Device for air purification by photocatalysis, and air treatment apparatus

Abstract

The present invention relates to an air purification device (1) comprising at least one textile sheet (3) within which at least one optical fibre (5) is woven with at least one thread (7) formed of photocatalyst fibres, each optical fibre (5) being configured to be supplied with light by a light source, each optical fibre (5) having radial light scattering means (8) in order to scatter light radially with respect to the direction of movement of the light in the optical fibre (5). The invention also relates to an air treatment apparatus comprising an air purification device (1) of this kind.

Description

[0001] DESCRIPTION

[0002] TITLE: PHOTOCATALYTIC AIR PURIFICATION DEVICE AND AIR TREATMENT APPARATUS

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to the field of depollution and purification of indoor air in homes, and in particular to an air purification device as well as to an air treatment apparatus equipped with such an air purification device.

[0005] It will be noted that, in this document, the terms "longitudinal", "transverse", "perpendicular", "parallel", "rotation", "horizontal", "vertical", "lower", "upper", "high", "lower", "secant", "coaxial", "convex", "concave", "plane" used to describe the apparatus according to the invention, refer to this device in a situation of use, when it is placed on a horizontal plane.

[0006] Pollutants are mainly composed of two categories. One includes particulate pollutants such as dust, bacteria, and molds, which are large in shape and have complex molecular structures, ranging in size from 0.01 micrometers to several hundred micrometers. The other category includes gaseous pollutants, for example, volatile emanations perceived by the sense of smell, such as odors, or volatile organic compounds (VOCs) such as chemical compounds, generally with a simple chemical structure. Gaseous pollutants can be composed of a variety of chemical elements. Their size is small and varies from a few angstroms to a few nanometers.

[0007] Advanced Oxidation Techniques (AOT) are used to oxidize volatile organic compounds (VOCs). The most effective are those that lead to the formation of hydroxyl radicals OH*, which have a higher oxidizing power than traditional oxidants. This is the case of photocatalysis. Photocatalysis consists of irradiating a semiconductor material (such as TiO2), which will allow the oxidation or reduction of VOCs in contact with the photocatalytic material. The energy provided by the light activates the semiconductor. The semiconductor is considered a catalyst.The principle is based on the absorption of a photon by the semiconductor solid, leading to the promotion of an electron from the valence band to the conduction band by releasing a vacancy, and thus forming free radicals which will either react with compounds present in the surrounding environment or recombine following various mechanisms, thus giving the solid oxidizing and reducing properties. Most organovolatile compounds as well as many pesticides, herbicides, surfactants and dyes are completely oxidized into less toxic products by this technique, until carbon dioxide CO2 and water H2O are obtained.

[0008] The main VOCs in ambient air are: formaldehyde, acetaldehyde, acetone, heptane, alcohols including isopropanol, decane, benzene, toluene.

[0009] STATE OF THE ART

[0010] Filters for treating VOCs, such as activated carbon filters, are known. Such filters are, for example, integrated into air treatment units. However, these filters have a limited lifespan and must be replaced regularly. Furthermore, replacing these filters is expensive, and they are generally not recyclable.

[0011] Air treatment devices that use photocatalysis technology are also known. However, these devices often release VOCs as by-products, whereas on the contrary, they are supposed to eliminate them and purify the air. It is difficult to understand why an air purifier or air purifier releases VOCs even if the VOCs released are different in nature and / or quantity from what was initially present in the air before purification. The major disadvantage of these devices is therefore the production of by-products, which can sometimes be more dangerous than the initial molecules, for example heptane, which can form formaldehyde when degraded. To reduce the formation of these toxic by-products, known air treatment devices propose lowering the operating speed (gas speed or light intensity) until the VOC content in the air to be purified drops below a certain value.It is also unfortunate that the air treatment unit cannot be operated precisely when it is needed most, i.e., when there is a high concentration of VOCs. As a result, gaseous pollutants cannot be absorbed and removed effectively. In addition, the accumulation of particulate pollutants on the surface of the gaseous removal filter could lead to other problems, such as the appearance of incubation zones for bacterial growth, or a loss of filter efficiency over time.

[0012] STATEMENT OF THE INVENTION

[0013] The invention proposes to resolve these drawbacks by proposing an air purification device that is made in a simple manner while being permanently effective in eliminating pollutants such as VOCs.

[0014] According to a first aspect, the invention proposes an air purification device comprising at least one textile sheet, in which at least one optical fiber is woven with at least one thread formed from photocatalyst fibers, each optical fiber being configured to be supplied with light by a light source, each optical fiber having radial light diffusion means in order to diffuse light radially relative to the direction of movement of the light in the optical fiber.

[0015] Thus, the air purification device is produced in a particularly simple manner while being particularly effective in removing pollutants such as VOCs. Indeed, the arrangement in the form of a textile sheet of at least one optical fiber and at least one thread formed from photocatalyst fibers, makes it possible to maximize photocatalysis while being simple to manufacture, by maximizing the probability that polluted air encounters a photocatalytic site activated by light, by significantly increasing the contact time of the pollutants with photocatalytic sites. Thus, a single element, namely the textile sheet, makes it possible to carry out photocatalysis, because it incorporates both at least one optical fiber and at least one thread formed from photocatalyst fibers. Such an air purification device also has the advantage of being permanent, and does not require regular replacement.Thus, a device, for example an air treatment device, equipped with such an air purification device, is easier to maintain, since it does not require regular replacement of the air purification device.

[0016] According to a second aspect, the invention also proposes an air treatment apparatus comprising:

[0017] - an air circulation duct between an air inlet and an air outlet,

[0018] - a light source, and

[0019] - an air purification device as previously described and arranged in the air circulation duct, in which each optical fiber is supplied with light by the light source.

[0020] The invention is advantageously and optionally supplemented by the following characteristics, taken alone or in any of their technically possible combinations:

[0021] - The photocatalyst consists of at least one photocatalyst material.

[0022] - The photocatalyst consists only of photocatalyst material. These can be the same or different photocatalysts.

[0023] - The photocatalyst is formed solely of at least one catalyst material with photocatalytic action.

[0024] - The photocatalyst is a catalyst with photo-catalytic action, which is not metallic.

[0025] - Photocatalyst fibers are made of photocatalyst only.

[0026] - Photocatalyst fibers exclude any material other than the photocatalyst, with the exception of materials inherent in the photocatalyst manufacturing process. - Photocatalyst fibers include the photocatalyst in their mass.

[0027] - The at least one thread is made of photocatalyst fibers. These may be identical or different photocatalyst fibers.

[0028] - The at least one thread is formed solely of photocatalyst fibers.

[0029] - The at least one thread formed from photocatalyst fibers is not metallic.

[0030] - The at least one yarn formed from photocatalyst fibers is not a yarn coated with photocatalyst but a yarn made from photocatalyst fibers.

[0031] - The at least one yarn formed from photocatalyst fibers is preferably obtained by a continuous preparation process where a photocatalyst dispersion is extruded and solidified. Preferably, the photocatalyst dispersion is an aqueous dispersion of at least one vinyl alcohol polymer. Advantageously, the extrusion of the photocatalyst dispersion is carried out continuously and unidirectionally in a bath capable of causing the fiber to solidify. Washing and drying steps may be envisaged. Thus, a photocatalyst fiber is obtained, the length of which can reach several hundred meters.

[0032] - The at least one thread formed from photocatalyst fibers is a binding thread. Thus, each textile sheet is produced in a simple manner.

[0033] - The radial light diffusion means are formed by surface alterations of the optical fiber. Thus, the radial light diffusion means are produced in a particularly simple manner.

[0034] - Each optical fiber is formed from a material selected from the group comprising polymethyl methacrylate (PMMA), polycarbonate (PC) and cycloolefins (COP), preferably polycarbonate (PC).

[0035] - A free end of each optical fiber is configured to be arranged opposite a light source to transmit light and radially emit light at the radial light diffusion means to activate the photocatalyst.

[0036] - Surface alterations to each optical fiber can be achieved in various ways, including sandblasting, chemical etching, or fusion using high-intensity light radiation such as a laser. Of course, such alterations can also be achieved by many other mechanical or chemical processes.

[0037] - The surface alterations of each optical fiber can be distributed symmetrically or asymmetrically (progressively). Indeed, in order to achieve homogeneous illumination in the textile web, and therefore homogeneous activation of the photocatalyst in the textile web, the surface density or the dimension of the alterations can vary from one area of ​​the optical fiber to another. For example, the surface density of the alterations is low on the side of the light source and increases as one moves away from the light source.

[0038] - The textile web is made up of warp and weft threads, each optical fiber forming a warp thread and each thread formed from photocatalyst fibers forming at least one weft thread. Thus, the textile web is made in a simple manner while being particularly effective in eliminating pollutants such as VOCs.

[0039] - Each warp thread is an optical fiber. This simplifies manufacturing and improves the efficiency of the textile web.

[0040] - Each weft thread is made entirely of photocatalyst fibers. This simplifies manufacturing and improves the efficiency of the textile web.

[0041] - The textile fabric is woven in a plain weave. This makes the textile fabric particularly simple to make and particularly effective at removing pollutants such as VOCs. - The textile fabric is woven in a satin weave. This makes the textile fabric particularly effective at removing pollutants such as VOCs.

[0042] - The textile sheet has two opposite visible faces, optical fibers and threads formed from photocatalyst fibers held by binding threads being visible on the two opposite faces of the sheet.

[0043] - The textile sheet comprises a superposition of textile layers, each of the layers being formed of optical fibers and threads formed of photocatalyst fibers held by binding threads.

[0044] - The textile sheet has two opposite visible faces, the optical fibers being visible on one face and the threads formed from photocatalyst fibers being visible on the other face.

[0045] - The textile sheet has two opposite visible faces, the optical fibers being visible on one of the faces and the threads formed from photocatalyst fibers being visible on both faces.

[0046] - The textile sheet has two opposite visible faces, the optical fibers being visible on both faces and the threads formed from photocatalyst fibers being visible on one of the two faces.

[0047] - The air purification device comprises means for holding the textile sheet or each textile sheet in position, the means for holding in position preferably comprising a frame, the means for holding in position preferably comprising spacers configured to space the textile sheets apart. Thus, the air purification device is of modular design, which facilitates its assembly or integration into a device, such as an air treatment device.

[0048] - The photocatalyst is activated by light, which may be of the ultraviolet type, via at least one optical fiber configured to diffuse light. A simple cutting of the textile sheet to the dimensions of the air purification device or the means for holding it in position makes it possible to produce air purification devices of any size.

[0049] - The textile tablecloth has a transverse dimension less than or equal to 20 centimeters.

[0050] - The textile tablecloth has a longitudinal dimension less than or equal to 1 meter.

[0051] - The photocatalyst fibers have a smaller dimension of at least 10 micrometers. Thus, the strength of the yarn formed by the photocatalyst fibers is improved.

[0052] - The photocatalyst fibers are macroscopic. For the purposes of the present invention, the term macroscopic fiber means a strand in which the smallest dimension is at least 10 micrometers. Preferably, the strand has two average dimensions orthogonal to its longitudinal axis, the first average dimension (corresponding to its width) varies from 30 to 60 micrometers, preferably from 40 to 50 micrometers, and the second average dimension (corresponding to its thickness) varies from 10 to 40 micrometers, preferably from 10 to 20 micrometers.

[0053] - The photocatalyst is a semiconductor material. Thus, the photocatalyst is made in a simple way.

[0054] - The photocatalyst comprises at least one oxide chosen from the group consisting of TiO2, ZnO, CeO2. Thus, the photocatalyst is produced in a simple manner while being particularly effective.

[0055] - The photocatalyst comprises at least partially crystalline TiO2, preferably predominantly crystalline TiO2. Thus, the photocatalyst is particularly effective.

[0056] - The air purification device comprises several textile layers superimposed and spaced apart by at least a predetermined value such that air to be purified circulates between the textile layers, preferably the predetermined value being greater than or equal to 5 millimeters. Thus, the spacing of a predetermined value present between the textile layers increases the efficiency of the air purification device, such an air purification device making it possible to purify a high air flow rate while being of compact construction. The air to be purified circulates between the textile layers in order to come into contact with the photocatalyst. Advantageously, the air circulation is carried out according to a flow at a low but swirling average flow rate. These textile layers allow the air to circulate along the textile layers and / or between the textile layers, in a direction parallel to the textile layers.This maximizes the contact of the air to be purified with the photocatalyst. If the textile layers are too far apart, the air only circulates in a laminar manner and the probability of contact between the air and the photocatalyst is reduced, reducing the efficiency of the purification. Advantageously, the textile layers are close enough together to maximize the contact of the air with the photocatalytic surface, and cause vortices in the air flow.

[0057] - The textile sheets are arranged in parallel layers, preferably flat or non-flat.

[0058] - Textile tablecloths are curved.

[0059] - Other arrangements of each textile sheet can be envisaged, for example in the form of a roll where each textile sheet is rolled up on itself like a roll of carpet.

[0060] - Optical fibers are powered by a single light source. This simplifies manufacturing, as only one light source is used.

[0061] - The light source may be composed of several identical or different light sources, which may be of different natures, and in particular be in the form of light-emitting diodes (LEDs) or extended sources such as incandescent lamps, fluorescent tubes or discharge tubes incorporating a gas such as neon. - The light source supplies light to a free end of each optical fiber.

[0062] - The air treatment unit includes several air inlets, identical or different.

[0063] - The air treatment unit includes several air outlets, identical or different.

[0064] - The air treatment device is a domestic appliance comprising a casing forming the outer casing of the air treatment device.

[0065] - The air treatment unit is configured to be movable during operation. This simplifies handling and movement of the unit. In fact, the air treatment unit is movable and not fixed to a support. Thus, the air treatment unit can be carried by a user in order to move it, either by pushing it with the foot or by grasping it with the hands, whether the air treatment unit is in operation or not.

[0066] - The air handling unit is an individual domestic appliance and not a centralized air conditioning system, for example in a hospital, airport, shopping center, metro or train station.

[0067] - The air treatment unit is an individual portable unit suitable for small spaces such as a single-family home or a caravan.

[0068] - The light source is a UV light source. Thus, the photocatalytic action is carried out in a simple way while being particularly effective.

[0069] - The light source may comprise a collector capable of focusing natural sunlight in a point or linear manner towards at least one free end of at least one optical fibre.

[0070] - The light source is made of an LED. This makes the light source simple to design and highly efficient. - The light source can be made of a UVA, UVB, or UVC LED. This system combines minimal energy consumption with significant efficiency.

[0071] - The air treatment apparatus further comprises a volatile organic compound analyzer and an automatic adjustment member, which is configured to automatically adjust, depending on the volatile organic compound content analyzed by the analyzer, the speed of the air entering the air inlet and / or the light intensity of the light source.

[0072] - Each textile sheet is arranged parallel to the air flow in the air circulation duct. Thus, the air flow flows along at least one textile sheet, in other words tangentially to it, and the photocatalytic action is improved.

[0073] - Each textile sheet is arranged transversely to the air flow in the air circulation duct. Thus, the air flow necessarily passes through each textile sheet, and the photo-catalytic action is improved.

[0074] - The air treatment device further comprises a particle filter. Such a particle filter separates particles from the air by mechanical action, retaining on the surface particles whose diameter is greater than the diameter of the pores of the filter and being able to retain particles whose diameter is smaller than that of the pores of the filter by the action of electrostatic forces.

[0075] - The particle filter is arranged upstream of the air purification device, depending on the air movement between the air inlet and the air outlet. This prevents the air purification device from becoming clogged with particles.

[0076] - The particulate filter is a HEPA filter, an acronym for High Efficiency Particulate Air. The HEPA filter is preferably capable of filtering, in one pass, at least 99.97% of particles with a diameter greater than or equal to 0.3 micrometers. - The air treatment device further comprises an activated carbon filter. Thus, the air purification device makes it possible to more effectively eliminate pollutants passing through the activated carbon filter. Activated carbon filters were developed in response to industrial emissions of volatile organic compounds (VOCs). In an activated carbon adsorption system, contaminated air is directed onto a bed of carbon. The carbon extracts the VOCs from the air and adsorbs them, holding them on the surface.

[0077] - The activated carbon filter is positioned downstream of the air purification device, depending on the air movement between the air inlet and the air outlet. Thus, the activated carbon filter eliminates "by-product" pollutants passing through the air purification device, which could be produced exceptionally (for example in connection with an abnormal peak in pollutant concentrations). Activated carbon filters were developed in response to industrial emissions of volatile organic compounds (VOCs). In an activated carbon adsorption system, contaminated air is directed onto a bed of carbon. The carbon extracts the VOCs from the air and adsorbs them, keeping them on the surface. Since this activated carbon filter is only present to act exceptionally, it is a permanent part of the device, and not a consumable.

[0078] - The air treatment unit also includes a formaldehyde filter. This way, any formaldehyde that might occasionally escape from the air purification device would be captured.

[0079] - The air treatment device further comprises a dehumidifier. Such a dehumidifier serves to reduce the moisture content of the air and increases the efficiency of the air treatment device.

[0080] - The air treatment apparatus further comprises an air moving member configured to move air from the air inlet to the air outlet. Thus, the air movement is forced between the air inlet and the air outlet.

[0081] - The air movement member is, for example, a radial flow or mixed flow turbine, or a fan, arranged downstream of the air purification device. In this case, a motor fan unit may be arranged on the air outlet side, above the air purification device.

[0082] - The air treatment device further comprises one or more fans, agitators or tabulators. Thus, the presence of one or more fans, agitators or tabulators makes it possible to generate turbulence in the air flow passing through the air purification device, for example so as to generate vortices between the textile layers, which further increases its efficiency.

[0083] - The air treatment unit has a volume of less than 1 m 3 , preferably less than 0.8 m 3 , more preferably less than 0.6 m 3 .

[0084] - The air treatment device has a mass less than or equal to 30 kg, preferably less than 20 kg, more preferably less than 6 kg.

[0085] - The air treatment unit has an apparent textile surface area of ​​at least 4000 cm 2 , preferably at least 6000 cm2 , more preferably at least 8000 cm 2 . By apparent surface, we mean the surface of the textile fabric in contact with the air flow.

[0086] - The air flow moving in the air purification device has a speed of less than 1 m / s, preferably less than 0.5 m / s, more preferably less than 0.2 m / s.

[0087] - A contact time of the pollutants with the textile sheet is at least 0.5 s and can be as long as possible, for example by a flow of the air flow parallel to the textile sheet, either parallel to each optical fiber or orthogonal to each optical fiber, or by a swirling flow of the air flow to be treated. Thus the air flow to be treated has a rotational speed at all points. The swirling flow makes it possible to increase the average contact time between the air to be treated and the air purification device. The longer the contact time, the less risk there is of producing polluting by-products. DESCRIPTION OF THE FIGURES

[0088] Other characteristics, aims and advantages of the invention will emerge from the detailed description below, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings, given as non-limiting examples and in which:

[0089] [Fig. 1] is a schematic top view of an exemplary embodiment of an air purification device;

[0090] [Fig. 2] is a top view of an exemplary embodiment of a light source supplying light to the air purification device;

[0091] [Fig. 3] is a schematic perspective view of an exemplary embodiment of an air treatment device;

[0092] [Fig. 4] is a schematic diagram of the air circulation in the air handling unit;

[0093] [Fig. 5] is a schematic diagram of the air circulation in the air purification device of the air treatment unit.

[0094] Throughout the figures, similar elements are designated by identical references.

[0095] DETAILED DESCRIPTION OF THE INVENTION

[0096] Figure 1 shows an air purification device 1. The air purification device 1 comprises at least one textile web 3, in which at least one optical fiber 5 is woven with at least one yarn 7 formed of photocatalyst fibers. In this example, the air purification device comprises a textile web 3, in which a plurality of optical fibers 5 are woven with a yarn 7 formed of photocatalyst fibers.

[0097] The textile web 3 is formed of warp threads and weft threads, each optical fiber 5 forming a warp thread and each thread 7 formed of photocatalyst fibers forming at least one weft thread. More precisely in this example, each warp thread is an optical fiber 5, and each weft thread is entirely formed of photocatalyst fibers. Advantageously, the textile web 3 is woven in plain weave.

[0098] Preferably, the at least one yarn 7 formed of photocatalyst fibers is a binding yarn. More precisely, a single yarn 7 formed of photocatalyst fibers passes alternately above and below optical fibers 5 in a straight line and forms a weft yarn. Once the last optical fiber 5 is reached, the yarn 7 forms a meander in order to pass again above and below the optical fibers 5 and forms a new weft yarn, and so on.

[0099] Alternatively, other weaving patterns are possible:

[0100] - Textile tablecloth 3 can be woven in satin weave.

[0101] - The textile sheet 3 may have two opposite visible faces, optical fibers 5 and threads 7 formed from photocatalyst fibers held by binding threads being visible on the two opposite faces of the sheet.

[0102] - The textile sheet 3 may comprise a superposition of textile layers, each of the layers being formed of optical fibers 5 and threads 7 formed of photocatalyst fibers held by binding threads.

[0103] - The textile sheet 3 may have two opposite visible faces, the optical fibers 5 being visible on one of the faces and the threads 7 formed from photocatalyst fibers being visible on the other face.

[0104] - The textile sheet 3 may have two opposite visible faces, the optical fibers 5 being visible on one of the faces and the threads 7 formed from photocatalyst fibers being visible on both faces.

[0105] - The textile sheet 3 may have two opposite visible faces, the optical fibers 5 being visible on both faces and the threads 7 formed from photocatalyst fibers being visible on one of the two faces.

[0106] Advantageously, each optical fiber 5 has radial light diffusion means 8 in order to diffuse light radially relative to the direction of movement of the light in the optical fiber 5.

[0107] Each optical fiber 5 is configured to be supplied with light by a light source 9, as shown for example in FIG. 2. A free end of each optical fiber 5 is for example configured to be arranged opposite the light source 9 to transmit the light and emit light radially at the level of the radial light diffusion means 8 to activate the photocatalyst.

[0108] For example, each optical fiber 5 is formed from a material selected from the group comprising polymethyl methacrylate (PMMA), polycarbonate (PC) and cycloolefins (COP), preferably polycarbonate (PC). In this example, each optical fiber 5 is formed from polycarbonate (PC).

[0109] As shown for example in Figure 2, the air purification device 1 preferably also comprises means 13 for holding the textile sheet 3 in position. The means 13 for holding the textile sheet in position preferably comprise a frame.

[0110] The photocatalyst consists of at least one photocatalyst material. In this example, the photocatalyst is formed solely of at least one photocatalytic catalyst material. Thus, the photocatalyst fibers are formed solely of photocatalyst.

[0111] Furthermore, the photocatalyst is a photocatalytic catalyst, which is not metallic. Thus, the at least one wire 7 formed from photocatalyst fibers is not metallic.

[0112] Advantageously, the photocatalyst consists solely of photocatalyst material. These can be identical or different photocatalysts. In other words, it can be a single photocatalyst material or different photocatalyst materials.

[0113] Advantageously, the photocatalyst fibers exclude any material other than the photocatalyst, with the exception of materials inherent in the manufacturing process of the photocatalyst.

[0114] Advantageously, the photocatalyst fibers comprise the photocatalyst in their mass. Advantageously, the at least one yarn 7 formed of photocatalyst fibers is made of photocatalyst fibers. These may be identical or different photocatalyst fibers.

[0115] Advantageously, the at least one thread 7 formed from photocatalyst fibers is formed solely from photocatalyst fibers.

[0116] Advantageously, the at least one yarn 7 formed from photocatalyst fibers is not a yarn coated with photocatalyst but a yarn made from photocatalyst fibers.

[0117] The at least one yarn 7 formed from photocatalyst fibers is preferably obtained by a continuous preparation process where a photocatalyst dispersion is extruded and solidified. Preferably, the photocatalyst dispersion is an aqueous dispersion of at least one vinyl alcohol polymer. Advantageously, the extrusion of the photocatalyst dispersion is carried out continuously and unidirectionally in a bath capable of causing the fiber to solidify. Washing and drying steps may be envisaged. Thus, a photocatalyst fiber is obtained, the length of which can reach several hundred meters.

[0118] In this example, the photocatalyst fibers have a smallest dimension of at least 10 micrometers. Thus, the photocatalyst fibers are macroscopic. In other words, a macroscopic fiber is a strand in which the smallest dimension is at least 10 micrometers.

[0119] Preferably, the strand has two average dimensions orthogonal to its longitudinal axis, the first average dimension (corresponding to its width) varying from 30 to 60 micrometers, preferably from 40 to 50 micrometers, and the second average dimension (corresponding to its thickness) varying from 10 to 40 micrometers, preferably from 10 to 20 micrometers.

[0120] The photocatalyst is preferably a semiconductor material. In this example, the photocatalyst comprises at least one oxide selected from the group consisting of TiO2, ZnO, CeO2. Advantageously, the photocatalyst comprises at least partially crystalline TiO2, preferably predominantly crystalline TiO2. Preferably, the photocatalyst is made of at least partially crystalline TiO2, preferably predominantly crystalline TiO2.

[0121] The photocatalyst is activated by light which may be of the ultraviolet type, via at least one optical fiber 5.

[0122] A simple cutting of the textile sheet 3 to the dimensions of the air purification device 1 or the position holding means 13 makes it possible to produce air purification devices of any size. Advantageously, the textile sheet 3 has a transverse dimension less than or equal to 20 centimeters and a longitudinal dimension less than or equal to 1 meter.

[0123] The radial light diffusion means 8 are for example formed by alterations to the surface of the optical fiber 5. The alterations to the surface of each optical fiber 5 can be carried out in various ways, and in particular by sandblasting, chemical etching or fusion processes using high-intensity light radiation such as a laser. Obviously, such alterations can also be carried out by many other mechanical or chemical processes.

[0124] The surface alterations of each optical fiber 5 may be distributed symmetrically or asymmetrically (progressively). Indeed, in order to achieve homogeneous lighting in the textile sheet 3, and therefore homogeneous activation of the photocatalyst in the textile sheet 3, the surface density or the dimension of the alterations may vary from one zone to another of the optical fiber 5.

[0125] For example, the surface density of alterations is low on the side of light source 9 and increases away from light source 9.

[0126] The light source 9 is preferably single. Alternatively, the light source 9 may be composed of several identical or different light sources, which may be of different natures, and in particular be in the form of light-emitting diodes (LEDs) or extended sources such as incandescent lamps, fluorescent tubes or discharge tubes incorporating a gas such as neon.

[0127] In this example, the light source 9 supplies light to a free end of each optical fiber 5. In this example, the light source 9 is a UV light source, and comprises an LED. For example, the light source 9 can be made with a UVA, UVB or UVC LED.

[0128] Alternatively or in a complementary manner, the light source 9 may comprise a collector capable of focusing natural solar light in a point or linear manner towards at least one free end of at least one optical fiber.

[0129] Figure 3 represents a first exemplary embodiment of an air treatment device 15. Such an air treatment device 15 comprises an air purification device 1 as previously described, a light source 9 as previously described, and an air circulation duct 17 between an air inlet 19 and an air outlet 21.

[0130] Alternatively, the air treatment device 15 comprises several air outlets, identical or different, and the air treatment device 15 comprises several air inlets, identical or different.

[0131] The air purification device 1 is arranged in the air circulation duct 17. Each optical fiber 5 is supplied with light by the light source 9.

[0132] In this example, the air treatment device 15 is a domestic appliance comprising a casing 23 forming the outer casing of the air treatment device 15.

[0133] Preferably, the air treatment device 15 is configured to be movable during operation. Thus, the air treatment device 15 is an individual domestic device and not a centralized air conditioning system, for example in a hospital, an airport, a shopping center, a metro or train station. Furthermore, the air treatment device 15 is preferably an individual portable device suitable for small spaces such as that of an individual dwelling or a caravan. Thus, the air treatment device 15 has a volume of less than 1 m3 , preferably less than 0.8 m 3 , more preferably less than 0.6 m 3 .

[0134] Furthermore, the air treatment device has a mass less than or equal to 30 kg, preferably less than 20 kg, more preferably less than 6 kg.

[0135] The air treatment apparatus 15 further comprises an air movement member 25. The air movement member 25 is configured to move air from the air inlet 19 to the air outlet 21. The air movement member 25 is for example a radial flow or mixed flow turbine, or a fan, arranged downstream of the air purification device 1. In this case, as shown in FIG. 3, a motor-fan unit 26 may be arranged on the side of the air outlet 21, above the air purification device 1.

[0136] In the example shown in Figure 3, the air purification device 1 comprises several textile sheets 3 superimposed and spaced apart by at least a predetermined value such that air to be purified circulates between the textile sheets 3. Preferably, the predetermined value is greater than or equal to 5 millimeters. In this example, the textile sheets 3 are arranged in parallel layers. The parallel layers may be flat or non-flat. Thus, the textile sheets 3 are not necessarily flat and may be curved.

[0137] Advantageously, the position holding means 13 hold each textile sheet 3, and preferably comprise a frame. The position holding means 13 preferably comprise spacers configured to space the textile sheets 3 apart.

[0138] Alternatively, other arrangements of each textile sheet may be envisaged, for example in the form of a roll where each textile sheet is rolled up on itself in the manner of a carpet roll. Furthermore, in this example, each textile sheet 3 is arranged parallel to the air flow in the air circulation duct 17. Alternatively, each textile sheet is arranged transversely to the air flow in the air circulation duct.

[0139] In this example, the air treatment device 15 has an apparent textile sheet surface area of ​​at least 4000 cm 2 , preferably at least 6000 cm 2 , more preferably at least 8000 cm 2 .

[0140] For example, the air flow moving in the air purification device 1 has a speed of less than 1 m / s, preferably less than 0.5 m / s, more preferably less than 0.2 m / s. Thus, a contact time of the pollutants with the textile sheet 3 is at least 0.5 s.

[0141] The air treatment apparatus further comprises a volatile organic compound analyzer 27 and an automatic adjustment member 29. The automatic adjustment member 29 is configured to automatically adjust, as a function of the volatile organic compound content analyzed by the analyzer 27, the speed of the air entering the air inlet 19 and / or the light intensity of the light source 9.

[0142] Preferably, as shown in FIG. 4, the air treatment device 15 further comprises at least one filter 31. The filter 31 is arranged, depending on the movement of the air between the air inlet 19 and the air outlet 21, upstream or downstream of the air purification device 1.

[0143] For example, a filter 31 can be placed upstream of the air purification device 1. In this case, a particle filter, of the HEPA filter type, can in particular be provided.

[0144] Advantageously, at least one filter, such as an activated carbon filter or a formaldehyde filter, is arranged downstream of the air purification device 1.

[0145] Alternatively or additionally, the air treatment apparatus 15 further comprises a dehumidifier. For example, as shown in FIG. 5, the air treatment apparatus 15 further comprises one or more fans 31, agitators or turbulators. Thus, the air is circulated according to a flow at a low average flow rate but swirling between the textile sheets 3. Optionally, the air treatment apparatus 15 also comprises at least one deflector 33, configured to reduce air turbulence before the air outlet 21.

Claims

CLAIMS 1. Air purification device (1), characterized in that it comprises at least one textile sheet (3), in which at least one optical fiber (5) is woven with at least one thread (7) formed of photocatalyst fibers, each optical fiber (5) being configured to be supplied with light by a light source (9), each optical fiber (5) having radial light diffusion means (8) in order to diffuse light radially relative to the direction of movement of the light in the optical fiber (5).

2. Air purification device (1) according to claim 1, wherein the at least one yarn (7) formed from photocatalyst fibers is a binding yarn.

3. Air purification device (1) according to claim 1 or 2, wherein the radial light diffusion means (8) are formed by surface alterations of the optical fiber (5).

4. Air purification device (1) according to any one of claims 1 to 3, in which the textile sheet (3) is formed of warp threads and weft threads, each optical fiber (5) forming a warp thread and each thread (7) formed of photocatalyst fibers forming at least one weft thread.

5. Air purification device (1) according to claim 4, wherein the textile sheet (3) is woven in plain weave or satin weave.

6. Air purification device (1) according to any one of claims 1 to 5, which comprises means for holding the textile sheet (3) in position (13), the means for holding the textile sheet (3) in position preferably comprising a frame.

7. Air purification device (1) according to any one of claims 1 to 6, which comprises several textile sheets (3) superimposed and spaced by at least a predetermined value so that air to be purified circulates between the textile layers (3), preferably the predetermined value being greater than or equal to 5 millimeters.

8. Air purification device (1) according to claim 7, wherein the position holding means (13) hold each textile sheet (3) in position and comprise a frame and spacers configured to space the textile sheets (3) apart.

9. Air purification device (1) according to any one of claims 1 to 8, wherein the photocatalyst fibers have a smallest dimension of at least 10 micrometers.

10. Air purification device (1) according to any one of claims 1 to 9, wherein the photocatalyst is a semiconductor material.

11. Air purification device (1) according to any one of claims 1 to 10, wherein the photocatalyst comprises at least one oxide chosen from the group consisting of TiCh, ZnO, CeCh.

12. Air purification device (1) according to any one of claims 1 to 11, wherein the photocatalyst comprises at least partially crystalline TiCh, preferably predominantly crystalline TiCh.

13. Air treatment apparatus (15) comprising: - an air circulation duct (17) between an air inlet (19) and an air outlet (21), - a light source (9), and - an air purification device (1) according to any one of claims 1 to 12 arranged in the air circulation duct (17), in which each optical fiber (5) is supplied with light by the light source (9).

14. Air treatment apparatus (15) according to claim 13, which is a domestic appliance comprising a casing (23) forming the outer casing of the air treatment apparatus (15).

15. Air treatment apparatus (15) according to claim 13 or 14, wherein the light source (9) is a UV light source.

16. Air treatment apparatus (15) according to any one of claims 13 to 15, wherein the light source (9) comprises an LED.

17. Air treatment apparatus (15) according to any one of claims 13 to 16, which further comprises: - an analyzer (27) of volatile organic compounds and - an automatic adjustment member (29), which is configured to automatically adjust, depending on the content of volatile organic compounds analyzed by the analyzer (27), the speed of the air entering the air inlet (19) and / or the light intensity of the light source (9).

18. Air treatment apparatus (15) according to any one of claims 13 to 17, wherein each textile sheet (3) is arranged parallel to the air flow in the air circulation duct (17).

19. Air treatment apparatus (15) according to any one of claims 13 to 17, wherein each textile sheet (3) is arranged transversely to the air flow in the air circulation duct (17).

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