Abstract:
The present invention recognizes the need for an apparatus and method for creating carbonated beverages having a customizable carbonation level. The invention uses a CPU to control an inlet valve which connects a tank of pressurized carbon dioxide to a vessel containing the beverage to be carbonized. The tube connecting the tank of pressurized carbon dioxide to the vessel contains an orifice for reducing the carbon dioxide&#39;s flow rate, thereby increasing control over the amount of carbon dioxide introduced to the vessel. A motor agitates the vessel, causing the carbon dioxide to become absorbed in the beverage. Then, an outlet valve causes excess pressure to drain from the vessel. An outlet orifice causes the pressure to release gradually, thus preventing the beverage from foaming.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a method and apparatus for carbonation of a liquid, more particularly, to a method and apparatus for creating a carbonated batch of a finished beverage product. 
       BACKGROUND OF THE INVENTION 
       [0002]    Carbonated water is generally formed by introducing a pressurized liquid and pressurized carbon dioxide gas into a carbonator tank. The pressure of the contents of the tank forces the carbon dioxide into the liquid, thus forming a carbonated liquid. Typically such carbonator tanks are bulky, large, and increase the manufacturing cost of a beverage dispensing system. 
         [0003]    Current carbonated beverages may be formed by using a carbonator to carbonate a liquid source and then introducing a flavored syrup concentrate to make a carbonated beverage. Additionally, prior art devices may include a small carbon dioxide cartridge that introduces carbonation under pressure into a tank of water and then add the syrup or other ingredients to create a finished beverage. 
         [0004]    However, prior art carbonation apparatuses are limited in the amount of carbonation that they introduce to the beverage because they do not agitate the beverage or have the ability to vary the pressure to create various carbonation levels, for example, low, medium and high levels of carbonation. Additionally, typical prior art apparatuses may be utilized to only carbonate a water source and do not carbonate a finished beverage. 
         [0005]    There is therefore a need in the art for a method and apparatus that provides reliable levels of carbonation to a beverage on an individual small batch basis such that the carbonation level may be adjusted to various levels. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a batch carbonation process in which a user introduces a liquid into a vessel, locks the vessel to an agitation mechanism, and selects a level of carbonation. Based on the level of carbonation selected by the user, a CPU operates to open a valve to introduce pressurized carbon dioxide into the vessel. The agitation mechanism operates to place a force on the liquid within the vessel, thus increasing the surface area of the contact between the liquid (which may be partially atomized) and the carbon dioxide gas within the vessel. Furthermore, the invention reduces the rate of flow of the pressurized carbon dioxide gas into the vessel by utilizing an orifice. Using a transducer, the invention measures the pressure of the carbon dioxide gas, and communicates the pressure measurement to the CPU, which adjusts the pressure within the vessel by opening and closing the inlet valve in accordance with the level of carbonation selected by the user until the selected level of carbonation is achieved. The CPU then stops the agitation mechanism upon completion of the carbonation cycle. Additional features of the invention include venting the pressure within the vessel after the desired level of carbonation has been obtained and controlling the rate of flow of the gas exiting the vessel by utilizing an orifice. 
         [0007]    A further feature of the invention is controlling the opening and closing of an outlet valve by the CPU upon completion of the carbonation process. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic of the carbonation process. 
           [0009]      FIG. 2  is a cross-section of the pressure mixing vessel. 
           [0010]      FIG. 3  is a perspective view of the types of orifices used as part of the invention. 
           [0011]      FIG. 4  is an exemplary chart of the carbonation cycles. 
           [0012]      FIG. 5  is an example of a low carbonation drink cycle. 
           [0013]      FIG. 6  is an example of a middle carbonation drink cycle. 
           [0014]      FIG. 7  is a detailed flow chart of the steps in the batch carbonation process. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]    Carbonation is the process of dissolving carbon dioxide into a solution of water under pressure. It is commonly used in the creation of soft drinks, tonic water and other carbonated drinks. Effervescence is the escape of gas from an aqueous solution. In many consumer products, such as soft drinks, for example, Coca-Cola, 7-Up and Pepsi, carbonation (more particularly, the effervescence of the escaping gas) enhances the flavor of the beverage. Carbonated beverages contain dissolved carbon dioxide. The process of dissolving carbon dioxide (CO 2 ) in water is called carbonation. Carbonation may occur naturally from fermentation or a mineral source. However, most carbonated soft drinks are carbonated utilizing carbon dioxide which is artificially added to the beverage. Artificial carbonation is typically performed by dissolving carbon dioxide under pressure into a liquid. 
         [0016]    This invention can be used for carbonation of a liquid inside a vessel. The liquid is not carbonated when it is placed in the vessel. Carbonation occurs through a process in which carbon dioxide is introduced into the vessel containing a liquid. The amount of carbon dioxide absorbed by the liquid is controlled by the rate with which the carbon dioxide is introduced in the vessel. The user thus has the option to create beverages having varying levels of carbonation to satisfy the palate of the consumer. This invention can be used with various liquids, such as juices, water, cola drinks, or other beverages. The present invention focuses on customizing the level of carbonation in a liquid to satisfy a customer&#39;s taste. 
         [0017]    Referring to  FIG. 1 , there is shown the apparatus  10  used for preparing the batch carbonation of various liquids. The process is controlled by a Central Processing Unit (“CPU”)  20  that controls an inlet valve  50  and an outlet valve  70 . The CPU  20  receives input data from a transducer  60  which monitors the pressure in the inlet flow line  54 . The CPU  20  is preprogrammed to recognize the various pressure readings obtained from the transducer  60  and acts accordingly to open and/or close the inlet valve  50 , which may be a solenoid type valve or other valve, to control the level of carbon dioxide gas introduced into the vessel  40 . The CPU  20  further operates to activate the agitation mechanism  80  upon starting the system. Additionally, the CPU  20  operates to open the outlet valve  70  upon completion of the carbonation process. 
         [0018]    As seen in  FIG. 2 , the invention utilizes a vessel  40  into which an operator may introduce a liquid  46 . It is preferable that the vessel  40  be made of stainless steel. However, it could be made of other material provided that the material is sufficient to withstand pressure as high as 100 pounds per square inch (“PSI”) during the carbonation process. The user may enter a desired volume of liquid  46  into the vessel  40 , provided that there is at least some empty space in the vessel  40  which allows mixing of the liquid with the carbon dioxide. The optimal ratio between empty space (i.e. air) and liquid  46  within the vessel  40  is two-thirds volume of liquid and one-third volume of empty space. However, this ratio can be varied from as low as 5% air space above the liquid to as high as 95% air space above the liquid volume. Regardless of the ratio of liquid  46  to empty space in the vessel  40 , the liquid  46  in the vessel  40  will carbonate to some level. A higher ratio of empty air space to liquid volume results in a greater rate of carbonation of the liquid  46 . The inverse is true for a lower ratio of air to liquid  46  in the vessel  40 . Moreover, it is preferable to introduce liquid  46  at a temperature below 40° F. to help effectuate the carbonation process or, alternatively introduce ice into the vessel  40  along with the liquid  46  to reduce the temperature of the liquid. 
         [0019]    The vessel  40  may also contain a seal  48 . The user may select a level of carbonation on the user input interface (not shown) which communicates the selected level to the CPU  20 . The same may be done with the volume of liquid the user placed in the vessel  40 . 
         [0020]    Within the housing (not shown) of the batch carbonation mechanism, there is a chamber to receive the vessel  40 . The chamber includes a locking mechanism  49  which seals and locks the vessel  40  into place within the housing. The housing contains an agitation mechanism  80 . The agitation mechanism  80  comprises a motor  82  which turns a shaft  83 . The shaft  83  operates to rotate a cam  84  having a linkage  85 . Rotation of the cam  84  operates to move linkage  85  up and down. The linkage  85  is connected to a platform  86  to which the locking mechanism  49  is fixed. The platform  86  moves up and down along a guide rail  87  in response to rotation of the motor  82 . In this configuration, the platform  86  moves up and down along the guide rail  87 . Since the platform  86  holds the vessel  40 , the vessel  40  also moves up and down along the guide rail  87 . The vessel  40  moves in a reciprocal manner to a maximum upward position and a minimum downward position along the guide rail  87 . While the preferred embodiment demonstrates the movement of the vessel  40  in an upper and lower maximum position, other agitation configurations may be utilized such as, by way of example, rotation, oscillation and/or horizontal reciprocal movement. 
         [0021]    One aspect of the invention recognizes that a significant jolting force should be placed upon the liquid  46  contained in the vessel  40  when the vessel  40  reaches its maximum upward and minimum downward positions. The strong force created by the sudden change in direction of the movement of the vessel  40 , for example, from an upward movement to a downward movement at the maximum upward position of the vessel  40 , causes a jolting force to be applied to the liquid  46  within the vessel  40 . The effect of the jolting force acting upon the liquid  46  is that a portion of the liquid  46  within the vessel  40  will atomize. During atomization, the liquid  46  is suspended within the carbon dioxide gas to increase the surface area of the contact between the carbon dioxide gas and the suspended liquid. The greater surface area between the carbon dioxide and the liquid  46  causes a greater carbonation level. This is because the atomized liquid has a different pressure than the carbon dioxide, which causes the carbon dioxide to be absorbed into the liquid  46 , thus forming a carbonated liquid having a specified volume of carbonation. In order to sufficiently atomize the liquid  46  within the vessel  40 , a force of 3 gravitational units (g) or greater should be placed upon the liquid  46  within the vessel  40 . It has been found that the optimal force to atomize the liquid  46  is approximately 6 G force units applied at the two extremes of the movement of agitation mechanism  80 . 
         [0022]    The locking mechanism  49  of the vessel  40  includes an inlet flow line  54  and outlet flow line  72 . The inlet flow line  54  introduces carbon dioxide into the vessel  40 . The outlet flow line  72  permits excess pressure or carbon dioxide to exit the vessel  40  upon completion of the carbonation process. The inlet flow line  54  is connected to a high pressure carbon dioxide supply  30 . The high pressure carbon dioxide supply  30  has a regulator  32  which reduces the pressure of the carbon dioxide exiting the regulator  32  to approximately 100 PSI. The high pressure carbon dioxide supply  30  and regulator  32  are controlled by an inlet valve  50  which may open and close. The inlet valve  50  is opened and closed based upon input from the CPU  20 . The CPU  20  receives input from the transducer  60  which supplies a reading of the pressure within the inlet flow line  54 . The pressure in the inlet flow line  54  is the same as the pressure within the vessel  40 . The CPU  20  is programmed to read the pressure within the inlet flow line  54  and determines the amount of carbon dioxide that needs to be introduced into the vessel  40 . The CPU  20  will open inlet valve  50  until a predetermined pressure is achieved in the vessel  40 . The pressure is measured by the transducer  60 . As the inlet valve  50  opens, the pressure within the vessel  40  increases to the predetermined pressure stored in the CPU  20 . The apparatus functions as a closed loop control, wherein the transducer  60  provides feedback to the CPU  20  regarding the current pressure level within the inlet flow line  54 , which is approximately the same pressure as in the vessel  40 . The vessel  40  is brought to a predetermined pressure setting based on a desired carbonation level. The closed loop then maintains the predetermined pressure within the vessel  40  as the liquid  46  within the vessel  40  is being agitated by the agitation mechanism  80 . 
         [0023]    As the liquid  46  within the vessel  40  is agitated, the liquid  46  becomes atomized, or partially reduced to droplet form, and absorbs the carbon dioxide into the liquid  46 . The pressure within the vessel  40  drops as the carbon dioxide is absorbed into the liquid  46 . The CPU  20  detects when the pressure in the vessel has dropped below a certain level and opens inlet valve  50  to reintroduce carbon dioxide into the vessel  40 . In this way, the CPU  20  can maintain a constant pressure within the vessel  40 . This process is continued until the liquid  46  becomes saturated with carbon dioxide. 
         [0024]    A problem faced in the development of the present invention is the fact that pressurized carbon dioxide moves through the tubing and into the vessel  40  so quickly that the regulator  32 , inlet valve  50 , and CPU  20  cannot provide meaningful regulation of the flow of carbon dioxide. In other words, the carbon dioxide flows so fast that the vessel  40  receives a high amount of carbon dioxide even when the regulator  32 , inlet valve  50 , and CPU  20  are configured to introduce only a low amount of carbon dioxide. An example of this problem is shown in  FIG. 3 , which shows pressure as measured by the transducer  60  during operation of the agitation mechanism  80  after the inlet valve  50  has been opened to introduce pressurized carbon dioxide gas into the vessel  40 . The chart of  FIG. 4  shows the pressure in the vessel  40  as a function of time, in an exemplary scenario in which the agitation mechanism  80  is activated, and pressurized carbon dioxide is being introduced through inlet valve  50 . As can been seen, the slope of the rate of increase of carbon dioxide into the vessel  40  is extremely high, which means, in essence, that the carbon dioxide is absorbed into the liquid  46  at a faster rate than the CPU  20  can react to close inlet valve  50 . The graph depicts the increase in pressure within the vessel from 0 PSI to 90 PSI within approximately ⅕ of a second. This rapid increase in pressure cannot be conveyed to the CPU  20  by the transducer  60  in such a short amount of time. Nor can the CPU  20  signal to close the inlet valve  50  in such a small time increment. What occurs is that the carbon dioxide is rapidly absorbed into the liquid as depicted in  FIG. 4 . The CPU  20  cannot signal the valve  50  to close until after the liquid  46  has already become fully saturated with carbon dioxide. In essence, the liquid  46  reaches a saturation point of carbon dioxide very rapidly, i.e. within fractions of a second. The device cannot be operated to carbonate the liquid  46  to lower saturation levels other than maximum saturation. The present invention solves this problem by slowing down the flow rate of carbon dioxide, thereby allowing the regulator  32 , inlet valve  50 , and CPU  20  sufficient time to control the carbon dioxide. 
         [0025]    To solve the problem, an inlet orifice  52  may be positioned within the inlet flow line  54  or inlet valve  50  to reduce the slow rate of the carbon dioxide gas. The inlet orifice  52  reduces the flow rate of the high pressure carbon dioxide supply  30  into the vessel  40 . The optimal range for the flow coefficient (C v ) is between 0.004 and 0.022. Other flow rates could be used depending on carbonation levels desired and how fast the CPU  40  could react to rapid changes in carbon dioxide pressure changes. 
         [0026]    The inlet orifice  52  slows down the rate of flow of the carbon dioxide gas entering the vessel  40 . An example of the inlet orifice  52  can be seen in  FIG. 3 . Any size orifice can be used, however, it is preferred that the orifice be between 0.03 inches to 0.05 inches and positioned within a ⅜ inch diameter tubing. Referring back to  FIG. 1 , the inlet orifice  52  may be positioned anywhere along the inlet flow line  54  between the regulator  32  and the transducer  60 . It may also be incorporated into inlet valve  50 . The inlet orifice  52  creates a pressure drop within the inlet flow line  54  which slows the flow rate of the carbon dioxide gas through the inlet flow line  54 . The reduction in the flow rate of the carbon dioxide gas into the vessel  40  permits the transducer  60  sufficient time to send the appropriate signal to the CPU  20  such that the CPU  20  has sufficient time to close inlet valve  50  prior to the liquid  46  becoming completely saturated with the carbon dioxide. The process of varying the rate of introduction of carbon dioxide into the vessel  40  allows for the ability to control the level of carbonation of the liquid  46  in the vessel  40 . By slowing the rate in which carbon dioxide flows through inlet flow line  54  provides enough time for the CPU  20  to read the different pressure measurements from the transducer  60  and react to the readings by either opening or closing inlet valve  50 . This allows for the formation of beverages that have differing carbonation levels. 
         [0027]    The effect of a lower flow rate on the level of carbonation can be seen in  FIG. 5 .  FIG. 5  depicts a graph of the pressure measurements versus time the inlet valve  50  is opened and after carbon dioxide has been introduced into the vessel  40  and the agitation mechanism  80  has started operating at a mid-level carbonation. The inlet orifice  52  allows for a slower rate of introduction of the carbon dioxide gas into the vessel  40 . As can be seen in  FIG. 5 , when using the inlet orifice  52 , it takes two seconds for the pressure in the vessel  40  to reach 75 PSI. This is much slower than the fractions of a second it took for the pressure within the vessel  40  to reach 90 PSI without the inlet orifice  52  as shown in  FIG. 4 . The CPU  20 , as can be seen in  FIGS. 1 and 5 , receives a signal from the transducer  60  that a pressure of 75 PSI has been reached within the vessel  40 . The CPU  20  is programmed to close the inlet valve  50  upon receiving a signal that the transducer  60  has obtained a reading of 75 PSI. This permits the carbon dioxide gas to be absorbed into the liquid  46  as it is agitated within the vessel  40 . As the carbon dioxide is absorbed into the liquid  46 , the pressure within the vessel  40  drops. When the pressure within the vessel  40  reaches a pre-determined value, such as 60 PSI in  FIG. 5 , the transducer  60  sends a signal to the CPU  20  that a pressure measurement of 60 PSI has been obtained. The CPU  20  then operates to open inlet valve  50  to allow pressurized carbon dioxide to enter the vessel  40 . As with the initial process, once a pressure of 75 PSI is read by transducer  60  and sent to CPU  20 , the inlet valve  50  is closed. Once again, as the liquid  46  within the vessel  40  is agitated, the carbon dioxide is absorbed within the liquid  46  and the pressure within the vessel  40  drops. This process continues until a stabilized condition is reached wherein the liquid  46  has reached a mid-range of carbonation. At this time, the CPU  20  activates outlet valve  70  to release excess pressure. 
         [0028]    An example of the pressure measurements for a low level carbonated drink is depicted in  FIG. 6 . The inlet orifice  52  allows for a slower rate of introduction of the carbon dioxide gas into the vessel  40 . As can be seen, it takes four seconds to reach a pressure of 35 PSI in the vessel  40 . This is much slower than the fractions of a second it took for the pressure within the vessel  40  to reach 90 PSI without the inlet orifice  52  as shown in  FIG. 4 . The CPU  20 , as can be seen in  FIGS. 1 and 6 , receives a signal from the transducer  60  that a pressure of 35 PSI has been reached within the vessel  40 . The CPU  20  is programmed to close the inlet valve  50  upon receiving a signal that the transducer  60  has obtained a reading of 35 PSI. This permits the carbon dioxide gas to be absorbed into the liquid  46  as the liquid  46  is agitated within the vessel  40 . As the carbon dioxide is absorbed into the liquid  46 , the pressure within the vessel  40  drops. When the pressure within the vessel  40  reaches a pre-determined value, such as 10 PSI in  FIG. 6 , the transducer  60  sends a signal to the CPU  20  that a pressure measurement of 10 PSI has been obtained. The CPU  20  then operates to open inlet valve  50  to allow pressurized carbon dioxide to enter the vessel  40 . As with the initial process, once a pressure of 35 PSI is read by transducer  60  and sent to CPU  20 , the inlet valve  50  is closed. Once again, as the liquid  46  within the vessel  40  is agitated, the carbon dioxide is absorbed within the liquid  46  and the pressure within the vessel  40  drops. This process continues until a stabilized condition is reached wherein the liquid  46  has reached a low-range of carbonation. The inlet orifice  52  reduces the flow rate of carbon dioxide into the vessel  40  such that an actual measurement of the pressure can be read. 
         [0029]    The step of introducing carbon dioxide into the vessel  40  may include actuating the inlet valve  50  having a differing pressure, closing an outlet valve  70 , wherein actuation of the pressure valve toggles a display on the housing indicating pressure is being introduced into the pressure vessel  18 . 
         [0030]    The CPU  20  also controls whether the outlet valve  70  is open or closed. The outlet valve  70  is opened after a carbonation cycle has been completed. Once the carbonation cycle is completed, the high pressure carbon dioxide supply  30  is shut off by closing inlet valve  50  by the CPU  20 . The carbon dioxide gas is then vented through outlet flow line  72  through an open pressure vent  74 . The outlet valve  70  is open when the carbonation cycle is complete to release pressure within the vessel  40 . One problem faced by opening the outlet valve  70  was that the carbonated liquid  46  would foam upon the immediate release of pressure within the vessel  40 . Utilizing an outlet orifice  76  along outlet flow line  72  prevents a sharp pressure drop within the vessel  40  upon opening of the outlet valve  70 , thus preventing foaming and the loss of a majority of the carbon dioxide from the liquid  46 . Without outlet orifice  76 , the pressure would be released at a high rate, thereby decreasing the level of carbon dioxide contained within the liquid  46 . The outlet orifice  76  slows down the rate of flow of the gas exiting the vessel  40 . An example of the orifice  76  can be seen in  FIG. 3 . Any size orifice can be used, however, it is preferred that an orifice is between 0.03 of an inch to 0.05 of an inch within a ⅜ inch diameter tubing. Referring back to  FIG. 1 , the outlet flow line  72  may include an open pressure vent  74 . The outlet orifice  76  creates a pressure drop within the line which slows the flow rate of the gas through the line. 
         [0031]    As stated above, the liquid beverage may include a finished beverage product that includes water and additional flavoring ingredients such as coffee. The batch carbonation method of forming a carbonated beverage in a batch allows a user to select a desired carbonation level and produce a carbonated beverage from a finished beverage that includes both water and flavoring ingredients. Various liquid beverages may be introduced and are limited only by the beverage having a high enough percentage of water and low enough viscosity to allow a carbonation process to occur. 
         [0032]    A short description for the process of carbonating a liquid in the batch carbonation mechanism may prove helpful. Referring to  FIG. 7 , a user selects the level of carbonation he or she desires for the completed beverage product. The user inputs the selected carbonation level which is sent to the CPU  20 . The user inputs liquid  46  to be carbonated into the vessel  40 . The user then seals the vessel  40  and latches the vessel  40  to the platform  86  of the agitation mechanism  80 . Once the vessel  40  is latched in place, the CPU  20  activates the agitation mechanism  80  to begin movement of the vessel  40  at which time the liquid  46  begins to atomize within the vessel  40 . Upon operation of the device, the CPU  20  opens inlet valve  50  such that carbon dioxide gas from the high pressure carbon dioxide supply  30  proceeds through regulator  32 , through inlet flow line  54  and through transducer  60  into the vessel  40 . An inlet orifice  52  is positioned in the inlet flow line  54  to slow the flow rate of the carbon dioxide gas by a coefficient of 0.004 to 0.022. The transducer  60  measures the pressure of the carbon dioxide gas in the inlet flow line  54  which approximates the pressure within vessel  40 . The CPU  20  works in conjunction with the transducer  60  and inlet valve  50  to create a closed loop system wherein the transducer  60  communicates with the CPU  20  to provide the pressure measurement in the inlet flow line  54 . Based on the selected level of carbonation, the CPU  20  continues to hold inlet valve  50  open until the transducer  60  registers the predetermined pressure for the selected carbonation level. Once the transducer  60  registers the predetermined pressure level for a selected carbonation level, the CPU  20  sends a signal to close inlet valve  50 . Because the liquid  46  within the vessel  40  is being agitated, the carbon dioxide gas is absorbed within the liquid  46 . As the carbonated gas is absorbed within the liquid, the pressure drops within the vessel  40 . When the pressure reaches a certain lower limit, the transducer  60  registers the measurement with the CPU  20  which in turn opens the inlet valve  50  to raise the pressure within the vessel  40  until the predetermined pressure is obtained for the selected carbonation level. This procedure continues until the liquid  46  within the vessel  40  stabilizes at the desired carbonation level. At that time, the CPU  20  operates to close inlet valve  50  and ceases operation of the agitation mechanism  80 . The outlet valve  70  is open such that the pressure within the vessel reaches ambient pressure. There is an outlet orifice  76  within the outlet flow line  72  which reduces the flow rate of the gas from the vessel  40  thus preventing the liquid  46  from foaming into the outlet flow line  72 . 
         [0033]    While embodiments of the invention have been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.