CN112752886A

CN112752886A - Shower with additive dispenser

Info

Publication number: CN112752886A
Application number: CN201980062632.1A
Authority: CN
Inventors: E·莫克; M·罗塞莱
Original assignee: Gjosa SA
Current assignee: Gjosa SA
Priority date: 2018-10-02
Filing date: 2019-10-01
Publication date: 2021-05-04
Anticipated expiration: 2039-10-01
Also published as: EP3861178A1; EP3861178B1; WO2020070154A1; CN112752886B

Abstract

A dispenser arranged for dispensing water with an additive, in particular a shower, comprising: a shower head (14); a shower hose (13) for supplying water to the shower head (14); at least one additive supply source (21); at least one additive line (16) for supplying additive from the at least one additive supply source (21) to the showerhead (14); and wherein the spray hose (13) and the at least one additive line (16) are flexible and optionally bonded to each other. Furthermore, the dispenser comprises at least one additive pump (9) for delivering the additive from the at least one additive supply source (21) to the at least one additive line (16); and the at least one additive pump (9) is arranged and controlled to control the delivery of the additive to the shower head (14).

Description

Shower with additive dispenser

Technical Field

The present invention relates to the field of sanitary equipment. It relates to a dispenser and a corresponding method arranged for dispensing water with an additive as described in the preambles of the respective independent claims.

Background

US8'490'891 discloses a shower head and a washing fluid supply apparatus in which a duct for washing fluid is arranged within a water pipe leading from the supply apparatus to the shower head. The supply device includes a piston that generates pressure to deliver the washing fluid to the showerhead via its pipe. The piston is activated by the pressure of the tap water. In a showerhead, a pair of manually operated valves allow switching between delivery of water or a foam mixture of water, wash fluid and air. This mixture is generated in the showerhead and exits the showerhead at another outlet than the water. It is not possible to control the volume of washing fluid dispensed or its concentration within the mixture. The valve system in the showerhead is mechanically complex and must be manually operated.

US2007/235091 shows a water tap for a kitchen sink having two ports for connection to cold and hot water supply lines and a third port for connection to a special water supply line, for example for supplying filtered or carbonated water. Using two concentric hoses, the control valve selects whether to supply mixed water or special water to the discharge head.

WO2007/004050 shows separate delivery of treated water and tap water, comprising flexible hoses for separately delivering treated water and tap water to establish a connection between nozzles provided at two separate delivery points and a dispensing unit for separately supplying treated water and tap water.

EP0313913a2 discloses a mixing device in a shower head remotely controlled by a button on the shower head, having a base unit with a pump. The additive line may extend parallel to the water line leading to the showerhead so that the additive is dispensed through the valve in front of the showerhead.

WO2018/122223a1 and WO2018/122206a1 disclose an apparatus and method for dispensing a mixture of water and additives via a showerhead and parameters related to a user of the apparatus.

US2013/0291947a1 discloses a faucet with an additive line leading in parallel with the water pipe to a mixer at the faucet outlet.

Disclosure of Invention

A possible object of the present invention is therefore to create a dispenser arranged for a dispenser for dispensing water with an additive of the initially mentioned type, which dispenser overcomes the aforementioned drawbacks.

Another possible object of the invention is to create a dispenser that allows precise control of at least one of the delivery time, volume or concentration of the additive being delivered.

These objects are achieved by a dispenser according to the claims.

The dispenser, which may be in particular a shower, is arranged for dispensing water with an additive. It includes:

a shower head;

a spray hose for supplying water to the spray header;

at least one additive supply source;

-at least one additive line for supplying additive from the at least one additive supply source to the showerhead;

wherein the spray hose and the at least one additive line are flexible and optionally bonded to each other;

wherein

The dispenser comprises at least one additive pump for delivering the additive from the at least one additive supply source to the at least one additive line;

an additive pump is arranged and controlled to control delivery of the additive to the showerhead.

In other words, at the end of the additive line rather than at the beginning of the additive line, the delivery of the additive to the showerhead and thus the delivery of the water flow into the showerhead is not controlled by valves or the like in the showerhead itself. This allows the mixing of the additive with the water in the showerhead itself to be controlled in a precise manner, but without increasing the structural complexity of the showerhead.

In an embodiment, the additive pump, when connected to the mains water supply, is arranged to increase the additive pressure in the additive line above the water pressure in the water supply line. The additive is typically a liquid. Another liquid than water may be used.

In an embodiment, the additive outlet arranged at the end of the additive line is arranged in the shower head.

This allows to arrange a mixing device for mixing the additive and the water in the shower head downstream of the additive outlet. The mixing device or mixing unit may be a static mixer comprising elements that create turbulence in the mixed flow of water and additive. This may be done by shaping the conduit for mixing the flow and/or by incorporating elements into the conduit for creating turbulence in the flow.

In an embodiment, the showerhead downstream of the additive outlet comprises a conduit for maintaining an at least approximately laminar mixed flow until the mixed flow reaches the region of the outlet of the showerhead. In particular, the tube may have an uninterrupted wall, such as an edge, ledge or protrusion that protrudes into the tube.

This may help to reduce energy losses in the mixing flow and thus increase the effectiveness of the shower to produce a spray.

In an embodiment, an additive line at the additive outlet opens into a space within the showerhead for directing water to the outlet of the showerhead.

In other words, the end of the additive line is free of valves. When the pressure in the additive line is lower than the water pressure in the showerhead, the additive will be pushed back or retained in the additive line.

In an embodiment, the additive outlet is arranged to reduce or eliminate a venturi effect of introducing the additive into the water stream.

In an embodiment, the additive outlet comprises a check valve. This prevents water from flowing back into the additive line.

In an embodiment, the check valve is designed to open only if the pressure difference across the check valve exceeds a threshold value.

This prevents the additive from flowing into the water stream when the additive pump is not operating. The threshold for opening the check valve may be, for example, 0.1 bar or 0.5 bar or 1 bar.

In an embodiment, the check valve is a diaphragm valve, such as a duckbill valve or a duckbill valve.

In an embodiment, the additive pump is a volumetric pump, in particular a peristaltic pump or a diaphragm pump.

This allows controlling the amount of additive, in particular the volume of additive, delivered by controlling the motion of the additive pump. It is not necessary to measure the flow of additive. The additives can be dosed precisely.

In an embodiment, the at least one additive line and the spray hose extend parallel to each other.

In an embodiment, the at least one additive line and the spray hose are attached to each other.

In an embodiment, the at least one additive line and the spray hose have a length of at least 80 centimeters or at least 1 meter.

In an embodiment, the at least one additive line is arranged within the shower hose, and in particular

The inner diameter of the shower hose is between 8 mm and 12 mm, in particular at least about 10 mm,

there is exactly one additive line in the spray hose and the outer diameter of the additive line is 3 mm to 6 mm, in particular at least approximately 4 mm.

In an embodiment, the inner cross-section of the spray hose, still used for guiding the water, comprising one or more additive lines has an area of less than 60 square millimeters or less than 50 square millimeters or less than 40 square millimeters or less than 30 square millimeters.

In embodiments, the water pump is designed to deliver a flow of water through the showerhead at a rate of less than 5 liters/minute, or less than 4 liters/minute, or less than 3 liters/minute, or less than 2 liters/minute.

Such low flow rates are advantageous in combination with the fact that the internal area of the spray hose is reduced by the presence of the additive line: by arranging one or more additive lines within the spray hose, the remaining cross-section of the spray hose through which water can be delivered to the showerhead is reduced. However, in combination with a low flow distributor, this proves advantageous. Low flow distributors such as showers require a smaller inner diameter of the spray hose in order to reduce the delay caused by the time it takes for water to travel along the spray hose. The delay should be small because the change should be felt as quickly as possible at the showerhead as the user adjusts the water temperature. In summary, despite the reduced inner cross-section due to the additive lines, spray hoses having an outer diameter similar to conventional spray hoses can be used. For the end user, the overall process of the spray hose is the same as a conventional spray hose, which is advantageous.

In an embodiment, the additive line has an inner diameter of between 1 mm and 3 mm or 4 mm, in particular at least about 2 mm.

In an embodiment, the dispenser comprises two or more additive lines, each with an associated additive supply and optionally an associated additive pump.

This allows a variety of dispenser application specific additives to be dispensed and mixed with the water in a controlled manner.

For example, in dispensers designed for hair care, the individual additives may be different types of shampoos, conditioners, colorants, and the like.

In embodiments, the dispenser may include a selective activation device for activating the dispensing of one or more additives. The selective activation means may comprise a plurality of activation switches or buttons, each associated with a particular additive. The selective activation means may comprise a selection element for selecting an additive from two or more additives and an activation switch or button for activating the dispensing of the selected additive.

Each of the one or more additives can be associated with an additive control input. This may be an input device or input element that allows the additive amount to be adjusted. This quantity can be expressed for example as,

volume or weight of additive to be dispensed in a single "shot" of additive;

the volume or weight of additive to be dispensed per time unit of continuous delivery of the mixture of additive and water;

the concentration of the additive to be dispensed in a single "shot" or continuously dispensed in the water. The concentration may be expressed in terms of the relative weight or relative volume of the additive relative to the water.

For example, concentrations of 0.5 grams to 1 gram of additive in 10 grams of water may be used.

The additive pump may be controlled to deliver a corresponding amount or volume of additive given the desired additive concentration and delivery rate or flow rate of the water pump.

Or conversely, if the amount or desired concentration of additive is given, specifying a "charge" of diluted additive in the water, then the water pump may be controlled to deliver a corresponding amount of water during the "mix delivery time".

For one or more additives, a set of dispensing parameters may include parameters specifying the amount of additive and optionally the duration for which the additive is dispensed. The duration may be specified relative to a reference time point. Thus, for one or more additives, the set of dispensing parameters may specify a time-varying volume trace that is initiated, for example, by triggering an activation button.

Such a trajectory may simply specify the dispensing of two or more additives simultaneously, each additive having a particular concentration. Or the trajectory may specify the injection of a first additive (or combination of additives) dispensed first, and the injection of a second additive (or different combination of additives) dispensed after a certain time, etc.

In an embodiment, the dispensing may be terminated by a user input, for example by the same or another activation button, and/or by turning off the water supply to the dispenser.

In an embodiment, a dispenser is configured to store at least one set of dispensing parameters specifying the dispensing of one or more additives and to determine a set of dispensing parameters to be used in the operation of the dispenser by:

selecting one of said sets of allocation parameters, and/or

Modifying a set of stored allocation parameters, and/or

Receiving a stored set of allocation parameters from another device

And based on at least the following information:

information identifying an operator of the dispenser;

information identifying the person or object to be treated by the dispenser;

information specifying the additive or additives or the characteristics of the additive or additives.

In this way, the operation of the dispenser can be adapted to the preferences of the user and/or the current task. In hair care, in particular professional hair care, the person to be treated is a client of the hairdresser and the stored allocation parameters are associated with the client. They may reflect the preferences of the customer and/or characteristics appropriate to the customer's hair.

Furthermore, it is possible to adapt the operation of the dispenser to the physical and chemical characteristics of the one or more additives. Such characteristics may be solubility, viscosity, concentration of the agent contained by the additive, etc.

In an embodiment, the water pump is designed to generate a pressure in the spray hose of at least 4 bar, at least 5 bar, at least 6 bar, at least 7 bar or at least 8 bar.

Such a relatively high pressure allows atomizing water and/or a mixture of water and additive, thereby generating a fine mist. Although this is a fine mist with small droplets, the droplets have high kinetic energy. This makes them effective in cleaning and rinsing. This occurs when the fluid flow rate is relatively low.

In particular, the combination of a low flow rate with spraying or atomization at a relatively high pressure is advantageous for hair care applications, and in combination with the dispensing of additives as described herein. The combination allows for a fast switch between dispensing and flushing of a mixture of water and one or more additives. As previously mentioned, the flush may be at a low flow rate due to the effects caused by the high pressure. The low flow rate is advantageous in view of the reduced diameter of the spray hose due to the additive line inside the hose.

In an embodiment, the shower head is arranged to dispense water and a mixture of water and additive through the same outlet of the shower head, in particular through an outlet that produces a spray of liquid droplets.

In an embodiment, the showerhead is configured to dispense a liquid, such as water or a water-based mixture, by generating impinging jets of the liquid.

Corresponding outlets using impinging jets are disclosed, for example, in US8458826 or WO2011/054120a, which are hereby incorporated by reference. They usually have one or two or three nozzle groups, each having two or more nozzles for generating impinging liquid jets. Upon collision, the liquid atomizes, producing a fine mist with droplets. Spraying at increased pressure increases the kinetic energy of the droplets.

In an embodiment, the water pump is arranged downstream of the water valve.

In an embodiment, no water valve is present. The water pump may then also function as a water valve.

In an embodiment, the water pump and the additive pump, and optionally at least one of a water valve, a pressure activated switch, a microcontroller, are arranged together in a single housing in the base unit.

A method for operating a dispenser for dispensing water with an additive, comprising the following steps for dispensing a portion of the additive (in the form of a mixture of additive and water):

starting with the operating mode in which water is delivered to and sprayed through the showerhead;

reducing or stopping the delivery of water to the showerhead;

o for example, by partially or completely closing the water valve and/or reducing the delivery rate of the water pump or stopping the water pump;

delivering additive through an additive line to the showerhead while reducing or stopping water delivery;

restart delivery of water to the showerhead or increase the delivery rate to the same rate as or a different rate than before the reduction or stop.

In an embodiment, said delivering of said additive is done by delivering a preset amount, in particular a portion, of additive. This can be done as a single "shot" of additive.

In an embodiment, said delivering of said additive is done by delivering a preset amount of at least one additive per unit time. This corresponds to a continuous flow of a mixture of water and additive and a preset concentration of at least one additive.

In an embodiment, the method comprises the following steps

Restarting the delivery of water only for a short time called "mixture delivery time" and stopping said delivery of water to said shower head after said "mixture delivery time".

As already mentioned above, these amounts and durations (or the respective frequencies) as dispensing parameters may be adjusted according to the user, the task and/or the additive.

In an embodiment, the method comprises the steps of:

during the "mixture delivery time", operating the water pump to deliver a quantity of water corresponding to the volume of the portion of additive delivered by the additive pump, so as to obtain a controlled concentration of additive in the water during the delivery of the mixture.

For example, given 0.5 to 1 gram of additive delivered by an additive pump (e.g., corresponding to 0.5 to 1 ml), they are dissolved in 16 grams of water, which is achieved by delivering 2 liters per minute over half a second of operating the water pump.

According to another aspect and corresponding other embodiments, the mixing of the additive and the water occurs before the spray hose. The additive line thus supplies the additive to the mixing unit before being connected to the spray hose. Other elements described herein may be used in conjunction with this aspect as long as they are compatible.

The description of the invention will primarily refer to water as the base liquid being dispensed alone or mixed with one or more additives, it being understood that the invention may be practiced using other liquids instead of water.

Other embodiments are apparent from the dependent claims. Features of the method claims may be combined with features of the apparatus claims and vice versa.

Drawings

The subject matter of the invention will be explained in detail hereinafter with reference to embodiments illustrated in the accompanying drawings, which schematically show:

FIG. 1 is a dispenser for an additive;

FIG. 2 is a dispenser for an additive having an additive line within a spray hose; and

fig. 3 is a dispenser for several additives.

The reference symbols used in the drawings and their meanings are listed in summary form in the list of reference symbols. In principle, identical components have the same reference numerals in the figures.

Detailed Description

Figure 1 schematically shows a dispenser comprising a base unit 4, a spray hose 13 and a spray head 14. The base unit 4 is supplied with water via a water supply fitting 1, such as a manually operable tap or valve, an optional pressure relief valve 2 and a water supply line 3. In an embodiment, no valve is present in the water supply fitting 1 or at the water supply fitting 1. The water valve 15 must then be designed to handle the tap water pressure. The base unit 4 supplies water to a shower head 14 through a shower hose 13. The base unit 4 comprises a water valve 15, the water valve 15 being supplied by the water supply line 3 and being arranged to be controlled by a control signal, for example from a microcontroller 18. The pressure activated switch 5 is arranged to provide a signal dependent on the water pressure after the water valve 15. Water from the water valve 15 passes through the pump water fitting 6 to the water pump 12. The water pump 12 delivers water to the shower hose 13 and thence to the shower head 14. The base unit 4 comprises an additive supply 21 and an additive pump 9 which supplies additive to the additive line 16 and thence to the showerhead 14. The additive supply 21 may be arranged inside the base unit 4 or may be attached to the outside of the base unit 4. Existing one-way or refillable containers may be used. The additive line 16 terminates in an additive outlet 20, where the additive is added to the water flow delivered by the spray hose 13. Optionally, a check valve 11 is arranged at the end of the additive line 16.

The microcontroller 18 is arranged to control the water valve 15, the water pump 12 and the additive pump 9. The microcontroller receives input signals from the aforementioned pressure activated switch 5 and optional user input devices such as activation of a push button or switch 17 and/or an additive amount or concentration controller 19. The microcontroller 18 may be arranged to start delivering the mixture of water and additive when the activation switch 17 is activated. The microcontroller 18 may be arranged to control the amount of additive to be delivered, or the concentration of additive in the water, in dependence on an input signal of the additive amount or concentration controller 19.

In other embodiments, the water valve 15 is operated directly by the pressure activated switch 5.

The activation press button or switch 17 may be disposed on the base unit 4, or may be disposed on a remote unit remote from the base unit 4. For example, an activation push button or switch 17 may be disposed in the foot pedal or in the shower head 14. The switch signal from the activation switch 17 may be communicated to the microcontroller 18 via a wireless or wired link.

Likewise, the additive concentration controller 19 may be part of the base unit 4 or may be disposed on a remote unit from the base unit 4. Information from the additive concentration controller 19 may be communicated to the microcontroller 18 via a wireless or wired link.

The activation button 17 and/or the additive concentration controller 19 may be implemented in a dedicated device or by software on a general purpose device such as a smart phone or other portable communication device.

Fig. 2 shows the same elements as fig. 1, but with an additive line 16 extending through the spray hose 13.

Fig. 3 shows the same elements as fig. 1, but with a plurality of additive supply sources 21, additive pumps 9 and additive lines 16. Further, the additive concentration controller 19 includes a corresponding plurality of controller inputs, one for each additive.

In other embodiments, starting from the configuration of fig. 2 or 3, the order of the water valve 15 and the pressure activated switch 5 is reversed. The signal from the pressure activated switch 5 is thus dependent on the water pressure in the water supply line 3 before the water valve 15.

The following applies to all configurations of fig. 1 to 3. A single set of additive supply 21, additive pump 9, additive line 16, additive concentration controller 19, etc. and the details of their operation apply to each such set, if more than one set is present.

The additive pump 9 is a pump that allows control of the amount of additive delivered. For example it is a positive displacement pump. The positive displacement pump may be rotary, reciprocating or linear. In other embodiments, the additive pump 9 is a non-positive displacement pump, such as a diaphragm pump, in combination with a sensor for measuring the flow rate produced by the pump.

While the invention has been described in the current embodiment, it is to be clearly understood that the invention is not limited thereto but may be otherwise embodied and practiced within the scope of the appended claims.

Claims

1. A dispenser, in particular a shower, arranged for dispensing water with an additive, comprising:

a shower head (14);

-a shower hose (13) for supplying water to the shower head (14);

-at least one additive supply source (21);

-at least one additive line (16) for supplying additive from the at least one additive supply source (21) to the showerhead (14);

wherein the spray hose (13) and the at least one additive line (16) are flexible and optionally mutually bonded;

it is characterized in that the preparation method is characterized in that,

-the dispenser comprises at least one additive pump (9) for delivering the additive from the at least one additive supply source (21) to the at least one additive line (16);

-the additive pump (9) is arranged and controlled in a manner to control the delivery of the additive to the shower head (14).

2. The dispenser according to claim 1, wherein an additive outlet (20) arranged at the end of the additive line (16) is arranged in the shower head (14).

3. The dispenser of claim 2, wherein the additive line (16) is open at the additive outlet (20) to a space within the showerhead (14) for directing water to an outlet of the showerhead (14).

4. The dispenser according to claim 2, wherein the additive outlet (20) comprises a check valve (11).

5. The dispenser according to claim 4, wherein the check valve (11) is designed to open only if the pressure difference across the check valve (11) exceeds a threshold value.

6. Dispenser according to one of the preceding claims, wherein the additive pump (9) is a volumetric pump, in particular a peristaltic pump.

7. Dispenser according to one of the preceding claims, wherein the at least one additive line (16) is arranged within the spray hose (13), and in particular,

the inner diameter of the shower hose (13) is between 8 mm and 12 mm, in particular at least approximately 10 mm,

-exactly one additive line (16) is present in the spray hose (13), and the outer diameter of the additive line (16) is 3 to 6 mm, in particular at least about 4 mm.

8. A dispenser according to claim 7, wherein the inner cross-section of the spray hose (13) including one or more additive lines (16) still used for guiding the water has an area of less than 60 square millimetres or less than 50 square millimetres or less than 40 square millimetres or less than 30 square millimetres.

9. The dispenser of one of the preceding claims, wherein the water pump (12) is designed to deliver a flow of water through the shower head (14) at a rate of less than 5 liters/minute or less than 4 liters/minute or less than 3 liters/minute or less than 2 liters/minute.

10. Dispenser according to one of the preceding claims, wherein the inner diameter of the additive line (16) is between 1 mm and 4 mm, in particular at least about 2 mm.

11. Dispenser according to one of the preceding claims, comprising more than two additive lines (16), each additive line having an associated additive supply source (21) and optionally an associated additive pump (9).

12. Dispenser according to one of the preceding claims, configured to store at least one set of dispensing parameters that explicitly prescribe the dispensing of one or more additives and to determine a set of dispensing parameters to be used in the operation of the dispenser by:

selecting one of said sets of allocation parameters and/or

Modifying a set of stored allocation parameters and/or

Receiving a stored set of allocation parameters from another device

And based on at least one of the following information:

information identifying an operator of the dispenser;

information identifying the person or object to be treated with the dispenser;

information specifying the additive or additives or the properties of the additive or additives.

13. Dispenser according to one of the preceding claims, wherein the water pump (12) is designed to generate a pressure in the spray hose (13) of at least 4 bar, at least 5 bar, at least 6 bar, at least 7 bar or at least 8 bar.

14. Dispenser according to one of the preceding claims, wherein the shower head (14) is arranged to dispense water and the mixture of water and additive through the same outlet of the shower head (14), in particular through an outlet that generates a spray of droplets.

15. Dispenser according to one of the preceding claims, wherein the shower head (14) is configured to dispense a liquid, such as water or a water-based mixture, by generating impinging liquid jets.

16. A shower head, in particular for use in a dispenser according to the preceding claim, which is arranged to be connected to a shower hose and to at least one additive line, wherein an additive outlet arranged at the end of the additive line is arranged in the shower head.

17. Method for operating a dispenser for dispensing water with an additive according to one of claims 1 to 15, comprising the following steps for dispensing the additive (in the form of a mixture of additive and water):

-starting with an operating mode in which water is delivered to the shower head (14) and sprayed through the shower head (14);

reducing or stopping the delivery of water to the showerhead (14);

o e.g. by partially or completely closing the water valve (15) and/or reducing the delivery rate of the water pump (12) or stopping the water pump (12);

-delivering additive to the spray header (14) through the additive line (16) while reducing or stopping the delivery of water;

-restarting delivery of water to the shower head (14) or increasing the delivery rate to the same rate as or a different rate than before the reduction or stopping.

18. The method of claim 17, comprising the steps of:

-restarting the water delivery only for a short time called "mixture delivery time" and stopping the delivery of water to the shower head (14) after said "mixture delivery time".

19. The method of claim 18, comprising the steps of:

-operating the water pump (12) to deliver a quantity of water corresponding to the volume of a portion of additive delivered by the additive pump (9) during the "mixture delivery time", so as to obtain a controlled concentration of additive in the water during the delivery of the mixture.

20. A dispenser, particularly for use in a shower, arranged for dispensing water with an additive, comprising:

-at least one additive supply source (21);

-at least one additive line (16) for supplying additive from the at least one additive supply source (21) to a spray hose (13) for supplying water to a spray head (14);

it is characterized in that the preparation method is characterized in that,

-the dispenser comprises at least one additive pump (9) for supplying additive from the at least one additive supply source (21) to the at least one additive line (16),

the additive pump (9) is arranged and controlled in such a way that the delivery of additive to the spray hose (13) is controlled.

21. A dispenser according to claim 20, wherein an additive outlet (20) arranged at the end of the additive line (16) is arranged in the mixing unit.

22. The dispenser of claim 21, wherein at the additive outlet (20), the additive line (16) opens into a space within the mixing unit for directing water to the outlet of the mixing unit.

23. A dispenser according to claim 21, wherein the additive outlet (20) comprises a non-return valve (11).

24. The dispenser according to claim 23, wherein the check valve (11) is designed to open only if the pressure difference across the check valve (11) exceeds a threshold value.

25. Dispenser according to one of claims 20 to 24, wherein the additive pump (9) is a volumetric pump, in particular a peristaltic pump.

26. The dispenser of one of claims 20 to 25, wherein the water pump (12) is designed to deliver a flow of water through the shower head (14) at a rate of less than 5 liters/minute or less than 4 liters/minute or less than 3 liters/minute or less than 2 liters/minute.

27. Dispenser according to one of claims 20 to 26, wherein the inner diameter of the additive line (16) is between 1 mm and 4 mm, in particular at least about 2 mm.

28. A dispenser according to any one of claims 20 to 27, comprising more than two additive lines (16), each additive line having an associated additive supply (21) and optionally an associated additive pump (9).

29. The dispenser of one of claims 20 to 28, configured to store at least one set of dispensing parameters that explicitly specifies one or more additives and to determine a set of dispensing parameters to be used in operation of the dispenser by:

selecting one of said sets of allocation parameters and/or

Modifying a set of stored allocation parameters and/or

Receiving a stored set of allocation parameters from another device

And based on at least one of the following information:

information identifying an operator of the dispenser;

information identifying the person or object to be treated with the dispenser;

30. Dispenser according to one of the claims 20 to 29, wherein the water pump (12) is designed to generate a pressure of at least 4 bar, at least 5 bar, at least 6 bar, at least 7 bar or at least 8 bar.

31. Method for operating a dispenser for dispensing water with an additive, preferably according to one of claims 20 to 30, comprising the following steps for dispensing the additive (in the form of a mixture of additive and water):

starting in an operating mode in which water is conveyed to the mixing unit and optionally from the mixing unit to the spray hose (13) and the spray header (14) for spraying by means of the spray header (14);

reducing or stopping the delivery of the individual water to the mixing unit;

-delivering an additive to the mixing unit through the additive line (16) while reducing or stopping the delivery of water;

restart delivery of water to the mixing unit or increase the delivery rate to the same rate as or a different rate than before the reduction or stop.

32. The method of claim 31, comprising the steps of:

the delivery of water is restarted only for a brief time called "mixture delivery time" and stopped after said "mixture delivery time" to said mixing unit.

33. The method of claim 32, comprising the steps of:

34. A method according to claim 12 or 29, wherein a set of dispensing parameters comprises parameters specifying for one or more additives the amount of additive and the duration of additive dispensing, whereby the set of dispensing parameters specifies a trajectory of time-varying amounts for one or more additives.

35. Method according to claim 17 or 31, wherein the delivery of the additive is done by delivering a preset amount, in particular a portion, of the additive.

36. Method according to claim 35, wherein the delivery of the additive is performed by repeatedly delivering a preset amount of the additive in subsequent time intervals, in particular wherein the length of the intervals is determined in accordance with the dispensing parameter, and in particular wherein the dispensing parameter is determined in accordance with claim 12.

37. Dispenser according to one of claims 21 to 28, wherein the mixing unit is a static mixer comprising elements for generating turbulence in the mixed flow of water and additive, in particular by incorporating elements for generating turbulence into the flow of the line.