Abstract:
A chemical dispensing assembly having injector assemblies that combine a solvent stream with a concentrate stream within a Venturi injector assembly to produce a chemical solution outlet stream. Each injector assembly has an interchangeable metering assembly that limits the flow of concentrate into the Venturi injector assembly to change the resulting concentration of the concentrate within the solution outlet stream. The chemical dispensing assembly also has a keyed connector system that prevents the connection of the wrong concentrate container to the wrong injector assembly.

Description:
RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Application No. 61/593,118 entitled CHEMICAL DISPENSING APPARATUS AND RELATED METHODS and filed Jan. 31, 2012, which is incorporated herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to a chemical dispensing apparatus and related methods of mixing chemical solutions from concentrates and dispensing the mixed chemical solutions. Specifically, the present invention is directed to a chemical dispensing apparatus capable of sequentially mixing a plurality of chemical solutions from different concentrates and dispensing the mixed solutions through a single conduit or shared conduits. 
     BACKGROUND OF THE INVENTION 
     Many chemical systems create a plurality of chemical solutions by mixing various concentrates with a solvent stream, typically water, before dispensing the mixed chemical solutions from the chemical system. The chemical solutions are often mixed sequentially such that each chemical solution can be individually fed into a shared outlet for use. Specifically, the systems often provide a continuous solvent stream to which the concentrates are sequentially added to create a plurality of segments in the solvent stream that comprise the desired chemical solutions. Alternatively, a slug of solvent is combined with a slug of concentrate to form a quantity of solution that is fed into the outlet. The sequential mixing of the chemical solutions allow a single system to provide a plurality of different chemical solutions from concentrates that are incompatible or would be less effective if combined into a single chemical solution. Similarly, the sequential mixing can allow certain chemical solutions to be applied in specific sequences providing additional advantages. A common application for the sequential systems is automated car washes and other cleaning systems in which cleaning, rising, and protective chemical solutions are applied sequentially to a vehicle or object to be cleaned. 
     A primary consideration for the mixing systems is efficiently mixing each of the chemical solutions such that chemical solution can be quickly mixed and dispensed through the common outlet before the next chemical solution is prepared. Typically, a diaphragm or similar valve draws a slug of fluid from the concentrate container and combines the concentrate slug with a solvent stream or a solvent slug to create a chemical solution stream. When a solvent stream is provided, the diaphragm valve is often operated to draw a series of slugs to provide a continuous solution stream. In this configuration, an inherent challenge is mixing the slug flow of the concentrate stream with the continuous solvent stream such that the concentrate is evenly distributed throughout the solvent stream at the appropriate concentration. Similarly, selecting the appropriate slug size and frequency to create the appropriately concentrated solution stream can be particularly challenging and be varied depending on the type of concentrate. With slug solvent flow, creating the appropriate sized solvent slug for the corresponding concentrate slug can be particularly challenging. An additional challenge is that the non-continuous slug flow can place greater strain on the valves and other systems than a continuous flow system. 
     A common consideration for the mixing systems is resupplying the mixing system when one or more of the concentrates is exhausted. The mixing systems often comprise a plurality of interface assemblies each connectable to an individual concentrate supply container to draw concentrate from the supply container. The mixing systems are often automated to draw the predetermined amounts of concentrate from the connected concentrate supply container at pre-programmed times or if the controller determines that the specific chemical solution is required. However, if the incorrect concentrate container is connected to the interface the wrong concentrate will be combined with the solvent stream resulting in the incorrect chemical solution being created. The systems often use many different concentrates with equally many different interfaces making connecting the correct concentrate container difficult. In addition, many concentrates can have similar names and appearances further increasing the challenge for operators to correctly replace the concentrate containers. 
     Although mixing systems capable of providing a plurality of different chemical solutions individually provide numerous advantages, a number of challenges still remain regarding the efficient and accurate mixing of the chemical solutions as well as an accurate means of resupplying the system with additional concentrate. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a chemical dispensing assembly comprising a dispensing manifold further comprising at least one injector assembly for combining a solvent stream with a concentrate stream drawn from a concentrate container to form a chemical solution stream. Each injector assembly comprises a secondary line extending between a motive fluid inlet and a common outlet assembly and further comprising a Venturi injector assembly through which the solvent stream is directed to create a vacuum at the necked portion of the Venturi injector assembly. A concentrate tube connected to the concentrate container at one end and fluidly connected to the necked portion of the Venturi injector assembly at the other end allows the vacuum created by the flow of the solvent stream through the necked portion to draw concentrate from the concentrate container into Venturi injector assembly and combine the concentrate stream with the solvent stream. The amount of concentrate drawn is directly proportional to the flow rate of solvent through the Venturi injector assembly providing an accurate and consistent means of mixing the chemical solution at the correct concentration. 
     In certain aspects of the present invention, the concentrate tube can further comprise a metering assembly positioned at the end of the concentrate tube engaged to the Venturi injector assembly. The metering assembly can further comprise a restrictor plug that reduces the cross-sectional area of the concentrate tube limiting the flow of concentrate drawn through the concentrate tube by the vacuum created by the flow of the solvent stream through the venture injector assembly. In one aspect, the restrictor plug can further comprise a channel sized to defining an opening through which concentrate can be drawn by the vacuum. The number of turns, the diameter of the channel, the angle of the channel and other channel characteristics and dimensions can be varied to change the flow of concentrate around the restrictor plug. In certain aspects, the restrictor plug can be interchanged with restrictor plugs in which the channels have different characteristics to provide a different concentrate flow rate thereby regulating the concentration of the resulting chemical solution. In one aspect, the metering assembly can further comprise a one-way valve allowing fluid to be fed into the Venturi injector assembly from the concentrate container, but preventing backflow of fluid from the Venturi injector assembly. 
     In certain aspects of the present invention, the chemical dispensing assembly can further comprise a locking assembly for securing the concentrate container to the concentrate tube. The locking assembly further comprises an engagement head to which the end of concentrate tube opposite the metering assembly is attached. The engagement head is movable between an engaged position in which the end of the concentrate tube is fluidly connected to the opening of the concentrate container and a disengaged position in which the concentrate tube is disconnected from the concentrate container. In one aspect, the locking assembly can further comprise a one-way valve allowing fluid to be drawn from the concentrate container, but preventing backflow of fluid into the concentrate container. In one aspect, the chemical dispensing assembly can further comprise a container support shelf for supporting the concentrate container. In this configuration, the container support shelf can comprise an alignment element engagable to the concentrate container to position the concentrate container such that the container opening is aligned with the engagement head for fluidly connecting the concentrate tube with the concentrate container when the engagement head is moved into the engaged position. 
     In one aspect, the concentrate container further comprises a container insert having a keyed connector operably linked to a concentrate tube. The keyed connector is positioned at the opening of the concentrate container. In this configuration, the engagement head further comprises a corresponding connector interfacing with the keyed connector to link the concentrate tube to the concentrate tube when the engagement head is positioned in the engaged position. Each keyed connector comprises at least one tab interfacing with at least one tab of the corresponding connector, wherein the arraignment, positioning and/or size of the tabs are varied to prevent connection of keyed connector with non-corresponding connectors. The keyed connectors prevent attachment of the wrong concentrate containers to the injector assembly. In one aspect, the concentrate tube can further comprise a screen or filter to prevent solids, participated crystals or other particulates from entering the concentrate tube and being drawn into the injector assembly. 
     In another aspect, a chemical dispensing assembly, according to an embodiment of the present invention, can comprise a motive fluid inlet, an outlet assembly, at least one concentrate container and at least one injector assembly comprising a secondary line linking the motive fluid inlet to the outlet assembly. The injector assembly further comprises a concentrate tube and a Venturi injector assembly having a necked portion. In operation, the concentrate tube fluidly connects the necked portion of the Venturi injector assembly with the concentrate container, wherein feeding a solvent stream from the motive fluid inlet through the Venturi injector assembly creates a vacuum in the necked portion drawing concentrate from the concentrate container and combining the concentrate stream with the solvent stream. In certain embodiments, the concentrate tube can further comprise a metering assembly having an interchangeable restrictor plug constricting the flow of concentrate through the concentrate tube to change the resulting concentration of the mixed chemical solution. In certain embodiments, the injector assembly can further comprise an engagement head movable to fluidly connect and disconnect the end of the concentrate tube with the concentrate container. In this configuration, the container can further comprise an insert positioned in the opening of the container and comprising a keyed connector preventing fluid connection of the concentrate tube with the container when the wrong container is used. 
     In yet another aspect, a method of formulating a chemical solution comprising drawing a solvent stream from a motive fluid inlet and directing the solvent stream through a Venturi injector assembly such that the solvent stream enters a necked portion of the Venturi injector assembly creating a vacuum at the necked portion. The method further comprises fluidly connecting the necked portion of the Venturi injector assembly and a concentrate container with a concentrate tube to draw a concentrate stream from the concentrate container with the vacuum created in the necked portion. The method also comprises a positioning a first restrictor plug within the concentrate tube comprising a first channel having a first cross-sectional area smaller than the cross-sectional area of the concentrate tube to reduce the effective cross-sectional area of the tube limiting the flow of the concentrate stream through the concentrate tube. The method further comprises exchanging the first restrictor plug with a second restrictor plug comprising a second channel having a second cross-sectional area different from the first cross-sectional area of the first channel. 
     The above summary of the various representative embodiments of the invention is not intended to describe each illustrated embodiment or every implementation of the invention. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the invention. The figures in the detailed description that follow more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a chemical dispensing assembly according to an embodiment of the present invention. 
         FIG. 2  is a side view of the chemical dispensing assembly depicted in  FIG. 1 . 
         FIG. 3  is a front view of the chemical dispensing assembly depicted in  FIG. 1 . 
         FIG. 4  is a rear view of the chemical dispensing assembly depicted in  FIG. 1 . 
         FIG. 5  is an isolated front view of an injector assembly and a concentrate container according to an embodiment of the present invention. 
         FIG. 6  is a side view of the injector assembly and concentrate container depicted in  FIG. 5 , wherein the concentrate container is fluidly connected to the injector assembly. 
         FIG. 7  is a side view of the injector assembly and concentrate container depicted in  FIG. 5 , wherein the concentrate container is positioned for fluid connection to the injector assembly. 
         FIG. 8  is a side view of the injector assembly and concentrate container depicted in  FIG. 5 , wherein the concentrate container is removed from the chemical dispensing assembly. 
         FIG. 9  is a cross-sectional side view of a locking assembly according to an embodiment, wherein the locking assembly is positioned to fluidly connect an injector assembly with a concentrate container. 
         FIG. 10  is a cross-sectional side view of the locking assembly depicted in  FIG. 5 , wherein the locking assembly is positioned to disconnect the fluid connection between the injector assembly and the concentrate container. 
         FIG. 11  is a cross-sectional side view of an injector assembly according to an embodiment of the present invention. 
         FIG. 12  is an exploded view of an injector assembly according to an embodiment of the present invention. 
         FIG. 13  is an exploded view of metering assembly of the present invention. 
         FIG. 14 a    is a top view of a container insert according to an embodiment of the present invention. 
         FIG. 14 b    is a bottom view of an engagement head according to an embodiment of the present invention. 
         FIG. 15 a    is a top view of a container insert according to an embodiment of the present invention. 
         FIG. 15 b    is a bottom view of an engagement head according to an embodiment of the present invention. 
         FIG. 16 a    is a top view of a container insert according to an embodiment of the present invention. 
         FIG. 16 b    is a bottom view of an engagement head according to an embodiment of the present invention. 
         FIG. 17  is a front view of a concentrate container according to an embodiment of the present invention. 
         FIG. 18  is a side cross-sectional view of a concentrate container having a container insert according to an embodiment of the present invention. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     As depicted in  FIGS. 1-4 and 11 , a chemical dispensing assembly  20 , according to an embodiment of the present invention, comprises a mounting frame  22 , an inlet line  24 , a solution outlet line  26  and a dispensing manifold  27  having at least one injector assembly  28  fluidly connectable to at least one concentrate container  30 . The mounting frame  22  comprises connection points for securing and positioning the inlet line  24 , the solution outlet line  26  and each injector assembly  28 . The inlet line  24  is fluidly connectable to a motive fluid inlet for supplying a quantity of solvent or a solvent stream to the injector assembly  28 . Similarly, the solution outlet line  26  is fluidly connectable to an outlet assembly for receiving and using the mixed chemical solution output from the injector assembly  28 . The injector assembly  28  comprises a secondary line  32  fluidly connecting the inlet line  24  with the solution outlet line  26 . As depicted in  FIGS. 1-4 , a plurality of injector assemblies  28  can be operably linked to a single inlet line  24  and each linked to an individual solution outlet line  26 . In other embodiments, the plurality of injector assemblies  28  can have individual inlet lines  24  and/or a shared solution outlet line  26 . In other embodiments, the chemical dispensing assembly  20  can have a single inlet line  24 , a single injector assembly  28  and a single solution outlet line  26 . 
     As depicted in  FIGS. 1, 3, 5 and 11 , each injector assembly  28  can further comprise an injector assembly  34 , a concentrate supply line  38  and a Venturi injector assembly  40  defining a necked portion  42 . The injector assembly  34  defines the secondary line  32  linking the inlet line  24  with the solution outlet line  26 . The concentrate supply line  38  is fluidly connected to the secondary line  32  at one end through a port  36  in the necked portion  42  of the Venturi injector assembly  40 . The opposite end of the concentrate supply line  38  is fluidly connectable to the concentrate container  30 . In operation, the Venturi injector assembly  40  is positioned in the secondary line  32  such that the solvent stream from the inlet line  24  is directed through the necked portion  42  and undergoes a pressure change to create a vacuum at the necked portion  42 . The vacuum created at the necked portion  42  draws concentrate from the concentrate container  30  to entrain and mix the concentrate within the solvent stream to produce a chemical solution stream or a quantity of chemical solution. 
     As depicted in  FIGS. 11 and 13 , in certain embodiments, the injector assembly  34  can further comprise a port  44  comprising at least one engagement element  46 , such as a protruding tab, engagable with a corresponding engagement element  48  on the solution outlet line  26 . The port  44  can further comprise an o-ring, gasket or other sealing means for preventing leakage at the interface between the port  44  and the solution outlet line  26 . 
     As depicted in  FIG. 11 , in certain embodiments, the injector assembly  28  can further comprise an inlet valve  50  controlling flow of the solvent from the inlet line  24 . As depicted in  FIG. 11 , the inlet valve  50  can comprise a solenoid valve comprising a valve housing  52 , a plunger  54 , a solenoid coil  56  and a spring  58 , wherein the spring  58  biases the plunger  54  to obstruct the secondary line  32  preventing flow of solvent through the secondary line  32  until a current is supplied to the solenoid coil  56  to induce an electromagnetic field retracting the plunger  54 . In other embodiments, the inlet valve  50  can comprise a diaphragm valve and other conventional valve type capable electronic control of the flow of solvent through the secondary line  32 . 
     As depicted in  FIG. 11 , each injector assembly  28  can further comprise a metering assembly  60  comprising a restrictor plug  62  aligned with the concentrate supply line  38  to reduce the effective cross-sectional area of the concentrate supply line  38 . The metering restrictor plug  62  effectively plugs the concentrate supply line  38  and comprises a helical channel  64  defining a restricted flow path past the restrictor plug  62 . In certain embodiments, the helical channel  64  draws concentrate through the helical channel  64  through capillary action assisted by the vacuum created by the necked portion  42  of the Venturi injector assembly  40 . The number of turns, the diameter of the channel  64 , the angle of the turns of the channel  64  and other channel  64  characteristics and dimensions can be varied to change the flow of concentrate through the restrictor plug  62 . In certain embodiments, the restrictor plug  62  can be interchanged with restrictor plugs  62  having different channel characteristics to provide a different concentrate flow rate to alter the resulting concentration of the mixed chemical solution. In certain embodiments, the metering assembly  60  can further comprise a ball valve  66  biased to only allow one-way flow of the concentrate into the necked portion  42  while preventing back flow of the mixed chemical solution into the concentrate supply line  38 . 
     As depicted in  FIG. 11 , in certain embodiments, the metering assembly  60  can comprise a modular arrangement in which the metering assembly  60  can be replaced to install different metering assembly  60  having a restrictor plug  62  having different channel characteristics thereby changing the flow rate of concentrate into the Venturi injector assembly  40 . In this configuration, the injector assembly  34  can further comprise a port  68  comprising at least one engagement element  70 , such as a protruding tab, engagable with a corresponding engagement element  72  on the metering assembly  60 . The port  68  can further comprise an o-ring, gasket or other sealing means for preventing leakage at the interface between the port  68  and the metering assembly  60 . Similarly, the metering assembly  60  can further comprise a port  74  comprising at least one engagement element  76 , such as a protruding tab, engagable with a corresponding engagement element  78  on the concentrate supply line  38 . The port  74  can further comprise an o-ring, gasket or other sealing means for preventing leakage at the interface between the metering assembly  60  and the concentrate supply line  38 . 
     As depicted in  FIGS. 6-10 , in certain embodiments, the chemical dispensing assembly  20  can further comprise a locking assembly  80  for fluidly connecting the concentrate supply line  38  with the concentrate container  30 . The locking assembly  20  further comprises a engagement head  82  for receiving an end of the concentrate supply line  38  and movable in a vertical axis between an engaged position in which the end of the concentrate supply line  38  is fluidly connected with the concentrate container  30  and a disengaged position in which the end of the concentrate supply line  38  is disconnected from the concentrate container  30 . The engagement head  82  further comprises a port  84  fluidly connected to an adapter  86  insertable into a mouth  87  of the concentrate container  30  to fluidly connect the concentrate supply line  38  with the concentrate container  30  when the engagement head  82  is moved into the engaged position. The port  84  further comprises at least one engagement element  88 , such as a protruding tab, engagable with a corresponding engagement element  90  on the concentrate supply line  38  to fluidly connect the concentrate supply line  38  to the adapter  86 . In certain embodiments, the engagement head  82  can further comprise a ball valve  92  biased to only allow one-way flow of the concentrate into the adapter  86  from the concentrate container  30  while preventing back flow of solution or concentrate from the concentrate supply line  38 . 
     As depicted in  FIGS. 6-10 , in certain embodiments, the locking assembly  80  can further comprise a track  94  for aligning the engagement head  82  with the concentrate container  30  and guiding the engagement head  82  as the engagement head  82  moves vertically between the engaged position and the disengaged position. In this configuration, the mounting frame  22  can further comprise a support shelf  96  for receiving and supporting the concentrate container  30  as depicted in  FIGS. 6-8 . The support shelf  96  can further comprise an alignment element  98  engagable to corresponding notch  100  in the concentrate container  30  to align the mouth  87  of the concentrate container  30  with the adapter  86 . 
     As depicted in  FIGS. 6-10 , the locking assembly  80  can further comprise a rotatable handle  102  comprising a non-linear notch  104 . In this configuration, the engagement head  82  further comprises a protrusion  106  receivable within the notch  104 , wherein the notch  104  is oriented and shaped such that rotation of the handle  102  applies a downward or upward force on the engagement head  82  to move the engagement head  82  between the engaged position and the disengaged position. In certain embodiments, the notch  104  is curved to retain resist vertical movement of the engagement head  82  when the adapter  86  is inserted into the mouth  87  of the concentrate container  30  to prevent inadvertent disengagement of the adapter  86  from the concentrate container  30  while concentrate is being drawn from the concentrate container  30 . 
     As depicted in  FIGS. 9-10 and 17-18 , the chemical dispensing assembly  20  can further comprise a container insert  108  insertable into the concentrate container  30 . The container insert  108  further comprises a keyed connector  112  and a concentrate tube  114 . The keyed connector  112  further comprises an overlapping adapter  116  for receiving the adapter  86  of the engagement head  82  when the engagement head  82  is positioned in the engaged position to fluidly connect the concentrate supply line  38  with the concentrate tube  114 . In certain embodiments, the keyed connector  112  further comprises a mouth interface  118  for aligning the overlapping adapter  116  with the center of the mouth  87  of the concentrate container  30  and preventing concentrate from leaking past the overlapping adapter  116  when the engagement head  82  is positioned in the disengaged position or when the concentrate container  30  is being connected to the chemical dispensing assembly  20 . The concentrate tube  114  is sized to extend the length of the concentrate container  30  to draw concentrate from the bottom of the concentrate container  30 . In one aspect, the concentrate tube  114  can further comprise a screen or filter  124  to prevent solids, participated crystals or other particulates from entering the concentrate tube and being drawn into the injector assembly  28 . 
     As depicted in  FIGS. 14-16 , the container insert  108  can further comprise at least one keyed tab  120  positioned proximate to the overlapping adapter  116 . In this configuration, the engagement head  82  can further comprise at least keyed tab  122  paired with the keyed tab  120  of the container insert  108 . Each paired keyed tabs  120 ,  122  are shaped to mirror or misaligned with the corresponding keyed tab  120 ,  122  such that the engagement head  82  can be moved into the engaged position with the mouth  87  of the container  30  without engagement of the keyed tabs  120 ,  122 . If mismatched pair of keyed tabs  120 ,  122  is used, the keyed tabs  120 ,  122  are engaged as the engagement head  82  is moved into the engaged position preventing connection of the adapter  86  with the overlapping adapter  116  thereby preventing fluid connection of the concentrate supply line  38  with the concentrate container  30 . In certain embodiments, the keyed tabs  120 ,  122  can be oriented radially or axially to prevent an incorrect keyed tab  120 ,  122  from moving past the opposing keyed tab  120 ,  122  without engagement. 
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and described in detail. It is understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.