Air particle capture system within a confined public transport station with filtration device integrated within the confined station

Abstract

The present invention relates to a system for capturing particles (1) from the air within a confined station, in particular an underground station. The capture system comprises suction means (2), a filtration device (4), and means for distributing the filtered air (9). The filtration device (4) comprises at least one granular bed (5). In addition, the filtration device (4) is integrated into the structure of the confined station (for example a wall, or a door support). Figure 1 to be published

Description

Title of the invention: System for capturing air particles within a confined public transport station with filtration device integrated within the confined station Technical field

[0001] The present invention relates to the field of air treatment in confined or semi-confined spaces, such as an underground public transport station, in particular in the case of underground transport networks of the rail type (for example: metro, RER for “Réseau Express Régional” of Île-de-France).

[0002] In the case of underground rail transport networks, these confined or semi-confined spaces include stations, corridors, trains, tunnels, commercial premises, technical premises and train repair centres.

[0003] Generally speaking, these spaces can be frequented by a transient population, users, and / or by a more or less permanent population, such as operating personnel or traders.

[0004] The particles present in the atmosphere or ambient air can have many origins and / or result from complex evolution processes involving large-scale transport phenomena and photochemical transformation in particular. In particular, particles suspended in the air can also come from the wear of tires or vehicle braking components, or quite simply from the degradation of road or railway surfaces (dust). Their small size, of the order of a few microns, explains why they remain suspended in the air. For underground railway enclosures (EFS), the major constituents identified are different materials including iron, elemental carbon and organic carbon. Terrigenic dust, particularly composed of silica, linked to soil erosion, can also be added.

[0005] Furthermore, if the means of transport are driven by heat engines, the combustion of fuel in these heat engines is a significant source of particle emissions, such as fine particles rich in PAHs (polycyclic aromatic hydrocarbons), but also soot particles, metal particles, particles resulting from nucleation processes from several types of volatile chemical species, or even a combination of these different types of particles.

[0006] These particles, the sources of which are very numerous, present a very large variability in size, ranging from nanometers to several tens of microns, and a very large variability in composition which can be organic and / or inorganic. In particular In particular, fine particles represent one of the main risk factors linked to urban air pollution for developing cancer. Fine particles can be particularly toxic because they penetrate deep into the lungs and bronchial tree.

[0007] In these various confined or semi-confined places, ventilation and extraction and / or air supply systems are generally installed, the aim of which is to improve the quality of the air, by renewing it with blown-in “fresh” air taken from outside and / or by extracting and rejecting stale air outside. In certain cases, decontamination of the stale air is carried out in so-called “bypass” installations, the air being extracted, decontaminated, then reinjected.

[0008] However, these systems are insufficient to guarantee correct air quality in these confined spaces. For example, for metro-type rail networks, urban outdoor air is taken to renew the air. However, urban air can already present a significant level of pollution, particularly in terms of fine particles but also in terms of gaseous pollutants (such as NOx, VOCs, or sulfur derivatives such as sulfur oxides SOx), in particular due to car traffic, urban heating, or nearby industrial activities.

[0009] There is therefore a real need to treat the air arriving in and / or extracted from these confined spaces, to improve the quality of the air in these spaces, and / or the air in their vicinity. Prior art

[0010] Several technologies have been developed to treat the air in these confined or semi-confined spaces.

[0011] Patent application FR 3117375 (WO2022 / 122463) relates to a device and method for depolluting the air of confined or semi-confined environments by means of an improved TFP filter (Turbulent Flow Precipitator in English, and Precipitateur à Flux Turbulent in French). Such a system requires creating turbulence in the gas flow, and means for trapping particles. In the system, the air flow circulates parallel to the filter, therefore, filtration is not maximum. In addition, this patent application does not provide for a specific arrangement of the particle capture system in an underground public transport station.

[0012] Patent application FR3046663 relates to a method for collecting fine particles generated during the braking of a train. The method comprises steps of suction, purification, and distribution of the filtered air. This document provides for the implementation of a HEPA filter (high-efficiency particulate air filter). However, such a filter has a high pressure drop, and requires a specific installation within the underground transport station, while space is limited. For example, the installation may hinder the movement of users on the platform, which has an impact on safety and the flow of transport. Summary of the invention

[0013] The aim of the invention is to capture particles from the air within a confined public transport station, by means of an efficient, robust, economical, low-noise and space-saving system within the transport station. For this purpose, the present invention relates to a system for capturing particles from the air within a confined station, in particular an underground station. The capture system comprises suction means, a filtration device, and means for distributing the filtered air. The filtration device comprises at least one granular bed. In addition, the filtration device is integrated into the structure of the confined station (for example a wall, or a door support). Filtration by granular bed allows robust and efficient filtration of small particles, and makes it possible to produce a filtration device in different forms which can easily be integrated into a structure of the confined station.This makes the particle capture system space-saving and does not disrupt users' movement on the platform. In addition, the filtration system consists of only simple components, making it economical and low-noise.

[0014] The invention relates to a system for capturing particles from the air within a confined public transport station, said particle capture system comprising means for sucking in the air present within said confined station, a device for filtering the air from said suction means, and means for distributing the filtered air from said filtration device within said confined station. Said filtration device comprises at least one granular bed crossed by the entire air flow of said filtration device, and in that said filtration device is integrated into a structure of said confined station.

[0015] According to one embodiment, said granular bed is located at human height.

[0016] According to one implementation, said filtration device further comprises a magnetic filter, said magnetic filter being arranged upstream of said granular bed in the circulation of the air flow, said magnetic filter being crossed by the entire air flow of said filtration device.

[0017] According to one configuration, said granular bed is arranged on a wall of said confined station.

[0018] Advantageously, said granular bed is flat.

[0019] Advantageously, said granular bed comprises an air inlet on the side of the wall of said confined station and an air outlet on the side opposite the wall of said confined station, said granular bed being crossed substantially horizontally by said air flow.

[0020] Preferably, said suction means are arranged on a floor of a platform of said confined station or on the periphery of said filtration means.

[0021] According to one configuration, said granular bed is arranged in a door support bordering at least one public transport traffic lane of said confined station, or in a vault support of said confined station.

[0022] Advantageously, said granular bed is annular.

[0023] Preferably, said granular bed comprises an air inlet at the center of said door support or said vault support, and an air outlet at the periphery of the base of said door support or said vault support, said granular bed being traversed substantially horizontally by said air flow.

[0024] Advantageously, said suction means are arranged at the top of said door support or said vault support.

[0025] According to one aspect, said suction means comprise a fan, preferably a tangential fan or a centrifugal fan.

[0026] According to one implementation, said granular bed comprises a gravity drain opening and / or a gravity fill opening.

[0027] According to one embodiment option, the granular bed comprises solid particles having a size between 0.5 mm and 5 mm, and a roughness between 1 and 100 μm.

[0028] According to one embodiment, said granular bed has a thickness of between 1.5 and 10 cm, preferably between 2 and 5 cm.

[0029] Other characteristics and advantages of the system according to the invention will appear on reading the following description of non-limiting examples of embodiments, with reference to the appended figures described below. List of figures

[0030] [Fig.l]

[0031] [Fig.l] illustrates a capture system according to a first variant of the first embodiment of the invention in front view.

[0032] [Fig.2]

[0033] [Fig.2] illustrates a sectional view of the capture system according to the first variant of the first embodiment of [Fig.l].

[0034] [Fig.3]

[0035] [Fig.3] illustrates a capture system according to a second variant of the first embodiment of the invention in front view.

[0036] [Fig.4]

[0037] [Fig.4] illustrates a capture system according to a third variant of the second embodiment of the invention in front view.

[0038] [Fig.5]

[0039] [Fig.5] illustrates an underground station with door supports for implementing the second embodiment of the invention.

[0040] [Fig.6]

[0041] [Fig.6] illustrates a first variant of the second embodiment of the invention.

[0042] [Fig.7]

[0043] [Fig.7] is a sectional view of [Fig.6] at the level of the granular bed.

[0044] [Fig. 8]

[0045] [Fig.8] illustrates a second variant of the second embodiment of the invention. Description of the embodiments

[0046] The present invention relates to a device for eliminating at least the particles from a gas flow originating from the air present within a confined public transport station, in particular for rail transport (in particular an underground public transport station). For example, it may be a metro or RER (for “Réseau Express Régional” in Île-de-France) station or any equivalent transport.

[0047] By particles is meant any solid or liquid body with a dimension of less than 100 μm, possibly with a volatile phase (for example of the hydrocarbon type) which can be adsorbed on a solid phase.In a non-limiting manner, the particles according to the invention may correspond to soot particles which are fine particles rich in PAHs (polycyclic aromatic hydrocarbons), but also particles originating from the abrasion of parts such as metal particles from brake pads, rails, particles originating from the abrasion of tires, but also pollens, PMi0 particles, which group together particles with a diameter of less than 10 pm, which cause an alteration of respiratory health, PM2.5 fine particles (particles with a diameter of less than or equal to 2.5 pm, consisting of a mixture of different chemical compounds, emitted mainly during combustion phenomena or formed by chemical reactions from precursor gases present in the atmosphere) which also alter cardiovascular health, or even very fine PMI particles (particles with a diameter of less than or equal to 1 pm), etc.

[0048] The different emission sources will produce polluting particles in different proportions: • Metallic, notably metallic iron and iron oxides (hematite Fe2O3 and magnetite Fe3O4) • Minerals, especially crystalline silica (sand) • Organic: Polycyclic Aromatic Hydrocarbons (PAH), volatile organic compounds (VOC), carbonyl compounds, soot carbon (BC), elemental carbon (EC), organic carbon (OC), nitrogen oxides (NOx) and carbon monoxide (CO).

[0049] More particularly, the elements emitted outdoors or in a semi-confined or confined space such as an underground station mainly belong to the following categories: - Organic matter, - Ionic species, - Elemental carbon, - Iron, - Copper, - Calcium, - Zinc, - Aluminum, - Other metals.

[0050] For the purposes of the invention, the term "polluting particles" therefore means particles with a size between 10 nm and 100 pm, the nature of which belongs to the following categories: - Organic matter, - Crystalline silica, - Ionic species, - Elemental carbon, - Iron, - Copper, - Calcium, - Zinc, - Aluminum, - Other metals.

[0051] The particle capture system according to the invention makes it possible to retain particles of different sizes and natures, in particular micrometric particles (PMI, PM2.5 and PM10) targeted for air quality.

[0052] The particle capture system according to the invention comprises: - Means of suction of the air present within the confined (underground) station, to suck the polluted air from the confined (underground) station, - A filtration device connected to the suction means, to filter the particles contained in the sucked air, and - Means of distributing filtered air from the filtration device, to distribute clean air within the confined (underground) formation.

[0053] In the present application, the term air flow refers to the air circulating in the particle capture system. The air flow may be polluted air, i.e. air loaded with particles, if it is considered before the filtration device, and the air flow may be filtered air (also called treated air or purified air), if it is considered after the filtration device.

[0054] Furthermore, in the present application, the terms “before”, “after”, or “upstream”, “downstream”, or “inlet”, “outlet” are considered in the direction of circulation of the air flow, that is to say from the suction means to the distribution means.

[0055] Further, depending on the relative arrangement of these components, the capture system may include airflow conveying conduits for conveying air from one component to another.

[0056] According to the invention, the filtration device comprises at least one granular bed. The granular bed is formed of solid particles (or grains). To distinguish, in the present application, the particles of the air to be captured, from the particles of the granular bed, the term "particles" or "polluting particles" is associated with the particles of the air to be captured, and the terms "solid particles" and "grains" are associated with the granular bed. The granular bed is configured such that the entire air flow passes through the granular bed. In other words, the air flow is forced into the granular bed. Such a granular bed allows efficient and robust filtration of particles, in particular small particles. In addition, the granular bed allows for low pressure drop, in particular compared to a HEPA filter.In addition, the granular bed allows for adaptation of the shape and size of the filtration device, which facilitates its implementation, especially in confined spaces. In addition, the filtration device only includes simple elements, which makes it economical.

[0057] Furthermore, the filtration device is integrated into a structure of the confined (underground) station. In other words, the filtration device is arranged within a structure of the confined (underground) station. Thus, the capture system does not require the installation of an imposing filter on the platform of the confined (underground) station. The term structure of the confined (underground) station refers to an element that serves the operation or rigidity of the confined (underground) station. This may include, in particular, a wall, a platform door support, a vault support, or any similar element. This specific installation is permitted in particular by the nature of the filtration device (granular bed). If necessary, the structure of the confined (underground) station may be adapted.

[0058] According to one embodiment, the granular bed may be formed of solid particles (or grains) with a size between 0.5 mm and 1 cm, in particular between 0.5 mm and 5 mm, preferably between 0.5 mm and 2 mm, and more preferably between 0.5 mm and 1.8 mm. These value ranges allow effective filtration of the finest particles, for example particles with a size between about ten nanometers and about ten microns. Within the granular bed, the grains may have similar diameters or different diameters. In addition, the granular bed may comprise several layers, each layer comprising a specific grain diameter. For this embodiment, the layers may be arranged in the air flow such that the air flow passes through the layers in decreasing order of grain diameters.

[0059] Advantageously, the grains may have a high surface roughness, i.e. a surface roughness of the grains of between 1 μm and 100 μm. Indeed, these roughnesses promote the attraction of particles, for example particles having a size of between about ten nanometers and about ten micrometers.

[0060] According to one implementation of the invention, the grains may be porous. This porosity may promote the retention of polluting particles in the granular bed and limit its pressure loss. For example, the pore volume defined by the pore volume over the total volume may be between 50 and 70%. Alternatively, the grains may be non-porous.

[0061] According to one implementation, the grains constituting the granular bed may be of mineral, organic, zeolitic or metallic origin. Advantageously, it is possible to use particles of mineral oxides (such as aluminas, silicas, titanium) or products of natural origin resulting from grinding and screening operations (such as sand, natural zeolite, pozzolan, diatoms, etc.) to constitute the granular bed. It is also possible to envisage metallic products such as steel balls, or glass, or even organic products such as polymer resins. The grains may also be catalyst support balls.

[0062] According to one embodiment option, the granular bed may have a thickness of between 1.5 and 10 cm, preferably between 2 and 5 cm. In other words, the air flow passes through the thickness of the granular bed, which has a dimension of between 1.5 and 10 cm, preferably between 2 and 5 cm. Thus, the granular bed is not very thick, thus promoting its integration into a structure of the confined (underground) station. A thicker granular bed may be considered. However, in this case, the pressure losses are greater, and the space requirement becomes greater.

[0063] The granular medium may rest on a support in the form of a grid whose mesh size is smaller than the grain size of the granular bed.

[0064] According to one embodiment, the granular bed can be arranged within the station confined (underground) at man height. This makes it easy to fill and empty the granular bed. This emptying and filling allows the grains to be removed for regeneration of the granular bed, particularly when it is clogged.

[0065] According to one aspect of the invention, the granular bed may comprise a gravity drainage opening, so as to be able to ensure an operation of regeneration of the grains of the granular bed. Preferably, the drainage opening may be located in the lowest portion of the granular bed. Alternatively, the granular bed may comprise a suction drainage opening, so as to be able to ensure an operation of regeneration of the grains of the granular bed.

[0066] According to one aspect of the invention, the granular bed may comprise a gravity filling opening, so as to be able to ensure filling for the first use or after an operation of regeneration of the grains of the gravity bed. Preferably, the filling opening may be located in the highest portion of the granular bed.

[0067] According to one implementation of the invention, the air flow can pass through the thickness of the granular bed. Preferably, the air flow can pass through the thickness of the granular bed in a substantially horizontal direction. In this way, the arrangement of the granular bed is simplified, which facilitates its integration into a structure of the underground formation.

[0068] Preferably, the granular bed may be flat (straight or curved), annular (tubular) or cylindrical. These shapes allow simplified integration into a confined (underground) station structure.

[0069] According to one embodiment of the invention, the filtration device may further comprise a magnetic filter. The magnetic filter makes it possible in particular to filter magnetic ferrous particles, for example those resulting from the wear of brakes or rails. These particles may be larger than the dimensions of the particles filtered by the granular bed. Indeed, agglomerates of magnetic ferrous particles may form. Advantageously, the magnetic filter may be arranged upstream of the particle bed in the direction of the air flow, the filtration device being configured so that the entire air flow passes through the magnetic filter. Thus, the filtration device makes it possible to filter, in a first step, magnetized particles thanks to the magnetic filter (these particles possibly being larger due to agglomeration), and, in a second step, particles thanks to the granular bed.These two filtration methods are complementary to capture air particles within a confined (underground) station. In particular, without the magnetic filter, the particles clog the granular bed more quickly, which requires more frequent regeneration of the granular bed. In addition, even with a magnetic filter, the device of . filtration consists of only simple elements, which makes it economical.

[0070] Advantageously, the magnets can be permanent magnets or electromagnets.

[0071] According to an embodiment option, the magnetic filter may comprise a set of parallel magnets spaced apart from each other. This set of magnets is arranged in a plane perpendicular to the air flow in the filtration device. This set of magnets may be formed, for example, by connected magnetic rods or plates, thus forming a grid. This grid may be mounted in a slide, allowing it to be extracted from the filtration device for cleaning.

[0072] According to an alternative embodiment, the spacing between the magnets can be between 1 mm and 10 mm, preferably between 2 mm and 6 mm. These value ranges allow capture of ferromagnetic particles, without having too significant an impact on the pressure losses.

[0073] Advantageously, the filtration device may comprise a sensor, in particular a pressure drop sensor (for example by pressure difference), to determine the fouling of the granular bed. Thus, it is possible to determine when to carry out regeneration of the granular bed.

[0074] Advantageously, the suction means may comprise sampling means on the one hand and circulation means on the other hand. The sampling means may for example be a grid.

[0075] According to one feature, the air suction means may comprise (where appropriate as circulation means) a fan, a vacuum pump, a suction turbine, or a compressor. For example, the fan may be a tangential fan or a centrifugal fan. The tangential fan has an elongated shape which facilitates its integration into a long, slender volume. The centrifugal fan has a compact shape which facilitates its integration into a restricted volume. The circulation means may be placed between 2 and 5 m from the sampling means to reduce noise within the confined station.

[0076] According to one implementation of the invention, the means for distributing the filtered air may comprise an outlet for the filtered air, for example in the form of a ventilation grille. This outlet for the filtered air may preferably be arranged at a platform of the confined (underground) station. Thus, users of public transport means can breathe filtered air, with a reduced particle rate, in particular a rate of PMI, PM2.5 and PM 10 particles.

[0077] According to a first embodiment, the granular bed can be integrated, by being arranged on a wall of the confined (underground) station. For example, the granular bed can replace an advertising panel within the confined (underground) station. For this first embodiment, the particle bed can be flat, to limit the size of the particle capture system. In other words, the thickness of the granular bed is substantially perpendicular to the wall, the other dimensions of the granular bed are arranged against the wall. Thus, for this first embodiment, the granular bed does not hinder the movement of users on a platform of the confined (underground) station. This first embodiment can be adapted to all confined (underground) stations.

[0078] For this first embodiment, the bed of particles can adapt to the shape of the wall, and can in particular be vertical and / or curved.

[0079] For this first embodiment, the granular bed may comprise an air inlet on the side of the wall of the confined (underground) station, and an air outlet on the side opposite the wall of the confined (underground) station. For this embodiment, the granular bed may be traversed substantially horizontally by the air flow. In other words, the granular bed is traversed from the side of the wall towards the interior of the confined (underground) station.

[0080] According to a variant of this embodiment, the granular bed may have a filling opening at the top of the granular bed, and a drain opening at the bottom of the granular bed. The granular bed, in front view (facing the wall of the confined / underground station) may be substantially rectangular, circular, etc. According to an exemplary embodiment, the granular bed, in front view, may have a substantially hexagonal shape. Thus, the section increases at the top and decreases at the bottom, which may form a hopper at each end to facilitate respectively the filling and draining of the granular bed.

[0081] Advantageously, the distribution means may be located directly on the granular bed, on the side of the granular bed directed towards the confined (underground) station. Thus, no pipe is necessary between the filtration device and the distribution means. Alternatively, the distribution means may be remote, and connected to the filtration device by a pipe.

[0082] According to one example, the passage section of the granular bed may be between 0.3 and 3 m2, preferably between 0.5 and 1 m2. Indeed, these passage sections make it possible to treat at least one air flow of between 2000 and 7500 m3 / h, to treat a significant quantity of air within the confined (underground) station. In addition, the speed of the air flow within the filtration device may be of the order of 5 m / s. According to a non-limiting example, the granular bed may have a height of approximately 1.3 m and a width of approximately 0.5 m and a thickness of 5 cm. The height of 1.3 m also has the advantage of remaining at human height (even if it is slightly raised) to carry out the operations of filling and emptying the granular bed in a simple manner.

[0083] In addition, for this embodiment, the filtration device may further comprise a magnetic filter. The magnetic filter may be arranged upstream of the granular bed. For this purpose, the magnetic filter may comprise a flat box comprising magnets, the box being arranged between the wall and the granular bed. Preferably, the box is not very thick. For this embodiment, the air flow successively passes through the suction means, the magnetic filter box, the granular bed and then the distribution means.

[0084] According to one embodiment of this first embodiment, the suction means may be arranged around the periphery of the plane of the granular bed. For this embodiment, the suction means may comprise at least one tangential fan. For this embodiment, the suction means and the filtration device are located close to each other, which simplifies the capture system.

[0085] Alternatively, the suction means may be arranged on the floor of a platform of the confined (underground) station. For this embodiment, the suction means may comprise at least one centrifugal fan. In addition, a pipe may connect the suction means to the filtration device. This variant makes it possible to move the suction away from the distribution, which makes it possible to prevent the sucked air from coming from the air which has just been filtered.

[0086] A preferred variant of this first embodiment comprises two suction means located on either side of a filtration device. This preferred variant ensures a homogeneous distribution of the air flow in the filtration device, in particular in the granular bed.

[0087] According to a second embodiment, when the confined (underground) station comprises platform doors (automatic doors located at the edge of platforms allowing the safety and fluidity of users in transport), the granular bed can be integrated into the door supports. Such a door support can have substantially the shape of an inverted U with a substantially circular section, the substantially vertical bars of which (called pillars) are arranged at the edge of the platform, and the curvature of the U is above the transport tracks. For example, the granular bed can be placed in the vertical pillars of the inverted U. For this first embodiment, the particle bed can be annular or cylindrical, to limit the size of the particle capture system.Alternatively, when the confined (underground) station does not include doors, it may include a support provided in the vault of the confined (underground) station; such a support may have the shape of an inverted U or a portion of an ellipse. In the remainder of the description, such a support is called a vault support. The second embodiment thus applies to door supports or vault supports. In both cases (door support and vault support), the pillars may be curved or straight.

[0088] Preferably, the granular bed may be integrated into the pillars of the door support or the vault support. This embodiment makes it possible to have the granular bed at height for filling and / or emptying. In addition, this embodiment allows distribution of filtered air at height.

[0089] Preferably, the capture system may comprise two granular beds, for example one in each pillar of the door support or the vault support, thus promoting the distribution of air in the confined (underground) station. In this configuration, the sucked air is divided into two flows directed on either side of the suction means. Alternatively, the capture system may comprise a single granular bed on a single side of the door support or the vault support, which simplifies integration.

[0090] For this second embodiment, for which the granular bed is annular (in other words tubular), the granular bed may comprise an air inlet at the center of the section of the door support or the vault support, and an air outlet at the periphery of the door support, or at the periphery of the vault support. For this embodiment, the granular bed may be traversed substantially horizontally by the air flow.

[0091] For this second embodiment, for which the granular bed is cylindrical, the granular bed may comprise an air inlet on the upper face of the granular bed, and an air outlet on the lower face of the granular bed. For this embodiment, the granular bed may be traversed substantially vertically by the air flow.

[0092] For this implementation, a pipe for transferring the air flow between the suction means and the filtration device can be formed within the door support or the vault support. This implementation allows complete integration of the particle capture system.

[0093] Advantageously, the distribution means may be located directly on the granular bed within the support, and be directed towards the confined (underground) station, preferably towards the platform. Thus, no pipe is necessary between the filtration device and the distribution means. Alternatively, the distribution means may be remote, and connected to the filtration device by a pipe.

[0094] In addition, for this embodiment, the filtration device may further comprise a magnetic filter. The magnetic filter may be arranged upstream of the granular bed. For this purpose, the magnetic filter may comprise a cylindrical box comprising magnets, the box being arranged above the granular bed, for example in the pillars and / or in the arched part (at the top) of the door support or the vault support. For this embodiment, the air flow successively passes through the suction means, the box of the magnetic filter, the granular bed and then the distribution means.

[0095] According to an embodiment of this second embodiment, the suction means can be arranged at the top of the door support or the arch support. In this way, the suction means can capture the most polluted air particles directly above the transport tracks. For this embodiment, the suction means can comprise at least one tangential fan. For this embodiment, the suction means and the filtration device are located nearby, which simplifies the capture system.

[0096] Furthermore, the invention relates to a confined station, for example an underground public transport station, which comprises: - At least one public transport track, - At least one platform, bordering the public transport route, - At least one wall delimiting the confined (underground) station, and - At least one air particle capture system according to any one of variants or combinations of variants described above, for which the granular bed of the filtration device is integrated into the structure of the confined (underground) station.

[0097] The confined (underground) station may also comprise platform doors at the edge of the platform, with at least one door support and / or at least one vault support. In this case, the capture system may be in accordance with the second embodiment of the invention.

[0098] For the second embodiment of the invention, the confined (underground) station may comprise several door supports and / or vault supports equipped with a particle capture system.

[0099] Figures 1 and 2 illustrate, schematically and in a non-limiting manner, a first variant of the first embodiment of the invention. [Fig.l] is a front view, and [Fig.2] is a profile view, which is a sectional view of [Fig.l] along section AA. In these figures, the circulation of the air flow is represented by the gray arrows. The particle capture system 1 comprises two suction means 2, for this embodiment for example a centrifugal fan, two pipes 3, a filtration device 4 and distribution means 9. The pipes 3 connect the suction means 2 to the filtration device 4. The filtration device 4 is fixed to a wall 7 of the underground station. The underground station (partially shown) also includes a platform 10 and a public transport track 11. This embodiment does not disrupt the movement of users on platform 10, because it is fixed to the wall and is not very thick.The filtration device 4 comprises a flat box 8 with magnetized elements to form a magnetic filter. The flat box 8 has a parallelepiped shape. The flat box 8 with the magnetized filter is fixed on the wall 7, and the granular bed 5 is arranged on the flat box 8, and the distribution means 9 are arranged on the granular bed 5. The granular bed 5 has a hexagonal shape with a . filling opening 6 at the top of the granular bed 5, and a drain opening 6' at the bottom of the granular bed 5.

[0100] For this embodiment, the air enters the suction means 2, then into the conduit 3, then into the flat box 8, then into the granular bed 5, and comes out filtered by the distribution means 9. In addition, the regeneration of the granular bed is carried out by emptying the grains from the granular bed 5 through the emptying opening 6', by cleaning the grains, then by filling the granular bed 5 through the filling opening 6.

[0101] This variant illustrates two suction means 2, thus allowing a homogeneous distribution of the air sucked into the filtration device. However, as an alternative, a single suction means may be provided, to reduce the number of components of the particle capture system, or a greater number of suction means may be provided, for example four or six.

[0102] [Fig. 3] illustrates, schematically and in a non-limiting manner, a second variant of the first embodiment of the invention. [Fig. 3] is a front view. The sectional view along the axis AA is identical to the sectional view of [Fig. 2]. The elements identical to the first variant are not re-described. This second variant differs from the first variant by the shape of the flat box 8. For this second variant, the flat box 8 has substantially the shape of an inverted T. This shape limits the surface area of the filtration device on the wall, while ensuring good distribution of the air over the granular bed.

[0103] This variant illustrates two suction means 2, thus allowing a homogeneous distribution of the air sucked into the filtration device. However, as an alternative, a single suction means may be provided, to reduce the number of components of the particle capture system, or a greater number of suction means may be provided, for example four or six.

[0104] [Fig. 4] illustrates, schematically and in a non-limiting manner, a third variant of the first embodiment of the invention. [Fig. 4] is a front view. The sectional view along the axis AA is identical to the sectional view of [Fig. 2]. The elements identical to the first variant are not re-described. This third variant differs from the first variant by the shape and arrangement of the suction means 2. For this variant embodiment, the suction means 2 are arranged on the periphery of the flat box 8. For the illustrated variant, the suction means 2 are arranged to the left and right of the flat box 8. Alternatively or cumulatively, suction means may be arranged on an upper part of the flat box 8 and / or on a lower part of the flat box 8 (these implementations are not shown). They may have an elongated shape, and be tangential fans.For this variant of the first embodiment, no pipe is used between the suction means 2 and the filtration device 4.

[0105] This variant illustrates two suction means 2, thus allowing a homogeneous distribution of the air sucked into the filtration device. However, as an alternative, a single suction means can be provided, to reduce the number of components of the particle capture system.

[0106] [Fig. 5] illustrates, schematically and in a non-limiting manner, an underground public transport station with door supports. The underground station 14 comprises two transport tracks 11 (the number of transport tracks is non-limiting, there may be only one track or a number of tracks greater than two), for the passage of transport vehicles 12 as well as two platforms 10 (the number of platforms is non-limiting, there may be only one platform, in particular if there is only one transport track 11), which are bordered by walls 7. In addition, the underground station 14 comprises platform doors (not shown) at the edge of the platform. These platform doors are supported by door supports 13. The door supports 13 have substantially the shape of an inverted U: with two substantially vertical parts at the edge of the platform and an arched part above the transport tracks 11.

[0107] Figures 6 and 7 illustrate schematically and in a non-limiting manner, a first variant of the second embodiment of the invention. [Fig.6] is a front view, and [Fig.7] is a profile view, which is a sectional view of [Fig.6] along section BB. In these figures, the circulation of the air flow is represented by the gray arrows. The particle capture system comprises a suction means 2, for this embodiment for example a centrifugal fan, two pipes 3, two filtration devices each with a granular bed 5 and distribution means 9. The suction means 2 is located at the top of the door support 13. In addition, it is directed towards the transport routes (not shown) to suck up the most polluted air. The conduits 3 are formed in the door support 13 to connect the suction means 2 to the two granular beds 5. The granular beds 5 have a substantially annular shape.The air to be filtered arrives at the center of the support, crosses radially and substantially horizontally the granular bed 5. The distribution means 9 surrounds the granular bed 5 to distribute the filtered air around the door support 13. According to an embodiment option not shown, the distribution means 9 can be arranged on the door support, only on the platform side. Thus, the filtered air benefits users of public transport, and is not directly sucked in by the suction means.

[0108] For this embodiment, the air circulates in the suction means, then in the pipes 3, then in the granular beds 5, and comes out filtered by the distribution means 9.

[0109] This variant illustrates two granular beds 5, thus allowing a homogeneous distribution of the filtered air in the underground station. However, as an alternative, a single granular bed can be provided, to reduce the number of components of the system of particle capture, or when only one platform borders the transport routes.

[0110] [Fig. 8] illustrates, schematically and in a non-limiting manner, a second variant of the second embodiment of the invention. [Fig. 8] is a front view. The sectional view along the axis BB is identical to the sectional view of [Fig. 7]. The elements identical to the first variant are not re-described. This second variant differs from the first variant by the addition of a magnetic filter 8, here in a cylindrical form and located above the granular bed. The magnetic filter 8 and granular bed 5 assembly forms the filtration device.

[0111] For this embodiment, the air circulates in the suction means, then in the pipes 3, then in the magnetic filter 8, then in the granular beds 5, and comes out filtered by the distribution means 9.

[0112] This variant illustrates two filtration devices, thus allowing a homogeneous distribution of the filtered air in the underground station. However, as an alternative, a filtration device may be provided, to reduce the number of components of the particle capture system, or when only one platform borders the transport tracks.

[0113] As goes without saying, the invention is not limited to the embodiments described above as examples; on the contrary, it encompasses all variant embodiments.

Claims

Claims

1. Confined public transport station comprising a system for capturing particles from the air within said confined station, said particle capture system (1) comprises means for sucking air (2) present within said confined station, a device (4) for filtering the air from said suction means (2), and means for distributing (9) the filtered air from said filtration device within said confined station, characterized in that said filtration device (4) comprises at least one granular bed (5) crossed by the entire air flow of said filtration device (4), and in that said filtration device (4) is integrated into a structure of said confined station.

2. A confined public transport station according to claim 1, wherein said granular bed (5) is located at human height.

3. Confined public transport station according to one of the preceding claims, wherein said filtration device (4) further comprises a magnetic filter (8), said magnetic filter (8) being arranged upstream of said granular bed (5) in the circulation of the air flow, said magnetic filter (8) being crossed by the entire air flow of said filtration device (4).

4. A confined public transport station according to one of the preceding claims, wherein said granular bed (5) is arranged on a wall (7) of said confined station.

5. A confined public transport station according to claim 4, wherein said granular bed (5) is planar.

6. Confined public transport station according to one of claims 4 or 5, wherein said granular bed (5) comprises an air inlet on the side of the wall (7) of said confined station and an air outlet on the side opposite the wall (7) of said confined station, said granular bed (5) being crossed substantially horizontally by said air flow.

7. Confined public transport station according to one of claims 4 to 6, wherein said suction means (2) are arranged on a floor of a platform (10) of said confined station or on the periphery of said filtration means (4).

8. Confined public transport station according to one of claims 1 to 3, in which said granular bed (5) is arranged in a door support (13) bordering at least one traffic lane (11) of transport in common to said confined station, or in a vault support of said confined station.

9. A confined public transport station according to claim 8, wherein said granular bed (5) is annular.

10. Confined public transport station according to claim 9, wherein said granular bed (5) comprises an air inlet at the center of said door support (13) or said vault support, and an air outlet at the periphery of the base of said door support (13) or said vault support, said granular bed (5) being traversed substantially horizontally by said air flow.

11. A confined public transport station according to one of claims 8 to 10, wherein said suction means (2) are arranged at the top of said door support (13) or said vault support.

12. Confined public transport station according to one of the preceding claims, wherein said suction means (2) comprise a fan, preferably a tangential fan or a centrifugal fan.

13. Confined public transport station according to one of the preceding claims, wherein said granular bed (5) comprises a gravity drain opening (6') and / or a gravity fill opening (6).

14. Confined public transport station according to one of the preceding claims, in which the granular bed (5) comprises solid particles having a size between 0.5 mm and 5 mm, and a roughness between 1 and 100 pm.

15. Confined public transport station according to one of the preceding claims, wherein said granular bed (5) has a thickness of between 1.5 and 10 cm, preferably between 2 and 5 cm.

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