DISPOSABLE SELF-COOLING DEVICE

Abstract: An improved disposable self-cooling device for chilling confined volumes, especially canned beverages, containing a liquid or liquified refrigerant under pressure, and an evaporator unit as a heat exchanger system, both of them surrounded by the confined volume, preferably beverage to be chilled. Upon initiation the cooling process, the beverage cools down to the required, wanted temperature and it is ready for consumption within a short period of time. Low cost of manufacture, utilization of previously involved techniques and health care instructions are favourably supported by the invention.

Description: Disposable Self-cooling Device Technical ffield The present invention relates to disposable self- cooling devices, more particularly to an improved device of the kind concerned for single time chilling of confined volumes, especially of canned beverages. Such devices generally comprise a receptacle that is filled with a liquid or liquified refrigerant, an evaporator unit that is in good heat-exchanging relationship with the volume, i.e. with the beverage to be chilled, and at least a valve means by which, to initiate the cooling process, the liquid refrigerant can be allowed to evaporate whereby heat required for said evaporation is extracted, at least partially, from the volume to be chilled. Background Art Apparatus for chilling small bounded volumes, especially small cans containing beverages immediately before use are described in various patents. In the present summary we restrict ourselves to the discussion of prior art methods, where the refrigerant applied is a liquid, since the evaporation heat that is utilized for cooling is much larger than the heat which is gainable by mere expansion. One group of these known earlier inventions is based on the provision of devices where the cooling material i.e. the refrigerant is stored and/or activated outside or around the beverage to be chilled. Such solutions are disclosed, among others, in U.S. Pat. No. 3,553 . 976 to Cumine et al., U.S. Pat. No. 3,842,617 to Chase et al., U.S. Pat. No. 3,987,643 to Willis and U.S. Pat. No. 4,0 ,03 to Yόder. Some of these devices contain separated containers for.the refrigerant, and connecting means to the volume to be cooled. This counteracts portability and disposability, and the simple handling of the whole device as well. With other known devices of the type mentioned the evaporating refrigerant surrounds the beverage to be cooled and thus, the heat required for evaporation is extracted from the volume to be chilled to a certain limited extent only. Por geometrical reasons mainly, a greater amount of heat required for evaporation is taken from the surrounding atmosphere whereby efficiency and economics of the process are negatively affected through obvious losses. Another group of the related prior art inventions known until now are based on providing devices where the efficiency is increased by placing the container of the liquid refrigerant inside the volume, i.e. the beverage to be cooled. Thus, all the heat required for evaporation and/or expansion is extracted from the beverage to be chilled. Such relations appear e.g. in the U.S. Pat. No. 3,320,767 to halen, U.S. Pat. No. 3 . 417,573 to Warner, U.S. Pat. No. 3,494,141 to Irwin et al., U.S. Pat. No. 3,494,142 to Beck, U.S. Pat. No. 3,494,143 to Barnett et al., U.S. Pat. No. 3,696,633 to Hills, U.S. Pat. No. 3,726,106 to Jaeger, U.S. Pat. No. 3,852,975 and U.S. Pat. No. 3,919,856 to Beck. The process performed in devices of the above group can be sketched in the following way. Boiling at constant pressure usually results in that the temperature of a liquid reaches a certain temperature, namely the boiling point of the liquid at the given pressure. If pressure is constant, this temperature remains the same O P until the total liquid aov-ount evaporates. In the present case, the ambient temperature is approximately constant and boiling takes place by decreasing the initial high pressure in a steady way to the surrounding one atmosphere. If the process were an adiabatic one, the pressure would remain constant until the total amount of the liquid evaporates. However, the system is not an adiabatic one. By taking into account the second law of thermodynamics, and the finite heat capacity of both the liquid refrigerant and its container, the temperature of the volume of the beverage to be chilled surrounding the cooling system will decrease, simultaneously with decreasing pressure, This decreases the boiling point and increases the vaporization enthalpy, and thus, the cooling process is accelerated in principle. This is however, moderated by the limited rate of heat exchange. Because of the limited size of the heat exchange surfaces and the infeasible geometrical layout, this last mentioned effect causes considerable difficulties to a rapid cooling in any apparatus based on the above mentioned patents. In a third group of known prior art devices disclosed in a number of patents issued, e.g. in U.S. Pat. No. 3,309,890 to Barnett et al., U.S. Pat. ϋ_ 0 . 3,326,013 to Jacobs, U.S. Pat. N . 3,525,236 to Solkhah, U.S. Pat. No. 3,636,726 to Rosenfeld and U.S. Pat. N 0 . 3,579,060 to Chase, some of the above mentioned disadvantages and features are already, at least partially, eliminated and considered, respectively. Thus, the solutions disclosed in the specifications of Solhkhah and Chase (U.S. 3,525,236 and U.S. 3,759,060 respectively) show attempts towards an increase of the efficiency and tlii. rate of internal heat OMPI exchange * However, even said last mentioned prior art devices are not really avourable with respect of the above, and also their manufacture seems to be rather complicate, difficult and thus, disadvantageous * Disclosure of Invention An object of the present invention is to provide an improved disposable self-cooling device for chilling con¬ fined volumes, especially canned beverages, by which said drawbacks and disadvantages of the known prior art devices as per above, are fully eliminated. More pa ticularly, the object of the present invention lies in the provision of a device of " improved internal heat exchange characteristics together with low cost of manufacture and thus, with improved economics. The above and other objects are achieved by the provision of a novel, improved device of the kind concerned wherein, in accordance with the basic features of the invention, the improvement consists in a cylinder capable of pertaining pressure and filled with a liquid or liquified refrigerant being arranged substantially in the very centre area of the confined volume to be chilled; in an evaporator unit having the shape of a coiled tubular conduit that is wound along a substantially circular, spiralling path within the volume to be chilled surrounding the above said cylinderj and in said evaporator unit being arranged in duly spaced relationship to both said cylinder and the preferably thin metal sheet can wall that defines the confined volume to be chilled. The device according to the present invention raises the efficiency because of the optimalization of the heat exchange conditions, and it is relatively simple to manufacture. Purtheron, it provides to take better into account the health and environmental conditions. of In preferred embodiments the device according to the present invention the evaporator unit comprises an aluminum or other metal pipe-coil, or prestamped compressed metal sheets forming a substantially tubular conduit for the augmented surface necessary for the effective process of evaporation. In a suitable embodiment a valve means to be set in action manually is inserted between one end of the conduit of evaporation, especially the pipe-coil and the cylinder of the refrigerant, and it is connected through a capillary bore to the conduit of evaporation, especially to the pipe-coil. The other , end of said conduit of evaporation, especially the pipe-coil having a free outlet orifice that opens into the ambient atmosphere, g<=>es hermetically through and is fixed to the top plate of the preferably thin metal sheet can defining the confined volume to be chilled. It has proved to be of advantage to insert a separator buffer box into said evaporator unit, especially in its conduit leading to said free orifice, for retaining all possibly liquid phases of the refrigerant within the system. Por simultaneous exploitation of all known mass production technology experiences and benefits of the field concerned it has been advantageous to build the devices according to the invention with a pressure-tight cylinder for the liquid refrigerant, similar to the widely used aerosol-receptacles equipped with a valve provided with a diving rod pipe separated by an interspace from the bottom of the container. OMPI Upon initiation of the process of chilling, in one preferred example of the device according to the invention the refrigerant is discharged into the pipe-coil in practically sprayed liquid condition and the boiling i.e. evaporation takes place in the pipe-coil itself. In consequence of the difference in the environmental conditions (temperature, pressure) sometimes it may occur that in the passage of evaporation, i.e. in the pipe-coil, the liquid refrigerant does not evaporate at due rate in its whole and thus, some of the refrigerant or at least some of its contaminantswould escape in liquid form to the ambient atmosphere. To prevent this, advantageously a separator buffer box as mentioned above is introduced in the evaporator passage, especially in the pipe-coil before its outlet orifice to_the ambient atmosphere, which retains all liquid phases eventually not evaporated of the evaporating refrigerant. A preferred embodiment of this separator buffer box is a substantially cylindrical metal box suitably arranged beneath and in axial alignment with the cylinder comprising the liquid refrigerant. Said separator buffer box may be equipped with a porous, fibrous or other hygroscopic inside lining or coating for improved function. A possible preferred embodiment of the invention may have a manually activated initiation means that may be hermetically led through the top (or bottom) plate of the can containing the beverage to be chilled. It is positively connected to the valve means of the cylinder comprising the liquid refrigerant. In a favourable embodiment of the invention the manually activated initiation organ consists of a threaded shaft that is engaged to an insert nut hermetically embedded in the lid of the can. It may act against a sleeve comprising an elbow bore extending between the valve means on the cylinder for the liquid refrigerant and the coil pipe, the elbow bore further containing a capillary tube the latter being connected to the pipe-coil of the evaporator unit via a flexible intermediate tube or coupling stud. A further embodiment satisfying the requirements of both simple mass production and increased hygienic safety at the same time,may be designed and laid out in a manner where the cylinder comprising the refrigerant, the valve means together with said actuating means for initiating the cooling process and the evaporator unit, especially the pipe-coil as well as the free outlet orifice for the evaporated gaseous refrigerant are formed and fastened to one end plate of the can, while the opening for the drain of the beverage, preferably in a form of a lift-ring type closure, a tap-top or a screw-cap, is arranged on the other, opposite lid or end plate of the can. With this embodiment, the evaporated gaseous refrigerant is discharged after initiation of the cooling process e.g. downwards, while the consumption, pouring out of the beverage may be performed through the upper lid. This may be essential for hygienic and palatableness reasons even in cases, when the refrigerant, although completely hermetically separated from the beverage to be chilled j is totally harmless for the health and satisfies all hygienic prescriptions for foods. Brief description of the drawings The essence of the present invention is shown more particularly by way of example only in the following description of a preferred embodiment of the portable disposable self-chilling device, with reference to the attached drawing figures that are as follows: Pig. 1 is a vertical cross sectional view of the device, Pig. 2 is a top plan view of the device, Pig. 3 is a cross sectional view of Pig. 1 taken along the line III-III, Pig. 4 is a cross sectional view of Pig. 1 taken along the line IV-IV. Detailed description of a preferred embodiment of the invention With reference to the attached drawings in which like reference numerals designate like or corrsponding parts throughout the various views. and with particular reference to Pig. 1 the beverage 2 to be cooled is contained in a thin metal sheet can 1. Coaxially with an axis X-X a cylinder 3 filled with suitably chosen liquid refrigerant 4 e.g. with liquid freon is arranged in the central area of the can 1. The cylinder 3 is of similar construction and of similar form to the cylindrical pressure-tight aerosol receptacles known per se. The cylinder 3 is equipped with a valve means 7 generally used at aerosol sprays, that is normally closed and opens by downward pressing. Valve means 7 is connected to a diving rod pipe 16 immersed in the liquid refrigerant 4 and having a bottom end that is separated by a span from the bottom of the cylinder 3» T e vapour pressure in the cylinder 3 above the liquid refrigerant 4 drives the liquid refrigerant 4 through the diving rod pipe 16 to the valve means 7 in a well known manner. The valve means 7 is upwards connected to a sleeve 9 provided with an elbow pipe ending in a capillary bore 14 leading to a flexible intermediate tube 15• A threaded shaft 8 engaged gastightly to a nut insert 19 that is hermetically sealed to a top plate 10 of the can 1 rests against the sleeve 9« in evaporator unit 5, here a pipe-coil consisting of a number of windings of a preferentially aluminum spiral tube constituting the evaporation conduit is connected, through the flexible intermediate tube 15 and through the capillary bore 14 and the valve means 7 to the cylinder 3 comprising the refrigerant. The pipe-coil extends downwards from the intermediate tube 15 in alignment with the cylindrical surface of both the cylinder 3 and the can 1 around the axis X-X with having a free distance to both the outer wall of the cylinder 3 comprising the refrigerant 4 and the inner wall of the can 1 containing the beverage 2. An end portion 6 of the pipe- coil forming the evaporator unit 5 is hermetically led through and secured to the top plate 10. An outlet orifice 17 of the end portion 6 of the pipe-coil communicates freely to the surrounding ambient atmosphere. Prior to the end portion 6 of the pipe-coil a separator buffer box 12 constituting a cylindrical metal box in alignment with the axis X-X and forming part of the evaporation conduit is arranged, the inner surface of which is overlayed by a porous, fibrous or other hygroscopic lining 13• The top plate 10 of the can 1 is provided by a weakened portion providing a lift-ring type closure 11 for discharging the beverage 2 for consumption as well known in the art concerned. The whole inner cooling system consisting of the cylinder 3, OMPI the sleeve 9, the intermediate tube 15, of the pipe-coil as evaporator unit 5 attached to the cylinder 3, further of the separator " bu fer box 12 is placed within the can 1, and it is fixed against vibration by means of a fixing means 18 that is rested on the top plate 10 and on the upper flange of the cylinder 3» The operation of the above described, only illustrative embodiment of the portable disposable self- cooling device according to the invention may be described as follows: In order to initiate the cooling of the liquid content, e.g. the beverage 2,the threaded shaft 8 is screwed in the sense to approach the sleeve 9 to the cylinder 3« By this action the valve means 7 is opened, and a free flow of the refrigerant 4 is induced through the capillary tube 14, the flexible intermediate tube 15, the pipe-coil of the evaporator unit 5, the separator buffer box 12, the end portion 16 and the outlet orifice 17 to the ambient atmosphere. Prom the cylinder 3 the liquid refrigerant 4 is discharged essentially in an atomized state caused by the capillary bore 14 into the evaporization conduit, i.e. into the pipe-coil. In the pipe-coil of the evaporator unit 5 the atomized liquid evaporates powerfully, and following this it escapes in gaseous form through the orifice 17 to the ambient atmosphere. The dissipation of the evaporation heat is performed practically in a total amount from the beverage 2 in a quick process and said dissipation is uniformly distributed over the whole volume to be chilled, which is due to the new arrangement of the inner cooling system according to the present invention. It results in an augmented very good efficiency which fact effects the aimed chilling the beverage in a quick manner to the convenient temperature for consumption. The separator buffer box 12 retains at the same time, all eventually not evaporated liquid phase of the refrigerant and all eventual impurities that may be present in the liquid phase. With this design only gaseous, i.e. evaporated refrigerant escapes through the orifice 17 into the ambient atmosphere. To prevent that by pouring out the beverage 2 through the already opened, originally lift-ring type closure 11 sealed opening of the can 1, the retained liquid phase in the separator buffer box 12 flows out by stooping the can 1, the separator buffer box 12 contains a porous, fibrous hygroscopic lining 13, which eventually can also be replaced by some kind of an inner coating either. The efficiency of the separator buffer box 12 can be raised by some special construction of the inlet and outlet positions and directions (e.g. tangential inlet and perpendicular central outlet, etc.) or by arranging different obstacles, bars, ribs,- chambers etc. within the separator buffer box 12 itself. The total efficiency of the device can be further raised by providing the outside wall of the can 1 with an appropriate thermal isolating coating, which prevents condensing water from the ambient atmosphere whereby the efficiency of the process would be negatively effected. As an example a preferred embodiment of the invention as described above,has had a can 1 containing 330 ccm beverage 2 using as refrigerant 4 200 g Preon 11/12 mixture. Upon initiation the cooling process the total amount of the beverage 2 cooled down by 20 centigrades within minutes. After use the device can be thrown away, i.e. it is disposable. By way of the present invention - especially for a more exigent clientele - a very favourable and advantageous consumer good has been developed. The device can be manufactured, provided with mass production tooling, equipment and automatic production lines, with very favourable economics in large series. OMPI

Claims: Claims 1. An improved disposable self-cooling device for chilling confined volumes, especially canned beverages, said device comprising a cylinder (3) capable of pertainin pressure and filled with a liquid or liquified refrigerant (4); an evaporator unit (5) arranged, together with said cylinder (3) within the confined volume, especially a thin metal sheet beverage can (1) to be chilled, said evaporator unit (5) being in heat-exchanging relationship with the confined volume, preferably beverage (2) to be chilled, the device further comprising a valve means (7) arranged either between said cylinder (3) and said evaporator unit (5) or between the latter and the ambient atmosphere, the valve means " (7) being normally closed and actuatable from outside the confined volume, i.e. the beverage can (1) to be chilled, wherein the improvement consists in said cylinder (3) being arranged substantially in the very centre part of the confined volume to be chilled, said evaporator unit (5) having the shape of a coiled tubular conduit that is wound along a substantially circular, spiralling path within the volume to be chilled surrounding said cylinder (3), and said evaporator unit (5) being arranged in duly spaced relationship to both said cylinder (3) and said thin metal sheet can (1) definin the confined volume to be chilled. 2. An improved disposable self-cooling device as claimed in Claim 1 wherein said evaporator unit (5) serves as heat exchanger of enlarged surface, and is formed from a metal tube of substantially low wall thickness made of a metal of good heat transfer characteristics such as aluminium or the like, said tube being shaped to a substantially cylindrical coil having pre erably several spiralling turns around but in duly spaced relationship to said cylinder (3) comprising the liquid or liquified refrigerant (4). 3. An improved disposable self-cooling device as claimed in Claim 1 wherein said evaporator unit (5) serve as a heat exchanger of enlarged surface, and is formed from a pair of abutting metallic plates, preformed to provide a continuous coiled conduit therebetween, said coiled tubular conduit being defined by coaxially bending said pair of plates of metal so as to arrive at a substantially annular cylindrical spiralling shape, and by fixing said plates together along at leas tbeir side peripheries as by welding. 4-. An improved disposable self-cooling device as claimed in any of the Claims 1 to 3whe ei said valve means (7) is arranged between said cylinder (3) and said evaporator unit (5), the valve means (7) bang actuatable manually, and being connected to an inlet of the substantially tubular conduit of said evaporator unit (5) via a capillary bore (14), while a free outlet orifice (17) of said conduit of the evaporator unit (5) is directly opened into the ambient atmosphere, preferably through a top plate (10) of the can (l) defining the confined volume to be chilled. 5. An improved disposable self-cooling device as claimed in Claim 4 wherein said cylinder (3) is provided with, a diving rod pipe (16) for forwarding mere liquid state, nongaseous refrigerant (4) to and through said valve means (7) into said evaporator unit (5), and said valve means (7) being the type that is commonly and widel in use with aerosol spraying devices known per se. SUBSTITUTE SKS Γ - 6. An improved disposable self-cooling device as claimed in any of the preceeding Claims 1 to 5 wherein a separator buffer box (12) for retaining any liquid phase refrigerant (4) is inserted into the passage way of the evaporating refrigerant passing the evaporator unit (5), said separator buffer box (12) being preferably arranged in or prior to an end portion (6) of the tubular conduit of said evaporator unit (5), substantially close to said free outlet orifice (17) opening into the ambient atmosphere. 7» An improved disposable self-cooling device as claimed in Claim 6 wherein the separator buffer box (12) has the shape of a substantially cylindrical receptacle, and it is arranged within the confined volume to be chilled preferably beneath and substantially in axial alignment with said cylinder (3) containing the liquid refrigerant (4) 3. An improved disposable self-cooling device as claimed in Claim 6 or 7 wherein said separator buffer box is provided with a lining (13) or an inside surface coating of some porous, fibrious or other hygroscopic material or agent. 9» An improved disposable self-cooling device as claimed in any of the Claims 4 to 8 wherein, to initiate chilling, a means for manually actuating said valve means (7) is provided for, said actuating means being preferably arranged at and hermetically led through a top plate (10) or a bottom plate of the thin metal sheet can (1) defining the confined volume to be chilled. 10. An improved disposable self-cooling device as claimed in Claim 9 wherein said means for manually actuating said valve means (7) comprises a threaded shaft /V - WIPO (8) engaged to a nut insert (19) that is fixed hermetically within said top plate (10) or even bottom plate of the can (l) defining the confined volume to be chilled, said threaded sha (8) being in axial alignment with and acting, upon its manual actuation, against a sleeve (9) arranged between said threaded sha t (8) and said valve means (7) , and said sleeve (9) being provided with an elbow bore leading from said valve means (7) to said capillary bore (14) for substantially dispersed, sprayed discharge of the liquid or liquified refrigerant (4-) from said cylinder (3) into said coiled tubular conduit of the evaporator unit (5). SUBSTITUTE SHEET List of Reference Signs of the Drawings can 1 beverage 2 cylinder 3 refrigerant 4 evaporator unit 5 end portion 6 valve means 7 threaded shaft 8 sleeve 9 top plate 10 lift-ring type closure 11 separator buffer box 12 lining 13 capillary bore 14 intermediate tube 15 diving rod pipe 16 outlet orifice 17 fixing means 18 nut insert 19

Inventors: HOFFMANN TIBOR, ROHONCI FERENC, HOFFMANN, TIBOR, ROHONCI, FERENC
Applicants: KOEZPONTI VALTO HITELBANK, KOEZPONTI VALTO- ES HITELBANK RT., INNOVACIOS ALAP
Application year: 1984
Main classification: F25D3
IPC codes: F25D3, F25D7, F25D31