The present Invention relates to a method and a system for pressurising and dispensing carbonated beverages stored in a keg or container.

Carbonated beverages, such as beer and soda, are typically provided in pressure- proof containers such as cans or kegs. The beverage may either be pre-carbonated by the beverage producer or alternatively the beverage is carbonated while dispensing the beverage. Professional beverage dispensing systems typically use beverage containers such as kegs, which are connected to a carbon dioxide source for carbonating the beverage and to maintain a pressure inside the beverage container while dispensing the beverage through a tapping device Private users however typically use pre-carbonated beverage containers such as cans. Pre- carbonated beverages have the drawback that when the beverage container has been opened, oxygen will enter the beverage and carbon dioxide will escape. The oxygen entering the beverage container causes the beverage to deteriorate Typically, the quality of the beverage will have reached unacceptably low levels within some hours after opening the beverage container Thus, typically pre- carbonated beverages are provided in small containers such as cans suitable for one serving of beverage having a volume such as 0.25-0 75 litres Professional or semi-professional beverage dispensing systems typically operate with large containers or kegs, which may contain 10-50 litres or more of beverage

A medium-sized beverage container, often referred to as a party-keg or mini-keg, is a pre-carbonated container having a volume ranging between the professional kegs and the cans, such as 3-10 litres and in particular 5 litres. A mini-keg may be used for dispensing beverage and storing a beverage over an extended time period such as several days or weeks even if the mini-keg has been opened if the mini-keg is used together with a beverage dispensing system having a pressurisation system. One example of a beverage dispensing system is the DraughtMaster™ system provided by the applicant company and described in the PCT applications WO2007/019848, WO2007/019849, WO2007/019850, WO2007/019851 and WO2007/019853 The DraughtMaster™ system seals the beverage container from the surrounding oxygen and provides pressurisation and cooling to avoid loss of carbon dioxide and deterioration of the beverage.

Some consumers may however prefer a cheaper and simpler beverage dispensing and pressurisation system, which may preferably be intended for single use only and be disposable together with the beverage container when empty It is therefore an object of the present invention to provide technologies for pressurising and dispensing a beverage without the need for any external non-disposable equipment,

There is thus a need for a cheap and simple solution for pressurising a beverage keg. Some examples of self-pressurising beverage kegs are found in European patent publications EP 1 737 759 and EP 1 170 247. Both the above known technologies make use of commercial available CO ₂ cartridges containing pressurised CO ₂ (carbon dioxide), propeliant and a pressure regulation mechanism, The CO ₂ cartridges are used for carbonating and pressurising the beverage and the beverage container as the pressure is reduced due to the dispensing of the beverage and leakage during storage. The cartridge will occupy space, which cannot be used for beverage. Therefore, the cartridge should preferably be small in relation to the volume of the beverage container. To be able to generate a suitable amount of CO ₂ from a small cartridge to pressurise a significantly larger beverage container the cartridge must have a high pressure. The above-mentioned publications EP 1 737 759 and EP 1 170 247 suggest the use of a filler material such as activated carbon for reducing the pressure inside the cartridge. The high pressure in the cartridges of the above-mentioned technologies may still constitute a safety hazard due to the risk of explosion, especially in case the cartridge is heated. It is therefore a further object of the present invention to provide technologies for dispensing and pressurising a beverage stored inside a container without the use of high-pressurised cartridges and where the pressure remains close to ambient pressure, at least until starting the beverage dispensing operations.

Some commercially available mini-kegs are made of metal. In order to be considered an environment-friendly material, metal should be recycled. However, in many cases the above mini-kegs are not suitable for recycling since they differ from normal recyclable metal cans and kegs since they may contain a multitude of different materials, which may not be separable and recyclable or environment- friendly disposed There is thus a need for disposable mini-kegs of a single disposable material, which may be environment-friendly disposed It is therefore a further object of the present invention to provide a disposable beverage dispensing system

The above need and the above object together with numerous other needs and objects which will be evident from the below detailed description are according to a first aspect of the present invention obtained by a Cθ2-generating device for use with a beverage included in a beverage container or beverage dispensing system, in particular a draught beer system, the CO ₂ -generating device comprising: a CCVgenerating chemical system including two distinct chemical compounds constituting a first chemical compound and a second chemical compound for generating CO ₂ through chemical reaction when mixed together, the CO ₂ -generating device defining: a pre-activation stage in which the first and second chemical compounds are being stored separately relative to one another, and a post-activation stage, in which the first and second chemical compounds are being at least partially mixed together

In relation to the above CO ₂ -generating device it has been surprisingly found that by using a chemical pressure generator, the use of high-pressurised CO ₂ cartridges may be completely avoided. The chemical pressure generator comprises a chemical system where the CO ₂ is stored in a chemical compound at ambient pressure. The CO ₂ -generating chemical system may include two distinct compounds where at least one of the compounds constitutes a CO ₂ compound and at (east the other compound constitutes a substance which releases the CO ₂ from the previous compound when both compounds are mixed.

The first and the second compounds should generate CO ₂ through chemical reaction without generating any hazardous or non-degradable by-product or any substantial amount of heat Any by-products which may contaminate the beverage should be avoided Since most beverages including draught beer should be served chilled, an excessive heat generation should be avoided as well it is further evident that the two compounds themseives should be non-hazardous, non-toxic and preferably biologically degradable.

The beverage container including the CCVgenerating device is preferable produced and shipped to the customer and installed by the customer before any chemical reaction is allowed to start. Just before the customer is about to dispense the beverage, the chemical reaction is preferably activated The chemical reaction may be activated by a mechanical operation by the customer such as pressing a button or the like, which causes the two compounds to mix. The two compounds should be chosen among compounds generating CO ₂ relatively quickly, i.e for the gas generation and optionally carbonisation to occur within a few seconds after the customer has started the chemical system In this way the customer may start dispensing the beverage without any substantial delay

The beverage container or beverage dispensing system should preferably include a beverage tap, which may be opened to dispense the beverage in the post-activation state. The pressure inside the beverage container may provide the dispensing pressure for forcing the beverage out of the beverage container or beverage dispensing system.

The CO ₂ -generating device assumes the pre-activation stage during production, transport to customer and storage at the customer location When the customer is about to start dispensing the beverage, the customer activates the CO ₂ - generating device, which changes the state of the CO ₂ ~generating device from the pre- activation stage to the post-activation stage. By storing the first compound and the second compound separately, the chemical reaction is prevented. The separation may be achieved by a separation element, e.g a wall, gate, membrane, foil etc , separating the two components. Upon activation, the separation element is removed or ruptured such that the first and second compounds may mix. The mixing of at least part of the first compound and second compound defines the post-activation stage The amount of each compound, which is included in the mixture, should be chosen to achieve an efficient production of CO ₂ and avoid any waste of compounds In the above context storing the first compound and the second compound separately should be construed in a chemical context, i.e. the two components should be stored such that no chemical reaction may start between them, and in particular no CO ₂ may be produced. Consequently, when the two components are mixed in the post-activation stage, the two components may react and start producing CO ₂ ,

It is further contemplated that in the transition from the pre-activation stage to the post-activation stage in which the above mentioned chemical compounds are mixed, the pressurisation and carbonisation process begins and a return from post- activation stage to pre-activation stage is not possible, at least not without considerable effort. However, in some embodiments the two components may be mixed only partly at the transition from the pre-activation stage to the post-activation stage, such that a further activation may be performed. For instance, a further activation may be necessary after some amount of beverage has been dispensed and the pressure in the beverage container is too low for continuing efficient beverage dispensing.

According to a further embodiment of the first aspect according to the present invention the first chemical compound is being dissolved in an aqueous solution, at least when in the pre-activation stage, or alternatively the second chemical compound is being dissolved in an aqueous solution, at least when in the pre- activation stage, or alternatively both the chemical compounds are being dissolved in two separate aqueous solutions, at least when in the pre-activation stage, or alternatively each of the first chemical compound, the second chemical compound and the aqueous solution are being stored separately when in the pre-activation stage,

For ensuring a quick and efficient CO ₂ production, the chemical reaction is initiated when both the first compound and the second compound are mixed in an aqueous solution. In this context it should be mentioned that commercially available substances exist which may be used for producing CO ₂ without the use of an aqueous solution. However, using an aqueous solution will for most chemical systems accelerate the reaction speed and thereby produce CO ₂ more efficiently.

Since the chemical reaction does not start until all three of the first compound, second compound and aqueous solution are mixed, it is not necessary to keep the above-mentioned chemical compounds and the aqueous solution separated in the pre-activation stage. It may be contemplated that any of the two compounds may be dissolved in the aqueous solution already in the pre-activation stage, and the other compound being added to the aqueous solution when switching from the pre- activation stage to the post-activation stage. A further alternative embodiment includes having the first and second compounds dissolved in two separate aqueous solutions. When switching from the pre-activation stage to the post-activation stage, the two separate aqueous solutions are mixed and thereby the chemical reaction is started. A further alternative is to have the two compounds separated in the pre- activation stage without the aqueous solution. The transition from the pre-activation stage to the post-activation stage may be performed by adding an aqueous solution to the first and second compound and mixing them. This may include having small solid pieces of the first and second compound, which mix when adding the aqueous solution. The aqueous solution may comprise pure H ₂ O

According to a further embodiment of the first aspect according to the present invention the first chemical compound constitutes an acid and the second chemical compound constitutes a salt.

In relation to the choice of the compounds included in the chemical system, it has been contemplated that the second compound may constitute a salt being a compound including CO ₂ . Typically such salts may release CO ₂ when mixed together with an acid in an aqueous solution. Concerning the acid, preferably a weak acid is chosen which is non-toxic and which does not cause any environmental hazard if released. The salt should as well be chosen among those salts including CO ₂ which are non-toxic and do not cause any environmental hazard. According to a further embodiment of the first aspect according to the present invention the first chemical compound comprises any of the following acids: citric acid, tartaric acid, pyruvic acid, potassium hydrogen sulphate, glutaric acid, phthalic acid, ascorbic acid, benzoic acid or the like, and the second chemical compound comprises any of the following salts: sodium bicarbonate, sodium hydrogen carbonate or potassium hydrogen carbonate, calcium hydrogen carbonate, magnesium hydrogen carbonate, or the like,

In the above context it has been found that the combination of citric acid and sodium bi-carbonate in an aqueous solution does fulfil the above requirements of being environment-friendly substances as well as generating CO ₂ in a relatively quick and efficient way.

According to a further embodiment of the first aspect according to the present invention the first chemical compound and/or the second chemical compound are provided in the form of granulate, powder or paste

For the first and second compounds to dissolve as quickly as possible in the aqueous solution, the first and/or second compounds may be provided in the form of granulate or powder Since the chemical reaction cannot start until at least some of the compounds have been dissolved in the aqueous solution, the time for dissolving the first and second compounds in the aqueous solution is added to the reaction time to calculate the total pressurisation time needed to pressurise and carbonize the beverage in the beverage container By providing the first and second compounds as granulates, the time for dissolution in the aqueous solution is minimised. Alternatively, the first and/or second compounds may be provided in the form of a paste The paste has better flow properties than granulate and powder, i.e less flow resistance compared to granulate and powder. The paste may thus be simpler to handle and it may be simpler to ensure that the correct amounts of chemical compounds are being mixed. According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device further comprises at least one rupturable wall, in particular a pierceable wall, for separating at least one of the first, second and third chemical compounds when in the pre-activation stage, and where the rupturable wal! is being ruptured when in the post-activation stage.

By providing a rupturable wall between at least one of the first compound, second compound and aqueous solution during the pre-activation stage, it can be secured that once the post-activation stage has been reached, the device cannot again assume the pre-activation stage. A rupturable wall serves the purpose of separating at ieast one of the chemical compounds mentioned above during the pre-activation stage and mixing the above-mentioned chemical compounds in the post-activation stage by using a minimum amount of compounds. The rupturable wall may e.g. comprise a pierceable wall which may comprise a thin membrane which may be pierced by the use of a piercing element which may comprise a thin rod, nail or the like

According to a further embodiment of the first aspect according to the present invention the CU ₂ -generating device is being located outside the beverage container or beverage dispensing system, at least when in the pre-activation stage.

The CO ₂ -generating device may be provided as a stand-alone device for use with any kind of beverage containers or beverage dispensing systems. For instance, some kind of beverage which is provided in a non-carbonated state may be carbonated by the use of a stand-alone CO ₂ -generating device and afterwards instaϋed in a beverage dispensing system as known in the state of the art. A variety of different types of simple and disposable beverage dispensing systems or devices may be contemplated comprising the CO ₂ -generating device according to the present invention.

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device is being at least partially submerged in the beverage included in the beverage container or beverage dispensing system, at least when in the post-activation stage.

The CO ₂ -generating device may be provided at least partially submerged in the beverage or it may be submerged during the transition between the pre-activation stage and the post-activation stage. By submerging the CU ₂ -generating device it can be ensured that the CO ₂ generated by the chemical system enters the beverage in the post-activation stage for carbonating the beverage. For the purpose of carbonating the beverage, other alternatives exist, e g. the CO ₂ -generating device may be positioned outside the beverage and have a tube for allowing the CO ₂ to reach the beverage. The CO ₂ -generating device may also be used as a so-called widget in a beverage can for providing a foam similar to a draught beverage from an ordinary pre-carbonated can used for one serving of beverage only.

According to a further embodiment of the first aspect according to the present invention the beverage container or beverage dispensing system comprises an inner flexible bag and an outer enclosure defining a space between the inner flexible bag and the outer enclosure, the inner flexible bag including the beverage which is optionally pre-carbonated, the space between the inner flexible bag and the outer enclosure being in fluid communication with the CO ₂ -generating device.

The CO ₂ -generating device may optionally be used together with a so-called double keg A double keg comprises an inner bag or similar flexible structure for accommodating the beverage. The inner bag is surrounded by an outer enclosure, which is preferably a rigid enclosure. The outer enclosure has a pressure inlet and the inner flexible bag has a beverage outlet, which is connected to the outside of the beverage container

By pressurising the space between the inner flexible bag and the outer enclosure, the beverage in the inner bag may be pressurised without being in direct contact with the pressurising fluid, i.e. the CO ₂ . This is preferred if the beverage is not intended to be carbonated, but the CO ₂ is merely used for pressurising and dispensing the beverage. According to a further embodiment of the first aspect according to the present invention the transition from the pre-activation stage to the post-activation stage requires the beverage container or the beverage dispensing system being positioned in a substantially upright position, or alternatively in a substantially pivoted position

For the purpose of carbonating the beverage, it may be required that the beverage container or alternatively the beverage dispensing system is oriented in a specific position to allow the CO ₂ -generating device to carbonate the beverage sufficiently. Additionally, the beverage container or the beverage dispensing system may have to be oriented in a specific position to be able to dispense the beverage correctly. For instance, if the dispensing tap of the beverage container or beverage dispensing system is located near the bottom of the beverage container or beverage dispensing system, trying to carbonate or dispense the beverage while positioning the beverage container or the beverage dispensing system upside down, i e with a dispensing tap on top, may result in insufficient carbonisation and/or failure to dispense any beverage since possibly only CO ₂ is dispensed. The beverage container or beverage dispensing system may be fitted with an ascending pipe or similar pipe structure for allowing (as required) a variety of different dispensing positions when the CO ₂ -generating device is in the post-activation stage.

According to a further embodiment of the first aspect according to the present invention the post-activation stage comprises a carbonating stage in which at least some amount of CO ₂ generated by the CO ₂ -generating chemical system is used for carbonating the beverage included in the beverage container or beverage dispensing system.

Immediately when switching from the pre-activation stage to the post-activation stage, some amount of CO ₂ may be generated by the chemical system and used for carbonating and pressurising the beverage inside the beverage container or beverage dispensing system. A suitable amount of the first and the second compound may be mixed for generating a suitable amount of CO ₂ carbonating the beverage.

According to a further embodiment of the first aspect according to the present invention the post-activation stage comprises a dispensing stage in which at least some amount of CO ₂ generated by the CO ₂ -generating chemical system is used for substituting at least some amount of the beverage inside the beverage container or beverage dispensing system when the beverage is being dispensed from the beverage container or beverage dispensing system.

The beverage inside the beverage container or the beverage dispensing system is typically dispensed by the pressure force applied by the pressurised CO ₂ within the beverage container or beverage dispensing system. When some amount of beverage has been dispensed, the CO ₂ pressure will fall within the beverage container or beverage dispensing system due to the reduced volume inside the beverage container or beverage dispensing system. The volume of dispensed beverage has to be replaced by a corresponding volume of CO ₂ to avoid a pressure drop inside the beverage container or the beverage dispensing system and to be able to continue the beverage dispensing operations. While dispensing the beverage, some amount of CO ₂ may be generated by a chemical system to maintain the dispensing pressure and to substitute the amount of dispensed beverage.

According to a further embodiment of the first aspect according to the present invention the post-activation stage comprises an active storage stage in which at least some amount of CO ₂ generated by the CO ₂ -generating chemical system is used for compensating for pressure losses in the beverage container or beverage dispensing system caused in particular by CO ₂ leakage during storage

When the beverage container or the beverage dispensing system is stored for a longer period of time it cannot be avoided that some amount of CO ₂ will escape from the beverage container or the beverage dispensing system due to leakage. By continuously generating some amount of CO ₂ by the chemical system, the pressure loss due to leakage may be compensated and the period of time during which the beverage can be stored is significantly extended. A beverage container or a beverage dispensing system without an active storage stage may typically keep up sufficient carbonization for a few days at the most. By using an active storage stage, the storage time during which the pressure in the beverage container is sufficiently high, may be extended to one month or more.

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device further comprises a regulator, in particular a membrane or a piston being in fluid communication with the interior and the exterior of the beverage container or beverage dispensing system, for regulating the pressure inside the beverage container, and when the pressure inside the beverage container or beverage dispensing system drops below a specified minimum pressure, at least some amount of CO ₂ is generated by the CO ₂ -generating chemical system and released into the beverage container or beverage dispensing system for maintaining a specific pressure inside the beverage container or beverage dispensing system..

In particular, the pressure inside the beverage container or the beverage dispensing system may be regulated in relation to a known pressure such as the atmospheric pressure. In particular, a membrane or a piston may be used to detect a loss of pressure inside the beverage container or the beverage dispensing system in relation to the known pressure source. The membrane or piston may then activate the chemical system, which may start producing CO ₂ if the pressure in the beverage container is below the minimum pressure. When the pressure in the beverage container or the beverage dispensing system has again surpassed the minimum pressure, the chemical system may be stopped and remain stopped until the pressure has dropped below the minimum pressure where production of CO ₂ is restarted.

According to a further embodiment of the first aspect according to the present invention the minimum pressure is between 1.2 and 2 bar absolute pressure and in particular 1.5 bar absolute pressure. I has been contemplated that 1.5 bar of absolute pressure corresponding to 0.5 bar relative pressure (assuming 1 bar ambient pressure) may be sufficient for maintaining most beverages in a pressurised fresh state free of oxygen. A pressure that is too low cannot avoid oxygen from entering the beverage container or the beverage dispensing system, and a pressure that is too high may constitute a safety hazard due to the risk of explosion of the beverage container or the beverage dispensing system.

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device further comprises an on demand pressure generator which for each beverage dispensing operation causes the Cθ2-generating chemical system to generate an amount of CO ₂ sufficient for substituting an amount of beverage in the beverage container or beverage dispensing system corresponding to the dispensed volume, alternatively a typical serving of the beverage.

The on demand pressure generator may work to compensate the loss in pressure caused by each dispensing operation by mixing a certain amount of chemical compounds corresponding to the volume of the typical serving of beverage such as e.g. a pint or a beer. The on demand pressure generator may be coupled to e.g. a level of beverage inside the beverage container or the beverage dispensing system by e.g. a floating device. Alternatively, each time the dispensing handle is operated, a certain amount of chemical compounds may be mixed for generating an amount of CO ₂ corresponding to the typical amount of beverage dispensed for one serving of beverage.

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device further comprises a CO ₂ gas absorbing buffer material such as activated carbon.

Some embodiments according to the present invention may comprise a buffer for accommodating any excessive CO ₂ , which might be produced by the chemical system. The excess pressure may otherwise cause an overpressurisation of the beverage container or the beverage dispensing system. Such overpressurisation may cause additional leakage or possibly an explosion. A buffer known from the prior art is activated carbon, which may accommodate CO ₂ by adsorption, In this way the beverage container or the beverage dispensing system may be reduced.

According to a further embodiment of the first aspect according to the present invention the Cθ ₂ -generating device comprises at least 2 compartments, such as 2- 3 compartments, for storing the first, second and third chemical compounds.

Two or more compartments may be used to arrange the first compound, the second compound and aqueous solution when in the pre-activation stage. Further compartments may be used to avoid all of the chemical compounds reacting at the same time,

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device comprises only ecologically disposable materials, such as combustible materials or biologically degradable materials.

Preferably only disposable materials are used in the CO ₂ -generating device. Such disposable materials may be e.g. a combustible material such as PEP plastics or the like. The chemical system including the first compound and the second compound comprises preferably biologically degradable materials. Such materials may e.g. be the previously mentioned citric acid and sodium bicarbonate, which will biologically degrade within a short period of time after disposal

According to a further embodiment of the first aspect according to the present invention the CO ₂ -generating device comprises an excess pressure valve for relieving the CO ₂ -generating device of any excess pressure, at least when in the post-activation state.

The excess pressure valve may be used as an overpressure valve to relieve the beverage container or the beverage dispensing system from excessive pressure, which may be caused by excessive CO ₂ production An overpressure in the beverage container or the beverage dispensing system may further be caused by temperature variations or similar external influence The excess pressure valve may further be used to permanently reduce any overpressure in the beverage container or the beverage dispensing system when all of the beverage has been dispensed and the Cθ ₂ -generating device is about to be disposed. The excess pressure valve may optionally be open in the pre-activation state to avoid any pressurisation of the beverage container or the beverage dispensing system. The excess pressure valve may e g comprise a spring-loaded valve which is set to open to the outside environment at a specific pressure relation between the beverage container or the beverage dispensing system and the outside environment, i e. the atmospheric pressure.

According to a further embodiment of the first aspect according to the present invention the pressure in the CCVgenerating device while in the pre-activation state is substantialiy equal to the pressure outside or alternatively inside the beverage container or beverage dispensing system.

Preferably, the pressure inside the CO ₂ -generating device is substantially equal to the pressure outside the CO ₂ -generating device, i e. the atmospheric pressure, or the pressure inside the beverage container or beverage dispensing system. This will reduce the risk of the CO ₂ -generating device bursting or exploding during transportation and handling. By using the above-mentioned chemical system, the pressure in the CO ₂ -generating device may be kept at any pressure since the CO ₂ is not generated until it is needed, i.e. when the beverage is about to be carbonated, dispensed or stored for a longer period of time in the post-activation stage

The above need and the above object together with numerous other needs and objects which will be evident from the below detailed description are according to a second aspect of the present invention obtained by a beverage dispensing system comprising a beverage container, a tapping unit and a CO ₂ -generating chemical system, the CO ₂ -generating chemical system including two distinct chemical compounds constituting a first chemical compound and a second chemical compound for generating CO ₂ through chemical reaction when mixed, the beverage dispensing system defining: a pre-activation stage in which the tapping unit is preventing beverage dispensing and the first and second chemical compound are stored separately relative to one another, and a post-activation stage in which the tapping unit is selectively allowing beverage dispensing and the first and second chemical compounds are being at least partially mixed together,

From the above description it is evident that the Cθ ₂ -generating device described above in relation to the first aspect of the present invention may be integrated into a beverage dispensing system according to the second aspect of the present invention

According to a further embodiment of the second aspect according to the present invention the CO ₂ -generating chemical system is used for carbonating the beverage in the beverage container and for pressurising the beverage in the beverage container, or alternatively the CO ₂ -generating chemical system may be used only for pressurising the beverage in the beverage container, and yet alternatively the CO ₂ - generating chemical system may be used only for carbonating the beverage in the beverage container.

The CO ₂ -generating device according to the second aspect of the present invention may be used for both carbonating the beverage in case of a non-pre-carbonated beverage and for pressurising the beverage for allowing the beverage to be dispensed Alternatively, in case of a pre-carbonated beverage the COz-generating device according to the second aspect of the present invention may be used only for pressurizing the beverage, and yet alternatively, if the beverage dispensing system has an integrated pressurisation unit, the CO ₂ -generating device according to the second aspect of the present invention may be used only for carbonating the beverage The above need and the above object together with numerous other needs and objects which wil! be evident from the below detailed description are according to a third aspect of the present invention obtained by a method of pressurising a beverage included in a beverage container or beverage dispensing system, in particular a draught beer system by providing a Cθ ₂ -generating chemical system including two distinct chemical compounds constituting a first chemicai compound and a second chemical compound for generating CO ₂ through chemical reaction when mixed together, storing the first and second chemical compound separately relative to one another, and generating CO ₂ by at least partially mixing together the first and second chemical compounds.

From the above description it is evident that the method according to the third aspect of the present invention may preferably be used together with the systems described above in relation to the first and second aspect of the present invention, in which the storing of the first and second chemicai compound separately in relation to each other corresponds to the pre-activation stage and the generation of CO2 by at least partially mixing together the first and second chemical compounds corresponds to the post-activation stage. It is further evident that any of the features of the first and second aspect of the invention applies to the third aspect as well.

The present invention is now to be described in greater detail with reference to the drawings where

Fig. 1 is a beverage dispensing system including a pressure generator and a single- layered beverage container containing a non-pre-carbonated beverage, Fig, 2 is a beverage dispensing system including a pressure generator and a single- layered beverage container containing a pre-carbonated beverage, Fig. 3 is a beverage dispensing system including a pressure generator and a double-layered beverage container containing a non-pre-carbonated beverage, Fig. 4 is a beverage dispensing system including a pressure generator and a double-layered beverage container containing a pre-carbonated beverage, Fig 5 is a beverage dispensing system for multiple use including a pressure generator and a beverage container filled with non-pre-carbonated beverage,

Fig. 6 is a beverage can having a carbonating widget,

Fig. 7 is a two fluid self-regulating pressure generator having a flexible membrane, Fig 8 is a one fluid self-regulating pressure generator having a flexible membrane,

Fig. 9 is a one fluid self-regulating pressure generator having a spring-loaded piston,

Fig 10 is a granulate self-regulating pressure generator having a spring-loaded piston,

Fig 1 1 is a paste self-regulating pressure generator having a spring-loaded piston, Fig. 12 is a dual paste self-regulating pressure generator having two spring-loaded pistons,

Fig 13 is an on demand pressure generator in a closed off state,

Fig. 14 is an on demand pressure generator in an open state, and

Fig 15 is an on demand pressure generator having a paste and a liquid

A detailed description of the figures of some presently preferred embodiments according to the present invention follows beiow

Fig. 1 a shows a beverage dispensing system 10 The beverage dispensing system 10 comprises a beverage container 12, which is filled with a non-pre-carbonated beverage. The beverage container is made of plastics such as PET and preferably blow moulded The upper part of the beverage container 12 comprises a beverage outlet 14, which further comprises a set of outward protruding flanges 16, A closure 18 covers the beverage outlet 14. The closure 18 comprises a set of inward protruding flanges 17 which are interacting with the outward protruding flanges 16 of the beverage outlet 14 for sealing the closure 18 tightly on the beverage outlet 14 of the beverage container 12, The closure 18 covers and seals the beverage outlet 14 of the beverage container 12 The closure 18 has an attached tapping line 20 which extends through the closure 18 towards the bottom of the beverage container 12. The tapping line 20 constitutes an ascending pipe for allowing the beverage to leave the beverage container 12 Outside the beverage container 12 the tapping line 20 extends towards a tapping valve 22 The tapping valve 22 controls the flow of beverage of the beverage container 12 and may preferably constitute a squeeze-off valve or the like. The tapping valve 22 further comprises a handie 24 for operating the tapping valve 22, The beverage leaves the tapping valve 22 through a beverage tap 26. The beverage dispensing system 10 further includes a pressure generator 28 which is attached to the closure 18, The pressure generator 28 comprises an upper compartment 30 comprising a mixture of water and citric acid. The pressure generator 28 further comprises a lower compartment 32 comprising a mixture of water and sodium bicarbonate. The upper and lower compartments 30 and 32, respectively, are made of substantially rigid material such as preferably PET plastics. The wall separating the upper compartment 30 and the lower compartment 32 constitutes a thin foil or membrane 34. The upper compartment has an attached piercing element 36 constituting a rod or nail or the like which is operable from the outside of the pressure generator 28 and extendable towards the membrane 34. The upper compartment 30 further has a pressurising hose 38 connecting the upper compartment 30 through the closure 18 to the interior of the beverage container 12. The pressure generator 28 may further comprise a filler 40 preferably comprising activated carbon. The filler 40 will absorb the generated CO ₂ molecules when the pressure rises and release them when the pressure falls, thereby reducing the maximum pressure generated by the pressure generator 28 and exerted on the beverage container 12, The filler 40 may be positioned either in the upper compartment 30 or in the lower compartment 32 or distributed in both compartments 30, 32.

Fig. 1b shows the beverage dispensing system 10 when the piercing element 36 has been extended into the membrane 34. The piercing element 36 ruptures the membrane 34 and allows the citric acid solution stored in the upper compartment 30 to mix with the sodium bicarbonate solution stored in the lower compartment 32. By mixing the citric acid solution and the sodium bicarbonate solution, a chemical reaction is started which produces gaseous CO ₂ according to the following formula:

6(NaHCO ₃ ) + 2(C ₆ H ₈ O ₇ ) -» 2(Na ₃ C ₆ H ₅ O ₇ ) + 6(CO ₂ ) + 6(H ₂ O)

The CO ₂ produced by the chemical reaction described above is transported via the pressurising hose 38 into the beverage container 12. The CO ₂ will carbonate the beverage stored in the beverage container 12, i e. the CO ₂ will dissolve in the beverage. The CO ₂ will as well build a pressure inside the beverage container of about 0.5 - 1 bar above the pressure outside the beverage container 12.

Fig, 1c shows the beverage dispensing system 10 as described above while dispensing the beverage. By operating the handle 24 in the direction of the arrow indicated in the figure, the tapping valve 22 is shifted from a closed position to an open position, which allows beverage to enter the tapping line 20 and leave the beverage dispensing system 10 through the beverage tap 26. The beverage is collected in a glass 42 The pressure caused by the production of CO ₂ will cause the beverage to flow through the tapping line 20 towards the outside of the beverage dispensing system 10. When one serving of beverage has been collected in the glass 42, the handle 24 may be returned, i.e. operated in the direction opposite the arrow indicated in the figure, which causes the tapping valve 22 to assume the closed position and thereby interrupt the beverage flow out of the beverage dispensing system 10

Figs. 2a, 2b and 2c show a beverage dispensing system 1Q\ The beverage dispensing system 10' includes all of the features of the beverage dispensing system 10 described above in connection with Fig. 1 with the difference that the beverage in the beverage container 12 constitutes a pre-carbonated beverage and the CO ₂ produced by the chemical reaction is used only to pressurise the beverage container 12 for the purpose of dispensing the beverage through the tapping line 20.

Fig 3a shows a beverage dispensing system 10" including a double-layered beverage container constituting a flexible inner beverage container 12' and a rigid outer container 13. The beverage container 12' contains a non-pre-carbonated beverage. The beverage dispensing system 10" comprises all of the features of the beverage dispensing system 10 described above in connection with Fig. 1 and additionally includes a carbonating valve 44 and an auxiliary pressurising hose 46 The carbonating valve 44 is located on the pressurising hose 38 which is connecting the pressure generator 28 and the beverage container 12 ¹ The auxiliary pressurising hose 46 connects the carbonating valve 44 and the outer container 13. The tapping line 20' in the present embodiment does not constitute an ascending pipe since the beverage will be forced against the beverage outlet 14 due to the pressure against the flexible beverage container 12'.

Fig. 3b shows the beverage dispensing system 10" while carbonating the beverage included in the inner container 12' The carbonating valve 44 is set to deliver CO2 to the inner container 12' for carbonating the beverage.

Fig. 3c shows the beverage dispensing system 10" while dispensing beverage. The carbonating valve 44 is set to deliver CO ₂ to the outer container 13 via the auxiliary pressurising hose 46. By operating the handle 24, the beverage will flow out of the beverage container 12' via the tapping line 20' towards the beverage tap 26 As the beverage is being dispensed, the inner container 12' will collapse due to the pressure in the outer container 13. The carbonating valve 44 optionally includes a pressure reduction valve for allowing some CO ₂ to enter the inner container 12' for carbonating the beverage while dispensing and compensates for losses in carbonisation, which might occur during storage.

Figs 4a, 4b and 4c show a beverage dispensing system 10"' including a double- layered beverage container constituting a rigid outer container 13 and a flexible inner container 12' containing a pre-carbonated beverage. The beverage dispensing system 10'" includes all the features of the previously described beverage dispensing system 10" with the difference that the pressurising hose 38 connects the pressure generator 28 and the outer container 13 for providing a pressure in the outer container 13 for dispensing the beverage. As the beverage is dispensed, the pressure in the outer container 13 will cause the inner container to collapse.

Fig. 5a shows a beverage dispensing system 50 with chemical carbonating and mechanical pressurisation. The beverage dispensing system 50 comprises a housing 52 for accommodating a singie-layered flexible beverage container 54. The flexible beverage container 54 is accommodated in a lower sealed space 56 of the housing 52 The lower sealed space 56 further comprises a compressor 58. The housing 52 further comprises an upper space 60 for accommodating the pressure generator 28 as previously described in connection Fig, 1 The upper space 60 further comprises the tapping line 20, the tapping valve 22 and the beverage tap 26 as previously described in Fig, 1a

Fig. 5b shows the beverage dispensing system 50 while carbonating the beverage contained in the beverage container 54. The CO ₂ is transported into the beverage container 54 by the pressurising hose 38.

Fig. 5c shows the beverage dispensing system 50 while dispensing beverage. The compressor 58 provides a high air pressure inside the lower space, which causes the beverage container 54 to collapse while dispensing the beverage.

Fig. 6a shows a beverage can 62 The beverage can 62 accommodates a non-pre- carbonated beverage and a widget 28' constituting a pressure generator located at the bottom of the beverage can 62, The widget 28' is located at the bottom of the beverage can 62 and comprises an upper compartment 30' comprising a mixture of water and citric acid, and a lower compartment 32' comprising a mixture of water and sodium bicarbonate. The upper and Sower compartments 30', 32' are separated by a rupturable membrane 34', which is connected to a piercing element 36'. The lower compartment 32' is significantly smaller than the upper compartment 30', and the total amount of liquid inside the widget 28' comprises less than 50% of the total volume of the widget 28' The widget further comprises a pressurizing hose 38' connecting the central interior space of the widget 28' and the beverage in the beverage can 62 outside the widget 28'.

The beverage can 62 has a slight overpressure. When the beverage outlet 14' of the beverage can 62 is sealed, the pressure inside the beverage can wili cause the piercing element 36' to remain in an inwardly oriented position and the widget 28' to remain in a pre-activation stage,

Fig. 6b shows the beverage can 62 when the beverage outlet 14' of the beverage can 62 has been opened The abrupt loss of pressure in the beverage can caused by the opening of the beverage can 62 causes the piercing element 36' to switch to an outwardly oriented position, thereby rupturing the rupturable membrane separating the lower compartment 32 ⁽ and the upper compartment 30', The widget 28' will thus be in the post-activation stage when the membrane between the upper and the lower compartments 32', 30' is ruptured which causes the widget 28' to produce CO ₂ . The CO ₂ released by the pressure generator 28 carbonates the beverage via the pressurising hose 38'.

Fig, 6c shows the beverage being poured out of the beverage can 62 by pivoting the beverage can 62 towards a glass 42. Due to the centrally located pressurizing hose 38' and liquid inside the widget 28' comprising less than 50% of the total volume of the widget 28', liquid will not leave the widget 28'

Fig. 7 shows a self-regulating pressure generator 70 for use with the beverage dispensing system as described above in connection with Figs. 1-6. The pressure generator 70 comprises a first compartment 72 and a second compartment 74. The first compartment 72 is filled with a citric acid solution constituting a mixture of water and citric acid. The second compartment 74 is filled with a sodium bicarbonate solution constituting a mixture of sodium bicarbonate and water. The first compartment and the second compartment further comprise a first fluid outlet 76 and a second fluid outlet 78, respectively. The first and second fluid outlet 76, 78 are controlled by a common sealing member 80 The sealing member 80 defines a closed position in which the citric acid solution and the sodium bicarbonate solution are prevented to leave the first compartment 72 and the second compartment 74, respectively, via the first fluid outlet 76 and the second fluid outlet 78, respectively. The sealing member 80 may be shifted to define an open position in which the citric acid solution and the sodium bicarbonate solution are allowed to leave the first compartment 72 and the second compartment 74, respectively, via the first fluid outlet 76 and the second fluid outlet 78, respectively

When the sealing member 80 is in the open position, citric acid solution and sodium bicarbonate solution may leave the first compartment 72 and the second compartment 74, respectively, and enter a pressure space 82 located within the self-regulating pressure generator 70. The pressure space 82 accommodates a mixing sponge 84 for receiving the citric acid solution and the sodium bicarbonate solution from the first fluid outlet 76 and the second fluid outlet 78, respectively. By mixing the citric acid solution and the sodium bicarbonate solution within the mixing sponge 84, gaseous CO ₂ is generated within the pressure space 82, The pressure space 82 further comprises a gas outlet 86 which may be connected to a beverage dispensing system or beverage container, optionally via a pressurising hose as described above in connection with Figs, 1-6. The pressure space 82 further comprises a flexible membrane 88 for separating the pressure space 82 from an ambient pressure space 90 which is in fluid communication with the outside of the self-regulating pressure generator 70 via a hole 92^ The flexible membrane is preferably made of a flexible and pressure-tight material such as rubber

The sealing member 80 is attached to the flexible membrane 88 such that the sealing member 80 may shift between the open and the closed position according to the movement of the flexible membrane 88. When the pressure increases in the pressure space 82, the flexible membrane 88 will bend in an outward direction towards the ambient pressure space 90 due to the pressure acting on the flexible membrane 88 The sealing member 80 will consequently shift from the open position to the closed position, since the sealing member 80 is fixated to the flexible membrane. When the sealing member is in the closed position, the supply of citric acid solution and sodium bicarbonate solution to the mixing sponge will stop, and consequently the chemical reaction producing CO ₂ will stop.

When the pressure in the pressure space 82 is reduced, e.g due to beverage dispensing operations or leakage, the flexible membrane will bend inward towards the pressure space 82, thereby causing the sealing member to assume the open position supplying citric acid solution and sodium bicarbonate solution to the mixing sponge 84, thus starting the chemical reaction for producing CO ₂ . In this way the pressure is automatically regulated.

Fig. 8 shows an alternative embodiment of the self-regulating pressure generator 70' The pressure generator 70' has the same features as the pressure generator 70 with the difference that only one compartment 72' is provided. The compartment 72' is filled with the sodium bicarbonate solution The citric acid is provided as a solid granulate inside the mixing sponge 84', As the bicarbonate solution enters the mixing sponge 84' as described above in connection with Fig. 7, the solid citric acid granulate will dissolve in the sodium bicarbonate solution and the chemical reaction for producing CO ₂ will start.

Fig. 9 shows yet another embodiment of the self-regulating pressure generator 70". The self-regulating pressure generator 70" comprises a first compartment 72" which is filled with a sodium bicarbonate solution, The first compartment 72" is connected to a second compartment 74' via a fluid outlet 76 ¹ The second compartment 74' contains a citric acid solution. The second compartment 74' is connected to a pressure space 82' via a hoie 85. The pressure space 82' may in turn be connected to a beverage dispensing system as described above in connection with Figs, 1-6 via a gas outlet 86.

The pressure space 82' further comprises a spring-loaded piston 88' separating the pressure space 82' from an ambient pressure space 90'. The ambient pressure space 90' is connected to the ambient pressure outside of the self-regulating pressure generator 70" via an opening 92. When the pressure in the pressure space decreases, the spring-loaded piston 88' wili move in an inward direction towards the pressure space 82'. The spring-loaded piston 88' is connected to a feeding piston 87 via a feeding arrangement 89.

The feeding arrangement 89 constitutes a first and a second beam positioned juxtaposed in relation to each other and being connected to the spring-loaded piston 88' and the feeding piston 87, respectively. The first and the second beam are having oppositely arranged triangular protrusions such that the feeding arrangement 89 defines an inward catching direction and an outward sliding direction When the pressure in the pressure space 82' is reduced, the spring-loaded piston 88' will move a specific distance in the inward direction and the feeding piston 87 will move substantially the same distance in the same inward direction as the spring-loaded piston 88'. The feeding piston 87 will compress the first compartment 72" and force the sodium bicarbonate solution stored in the first compartment 72" to flow into the second compartment 74' via the fluid outlet 76' and start the chemical reaction for producing CO ₂ which will in turn increase the pressure in the pressure space 82' which will cause the spring-loaded piston 88' to move in the outward direction towards the ambient pressure space 90 ¹ The feeding arrangement 89 will allow the spring-loaded piston 88' to move in the outward direction while maintaining the feeding piston 87 in an unchanged position.

Fig. 10 shows a further embodiment of the self-regulating pressure generator 70'" having all of the features of the pressure generator 70", however, instead of a liquid bicarbonate solution, a solid sodium bicarbonate granulate is used. The solid sodium bicarbonate granulate is pushed by the second piston as described above in connection with Fig. 9 into a citric acid solution stored in the second compartment 74'. The sodium bicarbonate granulate will dissolve in the citric acid solution and start the chemical reaction for producing CO ₂ .

Fig. 1 1 shows an alternative embodiment of the self-regulating pressure generator 70"", having all of the features of the self-regulating pressure generator 70'" described above with the difference that the sodium bicarbonate granulate has been replaced by a sodium bicarbonate paste The sodium bicarbonate paste may be achieved by adding a small amount of aqueous solution to the sodium bicarbonate granulate. The sodium bicarbonate paste will have better flow properties compared to the sodium bicarbonate granulate.

Fig 12 shows an alternative embodiment of the self-regulating pressure generator 70""', having all of the features of the self-regulating pressure generator 70"" described above with the difference that the citric acid solution has been replaced by a citric acid solution paste The citric acid paste may be achieved by adding a small amount of aqueous solution to a citric acid granulate, A further feeding piston

87' and feeding arrangement 89' are provided for feeding the citric acid paste. Both the citric acid paste and the sodium bicarbonate paste are fed towards a centrally located mixing chamber, where the citric acid paste and the sodium bicarbonate paste are allowed to mix and start producing CO ₂ . Fig. 13 shows an on demand pressure generator 71 comprising all of the parts of the self-regulating pressure generator 70, except that the flexible membrane 88 has been removed and the sealing member 80' has been connected to a handle 24 of a tapping valve 22 located outside the on demand pressure generator 71. The sealing member 80' extends from the pressure space 82 to the outside of the on demand pressure generator 71 via a sealing 92'.

Fig. 14 shows the on demand pressure generator 71 according to fig 13 when the handle 24 is being operated to dispense beverage. The handle 24 is connected to the tapping valve 22, which is in turn connected to the pressurised beverage container or beverage dispensing system (both not shown) via a tapping line 20 as described above in connection with Figs. 1-6. While the beverage flows out of the beverage tap 26 via the tapping line 20 the sealing member 80' is shifted to define an open position in which the citric acid solution and the sodium bicarbonate solution are allowed to leave the first compartment 72"" and the second compartment 74"", respectively, via the first fluid outlet 76 and the second fluid outlet 78, respectively

When the sealing member 80' is in the open position, citric acid solution and sodium bicarbonate solution may leave the first compartment 72"" and the second compartment 74"", respectively, and enter the pressure space 82 located within the on demand pressure generator 71. The pressure space 82 accommodates a mixing sponge 84 for receiving the citric acid solution and the sodium bicarbonate solution from the first fluid outlet 76 and the second fluid outlet 78, respectively. The amount of sodium bicarbonate solution and citric acid allowed to enter the pressure space should be determined to generate a gas volume approximately corresponding to the amount of dispensed beverage.

By mixing the citric acid solution and the sodium bicarbonate solution within the mixing sponge 84, gaseous CO ₂ is generated within the pressure space 82. The pressure space 82 further comprises a gas outlet 86 which may be connected to the beverage container or beverage dispensing system (both not shown), optionally via a pressurising hose as described above in connection with Figs. 1-6 When the handle 24 is returned, the sealing member 80' returns as well to prevent the citric acid solution and the sodium bicarbonate solution from leaving the first compartment 72"" and the second compartment 74"". Thereby the CO ₂ production is interrupted

Fig 15 shows an on demand pressure generator 71 comprising all of the parts of the self-regulating pressure generator 70, for use with a sodium bicarbonate paste as described in connection with Fig 11 The sealing member has been replaced by a feeding piston 87 and a feeding arrangement 89 as described in connection with Fig. 10

Although the present invention has been described above with reference to specific embodiments of the Cθ ₂ -generating device and also specific embodiments of the beverage dispensing system, it is of course contemplated that numerous modifications may be deduced by a person having the ordinary skill in the art, and modifications readily perceivable by a person having ordinary skill in the art is consequently to be construed as part of the present invention as defined in the appended claims.

List of parts with reference to the figures

10. Beverage dispensing system 52, Housing

12. Beverage container 54, Beverage container

13. Outer container 56. Lower sealed space

14. Beverage outlet 58 Compressor

16. Outward protruding flanges 60. Upper space

17. Inward protruding flanges 62 Beverage can

18. Closure 70. Self-regulating pressure generator 20, Tapping line 71. On demand pressure generator 22. Tapping valve 72 First compartment 24. Handle 74, Second compartment 26. Beverage tap 75 Mixing chamber 28, Pressure generator 76 First fluid outlet 30, Upper compartment 78. Second fluid outlet 32. Lower compartment 80. Sealing member 34. Membrane 82. Pressure space 36. Piercing element 84. Mixing sponge 38. Pressurising hose 86 Gas outlet 40. Filler 87 Feeding piston 42. Beverage glass 88, Flexible membrane/spπng-loaded piston 44. Carbonating valve 89. Feeding arrangement 46. Auxiliary pressurising hose 90. Ambient pressure space 50 Beverage dispensing system 92, Hole / sealing / opening