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
  • F01N3/08—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]
• • 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
• • 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
  • B01F25/314—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced at the circumference of the conduit
  • B01F25/3141—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced at the circumference of the conduit with additional mixing means other than injector mixers
• • 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
  • B01F25/421—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 by moving the components in a convoluted or labyrinthine path
• • 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
  • B01F25/421—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 by moving the components in a convoluted or labyrinthine path
  • B01F25/423—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 by moving the components in a convoluted or labyrinthine path by means of elements placed in the receptacle for moving or guiding the components
  • B01F25/4231—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 by moving the components in a convoluted or labyrinthine path by means of elements placed in the receptacle for moving or guiding the components using baffles
• • 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
  • B01F25/45—Mixers in which the materials to be mixed are pressed together through orifices or interstitial spaces, e.g. between beads
• • 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
  • B01F25/45—Mixers in which the materials to be mixed are pressed together through orifices or interstitial spaces, e.g. between beads
  • B01F25/452—Mixers in which the materials to be mixed are pressed together through orifices or interstitial spaces, e.g. between beads characterised by elements provided with orifices or interstitial spaces
  • B01F25/4521—Mixers in which the materials to be mixed are pressed together through orifices or interstitial spaces, e.g. between beads characterised by elements provided with orifices or interstitial spaces the components being pressed through orifices in elements, e.g. flat plates or cylinders, which obstruct the whole diameter of the tube
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
  • F01N2240/20—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a flow director or deflector
• • 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
  • F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel
• • 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
• • 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 apparatus for mixing a liquid medium into a gaseous medium flowing through an exhaust pipe from an internal combustion engine, which liquid medium is supplied to the exhaust pipe with varied mass flow via an injector nozzle directed into the exhaust pipe.
• mixers for mixing liquid, for example a reducing agent such as urea, into the exhaust gases of the engine so as, through vaporization and mixing, to produce a more homogenous gas stream to a SCR catalyzer placed downstream of the mixer.
• a reducing agent such as urea
• One problem with diesel engines in heavy-duty vehicles is that the supply of reducing agent must be accurately matched to the varying operating conditions of the engine, i.e. principally to the variations in the exhaust flow.
• the vaporization/mixing-in may sometimes fail to work perfectly, in which case liquid in droplet form can reach and move downstream along the walls of the exhaust pipe until vaporization takes place.
• a recognized solution to the problem is to fit a plurality of turbulence-creating devices in the exhaust pipe, e.g. in the form of perforated plates or wings which produce a deflection of the gas flow, thereby increasing the flow time and hence the vaporization. Unfortunately, this gives rise to an increased fall in pressure in the exhaust line, which adversely affects the breathing of the engine .
• One object of the invention is therefore to produce a mixing apparatus which is simple and effective with low fall in pressure and good mixing capability.
• the apparatus according to the invention is characterized in that the exhaust pipe has a mixer placed downstream of the injector nozzle and a flow path disposed parallel thereto and extending through a perforated surface.
• This configuration of the mixing apparatus allows a smaller mass flow, associated with low rev speeds, to pass freely in the exhaust pipe past the mixer. As the mass flows increase, the mixer will gradually force a larger share of the flow through the parallel flow path, which increases the vaporization and additionally produces the parallel flow comprising turbulence and mixing of the exhaust gases when it is reunited with the main flow.
• Fig. 1 illustrates the placement of an injection nozzle on an exhaust pipe
• Fig. 2 shows in broken view a longitudinal section through an apparatus according to the invention.
• Figure 1 shows a first part-portion 10 of an exhaust pipe connected to an internal combustion engine, which part-portion is provided with an injector 11 for injecting liquid into the exhaust stream.
• the liquid can be constituted, for example, by urea or fuel.
• the pipe expediently has a circular cross section and is delimited against the environment by means of an outer wall 12.
• Arrows 13 illustrate the exhaust flow in the pipe.
• the injector 11 has a spray direction illustrated by the dash-dot line 14, but as a result of the exhaust flow directed from left to right in figure 1 the liquid droplets will be sprayed into the exhaust pipe in the form of a cone, as illustrated by the lines 14a.
• the internal combustion engine can be constituted, for example, by a diesel engine operating at varied speed for the propulsion of a heavy-duty vehicle.
• a second part-portion 15 of the exhaust pipe is shown in figure 2 and is situated downstream of the first part- portion 10 comprising the injector 11.
• a mixer which, as shown in figure 2, can be constituted by a flat plate 16 mounted transversely to the flow direction, or by a mixer suitably configured in a known manner.
• the plate 16 is shown with perforations 17 in the vicinity of the pipe wall 12.
• a principal purpose of the mixer is to create mixing in the exhaust pipe. This creates a fall in pressure, which is exploited in the apparatus according to the invention.
• a widened pipe portion 18 is disposed in the region of the plate 16, and the pipe wall 10 is provided with perforations 19 into the widened portion 18, upstream and downstream of the plate 16.
• the pipe portion 18 hence forms a parallel flow path extending past the plate 16. Low exhaust flows can pass freely past the plate 16 with intended mixing-in/vaporization of the injected liquid. When the speed of the internal combustion engine increases, the flow through the exhaust pipe also increases, whereupon the quantity of liquid supplied via the injector 11 is adjusted to the increasing gas flow.
• the plate 16 When the internal combustion engine is operating in its upper load range, the plate 16 creates a large flow resistance, whereupon a part of the exhaust flow will travel past the plate via the parallel flow path formed by the pipe portion 18. Liquid droplets which have not had time to vaporize will follow the pipe wall 10 and pass through the perforations 19, whereby the liquid droplets are given increased opportunity to vaporize. Moreover, an effective mixing of the exhaust flow takes place downstream of the plate 16 when the parallel flow is reunited with the main flow.

Landscapes

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

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

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Citations (1)

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• 2005
  • 2005-03-08 JP JP2008500662A patent/JP2008533358A/ja not_active Withdrawn
  • 2005-03-08 BR BRPI0520098-9A patent/BRPI0520098A2/pt not_active IP Right Cessation
  • 2005-03-08 WO PCT/SE2005/000341 patent/WO2006096098A1/en active Application Filing
  • 2005-03-08 EP EP05722191A patent/EP1859130A1/de not_active Withdrawn
  • 2005-03-08 CN CNA2005800482906A patent/CN101124390A/zh active Pending
  • 2005-03-08 US US11/813,597 patent/US20080163616A1/en not_active Abandoned

Patent Citations (1)

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