Patent Application
20230358582
Many commercial applications utilize spray nozzles to deposit material to be sprayed onto target objects and surfaces. Typically, a flow rate of sprayed material depends on the application and the type of material sprayed, and in some applications such as painting, coating and the like the amount of material sprayed onto the target object must be closely controlled.
In the past, various methods and devices have been proposed to measure the material provided through a spray nozzle. For example, one previously proposed solution involves measuring flow rate through a conduit providing the fluid or another material to a sprayer. Other solutions involve using a container having a known volume to collect fluid in a timed fashion.
A first embodiment of the present disclosure provides a portable first container (e.g. tube) that collects flow and measures instantaneous incoming flow rate into the tube. It includes capacitive electrodes, affixed to the tube wall and extending along a major dimension, for example, a vertical direction of the tube along the length of the tube. Each capacitive electrode has an electrical property that corresponds to the localized presence or absence of material across the tube wall. The capacitive electrodes continuously transmit the electrical properties to a controller. The controller is programmed and operates to receive these properties, continuously interpret the amount of liquid present in the tube, calculate the instantaneous rate of change of the amount of liquid present in the tube, and communicate this instantaneous rate of change of the amount of liquid present in the tube to an output.
In an embodiment, multiple arrays of the capacitive electrodes are included and associated with a controller receiving electrical properties from each array. The capacitive electrodes within each array are arranged around and conform to the shape of an outer periphery of the tube wall such that measurements can be averaged to provide a true indication of the level of material in the tube even in conditions when the tube is not perfectly vertically positioned. Alternatively, in an embodiment, the device further includes a tilt metering device such as an electronic gyroscope. The controller receives this signal from the electronic gyroscope corresponding to this direction of gravity and is able to determine and account for tilt based upon this signal.
The capacitive electrodes may be externally affixed to the external surface of the tube wall such that the capacitive electrodes make no contact with the liquid accumulating in the tube, and can also be embedded in at least some of the tube wall. The electrodes are arranged to conform to the shape of the tube wall or other container such that their capacitive measurement is made to be more precise.
In an embodiment, a physical encumbrance to direct flow such as a funnel, or to smooth flow such as a sponge, or both, can be positioned at the open end of the tube, configured such that the fluid entering the tube does not run down the tube walls where the capacitive electrodes are positioned, interfering with the capacitive electrodes' detection of liquid.
In one embodiment, the flow-directing may be accomplished by other structures such as a tube extending along the container internally to receive flow at one end and deposit the flow at another end.
The device in accordance with the disclosure advantageously can be configured to measure conductive or non-conductive materials and fluids, aqueous or non-aqueous solutions, mixtures of different liquids, suspensions of solids in liquids, liquids containing entrained air or a gas, and the like. The devices can be reusable in whole or in part, or single use devices for materials that may permanently attach to the tube.
A second aspect of the present disclosure comprises a method of measuring flow rate. The method comprises various steps including capturing all of the flow deposited by a spray nozzle over a period of time within an internal cavity of a portable first container, such that the flow accumulates within the container during the period where flow is captured; detecting the amount of liquid from the flow with capacitive electrodes, each having an electrical property changing in response to the presence of a liquid in the internal cavity; each transmitting a signal corresponding to this electrical property to a controller, wherein the controller is programmed and operates to receive the signals, interpret the signals simultaneously with the receipt of the signals, or in real time, to determine the amount of liquid present in the internal cavity, calculating the instantaneous rate of change of the amount of liquid present in the internal cavity, and provide the calculated instantaneous rate of change of the amount of liquid present in the internal cavity to an output.
In one embodiment, capacitive electrode material can extend continuously along the height of the container such that a controller can continuously sense the level of fluid or other material as it collects in the container, and estimate or otherwise calculate a rate of collection of the fluid or material within the container. In another embodiment, discrete capacitive sensing areas can be placed along the height of the container, in a non-continuous fashion, to provide signals when the fluid or material collecting in the measurement container reaches those areas. With this information, and also a known or predefined spatial relation of the discrete sensing areas on the container, the controller can receive start/stop signals and calculate the rate of collection of the fluid or other material within the collection container. Additional sensing areas can also be used for ambient temperature and fluid/material property calibration such as capacitance, viscosity and the like, whether continuous sensing or discrete sensing areas are used on the collection container.
An outline view of an exemplary embodiment for a flowmeter 100 is shown in
Capacitive electrodes 17 are attached along the side of the tube 1 on an outer surface 5 of the tube 1. It is contemplated that the electrodes 17, in any of the disclosed embodiments herein, can alternatively be attached on an inner surface of the tube 1, or even embedded within the wall thickness of the tube 1 such that they do not physically come into contact with the air outside of the tube or any fluids or material that may be deposited within the interior of the tube. In the illustrated embodiment, and regardless of the positioning of the electrodes relative to the tube 1, the electrodes 17 extend along a major dimension of the tube, for example, vertically, along a centerline CL of the tube 1 from an area adjacent the open end 3 to an area adjacent the closed end or base 7 of the tube 1, and conform to the shape of the outer surface of the container 1. In the embodiment shown, three electrodes 17 are attached symmetrically around a periphery of the outer surface 5 of the tube 1, but it is contemplated that as few as one electrode, two, or more than three electrodes can be used. Moreover, when more than one electrode 17 is used, their arrangement on the outer surface of the container 1 need not be symmetrical and can be asymmetrical around the periphery and/or along the height of the container.
Each electrode 17 is a capacitive electrode that includes at least an electrically conductive portion coupled with a dielectric layer. The capacitive electrodes can be configured as surface capacitance sensors or projected capacitance sensors, as those technologies are currently known and understood. To improve sensing accuracy and sensor resolution, each electrode 17 may include two or more graduations or sensing elements or areas 9 that are arranged in a one-dimensional or two-dimensional configuration along the dielectric layer, which dielectric layer conforms to the surface of the container. Each electrode 17 and, as shown in the embodiment illustrated in
As the level 2 of material within tube 1 increases, the overall capacitance of each electrode 17 will change depending on the size, position and arrangement of sensing elements or areas 9 along each electrode 17 and their position on the outer surface of the container 1. The changing capacitance sensed by the sensing elements as the container fills can thus provide a respective electrode signal(s) from the electrode(s) 17 that also changes and that is indicative, for example, proportional, of the level 2 of material within the tube 1. The signal provided by the electrodes will also be indicative of the actual level of material in the tube 1, such that a timed monitoring of the signal will provide information indicative of the instantaneous level 2 of material in the tube 1, and also information indicative of the rate of change of material within the tube or, stated differently, the rate at which the tube 1 is filling with material. The signal(s) from the electrodes 17 are provided to a controller 14 which receives and monitors the signals, as shown in the block diagram of
The arrangement of electrodes 17 on and around the tube 1 can be selected to improve measurement accuracy. For example, as shown in
A block diagram for a controller 200 is shown in
The controller 14 may further include additional structures that are known for use with such devices such as a permanent memory, a volatile memory, and processor, transceiver circuits and the like. In the embodiment shown, the controller 200 further includes a power supply or battery 13 for powering the controller 14, a button or switch 12, which may be used to activate the controller 200 and/or initiate and terminate measurement processes, and an output or display 15, which may be used to indicate the values calculated by the controller 14. The output 15 may be a local display on the flowmeter 100 and may also include remote connectivity for transmitting the information to another device such as a cellphone or plant controller using an appropriate wireless and/or wired communication protocol. Additional sensors 204 may also be used, for example, temperature and pressure sensors, which provide environmental information to the controller 14 and also material-specific information about the material being collected in the flowmeter, for example, temperature, which together with predefined information present in the controller's memory about the particular material to be measured such as material density, viscosity etc. can be used to perform corrections to the volume and flowrate values calculated by the controller. The additional sensors 204 may also include a gravity sensor, which provides an indication to the controller of any inclination of the device for use in correcting the various electrode sensor readings.
The controller can calculate volume based on the level of material in the flowmeter, expressed as a height, multiplied by a cross-sectional area of the flowmeter container (tube 1) at any given height, which is a known parameter that depends on the shape of the flowmeter container. In the embodiment shown in
Some exemplary, alternative arrangements for electrodes 17 are shown in
The technology disclosed is such that physical contact by the capacitive electrodes 17 with the liquid 2 is unnecessary. The capacitive electrodes 17 will typically be externally affixed to the tube walls, by means such as fastening, gluing, crimping, etc. or embedded into a substrate 8 that is similarly affixed to the outside of the tube 1. However, some implementations may embed the capacitive electrodes 17 within at least some of the tube wall 2. The substrate 8 can be made of a dielectric material to minimize interference with the capacitive electrodes 17 and may be rigid or flexible. The capacitive electrodes 17 can alternatively be embedded in the tube wall 1 or printed onto the side of the tube 1, or utilize some similarly appropriate method, especially in light of advancing technologies in the application of capacitive electrodes 17, including but not limited to 3D printing.
As can be appreciated, the shape of the collector for the material can affect the accuracy of the measurement. For example, a single electrode placed along one side of a tubular collector can advantageously measure the level of a fluid collected in the tube provided that the fluid enters the tubular collector in a stream that does not flow over the area of the sensor, which may hide or distort a proper reading of the fluid level while the tube is filling. To mitigate such possible conditions, flow directing devices may be used such as shown, for example, in
Moreover, the tube 1 may be formed by a thickness of material that forms the walls of the tube selected based on the type of fluid being measured and the size of the tube so as not to distort any electrode readings. For example, a common example of the arrangement would place measurement electrodes at a distance of twice the wall thickness from reference electrodes. The material of said tube's wall 1 is generally a dielectric material to similarly enhance the capacitive electrodes' reactivity with the liquid 2 across the tube wall 1.
An alternative embodiment for the flowmeter 100 is shown in
In yet another alternative embodiment, a flow directing channel or chute 22 may be disposed within the tube 1 to centrally direct the flow into the tube 1, as shown in
In one embodiment, the capacitive electrodes 17 are shielded from external forces or physical wear or damage by a shield assembly 23, as shown in
An implementation of the disclosure's capacitive electrodes can be designed in such a way as to register the presence or absence of aqueous and non-aqueous solutions, fluid and non-fluid flows, and mixes of air and liquid 2. Non-fluid flows 19 will include powders and similarly solid but non-rigid materials capable of being poured or sprayed 19.
An alternative embodiment for a flowmeter 300 is shown in
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
