WO2021175752A1

WO2021175752A1 - Mixing and spray generating unit and pumping unit

Info

Publication number: WO2021175752A1
Application number: PCT/EP2021/054969
Authority: WO
Inventors: Vincent Vaucher
Original assignee: Smixin Sa
Priority date: 2020-03-04
Filing date: 2021-03-01
Publication date: 2021-09-10

Abstract

A mixing and spray generating unit, for mixing a liquid (6) with air and with an additive, in particular for a sanitary installation, generates a spray (5) of the liquid that carries air with it, and adds the additive to the spray (5) of the liquid. A pumping unit (60) for delivering the liquid and the additive comprises a reciprocating actuator (40) powered by the flow of the liquid to be dispensed and driving a reciprocating pump (50) to deliver the additive.

Description

MIXING AND SPRAY GENERATING UNIT AND PUMPING UNIT

The invention relates to the field of mixing a liquid with air and with an additive, and for dispensing them, in particular in a sanitary installation. It relates to a mixing and spray generating unit, and a pumping unit as described in the preamble of the corresponding independent claims.

EP 3 447 200 A1 discloses a spray shaper arranged to generate a spray of spray droplets, and a jet shaper for shaping from a liquid a jet consisting of multiple subjets of the liquid. A spray shaper can be part of a jet shaper. More precisely, a spray shaper in a jet shaper is a part of a spray former. The spray former comprises a spray shaper and a flight chamber. A spray former without a flight chamber can be regarded as a device comprising a spray shaper or even as being a spray shaper. The spray shaper operates by a) inducing a rotational movement of the liquid around one swirling axis of the spray shaper and with an inclination angle of 30 degrees or less relative to the swirling axis of the spray shaper, and b) the rotational movement of the liquid generating a spray cone wherein a cone axis of the spray cone is parallel to the swirling axis of the spray shaper. The rotational movement is present as long as the liquid is inside a channel of the spray shaper. Once the liquid, or its droplets, respectively, has left the channel, it flies inside the flight chamber, and the droplets follow an essentially straight path. It is an object of the invention, according to a first aspect, to create a mixing and spray generating unit of the type mentioned initially, which allows for an effective mixing of an additive to the liquid. It can be an object corresponding to this aspect to create a mixing and spray generating unit that allows to create a stream combining a liquid, a gas (in particular air) and an additive.

At least one of these objects is achieved at least in part by a mixing and spray generating unit according to the corresponding claims.

It is an object of the invention, according to a second aspect, to create a pumping unit that is suitable for providing an additive to such a mixing and spray generating unit. It can be an object corresponding to this aspect to create a pumping unit that delivers the additive with a precisely defined ratio relative to the liquid. It can be an object corresponding to this aspect to create a pumping unit that requires little maintenance. It can be an object corresponding to this aspect to create a pumping unit that does not require an extraneous power source.

At least one of these objects is achieved at least in part by pumping unit according to the corresponding claims. The mixing and spray generating unit, according to the first aspect, serves for mixing a liquid with air and with an additive. It comprises a spray former, wherein the spray former is arranged to generate from the liquid a spray of the liquid in a shape of a spray cone, and the spray former comprises a spray former outlet and a flight chamber, the spray former outlet being arranged as an exit point for the spray being generated, and the flight chamber being arranged to allow droplets of the spray to follow a flight path from the spray former outlet in an essentially straight line, and further comprises an additive inlet, at least one additive dispensing element in liquid communication with the additive inlet, the additive dispensing element being arranged to dispense the additive to the spray of the liquid. The liquid is for example water. The liquid is in another example a solution based on water. The liquid can be an emulsion containing water.

Optionally, the mixing and spray generating unit is used exclusively in sanitary fitting. Especially in faucets, for example in faucets for hand washing.

The mixing and spray generating unit can be used for different applications. Applications can be for example hand washing, hair care, personal hygiene, food (vegetables/fruits) cleaning, dish cleaning and/or cleaning respectively washing of other objects.

Typically, the spray is generated under ambient conditions.

In embodiments, a spray distributor is present, the spray distributor being arranged to shape from the spray of the liquid the jet of the liquid, the jet of the liquid consisting of multiple subjets of the liquid being free of mutual overlap.

The additive dispensing element adds the additive to the spray of the liquid after the spray of the liquid is formed by the spray former. If a spray distributor is present, then the additive is added to the spray of the liquid before the spray is formed by the spray distributor. If no spray distributor is present, the additive is added to the spray of liquid and is dispersed by the spray, without further guiding of the spray by the spray distributor, or with further guiding of the spray by another kind of guiding body different from the spray distributor.

In embodiments, the mixing and spray generating unit comprises a droplet size limiter through which the spray of the liquid passes and wherein the additive dispensing element is arranged to dispense the additive to the spray of the liquid before it passes through the droplet size limiter.

This allows to homogenise the combined flow of liquid and additive. It further allows to capture air in the spray of liquid. Typically, before the droplet size limiter, the air surrounds the liquid, after the droplet size limiter, the air is trapped in the stream of liquid. This effect can be enhanced by the presence of the additive, the additive being a surfactant.

In embodiments, an open area of the droplet size limiter is more than 60% of the total area of the droplet size limiter, and a distance between bars or wires constituting the mesh is between 0.5 and 1 millimetres. In embodiments, the open area is more than 70% and the distance is between 0.6 and 0.8 millimetres. In embodiments, the open area is between 70% and 80% and the distance is between 0.6 and 0.7 millimetres.

In embodiments, the additive dispensing element is arranged to dispense the additive to the spray of the liquid at two or more different locations along the outer circumference of the spray of the liquid.

This allows to evenly distribute the additive around the spray in the circumferential direction. In embodiments, when a spray distributor is present, the number of additive dispensing elements and their arrangement along the circumference can be identical to that of subjet duct exits of the spray distributor.

In embodiments, the mixing and spray generating unit comprises, as additive dispensing elements, two or more valves, in particular duck-bill valves, arranged to dispense the additive at the outer circumference of the spray of the liquid.

The valves typically are check valves. The presence of valves allows to precisely control the flow of additive. Check valves allow to control the flow of additive by controlling a pressure of the additive. The pressure in turn can be controlled by an additive pump.

In other embodiments, no valves are present and the additive is kept from flowing out of additive dispensing elements by the surface tension of the additive. Here too, the flow of the additive can be controlled via an additive pump.

In embodiments, the mixing and spray generating unit comprises, as additive dispensing elements, an annular valve unit, comprising one or more annular (ring- shaped) elements arranged around the circumference of the flight chamber defining one or more openings through which to dispense the additive at the outer circumference of the spray of the liquid.

This allows for an even more homogeneous distribution of the additive along the circumference, and also for a simple construction.

In embodiments, the spray former generates the spray cone in the form of a hollow cone. This allows to distribute the spray towards an annular droplet size limiter or an annular outlet without colliding with objects in the centre of such an outlet, which would cause the spray to lose energy. In embodiments, the spray former outlet comprises an annular outlet opening.

This allows to create a regular, homogeneous spray in the form of a hollow cone.

In embodiments, an air inlet is arranged to supply air to the spray of the liquid from the inside of the hollow spray cone.

This allows to feed air to the liquid without any additional conduit, and without a need for orienting such a conduit (arranged at the side of the mixing and spray generating unit) when mounting the mixing and spray generating unit.

In embodiments, a cone axis of the spray cone and an air entry direction are coaxial.

Such embodiments in which the air is supplied to the spray of the liquid from the hollow spray cone can also be realised without the admixing of an additive, thus as spray generating units (without mixing).

In embodiments, the air inlet is arranged to supply air to the spray of the liquid before the spray meets a region where the additive is dispensed to the liquid. This allows to improve the mixing of the additive and to create a homogeneous flow of the combined flow of liquid, air and additive.

The pumping unit for dispensing a liquid and an additive, in particular in a sanitary installation, comprises a positive displacement hydraulic actuator, a positive displacement pump, the actuator being arranged to drive the pump, the actuator being powered by the flow of the liquid to be dispensed, the pump being arranged to deliver the additive for dispensing the additive, the pump being a double action reciprocating pump.

In embodiments, the pumping unit for dispensing a liquid and an additive, in particular in a sanitary installation, comprises a reciprocating actuator, a reciprocating pump, the actuator being arranged to drive the reciprocating pump, the actuator being powered by the flow of the liquid to be dispensed, the pump being arranged to deliver the additive for dispensing the additive, the pump being a double action reciprocating pump.

This makes it possible to have the energy for pumping the additive provided by the flow of the liquid to dispensed. This in turn eliminates the need for an extraneous power source or for a power storage element such as a battery to power an additive pump. A comparatively small power source or storage can still be required for a controller of the pumping unit, and for controlling valves.

Here and in the remainder of this document, for the sake of brevity the term “reciprocating actuator” is generally denoted by “actuator”, and “reciprocating positive displacement pump” or “reciprocating pump” are generally denoted by “pump”.

In embodiments, the pumping unit is arranged to dispense the liquid used for driving the actuator in combination with the additive delivered by the pump, in particular as a mixture of the liquid with the additive. In embodiments, the entirety of the flow of the liquid to be dispensed flows through the actuator.

This makes it possible to deliver the additive, which typically is a fluid or liquid, with a precisely defined volume ratio relative to the liquid. The volume ratio is reproducible over time. Thus, a volume ratio between a volume of the liquid flowing through the actuator and dispensed by the pumping unit and a volume of the additive delivered is constant and is determined by the geometry of the actuator and the pump. The geometry or shape refers to the physical dimensions of volumes in which the fluids or liquids flow, and in particular to surface areas against which the fluids or liquids exert a force, displacing the surface (in the actuator) or being displaced by the surface (in the pump).

In embodiments, the actuator comprises a first control valve arranged to control a flow from a liquid inlet to a first supply conduit, the first supply conduit being in liquid communication with a first actuator volume, wherein an increase in the first actuator volume moves an actuator piston in a first direction and drives the pump in the first direction; a second control valve arranged to control a flow from the liquid inlet to a second supply conduit, the second supply conduit being in liquid communication with a second actuator volume, wherein an increase in the second actuator volume moves the actuator piston in a second direction opposite to the first direction and drives the pump in the second direction; an outlet unit for controlling a flow of the liquid from the first supply conduit and the second supply conduit to a liquid outlet for dispensing the liquid.

In embodiments, the actuator comprises an actuator cylinder, and the actuator piston is arranged to slide inside the actuator cylinder along a straight path. In other embodiments, the actuator piston follows a curved path. In embodiments, the actuator is configured to drive the pump in the first direction and supply the liquid to the liquid outlet through the second supply conduit by opening the first control valve and closing the second control valve, drive the pump in the second direction and supply the liquid to the liquid outlet through the first supply conduit by closing the first control valve and opening the second control valve, stop the pump and not to supply the liquid to the liquid outlet by closing both the first control valve and the second control valve, stop the pump and to supply the liquid to the liquid outlet through both the first supply conduit and the second supply conduit by opening both the first control valve and the second control valve.

In this way it is possible to set four operating states by controlling the two control valves. In the first two states, both the liquid and the additive are delivered. The states differ in the direction in which the pump moves. In the third state, nothing is delivered.

In the fourth state, only the liquid is delivered, but not the additive.

The first supply conduit and second supply conduit are in liquid communication with the outlet valve.

In embodiments, the outlet unit comprises an outlet valve configured to supply

• the liquid from the first supply conduit to the liquid outlet if its pressure is lower than the pressure of the second supply conduit;

• the liquid from the second supply conduit to the liquid outlet if its pressure is lower than the pressure of the first supply conduit;

• the liquid from both supply conduits or from one of both supply conduits to the liquid outlet if their pressure is equal.

In this manner, the outlet unit can be realised as a passive element. It is driven and controlled by the pressure difference in the conduits. In other embodiments, the outlet unit is an active element. For example, it comprises an outlet valve that is controlled by an additional power source, such as the power source required for the control unit and the two control valves. Generally, the pump can be operated for a wide range of liquid pressure values, typically mains pressure. For example, the range can be between 0.5 bar and 10 bar.

In embodiments, the pump is of the peristaltic type and comprises a hose and a roller arranged to pass along the length of the hose, compressing it and thereby creating a compressed hose section whose location along the hose is determined by the position of the actuator.

In embodiments, the hose is arranged inside or adjacent to an actuator cylinder in which an actuator piston of the actuator moves.

In embodiments, the roller is attached to and moved by the actuator piston inside the actuator cylinder.

In embodiments, the hose is arranged along a straight line. Typically, this is along the length of the actuator cylinder.

In embodiments, the pump comprises a pump cylinder with a first pump volume and a second pump volume separated by a pump piston, and wherein the pump piston is driven by the actuator.

In embodiments, the pump cylinder is arranged inside an actuator cylinder in which an actuator piston of the actuator moves.

In embodiments, the pump cylinder and the actuator cylinder are concentric. In embodiments, the pump piston is driven by the actuator by means of an actuator side magnet arrangement arranged on an actuator piston exerting a driving force on a pump side magnet arrangement arranged on the pump piston. In embodiments, the actuator side magnet arrangement comprises a first and a second group of actuator side magnets, the two groups being distanced from another in the direction of the longitudinal axis of the actuator, with a distance that is longer than that of the pump side magnet arrangement. In embodiments, the first and a second group of actuator side magnets are oriented to repel the respective end of the pump side magnet arrangement that is nearer to it. This can reduce friction between the pump side magnet arrangement and the inner wall of the pump cylinder. This in turn can allow for the use of labyrinth seals between the pump piston and the pump cylinder.

The pumping unit can operate as a dosing device delivering a combination of the liquid and the additive with a defined volume ratio between the two. The quantity being delivered can be controlled by operating the control valves.

In embodiments, the volume ratio of the volume of liquid driving the reciprocating actuator divided by the volume ratio of additive delivered by the pump for the same movement of the actuator is between ten and ten thousand.

Generally, this ratio is the same as an area ratio obtained by dividing the cross-section area of the actuator piston by the cross-section area of the pump. Depending on the application, the ratio can be in a particular range. For example:

• For mixing a typical fluid soap with water, a relative volume between 0.1% and 3% can be required, corresponding to a volume ratio or area ratio between TOOO and 33. • For mixing a concentrated fluid soap with water, a relative volume between 0.01% and 1% can be required, corresponding to a volume ratio or area ratio between 10Ό00 and 100.

• For mixing a disinfectant or chemical cleaning solution, a relative volume between 1% and 20% can be required, corresponding to a volume ratio or area ratio between 100 and 5.

• For special applications, the volume of the additive can be higher than that of the liquid, with the relative volume ratio or area ratio being equal to or lower than one.

In embodiments, in particular where a mixture of water and soap is dispensed, a flow rate of the liquid is in the range of 0.4 litres per minute to two litres per minute. In embodiments, a movement of the pistons along the length of the actuator cylinder takes between one and twenty seconds, in particular between two and ten seconds, in particular between two and four seconds. In embodiments, a cross section area of the actuator is between twenty and eight thousand square millimetres, in particular between eighty and two thousand square millimetres, in particular between one hundred and eight hundred square millimetres. In embodiments, a length along which the actuator piston travels is between three and thirty centimetres, in particular between five and twenty-five centimetres, in particular between eight and twenty-two centimetres.

In embodiments, the pumping unit is combined with a mixing and spray generating unit as described herein, wherein the liquid, in particular all the liquid, used for driving the pumping unit is supplied to and dispensed by the mixing and spray generating unit, and the additive delivered by the pump is delivered to the additive inlet of the mixing and spray generating unit.

Further embodiments are evident from the dependent patent claims. The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, which schematically show:

Figure 1 an embodiment of a jet shaper; Figure 2 a longitudinal section view of the same; Figure 3 a detail of the same, showing a spray in the shape of a hollow cone; Figure 4 a detail of the same, showing flows of air, liquid and additive; Figure 5 an embodiment with an annular additive dispensing element; Figures 6-7 a support ring and an elastic ring forming part of the annular dispensing element;

Figure 8 a pumping unit with a peristaltic pump, in a longitudinal section; Figure 9 the same in a transverse section; Figures 10-11 a pumping unit with magnetically coupled pistons, in orthogonal longitudinal sections;

Figures 12-13 the same, in different transverse sections; Figure 14 a detail of a longitudinal section of Figure 11; Figure 15 a pumping unit with control elements. The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.

Figure 1 shows an embodiment of a jet shaper 1, and Figure 2 a longitudinal section of the jet shaper 1. A direction of gravitation g runs from a top of figure 1 (i.e. a top edge of the drawing plane of figure 1) to a bottom of figure 1 (i.e. a bottom edge of the drawing plane of figure 1). The jet shaper 1 comprises a spray former 2, arranged in a top section of the jet shaper 1 and a spray distributor 3, arranged in a bottom section of the jet shaper 1. A liquid 6 enters the jet shaper 1 in a liquid entry direction 22 which, as a rule, is essentially parallel or at an angle between 5° and 15° to the direction of gravity g.

The liquid 6 enters the spray former 2 and a guiding element 14a arranged in the spray former 2. The guiding element 14a generates a rotational movement of the liquid 6 around a swirling axis or vortex axis 21. Due to the rotational movement of the liquid 6, the liquid 6 is dispersed into droplets of a spray at a spray former outlet 11. The droplets of spray form a spray cone 5 with an opening angle a and a cone axis 20. Figure 3 shows a detail of Figure 2, with elements omitted in order to better show the hollow spray cone 5 and an additive flow 76. The cone axis 20 is in this embodiment coincident with the swirling axis or vortex axis 21. The spray cone 5 is free of contact with a flight chamber 10 which comprises the spray cone 5. An air inlet 15 provides air to the flight chamber 10. The droplets in the spray cone 5 follow a straight flight path from the spray former outlet through the flight chamber 10 towards the spray distributor s.

Within the flight chamber 10, the liquid 6 in the spray cone 5 draws air from the air inlet 15. The liquid 6 in the spray combines with the air to form an aerated stream of liquid 6. This stream flows through a droplet size limiter 16 before entering the spray distributor 3. The droplet size limiter 16 can be a mesh.

In the spray distributor 3, spray distributor ducts 12 in the shape of a narrowing cone deflect and collect the droplets from the spray cone 5 into subjets 4. The subjets 4 leave the spray distributor 3 through subjet duct exits 13 in a subjet exit direction 23. The subjet exit direction 23 is essentially parallel to the liquid entry direction 22, and the subjets are arranged in a circular pattern.

Typically, about thirty to forty percent of the mixture passing through and exiting the spray distributor 3 is air. An operating pressure at which the liquid 6 enters the jet shaper 1 can be as low as one bar, or even as low as 0.4 bar. The operating pressure can be lower than 2 bar, lower than 1 bar, or lower than 0.5 bar.

By incorporating elements for supplying an additive to the stream of liquid 6 and air in the region of the spray cone 5, a mixing and spray generating unit 70 is formed. The mixing and spray generating unit can be incorporated in, or part of, a piece of furniture or a sanitary device.

These elements comprise an additive inlet 71 for supplying an additive to the spray, and an additive channel 74 running along the circumference of the spray former 2 for distributing the additive to additive dispensing elements 75. The additive dispensing element 75 are shown to be a number of separate, discrete elements, which can be duck bill valves. These elements are arranged to dispense the additive at discrete, separate locations along the inner circumference of the flight chamber 10.

Figure 4 shows a corresponding detail of Figure 2, with the flow of air through the air inlet 15, of the liquid from the spray former outlet 11 and the additive flow 76. For reasons of clarity, only part of the spray cone 5 is shown. Figures 5 through 7 show an embodiment in which the additive dispensing element 75 is realised as a ring-like dispenser or annular valve unit 77, 78, arranged to dispense the additive essentially along a continuous line along the inner circumference of the flight chamber 10. The annular valve unit comprises a support ring 77 and an elastic ring 78, shown in Figures 6 and 7 in a respective top view and sectional view. The support ring 77 surrounds and supports the elastic ring 78, with a annular distribution chamber 79 arranged between them. The distribution chamber 79 is fdled with additive, and when under pressure, the additive can force open a lower lip region 78a of the elastic ring 78 and flow out of the resulting opening. The opening is essentially annular. The support ring 77 can comprise regions with a larger inner diameter 77a. If this is the case, then the additive will first begin to flow out through these regions. This can assist in a regular distribution of the additive along the circumference of the spray cone 5.

The additive dispensing elements 75 - distributed in a continuous or discrete manner along the circumference - create an additive flow 76 into the spray cone 5. By joining the stream of liquid 6 and air in the region of the spray cone 5, the additive can be finely dispersed in this stream and mixed with this stream.

The combined spray of air, liquid and additive can be guided through the droplet size limiter 16 and the spray distributor 3, as in the embodiments of Figures 1 through 4.

In other embodiments, the mixing and spray generating unit 70 can be implemented without the spray distributor 3. In this case it generates a spray incorporating the additive, without further guiding of the spray by the spray distributor 3, or with further guiding of the spray by another kind of guiding body different from the spray distributor 3.

In order to provide the additive to the jet shaper 1 , a pumping unit 60 can be provided in which the flow of the liquid 6 is used to drive the pumping unit 60 and thereby the flow of the additive. The pumping unit 60 can comprise a plunger pump or a peristaltic pump or a combination of these pump types. A pump can usually be operated in two ways: when driven by an actuator, it can be operated as a pump, to pump a fluid. When supplied with a fluid under pressure, it can be operated as an actuator, driving the movement of a mechanical element.

A plunger pump comprises a cylinder with a reciprocating plunger or piston in it. In the liquid communication with the cylinder, suction and discharge or delivery valves are arranged. In a suction stroke the plunger retracts and the suction valves opens causing suction of fluid into the cylinder. In the forward stroke the plunger pushes the fluid out through the delivery valve. In a double acting reciprocating pump, a fluid acts on both sides of a piston moving inside a cylinder. Correspondingly, two suction pipes and two delivery conduits are required for a double acting pump. When there is a suction stroke on one side of the piston, at the same time there is a delivery stroke on the other side of the piston.

A peristaltic pump, also known as roller pump or tubing pump, is based on alternating compression and relaxation of a hose or tube, thereby drawing the contents into the hose or tube or pushing it out. A shoe or roller passes along the length of the hose or tube totally compressing it and creating a seal between the suction side and the discharge side of the pump, eliminating leakage between the two sides. The medium to be pumped does not come into contact with any moving parts and is totally contained within a robust, heavy-duty hose or a precision extruded tube.

Peristaltic pump typically are of a rotary type. Therein, a rotor with a number of "rollers", "shoes", "wipers", or "lobes" attached to the external circumference of the rotor compresses the flexible tube. As the rotor turns, the part of the tube under compression is pinched closed (or "occludes") thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state after the passing of the cam ("restitution" or "resilience") fluid flow is induced to the pump.

Figures 8 and 9 show a pumping unit with a peristaltic pump 50 driven by an actuator 40. The pump 50 comprises a hose 54 which is locally compressed at a compressed hose section 55, which separates a first pump volume 56a and a second pump volume 56b. The compressed hose section 55 is created by roller 45a arranged to move along the hose 54. The roller 45a is driven by an actuator piston 45 arranged to move in an actuator cylinder 44. The actuator cylinder 44 and actuator piston 45 define a double acting reciprocating pump that is operated as an actuator 40 driving the roller 45a. The actuator piston 45 separates a first actuator volume 46a and second actuator volume 46b inside the actuator cylinder 44. For this, a gasket 45c can be arranged between the actuator piston 45 and an inner wall of the actuator cylinder 44. A position sensor magnet 45b can be arranged to move with the actuator piston 45, and sensors or switches 98 can be arranged at different locations along the length of the actuator cylinder 44 in order to determine the position of the actuator piston 45. The hose 54 is arranged inside the actuator cylinder 44, thereby simplifying the construction of the elements that transfer the driving force from the actuator 40 to the pump 50 while ensuring impermeability.

Figures 10 to 14 show a pumping unit with magnetically coupled pistons, in different sections. As in the previous embodiment, the actuator piston 45 is arranged to move in the actuator cylinder 44, constituting a double acting reciprocating pump that is operated as an actuator 40. Within the actuator cylinder 44, a pump cylinder 64 is arranged, with a pump piston 65 arranged inside the pump cylinder 64 and separating the pump cylinder 64 into a first pump volume 56a and second pump volume 56b. The actuator piston 45 carries an actuator side magnet arrangement 45 which is arranged to interact with the pump piston 65. The pump piston 65 can be ferromagnetic or comprise one or more permanent magnets. The interaction of the actuator piston 45 and the pump piston 65 causes the pump piston 65 to move along the length of the pump cylinder 64 following the movement of the actuator piston 45. In the embodiment shown, the pump cylinder 64 is arranged coaxially with the actuator cylinder 44. In other embodiments, not illustrated, it can be arranged eccentrically or even adjacent to a side wall of the actuator cylinder 44.

Figure 12 shows a transverse section of the pumping unit 60 in the region comprising the actuator piston 45, and Figure 13 in the region of an end section of the pumping unit 60, with a first suction conduit 52a and first suction valve 53a leading to the first pump volume 56a, and a first delivery valve 57a and 59 a leading away from the first pump volume 56a. The valves are shown, by way of example, to be duck bill valves. Below these valves, Figure 13 also shows valves leading to and away from the first actuator volume 46a. These valves are not strictly necessary for operation of the actuator. Figure 14 shows a longitudinal section in the region of the opposite end section, with a second suction conduit 52b and second suction valve 53b leading to the second pump volume 56b, and a second delivery valve 57b and second delivery conduit 59b leading away from the second pump volume 56b.

The pumping units 60 according to the embodiments of Figures 8 through 14 can be operated in combination with a jet shaper 1 as described herein, or with another type of dispenser in which a flow of liquid 6 is combined with a flow of an additive. For this, the actuator 40 is arranged to be driven by the flow of the liquid 6, and the pump 50 is arranged to pump the additive.

Since the liquid 6 driving the pumping unit 60 is the same that is to be dispensed, the proportion of the volume of liquid 6 and the volume of additive being delivered should be in a range determined by the application of the pumping unit 60. The proportion is determined by the volume ratio of liquid displaced in the actuator 40 and the pump 50 for the same movement of the actuator piston 45. This normally is the same as the relative size of the cross-sectional areas of the volumes of the actuator 40 and the pump 50. In embodiments, this relative size lies between ten and ten thousand. In this context it is desirable to have different operating conditions of the pumping unit 60, that is:

• a first operating mode in which neither liquid 6 nor additive are delivered;

• a second operating mode in which only liquid 6 is delivered;

• a third operating mode in which both liquid 6 and additive are delivered, and the actuator piston 45 moves in a first direction;

• a fourth operating mode in which both liquid 6 and additive are delivered, and the actuator piston 45 moves in a second direction, opposite to the first direction. It is possible to switch between these four operating modes with only two active valves controlling the flow of the liquid 6 and the movement of the actuator piston 45 and thereby the delivery of the additive in combination with the liquid 6. In an embodiment, this is accomplished with the configuration of Figure 15. It can be implemented for the pumping units 60 shown above, or for other pumping units in which a double acting reciprocating pump is operated as an actuator. For clarity, Figure 15 shows only the actuator 40 part, and it is understood that movement of the actuator piston 45 is coupled to movement of a pump 50 for the additive.

In addition to the elements of the actuator 40 already presented, a liquid inlet 41 for the liquid 6 is shown, from which a first supply conduit 43a leads, via a first control valve 42a to the first actuator volume 46a and an outlet unit 47, and a second supply conduit 43b leads, via a second control valve 42b, to the second actuator volume 46b and the outlet unit 47. From the outlet unit 47, the combined flow from the first supply conduit 43a and second supply conduit 43b flows to a liquid outlet 49. In the context of a mixing unit, the liquid outlet 49 can deliver the liquid 6 to the mixing unit for mixing it with the additive. The outlet unit 47 can implement a hydraulic logic function with two inputs and one output, in which the flow from the input having the higher pressure is blocked and the fluid from the input with the lower pressure flows to the output. If the pressure is the same at both inputs, the fluid from both flows to the output. With this logic function, the four operating conditions presented above can be implemented in the following manner:

• first operating mode: both control valves 42a, 42b are closed. The actuator piston 45 does not move, thus no additive is delivered by the pump 50.

• second operating mode: both control valves 42a, 42b are opened. The pressure in the first actuator volume 46a and second actuator volume 46b is the same. Thus, the actuator piston 45 does not move, thus no additive is delivered. The liquid 6 from both supply conduits 43a, 43b exits the liquid outlet 49.

• third operating mode: the first control valve 42a is opened and the second control valve 42b is closed. o The higher pressure in the first supply conduit 43a drives the actuator piston 45 in the first direction (to the right in Figure 15), causing the pump 50 to deliver the additive. o The higher pressure in the first supply conduit 43a also forces the outlet unit 47 to close the input from the first supply conduit 43a and open the input from the second supply conduit 43b, causing the liquid 6 to be delivered to the liquid outlet 49.

• fourth operating mode: as in the third operating mode, but with the roles of the first and second side reversed. Sensors 98 are arranged to detect at least an end position of the actuator piston 45, and a controller 99 is arranged to control the control valves, based on readings from the sensors, and on an input specifying a required operating mode.

The hydraulic logic function described above can be implemented, for example, with a dual poppet outlet valve 47a. A dual poppet valve comprises two valve seats and one poppet. The poppet comprises two plugs at opposite ends of a valve shaft or valve stem, and thus is called a double poppet 48. Each plug is arranged to close one the two valve seats, with one the valves being closed while the other is open, and vice versa. The position of the double poppet 48 shown in Figure 15 corresponds to the fourth operating mode, with the second supply conduit 43b being at a higher pressure than the first supply conduit 43a. This constitutes a passive outlet valve. In other embodiments, the outlet is actively controlled by the controller 99. While the invention has been described in present embodiments, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.

Claims

P A T E N T C L A I M S

1. A mixing and spray generating unit (70), for mixing a liquid with air and with an additive, comprising a spray former (2), wherein the spray former (2) is arranged to generate from the liquid (6) a spray of the liquid (6) in a shape of a spray cone (5) and the spray former (2) comprises a spray former outlet (11) and a flight chamber (10), the spray former outlet (11) being arranged as an exit point for the spray being generated, and the flight chamber (10) being arranged to allow droplets of the spray to follow a flight path from the spray former outlet (11) in an essentially straight line; an additive inlet (71), at least one additive dispensing element (75) in liquid communication with the additive inlet (71), the additive dispensing element (75) being arranged to dispense the additive to the spray of the liquid (6).

2. The mixing and spray generating unit (70) of claim 1, comprising a droplet size limiter (16) through which the spray of the liquid (6) passes and wherein the additive dispensing element (75) is arranged to dispense the additive to the spray of the liquid (6) before it passes through the droplet size limiter (16).

3. The mixing and spray generating unit (70) of one of the preceding claims, wherein the additive dispensing element (75) is arranged to dispense the additive to the spray of the liquid (6) at two or more different locations along the outer circumference of the spray of the liquid (6).

4. The mixing and spray generating unit (70) of claim 3, comprising, as additive dispensing elements (75), two or more separate valves, in particular duck-bill valves, arranged to dispense the additive at the outer circumference of the spray of the liquid (6).

5. The mixing and spray generating unit (70) of claim 3, comprising, as additive dispensing elements (75), an annular valve unit (77, 78), comprising one or more annular elements arranged around the circumference of the flight chamber (10) defining one or more openings through which to dispense the additive at the outer circumference of the spray of the liquid (6).

6. The mixing and spray generating unit (70) of one of the preceding claims wherein the spray former (2) generates the spray cone (5) in the form of a hollow cone.

7. The mixing and spray generating unit (70) of claim 6, wherein the spray former outlet (11) comprises an annular outlet opening.

8. The mixing and spray generating unit (70) of one claim 6 or 7, wherein an air inlet (15) is arranged to supply air to the spray of the liquid (6) from the inside of the hollow spray cone (5).

9. The mixing and spray generating unit (70) of claim 8 wherein the air inlet (15) is arranged to supply air to the spray of the liquid (6) before the spray meets a region where the additive is dispensed to the liquid (6).

10. A pumping unit (60) for dispensing a liquid and an additive, in particular in a sanitary installation, comprising a positive displacement hydraulic actuator (40), a positive displacement pump (50), the actuator (40) being arranged to drive the pump (50), the actuator (40) being powered by the flow of the liquid to be dispensed, the pump (50) being arranged to deliver the additive for dispensing the additive.

11. A pumping unit (60) according to claim 10, for dispensing a liquid and an additive, in particular in a sanitary installation, comprising a reciprocating actuator (40), a reciprocating pump (50), the actuator (40) being arranged to drive the reciprocating pump (50), the actuator (40) being powered by the flow of the liquid to be dispensed, the pump (50) being arranged to deliver the additive for dispensing the additive, the pump (50) being a double action reciprocating pump.

12. The pumping unit (60) of claim 10 or 11, arranged to dispense the liquid used for driving the actuator (40) in combination with the additive delivered by the pump (50), in particular as a mixture of the liquid with the additive.

13. The pumping unit (60) of one of claims 10 to 12, wherein the entirety of the flow of the liquid to be dispensed flows through the actuator.

14. The pumping unit (60) of one of claims 10 to 13, wherein a volume ratio between a volume of the liquid flowing through the actuator and dispensed by the pumping unit and a volume of the additive delivered is constant and is determined by the geometry of the actuator and the pump.

15. The pumping unit (60) of one of claims 11 to 14 wherein the actuator (40) comprises a first control valve (42a) arranged to control a flow from a liquid inlet (41) to a first supply conduit (43a), the first supply conduit (43a) being in liquid communication with a first actuator volume (46a), wherein an increase in the first actuator volume (46a) moves an actuator piston (45) in a first direction and drives the pump (50) in the first direction; a second control valve (42b) arranged to control a flow from the liquid inlet (41) to a second supply conduit (43b), the second supply conduit (43b) being in liquid communication with a second actuator volume (46b), wherein an increase in the second actuator volume (46b) moves the actuator piston (45) in a second direction opposite to the first direction and drives the pump (50) in the second direction; an outlet unit (47) for controlling a flow of the liquid from the first supply conduit (43a) and the second supply conduit (43b) to a liquid outlet (49) for dispensing the liquid.

16. The pumping unit (60) of claim 15 wherein the actuator (40) is configured to drive the pump (50) in the first direction and supply the liquid to the liquid outlet (49) through the second supply conduit (43b) by opening the first control valve (42a) and closing the second control valve (42b), drive the pump (50) in the second direction and supply the liquid to the liquid outlet (49) through the first supply conduit (43a) by closing the first control valve

(42a) and opening the second control valve (42b), stop the pump (50) and not to supply the liquid to the liquid outlet (49) by closing both the first control valve (42a) and the second control valve (42b), stop the pump (50) and to supply the liquid to the liquid outlet (49) through both the first supply conduit (43a) and the second supply conduit (43b) by opening both the first control valve (42a) and the second control valve (42b).

17. The pumping unit (60) of claim 16 wherein the outlet unit (47) comprises an outlet valve (47a) configured to supply · the liquid from the first supply conduit (43a) to the liquid outlet (49) if its pressure is lower than the pressure of the second supply conduit (43b); • the liquid from the second supply conduit (43b) to the liquid outlet (49) if its pressure is lower than the pressure of the first supply conduit (43a); • the liquid from both supply conduits (43a, 43b) or from one of both supply conduits (43a, 43b) to the liquid outlet (49) if their pressure is equal.

18. The pumping unit (60) of one of claims 10 to 17 wherein the pump (50) is of the peristaltic type and comprises a hose (54) and a roller (45a) arranged to pass along the length of the hose (54), compressing it and thereby creating a compressed hose section (55) whose location along the hose (54) is determined by the position of the actuator (40).

19. The pumping unit (60) of claim 18 wherein the hose (54) is arranged inside or adjacent to an actuator cylinder (44) in which an actuator piston (45) of the actuator (40) moves.

20. The pumping unit (60) of claim 19 wherein the roller (45a) is attached to and moved by the actuator piston (45) inside the actuator cylinder (44).

21. The pumping unit (60) of one of claims 10 to 17 wherein the pump (50) comprises a pump cylinder (64) with a first pump volume (56a) and a second pump volume (56b) separated by a pump piston (65), and wherein the pump piston (65) is driven by the actuator (40).

22. The pumping unit (60) of claim 21 wherein the pump cylinder (64) is arranged inside an actuator cylinder (44) in which an actuator piston (45) of the actuator (40) moves.

23. The pumping unit (60) of claim 21 or 22 wherein the pump piston (65) is driven by the actuator (40) by means of an actuator side magnet arrangement (45e) arranged on an actuator piston (45) exerting a driving force on a pump side magnet arrangement (65a) arranged on the pump piston (65).

24. The pumping unit (60) of claim 23 wherein the actuator side magnet arrangement (45) comprises a first and a second group of actuator side magnets, the two groups being distanced from another in the direction of the longitudinal axis of the actuator (40), with a distance that is longer than that of the pump side magnet arrangement (65a), and wherein preferably the first and a second group of actuator side magnets are oriented to repel the respective end of the pump side magnet arrangement (65 a) that is nearer to it.

25. The pumping unit (60) of one of the claims 10 to 24, wherein the volume ratio of the volume of liquid driving the reciprocating actuator (40) divided by the volume ratio of additive delivered by the pump for the same movement of the actuator is between ten and ten thousand.

26. The pumping unit (60) of one of the claims 10 to 25 in combination with a mixing and spray generating (70) unit as in one of claims 1 to 9, wherein the liquid, in particular all the liquid, used for driving the pumping unit (60) is supplied to and dispensed by the mixing and spray generating unit (70), and the additive delivered by the pump (50) is delivered to the additive inlet (71) of the mixing and spray generating unit (70).