Not Applicable.
Many industries need to produce accurate blends of two or more liquids. It is often important that a minimal amount of liquid be wasted or left behind as residue in the blending system. These concerns are increased in the preparation of agrochemicals such as fertilizers and pesticides, as the waste produced from the cleaning out the residual liquid needs to be disposed in accordance with strict regulations.
The present invention is directed to an apparatus that satisfies the need to produce an accurate blend of product at high flow rates and produces minimal residual waste. The apparatus comprises two or more liquid sources. A fluid pump, flow meter, and liquid flow regulator are connected to each liquid source. The liquid sources are combined at a fluid manifold. The fluid manifold is connected to a static mixer, where the various liquids are blended together. The fluid manifold is connected to a delivery coupling, for dispensing the blended liquid into a receptacle. A control system 100 is electrically coupled to the flow meters and liquid flow regulators. The control system 100 is configured to receive an electrical signal generated by each flow meter. The control system 100 is also configured to generate an electric control signal to control the respective flow regulators in response to a recipe.
This disclosed automated liquid blend system produces accurately blended product at high flow rates with minimal amounts of waste product. The automated liquid blend system disclosed utilizes flow regulators to control the rate of liquid flow near the point of delivery, which allows the system to rapidly react to changes in liquid flow. The system is also capable of simultaneously delivering individual liquids at full speed into a mixing point, thereby reducing the processing time. Another advantage of the current disclosure is the elimination of a separate mixing tank, which saves time, expense, and waste.
The use of flow regulators—such as pneumatically or electronically controlled proportional valves—allows for the rate control device to be placed near the point of mixing and delivery. This is advantageous over the use of variable rate pumps, since variable rate pumps generally need to be located nearer the liquid source.
This innovation simultaneously delivers and blends multiple liquids into a single stream. This is advantageous over existing liquid blend systems that bring in individual liquids at full speed into a single mixing vessel. Such systems utilize blending methods that typically require 20 minutes or more to process a 260 gallon shuttle of blended product. This innovation simultaneously delivers the required individual ingredient liquids while mixing and delivering the blended product directly into the final product shuttle. One embodiment of this system and method was able to process a 260 gallon shuttle in only 7 minutes.
Another advantage of the current innovation is removing the requirement for separate mixing tank. Eliminating a separate mixing tank saves time and expense. Removing the mixing tank also eliminates the time and expense of flushing the separate mixing tank. The residual product in a separate mixing tank is substantially more than the residual product in the liquid connections from the manifold to the delivery shuttle in the innovation described here.
This innovation could be implemented in a variety of technology fields that blend liquids according to specific recipes. This innovation is specifically useful to create a liquid blend from a recipe that utilizes liquid sources having different viscosities. This innovation is also specifically useful when one or more of the blended liquids contains a controlled or hazardous substance, such as a pesticide, herbicide, or fertilizer.
It is understood that other embodiments will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments are shown and described by way of illustration only. As will be realized, the concepts are capable of other and different embodiments and their several details are capable of modification in various other respects, all without departing from the spirit and scope of what is claimed as the invention.
Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Aspects are illustrated by way of example, and not by way of limitation, in the accompanying drawings, wherein:
As noted above, this automated liquid blending system overcomes numerous problems, such as low flow rates and residual waste of the blended product.
We disclose a system that has a plurality of liquid sources 10. The liquid sources can contain solutions of individual active ingredients or solutions with a predetermined mix of ingredients. Each liquid source 10 has a fluid connection for connecting the fluid source to a pump. For example, the liquid source 10 can have a connection such as a MicroMatic keg valve or camlock fitting.
In one embodiment, such as the liquid blending system shown in
A pump 20 is in fluid communication with each liquid source. The pump is preferably an air operated, double diaphragm pump. The double diaphragm air pump is advantageous because it can hold a constant pressure on the fluid line without compromising the pump. As liquid pressure builds, the pump slows down until the liquid pressure drops. The pump remains energized and the fluid remains pressurized. The pump can maintain a potential liquid flow rate without negatively affecting pump.
The pump must have sufficient pressure capabilities to satisfy the plumbing requirements of the system. The pressure requirements are based on the plumbing arrangement. The pressure drops through tubing, check valves, and across the static mixer.
A flow meter 30 is in fluid communication with each liquid source. The flow meter 30 could be a volumetric flow meter or a mass flow meter. An example of a volumetric flow meter is a magnetic flow meter. Volumetric flow meters must be calibrated for each product that is put through it. The flow meter 30 provides an individual flow rate signal corresponding to the flow rate for each product. The control system 100 is configured to receive each individual flow rate signal.
The flow meter 30 generates a flow rate signal for each liquid source product. In one embodiment, the flow meter 30 generates an analog electric signal corresponding to the flow rate for each product. The flow meter 30 is in electric communication with the control system 100.
In one embodiment, the flow meter 30 is a mass flow meter. The use of mass flow meters to determine the flow rate of a liquid are known in the art. The mass flow meter would be advantageous to eliminate the calibration step for the volumetric flow meter. In one embodiment, the meter used to generate the flow signal is a mass meter—such as a scale with a load cell—that receives the fluid source container. The mass meter generates a mass signal. The control system 100 is configured to calculate a flow rate based on a loss-in-weight calculation of the change in mass signal over a time interval.
A liquid flow regulator 40 is in fluid communication with each liquid source. The liquid flow regulator provides control over the flow rate of the product. In one embodiment, the control system 100 sends an analog control signal that is received by the liquid flow regulator 40. The liquid flow regulator responds proportionately. For example, the liquid flow regulator can comprise an electro-pneumatic valve, which converts analog electric signal to pneumatic control over the valve, thereby affecting the flow rate. The liquid flow regulator 40 is positioned downstream from flow meter 30 because the regulator causes the flow of the liquid to be turbulent.
In one embodiment, the liquid flow regulator 40 is comprised of teflon to increase compatibility with a variety of products.
The liquid blending system can be described as having respective fluid handling assemblies for each fluid sources containing agrochemicals. Each fluid handling assembly comprises a static-rate pump for each fluid source. Each fluid handling assembly has an inlet fluid connection for connecting to a respective fluid source and an outlet fluid connection for directing a first pressurized fluid. Each fluid handling assembly comprises a meter that generates a fluid signal in relation to the amount of the fluid flowing from the fluid source. Each fluid handling assembly also comprises a proportional valve fluidly connected downstream of the meter, the proportional valve biased in a closed position.
Each proportional valve receives the respective control signal; and each proportional valve opens in response to the respective control signal whereby a desired flow rate of each fluid is continuously delivered to a downstream mixing assembly.
A liquid manifold 70 is in fluid communication with each liquid source. The liquid manifold 70 is a chamber for receiving multiple liquid source connections. For example, the liquid manifold 70 could be an aluminum manifold with multiple ports. The function of the liquid manifold 70 is to combine the multiple fluid sources into a single output. The liquid manifold 70 has a plurality of inlet ports to allow connections from a plurality of liquid sources.
Preferably, the liquid manifold 70 is oriented vertically, with output flow out the top. In making the fluid connections between the liquid sources and the manifold, the higher rate sources are connected into bottom, lower rate product in through the top. In other words, the higher rate liquid connections are located furthest from the discharge point and the lower rate liquid connections are located closer to the discharge point. This allows the higher rate liquid product flow to carry the lower rate liquid through the liquid manifold 70.
A one-way check valve 60 is in fluid communication with each liquid source. Preferably, the check valves 60 are connected immediately before the liquid source is connected to the manifold 70. The check valves 60 prevent liquid back-flow. This allows the system to avoid cross contamination from one recipe to another. In a preferred embodiment, the check valves 60 are self-sealing, non-reactant and not dependent on gravity, mounting position, or reverse flow.
A mixing assembly having a static mixer 80 is in fluid communication with the liquid manifold 70. The static mixer 80 can be an inline static mixer which creates a mixing action as the liquid moves through the static mixer. The static mixers incorporate a turbulence-inducing mixing element in the liquid flow path. These turbulence-inducing mixing elements can have specific shapes and sizes—such as a blade, helix, or wafer—to efficiently cause the liquids to blend. The specific design of the static mixer would depend on the characteristics of the liquids to be blended in a specific application.
In a preferred embodiment, the static mixer 80 is oriented vertically. Liquid flows up through the static mixer. The vertical orientation is advantageous because the liquid flow can vary. It is important that the liquid does not merely trickle through the static mixer. The vertical orientation—with liquid entering through the bottom—assures that liquid only progresses through the static mixer 80 when the volume of the static mixer is full of liquid. This is especially important when the fluid sources have different characteristics, such as differing solubility or viscosity characteristics which could result in the various liquids layering. Passing through the static mixer 80 allows even stiff, gel-like fluids to be broken apart and blended with other fluids.
A shutoff valve 90 is in fluid communication with the blended liquid source upstream of the discharge point. The shutoff valve 90 can be pneumatic powered. The shutoff valve 90 can be electrically connected to Control system 100, allowing the system to control the operation of the shutoff valve 90. Preferably, the shutoff valve 90 can be operated by activating the E-stop.
A delivery coupling is in fluid communication with the blended liquid source at the discharge point. The delivery coupling allows a fluid connection to the delivery vessel. The coupling can have a connection such as a micromatic coupler or cam lock fitting.
An air purge valve 210 is connected to the liquid manifold 70. The air purge valve 210 can be opened to provide a flow of compressed air from a compressed air source 212 to purge residual fluid at the end of the blending delivery cycle. Substantially all liquid product needs to be removed from the manifold and downstream of the manifold. The air purge forces liquid through liquid connections into the shuttle. This provides the customer with a complete delivery of product and also provides an initial cleaning of the blended product. The air purge provides a medium that naturally separates from the blended liquid product. The control system 100 can be programmed to automatically trigger the air purge at the end of blending delivery cycle.
A solvent purge valve 220 is also connected to the liquid manifold 70. The solvent purge valve 220 can be opened to provide a flow of pressurized solvent from a pressurized solvent source 222 to purge residual fluid at the end of the blending delivery cycle and after the air purge. The solvent purge flushes residual fluid from the system. Generally, this waste solvent mixture must be collected and disposed of. The air purge step minimizes the amount of solvent necessary to clear the system of residual liquid. In one embodiment, the solvent used is water. The control system 100 can be programmed to automatically trigger the solvent purge at the end of blending delivery cycle and after the air purge.
The blended liquid is delivered into a delivery shuttle 400. The delivery shuttle 400 is a liquid container that receives the blended liquid. In one embodiment, the delivery shuttle 400 is a one-time use receptacle. The delivery shuttle 400 can be sized as appropriate for the quantity of liquid desired by the customer. In one embodiment, the delivery shuttle is a 260-gallon container. In another embodiment, the delivery shuttle 400 can be a standard 5-gallon bucket. In one embodiment, the delivery shuttle 400 is positioned on a scale 410 for measuring the mass of blended liquid delivered into the delivery shuttle 400.
As shown in
Advantages of the current disclosure include:
In one embodiment, a liquid control center provides a structure 500 for mounting certain of the components of the liquid blend system that are controlled by the control system 100. For example,
As shown in
The modular system is designed to accommodate multiple liquid sources, in some embodiments of the modular system there are between 6 to 20 liquid sources. Certain figures illustrate a second set of equipment for a second liquid source. The respective elements are labeled as follows: a second static-rate pump 120, a second fluid meter 130, a second proportional valve 140; a second check valve 160; a second liquid manifold 170; a second static mixer 180; second air purge valve 212; a second water valve 222; a second shutoff valve 190. Optionally, a divert valve 50 can be in fluid communication with each liquid source. The divert valve 50 can provide isolation between two different liquid paths to isolate certain products from the liquid path for other products. A third check valve 62 is disposed between the outflow of the divert valve and the first manifold 70. The divert valve can provide certain liquid sources to blend into otherwise isolated fluid paths.
Optionally, the system is optimized to increase the continuous production of the blended fluid. The control system 100 continuously tunes the flow-rate for each respective proportional valve to coordinate the completion of the each component liquid at the same time. The control system is configured to store the measured flow rate for specific fluid sources under actual flow conditions in accordance with a range of control signals. During a subsequent control cycle, the control system compares the flow rate of a selected blend recipe with the stored flow rates and selects the control signal that corresponds closest to the flow rate of the selected blend recipe. This tuning process can also occur during a cycle. For example, the control system 100 calculates that 50% of Fluid #1 has been dispersed and 45% of Fluid #2 has been dispersed. The control system 100 may be configured to record the measured flow rate for each fluid source that corresponds with the control signal. The control system 100 may be configured to decrease the flow rate of Fluid #1 by decreasing the respective control signal. The control system 100 may access the stored flow rate and control signal database, to select the control signal that corresponds closest to the flow rate of the selected blend recipe.
It is possible to implement the current disclosure into industries including seed treatment; fertilizer preparation; crop care. In one embodiment, we disclose an automated system for blending fluid comprising:
As shown in
In another embodiment, we disclose an automated system for blending liquids comprising:
It is understood that other embodiments will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments are shown and described by way of illustration only. As will be realized, the concepts are capable of other and different embodiments and their several details are capable of modification in various other respects, all without departing from the spirit and scope of what is claimed as the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
This application claims the benefit of U.S. Provisional Application No. 62/275,327, filed 6 Jan. 2016.
Number | Date | Country | |
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62275327 | Jan 2016 | US |