Carbonation duct for blending a gas and a beverage and carbonation process

Carbonation duct (1) for blending a gas and a beverage. The carbonation duct (1) includes a tubular structure (12) surrounding a compression structure (13), the compression structure (13) longitudinally positioned inside the tubular structure (12) and setting a pathway (14) for the flowing of the beverage along the carbonation duct (1). The compression structure (13) includes external diameters (P,C,G) sequentially defining a convergence path (8), a mixture path (19) and a slowdown path (20) along the carbonation duct (1), wherein, in the convergence path (8), the carbonation duct (1) includes a gas entry portion (9) for gas injection in the pathway (14), and the tubular structure (12) defines a turbilionating projection (10) establishing a carbonation duct (1) mixture diameter (F).

Present invention refers to a carbonation duct and a carbonation process. Specifically, present invention is related to a carbonation duct and process which increases the gas solubility in a beverage.

In the carbonation processes and ducts known in the art is inevitable to keep the pressure in the carbonator tank stable in order to maintain the CO2volume constant in the beverage.

This happens due to the fact that in the processes and ducts known in the art, the variables (i) beverage temperature, (ii) beverage flow rate, (iii) CO2flow rate in the carbonation duct gas entry portion and (iv) carbonation duct structural configuration are all related to each other in order to achieve an uniform value for the CO2volume in the beverage.

In the carbonation process proposed in the present invention, while the beverage enters the carbonator tank and the pressure inside the tank starts to increase (considering that the valve in the tank output is closed), such increment of pressure is controlled by managing (controlledly closing) the CO2flow rate in the carbonation duct by controlling a modulating valve percentage of opening.

On the other hand, in the proposed process if the pressure in the tank decreases, such drop of pressure will be controlled by increasing the CO2flow rate in the carbonator tank.

In other words, if the pressure in the tank increases, the modulating valve is closed (CO2flow rate in the venturi is reduced). In the conventional process known in the state of the art, when the pressure in the tank increases, the CO2is expelled (vented) to the atmosphere.

In the present process, no CO2is expelled, all pressure variations in the tank are instantly compensated by managing the CO2flow rate in the carbonation duct and in the carbonator tank.

Additionally, the carbonation duct proposed herewith makes use of a turbilionating projection in the area adjacent to the gas entry portion, providing an efficient turbulence between the beverage and the CO2.

The ducts known in the art make use of high pressure pumps to create a high pressure area for the CO2and beverage mixture (blending). Further, these ducts provide a carbonation process which demands several steps to achieve a desired CO2volume which results in a very stir beverage (agitated), turning the beverage filling process non efficient.

Further, the carbonation ducts known in the art reduce the area of the duct like a bottle neck. In present invention, the area of the duct is reduced by adding a stainless solid body in the duct which increases the contact area between the beverage and the gas.

If the beverage flow rate is kept constant and the area of the carbonation duct is reduced, the beverage velocity increases as it passes through the reduced area. Consequently, if the kinetic energy increases, the energy determined by the pressure value reduces considerably.

This drop of pressure generates vacuum in the reduced area of the carbonation duct proposed in the present invention. This principle is used in the proposed carbonation duct to introduce CO2in the duct.

Even though this drop of pressure favors the mixture between the gas and the beverage, to improve such mixture and ensure a high efficiency in the process, the carbonation duct proposed herewith further uses a turbilionating projection in the reduced area of the duct.

One of the main advantages of the proposed carbonation duct lies on the fact that the pressure difference between the carbonation duct entry and exit is in the range of 10% and 20%. This means that, a pressure in the duct entry of 2,0 kg/cm2will decrease to just 1,6 kg/cm2(maximum decrement) to 1,8 kg/cm2(minimum decrement) in the duct exit portion. In the conventional ducts known in the state of art, this pressure difference can reach 50%.

Further, the efficiency of the proposed carbonation duct does not require the use of a homogenizing processes after the carbonation, as required in some carbonation processes and systems known in the state of the art.

Another advantage of the carbonation duct is that it allows an optimal CO2dissolution in the water, minimizing the CO2consumption.

Additionally, the carbonation duct as proposed generates a very low impact over the gas kinetic energy soluble in the beverage. Consequently, the beverage foaming at the time of filling is minimized.

Another advantage of the carbonation duct proposed in the present invention is that the use of a flow meter is not required in order to control the gas flow rate in the carbonation process, even so the carbonation process efficiency is achieved.

Further, the proposed carbonation process makes use of a carbonator tank that does not comprise any rings, plates, or any other equipment inside of it. The claimed process only uses a carbonator tank to reach the gas solubilization.

Additionally, in the claimed process there is no venting of gas, since the gas that is not dissolved in the beverage is recovered to be used again in the process.

The carbonation duct further uses the beverage velocity as it enters the duct to generate the necessary vacuum to provide the beverage carbonating, so, the gas pressure in the gas entry portion is relatively low.

The claimed process further provides the possibility of recirculating the beverage to increase or reduce the gas volume.

Additionally, with the process proposed herewith, if the beverage temperature increases, the compensated pressure (the required pressure to establish a desired volume of gas in the beverage) is increased, and, in order to keep constant the volume of CO2solubilized in the beverage, CO2will be added in the tank (increasing the tank's pressure).

Alternatively, if the beverage temperature decreases, the value of the compensated pressure is also reduced and, in order to keep a desired amount of gas in the beverage, the CO2flow rate in the carbonation duct will be reduced.

With the above mentioned compensation, the process will equalize (making equal) the value of the compensated pressure with the carbonator tank's internal pressure.

In the conventional processes known in the state of art, the compensation due beverage temperature variations is done by expelling CO2to the atmosphere, which does not occur in the proposed process, wherein no CO2is expelled.

OBJECTIVES OF THE INVENTION

Present invention first objective is to provide a carbonation duct which increases the gas solubility in a beverage.

A second objective is to provide a carbonation process which reduces the gas losses during the steps of the process.

A third objective is to provide a structural configuration for the gas entry portion and for the beverage entry portion which increases the mixture between the beverage and gas.

A further objective is to provide a turbilionating projection in the carbonation duct, the turbilionating projection comprising a whirl wall to achieve increased gas dissolvability in the beverage when compared to the prior art solutions.

Present invention's further objective is to provide a carbonation duct with three well defined portions.

An additional objective is to provide a carbonation process which compensates the variation of pressure in the carbonator tank by controlledly managing the CO2flow rate that enters the carbonation duct and the CO2flow rate that enters the carbonator tank.

An additional objective is to provide a carbonation process which compensates the variations of the beverage temperature by controlledly managing the CO2flow rate that enters the carbonation duct and the CO2flow rate that enters the carbonator tank.

Further, another objective is to provide a carbonation process that does not expel CO2to the atmosphere in order to compensate variations of pressure in the carbonator tank and further variations of the beverage temperature.

An additional objective is to provide a carbonation process and a carbonation duct that keeps constant the volume of CO2solubilized in the beverage by managing the CO2flow rate that is added to the carbonator tank and to the carbonation duct.

A further objective is to provide a carbonation process that reintroduces the carbonated beverage in the carbonator tank in order to increase or decrease the CO2volume in the beverage.

BRIEF DESCRIPTION OF THE INVENTION

Present invention objectives are reached with a carbonation duct for blending a gas and a beverage, the carbonation duct comprising: a tubular structure surrounding a compression structure, the compression structure longitudinally positioned inside the tubular structure and setting a pathway for the flowing of the beverage along the carbonation duct.

The compression structure comprises external diameters sequentially defining a convergence path, a mixture path and a slowdown path along the carbonation duct, wherein, in the convergence path, the carbonation duct comprises a gas entry portion for gas injection in the pathway. The tubular structure defines a turbilionating projection establishing a carbonation duct mixture diameter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a block diagram representing the carbonation duct1as proposed in present invention.

The carbonation duct1as proposed is used to provide gas solubility in a beverage. By beverage, it can be understood any kind of drinkable liquid, and the gas used in the carbonation duct is, preferably carbon dioxide (CO2). Still in reference toFIG. 1, it can be noted that the carbonation duct1is connected to a carbonator tank21.

The length of the carbonation duct1should be determined according to its diameter, which depends from the amount (flow rate) of beverage that needs to be carbonated. In other words, the beverage flow rate determines the carbonation duct1diameter, which determines the carbonation duct length. The carbonation duct1diameter will be hereafter described as flowability diameter K.

The table below makes reference toFIG. 2and represents a relation between the length of the carbonation duct1, the flowability diameter K and the maximum beverage flow rate that needs to be carbonated:

In reference to the carbonation duct1structural configuration,FIG. 2is a cross sectional view of a preferred embodiment of the duct1. For a better understanding, the proposed duct1will be segmented in three different well defined main portions, a convergence path8, a mixture path19and a slowdown path17.

As can be seen fromFIG. 2, the carbonation duct1as proposed in present invention comprises a tubular structure12(a hollow cylinder or any other suitable cross section) associated to a compression structure13, such association sets a pathway14for the flowing of a solution, that is, beverage with gas (mixture path19and slowdown path17) or without gas (convergence path8).FIGS. 3 and 4respectively illustrate the tubular structure12and the compression structure13.

As can be seen especially fromFIG. 2, the compression structure13is surrounded by the tubular structure12and is longitudinally positioned inside the structure12. Further, the length L1of the convergence path8is equivalent to the tubular structure internal diameter K (flowability diameter K), as can be better seen fromFIG. 2.

The carbonation duct1further comprises a beverage entry portion5disposed in the convergence path8. Such beverage entry portion5may be best seen fromFIG. 2. Closer to the mixture path19, the area of the pathway14of the entry portion5decreases, configuring a funnel shaped passage for the flowing of the beverage.

To achieve that configuration, the carbonation duct1comprises a turbilionating projection10from the tubular structure12in direction of the compression structure13, such protuberance being configured as a planar ramp that protrudes inwardly from the tubular structure12.

The turbilionating projection10further comprises a whirl wall27configured to potentiate the gas and beverage mixture. In this preferred embodiment of the carbonation duct1, the whirl wall is configured as a concave surface and has a preferred whirl wall depth H of 1,3 mm. Further the whirl wall radius R1is preferably 4.5 mm. The whirl wall27can be better seen fromFIGS. 5 and 6.

The whirl wall27is configured to generate a turbulence effect in the mixture path19and specifically in the area adjacent to the gas entry portion9. Such turbulence allows the increment of the gas dissolvability (capacity of dissolution) in the beverage (over 7%), specifically, such increment occurs due the beverage acceleration and atomization as it contacts the gas.

Further, the proposed whirl wall radius R1reduces the pressure drop in the mixture path19(specifically in the area adjacent to the gas entry portion9), since the contact area of the beverage and the compression structure13in the region of the narrowest passage of the pathway is minimum.

Additionally, the whirl wall radius R1allows the gas flow towards the beverage flux, as indicated inFIG. 7, so, avoiding the perpendicular gas flow entry and thus achieving the desired efficiency levels discussed above.

Back in reference toFIG. 5, it represents a cross sectional view of the convergence path8illustrating the elements mentioned above. The beverage entry portion5can be understood as being the area between the tubular structure12and the compression structure13that allows the flowing of a beverage.

For an appropriate entry of the beverage in the carbonation duct1, a deviation angle A is set in the compression structure13, as can be seen according toFIG. 5.

The deviation angle is measured from an internal axis (X) until the surface of the compression structure that establishes the pathway (14), as can be seen fromFIG. 5.

The deviation angle A is not dependent from the beverage flow rate, and, in this preferred embodiment of the carbonation duct1, the deviation angle A assumes a preferred value of approximately 8°. Obviously, such value represents just a preferred value, as, other magnitude for the deviation angle can be used, for example, a range from 5° to 10° is acceptable.

Still in reference to the convergence path8, it comprises a maximum preferred diameter P that is 0,85 the value of the flowability diameter K (P=K*0,85)

FromFIG. 5, and as already mentioned, it can be seen that the convergence path8comprises a turbilionating projection10from the tubular12to the compression structure13of the carbonation duct 1.

The turbilionating projection10defines a convergence angle B for the flowing of the beverage, specially, the convergence angle B is measured from the internal axis X of the compression structure13until the surface of the turbilionating projection10which defines the pathway14, as can be seen fromFIG. 5.

The angle B establishes a balance between the beverage flow speed and the drop of the beverage pressure as it flows in the area bounded by the convergence angle B.

In this preferred embodiment of the carbonation duct1, the convergence angle B assumes a value of 13°. Like the deviation angle A, this is just a preferred value for the convergence angle B, and, a range from 8° to 15° would be acceptable.

The turbilionating projection10establishes a carbonation duct mixture diameter F, as can be better seen fromFIG. 2. For an appropriate configuration of the projection10, the mixture diameter F should be 16 millimeters (mm) smaller than the tubular structure flowability diameter K, a tolerance of 0,1 mm can be admitted.

That 16 mm difference from the tubular structure diameter K allows a correct configuration for the convergence angle B, since by increasing the area of the pathway14, a beverage turbulence is achieved.

That turbulence occurs as the beverage exits the area bounded by the turbilionating projection10and enters the mixture path19. Such turbulence allows a high speed mixture between the beverage and the gas due the expansion generated in the beverage.

In the mixture path19, the compression structure's13diameter should depend directly from the mixture diameter F, since the objective of the mixture path19is to set a determined drop in the beverage pressure following the Venturi concepts. InFIG. 2, the internal structure's diameter is represented by a mixture path diameter C.

Preferably, the ratio between the diameters C and F (C/F) should be between 0.65 and 0.75 (tolerance of 0,1 mm). In this preferably range, the carbonation process shows high efficiency, as for values greater than 0.75, the pressure drop would be considerably high.

For smaller values than 0.65, the beverage flow rate in the convergence path8, and specifically in the turbilionating projection10, would not be sufficient to generate a satisfactory level of vacuum (or negative pressure).

The ratio between the diameters C and F has the objective of increasing the beverage flow rate speed as it passes by the turbilionating projection10(neck of the carbonation duct), further, the proposed ratio sets an optimal relation between the beverage drop of pressure as it flows in the area of the turbilionating projection10and the level of vacuum (or negative pressure) generated.

The length L2of the mixture path19should be such as to retain the beverage acceleration due to a predetermined period of time (retention time), establishing the proper gas volume in the beverage. In a preferred embodiment, the retention time is about 40 milliseconds (ms).

Knowing the retention time of 40 ms and the beverage flow rate, the length L2of the mixture path19can be determined in relation to the pathway14area, as follows:

In reference toFIG. 2, in the mixture path19, the area of the pathway14is kept constant and is determined by:
Area=DiameterK−DiameterC;
Area=π*τ2

It is valid to remember that the flowability diameter K depends to the beverage flow rate and to the carbonation duct1length.

Still relating toFIG. 2, it can be seen that the carbonation duct1further comprises a slowdown path17adjacent to the mixture path19. The border portion between the slowdown path17and mixture path19is defined by a junction axis18.

Starting from the junction axis18, and along the slowdown path17, the area of the pathway14gradually increases. The purpose of this increment is to achieve a progressive slowdown of the beverage flowing in the carbonation duct1.

An instantaneous slowdown would increase the kinetic energy in the gas soluble in the beverage, resulting in an abrupt gas discharge. The structural configuration of the compression structure13and the tubular structure12establishes a divergence angle D, which assumes a maximum value of 9°. A minimum value of 4,5° would be accepted, thus any angle within that range can be used.

FIG. 8represents a perspective cross sectional view of the gas entry portion9of the carbonation duct1proposed in the present invention. It can be seen that the gas entry portion9is disposed adjacent to the pathway14, specifically, in a region of the carbonation duct1comprising the smallest area of the pathway14.

In reference to the gas entry portion9, the gas flow rate in the portion9should allow the gas flowing rate requested by the system. Specifically regarding the carbonation duct1, the pressure drop in the duct1should not affect the gas flow rate.

As an example, considering 0,7 MPa (7 bar) of gas pressure at the gas entry portion9, the maximum admissible pressure drop should be around 1.5% of the “pressure of project”, thus the maximum admissible pressure drop is 0,01 MPa (0.1 Bar).

Knowing the maximum admissible pressure drop, the minimum gas entry portion area can be determined in reference to the following elements:

Maximum beverage flow rate of the carbonation duct1and of the carbonation system: QMAX

Maximum volume of gas in a beverage: VCO2MAX. It represents the maximum volume of gas that should be diluted in the beverage and a relation between the carbonated beverage volume and the gas volume dissolved at atmospheric pressure. For a bottle of 100cm3in 3 Volumes of CO2, 300 cm3of CO2should be dissolved at atmospheric pressure.

Maximum gas flow rate: QGMAX. It represents the maximum gas consumption rate, depending on the maximum gas volume that should be dissolved in the beverage according to the maximum beverage flow rate QMAX, in other words, QGMAX=VCO2MAX*QMAX.

Maximum pressure of the carbonation duct1: PMAX. To increase the amount of gas dissolved in the beverage, it is necessary to increase the gas pressure in the gas entry portion9, since, when the pressure is increased, the gas volume that flows in the entry portion9is also increased.

The internal diameter of the gas entry portion9can be achieved using the Darcy-Weisbach expression:

As the “pressure of project” is 0,7MPa (7 bar), the value of Δpis 0,01 MPa (0.1 Bar) (1.5% of 7 Bar).VCO2MAXcan be established as 6 (relation between the carbonated beverage volume and the gas volume dissolved at atmospheric pressure).

The maximum beverage flow rate (QMAX) of the carbonation duct1is determined considering a 101,6 mm (4 inch) duct, through conducted experiments, a QMAXof 0.75 m3/min was reached. So, a maximum gas flow rate (QGMAX) of 4.5 m3/min is achieved. Further, a length of 0.3 meters is used (tube that connects the tank21to the duct1, indicated with the reference39inFIG. 1).

By the Darcy-Weisbach expression, a minimum diameter of 14.2 mm is achieved, consequently, an area of 158.28 mm2is determined.

Knowing the area, the height of the gas entry portion9can be determined as below:
Height=Area/Perimeter, wherein

The gas entry portion9height is the dimension between the compression structure13and the closest point of the turbilionating projection10to the compression structure13(the entry of CO2in the duct1occurs in an annular way).

Having described a preferred embodiment for the carbonation duct1, the steps of the carbonation process which increases the gas solubility in the beverage and reduces the gas losses will be described.

For a better understanding of the carbonation process proposed in present invention,FIG. 9will be used as reference. In such figure, the main components are the carbonation duct1as described before, the carbonator tank21, an evaporator30and a plurality of valves31,32,33,34,35and37which their operation will be better described in sequence.

Further, the proposed carbonation process will refer to two main terms, a compensated pressure PCand a carbonator tank pressure PR.

The compensated pressure PCis the desired pressure for achieving a desired gas volume in the beverage. Such compensated pressure PCis determined by the user responsible of performing the carbonation process.

The carbonator tank pressure PRis the real pressure measured in the carbonator tank21.

Basically, the carbonation process proposed herewith compensates the carbonator tank pressure PRvariations and the compensated pressure PCvariations by just controlling the operation (percentage of opening) of the modulating valve31(therefore controlling the CO2flow rate that enters in the carbonation duct1) and by controlling the CO2flow rate that enters the carbonator tank21.

So, in the proposed process, and differently from the prior art teachings, no CO2is expelled to the atmosphere.

Further, in the proposed process, and due the controlling of the CO2flow rate that enters in the carbonation duct1and in the carbonator tank21, the process aims to always equalize (make equal) the value of the compensated pressure PCwith the value of the carbonator tank pressure PR.

Regarding the compensated pressure PC, the only factor that can affect it during the process is the beverage temperature:

Compensation Due Temperature Variations

The beverage temperature should be controlled before its entry in the carbonation system. As can be seen fromFIG. 9, an evaporator30is used to manage the beverage temperature.

The preferred beverage temperature in the entry of the carbonation duct1is 4° C. This value provides a greater efficiency in the carbonation process.

However, if for any reason the beverage temperature varies (increase or decrease) before entering the carbonation duct1, the proposed process automatically compensates such variation, as will be described below.

Considering a scenario wherein the beverage temperature is 4° C. and the carbonation process is normally being performed, with the value of the compensated pressure PCequal to the value of the carbonator tank pressure PR.

If the beverage temperature increases during the carbonation process, such increment will also increase the value of the compensated pressure PCbut the value of the carbonator tank pressure PRwill not be affected. Consequently, in this scenario, PCwould be greater than PR.

So, in order to compensate such variation, the proposed process automatically adds CO2in the carbonator tank21until both pressures are equalized, in other words, the CO2control valve32is opened and the carbonator tank pressure PRwill be equal to the compensated pressure PC. The CO2control valve will be opened proportionally according to the increment in the beverage temperature.

It is important to mention that in an optimal scenario, that is, being the carbonator tank pressure PRequalized with the compensated pressure PC(PR=PC=4 kg/cm2), the CO2control valve should be closed. By adding CO2in the tank21, the value of the carbonator tank pressure PRwill increase and consequently equalized (being equal) to the value of the compensated pressure PC.

If, for any reason, the beverage temperature decreases, such decrement will also decrease the value of the compensated pressure PC, but the carbonator tank pressure PRwill not be affected.

In order to compensate such variation, the CO2flow rate that is added in the carbonation duct1should be decreased, consequently, the modulating valve31should be closed (percentage of opening is reduced).

The table below shows preferred values for the modulating valve percentage of opening considering a decrement in the beverage temperature and consequently a decrement in the value of the compensated pressure PC.

Values for the compensatedpressure PC(Kg/cm2)(considering a pressure PRin thetank of 4 kg/cm2)Modulating valve % of opening4.0803.9763.8723.7703.665

With the reduction of the modulating valve31percentage of opening, the pressure in the tank PRwill be equalized with the compensated pressure PC, setting the process in the desired scenario.

The beverage flow rate in the carbonation duct1entry portion (beverage entry portion5) should be constant (stable), since the carbonation duct1structural configuration is dimensioned according to the desired beverage bottling, and, the carbonation duct1diameter is kept constant (diameter C).

If small changes in the beverage flow rate occur in the beverage entry portion5, the vacuum in the carbonation duct1would decrease or increase proportionally. Such variation in the vacuum allows a small compensation in the blending of beverage and gas, since the CO2flow rate would increase or decrease in the carbonation duct1.

If the beverage flow rate decreases considerably, the beverage in the carbonation duct1would not achieve turbulence as it flows by the turbilionating projection10. Further, with an undesired beverage flow rate, there would not be vacuum in the gas entry portion9and consequently the carbonation process would not occur as it should.

To start the process, after the value of the compensated pressure PChas been set, it necessary to add the desired amount of CO2in the carbonator tank21, for this, the CO2control valve32should be opened and then beverage should be added in the tank21.

As mentioned before, in the proposed process, the compensated pressure PCshould always be equal to the pressure measured in the tank21(carbonator tank pressure PR).

It is important to mention that the pressure in the tank21(carbonator tank pressure PR) is preferably measured at the upper portion of the tank21, indicated with the reference33inFIG. 9. The pressure PRcan be shown in a control panel38disposed near the system disclosed inFIG. 9. Any method known in the art of measuring the pressure of a compartment could be used.

In order to add beverage in the tank21, the beverage control valve34should be opened. As the beverage passes through the evaporator30, its temperature decreases and reaches 4° C. (preferred to mperature).

As the beverage control valve34is opened, the Venturi valve35and the modulating valve31should be kept 80% opened to control the gas flow rate in the carbonation duct1. Further, as the beverage enters the carbonator tank21, it solubilizes CO2by the carbonation duct1.

To ensure that just CO2will be added in the carbonator tank21, the Venturi valve35is placed at 90% of the height of the tank21. If such valve35was placed above this level (or even outside the tank21), there would be the possibility of adding air in the carbonator tank1, since air is lighter than CO2, it is disposed in the upper portion of the carbonator tank21.

Compensation Due Carbonator Tank Pressure PRVariations

The entry of beverage in the tank21consequently increases the carbonator tank pressure PR, making it greater than the compensated pressure PC.

To avoid that such increment affect the CO2flow rate in the duct1, and further to equalize the pressure in the tank PRwith the compensated pressure PC, the modulating valve31is gradually closed following an expression related to CO2oscillations at distinct pressures.

Table below represents preferred values for the carbonator tank pressure PRand the corresponding preferred percentage of the modulate valve31opening (illustrative values) considering a compensated pressure of 4 kg/cm2.

As can be seen, and as already mentioned, as the real pressure in the tank (PR) increases, the modulating valve31percentage of opening decreases (valve is closed):

By closing the modulating valve31, the carbonator tank pressure PRwould be equalized with the compensated pressure PC.

As the process solubilizes the CO2in the beverage, the carbonator tank pressure PRmay start to decrease, while the compensated pressure PCwill not be affected.

In order to compensate such pressure drop, the CO2control valve32may be opened to avoid that the tank21reaches it minimum allowable pressure and also to manage the CO2flow rate in the duct1. In order words, the CO2flow rate that is added in the tank21should be increased.

As already mentioned, being the compensated pressure PCequalized with the carbonator tank pressure PR, the CO2control valve32should be closed. Consequently, if the pressure inside the tank PRdecreases, the CO2control valve32will be opened proportionally according to the decrement in the tank PRpressure.

The addition of CO2in the tank21would increase the carbonator tank pressure PRand consequently equalize the pressure PRwith the compensated pressure PC. When both pressures are equalized the CO2control valve32will be closed again

If any abrupt pressure drop in the value of the carbonator tank pressure PRoccurs, of if the pressure PRreaches a value 10% (in this case 3,6 Kg/cm2) lower the value of the compensated pressure PC, the process may also increase the percentage of opening of the modulating valve31in order to faster equalize it with the compensated pressure PC.

For values lesser than 3,6 Kg/cm2(for pressure drops greater than 10%), the carbonation process should be immediately interrupted. In this sense, when the pressure in the carbonator tank PRconsiderably or abruptly drops, the modulating valve31works as a support for the CO2control valve.

So, in optimal conditions, that is, being the compensated pressure PCequalized with the pressure inside the carbonator tank PR, the modulating valve31is kept 80% opened and the CO2control valve32is kept closed. As mentioned before, the CO2control valve will just be opened if the carbonator tank pressure PRreaches a value lesser than the value of the compensated pressure PC.

The beverage level in the carbonator tank21should always stay between 50% and 90% of the tank21height (tank21volume). When the beverage level is below 50%, beverage control valve34should be opened, and the carbonation process is started. When the carbonator tank21level reaches 90% (point wherein the Venturi Valve (35) is disposed) the beverage control valve34is closed and the beverage input is interrupted.

Before sending the beverage to bottling, the CO2and Brix (sugar dissolved in the beverage) levels needs to be checked. If they are within predicted standards, discharge valve36is opened.

The way the Brix level is checked is not present invention's main aspect, it can be done, for example, by refraction.

Additionally, if the CO2volume in the solution is not in accordance with standard parameters, it will be necessary to recirculate the beverage. By recirculate, it means that the beverage should be discharged from the tank21by opening the discharge valve36and then reintroduced in the tank21by opening the recirculation valve37and the spray ball40.

As the beverage is reintroduced in the tank21by the spray ball40, the beverage recarbonation is possible, or, it is also possible to remove the CO2from the beverage.

In other words, it is possible to increase or decrease the CO2level (volume) in the blended beverage (solution) by managing the spray ball40percentage of opening.

If it is desired to decrease the CO2volume in the beverage, it is necessary to decrease the value of the compensated pressure PC. On the other hand, if it is desired to add more CO2in the beverage, the compensated pressure PCshould also be increased.

The spray ball40is a stainless sphere that has small orifices around its surface to blast beverage in the tank21. Such element (spray ball40) avoids the waste of the carbonated beverage if the carbonation process did not occur as intended, as it can increase or decrease the CO2levels by recirculating the beverage.

The spray ball40control is done by managing the recirculation valve37and a bottling valve (not shown) that is disposed in the entry of the bottling process.

For example, if the CO2volume is above a predetermined level, the compensated pressure PCshould be reduced and the carbonated beverage should be reintroduced in the tank21, as mentioned above.

Further, if the CO2levels are below a predetermined level, the compensated pressure PCshould be increased and the carbonated beverage should be reintroduced in the tank by the spray ball40until the desired CO2level is reached.

The CO2level in the beverage is measured after the beverage has been bottlered. By shaking a sample of a bottlered beverage, the pressure inside the bottle will increase, the relation between such increament of pressure, the beverage temperature and the gas volume dissolved in the beverage will determine the CO2level in the beverage.

The recirculation time depends of the CO2level in the beverage and the CO2volume to be reached. During the recirculation, it is necessary to set the CO2volume and, according to it, the recirculation time will be estimated. According to the recirculation time, the ratio between the recirculation time and the CO2increment volume in the beverage can be determined.

As already mentioned above, during the beverage recirculation, it may be possible to increase or drop the compensated pressure PCaccording to the bottled CO2volume. If the volume is low, the compensated pressure PCis increased, otherwise, the compensated pressure PCis reduced.

The changes in the compensated pressure PCcan be made using a control panel38. A preferably representation of such panel38is represented inFIG. 9. The connection between the panel38and the tank21is not the main aspect of this invention and can be performed by any of the many techniques already known.

As described, with the carbonation duct and carbonation process as proposed in present invention, there is no necessity to discard CO2(vent) to the atmosphere in order to compensate pressure variations in the carbonator tank21and further to compensate beverage temperature variations.

In the proposed process and duct, the CO2is only discarded to the atmosphere in regular period of times, for example, every 3 minutes in order to remove the air trapped at the upper portion of the tank21. This is done by managing the security valve41(FIG. 9).

In fact, in an alternative embodiment, an equipment to remove the air from the beverage could be disposed before the evaporator30, in this case, there would be no necessity to expel CO2to the atmosphere.

The proposed process and its controlling of the mentioned valves are preferably automatically controlled by a Human Machine Interface (HMI), consequently, the equalization between the pressure inside the carbonator tank PR and the compensated pressure PCis done almost instantly, so, the proposed process will not sense any pressure variations for a long period of time.

The details of such HMI are not necessary to be described since it is not the main aspect of present invention. Any HMI able to manage valves known in the prior art teachings could be used. In an alternative embodiment, the method could be manually operated.

Finally, the beverage mentioned in present application should be understood as any material with a viscosity equal or inferior to 0,08 Pa. s (80 cPs).

Preferred embodiments having been described, one should understand that the scope of the present invention embraces other possible variations, being limited only by the contents of the accompanying claims, which include the possible equivalents.