WO1998030848A1

WO1998030848A1 - Apparatus for chilling fluids

Info

Publication number: WO1998030848A1
Application number: PCT/GB1997/000044
Authority: WO
Inventors: Michael Ernest Garrett; Evelyn Arthur Shervigton
Original assignee: The Boc Group Plc
Priority date: 1997-01-08
Filing date: 1997-01-08
Publication date: 1998-07-16

Abstract

A chiller (10) for chilling a quantity of fluid comprising an adsorbent (12) for receiving and adsorbing under pressure a quantity of gas and in which the desorption of gas from the adsorption causes a reduction in temperature of the adsorbent (12) and adsorbate which acts to chill the fluid. The chiller (10) may comprise a thin-walled vessel (14, 14a) for placement in direct thermal contact with the fluid to be chilled and wherein the vessel (14a) comprises two thin sheets (95) of substantially similar size and shape, joined together around the peripheral edges (96) thereof so as to form a cavity therebetween for containing the adsorbent (12). The chiller (10) is suitable for chilling a canned or bottled beverage, and the can (26) or bottle may be provided with means to give a visual indication of the temperature of the beverage.

Description

APPARATUS FOR CHILLING FLUIDS

The present invention relates to an apparatus for chilling fluids and relates particularly, but not exclusively, to an apparatus for chilling canned or bottled beverages.

Canned or bottled beverages such as beer are often consumed where pre-refrigeration is unavailable. This is believed to have a detrimental effect on the product and, hence, several methods of chilling are known. These methods include the method of releasing a quantity of liquid compressed butane to atmosphere or using a cold crystallisation technique. However, these methods are environmentally unfriendly, costly in materials and have not gained widespread use. Major manufacturers are still seeking a method which avoids the disadvantages associated with these methods.

It is an object of the present invention to provide a chiller for chilling the canned or bottled beverages which reduces and possibly eliminates the problems associated with the above-mentioned methods.

Accordingly, the present invention provides a chiller for chilling a quantity of fluid, said chiller comprising an adsorbent, for receiving and adsorbing under pressure a quantity of gas; sealing means, for sealing adsorbed gas in said adsorbent; releasing means, for releasing adsorbed gas from said adsorbent in a controlled manner such that the action of desorption causes a reduction in the temperature of the adsorbent and adsorbate which acts to chill the fluid.

Advantageously, the adsorbent comprises activated carbon and is preferably selected from a group comprising: zeolites, cation exchanged zeolites, silica gel, activated carbons and carbon molecular sieve. Preferably, the chiller also includes carbon dioxide when adsorbed by said adsorbent.

Preferably, the chiller further includes an elongate tube in fluid connection at one end with the adsorbent and at its other end with the sealing means, thereby to define a passageway through which adsorbed gas passes as it is released from the adsorbent.

The chiller may be shaped to fit either around a fluid storing vessel so as to exchange heat therewith or to fit within the vessel; alternatively the chiller may at least in part form the fluid storing vessel.

In embodiments where the chiller fits within the fluid storing vessel, the elongate tube may comprise a spiral tube for fitment around an outer surface of a fluid storing vessel, thereby to facilitate heat transfer between the tube and the vessel and hence chill any fluid therein.

The releasing means may comprise means for obturating an outlet of a fluid storing vessel which when operated to open said vessel also acts to disengage the sealing means and release the adsorbed gas to atmosphere. Alternatively, the releasing means comprises means for obturating an outlet from said vessel which when operated to open said outlet acts to release adsorbed gas only. However, the releasing means preferably comprises a frangible portion breakable upon opening of said vessel. Conveniently, this frangible portion comprises a plug inserted into the end of the tube and secured to the obturating means such that opening said vessel acts to remove the plug from said tube, thereby releasing the adsorbed gas. Advantageously, the tube is positioned for directing escaping gas across the surface of any fluid within the vessel prior to said gas exiting the outlet. The chiller preferably includes control means for controlling the rate of desorption of the adsorbed gas, thereby to control the rate of cooling.

Conveniently the vessel may comprise a beverage container, such as a bottle or can. There is a requirement for a chilling apparatus for chilling canned or bottled beverages which necessitates no more than minimal changes to existing beverage containers. Major manufacturers also require a chilling apparatus which does not necessitate major changes to existing production lines.

To address these requirements, the chiller preferably comprises at least one thin-walled vessel for placement in direct thermal contact with the fluid to be chilled and wherein the or each vessel comprises two thin sheets of substantially similar size and shape, joined together around the peripheral edges thereof so as to form a cavity therebetween for containing the adsorbent.

Such an arrangement is easily introduced into beverage containers without requiring the design of those containers or of the production lines therefor to be changed substantially. Such chillers are also simple, inexpensive and easy to fabricate. In addition, such chiller vessels have a large surface area in relation to their volume, and this optimises their chilling efficiency in relation to their volume.

Consequently, the volume of such a chiller vessel can be minimised, so that it does not displace any greater volume of beverage than is strictly necessary to achieve the desired chilling effect.

Advantageously, the sheets, which may be planar, are resiliently deformable, in order that the chiller vessel can be inserted through the neck of a bottle or the dispensing aperture of a beverage can. The sheets may suitably be made of aluminium or an alloy thereof, which sheets can be easily welded together along their peripheral edges.

The sheets forming the chiller vessel may also be joined together, by spot welding, for example, at one or more points other than around their peripheral edges. Such an arrangement provides not only a stronger chiller vessel construction but also an increase in surface area. Moreover, these additional joining points may be aligned so as to form crease lines about which the chiller vessel may be folded, so as to facilitate insertion of the apparatus into a beverage container.

Preferably, the chiller comprises one or more elongate tubes, the or each tube communicating at one end with the vessel cavity and the adsorbent therein, thereby to create a passageway for adsorbed gas to pass through as it is released from the adsorbent. The or each elongate tube allows heat transfer from the beverage or other fluid to the gas flowing along its length, which is suitably substantially longer than the maximum dimension of the vessel; this latter feature enables the elongate tube(s) to be wound around a resiliently deformable vessel so as to hold it in a tightly-squeezed configuration for easy insertion into a beverage container, and/or to be disposed in the container so as to pass from the distal part thereof (ie from the point furthest from the dispensing aperture) to the dispensing aperture, thus passing through, and chilling, a significant proportion of the fluid therein.

To maximise the chilling effect, thermally-conductive fins may be provided, extending from one or both of the sheets forming the chiller vessel.

The present invention also encompasses a fluid storage vessel when provided with a chiller as described above. In some cases effective chilling of a fluid may take some time; where a canned beverage is to be chilled, for example, complete chilling thereof might take 30 seconds or more, which time is appreciable to a thirsty person. Such an individual would be grateful to know when the beverage is chilled to its optimum extent for consuming.

Accordingly, a beverage container comprising a chiller as described above may also be provided with temperature reactive means adapted to give a visual indication of the temperature of the beverage.

Advantageously the temperature reactive means comprises a thermochromatic substance, such as a thermochromatic paint, or pigment, or thermochromatic liquid crystals, substances which would change colour according to their temperature and which, per se, are known in the art. Preferably, the thermochromatic substance would be in direct thermal contact with the beverage container, such that as the temperature of the beverage fell due to the operation of the chiller so would the temperature of the container and the thermochromatic substance, which substance then changes colour thus giving the consumer a visual indication that the beverage had been chilled and was ready to drink.

The thermochromatic substance is preferably applied directly to the outer surface of the beverage container, not only so as more quickly and accurately to indicate any temperature change of the beverage therein but also so as to be more easily incorporated during the container manufacturing process. Drink cans, for example, are ordinarily painted, and the addition of a further station to apply thermochromatic paint or the like would be neither difficult nor expensive.

The thermochromatic substances could be applied in patterns and colours to provide a significant aesthetic appeal to a consumer; so as to produce an eye-catching design or slogan, for example, when the beverage or other fluid is sufficiently chilled.

For the avoidance of doubt, although this invention has been described in relation to fluids such as canned or bottled beverages, it is not limited thereto. The principles of this invention may be applied to materials other than fluids, such as solid or semi-solid foodstuffs, pharmaceuticals, chemicals or the like; the word "fluid" as used in the Claims should therefore be construed accordingly. In addition, it is believed that many of the features of the specific embodiments of apparatus in accordance with the present invention would be as applicable for the purpose of providing heat as they are for chilling substances.

The present invention will now be more particularly described by way of example only with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional view of a beverage can incorporating or forming part of the present invention;

Figures 2 and 4 are exploded cross-sectional views of the lid portion of Figure 1 and illustrate the "closed" and "opened" positions respectively.

Figures 3 and 5 are cross-sectional views taken in the direction of arrows A-A and B-B of Figures 2 and 4 respectively;

Figure 6 is a cross-sectional view of the present invention when used in conjunction with a screw top vessel;

Figure 7 is a cross-sectional view of a simplified form of the present invention;

Figures 8 to 11 are cross-sectional views of alternative forms of the present invention;

Figures 12 and 12a are diagrammatic front and side elevation views, respectively, of one embodiment of a chiller vessel forming part of the present invention; and Figure 13 is a diagrammatic view of an alternative embodiment of a chiller vessel.

Referring to Figures 1 to 5, a chiller 10 according to one aspect of the present invention comprises a quantity of adsorbent 12 encased in a sealed housing 14 having a sealing means in the form of, for example, plug 16 (Figure 2) which, in use, acts to obturate an outlet 18 thereby preventing leakage of gas adsorbed into said adsorbate. Preferably, the chiller includes an elongate tube 20 in fluid connection at one end 20a with the adsorbate and at its other end 20b with the sealing means in a manner which will be described in detail later herein. In the Figure 1 embodiment the adsorbent 12 is in the form of a disk which, in operation, sits on the base 22 of a vessel 24 into which it has been placed and the tube spirals upwardly towards an outlet 26 and thus passes through the interior of vessel 24 thereby facilitating efficient chilling the contents thereof in a manner to be described in detail later herein.

The adsorbent 12 may comprise any one of a number of adsorbents such as, for example, zeolites, cation exchanged zeolites, silica gel, activated carbons and carbon molecular sieve but preferably comprises activated carbon of the type sold under the trade mark "AMBERSORB". Such adsorbents are capable of adsorbing under pressure a significant quantity of gas for later release. Gas adsorbed in this manner will, when released to atmospheric pressure, experience a significant drop in temperature and may thus be used to chill the contents of any fluid in which the chiller 10 is situated. In particular, activated carbons can hold very large quantities of C0₂, with one gramme of carbon being capable of holding as much as 0.4 grammes of carbon dioxide at 10 bar. Typically, a cooling capability approximating to 15Kcal/mole C0₂ is available when pressurised to 10 bar and a beer can containing 300ml of liquid would require above 6Kcal to chill it through 20 degrees. Forty-four grammes of carbon occupying a volume of about 100ml would be sufficient to cool an individual can to the required temperature. In operation, the adsorbent is exposed to, for example, C0₂ at between 6 to 10 bar and preferably between 6 to 8 such that the C0₂ is adsorbed and, if necessary, is then sealed therein by blocking outlet 18 with plug 16. A chiller may be inserted into the vessel 24 before a lid portion or cap 25 is used to seal the vessel. A suitably shaped chiller 10 may be inserted through the outlet itself. Such an alternative is perfectly feasible when the chiller 10 is intended for use in bottles having large diameter screw tops and the like, as shown in Figure 6. The Figure 1 to 5 embodiments illustrate the present invention in relation to a beverage can 26 having a ring-pull opening best seen in Figures 2 to 5. Such cans are generally made in two parts comprising a base portion 28 and a top 30 having a ring-pull 32 and opening 36 provided therein. The ring-pull and opening arrangement forms no part of the present invention itself and is therefore not described in detail herein. However, it will be appreciated that a number of variations of the ring-pull are available and hence the present invention should not be considered to be limited to use in connection with the ring-pull described and illustrated herein. Such ring-pulls include the type having a finger engageable portion 36 which, when actuated, pivots about a fixed point at which it is attached to the lid so as to force a frangible portion 38 downwardly and into the can, thus opening the can and allowing the contents to be poured out for subsequent consumption. The frangible portion 38 includes an edge 38a which remains attached to the rest of the lid, thus preventing portion 38 falling into the interior of the can. Once actuated, the frangible portion 38 remains bent downwardly ( as shown in Figure 5) whilst the ring-pull itself 32 may be returned to a position in which it lies flat with the surface of the lid (as shown in Figure 3).

In one embodiment of the present invention, the opening of the can is used to cause plug 16 to be removed from the end of tube 20 and thus allow the adsorbed gas to escape to atmosphere, this arrangement is best seen with reference to Figures 2 to 5 from which it will be seen that plug 16 includes a pivotable portion 40 which is hinged at point 42 to body portion 44 adhesively bonded to the lid. Pivotable portion 40 is positioned immediately beneath the outlet 26 and is shaped in complementary fashion. The outlet end 20b of tube 20 terminates within the body portion 42 such that, then in a closed position, plug 16 acts to obturate the outlet and thus prevent any gas escaping from the adsorbent. Advantageously, the plug 16 pivotable portion 40 and body portion 44 are all made of deformable plastic, thereby allowing the plug to be engageable in a "snap-fit" manner. As shown, the plug 16 preferably comprises a detent on an edge face 40a of pivotable portion 40 which may be pushed between its open and closed positions (Figures 5 and 3 respectively). In operation, the adsorbed gas is sealed in by pushing pivotable portion 40 in the direction of arrow C in Figure 5 thus causing plug 16 to "snap-fit" into outlet 18 as shown in Figures 2 and 3. Once closed, the chiller 10 may be inserted into the can at the same time as the lid is placed thereon and joined thereto by swaging the mating edges 48, 50 (Figure 1) of the base and lid respectively. Such a joining operation is undertaken after the can has been filled with beverage 8 and is thus the last of a number of production steps.

The can is opened in the conventional manner by pulling ring-pull 36 upwardly in the direction of arrow U and thus causing the other end thereof 36a to engage with frangible portion 38 and push it downwardly into the can. As frangible portion 38 is bent downwardly it engages an upper surface 40b of pivotable portion 40 and thus pushes it downwardly causing plug 16 to disengage the outlet 26. Once the outlet is clear, adsorbed gas will be desorbed from adsorbent 12 and pass upwardly through tube 20, cooling the contents of the can as it goes. Escaping gas may be directed across the upper surface of any beverage in the can thus cooling it even further before escaping from the can via outlet 18. Once the contents of the an have been sufficiently chilled, the contents may be dispensed in the usual manner. The rate of desorption may be controlled by optional restrictor 52 placed in tube 20 or by modifying the tube diameter to suit the particular rate required. In some arrangements, the can is pressurised with an inert gas which effectively acts to strengthen the can, thus preventing the sidewalls buckling when subjected to large vertical loads. The pressurising gas comprises, for example, nitrogen which also acts to fill the head space in the can and thus prevent oxidation taking place. If the pressure of the can head is sufficiently high, eg 5-10 bara then the adsorbed C0₂ will not need to be sealed into the adsorbent and hence the elaborate plug and tube arrangements of Figures 2 to 5 may be dispensed with. In this alternative arrangement (Figure 7), the outlet end 20b of tube 20 is just positioned towards outlet 18 and the ring-pull itself 32 performs the same function as plug 16 thereby to allow adsorbed gas to be desorbed and passed to atmosphere once the can is opened and depressurised to atmospheric pressure.

In some situations it may be convenient to chill the outside of the container and hence the arrangement illustrated in Figure 8 may be employed to good effect, this arrangement is very similar to that described above save for the fact that the adsorbent 12 and spiral tube 20 are shaped and positioned such that they are in fairly intimate contact with the outer surface 24a of can 24. Obviously, one may employ a very simple plug arrangement 16 which may be pulled in the direction of arrow P out of engagement with the outlet end 20b of tube 20, thus releasing the adsorbed gas and causing any chilling effect to be passed through the can wall in the direction of arrows R thereby to chill the contents of the can as described above. Such an arrangement may be provided as a one off disposable chiller or may be of the rechargeable kind in which case a somewhat more robust construction can be justified. In either arrangement the chiller 10 may be surrounded by an insulating jacket 56 which effectively acts to protect the user from the extreme chilling effect and ensure that the contents of the can is chilled rather than the air surrounding it. The outer surface 56a of jacket 56 provides a suitable surface for advertising matter.

Two further alternatives are illustrated in Figures 9 and 10. In the Figure 9 embodiment the outlet end of tube 20 terminates in an "O-ring" plug 60 having plug 16 located therein. The "O-ring" 60 is suitably sealed against the can wall 24 and the tube 20 so as to present any leakage. Other alternatives will however present themselves to a person skilled in the art. Operation of this embodiment is similar to that described above save for the fact that one may remove the plug 16 without having to open the can, thereby cooling the content of the can before dispensing. Such an arrangement would be well suited for use in beer cans employing the well known "draught" systems.

Figure 10 illustrates a still further embodiment in which the can 26 is provided with a longitudinally extending recess 70 formed by deforming the base 22 during the forming process. This recess 70 is used to have a self contained chiller 10a in many ways similar to that described above but modified somewhat to suit the particular application. In particular, the chiller 10a comprises, for example, an outer casing 14a housing the adsorbent 12a and having at an upper end 72 an outlet 74 for allowing adsorbed gas to be desorbed into a head-space 76 formed above the chiller itself. The outer surface 78 of casing 14a is formed in a turned manner so as to produce or a plurality of spiral passages 80 extending between the headspace end and the base end. The diameter of the outer surface 78 is selected such that, once inserted, the chiller 10 is a close fit up against the wall portion 90 forming recess 70 thus making passages 80 into closed passages bounded by wall portion 90. A plunger 80, rod 82 and plug 84 arrangement are provided in linked manner through a central passageway 86 formed through adsorbent 12a. In its inactivated position, plunger 80 protrudes beyond the base 10c of the chiller and acts to cause plug 84 to seal outlet 74. Further features of this arrangement include a latching arrangement in the form of indent 91 and detent 92 on the can and chiller 10a respectively. Once inserted, this latch acts to secure chiller 10a in recess 70 and prevents the chiller being inadvertently removed during chilling.

Operation of the Figure 10 embodiment involves insertion of the chiller 10a into recess 70 and depression of plunger 80 to position 80a such that plug 82 is driven from outlet 74 and adsorbed gas is desorbed into head-space 76. The close fit of the spiral passages 80 up against the recess wall 90 acts to define a region of good thermal conductivity thus allowing escaping gas to chill the contents of the can through wall portion 90. Chilled beverage will tend to move away from wall portion 90 and is replaced by relatively warm beverage for subsequent chilling. Clearly, this arrangement has the advantage of providing the user with a chiller 10a which need only be used when it is not possible to chill the beverage by more conventional means or when one simply desires to provide additional chilling.

Figure 11 illustrates yet another embodiment, in which the chiller 10b forms a part of the can 26 and is integral therewith.

The chillers 10 shown in Figures 12 and 13, comprise thin-walled vessels 14a which are for installation inside a fluid storage container (not shown) and in direct thermal contact with the fluid to be chilled, and are formed of two thin rectangular sheets 95 of aluminium or aluminium alloy which are welded together along their peripheral edges 96. In addition, spot welds 97 are provided, joining the two sheets 95 together to create a "mattress" type configuration. This type of construction not only strengthens the vessel 94 but also provides an increase in surface area in the area adjacent each spot weld 97.

The configuration of the vessels 14a shown in Figures 12 and 13 advantageously combines a large surface area with the minimum volume required to contain sufficient adsorbent to give the desired chilling effect and freely to permit cooling gas adsorption and desorption. Minimising the volume of the vessel 14a is important, so as not to displace too much fluid from the storage container within which it is to be placed. Maximising the surface area of the vessel 14a is important, so as to optimise chilling efficiency and to reduce the time taken to chill the fluid by the desired amount. Furthermore, increasing the surface area allows the vessel 14a to extend over as large a vertical distance as possible within the fluid storage container, so that when the fluid storage container is opened (which would normally then be in a position with the dispensing aperture uppermost), the downward current of fluid cooled by conduction from the upper portion of the vessel is maximised, ^■ thereby contributing to greater chilling efficiency.

The disposition of the spot welds 97 is such that they create crease lines C about which the vessel 14a can be folded, in Z-fold or concertina fashion for example, for ease of insertion of the vessel 14a into a fluid storage container (not shown), for example through the dispensing aperture thereof. The thin sheets 954 are sufficiently resilient as to tend to "open out" the folded vessel 14a after insertion, which improves the flow thereabouts of fluid to be chilled and can suffice to hold, or wedge, the chiller vessel 14a in position within the fluid storage container.

Along one edge 96 of the chiller vessel 14a are a number of outlets 98 connected to elongate tubes 20. Gas released from the adsorbent within the vessel 14a leaves the vessel 14a via the outlets 98 and passes through the elongate tubes 20, and as it does so, chills the fluid. The elongate tubes 20 terminate at or adjacent the dispensing aperture (not shown) of the fluid storage container, and open to atmosphere on opening of the container for dispensing.

The elongate tubes 20 are sufficiently long as to extend through a substantial part of the fluid in the storage container, so as to maximise the chilling effect of the desorbed gas passing therethrough. Preferably the elongate tubes 20 are sufficiently long as to permit the chiller vessel 14a to be installed in the storage container with the outlets 98 as far away from the container dispensing aperture (not shown) as possible, so that with the container positioned with its dispensing aperture uppermost the chiller 10 is in the lowermost portion of the container with the outlets 98 at its bottom. Advantageously, the elongate tubes 20 are also long enough to be wrapped around the chiller vessel 14a, thus temporarily holding the creased or folded vessel 14a tightly together as it is inserted within the storage container, whereafter the resilience of the thin sheets 95 acts so as to unfold or expand the vessel 14a, thus holding it in place in the storage container and/or preventing it undesirably from passing through and/or obstructing the dispensing aperture during the dispensing operation.

The vessels 14a shown in Figures 12 and 13 are equally applicable for use with canned or bottled beverages. The vessel 14a of Figure 12 would preferably be folded about the crease lines C running parallel to its shorter side, or curled up in a spiral about an axis parallel thereto, for insertion into a fluid storage container through the dispensing aperture thereof with the edge along which the outlets 98 are disposed foremost so that once installed that edge is most distant from the dispensing aperture. The vessel 14a of Figure 13 is preferably folded about the crease lines C, or curled up in a spiral about an axis, parallel to the longer side of the vessel 14a for insertion into a fluid storage container.

The chiller described above provides numerous advantages: it is simple and easy to manufacture. It is easily insertable into existing fluid storage containers, even through quite small apertures thereinto, and requires no changes to the designs of standard containers simply to permit insertion. Accordingly, the insertion of such chillers may be achieved without significant changes to existing production lines, at the point immediately prior to or immediately after the filling of the containers with fluid, for example, The shape and configuration of the chiller also ensures that it is quick and efficient in use.

Having described specific embodiments in accordance with the present invention, those skilled in the art will appreciate that the invention encompasses several variations thereof. For example, the thin sheets 95 need not be rectangular; they could instead by of any shape suitable to form any shape of vessel as appropriate for a particular application. The thin sheets could therefore be circular, cylindrical or any other shape. The present invention is not restricted to chillers comprising planar sheets 95 as drawn, and the word "sheets" should be construed accordingly. The number and disposition of outlets 98 need not be as shown in the drawings, since in some applications it may be desirable to provide only a single outlet and to provide a slow chill, as opposed to the faster chill allowed by multiple outlets, for example. The thin sheets 95, although conveniently of aluminium or aluminium alloy, may be formed of other materials and, as stated earlier, the present invention is particularly suited to cooling canned or bottled beverages but is not limited thereto. Thus, not only is the chiller of the present invention capable of chilling fluids other than beverages, and indeed substances other than fluid (solid or semi-solid foodstuffs, for example), it is also suitable with minimal modification for providing a heating effect (as those skilled in the art will readily appreciate).

Any beverage or other container comprising apparatus in accordance with the present invention may also be provided with a thermochromatic indicator (not shown) to give a visual indication as to when the chilling operation has been completed; in the case of a thermochromatic paint or pigment this can be applied, as a simple additional step, in the manufacturing process, in patterns and colours so as to give the container aesthetic appeal to a consumer or potential consumer.

Claims

1. A chiller for chilling a quantity of fluid, said chiller being characterised by an adsorbent, for receiving and adsorbing under pressure a quantity of gas; sealing means, for sealing adsorbed gas in said adsorbent and releasing means, for releasing adsorbed gas from said adsorbent in a controlled manner such that the action of desorption causes a reduction in the temperature of the adsorbent and adsorbate which acts to chill the fluid.

2. A chiller as claimed in Claim 1 characterised in that said adsorbent comprises activated carbon.

3. A chiller as claimed in Claim 1 characterised in that said adsorbent is selected from a group comprising: zeolites, cation exchanged zeolites, silica gel, activated carbons and carbon molecular sieve.

4. A chiller as claimed in any one of Claims 1 to 3 characterised in that the chiller further includes carbon dioxide when adsorbed by said adsorbent.

5. A chiller as claimed in any one of Claims 1 to 4 characterised by an elongate tube in fluid connection at one end with the adsorbate and at its other end with the sealing means, thereby to define a passageway through which adsorbed gas passes as it is released from the adsorbent.

6. A chiller as claimed in any one of Claims 1 to 5 characterised in that said chiller is shaped to fit around and exchange heat with a fluid storing vessel.

7. A chiller as claimed in Claim 6 when dependent upon Claim 5 characterised in that the elongate tube comprises a spiral tube for fitment around an outer surface of a fluid storing vessel, thereby to facilitate heat transfer between the tube and the vessel and hence chill any fluid therein.

8. A chiller as claimed in any one of Claims 1 to 5 characterised in that said chiller is shaped to fit within a fluid storing vessel and said elongate tube extends within the vessel thereby to contact any fluid within the vessel.

9. A chiller as claimed in Claim 8, comprising at least one thin-walled chiller vessel for placement in direct thermal contact with the fluid to be chilled and wherein the or each chiller vessel comprises two thin sheets of substantially similar size and shape, joined together around the peripheral edges thereof so as to form a cavity therebetween for containing the adsorbent.

10. A chiller as claimed in Claim 9 wherein the sheets are planar.

11. A chiller as claimed in Claim 9 or Claim 10 wherein the sheets are resiliently deformable.

12. A chiller as claimed in any one of Claims 9 to 11 wherein the sheets are made of aluminium or an alloy thereof.

13. A chiller as claimed in Claim 12 wherein the sheets are welded together along the peripheral edges thereof.

14. A chiller as claimed in any one of Claims 9 to 13 wherein the sheets are additionally joined together at one or more points other than around the peripheral edges thereof.

15. A chiller as claimed in Claim 14 wherein the said points are aligned so as to form crease lines about which the vessel may be folded.

16. A chiller as claimed in any one of Claims 9 to 15 comprising one or more elongate tubes, the or each tube communicating at one end with the chiller vessel cavity and the adsorbent therein, thereby to create a passageway for adsorbed gas to pass through as it is released from the adsorbent.

17. A chiller as claimed in Claim 16 wherein the or each elongate tube is substantially longer than the maximum dimension of the chiller vessel.

18. A chiller as claimed in any one of Claims 9 to 17 comprising one or more thermally-conductive fins extending outwardly from at least one of the sheets.

19. A chiller as claimed in any preceding Claim characterised in that the releasing means comprises means for obturating an outlet of a fluid storing vessel which when operated to open said vessel also acts to disengage the sealing means and release the adsorbed gas to atmosphere.

20. A chiller as claimed in any one of claims 1 to 18 characterised in that the releasing means comprises means for obturating an outlet from said vessel which when operated to open said outlet acts to release adsorbed gas only.

21. A chiller as claimed in Claim 19 or Claim 20 in which said releasing means comprises a frangible portion breakable upon opening of said vessel.

22. A chiller as claimed in Claim 21 characterised in that said frangible portion comprises a plug inserted into the end of the tube and secured to the obturating means such that opening said vessel acts to remove the plug from said tube, thereby releasing the adsorbed gas.

23. A chiller as claimed in any one of Claims 8 to 22 characterised in that the tube is positioned for directing escaping gas across the surface of any fluid within the vessel prior to said gas exiting the outlet.

24. A chiller as claimed in any one of Claims 1 to 4 characterised in that said chiller comprises an unsetable chiller insertable into a walled recess formed in the vessel and having an outer surface comprising a plurality of spiral passages which in operation, act to define a gas flow path between the walls of the recess and the chiller itself.

25. A chiller as claimed in Claim 24 characterised in that the chiller further includes a plug at an upper end which is linked for operation to a plunger manually operable to cause the plug to be removed from an outlet thereby to cause adsorbed gas to be desorbed from said adsorbent and passed to said passages so as to cool the walls of the recess and hence the contents of the vessel.

26. A chiller as claimed in Claim 24 or Claim 25 characterised by a latching means for releasably securing the chiller in the recess.

27. A chiller as claimed in any one of Claims 1 to 26 characterised by control means for controlling the rate of desorption of the adsorbed gas, thereby to control the rate of cooling.

28. A chiller as claimed in any one of Claims 1 to 5 or any one of Claims 19 to 27 when dependent on any one of Claims 1 to 5 wherein the chiller forms an integral part of a fluid storage vessel.

29. A chiller substantially as hereinbefore described and with reference to the accompanying drawings.

30. A fluid storage vessel characterised by a chiller as claimed in any one of Claims 1 to 29.

31. A fluid storage vessel as claimed in Claim 30 comprising temperature reactive means adapted to give a visual indication of the temperature of the fluid.

32. A fluid storage vessel as claimed in Claim 31 wherein the reactive means comprises thermochromatic paint or pigment.

33. A fluid storage vessel as claimed in Claim 31 wherein the reactive means comprises a thermochromatic liquid crystal device or layer.

34. A fluid storage vessel as claimed in Claim, 30 or Claim 31 or Claim 32 wherein the reactive means is applied to the outer surface of the fluid storage vessel.