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.
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 cleaning.
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 combining 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.
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.
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:
a is a top view of a container insert according to an embodiment of the present invention.
b is a bottom view of an engagement head according to an embodiment of the present invention.
a is a top view of a container insert according to an embodiment of the present invention.
b is a bottom view of an engagement head according to an embodiment of the present invention.
a is a top view of a container insert according to an embodiment of the present invention.
b is a bottom view of an engagement head 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.
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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.
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.
Number | Date | Country | |
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61593118 | Jan 2012 | US |