WO2009043088A1 - Procédé et installation permettant de produire de l'eau gazeuse - Google Patents

Procédé et installation permettant de produire de l'eau gazeuse Download PDF

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Publication number
WO2009043088A1
WO2009043088A1 PCT/AU2008/001448 AU2008001448W WO2009043088A1 WO 2009043088 A1 WO2009043088 A1 WO 2009043088A1 AU 2008001448 W AU2008001448 W AU 2008001448W WO 2009043088 A1 WO2009043088 A1 WO 2009043088A1
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WO
WIPO (PCT)
Prior art keywords
plant
water
vessel
carbon dioxide
valve
Prior art date
Application number
PCT/AU2008/001448
Other languages
English (en)
Inventor
John Trinwith Ward
Original Assignee
Dorjoviv Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2007905345A external-priority patent/AU2007905345A0/en
Application filed by Dorjoviv Pty Ltd filed Critical Dorjoviv Pty Ltd
Publication of WO2009043088A1 publication Critical patent/WO2009043088A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L2/00—Non-alcoholic beverages; Dry compositions or concentrates therefor; Their preparation
    • A23L2/40—Effervescence-generating compositions
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L2/00—Non-alcoholic beverages; Dry compositions or concentrates therefor; Their preparation
    • A23L2/52—Adding ingredients
    • A23L2/54—Mixing with gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/236—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids specially adapted for aerating or carbonating beverages
    • B01F23/2362—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids specially adapted for aerating or carbonating beverages for aerating or carbonating within receptacles or tanks, e.g. distribution machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20—Mixing gases with liquids
    • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/236—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids specially adapted for aerating or carbonating beverages
    • B01F23/2363—Mixing systems, i.e. flow charts or diagrams; Arrangements, e.g. comprising controlling means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
    • B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
    • B67D1/00—Apparatus or devices for dispensing beverages on draught
    • B67D1/0042—Details of specific parts of the dispensers
    • B67D1/0057—Carbonators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/22—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/40—Further details for adsorption processes and devices
    • B01D2259/41—Further details for adsorption processes and devices using plural beds of the same adsorbent in series

Definitions

  • the present invention relates to methods and plants for producing carbonated water.
  • the present invention relates to methods and plants for producing carbonated water incorporated into a refrigerator.
  • the present invention also relates to a rotary pinch valve .
  • a method for producing carbonated water comprising the steps of: manufacturing a gas containing carbon dioxide on site; and in situ mixing the carbon dioxide with water to produce carbonated water.
  • the method may be of particular application for use in relation to a refrigerator.
  • the method may also be of application in other refrigerated devices such as a water cooler. It is to be understood however, that the method may be used in other applications, such as in respect of a fermentation plant where the fermentation gases can be captured and sent to the plant for the production of carbonated water.
  • the method may operate on a batch or continuous basis.
  • the method may operate on an intermittent or non- intermittent basis.
  • the step of manufacturing a gas containing carbon dioxide may comprise any suitable physical or chemical method.
  • the step of manufacturing a gas containing carbon dioxide may comprise extracting the gas containing carbon dioxide from a larger volume of gas, such as from contaminated air, for example.
  • the step of manufacturing a gas containing carbon dioxide may comprise conducting a chemical reaction to produce carbon dioxide.
  • the chemical reaction is a fermentation reaction. In another particular embodiment, the chemical reaction is a combustion reaction. In another embodiment, the chemical reaction is a steam reformation reaction of hydrocarbons .
  • the method may further comprise the step of purifying the gas containing carbon dioxide.
  • the step of purifying the carbon dioxide may occur by any suitable mechanism such as filtration, electrodialysis, swing sorption, scrubbing or demisting,
  • the step of purification preferably occurs by- swing sorption.
  • the swing sorption may be a thermal, pressure, microwave or electrical swing sorption mechanism or any combination thereof.
  • the step of purification may comprise combined thermal and pressure swing sorption.
  • the step of purification may comprise filtering the gas containing carbon dioxide through at least one membrane, preferably two membranes.
  • the method may also comprise the step of pressurising the purified carbon dioxide.
  • the step of pressurising the carbon dioxide thus occur simultaneously with the step of purifying the gas containing carbon dioxide.
  • the method may also comprise the step of pressurising the water which the purified carbon dioxide is mixed with.
  • the method may also comprise the step of storing the carbonated water produced in a pressurised vessel.
  • the stored carbonated water may be chilled to a temperature of approximately 4 0 C.
  • the carbonated water produced according to the method of this aspect of the invention may have a concentration of carbon dioxide of approximately 4 volumes (at atmospheric temperature and pressure) per volume of water.
  • the step of manufacturing the gas containing carbon dioxide may comprise combusting a hydrocarbon fuel.
  • the hydrocarbon fuel may be natural gas.
  • the natural gas may be supplied from the reticulated supply in urban and commercial areas .
  • the step of combusting natural gas may occur in approximately 20% by volume excess air.
  • the gas produced by combustion of the natural gas may contain approximately 10% by volume carbon dioxide (on
  • the method may also comprise the step of cooling the gas containing carbon dioxide produced by the combustion reaction.
  • the step of sorption of the carbon dioxide may comprise compressing the gas containing carbon dioxide into a sorber/desorber using a compressor.
  • the method may also comprise the step of obtaining water from a water supply for mixing with the carbon dioxide.
  • the water is preferably supplied from the mains water reticulated supply available in urban and commercial areas.
  • the method may further comprise the step of buffering the reticulated mains water supply from any carbon dioxide or pressurised water.
  • the step of buffering the reticulated mains water supply may comprise supplying mains water to a cool water reservoir from which water can be drawn to use in the step of mixing the carbon dioxide with water.
  • the step of purification of the gas containing carbon dioxide by swing sorption may comprise the steps of sorption of the carbon dioxide on a regenerable sorbent in a sorber/desorber followed by desorption of the carbon dioxide from the sorbent.
  • the step of sorption of the carbon dioxide may occur under the influence of raised pressure.
  • the step of sorption may occur under the influence of cooling.
  • the step of desorption may occur under the influence of lowered pressure.
  • the step of desorption may occur under the influence of heating.
  • the step of desorption may occur under the influence of microwave or electrical stimulation or heating.
  • the step of purification by swing sorption may
  • the step of purification of carbon dioxide by swing sorption may also comprise the step of vacuum purging the sorber/desorber of extraneous gases by application of a vacuum on the sorber/desorber.
  • the compressor for the step of sorption of the carbon dioxide may be a first liquid ring compressor, however, it may be any other suitable type of compressor.
  • the method may also comprise the step of recycling the liquid ejected from the first liquid ring compressor outlet to its inlet.
  • the method may also comprise the step of cooling the recycled water from the outlet to the inlet of the first liquid ring compressor.
  • This cooling may be achieved using the cool water reservoir. In another embodiment, this cooling may be achieved using air cooling.
  • the method may also comprise the step of using the water from the combustion reaction as the liquid in the first liquid ring compressor.
  • the step of sorption may comprise relieving gases from the sorber/desorber at a design relief pressure.
  • the design relief pressure may be approximately 50 - 75 psig.
  • the step of sorption may comprise using the relief gases to cool a combustion unit in which the natural gas is being combusted.
  • the sorption step may also comprise pumping cooling liquid through heat exchanger tubes in the sorber/desorber .
  • the cooling liquid may be preferably water.
  • the pump may be a second liquid ring compressor.
  • Cooling of the cooling liquid may comprise
  • the water pumped by the second liquid ring compressor to cool the sorber/desorber may be derived as a take-off on the casing of the second liquid ring compressor.
  • Pumping of the cooling liquid may comprise pumping condensate in the first liquid ring compressor through heat exchange tubing, cooled within the refrigerator, and then through heat exchange tubes in the sorber/desorber and returning the condensate to the first liquid ring compressor suction.
  • the heat exchange tubing cooled within the refrigerator may comprise air cooling or heat exchange tubing passing through a reservoir of cyclic defrost water from the refrigerator.
  • At least a portion of the condensate water pumped by the first liquid ring compressor may comprise as a take-off on the casing of the first liquid ring compressor.
  • the sorption step may also comprise cooling a combustion unit in which natural gas is being combusted using cooling water.
  • the cooling water may be pumped through a jacket of the combustion unit. This may or may not be carried out on start-up of the method.
  • the cooling water for cooling the combustion unit may be the water at the outlet of the heat exchange tubes of the sorber/desorber.
  • the step of pressure release may comprise using the pressure release gases to cool a combustion unit in which natural gas is being combusted.
  • the step of vacuum purge may comprise applying a pressure below atmospheric pressure to the sorber/desorber .
  • atmospheric pressure on the sorber/desorber may be carried out using a compressor, preferably the first liquid ring compressor and more preferably also the second liquid ring compressor.
  • the method may also comprise the step of recovering carbon dioxide from the vacuum purged gases by dissolution of the carbon dioxide in water.
  • the water may be the water within a liquid ring compressor.
  • the step of recovering the carbon dioxide from the purged gases may comprise recycling the purged gases across the first liquid ring compressor and preferably also across the second liquid ring compressor.
  • the step of recovering carbon dioxide from the purged gases may comprise directing the purge gases to atmosphere under pressure through a relief valve on a downstream separator associated with a liquid ring compressor.
  • the step of recovering carbon dioxide from the vacuum purge gases may comprise directing the purged gases through a second sorber/desorber, preferably under pressure through a relief valve, to atmosphere.
  • the step of pressure release and the step of vacuum purge may be part of the same step with the same flow path through a compressor (s) to atmosphere.
  • the method may comprise the step of pressure release on the second sorber/desorber.
  • the method may also comprise the step of switching from the step of vacuum purge to the step of desorption at an optimum pressure between expelling extraneous gases and losing carbon dioxide.
  • the step of desorption may comprise applying pressure below atmosphere to the sorber/desorber.
  • the pressure applied during the desorption step may be lower than the pressure applied during the vacuum purge step.
  • the compressor may be used to apply the pressure
  • the first liquid ring compressor and preferably also the second liquid ring compressor may be used to apply the pressure during desorption on the sorber/desorber.
  • the step of desorption may comprise applying heat to the sorbent by flowing heated water through the heat exchanger tubes in the sorbent.
  • the heated water may be heated sufficiently to enter the heat exchanger tubes as steam.
  • the heated water may be heated using a combustion unit in which the natural gas is combusted.
  • the step of desorption may comprise applying the pressure below atmosphere equally to the second sorber/desorber as well as to the first mentioned sorber/desorber .
  • the method may further comprise the step of venting gases to further remove and act against the build up of extraneous gases.
  • the step of venting may comprise enriching the gases to be vented in extraneous gases in the vapour space of a vessel by contacting the desorbed gases in the vessel with water at least once, on the basis of the preferential dissolution of the carbon dioxide in water.
  • the step of venting may occur solely in the vessel in which the produced carbonated water is stored.
  • the step of venting may also be preferably carried out at least partially in a separate vessel to the storage vessel.
  • the separate vessel in which the step of venting may be carried out is a bottom level float separator.
  • the method may also comprise the step of mitigating any backflow of mains water into the sorber/desorber.
  • the step of mitigating backflow of mains water into the sorber/desorber may comprise using at least one
  • check valve to act against fluid flow in a direction towards the sorber/desorber .
  • the method of mitigating backflow of mains water into the sorber/desorber may comprise desorbing into the vapour space of a vessel.
  • the step of mitigating backflow of mains water into the sorber/desorber may comprise having the condensate water formed in the combustion reaction as the liquid in the liquid ring compressor.
  • the method may comprise the step of using the compressor which compresses gas into the sorber/desorber to act as a fluid displacement pump to pressurise the water which is mixed with the carbon dioxide to produce carbonated water.
  • the step of pressurising the water using the compressor as a fluid displacement pump may comprise pressurising water in a fluid displacement vessel using compressed gases from the compressor.
  • the step of water pressurisation may also comprise pumping the pressurised water from the fluid displacement vessel into another vessel. This step preferably occurs as the water is pressurised.
  • the another vessel may be the separate venting vessel.
  • the venting vessel at some point in the method, may be in fluid communication with the storage vessel in which the carbonated water is stored.
  • the step of venting may be carried out in the venting vessel.
  • the method may also comprise the step of filling the fluid displacement vessel with water.
  • the step of filling the fluid displacement vessel with water may comprise filling the fluid displacement vessel under gravity from the cool water reservoir.
  • the step of venting using the venting vessel may occur after the venting vessel is nominally filled with water.
  • the step of recovering carbon dioxide from vented gas may comprise flowing vented gas through the fluid displacement vessel after the step of filling the fluid displacement vessel.
  • a plant for producing carbonated water comprising an apparatus for manufacturing a gas containing carbon dioxide and a mixer for mixing the carbon dioxide with water to produce carbonated water.
  • the plant may also comprise a purifier for purifying the gas containing carbon dioxide.
  • the plant may also comprise at least one primary compressor for compressing the gas containing carbon dioxide which is mixed with the water to produce carbonated water.
  • the plant may also comprise at least one secondary compressor for pressurising the water which is mixed with the carbon dioxide to produce carbonated water.
  • the primary compressor (s) may be a liquid ring compressor (s) .
  • Any primary compressor may also perform the function of the secondary compressor, preferably as a liquid ring compressor.
  • the primary compressor (s) may be any type of suitable compressor (s) for compressing gases such as a piston, diaphragm or peristaltic compressor.
  • the secondary compressor (s) may be any type of suitable pump(s) for pressurising liquids such as a piston, diaphragm or peristaltic pump.
  • the primary compressor (s) may be of a type of compressor which draws in minimal air from atmosphere when used as a vacuum pump.
  • the piston compressor (s) may comprise a double acting two stage articulating piston compressor (s) .
  • the piston compressor (s) may comprise seals between the piston reciprocating shaft and the housing for minimising air ingress.
  • the reciprocating shaft of the piston may enter the housing via the shaft seal into a more highly pressurised second stage ensuring that leakage past the shaft seal is mainly to atmosphere (as opposed to from atmosphere) .
  • the purifier may comprise a sorber/desorber for purifying the gas containing carbon dioxide by swing sorption.
  • the sorber/desorber may be a pressure swing sorber/desorber .
  • the plant may comprise at least one tertiary compressor for compressing the gas containing carbon dioxide into the sorber/desorber.
  • the tertiary compressor (s) may be a liquid ring compressor (s) .
  • the tertiary compressor (s) may be any type of suitable compressor for compressing gases, such as a piston, diaphragm or peristaltic compressor.
  • Any primary compressor may also perform the function of the tertiary compressor.
  • Any primary compressor preferably as a liquid ring compressor may also perform the function of either the secondary compressor or the tertiary compressor but not both (secondary compressor and tertiary compressor) .
  • the primary and tertiary compressors may have cooling between two successive compressors in series. This cooling may preferably be sufficient to induce substantial
  • the compressor (s) is a peristaltic compressor (s) it may comprise a multi channel compressor (s) with different diameter tubing.
  • the sorber/desorber may be a thermal swing sorber/desorber, preferably in addition to being a pressure swing sorber/desorber.
  • the purifier may comprise a second sorber/desorber for recovery of carbon dioxide from the vacuum purge gases of the sorber/desorber.
  • the sorber/desorber may have heat exchanger tubes for the flow therethrough of a cooling fluid during sorption and a heating fluid during desorption.
  • the cooling and heating fluids are water.
  • the plant may also comprise at least one primary pump for pumping water for cooling and/or heating through the heat exchanger tubes of the sorber/desorber.
  • Any secondary compressor may also provide the function of the primary pump.
  • Any primary or tertiary compressor preferably as a liquid ring compressor, may also provide the function of the primary pump.
  • the first liquid ring compressor may comprise at least one first liquid ring compressor. If more than one then they are preferably arranged in series.
  • the second liquid ring compressor may comprise at least one second liquid ring compressor. If more than one then they are preferably arranged in series.
  • the plant may comprise a first liquid ring compressor stage which provides functions of the primary and tertiary compressors.
  • the plant may comprise a second liquid ring compressor stage which provides functions of the primary and secondary compressors and the primary pump.
  • the plant may comprise a first liquid ring compressor stage which provides functions of primary and tertiary compressors and primary pump.
  • the plant may comprise a second liquid ring compressor stage which provides functions of primary and secondary compressors.
  • the sorber/desorber may contain a sorbent upon which carbon dioxide is preferentially sorbed.
  • the second sorber/desorber may contain a sorbent on which carbon dioxide is preferentially sorbed.
  • the sorbent in the sorber/desorber may be a nontoxic sorbent .
  • the sorbent may be an aqueous based liquid sorbent .
  • the sorbent may be solid and essentially immiscible with water.
  • the sorbent may comprise the salts of an alkali metal or may be a metal oxide.
  • the sorbent may be any suitable solid sorbent such as molecular sieves and sorbents comprising porous substrates with amine function compounds either physically or chemically tethered to them.
  • the sorbent may have a polystyrene, silica gel, polyether, acrylic or carbon molecular sieve backbone and amine functionality, preferably tertiary amine functionality.
  • the sorbent may be an ion exchange resin with primary, secondary or tertiary functional groups or any combination thereof.
  • the sorbent may be a weak base anion exchange resin with tertiary amine functionality and a polystyrene backbone such as Rohm and Haas IRA 96, or Dowex Marathon
  • the functional amine group may be in the free base form.
  • the sorbent may be macroporous.
  • the sorbent may have tertiary amine functionality.
  • the plant may be supplied with water from a water supply.
  • the plant may also comprise a cool water reservoir for providing a buffer between the water supply and any carbon dioxide or pressurised water in the plant.
  • the cool water reservoir may have a level control valve, preferably a float valve which is connected to the water supply, for maintaining the water level in the cool water reservoir.
  • the cool water reservoir may act as an inventory for the water in the plant.
  • the cool water reservoir may be supplied from the mains water supply which is reticulate in urban and commercial areas.
  • the plant may comprise a reservoir of cyclic defrost water from the refrigerator, for cooling circulatory process water via heat exchange tubes or as a source of circulatory process water itself.
  • the plant may also comprise a product drawdown vessel for storing the carbonated water produced by the plant.
  • the product drawdown vessel may also be for dispensing the carbonated water therefrom.
  • the product drawdown vessel even when nominally full may have a significant freeboard of gaseous space to act as a propellant for dispensing.
  • the product drawdown vessel may have an automatic drain float valve for preventing the carbonated water from being dispensed from the product drawdown vessel when the carbonated water is at a low level in the vessel.
  • the apparatus for manufacturing a gas containing carbon dioxide may be a combustion unit for combusting a hydrocarbon in a combustion reaction.
  • the hydrocarbon is natural gas.
  • the natural gas is preferably supplied from the reticulated supply in most urban and commercial areas.
  • the combustion unit may comprise a burner firing
  • the combustion unit may also comprise at least one, preferably two, jackets for the flow therethrough of fluid to cool the firebox. Where the burner has a thermoelectric valve flame safeguard, the thermoelectric valve may be opened for ignition using the capabilities of the system.
  • combustion unit burner, flame safeguard and ignition and re-ignition devices may be shared with another appliance.
  • Individual compressors of the plant may be driven by the same or separate motors .
  • the first liquid ring compressor stage may comprise a first top level float separator, at least one first liquid ring compressor (if more than one they are preferably arranged in series) and a first separator.
  • the second liquid ring compressor stage may comprise a second top level float separator, at least one second liquid ring compressor (if more than one they are preferably arranged in series) and a second separator.
  • the liquid in the first liquid ring compressor may be the condensate water formed in the combustion reaction.
  • the first separator may be for capture at least some of the ejected liquid from the outlet of the first liquid ring compressor and return to the suction side of the first liquid ring compressor.
  • the first separator may return the ejected liquid via the first top level float separator.
  • the returned ejected liquid may be cooled by flow through heat exchange tubing in the cool water reservoir.
  • the returned ejected liquid may be cooled by flow through air cooled heat exchange tubing.
  • the first top level float separator may comprise a high level float valve for preventing the float separator from over flowing with liquid.
  • the high level float valve may close off the ejected liquid inlet from the first separator when the liquid level becomes to high in the first top level float separator.
  • the first top level float separator and the first separator may have a combined volume which is sufficient to hold the volume of condensate produced during a single operational cycle of the plant.
  • the second top level float separator may comprise a high level float valve for preventing the float separator from over flowing with liquid.
  • the high level float valve may close off the ejected liquid inlet from the second separator when the liquid level becomes to high in the second top level float separator.
  • the second top level float separator and the second separator may have a combined volume which is sufficient to hold the volume of condensate produced during a single operational cycle of the plant.
  • the first and/or second liquid ring compressor stage may comprise an automatic drain on its discharge and a separator on its suction.
  • the sorbent may require a moist environment in order to function most efficiently.
  • the moist environment may be provided in the sorber/desorber by the humidity in the gas stream or by condensate overflow exiting the first separator.
  • the plant may comprise a dewatering unit which removes water from feed gases to the sorber/desorber, preferably by condensation of the compressed gases in a refrigerated vessel with subsequent drainage of the condensate to the evaporator.
  • the sorber/desorber may comprise a relief valve for relief of gas depleted of carbon dioxide during sorption at a design relief pressure.
  • the relief valve may direct gas to one of the jackets of the combustion unit to cool the firebox.
  • the relief valve may be located towards the top of the sorber/desorber so as to act against possible particulate contamination of the relief valve from the friable sorbent resin.
  • the relief valve preferably has a design relief pressure of approximately 50 to 75psig.
  • the second liquid ring compressor stage may draw water from the cool water reservoir via during sorption.
  • the second liquid ring compressor may comprise a take-off on its casing for providing the cooling fluid flow during sorption.
  • the sorber/desorber may be positioned outside of the refrigeration space of a refrigerator which the plant is associated with. In another embodiment, the sorber/desorber may be placed inside the refrigeration space. In this embodiment, cooling during sorption would be provided by the refrigerator and cooling water from the cool water reservoir would not be required.
  • the outlet from the sorber/desorber through which relief gas is directed during pressure release may be located slightly above the bottom of the sorber/desorber. This is to leave a well of condensate water at the bottom of the sorber/desorber for acting against the ion exchange resin drying out when not in use, with consequent loss in capacity.
  • the second sorber/desorber may be provided with sufficient humidity or condensate water from the plant to prevent it from drying out.
  • the first and second liquid ring compressor stages may also be for vacuum purging the sorber/desorber to extract a substantial amount of the extraneous gases from the sorber/desorber after sorption.
  • the extraneous gases generally comprise mostly oxygen and nitrogen, particularly nitrogen.
  • the plant may also comprise during vacuum purging, a recycle of the gas exiting the first separator
  • This recycle may be for recovering carbon dioxide from the gas being vacuum purged by dissolution of the carbon dioxide in the water in the first liquid ring compressor stage.
  • the plant may also comprise during vacuum purging, a recycle of the gas exiting the second separator of the second liquid ring compressor stage to the gas flow into the second top float separator.
  • This recycle may be for recovering carbon dioxide from the gas being vacuum purged by dissolution of the carbon dioxide in the water in the second liquid ring compressor stage.
  • the plant may also comprise a vacuum valve to effect a change from vacuum purge to desorption at a designed pressure.
  • the vacuum valve may comprise a pair of parallel tubes, one being collapsible at the designed low pressure or having an in line check valve with an appropriately set cracking pressure and the other tube being non-collapsible at the designed or lower pressures.
  • the vacuum valve may be located on the suction (inlet) side of the first primary compressor.
  • the first and second liquid ring compressor stages may also be for applying a low pressure on the sorber/desorber during desorption.
  • the combustion unit may also be for heating water, the hot water or steam produced being for use in heating the sorber/desorber during desorption.
  • the second liquid ring compressor may also be the mixer for mixing the carbon dioxide with water to produce carbonated water.
  • the plant may also comprise one or more venting vessels for venting desorbed gases from the vapour space thereof, so as to further remove and act against the build up of extraneous gases .
  • the gases to be vented may be enriched in extraneous gases in the vapour space of the vessel by one or more contacts of the desorbed gases in the one or more venting vessels with water.
  • the one or more venting vessels may comprise a bottom level float separator.
  • the bottom level float separator may comprise a float valve for closing the flow of liquid from the bottom level float separator to the second separator at a design low level in the bottom level float separator.
  • the one or more venting vessels may also comprise the product drawdown vessel.
  • the product drawdown vessel may also comprise a relief valve for venting of extraneous gases. In this embodiment it is not necessary for the plant to have the bottom level float separator.
  • the plant may also comprise a PDV fill control mechanism for controlling filling of the product drawdown vessel.
  • the PDV fill control mechanism may comprise a low level switch on the product drawdown vessel for activating filling of the product drawdown vessel with carbonated water upon detection of a design low liquid level.
  • the PDV fill control mechanism may comprise a low pressure switch on the product drawdown vessel for activating input of pressurised carbon dioxide gas to the product drawdown vessel upon detection of a design low pressure level.
  • the PDV fill control mechanism may also be for initiating start-up of operation of the plant.
  • the PDV fill control mechanism may also comprise a low level start-up mechanism which acts against the motor being sent a mixed alternating start-up signal, due to any surface turbulence caused by carbonated water being withdrawn from the product drawdown vessel.
  • the low pressure switch may be separated from the vapour space in the product drawdown vessel by a membrane.
  • the PDV fill control mechanism may also comprise a controllable valve on the liquid recycle between the second separator and the second top level float separator. On a low level start, the controllable valve prevents flow in the liquid recycle line and on a low pressure start allows flow in the liquid recycle line.
  • the controllable valve is preferably a solenoid valve. It may be an on/off or a three way valve.
  • controllable valve may be a three way valve.
  • the three way valve may preferably isolate flow from the product drawdown vessel to the second top level float separator in the event of power failure.
  • the PDV fill control mechanism may comprise a controllable valve on the secondary compressor suction and/or a recycle line from discharge to suction on the secondary compressor.
  • the PDV fill control mechanism may also comprise a downstream check valve on the secondary compressor discharge.
  • the controllable valve may be open on the suction or closed on the recycle line of the secondary compressor.
  • the PDV fill control mechanism may also comprise a processor for monitoring unacceptable gas leakage from the product drawdown vessel by calculating the ratio of low pressure starts to low level starts and comparing it to an acceptable ratio.
  • the plant may also comprise a first check valve for acting to prevent liquid loss from the plant, particularly from the first liquid ring compression stage, when the plant is at rest.
  • the plant may also comprise a back flow
  • the backflow mitigation system is designed to mitigate backflow even when there is no power supplied to the plant.
  • the back flow mitigation system may comprise arranging the sorber/desorber to desorb into the vapour space of the venting vessel or storage vessel.
  • the backflow mitigation system may comprise a check valve located between the sorber/desorber and the cool water reservoir.
  • the back flow mitigation system may also comprise a check valve between the venting vessel and the sorber/desorber .
  • the check valve of the back flow mitigation system is preferably located between the venting vessel and the compressor discharge.
  • the check valve of the backflow mitigation system may at all times only allow fluid flow away from the sorber/desorber.
  • the check valve of the backflow mitigation system maybe located between the second liquid ring compression stage, which uses mains water, and the first liquid ring compression stage, which does not.
  • the backflow mitigation system may also comprise demisters in the first and second top level float separators for extracting excess moisture from the gas in the gas space in the top level float separators.
  • the float valve in the second top level float separator may also form part of the backflow mitigation system by acting against the second top level float separator from overfilling with water and backflowing.
  • the plant may comprise a pump for circulating the cooling and/or heating water during sorption and desorption and a compressor for compressing the purified carbon dioxide, for compressing the gas containing carbon dioxide into the sorber/desorber and also for pressurising
  • the mains water by using compressed gas from the compressor to act as a fluid displacement pump.
  • the plant may also comprise a fluid displacement vessel for holding water to be pressurised by the compressor acting as a fluid displacement pump by compressing gas into the fluid displacement vessel.
  • the venting vessel may also be for receiving the pressurised water from the fluid . displacement vessel.
  • the fluid displacement vessel may be located relative to the cool water reservoir to enable the fluid displacement vessel to be gravity filled from the cool water reservoir.
  • the plant may comprise a vacuum fill vessel for introducing the water into the plant.
  • vacuum may be applied to the vacuum fill vessel using the compressor so as to evacuate the mainly carbon dioxide to the vapour space of the product drawdown vessel whereafter the vacuum in the vacuum fill vessel draws in water from the cool water reservoir.
  • At least one vacuum fill cycle may be performed for a full operational cycle of the plant.
  • the plant may also comprise a valve system for directing the fluid flow during the operation of the plant at the different operation steps.
  • the valve system may comprise a plurality of valves .
  • the valve system may comprise a rotary valve, preferably a rotary pinch valve.
  • the rotary valve may be driven by the same motor that drives any one or more the pumps or compressors in the plant, preferably through a speed reduction unit.
  • the valve system may comprise a three position valve, preferably a pinch or spool valve relying on the
  • valve of the valve system is a pinch valve and under vacuum
  • that valve may be in the open state at rest.
  • the plant may also comprise a pre-cooler for cooling the combustion gases from the combustion unit.
  • the pre-cooler may be finned heat exchanger tubes.
  • the pre-cooler may comprise a vessel containing water, through which the combustion gases are bubbled.
  • the pre- cooler is therefore also for scrubbing and dehumidifying the combustion gases from the combustion unit. The heat lost to the water in the pre-cooler from the combustion gases may be used as a heat source for heating the sorber/desorber during desorption.
  • the burner during desorption may be arranged to provide heat to the water in the pre-cooler via heat exchange through the inner and outer tubes of the combustion gases inlet, so as to replenish heat lost to the sorber/desorber.
  • the pre-cooler may have heat exchange tubes for the flow therethrough of water to be heated during desorption.
  • the pre-cooler may have an inlet for mitigating noise created by the downward flow of condensation against the upward flow of combustion gases entering the pre- cooler from the combustion unit.
  • the pre-cooler inlet may comprise two tubes; an inner tube and an outer tube, the inner tube being located inside the outer tube.
  • the inner tube may be for receiving the combustion gases from the combustion unit at its lower end.
  • the outer tube may be sealed at its upper end, to prevent gases from leaving the outer tube at its upper
  • the outer tube may have spaces provided at the lower end of the outer tube for the gases to pass out of the outer tube and into the pre-cooler.
  • the inlet of the pre- cooler could be an inlet tube surrounded by insulation material or a venturi nozzle, which would also mitigate noise.
  • the top of the inner tube may be above the water level in the pre-cooler when no combustion gases are passing through the pre-cooler and the gas head space in the pre-cooler is at atmospheric position.
  • the top of the outer tube may be submerged below the water level in the pre-cooler when combustion gases flow through the pre-cooler.
  • the plant may also comprise a water balance system for balancing the water produced in the combustion reaction by disposing of water from the plant.
  • the water balance system may comprise an evaporator tray on which the disposed water may be evaporated.
  • Evaporation on the evaporator tray may occur using the waste heat of the refrigerator in relation to which the plant is associated. Evaporation may also occur using other process heat or ambient thermal energy.
  • the disposed water may comprise accumulated water within the first liquid ring compressor stage.
  • the disposed water may comprise accumulated water within the second liquid ring compressor stage.
  • the disposed water may also comprise accumulated water within the sorber/desorber .
  • the disposed water may also comprise water accumulated within the pre-cooler.
  • the disposed water may be collected rather than sent to an evaporator tray, either for physical disposal or incorporation into the carbonated water product.
  • the water balance system may comprise a negative process water balance on the sorber/desorber using makeup water from process condensate or cyclic defrost water produced by the refrigerator to add to the sorber/desorber.
  • the water balance system may also comprise a gravity drainage leg on the pre-cooler.
  • the drainage leg may control the water volume in the pre-cooler by allowing excess water above a design water level to exit the pre-cooler through the drainage leg under gravity, at an appropriate time in the operation of the plant.
  • the drainage leg may have a valve to act against air ingress to the pre-cooler through the drainage leg.
  • the drainage leg may also be for the input of make-up to the pre-cooler in the case where the volume of water in the pre-cooler is such that the water is below a design water level.
  • the plant may also comprise a second backflow mitigation system for mitigating backflow into the pre- cooler.
  • the second backflow mitigation system may also be designed to mitigate backflow even when there is no power supplied to the plant.
  • the second backflow mitigation system maycomprise a check valve between the compressor suction and the pre-cooler vapour space.
  • the purifier may comprise at least one membrane.
  • the purifier may comprise two membranes.
  • the at least one membrane may be an anion exchange membrane, or any other suitable type of membrane.
  • the plant may comprise a further compressor for each of the membranes, for forcing the gas containing carbon dioxide through its respective membrane .
  • the further compressor (s) may be any suitable type of compressor, including a liquid ring compressor.
  • the sorber/desorber of the plant may comprise a membrane contactor.
  • the plant may comprise one or more liquid ring compressors for pressurising the carbon dioxide and water and the mixing thereof to produce carbonated water.
  • the plant may comprise or is integrable with a soft drink plant for producing and dispensing soft drinks.
  • the vapour space of the product drawdown vessel may be used to carbonate syrup in a syrup package and pressurise the syrup for combination with carbonated water from the product drawdown vessel.
  • the vapour space of the product drawdown vessel may be used to carbonate a removable container containing uncarbonated water and uncarbonated syrup.
  • Air in the top of a syrup package or removable container may be vented to atmosphere via a three way valve by at least one pressurising and venting step.
  • the plant may be of particular application for installation in relation to a refrigerator or other refrigerated device such as a water cooler. It is to be understood however, that the plant could be used in other applications, such as in respect of a fermentation plant where the fermentation gases can be captured and sent to the plant for the production of carbonated water.
  • a plant for producing and dispensing carbonated water comprising: a feed of a gas containing carbon dioxide; a feed of water; a mixer for mixing the feeds of gas containing carbon dioxide and water to produce the carbonated water; a vessel for receiving and storing the carbonated water; a dispenser which can be fluidly communicating with the vessel through which carbonated water is
  • the chamber may be located between the vessel and the dispenser.
  • the vessel may also be the mixer and therefore may receive and mix the feeds of gas containing carbon dioxide and water.
  • the venting system may be operable only in association with dispensing of the carbonated water from the vessel.
  • the venting system may be operable only in association with filling of the vessel.
  • the venting system may be operable in association with both dispensing and filling of the vessel.
  • the venting system may be operable to enable venting of at least a portion of the accumulated gas upon dispensing of the carbonated water from the vessel.
  • the venting system may be operable to enable venting of at least a portion of the accumulated gas immediately after dispensing from the vessel has been completed.
  • the venting system may be operable to enable venting of at least a portion of the accumulated gas immediately after filling of the vessel is completed.
  • the venting system may be operable to enable venting of at least a portion of the accumulated gas on commencement of filling.
  • the venting system may be operable to vent accumulated gas through the dispenser.
  • the venting system may enable venting of at least a portion of the gas accumulated in the chamber by flowing
  • the venting system may be operable to enable the vented gas to flow in advance of the carbonated water being dispensed.
  • the venting system may be operable to enable venting of at least a portion of the gas accumulated in the chamber by opening the chamber to atmosphere.
  • the venting system may be operable to isolate the chamber when venting at least a portion of the gas accumulated in the chamber.
  • the venting system may be operable to vent accumulated gas in parallel with the dispenser, preferably upon dispensing of the carbonated water from the vessel.
  • the venting system may comprise a restrictive device for restricting the flow of gas being vented from the chamber.
  • the restrictive device may be located between the chamber and atmosphere.
  • the restrictive device may be an orifice or a pressure relief valve which may have cracking pressure less than the equilibrium pressure in the vessel.
  • the venting system may comprise a multiport valve operable to vent at least a portion of the gas accumulated in the chamber, preferably in parallel with dispensing of carbonated water through the dispenser.
  • the chamber may be vented to the atmosphere via a check valve upstream or downstream of the external chamber.
  • the chamber may be vented to atmosphere via a suitable length of narrow diameter tubing downstream of the external chamber.
  • the chamber may be located externally or internally of the vessel or may be located in part external to the vessel and in part internal to the vessel. Where the chamber or a portion of the chamber is located internally of the vessel, the plant may comprise a level control valve for creating the chamber or chamber
  • the level control valve may be a float valve.
  • the feed of a gas containing carbon dioxide may be pressurized above atmospheric pressure.
  • the feed of a gas containing carbon dioxide may be a feed of close to pure carbon dioxide.
  • the feed of a gas containing carbon dioxide may be provided from a pressurized cylinder of carbon dioxide.
  • the feed of a gas containing carbon dioxide may be provided from any other suitable source, such as from the combustion of natural gas for example.
  • the feed of water may be pressurized above atmospheric pressure.
  • the feed of water may be provided from a mains water supply.
  • the plant may comprise a suitable pump or pumps for pressurizing the water and/or the gas containing carbon dioxide from their respective feed pressures.
  • the plant may be incorporated into a refrigerator.
  • the plant may be incorporated into a water cooler.
  • the carbonated water may be dispensed from the plant incorporated into the refrigerator in conjunction with cold still water.
  • the plant may also comprise a still water holding tank for holding a volume of water.
  • the still water holding tank is fluidly located between the feed of water and the vessel.
  • the plant may also comprise a treatment device for treating the feed of water.
  • the treatment device may be fluidly located before the still water holding tank.
  • the treatment device may comprise a carbon filter.
  • the plant may comprise a gas regulator or supplying pressurized gas containing carbon dioxide to the
  • the plant may comprise a pump for pumping water into the vessel.
  • the plant may also comprise a break tank for acting as a reservoir of feed water for the plant from which the pump pumps water to the vessel.
  • the break tank may be located between the pump and the still water holding tank.
  • the break tank may have a level control valve, preferably a float valve, operable to enable water to be fed into the break tank from the water feed.
  • the break tank may also act as a backflow mitigation system for mitigating against the backflow of water to the feed of water.
  • the break tank may be provided with an air gap between the maximum water level in the break tank and the level at which the level control valve operates to enable water to enter the break tank.
  • the break tank may have a drain above a maximum water level in the break tank.
  • the break tank drain may be fluidly connected to an evaporator tray beneath the refrigerator.
  • the pump may be an electrically driven pump or a pneumatic pump such as a double acting diaphragm pump or double acting piston pump.
  • the pump may use the pressure of the compressed gas containing carbon dioxide to power the pump.
  • the gas pressure used to power the pump may be the pressure of the gas pressure regulator.
  • the pump may have a volumetric flowrate capacity at the pressure existing in the vessel that is less than the volumetric flowrate from the dispenser.
  • the volumetric flowrate of the pump may be 1-
  • the pump may be activated solely by the maximum
  • the plant may comprise a three way valve downstream of the gas pressure regulator operable to direct gas containing carbon dioxide to the pneumatic pump when filling the vessel or directly into the vessel via a pump check valve when in the rest position.
  • the pump check valve may have a sufficient cracking pressure for maintaining a suitable gas pressure differential for pumping into the vessel.
  • the gas exhausted from the pneumatic pump and the water pumped by the pneumatic pump may enter the vessel separately.
  • the water and the gas containing carbon dioxide may have contacted prior to entry into the vessel in the mixer.
  • the mixer may be a premixing vessel or a premixing point where the feeds meet.
  • Carbon dioxide in the gases vented from the vessel may be at least be partially recovered by contact with water about to enter the vessel.
  • the plant may be arranged to bubble the vented gases through the water in the break tank.
  • the plant may be also comprise an inverted bucket located in the break tank, for receiving the vented gases.
  • the vented gases may enter the inverted bucket through the top or bottom of the inverted bucket or in any other manner and preferably via a check valve.
  • the inverted bucket may have an open bottom.
  • the inverted bucket may have an orifice formed in a closed top.
  • the orifice may mate with a fixed sealing member rigidly attached to the break tank.
  • the inverted bucket in a rest position may sit within a sleeve on footings.
  • the sleeve and footings may further be supported by a base rigidly attached to the break tank.
  • the base may be perforated.
  • the inverted bucket may- have a totally closed top and be rigidly attached to a perforated base which is itself rigidly attached to the break tank.
  • the inverted bucket and/or its connections may be formed of a suitable permeable material to mitigate against the accumulation of gases in the inverted bucket .
  • the vessel may comprise a minimum liquid level mechanism for maintaining a minimum liquid level in the vessel .
  • the minimum liquid level may be above the carbonated water outlet from the vessel.
  • the minimum liquid level mechanism may not rely on the flowrate capacity of the pump being greater than the dispenser flowrate.
  • the minimum liquid level mechanism may comprise an automatic drain on the outlet from the vessel.
  • the automatic drain may comprise a buoyant ball on a seat.
  • the buoyant ball may float when water in the vessel is at or above the minimum liquid level of the vessel, thereby opening the outlet from the vessel.
  • the minimum liquid level mechanism may comprise a level switch and a solenoid valve.
  • the vessel may comprise inner and outer passages.
  • the inner and outer passages of the vessel may be in fluid communication and may provide opposing flow paths .
  • the inlet of the inner passage may be located at the same end of the vessel as the outlet of the outer passage.
  • outlet of inner passage may be located at the same end of the vessel as the inlet of the outer passage.
  • the outlet of the inner passage may be connected to the inlet of the outer passage. This connection may be
  • the outlet of the outer passage may be connected to the inlet of the inner passage, possibly via an automatic drain float valve.
  • the outlet passage of the vessel may be connected to the minimum liquid level mechanism.
  • the vessel may also comprise a tube or tubes which separate the inner and outer passages.
  • the passages of the vessel may be aligned substantially horizontally or vertically.
  • the vessel may comprise a plurality of passages.
  • the plurality of passages may provide opposing flow paths .
  • the plurality of passages may be in the form of a hose tank.
  • the vessel is a hose tank, it may comprise a plurality of passages.
  • the plant in this arrangement may also comprise a number of chambers for accumulating gas which may or may not be located at the top of the passages.
  • the vessel may be arranged to receive the gas containing carbon dioxide into the top of the vessel, into either the inner or outer passage.
  • the vessel may be arranged to receive the water into the top of the vessel into the same passage as the gas containing carbon dioxide is received.
  • the vessel may be arranged to receive the gas containing carbon dioxide and the water in any suitable way.
  • the gas containing carbon dioxide may enter as bubbles below the water surface in the vessel.
  • the vessel may be arranged to dispense carbonated water in any suitable way such as from the top, side or bottom of the vessel.
  • the vessel as a hose tank, may be arranged to receive gas containing carbon dioxide and water together or separately in any suitable way such as into the top, side or bottom of the hose tank and to dispense carbonated
  • the passages of the hose tank may be aligned substantially horizontally or vertically.
  • the vessel may or may not be arranged to be full of liquid when the plant is at rest and at equilibrium.
  • the vessel may be arranged so that in operation, most of the mixing of the water and the gas containing carbon dioxide is done in the inlet passage of the vessel. Where the water enters at the top of the vessel, it may enter as a spray or droplets or may be directed to flow over an extended surface area which may include the walls of the inner passage.
  • the plant may also comprise a backflow mitigation system for mitigating backflow of carbon dioxide gas and/or carbonated water from the vessel into the feed of water.
  • the backflow mitigation system may comprise a pressure differential valve for acting to maintain the pressure of the carbon dioxide below the pressure of the water between the vessel and the feed of water, more preferably between the vessel and the holding tank. This pressure differential could, however, be achieved in any other suitable way.
  • the backflow mitigation system may comprise a check valve for acting against the backflow of carbonated water or carbon dioxide gas from the vessel.
  • the check valve may be of a type required by regulatory authorities .
  • the backflow mitigation system may also comprise a three way valve controllable by a fill signal from the vessel for acting against the backflow of carbonated water from the vessel. In this embodiment, the water level in the vessel may be controlled by a float switch acting on the three way valve .
  • the three way valve of the backflow mitigation system may be a solenoid valve. Where it is a solenoid valve preferably it has no power applied to it in the rest
  • the three way valve of the backflow mitigation system may be a mechanical three way valve such as a float operated spool valve or a diaphragm valve.
  • the three way valve of the backflow mitigation system may be located between the pressure differential valve and the vessel.
  • the three way valve of the backflow mitigation system may be located upstream of the check valve.
  • the upstream side of the check valve may be in fluid communication with atmosphere in the rest position via one flow path of the three way valve of the backflow mitigation system.
  • Gaseous flow to atmosphere from the vessel may be prevented by the check valve of the backflow mitigation system.
  • the plant may also comprise a controller for controlling water flow into the vessel.
  • the controller may enable the relative amount of carbon dioxide to water flowing into the vessel to be adjusted.
  • the controller may comprise at least one restriction device in the water feed to the vessel.
  • the restriction device may be located downstream of the pressure differential valve.
  • the restriction device may comprise a throttling valve .
  • the gas containing carbon dioxide may enter the vessel with the water through a single conduit.
  • the vessel may have additional controllable two position valving on the flow paths to the vessel of the water or carbon dioxide such as a controllable on/off valve on the water flow path upstream of the mixing point or a controllable three way carbon dioxide valve with separate flow paths to the mixing point and the vessel.
  • the additional controllable two position valving may be part of a multi function valve and may be activated by a water level in the vessel or a timing signal.
  • the timing signal may be at the end of a period initiated by the dispensing valve.
  • the venting system may comprise a three way valve .
  • the three way valve of the venting system may be operable to fluidly connect the vessel to the dispenser to enable dispensing of the carbonated water from the vessel.
  • the three way valve of the venting system may be referred to as a "three way dispensing valve" .
  • the three way valve of the venting system when at rest and no carbonated product is being dispensed may be arranged so that the top of the inner passage and the top of the outer passage are in fluid communication via the chamber.
  • the chamber may be located above the top of the passage where the gas containing carbon dioxide enters the vessel .
  • the chamber may be located above the "at rest” maximum water level in the vessel.
  • the three way valve of the venting system for dispensing from the dispenser may be arranged to fluidly connect the top of the outer passage of the vessel to the dispenser.
  • the three way valve of the venting system may be arranged to fluidly connect the top of the inner passage of the vessel to the dispenser.
  • the three way valve of the venting system may be arranged to enable the chamber to be fluidly communicating to the dispenser. In doing so, this enables the accumulated gases in the chamber to be vented to atmosphere via the dispenser.
  • the plant may be arranged, whereby, upon dispensing from the vessel, gas containing carbon dioxide
  • the venting system may also comprise an on/off valving mechanism fluidly located between the top of the inlet passage and the three way valve of the venting system for allowing gaseous fluid communication between the top of the inlet passage of the vessel and the chamber only upon the detection of a high liquid level in the inlet passage and/or a high concentration of extraneous gases in the vessel.
  • the on/off valving mechanism may comprise a level control valve.
  • the level control valve may be a float valve .
  • the venting system may also comprise a buffer volume between the three way dispensing valve and the dispenser.
  • the buffer volume may act against an unacceptable blast of pressurized gas exiting the dispenser on dispensing.
  • the venting system may also comprise a ball float valve .
  • the ball float valve may be located between the three way valve of the venting system and the dispenser.
  • the ball float valve may have a vertical leg connected thereto.
  • the ball float valve may be arranged to loosely close off fluid communication with the dispenser by gravity to initially allow vented gases to escape to atmosphere, preferably through the vertical leg.
  • the ball float valve may also be arranged whereby as carbonated water flowed through, the ball float would rise to close the vertical leg and open fluid communication with the dispenser.
  • the venting system may comprise a well drained line from the three way valve to the dispenser.
  • the three way valve may be above the dispenser.
  • the venting system may comprise flow channels
  • the venting system may comprise a multiport valve for providing the functions of the three way dispensing valve and the ball float valve discussed above.
  • a chamber which had been in fluid communication with the vapour space at the top of the inlet passage of the vessel is isolated and then vented and simultaneously or sequentially liquid product flows to the dispenser.
  • the venting system may comprise an on/off valve rather than the three way valve .
  • the plant may comprise or may be integrable with a soft drink plant for producing and dispensing soft drinks .
  • the plant for producing soft drinks may comprise at least one syrup package and/or removable container and at least one manually activated three way valve.
  • the vapour space of a syrup package or removable container may be vented by at least one set of successive pressurizing and venting steps .
  • a method for producing and dispensing carbonated water comprising: providing a gas containing carbon dioxide; mixing the gas containing carbon dioxide with water to produce the carbonated water; filling a vessel with the water gas mixture; allowing gas from the water gas mixture in the vessel to accumulate in a chamber; dispensing carbonated water from the vessel as required through a dispenser; and venting at least a portion of the accumulated gas from the chamber in association with dispensing carbonated water from the vessel and/or in association with filling the vessel with the water gas mixture.
  • the method may be carried out using the plant according to the third aspect of the present invention.
  • the gas containing carbon dioxide may be produced on site with the other steps of the method for producing and dispensing carbonated water.
  • the step of providing the gas containing carbon dioxide may comprise producing the carbon dioxide by combusting natural gas.
  • the steps of providing the gas containing carbon dioxide and mixing with the water may comprise producing and mixing the gas containing carbon dioxide in accordance with the processes described in the first aspect of the present invention.
  • the step of providing the gas containing carbon dioxide may comprise the provision of a pressurized cylinder of carbon dioxide.
  • the gas containing carbon dioxide may be close to pure carbon dioxide.
  • the water may be provided from a mains water supply .
  • the method may comprise pumping the water from a feed of water using a pump, preferably to the vessel.
  • the feed of water may be the mains water supply.
  • the method may comprise holding a volume of water in a break tank between the feed of water and the pump.
  • the water pressure in the break tank is below the pressure of the feed of water.
  • the pump may have a volumetric flowrate capacity at the pressure existing in the vessel that is less, preferably much less, than the volumetric flowrate rate from the dispenser.
  • the volumetric capacity of the pump may be 1- 250mL/min, preferably l-50mL/min
  • the step of mixing may occur in the vessel.
  • the step of mixing may occur prior to the water and gas entering the vessel, such as in a pre-mixing vessel or at a pre-mixing point for example.
  • the water may comprise inputting the water and/or gas containing carbon dioxide into the top of an inner or outer passage of the vessel.
  • the step of dispensing carbonated water from the vessel may comprise flowing carbonated water from the top of an outer or inner passage of the vessel.
  • the step of venting may occur only in association with the step of filling the vessel with the water gas mixture .
  • the step of venting may occur only in association with the step of dispensing.
  • the step of venting may occur in association with both the step of dispensing and the step of filling.
  • the step of venting may occur immediately after the step of filling is completed.
  • the step of venting may occur during the step of dispensing.
  • the step of venting may occur immediately after the step of dispensing is completed.
  • the step of venting may occur upon commencement of the step of filling.
  • the step of venting may occur immediately prior to the step of dispensing.
  • the step of venting may comprise flowing the carbonated water being dispensed in the step of dispensing through the chamber. By doing this, the dispensed carbonated water pushes at least some of the accumulated gas in the chamber out through the dispenser.
  • the step of dispensing may comprise rearranging a venting system to bring the dispenser in fluid communication with the vessel via the chamber.
  • the step of dispensing may comprise rearranging a three way valve .
  • the venting system When dispensing is not occurring, the venting system is arranged wherein the top of the inner passage of the vessel is in fluid communication with the top of the outer passage of the vessel. This may be via the chamber.
  • the method may also comprise the step of operating a level control valve within the vessel to create the chamber or at least a portion of the chamber above the water level in the vessel.
  • the level control valve may be a float valve .
  • the step of mixing the gas containing carbon dioxide and water may comprise inputting the gas containing carbon dioxide and water into a hose tank together or separately in any suitable way into the top, side or bottom of the hose tank.
  • the step of dispensing carbonated water from the hose tank may comprise flowing the water in any suitable way from the top, side or bottom of the hose tank.
  • the method may also comprise the step of refilling the vessel with water and/or gas containing carbon dioxide .
  • the step of refilling may be initiated when the step of dispensing is initiated.
  • the step of refilling may occur simultaneously with the step of dispensing.
  • the method may also comprise the step of treating the water prior to mixing it with the gas containing carbon dioxide, by for example flowing the water through a carbon filter.
  • the method may also comprise the step of holding feed water to the vessel in a holding tank.
  • a plant for producing and dispensing carbonated water comprising: a feed of a gas containing carbon dioxide; a feed of water; a mixer for mixing the feeds of gas containing carbon dioxide and water to produce the carbonated water; a vessel for receiving and storing the carbonated water; a dispenser which can be fluidly communicating with the vessel through which carbonated water is
  • dispensed from the vessel a chamber for accumulating gas from the gas-water mixture held in the vessel; and a pump for pumping water into the vessel, the pump having a volumetric flowrate capacity at the pressure existing in the vessel that is less than the volumetric flowrate from the dispenser.
  • a plant for producing and dispensing carbonated water comprising: a feed of a gas containing carbon dioxide; a feed of water; a vessel for receiving towards the top of the vessel the feeds of gas containing carbon dioxide and water and storing the produced carbonated water, the vessel being in the form of a hose tank; and a dispenser which can be fluidly communicating with the vessel through which carbonated water is dispensed from the vessel.
  • a refrigerative apparatus incorporating a plant according to the second, third, fifth or sixth aspects of the present invention.
  • the refrigerative apparatus may be a refrigerator or any other suitable device such as a water cooler. At least the vessel and the dispenser of the plant may be located in the door of the refrigerator.
  • An upper portion of the vessel of the plant may be insulated.
  • a lower portion of the vessel near the bottom of the refrigerative apparatus may be made of a heat conducting material for cooling the contents of the vessel .
  • the lower heat conducting portion of the vessel may comprise heat conducting protrusions up into the vessel.
  • the carbon dioxide feed in the form of a pressurized cylinder may be located inside or outside the
  • the refrigerative apparatus may also comprise a valve housing for housing at least most of the valves of the plant.
  • the lower heat conducting portion of the vessel may be finned.
  • the lower heat conducting portion may have a pathway (s) which allows for the substantially upward flow or air so as increase heat transfer arising from natural convection.
  • the lower heat conducting portion may project out horizontally from the vertical projection of the vessel.
  • the bottom of the vessel as part of or above the lower heat conducting portion may be tapered.
  • the break tank may also be placed in the refrigerator door, preferably proximate to the vessel.
  • the upper portion of the break tank may be insulated.
  • a lower portion of the break tank near the bottom of the refrigerative apparatus maybe made of a heat conducting material for cooling the contents of the break tank.
  • a refrigerative apparatus comprising a vessel for storing carbonated water, wherein an upper portion of the vessel is insulated and a lower portion of the vessel near the bottom of the refrigerative apparatus is made of a heat conducting material for cooling the contents of the vessel.
  • a rotary pinch valve comprising a rotor, a stator, at least one rigid backing member and a plurality of movable members suitable for a plurality of flexible tubes.
  • the rotor may comprise a single essentially circular cam disk.
  • the rotor may comprise a plurality of essentially
  • cam spacer disk(s) separated from each other by cam spacer disk(s) and arranged as an essentially cylindrical whole.
  • the essentially cylindrical whole of the rotor may comprise separate laminar cam disks and spacer disks held together by fastener (s) or comprise an essentially continuous piece of rigid material.
  • the stator may comprise at least one stator pinch disk.
  • the stator may comprise a plurality of stator pinch disks separated from one another by a stator spacer disk(s) and arranged into an aligned whole.
  • the aligned whole of the stator may comprise separate laminar disks held together by fastener (s) or comprise an essentially continuous piece of rigid material.
  • a cam disk and its matching stator pinch disk may be in the same pinch plane.
  • a cam spacer disk and a stator spacer disk may be in the same plane.
  • the stator may be essentially cylindrical.
  • the stator may be truncated.
  • the stator may comprise at least one removable end plate so as to allow loading of the essentially cylindrical rotor.
  • the rotor and stator may have a means for being maintained in proper relative axial position.
  • the rotor when loaded may be maintained in proper axial position by the removable end plate.
  • At least one pinch slot may be located in a stator pinch disk.
  • the stator may have matching alignment holes at axially opposite ends of the stator for positioning the plurality of flexible tubes.
  • the alignment holes of the stator may be separated by alignment gaps.
  • a removable end plate may have alignment holes for positioning the flexible tubes separated by alignment
  • the plurality of flexible tubes may be aligned along the stator parallel to the axis of the rotary pinch valve .
  • a particular flexible tube may be aligned to pass over at least one pinch slot.
  • a pinch slot may comprise at least one spring compression base.
  • Pinch slots may be staggered around the circumference of the stator as well as along its axial length.
  • the at least one rigid backing member may comprise a single rigid piece suitable as a backing member for the plurality of flexible tubes.
  • the single rigid piece may be removable from or rotatable about the stator.
  • the at least one rigid backing member may comprise a plurality of individual rigid backing members, one for each pinch slot and its associated particular flexible tube.
  • An individual rigid backing member may be positioned over a particular pinch slot.
  • a rigid backing member may be rigidly attached to the stator.
  • An individual rigid backing member may be rigidly attached to the stator by a strut (s).
  • An individual rigid backing member may be rigidly attached to the stator by radial struts or substantially radial struts.
  • a particular individual rigid backing member may be removable from the radial struts or rotatable around them, so as to facilitate loading new flexible tubing and/or movable members .
  • a movable member may comprise a curved surface for mating with a cam disk and a pinching surface for pinching a particular flexible tube.
  • a movable member may comprise lateral
  • a movable member may comprise a pinching surface with rounded edges to avoid cutting the flexible tube.
  • a movable member may be positioned in any pinch slot of the stator
  • the rotary pinch valve may comprise a spring mechanism for acting on any particular movable member so as to ensure appropriate positioning of that particular movable member relative to its particular cam disk.
  • the spring mechanism may comprise a pair of springs acting on a spring compression base(s) associated with a pinch slot of the stator and lateral protrusions associated with a movable member.
  • the spring mechanism may comprise at least one short elastically deformable sleeve more resilient than a particular flexible tube which fits over a particular flexible tube in the vicinity of the pinch slot
  • the stator may comprise aligners to prevent lateral movement of any particular flexible tube and thereby allow the particular flexible tube to be pinched by a compact sized movable member the width of which is essentially the width of a pinched flexible tube.
  • Aligners for a particular flexible tube may be placed upstream or downstream of the pinch slot associated with a particular flexible tube and preferably at a distance where the particular flexible tube always exhibits an unpinched diameter and preferably as close to the pinch slot as possible.
  • Aligners may be incorporated into a stator spacer disk.
  • Aligners and radial or substantially radial struts for any particular flexible tube may be placed within a passage which is in axial alignment with an alignment gap in the end plate.
  • Radial or substantially radial struts associated with an individual rigid backing member may encompass at least three flexible tubes.
  • a pinched flexible tube may be axially adjacent to two adjacent flexible tubes that are not exhibiting a pinched diameter within that same pinch plane.
  • a pinch slot may extend laterally within the pinch plane across an axial passage associated with its associated flexible tube and also across both adjoining axial passages associated with the aligners of that flexible tube, preferably fully across both adjoining axial passages associated with the aligners of that flexible tube.
  • a flexible tube when pinched may spread its width into the axially aligned passage occupied by its aligners, preferably fully into the axially aligned passage occupied by its aligners.
  • Alignment gaps may be sized such that the pinched flexible tube and/or its associated extended movable member when in the pinched condition almost touch the unpinched flexible tubes either side of it within the same pinch plane. Any of the movable members or springs or flexible tubes may be loaded into the rotary pinch valve from an external position.
  • Movable members and/or springs may be loaded into the rotary pinch valve from an external position after the rotor has been placed in the stator and preferably with the end plate fixed.
  • the stator may comprise a plurality of indentations upstream or downstream of a pinch slot for the purpose of externally loading a plurality of movable members into their pinch slots.
  • the shape of the indentations may approximate the shape of the bottom of a movable member.
  • the stator may comprise a plurality of removable indentation filling pieces for filling the indentations after the plurality of movable members have been loaded into their pinch slots.
  • Movable members may be loaded into the stator
  • the movable member when slid under the individual rigid backing member so as to be substantially flush with it may have its lateral protrusions fit just under the spring compression base(s) .
  • a spring compression base (s) is not necessary but the lateral protrusions of the movable member may be maintained for alignment purposes and the movable member may be advanced into the stator by the distance taken by the flexible tube.
  • Movable members with or without their associated springs may be loaded into the stator from an external position by removal from the stator or rotation within the pinch plane or otherwise of a latching piece comprised of an individual rigid backing member, radial or substantially radial strut (s) and spring compression base(s) and subsequently latching the latching piece to the stator.
  • An individual rigid backing member as an individual piece may be removable from or rotatable about its associated radial or substantially radial strut (s)
  • the stator may be assembled about the rotor from a number a laminar stator pinch disks alternating with
  • At least one pinch valve may be located along the axial length of a flexible tube.
  • the rotary pinch valve may be programmable by providing a means to rotate and fix any cam disk relative to another cam disk.
  • a means to rotate any cam disk relative to another cam disk may comprise laminar cam disks and laminar cam spacer disks being detachable and having matching bolt holes or male and female accommodations at regular angular intervals.
  • the plurality of flexible tubes may be of different diameter.
  • a change of valve state as from open to closed and closed to open is abrupt, as from five to fifteen rotational degrees of the rotor.
  • the rotor may rotate within or about the stator with a close clearance.
  • the rotor may be driven by a rotating mechanism such as a geared electric motor or stepper motor.
  • cam disks may act on a particular movable member positioned within a pinch slot in the same pinch plane of the stator so as pinch a particular flexible tube against a rigid backing member so as to open and close the particular flexible tube in a desired manner .
  • Figure 1 is a schematic view of a plant for producing carbonated water
  • Figure 2 is a schematic view of a part of the plant of Figure 1 during a sorption step of a method for
  • Figure 3 is a schematic view of a part of the plant of Figure 1 during a pressure release step of the method for producing carbonated water using the plant of Figure 1;
  • Figure 4 is a schematic view of a part of the plant of Figure 1 during a vacuum purge step of the method for producing carbonated water using the plant of Figure 1
  • Figure 5 is a schematic view of a part of the plant of Figure 1 during a desorption step of the method for producing carbonated water using the plant of Figure 1;
  • Figure 6 is a schematic view of a plant according to another embodiment of the present invention for producing carbonated water
  • Figure 7 is a schematic view of a part of the plant of Figure 6 during a sorption step and a water pressurisation step of a method for producing carbonated water using the plant of Figure 6;
  • Figure 8 is a schematic view of a part of the plant of Figure 6 during the sorption step and a fluid displacement vessel filling step of the method for producing carbonated water using the plant of Figure 6
  • Figure 9 is a schematic view of a part of the plant of Figure 6 during the sorption step and a venting step of the method for producing carbonated water using the plant of Figure 6;
  • Figure 10 is a schematic view of a part of the plant of Figure 6 during a pressure release step of the method for producing carbonated water using the plant of Figure 6 ;
  • Figure 11 is a schematic view of a part of the plant of Figure 6 during a vacuum purge step of the method for producing carbonated water using the plant of Figure 6;
  • Figure 12 is a schematic view of a part of the
  • Figure 13 is a diagrammatic view of a pump of the plant of Figure 6 according to an embodiment of the present invention.
  • Figure 14 is a diagrammatic view of a combined compressor and pump for the plant of Figure 6 according to another embodiment of the present invention
  • Figure 15 is a schematic view of a plant according to a further embodiment of the present invention for producing carbonated water
  • Figure 16 is a schematic view of a plant according to yet another embodiment of the present invention for producing carbonated water
  • Figure 17 is a schematic view of a soft drink plant for the production and dispensing of flavoured soft drinks
  • Figure 18 is an electric circuit for use in controlling operation of the plant of Figure 1;
  • Figure 19 is a schematic view of a plant for producing and dispensing carbonated water according to an embodiment of the present invention.
  • Figure 20 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention.
  • Figure 21 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention
  • Figure 22 is a schematic view of a plant for producing and dispensing carbonated water according to yet another embodiment of the present invention.
  • Figures 23 and 24 are diagrammatic views of the plant according to embodiments of the present invention incorporated into a refrigerator.
  • Figure 25 is a schematic view of a plant for producing and dispensing carbonated water according to
  • Figure 26 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention
  • Figure 27 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention.
  • Figure 28 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention.
  • Figure 29 is a schematic view of a plant for producing and dispensing carbonated water according to another embodiment of the present invention.
  • Figure 30 is a schematic view of a portion of a plant for recovering carbon dioxide from vented gases according to an embodiment of the present invention
  • Figure 31 is a schematic view of a portion of a plant for recovering carbon dioxide from vented gases according to an embodiment of the present invention
  • Figure 32 is a schematic view of a further portion of a plant for recovering carbon dioxide from vented gases according to a further embodiment of the present invention
  • Figure 33 is a schematic view of a further portion of a plant for recovering carbon dioxide from vented gases according to a further embodiment of the present invention.
  • Figures 34 and 35 are side and top views of a vessel of the plant according to embodiments of the present invention.
  • Figure 36 is an overall view of the rotary pinch valve but showing the apparatus to pinch but one flexible tube;
  • Figure 37 is an exploded view of the curved surface of the rotary pinch valve stator indicting pinch slots staggered around the circumference as well along the axial length of the stator;
  • Figure 38 is an overall view of the essentially cylindrical rotor comprised of alternating cam disks and cam spacer disks;
  • Figure 39 shows an example of the cross section of two possible cam disks of the rotor
  • Figure 40 is a view through a particular pinch plane outlining the pinch mechanism
  • Figure 41 is a view of a cross section of the stator showing aligners for flexible tube positioning
  • Figure 42 is a view of a movable member ready to be loaded via an indentation into a pinch slot of the stator in association with springs;
  • Figure 43 is a view of a movable member loaded via an indentation into a pinch slot of the stator in association with springs;
  • Figure 44 is a view of a movable member ready to be loaded via an indentation into a pinch slot of the stator with no pinch slot springs;
  • Figure 45 is a view of a movable member loaded via an indentation into a pinch slot of the stator with no pinch slot springs;
  • Figure 46 is a partially exploded view of a rigid backing member as an individual piece rotatable about a modified radial strut; and Figure 47 is a view of a particular cam disk of the rotor comprising bolt holes so as to allow programming of the rotary pinch valve .
  • Embodiments of the present invention relate to a method for producing carbonated water which comprises the general steps of manufacturing a gas containing carbon dioxide on site and in situ mixing the carbon dioxide with water to produce carbonated water.
  • the method according to embodiments of the present invention further does away with the need to use carbon dioxide cylinders in refrigerator applications, which is also a significant advantage both in terms of ease of use and operational costs.
  • the gas containing carbon dioxide may be manufactured by any suitable physical or chemical methods such as extraction from a gas such as contaminated air or as a product (waste or desired) from a chemical reaction for example.
  • a gas such as contaminated air or as a product (waste or desired) from a chemical reaction for example.
  • Common chemical reactions which produce carbon dioxide include fermentation, steam reformation of hydrocarbons and combustion reactions .
  • the gas containing carbon dioxide Before mixing the manufactured carbon dioxide with the water to produce carbonated water, the gas containing carbon dioxide will usually require purification. This may occur by any suitable mechanism, such as filtration, swing sorption (such as under a thermal, pressure, microwave or electrical swing (such as that disclosed in US 5972077) or any combination thereof) , scrubbing or de-misting for example.
  • the type of purification mechanism may be dependent on how the gas containing carbon dioxide was derived and thus what impurities it has.
  • the carbon dioxide may also require pressurisation, in particular after the step of purification. However, in some embodiments the carbon dioxide may be at sufficient pressure after purification (and hence not require further pressurisation) or may be pressurised during purification.
  • the water which the carbon dioxide is mixed with may require pressurisation. This may or may not occur simultaneously with the step of mixing the carbon dioxide with the water.
  • the resulting carbonated water, produced according to the method of this invention has a conventionally acceptable concentration of carbon dioxide of approximately four volumes (at atmospheric
  • FIG. 1 shows a plant 100 for producing carbonated water according to an embodiment of the present invention which is particularly suitable for use in relation to a refrigerator.
  • the gas containing carbon dioxide is manufactured by combusting a hydrocarbon fuel, preferably natural gas which can be readily drawn from the reticulated supply in most urban and commercial areas.
  • a hydrocarbon fuel preferably natural gas which can be readily drawn from the reticulated supply in most urban and commercial areas.
  • the water which the carbon dioxide manufactured in the plant 100 is mixed with, is typically sourced from mains water.
  • the plant 100 is suitable for installation in relation to a refrigerator because its two major input streams can be supplied by connecting the plant 100 to the reticulated gas and water supplies available in many homes and businesses.
  • Such water may undergo treatment such as by a carbon filter or an exchange resin before introduction to the plant 100.
  • the plant 100 comprises a combustion unit 101 having cooling jackets 102, 103, a first liquid ring compressor stage 104, a second liquid ring compressor stage 105, a sorber/desorber 106, a cool water reservoir 107 and a product drawdown vessel 108.
  • the combustion unit 101 is for combusting natural gas to manufacture carbon dioxide and comprises a burner 117 firing into a firebox 118 (which is insulated).
  • the jackets 102, 103 are arranged relative to the firebox 118 so as to cool the firebox 118.
  • the first jacket 102 is also for steam generation, the purpose of which will become apparent further on in the specification.
  • the sorber/desorber 106 is for purifying the
  • the sorbent in the sorber/desorber 106 is a non-toxic sorbent, so that the plant 100 may be safely used in a refrigerator (in particular in a domestic refrigerator) without any risk of toxic contamination of the carbonated water product .
  • the sorbent may be an aqueous based liquid sorbent, however for the plant 100 shown in Figures 1-5, it is preferably solid and substantially non-miscible with water. This is because a solid sorbent is less likely to cause toxic contamination of the produced carbonated water by spillage or leakage for example.
  • a solid sorbent avoids the further problem which may occur if using a liquid sorbent of possible rupture of the pressurised plant equipment associated with the liquid sorbent. Such ruptures could lead to leaks of toxic chemicals.
  • the solid sorbent provides for easier control of the water balance in the sorber/desorber 106, because the water readily disengages from the solid sorbent.
  • use of liquid sorbent in the sorber/desorber 106 is possible in the present invention.
  • sorbent with good selectivity and stability in an environment with water condensation is a weak base anion exchange resin such as Rohm and Haas IRA
  • Porous substrates with amine function compounds "immobilised” on them by chemical or physical means can have superior sorption capacities, but condensation may leach such amine compounds from the substrate.
  • Other sorbents may be subject to hydrolysis.
  • gaseous feed to the sorber/desorber 106 will preferably need to be dewatered. This may effectively be achieved through refrigeration of compressed gaseous feed, prior to entering the sorber/desorber 106 but disadvantageously involves another processing unit and associated space.
  • the first and second liquid ring compressor stages 104, 105 are for providing the required pumping and compression in the plant 100.
  • the liquid ring compressor stages 104, 105 simultaneously handle liquid and gas working fluids, they can potentially each act as a compressor and a pump.
  • the liquid ring compressor stages 104, 105 are compact, rotary, low maintenance, quiet and can perform a scrubbing function (and therefore assist in the removal of impurities from the carbon dioxide) . It is to be understood that in other embodiments not shown in the Figures, that the plant 100 may comprise more than two liquid ring compressor stages.
  • the first liquid ring compressor stage 104 comprises a first top level float separator 109, a first liquid ring compressor 110 and a first separator 111.
  • the second liquid ring compressor stage 105 comprises a second top level float separator 112, a second liquid ring compressor 113, a bottom level float separator 114 and a second separator 115.
  • the first and second liquid ring compressor stages 104, 105 may each comprise more than one individual compressor. Individual compressors of the plant 100 may be driven by the same or separate motors . The purpose of the various components of
  • liquid ring compressor stages 104, 105 will become apparent from the description of the operation of the plant 100 below.
  • the cool water reservoir 107 is for providing a buffer between the mains water supply and any carbon dioxide or pressurised water in the plant 100 so as to mitigate against backflow and contamination of the mains water.
  • the cool water reservoir 107 has a float valve 116 which is connected to the mains water supply, for maintaining the water level in the cool water reservoir
  • the cool water reservoir 107 may thus also act as an inventory for the water in the plant 100.
  • the product drawdown vessel 108 is for storing the carbonated water produced by the plant 100 and for consequently dispensing the carbonated water therefrom.
  • the product drawdown vessel 108 is designed to have a significant freeboard of gaseous space to act as a propellant for dispensing even when the product drawdown vessel 108 is nominally full. This means that it is unnecessary for the plant 100 to have a dispensing pump.
  • the product drawdown vessel 108 has an automatic drain float valve 119 for preventing the carbonated water from being dispensed from the product drawdown vessel 108 when the carbonated water is at a low level in the vessel 108. This prevents the product drawdown vessel 108 from emptying completely of carbonated water which could result in air ingress to the product drawdown vessel 108. Such air ingress is undesirable as it will interfere with the carbonation process on subsequent cycles.
  • the plant 100 operates according to a batch process, involving the following four general operational steps :
  • the plant 100 also comprises a valve system 120 for directing the fluid flow during the operation of the plant 100 at the different operation steps.
  • the valve system 120 comprises a plurality of valves (marked 1-17) .
  • the valve system 120 may comprise a rotary valve, preferably a rotary pinch valve. It may be driven by a speed reduction unit off the compressor motor. In other embodiments, the valve system 120 comprises a three position valve, preferably a pinch or spool valve relying on the pressures of vacuum, atmospheric pressure and sorber/desorber relief pressure for positioning.
  • a feed of natural gas 121 comprising mostly methane, is provided to the burner 117 of the combustion unit 101 where it is combusted with air according to the following reaction:
  • the natural gas is preferably combusted in approximately 20% excess air to produce a stream of approximately 10% carbon dioxide (on a water free basis) .
  • This stream exits the firebox 118 and is cooled as it passes through heat exchange tubing 122.
  • the burner 117 may be any suitable burner that
  • the burner 117 may be an atmospheric burner or be contained in a firebox which is exposed to atmosphere by one or more flame arrestors. The burner 117 may be also totally enclosed in a firebox and rely on induced draft. In a particular embodiment, the burner 117 is a high velocity burner. The burner has a small capacity of up to and around 1 MJ/hr, which is commensurate with the flow rate of combustion gases to the plant 100.
  • the burner 117 could be operated in several different ways, including the burner 117 being on continuously, ignition of the burner 117 by a continuous pilot flame or ignition of the burner 117 on start-up of operation of the plant 100. Should a pilot flame smaller than the process flame of the burner be utilised, the process flame could reach its full process size via appropriate poppet valving in the valve system 120.
  • the burner 117 may also comprise a flame safeguard device.
  • the flame safeguard device is for shutting off the natural gas supply should the burner flame be extinguished, thereby preventing the possible dangerous accumulation of a combustible gas.
  • the flame safeguard device may comprise for example a thermoelectric valve or a solenoid valve. In the embodiment where the flame safeguard device comprises a solenoid valve, it is controlled by a flame switch that may be incorporated into an integrated flame sensing electronic module.
  • the process of igniting the burner 117 involves opening the flame safeguard device in the form of a solenoid valve or thermo-electric valve for a short period of time, in conjunction with a source of ignition and starting a timing device.
  • Successful ignition of the burner 117 within a "trial for ignition" designed time period results in the valve of the flame safeguard device staying open, whereas unsuccessful ignition results in the valve
  • the burner 117 may also comprise an alarm indication for signalling an unsuccessful ignition as this may be indicative that the burner 117 is not functioning properly.
  • a thermoelectric valve it is possible to use the intrinsic capabilities of the plant 100 to open the thermoelectric valve and thereby ignite the flame.
  • the thermoelectric valve may be opened during the trial for ignition period by depressing the mechanical plunger of the thermoelectric valve utilising either start up compression gases or a cam operating off a rotating member associated with (a motor of) the plant 100.
  • thermoelectric valve In both instances it is necessary to ensure that should the motor stop in the trial for ignition period that no undue combustible gas escapes to atmosphere. Where compression gases are utilised to open the thermoelectric valve this may involve a permeable diaphragm actuator which gradually loses pressure on stoppage of the motor thereby closing the thermoelectric valve .
  • thermoelectric valve a reservoir of gas may be positioned between the thermoelectric valve gas inlet and a gas valve in the valving system 120.
  • This gas valve would be open at rest thereby pressurising the reservoir of gas to line pressure. However, it would close on start up of the plant 100 whereafter the cam would depress the plunger of the thermoelectric valve to the open position allowing combustible gas from the reservoir to be ignited.
  • the reservoir of gas would have sufficient capacity given the burning rate to maintain a flame for the duration of the trial for ignition period together with the time for the gas valve in the valving system 120 to reopen thereby maintaining a flame caused by a successful ignition.
  • the reservoir of gas will be depleted thereby extinguishing the flame.
  • the closed gas valve of the valving system 120 would prevent combustible gas flowing to atmosphere.
  • the burner may also comprise a re-ignition device which acts to re-ignite the flame before the flame safeguard valve closes. It is also noted that should the burner flame fail and unsuccessful re-ignition occur, that it may be preferable that once started, the operation of a cycle of the plant 100 goes to completion. It may also be preferable that the flame safeguard valve close should there be a power cut.
  • any of the combustion unit, burner, flame safeguard and ignition and re-ignition devices may also be part of another appliance such as a gas stove or a gas hot water system.
  • the first liquid ring compressor stage 104 acts as a compressor of the combustion products.
  • Valve 1 is opened and valve 2 closed to allow the cooled combustion products to flow into the first top float separator 109 and then into the suction of the first liquid ring compressor 110.
  • the first liquid ring compressor 110 compresses the gas containing carbon dioxide which then exits the first liquid ring compressor 110 into the first separator 111.
  • the condensate water formed in the combustion reaction is the condensate water formed in the combustion reaction. Because of the nature of a liquid ring compressor some liquid is ejected from the compressor 110 into the first separator 111. The function of the first separator 111 is to therefore capture at least some of this ejected liquid and return it to the suction side of the first liquid ring compressor 110 via the first top level float separator 109. This is preferably done with cooling of the ejected liquid between the first separator
  • first liquid ring compressor 110 may be done by flowing it through heat exchange tubing in the cool water reservoir 107 (as shown in Figure 2) . This helps in ejecting at least some of the heat of compression from the first liquid ring compressor 110. This continues for the rest of the operational cycle of the plant 100 and as a result enhances the performance of the first liquid ring compressor 110 over the entire cycle. In another embodiment, it may be desirable, during sorption only, to direct this flow to an alternate source of cooling such as air cooling either within the refrigeration space or outside it. This avoids placing a heat load on the cool water reservoir and gives flexibility in achieving proper humidity from the first separator 111.
  • alternate source of cooling such as air cooling either within the refrigeration space or outside it. This avoids placing a heat load on the cool water reservoir and gives flexibility in achieving proper humidity from the first separator 111.
  • a high level float valve 123 in the first top level float separator 109 prevents the float separator 109 from over flowing with liquid by closing off the ejected liquid inlet from the first separator 111 when the liquid level becomes to high in the first top level float separator 109. It is noted, in this regard that the first top level float separator 109 and the first separator 111 are designed to have a combined volume which is sufficient to hold the volume of condensate produced during a single operational cycle of the plant 100.
  • the compressed gas containing carbon dioxide exits the first separator 111 and flows via valve 3 (with valves 2, 13 and 14 closed) into the sorber/desorber 106 for sorption of the carbon dioxide in the sorbent under raised pressure.
  • the sorbent is a weak base anion exchanger resin (as described above) then it requires a moist environment in order to function most efficiently. This is suitably provided by the humidity in the gas stream exiting the first separator 111 but in another embodiment may be provided by process condensate exiting the same first separator 111.
  • the gas, substantially depleted of carbon dioxide exits the sorber/desorber 106 through a relief valve 124 and thence to atmosphere via the second jacket
  • the relief valve 124 is located towards the top of the sorber/desorber 106 so as to act against possible particulate contamination of the relief valve 124 from the friable sorbent resin.
  • the relief valve 124 preferably has a design relief pressure of approximately 50 to 75psig.
  • the second liquid ring compressor stage 105 acts as a cooling liquid pump to cool the sorber/desorber 106. Sorption of the carbon dioxide is enhanced by this cooling. Water is drawn from the cool water reservoir 107 via valve 5 and the second top level float separator 112 into the second liquid ring compressor 113, which then pumps the water via valve 7 through heat exchanger tubes in the sorber/desorber 106. The water is returned to the cool water reservoir 107 from the sorber/desorber 106 via valve 12.
  • the first jacket 102 As soon as the first jacket 102 has been filled, it should be immediately drained (by opening valve 17) to the cool water reservoir 107. This flow of cooling water through the first jacket 102 also ensures that scale does not build up on the surface of the jacket, particularly where mains water is being used.
  • the liquid contents of the heat exchanger tubing in the sorber/desorber 106 which have been left there from previous operational cycles of the plant 100 are purged into the first jacket 102 using start-up purge gases from the liquid ring compressors 110, 113 (followed by immediate drainage) to provide initial cooling of the firebox 118.
  • valve 9 which directs gas through the second jacket 103 (to cool the firebox 118) .
  • the outlet from the sorber/desorber 106 through which pressure release gas is directed is preferably located slightly above the bottom of the sorber/desorber 106 so as to leave a well of condensate water at the bottom of the sorber/desorber 106.
  • the well of condensate is for acting against the ion exchange resin drying out when not in use with consequent loss in capacity.
  • the vacuum purge step extracts a substantial amount of the extraneous gases from the sorber/desorber 106 which comprises mostly oxygen and nitrogen, particularly nitrogen by applying a low pressure on the sorber/desorber 106 using the liquid ring compressor stages 104, 105. The reason for doing this is to remove as much of the nitrogen as possible, as it interferes with the subsequent carbonation process.
  • the vacuum purge occurs by opening valves 2 and 14 with valve 1 closed and vacuuming the gas out of the sorber/desorber 106 through the first liquid ring compressor stage 104 and then through the second liquid ring compressor stage 105.
  • An optional recycle of the gas exiting the first separator 111 of the first liquid ring compressor stage 104 to the gas flow into the first top float separator 109 is provided through valve 3.
  • a similar optional recycle may be provided across the second liquid ring compressor stage 105 through valve 15. This recycling can improve the sensitivity of the valve system 120 (which may be slow moving) in regard to the appropriate vacuum from which to switch from vacuum purge to desorption. It can also act to increase the recovery of carbon dioxide from the gas being vacuum purged by dissolution of carbon
  • the vacuum purged gases may be subsequently purged directly to atmosphere. However, in an embodiment they are purged from the top of the bottom level float separator 114 via valve 11 through the heat exchanger tubes of the sorber/desorber 106 so as to push the residual liquid in the heat exchanger tubes (from the sorption stage) up into the first jacket 102 of the combustion unit 101 (through valve 6) in preparation for the desorption stage.
  • the purged gases and any overflow of water from the first jacket 102 is directed back to the cool water reservoir 107 through valve 10.
  • the second liquid compressor stage 105 acting as a pump pumps water into the jacket 102 in preparation for desorption. This particular embodiment using the second compressor stage 105 as a pump, if performed slightly earlier in the cycle could also be used to cool the combustion unit 101 immediately after it ceased to be cooled by relief gases from the sorber/desorber 106.
  • the vacuum purge gases first flow under pressure through a relief valve on the top of bottom level float separator 114 and then via valve 11 to atmosphere as above.
  • the vacuum purge gases are directed through a second sorber/desorber .
  • This second sorber/desorber is smaller than the first mentioned sorber/desorber 106 but contains a suitable similar sorbent .
  • the secondary sorber/desorber is equipped with a relief valve through which the vacuum purge gases are directed from the sorber/desorber 106 to atmosphere. It is possible for the relief valve to be "shared" between the two sorber/desorbers by appropriate valving in the valving system 120.
  • the second sorber/desorber may or may not be exposed to a pressure release step. It is not necessary to expose the second sorber/desorber to a vacuum purge step.
  • the second sorber/desorber has no internal cooling/heating tubing similar to that in sorber/desorber 106, though it may have such heat exchange tubing. However, it may be heated and cooled by physical contact with sorber/desorber 106.
  • carbon dioxide values are recovered in the second sorber/desorber with nitrogen enriched gases flowing to atmosphere through the relief valve on the second sorber/desorber. These relief gases may be similarly utilised for further uses such as for pumping water into the jacket 102 of the firebox as explained elsewhere herein.
  • a pressure release step is then enacted on the second sorber/desorber.
  • vacuum is applied equally to both sorber/desorbers in parallel so as to produce product gas .
  • the second sorber/desorber if it uses a similar ion exchange resin to the sorber/desorber 106 also does not dry out. This may be achieved by directing pressure release gases from the sorber/desorber 106 through the second sorber/desorber to atmosphere, preferably so as to leave a well of condensate in the bottom of the second sorber/desorber.
  • the plant 100 may comprise a vacuum valve to effect this change from vacuum purge to desorption.
  • the vacuum valve may take a number of forms .
  • the vacuum valve may be a vacuum actuated three way valve with the actuator being exposed to the compressor stage 104 suction but with the three way valve placed on the compressor stage 104 or 105 discharge so as to switch compressor discharge flow from vacuum purge to desorption at a designed low pressure in the sorber/desorber 106.
  • the vacuum valve may comprise a pair of parallel tubes each valved separately in the valve system apparatus 120, and each feeding into the suction (inlet) side of first liquid ring compressor stage 104. Additionally, one of these lines is designed to close at the designed low pressure by an additional valve in the line. This valve may be a check valve with an appropriately set cracking pressure or a collapsible tube set to collapse at the designed low pressure.
  • vacuum purge flow is through the dual valved suction line with the parallel suction line closed.
  • valve 11 closes and then valve 4 opens, whereafter the parallel suction line is opened by a valve in the valving system 120 allowing the flow of desorption gases.
  • the vacuum purge step and pressure release step occur in the same flow scheme, with the pressure release gases flowing to atmosphere via either or both compressor stages 104, 105, followed immediately by the vacuum purge gases along the same flow
  • This embodiment minimises valve openings and closures, but may cause an undue rush of gases through the compressor during pressure release.
  • Valves 2 and 14 remain open and the first and second liquid ring compressor stages 104, 105 continue to apply a vacuum on the sorber/desorber 106.
  • the reduced pressure applied to the sorber/desorber 106 causes the carbon dioxide to desorb from the sorbent. Desorption is aided by the application of heat on the sorber/desorber 106 (so as to effect a thermal swing in addition to the pressure swing) . This may be achieved by any suitable source of energy, including electrical energy or the use of waste heat from the refrigerator which the plant 100 is associated with. However, for the plant 100 shown in Figures 1 to 5, the heat is applied to the sorber/desorber 106 by passing steam through the heat transfer tubes of the sorber/desorber 106.
  • These heat transfer tubes may be finned and/or blackened.
  • the steam is generated using the combustion unit 101 to heat the water which was pushed up into the first jacket 102 during the vacuum purge stage (discussed above) .
  • the water is vaporised to steam and flows to the heat transfer tubes of the sorber/desorber 106 through valve 8 before returning to the cool water reservoir 107 via valve 12.
  • the flue gases from the combustion unit 101 are directed to atmosphere during desorption through valve 16.
  • the valve 16 is preferably located above the firebox 118 of the combustion unit 101 so as to facilitate natural draft.
  • the valve 16 may be a pinch valve, in which case it comprises a high temperature resistant flexible elastomer such as silicone.
  • the thermodynamics of the firebox 118 must be designed so that
  • the pinch valve 16 is not exposed to an overly high thermal load which may cause it to fail.
  • This silicone tubing may, for example, be connected to ambient heat loss metal tubing, which metal tubing is itself connected at its other end to the hot firebox takeoff via a high temperature insulating material such as PTFE.
  • the valve 16 may be a poppet valve of any suitable material.
  • the volumetric flow rate of combustion gas produced in the combustion unit 101 should exceed the volumetric flow rate into the first liquid ring compressor stage 104 to act against air being drawn in through the flue gas vent and diluting the feed to the first liquid ring compressor stage 104. It is noted that this problem is at least partially mitigated in the embodiments where the valve 16 is present on the flue gas vent. It is also noted that during desorption the heat available for steam generation is not negatively influenced by heat flow to the heat exchange tubing 122. This is achieved by the positive cracking pressure of the check valve 133 together with a portion of the line being of an insulating material such as PTFE.
  • the desorbed gases are drawn from the first separator 111 by the second liquid ring compressor 113 into the second top level float separator 112 through valve 14.
  • the second liquid ring compressor 113 also draws in water from the cool water reservoir 107 through valve 5 to the second top level float separator 112 to mix with the carbon dioxide, ie. to carbonate the water.
  • the second liquid ring compressor 113 is designed to have a suction pressure which is sufficient for this purpose, probably below atmospheric.
  • the second liquid ring compressor stage 105 thus acts as a compressor to compress
  • the desorbed gases entering the second liquid ring compressor stage 105 are generally not 100% carbon dioxide, and may still contain some extraneous gases, particularly nitrogen.
  • the bottom level float separator 114 provides a further polishing or scrubbing of the desorbed gases.
  • the float valve 131 of the bottom level float separator 114 closes the flow of liquid to the second separator 115 at a design low level in the bottom level float separator 114. This provides a significant holding time for the liquid in the bottom level float separator 114, during which the extraneous gases, in particular the nitrogen gas, is at least partially separated from the carbon dioxide by virtue of the preferential dissolution of the carbon dioxide in the water over nitrogen.
  • the nitrogen is thus trapped mainly in (and later vented from as described below) the vapour space of the bottom level float separator 114, whilst the carbon dioxide mainly exits the bottom level float separator 114 with the water through the float valve 131 at the bottom of the bottom level float separator 114.
  • the circulatory fluid for heating and cooling the sorber/desorber 106 is the condensate in the first liquid ring compressor stage 104 rather than the water from the cool water reservoir 107.
  • the first liquid ring compressor stage 104 either from a take off on the casing of the liquid ring compressor 110 or from the discharge of compressor 110, pumps condensate through heat exchange tubes in a cooling medium within the refrigerator and then through the heat exchange tubes in the sorber/desorber 106 before returning to the liquid ring compressor stage 104 suction.
  • This pumping action or the vacuum purge gases may also be used to push condensate from the heat exchange tubes in the sorber/desorber 106 into the jacket 102 of the combustion unit 101 for steam generation whereafter it is
  • the above mentioned cooling medium within the refrigerator may be a reservoir of cyclic defrost water from the refrigerator, the contents of which in other embodiments may also be used as a circulatory fluid for heating and cooling the sorber/desorber 106.
  • the plant 100 also comprises a PDV fill control mechanism 126 for controlling filling of the product drawdown vessel 108.
  • the product drawdown vessel 108 may require gas and/or liquid filling under different conditions, such as at a low liquid level after carbonated water has been dispensed from the product drawdown vessel 108 or at a low pressure level due to some loss of pressure in the vessel 108.
  • the PDV fill control mechanism 126 therefore comprises a low level switch 127 and a low pressure switch 128 on the product drawdown vessel 108.
  • the low level switch 127 activates filling of the product drawdown vessel 108 with carbonated water upon detection of a design low liquid level.
  • the low pressure switch 128 activates input of pressurised carbon dioxide gas to the product drawdown vessel 108 upon detection of a design low pressure level.
  • the PDV fill control mechanism In activating filling of the product drawdown vessel 108 with either carbonated water or gas, the PDV fill control mechanism thus initiates (and controls) start-up of operation of the plant 100.
  • the low pressure switch 128 is separated from the vapour space in the product drawdown vessel 108 by a membrane 130, so as to act against a low pressure start-up being activated by momentary dispensing of carbonated water from the vessel 108 as opposed to a genuine pressure loss from the vessel 108.
  • the PDV fill control mechanism also comprises a controllable valve 129 (which is preferably a solenoid valve) on the liquid recycle between the second separator 115 and the second top level float separator 112. On a low
  • the controllable valve 129 is closed so that no liquid is recycled from the second separator 115 to the second top level float separator 112.
  • the second separator 115 fills with carbonated water to a designed height until it overflows into the product drawdown vessel 108 through valve 4. This flow of carbonated water into the vapour space of the product drawdown vessel 108 may be over an extended surface or occur as a spray.
  • the controllable valve 129 is open allowing recycling of the liquid from the second separator 115 to the second top level float separator 112.
  • the take-off from the separator 115 to the product drawdown vessel 108 is much higher than the recycle outlet, which causes the liquid to preferentially recycle to the second top level float separator 112.
  • controllable valve 129 may be a three way valve thereby eliminating the need for check valve 134.
  • the recycle line from the bottom of the second separator 115 to the bottom of the second top level float separator 112 is eliminated with inlet water into the bottom of the second top level float separator 112, for a low pressure start, being via a three way controllable valve from a point below the water level in the product drawdown vessel 108.
  • recycling of water occurs through the product drawdown vessel 108 for a low pressure start and the second separator 115 may not be necessary.
  • the PDV fill control mechanism also comprises a low level start-up mechanism, which acts against the motor being sent a mixed alternating start-up signal, due to any surface turbulence caused by carbonated water being withdrawn.
  • the start-up could be initiated at the first indication of a low level, which latches in the start-up signal for a cycle, for example, by electrical circuitry.
  • a possible electrical circuit which could be used to control operation of the plant 100 is shown in Figure 18.
  • the electrical circuit comprises a latching relay, or a normal relay where a first pole acts as a "hold in" contact. Consequently, the first indication of a low level in the product drawdown vessel will start the cycle.
  • the electrical circuit is also used to control the burner 117, in particular ignition of the burner 117 and the burner's flame safeguard device.
  • the PDV fill control mechanism may also comprise a processor (in the form of a microchip for example) for monitoring unacceptable gas leakage from the product drawdown vessel 108 by calculating the ratio of low pressure starts to low level starts and comparing it to an acceptable ratio.
  • a processor in the form of a microchip for example
  • the plant 100 may undergo a venting step and a drainage step to remove extraneous gases and liquids. This may involve draining the condensate water from the first separator 111 above a designed level through valve 13 to the evaporator tray 125. A similar drain, not shown in Figure 1 may also be performed on the second separator 115. Venting of extraneous gases may also be undertaken to avoid any build up in the plant 100 over repeated cycles due to the fact that the desorption gases are not 100% carbon dioxide. This venting may occur from the bottom level float separator 114 through valves 11 and 12 or through valves 11, 8, 10. It is noted that the main function of the bottom float separator 114 is to trap these gases, which contain mostly nitrogen (which is relatively insoluble in
  • venting of extraneous gases from the bottom float separator 114 may occur during the sorption stage (of a subsequent cycle) .
  • the venting of extraneous gases is also performed by a relief valve 132 on the product drawdown vessel 108.
  • This relief valve 132 has a set pressure in the vicinity of 2 bar or above. Venting by this embodiment is mostly during the desorption step. Venting may be carried out exclusively in this way, in which case it is not necessary for the plant 100 to have the bottom level float separator 114. However, this embodiment is likely to incur a higher loss of carbon dioxide than if the venting of extraneous gases is performed using the bottom level float separator 114 in addition to venting from the product drawdown vessel 108.
  • the relief gases from the relief valve 132 may however be bubbled through the cool water reservoir 107 (not shown in Figure 1) so as to increase recovery of carbon dioxide.
  • the plant 100 may initiate another operational cycle if required, or may stay at rest waiting for a signal from the PDV fill control mechanism 126 to start-up operation of the plant 100.
  • a first check valve 133 acts to prevent liquid loss from the plant 100, particularly from the first liquid ring compression stage 104. ⁇ lthough, if any liquid is lost, this could be made up with process condensate or cyclic defrost from the refrigerator with which the plant 100 is associated. It may also be desirable to fill the sorbent bed of the sorber/desorber 106 with combustion gases so as to minimise oxidative degradation of the sorbent whilst the plant 100 is at rest.
  • valves 1 and 2 are pinch valves, that it is preferable that they should remain open in the rest position, especially valve 2. This is to avoid any compression set in the flexible tube which
  • valves 1, 2 and 3 are open in the rest position with valve 2 closing on start up.
  • the plant 100 also comprises a back flow mitigation system 140 for mitigating any backflow of mains water into the sorber/desorber 106.
  • the backflow mitigation system 140 is designed to mitigate backflow even when there is no power supplied to the plant 100. This is particularly important in the event of a power cut to the plant 100 during some part of the operational cycle described above when valves are opened. With no power supply, the compressors 110,113 will cease to operate and the plant 100 is therefore susceptible to mains water undesirably flowing into the sorber/desorber 106.
  • the backflow mitigation system 140 firstly comprises the use of process condensate derived from the combustion reaction as the liquid in the first liquid ring compressor stage 104.
  • the backflow mitigation system 140 also comprises a second check valve 141 located between the sorber/desorber 106 and the cool water reservoir 107.
  • the second check valve 141 at all times only allows fluid flow in one direction, specifically fluid flow away from the sorber/desorber 106.
  • the second check valve 141 is preferably located between the second liquid ring compression stage 105, which uses mains water, and the first liquid ring compression stage 104, which does not.
  • the backflow mitigation system 140 also comprises demisters 142 in the first and second top level float
  • the float valve 143 in the second top level float separator 112 also forms part of the backflow mitigation system 140 by acting against the second top level float separator 112 from overfilling with water and backflowing.
  • the plant 100 also comprises a water balance system for balancing the water produced in the combustion reaction by disposing water from the plant.
  • Water from the combustion reaction is condensed in the first liquid compressor stage 104 and also in the sorber/desorber 106 and requires balancing to prevent overflow and/or excessive water accumulation in these units.
  • the water balance system comprises an evaporator tray 125 on which the disposed water may be evaporated.
  • Evaporation on the evaporator tray 125 may occur using the waste heat of the refrigerator in relation to which the plant 100 is associated. Evaporation may also occur using other process heat such as from the jackets 102, 103 of the combustion unit 101 or ambient thermal energy.
  • the disposed water includes accumulated water within the first liquid ring compressor stage 104 which is directed to the evaporator tray 125 at a suitable time in the operation of the plant 100, most preferably at the end of a cycle, by opening valve 13 on the first separator 111.
  • the disposed water also includes accumulated water within the sorber/desorber 106 which is directed, during the pressure release step to the second jacket 103 of the combustion unit 101, and any remaining water after evaporation in the second jacket 103 is directed to the evaporator tray 125.
  • the disposed water is collected rather than sent to an evaporator tray, either for physical disposal or incorporation into the carbonated water product.
  • the plant could comprise a compressor for compressing gases and at least one pump for pumping and pressurising of liquids. If the plant only comprised one pump, then it may be required to provide the high pressure function of pressurising mains water for mixing with the carbon dioxide as well as the low pressure function of circulating the cooling water through the sorber/desorber 106 during desorption. In another embodiment, the plant may comprise two pumps, one for carrying out each of these functions . The advantage of separate flow streams for water and gases is that there would be less potential for mains water contamination of the sorbent bed in the sorber/desorber.
  • the plant may comprise only one pump, which is a low pressure pump for circulating the cooling and heating water, with the compressor instead of a mechanical pump providing the high pressure function of pressurising the mains water into the plant by using compressed gas from the compressor to act as a fluid displacement pump.
  • a plant 200 for producing carbonated water according to another embodiment of the present invention, and having this particular variation is shown in Figures 6 to 12. Although this plant 200 would be more bulky than the plant 100 outlined in Figures 1 to 5, it would advantageously be of low cost and maintenance.
  • the plant 200 is also particularly suitable for use in relation to a refrigerator. Similar features of the plant 200 to the plant 100 shown in Figures 1 to 5 have been designated with the same reference number, but have been prefixed with the numeral 2 instead of 1.
  • the plant 200 comprises a combustion unit 201, a sorber/desorber 206, a cool water reservoir 207 and a product drawdown vessel 208.
  • the plant 200 also comprises a compressor 250, a pump 251, a fluid displacement or acid egg vessel 252, and a venting or carbonator vessel 253.
  • the compressor 250 may comprise a two or more stage compressor or may comprise a single stage compressor.
  • the compressor 250 is also preferably of a type which draws in minimal air from atmosphere when used as a vacuum pump.
  • the compressor 250 may be a double-acting two stage articulating piston compressor with a dedicated piston shape as shown in Figure 13.
  • This type of compressor offers a high compression ratio in a compact single unit. Air ingress is minimal, as the piston seals are not exposed to atmosphere.
  • the second stage of the compressor, where the shaft enters is a more highly pressurised stage, ensuring any leakage will be to atmosphere rather than drawing in air.
  • Figure 14 shows a variation of the piston compressor in which it also acts to drive the pump 251 in the form of a positive displacement water pump. It is noted such a pumping configuration could also be incorporated into the plant 100 of Figure 1 as a substitute for the liquid ring compressor (s) .
  • a diaphragm compressor and a peristaltic compressor are other types of compressors which draw in minimal air when used as a vacuum pump.
  • the compressor is a peristaltic compressor it may comprise a multi channel compressor with different diameter tubing. So as to extend tubing life and selection there may be cooling between successive compressors in series, thereby dissipating heat and inducing condensation which acts as a buffer against temperature increase.
  • the compressor 250 is for acting as a fluid displacement pump to introduce mains water into the plant 200. This is done by compressing gas into the fluid displacement vessel 252 so as to pressurise the mains water therein. In doing so, the water is pushed into the otherwise isolated venting vessel 253.
  • the venting vessel 253 has been in fluid communication with the product drawdown vessel 208 and is
  • the fluid displacement vessel 252 is gravity filled (and re- filled) from the cool water reservoir 207, by locating the fluid displacement vessel 252 at an appropriate height with respect to the cool water reservoir 207.
  • the compressor 250 acts as a vacuum pump to introduce mains water into the plant.
  • one vacuum fill vessel replaces the two vessels 252,253.
  • This vacuum fill vessel has characteristics of both vessels 252,253.
  • the vacuum fill vessel is connected to the cool water reservoir 207 in the same manner as the fluid displacement vessel 252 and is in fluid communication with the product drawdown vessel 208 in the same manner as the venting vessel 253. It is also placed above the product drawdown vessel 208.
  • the compressor takes suction from the vacuum fill vessel and evacuates the mainly carbon dioxide gaseous contents to the vapour space of the product drawdown vessel 208.
  • the vacuum fill vessel may then be filled by the vacuum drawing in water from the cool water reservoir 207 or possibly even by gravity fill. Thereafter, the vacuum fill vessel is isolated from the cool water reservoir 208 and comes into fluid communication with the product drawdown vessel 208 during the desorption step.
  • venting of extraneous gases is from a relief valve on the vacuum fill vessel or the product drawdown vessel 208.
  • more carbon dioxide is likely to be lost as opposed to carrying this step out in the venting vessel 253 of the previous embodiment .
  • more than one vacuum fill cycle may be performed for a full operational cycle of the plant 200, thereby minimizing the size of the vacuum fill vessel for the addition of a fixed amount of mains water to the plant 200.
  • the water may be transferred from the vacuum fill vessel to the product drawdown vessel 208 by means other than gravity by using the desorption gases to pressurise the water in the vacuum fill vessel into the product drawdown vessel 208.
  • the plant 200 also comprises a valve system 220 for directing the fluid flow during the operation of the plant 200 at the different operation steps.
  • the valve system 220 comprises a plurality of valves (marked 20-36) .
  • the plant 200 also comprises a pre-cooler 254 for cooling as well as scrubbing and dehumidifying the combustion gases from the combustion unit 201 .
  • the pre- cooler 254 comprises a vessel containing water, through which the combustion gases are bubbled. The heat lost to the water in the pre-cooler 254 from the combustion gases is used as a heat source for heating the sorber/desorber 206 during desorption. This occurs by flowing water through heat exchange tubes in the pre-cooler 254 and then through heat exchange tubes in the sorber/desorber 206.
  • the pre-cooler 254 has an inlet for mitigating noise created by the downward flow of condensation against the upward flow of combustion gases entering the pre- cooler 254 from the combustion unit 201 .
  • the inlet is shown comprising two tubes; an inner tube 255 and an outer
  • the inner tube 255 receives the combustion gases from the combustion unit 201 at its lower end, the gases escaping from the inner tube 255 at its upper end, into the outer tube 256.
  • the outer tube 256 is sealed at its upper end, to prevent gases from leaving the outer tube 256 at its upper end. Spaces 257 are provided at the lower end of the outer tube 256 for the gases to pass out of the outer tube 256 and into the pre-cooler space.
  • the outer tube 256 acts as insulation for the inner tube 256, thus acting against the condensation of the water formed in the combustion reaction in the inner tube 256. Any condensation formed in the inner tube 255 would tend to flow downwardly under gravity against the upward flow of the combustion gases, thus creating noise.
  • condensation is primarily formed in the outer tube 256, where it flows downwardly under gravity in the same direction as the flow of the combustion gases, which does not create much noise.
  • the inlet of the pre- cooler could be an inlet tube surrounded by insulation material or a venturi nozzle, which would also mitigate noise.
  • the tubes 255, 256 are designed whereby the top of the inner tube 255 is above the water level in the pre-cooler 254 when no combustion gases are passing through the pre-cooler 254 and the gas head space in the pre-cooler 254 is at atmospheric pressure. This means that when at these conditions, water does not flow down the inner tube 255 and possibly into the combustion unit 201 .
  • the outer tube 256 is designed whereby its top is just submerged in the water in the pre-cooler 254 during sorption to avoid heating of the gas space in the pre-cooler 254.
  • the pre-cooler 254 also has a water volume control mechanism in the form of a gravity drainage leg 258. The drainage leg 258 controls the water volume in the
  • pre-cooler 254 by allowing excess water above a design water level to exit the pre-cooler 254 through the drainage leg 258 under gravity, at an appropriate time in the operation of the plant 200. Generally this is when the pre-cooler 254 has been allowed to return to atmospheric pressure, and no combustion gases are being bubbled through. This drainage is required because the volume of water in the pre-cooler 254 increases as combustion gases are bubbled therethrough and the water produced in the combustion reaction is condensed out into the pre-cooler water. The drained water from the pre-cooler 254 is sent by gravity drainage leg 258 to the evaporator 225.
  • the drainage of the excess water from the pre-cooler 254 also provides the function of purging impurities that may build up in the pre-cooler water, having been scrubbed from the combustion gases. It is noted that valve 29 on the drainage leg 258 is opened and closed appropriately to act against air ingress to the pre-cooler 254 through the drainage leg 258. It is also possible that the volume of water in the pre-cooler 254 may decrease, due potentially to evaporation to atmosphere through valve 33 (which is open when the plant 200 is at rest to allow the pre-cooler 254 to be at atmospheric pressure) or through valve 29 or even through the inner tube 255 and the combustion unit 201. In this case defrost water from the refrigerator may be inputted to the pre-cooler 254 through the water volume control mechanism in the form of the gravity drainage leg 258 to make up this lost volume of water in the pre-cooler 254.
  • pre-cooler 254 could be incorporated within the plant 100 described above in relation to Figures 1 to 5.
  • the plant 200 also operates according to a batch process involving the four general steps of sorption, pressure release, vacuum purge and desorption.
  • the plant 200 also involves the steps of water pressurisation, fluid
  • Natural gas is combusted in the combustion unit 201 according to the aforementioned reaction and the combustion product gases are bubbled through the pre- cooler 254 to cool, scrub and de-humidify them.
  • the compressor 250 draws the gas through pre-cooler 254 and valve 20, compressing at least a substantial component of the gas into the sorber/desorber 206 through valve 23, where the carbon dioxide is preferentially sorbed onto the sorbent bed. It is noted that the volumetric flow rate into the compressor 250 from the pre-cooler 254, together with the positioning of the spaces 257 in the outer tube 257 of the pre-cooler inlet should be designed so as to avoid drawing air into the pre-cooler through the gravity drainage leg 258. The same effect could be achieved through closure of valve 29.
  • Sorption is aided by the flow of cooling water though heat exchanger tubes in the sorber/desorber 206. This is driven by the pump 251, which draws mains water from the cool water reservoir 207 through valve 24 and pumps it through the heat exchanger tubes of the sorber/desorber 206. The cooling water returns to the cool water reservoir 207 via valve 26.
  • the pump 251 during the sorption step is an air lift pump using relief gases from the sorber/desorber 106.
  • the venting vessel 253 has been previously in fluid communication with the product drawdown vessel 208 and is thus filled with mainly carbon dioxide. Thus, as the water is pressurised into the venting vessel 253 from the fluid displacement vessel 252, some mixing of the water with carbon dioxide to produce carbonated water occurs.
  • valves 34 and 35 are closed (which isolates the venting vessel 253) and valve 31 first and then valve 32 are opened to start the step of fluid displacement vessel filling ( Figure 8) .
  • This also means that all of the compressed gas from the compressor 250 is now being sent to the sorber/desorber 206.
  • the fluid displacement vessel 252 is filled under gravity through valve 32 from the cool water reservoir 207. As this occurs, gas left in the fluid displacement vessel 252 from the prior step of water pressurisation is displaced through the top of the vessel through valve 31 and sent to the evaporator tray 225 (and therefore to atmosphere) .
  • valve 32 is closed (but valve 31 is left open) and valve 35 is opened to allow for venting of extraneous gases which are mainly nitrogen, from the venting vessel 253 ( Figure 9) .
  • the desorbed gases which were in the venting vessel 253 were not 100%
  • the extraneous gases in particular the nitrogen gas, have become enriched in the vapour space by virtue of the preferential dissolution of the carbon dioxide in the water over nitrogen.
  • the vented gas is vented from the top of the venting vessel 253 through valve 35 to the bottom of the fluid displacement vessel 252. This provides for some recovery of any carbon dioxide in the venting gases (and which would otherwise be lost) by dissolution of the carbon dioxide in the water in the fluid displacement vessel 252.
  • the vented gas bubbles through the fluid displacement vessel 252 and escapes at its top to flow to the evaporator 225 (and hence to atmosphere) through valve 31.
  • FIG. 10 the next step in the operation of the plant 200 is pressure release .
  • the sorber/desorber 206 is isolated from gaseous feed by the closure of valve 20 .
  • the sorber/desorber 206 is subsequently let down to atmospheric pressure by opening valve 28, which directs gas to the evaporator tray 225 for evaporation of any condensation in the let down gas .
  • FIG 11 in conjunction with
  • the next step in the operation of the plant 200 is vacuum purge.
  • the vacuum purge step occurs by opening valve 21 and vacuuming a substantial amount of the extraneous gas out of the sorber/desorber 206 through the compressor 250.
  • valve 23 An optional recycle of the gas across the compressor 250 (ie. from its outlet to its inlet) may be provided through valve 23.
  • the previously mentioned vacuum valve may also be incorporated.
  • the vacuum purged gases may be subsequently vented to atmosphere from the compressor outlet. However, preferably, the gas flows from the outlet of the
  • Desorption occurs with the compressor 250 continuing to apply vacuum on the sorber/desorber 206 through valve 21.
  • the compressor 250 compresses this mainly carbon dioxide gas into the venting vessel 253 through valve 22 .
  • the venting vessel 253 is now in gas and liquid communication with the product drawdown vessel 208 through valves 30 and 36.
  • the venting vessel 253 is positioned above the product drawdown vessel 208, so that the liquid flows to the product drawdown vessel 208 through valve 30 under gravity. Because valves 30 and 36 are open, the venting vessel 253 and product drawdown vessel 208 act as a single volume during desorption.
  • valves 30 and 36 remain open once operation of a single cycle of the plant 200 is complete, and stay open during any periodic dispensing from the product drawdown vessel 208.
  • the valves 30 and 36 are closed upon start-up of operation of the plant, which begins with the sorption step.
  • venting vessel 253 is emptied of liquid by the end of the desorption step to act against a low level signal being recognised in the product drawdown vessel 208 and operation of the plant 200 commenced with carbonated water in the venting vessel 253.
  • Desorption is aided by the application of heat on
  • the sorber/desorber 206 (so as to effect a thermal swing in addition to the pressure swing) .
  • This may be achieved by any suitable source of energy, including the use of waste heat from the refrigerator which the plant 200 is associated with.
  • the heat is applied to the sorber/desorber 206 by pumping water from the discharge of pump 251 through heat exchanger tubes in the sorber/desorber 206 and then via valve 27 through heat exchange tubes in the pre-cooler 254 where it is heated by hot water in the pre-cooler 254. Thereafter, the water recirculates to the suction of pump 251 via valve 25.
  • the water in the pre-cooler 254 has been heated by the combustion gases during sorption.
  • the pump 251 does not need to draw on any water from the cool water reservoir 207, but instead re-circulates the water which was left in the tubing after the sorption step.
  • heat is applied to sorber/desorber 206 during desorption by recirculating (using pump 251) the heated pre-cooler water directly into the heat exchanger tubes of the sorber/desorber 206 and then back to the pre-cooler 254 without the need for heat exchange tubes in the pre-cooler 254.
  • This configuration should deliver superior heat transfer.
  • the cool water reservoir 207 is the source of water feed to the plant 200 and therefore the carbonated water produced by the plant 200
  • the plant 200 also comprises a backflow mitigation system 240 for mitigating any backflow of mains water into the sorber/desorber 206, in particular when there is a power cut to the plant 200.
  • the backflow mitigation system 240 comprises firstly desorbing into the vapour space of the venting vessel 253 rather than the normal procedure of introducing carbonating gases below the water level and secondly comprises a first check valve 260, located between the venting vessel 253 and the sorber/desorber 206, more specifically between the venting vessel 253 and the outlet of the compressor 250.
  • the first check valve 260 prevents backflow of water from the venting vessel 253 to the sorber/desorber 206.
  • the plant also comprises a second backflow mitigation system 241.
  • the second backflow mitigation system 241 comprises a second check valve 235 between the suction of compressor 250 and gaseous space of the pre-cooler 254.
  • This check valve 235 acts to prevent pressurised gases feeding back into the pre-cooler 254 during a power cut. Such pressurisation could push water from the pre-cooler 254 via the inner tube 255 and the firebox 201. Not only would this extinguish the flame but there would be no cooling of combustion gases on further cycles, thereby damaging the compressor.
  • the second backflow mitigation system 241 may also comprise a thermostat switch on the compressor 250 or a level switch on the pre-cooler 254 to provide an added precaution against this eventuality.
  • a plant 300 for producing carbonated water according to a further embodiment
  • the plant 300 is also particularly suitable for use in relation to a refrigerator. Similar features of the plant 300 to the plant 100 shown in Figures 1 to 5 have been designated with the same reference number, but have been prefixed with the numeral 3 instead of 1.
  • the plant 300 purifies the carbon dioxide by filtration and therefore can operate on a continuous basis for the duration of a cycle.
  • the plant 300 comprises a combustion unit 301, a cool water reservoir 307 and a product drawdown vessel 308.
  • the plant 300 also comprises at least one, preferably two membranes 370, 371.
  • the membranes 370, 371 may be any suitable membranes, such as anion exchange membranes for example.
  • the plant 300 also comprises a compressor for each of the membranes.
  • the two membrane compressors 372, 373 are each for forcing the combustion gases through its respective membrane 370, 371 to form a filtrate on one side containing mostly carbon dioxide and a rentate on the other side containing mostly impurities.
  • the membrane compressors 372, 373 are liquid ring compressors.
  • the liquid used in the liquid ring membrane compressors 372, 373 is condensate from the combustion reaction.
  • the membrane compressors 372, 373 could, of course, be any other suitable type of compressor.
  • the plant 300 also comprises at least one further compressor, preferably two further compressors 374, 375 for pressurisation and mixing of the filtered gases from the membranes 370, 371 and the mains water, drawn from the cool water reservoir 307.
  • the two further compressors 374, 375 are two individual liquid ring compressors contained within a single stage. However, each individual compressor may be contained within its own stage.
  • the compressors 372, 373, 374, 375 of the plant 300 may be a single unit driven by the same motor or be separate units driven by separate motors.
  • one of the further compressors could be a compressor for
  • the pressurised gas and the pressurised water could be mixed to produce carbonated water either in the product drawdown vessel 308 or in another vessel.
  • the sorber/desorber may be replaced with a membrane-contactor (such as the membrane-contactor described in Society Automotive Engineers (US) Technical Paper 901295) .
  • the circulating liquid sorbent sorbs carbon dioxide through one membrane and desorbs through another membrane .
  • FIG 16 a plant 400 for producing carbonated water according a further embodiment of the present invention is shown.
  • the plant 400 is also particularly suitable for use in relation to a refrigerator. Similar features of the plant 400 to the plant 100 shown in Figures 1 to 5 have been designated with the same reference number, but have been prefixed with the numeral 4 instead of 1.
  • the plant 400 provides an illustration of how carbon dioxide, purified by processes other than membrane filtration or swing sorption or available as a by-product in a substantially purified form could be pressurised and mixed with water to produce carbonated water.
  • a liquid ring compressor 480 to compress and mix the substantially purified carbon dioxide gas and mains water from the cool water reservoir 407, to produce carbonated water.
  • the carbonated water being sent to the product drawdown vessel 408 for storage and dispensing.
  • the processing units of plants 100,200,300,400 may be positioned in a number of locations in relation to a refrigerator. A particular configuration may be dependent on other design aspects of the refrigerator.
  • Processing units which are not for refrigerated water storage may, for example, be located in the ambient
  • This may be advantageously achieved by placing the processing units on a slidable tray which fits behind the air grille at the bottom front of the refrigerator (not shown) .
  • the tray and grille may even be one piece.
  • the tray may slide out for inspection and maintenance of the processing units.
  • the product drawdown vessel 108, 208, 308, 408 may be advantageously located in the door of the fresh food section of the refrigerator as shown elsewhere herein.
  • a dispensing conduit may extend from the product drawdown vessel 108, 208, 308, 408 from a location in the above freezing fresh food section of a refrigerator to the ambient space under the refrigerator, and then to a dispenser in the door of the freezer section of the refrigerator (not shown) .
  • This is a pathway commonly used by still water dispensers in side-by- side refrigerators .
  • the heat gain to the carbonated water product through this ambient exposure may be counteracted by similar means used to counteract the ambient exposure for still water dispensing such as recycling the carbonated water via the dispenser inlet side through the product drawdown vessel 108 208 308 408 using a pump (not shown) .
  • Other means may include the provision of an insulated jacket (not shown) .
  • This cooling means for the carbonated water dispenser may be separate from or in common with the still water dispenser's cooling means.
  • the jacket may surround both the still water and the carbonated water dispensing conduits.
  • Refrigerated air or cooling water is circulated through the insulated jacket, such as from the cool water reservoir 107, 207, 307, 407 by a pump (not shown) .
  • the dispensing conduit which extends through the cool water reservoir 107 207 307 407 to the dispenser may be formed (at least in part) from
  • insulated heat conducting metal tubing In this arrangement heat is conducted along the metal tubing to make up for ambient exposure heat gain.
  • a flexible piece of metal wire may be positioned in a plastic dispensing conduit so as to have one end in the product drawdown vessel 108,208,308,408 and one end near the dispenser (not shown) .
  • the wire may or may not be fixed at either end and may have an extended surface area associated with the product drawdown vessel 107, 207, 307, 407. As the heat travels more quickly along the metal than the water this will act against the ambient section warming .
  • a separate above freezing compartment may be located in the freezer door (not shown) to house the product drawdown vessel 108,
  • This smaller above freezing compartment in the freezer door may be appropriately cooled by directing refrigerated air through the compartment in a similar way used to cool the above freezing fresh food section of the refrigerator.
  • refrigerated air may be recirculated so as to flow through the fresh food section via the above mentioned insulated jacket then via the abovementioned compartment in the freezer door and finally via the freezer section of the side-by-side refrigerator.
  • plants 100, 200, 300, 400 are of particular application in the incorporation in relation to a refrigerator or other refrigerated device such as a water cooler they may be adapted for use in other applications.
  • a plant according to embodiments of the present invention may be used in respect of a fermentation plant (such as in the brewing of beer) where the fermentation gases (comprising mostly carbon dioxide) can be captured and sent to the plant for the production of carbonated water.
  • a soft drink plant 500 for the production and dispensing of soft drinks. This may be done by mixing carbonated water from the product drawdown vessel 108, 208, 308, 408 with syrup from any one of one or more syrup packages 501 in a post-mix manner. It is noted that the vapour space of the product drawdown vessel 108, 208, 308, 408 is in fluid communication with the syrup packages 501 so as to carbonate and act as a propellent of the syrup from the syrup packages 501 in the post-mix production of the soft drinks.
  • the soft drink plant 500 may also be able to fill a removable container with a post-mix soft drink by separate or combined dispensing of the soda water and carbonated syrup from the dispense tap shown in Figure 17, whereafter the removable container may be manually sealed.
  • the soft drink plant 500 could be used in a pre-mix manner to carbonate the contents of the removable container 502 which has been previously filled with uncarbonated water and uncarbonated syrup. This may be done by exposing the vapour space in the removable container to the vapour space of the product drawdown vessel 108, 208, 308, 408 possibly via a check valve.
  • the soft drink plant 500 may comprise a manual three port, two position valve 503 to achieve this.
  • the valve 503 may also act as a snift valve to purge any air originally in the vapour space of the removable container 502 to atmosphere by at least one set of successive pressurising and venting steps .
  • the air may be allowed to reach equilibrium with the vapour space of the product drawdown vessel 108, 208, 308, 408.
  • a sparger line may be utilised to carbonate below the surface of liquid in the removable container 502, rather than into the vapour space.
  • the manual valve may be a three position multi port valve. It may also be advantageous in this
  • Carbonated water is produced by providing a gas containing carbon dioxide and mixing the gas containing carbon dioxide with water in a vessel.
  • the gas may be provided for example by burning natural gas on site and mixing the purified combustion products with the water in the plants and processes as described above.
  • the step of providing the carbon dioxide involves providing a pressurized carbon dioxide cylinder.
  • further embodiments of the present invention also comprise allowing gas from the water-gas mixture in the vessel to accumulate in a chamber.
  • This accumulated gas or at least a portion of the accumulated gas is vented from the chamber when dispensing carbonated water from the vessel or during filling of the vessel.
  • the solubility of the carbon dioxide in the water is dependent on the temperature and pressure of the water and the presence of any other gases in the system.
  • the carbon dioxide may be fed to the vessel as an essentially pure source, extraneous gases are dissolved in the water (from outside the plant 600) and also enter the vessel. These gases are mainly, nitrogen (given that it is the main constituent of air) and oxygen. Some of the extraneous gases will be displaced from the water by the carbon dioxide occupying any gas space in fluid communication with the vessel, including any space created by the dispensing of carbonated water from the vessel. If no
  • Gases may be vented to alleviate this problem, however, care must be taken in venting gases from the vessel as carbon dioxide will be vented at the same time as any extraneous gases. Therefore, excessive venting will be wasteful of carbon dioxide feed, as well as reducing the pressure in the vessel and hence the amount of carbonation of the water.
  • FIG. 1 Further embodiments of the present invention are concerned with an improved plant and method for producing carbonated water especially in relation to a refrigerator and further where the carbonated water is dispensed in conjunction with still water from a refrigerator.
  • the embodiments may however be adapted to other water dispensing devices such as a water cooler.
  • Carbonation systems using an installed pressurized cylinder of carbon dioxide may be of various types, including systems which use a source of pressurized water either from a mains water supply or a pump and other systems which rely on the user delivering an essentially manual burst of carbon dioxide gas in a batch manner to a fixed amount of still water in a container but without an essential inventory of already produced carbonated water to drawn on.
  • the plants of these embodiments of the present invention rely on an essential on demand inventory of carbonated water for the consumer to draw on and a
  • pressurized source of water either from a mains water supply or a pump
  • the plant 600 is particularly useful for incorporation into a refrigerator with a mains water feed.
  • the carbonated water may be dispensed in conjunction with cold still water .
  • the plant 600 comprises a suitably pressurized water feed 601, a still water holding tank 602, a pressurized carbon dioxide feed 603, a vessel 604, an external chamber 605, a venting system comprising a three way dispensing valve 606 and a dispenser for dispending carbonated water 607.
  • the water from the water feed 601 may flow through a check valve 615 of a type required by regulatory authorities and/or a treatment device (not shown) such as a carbon filter before entering the holding tank 602.
  • the pressurized carbon dioxide feed 603 is preferably provided from a cylinder of a gas containing carbon dioxide.
  • the vessel 604 comprises inner and outer passages 608 and 609 respectively which are in fluid communication and provide opposing flow paths. That is, the inlet of the inner passage 608 is located at the same end of the vessel 604 as the outlet of the outer passage 609. Similarly, the outlet of inner passage 608 is in fluid communication with and located at the same end of the vessel 604 as the inlet of the outer passage 609.
  • the passages 608 and 609 are separated by a tube 610 provided inside the vessel 604.
  • the passages 608, 609 may be aligned substantially horizontally or vertically. However, for the plant 600 the flow passages 608 and 609 are substantially vertical.
  • the passages (which provide opposing flow paths) may comprise carbonated water product off take tubing entering the top and extending to near the bottom of a larger diameter feed
  • the vessel may comprise a plurality of passages.
  • this may involve more than one concentric passages.
  • the plurality of passages of the vessel may comprise a hose tank.
  • a hose tank is characterized by a small diameter and long length. The long length may be effectively "compressed" so as to allow the hose tank to fit in a particular dimensional space. This may be achieved by coiling a particular length of hose into a substantially spiral shape or by forming successive opposed U tubes. In either case the hose tank may be considered to have a plurality of passages which provide opposing flow paths to each adjacent passage.
  • pressurized cold water from the still water holding tank 602, such as a hose tank in the back of a refrigerator, flows into the top of the inner passage 608 of the vessel 604 (although in another arrangement it could be the top of the outer passage 609) , via a pressure differential valve 611, check valve 612, and a controller in the form of a throttling valve 613.
  • the pressure differential valve 611 is for acting to maintain the pressure of the carbon dioxide below the pressure of the water between the vessel 604 and the holding tank 602 so as to mitigate backflow of carbon dioxide. This pressure differential could, however, be achieved in any other suitable way.
  • the check valve 612 is for maintaining the integrity of the water in the holding tank 602 and the vessel 604 (ie. to prevent backflow of the carbonated water) .
  • the controller in the form of the throttling valve 613 is for controlling water flow into the vessel 604 so as to adjust the relative amount of carbon dioxide to water flowing into the vessel 604.
  • the gas containing carbon dioxide also flows into the top of the inner passage 608 (although in another
  • the check valve 616 is for ensuring the integrity of carbon dioxide gas upstream of it.
  • the gas containing carbon dioxide has a lower pressure than the water at the pressure differential valve 611, due to the water pressure drop across the check valve 612 and the throttling valve 613, the gas containing carbon dioxide is at sufficient pressure to enter the inner passage 608 together with the water.
  • the vessel 604 is for carbonating and mixing but it is also for storage of the product carbonated water. Most of the mixing is done in the inner passage 608.
  • the tube 610 separates the inner passage 608 and outer passage 609 and helps to ensure incoming water and incoming gas containing carbon dioxide are not mixed with the product off take from the dispensing valve 606. For most demand scenarios the tube 610 should be sized appropriately so that the inner passage 608 is not filled with the gas containing carbon dioxide on dispensing of product.
  • An automatic drain float valve is a float valve that closes when a design low liquid level is reached.
  • both the gas containing carbon dioxide and water enter at the top of the vessel 604 they could enter in the mixing tank 604 in any possible arrangement.
  • the gas containing carbon dioxide for example may enter as bubbles below the water surface in the vessel 604 but preferably this should not be so low as to generate mixing between the passages 608, 609.
  • the water may enter as a spray or droplets or may be
  • the dispensing valve 606 is a three way valve which when at rest and no carbonated product is being dispensed, is aligned so that the top of the inner passage 608 and the top of the outer passage 609 are in fluid communication through the external chamber 605 which is above the top of the inner passage 608.
  • the vessel 604 is essentially full of liquid when at rest and at equilibrium. That is, it does not have a designed for fixed gaseous head space as may be achieved by incorporation of a float valve system for example. It will still experience a gaseous space build up in a designed for manner but this will be transient and not fixed at any particular location.
  • any gases that do build up at the top of the inner passage 608 will, by proper sizing of the external chamber 605 and the inlet line 614 connecting the inner passage 608 to the external chamber 605 via the three way valve 606, flow predominantly to the external chamber 605.
  • the three way valve 606 changes alignment so as to dispense carbonated water from the top of the outer passage 609 while at the same time venting the accumulated gases in the external chamber 605 to atmosphere via the dispenser 607.
  • the venting is achieved by flowing the carbonated water being dispensed through the chamber 605. This results in the chamber 605 being open to and fluidly communicating with the dispenser 607.
  • the flow of carbonated water through the chamber 605 upon dispensing physically pushes at least a portion of the gas that has accumulated in the chamber 605, out of the chamber 605.
  • This same dispensing causes carbon dioxide and water to enter the inner passage 608 so as to replenish the dispensed product.
  • the three way dispensing valve 606 therefore allows for a controlled venting of extraneous gases which may build up in the vessel 604.
  • FIG 20 a similar plant 700 for producing carbonated water to the plant 600 is shown.
  • the plant 700 there is a fixed intervening gaseous space at the top of the inner passage 708.
  • This fixed intervening gaseous space is created by the float valve 717.
  • the three way valve 706 allows gas to flow between the inner passage 708 and the outer passage 709 thereby creating the internal chamber 705 above the outer passage 709 due to the equilibration of liquid levels.
  • the three way valve 706 is aligned to allow for dispensing at the dispenser 707 the accumulated gases in the internal chamber 705 are vented to atmosphere via the dispenser 707.
  • venting gas from the whole of the typically annular space of the internal chamber 705 above the outer passage 709 may be a greater volume than required. However, it is possible to vent gas from only a portion of the internal chamber 705 thereby reducing the volume of gas vented. Such a portion of the chamber may have continuous vertical surfaces with its lower open surface above the "at rest" water level so as to allow for free movement of gases from the remainder of the outer passage 709 above the water level.
  • the plant 700 may also have an external chamber similar to that of plant 600 so as to give greater flexibility to vary the effective venting volume on site. Varying the venting volume may enable minimization of carbon dioxide losses.
  • the portion of the total chamber that is external to the vessel may be maximized by changing the configuration so as to have small diameter carbonated water product outlet tubing within a large diameter feed tube.
  • the carbonated water exits the vessel from the inner passage and the inflow of carbon dioxide gas and water is to the outer passage.
  • valve alignment there may be a short period of time when all three ports are open. Consequently, when using such valves the top of the inner passages 608, 708 of the vessels 604, 704 may be in fluid communication with the dispenser 607, 707 for a short duration via the three way valve 606, 706. This may have an additional timed venting effect, by venting a portion of the vapour space above the inner passage 608, 708. Such a timed venting effect may, however, be achieved by other means as will be discussed further on in the specification.
  • the inlet to the three way dispensing valve 606 and 706 from the inner passage 608, 708 may, in a variation, have a further on/off valve in the line (not shown) , which is responsive to the liquid level in the inner passage 608, 708 such as a further separate float valve or an ancillary valve function in the float valve 717 (in the case of plant 700) .
  • this on/off float valve would be to allow gaseous fluid communication between the inner passage 608, 708 and the chamber 605, 705 via the three way dispensing valve 606, 706 only when there is a high water level in the inner passage 608, 708 and when any extraneous gases are at a high concentration in the vapour space of the vessel 604, 704.
  • This variation has particular relevance to a situation where more than one opening and closing of the three way dispense valve 606, 706 occurs in quick succession so as to serve consecutive drinks. In such a situation the liquid level in the inner passage 608, 708 may not have had sufficient time to return to a full level before the next drink is served.
  • any venting of a portion of such a gas above the lower liquid level in the inner passage 608, 708 via the chamber 605, 705 may not be as effective in removing extraneous gases and indeed be wasteful of carbon dioxide compared with the situation where the portion of the gas vented via the chamber 605, 705 came from a gaseous space above a high
  • a temporary build up of extraneous gases may occur in vessels with a fixed designed for vapour space such as vessel 704. If this fixed designed for vapour space is too small the pressure exerted by this temporary build up of extraneous gases may become too high and prevent an appropriate amount of carbon dioxide from entering the vessel 704.
  • the three way dispensing valve may be also used for dispensing from the top of a plurality of such passages in a vessel if required by creating a manifold at the top or side of such passages depending on whether the passages are aligned substantially vertical or horizontal.
  • a three way dispensing valve in accordance with embodiments of the present invention is also applicable to dispensing from storage vessels such as the product drawdown vessel 106 of the plant 100 described above.
  • the hose tank may have a plurality of passages of a small cross sectional area as compared with an equal capacity vessel of the type shown in Figure 19. At sufficiently low cross sectional areas, due to the fluid dynamics of the system, the accumulated
  • gases can be made to flow with the flow of water into the next passage.
  • This critical tube diameter may vary slightly with the wetability of the tube surface but for many materials may be considered to be approximately 10 mm.
  • any extraneous gases in the hose tank which do not dissolve in the water may accumulate in any number of chambers within the hose tank.
  • these chambers may therefore not necessarily be located at the top of the hose tank where two adjacent passages meet but may be at an intermediate height due to surface tension.
  • the accumulated gases in these chambers may therefore gradually move with the flow of dispensed carbonated water from passage to passage, not rising to the top of a passage when the flow stops and eventually to the dispenser. Consequently feed may be introduced even to the top of a downward flowing spiral hose tank and accumulated gases will eventually flow to a dispenser at the bottom of the spiral hose tank.
  • the hose tank may not require a three way dispensing valve to vent the accumulated gases and an on/off dispensing valve will be sufficient.
  • the three way dispensing valve may also incorporate features known in on/off dispensing valves to minimize foaming or decarbonation on dispensing.
  • plants 600 and 700 may be identical in another variation.
  • This second three way valve acts as an extra precaution against backflow of carbonated water in the plants 600 and 700 applicable where mains water is utilized as the pressurized feed 601 701.
  • a plant 800 incorporating the above variation of the second three way valve is shown.
  • the water level in the vessel 804 is controlled by a float switch 817 acting on the second three way valve 818 rather than the mechanical float valve 717 of the plant 700.
  • the second three way valve 818 is preferably a solenoid valve.
  • a mechanical three way valve such as a float operated spool valve or diaphragm valve may also be used.
  • the second three way valve 818 is aligned such that the water upstream side of a check valve 812 in the rest position is in fluid communication with atmosphere via the second three way valve 818 when no power is applied to the solenoid. Consequently, at rest gaseous flow to atmosphere from the vessel 804 is prevented by the check valve 812.
  • the pressure differential valve 811 in addition to acting as a backflow mitigation measure also serves to appropriately regulate the carbon dioxide pressure in the vessel 804, by the selection of an appropriate pressure differential.
  • the venting system may therefore also comprise a buffer volume 819 between the three way dispensing valve 806 and the dispenser 807 and a suitable diameter at the dispenser 807.
  • This buffer volume 819 is to act against an unacceptable blast of pressurized gas exiting the dispenser 807 on dispensing. It is furthermore desirable that the line from the three way valve 806 to the dispenser 807 is well drained so as to avoid an aliquot of water being dispensed followed by a blast of gas and then the bulk of the carbonated water. This may be achieved by having the outlet of the three way dispensing valve 806 above the dispenser 807 and connected to it by substantially straight tubing of a suitable material and diameter.
  • the venting system may also comprise a ball float valve 820 or any other similar such valve incorporating the features of valves generally known as "air release” or w air vent” valves.
  • the ball float valve may have a vertical leg 821. Initially, the ball float valve 820 would loosely close off fluid communication with the dispenser 807 by gravity allowing vented gases out through the vertical leg 821, whereafter as carbonated water flowed through, the ball float would rise to close the vertical leg 821 and open fluid communication with the dispenser 807.
  • the venting system may comprise flow channels from the top of the ball float valve 820 down to the dispenser 807 to cater for slight leakage of liquid from the upper seal of the ball float valve 820 during dispensing.
  • the function of the three way dispensing valve 806 and the ball float valve 820 may be achieved by a single multiport valve (shown in later Figures) using separate gaseous and liquid flow paths.
  • a chamber which had been in fluid communication with the vapour space at the top of the inner passage 808 of the vessel 804 is isolated and then
  • the gas containing carbon dioxide and the water may converge in a mixing point before entry to the vessel 604, 704, 804 and the hose tank. This may achieve superior carbonation efficiency.
  • FIG 22 shows a plant 900 incorporating this variation.
  • the carbon dioxide gas enters the water inlet to the vessel 904 via a mixing point 922 down stream of the check valve 912. Consequently, the carbon dioxide can enter the vessel 904 via this route whether water is flowing or not and thus enable the make up of any small leakage of carbon dioxide from the vessel when the plant is in the rest position. This is possible because the three way valve 918 which controls the flow of water into the vessel 904 is upstream of the mixing point 922.
  • the carbon dioxide may be prevented from entering the vessel 604 after the water has stopped flowing in because of the higher water pressure relative to the carbon dioxide pressure at the mixing point or within the vessel 604. This is due to the pressure differential valve 611.
  • valving such as a two position controllable on/off fill valve (not shown) in the water flow path upstream of the mixing point, which when closed in the rest position allows carbon dioxide to enter the vessel 604 or the hose tank.
  • the additional valving may comprise a carbon dioxide two position controllable three way valve (not shown) which allows the carbon dioxide to enter the
  • the additional two position controllable valving may be part of a multifunctional valve and be activated by a water level or a timing signal.
  • the timing signal may be at the end of a period initiated by the dispensing valve 606, 706 or the on/off dispensing valve of the hose tank.
  • the carbonated water produced in the plants 600, 700, 800, 900 may also be combined with syrups for the production of soft drinks.
  • Plant 900 shows this variation.
  • the combination of syrup and carbonated water may be made in a post mix manner whereby a syrup package 923 is pressurized by the regulated carbon dioxide gas pressure. On dispensing, this results in the three way valve 906 and the syrup valve 927 acting together in an appropriate way so as to deliver an appropriate quantity of syrup for mixing with the carbonated water from the vessel 904 through the post mix unit 928 to the dispenser 907.
  • Carbonated water alone may also be dispensed through the dispenser 907 when the syrup valve 927 is closed.
  • a removable container 929 may be nominally filled with still water together with an appropriate quantity of syrup.
  • the removable container 929 may then be sealed and brought into fluid communication with the regulated carbon dioxide pressure.
  • the fluid communication may be via the vapour space of the removable container 929 only or via a sparger below the liquid surface. Fluid communication via the vapour space may take longer to achieve an acceptable product but would avoid turbulence created by the sparger.
  • the vapour space of the removable container 929 may be purged of extraneous gases by at least one set of successive pressurizing and venting steps via a manually
  • a check valve 931 may be utilized to ensure extraneous gases from the removable container 929 do not flow back into the vessel 904. The liquid in the removable container 929 is then allowed to reach equilibrium with the vapour space, then sealed and removed.
  • the syrup package 923 on installation may similarly be purged of extraneous gases by at least one set of successive pressurizing and venting steps via a manually activated three port valve 932.
  • a suitable water pressure in the mains water supply needs to exist.
  • a suitable water pressure in this regard is in the order of 3 bar.
  • a pressure regulator rather than the differential pressure valve could be used to regulate the carbon dioxide pressure from the pressurized carbon dioxide cylinder, and without the backflow mitigation afforded by the pressure differential valve but with other suitable backflow mitigation.
  • a pressure regulator may also be used for configurations utilizing a break tank for water feed and a water pump. Referring now to Figures 25-29 there is shown further plants 1000, 1100, 1200, 1300, 1400 each comprising a water pump, a break tank and a carbon dioxide gas regulator.
  • FIG 25 shows a plant 1000 wherein water is pumped from a break tank 1034 via a water pump 1035 into the vessel 1004. Carbon dioxide gas flows into the vessel 1004 via the carbon dioxide gas regulator 1036.
  • the pump 1035 preferably an electrically driven pump, is controlled by the float switch 1017 that is for maintainng a maximum water level in the vessel 1004.
  • the float switch 1017 may be controlled by a single level or dual level probes .
  • the break tank 1034 is fed with water from the discharge of the still water holding tank 1002 via a float valve 1037, although any other level control valve may be used in the break tank 1034.
  • the float valve 1037 is for maintaining a substantially constant water level in the break tank 1034.
  • the break tank 1034 also incorporates a drain 1038 the connection of which to the break tank 1034 is at a level between the maximum design water level in the break tank 1034 and the level at which the water enters via the float valve 1037. This ensures an effective backflow mitigation for the plant 1000 via an air gap.
  • the drain 1038 may flow to the evaporator tray under the refrigerator (not shown) .
  • the drain 1038 is shown in Figure 25 as open to the atmosphere. However it may have an air filter or automatic drain outlet as described elsewhere herein, such as a buoyant ball sitting on a seat merely by gravity. Should an overflow situation arise the ball would float allowing the water out. Otherwise the ball would loosely sit on the seat minimizing contamination from the air.
  • the break tank 1034 further has a lid 1039 to avoid contamination of water in the break tank 1034 from the air.
  • the break tank may also be made from or have an inner surface of an anti-microbial material.
  • the break tank 1034 also has a conduit 1040 from the vertical leg 1021 of the ball float valve 1020 to below the water level near the bottom of the break tank 1034.
  • the bottom end of the conduit 1040 may have a diffuser (not shown) for reasons that will become apparent further on in the description.
  • the plant 1000 also comprises a minimum liquid level mechanism in the form of an automatic drain 1041 on the outlet of the vessel 1004 so as to maintain a minimum design water level on the outlet of the vessel 1004. This prevents the possibility of pressurised carbon dioxide
  • the automatic drain 1041 as shown in Figure 25, is merely a buoyant ball on a seat that seals by gravity and the pressure differential between the vessel 1004 and atmosphere.
  • the ball floats above its seat, opening the outlet of the vessel 1004.
  • a low level switch and a solenoid valve may also be utilized to maintain a minimum design water level in the vessel 1004. Indeed any mechanism to prevent pressurised gases blasting through to the dispenser 1007 on dispensing from a low level, which does not rely on the volumetric flowrate capacity of pump 1035 to maintain water level, is preferable for plant 1000.
  • Prior carbonators implicitly rely on the volumetric flowrate capacity of the pump being greater than or at least approximately the same as the volumetric flowrate dispensing rate of the carbonated water for an acceptable operation. These prior carbonator devices may be considered adaptations of commercial post-mix carbonators rather than being specifically designed for a domestic refrigerator or other such smaller capacity use.
  • the pump In the plant 1000 shown in Figure 25, the pump
  • volumetric flowrate capacity which is less than the volumetric flowrate of the dispenser, preferably much
  • a pump has particular advantage in relation to a refrigerator in terms of cost, space and complexity of the pump.
  • the pump 1035 may for example be a peristaltic pump or any other suitable pump. Also, because of the low flowrate to the vessel, the incoming water to the vessel may be more fully carbonated and the dilution of the carbonated water already in the vessel 1004 is less. Thus, the product quality in the vessel is maintained as the vessel is being filled.
  • the effective venting procedures outlined herein also provide for a low pressure pump.
  • the combination of a low volume/low pressure pump is especially advantageous for small use applications such as in a domestic refrigerator in terms of cost, space and complexity.
  • consumer demand is satisfied primarily from the capacity of the vessel 1004 rather than the volumetric capacity of the pump 1035.
  • the vessel 1004 being refilled at a low volumetric flowrate over the long period of time that product is not being dispensed, is typically sufficient given a sufficient volume in the vessel 1004.
  • Such a low volumetric capacity pump combined with an automatic drain on the outlet of the vessel may result in carbonated water product being temporarily unavailable due to a low level in the vessel 1004 at certain times. However this may be acceptable in many consumer settings and the capacity of the vessel 1004 may be adjusted upward if necessary to meet expected demand.
  • gases are vented from the external chamber 1005 via the vertical leg 1021 of the ball float valve 1020 and the conduit 1040 to below the surface of the break tank 1034.
  • the vented gases are bubbled to the surface of the liquid in the break tank
  • Figure 26 shows a similar plant 1100 to the plant 1000 of Figure 25 comprising a water pump 1135 and a break tank 1134.
  • the plant 1100 has an alternate automatic drain 1141 with a float and lever arm.
  • the plant 1100 also incorporates a two position multiport valve 1142 activated when dispensing from the vessel 1104 occurs.
  • the multiport valve 1142 comprises a first on/off valve 1143 for dispensing carbonated water only together with a second on/off valve 1144 upstream of an external chamber 1105 and a third on/off valve 1145 downstream of the external chamber 1105 for the purpose of venting the external chamber 1105.
  • the discharge port of the third on/off valve 1145 may flow through a check valve 1146 to atmosphere.
  • the multiport valve 1142 may be a spool or pinch valve or other known valves incorporating a plurality of valving functions activated by a substantially single input. In the rest position the first and third valves
  • the check valve 1146 may not be necessary especially as the dispensing function is normally of short duration. It may nevertheless act to prevent the flow of extraneous gases back into the external chamber 1105 during venting. Such backflow may occur without the check valve 1146 due to the chamber 1105 being at atmospheric pressure at the end of the venting step and also because of the turbulence created by the venting step. Extraneous gases flowing back into the chamber 1105 will negate the venting process.
  • the check valve 1146 may be substituted by a suitably long length of narrow diameter tubing which will also mitigate backflow of extraneous gases into the chamber 1105. In another embodiment the check valve 1146 is upstream of the external chamber 1105 between the vessel 1104 and the external chamber 1105. This also prevents backflow into the vessel 1104.
  • venting may occur in the reverse order, that is with second valve 1144 open on dispensing and closed at rest, but this may be less effective.
  • the second valve 1144 is a solenoid valve controlled by the float switch 1117, although it may also be a float valve within the vessel 1104. In this embodiment the second valve 1144 would allow gaseous flow into the chamber, whether an internal chamber or an external chamber, only when there was a full or substantially full level in the vessel 1104. This full level may be indicated by a float switch 1117.
  • the venting system is operated in association with a full or substantially full level in the vessel and the dispensing function.
  • this variation the venting system is operated in association with a full or substantially full level in the vessel and the dispensing function.
  • venting may not occur on every dispensing of carbonated water from the vessel.
  • FIG. 27 shows a further plant 1200 incorporating a different two position multiport valve 1242 activated on dispensing.
  • the multiport valve 1242 comprises two on/off valves 1243 and 1247 which are both closed in the rest position and open on dispensing.
  • the restrictive orifice 1248 serves to limit the venting of gases to an appropriate quantity. This is a timed venting effect whereby a portion of the chamber above the water level of the vessel 1204 is vented during the dispensing function.
  • the restrictive orifice 1248 may be sized appropriately given the pressure within the vessel 1204 so as to vent an appropriate quantity of gas to atmosphere.
  • Figure 28 shows a further plant 1300 incorporating a venting system whereby an external chamber 1305 is vented on filling of the vessel 1304 rather than on dispensing from the vessel 1304.
  • the float switch 1317 that controls the pump 1335 also controls a three way valve 1349, typically a solenoid valve.
  • the three way valve 1349 vents the external chamber
  • the plant 1300 has check valve 1346 to mitigate backflow of extraneous gases into the system particularly as the filling function is likely to be longer than the dispensing function hence providing more time for undesirable diffusion of extraneous gases into the plant 1300.
  • the external chamber 1305 comes into fluid communication with the vapour space of the vessel 1304 when there is a maximum level in the vessel 1304 and is thereby filled when extraneous gases are at a
  • Figure 29 shows yet a further plant 1400 comprising a different pumping arrangement.
  • the pumping comprises a double acting diaphragm pump 1435 although it may be a double acting piston pump or other pneumatic pump.
  • the double acting diaphragm pump 1435 of the plant 1400 is powered by the pressurised carbon dioxide rather than being an electrically powered pump described previously.
  • the pressurised carbon dioxide used to power the pump is derived from a take off downstream of the regulator 1436 via a three way valve 1450.
  • the take off is also upstream of a check valve 1451.
  • the three way valve 1450 is either for directing the flow of carbon dioxide toward the double acting diaphragm pump 1435 when the vessel is filling or toward the vapour space of the vessel 1404 when the vessel 1404 is full so as to supply make up carbon dioxide gas.
  • the three way valve 1450 is preferably a solenoid valve controlled by float switch 1417. The three way valve 1450 therefore acts to start and stop a filling cycle of the vessel 1404.
  • the double acting diaphragm pump 1435 comprises two flexible diaphragms 1452, 1453 connected by a fixed connecting rod 1454.
  • Each flexible diaphragm 1452, 1453 is disposed between respective first spaces 1455, 1456 which are in fluid communication with pressurised carbon dioxide gas and respective second spaces 1457, 1458 which are in fluid communication with water drawn from the break tank 1434.
  • the pressurised carbon dioxide which powers the double acting diaphragm pump 1435 enters the first spaces 1455, 1456 via a toggle valve 1459.
  • the carbon dioxide gas is also exhausted from the first spaces 1455, 1456 via the toggle valve 1459.
  • the alternate first space of the first spaces 1456 is exhausted, causing the connecting rod 1454 to travel towards the first space 1456 being exhausted.
  • a toggle mechanism associated with the connecting rod 1454 and the toggle valve 1459 arranges the toggle valve 1459 so that the exhausted first space 1456 comes into fluid communication with the regulated pressurised carbon dioxide gas. This forces the connecting rod in the opposite direction. Consequently a pumping action is generated.
  • the double acting diaphragm pump 1435 is therefore a metering pump and pumps a given quantity of water per quantity of gas.
  • the pressure of the regulator 1436 the ratio of water to carbon dioxide may be varied. At a regulator pressure of 4 bar approximately four volumes of carbon dioxide will be pumped by the double acting diaphragm pump per volume of water. This is the required ratio for an acceptable carbonated water product.
  • the three way valve 1450 acts to allow carbon dioxide gas into the vessel 1404 only via the double acting diaphragm pump 1435 during filling and not via check valve 1451. Thereby excess carbon dioxide gas is not added to the vessel 1404 and the performance of the double acting diaphragm pump 1435 is improved.
  • a suitable pressure differential also needs to be created between the regulated gas pressure which powers the double acting diaphragm pump 1435 and its exhaust pressure in order for the double acting diaphragm pump 1435 to operate effectively.
  • gases are not wasted to atmosphere but recovered in the vessel 1404 a back pressure exists in the vessel 1404 against which the double acting diaphragm pump 1435 must pump.
  • the above four volumes of carbon dioxide will, at equilibrium, dissolve in the metered amount of water at 3 bar in the vessel 1404. Consequently a potential suitable pressure differential of 1 bar exists to power the double acting
  • check valve 1451 in this embodiment not only serves to maintain the integrity of the upstream carbon dioxide gas as for similar previous embodiments herein but also has a substantial cracking pressure in the order of 1 bar so as to maintain the appropriate pressure differential between the vessel 1404 and the regulated pressure powering the double acting diaphragm pump 1435.
  • the exhausted gas and water may exit the double acting diaphragm pump 1435 separately so as to flow preferably via check valves into the vessel 1404 (not shown) or may be mixed at a mixing point prior to entry to the vessel 1404.
  • the water and carbon dioxide combine in a premixing vessel 1460, before entry to the vessel 1404.
  • the pressure of the carbon dioxide gas in combination with the water is reduced (at the temperature of 4 0 C) as compared to in the undissolved state. This volumetric contraction assists in the pressure differential required by the double acting diaphragm pump 1435 to pump into the vessel 1404.
  • the volumetric contraction is more rapid when the dissolution is in pure water as in the premixing vessel 1460 as compared to being added separately to the already highly carbonated water in the vessel 1404.
  • a separate venting system This is similar to the venting system of the plant 1200 of Fig. 9 but rather than having a
  • the plant shown in Figure 29 comprises a restrictive device which is a check valve 1461 with a cracking pressure less than the equilibrium pressure of the vessel 1404 in the rest position.
  • the vessel 604-1404 and its connections should be made of a material impervious to gases or at least with a low permeability to gases.
  • Figures 30 and 31 show a means to recover carbon dioxide from the vented gases (however produced) as an alternative arrangement to bubbling the gases through the break tank 1034 as in the plant 1000 shown in Figure 25.
  • an inverted bucket 1562 is placed within a break tank 1534.
  • the inverted bucket 1562 has a top 1563 which is closed except for a small orifice 1564 and an open bottom 1565.
  • the small orifice 1564 in the top of the inverted bucket 1562 mates with a fixed sealing member 1566 attached essentially rigidly to the break tank 1534.
  • the small orifice 1564 and the fixed sealing member 1566 therefore constitute a valve.
  • the inverted bucket 1562 sits within a sleeve 1567 on footings 1568.
  • the sleeve 1567 and footings 1568 are further supported by a fixed perforated base 1569 rigidly attached to the break tank 1534.
  • vented carbon dioxide gas from the plants 1000 1100 1200 1300 1400 for example flows into the top 1563 of the inverted bucket 1562 by a flexible connection 1570. However it may also be introduced to the open bottom 1565 of the inverted bucket 1562 but preferably above the top of the perforated base 1569 and the pump inlet 1571.
  • break tank 1534 although it may also be below the water level at any part of a cycle.
  • Figure 30 shows the position of the bucket 1562 when the plant is at rest after a sufficient time since the last dispensing.
  • the break tank 1534 will therefore be 'overfull' as shown in Figure 31 by comparison with Figure 30. That is the water level 1573 in the break tank 1534 will be higher than the equilibrium water level determined solely by the float valve 1537. Consequently no water will flow into the break tank 1534 via the float valve 1537 until the pump 1535 or dissolution of the vented gases in the water in the break tank 1534 reduces the water level 1573 in the break tank 1534 to the appropriate level.
  • the drain 1538 and the level at which water enters the break tank 1534 should be sufficiently above the 'overfull' level in the break tank 1534 to ensure
  • the check valve 1574 ensures backflow of vented gases does not occur from the inverted bucket 1562 such as via the ball float valve 1020 and the dispenser 1007 of plant 1000 once dispensing stops. However it is possible the ball float valve 1020 itself may provide some backflow mitigation.
  • the inverted bucket 1562 may preferably have a volumetric capacity consistent with the venting associated with one or two drinks though it may be larger. Any excess volumetric venting will pass out through the perforated base 1569 and bubble to the surface.
  • the inverted bucket 1562 may form a considerable volumetric portion of the break tank 1034 leaving only the necessary passage way for bubbles to readily migrate to the surface. By this means carbon dioxide recovery may be enhanced. This is because this will maximize the time before water flows again into the break tank 1534 via the float valve 1537 and dilution occurs.
  • the inverted bucket 1662 is fixed to the perforated base 1669 which is rigidly fixed to the break tank 1634.
  • the inverted bucket 1662 is therefore in a fixed position and not buoyant. Furthermore the inverted bucket 1662 does not have a small orifice in its top and there is no need
  • the vented gases may be vented into the top or bottom of the inverted bucket 1662 in a similar manner as into the inverted bucket 1562 though there is no need for a flexible connection. However for Figures 32 and 33 the gases are vented into the top of the inverted bucket 1662.
  • the inverted bucket 1662 may similarly have a portion above the water level or be totally below the water level in the break tank 1634 at any part of the cycle. The accumulation of extraneous gases in the inverted bucket 1662 may be prevented by their dissolution in the water or by successive venting steps eventually breaching the bottom of the inverted bucket 1662 with gases bubbling to atmosphere through the perforated base 1669.
  • the accumulation of extraneous gases in the inverted bucket 1662 may also be prevented by the inverted bucket 1662 or its connections 1670 being of a gas permeable material.
  • the permeation rate would preferably be such that minimal carbon dioxide gas is lost via permeation during the relatively short filling time but that for an extended period at rest, sufficient permeation would occur. This would be driven by a pressure differential due to a higher water level in the break tank 1634 compared with the lower water level inside the inverted bucket 1662 as a result of the accumulation of extraneous gases .
  • the vessel 604 - 1404 is simple in structure. It would be desirable to place it at a convenient location in the refrigerator where the contents would remain cold, such as at the back and bottom of the refrigerator next to
  • a preferable location for the vessel 604 - 1404 would be in the door of the refrigerator. However, this is not the coolest location in the refrigerator especially with opening and closing of the refrigerator door.
  • the vessel 604 - 1404 may be cooled appropriately. This is because the air space near the bottom of the refrigerator is sufficiently cool.
  • a reason for this is that many refrigerators have crisper bins located in the bottom of the "above freezing" fresh food section of the refrigerator and cold air is directed under these crisper bins so as to keep their contents colder than the remainder of the refrigerator. Also the colder air being more dense tends to remain at the bottom of the refrigerator.
  • the lower heat conducting portion of the vessel may further have finned heat conducting protrusions 1775 in the air space at the bottom of the refrigerator as shown in Figure 34. These fins allow a pathway for the substantially upward flow of air so as increase heat transfer arising from natural convection. This may be achieved for example by the finned heat conducting protrusions 1775 being horizontal with holes 1776 as shown in Figure 34. Furthermore, so that the rise of air is not impeded by a horizontal flat bottom of the vessel 604 - 1404 the bottom of the vessel may be tapered 1777. Alternatively the finned protrusions 1775 may project out
  • a spatially effective means of achieving this may comprise a cylindrical vessel 604-1404 having square finned protrusions 1775 as shown in plan view in Figure 35.
  • the lower heat conducting portion may be advantageously achieved, for example by a metallic "screw in" bottom (plug) into a polymer vessel 604 - 1404.
  • the lower heat conducting portion of the vessel 604 - 1404 may further comprise heat conducting protrusions up into the vessel 604 - 1404. These protrusions may also have a secondary function as a baffle so as to direct flow transverse to the main flow in the inner passage 608, 708, 808, 908, etc so as to avoid short circuiting of flow in the inner passage 608, 708, 808, 908, etc.
  • Prior carbonators located in the door of a refrigerator have been smaller than the vessels 604 - 1404 indicated in the layout shown in Figure 23. Such prior carbonators have required expensive cooling means to adequately cool the water as it flows through the carbonating vessel. However, because of the larger size of the vessel 604-1404 once cooled such as by the method outlined above it is resistant to warming due to the high heat capacity of water and the larger volume of water in the vessel 604-1404. It therefore does not require such expensive cooling means.
  • the low flowrate of water into the vessel from the low volumetric flowrate pump 1035 does not impose a high heat load on the vessel 604-1404 caused by the mixing of the carbon dioxide and water.
  • the vessel 604 - 1404 is
  • a specially refrigerated and insulated compartment within the door of the refrigerator This may be in the door of the "above freezing" fresh food section of the refrigerator or for a side by side refrigerator, for example, may be in the freezer door in which a combined cold still water dispenser and ice dispenser is typically located.
  • the specially refrigerated and insulated compartment may be maintained at the correct temperature by flowing air over the evaporator within the freezer and then through the specially refrigerated and insulated compartment in an appropriate way and with appropriate dampening control as is common for maintaining a correct temperature in other sections of the refrigerator.
  • the dispensing valve 606, 706, 806, etc in the refrigerator door is that the recess in the door in which the dispenser 607, 707, 807, 907 for serving the drinks is located not far from the dispensing valve 606, 706, 806, 906. Consequently a dedicated carbonated water line is possible rather than a common line with still water from the back of the refrigerator, which may cause dilution of both water streams. Also, the three way dispensing valve 606, 706, 806, 906 etc., is readily placed above the dispenser 607, 707, 807, 907 etc. Furthermore, any malfunction of equipment resulting in a leakage flow to atmosphere as designed for in the backflow mitigation system will be in view of the consumer. While the carbon dioxide feed 603, 703, 803 etc. in the form of a cylinder is also shown within the refrigerator such as in Figure 23 for example it may also be placed outside the refrigeration space.
  • Figures 23 and 24 indicate a possible layout for the plant 600 - 1400 in a refrigerator. Shown therein is a valve or pump housing 633 - 1433 as a possible location for the various valves or pump of the plant 600 - 1400.
  • the break tank 1034 - 1634 may also be placed in
  • the door of the refrigerator preferably in close association with the vessel 1004 - 1004. It may also have an insulated upper portion and a lower heat conducting portion.
  • the vessel placed in the door of the refrigerator there will be turbulence at the water level as the door is open and closed.
  • the pump 1035 be started and stopped by dual level sensors located in an upper portion of the vessel. The difference in the level of the sensors would be suitably greater than the difference in the water level created by the turbulence. This would avoid the pump 1035 turning on and off needlessly due solely to the turbulence.
  • Another means to protect against surface turbulence may involve housing the level sensor 1017-1417 in a buffering container (not shown) .
  • the buffering container may have an open top above a maximum turbulent surface and a closed bottom suitably below a full, but turbulent minimum, water level, except for a small hole or labyrinth channel. There may be a suitable small wall clearance between the level sensor 1017-1417 and the buffering container. This may also mitigate surface turbulence to which the level sensor 1017-1417 might be exposed.
  • the space allocated to the vessel 604-1403, pump/valve housing 633-1433, and cylinder 603-140 as shown in Figure 23 may have a dual purpose use. This is to allow the consumer the option to readily allocate the space to alternative foodstuffs at any time if they longer need the carbonation plant 100-1400.
  • the full width shelves of a normal refrigerator may be maintained with removable or
  • adjustable bottom portions of the horizontal shelves These removable or adjustable portions would preferably be at the hinging end of the door so as to allow the location of the plant as shown in Figure 23.
  • Such removable or adjustable (slidable) shelves or bottom portions and compartment doors may be adjusted appropriately to allow for removal or installation of the plant 600-1400 according to particular preferential use of the consumer. While the above embodiments are applicable to a domestic refrigerator they may also apply to other devices for dispensing carbonated water such as a water cooler.
  • Embodiments of the present invention also relate to a rotary pinch valve housing a plurality of flexible tubes.
  • the rotary pinch valve of the present invention may be adapted to discrete settings, where rotation is stopped either manually or by other means, after the rotating mechanism has passed through a particular angulation.
  • rotary pinch valve of this invention is more particularly applicable where it is desired to produce fluid flow through a plurality of tubes in a particular sequence so as effect an automated processing outcome in a piece of equipment or other such use and preferably where the rotation is driven by an essentially constant speed device such as by an electric motor.
  • the rotary mechanism of the rotary pinch valve will usually be a rotating cam surface.
  • the full processing cycle will normally be defined by an angular rotation of 360 degrees of the rotating mechanism of the rotary pinch valve.
  • Patents US 3,506,032, US 3,918,490, US 4,282,902, US 5,113.906 indicate rotary pinch valves featuring a plurality of flexible tubes. However, these rotary pinch valves are intended for devices requiring essentially discrete positioning, such as manual laboratory apparatus,
  • Patents US 4,457,339 and US 4,694,861 describe two further rotary pinch valves designed for a plurality of tubes, again mainly for a laboratory setting, driven by stepper motors and intended to be easily reprogrammable.
  • US 4,457,339 has a limitation on the number of tubes capable of being handled as noted by US 4,469,861, which itself, while being highly programmable, is a complex and expensive device requiring a microcomputer controller.
  • the rotary pinch valve of the present invention therefore seeks to provide a rotary pinch valve suitable for a plurality of tubes, as might be required by an item of equipment requiring a particular sequencing of flows to be enacted for an automated cycle and preferably using a constant speed driver or a stepper motor.
  • the rotary pinch valve 1801 comprises a rotor 1802 a stator 1803 and a plurality of flexible tubes 1804 aligned parallel to the axis 1805 of the rotary pinch valve 1801.
  • the stator 1803 further comprises for each particular flexible tube 1806, a pinch slot 1809 and a rigid backing member 1810 supported by radial struts 1811.
  • a movable member 1812 is located within the pinch slot 1809 and when activated moves to pinch the particular flexible tube 1806 against the rigid backing member 1810.
  • Figure 36 shows, for illustration, but one such pinch slot 1809, movable member 1812 and rigid backing member 1810 for a particular flexible tube 1806.
  • each aligned flexible tube of the plurality of flexible tubes 1804 will require its own pinch slot, movable member and rigid backing member. Consequently a plurality of pinch slots are staggered around the circumference of the stator 1803 as well as along its axial length, one variation of which is shown in Figure 37.
  • a particular flexible tube 1806 also has flexible tubes 1807 and 1808 either side of it except for a particular flexible tube at the periphery.
  • the stator 1803 also comprises an end plate 1813 with alignment holes 1814 which are separated by alignment gaps 1815. This is matched by a similar set of alignment holes 1816 and alignment gaps 1817 at the other end of the stator 1803.
  • the stator 1803 also comprises an internal cylindrical annulus 1818 into which the essentially cylindrical rotor 1802 is placed with a close tolerance.
  • the end plate 1813 is removable from the stator 1803 so as to allow the essentially cylindrical rotor 1802 to be fitted into the
  • the diameter of the hole 1819 in the end plate 1813 is less than the diameter of essentially cylindrical rotor 1802. The end plate 1813 when fixed in place therefore maintains the rotor 1802 in axial position.
  • the rotor 1802 comprises essentially circular cam disks 1820 each with a particular cam surface 1821 separated by cam spacer disks 1823 and held together in an essentially cylindrical whole.
  • Each cam disk 1820 of the rotor 1802 interfaces with a particular pinch slot 1809 and movable member 1812 all of which are within in a particular pinch plane 1822 so as to act on a particular flexible tube 1806.
  • the cam spacer disks 1823 are placed between consecutive cam disks 1820 such that, given the tolerances available, a particular movable member 1812 is acted upon by only the intended cam disk 1820 in its pinch plane 1822 and is not acted upon by an unintended adjoining cam disk.
  • the cam spacer disks 1823 therefore may have a radius equal to or less than the smaller radius of the cam disk 1820.
  • the pinch slots 1809 in the stator 3 are also effectively placed to mate with the corresponding cam disk 1820 and so take account of the cam spacer disks 1823 in the rotor 1802. This may be achieved by stator spacer disks (not shown) which are the same thickness as the cam spacer disks 1823 and in the same plane.
  • FIG. 40 there is shown a cross section through a particular pinch plane 1822 so as indicate the pinch mechanism.
  • the movable member 1812 is shown to be acted upon by a pair of springs 1824 which are supported by a spring compression base 1825 associated with the stator 1803 within the pinch plane 1822.
  • the springs 1824 are also supported at their other end by lateral protrusions 1829 of the movable member 1812. The springs 1824 are to return the movable member
  • the natural resiliency of the tubing may be sufficient to return the movable member 1812 back to the open position, in which case the springs 1824, the spring compression base 1825 and lateral protrusions 1829 may not be required. This is especially true under conditions when the flexible tube carries fluid under pressure. However where the fluid is under vacuum the springs 1824 may be preferable.
  • FIG. 40 Also shown in Figure 40 are the radial struts 1811 which support the rigid backing member 1810. These radial struts 1811 encompass and align within the pinch plane 1822 the flexible tubes 1807 and 1808 either side of the particular flexible tube 1806 which is acted upon by a particular movable member 1812. Its is noted from Figure 40 there is a space between the particular flexible tube 1806, and adjoining flexible tubes 1807 and 1808 at an axial position where none are pinched. This space corresponds to the alignment gap 1815 between the alignment holes 1814 in the end plate 1813.
  • this space between the particular flexible tube 1816 and adjoining flexible tubes 1807 and 1808 may diminish almost completely when the particular flexible tube 1806 is pinched by the movable member 1812 and so spreads its width. Also by ensuring the adjoining flexible tubes 1807 and 1808 are pinched a suitable distance along the axial length of the stator 1803 to where the pinched particular flexible tube 1806 has returned to its unpinched diameter either upstream or downstream, it follows that any flexible tube of the plurality of flexible tubes 1804 where pinched within a pinch plane 1822 will be axially adjacent to two flexible tubes which are exhibiting an unpinched diameter within that same pinch plane 1822.
  • the rotary pinch valve 1801 can be made to be compact with a distance between adjoining unpinched flexible tubes being essentially half of the difference between the pinched and unpinched width of the
  • FIG. 41 there is shown a cross section through the stator 1803 which indicates aligners 1826 for the particular flexible tube 1826.
  • These aligners 1826 which are not shown in Figure 36 are to avoid the particular flexible tube 1806 moving laterally.
  • This essentially fixed lateral position allows the particular flexible tube 1806 to be pinched by a compact sized movable member 1812 the long edge of which in the pinch plane 1822 is approximately the same length as the pinched width of the particular flexible tube 1806.
  • the aligners 1826 are placed at an appropriate short distance upstream and downstream of the pinch slot 1809 where the particular pinched flexible tube 1806 returns to its unpinched diameter.
  • the aligners 1826 may be advantageously incorporated into a stator spacer disk with a cross section as shown in Figure 41.
  • aligners 1826 for the particular flexible tube 1806 are axially aligned in the gap between the unpinched flexible tubes 1806 and 1807 as well as the gap between flexible tubes 1806 and 1808 as shown in Figure 41.
  • the particular flexible tube 1806 is also axially aligned by the alignment hole 1814 in the end plate 1813 as well as by the radial strut corresponding with the rigid backing member of another flexible tube
  • pinch slot 1809 may have an exposed
  • This exposed long edge of the pinch slot 1809 is also essentially the same length as the long edge of the pinching surface of movable member 1812 and is chosen to be essentially the same length as the pinched width of a particular flexible tube 1806.
  • the radial struts 1811 may encompass more than three adjoining flexible tubes or less than three adjoining flexible tubes such as for peripheral flexible tubes. Furthermore the radial struts 1811 need not be fully radial but rather project appropriately outward from the stator 1803.
  • pinching surface of the movable member 1812 as shown in Figure 36 is rectangular. In other embodiments the long pinching edges of this pinching surface may be rounded so as to minimize cutting or shearing of a particular flexible tube 1806.
  • the curved surface of the movable member 1812 interfaces with the curved surface of the cam disk 1820. This is designed to deliver an abrupt change in valve state over as small an angle of rotation as possible.
  • the design of optimal interfacing cam surfaces to achieve such an abrupt change would be known to those skilled in the art.
  • a cam angle approximating 45 degrees on the cam surface 1821 which may also be curved at the outer edge so as to avoid a point, together with a curved surface
  • approximating a semicircle for the bottom of the movable member 1812 is determined to deliver such an abrupt change. It may be that more abrupt changes are possible as with greater angles than 45 degrees and with other curved surfaces on the movable member 1812 such as elliptical section shapes. It is desirable that the change of valve state from fully open to fully closed or vice versa can occur over as small a rotational angle as possible as from 5 to 15 degrees, for example. However this is ultimately dependent on the movement required of the movable member 1812 which is itself dependent on the diameter and wall thickness of the particular flexible tube 1806 as well as on the diameter of the rotor 1802 which is itself a function of the physical space allocated to the rotary pinch valve 1801.
  • stator 1803 of the rotary pinch valve 1801 is truncated. That is it is not cylindrical and has flat sides. However in another embodiment the stator 1803 may be fully cylindrical thereby allowing the plurality of flexible tubes 1804 to be placed fully around its circumference. However by close spacing a given number of flexible tubes of a certain diameter around the full circumference, depending on the number of tubes and their diameter, the diameter of the rotor 1802 may become excessively small. This could negatively influence the change of valve state sensitivity of the valve which is effectively proportional to the diameter of the rotor 1802. By truncating the stator 1803, the diameter of the rotor 1802 is maximized for a given number of flexible tubes of given diameter and physical spatial depth, in which to physically fit the rotary pinch valve 1801
  • the cam surface of the rotor 1802 is internal to the stator 1803. However in another embodiment it may also be external to the stator and rotate around the stator.
  • a desirable feature of the rotary pinch valve 1 is the external access to the plurality of flexible tubes 1804 which facilitates loading and replacing ruptured tubing. It is similarly desirable to be able to externally load the movable members 1812 and/or their associated springs 1824 into the respective pinch slots 1809 from the outside of the rotary pinch valve 1801 as loading from within the cylindrical annulus 1818 presents handling difficulties.
  • the loading of the movable member 1812 and/or associated springs 1824 into the stator 1803 is preferably done after the rotor 1802 has been placed inside the stator 1803 and before the plurality of flexible tubes 1804 are threaded into the stator 1803. This may be done by a number of means .
  • one means is to have an indentation 1827 either upstream or downstream of the pinch slot 1809.
  • the indentation 1827 therefore will be associated with a different pinch plane (s) to that of pinch slot 1809.
  • the movable member 1812 may be loaded into the indentation 1827 and slid axially and under the rigid backing member 1810, at which stage the flat pinching surface of the movable member 1812 will be flush with the bottom of the rigid backing member 1810 ( Figure 42) .
  • the lateral protrusions 1829 of the movable member 1812 may preferably fit just under the spring compression base 1825.
  • the movable member 1812 may then be lowered into pinch slot 1809 ( Figure 43) .
  • the springs 1824 may then be

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  • Life Sciences & Earth Sciences (AREA)
  • Food Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)

Abstract

La présente invention concerne un procédé de production d'eau gazeuse, le procédé comportant les étapes suivantes : la production sur place d'un gaz contenant du dioxyde de carbone; et le mélange in situ du dioxyde de carbone à de l'eau afin de produire de l'eau gazeuse.
PCT/AU2008/001448 2007-10-01 2008-09-30 Procédé et installation permettant de produire de l'eau gazeuse WO2009043088A1 (fr)

Applications Claiming Priority (14)

Application Number Priority Date Filing Date Title
AU2007905346 2007-10-01
AU2007905345A AU2007905345A0 (en) 2007-10-01 A mechanism
AU2007905346A AU2007905346A0 (en) 2007-10-01 An appliance
AU2007905345 2007-10-01
AU2008902352A AU2008902352A0 (en) 2008-05-14 An appliance
AU2008902352 2008-05-14
AU2008903490 2008-07-08
AU2008903490A AU2008903490A0 (en) 2008-07-08 An appliance
AU2008903742 2008-07-22
AU2008903742A AU2008903742A0 (en) 2008-07-22 An appliance
AU2008903993 2008-08-05
AU2008903993A AU2008903993A0 (en) 2008-08-05 An appliance
AU2008904406 2008-08-27
AU2008904406A AU2008904406A0 (en) 2008-08-27 An appliance

Publications (1)

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WO2009043088A1 true WO2009043088A1 (fr) 2009-04-09

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PCT/AU2008/001448 WO2009043088A1 (fr) 2007-10-01 2008-09-30 Procédé et installation permettant de produire de l'eau gazeuse

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AU (1) AU2008229713A1 (fr)
WO (1) WO2009043088A1 (fr)

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FR2953104A1 (fr) * 2009-12-01 2011-06-03 Adm Concept Systeme de distribution d'eau
CN108579345A (zh) * 2018-05-18 2018-09-28 蔡王钲 一种钢铁冶金废气环保处理设备
US10201785B2 (en) * 2013-07-18 2019-02-12 Sodastream Industries Ltd. Device for dispensing carbonated water
WO2019083741A1 (fr) * 2017-10-26 2019-05-02 Praxair Technology, Inc. Cassage du vide sans obstruction de ligne d'alimentation
CN110236391A (zh) * 2018-03-07 2019-09-17 佛山市顺德区美的饮水机制造有限公司 饮水机及其苏打水浓度控制方法和苏打水浓度控制装置
US11305242B2 (en) 2016-10-10 2022-04-19 Strauss Water Ltd Water carbonation unit and continuous water carbonation method
IT202200008375A1 (it) * 2022-04-28 2022-07-28 Watnext Ind S R L Sistema di frigo-gasatura di liquidi per uso domestico e ufficio

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DE102011004460A1 (de) * 2011-02-21 2012-08-23 Kuchenmeister Gmbh Verfahren zur Entfernung von in Schwaden enthaltenen organischen Inhaltsstoffen und deren Umwandlungsprodukten und zur Wärmerückgewinnung aus Schwaden und eine Vorrichtung zur Durchführung dieses Verfahrens
EP3019438B1 (fr) * 2013-07-12 2017-05-17 Britvic Soft Drinks Limited Système de distribution de boissons refroidies avec gazéificateur, et méthode

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2953104A1 (fr) * 2009-12-01 2011-06-03 Adm Concept Systeme de distribution d'eau
US10201785B2 (en) * 2013-07-18 2019-02-12 Sodastream Industries Ltd. Device for dispensing carbonated water
US11305242B2 (en) 2016-10-10 2022-04-19 Strauss Water Ltd Water carbonation unit and continuous water carbonation method
WO2019083741A1 (fr) * 2017-10-26 2019-05-02 Praxair Technology, Inc. Cassage du vide sans obstruction de ligne d'alimentation
US11178889B2 (en) 2017-10-26 2021-11-23 Praxair Technology, Inc. Vacuum breaking without feed line clogging
CN110236391A (zh) * 2018-03-07 2019-09-17 佛山市顺德区美的饮水机制造有限公司 饮水机及其苏打水浓度控制方法和苏打水浓度控制装置
CN108579345A (zh) * 2018-05-18 2018-09-28 蔡王钲 一种钢铁冶金废气环保处理设备
IT202200008375A1 (it) * 2022-04-28 2022-07-28 Watnext Ind S R L Sistema di frigo-gasatura di liquidi per uso domestico e ufficio

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