GB2454904A

GB2454904A - Carbon dioxide recovery beer dispensing system

Info

Publication number: GB2454904A
Application number: GB0722926A
Authority: GB
Inventors: Tom Oswald
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-22
Filing date: 2007-11-22
Publication date: 2009-05-27
Also published as: GB0722926D0

Abstract

Container pressurisation apparatus 1 comprising a container 2, a pressure fluid, such as carbon dioxide or a mixture of carbon dioxide and nitrogen, compressor means 3 and control means, in which in a first configuration the control means is adapted to direct the pressure fluid to the container such that a pressure function is performable therein, in which in a second configuration the control means is adapted to vent used pressure fluid from inside the container and direct it to the compressor means, in which the compressor means is adapted to compress the used pressure fluid to a pressure at or above that required to perform said pressure function, and in which in the first configuration some or all of the pressure fluid directed to the container comprises used pressure fluid compressed by the compressor means. The used pressure fluid that has been compressed may then be subjected to filter means and drying means, and the control means may comprise an electronic control circuit 23.

Description

Container Pressurisation Apparatus This invention relates to container pressurisation apparatus, for use particularly, but not exclusively, to pressurise barrels of beer.

Beer is usually contained in a barrel in a basement, which is connected by a line to a tap at a bar above. The barrel is pressurised to about 30 psi (2.07 Bar) with a nitrogen and carbon dioxide gas mix, such that the beer is forced up the line and can flow out of the tap. During this process the beer is replaced inside the barrel with the compressed gas. When all the beer has been dispensed the barrel is removed from the line and returned to the brewery where the compressed gas is vented to atmosphere, before the barrel is cleaned and refilled with beer.

This process is wasteful because it requires considerable energy to compress the gas in the first place, but only a small percentage of that energy is used in the process of dispensing the beer, before the rest is simply lost. As such, a large part of the high cost of manufacturing and purchasing the compressed gas is redundant.

This may not be a real problem on an individual basis, but it is certainly a problem when a large number of beer barrels are used at a large pub, because the cost of the compressed gas can be tens of thousands of pounds a year. The problem is greater still if considered on a national or global scale.

In addition, this process is damaging to the environment because carbon dioxide is added to the atmosphere when it is vented from the drained barrels, which contributes to global warming. In the UK alone more than 17,000 tons of manufactured carbon dioxide a year are vented to the atmosphere from used beer barrels. In addition, the industrial scale production of this compressed gas, which as stated above is largely redundant, also has an impact on the environment in the form of carbon emissions.

The present invention is intended to overcome some of the above problems.

Therefore, according to a first aspect of the present invention container pressurisation apparatus comprises a container, a pressure fluid, compressor means and control means, in which in a first configuration the control means is adapted to direct the pressure fluid to the container such that a pressure function is performable therein, in which in a second configuration the control means is adapted to vent used pressure fluid from inside the container and direct it to the compressor means, in which the compressor means is adapted to compress the used pressure fluid to a pressure at or above that required to perform said pressure function, and in which in the first configuration some or all of the pressure fluid directed to the container comprises used pressure fluid compressed by the compressor means.

Therefore, the apparatus of the present invention recovers the used pressure fluid, reconditions it, and uses it again. When the invention is applied to a beer dispensing system the compressed gas inside the beer barrel which would otherwise simply be vented to atmosphere is reconditioned and reused without being wasted.

It will be appreciated that while the invention is preferably applied to a beer or other beverage dispensing system, it can be applied to any system which uses a pressure fluid to perform a pressure function inside a container. This could include any number of industrial arrangements, including any type of compressed gas driven pistons or actuators, of which there are a very large number of different types with different applications. In such cases the would be the cylinder or equivalent structure which is pressurised in order for a component therein to move or change state. The first configuration would relate to a positive action, and the second configuration would relate to a negative action, which would normally involve compressed gas being either vented or diverted away.

In a preferred construction the apparatus can be provided with a supply of pressure fluid, and in a priming configuration the control means can be adapted to direct pressure fluid from the supply to the container such that a pressure function is performable therein. In the first configuration if there is insufficient used pressure fluid to make up all the pressure fluid required to perform the pressure function in the container, then the control means can be adapted to direct pressure fluid from the supply to the container to make up the shortfall.

Thus, a beer dispensing system can be provided with a compressed gas cylinder of the known type in order to prime the system, and to provide additions to the recycled compressed gas, which will prove necessary as energy is used each time a barrel of beer is dispensed. This usage of fresh compressed gas will obviously be far less than that which is used in known systems.

The pressure function performed in the container can be finite, and the container can be a consumable to be replaced when the pressure function is complete. Barrels of beer which require a finite quantity of compressed gas for the beer within them to be dispensed, are obviously consumable items which are replaced once they are empty. To allow for this the apparatus can have a stand-by configuration in which the container can be removed from the apparatus and replaced with another container requiring the pressure function to be performed therein.

The control means can comprise a function sensor adapted to detect when the pressure function has been completed in the container, and when the function sensor detects that this is the case the apparatus can be switched to the second configuration and / or the stand-by configuration. There are various types of sensor which could achieve this function, but when the container is a beer barrel the function sensor can be an optical sensor.

In a preferred construction a fluid reservoir can be provided downstream of the compressor means, and the control means can comprise a first pressure sensor adapted to detect the pressure of used pressure fluid stored in the fluid reservoir.

When the first pressure sensor detects that the used pressure fluid in the reservoir has reached a pressure at which it is adapted to perform the pressure function, the apparatus can be switchable to the first configuration. Likewise, when the first pressure sensor detects that the used pressure fluid in the reservoir has dropped below a pressure at which it is adapted to perform the pressure function, the control means can be adapted to direct pressure fluid from the supply to the container to make up the shortfall.

Preferably the compressor means can compress the used pressure fluid to a pressure much higher than that required to perform the pressure function, because the higher the pressure the smaller the area required to store it. Therefore, for most of the time that used pressure fluid is present in the reservoir it is stored at a pressured which is more than sufficient to perform the pressure function. Fluid pressure regulators can be provided between the fluid reservoir and the container, which can be adapted to reduce the pressure of the used pressure fluid to the correct pressure to perform the pressure function prior to entering the container.

The apparatus of the invention can be arranged such that it merely indicates when the configuration needs to be changed, and a user can change the configuration manually. However, in a preferred embodiment when the function sensor detects that the pressure function has been completed the control means can switch the apparatus to the second configuration and / or the stand-by configuration automatically. Likewise, when the first pressure sensor detects that the used pressure fluid in the reservoir has reached a pressure at which it is adapted to perform the pressure function, the control means can switch the apparatus to the first configuration automatically.

In order to perform the above changes in configuration, the control means can comprise a first 3/2 valve adapted to allow pressure fluid to enter the container in the priming configuration and the first configuration, and to allow used pressure fluid to vent from the container in the second configuration. Further, the control means can also comprise a second 3/2 valve adapted to direct used pressure fluid in the reservoir to the container in a first position, and to direct pressure fluid from the supply to the container in a second position.

The control means can also comprise a second pressure sensor provided between the container and the compressor means, which can be adapted to detect pressure fluid vented from the container in the second configuration, and when it does the compressor means can be operated. As such, the compressor means is automatically operated a short time after the apparatus is switched to the second configuration. Likewise, when all the pressure fluid has been removed from the container the compressor means is automatically stopped.

In a preferred construction the used pressure fluid compressed by the compressor means can be subjected to a filter means before it is directed to the container. The filter means can be any device which performs a filtering function, but in most cases it will be one or more mesh filters. This feature is important when the invention is applied to a beer dispensing system, as the gas directed to a barrel containing beer to be dispensed must not contain contaminants from the previous barrel. In addition to this filter means, the pressure fluid can be subjected to a drying means before it is directed to the container to ensure it is completely moisture free.

As referred to above, the pressure fluid used to pressurise and dispense beer is a mixture of carbon dioxide and nitrogen. Commonly these gases are provided at a ratio of 40 per cent to 60 per cent, although it can vary from product to product. In one version of the invention applied to a beer dispensing system the gas which is removed from the beer barrel is simply recycled and used again, without the ratio being checked or changed. In most cases this is sufficient.

However, in one version of the invention the pressure fluid can comprise a mixture of a first fluid and one or more second fluids, and the control means can comprise a first fluid concentration analysing means downstream of the compressor means, adapted to detect the concentration of the first fluid in the used pressure fluid compressed by the compressor means. Further, the apparatus can comprise a first fluid concentration adjustment means adapted to adjust the used pressure fluid such that it comprises a predetermined concentration of the first fluid.

The first fluid concentration adjustment means can comprise a second fluids removal mechanism, such that the correct ratio of fluids is achieved by removing a quantity of the second fluids. However, preferably the adjustment means can comprise instead a supply of the first fluid. As such, the control means can be adapted to direct first fluid from the supply of the first fluid to the used pressure fluid compressed by the compressor means until it comprises the predetermined concentration of the first fluid.

As an alternative to the above arrangement, in another embodiment of the invention the pressure fluid can comprise a mixture of two or more fluids, and the control means can comprise a pressure fluid dividing means adapted to divide the used pressure fluid compressed by the compressor means into its constituent fluids.

The control means can further comprise a fluid blender adapted to blend said constituent fluids into a predetermined mixture.

This arrangement is more complex, but it allows the ratio of fluids to be readily changed to suit different beverages. For example, if a first beer is dispensed using a 40/60 carbon dioxide and nitrogen mix, but the beer in a replacement barrel requires a 50/50 mix, the control means can provide a gas at the correct mixture by blending the two separate gases in the correct proportion.

As described above the invention can be applied to any type of container pressurisation apparatus, but preferably the container can be adapted to carry a drink, and the pressure function can be the pressurisation of the drink in the container for the purpose of dispensing it therefrom.

It will be appreciated that most beer dispensing systems comprise a plurality of beverage barrels all working along side one another. Therefore, the apparatus can comprise two or more containers, and it can be arrangeable in the first configuration and the second configuration separately for each of the two or more containers. In addition, the apparatus can also be arrangeable in the priming configuration and the stand-by configuration separately for each of the two or more containers.

With such a set up the recycled gas can be used for any of the beer barrels in the system. For example, the gas removed from a first container and recycled may be directed to a second container along side it, and not to a container which replaces the first.

It will be appreciated that the above described invention could be applied to an existing beer dispensing system. Therefore, according to a second aspect of the present invention container pressurisation apparatus comprises compressor means and control means, which apparatus is only for use in creating a container pressurisation apparatus comprising a container, a pressure fluid and said compressor means and control means, in which in a first configuration the control means is adapted to direct the pressure fluid to the container such that a pressure function is performable therein, in which in a second configuration the control means is adapted to vent used pressure fluid from inside the container and direct it to the compressor means, in which the compressor means is adapted to compress the used pressure fluid to a pressure at or above that required to perform said pressure function, and in which in the first configuration some or all of the pressure fluid directed to the container comprises used pressure fluid compressed by the compressor means.

The invention can be performed in various ways, but one embodiment will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic display of a container pressurisation apparatus according to the first aspect of the present invention, in the first configuration; Figure 2 is a diagrammatic display of the container pressurisation apparatus as shown in Figure 1, in the second configuration; Figure 3 is a diagrammatic display of the container pressurisation apparatus as shown in Figure 1, in an alternative first configuration, or the priming configuration; and Figure 4 is a diagrammatic display of the container pressurisation apparatus as shown in Figure 1, in which different parts are in different configurations.

As shown in Figure 1 container pressurisation apparatus, in the form of beer pressurising system 1, comprises a container, in the form of first beer barrel 2, a pressure fluid in the form of a carbon dioxide and nitrogen gas, compressor means, in the form of compressor 3 and control means, which is explained in more detail below. In a first configuration, as shown in Figure 1, the control means is adapted to direct the gas to the first beer barrel 2 such that a pressure function is performable therein, in the form of the pressurisation of a beer in the first beer barrel 2 such that it is forced up line 4, and can be dispensed from tap 5. In a second configuration, as shown in Figure 2, the control means is adapted to vent used gas from inside the first beer barrel 2 and direct it to the compressor 3. The compressor 3 is adapted to compress the used gas to a pressure at or above that required to perform said pressure function. In the first configuration some or all of the gas directed to the first beer barrel 2 comprises used gas compressed by the compressor 3.

The beer pressurising system 1 shown in the Figures comprises four beer barrels and associated components. In particular, second beer barrel 6 feeds line 7 so beer can be dispensed from tap 8, third beer barrel 9 feeds line 10 so beer can be dispensed from tap 11, and fourth beer barrel 12 feeds line 13 so beer can be dispensed from tap 14. Each beer barrel, 2, 6, 9 and 12 is connectable to a gas feed line 15 when first, second, third and fourth 3/2 valves 16, 17, 18 and 19 respectively, are arranged in a first position, as shown in Figure 1. In addition, each beer barrel 2, 6, 9 and 12 is connectable to a gas recycling ring 20 when the first, second, third and fourth 3/2 valves 16, 17, 18 and 19 respectively, are arranged in a second position. (The first 3/2 valve 16 is arranged as such in Figure 2.) The gas feed line 15 leads from a fifth 3/2 valve 21, which feeds gas thereto from either the gas recycling ring 20 in a first position as shown in Figure 1, or a source of gas from a pressuriseci canister 22 in a second position as shown in Figure 2.

The control means.comprises an electronic control circuit 23, which is contained in a control box 24, which has an LED screen 25 to display information, and a keypad 26 to input commands. The control circuit 23 is provided with a database of information 27. (The control circuit 23 is constructed and operates according to known principals and the man skilled in the art would be capable of building and programming it to perform all the functions described below. Therefore, the control circuit and its various parts are not further described here.) The control circuit 23 is connected to each of the 3/2 valves 16, 17, 18, 19 and 21, and can control their positions with electrical signals. The control circuit 23 is also connected to optical sensors 28, 29, 30 and 31 which are adapted to detect the presence of beer in the first, second, third and fourth beer barrels 2, 6, 9, and 12 respectively, and to communicate what they detect to the control circuit 23. In addition, the control circuit 23 is connected to first pressure sensor 32 and second pressure sensor 33, which both communicate the detected pressure at their respective positions in the gas recycling ring 20 to the control circuit 23. The control circuit 23 is also connected to the compressor 3, and can switch it on and off.

In addition to the compressor 3 and the pressure sensors 32 and 33, the gas recycling ring 20 also comprises a reservoir 34, a gas regulator 35 and a filter 36.

Each of the beer barrels 2, 6, 9, and 12 is a consumable item, and is attached to the beer pressurising system 1 by a standard fitting 37, 38, 39 and 40 respectively, which allows it to be removed therefrom, and replaced with another.

(The diagrams shown in the Figures are merely diagrammatic and are not intended to show any of the physical features of the above described components, or their physical location. In addition, various other components may be required to make the system operate in practice, such as non-return valves, further gas regulators, power supplies and other sensors. However, these other components are known, and the man skilled in the art could include them according to their general knowledge of the art.) The beer pressurising system 1 can perform the same basic functions for each of the beer barrels 2, 6, 9 and 12 separately, although the manner of operation when two or more beer barrels are used is more complex than when only one is fitted. In order to describe the basic functions of the system 1 the following description assumes that only first beer barrel 2 is used, and a description of multi-beer barrel use is given thereafter.

Before the system 1 can operate according to the invention, it must be primed. Referring to Figure 3, first beer barrel 2 is fitted to the system 1 via the fitting 37, and the control circuit 23 is manually set to a priming configuration using the keypad 26. Once these instructions are received, the control circuit 23 switches the first 3/2 valve 16 to its first position, if it is not in that position already, and the fifth 3/2 valve 21 to its second position. As such a gas path is opened between the canister 22 and the first beer barrel 2, and the beer therein is pressurised by the 40 per cent carbon dioxide and 60 per cent nitrogen gas from the canister 22. The first beer barrel 2 is pressurised to 30 psi (2.07 Bar), such that beer therein is forced up the line 4 and can be dispensed from the tap 5, as normal. Beer is then dispensed from the tap 5 over a period of time, and the first beer barrel 2 drains of beer, and fills with gas from the canister 22.

When the first beer barrel 2 is empty of beer the optical sensor 28 sends a signal to the control circuit 23, and the control circuit 23 automatically switches the system I to the second configuration, as shown in Figure 2. The control circuit 23 sends a signal to the first 3/2 valve 16 to assume its second position, and as such the gas path from the canister 22 to the first beer barrel 2 is closed off, and a gas path from the first beer barrel 2 to the gas recycling ring 20 is opened. The used gas inside the first beer barrel 2 is vented therefrom and enters the gas recycling ring 20.

As a result of this the second pressure sensor 33 detects an increase in pressure, and sends a signal to the control circuit 23. When this signal is received the control circwt 23 switches on the compressor 3.

The compressor 3 compresses the used gas from the first beer barrel 2 to psi (10 Bar). As such, the compressor 3 actually draws the used gas from the first beer barrel 2. When the second pressure sensor 33 detects that the pressure at its point in the gas recycling ring 20 has dropped to zero it sends a signal to the control circuit 23. When this signal is received the control circuit 23 switches the compressor 3 off. As such, no vacuums are generated in the system 1. The compressed gas exiting the compressor 3 is directed to the reservoir 34, where it is stored.

At this point the first beer barrel 2 is removed from the system 1 and replaced with another, which is full of beer to be dispensed. The fitting 37 is adapted to prevent any gas from the system 1 escaping when the first beer barrel 2 is removed, and as such the first beer barrel 2 can be safely removed at any time whatever the status of the first 3/2 valve 16. However, in addition to this (or as an alternative) the control circuit 23 can be adapted to automatically, or via manual input through the keypad 26, switch the system 1 to a stand-by configuration. To do this the control circuit 23 sends a signal to the first 3/2 valve 16 to assume a third intermediate position in which both the gas feed line 15 and the gas recycling ring 20 are shut off.

(Second 3/2 valve 17 is shown in this position in Figure 4.) In such an arrangement no gas will vent from the system 1 if the first beer barrel 2 is removed therefrom.

When a replacement first beer barrel 2 is fitted, a command to the control circuit 23 is entered via the keypad 26, and the control circuit 23 switches the first 3/2 valve 16 back to the first position, as shown in Figures 1 and 3, so gas can be directed to the first beer barrel 2 from the gas feed line 15.

Now the system is fully primed and ready to operate according to the invention, because a quantity of recycled gas is contained in the reservoir 34, which can be directed to the new first beer barrel 2. The first pressure sensor 32 detects the pressure of the gas in the reservoir 34, and this is communicated to the control circuit 23. The database 27 contains data on the pressure inside the reservoir 34 which must be reached for the gas therein to be capable of pressurising the first beer barrel 2. At first the pressure inside the reservoir is in excess of that which is required, but as the recycled gas is used up the pressure drops, and when it drops below the required pressure it can no longer be used.

While the first pressure sensor 32 indicates that the gas in the reservoir 34 is at or above the sufficient pressure, the control circuit 23 switches the fifth 3/2 valve 21 to its first position, as shown in Figure 1. As such a gas path is opened from the reservoir 34 to the first beer barrel 2, and the beer therein is pressurised by the recycled gas. The recycled gas passes through the regulator 35 to regulate its pressure to 30 psi, and over the filter 36 to remove contaminants and ensure the gas is sufficiently pure to mix with the beer in the first beer barrel 2.

When the first pressure sensor 32 indicates that the gas in the reservoir 34 has dropped below the sufficient pressure, the control circuit 23 switches the fifth 3/2 valve 21 to its second position, as shown in Figure 3. As such a gas path is opened between the canister 22 and the first beer barrel 2, and the fresh gas from the canister 22 is used to supplement the recycled gas.

Regardless of the source of the pressurising gas, beer is dispensed from the tap 5 over a period of time, and the first beer barrel 2 drains of beer, and is left filled with a mixture of recycled and fresh gas. At this point the optical sensor 28 sends a signal to the control circuit 23 and the whole recycling process described above is performed again.

Therefore, it can be seen how the system 1 operates in principal with one beer barrel, however the system 1 comprises four beer barrels 2, 6, 9,and 12, and when all four are used the manner of operation is slightly different.

In particular, when the system is first used all four beer barrels 2, 6, 9, and 12 are simultaneously primed using gas from the canister 22. However, the beer barrels 2, 6, 9, and 12 will drain at different rates, and the gas which is recycled is used in a common manner rather than in a separate isolated manner. In particular, as soon as one of the beer barrels 2, 6, 9, or 12 is drained the used gas will be automatically vented therefrom and compressed, as described above. As soon as the first pressure sensor 32 indicates that usable recycled gas is present in the reservoir 34, the control circuit 23 will switch the fifth 3/2 valve 21 to its first position and the recycled gas can be used immediately to pressurise the three remaining beer barrels, regardless of whether or not the first beer barrel to drain has been replaced yet.

Each time a beer barrel 2, 6, 9 or 12 is drained the used gas is recycled, and the reservoir 34 could contain gas sourced from any of the beer barrels 2, 6, 9, or 12, and it can be used to pressu rise any of them alone, or simultaneously with any of the others.

In order to illustrate this, Figure 4 shows the system 1 at a complex point of operation. The first and third beer barrels 2 and 9 contain a quantity of beer to be dispensed from the taps 5 and 11 respectively. As such the first and third 3/2 valves 16 and 18 are set to their first positions. At this time the first pressure sensor 32 is indicating that gas at a sufficient pressure is present in the reservoir 34, so the control circuit 23 has automatically set the fifth 3/2 valve 21 to its first position, and used gas is being directed to the first and third beer barrels 2 and 9 to pressurise them.

However, the second and fourth beer barrels 6 and 12 have been drained and are in the process of being replaced. The second beer barrel 6 has already been completely drained of its used gas by the compressor 3, and has been removed. Prior to the removal of the second beer barrel 6, that part of the system 1 was placed in stand-by mode, and the control circuit 23 switched the second 3/2 valve 17 to its third intermediary position in which both the gas feed line 15 and the gas recycling ring 20 are shut off.

The fourth beer barrel 12 is in the process of being vented. The optical sensor 31 sent a signal to the control circuit 23 that the fourth beer barrel 12 was empty, and the control circuit 23 then switched the fourth 3/2 valve 19 into its second position. As soon as the second pressure sensor 33 detected the rise in pressure due to the use gas venting from the fourth beer barrel 12, the control circuit 23 switched on the compressor 3, as described above.

Therefore, at this point the reservoir 34 contains the used gas removed from the second beer barrel 6, and the gas currently being pumped there from the fourth beer barrel 12. As such, the first and third beer barrels 2 and 9 are currently being pressurised by a mixture of recycled gas from the second and fourth beer barrels 6 and 12.

Once a replacement second beer barrel 6 is fitted the drain on the recycled gas being provided from the reservoir 34 will increase. Likewise, when a replacement fourth beer barrel 12 is fitted the drain on the recycled gas being provided from the reservoir 34 will increase further, and in all likelihood the pressure therein will drop below the threshold, and the control circuit 23 will automatically switch the fifth 3/2 valve 21 to its first position and fresh gas from the canister 22 will be used.

Alternatively, if either of the first or third beer barrels 2 or 9 are drained before the fourth beer barrel 12 is replaced, used gas from the newly drained beer barrel will supplement that in the reservoir 34, and gas from the canister 22 may not be needed.

The second aspect of the present invention provides container pressurisation apparatus comprising compressor means and control means, which apparatus is only for use in creating a container pressurisation apparatus like the beer dispensing system 1 described above. It will be appreciated that the compressor 3 and the various components described above which make up the control means can be retro fitted to an existing beer dispensing system, and those components provide support for this aspect of the present invention.

The above described embodiment can be altered without departing from the scope of Claim 1. In particular, in one alternative embodiment (not shown) a carbon dioxide content analyzer is provided in the reservoir, which is adapted to detect the concentration of carbon dioxide in the recycled gas. In addition, a source of pure carbon dioxide is provided, which can be directed to the reservoir when a two way valve is opened. The control circuit is provided with data in its database relating to the required carbon dioxide concentration, say 40 per cent, and when the carbon dioxide content analyzer indicates that the concentration of carbon dioxide in the gas in the reservoir is less than this, the control circuit opens the two way valve and allows pure carbon dioxide into the reservoir until the carbon dioxide content analyser indicates that the concentration matches that in the database. This arrangement is advantageous because when the gas is used the carbon dioxide content tends to reduce, so the recycled gas may not be suitable for pressurising beer. This arrangement also allows for the concentrations of carbon dioxide and nitrogen in the recycled gas to be altered if required for different beverages, but only to increase the carbon dioxide content.

In another alternative embodiment (not shown) a gas dividing means is provided downstream of the compressor, which separates the carbon dioxide from the nitrogen, and separate reservoirs for carbon dioxide and nitrogen are provided. In addition, a gas blender is provided downstream of these reservoirs, which is adapted to mix the carbon dioxide and nitrogen at different ratios as required to suit different beverages. For example, if a first beer requires a 40/60 carbon dioxide and nitrogen mix, but beer in a replacement barrel requires a 50/50 mix, then the gas which is recycled from the original beer barrel can still be used to generate a certain quantity of the gas required to pressurise the replacement barrel.

In a further enhancement of the above described embodiment (not shown), a plurality of separate gas blenders are provided, each one adapted to draw carbon dioxide and nitrogen from the two reservoirs, and direct the resulting mixture to just one of a plurality of beer barrels. With this set up the system can provide separate gas mixtures as required for each barrel.

In other alternative embodiments of the invention (not shown) container pressurisation apparatus are provided in which the containers are cylinders, or equivalent structures, which are pressurised in order for a component therein to move or change state. The first configuration relates to a positive action, for example the down stroke of a piston, and the second configuration relates to a negative action, for example the return stroke of the piston. In these cases the pressure function results in a movement which is utiliseci for some industrial purpose.

In another alternative embodiment (not shown) a beer dispensing system just like system 1 is provided, but in which a drying means is provided on the gas recycling ring, which is adapted to dry the recycled gas such that it is moisture free before it is re-used.

Therefore, the apparatus of the present invention recovers used pressure fluid, reconditions it, and uses it again. This significantly cuts down on the quantity of pressure fluid required to operate the apparatus, which has large cost and environmental benefits. In addition, it also significantly cuts down on the quantity of environmentally damaging gases being vented unnecessarily to atmosphere once the pressure function has been completed.

Claims

Claims 1. Container pressurisation apparatus comprising a container, a pressure fluid, compressor means and control means, in which in a first configuration the control means is adapted to direct the pressure fluid to the container such that a pressure function is performable therein, in which in a second configuration the control means is adapted to vent used pressure fluid from inside the container and direct it to the compressor means, in which the compressor means is adapted to compress the used pressure fluid to a pressure at or above that required to perform said pressure function, and in which in the first configuration some or all of the pressure fluid directed to the container comprises used pressure fluid compressed by the compressor means.
2. Container pressurisation apparatus as claimed in Claim 1 in which the apparatus is provided with a supply of pressure fluid, and in which in a priming configuration the control means is adapted to direct pressure fluid from the supply to the container Such that a pressure function is performable therein, and in which in the first configuration if there is insufficient used pressure fluid to make up all the pressure fluid required to perform the pressure function in the container, the control means is adapted to direct pressure fluid from the supply to the container to make up the shortfall.
3. Container pressurisation apparatus as claimed in Claim 2 in which the pressure function is finite, in which the container is a consumable to be replaced when the pressure function is complete, and in which in a stand-by configuration the container is removable from the apparatus and is replaceable with another container requiring the pressure function to be performed therein.
4. Container pressurisation apparatus as claimed in Claim 3 in which the control means comprises a function sensor adapted to detect when the pressure function has been completed in the container, and in which when the function sensor detects that the pressure function has been completed the apparatus is switchable to the second configuration and / or the stand-by configuration.
5. Container pressurisation apparatus as claimed in Claim 4 in which a fluid reservoir is provided downstream of the compressor means, in which the control means comprises a first pressure sensor adapted to detect the pressure of used pressure fluid stored in the fluid reservoir, and in which when the first pressure sensor detects that the used pressure fluid in the reservoir has reached a pressure at which it is adapted to perform the pressure function, the apparatus is switchable to the first configuration.
6. Container pressurisation apparatus as claimed in Claim 5 in which when the function sensor detects that the pressure function has been completed the control means switches the apparatus to the second configuration and / or the stand-by configuration automatically, and in which when the first pressure sensor detects that the used pressure fluid in the reservoir has reached a pressure at which it is adapted to perform the pressure function, the control means switches the apparatus to the first configuration automatically.
7. Container pressurisation apparatus as claimed in any of Claims 4 to 6 in which the control means comprises a first 3/2 valve adapted to allow pressure fluid to enter the container in the priming configuration and the first configuration, and to allow used pressure fluid to vent from the container in the second configuration.
8. Container pressurisation apparatus as claimed in Claim 5 or 6, or Claim 7 when dependent on Claims 5 or 6, in which the control means comprises a second 3/2 valve adapted to direct used pressure fluid in the reservoir to the container in a first position, and to direct pressure fluid from the supply to the container in a second position.
9. Container pressurisation apparatus as claimed in any of Claims 4 to 8 in which the control means comprises a second pressure sensor provided between the container and the compressor means, which is adapted to detect pressure fluid vented from the container in the second configuration, and in which when the second pressure sensor detects pressure fluid vented from the container, the compressor means is operated.
10. Container pressurisation apparatus as claimed in any of the preceding Claims in which used pressure fluid compressed by the compressor means is subjected to a filter means before it is directed to the container.
11. Container pressurisation apparatus as claimed in Claim 10 in which used pressure fluid compressed by the compressor means is subjected to a drying means before it is directed to the container.
12. Container pressurisation apparatus as claimed in any of the preceding Claims in which the pressure fluid comprises a mixture of a first fluid and one or more second fluids, in which the control means comprises a first fluid concentration analysing means downstream of the compressor means, which is adapted to detect the concentration of the first fluid in the used pressure fluid compressed by the compressor means, in which the apparatus comprises a first fluid concentration adjustment means adapted to adjust the used pressure fluid such that it comprises a predetermined concentration of the first fluid.
13. Container pressurisation apparatus as claimed in Claim 12 in which the first fluid concentration adjustment means comprises a supply of the first fluid, and in which the control means is adapted to direct first fluid from the supply of the first fluid to the used pressure fluid compressed by the compressor means until it comprises the predetermined concentration of the first fluid.
14. Container pressurisation apparatus as claimed in any of Claim 1 to 11 in which the pressure fluid comprises a mixture of two or more fluids, in which the control means comprises a pressure fluid dividing means adapted to divide the used pressure fluid compressed by the compressor means into its constituent fluids, in which the control means further comprises a fluid blender adapted to blend said constituent fluids into a predetermined mixture.
15. Container pressurisation apparatus as claimed in any of the preceding Claims in which the container is adapted to carry a drink, and in which the pressure function is the pressurisation of the drink in the container for the purpose of dispensing it therefrom.
16. Container pressurisation apparatus as claimed in any of the preceding Claims in which the apparatus comprises two or more containers, in which the apparatus is arrangeable in the first configuration and the second configuration separately for each of the two or more containers.
17. Container pressurisatjon apparatus as claimed in Claim 16 when dependent on any of Claims 3 to 11 or 14, or Claims 12, 13 or 15 when dependent on any of Claims 3 to 11, in which the apparatus is arrangeable in the priming configuration and the stand-by configuration separately for each of the two or more containers.
18. Container pressurisation apparatus substantially as described herein and as shown in Figure 1.
19. Container pressurisation apparatus comprising compressor means and control means, which apparatus is only for use in creating a container pressurisation apparatus comprising a container, a pressure fluid and said compressor means and control means, in which in a first configuration the control means is adapted to direct the pressure fluid to the container such that a pressure function is performable

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therein, in which in a second configuration the control means is adapted to vent used pressure fluid from inside the container and direct it to the compressor means, in which the compressor means is adapted to compress the used pressure fluid to a pressure at or above that required to perform said pressure function, and in which in the first configuration some or all of the pressure fluid directed to the container comprises used pressure fluid compressed by the compressor means.