GB2046112A

GB2046112A - Carbonating a beverage

Info

Publication number: GB2046112A
Application number: GB8009416A
Authority: GB
Original assignee: Thorn Svenska AB
Current assignee: Thorn Svenska AB
Priority date: 1979-03-23
Filing date: 1980-03-20
Publication date: 1980-11-12
Also published as: DE3004440A1; DE3011106A1; FR2451717A1; GB2046112B; SE7902652L

Abstract

A method and appliance for introducing a gas into a liquid enclosed in a container (1), for example, in connection with the domestic production of carbonated drinks in which the gas is supplied through a generally downwardly directed nozzle orifice (5) adjacent the surface (1a) of the liquid in the container, e.g. a bottle. The pressure of the liquid, the diameter of the orifice and the distance of the orifice from the bottom of the bottle are chosen such that the stream (6) of gas just reaches the bottom of the bottle and then breaks up into a multiplicity of small bubbles which rise to the surface, thus ensuring good dissolution of the gas in the liquid. <IMAGE>

Description

SPECIFICATION A method and appliance for introducing gas into a liquid The present invention relates to a method of introducing a gas into a liquid which is enclosed in a container, for example in connection with the manufacture of carbonated drinks, and to an appliance for use in carrying out the method.

Appliances are known for making carbonated drinks in the home, by means of which carbon dioxide can be added to water in a bottle, the water than being flavoured with concentrates.

When supplying carbon dioxide to the bottle, the bottle is clamped in the appliance and a resilient stopper, provided with a nozzle passing therethrough, sealingly engages the opening of the bottle. The nozzle is connected, via a valve, with a source of gas under relatively high pressure.

Moreover, an overpressure safety valve is connected between the space above the liquid surface in the bottle and the surrounding atmosphere.

When using such an appliance for supplying carbon dioxide to water in a bottle, the valve between the source of gas and the nozzle extending down into the bottle is opened and the valve is maintained in an open position until the pressure in the space above the surface of the liquid has increased to a value at which the overpressure valve opens. In order to achieve this, it is usually necessary to open the valve several times to obtain the necessary carbonation, which is of the order of 2 to 4% by volume. In order to achieve this, the overpressure valve must be adjusted to a relatively high value, of the order of 12 bars. The quantity of the gas used being the greater the pressure utilized, the gas consumption necessary for each bottle will be relatively large.

Using a high pressure also requires glass bottles especially made for the purpose.

According to the present invention, we provide the method of introducing a gas into a liquid included in a container, said method comprising the steps of supplying the gas into the liquid from at least one downwardly directed nozzle orifice arranged a short distance beneath the surface of the liquid and selecting the pressure of the gas, the size of the nozzle orifice and the distance of the nozzle orifice from the bottom of the container, such that the gas stream from said at least one nozzle orifice reaches the bottom of the container and the gas ascends therefrom towards the surface of the liquid as a multiplicity of small, individual gas bubbles.

The invention also provides an appliance for introducing a gas into a liquid included in a container, the appliance comprising a support for supporting the container, means for mounting a source of gas under pressure associated with said support, a nozzle insertable into the container when so supported, a valved connection between the supply of gas under pressure and the nozzle, a downwardly directed nozzle orifice in said nozzle, arranged to be a short distance beneath the surface of a liquid when the bottle is so supported, the pressure of the gas in the source, the size of the nozzle orifice and the distance of the nozzle orifice from the bottom of the container being such that the gas stream from said at least one nozzle orifice reaches the bottom of the container and the gas ascends therefrom towards the surface of the liquid as a multiplicity of small, individual gas bubbles.

With such a method and appliance, it is possible to achieve a more efficient admixture of the gas with the water. This has, inter alia, the effect that the gas container need only be connected with the bottle once for obtaining the necessary admixture of gas and it is also possible to operate at a lower pressure in the bottle. In accordance with what has been said above, this results in fewer discharges of gas and a smaller quantity of gas in the only discharge made, which results in a substantially reduced consumption of gas. The lower pressure also means that standard bottles commercially available of the type to be returned to the manufacturer can be used.

The method and appliance of the invention are such that the path of the gas in the liquid enclosed in the container or bottle is as long as possible and the surface exposed by the gas to the liquid is as large as possible.

Previously known appliances do not meet these requirements and have one or more of the following drawbacks. The opening or openings through which the gas is discharged into the liquid in the container or bottle are positioned too close to the bottom, which means that the path of the gas in the liquid will be relatively short. These openings are too large, which results in a few, relatively large, ascending bubbles in the liquid, which decreases the total surface of contact between the gas and the liquid, and increases the risk that liquid will be discharged through the overpressure valve. The openings are obliquely directed towards the wall of the bottle, which prevents the gas from reaching the bottom of the bottle.The gas is reieased under too high a pressure, which results in cavitation occurring in the liquid, which further decreases the surface of contact between the gas and liquid and means that the flow will not be divided up into small bubbles.

As indicated above, according to the present invention, the gas is supplied to the liquid through a generaily downwardly directed nozzle orifice, which is preferably positioned centrally in the bottle, and beneath the liquid surface, the diameter of the nozzle orifice, the distance from the orifice tb the bottom of the container and the gas pressure used being selected so that the gas flow reaches the bottom and the gas then ascends therefrom towards the surface of the liquid in the form of a large number of small individual gas bubbles.

The gas flow should not be so powerful that the gas, after impinging on the bottom of the bottle, is maintained in large bubbles ascending to the surface of the liquid. On the other hand, the flow must not be so weak as not to reach the bottom.

The optimum is to have such a flow which is still coherent when reaching the bottom of the container, but which then, however, will be divided up into a large number of very small bubbles. The other parts of the original flow ~interacting with the liquid have already been divided up into small bubbles ascending towards the surface. However, the result will be that most of the gas will be divided up into very small bubbles in the liquid, which results in a maximum surface area of contact between the liquid and the gas, causing optimum dissolution of gas in the liquid.

The nozzle orifice through which the gas is discharged into the liquid should be positioned as close to the surface of the liquid as possible, however, at such a depth in the liquid that air will not be entrained down into the liquid by the gas flow.

In order that the invention will more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which: Figure 1 is a diagrammatic cross-section through a bottle illustrating the method of the invention; and Figure 2 is a cross-section through one embodiment of appliance according to the present invention.

In Figure 1 there is illustrated a glass bottle 1 of standard type which is designed for a pressure of up to 1 5 bars. The bottle is filled with water 2 to be carbonated. For this purpose a nozzle 3 is connected via a valve (not shown) to a gas container (also not shown) under interior overpressure, the nozzle passing down into the bottle 1 , through a resilient stopper 4, for example made from rubber, which seals the opening of the bottle. The nozzle 3 is provided with a downwardly directed nozzle orifice 5, positioned in the water 2.

The appliance also comprises an overpressure valve connected between the space above the surface of the liquid in the bottle 1 and the surrounding atmosphere. The valve is, however, again not shown in Figure 1.

According to the invention, the cross-sectional area of the nozzle orifice 5 is selected together with the gas pressure of the gas in nozzle 3 and the distance to the bottom of bottle 1, so that the gas flow 6 will be maintained all the way-down to the bottom of the bottle, but there will be divided up into a very large number of small gas bubbles 7, which then ascends towards the surface of the water. With this arrangement, the gas flow 6 will be completely divided up into small bubbles at the bottom and the maximum surface of contact between the gas and the liquid will be obtained, which results in an optimum dissolution of gas in the liquid.In order to maximize the path of the gas in the liquid, the nozzle orifice 5 should be positioned as close to the surface of the liquid as possible, but at such a depth in the liquid that air will not be entrained or sucked down by the gas flow.

When testing an appliance in accordance with the present invention, it has been found that an increase of the order of 25% of the gas dissolution capacity will be obtained as compared to what is obtained when using known appliances. At the same time the appliance can operate with a pressure in the bottle of the order of 6 to 8 bars.

The improved dissolution of gas, thus results in the combination of low pressure in the bottle, requiring only one gas replenishment of the bottle until the overpressure safety valve opens, which gives the result of a significantly reduced use of the gas.

In a preferred embodiment intended for introducing carbon dioxide into a bottle substantially filled with water to a depth of 100 millimetres, while using a gas pressure of 60 bars, the nozzle orifice for the supply of gas being positioned 10 millimetres beneath the surface of the water and having a diameter of 0.3 millimetres will be used. Such an arrangement gives a carbon dioxide/water admixture of the order of 3 to 4% by volume, with one opening of the valve, and the filling of the bottle up to a pressure of the order of 6 to 8 bars.

The invention is, of course, not restricted to the manufacture of carbonated drinks, but could equally be used for the supply of other gases to any kind of liquid.

If reference is now made to Figure 2, there is illustrated therein an appliance utilizing the method of the present invention. There is illustrated mounted in this appliance a bottle 1 filled to a level 1a determined by an exterior bead 1 b on the bottle. The water 2a in the bottle has introduced thereinto a nozzle 3. The top opening in the bottle 1 can be closed by a stopper 4.

The bottle is mounted in a shatterproof housing 10 which can be hinged up to the phantom line position 1 1, together with the nozzle 3, so that the bottle 1 may be inserted. When the shaterproof housing is pivoted back to the position illustrated, a handle 12 can be moved to the phantom line position 13, so that a cam 14 associated with the I handle will lift a table 1 5 to force the bottle upwardly so that its top opening is closed by the stopper 4.

The drawing shows that the nozzle 3 is connected via pipe 1 6 and a manually operable valve 1 7 to a cylinder 1 8 of carbon dioxide under pressure. The valve 1 7 is operated by a manual lever 1 9 and an overpressure valve 20 is connected by a tube 21 to an annular space 22 within the stopper 4 and surrounding the upper end of the nozzle 3.

In use, when the bottle which has been filled to the level 1 a has been introduced into the shatterproof housing 10, and the handle 12 is operated to the position 13, so that the bottle is pressed up against the stopper 4, the valve lever 1 9 is operated, and carbon dioxide is projected out do the nozzle orifice 5 in the nozzle 3 to produce a stream 6 of gas. This gas stream just reaches the bottom of the bottle before breaking up into a multiplicity of small bubbles 7, as described above with reference to Figure 1.

Claims

1. A method of introducing a gas into a liquid included in a container, said method comprising the steps of supplying the gas into the liquid from at least one downwardly directed nozzle orifice arranged a short distance beneath the surface of the liquid, and selecting the pressure of the gas, the size of the nozzle orifice and the distance of the nozzle orifice from the bottom of the container, such that the gas stream from said at least one nozzle orifice reaches the bottom of the container and the gas ascends therefrom towards the surface of the liquid as a multiplicity of small individual gas bubbles.

2. A method as claimed in claim 1, wherein said at least one nozzle orifice is arranged close to the liquid surface, but at a sufficient depth in the liquid that air is not entrained into the liquid by the gas stream.

3. A method as claimed in claim 1 or 2, wherein the nozzle orifice diameter is less than 0.4 millimetres.

4. A method according to claim 3, wherein the diameter of the nozzle orifice is between 0.25 and 0.35 millimetres.

5. A method as claimed in claim 1, 2, 3 or 4, wherein the gas pressure in the container is between 6 and 8 bars.

6. An appliance for introducing a gas into a liquid included in a container, said appliance comprising a support for supporting the container, means for mounting a source of gas under pressure associated with said support, a nozzle insertable into the container when so supported, a valved connection between the supply of gas under pressure and the nozzle, a downwardly directed nozzle orifice in said nozzle, said nozzle orifice being arranged to be a short distance beneath the surface of the liquid when the container is so supported, and wherein the pressure of the gas in the source, the size of the nozzle orifice and the distance of the nozzle orifice from the bottom of the container is such that the gas stream from said at least one nozzle orifice reaches the bottom of the container and the gas ascends therefrom towards the surface of the liquid as a multiplicity of small individual gas bubbles.

7. An appliance as claimed in claim 6, wherein said nozzle orifice is arranged to be positioned immediately beneath the surface of the liquid at such a depth in the liquid that air is not entrained into the liquid by said gas flow.

8. An appliance as claimed in claim 6 or 7, wherein the diameter of the opening is less than 0.4 millimetres.

9. An appliance as claimed in claim 8, wherein the diameter of the orifice is between 0.25 and 0.35 millimetres.

10. An appliance as claimed in claim 6, 7, 8 or 9, and further comprising an overpressure valve connected between the space above the surface of the liquid in the container and the surrounding atmosphere, and wherein said overpressure valve is adjusted at a value of less than 10 bars.

11. A method of introducing a gas into a liquid substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

12. An appliance for introducing a gas into a liquid substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.