Dispensing device for purified water

Abstract

The present application relates to a dispensing device for purified water, and more particularly to a dispensing device for ultrapure water. The present application also relates to a water purification system comprising such a dispensing device for purified water, and to a method for dispensing purified water.

Description

TECHNICAL FIELD

[0001] The present application relates to dispensing devices for purified water, more particularly to dispensing devices for ultrapure water. The present application further relates to water purification systems comprising such dispensing devices for purified water, and to methods for dispensing purified water. BACKGROUND

[0002] Various applications in the pharmaceutical, life science or semiconductor field require water of higher purity than the purity of natural water or water from a tap ("tap water") in order to avoid or at least reduce the occurrence of unwanted side reactions or negative effects on the reproducibility in the analysis or production process by the introduction of contaminants. Thus, depending on the target application, the water purity has to be improved by at least partially removing contaminants contained in the water. Water of the highest purity, usually denoted as "ultrapure" or as "Type I" water according to ASTM D 1193-06, is characterized, for example, by a resistivity of at least 18.0 MΩ-cm and a total organic carbon (TOC) of at most 5 ppb. "Type II" water is usually characterized by a resistivity of at least 1.0 MΩ-cm and a total organic carbon of at most 50 ppb. "Type III" water is the lowest water quality grade for laboratory use, which has a resistivity of at least 0.05 MΩ-cm and a total organic carbon of at most 200 ppb, and is recommended for routine laboratory use, such as for glassware rinsing or heating baths and for feeding to water purification systems producing Type I water.

[0003] Water purification systems allowing the production of ultrapure or Type I water are known. A monolithic water purification system designed to purify water from tap water comprises various water purification steps, such as, for example, filtration, reverse osmosis, electrodeionization, ultraviolet radiation treatment, ion exchange steps. Generally, such purification systems comprise a first purification stage, in which tap water is purified to a first purity grade (e.g. Type II or lower grade as defined by ASTM D 1193-06), and a second purification stage, in which the pre-purified water from the first purification stage is further purified to a higher purity (e.g. Type I as defined by ASTM D 1193-06) which can then be dispensed and used from the system.

[0004] Purifying water to ultrapure levels is a challenge, as the levels of acceptable contaminants are very low. Therefore, in order to avoid the accumulation of contaminants in the water purification system and dispensing section, for example, when no water is dispensed from the system, the purified water needs to be continuously recirculated throughout the system, for example, by a continuous recirculation through the first purification stage and the second purification stage and through the dispensing device.

[0005] In many of the market available water purification systems, the dispenser for dispensing purified water from the system is mobile for user convenience, enabling the user to move it to the actual point of use within a given range, without having to displace the heavy water purification system as a whole. This necessitates a feed line in a first flow path to provide purified water from a previous purification stage to the dispensing device and in a second flow path to recycle the non-dispensed purified water back for recycling. Furthermore, since the dispensing device comprises an electromagnetic and / or electrically operated valve, a power cable to provide power to this / these valve(s) is also required. In order to avoid damaging the feed line and the power cable, they are often surrounded by a sheath for protection. As a result, the feed line becomes rather thick and heavy, resulting in reduced flexibility.

[0006] For example, Figure 1 A flow diagram of a water purification system (100) in the state of the art of market available water purification systems as disclosed in EP 1 814 007 A1 is shown in Fig.

[0007] In such market available state of the art water purification systems, the flow of purified water through the outlet of the dispenser is controlled substantially by opening and closing the outlet by means of an electromagnetic valve. However, electromagnetic valves only have an on-off setting and cannot control the flow of purified water to be dispensed. For this reason, the electromagnetic valve is sometimes coupled with an electrically operated valve, thereby allowing the user to precisely control the flow of dispensed water from drop-by-drop (or "drop-like") dispensing to high flow. Both the electromagnetic valve and the electrically operated valve can be integrated together in the dispenser, or alternatively, the electrically operated valve can be placed remotely, for example in a remote central unit, with only the electromagnetic valve in the actual dispenser.

[0008] For example, water purification systems and distribution systems for ultrapure water are also described in US 5,925,240 A; WO 2010 / 043899 A1 ; and US 11,035,484 B2.

[0009] However, existing water purification systems and in particular distribution systems and dispensing devices have many disadvantages, such as for example: (i) a PCB ("printed circuit board") with electronics has to be integrated in the dispensing unit, wherein power is transmitted from a remote main system to the dispenser or dispensing device; (ii) solenoid and motorized valves together are bulky components which limit the integration and design options of the dispenser in order to maintain an ergonomic operation; (iii) energizing the actuation coil of a solenoid valve for a long time causes heating which can impair the quality of the purified water dispensed from the dispenser or dispensing device; and (iv) in a system with more than one dispenser or dispensing device, a motorized valve coupled with several solenoid valves allows only one flow setting at a time and it is not possible to set different flows for different dispensers or dispensing devices.

[0010] There is therefore a need to overcome such and other drawbacks and to make water purification systems, in particular water purification systems for laboratory applications, and in particular dispensing devices, more user-friendly and / or simpler in terms of construction, preferably in combination with one or more of the factors of reducing size, cost and environmental impact.

[0011] In addition, such water purification systems preferably also allow an easy, ergonomic operation and / or easy and stable assembly. SUMMARY

[0012] The present inventors have now surprisingly found that the above needs can be met, individually or in any combination, by the dispensing device, water purification system and method of the present application.

[0013] The present application therefore provides a dispensing device for dispensing purified water, the dispensing device comprising (a) a dispenser comprising a valve assembly and a water outlet; and (b) a feed line providing purified water to the dispenser and removing water from the dispenser, wherein the feed line comprises a monolithic multi-lumen tubing comprising at least two separated lumens serving as flow paths for feeding water to and from the dispenser, respectively.

[0014] In addition, the present application provides a water purification system comprising such a dispensing device.

[0015] Furthermore, the present application provides a method of dispensing purified water, the method comprising the steps of (A) providing such a dispensing device as defined herein; (B) providing purified water to the dispenser by the feed line; and (C) dispensing purified water by the dispenser. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is EP 1 814 007 A1 Figure 1reproduction showing a schematic representation of an exemplary flow chart of an example water purification system available on the market.

[0017] Figure 2 showing a schematic representation of an example water purification system of the present application.

[0018] Figure 3a showing a schematic representation of an example monolithic multi-lumen tubing as can be used herein.

[0019] Figure 3b showing a schematic representation of an example monolithic multi-lumen tubing surrounded by a tight protective sheath. Figure 3a

[0020] Figure 3c showing a schematic representation of an example monolithic multi-lumen tubing surrounded by a loose protective sheath. Figure 3a

[0021] Figure 4 showing a perspective view of an example first disc of a valve assembly according to the present application.

[0022] Figure 5 showing a perspective view of an example second disc of a valve assembly according to the present application.

[0023] Figure 6 showing a schematic top view of an example valve assembly according to the present application, wherein a first disc as shown in Figure 4 and a second disc as shown in Figure 5 are overlaid on each other.

[0024] Figure 7 showing a schematic representation of an example dispenser of the present application.

[0025] Figure 8a showing a schematic cross-sectional view of an example dispenser according to the present application, wherein the valve assembly of the present application is in a closed position.

[0026] Figure 8b showing a schematic cross-sectional view of an example dispenser according to the present application, wherein the valve assembly of the present application is in an open position. DETAILED DESCRIPTION

[0027] For the purposes of the present application, the term "distribution system" is used to generally denote a system bringing purified water from a water purification unit to a point of use. Such a distribution system may, for example, comprise one or more selected from the group consisting of a distribution device, a dispensing unit, a feed line and / or a distributor, as defined herein.

[0028] ​​For the purposes of the present application, the terms "feed line" and "purified water feed line" are used consistently to denote a feed line that provides purified water to a dispenser and removes from the dispenser purified water that is not dispensed (i.e. not drawn off from the system for use) ("non-dispensed purified water").

[0029] For the purposes of the present application, the term "feed line" and "purified water feed line" are used consistently to denote a feed line that provides purified water to a dispenser and removes from the dispenser purified water that is not dispensed (i.e. not drawn off from the system for use) ("non-dispensed purified water").

[0030] For the purposes of the present application, the term "lumen" is used to denote a continuous cavity extending along a longitudinal axis of a tube. Throughout the present application, such a continuous cavity extending along a longitudinal axis of a tube can also be referred to as "flow path" or "channel".

[0031] The present application relates to a dispensing device for liquids, such as water, and in particular for dispensing purified water, e.g. ultra-pure (i.e. Type I) water. It has been found that the present dispensing device is particularly useful in water purification systems for laboratory applications. Such water purification systems for laboratory applications preferably have a dispensing rate ("maximum dispensing rate") of at most 5 l min -1 , more preferably at most 4 l min -1 , even more preferably at most 3 l min -1 and most preferably at most 2 l min -1 . Although generally described herein in the context of such water purification systems, the present dispensing device can also be used in other applications that can require precise dispensing of liquids.

[0032] Such a water purification system generally comprises a water feed, a water purification unit and a dispensing device, which in turn comprises a feed line and a dispenser. For reasons of clarity, it is noted that the feed line is (fluidically) connected to the water purification unit and the dispenser.

[0033] Figure 2 A schematic representation of such a water purification system (10) is shown in Fig. 1, which comprises a raw water feed line (11), a water purification unit (12) and a dispensing device (13), which in turn comprises a feed line (14) and a dispenser (15).

[0034] Devices for water purification and thus components generally comprised in a water purification unit to purify raw water from an external source to a desired level of purity are generally known in the art and are disclosed, for example, in the documents indicated.

[0035] Feed line The feed line (or purified water feed line) provides (or delivers) purified water to the dispenser and removes water that is not dispensed from the dispenser back to the water purification unit where it then undergoes one or more purification steps. Providing such flow to and from the dispenser ("circulation") avoids the accumulation of contaminants in water that is not flowing (e.g., by outgassing of contaminants from the material of the tubing used to direct the purified water). Such circulation can be performed continuously, or preferably discontinuously to reduce energy consumption, e.g., by regularly circulating for a period (or length of time) sufficient to remove and / or re-purify any water in the circuit (including the feed line) that is not flowing. The period of time from one such circulation to another (i.e., the time between circulations) can be determined, e.g., based on the amount of contaminants introduced into the purified water over a certain period of time and / or the level of purity of the purified water that is desired.

[0036] The present water feed line includes, or preferably consists of, a unitary multi-lumen tubing. Such unitary multi-lumen tubing includes at least two (e.g., two, or three, or four, or five, or six, or seven, or eight, or even more than eight) separate tube lumens in a single ("unitary") tubing, which are respectively used as flow paths to feed water to and from the dispenser. Note that regardless of the total number of tube lumens included in such unitary multi-lumen tubing, there is at least one (e.g., one, or two, or three, or four, or even more than four) tube lumen used as a flow path (or passageway) to provide (purified) water to the dispenser, and at least one (e.g., one, or two, or three, or four, or even more than four) tube lumen used as a flow path (or passageway) to remove non-dispensed purified water from the dispenser.

[0037] Preferably, the present unitary multi-lumen tubing includes at least one (e.g., one, or two, or three, or four, or even more than four) central tube lumen and at least one (e.g., one, or two, or three, or four, or even more than four) peripheral (or outer) tube lumen, wherein each tube lumen is separated from any other tube lumen.

[0038] Preferably, the present unitary multi-lumen tubing includes at least two (e.g., two, or three, or four, or five, or six, or seven, or eight, or even more than eight) tube lumens that are symmetrically distributed around at least one central tube lumen, wherein each tube lumen is separated from any other tube lumen.

[0039] Preferably, the present monolithic multi-lumen tubing comprises, or preferably consists of, a low-solubility material, preferably a low-solubility polymer. Such low-solubility polymers can for example be selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF, also known as polyvinylidene difluoride), perfluoroalkoxy polymer (PFA) and low-density polyethylene (LDPE), wherein low-density polyethylene is preferred.

[0040] Preferably, the present feed line comprises a protective sheath surrounding the monolithic multi-lumen tubing. Such a sheath can surround the monolithic multi-lumen tubing tightly (i.e. without any free space between the sheath and the outer surface of the monolithic multi-lumen tubing) or loosely (i.e. with a free space between the sheath and the outer surface of the monolithic multi-lumen tubing). Preferably, such a sheath surrounds the monolithic multi-lumen tightly, wherein the sheath and the monolithic multi-lumen tubing are co-extruded. Co-extrusion of the sheath and the monolithic multi-lumen tubing results in a solid adhesion between the two, essentially making it a monolithic sheathed multi-lumen tubing.

[0041] Preferably, the protective sheath comprises (preferably consists of) a material different from the material of the monolithic multi-lumen tubing.

[0042] Preferably, the present feed line, including the protective sheath if present, is flexible. Such a flexible feed line is then preferably made of low-density polyethylene. This will allow for easy handling and improved ergonomics of the dispensing device.

[0043] Figure 3a An exemplary monolithic multi-lumen tubing (20) that can be used herein is schematically shown, comprising a total of five lumens (21) separated from each other, wherein there is one central lumen (21a) and four peripheral lumens (21b) arranged symmetrically around the central lumen (21a).

[0044] Figure 3b An exemplary monolithic multi-lumen tubing (20) that can be used herein is schematically shown, comprising a total of five lumens (21) separated from each other, wherein there is one central lumen (21a) and four peripheral lumens (21b) arranged symmetrically around the central lumen (21a). Figure 3a An exemplary monolithic multi-lumen tubing (20) that can be used herein is schematically shown, comprising a total of five lumens (21) separated from each other, wherein there is one central lumen (21a) and four peripheral lumens (21b) arranged symmetrically around the central lumen (21a).

[0045] Figure 3c An exemplary monolithic multi-lumen tubing (20) that can be used herein is schematically shown, comprising a total of five lumens (21) separated from each other, wherein there is one central lumen (21a) and four peripheral lumens (21b) arranged symmetrically around the central lumen (21a). Figure 3a An exemplary monolithic multi-lumen tubing (20) that can be used herein is schematically shown, comprising a total of five lumens (21) separated from each other, wherein there is one central lumen (21a) and four peripheral lumens (21b) arranged symmetrically around the central lumen (21a).

[0046] Dispenser Although the present dispenser can comprise any suitable valve arrangement allowing the flow of purified water to be dispensed to be controlled from a maximum dispensing rate from dropwise up to the system, it is preferred that the dispenser comprises a valve assembly comprising two ceramic disc members (or a "pair" of disc members), which can hereinafter also be referred to as a "first disc member" and a "second disc member", respectively.

[0047] Preferably, the pair of first and second disc members are rotated relative to each other with mutually facing first and second sealing contact surfaces arranged in at least partial sliding contact with each other, wherein the first disc member has at least one window, wherein the second disc member has a solid portion arranged to fully cover and thus close the at least one window of the first disc member in a fully closed rotational position, and an open portion arranged to at least partially expose the at least one window of the first disc member in a fully open rotational position.

[0048] Preferably, the solid portion of the second disc member arranged to fully cover to close the at least one window of the first disc member in the fully closed rotational position is formed so as to comprise such a portion of the second sealing contact surface that overlaps the first sealing contact surface of the first disc member around the edge of the window with a sealing zone having a width of at least 1.5 mm (preferably at least 2.0 mm).

[0049] Preferably, the first and second sealing contact surfaces of the pair of first and second disc members arranged in at least partial sliding contact with each other have a surface roughness Ra of at most 0.60 pm, and / or a surface flatness of at most 0.80 pm, and are preferably polished or ground.

[0050] Preferably, the mutually facing first and second sealing contact surfaces of the pair of first and second disc members are arranged such that a percentage of 50% to 80% (preferably 55% to 75%, most preferably 60% to 70%) of the first and second sealing contact surfaces are in sliding contact with each other between the fully closed rotational position and the fully open rotational position.

[0051] Preferably, the second disc member is in free floating contact with the first disc member or biased towards the first disc member by a biasing member.

[0052] Preferably, the at least one window of the first disc member has a notch / indentation recessed into the material of the first disc member at an edge of the at least one window at a side where the at least one window starts to be exposed when the second disc member is moved in a direction towards the fully open rotational position from the fully closed rotational position, from a plane defined by the first sealing contact surface of the first disc member.

[0053] Preferably, the notch / dent has a pointed tip that gradually widens and / or deepens toward the at least one window.

[0054] Preferably, the at least one window has an inclination or slope at a sidewall adjacent to the side on which the at least one window begins to be exposed when the second disc moves from a fully closed rotational position toward a fully open rotational position, such that the free opening width of the at least one window gradually becomes narrower in the thickness direction of the first disc as the distance from the plane of the first sealing contact surface increases.

[0055] Preferably, the valve assembly is sized to allow for a range of rotational angles of relative movement between a fully closed and a fully open rotational position, from a droplet (preferably 20 ml∙min)... -1 Up to 5 l∙min -1 (More preferably up to 4 l∙min) -1 Or even more preferably up to 3 l∙min -1 And most preferably at most 2 l∙min -1 (This is done) through at least one window to provide traffic.

[0056] Preferably, the rotation angle between the fully closed rotation position and the fully open rotation position is in the range of 50° to 70°, more preferably 55° to 65°, and most preferably about 60°.

[0057] Preferably, the first disc is provided with a positioning notch for preventing rotation and defining the installation position in the receiving portion of the liquid dispenser, the positioning notch being formed and / or arranged asymmetrically around the circumference of the first disc.

[0058] Preferably, the second disc has one or more drive recesses and / or protrusions on the side opposite to the second sealing contact surface for engagement with the rotary actuator of the liquid dispenser.

[0059] Preferably, the first disc has a circular outer periphery, and the second disc has a non-circular outer periphery with an opening portion arranged to be radially recessed from the outer periphery to at least partially expose the at least one window of the first disc.

[0060] Preferably, the first disc and / or the second disc are made of ceramic material (preferably alumina ceramic).

[0061] Preferably, the first disc of the valve assembly is rotationally fixed in position within the housing such that the at least one window is in communication with the outlet, and the second disc is mounted in the housing so as to freely float in contact with the first disc, and such that the first and second sealing contact surfaces are pressed against each other by the water pressure from the supply line acting on the second disc.

[0062] Preferably, the second disc of the valve assembly is engaged with (or "mechanically connected to") a manually operable rotary actuator (e.g. a hand wheel) for rotationally driving the second disc relative to the first disc between a fully closed rotational position and a fully open rotational position.

[0063] The manually operable rotary actuator can be directly or indirectly mechanically connected to the second ("upper") disc of the valve assembly. In the case of a direct connection, the rotary actuator, including an optional stub axle integrally formed with the rotary actuator, rotationally drives the second disc relative to the first disc between a fully closed rotational position and a fully open rotational position. In the case of a direct connection, the rotary actuator is mechanically connected to the second ("upper") disc via an axle (or "shaft"), wherein the rotary actuator and the axle are separate pieces. Preferably, the axle can comprise two different separate pieces (an axle and a drive piece), wherein the rotary actuator is mechanically connected to the axle, the axle is in turn mechanically connected to the drive piece, and the drive piece is in turn mechanically connected to the second ("upper") disc.

[0064] Thus, a preferred dispenser comprises a manually operable rotary actuator (e.g. a hand wheel), a valve assembly comprising two ceramic discs, and an axle connecting the rotary actuator to one of the ceramic discs (preferably the second ("upper") disc), whereby turning the rotary actuator allows opening and closing of the valve.

[0065] It will be appreciated that the manually operable rotary actuator and the second ("upper") disc, and - if present - the axle and / or drive piece are mechanically connected to each other in such a way as to allow smooth and precise rotational movement, as will be explained in more detail below.

[0066] A preferred valve assembly as described herein is a mechanical valve assembly comprising a single pair of discs (preferably made of ceramic material) that can be integrated in a dispenser of a water purification system to replace both an electrically driven valve and an electromagnetic valve. The single pair of discs can be used to control both opening and closing of the flow through the valve assembly, as well as dispensing flow rates from dropwise dispensing to high flow, i.e. from 20 ml min -1 to up to 5 l min -1 , more preferably to up to 4 l min -1 , even more preferably to up to 3 l min -1and most preferably up to 2 l min -1 .

[0067] As described herein, this preferred mechanical valve assembly, as a result of its reduced size and complexity, offers one or more of the following advantages with respect to prior art products: (i) the ability to have several dispensers and / or dispensing devices dispensing at different flow rates simultaneously in a single water purification system; (ii) the ability to reduce the size of the dispensers and / or dispensing devices by removing the solenoid valves (and electric valves, if any) and the PCBs from the dispensers and / or dispensing devices, which provides for an improved ergonomic handling of the dispensers and / or dispensing devices; (iii) the ability to reduce the number of components and the complexity of the dispensers and / or dispensing devices and / or distribution system, in particular by avoiding having electronics, since there is no need to provide power or control circuitry from the main system comprising the water purification unit to the distribution system and / or dispensers and / or dispensing devices, and the connection between the main system and the distribution system and / or dispensers and / or dispensing devices can be reduced to a double pipe or a single pipe instead of two separate pipes and electronic cables, which can all have to be integrated in an outer sleeve or tied together by suitable means such as, for example, a cable tie; (iv) from an environmental point of view, the simplification of the structure and the lack of electronics is also beneficial, which reduces the carbon footprint of the distribution system and / or dispensing devices and / or dispensers and improves their recyclability; (v) the possibility of omitting electronic parts from the dispensing unit and / or distribution unit further simplifies the maintenance and repair of the unit (in case of need), since no electronic connections need to be established; (vi) from a manufacturing point of view, the valve assembly provides for a simplified and more stable (i.e. failure-free) assembly together with the liquid dispensing devices and / or dispensers provided with it; and (vii) finally, the valve assembly and the liquid dispensing devices and / or dispensers provided with it enhance the freedom of design: having electronic parts close to the hydraulic components in small and enclosed spaces constitutes a risk and can impose strict constraints on the design of the purified water distribution system(s) and / or dispensing device(s) and / or dispenser(s), forcing the liquid flow to enter from the lower part of the dispensers in most prior art products. The lack of electronics made possible by the use of the present mechanical valve assembly simplifies the constraints on the design of the distribution system and / or dispensing devices and / or dispensers and the overall water purification system, and from this point of view, therefore, reduces the risks.

[0068] Reference will now be made to the accompanying exemplary drawings Figure 4 to Figure 8a andFigure 8b The present invention is described in detail based on preferred exemplary embodiments.

[0069] Preferred valve assemblies and liquid dispensing device units for liquid dispensers as defined herein (particularly for water purification systems) are now described in conjunction with exemplary preferred embodiments.

[0070] The valve assembly (40) for the liquid dispenser (31) includes a pair of first discs (41) and second discs (42) (see Figures 3 and 42 respectively). Figure 4 They rotate relative to each other and have a first sealing contact surface (41a) and a second sealing contact surface (42a) facing each other arranged to slide at least partially into contact with each other.

[0071] The first disc (41) has at least one window (43a, 43b) (in the embodiment, the two are located opposite each other through the center of the disc). The second disc (42) has solid portions (44a, 44b) (which are arranged to completely cover and thus close the at least one window (43a, 43b) of the first disc (41) in the axial direction in a fully closed rotational position). Figure 6 (shown in the figure) and opening portions (45a, 45b) (which are arranged to at least partially expose the at least one window (43a, 43b) of the first disc (41) when rotated relative to it in a forward manner until it is positioned in a fully open rotational position). Here, in the embodiment, two solid portions (44a, 44b) and two opening portions (45a, 45b) complementary to the two windows (43a, 43b) of the first disc (41) are also provided.

[0072] Although two corresponding opening portions and solid portions are provided in a rotationally symmetric manner within the window, the number can be one of each or more than two distributed around the circumference.

[0073] As described later, the windows (43a, 43b) extend through the thickness of the first disc (41) in the axial direction and serve as a flow path for fluid to pass through the valve assembly (40) in the axial direction.

[0074] The solid portion(s) (44a, 44b) of the second disc (42) arranged to completely cover and thus to close the window(s) (43a, 43b) of the first disc (41) in the fully closed rotational position are formed so as to comprise a portion of the second sealing contact surface (42a) which overlaps the first sealing contact surface (41a) of the first disc (41) within a closed sealing zone (46a, 46b) around the edge (43c, 43d) of the window(s) (43a, 43b), respectively. The sealing zone (46a, 46b) has a width of at least 1.5 mm (preferably at least 2.0 mm) measured in the plane of the first and second sealing contact surfaces (41a, 42a) perpendicular to the edge (or more precisely perpendicular to the tangent with respect to the edge) to guarantee sealing in the fully closed position (see Figure 6 ). The sealing of the housing of the dispenser (31) in which the valve assembly (41) is integrated is achieved on the surface opposite to the first sealing contact surface (41a) of the first disc (41) (if the lower disc in the example of Figure 7 arrangement, then it can be the lower surface of the first disc) and thus a certain circular area without openings is required on the outside of this surface. These two requirements, in combination with the need to maximize the open area of the window (43a, 43b) to set the desired maximum dispensing rate as defined above, determine the size and shape of the two discs (41, 42) and the features.

[0075] The first disc (41) and / or the second disc (42) are preferably made of a ceramic material. Since the valve assembly (40) is particularly intended to be integrated in a dispensing device and dispenser (31) for ultrapure water, the type of ceramic material used should be chosen to avoid any contamination of the ultrapure water. Alumina ceramic is a suitable and preferred material. However, depending on the environment and whether the sealing performance of the sealing contact surfaces (41a, 42a) of the discs can be achieved, another material including a metal or an alloy or a different base material with a suitable covering layer including a ceramic covering layer is also possible.

[0076] The first disc (41) in the embodiment has a circular outer periphery and the second disc (42) has a non-circular outer periphery with open portions (45a, 45b) arranged to at least partially expose the at least one window (43a, 43b) of the first disc (41) radially recessed from the outer periphery (see Figure 5). However, the discs (41, 42) can have a peripheral shape other than circular. If the peripheral shape is "non-circular", it can facilitate keeping at least one disc (i.e. the stationary disc) in the housing of the dispenser (31) from rotating by engaging with a suitable counter-shape of a recess or a protrusion.

[0077] The first disc (41) is provided with positioning notches (47a, 47b) at the outer periphery for preventing rotation (in the mounted condition in the housing (32) of the dispenser (31) as shown in Figure 7 The positioning notches (47a, 47b) are formed and / or arranged asymmetrically around the circumference of the first disc (41) so as to define a unique mounting position.

[0078] The second disc (42) is provided with one or more drive member recesses (48a, 48b) and / or protrusions (not shown) on the side opposite to the second sealing contact surface (42a) in the axial direction for engaging with the rotational actuator (33) of the liquid dispenser (31). In an embodiment, the recesses (48a, 48b) are shallow cavities or grooves having a closed bottom not extending through the thickness of the second disc (42) in the axial direction. The rotational actuator (33) is provided with matching protrusions (33a, 33b) for engaging with the recesses (48a, 48b) (see Figure 7 ). The shape or profile of the recesses (48a, 48b) and the matching protrusions (33a, 33b) is asymmetric so as to define a unique mounting orientation or more precisely a rotational position of the actuator (33) where engagement is possible.

[0079] The sealing performance of the discs (41, 42) depends mainly on the percentage of the sealing contact surfaces (41a, 42a) of the discs that are effectively in contact at the microscopic level. Therefore, the disc sealing contact surfaces (41a, 42a) are treated to achieve a pre-set percentage of the contact surface between the two discs (41, 42). Too low a percentage would compromise the sealing, too high a percentage would cause excessive operational effort. As described below, since there is no external force exerted on the discs (41, 42) in the integration in the dispenser (31), this percentage of the disc surfaces (41a, 42a) in contact is the only parameter affecting the operational effort together with the water pressure and the sealing friction force on the drive actuator (33).

[0080] The first and second sealing contact surfaces (41a, 42a) of the pair of first and second discs (41, 42) arranged in at least partial sliding contact with each other have a surface quality or surface roughness Ra of at most 0.60 pm (more preferably at most 0.50 pm, most preferably at most 0.40 pm) and / or a flatness of at most 0.80 pm (preferably at most 0.70 pm, most preferably at most 0.60 pm) to form a fluid tight seal upon contact. Preferably, the first and second sealing contact surfaces (41a, 42a) of the pair of first and second discs (41, 42) are polished or ground.

[0081] The mutually facing first and second sealing contact surfaces (41a, 42a) of the pair of first and second discs (41, 42) are arranged such that a percentage of 50% to 80% (preferably 55% to 75%, and most preferably 60 to 70%) of the first and second sealing contact surfaces (41a, 42a) are in sliding contact with each other between the fully closed rotational position and the fully open rotational position.

[0082] The force needed to operate the valve assembly (40) is proportional to the axial force applied to the discs (41, 42): Friction force = normal force * friction coefficient Since the valve assembly is intended to be integrated in a water dispenser (31), for example in the form of an ergonomic, easy to use dispenser, the user will only hold and operate with his thumb over a relatively small angular range, low operating forces are critical. This is different from similar fluid valves that are driven by a motor or operated with the whole hand over a large angular range.

[0083] It is therefore critical to reduce the force needed to open and close the valve assembly (40) as much as possible for an ergonomic operation. To this effect, the axial force applied to the discs (41, 42) should be minimized in order to limit the friction force between the discs (41, 42) to a minimum. A large number of tests show that the water pressure is generally sufficient to press the discs (41, 42) together and achieve a seal without the need for additional forces.

[0084] As Figure 7 In the integration of the valve assembly (40) in a dispenser (31) as exemplarily illustrated in Fig. 1 1, the second disc (42) is arranged as the upper disc and is preferably mounted to contact the first disc (41) freely floating in order to minimize the operating force of the water dispenser (31). An axial stop is present in the upper manifold to determine and fix the height of the first or lower disc (41) and to achieve a seal between the first disc (41) and the housing with a custom seal (37a) (in Figure 7There is then a functional gap between the driving actuators (33) (i.e. of the protrusions (33a, 33b) in the recesses (48a, 48b) of the second disc (42) ) to guarantee - in addition to the force caused by the pressure of the fluid acting on the second disc (42) and pressing it against the first disc (41) - no other axial force applied between the discs (41, 42).

[0085] The reduced force of operation and the improved ergonomics can also be achieved not only by the optimization of the disc performance and the integration of the second or upper disc (42) free-floating, but also by the optimization of the rotary seal on the driving actuators (33).

[0086] It can be beneficial in certain applications to enhance the sealing effect by slightly biasing the second disc (42) towards the first disc (41) with a biasing member (not shown) (e.g. an elastic member similar to an elastic seal (e.g. an O-ring) or a spring arranged between the driving actuators (33) and the upper surface of the second disc (42)). Such a biasing member can be arranged (e.g.) in the space between the protrusions (33a, 33b) and the upper surface of the second disc (42) (not shown in the drawings).

[0087] For the intended use in a liquid dispenser (31) for ultrapure water, the disc design and disc performance are optimized to enable a wide range of flow rates: a good seal must be achieved in the fully closed position, and flow rates from a drop-like dispensing that is stable and easy to reach, up to the maximum dispensing rate as defined herein when the valve assembly (40) is fully open, with a limited pressure drop over a limited allowed operating ergonomics angle range that allows using the liquid dispenser (31) with only one hand, and operating with the thumb, while the rest of the hand keeps the device.

[0088] The discs (41, 42) of the valve assembly (40), in particular the size and arrangement of the window(s) (43a, 43b), the size and arrangement of the solid portions (44a, 44b) and the open portions (45a, 45b) are thus configured to set the range of rotation angles between the fully closed rotational position and the fully open rotational position to be between 50° and 70°, preferably between 55° and 65°, and most preferably about 60°.

[0089] The valve assembly (40) is dimensioned so as to provide a flow through the at least one window (43a, 43b) from drop-like (preferably 20 mL / min) up to the maximum defined dispensing rate as defined herein over the range of rotation angles of relative movement between the fully closed rotational position and the fully open rotational position.

[0090] In order to provide a stable and easily reached drop-wise dispensing, especially at the beginning of the operating range from the fully closed position (or, although not directly described in the following, correspondingly from the fully open position towards the end of the operating range), the at least one window (43a, 43b) of the first disc (41) has a notch / indentation (43e) recessed into the material of the first disc (41) from the plane defined by the first sealing contact surface (41a) of the first disc (41) at the edge (43c, 43d) of the at least one window (43a, 43b) which is at the side where the at least one window (43a, 43b) starts to be exposed when the second disc (42) is moved in the direction of the rotational position towards the fully open from the fully closed rotational position (see Figure 4 , Figure 6 and Figure 8b ).

[0091] The notch / indentation (43e) has a pointed sharp tip which gradually and continuously widens in the horizontal direction defined by the planar extension of the first sealing contact surface (41a) and / or which gradually deepens in the direction perpendicular to the plane towards the at least one window (43a, 43b). In other words, the surface of the cross-section of the notch / indentation (43e) increases in the circumferential direction of the first disc (41) towards the at least one window (43a, 43b).

[0092] Further, in order to smooth the flow of liquid when the second disc (42) is further rotated beyond the range of the notch / indentation (43e), the at least one window (43a, 43b) has a slope or ramp (43f) at the side wall adjacent to the side where the at least one window (43a, 43b) starts to be exposed when the second disc (42) is moved in the direction of the rotational position towards the fully open from the fully closed rotational position, so that the free opening width or surface of the cross-section of the at least one window (43a, 43b) gradually becomes narrower in the thickness or axial direction of the first disc (41) at least over a certain range as the distance to the plane of the first sealing contact surface (41a) increases.

[0093] As described before, the valve assembly (40) of the present invention is especially designed and advantageous for use in a liquid dispenser (31) for a water purification system. In Figure 7the preferred embodiment of the liquid dispenser (31) in cross-sectional view. The liquid dispenser (31) in the form of an ergonomically easy-to-use dispenser held by a single hand of a user while operating the valve assembly (40) by the thumb comprises a housing (35), a supply line (36) for purified water connected to a port (39) of the housing (35) directed towards an upper side, and an outlet (38) for purified water directed towards a lower side in a normally upright holding orientation.

[0094] According to the present invention, the valve assembly (40) is arranged in a receptacle (32) of the housing (35) such that the valve assembly (40) can control the volume or flow of purified water from the supply line (36), i.e. a unitary multi-lumen tubing as defined herein, to the outlet (38). The receptacle (32) is in communication with the port (39) and the outlet (38) of the housing (35).

[0095] The first disk (41) of the valve assembly (40) is rotationally fixed in a position within the receptacle (32) such that the at least one window (43a, 43b) is in communication with the outlet (38), e.g. by a protrusion (see Figure 4 engaging with a positioning notch (47a, 47b) at the outer periphery of the first disk (41) or by a matching shape of the receptacle.

[0096] The second disk (42) is shown mounted in the receptacle (32) so as to freely float in contact with the first disk (41) and such that the first and second sealing contact surfaces (41a, 42a) are pressed against each other only by the water pressure from the supply line (36) acting on the second disk (42) as described above.

[0097] The second disk (42) of the valve assembly (40) is engaged with a manually operable rotary actuator (33, 34) for rotationally driving the second disk (42) relative to the first disk (41) within the rotational range described above between a fully closed rotational position and a fully open rotational position. The rotary actuator comprises an axle (34) and a drive member (33) connected with a lower end of the axle (34).

[0098] Although the drive member (33) and the axle (34) can be made of the same material (i.e. essentially consisting of), it is preferred that the drive member (33) and the axle (34) are made of different materials. Preferably, the drive member (33) is made of (i.e. essentially consisting of) a material having a low content of leachable substances (i.e. having a low tendency to release contaminants). Non-limiting examples of materials suitable for the drive member (33) can be selected from the group consisting of polyoxymethylene and polypropylene. A preferred example of a material suitable for the drive member (33) is polyoxymethylene (POM). Preferably, the axle (34) is made of a material having a good mechanical strength (especially in terms of torsional strength) in order to allow an accurate and precise operation of the ceramic disc member, which is particularly necessary to find the drop-like dispensing position. Non-limiting examples of such materials suitable for the axle (34) can be selected from the group consisting of polyamide (PA), reinforced (e.g. with fiber reinforcement or talc) polyamide and reinforced (e.g. with talc) polypropylene. A preferred example of a material suitable for the axle (34) is polyphthalamide (PPA).

[0099] A part of the actuator (not shown in the drawings) extends outside the housing (35) and is accessible to the thumb of the hand for operation to rotationally drive the second disc member (42) and can be ergonomically shaped as desired. The rotating actuator is sealed against the housing (35) by an O-ring or gasket (37b) to prevent liquid from escaping the containment (32) other than through the outlet (38). If a floating positioning is implemented and the contact of the second disc member against the first disc member is achieved without introducing additional axial forces related to the operation of the rotation of the second disc member from the fully closed to the fully open rotational position, the specific design of the actuator is not critical (see Figure 8a and 8b ).

[0100] In an embodiment, the second disc member (42) is provided on the outer periphery with further lugs (44c, 44d) inserted into corresponding peripheral grooves (32a, 32b) of the containment (32) in order to guide and limit the rotational range of rotation of the second disc member (42).

[0101] In addition to considerations regarding hydraulic performance and availability, the shape and features of both discs (41, 42) are optimized for a simple and stable assembly process, wherein the possibility of misassembly (i.e. incorrect assembly) of the components in the housing (35) of the liquid dispenser (31) dispenser is very limited. In particular, the positioning notches (47a, 47b) on the first disc (41) to hold the first disc (41) in the correct position are not symmetrical in order to fit into the housing (32) in which the first disc (41) is integrated only in one position. The asymmetrical ribs (32c, 32d) in the housing (32) to hold the first or lower disc (41) in a fixed position also prevent the installation of the upper disc (42) in the wrong angular position (see Figure 8a and Figure 8b ).

[0102] The two lugs (33a, 33b) for engagement with recesses (48a, 48b) in the second or mobile disc (42) to drive the valve operation by means of the rotary actuator (33, 34) (see Figure 7 ) are also different from each other to allow only one angular position with respect to the axis of the actuator (33). This is important because the stops on the valve (fully open and fully closed) are defined between the axle and the housing (35).

[0103] The ribs (32e, 32f) between the peripheral grooves (32a, 32b) of the housing (32) serve to define these stops and therefore also affect the outer shape of the second or mobile disc (42), which should nevertheless be free to rotate over its operating range despite the presence of these ribs (32e, 32f).

[0104] The present application further relates to a method for dispensing purified water using the present dispensing device.

[0105] The present method for dispensing purified water thus comprises the steps of (A) providing a dispensing device comprising a dispenser as defined herein and a feed line; (B) providing purified water to the dispenser by means of the feed line; and (C) dispensing purified water by means of the dispenser.

[0106] Preferably, the present method for dispensing purified water comprises the steps of providing a dispensing device comprising a feed line and a dispenser as defined in detail herein, and providing purified water to the dispenser by means of the feed line, opening a valve assembly comprised in the dispenser, dispensing a desired volume of purified water from the dispenser, and closing said valve assembly.

[0107] Preferably, step (C) comprises the steps of (C1) opening the valve assembly comprising two ceramic disk members by manually operating the rotary actuator (thereby allowing purified water to flow through the dispenser and through the outlet); (C2) dispensing the desired volume; and (C3) closing the valve assembly.

Claims

1. A dispensing apparatus for dispensing purified water, the dispensing apparatus comprising (a) a dispenser comprising a valve assembly and a water outlet; and (b) a feed line providing purified water to and removing water from the dispenser, wherein the feed line comprises a unitary multi-lumen tubing comprising at least two separate lumens serving as flow paths for feeding water to and from the dispenser, respectively.

2. The dispensing device of claim 1, wherein the unitary multi-lumen tubing comprises, or preferably consists of: a low-solubility material, preferably a polymer, such as low-density polyethylene.

3. The dispensing apparatus according to claim 1 or claim 2, wherein the feed line is flexible.

4. The dispensing apparatus according to any one of the preceding claims, wherein the feed line comprises a protective sheath around the unitary multi-lumen tubing.

5. The dispensing apparatus according to any one of the preceding claims, wherein the unitary multi-lumen tubing comprises at least one central lumen and at least one outer lumen, preferably a plurality of outer lumens, separated / isolated from the central lumen.

6. The dispensing apparatus according to any one of the preceding claims, wherein the unitary multi-lumen tubing comprises at least two outer lumens, preferably at least three or four outer lumens, symmetrically distributed around the at least one central lumen.

7. The dispensing apparatus according to claim 5 or claim 6, wherein the feed line is connected or connectable to a water purification unit such that the flow of purified water towards the dispenser is directed through at least one of the at least one central lumens, and any flow of purified water back to the purification unit and / or another dispenser is directed through one or more of the outer lumens.

8. The dispensing apparatus according to any one of the preceding claims, wherein the valve assembly of the dispenser comprises two ceramic disks.

9. The dispensing apparatus according to any one of the preceding claims, wherein the dispenser comprises a manually operable rotary actuator and the valve assembly comprises two ceramic disks, wherein the rotary actuator is mechanically connected to one of the ceramic disks.

10. The dispensing apparatus according to any one of the preceding claims, wherein the dispensing apparatus and / or the dispenser does not require electricity.

11. A water purification system comprising the dispensing apparatus of any one of claims 1 to 10.

12. A method of dispensing purified water, the method comprising the steps of (A) providing the dispensing apparatus of any one of claims 1 to 10; (B) providing purified water to the dispenser through the feed line; and (C) dispensing purified water through the dispenser.

13. The method according to claim 12, wherein the dispensing apparatus is as described in any one of claims 2 to 10.

Images