air purifier

Abstract

The air purification device comprises an ionizer (12) configured to ionize a portion of the particles present in the air, an agglomeration chamber (21) configured to agglomerate at least a portion of the particles ionized by the ionizer into a particle agglomerate, at least one first collector (31) configured to collect at least a portion of the particle agglomerate, and a frame (4). The at least one first collector has a first surface (311 S ) and the first reference surface (312 R ) An electric field of at least 10 kV / m is generated between the first surface and the first reference surface. The ionizer (12) comprises a plurality of spikes (121) and a grid (122). An electric field of at least about 100 kV / m is generated between the plurality of spikes (121) and the grid (122).

Description

[Technical field]

[0001] The present invention relates to an air cleaning device, more precisely a device capable of destroying particles present in the air. This type of device is intended to decontaminate the air of areas to be decontaminated, in particular areas located outdoors. [Background technology]

[0002] Fuel combustion causes the emission of particularly fine and ultrafine particles, which remain suspended in the air due to their small average weight and are a major public health problem. In measuring particulate matter (PM), a distinction is made according to the size of the particles, specifically between "PM10", "PM2.5" or "PM1" fine particles with diameters less than 10 μm, 2.5 μm or 1 μm respectively. Particles with a diameter less than 0.1 μm are classified as "ultrafine particles".

[0003] Air quality monitoring employs highly sophisticated physical methods to detect fine and ultrafine polluting particles, including the use of optical counting processes using, for example, quartz crystal microbalances, beta probes, or laser diffraction sensors.

[0004] Some commercially available devices purify the air in enclosed environments, such as living rooms, by ionizing airborne particulates that then agglomerate, with the heavier agglomerates either falling to the floor or adhering to the walls of the room through electrostatic effects, where they can accumulate and be collected.

[0005] Currently, outdoor air decontamination consists primarily of limiting particle emissions at the source, for example by devices such as catalytic converters in vehicles, filters for area and industrial heating systems, and waste incinerators.

[0006] A recent approach to at least locally decontaminating outdoor air from fine and ultrafine particles consists in the suction and filtration of airborne fine and ultrafine particles. Envinity®, a Dutch company, has published a design for an ultra-powerful aspirator that includes a filter, usually in the form of a filter cartridge consisting of one or more layers of porous, fibrous or granular material for filtering the air. The Envinity aspirator can suction up to 800,000 m per hour. 3 The company claims that it can filter 95% of PM and 90% of ultrafine particles from the treated air [Reference 1]. However, this approach consumes a lot of energy to circulate a large volume of air through a small area. Furthermore, changing and cleaning the filters requires high material and labor costs.

[0007] It is also known to use photocatalysts, for example titanium dioxide (TiO2), to remove outdoor air pollution. TiO2, when activated by ultraviolet light emitted by natural or artificial sources, allows the oxidation (by photocatalysis) of pollutants, so that they are converted into the oxidation products CO2 and H2O. Photocatalysis is brought about by a coating containing a photocatalyst, for example applied to external walls in public places or near roads. This method allows the destruction of odors and the cleaning of surfaces. However, this method is limited, since it only works on particles that naturally deposit on the treated surface.

[0008] Recently, the applicant has developed a device for localized decontamination of air, using the surface of the envelope of a capture balloon to capture fine particles and convert them into CO2 and H2O [Reference 2]. This decontamination device is based on the potential difference between the balloon envelope and the environment, which allows the fine particles to be attracted onto the envelope, where they can be decomposed, for example, by a coating containing titanium dioxide. However, in practice, the applicant has demonstrated that the effect of wind on the fine particles often turns out to be dominant over the electric attraction, so that the fine particles tend to slide on the balloon when wind is present.

[0009] Published US Patent Application Publication No. 2013 / 025449 [Reference 3] further describes a particle capture device that may form part of (or be incorporated into) an object, including an urban street lighting installation. The capture device includes a chargeable surface and a generator configured to generate a charge on the chargeable surface, thereby generating an electrostatic field of at least 0.2 kV / m.

[0010] US Patent Application Publication No. 2020 / 376498 [Reference 4] describes a bidirectional electrostatic filter system intended to treat heavy pollution in factories and using an adjustable distance between the front (or rear) charging part and the part for collecting polluting particles.

[0011] The present application describes an air cleaning device that is adapted to function with low energy consumption, for example outdoors, but with increased effectiveness compared to known prior art devices. Summary of the Invention [Means for solving the problem]

[0012] As used herein, "comprising" has the same meaning as "including" and "containing" and is inclusive or open and does not exclude other elements not described or expressed. Furthermore, as used herein, the terms "about" and "substantially" are synonymous with (meaning the same thing as) at least one of less than 10% and more than 10%, e.g., 5%, of the respective value.

[0013] According to a first aspect, the present invention relates to an air cleaning device, in particular an air cleaner adapted to extend over an area to be decontaminated.

[0014] The air purifying device according to the first embodiment has a width of about 1 m 2At least one first collector comprising a first surface of a non-insulating material of a larger area, a first reference surface of a non-insulating material, and a first generator configured to apply a first electric potential to the first surface of between about 5 kV and about 500 kV relative to the first reference surface to generate an electric field of about 10 kV / m or more between the first surface and the first reference surface. In the remainder of the description, the first reference surface and the first generator will more simply be referred to as the reference surface and the generator.

[0015] The air cleaning device according to the first aspect further comprises an ionizer configured to ionize a portion of particulate matter present in the air, for example by corona emission, the ionizer comprising a plurality of spikes, a grid and a generator configured to apply a predetermined potential to the spikes of the plurality of spikes relative to the grid to generate an electric field between the plurality of spikes and the grid of at least about 100 kV / m.

[0016] The space between the ionizer and the first collector is referred to herein as an aggregation chamber. The aggregation chamber is configured to aggregate at least a portion of the particles ionized by the ionizer to form a particle aggregate. Thus, the at least one first collector is configured to collect at least a portion of the particle aggregate. The at least one first collector can also collect at least one of at least a portion of the non-aggregated ionized particles and at least a portion of the particles, e.g., ionized particles.

[0017] The air cleaning device according to the first aspect further comprises a frame configured to enclose at least the ionizer, the coagulation chamber and the at least one first collector.

[0018] By non-insulating material is meant a conductive material or a material with finite impedance, i.e. a material that can fully or partially transmit an electric potential. In the remainder of the description, non-insulating materials are also referred to as finite electrical impedance materials. In one or more embodiments, this type of non-insulating material has a finite electrical impedance of at least 10 -4The material has a conductivity of at least 1 S / cm, such as at least 10 S / cm.

[0019] The non-insulating material may include a single material or a combination of different materials. For example, the non-insulating material that comprises the first surface may include an additive, such as aluminum, that makes the material conductive or gives it a non-zero finite impedance. The first material may also include multi-layer materials.

[0020] The Applicant has therefore demonstrated that it is possible to capture with greater efficiency the particles present in the air of the area to be decontaminated, compared to known devices.

[0021] The device according to the first embodiment has for this purpose a construction comprising three successive stages: a first stage for ionizing the particles, a second stage for agglomerating the ionized particles, and a third stage for collecting the particle agglomerates and at least a portion of the non-agglomerated particles, all of these elements being assembled in a frame.

[0022] In the third stage, i.e. the collector, a strong electric field of the order of 10 kV / m or more is generated between the first surface and a reference surface. The particulate agglomerates coming from the second stage, i.e. the agglomeration chamber, as well as the non-agglomerated particles, are subjected to the electric field. Depending on the direction of the electric field and the sign of the charge on said agglomerates and particles, said agglomerates and particles are attracted by the first surface or by the reference surface and are deposited on the first surface or the reference surface, respectively.

[0023] A frame surrounding the three stages contributes to generating and directing the airflow through the three stages of the air cleaning device.

[0024] The frame can be insulating, but according to one or more embodiments, the frame includes a non-insulating material that is electrically connected to ground, for example for safety reasons.

[0025] The applicant has demonstrated that the device according to the first aspect of the present specification is able to purify the air without the need for a filter cartridge, which represents a clear advantage. Indeed, compared to the prior art, e.g. the super-powerful aspirator cited in [Reference 1], which has a high energy consumption to compensate for the air resistance inherent in the presence of a filter cartridge, the device according to the first aspect consumes less energy.

[0026] Compared to devices such as those described in [Reference 3], the ingenious architecture including three independent stages formed by an ionizer assembled in a frame, a coagulation chamber and at least one first collector allows the effectiveness of the air purification device to be increased, especially for the generation and guidance of air passing through the various stages. It is therefore possible to purify a larger amount of air in a smaller volume.

[0027] In particular, in the device according to the first aspect, an electric field is generated between the spikes of the ionizer and the grid, independent of the electric field generated between the first surface of the at least one first collector and the reference surface. The grid of the ionizer thus constitutes a counter electrode, making it possible to avoid interdependence between the ionization and collection stages. In contrast to the device described for example in [Reference 4], an ionization stage independent of the collection stage is advantageous, since it makes it possible to avoid that parameters specific to one stage influence the parameters of another stage with regard to the optimization of the decontamination.

[0028] In one or more embodiments, the generator is a DC generator or an AC generator.

[0029] The first potential applied to the first surface relative to the reference surface is between about 5 kV and about 500 kV to generate an electric field between the two surfaces of about 10 kV / m or more. According to one or more embodiments, the first potential is between about 10 kV and about 500 kV, such as between about 30 kV and about 100 kV. In one or more embodiments, the maximum distance separating the spike or spikes of the first surface closest to the reference surface is n / 10 meters or less when the first potential=n kV, where n is a number between about 5 and about 500, for example. For example, when the first potential is equal to 5 kV, the maximum distance is equal to 0.5 m to generate an electric field between the two surfaces of about 10 kV / m or more.

[0030] The area of ​​the first surface is approximately 1 m 2 In one or more embodiments, the area of ​​the first surface is greater than about 5 m 2 Larger, e.g. about 10m 2 Larger, for example about 20m 2 Larger, e.g. about 100m 2 The surface is larger. Such a large surface may allow for the treatment of a large volume of air and a large amount of particulates when the device is deployed to decontaminate an area. In order that the weight and wind resistance of the device are not a disadvantage, and considering the implementation cost of the device, lightweight materials may be suitable for constructing the first surface, such as permeable materials such as thin perforated sheets, nets, canvases and combinations thereof. In one or more embodiments, the first surface comprises at least one flexible material, for example selected in the group including rubber, coated canvas, laminated canvas. In one or more embodiments, the at least one flexible material comprises a layer of fabric, for example polyester, covered by, for example, a PVC or polyurethane film. In one or more embodiments, the first surface comprises at least one rigid material, for example metal, for example aluminum, or a metal alloy, for example stainless steel. In one or more embodiments, the at least one rigid material is in the form of a perforated rigid plate.

[0031] In one or more embodiments, the first surface comprises at least one of a canvas and a net. A canvas in the sense of this specification is a two-dimensional arrangement of strands in a mesh-like (i.e. arranged according to a substantially regular pattern) mesh with an average dimension of less than about 1 cm. A net in the sense of this specification is a two-dimensional arrangement of strands. In one or more embodiments, the net is in a mesh-like shape with an average dimension of, for example, about 1 cm or more. For example, the net may consist of at least one of a collection of knotted ropes and an arrangement of welded metal wires.

[0032] The reference surface is included in at least one first collector of the air cleaning device according to the first aspect. In one or more embodiments, the reference surface has one or more of the characteristics described above for the first surface, for example in terms of composition, size, shape. The reference surface is a non-insulating material surface. It may be configured to extend over the area to be cleaned of the contamination. The reference surface is advantageously about 1 m. 2 It may have a larger size.

[0033] In one or more embodiments, the reference surface is electrically connected to ground and is therefore at ground potential. The reference surface may be electrically connected to ground by a conductive element. Alternatively, the reference surface may be applied with a potential different from ground potential and the first potential such that the electric field between the two surfaces is about 10 kV / m or more. In one or more embodiments, the potentials on the first surface and the reference surface are of opposite signs. Such a configuration of the air cleaning device advantageously allows for a high potential difference between the first surface and the reference surface without the potential of the two surfaces being too high. For example, the first surface may be +50 kV and the reference surface may be -50 kV such that the potential difference is 100 kV.

[0034] In one or more embodiments, the reference surface is a localized surface. By "localized surface" is meant herein a surface formed by the ends of at least one strand or at least one cable or at least one spike and combinations thereof. For example, the reference surface may consist of the end of a single strand or a single cable or a single spike. According to another embodiment, the reference surface may consist of the ends of multiple strands. In contrast to a net or canvas, the multiple strands of this type of localized surface are not assembled in the sense that some strands of the multiple strands do not form a two-dimensional array.

[0035] In one or more embodiments, the first surface and / or the first reference surface have a predetermined average surface roughness Ra, for example greater than 5 μm, for example greater than 10 μm, for example greater than 50 μm. In this way, the agglomerates and / or particles deposited on the first surface and / or the reference surface are better retained by the first surface and / or the reference surface, thereby limiting the risk of them being drawn back into the air and escaping outside the device. One method for measuring said average surface roughness Ra of a surface is, for example, contact profilometry.

[0036] In one or more embodiments, the first surface of at least one first collector comprises a plurality of plates arranged parallel to one another and electrically connected to one another. In these embodiments, the plurality of plates has a total plate area of ​​about 1 m. 2 Furthermore, these embodiments can be combined with the previous embodiments in which at least one of the first surface and the reference surface has a predetermined average surface roughness Ra.

[0037] In one or more embodiments, the reference surface of at least one first collector comprises a plurality of plates arranged parallel to one another and electrically connected to one another.

[0038] In one or more embodiments, at least some of the plurality of plates of the first surface and at least some of the plurality of plates of the first reference surface are arranged alternately in a first arrangement direction of the plurality of plates, and thus the plates of the first surface and the plates of the reference surface may be arranged at least partially or entirely in parallel alternating fashion within at least one first collector.

[0039] Advantageously, this parallel plate configuration minimizes air deceleration, allowing larger volumes of air to be processed with less energy consumption, as opposed to prior art aspirators which consume more energy to compensate for the air resistance inherent in the presence of the filter cartridge.

[0040] The plates of the "first surface-reference surface" plate pair make it possible to maximize the value of the electric field generated between the first surface and the reference surface. Nevertheless, a sufficient distance may be required to keep the electric field below the destructive electric field, i.e. the electric field where arcing may be observed, and to prevent foreign objects from entering the device and causing short circuits. Thus, in one or more embodiments, the distance between the plates of the first surface and the adjacent plates of the reference surface is between about 1 cm and about 50 cm, advantageously between about 1 cm and about 10 cm.

[0041] In one or more embodiments, the number of plates in the first surface and / or the number of plates in the reference surface is between about 2 and about 100, such as between about 10 and about 50, for example between about 10 and about 25.

[0042] In one or more embodiments, the first surface is coated with a coating that includes a photocatalyst capable of converting at least a portion of the particulate aggregates and / or particulates deposited on the first surface into oxidation products CO2 and HO. The photocatalyst can thus decompose the particulate aggregates and / or particulates deposited on the coating of the first surface and convert them into oxidation products CO2 and HO, for example, by a mechanism described in [Reference 5]. In one or more embodiments, a coating is present on at least a portion of the first surface. In one or more embodiments, the photocatalyst is a semiconductor with a wide band gap.

[0043] In one or more embodiments, the photocatalyst is selected from the group including photocatalysts including TiO2, ZnO, CeO2, ZrO2, SnO2, CdS, ZnS and combinations thereof. In one or more embodiments, the coating comprises titanium oxide TiO2. Among various photocatalysts, those that include or consist of TiO2 have high oxidizing power, good robustness (especially good stability over time), and low cost.

[0044] In one or more embodiments, the coating is the result of applying a solution containing a photocatalyst onto the first surface, as described, for example, in [Reference 2], followed by the formation of the coating during a drying step. Such a solution advantageously makes it possible to stabilize the coating when applied to the first surface. The solution may contain small amounts of one or more stabilizers, thereby preventing the coating from crumbling after drying.

[0045] In one or more embodiments, the reference surface is also coated with a coating that includes a photocatalyst capable of converting at least a portion of at least one of the agglomerates of particulates and particulates deposited on the reference surface into the oxidation products CO2 and HO.

[0046] In one or more embodiments, such a coating is present on at least a portion of the reference surface. The coating of the reference surface and the photocatalyst contained therein may be identical in all respects to the coating and photocatalyst, respectively, described above with respect to the first surface, or may have at least one common characteristic.

[0047] The ionizer of the air cleaning device according to the first aspect of the present specification is configured to ionize at least a portion of the particles present in the air, for example by corona discharge, but this is not a limitation of the present invention. The device may have its own generator. Alternatively, the generator of at least one first collector configured to apply the first potential to the first surface may function as a generator for the ionizer as well.

[0048] In one or more embodiments, the ionizer comprises a generator of ions, for example a generator of negative ions or a generator of positive ions.

[0049] As described above, the ionization device comprises a plurality of spikes, a grid, and a generator, the generator being configured to apply a predetermined potential to the spikes of the plurality of spikes relative to the grid to generate an electric field of at least 100 kV / m between the plurality of spikes and the grid.

[0050] As used herein, a "spike" means a protrusion having a base and a tip. The direction of the taper of a spike is the direction from the base of the spike to the tip of the spike.

[0051] The electric field generated between the spikes and the grid is intensified at the ends of the spikes by the "spike effect" described, for example, in [Reference 6], and this intensification is locally greater the sharper the spikes are, i.e. the smaller the radius of curvature of the ends of the spikes. Spikes machined for this purpose are available in the industry with radii of curvature of the order of a few micrometers. In this case, another effect, which is directly attributable to the spike effect, called "corona discharge" and described in detail, for example, in [Reference 2] and [Reference 7], is likely to occur at the end of at least one of the spikes. When an electric field is generated between the spikes of the spikes and the grid, at least one of the spikes will emit a cascade of ions by corona discharge, thus contributing to the ionization of the air entering the air cleaning device in the vicinity of that one spike. The ions thus produced are then likely to interact with ionized or neutral particles suspended in the incoming air. Neutral particles that end up interacting with the ions will then acquire a further charge and can be agglomerated in an agglomeration chamber into agglomerates of particles. Depending on the direction of the electric field and the sign of the charge of the agglomerates, the agglomerates of particulates are then attracted by the first surface of the at least one first collector or by the reference surface and are deposited on the first surface or the reference surface, respectively. Thus, the ability of the air cleaning device to capture particulates advantageously extends to neutral particulates.

[0052] When the ionizer is based on corona discharge, the condition for observing corona discharge is that the spikes are electrically conductive. The spikes are made of a non-insulating material, such as nickel-plated steel. In one or more embodiments, the spikes of the plurality of spikes have a length between 0.1 cm and 10 cm, such as between 0.5 cm and 1.5 cm. In one or more embodiments, the spikes of the plurality of spikes have a radius of curvature of about 100 μm or less.

[0053] In one or more embodiments, the total number of spikes included in the ionizer is between 2 and 100, such as between 3 and 50.

[0054] In one or more embodiments, at least some of the spikes of the ionizer are configured to be arranged parallel to one another, e.g., parallel to the direction of the incoming airflow. In one or more embodiments, the spikes are arranged such that the direction of their taper, i.e., from the base of the spike to the tip of the spike, is substantially the same as the direction of the incoming airflow.

[0055] In one or more embodiments, the spikes are arranged on an insulating, e.g. wooden, support. In one or more embodiments, the insulating support is substantially linear, e.g. a rod. For example, the average distance between two spikes arranged on a substantially linear insulating support is between about 1 cm and about 50 cm, e.g. equal to about 10 cm. For example, the average density of the spikes arranged on the linear support is between about 1 spike per 10 cm and about 1 spike per 50 cm. The insulating support is substantially flat, e.g. a flat grid. For example, the average density of the spikes arranged on the insulating support is between about 1 spike per 10 cm and about 1 spike per 50 cm. 2 Approximately 1 spike per ~200cm 2 In one or more embodiments, the spikes of the plurality of spikes are charged to a potential of at least about 1 kV relative to the grid, e.g., between about 10 kV and about 50 kV. In one or more embodiments, the spikes of the plurality of spikes are electrically connected to one another.

[0056] The grid is made of a non-insulating material. By grid, we mean a two-dimensional array of strands, for example an array of welded metal strands. In one or more embodiments, the grid is mesh-like (i.e. characterized by a substantially regular pattern), with an average mesh dimension of, for example, about 4 mm or less. In one or more embodiments, the strands making up the grid have a diameter between about 0.5 mm and about 1.5 mm. In one or more embodiments, the grid is electrically connected to ground. In one or more embodiments, the grid is positioned upstream of at least one spike of the ionizer with respect to the incoming air flow. Alternatively, in one or more embodiments, the grid is positioned downstream of some of the spikes of the ionizer with respect to the incoming air flow.

[0057] In one or more embodiments, the grille is disposed in a plane substantially perpendicular to the incoming airflow. Advantageously, the spikes are disposed substantially perpendicular to the plane of the grille.

[0058] The agglomeration chamber is configured to agglomerate at least a portion of the particles ionized by the ionizer into agglomerates of particles. The second stage of the device, i.e. the agglomeration chamber, thus serves as a buffer space between the ionizer and at least one first collector. In one or more embodiments, the length of the agglomeration chamber in the direction of the incoming air flow is between 10 cm and 2 m, for example between 20 cm and 1 m, and the applicant has demonstrated that such a length is favorable for the agglomeration of the particles. The phenomenon of agglomeration of the particles occurring here is all the more beneficial, since small particles are generally more harmful to health than particles of larger size. Furthermore, agglomerates of particles are easier to capture than non-agglomerated particles, due to their size plus their high charge number. Without wishing to be limited to any particular theory, the inventors acknowledge that due to the effect of a higher electric field (for example of the order of at least 100 kV / m) at the spike end, the particles can actually agglomerate with each other to form agglomerates of particles, for example polymer chains with a width of 2 to 10 microns and a length of up to 1 cm in some cases, as shown in [Reference 8]. The resulting nanostructured polymers are grouped into pellets that can further trap small PM in the agglomeration chamber. This is only one possible mechanism by which the ionized particulates are agglomerated into particulate agglomerates in the agglomeration chamber, and the inventors do not exclude other mechanisms being used according to the first embodiment, depending on the nature of the particulates, e.g., suspended in the air.

[0059] In one or more embodiments, the coagulation chamber comprises a tubular enclosure. This may lead to a more significant reduction in contamination by allowing the generation of electrostatic phenomena that effectively enhances the effectiveness of the air cleaning device. By "tubular enclosure" is meant a duct formed of a tube having an end. In one or more embodiments, the radial cross section of the tubular enclosure varies along its axial direction. In one or more embodiments, the radial cross section of the tubular enclosure is substantially the same along its axial direction, i.e., the tubular enclosure is a cylinder. In one or more embodiments, the tubular enclosure is made of a non-insulating material. In one or more embodiments, the enclosure is electrically connected to ground.

[0060] The at least one first collector of the purifier device according to the first aspect is configured to collect at least a portion of particulate agglomerates and / or particulates, in particular particulates ionized by the ionizer.

[0061] In one or more embodiments, the air cleaning device includes a plurality of collectors. For example, the device may include a first collector and at least one second collector. The at least one second collector may be configured to be located downstream of the first collector with respect to the incoming air flow, for example, such that the incoming air circulates through the plurality of collectors. In one or more embodiments, the at least one second collector may have similar characteristics as those described above with respect to the first collector. Thus, the second collector may include a second surface that may have the same characteristics as those described above with respect to the first surface of the first collector, a second reference surface made of a non-insulating material that may have the same characteristics as those described above with respect to the first reference surface of the first collector, and a second generator. Thus, the second generator of the second collector may apply a second potential to the second surface between about 5 kV and about 500 kV with respect to the second reference surface to generate an electric field of about 10 kV / m or more between the second surface and the second reference surface. In one or more embodiments, the generator of the second collector is the generator of the first collector.

[0062] In one or more embodiments, the frame comprises: an inlet chamber arranged upstream of the ionizer and configured to direct the incoming air flow towards the interior of the air cleaning device; an outlet chamber arranged downstream of said at least one collector with respect to the incoming air flow and configured to direct the outgoing air flow outside the air cleaning device; Equipped with.

[0063] In one or more embodiments, the frame is in the shape of a pipe with a variable cross section, for example, the frame is in the shape of a pipe that processes a large volume of air at the inlet of the device and converges towards the outlet chamber to potentially direct the exiting air flow.

[0064] In one or more embodiments, at least one voltage controller is configured to vary an electric field generated by a generator between the first surface and the first reference surface, thus changing the lines of force of the electric field. By varying the electric field, it is possible, for example, to change the trajectory of the agglomerates of particles and / or non-agglomerated particles following the lines of force. For example, the direction of the electric field can be reversed, thereby, for example, resulting in attraction of the agglomerates of particles and / or charged particles of the opposite sign (compared to the sign of charge of the agglomerates of particles and / or particles before reversing the direction of the electric field) by the first surface or the first reference surface, in which case the agglomerates of particles and / or particles of the opposite sign will be deposited on the first surface or the reference surface. In one or more embodiments, the voltage controller is configured to vary the electric field (for example, by changing the direction of the electric field) according to a cycle with a predetermined frequency, for example, from about 0.1 seconds to about 10 seconds. The voltage controller may further represent a solution for cleaning at least one first collector. For example, by changing the direction of the electric field, the particulate agglomerates and / or particulates may be suddenly pushed away by the first surface on which they are collected, freed from the influence of gravity and therefore capable of being sucked in, for example, during maintenance and / or cleaning operations of the apparatus.

[0065] In one or more embodiments, the apparatus further comprises an airflow control system configured to direct incoming airflow toward at least the first surface of the at least one first collector. The airflow control system may also or alternatively direct ambient air toward the reference surface of the at least one first collector. In one or more embodiments, the airflow control system comprises a rollable or foldable tarpaulin tarp. Such a tarp is deployed around the periphery of the apparatus to control the flow of ambient air, e.g., to direct the direction of wind.

[0066] In one or more embodiments, the airflow control system is configured to facilitate the passage of airflow between the first surface and the reference surface. The airflow control system comprises, for example, at least one fan or aerator that sucks and / or pushes air between the first surface and the reference surface. The airflow control system thus makes it possible to ensure sufficient airflow between the surfaces, especially even in the case of light or no wind. No wind or very slow winds, for example less than one meter per second, are generally associated with the conditions in which the most severe pollution phenomena occur. The airflow control system can also make it possible to slow down the airflow, for example in the case of strong winds, so that the pollution of the air passing between the first surface and the reference surface has time to be sufficiently removed by the device.

[0067] In one or more embodiments, the at least one fan is arranged at the level of an outlet chamber arranged downstream of the at least one first collector with respect to the inlet air flow. Such an arrangement allows air to be drawn in undisturbed at the inlet, thus limiting turbulence. Such an arrangement also allows a stable outgoing air flow to be extracted outside the air purification device, and this purified outgoing air can be directed towards a target area. This proves to be advantageous in that a global decontamination effect is not obtained when the device is used outdoors.

[0068] In one or more embodiments, the airflow control system comprises at least one deflector configured to direct the inflow airflow in the air cleaning device and the outflow airflow from the air cleaning device. For example, in one or more embodiments, the airflow control system comprises at least one deflector arranged at the level of the inlet chamber of the frame and at least one deflector arranged at the level of the outlet chamber of the frame. In one or more embodiments, the at least one deflector is selected in the group comprising fins, blades, flaps. The at least one deflector may be orientable as a function of the required direction of the inflow or outflow. For example, the airflow control system may comprise a plurality of vertical blades at the inlet and a plurality of horizontal blades at the outlet, or vice versa. The plurality of inlet / outlet blades may be supported, for example, on a plane, for example upstream / downstream of the inlet / outlet chamber, respectively, with respect to the inflow / outflow airflow. In one or more embodiments, the at least one deflector is arranged at least partially outside the inlet / outlet chamber.

[0069] In one or more embodiments, the generator of at least one first collector comprises at least one transformer configured to apply said first potential to the first surface relative to a reference surface, allowing an output voltage to be generated from an input voltage. In one or more embodiments, the transformer is configured to generate an output voltage between 1 kV and 1000 kV, for example between 5 kV and 500 kV, between 5 kV and 100 kV, from an input voltage between 12 V and 300 V, for example 12 V, 24 V, or 230 V. In one or more embodiments, the generator configured to apply said first potential to the first surface relative to a reference surface comprises electricity production means. In one or more embodiments, the electricity production means produces electricity autonomously. The electricity production means may for example power at least one of the airflow control system and the ionization device. In one or more embodiments, the electricity production means makes the air cleaning device self-sufficient in energy, which has the advantage that no connection to an existing electrical network is required, limiting operational costs. The electricity producing means may, for example, include an element selected from at least one photovoltaic panel, at least one wind turbine, and combinations thereof. The at least one solar panel may be positioned to limit the loss of the coating comprising a photocatalyst from exposure to sunlight when the coating comprising a photocatalyst covers at least one of the first surface and the reference surface. Furthermore, the at least one solar panel may be partially or substantially transparent to at least one of visible light and UV, for example partially or substantially transparent to at least one of blue light and UV.

[0070] According to a second aspect, the present specification relates to a method for purifying air using an air purification device according to the first aspect, said method according to the second aspect comprising the steps of placing the air purification device according to the first aspect in and / or under and / or above and / or around an area to be decontaminated; - ionizing at least a portion of the particles present in the air using the ionizer; - agglomerating at least a portion of the particles ionized by the ionizer into agglomerates of particles using the agglomeration chamber; - generating an electric field of about 10 kV / m or more between the first surface and the reference surface using the generator of the at least one first collector; - collecting at least a portion of said agglomerates of fine particles using said at least one first collector.

[0071] In one or more embodiments, the first surface and the reference surface of at least one first collector each comprise a plurality of plates arranged parallel to each other and electrically connected to each other, at least some of the plates of the first surface and some of the plates of the reference surface are arranged alternately in a first arrangement direction, and the air cleaning device is installed so that the plates obtain a substantially vertical arrangement. The substantially vertical arrangement of the plates allows for easier alignment of the plates, for example by limiting buckling, which allows for operation at higher voltages without fear of electrical arcing. Furthermore, when at least one of the first surface and the reference surface is coated with a coating containing the aforementioned photocatalyst, the vertical arrangement of the plates also allows for maximizing the absorption of sunlight and thus the photocatalytic effect.

[0072] In one or more embodiments, the air cleaning device is configured to be mobile, such that all or part of the device can be stored, for example, in a shed and deployed for a decontamination mission, or the device may be permanently deployed at a given location, for example, in the area to be decontaminated.

[0073] According to a third aspect, the present description relates to an air cleaning assembly comprising a plurality of air cleaning devices according to the first aspect, the air cleaning devices being connected to each other, e.g. mechanically connected to each other.

[0074] In one or more embodiments, the decontamination method according to the second aspect includes connecting a plurality of air cleaning devices according to the first aspect, e.g. mechanically interconnecting a plurality of said devices, where each of said devices according to the first aspect is configured to be mechanically connected to one or more other devices. This type of connection facilitates the production of large-sized air cleaning assemblies, such as pollution prevention barriers to be deployed around or along large-sized decontamination areas, such as factories, or high traffic areas, such as highways or ring roads. To this end, it may be advantageous for the air cleaning devices of the plurality of devices according to the first aspect to be substantially identical or all identical.

[0075] In one or more embodiments, the device is configured to take the form, fully or partially, of an urban street fixture, which may be, for example, of a shade and / or shelter type.

[0076] In one or more embodiments, the air purification apparatus according to the first aspect is configured to take the form of a shade having a length of between 1 and 20 m, such as between 1 and 10 m, and a width of between 1 and 10 m, such as between 1 and 5 m, with a central support pylon of a height of between 1 and 10 m.

[0077] In one or more embodiments, the air cleaning device according to the first aspect or the air cleaner assembly according to the third aspect is configured to take partly the form of a bus shelter or kiosk type urban street installation. The bus shelter may provide one or more of the following advantages: the presence of a mechanical support, the possibility of connection to an electric network, protection against wind. The volume below the bus shelter is protected from the wind and may benefit from the effective decontamination provided by the device. The air cleaning device may be installed, for example, on the roof of the bus shelter and in one or more embodiments comprises an airflow control system as described herein above, allowing the intake of air from outside and the ventilation of purified air to the user.

[0078] In one or more embodiments, the air cleaning device according to the first aspect comprises at least one fastening means, e.g. a plurality of fastening lugs, configured for mechanically connecting the air cleaning device to a vehicle. For example, the at least one fastening means may be configured to mechanically connect the air cleaning device to a roof of a vehicle, e.g. the roof of a bus. Alternatively, the air cleaning device may be installed under the frame of a vehicle, e.g. an electric vehicle.

[0079] In one or more embodiments, the air purification device has a volume that can be contained within a rectangular parallelepiped having a length of between about 190 cm and about 250 cm, a width of between about 80 and about 120 cm, and a height of between about 10 and 200 cm. [Brief description of the drawings]

[0080] Other advantages and characteristics of the invention will become apparent from the following description, illustrated by the figures. [Figure 1A] 1 is a schematic top view of an example air cleaning device according to the present disclosure. [Figure 1B] FIG. 1B is a schematic perspective view of an example apparatus similar to that shown in FIG. 1A. [Figure 2A] FIG. 1 is a schematic front view of a bus with four examples of devices according to the present disclosure mechanically connected to the roof. [Figure 2B] FIG. 2B is a schematic side view of the bus shown in FIG. 2A. [Figure 2C] FIG. 2C is a schematic diagram of the bus shown in FIGS. 2A and 2B from above. [Figure 2D] FIG. 2D is a schematic side view from the left side of the bus shown in FIGS. 2A to 2C. [Figure 3A] FIG. 13 is a schematic perspective view of an assembly of another example of an apparatus according to the present disclosure forming a contamination prevention barrier. [Figure 3B] FIG. 3B is a schematic perspective view of a device configured to be connected to one or more other devices to form the contamination prevention barrier shown in FIG. 3A. [Figure 3C] FIG. 3C is a schematic longitudinal view of the view shown in FIG. 3B. [Figure 4]FIG. 1 is a schematic cross-sectional view of a bus shelter in which another example of an apparatus according to the present disclosure is deployed on the roof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0081] In the drawings, elements are not drawn to scale for better legibility.

[0082] A top view of a first example of an air cleaning device 100a is shown in Figure IA. Figure IB is a perspective view of another example of the device 100b.

[0083] As shown in Figures 1A-1B, the apparatus 100a, 100b for cleaning an incoming air stream 200 includes at least one first collector 31. In other embodiments of the apparatus (not shown), the apparatus may include multiple collectors arranged one behind the other. The collector 31 may be approximately 1 m 2 A first surface 311 of non-insulating material of larger size S and non-insulated reference surface 312 R The collector 31 has the first surface 311. S and the reference surface 312 R to generate an electric field of about 10 kV / m or more between the reference surface 312 and R A first potential between about 5 kV and about 500 kV is applied to the first surface 311. S The device further comprises a generator configured to apply a

[0084] The air cleaning devices 100a, 100b further comprise an ionizer 12 configured to ionize a portion of the particles present in the incoming air 200, and an agglomeration chamber 21 configured to agglomerate at least a portion of the particles ionized by the ionizer 12 into agglomerates of particles. As for the collector 31, it is configured to collect at least a portion of the agglomerates of particles. Non-agglomerated particles may also be collected.

[0085] 1A-1B, the apparatus includes a frame 4 configured to enclose at least the ionizer 12, the aggregation chamber 21, and at least one first collector 31. The frame 4 may be made of insulating or non-insulating material. The frame may be made of a non-insulating material, for example, and electrically connected to ground for safety.

[0086] The air cleaning devices 100a, 100b may be configured, for example, to extend over the area to be decontaminated.

[0087] The ionizer 12 comprises a number of spikes 121, for example between 2 and 100 spikes, for emitting ions, and a grid 122. The generator of at least one first collector may also serve as a generator for the ionizer and may be configured to apply a predetermined potential to the spikes of the number of spikes 121 relative to the grid to generate an electric field of at least about 100 kV / m between the number of spikes 121 and the grid 122. This electric field value is sufficient to ionize at least a portion of the particulate matter present in the incoming polluted air 200. In some embodiments of the air cleaning device, the ionizer comprises its own generator.

[0088] The spikes 121 are, for example, made of a non-insulating material, for example nickel-plated steel. For example, the spikes are between about 0.1 cm and about 10 cm in length, and have, for example, an end radius of curvature of about 100 μm or less. Furthermore, as shown in Figures 1A-1B, the spikes 121 of the ionizer 12 may be configured to be arranged parallel to each other, for example, parallel to the direction of the incoming airflow 200.

[0089] Additionally, spikes 121 may be positioned such that the direction of their taper, i.e., from the base of the spike to the tip of the spike, is the same as the direction of the incoming airflow 200 (i.e., from the exterior to the interior of device 100a as represented by black arrow 200 in FIG. 1A). In some embodiments, at least some or all of the spikes are positioned such that the direction of their taper is opposite to the direction of the incoming airflow.

[0090] 1A, the spikes 121 may be electrically interconnected. The spikes 121 may be arranged, for example, on an insulating support, for example a wooden rod.

[0091] The grid 122 is made, for example, of a non-insulating material. For example, the grid 122 is made of a mesh-like arrangement of welded metal strands. The average size of the mesh is, for example, about 4 mm or less. The diameter of the strands constituting the grid 122 is, for example, about 1 mm. The grid is, for example, electrically connected to ground. As shown in Figures 1A and 1B, the grid can further be arranged downstream of the spikes 121 of the ionizer 12 with respect to the incoming air flow 200. Furthermore, the grid 122 can be arranged in a plane perpendicular to the incoming air flow 200. The spikes 121 are, for example, arranged perpendicular to the plane of the grid 122, as shown in Figures 1A and 1B.

[0092] The ionizer is for example based on corona discharge.

[0093] The aggregation chamber 21 , configured to aggregate at least a portion of the particles ionized by the ionizer 12 into aggregates of particles, serves as a buffer space between the ionizer 12 and the collector 31 .

[0094] As shown in Figures 1A and 1B, the coalescence chamber 21 may include a tubular enclosure 211. Such an arrangement may allow for greater reduction in contamination by making it possible to generate electrostatic phenomena and increase the effectiveness of the purifier device. The tubular enclosure 211 may be made, for example, of a non-insulating material. The enclosure 211 may be made, for example, of untreated aluminum or another non-insulating material. The tubular enclosure 211 may be electrically connected, for example, to ground.

[0095] As shown in FIGS. 1A and 1B, a first surface 311 of the collector 31 S The collector 31 may consist of a number of plates 311 arranged parallel to one another and, for example, electrically interconnected. R1A and 1B, the first surface 311 may be a plurality of plates 312 arranged parallel to one another and, for example, electrically interconnected. S Only four plates 311 are shown for the reference surface 312. R Only three plates 312 are shown.

[0096] Of course, it is clear that the number of plates 311 and / or 312 may vary depending on the embodiment and is not limited to that of the air purification devices 100a, 100b shown in Figures 1A and 1B. For example, the number of plates may be larger, for example, between about 10 and about 25.

[0097] 1A and 1B, the reference surface plates 312 may be interleaved between the first surface plates 311. The first surface plates 311 and the reference surface plates 312 may be interleaved in a first arrangement direction of the plates.

[0098] Advantageously, the parallel plate configuration minimizes air deceleration, allowing for large volumes of air to be processed with less energy consumption. Additionally, the closeness of the plates in the "first surface-reference surface" plate pair (311, 312) allows the value of the electric field generated between the first surface and the reference surface to be maximized, but remain below the disruptive electric field, i.e., the electric field at which arcing can be observed.

[0099] 1A-1B, the distance between the plates (311, 312) of the "first surface-reference surface" may be substantially constant in the first orientation of the plates. This distance may be, for example, at least about 1 cm, which may, for example, prevent foreign objects from entering the device and causing a short circuit.

[0100] In some embodiments, only some of the plates 311 of the first surface and some of the plates 312 of the reference surface are arranged alternately (e.g. "311, 312, 311, 312"). Similarly, in some embodiments, the distance between the plates (311, 312) of the "first surface-reference surface" is not constant in said first arrangement direction of the plates, for example as shown in Figure 3C (see below for further details).

[0101] 1st surface 311 S and reference surface 312 R At least one of the surfaces may have a predetermined surface roughness Ra, for example Ra is greater than 5 μm, such as greater than 30 μm, for example greater than 50 μm.

[0102] The frame 4 may, for example, include an inlet chamber 41 arranged upstream of the ionizer 12 and configured to direct the incoming air flow 200 into the interior of the air cleaning device 100a, 100b. The frame may, for example, include an outlet chamber 42 arranged downstream of the at least one first collector with respect to the incoming air flow and configured to direct the outgoing air flow 201 out of the air cleaning device 100a, 100b.

[0103] The apparatus 100a, 100b may, for example, direct the incoming air flow 200 to at least a first surface 311 of the collector 31. S The airflow control system may further comprise an airflow control system configured to direct air toward the first surface 311. The airflow control system may comprise, for example, at least one fan 421. The airflow control system may further comprise an airflow control system configured to direct air toward the first surface 311. S and the reference surface 312 R At least one fan 421 is configured to facilitate passage of airflow between the first surface 311 and the S and the reference surface 312 R The present invention at least one of sucking and pushing air between the first surface and the reference surface, for example between the plates 311, 312 of the first surface and the reference surface, thereby making it possible to ensure a sufficient flow of air between the surfaces even when the wind is slow or there is no wind at all.

[0104] The at least one fan 421 is arranged, for example, at the level of the outlet chamber 42, which is arranged downstream of the at least one collector 31 with respect to the incoming air flow 200. This type of arrangement allows the air 200 to be sucked in undisturbed at the inlet, thus limiting turbulence. This type of arrangement also makes it possible to extract a steady outgoing air flow 201 from the air cleaning device and to direct the outgoing cleaned air 201 towards a target area, for example. This may prove to be advantageous in that no global decontamination effect is obtained when using the device outdoors.

[0105] The generator of the collector 31 is represented by "V" in Fig. 1A. The generator of the collector 31 configured to apply said first potential to the first surface may also serve as a generator for the ionizer 12, for example to generate said electric field between the plurality of spikes 121 and the grid 122. The generator may comprise a transformer for generating an output voltage, for example between 1 kV and 1000 kV, for example between 5 kV and 500 kV, for example between 5 kV and 100 kV, from an input voltage, for example between 12 V and 300 V, for example between 12 V, 24 V or 230 V. The generator may comprise, for example, means for the production of electricity (not shown), capable of supplying electricity to at least one of the ionizer 12 and the at least one fan 421.

[0106] Furthermore, the first surface 311 S and reference surface 312 R At least one of the particles may be partially or completely coated with a coating (not shown) that includes, for example, a photocatalyst capable of converting at least a portion of at least one of the agglomerates of particulates and particulates deposited on said surface into oxidation products CO2 and HO. The photocatalyst may include, for example, titanium dioxide TiO2.

[0107] Therefore, the first surface 311 S and reference surface 312 R At least one of the particulate agglomerates and particulates captured by the collector 31 due to the influence of the electric field generated between them can be continuously converted into harmless oxidation products.

[0108] Other examples of air cleaning devices 100c, 100d according to the first embodiment of the present specification, e.g. similar to those described with reference to Figs. 1A-1B, are shown in Figs. 2A-2D. Each of the devices 100c, 100d comprises a frame configured to enclose at least an ionization device, a coagulation chamber and at least one first collector. A vehicle or bus 700 is shown in Figs. 2A-2D, on whose roof three devices 100c and one device 100d are connected, e.g. by fastening means 105 connected to the frame of each air cleaning device. As Figs. 2B and 2D show, the device 100d mounted at the front of the bus may have a frame with a tapered shape towards the front, which provides an improved ability to pass air through. The four devices 100c, 100d are connected to each other, e.g. mechanically, e.g. via welds, glue spots, bolts, screws, nuts. Of course, a different number of the same or different air cleaners may be disposed on the vehicle.

[0109] Each device 100c, 100d may for example comprise means for fastening it to the roof of a bus, namely for example a number of fastening lugs 105. The fastening lugs are for example distributed near the corners and / or sides of the device 100c, 100d. The fastening means are for example configured to connect the device 100c, 100d directly to the roof of the bus 700. A connection to a roof rack and / or a stiffening rib mounted on the roof of the bus, for example by means of one or more clamps, may likewise be envisaged in some embodiments.

[0110] The air cleaning device 100c may be accommodated in a volume with a shape adapted to the shape of the vehicle roof, for example a substantially rectangular parallelepiped shape, even though other shapes are conceivable, for example the shape of a tapered device 100d. The rectangular parallelepiped may have dimensions, for example, a length between 190 cm and 250 cm, a width between 80 cm and 120 cm, and a height between 10 cm and 200 cm. Said length may for example be oriented along the width of the bus. Such dimensions allow adaptation to the bus sizes permitted in France / Europe.

[0111] The generator of at least one first collector (not shown) of each device 100c, 100d may, for example, be equipped with its own and / or electricity producing means connected to the vehicle's battery.

[0112] Such an assembly of air cleaning devices installed on the roof of a vehicle, for example a truck, coach, car or bus, as shown for example in Figures 2A-2D, has several advantages, especially in urban centers where PM thresholds are frequently exceeded. For example, a bus 700 equipped with an assembly of air cleaning devices can circulate on polluted routes in urban centers, capturing polluted air as close as possible to the emission of the pollution. The closer to its source / emission source the more concentrated and fresh the pollution is, making it possible to capture it before it is dispersed and / or before reactions that give rise to secondary products occur. Moreover, as shown especially in Figures 2A and 2D, for example in the case of a bus 700 driven to the right, an air cleaning device mounted on its roof can capture the polluted air 200 from the road and emit the purified air 201 towards the sidewalk where pedestrians can enjoy its direct benefit.

[0113] Such direction of the incoming and outgoing air flows of each device may be facilitated by the presence of at least one deflector configured to direct at least one of the air flows within the air cleaning device and the air flows exiting the air cleaning device.

[0114] Each air cleaning device may include an airflow control system, for example including at least one deflector 422a at the inlet of the device and at least one deflector 422b at the outlet of the device.

[0115] The input deflector 422a may be a blade that is perpendicular to the roof of the bus, as shown in Figure 2A. Figure 2C further illustrates that the inlet deflector 422a of each device may be oriented, for example, at an angle of about 45° to the left side of the bus. Furthermore, Figures 2C and 2A each illustrate that the outlet deflector 422b may be a horizontal blade, and may be oriented, for example, at an angle of about 30° to the roof of the bus, to target the sidewalk and / or pedestrians present on the right side of the bus.

[0116] The plurality of inlet / outlet blades 422a, 422b may be supported, for example, on a flat grid (not shown), for example upstream / downstream of the inlet / outlet chambers, respectively, with respect to the incoming / outlet airflows 200 / 201. In the non-limiting example shown in Figures 2A-2D, the frame of the device 100c, 100d comprises an inlet chamber and an outlet chamber, in which such a flat grid is provided.

[0117] 2A and 2C are front and top views, respectively, of a bus 700, showing the action of the inlet deflector 422a and the outlet deflector 422b on the incoming polluted air flow 200 and the outgoing cleaned air flow 201. The bus is, for example, driving forward on the right side of the road, which creates an encouraged inflow of the polluted air 200 by the inlet deflector 422a and a targeted exhaust of the outgoing cleaned air 201 by the outlet deflector 422b.

[0118] The airflow control system of the devices 100c, 100d may for example comprise at least one fan (not shown) arranged for example at the outlet of the device, for example in an outlet chamber of the frame, so that the device can effectively purify the air even when the bus is stationary and / or stuck in traffic.

[0119] An air inlet which may be present on the bus 700 may for example be connected to the outlets of the devices 100c, 100d, for example to refresh the air in the bus.

[0120] Furthermore, the bus may, for example, include a system for cooling the purified air 201 discharged by the devices 100c, 100d so that it remains longer near the ground, thus forming, for example, a mattress of purified air between the road and the building. Furthermore, maintenance and cleaning of the devices 100c, 100d, in particular of the at least one first collector, may, for example, be added to the maintenance of the bus.

[0121] Furthermore, when at least one of the first surface and the reference surface is coated with a coating comprising a photocatalyst capable of converting at least a portion of at least one of the agglomerates of microparticles and microparticles deposited on said first surface or said reference surface, respectively, into oxidation products CO2 and HO, it is advantageous for the frame to be, for example, partially or substantially transparent to at least one of visible light and UV, for example partially or substantially transparent to at least one of blue light and UV.

[0122] Furthermore, when the first surface and / or the reference surface of the at least one first collector comprises a plurality of plates arranged parallel to one another, it is advantageous for them to be arranged "vertically", i.e. parallel to the plane of Fig. 2B and Fig. 2C, in order to maximize the absorption of sunlight and thus the photocatalytic effect. The vertical arrangement of the plates also facilitates the alignment of the plates and limits buckling, which allows the air purifying device to function at high voltages without fear of electric arcs. Furthermore, when the plates are arranged vertically, it may prove advantageous for the upper part of the frame to be at least partially removable, for example via at least one sliding connection, in order to facilitate cleaning and / or replacement of the plates.

[0123] 3A illustrates an air cleaning assembly including multiple air cleaning devices 100e according to another embodiment of the present disclosure, where the devices 100e are, for example but not necessarily, substantially identical.

[0124] In this particular example, the assembly is configured to form a pollution prevention barrier, e.g., greater than about 40 meters in a longitudinal dimension. One such barrier is shown in Figure 3A and comprises a plurality of mechanically interconnected devices 100e, e.g., interconnected by welds, glue spots, bolts, screws, nuts. The barrier may be deployed, for example, along a highway (not shown), thereby protecting areas where pedestrians walk from pollution.

[0125] An example air cleaning device 100e suitable for the type of assembly shown in FIG. 3A is shown in more detail in FIGS. 3B and 3C.

[0126] Each air cleaning device 100e includes a frame 4 configured to enclose at least an ionizer, a coagulation chamber, and at least one first collector. As shown in Figures 3B and 3C, the ionizer includes a plurality of spikes 121 and a grid 122. An electric field of at least 100 kV / m is generated between the plurality of spikes 121 and the grid 122.

[0127] The device 100e may, for example, comprise only one collector. The first surface of the collector may comprise a plurality of plates 311 arranged parallel to one another and electrically connected to one another. Similarly, the reference surface of the collector may comprise a plurality of plates 312 arranged parallel to one another and electrically connected to one another. For example, all of the plates 311 of the first surface and the plates 312 of the reference surface are arranged alternately (311, 312, 311, 312, ...). The plates are, for example, "vertical", i.e. substantially perpendicular to the ground and to the plane of FIG. 3C. As described above in detail, this configuration makes it possible, for example, to minimize the air resistance of the device, to optimize the amount of sunlight to which the plates are exposed, and to limit buckling of the plates, among other advantages.

[0128] The device 100e may advantageously take the form of a shade-type urban street installation. The device 100e does not have to be configured to be mobile, but may be configured to remain permanently in an urban area to purify the air therein. As shown in Figures 3A-3C, the device 100e may for example form a shade with a central support pylon 105, for example of a height between 1 and 10 m, for example of about 2 m. Furthermore, the frame 4 may for example have dimensions of between about 1 m and about 5 m in width and between about 1 m and about 10 m in length, for example of about 3 m in width and about 5 m in length. The assembly of eight devices, each 5 meters long, thus allows the production of an air pollution barrier of 40 meters in length. The frame may for example be slightly widened on the side facing the highway. The frame may thus take the form of a pipe converging towards the outlet of the air cleaning device 100e. Thus, polluted air 200 from the highway can be directed accordingly to the device for treating a large volume of air at the inlet of the device, and the outflowing air flow 201 can be advantageously directed towards pedestrians.

[0129] Polluted air 200 from the highway enters the device. Outflow air 201 leaves the device 100e as purified air on the pedestrian side. The device 100e may include an airflow control system, for example including multiple fans 421.

[0130] Each fan 421 draws and / or pushes air between the first surface of the collector and the reference surface. The fans 421 advantageously make it possible to ensure a sufficient air flow even when the wind is low or there is no wind. In case of high winds, the fans 421 also make it possible to reduce the speed at which the air passes between the surfaces so that the air has time to be sufficiently decontaminated by the device 100e.

[0131] In some embodiments, both the first surface and the reference surface comprise substantially flat plates, creating low resistance to wind and to air circulating between said surfaces of the device 100e, thereby enabling the fan 421 of the airflow control system to consume relatively little energy.

[0132] The generator of the collector configured to apply said first potential to the first surface relative to a reference surface may further comprise means for the production of electricity, for example a photovoltaic panel 110 as shown in Figures 3A-3C. The photovoltaic panel 110 may for example provide current to at least one fan 421 and / or power the ionization device. The photovoltaic panel 110 may for example allow the device 100e to be self-sufficient in energy, which offers the advantage that no connection to an existing electrical network is necessary, limiting the operating costs of the device.

[0133] Additionally, the frame 4 of the apparatus 100e may include a protective grid surrounding at least the ionizer, the condensation chamber and the collector, as shown in Figures 3A-3C.

[0134] Another example of an air cleaning device is shown in Figure 4. Figure 4 is a cross-sectional view of an urban street installation fixed to the ground 600, namely a bus shelter 500 with an air cleaning device 100f on its roof.

[0135] The bus shelter 500 may provide the advantages, for example, of the presence of a mechanical support, the possibility of connection to an electric network, protection against wind 501. Furthermore, as shown in Fig. 4, the device 100f may comprise an airflow control system, for example comprising at least one fan 421 allowing the suction of air 200 from outside and ventilation for the occupants with purified air 201.

[0136] FIG. 4, showing a cross section of the bus shelter 500, further illustrates that the device 100f may be characterized, for example, by a "vertical" arrangement of the plates forming the first and reference surfaces of the collector, and / or a taper of the frame at the inlet, having the advantages discussed above.

[0137] Criteria for selecting a location for an air purification device according to the first aspect of the present specification may include, but are not limited to, for example, the availability of a large plot of land, the density of population where air pollution control would be beneficial, or the availability of a power supply, e.g., the availability of connection of the device to an electrical network, the availability of connection to a data network of the town or municipality including the aforementioned location.

[0138] While the present apparatus has been described through several detailed embodiments, it is understood that it includes variations, modifications and improvements that will be apparent to those skilled in the art, and that these variations, modifications and improvements must be included within the scope of the present invention as defined by the following claims. References

[0139] Reference 1: https: / / envinitygroup.com / Reference 2: Granted patent FR 3075665 Reference 3: U.S. Patent Application Publication No. 2013 / 025449 Reference 4: U.S. Patent Application Publication Specification No. 2020 / 376498 Reference 5: [Chem. Rev., 2014, 114(19), pp 9919-9986, ≪Understanding TiO2Photocatalysis: Mechanisms and Materials ≫]. Reference 6: https: / / fr.wikipedia.org / wiki / Effet_de_pointe Reference 7: https: / / fr.wikipedia.org / wiki / Effet_corona Reference 8: [Plasma Chem Plasma Process, 2017, 37, pp 1069-1090 ≪Synthesis of Carbon-Metal Multi-Strand Nanocomposites by Discharges in Heptane Between Two Metallic Electrodes≫]

Claims

1. - Approximately 1 m ２ The first surface (311) of the non-insulating material of larger size Ｓ ) and a first reference surface (312) of non-insulating material. Ｒ and a first generator configured to apply a first potential to the first surface of between about 5 kV and about 500 kV relative to the first reference surface to generate an electric field of about 10 kV / m or greater between the first surface and the first reference surface; an ionization device (12) configured to ionize a portion of the particles present in the air; an agglomeration chamber (21) configured to agglomerate at least a portion of the particles ionized by the ionizer into agglomerates of particles, the at least one first collector (31) being configured to collect at least a portion of the agglomerates of particles; a frame (4) configured to surround at least said ionizer (12), said condensation chamber (21) and said at least one first collector (31); Equipped with the ionizer (12) comprises a plurality of spikes (121), a grid (122), and a generator configured to apply a predetermined potential to the spikes of the plurality of spikes relative to the grid to generate an electric field of at least about 100 kV / m between the plurality of spikes (121) and the grid (122); Air purifier.

2. 2. An air purification device according to claim 1, wherein the coalescence chamber (21) comprises a tubular non-insulating material enclosure (211).

3. An air purifying device as described in claim 1, further comprising at least one second collector, wherein the at least one second collector: - Approximately 1 m ２ a second surface of non-insulating material of larger size; a second reference surface of non-insulating material; a second generator configured to apply a second potential to the second surface between about 5 kV and about 500 kV relative to the second reference surface to generate an electric field of about 10 kV / m or more between the second surface and the second reference surface; Equipped with the at least one second collector is configured to be located downstream of the first collector relative to the incoming airflow. Air purifier.

4. An air purifying device according to claim 1, the first surface (311) of the at least one first collector; Ｓ ) comprises a plurality of plates (311) arranged parallel to one another and electrically connected to one another; the first reference surface (312) of the at least one first collector; Ｒ ) comprises a plurality of plates (312) arranged parallel to one another and electrically connected to one another; at least some of the plates (311) of the first surface and at least some of the plates (312) of the first reference surface are arranged alternately in a first arrangement direction; Air purifier.

5. An air purifying device as described in claim 1, wherein the frame (4) is in the shape of a pipe having a variable cross section.

6. An air purifying device according to claim 1, wherein the frame (4) is an inlet chamber (41) arranged upstream of said ionizer (12) and adapted to direct an incoming air flow (200) into the interior of said air cleaning device; an outlet chamber (42) arranged downstream of said at least one first collector (31) with respect to said incoming air flow and configured to direct an outgoing air flow (201) outside said air cleaning device; An air purifying device comprising:

7. The air purification device of claim 1, wherein the first surface (311) of the at least one first collector. Ｓ ) and said first reference surface (312 Ｒ ) at least one of the agglomerates of the fine particles and the fine particles deposited on the first surface or the first reference surface, respectively, is oxidized by CO ２ and H ２ 1. An air freshening device coated with a coating comprising a photocatalyst capable of converting oxygen to oxygen.

8. An air purification device according to claim 1, comprising: a first collector (31) configured to direct an incoming air flow (200) through the first surface (311) of the at least one first collector (31). Ｓ ).

9. 9. An air purification device according to claim 8, wherein the airflow control system comprises at least one fan (421).

10. 10. An air purification device according to claim 9, wherein the at least one fan (421) is arranged at the level of an outlet chamber (42) arranged downstream of the at least one first collector (31) with respect to the incoming air flow.

11. An air purification device as described in claim 8, wherein the airflow control system includes at least one deflector (422a, 422b) configured to direct at least one of the incoming airflow (200) and the outgoing airflow (201).

12. An air purification device as described in claim 1, configured to take the form of an urban street installation, wholly or partially, of at least one type of shade and shelter.

13. An air purification device as described in claim 1, further comprising at least one fixing means (105) configured to mechanically connect the air purification device to a vehicle.

14. An air purifier assembly comprising a plurality of air purifier devices as described in claim 1, wherein the plurality of air purifier devices are mechanically connected to each other.

15. A method for purifying air using the air purifying device according to any one of claims 1 to 13, comprising: - placing said air cleaning device in and / or under and / or above and / or around the area to be decontaminated; - ionizing by means of said ionizer (12) at least a portion of said particles present in said air (200); - agglomerating, by means of the agglomeration chamber (21), at least a portion of the particles ionized by the ionization device (12) into agglomerates of particles; - by the generator of the at least one first collector (31), the first surface (311 Ｓ ) and the reference surface (312 Ｒ generating an electric field of about 10 kV / m or greater between the - collecting at least a portion of said agglomerates of fine particles by said at least one first collector (31); A method comprising:

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