Filter element and filter comprising at least two filter elements

Abstract

A filter element (10) of a filter has an inner face (20), an outer face, a filter screen (22), two concentric edges, respectively an inner edge (24) and an outer edge (26), the filter screen (22) extending between the inner edge and the outer edge, and main ribs (28) arranged at least on the inner face (20), the main ribs (28) extending substantially radially between the edges (24, 26) and distributed circumferentially to form sectors on the inner face (20), the filter element (10) is configured to be assembled against a corresponding filter element such that the inner face (20) faces an inner face of the corresponding filter element, and the main ribs (28) defining a sector are used to form a compartment in a circumferential direction in a space between the inner face and the corresponding filter element, the inner edge (24) has an inner channel (30) in communication with a corresponding one of the sectors, and wherein at least one rib (28, 40) extending between the edges (24, 26) is a curved rib that is curved over its entire length.

Description

Technical Field

[0001] The present invention relates to a filter element having a filter mesh extending between two concentric edges, a pair of such filter elements arranged against each other and a filter comprising a plurality of such filter elements stacked along an axis. More particularly, the present invention relates to improvements in filter elements. Background Art

[0002] European patent published under number 1091791 describes a filter structure using annular flat filter elements, each filter element having an inner face, an outer face and a filter screen. Figure 1 Describe this filter element. The filter screen is annular and extends between two concentric edges (inner edge and outer edge, respectively). The radial ribs extending on the opposite sides of the filter screen between the concentric edges and axially corresponding to each other along the circumferential direction are used to form sectors on the inner and outer surfaces. This filter element is designed to be assembled against each other in the following manner so that their relative inner faces define a space, which is separated circumferentially by the contact radial ribs of the inner face. For each sector, channels are arranged in the inner edge and the outer edge. By stacking a selected number of filter element pairs, the desired filtration area for the intended application is obtained. Typically, the fluid to be filtered penetrates into the stack through the channel located in the inner edge, passes through the filter screen, and once purified, leaves through the channel defined in the outer edge.

[0003] Furthermore, such filters generally include a backwashing system configured to selectively reverse the flow in some sectors of the filter element in order to clear blockages of the filter mesh in said sectors. However, the alternation between direct flow and reverse flow imposes shear loads on the wires of the filter mesh crossed by the radial ribs: these wires may then break due to fatigue after a certain number of cycles. In particular, this shear load is greatest at each location where the wires of the filter mesh are crossed substantially orthogonally by the ribs of the filter element.

[0004] However, in this known filter element, Figure 1 As indicated in , some radial ribs must extend substantially orthogonally to one of the main directions of the mesh of the filter screen: Figure 1 This is the case at 45°, 135°, 225° and 315° in FIG. Thus, such radial ribs cross a plurality of continuous wires substantially orthogonally along the rib from the inner edge to the outer edge.

[0005] Therefore, this structure may lead to an increasing number of continuous wire breaks over time. Although such breaks do not significantly affect the filtering function of the filter element, they may eventually shorten the service life of the filter element.

[0006] This phenomenon is particularly worrying in newer filter elements which, in addition to the usual radial ribs, also include reinforcing ribs. In fact, in such filter elements, each sector is reinforced by additional ribs extending in radial and / or oblique directions, as disclosed, for example, in the European patent published under the number 3199219. As a result, due to the increase in the number of ribs and the resulting increase in the number of directions taken by these ribs, there is a greater probability that some of these ribs extend substantially orthogonally to the wires of the filter mesh.

[0007] Therefore, there is still room for a new type of filter with improved durability. Summary of the invention

[0008] The present disclosure relates to a filter element, which has an inner face, an outer face, a filter mesh, two concentric edges, namely an inner edge and an outer edge, the filter mesh extending between the inner edge and the outer edge, and at least main ribs arranged on the inner face, the main ribs extending basically radially between the edges and distributed circumferentially to form sectors on the inner face, the filter element is configured to be assembled against a corresponding filter element so that the inner face faces the inner face of the corresponding filter element, and the main ribs defining the sectors are used to form compartments circumferentially in the space between the inner face and the corresponding filter element, the inner edge has an inner channel correspondingly connected to a corresponding sector in the sectors, wherein at least one rib extending between the edges is a curved rib curved over its entire length.

[0009] The concentric edges are generally circular around the central axis, which is hereinafter referred to as the defined axial direction. The main ribs are optionally regularly distributed along the circumference to form sectors on the inner face. The radial direction is a direction perpendicular to the central axis and intersecting the central axis. The axial plane is a plane including the central axis. The radial plane is a plane perpendicular to the central axis. The circumference is a circle included in the radial plane and its center is located on the central axis. The tangential or circumferential direction is a direction tangential to the circumference; it is perpendicular to the central axis but does not intersect with the central axis. As referred to herein, the corresponding filter element can be a filter element substantially similar or identical to the filter element, or a filter element having a non-similar but complementary shape and in particular a filter element having a filter screen extending between the concentric inner edge and the outer edge. Such a corresponding filter element may have a main rib, which is intended to contact the main rib of the inner face of the filter element when the filter element and the corresponding filter element are assembled so as to define a compartment.

[0010] Therefore, the main rib is a rib extending substantially in the radial direction. Specifically, in the present disclosure, the extending direction of any curved rib or more generally any curved portion is defined as the chord direction of the curved rib or more generally the curved portion. In addition, since the outer edge is generally circular around the central axis, the plane in which the outer edge extends is a radial plane.

[0011] Thanks to this filter arrangement comprising at least one curved rib, the tearing phenomenon described above can be prevented or at least reduced. In fact, since the ribs are curved, the number of continuous wires orthogonally crossed by the ribs is necessarily reduced: the area that could be affected by wire breakage is therefore limited. Moreover, and in any case, since the ribs are curved, the warp wires regularly extend from the ribs and mesh with the weft wires that are exposed to the risk of shearing: these warp wires can therefore take on part of the load to which these weft wires are subjected, which prevents the cracks from propagating over long distances.

[0012] Thus, due to the filter arrangement, wire breaks of the filter mesh can be prevented or delayed, or at least these breaks can be restricted to a very limited area, so that the filtering function of the filter element is not significantly impeded.

[0013] In the present disclosure, the curved rib is formed by a single curved portion or a plurality of curved portions connected by an angle point or a single point. Specifically, this means that such a curved rib does not have any straight line segments.

[0014] In some embodiments, each curved portion of such a curved rib locally has a radius of curvature at least 5 times larger, preferably at least 10 times larger, and less than 100 times larger than the pitch between two consecutive wires of the filter mesh.

[0015] In some embodiments, at least some of the main ribs, preferably most of the main ribs or even all of the main ribs are curved ribs. Of course, the more the number of curved ribs, and therefore the fewer the number of straight ribs, the better the tearing phenomenon can be prevented.

[0016] In some embodiments, the main rib comprises a first type of main rib directly connecting the inner edge and the outer edge, and a second type of main rib connecting the inner edge and the outer edge by an eyelet defining an assembly hole. Therefore, it is to be understood that the first type of main rib does not have an eyelet. This assembly hole enables a plurality of filter elements to be stacked by inserting an assembly rod into the assembly hole of each filter element. Therefore, the profile of the eyelet forms the curved portion of the main rib of this second type. In this respect, the profile of this eyelet is preferably circular.

[0017] In some embodiments, at least some of the main ribs of the first type, preferably most of the main ribs of the first type or even all of the main ribs of the first type are curved ribs.

[0018] In some embodiments, the first type of curved main ribs each comprises a single or two curved portions. Preferably, the first type of curved main ribs comprises a single curved portion. A simple profile is indeed preferred to ensure proper waterproofing between sectors.

[0019] In some embodiments, at least two consecutive first-type major ribs are curved ribs, and a concave surface of a first one of the two consecutive first-type major ribs faces a concave surface of a second one of the two consecutive first-type major ribs.

[0020] In some embodiments, at least some of the main ribs of the second type, preferably most of the main ribs of the second type or even all of the main ribs of the second type are curved ribs.

[0021] In some embodiments, the curved main ribs of the second type each comprise an inner link connecting its eyelet to the inner edge, the inner link comprising a single curved portion.

[0022] In some embodiments, the inner connecting rod is substantially tangent to the contour of the eyelet. When the filter element is produced by injection, this configuration makes it easy for the injected material to diffuse toward the eyelet.

[0023] In some embodiments, two consecutive second-type main ribs are curved ribs, and a concave surface of an inner link of a first one of the two consecutive second-type main ribs faces a concave surface of an inner link of a second one of the two consecutive second-type main ribs.

[0024] In some embodiments, the angle formed between the curved main rib and the inner edge is comprised between 60° and 85°, preferably between 75° and 85°. This angle range is a good compromise between the benefits of having a low enough angle to obtain a significant curvature and having a high enough angle to make it easy for the injected material to flow to the rib during manufacturing.

[0025] In some embodiments, the angle formed between the first type of curved main ribs and the outer edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0026] In some embodiments, at least some sectors, preferably most sectors or even all sectors are each provided with at least one reinforcing rib connecting at least one main rib to the edge. Due to these reinforcing ribs, the filter screen surface available for filtration is increased compared to the prior art devices, because the size of the filter element can be increased, and the size of the reinforcing ribs can be smaller than the main ribs and require less material than the main ribs. Due to the increase in the available filter screen surface, the pressure loss is reduced. In addition, this arrangement makes it possible to design a filter element that has a mechanical strength similar to that of a filter element without reinforcing ribs, while being made of a material that is essentially of lower mechanical strength. Specifically, the filter screen itself can have a lower resistance while achieving the expected mechanical strength due to the reinforcing ribs. Preferably, the surface of the reinforcing ribs is recessed relative to the surface of the main ribs: therefore, during the operation of the filter, the influence of the reinforcing ribs on the flow to be filtered is reduced.

[0027] In some embodiments, at least some of the reinforcing ribs, preferably most of the reinforcing ribs or even all of the reinforcing ribs are curved ribs.

[0028] In some embodiments, the reinforcing ribs include a first type of reinforcing rib that is not connected to any second type of main rib, and a second type of reinforcing rib that is connected to at least one second type of main rib.

[0029] In some embodiments, at least one second type of reinforcing rib is connected to the eyelet of the second type of main rib. This is preferably the case for most or even all second type of reinforcing ribs. When the filter element is produced by injection, this configuration makes it easy for the injected material to diffuse toward the eyelet.

[0030] In some embodiments, the two sides of each eyelet are connected in this way by different reinforcing ribs of the second type. Preferably, at least one of these reinforcing ribs converges from the inside toward the eyelet. In fact, the injection of such a filter element is usually carried out from the inside of the filter element toward the outside. Preferably, at least one of these reinforcing ribs is tangent to the profile of the eyelet. This can also make the injection material easy to flow during the injection process.

[0031] In some embodiments, at least one reinforcing rib comprises a plurality of branches, and a plurality of branches are connected to at least three, preferably four elements between two edges and two adjacent main ribs. Due to this configuration, the filter element is better reinforced and the injection material is made to flow more easily during the injection process.

[0032] In some embodiments, the branches of at least one first type of reinforcing rib converge towards the branch connected to the outer edge.Such an orientation reduces the influence of the reinforcing ribs on the flow of the fluid to be filtered during operation of the filter.

[0033] In some embodiments, the branches of at least one second type of reinforcing rib converge towards the connecting rod connected to the inner edge.Such an orientation facilitates the injection material to flow towards the outside of the filter element, and in particular towards the perforations, during the injection process.

[0034] In some embodiments, at least some of the reinforcing ribs have a Psi shape (Ψ), which includes a central link connecting the inner edge and the outer edge, and two converging links, each of which extends from a different main rib and converges toward the outside or the inside to connect the central link, preferably connecting the central link at an offset connection point. However, these connection points can also be common. Preferably, the converging links converge toward the outside. This shape helps to make it easy for the injection material to flow to the outside during the injection process, while reducing the influence of the reinforcing ribs on the flow of the fluid to be filtered during the operation of the filter.

[0035] In some embodiments, at least some of the reinforcing ribs have an Aleph shape. It includes a central connecting rod connecting the inner edge and the outer edge, a divergent connecting rod diverging from the central connecting rod toward the outside to connect the first main rib, and a convergent connecting rod converging from the second main rib toward the outside to connect the central connecting rod. This shape is particularly suitable for making it easy for the injection material to flow to the hole during the injection process, while limiting the influence of the reinforcing rib on the flow of the fluid to be filtered during the operation of the filter.

[0036] In some embodiments, the reinforcing ribs divide the fan-shaped filter surface into regions of substantially similar size. In the present disclosure, regions of substantially similar size are regions that differ from each other by no more than 50%. In those embodiments, the stress in the filter is thus balanced between all regions.

[0037] In some embodiments, the ratio of the filter surface available for filtration to the total filter surface is at least 70%, preferably at least 75%.The special arrangement of the reinforcing ribs enables the ratio of the filter surface available for filtration to the total filter surface to be increased so as to improve the efficiency of the filter element.

[0038] In some embodiments, the angle formed between the curved reinforcement rib and the inner edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0039] In some embodiments, the angle formed between the curved reinforcement rib and the outer edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0040] In some embodiments, at least some of the main ribs, preferably most of the main ribs or even all of the main ribs are connected to the inner edge between two consecutive inner channels.

[0041] In some embodiments, at least some of the reinforcing ribs, preferably most of the reinforcing ribs or even all of the reinforcing ribs are connected to the inner edge at the inner channel.

[0042] In some embodiments, the outer edge includes an outer channel on the outer face. Such a channel enables the filtered fluid to leave the filter element.

[0043] In some embodiments, at least some of the main ribs, preferably most of the main ribs or even all of the main ribs are connected to the outer edge between two consecutive outer channels. This makes it easy for the fluid to be filtered to flow to the outlet channel and thereby reduces the pressure loss during operation of the filter.

[0044] In some embodiments, at least some, preferably most or even all of the reinforcing ribs are connected to the outer edge between two consecutive outer channels. This makes it easy for the fluid to be filtered to flow to the outlet channel and thereby reduces the pressure loss during operation of the filter.

[0045] In some embodiments, the reinforcing ribs extending on both sides of a main rib are connected to the main rib at different positions in the radial direction. Therefore, the stress distribution in the main rib is at different positions. In addition, when two filter elements are assembled against each other, the reinforcing ribs of the corresponding filter elements are at least partially displaced from each other, which leaves more space for fluid flow and reduces the pressure loss of the filter element.

[0046] In some embodiments, the inner edge and / or the outer edge is rounded. However, in other embodiments, although generally round, the inner edge and / or the outer edge has a wavy profile. In practice, when the diameter of the edge is very large, the curvature of the rounded edge may become negligible on a grid scale: such a wavy profile thus increases the curvature of the edge on a local scale without changing the general structure of the filter element on a global scale.

[0047] In some embodiments, the outer edge comprises a groove at least in the contact area where the main rib contacts the outer edge. Such a groove can be arranged on the inner face and / or the outer face. Such a groove makes it possible to limit the accumulation of injection material during injection in parts of the filter element that would be particularly thick if such a groove were not present. In fact, when too much injection material accumulates in a small area during injection, hot spots can occur and delay the cooling of the injection material mass: when these parts finally cool and their surroundings have solidified, shrinkage phenomena will occur, which changes the expected size of the final component. Therefore, such a groove makes it possible to prevent or at least reduce such shrinkage phenomena.

[0048] In some embodiments, the outer edge comprises a notch at least in a first type of contact area in which a first type of main rib contacts the outer edge. Preferably, the notch is arranged in an extension of the first type of main rib. Preferably, the width of the notch is equal to or less than the width of the first type of main rib.

[0049] In some embodiments, the eyelets of at least one second type of main rib, preferably a majority of the eyelets of the second type of main rib or even each of the eyelets of the second type of main rib touch the outer edge.

[0050] In some embodiments, the outer edge comprises an axial recess at least in a second type of contact zone in which the eyelet contacts the outer edge. Preferably, for a given eyelet, the axial recess is provided both on the inner face and on the outer face. Preferably, the width of said axial recess is comprised between 50% and 100% of the inner diameter of the assembly hole.

[0051] In some embodiments, the inner edge includes at least one relief, which is arranged on the outside at the rear of at least one inner channel. The relief may be a protrusion or a groove. Such a relief forms an obstacle that slows down the flow of the injection material during the injection process. This helps to balance the diffusion rate of the injection material on both sides of the filter. In fact, in the case where the injection cavity fills faster on one side of the filter, pressure occurs and pushes the filter to the opposite side, which may change the correct position of the filter in the final component.

[0052] In certain embodiments, the inner edge comprises two concave-convex parts at the rear of each inner channel. Preferably, one of them is a projection, and the other is a groove, the shape of which is complementary to the shape of the projection. Due to this configuration, the projection of the filter element can be received in the groove of the subsequent filter element, thereby forming a maze, improving the tightness of their interface.

[0053] In some embodiments, the filter screen has a conical shape. This reduces pressure losses and enables a stronger connection between the edge and the filter screen near the inner channel. Thus, a larger flow rate can be filtered through the filter.

[0054] In some embodiments, the main ribs also protrude on the outer face so as to form sectors on said outer face.

[0055] In some embodiments, the diameter of the outer edge may be comprised between 100 and 600 millimeters.

[0056] In some embodiments, the main ribs and / or the reinforcing ribs are made of a polymer.However, more conventional materials may of course still be used to make the ribs on the filter element, such as metal, and in particular aluminium.

[0057] In some embodiments, the filter screen is devoid of a support screen.

[0058] The present disclosure also relates to a pair of filter elements according to any of the above embodiments, the filter elements being arranged against each other such that their respective inner faces face each other and contacting main ribs of the respective inner faces divide the space between the inner faces.

[0059] The present disclosure further relates to a filter, comprising a plurality of filter elements according to any one of the above embodiments, wherein the filter elements are stacked along an axis.

[0060] The above-mentioned features and advantages, and others, will become apparent upon reading the following detailed description of exemplary embodiments of illustrated filter elements and filters. The detailed description refers to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The invention and its advantages will be better understood after reading the following detailed description of embodiments of the invention given as non-limiting examples. This description refers to the accompanying drawings, in which:

[0062] - Figure 1 A prior art filter element is shown.

[0063] - Figure 2 shows a perspective view of the inner face of a filter element according to an example;

[0064] - Figure 3 Shows Figure 2 A front view of the inner surface of the filter element;

[0065] - Figure 4 Shows Figure 2 A perspective view of the outside of the filter element;

[0066] - Figure 5 Shows Figure 2 A front view of the outside of the filter element;

[0067] - Figure 6 is a partial perspective view of a filter including two filter elements stacked on each other;

[0068] - Figure 7 yes Figure 3 Magnified view of frame VII.

[0069] - Figure 8 yes Figure 3 Magnified view of frame VIII.

[0070] - Fig. 9 yes Figure 5 A magnified view of frame IX.

[0071] - Fig.10 is an exploded perspective view of a filter element stack;

[0072] - Fig.11 is a perspective view of a filter including a plurality of filter elements. DETAILED DESCRIPTION

[0073] refer to Figures 1 to 6 An embodiment of a filter 100 including a filter element 10 is described.

[0074] according to Figure 2-5The filter element 10 of the embodiment shown in the embodiment has an inner face 20, an outer face 21, a filter screen 22, two concentric circular edges, namely an inner edge 24 and an outer edge 26, and the filter screen 22 extends between the inner edge 24 and the outer edge 26. The concentric circular edges 24, 26 are circles around a central axis X, which is hereinafter referred to as a defined axial direction. The inner edge 24 extends mainly in a plane perpendicular to the axial direction X (i.e., a radial plane). The outer edge 26 extends mainly in a plane perpendicular to the axial direction X (i.e., a radial plane).

[0075] In this embodiment, the diameter of the outer edge 26 is about 260 mm. Of course, other diameters are possible, including, for example, diameters in the range from about 100 mm to about 600 mm.

[0076] The filter element 10 comprises at least one main rib 28 disposed on the inner face 20. Figure 2 , the main ribs 28 are correspondingly arranged on the outer face 21. Thus, if three similar filter elements 10 are stacked, two faces of the filter element in the middle of the stack face the corresponding inner faces of two further filter elements, and the main ribs arranged on these corresponding faces interact to form compartments.

[0077] The main ribs 28 extend in the radial direction between the inner edge 24 and the outer edge 26. The main ribs 28 are regularly distributed along the circumference to form sectors on the inner face 20, such as Figure 1 In this embodiment, the main ribs 28 also form sectors on the outer surface 21, such as Figure 2 is shown in .

[0078] The inner edge 24 has inner channels 30 that communicate with corresponding sectors respectively. The inner channels 30 are provided as recesses or cutouts in the inner edge 24. The inner channels 30 are provided between consecutive main ribs 28. The inner channels 30 are provided on the inner face 20. An abutment portion 31 is left in the inner edge 24 between each inner channel 30.

[0079] like Figure 2 As shown in FIG. 2 , the outer edge 26 has outer channels 32 that communicate with corresponding sectors. The outer channels 32 are provided as recesses or cutouts in the outer edge 26. At least one outer channel 32 is provided between consecutive main ribs 28, and preferably two outer channels 32 in this example. The channels 32 are provided on the outer face 20. An adjacent portion 33 is left in the outer edge 26 between each outer channel 32.

[0080] Some of the main ribs 28 connect the inner edge 24 to the outer edge 26 directly: they are called first type main ribs 28a. Other main ribs 28 connect the inner edge 24 to the outer edge 26 via eyelets 34: they are called second type main ribs 28b.

[0081] These eyelets 34 are circular and define a hole 36 for passing the assembly rod. These eyelets 34 are also configured so as to form male and female bushings for indexing the two filter elements 10 relative to each other.

[0082] In the non-limiting example shown, all the main ribs 28 are curved over their entire length, that is to say, from the inner edge 24 to the outer edge 26 .

[0083] Specifically, in this example, Figure 7 As better shown in FIG. 2 , each main rib 28 a of the first type comprises a single curved portion 51 extending from the inner edge 24 to the outer edge 26 . The curved portion 51 thus deviates from the chord 52 thereof.

[0084] However, of course, other configurations are possible.For example, such a rib may have an S-shape, that is to say may comprise two curved portions joined by an inflection point.

[0085] In the present example, the main ribs 28a of the first type are arranged in pairs, the ribs of a given pair being symmetrical with respect to each other.

[0086] The area where the first type main rib 28a contacts the outer edge 26 is called the first type contact area 29a. Each first type contact area 29a is provided with a notch 71 formed in the outer edge 26 at the junction between the outer surface of the outer edge 26 and its outer surface. The notch 71 is provided in the extension of the rib 28a and has a width substantially equal to the width of the rib 28a.

[0087] As explained above, each second type main rib 28b includes an eyelet 34. More specifically, in each second type main rib 28b, the eyelet 34 contacts the outer edge 26, thus forming a second type of contact area 29b. In addition, each second type main rib 28b includes an inner link 38 connecting the inner edge 24 to the eyelet 34.

[0088] The inner link 38 includes a single curved portion 53 extending from the inner edge 24 to the eyelet 34. The curved portion 53 is thus offset from the chord 54 thereof.

[0089] This profile of the eyelet 34 thus forms a second curved portion 55 connecting the first curved portion 53 to the outer edge 26 , so that the second type of main rib 28 b is also a curved rib in the sense of the present disclosure.

[0090] In the present example, the second type of main ribs 28b are arranged in pairs, the ribs of a given pair being symmetrical with respect to each other.

[0091] Furthermore, in each second type of contact area 29b, two axial recesses 72, 73 are provided, which are provided on the inner face 20 and the outer face 22, respectively. In particular, the axial recess 73 on the outer face 21 is provided in the abutment portion 33 of the outer edge 26. The width of these axial recesses 72, 73 is substantially equal to the inner diameter of the hole 36.

[0092] In the non-limiting example shown, each filter element 10 is divided into twelve sectors and has four eyelets 34, wherein the liner is regularly spaced circumferentially. Therefore, this filter element 10 has eight first type main ribs 28a and four second type main ribs 28b. Especially according to its diameter size, the filter element can have fewer or more sectors. For example, the filter element with an outer diameter of 100 to 150 mm can have 8 to 12 sectors, the filter element with an outer diameter of about 300 mm can have 16 sectors, and the filter element with an outer diameter of 500 to 600 mm can have 20 to 24 sectors.

[0093] The filter element 10 can be manufactured by molding around the filter screen 22. In other words, they can be manufactured by injection molding or similar means, wherein the filter screen 22 forms an insert in the mold. The molded part can be made of metal (e.g., aluminum alloy) or plastic material (especially polymer). The main ribs 28 as well as the inner edge 24 and the outer edge 26 can be coated with an elastomer to avoid leakage between the filter elements 10.

[0094] In addition, if Fig. 9 As depicted above, the outer surface 21 of the inner edge 24 is provided with a concave-convex portion 74 located at the rear of the inner channel 30, and each concave-convex portion 74 extends along the circumferential direction of the inner edge 24. In this example, two identical concave-convex portions are provided at the rear of each inner channel 30, which are grooves 74. However, in another example, the first concave-convex portion may be a groove, and the second concave-convex portion may be a protrusion having a shape complementary to that of the groove.

[0095] During operation of the filter, for example, a fluid to be filtered, such as oil or water, can enter the filter 100 through the inner channel 30 of the inner edge 24 of the filter element 10, pass through the filter mesh 22 to be transferred from the inner face 20 to the outer face 21 (whereby the fluid is filtered), and flow out of the filter element 10 through the outer channel 32 of the outer edge 26. The opposite flow direction is also possible.

[0096] Furthermore, each sector is provided with at least one reinforcing rib 40 connecting at least the main rib 28 to at least the circular edges 24, 26. In the present example, each reinforcing rib 40 comprises a plurality of branches so as to connect two adjacent main ribs 30 and two circular edges 24, 26. Each reinforcing rib 40 is connected to the inner edge 24 substantially in the middle of the inner channel 24 and to the outer edge 26 between two consecutive outer channels 32.

[0097] The reinforcing ribs 40 are correspondingly arranged on both sides of the filter screen 22, that is, both on the inner surface 20 and the outer surface 21. Their axial thickness is less than the axial thickness of the main rib 28, so that the two surfaces of the reinforcing rib 40 are recessed relative to the surface of the main rib 28.

[0098] Some of the reinforcing ribs 40 are connected to at least the second type main ribs 28b: they are called second type reinforcing ribs 40b, 40b'. Other reinforcing ribs 40 not connected to the second type main ribs 28b are called first type reinforcing ribs 40a.

[0099] These reinforcing ribs 40 can have different shapes, but are preferably curved over their entire length: this means that each branch of these reinforcing ribs is curved. The branches can be connected to each other by corner points or by a single point, preferably by a point of inflection.

[0100] In this example, the first type of reinforcing ribs 40a all share the same configuration, having the shape of the letter PsiΨ. Specifically, this rib includes a central link 41 connecting the inner edge 24 and the outer edge 26, and two converging links 42, 43, each extending from a different adjacent main rib 28a in an oblique direction, converging outwards, so as to connect the central link 41 in the outer half of the central link 41. Preferably, the connection point 42a of the first converging link 42 is slightly offset outwards relative to the connection point 43a of the second converging link 43.

[0101] Here, the central link 41 comprises two curved portions connected by an inflection point. Similarly, each converging link 42, 43 comprises two curved portions connected by an inflection point.

[0102] In this case, the second type of reinforcing ribs 40b, 40b' can have two different configurations. One half of them (identified by reference numeral 40b) has a PsiΨ configuration similar to that described above for the first type of reinforcing ribs 40a: thus, they each comprise a central link 41 and two converging links 42, 43. In this case, preferably, the first converging link 42 (which is the link connected to the second type of main rib 28b) is connected to the eyelet 34 of said main rib 28b, preferably tangential to the profile of the eyelet 34.

[0103] The other half of the ribs or the second type of ribs (identified by reference numeral 40b') have an Aleph Specifically, each reinforcing rib 40b' of this structure includes: a central link 44 connecting the inner edge 24 and the outer edge 26; a divergent link 45, which diverges outward from the inner half of the central link 44 to connect the adjacent second type main ribs 28b; and a convergent link 46, which extends from the adjacent first type main ribs 28a and converges outward to connect the central link 41 in the outer half of the central link 41. The divergent link 45 is connected to the eyelet 34 of the second type main rib 28b.

[0104] Here, the central link 44 includes two curved portions connected by an inflection point. As for the divergent link 45 and the convergent link 46, they may include one or two curved portions.

[0105] In this example, each second type main rib 28b is connected to a reinforcing rib 40b of the PsiΨ structure on one side and to an Aleph structure on the other side. The reinforcing ribs 40b' are connected.

[0106] like Figures 2 to 5 As shown in FIG. 1 , the reinforcing ribs 40 divide the filter screen surface into sectors of substantially equal area.

[0107] like Figure 6 As shown in , the filter elements 10 are configured to be assembled against each other so that their respective inner faces 20 face each other so as to define a space between them. The space is separated circumferentially by contacting main ribs 28 of the inner faces. On the other hand, the main ribs 28 arranged on the outer faces 21 do not have to contact each other. Separating sectors on the side of the filter screen 22 where the unfiltered liquid is introduced enables the filter screen 22 to be cleared of blockages by backwashing, as is known in the art.

[0108] The filter 100 is made by assembling at least two filter elements 10 together, such as Figure 6 To obtain a filter with a desired filtering capacity, it is only necessary to stack and assemble the desired number of individual filters 100 together, as shown in FIG. Figure 6 Filters displayed in .

[0109] The reinforcing ribs 40 extending on either side of a main rib 28 are connected to the main rib 28 at different positions in the radial direction. Due to this feature, when two filter elements 10 are assembled against each other so that their corresponding inner faces 20 face each other, the reinforcing ribs 40 of the corresponding filter elements 10 do not fully face each other in the axial direction. In other words, when two filter elements 10 are assembled against each other so that their corresponding inner faces 20 face each other, the reinforcing ribs 40 of the facing sectors of the corresponding filter elements 10 are offset relative to each other on the radial plane. Therefore, the reinforcing ribs of adjacent filter elements can have at least a part that does not overlap axially, which is conducive to the flow of fluid.

[0110] Fig.10 A stack 102 is shown, which comprises a plurality of filter elements 10 stacked along an axis X. The filter elements 10 are assembled in pairs with corresponding identical, similar or complementary filter elements 10, as described above. In each pair, the filter elements 10 are arranged against each other so that their corresponding inner faces 20 face each other and the contacting main ribs 28 of the corresponding inner faces 20 separate the spaces between the inner faces 20.

[0111] The assembly rod 104 is inserted into the hole 36 of the filter element 10 , thereby ensuring the alignment and axial correspondence of the filter element 10 .

[0112] Fig.11 Filter 100 is shown in a perspective view in FIG. Filter 100 comprises a housing 110 and a stack 102 of filter elements is arranged within the housing 110. Thus, filter 100 comprises a plurality of filter elements 10, which are stacked along an axis X.

[0113] The filter 100 includes two inlet portions 112 and two outlet portions 114. The filter 100 may include one or more inlet portions 112, and / or one or more outlet portions 114. In this embodiment, the inlet portions 112 are fluidly connected to the channels 30 of the inner edge 24 of the filter element 10, and the outlet portions 114 are fluidly connected to the channels 32 of the outer edge 26. However, the flow direction within the housing 110 and the stack 102 may be reversed.

[0114] The stack 102 of filter elements is secured to the housing 110 in a conventional manner.

[0115] Although the invention has been described with reference to specific exemplary embodiments, modifications may be made to these examples without departing from the general scope of the invention as defined in the claims. In particular, individual features of the different shown / mentioned embodiments may be combined in additional embodiments. Accordingly, the description and drawings are to be regarded as illustrative rather than restrictive.

Claims

1. A filter element (10) comprising an inner face (20), an outer face (21), a filter screen (22), two concentric edges, namely an inner edge (24) and an outer edge (26), the filter screen (22) extending between the inner edge and the outer edge, and at least main ribs (28) arranged on the inner face (20), the main ribs (28) extending substantially radially between the edges (24, 26) and distributed circumferentially to form sectors on the inner face (20), the filter element (10) being configured to be assembled against a corresponding filter element so that the inner face (20) faces the inner face of the corresponding filter element, and the main ribs (28) defining the sectors are used to form compartments circumferentially in the space between the inner face and the corresponding filter element, the inner edge (24) having inner channels (30) correspondingly communicating with corresponding sectors of the sectors, in, At least one rib (28, 40) extending between the edges (24, 26) is a curved rib that is curved throughout its length.

2. The filter element according to claim 1, wherein At least some of the main ribs (28), preferably most of the main ribs (28) or even all of the main ribs (28) are curved ribs.

3. The filter element according to claim 1 or 2, wherein: The main ribs (28) include a first type of main rib (28a) directly connecting the inner edge and the outer edge, and a second type of main rib (28b) connecting the inner edge and the outer edge (24, 26) through an eyelet (34) defining an assembly hole (36).

4. The filter element according to claim 3, wherein At least some of the first type of main ribs (28a), preferably most of the first type of main ribs (28a) or even all of the first type of main ribs (28a) are curved ribs, and Therein, the first type of curved main ribs (28a) each comprise a single curved portion.

5. The filter element according to claim 3 or 4, wherein: At least some of the second type of main ribs (28b), preferably most of the second type of main ribs (28b) or even all of the second type of main ribs (28b) are curved ribs, wherein the curved main ribs (28b) of the second type each comprise an inner link (38) connecting their eyelets (34) to the inner edge (24), the inner link (38) comprising a single curved portion, and The inner connecting rod (38) is substantially tangent to the contour of the hole (34).

6. The filter element according to any one of claims 1 to 5, wherein At least some of the sectors, preferably most of the sectors or even all of the sectors are each provided with at least one reinforcing rib (40) connecting at least the main rib (28) to the edge (24, 26), and At least some of the reinforcing ribs (40), preferably most of the reinforcing ribs (40) or even all of the reinforcing ribs (40) are curved ribs.

7. The filter element according to claims 3 and 6, wherein The reinforcing ribs (40) include a first type of reinforcing rib (40a) not connected to any second type of main rib (28b), and a second type of reinforcing rib (40b, 40b') connected to at least one second type of main rib (28b), and Therein, at least one second type reinforcing rib (40b, 40b') is connected to the eyelet (34) of the second type main rib (28b).

8. The filter element according to claim 6 or 7, wherein: At least some of the reinforcing ribs (40a, 40b) have a Psi shape (Ψ), which includes a central link (41) connecting the inner and outer edges (24, 26), and two converging links (42, 43), each of which extends from a different main rib (28) and converges toward the outside or the inside to connect the central link (41), preferably connecting the central link (41) at an offset connection point (42a, 43a).

9. The filter element according to any one of claims 6 to 8, wherein At least some of the reinforcing ribs (40b') have an Aleph shape It includes a central link (44) connecting the inner edge and the outer edge (24, 26), a divergent link (45) diverging from the central link (44) toward the outside to connect to the first main rib (28), and a convergent link (46) converging from the second main rib (28) toward the outside to connect to the central link (44).

10. The filter element according to any one of claims 6 to 9, wherein The reinforcing ribs (40) divide the filter screen surface of the sectors into areas of substantially similar size.

11. The filter element according to any one of claims 1 to 10, wherein The outer edge (26) comprises grooves (71, 72, 73) at least in the contact areas (29a, 29b) where the main ribs (28) are in contact with the outer edge (26).

12. The filter element according to any one of claims 1 to 11, whereinThe inner edge (24) comprises at least one relief (74), and the at least one relief (74) is arranged on the outer surface (21) at the rear of at least one inner channel (24).

13. The filter element according to any one of claims 1 to 12, wherein The main rib (28) and / or the reinforcing rib (40) are made of polymer.

14. A pair of filter elements according to any one of claims 1 to 13, arranged against each other with their respective inner faces facing each other and with contacting main ribs (28) of the respective inner faces (20) dividing the space between the inner faces (20).

15. A filter (100) comprising a plurality of filter elements according to any one of claims 1 to 13, the filter elements (10) being stacked along an axis (X).

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