Liquid distribution systems and methods for operating liquid distribution systems

Abstract

A liquid distribution system includes a product source configured to contain a product to be distributed; at least one filter in fluid communication with the product source; a rinse liquid source configured to contain a rinse liquid; at least one spray nozzle in fluid communication with the filter and configured to spray the product received from the product tank via the filter; a source valve between the product source and the filter; at least one drain valve in fluid communication with the filter; and a controller. The controller is configured to clean the filter(s) by stopping flow of the product from the product source through the source valve; delivering the rinse liquid from the rinse liquid source to the filter(s); and opening the drain valve(s). Related vehicles and methods are also disclosed.

Description

LIQUID DISTRIBUTION SYSTEMS AND METHODS FOR OPERATING LIQUID DISTRIBUTION SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of U. S. Provisional Patent Application 63 / 665,071, “Liquid Distribution Systems and Methods for Operating Liquid Distribution Systems,” filed June 27, 2024; and U. S. Provisional Patent Application 63 / 722,510, “Liquid Distribution Systems and Methods for Operating Liquid Distribution Systems,” filed November 19, 2024; the entire disclosure of each of which is incorporated herein by reference.FIELD

[0002] Embodiments of the present disclosure relate to mobile machines, such as self-propelled agricultural machines, towed machines, and similar vehicles. More particularly, embodiments relate to mobile machines with a fluid product tank.BACKGROUND

[0003] Filtration of a sprayer liquid system is important in preventing nozzle tip orifice openings from becoming clogged with particulates. Inadequate and absent application could result if an improper filter screen mesh size is utilized and / or solid residuals prevent the mixture from getting to the nozzles. For applicators that utilize suspension type products, proper agitation durations are required for attaining a homogeneous mixture before spraying commences. If the material is not thoroughly agitated beforehand, potential clogging of the strainer screen will decrease the cleaning interval, which causes more down time for the operator. Furthermore, the operator may not know when the filter is clogged. The quality of the liquid application (e.g., uniformity, total amount applied, etc.) can be negatively affected by clogged filters and / or nozzles.

[0004] Current application systems function by delivering product from the product tankthrough a sump valve and pumping and discharging, prior to the filter, the suspension mixture to an agitation proportional valve which is attached to agitation tube(s) or hydraulic stirrer(s). This cycle is performed for a duration of time so that suspension mixture is maintained and dissolved properly. Then upon opening the main delivery shut offvalve, the mixture is filtered before proceeding to the nozzles. Inadequate agitation permits large suspension particles that are not completely dissolved within the product tank to be captured by the filter screen, which may cause build-up of the filter and require more frequent removal of the screen to clean and dislodge the suspension particles, which may result in more down time for the applicator. Furthermore, removing the screen involves contact with the product, which risks contamination to the system and chemical exposure to the operator.

[0005] When an impure water source is used to fill the product tank, additional filtration may be necessary as compared to, for example, filtered culinary water.BRIEF SUMMARY

[0006] In some embodiments, a liquid distribution system includes a product source configured to contain a product to be distributed; at least one filter in fluid communication with the product source; a rinse liquid source configured to contain a rinse liquid; at least one spray nozzle in fluid communication with the filter(s) and configured to spray the product received from the product tank via the filter(s); a source valve between the product source and the filter(s); at least one drain valve in fluid communication with the filter(s); and a controller. The controller is configured to clean the filter(s) by stopping flow of the product from the product source through the source valve; delivering the rinse liquid from the rinse liquid source to the filter(s); and opening the drain valve(s).

[0007] The system may include a waste rinse tank, and the at least one drain valve may be configured to deliver the rinse liquid to the waste rinse tank.

[0008] The product source may include a product tank and / or a main pump. Stopping flow of the product from the product source may include turning off the main pump.

[0009] In certain embodiments, the product source may include a pressurized air source.

[0010] The rinse liquid source may include a rinse liquid tank and / or an auxiliary pump. Delivering the rinse liquid from the rinse liquid source to the filter(s) may include turning on the auxiliary pump.

[0011] In certain embodiments, the rinse liquid source may include a pressurized air source.

[0012] The liquid distribution system may optionally include a spray valve between the filter(s) and the at least one spray nozzle.

[0013] In some liquid distribution systems, delivering the rinse liquid from the rinse liquid source to the at least one filter may include deliverin the rinse liquid from the rinse liquid source though the filter(s) in a direction of flow opposite to a direction of flow from the product source to the spray nozzle(s).

[0014] In other liquid distribution systems, delivering the rinse liquid from the rinse liquid source to the at least one filter includes deliveringthe rinse liquid from the rinse liquid source though the filter(s) in a same direction of flow as a direction of flow from the product source to the spray nozzle(s).

[0015] The liquid distribution system may include a level switch configured to send a signal to the controller indicative of a fluid level in the waste rinse tank, a flow meter configured to send a signal to the controller indicative of an amount of rinse fluid flowing to the waste rinse tank, and / or a quality sensor configured to measure a property of liquid entering the waste rinse tank.

[0016] The liquid distribution system may include a first pressure sensor configured to measure a pressure between the product source and the filter(s) and / or a second pressure sensor configured to measure a pressure between the filter(s) and the spray nozzle(s).

[0017] The liquid distribution system may include a recycle valve. The recycle valve may fluidly connect the at least one drain valve with the source valve when the recycle valve is in an open position.

[0018] The spray nozzle(s) may include a plurality of spray nozzles spaced along a boom.

[0019] The at least one filter may include at least two filters in series, and the system may optionally include an intermediate pressure sensor between the at least two filters.

[0020] The at least one drain valve may include a drain valve corresponding to each filter.

[0021] Some embodiments include an agricultural crop sprayer having the liquid distribution system as described above.

[0022] A method of operating a liquid distribution system includes providing a liquid product from a product source through a source valve, at least one filter, and at least one spray nozzle; terminating flow of the liquid product through the source valve, the filter(s), and the at least one spray nozzle; providing a rinse liquid from a rinse liquid source to the filter(s); opening at least one drain valve in fluid communication with the filter(s) to enable flow from the rinse liquid source through the filter(s) and the drain valve(s); terminating flow of the rinse liquid from the rinse liquid source; and restarting flow of the liquid product from the product source through the source valve, the filter(s), and the spray nozzle(s).

[0023] In some embodiments, opening the drain valve(s) includes opening a first drain valve in fluid communication with a first filter of the at least one filter; closing the first drain valve; and opening a second drain valve in fluid communication with a second filter of the at least one filter.

[0024] In some embodiments, the rinse liquid is provided from the rinse liquid source to the filter(s) in a direction of flow opposite to a direction of flow from the product source to the spray nozzle(s).

[0025] In other embodiments, the rinse liquid is provided from the rinse liquid source to the filter(s) in a same direction of flow as a direction of flow from the product source to the spray nozzle(s).

[0026] The method may include determining a status of the filter(s) based on a signal from at least one pressure sensor.

[0027] The flow of the liquid product through the source valve, the filter(s), and the spray nozzle(s) may be terminated responsive to a preselected status of the filter(s).

[0028] The status of the filter(s) may optionally be displayed on a display.

[0029] The method may include determining a flow rate of the rinse liquid through the drain valve, collectingthe rinse liquid in a waste rinse tank, determining a fill condition of the waste rinse tank, and / or measuring a property of the rinse liquid flowing through the drain valve.

[0030] The method may include recycling the rinse liquid through the at least one filter.

[0031] Within the scope of this application it should be understood that the various aspects, embodiments, examples, and alternatives set out herein, and individual features thereof may be taken independently or in any possible and compatible combination. Where features are described with reference to a single aspect or embodiment, it should be understood that such features are applicable to all aspects and embodiments unless otherwise stated orwhere such features are incompatible.BRIEF DESCRIPTION OF THE DRAWINGS

[0032] While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, various features and advantages may be more readily ascertained from the following description of example embodiments when read in conjunction with the accompanying drawings, in which:

[0033] FIG. 1 illustrates an agricultural vehicle in the form of a self-propelled crop sprayer;

[0034] FIG. 2A is a simplified flow diagram showing liquid flow in a liquid distribution system and out through spray nozzles, such as in the crop sprayer shown in FIG. 1 ;

[0035] FIG. 2B is a simplified flow diagram showing liquid pressure building in the liquid distribution system of FIG. 2A to clean the filter;

[0036] FIG. 2C is a simplified flow diagram showing liquid flowing in the liquid distribution system of FIG. 2A to clean the filter;

[0037] FIG. 3A is a simplified flow diagram showing another liquid distribution system showing liquid flow out through the spray nozzles;

[0038] FIG. 3B is a simplified flow diagram showing liquid pressure building in the liquid distribution system of FIG. 3A to clean the filter;

[0039] FIG. 3C is a simplified flow diagram showing liquid flowing in the liquid distribution system of FIG. 3A to clean the filter;

[0040] FIG. 4A is a simplified flow diagram showing liquid flow in a liquid distribution system and out through spray nozzles, such as in the crop sprayer shown in FIG. 1 ;

[0041] FIG. 4B is a simplified flow diagram showing liquid pressure building in the liquid distribution system of FIG. 4A to clean the filters;

[0042] FIG. 4C is a simplified flow diagram showing liquid flowing in the liquid distribution system of FIG. 4A to clean one filter;

[0043] FIG. 4D is a simplified flow diagram showing liquid flowing in the liquid distribution system of FIG. 4A to clean another filter;

[0044] FIG. 5A is a simplified flow diagram showing another liquid distribution system showing liquid flow out through the spray nozzles;

[0045] FIG. 5B is a simplified flow diagram showing liquid pressure building in the liquid distribution system of FIG. 5A to clean the filter;

[0046] FIG. 5C is a simplified flow diagram showing liquid flowing in a recycle loop in the liquid distribution system of FIG. 5A to clean the filter;

[0047] FIG. 5D is a simplified flow diagram showing liquid draining from the filter in the liquid distribution system of FIG. 5A;

[0048] FIG. 6 is a simplified flow chart illustrating a method of operating a liquid distribution system;

[0049] FIG. 7 illustrates a control module that may be used in conjunction with a liquid distribution system; and

[0050] FIG. 8 illustrates an example computer-readable storage medium comprising processor-executable instructions configured to embody one or more of the methods of operating a liquid distribution system, such as the method illustrated in FIG. 6.DETAILED DESCRIPTION

[0051] The illustrations presented herein are not actual views of any agricultural machine or portion thereof, but are merely idealized representations to describe example embodiments of the present disclosure. Additionally, elements common between figures may retain the same numerical designation.

[0052] The following description provides specific details of embodiments.However, a person of ordinary skill in the art will understand that the embodiments of the disclosure may be practiced without employing many such specific details. Indeed, the embodiments of the disclosure may be practiced in conjunction with conventional techniques employed in the industry. In addition, the description provided below does not include all the elements that form a complete structure or assembly. Onlythose process acts and structures necessary to understand the embodiments of the disclosure are described in detail below. Additional conventional acts and structures may be used. The drawings accompanying the application are for illustrative purposes only, and are thus not drawn to scale.

[0053] As used herein, the terms “comprising,” “including,” “containing,” “characterized by,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps, but also include the more restrictive terms “consisting of” and “consisting essentially of” and grammatical equivalents thereof.

[0054] As used herein, the term “may” with respect to a material, structure, feature, or method act indicates that such is contemplated for use in implementation of an embodiment of the disclosure, and such term is used in preference to the more restrictive term “is” to avoid any implication that other, compatible materials, structures, features, and methods usable in combination therewith should or must be excluded.

[0055] As used herein, the term “configured” refers to a size, shape, material composition, and arrangement of one or more structure and / or apparatus facilitating operation thereof in a predetermined way.

[0056] As used herein, the singular forms following “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0057] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0058] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range.

[0059] FIG. 1 shows a crop sprayer 102 used to deliver chemicals to agricultural crops in a field. The crop sprayer 102 includes a chassis 104 and an operator cab 106 mounted on the chassis 104. The operator cab 106 may house controls forthe crop sprayer 102. An engine 108 may be mounted on a forward portion of the chassis 104 in front of operator cab 106 or may be mounted on a rearward portion of the chassis 104 behind the operator cab 106. The engine 108 may be commercially available from a variety of sources and may include, for example, a diesel engine or a gasoline powered internal combustion engine, a battery-powered electric motor, etc. The engine 108 provides energy to propel the crop sprayer 102 through a field on wheels or tracks, and may also provide energy to spray liquids from the crop sprayer 102.

[0060] The crop sprayer 102 further includes a product tank 110 to store a liquid to be sprayed on the field. The liquid may include chemicals, such as but not limited to, herbicides, pesticides, fungicides, and / or fertilizers. The product tank 110 may be mounted on the chassis 104, either in front of or behind the operator cab 106. The crop sprayer 102 may include more than one product tank 110 to store different chemicals to be sprayed on the field. The stored chemicals may be dispersed by the crop sprayer 102 one at a time, or different chemicals may be mixed and dispersed together in a variety of mixtures.

[0061] A boom 112 on the crop sprayer 102 is used to distribute the liquid from the product tank 110 over a wide swath as the crop sprayer 102 is driven through the field. Theboom 112 may include two or more portions that can fold fortransport on public roadways, and unfold ( / .e., to the position shown in FIG. 1) for field operations.

[0062] FIG. 2A is a simplified flow diagram of a liquid distribution system 200, and showing liquid flow from the product tank 110 to the boom 112.

[0063] The liquid distribution system 200 generally includes a product source 202, which may typically be the product tank 110 shown in FIG. 1 , a rinse liquid source 204, a filter 206, and one or more spray nozzles 208. The liquid from the product source 202 is filtered before reaching the spray nozzles 208. In some embodiments, the product source 202 may include a main pump 210 to move liquid to be applied by the liquid distribution system 200 from the product tank 110 to the spray nozzles 208 (e.g., carried by the boom 112). The product source 202 may optionally include a pressurized air source 212 instead of or in addition to the main pump 210.

[0064] In use, the liquid flows through a source valve 214 and the filter 206 en route to the spray nozzles 208. The source valve 214 is configured to provide liquid from either the product source 202 or a rinse liquid source 204 to the filter 206. The source valve 214 is shown as a T-port valve, but may include any selected valve configuration (including multiple valves). For example, the source valve 214 may include a checkvalve on the flow line from the product source 202, and an on / off valve on the line from the rinse liquid source 204. The source valve 214 may limit or prevent back-flow to the product source 202 when liquid is flowingfrom the rinse liquid source 204, which helps maintain the composition of the liquid in the product source 202 (e.g., to avoid contamination).

[0065] The filter 206 is in fluid communication with the product source 202 via the source valve 214, and is configured to remove some particulate materialfrom the liquid. The filter 206 may include a housing containing one or more mesh screens to separate solid material greater than a preselected size from the liquid. For example, the filter 206 may contain 50-mesh screen, an 80-mesh screen, or any other selected mesh size, depending on the composition of the liquid flowingfrom the product source 202. The screen may be generally cylindrical, and may be oriented at an oblique angle relative to thedirection of flow of the liquid. For example, the filter 206 may be as described in U.S.Patent 11,786,849, “Sprayer Filtering System,” granted October 17, 2023.

[0066] The filter 206 may gradually become clogged, and therefore it may be prudent to clean the filter 206 periodically. To identify when filter cleaning is due, the liquid distribution system 200 may include a first pressure sensor 216 before the filter 206 and / or a second pressure sensor 218 after the filter 206. The pressure sensors 216, 218 may be attached to fittings in the housing of the filter 206, to liquid flow lines before and after the filter 206, or at any other selected location in the liquid distribution system 200. The pressure sensors 216, 218 may communicate with a controller 220. The controller 220 may include or be in communication with a user interface 222, such as a touch-screen display. The controller 220 and / or the user interface 222 may be a computer in the operator cab 106 (FIG. 1) of the crop sprayer 102, a mobile device, etc. The controller 220 and / or user interface 222 may indicate a health of the filter 206 (e.g., an estimation of the amount of time remaining before the flow rate drops below a predefined threshold, a percentage remaining of the total liquid that can be filtered before the flow rate drops belowthe predefined threshold, a percentage clogged, etc.).

[0067] The filter 206 may periodically be cleaned to help ensure the spray nozzles 208 can effectively deliver the product. The cleaning may be performed in two parts, generally illustrated in FIG. 2B and FIG. 2C. First, pressure at the filter 206 is raised (FIG. 2B), followed by flushing of particulate material from the filter 206 (FIG. 2C). Generally, a higher pressure may help to dislodge particulate material. That higher pressure may not be desirable for a spray operation (FIG. 2A). In some embodiments, however, the pressurebuilding phase may be omitted.

[0068] The rinse liquid source 204 is configured to provide a rinse liquid to clean the filter 206. The rinse liquid source 204 may include a rinse liquid tank 224 and an auxiliary pump 226, as shown, but may alternatively use the pressurized air source 212 to drive liquid and build pressure instead of or in addition to the auxiliary pump 226.

[0069] FIG. 2B and FIG. 2C together illustrate how the rinse liquid source 204 is used to clean the filter 206. In FIG. 2B, the controller 220 may send signals to stop flow ofliquid from the product source 202 (e.g., by turning off the main pump 210) and start flow of rinse liquid from the rinse liquid source 204 (e.g., by switching the source valve 214 to provide rinse liquid from the rinse liquid source 204 instead of product from the product source 202). In FIG. 2C, the controller 220 may also send signals to enable the rinse liquid to be drained from the filter 206 (e.g., by opening a drain valve 228 between the filter 206 and a waste rinse tank 230). The rinse liquid source 204 may then deliver the rinse liquid (fresh water, filtered recycled water, a cleaning composition including a surfactant, a solvent, etc.) to the filter 206 to clean the filter 206. The rinse liquid may pass through the filter in a direction that carries solid material out of the filter 206 to the waste rinse tank 230. For example, if the filter 206 includes a cylindrical screen, as depicted in FIG. 2A and in U.S. Patent 11 ,786,849, referenced above, the rinse liquid may drive the solid material alongthe screen toward a side of the filter housing. The solid material entrained in the rinse liquid may flow out through the drain valve 228.

[0070] In some embodiments, the liquid distribution system 200 includes a spray valve 232 between the filter 206 and the spray nozzles 208. The spray valve 232 may be used to increase pressure of the rinse liquid before the drain valve 228 is opened. The configuration in which pressure is building is depicted in FIG. 2B, which shows that the rinse liquid is in fluid communication with the filter 206, but is blocked by the closed valves 228, 232. The configuration in which rinse liquid is flowing is depicted in FIG. 2C, which shows that the rinse liquid can flow out the drain valve 228.

[0071] Pressurizing the filter 206 may improve the removal of solid material from the filter 206 as the rinse liquid begins flowing. For example, the opening of the drain valve 228 may be delayed a preselected amount of time after opening the rinse liquid source 204. As another example, a pressure signal from one or both of the pressure sensors 216, 218 reaching a preselected pressure threshold or a preselected pressure differential may trigger opening of the drain valve 228.

[0072] Closing the spray valve 232 may enable the filter 206 to be at a higher pressure suitable for cleaning the filter 206. In other embodiments, the spray valve 232may be omitted, such as if the spray nozzles 208 will not spray below a certain pressure threshold, and the flow of the rinse liquid is expected to be below that pressure threshold.

[0073] In some embodiments, the waste rinse tank 230 may include a level switch 234 configured to send a signal to the controller 220 indicative of a fluid level in the waste rinse tank 230. The controller 220 may display a status of the waste rinse tank 230 to an operator, such that the operator knows when to empty the waste rinse tank 230. The level switch 234 may include a binary signal (e.g., indicating full or not full) or a range (e.g., a level gauge indicating various fill amounts).

[0074] In certain embodiments, the waste liquid flowing into the waste rinse tank 230 may pass through a flow meter 236 configured to send a signal to the controller 220 indicative of an amount of fluid flowing to the waste rinse tank 230. The controller 220 may display a current flow status, and may calculate a fill status of the waste rinse tank 230 based on cumulative flow through the flow meter 236. The current flow status and / or the fill status of the waste rinse tank 230 may be displayed to the operator, such that the operator knows the liquid distribution system 200 is cleaning the filter 206 and / or when to empty the waste rinse tank 230.

[0075] The spray nozzles 208 are in fluid communication with the filter 206, and are configured to spray liquid received from the product source 202 via the filter 206 to the ground or elsewhere as a liquid spray 238 when in a spraying mode (as depicted in FIG. 2A).

[0076] In some embodiments, the liquid distribution system 200 may include a quality sensor 240 configured to measure a property of liquid leaving the drain valve 228 and entering the waste rinse tank 230. For example, the quality sensor 240 may include, for example, a water quality sensor such as a pH sensor, a turbidity sensor, a dissolved oxygen sensor, a salinity sensor, an ammonia sensor, a chloride sensor, a nitrate sensor, a sulfite sensor, a total organic carbon sensor, a solids sensor, a sensor for detecting any other element or ion, or any other selected sensor. In some embodiments, the quality sensor240 may include an instrument capable of detecting multiple water quality properties, such as those available from Eureka Water Probes, of Austin, Texas, under the names Trimeter and Manta+. The quality sensor 240 may be configured to communicatewith the controller 220, and the controller 220 may use information from the quality sensor 240 to help determine a status of the filter 206. For example, a relatively dirty rinse liquid may indicate that the filter 206 can still be cleaned by applying additional rinse liquid. Use of quality sensors is disclosed generally in U.S. Provisional Patent Application 63 / 585,626, “Sprayer Vehicles, Liquid Distribution Systems for Sprayer Vehicles Comprising a Water Quality Sensor, and Related Methods,” filed September l, 2023.

[0077] After the filter 206 is cleaned, the source valve 214 may be switched back to the position to allow flow from the product source 202, stopping flow from the rinse liquid source 204. The drain valve 228 may then be closed.

[0078] The valves 214, 228, 232 may be electrically or pneumatically actuated, or may be actuated by any other appropriate method. The valves 214, 228, 232 may be ball valves, gate valves, globe valves, etc., or any combination of valve types.

[0079] FIG. 3A is a simplified flow diagram of another liquid distribution system 300, and showing how liquid may flow from the product tank 110 to the boom 112. FIG. 3B is a simplified flow diagram showing pressurization of the filter 206 in preparation for cleaning. FIG. 3C is a simplified flow diagram showing cleaning of the filter 206. The liquid distribution system 300 is configured similar to the liquid distribution system 200 shown in FIG. 2A and described above. However, in the liquid distribution system 200, the rinse liquid from the rinse liquid source 204 enters the filter 206 in the same direction as the flow from the product source 202; in the liquid distribution system 300, the rinse liquid from the rinse liquid source 204 enters the filter 206 in the opposite direction as the flow from the product source 202. The liquid distribution system 200 may be characterized as a direct- flow filter-cleaning system, and the liquid distribution system 300 may be characterized as a backwash filter-cleaning system. In either system, the rinse liquid flows to the waste rinse tank 230, rather than to the spray nozzles 208. Certain differences between the liquid distribution system 200 and the liquid distribution system 300 enable backwash filter cleaning.

[0080] Like the liquid distribution system 200, the product flows from the product source 202 to the filter 206, and then to the spray nozzles 208. However, the rinse liquidenters that flow path after the filter 206, at a spray valve 302. The spray valve 302 is shown as a T-port valve, but may include any selected valve configuration (including multiple valves). For example, the spray valve 302 may include a checkvalve on the flow line from the rinse liquid tank 224, and an on / off valve on the line to the spray nozzles 208. The spray valve 302 may limit or prevent back-flow to the rinse liquid tank 224 when liquid is flowing from the product tank 110, which helps maintain the composition of the rinse liquid (e.g., to avoid contamination).

[0081] The liquid distribution system 300 also includes a checkvalve 304 between the product source 202 and the filter 206 to prevent the rinse liquid from flowing to the product tank 110. In some embodiments, the checkvalve 304 may be replaced with an on / off valve (e.g., electrically or pneumatically actuated) or another type of valve that prevents the rinse liquid from flowing backward to the product source 202 when the liquid distribution system 300 is cleaning the filter 206.

[0082] To initiate a filter cleaning process, the flow of product from the product source 202 is turned off (e.g., by turning off the main pump 210, closing a valve, etc.), and the pressure of the rinse liquid is increased, as depicted in FIG. 3B. FIG. 3B shows that the rinse liquid source 204 is in fluid communication with the filter 206, but flow is blocked by the checkvalve 304 and the closed drain valve 228. The configuration in which rinse liquid is flowing is depicted in FIG. 3C, which shows that the rinse liquid can flow out the drain valve 228 once the drain valve 228 is opened.

[0083] FIG. 4A is a simplified flow diagram of a liquid distribution system 400, which is similar to the liquid distribution system 200 shown in FIG. 2A, but having multiple filters 206, 207 in series. Such filters 206, 207 may be desirably for product sources 202 that are relatively impure. For example, the first filter 206 may be a relatively coarse filter, and the second filter 207 may be a relatively fine filter ( / .e., having a finer mesh size than the first filter 206). Though two filters 206, 207 are shown in FIG.4A, any number of filters may be used in series in the same manner. The use of multiple filters in series may enable each filter to function for a longer time before clogging than one filter alone could.

[0084] Optionally, the liquid distribution system 400 may include an intermediate pressure sensor 219 between the filters 206, 207, which may be used in conjunction with or instead of the first pressure sensor 216 and / or the second pressure sensor 218 to determine when filters are clogged. Placing the intermediate pressure sensor 219 between two filters 206, 207 may enable the operator to determine which filter is clogged, or determine a status of each filter 206, 207 (e.g., percent of useful life remaining).

[0085] The liquid distribution system 400 includes a drain valve 228, 229 for each filter 206, 207.

[0086] As discussed above with respect to FIG. 2A through FIG. 2C, the filters 206, 207 may periodically be cleaned to help ensure the spray nozzles 208 can effectively deliverthe product. The cleaning may be performed in three parts, generally illustrated in FIG. 4B through FIG. 4D. First, pressure at the filters 206, 207 is raised (FIG. 4B), followed by flushing of particulate material from the filter 206 (FIG. 4C) and flushing of particulate material from the other filter 207. Generally, a higher pressure may help to dislodge particulate material. That higher pressure may not be desirable for a spray operation (FIG. 4A). In some embodiments, however, the pressure-building phase may be omitted.

[0087] The rinse liquid source 204 is configured to provide a rinse liquid to clean the filter 206. The rinse liquid source 204 may include a rinse liquid tank 224 and an auxiliary pump 226, as shown, but may alternatively use the pressurized air source 212 to drive liquid and build pressure instead of or in addition to the auxiliary pump 226.

[0088] FIG. 4B through FIG. 4D together illustrate how the rinse liquid source 204 is used to clean the filters 206, 207. In FIG. 4B, the controller 220 may send signals to stop flow of liquid from the product source 202 (e.g., by turning off the main pump 210) and start flow of rinse liquid from the rinse liquid source 204 (e.g., by switching the source valve 214 to provide rinse liquid from the rinse liquid source 204 instead of product from the product source 202). In FIG. 4C, the controller 220 may also send signals to enable the rinse liquid to be drained from the filter 206 (e.g., by opening the drain valve 228 between the filter 206 and a waste rinse tank 230). The rinse liquid source 204 may then deliver the rinse liquid (fresh water, filtered recycled water, a cleaning composition including asurfactant, a solvent, etc.) to the filter 206 to clean the filter 206. The rinse liquid may pass through the filter in a direction that carries solid material out of the filter 206 to the waste rinse tank 230. The solid material entrained in the rinse liquid may flow out through the drain valve 228.

[0089] FIG. 4D illustrates cleaning the filter 207. The drain valve 228 is closed after cleaning the filter 206. Then the drain valve 229 is opened to allow the rinse liquid to pass through the filter 207 and out the drain valve 229 to the waste rinse tank 230. Once the cleaning of filters is complete, the drain valve 229 is closed, the source valve 214 is switched backto the product source 202, the spray valve 232 is opened, and spraying continues as depicted in FIG. 4A. Though cleaning the filters 206, 207 is described as separate actions, in some embodiments two or more filters 206, 207 may be cleaned simultaneously by opening two or more drain valves 228, 229 simultaneously.

[0090] In some embodiments, the intermediate pressure sensor 219 helps the operator determine which of the filters 206, 207 is clogged (or more clogged than the other). In certain situations, the operator may choose to clean only one of the filters 206, 207, and the liquid distribution system 400 may control the valves 214, 228, 229, 232 to clean the selected filter 206, 207. For example, if the product source 202 has relatively large particulate contamination, and the first filter 206 clogs much faster than the second filter 207, the operator may choose to clean only the first filter 206. This may save time and rinse liquid as compared to cleaning both filters 206, 207 each time one filter 206, 207 is clogged.

[0091] The liquid distribution system 300 shown in FIG. 3A through FIG. 3C may also include two or more filters in series. In such embodiments, the spray valve 302 may be downstream of both filters 206, 207, so that the rinse liquid source 204 can be used to clean both filters in a backwash manner.

[0092] FIG. 5A is a simplified flow diagram of a liquid distribution system 500, which is similar to the liquid distribution system 200 shown in FIG. 2A, but having a recycle loop forthe rinse liquid. The use of a recycle loop may enable cleaning of the filter 206 with less rinse liquid. FIG. 5B, FIG. 5C, and FIG. 5D show the liquid distribution system 500 indifferent states. Dashed flow lines in these figures indicate lack of flow due to valve positions.

[0093] FIG. 5A shows the liquid distribution system 500 in use to deliver liquid from the product source 202 to the spray nozzles 208. FIG. 5B shows the flow of the product turned off (e.g., by turning the source valve 214 and / or switching off the main pump 210), and the flow of rinse liquid started (e.g., by turning the source valve 214, a recycle valve 504, and / orturning on the auxiliary pump 226). The spray valve 232 is also closed to prevent the rinse liquid from being sprayed out the spray nozzles 208. The valves in the position shown in FIG. 5B allow pressure to build in the filter 206.

[0094] FIG. 5C shows that when the drain valve 502 is turned to a recycle position, the rinse liquid can flow back to the auxiliary pump 226, and through the filter 206 again. The liquid distribution system 500 may be operated in this configuration for a period of time to clean the filter 206. The rinse liquid source 204 is shown in a position to detect a property of the rinse liquid being recycled. Thus, the rinse liquid may be recycled until the rinse liquid meets preselected characteristics or approaches steady state. For example, the rinse liquid may be recycled until a certain property changes by less than 5% per minute, less than 1% per minute, or less than 0.5% per minute. Alternatively, the quality sensor 240 may be omitted or moved, and the rinse liquid may simply be recycled for a preselected time.

[0095] FIG. 5D shows that, once the recycle is complete, the drain valve 502 is turned again to divert the rinse liquid to the waste rinse tank 230. Once the rinse liquid is purged, the valves can be returned to the positions shown in FIG. 5A, and the liquid from the product source 202 can be sprayed from the spray nozzles 208 once more.

[0096] In some embodiments, one or more checkvalves may be used to ensure no liquid flows backward into the product tank 110 or the rinse liquid tank 224. For example, checkvalves may be in-line from the product tank 110 before the source valve 214, and / or in-line from the rinse liquid tank 224 and before the recycle valve 504. Check valves may enable use of different valves for the source valve 214 and recycle valve 504.

[0097] FIG. 6 is a simplified flow chart illustrating a method 600 of operating a liquid distribution system, such as those depicted in FIG. 2A through FIG. 5D.

[0098] In block 602, a liquid product is provided from a product source through a source valve, one or more filter(s), and at least one spray nozzle.

[0099] In block 604, a control system, tablet, computer, etc., determines a status of the filter(s) based on a signal from at least one pressure sensor.

[0100] In block 606, the status of the filter(s) is shown on a display, such as in the cab of a crop sprayer.

[0101] Block 608 represents terminating flow of the liquid product through the source valve, the filter(s), and the spray nozzle(s). Terminating flow of the liquid product may be performed responsive to a preselected status of the filter(s) (e.g., at least one filter is 75% clogged, 90% clogged, 95% clogged, etc.).

[0102] Block 610 represents providing a rinse liquid from a rinse liquid source to the filter(s).

[0103] Block 612 represents opening a drain valve in fluid communication with one of the filter(s) to enable flow from the rinse liquid source through that filter and the drain valve. The rinse liquid may flow from the rinse liquid source though that filter in a direction of flow opposite to a direction of flow from the product source to the spray nozzle(s), or in the same direction as the direction of flow from the product source to the spray nozzle(s).

[0104] In block 614, a flow rate of the rinse liquid through the drain valve is determined.

[0105] In block 616, a property of the rinse liquid leaving the drain valve is measured.

[0106] In block 618, the rinse liquid is collected in a waste rinse tank.

[0107] In block 620, the drain valve is closed.

[0108] In block 622, a fill condition of the waste rinse tank is determined. If there are multiple filters to be cleaned, the blocks 612 through 622 may be repeated for each filter.

[0109] In block 624, flow of the rinse liquid from the rinse liquid source is terminated.

[0110] In block 626, flow of the liquid product is restarted from the product source through the source valve, the filter, and the spray nozzle(s). Once flow is restarted, the liquid distribution system can repeat any or all of the actions in blocks 604-626.

[0111] Though depicted as a flow chart, the actions in FIG. 6 may be performed concurrently, and in some embodiments, some actions may be omitted. Furthermore, more or fewer of the actions may be repeated than are shown in FIG. 6.

[0112] FIG. 7 shows an embodiment of an example control module 700 that may be used to control operations of the liquid distribution systems 200, 300, 400, 500 of FIG. 2A-FIG. 5D. In one embodiment, the control module 700 includes a controller 702 (e.g., an electronic control unit or ECU) coupled to one or more sensors 704, a user interface 706, one or more pumps 708, and one or more valves 710. The example controller 702 is merely illustrative, and some controllers may have fewer or additional components, and / or some of the functionality associated with the various components depicted in FIG. 7 may be combined, orfurther distributed among additional modules or controllers. Further, though described in the context of residing in a single controller 702, functionality of the controller 702 may be distributed among a plurality of controllers, and in some embodiments, some of the functionality of the controller 702 may be achieved remote from the implement (e.g., if the implement has telecommunications and / or internet connectivity functionality). The controller 702 is depicted in this example as a computer system, but may be embodied as a programmable logic controller (PLC), field programmable gate array (FPGA), application specific integrated circuit (ASIC), among other devices. The controller 702 or some functionality thereof may be included in an existing controller or system associated with the liquid distribution system, such as a machine controller that controls movement of the machine (e.g., steering, height adjustments, track-width adjustment, boom position, etc.). Certain well-known components of computer systems are omitted here to avoid obfuscating relevant features of the controller 702.

[0113] In one embodiment, the controller 702 has one or more processors, such as processor 712, input / output (I / O) interfaces 714, and memory 716, all coupled to one or more data busses, such as data bus 718.

[0114] In one or more embodiments, the processor 712 includes hardware for executing instructions, such as those making up a computer program. As an example, and not byway of limitation, to execute instructions, the processor 712 may retrieve (or fetch) the instructions from an internal register, an internal cache, or the memory 716 and decode and execute them. In one or more embodiments, the processor712 may include one or more internal caches for data, instructions, or addresses. As an example, and not byway of limitation, the processor 712 may include one or more instruction caches, one or more data caches, and one or more translation look aside buffers (TLBs). Instructions in the instruction caches may be copies of instructions in the memory 716.

[0115] The memory 716 may include any one or a combination of volatile memory elements (e.g., random-access memory RAM, such as DRAM, and SRAM, etc.) and nonvolatile memory elements (e.g., ROM, hard drive, tape, CDROM, etc.). The memory 716 may store a native operating system, one or more native applications, emulation systems, or emulated applications for any of a variety of operating systems and / or emulated hardware platforms, emulated operating systems, etc.

[0116] In the embodiment depicted in FIG. 7, the memory 716 includes an operating system 720, detection software 722, and / or control software 724. The detection software 722 may be configured to detect when filter cleaning is to be performed, such as by evaluating pressure drop or operating time. The control software 724 may be configured to carry out the filter cleaning process. In some embodiments, additional or fewer software modules (e.g., combined functionality) may be deployed in the memory 716 or additional memory (or in different devices). In some embodiments, a separate storage device may be coupled to the data bus 718, such as a persistent memory (e.g., optical, magnetic, and / or semiconductor memory and associated drives). The storage device may be a removable device, such as a memory stick or disc.

[0117] In one embodiment, detection software 722 is executed by the processor 712 to receive user input at the user interfaces 706 (e.g., one or a combination of console button, switch, knob, hydro handle or joystick, scroll wheel, display screen with selectable icon displayed on the screen that is manipulated by a mouse or joystick, display screen embodied with selectable icons on a touch-type screen, microphone on a headset or on the console, etc.), and match or associate (e.g., via look-up table or in some embodiments via programmed switch position activation) the input from the sensors 704.

[0118] The user interface 706 may include a display screen coupled to the controller 702 with selectable icons, a hydro handle or joystickwith selectable buttons or switches, a console with switches, button, knobs, scroll wheel, a microphone, etc., with corresponding signals from operator input received at the user interfaces 706 delivered via the I / O interfaces 714 to the detection software 722 executing on the processor 712. The output from the detection software 722 is provided to the user interface 706, which may in turn display an indication of filter status.

[0119] Execution of the detection software 722 and control software 724 may be implemented by the processor 712 under the management and / or control of the operating system 720. For instance, the source statements that embody the method steps or algorithms of the detection software 722 and control software 724 may be translated by one or more compilers of the operating system 720 to assembly language and then further translated to a corresponding machine code that the processor 712 executes to achieve the functionality of the detection software 722 and control software 724. Variations of this execution process are known, depending on the programming language of the software. In some embodiments, the operating system 720 may be omitted and a more rudimentary manner of control implemented. The processor 712 may be embodied as a custom-made or commercially available processor, a central processing unit (CPU) or an auxiliary processor among several processors, a semiconductor based microprocessor (in the form of a microchip), one or more application specific integrated circuits (ASICs), a plurality of suitably configured digital logic gates, and / or other well-known electrical configurationscomprising discrete elements both individually and in various combinations to coordinate the overall operation of the controller 702.

[0120] The I / O interfaces 714 provide one or more interfaces to one or more devices, such as the user interfaces 706, the sensors 704, the pumps 708, and / or the valves 710, among other devices that are coupled directly or indirectly (e.g., over a bus network, such as a CAN network, including one operating according to ISOBUS standards) to the controller 702. The I / O interfaces 714 may also comprise functionality to connect to other networks. For instance, the I / O interfaces 714 may include a network interface that enables remote orwireless communications, such as via telemetry functionality, Bluetooth communications, near-field, among other electromagnetic spectrum communications.

[0121] Still other embodiments involve a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) having processorexecutable instructions configured to implement one or more of the techniques presented herein. An example computer-readable medium that may be devised is illustrated in FIG. 8, wherein an implementation 800 includes a computer-readable storage medium 802 (e.g., a flash drive, CD-R, DVD-R, application-specific integrated circuit (ASIC), field- programmable gate array (FPGA), a platter of a hard disk drive, etc.), on which is computer- readable data 804. This computer-readable data 804 in turn includes a set of processorexecutable instructions 806 configured to operate according to one or more of the principles set forth herein. In some embodiments, the processor-executable instructions 806 may be configured to cause a computer associated with the crop sprayer 102 (FIG. 1 ) to perform operations when executed via a processing unit, such as at least some of the example method 600 depicted in FIG. 6. In other embodiments, the processor-executable instructions 806 may be configured to implement a system, such as at least some of the example crop sprayer 102 depicted in FIG. 1. That is, the controller 220 may include or be connected to the implementation 800 of FIG. 8. Many such computer-readable storage media may be devised by those of ordinary skill in the art that are configured to operate in accordance with one or more of the techniques described herein.

[0122] Systems and methods disclosed herein may be beneficial to clean a filter in a spray system, such as a crop sprayer, to ensure that the spray system can operate as designed. Cleanin the filter may be beneficial if the product sprayed contains a significant amount of solid material. If the product includes water that is not well filtered before being loaded into the spray system (e.g., river water, as opposed to culinary water, for example), filtering within the spray system may be particularly beneficial. However, dirtier product will lead to more frequent filter clogging. As disclosed herein, the filter may be cleaned without conventional actions such as physically removing the filter, washing it, and replacing it while the machine is stopped. Thus, the methods may save time, and may allowthe operatorto avoid physical contact with the filter or a cleaning solution. Thus, the operator may not need to don personal protective equipment (e.g., gloves, safety goggles, etc.) to clean the filter. By simplifying the filter-cleaning process, the operator may be more likely to clean the filter regularly, which may lead to more consistent operation of the spray system.

[0123] All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.

Claims

CLAIMS1. A liquid distribution system, comprising: a product source configured to contain a product to be distributed; at least one filter in fluid communication with the product source; a rinse liquid source configured to contain a rinse liquid; at least one spray nozzle in fluid communication with the at least one filter and configured to spray the product received from the product tank via the at least one filter; a source valve between the product source and the at least one filter; at least one drain valve in fluid communication with the at least one filter; and a controller configured to clean the at least one filter by: stopping flow of the product from the product source through the source valve; delivering the rinse liquid from the rinse liquid source to the at least one filter; and openingthe at least one drain valve.

2. The liquid distribution system of claim 1 , further comprising a waste rinse tank, wherein the at least one drain valve is configured to deliver the rinse liquid to the waste rinse tank.

3. The liquid distribution system of claim 1 or 2, wherein the product source comprises a product tank.

4. The liquid distribution system of any one of claims 1 to 3, wherein the product source comprises a main pump.

5. The liquid distribution system of claim 4, wherein stopping flow of the product from the product source comprises turning off the main pump.

6. The liquid distribution system of any one of claims 1 to 5, wherein the product source comprises a pressurized air source.

7. The liquid distribution system of any one of claims 1 to 6, wherein the rinse liquid source comprises a rinse liquid tank.

8. The liquid distribution system of any one of claims 1 to 7, wherein the rinse liquid source comprises an auxiliary pump.

9. The liquid distribution system of claim 8, wherein delivering the rinse liquid from the rinse liquid source to the at least one filter comprises turning on the auxiliary pump.

10. The liquid distribution system of any one of claims 1 to 9, wherein the rinse liquid source comprises a pressurized air source.11 . The liquid distribution system of any one of claims 1 to 10, further comprising a spray valve between the at least one filter and the at least one spray nozzle.

12. The liquid distribution system of any one of claims 1 to 11 , wherein delivering the rinse liquid from the rinse liquid source to the at least one filter comprises delivering the rinse liquid from the rinse liquid source though the at least one filter in a direction of flow opposite to a direction of flow from the product source to the at least one spray nozzle.

13. The liquid distribution system of any one of claims 1 to 11 , wherein delivering the rinse liquid from the rinse liquid source to the at least one filter comprises delivering the rinse liquid from the rinse liquid source though the at least one filter in a same direction of flow as a direction of flow from the product source to the at least one spray nozzle.

14. The liquid distribution system of any one of claims 1 to 13, further comprising a level switch configured to send a signal to the controller indicative of a fluid level in the waste rinse tank.

15. The liquid distribution system of any one of claims 1 to 14, further comprising a flow meter configured to send a signal to the controller indicative of an amount of rinse fluid flowing to the waste rinse tank.

16. The liquid distribution system of any one of claims 1 to 15, further comprising a quality sensor configured to measure a property of liquid entering the waste rinse tank.

17. The liquid distribution system of any one of claims 1 to 16, further comprising a first pressure sensor configured to measure a pressure between the product source and the at least one filter.

18. The liquid distribution system of any one of claims 1 to 17, further comprising a second pressure sensor configured to measure a pressure between the at least one filter and the at least one spray nozzle.

19. The liquid distribution system of any one of claims 1 to 18, wherein the at least one filter comprises at least two filters in series.

20. The liquid distribution system of claim 19, further comprising an intermediate pressure sensor between the at least two filters.21 . The liquid distribution system of any one of claims 1 to 20, wherein the at least one drain valve comprises a drain valve corresponding to each filter of the at least one filter.

22. The liquid distribution system any one of claims 1 to 21 , further comprising a recycle valve, wherein the recycle valve in an open position fluidly connects the at least one drain valve with the source valve.

23. The liquid distribution system of any one of claims 1 to 22, wherein the at least one spray nozzle comprises a plurality of spray nozzles spaced along a boom.

24. An agricultural crop sprayer comprising the liquid distribution system of any one of claims 1 to 23.

25. A method of operating a liquid distribution system, the method comprising:providing a liquid product from a product source through a source valve, at least one filter, and at least one spray nozzle; terminating flow of the liquid product through the source valve, the at least one filter, and the at least one spray nozzle; providing a rinse liquid from a rinse liquid source to the at least one filter; opening at least one drain valve in fluid communication with the at least one filterto enable flow from the rinse liquid source through the at least one filter and the at least one drain valve; terminating flow of the rinse liquid from the rinse liquid source; and restarting flow of the liquid product from the product source through the source valve, the at least one filter, and the at least one spray nozzle.

26. The method of claim 25, wherein opening at least one drain valve comprises: opening a first drain valve in fluid communication with a first filter of the at least one filter; closing the first drain valve; and opening a second drain valve in fluid communication with a second filter of the at least one filter.

27. The method of claim 25 or 26, wherein providing the rinse liquid from the rinse liquid source to the at least one filter comprises providing the rinse liquid from the rinse liquid source to the at least one filter in a direction of flow opposite to a direction of flow from the product source to the at least one spray nozzle.

28. The method of claim 25 or 26, wherein providing the rinse liquid from the rinse liquid source to the at least one filter comprises providing the rinse liquid from the rinse liquid source to the at least one filter in a same direction of flow as a direction of flow from the product source to the at least one spray nozzle.

29. The method of any one of claims 25 to 28, further comprising determining a status of the at least one filter based on a signal from at least one pressure sensor.

30. The method of claim 29, wherein terminating flow of the liquid product through the source valve, the at least one filter, and the at least one spray nozzle is performed responsive to a preselected status of the at least one filter.31 . The method of claim 29 or 30, further comprising displaying the status of the at least one filter on a display.

32. The method of any one of claims 25 to 31 , further comprising determining a flow rate of the rinse liquid through the at least one drain valve.

33. The method of any one of claims 25 to 32, further comprising collecting the rinse liquid in a waste rinse tank.

34. The method of claim 33, further comprising determining a fill condition of the waste rinse tank.

35. The method of any one of claims 25 to 34, further comprising measuring a property of the rinse liquid flowing through the at least one drain valve.

36. The method of any one of claims 25 to 35, further comprising recycling the rinse liquid through the at least one filter.

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