GB2425165A

GB2425165A - Making frozen carbonated beverages(FCBs)

Info

Publication number: GB2425165A
Application number: GB0504752A
Authority: GB
Inventors: Johty Basant
Original assignee: IMI Vision Ltd
Current assignee: IMI Vision Ltd
Priority date: 2005-03-08
Filing date: 2005-03-08
Publication date: 2006-10-18
Also published as: GB0504752D0

Abstract

A method of and machine for making frozen carbonated beverages (FCB's) in which a beverage is simultaneously cooled and carbonated by expanding pressurised CO2 into the beverage in a carbonator chamber 5. The CO2 is introduced below the surface of the beverage via a nozzle 8 and CO2 that is not absorbed is recirculated in a circuit 7 including a compressor 1 for pressurising the CO2 to a pressure of between 60 and 120 bar and a condenser 4 for cooling the CO2 to a temperature of around ambient plus 5{C prior to returning to the carbonator chamber 5. Beverage in the carbonator chamber 5 is cooled by expansion of the CO2 and a temperature sensor 11 is provided to monitor the beverage temperature and activate a timer circuit when the beverage reaches a pre-determined temperature at which ice starts to form to control the ice concentration in the FCB.

Description

Method of and Machine for Making Beverages This invention relates to a

method of and a machine for making beverages, more particularly carbonated beverages containing an ice slush which are referred to in the art as "frozen carbonated beverages" (hereinafter "FCB5") and which are dispensed at about or below zero degrees Centigrade.

Currently there are a number of machines on the market for manufacturing FCBs. These use traditional refrigerants to indirectly cool the carbonated beverage sufficiently to produce the ice slush. To that end, these machines typically have the evaporator of the refrigeration system wrapped around the outer surface of a cylindrical pressure vessel containing the beverage.

Inside the pressure vessel, a scraper mechanism breaks ice off the inside surface of the externally cooled pressure vessel whereby an ice slush is produced in the beverage.

There are a number of problems associated with current machines.

Firstly, as they use indirect cooling, they are large and complex and require a great deal of test time during manufacture and regular servicing. Secondly, they are also very costly because of their complexity. Thirdly, they commonly use traditional refrigerants, such as but not limited to R-134a and R-404, which potentially present global warming problems.

It is an object of the present invention to provide a method of and a machine for making an FCB in which the above problems are overcome or mitigated.

According to a first aspect of the present invention there is provided a method of making an FCB in which pressurized carbon dioxide ("C02") is expanded into a beverage so as simultaneously to carbonate the beverage and cool it sufficiently that an ice slush is formed therein.

The CO2 is preferably pressurized in situ by a compressor, preferably to a pressure of between 60 and 120 bar.

The beverage may be any consumable liquid and may contain food solids.

According to a second aspect of the invention there is provided a machine for making an FCB, the machine comprising a closed vessel for receiving a beverage, a source of pressurized C02, means for expanding the pressurized CO2 into the beverage so as simultaneously to carbonate the beverage and cool it sufficiently that an ice slush is formed therein, and means for controlling the ice concentration in the FCB to a desired, preferably variable, value.

A preferred machine according to the present invention comprises a source of CO2 connected to the inlet of a compressor adapted to increase the pressure of said CO2 to between, preferably, 60 Bar and 120 Bar ("high pressure C02"), a valve to isolate the source of CO2 from the compressor, a condenser to reduce the temperature of the high pressure CO2 consequent on its being compressed by the compressor, an enclosed carbonator/refrigeration chamber adapted to be partially filled with the beverage, a nozzle having an outlet located within the chamber and through which the high pressure CO2 passes and expands thereby simultaneously cooling and carbonating the beverage, control means for controlling the ice concentration in the beverage, a return path connecting the space above the beverage to the compressor inlet, and means for enabling removal of the FCB from the chamber.

In a preferred arrangement, the condenser is of the tube in tube type and the coolant is water or other refrigerant (e.g. glycol).

The control means for controlling the ice concentration preferably comprises a temperature sensor positioned in a lower region of the carbonator chamber and a timing circuit which together operate as follows. When the machine starts up, the temperature of the beverage, as sensed by the temperature sensor, progressively drops to about zero degrees C at which point ice formation begins and the temperature of the beverage remains substantially constant. From that point, the ice content increases, more or less linearly in relation to time, therefore enabling the combination of temperature and time measurement to be used to control the desired ice concentration in the FCB. A preferred arrangement uses the change in gradient of the time/temperature curve to indicate the start of the time measurement used to control the desired ice content of the FCB.

In a preferred arrangement, the beverage is introduced into the carbonator chamber through an inlet into the chamber, via a valve, the beverage being pressurized to a higher pressure than the CO2 pressure prevailing in the carbonator chamber such that beverage can be continually added to the carbonator chamber without backflow. The FCB, once formed, is preferably dispensed by means of a tap or valve connected directly to the carbonator chamber.

Means for agitating the FCB may be provided in the carbonator chamber to improve the ice dispersion within the beverage.

In another preferred arrangement, the carbonator chamber is constructed of two separable parts and a carbonator bypass is included in the system. The system is run as described herein until the beverage has the required ice content, when the bypass switches to isolate the carbonator chamber from the high pressure CO2 so that the compressor can depressurize the carbonator chamber, storing the CO2 from the carbonator chamber in a buffer vessel. The bypass then switches to completely isolate the carbonator chamber from the rest of the system enabling it to be disconnected and the FCB dispensed. The carbonator chamber is then recharged with a fresh batch of beverage and is reconnected to the system (or alternatively is reconnected to the system and recharged with a fresh batch of beverage by an integrated means), after which the bypass switches to allow the reclaimed C02, stored in the buffer, to re- pressurize the system. The system is then restarted, any shortage of gas in the system ( because of CO2 absorbed by, and dispensed with, the beverage) is replaced from the source of CO2. In a similar arrangement a serving vessel (e.g. drinking glass or bowl) containing the beverage is placed in the carbonator chamber and the product is prepared in its serving vessel. Once prepared, the carbonator chamber is de-pressurized and the serving vessel complete with FCB is served to the customer. In an alternative arrangement, the carbonator is separable in such a way that the separable part contains the entire FCB at the end of the cycle. It is then detached and presented to the customer complete with FCB - thereby serving the dual purpose of carbonator chamber and serving vessel. A new separable carbonator part containing beverage is then attached to the machine and the process resumed. Preferably, the machine consists of one compressor and CO2 circuit but two or more carbonator chambers independently switchable in and out of communication with the CO2 circuit enabling one FCB to be prepared whilst others are being dispensed.

It is important that machines used for producing product for human consumption are sterile and free from microbial growth. This is often achieved by flushing the system through with cleaning and sterilizing products. In a preferred machine of the invention there is provided in the aforesaid return path from the carbonator chamber to the compressor and downstream of the carbonator chamber bypass, if included, a means of removing moisture (which is necessary for microbial growth) from the CO2. In addition, removal of moisture from the CO2 protects the compressor and enhances its life. Preferably the means of removing the moisture incorporates a regenerative desiccant agent which is preferably regeneratable by the application of heat. Such devices are known to those skilled in the art.

When the invention described herein is used to provide FCBs of differing flavours, there is the possibility of cross contamination between products by means of aromas carried in the CO2. In a preferred arrangement, there is provided a means of absorbing aroma from the CO2 such as, but not limited to, a filter element containing activated carbon. Such filters generally have a finite life so need to be easily replaceable. Ideally there is a control and time algorithm within the control electronics of the machine which identifies when the filter has been changed and after a certain amount of time (absolute or operational) has lapsed signals that the filter should be changed.

The present invention alleviates most of the main problems associated with current FCB machines. Use of direct cooling in which the CO2 is in direct contact with the beverage enables a much simplified system, reducing parts, test requirements and maintenance requirements. In addition, the use of CO2 which has a low global warming potential, as a refrigerant makes this invention more environmentally acceptable in the long term.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagram of a machine of the invention; Figure 2 is a diagram of a carbonator/refrigeration chamber of a machine of the invention incorporating a means of agitating the FCB; Figure 3 is a diagram of a machine of the invention in which the carbonator chamber is opened to remove the FCB; Figure 4 is a diagram showing the relation between temperature, time and ice content of an FCB made using the method/machine of the invention.

Referring to Figure 1, a diagram of a machine for producing an FCB is shown in which the inlet of a compressor I is supplied with CO2 from a source of CO2 2 by means of a valve 3. The CO2 exits the compressor I at a pressure of between 60 and 120 bar and at a temperature of around 180 C. It then passes through a condenser 4 which reduces the temperature of the CO2 to around ambient plus 5 C before it enters a carbonator 5, containing a beverage 6, via a conduit 7. The conduit 7 terminates in a nozzle 8 which is immersed in the beverage 6. The CO2 exits the nozzle 8 into the carbonator 5 and expands as the pressure drops, absorbing energy from the beverage 6 thus simultaneously reducing its temperature and carbonating it. An outlet in the carbonator 5 above the level of the beverage 6 allows expanded CO2 not absorbed into the beverage to be drawn back into the inlet of the compressor 1. A conduit 9, one end of which is immersed in the beverage 6, leads from the carbonator 5 to a valve 10, the opening of which enables the beverage 6 to be dispensed. A temperature sensor 11 is located on the carbonator 5 below the level of the beverage 6 which sends a signal to a controller (not shown) incorporating a timer which is used to control the flow of CO2 to produce an FCB having the required ice content.

Referring to Figure 2, a diagram of an alternative carbonator is shown, which could replace directly the carbonator shown in Figure 1, comprising the carbonator 5 containing the beverage 6 and a conduit 7 supplying high pressure CO2 terminating in a nozzle 8 submerged in the beverage 6. A conduit 12 supplies beverage 6 to the carbonator 5 and a further conduit 9 allows the FCB to be dispensed by means of a valve 10. Above the level of the beverage an outlet leads to a conduit 14 for returning the expanded CO2 to the compressor (not shown). In the carbonator 5 is provided a means of agitating the FCB comprising a series of blades 15 mounted on a spindle 13 which can be rotated to provide agitation, ensuring homogeneous ice distribution in the FCB.

Referring to Figure 3, in which features similar to those in Figure 1 bear the same reference numerals, a diagram of a machine for producing an FCB in which the carbonator 5 is opened to dispense the product is shown. The machine comprises a compressor 1 which is supplied with CO2 from a source of CO2 2 by means of a valve 3.

The CO2 exits the compressor I at a pressure of between 60 and 120 bar and at a temperature of around 180 C. It then passes through a condenser 4 which reduces the temperature of the CO2 to around ambient plus 5 C before it enters the carbonator 5 containing the beverage 6 via a conduit 7. The conduit 7 terminates in a nozzle 8 which is located in the beverage 6.The CO2 exits the nozzle 8 into the carbonator and expands as the pressure drops, absorbing energy from the beverage 6 thus simultaneously reducing the temperature and carbonating the beverage. An outlet in the carbonator 5 above the level of the beverage 6 allows expanded CO2 not absorbed into the beverage to be drawn back into the inlet of the compressor 1.

Once the product is ready to be dispensed it is necessary to reduce the pressure in the carbonator to ambient to enable it to be safely opened so that the FCB inside can be dispensed. A valve 16 in conduit 7 is switched into its closed position isolating the carbonator from the high pressure CO2 and another valve 17, previously closed, opens to allow the CO2 to pass through the non return valve 18 into the buffer vessel 19. The compressor I then runs until the pressure in the carbonator 5, measured by pressure sensing means 20, has been reduced to ambient. Valve 21 and valve 17 are then shut completely isolating the carbonator 5 from the pressurized part of the system and vent valve 22 is opened to ensure pressure equality between the carbonator and the external environment. The lower part of the carbonator is removed at coupling 23, enabling the FCB to be extracted. The separable part of the carbonator is then recharged with the beverage and reconnected to enable the next batch of beverage to be carbonated and frozen. Valve 22 is then closed, after which valves 16 and 24 are opened to re-pressurize the system and then the system is restarted, If there is a shortfall of CO2 in the system, as a result of CO2 absorbed in the dispensed product and any vented from valve 22, it is topped up from source 2 via valve 3.

Check valve 25 prevents pressure from the CO2 source 2 feeding back into the carbonator 5 in event of a pressure imbalance in the system.

Referring to Figure 4, a characteristic plot of temperature, time and ice formation is shown in which the horizontal axis shows time, the left vertical axis shows temperature and the right vertical axis shows ice content. Point A is the point at which ice formation begins and the point from which further ice formation is proportional to time. The slope of the temperature/time change is monitored and once it reaches a critical value (the ice formation point), a counter is started.

With this method it is possible to produce FCBs to a repeatable quality standard.

Claims

1. A method of making an FCB in which pressurized carbon dioxide (C021') is expanded into a beverage so as simultaneously to carbonate the beverage and cool it sufficiently that an ice slush is formed therein.

2. A method according to claim I wherein the CO2 is pressurized to a pressure of between 60 and 120 bar and is cooled prior to expanding into the beverage.

3. A method according to claim I or claim 2 including the step of controlling the ice concentration in the ice slush in response to the beverage temperature and the duration of CO2 addition to the beverage.

4. A method according to any preceding claim wherein the beverage is carbonated and cooled in a chamber from which ice slush is removed via a tap or valve. S... S...

5. A method according to claim 4 in which beverage is added to ** the chamber at a pressure higher than the CO2 pressure in the chamber.

6. A method according to claim 4 or claim 5 in which a CO2 circuit is provided whereby CO2 that is not absorbed into the beverage is recirculated and returned to the chamber.

7. A method according to claim 6 in which the CO2 circuit includes a CO2 by-pass for isolating the chamber from the circuit for removal of ice slush from the chamber.

8. A method according to claim 6 or claim 7 wherein two or more chambers are provided that are independently switchable into and out of communication with the CO2 circuit.

9. A method according to any of claims 6 to 8 including the step of removing moisture and/or aroma from 002 removed from the chamber.

10. A method of making an FCB substantially as hereinbefore described with reference to the accompanying drawings.

11. A machine for making an FCB, the machine comprising a closed vessel for receiving a beverage, a source of pressurized 002, means for expanding the pressurized 002 into the beverage so as simultaneously to carbonate the beverage and cool it sufficiently that an ice slush is formed therein, and means for controlling the ice concentration in the FCB to a desired value. * * * S S *5 **

12. A machine according to claim 11 wherein the addition of 002 is S...

controlled to produce a desired ice concentration.

13. A machine according to claim 12 including a temperature sensor for monitoring the beverage temperature in the vessel and a timer circuit for controlling the carbonation and cooling cycle to produce the desired ice concentration in the beverage.

14. A machine according to any of claims 11 to 13 including a 002 circuit for supplying pressurised 002 to the vessel and re-circulating CO2 that is not absorbed.

15. A machine according to claim 14 wherein the CO2 circuit comprises a compressor adapted to increase the pressure of the 002 to produce high pressure C02, a valve to isolate the source of 002 from the compressor, a condenser to reduce the temperature of the high pressure CO2 consequent on its being compressed by the compressor, a nozzle having an outlet located within the closed vessel containing the beverage and through which the high pressure CO2 passes and expands thereby simultaneously cooling and carbonating the beverage, and a return path connecting a space above the beverage to the compressor inlet.

16. A machine according to claim 14 or claim 15 wherein the 002 circuit includes a 002 by-pass for isolating the vessel from the pressurised source of CO2

17. A machine according to any of claims 14 to 16 wherein the * CO2 circuit is connected to two or more closed vessels that independently switchable in and out of communication with the CO2 circuit. * * * S S S.

18. A machine according to any of claims 14 to 17 wherein the CO2 circuit is provided with a means of removing moisture and/or a means of removing aroma from re-circulated CO2

19. A machine according to any of claims 11 to 18 wherein the vessel has an inlet for adding beverage into the vessel, via a valve, and an outlet for dispensing FCB, once formed, via a tap or valve connected directly to the vessel.

20. A machine according to any of claims 11 to 19 wherein means is provided for agitating the FCB in the vessel to improve the ice dispersion within the beverage.

21. A machine making an FCB substantially as hereinbefore described with reference to the accompanying drawings. o. * * * l's. *5 * * p I

I * * i p S p.,.

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