Apparatus for chilling fluids

Abstract: A chiller (10) for chilling a quantity of fluid (8) comprises an adsorbent (12) for receiving and adsorbing under pressure a quantity of gas; sealing means (16), 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 (8).

Description: 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. For example, a beverage chiller known from US-A-3 553 976 includes the method of expanding compressed Freon 12. 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. In one possible arrangement, the chiller is shaped to fit around and exchange heat with a fluid storing vessel. Advantageously, 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. Alternatively, the 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. Conveniently, 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. 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. Preferably, the releasing means comprises a frangible portion breakable upon opening of said vessel. Conveniently, 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. 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. Preferably, the chiller includes control means for controlling the rate of desorption of the adsorbed gas, thereby to control the rate of cooling. The present invention also encompasses a fluid storage vessel when provided with a chiller as described above. Conveniently the vessel may comprise a beverage can. 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 10 are cross-sectional views of alternative forms of the present invention. 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 CO 2 , 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 CO 2 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, CO 2 at between 6 to 10 bar and preferably between 6 to 8 such that the CO 2 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 44 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 can 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 CO 2 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 prevent 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 suite 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 81 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 81 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, 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 81 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 are simply desires to provide additional chilling.

Claims: 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. A chiller as claimed in Claim 1 characterised in that said adsorbent comprises activated carbon. 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. 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. 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. 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. 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. 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. A chiller as claimed in any one of Claims 1 to 8 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. A chiller as claimed in any one of claims 1 to 8 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. A chiller as claimed in Claim 8 in which said releasing means comprises a frangible portion breakable upon opening of said vessel. A chiller as claimed in Claim 11 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. A chiller as claimed in any one of Claims 8, 9, 11 and 12 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. 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 78 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. A chiller as claimed in Claim 14 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. A chiller as claimed in Claim 15 or 16 characterised by a latching means for releasably securing the chiller in the recess. A chiller as claimed in any one of Claims 1 to 16 characterised by control means for controlling the rate of desorption of the adsorbed gas. thereby to control the rate of cooling. A fluid storage vessel characterised by a chiller as claimed in any one of Claims 1 to 17.

Inventors: GARRETT MICHAEL ERNEST, GARRETT, MICHAEL ERNEST
Applicants: BOC GROUP PLC, THE BOC GROUP PLC
Application year: 1996
Main classification: F25D9
IPC codes: F25B17, F25D31, F25D5