Sealable pressure control device for pressurized fluid container, pressurized fluid container provided with such a sealable pressure control device and method for filling a pressurized fluid container

Abstract

The invention relates to a pressure control device (1) for attachment in a pressurized fluid container separating a dispersible fluid compartment and a propellant compartment, comprising a partition wall (2) provided with at least one propellant passage opening (4); and a closing element (5) attached to the partition wall moveable in a housing (10) wherein a housing opening (11) is propellant-tight sealable by the closing element (5). The invention also relates to a pressurized fluid container provided with a such pressure control device (1) and a method for filling such a fluid container.

Description

[0001] Sealable pressure control device for pressurized fluid container, pressurized fluid container provided with such a sealable pressure control device and method for filling a pressurized fluid container

[0002] The present invention relates to a sealable pressure control device for attachment in a pressurized fluid container separating a dispersible fluid compartment and a propellant compartment, comprising: a partition wall provided with at least one propellant passage opening; and a closing element attached to the partition wall moveable between a propellant passage opening release position and a propellant passage opening closing position. The present invention also relates to a pressurized fluid container provided with such a sealable pressure control device and to a method for filling a pressurized fluid container provided with a sealable pressure control device for according to the present invention.

[0003] Containers for pressurized dispersers fulfil multiple functions, including containing a fluid to be dispersed, and maintaining an overpressure inside the container for dispersing / dispensing of the fluid contained inside the container. In this respect the definition of a fluid is broad; it may be a gas, a liquid, a gel, a paste, a mousse or any type of mixture of such components. In the context of the claimed invention a “fluid” is thus to be interpreted in a broad sense as a “substance that flows”. All types of content in a container according to the present invention to be dispensed are to be included in the word “fluid”. A well-known problem with common dispersers is that the pressure at which the fluid to be dispersed is contained, changes over time, due to the leakage of propellant from the container as well as the decreasing level of the fluid to be dispersed because of normal use of the disperser. Although in common household applications - such as personal care products, paint, glue, and so on - a variation in pressure may be acceptable, other applications including the dispersing of high viscous substances such as sealants or caulks, or applications in a medical context, require accurate dosing control. However, in all applications a continuous pressure over the lifetime of the disperser containers is preferred.

[0004] To guarantee a constant and predictable outflow of fluid over the lifetime of the disperser, the pressure prevailing in fluid to be dispersed should thus be kept constant. More advanced disperser containers are therefore pressure controlled, for which they are provided with a compartment containing a highly pressurized propellant. The propellant compartment is furthermore provided with a pressure control valve that controls the outflow of propellant from the propellant compartment based on the pressure prevailing in the fluid to be dispersed, thereby keeping the fluid to be dispersed at a constant pressure. Such pressure control devices are known, for instance as disclosed in WO 2018 / 185652.

[0005] The dispersible fluid compartment and the propellant compartment may be embodied as parts (spaces) of a joint mantle (for instance the joint jacket of a spray can) that are separated from each other by a separation wall, in which separation wall the pressure control device is allocated. As an alternative it is for instance also possible that the propellant compartment is a completely enclosed container, which container is placed into a dispersible fluid compartment, and wherein the pressure control device is allocated in the wall of the enclosed (pressurized) container.

[0006] The US patent 5,428,942 discloses a method for filling a pressure capsule for spray cans. Hereby use is made of a valve having two chambers, which valve has a valve stem that opens and closes a discharge opening of the pressure capsule. The pressure is regulated by a moveable element such as a membrane that separates the two chambers, one chamber wherein a reference pressure is build up and one chamber wherein the surrounding pressure prevails.

[0007] The Belgium patent 1003980 disclosers a method for the assembly of spray cans and pressure capsules used thereby. Also here use is made of a moveable and flexible membrane that carries a valve, which valve cooperates with an aperture in a pressure capsule. A reference chamber, bordering one side of the flexible membrane controls the pressure level of the valve operating.

[0008] The object of the present invention is to provide an improved pressure control device and an improved pressurized fluid container provided with such a pressure control device that provides at least a comparable functionality as the prior art pressure control devices but that allows a fluid container to be simpler from construction and / or simpler to be pressurized and / or filled with dispersible fluid. The present invention provides for this purpose a pressure control device according to claim 1. Such a pressure control device enables to uncouple in time the pressurizing (filling to the required pressure level) of the propellant compartment and the filling of the dispersible fluid compartment. After pressuring the propellant compartment the indeformable closing element will be forced against the housing opening (for instance due to a mechanical intervention and / or the propellant pressure) thus locking the propellant compartment against the outflow of propellant. This “secured against outflow” situation of the propellant compartment provides time to fill the disperseable fluid compartment at a later moment in time and / or at a different location then when and where the propellant compartment is pressurized (filled). An important advantage is thus that the pressure control device according to the present invention provides flexibility to the propellant pressurizing and fluid filling process which thus enables further optimizing of these process steps. A further advantage of the present pressure control device is that it provides additional safety of the construction as the invention limits the chance of uncontrolled loss of propellant (e.g. in case of damage of the dispersible fluid compartment and / or a dispenser nozzle connecting to the dispersible fluid compartment). The housing may also act as a stabilisation of the orientation of the closing element during its traveling between the propellant passage closing position and the housing opening closing position. Furthermore the housing opening sealing position also functions as an abutment limiting the maximum freedom of movement of the closing element; the closing element is thus restricted to movement within the housing. As the closing element is an indeformable part (not deformable I solid) it is easy to produce, simple to handle and not wear sensitive thus limiting the production costs and enhancing the reliability of the pressure control device.

[0009] Between the closing element and the partition wall a propellant-tight enclosed pressure chamber with variable volume is provided. This propellant-tight enclosed pressure chamber when at least partially compressed is exerting a pressure on the inside of the closing element forcing the closing element away from the at least one propellant passage opening, and when the external pressure in the dispersible fluid compartment is not able to withstand the pressure in the pressure chamber, thus opening the propellant passage opening in the separation wall. The result of opening the (at least one) propellant passage opening is that at least as long as the closing element is not propellant tight sealing the housing opening - propellant will flow from the propellant compartment into the dispersible fluid compartment until the pressure in the dispersible fluid compartment is risen to a level that the closing element is pushed back (against the pressure in the pressure chamber) to the position wherein the closing element seals off the propellant passage opening in the separation wall again.

[0010] The present invention also involves the housing - except for the housing opening - being propellant-tight connected to the partition wall and surrounding the propellant passage opening. This implies that the housing only has two openings on two sides; at least one in the part of the partition wall that is enclosed by the housing and one on the opposite side of the closing element that is placed in the housing, which normally is on the opposite side of the housing than where the opening in the partition wall is provided. Anyhow the two sided openings are on the opposite sides of the closing element, and the closing element is able to fluid-tight (medium-tight) closing off the openings on one of the sides at the same time; or the at least one opening in the partition wall or the opening on the opposite side.

[0011] Preferably the housing opening is provided with a sealing edge directed towards the closing element. The shape of such a sealing edge, also referred to as a seat, has to follow the complementary shape of the side of the closing element counteracting with the sealing edge due to requirement of providing a propellant- tight connection (fit) of the sealing edge and closing element. Likewise and vice- versa is it preferred that the closing element has a contact rim that propellant-tight fits the sealing edge of the housing opening. Also in the choice of material of both the sealing edge and closing element it is preferred to take the required propellant- tight connection in mind.

[0012] As during operation of the pressure control device according to the present invention in a situation wherein propellant has to pass the pressure control device for driving the dispersible fluid out of the dispersible fluid by feeding propellant into the dispersible fluid compartment between the closing element and the housing preferably a propellant permeable passage is provided. Such passage is thus to be used in situations wherein the closing element is not closing off both the propellant passage opening and the housing opening (and thus propellant is to flow from the propellant compartment to the dispersible fluid compartment. In an embodiment the housing moveable holding the closing element may be circle- symmetrical. Such a circle-symmetrical housing is relatively simple to produce but also simplified the assembly of the housing and the closing element. Preferably also the closing element is hood-shaped. Such a simple cap-shaped construction of the closing element is simple to produce, compact and relatively simple to be guided along a guide element. A specific and very simple cup shape is in cross section U-shaped, thus not possessing a border or rim that protrudes from an upright sidewall of the closing element. Even more preferred is that the closing element is circle symmetrical, simplifying the assembly, positioning and functioning of the closing element.

[0013] The partition wall may be provided with a protruding guide element, such that the closing element may surround the protruding guide element. Hereby the propellant passage opening in the partition wall may be allocated in or adjacent the protruding guide element. The closing element and such protruding guide element may be moveable connected such that the closing element and the protruding guide element are propellant-tight enclosing a pressure chamber. This provides a simple yet stable and reliable pressure control device.

[0014] In a specific embodiment the protruding guide element is surrounded by a slotshaped channel, which slot-shaped channel may be recessed in the partition wall. The slot-shaped channel is supportive in holding in position of the closing element, especially in the position wherein the closing element is in the propellant passage opening closing position. Furthermore the advantage of the slot-shaped channel surrounding the protruding guide element may limit the height of the protruding guide element required for proper functioning of the pressure control device according to the present invention.

[0015] When use is made of a slot-shaped channel the at least one propellant passage opening may well be allocated in the slot-shaped channel. Such will help to protect the propellant passage opening against contamination but even more will help to ensure a correct closing of the propellant passage opening by the closing element. These advantages are even more provided in case the at least one propellant passage opening is allocated in the bottom of the slot-shaped channel. In a further alternative embodiment the partition wall may be provided with a indented recess providing the basis for a pressure chamber with variable volume and the propellant passage opening is allocated in the partition wall outside the indented recess. In such embodiment the indented recess in the partition wall is functioning as (a part of) the flexible pressure chamber which allows a different mutual design of the propellant compartment and the dispersible fluid compartment.

[0016] The closing element may have a flexible sealing material surface there where contacting the propellant passage opening and / or there where contacting the housing opening as such may ensure a propellant-tight closing off of the propellant passage opening and the housing opening. For the same reasoning alternatively or additionally also the closing element may be covered with a flexible sealing material layer.

[0017] The present invention also provides a pressurized fluid container provided with a pressure control device as disclosed above and according to the present invention, wherein the pressure control device is attached in the pressurized container separating a dispersible fluid compartment from a propellant compartment such that the at least one propellant passage opening in the separating wall is the only fluid-permeable connection between the dispersible fluid compartment and the propellant compartment. With such pressurized fluid container the advantages as described above in relation to the pressure control device according to the present invention are realised, among which the advantages of more freedom in the subsequent filling (propellant and dispersible fluid) of the pressurized fluid container is important.

[0018] In an embodiment of the pressurized fluid container the propellant compartment may be an individual container that is placed in a larger dispersible fluid compartment. In such embodiment the propellant compartment may be considered to be a “loose” insertable pressure unit that is placeable in a larger disperseable fluid compartment, which simplifies the construction of the pressurized fluid container as a separation wall has not to be attached to the further construction. In such embodiment the shape of the propellant compartment is not limited other than that it has to fit within the dispersible fluid compartment and that it can withstand the pressure. An alternative design choices may consist of the fluid container being a cylindrical spray can and the partition wall being disc-shaped separating a dispersible fluid compartment and a propellant compartment. The shape of the pressurized fluid container is free of choice, in practise often cylindrical cans are used, which may for instance be made out of aluminium, tin plate material or a plastic like for instance PET. In a further embodiment the propellant compartment of the pressurized fluid container may be provided with a separate filling valve, preferably a one-way valve. Such an additional filling valve may enable to by-pass the pressure control device during pressurizing of the propellant compartment.

[0019] The present invention also provides a method for filling a fluid container according to the present invention, comprising the successive method steps: A) filling the propellant compartment to above working pressure level with the closing element in an intermediate position in the housing letting the propellant passage opening and the housing opening both in an open position; B) propellant-tight closing off the pressurised propellant compartment by letting the closing element propellant-tight sealing the housing opening; and C) filling and pressuring the dispersible fluid compartment whereby the applied increased pressure in the dispersible fluid compartment displaces the closing element from the housing opening sealed position to a propellant passage opening closed position. The working pressure level herein is to be understood as the regulated pressure level at which the fluid leaves the fluid container. The propellant compartment has thus to be filled (pressurized) to a pressure level that is so much higher than the working pressure level (or regulated pressure level) that the propellant is able to completely empty the dispersible fluid compartment (preferably including some reserve). The applied increased pressure in the disperseable fluid compartment has to be intentionally so high that the closing element is moved to a position wherein the closing element closes off the propellant opening (and not the housing opening anymore). Due to the method step B), the closing off of the pressurised propellant compartment by letting the closing element propellant-tight sealing the housing opening, the method steps B) and C) may be separated in time what provides substantial logistic advantages in the filling process as there are less restrictions (hard couplings) in the process thus enabling to further optimise the various process steps (or subprocesses) of the filling method. As an example of such freedom in the filling process a propellant compartment including a pressure control device as a separate part may be pressurized, to subsequently insert the pressurized propellant compartment in a larger dispersible fluid compartment.

[0020] The invention will now be elucidated with reference to the non-limitative exemplary embodiments illustrated in the following figures. Corresponding elements are denoted in the figures by corresponding reference numbers. Herein shows: figures 1A, 1 B schematic longitudinal cross-section views on a pressure control device according to the present invention, wherein the position of a closing element is that is part of the pressure control device is varied; figure 1 C a perspective cross-section view of a housing as part of the pressure control device shown in the figures 1A and 1 B; figure 2 a longitudinal cross-section of a pressurized fluid container according to the invention; figure 3 a longitudinal cross-section of an alternative embodiment of a pressurized fluid container according to the invention; figure 4 a cross-section view of propellant compartment including a pressure control device according to the present invention; figure 5A a schematic longitudinal cross-section views on an alternative embodiment of a pressure control device according to the present invention; and figure 5B a schematic longitudinal cross-section views on a further alternative embodiment of a pressure control device according to the present invention.

[0021] Figure 1 A shows a pressure control device 1 for attachment in a pressurized fluid container (see figure 2 and 3) having a partition wall 2 that is provided with a surrounding mounting edge 3. In the partition wall 2 a propellant passage opening 4 enables a propellant (normally a gas) to pass the partition wall 2, at least as long as a closing element 5 is not closing off the propellant passage opening 4. In the position of the closing element 5 as depicted in figure 1 A the closing element 5 is in “a propellant passage opening 4 closing off position”. The closing element 5 here is hood-shaped and surrounds a protruding cylindrical guide element 6 that is centrally allocated on the partition wall 2, which protruding guide element 6 is surrounded by a slot-shaped channel 7 that is recessed in the partition wall 2. The propellant passage opening 4 is allocated in the bottom of the slot-shaped channel 7. On the bottom of the inside of the hood-shaped closing element 5 an inside annular sealing element 8 (functioning as an “O-ring”) seals off the contact between the closing element 5 and the protruding guide element 6, thus providing a propellant-tight pressure chamber 9 with a volume that is variable due to the movement of the closing element 5 relative to the protruding guide element 6 and that functions as a pressure regulator. Connected (propellant-tight connected) to the partition wall 2 is a housing 10 that moveable holds the closing element 5 and the propellant passage opening 4, such that the propellant passage opening 4 is located within housing 10. On the side of the housing 10 facing away from the propellant passage opening 4 the housing 10 comprises a housing opening 11 . The housing opening 11 shows a seat 12 (a sealing edge) that is propellant-tight sealable by the closing element 5. The housing opening 11 closed-off is shown in figure 1 B, wherein the closing element 5 is forced against the seat 12 of the housing opening 11 due to pressure from propellant that is stored in a propellant compartment 13. In the situation as depicted in figurel B the propellant compartment 13 is likely to be pressurized and there is no counter pressure (on top of the closing element 5) that fully cancels the pressure of the closing element 5 against the seat 12 of the housing opening 11 . The housing 10 holds and guides the moveable closing element 5 and between the housing 10 and the side of the closing element there is enough space (an aperture 14) so that in an intermediate position of the closing element 5 (thus not a position wherein the closing element 5 is closing-off the propellant passage opening 4 or closing-off the housing opening 11 ) to let a propellant pass this aperture 14. The seat 12 of the housing opening 11 . Also functions as a limitation for the trajectory of movement of the closing element 5.

[0022] The housing 10 is shown individualised in figure 1C, more clearly showing the protruding cylindrical guide element 6 that is centrally allocated in the housing 10. and that is surrounded by a slot-shaped channel 7 recessed in the partition wall 2. Also within the housing 10 the propellant passage opening 4 is visible. The housing 10 here is fully integrated with the partition wall 2 thus providing the required propellant-tight connection of the partition wall 2 and the housing 10. Figure 2 shows a perspective cross-section view on the pressurized fluid container 20. A cylindrical shell 21 of the container 20 is provided with an circumferential indention 22 and on the outfeed (upper) side of the container 20 a neck 23 and shoulder 24 are applied with a central outlet tube 25 (stem) that may be connected to a (aerosol) valve. The upper side of the pressure control device 1 as shown in figures 1 A and 1 B borders a dispersible fluid compartment 26, in which fluid compartment 25 a piston 27 may be moved towards the outlet tube 25 whereby the dispersible fluid in the compartment 26 will be placed under pressure enabling to release a portion of the fluid to be dispersed. The container is separated in the upper dispersible fluid compartment 26 and a lower propellant compartment by the partition wall 2, which partition wall is propellant-tight connected to the walls of the cylindrical shell 21 of the pressurized fluid container 20. The pressure control device 1 acts as a constant pressure release valve that opens for propellant to pass from the propellant compartment 27 to the fluid compartment 25. The propellant compartment 27 functions as a reservoir for a (highly) compressed propellant. Suitable propellants include propane, butane, carbon dioxide, nitrogen, air or any other suitable substance. Preferably, a propellant is chosen that does not chemically react with the dispersible fluid especially when the propellant may contact the dispersible fluid (as may occur in a “diptube” embodiment).

[0023] Figure 3 shows a longitudinal cross-section of an alternative embodiment of a pressurized fluid container 30 according to the invention, wherein again the pressure control device 1 is incorporated but wherein also an additional filling valve 31 is included in the partition wall 2. The filling valve 31 here is a one-way umbrella valve. During and after pressurising the propellant compartment 27 (when there is no substantial over-pressure in the dispersible fluid compartment 26 that still has to be filled) the closing element 5 will be forced against the seat 12 in the housing opening 11 (for details if the control device 1 see figures 1 A - 1C).

[0024] Figure 4 shows a propellant compartment 40 that is here not part of a larger construction but that as a “stand-alone” element. The propellant compartment 40 is provided with the pressure control device 1 as shown before. The propellant compartment 40 may (e.g. after being pressurized) brought into a dispersible fluid compartment with a high freedom in shape. In figure 5A an alternative embodiment of a pressure control device 50 according to the present invention is shown. Here a partition wall 51 is provided with a recess 52 forming a pressure chamber 53 with variable volume. In the partition wall 51 a propellant passage opening 54 enables a propellant to pass the partition wall 51 , at least as long as a closing element 55 is not closing off the propellant passage opening 54. The closing element 54 here has a different shape than the closing elements 5 as shown in the previous figures., but also here the closing element 54 is movable allocated in a housing 56 in which housing 56 also the propellant passage opening 54 is allocated. The housing 56 has an housing opening 57 with a seat 58. In the position of the closing element 55 as depicted in figure 5A closing off the housing opening 57. For a further functioning of the pressure control device 50 reference is made to the previous description.

[0025] In figure 5B a further alternative embodiment of a pressure control device 60 according to the present invention is shown. Here again a partition wall 61 is provided with a recess 62 here holding a closing element 63. In the partition wall 61 a propellant passage opening 64 enables a propellant to pass the partition wall 61. The closing element 63 again has a different shape than the closing elements 5, 55 as shown in the previous figures, but also here the closing element 63 is movable allocated in a housing 66 that corresponds with the recess 62. In the housing 66 the propellant passage opening 64 is allocated. The housing 66 has an housing opening 67 with a seat 68. In the position of the closing element 63 as depicted in this figure closing off the housing opening 67.

Claims

Claims1 . Pressure control device for attachment in a pressurized fluid container separating a dispersible fluid compartment and a propellant compartment, comprising:- a partition wall provided with at least one propellant passage opening;- an indeformable closing element moveable between a propellant passage opening release position and a propellant passage opening closing position between which closing element and the partition wall a propellant-tight enclosed pressure chamber with variable volume is provided; and- a housing moveable holding the closing element, wherein the housing comprises a housing opening, which housing opening is on the opposite side of the closing element than the propellant opening in the partition wall, wherein the housing is except for the housing opening propellant-tight connected to the partition wall and surrounds the propellant passage opening.

2. Pressure control device according to claim 1 , characterised in that the housing opening is provided with a sealing edge directed towards the closing element.

3. Pressure control device according to claim 2, characterised in that the closing element has a contact rim that propellant-tight fits the sealing edge of the housing opening.

4. Pressure control device according to any of the preceding claims, characterised in that between the closing element and the housing a propellant permeable passage is provided.

5. Pressure control device according to any of the preceding claims, characterised in that the housing moveable holding the closing element is circle symmetrical.

6. Pressure control device according to any of the preceding claims, characterised in that the closing element is circle symmetrical.

7. Pressure control device according to any of the preceding claims, characterised in that the partition wall is provided with a protruding guide element, wherein the closing element is surrounding the protruding guide element, and wherein the propellant passage opening in the partition wall is allocated in or adjacent the protruding guide element.

8. Pressure control device according to claim 8, characterised in that the protruding guide element is surrounded by a slot-shaped channel.

9. Pressure control device according to any of the claims 1 - 6, characterised in that the partition wall is provided with an indented recess providing the basis for a pressure chamber with variable volume and the propellant passage opening is allocated in the partition wall outside the indented recess.

10. Pressure control device according to any of the preceding claims, characterised in that the closing element has a flexible sealing material surface there where contacting the propellant passage opening and / or there where contacting the housing opening.11 . Pressurized fluid container provided with a pressure control device according to any of the preceding claims, wherein the pressure control device is attached in the pressurized container separating a dispersible fluid compartment from a propellant compartment such that the at least one propellant passage opening in the separating wall is the only fluid-permeable connection between the dispersible fluid compartment and the propellant compartment.

12. Pressurized fluid container according to claim 11 , characterised in that the propellant compartment is an individual container that is placed in a larger dispersible fluid compartment.

13. Method for filling a fluid container according to claim 11 or 12, comprising the successive method steps:A) filling the propellant compartment to above working pressure level with the closing element in an intermediate position in the housing letting the propellant passage opening and the housing opening both in an open position; B) propellant-tight closing off the pressurised propellant compartment by letting the closing element propellant-tight sealing the housing opening; and C) filling and pressuring the dispersible fluid compartment whereby the applied increased pressure in the dispersible fluid compartment displaces the closing element from the housing opening sealed position to a propellant passage opening closed position.

14. Method for filling a fluid container according to claim 13, whereby the method steps B) and C) are separated in time.

15. Method for filling a fluid container according to claim 13 or 14, whereby a propellant compartment including the pressure control device as a separate part is pressurized and subsequently is inserted in a larger dispersible fluid compartment.

Images