EP1899073B1 - Device for electrostatic precipitation of charged particles carried in an air stream - Google Patents

Abstract

The invention concerns a device (6) for collecting by electrostatic precipitation pre-charged particles carried in an air stream (14). Said device (6) comprises at least two electrodes (7, 8, 18) arranged in the air stream, said electrodes (7, 8, 18) being respectively connected to the earth (9) and to a terminal (10) of a polarized source (11). The electrodes (7, 8, 18) each consist of a wall (12) comprising holes (15), said wall (12) being arranged transversely to the air stream (14). Flanges (13) are provided at one of the surfaces of the wall (12) by being oriented parallel to the air stream (14). The wall (12) and the flanges (13) form a single unit.

Description

Technical Field of the Invention

The present invention is in the field of air treatment devices circulating through an installation, such as a ventilation, heating and / or air conditioning installation, in particular for a motor vehicle. It relates to a device for electrostatic precipitation of particles previously charged and conveyed in a flow of air circulating inside such an installation.

State of the art

Electrostatic devices are known equipment equipping an installation inside which circulates a flow of air. These devices are likely to be used to sanitize the air circulating inside a ventilation, heating and / or air conditioning, especially for a motor vehicle. Such apparatuses are organized to retain particles present in the airflow, such as particles of dust, smoke or the like. These devices include a device for electrically charging particles in the air flow, with a charged particle collection device. The collection device is placed in the airstream downstream of the charging device, to retain by electrostatic precipitation the previously charged particles.

The charging device is for example of the corona type and comprises a pair of electrodes respectively connected to one of the terminals of a polarized power source. The particles present in the air flow circulate between the electrodes which deliver a high voltage discharge, indifferently positive or negative. This discharge produces ions that collide with the particles and charge them electrically.

The collection device consists for example of a non-woven fiber filter, such as a felt, whose fibers are charged with a polarity opposite to that applied to the particles by the charging device, to cause their precipitation on the fibers. fibers: A disadvantage relating to such a collection device lies in the weakening of the fiber load, which decreases as the filter retains the particles. This type of collection device has a durability and insufficient efficiency.

To remedy this drawback, it has been proposed to arrange the filter between two electrodes for recharging the fibers. However, the filter is quickly clogged, which induces aeraulic losses, and affects the efficiency and durability of the device.

It was proposed by the documents GB1559629 (NISSAN MOTOR), JP6247139 (ZEXEL CORP), JP62122820 (NISSAN MOTOR) and US4166729 (US NAVY) to organize the collection device from a plurality of electrodes shaped into plates, which are arranged parallel to each other and whose general plane is oriented parallel to the air flow. Typically, such a collection device comprises several tens of plates spaced from each other by a distance of the order of a few millimeters. The plates are alternately connected to ground and the terminal of a power source of polarity reversed to that applied to the particles by the charging device. The charged particles conveyed in the air flow are attracted and then retained on the surface of the plates connected to the terminal of said source.

A problem to be solved lies in the organization of the collection device which must allow its rapid production and low cost, without affecting its durability or its effectiveness, and which must be of limited size. More particularly, the collection device must be made from a small number of parts to reduce its costs of obtaining and mounting. The positioning of the electrodes must be precise to avoid discharges between them. This accuracy must be obtained in a simple way to not increase the complexity of the device, the number of parts or the difficulty of its assembly. In addition, the electrical connection of the electrodes must be achieved in a simple manner, limiting the necessary wiring.

Document EP 0 550 040 discloses an electrostatic precipitator according to the preamble of claim 1 and the corresponding method of claim 21.

Object of the invention

The object of the present invention is to provide a collection device by electrostatic precipitation of particles previously charged and conveyed in an air flow, this device being intended to equip an installation through which circulates the air flow. The present invention also relates to an installation equipped with such a collection device, and more particularly to a ventilation, heating and / or air conditioning, including a vehicle. It is more particularly intended to provide such a collection device whose operation is durable and efficient, which has a small footprint and which is made from a small number of parts whose assembly is easy and fast, in particular to allow the manufacture of the device at a competitive cost and possibly to facilitate its maintenance and maintenance operations.

The device of the present invention is a collection device by electrostatic precipitation of particles previously charged and conveyed in an air flow. This device comprises at least two electrodes arranged in the air flow, these electrodes being alternately connected to the ground and to a terminal of a polarized source.

According to the present invention, such a device is mainly recognizable in that said electrodes each consist of a wall comprising openings, at least one of whose faces walls are formed with wings, the wings of the connected electrode. at the terminal collecting the previously charged particles.

Thanks to these provisions, the structure of the electrodes is simplified and their installation inside the device is made easy. More particularly, the particle collecting wings are collected on the same element, which is easily made from a single manufacturing operation, and whose mountain inside the device is made easy by its character. monobloc interconnecting the different wings of the electrodes.

More particularly, the wall is disposed transversely to the air flow, the wings being oriented substantially parallel to the latter. The openings formed through the wall allow the passage of the air flow by limiting the aeraulic losses, while the wings are likely to extend as much as necessary parallel to the air flow to collect the particles.

The wings are preferably interconnected by junction elements embodying the wall. The openings extend between two successive joining elements. More specifically, the wall is formed from the connecting elements, which extend from one wing to the other to connect them transversely to each other. Several connecting elements are preferably used by being distributed longitudinally along the wings, the openings being formed between them. These provisions are such that the connecting elements are likely to have a reduced surface against the air flow, the complementary surface formed by the openings leaving a free passage to the air by reducing air losses as well as possible , without impairing the robustness of the junction of the wings between them.

The wall and the wings forming the electrode advantageously form a unitary piece. Such a unitary piece can be easily made by mechanical production methods or by molding a plastic material.

Preferably; the device comprises at least one pair of electrodes whose walls are arranged vis-à-vis. The wings are nested with an electrode the other. More specifically, the walls are arranged parallel opposite each other, the wings of a wall being arranged in the space between two wings of the other wall. One of these electrodes is more particularly connected to the ground, while the other is connected to the terminal of a polarized electrical source, in particular of a reverse polarity to that used for the prior electric charging of the particles. These provisions make it possible to implement large areas of particle collection, while reducing the overall size of the device.

According to an alternative embodiment, the device comprises at least three successive electrodes, a median electrode having wings at each of its faces which are interleaved with the end electrode wings. The median electrode is more particularly connected to the ground and / or the terminal of a polarized electric source, in particular of a reverse polarity to that used for the prior electric charge of the particles, while the two other electrodes are inversely connected to the terminal of a polarized electrical source, in particular of a reverse polarity to that used for the prior electric charging of the particles, and / or to ground. The median electrode is capable of being made from a pair of strips assembled to one another via their wall placed back to back, or from the same folded strip to form wings extending on both sides of the wall. The median electrode is also capable of being formed by molding a plastic material, being rendered conductive by coating a metal material or by load for example.

Preferably, the electrodes are held in the general plane of their wall inside a support, as shaped in frame. This frame is advantageously composed of two elementary frames assembled to one another, between which the electrodes are held.

The device preferably comprises at least one member for maintaining the wings of at least one electrode at a set distance separating the wings from each other. These provisions are intended to ensure reliability and durability maintaining a precise and constant separation distance of the wings from each other.

The holding member is advantageously shaped as a comb. The teeth of the comb are likely to be engaged on the connecting elements, and / or on the wings.

According to an alternative embodiment, the teeth of the comb are engaged alternately on two nested wing electrodes. More particularly, the teeth of the comb are engaged on the wings of each of the electrodes in the zone of the openings that comprises the wall of one of the electrodes.

Preferably, the device comprises at least one pair of combs, each of which is respectively engaged with the wings of one electrode and with the base of the wings of the other electrode.

Advantageously, the holding member also constitutes an assembly member of the electrodes to the frame, to promote the quality of the junction between the electrodes and the frame. Preferably, the holding member is formed on at least one of the elementary frames, with which it advantageously forms a unitary piece, obtained by molding an electrically insulating plastic material in particular.

The wall is advantageously provided with an electrical connection member. It follows from these provisions that the plurality of wings that comprises the electrode are jointly supplied via the wall, and more particularly via the connecting elements, from a single electrical connection member. The frame includes in particular at least one light through which emerges the connecting member fitted to each of the electrodes.

The collection device is capable of being associated with a pulsator generating the air flow and of being disposed downstream of a device for charging the particles.

According to a first variant, the collection device and the charging device form a single unit housed in a common housing, this housing preferably housing the blower. Such a housing can be used independently to clean the air occupying a space, such as the passenger compartment of a vehicle. Said housing is also likely to be that of a ventilation system, heating and / or air conditioning, including a vehicle. The collection device is preferably placed in the air inlet of the installation, downstream of the charging device.

According to a second variant, the collection device and the charging device are formed of separate assemblies housed in respective housings in aeraulic communication for the passage of the air flow from one to the other of the housings.

According to a first method of obtaining an electrode of a collection device of the invention, it is formed from a punched strip to arrange the openings, and then folded in its general plane to form the wings.

According to a second method of obtaining an electrode of a collection device of the invention, it is formed by molding a plastic material made conductive.

According to a third method of obtaining an electrode of a collection device of the invention, it is formed by extrusion of a plastic material made conductive.

Said plastic material is for example made conductive by adding a metal filler, or by applying a coating, especially metal.

According to a fourth method of obtaining an electrode of a collection device of the invention, it is formed by extrusion of a metallic material.

Description of the figures.

• La fig.1 est une vue schématique en coupe d'un boîtier logeant un dispositif de collecte selon l'invention.
• La fig.2 est une vue schématique en perspective d'une première variante de réalisation d'une électrode participante du dispositif de collecte illustré sur la fig.1.
• Les fig.3a et fig.3b sont des vues schématiques en coupe prise respectivement dans la zone des ajours et dans la zone des éléments de jonction que comportent les électrodes participantes du dispositif de collecte illustré sur la fig.1.
• Les fig.4a et fig.4b sont des vues schématiques en coupe prise respectivement dans la zone des ajours et dans la zone des éléments de jonction que comportent les électrodes participantes d'un dispositif de collecte selon une deuxième variante de l'invention.
• Les fig.5a et fig.5b sont des vues schématiques en coupe prise respectivement dans la zone des ajours et dans la zone des éléments de jonction que comportent des électrodes participantes d'un dispositif de collecte selon une troisième variante de l'invention.
• La fig.6 est une vue schématique à plat d'un feuillard à partir duquel est réalisée une électrode illustrée sur la fig.2.
• Les fig.7a à fig.7f sont des vues schématiques en coupe du feuillard illustré sur la fig.6 à différentes étapes d'un premier procédé de fabrication du dispositif de collecte.
• Les fig.8a à fig.8b sont des vues schématiques en perspective de différentes étapes de réalisation d'une électrode illustrée sur la fig.2 selon un deuxième procédé de fabrication.
• La fig.9 est une vue schématique en perspective d'un cadre élémentaire destiné à recevoir des électrodes illustrées sur la fig.2.
• La fig.10 est une vue schématique en perspective d'un cadre équipée d'un couple d'électrodes illustrées sur la fig.2.
• Les fig.11 et fig.12 sont des vues schématiques en coupe partielle d'un cadre illustré sur la fig.10, respectivement ménagées à travers d'ajours et d'éléments de jonction de deux électrodes imbriquées selon une première forme de réalisation du dispositif de collecte.
• Les fig.13 et fig.14 sont des vues schématiques en coupe partielle d'un cadre illustré sur la fig.10, respectivement ménagées à travers d'ajours et d'éléments de jonction de deux électrodes imbriquées selon une deuxième forme de réalisation du dispositif de collecte.

The present invention will be better understood and details will arise from reading the description which will be made in connection with the figures of the attached plates, in which:

• The fig.1 is a schematic sectional view of a housing housing a collection device according to the invention.
• The fig.2 is a schematic perspective view of a first variant embodiment of a participating electrode of the collection device illustrated on FIG. fig.1 .
• The fig.3a and fig.3b are diagrammatic sectional views taken respectively in the zone of the openings and in the zone of the joining elements that comprise the participating electrodes of the collecting device illustrated on FIG. fig.1 .
• The fig.4a and fig.4b are diagrammatic sectional views taken respectively in the area of openings and in the area of the joining elements that comprise the participating electrodes of a collection device according to a second variant of the invention.
• The fig.5a and fig.5b are diagrammatic sectional views taken respectively in the area of openings and in the area of the joining elements that comprise participating electrodes of a collection device according to a third variant of the invention.
• The fig.6 is a schematic plan view of a strip from which is made an electrode illustrated on the fig.2 .
• The fig.7a to fig.7f are schematic sectional views of the strip illustrated on the fig.6 at different stages of a first method of manufacturing the collection device.
• The fig.8a to fig.8b are schematic perspective views of different steps of making an electrode illustrated on the fig.2 according to a second manufacturing method.
• The fig.9 is a schematic perspective view of an elementary frame for receiving electrodes illustrated on the fig.2 .
• The fig.10 is a schematic perspective view of a frame equipped with a pair of electrodes illustrated on the fig.2 .
• The fig.11 and fig.12 are schematic partial sectional views of a frame shown on the fig.10 respectively formed through openings and joining elements of two nested electrodes according to a first embodiment of the collection device.
• The fig.13 and fig.14 are schematic partial sectional views of a frame shown on the fig.10 respectively formed through openings and joining elements of two nested electrodes according to a second embodiment of the collection device.

On the fig.1 , a housing (1) houses an electrostatic device for cleaning a flow of air flowing therethrough. Said apparatus is more particularly intended to retain by electrostatic precipitation particles carried by the air flow, such as dust particles, and prevent their rejection outside the housing (1). The housing (1) houses a blower (2) for circulating through the electrostatic apparatus the air admitted into the housing (1) from an air inlet (3) formed in the latter upstream of the blower (2). ), to an air outlet (4) in the housing (1) downstream of the blower (2). The housing (1) is likely to be that of a ventilation system, heating and / or air conditioning, including a motor vehicle. In this case, the blower (2) is indifferently that of the installation or an additional blower. In this case again, the electrostatic apparatus is preferably placed in the air inlet (3) of the installation, or in the ventilation system, heating and / or air conditioning, indifferently upstream or downstream of the blower (2 ). The housing (1) is also likely to be a stand-alone housing placed in the passenger compartment to clean the air contained therein.

The electrostatic apparatus comprises a device (5), such as a corona type charger, which is intended to charge particles carried by the air flow and a device (6) for collecting the previously charged particles, which is arranged in the airstream downstream of the charging device (5). This corona type charger more particularly comprises a pair of electrodes respectively connected to one of the terminals of a polarized power source. The particles present in the air flow circulate between the electrodes which deliver a high voltage discharge, indifferently positive or negative. This discharge produces ions that collide with the particles and charge them electrically.

In the embodiment variant of the collecting device (6) illustrated on the fig.1 , it comprises two electrodes (7,8) arranged in the housing (1) vis-à-vis one another. A first electrode (7) is connected to the ground (9), while a second electrode (8) is connected to one of the terminals (10) of a polarized power source (11), and more particularly to a terminal of inverse polarity to that applied to the particles by the charging device (5). The particles conveyed in the air stream, previously loaded by the charging device (5), are attracted and then retained by the second electrode (8) to prevent their rejection from the housing (1). According to different embodiments, the charger and the collector can belong to a single set, in particular being grouped together in the same box, or else be organized in two separate sets.

On the fig.2 , an electrode consists of a wall (12) on one side of which its formed wings (13) of small thickness. These wings (13) are oriented orthogonally to the wall (12) and parallel to each other. Two neighboring wings (13) are spaced from each other by a distance of the order of a few millimeters. The wall (12) is disposed in the housing (1) orthogonal to the flow direction of the air flow (14) so that the wings (13) extend parallel to this direction. To allow the flow of air to pass on both sides of the wall (12), the latter comprises openings (15) formed therethrough. These openings (15) occupy most of the surface of the wall (12) and extend transversely between two wings (13) adjacent. Elements of junction (16) of the wings (13) between them materialize the wall (12). The cumulative surface of the junction elements (16) is much smaller than the cumulative surface of the openings (15), to optimize the passage of the air flow through the wall (12) and limit the aeraulic losses. The cumulative surface of the joining elements (16) is just necessary to give the electrode a satisfactory mechanical strength. Such an electrode has a large particle collection surface for a small footprint, its installation in the collection device (6) is made from the implementation of a single piece, which associates the wall (12) composed of connecting elements (16), and wings (13) joined together by them.

On the fig.3a and fig.3b , the collecting device (6) comprises a pair of electrodes (7,8) such as those illustrated on the fig.2 . The respective wings (13) of the two electrodes (7, 8) are nested one inside the other so that a wing (13) of an electrode is interposed between two adjacent wings (13) of another electrode. The walls (12) of the two electrodes (7,8) are parallel to one another, the junction elements (16) and the respective openings (15) which they comprise being placed opposite each other. Such an arrangement of the junction elements (16) and openings (15) minimizes the aeraulic losses. The wings (13) vis-à-vis two electrodes (7,8) form a corridor (17) for air circulation which extends from an aperture (15) of an electrode to the ajour (15) vis-à-vis the other electrode. The charged particles carried in the air stream (14) are attracted and retained by the wings (13) of the electrode in relation to the terminal (10) of the power source.

On the fig.4a and fig.4b , the collection device comprises three electrodes (7,8,18), which are placed successively in the air flow. A median electrode (18) is composed of two electrodes of the type represented on the fig.3a and fig.3b which are leaned against each other via their wall (12). This backing is likely to be achieved by welding, gluing, pleating or other similar techniques for such a backing. Preferably, the openings (15) and the joining elements (16) of two backed electrodes are disposed respectively opposite each other. Such arrangements make it possible, from the same type of electrode, to optimize the particle collection surface and / or to increase the filtering power.

On the fig.5a and fig.5b the collecting device (6) has three electrodes (7,8,18). A median electrode (18) has wings (13) which are alternately formed on its upstream face and on its downstream face. The wings (13) respectively upstream and downstream of the median electrode (18) are interleaved with the wings (13) of two corresponding end electrodes (7, 8), of the type of those illustrated in FIGS. fig.3a and fig.3b .

On the fig.3a to 5b , the walls (12) of the electrodes (7, 8, 18) disposed both upstream and downstream of the air flow (14) comprise perforations (15) to allow the air to pass therethrough.

On the fig.6 , an electrode of the type represented on the fig.3a and fig.3b , is made from a metal strip (19) punched and folded on itself. More particularly, in a first manufacturing step, cuts, including rectangular, are formed through the strip (19) to form the openings (15). The cuts are formed by punching the strip (19) according to an indifferently square or rectangular grid, so that the cuts are symmetrically distributed in the strip (19) in a plurality of rows and columns. Some of these cuts are arranged in overlapping fold lines (20) intended to form the flanges (13) and at a distance from flap lines (21) intended to bring together two adjacent solid areas of the strip (19) situated between the cuts. . On the fig.6 the folding lines (20, 21) are illustrated in broken lines.

On the fig.7a to fig.7e the strip (19) is folded along the folding lines (20) and the flap lines (21) to form the wings (13) of the electrode, the solid portion of the strip (19) between two cutting columns being folded on itself along the flap line (21). On the fig.7f two identical electrodes (7,8) made according to the folding method described above, are nested one inside the other to form a collection device such as that shown in FIGS. fig.3a and fig.3b . Note that these two electrodes (7,8) are identical and are made by the same method to reduce the manufacturing costs of the collection device (6).

On the fig.8a the electrode is made by extrusion of a plastic material rendered conductive, by charging of metal particles or by the application of a conductive coating. According to another variant embodiment, the electrode may be made by extrusion of a metallic material. In a first step illustrated on the fig.8a the electrode is obtained by molding and has a solid wall (22) provided with wings (13) at one of its faces. On the 8B the wall (22) of the electrode is punched to provide the openings (15) and the connecting elements (16). According to another embodiment, the electrode may be made by molding a plastic material made conductive by charging metal particles or by applying a conductive coating. In this case, the shaped electrode as illustrated on the 8B is directly obtained by molding.

On the fig.9 a first basic frame (23) is provided with two combs (24) for receiving the wings (13) of two nested electrodes (7,8), to ensure accurate positioning of the electrodes (7,8) therebetween. one side and wings (13) of each electrode (7,8) on the other hand. Note that this arrangement of the first elementary frame (23) is capable of responding to cooperation with the wings (13) of the electrodes (7,8,18) obtained according to any embodiment referred to above. These arrangements are such that the wings (13) are maintained at a precise and constant separation distance from each other, to avoid electrical discharges between them. The first elementary frame (23) is formed of a unitary piece combining the combs (24), a peripheral wall (25) and stiffening ribs (26) connecting the peripheral walls (25) of the frame (23) to each other. ). The combs (24) extend between two opposite edges of the elementary frame (23) according to a orthogonal direction to the wings (13) of the electrodes it receives. The combs (24) advantageously constitute a mechanical reinforcing element of the frame (23) and are preferably arranged opposite the junction elements (16) of the electrodes (7, 8) to minimize the aeraulic losses.

On the fig.10 the first elementary frame (23) is connected to a second elementary frame (27) to jointly form a frame-shaped support (28) which houses the two interleaved electrodes (7, 8) in its interior. This assembly can be achieved by welding, gluing, interlocking, clipping or the like. The second elementary frame (27) is preferably structurally similar to the first elementary frame (23), or is likely to be limited to pieces of structure that attach to the first elementary frame (23), such as by welding, gluing, interlocking by clipping or similar technique. The frame (28) has a lumen (29) providing a passage for respective connecting members (30) of each of the electrodes (7,8), respectively to the corresponding terminal (10) of the power source (11). ) and to the mass (9). Each connecting member (30) is advantageously formed in the extension of one of the connecting elements (16). Such arrangements facilitate the electrical connection of the collection device (6).

The fig.11 and fig.12 are representations in section of the device of the invention. One of the elementary frames (27) is equipped with a comb (24). On the fig.11 the cut is made in an area of openings (15) occupied by the comb (24). In this zone, the air flow (14) can not pass through the frame because of the presence of the comb (24) which partially occupies the passage of air that the openings (15) leave. On the fig.12 , the section is made in an area of openings (15) which is not occupied by the comb (24), this area being used for the passage of the air flow (14).

On the fig.13 and fig.14 , the two elementary frames (23,27) are each equipped with a comb (24). The teeth of each comb (24) are alternately engaged on the nested wings (13) of the one and the other of the electrodes (7,8), and more precisely on the end of the wings (13) of an electrode (7) and at the base of the wings ( 13) of the other electrode (8). On the fig.13 the cut is made in an area of openings (15) occupied by the combs (24). In this zone, the air flow (14) can not cross the frame because of the presence of the combs (24) which partially occupy the passage of air that the openings (15) leave. On the fig.14 the cut is made in an area of openings (15) which is not occupied by the combs (24), this area being used for the passage of the air flow (14).

Claims (26)

1. Collector (6) for the electrostatic precipitation of precharged particles conveyed in an air stream (14), this collector (6) comprising at least two electrodes (7, 8, 18) placed in the air stream, these electrodes (7, 8, 18) being connected respectively to earth (9) and to a terminal (10) of a biased power supply (11), characterized in that said electrodes (7, 8, 18), each consist of a wall (12) having apertures (15), on at least one of the faces of which wall there are provided fins (13).
2. Collector according to Claim 1, characterized in that the wall (12) is placed transversely to the air stream (14), the fins (13) being oriented substantially parallel to the latter.
3. Collector according to either of the preceding claims, characterized in that the fins (13) are connected together by joining elements (16) forming the wall (12), the apertures (15) extending between two successive joining elements (16).
4. Collector according to any one of the preceding claims, characterized in that the wall (12) and the fins (13) making up the electrode (7, 8, 18) form a single piece.
5. Collector according to any one of the preceding claims, characterized in that it comprises at least one pair of electrodes (7, 8, 18), the walls (12) of which face each other, the fins (13) being imbricated from one electrode (7, 8, 18) to the other.
6. Collector according to any one of the preceding claims, characterized in that it comprises at least three successive electrodes (7, 8, 18), a central electrode (18) having fins (13) on each of its faces which are imbricated with the fins (13) of the end electrodes (7, 8).
7. Collector according to any one of the preceding claims, characterized in that the electrodes (7, 8, 18) are retained in the general plane of their wall (12) inside a frame (28).
8. Collector according to Claim 7, characterized in that the frame (28) is made up of two elementary frames (23, 27) joined together, between which the electrodes (7, 8, 18) are retained.
9. Collector according to any one of the preceding claims, characterized in that it includes at least one retaining member, for retaining the fins (13) of at least one electrode (7, 8, 18) at a set distance separating the fins (13) from one another.
10. Collector according to Claim 9, characterized in that the retaining member is in the form of a comb (24).
11. Collector according to Claim 10, characterized in that the teeth of the comb (24) are engaged on the fins (13).
12. Collector according to Claims 5 and 10,
    characterized in that the teeth of the comb (24) are engaged alternately on two electrodes (7, 8, 18) having imbricated fins (13).
13. Collector according to Claim 12, characterized in that the teeth of the comb (24) are engaged on the fins (13) of each of the electrodes (7, 8, 18) in the region of the apertures (15) of the wall (12) of one of the electrodes (7, 8, 18).
14. Collector according to Claim 13, characterized in that it comprises at least one pair of combs (24), which are each engaged on the end of the fins (13) of one electrode (7, 8, 18) and at the base of the fins (13) of another electrode (7, 8, 18) respectively.
15. Collector according to any one of Claims 9 to 14, characterized in that the retaining member and the elementary frame (23, 27) form a single piece.
16. Collector according to any one of the preceding claims, characterized in that the collector (6) is connected to a blower (2) for generating the air stream (14) and is placed upstream of a particle charger (5).
17. Collector according to Claim 16, characterized in that the collector (6) and the charger (5) form a single assembly housed in a common enclosure (1).
18. Collector according to Claim 17, characterized in that said enclosure (1) is that of a ventilation, heating and/or air-conditioning unit.
19. Collector according to Claim 18, characterized in that the collector (6) is placed at the air inlet (3) of the unit, downstream of the charger (5).
20. Collector according to Claim 16, characterized in that the collector (6) and the charger (5) are formed from separate assemblies that are housed in respective pneumatically communicating enclosures in order for the air stream (14) to pass from one of the enclosures into the other.
21. Method of obtaining an electrode of a collector according to Claim 4, characterized in that the electrode (7, 8, 18) is formed from a metal sheet (19), drilled so as to provide the apertures (15), and then folded in its general plane in order to form the fins (13).
22. Method of obtaining an electrode of a collector according to Claim 4, characterized in that the electrode (7, 8, 18) is formed by moulding a conductive plastic.
23. Method of obtaining an electrode of a collector according to Claim 4, characterized in that the electrode (7, 8, 18) is formed by extruding a conductive plastic.
24. Method according to either of Claims 22 and 23, characterized in that the plastic is made conductive by adding a metal filler.
25. Method according to either of Claims 22 and 23, characterized in that the plastic is made conductive by applying a coating.
26. Method of obtaining an electrode of a collector according to Claim 4, characterized in that the electrode (7, 8, 18) is formed by extruding a metallic material.

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