EP0833787B1

EP0833787B1 - Beverage frothing

Info

Publication number: EP0833787B1
Application number: EP96914304A
Authority: EP
Inventors: Alexander Richard Dunn; Graham Court
Original assignee: Scottish and Newcastle Ltd
Current assignee: Heineken UK Ltd
Priority date: 1995-05-19
Filing date: 1996-05-17
Publication date: 2001-10-24
Anticipated expiration: 2016-05-17
Also published as: EP0833787A1; AU5771296A; CA2221251A1; NZ308159A; WO1996036545A1; AU709488B2; CA2221251C

Description

This invention relates to generating a foaming dispersion of bubbles within a liquid packed within a sealed, broachable container. It is particularly, though not exclusively, suited for use with canned or otherwise packaged beverages, for example, beer, ale, porter, stout or lager, to produce a close knit, creamy head on the beverage when the sealed beverage is opened.

WO 95/03982 provides a device for generating a head on a liquid in a sealed and pressurised can, when the can is opened, comprising a hollow capsule which initially floats on the liquid so that apertures in the capsule are initially disposed one above and one below the liquid level surface, liquid being drawn up into the container through the immersed aperture by an absorbent wick combining with ballast means eventually to cause the capsule to at least partially invert and trap gas under pressure within the capsule, ready for release when the can is opened to issue through a small aperture as a fine jet into the liquid and bubble to the liquid surface.

According to a first aspect, the present invention provides a device consisting of only two components for inclusion in a pressured beverage container for jetting as into the beverage upon opening the container, the two components being joined together to define an internal chamber, spaced first and second permanently open orifices, the internal chamber being adapted to contain pressurised gas and a quantity of liquid such that the second orifice is located above, and the first orifice below, the level of liquid in the device prior to firing of the device when the container is opened, and the second orifice communicates with the internal chamber through a standpipe which, immediately prior to firing of the device opens into the internal chamber below the surface level of the liquid held within the device and in which, upon firing, liquid from within the device is forced towards the second orifice such that the pressurised gas from the internal chamber is expelled preferentially through the first orifice into the beverage.

The invention also provides for a pressurised beverage container containing such a device.

According to a second aspect, the present invention provides a pressurised beverage container having therein a device for releasing pressurised gas into liquid contents of the container when the container is opened to the atmosphere, the device consisting of only two components joined together to define an internal chamber containing a liquid and a gas at a pressure greater than atmospheric pressure, the device having a first orifice opening into the beverage held within the container, and a second orifice opening into a gas-filled head space of the container and in which the second orifice opens into the internal chamber at a position below the surface level of the liquid held therein.

The second orifice may be positioned above the first orifice. The second orifice may open into a passageway, the passageway providing communication between the second orifice and a position in the internal chamber below the surface level of the liquid held therein.

The liquid within the internal chamber is preferably beverage which has been transferred to the internal chamber from the container.

The second orifice may open directly into the head space above the liquid in the container.

Preferably, the second orifice opens into the chamber through a passageway which opens close to but spaced from a wall of the chamber below the level of the beverage in the container. A corresponding passageway may extend from the first orifice to open close to but spaced from a wall of the chamber above the level of the beverage in the container.

The device may be reversible so that the first orifice and the second orifice are interchangeable in function.

The first and/or second orifices may be permanently open and provide permanent fluid communication between the interior and the exterior of the device.

The device may be buoyant in the liquid or may be fixed in position in the container; it may be weighted to assume a desired position with respect to the liquid beverage in the container.

According to a further aspect, the present invention provides a method of generating a dispersion of bubbles within a beverage comprising the steps of:

a) providing a device (10, 60, 80) consisting of only two components, within a sealed, pressurised beverage container (25) containing a liquid (26, 86), the two components being joined together to define an internal chamber (29, 66) provided with spaced first and second permanently open orifice (21, 71, 81, 24, 74, 84);

b) arranging for the internal chamber (29, 66) of the device (10, 60, 80) to contain pressurised gas and a quantity of liquid immediately prior to opening the container (25), the first orifice being located below the level of the liquid in the device and the second orifice being located above the liquid in the device;

c) and the device (10, 60, 80) is disposed in the container (25) to extend partially within the liquid (26, 86) and partially in a gas filled head space (28) above the liquid (26, 86) and the second orifice is located above the liquid (26, 86) in the container (25) when the container (25) is in its normal attitude for opening and further providing a passageway (23, 72, 92) extending from the second orifice to a point below the level of liquid in the device and, arranging that, upon opening of the container (25), a quantity of the liquid held within the device (10, 60, 80) is moved by the pressurised gas along the passageway (23, 72, 92) to contact the second orifice (24, 74, 84) so that pressurised gas from the internal chamber (29, 66) is jetted preferentially from the internal chamber (29, 66) through the first orifice (21, 71, 81) into the beverage in the container (25).

Preferably, the container is only partially filled with the beverage and the top of the container is dosed with liquid nitrogen prior to sealing to provide a gas filled head space. The device is arranged to assume a position partially in the beverage and partially in the head space. The first passageway emerges at the exterior of the peripheral wall below the surface level of the liquid and the second passageway emerges at the exterior of the peripheral wall above the surface level of the liquid.

The device may be substantially filled with a non-oxidising gas, for example, nitrogen, prior to insertion in the container. The non-oxidising gas may be forced into the device through the first passageway to expel gas previously in the device through the second passageway to purge the device.

The device may be positioned in the container prior to or after the beverage has been placed in the container.

Pressure in the container may be increased as a result of evaporation of liquid nitrogen once sealed and/or release of gas from the beverage due to the beverage being supersaturated with gas and/or raising the temperature of the beverage, for example, during pasteurisation.

When the pressure within the container is increased, gas from the primary head space at the top of the container is preferably forced through the second orifice and/or second passageway into the device and some beverage is forced through the first orifice and/or first passageway into the device. When the pressure stabilises, beverage within the device preferably assumes an internal beverage level between the first and third position with a secondary, pressurised, gas filled head space above the internal beverage level within the device.

In this configuration, the first passageway provides fluid communication between the first position (within the secondary head space) and the second position at the exterior of the insert (below the beverage level in the container). The second passageway provides fluid communication between the third position (within the internal chamber below the internal beverage level) and the fourth position at the exterior of the insert (above the beverage level in the container).

When the container is broached, gas from the secondary head space within the internal chamber is preferably forced through the first passageway into the beverage to generate a dispersion of bubbles. Beverage from within the device may be forced out of the device through the second passageway.

The or each passageway may be provided as standpipes which provide a liquid lock/gas lock in the device.

Embodiment of the device will now be described, by way of example only, with reference to the accompanying drawings of which:

Fig.1: shows a first embodiment of a device in cross-section prior to insertion in a container;
Fig.2: shows the device of Fig 1 inserted in a partially filled beverage container prior to sealing of the container;
Fig.3: shows the arrangement of Fig.2 once the container has been sealed and pressurised;
Fig.4: show the arrangement of Fig.3 when the container is opened;
Fig.5: shows the arrangement of Fig.4 once gas has been jetted from the device into the beverage;
Fig.6: shows an alternative device in cross-section;
Fig.7: shows a further alternative device in cross-section;
Fig.8: shows the arrangement of Fig.7 at an initial stage of firing the device;
Fig.9: shows the arrangement of Fig.7 and Fig.8 at a subsequent stage of firing the device;
Fig.10, Fig.11, Fig.12, and Fig.13: show various retainers for the device; and
Fig.14: shows a further form of device.

The substantially cylindrical device 10 of Fig.1 comprises a first cup shaped member 11 attached to a second member 12 in the form of a cap. The members are joined by a circumferential snap fit 14 connection (which also provides a seal) and together provide a peripheral wall 15 which defines an internal chamber 16 within the device 10. In this embodiment the cap 12 provides a base portion 17 of the device and a top portion 18 of the device is provided by the cup shaped member 11.

The device 10 is provided as a separate hollow insert for inclusion in a beverage container. It is preferably provided containing a non-oxidising gas at substantially atmospheric pressure.

A first extension tube or standpipe 19 is formed integrally with the cap 12 and defines a first passageway 20 which provides fluid communication from a first position 1 within the internal chamber 16 to a second position 2 at the exterior of the base portion 17 of the device. The first passageway 20 is provided with a first restricted orifice 21 where it passes through the peripheral wall 15 of the device.

A second extension tube or standpipe 22 is formed integrally with the cup shaped member 11 and defines a second passageway 23 which provides fluid communication from a third position 3 within the internal chamber 16, spaced from and positioned below the first position 1, and a fourth position 4 at the exterior of the top portion 18 of the device, spaced from and positioned above the second position 2. The second passageway 23 is provided with a second restricted orifice 24 where it passes through the peripheral wall 15 of the device.

Each of the first and

second members

11, 12 forming the device 10 is moulded from a plastics material. The device 10 is substantially rigid when assembled.

One or each of the

orifices

21, 24 may be moulded integrally with the device, formed in some other way or provided as a separate insert. Each orifice has substantially the same cross-section.

In this embodiment, each of the

extension tubes

19, 22 extends a similar distance into the interior of the device. The device is adapted to float either way up at the surface of a beverage in a container.

In use, the device 10 is flushed with nitrogen gas and dropped into a container in the form of a can 25. The can 25 is partially filled with a beverage, in this case a beer 26 supersaturated with gas, from a filler head (not shown) in the usual way. As illustrated in Fig 2, the device 10 floats at a surface level 27 of the beer 26 within the can 25 such that it is partially submerged, the first orifice 21 of the first passageway 20 being below the surface level 27 of the beer within the container and the second orifice 24 of the second passageway 23 being above the surface level 27 of the beer within the container.

The top of the can 25 is then dosed with liquid nitrogen and the can is seamed in the usual way. The liquid nitrogen evaporates creating a nitrogen filled primary head space 28 in the sealed can. As more nitrogen evaporates the internal pressure in the can rises and gas from the primary head space 28 is forced into the device 10 through the second orifice 24 and the second passageway 23. Beer 26 is also forced into the device through the first orifice 21 and the first passageway 20, but much more slowly.

When the pressure inside the can stabilises, the device is left partially filled with beer with an internal, secondary head space 29 filled with gas at a pressure substantially equal to that within the primary head space 28. As show in Fig.3, the internal beverage level 30 lies between the first 1 and third 3 positions such that the first passageway 20 emerges into the secondary head space 29 and the second passageway 23 emerges below the internal beverage level 30.

The beverage container may be pasteurised in a way known in the art; this may involve inversion of the container.

Operation of the device relies on the phenomenon that a gas will pass much more quickly (at the greater flow rate) than a liquid through a similar restricted orifice when subjected to the same pressure.

The sealed can 25 is broached or opened by, for example, operation of a can ring pull (not shown). This causes the pressure in the primary head space 28 to drop rapidly to atmospheric pressure. At this time, pressure within the device 10 is greater than atmospheric pressure thus creating a pressure differential across each of the

orifices

21, 24. Consequently, gas trapped within the second passageway 23 between the internal beverage level 30 and the second orifice 24 is expelled from the second orifice 24. At the same time, liquid trapped within the first passageway 20 is expelled from the first orifice 21 into the beer 26.

Once all the gas initially trapped within the second passageway has been expelled, beer from the internal chamber within the device 10 is forced up the second passageway 23 (as shown in Fig. 4) due to the pressure differential between the internal chamber 16 and the exterior of the device. The liquid beer contacts the second orifice 24 and is forced therethrough but at a lesser rate that gas is forced through the orifice due to its greater viscosity with respect to the gas. During this time, all of the beer initially trapped in the first passageway 20 is expelled and gas from the secondary head space 29 is jetted through the first passageway 20 and the first orifice 21 into the beer within the container. At this point, the pressure differential across each of the orifices is substantially equal but gas is expelled from the first orifice 21 preferentially to liquid being expelled from the second orifice 24 due to the relative ease of passage of the gas through the first orifice 21 as compared with the passage of liquid through the second orifice 24. In fact, the gravitational weight of the liquid trapped within the second passageway 23 will tend to reduce the pressure differential across the second orifice 24 as compared to that across the first orifice 21.

In effect, the pressure of the gas in the secondary head space 29 forces beer from the bottom of the device up through the second passageway 23 and through the second orifice 24 but also forces gas from the top of the device preferentially through the first passageway 20 and out through the first orifice 21 into the beer 26 to cause the desired effect. In this way, the beer initially held within the device 10 acts together with the second passageway 23 to restrict flow of liquid from the internal chamber 16 directly in to the gas filled head space 28 above the beverage and provides flow of gas from the internal chamber 16 through the first orifice 21 in preference to flow of liquid through the second orifice 24.

Preferably, the flow of gas from the first orifice 21 into the beer 25 only seeds bubble and head formation at the top of the beer; this can help to reduce gushing. The rest of the beer 26 is preferably seeded as it is poured out of the can 25, for example into a glass.

Nearly all of the beer originally held within the device is pumped out during this process, as illustrated in Fig.5.

Fig.6 shows an alternative device 60 that operates in a similar way; the main differences between this and the previously described embodiment are as follows.

This device 60 is substantially spherical and comprises first and second cup shaped

member

61, 62; it is intended to float only one way up. The device 60 is weighted with its centre of gravity in the second (lower) hemisphere 62 such that it is self-righting when floating in liquid.

The first extension tube 69 does not extend as far into the internal chamber 66 as the second extension tube 72. This does not hinder operation as, since the device is always orientated the same way up (ie as shown when in use) the internal beverage level (not shown) within the internal chamber 66 when pressurised is arranged to be below the end of the first extension tube 69. Reducing the length the first extension tube 69 extends upwards into the internal chamber 66 also reduces the quantity of beer which collects in this tube 69 during pressurisation and hence reduces the quantity of beer that must be ejected from the tube 69 before gas from the secondary internal head space can be expelled.

Since the orientation of the device 60 is predetermined, the two

orifices

71, 74 may be designed to be hydrophobic in the appropriate directions to improve performance.

Fig.7, Fig.8 and Fig.9 show a further alternative device, which operates on a similar principle to the previously described devices.

The device 80 is substantially spherical; it is made from two hemispheres of different wall thickness and is weighted so that it always floats on the liquid beverage 86 in a can (not shown) with a first orifice 81 below the surface level 87 of the beverage 86 and a second orifice 84 above the surface level 87.

The device 80 may be placed in a can before filling the can with beverage, for example using a volumetric filler, or between the can being filled and sealed.

With this device, a first extension tube 89 extends only a very small distance into the interior of the device. A second extension tube 92 extends co-linearly to the first extension tube 89 from the second orifice 84 to a position slightly above the first extension tube.

The first and second orifices are substantially the same size; when the can containing the device 80 is pressurised, the ratio of gas forced into the device through the second orifice 84 to liquid forced into the orifice through the first orifice 81 is about 20:1. Consequently, only a small amount of beverage enters and is retained within the device but the arrangement is such that the second extension tube 92 opens into the device at a position below the surface level of beverage held within the device.

Once the pressure inside the can and the device has initially stabilised further pressure fluctuation can occur, for example during storage, due to temperature changes. The gas inside the device will expand and contract accordingly but this process is reversible; gas is not displaced from the device as the first orifice 81 and the passageway 92 to the second orifice 84 are covered with liquid inside the device. Because of this, the device will always contain (until the can is opened) only the liquid that was forced into the device during initial pressure equalisation. This liquid also contributes to the stability of the device as it is retained within the boundary of a confining wall 100 provided as an integral part of the device. This also helps to maintain the centre of gravity of the device towards its base.

As shown in Fig.8, when the can is opened to atmosphere by pulling its ring pull (not shown) the pressure of the headspace above the beverage in the can reduces rapidly to atmospheric pressure. The pressurised gas within the device forces the liquid held within the device upwardly through the passageway 92 towards the second orifice 84 and also force a small amount of liquid out of the device through the first orifice 84.

Referring to Fig. 9, once the liquid level inside the device drops below the end of the first tube 89 liquid trapped in the second tube 92 continues to be pushed up this tube but gas is forced preferentially through the first orifice 81 into the body of the beverage 86 to produce the desired effect. This process takes only a fraction of a second due to the tiny amount of beverage that originally enters the device. All of the excess pressure within the device is vented during firing and very little beverage is retained in the device after firing.

In a further embodiment (not shown) the device is provided without a first tube 89 so that the first orifice 81 opens directly into the inside of the device.

Fig. 10 shows a retainer 121 attached to a device 120 to stabilise the device in the can and prevent it from making excessive noise when bumping into the can wall. The retainer 121 comprises a skirt or "saturn ring" around the device 120 to limit the extent of movement of the device 120 within its container. As shown in the plan view of Fig.11 the retainer 121 is attached to the device 120 by means of a plurality of arms 122. The arms and the retainer are formed as an integral moulded part of the device; when the device is provided in two parts the retainer can be provided on either of the parts.

Fig.12 and Fig.13 show an alternative retainer comprising a pair of wings which extend outwardly from a body of the device 130. The wings are provided with orifices 133 therein and extend only partially around the periphery of the device 130.

The retainer may be adapted to contact the inside surface of the container to hold the device within the container. Preferably, however, the retainer does not fix the device within the can but simply reduces rattle; the retainer may be arranged to allow the device to turn itself over within the can so that it assumes its correct orientation.

In a further alternative, the device may be made of soft plastics material or have soft plastics portions to reduce the noise of collision of the device with the inside of the container. In this case, the material or a portion of material is arranged to be rigid enough to hold the two parts of the device together by means of a snap fit when the device is provided in this form.

Fig.14 shows an alternative form for a device 140 in which the device is substantially cylindrical and is adapted to be arranged such that the length of the cylinder lies across the width of the container. The device is arranged such that the cylinder is substantially as wide as the container so as to limit the amount of movement of the device 140 within the container, for example, when the container is shaken.

Claims

A device (10, 60, 80) consisting of only two components for inclusion in a pressured beverage container (25) for jetting gas into the beverage (26, 86) upon opening the container (25), the two components being joined together to define an internal chamber (29), spaced first and second permanently open orifices (21, 71, 81, 24, 74, 84), the internal chamber (29, 66) being adapted to contain pressurised gas and a quantity of liquid (26, 86) such that the second orifice is located above, and the first orifice below, the level of liquid in the device prior to firing of the device (10, 60, 80) when the container (25) is opened, and the second orifice (24, 74, 84) communicates with the internal chamber (29, 66) through a standpipe (23, 72, 92) which, immediately prior to firing of the device (10, 60, 80) opens into the internal chamber (29, 66) below the surface level of the liquid (26, 86) held within the device (10, 60, 80) and in which, upon firing, liquid from within the device (10, 60, 80) is forced towards the second orifice (24, 74, 84) such that the pressurised gas from the internal chamber (29, 66) is expelled preferentially through the first orifice (21, 71, 81) into the beverage (26, 86)
A device (10, 60, 80) in accordance with claim 1 in which the first orifice (21, 71, 81) communicates with the internal chamber (29, 66) through a standpipe (20, 69, 89) adapted to limit the amount of liquid expelled through the first orifice (21, 71, 81) upon firing prior to gas being expelled through the first orifice (21, 71, 81).
A device (10, 60, 80) in accordance with claim 2 in which the standpipes (20, 69, 89, 23, 72, 92) are substantially co-linear.
A device (10) in accordance with any preceding claim in which the device (10) is reversible so that the first and second orifices (21, 24) are interchangeable in function.
A pressurised beverage container (25) containing a device (10, 60, 80) in accordance with any preceding claim.
A pressurised beverage container (25) having therein a device (10, 60, 80) for releasing pressurised gas into liquid contents of the container (25) when the container (25) is opened to the atmosphere, the device (10, 60, 80) consisting of only two components joined together to define an internal chamber (29, 66) containing a liquid (26, 86) and a gas at a pressure greater than atmospheric pressure, the device having a first orifice (21, 71, 81) opening into the beverage (26, 86) held within the container (25), and a second orifice (24, 74, 84) opening into a gas filled head space of the container and in which the second orifice (24, 74, 84) opens into a passageway (23, 72, 92), the passageway (23, 72, 92) providing communication between the second orifice (24, 74, 84) and a position in the internal chamber (29, 66) below the surface level of the liquid (26, 86) held therein.
A pressurised container (25) in accordance with claim 6 in which the device (10, 60, 80) is disposed in the container (25) to extend partially within the liquid (26, 86) and partially in a gas filled head space (28) above the liquid (26, 86) when the container (25) is in its normal attitude for opening.
A pressurised container (25) in accordance with any preceding claim, in which the liquid (26, 86) within the internal chamber (29, 66) of the device is beverage which has been transferred to the internal chamber (29, 66) from the container (25).
A method of generating a dispersion of bubbles within a beverage comprising the steps of:

a) providing a device (10, 60, 80) consisting of only two components within a sealed, pressurised beverage container (25) containing a liquid (26, 86), the two components being joined together to define an internal chamber (29,66) provided with spaced first and second permanently open orifices (21, 71, 81, 24, 74, 84;

b) arranging for the internal chamber (29, 66) of the device (10, 60, 80) to contain pressurised gas and a quantity of liquid immediately prior to opening the container (25), the first orifice being located below the level of liquid in the device and the second orifice being located above the liquid in the device;

c) and the device (10, 60, 80) is disposed in the container (25) to extend partially within the liquid (26, 86) and partially in a gas filled head space (28) above the liquid (26, 86) and the second orifice is located above the liquid (26, 86) in the container (25) when the container (25) is in its normal attitude for opening and further providing a passageway (23, 72, 92) extending from the second orifice to a point below the level of liquid in the device and arranging that, upon opening of the container (25), a quantity of the liquid held within the device (10, 60, 80) is moved by the pressurised gas along the passageway (23, 72, 92) to contact the second orifice (24, 74, 84) so that pressurised gas from the internal chamber (29, 66) is jetted preferentially from the internal chamber (29, 66) through the first orifice (21, 71,81) into the beverage in the container (25).