Patent Publication Number: US-2021187527-A1

Title: Liquid dispensing system comprising an unitary dispensing nozzle

Description:
FIELD OF THE INVENTION 
     The present invention relates to liquid dispensing systems for dispensing two or more liquids into a container at high filling speeds to improve homogeneous mixing of such liquids. 
     BACKGROUND OF THE INVENTION 
     Liquid dispensing systems for simultaneously dispensing two or more liquids (e.g., a concentrate and a diluent) into a container are well known. Such liquid dispensing systems typically comprise so-called co-injection nozzles for concurrently but separately dispensing two or more liquids at high filling speeds. 
     When the liquids to be dispensed are significantly different in composition, viscosity, solubility, and/or miscibility, it is difficult to ensure homogeneous mixing of such liquids in the container. Further, it is inevitable that when dispensed into the container at relatively high filling speed, the liquids tend to splash, and one or more of the liquids may form hard-to-remove residues on the container wall, which may further exacerbate the issue of in-homogenous mixing. Still further, most of the co-injection nozzles commercially available today are not suitable for high-speed liquid filling, because they contain various moving parts (e.g., O-rings, seal gaskets, bolts, screws, etc.) that may become loose under high pressure, and they also may create dead spaces where liquids can be trapped, which may pose challenges for cleaning and result in poor sanitization. Further, when the liquids are dispensed at high filling speeds, it is difficult to ensure precision dosing of such liquids and 100% shut-off of the liquid flow when the dosing is completed. 
     Therefore, there is a need for liquid dispensing systems with co-injection nozzles that can accommodate high speed liquid filling, with improved homogeneity in the mixing results and reduced formation of residues on the container wall. There is also a need for liquid dispensing systems with improved precision dosing and complete shut-off. 
     SUMMARY OF THE INVENTION 
     The present invention meets the above-mentioned needs by providing a liquid dispensing system for dispensing two or more liquids into a container, comprising:
         (A) a first liquid source for supplying a first liquid;   (B) a second liquid source for supplying a second liquid that is different from said first liquid in composition, viscosity, solubility, and/or miscibility;   (C) a unitary dispensing nozzle in fluid communication with said first and second liquid sources, said unitary dispensing nozzle is an integral piece free of any movable parts and comprises:
           (a) a first end;   (b) a second, opposite end;   (c) one or more sidewalls between said first and second ends;   (d) one or more first flow passages for flowing the first liquid through said nozzle, wherein each of said first flow passages is defined by a first inlet and a first outlet; wherein said first inlet(s) is/are located at the first end of said nozzle; and wherein said first outlet(s) is/are located at the second end of said nozzle; and   (e) one or more second flow passages for flowing the second liquid through said nozzle, wherein each of said second flow passages is defined by a second inlet and a second outlet; wherein said second inlet(s) is/are located on or near at least one of said sidewalls; wherein said second outlet(s) is/are located at the second end of said nozzle so that said one or more second flow passages extend through said at least one of the sidewalls and the second end of said nozzle; and wherein said second outlet(s) is/are substantially surrounded by said first outlet(s),   
           (D) a first valve assembly located at or near the first end of said unitary dispensing nozzle for opening and closing said one or more first flow passages; and   (E) a second valve assembly located at or near at least one of said sidewalls for opening and closing said one or more second flow passages.       

     Preferably, the first liquid source is controlled by a servo-driven pump, more preferably a servo-driven positive displacement pump, most preferably a servo-driven rotary positive displacement pump. 
     Preferably, the second liquid source is controlled by a servo-driven pump, more preferably a servo-driven piston pump, most preferably a servo-driven piston pump with a rotary valve. 
     These and other aspects of the present invention will become more apparent upon reading the following detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a unitary dispensing nozzle, according to one embodiment of the present invention. 
         FIG. 1B  is the top view of the unitary dispensing nozzle of  FIG. 1A . 
         FIG. 1C  is the bottom view of the unitary dispensing nozzle of  FIG. 1A . 
         FIG. 1D  is a side view of the unitary dispensing nozzle of  FIG. 1A . 
         FIG. 1E  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 1A  along plane I-I. 
         FIG. 1F  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 1A  along a plane that is perpendicular to I-I. 
         FIG. 2A  is a perspective view of a unitary dispensing nozzle, according to another embodiment of the present invention. 
         FIG. 2B  is the top view of the unitary dispensing nozzle of  FIG. 2A . 
         FIG. 2C  is the bottom view of the unitary dispensing nozzle of  FIG. 2A . 
         FIG. 2D  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 2A  along plane 
         FIG. 2E  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 1A  along a plane that is perpendicular to II-II. 
         FIG. 3A  is a perspective view of a unitary dispensing nozzle, according to yet another embodiment of the present invention. 
         FIG. 3B  is the top view of the unitary dispensing nozzle of  FIG. 3A . 
         FIG. 3C  is the bottom view of the unitary dispensing nozzle of  FIG. 3A . 
         FIG. 3D  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 3A  along plane 
         FIG. 3E  is a cross-sectional view of the unitary dispensing nozzle of  FIG. 1A  along a plane that is perpendicular to 
         FIG. 4  is a schematic view of a liquid dispensing system, according to one embodiment of the present invention. 
         FIG. 5  is a perspective view of parts of a liquid dispensing system, according to one embodiment of the present invention. 
         FIG. 6  is a cross-sectional view of a unitary dispensing nozzle, a first valve assembly and a second valve assembly from  FIG. 5 . 
         FIG. 7  is a cross-sectional view of a servo-driven piston pump with a ceramic three-way rotary valve from  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Features and benefits of the various embodiments of the present invention will become apparent from the following description, which includes examples of specific embodiments intended to give a broad representation of the invention. Various modifications will be apparent to those skilled in the art from this description and from practice of the invention. The scope of the present invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. 
     As used herein, articles such as “a” and “an” when used in a claim, are understood to mean one or more of what is claimed or described. The terms “comprise,” “comprises,” “comprising,” “contain,” “contains,” “containing,” “include,” “includes” and “including” are all meant to be non-limiting. 
     As used herein, the terms “substantially free of” or “substantially free from” means that the indicated space is present in the volume of from 0% to about 1%, preferably from 0% to about 0.5%, more preferably from 0% to about 0.1%, by total volume of the unitary dispensing nozzle. 
     The unitary dispensing nozzle used in the present invention is made as an integral piece, without any moving parts (e.g., O-rings, sealing gaskets, bolts or screws). Such an integral structure renders it particularly suitable for high speed filling of viscous liquid, which typically requires high filling pressure. Such a unitary dispensing nozzle can be made by any suitable material with sufficient tensile strength, such as stainless steel, ceramic, polymer, and the like. 
     Preferably, the unitary dispensing nozzle of the present invention is made of stainless steel. 
     The unitary dispensing nozzle of the present invention may have an average height ranging from about 3 mm to about 200 mm, preferably from about 10 to about 100 mm, more preferably from about 15 mm to about 50 mm. It may have an average cross-sectional diameter ranging from about 5 mm to about 100 mm, preferably from about 10mm to about 50mm, more preferably from about 15 mm to about 25 mm. 
     Such dispensing nozzle provides two or more fluid passages for simultaneously or substantially simultaneously dispensing two or more liquids of different composition, viscosity, solubility, and/or miscibility into a container. For example, one of the liquids can be a minor liquid feed composition, and the other can be a major liquid feed composition (i.e., the liquid making up the majority weight of the final liquid mixture). The container has an opening into which the two or more liquids are dispensed, while the total volume of the container may range from about 10 ml to about 10 L, preferably from about 20 ml to about 5 L, more preferably from about 50 ml to about 4 L. 
       FIGS. 1A-1F  show a unitary dispensing nozzle, according to one embodiment of the present invention. Specifically, nozzle  10  has a first end  12  and a second, opposite end  14 . Preferably but not necessarily, the first end  12  is on top, while the second, opposite end  14  is at the bottom. More preferably, the first and second ends  12  and  14  have relatively planar surfaces. One or more sidewalls  16  are located between the first and second ends  12  and  14 . Such sidewalls can be either planar or cylindrical. 
     The nozzle  10  contains a plurality of first flow passages  11  for flowing a first fluid (e.g., a major liquid feed composition) therethrough. Each of the first flow passages  11  is defined by a first inlet  11 A located at the first end  12  and a first outlet  11 B located at the second end  14 , as shown in  FIG. 1E . Further, the nozzle  10  contains a second flow passage  13  for flowing a second fluid (e.g., a minor liquid feed composition) therethrough. The second flow passage  13  is defined by a second inlet  13 A located near the sidewall  16  and a second outlet  13 B located at the second end  14 , so that the second flow passage  13  extends through the sidewall  16  and the second end  14 , as shown in  FIG. 1E . 
     The first and second outlets  11 B and  13 B can have any suitable shapes, e.g., circular, semicircular, oval, square, rectangular, crescent, and combinations thereof. Preferably but not necessarily, both the first and second outlets  11 B and  13 B are circular, as shown in  FIG. 1C . Further, the second outlet  13 B is substantially surrounded by the plurality of first outlets  11 B, as shown in  FIG. 1C . In the event that the minor liquid feed composition is prone to form hard-to-remove residues once it is deposited on the container wall, such an arrangement is particularly effective for preventing the minor liquid feed composition from depositing on the container wall, because the minor feed flow existing the second outlet  13 B will be substantially surrounded by a plurality of major feed flows existing the first outlets  11 B, which form a “liquid shroud” around the minor feed flow and thereby reducing formation of hard-to-remove residues by the minor feed on the container wall. 
     The plurality of major feed flows can be configurated to form a diverging “liquid shroud” around the minor feed flow. Alternatively, the plurality of major feed flows may be substantially parallel to each other, thereby forming a parallel “liquid shroud” around the minor feed flow. Such a parallel arrangement of the major feed flows is particularly preferred in the present invention because it provides a greater local turbulence around the minor feed flow inside the container and enables a better, more homogenous mixing result. 
     Still further, the nozzle  10  is substantially free of any dead space (i.e., spaces that are not directly in the flow passages and therefore can trap liquid residues). Therefore, it is easy to clean and is less likely to cause cross-contamination when switching between different liquid feeds. 
     Preferably, but not necessarily, the ratio of the total cross-sectional area of the first outlets  11 B over the total cross-sectional area of the second outlet  13 B may range from about 5:1 to about 50:1, preferably from about 10:1 to about 40:1, and more preferably from about 15:1 to about 35:1. Such ratio ensures a significantly large major-to-minor flow rate ratio, which in turn enables more efficient dilution of the minor ingredient in the container, ensuring that there is no ‘hot spots’ of localized high concentrations of minor ingredient in the container. 
       FIGS. 2A-2E  show a unitary dispensing nozzle, according to another embodiment of the present invention. Specifically, nozzle  20  has a first end  22  and a second, opposite end  24 . Both the first and second ends  22  and  24  have relatively planar surfaces. A cylindrical sidewall  26  is located between the first and second ends  22  and  24 . 
     The nozzle  20  contains a plurality of first flow passages  21  for flowing a first fluid (e.g., a major liquid feed composition) therethrough. Each of the first flow passages  21  is defined by a first inlet  21 A located at the first end  22  and a first outlet  21 B located at the second end  24 , as shown in  FIGS. 2B, 2C and 2E . Further, the nozzle  20  contains a second flow passage  23  for flowing a second fluid (e.g., a minor liquid feed composition) therethrough. The second flow passage  23  is defined by a second inlet  23 A located near the cylindrical sidewall  26  and a second outlet  23 B located at the second end  24 , so that the second flow passage  23  extends through the cylindrical sidewall  26  and the second end  24 , as shown in  FIGS. 2C and 2D . 
     All of the first outlets  21 B have a crescent shape, while such crescents are arranged in a concentric manner with substantially the same radius center. In contrast, the second outlet  23 B is circular in shape. Further, the second outlet  23 B is located at the radius center of the first outlets  21 B and is substantially surrounded by the plurality of first outlets  21 B, as shown in  FIG. 2C . In the event that the minor liquid feed composition is prone to form hard-to-remove residues once it is deposited on the container wall, such an arrangement is particularly effective for preventing the minor liquid feed composition from depositing on the container wall, because the minor feed flow existing the second outlet  23 B will be substantially surrounded by the plurality of major feed flows existing the first outlets  21 B, which form a “liquid shroud” around the minor feed flow and thereby reducing formation of hard-to-remove residues by the minor feed on the container wall. 
     The nozzle  20  is also substantially free of any dead space and is therefore easy to clean with a reduced risk of cross-contamination when changing liquid feeds. 
     Preferably, but not necessarily, the ratio of the total cross-sectional area of the first outlets  21 B over the total cross-sectional area of the second outlet  23 B may range from about 5:1 to about 50:1, preferably from about 10:1 to about 40:1, and more preferably from about 15:1 to about 35:1. 
       FIGS. 3A-3D  show a unitary dispensing nozzle, according to yet another embodiment of the present invention. Specifically, nozzle  30  has a first end  32  and a second, opposite end  34 . 
     Both the first and second ends  32  and  34  have relatively planar surfaces. A cylindrical sidewall  36  is located between the first and second ends  32  and  34 . 
     The nozzle  30  contains a plurality of first flow passages  31  for flowing a first fluid (e.g., a major liquid feed composition) therethrough. Each of the first flow passages  31  is defined by a first inlet  31 A located at the first end  32  and a first outlet  31 B located at the second end  34 , as shown in  FIGS. 3B, 3C and 3E . Further, the nozzle  30  contains a second flow passage  33  for flowing a second fluid (e.g., a minor liquid feed composition) therethrough. The second flow passage  33  is defined by a second inlet  33 A located near one side of the cylindrical sidewall  36  and a second outlet  33 B located at the second end  34 , so that the second flow passage  33  extends through the cylindrical sidewall  36  and the second end  34 , as shown in  FIGS. 3C and 3D . Still further, the nozzle  30  contains a third flow passage  35  for flowing a third fluid (e.g., an additional minor liquid feed composition) therethrough. The third flow passage  35  is defined by a third inlet  35 A located near the other side of the cylindrical wall  36  and a third outlet  35 B located at the second end  34 , so that the third flow passage  35  extends through the cylindrical sidewall  36  (at an side opposite to the second flow passage  33 ) and the second end  34 , as shown in  FIGS. 3A, 3C and 3D . 
     All of the first outlets  31 B have a crescent shape, while such crescents are arranged in a concentric manner with substantially the same radius center. In contrast, the second outlet  33 B and the third outlet  35 B are circular in shape. Further, the second outlet  33 B is located at the radius center of the first outlets  31 B, while the third outlet  35 B is located adjacent to the radius center of the first outlets  31 B. In this manner, both the second and third outlets  33 B and  35 B are substantially surrounded by the plurality of first outlets  31 B, as shown in  FIG. 3C . In the event that either or both of the minor liquid feed compositions are prone to form hard-to-remove residues once deposited on the container wall, such an arrangement functions to minimize the deposition of minor liquid feed compositions onto the container wall, because the minor feed flows existing the second outlet  33 B and the third outlet  35 B will be substantially surrounded by the plurality of major feed flows existing the first outlets  31 B, which form a “liquid shroud” around the minor feed flows and thereby reducing formation of hard-to-remove residues by the minor feeds on the container wall. 
     The nozzle  30  is also substantially free of any dead space and is therefore easy to clean with a reduced risk of cross-contamination when changing liquid feeds. Preferably, but not necessarily, the ratio of the total cross-sectional area of the first outlets  31 B over the total cross-sectional area of the second outlet  33 B may range from about 5:1 to about 50:1, preferably from about 10:1 to about 40:1, and more preferably from about 15:1 to about 35:1. Similarly, the ratio of the total cross-sectional area of the first outlets  31 B over the total cross-sectional area of the third outlet  35 B may range from about 5:1 to about 50:1, preferably from about 10:1 to about 40:1, and more preferably from about 15:1 to about 35:1. 
       FIG. 4  is a schematic view of a liquid dispensing system  40  according to one embodiment of the present invention. Specifically, such liquid dispensing system  40  comprises: (A) a first liquid source  41  for supplying a first liquid (not shown); (B) a second liquid source  43  for supplying a second liquid (not shown); (C) a unitary dispensing nozzle  45  as described hereinabove, which is in fluid communication with the first and second liquid sources  41  and  43 ; (D) a first valve assembly  47  located at or near a first end of the unitary dispensing nozzle  45  for opening and closing one or more first flow passages  452  of the first liquid; and (E) a second valve assembly  49  located at or near at least one of sidewalls of the unitary dispensing nozzle  45  for opening and closing one or more second flow passages  454  of the second liquid. The first liquid is preferably stored in a storage tank under atmospheric pressure. To ensure sufficient mixing of liquids in the container, it is necessary that the first liquid, i.e., the major feed liquid composition, is filled by the unitary dispensing nozzle  45  at a significantly high speed so as to generate a sufficiently strong influx and turbulence in the container. Preferably, the major feed liquid composition is filled at an average flow rate ranging from about 50 ml/second to about 10 L/second, preferably from about 100 ml/second to about 5 L/second, more preferably from about 500 ml/second to about 1.5 L/second. To achieve such a high filling speed of the major feed liquid composition while maintaining dosing precision, it is preferred that the first liquid source  41  is controlled by a servo-driven pump  410 . The servo-driven pump  410  is preferably a servo-driven positive displacement pump, more preferably a servo-driven rotary positive displacement pump, such as the Universal II series Model 018 rotary PD pumps commercially available from Waukesha 
     Cherry-Burrell (Wisconsin, USA). The first fluid supplied by the first liquid source  41  may flow through a flowmeter  412 , which measures the mass or volumetric flow rate of the first fluid to further ensure precision dosing thereof. 
     The first valve assembly  47  located at or near the first end of the unitary dispensing nozzle  45  is preferably actuated by a first remotely mounted pneumatic solenoid  420 , which in turn is in fluid communication with a pressurized air supply  42 . Pressurized air is passed from the air supply  42  through the pneumatic solenoid  420  into said first valve assembly  47  to open and close the one or more first flow passages  452 , thereby controlling the flow of the first liquid through the unitary dispensing nozzle  45 . 
     The second fluid supplied by the second fluid source  43  to the unitary dispensing nozzle  45  is preferably a minor liquid feed composition, and more preferably a liquid with significantly higher viscosity than the major liquid feed composition, which can be filled at an average flow rate ranging from 0.1 ml/second to about 1000 ml/second, preferably from about 0.5 ml/second to about 800 ml/second, more preferably from about 1 ml/second to about 500 ml/second. 
     The second liquid source  43  preferably comprises a pressurized header (not shown) for supplying the second liquid at an elevated pressure (i.e., higher than atmospheric pressure). The second liquid supply  43  is preferably controlled by a servo-driven pump  430 , which is preferably a servo-driven piston pump, more preferably a servo-driven piston pump with a rotary valve. Most preferred servo-driven pump for controlling the second liquid supply  43  is the Hibar 4S series precision rotatory dispensing pump commercially available from Hibar Systems Limited (Ontario, Canada), which comprises a ceramic 3-way rotary valve that is particularly suitable for handling high viscosity liquids. The servo-driven piston pump  430  is preferably actuated by a second remotely mounted pneumatic solenoid  440 , which passes pressurized air from an air source  44  into the rotary valve of the pump  430  to rotate said valve between a dosing mode and a dispensing mode. In said dosing mode, a predetermined amount of said second liquid is dosed by said second liquid source  43  into said servo-driven piston pump  430 ; and in said dispensing mode, said predetermined amount of the second liquid is dispensed by said servo-driven piston pump  430  to said unitary dispensing nozzle  45 . 
     The second valve assembly  49  located at or near at lease one of the sidewalls of the unitary dispensing nozzle  45  preferably comprises an air-operated valve for opening and closing said one or more second flow passages  454  of the unitary dispensing nozzle  45 . The air-operated valve is preferably a pinch valve that opens by flexing an internal membrane (not shown) to allow fluid to flow through, and it is particularly suitable for isolating the fluid from any internal valve parts and ensuring 100% shut-off. Preferably, the air-operated valve is actuated by a remotely mounted pneumatic solenoid. More preferably, the air-operated valve is actuated also by the second remotely mounted pneumatic solenoid  440 . 
       FIG. 5  is a perspective view of parts of a liquid dispensing system  50 , according to one embodiment of the present invention. Specifically, a first liquid source (not shown) controlled by a servo-driven rotary positive displacement pump  510 , which is preferably a Universal II series Model 018 rotary PD pump commercially available from Waukesha Cherry-Burrell (Wisconsin, USA), supplies a low viscosity major feed liquid (not shown) to a unitary dispensing nozzle  55  through a first valve assembly  57 . A second liquid source (not shown) controlled by a servo-driven piston pump  530 , which is preferably a Hibar 4S series precision rotatory dispensing pump commercially available from Hibar Systems Limited (Ontario, Canada) with a ceramic 3-way rotary valve, supplies a high viscosity minor feed liquid (not shown) to the unitary nozzle  55  through a second valve assembly  59 . 
       FIG. 6  is a cross-sectional view of the unitary dispensing nozzle  55 , the first valve assembly  57 , and the second valve assembly  59  from  FIG. 5 . The unitary dispensing nozzle  55  comprises one or more first flow passages  552 , which extend from a first end to a second end of said unitary dispensing nozzle  55  to allow the low viscosity major feed liquid (not shown) to flow therethrough. The unitary dispensing nozzle  55  further comprises one or more second flow passages  554 , which extend from a side wall of the nozzle  55  to the second end thereof to allow the high viscosity minor feed liquid (not shown) to flow therethrough. 
     The first valve assembly  57  located at or near the first end of the unitary dispensing nozzle  55  preferably comprises an air cylinder  571  with an internal piston  572  that divides such air cylinder  571  into an upper chamber  571 A and a lower chamber  571 B, a spring  573 , and a fluid plunger  575 . The internal piston  572  is capable of moving up and down along the air cylinder  571  when pressurized air is passed into the lower or upper chamber  571 A or  571 B of said air cylinder  571 . The fluid plunger  575  is connected with and actuated by said internal piston  572  and said spring  573 . Typically, the fluid plunger  575  is being pushed down by the spring to seat immediately above the one or more first flow passages  552 . When the fluid plunger  575  is in this position, it blocks off the one or more first flow passages  552 , thereby preventing the low viscosity major feed liquid from flowing through said one or more first flow passages  552 . 
     To open the one or more first flow passages  552 , a first remotely mounted pneumatic solenoid (not shown) is triggered to pass pressurized air from an air supply (not shown) into the bottom chamber  571 B of the air cylinder  571  to pressurize said bottom chamber  571 B. When this occurs, the internal piston  572  raises up along the air cylinder  571 . Because the internal piston  572  is directly coupled to the fluid plunger  575 , the upward motion of the internal piston  572  moves the fluid plunger  575  up against the closing force of the spring  573 . When the fluid plunger  575  is moved up and away from the one or more first flow passages  552  (as shown in  FIG. 6 ), the low viscosity major feed fluid is permitted to flow through said one or more first flow passages  552  of the unitary dispensing nozzle  55 . To again close the one or more first flow passages  552 , the first remotely mounted pneumatic solenoid (not shown) is triggered to vent air out of the bottom chamber  571 B of the air cylinder  571  while passing pressurized air from the air supply (not shown) into the upper chamber  571 A of the air cylinder  571 . When this occurs, the internal piston  572  drops down along the air cylinder  571  at the combined forces of the pressurized upper chamber  571 A and the spring  573 , which in turn pushes the fluid plunger  575  down to seat above the one or more first flow passages  552 . Correspondingly, the one or more first flow passages  552  are sealed off, and the flow of the major feed fluid therethrough is stopped. 
     The second valve assembly  59  located at or near a side wall of the unitary dispensing nozzle  55  preferably comprises an air-operated pinch valve  591  having an internal membrane  592 . When the pinch valve  591  is filled with pressurized air, the internal membrane  592  closes and cuts off flow of the high viscosity minor feed liquid into the one or more second flow passages  554 . When the pressurized air is let out of the pinch valve  591 , the internal member  592  flexes to open under the force of the liquid flow, thereby allowing the high viscosity minor feed liquid to flow therethrough into the one or more second flow passages  554 . Preferably, flow of pressurized air in and out of the pinch valve  591  is controlled by a remotely mounted pneumatic solenoid. 
       FIG. 7  is a cross-sectional view of the servo-driven piston pump  530  from  FIG. 5 . Preferably, the servo-driven piston pump  530  comprises a fluid inlet  531 , an inner piston  532 , a fluid dosing chamber  533 , a 3-way ceramic rotary valve  534 , and a fluid outlet  535 . The high viscosity minor feed liquid (not shown) is flown from a pressurized header (not shown) of a second liquid supply (not shown) into the fluid inlet  531  of the servo-driven piston pump  530 . During the dosing mode, the minor feed liquid (not shown) passes from the fluid inlet  531  through the 3-way ceramic rotary valve  534  into the fluid dosing chamber  533  as the inner piston  532  retracts to suck in the minor feed liquid. Once a predetermined amount of the minor feed liquid has been pulled into the fluid dosing chamber  533 , the servo-driven piston pump  530  is ready to move into the dispensing mode. To begin dispensing the minor feed liquid, a remotely mounted pneumatic solenoid is triggered to cause the 3-way ceramic valve to rotate 90 degrees. When the 3-way ceramic valve so rotates, the fluid communication between the fluid inlet  531  and the fluid dosing chamber  533  is cut off, but rather the fluid communication between the fluid dosing chamber  533  and the fluid outlet  535  is open, thereby allowing the predetermined amount of the minor feed liquid to flow from the fluid dosing chamber  533  out of the fluid outlet  535  and into the unitary dispensing nozzle downstream (not shown). Preferably, the remotely mounted pneumatic solenoid described hereinabove (not shown) is also capable of actuating the pinch valve (not shown) located immediately upstream of the unitary dispensing nozzle, so that the pinch valve is opened to allow the minor feed liquid to flow through the unitary dispensing nozzle downstream. When dispensing of the minor feed liquid is completed, the remotely mounted pneumatic solenoid is triggered to close the pinch valve and to cause the 3-way ceramic valve to rotate back 90 degrees to its original starting position. Correspondingly, the fluid communication between the fluid dosing chamber  533  and the fluid outlet  535  is cut off, and flow of the minor feed liquid is completely cut off. 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
     Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.