Filter unit with wrapped glass fragments and arrangement of such units in a pond water filtration system

Abstract

One or more filter units (4, 104) in a pond filtration system allow for the efficient treatment of water in contact with angular glass fragments (M2, M3), while offering improved handling through the grasping of water-permeable bags (5) that form the housing of the units. The filtration chamber of the system can house the units, within which the filter elements form a bulk mass suitable for the passage of pond water, including the angular glass fragments (M2, M3), the maximum dimension of the glass fragments being less than or equal to 4 mm, preferably less than or equal to 2 mm. A filter arrangement for filling said chamber includes a tiered arrangement of the flexible filter units (4, 104), possibly with annular layers of units when a central pipe (T) for discharging the clean water is provided. Figure for the abstract: Figure 3B

Description

Title of the invention: Filter unit with wrapped glass fragments and arrangement of such units in a pond water filtration system technical field

[0001] The invention relates to the field of water purification. The present disclosure relates more particularly to a filter unit and a filter arrangement usable in a pond filtration system, as well as a method for obtaining a filter unit. Previous technique

[0002] It is known to perform water filtration from a basin such as a swimming pool or water reservoir. For the purposes of this disclosure, the term "swimming pool" is broad. It also includes any type of swimming pool or group of water basins, in particular including installations for whirlpools or jacuzzis, spas, or the like. Such a water reservoir could, for example, be a fountain or ornamental pond.

[0003] Ponds and swimming pools are generally designed with water circulation systems. For circulation, water is drawn in by one or more pumping devices via a surface suction device, known per se, namely a skimmer, and conveyed to a filter of varying efficiency, which may include a sieve and / or filter media. This filter is installed near the pumping device(s). Such a filtration device is designed to filter out large particles of dirt, such as leaves and insects, down to fine particles, such as pollen and skin flakes, from the circulating water. After passing through the filter, the water is generally reintroduced into the swimming pool or equivalent pond via an inlet located below the surface of the pool water.

[0004] The filter generally consists of a housing or casing delimiting a filtration chamber, into which bulk material can be poured. Most often, the bulk material is sand, which the user can obtain in packaged form. Over time, the particles suspended in the water, which are filtered by the filtration device, settle on the filtration surface in the chamber. In practice, sand-based filtration materials lose their effectiveness, which necessitates discarding the used sand and: - either buy new quantities of sand, - or store a substantial stock of sand which represents a significant amount of space.

[0005] More generally, filtering large quantities of pond water that is not protected against external contamination, leaf deposits, or other debris, with a water volume representing several thousand or tens of thousands of liters in most cases, frequently causes fouling or clogging of the filter media (increased pressure inside the filter). In the case of sand or loose media, either large quantities of water must be used to counteract the clogging (backwashing), or the user must remove the filter media from the filtration chamber, a tedious process. Most often, it is not permitted to reuse this clogged loose media once it has been removed from the filtration chamber. Indeed, cleaning with water after removal is not easy, and the operating instructions clearly indicate the need to change the sand.

[0006] Cartridge filters are also known, but their notable drawback is the need for frequent purchase of new cartridges, usually at intervals specified by the manufacturer or even more frequently due to incidents. Ultimately, the maintenance cost is higher. Furthermore, the negative environmental impact of such single-use cartridges, which are discarded and thus become non-recyclable waste, must be emphasized.

[0007] There is therefore a need to minimize the effort required to maintain a water pond filter, while maintaining a high level of water treatment efficiency for the pond (high hygienic performance / prevention of discoloration in the water). The filtration components should be robust, capable of providing a satisfactory level of filtration, and easy to handle during maintenance. Summary

[0008] In order to improve the situation (facilitate maintenance related to a pond filter), a filter unit is proposed, suitable for occupying a filtration chamber, for example by being combined / associated with other filter units to form a filtration layer. More specifically, the filter unit is suitable for filling all or part of a filtration chamber of a pond water filtration system, the filter unit comprising: - a bag (closed bag) which has a wall, permeable to water, allowing an internal volume to be delimited; - filtration elements forming a bulk mass suitable for the water in the basin to pass through; these filtration organs which are maintained in the internal volume comprising or consisting of glass fragments, the glass fragments each having an angular geometry, a maximum dimension of the glass fragments being less than or equal to 4 mm, preferably less than or equal to 2 mm.

[0009] With such a filtering unit, much easier manipulations are permitted for Inserting and removing the bulk of glass fragments from the filtration chamber. Furthermore, a distributed filtration effect is achieved both on the bag's outer layer and on the glass fragments, whose irregular surface area increases the surface area to volume ratio of the filtration elements.

[0010] Thanks to the use of glass fragments, the environmental impact is significantly reduced. Such fragments, which can be obtained from recycling, are compatible with the reuse of filter units through simplified extraction and low-water washing. It is permissible to minimize the consumption of silica sand, which is a resource in great scarcity, on the one hand, and to reduce the quantities of water required for cleaning bulk filtration components.

[0011] The filter unit is compatible with low-carbon production, for example, by reusing glass (recycled glass, for example, from fragments resulting from the implosion of a discarded container). An important quality of glass fragments, regardless of whether they are recycled or not, is their self-sterilizing property, which limits fouling inside each filter unit. The oxides contained in the glass act directly on the catalytic properties of the filtration system. Unlike other filter elements, bulk angular glass fragments can achieve fine filtration while allowing for short, water-efficient backwashes.

[0012] The bag may consist of a rot-proof textile, optionally whose thread elements consist of or are based on a resistant polymer (for example, a semi-crystalline polymer, such as PET or rPET). The bag's thread(s) are mechanically robust and made of a chemically resistant plastic material that does not degrade over time under the action of chemical agents introduced into the water for treatment (such as chlorine, salt, and possibly flocculants). A mesh structure with openings below approximately 0.4 mm may be preferred to prevent any risk of glass fragments escaping.

[0013] Advantageously, a sand filtration system can be compatible with such filter units, which in practice allows the filter media packaged in different bags to be distributed. Several grades can be used in different filter media distributed in bags. The bags may be of similar size and / or have a deformable capacity (to facilitate filling the filtration chamber), by being filled below their maximum capacity.

[0014] The particle size of the glass fragments in the bag can be selected with sufficient fineness for filtration quality, knowing that an assembly of several filter units can allow the filtration chamber to be filled, where appropriate with a variation in particle sizes, typically by interposing a filter layer or pre-filter between the access inlet to the filter chamber and the filter unit(s) of a filtration layer having grade I or grade corresponding to the finest particle size (which does not exceed 1 mm for example).

[0015] In embodiments, the internal volume of the bag is delimited between two opposite faces (possibly two faces distributed across two separate pieces of fabric initially sewn or joined together to delimit the internal volume) of the bag. The bulk mass can extend from one end of the bag to the other, between the two opposite faces. More generally, the bag can have any type of suitable format, with or without the formation of predetermined gusset(s) or folds, as long as the filter unit can vary in its shape and conform to the available space in the filtration chamber.

[0016] In embodiments of the filtering unit, one or more of the following features may be used: - the bag is a textile bag, having a closed configuration which is adapted to allow the filter unit to be mounted in one piece into the filtration chamber, and respectively to be removed in one piece. - the bag is sized to be elongated, between its two opposite ends, so as to have a length greater than the maximum thickness of the filtration unit. - the internal volume can form a first receiving space for glass fragments, optionally supplemented by an additional internal volume delimited in the same filtering unit, for example by the bag or an extension of the bag. - two bag portions of a filter unit, each forming a pocket (internal volume) to receive bulk with glass fragments, can optionally be connected to each other by a junction or link, for example a junction far away / located opposite an end of the initially opened bag portion through which the filling with glass fragments was carried out; this arrangement can minimize handling by reducing the total number of filter units that can fill a filtration chamber while maintaining a relatively flattened conformation of the respective bag portions (which facilitates stacking of the filter units). - at least 95% of the mass of the glass fragments is distributed in glass fragments having a particle size, measured by dry sieving, which is greater than or equal to 0.4 mm. - The glass fragments can have a characteristic size between two limits within the range of 0.5 to 3 mm, for example to allow a filtration fineness of less than 30 microns (possibly on the order of 15 microns) when the filter units are superimposed to fill more than half of a filtration chamber of a housing.

[0017] The filter unit, with small loose glass fragments wrapped in a receiving portion of the bag, thus forms a flexible / relatively flexible partition preventing the mixing of glass fragments packaged in different units, while allowing filter units to be joined together within an arrangement of such units in the pond water filtration system (filtration chamber). The filtration chamber can be delimited by a box or housing having a sand filter-type format.

[0018] When strainers or water re-aspiration sections are provided in a lower part (lower compartment or sub-volume of the filtration chamber), a layer of bulk filter media with a particle size (strictly greater than 1 mm, for example) larger than that of the fragments contained in filtration units located higher up in the filtration chamber may be distributed. The bulk material thus deposited may form a homogeneous layer in which the strainers are embedded / coated, and on which filter units, for example, filter units packed with glass fragments no larger than 1 mm, may rest.

[0019] Depending on one option, the bag capacity (corresponding to the internal volume) can be between 0.75 and 2.5 liters, or possibly more. It is understood that the filter unit is easily handled, for example, graspable with one hand (including in an area substantially in the middle of the bag, between its two ends).

[0020] Regardless of the precise design (specific geometry, capacity) of the bag, it has a closed (definitive or locked) configuration that ensures the filtration elements remain within at least one internal volume. The bag may have a submillimeter mesh size, smaller, for example, at least half the characteristic size of the smallest angular glass fragments contained in the bag. It is understood that a barrier effect is achieved to retain the smallest glass fragments contained in the filter unit. Typically, a filter unit may include fragments whose characteristic size / diameter (equivalent diameter) is on the order of 1 mm (+ / - 0.6 mm). Where appropriate, a filter unit essentially includes submillimeter-sized glass fragments with a lower limit below 0.7 mm. This allows for very fine filtration, preferably without going below 0.4 mm.

[0021] In exemplary embodiments of the filter unit, the glass fragments represent at least 60% by weight, for example, less than 75% by weight, more preferably at least 90% or 95%, of the bulk mass present in the internal volume. Filtration elements of a size similar to or slightly larger than the fragments, flexible or not, hollow / porous or not, resistant to the filtration process in the time, may optionally be provided in certain cases, for example to create an aeration or partitioning effect between the glass fragments. Additionally or as a complement: - the glass constituting the fragments, which is non-porous, can have a density of at least 1.1 or 1.2 g / cm3. - the glass fragments have sharp edges and angles; angular geometry means, in all that follows, that the glass fragments have, as seen under a microscope for example, sharp edges and angles, typically less than 140° (far from a flat angle), for example less than or equal to 120°. They thus have a non-round geometric shape.

[0022] The bag can be designed to be generally flexible. The mesh of the bag is regular in a receiving portion of the bag to receive the glass fragments, in order to maintain a submillimeter mesh size in each contact area between the bag and the glass fragments forming the filtration elements.

[0023] In embodiments of the filtering unit, the following may optionally be used: - the bag has a stitched structure which features: first wire elements which generally extend in a first direction, and which are preferably spaced apart in a second direction distinct from the first direction; and second wire elements which are engaged with a plurality of the first wire elements to form a mesh. - the filter bag is based on a polyester or similar plastic, for example used in plastic bottles or containers put to recycling. - the bag is sewn with thread or threads made from a polymer material, in particular polyester, preferably PET or rPET (recycled). - the bag is made by sewing PET thread(s), for example PET that is at least partly recycled. - the filling of the internal volume by the filtration organs is partial to allow the filter unit to be deformable with an ability to bend, preferably so that the bag can be curved, possibly with a radius of curvature of less than 30 cm. - a textile material of the bag which delimits the internal volume (V5) has a woven, thrown-mesh structure. - the textile material, constituting the bag, can define both the inner surface of the bag and the outer surface. - a textile material of the bag which allows to delimit the interior volume is designed using yarns which have a density (linear mass) ranging for example from 40 Deniers to 65 Deniers. - more specifically, the density for such wire elements (linear mass) can be between 45 and 60 Deniers.

[0024] In some options, it is provided that: - the bag has two longitudinal bands forming the two opposite ends of the bag, at which threads from one side of the bag and threads from a second side of the bag are connected. - the two longitudinal bands, including the filamentous elements / wires, are part of a periphery of the bag which completes / surrounds a receiving portion where the filtration organs are received. - the bag has two margin bands corresponding to longitudinal sewing zones (longitudinal seams) and two opposite ends where transverse seams are formed. - the longitudinal seams or bands and the ends with transverse seams are part of a periphery of the bag which surrounds a receiving part (useful part for delimiting the internal volume) of the filtration organs. - at at least one of the two ends of the bag, a first wall of the bag is connected, for example welded, to a second wall of the bag. - it is planned to close four sides, or three sides when a fold is made to obtain a first side of the bag (three or four joining sides, in the non-limiting option of a substantially rectangular periphery) between the two walls of the bag, so as to prevent any risk of loss of a filtration element. - to form the bag, we start with a sewn piece (in rectangular sheet format) which we fold to overlap the edges and obtain a side delimited by / where there is a folding line of the piece. - by considering the folding line as a bottom side (bottom when the temporary opening is still present, before filling), we understand that the bag has two longitudinal edges which are typically sewn. - a transverse seam is made, opposite a bottom part or folding line, after filling with filter elements in order to close the bag.

[0025] In embodiments limiting the complexity of the filter unit, the bag consists of a single piece, preferably made of a single plastic material. Whether the bag is a sewn piece or assembled by joining different sewn pieces, at least one of the following features may be used: - the filter bag is reusable with its contents. - the filter bag has a permeability with a mesh size greater than 100 or 200 microns, while preferably being submillimetric. - the maximum size of the glass fragments present in each bag is less than or equal to 3 or 4 mm, for example less than or equal to 1.8 mm. - the external surface area of ​​each bag is less than 0.2 m2. - the bag has two sections linked together by a seam or equivalent fastening, the surface of each section having a dimension of approximately 20*45 cm.

[0026] In some embodiments, a welding step (for example, hot welding and / or ultrasonic welding) is carried out after the internal volume has been filled (by inserting the filter elements). In all cases, the bag is provided with a bonded, sealed, or welded band to close a filling opening through which the filter elements have been introduced into the bag, these filter elements having been previously sorted by sieving (where applicable, after a step of obtaining the glass fragments, for example, by implosion using a rotor system to create impacts). In some options, the maximum size difference between the smallest glass fragments and the smallest glass fragments contained in the same filter unit can be less than 0.7 or 0.8 mm.

[0027] The bag can be lightweight, without an additional layer of wrapping. Thus, meshes of the bag can be delimited, in each of the opposite faces of the bag, on the one hand between the first wire elements adjacent in pairs and, on the other hand, between the second wire elements. In independent or complementary embodiment options to the above, the first wire elements are larger (in cross-section) than the secondary filaments.

[0028] After filling the bag with glass fragments / filtering elements, via a (temporarily) open side, the bag can be closed by making a weld parallel to the first direction (direction of the first wire elements), or by making a seam.

[0029] According to one aspect, a filter arrangement is proposed that can be used in a pond water filtration system and is suitable for purifying liquid pond water. This arrangement comprises several filter units as defined above. The arrangement includes a tiered arrangement of the filter units in a filtration chamber of the water filtration system, which allows the contact surfaces formed by the glass fragments to be distributed among the different filter units (within the chamber). A particle size distribution, determined by dry sieving, of the glass fragments present in at least some of the bags of the filter units corresponds to an interval bounded by: - a first submillimeter dimension forming a lower bound of the interval, - and a second dimension, forming an upper bound of the interval, which does not exceed 1 or 2 mm.

[0030] With this arrangement, it is possible to obtain a modular layout, the The conformation can vary depending on the number of filter units arranged against each other, for example, with interface zones between the units distributed in three dimensions. In some options, a stack of annular layers can be achieved, with at least two or three filter units in each annular layer. For at least one layer in such a stack, the lower limit for particle size can be on the order of 0.4 mm. Optionally, for another layer of filter units, for example, one positioned closer to an inlet of the filtration chamber, a further lower limit for the glass fragments can be specified, for example, on the order of 1 mm.

[0031] According to a particular feature, one or more of the filter units define an intermediate filtration layer in which the glass fragments, preferably arranged with the finest grade, allow for greater filtration fineness, compared to / with: - a pre-filter layer formed by at least one other filter unit located closer to an access inlet of the chamber for the introduction of the liquid water to be purified; and - a bulk of glass fragments poured without wrapping into an outlet region, which is preferably at the bottom of the filtration chamber and / or in a region located lower than the intermediate layer in the chamber.

[0032] The filter arrangement makes it much easier to maintain the filtration system, with the added benefit of compatibility with a type of stacking of units which can greatly delay the phenomenon of clogging, for example insofar as the finest grade can be shifted in the filtration chamber, after a pre-filter or a pre-filter layer (for example on the side of the most upstream area in the filter chamber) composed of filter units of a less fine grade.

[0033] Several superimposed filter units can be assembled, while ensuring a high level of filtration fineness, where appropriate with a distribution taking into account the different grades provided in the filter units; a marker, a color and / or a distinction in the shape or geometry of the bags can make it possible to visualize the differences between the filter units, in order to obtain a good compromise between filtration fineness, ease of maintenance and maintenance intervals (much less clogging).

[0034] In some options, a substantially staggered arrangement of the filter units can be implemented in the filtration chamber, including for the pre-filter layer where applicable. More generally, a suitable stacking of filter units containing glass fragments of varying particle sizes (typically from recycling) can be established without risk of glass fragments mixing through the layers of filter units, given the mesh size of the nets or bag (which can also be made of recycled material) forming the outer casing of these units. filtering. During use / treatment, the filter bed is mobilized over a very large specific surface area and depth, preventing the generation of a significant pressure loss over the course of filtration cycles.

[0035] The filter arrangement may include layers of filter units, the lowest of which may be directly superimposed on a bulk of glass fragments of a different grade (for example, a third grade) that is less fine. This bulk material surrounds and is in contact with strainers for similar discharge means to redirect the purified water out of the filtration chamber. This can be practical for avoiding the delicate placement of a bag on the lowest part of the chamber, and considering the bulk / interference caused by the presence of these discharge means, which may be distributed above the bottom of the enclosure delimiting the chamber.

[0036] With this type of filter arrangement, it is possible to retain the primary packaging enveloping the glass, without generating waste - unlike single-use flexible plastic films used to enclose bulk filtration materials such as sand.

[0037] The filter bag may be of the type without openings allowing access to the glass fragments. The filter bag may have an appearance that reveals its contents, consisting of glass fragments, due to the fineness of the bag's wire elements. In some embodiments of the bag, the wire elements constituting the bag may be such as: - the maximum diameter (in section) of a wire element constituting the mesh of the bag can for example be less than 0.5 or 0.6 mm, for example less than 0.3 mm (30 / 100). - Each wire element is free of metallic material. - the bag is free of cotton and / or free of stretchable textile fiber(s).

[0038] According to another aspect, a method is proposed for obtaining a filter unit as defined above, from sorted glass components or containers which preferably result from recycling, the method comprising the steps essentially consisting of: - fragmenting the glass of the components to obtain angular glass fragments, by using a rotor system and / or by means of generating implosion of the components; - to discriminate a portion of the fragments, preferably by sieving, in order to select glass fragments corresponding to a predefined grade; and - pour the selected fragments into the inner volume of a water-permeable bag, as filtering elements, preferably through a single opening (typically a wide opening, formed opposite a bottom zone or line) of said bag, before a step of closing the bag to obtain unity filtering. Brief description of the drawings

[0039] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which: Fig. 1 illustrates an integration, in a basin treatment circuit, of a water purification device according to an embodiment, with a multi-layered arrangement using filtration units each having an envelope in the form of a water-permeable bag. Figure 2A is a detail view of a bag forming the cover of a filtration unit, with fine mesh capable of retaining glass fragments of size 1 mm or less. Figure [Fig. 2B] shows a non-limiting example of mesh, here of the woven cast-iron type, used in the receiving portion of the bag where fragments of glass constituting all or part of the filtration organs are enclosed. Figure 2C illustrates a manual cleaning of each filter unit, which avoids backwashing in a closed room, which is costly in terms of water consumption. Figure 3A is a view of a filter chamber boundary box / enclosure, illustrating internal components of such a box. Figure 3B illustrates, with views similar to that of [Fig.3A], a final filling phase of the filtration chamber, here with filter units arranged in a snail / spiral around or around the periphery of a purified water discharge pipe. Figure 3C shows, by a detail in top view within the filtration chamber during the installation of the filter units, an example of assembly in crowns or rings of filter units, which are further superimposed in layer to form at least two successive layers in the direction of water filtration. Figure 4 schematically shows a detail of a filter unit according to an embodiment of the invention, with a fraction of the filtering elements, including or consisting of glass, visible by transparency. [Fig.5] schematically illustrates an example of equipment for obtaining and sorting glass fragments, typically non-cutting, allowing bags to be filled with a particular grade of glass fragments, before they are closed, for the realization of filter units with packing essentially or exclusively based on glass. [Fig.6] is an enlarged view of contained glass fragments forming the filtering organs of each unit, showing the generally angular character of each of the fragments, with areas of ridges or edges. Description of implementation methods

[0040] The following is a detailed description of several embodiments of the invention accompanied examples and references to drawings. On the different figures, identical references indicate identical or similar elements.

[0041] With reference to [Fig. 1], a water filtration system 1 is illustrated in connection with a basin 2, here filled with liquid water to a sufficient level to allow for a treatment loop. The filtration system 1 may be a filtration unit or assembly comprising a pump P, a filter body / casing 11 delimiting a filtration chamber 10, and suction and discharge piping (return line 6) allowing the circulation of water through filter media (medium contained in the chamber 10) in order to retain suspended solids in the raw water stream to be treated. At least one end El of the piping connects the system 1 to the basin, in order to bring the raw water (to be treated) into the casing 11. The pump P may optionally be interposed between such an inlet El and an inlet E provided on the casing 11.Pump P may include a pre-filter or be associated with a pre-filter to retain large particles that could damage the mechanism of pump P.

[0042] System 1 may be of the type having a selection valve VS, in order to choose whether or not to activate a filtration mode with circulation of raw water from the inlet to an inlet E of the filtration chamber 10. The selection valve VS is located directly on a filter head forming a cover C of the housing 11 or may be coupled to the housing 11 in a different manner. More generally, the filtration system 1 may have a filter arrangement enclosed in a housing 11 provided with an inlet for water to be treated from the basin 2 and an outlet 7 communicating with the basin via a return line 6.

[0043] As shown in Figures 1 and 3B, one or more filter units 4, 104 can fill the filtration chamber 10, allowing the introduction of a filtration medium including angular glass fragments. In particular, each filter unit 4, 104 includes a bag 5 whose wall(s) are permeable to water, allowing the retention of a load of filter elements M2, M3 including or consisting of the angular glass fragments, for example with a specific size range for these fragments in order to act as a filtering medium.

[0044] The glass fragments are enclosed within an internal volume V5 of the bag, which may be the only usable volume delimited by a receiving portion of the bag 5. In alternative embodiments, several internal volumes V5 may be formed within the same wrapping article to constitute a filtering unit (provided that each internal volume is delimited by a water-permeable wall). In addition to an angular geometry, the glass fragments may, for example, have a reduced maximum dimension / size, generally less than or equal to 4 mm, preferably less than or equal to 2 mm, which may be a characteristic particle size corresponding to dry sieving.

[0045] With reference to [Fig. 2C] or 3B, it is understood that the bag 5 can constitute the outer casing, thus defining the external surfaces, of the filter unit 4 or 104, typically with a certain overall flexibility of the bag 5. For example, each filter unit 4, 104 can easily fold and / or flatten, without stretching (or at least locally significant / perceptible stretching) of the wire elements 5f, 5g constituting the bag 5, when the filling level is not close to the maximum filling level. More generally, the bag 5 can be made of textile material, sewn or woven, to allow for greater deformability at a mid-filling level relative to a maximum level.In uses within a housing or box 11 delimiting a filtration chamber 10 several tens of centimeters high, for example with a height greater than or equal to 45 cm, this ability to bend and deform can facilitate stacking filter units 4, 104 one on top of the other. In certain configurations, a 4,104 filter unit, which may have a generally parallelepiped shape, for example during transport phases prior to its use, can be deformed and, if necessary, curved to obtain a radius of curvature of less than 30 cm. This can facilitate a snail-shaped or spiral arrangement of 4,104 filter units, as schematically shown in the non-limiting case of Figures 3B and 3C. Example of a bag design

[0046] With reference to figures 2A, 2B and 2C, the bag 5 can be designed by forming an M5 mesh making it permeable to water while being able to retain glass fragments of angular geometry, for example by limiting the mesh size to the submillimeter range and preferably with the ability to retain glass fragments whose grade goes down to about 0.4 mm (lower limit) of the grade of the glass fragments contained in the bag 5.

[0047] To enable the production of a robust filter unit 4, 104, the bag 5 can be sewn with thread(s) made from a rot-proof polymer material, in particular polyester, preferably PET, which may be recycled PET. Another equivalent polymer may be chosen, i.e., a similar polymer or any polymer constituting a hard, rigid, solid and very chemically stable material under normal water filtration conditions (most commonly water with a temperature between 10 and 37°C).

[0048] The bag 5 can be obtained by joining two walls 51, 52, which are, for example, parts designed separately, or possibly two portions of the same part folded back on itself. More generally, each part used to create the bag 5 is obtained by forming a mesh of wire elements 5f, 5g, so that the bag 5 has a net-like structure. In exemplary embodiments, each bag 5 may have two substantially parallel edges. The bags 5 have, for example, perimeter connections Peripheral connections allowing the definition of a filling aperture 05. Peripheral connections may include: - a bottom connection 5a, opposite the edge 5b, suitable for delimiting the filling opening 05, - and two parallel junctions 5c, forming the two parallel edges of the bag which can define the largest dimension of the bag. A roughly parallelepiped shape of bag 5 can be obtained after filling with filtering organs.

[0049] The bag 5 may have a 2D structure (for example, with at least four coplanar sides before filling), which remains relatively flat so that the maximum thickness Em of a filter unit 4, 104 can be limited to less than 110 mm, for example, less than 80 mm. This facilitates a layered arrangement of the filter units, for example, obtaining at least 4 or 5 superimposed layers for a housing whose filtration chamber height does not exceed 600 or 650 mm. Each bag 5 may have an elongated structure, the thickness Em not exceeding any of the other dimensions of the filter unit 4, 104.

[0050] Before filling, the bag 5 may have a temporary opening 05, delimited by an annular edge in a configuration separated by two opposing walls 51, 52 delimiting the internal volume V5 of the bag 5. The two walls 51, 52 are joined at the parallel junctions 5c and by the bottom joint 5a or fold (intermediate fold between the two walls 51, 52), before filling. After filling, a joint 5d is made to connect two portions of the edge 5b which are respectively distributed in the first wall 51 and in the second wall 52.

[0051] As can be seen in particular in figures 2A and 2B, the mesh M5 makes the walls 51, 52 permeable while limiting the sizes of the multiple lateral openings 3 (openings in the walls 51 52) of the bag: this size is reduced to an order of magnitude close to or equal to that of the diameter of the wire elements 5f, 5g constituting the bag 5. The bulk of glass fragments can be washed efficiently by a jet of water passing through these multiple openings 3.

[0052] As can be seen in particular in Figures 2A, 2B and 4, the bag 5 may have a structure sewn with: - on the one hand, the first wire elements 5f extending along a first direction Dl, while being kept separate from each other along a second direction D2 distinct from the first direction Dl, - and on the other hand, second 5g wire elements which are engaged with a plurality of first 5f wire elements to form the M5 mesh / mesh. More specifically, bag 5 has a woven mesh structure, robust enough to withstand repeated uses (filtration, washing), and compatible with the retention of glass fragments with a particle size grade not exceeding 1.6 or 2 mm for the upper limit, as measured by dry sieving.

[0053] The yarns of the structure of bag 5 can have a density (linear mass) of, for example, between 40 denier and 65 denier. A denier corresponds to the weight in grams of 9000 meters of yarn. Each yarn of bag 5 can, for example, have a density between 45 and 60 denier, being made of a resistant plastic.

[0054] With this type of density, each of the bags 5 of the filter units 4, 104 can exhibit good mechanical resistance during handling or upon impact (e.g., being dropped on the ground), given their weight. More broadly, the robustness of the bags 5 remains compatible with the maneuverability and flexibility to conform to the shape of the housing 11 (particularly the inside of the walls) and allow for regular stacking of each layer of filter units within a filtration chamber 10.

[0055] The plastic threads can, where appropriate, be colored to facilitate identification of the grade of the glass fragments contained in the internal volume(s) V5 of the bag 5. In the filtration chamber 10, each type of bag can then have a particular color (for example Blue and Green), depending on the particle size of the glass fragments: distinct respective grades are then associated with each category of bag 5. When additional media, for example also fragments of glass with angular geometry, or gravel, are to be poured beforehand into the filtration chamber 10 to line the bottom of the box 11, this bulk can be packaged in bags which are not to be kept during filtration, these separate bags therefore being to be untied / opened by the user.

[0056] Such bags (not illustrated) may also have a particular colour to avoid any risk of confusion with the bags 5 of the filter units 4, 104. Whether this packaging option is chosen or not, the bulk of the filter elements Ml may include or consist of particles whose particle size may be in the range of 1.6 mm to 4 mm, with typically 100% of the filter elements Ml being coarser than the filter elements contained in the internal volume of the filter units 4.

[0057] Non-limiting example of obtaining filter units

[0058] In embodiments, the material constituting the bag 5 can be recycled (such as rPET in particular), as can its contents, for example when it consists exclusively of angular glass fragments, preferably obtained after recovery of glass components / containers 30 (see [Fig. 5]) from a collection. An implosion treatment or another similar process is typically used for these glass components / containers 30, which limits / prevents the formation of sharp edges.

[0059] In [Fig. 5], it can be seen that the production of units 4, 104 can be freed from A new glass manufacturing process involves recovering sand from the natural environment, where it is becoming increasingly scarce. Here, each fragment can be obtained from glass components or containers 30 that have already been manufactured and used until they become waste. These are simply sorted containers 30 (resulting from recycling). These containers 30 are, for example, conveyed by a conveyor 41 to a fragmentation station equipped with implosion generation equipment 42.

[0060] After recovering glass components or containers, whether exclusively through recycling or not, the method first comprises: - a fragmentation step 43 for fragmenting or crushing the glass of the components / containers 30, using a rotor system and / or by means 42 for generating implosion of the components 30. This makes it possible to obtain angular glass fragments, typically avoiding direct crushing. In some embodiments, fragments with sharp edges are avoided. Optionally, a rotor speed sufficient to optimize the implosion effect is used, for example, a speed greater than 1200 revolutions per minute as a non-limiting example.

[0061] The method for grouping the suitable glass fragments may then include: - a selection step to discriminate a portion of the fragments, preferably by sieving using a multi-sieve system 44, in order to select glass fragments corresponding to a predefined grade (for example, fragments not exceeding 1.6 mm as the upper limit of the grade); - a pouring / pouring, via opening 05, of fragments resulting from the selection in the internal volume V5 of a water-permeable bag 5 having a mesh size M5 suitable for retaining fine fragments, including submillimeter-sized fragments, which can form the filtration elements; and - a bag closing step 5 to allow obtaining the filter unit 4; 104 ready for use. If necessary, marking or color of threads can be carried out before the glass fragments are poured.

[0062] In order to obtain two categories of filtering units 4, 104 or more, the multi-sieve system 44 can be parameterized to present several diverging paths, guiding the fragments to a final bagging station whose location depends on the type of discrimination carried out upstream (therefore the desired grade, the particle size selected for these fragments).

[0063] Example(s) of installation of filter units in a pond filter

[0064] With reference to [Fig. 1] and Figures 3A-3B, the filter units 4, 104 can to have the ability to deform, like a malleable material, knowing that, for a large majority of filtration elements, which are essentially fragments of glass, the characteristic particle size is less than 1.6 or 2 mm. At least two categories of filter units 4, 104 can be used, including: - a first category of filter units 4 representing the lowest grade or finest particle size, typically in the submillimeter range, which in practice allows reaching the finest level of filtration for example a filtration threshold of less than 10 micrometers; - a second category of filter units 104 representing a less fine grade with comparatively higher particle size, but which can allow a correct level of filtration to be achieved, for example by allowing the separation of particles which may have passed through the M5 mesh of bag 5, typically particles with a size of less than 100 micrometers (the grade of these fragments can for example separate particles of size greater than or equal to 10, 15 or 20 micrometers depending on the case).

[0065] Typically, by comparison with the naked eye, it can be seen that the M2 filtration elements of the 4 units are smaller than the M3 filtration elements of the 104 units, with, for example, the majority or most of the M3 filtration elements consisting of angular glass fragments exceeding one millimeter. In [Fig. 6], it can be seen that the glass fragments have a geometry very different from a round piece or a sphere: they have an angular geometry, which is advantageous for increasing the available surface area in the context of purifying a water flow. The characteristic dimension D4, or particle size diameter (by dry sieving), of the fragments is chosen to be small, in particular less than or equal to 2 mm typically, in order to accumulate a large number (for example, more than 5000 fragments) in each 4, 104 unit.

[0066] In options, with bag size 5 equal (same internal volume V5), the number of glass fragments in units 4 can be at least 3 or 6 times greater than that of units 104. More generally, it is understood that each bag 5 has its own particle size range and that, depending on the space available in the filtration chamber and / or depending on the geometry of the bag, a stacking can be obtained by re-distributing the bags corresponding to a fine particle size in a layer that can serve as a support for a subsequent layer made up of bags corresponding to a less fine particle size.

[0067] In the illustrated case, a lower part of the filtration chamber 10, at the level of which a drain plug BV may be located, is reserved for a packing different from the filter units 4, 104. In the lower space of this chamber 10, not intended to receive the filter units 4, 104, a bulk of first filtration elements Ml (solid elements for mechanical filtration) is arranged to form a coating around water re-aspiration parts (typically strainers 9, as seen in [Fig.3A] before any filling).

[0068] By way of non-limiting example, the first filtration elements M1 are fragments of glass of a higher grade (less fine) than that of the glass fragments of The first category of filter units 4 is optionally larger than that of the glass fragments in the second category. It is understood that these first filtration elements M1 can be poured into the filtration chamber 10 to form a lower filtration layer in the housing 11, which is the layer furthest from the filter inlet E. The inlet E can be located in a filter head or cover C, allowing the upper opening O of the housing 11 to be closed. The upper opening O can be axial, opposite a base S of the housing, or located at least partially on one side.

[0069] The opening O, with circular or annular delimitations, generally has a diameter greater than 90 or 100 mm, much wider than a bottle neck, to facilitate filling operations. Regardless of the precise shape and dimensions of the opening O, each filter unit 4, 104 may optionally have a short side (smaller than a long side of the corresponding bag 5) forming a width that may be less than or equal to the diameter of the opening O, thus facilitating its passage into the chamber 10.

[0070] The filter units 4, 104 may be part of a kit comprising several bags filled with glass fragments, of which one type (where appropriately provided with an opening system facilitating the obtaining of an opening on a predetermined side of the bag) may correspond to the bags to be opened to pour the first filter elements M1, while the other types of bags may be the sewn bags 5, which are to be kept intact for the retention of the glass fragments in the respective internal volume V5 of different filter units 4, 104. It is understood that the different parts of the kit can be put in place in the box 11 of the filtration system 10 when the box 11 is empty or at least sufficiently emptied and cleaned to allow starting again for new cycles of water treatment / purification by filtration through the filter units 4, 104.

[0071] With reference to [Fig. 3A] and 3B, an example is shown of the use of filter units installed in a filtration chamber 10 to achieve a high-performance filtering arrangement. In this case, a pre-filter layer 8p is illustrated as being obtained by installing units 104, whose filtration elements correspond to a less fine grade of filtration than that permitted by the filter units 4 placed further downstream in the direction of flow of the fluid to be purified.

[0072] When a central pipe T is provided in the filtration chamber 10 for the circulation of clean water to the discharge line / pipe 6 via an outlet 7 in the cover C, there is an open upper end of this pipe T which is accessible via the opening O as soon as the cover C is removed. A temporary plug BP (visible in [Fig. 3A]) may optionally be provided to seal such an open end of the pipe T before the chamber 10 is filled.

[0073] A filtering arrangement may selectively use the filter units 4 of the first category, in an intermediate filtration layer 8f, for example placed on the filter elements Ml from the first sachets of the kit (and poured loosely onto the bottom). The filter units 4 are arranged by the user in a spiral pattern, so as to form an annular layer around the pipe T, or more generally in any suitable manner to form a homogeneous, stepped filtration layer based on a medium consisting of angular glass fragments, a good portion of which are submillimeter in size. Here we have illustrated an inlet E located higher than any of the filter units 4, 104 but, alternatively, different arrangements can be adopted, for example if the direction of flow in chamber 10 is not generally vertical and / or if the inlet is positioned differently.

[0074] The user can flatten the bags 5 of the filter units 4 and form two sub-layers or stages in the layer 8f, thus obtaining the finest level of filtration. A comparable arrangement can be achieved by manipulating the bags 5 of the filter units 104, favoring overlap between bags 5, both lengthwise and widthwise. In each layer 8f, 8p of filter units 4, 104 respectively, an inner ring A1 surrounded by an outer ring A2 can be formed, each of these rings A1, A2 being composed of identical / same type filter units, as shown in the non-limiting case of [Fig. 3C]. In some options, geometric / bag size variations can be adopted within the same category of filter units, for example, with one or a few shorter bags to facilitate obtaining the ring shape.

[0075] The filter unit layer 4 is an intermediate layer 8f between the basic layer 8b formed or including the first filter elements Ml arranged loosely, without a casing, and an upper layer 8p with a pre-filter effect allowing to avoid a risk of early clogging in the layer 8f. More generally for a given direction of flow (here generally vertical) of the water to be purified conveyed via the inlet E, the water can first pass through filter units 4 which have been deposited near the inlet E so that a first fraction of particles are separated, according to a given first level of filtration, before passing through the filter units 104 filled with glass fragments of another grade (finer), at the level of the layer 8f which defines the finest level of filtration, finer than the first level.

[0076] With reference to [Fig. 1], the water may come from a basin such as a swimming pool or similar, and the filtering arrangement combining the filter units 4, 104 may be constituted in a filtration chamber 10 of a sand filter (initially designed for operation with sand as the filter media). The use of filter units 4, 104 with glass fragments allows for the benefits of the properties self-sterilization of the glass without risk of degradation of the filtration media and with ease of handling when the filtration system is stopped 1. In operation, the purified water having passed through the filtration arrangement consisting of the filter units 4, 104 can pass through a lower filtration layer consisting of the filtration elements Ml (as seen in [Fig.3B] with the arrows F) and return to the basin 2 (see arrow F' and return line 6).

[0077] It should be obvious to persons versed in the art that the present invention permits embodiments in many other specific forms without departing from the field of application of the invention as claimed. Thus, although the figures show an example of integrating filter units into a box without fixing the bags (which can be placed / stacked), other integrations can be envisaged, for example with the use of guides and / or fixing parts to allow a predetermined or globally determined positioning in the filtration chamber.

[0078] In specific embodiments, one or more filter units may optionally be integrated into a hollow external component such as a cartridge or container with inter-unit fastening means, for example, with a flange or mounting bracket, or other interconnecting elements. This may, where appropriate, improve adaptation to a particular receiving enclosure, further facilitating the efficient installation of the filtration units. In some options, a misalignment system or guidance means, provided or installed in the box 11, allow a first type of filtering unit to be positioned in a suitable sub-zone or compartment of the box, for example on top of a lower compartment filled with bulk glass fragments.

Claims

Demands

1. A filter unit (4; 104) of a water filtration system (1) for a pond (2), suitable for filling all or part of a filtration chamber (10), the filter unit (4; 104) comprising: - a bag (5) having a wall, permeable to water, allowing the delimitation of an internal volume (V5); - filtration elements forming a bulk mass (M2; M3) suitable for being traversed by the water of the pond (2); characterized in that the filtration elements comprise glass fragments and are held in the internal volume (V5) by the bag (5) which is a closed bag defining a filter bag, the glass fragments each having a non-round and angular geometry, a maximum dimension of the glass fragments being less than or equal to 4 mm, preferably less than or equal to 2 mm.

2. Filter unit according to claim 1, wherein the bag (5) is a textile bag, the closed configuration of which is adapted to allow the filter unit (4; 104) to be mounted as a single unit in the filtration chamber (10), and respectively to be removed as a single unit; and wherein at least 95% of the mass of the glass fragments is distributed in glass fragments having a particle size, measured by dry sieving, which is greater than or equal to 0.4 mm.

3. Filter unit according to claim 1 or 2, wherein the glass fragments represent at least 60% by weight of the bulk mass, the glass fragments having sharp edges and angles less than 140°, and wherein the mesh of the bag (5) is submillimetric for a barrier effect retaining the smallest glass fragments contained in the filter unit (4, 104).

4. A filter unit according to any one of the preceding claims, wherein the bag (5) is sewn with thread or threads based on a polymer material, in particular a polyester, preferably PET, and wherein the filling of the internal volume (V5) by the filtering elements is partial to allow the filter unit (4; 104) to be deformable with an ability to bend, preferably so that the bag (5) can be curved with a radius of curvature of less than 30 cm.

5. A filter unit according to any one of the preceding claims, wherein the bag (5) has a sewn structure that has: - first wire elements (5f) extending along a first direction (Dl), and which are preferably spaced apart from each other along a second direction (D2) distinct from the first direction (Dl), and - second wire elements (5g) which are in contact with a plurality of first wire elements (5f) to form a mesh.

6. Filter unit according to any one of the preceding claims, wherein a textile material of the bag (5) which delimits the inner volume (V5) has a woven cast-iron mesh structure.

7. Filter unit according to any of the preceding claims, wherein a textile material of the bag (5) which delimits the inner volume (V5) is designed using yarns which have a density ranging from 40 Denier to 65 Denier.

8. A filter arrangement usable in a pond water filtration system (2), and suitable for purifying liquid water from the pond, the arrangement comprising several filter units (4, 104) as defined according to any one of the preceding claims, wherein the arrangement includes a tiered arrangement of the filter units (4, 104), in a filtration chamber (10) of the water filtration system, allowing the distribution of contact surfaces formed by the glass fragments in the different filter units (4, 104), wherein a particle size, determined by dry sieving, of the glass fragments present in at least a part of the bags (5) of the filter units (4, 104) corresponds to an interval bounded by: - ​​a first submillimetric dimension forming a lower bound of the interval, - and a second dimension, forming an upper bound of the interval, which does not exceed 1 or 2 mm.

9. A filter arrangement according to claim 8, wherein one or more of the filter units (4) define an intermediate filtration layer (8f) in which the glass fragments, preferably of the finest grade in the arrangement, allow for greater filtration fineness compared to: - a pre-filter layer formed by at least one other filter unit (104) located closer to an access inlet (O) of the chamber (10) for the introduction of the liquid water to be purified; and - a bulk of glass fragments poured without wrapping into an outlet region, which is preferably at the bottom of the filtration chamber and / or in a region located lower than the intermediate layer in the room.

10. A method for obtaining a filter unit as defined in any one of claims 1 to 7, from sorted glass components or containers (30) preferably resulting from recycling, the method comprising the steps essentially consisting of: - fragment (43) the glass of the components to obtain angular glass fragments, by using a rotor system and / or by means (42) of generating implosion of the components (30); - to discriminate a portion of the fragments, preferably by sieving, in order to select glass fragments corresponding to a predefined grade; and - pour the fragments from the selection into the inner volume (V5) of a water-permeable bag (5), as filtering elements, preferably through a single opening (05) of said bag, before a step of closing the bag to obtain the filtering unit (4; 104).

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