AN APPARATUS AND A METHOD FOR GENERATING AND INFUSING A GAS INTO A LIQUID DRINK

Abstract

The present invention is directed towards a liquid drink dispensing apparatus. The apparatus comprises a gas generating component and a liquid drink dispensing component. The generated gas is supplied to the liquid drink dispensing component which infuses the generated gas into a liquid drink prior to dispensing the gas-infused liquid drink. The advantage of using a gas generating component is that the gas can be created on-site and no bottled gas needs to be used. This obviates the problems associated with purchasing, storing, using and replacing gas cylinders.

Claims

1. A liquid drink dispensing apparatus comprising: a gas generating component and a liquid drink dispensing component; whereby, the gas generating component generates a gas and supplies the generated gas to the liquid drink dispensing component which infuses the generated gas into a liquid drink prior to dispensing the gas-infused liquid drink.

2. (canceled)

3. A liquid drink dispensing apparatus as claimed in claim 1, wherein, the gas generating component comprises a gas generating hollow fibre membrane module which generates the gas by separating the gas from a gaseous mixture; and, the liquid drink dispensing component comprises a gas infusing hollow fibre membrane module to infuse the generated gas into the liquid drink.

4. A liquid drink dispensing apparatus as claimed in claim 2, wherein, the gas generating component comprises a compressor which supplies a compressed gaseous mixture to the gas generating module, and, a buffer tank which stores the generated gas from the gas generating module and supplies the generated gas to the liquid drink dispensing component; whereby, the gas generating component further comprises a pressure switch connected to the buffer tank such that the pressure switch controls the operation of the compressor based on the pressure level in the buffer tank.

5. A liquid drink dispensing apparatus as claimed in claim 4, wherein, the pressure switch sends a signal to a controller which then processes the signal from the pressure switch and, in turn, may transmit an activation signal to the compressor so as to activate the operation of the compressor.

6. A liquid drink dispensing apparatus as claimed in claim 4, wherein, the operation of the compressor is activated when the pressure level in the buffer tank falls below a preset minimum pressure level.

7. A liquid drink dispensing apparatus as claimed in claim 1, wherein, the gaseous mixture fed into the gas generating module is air and the gas generated by the gas generating module is nitrogen.

8. (canceled)

9. A gas infuser apparatus for infusing a gas into a liquid, wherein, the gas infuser apparatus comprises a gas generating component and a gas infusing component; whereby, the gas generating component generates a gas and supplies the generated gas to the gas infusing component which infuses the gas into a liquid.

10. (canceled)

11. A gas infuser apparatus as claimed in claim 9, wherein, the gas generating component comprises a gas generating hollow fibre membrane module which generates the gas by separating the gas from a gaseous mixture; and, the gas infusing component comprises a gas infusing hollow fibre membrane module to infuse the generated gas into the liquid.

12. A gas infuser apparatus as claimed in claim 10, wherein, the gas generating component comprises a compressor which supplies a compressed gaseous mixture to the gas generating module, and, a buffer tank which stores the generated gas from the gas generating module and supplies the generated gas to the gas infusing component; whereby, the gas generating component further comprises a pressure switch connected to the buffer tank such that the pressure switch controls the operation of the compressor based on the pressure level in the buffer tank.

13. A gas infuser apparatus as claimed in claim 12, wherein, the pressure switch sends a signal to a controller which then processes the signal from the pressure switch and, in turn, may transmit an activation signal to the compressor so as to activate the operation of the compressor.

14. A gas infuser apparatus as claimed in claim 12, wherein, the operation of the compressor is activated when the pressure level in the buffer tank falls below a preset minimum pressure level.

15. A gas infuser apparatus as claimed in claim 9, wherein, the gaseous mixture fed into the gas generating module is air and the gas generated by the gas generating module is nitrogen.

16. A process for infusing a liquid drink with a gas, including the steps: delivering a pressurised gaseous mixture into a gas generating module which is used to separate the gaseous mixture into a selected gas and an unwanted gas; delivering the selected gas to a gas infusing module which is used to infuse the generated gas into the liquid drink.

17. The process for infusing a liquid drink with a gas as claimed in claim 16, wherein, the gas generating module comprises a gas generating hollow fibre membrane module; and, the gas infusing module comprises a gas infusing hollow fibre membrane module.

18. The process for infusing a liquid drink with a gas as claimed in claim 17, wherein, the process further comprises extracting one of the selected gas or the unwanted gas through a side wall of the gas generating hollow fibre membrane module, and, discharging the other of the selected gas and the unwanted gas through an outlet of the gas generating hollow fibre membrane module.

19. The process for infusing a liquid drink with a gas as claimed in claim 17, wherein, the process further comprises passing the selected gas through a gas infusing hollow fibre membrane module, whereby the gas infusing hollow fibre membrane module comprises a plurality of hollow fibre tubes housed within a mixing chamber such that the selected gas emanates from one or more of the plurality of hollow fibre tubes and is infused into a liquid drink which has been fed in the mixing chamber.

20. The process for infusing a liquid drink with a gas as claimed in claim 16, wherein, the process includes purifying the selected gas downstream of the gas generating module before delivering the selected gas to the gas infusing module.

21. The process for infusing a liquid drink with a gas as claimed in claim 16, wherein, the process includes delivering the selected gas discharged from the gas generating module to a buffer tank and storing a quantity of the selected gas at a preset pressure in the buffer tank upstream of the gas infusing module and the process includes pressurizing the gaseous mixture upstream of the gas generating module by delivering the gaseous mixture through a compressor, a pressurized gas outlet of the compressor communicating with an inlet of the gas generating module, and the process comprises sensing the as Pressure within the buffer tank and controllin o eration of the compressor in response to said sensed gas pressure for maintaining the selected gas at a desired pressure in the buffer tank, and the process includes filtering the pressurized gaseous mixture in a filter mounted between he compressor and the gas generating module.

22. (canceled)

23. (canceled)

24. (canceled)

25. The process for infusing a liquid drink with a gas as claimed in claim 16, wherein, the process includes regulating the pressure of the gaseous mixture delivered to the gas generating module by means of a pressure regulator mounted upstream of the gas generating module, and the process comprises purifying the selected gas upstream of the gas infusing module, and the process comprises pumping the liquid drink from a liquid drink reservoir into the mixing chamber of the the gas infusing module.

26. (canceled)

27. (canceled)

28. The process for infusing a liquid drink with a gas as claimed in claim 16, wherein the gaseous mixture is air and the selected gas is nitrogen.

29. (canceled)

30. (canceled)

31. (canceled)

Description

DETAILED DESCRIPTION OF EMBODIMENTS

[0066] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:

[0067] FIG. 1 is a circuit diagram of a liquid drink dispensing apparatus for infusing a gas into a liquid drink in accordance with the present invention;

[0068] FIG. 2 is a schematic sectional elevational view of a gas infusing hollow fibre membrane module forming portion of the liquid drink dispensing apparatus of FIG. 1; and,

[0069] FIG. 3 is a circuit diagram of a liquid drink dispensing apparatus for infusing a gas into a liquid drink in accordance with a further embodiment of the present invention.

[0070] Referring to the drawings, there is provided a liquid drink dispensing apparatus indicated generally by reference numeral 100. The liquid drink dispensing apparatus 100 comprises a gas generation component 101 and a liquid dispensing component 103, whereby the gas generated by the gas generation component 101 is delivered to the liquid dispensing component 103 so that the generated gas can be infused into a liquid drink in the liquid dispensing component 103, prior to the gas-infused liquid drink being dispensed.

[0071] Gas is generated using a gas generating module, such as, in a preferred embodiment, a gas generating hollow fibre membrane module. These membrane modules are well-known in the art as being used in larger industrial applications. In the case of nitrogen generation, air is compressed and forced through hollow fibres which are semi-permeable. The permeability of the hollow fibres can be set so as to cause a separation of molecules when air is passed through the hollow fibre. Air is passed into one end of the hollow fibre and the oxygen (O.sub.2) molecules, the water vapour (H.sub.2O) and the carbon dioxide (CO.sub.2) molecules in the air as well as other impurities permeate out through the hollow fibre membrane however the nitrogen (N.sub.2) does not (or at least is much slower to permeate through) due to its molecular size and by feeding the air into one end of the hollow fibre at a certain pressure, causing a certain flowrate, the nitrogen will for the most part remain within the hollow fibre and will be expelled as substantially pure nitrogen out of an opposing end of the hollow fibre. As stated above, this is known in the art for use in other fields where large scale nitrogen production is required, but has never been considered for small levels of nitrogen production as is the case with the present invention. It will be readily appreciated that alternative types of gas generating modules may be used in place of a gas generating hollow fibre membrane module.

[0072] Referring to FIG. 1, and specifically to the gas generation component 101 of the liquid drink dispensing apparatus 100, there is provided an air intake 102 which supplies air, taken from the atmosphere, into a compressor 104. The compressor 104 draws the air through the air intake 102 and into the compressor 104. Compressed air discharged from the compressor 104 is fed through a filter 106 and a regulator 108 to remove impurities and moisture from the compressed air and to control the pressure of the compressed air as it is fed further along through the gas generation component 101. The filter 106 may preferably be a carbon filter. A non-return valve 110 is provided in advance of the gas generating hollow fibre membrane module 112 which separates nitrogen (N.sub.2) from the air as discussed hereinabove. A nitrogen purity level of approximately 97%-98% can be expected. The other elements of the air are released into the atmosphere from the gas generating hollow fibre membrane module 112. It will be appreciated that cooling coils may be used to cool air expelled from the compressor 104 and/or water separators may also be used to remove water from the compressed air. Such elements and components are well known in the art and will not be described in any further detail in this specification.

[0073] The nitrogen (N.sub.2) is fed onwards to a needle purity valve 114 which can be set to a specific purity setting. A purity in the range of 95%-99% is considered to be sufficient for infusing a liquid drink, and preferably a purity level of 97% is used as this is considered to be pure enough for use whilst higher purity levels do not offer an advantageous cost-benefit.

[0074] A further non-return valve 116 is provided in advance of a buffer tank 118. The nitrogen (N.sub.2) that has been generated is held in the buffer tank 118 and is held at a pressure equal to or greater than a preset minimum pressure level. In a preferred embodiment, the minimum pressure level shall be substantially 55 p.s.i. (pounds per square inch). In a further embodiment, the maximum pressure level in the buffer tank 118 is envisaged to be approximately 65 p.s.i. If nitrogen is released from the buffer tank 118 and the pressure level drops below the preset minimum pressure level, a pressure activated switch 120 will send a control signal to a controller 121. The controller 121 will process the signal from the pressure switch 120 and will then transmit an activation signal along a compressor control signal line 122 to activate the operation of the compressor 104. The controller 121 can process the signals from the pressure switch 120 and ensure a smoother start-up and shut-down of the compressor 104. The controller 121 can regulate the r.p.m. of the compressor 104 and control the amount of air that is forced towards the gas generating hollow fibre membrane module 112. In this manner, the compressor 104, which can be relatively expensive to operate, will only operate when it is deemed necessary to do so in order to maintain the desired level of pressure in the buffer tank 118 and the controller 121 will manage the smooth activation of the operation of the compressor 104 so that it is not started and stopped abruptly numerous times in close succession.

[0075] As can be seen the operation of the gas generation component 101 ensures that a preset minimum pressure level of nitrogen is held in the buffer tank 118 and is available for use in the liquid drink dispensing apparatus 100, whilst minimising the operating time of the compressor 104 which is advantageous from a running costs perspective and from an operational lifespan. This will also avoid the problems of liquid logging a hollow fibre membrane in the liquid dispensing component 103, as have been discussed in more detail hereinabove.

[0076] Turning now to the liquid dispensing component 103 of the liquid drink dispensing apparatus 100, a liquid drink, such as coffee, is dispensed from a dispensing tap 126. The liquid drink to be dispensed is stored in a container 128 which forms a liquid drink reservoir. The container 128 may be the typical bag-in-box type container as is used in the drinks industry, or could alternatively be a keg or other such drinks container. A pump 130 is used to force the liquid drink through the liquid dispensing component 103. The pump 130 may be preferably activated by the opening of the dispensing tap 126. A non-return valve 132 is provided downstream of the pump 130 and a gas infusing module 134 is provided after the non-return valve 132. In further preferred embodiments, the opening of the dispensing tap 130 may also be used to operate one or more of the compressor 104, the gas generating module 112, the gas infusing module 134, and/or the pump 130 to feed the liquid drink from the container 128 to the gas infusing module 134. In FIG. 3, the controller 121 sends an activation signal 302 to the pump 130. In this embodiment, the activation of the pump 130 can be controlled by the controller 121 so as to ensure operation of the compressor 104 for a preselected period of time prior to any activation of the pump 130.

[0077] In a preferred embodiment, the gas infusing module 134 is a gas infusing hollow fibre membrane module, as described in more detail with reference to FIG. 2.

[0078] The gas infusing hollow fibre membrane module 134 is shown in more detail in FIG. 2. The gas infusing hollow fibre membrane module 134 has a cylindrical casing 135 which forms a mixing chamber 140. Housed within the casing 135, of the gas infusing hollow fibre membrane module 134 are a plurality of hollow fibre tubes 136 extending between resin supports 137, 138 at opposite ends of the mixing chamber 135. Open inlet ends of the hollow fibre tubes 136, embedded in the support 137, receive nitrogen from a nitrogen inlet 139 of the mixing chamber 140 which is connected to the buffer tank 118. Opposite ends of the hollow fibre tubes 136, embedded in the support 138, are closed. Thus, nitrogen entering the mixing chamber 140 enters inside the hollow fibre tubes 136 (on the gas side of the hollow fibre tubes) and permeates outwardly through side walls of one or more of the plurality of hollow fibre tubes 136 into the mixing chamber 140 of the casing 135. A liquid inlet 142 and an aerated liquid outlet 143 are provided in a side wall of the casing 135 for circulation of liquid, in this case coffee, through the mixing chamber 140. As the coffee travels through the mixing chamber 140 between the liquid inlet 142 and the aerated liquid outlet 143, it surrounds the plurality of hollow fibre tubes 136 and is infused with nitrogen which permeates through one or more of the hollow fibre tubes 136 into the mixing chamber 140 of the gas infusing module 134.

[0079] The gas infusing hollow fibre membrane module 134 operates in a different manner to gas generating hollow fibre membrane module 112 discussed previously. The gas infusing hollow fibre membrane module 134 receives the pumped liquid from the container 128 and also intakes nitrogen (N.sub.2) from the buffer tank 118. Due to the fact that the buffer tank 118 holds nitrogen (N.sub.2) at pressure, the nitrogen will be forced into the gas infusing hollow fibre membrane module 134. The nitrogen (N.sub.2) from the buffer tank 118 is passed through the plurality of hollow fibre tubes 136, which on this occasion have a different permeability so as to allow the nitrogen (N.sub.2) to escape through the hollow fibre tubes 136 and into the mixing chamber 140 formed by the casing 135. The hollow fibre tubes 136 are closed ended so that all of the nitrogen (N.sub.2) from the buffer tank 118 which is passed into the hollow fibre tubes 136 will permeate through the hollow fibre tubes 136 and infuse the liquid drink held in the mixing chamber 140. The pressure of the nitrogen on the gas side of the skin of the plurality of hollow fibre tubes 136 is greater than the pressure of the liquid which surrounds the plurality of hollow fibre tubes 136 in the mixing chamber 135. This ensures that the gas infusing hollow fibre membrane module 134 will not become liquid logged. As discussed hereinbefore, the pressure switch 120, controller 121, compressor 104 and buffer tank 118 ensure that the pressure of the nitrogen delivered to the plurality of hollow fibre tubes 136 is above a minimum pressure level so that the nitrogen is at a pressure higher than the pressure of the liquid in the mixing chamber 140. As discussed with reference to FIG. 3, sequential operation of the compressor 104 and the pump 130 can also be used to ensure this, by running the compressor for a period of time before operating the pump 130. In this way, time is given for the compressor 104 to generate nitrogen which will be fed into the buffer tank 118 and increase the pressure level in the buffer tank 118 to an acceptable level before pumping the liquid from the container 128 into the mixing chamber 140 and increasing the pressure of the liquid in the mixing chamber 140.

[0080] Referring to FIGS. 1 and 2, the liquid drink is fed into the mixing chamber 140, forming part of the gas infusing hollow fibre membrane module 134, which casing 135 substantially surrounds and houses the plurality of hollow fibre tubes 136. As the nitrogen (N.sub.2) permeates out of one or more of the hollow fibre tubes 136, it becomes infused into the liquid drink which is surrounding the hollow fibre tubes 136 and has been fed by a pump 130 from a container 128 into the mixing chamber 140 of the gas infusing hollow fibre membrane module 134. It will be understood that when the liquid drink is not being dispensed, the liquid drink will be stagnant in the membrane module 134 and the liquid adjacent the hollow fibre tubes will become saturated with nitrogen as the liquid drink is stagnant. This saturation of the liquid drink which is stagnant and adjacent the hollow fibre tubes will cause the nitrogen (N.sub.2) to be ceased to be drawn out of and permeating through the hollow fibre tubes. When the dispensing tap 126 is opened and the liquid drink starts to flow again, the liquid drink which is saturated with nitrogen (N.sub.2) will flow away and out of the tap 126 and the liquid drink which replaces it will not have any, or very little, nitrogen (N.sub.2) and therefore the nitrogen (N.sub.2) will be drawn out and permeate through the hollow fibre tubes in the membrane module 134 again and continue to infuse the liquid drink.

[0081] This infusion process is seen to be advantageous as it is considered to be better than bubble diffusers given that the nitrogen is infused into the liquid drink at relatively low pressures and therefore the infused nitrogen will not immediately rise to the top of the liquid drink in the form of large bubbles and become expelled into the atmosphere. In this manner, the infused nitrogen remains in the liquid drink longer and the creamier, frothier properties of the nitrogen infused liquid drink can be enjoyed for a longer period of time as compared with standard bubble diffusers.

[0082] The nitrogen infused liquid drink is then dispensed out of the dispensing tap 126.

[0083] The opening of the dispensing tap 126 can be used to initiate the operation of one or more of the compressor 104, the gas generating module 112, the controller 121, the gas infusing module 134 and/or the pump 130. It is further envisaged that sequential operation of some or more of the components can be used to ensure a good quality drink is dispensed. For example, the compressor 104, the gas generating module 112, the controller 121 and/or the gas infusing module 134 may be operated for a period of time before the pump 130 is operated.

[0084] The level of infusion of a gas into a liquid will be determined by the length of the hollow fibre tubes 136 used in the gas-infusing membrane module 134. The flowrate of nitrogen is envisaged to be quite low. For example, a flow rate of about 0.1 litres per minute of nitrogen to about 2 litres per minute of coffee might be used, although it will be appreciated that the relative flow rates of gas and liquid may be varied depending on taste, and the selected gas and liquid used.

[0085] In order to generate different types of gases, the air intake 102 may be fed with different gaseous compounds, and the permeability of the hollow fibres in the gas generating hollow fibre membrane module 112 can be set so as to cause a separation of molecules as desired when a gaseous compound is passed through the hollow fibres of the gas generating hollow fibre membrane module 112.

[0086] In a similar fashion, if a gas different to nitrogen is to be infused into a liquid drink, or into a non-potable liquid in general, then the permeability of the hollow tube fibres 136 in the gas infusing hollow fibre membrane module 134 can be altered so as to ensure a sufficient level of infusion of a particular gas into a specific liquid.

[0087] It will be understood that the use and exact locations of the non-return valves 110, 116, 132, filters 106, regulators 108, purity needles 116, cooling coils and/or water separators and other such standard components, which have been described in the foregoing can be varied without departing from the scope of the present invention.

[0088] The terms comprise and include, and any variations thereof required for grammatical reasons, are to be considered as interchangeable and accorded the widest possible interpretation.

[0089] It will be understood that the components shown in any of the drawings are not necessarily drawn to scale, and, like parts shown in several drawings are designated the same reference numerals.

[0090] It will be further understood that features from any of the embodiments may be combined with alternative described embodiments, even if such a combination is not explicitly recited hereinbefore but would be understood to be technically feasible by the person skilled in the art.

[0091] The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.