EP0393257A1 - Diesel soot filter with an additional arrangement for the reduction of nitrogen oxides and/or the oxidation of carbon monoxide - Google Patents

Diesel soot filter with an additional arrangement for the reduction of nitrogen oxides and/or the oxidation of carbon monoxide Download PDF

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Publication number
EP0393257A1
EP0393257A1 EP89201062A EP89201062A EP0393257A1 EP 0393257 A1 EP0393257 A1 EP 0393257A1 EP 89201062 A EP89201062 A EP 89201062A EP 89201062 A EP89201062 A EP 89201062A EP 0393257 A1 EP0393257 A1 EP 0393257A1
Authority
EP
European Patent Office
Prior art keywords
soot filter
filter according
honeycomb bodies
diesel soot
diesel
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Withdrawn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
EP89201062A
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German (de)
French (fr)
Inventor
Rolf Dipl.-Ing. Brück
Hans-Jürgen Dipl.-Phys. Breuer
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.)
Vitesco Technologies Lohmar Verwaltungs GmbH
Original Assignee
Emitec Gesellschaft fuer Emissionstechnologie mbH
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Filing date
Publication date
Application filed by Emitec Gesellschaft fuer Emissionstechnologie mbH filed Critical Emitec Gesellschaft fuer Emissionstechnologie mbH
Priority to EP89201062A priority Critical patent/EP0393257A1/en
Publication of EP0393257A1 publication Critical patent/EP0393257A1/en
Withdrawn legal-status Critical Current

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    • 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
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F01N13/0097—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series the purifying devices are arranged in a single housing
    • 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
    • F01N3/023—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 using means for regenerating the filters, e.g. by burning trapped 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
    • F01N3/02—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
    • F01N3/023—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 using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/027—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 using means for regenerating the filters, e.g. by burning trapped particles using electric or magnetic heating means
    • 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
    • F01N3/2807—Metal other than sintered metal
    • F01N3/281—Metallic honeycomb monoliths made of stacked or rolled sheets, foils or plates
    • 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
    • F01N3/2807—Metal other than sintered metal
    • F01N3/281—Metallic honeycomb monoliths made of stacked or rolled sheets, foils or plates
    • F01N3/2821—Metallic honeycomb monoliths made of stacked or rolled sheets, foils or plates the support being provided with means to enhance the mixing process inside the converter, e.g. sheets, plates or foils with protrusions or projections to create turbulence
    • 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
    • F01N3/2828—Ceramic multi-channel monoliths, 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
    • F01N3/2882—Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices
    • 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
    • F01N3/2882—Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices
    • F01N3/2885—Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices with exhaust silencers in a single housing
    • 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
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/084—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling the gases flowing through the silencer two or more times longitudinally in opposite directions, e.g. using parallel or concentric tubes
    • 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
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/14—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having thermal insulation
    • 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
    • F01N2230/00—Combination of silencers and other devices
    • F01N2230/02—Exhaust filters
    • 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
    • F01N2230/00—Combination of silencers and other devices
    • F01N2230/04—Catalytic converters
    • 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
    • F01N2250/00—Combinations of different methods of purification
    • F01N2250/02—Combinations of different methods of purification filtering and catalytic conversion
    • 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
    • F01N2330/02—Metallic plates or honeycombs, e.g. superposed or rolled-up corrugated or otherwise deformed sheet metal
    • 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
    • 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
    • F01N2510/00—Surface coverings
    • F01N2510/06—Surface coverings for exhaust purification, e.g. catalytic reaction
    • 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
    • F01N3/30—Arrangements for supply of additional air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • the present invention relates to a diesel soot filter, that is to say a device in the exhaust duct of self-igniting internal combustion engines, which is suitable for retaining the soot particles which are entrained in the exhaust gas as a result of imperfect combustion of the fuel and to which harmful effects are attributed when they enter the atmosphere and thus get into the air.
  • a reduction in soot emissions by about 2/3 can be achieved with honeycomb filters, which are usually made of a ceramic material.
  • honeycomb filters which are usually made of a ceramic material.
  • the retained soot particles clog the channels in the honeycomb body within a comparatively short time to such an extent that the performance of the machine is reduced as a result of the pressure loss which then occurs, or the fuel consumption is significantly increased while the power output remains the same.
  • the soot particles accumulated in the filter must therefore be removed at regular intervals by oxidation, ie combustion.
  • the ignition temperature of the soot is above the usually reached exhaust gas temperature in the range of 540 ° C, which is why an additional heat supply is required to achieve this.
  • the electric heating is preferable for safety and procedural reasons, but because of the poor efficiency of the power generation by the generator driven by the machine itself, it is worth mentioning Increased consumption of fuel.
  • the heating power required can be reduced according to the suggestions made there if the ignition temperature of the soot can be reduced by the addition of catalytically active substances in the fuel.
  • From DE-A 37 11 101 the proposal is known to obtain the heat supply required to reach the ignition temperature from the oxidation of further substances which are inevitably entrained in the exhaust gas, such as carbon monoxide and hydrocarbons; this oxidation takes place catalytically on the surface of honeycomb bodies of the type described, for example provided with a platinum coating, as are also used to reduce the proportion of pollutants in the exhaust gases of gasoline engines.
  • the cited document also teaches to preheat the additional air blown in to provide the oxygen required for the oxidation by being conducted in heat exchange with the exhaust gases.
  • the object of the present invention is a diesel soot filter of the type described, in which the retained soot particles are optionally intermittently oxidized even when the diesel engine is only operated at partial load, the exhaust gas temperature regularly being below the ignition temperature of the soot; this is also the case if it (according to the proposal known from EP-A-0 077 524) has been reduced catalytically (e.g. also by contacting a correspondingly effective surface of the filter) to values around 350 ° C.
  • the energy requirement for any additional heating that may become necessary should be minimized and an embodiment of the filter proposed that is particularly suitable for supporting the course of the various chemical processes.
  • the diesel particulate filter consists of a plurality of first and second honeycomb bodies, which are alternately arranged one behind the other in the exhaust gas channel and provided with throughflow channels, of which the first honeycomb bodies are provided with a first surface layer, which in itself in a known manner catalytically causes the conversion of nitrogen oxides and carbon monoxide to nitrogen or carbon dioxide, while the second honeycomb bodies are provided with a second surface layer which, in a manner known per se, catalytically reduces the ignition temperature of the soot adhering to it.
  • the reactions taking place in the first honeycomb bodies are exothermic, so that the temperature of the exhaust gas when it leaves it is increased to such an extent that it is sufficient to bring the soot, which preferably accumulates in the second honeycomb bodies, to the required ignition temperature, which in turn is due to the presence the second coating is reduced.
  • the filter will continuously clean itself, while at the same time converting the nitrogen oxides, which are also considered to be harmful substances, and the carbon monoxide into harmless compounds.
  • the conical shape proposed in claim 2 at least for the second honeycomb body has been proven to improve the retention capacity of the same for soot particles.
  • At least the second honeycomb bodies are provided with an additional electrical heater in order to ensure that a temperature sufficient for the ignition of the soot is reached in the same, for example during idle operation. Because the exhaust gas as a result of in the first honeycomb bodies the exothermic reaction taking place is already heated, the additional electrical heating need only overcome a smaller temperature range and can then be fed without difficulty from the electrical system of a vehicle driven by the diesel engine.
  • the diesel particulate filter is provided with inlet channels for the supply of additional air. This ensures that sufficient oxygen is available for the oxidation of the soot particles.
  • the heat balance of the filter is improved by the embodiment proposed in claim 6, in which the inlet ducts for the supply air are in heat exchange with the latter before they enter the exhaust duct.
  • the inlet channels are provided with an additional heater.
  • this additional heating preferably consists of at least one electrically heated third honeycomb body through which the additional air flows.
  • the supply of additional air is usually caused by the soot pressure caused by the movement when using the diesel soot filter in vehicles.
  • the supply of additional air is at least temporarily supported by a blower.
  • honeycomb bodies are proposed to produce the first and / or second and / or third honeycomb bodies from a metallic material.
  • the same reasons are decisive, which have also caused the applicant to offer such honeycomb bodies as catalyst carriers for the detoxification of the exhaust gases from gasoline engines, namely a faster reaching of their operating temperature in addition to increased mechanical strength, as is particularly the case for use in road vehicles Meaning is.
  • the metal honeycomb body can be flowed through directly by the current and thus act as a heater for the proposed additional heating.
  • the first and / or second and / or third honeycomb bodies can be made from a ceramic material, in particular for motors that are operated at constant power, preferably stationary.
  • the catalytically active (and metallic) surface layer also used as a heating element of the auxiliary heater.
  • the proposed diesel soot filter can also be operated at lower exhaust gas temperatures, there is also the possibility according to claim 15 of arranging it in that part of the exhaust gas duct which is designed as a silencer. In this area, the space available for accommodating the diesel soot filter is generally better than in the vicinity of the engine, and the ones that are used anyway to dampen the exhaust sound, sometimes. ducts guided against one another can be integrated with the ducts for supplying the additional air to form a more favorable design.
  • the exhaust gas of a diesel engine is discharged through a channel 1, the direction of flow of the exhaust gases being indicated by the arrows 2.
  • the exhaust duct 1 opens into a muffler, which in a known manner consists of a prechamber 3, a main chamber 4 and a collecting chamber 5, which are separated from each other by baffles 6 and which is repeatedly deflected in its flow direction and Exhaust gas divided into partial streams flows through distributor openings 7 until it is brought together via collection openings 8 in a continuation of the exhaust gas duct 1 that finally opens into the atmosphere.
  • a plurality of honeycomb bodies are arranged in the exhaust gas stream 2, specifically alternating first honeycomb body 9 and second honeycomb body 10, here of cylindrical, partially designed as a ring.
  • the honeycomb bodies 9, 10 can be made from a ceramic material or, preferably, from sheet metal.
  • the first honeycomb bodies 9 are provided with a first coating containing platinum and / or rhodium, the catalytic effect of which on the exhaust gas leads to the carbon monoxide contained in it being oxidized to carbon dioxide while the various nitrogen oxides are being split, so that ultimately harmless products are released into the atmosphere. It is known to the person skilled in the art that this catalytic reaction only proceeds in the desired manner when a certain stoichiometric composition of the exhaust gas is present; Devices for regulating the composition of the exhaust gas, which are also not shown, are therefore required, but these are not the subject of the present invention and are assumed to be known.
  • the structure of the first honeycomb bodies 9 is relatively coarse-celled, so that the soot particles carried in the exhaust gas are not appreciably reflected in them, especially since the flow therein is largely laminar.
  • the second honeycomb bodies 10 have a smaller cell structure, so that the soot particles are highly likely to collide with the webs 11 separating the cells and stick to them. This effect is exacerbated by the fact that the webs 11 of the first honeycomb bodies 9 are bent out of the flow direction at least at their rear end seen in the flow direction and thus (see FIG. 4) form the noses 12 which promote swirling. This can be accomplished particularly easily in the case of metallic honeycomb bodies which are constructed from sheet metal layers 13, 14 which are spirally wound, alternately smooth and corrugated.
  • the second honeycomb bodies 10 are provided with a second coating containing silver vanadate, which has a catalytic effect by reducing the soot temperature of the soot accumulating here to such an extent that the (increased by the exothermic reaction in the first honeycomb bodies 9)
  • the temperature of the exhaust gas is sufficient to initiate combustion of the soot before it has blocked a significant number of cells in the second honeycomb body 10.
  • the combustion which is carried out as completely as possible, that is to say carbon dioxide, requires additional oxygen which is supplied through air channels 15.
  • These channels can be self-priming through a suitable design of their openings projecting into the exhaust gas stream 2, so that an adequate air supply is ensured even without the aid of external forces, for example the dynamic pressure on a moving vehicle equipped with the relevant diesel engine.
  • the air supply can be at least temporarily supported by a fan 16, as indicated schematically in FIG. Since the air channels 15 are guided in counterflow to the exhaust gas and are in heat exchange with it, sufficient preheating of the additional air can be expected in normal operation. Under special conditions, for example at extremely low ambient temperatures, it may be advantageous to provide a third honeycomb body 17 in the air duct 15, which is electrically conductive and acts as a heater by connection to a current source 18, which is also only indicated schematically. Expediently, like the first and second honeycomb bodies 9, 10, it is also constructed spirally from alternately smooth and corrugated sheet metal layers 13, 14 (shown in FIG.
  • the second honeycomb bodies 10 can be connected to the power source 18 and act as a heating element if, despite their increase due to the catalytic reaction in the first honeycomb bodies 9 and the effect of the second coating on the second honeycomb bodies 10, the exhaust gas temperature is not sufficient for the To burn soot.
  • honeycomb bodies 9, 10, 17 made of ceramic material are used, the catalytic layers expediently serve, since the metal itself is used as a heating conductor. Both metallic honeycomb bodies acting directly as a heating conductor, it goes without saying that the individual sheet-metal layers 13, 14 are separated from one another by insulating layers (not shown here) as soon as necessary.
  • the second honeycomb bodies 10 can have a conical shape as shown in FIG.
  • the diesel soot filter can be provided with thermal insulation 19.

Abstract

A diesel soot filter, which is self-cleaning in operation as a result of the soot burning off, has first honeycomb bodies (9) with a relatively coarse-cell structure and second honeycomb bodies (10) with a relatively fine-cell structure, which are arranged alternatingly in series, so that the soot substantially precipitates in the latter honeycomb bodies. The first honeycomb bodies (9) correspond to the catalysts used for the exhaust gas detoxification of spark-ignition engines and reduce the content of carbon monoxide and nitrogen oxides in the exhaust gas. The heat generated by this exothermic reaction and, if appropriate, by additional electric heating of the second honeycomb bodies (10) allows a temperature to be reached which, in conjunction with a catalytic coating of the second honeycomb bodies which reduces the ignition temperature of the soot, leads to combustion of the soot. To cover the oxygen requirement, preheated additional air is drawn in via separate ducts (15). Because of the improved heat balance, the diesel soot filter does not have to be fitted in the vicinity of the engine, but can be integrated into the silencer (3-5) of the engine. Both ceramic and metallic honeycomb bodies can be used, the catalytically active layer itself being designed as a heating conductor in the former case. <IMAGE>

Description

Die vorliegende Erfindung betrifft einen Dieselrußfilter, d.h. eine Einrichtung im Abgaskanal von selbstzündenden Verbrennungskraftmaschinen, die dazu geeignet ist, die Rußpartikel zurückzuhalten, die infolge unvollkommener Verbrennung des Brennstoffes im Abgas mitgeführt werden und denen gesundheitsschädliche Wirkungen zugeschrieben werden, wenn sie in die die Atmosphäre und damit in die Atemluft gelangen. Eine Herabsetzung des Rußausstoßes um etwa 2/3 kann mit wabenförmigen, meist aus einem keramischen Material hergestellten Filtern erreicht werden. Die zurückgehaltenen Rußpartikel verstopfen innerhalb einer verhältnismäßig kurzen Zeit die Kanäle in dem Wabenkörper soweit, daß infolge des dann auftretenden Druckverlustes die Leistung der Maschine herabgesetzt wird bzw. bei gleichbleibender Leistungabgabe der Kraftstoffverbrauch nennenswert erhöht wird. Die im Filter akkumulierten Rußpartikel müssen daher in regelmäßigen Zeitabständen durch Oxydation, d.h. Verbrennung wieder entfernt werden. Die Zündtemperatur des Rußes liegt dabei über der üblicherweise erreichten Abgastemperatur im Bereich von 540 °C, weshalb eine zusätzliche Wärmezufuhr erforderlich ist, um diese zu erreichen. Eine Übersicht über zu diesem Zweck vorgeschlagene Einrichtungen (z.B. Aufheizen durch einen mit dem Kraftstoff betriebenen Brenner oder durch einen aus dem Bordnetz gespeisten elektrischen Heizer) ergibt sich aus dem Artikel "Advanced Techniques for Thermal and Catalytic Diesel Particulate Trap Regeneration " von V. D. Rao u.a. in der SAE Technical Paper Series nach einem auf einem internationalen Kongress in Detroit/US anläßlich einer vom 25.2. - 1.3.1985 stattgehabten Ausstellung gehaltenen Vortrag. Danach ist zwar die elektrische Beheizung aus sicherheits- und verfahrens­technischen Gründen vorzuziehen, wegen des schlechten Wirkungsgrades der Stromerzeugung durch den von der Maschine selbst getriebenen Generator jedoch mit einem nennenswerten Mehrverbrauch an Kraftsoff verbunden. Die erforderliche Heiz­leistung kann nach den dort gemachten Vorschlägen herabgesetzt werden, wenn die Zündtemperatur des Rußes durch den Zusatz von katalytisch wirkenden Substanzen im Kraftstoff herabgesetzt werden kann. Aus der DE-A 37 11 101 ist der Vorschlag bekannt, die zum Erreichen der Zündtemperatur erforderliche Wärmezufuhr aus der Oxydation weiterer, zwangsläufig im Abgas mitgeführter Stoffe, wie Kohlenmonoxyd und Kohlenwasserstoffen zu gewinnen; diese Oxydation erfolgt katalytisch an der Oberfläche von z.B. mit einer Platinbeschichtung versehenen Wabenkörpern der beschriebenen Art, wie sie auch zur Reduktion des Schadstoff­anteils in den Abgasen von Ottomotoren verwendet werden. Die genannte Schrift lehrt auch, die zur Bereitstellung des für die Oxydation benötigten Sauerstoffes eingeblasene Zusatzluft vorzuwärmen, indem sie im Wärmeaustausch mit den Abgasen geführt wird.The present invention relates to a diesel soot filter, that is to say a device in the exhaust duct of self-igniting internal combustion engines, which is suitable for retaining the soot particles which are entrained in the exhaust gas as a result of imperfect combustion of the fuel and to which harmful effects are attributed when they enter the atmosphere and thus get into the air. A reduction in soot emissions by about 2/3 can be achieved with honeycomb filters, which are usually made of a ceramic material. The retained soot particles clog the channels in the honeycomb body within a comparatively short time to such an extent that the performance of the machine is reduced as a result of the pressure loss which then occurs, or the fuel consumption is significantly increased while the power output remains the same. The soot particles accumulated in the filter must therefore be removed at regular intervals by oxidation, ie combustion. The ignition temperature of the soot is above the usually reached exhaust gas temperature in the range of 540 ° C, which is why an additional heat supply is required to achieve this. An overview of devices proposed for this purpose (for example heating by a fuel-operated burner or by an electric heater fed from the vehicle electrical system) can be found in the article "Advanced Techniques for Thermal and Catalytic Diesel Particulate Trap Regeneration" by VD Rao et al of the SAE Technical Paper Series after an at an international congress in Detroit / US on the 25.2. - Lecture held on 1.3.1985. According to this, the electric heating is preferable for safety and procedural reasons, but because of the poor efficiency of the power generation by the generator driven by the machine itself, it is worth mentioning Increased consumption of fuel. The heating power required can be reduced according to the suggestions made there if the ignition temperature of the soot can be reduced by the addition of catalytically active substances in the fuel. From DE-A 37 11 101 the proposal is known to obtain the heat supply required to reach the ignition temperature from the oxidation of further substances which are inevitably entrained in the exhaust gas, such as carbon monoxide and hydrocarbons; this oxidation takes place catalytically on the surface of honeycomb bodies of the type described, for example provided with a platinum coating, as are also used to reduce the proportion of pollutants in the exhaust gases of gasoline engines. The cited document also teaches to preheat the additional air blown in to provide the oxygen required for the oxidation by being conducted in heat exchange with the exhaust gases.

Aufgabe der vorliegenden Erfindung ist ein Dieselrußfilter der beschriebenen Art, in dem die zurückgehaltenen Rußpartikel ggf. intermittierend auch dann oxydiert werden, wenn der Dieselmotor nur in Teillast betrieben wird, wobei die Abgastemperatur regelmäßig unterhalb der Zündtemperatur des Rußes liegt; dies auch dann, wenn dieselbe (nach dem aus der EP-A- 0 077 524 bekannten Vorschlag) auf katalytischem Wege (z.B. auch durch Kontaktierung mit einer entsprechend wirksamen Oberfläche des Filters) auf Werte um 350 °C herabgesetzt worden ist. Der Energiebedarf für eine etwa notwendig werdende Zusatzheizung soll minimiert werden und eine Ausgestaltung des Filters vorgeschlagen werden, die in besonderer Weise geeignet ist, den Ablauf der verschiedenen chemischen Prozesse zu unterstützen.The object of the present invention is a diesel soot filter of the type described, in which the retained soot particles are optionally intermittently oxidized even when the diesel engine is only operated at partial load, the exhaust gas temperature regularly being below the ignition temperature of the soot; this is also the case if it (according to the proposal known from EP-A-0 077 524) has been reduced catalytically (e.g. also by contacting a correspondingly effective surface of the filter) to values around 350 ° C. The energy requirement for any additional heating that may become necessary should be minimized and an embodiment of the filter proposed that is particularly suitable for supporting the course of the various chemical processes.

Die Lösung dieser Aufgabe erfolgt dadurch, daß der Dieselruß­filter aus mehreren im Abgaskanal abwechselnd hintereinander angeordneten ersten und zweiten mit Durchströmkanälen versehe­nen Wabenkörpern besteht, von denen die ersten Wabenkörper mit einer ersten Oberflächenschicht versehen sind, die in an sich bekannter Weise katalytisch die Umsetzung von Stickoxyden und Kohlenmonoxyd zu Stickstoff bzw. Kohlendioxyd bewirkt, während die zweiten Wabenkörper mit einer zweiten Oberflächenschicht versehen sind, die in an sich bekannter Weise katalytisch eine Herabsetzung der Zündtemperatur des ihr anhaftenden Rußes bewirkt. Die in den ersten Wabenkörpern ablaufenden Reaktionen sind bekanntlich exotherm, so daß die Temperatur des Abgases beim Verlassen derselben soweit erhöht ist, daß sie ausreicht, um den sich bevorzugt in den zweiten Wabenkörpern ansammelnden Ruß auf die erforderliche Zündtemperatur zu bringen, die ihrerseits durch das Vorhandensein der zweiten Beschichtung herabgesetzt ist. Bei den meisten Betriebszuständen des Diesel­motors wird so eine kontinuierliche Selbstreinigung des Filters stattfinden, wobei gleichzeitig die ebenfalls als Schadstoffe anzusehenden Stickoxyde und das Kohlenmonoxyd in unbedenkliche Verbindungen überführt werden. Die im 2. Anspruch zumindest für die zweiten Wabenkörper vorgeschlagene Kegelform verbessert nachgewiesenermaßen das Rückhaltevermögen derselben für Rußpartikel.This object is achieved in that the diesel particulate filter consists of a plurality of first and second honeycomb bodies, which are alternately arranged one behind the other in the exhaust gas channel and provided with throughflow channels, of which the first honeycomb bodies are provided with a first surface layer, which in itself in a known manner catalytically causes the conversion of nitrogen oxides and carbon monoxide to nitrogen or carbon dioxide, while the second honeycomb bodies are provided with a second surface layer which, in a manner known per se, catalytically reduces the ignition temperature of the soot adhering to it. As is known, the reactions taking place in the first honeycomb bodies are exothermic, so that the temperature of the exhaust gas when it leaves it is increased to such an extent that it is sufficient to bring the soot, which preferably accumulates in the second honeycomb bodies, to the required ignition temperature, which in turn is due to the presence the second coating is reduced. In most operating states of the diesel engine, the filter will continuously clean itself, while at the same time converting the nitrogen oxides, which are also considered to be harmful substances, and the carbon monoxide into harmless compounds. The conical shape proposed in claim 2 at least for the second honeycomb body has been proven to improve the retention capacity of the same for soot particles.

In die gleiche Richtung neben einer Vergleichmäßigung des Temperaturprofils wirkt die im 3. Anspruch vorgeschlagene Ausgestaltung, bei der zumindest die ersten Wabenkörper eine Form aufweisen, die eine in Stromrichtung hinter ihnen erfol­gende Verwirbelung des Abgasstromes unterstützt. Dadurch, daß die Abgasströmung in Lee der ersten Wabenkörper turbulent ist, erhöht sich die Wahrscheinlichkeit, daß die Rußpartikel in den zweiten Wabenkörpern gegen die Wände desselben prallen und dort festgehalten sowie durch die katalytische Wirkung der zweiten Beschichtung in ihrer Zündtemperatur herabgesetzt werden.The embodiment proposed in claim 3, in which at least the first honeycomb bodies have a shape which supports a swirling of the exhaust gas flow downstream in the flow direction, acts in the same direction in addition to a uniformization of the temperature profile. Because the exhaust gas flow in the lee of the first honeycomb bodies is turbulent, the probability increases that the soot particles in the second honeycomb bodies collide with the walls thereof and are held there and are reduced in their ignition temperature by the catalytic effect of the second coating.

Gemäß dem 4. Anspruch sind zumindest die zweiten Wabenkörper mit einer elektrischen Zusatzbeheizung versehen, um sicherzu­stellen, daß auch z.B. bei Leerlaufbetrieb in denselben eine für die Zündung des Rußes ausreichende Temperatur erreicht wird. Da das Abgas infolge der in den ersten Wabenkörpern stattfindenden exothermen Reaktion bereits aufgeheizt wird, braucht die elektrische Zusatzheizung nur eine geringere Tem­peraturspanne zu überwinden und kann dann ohne Schwierigkeiten aus dem Bordnetz eines mit dem Dieselmotor angetriebenen Fahrzeuges gespeist werden.According to the fourth claim, at least the second honeycomb bodies are provided with an additional electrical heater in order to ensure that a temperature sufficient for the ignition of the soot is reached in the same, for example during idle operation. Because the exhaust gas as a result of in the first honeycomb bodies the exothermic reaction taking place is already heated, the additional electrical heating need only overcome a smaller temperature range and can then be fed without difficulty from the electrical system of a vehicle driven by the diesel engine.

Als nützliche Ausgestaltung der Erfindung wird im 5. Anspruch vorgeschlagen, daß der Dieselrußfilter mit Einlaßkanälen für die Zufuhr von Zusatzluft versehen ist. Hierdurch wird sicher­gestellt, daß für die Oxydation der Rußpartikel ausreichender Sauerstoff zur Verfügung steht.As a useful embodiment of the invention, it is proposed in claim 5 that the diesel particulate filter is provided with inlet channels for the supply of additional air. This ensures that sufficient oxygen is available for the oxidation of the soot particles.

Die Wärmebilanz des Filters wird durch die im 6. Anspruch vor­geschlagene Ausgestaltung verbessert, in der die Einlaßkanäle für die Zuluft vor ihrem Eintritt in den Abgaskanal im Wärme­austausch mit letzterem stehen.The heat balance of the filter is improved by the embodiment proposed in claim 6, in which the inlet ducts for the supply air are in heat exchange with the latter before they enter the exhaust duct.

Beim Betrieb des Dieselrußfilters bei extrem niedrigen Tempe­raturen und im niedrigen Lastbereich ist damit zu rechnen, daß auf diese Weise keine ausreichende Vorwärmung der Zusatzluft erfolgt. Dementsprechend wir im 7. Anspruch vorgeschlagenen, daß die Einlaßkanäle mit einer Zusatzheizung versehen sind.When operating the diesel soot filter at extremely low temperatures and in the low load range, it can be expected that the auxiliary air will not be sufficiently preheated in this way. Accordingly, we proposed in claim 7 that the inlet channels are provided with an additional heater.

Gemäß dem 8. Anspruch besteht diese Zusatzheizung vorzugsweise aus mindestens einem von der Zusatzluft durchströmten, elektrisch beheizten dritten Wabenkörper.According to claim 8, this additional heating preferably consists of at least one electrically heated third honeycomb body through which the additional air flows.

Die Zufuhr der Zusatzluft wird beim Einsatz der Dieselrußfilter in Fahrzeugen üblicherweise durch den durch die Bewegung her­vorgerufenen Staudruck bewirkt. Bei Stillstand des Fahrzeuges oder aber für stationäre Anlagen wird gemäß dem 9. Anspruch vorgeschlagen, daß die Zufuhr von Zusatzluft zumindest zeitweise durch ein Gebläse unterstützt wird.The supply of additional air is usually caused by the soot pressure caused by the movement when using the diesel soot filter in vehicles. When the vehicle is at a standstill or for stationary systems, it is proposed according to claim 9 that the supply of additional air is at least temporarily supported by a blower.

Das im 10. Anspruch vorgeschlagene Merkmal, demzufolge die Zellenzahl der ersten Wabenkörper geringer ist als diejenigen der zweiten Wabenkörper stellt sicher, daß die Abscheidung der Rußpartikel in erster Linie in letzteren erfolgt und nicht etwa zu einer Verstopfung der Kanäle bereits in den ersten Waben­körpern fühlt. Zusätzlich wird durch dieses Merkmal die Verwirbelung des Abgasstromes unterstützt.The feature proposed in claim 10, according to which the number of cells in the first honeycomb body is lower than those the second honeycomb body ensures that the soot particles are deposited primarily in the latter and do not already feel that the channels are blocked in the first honeycomb bodies. This feature also supports the swirling of the exhaust gas flow.

Im 11. Anspruch wird vorgeschlagen, die ersten und/oder zweiten und/oder dritten Wabenkörper aus einem metallischen Werkstoff herzustellen. Hierfür sind größtenteils die gleichen Gründe maßgebend, die auch die Anmelderin dazu veranlaßt haben, derartige Wabenkörper als Katalysatorträger für die Entgiftung der Abgase von Ottomotoren anzubieten, nämlich ein schnelleres Erreichen ihrer Betriebstemperatur neben einer erhöhten mechanischen Festigkeit, wie sie insbesondere für den Einsatz in Straßenfahrzeugen von Bedeutung ist. Darüberhinaus kann der metallische Wabenkörper unmittelbar vom Strom durchflossen werden und so als Heizkörper für die vorgeschlagene Zusatzheizung fungieren.In claim 11 it is proposed to produce the first and / or second and / or third honeycomb bodies from a metallic material. For the most part, the same reasons are decisive, which have also caused the applicant to offer such honeycomb bodies as catalyst carriers for the detoxification of the exhaust gases from gasoline engines, namely a faster reaching of their operating temperature in addition to increased mechanical strength, as is particularly the case for use in road vehicles Meaning is. In addition, the metal honeycomb body can be flowed through directly by the current and thus act as a heater for the proposed additional heating.

Im 12. Anspruch wird ein weiteres, die Verwirbelung des Abgas­stromes unterstützendes Merkmal vorgeschlagen, nämlich daß die die Zellen voneinander trennenden Stege der 1. Wabenkörper an ihrer stromabwärts gerichteten Kante aus der Strömungsrichtung gebogen sind. Die dadurch bewirkte Erhöhung des Druckverlustes in den Wabenkörpern ist nur gering, da infolge der besseren Verwirbelung die nötige Abscheidewahrscheinlichkeit für die Rußpartikel auch schon in zweiten Wabenkörpern geringerer Länge und somit verringerten Druckverlustes erreicht wird.In claim 12, a further feature which supports the swirling of the exhaust gas flow is proposed, namely that the webs separating the cells of the first honeycomb body are bent at their downstream edge from the direction of flow. The resulting increase in pressure loss in the honeycomb bodies is only slight, since, due to the better swirling, the necessary separation probability for the soot particles is also achieved in second honeycomb bodies of shorter length and thus reduced pressure loss.

Entsprechend dem 13. Anspruch können die ersten und/oder zweiten und/oder dritten Wabenkörper aus einem keramischen Werkstoff hergestellt sein, insbesondere für bei gleichbleiben­der Leistung betriebene, vorzugsweise stationäre Motoren.According to claim 13, the first and / or second and / or third honeycomb bodies can be made from a ceramic material, in particular for motors that are operated at constant power, preferably stationary.

In diesem Falle wird entsprechend der im 14. Anspruch angege­benen Ausgestaltung der Erfindung die katalytisch aktive (und metallische) Oberflächenschicht zugleich als Heizelement der Zusatzheizung verwendet.In this case, the catalytically active (and metallic) surface layer also used as a heating element of the auxiliary heater.

Da der vorgeschlagene Dieselrußfilter auch bei geringeren Abgastemperaturen betrieben werden kann, ergibt sich gemäß dem 15. Anspruch auch die Möglichkeit, ihn in demjenigen Teil des Abgaskanales anzuordnen, der als Schalldämpfer ausgebildet ist. In diesem Bereich sind die Platzverhältnisse für die Unter­bringung des Dieselrußfilters im allgemeinen besser als in Motornähe und die ohnehin der Dämpfung des Auspuffschalles dienenden, z.T. gegeneinander geführten Kanäle können mit den Kanälen für die Zufuhr der Zusatzluft zu einer günstigeren Konstruktion integriert werden.Since the proposed diesel soot filter can also be operated at lower exhaust gas temperatures, there is also the possibility according to claim 15 of arranging it in that part of the exhaust gas duct which is designed as a silencer. In this area, the space available for accommodating the diesel soot filter is generally better than in the vicinity of the engine, and the ones that are used anyway to dampen the exhaust sound, sometimes. ducts guided against one another can be integrated with the ducts for supplying the additional air to form a more favorable design.

Ausführungsbeispiele der Erfindung sind in der Zeichnung darge­stellt, und zwar zeigt

  • Figur 1 einen in einem Schalldämpfer integrierten Dieselrußfilter im Längsaxialschnitt,
  • Figur 2 einen an anderer Stelle des Abgaskanales angeordneten Dieselrußfilter, ebenfalls im Längsaxialschnitt,
  • Figur 3 einen Querschnitt entsprechend der Linie III-III der Figur 2 und
  • Figur 4 in vergrößertem Maßstab die Einzelheit IV der Figur 3.
Embodiments of the invention are shown in the drawing, namely shows
  • FIG. 1 shows a diesel soot filter integrated in a silencer in a longitudinal axial section,
  • FIG. 2 shows a diesel soot filter arranged at another point in the exhaust gas duct, likewise in a longitudinal axial section,
  • Figure 3 shows a cross section along the line III-III of Figure 2 and
  • FIG. 4 shows detail IV of FIG. 3 on an enlarged scale.

Durch einen Kanal 1 wird das Abgas eines hier nicht gezeigten Dieselmotors abgeführt, wobei die Strömungsrichtung der Abgase durch die Pfeile 2 angedeutet ist. In der in der Figur 1 dar­gestellten Ausführungsform mündet der Abgaskanal 1 in einem Schalldämpfer, der in bekannter Weise aus einer Vorkammer 3, einer Hauptkammer 4 und einer Sammelkammer 5 besteht, die durch Schallwände 6 voneinander getrennt sind und den das mehrfach in seiner Strömungsrichtung umgelenkte und über Verteileröffnungen 7 in Teilströme aufgeteilte Abgas durchströmt, bis es über Sammelöffnungen 8 in einer schließlich in der Atmosphäre mündenden Fortsetzung des Abgaskanales 1 zusammengeführt wird. Im Abgasstrom 2 angeordnet sind mehrere Wabenkörper, und zwar abwechselnd erste Wabenkörper 9 und zweite Wabenkörper 10, hier von zylindrischer, zum Teil als Ring ausgestalteter Form. Die Wabenkörper 9, 10 können aus einem keramischen Material hergestellt sein oder aber vorzugsweise aus Metallblech. In jedem Falle sind die ersten Wabenkörper 9 mit einer ersten, platin- und/oder rhodiumhaltigen Beschichtung versehen, deren katalytische Wirkung auf das Abgas dazu führt, daß das in ihm enthaltene Kohlenmonoxyd zu Kohlendioxyd oxydiert wird, während die verschiedenen Stickoxyde gespalten werden, so daß schließ­lich unschädliche Produkte an die Atmosphäre abgegeben werden. Es ist dem Fachmann bekannt, daß diese katalytische Reaktion nur beim Vorliegen einer bestimmten stöchiometrischen Zusammen­setzung des Abgases in der gewünschten Weise abläuft; es sind daher hier ebenfalls nicht gezeigte Einrichtungen zur Regelung der Zusammensetzung des Abgases erforderlich, die jedoch nicht Gegenstand der vorliegenden Erfindung sind und als bekannt vorausgesetzt werden. Die Struktur der ersten Wabenkörper 9 ist verhältnismäßig grobzellig, so daß die im Abgas mitgeführten Rußpartikel sich in diesen nicht in nennenswerter Weise nieder­schlagen, zumal die darin herschende Strömung weitgehend laminar ist. Die zweiten Wabenkörper 10 weisen eine kleinzelligere Struktur auf, so daß die Rußpartikel mit hoher Wahrscheinlichkeit mit den die Zellen voneinander scheidenden Stegen 11 kollidieren und an ihnen klebenbleiben. Dieser Effekt wird noch verstärkt dadurch, daß die Stege 11 der ersten Wabenkörper 9 zumindest an ihrem in Strömungsrichtung gesehenen hinteren Ende aus der Strömungsrichtung gebogen sind und so (siehe Figur 4) die Verwirbelung fördernde Nasen 12 bilden. Dies läßt sich besonders einfach bei metallischen Wabenkörpern bewerkstelligen, die aus spiralig umeinander gewickelten, ab­wechselnd glatten und gewellten Blechlagen 13, 14 aufgebaut sind. Die zweiten Wabenkörper 10 sind mit einer zweiten, Silbervanadat enthaltenden Beschichtung versehen, die kataly­tisch dahingehend wirkt, daß der hier sich ansammelnde Ruß in seiner Zündtemperatur soweit herabgesetzt wird, daß die (durch die exotherme Reaktion in den ersten Wabenkörpern 9 erhöhte) Temperatur des Abgases ausreicht, um eine Verbrennung des Rußes einzuleiten, bevor dieser eine nennenswerte Anzahl der Zellen der zweiten Wabenkörper 10 verstopft hat. Die möglichst vollständig durchgeführte, das heißt Kohlendioxyd liefernde Verbrennung erfordert zusätzlichen Sauerstoff, der durch Luft­kanäle 15 zugeführt wird. Diese Kanäle können durch geeignete Ausgestaltung ihrer in den Abgasstrom 2 ragenden Öffnungen selbstansaugend wirken, so daß auch ohne Zuhilfenahme äußerer Kräfte, z.B. des Staudruckes auf ein sich bewegendes, mit dem betreffenden Dieselmotor ausgerüstetes Fahrzeug eine ausrei­chende Luftzufuhr gesichert ist. Sollte die so bewirkte Sauer­stoffzufuhr infolge geringer Abgasgeschwindigkeit (z.B. beim Leerlaufbetrieb des Motors) nicht ausreichen, kann, wie in der Figur 2 schematisch angedeutet, die Luftzufuhr durch ein Gebläse 16 zumindest zeitweise unterstützt werden. Da die Luftkanäle 15 im Gegenstrom zum Abgas geführt sind und mit diesem im Wärmeaustausch stehen, kann im Normalbetrieb mit einer ausreichenden Vorwärmung der Zusatzluft gerechnet werden. Unter besonderen Bedingungen, z.B. bei extrem niedrigen Umge­bungstemperaturen, kann es vorteilhaft sein, im Luftkanal 15 einen dritten Wabenkörper 17 vorzusehen, der elektrisch leitend ist und durch Anschluß an eine ebenfalls nur schematisch ange­deutete Stromquelle 18 als Heizkörper wirkt. Zweckmäßigerweise ist er ebenfalls wie die ersten und zweiten Wabenkörper 9, 10 spiralig aus abwechselnd glatten und gewellten Blechlagen 13, 14 aufgebaut (in der Figur 3 entgegen der Blickrichtung dar­gestellt). In gleicher Weise können die zweiten Wabenkörper 10 an die Stromquelle 18 angeschlossen werden und als Heizkörper wirken, wenn die Abgastemperatur trotz ihrer Steigerung durch die katalytische Reaktion in den ersten Wabenkörpern 9 und der Wirkung der zweiten Beschichtung auf den zweiten Wabenkörpern 10 nicht ausreicht, um den Ruß zu verbrennen. Werden aus keramischem Material hergestellte Wabenkörper 9, 10, 17 verwendet, so dienen zweckmäßigerweise die katalytischen Schichten, da aus Metall selbst als Heizleiter. Bei den unmittelbar als Heizleiter wirkenden metallischen Wabenkörpern versteht es sich, daß sobald erforderlich die einzelnen Blechlagen 13, 14 durch hier nicht dargestellte isolierende Schichten voneinander getrennt sind. Die zweiten Wabenkörper 10 können wie in der Figur 2 dargestellte kegelige Form haben; es hat sich gezeigt, daß diese Form die Rückhaltefähigkeit für Rußpartikel erhöht. Bei den bevorzugt vorgeschlagenen, aus aufeinandergewickelten Blechlagen 13, 14 hergestellten metal­lischen Wabenkörpern läßt sich diese Form unschwer herstellen, indem der Zentralbereich des Körpers nach dem Aufwickeln axial herausgedrückt wird. Zur weiteren Unterstützung der Wärmebilanz kann der Dieselrußfilter mit einer Wärmeisolierung 19 versehen sein.The exhaust gas of a diesel engine, not shown here, is discharged through a channel 1, the direction of flow of the exhaust gases being indicated by the arrows 2. In the embodiment shown in Figure 1, the exhaust duct 1 opens into a muffler, which in a known manner consists of a prechamber 3, a main chamber 4 and a collecting chamber 5, which are separated from each other by baffles 6 and which is repeatedly deflected in its flow direction and Exhaust gas divided into partial streams flows through distributor openings 7 until it is brought together via collection openings 8 in a continuation of the exhaust gas duct 1 that finally opens into the atmosphere. A plurality of honeycomb bodies are arranged in the exhaust gas stream 2, specifically alternating first honeycomb body 9 and second honeycomb body 10, here of cylindrical, partially designed as a ring. The honeycomb bodies 9, 10 can be made from a ceramic material or, preferably, from sheet metal. In any case, the first honeycomb bodies 9 are provided with a first coating containing platinum and / or rhodium, the catalytic effect of which on the exhaust gas leads to the carbon monoxide contained in it being oxidized to carbon dioxide while the various nitrogen oxides are being split, so that ultimately harmless products are released into the atmosphere. It is known to the person skilled in the art that this catalytic reaction only proceeds in the desired manner when a certain stoichiometric composition of the exhaust gas is present; Devices for regulating the composition of the exhaust gas, which are also not shown, are therefore required, but these are not the subject of the present invention and are assumed to be known. The structure of the first honeycomb bodies 9 is relatively coarse-celled, so that the soot particles carried in the exhaust gas are not appreciably reflected in them, especially since the flow therein is largely laminar. The second honeycomb bodies 10 have a smaller cell structure, so that the soot particles are highly likely to collide with the webs 11 separating the cells and stick to them. This effect is exacerbated by the fact that the webs 11 of the first honeycomb bodies 9 are bent out of the flow direction at least at their rear end seen in the flow direction and thus (see FIG. 4) form the noses 12 which promote swirling. This can be accomplished particularly easily in the case of metallic honeycomb bodies which are constructed from sheet metal layers 13, 14 which are spirally wound, alternately smooth and corrugated. The second honeycomb bodies 10 are provided with a second coating containing silver vanadate, which has a catalytic effect by reducing the soot temperature of the soot accumulating here to such an extent that the (increased by the exothermic reaction in the first honeycomb bodies 9) The temperature of the exhaust gas is sufficient to initiate combustion of the soot before it has blocked a significant number of cells in the second honeycomb body 10. The combustion which is carried out as completely as possible, that is to say carbon dioxide, requires additional oxygen which is supplied through air channels 15. These channels can be self-priming through a suitable design of their openings projecting into the exhaust gas stream 2, so that an adequate air supply is ensured even without the aid of external forces, for example the dynamic pressure on a moving vehicle equipped with the relevant diesel engine. If the oxygen supply caused in this way is not sufficient owing to the low exhaust gas speed (for example when the engine is idling), the air supply can be at least temporarily supported by a fan 16, as indicated schematically in FIG. Since the air channels 15 are guided in counterflow to the exhaust gas and are in heat exchange with it, sufficient preheating of the additional air can be expected in normal operation. Under special conditions, for example at extremely low ambient temperatures, it may be advantageous to provide a third honeycomb body 17 in the air duct 15, which is electrically conductive and acts as a heater by connection to a current source 18, which is also only indicated schematically. Expediently, like the first and second honeycomb bodies 9, 10, it is also constructed spirally from alternately smooth and corrugated sheet metal layers 13, 14 (shown in FIG. 3 against the viewing direction). In the same way, the second honeycomb bodies 10 can be connected to the power source 18 and act as a heating element if, despite their increase due to the catalytic reaction in the first honeycomb bodies 9 and the effect of the second coating on the second honeycomb bodies 10, the exhaust gas temperature is not sufficient for the To burn soot. If honeycomb bodies 9, 10, 17 made of ceramic material are used, the catalytic layers expediently serve, since the metal itself is used as a heating conductor. Both metallic honeycomb bodies acting directly as a heating conductor, it goes without saying that the individual sheet-metal layers 13, 14 are separated from one another by insulating layers (not shown here) as soon as necessary. The second honeycomb bodies 10 can have a conical shape as shown in FIG. 2; it has been shown that this shape increases the retention capacity for soot particles. In the case of the preferably proposed metallic honeycomb bodies produced from sheet metal layers 13, 14 wound on one another, this shape can be easily produced by axially pressing out the central region of the body after winding. To further support the heat balance, the diesel soot filter can be provided with thermal insulation 19.

Claims (15)

1. Dieselrußfilter, dadurch gekenzeichnet, daß er aus mehreren im Abgaskanal (1) abwechselnd hintereinander angeordneten ersten und zweiten mit Durchströmkanälen versehenen Wabenkörpern (9,10) besteht, von denen die ersten Wabenkörper (9) mit einer ersten Oberflächenschicht versehen sind, die in an sich bekannter Weise katalytisch die Umsetzung von Stickoxyden und Kohlenmonoxyd zu Stickstoff bzw. Kohlendioxyd bewirkt, während die zweiten Wabenkörper (10) mit einer zweiten Oberflächenschicht versehen sind, die in an sich bekannter Weise katalytisch eine Herabsetzung der Zündtemperatur des ihr anhaftenden Rußes bewirkt.1. Diesel soot filter, characterized in that it consists of a plurality of alternately arranged first and second honeycomb bodies (9, 10) provided with through-flow channels in the exhaust gas duct (1), of which the first honeycomb bodies (9) are provided with a first surface layer, which in in a manner known per se catalytically causes the conversion of nitrogen oxides and carbon monoxide to nitrogen or carbon dioxide, while the second honeycomb bodies (10) are provided with a second surface layer which, in a manner known per se, catalytically reduces the ignition temperature of the soot adhering to them. 2. Dieselrußfilter nach Anspruch 1, dadurch gekennzeichnet, daß zumindest die zweiten Wabenkörper (10) Kegelform aufweisen.2. Diesel soot filter according to claim 1, characterized in that at least the second honeycomb body (10) have a conical shape. 3. Dieselrußfilter nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß zumindest die ersten Wabenkörper (9) eine Form (12) aufweisen, die eine in Stromrichtung hinter ihnen erfolgende Verwirbelung des Abgasstromes (2) unterstützt.3. Diesel soot filter according to claim 1 or 2, characterized in that at least the first honeycomb body (9) have a shape (12) which supports a swirling of the exhaust gas stream (2) behind them in the flow direction. 4. Dieselrußfilter nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß zumindest die zweiten Wabenkörper (10) mit einer elektrischen Zusatzbeheizung (18) versehen sind.4. Diesel soot filter according to one or more of the preceding claims, characterized in that at least the second honeycomb body (10) are provided with an additional electrical heater (18). 5. Dieselrußfilter nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß er mit Einlaßkanälen (15) für die Zufuhr von Zusatzluft versehen ist.5. Diesel soot filter according to one or more of the preceding claims, characterized in that it is provided with inlet channels (15) for the supply of additional air. 6. Dieselrußfilter nach Anspruch 5, dadurch gekennzeichnet, daß die Einlaßkanale (15) vor ihrem Eintritt in den Abgaskanal (1) im Wärmeaustausch mit letzterem stehen.6. Diesel soot filter according to claim 5, characterized characterized in that the inlet ducts (15) are in heat exchange with the latter before they enter the exhaust duct (1). 7. Dieselrußfilter nach Anspruch 5 und/oder 6, dadurch gekennzeichnet, daß die Einlaßkanäle (15) mit einer Zusatzheizung (17) versehen sind.7. Diesel soot filter according to claim 5 and / or 6, characterized in that the inlet channels (15) are provided with an additional heater (17). 8. Dieselrußfilter nach Anspruch 7, dadurch gekennzeichnet, daß die Zusatzheizung aus mindestens einem von der Zusatzluft durchströmten, elektrisch (18) beheizten dritten Wabenkörper (17) besteht.8. Diesel soot filter according to claim 7, characterized in that the additional heating consists of at least one, through which the additional air flows, electrically (18) heated third honeycomb body (17). 9. Dieselrußfilter nach einem oder mehreren der Ansprüche 5 bis 8, dadurch gekennzeichnet, daß ein Gebläse (16) vorhanden ist, durch das die Zufuhr von Zusatzluft zumindest zeitweise unterstützt wird.9. Diesel soot filter according to one or more of claims 5 to 8, characterized in that a blower (16) is provided by which the supply of additional air is at least temporarily supported. 10. Dieselrußfilter nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Zellenzahl der ersten Wabenkörper (9) geringer ist als diejenigen der zweiten Wabenkörper (10).10. Diesel soot filter according to one or more of the preceding claims, characterized in that the number of cells of the first honeycomb body (9) is less than that of the second honeycomb body (10). 11. Dieselrußfilter nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die ersten (9) und/oder zweiten (10) und/oder dritten (17) Wabenkörper aus einem metallischen Werkstoff hergestellt sind.11. Diesel soot filter according to one or more of the preceding claims, characterized in that the first (9) and / or second (10) and / or third (17) honeycomb bodies are made of a metallic material. 12. Dieselrußfilter nach Anspruch 3 und 11, dadurch gekennzeichnet, daß die die Zellen voneinander trennenden Stege (11) der ersten Wabenkörper (9) an ihrer stromabwärts gerichteten Kante aus der Strömungsrichtung gebogen (12) sind.12. Diesel soot filter according to claim 3 and 11, characterized in that the webs separating the cells (11) of the first honeycomb body (9) are bent (12) at their downstream edge from the flow direction. 13. Dieselrußfilter nach einem oder mehreren der Ansprüche 1 bis 10, dadurch gekennzeichnet, daß die ersten (9) und/oder zweiten (10) und/oder dritten (10) Wabenkörper aus einem keramischen Werkstoff hergestellt sind.13. Diesel particulate filter according to one or more of claims 1 to 10, characterized in that the first (9) and / or second (10) and / or third (10) honeycomb bodies are made of a ceramic material. 14. Dieselrußfilter nach Anspruch 4 und 13, dadurch gekennzeichnet, daß die katalytisch aktive Oberflächenschicht zugleich Heizelement der Zusatzheizung ist.14. Diesel soot filter according to claim 4 and 13, characterized in that the catalytically active surface layer is also the heating element of the additional heating. 15. Dieselrußfilter nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß er in demjenigen Teil des Abgaskanales (1) angeordnet ist, der als Schalldämpfer (3-5) ausgebildet ist.15. Diesel soot filter according to one or more of the preceding claims, characterized in that it is arranged in that part of the exhaust gas duct (1) which is designed as a silencer (3-5).
EP89201062A 1989-04-17 1989-04-17 Diesel soot filter with an additional arrangement for the reduction of nitrogen oxides and/or the oxidation of carbon monoxide Withdrawn EP0393257A1 (en)

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DE4110395A1 (en) * 1991-03-28 1992-10-01 Roth Technik Gmbh CATALYST
EP0556846A1 (en) * 1992-02-19 1993-08-25 LEISTRITZ AG &amp; CO. Abgastechnik Exhaust silencer for diesel engines, particularly for commercial vehicles
WO1994008698A1 (en) * 1992-10-08 1994-04-28 Air Safe Exhaust Systems Pty. Ltd. Gas filter
EP1276549A1 (en) 2000-04-25 2003-01-22 Emitec Gesellschaft für Emissionstechnologie mbH Method for removing soot particles from an exhaust gas and corresponding collecting element
DE10361791A1 (en) * 2003-12-31 2005-07-28 Volkswagen Ag Exhaust gas cleaning device regenerating method for e.g. Otto engine, involves exhibiting catalyst by device, and pressuring filter with secondary air, when catalyst is desulphurized with hypostoichiometric exhaust gas
US7340888B2 (en) 2005-04-26 2008-03-11 Donaldson Company, Inc. Diesel particulate matter reduction system
DE102008022081A1 (en) * 2008-05-05 2009-11-12 J. Eberspächer GmbH & Co. KG Exhaust gas treatment device
US7862640B2 (en) 2006-03-21 2011-01-04 Donaldson Company, Inc. Low temperature diesel particulate matter reduction system
US8763375B2 (en) 2010-08-19 2014-07-01 J. Eberspaecher Gmbh & Co. Kg Exhaust gas cleaning device, exhaust system, removal method
CN104165256A (en) * 2013-05-17 2014-11-26 中国科学院声学研究所 Active sound eliminator for ventilation pipeline system
CN104165255A (en) * 2013-05-17 2014-11-26 中国科学院声学研究所 Active-passive composite silencer for ventilation pipeline
US9222392B2 (en) 2010-04-15 2015-12-29 Eberspaecher Exhaust Technology Gmbh & Co. Kg Exhaust gas treatment device
CN105370358A (en) * 2015-11-24 2016-03-02 徐秋苹 Motorcycle exhaust pipe
CN109356686A (en) * 2018-11-05 2019-02-19 卢宝良 Diesel motor exhaust black-smoke purifier

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DE4110395A1 (en) * 1991-03-28 1992-10-01 Roth Technik Gmbh CATALYST
EP0556846A1 (en) * 1992-02-19 1993-08-25 LEISTRITZ AG &amp; CO. Abgastechnik Exhaust silencer for diesel engines, particularly for commercial vehicles
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EP1276549A1 (en) 2000-04-25 2003-01-22 Emitec Gesellschaft für Emissionstechnologie mbH Method for removing soot particles from an exhaust gas and corresponding collecting element
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US8066951B2 (en) 2000-04-25 2011-11-29 Emitec Gesellschaft Fuer Emissionstechnologie Mbh Method for removing soot particles from an exhaust gas, associated collecting element and system
DE10361791A1 (en) * 2003-12-31 2005-07-28 Volkswagen Ag Exhaust gas cleaning device regenerating method for e.g. Otto engine, involves exhibiting catalyst by device, and pressuring filter with secondary air, when catalyst is desulphurized with hypostoichiometric exhaust gas
US7340888B2 (en) 2005-04-26 2008-03-11 Donaldson Company, Inc. Diesel particulate matter reduction system
US8808418B2 (en) 2006-03-21 2014-08-19 Donaldson Company Low temperature diesel particulate matter reduction system
US7862640B2 (en) 2006-03-21 2011-01-04 Donaldson Company, Inc. Low temperature diesel particulate matter reduction system
DE102008022081A1 (en) * 2008-05-05 2009-11-12 J. Eberspächer GmbH & Co. KG Exhaust gas treatment device
US8336301B2 (en) 2008-05-05 2012-12-25 J. Eberspaecher Gmbh & Co. Kg Exhaust gas treatment unit
US9222392B2 (en) 2010-04-15 2015-12-29 Eberspaecher Exhaust Technology Gmbh & Co. Kg Exhaust gas treatment device
US8763375B2 (en) 2010-08-19 2014-07-01 J. Eberspaecher Gmbh & Co. Kg Exhaust gas cleaning device, exhaust system, removal method
CN104165256A (en) * 2013-05-17 2014-11-26 中国科学院声学研究所 Active sound eliminator for ventilation pipeline system
CN104165255A (en) * 2013-05-17 2014-11-26 中国科学院声学研究所 Active-passive composite silencer for ventilation pipeline
CN104165255B (en) * 2013-05-17 2016-02-03 中国科学院声学研究所 A kind of air pipeline active-passive composite silencing apparatus
CN104165256B (en) * 2013-05-17 2016-02-03 中国科学院声学研究所 A kind of active silencer for air pipeline system
CN105370358A (en) * 2015-11-24 2016-03-02 徐秋苹 Motorcycle exhaust pipe
CN109356686A (en) * 2018-11-05 2019-02-19 卢宝良 Diesel motor exhaust black-smoke purifier

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