EP2287411A1 - Device for periodical discharge and tank for a clarification plant using such a device - Google Patents

Abstract

The periodic discharge device (1) comprises a base (4) for attaching to the bottom of the tank comprising an outlet opening (7) contacting with an evacuation opening, a stopper vertically movable between a lower position in which the stopper is sealed on the outlet opening and an upper position, a displacement float (5) that vertically moves in the tank and is connected with the stopper for moving it upward to a level of preset water in the tank, a device for holding the stopper in the upper position, and a triggering device. The periodic discharge device (1) comprises a base (4) for attaching to the bottom of the tank comprising an outlet opening (7) contacting with an evacuation opening, a stopper vertically movable between a lower position in which the stopper is sealed on the outlet opening and an upper position, a displacement float (5) that vertically moves in the tank and is connected with the stopper for moving it upward to a level of preset water in the tank, a device for holding the stopper in the upper position, and a triggering device, which prevents the moving of the float before a preset water level is reached in the tank. The tank has an opening for evacuation of wastewater formed in one of its walls. The holding device allows the return of the stopper in the lower position at the time of complete evacuation of water from the tank. The holding device comprises cylindrical float balls, which are movable within the device in the vicinity and on one side of the opening of the outlet. The float balls comprise a spud that is connected with a shoulder of the stopper, and an eccentric weight arranged parallel to its generator below the spud. The float balls are vertically sliding and rotating around its longitudinal horizontal axis. The base supports a pedestal that forms a box, which is elevated and contacted with the base. The float balls are arranged along a first axis of the pedestal passing through the center of the outlet opening. The triggering device is a float rotating around a horizontal axis at one of its ends, and comprises a locking finger engaging in a selective manner with the pedestal or a connected part. The float is mounted vertically and sliding along two guiding columns arranged along a second axis of the pedestal, where the second axis is perpendicular to the first axis. The locking finger is connected with a window of a guiding set mounted on the guiding columns. Independent claims are included for: (1) a tank; and (2) a process for evacuating a tank by periodic discharge.

Description

Field of the invention

The present invention relates to the field of wastewater treatment and more particularly to a device with periodic discharge, or flushing device, and a tank for a purification system for domestic or industrial wastewater comprising such a device.

State of the art

Water purification is a set of techniques that consist in purifying water to either recycle wastewater in the natural environment, or to transform natural water into drinking water. There are two main techniques for water purification, including techniques adapted to biological and physico-chemical sectors. In both techniques, the wastewater must be collected and directed first to a sewer and then, via a feeder, to a treatment plant. The feed devices may be pumping systems, or comprising solenoid valves or self-priming systems, and are arranged inside the liquid-fed tanks.

Pumping systems and solenoid valves require a power supply, which is often a constraint because the treatment plants are generally installed in the field, being away from sources of electricity. This also represents an expensive solution, because they also require regular maintenance and consume electrical energy.

Self-priming systems are self-triggering systems and allow to overcome the aforementioned drawbacks. Such a self-priming system allowing periodic discharges of water for a purification plant may be a siphon device, as described in document FR 2,690,955 . The device is installed in a liquid container which is continuously fed and allows the container to be emptied automatically when a pre-established level of liquid is reached in the container. The system includes an exhaust duct connected to a cylindrical float at one of its ends, the opposite end passing through the side wall of the container. The float moves, under the effect of the fluid supplying the container, between a high filling position of the float and a low position of emptying via the conduit discharge. While being of autonomous operation, this system finds its limits by allowing only a partial emptying of the container. Indeed, a residual volume of liquid is present at the bottom of the tank, equivalent level to the diameter of the float, so that the container is never completely empty. Thus, sludge and other sediment from the wastewater accumulate at the bottom of the container. As a result, cleaning operations must be performed regularly to keep the system operational.

The document FR 2 792 346 discloses an automatic flushing device for wastewater comprising a drain pipe disposed horizontally near the bottom of a tank, with one of its ends passing through a side wall of the tank, the opposite end of the drain pipe being closed off by a swivel flap. The device comprises locking members of the pivoting valve in the open position and in the closed position of the drain pipe, these locking members being actuated by floats connected to pivoting arms. As in the case of the previous document, the automatic flushing device according to this document has the main disadvantage of not completely emptying the tank during automatic emptying, a cleaning pipe and a valve being provided for cleaning the sludge which is accumulate at the bottom of the tank. Moreover, because it uses floats connected to rods actuated by pivoting arms that perform large amplitudes in operation, the device occupies a large part of the volume of the tank, while having multiple joints that can be subject to blockages or malfunctions in such a wastewater environment, often muddy.

Other documents propose evacuation of the liquid from a reservoir through an opening made directly at the bottom of the latter. Such an automatic flush device is described in the document FR 523 281 . The device is placed inside a tank which has a bowl formed in the bottom wall of the tank, the bowl being connected to a discharge pipe. The device comprises a set of several vertical and coaxial cylindrical floats connected to each other and slidable along a guide rod. The guide rod has a shutter valve at its lower end, while its upper end is driven by all the floats when it lifts. The device thus constituted allows the shutter valve to remain applied on its seat by the pressure of the water, the assembly rising from the seat to open the access to the discharge pipe when the float furthest from the shutter is bathed by the liquid of the tank and rises. Water from tank is evacuated and the valve closes the drain pipe and the device is ready for a new cycle. While producing intermittent flushing with total tank emptying, this device is not intended for use with sewage or containing sludge in suspension that could settle in the bowl and adversely affect the operation of the device.

The document FR 2 914 660 it describes an automatic flushing device comprising a tank communicating with a wastewater pipe. The conduit is connected to the bottom of the tank and forms a sealing seat which cooperates with a float plug which periodically closes the conduit. The cap is connected to two floats arranged vertically movable along guide columns. In operation, in the absence of water in the tank, the plug is at the bottom of the tank and closes the evacuation pipe. When the water level rises in the tank, the cap is gradually immersed and then driven upwards by the floats which move with the rise of the level of liquid in the tank. During the upward stroke of the floats, the cap is lifted, under the expansion of a compression spring, and ensures a clear opening of the discharge port. The plug follows in its course the movement of the liquid, so that the closure of the conduit occurs when the liquid is discharged from the tank. While allowing a more reliable operation than the device of the preceding document, the automatic flushing device of this document finds its limits when it is driven by the vortex formed at the bottom of the tank by the evacuation of the column of liquid which implies an early closure of the discharge port, before the liquid is completely removed from the tank.

Object of the invention

The object of the invention is to overcome at least in part these drawbacks and to propose a device for periodic discharge of wastewater which is an automatic and autonomous operation, while allowing a complete emptying of the tank and being reliable in operation .

Another object of the invention is to propose a device for periodic discharge of wastewater which is of safe operation, being free of any electrical, magnetic or mechanical component at risk of blockage, while being of compact construction and which can be manufactured in an economical way.

Another object of the invention is a periodic waste discharge device designed to be easily removable for maintenance purposes.

Another object of the invention is to provide a tank used in a wastewater treatment system of construction and economic realization, while being easy maintenance.

• une base de fixation au fond de la cuve comportant un orifice de sortie d'axe vertical en communication de fluide avec ledit orifice d'évacuation ;
• un bouchon obturateur mobile verticalement entre une position basse dans laquelle il est appliqué de manière étanche sur ledit orifice de sortie et une position haute, écartée de ce dernier ;
• un flotteur de déplacement mobile verticalement dans la cuve et coopérant avec ledit bouchon pour l'entraîner vers le haut, à un niveau d'eau préétabli dans la cuve,

du fait qu'il comporte un dispositif de maintien dudit bouchon en position haute en étant apte à bloquer ledit bouchon en position haute, lorsque ledit bouchon est amené en cette position par ledit flotteur de déplacement, ledit dispositif de maintien étant apte ensuite à dégager ledit bouchon permettant un retour de ce dernier en position basse au moment de l'évacuation complète de l'eau de la cuve.These objects are achieved with a periodic discharge device adapted to be arranged inside a tank for receiving and containing wastewater, said tank having a discharge port of waste water formed in one of its walls , said device comprising:

• a bottom fixing base having a vertical axis outlet port in fluid communication with said discharge port;
• a shutter plug movable vertically between a low position in which it is sealingly applied to said outlet port and a high position, spaced from the latter;
• a floating float vertically movable in the tank and cooperating with said cap to drive it upwards to a pre-established water level in the tank,

in that it comprises a device for holding said plug in the up position, being able to block said plug in the raised position, when said plug is brought into this position by said displacement float, said holding device then being able to release said plug allowing a return of the latter in the low position at the time of the complete evacuation of the water from the tank.

The periodic discharge device of the invention comprises a base and fixing means inside and at the bottom of a wastewater receiving tank, and is capable of sealing, selectively, in particular depending on the level water in the tank, the outlet located at the bottom of the base and communicating with the water outlet of the vessel. Wastewater includes untreated or partially treated water.

The water evacuation port of the tank can be made at the bottom of the tank or in one of the side walls of the tank and is connected to a wastewater pipe passing through the tank. The displacement in vertical translation of the shutter plug between a sealed position of the outlet orifice where it rests by gravity and a release position of this opening is done using a float displacement plug, the float moving under the action of the buoyancy force applied by the liquid from the tank to the float.

According to the invention, the stopper takes two distinct positions: a low sealing position of the outlet orifice and therefore of the orifice or discharge pipe of the tank and a high position of opening of the orifice of output, the device comprising holding means in this upper position of the plug. Thus, the plug takes two stable positions: a first, low, when it bears in gravity against the seat of the outlet orifice and a second, high, in which it is supported by the holding means which thus allow to delay the closing of the outlet orifice as long as the water is still present in the tank. This makes it possible to ensure complete emptying of the tank, and this automatically, because the shutter cap is automatically brought to the upper position by the float of displacement, to a pre-established level of water in the tank, and it remains in this position. high position until the water is discharged from the tank, when the holding device becomes inactive, allowing the shutter plug to fall on the seat of the outlet port. Thus, the operation of the device is automatic, both opening and closing, being controlled by the variation of the water level in the tank, without using other actuating means (such as electrical, magnetic , etc.), which ensures an economical and reliable operation over time of the device.

Preferably, said holding device comprises at least one floating flask which is movable inside the device, in the vicinity and on one side of said outlet orifice, said float flask having a lug which cooperates with a shoulder of the closure plug.

Such a float balloon is located inside the device, in the lower part thereof and close to the outlet orifice of the tank and, as a result, it is sensitive to variations in the outlet water level. of device. The lug of the float balloon is thus adapted to mount and hold the shutter plug in the up position, then down, with the water level, to release the shutter plug which thus returns to the sealing position of the outlet orifice.

Advantageously, said balloon is cylindrical and is mounted with the possibility of vertical sliding and pivoting about a horizontal axis when it comes into abutment. vertically.

Such a cylindrical float balloon horizontal axis can thus mount vertically inside the device, along with the water level in the tank, then pivot about a horizontal axis to lock in position the plug.

Preferably, said fixing base supports a base forming a box which is raised and in fluid communication with the base.

The base thus provides support and fixation of the entire device at the bottom of the tank, the base being provided for supporting the elements of the device at a raised level, above the base. The flow of water between the base and the base makes it possible to obtain a complete emptying of the caisson, the float balls then being able to bear against the bottom of the latter.

Advantageously, said float balloon comprises an eccentric weight arranged parallel to its generatrix being close below said pin. In a variant, said float balloon comprises an eccentric spigot which cooperates with a grooved path made inside the box.

The arrangement of an eccentric weight within a float balloon or the eccentric mounting of said float balloon allows a pivoting movement of the balloon when it comes into vertical sliding stop. The pivoting of the float balloon is done in such a way as to rotate the float spig from the outside towards the inside in the direction of the shutter plug and to lock it in position.

Preferably, the device comprises two float balloons arranged along a first axis of the base passing through the center of the outlet orifice, this to allow a more stable and secure hold in the upper position of the closure plug.

Advantageously, the periodic discharge device of the invention comprises a triggering device which prevents movement of the displacement float before a preset water level is reached in the tank. This makes it possible to obtain a high-speed displacement of the float and thus a free clearance of the plug of the outlet orifice.

Preferably, said trigger device is a trigger float pivotally mounted about a horizontal axis at one of its ends and having a locking pin selectively engaging the base or a part connected thereto. .

In a variant, it is possible to use a release locking device triggered by the pressure of the water on the float, for example of the ratchet or spring type. However, it is preferred to use a trigger float connected to the displacement float, because its operation is directly connected to the water level in the tank, for greater reliability.

Advantageously, said displacement float is slidably mounted vertically along two guide columns arranged along a second axis of the base perpendicular to said first axis.

Such an arrangement along perpendicular axes passing through the center of the opening of the base and therefore in the center of the outlet orifice of the vessel, allows a close arrangement of the various components of the device for a compact construction of the latter.

Preferably, said locking finger cooperates with a window of a guide assembly mounted on said guide columns. This represents a simple and reliable fixing solution in the desired position corresponding to the trigger level of the device in the position of the locking finger and therefore the float displacement to a preset level. In a variant, several windows can be made in one of the elements of the guide assembly in order to be able to adjust the trigger level of the device.

The objects of the invention are also achieved with a vessel comprising a periodic discharge device according to the invention.

Advantageously, the invention also relates to the use of a periodic discharge device according to the invention and / or a vessel comprising it in a wastewater treatment system.

• le déplacement en translation verticale d'un bouchon obturateur du dispositif à décharge périodique entre une position basse, où il est appliqué, par gravité, de manière étanche sur le siège de l'orifice de sortie, et une position haute en étant entraîné par un flotteur de déplacement à un niveau d'eau préétabli dans la cuve ;
• le blocage en position haute du bouchon obturateur par un dispositif de maintien qui est mis en place par l'arrivée en position haute dudit bouchon ;
• le retour en position basse du bouchon obturateur au moment de l'évacuation complète de l'eau de la cuve.

The object of the invention is also achieved with a method of emptying by periodic discharges of a vessel adapted to receive and contain waste water within which is installed a periodic discharge device having a fixing base at the bottom of the tank and having an outlet port in fluid communication with a discharge port of the tank, because it comprises the following steps:

• the displacement in vertical translation of a closure cap of the periodic discharge device between a low position, where it is applied, by gravity, in a sealed manner on the seat of the outlet orifice, and a high position being driven by a floating float at a pre-established water level in the tank;
• locking in the upper position of the closure cap by a holding device which is put in place by the arrival in the upper position of said cap;
• the return to the lower position of the shutter plug at the time of complete evacuation of the water from the tank.

Description of figures

• The figure 1a illustrates a top view of the periodic discharge device of the invention shown in the closed position of the water outlet orifice and the figure 1b is a sectional view according to the plane AA of the figure 1a .
• The figure 2a illustrates a top view of the periodic discharge device of the invention shown in the open position of the water outlet orifice and the figure 2b is a sectional view along the plane BB of the figure 2a .
• The figure 3a illustrates a top view of a subset located at the top of the periodic discharge device of the invention and the figure 3b a sectional view taken with the plane CC of the figure 3a .
• The figure 4a illustrates a view from above of a subassembly located at the bottom of the periodic discharge device of the invention, the figure 4b illustrates a sectional view taken with the plane DD of the figure 4a showing the device in the closed position of the outlet port and the figure 4c is a sectional view taken with the same plane DD, but illustrating the device in the open position of the outlet orifice.
• The Figures 5a to 5d illustrate top, front, side and rear views of the periodic discharge device of the invention.
• The figure 6a illustrates a sectional view of a vessel comprising the periodic discharge device of the invention and the Figures 6b and 6c top views of the whole of the figure 6a according to two embodiments.
• The figure 7a is a sectional view of a view comprising the periodic discharge device of the invention and the Figures 7b and 7c top views of the whole of the figure 7a according to two embodiments.
• The figure 8a illustrates a schematic sectional view, and the figure 8b a view from above, of a tank assembly comprising a receiving portion of a periodic discharge device of the invention and a portion forming a distribution view.
• The Figures 9 and 10 illustrate in a simplified manner, alternative arrangement and attachment of a periodic discharge device of the invention inside a vessel.
• The figure 11 a illustrates a view from above and the Figures 11b and 11c illustrate the first a sectional view made with the EE plane and the second a sectional view taken with the plane FF of the figure 11 a part of the components of the device according to an alternative embodiment of the invention.
• The figure 12 illustrates a side view of a float balloon of the device according to an alternative embodiment of the invention.
• The figure 13 illustrates a front view of a shutter plug of the device according to an alternative embodiment of the invention.

List of landmarks: 1 Periodic discharge device 2 Shutter plug 3 Drain pipe 4 Based 5 Movement float 6 Holding device 7 Exit port 8, 8 ' Float ball 9 ergot 10 shoulder 11 Basement 12, 12 ' box 13 Offset weight 14 Trigger device 15 Trigger float 16 Horizontal axis 17 Locking finger 18, 18 ' Guide column 19 First axis 20 Second axis 21 Tank 22 Bottom end 23 Conical seat 24 First section 25 Second section 26 Upper end 27 Upper end 28 Flow passage 29 Lifting flange 30 crossing 31 Fixing holes 32 Float assembly 33 Pregnant 34 Tube 35 Central hole 36 Lateral orifice 37 Guiding assembly 38 Muff 39 brace 40 Washer 41 Front side wall 42 Rear side wall 43 Through hole 44 Pivot 45 Hollow body 46 Arms 47 Orifice 48 Window 49 Background 50 Flow orifice 51 Support 52 Opening 53 trunnion 53 ' Eccentric spigot 54 stopper 55 Pivot 56 Lower front 57 Slot 58 Wall 59 Targette 60 Screw 61 embankments 62 Cavity 63 look 64 Distribution wall 65 Distribution look 66, 67.68 Secondary evacuation pipes 69 Mounting brackets 70 Grooved path 71 Side wall 72 Introductory part 73 Guide part 74 stopper 75 Holding plate 76 Through hole 77 Evacuation hole 78 Drain sleeve 79a, 79b Groove 80 Security groove NOT Trigger level Detailed description of the invention

The Figures 1a to 5d illustrate a periodic discharge device 1 of the invention. This device is intended to be installed in a tank or a look ( Figures 6a to 10 ) part of a wastewater treatment system (not shown in the figures). The purification system comprises means for supplying wastewater from means for collecting domestic wastewater (and possibly industrial or rainwater) in the pipes of a sewerage network; means of transporting wastewater; as well as wastewater treatment means.

More particularly with reference to Figures 5a to 5d , the periodic discharge device of the invention comprises a fixing base 4 intended to bear against the bottom of a tank 21 ( Fig. 6a ) receiving and storing wastewater or partially treated water. Fixing holes 31 are made in the thickness of the base 4 and cooperate with fixing screws at the bottom of the tank. The waters usually arrive discretely, via a feed duct (not shown), into the tank. The periodic discharge device 1 of the tank allows it to store the water and return it in bursts, from a pre-established water level in the tank. The water exits the tank via a discharge pipe 3 and is then directed to treatment means or in a natural environment, for example being used for soil irrigation.

The periodic discharge device 1 of the invention comprises a shutter plug 2 movable vertically in the tank 21. As is better visible on the figures 1b and 2b , the shutter plug 2 has a conical bottom end 22 (possibly provided with a seal), intended to bear tightly on a conical seat 23 which materializes the outlet orifice 7 of the base 4. The lower end 22 extends upwards by a first section 24, then by a second section 25 of diameter greater than the first. The two sections are separated by a shoulder 10. The plug 2 is a hollow tube and has flow passages 28 in its lower part communicating with the water of the tank, the tube being closed at its upper end 27 by a buffer equipped with a handling ring. A lifting flange 29 is fixed at a predetermined height on the second section 25 of the plug 2, the flange has a cylindrical shape of internal diameter equal to that external of the plug 2, and has a lower end face which comes into contact with the upper end face of a float 5, as will be explained later.

The periodic discharge device 1 of the invention comprises, in its lower part, a base 6 supported by means of a cross member 30 on the base 4 and, in its upper part, a float assembly 32 suspended at a predetermined distance from the above the base 6. Two guide columns 18 are fixedly mounted at the bottom of the base 6 to guide the float assembly 32 in its vertical sliding movement inside the vessel.

In the following, a float comprises an element having a positive buoyancy with respect to the water present in the tank and being able to move when it is immersed in water under the action of the buoyancy force applied by the liquid from the tank to the float.

The float assembly 32 is better visible on the Figures 3a and 3b . It comprises a displacement float 5 which is an airtight enclosure 33 filled with air having a positive buoyancy with respect to the water. The displacement float 5 has a generally cylindrical shape whose dimensions are established so as to ensure the floatability of the float assembly 32. The enclosure 33 has a central orifice 35 to allow the passage of the shutter plug 2 and two lateral orifices 36 located equidistant from the central orifice 35, on the axis of symmetry of the assembly called the second axis 20. The lateral orifices 36 are embodied by cylindrical tubes 34 sealed to the enclosure 33, each tube 34 extending upwards by a height at least equal to that of the enclosure 33. The float assembly 32 comprises a fixed guide assembly 37, at a height determined as a function of the level of water in the tank, on the guide columns 18. The guide assembly 37 comprises two sleeves 38 connected in the upper part by a spacer 39. The fixing of the guide assembly 37 on the columns 18 is made using two targett 59, preferably made of stainless steel, fixed on the upper face of the spacer 39. During assembly, the pin of the bolt 59 passes through the sleeve 38 and is inserted into a corresponding hole (not shown) of the column 18 then is fixed in this position. A sleeve 38 is a cylindrical tube of outside diameter smaller than that of the tubes 34 provided at its base with a washer 40 of outside diameter greater than that of the tubes 34 so that the washers 34 form a bottom stop for the chamber 33 5. The internal diameter of the sleeves 38 and washers 40 is such that they allow their insertion with a sliding play on the guide columns 18.

The float assembly 32 also includes a trigger device 14 which prevents the movement float 5 from moving before a pre-set water level is reached in the vessel. The trigger device 14 comprises a trigger float 15 pivotally mounted about a horizontal axis 16. The upper end face of the enclosure 33 supports two vertical front side walls 41 and two rear walls 42 also vertical. The front walls 41 have a through hole 43 at their upper part intended to support a pivot 44 ( Fig. 5b and 5c The triggering float 15 comprises a hollow body 45 having a U-shaped cross-section (or generally parallelepipedal shape open at its lower part), the body being held laterally by two articulated-mounted arms 46. rotatable around the pivot 44. Each arm 46 has at its upper part an orifice 47 for mounting on the pivot 44 and, in its lower part, a locking pin 17 ( Fig. 1b and 2b ) intended to cooperate with a window 48 ( 3B ) of rectangular general shape made at a pre-established level in the thickness of the sleeve 38.

According to the invention, the periodic discharge device 1 comprises a device 6 for holding the shutter plug 2 in a raised or open position, comprising two floating balloons 8 mounted movably inside the base 11, as will be better explained. with reference to Figures 4a to 4c .

In figure 4a it is noted the base 4 of generally square shape having a fixing hole 31 in each of its corners, the cross member 30 supporting the base 11. The base 11 has a generally parallelepipedal shape of square base having a bottom 49 being open to its part upper and forming a box 12 for receiving two float balloons 8. The bottom 49 is provided with flow orifices 50. In the center of the box 12 is arranged a support 51 of generally parallelepipedal shape of square base, open at its upper part. and whose bottom is pierced with an opening 52 allowing the shutter plug 2 to pass therethrough. The various components of the assembly shown in FIGS. Figures 4a to 4c are arranged along two axes of the base, passing in the center of the outlet orifice 7, in particular a first axis 19 and a second axis perpendicular to the first axis. Thus, the columns 18 are arranged at equal distance from the outlet orifice 7, on the second axis 20. Two float balloons 8 are arranged equidistant from the outlet orifice 7, on the first axis 19.

The float balloon 8 is a sealed enclosure, of generally cylindrical shape and having two end journals at its longitudinal axis. The float balloons 8 are mounted inside the box 12 so that their longitudinal axis is horizontal and parallel to the second axis 20. The float balloons 8 are caused to move vertically upwards until their trunnions 53 are supported on a stop 54. In order to allow a removable assembly of the floats inside the box 12, the stops 54 are rotatably mounted around a pivot 55. After installation of the floats 8 within the box 12, the stops 54 are manually turned downward so that their lower end face is oriented towards the float balloon 8 to each form a horizontal bearing abutment of the pin 53 in the high position. Each float balloon 8 comprises a lug 9 disposed on an outer side, in a central zone being perpendicular to the generatrix of the cylinder that constitutes the float balloon. Each float balloon further comprises an eccentric weight 13 arranged parallel and over the entire length of its generator. The eccentric weight is arranged close to the lug 9 and promotes the rotation of the float balloon 8 when it reaches a high stop, as will be explained later.

The support 51 has the shape of a parallelepiped box of square base open upwards, with a slot 57 made on each of its vertical walls located on the first axis 19. The slot 57 has a width greater than that of the spur 9 with which it is made to cooperate in operation and has a bottom wall 58 inclined so as to be parallel to the lug 9 of the float balloon 8 when it rests at the bottom of the box 12 ( Fig. 4b ).

The elements constituting the periodic discharge device assembly 1 are removably assembled. Thus, to obtain the entire device, is introduced inside the box 12 of the base 11 (it is understood that the base 4, the cross member 30 and the base 6 are formed in one piece), the two float balloons 8 , one on each side of the support 51, so that the lug 9 of each balloon is supported on the bottom wall 58 of a slot 57. The abutment 53 is then tilted in the low position by pivoting it around its pivot 54. The float assembly 32 is then introduced onto the columns 18 which are fixedly mounted at the bottom of the box 12 of the base 11. The lowering of the float assembly 32 is stopped by blocking the screws 59 on the columns 18, each in a hole of the column located at a predetermined level, corresponding to the water level that one wants to control with this device. We then install the shutter plug 2 in the center of the base 9 until it bears on the conical seat 23 of the outlet orifice 7. The shutter plug 2 is provided with the lifting flange 29 fixed in a predetermined position also chosen depending on the water level. The device is thus in operating condition, the whole being better visible to Figures 5a to 5d . The device is installed inside a tank 21 by fixing it at the bottom thereof by means of fixing screws 60 ( Fig. 9, fig. 10 ).

Conversely, to dismantle the device, the shutter plug 2 is first extracted, the screws 59 of the columns 18 are disengaged, the float assembly 32 is lifted and removed, and then the stops 53 are tilted backwards. allows the extraction of two float balloons 8. Such an operation is done quickly and easily by hand, it takes about a minute and this without the need for tools or disassembly tools.

In operation, in the absence of water in the tank 21, the shutter plug 2 rests on the conical seat of the outlet port 7 of the base 4 under the effect of gravity. The shutter plug 2 thus seals the access to the discharge pipe 3, as better visible in the figure 1 b. When the water begins to arrive in the tank 21, the periodic discharge device 1 is gradually immersed. The water rises by penetrating inside the box 12 and raises the floats 8 which rise until their pins 53 come into abutment against the lower end face 58 of the stops 54. The water level continues to rise to the inside of the tank 21 to a trigger level N ( fig.2b ). When the level N is reached in the tank, the trigger float 15 is driven upwards and pivots about the horizontal axis 16 of the pivot 44, so that the locking pin 17 leaves the window 48 and allows the rise 5. During its upward stroke, the displacement float 5 drives the shutter plug 2. As soon as the lower end 22 of the plug 2 is moved away from the conical seat 23, the float balloons 8 pivot about their axis. longitudinal under the influence of their eccentric weight 13, making the lug 9 bears on the upper part of the slot 57 and form seat for the shoulder 10 of the closure plug 2 ( Fig. 2b ). The outlet orifice 7 being open, the water can enter the discharge port 3 and empty the tank 21. The closure plug rests with its shoulder 10 on the lugs 9 during the emptying of the tank. When the water level in the tank has become very low, more particularly when there is no more water in the box 12, the float balls 8 fall to the bottom of it under the effect of gravity. and release the shutter plug 2 which returns to the closed position by pressing on the seat conical 23 of the outlet port 7. The periodic discharge device is now ready for a new cycle. Such a device therefore has an autonomous operation and guarantees periodic emptying automatically.

The components of the automatic discharge device of the invention are advantageously made of a plastic material by injection techniques, bonding or welding of their components. These materials may be, for example, PPH (or polypropylene H) or HDPE (high density polyethylene).

The periodic discharge device 1 of the invention is capable of operating with a discharge pipe having a discharge diameter of between 40 to 100 mm, between 100 mm and 180 mm, between 180 mm and 250 mm or between 250 mm and 315 mm, the components of the device being dimensioned for each interval of drain diameters.

For example, the dimensioning of a periodic discharge device 1 operating with a drain pipe having a diameter of between 40 and 100 mm, the enclosure 33 of the displacement float 5 has a diameter of approximately 600 mm, and a height of about 77 mm. The closure plug 2 has a height of the second section 25 of about 800 mm and a diameter of about 125 mm, and a height of the first section of about 180 mm and a diameter of about 90 mm. The float balls 8 have a length of about 370 mm and an outside diameter of about 110 mm. The eccentric weight 13 is calculated so as to ensure the rotation of the balloon in the high position, while allowing its retention in position; for example, such a weight is between 200 and 250 g.

The nominal flow rate of such a device with periodic discharge is about 10 m ³ / h for a discharge diameter of 40 mm and about 50 m ³ / h for a discharge diameter of 100 mm.

The Figures 6a to 6c illustrate a device with periodic discharge 1 in operation inside a tank 21. The tank 21 is a tube of circular section ( 6B ) or square ( Fig. 6c ) or polygonal (not shown) higher than that of the device 1, the bottom may be flat or inclined being provided with fixing means of the base of the device 1 at the bottom of the tank and connection means thereof This tank 21 is advantageously made of a plastic material, such as HDPE, and is installed in a cavity 62 of the ground surrounded by embankments 61. HDPE is high density polyethylene (specific gravity greater than 0.94 g / cm ³ ).

In other embodiments illustrated on the Figures 7a to 7c , the periodic discharge device 1 is disposed in a tank 21 of low height, made of a plastic material such as HDPE, installed in a look 63 concrete (for example by stacking concrete nozzles on a cast concrete base). Concrete manholes are tubes of circular section ( Fig. 7b ) or square ( 7C ) or polygonal (not shown) and are installed in a cavity 62 of the ground being surrounded by embankments 61.

The discharge pipe 3 can communicate with a distribution view allowing it to convey water further into the purification system or to a spreading system.

Another alternative embodiment of tank 21 comprising a periodic discharge device 1 of the invention is illustrated in FIGS. Figures 8a and 8b . In this variant, the tank 21 of circular section comprises a distribution wall 64 which divides its volume into two parts: a first receiving the periodic discharge device 1 and a second forming a distribution view 65. The discharge pipe 3 crosses the distribution wall 64 and allows the water sent by the device 1 to fall to the bottom of the eye 65 where it is distributed by three secondary discharge pipes 66,67,68.

The Figures 9 and 10 illustrate different modes of attachment of the periodic discharge device 1 of the invention to the bottom of a tank 21. Thus, the figure 9 illustrates a tank 21 having a discharge pipe 3 which passes through one of its side walls. The base 4 of the device is raised relative to the bottom of the tank, it comprises fastening lugs 69 cooperating with fixing screws 60 at the bottom of the tank 21. figure 10 illustrates a periodic discharge device 1 of the invention fixed with its base 4 directly at the bottom of a tank 21 above a discharge orifice passing through the bottom wall of the tank 21.

The Figures 11a to 11c illustrate an alternative embodiment of a part of the elements of the device of the invention. In particular, Figures 11a to 11c illustrate a modified box 12 'having two columns 18' forming part of a base 11 '. The box 12 'according to this variant comprises two grooved paths 70 formed on either side of the second axis 20 in each of the side walls 71 of the box 12'. A guide path 70 comprises an insertion portion 71 a guiding portion 72 and a stop 73 each cooperating with a pin 53 'of a float balloon 8' of the figure 12 .

During assembly of the device, each float flask 8 'is introduced by orienting it with the lug 9 in the direction of a slot 57 and sliding its trunnions 53' along the introduction portions 72 of the grooved path 70. In operation, when the water level rises in the box 12 ', the float balloon 8' rises, under the thrust of the Archimedes force, following with its trunnions 53 'the guide portion 73 of the grooved path 70 to the stops 74. When the pre-established water level N has been reached in the tank, the blanking plug 2 is released and the float balls 8 'pivot about their eccentric journals 53', causing the lug 9 to take support on the upper part of the slot 57 and form seat for the shoulder 10 of the plug 2. Subsequently, the operation of the device is similar to that of the embodiment described above.

As best seen in the figure 11c , the bottom of the box 12 'further comprises two through holes 76 for each receiving a guide column 18' provided with a discharge port 77 at its base. The axis of the discharge orifice 77 is transverse to the axis of the through orifice 76, the two orifices communicate for the evacuation of the water present in the box 12 '. Around each guide column 18 'is threaded a drain sleeve 78 floating (which is a hollow or sealed piece, but made so as to float on the water). A holding plate 75 is arranged on top of the box 12 'in order to limit in the upper part the stroke of the drain sleeves 78. In operation, when the water level rises in the tank, the drain sleeves 78 also rise up to At the level of the holding plate 75. When the tank is emptied of water, the polluting elements of small size present at the bottom of the box 12 ', such as mud, leaves, etc. are evacuated through the discharge holes 77, then through the outlet port 7. The drain sleeves 78 continue to descend to take place at the bottom of the box 12 'thus closing the outlets 77. , the water flows from the box 12 'via the orifices 50 of the box 12' as in the embodiment described with reference to the preceding figures.

The figure 12 illustrates in side view a float flask 8 'made according to a variant of the invention. The float balloon 8 'has a pin 53' mounted eccentrically with respect to the longitudinal central axis of the float balloon 8 ', being arranged radially close to the base of the pin 9. Such a float balloon can then be mounted with its eccentric pin 53 'in grooved path 70 formed in the side walls 71 of the box 12', as described with reference to Figures 11a to 11c . It can thus rotate when the water level rises in the box 12 'and the float balloon 8' is stopped by the stop 74 of the grooved path 70, without the need for an additional eccentric weight 13. Such an eccentrically mounted floating balloon 8 'is in the form of a sealed and empty cylinder.

The figure 13 illustrates a blanking plug 2 according to an alternative embodiment of the invention. The plug 2 has a plurality of grooves 79a, 79b in which an O-ring of corresponding diameter (not shown) is inserted. Such an O-ring in a groove 79a, 79b forms a lifting stop to replace the lifting flange 29 of the preceding figures. Several grooves may be provided on the second section 25 of the shutter plug 2, which allows to adapt the trigger to a certain level of water in the tank. The O-ring can also be easily moved, by hand, from one groove to another and thus adjust the trigger level of the device. A safety groove 80 is also provided near, for example about 30 mm, the shoulder 10. This allows the blocking of the shutter plug 2 by the lugs 9 of the float balloons 8 in case of triggering of the trigger float 15 before the pre-established water level N is reached in the tank.

Other variants and embodiments of the invention may be envisaged without departing from the scope of its claims.

Claims (14)

Periodic discharge device (1) adapted to be arranged inside a tank (21) intended to receive and contain wastewater, said tank having a discharge orifice of wastewater formed in one of its walls , said device comprising: - a base (4) for attachment to the bottom of the vessel having an outlet port (7) of vertical axis in fluid communication with said discharge port; - a shutter plug (2) vertically movable between a low position in which it is sealingly applied to said outlet port (7) and a high position, spaced from the latter; a displacement float (5) movable vertically in the tank and cooperating with said stopper (2) to drive it upwards to a pre-established water level in the tank,
characterized in that it comprises a holding device (6) of said cap in the high position which is able to block said cap (2) in the up position when said plug is brought into this position by said displacement float (5), said holding device (6) being then able to release said plug (2) allowing a return of the latter in the low position at the time of the complete evacuation of water from the tank (21). Device according to claim 1, characterized in that said holding device (6) comprises at least one float balloon (8, 8 ') which is movable inside the device, in the vicinity and on one side of said outlet orifice (7), said float balloon (8,8 ') having a lug (9) which cooperates with a shoulder (10) of the closure plug (2). Device according to claim 2, characterized in that said balloon (8,8 ') is cylindrical and in that it is mounted vertically sliding and pivotable about a horizontal axis when it comes into vertical abutment. Device according to one of the preceding claims, characterized in that said base (4) supports a base (11) forming a box (12,12 ') which is raised and is in fluid communication with the base (4). Device according to one of claims 2 to 4, characterized in that said float balloon (8) comprises an eccentric weight (13) arranged parallel to its generatrix being close below said lug (9). Device according to one of claims 2 to 4, characterized in that said float balloon (8 ') comprises an eccentric pin (53') which cooperates with a grooved path (70) formed inside the box (12 ') . Device according to one of claims 4 to 6, characterized in that it comprises two float balloons (8) arranged along a first axis (19) of the base passing through the center of the outlet orifice (7). Device according to one of the preceding claims, characterized in that it comprises a triggering device (14) which prevents the movement float (5) from moving before a pre-established water level is reached in the tank . Device according to claim 8, characterized in that said triggering device (14) is a trigger float (15) pivotally mounted about a horizontal axis (16) at one of its ends and comprising a locking pin ( 17) selectively engaging the base (6) or a part connected thereto. Device according to one of claims 8 or 9, characterized in that said displacement float (5) is slidably mounted vertically along two guide columns (18, 18 ') arranged along a second axis (20) of the base ( 6) perpendicular to said first axis (19). Device according to one of claims 9 or 10, characterized in that said locking pin (17) cooperates with a window (48) of a guide assembly (37) mounted on said guide columns (18, 18 ') . Vessel (21) comprising a periodic discharge device (1) according to one of the preceding claims. Use of a periodic discharge device (1) according to one of the claims 1 to 11 and / or a tank according to claim 12 in a wastewater treatment system. A method of periodically discharging a tank adapted to receive and contain waste water, inside which is installed a periodic discharge device comprising a base for fixing to the bottom of the tank and having an outlet orifice in communication with fluid with an evacuation orifice of the tank, characterized in that it comprises the following steps: the displacement in vertical translation of a shutter plug of the periodic discharge device between a low position, where it is applied, by gravity, in a sealed manner to the seat of the outlet orifice, and an upper position being driven by a float for moving to a pre-established water level in the tank; - Blocking in the upper position of the closure cap by a holding device which is implemented by the arrival in the upper position of said cap; - The return to the lower position of the shutter plug at the time of complete evacuation of the water from the tank.

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