FR2884858A1 - Exhaust gas particles e.g. pollutant component, filtering and eliminating device for motor vehicle, has module collecting particles accumulated by particle filter, where potential difference between electrodes produces ionization of gas - Google Patents

Abstract

The device has a collection module (12) that collects particles accumulated by a particle filter which is constituted by an electrostatic accumulation module that traps and accumulates the particles in the exhaust gas of an internal combustion engine. A potential difference created between the inner and outer electrodes induces the presence of an electric field in an axial passage so as to produce a partial or total ionization of the gas existing between the electrodes. A cathode (30) has a cover (33) and a bottom (32) for the collection of accumulated particles.

Description

Device for filtering and eliminating particles contained in

  exhaust gases improving the capture of particles.

  The invention relates to the treatment of polluting components contained in a gaseous medium and, in particular, to the field of devices for filtering the exhaust gases of an internal combustion engine.

  More particularly, the invention relates to a device for filtering and removing particles contained in the exhaust gas of a motor vehicle internal combustion engine which comprises an electrostatic agglomeration module and a recovery module of particles agglomerated by the electrostatic filtering device.

  Electrostatic filtering modules generally use an electric field to cause an attraction of the electrically charged particles to a substrate on which the particles are attached.

  In this respect reference may be made to the patent application WO 00/02549 which describes an electrostatic particle filtering device comprising a corona-type electrostatic filter comprising a cylindrical cage inside which the exhaust gases enter in order to of their filtering.

  Reference can also be made to US Pat. No. 4,478,613, which describes another type of particle filtering device comprising an electrostatic filter and a mechanical particle separator.

  The electrostatic filter comprises a tubular element having one of its closed ends, inside which there is a stack of disks concentric with respect to the axis of the tube. The tube is maintained at a zero potential while the discs are connected to a negative potential. The exhaust gases enter the tube through an opening and flow axially to exit through an opposite opening on the side. Discs carried at a negative potential constitute an emissive structure for generating an electric field between the inner surface of the tube and the discs. The exhaust gases pass through this field, and the particles contained in the exhaust gases are charged by ionic drift. The particles thus charged move radially under the effect of the electric field created to go to be deposited on the inner face of the tube where they accumulate in layers.

  Similarly, French Patent Application No. 02 06304 also describes an exhaust gas filtering device provided with such an electrostatic agglomeration module. In this device, the filtering is carried out by means of an entanglement of gas-permeable metal fibers which internally delimit a passage for the gases and which are capable of mechanically retaining particles. This entanglement also constitutes an electrode which, together with a wire electrode disposed along the axis of the passage, creates a transverse electric field sufficient to deflect the particles carried by the exhaust gases to the external electrode at which they are located. agglomerate.

  But it is then necessary to eliminate the trapped particles.

  This is usually achieved by using a particle cluster recovery module that collects and stores the clusters of particles that break off as soon as they reach a size sufficient for the friction and pressure forces exerted by the gases. exhaust snatch them.

  In view of the foregoing, the object of the invention is to improve the recovery of clusters of agglomerated particles from the electrostatic agglomeration module.

  The subject of the invention is therefore a device for filtering and eliminating particles contained in the exhaust gases of an internal combustion engine of a motor vehicle, comprising an electrostatic agglomeration module comprising an internal electrode and an external electrode. between which is created a first electric field, the outer electrode being made of porous material capable of passing the exhaust gas as well as clusters of particles agglomerated during the passage of the exhaust gas through the porous material, and a particle cluster recovery module arranged downstream of the agglomeration module, considering the flow direction of the exhaust gas.

  The recovery module comprises at least a first anode electrode and at least one second cathode electrode extending in a second transverse electric field, the cathode electrode comprising a surface for receiving agglomerated particles deflected by the action of the field. created between the first electrode and the second electrode which opens into a particle receiving volume.

  In one embodiment, the plate is covered with a cover provided with passages distributed along the cathode.

  However, in order to easily recover the particles not trapped by the upstream passages, the passage located at the downstream end of the cartridge has increased dimensions.

  In one embodiment of the filtering device according to the invention, the receiving surface is arranged horizontally, the electric field being oriented vertically so as to deflect the masses of particles in the direction of gravity towards the cathode.

  According to yet another embodiment, possibly combinable with the embodiment defined above, the cathode comprises, on either side of said receiving surface, two agglomerated particle receiving volumes each closed by lids provided with passages. distributed along the cathode so that the downstream passage has increased dimensions, each receiving volume of the particles being associated with a respective anode electrode.

  In this case, the anodes and the cathode can be arranged vertically and the electric field oriented horizontally.

  According to yet another characteristic of the invention, the electrodes of the agglomeration module and the electrodes of the recovery module are fed by the same power source.

  According to yet another embodiment, the plate may be provided with a peripheral rim.

  According to yet another variant, possibly combinable with the previously mentioned embodiments, the recovery module further comprises a storage volume of particle clusters to which the clusters of particles recovered by the cathode at the outlet of said passage are directed.

  According to yet another characteristic of the invention, the cover or lids each delimit with said plate a duct in which circulates a gas forcing the clusters of particles to the storage volume.

  In order to improve the capacity of this storage volume, the ducts are each provided with curved wall elements forming obstacles against which clusters of particles collide. However, these wall elements are preferably carried to the potential of the cathode.

  For example, the storage volume is constituted by the internal volume of a chamber whose wall is made of a filtering foam.

  It is also possible to provide the bottom of the storage volume with a filtering coating.

  According to another variant, the bottom of the storage volume is funnel-shaped and has an outlet port for particle clusters provided with a filter.

  To eliminate the clusters of particles recovered by the recovery module, the second electrode may comprise a downstream rim in which are made openings provided with a filter.

  In the various embodiments mentioned above, the recovery module advantageously comprises means for regenerating the mass of particles stored in the storage volume. These regeneration means may be thermal regeneration means or, alternatively, regeneration means by hydrogen oxidation.

  It is also possible, in a variant, to use a suction duct for the agglomerated particles and stored in the storage volume connected upstream of a compressor of the engine intake circuit.

  Other objects, features and advantages of the invention will appear on reading the following description, given solely by way of nonlimiting example, and with reference to the accompanying drawings, in which: FIG. 1 is a sectional view of FIG. an electrostatic agglomeration module of a particle filtering and removal device according to the invention; - Figure 2 is a schematic sectional view of a particle cluster recovery module to be placed downstream of the agglomeration module of Figure 1; FIG. 3 illustrates a second embodiment of a particle cluster recovery module according to the invention; FIG. 4 illustrates another embodiment of a recovery module according to the invention; FIG. 5 illustrates yet another alternative embodiment of a particle cluster recovery module according to the invention; FIG. 6 illustrates yet another embodiment of a particle cluster recovery module in which the particles are stored in a storage volume; FIG. 7 illustrates an embodiment in which the cathode is provided with curved wall elements; FIG. 8 illustrates an embodiment of the recovery module in which the storage volume is constituted by the internal volume of a chamber made from a filtering foam; FIG. 9 illustrates yet another embodiment of the particle recovery module according to which the bottom of the storage volume comprises a filtering coating; FIG. 10 is a schematic view of another embodiment of a recovery module in which the bottom of the storage volume has a funnel shape; - Figure 11 illustrates yet another mode of collection of particle clusters; FIG. 12 is a side view of another embodiment of a particle cluster recovery module according to which clusters of particles are recovered within the cathode; FIG. 13 is a front view of the module of FIG. 12; and FIG. 14 illustrates a mode of elimination of the clusters of particles recovered by a recovery module according to the invention.

  With reference to FIGS. 1 and 2, an exhaust gas filtering system of an internal combustion engine of a motor vehicle will first be described.

  This filtering system essentially comprises a particle filter 10 represented in FIG. 1 and a module 12 for recovering clumps of particles agglomerated by the particle filter 10, visible in FIG. 2. The particle filter 10 is constituted by a electrostatic agglomeration module ensuring entrapment and agglomeration of the particles carried by the exhaust gas. The recovery module 12 is disposed downstream of the module 10 and opens into a gas evacuation pipe (not shown) and ensures capture and removal of the agglomerated particles extracted from the agglomeration module 10.

  As can be seen in FIG. 1, the electrostatic agglomeration module comprises an intake duct 2, a collector 4 and a filter unit 3 situated between the intake duct 2 and the collector 4.

  The filter unit 3 comprises an external electrode 5 of generally cylindrical shape. This electrode 5 delimits internally an axial passage 6 for the gases which communicates at one of its ends with the pipe 2.

  The outer electrode 5 comprises mutually opposite end surfaces 7 and 8. The end end surface 7 is in axial contact with a ring 9 for fixing the external electrode 5 to the inlet pipe 2. The crown 9 is connected to the ground.

  The external electrode 5 is open on the side of its front end surface 7, so that the central passage 6 communicates with the intake 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 intake pipe 2. The disk 14 axially closes the central passage 7 on the opposite side to the intake pipe 2.

  The filter 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 extends axially from its end 18 beyond the fixing ring 9 being bent to form a radial portion 19 radially 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 voltage source 22.

  The collector 4 is disposed in 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 external diameter of the external electrode 5, so that there is an empty annular space 24 between the cylindrical envelope 23 and the external electrode 5. It finally communicates on the opposite side to the intake pipe 2 with a pipe 28 opening into the module 12 for collecting the agglomerated particles.

  Indeed, in operation, the particulate-laden exhaust gases enter the intake pipe 2 through the inlet port 13. They flow into the central passage 6 of the external electrode 5, which communicates with the intake pipe 2, in which they are ionized and the electrically charged particles.

  As is conceivable, the end disc 14 prevents the axial passage of the exhaust gas. The exhaust gases are then deflected radially and pass through the external electrodes 5 which is gas permeable.

  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 and internal electrode 5 induces the presence of an electric field in the axial passage 6. If this electric field has a sufficient intensity, in particular in the very near vicinity of the internal electrode 16, a partial or total ionization of the gases, or medium, occurs between the internal and external electrodes 16 and 5.

  In the case of an internal electrode 16 brought to a negative potential, the particles present in the exhaust gases are mainly charged by collision and combination with free electrons. Given the low concentration of particles in the exhaust gas, the probability that an electron moving rapidly from the inner electrode 16 to the outer electrode 5 strikes a particle and combines with the latter is low. In order to properly charge the particles for electrostatic filtering, it is necessary to provide sufficient electronic avalanche. The internal electrode 16 must therefore be brought to a high potential, for example between 50 and 150 kV.

  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. However, the ionization of the entire volume between the inner 18 and outer 5 electrodes requires considerable energy.

  In the case of an internal electrode 18 brought to a positive potential, the particles present in the exhaust gas pass through an ionized medium. There is a greater likelihood, in this case, that a particle encounters an ionized molecule and combines to form a positively charged particle. A positive internal electrode 16 allows an ionization of the volume between the internal electrode 16 and the external electrode 5 with a low energy input, being brought to a lower positive potential, for example between 1 kV and 50 kV.

  The quasi-homogeneous electric field in the inter-electrode space deflects the charged particles that migrate to the porous electrode. The electric field is heterogeneous only near the two electrodes. When the particles are in the vicinity of the porous electrode, of the order of 1 mm, the electric field lines converge towards the fibers of the porous electrode. The particles are then precipitated against the fibers by the large local increases in the electric field. Since the electric field is zero inside the porous electrode and its developed surface is small, the majority of particles reaches 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 agglomerate by electrostatic interactions and by Van der Waals forces. The particle clusters then grow to a size sufficient for the friction forces exerted by the exhaust gases tear them. The particle clusters grow to ejection out of the porous electrode in the form of agglomerates.

  By way of example, the size ratio between the particles of the exhaust gases emitted by the engine and the clusters of particles thus recovered is from 10 to 100.

  Referring now to FIG. 2, the recovery module 12 essentially comprises a cathode 30, for example connected to ground, and an anode 31 preferably powered by the voltage source 22 used to bias the internal electrode 16 of the module. 'agglomeration.

  In the embodiment illustrated in FIG. 2, the cathode 30 has a hollow structure and has a bottom 32 constituting a surface for collecting agglomerated particles and a cover 33 provided with passages 34 made for example in the form of transverse slots distributed over the along the cathode 30 from its upstream end 35 to its downstream end 36. Note however that the slot 34 located in the vicinity of the downstream end 36 has increased dimensions.

  In operation, an electric field El is created between the anode and the cathode at the full part of the cover, while a lower electric field E2 is created at the location of the passages 34. As it is conceived under the action of this electric field, the incident particles are deflected and attracted to the cathode. Part of the clusters of particles arrive directly on the passages and are therefore imprisoned in the internal volume of the cathode. Another part of the particle clumps hit the lid and are again driven by the incident gas flow. However, they are again subjected to electric forces and thus attracted against the wall to be either directly trapped in the internal volume of the cathode 30, or again re-entrained by the incident flow. However, the last passage located in the vicinity of the downstream end 36 of the cathode, of increased dimensions, makes it possible to trap the particles still conveyed by the incident gas flow.

  According to another embodiment visible in FIG. 3, the cathode 30 is devoid of a cover and consists essentially only of a particle recovery plate 32 provided with a peripheral rim 37.

  Note however that the embodiment shown in Figure 2 is advantageous insofar as the electric field El at the location of the solid areas of the cover is greater than the electric field obtained with the embodiment of Figure 3. Another Advantage associated with the use of the cover 33 is to avoid aerodynamic recirculation in the particle recovery volume that tends to expel the previously trapped particles.

  It should also be noted that the particles tend to stick to the walls of the cathode by electrostatic and van der Waals forces.

  Finally, it will be noted that in order to obtain a capture of the particles over as small a distance as possible, the distance between the cathode 30 and the anode 31 must be as small as possible. However, this distance essentially depends on the characteristics of the gases to be captured as well as the available potential and the value of the breakdown field for the gas in question. This leads to a value of a few millimeters or of the order of a centimeter. Therefore, it will be advantageous to provide several identical particle recovery cells arranged in parallel.

  Preferably, in order to facilitate the trapping of the particles, the cathode is positioned horizontally and the anode is positioned relative to the cathode so that the electric field created between the electrodes 30 and 31 act on the particle clusters in the direction of gravity.

  According to another embodiment shown in FIG. 4, in which the flow of gas and clusters of incident particles is treated according to several recovery cells arranged in parallel, these cells are formed using a cathode 30 arranged between two anodes 31. and 31 '. In this embodiment, the cathode 30 essentially consists of a base plate 32 provided with a peripheral wall 37 and delimiting, on either side of the plate 32, two volumes of particle recovery V and V ' .

  In this case, as previously described with reference to FIG. 2, the volumes V and V 'are closed by two covers 33 and 33' provided with passages 34 and 34 '.

  As in the embodiment previously described (FIG. 2), the whole of the cathode is positioned at ground, while the anodes 31 and 31 'are connected to the voltage source 22 (FIG. 1). For each recovery volume V and V ', a behavior similar to the behavior of the cathode described with reference to FIG. 2 is then obtained.

  In the arrangement illustrated in Figure 4, the anodes and the cathode are arranged horizontally, one above the other. In particular, the anode 31 'is disposed under the cathode 30. Also, the attraction of gravity, which tends to attract the particles in the volume V, opposes, on the contrary, the deflection of the particles which circulate between the cathode 30 and the anode 31 '.

  In order to avoid a negative action of the weight of the particle clusters, a rotation of 90 of the recovery module is carried out, so as to position the cathode on the one hand and the anodes 31 and 31 ', on the other hand, so as to vertical (Figure 5). According to this arrangement, the electric fields created in the recovery module extend horizontally. The effects of gravity are then ineffective. For example, it is possible to position several identical cells to the cell visible in FIG. 5, side by side. Note also that, alternatively, the bottom of the cathode, that is to say located in the lower part of Figure 5, can be opened to create a vacuum to improve the capture of clusters of particles.

  In particular, as can be seen in FIG. 6, according to which several cells identical to the cell of FIG. 5 are arranged side by side, the cathodes can, in their bottom, open into a volume of recovery of the particles V ".

  It can be seen in this figure 6 that, in this embodiment, the volume extending between a base plate 32 and two lateral covers 33 and 33 'of the cathode constitute passages P to which the particle clusters migrate after have been attracted to the cathode under the action of the inter-electrode electric field, and in particular, after being trapped through the passages of the side covers of the cathode 30. These passages P open into the common volume V ".

  In this embodiment, however, the base plate 32 may, as shown in FIG. 7, be omitted.

  As indicated above, in order to facilitate the migration of trapped particle clusters to the recovery volume V ", the recovery module can be arranged vertically so as to solicit the clusters of particles trapped to the volume V" by gravity. However, it will also be possible to envisage transporting the particles by means of a secondary gas flow, as indicated by the arrows f.

  It should be noted, however, that the use of such a gas flow is advantageous insofar as it makes it possible to annihilate at least in part the electrostatic forces or the Van der Waals forces consisting in keeping the particle clusters against the cathode.

  Note also that the volume V "used for the recovery of particle clusters can be increased by increasing its height.

  However, if the density of the particle clusters is too low, the volume to be stored may become too large or its emptying frequency too high.

  To overcome this drawback, as shown in FIG. 7, the cathode is provided with wall elements forming curved blades 38 at the potential of the cathode extending alternately from one of the side walls 33 or 33 'to a middle portion of the cathode so as to create claw-like obstacles disturbing the flow of the particle clusters and the secondary gas flow.

  In particular, as seen in this FIG. 7, the particle clusters adopt a relatively chaotic trajectory favoring collisions of the clusters of particles with these claws. These shocks tend to break the particle clusters to make them less porous, that is to say denser and thus limit the volume necessary for their storage.

  According to yet another embodiment visible in Figure 8, the cathode can lead into a treatment volume V "defined by a chamber 39 whose wall is made of foam or a suitable filter material.

  As in the embodiment described above, the transfer of clusters of trapped particles can be carried out either by gravity or, in a complementary manner, by using a transport gas stream (arrow f ').

  Note however that in this embodiment, the chamber defined by the wall 39 constitutes a treatment chamber for the removal of particles. Also, the volume V "is much smaller than the volume V 'used for the storage of the particles, for it is, for example, to carry out a subsequent treatment of the treatment chamber in order to raise its temperature up to Therefore, it is desirable in this case to concentrate the particles in a small volume in order to increase the combustion efficiency.

  As will be recalled later, various regeneration techniques can be used for this purpose.

  It is also possible, as can be seen in FIG. 9, to provide, in the bottom of the recovery volume V "(FIG. 6), a foam coating 40 or a suitable filter support forming a carpet making it possible to trap the clusters of However, in this embodiment, the particles are scattered over the entire surface of the foam.

  According to another variant, visible in FIG. 10, in order to concentrate the clusters of particles trapped in a restricted volume, the bottom 41 of the recovery volume V "has a funnel shape and comprises in the central part a neck 42 on which is placed in a foam or a filter medium (not shown) It should be noted that in this case, when using several cells arranged in parallel, the collection volume V "can be common for all the cells and comprise several necks 42 provided with each of a filter element for the recovery of particle clusters.

  According to yet another variant, shown in FIG. 11, the recovery volume V "is separated into two recovery chambers 43 and 44 towards which the cathodes open, placed one above the recovery module and the other In this case, the transport of the particle clusters by the secondary gas flow is improved.

  In this case, the aggregates are collected by placing a filter element, for example a foam or a suitable filter at the outlet of the cathodes, in the chambers 43 and 44.

  Finally, according to yet another embodiment illustrated in Figure 12, which illustrates a side view of a hollow cathode and in Figure 13, which illustrates a front view of the cathode of Figure 12 on the output side flow, the capture of particle clusters intervenes in the hollow cathode. A secondary flow is then directed towards the downstream vertical wall 36 of the hollow cathode in which openings 45 and 46 are created, for example arranged in the upper part and in the lower part of the vertical wall, these openings being covered with a filter support .

  In the different embodiments, when the storage volume of the particles, and in particular, the filter support is charged with particles, a regeneration phase is carried out in order to eliminate the clusters of trapped particles. For this purpose, provision may be made to provide the filter support with heating cords with a square, rectangular or circular section capable of sustaining the combustion of the trapped particles.

  It should be noted that, since the flow rate of the gas stream circulating in the recovery volume is lower than the main exhaust flow, this regeneration system generates little energy loss and makes it possible to obtain optimized energy efficiency.

  It is also possible, alternatively, to use hydrogen regeneration. Indeed, hydrogen passing through an oxidation catalyst can cause a significant increase in the temperature of the exhaust gas when it is introduced in sufficient quantity. An implementation of this regeneration technique may then consist in impregnating the filter support with a precious metal catalyst from the hydrogen oxidation reaction and injecting the hydrogen slightly upstream thereof. A second possibility is to place in front of the recovery module an oxidation catalyst.

  According to yet another variant, shown in Figure 14, the recovery volume V "is connected to the engine intake circuit by means of a pipe 47 so that the particle clusters are sucked into the combustion chambers of the engine. It will be noted that this embodiment, in which the vacuum existing upstream of the compressor permits suction of the particles stored in the volume V ", makes it possible to limit the cost of combustion insofar as it does not require the provision of a filter support. in the recovery volume V "and does not require additional energy input for the combustion of particle clusters This solution can also be combined with all the embodiments described above.

Claims (20)

  A device for filtering and removing particles contained in an exhaust gas of an internal combustion engine of a motor vehicle, comprising an electrostatic filtering module (10) having an internal electrode (16) and an external electrode ( 5) between which is created a first electric field, the outer electrode being made of porous material capable of passing the exhaust gas as well as clusters of particles agglomerated during the passage of the exhaust gas through the porous material, and a module (12) for recovering the clusters of particles arranged downstream of the agglomeration module, considering the flow direction of the exhaust gases, characterized in that the recovery module (12) comprises at least a first electrode Anode (31,31 ') and at least one second cathode electrode (32) extending into a second transverse electric field, the cathode electrode ode comprising a surface (32) for receiving agglomerated particles deflected under the action of an electric field formed between the first and second electrodes which opens into a particle receiving volume.   2. Device according to claim 1, characterized in that the plate is covered with a cover (33, 33 ') provided with passages (34, 34') distributed along the cathode.   3. Device according to claim 2, characterized in that the passage located at the downstream end of the cartridge has increased dimensions.   4. Device according to any one of claims 1 to 3, characterized in that said receiving surface (32) is disposed horizontally and in that the electric field is oriented vertically so as to deflect the clusters of particles in the direction of gravity towards the cathode.   5. Device according to claim 1, characterized in that the cathode comprises, on either side of said receiving surface (32), two volumes (V, V ') for receiving agglomerated particles each closed by covers ( 33, 33 ') provided with passages (34, 34') distributed along the cathode so that the downstream passage has increased dimensions, each receiving volume of the particles being associated with an electrode (31, 31 ') forming anode respectively.   6. Device according to claim 5, characterized in that the anodes and the cathode are arranged vertically and the electric field is oriented horizontally.   7. Device according to any one of claims 1 to 6, characterized in that the electrodes of the agglomeration module and the electrodes of the recovery module are fed by the same voltage supply source (22).   8. Device according to claim 1, characterized in that the plate is provided with a peripheral rim (37).   9. Device according to any one of claims 1 to 8, characterized in that the recovery module further comprises a volume (V ") for storage of particle clusters to which are directed the clusters of particles recovered by the cathode. output of said passage.   10. Device according to claim 9, characterized in that the cover or lids each delimit with said plate a conduit in which circulates a gas forcing the particle clusters to the storage volume (V ").   11. Device according to claim 10, characterized in that the ducts are each provided with curved wall elements (38) forming obstacles against which collide clusters of particles.   12. Device according to claim 11, characterized in that the wall elements (38) are brought to the potential of the cathode.   13. Device according to any one of claims 9 to 12, characterized in that the storage volume is constituted by the internal volume of a chamber (39) whose wall is made of a filter foam.   14. Device according to any one of claims 9 to 13, characterized in that the bottom of the storage volume comprises a filter coating (40).   15. Device according to any one of claims 9 to 12, characterized in that the bottom of the storage volume has a funnel-shaped and comprises an orifice (42) for output of particle clusters provided with a filter.   16. Device according to any one of claims 2 to 8, characterized in that the second electrode comprises a downstream flange (36) in which are formed openings provided with a filter.   17. Device according to any one of claims 9 to 16, characterized in that the recovery module comprises means for regenerating the mass of particles stored in the storage volume.   18. Device according to any one of claims 9 to 17, characterized in that the regeneration means are thermal regeneration means.   19. Device according to any one of claims 9 to 17, characterized in that the regeneration means comprise regeneration means by hydrogen oxidation.   20. Device according to any one of claims 13 and 19, characterized in that it comprises a duct (47) suction agglomerated particles stored in the storage volume connected upstream of a compressor of the intake circuit of the motor.