Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
  • H05H1/00—Generating plasma; Handling plasma
  • H05H1/24—Generating plasma
  • H05H1/47—Generating plasma using corona discharges
  • H05H1/471—Pointed electrodes

Definitions

• the present invention relates to the field of plasma discharge by corona discharge and more particularly that of plasma reactors.
• corona plasma device to produce, by corona discharge, a plasma and an ionic flux.
• a corona plasma device advantageously makes it possible to produce a plasma for ionizing a fluid passing through the device.
• Such ionization finds multiple and complementary functionalities, for example, in the field of the treatment of a fluid, such as air.
• an ionization allows, by ion deposition, to charge a particle contained in the fluid. This particle thus charged can advantageously be retained by an electrostatic filter, which can be arranged downstream of the device.
• an ionization has a neutralizing action on pathogenic organisms, such as viruses, which can be carried in the fluid.
• an ionization advantageously produces oxidizing chemical species useful for the decontamination of a mechanical filter, such as an activated carbon filter, which can be arranged downstream of the device.
• a corona plasma device or a plasma reactor comprising a plurality of such devices, advantageously constitutes an upstream stage of a multi-fluid filter means.
• corona plasma device It is known to produce a corona plasma device, to use a polarized electrode and an earth electrode, arranged opposite the polarized electrode, and to apply between these two electrodes a significant potential difference, of the order of several thousand volts. This creates a plasma as well as corona discharges producing ion discharges. The ionization effect of the fluid is obtained by creating a circulation of the fluid forcing the fluid to pass through the plasma.
• FIRE I LLE OF REM PLACEM ENT in a first configuration, said tip plane, a polarized electrode having a small radius of curvature is disposed perpendicularly to a substantially flat earth electrode; in another so-called wire-cylinder configuration, a wired polarized electrode is disposed axially in a cylindrical earth electrode.
• FR 2818451 proposes to combine these two configurations by using a needle-shaped polarized electrode and a ground electrode comprising a substantially plane wire mesh disposed perpendicular to the polarized electrode and a cylinder surrounding the polarized electrode over its entire length. This device is traversed by the fluid in a direction parallel to the coinciding axis of the polarized electrode and the cylinder.
• the subject of the invention is a corona plasma cell comprising a substantially needle-shaped polarized electrode and an earth electrode disposed opposite the polarized electrode, comprising a cylinder substantially centered on the polarized electrode and a substantially plane porous film perpendicular to the polarized electrode, wherein the cylinder has a low profile, preferably with negligible height in front of its diameter, and wherein the polarized electrode does not penetrate the cylinder.
• the porous film is arranged, relative to the polarized electrode, on the side opposite the cylinder.
• the porous film is a surface for the passage of air with pores having a size ranging from 0.1 mm to 500 mm, preferably from 5 mm to 50 mm.
• the thickness of the porous film is advantageously between 0.5 and 50 mm, preferably between 1 and 5 mm.
• the porous film is a metal mesh
• the meshes may have different shapes (square, rhombus, etc.).
• the metal mesh in question is a sheet of expanded metal.
• the subject of the invention is also a corona-effect dual plasma element comprising a first corona-effect plasma cell as defined above comprising a first polarized electrode and a first earth electrode, arranged facing the first polarized electrode, a second cell a corona-effect plasma as defined above comprising a second polarized electrode and a second earth electrode disposed opposite the second polarized electrode, wherein the first cell and the second cell are arranged symmetrically (head to tail).
• the first polarized electrode and the second polarized electrode are connected to the same first potential and the first ground electrode and the second ground electrode are connected to the same second potential, different from the first potential.
• the first potential is negative and the second potential is ground.
• the polarized electrode or electrodes are connected to a negative potential and are then called discharge electrodes.
• the first polarized electrode and the second polarized electrode are substantially needle-shaped and are supported by a conductive support connected to the first polarized electrode, the second polarized electrode and the first potential, which conductive support is preferably substantially plane.
• the conductive support comprises a printed circuit comprising at least one conductive track connected to the first polarized electrode, the second polarized electrode and the first potential.
• a polarized electrode is disposed in a metallized via pierced in said at least one conductive track.
• the printed circuit comprises days, preferably entirely, to the exclusion of a narrow band formed around said at least one conducting track.
• the first polarized electrode and the second polarized electrode are axially aligned, and are preferably made of material (ie one and the same piece).
• At least one of the first cell and the second cell is a cell according to one of the preceding embodiments.
• the invention further relates to a plasma reactor comprising a plurality of corona plasma emission devices arranged side by side in a substantially plane arrangement, where the devices are cells according to one of the preceding embodiments, or the devices are dual elements according to one of the preceding embodiments.
• the arrangement is a substantially square grid.
• FIG. 1 illustrates, in sectional view, a cell according to the invention
• FIG. 2 illustrates, in cutaway view, a dual element according to the invention
• FIG. 3 illustrates, in cutaway view, the polarization of a dual element
• FIG. 4 illustrates, in cutaway view, a dual element comprising two cells of FIG. 1,
• FIG. 5 illustrates, in sectional view, the dual element of FIG. 4, side according to one embodiment
• FIG. 6 illustrates, in cutaway view, a plasma reactor
• FIG. 7 illustrates, in perspective view, a plasma reactor
• FIG. 8 illustrates, in plan view, a printed circuit supporting polarized electrodes.
• the invention relates to an improved corona 1 1 plasma cell.
• a cell 1 1 comprises a polarized electrode 12 substantially needle-shaped and a ground electrode 13, disposed opposite the polarized electrode 12.
• the ground electrode 13 comprises a cylinder 14 substantially centered on the polarized electrode 12 and a porous film 15 substantially plane perpendicular to the polarized electrode 12.
• the polarized electrode 12 is typically fixed on a support 16 advantageously perforated to allow the passage of a flow of fluid. The distance between the polarized electrode 12 and the earth electrode
• a cell 1 1 according to the invention is improved in that the cylinder 14 is shaped so as to have a low profile. This means that the height of the cylinder
• the diameter of the cylinder is between 20 and 100 mm, preferably between 25 and 75 mm, for example between 30 and 60 mm and, particularly preferably between 35 and 55 mm.
• the thickness of the cylinder it is less than 10 mm, preferably between 1 and 5 mm.
• the polarized electrode 12 is shaped sufficiently short so as not to penetrate the cylinder 14.
• the flow of fluid to be ionized by means of the cell 1 1 is substantially vertical with respect to FIG. 1.
• the combined reduction in the height of the cylinder 14 and the length of the polarized electrode 12 advantageously makes it possible to drastically reduce the overall height. of the cell 1 1, since the ground electrode 13, much lower can be close to the polarized electrode 12, itself shortened.
• the polarized electrode 12 out of the cylinder 14 makes it possible to shape the plasma substantially in a very flattened cone shape, substantially transverse to the fluid flow, favoring good ionization.
• the opening angle of the ion flow cone is between 136 ° and 1 12 °.
• the porous film 15 is arranged, relative to the discharge electrode 12, on the side opposite to the cylinder 14. This is advantageous for the shape of the plasma / ion flux. In addition, this simplifies manufacture, since a continuous porous film can be deposited behind the cylinder 14, even though the porous film 15 is visible from the polarized electrode 12 only in the inner circular opening delimited by the cylinder 14.
• the invention also relates to an advantageous configuration, in which two cells 1, 1, 21 are assembled symmetrically (in a back-to-back or inverted configuration). Also, the invention relates to a dual corona plasma element comprising a first corona plasma cell 11 and a second corona plasma cell 21.
• the first cell 1 1 comprises a first polarized electrode 12 and a first ground electrode 13 arranged facing the first polarized electrode 12.
• the second cell 21 comprises a second polarized electrode 22 and a second ground electrode 23 arranged in view of the second polarized electrode 22.
• the first polarized electrode 12 and the second polarized electrode 22 are connected to one and the same first potential 8 and the first earth electrode 13 and the second earth electrode 23 are connected to one same second potential 9, different from the first potential 8.
• the signs of the first and second potentials 8,9 can be arbitrary. However, it is known that the ionization obtained by corona effect is more effective when the polarized electrode is connected to a negative potential (it is called discharge electrode). Also, preferably the first potential 8 is negative and the second potential 9 is the mass.
• the first cell 1 having an opposite orientation to that of the second cell 21, their ionizing effects combine and complement each other, thereby increasing the overall ionizing effect.
• the opposite orientation still advantageously makes it possible to apply the same polarization to the two cells 1 1, 21.
• these two characteristics of orientation and polarization combined advantageously make it possible to fix the first polarized electrode 12 on a first support 16 and the second polarized electrode 22 on a second support 26.
• these two supports 16,26 can be a single support 36, the polarized electrodes 12,22 being each supported respectively by one side of the support 36.
• This structure is therefore particularly economical and advantageous.
• the common support 36 may be conductive and be connected to the first polarized electrode 12, to the second polarized electrode 22 and to the first potential 8.
• the common support 36 comprises a printed circuit 36 comprising at least one conductive track 31 connected to the first polarized electrode 12, the second polarized electrode 22 and the first potential 8.
• the polarization of a corona plasma device requires a difference in high potential, between polarized electrode and earth electrode, which potential difference is of the order of several thousand volts.
• the first potential 8 is very high and could prove vulnerable for an operator.
• the configuration according to the invention advantageously provides a confinement of this first potential 8 in the middle of the dual element 10. The first high potential 8 is thus out of reach of an operator.
• Such a dual element 10, and therefore a reactor 30 built on the basis of such a dual element 10, have a naturally safe conformation with respect to this electrical hazard.
• the support 16, 26 being a printed circuit 36
• the first potential 8 being distributed within the support by means of a conductive track 31, advantageously arranged in said printed circuit 36
• a polarized electrode 12, 22, substantially needle-shaped is advantageously assembled on the support 16,26 by means of a via 33 drilled in the printed circuit 36.
• the via 33 is metallized and pierced in a conductive track 31. The drilling is such that it provides the electrical connection.
• the printed circuit 36 being disposed across the flow of fluid is advantageously perforated to allow the passage of this fluid flow.
• at least one day 38 is made for this purpose. In order to maximize the passage of fluid therethrough, said at least one day 38 may cover the entire surface of the circuit board 36 excluding at least one narrow band formed around said at least one conductive track 31.
• FIG. 8 An embodiment of a printed circuit 36 for a plasma reactor according to this characteristic is illustrated in FIG. 8.
• the relative position of the first polarized electrode 12 and the second polarized electrode 22 was arbitrary.
• the first polarized electrode 12 and the second polarized electrode 22 are axially aligned. This allows advantageously to make them material, a single needle with two tips simultaneously forming two polarized electrodes 12,22. This further advantageously makes it possible to fix the two polarized electrodes 12, 22 simultaneously in the same through via 33, in a single operation.
• the two cells 1 1, 21 may be of any type.
• the first cell 1 1, the second cell 21, or both are a cell according to the invention, as illustrated in Figure 1, a cell with a cylinder 14 having a low profile.
• Figures 4-6 illustrate a configuration with two such identical cells.
• a plasma reactor 30 On the basis of a cell 1 1 or a dual element 10 according to one of the previous embodiments, it is possible to build a plasma reactor 30.
• the known principle of a plasma reactor is to juxtapose, according to a arranging side by side, in a plane perpendicular to the fluid flow, a plurality of corona plasma devices. This makes it possible to increase at will the section and therefore the flow rate of fluid that can pass through the plasma reactor 30.
• a plasma reactor 30 juxtaposes devices which are cells 1 1, according to one of the preceding embodiments, or dual elements 10 according to one of the preceding embodiments.
• a central printed circuit 36 serves to support on both sides to the two sets of polarized electrodes 32. It further ensures by means of conductive tracks 31 the connection of these polarized electrodes 32 to the first potential 8 (preferably negative).
• a series, respectively two series, of struts 37 moves away and supports a plate, respectively two plates, 34 pierced (s) of cylinders and a plate, respectively two plates, 35 of porous film.
• the plates 34, 35 are advantageously metallic in order to be conductive and connected to the second potential 9.
• the arrangement of the devices 1.10 in a plasma reactor 30 can be arbitrary.
• FIG. 1 illustrates a possible embodiment of a printed circuit 36 adapted to such a square grid arrangement.
• This printed circuit board 36 comprises an array, for example rectangular of conductive tracks 31. These tracks are advantageously embedded in the insulating thickness of the printed circuit 36. They are electrically connected to the first potential 8. According to a substantially square grid arrangement, are drilled vias 33, in which are installed the polarized electrodes 12,22,32.
• the circuit board 36 is cut from days 38 occupying a maximum area to maximize the fluid passage section. This maximum area is just restricted by the saving of a narrow band around the tracks 31. Holes 39 are formed, advantageously without electrical connection, spatially distributed, to allow fixing of the spacers 17, 27, 37, advantageously carried out made of insulating material.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Plasma Technology (AREA)

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• 2017
  • 2017-04-20 FR FR1700439A patent/FR3065615B1/fr active Active
• 2018
  • 2018-04-20 ES ES18723700T patent/ES2949966T3/es active Active
  • 2018-04-20 RU RU2019134263A patent/RU2763742C2/ru active
  • 2018-04-20 EP EP18723700.3A patent/EP3613264B1/fr active Active
  • 2018-04-20 WO PCT/EP2018/000214 patent/WO2018192682A1/fr unknown
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