EP3012374A1 - Screen rake with floating beam - Google Patents

Abstract

The invention relates to a device for cleaning a grid (3) arranged in a watercourse, in particular a fish and eel holding grid at the hydropower plant inlet or the pond feed inlet. fresh water and channels, comprising a movable beam (1) provided with a scraper (2) arranged to scrape said grid (3) and a means of translation of said movable beam (1), said movable beam (1). ) further comprising a float (4) arranged to allow said movable beam (1) to float when the float (4) is activated, in particular when it is filled with air, and to allow said movable beam (1 ) to sink when the float (4) is disabled, for example filled with water.

Description

The invention relates to the field of grids input of hydroelectric plants, or the supply of channels or freshwater hydraulic basins, to stop especially fish and eels.

In the context of watercourse management, the public bodies ask the hydroelectric power producers that the water intakes in the factories should be equipped with grids with the lowest possible bar spacing, ideally 20 to 25 mm, so that fish and eels do not enter the machines where they may be destroyed by the blades or wheels of the turbines.

The approximation of the bars imposes an increase in the surface of the filtering grid to allow an equivalent flow of water to pass. Often for an old work, it is necessary to double the surface, which forces to reduce the inclination of the grid, of the order of thirty degrees compared to the horizontal one. Such a grid is therefore clogged faster, and requires regular cleaning, called screening.

The present invention relates more particularly to a screen, device specially adapted to perform such screening.

The document US4,752,402 discloses a screen operated by lifting the grid in vertical position to remove the impurities. Nevertheless, on the one hand, certain impurities do not fall spontaneously even when the grid is in a vertical position, on the other hand such lifting is restrictive, and requires overcoming the forces of the current; moreover during the lifting the surface of passage of the grid becomes much weaker, and the flow of water can not pass any more.

The present invention proposes to remedy at least some of the aforementioned drawbacks and proposes a solution that allows to screen with less energy consumption and / or less water flow reduction.

To this end, the invention relates to a device for cleaning a grid disposed in a watercourse, in particular a fish and eel holding grid at the entrance to a hydroelectric plant or pond feed. freshwater and channels, comprising a movable beam provided with a scraper arranged to scrape said grid and a translational means of said movable beam. This device is particular in that said movable beam further comprises a float arranged to allow said movable beam to float when the float is activated, particularly when it is filled. of air, and to allow said movable beam to sink when the float is off, for example filled with water.

Such arrangements reduce the actuating forces of the mobile beam, using its ability to float or sink.

• ledit flotteur peut présenter une forme évasée vers le bas, et ouverte vers le bas, afin d'évacuer naturellement les détritus qui pourraient colmater le passage de l'air,
• ledit flotteur peut comporter des chicanes agencées pour permettre le remplissage ou le vidage d'air du flotteur, permettant de supprimer les entrées de produits flottants dans l'installation de tuyauteries,
• ledit flotteur peut comporter des clapets d'ouverture et de fermeture desdites chicanes, permettant ainsi le contrôle de l'état activé ou désactivé du flotteur,
• ledit moyen de translation peut comporter un bras articulé, disposé entre un châssis fixe et ladite poutre mobile, solution simple et robuste pour déplacer la poutre mobile,
• ledit bras articulé peut comporter deux segments articulés entre eux et un vérin disposé entre les deux segments de sorte à être apte à actionner un écartement angulaire entre les deux segments,
• ledit dispositif peut comporter une rampe de guidage, ladite poutre mobile comportant en outre un galet apte à se déplacer sur ladite rampe de guidage de sorte à guider le mouvement de ladite poutre mobile, ladite rampe étant disposée escamotable, de sorte à permettre au galet se présentant sous ladite rampe de remonter au-dessus de la rampe par escamotage de la rampe, puis de se poser sur ladite rampe une fois remise en place,
• ladite rampe de guidage peut être articulée autour d'une de ses extrémités, et l'escamotage consister en une rotation de ladite rampe autour de ladite extrémité, conférant là encore une solution simple et fiable d'escamotage,
• ledit dispositif peut comporter une rampe de descente agencée pour guider ledit galet de sorte à faire descendre ladite poutre mobile selon une trajectoire prédéterminée jusqu'à ce que le flotteur atteigne la surface de l'eau,
• ledit dispositif peut comporter une rampe de montée agencée pour guider ledit galet de sorte à amener ladite poutre mobile de l'extrémité supérieure de ladite grille vers une position de garage prédéterminée.

According to other characteristics:

• said float may have a flared shape downwards, and open downwards, in order to naturally evacuate the detritus that could clog the passage of the air,
• said float may comprise baffles arranged to allow the filling or emptying of air from the float, to suppress the inflow of floating products in the pipe installation,
• said float may comprise opening and closing flaps of said baffles, thus enabling control of the activated or deactivated state of the float,
• said translation means may comprise an articulated arm disposed between a fixed frame and said movable beam, a simple and robust solution for moving the movable beam,
• said articulated arm may comprise two segments hinged together and a jack arranged between the two segments so as to be able to actuate an angular spacing between the two segments,
• said device may comprise a guide ramp, said movable beam further comprising a roller adapted to move on said guide ramp so as to guide the movement of said movable beam, said ramp being arranged retractable, so as to allow the roller to presenting under said ramp to go up above the ramp by retraction of the ramp, then to land on said ramp once put back in place,
• said guide ramp can be articulated around one of its ends, and the retraction consists of a rotation of said ramp around said end, again conferring a simple and reliable solution of retraction,
• said device may comprise a descent ramp arranged to guide said roller so as to lower said movable beam in a predetermined path until the float reaches the surface of the water,
• said device may comprise a rise ramp arranged to guide said roller so as to bring said movable beam from the upper end of said gate to a predetermined garage position.

The advantage of the present invention is that the floating beam being floating, it can be guided by the water itself, which reduces the forces to be applied by mechanical devices.

Other features and advantages of the invention will emerge from the following detailed description relating to an exemplary embodiment given by way of indication and not limitation.

• la figure 1 représente une vue de côté d'un dégrilleur selon l'invention.

The understanding of this description will be facilitated with reference to the accompanying drawings, in which:

• Figure 1 shows a side view of a screen according to the invention.

As shown in Figure 1 attached, the present invention relates to a movable beam screen. The mobile beam 1 comprises a scraper 2 of length substantially equal to the length of a screen 3 to be screened. Said grid 3 is for example arranged at the entrance of a hydroelectric plant, in an entrance of about 3 meters high and 6 meters wide, inclined by 28 ° relative to the horizontal, and may have a length of 6 meters and a width of 6 meters. Its lower end is disposed at the bottom of said inlet upstream of the stream, and its upper end reaches the surface of the water, so that all the water entering the plant is forced to pass through the grid 3 and the stream of water tends to push the degrillates up the grid 3, where they can then be recovered and discharged into the watercourse adjacent to the plant.

Said movable beam 1 further comprises a float 4, which can extend over the entire length of the mobile beam 1. The float 4 has a flared shape and open at the bottom to naturally evacuate the detritus that could prevent the passage of the air. The float 4 comprises in its upper part baffles 5, with valves 6.

The movable beam 1 is connected to a frame 7 by means of an articulated arm 8, and actuated by means of a jack 9, preferably an electric jack, to avoid pollution by oil.

The mobile beam 1 further comprises at least one, and preferably two rollers 10 disposed at the ends of the movable beam 1, and configured to roll on ramps 11, 12 and 13 exposed in more detail below.

The float 4 is configured to contain a volume greater than the equivalent weight of the mobile beam assembly 1 and arm 8, preferably 30% greater than the equivalent weight, so as to ensure total flotation of the arm 8 when the float 4 is filled with air.

• attente en station de garage au point A, bras 8 replié, galets de la poutre mobile 1 en position A sur une rampe escamotable 11 sensiblement horizontale, et disposée articulée à la jonction avec une rampe de descente 12, pour une raison mise en évidence plus loin,
• autorisation de départ cycle, les galets 10 s'appuient sur la rampe escamotable 11 pour rejoindre le point B, par actionnement du vérin 9,
• poursuite de l'ouverture du bras 8 par actionnement du vérin 9, les galets 10 s'appuient sur la rampe de descente 12, jusqu'à atteindre le point C, où le flotteur 4 se pose sur l'eau, ouverture vers le bas, et se met à flotter,
• poursuite de l'ouverture du bras 8, le flotteur 4 assurant la flottaison de la poutre mobile 1, jusqu'au point D,
• ouverture des clapets 6 pour laisser s'échapper l'air contenu dans le flotteur 4 par les chicanes 5,
• sombrage de la poutre mobile 1 qui atteint ainsi le point E, où le racleur 2 entre en contact avec l'extrémité inférieure de la grille 3,
• début de fermeture du bras 8 par actionnement en sens contraire du vérin 9, ce qui produit le raclage de la grille 3 par le racleur 2, jusqu'au point F, où le flotteur 4 commence à émerger,
• ouverture des clapets 6 pour permettre l'entrée de l'air dans le flotteur 4, et éviter l'effet ventouse qui l'empêcherait d'émerger,
• poursuite de la fermeture du bras 8 jusqu'à ce que le racleur 2 atteigne l'extrémité supérieure de la grille 3 déversant les impuretés dans une goulotte 14, les galets 10 atteignant au point G le début d'une rampe de montée 13,
• poursuite de la fermeture du bras 8, les galets 10 roulant sur la rampe de montée 13, provoquant l'escamotage de la rampe escamotable 11 jusqu'au passage des galets 10, la rampe escamotable 11 se remet en place après le passage des galets 10, et les galets 10 se reposent sur la rampe escamotable 11 au point A en station de garage, et le cycle peut recommencer.

The course of a scraping cycle is then as follows:

• waiting in garage station at point A, arm 8 folded, rollers of the mobile beam 1 in position A on a retractable ramp 11 substantially horizontal, and arranged articulated at the junction with a ramp down 12, for a reason highlighted more far,
• Authorization of starting cycle, the rollers 10 rely on the retractable ramp 11 to reach the point B, by actuation of the cylinder 9,
• continued opening of the arm 8 by actuation of the cylinder 9, the rollers 10 are based on the ramp down 12, to reach the point C, where the float 4 is placed on the water, opening to the bottom , and starts to float,
• further opening of the arm 8, the float 4 ensuring the floating of the movable beam 1, to the point D,
• opening the valves 6 to allow the air contained in the float 4 to escape through the baffles 5,
• sinking of the movable beam 1 which thus reaches the point E, where the scraper 2 comes into contact with the lower end of the grid 3,
• beginning of closure of the arm 8 by actuation in the opposite direction of the cylinder 9, which produces the scraping of the gate 3 by the scraper 2, to the point F, where the float 4 begins to emerge,
• opening the valves 6 to allow the entry of air into the float 4, and avoid the suction effect that would prevent it from emerging,
• further closing of the arm 8 until the scraper 2 reaches the upper end of the grid 3 discharging the impurities in a chute 14, the rollers 10 reaching at point G the beginning of a ramp 13,
• further closing of the arm 8, the rollers 10 rolling on the ramp 13, causing the retraction of the retractable ramp 11 to the passage of the rollers 10, the retractable ramp 11 is put back in place after the passage of the rollers 10, and the rollers 10 rest on the retractable ramp 11 at point A in the garage station, and the cycle can start again.

The length of the mobile beam 1 being substantially the same as that of the grid 3, the entire gate field 3 is cleaned in a single pass.

The screen according to the invention thus operates with a single actuator, the cylinder 9, and a control of the valves 6. It is also possible to realize the invention without valves 6, the baffles 5 being configured to sufficiently slow the air outlet of the float 4 to allow the mobile beam 1 to reach the point D before sinking. Like the water at point F, it suffices to wait for the time necessary for the air to enter the baffles 5 before continuing the movement towards point G.

• déclenchement obtenu par l'action d'un bouton poussoir, en local ou à distance,
• déclenchement obtenu par une temporisation réglable, située dans une armoire de commande,
• déclenchement par détection de perte de charge entre l'amont et l'aval de la grille 3, permettant une action uniquement en cas d'encombrement de la grille 3, et une réduction maitrisée de la consommation d'énergie pour le fonctionnement du dégrilleur.

One can provide a manual mode of operation, for maintenance, in which a skilled operator can perform each movement individually by a button box, and an automatic mode, in which the screen performs only complete cycles such as that described here. -before. In automatic mode, three types of cycle starts can be provided:

• triggered by the action of a push button, locally or remotely,
• tripping achieved by an adjustable delay, located in a control cabinet,
• triggering by detection of pressure drop between the upstream and downstream of the gate 3, allowing action only in case of congestion of the gate 3, and a controlled reduction of the power consumption for the operation of the screen.

The advantage of the present invention lies in particular in that it is proposed a simple operation screen, lightweight, simple design, with a minimum of civil engineering work for its installation, and which uses the best forces of nature. The control can be totally electric, thus avoiding hydraulic systems, pollutants, and it is very simple and can be done by a PLC with remote control. Monitoring can be done over the internet.

Although the invention has been described with respect to a particular embodiment, it is understood that it is in no way limited and that various modifications of shapes, materials and combinations thereof can be made. various elements without departing from the scope of the invention.

Claims (10)

Device for cleaning a grid (3) arranged in a watercourse, in particular a fish and eel holding grid at the entry of a hydroelectric plant or supply of freshwater pond and channels, having a movable beam (1) provided with a scraper (2) arranged to scrape said grid (3) and a means for translating said movable beam (1), characterized in that said movable beam (1) comprises in in addition to a float (4) arranged to allow said movable beam (1) to float when the float (4) is activated, in particular when it is filled with air, and to allow said movable beam (1) to sink when the float (4) is deactivated, for example filled with water. Device according to the preceding claim, wherein said float (4) has a flared shape downward and open downward. Device according to one of the preceding claims, wherein said float (4) comprises baffles (5) arranged to allow the filling or emptying of air float (4). Device according to the preceding claim, wherein said float (4) comprises valves (6) for opening and closing said baffles (5). Device according to one of the preceding claims, wherein said translation means comprises an articulated arm (8) disposed between a fixed frame (7) and said movable beam (1). Device according to the preceding claim, wherein said articulated arm (8) comprises two segments articulated between them and a jack (9) disposed between the two segments so as to be able to actuate an angular spacing between the two segments. Device according to one of the preceding claims, comprising a guide ramp (11), said movable beam (1) further comprising a roller (10) able to move on said guide ramp (11) so as to guide the movement of said movable beam (1), said ramp (11) being arranged retractable, so as to allow the roller (10) under said ramp to rise above the ramp (11) by retracting the ramp (11), then to land on said ramp (11) once put back in place. Device according to the preceding claim, wherein said guide ramp (11) is articulated around one of its ends, and the retraction consists of a rotation of said ramp (11) around said end. Device according to one of claims 7 to 8, comprising a ramp (12) arranged to guide said roller (10) so as to lower said movable beam (1) in a predetermined path until the float ( 4) reaches the surface of the water. Device according to one of claims 7 to 9, comprising a ramp (13) arranged to guide said roller (10) so as to bring said movable beam (1) from the upper end of said grid (3) to a predetermined garage position.

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