EP1957184A1 - Diffuseur pour systemes d'épuration de gaz d'échappement - Google Patents
Diffuseur pour systemes d'épuration de gaz d'échappementInfo
- Publication number
- EP1957184A1 EP1957184A1 EP06817731A EP06817731A EP1957184A1 EP 1957184 A1 EP1957184 A1 EP 1957184A1 EP 06817731 A EP06817731 A EP 06817731A EP 06817731 A EP06817731 A EP 06817731A EP 1957184 A1 EP1957184 A1 EP 1957184A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- diffuser
- exhaust gas
- flow
- gas purification
- ceramic
- 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.)
- Ceased
Links
- 238000004140 cleaning Methods 0.000 title abstract description 4
- 239000000919 ceramic Substances 0.000 claims abstract description 47
- 229920005830 Polyurethane Foam Polymers 0.000 claims abstract description 8
- 239000011496 polyurethane foam Substances 0.000 claims abstract description 8
- 239000000463 material Substances 0.000 claims abstract description 7
- 239000007789 gas Substances 0.000 claims description 71
- 239000002245 particle Substances 0.000 claims description 25
- 239000003054 catalyst Substances 0.000 claims description 22
- 239000006260 foam Substances 0.000 claims description 21
- 238000000746 purification Methods 0.000 claims description 14
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 239000011149 active material Substances 0.000 claims description 3
- 238000009792 diffusion process Methods 0.000 claims description 3
- 239000010970 precious metal Substances 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 2
- 238000007254 oxidation reaction Methods 0.000 claims description 2
- 238000007654 immersion Methods 0.000 claims 1
- 230000003197 catalytic effect Effects 0.000 abstract description 25
- 238000009826 distribution Methods 0.000 abstract description 14
- 229910000510 noble metal Inorganic materials 0.000 abstract description 6
- 239000000376 reactant Substances 0.000 abstract description 6
- 238000002485 combustion reaction Methods 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract 1
- 241001631457 Cannula Species 0.000 description 10
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 6
- 239000003344 environmental pollutant Substances 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 231100000719 pollutant Toxicity 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- 229910002091 carbon monoxide Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000011068 loading method Methods 0.000 description 4
- 241000264877 Hippospongia communis Species 0.000 description 3
- 241000243142 Porifera Species 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 230000008929 regeneration Effects 0.000 description 3
- 238000011069 regeneration method Methods 0.000 description 3
- 229910052703 rhodium Inorganic materials 0.000 description 3
- 239000010948 rhodium Substances 0.000 description 3
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 239000004202 carbamide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000013598 vector Substances 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000009969 flowable effect Effects 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
-
- 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
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/9454—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
-
- 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
- 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
- B01J37/0215—Coating
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
- C04B38/0615—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances the burned-out substance being a monolitic element having approximately the same dimensions as the final article, e.g. a porous polyurethane sheet or a prepreg obtained by bonding together resin particles
-
- 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
- F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
- F01N3/2825—Ceramics
-
- 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
- F01N3/2892—Exhaust flow directors or the like, e.g. upstream of catalytic device
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
- F15D1/00—Influencing flow of fluids
- F15D1/001—Flow of fluid from conduits such as pipes, sleeves, tubes, with equal distribution of fluid flow over the evacuation surface
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
- B01D2255/402—Perovskites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/908—O2-storage component incorporated in the catalyst
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/92—Dimensions
- B01D2255/9207—Specific surface
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00793—Uses not provided for elsewhere in C04B2111/00 as filters or diaphragms
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/0081—Uses not provided for elsewhere in C04B2111/00 as catalysts or catalyst carriers
-
- 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
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/20—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a flow director or deflector
-
- 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 diffuser with or without catalytic activity, which is suitable for use in exhaust gas purification systems of engines, with diesel engines, gasoline and gas engines in vehicles as well as stationary engines.
- a large active surface This consists of a ceramic or metallic carrier body, which can be coated with aluminum oxide, for example, to enlarge the surface.
- this surface can be coated with precious metals such as platinum, palladium or rhodium or perovskites.
- Such catalytic effects serve the purpose of generating harmless nitrogen (N 2 ) or reactive nitrogen dioxide (NO 2 ) from the nitrogen oxides (NO x ), converting carbon monoxide (CO) into carbon dioxide (CO 2 ) and from unburned or partially burned hydrocarbons ( HC) to produce carbon dioxide (CO 2 ) and water (H 2 O).
- Liquid or solid reactants for example ammonia solutions, urea solutions or fuel, are sometimes added to the exhaust gas in order to produce chemical reactions in the catalysts or to increase the temperatures.
- the invention has for its object to provide a diffuser as the active surface, by means of which on this first treatment unit, the exhaust gas stream, optionally including metered reactants is fanned out as homogeneously as possible.
- downstream exhaust gas treatment systems such as particle filters or catalysts are subjected to a homogeneous flow across the entire cross-section and in the composition of the exhaust gas, and secondly - in the case of a catalytically coated diffuser - the catalytically active surface in the diffuser itself is used as much as possible.
- the diffuser should be designed so that it generates as little flow resistance as possible. Furthermore, this diffuser should take into account the fact that the entire exhaust gas aftertreatment unit can be made compact, both with regard to limited space and with regard to cheap manufacture and handling in series production.
- the incoming exhaust gas flows into an extruded ceramic body which, for example, has a honeycomb or grid-like cross section, the individual honeycombs forming very thin cannulas running parallel to one another, through which the gas is passed.
- the cannula walls are coated, for example, with aluminum oxide and noble metals or perovskites.
- the exhaust gas comes into contact with the cannula walls as it flows through, which, due to their specific coating, leads to catalytic reactions.
- the overall cross section of this ceramic body must be dimensioned significantly larger than that of the exhaust pipe.
- the exhaust gas flow must first be fanned out from the diameter of the exhaust pipe and only then can the full cross-section flow in and through the ceramic body.
- the central area of the ceramic body and the cannulas located there Because of the speed distribution of the gas flow over the exhaust pipe cross-section, the flow flows more strongly than the edge regions of the ceramic body. In some cases, the fanning out is off-center, so that the area with more flow is also off-center. In such cases, the flow away from the peripheral areas is even weaker.
- the particle filter adjoining the catalytic ceramic body shows a similar structure consisting of fine cannulas arranged parallel to one another, the one being closed at the front like a chessboard and the adjacent one at the rear.
- the gas flows into the cannulas, which are open at the front, and must then forcibly diffuse through the porous cannula walls into the neighboring cannulas, from which it emerges on the rear side of the particle filter and into an exhaust tailpipe.
- the solids in the form of soot particles collected in the particle filter are burned off periodically or continuously, which regenerates the filter. Similar flow situations prevail in catalysts, for example in oxidation, 3-way or DeNOx catalysts, but without mutually closed cannulas.
- gaseous, liquid or solid reactants metered into the exhaust gas for example ammonia or urea solutions or fuel
- gaseous, liquid or solid reactants metered into the exhaust gas cannot mix homogeneously in the exhaust gas stream, for example in the case of short mixing distances or due to inertial forces, which leads to locally different concentrations of the reactant and thus to non-optimal ones Systems leads.
- the present invention thus wants to create a flow body which homogenizes an inhomogeneous speed distribution and inhomogeneous composition of the exhaust gas stream, and which can also be carried out catalytically effective in a special embodiment.
- the gas flow and the composition of the metered reactants should thus be distributed more homogeneously over the flow cross section. This is to ensure that downstream particle filters or catalysts are flowed towards as far as possible by a gas stream with a homogeneous velocity distribution and a homogeneous composition.
- This flow body should be inexpensive to manufacture and have the largest possible active area for the gas flowing through.
- a diffuser for exhaust gas purification systems consisting of a foam or sponge-like or three-dimensional lattice-like, macroscopically flowable ceramic structure in all directions.
- the diffuser can be catalytically coated and is then catalytically active or else it is not catalytically active if it is not particularly coated.
- Figure 1 is a schematic representation of a conventional structure of a
- Exhaust gas purification system with a catalytic flow body with a honeycomb cross section and a downstream particle filter;
- Figure 2 is a schematic representation of the structure of an exhaust gas purification system with a diffuser of the present invention in the form of a flow body made of a ceramicized polyurethane foam and a downstream particle filter.
- Another aspect is the mixing and swirling of the gases, especially at right angles to the flow axis, which should be caused by the flow. rather structures arise.
- This result is important for the intimate mixing of pollutants in the exhaust gas before it reaches catalytic converters and collectors or particle filters, where the particles are retained and / or chemical reactions take place. Only with well-mixed exhaust gases can it be ensured that the catalyst and collector surfaces are evenly loaded. It has been shown that these ceramic structures, which are porous in all directions, generate strong turbulence in the gases after they have emerged from the structures. This leads to the conclusion that the turbulence is even more pronounced inside the structures. The turbulence is strongest directly at the exit from the structure and then, as expected, weakens continuously in the free flow channel.
- the strong turbulence inside the structure is very conducive to efficient interaction with the catalytic surface of the structure. Accordingly, the rate of the converted pollutants when flowing through such a catalytic structural body is significantly increased compared to the flow through a channel catalyst. This is particularly important when you consider that the flow through a regular monolithic body like the previous ceramic flow bodies is largely laminar, with a low Reynolds number. With this dimensionless number, the kinetic energy density is compared with the friction loss density.
- the velocity gradient transverse to the direction of flow is estimated by the typical value of the velocity and the characteristic length or dimension of the system, for example the diameter of a flow tube.
- the Reynolds number is therefore a stability criterion for laminar flows.
- the gas flow in a ceramic, foam or sponge-like flow body that is porous in all directions is considerably more turbulent than that in a monolithic flow body with straight flow channels,
- a catalytically active that is, a catalytically coated or even just a catalytically inactive, that is, a catalytically uncoated diffuser for exhaust gas purification systems, which consists of such a foam or sponge-like porous ceramic structure
- a catalytically uncoated diffuser for exhaust gas purification systems which consists of such a foam or sponge-like porous ceramic structure
- open-cell foam or sponge ceramics are produced, for example, by the Schwartzwalder process, described in US Pat. No. 3O90O94 the year 1963.
- recirculated polymer foams are impregnated with a ceramic suspension and pressed out using squeeze rollers or similar methods, and the molded parts are then dried.
- the pore size of the foam ceramic is determined by the polymer foam and is, for example, between 5 and 50 ppi, which corresponds to approximately 5000 to 500 ⁇ m.
- the subsequent temperature treatment of the polymer foam is thermally degraded at a temperature of for example 300-600 0 C.
- the sintering temperature depending on the material being between 1000-2200 0 C.
- One or more post-infiltrations and by coating the porous ceramic body can significantly increase its strength. It is also possible to infiltrate or coat the ceramic foam with a catalytically active material and to subject this layer to a temperature treatment. In professional circles, one speaks regularly of ceramic foams, although these are permeable on all sides and therefore resemble a sponge structure rather than a foam structure.
- FIG. 1 shows a schematic representation of a catalyst 1 with a particle filter 2, installed in an exhaust pipe 3 of an internal combustion engine. It is housed in a muffler 4, which has a larger diameter than the supplying exhaust pipe 3. In the first area of the muffler 4, the catalytic converter 1 is arranged, to which the particle filter 2 connects.
- the task of the catalytic converter 1 is to convert the incoming pollutants permanently in the smallest possible space with the lowest possible pressure drop. The pollutants react chemically on the catalyst surface.
- an extruded ceramic body has been used for this purpose, which has been coated with a catalytically active noble metal in a single- or multi-layer process to enlarge its surface, for example with aluminum oxide.
- Such an extruded catalyst body consists of a very large number of parallel, adjacent and straight flow channels 5.
- the inner wall of each flow channel 5 forms the surface with which the pollutant molecules flowing through have a catalytic effect can. Gas which has once flowed into the catalyst body is trapped in the fine flow channels 5 and can only flow along these channels 5. Cross flows are not possible.
- a speed distribution in front of the catalyst 1 has a corresponding effect.
- a typical distribution curve is drawn qualitatively in the exhaust pipe 1 with a few speed vectors.
- the direct flow area of the catalyst 1 is therefore always acted upon by gas molecules at a much greater speed than the outer areas.
- the edges of the catalyst body are flowed through much weaker.
- a typical distribution curve of the axial velocities is plotted qualitatively above the catalytic converter 1, the velocities being plotted as vectors. Therefore, the different surfaces of this catalyst 1 are inevitably exposed to gas molecules in very different ways: where the flow rates are high, more gas molecules pass by each time and can react catalytically with the catalyst surface there.
- the catalytic effect will therefore decrease more rapidly in the central area due to aging than in the peripheral areas, and if the catalyst 1 is deemed to be used, the peripheral areas are still intact.
- the gases experience only slight turbulence inside the catalytic converter 1, so the superimposed axial speed is changed only slightly.
- Behind the catalytic converter 1, too a distribution curve of the speeds is measured at speeds much higher in the center than towards the edge of the muffler 4.
- This markedly inhomogeneous speed distribution which is also shown qualitatively, has a disadvantageous effect on the operation of downstream exhaust gas aftertreatment systems, such as, for example, particle filters or other catalysts 2.
- These treatment systems generally consist of a multiplicity of porous flow channels 6, 7 lying next to one another, with the particle filter 2 alternately half 6 of these channels 6, 7 being closed at the rear in a checkerboard manner and the other half 7 at the front of the particle filter 2 being closed in a checkerboard manner.
- all of the flow channels 6 that are exposed to flow and open at the front act like pockets.
- the gases must diffuse through the porous walls of these pockets into the adjacent flow channels 7, so that the gases then inevitably emerge from the rear emerge from the open ends of these flow channels 7 and are expelled through the exhaust pipe into the open. If, for example, the gases hit the inlet cross-section of the particle filter 2 at very different speeds, i.e.
- This ceramic structure therefore works excellently as a diffuser and releases the flowing gases evenly over the entire muffler cross-section in downstream exhaust gas aftertreatment systems such as catalytic converters, DeNox systems or particle filters 2.
- exhaust gas aftertreatment systems such as catalytic converters, DeNox systems or particle filters 2.
- this is, for example, in a dipping process with one or more surface-enlarging, oxygen-storing and / or catalytically active Coated materials.
- such a foam-like or sponge-like or three-dimensional lattice-like ceramic structure 8 that can be flowed through macroscopically in all directions can be produced, for example, by immersing a polyurethane foam in a ceramic slip. The polyurethane foam coming out of the ceramic slip and soaked with ceramic is then dried and afterwards the polyurethane foam is burned out of the resulting structure. What remains is a three-dimensional foam or sponge-like or lattice to net-like structural body. In the macroscopic sense, a gas can flow through it in every direction. This hard structural body can be coated with catalytically active material at the same time or subsequently in a further process.
- this coating can contain surface-enlarging and / or oxygen-storing materials as well as noble metals or perovskite materials. Platinum, palladium and rhodium are suitable as precious metals for the treatment of exhaust gases from internal combustion engines.
- a ceramic body produced and coated in this way can be produced in any geometrical shape by previously producing the polyurethane foam in the desired geometric shape or by cutting it into such a shape that it replaces the previous ceramic body as a diffuser and at the same time as a catalyst in an exhaust pipe or can be installed in the exhaust pipe of an exhaust pipe.
- catalytically coated or non-coated versions brings about a homogeneous fanning out of the incoming inhomogeneous exhaust gas stream during operation and, in the case of catalytically coated versions, treats the same catalytically particularly uniformly at the same time.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Health & Medical Sciences (AREA)
- Mechanical Engineering (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- General Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Toxicology (AREA)
- Biomedical Technology (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Structural Engineering (AREA)
- Exhaust Gas After Treatment (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
L'invention concerne un diffuseur catalytiquement actif ou non qui convient pour des systèmes d'épuration de gaz d'échappement de moteurs à combustion interne. Il est constitué d'une structure (8) en céramique formée à partir d'une mousse de polyuréthane céramisée. Cette structure (8) en céramique peut être revêtue de matériaux et/ou de métaux précieux qui augmentent sa surface et/ou retiennent l'oxygène pour exercer un effet catalytique sur les molécules de gaz qui le traversent. Comme l'intérieur du diffuseur est poreux dans toutes les directions, un gaz et sa pression peuvent se propager de manière identique de tous les côtés dans la totalité du volume du diffuseur. On obtient une répartition presque homogène des vitesses sur toute la section transversale d'écoulement et on crée une turbulence accrue qui entraîne une multiplication des contacts des molécules nocives avec les parois. En même temps, les systèmes raccordés en aval sont alimentés et traversés sur toute leur section transversale de manière régulière, par un gaz d'échappement mélangé de manière homogène et éventuellement des agents réactifs ajoutés. Globalement, ce diffuseur permet de réaliser de manière plus économique et plus compacte un système d'épuration de gaz d'échappement de même rendement.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH19192005 | 2005-12-05 | ||
PCT/CH2006/000679 WO2007065284A1 (fr) | 2005-12-05 | 2006-12-01 | Diffuseur pour systemes d'épuration de gaz d'échappement |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1957184A1 true EP1957184A1 (fr) | 2008-08-20 |
Family
ID=36588960
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP06817731A Ceased EP1957184A1 (fr) | 2005-12-05 | 2006-12-01 | Diffuseur pour systemes d'épuration de gaz d'échappement |
Country Status (3)
Country | Link |
---|---|
US (1) | US20090139400A1 (fr) |
EP (1) | EP1957184A1 (fr) |
WO (1) | WO2007065284A1 (fr) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE202006007876U1 (de) * | 2006-05-15 | 2007-09-20 | Bauer Technologies Gmbh | Optimierung von zellulären Strukturen, insbesondere für die Abgasreinigung von Verbrennungsaggregaten und andere Anwendungsbereiche |
US8377175B2 (en) | 2010-02-26 | 2013-02-19 | Arcelormittal Investigacion Y Desarrollo, S.L. | Apparatus and method for treating exhaust gas |
US20120115709A1 (en) * | 2010-11-09 | 2012-05-10 | Sienna Technologies, Inc. | High Temperature Catalysts for Decomposition of Liquid Monopropellants and Methods for Producing the Same |
US9855548B2 (en) | 2010-11-09 | 2018-01-02 | Sienna Technologies, Inc. | High temperature catalysts for decomposition of liquid monopropellants and methods for producing the same |
FR3041631B1 (fr) * | 2015-09-24 | 2022-01-07 | Snecma | Materiau poreux en ceramique pour revetement d'une piece et procede de fabrication de ce materiau |
JP2017180326A (ja) * | 2016-03-30 | 2017-10-05 | イビデン株式会社 | 拡散部材、排ガス浄化装置及び排ガス浄化装置における拡散部材の使用 |
CA3045040C (fr) * | 2016-12-21 | 2022-04-26 | Exxonmobil Upstream Research Company | Structures autoportantes a geometrie alveolaire et a materiaux actifs |
DE102018213276A1 (de) * | 2018-08-08 | 2020-02-13 | Contitech Mgw Gmbh | Vorrichtung zum Regeln des Dralls eines in einer Rohrleitung fließenden Fluids |
CN110193326A (zh) * | 2019-05-20 | 2019-09-03 | 陕西金泰氯碱化工有限公司 | 一种用于无汞催化合成氯乙烯优化反应控制的透气构件 |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3090094A (en) | 1961-02-21 | 1963-05-21 | Gen Motors Corp | Method of making porous ceramic articles |
US4404007A (en) | 1980-12-11 | 1983-09-13 | Nippon Soken, Inc. | Exhaust gas cleaning element |
JPS60255126A (ja) * | 1984-05-31 | 1985-12-16 | Nippon Denso Co Ltd | 多孔質セラミツクス構造体 |
EP0260826B1 (fr) * | 1986-09-10 | 1990-10-03 | Imperial Chemical Industries Plc | Catalyseurs |
US5177961A (en) | 1991-06-26 | 1993-01-12 | W. R. Grace & Co.-Conn. | Upstream collimator for electrically heatable catalytic converter |
JPH06254413A (ja) * | 1993-03-01 | 1994-09-13 | Ngk Insulators Ltd | 乱流穴を有するハニカム体 |
FR2717223B1 (fr) * | 1994-03-08 | 1996-04-19 | Renault | Dispositif d'échappement pour moteur à combustion interne. |
DE19704147A1 (de) * | 1997-02-04 | 1998-08-06 | Emitec Emissionstechnologie | Hitzebeständiger und regenerierbarer Filterkörper mit Strömungswegen |
DE19710264A1 (de) | 1997-03-13 | 1998-09-17 | Frank Drache | Verfahren zur Herstellung von beschichteten Keramiken mit erhöhter Mikroporosität, beschichtete Keramiken mit erhöhter Mikroporosität sowie daraus hergestellter Gegenstand |
JP2001221038A (ja) * | 1999-12-13 | 2001-08-17 | Ford Global Technol Inc | 消音形排気コンバーター |
US6669913B1 (en) * | 2000-03-09 | 2003-12-30 | Fleetguard, Inc. | Combination catalytic converter and filter |
JP4889873B2 (ja) * | 2000-09-08 | 2012-03-07 | 日産自動車株式会社 | 排気ガス浄化システム、これに用いる排気ガス浄化触媒及び排気浄化方法 |
US6946013B2 (en) * | 2002-10-28 | 2005-09-20 | Geo2 Technologies, Inc. | Ceramic exhaust filter |
JP4369141B2 (ja) * | 2003-02-18 | 2009-11-18 | 日本碍子株式会社 | ハニカムフィルタ及び排ガス浄化システム |
US20050252177A1 (en) * | 2004-05-12 | 2005-11-17 | Shiro Ishikawa | Ceramic filter and smoke treatment device |
-
2006
- 2006-12-01 WO PCT/CH2006/000679 patent/WO2007065284A1/fr active Application Filing
- 2006-12-01 US US12/085,981 patent/US20090139400A1/en not_active Abandoned
- 2006-12-01 EP EP06817731A patent/EP1957184A1/fr not_active Ceased
Non-Patent Citations (1)
Title |
---|
See references of WO2007065284A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2007065284A1 (fr) | 2007-06-14 |
US20090139400A1 (en) | 2009-06-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1957184A1 (fr) | Diffuseur pour systemes d'épuration de gaz d'échappement | |
EP1567247B1 (fr) | Piege a particules muni d'une couche de fibres enduite | |
DE102010051659B4 (de) | Verfahren zur Entfernung von Partikelmaterial aus einem Abgasstrom | |
DE102010009449B4 (de) | Wabenfilter | |
EP1583891A1 (fr) | Unite de retraitement des gaz d'echappement peu encombrante et pourvue de zones d'ecoulement aller-retour imbriquees avec une entree et une sortie de gaz du meme cote | |
EP1885473A1 (fr) | Procede et dispositif pour traiter les gaz d'echappement de moteurs a combustion interne | |
DE102017002809B4 (de) | Wabenstruktur | |
EP2923047A1 (fr) | Dispositif de post-traitement des gaz d'échappement à réduction catalytique sélective et véhicule automobile pourvu d'un tel dispositif | |
EP1837497B1 (fr) | Système de purification de gaz d'échappement comprenant un piège à polluants et un filtre à particules ainsi qu'un procédé de fabrication d'un tel système | |
DE102014013893A1 (de) | Mit Katalysator beladener Wabenfilter | |
DE102010055147A1 (de) | Vier-Wege-Katalysator, seine Verwendung sowie Fahrzeug mit einem solchen | |
DE10048511A1 (de) | Verfahren zur Verminderung von Kohlenmonoxid, Kohlenwasserstoffen und Partikel im mageren Abgas von Verbrennungsmotoren | |
DE60313151T2 (de) | Behandlung von abgasen aus einem verbrennungsmotor | |
DE102004024685A1 (de) | Katalysator-Trägerkörper für einen motornah einzusetzenden katalytischen Konverter | |
EP2382041B1 (fr) | Catalyseur d'oxydation diesel exempt de vanadium, et son procédé de production | |
DE60212245T2 (de) | Verfahren und Vorrichtung zum Entfernen von Russpartikeln aus dem Abgas eines Dieselmotors | |
EP3879084A1 (fr) | Système de traitement des gaz d'échappement pour une installation de gaz d'échappement d'un moteur à combustion interne et procédé de fonctionnement d'un tel système de traitement des gaz d'échappement | |
DE19961483B4 (de) | Reinigungskatalysator für das Abgas eines Verbrennungsmotors | |
DE102008003044B4 (de) | Abgasreinigungssystem zur verbesserten Abgasreinigung durch konvektives Mischen | |
EP2659950B1 (fr) | Système de traitement postérieur de gaz d'échappement | |
AT504391B1 (de) | Kombiniertes abgasreinigungssystem | |
EP1431528B1 (fr) | Dispositif de purification des gaz d'échappement | |
DE102013207922B4 (de) | Verfahren zur Behandlung eines Abgasstroms mit einem Silber-gestützten enggekoppelten NOx-Absorber | |
WO2018149627A1 (fr) | Filtres à particules comprenant des alvéoles d'accumulation de catalyseur | |
DE102021107130B4 (de) | Vorrichtung zur Erhöhung der Frischfiltration von Benzinpartikelfiltern |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20080528 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR |
|
17Q | First examination report despatched |
Effective date: 20100616 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R003 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED |
|
18R | Application refused |
Effective date: 20110630 |