Patent Publication Number: US-8973786-B2

Title: Beverage dispenser with on-demand refrigeration

Description:
TECHNICAL FIELD 
     The invention generally relates to liquid or semi-liquid dispensing systems in general, and more particularly, to beverage dispensers where one or more concentrates are mixed in a potable liquid according to a predetermined ratio. 
     BACKGROUND OF THE INVENTION 
     Liquid dispensers are widely used in various industries. Chemical solutions including fertilizers, pesticides, and detergents and so on are often mixed from various concentrates and solvents before dispensed for use or storage. Similar dispensers also find applications in the medical field. In the food and beverage industry, liquid dispensers are widely used in all kinds of venues such as quick service restaurants. 
     The liquid dispensers used in food and beverage industry reconstitute juice syrup concentrates with a potable diluent, e.g., potable water, and then dispense the reconstituted juice into a container at the point of consumption. This kind of dispensers are sometimes called “postmix” dispensers as they produce a final product in contrast to a “premix” beverage that is prepackaged with the final constituents (flavor, gas, etc.) and ready for consumption. For safety and taste reasons, a postmix beverage dispenser often requires refrigeration in the dispenser of various components that eventually go into the postmix product. 
     Existing liquid dispensing apparatuses used in the food and beverage industry often includes a water bath where an evaporator is placed to form an ice bank or reservoir. The ice bank in the water bath provides a cold reserve and is used to separately chill the potable water before it is mixed with the juice concentrate. Specifically, the potable water flows through heat exchange lines in the water bath and is cooled thereby prior to its combination with the juice concentrate. 
     The juice concentrate may also be cooled prior to its combination with the potable water. Typically, the concentrate is contained within a flexible bag or rigid plastic container from which the concentrate is pumped to a post-mix valve. The concentrate reservoir is held within a dedicated compartment in the dispenser housing. That compartment can be cooled by the circulation of cold water from the water bath through heat exchange coils in the concentrate compartment. 
     A beverage dispenser with a water bath is not the most energy-efficient way to refrigerate components of the dispenser as it relies on a cold reserve, ice or icy water, which provides an extra venue for energy loss. The cold reserve is not well adapted for providing immediate chilling either. Further, the water bath also requires additional maintenance. Furthermore, it takes up space and adds to the overall footprint of the dispenser. Accordingly, a more compact and efficient liquid dispenser is needed. 
     SUMMARY OF THE INVENTION 
     The present invention relates to various features of an improved liquid dispenser. These features will be discussed, for purpose of illustration, in the context of food and beverage industry but should not be contemplated to be limited to such applications. 
     The present invention provides a liquid or semi-liquid beverage dispenser that refrigerates a liquid flow inside the dispenser “on demand.” Further, the refrigeration system operates in an ice-free environment. The present invention is particularly advantageous for refrigerating an intermittent liquid flow. The dispenser includes a conduit for a potable liquid and a refrigeration system, which in turn, includes a plate heat exchanger. A portion of the conduit for the potable liquid is situated inside the plate heat exchanger to refrigerate the potable liquid. 
     In an embodiment of the invention, the refrigeration system is capable of lowering the potable liquid&#39;s temperature by at least 5 degrees Fahrenheit (about 2.8 degrees Celsius). The plate heat exchanger may be a brazed plate heat exchanger, e.g., a copper or stainless steel brazed plate heat exchanger. The plate heat exchanger includes a refrigerant conduit situated next to a portion of the potable liquid conduit; the plate heat exchanger may be configured to provide a counter-flow pattern for a refrigerant and the potable liquid. 
     In an embodiment, the refrigeration system is actuated when a sufficient amount of the potable liquid has entered the conduit. This can be accomplished through a control system in the dispenser. 
     In an embodiment, the refrigeration system further refrigerates a housing for a concentrate that is to be mixed with the potable liquid inside the beverage dispenser, e.g., at or below 40 degrees Fahrenheit (about 4.4° C.). In one feature, the refrigeration system refrigerates only one of the potable liquid and the housing at a given time. In one embodiment, the refrigeration system is configured to prioritize refrigeration of the potable liquid over the housing. 
     In another aspect, the present invention is directed to a method for refrigerating on demand an intermittent flow of a potable liquid in a beverage dispenser. The method includes the steps of: providing a refrigeration system including a plate heat exchanger for the beverage dispenser, and incorporating a portion of a conduit for the potable liquid into the plate heat exchanger to refrigerate on demand the intermittent flow of the potable liquid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing, and other features and advantages of the invention, as well as the invention itself, will be more fully understood from the description, drawings and claims that follow. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views and various embodiments. 
         FIG. 1  is an illustration of a perspective view of the front, upper and left sides of a beverage dispenser according to an embodiment of the present invention. 
         FIG. 2  is cut-away view largely along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is a cut-away view of an embodiment of a refrigeration system used in the dispenser of the invention. 
         FIG. 4  is an illustration of a refrigerant circuit of the refrigeration system of  FIG. 3 . 
         FIG. 5  is an exploded, cut-away view of a brazed plate heat exchanger used in an embodiment of the present invention. 
         FIG. 6  is a perspective view of an embodiment of the water delivery system that may function inside the dispenser depicted in  FIG. 1 . 
         FIG. 7  is a perspective view of a flowmeter assembly according to an embodiment of the present invention. 
         FIG. 8  is an exploded side view of the flowmeter of  FIG. 7 . 
         FIG. 9  is a perspective view of the dispenser embodiment depicted in  FIG. 1  with its front door removed and with part of the production line inside the dispenser in an exploded view on the right. 
         FIG. 10  is a cut-away view of part of the concentrate delivery system depicted in  FIG. 9  and a perspective view of the mixing nozzle depicted in  FIG. 9  before it is placed inside the mixing housing. 
         FIG. 11  is a detailed, perspective view of a concentrate discharge tube, a piston, and the mixing nozzle in their assembled positions according to the embodiment depicted in  FIG. 9 . 
         FIG. 12  is a perspective view of the side and the top of an embodiment of the piston. 
         FIG. 13A  is a perspective view of the side and the top of an embodiment of a mixing nozzle. 
         FIG. 13B  is another perspective view of the side of the mixing nozzle depicted in  FIG. 13A . 
         FIG. 13C  is a cross sectional view of the embodiment shown in  FIG. 13B  along the line  13 C- 13 C. 
         FIG. 14A  is a top view of an embodiment of an adapter panel according to an embodiment of the invention. 
         FIG. 14B  is a bottom view of the adapter panel of  FIG. 14A . 
         FIG. 15  is a cross-sectional view of the mixing nozzle of  FIG. 13A  engaged with the adapter panel of  FIG. 14A  in a beverage dispenser at an unlocked position, according to a principle of the invention. 
         FIG. 16  is a perspective view of mixing nozzle of  FIG. 13A  engaged with the adapter panel of  FIG. 14A  in a beverage dispenser at a locked position, according to a principle of the invention. 
         FIG. 17  is a perspective view of part of the front of the dispenser with the front door open to reveal a data input system. 
         FIG. 18  is a formulaic representation of the content of a label associated with each concentrate package, according to an embodiment of the invention. 
         FIG. 19  is block diagram depicting operational steps involving an operator and the control system of the dispenser, according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Features of the invention may work by itself or in combination as shall be apparent to by one skilled in the art. The lack of repetition is meant for brevity and not to limit the scope of the claim. Unless otherwise indicated, all terms used herein have the same meaning as they would to one skilled in the art of the present invention. 
     The term “beverage” as used herein refers to a liquid or a semi-liquid for consumption, and includes but are not limited to, juices, syrups, sodas (carbonated or still), water, milk, yoghurt, slush, ice-cream, other dairy products, and any combination thereof. 
     The terms “control system,” “control circuit” and “control” as a noun are used interchangeably herein. 
     The term “liquid” as used herein refers to pure liquid and a mixture where a significant portion is liquid such that the mixture may be liquid, semi-liquid or contains small amounts of solid substances. 
     The present invention provides a liquid or semi-liquid dispenser that refrigerates a liquid flow inside the dispenser on demand. By “on demand,” it is meant to refer to the capability for chilling a target without significant delay. Typically for a beverage dispenser, e.g., those used in the quick service restaurants, fluid flows inside the dispenser are intermittent. The beverage flow may be almost continuous during meal hours, but may have extended idle time up to hours during slow time. Existing beverage dispensers that use a cold reserve such as an ice bank necessitate constant replenishing of the reserve as the reserve constantly dissipates heat, a wasteful system that often requires constant maintenance and service by human operators. 
     To be able to handle both the busy and slow hours in usage without constantly wasting energy, a desirable refrigeration system needs a high degree of efficiency in the heat-exchange section of the refrigeration system. The present invention provides such a refrigeration system designed to function in a liquid dispenser. Examples of such a liquid dispenser are now described. 
     Referring to  FIG. 1 , a postmix beverage dispenser  50  according to one embodiment of the present invention is illustrated. The beverage dispenser  50 , viewed from outside, includes a housing  52  that has a hinged front door  54 . The housing  52  further includes a platform or drip tray  56  for placing receptacles  58  such as cups of various sizes that receive the postmix products. Dispense buttons  60   a  and  60   b  may be situated at various locations on the housing  52  for an operator to initiate a dispensing cycle. In the particular embodiment illustrated in  FIG. 1 , one set of the dispense buttons,  60   a  or  60   b , is situated on either side of the drip tray  56  to control dispensing of the product from either dispensing nozzle (not shown). To have the dispense buttons at a location other than the front door  54 , makes it easier for wiring, and also the buttons remain visible and accessible to the operator while the front door  54  is open. 
     The dispensing buttons  60   a  and  60   b  may include, as in the example illustrated, buttons corresponding to various portion sizes, e.g., small, medium, large and extra large. The buttons may also include those that allow the operator to cancel/interrupt a dispensing cycle that has started, or to manually dispense while the button is pressed (“top-off” or “momentarily on”). They may also include lights that indicate the status of the machine. The dispensing buttons  60   a  and  60   b  may be back-lit to enhanced visibility, and may be part of a larger display (or interface) that provides further information on the dispenser. 
     Still referring to  FIG. 1 , a display  62 , e.g., a liquid crystal display, is illustrated underneath the drip tray  56  and on the dispenser housing  52  for displaying information pertaining to the machine. Such information may include error messages, status, diagnostic messages, operational instructions, and so on. Similar to the dispense buttons, having the display  62  off the front door  54  can be advantageous in terms of wiring and functionality. Other parts of the dispenser housing  52  may include metallic panels  64  with slots  66  for air intake needed for the refrigeration system. 
     Referring now to  FIG. 2 , a cut-away view of the dispenser  50  reveals its various inner parts. Inside the housing  52  and behind the front door  54  is a concentrate cabinet  68  (or compartment) for placing a prepackaged supply of concentrate and for mixing the concentrate with a diluent before dispensing. In one embodiment, the cabinet  68  houses at least one, preferably two, concentrate holders  70 , one of which is shown in the drawing. A prepackaged supply (not shown) of concentrate (or additive, solute) is stored inside the concentrate holder  70  and a drainage tube  72  from the concentrate supply is fed into a concentrate delivery system  74 , which in turn, delivers the concentrate into a mixing and dispensing system  76 . Diluent (or solvent), typically a potable liquid, e.g., potable water, carbonated or non-carbonated, is supplied through a separate delivery system, e.g., a water delivery system  78 , into the mixing and dispensing system  76 . Postmix product is eventually dispensed through a mixing nozzle  80  into the receptacle  58 . 
     Still referring to  FIG. 2 , the beverage dispenser  50  also includes a refrigeration system  82  that provides the necessary refrigeration to chill the concentrate cabinet  68  and water supplied through the water delivery system  78 . In one embodiment, a control system  84  is provided to monitor, regulate and control the operation of various systems inside the dispenser  50 , such as the refrigeration system  82 , the concentrate delivery system  74 , the water delivery system  78 , and the mixing and dispensing system  76 . The control system  84  may also provide error diagnostics for a service technician or operator. 
     A power switch  85  is located on the dispenser housing  52 , specifically, outside of the drip tray  56  in the illustrated embodiment. A plug  86  at the back of the dispenser housing  52  connects systems that require power to an outside power source. Various parts, for example, of the water delivery system  78  and/or refrigeration system  82 , are wrapped in insulation materials  88 . 
     In a preferred embodiment, one beverage dispenser  50  contains at least two production lines such that most of the parts described above in reference to  FIG. 2  are duplicated side-by-side in the same dispenser housing  52 . For example, two sets of concentrate holders  70 , concentrate delivery systems  74 , parts of the water delivery systems  78 , mixing and dispensing systems  76  may be manufactured to fit into one dispenser  50 . The refrigeration system  82  is also bifurcated where necessary to chill both production lines. With two production lines, an operator has the choice of providing two different postmix products through the same dispenser. In one embodiment, the footprint or dimension of the dispenser  50  is no larger than about 11 inches (about 28.0 cm) wide, about 25 inches (63.5 cm) deep and about 55 inches (88.9 cm) tall. To save space, various individual parts inside the dispenser  50  may be designed as integrated modules to reduce extraneous connecting or sealing parts and to make it easier for service. 
     Features of the present invention are further illustrated by the following non-limiting examples. 
     Refrigeration System 
     Referring now to  FIG. 3 , an embodiment of the refrigeration system  82  according to the present invention is illustrated. In one embodiment, the refrigeration system  82  includes one or more evaporators, a compressor  90 , a condenser  92 , a fan  94 , an air filter  96 , a dryer  98 , and one or more optional temperature sensors, parts generally known to one skilled in the art. Under the control of the control system  84 , the refrigeration system  82  cools both the concentrate cabinet  68  and the water delivery system  78 . In one embodiment, the control system  84  is programmed to prevent use of the refrigeration system  82  if the filter  96  is not installed. This prevents the fan  94  from engaging and, consequently, protects the condenser  92  from contamination by unfiltered air flow. A simple reed switch next to the filter  96  providing feedback to the control system  84  is able to accomplish this. Furthermore, in order to provide refrigeration to the water delivery system  78  on demand, the present invention includes a plate heat exchanger, for example, a brazed plate heat exchanger (BPHX)  100 , in its refrigeration system  82 . 
     An illustrative refrigerant circuit is shown in  FIG. 4 , where the refrigerant flows through the compressor  90 , the condenser  92  next to the fan  94 , and various valves  102  including solenoid valves that direct the flow of the refrigerant. The circuit includes a primary loop  104  that chills the water supply and a secondary loop  106  that chills the concentrate cabinet  68 . 
     In one embodiment, the primary loop  104  lowers the water supply, e.g., a pressurized water supply at a flow rate of about 4 ounces (about 0.12 liters) per second or about 2 gallons (about 3.8 liters) per minute, by at least 5° F. (about 2.8° C.), or preferably, 10° F. (about 5.6° C.). And the secondary loop  106  keeps the concentrate cabinet at or below 40° F. (about 4.4° C.). In one feature, in order to guarantee almost instant chilling of the water supply, the primary loop  104  and the secondary loop  106  are never activated simultaneously—only one loop is being activated at any given time. And the primary water loop  104  always has priority over the secondary cabinet loop  106 . In another feature, water from the beverage tower or a water booster/chiller system is channeled to flow in and out of the BPHX  100  for maximum efficiency in heat exchange. 
     Referring now to  FIG. 5  where the BPHX  100  is illustrated in an exploded cut-away view. The BPHX  100  comprises multiple corrugated layers of thin stainless-steel plates  108  that are gasketed, welded, or brazed together. Such BPHX are commercially available, for example, from Alfa Laval Corporation. In one embodiment, the BPHX  100  is brazed with copper or nickel materials, and called copper brazed plate heat exchanger. In another embodiment, the BPHX  100  is a stainless steel brazed plate heat exchanger. The corrugated BPHX plates  108  provide maximum amount of heat-exchange surfaces as a water conduit  110  formed on one plate is situated next to a refrigerant conduit  112  formed in a neighboring plate. 
     Both the refrigerant and the water are controlled by solenoids such that the water will only flow through the BPHX  100  when the refrigerant is flowing, and vise versa, creating instant yet energy-conserving heat transfer. In one embodiment, water and refrigerant flow in a co-flow pattern, which means they both flow from one side of the exchanger, top or bottom, to the other. In a preferred embodiment, water and refrigerant flow in a counter-flow pattern, where warm water flows in from the top of the exchanger and cold refrigerant flows in from the bottom of the exchanger. As a result, as the water is chilled, it passes by even colder refrigerant as it progresses through the exchanger, forcing a rapid decrease in the water temperature. As a result, the refrigeration system of the present invention is capable of chilling a water flow on demand without the use of a cold reservoir such as an ice bank. In other words, the refrigeration system operates in an ice-free environment. 
     To prevent accidental freeze-up of the water circuit, the control system of the dispenser is programmed to prevent actuation of the refrigeration system before a sufficient amount of water has entered the circuit. For example, if the BPHX holds 12 ounces (about 0.35 L) of water, and it is determined that, from the point where water flow is measured (e.g., at a rotameter), at least 21 ounces (about 0.62 L) of water is needed to ensure the water conduit inside the BPHX is filled up, the control system will be programmed to mandate 21 ounces (about 0.62 L) of water has passed through the rotameter in each power cycle before energizing the primary water chilling loop of the refrigeration system. 
     Referring back to  FIG. 4 , the secondary cabinet loop  106  of the refrigeration system  82  can utilize any of the conventional refrigeration technique, e.g., the cold-wall technology, to chill the concentrate cabinet  68 . Because the dispenser stores and makes products for consumption, it is important to maintain the concentrate cabinet  68  at a temperature that substantially inhibits growth of potentially harmful bacteria, e.g., at or below 40° F. (about 4.4° C.). In one embodiment, the secondary cabinet loop  106  utilizes a capillary tube refrigerant control scheme since the load on the system is fairly constant. 
     Diluent Delivery System 
     Referring to  FIG. 6 , an embodiment of the water delivery system  78  is illustrated. Potable water is introduced into the delivery system  78  at an inlet  114  at the back of the dispenser. The inlet  114  is fitted to allow a 0.5 inch (1.27 cm) NPT (National Pipe Tap) inlet connection to an outside source of water supply, e.g., an in-store water chiller/booster system. The incoming water may be boosted, e.g., to about 20 to 100 psi (pound per square inch), and pre-chilled to about 45° F. (about 7.2° C.). The water deliver system  78 , in one embodiment, provides pressurized water flow as the master in a “master-follower” mixing system. Such a system regulates the rate of delivery for the follower, the concentrate in this case, based on that of the master, water in this case, and therefore, only actively adjusts the rate for one of two ingredients. The water delivery system  78  may also, in corroboration with the refrigeration system  82 , provides further chilling of the incoming water, e.g., by an additional 5° F. (about 2.8° C.) to 40° F. (about 4.4° C.). For that reason, parts or all of the water delivery system  78 , including water conduits  116   a  and  116   b , are insulated. 
     Still referring to  FIG. 6 , the water delivery system  78  continues as water conduit  116   a  passes through an optional pressure regulator  118 . The pressure regulator  118  may adjust the water flow to a desired pressure and flow rate, e.g., less or at about 30 psi and about 2 gallons (about 3.8 L) per minute. Pressure-adjusted water is then fed into part of the refrigeration system  82 , specifically, the BPHX  100 . Further chilled water exits the BPHX  100  into the conduit  116   b . Because the illustrated embodiment has two production lines from two sources of concentrate supply, water is bifurcated here and flows into two flowmeter assemblies  120   a  and  120   b  before entering respective mixing and dispensing systems  76   a  and  76   b , and dispensed as part of the final products eventually. 
     Referring now to  FIG. 7 , the flowmeter assembly  120  is designed to minimize extraneous parts, connectors and fixtures while combining the functions of flow control and monitoring into one assembly. In one embodiment, the flowmeter assembly  120  includes a manifold  122  inside an integral housing  123  that has a first arm  124  and a second arm  126 . The first arm  124  provides at least one inlet port  128  for fluid input, and the second arm  126  provides at least one outlet port  130  for fluid output. The inlet port  128  is in fluid communication with the outlet port  130  through a bore (not shown). The orientation of the second arm  126  determines the direction of fluid output. In one embodiment, the second arm  126  is constructed along an axis that is about 45 to 60 degrees to the axis of the first arm  124 . 
     Referring still to  FIG. 7 , a flowmeter or rotameter (not shown) is embedded or otherwise integrated in the first arm  124  of the manifold housing  123 , downstream to the inlet port  128  and upstream to the outlet port  130 . The flowmeter responds to any fluid flow by generating an analog output signal indicative of the rate of the fluid flow. Next to the flowmeter on the first arm  124  is an adapter  132  configured and sized for a flowmeter sensor  134  to fit in its groove. The flowmeter sensor  134  senses the output signal generated by the flowmeter and relays through wiring  136  to a control system. The control system uses this information to set the pace of a concentrate pump to achieve a desired concentrate ratio as explained in a subsequent section. To ensure accurate reading, upstream to the flowmeter, an optional pressure-compensated flow control valve (not shown) may be incorporated in the first manifold arm  124  to regulate water flow into the flowmeter. The pressure-compensated flow control valve is preferably a one-way valve. Additionally, another one-way valve, e.g., a check valve (not shown), may optionally be embedded in the second housing arm  126  to prevent any substantial fluid flow back toward the flowmeter. Backflow from the mixing system may contaminate the flowmeter and prevent it from proper functioning. 
     Still referring to  FIG. 7 , in order to minimize the amount of connecting parts in the water delivery system, the ports of the flowmeter assembly  120  are equipped with furnishings that allow the assembly to sealingly receive upstream and downstream conduits, preferably of a standard size, e.g., 0.5 inch (1.27 cm) in diameter. Specifically, the inlet port  128  and the outlet port  130  are furnished with connector assemblies  138  and  140 , respectively. 
     The flowmeter assembly  120  further includes a gate-keeping valve, e.g., a solenoid valve  142  sealingly fastened to the manifold housing  123  and situated downstream to the flowmeter and upstream to the outlet port  130 . The solenoid valve  142  is capable of shutting off and reopening the water flow, and is needed to control water flow from the BPHX to the mixing system. In the illustrated embodiment, the solenoid valve  142  is pre-fabricated and then fastened onto the manifold housing  123  though a screw  144 . 
     Referring now to  FIG. 8 , more details of the flowmeter assembly  120  are illustrated in an exploded view. To manufacture the assembly  120 , in one method, a pressure-compensated flow control valve  145 , a flowmeter  146  with a turbine  148 , and a check valve  150 , all commercially available, are provided. Then, the manifold housing  123  can be fabricated, e.g., through injection molding using an NSF-listed food-grade thermoplastic, while assembling therein the pressure-compensated flow control valve  145 , the flowmeter  146 , the check valve  150 , arranged sequentially down a fluid flow along the bore of the manifold. For the particular manifold configuration illustrated herein, a port plug  152  is used to seal up a reserve port  153  on the housing  123 . A commercially available solenoid valve  142  is then fastened to the manifold housing  123  through a two-way bolt screw  144  and a top nut  154 . 
     Still referring  FIG. 8 , connector assemblies  138  and  140  may be furnished to the inlet port  128  and the outlet port  130 , respectively, after the manifold housing  123  has been fabricated. In one embodiment, the connector assembly is a quick disconnect fitting, and may include an expandable member configured to fit inside the port for sealingly receiving a connective conduit. As illustrated herein, each of the connector assemblies  138  and  140  may include a barbed expandable member  156  with an external o-ring  158  for sealing. In one embodiment, the expandable member  156  comprises multiple extensions arranged in a circle and separated by slots. For example, this kind of connector assembly is commercially available from Parker Hannifin Corporation of Ravenna, Ohio, under the trademark TrueSeal. Again, a flowmeter sensor  134  can be fastened to the flowmeter assembly  120  through an adapter structure  132  on the manifold housing  123 . 
     By integrating multiple components such as the pressure-compensated flow control valve, the flowmeter (and/or its sensor adapter), the solenoid valve, and the check valve into one manifold-based assembly, the present invention economizes all these parts into one easily serviceable assembly with only two openings. Further, the assembly is designed such that those limited number of openings can be furnished with connectors than can sealingly connect to other conduits though simple axial motions without the help of any tools, further enhancing serviceability. An integrated assembly also makes it easier to fabricate closely-molded insulation wrap or casing around it. 
     Concentrate Delivery System 
     Referring to  FIG. 9 , in one embodiment of the invention, the concentrate delivery system  74  delivers the concentrate from a reservoir into the mixing and dispensing system  76  where the concentrate meets the diluent, e.g., potable water, and the two are blended together before being dispensed.  FIG. 9  shows the dispenser embodiment  50  of  FIGS. 1 and 2  with the front door removed, and one of the two parallel production lines is depicted in a partly exploded view. 
     The concentrate, which may be liquid or semi-liquid and may contain solid components, e.g., juice or syrup concentrates with or without pulp, slush, and so on, is loaded into the concentrate cabinet  68  in a package. The package may be a flexible, semi-rigid or rigid container. A concentrate holder  70  may be provided to accommodate the concentrate package. In one embodiment, the concentrate holder  70  is a rigid box with a hinged lid that opens to reveal a ramp  162 , separate or integrated with the holder housing, to aid drainage of the concentrate from its package. The ramp  162  can be flat or curved for better accommodation of the package. The concentrate holder  70  may also have corresponding ridges  164  and grooves  166  on its housing, e.g., the lid  160  and its opposite side  168 , to aid stacking and stable parallel placement. The concentrate holder  70  may also have finger grips or handles that are easily accessible to an operator from the front of the concentrate cabinet  68  to aid the holder&#39;s removal. For example, a vertical groove  165  near an edge of the holder  70  could serve that function. 
     Referring to both  FIGS. 9 and 10 , the concentrate package comes with a drainage tube  72  that is lodged in an opening  170  at the bottom of the concentrate holder  70 . The concentrate holder  70  may include a protrusion or similar structure to facilitate the locking of the drainage tube  72  in a preferred locking position in the opening  170  to prevent kinking or misalignment that hinders pump operation. Further, such a locking position may ensure proper functioning of a sensor that monitors the liquid flow inside the drainage tube. The drainage tube  72  extends out of the concentrate holder  70  and is attached to a tube adapter  171  on the top of a pump head  172 . Underneath the tube adapter  171  is an elongated cylindrical piston housing  176  inside which a piston  177 , actuated by a rotary shaft (not shown) powered by a motor  181 , moves to transfer the concentrate from the tube adapter  171  to a mixing housing  178 . Inside the mixing housing  178  are portions of a mixing nozzle  80  of which the top surface  182  forms a mixing chamber  184  with the top inner surface of the mixing housing  178 . Water is also delivered into the mixing chamber  184  where mixing takes place. The reconstituted product is then dispensed through the discharge outlet  186  of the mixing nozzle  80 . 
     Still referring to both  FIGS. 9 and 10 , the pump head  172  is mounted onto an adapter plate  188  through a locking ring  190 . In one embodiment, the locking ring  190  has a feedback structure that ensures the locking ring  190  is in the proper locking position. As a result, the dispenser machine  50  is not energized unless the pump head  172  and the locking ring  190  are properly assembled. An example of such a feedback structure is a magnet  192  that activates a reed switch  194  ( FIG. 10 ) placed behind the adapter plate  188  at a position that corresponds to the proper locking position of the magnet  192 . 
     Referring now to  FIG. 11 , in a more detailed view, the piston  177  is shown to extend out of an upper opening  196  of the adapter plate  188 . The piston  177  has a U-shaped depression  180  (better illustrated in  FIG. 12 ) that temporarily holds concentrate during its operation. Still referring to  FIG. 11 , as the piston  177  transfers the concentrate from the drainage tube  72  towards nozzle top surface  182 , pressurized and chilled water is forced out of a lower opening  198  of the adapter plate  188  to mix with the concentrate. The blended product then flows through an opening  202  in the nozzle top surface  182 . 
     According to one feature of the invention and referring back to  FIG. 10 , the piston  177  is, for example, part of a positive displacement pump, e.g., a nutating pump or a valveless piston pump, such as those commercially available from Miropump Incorporated of Vancouver, Wash. Nutation is defined as oscillation of the axis of any rotating body. Positive displacement pumps are described in detail in co-owned U.S. application Ser. No. 10/955,175 filed on Sep. 30, 2004 under the title “Positive Displacement Pump” and its entire disclosure is hereby incorporated by reference wherever applicable. The depicted nutating pump is a direct drive, positive displacement pump used to move liquid from a starting point, in this case, the tube adapter  171 , to a destination, here, the mixing chamber  184 . The piston  177  is configured to rotate about its axis, so that its U-shaped depression  180  faces upward towards the tube adapter  171  to load the concentrate and faces downward towards the mixing chamber  184  at the end of one cycle to unload its content. Meanwhile, the piston  177  also oscillates back and forth in the direction indicted by the arrow  204 , providing additional positive forces to transfer the concentrate. 
     One advantage for employing positive displacement pumps, such as a nutating pump or a valveless piston pump as opposed to progressive cavity pumps or peristaltic pumps is the enhanced immunity to wear or variation in concentrate viscosity. Prior art pumps often suffer from inconsistency in delivery due to machine wear or the need for a break-in period; they also face low viscosity limits because concentrates of higher viscosity requires greater power in those pumps. In contrast, positive displacement pumps can deliver, with consistency and without the need for speed adjustment, concentrate loads over a wide range of viscosities. Accordingly, to deliver a predetermined amount of concentrate, one only needs to set the pump speed once. 
     In one embodiment, the pump is equipped with an encoder to monitor the number of piston revolutions—e.g., each revolution may be equal to 1/32 of an ounce (about 0.0009 L) of the concentrate. The encoder may be placed on the rotary shaft of the pump motor to count the number of revolutions the piston has turned in relation to the water flow. The number of pump revolutions is dictated by the control system based on two pieces of information: a predetermined, desired mix ratio between the concentrate and the water, and the amount of water flow sensed by the flowmeter assembly described above. 
     Still referring to  FIG. 10 , optionally, the controller system may be programmed to ensure that the pump piston  177  is returned to the intake position at the end of each dispense operation. By having the piston positioned at the intake stroke with its U-shaped depression facing upward, the entry point to the mixing chamber  184  for the concentrate will be completely sealed to prevent any leakage of concentrate. This also allows water, which enters the mixing chamber  184  at the port  206  from the water delivery system  78 , to flush and clean the outlet of the pump and the mixing chamber  184  during and after each dispensing cycle. 
     Mixing and Dispensing System 
     The mixing and dispensing system  76  provides a common space for the concentrate and the diluent to meet and blend. The mixing and dispensing system  76  also includes parts that facilitate the blending. Referring back to  FIG. 9 , in one embodiment, the mixing and dispensing system  76  includes the mixing housing  178  and the mixing nozzle  80 . As described earlier, top portions of the mixing nozzle  80  fit into the mixing housing  178  and forms the mixing chamber  184  ( FIG. 10 ) therebetween. In one embodiment, the mixing housing  178  is fabricated as part of the pump head  172 . 
     Referring now to  FIG. 11 , according to one feature of the invention, a barrier structure or diverter  200  on the nozzle top surface  182  faces an incoming diluent stream and forces the diluent to spray into an incoming concentrate stream being unloaded by the piston  177 . In an example where the diluent is water, the incoming water stream enters the mixing chamber through a lower plate opening  198  and then a water entry port  206  ( FIG. 10 ) in the mixing chamber housing  178  ( FIG. 10 ). The turbulence created by the redirected water flow continues through the entire dispensing cycle and effectively produces an evenly and thoroughly blended mixture of the concentrate and the water. 
     The mixture then flows through the opening  202  in the nozzle top surface  182  and passes through the rest of the mixing nozzle  80  before emerging out of the discharge outlet  186  ( FIG. 9 ). In one embodiment, a mixture of concentrate and water is kept in the mixing chamber after dispensing a requested product for a “top off” operation. 
       FIGS. 13A ,  13 B, and  13 C depict one embodiment of the mixing nozzle  80  according to the invention. A nozzle body  189  has an inlet section  191 , an outlet section  195  and a depressurizing section  193  in between. The nozzle body  189  extends along a rotational axis  197 , and defines a liquid passageway  199  from the inlet section  191  to the outlet section  195 . The inlet section  191  consists of a nozzle top  261  and the barrier structure or diverter  200  thereon. The depressurizing section  193  consists of a depressurizing chamber  263  in between the nozzle top  261  and a chamber floor  264 . The depressurizing chamber  263  may be partitioned, in part, by multiple walls  266  into multiple chambers. In each chamber, there is an elongated diffusion slot  268  on the chamber floor  264  near the floor&#39;s periphery. There can be any number, e.g., four, of these diffusion slots, and two of them, labeled  268   a  and  268   b , are depicted in the drawings. Compared to the inlet opening  202 , these diffusion slots  268  are further away from the nozzle axis  197  to direct the liquid flow towards the nozzle periphery. 
     Still referring to  FIGS. 13A to 13C , the diffusion slots  268  lead into a funnel  270  (best viewed in  FIG. 13C ) defined by the nozzle outlet section  195 . A funnel, as used herein, refers to a structure that defines a passage where the cross section of one end is larger than the other; a funnel&#39;s diameter may continually taper toward one end, or the tapering may be interrupted by sections where the diameter is unchanged. In the illustrated embodiment, the funnel  270  includes an inner wall  272  that, from the top to bottom, have a constant diameter at first, and then continually tapers toward the edge  274  of the discharge outlet  186 . 
     Specifically referring to  FIG. 13C , the nozzle&#39;s liquid passageway  199  begins at the inlet opening  202  on the nozzle top surface  182 . The nozzle top surface  182  serves as the floor of the mixing chamber when the nozzle body  189  is partly inserted in the mixing housing. While the nozzle top surface  182  can be flat, in a preferred embodiment, it is slightly curved with the inlet opening  202  at the lowest point of the floor to aid gravitational drainage. The initial portion of the nozzle passageway  199  is an inlet channel  262  of constant diameter that extends from the inlet opening  202  through the nozzle top  261  and into the depressurizing chamber  263 . In one embodiment, the inlet opening  202  is designed to be fairly restricted compared to the size of the nozzle top surface  182 , so that when the postmix product flows through the inlet channel  262  and enters the depressurizing chamber  263 , the substantial increase in the average cross-sectional area of the liquid passageway  199  greatly reduces the pressure and hence the momentum of the liquid flow. The pressure drop induced by the depressurizing chamber  263  serves to reduce splashing in dispensing the product. In one embodiment, the depressurizing chamber  263  has a cross-sectional area that is at least 20 times, preferably 50 times, and more preferably 100 times larger than that of the inlet channel  262 . In one embodiment, the inlet opening  202  has a diameter of 0.125 inches (about 3.2 mm) and the depressurizing chamber  263  has a diameter of 1.375 inches (about 3.5 cm), therefore an 121 times increase in cross-sectional area. 
     Both the nozzle top  261  and the chamber floor  264  have a groove around its periphery that each accommodates an o-ring  276   a / 276   b . The o-rings seal against the inside of the mixing housing when the nozzle body  189  is locked in. 
     Still referring to  FIG. 13C , the last portion of the nozzle passageway  199  consists of the funnel  270 . The diffusion slots  268  that lead to the funnel can be of a variety of shapes, including oval, kidney bean-shaped, circular, rectangular, fan-shaped, arc-shaped and so on. The diffusion slots  268  are situated along the edge of the chamber floor  264  to direct the product flow toward the inner funnel wall  272 . As the product streams down the funnel wall  272  as opposed to free fall in the middle of the passageway  199 , splashing is further reduced. The increase in cross-sectional area of the flow path as it enters from the diffusion slots  268  into the funnel  270  also tend to slow down the flow. The shape of the funnel  270  as a large portion of it continually tapers down towards the bottom edge  274  also tends to create a spiral flow pattern as the flow is re-centered toward the nozzle axis  197 . A centered product stream makes it easier to receive the entire product in the waiting receptacle. 
     Sections of the nozzle body  189  as well as other distinct structures described herein may be fabricated separately and assembled before use, or, fabricated as one integrated piece. The nozzle body  189  should be sized such that at least the inlet section  191  and the depressurizing section  193  fit into a nozzle housing, e.g., the mixing housing  178  ( FIG. 10 ). The nozzle may be manufactured in a variety of food-safe materials, including stainless steel, ceramics and plastics. 
     Referring back to  FIGS. 13A ,  13 B, and  13 C, the diverter  200  provides an elevated blocking surface  201  that redirects an incoming water stream. The diverter  200  is depicted as substantially cylindrical, but one skilled in the art understands that it can be of any of a variety of geometrical shapes. The blocking surface  201  is designed to maximize contact between water and the concentrate. In this case, it changes the direction of a pressurized water stream so that the water stream meets the incoming concentrate stream head on, i.e., the two streams meet at a degree close to 180 degrees, or at an obtuse angle. Referring back to  FIG. 11 , the blocking surface  201  creates a spray pattern as it redirects water so that water molecules bounce off the surface in a variety of directions as illustrated by arrows  203   a  and  203   b . The incoming concentrate stream moves generally in the direction of gravitational fall as indicated by arrow  205 . The two streams meet at an angle  207 . In one embodiment, the angle  207  is more than 90 degrees, and preferably, more than 120 degrees. 
     The blocking surface  201  may be of a variety of geometry, even or uneven, uniform or sectioned. For example, the blocking surface  201  may be concave or convex, corrugated, dimpled, and so on. In the illustrated embodiment, the blocking surface  201  is a concave surface such that a wide, thin, powerful spray patter of diverted water is generated that cuts into the concentrate stream, and creates turbulent flow pattern inside the mixing chamber. This turbulent pattern results in a uniformly blended product that is then forced into the opening  202  on the nozzle top surface  182 . The edge of the blocking surface  201  may be sharp or blunt. In one embodiment, to avoid injury to the operator, the top of the diverter  200  is flattened or rounded. 
     To ensure that the blocking surface  201  substantially faces the water stream coming into the mixing chamber, i.e., that the nozzle body  189  is locked in a predetermined orientation inside the mixing chamber, certain locking features may be added to the nozzle. Referring to  FIGS. 13B and 13C , in one embodiment, the blocking surface  201  is situated asymmetric about the nozzle axis  197 , therefore, a locking structure that is also asymmetric about the nozzle axis  197  is provided to orient the nozzle. In one embodiment, such locking structure includes an asymmetric collar that is integrated with the nozzle body  189 . Specifically, the asymmetric collar can be a D-shaped collar  278  situated between the chamber floor and a middle collar  280 , and having a flat side  279 . There is a locking groove  282  between the D-shaped collar  278  and the middle collar  280  that will engage an adapter panel as described hereinbelow. Both the D-shaped collar  278  and the middle collar  280  are preferably integrated with the rest of the nozzle body  189 . 
     Still referring to  FIGS. 13B and 13C , another locking structure can be a set of projections that extend along the nozzle axis  197 . In one embodiment, the projections are a pair of wing-like handles  284  and  286  that occupy different latitudinal spans along the outside of the nozzle body  189 . The locking handle  284  extends from just below a lower collar  288  upward and terminates level to the top of the middle collar  280 . The regular handle  286  also extends from just below the lower collar  288  upward, but terminates below the top of the middle collar  280 . 
     The use of the locking structures and the installation of the mixing nozzle are now described. Referring now to  FIGS. 14A and 14B , a corresponding locking structure that facilitates the installation and locking of the mixing nozzle is found in an adapter panel  290 . The adapter panel  290 , in one embodiment ( FIG. 9 ), is fixedly situated behind the front door and underneath the mixing chamber  184 —its spatial relation to the water path is fixed and known. The adapter panel  290  defines one or more openings  292  sized and shaped to let through the asymmetric collar  278  but not the larger middle collar  280  of the nozzle body  189  ( FIG. 13C ). As depicted in the top view provided by  FIG. 14A , in the particular embodiment where the asymmetric collar  278  is D-shaped, so is the adapter opening  292 . 
     Referring to the bottom view of the adapter panel  290  provided by  FIG. 14B , the D-shaped opening  292  is situated inside a largely circular recess such that the recess is a step-down from the rest of the panel  290  and the rim of the D-shaped opening  292  is surrounded by the recess floor  294 . The recess border  296  is sized and shaped to fit the middle nozzle collar  280  snugly. The recess has an arc-shaped locking slot  298  in addition to the circle that fits the middle nozzle collar  280 ; the locking slot  298  is designed to dictate the locking and unlocking sequence in cooperation with the locking handle  284  ( FIG. 13C ). Specifically, the locking slot  298  is sized such that the top of the locking handle  284  fits snugly in the slot and can rotate back and forth between one side  299  of the slot and the other side  300 , rotating the rest of the nozzle body with it. 
     In operation, referring to both  FIGS. 13B and 14B , the nozzle inlet section  191  and the nozzle depressurizing section  193  are inserted from under the adapter panel  290  through the opening  292 . Because of their asymmetric shapes, the flat side  279  of the D-shaped collar  278  must align with the flat side  297  of the opening  292 . The middle nozzle collar  280  will not be able to go through the adapter opening  292 , but will rest inside the panel&#39;s recess border  296  against the recess floor  294 . At this point, the nozzle body  189  is at an unlocked position with the locking handle  284  rested against the “unlocked” side  299  of the locking slot  298 . The unlocked position is depicted in  FIG. 15  which shows the adapter panel  290 &#39;s recess floor  294  engaged inside the locking groove  282  between the nozzle D-shaped collar  278  and the nozzle middle collar  280 , and the locking handle  284  toward the very back of the mixing chamber  184 . 
     Referring back to  FIGS. 13B and 14B , the orientation of the locking slot  298  dictates that the locking handle  284  can only rotate counterclockwise (note that  FIG. 14B  is a view from the bottom) until it is stopped at the “locked” side  300  of the locking slot  298 . The locked position is depicted in  FIG. 16  in which the elevated blocking surface  201  faces directly at the water stream entering from the direction of the opening  198 . To unlock the nozzle, simply reverse the above-described sequence of motion by turning the handles  284  and  286  clockwise until they stop at the unlocked position depicted in  FIG. 15 . The operator can then use the lower nozzle collar  288  as a gripping aide to pull the nozzle body  189  downward out of the opening  292  in the adapter panel  290 . 
     Control System 
     To monitor and control the operation of various systems inside the dispenser, a control system is provided. The control system may include a microprocessor, one or more printed circuit boards and other components well known in the industry for performing various computation and memory functions. In one embodiment, the control system maintains and regulates the functions of the refrigeration system, the diluent delivery system, the concentrate delivery system, and the mixing and dispensing system. More specifically, the control system, with regard to:
         refrigeration system: monitors filter placement, activates water chilling loop, supports water chilling loop over cabinet chilling loop;   diluent delivery system: regulates one or more gate-keeping switches that control the water flow at various points, regulates pressure of the water flow; receives and stores flow rate output;   concentrate delivery system: monitors pump head lock, receives and stores information regarding the concentrate including desired mix ratio of the product, ascertains concentrate status, computes and regulates pump speed and fill volumes, controls piston position;   mixing and dispensing system: activates cleaning of the system, dispenses the right fill volumes; and   diagnostics: identifies errors and provides correctional instructions.       

     The above outline is meant to provide general guidance and should not be viewed as strict delineation as the control system often works with more than one system to perform a particular function. In performing refrigeration-related functions, the control system, as described earlier, ensures that the refrigeration system cannot be energized if the filter is not properly installed. In that case, the control system may further provide a diagnostic message to be displayed reminding an operator to install the filter. The control system further monitors, through output signal from the flowmeter, the amount of water that has passed through the flowmeter, and allows the activation of the primary water chilling loop only after sufficient amount of water, e.g., 21 ounces (about 0.62 L), has passed to prevent freeze-up of the water circuit. 
     Once the primary water chilling loop has been activated, however, the control system will support its function over secondary cabinet chilling loop. The control system also ensures that only one refrigeration loop is energized at any given time, and that the cabinet chilling loop is energized when the cabinet is above a predetermined temperature. 
     The diluent delivery system may include gate-keeping switches such as solenoid valves at various points along the water route. The control system controls the operation of these switches to regulate water flow, e.g., in and out of water chilling loop, specifically, as water enters and exits the BPHX. The control system also regulates the pressure of the water flow, through pressure regulators, for instance. Output signals from the flowmeter are sent to the control system for processing and storage. 
     In each dispensing cycle, once a portion size has been requested, the control system determines when the request has been fulfilled by reading the water flow from the flowmeter and adding the volume dispensed from the concentrate pump. Each of the portions will be capable of being calibrated through a volumetric teach routine. Provisions to offset the portion volume for the addition of ice may be incorporated into the control scheme. 
     With regard to the concentrate delivery system, the control system ensures that no dispensing cycle starts if the pump head is not properly assembled through the locking ring, as described earlier. The control system, following the master-follower plan where water is the master and the concentrate is the follower, regulates the pump speed based on computed fill volumes and detected water flow rate to achieve a desired mix ratio. Unlike some of the prior art control mechanisms where both the concentrate flow and the diluent flow are actively regulated, the control scheme of the present invention only actively adjusts one parameter (pump speed), making the system more reliable, easier to service, and less prone to break-down. At the end of each dispensing cycle, the control system ensures that the piston in the concentrate pump is returned to the intake position so that a seal is effectively formed between the concentrate delivery system and the mixing and dispensing system. 
     Referring now to  FIG. 17 , to provide the control system with information regarding a package of concentrate as it is loaded into the dispensing system, the present invention provides a data input system. The system includes a label  208   a  or  208   b  and a label reader  210  installed in the dispenser  50 . The label reader  210  may be an optical scanner, e.g., a laser scanner or a light-emitting diode (LED) scanner. In one embodiment, the label reader  210  is an Intermec® E1022 Scan Engine, commercially available from Intermec Technologies Corporation, housed behind a protective cover. In another embodiment, the data input system employs radio frequency identification (RFID) technology and the label reader  210  is a radio frequency sensor. The label  208   a  is detachably affixed to the concentrate drainage tube  72 , which is preferably made of a pliable material, in the form of a tag, tape, sticker, chip, or a similar structure, while label  208   b  is permanently associated with, e.g., directly printed onto, the concentrate drainage tube  72 . In one embodiment, the label  208   a  is made of waterproof mylar and backed with adhesive. The label  208   a  or  208   b  each includes certain information in a machine-readable form  212  regarding the particular concentrate package that the label is associated with. The machine-readable form  212  may be optically, magnetically or electronically or otherwise readable. In one embodiment, the machine-readable form  212  is readable by radio frequency. The information may include: data on desired compositional ratio between the concentrate and the diluent in the postmix product, whether the product requires a low (product with ice) or high (product without ice) fill volume of the concentrate for any given portion size, the expiration date to ensure food safety, flavor identity of the concentrate, and so on. In a preferred embodiment, the label includes some unique information about each package, such that a unique and package-specific identifier can be generated. For example, the label may indicate when the concentrate was packaged up to the second, which would typically be unique for each package. 
     Referring now to  FIG. 18 , in an example of the label, the data is presented in a barcode that corresponds to the parameters represented graphically herein. Specifically, the first data set  214  represents the packaging date “January 7, 2000.” The second data set  216  represents the packaging time in the format of “hour-minute-second” (the illustrated example uses a random integer of five digits). The third data set  218  represents an indicium for a desired compositional ratio between a diluent and the concentrate in the postmix product, as in this particular example, 5:1. The fourth data set  220  represents the expiration date of the package “January 26, 2000.” The fifth data set  222  represents ice status, i.e., whether ice is typically added to the postmix product derived from this concentrate. The sixth data set  224  represents concentrate&#39;s flavor identity, in this case, “A” for orange juice. The control system is programmed to translate each data set into real information according to preset formulas. 
     Once the reader  210  obtains package-specific information from the label  208   a  or  208   b , it sends the information to the control system. The control system is then able to display such information for the user, to regulate the mixing and dispensing of the product, to track the amount of remaining concentrate, and to monitor freshness of the concentrate to ensure safe consumption. 
     Referring now to  FIG. 19 , operational steps related to the data input system are illustrated. In step  226 , a concentrate holder with an empty or expired concentrate package is removed from the concentrate cabinet. In step  228 , it is then determined which side of the dispenser was the holder removed from or otherwise emptied. An internal flag is set for the control regarding the empty/out status. This can be accomplished through a variety of ways. For example, the machine may have a sensor that monitors the position of the concentrate holder, or the machine can be manually taught which side the concentrate holder was removed from. In one embodiment, a magnet is embedded in the concentrate holder (e.g., at the bottom) such that removal the holder triggers a reed switch at a corresponding position inside the dispenser to signal the removal to the control system. 
     Still referring to  FIG. 19 , once the control learns that a concentrate holder has been removed from the dispenser, in step  230 , it actuates the label reader, e.g., an optical scanner, and in step  232 , turns on indicators for the affected side, e.g., a red and amber LED. In step  234 , an operator refills the holder with a new concentrate package and places the holder back into dispenser. In step  236 , the operator manually presents a new label on the new drainage tube for the activated scanner and scans the barcode. Alternatively, the label is automatically detected and read by a sensor or reader in the dispenser. In step  238 , the control determines if the scan is successful. If not, it will direct the operator to rescan the barcode in step  240 . If the scan is successful, however, the scanner will power off and a unique product identifier is generated by the control in step  242 . This unique identifier, specific for each concentrate package, is kept in a registry on the control as a permanent record to prevent product tempering. 
     Because the control system regulates the pump speed and the pump delivers a set amount of concentrate through each revolution, the control system can monitor the amount of concentrate dispensed from a particular package at any given time and assign the information to the unique identifier. Accordingly, the control system can compute and display the theoretical volume left in a given package or to alert the operator when the concentrate is running low. Once the package is emptied out, the control will flag the associated identifier with a null status and not allow the package to be reinstalled. The unique product identifier will also be used by the control system to track how many times the package associated with it has been installed, and to continually monitor concentrate usage throughout the life of the package. If a package is removed from the dispenser prior to being completely used, the control will recognize the same package when it is reinstalled in the dispenser and will begin counting down the volume from the last recorded level. 
     Referring again to  FIG. 19 , the unique identifier is used to monitor and regulate other aspects of concentrate usage. For example, in step  244 , the control determines if the concentrate has expired or passed the best-used-by date. In step  246 , if the answer is affirmative, the control will flag that product identifier and disallow any further dispensing from the current package. In the next step  248 , a warning signal is indicated, e.g., through two red LEDs. The control also reactivates the scanner and the sequence reverts to step  234  to start replacing the package. If it is determined that the concentrate has not expired in step  244 , however, the control continues to determine if the barcode is still valid in step  250 . If the answer is negative, step  248  and subsequent steps are initiated. If the answer is affirmative, step  252  is initiated where information on desired compositional ratio setting and previously obtained from scanning the package label is processed. In step  254 , the control further determines, also from scanned information on the label, whether ice is normally required in the postmix product. 
     Based on information gathered in steps  252  and  254 , the control computes the volume of the concentrate needed for each portion size requested by the operator. In step  256 , default fill volumes are used for all portion sizes when it is indicated that no ice is needed for the postmix product. Otherwise, as in step  258 , fill volumes are offset by a predetermined value if need for ice is indicated. In either case, the control proceeds to step  260  to update the dispenser display with the appropriate flavor identity, also obtained from the scanning of the label in step  236 . 
     According to one feature of the invention, the control system is programmed and configured to regulate the mixing and dispensing process to achieve consistency in compositional ratio, e.g., between about 10:1 to about 2:1 for the ratio between the diluent and the concentrate. The control system needs two pieces of information to accomplish this task: desired compositional ratio and the flow rate of the diluent. The former can be obtained, as described above, through the data input system where a label provides the information to the control. The latter is received as an output signal generated by a metering device, e.g., a flowmeter, that is in electrical communication with the control circuit. In addition to set the rate of concentrate delivery, the control system, further based on portion size information, i.e., the specific portion size requested and whether ice is needed in the postmix product—this last information preferably also comes from a package label—decides on the duration of a dispensing cycle. 
     In an embodiment where a positive displacement pump, e.g., a nutating pump, is used to pump the concentrate into contact with the diluent to form a mixture, the motor is configured to actuate the nutating pump, and the amount of concentrate transferred by each motor revolution is fixed. Accordingly, encoder can be configured to regulate a rotary speed of the motor, and hence, the rate of concentrate transfer. The control system, in electrical communication with the encoder, sends a command to the encoder once it has computed a desired rotary speed and/or duration for a given dispensing cycle. Accordingly, the right amount/volume of the concentrate is added to each dispensing cycle. 
     For example, the control receives, from the package label, the desired compositional ratio between the water and the concentrate as 10:1. Further, the flowmeter signals the control that water is flowing at a rate of about 4 ounces (about 0.12 L) per second. That means the concentrate needs to be pumped at a rate of about 0.4 ounce (about 0.012 L) per second. Since each revolution of the pump piston always delivers 1/32 ounce (about 0.0009 L) of the concentrate, the control sets the piston to run at 12.8 revolutions per second. If a portion size of 21 ounces (about 0.62 L) is requested for a dispensing cycle and no ice is needed in the product according to the package label, the control will determine that the dispensing cycle should last for about 4.8 seconds. 
     Further, the control system can adjust the pump&#39;s motor speed. The encoder sends a feedback signal in relation to a current rotary speed to the control, and the control, in turn, sends back an adjustment signal based on the desired compositional ratio, and the water flow rate detected by the flowmeter. This is needed when water flow rate fluctuates, e.g., when a water supply is shared by multiple pieces of equipment. This is also necessary when the desired compositional ratio in the postmix product needs to be adjusted as opposed to have a fixed value. A preferred embodiment of the control system automatically adjusts the pump speed to ensure the desired compositional ratio is always provided in the postmix product. 
     Each of the patent documents and publications disclosed hereinabove is incorporated by reference herein for all purposes. 
     While the invention has been described with certain embodiments so that aspects thereof may be more fully understood and appreciated, it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the scope of the invention as defined by the appended claims.