GB1559687A

GB1559687A - Storage and dispensing of beverages

Info

Publication number: GB1559687A
Application number: GB617176A
Authority: GB
Original assignee: BOC Ltd
Current assignee: BOC Ltd
Priority date: 1976-02-17
Filing date: 1976-02-17
Publication date: 1980-01-23
Also published as: IE45115L; IE45115B1; AU2233277A; AU507441B2; DE2705150A1

Description

(54) STORAGE AND DISPENSING OF BEVERAGES (71) We, BOC LIMITED of Hammersmith House, London, W6 9DX, England, an English company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the storage and dispensing of beverages, particularly, but not exclusively, fermented beverages, under gas pressure.

It is known to keep beverages, usually beer, in a cask under a gas pressure which is sufficient to effect dispensing of the beer when a valve in an outlet line from the cask is opened. The gas is usually carbon dioxide which is dissolved in the beer and is also present under pressure in the head space above the beer to effect dispensing of the beer when the aforesaid valve is opened. It is also known to use instead of carbon dioxide alone a gaseous mixture of carbon dioxide and an inert gas, principally nitrogen, to give a relatively fast dispensing time without producing an unacceptable amount of frothing.

The gaseous mixture is supplied to the beer in the cask from a cylinder in which the mixture is contained under pressure. The gas cylinder may be incorporated within the cask, or a plurality of gas cylinders or a single larger cylinder containing the gaseous mixture may supply a number of casks. A disadvantage of this system is that equipment is required, at a site having a bulk supply of the gases for recharging the cylinders, to mix the gases and to compress the gaseous mixture so formed so that it is stored in the cylinders at a relatively high pressure, e.g. above 700 p.s.i.g., in order to prevent the carbon dioxide from liquefying and separating from the nitrogen.

The invention provides a method for storing and dispensing a beverage under gas pressure, which method comprises providing, at a location where the beverage is to be stored and dispensed, a supply of pressurized inert gas and a supply of pressurized carbon dioxide, mixing such gases to form a pressurized gaseous mixture thereof having a predetermined proportion of the gases in the mixture, and feeding such pressurized mixture directly into at least one container containing a beverage so as to maintain the beverage in a pressurized condition.

The invention also provides apparatus for storing and dispensing a beverage under gas pressure, which apparatus comprises one or more containers of beverage, a supply of pressurized inert gas, a supply of pressurized carbon dioxide, means to mix such gases to form a pressurized gaseous mixture having a predetermined proportion of the gases in the gases in the mixture, and means supplying the pressurized gaseous mixture directly to said one or more containers to maintain the beverage provided therein in a pressurized condition.

The term 'inert gas' is used herein to mean a gas which does not react chemically with the beverage, does not promote chemical reactions in the beverage, and is virtually tasteless and non-toxic. Specifically the term 'inert' gas' as used herein excludes any gas or gas mixture having a substantial proportion of oxygen (such as air).

The preferred inert gas is nitrogen.

According to a feature of the invention, the gases may be mixed in a gas mixing chamber having a first inlet for receiving inert gas, a second inlet for receiving carbon dioxide, and an outlet for a gaseous mixture of inert gas and said another gas, for connection directly to said beverage container(s). The inert gas may be stored in either gaseous form, or in liquid form from which gaseous inert gas is evaporated e.g. by heat exchange with the ambient atmosphere, prior to mixing with gaseous carbon dioxide, which itself is preferably stored as a liquid.

An advantage of a method and apparatus according to the invention is that the gaseous mixture, which is formed by mixing at a relatively low pressure, e.g. 50 p.s.i.g, is fed directly to the beverage containers without the need to compress it to a relatively high pressure for forage and transport in cylinders A method and apparatus according to the invention provides a simpler, more reliable and less expensive system as compared to the above described prior art systems.

Preferably pressure regulators will be provided in the inert gas and carbon dioxide lines, respectively, upstream of the mixing chamber to deliver such gases at predetermined pressures to give the required partial pressures in the gaseous mixture. The mixing chamber may comprise a T-section pipe joint having two inlet jets for metering the flow cf the inert gas and the carbon dioxide, respectively into the chamber.

One-way valves are preferably provided in the inert gas and carbon dioxide lines upstream of the mixing- chamber.

One embodiment of the invention will now be described by way of example and with reference to the accompanying drawing which is a diagrammatic representation of an apparatus according to the invention.

Referring to the drawing, there is shown an apparatus for storing and dispensing beer or lager for location for example at a public house or other licensed premises. The apparatus includes a vacuum insulated vessel 10 having a valved inlet line 11 through which the vessel is filled with liquid nitrogen. The capacity of the vessel 10 is likely to be 150 or 165 litres. The vessel further has a gas outlet line 12 having an evaporator 13 exposed to the ambient atmosphere, a control valve 14, a pressure regulator 15 to reduce the delivery pressure of the nitrogen to a predetermined value, and a one-way valve 16, the line 12 being connected at its end remote from the vessel 10 to one inlet of a T-section mixing chamber 17.

The vessel 10 is also provided with a second outlet line 18 leading from the bottom of the container. The line 18 is connected to line 12 upstream of the evaporator 13 and is controlled by a pressure responsive valve 19.

The line 18 has a portion extending within the vacuum space of vessel 10 which is attached to its outer wall so that heat exchange with the ambient atmosphere takes place by conduction through that outer wall to effect vaporisation of liquid nitrogen which passes into the line under gravity. The valve 19 senses the pressure in the line 12 and is set to close when this pressure rises above a chosen value, thereby allowing repressurisation of the gas in the line 12, whilst preventing overpressurisation in the vessel which would lead to lifting of the pressure relief valve 21 referred to below and excessive gas usage.

The vessel 10 is further provided with a line 20 containing a pressure relief valve 21 and a rupturable disc 22, a valved vent line 23 and a liquid level gauge 24. The valves in the inlet line 11 and the vent line 23 are keyoperated to prevent unauthorised or accidental operation thereof.

The nitrogen gas from 12 passes into chamber 17 through an inlet jet. Carbon dioxide is supplied from a cylinder 25 through a line 26 containing a pressure regulator 27 and a one-way valve 28, to the mixing chamber. One-way valves 16 and 28 are provided to allow the feed of only nitrogen or only carbon dioxide through the mixing chamber which is permissible for short periods without detrimental effect to the beer, for example at changeover of carbon dioxide cylinders.

The carbon dioxide enters the chamber 17 through a jet and at a pressure equal to that of the nitrogen This pressure is preferably in the range 25 to 60 psig, for example in the range 25 to 40 psig.

The cross-sectional areas of the inlet jets for nitrogen and carbon dioxide, respectively, are dimensioned to control the volume flow therethrough so as to give the required ratio of the gases in the mixture at the required flow rate and pressure, e.g. 35 to 40 psig, taking into account a pressure drop of the order of 10 psig between the mixing chamber and beer container. The ratio of the gas in the mixture is preferably in the. range 70:3o0 t 50:50 (nitrogen: carbon dioxide), for example in the range 70:30 to 60:40.

The gseous mixture of nitrogen and carbon dioxide leaves the chamber through a delivery line 29 controlled by an on-off valve 30. The delivery line 29 leads to a ring main. The gas delivered into the main, when at a relatively low pressure, may supply a number of beer casks, or an individual cask, and, when at a relatively high pressure, may supply kegs or bulk tanks. Indeed, an apparatus according to the invention may be used to supply a transportable tank or may itself be mountedon a bulk delivery road tanker.

Closing valve 30 allows the system to be disconnected from the ring main for replacement by another unit or any other purpose.

Alternatively each keg may be provided with an on/off valve and a pressure regulator.

In other embodiments for smaller scale uses the liquid store of nitrogen may be replaced by a cylinder of compressed nitrogen gas which replaces the liquid cylinder and vaporiser.

WHAT WE CLAIM IS 1. A method for storing and dispensing a beverage under gas pressure, which method comprises providing at a location where the beverage is to be stored and dispensed a supply of pressurised inert gas (as herein defined) and a supply of pressurized carbon dioxide, mixing such gases to form a pressurized gaseous mixture thereof having a predetermined proportion of the gases in the mixture, and feeding such pressurized gaseous mixture directly into at least one container containing a beverage so as to maintain the beverage in a pressurized condition.

2. A method as claimed in Claim 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. and less expensive system as compared to the above described prior art systems. Preferably pressure regulators will be provided in the inert gas and carbon dioxide lines, respectively, upstream of the mixing chamber to deliver such gases at predetermined pressures to give the required partial pressures in the gaseous mixture. The mixing chamber may comprise a T-section pipe joint having two inlet jets for metering the flow cf the inert gas and the carbon dioxide, respectively into the chamber. One-way valves are preferably provided in the inert gas and carbon dioxide lines upstream of the mixing- chamber. One embodiment of the invention will now be described by way of example and with reference to the accompanying drawing which is a diagrammatic representation of an apparatus according to the invention. Referring to the drawing, there is shown an apparatus for storing and dispensing beer or lager for location for example at a public house or other licensed premises. The apparatus includes a vacuum insulated vessel 10 having a valved inlet line 11 through which the vessel is filled with liquid nitrogen. The capacity of the vessel 10 is likely to be 150 or 165 litres. The vessel further has a gas outlet line 12 having an evaporator 13 exposed to the ambient atmosphere, a control valve 14, a pressure regulator 15 to reduce the delivery pressure of the nitrogen to a predetermined value, and a one-way valve 16, the line 12 being connected at its end remote from the vessel 10 to one inlet of a T-section mixing chamber 17. The vessel 10 is also provided with a second outlet line 18 leading from the bottom of the container. The line 18 is connected to line 12 upstream of the evaporator 13 and is controlled by a pressure responsive valve 19. The line 18 has a portion extending within the vacuum space of vessel 10 which is attached to its outer wall so that heat exchange with the ambient atmosphere takes place by conduction through that outer wall to effect vaporisation of liquid nitrogen which passes into the line under gravity. The valve 19 senses the pressure in the line 12 and is set to close when this pressure rises above a chosen value, thereby allowing repressurisation of the gas in the line 12, whilst preventing overpressurisation in the vessel which would lead to lifting of the pressure relief valve 21 referred to below and excessive gas usage. The vessel 10 is further provided with a line 20 containing a pressure relief valve 21 and a rupturable disc 22, a valved vent line 23 and a liquid level gauge 24. The valves in the inlet line 11 and the vent line 23 are keyoperated to prevent unauthorised or accidental operation thereof. The nitrogen gas from 12 passes into chamber 17 through an inlet jet. Carbon dioxide is supplied from a cylinder 25 through a line 26 containing a pressure regulator 27 and a one-way valve 28, to the mixing chamber. One-way valves 16 and 28 are provided to allow the feed of only nitrogen or only carbon dioxide through the mixing chamber which is permissible for short periods without detrimental effect to the beer, for example at changeover of carbon dioxide cylinders. The carbon dioxide enters the chamber 17 through a jet and at a pressure equal to that of the nitrogen This pressure is preferably in the range 25 to 60 psig, for example in the range 25 to 40 psig. The cross-sectional areas of the inlet jets for nitrogen and carbon dioxide, respectively, are dimensioned to control the volume flow therethrough so as to give the required ratio of the gases in the mixture at the required flow rate and pressure, e.g. 35 to 40 psig, taking into account a pressure drop of the order of 10 psig between the mixing chamber and beer container. The ratio of the gas in the mixture is preferably in the. range 70:3o0 t 50:50 (nitrogen: carbon dioxide), for example in the range 70:30 to 60:40. The gseous mixture of nitrogen and carbon dioxide leaves the chamber through a delivery line 29 controlled by an on-off valve 30. The delivery line 29 leads to a ring main. The gas delivered into the main, when at a relatively low pressure, may supply a number of beer casks, or an individual cask, and, when at a relatively high pressure, may supply kegs or bulk tanks. Indeed, an apparatus according to the invention may be used to supply a transportable tank or may itself be mountedon a bulk delivery road tanker. Closing valve 30 allows the system to be disconnected from the ring main for replacement by another unit or any other purpose. Alternatively each keg may be provided with an on/off valve and a pressure regulator. In other embodiments for smaller scale uses the liquid store of nitrogen may be replaced by a cylinder of compressed nitrogen gas which replaces the liquid cylinder and vaporiser. WHAT WE CLAIM IS

1. A method for storing and dispensing a beverage under gas pressure, which method comprises providing at a location where the beverage is to be stored and dispensed a supply of pressurised inert gas (as herein defined) and a supply of pressurized carbon dioxide, mixing such gases to form a pressurized gaseous mixture thereof having a predetermined proportion of the gases in the mixture, and feeding such pressurized gaseous mixture directly into at least one container containing a beverage so as to maintain the beverage in a pressurized condition.

2. A method as claimed in Claim 1

wherin the inert gas is stored at said location as a liquid which is vaporised prior to mixing with gaseous carbon dioxide.

3. A method as claimed in Claim 1 wherein the inert gas is stored at said location in the gaseous state and under pressure.

4. A method as claimed in any of the preceding claims wherein the carbon dioxide is stored at said location in the liquid state.

5. A method as claimed in any of Claims 1 to 4 wherein the inert gas is nitrogen.

6. A method as claimed in any of claims 1 to 5 wherein the ratio of the gases (by volume) in the mixture is in the range 70:30 to 50:50 (inert gas:carbon dioxide).

7. A method as claimed in Claim 6 wherein said ratio is in the range 70:30 to 60:40.

8. A method as claimed in any of the preceding claims wherein the pressure of the inert gas/carbon dioxide mixture is in the range 35 to 40 p.s.i.g.

9. A method as claimed in any of the preceding claims wherein the pressure of the inert gas is substantially equal to that of the carbon dioxide before mixing thereof.

10. A method as claimed in Claim 9 wherein said pressure is in the range 25 to 60 p.s.i.g.

11. A method as claimed in Claim 9 or Claim 10 wherein said pressure is in the range 25 to 40 p.s.i.g.

12. A method for storing and dispensing a beverage under gas pressure, substantially as hereinbefore described with reference to the accompanying drawing.

13. Apparatus for storing and dispensing a beverage under gas pressure, which apparatus comprises one or more containers of the beverage, a supply of pressurised inert gas, (as herein defined) a supply of pressurized carbon dioxide, means to mix such gases to form a pressurised gaseous mixture thereof having a predetermined proportion of the gases in the mixture, and means supplying the pressurised gaseous mixture directly to said one or more containers to maintain the beverage provided therein in a pressurized condition.

14. Apparatus as claimed in Claim 13 wherein said supply of pressurized inert gas includes a vacuum-insulated vessel containing liquid inert gas, the vessel having a gas outlet line containing an evaporator for heat exchange with the ambient atmosphere and a liquid line from a lower portion of the vessel, which liquid line communicates with the gas outlet line and has a vaporizing portion for evaporating liquid gas therein and a regulator responsive to the pressure in the gas outlet line to permit repressurisation thereof when such pressure drops below a predetermined value.

15. Apparatus as claimed in Claim 13 or Claim 14 wherein there is provided a gas mixing chamber having a first inlet connected to receive inert gas from said supply thereof, a second inlet connected to receive carbon dioxide from said supply thereof, and an outlet for a gaseous mixture of inert gas and carbon dioxide, which outlet communicates with said means supplying the pressurized gaseous mixture.

16. Apparatus as claimed in Claim 15 wherein pressure regulators are provided in lines for supplying inert gas and carbon dioxide to the mixing chamber whereby such gases can be delivered to the chamber at predetermined pressures.

17. Apparatus as claimed in Claim 15 or Claim 16 wherein the mixing chamber comprises a tubular T-piece having in respective limbs of such piece two inlet jets for metering the flow of the inert gas and carbon dioxide, respectively, into the chamber, and an outlet for the gaseous mixture thereof.

18. Apparatus as claimed in any of Claims 15 to 17 wherein one-way valves are provided in lines for supplying the inert gas and carbon dioxide to the mixing chamber.

19. Apparatus as claimed in any of the Claims 13 to 18 wherein said means supplying the gaseous mixture directly to one or more containers for beverage includes a gas ring main adapted to supply a plurality of such containers.

20. Apparatus for storing and dispensing a beverage under pressure according to claim 13 and substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawing.