SYSTEM AND METHOD FOR COLLECTING WATER FROM UNDERWATER AND / OR COASTAL SOURCES WITH OVERFLOW BASIN

Abstract

The invention relates to a system for obtaining water from at least one underwater spring, which system comprises a separation means (1) for separating the spring water from the seawater, an overflow tank (5) comprising an opening for receiving the water and a collection device (4) for collecting the spring water spring, the overflow tank (5) comprising an overflow wall configured such that the spring water travels over the overflow wall in order to enter, under gravitational force, into the collection device (4). Moreover, the overflow cross-section of the overflow tank (5) is strictly greater than the flow cross-section of the opening and the overflow cross-section of the overflow tank (5) is located above sea level (8). Figure 1 to be published.

Description

[0001] SYSTEM AND METHOD FOR CAPTURING WATER FROM UNDERWATER AND / OR COASTAL SOURCES WITH OVERFLOW BASIN

[0002] Technical field

[0003] The invention relates to the field of capturing water flowing into the sea (underwater, coastal sources) whose salinity is lower than that of sea water, in particular fresh water or drinking water in order to use it for populations and / or crops and / or livestock.

[0004] Prior art

[0005] There are many techniques for collecting water from springs that flow into the sea.

[0006] We are particularly aware of patent application FR 2,857,389, which concerns a collection system for discharging part of the fresh water into the sea when the flow of fresh water is too high, for example in the event of flooding of the spring.

[0007] However, this system can generate pressure variations at the outlet of the source into the sea and therefore induce a reduction in the flow rate of the source and cause the source to exit through another route.

[0008] Another technique consists of inserting a pipe directly at the spring outlet and creating a watertight connection between the pipe and the outlet, so as to force the spring water to pass into the collection system. This technique is notably described in patent application FR 2,792,664. This technique modifies the pressure balances and can therefore modify the flow rate of the spring by generating another preferred passage for the water via an outlet other than the one where the collection system was implemented. In addition, this blockage of the spring water can disrupt the local marine balance since the fauna and flora at the spring outlet were accustomed to a salinity lower than that of seawater.

[0009] Another technique involves using a bell above the spring outlet. Patent applications WO2009 / 001,145, FR2,926,569, FR2,795,109 and WO2007 / 017,703 relate to such a technique. Since spring water has a lower density than seawater, it will rise and be trapped in the bell. A pipe and a pump are then used to convey the water to the surface or to land. However, the larger the bell, the more the spring water and seawater will mix, so that the water collected will be saltier than the water leaving the spring. In addition, the use of the pump generates a vacuum, thus disturbing the pressure balance and can cause some of the salt water to re-enter the system. The recovered water will therefore be saltier than the water initially leaving the spring.Furthermore, since the pump generates a vacuum, it may be necessary to provide real-time monitoring of the pump in order to adapt it to pressure variations. Using real-time monitoring complicates the system.

[0010] Summary of the invention

[0011] To overcome the drawbacks of the prior art, the invention seeks to capture water from the underwater source without changing the pressure balance (or by a slight overpressure) at the outlet of the underwater source, preventing the source from finding another outlet and preventing the capture of salty seawater. By slightly changing the pressure balance, it is meant that the pressure at the outlet of the source is unchanged or slightly overpressured, the overpressure value of which depends on the conditions of the source (presence or absence of other outlets of the source nearby, pressures, temperature, salinity, etc.) and that the flow rate of the source will be little affected by the possible slight overpressure, for example, the flow rate of the source with or without the capture system of the invention varies by less than 5%.Thus, the invention does not generate a depression at the outlet of the source unlike the systems of the prior art which use a pump to recover the fresh water at the outlet of the source.

[0012] To do this, the invention relates to a system for capturing water from at least one water source opening through an underwater outlet comprising at least one separation means for separating the water from the source from the sea water (one separation means for each water source), each separation means being connected to an overflow basin comprising an opening for the inlet of the water from the source, and one (at least one) water recovery device (a single water recovery device or several, for example a separate water recovery device linked to each source), each overflow basin comprising an overflow wall configured so that the water from the source passes over said overflow wall to enter the water recovery device by gravity.Furthermore, the overflow section at the outlet of each overflow basin is strictly greater than the passage section of the opening of the overflow basin considered and the overflow section (horizontal) of the overflow basin is located above sea level.

[0013] The invention relates to a system for capturing water from at least one underwater water source comprising at least one separation means for separating the water from the at least one source from sea water, each separation means being connected to a separate overflow basin, each overflow basin comprising an opening for the entry of water from the at least one source, the capture system comprising at least one water recovery device, each overflow basin comprising an overflow wall configured so that the water from the at least one source passes over said overflow wall to enter, by gravity, the at least one recovery device.Furthermore, within each overflow basin, the overflow section of said overflow basin is strictly greater than the section of said opening of said overflow basin, and in that the overflow section of the overflow basin is located strictly above sea level.

[0014] Preferably, each separation means is connected to the opening of the overflow basin by a pipe, the water passage section in each pipe being strictly less than the maximum water passage section in the separation means to which the pipe is connected and in the maximum water passage section in the overflow basin to which the pipe is connected.

[0015] Advantageously, the at least one separating means comprises an envelope, preferably a flexible envelope.

[0016] Preferably, the at least one separation means comprises at least one non-return valve capable of allowing water from said source to pass outside the separation means and of preventing the passage of sea water towards the inside of the separation means.

[0017] Advantageously, said overflow wall of at least one overflow basin has the shape of a concave bowl, the opening of this at least one overflow basin being positioned at the bottom of the concave bowl, and preferably, the recovery device surrounding the concave bowl.

[0018] According to a variant of the invention, at least one overflow basin is formed by a box comprising the overflow wall, the overflow wall separating the overflow basin on one side of the overflow wall from the recovery device on the other side of the overflow wall.

[0019] According to one configuration of the invention, the system comprises adjustment means for adjusting the altitude of the overflow section of at least one overflow basin at least at the time of installation of the capture system, preferably, the system comprises adjustment means for adjusting the altitude of the overflow section of at least one overflow basin as a function of variations in flow rates and / or pressure and / or variation in density of the sea water or the water from the at least one source.

[0020] Preferably, the vertical distance zc between the outlet of each underwater source and the level of the overflow section of each overflow basin to which said outlet is connected is determined by the following formula:

[0021] Pm ■ Zs ■ 9 + P

[0022] Z c

[0023] Ps- 9

[0024] With zs the depth of the outlet of the underwater source considered relative to sea level, g the acceleration of gravity, Ap a predetermined value of overpressure greater than or equal to zero and defined according to the characteristics of the source considered, p m the density of sea water and p s the density of the water of the said underwater source considered.

[0025] According to one embodiment of the invention, the at least one recovery device comprises a pump configured to be started when the water level in the recovery device exceeds a first predetermined threshold and configured to be stopped when the water level is below a second predetermined threshold, the second predetermined threshold being less than or equal to the first predetermined threshold.

[0026] Advantageously, the capture system comprises a water storage means and a supply conduit connecting the at least one water recovery device to the storage means, the storage means being floating, and preferably capable of being disconnected from the supply conduit, or placed on the ground.

[0027] Preferably, the at least one water recovery device is floating and anchored to the ground by cables, preferably by taut cables, or placed on the ground onshore or offshore.

[0028] Advantageously, the at least one water recovery device comprises an orifice for allowing the introduction of water from an outlet of an additional water source, the orifice allowing water from said additional water source to enter the at least one water recovery device directly or indirectly, the at least one recovery device preferably comprising control means for controlling the water level in the at least one water recovery device when the orifice is below the water level.

[0029] According to an advantageous configuration of the invention, the capture system is configured to capture water from several underwater sources, said capture system comprising as many separation means and overflow basins as there are sources, each separation means being connected to a separate overflow basin, preferably the capture system comprising a single water recovery device for recovering water from all the overflow basins.

[0030] The invention also relates to a method for capturing water from at least one underwater water source in which at least the following steps are carried out using the capture system as described above:

[0031] - The water from the at least one source is separated from the sea water at an underwater outlet, by the at least one separation means;

[0032] - The water separated from the sea water is conveyed to the opening in the overflow basin; - The speed of the water in the overflow basin is slowed down by means of an overflow section of the overflow basin strictly greater than the section of passage of the water in the opening;

[0033] - The water is allowed to overflow from the overflow basin and the water is recovered, by gravity, in the recovery device, the recovery device being floating or placed on the ground, onshore or offshore, and preferably, the water is transferred from the water recovery device to a floating storage means and the floating water storage means is towed by a boat to land.

[0034] List of figures

[0035] Other characteristics and advantages of the system and method according to the invention will appear on reading the following description of non-limiting examples of embodiments, with reference to the figures appended and described below.

[0036] Figure 1 represents a first embodiment of a water collection system according to the invention.

[0037] Figure 2 shows different operating modes a), b), c) and d) of a water collection system according to the invention.

[0038] Figure 3 represents a second embodiment of a water collection system according to the invention.

[0039] Figure 4 represents a third embodiment of a water collection system according to the invention.

[0040] Figure 5 represents a fourth embodiment of a water collection system according to the invention.

[0041] Figure 6 represents a fifth embodiment of a water collection system according to the invention.

[0042] Figure 7 represents the principle of a lifting pump within the water recovery device of a collection system according to the invention.

[0043] Figure 8 represents a means of guidance at the outlet of the overflow basin of a collection system according to the invention. Figure 9 represents a sixth embodiment of a water collection system according to the invention.

[0044] Figure 10 represents a seventh embodiment of a water collection system according to the invention.

[0045] Figure 11 represents a top view of the water collection system of Figure 1 according to the invention.

[0046] Figure 12 shows a top view of a water catchment system where the overflow basin is formed by a box with an overflow wall separating the overflow basin from the recovery device located on the other side of the overflow wall.

[0047] Description of the embodiments

[0048] The terms "high", "low", "level", "altitude", "lower", "upper" mean the system or method of the invention in operating and operating position.

[0049] The terms "inlet" and "outlet" refer to the direction of flow of the fluid (water) in the system or part of the system under consideration.

[0050] By "overflow level" we mean the level at which a water / air interface occurs.

[0051] Overflow means that water flows over a wall into another container. The overflow action occurs at the overflow point.

[0052] By "overflow section" is meant the section through which water passes at the overflow level, this section being in the horizontal plane of the overflow level.

[0053] The invention relates to a system for capturing water from at least one water source opening through an underwater outlet. The source is a fresh or slightly saline water source. By "slightly saline" is meant that the salinity of the water from the source is lower than that of seawater, and more particularly of seawater located at the outlet of the source. Capturing this fresh or slightly saline water is particularly interesting in order to be able to use it to supply fresh water (or drinking water) to populations and / or livestock and / or to use it for crops.

[0054] By capturing water from multiple underwater sources, some elements can be pooled, reducing costs and reducing the environmental impact on flora and fauna. To achieve this, the capture system includes at least one separation means, at least one overflow basin (also called an overflow means), and at least one water recovery device (also called a recovery means). Each separation means separates the water leaving an underwater source from the surrounding seawater. This prevents, or at least minimizes, mixing between seawater and spring water, and thus prevents the salinity of the captured (or produced) spring water from increasing compared to that of the water leaving the source.

[0055] Each separation means is connected (directly or indirectly by a pipe) to a separate overflow basin. Thus, the water from each underwater source that has been separated from the seawater in the separation means is conveyed to the overflow basin. To achieve this, each overflow basin includes an opening for the entry of water from the separation means directly or indirectly by a pipe.

[0056] By using a given number of separation means and overflow basins, it is possible to capture water corresponding to the same given number of different sources.

[0057] The collection device can receive water from all sources: in this case, the collection system includes a single water collection device, which simplifies the system.

[0058] Alternatively, each overflow basin can be associated with a separate recovery device that can receive water from a single source: in this case, the catchment system includes as many recovery devices as sources and therefore as many recovery devices as separation means (and overflow basins). In this case, for each source, the system will have a separate separation means, a separate overflow basin and a separate recovery device. This makes it possible, for example, to manage different outlet water salinities or different water compositions.

[0059] Alternatively, the catchment system could include several water collection devices, the number of which would be fewer than the sources (and therefore the number of separation means). In this variant, at least one water collection device would be common to several overflow basins. This may be advantageous for waters with similar chemical compositions or salinities for similar future treatment.

[0060] According to the invention, each overflow basin comprises an overflow wall configured so that the water from the source (from at least one of the sources) associated with the overflow basin in question passes over the overflow wall to be conveyed (to enter directly) into the (or one of the) water recovery devices, in a gravity-driven manner: in other words, the water overflows above the overflow wall and then falls by gravity into the (or one of the) water recovery devices. The recovery device may, for example, surround the overflow basin so that the water leaving the overflow basin falls directly by gravity into the recovery device. Alternatively, the overflow wall may separate the overflow basin from the recovery device.

[0061] In a marine environment, since the salinity of spring water is lower than that of sea water, the density of spring water is lower than that of sea water and therefore, spring water naturally rises above the sea surface. When a water column is put in place, this effect no longer occurs. However, thanks to the hydrostatic pressure generated by the aquifer associated with the spring, the water still rises naturally in the column. Its operation is then similar to that of an artesian well on land. As a result, the system does not require a pump to transport the water from the spring outlet to the overflow basin and thus, the system does not generate a vacuum and avoids entraining part of the sea water in the produced water.

[0062] Preferably, the system may be designed such that the pressure of the water column exiting the underwater source is in hydrostatic equilibrium with the pressure of the seawater column located above the outlet of the underwater source so as not to disturb the pressure balance.

[0063] To maintain hydrostatic equilibrium at the outlet of the underwater source, the pressure of the water column leaving the source located above the outlet of the underwater source is preferably equal to (or very slightly higher, for example between a few millibars and 100 mbar (0.01 MPa) for example) the pressure exerted by the seawater. This can be adjusted by the height of the water column of the underwater source.

[0064] So, we have:

[0065] P s = Pa + p m - g ■ z s = Pa + p s ■ g ■ z c

[0066] Where Ps is the hydrostatic pressure at the outlet of the underwater source considered Pa the atmospheric pressure p m the density of sea water z s the depth of the underwater outlet considered relative to sea level (which therefore corresponds to the height of the seawater column above the outlet of the underwater source considered) p s the density of the water from the underwater source considered corresponding to the density of the produced water (i.e. the water captured by the capture system) z cthe height of the water column of the underwater source necessary so that the hydrostatic pressure at the outlet of the source in question is unchanged. g the acceleration of gravity Alternatively, the system can be designed so that the pressure of the water column leaving the underwater source is very slightly overpressured, by a predetermined value, compared to the pressure of the seawater column located above the outlet of the underwater source to avoid the entry of seawater (especially if the collection system is not completely watertight) on the one hand and to limit as much as possible the disturbances of the hydrostatic balance in order to avoid any loss of flow rate of the source. Indeed, if the hydrostatic balance is sufficiently disturbed, the water source risks seeing its flow rate greatly reduced, or even completely reduced, the source being able to find another more favorable outlet in the earth's subsoil.The predetermined value of the overpressure depends on the source and its conditions. This predetermined value can for example be a few millibars, for example less than 100 mbar (0.01 MPa) so as not to disturb the flow of the source too much. Thus, the pressure at the source, after installation of the capture system, is then: Ps + Ap = Pa + p. m ■ g ■ z s + Ap = Pa + p s ■ g ■ z c

[0067] Where Ps is the "normal" hydrostatic pressure at the outlet of the underwater source considered. By "normal" we mean natural, that is to say the pressure without the capture system.

[0068] Pa atmospheric pressure p m the density of sea water z s the depth of the underwater outlet considered relative to sea level (which therefore corresponds to the height of the seawater column above the outlet of the underwater source considered) ps the density of the water from the underwater source considered corresponding to the density of the produced water (i.e. the water captured by the capture system) z c the height of the water column of the underwater source necessary so that the hydrostatic pressure at the outlet of the source considered is here in very slight overpressure of the value Ap.

[0069] Ap: predetermined value of overpressure (Ap is positive) g the acceleration of gravity

[0070] In this alternative where a slight predetermined overpressure value Ap is tolerated, the height of the water column of the source in the collection system is then greater than the height of the water column of the source in the collection system where the pressure balance is strictly respected.

[0071] Thus, we obtain a column of water whose height can verify the following equation:

[0072] Pm ■ Zs ■ 9 + p

[0073] Z r = - With Ap > 0: if Ap = 0, the hydrostatic pressure balance is respected, if Ap > 0, the capture system admits a slight overpressure of predetermined value corresponding to Ap. This predetermined value is configured to prevent the entry of sea water into the capture system, in particular if the system is not completely watertight, and to not impact or have little impact on the flow rate of the source (for example, the variation in flow rate with or without the capture system can be less than 5%).

[0074] Now, as the density of sea water p m is greater than the density of the water in the underwater source p s, since spring water has a lower salinity than sea water, the freshwater column is higher than the seawater column. In other words, the outlet of the freshwater column is above the seawater surface. Therefore, the elevation of the overflow section (which is the highest point of the water column leaving the spring) is above sea level.

[0075] Thus, by respecting the hydrostatic balance or by generating a slight overpressure in the freshwater column, the system operates autonomously without human intervention. It is therefore easy to use and does not require real-time monitoring, unlike capture systems which use a pump to transport the water leaving the source to a storage basin.

[0076] The overflow section (corresponding to the outlet section) of the overflow basin is defined by the outlet of the overflow basin. It therefore corresponds to the horizontal section of the overflow basin at the upper level of the overflow wall.

[0077] Furthermore, in order to limit the height of the water jet above the overflow basin which could be linked to the pressure of the underwater source considered, it is necessary to slow down the flow of water at the level of each overflow basin. For this, the overflow section (at the outlet) of each overflow basin is strictly greater than the section of the opening (corresponding to the entry of water into the overflow basin) of the overflow basin considered to lead to a widening of the section and therefore a slowing down of the flow, and consequently a reduction in the height of the jet.

[0078] Advantageously, the capture system may comprise at least one pipe for connecting a separation means to a separate overflow basin and thus conveying water from the source to this overflow basin. The passage section of the water in the pipe is less (preferably strictly less) than the maximum passage section of the water in the separation means to which the pipe in question is connected and the maximum passage section of the water in the overflow basin to which the pipe in question is connected. Thus, the pipe may be smaller than the separation means and the overflow basin, which limits the environmental impact (in particular on fauna and flora) of the capture system.

[0079] Preferably, each separation means can be connected to the opening of a separate overflow basin by a pipe. This allows water to be collected from several sources and routed to the same location for overflow and water recovery, further limiting the environmental impact and providing greater design and manufacturing flexibility to the system.

[0080] Maximum section means the largest passage section, in the direction of water flow.

[0081] Preferably, at least one of the separation means (in particular each separation means) may comprise an envelope for establishing a physical separation between the sea water located on one side of the envelope (for example outside the envelope) and the spring water located on the other side of the envelope (for example inside the envelope). This physical separation makes it possible to avoid mixing between these two waters which are miscible with each other.

[0082] For example, the envelope can be flexible, such as a plastic sheet. By flexible, we mean that it can deform to be easily put in place on site at the time of installation, unlike a rigid envelope which cannot deform without special tools at the time of installation.

[0083] According to a characteristic of the invention, the envelope (flexible or rigid) can be fluid-tight (sea water and fresh water) to avoid any possible mixing between these fluids.

[0084] According to one implementation of the invention, at least one of the separation means (in particular each separation means) may comprise a ballasting means placed on the ground. This ballasting means may consist of a weight placed on the ground. This ballasting means makes it possible to maintain the separation means of the capture system in the intended position, surrounding the outlet of the considered source of underwater water and preferably to ensure the seal between the separation system and the ground. To ensure the seal, the ballasting means must be deformable to follow the defects in the ground. To do this, the ballasting means may comprise a torus made of a flexible fabric (deformable without using any particular tooling) and filled with solid particulate materials (concrete balls, sand for example).The solid particles provide weight allowing the system to function as ground-based ballast, and the combination of the flexible fabric and solid particles allows the ballast to deform to adapt to variations in the ground. Preferably, the ballast can be attached to the casing (flexible or rigid), preferably waterproof, to ensure separation with the least possible mixing between seawater and the water from the underwater source in question.

[0085] Advantageously, at least one of the separation means (preferably, the casing of the separation means and more preferably, each casing of each separation means) may comprise at least one non-return valve capable of allowing the water from the source to pass through the non-return valve of the separation means in question to reach the seawater and of preventing the passage of seawater through this non-return valve to reach the water from the source produced. By preventing the passage of seawater through the separation means (via the non-return valve), the increase in the salinity of the water produced by the collection system is avoided or limited. Thus, the water has little or no need to be desalinated before being used for the needs of populations, livestock or crops.Furthermore, by allowing the passage of fresh water to sea water, the flow rate can be limited and thus excessive local overpressure can be avoided which could be induced on the separation means, in particular when it is a flexible envelope for example, and possibly on the pipe, and avoid a significant jet of water at the overflow basin. This local overpressure can in particular be generated when the source is in flood and the flow rate of water leaving the source is greater than the flow rate of water which can be produced by the capture means (for example due to the pressure losses induced in the pipe).

[0086] The non-return valve can be configured to open from a predetermined criterion, this predetermined criterion can preferably correspond to the predetermined overpressure value of the water column of the source, the predetermined overpressure value depending on the conditions of the source. Therefore, a slight overpressure in the water column can be allowed to prevent the introduction of sea water into the collection system. Limitation of the flow rate by using the non-return valve can also be interesting in the case of limitation of the volume of the recovery means (volume of the tank for example), for example to prevent the water level in the recovery means from exceeding the overflow section.

[0087] Advantageously, the at least one non-return valve (preferably of each separation means) can be configured so that their opening is pressure-calibrated at a pressure higher than the pressure of the seawater at the non-return valve, so as to avoid leaks. This configuration allows automatic opening of the non-return valve as a function of the pressure, without human intervention, and without electrical or hydraulic control, which simplifies the system. According to one implementation, the at least one separation means (or each separation means) can comprise several non-return valves regularly distributed on the separation means considered (in particular on the casing) around the outlet of the underwater source considered, so as to reduce the overpressure on the separation means or to eliminate it.

[0088] Advantageously, the non-return valve(s) may be positioned on the rigid or flexible casing of at least one separation means (preferably of each separation means).

[0089] Preferably, the passage section at the outlet of each overflow basin Sb can be determined by the following Bernoulli formula as a function of the height of the jet envisaged:

[0090] Q c

[0091] 5 - -

[0092] VW

[0093] With Qc the flow rate of water produced in the overflow basin considered, g the acceleration of gravity and Hj the envisaged height of the jet.

[0094] For example, the passage section at the outlet of each overflow basin Sb may be at least 1.5 times, preferably at least 2 times, the passage section of the pipe or opening of the overflow basin in question. As a result, when the water arrives in the overflow basin, the speed is slowed down.

[0095] The diameter of the pipe D c can be determined so that the pressure losses Ah in the pipe of length L c are lower than a predetermined criterion ath crit depending on the project in which we wish to install a capture system (in particular depending on the depth of the source, the pressure of the source at its outlet, its flow rate, etc.). For example, we can determine D c so that:

[0096] L r Vr i = A—— < i crit

[0097] D c 2g

[0098] With v cthe speed of the water in the pipe, to a coefficient depending on the roughness of the internal surface of the pipe and g the acceleration of gravity.

[0099] According to one embodiment of the invention, the overflow wall of at least one overflow basin may form a concave bowl, the opening of this overflow basin then being positioned at the bottom of the bowl or on one side of the bowl at a level lower than the upper section of the bowl which constitutes the overflow section. When this overflow basin is connected by a pipe to the separation means to which it is connected, the connection with the pipe corresponds to the position of the opening, either at the bottom of the concave bowl (at the lowest point of the concave bowl), or on one side of the bowl at a level lower than the upper section of the bowl. Thus, a progressive widening of the passage section is obtained from the pipe to the outlet of the overflow basin. This makes it possible to limit disturbances of the fluid, in particular turbulence.

[0100] For this embodiment, the water recovery device (unique for all the overflow basins of the system or the one associated exclusively with the overflow basin in question) can advantageously surround the wall of the concave bowl. Thus, the water which overflows all around the concave bowl can be recovered in the water recovery device while limiting the losses of produced water.

[0101] Additionally or alternatively, at least one overflow basin may be formed by a caisson, preferably parallelepipedal, comprising the overflow wall. In other words, one of the vertical walls of the caisson may form the overflow wall. The overflow wall has an upper level lower than the upper level of the other side walls of the caisson. In other words, the overflow wall has a height lower than the height of the other side walls of the caisson.

[0102] For example, one can have a catchment system with an overflow basin which has an overflow wall in the form of a concave bowl and another overflow basin which is in the form of a box with one of the walls forming the overflow wall.

[0103] The box can, for example, be a parallelepiped box made up of four vertical flat walls, one of which serves as an overflow wall.

[0104] When the overflow basin is formed by a box, the overflow wall of the box separates the overflow basin (on one side of the overflow wall) from the recovery device (on the other side of the overflow wall), which can advantageously be parallelepipedal to facilitate the manufacture of the system.

[0105] The overflow wall provides a seal between the overflow basin box and the water collection device. In other words, spring water can only pass from the overflow basin to the water collection device when the water height in the overflow basin is greater than the height of the overflow wall.

[0106] The opening (or the conduit if a conduit is connected to the overflow basin at the opening) through which the water enters the caisson may be provided by a lower wall (floor) of the caisson or by a side wall other than the overflow wall and at a level below the overflow section.

[0107] Advantageously, the system may comprise at least one adjustment means for adjusting the altitude (height) of the overflow section of at least one overflow basin (preferably, the system may comprise a separate adjustment means for adjusting the altitude of the overflow section of each overflow basin) at least at the time of installation of the catchment system. Indeed, at the time of installation of the system, it may be necessary to make some adjustments in order to verify that the system correctly produces the spring water in question and that it disturbs the hydrostatic pressure at the outlet of the spring in question as little as possible. Adjusting the altitude of the outlet (overflow section) of the overflow basin therefore makes it possible to improve the performance of the catchment system. The adjustment of the altitude may, for example, be carried out via an adjustment of the height of the pipe.

[0108] Preferably, the system may comprise at least one adjustment means for adjusting the height of the overflow section of at least one overflow basin (preferably the system may comprise a separate adjustment means for adjusting the height of the overflow section of each overflow basin) as a function of variations in flow rates and / or pressure and / or variation in density of the seawater or water of said source. By adjustable, it is meant that the height can be adjusted at different times during the operation of the source. To achieve this, the overflow pipe or basin may have a part of adjustable height, for example the overflow pipe or basin may comprise an extendable or retractable part which can be screwed or unscrewed or translated to adjust the height or may comprise an extendable or retractable part by means of a jack.The extendable or retractable part can at least slide longitudinally in the pipe to increase or reduce the (vertical) height of the pipe or the overflow basin.

[0109] According to a preferred embodiment of the invention, the vertical distance zc between the underwater outlet of the source considered (of each source) and the level (the altitude) of the overflow section of the overflow basin associated with the source considered can be determined by the following formula:

[0110] Pm ■ z s ■ 9 + p Zc = -

[0111] Ps- 9

[0112] With zs the depth of the underwater exit considered relative to sea level, p m the density of sea water and p sthe density of the water of said source considered, g the acceleration of gravity and Ap the predetermined overpressure value (greater than or equal to zero and preferably less than 100mbar) which is defined according to the characteristics of the source so that the flow rate of the source does not vary by more than 5%. zc thus corresponds to the height of the column of source water produced by the source considered so that the hydrostatic pressure at the outlet of the source considered is equal to the hydrostatic pressure of the seawater column at this level. Thus, with such a position of the outlet (overflow section) of the overflow basin associated with the source considered, the hydrostatic pressure is not or only slightly altered.

[0113] The adjustment of the height of the overflow section of the overflow basin at the time of installation mentioned above is particularly interesting, for example, if the water produced has a slightly different salinity from that of the source or if the separation means is not or not completely watertight, for example.

[0114] Adjusting the height of the outlet (overflow section) of the overflow basin at different times during operation, as mentioned above, is also particularly interesting if the salinity of the source water and / or the produced water changes over time and / or if the sea level changes (global warming, taking into account tides, for example).

[0115] The adjustment and / or setting then makes it possible to position the overflow section of the overflow basin at the altitude allowing the hydrostatic pressure to be maintained (or this pressure to be slightly altered) at the outlet of the underwater source.

[0116] Advantageously, the overflow section can have a constant level (a constant altitude) around the entire perimeter of the overflow wall so that the overflow altitude is well controlled.

[0117] According to one configuration of the invention, at least one water recovery device (preferably the single water recovery device or each water recovery device) may comprise a pump, such as a lifting pump, configured to be started when the water level in the recovery device in question exceeds a first predetermined threshold and configured to be stopped when the water level in the recovery device in question is below a second predetermined threshold, the second predetermined threshold being less than or equal to the first predetermined threshold. This pump thus functions as a lifting pump and is intended to supply water from the recovery device to a distribution network or to a storage means (for example placed on land, onshore or offshore, or at sea, preferably floating).

[0118] It is important to note that the pump of the recovery device is not used to convey water from the outlet of the underwater source to the overflow basin. This pump is used to evacuate water from the recovery device. Indeed, if such a pump were used, the hydrostatic pressure at the outlet of the source could be disturbed, which would be contrary to the effect sought by the invention.

[0119] The use of such a lifting pump allows automatic operation without human intervention. According to one implementation of the invention, the collection system may comprise a water storage means and a supply conduit for connecting the water recovery device to the storage means.

[0120] Thus, the recovery device is used to recover the water leaving the overflow basin and the water can be routed to a larger capacity storage facility, particularly remotely.

[0121] The storage facility can be placed on land, onshore or offshore, preferably on the coast for easy access.

[0122] By onshore, we mean that part of the storage means is fixed to the ground whose level is above sea level.

[0123] By offshore installation, we mean that part of the storage means is fixed to the ground whose level is below sea level and that at least a portion of the storage means is in contact with sea water.

[0124] Alternatively, the storage medium may be floating. For example, it may be a floating balloon that can be towed by boat. It may also be a floating tank anchored to the ground by cables (synthetic or metal) or chains, preferably by cables stretched to limit the movements of this floating tank.

[0125] For example, the storage medium can be a closed or semi-closed reservoir, a pond or an artificial lake (corresponding to open reservoirs).

[0126] The supply conduit may advantageously include a pump to convey the water from the recovery device to the storage means.

[0127] It is important to note that the pump in the supply conduit is not used to convey water from the outlet of the underwater source to the overflow basin but only to conduct water from the recovery device to the storage means. Indeed, if such a pump were used, the hydrostatic pressure at the outlet of the source could be disturbed in such a way that the flow rate would be reduced by more than 5%, or even completely stopped, which would be contrary to the effect sought by the invention.

[0128] The feed line pump may be a lift pump of the same type as that of the recovery device.

[0129] Storing water on land makes it easier to store water. In addition, the stored water is closer to its intended use and / or pre-treatment (possible desalination, fungicide treatment, bactericide treatment, etc.).

[0130] Preferably, the storage means, when floating, is capable of being disconnected from the supply conduit: in other words, the storage means comprises a means for connecting / disconnecting to the supply conduit. Thus, when the storage means is full, it can be disconnected from the supply conduit and towed by a boat to the shore. Another storage means can then be connected to the supply conduit to recover and store the produced water. Thus, there is little or no loss of produced water.

[0131] The supply conduit may be flexible to facilitate connection / disconnection operations to floating storage means.

[0132] Alternatively, the at least one recovery device (at least one device, each of the devices or the single device) may be placed on land, onshore or offshore, preferably on the coast to facilitate access.

[0133] Onshore installation means that part of the recovery device is fixed to the ground, the level of which is above sea level.

[0134] By offshore installation, we mean that part of the recovery device is fixed to the ground whose level is below sea level and at least a portion of the recovery device is in contact with sea water.

[0135] According to this variant where at least one recovery device is placed on land onshore or offshore, this recovery device may comprise an orifice to allow the introduction of water from an outlet of an additional water source, this orifice allowing the water from the additional water source to enter (penetrate), directly or indirectly, into the recovery device.

[0136] The additional water source may be underwater, i.e., its outlet level is below sea level, or terrestrial, i.e., its outlet level is above sea level. When the additional water source is underwater, the orifice in the recovery device is below the water level in that device. When the additional water source is terrestrial, the orifice in the recovery device may be above the water level in that device.

[0137] Preferably, the outlet of the additional water source may be opposite the orifice, so as to further simplify the system, the water source then preferably being on the coast, whether terrestrial or underwater.

[0138] Advantageously, the at least one recovery device (preferably the single recovery device or each recovery device) may comprise a control means in order to control the water level in this water recovery device when the orifice is below the water level in this recovery device, so that the pressure generated by the water height between the water level in this recovery device and the altitude of the outlet of the additional water source corresponds to the water pressure of the additional water source at its outlet. Thus, by guaranteeing such a level, the additional water source is not or only slightly disturbed by pressure variations induced by the capture system.The control means may comprise a lifting pump configured to be started when the water level in this recovery device exceeds a first predetermined threshold and configured to be stopped when the water level in this recovery device is below a second predetermined threshold, the second predetermined threshold being less than or equal to the first predetermined threshold. The pump may be connected to a float capable of monitoring the water level in this recovery device. When the float exceeds the first predetermined threshold, the pump is started, and when the float drops below the second predetermined threshold, the pump is stopped.

[0139] To ensure that the water level in this recovery device is well controlled, the first predetermined threshold and the second predetermined threshold may be close to each other. For example, they may be less than 10 cm apart and preferably they may be identical.

[0140] The use of such a lifting pump allows automatic operation without human intervention.

[0141] Alternatively, the recovery device may be floating. For example, it may be a floating tank surrounding the overflow basin. This recovery device may be anchored to the ground by cables (synthetic or metal) or by chains, preferably by cables stretched to limit the movements of this floating tank.

[0142] For example, the collection device can be a closed, semi-closed or open reservoir, a pond or an artificial lake (corresponding to open reservoirs).

[0143] By storing water in the onshore recovery device, it is easier to store water. In addition, the stored water is closer to its use and / or its pre-treatment (possible desalination, fungicide treatment, bactericide, etc.). As the overflow basin is in the immediate vicinity of the recovery device (either the recovery device surrounds the overflow basin or they are separated by an overflow wall, for example), a pipe connecting the separation means to the overflow basin may not be straight but follow a curved (incurved) line. Therefore, the pipe can advantageously be a flexible pipe.

[0144] According to a preferred configuration of the invention, the capture system can be configured to capture water from several underwater sources. The capture system can then comprise as many separation means as there are overflow basins as underwater sources, each separation means being connected to a separate overflow basin. Indeed, to capture water from each of the underwater sources, it is advantageous to have a separate separation means and a separate overflow basin for each source, so as to avoid disturbances from one source to the other.

[0145] In this configuration, the catchment system can include a single water recovery device to recover water from all overflow basins simultaneously. This simplifies downstream water treatment and limits infrastructure. Alternatively, the catchment system can include several water recovery devices. Each recovery device can be common to several overflow basins, for example, to recover water that has salinities or compositions close to each other in order to optimize treatment. Each recovery device can also be connected to a single overflow basin, so as not to mix the different waters.If the composition of water from a source diverges from its initial composition (for example, bacterial pollution, salinity level or chemical composition that varies), the use of a recovery device connected to a single overflow basin rather than to several basins, makes it possible to identify the source causing the defect more quickly, without having to stop the production of water from other sources.

[0146] The invention also relates to a method for capturing water from at least one underwater source. In this method, at least the following steps are carried out using the capture system as described above:

[0147] - The water from the at least one source (preferably from each source) is separated from the sea water at an underwater outlet, by the at least one separation means;

[0148] - The water (produced and from the underwater source) separated from the sea water is conveyed to the opening in the (each) overflow basin, preferably by a pipe (the length of which is possibly adjustable and preferably adjustable) connecting the separation means to the overflow basin;

[0149] - The speed of the water (from the source) in the overflow basin is slowed down by an overflow section of the overflow basin strictly greater than the section of passage of the water in the opening: this makes it possible to reduce the height of the jet of water leaving the overflow basin;

[0150] - The spring water contained in the overflow basin is overflowed through the overflow wall (whose outlet section is above sea level) and the spring water is recovered, by gravity, in the recovery device. This process operates without a pump, which avoids any disturbance of the hydrostatic pressure at the pump outlet, which could disrupt the flow of the spring and / or allow seawater to enter the collection system.

[0151] Preferably, the water from the water recovery device is conveyed, via a supply conduit, to a storage means which may be floating, placed onshore or offshore, and preferably placed on the coast to facilitate operations.

[0152] When water storage is coastal (onshore or offshore), it is as close as possible to the needs of populations, livestock and / or crops as well as as close as possible to water treatment plants before distribution (fungicide, bactericide and / or desalination treatment for example). In addition, water storage on land can be easily done via a natural or artificial pond for example. The supply pipe may include a pump to convey the water from the recovery bottom to the storage means but this pump is not used to raise the water from the source to the overflow basin.

[0153] When floating, the storage medium can be easily towed to be brought back to the shore where fresh water is needed.

[0154] Alternatively, water may be recovered from an additional water source directly into the (one of) the water recovery devices (or into a storage means) through an orifice in the recovery device (or into the storage means), the orifice advantageously being opposite the outlet of the second source. Water recovery may thus be improved by adding an additional water source.In this case, in order not to disturb (or to disturb only slightly) the hydrodynamic balance, the water level in the water recovery device (or in the storage means) can be controlled so that the pressure generated by the water height between the water level and the orifice corresponds to the pressure at the outlet of the additional water source or to the sum of the pressure at the outlet of the additional water source and a second predetermined overpressure value (dependent on the additional water source) capable of generating a variation in the flow rate of this source of less than 5%, in particular when the additional water source is underwater. To do this, it is possible to use, for example, a lifting pump already described, as well as a first and a second predetermined threshold.

[0155] According to one configuration of the invention, the water can be stored in a floating water recovery device, preferably anchored to the ground by taut cables.

[0156] Furthermore, according to an advantageous variant of this alternative, the water can be transferred from the floating recovery device to a mobile floating tank and the mobile floating tank can then be towed by a boat to land. Alternatively, several mobile floating recovery devices can also be provided. In this case, it is not necessary to transfer the water from the floating recovery device to a mobile floating tank. It is then sufficient to tow the mobile floating recovery device directly to land and connect another mobile floating recovery device to the collection system to recover the water.

[0157] Figure 1 illustrates, in a schematic and non-limiting manner, a first embodiment of a capture system according to the invention.

[0158] The capture system is used to produce water at outlet S1 from an underwater source. Thus, the underwater source flows into the seawater, at ground level 7 located below sea level 8.

[0159] The capture system comprises a separation means in the form of a weighted envelope 1 to be held on the ground 7 and so as to surround the outlet S1 of the underwater source.

[0160] The water from the underwater source has a lower salinity than sea water and preferably this water is fresh water (whose salinity is compatible with that of drinking water).

[0161] The collection system also comprises a pipe 3, for example a tubular pipe, connecting the casing 1 to the overflow basin 5. The pipe 3 is connected in a sealed manner to the casing 1 and to the overflow basin 5 to prevent any entry of sea water on the one hand and to prevent any loss of spring water on the other.

[0162] Thus, the water leaving the outlet S1 of the underwater source arrives in the separation means 1 then in the pipe 3 before reaching the overflow basin 5.

[0163] The overflow basin 5 is in the form of a concave bowl 30. The inlet section in the concave bowl 30 corresponds to the passage section in the pipe. By the shape of the concave bowl 30, the passage section of the water in the concave bowl 30 increases progressively up to the outlet section, corresponding to the section at the highest altitude, also called the overflow section. As a result, the speed of the water is reduced progressively, which makes it possible to limit the height of the water jet and to avoid disturbances which could be generated by a sudden increase in the passage section for example.

[0164] The concave bowl 30 forms an overflow wall: the water arriving in the overflow basin 5 is forced to pass over the concave bowl 30, forming the overflow wall, to overflow all around this concave bowl 30.

[0165] When the water passes over the concave bowl 30, it enters directly into the recovery device, here consisting of a recovery basin 4.

[0166] The recovery basin 4 surrounds the overflow basin 5 to collect the water which overflows all around the overflow basin 5. The recovery basin 4 is floating and anchored by taut cables 2 which are ballasted by weights 6.

[0167] Since the collection basin 4 is buoyant, it can slide vertically around the pipe 3 to essentially form a heaving motion. The pipe may be a rigid metal pipe, particularly steel, or a flexible pipe that allows more flexibility of movement for the floating collection basin 4. A sealing means is positioned at the interface between the collection basin 4 and the pipe 3.

[0168] Since the salinity of the spring water is lower than that of sea water, the level of the overflow section (outlet) of the overflow basin 5 is above the sea level 8, so that the pressure of the water column from the outlet S1 of the spring to the outlet section 99 of the overflow basin is equal to or substantially equal to the hydrostatic pressure of the sea water between the outlet S1 of the spring water and the sea level 8.

[0169] Figure 11 illustrates, in a schematic and non-limiting manner, a top view of the water collection system of Figure 1.

[0170] The water arrives in pipe 3 through the opening leading into the overflow basin, which here consists of a concave bowl 30. Thus the section of the opening is defined by the internal section of pipe 3, here cylindrical.

[0171] The water can then reach the concave bowl 30 where the water passage section increases. At the outlet of the concave bowl, at the overflow level, the section is the internal section of the concave bowl 30. This outlet section, or overflow section 9, is shown in the figure by the hatching in inclined continuous lines. It can thus be observed that this overflow section 9 is larger than the section of the opening.

[0172] Furthermore, when the water passes over the overflow wall formed by the concave bowl 30, it reaches the recovery device 4.

[0173] In the recovery device 4, the water passage section is delimited between the concave bowl 30 and the external wall of the water recovery device 4. In the figure, this section is shown by the area hatched by dots.

[0174] Figure 2 illustrates, in a schematic and non-limiting manner, several operating modes of the capture system according to the invention.

[0175] In these diagrams a), b), c) and d), the collection system comprises a separation means on which a non-return valve 10 is placed to prevent sea water from entering the collection system and to evacuate the potential surplus of spring water, a pipe and an overflow basin 5 with an overflow section level 9 of the overflow basin 5 as well as a recovery device in which the water 12 which has overflowed from the overflow basin is found.

[0176] In the left diagram a), the pressure at the spring outlet S1 is lower than that which would be generated by a column of water from the spring outlet S1 to the level of the outlet section 9 of the overflow basin 5. The water level 11 in the overflow basin 5 is therefore below the level of the overflow section 9 of the overflow basin 5. In this case, the flow rate of the spring is reversed. In other words, there is then a transfer of water from the catchment system to the spring. This operation could take place occasionally and only for a short time. The water column should then drop to a level close to sea level and remain filled with spring water. When the pressure has returned to its usual level, the catchment system will then fill with water again up to the overflow basin.

[0177] The non-return valve 10 is closed to prevent seawater from remaining in the collection system and in the source.

[0178] Diagram b) corresponds to an operation where the pressure of the source is equal or substantially equal to that which would be generated by a column of water from the outlet S1 of the source to the level of the overflow section 9 of the overflow basin 5. In this case, a low flow rate of the source occurs. The non-return valve 10 can then be kept closed. The flow rate of water produced then corresponds to the flow rate of the source.

[0179] Diagram c) corresponds to an operation where the source pressure is higher than that which would be generated by a column of water from the source outlet S1 to the level of the overflow section 9 of the overflow basin 5. In this case, a flow rate from the source greater than that of diagram b) occurs. If the flow rate is too high to pass into the collection system, the non-return valve 10 will be opened to allow the discharge of part of the source water into the sea water.

[0180] Preferably, the opening of this non-return valve can be controlled to maintain a substantially constant flow rate in the collection system. In other words, the non-return valve 10 will be opened more or less to control the flow rate.

[0181] Alternatively, the opening of this non-return valve 10 is not controlled but pressure-calibrated as explained previously in the description. In this case, the non-return valve 10 makes it possible to limit the pressure in the separation means, so as to tolerate a slight overpressure of predetermined value (of a few millibars, preferably less than 100 mbar) in the separation means, which makes it possible to guarantee a maximum flow rate.

[0182] Diagram d) corresponds to an operation where the pressure of the source is much higher than that which would be generated by a column of water from the outlet S1 of the source to the level of the overflow section 9 of the overflow basin 5. In this case, a flow rate of the source greater than that of diagram c) occurs and a jet of water 13 materialized by the dark gray arrow occurs above the overflow basin. As the flow rate is too strong to pass into the collection system, the non-return valve 10 is opened to the maximum opening to allow the evacuation of part of the source water into the sea water.

[0183] The height of the jet 13 can be limited by widening the water passage section between the pipe and the outlet section of the overflow basin 5.

[0184] Figure 3 illustrates, in a schematic and non-limiting manner, a second embodiment of the capture system according to the invention.

[0185] The capture system is used to produce water at outlet S1 from an underwater source. Thus, the underwater source flows into the seawater, at ground level 7 located below sea level 8.

[0186] The capture system comprises a weighted separation means to be held tightly on the ground 7 and so as to surround the outlet S1 of the underwater source.

[0187] The water from the underwater source has a lower salinity than sea water and preferably this water is fresh water (whose salinity is compatible with that of drinking water).

[0188] The collection system also comprises a pipe 3, for example a tubular pipe, connecting the separation means to an overflow basin of overflow section 9. The pipe 3 is connected in a sealed manner to the separation means and to the overflow basin 5 to prevent any entry of sea water on the one hand and to prevent any loss of spring water.

[0189] In addition, the level of the overflow section 9 of the overflow basin is adjustable by means of an extendable / retractable portion 14 which serves as an interface between the overflow basin and the pipe 3. As shown, the extendable / retractable portion 14 is a portion of the pipe 3 which can slide in the pipe 3 to allow the pipe 3 to be lengthened or shortened. Of course, to ensure sealing, a sealing means is positioned between the pipe 3 and the extendable / retractable portion 14.

[0190] Thanks to the extendable / retractable part 14, it is possible to modify the height Zc between the outlet S1 of the underwater source and the level of the outlet section 9 of the overflow basin and thus to adapt to variations in the parameters of the source, without generating (or generating little) hydrostatic disturbances.

[0191] Thus, the water leaving the S1 outlet of the underwater source arrives in the separation means then in pipe 3 before reaching the overflow basin.

[0192] The overflow basin is in the form of a concave bowl identical to that of Figure 1. The concave bowl forms an overflow wall: the water arriving in the overflow basin is forced to pass over the concave bowl, forming the overflow wall, to overflow all around this concave bowl.

[0193] As the water passes over the concave bowl, it enters directly into the collection device, here consisting of a collection basin 4.

[0194] The recovery basin 4 surrounds the overflow basin to collect the water that overflows all around the overflow basin.

[0195] The recovery basin 4 is floating and anchored by tensioned cables 2 which are weighted by KG weights.

[0196] Since the collection basin 4 is buoyant, it can slide vertically around the pipe 3 to essentially form a heaving motion. The pipe 3 may be a rigid pipe made of metal, particularly steel, or a flexible pipe that allows more flexibility of movement for the floating collection basin 4. A sealing means is positioned at the interface between the collection basin 4 and the pipe 3.

[0197] Since the salinity of the spring water is lower than that of sea water, the level of the overflow section 9 of the overflow basin is above the sea level 8, so that the pressure of the water column of the outlet S1 of the spring at the level of the overflow section of the overflow basin 9 is equal or substantially equal to the hydrostatic pressure of the sea water over the height Z s between the S1 outlet of the spring water at sea level 8.

[0198] The collection system also comprises a supply conduit 15 equipped with a pump 16 for conveying water from the recovery device 4 to the mobile floating tank 20.

[0199] When the mobile floating tank 20 is full, it is towed by a boat to the shore and another mobile floating tank 20 is then connected to the supply conduit 15.

[0200] Thus, the mobile floating tanks are able to be connected and disconnected from the supply conduit 15.

[0201] Figure 4 illustrates, in a schematic and non-limiting manner, a third embodiment of the capture system according to the invention.

[0202] The capture system is used to produce water at outlet S1 from an underwater source. Thus, the underwater source flows into the seawater, at ground level 7 located below sea level 8.

[0203] The capture system comprises a weighted separation means to be held in a sealed manner on the ground 7 and so as to surround the outlet S1 of the underwater source. The water from the underwater source has a lower salinity than that of sea water and preferably, this water is fresh water (whose salinity is compatible with that of drinking water).

[0204] The collection system also comprises a pipe 3, for example a tubular pipe, connecting the separation means to an overflow basin of overflow section 9. The pipe 3 is connected in a sealed manner to the separation means and to the overflow basin to prevent any entry of sea water on the one hand and to prevent any loss of spring water on the other.

[0205] In addition, the level of the overflow section 9 of the overflow basin is adjustable by means of an extendable / retractable portion 14 which serves as an interface between the overflow basin and the pipe 3. As shown, the extendable / retractable portion 14 is a portion of the pipe 3 which can slide in the pipe 3 to allow the pipe 3 to be lengthened or shortened. Of course, to ensure sealing, a sealing means is positioned between the pipe 3 and the extendable / retractable portion 14.

[0206] Thanks to the extendable / retractable part 14, it is possible to modify the height Zc between the outlet S1 of the underwater source and the level of the outlet section 9 of the overflow basin and thus to adapt to variations in the parameters of the source, without generating (or generating little) hydrostatic disturbances.

[0207] Thus, the water leaving the S1 outlet of the underwater source arrives in the separation means then in pipe 3 before reaching the overflow basin.

[0208] The overflow basin is in the form of a concave bowl identical to that of Figure 1. The concave bowl forms an overflow wall: the water arriving in the overflow basin is forced to pass over the concave bowl, forming the overflow wall, to overflow all around this concave bowl.

[0209] As the water passes over the concave bowl, it enters directly into the collection device, here consisting of a collection basin 4.

[0210] The recovery basin 4 surrounds the overflow basin to collect the water that overflows all around the overflow basin.

[0211] The recovery basin 4 is floating and anchored by taut cables which are weighted by KG weights.

[0212] Since the collection basin 4 is buoyant, it can slide vertically around the pipe 3 to essentially form a heaving motion. The pipe 3 may be a rigid pipe made of metal, particularly steel, or a flexible pipe that allows more flexibility of movement for the floating collection basin 4. A sealing means is positioned at the interface between the collection basin 4 and the pipe 3.

[0213] Since the salinity of the spring water is lower than that of sea water, the level of the overflow section 9 of the overflow basin is above the sea level 8, so that the pressure of the water column of the outlet S1 of the spring at the level of the overflow section 9 of the overflow basin is equal or substantially equal to the hydrostatic pressure of the sea water over the height Z s between the S1 outlet of the spring water at sea level 8.

[0214] The collection system also includes a supply conduit 15 equipped with a pump 16 to convey the water from the recovery basin 4 to the onshore coastal reservoir (placed on the ground onshore near the coast) 21.

[0215] The terrestrial coastal reservoir can be an artificial reservoir or a natural area such as a lake or pond.

[0216] In Figures 1, 3, and 4, the pipe 3 is preferably rigid, elongated, and vertical to simplify the collection system and make it more compact. The collection systems in these figures relate to the collection of a single underwater water and therefore only include a single separation means, a single overflow means, and a single water recovery device.

[0217] Figure 5 illustrates, in a schematic and non-limiting manner, a fourth embodiment of the capture system according to the invention.

[0218] The catchment system is used to produce water at outlet S1 from an underwater source. Thus, the underwater outlet S1 discharges into the seawater, at ground level below sea level 8. The underwater outlet S1 could nevertheless exit on the coast at an altitude below sea level but above the sea floor.

[0219] The capture system comprises a separation means 1 weighted to be held in a sealed manner on the ground 7 and so as to surround the outlet S1 of the underwater source.

[0220] The water from the underwater source has a lower salinity than sea water and preferably this water is fresh water (whose salinity is compatible with that of drinking water).

[0221] The collection system also comprises a pipe 3, for example a tubular pipe, connecting the separation means 1 to an overflow basin 5 with an overflow section 9. The pipe 3 is connected in a sealed manner to the separation means 1 and to the overflow basin 5 to prevent any entry of sea water on the one hand and to prevent any loss of spring water on the other. The pipe 3 is flexible here.

[0222] In addition, the level of the overflow section 9 of the overflow basin 5 is adjustable by means of an extendable / retractable part 14 which serves as an interface between the overflow basin 5 and the pipe 3. As shown, the extendable / retractable part 14 is a part of the pipe 3 which can slide in the pipe 3 to allow the pipe 3 to be lengthened or shortened. Of course, to ensure sealing, a sealing means is positioned between the pipe 3 and the extendable / retractable part 14. Thanks to the extendable / retractable part 14, it is possible to modify the height Zc1 between the outlet S1 of the underwater source and the level of the overflow section 9 of the overflow basin and thereby adapt to variations in the parameters of the outlet source S1, without generating (or generating little) hydrostatic disturbance.

[0223] Thus, the water leaving the outlet S1 of the underwater source arrives in the separation means 1 then in the pipe 3 before reaching the overflow basin 5.

[0224] The overflow basin 5 is in the form of a concave bowl identical to that of figure 1.

[0225] The concave bowl forms an overflow wall: the water arriving in the overflow basin 5 is forced to pass over the concave bowl, forming the overflow wall, to overflow all around this concave bowl.

[0226] As the water passes over the concave bowl, it enters directly into the collection device, here consisting of a collection basin 4.

[0227] The recovery basin 4 surrounds the overflow basin 5 to collect the water that overflows all around the overflow basin 5.

[0228] Recovery basin 4 is placed on the coast here offshore since part of recovery basin 4 is below sea level 8.

[0229] Recovery basin 4 includes an orifice opposite the outlet S2 of an additional water source. The outlet S2 of the additional water source is coastal. Here it is located at an altitude below sea level 8, which is why recovery basin 4 is offshore. If the outlet S2 of the second source were above sea level, recovery basin 4 could be onshore or offshore.

[0230] The height Zc2 between the water level in the recovery basin 4 and the outlet S2 of the additional water source (or the orifice of the recovery basin 4) is controlled so as not to disturb (or to disturb little) the hydrostatic balance of the additional water source.

[0231] The water level in the recovery basin 4 is controlled so that the pressure of the water column of height Zc2 is equal or substantially equal to the hydrostatic pressure of the seawater column between the outlet S2 of the additional water source and the sea level 8.

[0232] Figure 6 illustrates, in a schematic and non-limiting manner, a fifth embodiment of the capture system according to the invention.

[0233] The capture system is used to produce water at outlet S1 from a first underwater source and to produce water at outlet S3 from another underwater source (water could also be produced from other additional underwater sources). Thus, the first underwater source opens through outlet S1 into the seawater, at ground level 7 located below sea level 8 while the source exiting through outlet S3 is an underwater coastal source. The underwater outlet S1 could nevertheless exit on the coast at an altitude below sea level but above the seabed.

[0234] The capture system comprises two separation means 1, one being weighted to be held in a sealed manner on the ground 7 so as to surround the outlet S1 of the underwater source and the other being held around the outlet S3 of the other source.

[0235] Each of the two separation means 1 serves to isolate the water from each source from the surrounding seawater.

[0236] The spring waters leaving through outlets S1 and S3 have lower salinities than sea water and preferably, these waters are fresh waters (whose salinity is compatible with that of drinking water).

[0237] Each separation means 1 is connected to a pipe 3, for example a tubular pipe, connecting a separation means 1 to a separate overflow basin 5 with an overflow section 9 (corresponding to the outlet section at the upper level of the overflow wall). Each pipe 3 is connected in a sealed manner to a separate separation means 1 and a separate overflow basin 5 to prevent any entry of sea water on the one hand and to prevent any loss of spring water. Each pipe 3 is here flexible to move the overflow basins and the water recovery device to the coast.

[0238] In addition, the level of the overflow section 9 of each overflow basin 5 is adjustable by means of an extendable / retractable portion 14 which serves as an interface between the overflow basin 5 in question and the pipe 3 to which it is connected. As shown, the extendable / retractable portion 14 is a portion of the pipe 3 which can slide in the pipe 3 to allow the pipe 3 to be lengthened or shortened. Of course, to ensure sealing, a sealing means is positioned between the pipe 3 and the extendable / retractable portion 14.

[0239] Thanks to the extendable / retractable part 14, it is possible to modify the heights Zc1 and Zc3 respectively between the outlet S1 of the underwater source and the level of the overflow section 9 of the overflow basin 5 associated with the outlet source S1 and between the outlet S3 of the other underwater source and the level of the overflow section 9 of the overflow basin 5 associated with the outlet source S3, and in fact, to adapt to the variations in the parameters of each source, without generating (or generating little) hydrostatic disturbances.

[0240] Thus, the water leaving each of the outlet sources S1 and S3 arrives in one of the separation means 1 then in a pipe 3 before reaching one of the overflow basins 5. The overflow basins 5 are in the form of concave bowls identical to that of Figure 1 but they can take other forms without departing from the scope of the invention. The concave bowls of the two overflow means 5 form overflow walls: the water arriving in each overflow basin 5 is forced to pass over the concave bowl, forming the overflow wall, to overflow all around this concave bowl. When the water passes over the concave bowl, it enters directly into the recovery device, consisting here of a recovery basin 4 which is here common to the two overflow basins 5. Thus, the collection system here comprises a single recovery device 4.

[0241] The recovery basin 4 surrounds the two overflow basins 5 to collect the water which overflows all around the overflow basins 5.

[0242] Recovery basin 4 is placed on the coast here offshore since part of recovery basin 4 is below sea level 8.

[0243] As illustrated, the overflow sections 9 of the two overflow basins are located at different altitudes and are a function of the salinities and outlet depths of the two sources. Similarly, the passage section in the concave bowls, at the inlet and outlet, and the passage section in the pipe, differ depending on the sources, in particular their flow rates and pressures.

[0244] The water level in the recovery basin 4 is maintained below the overflow levels 9 of the two overflow basins 5.

[0245] Figure 7 illustrates, in a schematic and non-limiting manner, the principle of a lifting pump in the recovery basin 4.

[0246] The collection system comprises a pipe 3, an overflow basin 5, a recovery basin 4 and an expandable / retractable part 14 at the interface between the pipe 3 and the overflow basin 5.

[0247] To reach the recovery basin 4, the water must pass over the wall of the overflow basin 5 formed here by the concave bowl.

[0248] Once the water reaches the collection basin 4, the water can be conveyed via the supply line 15 to a distribution network, a water treatment plant or a storage reservoir.

[0249] A lifting pump 24 is installed in the lower part of the recovery basin 4 at the inlet of the supply pipe 15.

[0250] When the water level N in the recovery basin 4 reaches the level Nmax, the lifting pump 24 is started and the water is then discharged into the supply pipe 15.

[0251] When the water level N in the recovery basin 4 reaches the level Nmin (located above the pump so as to keep the pump submerged), the lifting pump 24 is stopped so that a minimum water level is respected in the recovery basin and the lifting pump does not operate too quickly, which would risk damaging it.

[0252] To know the water level N in the recovery basin 4, the lifting pump 24 can be connected to a float 22 which follows the water level in the recovery basin 4. The float can be connected to the lifting pump 24 by a cable 23. Thus, the water level in the recovery basin can be known and the lifting pump can be controlled automatically according to this level N.

[0253] The principle described in the recovery basin can also be applied in a similar way in a water storage means, the water then being sent through the pipe to a distribution network, a water treatment plant or to another means of water storage.

[0254] Figure 8 illustrates, in a schematic and non-limiting manner, a slight variant of the invention in which once the water has passed through the pipe 3 to reach the overflow basin 5, in the form of a concave bowl and has reached its overflow section 9, a guide means 50 is positioned at the outlet of the overflow basin to accompany the water and move it away from the wall of the overflow basin 5. The guide means takes the form of a convex wall so that the water falls in drops without flowing along the wall of the overflow basin 5. This allows better evacuation of the water towards the water recovery device (not shown in the figure but surrounding the concave bowl of the overflow basin).

[0255] Figure 9 illustrates, in a schematic and non-limiting manner, a sixth embodiment of the capture system according to the invention.

[0256] The catchment system is used to produce water at outlet S1 from an underwater spring. Thus, the underwater spring discharges into the seawater, at ground level below sea level. The underwater outlet S1 could nevertheless exit on the coast at an altitude below sea level 8 but above the sea floor.

[0257] The capture system comprises a separation means 1 weighted to be held in a sealed manner on the ground 7 and so as to surround the outlet S1 of the underwater source. The water from the underwater source has a lower salinity than that of sea water and preferably, this water is fresh water (whose salinity is compatible with that of drinking water).

[0258] The collection system also comprises a pipe 3, for example a tubular pipe, connecting the separation means 1 to an overflow basin 5 with an overflow section 9. The pipe 3 is connected in a sealed manner to the separation means 1 and to the overflow basin 5 to prevent any entry of sea water on the one hand and to prevent any loss of spring water on the other. The pipe 3 is flexible here.

[0259] The overflow basin 5 is here a box with an overflow wall 51 which is one of the side walls of the box.

[0260] In addition, the level of the overflow section 9 of the overflow basin 5 is adjustable by means of an extendable / retractable part 14 which is part of the overflow wall 51.

[0261] Thanks to the extendable / retractable part 14, it is possible to modify the height Zc1 between the outlet S1 of the underwater source and the level of the overflow section 9 of the overflow basin 5 and therefore to adapt to variations in the parameters of the outlet source S1, without generating (or generating little) hydrostatic disturbances.

[0262] Thus, the water leaving the outlet S1 of the underwater source arrives in the separation means 1 then in the pipe 3 before reaching the overflow basin 5 in the form of a box.

[0263] When the overflow basin 5 is filled, the water passes over the overflow wall 51 to enter, by gravity, the water recovery device 4 which is separated from the overflow basin 5 by the overflow wall 51.

[0264] A pump 24 may be installed in the water recovery device 4 to convey the water to a treatment plant or to a distribution network for example. This pump 24 may be a lifting pump whose operation has been described previously.

[0265] Recovery basin 4 is placed on the coast here offshore since part of recovery basin 4 is below sea level 8.

[0266] The capture system also comprises a separation means for separating the water from a second underwater source S2 and a second overflow means 5. This separation means may consist of a seal surrounding the source S2 between the coastal rock wall and the overflow basin in the form of a box, the seal may be ensured for example by a mortar or other sealing means. The second overflow means 5 is in the form of a box, a side wall of which forms the overflow wall 51. The overflow basin 5 comprises an opening opposite the second (pipeless) outlet source S2. The outlet of the second source S2 is coastal. It is located here at an altitude below sea level 8, which is why the recovery basin 4 is offshore.

[0267] Thus, the water leaving the outlet S2 of the underwater source arrives in the separation means and then directly in the overflow basin 5 in the form of a box. When the overflow basin 5 is filled, the water passes over the overflow wall 51 to enter, by gravity, the water recovery device 4 which is separated from the overflow basin 5 by the overflow wall 51.

[0268] The recovery basin 4 is common to the two overflow basins 5: it recovers the water from these two overflow basins 5.

[0269] The height Zc2 between the overflow section 9 of the second overflow means 5 and the outlet S2 of the second source is controlled so as not to disturb (or to disturb only slightly) the hydrostatic balance of the second outlet source S2.

[0270] The water level in the recovery basin 4 is controlled so that it is maintained below the level of the lowest overflow section, the two overflow sections not necessarily being at the same level and presumably they are at different levels.

[0271] Figure 10 illustrates, in a schematic and non-limiting manner, a seventh embodiment of a capture system according to the invention.

[0272] The figure on the left is a front view while the view on the right is a side view of the same system.

[0273] The catchment system includes several overflow basins 140 (here six overflow basins) in the form of parallelepiped boxes to facilitate the arrangement of the boxes.

[0274] Each overflow basin 140 comprises an opening A1, A2, A3, A4, A5, A6 for the entry of water from a separate source. Each overflow basin 140 is connected, via these openings A1, A2, A3, A4, A5, A6, to a separation means (not shown) directly or indirectly via a pipe, the separation means surrounding each source separately.

[0275] As shown in the figures, the openings A1, A2, A3, A4, A5, A6 each arrive on a side wall of each box (side wall opposite the overflow wall 130), in the lower part of the side wall (and below the overflow section 135). However, these openings could arrive on the lower wall of the box, like the opening A3b shown for illustrative purposes.

[0276] When the water reaches the overflow section 135 whose level corresponds to the upper level of the overflow wall 130 of each box, the water passes over the overflow wall 130 to reach the water recovery device 150 which is here common to all the overflow basins. According to alternatives, several water recovery devices 150 could be used by being exclusively used for a single overflow basin (in this case, there would be as many water recovery devices as there are overflow basins) or could be common to several overflow basins (for waters of very close salinity or close minerality for example).As shown, the collection system comprises a single parallelepiped water recovery device 150 whose maximum water level 120 is maintained below the level of the lowest overflow wall (in this case the overflow wall corresponding to the source entering through the opening A1 in the diagram).

[0277] The water recovery device 150 also includes an orifice 01 for recovering water from another additional source. This orifice 01 is located above the maximum water level 120 in the water recovery device 150. This orifice 01 is suitable for onshore sources whose outlet is located above sea level.

[0278] Thus, the capture system may comprise an enclosure 100. The enclosure 100, for example here parallelepiped, comprises the various overflow means 140 and the water recovery device(s) 150.

[0279] The water recovery device 150 comprises a pipe 15 for supplying a distribution network and / or a water treatment plant. This pipe comprises a pump 24 which is a lifting pump. A float 22 is connected to the pump 24 by a cable 23 so as to monitor the water level in the water recovery device 150. When the water level in the water recovery device 150 reaches a first predetermined threshold, the pump 24 is started to evacuate the water; when the water level in the water recovery device 150 reaches a second predetermined threshold, below or equal to the first threshold, the pump is stopped to maintain a sufficient water level in the water recovery device 150 so as in particular to ensure that the pump remains submerged to avoid loss of priming on the one hand and to prevent it from operating too quickly, which could damage it.

[0280] As can be seen in the diagram on the left, the parallelepiped boxes of the overflow basins 140 are not identical, on the one hand because the height of the overflow walls is different for each overflow basin 140 and on the other hand because the widths of the boxes, such as the widths L2, L3 and L4, can vary. These widths can in particular vary depending on the nominal flow rates of the different sources.

[0281] The boxes of the overflow basins 140 are each separated from the water recovery device 150 by an overflow wall 130.

[0282] The side walls 110 of the boxes of the overflow basins 140, other than the overflow wall 130, rise to the upper level 160 (the ceiling) of the enclosure 100, so that the water from one overflow basin 140 cannot pass into another overflow basin 140 by passing over a side wall 110.

[0283] According to an alternative where the enclosure would not have a ceiling, the side walls 110 of the boxes of the overflow basins 140, other than the overflow wall 130, rise to a certain defined level higher than that of all the overflow walls.

[0284] With the arrangement of the various overflow basins 140 and the water recovery device(s) 150 in an enclosure 100, the footprint of the capture system is reduced, which is beneficial for the environment. In addition, more flexibility can be provided in the design and manufacture of the system.

[0285] In the illustration of Figure 10, all the overflow basins 140 are positioned on one and the same side of the water recovery device 150 but of course, the overflow basins 140 could be placed on two, three or four sides of the parallelepiped water recovery device. If the boxes of the overflow basins and / or the water recovery device(s) are not parallelepiped, other arrangements of these elements in an enclosure could of course be envisaged.

[0286] Figure 12 illustrates, in a schematic and non-limiting manner, a top view of a collection system where the overflow basin 5 is formed by a box, here parallelepiped. The box comprises an overflow wall 130 which separates the overflow basin 5 from the recovery device 4.

[0287] The water arrives at the bottom of the overflow basin box 5 at the opening via pipe 3.

[0288] The section of the opening through which the water arrives from pipe 3 is thus delimited by the internal section of pipe 3, here cylindrical.

[0289] The overflow section 9 is delimited by the walls of the overflow basin 5, including the overflow wall 130. It can thus be observed that this overflow section 9 is larger than the section at the level of the opening corresponding to the internal section of the pipe 3. This overflow section 9 is shown in the figure by the hatching in continuous inclined lines.

[0290] Furthermore, when the water overflows and reaches the water recovery device 4, the water is in the section delimited by the walls of the water recovery device 4, including the overflow wall 130. This section is shown in the figure by the area hatched by dots.

Claims

Demands 1. A water intake system from at least one submarine water source comprising at least one separation means (1) for separating the water from the at least one source from seawater, each separation means (1) being connected to a separate overflow basin (5), each overflow basin (5) comprising an opening (A1, A2, A3, A4, A5, A6) for the inlet of water from the at least one source, the intake system comprising at least one water recovery device (4, 150), each overflow basin (5) comprising an overflow wall (51, 130) configured so that the water from the at least one source passes over said overflow wall (51, 130) to enter, by gravity, into the at least one recovery device (4, 150), characterized in that within each overflow basin (5), the overflow section (9, 135) of said overflow basin (5) is strictly greater than the section of said opening (A1, A2, A3, A4, A5,A6) said overflow basin (5), and in that the overflow section (9, 135) of the overflow basin is situated strictly above sea level (8).

2. Water collection system from at least one underwater water source according to claim 1, wherein each separation means (1) is connected to the opening (A1, A2, A3, A4, A5, A6) of the overflow basin (5) by a pipe (3), the water passage cross-section in each pipe (3) being strictly less than the maximum water passage cross-section in the separation means (1) to which the pipe (3) is connected and in the maximum water passage cross-section in the overflow basin (5) to which the pipe (3) is connected.

3. A system for capturing water from an underwater water source according to any one of the preceding claims, wherein at least one separation means (1) comprises a casing, preferably a flexible casing.

4. Water collection system from at least one underwater water source according to any one of the preceding claims, wherein the at least one separation means (1) comprises at least one check valve (10) capable of allowing water from said source to pass outside the separation means (1) and preventing seawater from passing into the separation means (1).

5. Water capture system from at least one underwater water source according to any one of the preceding claims, wherein said overflow wall (51, 130) of at least one overflow basin (5) has the shape of a concave bowl (30), the opening of this at least one overflow basin (5) being positioned at the level of the bottom of the concave bowl (30), and preferably, the recovery device (4) surrounding the concave bowl (30). a method for capturing at least one underwater water source according to any one of claims 1 to 4, wherein at least one overflow basin (5) is formed by a caisson comprising the overflow wall (130), the overflow wall (130) separating the overflow basin (5) on one side of the overflow wall (130) from the recovery device (4) on the other side of the overflow wall (130).Water intake system from at least one submarine water source according to any one of the preceding claims, wherein the system comprises an adjustment means for adjusting the overflow section altitude (9, 135) of at least one overflow basin (5) at least at the time of installation of the intake system, preferably, the system comprises an adjustment means for adjusting the overflow section altitude (9, 135) of at least one overflow basin (5) according to variations in flow rates and / or pressure and / or density variation of the seawater or the water from at least one source. Water intake system from at least one submarine water source according to any one of the preceding claims, wherein the vertical distance zc between the outlet of each submarine source and the level of the overflow section (9, 135) of each overflow basin (5) to which said outlet is connected is determined by the following formula: Pm ■ Zs ■ 9 + PZ c Ps-9 With zs the depth of the outlet (S1, S2, S3) of the considered underwater source relative to sea level (8), g the acceleration due to gravity, Ap a predetermined overpressure value greater than or equal to zero and defined according to the characteristics of the considered source, p m the density of seawater and p sthe density of the water from said underwater source considered. Water intake system from at least one underwater water source according to any one of the preceding claims, wherein the at least one recovery device (4) comprises a pump (24) configured to start when the water level in the recovery device (4) exceeds a first predetermined threshold and configured to stop when the water level is below a second predetermined threshold, the second predetermined threshold being less than or equal to the first predetermined threshold. Water intake system from at least one underwater water source according to any one of the preceding claims, wherein the intake system comprises a water storage means and a supply conduit (15) connecting the at least one water recovery device (4) to the storage means, the storage means being floating, and preferably able to be disconnected from the supply conduit, or laid on the ground. Water collection system from at least one underwater water source according to one of the preceding claims, wherein at least one water recovery device (4) is floating and anchored to the ground by cables, preferably by tensioned cables, or laid on the ground onshore or offshore.A water collection system from at least one underwater water source according to any one of the preceding claims, wherein the at least one water collection device (4) comprises an orifice for allowing the introduction of water from an outlet (S2) of an additional water source, the orifice allowing water from said additional water source (S2) to enter the at least one water collection device (4) directly or indirectly, the at least one collection device (4) preferably comprising a control means for controlling the water level in the at least one water collection device when the orifice is below the water level.A water intake system from at least one underwater water source according to any one of the preceding claims, wherein the intake system is configured to capture water from several underwater sources, said intake system comprising as many separation means (1) and overflow basins (5) as there are sources, each separation means (1) being connected to a separate overflow basin (5), preferably the intake system comprising a single water recovery device (4) for recovering water from all the overflow basins. A method for capturing water from at least one underwater water source, wherein at least the following steps are carried out using the intake system according to any one of claims 1 to 13: - The water from at least one source is separated from the seawater at the level of an underwater outlet, by at least one means of separation (1); - The water separated from the seawater is conveyed to the opening (A1, A2, A3, A4, A5, A6) in the overflow basin (5); - The speed of the water in the overflow basin (5) is slowed down by means of an overflow section (9, 135) of the overflow basin (5) strictly greater than the water passage section in the opening (A1 , A2, A3, A4, A5, A6); - The water is overflowed from the overflow basin (5) and collected by gravity in the recovery device (4), the recovery device (4) being floating or placed on the ground, onshore or offshore, and preferably, it is transferred water from the water recovery device (4) is transferred to a floating storage means and the floating water storage means is towed by a boat to land.