Intermediate pressure dispensing method for a carbonated beverage

Information

  • Patent Grant
  • 6530400
  • Patent Number
    6,530,400
  • Date Filed
    Tuesday, February 5, 2002
    22 years ago
  • Date Issued
    Tuesday, March 11, 2003
    21 years ago
Abstract
A carbonated beverage is conveyed from a source to a closed reservoir at a first pressure level. The pressure in the reservoir is controlled by selectively venting gas and adding pressurized gas to the reservoir to maintain the carbonated beverage at a second pressure level that is less than the first pressure level and substantially greater than atmospheric pressure. The carbonated beverage is dispensed from the reservoir into a serving container by reducing the pressure in the reservoir to substantially atmospheric pressure and then opening an outlet valve. During prolonged periods when dispensing is not occurring, the pressure in the reservoir may be increased to prevent degassing of the carbonated beverage. In that case, the reservoir pressure is reduced to the second pressure level before another dispensing operation.
Description




STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT




Not Applicable




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to equipment for dispensing a carbonated beverage into an open container from which the beverage will be consumed; and more particularly to such equipment in which the dispensing occurs in a manner that minimizes foaming of the beverage.




2. Description of the Related Art




It is common for carbonated beverages, such as soda and beer, to be supplied in a sealed canister or keg which then is connected to a tap at an establishment, such as one that serves food. As used herein the term “establishment” refers to a business or a residence. Pressurized gas, such as carbon dioxide, is injected into the keg to force the liquid beverage through an outlet tube to the tap from which it is dispensed into various sizes Of cups, mugs and pitchers.




The carbonated beverage usually foams upon entering the serving container. As a consequence, personnel operating the tap typically fill the serving container until the level of foam reaches the brim and then wait for the foam to settle before adding additional beverage. In some instances several iterations of this process are required before the container is filled with liquid to the proper serving level. Such “topping off” necessitated by the foaming of the beverage prolongs the dispensing operation and impedes the ability to fully automate carbonated beverage dispensing.




Automated dispensing is particularly useful in large volume carbonated beverage operations, such as sports arenas and stadiums, where it is desirable to fill each container to the full serving level as fast as possible with minimal waste.




U.S. Pat. No. 5,603,363 describes a dispensing system that satisfies that desire. The carbonated beverage is fed into an elevated tank that is open to the atmosphere so that the beverage stored therein is at atmospheric pressure at all times. A spout is located beneath the tank and has a valve through which the beverage flows into a serving container. Selective operation of the valve and movement of the serving container enable rapid dispensing with minimal foaming. A drawback of this system is that the tank is open to the atmosphere. Thus the beverage tends to degas upon prolonged storage in the tank. In addition, there is a concern that bacteria and other substances may enter the open tank and contaminate the beverage therein, especially between hours of operation of the beveratte establishment.




Alternative systems, such as described in U.S. Pat. No. 3,881,636, employs a closed tank with a vent tube at the top of the tank that provides a restricted passage to the atmosphere. The beverage is fed to the tank under the same pressure as in the keg and is maintained substantially at that elevated pressure until a spout is opened to fill a glass. At that time the tank pressure is reduced to the atmospheric level before the valve on the spout is opened. Upon completion of the dispensing operation the tank is brought back to the keg pressure. In a high volume dispensing establishment, this latter type of dispensing system has the disadvantage that time is lost while the reservoir is brought down to atmospheric pressure before the spout is opened. A further delay results from having to raise the tank to the keg pressure in order replenish the beverage in the tank. Thus it is desirable to increase the speed of dispensing further.




SUMMARY OF THE INVENTION




A method for dispensing a carbonated beverage conveys the beverage from a source into a closed reservoir at first pressure level that is greater than atmospheric pressure. In the case of beer, this first pressure typically is the internal pressure of the beer keg as shipped from the brewery, which pressure is known as the “rack pressure.” The carbonated beverage then is dispensed from the reservoir into an open container.




While being held in the reservoir, the carbonated beverage is maintained at a second pressure level that is less than the first pressure level and substantially greater than atmospheric pressure. This second pressure level is referred to as the “holding pressure.” Preferably the second pressure level is at least one psi, and five psi has been found particularly desirable for holding beer at reduced temperatures to minimize degassing. When it is desired to dispense the carbonated beverage into a serving container, the reservoir pressure is reduced to substantially atmospheric pressure. With the reservoir at substantially atmospheric pressure, the carbonated beverage flows into the container with minimal foaming as the beverage is exposed to a relatively small pressure differential.




Another aspect of the dispensing system. relates to opening a valve through which the carbonated beverage flows from the reservoir into the serving container. The valve is opened while the fluid inlets to the reservoir are closed, thereby preventing any additional beverage from entering the reservoir. With the inlets closed, the weight of the carbonated beverage in the spout causes the pressure in the reservoir to decrease below atmospheric pressure, thereby minimizing the flow of beverage into the container as the valve opens. After that valve has opened to a point at which the risk of foaming is negligible, a fluid, such as carbon dioxide for example, is introduced to raise the pressure in the reservoir to substantially the atmospheric pressure or greater. It has been found that increasing the reservoir pressure after the valve opens can improve the dispensing rate or enhance the presentation of the beverage being poured. At the end of the dispensing operation, pressure in the reservoir is allowed to decrease below atmospheric pressure to reduce flow of the carbonated beverage from the reservoir before the valve is closed.




In the preferred operation of the dispensing system, the pressure of the reservoir is raised to the first pressure level during prolonged periods of inactivity, such as when the food service establishment is closed. That higher pressure level enables the carbonated beverage to be stored for such a prolonged time without degassing. The reservoir pressure then is reduced to the second pressure level upon commencement of another dispensing operation.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a schematic diagram of a beverage dispensing system according to the present invention;





FIGS. 2 and 3

illustrate a cam mechanism which drives a valve of the beverage dispensing system;





FIG. 4

is a graph relating the opening distance of a valve in the beverage dispensing system to time; and





FIG. 5

is a graph of the pressure in a reservoir while beverage is being dispensed into a container.











DETAILED DESCRIPTION OF THE INVENTION




With initial reference to

FIG. 1

, a beverage dispensing system


10


receives a fully mixed carbonated beverage, such as beer or soda from a keg


12


. A source of pressurized gas, for example a cylinder


14


of carbon dioxide, is connected by a pressure regulator


16


to an inlet of the keg


12


. The pressure regulator


16


maintains the internal pressure of the keg at a first level recommended by the brewer of the beer. A pressure of 15 psi is commonly used for many beers. It should be understood that this pressure may deviate ±2 psi and still be considered substantially at the recommended first pressure level. Alternatively, a compressor can apply pressurized air to the keg, or a pump system can be used to transport the beverage from the keg


12


to the beverage dispensing system


10


. The keg pressure is commonly referred to as the “rack” pressure, and may be applied to several kegs within the establishment at which the beverages are being served.




The application of pressure to the keg


12


forces the beverage from an outlet through a dispensing line


18


. The beverage line


18


passes through an internal coil of a chiller


20


which lowers the temperature of the beverage to a desired dispensing temperature. Although many establishments, store the keg


12


in a walk-in refrigeration unit, that may not be the case for a high volume establishment. Also when a keg is exhausted, a replacement may be obtained from an unrefrigerated area. After being chilled, the beverage flows through line


22


to an inlet valve


24


of a beverage reservoir


26


. The inlet valve


24


is operated by a gas driven actuator


25


in response to an electric signal. Alternatively, an electric solenoid operated inlet valve can be used.




The reservoir


26


has a closed inner chamber


28


into which the beverage flows when the inlet valve


24


is opened. A jacket of the reservoir


26


forms an outer cavity


30


which extends around the inner chamber


28


. Chilled water is circulated through this outer cavity to maintain the contents of the inner chamber at the proper temperature. Specifically, a pump


32


draws water from the outer cavity


30


via an outlet line


34


and forces the water through a separate coil within the chiller


20


. This chills the water to the desired temperature and the chilled water then is returned through an inlet line


36


to the outer cavity


30


of the reservoir


26


. Baffles may be provided within the outer cavity


30


to ensure that the chilled water flows completely around the inner chamber


28


to maintain the beverage


38


therein at a relatively uniform temperature.




The beverage


38


partially fills the inner chamber


28


to a height that is detected by a level sensor


40


. The upper portion


42


of the closed inner chamber


28


is filled with gas, the pressure of which is sensed by a pressure transducer


46


in gas supply line


50


. Alternatively the pressure transducer can be mounted directly in the reservoir chamber


28


. When pressure in the inner chamber


28


needs to be increased, as will be described, a gas supply valve


44


is opened to convey carbon dioxide from tank


14


through a second pressure regulator


48


and gas supply line


50


to the upper portion


42


of the inner chamber. If the pressure within the inner chamber


28


is too great, a relief valve


52


is opened to vent that excess pressure to the ambient environment. Thus the fact that the beverage is held in a closed inner chamber


28


means that the beverage is maintained above atmospheric pressure at a level determined by operation of the gas supply valve


44


and the relief valve


52


. The valves


44


and


52


are electrically operated by signals from a controller


54


, in response to the signal from pressure transducer


46


.




During extended, repeated dispensing operations excess beverage foam may accumulate in the inner chamber


28


. Foam accumulation also may occur when a “mishandled” or “wild” keg


12


of the beverage is connected to the system. When foam occurs, it must be vented to the ambient environment. This processing of foam is required so that the level switch


40


does not responds to the presence of the foam which has a lower density relative to the liquid beverage. Consequently, as the reservoir


26


is replenished with liquid beverage


38


through inlet valve


24


, the excess foam is forced from the inner chamber


28


through the relief valve


52


.




The reservoir


26


includes a dispensing spout


60


extending downwardly therefrom. The flow of beverage through the spout


60


is controlled by a movable valve element


62


that is mounted at the lower end of a tube which extends vertically through the spout


60


and the reservoir


26


. An upper end of the tube


64


passes through a seal


65


and is connected to an actuator


66


, which raises and lowers the tube. That motion brings the valve element


62


into and out of engagement with the spout to allow beverage to flow into a container placed there beneath. The actuator


66


is operated by signals from the controller


54


, as will be described.




Referring to

FIG. 2

, the actuator


66


has bidirectional stepper motor


68


which rotates a shaft


70


. A cam disk


72


is attached to the remote end of shaft


70


. As shown in

FIG. 3

, the lower surface of the cam disk


72


forms a curved ramp


74


. A cam follower


76


has a wheel


78


which rides along a curved path, designated by broken lines


80


, on the bottom surface of the cam disk


72


. Thus, as the cam disk


72


is rotated clockwise or counter clockwise by stepper motor


68


, the cam ramp


74


forces the cam follower


76


up and down, as indicated by arrow


82


in FIG.


2


. This action causes the tube


64


, that is attached to the cam follower


76


, to move the valve element


62


against and away from the end of the spout


60


, thereby controlling the flow of beverage out of the spout.




A straight blade


88


extends from the shaft


70


and interrupts a light beam in an optical sensor


86


when the motor has rotated to the zero degree, or “home”, position at which the spout valve is closed. The controller


54


uses the signal provided by the optical sensor


86


and the positioning capability of the stepper motor


68


to accurately control the position of the spout valve element. Alternatively, a stepper motor that provides linear thrust along its shall, such as provided by a drive screw, could be used to provide the linear motion to drive the spout valve element, thereby eliminating the need for the cam disk


72


and follower


76


. This latter drive mechanism requires a different configuration of the optical sensor to detect the home position.




With reference to

FIG. 1

, a switch


90


is mounted on the valve element


62


and is depressed by the bottom of a beverage container placed underneath the spout


60


. The switch


90


is connected by a pair of wires


92


which run through the tube


64


emerging within the actuator


66


as shown in FIG.


2


. These wires connect to an input of the controller


54


.




The beverage is supplied to the reservoir


26


from the keg at a first pressure level that corresponds to the rack pressure of the keg. The pressure within inner chamber


28


of the reservoir


26


is maintained at a second pressure level that is referred to as the “holding pressure.” The second pressure level is greater than one psi and a level of at least five psi has been found particularly desirable for beer. Because the holding pressure is substantially above atmospheric pressure, at least one psi, and because the beverage in the reservoir is held at a relatively low temperature (e.g. less than 35° F.), degassing of the beverage is minimized during the relatively brief period of time that the beverage remains in the reservoir.




When a server desires to dispense the beverage, an open serving container is placed beneath the spout


60


and moved upward until the bottom of the container presses the switch


90


on the valve element


62


. This transmits a signal to the controller


54


indicating that a beverage dispensing operation should commence. If beverage is dispensed through the spout


60


at the holding pressure, turbulence will occur producing excessive foam in the beverage container which is an undesirable effect. As a consequence with reference to FIG.


5


. when the controller


54


initiates a pour cycle at time T


1


. the pressure relief valve


52


in

FIG. 1

is opened to vent the pressure within the inner chamber


28


to the outside environment. The pressure is decreased from the holding pressure P


2


to a dispensing pressure P


3


which is substantially at atmospheric pressure. It will be recognized that the precise atmospheric pressure fluctuates with meteorological changes. The objective is to reduce the pressure to a point at which minimal foaming occurs in the container as is achieved when the pressure in the reservoir equals that of the container. A slight pressure difference, ±1 psi for example, can exist without producing an excessive amount of foam which would deprive the customer of a full serving of the beverage.




When at time T


2


the pressure has reached the dispensing pressure P


3


, as indicated by the signal from pressure transducer


46


, the controller


54


activates the stepper motor


68


of the actuator


66


, which causes the valve element


62


to move away from the end of the spout


60


. This opens a passage for fluid to flow from the spout


60


into the serving container held there beneath.

FIG. 4

illustrates an exemplary movement of the valve member


62


during the dispensing interval, and thus the degree to which the valve is opened. The contour of pour provided by this movement of the valve member


62


is defined by characteristics of the beverage, the temperature of the beverage, and the pressure at which the pour is occurring. The shape of the contour can be varied by control of the stepper motor


68


to minimize the foam generation during the dispensing operation.




In prior systems, when the valve element cracks open, the beverage tends to flow through the initial small opening at a relatively high velocity which produces turbulence and thus foam in the serving container. This adverse effect is prevented by creating a negative pressure in the spout which restricts the beverage flow until the valve has opened to a point at which foaming will not occur. Specifically as the spout


60


opens, the gas supply valve


44


remains closed thus creating a slight vacuum due to the weight of the beverage in the reservoir. This limits the flow of beverage from the spout


60


to a very small quantity, which is particularly important for extremely carbonated beverages which foam easily. After the valve element


62


has opened significantly at time T


3


, the gas supply valve


44


is activated by controller


54


to introduce pressurized gas from source


14


into the reservoir and increase the pressure to the dispensing pressure P


3


. The rate at which the pressure is increased between times T


3


and T


4


regulates the velocity at which the beverage leaves the reservoir and thus can be configured according to the level of carbonation of the particular beverage.




The product continues to flow out of spout


60


between times T


4


and T


5


while pressure in the reservoir is maintained at the dispensing level P


3


. Alternatively, as shown by the dashed line


96


in

FIG. 5

, the controller


54


can operate the gas supply valve


44


and relief valve


52


to increase and decrease the pressure being applied to reservoir inner chamber


28


. Such pressure fluctuations are less than ±1 psi from atmospheric pressure. Dispensing at a greater deviation from atmospheric pressure requires careful control to avoid excessive foaming as the beverage is dispensed into the serving container. However, pressure fluctuations may be three psi or greater for heavy beers that are typically aerated when dispensed to produce a thick creamy head. Such is the case with Irish stout ales and seasonal dark beers. This increased pressure is needed to provide sufficient turbulence which produces the desired presentation of the beverage in the serving container, i.e. the desired foam head.




Because the pressure in the reservoir


26


is held to the controlled level P


3


during the dispensing cycle, the beverage flows from the spout at a controlled rate. At a sports venue, the serving containers for a given kind of beverage typically are the same size. As a consequence, the portion size is controlled by holding the spout open for a fixed period of time required to dispense the proper quantity of beverage. It should be noted that even if pressure level P


3


is varied during the dispensing cycle, the pressure variation and duration of the change are accurately controlled to allow the desired portion size to be repeatedly dispensed. When the controller


54


determines that the dispensing interval T


1


to T


5


has elapsed, the gas supply valve


44


is shut off while the conical valve element


62


remains open, thus creating a slight vacuum in the reservoir. The flow of the beverage through the spout


60


immediately slows dramatically due to the negative pressure. The beverage dispensing has essentially stopped without closing the spout valve, which, for a carbonated beverage, may be a very beneficial technique as turbulence due to movement of the valve element


62


is eliminated. Then at time T


6


, the stepper motor


68


is activated in the opposite direction, thereby closing the valve element


62


against the open end of the spout


60


and terminating the flow of beverage through the spout at time T


7


.




As beverage flows out of the spout


60


into the serving container, the level of beverage


38


within the reservoir's inner chamber


28


decreases which is detected by the level sensor


40


. The beverage can be replenished either during the dispensing operation or thereafter. Replenishing the beverage during dispensing permits the beverage flow into the reservoir to be used to control the reservoir pressure instead of or in addition to regulating the introduction of carbon dioxide from the tank


14


. In this case, the controller


54


responds to the signal from the level sensor


40


by opening the beverage supply valve


24


, thereby enabling cooled beverage from the chiller


20


to flow into the bottom of the inner chamber


28


. The rate at which additional beverage flows into the inner chamber


28


is independent of the flow rate through the spout


60


. In fact, in a preferred embodiment, the beverage flows through the spout


60


at a faster rate than the rate at which beverage enters the reservoir. As a consequence, the dispensing operation usually terminates before the beverage


38


within the inner chamber


28


has been replenished to the desired level. Regardless, the valve


24


remains open until the level sensor


40


indicates that the proper quantity of beverage is stored within the reservoir's inner chamber


28


.




While the beverage is entering the reservoir inner chamber


28


, the controller


54


monitors the inner chamber pressure via the signal from transducer


46


. Should the pressure of the inner chamber


28


deviate from the desired level, the controller


54


operates the relief valve


52


to lower the pressure or operates gas supply valve


44


to increase the pressure with additional carbon dioxide gas from cylinder


14


. Thus the reservoir pressure is maintained for proper dispensing.




After the dispensing operation terminates at time T


7


, the pressure within the inner chamber


28


is raised to the holding pressure P


2


to be ready for another dispensing operation. The reservoir pressure is increased by the controller


54


maintaining the pressure relief valve


52


closed and opening gas supply valve


44


to apply pressure regulated carbon dioxide from supply tank


14


to the upper region


42


of the reservoir's inner chamber


28


. While this occurs, the pressure within that inner chamber is monitored via a signal from pressure transducer


46


. Once the inner chamber has again reached the holding pressure P


2


at time T


8


, the gas supply valve


44


is closed. Thereafter, the controller


54


periodically checks the inner chamber pressure and operates valves


44


and


52


as necessary to maintain the holding pressure P


2


. By maintaining the beverage in the reservoir at the intermediate holding pressure that is between the rack and atmospheric pressure and at a reduced temperature, the amount of degassing that would occur at atmospheric pressure is reduced and upon commencement of dispensing the reservoir pressure does not have to decrease as much as it would if maintained at the rack pressure P


1


. Thus degassing is reduced while the beverage flow begins quickly when a dispensing operation commences.




When the beverage establishment closes, such as at the end of the business day, the reservoir


26


is brought up to the rack pressure P


1


as shown by the dashed line


98


in FIG.


5


. This will maintain the beverage stored in the reservoir at a pressure where minimal degassing occurs. The inner chamber pressure is lowered again to the holding pressure P


2


when the establishment reopens or at the commencement of the next dispensing operation. In instances where a relatively long time period (e.g. ten minutes) elapses after a previous dispensing operation, the reservoir pressure can be increased to the rack pressure P


1


to further limit the degassing.




The present beverage dispensing system employs a closed reservoir that prevents contaminants from adversely effecting the beverage being stored in the dispenser. At the same time, the pressure of the beverage is regulated so that it is stored at a relatively high pressure that prevents gas from escaping the beverage, and yet the pressure to a low level for proper pouring into a beverage container with foaming.




The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.



Claims
  • 1. A method for operating a system to dispense a carbonated beverage into a serving container at an establishment, that method comprising:connecting the system to a source which supplies the carbonated beverage at a first pressure level that is greater than atmospheric pressure; maintaining a reservoir of the system at a second pressure level that is less than the first pressure level and substantially greater than atmospheric pressure; transferring the carbonated beverage from the source to the reservoir that is maintained at the second pressure level; when dispensing the carbonated beverage into the serving container is desired, lowering pressure in the reservoir to substantially the atmospheric pressure; and dispensing the carbonated beverage from the reservoir into the serving container, after pressure in the reservoir is at substantially the atmospheric pressure.
  • 2. The method as recited in claim 1 wherein the second pressure level is greater than one psi.
  • 3. The method as recited in claim 1 wherein the second pressure level is substantially five psi.
  • 4. The method as recited in claim 1 wherein maintaining the carbonated beverage in the reservoir at a second pressure level comprises applying pressurized gas to the reservoir to increase pressure of the carbonated beverage, and venting gas from the reservoir to decrease pressure of the carbonated beverage.
  • 5. The method as recited in claim 1 wherein maintaining the carbonated beverage in the reservoir at a second pressure level further comprises transferring the carbonated beverage to the reservoir from the source during the dispensing.
  • 6. The method recited in claim 1 further comprising maintaining the carbonated beverage in the reservoir at substantially the first pressure level when the establishment is closed for business.
  • 7. The method recited in claim 1 further comprising raising pressure of the carbonated beverage in the reservoir to substantially the first pressure level when at least ten minutes has elapsed since a prior dispensing of the beverage.
  • 8. The method recited in claim 1 further comprising monitoring how much carbonated beverage is contained in the reservoir; and wherein the transferring occurs in response to the monitoring to maintain a predefined quantity of beverage in the reservoir.
  • 9. The method recited in claim 1 further comprising circulating a chilled fluid around an exterior surface of a chamber of the reservoir which chamber contains the carbonated beverage.
  • 10. The method recited in claim 1 wherein the dispensing comprises:opening a first passageway through which the carbonated beverage flows from the reservoir into the serving container; allowing pressure in the reservoir to go below atmospheric pressure; and thereafter opening a second passageway to introduce a fluid into the reservoir to raise the pressure in the reservoir to substantially atmospheric pressure.
  • 11. The method recited in claim 10 wherein the fluid is selected from a group consisting of the beverage and a gas.
  • 12. The method recited in claim 10 wherein the dispensing further comprises varying pressure in the reservoir while the carbonated beverage flows from the reservoir to control an amount of foaming of the carbonated beverage in the serving container.
  • 13. The method recited in claim 1 wherein the dispensing comprises:allowing pressure in the reservoir to go below atmospheric pressure to reduce flow of the carbonated beverage from the reservoir; and thereafter closing a passageway through which the carbonated beverage flows from the reservoir into the serving container.
  • 14. The method recited in claim 13 further comprising, after closing the passageway, raising pressure in the reservoir to the second pressure level.
  • 15. A method for dispensing a carbonated beverage into a serving container, that method comprising:transferring the carbonated beverage to a reservoir from a source, which supplies the carbonated beverage at a first pressure level that is greater than atmospheric pressure; sensing pressure in the reservoir; in response to the sensing, maintaining the carbonated beverage in the reservoir at a second pressure level that is less than the first pressure level and substantially greater than atmospheric pressure by selectively operating a relief valve to decrease pressure in the reservoir and by selectively operating a supply valve to add pressurized fluid to increase the pressure in the reservoir; when dispensing the carbonated beverage into the serving container is desired, lowering pressure in the reservoir to a third pressure level that is less than the second pressure level; and dispensing the carbonated beverage by operating a valve element to open a passageway from the reservoir to the serving container while the beverage is maintained in the reservoir substantially at the third pressure level.
  • 16. The method as recited in claim 15 wherein the third pressure level is substantially atmospheric pressure.
  • 17. The method as recited in claim 15 wherein the pressurized fluid is a gas.
  • 18. The method as recited in claim 15 wherein the pressurized fluid is the carbonated beverage.
  • 19. The method as recited in claim 15 wherein the first pressure level is substantially 15 psi.
  • 20. The method as recited in claim 15 wherein the second pressure level is greater than one psi.
  • 21. The method as recited in claim 15 wherein the second pressure level between one and five psi, inclusive.
  • 22. The method recited in claim 15 further comprising increasing the pressure of the carbonated beverage in the reservoir to the first pressure level when dispensing does not occur for a predefined period of time; and thereafter reducing the pressure of the carbonated beverage in the reservoir to the second pressure level prior to operating the valve element.
  • 23. The method recited in claim 15 further comprising monitoring how much carbonated beverage is contained in the reservoir; and wherein the transferring is in response to the monitoring to maintain a predefined quantity of beverage in the reservoir.
  • 24. The method recited in claim 15 further comprising circulating a chilled fluid around an exterior surface of a chamber of the reservoir that contains the carbonated beverage.
  • 25. The method recited in claim 15 wherein the dispensing comprises:maintaining the relief valve and the supply valve closed; opening the valve element so that pressure in the reservoir goes below atmospheric pressure; and at a predefined time after opening the valve element, opening the supply valve to raise the pressure in the reservoir to the third pressure level.
  • 26. The method recited in claim 15 wherein the dispensing comprises:reducing flow of the carbonated beverage from the reservoir by allowing pressure in the reservoir to go below atmospheric pressure; and thereafter closing the valve clement through which the carbonated beverage flows from the reservoir into the serving container.
  • 27. The method recited in claim 26 further comprising, after closing the valve raising pressure in the reservoir to the second pressure level.
  • 28. A method for dispensing a carbonated beverage into a serving container from a reservoir that contains a quantity of beverage and a volume of gas, that method comprising:transporting the carbonated beverage from a source to the reservoir at a first pressure level that is greater than atmospheric pressure; maintaining pressure within the reservoir at a second pressure level, that is less than the first pressure level and substantially greater than atmospheric pressure, by selectively venting gas from the reservoir and adding pressurized gas to the reservoir; when dispensing the carbonated beverage into the serving container is desired, lowering pressure in the reservoir to substantially the atmospheric pressure; when pressure in the reservoir is substantially the atmospheric pressure, opening a valve through which the carbonated beverage flows from the reservoir into the serving container; as the valve opens, allowing pressure in the reservoir to go below atmospheric pressure; and at a predefined time after opening the valve, introducing a fluid into the reservoir to raise the pressure in the reservoir to substantially atmospheric pressure.
  • 29. The method as recited in claim 28 wherein the second pressure level is greater than one psi.
  • 30. The method recited in claim 28 further comprising sensing a level of carbonated beverage in the reservoir; and wherein the conveying is in response to the sensing to maintain a predefined quantity of beverage in the reservoir.
  • 31. The method recited in claim 28 which further comprises terminating flow of the carbonated beverage into the serving container by:reducing flow of the carbonated beverage from the reservoir by allowing pressure in the reservoir to go below atmospheric pressure; and thereafter closing the valve through which the carbonated beverage flows from the reservoir into the serving container.
  • 32. A method for dispensing a carbonated beverage into a serving container at an establishment, that method comprising:storing the carbonated beverage in a reservoir at a given pressure level; opening a valve through which the carbonated beverage flows from the reservoir into the serving container; allowing pressure in the reservoir to go below atmospheric pressure; and thereafter introducing a fluid into the reservoir to raise the pressure in the reservoir to substantially atmospheric pressure.
  • 33. The method recited in claim 32 wherein the given pressure level is substantially greater than atmospheric pressure; and further comprising reducing pressure in the reservoir to substantially atmospheric pressure before opening the valve.
  • 34. The method recited in claim 32 which further comprises terminating flow of the carbonated beverage into the serving container by:allowing pressure in the reservoir to go below atmospheric pressure to reduce flow of the carbonated beverage from the reservoir; and thereafter closing the valve.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application No. 60/269,830 filed Feb. 20. 2001.

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Number Name Date Kind
3876107 Meindl et al. Apr 1975 A
3881636 D'Aubreby May 1975 A
3978900 Mencacci et al. Sep 1976 A
4560089 McMillin et al. Dec 1985 A
5566732 Nelson Oct 1996 A
5603363 Nelson Feb 1997 A
6237652 Nelson May 2001 B1
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Number Date Country
3435725 Apr 1985 DE
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Provisional Applications (1)
Number Date Country
60/269830 Feb 2001 US