velocity tends to zero. By way of this it is avoided that particles separated in the region of the roughened surfaces can be again torn loose by the exhaust gas flow.

The microscopic structures, which can be formed in particular in the region of flow-accumulating macroscopic structures, can be formed by mechanical processing and/or by chemical treatment of the

20185870 prh 16-10-2018 respective surfaces.

Accordingly it is possible to adjust on the surfaces of the macroscopic structures the roughness of the surfaces by brushing and/or grinding and/or scraping and/or blasting and/or stamping and/or needling forming microscopic structures so that the microscopic structures are then formed as brushed structures and/or ground structures and/or scraped structures and/or peened structures and/or stamped structures and/or needle structures. It is possible, furthermore, to form the microscopic structures by a chemical treatment such as etching and/or galvanising and/or anodising, so that the microscopic structures are then formed as etched structures and/or galvanised structures and/or anodised structures. Furthermore, a corona treatment of the surfaces for forming the microscopic structures can take place.

Furthermore, an alloying of the preferentially metallic material of the flow-control elements 8, 9 can be adapted, so that the surface structure of the same changes under the effect of heat and/or under the effect of a variation of the ph-value.

An example for this is the introducing of aluminium in the alloy of the flow-control elements 8, 9. At high temperatures, the aluminium migrates to the surface where it forms aluminium clusters. The alloying material for the flow-control elements can be selected so that the surface of the same can be easily corroded or oxidised.

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Because of this it is possible to increase the roughness of the surface in the region of the exhaust gas flow passages 10 during the operation of the internal combustion engine by the oxidising and corrosive atmosphere of the exhaust gas. This is successful even after a short running-in phase so that a mechanical or chemical treatment of the surface of the flow-control element can then be dispensed with.

Applying metallic powder with subsequent fixing of the powder to the flow-control elements by soldering or sintering is also possible in order to form defined microscopic structures with a defined roughness.

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As already explained, the flow-control elements 9 are three-dimensionally contoured. In addition to this, the flow-control elements 9 can be undulated and/or contoured concertina-like.

In order to effectively clean the surfaces of the flowcontrol elements 8, 9 facing the exhaust gas flow passages 10 and serving for the particle separation via diffusion and/or convection which in particular form the flow-accumulating structures 13, recesses are introduced into sections of the flow-control elements 8, 9, in particular by way of perforations or slits, through which the exhaust gas and/or compressed air, which flows through the cleaning passages 11, is steered into the exhaust gas flow passages 10 and thus remove soot and/or ash from the surfaces.

The cleaning passages 11 in this case extend transversely to the exhaust gas flow passages 10, in particular the cleaning passages 11 include with the exhaust gas flow passages 10 an angle between 20° and 160°, preferably an angle between 50° and 120°, particularly preferably an angle between 80° and 100°, in particular of 90°. Here, the cleaning passages 11 are preferentially closed at one end in order to conduct the exhaust gas conducted via the cleaning passages 11 or the compressed air conducted via the cleaning passages 11 through the recesses or perforations into the corresponding sections of the flow-control elements 8, 9.

The dimensions of the macroscopic structures are preferentially in the millimetre range or centimetre range and accordingly are many times larger than the dimension of the largest particles to be separated. Macroscopic openings for the flow are preferentially arranged so that they promote the formation of turbulent flows. Furthermore, the formation of dead zones of flow is promoted. Regions with different flow velocities are formed.

The flow-control elements 8, 9 of each particle separator module 6 are enclosed in a canister in order to provide the respective particle separator module 6 in this way. Multiple particle separator modules 6 can be positioned in a common housing 17 forming a parallel connection and/or series connection of particle separator modules 6. Fig. 1 shows highly schematically such a housing 17 for multiple particle separator modules 6 and a canister 16 for the respective particle separator module 6. The particle separator modules 6 are preferentially arranged in the common housing 17 in such a manner that the particle separator modules 6 can be removed from the housing 17 in a non-destructive manner .

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By way of the canisters 16, neighbouring particle separator modules 6 can be sealed against one another, e.g. via contours inserted into one another according to the key-lock principle via tapers and cones of the canisters 16.

By way of the housing 17 of a particle separator 3, the particle separator modules 6 can be both supplied with the exhaust gas to be cleaned and cleaned exhaust gas can be discharged via the housing 17. Compressed air, which is conducted via the cleaning passages 11 of the particle separator modules 6 can also be supplied to the same via the housing 17 of the particle separator 3. Here, a collection chamber can be formed in the housing, namely a collection chamber for exhaust gas and a collection chamber for compressed air in order to conduct exhaust gas and compressed air emanating from this collection chamber in the direction of the exhaust

20185870 prh 16-10-2018 gas flow passages 10 and cleaning passages 11. The compressed air conducted via the cleaning passages 11 is preferentially passed on from particle separator module 6 to particle separator module 6.

For the exhaust gas after-treatment, the exhaust gas flow passages 10 and the cleaning passages 11 are not preferentially flowed through simultaneously. It is provided, in particular, that in particular when an exhaust gas after-treatment system comprises two or more particle separators 3, and in particular when a first particle separator 3 is utilised for the exhaust gas cleaning and in the process, exhaust gas is conducted through the exhaust gas flow passages 10 of the same, a second particle separator 3 is cleaned and for this purpose exhaust gas and/or compressed air is conducted through the cleaning passages 11 of the same, wherein in the region of the second particle separator 3 the exhaust gas flow through the exhaust gas flow passages 10 of the same is then preferentially completely stopped or alternatively reduced.

In addition, the method can be improved in that in the cleaning phases, in which the soot and the ash is swirled up, an extraction of these swirled-up solids from the particle separator 3 and subsequent collection in a suitable container takes place. This can be emptied at a future time.

For producing a particle separator according to the invention, the flow-control elements 8, 9 are provided, wherein the microscopic structures on the flow-control elements 8, 9 can be formed either before or after the formation of macroscopic structures.

The forming of the microscopic structures is preferentially effected by blasting and/or grinding and/or stamping and/or needling and/or etching and/or galvanising and/or anodising and/or brushing and/or corona irradiation or the like.

For producing a particle separator module 6 the procedure can be such that basic bodies for the flowcontrol elements 8, 9 are initially provided with microscopic structures by particle blasting and/or grinding and/or stamping and/or needling and/or etching. Following this, macroscopic structures are formed by forming or soldering-on or welding-on, wherein in this way the three-dimensionally contoured flow-control elements 9 are formed. By stamping or punching, the openings 14, 15 can be created which in the finish-mounted state form the connection of

20185870 prh 16-10-2018 neighbouring exhaust gas flow passages 10. Following this, stacks of flow-control elements 8, 9 are formed by layering three-dimensionally contoured flow-control elements 9 on top of one another preferentially alternating with two-dimensionally contoured flowcontrol elements 9. In particular, such a stack can be formed into an approximately cylindrical body by Sshaped twisting preferentially perpendicularly to the running direction of the exhaust gas flow passages. Such a body can be arranged in a canister 16. Flowcontrol elements 8, 9 of a stack or cylindrical body arranged on top of one another can be permanently joined to one another for example by welding or soldering. The microscopic structures can also be formed following the completion of the macroscopic structures. For forming the microscopic structures, a stack formed by stacking up flow-control elements 8, 9 can be provided with a microscopic structure on all surfaces by dipping into an etching solution and subsequent removing of the etching solution.

REFERENCE LIST

Internal combustion engine

Exhaust gas after-treatment system

Particle separator

Exhaust gas to be cleaned

Cleaned exhaust gas

Particle separator module

Compressed air

Flow-control element

Exhaust gas flow passage

Cleaning passage

Flow-conducting contour

Flow-accumulating contour

Flow-conducting opening

Canister

Housing

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DE 10 2017 124 225.2

Claims

The claims

An exhaust after-treatment system (2) for an internal combustion engine (1), comprising a particle separator (3) disposed downstream of the internal combustion engine (1) and comprising at least one soot and ash particle separator module (6).

For removing the gas from the exhaust gas, wherein the exhaust gas to be purified can be fed to the particulate separator (3) via at least one exhaust conduit, wherein the purified exhaust gas in the particulate separator (3) can be removed from the particulate separator (3) through

10 wherein the respective particulate separator module (6) comprises a plurality of exhaust flow flow passages (10) through which the exhaust gas can flow and through which the exhaust gas flowing from the exhaust gas supply line can be guided in the direction of the exhaust gas flow 10) macroscopic structures such as flow deflection zones having turbulent exhaust flow zones and / or flow dead zones and / or flow zones having different flow rates, wherein the respective particulate separator module (6) and flow and transverse to the exhaust flow paths (10) and which is likewise limited by the flow control elements (8,9), wherein at least the portions of the flow control elements (8, 9) taking the exhaust gas flow ducts (10) from the cleaning ducts (11), there are 25 recesses for the exhaust gas flowing through the cleaning duct (11) and / or the compressed air flow through the cleaning ducts (11); can be cleaned of soot and ash.

An exhaust aftertreatment system according to claim 1.

30, characterized in that the surfaces of the flow control elements (8, 9) facing the exhaust flow channels (10) form microscopic structures.

Exhaust after-treatment system according to claim 2, characterized in that the microscopic structures are formed in the bottom

20185870 prh 16-10-2018 as structures and / or stamped structures and / or needle structures and / or brush structures and / or interrupted structures and / or etched structures and / or anodized structures and / or galvanized structures.

An exhaust aftertreatment system according to claim 2 or 3

5, characterized in that the microscopic structures have a roughness between 0.05 and 50 µm.

Exhaust gas treatment system according to one of Claims 2 to 4, characterized in that the microscopic structures constitute the effective surface area of the macroscopic structures.

10

Exhaust after-treatment system according to any one of claims 1 to 5, characterized in that the macroscopic structures have dimensions in the mm or cm range and the microscopic structures in the pm range.

Exhaust after-treatment system according to one of claims 1 to 6, characterized in that the purification ducts (11) and the exhaust

The background channels (10) include an angle of 20 ° to 160 °, preferably 50 ° to 120 °, particularly preferably 80 ° to 100 °.

Exhaust after-treatment system according to one of Claims 1 to 7, characterized in that the flow control elements (8,9) comprise two-dimensionally shaped flow control elements (8) and a three-way flow control element (8).

20 mentally shaped flow control elements (9) arranged alternately in a sandwich manner or stacked to form a plurality of layers of exhaust flow channels (10) or purification channels (11).

Exhaust after-treatment system according to claim 8, characterized in that the flow control elements (8,9) have a diameter of 40 to 150 µm.

Wall thickness, preferably between 40 and 100 µm, particularly preferably between 40 and 60 µm.

Exhaust after-treatment system according to claim 8 or 9, characterized in that the three-dimensionally shaped flow control elements (9) develop as flow control elements in the form of macroscopic structures.

30 in the form of shapes (12) extending in the direction of the exhaust flow channels, flow collection shapes (13) extending transversely of the exhaust flow channels and flow control openings (14).

Exhaust after-treatment system according to any one of claims 8 to 10, characterized in that the two-dimensionally shaped stream

The background control elements (8), as macroscopic structures, form flow control openings (15).

Exhaust after-treatment system according to one of Claims 1 to 11, characterized in that the flow control elements (8,9) of the respective particulate separator modules [6] are closed by a container.

Exhaust gas treatment according to any one of claims 1 to 12

5, characterized in that a plurality of particulate separator modules (6) are arranged in a common housing where they are connected in parallel and / or in series.

Method according to one of Claims 1 to 13, characterized in that the soot and ash particles swirl in the cleaning steps of the particulate separator module (6), are removed from the particulate separator module (6) and collected in a container.

A method for post-treatment of exhaust gas exiting an internal combustion engine comprising an exhaust aftertreatment system (2) comprising a parallel coupled particle separator (3) according to any one of claims 1 to 13, wherein, in particular,

15 (10), the second particulate separator (3) is cleaned and for this purpose the exhaust gas and / or the compressed air flow is conducted through its purification ducts (11), thereby reducing or preventing the exhaust gas flow through the exhaust gas flow ducts (10).