Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
  • B01F25/3131—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
  • F01N3/28—Construction of catalytic reactors
  • F01N3/2892—Exhaust flow directors or the like, e.g. upstream of catalytic device
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F2025/91—Direction of flow or arrangement of feed and discharge openings
  • B01F2025/915—Reverse flow, i.e. flow changing substantially 180° in direction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F2025/93—Arrangements, nature or configuration of flow guiding elements
  • B01F2025/931—Flow guiding elements surrounding feed openings, e.g. jet nozzles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/21—Mixing gases with liquids by introducing liquids into gaseous media
  • B01F23/213—Mixing gases with liquids by introducing liquids into gaseous media by spraying or atomising of the liquids
  • B01F23/2132—Mixing gases with liquids by introducing liquids into gaseous media by spraying or atomising of the liquids using nozzles
  • B01F23/21321—High pressure atomization, i.e. the liquid is atomized and sprayed by a jet at high pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/40—Static mixers
  • B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
  • B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
  • B01F25/435—Mixing tubes composed of concentric tubular members
• • 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
  • F01N13/08—Other arrangements or adaptations of exhaust conduits
• • 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
  • F01N2470/00—Structure or shape of gas passages, pipes or tubes
  • F01N2470/08—Gas passages being formed between the walls of an outer shell and an inner chamber
• • 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
  • F01N2470/00—Structure or shape of gas passages, pipes or tubes
  • F01N2470/24—Concentric tubes or tubes being concentric to housing, e.g. telescopically assembled
• • 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
  • F01N2470/00—Structure or shape of gas passages, pipes or tubes
  • F01N2470/30—Tubes with restrictions, i.e. venturi or the like, e.g. for sucking air or measuring mass flow
• • 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
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
• • 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
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/10—Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance
  • F01N2610/102—Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance after addition to exhaust gases, e.g. by a passively or actively heated surface in the exhaust conduit
• • 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
  • F01N3/2066—Selective catalytic reduction [SCR]
• • 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 an arrangement to insert a liquid medium , for example urea, into exhausts from a combustion engine, according to the preamble of patent claim 1 .
• a liquid medium for example urea
• today's motor vehicles are usually equipped with a catalytic converter in the exhaust pipe in order to achieve a catalytic conversion of environmentally harmful exhaust components into less environmentally harmful substances.
• One method used to achieve an effective catalytic conversion is based on injecting a reduction agent into the exhausts upstream of the catalytic converter.
• a reduction substance included in or created by the reduction agent is introduced into the catalytic converter by the exhausts where it is absorbed in active sites in the catalytic converter, which causes an accum ulation of the reduction agent in the catalytic converter.
• the accumulated reduction agent may then react with an exhaust substance for the conversion of this exhaust substance into a substance with less environmental impact.
• SC R Selective Catalytic Reduction
• An SC R-catalyst reduces NO x in the exhausts.
• a reduction agent in the form of urea is usually i njected into the exhausts upstream of the catalytic converter.
• ammonia When urea is injected into the exhausts, am monia is formed , and it is this ammonia which constitutes the reduction agent contributing to the catalytic conversion in the SC R-catalyst.
• the ammonia is accumulated in the catalytic converter by being absorbed in active sites in the catalytic converter and NO x present in the exhausts is converted into nitrogen and water when brought into contact with accumulated am monia at the active sites in the catalytic converter.
• urea When urea is used as a reduction agent, it is injected into the exhaust pipe in the form of a liquid urea solution with the help of an injection element.
• the injection element comprises a nozzle via which the urea solution is injected into the exhaust pipe under pressure, in atomised form as a spray.
• the exhausts During long periods of a diesel engine's operation, the exhausts have a sufficiently high temperature to be able to vaporize the urea solution so that am monia is formed .
• a combustion engine is operated in a consistent manner for a period of time, i.e. during a stationary operating condition, there are no substantial variations in the gas flow, and the urea solution injected into the exhausts will therefore hit essentially the same area of the exhaust pipe during this entire period of time.
• the temperature in this area of the exhaust pipe may be reduced locally to a temperature lower than 1 00 °C, which in turn may lead to the formation of a film of urea solution in this area, which is then pulled along with the exhaust flow. Once this film has been moved a certain distance in the exhaust pipe, the water in the urea solution will boil off due to the hot exhausts. There remains solid urea, slowly evaporating by the heat in the exhaust pipe. If the supply of solid urea is greater than the evaporation , solid urea accumulates inside the exhaust pipe.
• urea lumps may, over time, block an exhaust pipe.
• the objective of the present invention is to achieve an arrangement of the type mentioned above which creates improved possibilities of ensuring a good vaporisation of the injected reduction agent.
• the arrangement according to the invention comprises:
• Said tubular wall has a variable wall thickness seen in the mixing chamber's longitudinal di rection , so that the section of the tubular wal l which is intended to be impacted by said spray of a liquid medium from the injection element has a wall thickness which is greater than the wall thickness of those sections of the tubular wal l which are adjacent to this wall section .
• this wall section becomes capable of taking up and storing a greater amount of heat from the passing exhausts compared to the other, thinner wall sections.
• the thickened wal l section acquires an improved ability to counteract the cooling down caused by the injected medium impacting this section of the wal l.
• the stored heat also contributes to an increased vaporisation of the injected medium impacting the relevant wall section .
• the relevant wall section also acquires an improved heat conducting ability, which means that the cooling action which is caused by the injected medium impacting the wall section is spread over a larger area.
• One embodiment of the invention is characterised by:
• the arrangement comprising an exhaust channel adjacent to the mixing cham ber, which is intended to be perfused by exhausts and extends along the outside of said tubular wall , wherein the exhaust channel is delimited from the mixing chamber by the tubular wall , and - the exhaust channel being delimited in a radial direction outwards by another tubular wall , which is designed to guide the exhausts flowing through the exhaust channel to pass on the outside of said wall section .
• a throttle is arranged in the section of the exhaust channel located on the outside of said wall section, in order to achieve an acceleration in the exhausts flowing through the exhaust channel in this exhaust channel section, so that these flow with an increased speed over the outside of said wall section .
• the heat transfer coefficient with respect to the heat transfer from a flowing gas to a surface increases with increased flow rate of the gas.
• Fig 1 is a schematic longitudinal section through arrangement according to one embodiment of present invention .
• Fig 2 is a section according to the line II-II in Fig 1 .
• FIG 1 -2 an arrangement 1 according to one embodiment of the present invention to introduce a liquid medium into exhausts from a combustion engine is illustrated .
• the arrangement may for example be arranged inside an exhaust pipe upstream of an SC R-catalyst to i ntroduce a liquid reduction agent in the form of urea or ammonia into the exhaust pipe upstream of the SC R- catalyst, or be arranged inside an exhaust after-treatment device to introduce a liquid reduction agent in the form of urea or am monia upstream of an exhaust after-treatment device included in an SC R-catalyst.
• the arrangement 1 comprises a mixing chamber 2 intended to receive exhausts from a combustion engine and to lead these exhausts further in a direction toward an exhaust after-treatment device, for example in the form of an SC R-catalyst.
• the mixing chamber 2 is thus intended to be perfused by exhausts.
• the mixing chamber 2 has an upstream end 4 and a downstream end 5.
• the mixing chamber 2 is delimited in a radial direction outwards by a tubular metal wall 6, extending between the mixing chamber's upstream end 4 and its downstream end 5.
• the mixing chamber 2 has an inlet 7 for receipt of exhausts at its upstream end and an outlet 8 for emission of exhausts at its downstream end .
• the inlet 7 is suitably annular and arranged to extend around the mixing cham ber's central shaft 9.
• the mixing chamber 2 preferably has a circular cross sectional form , as illustrated in Fig 2.
• An injection element 1 0 for injection of the liquid medium is arranged in the centre of the mixing chamber's upstream end 4, to inject the liquid medium in a direction toward the mixing chamber's downstream end 5.
• the injection element 1 0, which may for example comprise an injection nozzle, is arranged to inject the liquid medium into the m ixing chamber 2 under pressure, in an atomised form as a spray 1 1 .
• the tubular wall 6 has a variable wall thickness seen in the mixing chamber's longitudinal direction , so that the section 6a of the tubular wall , which is intended to be impacted by said spray 1 1 of a liquid medium from the injection element 1 0, has a wall thickness which is greater than the wall thickness of the sections 6b of the tubular wall that are adjacent to this wall section 6a.
• the thickened wall section 6a preferably has a thickness which is at least 30% greater, and preferably 1 .5-3 times greater than the thickness of the wall's thinner section 6b.
• the wall's thinner section 6b may for example have a thickness of around 0.5-2 mm .
• the arrangement 1 com prises an exhaust channel 1 2 with an annular cross section, adjacent to the mixing chamber 2 and intended to be perfused by exhausts and extending along the exterior of the tubular wall 6.
• the exhaust channel 1 2 encloses the mixing cham ber 2 and is concentric with the latter, as illustrated in Fig 2.
• the exhaust channel 1 2 and the mixing chamber 2 are delim ited from each other by the tubular wall 6.
• the exhaust channel 1 2 is delimited in a radial di rection inwards by the tubular wall 6 and in a radial direction outwards by another tubular wall 1 3, designed to guide the exhausts flowing through the exhaust channel 1 2 so that they pass on the outside of the thickened wall section 6a.
• a throttle 1 4 is arranged in the section 1 2a of the exhaust channel located on the outside of the thickened wall section 6a, in order to achieve an acceleration of the exhausts flowing through the exhaust channel 1 2 i n this exhaust channel section 1 2a, so that these flow with an increased speed over the outside of said wall section 6a.
• the exhaust channel 1 2 has a cross sectional area which is smaller than the cross sectional area of the section of the exhaust channel which is located upstream of the throttle.
• the exhaust channel 1 2 is arranged downstream of the mixing cham ber 2 and connected to the mixing chamber 2 via a flow reversal element 1 5, arranged to reverse the flow direction of the exhausts flowi ng from the mixing chamber 2, so that these are brought to flow through the exhaust channel 1 2 in a flow direction which is opposite to the flow direction of the exhausts in the mixing chamber 2.
• the flow reversal element 1 5 is arranged opposite the mixing chamber's outlet 8 and equipped with a middle section 1 5a and an annular edge section 1 5b surrounding the middle section 1 5a.
• Said middle section 1 5a, facing the mixing chamber 2 preferably has a convex shape, as illustrated in Fig 1 .
• the spray 1 1 of a liquid medium which is injected into the mixing chamber 2 via the injection element 1 0 comes into contact with exhausts, flowing into the mixing chamber via the mixing chamber's inlet 7 in an essentially symmetric flow around this spray 1 1 .
• the exhausts flowing into the mixing chamber 2 bring along the liquid medium downstream in the mixing chamber. While moving downstream in the mixing chamber 2, the liquid medium spreads into the exhausts and evaporates due to the exhaust heat.
• Liquid medium which is not evaporated impacts the thickened section 6a of the tubular wall 6.
• the liquid medi um which impacts this thickened wall section 6a will be evaporated due to the hot wall surface and the hot exhausts.
• the exhausts are led further to the exhaust channel 1 2.
• the exhausts are accelerated and flow with an increased speed along the outside of the thickened wall section 6a while delivering heat to the same.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Dispersion Chemistry (AREA)
• Exhaust Gas After Treatment (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=50978863

Family Applications (1)

Country Status (6)

Families Citing this family (9)

Family Cites Families (12)

• 2012
  • 2012-12-21 SE SE1251488A patent/SE536832C2/sv unknown
• 2013
  • 2013-12-05 RU RU2015129689A patent/RU2609009C2/ru not_active IP Right Cessation
  • 2013-12-05 KR KR1020157019141A patent/KR20150092337A/ko not_active Application Discontinuation
  • 2013-12-05 BR BR112015014580A patent/BR112015014580A2/pt not_active IP Right Cessation
  • 2013-12-05 WO PCT/SE2013/051456 patent/WO2014098728A1/en active Application Filing
  • 2013-12-05 EP EP13864833.2A patent/EP2935817A4/de not_active Withdrawn

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