FR3131221A1 - SELF-CLEANING FILTERING DEVICE - Google Patents

Abstract

The invention relates to a filtering device comprising: a main conduit (20) receiving a flow of fluid to be filtered, a first screen-shaped filter (12) comprising a first set of parallel rods (12b), arranged across the main duct, and a second set of rods (12a) held parallel to each other and arranged across and against the rods of the first set, the rods of the second set of rods being movable relative to the rods of the first set of rods, and a drive device (31-33) for moving the rods of the second set of rods between a debris collection chamber (25) and an opposite position on either side of the main conduit to move debris retained by the rods of the first filter towards the collection chamber. Figure for the abstract: Fig. 1

Description

SELF-CLEANING FILTERING DEVICE

The present invention relates to the collection of solid waste floating in bodies of water such as oceans, seas, or entrained in a flow of water, such as a stream, a river, a canal. , or a pipe.

It is known to arrange for this purpose a filter across a flow of water, the filter having the shape of a sieve or a grid formed of parallel bars spaced a distance less than the size of the debris to be collect. However, this solution leads to a progressive, more or less rapid clogging of the filter depending on the density of debris entrained in the water flow. It is therefore necessary to ensure continuous or periodic cleaning of the filter.

Patent FR 2 609 643 describes a filtering device formed of mobile filter panels, articulated two by two, like the links of a chain closed on itself and rotated by a wheel. The filter panels are formed of parallel channels with a hydrodynamic profile. A fixed cleaning device projects water against the current, to expel the debris retained by the filter towards an evacuation gutter. As they rotate, the filter panels successively pass in front of the cleaning device. This results in the filter panels passing through the flow twice, which multiplies the drag due to the presence of the filter in the flow and therefore reduces the filtered flow rate of the flow. In addition, certain debris can pass through the part of the filter panels located upstream, relative to the flow, but be retained by a filter panel located downstream and wrap around a strand forming the mesh of the filter panel when the latter returns to the downstream position. It is then difficult to extract such debris from the filter panel.

Patent EP 0 440 573 describes a filter in the form of a vertical bar grid and a filter cleaning comb. The comb is vertically movable and rotating. The teeth of the comb are deployed between the bars on the way up to clean the filter, rotate at the end of the stroke to eject debris and are retracted on the way down to the base of the bars where they are deployed again for a new cleaning cycle . The use of such a comb-shaped cleaning device implies that the filter has the shape of a parallel bar grid. However, such a filter is likely to allow debris having an elongated shape with a width less than the spacing of the bars and a length greater than this spacing. Such a filter therefore has lower filtering efficiency than a sieve-shaped filter.

It is therefore desirable to provide a sieve filtering device associated with a filter cleaning device. It is also desirable to increase the flow rate of the filter without increasing its surface area or mesh width.

Embodiments relate to a filtering device comprising: a main conduit receiving a flow of fluid to be filtered, and a first filter in the form of a sieve comprising a first set of parallel rods, arranged across the main conduit, and a second set of rods held parallel to each other and arranged across and against the rods of the first set, the rods of the second set of rods being movable relative to the rods of the first set of rods, and a drive device for moving the rods of the second set of rods between a debris collection chamber and an opposite position, on either side of the main conduit, to move debris retained by the first filter towards the collection chamber.

According to one embodiment, the rods of the second set of rods are fixed together in an endless loop stretched between pulleys.

According to one embodiment, the collection chamber is located outside the main conduit, a device for cleaning the rods of the second set of rods being arranged in the collection chamber.

According to one embodiment, the device comprises a plate provided with a comb and movable in the collection chamber between two opposite positions comprising an evacuation position towards a debris evacuation conduit and an opposite position, the plate being held in a deployed position where the comb is introduced between the rods of the second set of rods when the plate is moved towards the evacuation position, and in a cleared position when the plate is moved to the opposite position, the plate being configured to drive towards the debris evacuation conduit carried by the rods of the second set of rods.

According to one embodiment, the plate comprises teeth arranged to slide in a groove formed in each of the rods of the second set of rods.

According to one embodiment, each of the rods of at least part of the rods of the second set of rods comprises hooks arranged along the rod on areas of contact with the rods of the first set of rods, to drive towards the chamber collection, debris wrapped around the rods of the first set of rods, the hooks engaging in a groove formed in the rods of the first set of rods.

According to one embodiment, the device comprises a second filter formed by a third set of parallel rods fixed across the main conduit, and a downstream part relative to the fluid flow, rods of the second set, the rods of the second set being fixed together in an endless loop, the rods of the downstream part of the rods of the second set being in contact with the rods of the third set of rods, to move debris retained by the second filter towards a collection chamber.

According to one embodiment, each of the rods of at least part of the second set of rods comprises hooks arranged along the rod on areas of contact with the rods of the third set of rods, to drive towards the collection chamber , debris wrapped around the rods of the third set of rods.

According to one embodiment the rods of the first set of rods are spaced from each other by a distance greater than or equal to a spacing distance of the rods of the second set of rods, and/or the rods of the third set of rods are spaced from each other by a distance less than the spacing distance of the rods of the second set of rods.

According to one embodiment, the rods of the first set of rods are attached to one end on the collection chamber side via an L shape extending downstream in the direction of flow, in order to allow debris driven by the rods of the first set of rods to be driven towards the collection chamber without being sheared and without blocking the advancement of the rods of the second set of rods, or the rods of the first set of rods are fixed only at one end opposite the collection chamber.

According to one embodiment, the device comprises: a fourth set of parallel rods arranged upstream of the first set of rods, and/or a sieve arranged downstream of the second set of rods, the width of the meshes of the sieve being less than a distance spacing of the rods of the second set of rods or of the rods of the third set of rods.

According to one embodiment, the rods of at least one of the sets of rods have a tapered straight section.

According to one embodiment, the main conduit comprises: an inlet opening receiving the fluid flow, an outlet opening, a downstream section channeling the fluid flow towards the outlet opening, the outlet opening having a surface less than a surface of the inlet opening, the surfaces being considered in a plane perpendicular to a longitudinal axis of the main conduit, and an upstream section channeling the flow of fluid to be filtered having entered the main conduit towards the first and second sets of rods, the main conduit having one or more of the following characteristics: the upstream section presents in a plane passing through the longitudinal axis of the main conduit an internal profile forming with the direction of the flow or the longitudinal axis of the main conduit an angle zero or between 0 and 16°, and/or the downstream section presents in a plane passing through the longitudinal axis of the main conduit a rectilinear or curved internal profile and forming with the direction of the flow an angle of between 0 and 20, and preferably between 4 and 9°, and/or the surface of the outlet opening is adjusted so that the speed of the fluid flow leaving the main conduit is between 80 and 110% of the speed of the fluid around the outlet opening, and/or the area of the outlet opening is between 0.1 and 5 times the total surface area for passage of the fluid through the first and second sets of rods, and/or the section upstream of the conduit has a bulge on its exterior face.

According to one embodiment, the main conduit has a section of circular, elliptical, trapezoidal, triangular, polygonal, square or rectangular shape, or a shape composed of these shapes.

Embodiments may also relate to a filtering system comprising a plurality of filtering devices such as that defined above, attached side by side across a flow of fluid.

According to one embodiment, the filtering devices are arranged in a primary conduit comprising: an inlet opening receiving the fluid flow, an outlet opening, a downstream section channeling the fluid flow towards the outlet opening, outlet opening having a surface less than a surface of the inlet opening, the surfaces being considered in a plane perpendicular to a longitudinal axis of the primary conduit, the primary conduit having one or more of the following characteristics: the upstream section has in a plane passing through the longitudinal axis of the primary conduit an internal profile forming with the direction of the flow or the longitudinal axis of the primary conduit an angle of zero or between 0 and 16°, and/or the downstream section present in a plane passing through the longitudinal axis of the primary conduit a rectilinear or curved internal profile and forming with the direction of the flow an angle between 0 and 20, and preferably between 4 and 9°, and/or the surface of the opening of outlet is adjusted so that the speed of the fluid flow leaving the primary conduit is between 80 and 110% of the speed of the fluid around the outlet opening, and/or the surface of the outlet opening is between 0.1 and 5 times the total surface area for passage of the fluid through the first and second sets of rods, and/or the upstream section of the primary conduit has a bulging on its exterior face.

Examples of embodiments of the invention will be described in the following, on a non-limiting basis in relation to the attached figures, among which:

Figure 1 is a longitudinal sectional view of a filtering device, according to one embodiment, Figures 1A, 1B are sectional views along perpendicular section planes of a part of a filter of the device filtering, according to one embodiment,

Figure 2 is a partial longitudinal sectional view along the section plane AA indicated in Figure 1, of the filtering device according to one embodiment,

Figure 3 is a top view of a tray for cleaning debris present on the second filter, according to one embodiment,

Figure 4 is a partial longitudinal sectional view of the filtering device, along the section plane BB indicated in Figure 1, according to one embodiment, Figures 4A, 4B are sectional views along planes of perpendicular section of a part of a filter cleaning device of the filtering device, according to one embodiment,

Figure 5 is a longitudinal sectional view of a part of a filter of the filtering device, according to one embodiment,

Figures 6, 6A, 6B are front views, and in profile section in two perpendicular directions of a part of a second filter of the filtering device, according to one embodiment,

Figure 7 is a front view of a part of a third filter of the filtering device, according to one embodiment,

Figure 8 is a longitudinal sectional view of a filtering device, according to another embodiment,

Figures 9A, 9B are detailed sectional views along perpendicular section planes of a part of a filter of the filtering device of Figure 8, according to one embodiment,

Figures 10A and 10B are detailed sectional views along perpendicular section planes of a part of a filter of the filtering device presented in Figure 8, according to one embodiment,

Figure 11 is a detailed sectional view of a part of a filter of the filtering device presented in Figure 8, according to another embodiment,

Figures 12A, 12B are detailed sectional views along perpendicular section planes of a part of a filter of the filtering device of Figure 8, according to one embodiment,

Figure 13 is a longitudinal sectional view of a part of a filter of the filtering device of Figure 8, according to one embodiment,

Figures 14, 14A, 14B are front views, and in section in two perpendicular directions of a part of a second filter of the filtering device of Figure 8, according to one embodiment,

Figures 15, 15A, 15B are front views, and in profile section in two perpendicular directions of a part of a third filter of the filtering device of Figure 8, according to one embodiment,

Figure 16 is a front view of a part of a fourth filter of the filtering device of Figure 8, according to one embodiment,

Figure 17 is a perspective view of a filtering device, according to one embodiment,

Figure 18 is a longitudinal sectional view of the filtering device of Figure 16, according to one embodiment,

Figure 19 is a front view of a filtering system, according to one embodiment,

Figure 20 is a profile view of the filtering system of Figure 18, according to one embodiment,

Figure 21 is a profile view of a filtering system, according to another embodiment,

Figures 22 and 22A are front views and in longitudinal section of a filtering system, according to another embodiment,

Figures 23 and 23A are front views and in longitudinal section of a filtering system, according to another embodiment.

Figures 24 and 25 are perspective views and in longitudinal section of a filtering device, according to another embodiment,

Figure 26 is a perspective view of a filtering device, according to another embodiment.

Figures 1 and 2 represent a filtering device 1 according to one embodiment. The device 1 comprises a tubular conduit 20 having an inlet opening 21 and an outlet opening 22, and three successive filters 11, 12, 13, the filter 11 being arranged upstream in front of the inlet opening 21, and the filters 12 and 13 being arranged in the tubular conduit 20 so as to receive the flow of fluid 2 to be filtered. However, it should be noted that one and/or the other of filters 11 and 13 can be omitted.

The second filter 12 comprises fixed parallel rods 12b distributed over an entire internal width of the conduit 20 and movable parallel rods 12a, arranged perpendicular to the fixed rods 12b and against them to form meshes of a sieve. The rods 12a are movable in the axial direction of the fixed rods 12b, in order to drive the debris 3 retained by the rods 12a, 12b towards a debris evacuation chamber 25 3.

The rods 12a are fixed to each other at their two ends by cables 34 rotated around pulleys 31, 32, 33. In the example of Figures 1 and 2, the pulleys comprise on one side of the conduit 20 two pulleys 32, 33 and on the other side of the conduit 20, a larger pulley 31, one of the pulleys being rotated by a motor. Of course, pulley 31 can be replaced by two smaller pulleys to obtain a more compact device.

The chamber 25 can accommodate a plate 35 arranged to move back and forth in a direction parallel to the rods 12a, in order to drive the debris 3 retained and carried by the rods 12a towards an evacuation conduit 26 .

It should be observed that on their return path, the rods 12a have less drag than the filter 12 due to the absence of the rods 12b. Chamber 25 is located outside of fluid flow 2.

The filtering device 1 may also comprise a device for cleaning the filter 11. The cleaning device may for example comprise a comb 15 moving along the rods 11 in a direction in the deployed position where the teeth of the comb are arranged between the rods , and in an opposite direction, in the erased position where the teeth of the comb are arranged parallel to the rods 11. The comb 15 can also be moved in a back and forth movement while being held in the deployed position between the rods 11. The debris carried by the comb 15 can be collected in one or two nets on either side of the conduit or not be collected.

The filtering device 1 may also include a suction device 41 for debris 3' retained by the filter 13, to clean the latter and evacuate the debris sucked towards an evacuation conduit 27. A head of the suction device is mounted movable transversely along rods 42 (for example endless screws). The rods 42 are movable transversely in a direction perpendicular to the rods 42, in order to be able to move the suction head over the entire surface of the filter 13 receiving the flow 2. When stopped, the suction device 41 can be stored outside the conduit 20 so as not to obstruct the passage of the flow of fluid 2.

The filtering device 1 can also include a system of doors 21a, 21b, 21c, 21d to allow the rods 12a to pass through the walls of the conduit 20 in the vicinity of the pulleys 31, 32, 33. Each of the doors 21a-21d can be open under the effect of the movement of a rod 12a and close under the effect of elastic return means.

Figures 1A, 1B represent part of the rods 12a, 12b of the filter 12, according to one embodiment. At least part of the rods 12a comprises, in the contact zones with the fixed rods 12b, one or more hooks 12c which slides in a longitudinal groove 12d formed in the rods 12b when the rods 12a are driven in translation in a direction parallel to the rods 12b. The hook 12c makes it possible to push towards the plate 35 the debris retained by the rods 12b and in particular the elongated debris likely to wind around the rods 12b. The rods 12a may include several hooks 12c distributed along their length. The hooks 12c can be distributed over the rods 12a so that each rod 12b is in contact with at least one hook 12c.

Figure 3 represents the plate 35, according to an exemplary embodiment. The plate 35 is formed by a grid, a comb 39a, 39b being formed at one end of the plate 35. The plate 35 can have meshes of width adapted to entrain the debris retained by the filter 12. In the example of f Figure 3, the comb comprises seven teeth 39a extending between eight adjacent rods 12a of the filter 12 and eight shorter teeth 39b, coming into contact with these eight rods 12a, to evacuate the debris retained by the latter and in particular debris of elongated shape wrapped around them. The plate can form a dihedral so that the teeth 39a, 39b of the comb form an angle of between 30 and 60° relative to the plane of the plate 35 in the direction of the evacuation conduit 26. In this way, the teeth 39b in contact with the rods 12a are inclined towards the latter in the direction of movement of the plate towards the evacuation conduit 26. A part at the end of each of the teeth 39a extending between the rods 12a can extend parallel to the plate 35 .

Figure 4 represents the transverse chamber 25 extending on one side of the conduit 20 near the two pulleys 32, 33, and opening into the evacuation conduit 26. Figure 4 also represents the plate 35 in different positions in the chamber 25. The chamber 25 is open on the side of the rods 12a on the conduit 20. The plate 35 is driven in translation from an extreme position 35a to an extreme position 35b (for example from bottom to top), between the two opposite sides of the chamber 25, while the rods 12a are held momentarily fixed, the plate 35 being held in an deployed position to drive, using the teeth 39a, 39b, debris 3" (figure 4B) retained by the rods 12a towards the evacuation conduit 26. Arriving at the evacuation conduit 26 (in position 35b), the debris retained by the plate 35 is evacuated towards the conduit 26, for example by suction. Then, the plate 35 tilts into a position erased 35c to position itself along a wall of the chamber, where the comb is entirely clear of the rods 12a, then is driven in translation in the other direction (position 35d). During the return translation of the plate 35 in the erased position towards the extreme position 35a, the rods 12a are again driven in translation by the pulleys 31-33 until a new phase of cleaning a certain number of following rods 12a , corresponding to the number of teeth of the comb. Arriving at the lower stop (positions 35d, 35a), the plate 35 tilts in the other direction to return to the deployed position where the comb is placed between the rods 12a, the movement of the rods 12a then being stopped. When the plate 35 deploys, from position 35d to position 35a, the teeth 39a scrape the bottom of the chamber 25, which makes it possible to collect debris which would have entered the chamber 25 under the plate 35. The teeth 39a allow also to recover debris which would have passed between the rods 12a in the chamber 25, due to the fact that the rods 12b stop at the entrance to the chamber 25. The plate 35 can be maintained in position 35c in which it does not interfere not with the hydrodynamics of the system, and all the more so since the chamber 25 is located outside the conduit 20 crossed by the flow of fluid 2.

The rods 12b can be rectilinear and fixed only at their ends opposite the chamber 25. According to another embodiment, the rods 12b are fixed at their two ends for greater strength, the chamber side end 25 of each rod 12b being L-shaped in order to allow the debris carried by the hooks 12c to be carried towards the chamber 25 without being sheared and without blocking the advancement of the rods 12a.

The movement of the plate 35 can be controlled by means of one or more tenons 37 moving in a slide 36 extending along a wall of the chamber 25 in a longitudinal direction of the latter, and of a rod 38 secured to the plate 35 and sliding in lateral slides (not shown) of the chamber 25, the positions of the tenon 37 and the rod 38 being controlled by a mechanism (not shown).

Figures 4A, 4B represent one of the rods 12a and a tooth 39b of the comb formed at one end of the plate 35. During their transit through the chamber 25, each of the rods 12a comes into contact with a respective tooth 39b of the plate 35 , the teeth 39b being inclined towards their end in the direction of the evacuation conduit 26. When the plate 35 is driven towards the evacuation conduit 26, the debris 3" likely to be wound around the rods 12a can thus be entrained by teeth 39b.

Figures 5, 6 and 7 represent in more detail a part of each of the three successive filters 11, 12, 13. Figure 5 represents two rods of the first filter 11, according to one embodiment. Each of the filter rods 11 can be spaced from adjacent filter rods by a distance L11. Each of the rods of the filter 11 may have a hydrodynamic profile, with a rounded leading edge and a tapered trailing edge, to reduce the drag of the first filter.

Figures 6, 6A, 6B represent movable rods 12a, and fixed rods 12b of the second filter 12, according to one embodiment. The movable rods 12a are spaced from each other by a distance W12, and the fixed rods 12b are spaced from each other by a distance L12. The meshes of filter 12 thus have dimensions L12 x W12. In the example of Figures 6, 6A, 6B, the movable rods 12a have a circular profile and the fixed rods 12b a hydrodynamic profile, with a rounded leading edge and a tapered trailing edge, to reduce the drag of the second filtered.

Figure 7 represents the filter 13, according to one embodiment. In the example of Figure 7, the filter 13 is in the form of a square mesh sieve of width L13. The meshes of the filter 13 can be formed by rods of round or profiled section. Of course, any other shape of mesh for the filter 13 may be suitable, such as a honeycomb shape.

According to one embodiment, the rods 12a are arranged vertically in the water flow 2 and are moved in a horizontal direction, while the rods 12b are arranged horizontally. In this way, the rods 12a horizontally drive the debris retained by the filter 12 towards the chamber 25. The rods 11 can be arranged in any direction.

The rod cleaning device 12a comprising the plate 35 movable in a back and forth movement can of course be omitted or replaced by any other suitable device, such as a debris suction device. Cleaning of the rods 12a can also be carried out manually during maintenance operations on the filtering device 1.

According to one embodiment, the ratio between the spacings between the rods or the width of the meshes of each pair of consecutive filters (11, 12), (12, 13) can be between 2.5 and 3.5. In an exemplary embodiment, the spacing between the rods 11 is between 2.5 and 5 cm, the spacing between the rods 12a and between the rods 12b is between 1 and 2 cm, and the width of the filter mesh 13 is between 0.3 and 0.6 cm.

Figure 8 represents a filtering device 10 according to another embodiment. The filtering device 10 differs from the filtering device 1 in that it comprises a fourth filter 14, formed by the rods 12a which pass back into the flow 2 downstream of the filter 12 and fixed rods 14a arranged across the flow 2 perpendicularly to the rods 12a and against and downstream of the latter. The rods 12a and 14a thus form a sieve filter 14. Thus, the filtering device 10 takes advantage of the endless return of the rods 12a to form a fourth filter capable of carrying the retained debris towards a chamber 125 parallel to the chamber 25 and arranged on the other side of the conduit 20, and therefore outside the conduit crossed by the flow of fluid 2. In addition, the filter 13 is replaced by a filter 113 disposed downstream of the rods 14a. The rods 12a can also be replaced by rods 112a with a profiled section, in an oblong shape, the sets of rods 12b, 112a then forming a filter 112.

The cleaning of the rods 112a after their passage over the rods 14a can be ensured by a second plate 135 movable in the chamber 125 to evacuate the debris retained by the filter 14. The plate 135 can have substantially the same shape as the plate 35 and be controlled so as to follow the same movements as the plate 35. The plate 135 in the form of a grid can have meshes of width adapted to entrain the debris retained by the filter 14. The plate 135 can be replaced by another cleaning device, for example a suction device moving back and forth along the rods 112a.

Figure 8 also represents motors 43 intended to move the suction device 41 on the surface of the filter 113.

The filtering device 10 may also include a system of doors 121a, 121b, 121c, 121d to allow the rods 112a to pass through the walls of the conduit 20 in the vicinity of the pulleys 31, 32, 33. Each of the doors 121a-121d can be open under the effect of the movement of a rod 112a and close under the effect of elastic return means. Pulley 31 can also be replaced by two pulleys, such as pulleys 32, 33 to limit the bulk of the filtering device 10.

In the case where the rods 14a are insufficiently rigid to remain pressed against the upstream rods 112a, to resist the pressure of the flow 2, stiffeners can be provided placed downstream of the rods 14a and fixed to them at different points distributed along their length. According to another embodiment, the rods 14a are placed upstream of the rods 112a.

Figures 9A, 9B show in more detail the rods 112a, 12b of the filter 112, according to one embodiment. Some or all of the rods 112a comprise, in areas of contact with the fixed rods 12b, a hook 112c which slides in the longitudinal groove 12d formed in the rods 12b. The hook 112c makes it possible to push towards the plate 35 the elongated debris likely to wind around the rods 12b.

Figures 10A, 10B represent the rods 112a, 14a of the filter 14, according to one embodiment. The rods 112a include, in areas of contact with the fixed rods 14a, a hook 112e for pushing towards the plate 135 the debris 3a of elongated shape capable of winding around the rods 14a. The hook 112e can be replaced by a simple point or a shape which fits the upstream part of the rod 14a.

Figure 11 represents part of the rods 112a, 14a of the filter 14, according to one embodiment. In F igure 11, the hook 112e is replaced by a T-shaped hook 112g, the horizontal part of the T-shaped hook being engaged in a groove 14c of complementary shape formed in the rod 14a. The hooks 112g present on the rods 112a thus make it possible both to carry the debris wound up on the rods 14a and to hold the latter against the rods 112a.

Figures 12A, 12B show in detail the end of a tooth 39b of the plate 135, and a part of rod 112a, according to one embodiment. When the plate 135 moves towards a debris evacuation conduit similar to the conduit 26, the end of the tooth 39b can slide in a groove 112f formed in the rod 112a, in order to be able to drive towards the debris evacuation conduit 3b which could have wrapped around the rods 112a.

Figures 13, 14, 15 and 16 represent in more detail a part of each of the four successive filters 11, 112, 14, 113. Figure 13 represents two rods of the first filter 11 of the filtering device 8, according to one mode of achievement. The rods of filter 11 can be spaced from each other by a distance L21. Each of the rods of the filter 11 may have a hydrodynamic profile, with a rounded leading edge and a tapered trailing edge, to reduce the drag of the first filter.

Figures 14, 14A, 14B represent movable rods 112a, and fixed rods 12b of the second filter 12, according to one embodiment. The movable rods 112a are spaced from each other by a distance W22, and the fixed rods 12b are spaced from each other by a distance L22. The meshes of filter 12 thus have dimensions L22 x W22. In the example of Figures 14, 14A, 14B, the movable rods 112a have a tapered profile symmetrical with respect to a median transverse plane, the rods 112a being placed in the flow 2 in two opposite directions. The fixed rods 12b may have a hydrodynamic profile, with a rounded leading edge and a tapered trailing edge, to reduce the drag of the second filter.

Figures 15, 15A, 15B represent movable rods 112a, and fixed rods 14a of the third filter 14, according to one embodiment. The fixed rods 14a are spaced from each other by a distance L23. The meshes of the filter 14 thus have dimensions L23 x W22. The fixed rods 14a can have a circular or hydrodynamic profile.

Figure 16 represents the filter 113, according to one embodiment. In the example of Figure 16, the filter 113 is in the form of a square mesh sieve of width L24. The meshes of the filter 113 can be formed by rods of round or profiled section. Of course, any other shape of mesh for the filter 13 may be suitable, such as a honeycomb shape.

According to one embodiment, the ratio between the spacing between the rods or the width of the meshes of each pair of consecutive filters (11, 112), (112, 14), (14, 113) can be between 2.5 and 3.5. According to an exemplary embodiment, the spacing L21 between the rods 11 is between 5 and 8 cm, the spacing W22 between the rods 112a is between 1 and 1.5 cm, the spacing L22 between the rods 12b is between between 2.5 and 3 cm, the spacing L23 between the rods 14a is between 0.7 and 1.3 cm, and the width L24 of the meshes of the filter 113 is between 0.3 and 0.6 cm. The sieve filter 14 therefore has narrower mesh than the filter 112. The additional drag induced by the filter 14 is therefore useful.

Figures 17, 18 represent a filtering device 100, according to one embodiment. The filtering device 100 comprises a tubular conduit 120 comprising an inlet opening 121, an upstream section 120a channeling a flow of fluid to be filtered having penetrated through the inlet opening 121 towards the filters 12, 13 (or 112, 14 , 113), and a downstream section 120b channeling a flow of filtered fluid towards an outlet opening 122 of the conduit. The conduit 120 can be arranged to accommodate the filtering device 1 or 10, with the filter 11, formed of parallel rods fixed along two opposite edges of the inlet opening 121. In the example of Figures 17 and 18, the parallel rods forming the filter 11 are curved. The filter 12 (or 112 possibly with the filter 14) can be placed in an upstream section 120a of the conduit, and the filter 13 (or 113) can be placed between the upstream section 120a and the downstream section 120b.

The filtering device 100 can be used while being immersed in a flow of fluid 2, for example towed or pushed under the surface of a body of water, or held fixed under the surface of a watercourse. It can be observed that only the inlet opening 121 of the device can be immersed, the longitudinal axis X of the device 100 being maintained at an angle less than 25° relative to the surface 1 of the water.

According to one embodiment illustrated by F igure 18, the upstream section 120a delimits an internal volume of tubular shape having a straight section, for example of rectangular shape and of constant surface area between the inlet opening 120 and the inlet of the filter 13 or 113. Thus the total surface of each of the filters 12, 13 (or 112, 113 and possibly 14) can be identical to the surface of the inlet opening 121. The downstream section 120b delimits an internal volume of the shape frustoconical with an internal section, for example of rectangular shape, narrowing from the outlet of the filter 13 or 113 to the outlet opening 122. The internal volume of the downstream section can have other shapes such as that of a hyperboloid of revolution .

The exterior surface of the conduit 120 may have, around the inlet opening 121, a convex profile widening from the inlet opening 121. At the junction of the upstream sections 120a and downstream 120b, the profiles of the latter present the same tangent outside the conduit. It can be observed that such a profile generates a drag opposite the direction of flow 2, that is to say favoring the movement of the device in the flow. In the example of Figure 18, this convex profile widens to approximately half the length of the upstream section 120a, then narrows to the outlet opening 122 . According to one embodiment, the ratio between the length of the interior profile and the length of the exterior profile of the upstream section 120a is between 0.7 and 1.0. The bulging thus produced increases the length of the path traveled by the fluid and therefore increases the speed of the latter around the upstream section 120a. This results in a reduction in pressure around the upstream section 120a, which creates positive drag. We thus obtain better hydrodynamic performance of the tubular conduit 120, whatever the speed of the fluid in and around the conduit.

According to one embodiment, the upstream section 120a presents in a plane passing through the longitudinal axis preferably between 0 and 4°. These characteristics help to reduce drag acting in the direction of flow 2.

According to one embodiment, the downstream section 120b presents in a plane passing through the longitudinal axis between 4 and 9°.

According to one embodiment, the downstream section 120b comprises a section 120c whose downstream end delimits the outlet opening 122. The size of the internal section of the section 120c is such that the edge of the opening 122 is tapered, so as to to avoid the possible separation of the fluid from the external wall of the conduit 120 in this zone.

According to one embodiment, the surface of the outlet opening 122 is defined so that the speed of the fluid leaving the conduit 120 is between 80 and 110%, and preferably equal to 100% of the speed of the fluid around the outlet opening 122. In this way, the shear appearing at the interface between the fluid leaving through the outlet opening 122 and the fluid outside the conduit is reduced, which makes it possible to reduce the drag s exerting on the conduit 120. The surface of the outlet opening 122 can be adjusted by varying the length of the downstream section 120b and the angle α. Furthermore, the speed of the flow in the conduit depends on the characteristics of the filters 11, 12, 13 (or 11, 112, 14 and 113), and in particular on the drag coefficients of these filters. The lower these coefficients are, the more the length of the downstream conduit 120b can be reduced, which also reduces the overall drag of the conduit 120. Furthermore, the lower the drag coefficients of the filters, the more the speed of the fluid in the conduit can be reduced. be high. Thus, the outlet opening 121 can be widened.

According to one embodiment, the cleaning devices are stored stationary in the thickness of the wall 120, so as not to obstruct the passage of the flow of fluid 2.

Figures 19, 20 represent a filtering system 200 installed in a watercourse. The filtering system comprises a set of several filtering devices 1 or 10 arranged side by side in a checkerboard pattern attached to posts 218 anchored in the bed of the watercourse. All of the filtering devices can be fixed to the posts 218 in a sliding manner in order to be able to remain at the same distance from the surface of the watercourse thanks to floats 219. A maintenance walkway 216 secured to the set of devices filter 10, and equipped with a guardrail 217, can be provided for access from above to the filtering devices 10. For this purpose, the filtering devices 1, 10 can be mounted in respective slides 116 in order to be able to be extracted from the water for maintenance purposes. Figures 19, 20 show a filtering device in the maintenance position 10’ above the surface of the watercourse. An electromechanical device can ensure the movement of each of the filtering devices 10 between their functional position in the watercourse and their maintenance position 10'.

The filtering system 200 may also include a first filter, for example formed by the set of parallel rods 11 arranged upstream of the set of filter devices 10, the set of parallel rods 11 being associated with the cleaning device 15.

It can be observed that the filtering devices 10 can be arranged in the same plane and be raised above the surface of the watercourse for maintenance, by a translation movement in the direction of the flow 2, then by a movement upward translation between slides.

Figure 21 represents a filtering system 201 which differs from the system 200, in that it is entirely floating and secured to a fixed point 230 upstream of the system 201.

Figures 22, 22A, 23, 23A represent filtering systems 101, 102, 103, 104, according to other embodiments. In the filtering systems 101-104, several filtering devices 1 or 10 are arranged side by side in a conduit such as the conduit 120 (figures 17, 18) having an inlet opening 121 with the dimensions of the inlet openings filtering devices 1, 10 arranged side by side. Filter systems 101-104 can be attached to the bottom of a watercourse on 50 feet.

In the example of Figures 22, 22A, three filtering devices 1, 10 are arranged horizontally in the system 101. In the example of Figures 23, 23A, two or three filtering devices 1, 10 are arranged vertically in the filtering systems 102, 103, 104.

It will be clear to those skilled in the art that the present invention is capable of various embodiments and various applications. In particular, the invention is not limited to a filtering device comprising the first filter 11 and the last filter 13, 113, only the second filter 12a, 12b being able to suffice to retain debris entrained by the flow of fluid 2.

It should also be observed that the second set of rods 12a, 112a can be moved in various other ways and do not necessarily form an endless loop. Thus, Figures 24 and 25 represent a filtering device 50 according to another embodiment. The filtering device 50 comprises a conduit 60, and a filter 52 arranged across the conduit 60. The filter 52 is formed of a set of fixed parallel rods 52b, and a set of movable rods 52a, perpendicular to the rods 52b, fixed between them at their ends and held against the rods 12b, for example upstream of the latter. The rods 52a are movable in translation in the direction of the rods 52b, back and forth, between two chambers 75, 75' on either side of the conduit 60, where they can be cleaned, for example by trays 85 , 85' which can have the same structure as the plate 35 and act in the same way as the latter to clean the rods 52a. The chambers 75, 75' can have the width and height of the conduit 60 at the level of the filter 52 (F igure 24), or else be of smaller width, for example by winding the rods 52a around drums 72, 72' ( Figure 25). Thus, the rods 52a have a length that can correspond to the height of the conduit 60, and all of the rods 52a have a width that can correspond to twice the width of the conduit 60. The rods 52b can have an L shape at their ends. , the rods 52b being fixed together at the end of the L-shaped shapes, in order to allow the debris driven by the rods 52a to be driven towards the collection chamber 75, 75' without being sheared and without blocking the advancement of the rods 52a towards the collection chambers 75, 75'. The rods 52a may be identical to the rods 12a or 112a.

In addition, each of the two sets of rods forming a filter can be movable in the direction of the rods of the other set of rods. Thus, Figure 26 represents a filtering device 50' comprising a filter 52', according to another embodiment. The filter 52' differs from the filter 52 in that the set of rods 52b is also movable in translation in the direction of the rods 52a, back and forth, between two chambers 76, 76' on either side of the conduit 60, where they can be cleaned, for example by trays in the shape of trays 85, 85'. The chambers 76, 76' can also have the width and height of the conduit 60 at the level of the filter 52, or else be of smaller width, for example by winding the rods 52b around drums, the axis of the rods being parallel to that of the drums. Thus, the rods 52b have a length that can correspond to the width of the conduit 60, and all of the rods 52b have a height that can correspond to twice the height of the conduit 60.

The filter 13, 113 can also be movable back and forth so that it can be cleaned on each side of the conduit, for example by suction devices 41' (F igure 25) arranged on each side of the conduit. The filter 13, 113 can thus have twice the width of the conduit and be flexible so that it can be wound on drums 72'. The filter 113 may include an element such as a strip 113a, for example arranged in the middle position of the filter, to drive the debris towards the suction devices 41'.

In the filter 12, 112, the edge of the movable rods 12a, 112a on the side of the fixed rods 12b is not necessarily rectilinear, but may include notches in which the rods 12b slide. This arrangement can also be implemented in filter 14 or 52.

Furthermore, in the filter 12, 112, 52, the rods 12b, 52b can be provided sufficiently rigid to be able to be fixed only at one of their ends.

Furthermore, the internal section of the conduit 20, 120 can be of any shape, for example circular, elliptical, square, rectangular, trapezoidal, triangular, polygonal or a shape combining these shapes.

It is also not necessary for the rods 12a, 12b forming the filter 12 (or 112, 14, 52) to be perpendicular, the meshes of the filter 12 (or 14, 112, 52) being able to be in the shape of a parallelogram.

Claims (16)

Filtering device comprising:
a main conduit (20, 60) receiving a flow of fluid to be filtered, and
a first filter (12, 112, 52) in the form of a sieve comprising a first set of parallel rods (12b, 52b), arranged across the main conduit, and a second set of rods (12a, 112a, 52a) held parallel between they are arranged across and against the rods of the first set, the rods of the second set of rods being movable relative to the rods of the first set of rods, and
a drive device (31-33, 72, 72') for moving the rods of the second set of rods between a debris collection chamber (25, 125, 75) and an opposite position (75'), on either side other side of the main conduit, in order to move debris retained by the first filter towards the collection chamber. Device according to claim 1, in which the rods (12a, 112a) of the second set of rods are fixed together in an endless loop stretched between pulleys (31-33). Device according to claim 1 or 2, in which the collection chamber (25, 125, 75) is located outside the main conduit (20, 60), a device for cleaning (35, 135) the rods of the second set of rods 12a, 112a, 52a) being arranged in the collection chamber. Device according to one of claims 1 to 3, comprising a plate (35, 135, 85, 85') provided with a comb (39a, 39b) and movable in the collection chamber between two opposite positions comprising a position of evacuation (35b) to a debris evacuation conduit (26) and an opposite position (35a), the plate being held in an extended position where the comb is inserted between the rods (12a, 112a, 52a) of the second set of rods when the plate is moved towards the evacuation position, and in a cleared position when the plate is moved to the opposite position, the plate being configured to drive towards the evacuation conduit debris carried by the rods of the second set of stems. Device according to claim 4, in which the plate (35, 135, 85, 85') comprises teeth (39b) arranged to slide in a groove (112f) formed in each of the rods (112a) of the second set of rods. Device according to one of claims 1 to 5, in which each of the rods of at least part of the rods (12a, 112a) of the second set of rods comprises hooks (12c, 112c) arranged along the rod on zones of contact with the rods (12b) of the first set of rods, to drive towards the collection chamber (25), debris wound around the rods of the first set of rods, the hooks engaging in a groove (12d, 112d ) formed in the rods of the first set of rods. Device according to one of claims 1 to 6, comprising a second filter formed by a third set of parallel rods (14a) fixed across the main conduit (20), and a downstream part relative to the fluid flow, rods ( 112a) of the second set, the rods of the second set being fixed together in an endless loop, the rods (112a) of the downstream part of the rods of the second set being in contact with the rods of the third set of rods, to move debris retained by the second filter towards a collection chamber (125). Device according to claim 7, in which each of the rods (112a) of at least a portion of the second set of rods comprises hooks (112e, 112g) arranged along the rod on areas of contact with the rods (14a) of the third set of rods, to drive debris wrapped around the rods of the third set of rods towards the collection chamber (25, 125). Device according to one of claims 1 to 8, in which:
the rods (12b) of the first set of rods are spaced from each other by a distance (L12, L22) greater than or equal to a spacing distance (W12, W22) of the rods (12a, 112a) of the second set of stems, and/or
the rods (14a) of the third set of rods are spaced from each other by a distance (L23) less than the spacing distance (W22) of the rods (112a) of the second set of rods. Device according to one of claims 1 to 9, in which:
the rods (12b, 52b) of the first set of rods are attached to one end on the collection chamber side (25) via an L shape extending downstream in the flow direction, to allow for debris driven by the rods (12a) of the first set of rods to be driven towards the collection chamber without being sheared and without blocking the advancement of the rods of the second set of rods, or else
the rods (12b, 52b) of the first set of rods are attached only at one end opposite the collection chamber (25). Device according to one of claims 1 to 10, comprising:
a fourth set of parallel rods (11) arranged upstream of the first set of rods (12b), and/or
a screen (13, 113) arranged downstream of the second set of rods (12a, 112a), the width of the meshes (L14, L24) of the screen being less than a distance (W12, L12, W22, L22, L23) of spacing of the rods of the second set of rods or of the rods (14a) of the third set of rods. Device according to one of claims 1 to 11, in which the rods (11, 12a, 12b, 112a, 14a) of at least one of the sets of rods have a tapered straight section. Device according to one of claims 1 to 12, in which the main conduit (120) comprises:
an inlet opening (121) receiving the fluid flow,
an outlet opening (122),
a downstream section (120b) channeling the flow of fluid towards the outlet opening, the outlet opening having a surface area smaller than a surface area of the inlet opening, the surfaces being considered in a plane perpendicular to a longitudinal axis (X) of the main conduit, and
an upstream section (120a) channeling the flow of fluid to be filtered having entered the main conduit towards the first and second sets of rods (12a, 112a, 12b), and in which:
the upstream section (120a) presents in a plane passing through the longitudinal axis (X) of the main conduit an internal profile forming with the direction of the flow or the longitudinal axis of the main conduit an angle of zero or between 0 and 16°, and or
the downstream section (120b) presents in a plane passing through the longitudinal axis (X) of the main conduit a rectilinear or curved internal profile and forming with the direction of the flow an angle between 0 and 20, and preferably between 4 and 9°, and/or
the surface of the outlet opening (122) is adjusted so that the speed of the fluid flow leaving the main conduit is between 80 and 110% of the speed of the fluid around the outlet opening, and /Or
the surface area of the outlet opening (122) is between 0.1 and 5 times the total surface area for passage of the fluid through the first and second sets of rods (12b, 12a, 112a), and/or
the upstream section of the conduit (20, 120) has a bulge on its exterior face. Device according to one of claims 1 to 13, in which the main conduit (20, 120, 60) has a section of circular, elliptical, trapezoidal, triangular, polygonal, square or rectangular shape, or a shape composed of these shapes. Filtering system comprising a plurality of filtering devices (1, 10) according to one of claims 1 to 14, fixed side by side across a fluid flow. Filtering system according to claim 15, in which the filtering devices (1, 10) are arranged in a primary conduit (120) comprising:
an inlet opening (121) receiving the fluid flow,
an outlet opening (122),
a downstream section (120b) channeling the flow of fluid towards the outlet opening, the outlet opening having a surface area smaller than a surface area of the inlet opening, the surfaces being considered in a plane perpendicular to a longitudinal axis (X) of the primary conduit, and in which:
the upstream section (120a) presents in a plane passing through the longitudinal axis (X) of the primary conduit an internal profile forming with the direction of the flow or the longitudinal axis of the primary conduit an angle of zero or between 0 and 16°, and or
the downstream section (120b) presents in a plane passing through the longitudinal axis (X) of the primary conduit a rectilinear or curved internal profile and forming with the direction of the flow an angle between 0 and 20, and preferably between 4 and 9°, and/or
the surface of the outlet opening (122) is adjusted so that the speed of the fluid flow leaving the primary conduit is between 80 and 110% of the speed of the fluid around the outlet opening, and /Or
the surface area of the outlet opening (122) is between 0.1 and 5 times the total surface area for passage of the fluid through the first and second sets of rods (12b, 12a, 112a), and/or
the upstream section of the primary conduit has a bulge on its exterior face.