Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/031—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 having means for by-passing filters, e.g. when clogged or during cold engine start
• • 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
  • F01N3/04—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust using liquids
  • F01N3/043—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust using liquids without contact between liquid and exhaust gases
  • F01N3/046—Exhaust manifolds with cooling jacket
• • 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
  • F01N3/18—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 methods of operation; Control
  • F01N3/20—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 methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/2053—By-passing catalytic reactors, e.g. to prevent overheating
• • 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
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
  • F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
  • F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus
• • 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
  • F01N2410/00—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
• • 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
  • F01N2410/00—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
  • F01N2410/10—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device for reducing flow resistance, e.g. to obtain more engine power
• • 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
• • 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 present invention relates to a particulate filter trap for a diesel engine.
• the present invention seeks to provide a particulate filter trap in which particles trapped in the filter are continuously burned off without requiring an external energy source. Summary of the invention
• a diesel engine fitted with a filter trap comprising a filter material having embedded therein particles of a catalyst disposed within the exhaust manifold of the diesel engine immediately downstream of the exhaust ports, by-pass channels being included in the filter material to permit part of the gases to be directed for recirculation through the engine without passing through the filter material.
• the invention takes advantage of the fact that the particles will burn in the presence of a catalyst without applying any more heat than is already present in the exhaust gases, provided that the trap is positioned in the path of the gases before they have had the opportunity of cooling down in the exhaust pipe of the engine.
• the exhaust gas pressure will be sufficient to overcome the resistance to flow presented by the filter material, which may for example be a ceramic foam, and the temperature of the gases will be sufficient to enable the trapped particles to be burned in the presence of the catalyst.
• a difficulty presented by placing the filter material near to the exhaust ports is that there is greater risk at low engine speeds of the filter being blocked.
• the back pressure of the filter material may present a problem even when the filter is not blocked and this problem is aggravated, at low engine speeds, in that there is more tendency for particles to be trapped and in that such particles are burnt off less efficiently.
• This process forms a cycle in which increased back pressure increases filter blockage and increased filter blockage results in increased back pressure, and the effect of this positive feedback is that the filter may be blocked very rapidly.
• the filter material in the present invention includes by-pass channels of relatively small cross section to permit part of the gases to be directed for recirculation through the engine without passing through the filter material.
• the filter trap preferably comprises sections located within the individual manifold branches leading to the exhaust port. Such a configuration, apart from catching the exhaust gases at their hottest, has the advantage that the pressure pulses from individual cylinders will be sensed. Thus between pulses, particles will have more time to settle in the trap and their combustion will be improved.
• a water jacket connected in the engine cooling circuit is arranged to cool the section of the exhaust manifold containing the filter trap.
• Such an arrangement offers the advantages of avoiding excessive under bonnet temperatures and of heating the water in the cooling system. It is normally a problem with a diesel engine that its thermal efficiency is so high that the temperature of the cooling circuit is sometimes not sufficient to achieve effective warming of the cab or passenger compartment.
• the heat emitted during the exothermic reaction occurring within the filter trap is used to supplement the heat rejection from the engine to achieve better heater performance and more rapid engine warm up.
• Figure 1 is a section taken along the line I-I in Figure 2 through a manifold incorporating a filter trap of the invention
• Figure 2 is a section taken along the line II-II in Figure 1.
• An exhaust manifold 10 for a four cylinder diesel engine includes a water jacket 22 connected through feed holes 14 and 16 to a coolant passage 18 in the cylinder head 20.
• the manifold 10 is secured by bolts 24 passing through holes 26 onto the side of the engine and mates with the four exhaust ports, of which one is shown in section in Figure 2.
• the manifold has two output connections, as shown in Figure 1, one leading to the down pipe of the exhaust system and the other to the EGR system which recycles the exhaust gases by supplying them through an EGR valve to the intake manifold.
• Within the exhaust manifold there is disposed a ceramic foam filter 12 in the form of a large rectangular block 12a with four projecting cylindrical cores 12b which extend into the individual exhaust ports of the cylinder head.
• the cores 12b have an axial passage 30 intersected by cross bores 32 which lead the exhaust gases into the rectangular block 12a. Additionally, a low gas flow by-pass channel 34 leads from each axial passage 30 directly to the EGR outlet, without the exhaust gases passing through the filter trap.
• the material of the filter trap has embedded on its surfaces particles of a suitable catalyst, such as platinum, applied by techniques known from the manufacture of catalytic converters.
• a suitable catalyst such as platinum
• the presence of the catalyst enables carbon monoxide to react with excess oxygen in the exhaust gases to produce less environmentally harmful carbon dioxide.
• This exothermic reaction also gives off heat which helps to burn off the soot particles collected in the trap.
• the latter reaction is itself exothermic and gives off still more heat.
• the heat from the various chemical reactions taking place in the filter trap is transferred to the water jacket, the coolant in which is circulated by way of a further outlet of the manifold through the heat exchanger of the vehicle heater.
• the exhaust gases pass through the filter material which traps soot particles and burns them off continuously using the heat generated by the reaction of carbon monoxide with excess air in the presence of the catalyst. Because the gases from the different ports are not combined before reaching the filter trap, the latter will experience the individual pressure pulses at the exhaust ports. As a result, higher pressure is available at the peaks of the pressure pulses to overcome to back pressure created by the presence of the filter and in the period between pulses, more time is allowed for the particles to settle and be trapped for combustion in a subsequent cycle.
• the exhaust gases cleaned of particles and with a reduced carbon monoxide content are passed to the exhaust pipe for discharge into the atmosphere.
• the heat transferred to the water jacket of the manifold is not only the heat of the exhaust gases themselves, which in an engine with a conventional manifold would be wasted by being discharged to atmosphere, but also the heat generated by the catalytically initiated exothermic reactions within the filter trap.
• the heat rejected from the engine is therefore increased and used to reduce warm up time and improve comfort within the passenger compartment.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Exhaust-Gas Circulating Devices (AREA)
• Processes For Solid Components From Exhaust (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10678496

Family Applications (1)

Country Status (3)

Families Citing this family (8)

Family Cites Families (7)

• 1990
  • 1990-06-30 GB GB9014602A patent/GB2245506A/en not_active Withdrawn
• 1991
  • 1991-06-21 WO PCT/GB1991/001009 patent/WO1992000443A1/en not_active Application Discontinuation
  • 1991-06-21 EP EP91911638A patent/EP0591180A1/de not_active Ceased

Non-Patent Citations (1)

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