Abstract:
A self-contained, modular proportioner unit includes a frame, a water handling assembly supported by the frame, a syrup handling assembly supported by the frame, and a controller supported by the frame. Each of the water handling assembly, the syrup handling assembly, and the controller are mounted in close relationship with one another, thereby minimizing the size of the proportioner unit.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional Application No. 60/356,529 filed Feb. 13, 2002. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention relates to beverage blending systems, and more particularly to beverage blending systems designed for brix blending.  
         BACKGROUND OF THE INVENTION  
         [0003]    Many prior art beverage processing systems exist for blending together water and a syrup to yield a soft-drink product. One example of a prior art beverage processing system is illustrated schematically in FIG. 1. The prior art system  10  includes a deaeration stage having a deaeration vessel  14  where air is removed from a supply of treated water using CO 2  injection and a vacuum pump  18 . The water is recirculated through the vessel  14  by a recirculating pump  22 .  
           [0004]    The deaerated water is then pumped via a water pump  26  into one or more water reservoirs  30  for the proportioning stage. The proportioning stage also includes one or more syrup reservoirs  34  supplied with a desired syrup. The water and syrup levels within the respective reservoirs are carefully controlled and held constant. CO 2  is also present in the water reservoirs  30  and the syrup reservoir  34 . The water and the syrup are fed via gravity into a mixing chamber  38  using the “head-over-orifice” principle. Specifically, water flows into the mixing chamber  38  through an adjustable water micrometer  42  and syrup flows into the mixing chamber through a fixed orifice  46 . The mixing chamber  38  is operated at a pressure that is less than atmospheric pressure so the water and syrup orifices  42  and  46  perform as though there were a ten to twenty foot column of liquid above them, depending on the operator settings.  
           [0005]    The water and syrup are mixed in the mixing chamber  38  and then pumped via a mix pump  50  to the carbonating stage of the system  10 . The carbonating stage includes a carbonation tank  54  where CO 2  is absorbed by the water/syrup mixture. A booster pump  58  then helps pump the carbonated product to the filler (not shown) for filling into the desired containers.  
           [0006]    With a typical prior art system like the one shown in FIG. 1, all of the components are packaged together in a tight, self-contained configuration to facilitate installation and to reduce space consumption in the processing plants. Usually, the components are all mounted on a single frame or skid that can be readily moved from place to place using a fork truck.  
         SUMMARY OF THE INVENTION  
         [0007]    Head-over-orifice type proportioning systems, also known as volumetric proportioning or metering systems, are somewhat problematic in that the accuracy of ingredient metering can be affected by variations in temperature, pressure, and viscosity. Typical volumetric proportioning systems achieve a blending accuracy on the order of about ±0.10° brix to ±0.05° brix during steady-state operation. Degrees brix is a measure of blending accuracy, i.e., how much beverage syrup is blended with water. In addition to the relatively low blending accuracy at steady-state, volumetric proportioning systems also generate significant product loss at startup and run-out. Much of this loss can be attributed to operator error during product changeover.  
           [0008]    Hundreds of complete beverage processing systems utilizing volumetric proportioning systems are currently in use around the world. These systems are expensive, and the decision to replace such a system with a new, complete system capable of achieving better proportioning performance is difficult to justify. Therefore, a need exists for an improved proportioning unit that can be quickly and easily added as an upgrade to existing blending systems for a fraction of the cost associated with total system replacement. The improved unit should have a compact, modular design suited for quick and easy installation and minimal space requirements. Improved blending accuracy and reduced product loss should also be achieved.  
           [0009]    The invention provides such an improved proportioning unit upgrade. More specifically, the invention provides a self-contained proportioner unit configured to be substituted for an existing proportioner of a complete beverage mixing system. The proportioner unit includes a frame, a water handling assembly supported by the frame, a syrup handling assembly supported by the frame, and a controller supported by the frame. Each of the water handling assembly, the syrup handling assembly, and the controller are mounted in close relationship with one another, thereby minimizing the size of the proportioner unit.  
           [0010]    Once the proportioner unit is placed adjacent the existing beverage blending system, the existing integrated proportioner is removed or otherwise rendered inoperable. Water and syrup supplies are routed into the new proportioner unit and the blended syrup/water mixture is routed back into the existing carbonation tank, effectively bypassing the old proportioner. The water and syrup handling assemblies are equipped with conveniently-located inlet valves that facilitate making connections with the existing deaeration tank and syrup supply tanks. Likewise, the syrup/water mixture outlet is easily connected to the existing system for fluid communication with the carbonation tank.  
           [0011]    The proportioner unit preferably utilizes mass flow metering technology automatically controlled by the controller. Coriolis-type flow meters are used in the water and syrup handling assemblies and permit the product to be blended on a weight basis rather than a volume basis, yielding higher blending accuracy at startup, steady-state, and run-out. Additionally, the mass flow meters in combination with the controller software operate to greatly reduce the product loss. The controller of the proportioner unit can also be used to control all of the other functions of the existing blending system, thereby eliminating much of the older, relay contact technology being used.  
           [0012]    The invention also provides a method of upgrading a pre-existing beverage blending system having an integral proportioner to achieve improved proportioning performance and accuracy. The method includes providing a self-contained proportioner unit in nearby relation to the pre-existing system and bypassing the pre-existing integral proportioner. Bypassing is achieved by directing a water supply and a syrup supply from the pre-existing system into the self-contained proportioner unit for blending, and then directing the blended water and syrup mixture back into the pre-existing system. The pre-existing integral proportioner can be rendered inoperable and left in place, or can be removed from the existing system altogether.  
           [0013]    Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description and drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a schematic illustration of a prior art beverage processing system.  
         [0015]    [0015]FIG. 2 is a front view of a self-contained beverage proportioner unit embodying the invention.  
         [0016]    [0016]FIG. 3 is a rear view of the beverage proportioner unit of FIG. 2.  
         [0017]    [0017]FIG. 4 is a side view of the beverage proportioner unit of FIG. 2.  
         [0018]    [0018]FIG. 5 is a perspective view showing the water handling assembly and the syrup handling assembly of the beverage proportioner unit.  
         [0019]    [0019]FIG. 6 is a schematic illustration showing the proportioner unit connected to a carbonation tank. 
     
    
       [0020]    Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    FIGS.  2 - 5  illustrate a proportioner unit  100  embodying the present invention. As will be described in greater detail below, the proportioner unit  100  is configured to take the place of the proportioning stage components shown in FIG. 1, including the water reservoirs  30 , the syrup reservoirs  34 , the mixing chamber  38  and the orifices  42  and  46 . Referring again to FIG. 1, the proportioner unit  100  is configured to bypass the existing proportioner at bypass or redirect points W, S, and M. In other words, the proportioner unit  100  is coupled to the existing water supply line at or near the bypass point W, the existing syrup supply line at or near the bypass point S, and the mixed fluid line at or near the redirect point M. Any suitable plumbing configurations can be used to effectuate the bypassing and redirecting of the fluids. The existing integral proportioner of the prior art system  10  can be rendered inoperable and left in place, or alternatively can be removed.  
         [0022]    Referring now to FIGS.  2 - 5 , the proportioner unit  100  includes a frame  104  having spaced apart, substantially horizontal base sections  108 . Each base section  108  includes one or more mounting feet  110  configured to secure the frame  104  to the underlying surface. A substantially vertical leg section  112  extends from each of the base sections  108 . Substantially horizontal cross-members  116  extend between the leg sections  112 . Angled brace sections  120  (only one is shown in FIG. 4) extend between each leg section  112  and its corresponding base section  108  for added support. In the illustrated embodiment, the frame  104  is constructed of aluminum, stainless steel, or other metal tubing using conventional welding techniques.  
         [0023]    The frame  104  supports a water handling assembly  124 . In the illustrated embodiment, the water handling assembly  124  is coupled to the frame  104  with brackets  126  mounted to the leg sections  112  and the upper-most cross-member  116 . Of course, the water handling assembly  124  could also be coupled in other ways to other parts of the frame  104 .  
         [0024]    The water handling assembly  124  includes a main water line  128  having an inlet  132  for connection with the existing water supply system at the bypass point W (see FIG. 1). Downstream of the inlet  132  is a pressure transducer  136  for monitoring the water pressure in the line  128 . A butterfly valve  140  is downstream of the transducer  136  and can be adjusted as desired to change the line pressure and flow. Downstream of the butterfly valve  140  is a mass flow meter  144 . In the illustrated embodiment, the mass flow meter  144  is a Coriolis type meter, however other types of mass flow meters can also be used. Data outputs from the meter  144  include flow data and temperature data.  
         [0025]    Downstream of the meter  144  is a flow control valve  148  that controls the overall flow of water through the line  128 . The illustrated flow control valve  148  is an I/P type valve that converts an input current signal (mA) to an output air pressure signal (psi) to open and close the valve as desired. The air supply to the flow control valve  148  comes from an instrument air line  150  (see FIG. 6) in the plant. Of course, other types of non-pneumatic flow control valves, such as electrically or mechanically operated valves can also be used, however the illustrated pneumatic valve is preferred due to the rapid response times achieved.  
         [0026]    Downstream of the flow control valve  148  is a tee joint  152  having a syrup/water mixture outlet  156 . The outlet  156  is configured for connection with the existing mixed fluid line at the redirect point M (see FIG. 1). The tee joint  152  also includes a syrup inlet  160  for the introduction of syrup into the tee joint  152  for mixing, as will be further described below.  
         [0027]    The frame  104  also supports a syrup handling assembly  164 . In the illustrated embodiment, the syrup handling assembly  164  is coupled to the frame  104  with brackets  166  mounted to the lower-most cross-member  116 . Of course, the syrup handling assembly  164  could also be coupled in other ways to other parts of the frame  104 .  
         [0028]    The syrup handling assembly  164  includes a main syrup line  168  having an inlet  172  for connection with the existing syrup supply system at the bypass point S (see FIG. 1). If needed, an optional syrup booster pump  174  (see FIG. 6) can be incorporated upstream or downstream of the inlet  172 . The booster pump  174  can be connected to the frame  104  or can stand alone separately from the proportioner unit  100 . If the booster pump  174  is used, an optional pressure regulator valve  175  (see FIG. 6) can be used to help regulate the line pressure downstream of the booster pump  174 . In the illustrated embodiment, the pressure regulator valve  175  is pneumatically operated with air from the air supply line  150 .  
         [0029]    Downstream of the inlet  172  is a pressure transducer  176  for monitoring the syrup pressure in the line  168 . A butterfly valve  180  is downstream of the transducer  176  and can be adjusted as desired to change the line pressure and flow. Downstream of the butterfly valve  180  is a mass flow meter  184 . In the illustrated embodiment, the mass flow meter  184  is a Coriolis type meter, however other types of mass flow meters can also be used. The data outputs from the meter  184  include flow data and temperature data, similar to the meter  144  in the water handling assembly  124 . In addition, the meter  184  in the syrup handling assembly  164  also provides density data.  
         [0030]    Downstream of the meter  184  is a flow control valve  188  that controls the overall flow of syrup through the line  168 . The illustrated flow control valve  188  operates in the same manner described above with respect to the flow control valve  148  in the water handling assembly  124 .  
         [0031]    Downstream of the flow control valve  188  are a pair of valves  192  and  196  that operate to direct the flow through the line  168  in one of two directions. At a first setting, the flow in line  168  is directed out of a drain  200  and is not permitted to enter the tee joint  152  at the syrup inlet  160 . At the second setting, the flow in line  168  bypasses the drain  200  and is permitted to enter the tee joint  152  at the syrup inlet  160  for mixing with water in the water line  128 . The purpose of these two settings will be described in greater detail below.  
         [0032]    The proportioner unit  100  further includes a cabinet  204  mounted on the frame  104 . The cabinet  204  houses, among other things, a programmable logic controller (PLC) generally indicated as  208  in FIG. 2. The PLC  208  controls the operation of the proportioner unit  100  and can also be used to control the operation of the existing or newly-added components in the beverage mixing system  10 . In this manner, much of the older relay contact technology used in the older existing system  10  can be eliminated.  
         [0033]    For example, the PLC  208  can be used to control and regulate the pressure inside the carbonation tank  54 . As seen in FIG. 6, a pressure transducer  209 , a vent valve  210 , and a CO 2  supply valve  211  (see FIG. 6) can be connected to the carbonation tank  54  and electrically connected to the PLC  208  so the PLC  208  can control and regulate the CO 2  pressure in the tank  54  to properly carbonate the product. The PLC  208  can also be used to control the clean-in-place (CIP) routine. Additional analog input signals can also be provided to the PLC  208  for monitoring and controlling other pressures, temperatures, and the like.  
         [0034]    In the illustrated embodiment, the PLC  208  is an Allen-Bradley 5000 series controller that is PC based and that includes a color touch screen interface  212  for easy and intuitive operator control. The PLC  208  can store a large number of product recipes, including settings for carbonation pressure and beverage brix targets. The PLC  208  and/or the PC is equipped with a modem (not shown) to provide remote access for technicians.  
         [0035]    In addition to housing the PLC  208  and the PC, the cabinet  204  can house some or all of the pneumatic system  216  (see FIG. 6) used to control the optional pressure regulator  175  and the flow control valves  148  and  188  in a conventional manner.  
         [0036]    The proportioner unit  100  has a relatively small footprint, making the unit  100  well suited for use as a modular, compact upgrade kit to existing prior art blending systems  10  having integral volumetric proportioners. In the illustrated embodiment, the unit  100  has an overall width W′ (see FIG. 2) of approximately forty to forty-five inches, and more preferably about forty-two inches. The unit  100  has an overall height H of approximately seventy-four to seventy-eight inches, and more preferably about seventy-six inches. The unit  100  has an overall depth D (see FIG. 4) of approximately twenty-eight to thirty-two inches, and more preferably about thirty inches.  
         [0037]    With reference to FIG. 6, the operation of the proportioner unit  100  will now be described. The operation is automatically controlled by the software loaded onto the PLC  208 . At system startup, the syrup line  168  is filled with deaerated water that was previously used to flush the line  168  between a product changeover or to flush the line  168  after a clean-in-place (CIP) routine.  
         [0038]    Once the operator has selected a product recipe, syrup is sent from a syrup supply and enters the syrup inlet  172 . The optional booster pump  174  and pressure regulator  175  can be employed to achieve the desired syrup pressure and flow. This beginning stage is known as the “syrup push,” where the syrup is used to push or purge the water from the line  168  and out of the drain  200 . During the syrup push, the meter  184  is monitoring the density of the water/syrup mixture. When the water/syrup mixture reaches a predetermined density, which the PLC  208  converts to a percent solid value (approximately thirty-five percent solid in the illustrated embodiment), the PLC  208  determines that the water/syrup mixture has a sufficient amount of syrup to begin blending and making product. With this method, the proportioner unit  100  provides for a no-dump startup. In other words, no blended product is wasted during the time when the system is approaching steady-state operation, and the proportioner unit  100  maximizes the amount of product that can be blended at startup.  
         [0039]    When the syrup content is sufficient to begin blending, the valves  192  and  196  are switched to the second setting, where the drain  200  is closed and the water/syrup mixture enters the tee joint  152  at the syrup inlet  160 . The operator then starts the blending process so that water from the water handling assembly  124  and syrup from the syrup handling assembly  164  are blended in the tee joint  152  and continue mixing on the way to the carbonation tank  54 .  
         [0040]    The PLC continuously monitors the density of the water/syrup mixture passing through the flow meter  184  and adjusts the flow of syrup through the line  168  using the flow control valve  188 . This continual adjustment provides accurate brix blending as the water/syrup mixture in the syrup line  168  approaches one hundred percent syrup (i.e., the water present in the line  168  at startup is substantially purged). In the illustrated embodiment, the flow of water through the main water line  128  remains constant after the proper setting is achieved with the flow control valve  148 , and only the flow in the syrup line  168  is varied.  
         [0041]    In addition to compensating for the proportionally changing water/syrup mixture in the syrup line  168  at startup, the PLC  208  also takes into account the fact that some residual water will remain in the carbonation tank  54  and in the filler bowl (not shown) after a changeover. Therefore, the PLC  208  artificially elevates the target product brix value for a predetermined amount of blended product. This means that the blended mixture exiting at the mixture outlet  156  will have a slightly higher syrup content to accommodate the expected dilution caused by the residual water in the carbonation tank  54  and the filler bowl. This operation also helps to achieve the no-dump startup.  
         [0042]    The proportioner unit  100  operates in a similar manner at syrup run-out. When the syrup supply tank is empty, the operator initiates the end-of-run cycle, wherein the remaining syrup in the syrup line  168  is pushed through by water introduced into the line  168 . The meter  184  continuously monitors the density of the syrup/water mixture in the syrup line  168 . When the syrup/water mixture reaches a predetermined density, which the PLC  208  converts to a percent solid value (again, approximately thirty-five percent solid in the illustrated embodiment), the PLC  208  determines that the syrup/water mixture no longer has a sufficient amount of syrup to continue blending and making product. At this point, blending is stopped and the valves  192  and  196  are set to the first position so that the remaining syrup/water mixture in the line  168  can be purged via the drain  200 . With this technique, the proportioner unit  100  maximizes the amount of product that can be blended at syrup run-out.  
         [0043]    The PLC  208  controls brix blending based on mass metering as opposed to volumetric metering used in many prior art proportioners. Because mass metering is unaffected by temperature, pressure, and viscosity variations, the proportioner unit  100  achieves a blending accuracy of approximately ±0.03° brix over the entire blending cycle, whereas the prior art volumetric metering proportioners typically achieve only ±0.10° brix to ±0.05° brix, and only during steady-state operation. Mass metering also permits the proportioner unit  100  to perform automatic flavor cuts and changeovers.  
         [0044]    The software in the PLC  208  operates to achieve brix blending in the following manner. First, the final product brix value stored in the PLC  208  with the product recipe is converted to a final product solid fraction value. Of course, it is recognized that fractional values can be readily converted to percentage values (multiplying by 100%) so that solid fraction values and percent solid values can be used interchangeably. The algorithm for the conversion between the final product brix and the final product solid fraction is stored in the PLC  208  and is well known to those skilled in the art of brix blending. By converting from the final product brix value to the final product solid fraction value, and by using the solid fraction values throughout, the algorithm eliminates the use of brix-to-solid offsets or multipliers that can lead to less accurate blending.  
         [0045]    The final product solid fraction value can be represented by the following equation:  
         Solid Fraction(Final Product)=[ Wt  Solid(Final Product)]/[Total  Wt (Final Product)] 
         [0046]    As the syrup/water mixture or the syrup alone flows through the meter  184 , the density value is converted by the PLC  208  into a syrup solid fraction value. The syrup solid fraction value can be represented by the following equation:  
         Solid Fraction (Syrup)=[ Wt  Solid(Syrup)]/[Total  Wt (Syrup)] 
         [0047]    Next the PLC  208  calculates a syrup recipe fraction according to the following equation:  
         Syrup Recipe Fraction=Solid Fraction(Final Product)]/Solid Fraction (Syrup)] 
         [0048]    With the syrup recipe fraction determined, the PLC  208  can determine the desired water recipe fraction using the equation:  
         Water Recipe Fraction=1−Syrup Recipe Fraction  
         [0049]    Next, the total system flow is determined based on a preset water flow rate through the water line  128 :  
         Total System Flow=[Preset water flow rate( lb/hr )]/[Water Recipe Fraction] 
         [0050]    Once the total system flow is known, the desired syrup flow rate can be determined:  
         Syrup Flow Rate=Total System Flow*Syrup Recipe Fraction  
         [0051]    This sequence of calculations is continuously performed by the PLC  208  to set and vary the metering position of the flow control valve  188  in the syrup handling assembly  164 . Because the density of the syrup is continuously monitored by the flow meter  184 , the actual Solid Fraction (Syrup) value is always known and is used to continuously repeat the above-described algorithm and determine the instantaneous syrup flow rate necessary to blend to brix.  
         [0052]    It is this continuous calculation and the corresponding actuation of the flow control valve  188  that automatically and instantaneously compensates for the varying proportions of syrup and water in the syrup line  168  at both startup and run-out. Additionally, the algorithm and corresponding flow control valve actuation accommodates for variations and deviations from the manufacturer&#39;s stated syrup brix value/solid fraction value during steady-state operation. This algorithm also permits the temporary, artificial elevation of the final product brix value necessary to account for the residual water in the carbonation tank  54  and the filler bowl at startup.  
         [0053]    All of the features and techniques described above make the self-contained proportioner unit  100  a viable and economically-justifiable upgrade or retrofit to pre-existing beverage blending systems incorporating less accurate proportioners.  
         [0054]    Additional features of the invention are set forth in the following claims.