EP2059660A1 - Filtre destiné à éliminer des particules d'un flux gazeux et procédé de fabrication associé - Google Patents

Filtre destiné à éliminer des particules d'un flux gazeux et procédé de fabrication associé

Info

Publication number
EP2059660A1
EP2059660A1 EP07787330A EP07787330A EP2059660A1 EP 2059660 A1 EP2059660 A1 EP 2059660A1 EP 07787330 A EP07787330 A EP 07787330A EP 07787330 A EP07787330 A EP 07787330A EP 2059660 A1 EP2059660 A1 EP 2059660A1
Authority
EP
European Patent Office
Prior art keywords
filter
protective layer
porous protective
coating material
coating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP07787330A
Other languages
German (de)
English (en)
Inventor
Bernd Reinsch
Christoph Osemann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP2059660A1 publication Critical patent/EP2059660A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/022—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous
    • F01N3/0222—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous the structure being monolithic, e.g. honeycombs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/202—Alkali metals
    • B01D2255/2022—Potassium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/204—Alkaline earth metals
    • B01D2255/2042—Barium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0244—Coatings comprising several layers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/06—Ceramic, e.g. monoliths
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the invention relates to a filter for removing particles from a gas stream according to the preamble of claim 1 and to a method for producing the filter.
  • Such filters are used, for example, in the exhaust aftertreatment of self-igniting internal combustion engines, in particular in diesel-powered motor vehicles.
  • filters for the removal of particles so-called particulate filter made of a ceramic material, for example silicon carbide, aluminum titanate or cordierite.
  • the particle filters are generally in the form of a honeycomb ceramic with mutually closed channels.
  • Such particle filters have a filtration efficiency of more than 80% to regularly greater than 90%.
  • the difficulty is not only in the filtration of soot particles but also in the regeneration of the filter.
  • fuel or its decomposition products are catalytically oxidized in an exhaust aftertreatment arrangement, which comprises the particle filter, in order to generate the temperatures necessary for the ignition of the soot.
  • the thermal stability of the filter is known for example from US-B 6,898,930.
  • the diesel particulate filter described in US Pat. No. 6,898,930 can be provided with a coating which contains a catalytically active material, for example a noble metal.
  • Ceramic filter materials generally have microcracks that contribute to the thermal stability of the filter. These are simply called “expansion joints” because they close due to thermal expansion of the material and thus reduce the thermally induced stresses of the filter component As the number of microcracks increases, the thermal expansion coefficient and thermal conductivity of the ceramic filter decreases one, the stabilizing effect can As a result, such ceramic filters, especially after high thermal stress, especially if they consist of the filter materials cordierite or aluminum titanate, have a higher probability of failure.
  • a catalyst is known from a ceramic material in which microcracks in the ceramic material are filled prior to the application of a coating with an organic substance, so that the coating can not penetrate into the microcracks. After application of the coating, the organic substance is removed by burning out. It is also known from US Pat. No. 4,451,517 to close microcracks in the ceramic with an organic substance in the case of a honeycomb catalyst before applying a coating of aluminum oxide. In this way, both US Pat. No. 4,532,228 and US Pat. No. 4,451,517 are intended to prevent coating material from penetrating into the microcracks.
  • An inventively designed filter for removing particles from a gas stream, in particular soot particles from an exhaust gas stream of an internal combustion engine comprising a filter body of a ceramic filter substrate, wherein the filter substrate is coated with a porous protective layer of a coating material.
  • the coating material contains an admixture of 1 to 20% by weight of at least one member of the second main group, preferably an oxide of an element of the second main group, and cracks contained in the ceramic filter substrate are partially filled by the coating material.
  • the protective layer Besides partially filling the cracks in the ceramic filter substrate, it is possible for the protective layer to be in the form of a thin film or a thin layer on the filter substrate.
  • the addition of the at least one compound of an element of the second main group increases the thermal resistance of the protective layer.
  • the coating material for the porous protective layer is preferably selected from the group consisting of aluminum oxide, aluminum hydroxide, titanium dioxide, silicon dioxide, zirconium dioxide, cerium oxide, aluminum silicates, magnesium aluminum silicates, cordierite, multilite, silicon carbide, aluminum titanate, zeolites, quartz, glasses and Mixtures thereof.
  • the coating material for the porous protective layer is preferably selected from the group consisting of aluminum oxide, aluminum hydroxide, titanium dioxide, silicon dioxide, zirconium dioxide, cerium oxide, mixtures and mixed oxides thereof.
  • mixed oxides of aluminum oxide and silicon oxide with a mass fraction of up to 15% by weight of silicon dioxide, based on aluminum oxide are suitable for use with zeolites rich in silicon or mixed oxides of cerium oxide and zirconium oxide.
  • the coating material for the porous protective layer further contains at least one alkali metal compound, preferably an alkali metal oxide for adjusting the morphology of the protective layer.
  • the proportion of the at least one alkali metal compound based on the coating material is preferably up to 0.5% by weight.
  • the coating material for the porous protective layer may further contain at least one compound of a third to fifth subgroup element or lanthanides including lanthanum, preferably an oxide of a third to fifth subgroup element or lanthanides including lanthanum.
  • the proportion of the compound of the element of the third to fifth subgroup or the lanthanides including the lanthanum preferably in the range up to 5 wt .-%.
  • Mixtures of the substances for the porous protective layer are possible in any ratio.
  • mixtures of aluminum oxide with up to 18% by weight of BaO, 0.03% by weight of K 2 O, 6% by weight of CeO 2 and 8% by weight of ZrO 2 are preferred.
  • At least one further protective layer is applied to the porous protective layer.
  • the porous protective layers can consist of the same or of different materials.
  • the individual porous protective layers can fulfill different functions.
  • two or more different porous protective layers are applied alternately one above the other.
  • at least one of the porous protective layers contains a catalytically active component.
  • the catalytically active component are preferably one or more metals from the group of platinum metals, preferably platinum, rhodium and / or palladium.
  • the catalytically active component can be contained in the porous protective layer, with which the ceramic filter substrate is coated or in one of the protective layers applied thereto. It is also possible, if only a porous protective layer is applied to the ceramic filter substrate, that this protective layer contains the catalytically active substance.
  • noxious gases such as unburned fuel
  • its decomposition products for example carbon monoxide, as well as nitrogen oxides, sulfur oxides and soot can be stored or converted catalytically.
  • the catalytic function is suitable to withstand the thermochemical attack of exhaust gas components.
  • the at least one catalytically active component is treated in a manner customary for the preparation of catalysts.
  • mixtures of a plurality of catalytically active substances in a porous protective layer or even a plurality of different catalytically active substances can be used on different porous protective layers.
  • the catalytically active substances preferably noble metals, may also be present as alloys or mixtures.
  • the porous protective layer is applied in the downstream and / or central region of the filter. Furthermore, it is also possible for individual regions of the filter substrate to be coated with different layers, amounts or layer sequences.
  • the porous protective layer is applied in the inflow-side region of the filter.
  • special applications allow or require application to radial edge areas of the filter.
  • the coating materials are preferably in the form of their oxides.
  • the coating materials are in the form of their nitrates, hydroxides, acetates, oxalates, carbonates or similar compounds. In general, however, these compounds decompose at least temporarily to oxides under the operating conditions of the filter. Furthermore, it is also possible that these compounds are temporarily formed from the oxides under the operating conditions of the filter.
  • the process according to the invention for producing a filter for removing particles from a gas stream comprises the following steps:
  • the coating material for forming the porous protective layer preferably has a BET surface area of more than 10 m 2 / g and a pore volume in the range of 0.1 to 1.5 ml / g in powder form.
  • the average particle size (D50) of the coating materials suitable for forming the protective layer varies widely. Particularly suitable are particles in the size of 2 nm to 20 microns. Especially suitable are particles with a size of more than 1 micron.
  • the particles suitable for coating can be obtained, for example, by precipitation processes or by pyrolytic processes. For adjusting the particle size and the particle size distribution, milling processes or precipitation processes are suitable, for example. Any other processes known to those skilled in the art for adjusting particle size and particle size distribution are also possible.
  • inorganic salt solutions and organometallic solutions can be used as precursors.
  • Suitable coatings are formed, for example, by combination of differently sized particles, sometimes with bimodal or polymodal particle size distribution.
  • the coating material for the porous protective layer is preferably applied in a sol-gel process, as a preformed sol or gel or as a suspension of solid particles.
  • the rheological properties of this coating composition and the particle size distribution are adjusted so that the coating composition is suitable for partially infilling the cracks in the ceramic filter substrate.
  • the application of the coating material for the porous protective layer can be carried out by all coating processes known to the person skilled in the art. Suitable coating processes are, for example, spraying, dipping, impregnating or the like. Furthermore, coating processes based on vacuum or pressure are also suitable.
  • aqueous solutions for example, aqueous solutions, hydrosols, hydrogels or aqueous suspensions
  • organosols, organogels or organic solutions or dispersions which have a lower surface tension than their aqueous homologs.
  • aqueous media whose surface tension has been reduced by inorganic or organic additives are also suitable.
  • Suitable additives are, for example, long-chain alcohols and surfactants.
  • the at least one compound of an element of the second main group or also optionally further substances contained in the protective layer for example, the at least one alkali metal compound, the compound of an element of the third to fifth subgroup or the lanthanides including the lanthanum or the catalytically active component, for example in the form of a solid, for example as an oxide,
  • Substances may be added to the raw material of the coating material, the coating composition or the finished coating.
  • the addition may be effected in any manner known to the person skilled in the art.
  • step (d) The fixing of the porous protective layer in step (d) is carried out by conventional methods known to the person skilled in the art. Suitable methods are, for example, drying, calcination and sintering.
  • the amount of coating materials to be applied to form the porous protective layer can be varied within wide limits.
  • the loading of the filter with the coating material is based on the filter volume and is 1 g / l to 200 g / l, preferably 10 to 150 g / l, based on the total filter volume.
  • FIG. 1 shows a schematic representation of an internal combustion engine with an exhaust gas aftertreatment device according to the invention
  • FIG. 2 shows a longitudinal section of a filter element according to the invention
  • FIG. 3 shows a schematic representation of the coated filter substrate with a layer
  • FIG. 4 shows an example of a grain of the filter substrate with a coating in several layers.
  • FIG. 1 shows a schematic representation of an internal combustion engine with an exhaust gas aftertreatment device according to the invention.
  • the exhaust aftertreatment device is here a filter in which soot particles are removed from the exhaust gas flow.
  • An internal combustion engine 10 is connected via an exhaust pipe 12, in which a filter device 14 is arranged.
  • the arrangement contains one or more catalysts 19, which are arranged in front of the filter device 14. With the filter device 14 soot particles are filtered out of the exhaust gas flowing in the exhaust pipe 12. This is especially necessary for diesel engines to comply with legal requirements.
  • the filter device 14 comprises a cylindrical housing 16, in which a rotationally symmetrical in the present embodiment, a total of cylindrical filter element 18 is arranged.
  • Figure 2 shows a filter element according to the invention in longitudinal section.
  • the filter element 18 is produced, for example, as an extruded shaped body made of a ceramic material, for example magnesium aluminum silicate, preferably cordierite.
  • the filter element 18 is traversed by exhaust gas in the direction of the arrows 20.
  • the exhaust gas occurs via an entrance surface 22 in the filter element 18 and leaves this via an exit surface 24th
  • inlet channels 28 Parallel to a longitudinal axis 26 of the filter element 18 extend a plurality of inlet channels 28 in alternation with outlet channels 30.
  • the inlet channels 28 are closed at the outlet surface 24.
  • sealing plugs 36 are provided for this purpose.
  • outlet channels 30 are open at the outlet surface 24 and closed in the region of the inlet surface 22.
  • the flow path of the unpurified exhaust gas thus leads into one of the inlet channels 28 and from there through a filter wall 38 into one of the outlet channels 30. This is illustrated by the arrows 32 by way of example.
  • FIG. 3 shows a schematic representation of the coated filter substrate with a layer.
  • a filter wall 38 is made of a ceramic filter substrate.
  • the ceramic filter substrate consists of individual grains 40, which are generally interconnected by sintering.
  • the ceramic filter substrate is preferably silicon carbide, aluminum titanate, mullite or cordierite. Also, mixtures of these materials are possible.
  • Between the individual grains 40 of the ceramic filter substrate are pores 42, which are flowed through by the gas stream to be cleaned. Particles contained in the gas stream are retained by the ceramic filter substrate of the filter wall 38.
  • the particles removed from the gas stream also settle in the pores 42. This reduces the free cross section of the filter wall 38 and the pressure loss across the filter wall 38 increases. For this reason, it is necessary to remove the particles from the pores at regular intervals. This is generally done by thermal regeneration by heating the filter to a temperature in excess of 600 ° C. At this temperature, the usually organic particles burn to carbon dioxide and water and are discharged from the particle filter in gaseous form.
  • Microcracks 44 are generally included in the individual grains.
  • the microcracks 44 contribute to the thermal stability of the filter. With a thermal expansion of material, the microcracks 44 close and thus reduce the thermally induced stresses in the filter wall 38.
  • the thermal expansion coefficient and the thermal conductivity of the ceramic filter 14 decrease.
  • the stabilizing effect may be limited since the microcracks 44 will not expand upon thermal expansion of the material can close more. This increases the thermally induced stresses in the grains. The occurring stresses can lead to rupture of the filter wall 38.
  • porous protective layer 46 In order to avoid the penetration of particles into the microcracks 44, these are partially filled with a porous protective layer 46.
  • the material for the porous protective layer is as already described above preferably selected from the group consisting of aluminum oxides, aluminum hydroxide, titanium dioxide, silicon dioxide, zirconium dioxide, cerium oxide, aluminum silicates, magnesium aluminum silicates, cordierite, mullite, silicon carbide, aluminum titanate, zeolites, Quartz, glasses, mixtures thereof and mixed oxides thereof.
  • the coating material is 1 to 20 wt .-% of at least one compound of an element of the second main group, preferably an oxide of an element of the second main group, admixed.
  • the porous protective layer may contain alkali metal compounds or compounds of an element of the third to fifth subgroups or the lanthanides including the lanthanum.
  • the coating material may also form a thin layer or film on the grains 40 of the filter substrate.
  • the ceramic coating may further contain at least one catalytically active material.
  • catalytically active material are noble metals from the group of platinum metals, for example platinum, rhodium or palladium.
  • the catalytically active material contained in the coating also stores noxious gases and soot particles and converts them thermally catalytically. The reaction of noxious gases is generally exothermic, releasing heat of reaction. This heat of reaction contributes to the achievement of the exhaust gas temperature necessary for the regeneration of the filter.
  • the rheological properties and optionally the particle sizes of the particles contained in the coating composition are preferably adjusted so that portions of the coating material can also penetrate into the microcracks 44.
  • the coating material is preferably applied in a sol-gel process, as a performed sol or gel or as a suspension of solid particles.
  • FIG. 4 shows a grain 40 of the filter substrate with a coating of two layers.
  • a micro-crack 44 is formed in the grain 40.
  • the grain 40 shown here comprises a first protective layer 48 consisting of a coating material as described above.
  • the coating material 48 also partially contains the microcrack 44 contained in the grain 40.
  • Both the microcrack 44 and a branch 50 of the microcrack 44 include an unfilled region 52 that was not filled by the coating material.
  • the grain 40 is completely covered by the first layer 48.
  • the first layer 48 which has also partially filled the microcrack 44, increases the thermal and hydrothermal stability of the grain 40.
  • a second layer 54 is applied to the first layer 48.
  • the second layer 54 also consists essentially of a ceramic or mineral oxide, as described above.
  • the first layer 48 or the second layer 54 contain a catalytically active material.
  • the first layer 48 and the second layer 54 may also both contain the catalytically active material.
  • it is possible for the first layer 48 and the second layer 54 to consist of the same coating material. However, also the first layer 48 and the second layer 54 may be made of different coating materials.
  • At least one further porous protective layer is applied to the second layer 54.
  • protective layers of two different coating materials are each applied alternately to the grain 40.
  • each protective layer has a different composition or consists of a different coating material.
  • the protective layers are all made of the same material or have the same composition. The number of layers applied to the grain 40 is arbitrary and is limited only by the desired pore size remaining after coating.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Toxicology (AREA)
  • Catalysts (AREA)
  • Filtering Materials (AREA)

Abstract

L'invention concerne un filtre destiné à éliminer des particules d'un flux gazeux, en particulier des particules de suies d'un flux de gaz d'échappement provenant d'un moteur à combustion interne. Ledit filtre comprend un corps de filtre constitué d'un substrat de filtration en céramique, lequel est recouvert d'une couche protectrice poreuse (46, 48) constituée d'un matériau de revêtement. L'invention est caractérisée en ce qu'un composé d'un élément du deuxième groupe principal de la table périodique, de préférence un oxyde d'un élément du deuxième groupe principal, est ajouté au matériau de revêtement à raison de 1 à 20% en poids, et en ce que les fissures (44) du substrat de filtration en céramique sont partiellement comblées par le matériau de revêtement. L'invention concerne également un procédé permettant la fabrication d'un filtre, selon lequel le matériau de revêtement utilisé pour la couche protectrice poreuse (46, 48) est appliqué sur le substrat de filtration en céramique fritté, au moins un composé d'un élément du deuxième groupe principal est ajouté, d'autres substances contenues dans la couche protectrice (46, 48) sont ajoutées éventuellement et la couche protectrice poreuse (46, 48) est fixée.
EP07787330A 2006-08-31 2007-07-10 Filtre destiné à éliminer des particules d'un flux gazeux et procédé de fabrication associé Withdrawn EP2059660A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102006040739A DE102006040739A1 (de) 2006-08-31 2006-08-31 Filter zur Entfernung von Partikeln aus einem Gasstrom sowie Verfahren zu seiner Herstellung
PCT/EP2007/057056 WO2008025603A1 (fr) 2006-08-31 2007-07-10 Filtre destiné à éliminer des particules d'un flux gazeux et procédé de fabrication associé

Publications (1)

Publication Number Publication Date
EP2059660A1 true EP2059660A1 (fr) 2009-05-20

Family

ID=38472942

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07787330A Withdrawn EP2059660A1 (fr) 2006-08-31 2007-07-10 Filtre destiné à éliminer des particules d'un flux gazeux et procédé de fabrication associé

Country Status (5)

Country Link
US (1) US20110091361A1 (fr)
EP (1) EP2059660A1 (fr)
KR (1) KR20090056999A (fr)
DE (1) DE102006040739A1 (fr)
WO (1) WO2008025603A1 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5689685B2 (ja) 2008-02-05 2015-03-25 ビーエーエスエフ コーポレーション 微粒子トラップを有するガソリンエンジン排出ガス処理システム
DE202008007223U1 (de) 2008-05-29 2009-10-08 Mann+Hummel Gmbh Filtereinrichtung zur Entfernung von Partikeln aus einem Gasstrom
DE202008007224U1 (de) 2008-05-29 2009-10-29 Mann+Hummel Gmbh Filtereinrichtung zur Entfernung von Partikeln aus einem Gasstrom
EP2974779A1 (fr) * 2008-11-04 2016-01-20 Umicore AG & Co. KG Filtre a particules diesel dote de proprietes de pression dynamique ameliorees
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KR20090056999A (ko) 2009-06-03
DE102006040739A1 (de) 2008-03-06
US20110091361A1 (en) 2011-04-21

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