Abstract:
The invention presents a cold beverage dispenser which uses a heat exchanger to cool incoming water with a very cold closed loop of chilled coolant. Under control of a control system, the cooled water from the heat exchanger is mixed with uncooled in put water to regulate its temperature, then (if desired) carbonated. The regulated temperature water, optionally carbonated, is mixed with a liquid concentrate and dispensed at one or more dispensing stations. Preferably, the temperature, carbonation and strength of the dispensed beverage is controllable by the consumer.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims an invention which was disclosed in Provisional Application No. 60/642,311, filed on Jan. 7, 2005, entitled “Beverage Dispenser with Disposable Pump”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference. 
     This application is a continuation-in-part of co-pending application Ser. No. 11/155,058 entitled “Beverage Dispenser”, filed on Jun. 17, 2005, which application is incorporated herein by reference. The &#39;058 application claimed the benefit of the provisional application listed above, and also Ser. Nos. 60/586,105, filed Jul. 7, 2004, entitled “Hot Beverage Dispenser” and 60/682,107, filed May 18, 2005, entitled “Plastic Pump for Beverage and Soap Dispensing” 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to the field of beverage dispensers. More particularly, the invention pertains to dispensers for cold beverages. 
     2. Description of Related Art 
     In the current commercial cold beverage dispensers, the incoming water is flowing through a high power chiller which has to cool down the water in a one pass flow-through manner. When the dispenser is not used a significant amount of water is left in the idle chiller and in the tubing from the chiller to the output valves on each of the dispensing spigots. At periods of the day when there are relatively small number of users the trapped water will warm up and when the next person is dispensing his beverage the first amount of water dispensed will be the trapped warmer water. In commercial cold beverage dispensers the amount of the trapped water is significant. On the other hand during the periods of the day when there are relatively large number of users the chiller is not able to cool the water to the desired temperature. Therefore the dispensed beverage temperature can vary significantly from one customer to the other. 
     SUMMARY OF THE INVENTION 
     The invention presents a cold beverage dispenser which uses a heat exchanger to cool incoming water with a very cold closed loop of chilled coolant. Under control of a control system, the cooled water from the heat exchanger is mixed with uncooled input water to regulate its temperature, then (if desired) carbonated. The regulated temperature water, optionally carbonated, is mixed with a liquid concentrate and dispensed at one or more dispensing stations. Preferably, the temperature, carbonation and strength of the dispensed beverage is controllable by the consumer. 
     The design of the cold beverage dispenser of the invention allows each customer to select the dispensed beverage temperature according to his preference with accuracy of 1° F. In addition our innovative dispenser will allow each customer to design his own beverage according to his preference to enhance his satisfaction. The customer will be able to determine the sweetness (strength) of the dispensed beverage and the amount of carbonation according to his desire. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a schematic drawing of the cold beverage dispenser of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     One of the innovations of our cold beverage dispenser is that it will allow each customer to design his beverage according to his preference. Using a sophisticated, menu driven touch screen technology the customer can modify three parameters of his beverage via the soft keys on the touch screen of the controller. The customer can select the temperature, strength, and carbonation of his beverage according to his preference which will increase his enjoinment from the cold beverage. 
     A schematic drawing of the multi-spigot cold beverage dispenser can be seen in  FIG. 1 . The dispenser can be divided into the following subsystems: 
     A. Closed loop cooling system 
     B. Input water system 
     C. Liquid Concentrate dispensing system 
     D. Micro-computer based digital controller and user interface 
     In our cooling system, as opposed to the current cold beverage dispensers, we can use much smaller chiller since:
         A. The very cold coolant is circulating continuously through the chiller  6  and the Heat Exchanger  7  at a rate of a few gallons per minute which improves the cooling efficiency of the chiller  6  and the cooling efficiency of the Heat Exchanger  7 ; and   B. We are using a very cold coolant reservoir tank  8  of a few gallons.       

     The closed loop water cooling system includes a water chiller  6 , a coolant liquid insulating tank  8 , the coolant circulating pump  9 , and a high efficiency heat exchanger  7 . The chiller  6 , the coolant holding tank  8 , and the coolant circulating pump  9  can be located outside the main dispenser and only the heat exchanger  7  in located inside the dispenser. This will minimize the dispenser size, simplify the dispenser design, and lower the cost of manufacturing. For a mid size commercial cold beverage dispenser the coolant tank  8  typically will hold about 5 gallons of coolant liquid. The coolant liquid can be water or any other kind of coolant liquid used in cooling systems. Because we have at our disposal a very cold coolant reservoir we can dispense the beverage at a high rate (preferably 2-3 ounces per second). In addition, the very efficient heat exchanger  7  is small in size and can be mounted very close to the spigots therefore the volume of the trapped water in the tubing is very small. 
     The closed loop cooling system works as follows: 
     The circulating pump  9  circulates the coolant liquid continuously through the heat exchanger  7 , the chiller  6 , and the holding tank  8 , typically at a rate of few gallons per minute. The coolant liquid temperature is regulated by a temperature control system (not shown) which also controls the chiller on/off time. 
     The incoming fresh water is connected to the dispenser through a water filter  1  to improve the quality and test of the dispensed cold beverage. The incoming water flow is controlled by the input valve  2  and its pressure, in the dispenser, is controlled by the pressure regulator or flow restrictor  3 . The incoming filtered water is split to two arms at junction  18 . One arm is connected to the input of one half of the heat exchanger  7  while the second arm is connected to the input of valve  11 . 
     The part of the filtered, fresh water that is flowing through the heat exchanger  7  is cooled down to within few degrees of the coolant temperature by the very cold coolant, which is circulating at high flow rate in the second half of the heat exchanger  7 . The flow rate of the fresh, very cold, filtered water from the heat exchanger  7  is controlled by valve  10 . The outputs of the control valves  10  and  11  are connected together at junction  19 . The output of junction  19  is connected in parallel to all the beverage dispensing stations ( 25   a - 25   d ). 
     To enhance the customer satisfaction, our advanced cold beverage dispenser will allow each customer to select the temperature of the dispensed beverage. The temperature of the dispensed beverage is measured by the temperature sensor  14  located at the output of junction  19 . Controller  30  will adjust the duty cycles of the cold valve  10  and warmer valve  11  differentially to control the temperature of the water at junction  19  anywhere between the temperature of the cold water from the heat exchanger  7  and the temperature of the incoming water  1 . Thus, if cold valve  10  is open all the time (i.e. 100% duty cycle), and input temperature valve  11  is closed (0% duty cycle), the temperature at  19  will be the same as the cold water. Conversely, if cold valve  10  is at 0% duty cycle, and input temperature valve  11  is at 100%, the temperature is the same as the input water. At 50% duty cycle on each valve, the temperature is halfway between. 
     The dispensed beverage temperature control method is the same as described in the parent patent application Ser. No. 11/155,058 entitled “Beverage Dispenser” filed on Jun. 17, 2005, which application is incorporated herein by reference. 
     In addition, our advanced cold beverage dispenser will preferably allow each customer to select whether or not they would like to add carbonation and the amount of carbonation they would like to add. 
     The carbonation system includes the carbon-dioxide tank  12 , which can be located outside the dispenser, regulator valve or flow restrictor  13  and a gas flow meter  22 . The carbon-dioxide is injected into the cold water at junction  20 . A digital feedback control system regulates the amount of carbonation according to the customer selection via a user input interface, such as touch screen  5 . The carbonation control system operates as follows: 
     The control system uses the water flow rate, as measured by the water flow meter  4 , as one input and the customer carbonation selection from the touch screen  5  as a second input. Using these two inputs the controller code calculates the required CO 2  flow rate. The CO 2  flow rate, which is measured by the gas flow meter  22 , is compared to the calculated rare and the controller modulates the on/off duty cycle time of valve  13  in such a way that the amount of CO 2  dispensed with the cold beverage is according to the customer selection. 
     The method of controlling the carbonation by controlled mixing of the CO 2  and water by varying the duty cycle of valve  13  is analogous to the control of temperature by regulating the duty cycle of valves  10  and  11 . The higher the duty cycle of valve  13  (i.e. the longer the valve is open relative to the time the valve is closed in a given cycle) the more CO 2  mixes with the water, and thus the resulting beverage is more carbonated. For noncarbonated beverages, valve  13  is left closed (0% duty cycle), for maximally carbonated beverages it is left open (100% duty cycle), and any other duty cycle is somewhere in between. 
     Flavored liquid beverage concentrates at each dispensing station  25   a - 25   d , which are preferably stored in airless collapsible bags  15 , will preferably be loaded into the dispenser from the front of the dispenser to allow easy and fast replacement of the empty bags. The liquid beverage concentrate is injected by pump  16  into the cold water at junction  21 , and valve  17  controls the flow of beverage into the user&#39;s cup at the dispensing station  25   a - 25   d.    
     In order to further enhance the customer satisfaction our dispenser will preferably allow each customer to select the “strength” of his cold beverage using the touch screen  5 . Each one of the strength options will determine a different mixing ratio between the cold water and the liquid beverage concentrate. 
     To control the mixing ratio between the cold water and the beverage concentrate the dispenser uses a digital feedback control loop, using the water flow rate, as measured by the water flow meter  4 , to accurately control the beverage concentrate dispensing device  16 . 
     The dispensing device  16  is preferably a pump with a controllable pump rate, whether by controlling the frequency of cycling of a piston-type pump, or the speed of rotation of a peristaltic pump, or some other approach. When the pump is at maximum output (i.e. fastest stroke rate or peristaltic rotation speed), the beverage is strongest. Reducing the pump output reduces the strength of the beverage proportionally. 
     The mixing ratio control method for different concentrate dispensing devices is described in detail in parent patent application Ser. No. 11/155,058 filed on Jun. 17, 2005, which is incorporated here by reference. 
     Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.