Abstract:
Device for recirculating shower water: a mixing device is connected directly to the hot and cold water inlets, the cold water inlet is connected to a recirculation system; a pump is actuated while the cold water inlet is cut off. In such a device, the hot water flow rate is kept by the mixing device just high enough to compensate for the thermal losses of the water circulating through the system. Water losses are thus minimized to the strict requirement. Advantage: partial continual renewal of the shower water, unlike systems involving full recirculation.

Description:
OBJECT OF THE INVENTION 
       [0001]    The present invention relates to a water recirculation device for shower installations. 
       PRIOR ART 
       [0002]    For ecological reasons, it is increasingly necessary to reduce consumption as much of energy as of water in general and drinking water in particular. 
         [0003]    On this subject, the document FR2827147 describes a shower system enabling recirculation of the water from a shower device. This system comprises a plurality of mixers and a solenoid valve controlled by means of a control panel. This system is complex and allows only closed-circuit operation. 
         [0004]    The document WO2008/031139 describes a shower base structure for a shower having a water recirculation circuit. This base comprises a substantially flat bottom and a reservoir. The reservoir comprises a first outlet adapted to allow to pass through it water to be used by the recirculation circuit and a second outlet adapted to allow to pass through it water to be evacuated. In operation, when the passage of water to the drain is blocked, incoming water in contact with the bottom flows into the reservoir where it accumulates to a depth sufficient substantially to cover the first outlet. 
         [0005]    Moreover, WO/2004/101902 describes a water recycling system used in a shower installation including a switching device for changing from the water recycling state to a non-recycling state in which water is drained from the installation via a drain in order to be eliminated. The switching device functions in the non-recycling state to allow water to flow to the drain in order to be evacuated and in the recycling state to divert water flowing to the drain so that it is discharged via an outlet orifice and to reduce or to stop the flow of water from the water supply to the outlet orifice. 
         [0006]    However, these devices have the drawback of not allowing continuous partial renewal of water. 
       AIMS OF THE INVENTION 
       [0007]    The present invention aims to provide a water recirculation system for relaxing showers free of the drawbacks of the prior art. 
         [0008]    In particular, the present invention aims to simplify existing devices and to propose a mode of operation allowing temperature regulation during recirculation. 
         [0009]    The advantages of the invention will become more clearly apparent in the light of the description of the invention given hereinafter. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention concerns a shower system water recirculation device comprising the following elements:
       a cold water feed connection;   a hot water feed connection;   a three-port valve the inlet of which is connected to the cold water feed, said three-port valve allowing selection of a first outlet or a second outlet;   a mixer device comprising a first inlet and a second inlet, the first inlet being connected to the hot water feed and the second inlet to the first outlet of the three-port valve;   mixed water spray means connected to the outlet of the mixer device;   a sprayed water recovery tank comprising an evacuation overflow and a recovery pipe;   pumping means the inlet of which is connected to the recovery pipe and the outlet of which is connected via a check valve device to the second inlet of the mixer device in parallel with the first outlet of the three-port valve,
 
said pumping means being controlled by means of a pressure-switch connected to the second outlet of the three-port valve.
       
 
         [0018]    According to preferred modes of the invention, the recirculation device includes at least one of the following features or any appropriate combination thereof:
       the device further comprises a micro-leak on the hydraulic circuit of the pressure-switch allowing reduction of the pressure in this circuit;   the device further comprises a filter device on the water recirculation circuit;   the filter device comprises a support and a plane type consumable filter, the consumable filter preferably being made of paper, cloth or a polymer membrane having controlled porosity;   the device further comprises a second pressure-switch connected to the outlet of the pumping means allowing stopping of the pump on closure of the mixer device;   the mixer device is of the thermostatic type;   the device comprises only one mixer device;   the three-port valve is a direction reverser;   the reverser is controlled by a level gauge placed in the recovery tank.       
 
         [0027]    The present invention also concerns a shower system comprising the device in accordance with the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURE 
         [0028]      FIG. 1  is a diagram representing one example of a device in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    The present invention concerns a shower device allowing water and energy saving by recirculating some of the shower water. After transient use during which the shower functions in the conventional manner, a pump  8  is actuated to recirculate the shower water. This initial transient period allows washing or relaxation and filling of a transient reservoir  16 , while the subsequent flow allows a relaxing shower without this increasing the consumption of hot water in an exaggerated manner. 
         [0030]    The basic principle of the invention is to connect a mixer device  3 , preferably a thermostatic device, directly to the hot water feed  15  and the cold water feed  1 . In parallel with the hydraulic circuit of the cold water distribution network  1 , the cold water inlet of the mixer device  3  is also connected to a recirculation system pumping by means of a pump  8  water falling into a recovery tank  16 . In recirculation use, the pump  8  is actuated and the cold water feed  1  is shut off. 
         [0031]    In such a device, the mixer device maintains a flow of hot water just sufficient to compensate the heat losses from the water circulating in the system. The waste of water is therefore minimized to what is strictly necessary. This topping up of the hot water also has the advantage of continuous partial renewal of the shower water, in contrast to total recirculation systems. 
         [0032]    The recirculation circuit preferably includes a check valve type device  6  so as to prevent any leakage via this circuit during the initial transient phase or generally during use in the conventional mode (with no recirculation). 
         [0033]    The invention preferably comprises means allowing, during use, changing from conventional operation (with no recirculation) to operation with recirculation. In particular, these means will simultaneously shut off the feed of cold water and command starting of the pump  8 . These means will preferably comprise a three-port valve  2  connecting the cold water network either directly to the cold inlet of the mixer device (position  2   a ) or to a hydraulic control circuit (position  2   b ). In this case the hydraulic control circuit comprises a pressure-switch  5  controlling the supply of electrical power to the pumping device  8 . 
         [0034]    The three-port valve  2  is advantageously of the reverser type, allowing two stable positions ( 2   a,    2   b ). 
         [0035]    The hydraulic control circuit preferably comprises a micro-leak  14  allowing the pressure to be reduced quickly when the device is stopped (or on returning to the conventional mode). The outlet of this micro-leak  14  will preferably be connected to the recirculation circuit by means of a connection  11  on the upstream side of the pump  8 . 
         [0036]    The pressure-switch  5  will advantageously allow supply of power to a voltage converter (transformer) only when the pressure in the control circuit is greater than a predetermined threshold. This voltage converter will then power the pump  8  at low voltage so as to reduce the risks of electrocution. 
         [0037]    Being part of a shower device, the outlet of the mixer device is connected to a sprayer device  4  of shower handset or sprayer manifold type. 
         [0038]    The tank  16  will generally simply be a shower tray or “tub” the drain of which will have been blocked by means of a pipe  13  forming an overflow. The blocking means will for example be a pipe 5 cm high equipped with a conical seal at its base, placed in the trap of the container (bathtub or shower tray). 
         [0039]    The bottom of the reservoir could optionally be covered with duckboards or any other device allowing the user&#39;s feet to be raised without this reducing the flow of water. 
         [0040]    Alternatively, during installation or renovation of a shower tray an overflow trap is placed at a height of more or less 10 cm on one of the walls of the container and connected to the siphon. An inlet orifice (small trap) will advantageously be placed on the flank in the vicinity of the bottom of the reservoir and connected to the inlet of the 12 V pump for closed circuit pumping. This disposition on the flank of the reservoir allows recirculation of heavier particles that settle on the bottom of the reservoir to be prevented. Where necessary this allows reduction of clogging of the filter and/or of wear of the pump by abrasive particles such as sand. A device will furthermore allow draining of the reservoir after recirculation for hygiene reasons. 
         [0041]    Below the overflow level, a pipe  12  connected to the inlet of the pump allows pumping of recirculated water. 
         [0042]    The recirculation circuit will preferably comprise a filter device  10 . This device  10  will preferably be disposed between the water recovery pipe  12  and the pump  8 . This filter device will advantageously comprise a disposable filter of the filter paper or microporous membrane type and a “grid” type support. 
         [0043]    A second pressure-switch  9  will advantageously regulate the outlet pressure of the pump  8 . In particular, this pressure-switch will cut off the supply of power to the pump  8  during momentary stopping by closure of the mixer device  3 . This stopping will be induced by a pressure rise in the line on momentary closing of the mixer. 
         [0044]    The device of the invention allows considerable water saving. Indeed, tests have shown that the consumption of a shower in the conventional mode is approximately 11 liters per minute whereas in the recirculation mode in accordance with the invention the same shower had a consumption of 0.7 liter per minute. These figures are illustrative and depend of course on the parameters of the installation, such as the hot water and cold water temperatures. Furthermore, only 0.7 l/min of hot water is used, the hot water being mixed with lukewarm recirculated water (at approximately 36° C. as against typically 10° C. for the cold water supply), which represents a substantial energy saving. 
         [0045]    Having a minimum overall size, the device of the invention can be fitted to the existing hardware of the shower or the bath without modification. 
       Description of a Preferred Embodiment of the Invention 
       [0046]    In a preferred form of the invention the recirculation circuit is controlled by the hydraulic pressure (F,  1  cold water) of the distribution network, whether this be a drinking water distribution network or a hydrophore unit or any other hydraulic network with a minimum pressure of 0.5 bar. 
         [0047]    A direction reverser (three-port valve in position  2   b ) preferably shuts off the main cold water inlet to the mixer  3  and directs it to a pressure-switch  5  that actuates a relay allowing electrical power to flow from a 12 V transformer to a 12 V pump  8 . 
         [0048]    The hydraulic control line  7  of the pressure-switch is connected to the inlet  12  of the pump by a connection via an in-line micro-leak  14 . This micro-leak  14  allows the control pressure of the pressure-switch to be released at the moment at which the position of the reverser is changed (three-port valve  2  in position  2   a ) to return to the conventional mode of operation (connecting the feed for the cold water distribution circuit  1  directly to the cold water inlet of the mixer). In this position an in-line check valve  6  prevents the pressure reaching the pump  8  and maintains the conventional line pressure. 
         [0049]    The reserve of pumped water is a bathtub or a shower tray in which a minimum depth of water is maintained so that the inlet pipe is immersed. The quantity of water in this reservoir is limited in order to avoid having to consume too great a quantity of water at working temperature (36°) in the initial transient phase. 
         [0050]    A filter  10  filters particles in the closed circuit aspirated by the pump  8  via the pipe  12 . The filter is composed of a stainless steel grid supporting a paper filter for optimum retention of particles. This paper filter is a consumable item that can be recycled, for reasons of hygiene and convenience, and the stainless steel filter (grid) is cleaned manually under a tap. The filter area is 36 cm 2  and the paper filter operates effectively before it becomes saturated for at least 90 minutes in water without soap and at least 60 minutes for a complete shower with soap. 
         [0051]    During use in a closed circuit there is a pressure-switch  9  that cuts off the 12 V power supply of the pump  8  at the moment at which the water inlet of the mixer is shut off to stop showering momentarily. 
         [0052]    The overflow  13  is preferably a tube approximately 5 cm high with a conical rubber seal at the base placed in the original drain trap. 
         [0053]    In one particular example, for a conventional 10-minute shower, a conventional shower will represent a consumption of 110 l, including approximately 55 l of hot water. A shower of the same duration in accordance with the invention will comprise for example one minute in the conventional mode (11 l, i.e. 5.5 l of hot water and 5.5 l of cold water) to fill the tray (until the inlet pipe is immersed), 8 minutes in the recirculation mode, i.e. 0.7*8=5.6 l of hot water, followed by 1 minute rinsing in the conventional mode, i.e. 11 l of water. In total, in this example, the invention has allowed consumption to be reduced to 11 l of cold water and 16.6 l of hot water, i.e. a saving of 44 l of cold water and 38.4 l of hot water, which represents a substantial saving.