SEDIMENT REMOVAL DEVICE

Abstract

A sediment removal device (1) (III) comprising a plate (2) intended to be fixed to a seabed (I) and at least one scale (4) fixed to the plate (2) to form, between them, a pocket (10) having a first opening (12), the scale (4) being movable between a position folded against the plate (2) in which the pocket (10) is deflated and a position away from the plate (2) in which the pocket (10) is inflated by a volume of water, the transition from the folded position to the away position being ensured by the penetration of a volume of water into the pocket (10) under the action of a marine current (II, IV). Figure to be published with the abbreviation: Fig. 1

Description

Description Title of the invention: DEVICE FOR EVACUATING SEDIMENTS Technical field The invention relates to the field of removing sediment from a seabed or river bed. STATE OF PRIOR ART It is well known that some seabeds, such as riverbeds or port areas, experience the accumulation of large amounts of sediment. However, this accumulation of sediment can fill the seabed in question, making it unfit for navigation. Indeed, with an accumulation of sediment, the seabed approaches the water surface and the depth of water available for navigation is reduced. To remove sediment, it is known to carry out dredging operations with a specialized vessel. Dredging consists of scraping, or even digging, the seabed to extract the sediment. T1 is a complex operation requiring the use of specialized vessels. A dredging operation is an expensive operation due to the use of a specialized vessel, and the cost of fuel required for the specialized vessel, but also because the port, channel, river, or shipping lane concerned may be closed to navigation during the entire dredging operation. In addition, dredging is subject to increasingly strict regulations. Therefore, in this context, it is necessary to provide a sediment disposal device that can dispose of sediment autonomously, without restricting maritime traffic and while being inexpensive. Statement of the invention To this end, according to a first aspect, a sediment removal device is proposed which comprises a sheet intended to be fixed to a seabed and at least one scale fixed to the sheet to form between them a pocket having a first opening, the scale being movable between a position folded against the sheet in which the pocket is deflated and a position separated from the sheet in which the pocket is inflated by a volume of water, the passage from the folded position to the separated position being ensured by the penetration of a volume of water into the pocket under the action of a sea current. Thus, the device according to the invention uses a sea current to move the scales of the device. The device being positioned on a seabed, it naturally becomes covered with sediment. The movement of the scales, under the simple action of a ocean current, allows the sediment present on the device to be evacuated. The device according to the invention therefore operates autonomously, without restricting maritime traffic and while being inexpensive compared to a dredging operation. According to a particular arrangement, the device comprises several series of scales distributed parallel to each other. According to a particular arrangement, the scale has a substantially trapezoidal geometry, with two parallel bases, a large base having the first opening and a small base whose dimensions are smaller than the dimensions of the large base, and two non-parallel sides, the non-parallel sides being fixed to the sheet. In an even more particular arrangement, the small base has a second opening. According to a particular arrangement, the device comprises an air injection member arranged to inject air into the pocket. According to an even more particular arrangement, the air injection member is arranged to inject air into the pockets of a first series of scales relative to the direction of the sea current. According to a particular arrangement, the sheet comprises a plurality of eyelets adapted to cooperate with fixing means for fixing the sheet to the seabed. According to a particular arrangement, the water table has openings suitable for marine fauna to pass through. Brief description of the drawings The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of at least one exemplary embodiment, said description being made in relation to the attached drawings, among which: [Fig.1] is a schematic representation from above of a sediment removal device according to the invention: [Fig.2] is a schematic top view of a scale of the sediment removal device; [Fig.3] is a schematic side view of the sediment removal device according to the invention with the scales in the folded position; [Fig.4] is a schematic side view of the sediment removal device according to the invention with the scales in the spread position. DETAILED PRESENTATION OF IMPLEMENTATION METHODS Sediment disposal device With reference to [Fig.1], a sediment evacuation device 1 III is proposed ( [Fig.3]). The device 1 comprises a sheet 2 and at least one scale 4 fixed to the sheet 2 to form between them a pocket 10 ([Fig.4]). According to a particular arrangement, the tablecloth 2 is a flexible tablecloth. The tablecloth 2 may be made of polymer materials or of textiles made of natural fibers coated with a polymer. It is specified that by natural fibers, it is meant linen, wool or cotton fibers or others. The sheet 2 is intended to be fixed on a seabed I by fixing means. It is specified that in this document, by seabed is meant an area at the bottom of a sea, or the bottom of a port, or the bottom of a bay, or even the bed of a river. According to a particular arrangement, the fixing means are chosen from piles, cables or straps, ropes or chains. To ensure the cooperation of the fixing means and the sheet 2, the latter comprises a series of eyelets 6 distributed over the surface of the sheet 2 through which the fixing means pass. According to one embodiment, the eyelets 6 are metal eyelets. In a particularly advantageous manner, fastening means such as cables, ropes, chains or straps make it possible to adjust the tension of sheet 2 against the seabed I. It is specified that it is possible to combine the different types of fastening means. In particular, it is possible to combine the piles with fastening means such as cables, ropes, chains or straps. In this case, a first end of a fastening means, such as a cable, a rope, a chain or a strap, is fixed to an eyelet 6 and a second end of this fastening means is fixed to a pile. According to a particular arrangement, the sheet 2 has openings 8 adapted to be crossed by marine fauna. This is a particularly advantageous arrangement. Indeed, the sheet 2 is adapted to be fixed on a seabed I. As such, the sheet 2 covers the seabed I on which it is fixed. The openings 8 allow the circulation of marine fauna through the sheet 2. Thus, the openings 8 make it possible to prevent the marine fauna from being trapped in the sheet 2, when the sheet 2 is fixed on a seabed I. As indicated previously, the device 1 comprises at least one scale 4 fixed to the sheet 2. More precisely, the scale 4 is fixed to the sheet 2 to form with the sheet 2, the pocket 10 which has at least one first opening 12. The scale 4 is fixed to the sheet 2 so as to be movable between a position folded against the sheet 2 in which the pocket 10 is deflated and a position separated from the sheet 2 in which the pocket 10 is inflated by a volume of water. As will be described below, the transition from the folded position to the spread position is ensured by the penetration of a volume of water into the pocket 10 through the first opening 12 under the action of a sea current. According to a particular arrangement, scale 4 is made from a flexible sheet which may be of the same nature as sheet 2. According to a particular arrangement, shown diagrammatically in [Fig.!] and [Fig.2], the scale 4 has a substantially trapezoidal geometry, with two parallel bases, a large base having the first opening 12 and a small base whose dimensions are smaller than the dimensions of the large base, and two non-parallel sides connecting the bases together, the non-parallel sides being fixed to the sheet 2. The two non-parallel sides of the scale 4 can be fixed to the sheet 2 by means of, for example, sewing, welding or gluing. This technical arrangement allows scale 4, in the spaced position, to be inclined relative to water table 2, which facilitates the evacuation of sediments III resting on scale 4. According to a particular embodiment, the small base is also integral with the sheet 2. Furthermore, when the scale 4 has a trapezoidal geometry, according to an even more particular embodiment, the pocket 10 comprises a second opening 16 at the level of the small base, the first opening 12 having a surface area greater than the surface area of ​​the second opening 16. As will be described below, this arrangement allows the generation of a Venturi effect when a sea current II or IV passes through the pocket 10 going from the first opening 12 towards the second opening 16. In addition, as shown schematically in [Fig. 1], according to a particular arrangement, the device 1 comprises several series of scales 4 where the series are distributed parallel to each other along the marine current II or IV. According to a particular arrangement, two adjacent parallel series overlap. This arrangement makes it possible to maximize the number of scales 4 on a sheet 2. As will be described below, the pockets 10 are adapted to inflate or deflate under the action of a sea current. It is specified that by sea current, it is understood a tidal current II or IV, a current of a river (or of any watercourse). It is also specified that the inflation and deflation of the pockets 10 can consist of a small variation of a volume of water in the pockets 10. In other words, according to the example presented here, when a pocket 10 is deflated, it is folded against the sheet 2. According to a particular arrangement, the device 1] also comprises an air injection member making it possible to assist the transition from the folded position to the position spread by injecting air into the pocket. According to this arrangement, the air injection member makes it possible to blow air into the pockets 10 to inflate them. According to a variant, the air injection member may comprise a pump and a pipe connected to the pump and opening into the pocket 10. According to a particular arrangement, the air injection member only blows air into the pockets 10 of a first series of scales 4 relative to a direction of the tidal current IV. This arrangement makes it possible to initiate a chain reaction of accelerated inflation of all the pockets 10. Operation of the sediment evacuation device [Fig.3] and [Fig.4] show schematically the operation of the device | when a tidal current II or IV allows the pockets 10 to be inflated or deflated (or a volume of water in the pockets 10 to vary). More precisely, [Fig.3] and [Fig.4] show schematically an example in which the device 1 is oriented so that the pockets 10 deflate under the action of a rising tidal current II and inflate under the action of a falling tidal current IV. As will be detailed below, this orientation is particularly effective for evacuating sediments III towards the open sea. The device 1 is fixed on a seabed I by means of the sheet 2. With reference to [Fig.3], under the action of a rising tidal current II the pockets 10 deflate and the scales 4 are in the folded position against the sheet 2. In this position, sediments III can be deposited on the scales 4. When the tide falls, as shown schematically in [Fig. 4], the falling tidal current IV inflates the pockets 10. In other words, when the tide falls, the falling tidal current IV forces water into the pockets 10 through the first openings 12 which then face the falling tidal current IV, which inflates them. The swelling of the pockets 10 causes the scales 4 to move into a spread position. The movement of the scales 4 stirs the sediments III deposited on the scales 4 which are then carried away by the tidal current IV. Furthermore, according to the embodiment presented here, the trapezoidal geometry of the scales 4 is such that in the spaced apart position, the scales 4 are inclined relative to the sheet 2. The inclination of the scales 4 promotes the detachment of the sediments III which, thus, are more easily evacuated by the falling tidal current IV. The orientation that the device 1 presents here makes it possible to use the falling tidal current IV to evacuate the sediments III. This orientation is particularly clever in the case, for example, where the device 1 is positioned in a port. Indeed, the falling tidal current IV then makes it possible to evacuate the sediments ITI and to carry them out to sea outside the port. Furthermore, according to the embodiment shown here, each pocket 10 comprises a first opening 12 and a second opening 16. As indicated previously, the first opening 12 has a surface area greater than the surface area of ​​the second opening 16. This arrangement promotes the generation of a Venturi effect when the falling tidal current IV passes through a pocket 10 and emerges through the second opening 16. This Venturi effect promotes the suction of sediments III which could be present in a pocket 10, to evacuate them. In addition, according to the embodiment presented here, the device 1 comprises several parallel series of scales 4, which overlap. The overlapping makes it possible to circulate sediments III from one series to another until they are evacuated from the device 1. It is remarkable that in a particularly advantageous manner, when the device 1 comprises several series of overlapping scales 4, the presence of a Venturi effect makes it possible to facilitate the movement of the sediments III from one pocket 10 to another. Thus, device 1 very advantageously allows sediments to be removed from a seabed, autonomously, without restricting maritime traffic and while being inexpensive.

Claims

Claims

1. Device (1) for removing sediment (IIT) characterized in that it comprises a sheet (2) intended to be fixed on a seabed (I) and to the less a scale (4) fixed to the sheet (2) to form between them, a pocket (10) having a first opening (12), the scale (4) being movable between a folded position against the tablecloth (2) in which the pocket (10) is deflated and a position away from the tablecloth (2) in which the pocket (10) is inflated by a volume of water, the passage of the folded position to the spread position being ensured by penetration of a volume of water into the pocket (10) through the first opening (12) under the action of a sea current (IL IV).

2. Device (1) according to claim 1, comprising several series of scales (4) where the series are distributed parallel to each other others.

3. Device (1) according to any one of the preceding claims, in which the scale (4) has a substantially tra- geometry pedestal, with two parallel bases, a large base presenting the first opening (12) and a small base whose dimensions are in- smaller than the dimensions of the large base, and two non-parallel sides, the non-parallel sides being fixed to the tablecloth (2).

4. Device (1) according to claim 3, wherein the small base has a second opening (16).

5. Device (1) according to any one of the preceding claims comprising an air injection member arranged to inject air in the pocket (10).

6. Device (1) according to claims 2 and 5 in combination, in which the air injection member is arranged to inject air into the pockets (10) of a first series of scales (4) relative to the direction of the ocean current (IV).

7. Device (1) according to any one of the preceding claims wherein the sheet (2) comprises a plurality of eyelets (6) adapted to cooperate with fixing means for fixing the tablecloth (2) to the seabed.

8. Device (1) according to any one of the preceding claims, in which the sheet (2) has openings (8) adapted to be crossed by marine fauna.