AU2001264059A1

AU2001264059A1 - Gas reclamation system

Info

Publication number: AU2001264059A1
Application number: AU2001264059A
Authority: AU
Inventors: Glyn Jones
Original assignee: Stanwell Technic Ltd
Current assignee: Stanwell Technic Ltd
Priority date: 2000-06-08
Filing date: 2001-06-08
Publication date: 2002-03-07
Anticipated expiration: 2021-06-08

Description

GAS RECLAMATION SYSTEM

The present invention relates to a gas reclamation system, particularly but not exclusively to a gas reclamation system for use in recovering carbon dioxide from kegs containing pressurised beverages.

Draught beverages such as lager and bitter beers, cider and stout are served in bars using pressurised systems. The beverage is supplied to the bar in kegs and is pressurised with carbon dioxide or a mixture of carbon dioxide and nitrogen This "top pressure" may be up to 2.81 kg cm^" (40 p.s.i.) in the case of lager beers. The latest approach to dispensing such beverages has a requirement for even higher top pressures. In order to maintain the pressure in the keg at an approximately constant level, carbon dioxide and optionally nitrogen is pumped into the keg as the beverage is supplied to the consumer. If the pressure in the keg dropped, carbon dioxide would be allowed to escape from the beverage during storage, creating foaming or fobbing of the beverage, which is undesirable. The additional carbon dioxide is supplied from bottles that are attached to the bar's dispensing system.

Kegs that have been emptied of liquid (and are hence full of pressurised gas) are returned to the brewery from the bar, where they are vented to atmosphere before being re-filled with beverage. This venting constitutes a significant source of carbon dioxide emissions, and as CO is a "greenhouse" gas it is therefore desirable to reduce the amount of these emissions to a minimum. In addition, in order to fill the kegs with carbon dioxide, the bar must regularly purchase or lease bottles of CO₂, which are expensive. There is also an environmental impact from the supply of the bottles to different bars, as there are exhaust emissions from the delivery trucks.

It is an object of the present invention to obviate or mitigate these disadvantages with prior art systems, and to provide a gas reclamation system to lessen the need for supplying large quantities of carbon dioxide to run beverage dispensing systems in bars.

According to a first aspect of the present invention there is provided a gas reclamation system for use in a beverage dispensing system comprising a coupler for releasable connection to a used beverage container containing a pressurised gas, the coupler allowing release of gas from the container, and a compressor connected to the coupler and arranged to pressurise released gas for supply to the beverage dispensing system.

Preferably, a gas sensor, a pressure sensor, a filter, a steriliser and a collection tank are provided upstream of the compressor. Optionally the steriliser comprises an ioniser and a de-ioniser. Optionally a collecting tank, and more preferably a plurality of collecting tanks are provided downstream of the compressor. The steriliser may comprise an ioniser and a de-ioniser. A separator may also be provided to separate different gases, one of which is passed to the compressor. This may be used if the gas in the container is a mixture of gases such as nitrogen and carbon dioxide. Alternatively the separator may be used to direct the different gases/gas mixtures to different collection tanks.

One or more of the above components may be under the control of a central processing unit, hi this way direction of the gas being reclaimed may be automatically regulated (e.g. to the correct correction vessel).

The gas to be reclaimed will generally be carbon dioxide.

The gas reclamation system according to the present invention reduces the amount of carbon dioxide that is used in beverage dispensing systems, and thus reduces harmful CO emissions to the atmosphere. The reduction in consumption of CO also means that the cost of running a beverage dispensing system is substantially reduced.

According to a second aspect of the present invention there is provided a beverage dispensing system comprising a gas reclamation system in accordance with the first aspect of the invention, a dispensing coupler for connection to a container from which a beverage is to be dispensed, and a gas supply line connected to the dispensing coupler to supply pressurised gas to the gas supply line.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a schematic illustration of a prior art beverage dispensing system;

Figure 2 is a schematic illustration of a gas reclamation system according to the present invention;

Figure 3 is a schematic illustration of a beverage dispensing system incorporating the gas reclamation system of Figure 2; and Figure 4 is a schematic illustration of a second embodiment of a gas reclamation system according to the present invention.

Referring to Figure 1 of the accompanying drawings, there is illustrated a prior beverage dispensing system comprising a plurality of kegs 1, each connected to a keg coupler 2 provided with two valves 3, 4. One of the valves 3 of each keg coupler 2 is attached to a line 5. Each line 5 is attached at its other end to a dispense head gas pump 6 which is powered using compressed air, which is typically provided on a bar to dispense draught beverages, and may be provided some distance from the remainder of the beverage dispensing system, including the kegs, which may typically be placed in a cellar of the bar.

The valves 4 of the keg couplers 2 are each connected to a line 7 that is attached at its other end to a valve 8 provided on a gas ring main 9. A carbon dioxide supply bottle 10 is also attached to the gas ring main 9.

A compressor 11 is attached to an air ring main 12, and supplies pressurised air to the air ring main 12 by valves 13 and 14 in order to drive the dispense heads 6. The gas bottle 10 is also connected to the valve 13 via line 15, the valve 13 being arranged to supply carbon dioxide to the dispense heads from the gas bottle 10 in the event that the air compressor fails.

As beer or another beverage is dispensed from dispense heads 6, carbon dioxide from supply bottle 10 is used to maintain a roughly constant top pressure in the kegs 1. As a result, once all the beverage within a keg has been dispensed, the keg is full of pressurised carbon dioxide. The bottle 10 must be changed frequently as the carbon dioxide is used up.

Referring now to Figure 2, a gas reclamation system according to the present invention is illustrated which can be used to recover carbon dioxide from a keg taken from a system such as that shown in Figure 1. It comprises an input line attached to a keg coupler 2 for connection to a gas-filled keg 1, the line feeding to, in sequence, a filter 16, a steriliser 17, a separator 18, a collection tank 19, a food quality compressor 20 and finally to an outlet line 21. The outlet line 21 could be connected to, for example, a gas storage bottle such as the bottle 10 of Figure 1, but is preferably connected to the gas ring main of the beverage dispense system, as shown in Figure 3. The same reference numerals are used where appropriate in Figures 1, 2 and 3. The compressor 20 is provided in a compressor station 22, the compressor outlet line 21 being connected to the gas ring main 9. The gas bottle 10 is connected to the gas ring main 9 through the valve 13 such that gas is supplied from the bottle 10 only when the compressor is unable to maintain the required top pressure within the kegs 1 connected to the gas ring main 9.

In the embodiment shown in Figure 3, the pressure required to work the dispense heads 6 is drawn from a separate air ring main (not shown) with its own compressor. A one-way valve (not shown) could be provided from the gas ring main 9 to the air ring main in order to supply carbon dioxide from the gas ring main in the event that there is not enough pressure in the air ring main to power the dispense heads.

The use of the system is as follows:

Full kegs 1 are connected to the keg couplers 2 that are attached to the dispensing lines 5 and the beverage is dispensed from the heads 6. As the pressure in a keg 1 falls due to the beverage being dispensed, the valves 4 open to introduce carbon dioxide into the keg 1 from the gas ring main 9 in order to keep the pressure within the keg within predetermined levels.

Once all the beer or other beverage has been dispensed from the keg, and the keg is full of carbon dioxide, the keg 1 is disconnected from the dispensing system by removal of keg coupler 2. A valve (not shown) on the keg prevents any egress of the contents during movement thereof. The keg is then moved to the reclamation system, and attached to the keg coupler 2 that is connected to the inlet line that is coupled to the filter 16, which releases the pressurised gas from the keg into the reclamation system. The gas is first passed through filter 16. The filtration process removes any fluid contents from the gas, together with particulate matter. The gas is then passed into steriliser 17 to remove any bacteria therefrom. After sterilisation, separator 18 separates any nitrogen from the carbon dioxide and thereby assists in the recovery of the CO₂. The nitrogen may be vented to atmosphere, or may be collected separately from the CO₂. If the system does not include nitrogen gas, the separator 18 may be omitted. The resultant CO is then collected in collection tank 19 before being re- pressurised by the compressor 20 in order to be supplied to the gas ring main 9. A collection rate of approximately 80% of reusable gas is obtainable by this process. A higher collection rate is not thought to be optimal because a large amount of particulate matter and bacteria remain in the final 20% of the gas left in the keg, which would require more sophisticated cleaning and filtration steps, and hence would be more expensive to operate. In addition, the remaining contents of the keg may have to be removed under a reduced pressure rather than at atmospheric pressure. However, collection of the final portion of CO₂ may be desirable in some circumstances.

It should be appreciated that, although a CO₂ bottle 10 is provided in this system as a back-up to the reclamation system, the amount of additional CO₂ that needs to be added to the drinks dispensing system is greatly reduced in comparison with prior art systems. The bottle 10 should therefore only need to be replaced infrequently.

Referring to Figure 4 a second embodiment of a gas reclamation system according to the present invention is illustrated which can be used to recover carbon dioxide and other gases and gas mixtures such as nitrogen and nitrogen/CO₂ from a keg system such as that shown in Figure 1.

The system comprises an input line attached to a keg coupler 2 for connection to a gas filled keg 1. The line feeds, in sequence, to; a moisture remover 23, an anti- vacuum valve 24, a gas sensor 25, a pressure sensor 26, a steriliser 17 (comprising an ioniser 27 and a de-ioniser 28), a compressor 20, a plurality of collection tanks 19 (for carbon dioxide, an admixture of carbon dioxide/air and nitrogen for example) and finally an outlet line 21. The compressor is linked to the collection tanks by collection lines 29. The outlet line 21 can be connected to, for example, a gas storage bottle such as the bottle 10 of Figure 1, but is preferably connected to the gas ring main of the beverage dispenser system, as shown in Figure 3.

The use of the system is as follows:

Once all the beer has been dispensed from the keg 1 and the keg 1 is full of carbon dioxide/other gases, keg 1 is disconnected from the dispensing system and connected to the reclamation system via keg coupler 2 on the inlet line. Each of the following stages described below is overseen by a central processing unit 30, which is connected to each operable component of the reclamation system.

Once connected the pressure of gas within the keg 1 is checked by pressure sensor 26. The composition of the gas is also analysed using gas sensor 25. For preference the gas sensor operates using infra-red spectroscopy as an analytical tool to analyse the connect of the keg gas. This information is fed to the processing unit 30, which evaluates the pressure of the relevant collection tank 19 (via a pressure sensor "PS") to ascertain whether gas collection can begin.

If the collection tank 19 is capable of accepting the incoming gas, a small amount of gas is vented from the tank 19 via collection tank valve 31 (under the control of the processing unit 30) in order to reduce cross contamination in the system. Collection tank valve 31 is most preferably an electronic solenoid valve "GN. In this way the system from the collection tank 19 to a valve 32 at the pressure sensor 26 is filled with gas which is substantially the same as that being collected. Pressure sensor valve 32 is then opened (under the control of the processing unit 30) allowing gas from keg 1 to enter the system. The gas passes through the moisture remover 23, where the moisture is removed from the gas, past the pressure sensor valve 32 and through the ioniser 27 (activated by the processing unit 30) where it is exposed to a high voltage negative ion stream to substantially destroy any contaminants in the gas stream. The gas is subsequently de-ionised and filtered in the de-ioniser 28 (activated by the processing unit 30). The gas is then compressed by compressor 20 and passed to collection tank 19 via line 29 passed collection tank valve 31.

Once gas reclamation is complete, keg 1 is de-coupled and under the control of the processing unit 30 tank valve 31 is closed, and the system operates a purge cycle. With keg coupler 2 closed the compressor 20 is operated. In this way gas is purged via a purge valve 33 in the outlet line 21, which is fluidly connected to collecting lines 29 upstream of tank valves 31, until a partial vacuum forms in the system.

The gas reclamation system of the second embodiment is also capable of carrying out a self diagnostic check. On power-up for the first time the processing unit 30 performs a series of pressure checks. This is carried out by opening pressure sensor valve 32 and operating compressor 20 with all of collection valves 29 open. The collection tanks 19 are thus pressurised to a pre-set pressure and collection valves 29 are closed. Gas pressure at each collection valve 29 is then monitored by the processing unit 30 to make sure that the tank pressures remain at the level they were charged to. If the collection tanks 19 are shown to be gas tight, the collection tanks

19 will be vented to atmosphere via outlet 21, by opening tank valves 31 and purge valve 33.

The system is then operated to carry out a pre-purge to prevent gas contamination between collection tanks 19. This is carried out by operating the compressor 20 when all collection tank valves 31 and the purge valve 33 are open. Additionally a CO₂ purge line, (illustrated as being fluidly connecting the compressor

20 and the line 29 leading to the CO collection tank, although connection to any other collection tank is possible), having a purge valve 35, is open. The compressor 20 is operated in this condition until a substantial vacuum is generated in the system upstream of the pressure sensor valve 32. The tank valves 31 and each of the purge valves (31, 35) are then closed.

Anti-vacuum valve 24 is present in the reclamation system to prevent a vacuum lock up on the compressor 20, to prevent the compressor 20 stalling on start up of a gas recovery stage after a gas purge.

Claims

1. A gas reclamation system for use in a beverage dispensing system comprising a coupler for releasable connection to a used beverage container containing a pressurised gas, the coupler allowing release of gas from the container, and a compressor connected to the coupler and arranged to pressurise released gas for supply to the beverage dispensing system.

2. A gas reclamation system according to claim 1 wherein a gas sensor is provided upstream of the compressor to identify the gas being reclaimed.

3. A gas reclamation system according to claim 1 or 2, wherein a pressure sensor is provided upstream of the compressor.

4. A gas reclamation system according to claim 1,2 or 3 wherein a collection tanks is provided upstream of the compressor.

5. A gas reclamation system according to any one of claims 1 to 4, wherein a separator is provided to separate different gases, one of which gases is passed to the compressor.

6. A gas reclamation system according to claim 1 2 or 3, wherein a plurality of collection tanks are provided downstream of the compressor.

7. A gas reclamation system according to claim 6 wherein a separator directs the gas to the correct collection tank.

8. A gas reclamation system according to claim 7 wherein the separator is activated by a central processing unit which liases with the gas sensor.

9. A gas reclamation system according to any one of the preceding claims, wherein the system operates to provide a purge after each gas reclamation procedure.

10. A gas reclamation system according to any preceding claim, wherein the gas to be reclaimed is carbon dioxide.

11. A gas reclamation system according to any preceding claim, wherein a filter is provided upstream of the compressor.

12. A gas reclamation system according to any preceding claim, wherein a steriliser is provided upstream of the compressor.

13. A gas reclamation system according to claim 12, wherein the steriliser comprises an ioniser and a de-ioniser.

14. A beverage dispensing system comprising a gas reclamation system according to any preceding claim, a dispensing coupler for connection to a container from which a beverage is to be dispensed, and a gas supply line connected to the dispensing coupler to supply pressurised gas to the gas supply line.

15. A gas reclamation system substantially as hereinbefore described, with reference to the accompanying drawings.

16. A beverage dispensing system substantially as hereinbefore described, with reference to the accompanying drawings.