PORTABLE, AUTOMATIC WATER CARBONATOR, REQUIRING NO ELECTRICAL COMPONENTS

Abstract: A portable carbonator includes a built-in CO₂ supply system which operates on disposable gas generating cartridges. The system requires no electrical power and is self-sufficient and automatic. CO₂ gas is generated by a chemical reaction between reagents which carbonates and/or propells the water. Whenever carbonated water is drawn, the reagents react and generate more CO₂ so as to maintain a constant pressure of the carbonated water.

Description: The present invention relates to a carbonator which requires no electrical components and includes a CO₂ gas generator module which generates the gas by a chemical reaction. The water carbonator, in combination with the conventional CO₂-cylinder, comprises a system, which is an essential part of those beverage dispensers which use syrup and water to produce a finished carbonated beverage. Conventional carbonator systems require complex controls firstly to ensure the correct degree of carbonation and secondly to provide a constant water pressure while dispensing. The latter is essential for providing good control of the water-syrup dispensing ratio and a constant carbonation level while water is being drawn. Furthermore the conventional CO₂ supply comprises heavy, high pressure CO₂ cylinders, which are necessarily returnable, refillable packages, are inconvenient in use, and require pressure controls and safety devices. In home-dispensing, a non-pressurized or low-pressure CO₂ package is important, since it simplifies distribution through normal retail channels and provides greater convenience for the non-professional user. In addition, a convenient design of carbonator for home-dispensing is one which is portable, can be filled at the user's sink, and be replaced into the dispenser after filling. Home dispensers are essentially simple devices, with few controls, and in the future some may be fitted into refrigerators, eliminating the need for separate cooling. This in turn implies the need for simple mechanical controls of the carbonation process. However, both the actual carbonation and the generation of gas for dispensing purposes should occur automatically, with minimum user manipulation. Otherwise, the advantages of simplicity and cost-effectiveness are counter-balanced by the lack of essential convenience. US-A-4,040,342 discloses an apparatus for the generation of CO₂ gas and the carbonation of water wherein the CO₂-releasing substance is immersed into the water only after closing the gas generating chamber. The whole mass of the CO₂-releasing substance is immersed into water so that the CO₂ pressure is very high at the beginning and decreases gradually with the delivery of carbonated water. The carbonation level of the water decreases concommittantly. DE-C-45 734 discloses an apparatus for the generation of CO₂ gas at constant pressure in the same way as a Kipp generator. The invention as claimed in claim 1 solves the problem of how to provide a non-electric carbonator which delivers carbonated water at a substantially constant pressure and with a substantially constant carbonation level. Preferred embodiments of the invention are set forth in the subclaims. The carbonator of the present invention uses a substance, such as sodium bicarbonate, which in contact with an acid, such as citric or phosphoric acid, releases carbon dioxide. The two components can be mixed as powders, so that carbon dioxide is generated when water is added. Alternatively, one or both components can be dissolved in water and thereafter gas generation occurs when the two solutions are mixed together. Details of a suitable CO₂ gas generator are also fully disclosed in EP-A-312,078. Chemical generation of CO₂ gas is generally known. Also known are devices, which use this form of gas-generation to carbonate water to a pre-determined degree. These are mostly inconvenient, because they often involve the user in an unacceptable degree of manipulation. Also they are not useable in place of the conventional carbonator/CO₂ cylinder system found in beverage dispensers, since they have no means of maintaining a constant pressure within the carbonator once water is being drawn to feed the dispenser. The carbonator of the present invention is portable and complete with a built-in CO₂-supply system, which operates on disposable gas generating cartridges. It requires no electrical connections and is self-sufficient, and automatic. It demands a minimum amount of manipulation by the user and requires him simply to fill the carbonator, insert the cartridge and replace the cartridge cover and carbonator lid. Nonetheless, once the carbonator is closed, it proceeds to carbonate the water to the correct level, and whenever water is drawn, it reacts by generating more CO₂ so as to maintain a constant pressure. The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings wherein: Figure 1 is an exploded view of a first embodiment of a carbonator of the present invention; Figure 1A is a perspective view of the carbonator of Figure 1 in its assembled state; Figure 1B is a sectional view along line X-Y of Figure 1; Figure 1C is a sectional view along line P-Q of Figure 1; Figure 1D is a partial vertical section of the region of the Figure 1 carbonator containing valves V₃, V₄; Figure 1E is a sectional view along line A-A of Figure 1D; Figures 2A and 2B illustrate the structure of a gas generating capsule for use in the carbonator of the present invention; Figure 3 is a sectional view of another embodiment of a carbonator with the components arranged horizontally; and Figures 4A and 4B illustrate how the carbonator of Figure 3 could be mounted in the door of a home refrigerator. The basic principles are illustrated, by way of example, by Figure 1 and Figures 1A to 1E. The carbonator consists of a lid 20, a main body 22, an intermediate section 24(which houses the pressure-regulating "memory" and the internal channels) and a base 26 into which the CO₂-generating cartridge is inserted. These three sections are shown apart in an "exploded" view in the flow-diagram in Figure 1 to simplify the description. The CO₂-generating cartridge 28, in the particular example shown, comprises two separate parts. Each of these two parts consists of pellets of a mixture of sodium bicarbonate and citric acid (or another suitable solid acid) in a perforated outer package. An air-gap is present between the two parts and one is mounted above the other. In the lower part, reagent R c has the correct proportions for securing the necessary level of water carbonation. In the upper part reagent R p , is proportioned so as to provide adequate gas quantities for propulsion and displacing the entire contents of the carbonator to the dispensing point, while maintaining the required pressure. The main body consists of a large chamber W, which contains the carbonated water and two small chambers A and B, which contain reagent water. All three chambers are filled simultaneously, when the correct water level is reached in the carbonator. The lid 20 simply screws down and seals onto the top of the main vessel and seals the chambers A and B separating them from each other and from W, once the lid is secured. Furthermore, the lid presses down on spring rods 30, (Figure 1B) which run down inside the walls of the main body and open valves V₁ and V₂ as soon as the lid is fully closed. The three-way valve V₃ is normally open to Vent 3 (leading to the top of chamber 24) this position being ensured by spring pressure. When the lid is replaced, a third vertical rod 30, also running down inside the walls of the main body fits into a ratchet (Figure 1D) and prevents the spring from returning the valve V₃, once the valve is set in another position. The user can thus change the position of valve V₃ during operation and it springs back to its normal position only when the lid is removed. The base section 26 can be unscrewed from the central section 22, so that the cartridge 28 comprising reagents R c and R p can be inserted. The user inserts the cartridge 28 before closing the lid 20 of the main chamber W. The system described can be constructed of moulded plastic parts, with in-built channels for the various flows shown and the three valve-actuating rods. The three valves V₂, V₃, V₄ consist of simple plug-cocks and are inserted in prepared borings in the side of the central casting which also contains chamber C. The system operates as follows. As soon as the lid is replaced, valve V₁ opens and the water in chamber A discharges into chamber D flooding the lower part R c of the reagent cartridge 28, Simultaneously, the water in chamber B flows into chamber C. The reagent R c gradually releases CO₂ through the diffuser 32 to effect the required carbonation level in the water in chamber W. The head-pressure in chamber C at the end of the carbonation cycle is equal to that in chamber D and the whole system now reaches pressure equilibrium. The carbonator can be placed into the dispenser either while carbonating or at the end of the carbonation cycle. A simple, self-sealing push-in connector at the base fits onto the dispenser. Once dispensing can begin, the user simply switches valve V₃ to the dispensing position. From that moment, whenever water is drawn out of the carbonator and the pressure in the carbonator drops, the pressure in chamber D also drops and water enters chamber D from chamber C, since this chamber is now at a higher pressure. The water floods the cartridge R p and generates CO₂ until the pressure in chambers W and D have attained equilibrium with the reference pressure in chamber C. When pressure equilibrium has been reached, the water is pushed back into chamber C and the reaction stops. The process repeats itself whenever the pressure in W drops below the reference pressure in C. This reference pressure acts as a pressure "memory" and the pressure "memory" is set by the system itself after carbonation is complete. The above device can easily be fitted into a refrigerator, since it requires no electrical connection and is a self-sufficient, compact unit. However, in certain cases, a horizontal tank may be easier to accommodate in the door of a refrigerator. Figures 2A, 2B and 3 illustrate such a system, using the principles already described. Firstly in Figures 2A and 2B, a suitable gas-generating cartridge 40 is shown. The cartridge 40 consists of a moulded plastic shell 42. The top-section is filled with bicarbonate pellets 44, the middle section with pellets containing a mixture of bicarbonate and powdered acid 46 and the lower section contains a liquid acid 48. The top and bottom sections are connected by a tube 50, which is sealed with foil 52 at the bottom and filter paper 54 at the top. The top and bottom of cartridge 40 are closed by sealing foil 56. Figure 3 shows a sectional view of the carbonator tank. Lid 1 is removed and the tank filled with water up to a pre-determined mark. The reagent water tank 14 is filled at the same time, as soon as the water reaches the required level. When lid 1 is replaced the top of the reagent water tank is sealed. Simultaneously, valve 4 is opened by the pressure which lid 1 exerts on a spring valve actuator. However, the water in the reagent tank cannot as yet flow out, since it is restrained by a second valve 5. Lid 2 is removed and the gas generating cartridge 40 inserted. The cartridge 40 does not reach its lowest position, being restrained by an o-ring 6. When lid 2 is replaced, the cartridge is punctured on the top foil 56 and forced to its lowest position. In its lowest position, the cartridge 40 seals its base 9 against o-ring 7 and its top section 10 against a seal 8. A spring bellows 13 enters the base 3 of the cartridge displacing the acid into the top section. The spike 11 in the center of the bellows opens the channel to the top section through foil 52. When lid 2 is fully closed, valve 5 opens automatically and water from the reagent water chamber flows into the carbonating reagent section 12 of the cartridge. CO₂ gas is released and flows to sparge tubes 60, carbonating the water to the level pre-determined by the quantity of chemicals. The spring bellows 13 has forced acid in contact with bicarbonate and this also generates CO₂, pressurizing the head-space of the tank. As soon as the head-space pressure has reached equilibrium with the spring pressure in the bellows, the spring contracts, the acid returns to the lower chamber and the reaction stops. Thereafter, the process repeats itself, whenever water is drawn out of the carbonator and the head-pressure drops. Figures 4A and 4B show a typical installation of a horizontal carbonator tank in a refrigerator. The tank can now be connected to a dispensing point within or outside the refrigerator. The above principles can also be applied to a vertical carbonator. They also illustrate how a liquid acid may also be used, in place of a solid acid, and how an external fixed pressure reference may be applied in place of the self-generated internal reference as described in Figure 1. The external pressure reference can be by spring pressure (as above), or by an air-cushion or by a membrane or by a piston or by some other similar pressure-exerting device.

Claims: A carbonator comprising a water reservoir chamber (W) having a first adjacent reagent water chamber (A), in which said water chambers can be simultaneously filled with water; a lid (20) for simultaneously sealing said water chambers (W, A); a gas generating chamber (D) including reagents (R c ,R p ) for generating CO₂ gas when the reagents chemically react; means for providing selective contact of the water in said first reagent water chamber (A) with said gas generating chamber (D); a conduit for introducing a first stage of CO₂ gas from said gas generating chamber (D) into said water reservoir chamber (W), thereby carbonating still water within said water reservoir chamber (W); valve means for accomodating the flow of carbonated water from said carbonator means when OPEN and preventing the flow therefrom when CLOSED; characterized by a second reagent water chamber (B) which can be filled with water simultaneously with said water reservoir chamber (W) and said first reagent water chamber (A) and sealed by said lid (20) simultaneously with those chambers (W, A); said selective contact providing means being a first valve (V₁) for providing selective fluid communication of said first reagent water chamber (A) with said gas generating chamber (D), wherein actuation of said first valve (V₁) introduces reagent water from said first reagent water chamber (A) into said gas generating chamber (D), thereby generating CO₂ gas in a first stage; a pressure regulating system (24) for maintaining a predetermined head space pressure in said water reservoir chamber (W) said pressure regulating system (24) including a water chamber (C) in fluid communication with the head space in said water reservoir chamber (W); a second valve (V₂) for providing selective fluid communication of said second reagent water chamber (B) with the water chamber (C) of said pressure regulating system (24), wherein actuation of said second valve (V₂) introduces reagent water from said second reagent water chamber (B) into said water chamber (C); a third valve (V₃) for providing selective fluid communication of said water chamber (C) with said gas generating chamber (D), whereby subsequent to carbonation of water in said water reservoir chamber (W), said third valve (V₃) is actuable to introduce water from said water chamber (C) into said gas generating chamber (D), thereby generating CO₂ gas in a second stage; and a fourth valve (V₄) for selectively introducing at least a portion of the second stage of CO₂ gas into the head space of said water reservoir chamber (W) only upon depletion of at least a corresponding portion of carbonated water from said water reservoir chamber (W), whereby pressure in the head space of said water reservoir chamber (W) is in balanced equilibrium with the pressure in said gas generating chamber (D). The carbonator according to claim 1, wherein said gas generating chamber (26) includes a cartridge (28) having a first reagent (R c ) for producing said first stage of CO₂ gas and a second reagent (R p ) for producing said second stage of CO₂ gas, said first and second reagents being separated by an air gap. The carbonator according to claim 2, wherein said first and second reagents are comprised of bicarbonate and powdered acid. The carbonator according to claim 1, wherein selective actuation of said first and second valves (V₁, V₂) includes fastening of said lid (20) to said water reservoir and first and second reagent water chambers (W, A, B), said first and second valves (V₁, V₂) each including a spring member (30) which is compressed upon application of said lid (20) and released upon removal of said lid (20). The carbonator according to claim 1, wherein said conduit for introducing said first stage of CO₂ gas into said water reservoir further includes at least one CO₂ diffuser (32) positioned on an interior floor of said water reservoir chamber (W) and wherein said conduit is in fluid communication with said gas generating chamber (D).

Inventors: PLESTER, GEORGE
Applicants: THE COCA-COLA COMPANY
Application year: 1988
Main classification: B01F3
IPC codes: A23L2, B01F3, B01F1