DEVICE FOR COOLING AMD KEEPING COOL A CONTAINER FILLED WITH DRINK

The invention relates to a device for cooling and keeping cool a container at least partially filled with drink which comprises a base, a body and a cover, which device comprises a thermally insulating housing with a bottom and a body and an internal cavity defined thereby for accommodating a container with drink with a small peripheral spacing; carrying means supported by the bottom and/or the wall of the housing for the purpose of carrying the container; a removable thermally insulating cover for covering the cavity at least during use or during standby of the device; active cooling means for cooling and keeping cool the container with drink, comprising for instance a cooling device with a cooled outer surface driven by electrical energy, such as a Peltier element, these cooling means being adapted to cool the air present in the cavity between the container with drink and the inner surface of the housing, which container is intended for home use and is adapted for metered dispensing under pressure from the container, by means of a propellant, for instance carbon dioxide or nitrogen, of non-carbonated drink such as mineral water, fruit juice or wine, or carbonated drink such as sparkling mineral water, a soft drink or beer present therein, and comprises: a body; a base; a cover with a filling opening for passage of a filling conduit for filling the container with drink, and a tap opening for passage of drink during dispensing thereof via a dip tube, the free end of which is located close to the base of the container and the other end of which is connected to a spring-loaded non-return valve,

which is carried by the cover and which can be opened by a user by means of external operating means such as a pivotable handle for the purpose of dispensing drink via a tap conduit connected to the outlet of the non-return valve; and means for connecting sealingly to the container a holder for pressurized gas.

In order to enable tapping of a glass of beer at an ideal temperature of about 4 ⁰ C - 7 ⁰ C using a tapping device for home use, this device must have a cooling system. This cooling system cools the outer surface of the sealed container which is placed in the tapping device and in which the beer is situated.

Such a cooling system is known for instance from WO- A-99/11561. According to the art described herein, the container is placed in a chamber, the wall of which consists of a material which conducts the heat well. Placed against the outer side of this wall is a thermoelectrical Peltier element which cools the wall. The heat from the beverage in the container is herein discharged via the air located in the roughly cylindrical space between the container and the cooled wall. In a tapping device according to such a system the cooling of for instance a tin-plated keg with a volume of for instance 5 litres from room temperature to a consumption temperature of about 4 ⁰ C - 7 ⁰ C requires a time in the order of 12-24 hours. Two main reasons can be given for this long cooling time. Firstly, the cooling capacity of a Peltier element is in most cases limited and, secondly, the static air between the container and the wall of the chamber functions as an insulator.

In US-A-5 513 496 is described a device in which the air around the drink container is brought into and held in circulation by a fan. When the air passes along the cold outer surface of a Peltier element, the heat absorbed from the container is relinquished and discharged to the outside by the Peltier element.

DE-ϋ-20 2006 004 785 describes the application of a curved cooling plate which lies closely against the cylindrical body of a beverage container. The cold outer

surface of the Peltier element is connected to said cooling plate in a manner which conducts heat well. It will be apparent that a condition for a good heat transfer is that the cooling plate lies closely against the body of the beverage container.

Even when the means for transferring heat from the beverage container to the cooled outer surface of the Peltier element are properly embodied, the cooling time remains relatively long as a consequence of the limited capacity of the Peltier element. WO-A-2004/051163 therefore proposes a thermal buffer which is integrated into the tapping device and which can contain ice. Prior to placing of a beverage container in the tapping device this thermal buffer is charged by freezing the water, to which a certain quantity of glycol is added in order to lower the freezing point, in this buffer. The Peltier element of the tapping device is used for this charging. The thermal buffer lies against the base of the beverage container and cools particularly the beverage in the lower zone of this container. With a maximally charged thermal buffer it will be possible to tap drink at the correct temperature, albeit with a limited volume, relatively quickly after placing of the container in the device. When a thermal buffer of the tapping device is not charged, and also when a second beverage container is opened shortly after the first container, no shortening of the cooling time is realized with the system proposed in WO-A-2004/051163.

In addition to the known tapping devices with diverse cooling provisions briefly specified above, reference is now made to two other aspects which are relevant to the invention to be described hereinbelow.

A first aspect relates to the use of a cooling element frozen for instance in a deepfreeze instead of the thermal buffer disposed fixedly in the tapping device and to be charged by the Peltier element forming part of this device. These so-called "frozen pucks" are known from US-A-2006/0059944 and are used to cool small cans of drink, for instance with a volume of a maximum of 0.5 litre, via the base.

A second aspect relates to the contact of the thermal buffer with the drink container to be cooled. When the contact between the thermal buffer and the drink container leaves something to be desired, this results in an increased heat resistance which has an adverse effect on the heat transfer. Proposed in EP-A-I 293 738 is a flexible cooling element filled with a number of capsules which contain cooling agent and which are enclosed by a gel which is flexible even in the deep-frozen state. Because this element lies closely against the surface to be cooled due to this structure, the heat transfer is very good.

In relation to the above stated prior art it is an object of the invention to provide a device for cooling and keeping cool a container with drink, which device is able in a short time to cool a limited number of servings to a chosen consumption temperature, to then rapidly cool the rest of the content of the drink container to the same temperature level and subsequently keep the drink container at this temperature.

This object is realized according to the invention with a device of the type specified in the preamble which has the feature that a removable passive cooling element is placed in the lowermost zone of the cavity, which element can be cooled prior to placing to a temperature in the range of about -15 ⁰ C to -25 ⁰ C and is in intimate thermal contact with the base of the container such that the cooling element also forms part of the carrying means; such that, after placing of the container with drink on the cooling element, at least the drink in the lower zone of the container cools rapidly to a desired temperature as a result of the heat relinquished from this drink to the cooling element, and the container has a volume of at least 1 litre. In a preferred embodiment the device according to the invention comprises a thermally insulated cooling channel which extends outside the cavity and which connects with its one end to the top side of the cavity and with its other end to the underside of the cavity such that an air circuit is formed by the cooling

channel and the cavity, to which air circuit connects the cooled outer surface of the cooling device; and fan means arranged in the air circuit for the purpose of generating an airflow which flows along said cooled surface, flows downward through the cooling channel and flows upward in the cavity along the body of the container. As well as the rapid cooling of the drink in the lower zone of the container by the cooled cooling element, the additional effect is achieved with this structure that a cooling device such as a Peltier element can act to also effectively cool the rest of the drink in the container. The air circuit can be designed for a very good thermal insulation, and thus little heat loss and an optimum activity of the cooling device. A very practical embodiment has the special feature that at least a part of the cooling channel is incorporated in the body of the housing.

Practical and inexpensive is an embodiment in which the bottom, the body and the cover are embodied in foam with closed outer surfaces. This latter embodiment can be particularly implemented such that the bottom, the body and the cover are embodied in integral foam. Integral foam can be formed by injecting into an injection mould plastic which foams when heated, this with an excess of plastic such that it cures to form a closed mass on the walls of the mould cavity of the mould.

A very low heat resistance, and thereby a good heat transfer, is realized with an embodiment in which the upper surface of the cooling element has a form corresponding to the form of the base of the container. A practical embodiment of this latter principle has the special feature that the upper surface of the cooling element and the base of the container are both flat .

According to a specific aspect of the invention, the above described two embodiments can have the special feature that the upper surface of the cooling element is a metal, for instance aluminium, plate forming part of the cooling element.

According to a further aspect, this latter embodiment can have the special feature that the metal plate has an upright peripheral edge such that a heat- conducting fluid, for instance water, can be poured into the thus formed tray for the purpose of bringing about a low heat resistance between the cooling element and the base of the container.

In an alternative the device has the special feature that the upper surface of the cooling element is flexible at the temperature of the precooled cooling element and can adjust itself to the shape of the base of the container.

A very rapid and efficient cooling of the drink in the container is realized with an embodiment in which the cooling element is in heat-exchanging contact with the air circuit.

An even more rapid cooling is realized with an embodiment in which heat-conducting, area-enlarging means, for instance metal, such as aluminium, fins are added to the cooling element, which fins extend into the air circuit. The cooling element can thus be wholly encased with for instance a metal, particularly an aluminium, casing optionally provided with the above specified upright peripheral edge, wherein the thus heat-conducting outer casing is provided with said area- enlarging means such as fins, ribs, pins, wires or the like, along which the air from the cooling device flows and then, after undergoing here an additional temperature reduction, flows along the body of the container. Since in first-order approximation the heat flow is directly proportional to the difference in temperature between the flow-by air and the body of the container, the speed at which the drink in the container cools will, as will be apparent, increase due to this measure.

According to another aspect of the invention, the device comprises a first temperature sensor for measuring the temperature in the first zone of the container, and first indicating means for generating an associated temperature indication under the control of the first temperature sensor.

The device can also comprise a second temperature sensor for measuring the temperature of the cooling element, and second indicating means for generating an associated temperature indication under the control of the second temperature sensor.

According to a final aspect of the invention, the device has the special feature that the cooling element comprises a hollow panel filled with a cooling medium which is fluid at room temperature and has a freezing point in the range between about 0 ⁰ C and -25 ⁰ C, for instance a glycol-water mixture.

The invention will now be elucidated with reference to the accompanying figure. This figure shows a cross- section of a random exemplary embodiment of a device according to the invention for tapping beer.

The only figure shows a device 1 for cooling and keeping cool a vessel 2 with drink, in this case a tin- plated keg of beer with an effective volume of about 5 litres. Device 1 comprises a thermally insulating housing 3 consisting of integral foam and having a bottom 4, a body 5 and a cover 6 carried removably by body 5, this housing defining an internal cavity 7 for accommodating vessel 2 with a small peripheral spacing 8, carrying means 22, 23, 24, 26 to be described hereinbelow for carrying vessel 2 and cooling means, and per se known tap means for cooling and keeping cool the vessel 2 with beer. The vessel is intended for home use and is adapted for metered dispensing of the beer from vessel 2 by means of pressurized carbon dioxide from a carbon dioxide cartridge 9.

Vessel 2 comprises a body 10, a base 11 and a cover 12 with a filling opening for filling vessel 2 with beer and an tap opening 13 for passage of beer during dispensing thereof via a dip tube 14, the free end 15 of which is located close to the base 11 of the vessel and the other end 16 of which is connected to a spring- loaded non-return valve 17 which is carried by cover 12 and which can be opened by a user by means of external operating means, such as an in this case schematically shown pivotable handle 18, for the purpose of dispensing

beer via a tap conduit which is connected to the outlet of non-return valve 17 and the tap end 20 of which is situated above a carrier 21 for a drip tray.

Device 1 comprises a removable passive cooling element 22 placed in the lowermost zone of cavity 7. Before being placed on the bottom 4 of cavity 7, this cooling element 22 is cooled to a temperature of for instance -18 ⁰ C. Cooling element 22 is filled with a mixture of for instance 20% by weight glycol and 80% by weight water, and has an aluminium peripheral casing 23, an aluminium upper plate 24 and an aluminium base 25 which bears aluminium cooling fins 26 in star-shaped arrangement. In this way the cooling fins support cooling element 22, and in the manner shown the aluminium upper plate 24 of cooling element 22 supports the base 11 of vessel 2. It will be apparent that this structure ensures that the base 11 of vessel 2 is in intimate thermal contact with aluminium upper plate 24, and the beer in the lowermost zone of vessel 2 can thus readily relinquish its heat to cooling element 22.

It is noted that upper plate 24 is provided with an upright peripheral edge 27 which is received in a corresponding peripheral recess 28 of base 11 of vessel 2. Due to the presence of peripheral edge 27, some water can be introduced onto plate 24 immediately preceding placing of vessel 2 for the purpose of a very low heat resistance.

Extending through body 5 is a cooling channel 29 which connects to cavity 7 on the top side and the bottom side and thus forms an air circuit therewith.

Connecting to this air circuit, in this case to cooling channel 29, is the cold outer surface 30 of a Peltier element 31 which is powered with electrical energy by connecting means (not shown) and which can relinquish its heat to the atmosphere by means of a first fan 32. Placed in said air circuit, in this case at the position of the transition between the upper zone of cavity 7 and upper zone 33 of cooling channel 29, is a second fan 34 which serves to bring about and maintain an airflow through the described air circuit. The air flowing through this air circuit is designated with arrows 35.

The airflow from fan 34 flows in downward direction through cooling channel 29, along the cold outer surface 30 of Peltier element 31 therein, via an air feed opening 35 in the bottom 4 to cavity 7, there flows first along the cooling fins 26, is there cooled and, following cooling by Peltier element 31, is there additionally cooled by cooling element 22 and, after this dual cooling, flows along the outer surface of body 10 of vessel 2. On the top side the air, which has hereby been heated again to some extent, is once again carried via upper zone 33 into cooling channel 29 by the action of fan 34.

Shown schematically is a first temperature sensor 36 which serves to measure the temperature in the first lower zone of vessel 2. This sensor can for instance be based on an infrared measurement. The sensor is connected to first indicating means (not shown) for making known to the user that a temperature may be too low. A second temperature sensor 37, which can likewise be based on an infrared measurement, measures the temperature of peripheral casing 23 of cooling element 22. Second indicating means, which are controlled by this second temperature sensor, give a user an indication for instance of when the temperature of cooling element 22 has risen so far that it must be replaced or cooled. This can particularly be the case with successive use of multiple vessels 2 with beer. The invention is not limited to the described exemplary embodiment. Peltier element 31 and second fan 34 can for instance also be positioned at another location in the air circuit.

A cooling device other than a Peltier element can further also be applied, for instance an evaporation cooler or a cooler based on a compressor/evaporator.

A flexible heat-conducting cushion can further be added to upper plate 24 of cooling element 22, this cushion still having a sufficient degree of flexibility and viscosity at the temperature of the cooled cooling element 22 to be able to adjust itself to the shape of the base of vessel 2. This base need not necessarily be

flat therefore, but can in principle take any technically appropriate form.