Patent Publication Number: US-2010125938-A1

Title: Installation for recycling sanitary water

Description:
FIELD OF THE INVENTION 
     The present invention relates to an installation for recovering or recycling sanitary waste water from the baths, showers, sinks, etc. of a home and its reuse for flushing toilet bowls. 
     STATE OF THE ART 
     In homes, dwellings, hotels and more generally in any estate complex, the sanitary installations use a great volume of running water, generally drinkable, directly taken from the main supply network. In an urban environment, the volume of running water used and thus flushed down the drains amounts to millions of litres, of which almost 80% is used by sanitary installations and half of which in turn is used solely for flushing toilets. Thus, for example, each European uses 120 litres of drinking water every day. Of these 120 litres, 40 litres are used to flush toilet bowls, i.e. the equivalent of 6 flushes max. This use of running water comes at a consumption cost that is higher and higher because of the purification costs imposed by ever stricter environmental constraints. 
     Irrespective of its high cost, the continuity of water supply is sometimes critical in certain inhabited zones or certain residential zones with seasonal occupation. Moreover, many regions of the world have no or very limited natural water reserves. And even in regions that are rich in groundwater, problems of supply regularly occur during long periods of drought. Climate specialists are already predicting that this situation threatens to become more and more frequent and critical in the coming decades. 
     It is therefore essential to be able to efficiently distribute water, and above all to consume it reasonably, if not sparingly. And on the other hand, it is important in this regard for homes, dwellings, hotel complexes and other such places to be organised or reorganised according to an efficient lay-out that allows saving water. In general, sanitary waste water is flushed directly into a common collection pipe that drains into a sewage network. Not only does this disposal of sanitary water represent an important consumption of water coming from the supply network, but the water thus disposed of also contains numerous residual products that contribute to environmental pollution. 
     Apart from the quantity of running water used for bodily hygiene, a large quantity of running water is thus also used in the flushing mechanisms of toilets. Major water savings could be achieved by using the waste water recovered from the other sanitary equipment commonly found in homes or residential/hotel complexes for flushing toilet bowls and by using running water for toilet bowls only when there is no more waste water available. 
     It is already known to recover waste water to flush a toilet bowl. The waste water is collected in storage tanks connected to the tanks of the flushing systems usually fitted in toilets. A system of this type entails often expensive plumbing work and the installation of often annoying or visible pipework. 
     Rather theoretical solutions have been proposed with regard to the distribution of water for flushing toilet bowls by incorporating the recycling of waste water into a sanitary unit for toilets, of a “tower-cupboard” type, and by taking into account problems of reliability and hygiene (see for example EP-A-1 516 968, GB-A-611 893, GB-A-2 143 559, DE-A-16 09 218, etc.). 
     More particularly, document WO-A-2004/057119 proposes a system for recycling used water coming for example from a shower unit, in particular in the form of a water-saving toilet-flushing system, comprising at least one tank equipped with a flushing plug having a float, a running-water inlet and a used-water outlet connected to the tank. The float, pivotably fitted by a rod at the side of the tank, may move vertically and activate by means of a shaft the opening of a valve located on the running-water inlet when the level of used water in the tank is not sufficient. More precisely, the system is connected to a washing machine with a main pump whose power has been boosted compared with the original pump, this pump allowing to convey to the tank the used water coming from the washing machine. An additional pump allows conveying the used water from the shower unit possibly to another tank. Each used-water pipe has a filter positioned between the relevant pump and the inlet into the tank. 
     The recycling of waste water from washing machines is not of great interest since it is often dirt-loaded and foul-smelling. Moreover, it generally contains much more detergent and foam. This leads to the formation of a large amount of foam in the tank as well as heavy deposits in the filter and in the tank. 
     Using the original pump of the washing machine to transfer the waste water into the tank is not possible since it can only raise the water by about 1.2 m. It is therefore necessary to modify this pump, hence to work on a machine that has not been designed for these modifications, with the consequence that the guarantee provided by the manufacturer is lost. 
     Placing the second pump in the washing machine is generally not possible because that possibility is not foreseen by the manufacturer, these modifications belonging more to makeshift DIY rather than to a professional system. Possible jamming or breakdown of the motor of the second pump would also make it impossible to drain the bathtub or the shower unit. Moreover, the mandatory presence of a washing machine near the bathtub is not a very common situation (i.e. laundry and bathroom side by side). 
     Moreover, using a filter over the buffer tank is not recommended. Positioned after the pump, it restricts the flow when it becomes clogged and strains the pump  21  or  31  until the latter is jammed. In addition, the filter is positioned over the tank in a location hidden behind a decorative screen, making access difficult or even impossible. The waste water is treated at the level of the filter just above the inlet of treated water into the tank. At the outlet of the filter, the flow into the tank is free but has the disadvantage of generating a great deal of noise and foam. 
     The running-water supply is ensured by a valve activated by a float as in a standard commercial flushing system and the overflow of the buffer tank visibly drains in the toilet bowl by means of a pipe. 
     AIMS OF THE INVENTION 
     The present invention aims to provide a solution that overcomes the drawbacks of the state of the art. 
     The invention aims to provide an rational and effective solution to the general problem of the supply and the use of water for toilets in a home or any building. 
     In particular, the invention aims to propose a sanitary installation that optimises the water supply for flushing a toilet bowl with the rational incorporation of a water-saving system. 
     Another aim of the invention is to propose a solution that automatically maintains perfect hygiene of the sanitary installations and efficiently respects the environment. 
     Another aim of the invention is to provide a flushing system that is compatible with the above-mentioned installation and in particular with a high water column, this flushing system has to be at the same time reliable, robust and silent. 
     Yet another aim of the invention is to propose a sanitary installation for toilets whose operation and maintenance may be programmed depending on the user&#39;s requirements. 
     Yet another aim of the invention is to propose a sanitary unit for toilets that incorporates a water-saving system and that can easily be installed in any room of a home or premises of current dimensions without requiring major and expensive plumbing work. 
     MAIN CHARACTERISTIC ELEMENTS OF THE INVENTION 
     The present invention relates to an installation for recycling waste water from a sanitary equipment and for reusing it to flush at least one toilet bowl, equipped with a system for saving flushing water fitted above the toilet, said water-saving system comprising a tank that may comprise water storage, a water-flushing mechanism positioned in the tank to provide the water for flushing the toilet bowl, a first pipe for supplying said waste water to the tank, a second pipe for supplying running water to the tank, a filter and a pump positioned in the first pipe, a water-level sensor to control the level of waste-water storage retained in the tank, a controlled stop valve to control the intake of running water, said stop valve being normally closed and temporarily opening when the volume of water remaining in the tank and detected by the water-level sensor is lower than a predetermined volume, wherein the mechanism for flushing the water comprises a vertical-action drain valve positioned inside a flow-control tube that extends over the entire height of the tank and only connected to the rest of the tank by one or more apertures drilled in the side of said tube. 
     Preferred embodiments of the present invention are described in secondary claims  2  to  19 . 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  schematically shows a complete installation for recovering sanitary water and flushing a toilet bowl as in the present invention. 
         FIGS. 1B and 1C  show top views of the side and of the front, respectively, of the toilet bowl and its tank. 
         FIG. 2  shows a detailed view from the side and the front of the above-mentioned installation at the level of the tank. 
         FIGS. 3 and 4  schematically show the waste-water recovering system with a filter and a pump in the cases of a bathtub and of a shower, respectively. 
         FIGS. 5 and 6  show embodiments of the control terminal of the installation as in the present invention. 
         FIG. 7  shows a detailed view of a preferred embodiment of the flushing mechanism for the toilet as in the present invention. 
         FIG. 8  schematically shows an example of device connecting the pipe for supplying running water to the tank with a pipe for collecting rainwater. 
     
    
    
     PRESENTATION OF THE INVENTION 
     The present invention relates to a new system for recovering the water used by one or more people during their daily washing, whether from a bathtub or from a shower. This water is first mechanically and chemically filtered, coloured, scented and then stored in a 180-litre tank, for example—which is a greater volume than that of the average bathtub—located in the same position as the traditional tank of the state of the art. This tank is simply taller than a traditional tank since its capacity is significantly greater, but this has no adverse effect whatsoever since the extra space required is rarely used. 
     The potential uses of the invention are the following:
         renovation of toilets in existing homes: the system as in the invention replaces the existing flushing system with no additional floor space requirement or major installation works. It may be incorporated into a new range of toilet furniture, also allowing practical storage for toilet accessories;   new houses or dwellings, new apartments: the tank may be hidden in a service shaft;   hotels, where the average consumption of drinking water of 255 litres of water per day and per room is significantly higher than the average private consumption;   schools and restaurants.       

     The installation may also be connected to washbasins and to rainwater drain pipes. 
     The system is a hybrid system. In the event of shortage of recycled water, the drinking water network may be used as supplement. This system is therefore designed so that it is never unusable, which leads to an estimated drinking-water saving of 14,600,000 m 3  per annum and per million inhabitants (i.e. a third of current consumption). The saving achieved is both direct (lower bill as a result of lower water consumption) and indirect (reduction of public spending on waste-water treatment). Taxation on consumed water is reduced and the distribution of public subsidies supports the investment. 
     The installation as in the invention also comprises a device for extracting odours at the source by means of the toilet bowl that returns them to the existing or planned ventilation duct. This technique increases comfort and improves the ventilation of the room. The system operates with an interior sensor. 
     Moreover, the system as in the invention will advantageously comprise a control system either for private homes or for hotels, possibly with a digital display and a supervision of the system by a central control facility. 
     A pump and filter system is positioned under the bathtub (or the shower) next to the trap so as to prevent drain noise and the formation of foam. It is therefore easily accessible through the access hatch. The bathtub or the shower may be several metres away from the tank. Lastly, the wall-mounted toilet bowl is standard. 
     DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
     The invention is based on the recovery of the used water or “grey” water mainly coming from the bath, shower, washbasins, etc. in order to flush the home&#39;s toilet bowl(s). 
     As shown in  FIG. 1A to 1C , the system as in the invention is advantageously designed to be used with a wall-mounted toilet bowl  1 . 
     Starting at the outlet of the bathtub  22  or shower  23 , the drain pipe  21  coming from their traps enters a filter ( FIGS. 3 and 4 ). This filter comprises a plastic housing (for example PVC, ABS, PE, etc.) of relatively small size (for example 150×250×165 mm), a filter cage  20  for coarse filtering (0.5-1 mm) and disposal of particles such as hair, a level probe  18  with a float and “reed” contact allowing to give the alert when the filter is clogged and needs cleaning, as well as an outlet towards the discharge (not shown) for overflow if a pump breaks down. 
     The product used for treating the grey water is of a solid type and is placed in the filter cage  20  where it progressively dissolves when the bathtub or shower is drained. The functions of the treating product are for example coloration, disinfection, descaling and the addition of deodorising products. 
     The outlet of the filter housing directly enters the intake of a pump  19 . The pump  19  is of a “lift pump” type of a common brand (Grundfos®, SFA®, etc.). The pump  19  is equipped with a switch for the automatic start-up as soon as the level of grey water exceeds 55 mm, a flapper and a vent. Of course, the principle of the invention remains the same if the two housings with the filter and the pump are made in a single part. 
     The pipe, which will be hidden in the screed, is connected at the outlet of the pump  19  and its other end will be connected to the intake pipe  7  in the storage tank  3 . 
     The filter/pump assembly is preferably positioned under the bathtub  22  just behind the inspection hatch so as to provide easy access for maintenance. In the case of the shower  23 , the assembly is positioned next to it in an adapted housing with an inspection hatch or alternatively in a housing located under the shower unit in the screed. In some cases, the assembly may thus be hidden in the screed. 
     As shown in  FIG. 2 , the intake pipe  7  enters the tank and extends in an elbow shape whose end  15  arrives at the bottom of the tank so as to prevent drain noise. 
     The toilet bowl  1  is attached to rods  4  of the support  1 A; this support being fixed to the floor and wall behind the tank, it will thus support the bowl  1 , the tank  3  and the discharge pipe  2 . 
     The tank  3  with an effective capacity of 170-180 litres is made of a plastic material (polyester or polyethylene, for example). If this tank feeds several toilet bowls, its capacity may of course be increased. It is drilled with the holes required for placing the pipes, probe(s) and valves. 
     As indicated above, the tank  3  is supplied with grey water by pipe  7 . When the water level in the tank  3  reaches the maximum allowed height, the water is drained through the overflow pipe  8  into the discharge pipe  2  through the trap  10 . 
     One essential element of the present invention is an original flushing mechanism. This is constructed on the basis of a standard mechanism but with modifications to reinforce the flushing mechanism because the latter must resist to a much greater water pressure head than in the case of a normal flushing mechanism and to water-hammers when the valve is closed, which risks damaging it much more than with normal use. For another thing, this major fall of water is noisy. 
     As shown in detail in  FIG. 7 , the valve  25 A comprises a more or less cylindrical main guiding body  25  ending in a thread and in a fixing and locking nut  33 , a valve body  26 , a joint made of EPDM  30  and a set of PVC and rubber washers  28 ,  29  for fitting the assembly. 
     In order to control the water flow when it streams into the toilet bowl, a PVC tube  27  drilled with at least two holes  35  (with a diameter of 8 mm, for example) and of a height equal to the internal height of the tank  3 , is fixed in the tank  3  by the body of the valve  25 , 33  and sealed by means of sealing joints  31 , 32 . Thus, when the tank  3  is full or when the pressure head in it is very great, activating the flush causes the water in the tube  27  to drain. This drainage is much faster than the refilling of the tube through the holes  35  due to the compensation for the drop in pressure in the tube because of the small diameter of these holes. This system therefore has the advantage of providing the correct amount of water required for the proper operation of the flush between the moment of opening and the moment of closing the valve. Moreover, this system has the advantage of very greatly reducing the noise of the flush. 
     The drain valve is activated by a geared motor  14  ( FIG. 2 ) equipped with a cam and positioning end stops. This raises the valve by means of the rod  24  and of the chain  17 . A manual control lever, not shown, is positioned above the tank for manually activating the valve during any power failure. 
     When the level of grey water in the tank drops and goes below a predefined minimum value, a probe sets off an electrically controlled valve  13  at the level of the running-water pipe  13 A. As soon as the grey water is delivered to the tank, the level rises again and the running-water supply is cut off. 
     The system is supplemented by forced ventilation  12  of the toilet bowl. 
     The whole system is controlled by an electronic terminal  40  with a microcontroller. 
     An example of a terminal  40  shown in  FIG. 6  can be built in and comprises two buttons: one for a flush of about 8 litres, the other for an economical flush of about 3 litres. It comprises three lights indicating the status of the system and signals any system fault. The “Ready” light indicates that the system is energised. If it flashes, it indicates a malfunction of the electronic part. The “Pump” light comes on when the pump is faulty, the microcontroller checking the current consumed by the pump when operating. The “Filter” light comes on when the filter needs cleaning. 
     In a more developed version ( FIG. 5 ), the terminal  40  has an LCD display  41 , for example with 2×16 characters, or graphics displaying the status of the system but also intended for displaying messages in the context of use in hotels or institutions. 
     The system proposed within the context of the present invention has numerous advantages over the systems known from the state of the art, and in particular over that described in document WO-A-2004/057119. 
     According to the invention, a filter and a standard lift pump that a plumber can easily fit under a bathtub or next to a shower are used. The presence of an overflow at the level of the filter guarantees that the system will work in all circumstances. These two elements are accessed through the inspection hatch positioned beside the trap. A level probe located in the filter housing warns when the filter needs cleaning. 
     According to the invention, the filter is positioned upstream from the pump, thus avoiding overloading and possibly jamming it in the event of the filter being clogged. The grey water is thus treated at the level of the filter, in which the water is treated as soon as it leaves the bathtub or shower until it reaches the buffer tank, as well as in the pipes. 
     The tank overflow streams into the toilet&#39;s drain pipe and not into the bowl. 
     The drain valve is defined and activated by a geared motor and not by a traditional, rudimentary float system. 
     The device as in the invention may comprise a flow regulator made of a special tube acting as a tank. 
     The drinking-water supply is controlled by a probe and an electrically controlled valve. As an advantage, the pipe supplying the running water to the tank may be connected, upstream from the controlled stop valve, to a device for collecting rainwater, as shown by way of an example in  FIG. 8 , the stop valve to the supply pipe of running water being open and closed, respectively. 
     The system as in the invention is designed for a wall-mounted toilet bowl, the support being designed to take both the tank and the toilet bowl. 
     The system as in the invention comprises the forced ventilation of the toilet bowl by means of an electrically-operated fan. 
     Lastly, the whole system is controlled by an electronic terminal. This controls the flush, the filling with drinking water, the pump and the filter.