US3613954A

US3613954A - Dispensing apparatus

Info

Publication number: US3613954A
Application number: US747061*A
Authority: US
Inventors: Peter D Bayne
Original assignee: Jos Schlitz Brewing Co
Current assignee: STROH BREWERY COMPANY; JPMorgan Chase Bank NA; Jos Schlitz Brewing Co
Priority date: 1968-06-20
Filing date: 1968-06-20
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19

Abstract

The invention relates to a dispensing unit for dispensing a beverage containing dissolved carbon dioxide and which utilizes a liquified fluorocarbon gas as a pressurizing medium. The unit includes a closed container containing a beverage having dissolved carbon dioxide. The liquified fluorocarbon gas is contained in a separate reservoir which communicates directly with the headspace of the container above the liquid level. As the beverage is drawn from the container, the volume of the headspace increases, thereby decreasing the pressure in the headspace and resulting in the vaporization of additional quantities of the liquified fluorocarbon gas which act to maintain the desired counterbalancing pressure within the headspace to keep the carbon dioxide in solution in the beverage.

Description

United States Patent Clark et a1.

[72] Inventor Peter D. Bayue 2,950,846 8/1960 222/399 Shorewood wi 2,962,196 11/1960 Ayres 222/399 [21] Appl. No. 747,061 3,072,487 1/1963 Webster 222/399 X [22] il d June 20 19 3,291,343 12/1966 Tracey et al.. 222/399 X 5 p d Oct 19 1971 3,161,324 12/1961 ONe11l 222/399 X [73] Assignee Schulz Brewing Company 2,794,579 6/1957 McKernan. 222/399 Milwaukee,wis 3,063,841 11/1962 Ash 222/399 X C ti ti i n f application s 3,127,059 3/ 1964 Lawrence, Jr. et a1 222/ 399 X 574,971, Aug. 25, 1966, now abandoned. p Examine, Evon C. Blunk Assistant Examinerl-1add S. Lane Attorney-Andrus, Sceales, Starke & Sawall [54] DISPENSING APPARATUS 16 Claims, 8 Drawing Figs.

ABSTRACT: The invention relates to a dispensing unit for [52] US. Cl ZZZ/61, dispensing a beverage containing dissolved carbon dioxide 222/399 222/400'7 and which utilizes a liquified fluorocarbon gas as a pressuriz- [51] Int. Cl 1B67d 5/08, ing medium The unit includes a closed Container containing a B65d 83/14 beverage having dissolved carbon dioxide. The liquified [50] Field of Search 222/52, fluorocarbon gas is contained i a separate reservoir i h 192 communicates directly with the headspace of the container above the liquid level. As the beverage is drawn from the con- [56] References Cited tainer, the volume of the headspace increases, thereby UNHED STATES PATENTS decreasing the pressure in the headspace and resulting in the 1,072,239 9/ 1913 Kleinfeldt 222/399 X vaporization of additional quantities of the liquified fluorocar- 2,569,378 9/1951 Hood 222/399 X bon gas which act to maintain the desired counterbalancing 2,643,800 6/1953 Todd et a1... ZZZ/400.7 pressure within the headspace to keep the carbon dioxide in 2,732,977 1] 1956 Charpiat 222/399 X solution in the beverage.

PATENTEDnm 19 I9?! SHEET 10F 3 INVENTOR PETE-R D- BAYNE DISPENSING APPARATUS This application is a continuation-impart of application Ser. No. 574,97l,filed Aug. 25, 1966 and entitled Dispensing Apparatus now abandoned.

This invention relates to a dispensing apparatus and more particularly to an apparatus for containing and dispensing a gas-containing beverage.

Malt beverages, such as beer and ale, as well as many soft drinks, and'wines, contain dissolved carbon dioxide. To keep the carbon dioxide in solution in the beverage, it is necessary to maintain a counter pressure in the headspace of the container in excess of about 16 p.s.i.g. at 45 F. for beverages containing about about 0.5 percent by weight of carbon dioxide. With a sealed container, such as a bottle or can, having limited headspace above the liquid level, an equilibrium is reached in which the pressure of the carbon dioxide gas in the headspace will balance the pressure of the dissolved carbon dioxide so that no further carbon dioxide will go out of solution. However, in the case of a draft package, such as a keg or small disposable unit, where the beverage is periodically dispensed, the headspace is progressively increased and it is necessary to introduce additional gas into the headspace to balance the pressure and prevent the carbon dioxide in the beverage from coming out of solution. With keg beer, an auxiliary tank of carbon dioxide is normally employed and pressure regulating equipment maintains the counterbalancing pressure of the carbon dioxide in the headspace at a constant level at all times. While this type of pressure regulating system is satisfactory for large kegs, it is expensive and cannot be used from an economical standpoint with small, disposable dispensing units.

In some cases, air pumps have been used with small dispensing units in order to supply air to the headspace to provide a dispensing pressure as well as to keep the carbon dioxide in solution. However, with the air pump system, it is difficult to maintain a constant pressure and the unit cannot be left unattended for long periods without the pressure decreasing and the carbon dioxide passing out of solution, thereby resulting in a stale product. Moreover, the contact of beer with air will create conditions for rapid microbiological spoilage if the contents are not immediately consumed.

Liquified fluorocarbon gases, such as those sold under the trade name of Freon, have been used a propellants for many food products. The liquified fluorocarbon gas exists in the container as a liquid whose vapor pressure exceeds atmospheric pressure at a temperature at which the product is to be discharged. Since the pressure in the container is substantially equal to the vapor pressure of the liquified gas and is independent of the volume an of the free space in the container, the pressure in the container will be virtually constant throughout the discharge life of the system as long as liquified gas is present in the container. Because of these advantages, liquified fluorocarbon gas propellants, such as Freons, have been used a propellants for a wide variety of food products. However, liquified fluorocarbon gases have not been successfully used as propellants for carbon dioxide containing beverages, for when the liquified gas is in direct contact with the beverage, is has been found that a loss of the dissolved carbon dioxide results. Thus, all successful attempts to use a liquified fluorocarbon gas as a propellant for carbon dioxide containing beverages, have employed flexible embraces which separate the liquified gas and the beverage and prevent direct physical contact between the components.

The loss of the dissolved carbon dioxide when using a liquified fluorocarbon gas is believed to be brought about, at least in part, by the fluorocarbon gas stripping the carbon dioxide from the beverage as the vaporized gas bubbles upwardly through the beverage. The liquified gas, being heavier than the beverage, forms a puddle at the bottom of the container. When the beverage is dispensed and the volume of the headspace is increased, a portion of the liquified gas will vaporize to restore the pressure in the headspace and the dense vapor will rise upwardly through the beverage. This results in a stripping action which tends to strip the dissolved carbon dioxide from the beverage. A second reason for the loss of carbon dioxide when using a liquid fluorocarbon gas in direction contact with the beverage is that the recovery of the balancing pressure in the headspace is relatively slow, so that the carbon dioxide will tend to come out of solution during the recovery period. When the liquified gas vaporizes, the heat required for vaporization must be extracted from the beverage, and as the beverage is normally cold, the rate of vaporization of the liquified gas is relatively slow. Moreover, the vaporization of the liquified gas at the bottom of the container will further chill the beverage at the bottom of the container, thereby tending to stratify, rather than circulate, the beverage and retard furtherheat transfer from the beverage to the liquified gas. This results in a relatively slow recovery of the vapor pressure in the headspace of the container when the beverage is drawn, and a portion of the dissolved carbon dioxide will pass out of solution into the headspace during this period of slow recovery.

The present invention is directed to a unit for dispensing a beverage containing dissolved carbon dioxide and which utilizes a liquified fluorocarbon gas as a pressurizing medium. In the unit of the invention, the fluorocarbon gas or vapor is in direct contact with the beverage and yet there is no appreciable loss of dissolved carbon dioxide from the beverage during dispensing of the beverage from the container. More specifically, the unit includes a closed container, such as a keg, can or carton, containing a beverage having dissolved carbon dioxide. The liquified fluorocarbon gas is contained in a separate container or reservoir which communicates directly with the headspace of the container above the liquid level. As the beverage is drawn from the container, the volume of the headspace increases thereby decreasing the pressure in the headspace and resulting in the vaporization of additional quantities of the liquified fluorocarbon gas to maintain the desired counterbalancing pressure within the headspace to keep the carbon dioxide in solution in the beverage.

The liquified fluorocarbon gas should have a vapor pressure sufficient to maintain the carbon dioxide in solution in the beverage being dispensed. To maintain the carbon dioxide in solution in a malt beverage such as beer, the liquified fluorocarbon gas has a composition such that its vapor pressure at 45 F. will be above 15 p.s.i.g. and preferably in the range of 17 to 20 p.s.i.g. It has been found that a mixture of about 10 to 15 percent by weight of chloropentafluoroethane and to percent by weight of octafluorocyclobutane provides a liquified gas composition having the desired vapor pressure at this temperature.

The fluorocarbon gas in the headspace of the container achieves an unusual and unobvious effect in retarding or substantially preventing the dissolution of the carbon dioxide from the beverage. This enables the beverage to be retained for long periods without losing its carbonation and going stale.

In the preferred embodiment, the reservoir or container for the liquified fluorocarbon gas is located outside of the container for the beverage, so that the heat required for vaporization of the liquified gas can be extracted from the surroundings and this provides a faster recovery for the gaseous phase in the headspace.

By using a liquified fluorocarbon gas as the counter balancing pressure, the dispensing unit is self-regulating in that the pressure within the headspace will remain constant for any given temperature regardless of the quantity of beverage which is present in the container. Moreover, the unit provides an automatic adjustment for temperature which serves to prevent the dissolved carbon dioxide from coming out of solution during changers in temperatures of the beverage.

As the counterbalancing pressure is achieved without auxiliary pressure regulating equipment, the dispensing unit can be economically mass produced and is particularly adaptable for a small, disposable dispensing unit, to be located in a household refrigerator.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best modes presently contem plated of carrying out the invention.

In the drawings:

FIG. 1 is a diagrammatic view of a dispensing unit for a beverage and incorporating a cartridge containing a liquified fluorocarbon gas;

FIG. 2 is a view similar to FIG. 1 showing a modified form of the invention in which the liquified fluorocarbon gas is contained within a float;

FIG. 3 is a view similar to FIG. 1 showing a second modified form of the invention in which the liquified fluorocarbon gas is contained within a pocket formed in the beverage container;

FIG. 4 is a view similar to FIG. 1 showing a third modified form of the invention;

FIG. 5 is a view similar to FIG 1 showing a fourth modified form of the invention in which the liquified fluorocarbon gas is contained within a cartridge associated with the dispensing spigot;

FIG. 6 is a sectional view of the dispensing spigot of FIG. 5;

FIG. 7 is a view similar to FIG. 1, showing a further modified form of the invention; and

FIG. 8 is a view similar to FIG. 1 showing another modified form of the invention.

FIG. I is a diagrammatic illustration of a dispensing unit constructed in accordance with the invention and including a container 1 adapted to contain a beverage 2 having carbon dioxide dissolved therein. The container can be a keg, can, bottle, plastic or paper disposable carton, or the like, and can have any desired shape or configuration.

The beverage 2 can be a malt beverage, such as beer or ale, wine or a soft drink and contains in excess of 0.2 percent by weight of dissolved carbon dioxide and generally in the range of 0.4 percent to 0.5 percent by weight of dissolved carbon dioxide.

The beverage is dispensed or withdrawn from the container 1 through a conventional spigot 3 which is secured within an opening in the lower portion of the wall of the container and is connected to a coil 4 which extends to the bottom of the container.

A cartridge 5 is connected within an opening in a wall 6 bordering a recess 7 in the upper portion of the container 1 above the level of the beverage, and the cartridge contains a liquified fluorocarbon gas. The cartridge 5 itself is a conventional type and forms no part of the invention. The cartridge 5 includes a rubber or flexible seal which is punctured by the sharp end of a nipple 8 extending outwardly from the container. A check valve 9 can be located within the nipple 8 and permits the flow of gas from the cartridge 5 to the headspace of the container 1 but prevents the flow of fluid in the opposite direction. The check valve 9 in not essential to the operation of the invention and merely prevents the beverage within the container 1 from splashing or flowing into the cartridge 5 in the event the container may be inverted or tilted.

As there is free flow of the fluorocarbon gas between the cartridge 5 and the headspace of the container 1, the pressure within the container is substantially the vapor pressure of the liquified gas and is independent of the volume of the headspace in the container.

The liquified fluorocarbon gas contained within the cartridge 5 can be either a single compound or a mixture of various liquified fluorocarbons. The invention is not limited to any specific fluorocarbon or combination of fluorocarbons, and any food compatible, nontoxic, liquified fluorocarbon or mixture of liquified fluorocarbons can be used which will provide a vapor pressure sufficient to maintain the carbon dioxide in solution in the beverage. For beer the vapor pressure should be in the range of to p.s.i.g. at 45 F., and preferably about 17 to 18 p.s.i.g.

The liquified fluorocarbon gases are chemically insert nontoxic and are sufficiently stable to hydrolysis so that they do not increase the fluoride ion content of the beverage to any objectionable extent and thus have no adverse effect on the odor, taste, appearance or texture of the beverage. Examples of liquified fluorocarbon gas which can be used are perfluorocyclobutane, chlorotrifluoromethane, tetrafluoromethane, chloropentafluoroethane, and mixtures thereof. It has been found that a mixture of about 10 to 15 percent by weight of chloropentafluoroethane and to percent by weight of perfluorocyclobutane is a particularly satisfactory composition to be used as the liquified fluorocarbon gas, for it develops a vapor pressure in the range of about 17 to 20 p.s.i.g. at 45 F.

The amount of the liquified fluorocarbon gas to be used in the cartridge 5 depends upon the volume of the container, the volume of the beverage to be dispensed, and the temperature involved. The amount of the liquified fluorocarbon gas to be used in any particular instance can be readily calculated and is generally slightly more than the amount of liquified gas necessary to provide a uniform vapor pressure for the entire empty volume of the container at normal temperature conditions.

As the beverage 2 is drawn through the spigot 3, the headspace in the container 1 will be increased thereby reducing the pressure of the headspace and causing additional quantities of the liquified fluorocarbon gas in cartridge 5 to vaporize to maintain the vapor pressure within the headspace at the desired level and prevent the carbon dioxide from coming out of solution in the beverage. While the precise mechanism by which the fluorocarbon gas in the headspace acts to suppress the dissolution of the carbon dioxide is not known, it is believed, in the absence of sever agitation, that a nonequilibrium condition is achieved which may contribute to a variation from the gas laws. As a beverage such as beer is normally not agitated once it is tapped, the invention enable the beer to be retained for long periods without the loss of any appreciable dissolved carbon dioxide.

As the liquid fluorocarbon gas is located in a reservoir outside of the container, 1, the heat required for the vaporization of the liquified gas can be extracted from the surroundings rather than from the beverage itself, which is normally at a chilled temperature, and this increases the rate of vaporization and the rate of recovery of the vapor pressure within the headspace.

FIG. 2 shows a modified form of the invention in which the liquified fluorocarbon gas is contained within a float 10 which is adapted to float on the upper surface of the beverage 2. The upper end of float 10 is provided with an outlet opening 11 and a check valve 12 is located within the outlet 9. The check valve 12 permits the free flow of vapor from the interior of the float 10 to the headspace of the container but prevents the flow of fluid in the opposite direction. As in the case of the first embodiment, the check valve 12 serves to prevent the beverage from splashing or flowing into the float 10 in the event the container is tilted or jolted.

The embodiment shown in FIG. 2 operates in a manner similar to that of FIG. 1. As the beverage 2 is drawn from the container through the spigot 3, the volume of the headspace will be increased, reducing the pressure in the headspace. This will result in the vaporization of additional quantities of the liquified fluorocarbon gas which will flow out through the outlet 11 of float 10 into the headspace and restore the pressure within the headspace and prevent or substantially retard the dissolution of the carbon dioxide from the beverage.

FIG. 3 shows a second modified form of the invention in which the liquified fluorocarbon gas is contained within reservoir or punch 13 molded integrally with the side wall of the container 1. A resilient rubber or plastic flapper valve 14 is mounted within the opening 15 connecting the reservoir 13 with the interior of the container 1. As the beverage 2 is withdrawn from the container, additional quantities of the liquified gas in reservoir 13 will vaporize and pass through the valve 14 to the headspace of the container 1 to maintain the desired vapor pressure in the headspace and prevent dissolution of the carbon dioxide gas.

FIG. 4 shows another modified form of the invention using a different type of cartridge for the liquified gas. In this embodiment, a tube 16 extends through an opening in wall 6 of container 1, and a rubber or plastic flapper valve 17 is connected to the inner end of tube 16. Flapper valve 17 serves as a check valve to permit the flow of gas into the container and to prevent the flow of gas into the container and to prevent the flow of gas in the opposite direction.

A cartridge containing the liquified fluorocarbon gas is located in recess 7 of the container and a sleeve 19 extends outwardly from the cartridge and is positioned around the outer end of tube 16. Mounted for sliding movement within sleeve 19 is a plunger 21) having a series of holes therein, and plunger 20 is secured to one end of stem 21 while a valve 22 is carried on the opposite end of stem 21. Valve 22 is urged against valve seat 23 by spring 24 which is positioned between plunger 26 and a spring seat 25. When sleeve 19 is entered over the tube 16, the end of tube 16 pushes the plunger 20 inwardly against the force of spring 24 to open the valve 22.

The structure of FIG. 4 operates in a manner similar to that described with respect to the prior embodiment. As the beverage is drawn from the container, additional quantities of the liquified gas in cartridge 198 will vaporize and flow through tube 16 and valve 17 to the headspace of the container to maintain the necessary counter balancing vapor pressure to prevent dissolution of the carbon dioxide from the beverage.

FIGS,. 5 and 6 illustrate another modified form of the invention in which the vaporized fluorocarbon gas is admitted to the headspace of the container through the dispensing assembly, In this embodiment, the springer 26 is located at the upper end of the container 1 and a discharge tube 27 is connected to the spigot and is locate within the spigot for reducing the pressure of the beverage being dispensed and a vertical riser section 29 which extends downwardly from coiled section 28 to a location adjacent the bottom of the container. As best shown in FIG. 6 and tube 27 communicates with a passage 30 in spigot 26 and the passage is adapted to be opened or closed by a cylindrical valve 31 which rotates within a socket formed in the spigot. Valve 31 has an L-shaped passage 32 and when the valve is in the position shown in FIG. 6, passage 32 is out of alignment with passage 30, thereby closing off the flow of liquid through passage 30. By rotating valve 31, passage 32 will be brought into alignment with passage 30 and outlet passage 33 so that the beverage can flow from the container through the passages 30, 32 and 33.

Spigot 26 is also provided with a second passage 34 which communicates with the headspace in the container above the level of the beverage, and the passage 34 serves to conduct a fluorocarbon gas to the headspace. In this regard, valve 31 is provided with an opening 35 which, when the valve is rotated counterclockwise, provides communication between passage 34 and a valve housing 36 which is secured to the valve 31 and extends through a slot 37 in spigot 26. Housing 36 houses a check valve 38 and the outer end of the housing is formed with a sharp nipple 39 that punctures a resilient seal in the end of a cartridge 40 containing the liquified fluorocarbon gas. Cartridge 40 and check valve 38 are similar in structure and function to cartridge 5 and check valve 9 of the first embodiment.

When the valve is pivoted upwardly, the liquid dispensing line 30 is closed and the passage 35 connects housing 36 to passage 34 so that vaporized fluorocarbon gas can freely flow to the headspace of the container to maintain the necessary counterbalancing vapor pressure in the headspace.

When it is desired to draw the beverage from the container, the cartridge 46, which serves as a handle, is pivoted downwardly, rotating valve 31 and moving passage 32 of valve 31 into alignment with passages 30 and 33 to permit the beverage to flow from the spigot, as shown in FIG. 6. Simultaneously, valve passage 35 is moved out of communication with passage 34 and housing 36 so that the vaporized fluorocarbon gas cannot flow to the headspace of the container when the cartridge is pivoted downwardly.

FIG. 7 illustrates a further modified form of the invention in which the vaporized fluorocarbon gas is admitted to the headspace of the container through the dispensing assembly during periods when the beverage is being drawn from the container. In this embodiment, the dispensing spigot 41 in includes a body 42 which is connected within an opening in the container 1. A generally cylindrical valve 43 is mounted for rotation within a complimentary opening in the valve body and the position of the valve 43 is controlled by a handle 44 attached to the valve.

The valve 43 includes a passage 45 which establishes communication between a discharge passage 46 and a passage 47 when the valve is in the open position. When the valve is in the closed position the passage 45 will be out of communication with both the

passages

46 and 47.

The inner end of passage 47 is connected to a dispensing tube 48 which is located within the container and the beer or other beverage is adapted to be drawn through the tube 48 to the dispensing spigot 41.

1n addition, the valve 43 is provided with a passage 49 which is adapted to provide communication between the passage 50 and passage 51 when the valve is in the open position. Passage 511 is connected to a riser 52 located within the container, and the upper end of the riser communicates with the headspace above the level of the beverage 2. The passage 51 is connected by a tube 53 to a container 54 which contains a quantity of a liquified fluorocarbon gas 55. Tube 53 is provided with a restricted opening or orifice 56.

In the prior embodiments a mixture of liquified fluorocarbon gases was employed to provide a free vapor pressure in the range of 15 to 20 p.s.i.g. at 45 F. However, with the use of the structure of FIG. 7 it is possible to employ a single liquified fluorocarbon gas which has a free vapor pressure considerably higher than the range of 15 to 20 p.s.i.g. In the construction of FIG. '7, the line from liquified fluorocarbon gas container 54 to the headspace is open only when the beverage is being dispensed, and by correlating the size of the orifice 56 with the flow rate of the beverage from the container, an amount of fluorocarbon vapor can be admitted to the headspace during the period of dispensing to maintain the vapor pressure within the headspace at the desired value of IS to 20 p.s.i.g., even through the free vapor pressure of the liquified fluorocarbon gas is considerably high than this value.

The structure of FIG. 7 operates in the manner described with respect to the prior embodiments and the pressure of the fluorocarbon gas in the head space acts to substantially prevent the dissolution of the carbon dioxide from the beverage as the beverage is drawn.

FIG. 8 was a further modified form of the invention in which the container 1, is provided with dispensing spigot 57, which is connected to a dispensing tube 53 in the container. When the spigot 57 is opened, the beverage from the container will be drawn through the tube 58 and discharged through the spigot 57 in a conventional manner. In this embodiment a liquified fluorocarbon gas 59 is contained within a container 60 mounted within the container. As in the case of the embodiment shown in FIG. 7, the liquified fluorocarbon gas 60 can have a free vapor pressure considerably above the range of 15 to 20 p.s.i.g. which is the desired vapor pressure in the headspace of the container.

The upper end of the container 60 defines a valve seat 61 which is closed off by a valve 62 carried by stem 63. The upper end of stem 63 is connected to a flexible pressure responsive member or diaphragm 64 which is connected across a casing 65. Casing 65 is attached to the wall of the container by brackets 66. The diaphragm 64 is urged downwardly to bias the valve 62 to the open position by a spring 67 which is interposed between the diaphragm and the upper end of the casing 65. In addition, the lower end of the casing 65 is connected to the headspace of the container by a riser 68.

In this embodiment, the force of the spring 67 acts against the combined pressure of the fluorocarbon gas within the con tainer 611 and the pressure of the fluorocarbon vapor in the headspace. When the pressure in the headspace drops due to dispensing of the beverage, the spring 67 will act to open the valve 62 to permit additional quantities of the fluorocarbon vapor to escape through the riser 68 to the headspace. When the combined pressure of the vapor within the headspace and the vapor within the upper end of the container 59 equalizes the spring force, the valve will close.

As previously mentioned, the structure shown in FIG. 8 is adapted to employ a single liquified fluorocarbon gas which can have a free vapor pressure substantially in excess of the 15 to 20 p.s.i.g. vapor pressure desired in the headspace of the container. However, due to the valving arrangement the vapor pressure in the headspace is maintained at the desired value of 15 to 20 p.s.i.g.

The following tests illustrate the improvement in the retention of dissolved carbon dioxide in the beverage by use of the system of the invention as compared to a system in which the liquified fluorocarbon gas is in direct contact with the beverage.

An 8.6 liter tank was filled with approximately 8 liters of beer under about 15 p.s.i.g. pressure. The tank had previously been purged with carbon dioxide gas, and about 140 grams of chloropentafluoroethane and 25 grams of chloropentafluoroethane were added directly to the tank so that the liquified fluorocarbon mixture was in direct contact with the beer.

The tank was maintained at a temperature of about 45 F. and samples of beer were withdrawn initially and every 2 hours daily until the tank was drawn down to the outlet level and was nearly empty. The beer in the tank was not agitated during the testing period. The resulting table shows the carbon dioxide content of the beer at various timed intervals and draws.

TABLE I Time Total Average CO (hours) Draw Content of (mL) Beer (kw/w) 385 0.446 4 l2 l0 0. 0 24 2045 0.382 28 2880 0.360 48 3700 0.314 72 5155 0.30l

TABLE II Time Total Average CO, (hours) Draw Content of (ml.) Beer (kw/w) From the above table I it can be seen that the carbon dioxide content of the beer was originally 0.445 percent and this dropped considerably to a value of 0.301 percent after 3 days or 72 hours, indicating a substantial loss in the dissolved carbon dioxide of the beer during this period.

A second test was run in which an 8.6 liter tank was filled with approximately 8 liters of beer under about p.s.i.g. pressure. The tank had previously been purged with carbon dioxide gas. A pressure bottle charged with 280 grams of'perfluorocyclobutane and 50 grams of chloropentafluoroethane was connected to the top of the tank and arranged so that the liquified fluorocarbon gas mixture remained in the bottle while the fluorocarbon gas escaped and filled the headspace above the level of the beer.

Samples of beer were withdrawn initially and at 4 hour intervals and the beer in the tank was not agitated during the test period. The results of the testing are shown in the following table which sets forth the carbon dioxide content of the beer at various time intervals and draws:

From the above table ll it can be seen that the carbon dioxide content of the beer remains substantially constant for a period of 72 hours or 3 days.

A third test was run similar to the second test described above except the pressure bottle was charged with 102 grams of perfluorocyclobutane and 18 grams of chloropentafluoroethane. Samples of beer were drawn for carbon dioxide analysis initially and at four hour intervals and the results indicated that the carbon dioxide content of the beer remained substantially constant for a 72-hour period.

The dispensing unit of the invention is self-regulating and provides a constant counterbalancing pressure on the carbon dioxide containing beverage at all times regardless of the amount of beverage in the container. The counterbalancing pressure is achieved without the use of expensive pressureregulating equipment thereby enabling the dispensing unit to be used for small, portable, disposable dispensing units.

The pressure of the fluorocarbon gas in the headspace of the container achieves an unusual and unobvious affect in retarding or substantially preventing the dissolution of the carbon dioxide from the beverage for extended periods of time. This result is unique and is opposed to that which would normally be expected.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. An apparatus for containing and dispensing a beverage, comprising a container, a beverage disposed within the container and containing at least 0.2 percent by weight of dissolved carbon dioxide, the upper end of the container being spaced above the upper surface of the beverage to provide a headspace, dispensing means for dispensing the beverage from the container, a reservoir to contain a liquitied fluorocarbon gas that is insoluble in the beverage, said liquifled gas being out of direct contact with said beverage, and conduit means connecting the reservoir and the headspace whereby fluorocarbon gas is present in the headspace and exposed to the beverage, the vapor pressure of the fluorocarbon gas in the headspace being greater than the partial vapor pressure of the dissolved carbon dioxide to substantially retard the dissolution of the carbon dioxide from the beverage as the beverage is drawn from the container.

2. The apparatus of claim 1, wherein said liquified fluorocarbon gas comprises a mixture of liquifled fluorocarbon gases having a combined free vapor pressure in said range.

3. The apparatus of claim 1, in which the liquid fluorocarbon gas comprises a mixture of chloropentafluoroethane and octafluorocyclobutane.

4. The apparatus of claim 3, in which the mixture comprises from 10 to 15 percent by weight of chloropentafluoroethane and to percent by weight of octafluorocyclobutane.

5. The apparatus of claim 1, and including a check valve in said conduit means, said check valve being arranged to permit the flow of fluid in a direction from said reservoir to said headspace and prevent the flow of fluid in the opposite direction.

6. The apparatus of claim 1, in which the reservoir is located substantially at, or above, the upper level of the beverage in the container.

7. The apparatus of claim 1, in which the reservoir is located outside the container.

8. The apparatus of claim 1, in which the reservoir is a float disposed to float on said beverage and said conduit means is located in the upper end of the float above the level of the beverage and communicates directly with said headspace.

9. The apparatus of claim 1, wherein said beverage contains from 0.4 percent to 0.5 percent by weight of dissolved carbon dioxide.

10. The apparatus of claim 9, wherein the beverage is beer.

11. The apparatus of claim 1, wherein the vapor pressure of the fluorocarbon gas in the headspace is in the range of 15 to 20 p.s.i.g. at 45 F.

12. The apparatus of claim 11, wherein the liquified fluorocarbon gas has a free vapor pressure substantially above the range of 15 to 20 p.s.i.g. at 45 F., and said apparatus includes regulating means located in said conduit means for regulating the flow of fluorocarbon gas from said reservoir to said headspace to thereby maintain the vapor pressure in the headspace in said range.

13. The apparatus of claim 12, wherein said regulating means includes valve means in said conduit means, and means responsive to the drawing of beverage from said container opening said valve means to admit fluorocarbon gas from said reservoir to said headspace.

114. The apparatus of claim 13, wherein the flow rate of fluorocarbon gas through said conduit means when said valve means is open is correlated with the flow rate of the beverage from the container to maintain a vapor pressure in said range in said headspace.

15. The apparatus of claim 12, wherein said regulating means includes valve means in said conduit means, and means responsive to a decrease in pressure in said headspace for opening said valve means to admit fluorocarbon gas from said reservoir to said headspace.

16. The apparatus of claim 13, wherein said dispensing means includes an outlet conduit in said container for the discharge of said beverage, said valve means being disposed to open and close said outlet conduit, and said dispensing means comprises an operating member connected to the valve means for moving the valve means between the open and closed positions, said valve means simultaneously opening and closing said first conduit means to thereby simultaneously control the admission of fluorocarbon gas to the headspace.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,613,954 Dated October 19, 1971 Inventor(s) PETER D. BAYNE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 9 Cancel after "drinks", column 1, line 13, After "taining" delete "about", first occurrence, column 1, line 43, Cancel "a" and substitute therefor -'---as---,

Column 1, line 49, Cancel "an" and substitute therefor ---and--- Column 1, line 54, Cancel "a", first occurrence, and substitute therefor --as---, Column 1, line 58, Cancel "is" and substitute therefor ---it---, Column 1, line 61, Cancel "embraces" and substitute therefor ---membrances---, Column 2, line 2, Cancel "direction" and substitute therefor --direct--, Column 2,

line 45, Cancel "95" and substitute therefor ---90---, Column 2, line 66, Cancel "changers" and substitute therefor ---changes--- Column 3, line 49, Cancel "in" and substitute therefor ---is---, Column 4, line 24, Cancel "sever" and substitute therefor ---severe---, Column 4, line 27, Cancel "enable" and substitute therefor ---enables---, Column 4, line 61, Cancel "punch" and substitute therefor --pouch-, Column 5, line 1, Delete "prevent the flow of gas into the container and to", Column 5, line 17, Cancel "198" and substitute therefor ---l8--,

Colum 5, line 25, Cancel the comma and substutute therefor a period, Column 5, line 26, Cancel "springer" and substitute therefor ---spigot---, Column 5, line 28, Cancel "locate" and substitute therefor --located---, After "the", first occurrence insert ---container. Tube 27 includes a coiled section 28 located adjacent the--, column 5, line 32, Cancel "and" and substitute therefor (a comma)---,

Column 5, line 74, Cancel "in", second occurrence, Column 6, line 29, Before "liquidified" insert ---the---, column 6,

line 36, Cancel "through" and insert ---though---, Column 7, line 16, Cancel "chloropentafluoroethane" and substitute therefor ---octafluorocyclobutane---, Column 7, lines 45-59, Cancel Table II" and insert it in Column 8, line 3 after "drawsz", Column 7, line 60, Cancel "0.445" and substitute therefor ---O.446--- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,613,954 Dated OCtObGI 19, 1971 Peter D. Bayne Inventor(s) PAGE 2 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [73] "J05. Schlitz Brewing Company" should read Nutrico, Inc.

Signed and sealed this 15th day of August 1972.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 RM PO-.O5O (10-69) a u.s. sovzanuzur PRINTING OFFICE on o-ass-au

Claims

1. An apparatus for containing and dispensing a beverage, comprising a container, a beverage disposed within the container and containing at least 0.2 percent by weight of dissolved carbon dioxide, the upper end of the container being spaced above the upper surface of the beverage to provide a headspace, dispensing means for dispensing the beverage from the container, a reservoir to contain a liquified fluorocarbon gas that is insoluble in the beverage, said liquified gas being out of direct contact with said beverage, and conduit means connecting the reservoir and the headspace whereby fluorocarbon gas is present in the headspace and exposed to the beverage, the vapor pressure of the fluorocarbon gas in the headspace being greater than the partial vapor pressure of the dissolved carbon dioxide to substantially retard the dissolution of the carbon dioxide from the beverage as the beverage is drawn from the container.

2. The apparatus of claim 1, wherein said liquified fluorocarbon gas comprises a mixture of liquified fluorocarbon gases having a combined free vapor pressure in said range.

4. The apparatus of claim 3, in which the mixture comprises from 10 to 15 percent by weight of chloropentafluoroethane and 85 to 90 percent by weight of octafluorocyclobutane.

10. The apparatus of claim 9, wherein the beverage is beer.

11. The apparatus of claim 1, wherein the vapor pressure of the fluorocarbon gas in the headspace is in the range of 15 to 20 p.s.i.g. at 45* F.

12. The apparatus of claim 11, wherein the liquified fluorocarbon gas has a free vapor pressure substantially above the range of 15 to 20 p.s.i.g. at 45* F., and said apparatus includes regulating means located in said conduit means for regulating the flow of fluorocarbon gas from said reservoir to said headspace to thereby maintain the vapor pressure in the headspace in said range.

14. The apparatus of claim 13, wherein the flow rate of fluorocarbon gas through said conduit means when said valve means is open is correlated with the flow rate of the beverage from the container to maintAin a vapor pressure in said range in said headspace.