Abstract:
The current disclosure provides a carbonation unit ( 100 ) for use in beverage dispensers. The current disclosure also provides a new carbonation process and further provides a beverage dispenser including a carbonation unit ( 100 ) of this disclosure.

Description:
TECHNOLOGICAL FIELD 
       [0001]    The present disclosure concerns a carbonation unit for carbonating a dose of a beverage. 
       BACKGROUND ART 
       [0002]    References considered to be relevant as background to the presently disclosed subject matter are listed below: 
         [0003]    PCT application having the publication number WO 2014/041539 
         [0004]    PCT application having the publication number WO 2012/110885 
         [0005]    Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter. 
       BACKGROUND 
       [0006]    Beverage dispensers, including those intended to dispense a cold beverage, are widely known used. Also known are beverage dispensers including a carbonation unit and adapted to dispense a carbonated beverage, at times also in addition to a non-carbonated beverage. 
         [0007]    PCT application having Publication No. WO 2014/041539 discloses a beverage dispenser for on-demand preparation of carbonated beverages, as well as processes for preparing and dispensing carbonated beverages upon user-demand. 
         [0008]    PCT application having Publication No. WO 2012/110885 discloses a device for supplying water and soda. 
       GENERAL DESCRIPTION 
       [0009]    The current disclosure provides a novel carbonation unit for use in beverage dispensers. The current disclosure also provides a new carbonation process and further provides a beverage dispenser including a carbonation unit of this disclosure. 
         [0010]    The term “beverage” refers to any aqueous drinking liquid that may be carbonated to produce a carbonated beverage. It includes, for example, but not limited to, water, flavored-water, milk, alcohol-containing drink, etc. 
         [0011]    One of the features of the carbonation unit of this disclosure is the inclusion of an expansion chamber that is linked to the carbonation chamber. The link is typically through an opening at the upper end of the carbonation chamber, where, in use, there is a small head-space above the surface of the beverage within the carbonation chamber. Carbonation of the beverage in the carbonation chamber is through the introduction of pressurized carbon dioxide. As can be understood, once pressurized carbon dioxide is introduced into the carbonation chamber, the pressure inside the chamber increases substantially to that of the introduced pressurized carbon dioxide. This carbonation pressure is relatively high in order to ensure effective carbonation. If then the carbonated beverage will be dispensed, the high pressure remaining in the carbonation chamber will force the beverage out in a relatively violent manner and as a results it will be dispensed in a strong stream which may cause undesired splashes and laud noise. The provision of an expansion chamber and the inclusion of an expansion phase may, at least partially, obviate this issue. 
         [0012]    During carbonation, the link between the carbonation chamber and the expansion chamber is closed. Following carbonation, the link may be opened, permitting expansion of the pressurized gas giving rise to a pressure reduction to a lower pressure referred to herein as the “dispensing pressure”. As can be appreciated, the dispensing pressure is a product of (i) the carbonation pressure, (ii) the volume of the head-space and (iii) the volume of the expansion chamber. As can also be appreciated, variation in the working parameters, such as the carbon dioxide pressure or the volume of the head-space remaining after filling the carbonation chamber with the non-carbonated beverage, may result in some variations in the dispensing pressure between one operation cycle of the carbonation unit to another. It is the dispensing pressure which then propels the carbonated beverage out of the carbonation chamber, and then through to and out of a beverage dispensing outlet that is linked to the beverage outlet of the carbonation chamber (typically located at a bottom end of the carbonation chamber). The lower propelling force of the dispensing pressure permits a smoother outflow of the beverage through the dispensing outlet. 
         [0013]    The inclusion of an expansion chamber permits also a more efficient utilization of the carbonation chamber. In prior art carbonation units there was typically a need, through design or through defined operational parameters, to provide for a significant head-space in the carbonation chamber above the beverage to permit an eventual pressure reduction through an auxiliary, pressure-release mechanism. In the carbonation unit of this disclosure, the head-space can be kept to a minimum and thus the overall dimension of the carbonation chamber may be reduced; or, seeing it in another way, the amount of carbonated beverage that is prepared and can be dispensed is very close to the volume of the carbonation chamber. 
         [0014]    The carbonation unit, by some embodiments of this disclosure, typically has two concentric chambers (one enveloping the other), of which one is a cooling chamber and the other is the carbonation chamber, as will be described below. 
         [0015]    A carbonation unit provided by a first aspect of this invention comprises a carbonation chamber and an expansion chamber. The carbonation chamber has a beverage inlet for introducing beverage into the carbonation chamber; a pressurized gas inlet for introducing carbon dioxide into the carbonation chamber that typically ends with a nozzle that in use is immersed in the beverage within the carbonation chamber; an expansion outlet, typically at the upper end of the carbonation chamber; and a carbonated beverage outlet, typically at a bottom end of the chamber. The expansion chamber is linked to the expansion outlet through a sealable conduit. This conduit is sealed during carbonation, e.g. by a valve disposed within the conduit, and is opened thereafter. 
         [0016]    The unit may operate in a duty cycle that comprises (i) a carbonation phase, in which pressurized carbon dioxide is introduced into the carbonation chamber to produce a carbonated beverage; and (ii) an expansion phase, after conclusion of the carbonation phase, in which the expansion link is opened. The carbonated beverage can then be dispensed, in a dispensing phase, out of the carbonated beverage outlet towards and through a beverage dispensing outlet, the dispensing pressure inducing the force that propels the carbonated beverage in this dispensing phase. 
         [0017]    The duty cycle is typically controlled by an electronic control module that can be a part of or associated with the carbonation unit. 
         [0018]    During use, some pressurized gas flows from the carbonation chamber into the expansion chamber, which gas may include droplets or humidity/moisture, which may bring to some build up and/or condensation of liquid within the expansion chamber. Thus, according to an embodiment of this disclosure, the expansion chamber comprises a draining outlet for draining such liquid. According to this embodiment, the duty cycle typically comprises opening the draining outlet at the end of or following the dispensing phase. 
         [0019]    By an embodiment of this disclosure, the carbonation unit comprises an integral cooling arrangement. While it is possible, by some embodiments of this disclosure, to include a cooling element within the carbonation chamber (in which case there may be a need to provide some time, prior to carbonation or prior to dispensing for cooling the beverage within the carbonation chamber), the cooling arrangement is typically embodied in a cooling chamber, comprising or being associated with a cooling element. The beverage to be carbonated passes through the cooling chamber, and thereby cooled, before entering the carbonation chamber. 
         [0020]    By an embodiment of this disclosure, the cooling chamber and the carbonation chamber are formed as two concentric chambers that are in liquid communication with one another, of which a second chamber envelopes, a first chamber. Typically, the enveloping chamber is the cooling chamber and comprises a cooling element (for example, a helical cooling element) that is in direct contact with the beverage within the cooling chamber. Typically, the first and second chambers are separated by a heat-conducting wall, typically a thin metal wall. Through this arrangement, also the beverage in the carbonation chamber is continuously cooled. 
         [0021]    By some embodiments of this disclosure, the expansion chamber is integrally formed with the two concentric chambers constituting together one integral body. 
         [0022]    The carbonation unit may also comprise an initialization vent which permits release of air from within the unit to prevent back-pressure upon filling with the beverage. The vent is typically formed on a conduit linking the cooling chamber and the carbonation chamber. 
         [0023]    A second aspect of this disclosure provides a process for producing a carbonated beverage, comprising introducing a non-carbonated beverage into a carbonation chamber; introducing pressurized carbon dioxide into the carbonation chamber and maintaining pressure for a time sufficient to carbonate the beverage; linking an upper end of the carbonation chamber to an expansion chamber to thereby cause reduction in pressure to a dispensing pressure; and propelling the beverage out from the carbonation chamber, the force propelling the beverage being induced by the dispensing pressure. 
         [0024]    The steps in the above sequence may be repeated a few times in succession. This sequence may also comprise a step of draining the liquid out of the expansion chamber that follows the propelling step. In the event of repeated cycles, said draining step may be carried out only once every few cycles; i.e. not necessarily after each step of propelling. 
         [0025]    Provided by a third aspect of the invention, is a beverage dispenser that comprises a unit of the type disclosed herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: 
           [0027]      FIGS. 1A-1C  are external views of a carbonation unit according to an embodiment of this disclosure, wherein  FIG. 1A  is a perspective view from above;  FIG. 1B  is a perspective view from below; and  FIG. 1C  is a top elevation. 
           [0028]      FIGS. 2A and 2B  are longitudinal cross-sections along respective lines A-A and B-B, seen in  FIG. 1C . 
           [0029]      FIG. 3  shows a schematic block diagram illustrating the operational cycle of the unit of  FIGS. 1A-2B . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0030]      FIGS. 1A-2B  include schematic representations of several views of a carbonation unit according to an embodiment of this disclosure. As is no doubt clear to a person versed in the art, the described unit is only an example and this disclosure is by no means limited to this embodiment. 
         [0031]    While the carbonation unit of this disclosure is in principle usable for carbonating any type of beverage, a typical beverage is water. Thus, in the following description the unit will be described with reference to water as the beverage that is being carbonated, it being understood that this is illustrative and not intended to be limiting. As can be appreciated, the beverage may also be other than water, such as flavored water, alcoholic beverages, natural juices, etc. 
         [0032]    Unit  100 , shown in  FIGS. 1A-2B , includes body  102  extending between an upper base plate  104  and a bottom base plate  106 . The body and base plates may be made of plastic materials, metal, other polymeric materials, ceramics, etc. The unit has two concentric chambers including a carbonation chamber  108  enveloped by a cooling chamber  110 . The carbonation chamber has a water inlet  112 , linked to the cooling chamber  110  through conduit  114  that extends from a port  118  within cooling chamber  110  and is fitted with a valve element  116 . In use, once valve  116  is opened, a link is established between the cooling chamber  110  and the carbonation chamber  108  to permit cooled water to flow out of the cooling chamber into the carbonation chamber. Conduit  114  is fitted with vent  120  which permits, when needed (for example after first filling or during use), to release gas (e.g. air or vapor) which may be entrapped within the cooling chamber and which, if not released, may have an effect on the proper operation of the unit. 
         [0033]      FIGS. 1A-2B  show the unit in isolation. In use, the unit is linked to other functional components including, among others, a water source and a source of pressurized carbon dioxide. These additional elements are illustrated schematically as boxes in  FIG. 2A or 2B . 
         [0034]    The cooling chamber has a water entry port  122  which is linked to a water source  124 , typically a water line or a water reservoir. The force that propels the flow of the water into the unit, i.e. its entry into the cooling chamber, and then its flow from there to the carbonation chamber, may be by a pump (not shown) fitted onto line  126  that feeds the water into port  122 ; or where source  124  is the water line it may be the pressure within the water line. Where the propelling force is a pump, its activation may coincide with the opening of valve  116 . 
         [0035]    The carbonation chamber has also a pressurized gas inlet  128  that in use is linked to a pressurized carbon dioxide source  130 . The pressurized gas inlet  128  ends with a nozzle  132  that, in use, is immersed within the water in the carbonation chamber. In this specific embodiment, the carbonation chamber  108  is filled with water up to about line  134 , the level being controlled by a liquid sensor  136 . Another liquid sensor  140  is found at the bottom end of the unit, fitted within bore  141  formed in a plug member  142  that is inserted into the central bore of bottom base plate  106 . Plug member  142  is fitted with two  0 -rings  144  that ensure a liquid-tight seal. Once liquid sensor  136  becomes immersed in the water, an electrical circuit is closed between sensor  136  and sensor  140  through the water, thereby issuing a signal to a control unit (not shown) that consequently causes valve  116  to shut off. Thus, in use, there is a water-free head-space  138  that remains within the carbonation chamber after filling the chamber with water to be carbonated. 
         [0036]    Unit  100  also includes an expansion chamber  150  linked to expansion outlet  152  of the carbonation chamber through expansion link  154  which is sealable by a valve element  156  fitted thereon. The carbonation chamber also includes a carbonated water outlet  160  which is linked through conduit  162 , fitted with a valve element  163  to a carbonated water dispensing outlet, shown schematically as block  164 . Valve  163  is closed during carbonation but is opened to permit dispensing of the carbonated water out of outlet  164  by the force of the dispensing pressure remaining within the carbonation chamber after the expansion phase (see below). 
         [0037]    The expansion chamber  150  is formed in the bottom base plate  106  and has an annular shape defined around plug  142 . Expansion chamber  150  has a draining outlet  166 , which in use is linked to a valve (not shown) that may be opened at a suitable time during the operational cycle (see below) to drain liquid that may have accumulated in the chamber as a result of condensation or accumulation of aerosol droplets. 
         [0038]    The carbonation chamber is also fitted with a conduit  168  which is linked to a pressure gauge, shown schematically as block  170  in  FIG. 2B . Pressure gauge  170  monitors pressure and is designed to release pressure in the event that the pressure within the carbonation chamber rises beyond a defined maximal pressure, for operational safety. 
         [0039]    The operational cycle of the unit may controlled by a control module (not shown) linked to the different valves or pumps of the system. The operational cycle may include a number of phases. 
         [0040]    As can also be seen in  FIGS. 2A and 2B , embedded within the cooling chamber  110  is a helical cooling element  172  in which a cooling fluid circulates between cooling fluid inlet  174  and cooling fluid outlet  176 . The cooling fluid may be a gas or a liquid. The cooling fluid is cooled by a refrigeration unit which may be, for example, that disclosed in U.S. Pat. No. 7,645,381 or that subject of PCT publication serial no. WO 2011/030339. The cooling chamber  110  and the carbonation chamber  108  are separated by a heat conducting wall  180 , typically a thin metal wall. Thus, through the mediation of the heat conducting wall  180  also the water in the carbonation chamber will be continuously cooled. 
         [0041]    The operational cycle of the unit disclosed in  FIGS. 1A-2B  is represented by a block diagram in  FIG. 3 . For ease of description, the different phases of the operational cycle in the description below are defined as first phase, second phase, etc. However, the phase designation has no functional significance as all phase occur in succession and each of the phases may in principle be regarded as first. 
         [0042]    At a first phase  200 , water that was cooled in the cooling chamber  110  is introduced into the carbonation chamber  108 . For this, valve  116  is opened and in the event that the entire dispensing device or system in which the unit is included includes the propelling pump (fitted on line  126 ) it is also activated. The filling continues up to a point where sensing tip  137  of sensor  136  becomes immersed in the liquid, issuing a signal that induces cessation of water flow, namely, shutting off valve  116  and if existing and operating also shutting off said pump. 
         [0043]    In the second phase  210 , a valve (not shown) controlling release of carbon dioxide from the carbon dioxide source  130  is opened to permit pressurized carbon dioxide to enter the carbonation chamber through nozzle  132 . The pressure is maintained for a time, typically a few seconds, to ensure effective carbonation. 
         [0044]    In the third phase, valve  156  is operated thereby establishing a link between head-space  138  and expansion chamber  150  which brings the pressure in the unit down to a dispensing pressure. 
         [0045]    At the fourth phase, line  162  is opened to permit dispensing of the carbonated water out of dispensing outlet  164  by the force of the dispensing pressure. This dispensing phase is terminated once the carbonation chamber is entirely emptied, whereupon sensor  140  issues the appropriate signal (or ceases to issue such a signal) to induce closure of the valve controlling flow out of line  162 . 
         [0046]    In a fifth optional phase, draining outlet  166  drains the accumulated liquid. 
         [0047]    The water dispenser typically includes an activation button and the operational cycle proceeds automatically upon such activation. The fifth phase of drainage, may be repeated in every cycle or alternatively once in a few cycles.