Rainwater reuse system

Abstract

A device for reusing rainwater collected in a rainwater tank (1), wherein the installation comprises at least: * at least one intermediate tank (2) made of partially porous concrete, equipped with a water pump (24) and a water level measuring system (25) to determine at least a lower water level (25A) and an upper water level (25B) in the intermediate chamber (TK); * at least one passage (26) formed in at least one concrete side wall (22) and / or in the concrete cover (23) of the intermediate tank; * an inlet pipe system (27) for collecting water from an external water supply (50) and conveying it into the intermediate chamber (TK); and * a discharge pipe system (24A) associated with the water pump (24). (Fig. 1)

Description

Title of the invention: Device for reusing rainwater

[0001] The invention relates to a device for reusing rainwater collected in an inner chamber of a rainwater tank.

[0002] To reuse rainwater from a cistern for a number of household tasks, it is known to have a water pump submerged in the cistern, this water pump being connected to a separate water circuit, in order to use, for example, the rainwater for toilets, washing machines, etc. of a home. Such a water pump is equipped with a filter element that becomes clogged quickly. Indeed, this water pump or submersible pump is located at the bottom of the rainwater cistern. The filter element must therefore be cleaned regularly. For this cleaning, the water pump with the filter element must be removed from the rainwater cistern.

[0003] Since there must be a complete separation between a rainwater circuit and a city water circuit, the rainwater tank is filled with city water or drinking water as soon as there is no longer enough water in the rainwater tank. Large volumes of city water or drinking water are then required to raise the water level in the rainwater cistern sufficiently so that the rainwater circuit can continue to be used. This has the disadvantage of stirring up sludge, pumping out sludge, contaminating the rainwater circuit, using too much city water, overfilling the rainwater cistern with city water, having the tank or cistern almost full before a major storm, etc.

[0004] Filling a rainwater tank with tap water is not so simple. Indeed, the bacteria present in the water in the tank must not contaminate the tap water circuit. Any risk of such pollution must be avoided.

[0005] With increasingly long periods of drought, the use of a rainwater circuit to supply toilets or washing machines in one or more homes is becoming increasingly problematic, hence its discontinuation. If there is a lack of water in a rainwater tank, the sludge can harden, preventing the water pump, its filter or the non-return valve from functioning properly.

[0006] US8354021 describes a rainwater harvesting device, wherein the device includes at least: * an at least partially porous intermediate tank adapted to be placed in the inner chamber of a rainwater tank, wherein said intermediate tank is defined at least between a bottom, at least one side wall and a cover to form an intermediate chamber, wherein the side wall comprises at least one porous portion, through which, once the water level is above a certain level in the inner chamber, rainwater flows out the inner chamber to the intermediate chamber through the porous portion of the side wall, wherein the intermediate chamber is equipped with a water pump, wherein said water pump is located in the intermediate chamber, * at least one passage formed by at least one side wall and / or the cover and / or between at least one side wall and the cover, and * a discharge or vent pipe system associated with the pump, the vent pipe system being associated with one of the passages.

[0007] Other rainwater collection devices are described in documents DE10120410 and DE9413907U.

[0008] Patent FR3083251 discloses a rainwater tank serving as a buffer system, this rainwater tank for collecting and temporarily storing rainwater, but also for evacuating water from the tank in a controlled manner. To do this, the tank comprises at least one inner wall made of draining porous concrete to define in the tank, a storage volume and a buffer volume associated with a discharge opening. The at least one interior wall of porous permeable concrete is manufactured by curing a mixture comprising at least cement, aggregates with a grain size of 6mm to 14mm inclusive and water, to obtain an open pore volume of 8 to 12% in the cured porous permeable concrete, the cured porous permeable concrete having a water permeability of 0.05 litres / m2 / s to 5 litres / m2 / s, this permeability being measured for a nearly full storage space and a substantially empty buffer space.

[0009] The subject of the invention is a device making it possible to respond to one or more of the problems described above.

[0010] The device according to the invention is a device for reusing rainwater collected in an inner chamber (B) of a rainwater tank (1), preferably a concrete rainwater tank.

[0011] The device comprises at least:

[0012] * an intermediate tank (2) made of at least partially porous concrete, suitable for be placed in the inner chamber (B) of the rainwater tank (1) or as part of the rainwater tank (1) to be located in its inner chamber (B). This is advantageous because the position of the intermediate tank along the bottom of the rainwater tank is maintained. This intermediate tank will not move due to a rapid arrival of a large amount of rainwater into the rainwater tank.

[0013] This intermediate tank (2) is defined at least between a bottom (11.21), at least one side wall (12.22) and a cover (23) to form an intermediate chamber (TK), in which the side wall (12.22) and / or the cover (23) comprise / contain at least one porous part (22A, 23A), whereby as soon as the water level (P) in the inner chamber (B) of the rainwater tank (1) is above a certain level (PI), rainwater flows from the inner chamber (B) into the intermediate chamber (TK) through the porous part (22A, 23A) of the side wall (22) and / or the cover (23).

[0014] The intermediate tank (2) is equipped with a water pump (24), said water pump (24) being located in the intermediate chamber (TK).

[0015] * at least one passage (26) formed in the at least one side wall (22) and / or in the cover (23) and / or between the at least one side wall (22) and the cover (23), and

[0016] * a discharge pipe system (24A) associated with the water pump (24), the system discharge pipe (24A) being associated with one of the at least one passage (26).

[0017] The device according to the invention is essentially characterized in that:

[0018] * the bottom (11,21), the at least one side wall (12,22) and the cover (23) are in concrete,

[0019] * the device comprises:

[0020] - a water level measuring system (25) for determining at least one level lower water level (25A) and an upper water level (25B) in the intermediate chamber (TK),

[0021] - an inlet pipe system (27) associated with one of the at least one passage (26), in which the inlet pipe system (27) is adapted to collect water from an external water source (50) and to bring it into the intermediate chamber (TK);

[0022] wherein the porous portion (22A, 23A) of the at least one side wall (22) and / or the cover (23) is a hardened porous draining concrete portion defining a total volume of porous concrete between a first face (231) facing the intermediate chamber (TK) and a second face (232) opposite the first face (231) and intended to be facing the inner chamber (B), wherein said hardened porous draining concrete is manufactured by curing a mixture comprising at least cement, aggregates with a grain size of 6 mm to 14 mm inclusive and water to obtain a volume of open pores forming open channels extending between said first face (231) and said second face (232) of said porous draining concrete portion, said volume of open pores corresponding to 5% to 25%, preferably 10% to 25% of the total volume of porous concrete, said open channels extending between the first face (231) and said second face of the porous part (22A,23A) defining a water permeability of 0.1 litre / m2 / s to 5 litres / m2 / s, this water permeability being measured with a water level of 1 metre above the porous part (22A, 23A) and with a water level in the intermediate chamber (TK) maintained at a level lower than said lower water level (25A) of the intermediate chamber (TK).

[0023] The pervious concrete is preferably made by curing a mixture of cement, aggregates and water to preferably obtain a total open pore volume of 8 to 12% inclusive in the dry cured concrete. For the concrete, aggregates with a particle size of 6 mm to 14 mm inclusive are preferably used. Preferably, the aggregates of the pervious concrete contain 15% by weight of aggregates with a particle size greater than 8 mm, while the water / cement weight ratio is less than 0.5 and ideally between 0.35 and 0.42. The uncured (water-free) concrete mix contains less than 30% by weight of aggregates, more preferably between 25 and 27% by weight with a particle size of less than 4 mm. The concrete mix may also contain one or more additives. The uncured (water-free) concrete mix may contain up to 15% by weight of sand, with a grain size of less than 4 mm, for example 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.

[0024] In order to further control the water permeability of the concrete, one or more additives may be added to the concrete mix, such as an aqueous polymer dispersion, in particular an aqueous acrylate / methacrylate polymer / copolymer dispersion, for example a copolymer of an aqueous acrylic acid ester / vinyl ester dispersion. For example, 10 to 30% by weight of a polymer dispersion may be added to the concrete, this percentage by weight being measured relative to the weight of cement.

[0025] The porous draining concrete part thus serves as a filter for the rainwater contained in the rainwater tank. There is thus no risk of the sludge contaminating the intermediate tank, because the water from the rainwater tank can only flow into the intermediate tank if the water level in the rainwater tank exceeds a minimum level. The sludge present at the bottom of the tank remains moist for longer, which is advantageous for preventing the formation of dry particles, these particles forming a stable suspension when the rainwater tank is refilled with rainwater, in particular storm water.

[0026] The intermediate tank (2) is equipped with a water pump (24) and a water level measuring system (25) for determining at least a lower water level (25A) and an upper water level (25B) in the intermediate chamber (2), the water pump (24) and the water level measuring system (25) being located in the intermediate chamber (TK).

[0027] The passage or passages between a concrete side wall and the concrete cover is / are advantageous, since the cover (in particular the porous concrete cover) can be executed without openings.

[0028] The external water supply may be a city water supply, but may also be water from another rainwater tank, in particular from an intermediate tank (2) of another rainwater tank (1).

[0029] With such water permeability for the draining porous concrete part, particles are not trapped in the open channels of the porous concrete part, which facilitates its cleaning. The cleaning itself can be achieved by filling the rainwater tank with rainwater, removing the particles along the second side. The particles present in the open channels can be removed by using city water or air supplied to the intermediate tank.

[0030] By percolating rainwater through the porous concrete section to the intermediate chamber, the pH of the rainwater is raised to 6.5 - 7.5, making the water flowing to the rainwater circuit less aggressive.

[0031] According to embodiments of the invention, the device has one or more of the following characteristics:

[0032] * along the second face (232), the draining porous concrete part (23A) is provided with a filter fabric or a filter membrane (30).

[0033] * the porous draining concrete part (22A, 23A) has a dry weight, and

[0034] at least 5% of the total volume of the porous draining concrete part is formed by open channels between the first face (231) and the second face (232) with an average hydraulic diameter D of 100pm to 1000pm (such as advantageously from 200 to 600pm, such as 200pm, 300pm, 400pm, 500pm), where the average hydraulic diameter is determined by the following formula:

[0035] D = 4 x WW / BET

[0036] where: WW is the free volume of the open channels of the draining porous concrete portion through which water can flow between the second face (232) and the first face (231), said free volume being expressed per unit of dry weight of the draining porous concrete portion, this free volume expressed per unit of dry weight being measured after allowing water to percolate into the draining porous concrete portion through the second face so that the entire free volume of the open channels is filled with water, and after determining the volume of water that can be extracted through the first side, said volume of water thus determined then being divided by the dry weight of the draining porous concrete portion, this free volume of water per unit of weight being expressed in cm3 / g of the dry draining porous concrete portion;

[0037] BET is the BET (Brunauer, Emmett and Teller) specific surface area expressed in cm2 / g of the dry draining porous concrete part.

[0038] * the filter fabric or the filter membrane (30) has open pores of a diameter greater than the average hydraulic diameter D of the open channels of the draining porous concrete part (23A). Preferably, said filter fabric or said membrane filtering fabric (30) has at least two filter layers (30A, 30B), in which a first filter layer (30A) having open pores of a first average diameter DI is directed towards the second face (232) of the porous draining concrete portion (23A) relative to a second filter layer (30B) having open pores of a second average diameter D2, in which the second average diameter D2 (advantageously from 500 pm to 1000 pm) is larger than the first average diameter DI (advantageously from 200 pm to 500 pm). Preferably, the filter fabric or the filter membrane is flexible and / or soft and / or elastic.

[0039] * the concrete cover (23) is at least partially porous, the concrete cover (23) being removable from the at least one concrete side wall (22). The intermediate tank (TK) can then be opened by lifting the cover (23). This then provides easy access to the intermediate tank chamber.

[0040] * the device is provided with an air hose system (40) associated with at least one of a passage (26), wherein the air pipe system (40) has a first open end (40A) located in the intermediate chamber (TK), wherein a second end (40B) of the air pipe system (40) is intended to be connected to a ventilation system (41) and / or to an air supply device (42). The air pipe system (40) can be used to ventilate the intermediate chamber (TK), for example as a vent, when filling the intermediate chamber with rainwater or city water, to fill the intermediate chamber with air, in particular to ensure air to circulate through the open channels of the draining porous concrete part, for example to push particles out of the open channels or out of the filter fabric (and thus to clean the open channels and / or the filter fabric or membrane).An air supply to the intermediate chamber also ensures oxygenation of the rainwater present in the inner chamber (B) of the tank (2), which is beneficial for the color of the rainwater, as well as for its odor.

[0041] Advantageously, the inlet pipe system (27) is provided with a filter element (27A) and / or a non-return valve (27B), wherein the inlet pipe system is preferably also provided with a water collection system (27C) arranged separately from the external water supply (50) and adapted to collect a waterfall or a discharge of water from the external water supply (50). This avoids a direct connection between the external water supply and the inlet pipe system, and thus prevents bacteria present on the inlet pipe system from contaminating the external water supply.

[0042] * the device also comprises one or more of the following elements:

[0043] - an electrical system (60) for supplying electricity to the water pump (24), and / or - a regulation system (70) receiving signals from the water level measuring system (25) and sending regulation signals to a control system (50A) of the external water supply (50), wherein if the water level in the intermediate chamber (TK) is lower than said lower level of the intermediate chamber (TK), the regulation system (70) sends a signal to the control system (50A) to allow water to flow into the intermediate chamber (TK) through the inlet pipe system (27), while if, at least after water has been supplied into the intermediate chamber (TK) through the inlet or supply pipe system (27), the water level in the intermediate chamber (TK) exceeds the upper water level (25B) of the intermediate chamber (TK),the regulation system (70) issues a signal to the control system (50A) so that no water from the external water supply flows into the intermediate chamber (TK) through the inlet pipe system (27), and / or,

[0044] - a water level measuring system (80) for measuring the water level in the inner chamber (B), as well as a control system (70) which receives signals from the water level measuring system (80) of the inner chamber (B) and from the water level measuring system (25) of the intermediate chamber (TK), wherein depending on these signals, the control system (70) determines a parameter of the water permeability of the permeable porous concrete part (23A), wherein, if this determined permeability parameter corresponds to a water permeability lower than a minimum value, the control system (70) issues a signal to allow water and / or air to flow into the intermediate chamber (TK) through the inlet pipe system (27) and / or the air pipe system (40), thereby allowing water and / or air to pass from the intermediate chamber (TK) to the inner chamber (B) through the permeable porous concrete part (22A, 23A), and / or

[0045] - a sterilization system placed in the intermediate tank or its chamber (TK). The sterilization system serves to at least partially sterilize the water in the intermediate tank. This is particularly advantageous during a cleaning step of the open channels of the porous concrete part.

[0046] Preferably, the sterilization system comprises at least one UV lamp, preferably with UV-C radiation. With such a UV lamp, the risk of infection by bacteria is reduced.

[0047] The UV lamp is mounted in the intermediate tank, which places it in a protected environment. The UV lamp therefore only has to treat the water in the intermediate tank.

[0048] The UV lamp is advantageously mounted on the cover, for example along the face directed towards the chamber of the intermediate tank. The power supply to the UV lamp can be provided by means of an electric wire passing through a passage (26). The UV lamp can also be mounted on the water pump. The UV lamp is preferably removably mounted in the intermediate tank, to facilitate its replacement.

[0049] - a concrete rainwater tank (1) provided with at least one inner wall made of concrete (12) along its bottom (11), wherein said at least one concrete inner wall (12) of the tank is adapted to form a support for an at least partially porous concrete cover (23), wherein the intermediate chamber (TK) is defined by the at least partially porous concrete cover (23) and the at least one concrete inner wall (12).

[0050] * the concrete cover (23) is provided with one or more openings (23B) for forming at least one passage (26) for the inlet pipe system (27), for the discharge pipe system (24A) and, preferably, for the air pipe system (40), and preferably also for the sterilization system, wherein this or these openings (26) are provided with a sealant (26A) to prevent water from the inner chamber (B) from flowing through this or these openings (26) to the intermediate chamber (TK), and water from the intermediate chamber (TK) from flowing through this or these openings (26) to the inner chamber (B).

[0051] Preferably, the concrete cover is a porous draining concrete cover (23) having a substantially flat lower surface (231), wherein the inlet pipe system (27) has a free end (27D) remote from the substantially flat lower surface (231) for extending into the intermediate chamber (TK) and / or preferably, the air pipe system (40) has a free end (40A) remote from the substantially flat lower surface (231) for extending into the intermediate chamber (TK).

[0052] In this way, a free volume can be formed in the intermediate chamber, along the lower face (231) of the cover (23), this free volume then forming a buffer volume suitable for collecting air or gas, this air or gas being for example released from rainwater. This air or gas released into the intermediate chamber (TK) can then pass through open channels of the porous cover, which is advantageous for cleaning purposes.

[0053] * the concrete cover (23) has an opening (23B) forming a passage (26) at least for a part of the discharge pipe system (24A) and the water pump (24), wherein said opening (23B) is connected to a substantially vertical tube (90) forming an extension of the intermediate chamber (TK) in which the substantially vertical tube (90) forms a channel adapted to introduce (lower) a part of the discharge pipe system (24A) and the water pump (24) into the intermediate chamber (TK), wherein said substantially vertical tube (90) has an upper opening (90A) adapted to be preferably located above a water level maximum in the inner chamber (B) to prevent water from the inner chamber (B) from flowing through said upper opening (90A) into said substantially vertical tube (90).

[0054] Advantageously, said substantially vertical tube (90) is at least partially porous, in particular at least partially made of porous draining concrete.

[0055] * the intermediate tank has a volume of between 10 and 200 liters, preferably between 30 and 100 litres. Such a volume is sufficient to form an adequate buffer water volume to ensure a continuous supply of rainwater to one or more toilets and one or more washing machines. When rainwater is consumed outside the tank, the tank is filled either with rainwater from the rainwater tank (1) continuously as long as the water level in the tank (1) is sufficient, or with water from an external water source, if the water level in the tank (1) is not sufficient to ensure adequate filling of the intermediate tank (2).

[0056] * combinations of two or more of these characteristics

[0057] The invention also relates to the use of a device according to the invention, for reusing rainwater collected in an inner chamber (B) of a rainwater tank (1), in which the water can flow from the inner chamber (B) to the intermediate chamber (TK) through the at least porous part of the side wall (12, 22) and / or the cover (23), in which the at least porous part forms a filtering element for the water flowing from the inner chamber (B) to the intermediate chamber (TK). The device allows oxygenation of the rainwater present in the inner chamber (B) of the rainwater tank or cistern. To achieve such oxygenation, air is brought into the intermediate chamber (TK) of the intermediate tank (2) so that this air passes through the porous part before being released into the rainwater present in the inner chamber (B).

[0058] Details and characteristics of the invention will result from the following description of advantageous embodiments according to the invention, in which reference is made to the attached drawings. These embodiments are given by way of example only.

[0059] In these drawings: - [Fig.l] is a sectional view of a rainwater cistern provided with an intermediate tank made of at least partially porous concrete; - [Fig.2] is a sectional view, on a larger scale, of the intermediate tank of [Fig.l], - [Fig.3A] and [Fig.3B] are sectional views of another embodiment of an intermediate tank; - [Fig.4] is a top view of the intermediate tank of figures 3A and 3B, after removal of the cover; - [Fig.5] is a sectional view of a rainwater tank with two inner walls, without the porous cover - [Fig.6] is a top view of the rainwater tank of [Fig.5], after removal of the upper part of the rainwater tank, but with the porous cover resting on the interior walls; - [Fig.7] is a sectional view of the rainwater tank of [Fig.5], with a porous concrete cover resting on the edges of the interior walls; - [Fig.8] is another sectional view, on a larger scale, of the intermediate tank of the rainwater cistern of [Fig.7]; and - [Fig.9] is a schematic view of a system for controlling the operation of a rainwater tank.

[0060] The same references are used in the drawings to designate identical elements or elements having a similar function.

[0061] The rainwater tank 1 comprises a concrete tank, with a concrete bottom 11, concrete side walls 12 (with an upper part 12A made of porous concrete permeable to water), a concrete top plate 13 with a manhole or opening 91 closed by means of a steel plate 91A, said tank being provided with an inlet pipe 92 and an outlet pipe 93. The rainwater is discharged as soon as the water level in the inner chamber (B) is higher than the lower level of the porous upper part 12A of the side walls 12, and in particular via the outlet pipe as soon as the water level in the tank reaches the level of the outlet pipe 93.

[0062] The porous upper portion 12A of the side walls 12 allows a portion of the collected rainwater to infiltrate into the ground in which the rainwater tank is placed.

[0063] The rainwater tank 1 is equipped with a device 100 according to the invention, thanks to which the rainwater can be reused, for example to supply the toilets with rainwater.

[0064] The device comprises at least:

[0065] * an intermediate tank (2) made of at least partially porous concrete, adapted to be placed in the inner chamber (B) of the rainwater tank (1). This is advantageous because the position of the intermediate tank along the bottom of the rainwater tank is maintained during operation of the water pump. This intermediate tank will also not move due to the rapid arrival of large quantities of rainwater into the rainwater tank, for example during periods of thunderstorms.

[0066] This intermediate tank (2) is defined at least between a concrete bottom (21), at least one concrete side wall (22) and a concrete cover (23) to form an intermediate chamber (TK), wherein the concrete side wall (22) and the concrete cover (23) comprise / contain at least one porous concrete portion (22A, 23A) so that when the water level (P) in the inner chamber (B) of the rainwater tank (1) is above a certain level (PI), rainwater flows from the inner chamber (B) to the intermediate chamber (TK) through the porous concrete portion (22A, 23A) of the side wall (22) and the cover (23). The porous concrete portion thus serves as a filter for the rainwater contained in the rainwater tank.There is no risk of the sludge (SL) contaminating the intermediate tank (TK), because the water from the rainwater tank can only flow into the intermediate tank if the water level in the rainwater tank exceeds a minimum level (PI). (The level PI is distant from the bottom 11 by a distance of 10cm to 50cm (e.g. 15cm, 20cm, 25cm, 30cm, 40cm, etc.). The sludge SL present along the bottom 11 of the water tank (1) remains wet for a longer period, which is advantageous to avoid the formation of dry particles, these dry particles forming a stable suspension, once the rainwater tank is refilled with rainwater, especially with storm water.

[0067] The intermediate tank (2) is equipped with a water pump (24) and a water level measuring system (25) (e.g. with a lower float 25A and an upper float 25B) for determining at least a lower water level (25A) and an upper water level (25B) in the intermediate chamber (TK), the water pump (24) and the water level measuring system (25) being located in the intermediate chamber (TK).

[0068] * at least one passage (26) formed in the porous concrete cover (23).

[0069] * a water inlet or supply pipe system (27) associated with one of the at least one passage (26), wherein the inlet pipe system (27) is adapted to collect water from an external water supply (50) and to bring it into the intermediate chamber (TK). This external water supply (50) may be a city water supply, but may also be water from another rainwater tank.

[0070] * A discharge pipe system (24A) associated with the pump (24), wherein the drain pipe system (24A) is associated with at least one passage (26). This drain pipe system (24A) and this pump (24) are intended to supply directly or with the interposition of a pressure tank, a rainwater supply circuit of a dwelling, for example to supply rainwater to toilets, washing machines, watering systems, etc.

[0071] The porous concrete portion 22A, 23A is manufactured by curing a mixture comprising at least cement, aggregates with a grain size of 6 mm to 14 mm inclusive and water to obtain a volume of open pores forming open channels extending between said first face (231) and said second face (232) of said draining porous concrete portion, said volume of open pores corresponding to 5% to 25%, preferably to 10% to 25% of the total volume of porous concrete, said open channels extending between the first face (231) and said second face of the porous portion (22A, 23A) defining a water permeability of 0.1 liter / m2 / s to 5 liters / m2 / s, this water permeability being measured with a water level of 1 meter above the porous portion (22A, 23A) and with a water level in the intermediate chamber (TK) maintained at a level lower than said lower water level (25A) of the intermediate chamber (TK).

[0072] The pervious concrete is preferably made by curing a mixture of cement, aggregates and water to preferably obtain a total open pore volume of 8 to 12% inclusive in the dry cured concrete. For the concrete, aggregates with a particle size of 6 mm to 14 mm inclusive are preferably used. Preferably, the aggregates of the pervious concrete contain 15% by weight of aggregates with a particle size greater than 8 mm, while the water / cement weight ratio is less than 0.5 and ideally between 0.35 and 0.42. The uncured (water-free) concrete mix contains less than 30% by weight of aggregates, more preferably between 25 and 27% by weight with a particle size of less than 4 mm. The concrete mix may also contain one or more additives. The uncured (water-free) concrete mix may contain up to 15% by weight of sand, with a grain size of less than 4 mm, for example 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 may be added to the uncured concrete mix, such as an aqueous polymer dispersion, in particular an aqueous dispersion of acrylate / methacrylate polymer / copolymer, for example a copolymer of an aqueous dispersion of acrylic acid ester / vinyl ester. For example, 10 to 30% by weight of a polymer dispersion may be added to the concrete, this percentage by weight being measured relative to the weight of cement.

[0073] With such water permeability, the particles present in the inner chamber (B) are not trapped in the open channels of the porous concrete part (22A, 23A), which facilitates its cleaning. The cleaning itself can be achieved by filling the rainwater tank with rainwater, removing the particles along the second side (232). Any particles present in the open channels of the porous concrete or the filter fabric can be removed by supplying the intermediate chamber (TK) with tap water or air, to generate a flow of water or air from the intermediate chamber (TK) to the inner chamber (B).

[0074] By percolating rainwater from the inner chamber (B) through the porous concrete portion (22A, 23A) into the intermediate chamber, the pH of the rainwater in the intermediate chamber is raised to 6.5 - 7.5, which makes the water flowing into the rainwater circuit less aggressive. Percolation of rainwater through the porous concrete portion (22A, 23A) also oxygenates the rainwater flowing into the intermediate chamber.

[0075] Along the second side (232), the porous concrete portion (22A, 23A) is provided with a filter fabric or a filter membrane (30).

[0076] At least 5% of the total volume of the porous draining concrete part is formed by open channels between the first face (231) and the second face (232) with an average hydraulic diameter D of 100pm to 1000pm, where the average hydraulic diameter is determined by the following formula:

[0077] D = 4 x WW / BET

[0078] Where: WW is the free volume of the open channels of the draining porous concrete portion through which water can flow between the second face (232) and the first face (231), said free volume being expressed per unit of dry weight of the draining porous concrete portion, this free volume expressed per unit of dry weight being measured after allowing water to percolate into the draining porous concrete portion through the second face so that the entire free volume of the open channels is filled with water, and after determining the volume of water that can be extracted through the first side, said volume of water thus determined then being divided by the dry weight of the draining porous concrete portion, this free volume of water per unit of weight being expressed in cm3 / g; and

[0079] BET is the BET (Brunauer, Emmett and Teller) specific surface area expressed in cm2 / g of the dry draining porous concrete part.

[0080] The filter fabric or filter membrane (30) has open pores whose diameter is greater than the average hydraulic diameter D of the open channels of the porous concrete part (23A).

[0081] The filter fabric or filter membrane (30) advantageously has at least two filter layers (30A, 30B), wherein a first filter layer (30A) with open pores having a first average diameter DI is directed toward the second face (232) of the porous concrete portion (23A) relative to a second filter layer (30B) with open pores having a second average diameter D2, wherein the second average diameter D2 (for example, between 500pm and 1000pm) is larger than the first average diameter DI (for example, between 200pm and 500pm). The filter fabric or filter membrane is preferably flexible and / or elastic and / or supple.

[0082] The concrete cover (23) is removable from the concrete side wall (22). The intermediate tank (TK) can then be opened by lifting the cover (23). This can be useful in case of problems with the pump or sensors or with sterilization systems (UV lamp).

[0083] The cover (23) is preferably made entirely of porous draining concrete, while the inner or side wall (22) is only partially made of porous draining concrete, for example a portion (22A) close to the cover (23). The face 232 of the cover (23) facing the inner chamber (B) is for example slightly curved, so that the central part of the cover is located at a level higher than the level of the peripheral part of the cover.

[0084] The device is provided with an air hose system (40) associated with one of at least one passage (26), wherein the air hose system (40) has a first open end (40A) located in the intermediate chamber (TK), wherein a second end (40B) of the air hose system (40) is intended to be connected to an aeration system (41) and / or to an air supply device (42) (such as an air pump or a fan). The air hose system (40) can be used to ventilate the intermediate tank (TK), if the intermediate tank is filled with rainwater or city water, as well as to fill the intermediate tank (2) with air, to create an overpressure of air in the intermediate chamber and to allow air to circulate through the open channels of the porous concrete part (22A, 23A) to push any particles that may be present out of the open channels (and thus to clean the open channels).The air supply to the intermediate chamber can also serve to oxygenate the rainwater in the inner chamber (B), which is beneficial for the color of the rainwater, as well as its odor.

[0085] The supply pipe system (27) for supplying water from an external source is equipped with a filter element (27A) and / or a non-return valve (27B), the supply pipe system preferably also being equipped with a water collection system (27C) (e.g. a filling funnel) remote from the external water supply (50) and adapted to collect a waterfall or a discharge of water from the external water supply (50). Water from a tap 50A flows into the funnel 27C, without a connecting piece between the tap and the funnel. There is therefore a physical separation (air gap) between the tap 50A and the funnel 27C.

[0086] The device also comprises the following elements:

[0087] - an electrical system (60) (with 60A switch) for supplying electricity to the water pump (24), and / or

[0088] - a regulation system (70) receiving signals from the measurement system of the water level (25) and sending regulation signals to a control member (50A - controlled opening valve) of the external water supply (50). When the water level in the intermediate chamber (TK) is lower than the lower level of the lower sensor (25A), the control system (70) sends a signal to the control member (50A) to open the valve 50A and allow water to flow into the intermediate chamber (TK) via the inlet or supply pipe system (27), while after a step of opening the valve 50A, when the water level in the intermediate chamber (TK) exceeds the upper water level of the upper sensor (25B), the control system (70) sends a signal to the control member (50A) to close the valve (50A) so that no water from the external water supply (50) flows into the intermediate chamber (TK) via the water inlet pipe system.

[0089] The device comprises a water level measuring system (80) for measuring the water level in the inner chamber (B), as well as a control system (70) which receives signals from the water level measuring system (80) of the inner chamber (B) and from the water level measuring system (25) of the intermediate chamber (TK), wherein, depending on these signals, the control system (70) determines a parameter depending on the water permeability of the porous concrete part (22A, 23A), wherein if this particular parameter corresponds to a water permeability lower than a given minimum value, the control system (70) sends a signal to allow water and / or air to flow into the intermediate chamber (TK) via the supply pipe system (27) and / or the air pipe system (40),allowing water and / or air to flow from the intermediate chamber (TK) to the inner chamber (B) via the porous concrete part (22A, 23A). The control system (70) can thus determine when a cleaning step of the open channels of the porous concrete part (22A, 23A) must be carried out, by allowing water and / or air to circulate.

[0090] The device also comprises a sterilization system intended to be placed in the intermediate tank. The sterilization system (100) serves to at least partially sterilize the water in the intermediate tank. This is advantageous in particular during a step of cleaning the open channels of the porous concrete part. Preferably, the sterilization system comprises at least one UV lamp, preferably with UV-C radiation. With such a UV lamp, the risk of infection by bacteria is reduced.

[0091] The UV lamp is mounted in the intermediate tank, which places it in a protected environment. The UV lamp therefore only has to treat the water in the intermediate tank.

[0092] The power supply to the UV lamp may be provided by an electrical wire 101 passing through a passage (26). The UV lamp may also be mounted on the water pump. The UV lamp is preferably removably mounted in the intermediate tank (2) to facilitate its replacement.

[0093] The sterilization system must only treat a small volume of water present in the intermediate chamber (TK), and must not treat the entire volume of the inner chamber B of the tank or cistern (1). This ensures more suitable, faster, more efficient and less expensive treatment.

[0094] The concrete cover (23) is provided with an opening (23B) for forming a passage (26) for the supply pipe system (27), for the discharge pipe system (24A) and, preferably, for the air pipe system (40) and, preferably, for the UV lamp, this opening 23B thus forming a passage (26) for the supply pipe system (27) and discharge pipe system (24A). Said opening 23B or said passage (26) is provided with a sealant (26A, 90) to prevent water from the inner chamber (B) from flowing to the intermediate chamber (TK), through said opening or said passage (26), and water from the intermediate chamber (TK) from flowing to the inner chamber (B) through said opening or said passage (26).

[0095] The concrete cover is a porous concrete cover (23) having a substantially planar underside (231), wherein the inlet pipe system (27) has a free end (27D) remote from the substantially planar underside (231) for extending into the intermediate chamber (TK) and / or wherein the air pipe system (40) has a free end (40A) remote from the substantially planar underside (231) for extending into the intermediate chamber (TK). In this way, a free volume can be formed along the underside (231) of the cover (23), which free volume can be used to collect air or gas, released by rainwater. The air or gas thus released can then flow through the open channels of the porous cover, which is advantageous for cleaning purposes. If too much gas is released, this gas can be discharged through the air pipe system.

[0096] The concrete cover (23) is a porous concrete cover (23) having a water permeability of 0.1 liter / m2 / s to 5 liters / m2 / s, wherein said cover (23) has an opening (23B) forming a passage (26) at least for a part of the drainage pipe system (24A) and the water pump (24), wherein said opening (23B) is connected to a substantially vertical tube (90) forming an extension of the intermediate chamber (TK), wherein the substantially vertical tube (90) forms a channel adapted to lower a part of the discharge pipe system (24A) and the water pump (24) (preferably also the UV lamp, the UV-C lamp) into the intermediate chamber (TK), wherein said tube (90) has a top opening (90A) preferably above a maximum water level in the inner chamber (B) to prevent water from the inner chamber (B) from flowing through said upper opening (90A). The passage 26 is then formed by the tube 90 and the tube 90 can be considered as part of the intermediate chamber.

[0097] This tube (90) may be at least partially made of porous concrete. In this case, the partially porous concrete tube is part of the porous concrete part.

[0098] For a rainwater tank with an internal volume (B) of 1000 to 5000 liters, the volume of the intermediate chamber (TK) is for example 20 liters to 100 liters. The filling of the intermediate chamber with city water can be controlled (for example using an upper float 25B' (which is further from the cover 23) to fill only a part of the intermediate chamber, if it is almost empty. The volume of the intermediate chamber above the level of the float 25B' then forms a buffer volume of rainwater and / or air.

[0099] The tube 90 (attached to the intermediate tank (2)) can also be used to place or direct the intermediate tank on or towards the bottom 11 of the rainwater tank 1 via the manhole 91.

[0100] In the embodiment of Figures 3A, 3B and 4, the intermediate tank 2 comprises a non-porous concrete tank 20 and a removable porous concrete cover 23. The side walls of the tank 20 are provided with notches 20A, 20B, 20C, 20D, 20E to form passages 26 for: - the power supply wire 60 of the water pump 24, - the discharge pipe 24A of the water pump 24, - an inlet pipe 27 for filling the intermediate tank with water when necessary, - a ventilation pipe 40 which can also be used to supply air to the intermediate tank 2; - a 101 power supply wire for the UV lamp 100, and - a 25E wire for transmitting signals from the water level measuring system 25 to a control system 70.

[0101] In the embodiment of Figures 5 to 8, the rainwater tank 1 is part of the device according to the invention.

[0102] The rainwater tank 1 has two inner walls 12 along the bottom 11. These inner walls are parallel to each other and have a low height compared to the total height of the rainwater tank 1. These inner walls 12 extend between two side walls of the tank 1 to define the side walls of an inner tank in the chamber (B) of the tank 1.

[0103] The inner walls are made of non-porous concrete and serve as a support for a porous concrete slab (cover 23). The cover 23 is provided with five openings or holes 26 to form separate passages respectively for: - the power supply cable 60 of the water pump 24, and the discharge pipe 24A of the water pump 24, - an inlet pipe 27 for filling the intermediate tank with water when necessary, - a ventilation pipe 40 which can also be used to introduce air into the intermediate tank 2; - a 101 power supply wire for the UV lamp 100, and - a 25E cable for transmitting signals from the water level measuring system 25 to a control system 70.

[0104] These openings 26 are then sealed by means of a sealant 26A.

[0105] [Fig. 9] is a schematic representation of a control system (70).

[0106] The control system (70) receives signals from the water level measuring system 25 for the water level in the intermediate tank, and signals from the rainwater level measuring system 80 for the water level in the inner chamber B of the rainwater tank. The control system 70 also receives a signal indicating that the water in the intermediate tank should be evacuated by the water pump 24.

[0107] If the water level in the intermediate chamber TK is higher than the level 25A, the water valve 50A is kept in the closed state by the regulation system 70 (no city water flows into the intermediate chamber TK).

[0108] When the water level in the intermediate chamber TK is below the level 25A (and preferably when the control system receives a signal indicating that water is going to be pumped out of the intermediate chamber TK), the water valve 50A is opened by a signal from the control system 70 (city water flows into the intermediate chamber TK). When the water level in the intermediate chamber exceeds the water level 25B or 25B', the control system 70 sends a closing signal to the water valve to close this valve (city water no longer flows into the intermediate chamber).

[0109] The control system can determine whether the resistance to water flow through the porous concrete portion is greater than a certain resistance value, based on the time required to fill the intermediate tank with water from the inner chamber, and based on the water level in the inner chamber. If the calculated resistance exceeds the determined or maximum permitted resistance, the control system sends signals to clean the porous concrete portion. Cleaning can then be carried out by sending an operation signal to an air supply device (42) so that air is introduced into the intermediate tank and into the venting system to seal it. The intermediate chamber is thus filled with compressed air. This air will then circulate through the open channels of the concrete to clean them.

[0110] If the air cleaning is not sufficient, the control system sends a signal to fill the intermediate chamber with city water so that the water level in the inlet pipe is higher than the rainwater level in the inner chamber (which allows water to flow from the intermediate chamber to the inner chamber).

[0111] The control system also receives operating signals from the water pump and the UV lamp to determine if there is a malfunction.

[0112] The control system may also receive signals from one or more water quality sensors in the interior chamber of the rainwater tank and send operating signals to the air supply device (42) to bubble air through the water in the rainwater tank, i.e., to oxygenate the water in the rainwater tank.

[0113] With the device according to the invention, the filling of the storage buffer is done by means of an integrated float device or a system for measuring the water level in the intermediate chamber, which does not disturb the operation of the pump.

[0114] The percolation of water from the inner chamber to the intermediate chamber through the porous concrete portion can also be carried out with a suitable air supply, in order to obtain additional oxygenation for the water flowing through the porous concrete portion, and to oxygenate the water in the inner chamber. This is advantageous for improving the color and odor of the rainwater stored in the water tank.

Claims

1. Claims Device for reusing rainwater collected in an inner chamber (B) of a rainwater tank (1), wherein the device comprises at least: * an at least partially porous intermediate tank (2), adapted to be placed in the inner chamber (B) of the rainwater tank (1) or forming part of the rainwater tank (1) to be located in the inner chamber (B) thereof, wherein said intermediate tank (2) is defined at least between a bottom (11, 21), at least one side wall (12, 22) and a cover (23) to form an intermediate chamber (TK), wherein the side wall (12, 22) and / or the cover (23) comprises / contains at least one porous portion (22A, 23A), through which as soon as the water level (P) in the inner chamber (B) of the rainwater tank (1) is higher than a determined level (PI), rainwater flows from the inner chamber (B) to the intermediate chamber (TK) through the porous portion (22A, 23A) of the at least one side wall (22) and / or the cover (23), in which the intermediate tank (2) is equipped with a water pump (24),the water pump (24) being located in the intermediate chamber (TK);, * at least one passage (26) formed in the at least one side wall (22) and / or in the cover (23) and / or between the at least one side wall (22) and the cover (23); and * a discharge pipe system (24A) associated with the water pump (24), the discharge pipe system (24) being associated with one of the at least one passage (26), characterized in that * the bottom (11,21), the at least one side wall (12,22) and the cover (23) are made of concrete, * the device includes: - a water level measuring system (25) for determining at least a lower water level (25A) and an upper water level (25B) in the intermediate chamber (TK), - an inlet pipe system (27) associated with one of the at least one passage (26), in which the inlet pipe system (27) is adapted

2.

3. to collect water from an external water source (50) and to bring it into the intermediate chamber (TK); wherein the porous portion (22A, 23A) of the at least one side wall (22) and / or of the cover (23) is a portion of hardened porous draining concrete defining a total volume of porous concrete between a first face (231) facing the intermediate chamber (TK) and a second face (232) opposite the first face (231) and intended to be facing the inner chamber (B), wherein said hardened porous draining concrete is manufactured by curing a mixture comprising at least cement, aggregates with a grain size of 6 mm to 14 mm inclusive and water to obtain a volume of open pores forming open channels extending between said first face (231) and said second face (232) of said portion of porous draining concrete, said volume of open pores corresponding to 5% to 25%, preferably 10% to 25% of the total volume of porous concrete, said open channels extending between the first face (231) and said second face of the porous part (22A,23A) defining a water permeability of 0.1 litre / m2 / s to 5 litres / m2 / s, this water permeability being measured with a water level of 1 metre above the porous part (22A, 23A) and with a water level in the intermediate chamber (TK) maintained at a level lower than said lower water level (25A) of the intermediate chamber (TK)., Device according to claim 1, characterized in that along the second face (232), the porous draining concrete part (23A) is provided with a filter fabric or a filter membrane (30). Device according to claim 1 or 2, characterized in that the porous draining concrete part (22A, 23A) has a dry weight, and in that at least 5% of the total volume of the porous draining concrete part is formed by open channels between the first face (231) and the second face (232) with an average hydraulic diameter D of 100pm to 1000qm, where the average hydraulic diameter is determined by the following formula: D = 4 x WW / BET where: WW is the free volume of the open channels of the draining porous concrete part through which water can flow between the second face (232) and the first face (231), said free volume being expressed per unit of dry weight of the draining porous concrete part, this free volume expressed per unit of dry weight being measured after allowing water to percolate into the draining porous concrete portion through the second face so that the entire free volume of the open channels is filled with water, and after determining the volume of water that can be extracted through the first face, said volume of water thus determined then being divided by the dry weight of the draining porous concrete portion, this free volume per unit weight being expressed in cm3 / g; and BET is the BET (Brunauer, Emmett and Teller) specific surface area expressed in cm2 / g of the dry draining porous concrete portion.

4. Device according to claims 2 and 3, characterized in that the filter fabric or the filter membrane (30) has open pores with a diameter greater than the average hydraulic diameter D of the open channels of the porous draining concrete part (23A), and in that preferably, said filter fabric or said filter membrane (30) has at least two filter layers (30A, 30B), in which a first filter layer (30A) having open pores with a first average diameter DI is directed towards the second face (232) of the porous draining concrete part (23A) with respect to a second filter layer (30B) having open pores with a second average diameter D2, in which the second average diameter D2 is larger than the first average diameter D1.

5. Device according to any one of the preceding claims, characterized in that the concrete cover (23) is at least partially porous, the concrete cover (23) being removable relative to the at least one concrete side wall (22).

6. Device according to any one of the preceding claims, characterized in that the device is provided with an air hose system (40) associated with one of the at least one passage (26), wherein the air hose system (40) has a first open end (40A) located in the intermediate chamber (TK), wherein a second end (40B) of the air hose system (40) is intended to be connected to a ventilation system (41) and / or an air supply device (42), while advantageously the inlet hose system (27) is provided with a filter element (27A) and / or a non-return valve (27B), wherein the inlet hose system is preferably also provided with a water collection system (27C) arranged separately from the external water supply (50) and adapted to collect a waterfall or water discharge from the external water supply (50).

7. Device according to any one of the preceding claims, characterized in that the device also comprises one or more of the following: - an electrical system (60) for supplying electricity to the water pump (24), and / or - a regulation system (70) receiving signals from the water level measuring system (25) and sending regulation signals to a control system (50A) of the external water supply (50), wherein if the water level in the intermediate chamber (TK) is lower than said lower level of the intermediate chamber (TK), the regulation system (70) sends a signal to the control system (50A) to allow water to flow into the intermediate chamber (TK) through the inlet pipe system (27), while if, at least after water has been supplied into the intermediate chamber (TK) through the inlet pipe system (27),the water level in the intermediate chamber (TK) exceeds the upper water level (25B) of the intermediate chamber (TK), the control system (70) issues a signal to the control system (50A) so that no water from the external water supply flows into the intermediate chamber (TK) through the inlet pipe system (27), and / or - a water level measuring system (80) for measuring the water level in the inner chamber (B), as well as a control system (70) which receives signals from the water level measuring system (80) of the inner chamber (B) and from the water level measuring system (25) of the intermediate chamber (TK), wherein depending on these signals, the control system (70) determines a parameter of the water permeability of the permeable porous concrete part (23A), wherein, if this determined parameter of the permeability corresponds to a water permeability lower than a minimum value,the control system (70) issues a signal to allow water and / or air to flow into the intermediate chamber (TK) through the inlet pipe system (27) and / or the air pipe system (40), thereby allowing water and / or air to pass from the intermediate chamber (TK) to the,

8.

9. inner chamber (B) through the draining porous concrete part (22A, 23A), and / or - a sterilization system, in particular a UV lamp, intended to be placed in the intermediate chamber (TK), and / or - a concrete rainwater tank (1) provided with at least one concrete inner wall (12) along its bottom (11), wherein said at least one concrete inner wall (12) of the tank is adapted to form a support for an at least partially porous concrete cover (23), wherein the intermediate chamber (TK) is defined by the at least partially porous concrete cover (23) and the at least one concrete inner wall (12). Device according to any one of the preceding claims, characterized in that the concrete cover (23) is provided with one or more openings (23B) for forming at least one passage (26) for the inlet pipe system (27), for the discharge pipe system (24A) and, preferably, for the air pipe system (40), wherein this or these openings (26) are provided with a sealant (26A) to prevent water from the inner chamber (B) from flowing through this or these openings (26) to the intermediate chamber (TK), and water from the intermediate chamber (TK) from flowing through this or these openings (26) to the inner chamber (B), and in that, preferably, the concrete cover is a porous draining concrete cover (23) having a substantially flat lower surface (231),wherein the inlet pipe system (27) has a free end (27D) remote from the substantially flat lower surface (231) for extending into the intermediate chamber (TK) and / or wherein the air pipe system (40) has a free end (40A) remote from the substantially flat lower surface (231) for extending into the intermediate chamber (TK)., Device according to any one of the preceding claims, characterized in that the concrete cover (23) has an opening (23B) forming a passage (26) at least for a part of the discharge pipe system (24A) and the water pump (24), wherein said opening (23B) is connected to a substantially vertical tube (90) forming an extension of the intermediate chamber (TK) into which the substantially vertical tube (90) forms a channel suitable for introducing a part of the discharge pipe system (24A) and the water pump (24) in the intermediate chamber (TK), wherein said substantially vertical tube (90) has an upper opening (90A) adapted to be preferably located above a maximum water level in the inner chamber (B) to prevent water from the inner chamber (B) from flowing through said upper opening (90A) into said substantially vertical tube (90), and wherein advantageously, said substantially vertical tube (90) is at least partially porous, in particular at least partially made of porous permeable concrete.

10. Device according to any one of the preceding claims, characterized in that the intermediate reservoir (2) has a volume of between 1 and 200 liters, preferably between 30 and 100 liters.

11. Use of a device according to any one of the preceding claims, for the reuse of rainwater collected in an inner chamber (B) of a rainwater tank (1), in which the water can flow from the inner chamber (B) of the tank to the intermediate chamber (TK) of the device, through the at least porous part of the side wall (12, 22) and / or the cover (23), in which the at least porous part of the side wall (12, 22) and / or the cover forms a filter element for the water flowing from the inner chamber (B) to the intermediate chamber (TK).

12. Use according to claim 12, for oxygenating the rainwater present in the inner chamber (B) of the rainwater tank (1).

Images