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
  • F01N3/023—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
  • F01N3/0275—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 using electric discharge 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
  • 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
• • 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
  • F01N3/01—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust by means of electric or electrostatic separators

Definitions

• the invention relates to the treatment of pollutant components contained in a gaseous medium and, in particular, to the field of exhaust gas filtering assemblies of an internal combustion engine of a motor vehicle. More particularly, the invention relates to a set of agglomeration and collection of particles contained in the exhaust gas of a motor vehicle internal combustion engine which comprises an electrostatic agglomeration module and a collection module of agglomerated particles.
• the electrostatic agglomeration modules generally use an electric field to cause an attraction of the particles contained in the exhaust gas to a treatment substrate.
• French Patent Application No. 03 12635 which describes an assembly provided with such an electrostatic agglomeration module.
• the agglomeration is carried out by means of an entanglement of gas permeable metal fibers which internally delimit a passage for the circulation of gases and which are capable of allowing the formation of clusters of agglomerated particles.
• This entanglement constitutes an electrode which, together with a wire electrode disposed along the axis of the passageway, creates a first transverse electric field for deflecting the particles carried by the exhaust gases towards the external electrode at which the clusters are trained.
• the clusters of Particles become detached from the entanglement of metal fibers as soon as they reach a size sufficient for the friction forces exerted by the exhaust gases to tear them off.
• the electrostatic agglomeration module is associated with a particle cluster collection module disposed downstream of said agglomeration module, considering the flow direction of the exhaust gases.
• the agglomeration module may comprise internal and external electrodes for diverting, by means of a second electrostatic field created, the clusters of particles obtained in the direction of the external electrode towards elements adapted to collect them.
• a power supply device comprising a plurality of high voltage generators connected in parallel with each other, each of the generators being provided with a step-up transformer, in order to be able to output a high voltage, from a low voltage.
• This device has the disadvantage of being relatively expensive, and offers nothing for a set of agglomeration and collection of particles contained in the exhaust gas.
• the present invention therefore aims to solve these disadvantages by proposing an assembly of agglomeration and collection of particles contained in the exhaust gas of a motor vehicle internal combustion engine that can be properly powered using the electrical network. present on board the vehicle.
• the agglomeration and collection assembly of the particles contained in the exhaust gases of an internal combustion engine of a motor vehicle is provided with at least one electrostatic agglomeration module comprising an internal electrode and a external electrode between which is created a first electric field, the outer electrode being made of a porous material capable of passing the exhaust gases as well as clumps of agglomerated particles during the passage of the exhaust gases through the porous material, and a particle cluster collection module disposed downstream of the agglomeration module, considering the flow direction of the exhaust gases.
• the assembly further comprises a power supply or electrical generation device provided with a single step-up transformer capable of enabling a continuous high voltage supply of the agglomeration module and the collection module.
• the transformer is connected at the input to a DC / AC converter powered by a low voltage electrical source, and connected at the output to at least one AC / DC converter connected to the agglomeration and collection modules.
• the electrical generating device further comprises means for measuring the voltage and / or the current at the output of the DC / AC converter, and a control unit able to drive the DC / AC converter according to the values measured.
• the transformer comprises at least one primary coil and at least two secondary coils, each secondary coil being connected to an AC / DC converter connected to one of said modules.
• the generation device may comprise means for measuring the voltage and / or current at the output of each AC / DC converter, and a control unit able to control the DC / AC converter as a function of at least one of the measured values. .
• At least one of the AC / DC converters consists of a diode.
• the transformer comprises two primary coils connected in series. In another embodiment, the transformer comprises two primary coils connected in parallel.
• the collection module comprises a first electrode and a second electrode extending in a second field. electric, one of said electrodes comprising a surface for receiving agglomerated particles.
• FIG. 1 is a sectional view of a set of agglomeration and collection according to the invention
• FIG. 1 shows alternative embodiments of a supply device of the assembly of agglomeration and collection of Figure 1.
• the agglomeration and particle collection assembly essentially comprises a particulate filter 10 and a collection module 12 of collected particle clusters.
• the particulate filter 10 is constituted by an electrostatic agglomeration module ensuring entrapment and agglomeration of the particles carried by the exhaust gas.
• the collection module 12 is disposed downstream of the agglomeration module 10, considering the flow direction of the exhaust gas, and allows a capture of the agglomerated particles extracted from the agglomeration module 10.
• the agglomeration module 10 comprises an intake duct 2, a collector 4, and an agglomeration unit 3 located between the intake duct 2 and the collector 4.
• the agglomeration unit 3 comprises an external electrode 5 of generally cylindrical shape. This electrode 5 delimits internally an axial passage 6 for the exhaust gas which communicates at one of its ends with the pipe 2.
• the outer electrode 5 comprises radial front surfaces 7 and 8.
• the front surface 7 is in axial contact with a ring 9 for fixing the external electrode 5 to the inlet pipe 2.
• the ring 9 is connected to the ground .
• the external electrode 5 is open on the side of its front surface 7, so that the central passage 6 communicates with the inlet pipe 2.
• the intake pipe 2 comprises an inlet orifice 13 on the opposite side to the outer electrode 5.
• a disk 14 abuts axially by a radial surface 15 against the end surface 8 of the external electrode 5 opposite to the outer electrode 5. the intake pipe 2.
• the agglomeration unit 3 also comprises a central electrode 16 in the form of a rod 17 coaxial with the external electrode 5 and one end 18 of which is plugged into an insulating portion of the disc 14.
• the internal electrode 16 is extends axially from its end 18 beyond the fixing ring 9 being bent to form a radial portion 19 coming out of the inlet pipe 2 through an opening 20.
• An insulator 21 is disposed in the opening 20 to electrically isolate the wall of the intake pipe 2 of the internal electrode 16.
• the radial portion 19 is electrically connected to a power supply device 22.
• the collector 4 comprises a cylindrical envelope 23 which surrounds the external electrode 5.
• the cylindrical envelope 23 extends axially beyond the disc 14. It comprises an inside diameter greater than the outside diameter of the electrode 5, so that there is an empty annular space 24 between the cylindrical envelope 23 and the external electrode 5.
• Said envelope finally communicates, on the opposite side to the intake pipe 2, with a pipe 28 opening into the collection module 12 of the agglomerated particles.
• the particle - laden exhaust gases enter the inlet pipe 2 through the inlet port 13. They then flow into the central passage 6 of the outer electrode 5, which communicates with the pipe. in which they are ionized and the particles they contain electrically charged.
• the disk 14 prevents the axial passage of the exhaust gas. The exhaust gases are then deflected radially and pass through the external electrode 5, which is permeable to gases.
• the external electrode 5 is maintained at a zero potential, the internal electrode 16 being brought to a positive or negative potential.
• the potential difference created between the external electrode 5 and the internal electrode 16 induces the presence of a first electric field in the axial passage
• the internal electrode 16 In order to charge the particles in a suitable manner for their electrostatic agglomeration, it is thus necessary to cause a sufficient electronic avalanche.
• the internal electrode 16 In order to charge the particles in a suitable manner for their electrostatic agglomeration, it is thus necessary to cause a sufficient electronic avalanche.
• the internal electrode 16 In order to charge the particles in a suitable manner for their electrostatic agglomeration, it is thus necessary to cause a sufficient electronic avalanche.
• the internal electrode 16 must therefore be carried, through the electrical generating device
• the increase in the potential at which the internal electrode 16 is carried also has the effect of ionizing a gaseous medium in a larger volume.
• the ionization of the entire volume between the internal and external electrodes 16 requires a large amount of energy.
• an internal electrode 16 In the case of an internal electrode 16 brought to a positive potential, the particles present in the exhaust gases pass through an ionized medium. There is a greater probability, in this case, that a particle encountering an ionized molecule combines to form a positively charged particle.
• An internal electrode 16 allows an ionization of the volume between said electrode and the internal electrode 5 with a low energy input, being brought to a lower potential, for example being between 1 kV and 50 kV.
• the nearly homogeneous electric field in the interelectrode space deflects charged particles that migrate to the porous outer electrode.
• the electric field is heterogeneous only in the vicinity of the two electrodes 16 and 5. When the particles are in the vicinity of the external electrode 16, of the order of 1 mm, the electric field lines converge towards the fibers of said electrode 16 The particles are then precipitated against the fibers by the large local increases in the electric field.
• the majority of the particles reach the electrode from the first row of fibers and almost no depth capture takes place.
• the charged particles deposited on the inner face of the electrode 16 agglomerate by electrostatic interactions and by Van der Waals forces.
• the particle clusters grow to a sufficient size so that the friction forces exerted by the exhaust gases tear them off.
• the clusters of particles enlarge until they are ejected from the porous electrode 16 in the form of agglomerates which are then collected by the collection module 12.
• the size ratio between the particles of the gases The exhaust gas emitted by the engine and the clusters of particles thus collected is from 100 to 1000.
• the majority of the agglomerated particles then have a size greater than 5 ⁇ m.
• the collection module 12 essentially comprises an internal electrode 29, which may be of wired type, and an external electrode 30 of generally cylindrical shape so as to allow the passage of the exhaust gas.
• the electrode 29 extends axially inside the electrode 30 being bent at each of its ends to form two radial portions 31 and 32 coming out of the supply line 28 through two openings 33 and 34.
• Two insulators 35 and 36 are mounted inside the openings 33 and 34 to electrically isolate the electrode 29.
• the electrode 29 is preferably supplied by the device 22 used for biasing the internal electrode 16 of the agglomeration module 10.
• the electrode 30 is connected to ground (not shown).
• the electrode 30 comprises a surface 37 for collecting or collecting agglomerated particles and discs 38 extending radially inwardly from said surface 37, being axially spaced relative to each other.
• a device of the "heating cord" type 39 is disposed at the level of the surface 37 and connected to an electrical control system 40, itself connected to a current source 41 which makes it possible to generate a heating of the deposition of particle clusters and to provoke their combustion.
• a second electric field is created between the inner electrode 29 and the outer electrode 30.
• the power source 41 can supply the heating cord 39 periodically as a function, for example, of the kilometers traveled, of the operating time, or also by way of a probe measuring the quantity of particle cluster stored on the heating cord 39.
• the exhaust gas thus treated is then discharged via line 42.
• 22 generating device or power supply 43 comprises a transformer provided with primary and secondary coils 43a, 43b respectively provided with a number of turns N N 43a and 43 b can be different.
• the primary coil 43a is connected to a DC / AC converter 44, for example an inverter, itself connected to a DC low voltage source 45.
• the source 45 is constituted by the electrical network of the vehicle.
• the secondary coil 43b is connected to a first AC / DC converter 46, for example a rectifier with or without voltage multiplier, connected to the agglomeration module 10 and to the collection module 12.
• a first AC / DC converter 46 for example a rectifier with or without voltage multiplier
• the transformer 43 thus enables the voltage delivered by the source 45 to be raised so as to obtain a desired DC high voltage for the modules 10 and 12.
• the ratio between the number of turns N 43a and N 43b is thus determined. depending on this voltage.
• the electrical generation device 22 is associated with a control unit 47 providing control of the high voltage delivered to the agglomeration and collection modules 10, 12.
• the device 22 comprises a first means 48 for measuring the value of the output voltage of the AC / DC converter 46.
• the control unit 47 is able to drive the DC / AC converter 44 according to the detected measurements. by said measuring means 48.
• the measuring means 48 are advantageousously, the measuring means
• a transformer 49 is provided with a primary coil 49a and first and second secondary coils 49b and 49c. Said primary and secondary coils 49a, 49b, 49c are respectively connected to the DC / AC converter 44, to the first AC / DC converter 46 connected to the collection module 12, and to a second AC / DC converter 50 itself connected to the agglomeration module 10.
• the generation device 22 thus makes it possible to feed the modules 10, 12 either with high voltages of different values or with high voltages of equal values, depending on the number of turns of the coils 49b and 49c.
• the device 22 also comprises a second voltage and / or current measurement means 51 at the output of the AC / DC converter 50 which is connected to the control unit 47 to carry out the functional control of the generation device 22.
• the first measuring means 48 is here connected to the output of the AC / DC converter 46.
• the AC / DC converter 46 is replaced by a diode 52a that can be connected to a voltage limiter 52b itself connected to the collection module 12.
• the replacement of an AC / DC converter continuous diode allows obtaining a device 22 of particularly economical generation.
• a transformer 53 comprises first and second primary and secondary coils 53a to 53d.
• the first and second secondary coils 53c, 53d are respectively connected to the AC / DC converters 50,
• the first and second primary coils are connected to the DC / AC converter 44 and are either connected in series ( Figure 5), or are connected in parallel ( Figure 6).
• the assembly according to the invention thus makes it possible to obtain an agglomeration and a collection of the particles contained in the exhaust gases of the combustion engine of the motor vehicle in a particularly efficient and economical manner by using, for example, the electrical network present on board the vehicle. vehicle.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Processes For Solid Components From Exhaust (AREA)
• Exhaust Gas After Treatment (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2005
  • 2005-07-01 FR FR0507045A patent/FR2887922A1/fr not_active Withdrawn
• 2006
  • 2006-06-09 EP EP06778920A patent/EP1904722A1/de not_active Withdrawn
  • 2006-06-09 WO PCT/FR2006/050542 patent/WO2007003832A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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