The present invention relates to a recirculation shower. During a shower bath such recirculation showers continuously recirculate water, so large flow rates can be achieved with only limited amounts of water. Recirculation showers typically comprise a water collection reservoir, a shower head and a pump for circulating water between the water collection reservoir and the shower head.

Such recirculation showers are mainly used as wellness showers. Usually, the wellness showers are combined with a conventional shower, so a user may first wash himself and then, after the spent soapy water has been rinsed away, the user can switch over to the recirculation shower for enjoying the comfort of a wellness shower.

An example of such a combined shower system is disclosed in WO 2014/206685. Due to the high circulation rate the recirculated water cools relatively quickly. A thermostatic mixer tab is used to mix the recirculated flow with fresh hot water in order to keep the temperature at a desired level.

This creates a risk that water from the recirculation flow might contaminate tap water in the public water supply

network. Moreover, a single pump is used to circulate spent water in a circulation mode and to supply fresh water in a conventional shower mode. Most jurisdictions require a strict separation of the public water supply network from any source of possibly polluted water, such as recirculation water in a Jacuzzi bath. The shower system of WO 2014/206685 does not seem to meet such requirements.

Another drawback of the shower system of WO 2014/206685 is that the pump is at a distance above the water level in the water catchment basin below the shower floor. When the shower is switched to recirculation mode, it will take considerable time and pump power for starting up the circulation flow. The object of the invention is to provide a shower system overcoming these problems.

The object of the invention is achieved with a

recirculation shower comprising a pump for circulating water through the recirculation shower via a circulation flow path, a water tank fluidly connected to an inlet of the pump and positioned at a higher level than the pump, and a fresh water supply for feeding the water tank.

This way, the suction side of the pump is always directly in contact with pumpable water. The circulation flow can start as soon as the pump is activated. Smaller pumps with less power can be used.

In a particular embodiment, the recirculation shower has a shower head and a water collection reservoir arranged to collect water dispensed by the shower head, wherein the pump is arranged to circulate water via the circulation flow path from the water collection reservoir to the shower head. The circulated water is circulated via the water collection reservoir but does not pass the water tank, which is outside the circulation flow path. The water collection reservoir may for example arranged to collect water from a floor of the shower system via a drain, e.g., by gravity, the floor being below the shower head for supporting a user making use of the shower .

The fresh water supply may for example be thermostatically controlled. This will ensure that after activation of the pump the recirculation flow will start with a water temperature set by the user.

The tank, or the line connecting the tank to the pump, may be provided with a valve. A control unit may be configured to open the valve when the pump is activated and to close the valve once the recirculation flow has reached a set flow rate.

In a specific embodiment the fresh water supply comprises a tap with an outlet at a distance above a maximum water level of the water tank. This isolates the water supply from any water in the tank or anywhere else in the recirculation flow path of the recirculation shower. Such a tap can safely be connected to a public water supply network.

The tank may for instance comprise an overflow outlet. An overflow line may be provided between the overflow outlet of the tank and a water collection reservoir fluidly connected to the inlet of the pump.

Optionally, the recirculation shower may have two water tanks fluidly connected to the inlet of the pump, e.g., a cold water tank fed by a cold water supply and a hot water tank fed by a hot water supply. The two tanks may for instance have respective outlet lines connecting to the pump inlet and being provided with proportional valves under the control of a control unit for adjusting the water temperature of water fed to the pump inlet. This way, the two tanks can be used for mixing fresh hot water into the recirculation flow during a recirculation shower bath to keep the water temperature at a level set by a user. The second tank may for example be fed by a hot water supply line while the first tank is fed by a cold water supply line. In such a case, the two tanks may both comprise an outlet line with a proportional valve. Downstream the proportional valves the two outlet lines may combine to form a single pump feeding line containing a temperature sensor. A control unit can be used to control the proportional valves to minimize the difference between a temperature measured by the sensor and a set value.

Optionally, one or both of the tanks may comprise an overflow outlet, e.g., with an overflow line running to the water collection reservoir. Optionally, one or both of the two tanks may comprise a float for stopping water supply to the tank if a maximum level is reached. In a specific embodiment, the cold water tank may comprise an overflow outlet, while the hot water tank comprises a float. An alternative system for mixing fresh hot water into the recirculation flow may comprise a separate tap spaced from the recirculation flow path. A control unit may control water temperature and/or flow rate of a water flow dispensed from the tap, in response to a signal received from one or more temperature sensors in the recirculation flow path.

The invention also relates to a shower system comprising a conventional shower with hot and cold water supply lines and a recirculation shower as disclosed above, the recirculation shower defining a circulation flow path isolated from hot and cold water supply lines of the conventional shower.

The shower system may comprise a user interface allowing a user to switch between a recirculation mode and a conventional shower mode. The user interface may also enable him to control the temperature and/or flow rate of the shower water dispensed by the conventional shower and/or the recirculation shower.

The invention is further explained with reference to the accompanying drawings showing exemplary embodiments.

Figure 1: schematically shows a first embodiment of a shower;

Figure 2: schematically shows a second embodiment of a shower .

Figure 1 shows a wellness shower system 1. The shower system 1 combines a recirculation shower 2 with a separate conventional shower 3, both having shower heads 4, 5 arranged above a water collection reservoir 6. The water collection reservoir 6 is provided with an overflow outlet (not shown) . A recirculation line 8 fluidly connects the water collection reservoir 6 to the shower head 5 of the recirculation shower 2. A pump 10 is arranged in the recirculation line 8 to circulate water from the water collection reservoir 6 to the shower head 5 of the recirculation shower 2. The water collection reservoir 6 is arranged below a floor 7 of the shower system 1. A drain is provided to guide water from the floor 7 to the water circulation reservoir 6.

The shower system 1 comprises a thermostatically

controlled hot and cold water mixing tap 12 connected to a supply line 13 for hot tap water and a supply line 14 for cold tap water. Proportional valves 16 in the supply lines 13, 14 are configured to regulate the flows in the supply lines 13, 14 to obtain tap water of a desired temperature. The tap 12 has an outlet at least 2 cm above the highest possible water level in the water collection reservoir 6, i.e., the water level in the water collection reservoir when the drains are clogged .

Although not shown in Figure 1, the tap may be hidden from view, e.g., by a front panel presenting a user interface for user control of the shower.

The conventional shower 3 is operatively connected to the public water supply network with hot and cold water supply lines 20, 21 which are strictly separated from the

recirculation flow. A motorized thermostat 22 allows a user to maintain the shower water at a desired temperature selected via a user interface at the front panel.

The shower system 1 further comprises a water tank 28 fluidly connected to an inlet 29 of the pump 10. The water tank 28 is positioned at a higher level than the pump 10 so the inlet 29 of the pump is always under water. A fresh tap water supply 35 feeds the tank via a supply line 36 branched off from a supply 37 line feeding the conventional shower 3. The feeding line 36 is downstream the motorized thermostat 22 so the tank 28 is fed with water of the same temperature as the water dispensed by the conventional shower 3. The tank 28 is provided with an overflow outlet 39 connected to an

overflow line 40 leading to the water collection reservoir 6. The user interface communicates with a control unit allowing a user to switch between a circulation flow via the recirculation shower 2 and a drained shower flow via the conventional shower 3.

The wellness shower system 1 further comprises a drain 24 and a controllable drain valve 25 for selectively closing or opening the drain 24. When the user switches over to the conventional shower 3, the control unit activates the drain valve 25 to open the drain 24. The user can wash himself with soap and the spent soapy water is drained via the open drain 24. Meanwhile, the tank 28 is fed with fresh tap water of the same temperature as the water dispensed by the conventional shower 3. When the tank 28 is filled, excess water will flow via the overflow outlet 39 and the water collection reservoir 6 to the drain 24.

After finishing washing by means of the conventional shower 3 the user may switch over from the conventional shower 3 to the recirculation shower 2 via the user interface. The control unit activates the drain valve 25 to close the drain 24 and opens the mixing tap 12, but does not yet switch off the conventional shower 3. Water is collected in the water collection reservoir 6 until a level sensor 27 in the water collection reservoir 6 detects that the water lever in the water collection reservoir 6 has reached a desired minimum level. At that moment the pump 10 is activated and the

circulation flow starts directly. After the circulation flow reaches a desired flow rate, set by the user, a control unit switches off the conventional shower 3 and close off the line between the tank 28 and the pump inlet 29. The shower bath is not interrupted during switching from the conventional shower 3 to the recirculation shower 2.

The user can select and set the water temperature via the user interface. During circulation flow the recirculated water tends to cool down. To maintain the water temperature at the selected level, the tap 12 mixes hot water into the water collected in the water collection reservoir 6, e.g.,

continuously or intermittently. A temperature sensor 18 is provided in the recirculation line 8. The flow rate and/or temperature of the water from the tap 12 is adjusted in response to signals from the temperature sensor 18.

During circulation flow, excess water is discharged from the water collection reservoir via the overflow outlet with a flow rate corresponding to the flow rate of the tap 12.

A filter 31 in the water collection reservoir filters water entering the inlet 29 of the pump 10. A UV-source 32 is integrated in the circulation line 8 to clean the circulated water from microorganisms, for as far as necessary.

Figure 2 shows an embodiment of a shower system 101 having two water tanks 132, 133 instead of one. Just like the

embodiment of Figure 1, the shower system 101 combines a recirculation shower 102 with a separate conventional shower 103. The shower system 101 comprises a water collection reservoir 104 with an overflow outlet (not shown) . A

recirculation line 108 fluidly connects the water collection reservoir 106 to the shower head 105 of the recirculation shower 102. A pump 110 is arranged in the recirculation line 108 to circulate water from the water collection reservoir 106 to the shower head 105 of the recirculation shower 102.

The conventional shower 103 is operatively connected to the public water supply network with hot and cold water supply lines 120, 121 which are strictly separated from the

recirculation flow. A motorized thermostat 122 allows a user to maintain the shower water temperature at a desired level selected via a user interface at the front panel.

Two water tanks 132, 133 are fluidly connected to an inlet 129 of the pump 110. Both water tanks 128 are positioned at a higher level than the pump 110. The tanks 132, 133 include a cold water tank 132 and a hot water tank 133. The cold water tank 132 is fed by a cold tap water supply line 136. The hot water tank 133 is fed by a hot tap water supply line 137. The cold water tank 132 is provided with an overflow outlet 139 connected to an overflow line 140 leading to the water

collection reservoir 106. The hot water tank 133 is provided with a float 138 preventing overflow of the hot water tank 133. Both tanks 132, 133 comprise an outlet line 141 provided with a proportional valve 142. Downstream the proportional valves 142 the two outlet lines 141 join to form a single line 143 connecting to the inlet 129 of the pump 110.

The proportional valves 142 are controlled by a control unit (not shown) . The pump feeding line 143 contains a temperature sensor 144. If the temperature measured by the sensor 144 deviates from a set temperature, the control unit controls the proportional valves 142 to adjust the temperature of the water fed to the pump feeding line 143. In this configuration, a separate tap for the supply of fresh hot water is not needed anymore.