NL2023362A - Rain water tank - Google Patents

Abstract

The tank is provided with a porous concrete inner wall (8) to define a storage space (3.30) and a buffer space (9.90.91). The inner wall is made of a water-draining concrete with a maximum water permeability of 0.05 liters / m2 / s to 5 liters / m2 / s, preferably of 0.1 liters / m2 / s to 3 liters / m2 / s s, in which said water permeability has been measured at an almost water-rich storage space (3).

Description

Θ 2023362 © A PATENT APPLICATION © Application number: 2023362 (22) Application submitted: 22 June 2019 © Int. Cl .:

E03F5 / 10 (2019.01)

(30) Priority: 28 June 2018 BE 2018/0079 © Applicant (s): M.H.C. NV in Sint-Truiden, Belgium, BE © Application registered: January 6, 2020 © Inventor (s): Luc Vandebeek in Alken (BE) © Request published: January 7, 2020 © Authorized representative: ir. R. Wijnstra in Amsterdam

© Rainwater tank (57) The tank is provided with a porous concrete inner wall (8) to define a storage space (3.30) and a buffer space (9.90.91). The inner wall is made of a water-draining concrete with a maximum water permeability of 0.05 liters / m ² / s to 5 liters / m ² / s, preferably from 0.1 liters / m ² / s to 3 liters / m ² / s, where that water permeability has been measured at an almost water-rich storage space (3).

A 2023362

This publication corresponds to the documents originally submitted.

Short indication: Rainwater tank

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. In case of insufficient use of water, the water tanks remain almost full of water, and in case of heavy rain, they do not offer a solution against excessive water discharge to watercourses.

To solve storm water problems, a system is used that assembles plastic modules with the aid of a porous textile material. Building such a system requires underground work to achieve sufficient soil stability. A top layer would also be useful to be able to ride on it.

Water tanks that can also be used as drainage systems are described, for example, in WO95 / 16833. In the draining system according to this document, perforated walls and porous textile material are used to define a storage volume, with water flowing through the walls and the porous textile material to allow water to infiltrate into the substrate.

Such a system requires earthworks to be sure that there is a porous primer layer around the walls with the porous textile material. Moreover, in the case of wet soils, such systems are totally inefficient. Indeed, groundwater will flow through the porous side walls in the tank, thus limiting the space for collecting rainwater.

The use of porous concrete layers is known for driveways, roads and parking. The porous concrete has a very high permeability and is intended for transporting water to an underlying soil layer. As soon as that primer is wet, the efficiency of the porous concrete will decrease.

DE9412053U1 describes a water tank that is provided with a filter element and with a spout opening that is at a level that is above the filter element. The filter element therefore does not work as a means to control the drainage of rainwater.

US2012 / 01 11428 describes a water tank made in HDPE for collecting rain water, wherein the water tank is provided with a filter structure with a filter foil, to collect solid particles with a size from 20 µl. Such a filter does not work as a means to control the drainage of rainwater.

DE10231241 describes a filter element of porous concrete. The water flows through the porous concrete from bottom to top. Moreover, as soon as there is too much rain water, solid particles deposit on the horizontal filter element, so that the drainage of rain water cannot be controlled.

DE4338085 describes a filter installation with horizontal filter elements to filter the rainwater. Such an installation also does not work as a means to control the drainage of rainwater from the tank.

All these known systems do not offer efficient solutions to control the drainage of rainwater to streams or rivers during a rainy period and after a rainy period, for example in case the soil is too wet.

The invention relates to a water buffer system for storing rainwater / water. With the buffer system according to the invention, the application of a porous primer layer around the water tank is no longer necessary. The drainage of rainwater does not depend on the soil layer in which the water tank is placed. By effectively controlling the rainwater drainage by means of one or more buffer systems according to the invention, it is possible to control the water flow that flows to the rivers, canals, streams, flood areas, etc. Water buffer systems according to the invention can also be used as a means to control the water level in canals, canals, rivers, etc.

For example, water buffer systems according to the invention can be used along (and / or as part of) cribs, dams, towpaths and inspection paths of canals, canals, streams, rivers, etc. to at least partially control water levels.

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

The buffer system according to the invention comprises at least one water tank (T) for collecting and (at least temporarily) storing rainwater / water, and for a controlled water discharge. The water tank of the buffer system according to the invention comprises at least:

- one or more outer walls (1) made of non-porous concrete and defining an inner volume (2), a part of which serves as storage space (3) of rainwater / water with a storage volume for rainwater / water;

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

- an outlet opening (5) for draining rainwater / water from the water tank (T);

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

- a control system (5,8) to control the drainage rate of rainwater / water from the water tank (T).

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

The buffer space (9) is provided with the outlet opening (5) for draining rainwater / water, while the porous concrete vertical inner wall (s) (8) is / are made from a hardened water-draining concrete that is made by hardening a mixture of at least cement, aggregates with a particle size of 6 mm to 14 mm and water to obtain an open pore volume of 8 to 12% in the hardened porous water-draining concrete, wherein the hardened porous water-draining concrete has a water permeability of 0.05 liters / m ² / s to 5 liters / m ² / s, preferably from 0.1 liters / m ² / s to 3 liters / m ² / s, and most preferably between 0.1 liters / m ² / s s to 1 liter / m ² / s (such as 0.1; 0.2; 0.4; 0.5; 0.7; 0.8 and 1 liter / m ² / s), wherein said water permeability is measured is at an almost water-rich storage space (3) and an empty buffer space (9).

Details and characteristics of advantageous embodiments 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:

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

- in its first embodiment (Fig. 1) the total water discharge capacity varies linearly with the water level present between 0% and 100%,

- in a second embodiment, the total water drainage capacity measured at water level of half the storage space, and preferably at a water height of 0.3 m, is equal to 80% to 100%, preferably 90% to 100% of this measured at an almost water-rich storage space (3) and an almost empty buffer space (9);

- the hardened porous water-draining concrete has one or more zones with increased water permeability relative to the average water permeability of the hardened porous water-draining concrete, said zone or zones (10) lying / lying at a height (h) from the bottom (3B) of the storage space (3) that is smaller than 50 cm, and preferably smaller than 30 cm. In this way, it is better to arrange rainwater drainage.

At normal rain intensities, the water that flows into the water tank is drained to the stream with a slight delay. In that case, the storage space is only partially used. In heavy rain showers, the storage space and the buffer space are almost full. The water flow that is discharged to the stream is virtually limited by the passage of the outlet opening (5). The storage area acts as the first means of regulating / regulating the rainwater flow to the stream, canal, canal, river, etc. As soon as that storage space is full, the buffer space then acts as an additional storage space and buffer for rainwater;

- the volume ratio of storage space (3) / buffer space (9) of the water tank (T) is greater than or equal to 2, preferably greater than 5, and most preferably between 5 and 20;

- the porous concrete vertical inner wall (s) (8) of the water tank (T) defines / define a porous surface facing the storage space (3), the ratio of storage volume (3) in m ³ / porous surface in m ² is between 0.5 and 1.5;

- the outlet opening (5) for draining rainwater has a passage which is suitable for limiting the water discharge flow through that outlet opening (5) between 1 and 201iter / s and preferably to a maximum of 51iter / s (that outlet opening can optionally be provided with a valve or valve mechanism to limit the water discharge rate, for example to 1; 2;

; 4; 5; 10 liters / s);

- The buffer system has an outlet opening (5) for draining rainwater, wherein as long as the water level in the storage space (3) is lower than a maximum water level, the outlet opening (5) is provided with a passage system that is suitable for passing the water discharge through that limit the outlet opening (5) between 1 and 201 liters / s and preferably to a maximum of 51 liters / s. The passage system comprises a porous concrete element with an inner chamber which is connected to the outlet opening (5) via a pipe system. The porous concrete element is at least partially made from a hardened porous water-draining concrete that is made by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water around an open pore volume of 8 to 12% to obtain in the hardened porous water-draining concrete;

- The water tank is provided with an almost vertical porous concrete inner wall that splits the inner volume of the water tank into a storage space (3) and into a buffer space (9), the buffer space (9) of the water tank (T) being connected via a connecting pipe to a buffer tank (BT), wherein said connecting pipe is located at a level above the bottom of the buffer space (9) and above the bottom of the buffer tank (BT). The buffer tank is provided with an outlet opening (50) which is located above the bottom of the buffer tank (BT), the outlet opening (50) being provided or connected to a passage system suitable for limiting the water discharge flow through that outlet opening (50) between 1 and 201iter / s and preferably up to a maximum of 51iter / s, wherein the passage system comprises a porous concrete element with an inner chamber which is connected to the outlet opening (50) via a pipe system, and at least partially with the porous concrete element is made from a hardened porous water-draining concrete that is made by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water to obtain an open pore volume of 8 to 12% in the hardened porous water draining concrete. The passage system is preferably located in the buffer tank (BT);

- The porous concrete element is supported on the bottom of the buffer space (9) or of the buffer tank (BT), wherein the porous concrete element contains one or more porous walls, as well as a porous upper side, and wherein, preferably, the pipe system is provided with an overflow system for draining water as soon as the water level in the buffer space or in the buffer tank exceeds an upper 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 draining rainwater as soon as the water level in the storage space (3) level (H3A) of that first overflow (3A), and a second overflow (9A) for the buffer space (9) for draining rainwater once the water level in the buffer space (9) exceeds the level (H9A) of that second overflow ( 9A);

- the first overflow (3A) lies at least partially at a level (H3A) that is below the lowest level (H9A) of the second overflow (9A). The two overflows can drain water to the same drainage pipe to a stream or river;

- the first overflow (3A) has a passage surface that is larger than the passage surface of the second overflow (9A);

- the porous concrete vertical inner wall (s) (8) have / have an upper side (8B) that lies at a level (H8B) that is higher than the lower edge of the first overflow (3A) and the lower edge of the second overflow (9A) ). This is to prevent water from flowing above the top of the inner wall;

- at least one porous concrete vertical inner wall (8) is movable and / or removably mounted relative to the water tank, whereby a lower edge (8X) of the inner wall can rest on the bottom of the water tank (T). This is advantageous for assembly and / or maintenance work;

- the water tank is provided with a removable lid 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), said first buffer space (90) collecting water from the storage space (3) via an at least partially horizontal porous concrete wall (80), and at least a second buffer space (9) cooperating with a substantially vertical porous concrete wall (8) to collect 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 tube or channel (100), which is preferably located along the bottom of the water tank;

S

- said first buffer space (90) and second buffer space (9) are connected by means of a tube or channel (100) to an upper edge (100A) which has a slope with respect to a horizontal plane, so that said upper edge (100A) the direction to the second buffer space (9) rises;

- the water tank (T) has at least two separate storage spaces (3.30), said two separate storage spaces (3.30) being connected via an overflow pipe (31) intended for carrying water from a first storage space (3) to a second storage space (30), as soon as the first storage space (3) is substantially water-filled, the second storage space (30) being provided with an overflow (3A) located at a level below the overflow pipe (31);

- the inlet opening (4) is provided with a system, whereby if the rainwater flow rate flowing into the tank through the inlet opening (4) is smaller than a certain flow rate, the system is suitable for directly discharging at least a part of the rainwater flow rate carry to the buffer space;

- combinations of two or more of these details and characteristics.

The invention also relates to the use of one or more buffer systems according to the invention for regulating water flows and / or water levels in streams and / or rivers and / or canals and / or flood areas by regulating / controlling drainage flows of rainwater originating from roofs, driveways and road requirements and / or water originating from a canal, stream, canal or river, wherein rainwater and / or water flows to storage spaces of one or more buffer systems according to the invention, and wherein this rainwater and / or water flows through porous vertical concrete walls. from the water tank (s) flows to its buffer spaces, before being discharged to streams and / or rivers and / or canals and / or flood areas.

Specific embodiments of the invention will now be described as advantageous examples of the invention. Reference is made in the description to the accompanying drawings.

In those drawings, show:

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

Fig. 2 shows a view of the water tank of Fig. 1 in section along the line IIII,

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

Figs. 4 to 6 are cross-sectional views of the water tank of Fig. 3, along lines IV-IV, V-V and VI-VI,

Fig. 7 is a view of a detail of the water tank of Fig. 3,

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

Fig. 9 is a view of two water tanks connected together by pipes,

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

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

Fig. 12 is a top view of a fourth embodiment that is similar to the embodiment of Fig. 3,

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

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

Fig. 15 is a top view of a fourth embodiment,

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

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

Fig. 18 is a sectional view along the line XVIII-XVIII in Fig. 17,

Fig. 19 is a top view of a sixth embodiment of a buffer system according to the invention,

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

Fig. 21 is a sectional view of a seventh embodiment.

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

- one or more outer walls (1) made of non-porous concrete and defining a tub with an inner volume (2), a part of which serves as a storage space (3) with a storage volume for rainwater;

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

- an outlet opening (5) for draining rain water from the water tank (T);

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

- a control system (5,8) to control the drainage rate of rain water from the water tank (T).

The control system (5, 8) consists of one or more porous concrete vertical inner walls (8) that extend into the inner volume (2) of the water tank (T), to split this inner volume at least into a rainwater storage space (3) and a buffer space (9) with a buffer volume to collect water that flows through the porous concrete vertical inner wall (s) (8).

The buffer space (9) is provided with the outlet opening (5) for draining rainwater. The outlet opening is located along the bottom of the tub (T).

The porous concrete inner wall (8) is made with specially draining concrete to achieve an adapted water permeability. The 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 of 0.1 liters / m m ² / s to 1 liter / m ² / s, such as 0.2 to 0.75 liters / m ² / s. The minimum water permeability is preferably from 0.2 to 0.5 liters / m ² / s.

The water permeability of that vertical porous inner wall is measured at a storage space (3) that is free of water, while the buffer space is virtually empty. For that measurement, for example, a pump is used to keep the buffer space virtually empty.

One can also determine the maximum water permeability of the draining concrete by making a porous concrete slab that serves as the bottom of a test tub. The test tub (with a height equal to the height of the tank) will be filled with water afterwards, and the water flow rate will be measured for the water that flows through the porous bottom.

The draining concrete is preferably made by hardening a mixture of at least cement, aggregates and water, so as to preferably obtain a total open pore volume of 8 to 12% in the hardened concrete. For the concrete, aggregates with a particle size of 6 mm to 14 mm are preferably used. In general, the granules of the draining concrete contain 15% by weight of granules with a partial size greater than 8 mm, while the weight ratio xvater / cement is less than 0.5, ideally between 0.35 and 0.42.

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

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

In order to better control the water permeability of the concrete, one or more additives can be added to the uncured concrete mixture, such as aqueous polymer dispersion, in particular acrylate / methacrylate polymer / copolymer x-dispersion, such as copolymer of acrylic acid ester-vinyl ester aqueous dispersion. For example, 10 to 30% by weight of polymer dispersion can be added to the concrete, the percentage by weight being measured in relation to the cement weight.

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

The height of the tank is preferably larger than lm.

In its first embodiment (Fig. 1), the total water discharge capacity varies linearly with the water level present between 0% and 100%.

In a second embodiment, the total water drainage capacity measured at water level of half the storage space, and preferably at a water height of 0.3 m, is equal to 80% to 100%, preferably 90% to 100% of this measured with a storage room that is almost completely filled with water (3).

This feature gives you better control over the water that flows through the porous wall.

In the embodiment of Fig. 3, the porous concrete has a plurality of zones (10) with increased water permeability relative to the average water permeability of the porous concrete. Said zones (10) lie in the vicinity of the bottom, for example at a height (h) of the bottom (3B) of the storage space (3) which is smaller than 50 cm, and preferably smaller than 30 cm.

Those zones (10) can be manufactured by using aggregates with increased size. These zones can also form an intermediate layer in the porous wall, said intermediate layer being at a height between 20 and 50 cm relative to the bottom (3B).

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

The porous concrete inner wall (8) defines a porous surface facing the storage space (3), the ratio of storage volume (3) in m ³ / porous surface in m ^{2 being} between 0.5 and 1.5 (such as between 0, 7 and 1.25, preferably 0.8, 0.9, 1, 1.1 and 1.2). This ratio provides a good control of the maximum flow of water that flows through the porous wall, and a sufficient storage volume for rainwater.

The outlet opening (5) for draining rainwater has a passage which is suitable for limiting the water discharge flow through that outlet opening (5) between 1 and 201 liters / s and preferably to a maximum of 51 liters / s.

The water tank is provided with at least two separate overflows (3A, 9A), namely a first overflow (3A) for the storage space (3) for draining rainwater from the storage space, as soon as the water level in the storage space (3) reaches the level (H3A ) of that first overflow (3A), and a second overflow (9A) for the buffer space (9) for draining rainwater from the buffer space, as soon as the water level in the buffer space (9) exceeds the level (H9A) of that second overflow (9A).

Via those overflows 3A, 9A, two water tanks T, T1 according to the invention can be bound together by pipes 20,21. The tank T1, for example, is located at a lower level with respect to the tank T, as a result of which water can flow freely from tank T to tank T1. The overflow opening 3A of the tank T is connected to the inlet opening 4 of the tank T1 via the pipe 20. As soon as the storage space 3 of the tank T is full, water flows from said storage space 3 to the storage space 3bis of the tank T1. (see fig 9)

The overflow 9A of the buffer space 9 of the tank T is with an inlet 40 via the pipe 21. If the buffer space 9 of the tank T is almost full, then water flows from the buffer space of the tank T to the buffer space 9 of the tank. tank Tl. Via pipes 22, water is drained from the buffer spaces 9 from tanks T and T1 to the stream S.

The first overflow (3A) lies at least partially at a level (H3A) that is above the lowest level (H9A) of the second overflow (9A).

The first overflow (3A) has a passage area that is larger than the passage area of the second overflow (9A).

With those 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 a storm.

The porous concrete inner wall (8) has an upper side (8B) that lies at a level (H8B) that is higher than the lower edge of the first overflow (3A) and the lower edge of the second overflow (9A). This is advantageous to prevent water from flowing over the inner wall of the storage space to the buffer space 9.

In the shown embodiment of Fig. 1, the lid 6 is removably mounted on the tub 1. In that case, it is also advantageous to mount the porous concrete inner wall 8 removably in the tub. The lower edge of the wall 8 rests on the bottom of the tub, possibly with a rubber intermediate piece.

Via the manhole 7, one can have a view of the water level in both rooms (3.9). Maintenance work can also be carried out through the manhole in the cockpit.

In the embodiment of Fig. 3, the water tank comprises three or more than three separate buffer spaces (9.90, 91), namely (a) at least one first and second buffer spaces (90, 91) which are along the bottom of a storage space (3) are located, said first and second buffer spaces (90) collecting water from the storage spaces (3,30) via an at least partially horizontal porous concrete wall (80,81), and (b) at least a third central buffer space (9) cooperating with two almost vertical porous concrete walls (8,8 bis) to collect water from the storage rooms (3,30).

The position of the porous walls 80,81 along the bottom of the tub can be maintained via fixing means (bars 111).

The first and second buffer spaces are connected to the third buffer space (9) by pipes (100) located along the bottom of the water tank. Those tubes 100 show a slope with respect to a horizontal plane, as a result of which the upper edge (100A) of those tubes rises in the direction of the third buffer space (9). In this way it can be prevented that air or gas remains in the buffer spaces 90, 91, which can be disadvantageous for the passage of water.

The two separate storage rooms (3.30) are connected via an overflow pipe (3 1). That tube 31 is intended for discharging water from the first storage space (3) to the second storage space (30), as soon as the first storage space (3) is substantially water-rich, the second storage space (30) being provided with an overflow (3A) ) which is located at a level below the overflow pipe (31).

In a possible embodiment, the inlet opening (4) can be provided with a control system 400, so that if the rain water flow flowing into the tank T is smaller than a certain flow, the system 400 is adapted to directly discharge at least a part of the rain water flow to be fed to the buffer space 9. With such a system, for a short and non-stormy rain period, the rain water can be partly discharged to the storage space 3, as well as partly to the buffer space.

Such a system is shown in figures 8A and 8B. The rainwater W flows into a chamber 401 which is provided with an open inner vessel 402 to collect at least a part of the rainwater. The bottom of this vessel is provided with a hole 402A. Within this vessel a float 403 moves with a surface 403A that acts as a valve system. The inner vessel 402 is in communication with an inlet opening 40 of the buffer space 9, via a pipe 41.

For small water flows W, the water flows into the inner vessel 402. Since the flow rate is not sufficient, the float 403 remains in a lower position, so that part of the rain flows directly to the buffer space 9, while another part flows to the storage space 3 via the opening 402A. (see Fig 8A).

In the event of a rainstorm, the water level in the inner vessel rises, so that the float 403 is in a closed position, to seal the inlet of the pipe 41. In this closed position, almost all the rain flows into the storage space of the tank T.

A third embodiment of a water tank according to the invention is shown in FIG.

The tank T comprises a concrete tub (watertight) with a spout 5 along the bottom 1B. Along the bottom IB, the tank is provided with one or more supporting elements IC for a plate 80 of porous concrete. The round plate 80 supports itself or the supporting elements IC. Above the plate 80 there is cylindrical pipe 82 of porous concrete.

The plate 80 can optionally be provided with a hole 80G to connect the buffer zones 9,90 together. If that plate 80 is not provided with the hole 80G, the buffer spaces are connected via the open pores of the 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 via intermediate elements 110 which are situated between the upper edge of the pipe 82 and the lower surface of the cover.

Figures 12 and 13 are views of an embodiment similar to the embodiment of Figures 3 to 6, unless a few modifications.

The tub and / or the vertical porous walls 8, 8 bis are provided with support elements IC for porous plates 80, 81. The position of the plates on the support elements IC is maintained by the use of fastening means 111 which, for example, are partially in a wall of the tub are applied.

Fig. 14 is a view of a canal or canal 200, with a dam

201 and two inspection paths 202,203. Along the inspection path 203, several water tanks have been installed according to the design. The water tank 1 is in communication with the channel 200 via the pipe 204. The storage spaces of the water tanks 1, Ibis, Iter, etc. are connected, so that water can be discharged from the storage space of tank 1 to the storage space of tank Ibis, as soon as the water level in storage space 3 of tank 1 exceeds a certain level.

The outlets 5 of all tanks 1, Ibis, etc. are connected to an outflow pipe 205 to drain water back into the channel, after the dam 201.

The water tanks according to the invention can thus be used to control the water level in the channel. As soon as the water level exceeds a maximum level, the water tanks 1, Ibis, etc. can collect water from the channel and drain it back into the channel with a delay, which offers a solution against storm water (with heavy rain in a short time).

Since the water tanks can be located under inspection paths, the construction of those tanks can be carried out with the installation of those inspection paths.

Figs. 15 to 21 are views of embodiments of buffer systems according to the invention.

In the embodiment of Fig. 15 and Fig. 16, the buffer system comprises a rectangular tank T with a vertical porous concrete inner wall (8), which divides the inner volume of the tank into a storage space (3) and into a buffer space (9).

The tank T is also provided with an inlet opening (4) which is at a level higher than the upper level of the inner wall (8), whereby in the event of storm water, water can flow directly into the buffer space (9). Storm water can then be discharged via an overflow pipe (51) which is connected to the outlet opening (5).

The outlet opening (5) is connected to a porous concrete element (85) via a horizontal pipe (86) (which is at a distance from the bottom of the buffer space). The porous concrete element (85) defines an inner chamber (87) (to collect water that is connected through the porous walls of the element (85)) via a pipe system (86) to the outlet opening (5). The porous concrete element is at least partially made from a hardened porous water-draining concrete that is made by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water around an open pore volume of 8 to 12% in the hardened porous water-draining concrete.

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

The embodiment of figures 17 and 18 is similar to the embodiment of figures 15 and 16. The buffer system of figures 17 and 18 comprises a water tank (T), the buffer space of which is connected to a buffer tank (BT) through a connecting pipe 55. The connecting pipe 55 is at a level above 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 an outlet opening (50) which is situated above the bottom of the buffer tank, the outlet opening (50) being connected to a passage system suitable for limiting the water discharge through that outlet opening (50) between 1 and the 201iter / s and preferably up to a maximum of 51iter / s. The passage system comprises a porous concrete element (85) with an inner chamber (87) which is connected to the outlet opening (50) via a pipe system (86). The porous concrete element is at least partially made from a hardened porous water-draining concrete that is made by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water around an open pore volume of 8 to 12% to be obtained in the hardened porous water-draining concrete.

The porous concrete element rests on the bottom of the buffer space (9a) or of the buffer tank (BT), wherein the porous concrete element (85) contains one or more porous walls, as well as a porous top side, and wherein, preferably, the pipe system 86 is 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 an upper level (for example the level of the inner wall (8)).

The buffer system of figures 19 and 20 is similar to the buffer system of figures 17 and 18, unless the pipe 51 is connected to the inner chamber (87) of the porous element (85).

Fig. 21 shows a buffer system with a plurality of tanks T1, T2, etc. to collect rainwater, which are connected together. These tanks are therefore connected to a buffer system according to the invention to control the water discharge (water tank (T) with porous vertical inner wall (8) and buffer tank (BT) with element (85)).

Claims (13)

CONCLUSIONS A rainwater / water buffer system comprising at least one water tank (T) for collecting rain water / water, the water tank (T) comprising at least: - one or more outer walls (1) made of non-porous concrete and defining an inner volume (2), a part of which serves as storage space (3) with a storage volume for rainwater / water; - an inlet opening (4) through which rainwater / water can flow into the storage space (3); - an outlet opening (5) for draining rainwater / water from the water tank (T); - a lid (6) with a manhole (7); and - a control system (5,8) for controlling the discharge rate of rainwater from the water tank (T), characterized in that the control system (5,8) consists of at least one or more porous concrete vertical inner walls (8) extending in the inner volume (2) of the water tank (T), and which divides this inner volume at least into a rainwater / water storage space (3), and a buffer space (9) with a buffer volume to collect water flowing through the porous concrete vertical inner wall (8) flows, characterized in that the buffer space (9) is provided with the outlet opening (5) for draining rainwater / water, and characterized in that the porous concrete vertical inner wall (s) (8) are manufactured is / are from a hardened porous water-draining concrete that is produced by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water to obtain an open pore volume of 8 to 12% in the hardened porous water drainer and the concrete, wherein the hardened porous water-draining concrete has a water permeability of 0.05 liters / m ² / s to 5 liters / m ² / s, preferably from 0.1 liters / m ² / s to 3 liters / m ² / s, preferably between 0.1 and 1 liter / m ² / s, wherein this water permeability is measured at a storage area (3) that is almost completely filled with water and an empty buffer area (9). Buffer system according to claim 1, wherein the water tank (T) has a height (H) of less than 3 m, characterized in that the total water drainage capacity measured at water height of half the storage space (3), and preferably also at a water level water height of 0.3 m in the storage space (3), equal to 80% to 100%, preferably 90% to 100% of this measured at a storage space (3) that is almost completely filled with water. Buffer system according to claim 1 or 2, characterized in that the hardened porous water-draining concrete has one or more zones with increased water permeability relative to the average water permeability of the hardened porous water-draining concrete, said zone or zones (10) lying / lying at a height (h) from the bottom (3B) of the storage space (3) that is smaller than 50 cm, preferably smaller than 30 cm. A buffer system according to any 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 most preferably between 5 and 20 . A buffer system according to any one of the preceding claims, characterized in that the porous concrete inner wall (s) (8) of the water tank (T) defines / defines a porous surface facing the storage space (3), wherein the storage volume ratio ( 3) in m ³ / porous surface in m ^{2 is} between 0.5 and 1.5. A buffer system according to any one of the preceding claims, characterized in that the buffer system has an outlet opening (5) for draining rainwater, wherein as long as the water level in the storage space (3) is lower than a maximum water level, the outlet opening (5) is provided is with a passage system suitable for limiting the water discharge flow through that outlet opening (5) between 1 and 201iter / s and preferably up to a maximum of 51iter / s, wherein the passage system comprises a porous concrete element with an inner chamber which via a pipe system is connected to the outlet opening (5), and wherein the porous concrete element is at least partially made from a hardened porous water-draining concrete that is produced by hardening a mixture of at least cement, aggregates with particle sizes from 6 mm to 14 mm, and water to obtain an open pore volume of 8 to 12% in the hardened porous water-draining concrete. A buffer system according to any one of the preceding claims, characterized in that the water tank is provided with a substantially vertical porous concrete inner wall (8) which splits the inner volume of the water tank into a storage space (3) and into a buffer space (9), wherein the buffer space (9) of the water tank (T) is connected via a connecting pipe to a buffer tank (BT), said connecting pipe located at a level above the bottom of the buffer space (9) and above the bottom of the buffer tank, and wherein the buffer tank is provided with an outlet opening (50) located above the bottom of the buffer tank, wherein the outlet opening (50) is provided or connected to a passage system suitable for limiting the water discharge flow through that outlet opening (50) between the 1 and 201iter / s and preferably up to a maximum of 51iter / s, wherein the passage system comprises a porous concrete element with an inner chamber which is connected to the outlet opening (50) via a pipe system and wherein the porous concrete element is at least partially made from a hardened porous water-draining concrete that is made by hardening a mixture of cement, aggregates with particle sizes from 6 mm to 14 mm, and water around an open pore volume of 8 to 12% to be obtained in the hardened porous water-draining concrete. Buffer system according to claim 6 or 7, characterized in that the porous concrete element rests on the bottom of the buffer space (9) or of the buffer tank (BT), wherein the porous concrete element comprises one or more porous walls, as well as a porous top side, and wherein, preferably, the pipe system is provided with an overflow system for discharging water as soon as the water level in the buffer space or in the buffer tank exceeds an upper level. Buffer system according to one of the preceding claims, characterized in that the water tank or the water tank with buffer tank is provided with two separate overflows (3A, 9A), namely a first overflow for the storage space of the water tank for draining rainwater as soon as the water level in the storage space (3) exceeds the level (H3A) of that first overflow (3A), and a second overflow (9A) for the buffer space (9) or for the buffer tank (BT) for draining rainwater as soon as the water level in the buffer space (9) or in the buffer tank (BT) exceeds the level (H9A) of that second overflow (9A). A buffer system according to any 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 of a storage space (3), said first buffer space (90) ) collects water from the storage space (3) via an at least partially horizontal porous concrete wall (80), and at least a second buffer space (9) which cooperates with a substantially vertical porous concrete wall (8) for 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 tube or channel (100), which is preferably located along the bottom of the water tank. Buffer system according to claim 10, characterized in that the water tank (T) has at least two separate storage spaces (3.30), said two separate storage spaces (3.30) being connected via an overflow pipe (31) intended for water by passing from a first storage space (3) to a second storage space (30), as soon as the first storage space (3) is substantially water-filled, the second storage space (30) being provided with an overflow (3A) which is situated at a level which lies under the overflow pipe (31). A buffer system according to any one of the preceding claims, characterized in that the inlet opening (4) is provided with a system whereby as a result of the rain water flow flowing into the tank through the inlet opening (4) being smaller than a certain flow rate, the system is appropriate is to discharge at least part of the rainwater flow directly to the buffer space (9) of the water tank. 13. Use of one or more buffer systems according to one of the Preceding claims for regulating water flows and / or water level in streams and / or rivers and / or canals and / or flood areas by regulating drainage flows of rainwater from roofs, driveways and road requirements and / or water from a canal, stream , canal or river, where rainwater and / or water to storage spaces of one or more Buffer systems according to any one of the preceding claims, and wherein this rainwater and / or water flows through porous concrete vertical inner walls of the water tank to buffer spaces thereof, before being drained to streams and / or rivers and / or canals and / or flood areas. y — y <jMWr 30G