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. During the pressurization process, the pressure inside the vessel is monitored by the CPU to determine whether more CO2 should be added to the vessel. 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:
CLAIM TO PRIORITY 
     This present application claims the benefit of U.S. Provisional Application No. 61/831,511 filed on Jun. 5, 2013 and incorporates by reference the application in its entirety. The present application also incorporates by reference, in its entirety, U.S. application Ser. No. 13/908,847, entitled “Method And Apparatus For Carbonating A Liquid,” filed on Jun. 3, 2013, in the name of Nicholas Giardano. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method and apparatus for carbonation of a liquid, more particularly, to a method and apparatus for creating a carbonated batch product at a customized level of carbonation based upon the individual desire of the customer. 
     BACKGROUND OF THE INVENTION 
     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. 
     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. 
     Existing prior art teaches that carbonated beverages can be created by using a carbonator to carbonate water, and then mixing the carbonated water with a flavored syrup concentrate (such as concentrated cola components) to make a carbonated beverage. Also, machines are available that use a small CO2 cartridge to introduce carbonation into a mixed drink. But in the prior art devices, the amount of carbonation that can be introduced into a beverage is not variable, nor does the device operate to agitate the beverage after CO2 has been introduced. An additional limitation of the prior art devices is that they do not have the ability to control the foaming created when syrups or other products are mixed and carbonated. 
     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. 
     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 based upon the individual needs of a customer. 
     SUMMARY OF THE INVENTION 
     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 present 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. 
     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 
         FIG. 1  is a schematic of the carbonation process. 
         FIG. 2  is a cross-section of the pressure mixing vessel. 
         FIG. 3  is a chart comparing time (seconds) to pressure (PSI) in the embodiment of  FIG. 1 . 
         FIG. 4  is a schematic of an alternative embodiment of the carbonation process. 
         FIG. 5  is an example of an optimal carbonation chart. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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. 
     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. 
     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. 
     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. 
     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 . 
     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. 
     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 6G force units applied at the two extremes of the movement of agitation mechanism  80 . 
     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 . 
     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. 
     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 . More specifically, the chart of  FIG. 3  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  40  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  46  as depicted in  FIG. 3 . The CPU  20  cannot signal the inlet 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. 
     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  20  could react to rapid changes in carbon dioxide pressure changes. 
     In an alternative embodiment,  FIG. 4 , the present disclosure includes a device  110  for creating customized carbonated beverages. The device includes a pressurized carbon dioxide (CO2) tank  130  that supplies CO2 through an inlet tube  154  and into a mixing vessel  140 . The CO2 supply  130  includes a mechanical regulator  132  for controlling pressure. The regulator  132  provides the added safety feature of preventing over-pressurization of the device. 
     The CO2 tank  130  is connected to an inlet tube  154 , which is connected to a mixing vessel  140 . A transducer  160  may be positioned in the inlet tube  154  to measure the CO2 pressure in the mixing vessel  140 , since the inlet tube  154  may have a pressure roughly equal to the mixing vessel  140 . The transducer  160  may also be placed in the mixing vessel  140  itself. The inlet tube  154  further includes an inlet valve  150 , which controls the flow of CO2 through the inlet tube  154  and into the mixing vessel  140 . The mixing vessel  140  may also be attached to an outlet tube  172 , through which excess pressure may be relieved after the carbonation process is complete. An exemplary device configuration is described in applicant&#39;s co-pending U.S. patent application Ser. No. 13/908,847, which is hereby incorporated by reference in its entirety. 
     The device for creating customized carbonated beverages may also include a CPU  120  connected to a user interface  122 . The CPU  120  is connected to the transducer  160 , to the inlet valve  150 , and to an agitation mechanism  182 . As such, the CPU  120  may receive an input from a user—for example, specifying a beverage size or a carbonation level—and use pressure readings from the transducer  160  to control the inlet valve  150  accordingly. In one embodiment, the CPU  120  and the other components may be connected to a PCX board. 
     In one embodiment, the user interface may include a dial  124  that allows the user to set a pressure (the pressure selected will determine the level of carbonation of the beverage). The selected pressure is received by the CPU  120 , which then controls the inlet valve  150  to begin the flow of CO2 from the CO2 tank  130  to the mixing vessel  140 . The pressure of CO2, flowing through the inlet tube  154 , and into the mixing vessel  140  is measured by the transducer  160 , or by any other type of pressure sensor. The pressure is converted to a voltage signal, which is supplied back to the CPU  120 . In that way, the CPU  120  is able to continuously determine the current pressure level. 
     The CPU  120  continues allowing CO2 pressure to build until a predetermined pressure is reached. The CO2 pressure continues to build while the inlet valve  150  is in the open position, but the CPU  120  may also “pulse” the inlet valve  150  rather than maintaining it in a continuous open position. 
     The predetermined pressure level is supplied to the CPU  120  from the memory. More specifically, the memory stores a predetermined pressure level corresponding to each possible user selection on the user interface. In other words, if the user interface allows the user to select from a HIGH, MEDIUM, and LOW setting, then the memory contains one pressure level (measured in PSI for example) corresponding to each selection. 
     An agitation motor  182  is attached to a platform  185  that holds the mixing vessel  140 . The motor  182  is electronically connected to the CPU  120  so that the CPU  120  can activate and deactivate the agitation motor  182 . The agitation motor  182  causes the mixing vessel  140  to agitate the liquid and CO2 in the mixing vessel  140 . For example, the mixing vessel  140  may be agitated between a maximum upward position and a minimum downward position, where each stroke is a minimum of 0.75″, at a minimum rate of 280 RPM. The CPU  120  activates the agitation motor  182 , and thus begins the agitation cycle, either when the CPU  120  opens the inlet valve  150  to begin building pressure, or once the predetermined pressure is achieved. 
     As shown in  FIG. 5 , agitation of the mixing vessel  140  causes the beverage inside the mixing vessel  140  to mix with the CO2 introduced through the inlet valve  150  and increase the pressure  200 (A). As the CO2 is absorbed into the beverage, the pressure in the mixing vessel  140  drops  210 (B). The CPU  120  receives the pressure readings from the transducer  160  (or other pressure sensor). Depending on the desired carbonation level of the beverage, it may be desirable to introduce an additional dose of pressurized CO2 into the mixing vessel  140 . Thus, once the pressure drops below the predetermined level (because the agitation is causing the CO2 to absorb in the beverage), the CPU  120  may be programmed to again open the inlet valve  150  and bring the pressure level back to the original  220 (C), predetermined level of pressure. 
     The pressure in the mixing vessel  140  will continue to drop  230 (D) as the CO2 is absorbed into the beverage, whereupon more CO2 will be introduced into the mixing vessel  140  to again increase the pressure to a predetermined level  240 (E). The time between each maximum and minimum pressure increases as the beverage becomes saturated with CO2  250 (F).  FIG. 4  demonstrates the increase in time between the highs and lows of the pressure reading as the beverage becomes more saturated. For example, the time between  200 (A) to  210 (B) is less than  220 (C) to  230 (D), which is less than  240 (E) to  250 (F). Likewise, the time between  210 (B) to  230 (D) is less than the time between  230 (D) to  250 (F). 
     FIGS. 4, 5, and 6 of incorporated U.S. patent application Ser. No. 13/908,847 demonstrate a pressure reading where the CPU re-introduces pressure as the CO2 is absorbed. This cycle of reintroducing CO2 pressure may be continued for a predetermined time, or for a predetermined number of cycles. The amount of time, or number of cycles, is dictated by the desired carbonation level. 
     A lower level of carbonation may be achieved simply by introducing a predetermined first level of pressure and agitating the mixing vessel for a predetermined time. The time of agitation may be measured by the CPU  120  using a timer. 
     The CPU  120  may use a timer to measure the time between the pressure drops over the course of multiple cycles. For example, to create a highly carbonated beverage, the CPU  120  will control the inlet valve  150  to achieve a pressure of 90 PSI in the mixing vessel  140  when agitation begins. As the mixing vessel  140  is agitated, the pressure drops because CO2 is absorbed into the beverage. In this embodiment, the CPU  120  is programmed to allow the pressure to drop to approximately 60 PSI. When the transducer  160  determines that the pressure in the mixing vessel  140  has reached 60 PSI, the CPU  120  operates to open valve  150  to introduce CO2 gas into the mixing vessel  140  to raise the pressure within the mixing vessel  140  to 90 PSI. As agitation continues, the pressure again drops toward 60 PSI. This creates a “sawtooth” graph of pressure reading as shown in  FIG. 3 . The CPU  120  uses a timer to measure the time between the highs and/or lows of the pressure reading. In this embodiment, the time between the highs and lows is used to calculate the saturation level of the CO2 in the beverage. In theory, as the beverage becomes more saturated with carbonation, the rate at which it continues to absorb CO2 decreases. Therefore, as the beverage becomes more carbonated, the time between the highs and lows of the cycle increases. The CPU  120  uses the timer to measure the cycles, and ends the carbonation cycle once a desired saturation level is achieved. To implement this embodiment, one needs a CPU  120  and timer sensitive enough to detect the change in cycle time. These changes may be small, and thus difficult to detect. In this embodiment, the carbonation cycle (and therefore also the agitation) is not set to run for a predetermined amount of time; rather, the cycle continues until a particular spacing of highs and lows occurs. This provides the added benefit of maximizing the efficiency of the machine, since the machine will not run any longer (or shorter) than necessary. 
     Additional components of the user interface may include an indicator light that is on when the system is powered up, thus indicating to the user that the device is ready for use. A further light may be controlled by the CPU  120 , which may activate the light to indicate that the transducer  160  is measuring a certain pressure level. Yet another light may indicate that the above described agitation process is completed, and it is safe to remove the mixing vessel. This light may be activated by the CPU  120  when the pressure level in the mixing vessel  140  has dropped below a certain level. For example, as a safety feature, it may be desirable to warn the user not to open the mixing vessel  140  until it contains less than 20 PSI. 
     After the carbonation cycle is finished, the excess pressurized CO2 is vented. The venting may occur through an outlet tube  172  connected to the mixing vessel  140 , or the inlet tube  154  may be configured to also allow the release of pressure. The outlet tube may contain an outlet valve  170 , which is controlled by the CPU  120 . Once the CPU  120  has finished the carbonation cycle, the CPU  120  activates the outlet valve  170  to vent the excess CO2 pressure. The outlet valve  170  may further comprise a bleeder valve that can be adjusted to slow down the release of gas exiting the mixing vessel  140 . Reducing the flow rate of the gas exiting the mixing vessel  140  has the added benefit of reducing the amount of foam that would be produced if the mixing vessel were rapidly vented. 
     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.