Abstract:
A system and a method for the production and provision of C0 2  gas are disclosed. A sealable chamber is equipped with heating means and when a CO 2  carrier material, such as sodium bicarbonate is placed in it and heated to its decomposition temperature CO 2  gas is released. The released gas is conveyed into liquid within a container and when the pressure of the gas in the container raises more and more CO 2  gas is dissolved. The heating may be done by conduction mechanism, a microwave heating mechanism or by induction mechanism. The sodium bi-carbonate or any other material including carbon dioxide may be disposed in powder, solid, suspension, emulsion, solution or wet powder form. It may be disposed in thin envelope case.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Sparkling drinks are manufactured by dissolving carbon dioxide in liquid, typically by pressurizing the liquid with carbon dioxide. When pressure of the sparkling drink is low, bubbles of carbon dioxide may be formed and come out of the solution. 
         [0002]    Carbon dioxide is typically provided as pressurized gas in pressurized tanks or cartridges. For example, Carbonated water may be made by rechargeable soda siphon, or a disposable carbon dioxide cartridge. The soda siphon may be filled with chilled water and carbon dioxide may be added under pressure. Sparkling drinks produced this way tend to be only slightly gassy. 
         [0003]    Alternatively, carbonators or carbonation machines may be used. Carbonators range from home scale machines such as Sodastream™ to large scale carbonators. Carbonators pump water into a pressurized chamber where it is combined with CO 2  from pressurized tanks. The pressurized, carbonated water may be mixed with flavorings, typically in the form of syrups. 
         [0004]    However, pressurized CO 2  tanks are expensive to manufacture and require careful handling. Transportation of the pressurized CO 2  tanks is complicated due to their high weight and high pressure. Also, it is not allowed to send pressurized CO 2  tanks by air in plains. In addition, refill of a pressurized CO 2  tank requires that the tank will be taken to a service site, which is a burden. 
         [0005]    CO 2  may also be provided by chemical reaction of, for example, sodium bicarbonate and citric acid. However, this method is impractical since the chemical reaction results in other materials such as salts that may influence and degrade the taste of the drink Separating the liquid from the salt is complicated and renders this approach impractical. 
         [0006]    U.S. Pat. No. 5,182,084 to Plester discloses a portable carbonator which includes a built-in CO 2  supply system operated on disposable gas generating cartridges. CO 2  is generated by a chemical reaction between reagents which carbonates and/or propels the water. The system disclosed in U.S. Pat. No. 5,182,084 is meant to maintain a constant gaseous pressure whenever carbonated water is drawn. The carbonator disclosed in U.S. Pat. No. 5,182,084 is very complicated, involves a lot of mechanical elements, stationary and movable (dynamic), as depicted for example in  FIG. 4 . 
         [0007]    U.S. Pat. No. 5,350,587 to Plester discloses a CO 2  gas generator which chemically generates the gas from a chemical reaction between two reagents contained within a common container. The generator aims to automatically provide gas so as to maintain the gas headspace pressure in constant reference to a reference pressure. While claiming to provide a device that is easy to use by non-professional users based on disposable gas generator units, in practice the device according to this patent, as may be seen for example in  FIGS. 3A-3L , involves highly complicated mechanical elements including containers within containers, mechanical valves made to control the disposing of the gas and the releasing of the reagents, etc. 
         [0008]    U.S. Pat. No. 4,636,337 to Gupta discloses device and method for dispensing gas CO 2  to carbonate water. The device and method employ gas generator using two chemically active reagents in the presence of water. The device teaches a bleed to maintain the pressure in the headspace at sufficiently high levels while allowing continuous flow of CO 2  through the carbonated liquid. 
         [0009]    U.S. Pat. No. 5,192,513 to Stumphauzer discloses device and method for rapid carbonation of water using chemical reaction taking place in one pressure vessel, transferring the CO 2  to a second pressure vessel. One object of the disclosed device and method is to provide a simple, inexpensive and efficient process for rapidly generating CO 2  and carbonating water. However the apparatus, as disclosed for example in  FIG. 1 , is very complicated and includes a large number of parts, which drives it away from being simple. 
         [0010]    U.S. Pat. No. 5,021,219 to Rudick discloses device and method for self regulating CO 2  gas generator for carbonating liquids. The gas generator consists of two liquid chambers for containing to liquid reagents that when chemically adjoined react and produce the gas. Here also the devices disclosed are complicated, include large number of parts and do not operate with disposable reagent packages. 
         [0011]    GB Patent No. 323102 to Blaxter discloses carbonating apparatus pumping carbonated water together with carbon dioxide to a carbonating vessel which is also supplied with de-aerated water pumped into that vessel and to a mixing pump that provide the water and the carbon dioxide to a carbonating vessel. 
         [0012]    International Patent Application Publication No. WO 94/10860 to Stumphauzer discloses device and method for rapid carbonation of liquids. The device consists of two vessels connected together in which gas is produced using carbon dioxide compound and water that when chemically reacting with the compound produces gas. The device is very bulky and involves large number of parts (valves, seals, springs, conduits and the like). 
         [0013]    International Patent Application Publication No. WO 2011/094677 to Novak discloses system, method and cartridge for carbonating liquid. Carbon dioxide may be provided in a cartridge used to generate CO 2  gas to be dissolved into the liquid. 
         [0014]    US Patent Publication No. 2011/226343 to Novak et al. discloses system method and cartridge for carbonating a precursor liquid to form a beverage. The system and method disclosed by Novak et al. requires charging Zeolite with carbon dioxide by exposing the zeolite to a temperature of 550° C. for a period of 5 hours in a furnace and then immediately transferring the zeolite beads to a sealed metal container, flooding the container with carbon dioxide and pressurizing the container to 5-32 psig for 1 hour. During this process the zeolite beads are charged with carbon dioxide which may be released when exposed to water or other fluids as well as water vapor and humidity. Accordingly, the charged zeolite must be packed in a humidity free facility and in a humidity resistant packaging. It may be appreciated that the above charging process makes the preparation of a cartridge for the preparation of a carbonated beverage relatively expensive. Another disadvantage of the above system and method is the charged zeolite is highly sensitive to humidity and any interaction with humidity or fluids activates the release of carbon dioxide from the cartridge. Thus, the shelf life of such cartridges is limited and requires handling with care to avoid mechanical damage to the sealed packaging of the zeolite in the cartridge. 
       SUMMARY OF THE INVENTION 
       [0015]    A device for providing carbon dioxide gas is disclosed, the device comprising a pressure-sealed pressure chamber adapted to be filled with substance that includes carbon dioxide, a gas conduit connected at its proximal end to said chamber to provide said gas from said chamber, heat energy unit to provide energy to heat said substance in said chamber and a safety pressure outlet to relief pressure from said chamber when said pressure exceeds predefined pressure level, wherein said chamber comprising a base element and a cap element, said base element and said cap element are adapted to keep pressure inside said chamber in closed position and to open and allow inserting and removing substance when in opened position. The method may further comprise activating circulating means to pump liquid from said bottle and to spray it back into the bottle. The method may be characterized so that the providing of heat is done by energizing electrical heater located around said chamber, by using a microwave based heating element, or by providing induction heating energy to the substance. 
         [0016]    Also is disclosed a method for producing sparkling drinks, the method comprising providing pressure chamber and a pressure-sealable bottle-feeding pipe connectable to a bottle, attaching a bottle filled with liquid to the pressure-sealed bottle-feeding pipe in a pressure sealed manner, placing substance that includes carbon dioxide in the chamber, pressure sealing the chamber and providing heat to the substrate. The device may further comprise container cap disposed so that the conduit passes via the cap in a pressure-sealed manner, and the cap is disposed in a distance from the distal end of the conduit so as to ensure that when a container filled with liquid is adapted to and secured said container cap said distal end of said conduit is submerged in said liquid. The device may further comprise circulating means comprising that comprise circulating pump, inlet conduit connected to said pump at its inlet port and made to have its free end submerged in said liquid in said container when said container is attached to said device and filled with liquid and outlet conduit connected to said pump at its outlet port and made to spray liquid received from said pump in the headspace of said container. 
         [0017]    Further is disclosed a capsule for producing gas in a device for providing carbon dioxide gas, the capsule comprising sodium bicarbonate in one of solid, powder, wet powder, solution, emulsion and suspension form. The capsule may further comprise at least one additive form the list comprising: taste additive, flavor additive, and color additive. The additive(s) may be in either solid state or fluid state. The capsule may comprise, additionally or alternatively, chips of ferrous or other material with high magnetic permeability. The capsule may be encapsulated in a thin envelope of non-ferrous material, where the envelope has one or more punctures made in its wall to allow releasing of gas produced in the envelope. The envelope may have more than one compartment. At least one of the compartments may comprise a carbon dioxide carrier material in a solid or powder form and at least one additional compartment may comprise a fluid to wet the carbon dioxide carrier material prior to heating the envelope in order to initiate the gas release from the carbon dioxide carrier material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: 
           [0019]      FIG. 1  is a schematic illustration of a carbonating system, according to embodiments of the present invention; 
           [0020]      FIG. 2  is a schematic illustration of a system for providing pressurized gas for the production of sparkling drinks according to embodiments of the present invention; 
           [0021]      FIG. 3  is a schematic illustration of a system for providing gas for the production of sparkling drinks according to embodiments of the present invention; 
           [0022]      FIG. 4  is schematic illustration of a system for providing gas for the production of sparkling drinks according to embodiments of the present invention; 
           [0023]      FIG. 5  is schematic illustration of a system for providing gas for the production of sparkling drinks according to embodiments of the present invention; 
           [0024]      FIGS. 6A and 6B  are cross section views of two forms of gas production units made across the middle of the gas production units, according to two embodiments of the present invention; 
           [0025]      FIG. 7  is a cross section view of a gas production unit made across the middle of the gas production unit, according to embodiments of the present invention; and 
           [0026]      FIGS. 8A and 8B  are flowchart illustrations of methods for providing gas, such as CO 2 , for the production of, for example, sparkling drinks, according to embodiments of the present invention. 
       
    
    
       [0027]    It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. 
         [0029]    Although embodiments of the present invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed at the same point in time. 
         [0030]    Heating of compositions to a temperature that is higher than the thermal decomposition temperature of that composition, in order to decomposite it is well known Similarly heating compositions to a temperature that is higher than the phase transition temperature, in order to cause the composition to undergo phase transition is well known. For example, heating a composition that includes CO 2  to a temperature that is higher than the thermal decomposition temperature may decomposite it and thus may cause the decomposed material to release CO 2 . In many cases such a process that is known as calcination, or calcination reaction. For example, when limestone is calcinated the chemical reaction is expressed: 
         [0000]      CaCO 3 →CaO+CO 2  (g)
 
         [0000]    That is, the calcination process decomposed the lime stone to lime (calcium oxide) and carbon dioxide. Well known examples of calcination processes, mostly held in large (industrial) scales are meant to remove certain undesired components from the composition. One example is decomposition of hydrated minerals, as in the calcination of bauxite and gypsum, to remove crystalline water. Another example is the decomposition of volatile matter contained in raw petroleum coke and yet another example is the removal of ammonium ions in the synthesis of zeolites. 
         [0031]    Many devices and methods for carbonating liquids are known. Some require complicated and bulky apparatuses and multi stage methods, even for the production of carbonated beverage for personal use. Several known devices and methods disclose the use of pairs of reagents that when chemically activated release carbon dioxide that may be used for the carbonation of the liquid, to create gaseous beverage. Other devices and methods make use of pre-pressurized CO 2  that is contained in high pressure containers from which the pressurized CO 2  may be released into a container holding the beverage in order to carbonate it. Use of pairs of reagents for the production of CO 2  requires means for keeping the reagents apart from each other until the chemical reaction takes place and in many devices known in the art complicated and bulky carbonating apparatuses are required in order to control the process of the carbonation. Use of pressurized CO 2  containers is typically less complicated then the use of carbonating devices based on chemical reaction of pairs of reagents, however handling the containers of the pressurized CO 2  is typically inconvenient and—with non-disposable containers there is the burden of carrying the filled containers from the store and the empty ones back there. 
         [0032]    The inventor of the invention embodiments of which are described herein below has discovered that the amount of CO 2  that may be released from a relatively small amount of sodium bicarbonate during calcination process is relatively very large. For example, from a tablet of sodium bicarbonate weighing 35 grams, when calcinated at temperatures of about 60-200 degrees centigrade CO 2  is released in an amount that is enough to carbonate water or similar liquid in the amount of 1.5 liter having carbonation level of about 2 to 4 volumes, and temperature of 2 to 15 degrees. This ratio of CO 2  production is very high compared to other known methods. This allows producing, at the desire of a user, amount of CO 2  that is enough for a 1 liter container from a sodium bicarbonate tablet weighing about 25 g. 
         [0033]    Heating of materials such as sodium bicarbonate (NaHCO3) or other substances that include Carbon dioxide (CO 2 ), herein after referred to as CO 2  carrier, may release CO 2  gas. For example, when heating sodium bicarbonate in solid form in a closed vessel to temperature higher than the decomposition temperature the following applies: 
         [0000]      2NaHCO 3 (s)         Na2CO 3 (s)+H 2 O(g)+CO 2 (g) 
         [0000]    The same applies, with the required changes, to sodium bicarbonate in other states and forms, such as in dry or wet powder or in solution or emulsion state. 
         [0034]    According to embodiments of the present invention, sparkling drinks, also referred to as carbonated drinks, may be produced by heating CO 2  carrier and by dissolving the released CO 2  gas in water or other liquid such as juice or wine. 
         [0035]    At temperatures above 70° C. (degrees Celsius) sodium bicarbonate gradually decomposes into sodium carbonate, water and carbon dioxide. The conversion is fast at 200° C. For example, heating 8 grams of sodium bicarbonate at 180 degrees Celsius may produce 1.5 liters of CO 2  gas. To reach high carbonation level of commercial sparkling drinks, 3 to 4 liters of gas are needed for each 2 liters of liquid. Therefore, heating of about 16-35 grams of sodium bicarbonate may produce enough gas for 2 liters of sparkling drink. 
         [0036]    According to experiments conducted by the inventor of the present invention, the use of wet powder, suspension or solution of CO 2  carrier, such as sodium bicarbonate, may allow the production of similar amounts of CO 2  gas, at the same production rate, while heating the solution, suspension or wet powder to a lower temperature compared to production from dry powder. For example, heating 25 grams of dry sodium bicarbonate powder to a temperature of 180° C. will yield 2 liters of CO 2  gas in approximately 100-130 seconds. Using the same amount of sodium bicarbonate in a solution form will produce the same volume of CO 2  gas, in similar rate, when heated to a temperature lower than 180° C. It would be appreciated that heating the solution to higher temperatures will provide a higher gas production rate. It should be noted, however, that heating sodium bicarbonate to a temperature of over 200° C. (degrees Celsius) may cause the sodium bicarbonate particles to be sealed and the CO 2  may then be trapped within the particles of the powder. 
         [0037]    According to embodiments of the present invention, when using a CO 2  carrier in a solution, a suspension, an emulsion or a wet powder state, the solvent used for the solution or suspension or the fluid used to wet the powder may be water, edible oil or aromatic oils. Alternatively or additionally, the fluid used as a solvent or to wet the powder may be a flavored fluid. 
         [0038]    Reference is made now to  FIG. 1 , which is a schematic illustration of carbonating system  10 , according to embodiments of the present invention. System  10  may comprise CO 2  production unit  20  which is connected via gas conduit  23  and through gas disposing plug  24  to gas disposing port  23 A. Gas production unit  20  may comprise a gas production base element  20 B, gas production cap element  20 A, heat energy supply unit  20 C and pressure safety valve  20 D. Base element  20 B and cap element  20 A are designed to form a pressure tight chamber  21  having two outlets. First outlet is the connection to gas conduit  23 . This outlet is used for providing pressurized CO 2  when system  10  in use for carbonating. A second outlet is possible via safety valve  20 D, when the pressure inside chamber  21  is higher than a predefined value. Gas conduit  23  may have, close to its distal end, gas disposing plug  24  that may be adapted to tightly and securely attach a container, such as liquid container  100 , and gas disposing port  23 A adapted to be submerged in the liquid in container  100 , in order to provide CO 2  to it. Chamber  21  is designed to accommodate certain amount of CO 2  carrier material, for example in the form of a tablet (or capsule), such as tablet  15 . When chamber  21  contains CO 2  carrier material, such as sodium bicarbonate and is tightly closed, the carrier material may be heated by heat energy supply unit  20 C when energized by electrical energy. When the temperature of carrier material  15  reaches decomposition values heat energy supply unit  20 C may be released and when its pressure climbs high enough (higher than the idle pressure in conduit  23  and container  100 ) CO 2  starts flowing into container  100  and carbonation of the liquid in container  100  begins. The rate of CO 2  production and supply may be controlled, for example, by the control of the temperature of the decomposition. 
         [0039]    Reference is made to  FIG. 2  which is a schematic illustration of system  200  for providing pressurized gas for the production of sparkling drinks according to embodiments of the present invention. According to embodiments of the present invention, system  200  may include high pressure chamber  204  comprising chamber cap element  204 A and chamber base element  204 B. Pressure chamber  204  is connectable to liquid container (or bottle)  201  through pressure-sealed bottle-feeding pipe  202 . Pipe  202  may connect to chamber  204  at one end and to bottle  201 , through pipe outlet  202 B, at the other end. Pipe outlet  202 B may be inserted to bottle  1 , and bottle cap  202 A may be assembled onto pipe  202  to enable sealing the connection of pipe  202  to bottle  201 . CO 2  carrier material unit  205  may be placed in chamber  204  before its cap element  204 A and base element  204 B are tightly closed to each other. System  200  may also include heating device  207  for heating pressure chamber  204  and its carrier material unit  205  contained in it. When pressure chamber  204  is closed and heated, CO 2  carrier material unit  205  inside pressure chamber  204  is heated, and CO 2  gas is released into pressure chamber  204 . The released gas may flow from pressure chamber  204  into bottle  201  through pipe  202 , bottle cap  202 A and pipe outlet  202 B. When at work system  200  may be under pressure of 20-150 psi, or higher. Hence bottle cap  202 A and pipe outlet  202 B forming the connection of system  200  to bottle  201  should sustain the pressure levels of system  200  and be pressure-sealed at these pressure levels, and so should be pressure chamber  204 , bottle  201 , and pipe  202 . 
         [0040]    As is well known in the art, the boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. Thus, raising the pressure surrounding the liquid will result in raising the temperature in which the fluid reaches the boiling point. That is, a liquid at high surrounding pressure has a higher boiling point than when that liquid is at atmospheric pressure. 
         [0041]    According to some embodiments of the present invention, CO 2  carrier material may be placed within CO 2  carrier material unit  205  inside pressure chamber  204  and may be wet prior to heating. When heating CO 2  carrier material in wet form, the fluid serves as a thermal conductor as long as the fluid that wets the CO 2  carrier material remains in a liquid state. Since pressure chamber  204  is pressure sealed, heating of CO 2  carrier material in pressure chamber  204  raises the pressure in the chamber  204 , and thus raises the temperature in which the fluid in chamber  204  vapors. Thus, the fluid preserves its thermal conducting characteristics at higher temperatures than under atmospheric pressure and thus remains effective as a thermal conductor during the heating process of the CO 2  carrier material to temperatures of over 100° C. 
         [0042]    According to some embodiments of the present invention, heating device  207  may be an induction heating device. According to other embodiments heating device  207  may be a microwave heater. 
         [0043]    System  200  may include a temperature regulator  206  that may include a temperature sensor to measure the temperature inside chamber  204  and provide feedback to heating device  207  so as to regulate the temperature to be, for example, between 150 to 400 degrees Celsius. It would be appreciated that when CO 2  carrier material in unit  205  is in a wet form lower temperatures may be required. Furthermore, as noted above, when carrier material is sodium bicarbonate, heating to a temperature of over 200 degrees Celsius is not beneficial. 
         [0044]    CO 2  carrier material unit  205  may be provided in any suitable form such as powder (either dry or wet), tablet, capsule etc. CO 2  carrier material unit  205  may be mixed or otherwise provided with various other flavoring materials that may be released as gas and mix with the drink For example, a tablet may include a layer of sodium bicarbonate and a plurality of layers of additives. 
         [0045]    Reference is now made to  FIG. 3  which is a schematic illustration of system  300  for providing gas for the production of sparkling drinks according to embodiments of the present invention. System  300  may be very much similar to system  200  of  FIG. 2 , however it may further comprise a fan  303  to cool the gas flowing in pipe  320  which may be, for example, spiral shaped to enable more efficient cooling of the produced gas. 
         [0046]    Reference is made now to  FIG. 4 , which is schematic illustration of system  400  for providing gas for the production of sparkling drinks according to embodiments of the present invention. System  400  may comprise CO 2  production unit  20  which is connected via gas conduit  23  and through gas disposing plug  24  to gas disposing port  23 A. Gas production unit  20  may comprise a gas production base element  20 B, gas production cap element  20 A, heat energy supply unit  20 C and pressure safety valve  20 D. Base element  20 B and cap element  20 A are designed to form a pressure tight chamber  21  having two outlets. First outlet is the connection to gas conduit  23 . This outlet is used for providing pressurized CO 2  when system  400  is in use for carbonating. A second outlet is enabled via safety valve  20 D, when the pressure inside chamber  21  is higher than a predefined value. Gas conduit  23  may have, close to its distal end, gas disposing plug  24  that may be adapted to tightly attach a container, such as liquid container  100 , and gas disposing port  23 A adapted to be submerged in the liquid in container  100 , in order to provide CO 2  to it. Chamber  21  may be designed and may function similarly to chamber  21  described with respect to  FIG. 1 . 
         [0047]    According to one embodiment of the present invention, gas production unit  20  may further have an inlet (not shown) for introducing fluid from a source (such as liquid container  100 ), external to gas production unit  20 , into pressure tight chamber  21 , to wet a CO2 carrier material placed within chamber  21  in solid or dry powder form. It would be appreciated by those skilled in the art that the inlet into chamber  21  may further comprise a unidirectional valve (not shown) to prevent gas produced in chamber  21  to exit through the unidirectional valve. 
         [0048]    According to some embodiments, fluid introduced into chamber  21  may be water. According to other embodiments the fluid introduced into chamber  21  may be water with additives, such as flavor and/or color additives. In yet additional embodiments of the present invention, fluid introduced into chamber  21  may be edible oil and/or aromatic oil. According to other embodiments, the fluid may be an emulsion of water and oil such as aromatic oil. It would be appreciated that other fluids may be used. 
         [0049]    System  400  may further comprise circulation means  40 , such as a pump, that is adapted to pump liquid from container  100  via conduit  40 A, the distal end of which is adapted to be submerged in the liquid in container  100  and to return that liquid via conduit  40 B into container  100 . According to one embodiment conduits  40 A and  40 B may pass via disposing plug  24 , however other embodiments may be utilized. According to another or additional embodiment, conduits  40 A and  40 B may pass through a heat exchanger (not shown) to cool down the fluid in conduits  40 A and  40 B to a desired temperature. The end of conduit  40 B that is distal from circulation means  40  may be in a distance from plug  24  that will ensure that it will remain out of the liquid in container  100  when container  100  is substantially in upright position. The liquid that is returned via conduit  40 B may be sprayed into the headspace of container  100 , for example by forming the distal end of conduit  40 B to provide liquid in the form of a spray. Circulation caused by the operation of circulation means  40  may improve (i.e. expend the amount of CO 2  gas dissolved in the container) and speed up the dissolving of CO 2  in the liquid. The inventor of the invention described in this application has discovered that when system  400  is in pressure equilibrium with the pressure inside container  100 , after certain amount of gas was dissolved, the activation of circulation means  40  so that carbonated liquid is pumped from container  100  and sprayed back to its headspace enhances the rate of dissolving the gas in the liquid so that the pressure inside container  100  drops, due to the additional gas that was dissolved in the liquid and therefore the pressure produced by CO 2  production unit  20  is now higher than that inside container  100 , and therefore additional amount of gas is provided to container  100 . Thus, circulation means  40  may be activated continuously or periodically during the production of gas by gas production unit  20  to enable dissolving of larger amounts of gas in the liquid. An acidity indicator that was placed in container  100  indicated repeating raise of acidity of the liquid in container  100  as the activation of circulation means continued, which indicates that the amount of CO 2  gas in container  100  grew with the activation of circulation means  40 . It would be appreciated that any other system and method known in the art for dissolving CO 2  gas in the liquid in container  100  may be used. 
         [0050]    Reference is made now to  FIG. 5 , which is schematic illustration of system  500  for providing gas for the production of sparkling drinks according to embodiments of the present invention. Chamber  20 , conduit  23 , plug  24  and gas disposing port  23 A are built and may function very much like their respective elements in the embodiment of  FIG. 1 . System  500  may further comprise pressure control unit  30 , comprising pressure transmitter/gauge reading  30 A, pressure control unit  30 B and heat control line  30 C. The pressure of the produced gas may be measured in the gas conduit  23  or in similar location. The gas pressure indication may be provided by pressure control unit  30 B. Pressure control unit may be acting as a simple ON/OFF unit that may turn off heat energy supply unit  20 C when the measured gas pressure exceeds a first predefined value and resume heating when that pressure falls below a second predefined pressure value. In other embodiments control unit  30 B may perform more complicated control functions, such a combination of one or more of proportional, derivative and integral (PID) of the difference between the measured pressure and a reference value. Other control functions may also be utilized, to achieve faster response, more accurate resulting pressure, and the like. It will be apparent to one skilled in the art that the amount of heat transferred to the active material, such as tablet  15  of  FIGS. 1 ,  4  and  5  or tablet  205  of  FIGS. 2 and 3 , has an effect on the total amount and rate of release of produced gas, so that when the amount of heat provided causes tablet  15  or tablet  205  to reach temperature that is higher than the decomposition temperature gas will begin to release and temperature higher than that will increase the rate of release. 
         [0051]    Heat may be transferred to tablets, according to embodiments of the present invention, in one or more from a list various heating methods. Reference is made now to  FIGS. 6A and 6B , which are cross section side views of two different forms of gas production units  620  and  630 , respectively, made across the middle of the gas production units, and to  FIGS. 6C ,  6 D and  6 E,  6 F which are optional top views of same, according to two embodiments of the present invention. Gas production units  620  and  630  are designed to transfer heat to respective tablets  650  and  652  in heat conduction mechanism. Heat is produced in heat energy supply unit  620 C,  630 C, which may be formed as heat generators (e.g. one or more electrical heater elements) and is conducted to tablets  650 ,  652  via heating chamber base unit  620 B,  630 B. In order to enable high heat conduction capacity the size of surface area that interfaces with tablets  650 ,  652  the inner bottom face of base unit  520 B,  630 B is made with heat fins protruding from the bottom towards the inside of chamber  620 ,  630  respectively. These protrusions form heat fins  622 ,  632  respectively which in views perpendicular to the plane of view of  FIGS. 6A ,  6 B may have the form as depicted in FIGS.  6 C/ 6 D or FIGS.  6 E/ 6 F respectively, in which the protruding fins are described by the thick black lines. Tablets  650 ,  652  will then be formed respectively with recesses to fit loosely to their respective fins  622 ,  632 . Further improvement in the heat transfer may be achieved by using CO 2  carrier material in a wet form, such as sodium bicarbonate solution or wet powder. As detailed above with reference to  FIG. 4 , according to some embodiments, CO 2  carrier material in tablets  650 ,  652  may be in a dry form and may be wet prior to heating by a fluid introduced into gas production units  620  and  630  via a fluid inlet (not shown). 
         [0052]    Heat may be produced, according to embodiments of the present invention, inside the tablet in the gas production unit, using induction heating mechanism. Reference is made now to  FIG. 7 , which is a cross section view of gas production unit  720  made across the middle of the gas production unit, according to embodiments of the present invention. In this embodiment heat energy supply unit  720 C of gas generating unit  720  is formed as an induction AC electromagnetic generator, as is known in the art for induction heating. Tablet  750  includes, spread substantially evenly inside it, iron or ferrous alloys chips. According to some embodiments these chips may be made of other material having high magnetic permeability. When heat energy supply unit  720 C is energized the electromagnetic energy invokes heating of the iron/ferrous chips inside tablet  750 , which in turn heats the active material of the tablet. In experiments carried out by the inventor of the current invention it was observed that power supplied to heat energy supply unit  720 C was equal to power supplied to heater working in heat conduction mechanism yet the heating of the tablet having same amount of sodium bicarbonate resulted heating to same temperature within time that was shorter compared with heat conduction mechanism, and the amount of produced CO 2  gas was larger compared than the gas produced using heat conduction mechanism. 
         [0053]    Tablets made for use with induction heating may comprise certain amount of ferrous chips calculated to provide enough heating within defined period of time. According to another embodiment the heat generating material may be carbon chips. The size, spherical density and the level of unity of dispersion of the chips in the tablet may be selected to achieve the required level of heating and the time required for that heating. According to some embodiments tablets for the production of CO 2  gas may further comprise taste additives, flavor additives, color additives, and the like. 
         [0054]    In experiments carried out by the inventor of the present invention he discovered that when heating the tablet using induction mechanism the rate of decomposition of the tablet and the rate of gas production may be kept same as in conduction heating with lower temperatures of the heating chamber. 
         [0055]    Heating chamber units  720 A and  720 B may be made of non-ferrous metals which will minimize its heating when electromagnetic energy is activated. 
         [0056]    Reference is now made to  FIGS. 8A and 8B , which are flowchart illustrations of methods for providing gas, such as CO 2 , for the production of, for example, sparkling drinks, according to embodiments of the present invention. In block  810  a system including a pressure chamber and a pressure-sealed bottle-feeding pipe connectable to a bottle is provided. In block  820  the bottle is filled with liquid and is attached to the system in a pressure sealed manner In block  830  CO 2  carrier such as sodium bicarbonate or other substance that includes carbon dioxide is placed in the pressure chamber. In block  840  the pressure chamber is pressure sealed and in block  850  the pressure chamber is heated. As may be seen in block  845  in  FIG. 8B , according to some embodiments of the present invention, after the pressure chamber is pressure sealed, fluid may be introduced into the pressure chamber from an external fluid source, such as from the bottle. The fluid introduced into the chamber, may wet the CO 2  carrier in the pressure chamber and may serve as a thermal conductor. In block  860  the CO 2  gas that is released from the carrier (that is placed in the pressure chamber) flows through the pipe into the bottle. Optionally circulating means may be activated to pump liquid from the container and spray them back to the headspace in the container. The gas is then dissolved in the liquid found in the bottle in block  870  to create sparkling drink 
         [0057]    According to some embodiments of the method according to the present invention, introducing fluid into the pressure chamber may precede the heating of the CO2 carrier within the pressure chamber. 
         [0058]    While embodiments of the present invention were described with relation to preparation of sparkling drinks, embodiments of the present invention are not limited to this application. Carbonated liquids may be produced according to embodiments of the present invention for any other suitable application in which carbonated liquids are required.