Technical Field
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The invention relates to carbonating system for adding carbon dioxide into drinking water comprising a carbonating apparatus and a water container that is removably attachable to the carbonating apparatus, whereby the apparatus comprises a carbon dioxide supply and an feeding outlet for introducing carbon dioxide into the drinking water that is contained within the water container, and whereby the water container comprises an carbon dioxide intake opening that allows for receiving carbon dioxide from the feeding outlet of the carbonating apparatus.
Background of the invention
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There are many different embodiments of carbonating systems and carbonating apparatuses known from prior art. According to the carbonating mechanism that is used for adding carbon dioxide into drinking water and to the design of the carbonating apparatus as well as of the water container, there are specific advantages and drawbacks for each of the carbonating systems.
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Some carbonating systems feed pressurized carbon dioxide into a water container, which allows for carbonating the content of the water container within a few seconds. However, such carbonating systems require a pressurized carbon dioxide supply that is usually provided by a pressure cylinder that must be mounted within the carbonating apparatus and replaced after the carbon dioxide supply of the pressure cylinder is spent after several carbonating cycles. Feeding pressurized carbon dioxide into the interior of the water container also requires the water container to be pressure-tight and to withstand the pressure that is built up within the water container during operation of the carbonating apparatus.
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Other types of carbonating systems make use of a carbonating tank that is arranged inside of the carbonating apparatus. During operation of the carbonating apparatus, drinking water is filled into the carbonating tank and then pressurized carbon dioxide is feed into the drinking water inside of the carbonating tank. After the desired level of carbonation has been reached, the carbonated drinking water is discharged from the carbonating tank into a water container like e.g. a bottle or a glass for storing the carbonated drinking water until consumption.
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Yet other carbonating systems add a carbonating source like a powder or tablet into the water container, whereby the carbonating source generates carbon dioxide that will be absorbed by the drinking water. However, obtaining and adding a carbonating source into the water container adds unwanted burden onto the user. Furthermore, the dissolution of a carbonating source is time consuming and usually requires a large amount of the carbonating source in order to achieve the desired carbonation of the drinking water.
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It is also possible to introduce gaseous carbon dioxide without a large pressure difference into the water container that contains the drinking water. Corresponding carbonating systems can be operated without the need for extensive safety measures for compressive strength. However, the required treatment period for adding gaseous carbon dioxide without a large pressure difference into the water container is usually quite large, compared to the much shorter treatment period that is required for the introduction of pressurized carbon dioxide.
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Accordingly, there is a need for a carbonating system that efficiently adds carbon dioxide to drinking water.
Summary of the invention
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The present invention relates to a carbonating system as described at the beginning, whereby the carbon dioxide intake opening is arranged at or near a bottom side of the water container, whereby the bottom side is the underside of the water container when the water container is connected to the carbonating apparatus during an intended use of the carbonating system, whereby the water container comprises a bubble creating means for creating small bubbles of carbon dioxide that is arranged inside of the water container above the carbon dioxide intake opening, and whereby the bubble creating means forms small bubbles of carbon dioxide that rise towards the upper filling level of the drinking water within the water container during operation of the carbonating system.
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Such bubble creating means provide for at least two beneficial effects. The small diameter of carbon dioxide bubbles that pass through the bubble creating means result in a significantly enlarged total surface of the bubbles compared to the same volume of carbon dioxide that is accumulated within fewer but larger bubbles. A large surface of the carbon dioxide bubbles allows for an enhanced uptake of carbon dioxide into the drinking water. Furthermore, the small diameter of the carbon dioxide bubbles results in a slow rising motion of the small bubbles within the drinking water. Thus, the total time that is required for adding a given amount of carbon dioxide into the drinking water will be significantly reduced by the bubble creating means that is arranged within the water container. It is also possible to reduce the amount or volume of a carbonating source that is introduced into the drinking water to add carbon dioxide into the drinking water.
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The water container with the bubble creating means can be adapted for use with many different methods of carbonating drinking water. The added bubble creating means results in an enhanced uptake of carbon dioxide into the drinking water during the feeding of pressurized carbon dioxide as well as of gaseous carbon dioxide without high pressure difference into the water container. The added bubble creating means also enhance the uptake of carbon dioxide into the drinking water in case that a carbonation source like e.g. a tablet or a powder containing dissolvable carbon dioxide is introduced into the water container. The advantageous effect of the added bubble creating means will be large if the carbon dioxide intake opening is at or near the bottom side of the water container, and the bubble creating means are arranged just above the bottom region where the gaseous carbon dioxide enters into the drinking water inside the interior of the water container, resulting in a long distance for the rising bubbles between the bubble creating means and the upper filling level of the drinking water within the water container.
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It is considered yet another important advantage of the invention that no modification of the carbonating apparatus is required. The same carbonating apparatus can be used in combination with water containers without a bubble creating means or with water containers that comprise a bubble creating means. In particular, a carbonating apparatus that feeds carbon dioxide without a large pressure difference into the water container can be operated much more efficiently without altering the design or the operation of the carbonating apparatus.
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According to a very advantageous aspect of the invention, the bubble creating means comprises a sieve. The carbon dioxide must be fed below the sieve in order to force the rising bubbles to pass through the sieve, which will break up large bubbles into small bubbles. The design and the volume of the sieve can be adapted to provide for sufficiently small bubbles and for a sufficient retention period for the bubbles which then leave the sieve and rise up to the upper filling level of drinking water within the water container. Sieves with a mesh- or hole size that defines the mean size of the bubbles can be produced by different manufacturing methods that are well-known from prior art. Furthermore, bubble creating means like sieves can be manufactured from a material that is food safe and suitable for being in contact with drinking water that is intended for human consumption. Suitable sieves can be manufactured by introducing holes with a small diameter into a plate, panel or sheet. It is also possible to manufacture the sieve from non-woven material made from e.g. plastic or metal. The sieve can be rectangular or disk-shaped. The thickness of the sieve can be adapted to provide for an efficient adding of carbon dioxide into the drinking water.
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Preferably, the sieve has 3 to 100 holes, more preferably 21 to 76 holes, most preferably 40 to 64 holes.
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Preferably the holes of the sieve have a diameter of 0.5 to 5 mm, more preferably 0.7 to 2 mm, and most preferably 0.8 to 1.8 mm.
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The holes of the sieve preferably are spaced apart from one another for 1 to 20 mm, more preferably 2 to 15 mm, most preferably 3 to 7 mm.
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It is preferred that the holes located at the center of the sieve have a smaller diameter than the holes located distal from the center.
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Preferably, the center of the sieve is essentially congruent with the carbon dioxide intake opening of the water container.
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Preferably, the sieve is arranged in the lower third of the water container, with respect to its height, most preferably, it is arranged at the bottom of the water container.
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In the sieve, the holes may be concentrically arranged around the sieve's center, preferably arranged in a concentric pattern of rectangles or circles, more preferably arranged in a concentric pattern of circles. It is preferred that the sieve has 3 to 8 concentric patterns in which form the holes are arranged, more preferably 4 to 6. The phrase "concentric patterns in which form the holes are arranged" as used herein means e.g. that in case of a concentric pattern of rectangles, the holes are arranged on (thought) lines of rectangles, i.e. a plurality of holes is arranged in the form of a rectangle respectively but there are no continuous lines of the rectangle due to the distance between the holes, and in case of a concentric pattern of circles on (thought) circular lines of circles, i.e. a plurality of holes is arranged in the form of a circle respectively but there's no continuous circular line due to the distance between the holes.
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Preferably, in the sieve, the number of holes of the innermost concentric pattern is smaller than the number of holes of the outermost concentric pattern, more preferably 4 to 8 holes are arranged in the innermost concentric pattern, 18 to 30 holes are arranged in the outermost concentric pattern, and the number of holes arranged in the concentric pattern located between innermost and outermost concentric pattern is between 8 and 18.
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The upper part of the sieve, which surface is most distal from the carbon dioxide intake opening of the water container preferably has an essentially flat surface in which the holes are arranged. It is preferred that the upper part of the sieve fully covers a cross-sectional area of an interior of the water container.
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The lower part of the sieve, which is closest to the carbon dioxide intake opening of the water container preferably has channels for distributing the carbon dioxide to the holes. The term "channel" as used herein means any means providing for the aforementioned distribution. Preferably, the channels are formed by walls arranged at the bottom of the essentially flat surface. More preferably, the channels are formed at least by radially arranged walls reaching from the center of said surface to its outermost part. Most preferably, said radially arranged walls together with walls formed around the circumference of the surface define a channel.
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The walls forming the channel provide for distribution of carbon dioxide from the center of said surface to its outermost part. It is preferred that the sieve has 3 to 15 channels, more preferably 8 to 12. Preferably, each channel provides 1 to 10 holes with carbon dioxide, more preferably 2 to 8 holes, most preferably 3 to 5 holes.
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According to an embodiment of the invention, a cross-sectional area of the bubble creating means fully covers the carbon dioxide intake opening of the water container. Thus, all the gaseous carbon dioxide that is fed into the water container through the carbon dioxide intake opening is forced to pass through the bubble creating means. Large bubbles that are created by accumulation immediately after exiting the dioxide intake opening are divided into many small bubbles during the passage through the bubble creating means.
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In yet another embodiment of the invention, a cross-sectional area of the bubble creating means fully covers a cross-sectional area of an interior of the water container. All carbon dioxide that is fed through the carbon dioxide intake opening into the water container can distribute freely over the entire cross-sectional area of the interior of the water container. Due to the large cross-sectional area of the bubble creating means, a large surface of the bubble creating means faces towards the carbon dioxide intake opening and allows for a large volume of carbon dioxide that can enter into the bubble creating means simultaneously and therefore pass through the bubble creating means at the same time. Thus, the total time that is required for a given amount of carbon dioxide to pass through the bubble creating means can be reduced in comparison with a smaller bubble creating means with a smaller cross-sectional area that only covers the carbon dioxide intake opening of the water container.
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The bubble creating means is preferably made from a food safe material that can be fully covered by drinking water over a long period of use. The bubble creating means can also be coated with a bacteria-killing coating like e.g. a silver coating or a coating that contains silver molecules.
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However, it is considered an advantageous but optional aspect of the invention that the bubble creating means is removably mounted within the interior of the water container. The removably attached bubble creating means can be removed from the water container if need arises. A user can replace an already used bubble creating means by a new bubble creating means. It is also possible for a user to clean and sterilize a used bubble creating means e.g. by placing the bubble creating means into boiling water, and to remount the cleaned bubble creating means back into the water container. Furthermore, it is also possible to make use of different bubble creating means e.g. with a different mesh size in order to modify the total addition of carbon dioxide into the drinking water, or to modify the operation characteristics of the carbonating system by increasing the surface of the bubble creating means that is accessible for the carbon dioxide that is fed into the water container through the carbon dioxide intake opening.
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According to a preferred embodiment of the invention, the water container comprises a gas outlet opening that is arranged on a side of the water container opposite to the carbon dioxide intake opening and that can be connected to a gas inlet opening of the carbonating apparatus, and in that the carbonating apparatus comprises a gas reusing conduit that connects the gas inlet opening of the carbonating apparatus with the feeding outlet of the carbonating apparatus to reintroduce gas that is removed from the water container through the gas outlet opening back into the water container through the feeding outlet of the carbonating apparatus. With the gas reusing conduit it is possible to enable a cycle in which the carbon dioxide circulates through the drinking water within the water container, which results in an increased adding of carbon dioxide into the drinking water without increasing the volume of carbon dioxide that is being used up from a carbon dioxide source during the operation of the carbonating system. After the carbon dioxide is fed through the carbon dioxide inlet opening into the water container, the bubbles pass through the bubble creating means and then rise through the drinking water until the bubbles reach the upper filling level of the drinking water inside the interior of the water container. The carbon dioxide then mixes into the air that is trapped inside of the water container. By sucking the gas mixture from the water container through the gas outlet opening of the water container and through the gas inlet opening of the carbonating apparatus into the gas reusing conduit and by feeding the gas mixture from the gas reusing conduit back into the water container, the gas mixture with the enhanced content of carbon dioxide is broken up into small bubbles by the bubble creating means and rises again through the drinking water, thereby adding to the content of carbon dioxide that is added into the drinking water. During usual procedure durations of e.g. two or three minutes, such a cycle of repeated passes of carbon dioxide through the drinking water can be repeated several times.
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The recycling of the carbon dioxide that accumulates above the upper filling level of the drinking water can be operated manually by a user e.g. with an actuating button that moves a piston within a cylinder for creating a suction force that removes the gas mixture from the water container and that creates a pressing force that feeds the gas mixture through the gas reusing conduit and back into the water container.
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However, in order to be able to perform and control the recycling of the carbon dioxide through the gas reusing conduit, the carbonating apparatus comprises a pump for extracting gas out of the water container and for feeding the extracted gas through the feeding outlet back into the water container. The pump can be activated together with the operation of the carbonating system, preferably after a short delay to allow for the accumulation of some carbon dioxide above the drinking water, or optionally as an additional operation step during normal operation of the carbonating system. The pump can be operated electrically and activated or deactivated by a switch or any other control means.
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In order to allow for a simple and convenient mode of operation, the carbonating apparatus further comprises a drinking water supply and a drinking water outlet that can be connected with a drinking water inlet of the water container in order to fill drinking water into the water container before introducing carbon dioxide into the drinking water that is contained within the water container. Thus, a user is only required to connect the empty water container with the carbonating apparatus and to activate the operation of the carbonating apparatus. In a first filling step, the desired amount of drinking water is filled into the water container. The filling of drinking water into the water container can be performed through the drinking water inlet that is arranged preferably at the upper side of the water container or within a cap or lid of the water container. The cap or lid can be removably attached to the water container to also allow for a manual filling of the water container after removal of the cap or lid from a housing of the water container. After the drinking water is filled into the water container, the drinking water inlet is closed and a carbonation cycle of the carbonating apparatus is initiated. During the carbonation cycle, a predefined amount of carbon dioxide is fed into the water container. The carbonation cycle may also include one or more cycles of reusing the gas mixture that accumulates above the upper filling level of the drinking water inside the water container.
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The invention also relates to a water container for use as part of a carbonating system with a carbonating apparatus as described above. According to an advantageous aspect of the invention, the water container comprises a carbon dioxide intake opening that allows for receiving carbon dioxide from the feeding outlet of the carbonating apparatus, whereby the carbon dioxide intake opening is arranged at or near a bottom side of the water container, and whereby the water container comprises a bubble creating means for creating small bubbles of carbon dioxide that is arranged inside of the water container above the carbon dioxide intake opening, whereby the bubble creating means is designed for and suitable for forming small bubbles of carbon dioxide that passes through the bubble creating means. The bubble creating means can be a sieve or any other structure through which gaseous carbon dioxide may pass through and leave the bubble creating means as small bubbles. The bubble creating means is be arranged above the carbon dioxide intake opening, but as near as possible towards the bottom side of the water container. The water container may comprise any feature or combination of features as described above with respect to the carbonating system that includes such a water container.
Brief description of the drawings
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The present invention will be more fully understood, and further features will become apparent, when reference is made to the following detailed description and the accompanying drawings. The drawings are merely representative and are not intended to limit the scope of the claims. In fact, those of ordinary skill in the art may appreciate upon reading the following specification and viewing the present drawings that various modifications and variations can be made thereto without deviating from the innovative concepts of the invention. Like parts depicted in the drawings are referred to by the same reference numerals.
- Figure 1 schematically illustrates a water container with a bubble creating means,
- Figure 2 schematically illustrates the water container with another embodiment of the bubble creating means,
- Figure 3 schematically illustrates a small section inside the water container around the bubble creating means and the effect of the bubble creating means during a carbonating operation that adds carbon dioxide into the water container, and
- Figure 4 schematically illustrates a carbonating system with a carbonating apparatus and a water container that is connected with the carbonating systems.
- Figure 5 schematically illustrates the top view of a particularly preferred bubble creating means 17 in the form of a sieve.
- Figure 6 schematically illustrates the bottom view of the sieve depicted in Figure 5.
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Figure 1 and Figure 2 illustrate two different exemplary embodiments of a water container 1 that can be used in combination with a carbonating apparatus 2 that is shown in Figure 4. The water container 1 comprises a housing 3 that can be made from a transparent plastic or glass or any other suitable material. The housing 3 has a carbon dioxide intake opening 4 that is positioned in a middle region at a bottom side 5 of the water container 1. A bottom cover 6 covers the bottom side 5 and the carbon dioxide intake opening 4 of the housing 3. A valve mechanism 8 that can be operated from outside of the water container 1 allows for feeding carbon dioxide by the carbonating apparatus 2 through the carbon dioxide intake opening 4 into an interior 9 of the water container 1, but closes the carbon dioxide intake opening 4 if the water container 1 is removed from the carbonating apparatus 2. The valve mechanism 8 is neither illustrated nor described in detail, as many different embodiments of a suitable valve mechanism 8 are known to a person skilled in the art. The housing 3 also has an open neck section 10 that is covered by a cap 11. The water container 1 has an overall bottle-like shape.
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The carbonating apparatus 2, for which an exemplary embodiment is shown in Figure 4, comprises a needle-like feeding outlet 12 that passes through the valve mechanism 8 if the water container 1 is arranged on a platform 13 of the carbonating apparatus 2 and properly connected to the carbonating apparatus 2. During operation of the carbonating apparatus 2, carbon dioxide is fed from the feeding outlet 12 through the carbon dioxide intake opening 4 into drinking water 14 that has been filled into the interior 9 of the water container 1 before placing the water container 1 on the platform 13.
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Usually, the gaseous carbon dioxide forms large bubbles 15 as soon as the carbon dioxide leaves the feeding outlet 12 of the carbonating apparatus 2. The large bubbles 15 then rise towards an upper filling level 16 of the drinking water 14 within the water container 1. Due to the large volume of the bubbles 15, only a small amount of large bubbles 15 are created during the feeding of carbon dioxide into the drinking water 14, and the large bubbles 15 rise with a high rising rate that describes the height distance travelled by the large bubbles 15 within the drinking water 14 per unit time.
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Above the carbon dioxide intake opening 4, a bubble creating means 17 is arranged within the interior 9 of the water container 1. The bubble creating means 17 can be e.g. a sieve with a small mesh size that allows for the carbon dioxide to pass through the bubble creating means 17, but to leave the bubble creating means 17 in the form of small bubbles 18 with a mean diameter that is significantly smaller than a mean diameter of the large bubbles 15. Due to the smaller size of the small bubbles 17 that exits the bubble creating means 17 and subsequently rise to the upper filling level 16 of the drinking water 14, the interface between the carbon dioxide and the drinking water 14 is much larger than with the large bubbles 15, and the rising rate is much slower than with the large bubbles 15. Thus, for the same amount of gaseous carbon dioxide that is fed through the carbon dioxide intake opening 4 into the water container 1, there will be a larger uptake of carbon dioxide into the drinking water 14, which results in a better and more efficient performance of a carbonating system that comprises the carbonating apparatus 2 and the water container 1.
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The larger rising rate of the large bubbles 15 before passing through the bubble creating means 17 is indicated by long arrows in Figure 3. The smaller rising rate of the small bubbles 18 that leave the bubble creating means 17 and rise towards the upper filling level that is not shown in Figure 3 is indicated by small arrows in Figure 3.
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The exemplary embodiment of the bubble creating means 17 that is shown in Figure 1 fully covers the cross-sectional area of the interior 9 of the housing 3 of the water container 1. Another embodiment of the bubble creating means 17 as shown in Figure 2 is arranged on top of the carbon dioxide intake opening 4 and only covers the carbon dioxide intake opening 4. Irrespective of the design and shape of the bubble creating means 17, the bubble creating means 17 can be mounted either detachable or permanent inside of the water container 1. The bubble creating means 17 can be fixed e.g. either by snap-in elements or via a screw thread.
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Figure 4 illustrates the carbonating system with the carbonating apparatus 2 and the water container 1 during a carbonating operation. Carbon dioxide that is supplied through a carbon dioxide supply 19 is pumped by a pump 20 through the feeding outlet 12 of the carbonating apparatus 2 and through the valve mechanism 8 and the carbon dioxide intake opening 4 into the water container 1. The at first large bubbles 15 pass through the bubble creating means 17 and become small bubbles 18 that slowly rise towards the upper filling level 16 of the drinking water 14 within the water container 1. During this rise of the small bubbles 18, a volume fraction of the carbon dioxide is added into the drinking water 14. The remaining volume of the carbon dioxide accumulates in the upper region 21 of the water container 1 above the upper filling level 16 and mixes with the air volume in this upper region 21.
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Figures 5 and 6 illustrate top and bottom view of a particularly preferred bubble creating means 17 in the form of a sieve. This sieve has a planar surface with a plurality of holes 26 at its upper part, and its lower part has channels 27 defined by walls 28 arranged at the bottom of the surface, which walls 28 provide for guiding carbon dioxide from the center of said surface to the outermost part of said surface. In this specific embodiment, channels 27 are formed by radially arranged walls reaching from the (circle) center of surface to its outermost part and walls formed around the (circular) circumference of the surface, wherein both radial walls and circumferential wall(s) define a channel having the shape of a circular segment.
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According to an optional mode of operation, the carbonating apparatus 2 also includes a needle-shaped gas inlet opening 22 that protrudes through a gas outlet opening 23 within the cap 11 into the upper region 21 inside the interior 9 of the water container 1. By controlling a three-way valve 24 the pump 20 also sucks a mixture of carbon dioxide and air from the upper region 21 and pumps this mixture through a gas reusing conduit 25 that connects the gas inlet opening 22 of the carbonating apparatus 2 with the feeding outlet 12 of the carbonating apparatus 2. Thus, the mixture of carbon dioxide and air that has been sucked out of the upper region 21 of the water container 1 will be fed back into the water container through the carbon dioxide intake opening 4 and subsequently agains rise through the drinking water 14. Another volume fraction of the reused amount of carbon dioxide will then be uptaken from the drinking water 14 and add into the drinking water 14.
Experimental part
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In the below described Experiments 1 and 2, a bubble creating means in the form of a sieve was used, namely the sieve illustrated in Figures 5 and 6. The sieve had a circular shape and a diameter of 52 mm, which circular shape fully covered the cross-sectional area of the interior of the water container of the carbonating system. As shown in Figure 5, the sieve had a pattern of four concentric circles in which holes are arranged in the form circles respectively, the innermost circle had 4 holes having a diameter of 1 mm respectively, the second circle had 12 holes having a diameter of 1.2 mm respectively, the third circle had 12 holes and a diameter of 1.4 mm respectively, and the outermost circle had 24 holes having a diameter of 1.5 mm respectively.
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As shown in Figure 6, the sieve had 12 channels in the form of 12 circular segments, wherein each channel respectively provides 4 holes of second to outermost concentrical circle with carbon dioxide by guiding carbon dioxide provided by carbon dioxide intake opening 4 from the center of the sieve's surface to the outermost part of said surface, while the 4 holes arranged in the inner circle are directly provided with carbon dioxide by carbon dioxide intake opening 4.
Experiment 1
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A carbonating system was applied in which carbon dioxide was provided by a pressure cylinder. The system pressure of carbon dioxide was 5 bar, and water temperature was 15°C. The carbon dioxide was circulated for 150 seconds, wherein carbon dioxide was introduced through the intake opening at the bottom of the water container of the carbonating system, and sucked off in an upper part of the water container, and recirculated_by means of a gas reusing conduit enabling circulation of carbon dioxide within the water container filled with water.
Table 1: Results of Experiment 1 | Test run No.: | Characteristic: | Result (CO2 concentration) : |
| 1 | Carbonisation without sieve | 4.3 g/L |
| 2 | Carbonisation with sieve | 4.8 g/L |
Table 1 shows that test run no. 2 in which the sieve was applied provides carbonated water with a significantly higher CO
2 concentration compared with test run no. 1 in which no sieve was applied.
Experiment 2
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A carbonating system was applied in which carbon dioxide was provided by chemical reaction of citric acid and sodium hydrogen carbonate. The system pressure of carbon dioxide was 1.2 bar, and the water temperature was 7-9°C. The carbon dioxide was circulated for 150 seconds, wherein carbon dioxide was introduced through the intake opening at the bottom of the water container of the carbonating system, and sucked off in an upper part of the water container, and recirculated by means of a gas reusing conduit enabling circulation of carbon dioxide within the water container filled with water.
Table 2: Results of Experiment 2 | Test run No.: | Characteristic: | Result (CO2 concentration) : |
| 1 | Carbonisation without sieve | 4.9 g/L |
| 2 | Carbonisation with sieve | 5.6 g/L |
Table 2 shows that test run no. 2 in which the sieve was applied provides carbonated water with a significantly higher CO
2 concentration compared with test run no. 1 in which no sieve was applied.
