LU101278A1 - Rainwater tank - Google Patents

Abstract

The tank has an inner wall of porous concrete (8) to define a storage space (3.30) and a buffer space (9,90,91). The inner wall is made of draining concrete with a maximum water permeability of 0.05 liter / m2 / s to 5 liters / m2 / s inclusive, preferably from 0.1 liters / m2 / s to 3 liters / m2 / s included, water permeability being measured in the case of storage space almost filled with water (3).

Description

The invention relates to a water buffer system, in particular a rainwater buffer tank.

More and more houses and other buildings are equipped with water tanks to store rainwater. If water consumption is insufficient, the water tanks remain practically full of water and, in the event of heavy precipitation, they do not offer a solution against excessive discharge of water into watercourses.

A system which assembles plastic modules using a porous textile material is known to remedy the problems of thunderstorms. The construction of such a system requires underground work to obtain sufficient soil stability. An upper layer is also required to allow circulation over it.

Water tanks which can also be used as drainage systems are for example described in document WO95 / 16833. The drainage system according to this document uses perforated walls and a porous textile material to define a storage volume, the water flowing through the walls and porous textile material in order to allow the infiltration of the in the basement.

Such a system requires earthworks to be certain that the walls with the porous textile material are surrounded by a layer of porous soil. Furthermore, in the case of wet soils, such systems are completely ineffective. In fact, the groundwater will flow through the porous side walls into the tank, thus limiting the space for the storage of rainwater.

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The use of porous concrete layers is known for driveways, roads and parking lots. Porous concrete, which has a very high permeability, is intended to convey water to a lower layer of the soil. As soon as this layer of soil is wet, the effectiveness of porous concrete is reduced.

Document DE9412053U1 describes a water tank which is provided with a filter element and with a flow opening situated at a level higher than the filter element. The filter element therefore does not act as a means to control the evacuation of rainwater.

Document US2012 / 0111428 describes a water tank manufactured in HDPE for the collection of rainwater, the water tank being provided with a filter structure with a filter sheet to retain the solid particles from a diameter of 20 μm. Such a filter does not work as a means to control the evacuation of rainwater.

Document DE10231241 describes a filtering element made of porous concrete. Water flows from bottom to top through porous concrete. In addition, as soon as there is too much rain water, the solid particles settle on the horizontal filter element so that the evacuation of rain water cannot be controlled.

Document DE4338085 describes a filtering installation with horizontal filtering elements for filtering rainwater. Such an installation does not function as a means of controlling the evacuation of rainwater from the tank.

All these known systems do not offer an effective solution for controlling the evacuation of rainwater to streams or rivers during a period of rain and afterwards, for example in the case where the soil is already too wet.

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The invention relates to a water buffer system for the storage of rainwater / water. With the buffer system according to the invention, the provision of a layer of porous soil all around the water tank is no longer necessary. The discharge of rainwater does not depend on the layer of soil in which the water tank is placed. By effectively regulating the evacuation of rainwater by means of one or more buffer systems according to the invention, it is possible to regulate the flow of water flowing to rivers, ditches, streams, floodplains, etc. The water buffer systems according to the invention can also be used as a means for regulating the level of water in canals, ditches, rivers, etc.

For example, the water buffer systems according to the invention can be used along dikes, dams, towpaths or inspection channels for canals, ditches, streams, rivers, etc. (and / or part of them) to regulate the water level, at least partially.

If necessary, the vertical inner wall of porous concrete can be cleaned easily.

The buffer system according to the invention comprises at least one buffer tank (T) for the collection and storage (at least temporarily) of rainwater / water and for a controlled evacuation of water. The water tank of the buffer system according to the invention comprises at least:

- one or more external walls (1) which are made from non-porous concrete and define an internal volume (2), part of which acts as a storage space (3) for rainwater / water with storage volume for rainwater / water;

- an intake opening (4) through which rainwater / water can flow into the storage space (3);

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- a drainage opening (5) for the evacuation of rainwater / water outside the water tank (T);

- a cover (6) with a manhole (7); and

- a control system (5.8) to control the flow of rainwater / water out of the water tank (T).

According to the invention, the control system (5,8) consists of at least one or more vertical internal walls of porous concrete (8) which extend into the internal volume (2) of the water tank ( T) and which divides (s) this interior volume at least into a storage space (3) for rainwater / water and a buffer space (9) with a buffer volume for collecting the water which flows through the interior wall or walls of porous concrete (8).

The buffer space (9) is provided with the drainage opening (5) for the evacuation of rainwater / water, while the vertical interior wall or walls made of porous concrete (8) are made of hardened draining concrete made by hardening a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water to obtain an open pore volume of 8 to 12% included in hardened porous draining concrete, hardened porous draining concrete having a water permeability of 0.05 liter / m ² / s to 5 liters / m ² / s, preferably 0.1 liter / m ² / s to 3 liters / m ² / s included and, more particularly, between 0.1 liter / m ² / s and 1 liter / m ² / s (like 0.1; 0.2; 0.4; 0.5; 0 , 7; 0.8 and 1 liter / m ² / s), this water permeability being measured for a storage space almost completely filled with water (3) and a substantially empty buffer space (9).

Specific features and characteristics of advantageous variants of the buffer system according to the invention or of the water tank of the buffer system according to the invention are one or more of the following:

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- the water tank (T) has a height of less than 3 m, preferably between 1 and 2.5 m;

- in its first variant (fig. 1), the total water discharge capacity varies linearly with the height of water present between 0% and 100%;

in a second variant, the total water discharge capacity measured for a water height equal to half the storage space and, preferably, at a water height of 0, 3 m is equal to 80% to 100% inclusive, preferably 90% to 100% inclusive of that measured in the case of storage space almost completely filled with water (3) and a substantially empty buffer space (9 );

- the hardened porous draining concrete has one or more zones having a higher permeability to water compared to the average water permeability of the hardened porous draining concrete, this or these zones (10) being situated at a height (h ) from the bottom (3B) of the storage space (3) which is less than 50 cm, and preferably less than 30 cm. In this way, it is easier to regulate the drainage of rainwater.

In case of normal precipitation intensity, the water flowing in the water tank is evacuated with minimal delay towards the stream. In this case, the storage space is only partially used. In the event of heavy rain showers, the storage space and the buffer space are almost full. The flow of water which is discharged to the stream is practically limited by the passage of the outlet opening (5). The storage space acts as the first means to regulate / regulate the flow of rainwater to the stream, ditch, canal, river, etc. As soon as this storage space is full, the buffer space then acts as additional storage space and as a buffer for rainwater;

- the storage space (3) / buffer space (9) volume ratio of

BL-5093 the water tank (T) is greater than or equal to 2, preferably greater than 5 and, in particular, is located between 5 and 20;

- the vertical interior wall or walls in porous concrete (8) of the water tank (T) define a porous surface which is turned towards the storage space (3), the ratio between the storage volume (3) in m ³ and the porous surface in m ² being located between 0.5 and 1.5;

- the flow opening (5) for the evacuation of rainwater has a passage which makes it possible to limit the rate of evacuation of water through this flow opening (5) between 1 and 20 liters / second, preferably at 5 liters / second maximum (this flow opening can optionally be fitted with a valve or a valve mechanism to limit the water discharge rate, for example to 1; 2; 3 ; 4; 5; 10 liters / s);

- The buffer system has a drainage opening (5) for the evacuation of rainwater, the drainage opening (5) being provided with a passage system which makes it possible to limit the evacuation rate of water through this flow opening (5) between 1 and 20 liters / second, preferably at 5 liters / second maximum as long as the water level in the storage space (3) is below a level d maximum water. The passage system has a porous concrete element with an interior compartment which is connected to the drain opening (5) via a piping system. The porous concrete element is composed, at least in part, of a hardened porous draining concrete made by hardening a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water to obtain an open pore volume of 8 to 12% included in the hardened porous draining concrete.

- The water tank has an almost vertical porous concrete inner wall which divides the interior volume of the water tank into a storage space (3) and a buffer space (9), the buffer space ( 9) of the water tank (T) being connected by a connection pipe to a buffer tank (BT), this connection pipe being maintained at a

BL-5093 upper level at the bottom of the buffer space (9) and at the bottom of the buffer tank (BT). The buffer tank has a drain opening (50) which is located above the bottom of the buffer tank (BT), the drain opening (50) being provided with a suitable passage system to limit the water discharge rate through this flow opening (50) between 1 and 20 liters / second, preferably to 5 liters / second maximum or is connected to such a passage system, the passage system comprising a porous concrete element with an interior chamber which is connected via a piping system with the flow opening (50), the porous concrete element being manufactured, at least in part, from '' a hardened porous draining concrete which is made by hardening a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water to obtain an open pore volume of 8 to 12% included in hardened porous draining concrete. The passage system is preferably located in the buffer tank (BT).

- The porous concrete element rests on the bottom of the buffer space (9) or of the buffer tank (BT), the porous concrete element containing one or more porous walls as well as a porous upper face, the the piping system preferably having an overflow system for discharging water as soon as the water level in the buffer space or in the buffer tank exceeds a higher level.

-The water tank or the water tank of the buffer system is provided with at least two separate overflows (3A, 9A), namely a first overflow (3A) for the storage space (3) for the evacuation of rainwater as soon as the water level in the storage space (3) exceeds the level (H3A) of this first overflow (3A) and a second overflow (9A) for the 'buffer space (9) for the evacuation of rainwater as soon as the water level in the buffer space (9) exceeds the level (H9A) of this second overflow (9A);

- The first overflow (3A) is, at least in part, at a level

BL-5093 (H3A) which is located below the lowest level (H9A) of the second overflow (9A). These two overflows can evacuate water by the same evacuation pipe towards a stream or a river;

- The first overflow (3A) has a passage surface which is greater than the passage surface of the second overflow (9A);

- The vertical interior wall (s) made of porous concrete (8) have an upper face (8B) which is located at a level (H8B) higher than the lower edge of the first overflow (3A) and the lower edge of the second overflow (9A). This makes it possible to prevent water from being able to flow above the upper edge of the interior wall (8);

- At least one vertical internal wall of porous concrete (8) is mounted in a mobile and / or removable manner with respect to the water tank, a lower edge (8X) of the internal wall which can rest on the bottom of the water tank d 'water (T). This is advantageous for assembly and / or maintenance work;

- The water tank has a removable cover with manhole;

- The water tank is provided with at least two separate buffer spaces, namely at least a first buffer space (90) which is located along the bottom of a storage space (3), this first buffer space ( 90) collecting water from the storage space (3) via a porous concrete wall at least partially horizontal (80) and at least a second buffer space (9) which cooperates with a wall in almost vertical porous concrete (8) for collecting water from the storage space (3), and characterized in that the first buffer space (90) and the second buffer space (9) are connected by a pipe or a channel (100) which is preferably located along the bottom of the water tank;

- The first buffer space (90) and the second buffer space (9)

BL-5093 are connected by a pipe or a channel (100) with an upper edge (100A) which has a slope with respect to a horizontal plane, so that this upper edge (100A) is raised in the direction of second buffer space (9);

- The water tank (T) has at least two separate storage spaces (3.30), these two separate storage spaces (3.30) being connected via an overflow pipe (31 ) which is intended to transfer water from a first storage space (3) to a second storage space (30) as soon as the first storage space (3) is practically full of water, the second storage space (30) being provided with an overflow (3A) which is situated at a level lower than the overflow pipe (31);

- The intake opening (4) is provided with a system by which, if the flow of rainwater flowing into the tank through the intake opening (4) is less than a determined flow , the system is adapted to directly discharge at least part of the rainwater flow to the buffer space of the water tank;

- Combinations of two or more of these specificities and / or characteristics.

The invention also relates to the use of one or more buffer systems according to the invention for regulating the flow rates and / or water levels in streams and / or rivers and / or ditches and / or areas liable to flooding by regulation. / adjusting the discharge rates of rainwater from roofs, walkways, roads and / or water from a canal, stream, ditch or river , the rainwater and / or the water flowing to one or more storage spaces of one or more buffer systems according to the invention and this rainwater and / or water being caused to flow by the / the vertical walls made of porous concrete from the water tanks to their buffer spaces before being evacuated to streams and / or rivers and / or ditches and / or floodplains.

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Specific variants according to the invention will now be described as advantageous examples according to the invention. This description refers to the attached drawings.

These drawings illustrate:

- Fig. 1, a top view of a first alternative embodiment of a buffer system (water tank T) according to the invention,

- Fig. 2, a view of the water tank in FIG. 1 in cross section along the line II-II,

- Fig. 3, a top view of a second alternative embodiment of a water tank according to the invention,

- Fig. 4 to 6 inclusive, respective cross-sectional views of the water tank in FIG. 3 along lines IV-IV, V-V and VI-VI,

- Fig. 7, a view of a detail of the water tank in FIG. 3,

- Fig. 8A and Fig. 8B, views of a detail of an intake opening for a water tank according to the invention,

- Fig. 9, a view of two water tanks which are connected by means of pipes,

- Fig. 10, a view in vertical section of a third alternative embodiment according to the invention,

- Fig. 11, a cross-sectional view along the line XI-XI in FIG. 10,

- Fig. 12, a top view of a fourth variant which is identical to the variant of FIG. 3,

- Fig. 13, a cross-sectional view along the line XIII-XIII in FIG. 12,

- Fig. 14, a view of part of an inspection route along a canal or ditch, with a series of water tanks according to the invention,

- Fig. 15, a top view of a fourth variant,

- Fig. 16, a cross-sectional view along the line XVI-XVI in FIG. 15,

- Fig. 17, a top view of a fifth alternative embodiment of a buffer system according to the invention,

- Fig. 18, a cross-sectional view along the line XVIIIXVIII in FIG. 17,

- Fig. 19, a top view of a sixth alternative embodiment of a

BL-5093 buffer system according to the invention,

- Fig. 20, a cross-sectional view along the line XX-XX in FIG. 19, and

- Fig. 21, a cross-sectional view of a seventh variant.

Figure 1 shows a water tank (T) for collecting and storing rainwater. This water tank includes:

- one or more external walls (1) which are made from non-porous concrete and define an internal volume (2), part of which acts as a storage space (3) for rainwater / water with storage volume for rainwater / water;

- an intake opening (4) through which rainwater / water can flow into the storage space (3);

- a drainage opening (5) for the evacuation of rainwater / water outside the water tank (T);

- a cover (6) with a manhole (7); and

- a control system (5.8) to control the flow of rainwater / water out of the water tank (T).

The control system (5,8) consists of at least one or more vertical internal walls of porous concrete (8) which extend into the internal volume (2) of the water tank (T) and which divides (nt) this interior volume at least in a storage space (3) for rainwater / water and a buffer space (9) with a buffer volume for collecting the water flowing through the or the internal walls of porous concrete (8).

The buffer space (9) is provided with the drainage opening (5) for the evacuation of rainwater. This flow opening is located along the bottom of the tank (T).

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The inner wall of porous concrete (8) is made of special draining concrete to obtain a permeability adapted to water. Draining concrete has a minimum water permeability of 0.05 liters / m ² / s and a maximum water permeability of 0.1 liters / m ² / s to 5 liters / m ² / s, preferably from 0.1 liter / m ² / s to 1 liter / m ² / s, for example 0.2 to 0.75 liter / m ² / s included. The minimum permeability to water is preferably 0.2 to 0.5 liters / m ² / s.

This water permeability of this vertical porous inner wall is measured for a storage space (3) which is practically full of water, while the buffer space (9) is practically empty. For this measurement, for example, a pump is used to keep the buffer space practically empty.

The maximum permeability to water of the draining concrete can also be determined by making a porous concrete plate which serves as the bottom of a test tank. The test tank (of a height equal to the height of the tank) will then be filled with water and the water flow will be measured for the water flowing through the porous bottom.

Draining concrete is preferably made by hardening a mixture of cement, aggregates and water in order to preferably obtain a total open pore volume of 8 to 12% included in the hardened concrete. For concrete, aggregates with a particle size of 6 mm to 14 mm inclusive are preferably used. Preferably, the aggregates of the draining concrete contain 15% by weight of aggregates with a particle size greater than 8 mm, while the proportion by weight of water / cement is less than 0.5 and ideally situated between 0.35 and 0 , 42.

The mixture of uncured concrete (without water) contains less than 30% by weight of aggregates, better between 25 and 27% by weight with a particle size of less than 4 mm. The concrete mixture can also contain one or more additives.

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The mixture of uncured concrete (without water) can contain up to 15% by weight of sand, with a particle size less than 4 mm, for example from 2 to 4 mm. The sand is preferably formed of round grains and comes for example from a river. Examples of sand contents are 2; 5; 8; 10; 12% by weight.

In order to further control the water permeability of the concrete, one or more additives can be added to the mixture of hardened concrete, such as an aqueous polymer dispersion, in particular an aqueous polymer / acrylate / methacrylate copolymer dispersion, for example a copolymer of an aqueous dispersion of acrylic acid ester / vinyl ester. One can for example add 10 to 30% by weight of a polymer dispersion in concrete, this percentage by weight being measured relative to the weight of cement.

The water tank has a height (H) of less than 3 m, for example from 2 to 2.5 m.

The height of the tank is preferably greater than 1 m.

In its first variant (Figure 1), the total water discharge capacity varies linearly with the height of the water between 0% and 100%.

In a second variant, the total water discharge capacity measured for a water height corresponding to half of the storage space and, preferably, at a water height of 0.3 m , is equal to 80% to 100%, preferably 90% to 100% inclusive of that measured in the case of storage space almost completely filled with water (3).

This property provides better control of the water flowing through the porous wall.

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In the variant of FIG. 3, the porous concrete contains several zones (10) having a higher permeability to water compared to the average permeability to water of porous concrete. These areas (10) are located in the vicinity of the bottom, for example at a height (h) of the bottom (3B) of the storage space (3) which is less than 50 cm and, preferably, less than 30 cm .

These areas (10) can be fabricated using aggregates of greater grain size. These zones can also form an intermediate layer in the porous wall, this intermediate layer being situated at a height between 20 and 50 centimeters relative to the bottom (3B).

The storage space (3) / buffer space (9) volume ratio is greater than or equal to 2, preferably greater than 5 and, in particular, between 5 and 20.

The internal porous concrete wall (8) defines a porous surface which is turned towards the storage space (3), the ratio of storage volume (3) in m ³ / porous surface in m ² being situated between 0.5 and 1.5 (for example, between 0.7 and 1.25, preferably 0.8; 0.9; 1; 1.1 and 1.2). This ratio provides good control of the maximum flow rate of water flowing through the porous wall and a sufficient storage volume for rainwater.

The drainage opening (5) for the evacuation of rainwater has a passage which is suitable for limiting the rate of evacuation of water through this drainage opening (5) between 1 and 20 liters / second , preferably at 5 liters / s maximum.

The water tank has at least two separate overflows (3A, 9A), namely a first overflow (3A) for the storage space (3) for the evacuation of rainwater storage space as soon as the water level in the storage space (3) exceeds the level (H3A) of this first overflow (3A) and a second overflow (9A) for the space buffer (9) for draining water from

BL-5093 rains as soon as the water level in the buffer space (9) exceeds the level (H9A) of this second overflow (9A).

By means of these overflows 3A, 9A, two water tanks T, Tl according to the invention can be connected by pipes 20,21. The tank Tl is for example situated at a lower level with respect to the tank T so that the water can flow freely from the tank T to the tank Tl. The overflow opening 3A of the tank T is connected to the inlet opening 4 of the tank Tl via the pipe 20. As soon as the storage space 3 of the tank T is full, the water flows from this storage space 3 to the storage space 3bis of the Tl tank (see Figure 9)

The overflow 9A of the buffer space 9 of the tank T is provided with an inlet 40 via the pipe 21. In the case where the buffer space 9 of the tank T is practically full, the water then flows from the buffer space of the tank T to the buffer space 9 of the tank Tl. Via the pipes 22, the water is discharged from the buffer spaces 9 of the tanks T and Tl to the stream S.

The first overflow (3A) is located, at least in part, at a level (H3A) which is located above the lowest level (H9A) of the second overflow (9A).

The first overflow (3A) has a passage surface which is greater than the passage surface of the second overflow (9A).

With these overflows 3A, 9A, the water level in the buffer space 9 is always lower than the water level in the storage space 3, even in the event of thunderstorm rain.

The inner porous concrete wall (8) has an upper face (8B) which is at a level (H8B) above the edge

BL-5093 lower of the first overflow (3A) and the lower edge of the second overflow (9A). This is advantageous to prevent water from flowing over the interior wall of the storage space towards the buffer space 9.

In the variant shown in Figure 1, the cover 6 is removably mounted on the tank 1. In this case, it is also advantageous to mount the inner wall of porous concrete 8 removably in the tank. The bottom edge 8X of the wall (8) rests on the bottom of the tank, possibly with a rubber insert.

The manhole 7 provides a view of the water level in the two spaces (3, 9). Maintenance work can also be carried out using this inspection window in the tank.

In the alternative embodiment of FIG. 3, the water tank comprises three or more than three separate buffer spaces (9, 90, 91), namely (a) at least of the first and second buffer spaces (90, 91 ) which are located along the bottom of a storage space (3), the first and second buffer spaces (90) collecting water from the storage spaces (3, 30) via a concrete wall porous at least partly horizontal (80, 81) and (b) at least a third central buffer space (9) which collaborates with two almost vertical porous concrete walls (8.8 bis) to collect water from the storage spaces (3, 30).

The position of the porous walls 80, 81 along the bottom of the tank can be maintained by fixing means (rods 111).

The first and second buffer spaces are connected with the third buffer space (9) by pipes (100) which are located along the bottom of the water tank. The pipes 100 show a slope relative to the horizontal plane so that the upper edge (100A) of these pipes goes up in the direction

BL-5093 of the third buffer space (9). In this way, it is possible to prevent air or gas from remaining in the buffer spaces 90, 91, which can be detrimental for the passage of water.

The two separate storage spaces (3.30) are connected via an overflow pipe (31). This pipe 31 is intended to evacuate water from the first storage space (3) to the second storage space (30) as soon as the first storage space (3) is practically full of water, the second storage space (30) being provided with an overflow (3A) which is located under the overflow pipe (31).

In a possible alternative embodiment, the intake opening (4) can be provided with a control system 400, so that the flow of rainwater flowing in the tank T is less than a given flow rate, the control system 400 is adapted to directly discharge at least part of the rainwater flow rate to the buffer space 9. With such a control system 400, the rainwater can be partly discharged towards storage space 3, as well as partly towards the buffer space, for short-term precipitation without thunderstorm character.

Such a system is illustrated in Figures 8A and 8B. The rainwater W flows into a chamber 401 which has an open interior vessel 402 in order to collect at least part of the rainwater. The bottom of this vase 402 has a hole 402A. In this vase, moves a float 403 with a surface 403A which acts as a valve system. The inner vessel 402 is in relation to an inlet opening 40 of the buffer space 9 by means of a pipe 41.

For small water flows W, the water flows into the inner vessel 402. Since the flow is not sufficient, the float 403 remains in a lower position so that part of the rain flows directly to buffer space 9, while another

BL-5093 part flows to storage space 3 through opening 402A (see Figure 8A).

In the event of a thunderstorm rain, the water level in the inner vessel increases so that the float 403 is in the closed position to block (possibly partially) the intake of the pipe 41. In such a closed position, almost all the rain flows into the storage space of tank T.

A third alternative embodiment of a water tank according to the invention is illustrated in FIG. 10.

Tank T contains a concrete tank (waterproof) with a flow 5 along the bottom IB. Along the bottom IB, the tank is provided with one or more support elements 1C for a plate 80 made of porous concrete. The round plate 80 rests on the support elements 1C. Above the plate 80 is a cylindrical pipe 82 made of porous concrete.

The plate 80 may optionally be provided with a hole 80G to connect the buffer zones 9, 90 to each other. If this plate 80 is not provided with the hole 80G, the buffer spaces are in contact via the open pores of plate 80.

The cylindrical pipe 82 can preferably be placed in the tank via the manhole 7. The correct placement of the pipe can be obtained by intermediate elements 110 which are located between the upper edge of the pipe 82 and the surface bottom of the cover.

Figs. 12 and 13 are views of an alternative embodiment equivalent to the alternative embodiment of Figures 3 to 6 inclusive, except for a few adaptations.

The vessel and / or the vertical porous walls 8, 8bis are provided with support elements 1C for the porous plates 80, 81. The

BL-5093 position of the plates on the support elements 1C is maintained by the use of fastening means 111 which are housed for example partly in a wall of the tank.

Figure 14 is a view of a ditch or channel 200 with a dam 201 and two inspection lanes 202, 203. Along the inspection lane 203 are arranged several water tanks according to the invention. The water tank 1 is in relation to the channel 200 by means of the pipe 204. The storage spaces for the water tanks 1.1 bis, tie, etc. are in such a way that the water from the storage space of tank 1 can be evacuated to the storage space of the Ibis tank as soon as the water level in storage space 3 of the tank 1 exceeds a certain level.

Outlets 5 of all tanks 1.1 bis, etc. are in connection with a drain pipe 205 for discharging water into the channel 200, after the dam 201.

The water tanks according to the invention can therefore be used to regulate the water level in the canal. As soon as the water level exceeds a maximum level, the water tanks 1.1 bis, etc. can collect water from the canal before discharging it late into the canal, which offers a solution against stormy rains (with heavy precipitation in a short period of time).

Since water tanks can be fitted under the inspection lanes, the fitting of these tanks can be carried out at the same time as the fitting of these inspection lanes.

Figures 15 to 21 inclusive are views of alternative embodiments of buffer systems according to the invention.

In the variant of Figures 15 and 16, the buffer system contains a rectangular T tank with an inner wall of vertical porous concrete (8) which distributes the interior volume of the tank into a storage space (3) and a space buffer (9).

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The tank T also has an inlet opening (4) which is located at a level higher than the upper level of the interior wall (8), the water being able to flow directly into the buffer space (9) in the event of storm rain. Storm rain can then be discharged through an overflow pipe (51) which is connected to the drainage opening (5).

The discharge opening (5) is connected with a porous concrete element (85) via a horizontal pipe (86) (which is located at a distance from the bottom of the buffer space). The porous concrete element (85) defines an interior chamber (87) (to collect the water which flows through the porous walls of the element (85)) connected via a system of pipes ( 86) with the flow opening (5). The porous concrete element is made, at least in part, from a hardened porous draining concrete which is made by curing a mixture of cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water for an open pore volume of 8 to 12% included in the hardened porous draining concrete.

The open interior chamber 87 is connected to the overflow pipe.

The variant of Figures 17 and 18 is similar to the variant of Figures 15 and 16. The buffer system of Figures 17 and 18 contains a water tank (T) whose buffer space is connected to a buffer tank (BT) by a connection pipe 55. The connection pipe 55 is located at a level higher than the bottom of the buffer space (9) of the tank T and of the bottom of the buffer tank (BT).

The buffer tank is provided with a drainage opening (50) which is situated above the bottom of the buffer tank, the drainage opening (50) being connected with a passage system which is suitable for limiting the flow. draining water through this opening

BL-5093 flow (50) between 1 and 20 liters / second and, preferably, at 5 liters / second maximum. The passage system contains a porous concrete element (85) with an interior chamber (87) which is connected to the flow opening (50) via a pipeline system (86). The porous concrete element is made, at least in part, of a hardened porous draining concrete which is made by hardening a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and l water to obtain an open pore volume of 8 to 12% included in the hardened porous draining concrete.

The porous concrete element rests on the bottom of the buffer space (9bis) or of the buffer tank (BT), the porous concrete element (85) comprising one or more porous walls as well as a porous upper face and preferably, the hose system 86 being provided with an overflow system (pipe 51) for discharging water as soon as the water level in the buffer space (9) or in the buffer tank ( BT) exceeds a higher level (for example, a level close to the upper edge of the inner wall (8)).

The buffer system of Figures 19 and 20 is equivalent to the buffer system of Figures 17 and 18 except that the pipe 51 is connected to the inner chamber (87) of the porous element (85).

Figure 21 shows a buffer system with several tanks Tl, T2, etc. to collect the rainwater that is connected to each other. The tanks are therefore connected to a buffer system according to the invention for controlling the evacuation of water (water tank (T) with porous vertical inner wall (8) and buffer tank (BT) with element (85)).

Claims (13)

1. Rainwater / water buffer system which comprises at least one water tank (T) for at least temporary collection and storage of rainwater / water, and for a controlled evacuation of water , the water tank (T) comprising at least: - one or more external walls (1) which are made from non-porous concrete and define an internal volume (2), part of which acts as a storage space (3) for rainwater / water with storage volume for rainwater / water; - an intake opening (4) through which rainwater / water can flow into the storage space (3); - a drainage opening (5) for the evacuation of rainwater / water outside the water tank (T); - a cover (6) with a manhole (7); and - a control system (5, 8) for controlling the rate of discharge of rainwater / water from the water tank (T), characterized in that the control system (5, 8) consists of at least one or more vertical internal walls of porous concrete (8) which extend into the internal volume (2) of the water tank (T) and which divide (s) this internal volume at less in a storage space (3) for rainwater / water and a buffer space (9) with a buffer volume to collect the water which flows through where the inner walls of porous concrete (8 ), characterized in that the buffer space (9) is provided with the drainage opening (5) for the evacuation of rainwater / water, and characterized in that the wall (s) vertical porous concrete interiors (8) are made of hardened draining concrete made of BL-5093 hardening a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water to obtain an open pore volume of 8 to 12% included in the hardened porous draining concrete , the hardened porous draining concrete having a water permeability of 0.05 liter / m ² / s to 5 liters / m ² / s, preferably from 0.1 liter / m ² / s to 3 liters / m ² / s included and, more particularly, between 0.1 liter / m ² / s and 1 liter / m ² / s, this water permeability being measured for a storage space almost completely filled with water (3) and a substantially empty buffer space (9). 2. Buffer system according to claim 1, wherein the water tank (T) has a height (H) of less than 3 meters, characterized in that the total water discharge capacity measured for a height of water from half of the storage space (3) and, preferably, at a water height of 0.3 m in the storage space (3), is equal to 80% to 100%, preferably 90% to 100% inclusive of that measured in the case of storage space (3) almost completely filled with water and a buffer space (9) substantially empty. 3. Buffer system according to one of claims 1 or 2, characterized in that the hardened porous draining concrete has one or more zones having a higher permeability to water compared to the average permeability to water of the draining concrete cured porous, this or these zones (10) lying at a height (h) from the bottom (3B) of the storage space (3) which is less than 50 cm, and preferably less than 30 cm. 4. Buffer system according to one of the preceding claims, characterized in that the volume ratio of storage space (3) / buffer space (9) for the water tank (T) is greater than or equal to 2, preferably greater than 5 and, in particular, between 5 and 20. 5. Buffer system according to one of the preceding claims, characterized in that the interior wall or walls of porous concrete (8) of the water tank (T) define a porous surface which BL-5093 faces the storage space (3), the storage volume (3) in m ³ / porous surface in m ² ratio being between 0.5 and 1.5. 6. Buffer system according to one of the preceding claims, characterized in that the buffer system has a flow opening (5) for the evacuation of rainwater, the flow opening (5) being provided a passage system which makes it possible to limit the water discharge rate through this flow opening (5) between 1 and 20 liters / second, preferably to 5 liters / second maximum as long as the water level in the storage space (3) is below a maximum water level, in which the passage system has a porous concrete element with an interior compartment which is connected to the drainage opening (5) by the intermediary of a piping system, and in which the porous concrete element is composed, at least in part, of a hardened porous draining concrete made by hardening a mixture comprising at the core of the cement, aggregates of a grain size from 6 mm to 14 mm included and water to obtain an open pore volume of 8 to 12% included in the hardened porous draining concrete. 7. Buffer system according to one of the preceding claims, characterized in that the water tank has an inner wall of almost vertical porous concrete (8) which divides the interior volume of the water tank into one storage space (3) and a buffer space (9), in which the buffer space (9) of the water tank (T) is connected by a connecting pipe to a buffer tank (BT), this pipe connection being maintained at a level higher than the bottom of the buffer space (9) and the bottom of the buffer tank (BT), and in which the buffer tank is provided with a flow opening (50) which is located at the -above the bottom of the buffer tank (BT), the flow opening (50) being provided with a passage system which is suitable for limiting the rate of discharge of water through this flow opening (50) between 1 and 20 liters / second, preferably 5 liters / second maximum or is connected to such a passage system, the passage system comprising a porous concrete element with an interior chamber which is connected via BL-5093 of a piping system with the flow opening (50), the porous concrete member being fabricated, at least in part, from a hardened porous draining concrete which is manufactured by curing a mixture comprising at least cement, aggregates with a particle size of 6 mm to 14 mm inclusive and water to obtain an open pore volume of 8 to 12% included in the hardened porous draining concrete. 8. Buffer system according to one of claims 6 or 7 characterized in that the porous concrete element is supported on the bottom of the buffer space (9) or of the buffer tank (BT), the concrete element porous containing one or more porous walls as well as a porous upper face, the piping system preferably being provided with an overflow system for discharging water as soon as the water level in the buffer space or in the buffer tank exceeds a higher level. 9. Buffer system according to one of the preceding claims, characterized in that the water tank is provided with at least two separate overflows (3A, 9A), namely a first overflow (3A) for the space of storage (3) for the evacuation of rainwater as soon as the water level in the storage space (3) exceeds the level (H3A) of this first overflow (3A) and a second overflow full (9A) for the buffer space (9) for the evacuation of rainwater as soon as the water level in the buffer space (9) exceeds the level (H9A) of this second overflow ( 9A). 10. Buffer system according to one of the preceding claims, characterized in that the water tank is provided with at least two separate buffer spaces, namely at least a first buffer space (90) which is located along the bottom a storage space (3), this first buffer space (90) collecting water from the storage space (3) by means of a porous concrete wall at least partially horizontal (80) and at least one second buffer space (9) which cooperates with an almost vertical porous concrete wall (8) to collect water from the storage space (3), BL-5093 characterized in that the first buffer space (90) and the second buffer space (9) are connected by a pipe or a channel (100) which is preferably located along the bottom of the tank water. 11. Buffer system according to claim 10, characterized in that the water tank (T) has at least two separate storage spaces (3.30), these two separate storage spaces (3.30) being connected by l 'via an overflow pipe (31) which is intended to transfer water from a first storage space (3) to a second storage space (30) as soon as the first storage space (3) is almost full of water, the second storage space (30) being provided with an overflow (3A) which is located at a level lower than the overflow pipe (31). 12. Buffer system according to one of the preceding claims, characterized in that the intake opening (4) is provided with a system by which, if the flow of rainwater flowing in the tank by the intake opening (4) is less than a determined flow rate, the system being adapted to directly discharge at least part of the flow of rainwater to the buffer space (9) of the water tank. 13. Use of one or more buffer systems according to the invention for regulating the flow rates and / or water levels in streams and / or rivers and / or ditches and / or flood zones by regulating / adjusting the flow rates drainage of rainwater from roofs, alleys, roads and / or water from a canal, stream, ditch or river, rainwater and / or the water flowing to one / more storage spaces of one or more buffer systems according to the invention and this rainwater and / or water being caused to flow through the vertical wall (s) made of porous concrete from water tanks to their buffer spaces before being evacuated to streams and / or rivers and / or ditches and / or floodplains.