Abstract:
A device for reusing greywater includes: a water feed for supplying greywater; a collecting reservoir for collecting the supplied greywater; a storage tank for storing water; a siphoning device for siphoning water from the collecting reservoir to the storage tank; a water discharge for discharging stored water to a water user; a sewer outlet; and a control system. 
     A method of siphoning water includes: supplying water to a collecting reservoir; detecting a predetermined water level in the collecting reservoir; operating a filling valve subject to the detected water level; and siphoning water via a siphon connection from the collecting reservoir to the storage tank.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a greywater device and method for applying thereof. 
       BACKGROUND INFORMATION 
       [0002]    Diverse energy standards have been drawn up by government authorities in order to spare the environment. One of these is the Energy Performance Standard (EPS) which expresses the energy efficiency of a new dwelling in the so-called Energy Performance Coefficient (EPC). The EPC represents the energy consumption of a building relative to a similar reference building described in the standard (for dwellings and residential buildings in the Netherlands this is currently NEN 5128/2001). This EPC is calculated on the basis of the building properties (insulation value of walls, floors, glazing and so forth) and installations (for instance solar collectors, ventilation systems and heating). The lower the number, the greater the energy efficiency of the building. The Energy Performance Coefficient (EPC) can thus be deemed as a measure for the (average) energy quality of a building, including the technical installations. The level of the EPC is laid down in the Building Act in the form of a minimum EPC requirement, which is set at 0.8 as of Jan. 1, 2006. All newly built houses must comply with this maximum allowed EPC. 
         [0003]    Energy consumption is determined on the basis of, among other factors, the energy consumption for heating, hot tap water, pumps, cooling, fans and lighting. If a newly built house does not achieve an EPC of 0.8, this means that additional measures such as solar panels and/or triple glazing must be applied, and this can markedly increase the cost of building a house. 
         [0004]    One method of making efficient use of energy and environment is to reuse lightly contaminated water. Instead of mains water, which is treated with considerable effort and at a great cost in wastewater purification plants, less clean non-potable water can be used for some applications, such as, for instance, flushing the toilet. It is thus possible to envisage the use of collected rainwater and the reuse of lightly contaminated bath and shower water, also referred to as greywater. This saving of water furthermore results in a proportional reduction in the stress on the sewage system. 
         [0005]    The use of the relatively warm greywater also has another favorable effect on the Energy Performance Coefficient (EPC): there is a reduction in the “cold source” which normally occurs when cold mains water is fed into and stored in a cistern. The system itself moreover also has a favorable effect on the EPC in the form of heat generation. 
         [0006]    Netherlands Patent No. 1011371 describes a reservoir for greywater with a feed for greywater and a discharge connected to a greywater user such as a toilet or the like. The reservoir is provided with an outlet which connects to the sewer and which is provided with a valve to be opened at regular intervals by a time clock. Regular disposal of greywater prevents odor nuisance being caused. 
       SUMMARY 
       [0007]    Example embodiments of the present invention may improve, in particular make more compact and/or more efficient, a greywater device. 
         [0008]    According to example embodiments of the present invention, a greywater device includes: a water feed for supplying greywater; a collecting reservoir for collecting the supplied greywater; a storage tank for storing water; a siphoning device for mechanically siphoning water from the collecting reservoir to the storage tank; a water discharge for discharging stored water to a water user; a sewer outlet; and a control system. 
         [0009]    An advantage of the above example embodiment is that, due to the application of a mechanical siphoning device operating substantially on the basis of the force of gravity, no additional energy is required. On the one hand this makes the device cheaper to purchase and maintain, and on the other cheaper and more energy-efficient in use; no electrical energy is after all used. This is favorable for the environment. It also limits the necessity for other expensive energy-saving measures, such as, for instance, additional insulating glass and/or solar panels. 
         [0010]    Arranged on the top side of the collecting reservoir is an overflow which connects to a bypass conduit for diverting water to the sewer outlet. Water which is discharged via the overflow and the bypass conduit is collected by a siphoning device, which includes: a siphon connection for siphoning water from the collecting reservoir to the storage tank; a filling valve; and a receiving device for receiving supplied greywater, wherein the receiving device is connected to the filling valve. 
         [0011]    The connection between the receiving device and the valve can take place mechanically or electrically. 
         [0012]    Because greywater including bath and shower water is lightly contaminated, a separation is recommended. Example embodiments of the present invention may apply a separating principle which is based on a difference in specific weight between the water and the contaminants present in the water. The siphon connection for siphoning water from the collecting reservoir to the storage tank is therefore arranged substantially in the central part of the substantially vertically arranged collecting reservoir. 
         [0013]    It may occur that the water requirement of the water user connected to the greywater device cannot be provided by the stored greywater. So as to also provide for delivery of the water requirement in these situations, the storage tank may be further provided with a mains water feed for filling the storage tank with mains water. 
         [0014]    In order to prevent odor nuisance and, for instance, legionella and to be able to discharge all contamination accumulated in the device periodically and/or subject to user, the greywater device according to an example embodiment of the present invention may be provided with a draining device for draining greywater under the control of the control unit. 
         [0015]    At least one cleaning unit may be arranged to provide cleaning of the greywater device. In an example embodiment, water supplied by the mains water feed is used by this cleaning unit. 
         [0016]    An adding unit may be arranged for adding an additive to the water, such as a disinfectant, cleaning agent or a fragrance. 
         [0017]    The greywater device may be accommodated in a support frame. An advantage of this arrangement is that a module is provided which can be placed in a relatively short period of time by an installer. 
         [0018]    A cistern can also be integrated into the support frame. It is also energetically favorable to arrange a heat exchanger in, for instance, the cistern and/or the collecting reservoir or storage tank. 
         [0019]    In the following description, exemplary embodiments are described in further detail with reference to the appended Figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0020]      FIG. 1  shows a schematic view of a greywater device according to an example embodiment of the present invention in a rest position. 
           [0021]      FIG. 2  is a schematic view of the greywater device shown in  FIG. 1  when the greywater is being supplied. 
           [0022]      FIG. 3  is a schematic view of the greywater device shown in  FIG. 1  when the collecting reservoir is filled with greywater. 
           [0023]      FIG. 4  is a schematic view of the greywater device shown in  FIG. 1  when the system is being drained. 
           [0024]      FIG. 5  is a schematic view of a greywater device according to an example embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0025]    A greywater device according to an example embodiment is shown schematically in  FIGS. 1 to 4  and includes: a collecting reservoir  2 , a storage tank  4 , an overflow  6  with a skimmer  8 , a bypass conduit  10 , a siphoning tube  12  connecting the collecting reservoir and the storage tank, a feed conduit for supplying greywater  14 , a discharge conduit for discharging water to a water user, such as a toilet  16 , an activating device in the form of a receiving vessel  18  which rotates about a shaft  20  and an arm with weight  22 , a plunger rod  24  which operates a filling valve  26 , a drainage valve  28 , aerators  30  and  32 , a sewer outlet  34  and further a control unit (ECU)  43  which is connected with sensors and actuators to the parts of the system to make it possible to take user-dependent action. 
         [0026]      FIG. 1  shows the greywater device in a rest position, wherein the collecting reservoir is partially filled with water. Lightly contaminated water will be produced when use is made of shower and bath. Instead of allowing this water to disappear directly into the sewer, it is collected via a feed  14  in collecting reservoir  2 , which will thereby become filled with greywater. Drainage valve  28  and filling valve  26  are both closed, whereby the water level in collecting reservoir  2  will rise when greywater is supplied via feed  14 . 
         [0027]    Greywater collected directly from bath and shower contains contaminants such as soap residues, flakes of skin and hair, thereby making a form of separation or filtering desirable. A separating principle is applied that is based on a difference in density or specific weight between the water and the contaminants present in the water. 
         [0028]    On the top side of collecting reservoir  2  is arranged an overflow  6  where greywater flows away via a bypass conduit  10  in the direction of activating device, which in the shown example embodiment includes, among other parts, a receiving vessel  18  and a plunger rod  24 . Contaminants with a density lower than that of water (ρ contaminant &lt;ρ water ) , such as, for instance, soap residues, will float and therefore be drained together with the greywater via overflow  6  and bypass conduit  10  in the direction of the activating device. In order to prevent contaminants continuing to float on the top, a skimmer  8  is arranged for skimming off these contaminants in the direction of bypass conduit  10 . 
         [0029]    The relatively heavy contaminants, such as, for instance, sand residues, with a density which is greater than that of water (ρ contaminant &gt;ρ water ), will be collected due to settling at the bottom of collecting reservoir  2 . 
         [0030]    Because light contaminants will float and heavy contaminants will sink, the cleanest water will be situated substantially in the central part, i.e., between the top and bottom of collecting reservoir  2 . 
         [0031]    Water which flows away via overflow  6  and bypass conduit  10  at the top of collecting reservoir  2  will be received in a receiving vessel  18  ( FIG. 2 ). This receiving vessel  18  is arranged asymmetrically on a shaft  20 . By compensating this asymmetry with an adapted weight distribution, such as, for instance, with an arm and a weight  22 , receiving vessel  18  is balanced such that in empty state the receiving vessel  18  is oriented substantially horizontally. When receiving vessel  18  is filled with water supplied via bypass conduit  10 , the balanced position will be disturbed as a consequence of the asymmetrical form and, as a result of this imbalance, receiving vessel  18  will begin to tilt ( FIG. 3 ). Due to this tilting the receiving vessel  18  will, for instance, by its arm, displace a transfer member, for instance, in the form of a plunger rod  24 . Filling valve  26  is opened by the displacement of plunger rod  24 . It will be apparent to the skilled person that it is also possible here, for instance, to arrange a sensor which detects a movement of receiving vessel  18  and then electrically operates filling valve  26 . It is noted for the sake of completeness that such a sensor can also be arranged at other suitable locations, such as, for instance, in bypass conduit  10 , where this sensor can detect water overflowing via overflow  6  into the bypass conduit. Although it will be apparent to the skilled person, various aspects are further described in  FIG. 5 , where a sensor  7  is arranged. This sensor  7  is connected via wiring  9  to control unit  43  which, subject to the signal received from sensor  7 , energizes via wiring  11  a coil  25  arranged round plunger rod  24 . 
         [0032]    Prior to opening of the filling valve there prevails in storage tank  4  a balance between the air pressure present above the water level and the water pressure. Because collecting reservoir  2  has meanwhile been filled and the water level in collecting reservoir  2  has risen above the water level in storage tank  4 , the water pressure in storage tank  4  has increased. As a result, the air present in storage tank  4  above the water level will be compressed to some extent. Through opening of filling valve  26  the air pressure in storage tank  4  will decrease to the ambient air pressure. The equilibrium of forces between the air and the water in storage tank  4  is hereby disturbed, and water will be siphoned from collecting reservoir  2  to storage tank  4  via siphoning tube  12 . The water level in collecting reservoir  2  will hereby fall and the water level in storage tank  4  will rise. 
         [0033]    When receiving vessel  18  tilts and filling valve  26  opens by plunger rod  24 , receiving vessel  18  will drain. The imbalance will hereby disappear and receiving vessel  18  will move back again to its balanced position, wherein receiving vessel  18  is oriented substantially horizontally. 
         [0034]    As long as greywater is supplied via feed  14 , the water level in collecting reservoir  2  will rise until water once again flows via overflow  6  of collecting reservoir  2  into receiving vessel  18  via bypass conduit  10 . Receiving vessel  18  will hereby tilt once again. As a result filling valve  26  will be opened and—through repetition of the above—the storage tank will fill in pulsating manner until the water level in storage tank  4  and collecting reservoir  2  reach the same level. 
         [0035]    The system will be drained periodically in order to discharge contaminants and to prevent the occurrence of odor nuisance which may occur when the greywater has been stored for too long in the system. The settled contaminants situated at the bottom of collecting reservoir  2  are discharged periodically by opening drainage valve  28  on the underside of collecting reservoir  2  and opening aerators  30  and  32  on the top side ( FIG. 4 ). The stored water will hereby disappear together with all contaminants into the sewer via sewer outlet  34 . The control system (EcoPlay Control Unit (ECU)) will control this drainage subject to parameters such as the time elapsed since the last filling. In the case of power failure, the greywater present in the system can, for instance, so as to prevent legionella, be drained as final action, whereafter the system is filled with normal mains water. A mains water feed  38  is arranged for this purpose. 
         [0036]    Mains water feed  38  is further provided so as to be able to continue to meet the requirement of the water user, such as the toilet, in the case too little greywater is being supplied. 
         [0037]    It is possible to spray the walls of collecting reservoir  2  using the mains water supplied via mains water feed  38 . Limescale that may be present can be removed by opening drainage valve  28 , preferably during spraying or thereafter. 
         [0038]    The greywater device may be accommodated in a support frame  40  which can be placed simply and quickly by an installer. The whole module can, for instance, be mounted on a wall with a number of expansion bolts. The feed and discharge conduits must then be installed, for instance, with clamp fittings. An example of the dimensions such a module will have is a height of about 2.6 m and a width of about 0.9 m. The module may be arranged such that variations in these dimensions can be readily compensated. A cistern  42  may be integrated into support frame  40 . 
         [0039]    Example embodiments of the present invention further provide a method for siphoning water in a device for greywater. 
         [0040]    Although they are preferred embodiments of the invention, the above described example embodiments are intended only to illustrate the present invention and not in any way to be limiting. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.