FR3019474A1 - FILTRATION DEVICE - Google Patents

Abstract

A device for purifying a particle-laden gaseous medium, comprising: an electrostatic filtration chamber (11) having a passage for the gaseous medium charged with particles; suction means (12) for extracting from the chamber the gaseous medium removed from its particles, characterized in that the chamber comprises a plurality of emissive structures (23) arranged in the passage, one after the another between the inlet and the outlet of the chamber, and on either side of these emissive structures, collector structures (22) designed to trap the particles contained in the gaseous medium, each emissive structure being in the form of a plate designed to force the gaseous medium to flow in the vicinity of the collector structures and having, at its periphery, points directed towards the collector structures.

Description

The present invention relates to a device for purifying a gaseous medium loaded with particles of all kinds, such as dust particles, organic particles in suspension in the exhaust gases of all kinds, and in particular diesel engines,. ..

It is more particularly intended to be used in an industrial facility, an establishment (hospital, restaurant, ...) or a residential building (house, apartment), especially in the form of a mobile device. The applicant has already proposed this type of device for treating a gaseous medium loaded with particles, but intended more particularly for the exhaust gas of an internal combustion engine (see in particular the patent application WO 01/19525). This treatment device comprises a corona electrofilter comprising a cylindrical longitudinal envelope in which extends a longitudinal passage for the gases to be treated, an emissive structure extending longitudinally in the center of the passage and a collector structure extending longitudinally. between the passage and the envelope and comprising a plurality of cavities forming trapping housings of the particles contained in the gaseous medium, the emissive structure comprising a plurality of serrated plates arranged transversely to the longitudinal direction and forming points directed towards the collecting structure . These serrated plates are all carried by a rod connected to a circuit providing a stabilized high voltage. The present invention aims to provide a device of this type, better suited to the uses mentioned above, while remaining effective, and leading further to other advantages. It proposes, for this purpose, a device for purifying a gaseous medium charged with particles, comprising: an electrostatic filtration chamber having a passage for the gaseous medium charged with particles, extending between an inlet of this medium in the room and an exit of the latter; suction means fluidly connected to this outlet for extracting from the chamber the gaseous medium freed of its particles, characterized in that the electrostatic filtration chamber comprises a plurality of emissive structures arranged in the passage, one after the the other between the inlet and the outlet of the chamber, and on either side of these emissive structures, collecting structures designed to trap particles contained in the gaseous medium loaded with particles, each emitting structure presenting itself in the form of a plate designed to force the gaseous medium charged with particles to flow in the vicinity of the collector structures and having, at its periphery, points directed towards the collecting structures. With these provisions, the present invention provides a purification device optimized in terms of efficiency as well as the aforementioned uses. It is indeed possible in particular to orient each of the emissive structures or electrodes as desired, in particular to obtain, for example, effects of ozone production or not, to play with the flow of the gaseous medium in the filtration chamber. or even to individually wear each of the electrodes at a different voltage. More generally, these arrangements also make it possible to produce a device that is easy to manufacture and also to maintain, which, in addition, can be produced, as needed, in the form of a compact structure. According to particular arrangements, which may, where appropriate, be combined with one another: at least one of the emissive structures is mounted in the electrostatic filtration chamber; each plate is in the form of a blade that can be twisted; - Each plate has, on either side of a central deflection surface, indentations forming between them said tips; - The tips are arranged staggered along two opposite edges of each plate; the edges of the plates provided with the tips extend to the vicinity of the collecting structures, leaving only a space avoiding the formation of arcs, in a position in which the plates extend perpendicularly to the collector structures, parallel between them ; each plate comprises a rod projecting on each of two opposite mounting edges, for mounting the plate on a support; the support is in the form of a frame provided, for the reception of each rod, with a passage opening thereof; each emitting structure is carried at high voltage, preferably at a voltage of the order of 10 kV; each collecting structure comprises, for the trapping of the particles, a metal knit and / or a succession of drawn metal plates; each collecting structure is raised to high voltage, preferably at a voltage of the order of 5 kV; the emissive structures are aligned, following an alignment parallel to the collector structures; each collecting structure has a rectangular parallelepiped shape; each collecting structure comprises a collector plate mounted on a frame and having at least one connecting element to a circuit providing a high voltage, electrically isolated from the frame. Other objects, features and advantages of the present invention appear from the description which follows, made with reference to the accompanying drawings, in which: - Figure 1 is a schematic perspective view of a device for purifying a gaseous medium charged with particles, according to the present invention; FIG. 2 is an exploded view, on a different scale, of the main elements of the device of FIG. 1; and FIG. 3 is a plan view, schematic and on a different scale, of an emissive structure of this device.

The device for purifying a particle-laden gaseous medium which is the subject of the embodiment of FIGS. 1 to 3 is an independent device, which can be mounted on rollers. It has a global configuration of rectangular parallelepiped.

For the sake of highlighting its characteristic elements, this purification device has been shown very schematically in these figures. The assembly of its various component parts has in particular not been shown in detail, as well known to those skilled in the art.

This purification device 10 generally comprises an electrostatic filtration chamber 11 and suction means 12 downstream of this electrostatic filtration chamber, for extracting from the chamber the gaseous medium freed of its particles. In practice, this electrostatic filtration chamber 11 is here interposed between an inlet compartment 13 through which the gaseous medium loaded with particles enters the device and more particularly into the electrostatic filtration chamber 11 and an outlet compartment 14, whereby the suction means 12 are housed and through which the gaseous medium freed of its particles is released into the surrounding environment.

According to the rectangle parallelepiped configuration of the purification device 10, the inlet compartment 13 comprises a frame 15 carried by a bottom 16 and formed of four walls assembled at right angles, one of which, 17, is perforated to allow the gaseous medium to enter the device, here from below the electrostatic filtration chamber 11.

In the case of the present embodiment, the particulate-laden gaseous medium thus enters the purification device 10, in a direction substantially perpendicular to that of flow in the filtration chamber 11. Before entering this electrostatic filtration chamber here, it passes through a prefilter 18 intended to retain the large particles. This is, for example, a metal knit filter or stretched metal.

At the opposite end of the purification device 10, the outlet compartment 14 of the gaseous medium freed of its particles comprises a box 19 in the form of a rectangular parallelepiped, whose upper wall 20 is perforated to pass this gaseous medium free of its particles. . The suction means 12, which are here in the form of a fan, are mounted in this box 19, at the face thereof opposite the perforated wall 20. The gaseous medium flows thus, horizontally in the inlet box 15 and then vertically to the outlet of the purification device 10. As can be seen in Figures 1 and 2, the suction means 12 are arranged directly at the outlet of the filtration chamber electrostatic 11 and are in fluid communication therewith for sucking the gaseous medium.

This electrostatic filtration chamber 11 comprises, here, two supports 21 of emissive structures arranged in the passage formed by the electrostatic filtration chamber 11 between an inlet therein (after the prefilter 18) and an outlet thereof (just before the suction means 12). On either side of these emissive structure supports 21 are arranged collecting structures 22 designed to trap the particles contained in the gaseous medium loaded with particles. Each support 21 of emissive structure comprises, more specifically, a plurality of emissive structures 23 arranged in the passage, one after the other, between the inlet and the outlet of the electrostatic filtration chamber 11. Each structure emissive 23 is in the form of a plate, preferably a plate, here five in number by support 21, designed to force the gaseous medium loaded with particles to flow in the vicinity of the collector structures 22.

Each blade 23 also has, at its periphery, points directed towards the collecting structures 22.

It is more particularly, as can be seen more clearly in FIG. 3, a blade 23 having, on either side of a central deflection surface 24, notches 25 forming between them said tips 26. This is, here, rounded indentations cut into a stainless steel plate so that the tips of the two opposite edges of the blade 23 provided with these points 26 are arranged in staggered rows. Each support 21 comprises two U-shaped sections 27 assembled, parallel to each other and back-to-back, by four spacers 28 welded, each, to a corner of the U-profile 27. It should be noted in this connection that the fourth spacer 28 is not visible in the figures. Each blade 23 comprises, for its mounting on this support 21, a rod 29 welded on each of two opposite mounting edges 30 which extend generally perpendicular to the edges of the blades 23 provided with the tips 26.

The U-shaped sections 27 are provided, for the reception of the rods 29, passage openings 31 of these rods. The holding in position on the support 21 of each of the blades is obtained, in the case of the present embodiment, by means of the interposition of an insulator 32 nested, by complementarity of shapes (of square section), 20 in a opening 31 and receiving, itself, a rod 29 of the blade 23. Each rod 29 is, for this purpose, threaded and engaged in a central cylindrical hole of the insulator 32 and fixed by a nut (not visible in the figures and housed in a through hole 36 of square section preceding this cylindrical hole in the insulator and ending before the latter hole by a bearing surface 25 for the nut), so that each blade is mounted with possibility In other embodiments, the insulator can also be protected by means of a bell, in the manner of what is described in FIG. the patent application cited above ( WO 01/19525). Each blade 23 forming an emitting structure is here brought to a cathode voltage of the order of 10 kV by a circuit providing a high voltage 33, housed in a control box 34 mounted, in the context of the present embodiment, in the casing 19. For the trapping of the particles, each collection structure 22 comprises, in the context of the present embodiment, a metal knit in the form of a plate carried, here, at an anode voltage of the order of 5 kV , being connected to a circuit providing a high voltage, which is also housed in the control box 34. For their high voltage supply, the collector plates 22 can be mounted in a frame via rods passing through openings arranged in this context and interposition of insulators, in a manner similar to that provided for the blades 23 on their support 21. As a result, it has not been shown in the figures, for the sake of simplification. However, it will be noted that the connection to the circuit 35 can be obtained for example with a leaf spring secured to the upper box 19 and in contact with a rod of the plate 22. The implementation of one or more of these blades can also allow to maintain the plate in position within the device and its establishment and withdrawal thereof. In the case of the central collector plates 22, the retention in place is ensured by their arrangement between the two supports 21 (their introduction and removal is obtained by simple sliding). Such arrangements are not shown, for the sake of simplicity, in Figures 1 to 3, but can be easily implemented by those skilled in the art from the above explanations. The purification device according to the present invention, as described in particular with reference to FIGS. 1 to 3, thus proves to be particularly flexible, in particular by mounting the blades 23 on the supports 21, one independently of the other ( and electrically isolated from each other on their support). This makes it possible, in particular, to orient each of the blades as desired, in particular to produce ozone having a germicidal effect on microorganisms of the virus and bacteria type. This ozone production can be obtained by orienting the blades 23 perpendicularly to the collector plates 22, while a different orientation of the perpendicular (the tips are moved away from the collector structures 22) will stop or decrease this production of ozone. Of course, the blades 23 are always oriented so as to form a non-zero angle with the plane of the collector plates 22 which extend parallel to each other, the blades 23 themselves being aligned in a parallel alignment to these same plans. Note also that the edges of the blades 23 provided with the tips 26, extend to the vicinity of the collector plates 22, leaving only a space avoiding the formation of arches in a position in which the blades 23 ' extend perpendicularly to these collector plates 22 is, in practice, a space of the order of one millimeter per 1000V of voltage applied to the corresponding blade 23 In addition, negative ions produced by the ionization taking place in the filtration chamber electrostatic are also interesting in terms of the therapeutic effects they can generate. It will also be noted that the possibility of orienting the blades 23 makes it possible to play with the speed of the gaseous flow flowing in the electrostatic filtration chamber 11. A door 37 is, moreover, provided for isolating the lateral collector plates 22 from the medium surrounding, while being able to access to remove them from the purification device 10 for cleaning. This device is also easy to manufacture, for example from a cut and, where appropriate, a folding of stainless steel plates. Moreover, such a device can also be easily implemented in already existing systems. Of course, the present invention is not limited to the embodiment chosen and shown, but encompasses any variant within the scope of the skilled person. In particular, the device according to the invention could comprise a UV radiation lamp arranged upstream of the inlet of the electrostatic filtration chamber 11 (for example in box 15) to attract and kill insects, such as mosquitoes.

At the opposite end, a finishing filter, for example based on activated charcoal, metal knit or stretched metal, can also be implemented between the electrostatic filtration chamber 11 and the suction means 12.

Each collector structure may further comprise one or a succession of metal plates drawn in place of the metal knit or be made from an alternation of metal knit and stretched metal plates. Other voltages can also be envisaged for the emitting and collecting structures. In particular, it may be envisaged to wear, in a succession of stretched metal plates forming a collector structure, one plate out of two at a voltage of the order of 5 kV and to put the next to ground. Generally, the voltages are chosen to be between 10 and 50 kV.

Depending on the voltage that is decided to apply to the emissive and collector structures, the circuit providing a high voltage will of course provide a positive or negative high voltage. It will be noted, moreover, that a frame, made from profiles, such as angles, can come to complete the device, for example for its mounting on wheels or the introduction of the central collector plates on rails in the form of U to facilitate their sliding. Only one support of emissive structures, or more than two, can be considered. In addition, each blade may, to increase turbulence in the suction flow, be twisted.

Claims (13)

REVENDICATIONS1. A device for purifying a particle-laden gaseous medium, comprising: - an electrostatic filtration chamber (11) having a passage for the particle-laden gaseous medium, extending between an inlet of this medium in the chamber and an outlet of the latter; suction means (12) fluidly connected to this outlet for extracting from the chamber the gaseous medium freed of its particles, characterized in that the electrostatic filtration chamber comprises a plurality of emissive structures (23) arranged in the passage, one after the other between the inlet and the outlet of the chamber, and on either side of these emissive structures, collector structures (22) designed to trap the particles contained in the gaseous medium charged with particles, each emissive structure being in the form of a plate designed to force the gaseous medium loaded with particles to flow in the vicinity of the collector structures and having, at its periphery, spikes (26) directed towards the structures collector. 2. Device according to claim 1, wherein at least one of the emissive structures is steerably mounted in the electrostatic filtration chamber. 3. Device according to claim 1 or 2, wherein each plate is in the form of a blade that can be twisted. 4. Device according to any one of claims 1 to 3, wherein each plate has, on either side of a central deflection surface, indentations forming between them said tips. The device of claim 4, wherein the tips are staggered along two opposite edges of each plate. 6. Device according to claim 4 or 5, wherein the edges of the plates provided with the tips extend to the vicinity of the collector structures, leaving only a space avoiding the formation of arcs, in a position in which the plates extend perpendicular to the collector structures, parallel to each other. 7. Device according to any one of claims 1 to 6, wherein each plate comprises a rod (29) projecting on each of two opposite mounting edges, for mounting the plate on a support. 8. Device according to claim 7, wherein the support is in the form of a frame provided, for the reception of each rod, a passage opening thereof. 9. Device according to any one of claims 1 to 8, wherein each emitting structure is raised to high voltage, preferably at a voltage of the order of 10 kV. 10. Device according to any one of claims 1 to 9, wherein each collecting structure comprises, for the trapping of the particles, a metal knit and / or a succession of drawn metal plates. 11. Device according to any one of claims 1 to 10, wherein each collector structure is raised to high voltage, preferably at a voltage of the order of 5 kV. 12. Device according to any one of claims 1 to 11, wherein the emissive structures are aligned in an alignment parallel to the collector structures. 13. Device according to any one of claims 1 to 12, wherein each collecting structure has a rectangular parallelepiped shape. 15