CN117062981A

CN117062981A - Double-diaphragm slurry pump

Info

Publication number: CN117062981A
Application number: CN202280019669.8A
Authority: CN
Inventors: T·斯旺森; K·利维; R·哈曼; J·加诺萨
Original assignee: Precision Planting LLC
Current assignee: Precision Planting LLC
Priority date: 2021-05-20
Filing date: 2022-05-11
Publication date: 2023-11-14
Also published as: CN116940760A; CN116963826A; CN116981926A; CN116940761A; CN116964325A

Abstract

A double diaphragm pump (7080), the double diaphragm pump comprising: a pump body (8200) defining a vertical Longitudinal Axis (LA), a first pumping chamber (8201) and a second pumping chamber (8202); an inlet flow manifold (8203) and an outlet flow manifold (8204) coupled to the pump body; a first pump head (8230 a) coupled to the pump body adjacent the first pumping chamber, the first pump head comprising a longitudinal flow bore (8231) separate from the first pumping chamber and fluidly coupled to the inlet and outlet flow manifolds, an upper vent bore (8232), and a lower slurry exchange bore (8233) each fluidly coupling the longitudinal flow bore, and thus, the first pumping chamber; an operating shaft (8240) coupled to an elastically deformable diaphragm (8241) arranged within the first pumping chamber; wherein the shaft is movable during a pump stroke to pump fluid from the inlet flow manifold to the outlet flow manifold through the longitudinal bore of the first pump head and the first pumping chamber; wherein the diameter of the upper vent hole (8232) is smaller than the diameter of the lower slurry exchange hole (8233) such that air is preferentially discharged from the first pumping chamber instead of slurry during the pumping stroke.

Description

Double-diaphragm slurry pump

Cross Reference to Related Applications

The present application is a continuation of U.S. application Ser. No.17/326050, filed 5/20 of 2021, and claims the benefits of U.S. provisional application Ser. Nos. 63/191186, 63/191189, 63/191195, 63/191199, and 63/191204, both filed 5/20 of 2021. The foregoing applications are incorporated by reference in their entirety.

Technical Field

The present disclosure relates generally to agricultural sampling and analysis, and more particularly to fully automated systems for performing soil and other types of agricultural related sampling and chemical property analysis.

Background

Periodic soil testing is an important aspect of agricultural technology. The test results provide valuable information about the chemical composition of the soil, such as plant available nutrients and other important characteristics (e.g., levels of nitrogen, magnesium, phosphorus, potassium, pH, etc.), so that various modifiers can be added to the soil to maximize the quality and yield of crop production.

In some existing soil sampling processes, the collected sample is dried, ground, water is added, and then filtered to obtain a soil slurry suitable for analysis. An extractant is added to the slurry to extract plant available nutrients. The slurry is then filtered to produce a clarified solution or supernatant that is mixed with a chemical reagent for further analysis.

It is desirable to improve testing of soil, vegetation and fertilizer.

Disclosure of Invention

The present invention provides an automated computer-controlled sampling system and related method for collecting, processing and analyzing agricultural samples, such as, but not limited to, soil samples in one embodiment, for various chemical characteristics such as plant-available nutrients. The sampling system allows for processing and analyzing multiple samples in a simultaneous or semi-simultaneous manner, relatively continuously and in rapid succession, for different analytes (e.g., plant-available nutrients) and/or chemical characteristics (e.g., pH). Advantageously, the system can process soil samples or other types of agricultural samples under "as-collected" conditions without the need for cumbersome drying and grinding steps in the previous processing described previously.

The present system generally includes a sample preparation subsystem that receives soil or other types of agricultural samples and produces agricultural slurry (i.e., a mixture of soil, vegetation, and/or fertilizer and water), and a chemical analysis subsystem that receives and processes the prepared slurry sample from the sample preparation subsystem for quantification of analytes and/or chemical properties of the sample. Agricultural samples may be collected automatically by the probe collection subsystem or by other methods including manual sampling may be provided. The described chemical analysis subsystem may be used to analyze agricultural slurries that may be composed of soil, vegetation, fertilizer, emulsion, or other types of samples.

In one embodiment, the sample preparation system generally includes a mixing device that mixes the raw soil sample in a "as sampled" (e.g., undried and unground) condition with a diluent such as water to form a sample slurry. The unfiltered slurry is then coarsely filtered through a coarse filter unit to remove oversized solid particles larger than desired, which may include foreign matter debris in the sample and/or hardened agglomerates of agricultural sample solids that are not completely broken down by the mixing device. The filtered slurry (filtrate) then enters a closed slurry recirculation flow loop configured to circulate slurry for determining the water to solids ratio of the slurry. As further described herein, the various components forming an integral part of the flow circuit are configured to circulate the slurry in the closed flow circuit, inhibit pressure spikes, measure slurry density, and measure the density of the solid particulate component of the slurry. The operation of some or all of the system and flow circuit components may be controlled by a programmable system controller. The system measures the actual water to solids ratio and compares this measurement to the desired target water to soil ratio required for subsequent chemical analysis of the slurry to quantify the level or concentration of the analyte of interest (e.g., soil nutrient or other parameter). The system is configured to add water to the closed flow loop to achieve a target water to soil ratio.

Once the target water to soil ratio is reached, the slurry is extracted from the slurry recirculation flow loop and filtered through a fine filter unit that forms a component of the slurry recirculation flow path. The extracted and filtered slurry is then processed through a chemical analysis subsystem that quantifies the concentration or level of one or more analytes of interest. The chemical analysis subsystem performs the following general functions: adding/mixing an extractant to the slurry, separating a clarified supernatant from the slurry, adding/mixing a color-changing reagent to the supernatant, and finally sensing or analyzing for detection of the analyte and/or chemical property, e.g., via colorimetric analysis or other analytical techniques.

While sampling systems (e.g., sample collection, preparation, and processing) may be described herein with respect to processing soil samples, which represents one type of use of the disclosed embodiments, it should be understood that the same systems including equipment and related processes may also be used to process other types of agriculturally-relevant samples including, but not limited to, vegetation/vegetation, forage, fertilizer, feed, emulsion, or other types of samples. Accordingly, the embodiments of the invention disclosed herein should be broadly considered as agricultural sampling systems. Thus, the invention is obviously not limited to the treatment and analysis of soil samples for chemical properties of interest.

Drawings

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein like elements are labeled similarly, and wherein:

FIG. 1 is a schematic flow diagram of an agricultural sampling analysis system according to the present disclosure, illustrating high-level functional aspects of each subsystem of the sampling analysis system;

FIG. 2 is a schematic system diagram of a programmable processor-based Central Processing Unit (CPU) or system controller for controlling the systems and devices disclosed herein;

FIG. 3 is a basic schematic of a first embodiment of an agricultural sample analysis system;

FIG. 4 is a basic schematic of a second embodiment of an agricultural sample analysis system including closed flow loop slurry recirculation;

FIG. 5 is a perspective view of a first embodiment of a slurry densitometer that may be used in the system of FIG. 44A or FIG. 44B;

FIG. 6 is a first side view thereof;

FIG. 7 is a second side view thereof;

FIG. 8 is a first end view thereof;

FIG. 9 is a second end view thereof;

FIG. 10 is a top view thereof;

FIG. 11 is a bottom view thereof;

FIG. 12 is a first longitudinal cross-sectional view thereof;

FIG. 13 is a second longitudinal cross-sectional view thereof;

FIG. 14 is a longitudinal perspective cut-away view thereof;

FIG. 15 is a first perspective view of a second embodiment of a slurry densitometer that may be used in the system of FIG. 44A or FIG. 44B;

FIG. 16 is a second perspective view thereof;

FIG. 17 is a third perspective view thereof with the control system enclosure removed;

fig. 18 is a longitudinal sectional view thereof;

FIG. 19A shows a portion of an oscillator tube of a densitometer showing the accumulation of iron particles in the slurry on the inside of the tube caused by the magnetic field of a permanent magnet attached to the tube;

FIG. 19B shows a first embodiment of a magnetic isolation member attached to an oscillator tube;

FIG. 19C shows a second embodiment of a magnetic isolation member attached to an oscillator tube;

FIG. 19D shows a third embodiment of a magnetic isolation member attached to an oscillator tube;

FIG. 19E shows a fourth embodiment of a magnetic isolation member attached to an oscillator tube;

FIG. 19F illustrates a possible directional vibratory motion of the oscillator tube;

FIG. 19G shows an oscillator tube mounted in a vertical orientation;

FIG. 20 is a first perspective view of a first embodiment of a fine filter unit;

FIG. 21 is a second perspective view thereof;

FIG. 22 is a bottom view thereof;

FIG. 23 is a top view thereof;

FIG. 24 is a side cross-sectional view thereof;

FIG. 25 is a first perspective view of a second embodiment of a fine filter unit;

FIG. 26 is a second perspective view thereof;

FIG. 27 is an end view thereof;

FIG. 28 is a top view thereof;

FIG. 29 is a side cross-sectional view thereof;

FIG. 30 is a schematic diagram of a pumpless system for blending soil slurry using pressurized air;

fig. 31 is a first graph showing the dilution amount of a diluent (e.g., water) added to the slurry versus the slurry density;

FIG. 32 is a second chart thereof;

FIG. 33 is a third chart thereof;

FIG. 34 is a schematic equipment and flow diagram of an alternative embodiment of an agricultural slurry preparation system according to an agricultural sampling analysis system;

FIG. 35 is a schematic block flow diagram of an agricultural sampling analysis system incorporating the slurry preparation system of FIG. 34;

FIG. 36 is a top perspective view of a coarse filter unit of the agricultural slurry preparation system;

FIG. 37 is an exploded view thereof;

FIG. 38 is a bottom perspective thereof;

FIG. 39 is a first side view thereof;

FIG. 40 is a second side view thereof;

FIG. 41 is a longitudinal cross-sectional view thereof;

FIG. 42 is an enlarged detail taken from FIG. 41;

FIG. 43 is a transverse cross-sectional view of the coarse filter unit;

FIG. 44 is a top perspective view of an accumulator of the agricultural slurry preparation system;

FIG. 45 is a bottom perspective view thereof;

FIG. 46 is a top exploded perspective view thereof;

FIG. 47 is a bottom exploded perspective thereof;

FIG. 48 is a longitudinal cross-sectional view thereof;

FIG. 49 is an end view of the inlet end of the accumulator;

FIG. 50 is a transverse cross-sectional view thereof;

FIG. 51 is a top perspective view of a stirring device of the agricultural slurry preparation system;

FIG. 52 is a top view thereof;

FIG. 53 is a bottom view thereof;

FIG. 54 is a left side view thereof;

FIG. 55 is a right side view thereof;

FIG. 56 is a front view thereof;

fig. 57 is a rear view thereof;

FIG. 58 is a side longitudinal cross-sectional view thereof;

FIG. 59 is a front longitudinal cross-sectional view thereof;

FIG. 60 is a transverse cross-sectional view thereof showing a drive gear arrangement;

FIG. 61 is a lower transverse cross-sectional view thereof showing the vane assembly;

FIG. 62 is an exploded top perspective view thereof showing portions of the motor and drive gear arrangement separated;

FIG. 63 is a perspective view of a bottom section of the stirring device;

FIG. 64 is a transverse cross-sectional view of a pneumatic double diaphragm (AODD) pump of the agricultural slurry preparation system, showing the pump in a first operational pumping position;

FIG. 65 is a transverse cross-sectional view thereof showing the pump in a second operational pumping position;

FIG. 66 is a first perspective view of one pump head of the pump showing the inside and attached inlet and outlet check valves;

FIG. 67 is a second perspective view thereof, showing the opposite outer side;

FIG. 68 is a perspective view thereof showing the inlet valve in an exploded state;

FIG. 69 is a plan view of the inside of the pump head and valve assembly;

Fig. 70 is a longitudinal sectional view thereof.

All of the drawings are not necessarily drawn to scale. Unless explicitly stated otherwise, components that appear numbered in one figure but not in other figures are identical. Unless explicitly stated otherwise, references herein to complete figure numbers appearing in multiple figures with the same complete number but with different letter suffixes should be construed as referring generally to all of these figures.

Detailed Description

Features and benefits of the present invention are illustrated and described herein with reference to exemplary ("example") embodiments. This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. Thus, the present disclosure should not be expressly limited to such exemplary embodiments as illustrate some possible non-limiting combinations of features that may be present alone or in other combinations of features.

In the description of the embodiments disclosed herein, any reference to direction or orientation is for descriptive convenience only and is not intended to limit the scope of the invention in any way. Relative terms (such as "lower," "upper," "horizontal," "vertical," "above," "below," "upward," "downward," "top" and "bottom") and derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be configured or operated in a particular orientation. Terms such as "attached," "fixed," "connected," "coupled," "interconnected," and the like refer to the relationship: structures are fixed or attached to each other either directly or indirectly through intervening structures, including both movable or rigid attachments or relationships, unless expressly described otherwise.

As used throughout, any range disclosed herein is used as a shorthand for describing each and every value that is within the range. Any value within a range can be selected as the end of the range. In addition, all references cited herein are incorporated by reference in their entirety. In the event of a conflict between a definition in the present disclosure and a definition of a cited reference, the present disclosure controls.

Fig. 1 is a schematic flow diagram of an agricultural sampling system 3000 according to the present disclosure. The subsystems disclosed herein collectively provide for the complete processing and chemical analysis of agricultural samples, from sample preparation to final chemical analysis collected in the farmland. In one embodiment, system 3000 may be incorporated into a motorized sampling vehicle configured to travel through a farm to collect and process soil samples from various areas of the farm. This allows for accurate generation of a comprehensive nutrient and chemical profile of the field in order to quickly and conveniently determine the soil amendment and application amount required for each area based on quantification of the nutrient and/or chemical characteristics available to the plants in the sample. The system 3000 advantageously allows for simultaneous processing and chemical analysis of multiple samples for various chemical components or characteristics, such as, for example and without limitation, plant-available nutrients. In one embodiment, the sampling system may be a soil sampling system configured to determine nutrient levels in different portions of a farmland for crop production. However, the sampling system may be used for various other types of agricultural sampling as previously described herein.

Agricultural sampling system 3000 generally includes a sample probe collection subsystem 3001, a sample preparation subsystem 3002, and a chemical analysis subsystem 3003. Sample collection subsystem 3001 and motorized sampling vehicle are fully described in U.S. patent publication No. 2018/0123992 A1. In the case of soil sampling, the sample collection subsystem 3001 typically performs the function of extracting and collecting soil samples from the field. The sample may be in the form of a soil plug or wick. The collected cores are transferred to a holding chamber or container for further processing by the sample preparation subsystem 3002. Other sampling systems have filed on day 28, 2 in 2020, U.S. application Ser. No. 62/983237; 63/017789 submitted on 30 th 4 th 2020; 63/017840 submitted on 30 th 4 th 2020; 63/018120 was submitted on 30 th 4 th 2020; 63/018153 submitted on 30 th 4 th 2020; 63/191147 submitted on day 20 of 5 of 2021; 63/191159, filed 5.20.2021; 63/191166 submitted on day 20, 5, 2021; 63/191172 submitted on day 5 and day 20 of 2021; 17/326050 submitted at 20/5/2021; 63/191186 submitted at 20/5/2021; 63/191189 submitted on day 20, 5, 2021; 63/191195 submitted at 20/5/2021; 63/191199 submitted at 20/5/2021; 63/191204 submitted on day 20, 5, 2021; 17/343434 submitted at 2021, 6 and 9; 63/208865 submitted at 9 of 2021; 17/343536 submitted at 2021, 6, 9; 63/213319 submitted at 22/6/2021; 63/260772 submitted at month 31 of 2021; 63/260776 submitted at month 31 of 2021; 63/260777 submitted at month 31 of 2021; 63/245278 submitted on 9.17.2021; 63/264059 submitted on day 11, 15 of 2021; 63/264062 submitted at 11/15 of 2021; 63/264065 submitted on day 11, 15 of 2021; 63/268418 submitted at 2/23 of 2022; 63/268419 submitted at 2/23 of 2022; 63/268990 submitted at 3/8 of 2022; PCT/IB2021/051076 submitted on month 2 and 10 of 2021; PCT application No. PCT/IB2021/051077 filed on 10/2/2021; PCT/IB2021/052872 submitted at 4/7 of 2021; PCT/IB2021/052874 submitted at 4/7 of 2021; PCT/IB2021/052875 submitted at 4/7 of 2021; PCT/IB2021/052876, filed on 7/4/2021.

Sample preparation subsystem 3002 typically performs the following functions: the method includes receiving agricultural sample solids or cores in a mixing device, adding a predetermined amount or volume of filtered water, mixing the soil and water mixture to produce a sample slurry, coarsely filtering the slurry and transferring the filtered slurry to a stirring device that is part of a closed slurry recirculation flow loop and flow path, recirculating the slurry in the flow loop, measuring the actual water-to-soil ratio of the slurry, and diluting the slurry with water to a target water-to-soil ratio.

The chemical analysis subsystem 3003 typically performs the following functions: drawing or extracting the slurry from the slurry recirculation flow loop through a fine filter unit, adding an extractant, mixing the extractant and slurry to extract the analyte of interest (e.g., plant available nutrients, etc.), treating the extractant-slurry mixture to produce a clear liquid or supernatant, removing or transferring the supernatant, injecting a reagent, and holding the supernatant-reagent mixture for a holding time to allow complete chemical reaction with the reagent, and measuring the analyte, such as by absorbance via colorimetric analysis or another analytical technique.

The sample preparation and chemical analysis subsystems 3002, 3003 and their devices or components will now be described in more detail.

As already noted herein, the agricultural sampling systems, subsystems and related processes/methods disclosed herein may be used to treat and test soil, vegetation/plants, fertilizer, feed, emulsion or other agricultural related parameters of interest. In particular, embodiments of the chemical analysis portion of the system disclosed herein (chemical analysis subsystem 3003) may be used to test for a variety of chemically related parameters and analytes (e.g., nutrients/chemicals of interest) in other fields than soil and plant/vegetation sampling. Some non-limiting examples (including soil and plants) are as follows.

Soil analysis: nitrate, nitrite, total nitrogen, ammonium, phosphate, orthophosphate, polyphosphate, total phosphate, potassium, magnesium, calcium, sodium, cation exchange capacity, pH, percentage of alkali saturation of cations, sulfur, zinc, manganese, iron, copper, boron, soluble salts, organics, excess lime, activated carbon, aluminum, amino sugar nitrate, ammoniacal nitrogen, chloride, carbon to nitrogen ratio, conductivity, molybdenum, texture (sand, silt, clay), cyst line egg count, mineralized nitrogen, and soil void space.

Plants/vegetation: nitrogen, nitrate, phosphorus, potassium, magnesium, calcium, sodium, percent of base saturation of cations, sulfur, zinc, manganese, iron, copper, boron, ammoniacal nitrogen, carbon, chloride, cobalt, molybdenum, selenium, total nitrogen, and living plant parasitic nematodes.

And (3) fertilizer: moisture/total solids, total nitrogen, organic nitrogen, phosphate, potash fertilizer, sulfur, calcium, magnesium, sodium, iron, manganese, copper, zinc, pH, total carbon, soluble salts, carbon to nitrogen ratio, ammoniacal nitrogen, nitrate nitrogen, chloride, organic matter, ash, conductivity, kjeldahl nitrogen, escherichia coli, salmonella, total kjeldahl nitrogen, total phosphate, potash fertilizer, nitrate nitrogen, water-soluble nitrogen, water-insoluble nitrogen, ammoniacal nitrogen, humic acid, pH, total organic carbon, bulk density (package), moisture, sulfur, calcium, boron, cobalt, copper, iron, manganese, arsenic, chloride, lead, selenium, cadmium, chromium, mercury, nickel, sodium, molybdenum, and zinc.

Feed: alanine, histidine, proline, arginine, isoleucine, serine, aspartic acid, leucine, threonine, cystine, lysine, tryptophan, glutamic acid, methionine, tyrosine, glycine, phenylalanine, valine (crude protein is required), arsenic, lead, cadmium, antimony, mercury.

Vitamin E (beta-tocopherol), vitamin E (alpha-tocopherol), vitamin E (delta-tocopherol), vitamin E (gamma-tocopherol), vitamin E (total), moisture, crude protein, calcium, phosphorus, ADF, ash, TDN, energy (digestible and metabolizable), net energy (gain, lactation, maintenance), sulfur, calcium, magnesium, sodium, manganese, zinc, potassium, phosphorus, iron, copper (not suitable for premix), saturated fat, monounsaturated fat, omega 3 fatty acid, polyunsaturated fat, trans fatty acid, omega 6 fatty acid (crude fat or acid needed), glucose, fructose, sucrose, maltose, lactose, aflatoxin (B1, B2, G1, G2), vomitoxin, fumonisin, ochratoxin, T2-toxin, zearalenone, vitamin B2, B3, B5, B6, B7, B9 and B12, calories, chloride, crude fiber, neutral fiber, selenium, non-protein, nitrogen, total iodine, starch, total free starch, vitamin D, and free fatty acid.

Feed: moisture, crude protein, acid wash fiber ADF, NDF, TDN, net energy (weight gain, lactation, maintenance), relative feed value, nitrate, sulfur, copper, sodium, magnesium, potassium, zinc, iron, calcium, manganese, sodium, phosphorus, chloride, fiber, lignin, molybdenum, hydrocyanic acid, and selenium USP.

Emulsion: milk fat, pure protein, somatic cell count, lactose, other solids, total solids, added water, emulsion urea nitrogen, acidity, pH, antibiotic testing, and microorganisms.

Although testing soil is described below, any extraction, analysis, or measurement system may be used with any of the above materials.

Control system

Fig. 2 is a schematic system diagram illustrating a control or processing system 2800 that includes a programmable processor-based Central Processing Unit (CPU) or system controller 2820 as referenced herein. The system controller 2820 may include one or more processors, non-transitory tangible computer readable media, programmable input/output peripherals, and all other necessary electronic accessories typically associated with a full-function processor-based controller. A control system 2800 including a controller 2820 is operatively and communicatively linked to the various soil sample processing and analysis systems and devices described elsewhere herein via suitable communication links to control the operation of these systems and devices in a fully integrated and serial manner.

Referring to fig. 2, a control system 2800 including a programmable controller 2820 may be mounted on a fixed support at any location, or conversely on a translatable self-propelled or towed machine (e.g., vehicle, tractor, combine, etc.), which may include agricultural implements (e.g., planter, cultivator, plow, sprayer, spreader, irrigation tool, etc.), according to one embodiment. In one example, a machine performs an operation of a tractor or vehicle coupled to an implement for agricultural operations. In other embodiments, the controller may be part of a fixed station or facility.

Whether on a translatable machine or external thereto, the control system 2800 generally includes a controller 2820, a non-transitory tangible computer or machine-accessible and readable medium (e.g., memory 2805), and a network interface 2815. The computer or machine-accessible and readable medium may include any suitable volatile memory and non-volatile memory or device operably and communicatively coupled to the one or more processors. Any suitable combination and type of volatile or nonvolatile memory may be used including, by way of example and not limitation, random Access Memory (RAM) and its various types, read Only Memory (ROM) and its various types, hard disks, solid state drives, flash memory, or other memory and devices that may be written to and/or read by a processor operatively connected to the medium. Both volatile and nonvolatile memory may be used for storing program instructions or software. In one embodiment, a computer or machine-accessible and readable non-transitory medium (e.g., memory 2805) contains executable computer program instructions that, when executed by system controller 2820, cause the system to perform operations or methods of the present disclosure including measuring characteristics and testing of soil and plant samples. While in the exemplary embodiment, the machine-accessible and readable non-transitory medium (e.g., memory 2805) is shown to be a single medium, this term should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of control logic or instructions. The term "machine-accessible and readable non-transitory medium" shall also be taken to include a set of instructions that are capable of storing, encoding or carrying any one or more of the methodologies performed by the machine and that cause the machine to perform the present disclosure. The term "machine-accessible and readable non-transitory medium" shall accordingly also be taken to include, but not be limited to, solid-state memories, optical and magnetic media, and carrier wave signals.

The network interface 2815 communicates with agricultural (e.g., soil or other) sample processing and analysis systems (and their associated devices) described elsewhere (collectively 2803 in fig. 2) and other systems or devices, which may include, but are not limited to, implements 2840 with their own controllers and devices.

The programmable controller 2820 may include one or more microprocessors, processors, system-on-chip (integrated circuits), one or more microcontrollers, or a combination thereof. The processing system includes processing logic 2826 for executing software instructions of one or more programs and a communication module or unit 2828 (e.g., transmitter, transceiver) for transmitting and receiving messages from the network interface 2815 and/or the agricultural sample processing and analysis system 2803, which includes the sample preparation subsystem 3002 and the components described herein, which further include the closed slurry recirculation flow loop 8002 components. The communication unit 2828 may be integrated with the control system 2800 (e.g., controller 2820) or separate from the programmable processing system.

The programmable processing logic 2826 of the control system 2800, which directs the operation of the system controller 2820, including one or more processors, may process messages received from the communication unit 2828 or the network interface 2815, including agricultural data (e.g., test data, test results, GPS data, liquid application data, flow rates, etc.), as well as data generated by the soil sample processing and analysis system 2803. The memory 2805 of the control system 2800 is configured for preprogrammed variables or set point/baseline values, storing collected data and computer instructions or programs (e.g., software 2806) for execution for controlling the operation of the controller 2820. Memory 2805 may store, for example, software components such as test software for analyzing soil and vegetation samples to perform the operations of the present disclosure, or any other software applications or modules, images 2808 (e.g., captured crop images), alarms, maps, and the like. The system 2800 may also include an audio input/output subsystem (not shown) that may include a microphone and speaker for receiving and transmitting voice commands or for user authentication or authorization (e.g., biometrics), for example.

The system controller 2820 communicates bi-directionally with the memory 2805 via communication link 2830, with the network interface 2815 via communication link 2832, with the display device 2830 and optional second display device 2825 via communication links 2834, 2835, and with the I/O port 2829 via communication link 2836. System controller 2820 may also communicate with soil sample processing and analysis system 2803 via network interface 2815 and/or directly over wired/wireless communication link 5752 as shown.

Display devices 2825 and 2830 may provide a visual user interface to a user or operator. The display device may include a display controller. In one embodiment, the display device 2825 is a portable tablet or computing device having a touch screen that displays data (e.g., test results of soil, test results of vegetation, liquid application data, captured images, partial view map layers, high definition field maps such as applied liquid application data, such as planted or such as harvested data or other agricultural variables or parameters, yield maps, alarms, etc.) and data generated by an agricultural data analysis software application and receives input from a user or operator of an exploded view of an area of the field to monitor and control field operation. Operations may include configuration of the machine or implement, reporting of data, control of the machine or implement including sensors and controllers, and storage of the generated data. The display 2830 may be a display (e.g., a display provided by an Original Equipment Manufacturer (OEM)) that displays images and data for a partial view map layer, liquid application data as applied, data as planted or as harvested, yield data, control machines (e.g., a planter, tractor, combine, sprayer, etc.), handle the machine, and monitor the machine or an implement (e.g., planter, combine, sprayer, etc.) connected to the machine using sensors and controllers located on the machine or implement.

Modification of agricultural sample slurry processing system

The following sections describe various aspects of the foregoing agricultural sample analysis systems and associated devices described previously herein that process and analyze/measure prepared agricultural sample slurries for analytes of interest (e.g., soil nutrients such as nitrogen, phosphorus, potassium, etc., vegetation, fertilizer, etc.). In particular, modifications relate to the sample preparation 3002 and chemical analysis 3003 portions of the agricultural (e.g., soil or other) sampling system 3000 shown in fig. 1. To provide a broad context for discussing alternative devices and equipment below, FIG. 3 is a high-level schematic system diagram summarizing the processing flow sequence of an agricultural sample analysis system. This example illustrates static slurry batch mode density measurement as further described herein. Fig. 4 is essentially the same, but adds and includes a slurry recirculation loop between the fine filtration station and the sample preparation mixing chamber for dynamic continuous mode slurry density measurement.

Referring now to fig. 3 and 4, agricultural sample analysis system 7000 includes, in flow path order, agricultural sample preparation subsystem 7001, density measurement subsystem 7002, fine filtration subsystem 7003, analyte extraction subsystem 7004, ultra-fine filtration subsystem 7005, and analyte measurement subsystem 7006. Soil sample preparation subsystem 7001 represents the portion of the system where sample slurry is initially prepared. Accordingly, subsystem 7001 may include a mixing device 8010 described herein, including: a mixing chamber in which water is added to a bulk agricultural sample (e.g., soil or other agricultural solids) to prepare a slurry; and a coarse filter (e.g., filter unit 8020) described herein that removes larger or oversized particles (e.g., small stones, crushed stones, debris, hardened clumps of agricultural solids, etc.) from the prepared soil slurry. In addition, the coarse filter is sized to pass through a desired maximum particle size in the slurry to ensure uniform flow and density of the slurry for weight/density measurements used in the process, as further described herein. The prepared and coarsely filtered slurry may be transferred from the mixing device to the density measurement subsystem 7002 via pumping by the slurry pump 7081 or alternatively pneumatically pressurizing a flow conduit between the mixing device 8010 and the filter unit 8020 via pressurized air provided by a fluid coupling to a pressurized air source 7082 (shown in phantom in fig. 3).

Analyte extraction subsystem 7004 and measurement subsystem 7006 may include agricultural sampling system 3000 shown in fig. 1. Ultra-fine filtration subsystem 7005 may include a fine filter unit 8080 (see, e.g., fig. 34-35) disclosed herein, including any of the embodiments thereof described further herein.

It is noted that the order of the devices and equipment (e.g., one or more pumps, valves, etc.) shown in fig. 3-4 may be switched and repositioned in the system without affecting the function of the unit. In addition, additional devices and equipment may be added, such as valve devices, pumps, other flow devices, sensors (e.g., pressure, temperature, etc.), to control fluid/slurry flow and to communicate additional operational information to a system controller that may control the operation of the illustrated system. Thus, the system is not limited to the configuration and devices/equipment shown separately.

Digital slurry density measuring device

The density measurement subsystem 7002 includes a digital slurry density measurement device 7010 for obtaining the density of the mixed agricultural sample slurry prepared in the sample preparation chamber of fig. 3-4 (e.g., mixing chamber 8013 of mixing device 8010 in fig. 34). In one embodiment, the density measurement device 7010 may be a digital densitometer of the U-tube oscillator type of any of the examples shown in fig. 5-19 that is used to measure the density of a sample slurry, which in one non-limiting example may be a soil slurry, which will be used hereinafter for convenience. However, it should be appreciated that any type of agricultural sample slurry may be processed in the same system, including soil, vegetation, fertilizer, or others. The density of the slurry is used to determine the amount of diluent (e.g., water) that needs to be added to the soil sample in order to achieve the desired water to soil ratio for chemical analysis of the analyte, as further described herein. The U-shaped oscillator tube 7011 is excited via a frequency emitter or driver 7012 to oscillate the tube at its characteristic natural frequency. In various embodiments, the driver 7012 may be an electromagnetic inductor, a piezoelectric actuator/element, or a mechanical pulse generator, all of which are operable to produce a user-controlled and preprogrammed excitation frequency. A corresponding sensor, such as a receiver or pickup 7013, is provided that is configured to detect and obtain a vibration measurement of the oscillator tube when excited. The pickup may be an electromagnetic, inductive, piezoelectric receiver/element, optical or other commercially available sensor capable of detecting and measuring the vibrational frequency response of the oscillator tube 7011 when excited. The impulse or vibration response motion of the excited oscillator tube 7011 is detected by the pick-up 7013, which measures the amplitude of the frequency response, which is highest at natural/resonant or second harmonic frequencies when the tube is empty. Alternatively, the phase difference between the driving frequency and the driven frequency may be used to narrow to the natural frequency.

In operation, the frequency of vibration of the oscillator tube 7011 when excited varies with respect to the density of the slurry, either in one embodiment the slurry is stagnant filled in the oscillator tube for batch mode density measurement, or in another embodiment the slurry flows through the U-tube at a preferably continuous and constant flow rate for continuous density measurement. The digital density measurement device converts the measured oscillation frequency to a density measurement via a digital controller programmed to compare the baseline natural frequency of the empty pipe to the frequency of the slurry filled pipe.

The frequency driver 7012 and pickup 7013 are operably and communicatively coupled to an electronic control circuit that includes a microprocessor-based densitometer processor or controller 7016-2 that is mounted to a circuit control board 7016 that is supported from a base 7014. The controller 7016-2 is configured to communicate a pulse excitation frequency to the oscillator tube 7011 via the driver 7012 and to measure the resulting changes in the resonant frequency and phase of the excited oscillator tube. The digital density measurement device 7010 converts the measured oscillation frequency into a density measurement via a controller that is preprogrammed and configured with operating software or instructions to perform the measurements and density determinations. The controller 7016-2 may be provided and configured with all the usual auxiliary devices and accessories similar to any of the controllers that have been described previously herein and necessary to provide a fully functional programmable electronic controller. Accordingly, these details of the densitometer controller 7016-2 will not be described in further detail for the sake of brevity.

Fig. 5 to 14 show a density measurement device 7010 having an oscillator tube according to a first embodiment. The density measurement device 7010 also includes a base 7014, a plurality of spacers 7015, a tube mounting block 7017, a flow connection manifold 7018, at least one or a pair of permanent magnets 7025, an electronic circuit control board 7016, and an electrical communication interface unit 7016-1 configured for both power supply of the board and a communication interface with a system controller 2820. The base 7014 is configured for mounting the density measurement device on a flat horizontal support surface, a vertical support surface, or a support surface arranged at any angle between horizontal and vertical. Thus, any suitable corresponding mounting orientation of the base may be used as desired. The mounting orientation of the pedestal may be determined by the intended oscillation direction of the oscillator tube 7011, taking into account the gravity acting on the slurry-laden oscillator tube. It is often advantageous to install all slurry channels in the oscillator tube in such a way that the highest percentage of horizontal channels is achieved as possible, so that any settling of particles occurs perpendicular to the flow channels rather than in-line therewith. In one embodiment as shown, the shape of the base 7019 may be substantially planar and rectangular; however, other polygonal and non-polygonal shaped bases may be used. The base may optionally include a plurality of mounting holes 7019 to facilitate mounting of the base to a support surface using various fasteners (not shown). The base 7019 defines a longitudinal centerline CA of the density measurement device 7010 that is aligned with the length of the oscillator tube 7011 (parallel to the parallel legs of the tube as shown). In other words, the length of the oscillator tube extends along the centre line CA. In one embodiment, the centerline CA and flow channels within the oscillator tube 7011 may be horizontal as shown, such that any settling that occurs is perpendicular to the flow through the channels rather than collinear with the flow. In other embodiments, at least a majority of the flow channels within the oscillator tube may be horizontally oriented.

The spacer 7015 may be elongated in structure and space the control board 7016 from the base 7014 such that the oscillator tube 7011 can occupy the space 7015-1 created therebetween. Any suitable number of spacers may be used for this purpose. The space is preferably large enough to provide clearance for accommodating movement of the oscillator tube 7011 and other accessories such as the frequency driver 7012 and the pickup 7013. The planar control panel 7016 may preferably be oriented parallel to the base 7014 as shown.

In one embodiment, the frequency driver 7012 and the pickup 7013 may be rigidly mounted to a circuit board 7016, as shown in various figures 5-14. In other possible embodiments as shown in fig. 15-18, the drive and pickup may be rigidly mounted to a separate vertical support 7031 attached to the base 7014. In each case, the drive and pickup are mounted adjacent and proximate to the permanent magnet 7025, but do not contact the permanent magnet. The permanent magnet 7025 generates a static magnetic field (lines of magnetic flux) that interacts with the driver 7012 and the pickup 7013 for exciting the oscillator tube 7011 and measuring its vibration frequency when the oscillator tube is excited.

The tube mounting block 7017 is configured for rigidly mounting the oscillator tube 7011 thereto in a cantilevered fashion. In one embodiment, the oscillator tube 7011 may be a straight U-tube configuration, as shown, with all portions lying in the same horizontal plane. The straight inlet end portion 7011-1 and the straight outlet end portion 7011-2 of the oscillator tube 7011 are mounted to and rigidly supported by the block 7017 (see, e.g., fig. 14) to allow the tube to oscillate similar to a tuning fork when the tube is electrically/electromagnetically excited. The mounting block 7017 includes a pair of through holes 7017-1 that receive end portions 7011-1, 7011-2 of the oscillator tubes for their complete passage therethrough. In one embodiment, the through holes 7017-1 may be parallel. The U-bend portion 7011-3 of the oscillator tube opposite the inlet and outlet end portions and the adjoining tube portion between the U-bend portion and the mounting block 7017 are unsupported and free to oscillate in response to the excitation frequency transmitted by the driver 7012.

The inlet end portion 7011-1 and the outlet end portion 7011-2 of the oscillator tube 7011 protrude through the tube mounting block 7017 beyond the tube mounting block and are each received in a corresponding open through bore or aperture 7018-1 of the flow connection manifold 7018 that is associated with a slurry inlet 7020 and a slurry outlet 7021 that define the connection manifold 7018 (see slurry direction flow arrows in fig. 14). The through bore 7018-1 may have any suitable configuration to retain the end portions 7011-1, 7011-2 of the oscillator tube 7011 in a tight and fluid-tight manner. A suitable fluid seal, such as an O-ring, elastomeric sealant, or the like, may be used to achieve a leak-proof coupling between the oscillator tube and the connection manifold 7018. The connection manifold 7018 abuttingly engages the mounting blocks 7017 to provide a continuous coupling opening therethrough for the inlet and outlet end portions 7011-1, 7011-2 to fully support the end portions of the oscillator tube 7011 (see, e.g., fig. 14). In other possible embodiments contemplated, the connection manifold 7018 may be spaced apart from the mounting block 7017, but is preferably in relatively close proximity to the mounting block 7017.

The mounting block 7017, flow connection manifold 7018, and base 7014 may preferably be made of a suitable metal (e.g., aluminum, steel, etc.) of sufficient weight and thickness to act as a vibration damper such that excitation of the oscillator tube as measured by the density measurement device 7010 is only indicative of the frequency response of the filled oscillator tube 7011 and is not disturbed by any corresponding parasitic resonances that might otherwise be induced in the base or mounting block and flow connection manifold.

In the first oscillator tube embodiment shown in fig. 5-14, the oscillator tube 7011 may have a conventional U-shape as shown and described herein before. The tube may be oriented parallel to the flat top surface of the base 7014. In one non-limiting embodiment, the oscillator tube 7001 may be formed from a non-metallic material. Suitable materials include glass, such as borosilicate glass. However, in other possible embodiments, a metal tube may be used. The permanent magnets 7025 are fixedly and rigidly supported from and mounted to the oscillator tube 7001, such as on opposite lateral sides of the U-shaped tube near the U-shaped curved portions 7011-3, as shown. The U-bend portion is furthest from the cantilever portion of the oscillator tube adjacent the mounting block 7017 and thus experiences the greatest displacement/deflection when excited by the driver 7012, thereby making the tube vibration frequency change readily detectable by the digital densitometer controller 7016-2. This yields maximum sensitivity for frequency deviation measurements of the slurry filled oscillator tube 7011 versus the natural frequency of the empty tube; the deviation or difference in frequency is used by the controller 7016-2 to measure slurry density.

While laboratory digital densitometers with oscillator tubes are commercially available, their stock is not fully compatible for measuring soil slurries or other agricultural materials that differ from other fluids in that different amounts of iron (Fe) may be present in the soil. Iron in the soil slurry creates a problem that interferes with accurate soil slurry density measurements because iron particles in the slurry are attracted to the permanent magnets used in the density measurement device 7010. This causes iron particles to accumulate on the portion of the tube nearest the permanent magnet, thereby biasing the density measurement when the oscillator tube is loaded with soil slurry and excited by the driver 7012 by adversely affecting the resonant frequency of the oscillator tube. Fig. 19A shows such an undesirable situation in which Fe particles are accumulated in the oscillator tube.

To address the foregoing problems in processing slurries of ferrous particles, embodiments of the density measurement device 7010 in accordance with the present disclosure may be modified to include various magnetic isolation features or components configured to magnetically isolate the permanent magnets from the oscillator tube 7011 and the ferrous slurries therein. In the embodiment shown in fig. 5-14, each permanent magnet 7025 may be mounted to the oscillator tube 7011 by a magnetic isolation member that includes a non-magnetic mount 7024 (also schematically shown in fig. 19B and 19C). The standoffs project laterally outward in opposite directions from the lateral sides of the oscillator tube and perpendicular to the longitudinal centerline CA of the density measurement device 7010. The support 7024 is configured to be of a suitable size or length such that the permanent magnets are spaced far enough from the oscillator tube 7011 to prevent the generation of a static magnetic field within the tube of sufficient strength to attract and accumulate iron particles in the soil slurry for the reasons discussed above. The magnetic field may be such that its strength is reduced to such an extent that particles are allowed to move under the influence of the flow force without depositing on the inside of the oscillator tube. As shown in fig. 19B, the magnetic flux lines (dotted lines) circulating and flowing from the north (N) pole to the south (S) pole of the permanent magnet 7025 do not reach the oscillator tube 7011. The magnet support 7024 avoids the iron build-up problem illustrated in fig. 19A caused by the direct mounting of the permanent magnets 7025 to the oscillator tube 7011.

In one embodiment where the oscillator tube 7011 is formed of non-metallic and non-magnetic materials (e.g., glass or plastic), the support 7024 may be integrally formed as a one-piece, unitary structural portion of the tube. In other embodiments, the support to which the permanent magnets are mounted may be a separate discrete element that is fixedly coupled to the oscillator tube 7011, such as by an adhesive, a clamp, or other suitable coupling mechanical method. In the case of providing a metallic oscillator tube, the support 7024 is formed of a non-metallic material (e.g., plastic or glass) that is attached or adhered to the oscillator tube by suitable means (e.g., adhesive, clamps, brackets, etc.).

Other possible arrangements for mounting the permanent magnets 7025 to the oscillator tube 7011 and magnetic isolation members may be used that shield or direct the lines of magnetic flux generated by the magnets away from the tube. For example, fig. 19D shows a permanent magnet assembly comprising a magnetic isolation member comprising a metallic magnetic shield 7030 interspersed between the permanent magnets and the oscillator tube to direct magnetic flux lines (dashed lines) away from the oscillator tube. In the illustrated embodiment, the shielding member 7030 is configured as a flat metal plate. Fig. 19E shows a U-shaped or cup-shaped shield member 7030 that functions similarly to fig. 19D. Any suitable shape of metallic magnetic shield may be used as long as the magnetic flux lines are redirected so as not to reach and penetrate the oscillator tube 7011.

Fig. 19F shows that the direction of excitation of the oscillator tube 7011 via placement of the frequency driver 7012 and the pickup 7013 may be in the most stiff direction (e.g., left/right indicated by the tube oscillating motion arrow) or in the least stiff and most flexible direction (e.g., up/down) for a horizontally oriented tube. This will significantly affect the natural frequency of the oscillator tube, which forms a baseline that is compared to the excited tube filled with slurry to determine slurry density (weight). The stiffer the excitation/movement direction of the tube side-to-side, the higher its natural frequency, while the more flexible it is in the up-down direction, the lower its natural frequency. Any orientation or different angular orientation of the oscillator tube may be used. In some embodiments, it is further advantageous to make the tube significantly stiffer in the direction of gravity (i.e., the vertical direction) than in the loading/excitation direction (i.e., the horizontal direction indicated by the tube oscillating motion arrow), as shown in fig. 318B, to help reduce system noise that can interfere with density measurement accuracy.

The density measurement device 7010 operates in a conventional manner known in the art for such U-tube densitometers to obtain density measurements from soil slurry. The slurry density measurements are communicated to a control system 2800 (programmable controller 2820) that is operably coupled to a density measurement device 7010 (see, e.g., density measurement subsystem 7002 in fig. 3, 4, or 35). The controller uses the measurements to automatically determine how much water (diluent) needs to be added to the slurry to achieve a preprogrammed target water to soil ratio or other agricultural sample material ratio depending on the type of material to be sampled and analyzed.

An exemplary method/process for preparing agricultural sample slurries will now be described using slurry density measurements made using density measurement device 7010 (densitometer) and a preprogrammed closed loop control scheme implemented by controller 2820 of control system 2800 via suitable programmed instructions/control logic. For ease of description, this example will use soil as a sample, but is not limited thereto, and may be used with other agricultural sample materials (e.g., plants, fertilizers, etc.). Depending on the environmental conditions and soil type of the farmland, the soil slurry will be diluted to achieve consistent density readings, given any amount of soil in the collected samples and any associated soil moisture content, thereby ensuring repeatable analysis results.

Fig. 31-33 are graphs showing the amount of diluent (e.g., water) added to the slurry versus the slurry density, which the controller 2820 uses to determine the amount of diluent required to reach the preprogrammed target water to soil ratio. The target water to soil ratio may be preprogrammed into the controller in the form of a target slurry density, which may be directly equivalent to the ratio, since the density of the diluent used is a known fixed factor. In the case where the known density of the diluent used (e.g., water density of 0.998 g/mL) is also preprogrammed into the controller, as more and more diluent is added to the slurry in the system, the slurry mixture will eventually approach the density of the density diluent, but will never reverse and become less than that value. Thus, the relationship and curves shown in graph 330 are generated by controller 2820 and used to achieve a target slurry density (water to soil ratio). The dilution amount (Y axis) is the total volume added to achieve dilution. In the case of different amounts of soil, soil moisture and addition of water (diluent) to form the initial slurry mixture, the slope of the curve will change but will remain the same overall shape.

Referring additionally to fig. 3-4, the collected raw soil sample and a known amount of water are initially mixed for a first time as indicated in the mixing device 100 to prepare a slurry. Once the soil slurry has been mixed and homogenized in the mixer, a first density measurement is sensed by the densitometer and transmitted to the controller 2820. A point 7090A on the curve in fig. 31 indicates the first density measurement taken.

To more accurately determine the dilution amount versus slurry density in real time, a known amount of water is metered by the controller 2820 and added to the mixing apparatus 100 (e.g., 20 mL) via the operatively coupled water control valve 7091 in a subsequent step, and the resulting slurry density is measured a second time. A point 7090B on the curve in fig. 32 indicates the second measurement taken. Then, a linear relationship (represented on the curve by a solid line between the two points) can be generated by the controller between the two slurry density points 7090A and 7090B taken. For a given preprogrammed target slurry density (land water ratio), the target density may then be entered into the relationship, and the output calculated by controller 2820 is a first estimate of the total amount of diluent (e.g., water) required to achieve the target density.

Next, the controller 2820 meters and adds an estimated amount of additional diluent (e.g., water) required to reach the target slurry density to the slurry mixture mixed with the slurry by the mixing device 100. The resulting slurry density was measured a third time. Point 7090C on the curve in fig. 33 indicates the third measurement taken, which continues to add data points to the linear relationship (see longer solid line on the curve). Once the controller has obtained at least three slurry density measurements and corresponding points on the slurry density curve, the controller may perform polynomial regression on the data, thereby providing a more accurate curve fit. Based on and using the preprogrammed target density, the controller 2820 then calculates the total amount of diluent required based on the updated curve and adds that amount to the slurry to achieve the target slurry density. The process may be iterated to improve the accuracy of the regression model or until the actual density is sufficiently close to the target density.

Fig. 14-18 depict an alternative second embodiment of a cantilevered U-shaped oscillator tube 7032 for use with a density measurement device 7010, in contrast to the straight U-shaped oscillator tube 7011 previously described herein. In this embodiment, the oscillator tube 7032 has a turn-back U-tube shape with a 180 degree main U-bend 7032-3 extending rearward on top of the straight inlet end portion 7032-1 and the straight outlet end portion 7032-2 of the oscillator tube 7032, which is secured to the tube mounting block 7017 and the flow connection manifold 7018. This is created by adding two additional 180 degree minor U-bends 7032-4 between the straight end portions 7032-1, 7032-2 and the major U-bends 7032-3. One secondary U-bend 7032-4 is disposed in the slurry inlet leg of the oscillator tube upstream of the primary U-bend 7032-3, while the other secondary U-bend 7032-4 is disposed in the slurry outlet leg of the oscillator tube downstream of the primary U-bend, as shown. In this turn-back oscillator tube embodiment, standoffs 7024 are disposed on the secondary U-shaped bend and project laterally outward in opposite lateral directions to hold the permanent magnets 7025 in spaced relationship to the oscillator tube. The frequency driver 7012 and pickup 7013 are supported from the base 7014 by a separate vertical support 7031 located near the permanent magnet to excite the oscillator tube 7032, as previously described herein.

In the turn-back oscillator tube 7032, the slurry flow follows the path indicated by the directional flow arrow in fig. 17. By the primary and secondary U-bends 7032-3 and 7032-4, the slurry stream moves twice in a first direction parallel to the centerline axis CA and also twice in an opposite direction parallel to the centerline axis CA. The primary U-shaped bend 7032-3 is oriented horizontally and the secondary U-shaped bend 7032-4 is oriented vertically. In this design, the centerline CA and a majority of the flow channels within the oscillator tube 7011 may remain horizontal in the orientation shown, such that any settling that occurs is perpendicular to the flow through the channels rather than collinear with the flow.

In contrast to the first U-shaped oscillator tube 7011 of fig. 5 described above first, the triple-curved, folded-back oscillator tube 7032 design is advantageous because the vibratory displacement is mirrored between the left and right sides of the tube (e.g., as the tube oscillates, the vertical bends 7032-4 bend toward each other and then away from each other). Thus, there are always equal and opposite forces that cancel each other out during vibration, so that external effects on the mass, stiffness or damping of the base and other components do not affect the vibration. Previous straight U-tube oscillator designs have resulted in some degree of vibration in the overall system because they do not balance the oscillation and easily propagate the vibration into the base. Since the entire system vibrates, any external effects on the mass, stiffness, or damping of the entire system can artificially alter the natural frequency, thereby adversely affecting accuracy to some extent. Nevertheless, a straight U-tube oscillator is acceptable without undue external influence.

The rest of the density measurement device 7010 setup and components are essentially the same as the embodiment utilizing the oscillator tube 7011 and will not be described in detail here for the sake of brevity.

In some embodiments, a single device combining the aforementioned functions of both the frequency transmitter or driver 7012 and the receiver or pickup 7013 may be provided instead of separate units. As one non-limiting example, such a device may be an ultrasonic transducer. For a combined single driver-pickup device 7012/7013, the device can be activated to excite the oscillator tube 7011, stop the oscillator tube from oscillating several times, and then re-activate the oscillator tube to measure the resulting oscillation frequency response of the tube. In a combined design, only a single permanent magnet 7025 located near the drive/pickup is required.

Fine filter

The fine filter unit of the fine filtration subsystem 7003 shown in fig. 3 and 4 will now be further described. In testing, the inventors have found that "fine" filtering (e.g., 0.010 inch/0.254 millimeter) directly from the mixing device can in some cases have a detrimental and significant impact on the ability to achieve a consistent water to soil ratio (e.g., 3:1) across all types of soil that may be encountered, sampled and tested. Thus, it is beneficial to know and measure the density of the mixed raw soil sample slurry from the mixing device 100 prior to performing fine filtration. Accordingly, a preferred but non-limiting embodiment of the disclosed agricultural sample analysis system 7000 includes a coarse filter 146 upstream of the density measurement device 7010 and a fine filter 7050 or 7060 downstream of the density measurement device; each of which is described in more detail below. Two different exemplary configurations of agricultural sample analysis systems including such two-stage slurry filtration are disclosed; one configuration is shown in fig. 4 with slurry recirculation from the fine filter unit back to the mixing device 100 and one configuration is shown in fig. 3 without recirculation, discussed further herein.

The agricultural sample analysis system utilizes a first coarse filter 146 having a very coarse screen (e.g., a maximum particle size channel of about 0.04 inch to 0.08 inch/1 millimeter to 2 millimeters in one possible embodiment) to initially screen and filter out larger sized stones, crushed stones, and aggregates from the slurry to avoid clogging/plugging the flow conduit (tubing) lines upstream of the microfluidic processing tray 4000 while still allowing accurate density measurements to be performed in the density measurement device 7010. In one embodiment as previously described herein, coarse filter 146 may be incorporated into mixing apparatus 100 or may be a separate downstream unit. This coarse filtration is followed by fine filtration in a fine filter unit 7050 or 7060 having fine screening (e.g., in one possible embodiment, a maximum particle size channel of less than 0.04 inch/1 millimeter, such as about 0.010 inch/0.25 millimeter) to allow the agricultural slurry sample to pass through downstream slurry processing and chamber analysis flow networks (e.g., components of microfluidic flow networks and microfluidic processing trays) without causing flow blockage/clogging. An example of such a microfluidic processing disk flow network is disclosed in commonly owned International publication No. WO 2020/012369. For soil, these very small particles passing through the fine filter unit constitute the vast majority of the nutrient content of the soil, so it is acceptable to use the fine filtered slurry for final chemical analysis in the system. It is worth noting that the fine filtration step and filter units 7050, 7060 can be used and adapted to slurries composed of other agricultural materials to be sampled (e.g., vegetation, fertilizer, etc.), and thus are not limited to soil slurries only.

Fig. 21-24 illustrate a first embodiment of a fine filter unit 7050 that may be used with any of the soil slurry preparation and analysis systems illustrated in fig. 3-4. The fine filter unit 7050 is configured for use with the slurry recirculation arrangement of fig. 4 (which includes a closed recirculation flow loop 7059), particularly as shown between the fine filter unit 7050 (or 7060) and the mixing apparatus 100.

The filter unit 7050 includes a longitudinal axis LA, a pre-filtration slurry inlet nozzle 7051, a pre-filtration slurry outlet nozzle 7052, a plurality of filtrate outlets 7053 (post-filtration), an internal pre-filtration slurry chamber 7057, an internal filtrate chamber 7054, and one or more filter members, such as a screen 7055, disposed between the chambers. In one embodiment, the screen 7055 may be arcuate and positioned on top of the slurry chamber 7057 as best shown in fig. 24. Any number of screens may be provided. A pair of annular seals 7056 fluidly seal the inlet and outlet nozzles 7051, 7052 to the body of the filter unit to allow for initial placement of the filter screen 7055 inside the filter unit prior to securing the inlet and outlet nozzles to the body. The body may be block-shaped, cylindrical or other shape. The nozzle may be disengaged from the central main filter body to gain access to the interior of the filter unit and to initially install the screen or to periodically replace the screen. Threaded fasteners 7058 or other suitable coupling means may be used to couple the inlet nozzle and the outlet nozzle to opposite ends of the body. The slurry inlet nozzle 7051 and slurry outlet nozzle 7052 may have any suitable configuration in order to accept any suitable type of tubing connector to fluidly couple the system slurry tubing 7088 to the filter 7050. One non-limiting example of a tubing connector that may be used is a commercially available John Guest plastic half box connector. Other tubular connectors may be used. Any suitable non-metallic (e.g., plastic) or metallic material may be used to construct the filter unit 7050 including the screen 7055. In one embodiment, the body of the filter unit may be plastic and the screen 7055 may be metallic, such as a mesh net defining a mesh opening.

In operation and with respect to fig. 4, a slurry flow path through the fine filter unit 7050 is described, with unfiltered slurry flowing from the coarse filter 146 sequentially (upstream to downstream) through the density measurement device 7010 and into the fine filter unit through the inlet nozzle 7051. The slurry flows axially and linearly through the pre-filtration slurry chamber 7057 and then exits the filter back to the mixing device 100 through the outlet nozzle 7052 (see, e.g., "sample preparation chamber" in fig. 4). A slurry recirculation pump 7080 may be provided to fluidly drive the recirculation flow in the closed recirculation flow loop 7059 and return the slurry that has not been finely filtered to the mixing device. Any suitable type of slurry pump may be used. In some embodiments, the recirculation pump may be omitted if the main slurry pump 7081 provides sufficient hydrodynamic force to drive the slurry flow through the entire closed recirculation flow loop 7059. The system continuously recirculates the coarsely filtered slurry back to the main blending chamber of the mixer for a period of time. Such recirculation may advantageously help to obtain a uniform slurry mixture for analysis more quickly than if the mixer were used alone by continuously recirculating slurry through the mixer and coarse filter in a closed recirculation flow loop 7059. During density measurement, the previously described control system 2800 (including programmable controller 2820) automatically meters water and adds water to the mixing device 100 in accordance with the system monitoring slurry density measured by the density measurement device 7010, which is operatively coupled to the controller in order to achieve a preprogrammed water-to-soil ratio. By such continuous slurry recirculation, the slurry may be better mixed.

Once a coarse filtered, homogenous slurry having the desired water to soil ratio is obtained, a small portion of the recirculated slurry stream may be bypassed and extracted from the fine filter unit 7050 for initial processing and subsequent chemical analysis in the analyte extraction subsystem 7004 (see, e.g., fig. 4). The extracted slurry flows transversely through the filter screen 7055 into the filtrate chamber 7054 and then outwardly through the filtrate outlet 7053 to the analyte extraction subsystem. The flow of extracted slurry may be controlled if desired by a suitable control valve 7070, the position of which may be varied between an open full flow, a closed no flow and a throttled partially open flow. The valve 7070 may be operated manually or automatically by the controller 2820, opened at an appropriate time once a uniform slurry having a desired water to soil ratio has been achieved, or otherwise preprogrammed. Additional valves may also be used to open the water flow in order to back flush the filter during the cleaning cycle in preparation for the next sample.

Although two filtrate outlets 7053 are shown in fig. 319-323, other embodiments may have more than two filtrate outlets or less (i.e., one outlet). Each filtrate outlet 7053 is fluidly coupled to and supplies fine filtered slurry (filtrate) to a separate one of a dedicated soil sample slurry processing and analysis chain or system, such as disclosed in commonly owned international publication No. wo 2020/012369; each chain is fluidly isolated from the other chains and configured for quantifying in parallel the concentration of different analytes of interest (e.g., plant nutrients such as nitrogen, phosphorus, potassium, etc.).

It is noted that the term "pre-filtration" as used above refers only to the fact that the soil slurry has not been filtered relative to the presently described fine filter unit 7050. However, the slurry may have undergone prior filtration or screening upstream, such as in the coarse filter 146 seen in fig. 3-4. Thus, the slurry may be filtered before reaching the downstream fine filter unit 7050.

The fine filter unit 7050 is configured to eliminate the passage of soil particles or other particulates in the slurry that cause clogging or otherwise blocking in micro-fluid flow channels/conduits of very small diameter and micro-fluid processing disk flow components (e.g., valves, pumps, and chambers formed within analytical processing wedges of the micro-fluid processing disk described in international publication No. wo 2020/012369). Accordingly, the filter screen 7055 of the fine filter unit 7050 is sized to pass soil particles that are compatible with the microfluidic processing disks and that are smaller in size than the soil particles screened out by the upstream coarse filter 146 associated with the mixing apparatus. The filter screen 7055 has a plurality of openings each configured to remove particles larger than a predetermined size from the slurry to produce a filtrate. In one embodiment, the screen 7055 may be formed from a mesh-like metal net defining mesh openings for filtering the slurry.

Thus, in a preferred embodiment, the first coarse filter 146 of the system is configured to pass slurry having a first maximum particle size, and the second fine filter unit 7050 is configured to pass slurry having a second maximum particle size that is smaller than the first maximum particle size. Further, an ultra-fine filtration subsystem 7005 (which may be incorporated into or associated with the micro-fluid handling disc 4000 or with the soil sampling system 3000) including a third ultra-fine filter 5757 is configured to pass slurry having a third maximum particle size smaller than the first and second maximum particle sizes. As previously described herein, the ultra-fine filter 5757 is a microporous filter that can replace a centrifuge and is configured to produce a clarified filtrate from a soil slurry and extractant mixture that is used as a supernatant for chemical analysis. Thus, the ultra-fine filter 575 outperforms both the coarse and fine filters in terms of minimum maximum passable particle size. As a non-limiting example, representative pore sizes that may be used for the ultra-fine filter 575 are about 0.05 μm to 1.00 μm and include the endpoints. Notably, the above terms "first", "second", "third" are used to connote filter units that the slurry encounters sequentially from upstream to downstream as it passes through the systems shown in fig. 3-4. Thus, as the slurry passes through each filter unit in turn, the maximum slurry particle size becomes increasingly smaller.

In normal filter operation, all flow is directed through the screen and anything that does not pass through the screen stays on the screen and accumulates. This requires draining or back flushing the screen after a period of time to keep it clean and functioning properly for its purpose. This presents a problem if a large amount of particulate material is required to be filtered out, as this can result in a very short period of time for the filter to work properly before the filter needs to be cleaned. For this reason, a new mesh fine filter unit 7050, 7060 was designed, the principle of operation of which is to extract a small amount of soil slurry from the main slurry recirculation flow path as described above for testing, rather than intercept all slurry streams for fine filtration. This advantageously enables the filter to remain clean for a considerably longer period of time, since only a small portion of the slurry stream is extracted and travels through the screen transversely to the main direction of flow through the filter unit. In addition, the primary slurry flow path, which is preferably oriented parallel to the plane occupied by the screen 7055, continuously scrubs and cleans the filter screen 7055 by the shearing action of the flow (see, e.g., fig. 24) to prevent particles from collecting on the screen. It is also worth noting that the fine filter units 7050 and 7060 advantageously avoid interior regions with low pressure or flow where particulates may collect. It is also desirable to avoid the orientation of the inner surface of the filter where particulates would accumulate due to gravity. Thus, embodiments of the fine filter units 7050, 7060 may preferably be oriented such that the filter screens 7055, 7065 are above the main flow and junction points, respectively, and preferably in a direction transverse to the main flow path of the slurry through the filter body, at which junction point the bypass slurry flow is drawn off for chemical analysis (see, e.g., fig. 24 and 29).

Fig. 25 to 29 show a second embodiment of the fine filter unit 7060 described above. The fine filter unit 7060 includes a plurality of optionally replaceable filter screen assemblies or units 7068. In this embodiment, by contrast to the fine filter unit 7050, the filter screen unit can be removed and replaced without disrupting the end fluid connection with the system tubing/piping, thereby greatly facilitating periodic replacement of the screen over time. The filter unit 7050 has an internally mounted screen 7055 that can be accessed by removing the slurry inlet nozzle 7051 and outlet nozzle 7052 as previously described herein. In some embodiments, the filter screen unit 7068 can be configured to be disposable such that a new screen unit can be interchanged with a used plugged screen unit when desired.

The fine filter unit 7060 has an axially elongated body defining a longitudinal axis LA, a pre-filter slurry inlet 7061, a pre-filter slurry recirculation outlet 7062, a plurality of filtrate outlets 7063 (post-filter), an internal pre-filter primary slurry chamber 7067 in fluid communication with the inlet and outlet, and a plurality of filter screen units 7068, each comprising a filter member, such as a screen 7065, disposed between the chamber 7067 and one of the filtrate outlets 7063. The inlet 7061 and outlet 7062 may preferably be located at opposite ends of the fine filter unit body at each end of the chamber 7067, allowing the main slurry chamber to define a slurry distribution manifold in fluid communication with each filtrate outlet 7063. In some embodiments, the screen 7065 may be convexly curved and dome-shaped (best shown in fig. 29). The main slurry chamber 7067 extends axially below the screen unit 7068 between the inlet 7061 and the outlet 7062. Although the fine filter unit 7060 is convex, it may be used in the orientation shown such that the portion of the screen 7065 exposed to the slurry in the main slurry chamber 7067 may be considered to be oriented substantially horizontally and parallel to the longitudinal axis LA and the axial flow of slurry through the main slurry chamber screen. When the fine filter unit 7060 is used in a preferred horizontal position, the flow through the screen is further in an upward direction (transverse to the longitudinal axis LA and axial slurry flow in the chamber). This combination is advantageous for both: (1) As the slurry flows through the screens in the slurry chamber 7067, the screens 7065 are scrubbed and cleaned, preventing slurry particles from accumulating on the screens until filtrate is extracted, and (2) counteracting the effects of gravity for accumulating particulates on the screens, as the slurry enters the screens from the bottom, thereby retaining the particles under the screens until filtrate extraction occurs.

The fine filter units 7060 are axially elongated such that the screen units 7068 can be arranged in a single longitudinal array or row as shown such that the primary slurry chambers 7067 are linearly straight to avoid creating internal dead flow and low pressure areas in the slurry flow path that can accumulate particulates in the slurry.

In one embodiment, an annular seal 7066, which may be an elastomeric gasket, may be incorporated directly into each filter screen unit 7068 as part of an assembly to fluidly seal the screen unit to the body of the filter unit. In one embodiment, the screen unit 7068 may have a cup-shaped configuration (best shown in fig. 26) wherein a convexly curved dome-shaped screen 7065 protrudes outwardly/downwardly from one side of the seal 7066 into the main slurry chamber 7067. Each screen unit 7068 is received in a complementarily configured upwardly open receptacle 7069 formed in the body of the filter unit 7060, which is in fluid communication with the main slurry chamber 7067 of the filter unit. The screen retainer 7064 may be removably coupled to the filter unit body and at least partially received in each receptacle to retain each screen unit, as best shown in fig. 29. The body may be massive, cylindrical or otherwise shaped. In one embodiment, the filtrate outlet 7063 may be an integral, unitary structural part of the screen retainer 7064, and in some embodiments may terminate in conventional tubing barbs as shown, to facilitate coupling to the flow conduit tubing of the system. Other types of fluid end connections may be used. The filtrate outlet 7063 extends completely through the holder from top to bottom (segmentation of fig. 328). In some embodiments, the retainer 7064 can have a generally stepped cylindrical configuration. Threaded fasteners 7058 or other suitable coupling devices can be used to removably couple the retainer 7064 to the body of the filter unit. The retainer 7064 captures the filter screen unit 7068 in the receptacle 7069. Any suitable non-metallic material (e.g., plastic) or metallic material may be used to construct the filter unit 7060 including the screen 7065. In one embodiment, the body of the filter unit may be plastic and the screen 7065 may be metallic.

Similar to the filter unit 7050 and the screen 7055, the screen unit 7068 has screens 7065, each of which is configured to remove particles larger than a predetermined size from the slurry to produce filtrate. Accordingly, the filter screen 7065 has a plurality of openings, each of which is configured to pass slurry having a predetermined maximum particle size. In one embodiment, the screen 7065 may be formed from a mesh-like metal net defining mesh openings for filtering the slurry. Other embodiments of the screen 7065 or 7055 may use a polymer mesh. In other possible embodiments, other types of filter media may be used to perform the desired sizing.

An exemplary process for exchanging the filter screen unit 7068 includes removing the threaded fasteners 7058, withdrawing the retainer 7064 laterally from each receptacle 7069 from the longitudinal axis LA of the filter unit body, withdrawing the filter screen unit laterally, inserting a new screen unit into each receptacle laterally from the longitudinal axis LA, reinserting the retainer into the receptacle, and reinstalling the fasteners.

An overview of a non-limiting method for preparing agricultural sample slurries using slurry recirculation and dual filtration generally includes the steps of: mixing an agricultural sample with water in a mixing device to prepare a slurry; filtering the slurry for the first time; measuring the density of the slurry; recycling the slurry back to the mixing device; and extracting a portion of the recycled slurry through a secondary fine filter to obtain a final filtrate. Filtering the slurry a first time includes passing a slurry of particles having a first maximum particle size, and filtering the slurry a second time includes passing a slurry of particles having a second maximum particle size smaller than the first maximum particle size. The final filtrate then flows into any of the agricultural sample analysis systems disclosed herein that are configured to further process and measure the analytes in the slurry.

Notably, the fine filter units 7050 and 7060 can be used with the agricultural sample analysis system of fig. 3 without slurry recirculation by simply closing the respective recirculation outlet nozzles via a plug or via a closing valve fluidly coupled to the outlet nozzles. Alternatively, the slurry may flow to waste after passing through a fine filter. In this case, it will be necessary to extract filtrate from the slurry while it is flowing through the filter.

Instead of the pump recirculation system of fig. 4, fig. 30 is a schematic diagram showing an alternative equipment layout and method for recirculating the coarsely filtered slurry through the fine filter unit 7050 or 7060 using pressurized air instead. The two blending chambers are fluidly coupled to the inlet and outlet of the fine filter unit 7050 or 7060 as shown by a flow conduit network arrangement, which may be a pipe or tube 7086 as shown. At least one of the blending chambers may be provided by the mixing device 100A for initially preparing water and soil slurry. The other blending chamber may be an additional mixing device 100B or alternatively simply an empty pressure vessel. As shown, four slurry valves 7085A, 7085B, 7085C, and 7085D are fluidly arranged between the fine filter unit and each of the chambers for controlling the directing of slurry during blending. In operation, if slurry is first prepared in mixing device 100A (sample preparation chamber # 1), valves 7085B and 7085C are opened, and valves 7085A and 7085D are closed. Mixing device 100A is pressurized with air from a valved pressurized air source 7086, which forces the slurry through density measurement device 7010 and fine filter unit 7050 or 7060 to mixing device 100B. Then, the valves 7085B and 7085C are closed, and the valves 7085A and 7085D are opened. The mixing device 100B is then pressurized, causing the slurry to flow in the opposite direction through the fine filter unit 7050 or 7060 and the density measurement device 7010 back to the mixing device 100A. This sequential cycle is repeated multiple times to continue slurry blending. The valve arrangement and the pressurized air source may be operatively coupled to and controlled by a system controller 2820 pressure, which may be programmed to cause this reciprocating back and forth flow to occur very rapidly. Slurry density can be measured continuously each time slurry flows through the densitometer. Once the slurry is thoroughly blended as desired, the filtrate outlet from the fine filter unit is opened to direct the filtered slurry to the extraction subsystem 7004 shown in fig. 4 for processing and chemical analysis. In some embodiments, a single pressurized air source may be used for each mixing chamber instead of separate sources. In another embodiment, the second chamber may be mounted directly above the first sample preparation chamber with a valve between the two chambers. Instead of pressurizing the second chamber, gravity will allow the slurry to flow back down into the first chamber.

Sizing of system slurry flow conduits

The Inner Diameter (ID) of the slurry flow conduit (e.g., slurry tubing 7088 shown in fig. 3-4) is critical to the proper operation of the agricultural sample analysis system 7000 without clogging the tubing. The likelihood of clogging increases when slurry with large particles is moved through the small tubes. For almost laminar flow, the velocity at the wall is close to zero, which exacerbates the problem. For small tubes, this problem becomes significant due to the high friction on the slurry. If these frictional forces become too great, particles will fall out of the flow and accumulate in the pipe, resulting in a flow stop. In addition, large particles may wedge into small tubes with other large particles and cause clogging and flow stopping. However, having very large pipes is problematic because it is difficult to have sufficient flow to keep the particles suspended to prevent the soil particles from settling.

The inventors have found that the inner diameter of the slurry tube 7088 and the passageway should be designed such that the cross-sectional inner diameter is at a minimum twice the maximum particle size in the slurry. That is, as an example, if the particles are screened by the coarse filter 146 or the fine filter unit 7050 or 7060 to a size (e.g., diameter) of 2mm, the ID of the tube should be not less than a diameter of 4 mm. In contrast, the inner diameters of the tube and the channel should be designed such that the cross-sectional inner diameter is at most ten times the maximum particle size (e.g., diameter). That is, as an example, if the particles are screened to a size of 2mm, the ID of the tube should not be greater than 20mm in diameter. Thus, the preferred inner diameter of the slurry tube 7088 has a critical range between at least two times the maximum particle size/diameter and no more than ten times the maximum particle size/diameter.

In some embodiments, the tubing material used may preferably be flexible and formed from a fluoropolymer, such as, but not limited to, FEP (fluorinated ethylene propylene) in one non-limiting example. Other fluoropolymers are, for example, PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene) and PFA (perfluoroalkoxy polymer resin). The dynamic coefficient of friction (DCOF) associated with these fluoropolymers also affects the preferred range of pipe inner diameters described above, as the pipe material creates frictional resistance to slurry flow. FEP, PTFE, ETFE and PFA each have a DCOF in the range of between about 0.02 to 0.4 and inclusive, as measured according to ASTM D1894 test protocol. Thus, in some embodiments, the tubular material for the sizing tubular 7088 associated with the critical tubular inner diameter range described above preferably also has a DCOF in the range between about 0.02 and about 0.4 inclusive and more specifically in the range between about 0.08 and 0.3 inclusive associated with FEP. Tests performed by the inventors confirm that the use of FEP tubulars within the critical tubular inner diameter range avoids the slurry flow blockage problem described above. In other possible embodiments, nylon may be used.

Agricultural sample slurry preparation system with modified slurry recirculation

Fig. 34-70 illustrate various aspects of a modified agricultural slurry preparation system 8000 and its various components of an agricultural sample analysis system 7000. System 8000 is one non-limiting embodiment of a sample preparation subsystem 3002 that is shown in FIG. 1. The system 8000 is configured and operable to prepare a water-based slurry comprising an agricultural sample material (e.g., solids) having a desired target slurry water to solids ratio suitable for further chemical analysis and quantification of analyte levels (e.g., plant nutrients or others) in the sample. In one embodiment, the system may include a closed slurry recirculation flow loop 8002 including a density measurement device operable to measure the density of the slurry being prepared. The recirculation flow loop can be isolated from other portions of the slurry system to form a closed slurry flow path or loop for use in connection with measuring the density of agricultural slurry, as further described herein. This loop allows slurry to be recycled in a closed recycling system while gradually adding water (diluent) to achieve a target water to solids (agricultural) ratio. In one embodiment, the agricultural sample material may be soil comprising a particulate or solid portion of a water-based slurry; however, any other agricultural material or solid previously described herein may be used with the slurry preparation system 8000.

Fig. 34 is a simplified schematic setup diagram of an agricultural slurry preparation system 8000 shown in the associated high-level block flow diagram of fig. 35.

Referring first to the foregoing fig. 34-35, an agricultural slurry preparation system 8000 generally includes a mixing apparatus 8010, a coarse filter unit 8020, and a closed slurry recirculation flow loop 8002 that are fluidly coupled and in communication. The mixing device 8010 may be fluidly coupled to the slurry recirculation flow loop 8002 via a flow conduit 8001. In one embodiment, the slurry may flow from the mixing device by gravity, pressurized air force, or be pumped to a recirculation flow loop. One non-limiting arrangement uses gravity to avoid the cost and maintenance of the pump. Other embodiments may rely on gravity assisted by pressurized air.

The flow conduit 8001 may be formed of tubing, hoses, and/or piping having only suitable dimensions (i.e., length and diameter) and materials (e.g., metallic and/or non-metallic materials (e.g., plastic, rubber, etc.)) or combinations of dimensions and materials. Combinations of these materials and dimensions may also be used as desired. The flow conduit 8001 may be flexible, semi-rigid, and/or rigid in structure. In one embodiment, plastic tubing may be used for at least some of the flow conduits. The coarse filter unit 8020 may be fluidly coupled to each of the recirculation flow loop 8002 and the mixing device 8010 via a flow conduit 8001 and located in a flow path between the recirculation flow loop and the mixing device.

The inventors have found that separating the initial bulk agricultural slurry preparation function via the mixing device 8010 from the function of maintaining the slurry in a uniformly mixed state for measuring the slurry density results in a more accurate density determination. Thus, as described further herein, slurry recirculation flow loop 8002 includes a separate dedicated stirring device 8030 for this purpose.

Slurry mixing device

The mixing device 8010 for preparing an initial agricultural slurry by mixing collected agricultural solids with water generally includes a sealable hollow body defining a mixing chamber 8013, a sample inlet 8011, a water inlet 8012, and a rotatable vane mechanism 8014 configured and operable for mixing agricultural sample material and water added to the mixing chamber 8013. An agricultural sample consisting of bulk or raw collected agricultural material (e.g., soil, fertilizer, vegetation, or other agricultural material) may be added to mixing device 8004 via sample inlet 8011. Water may be added via water inlet 8012.

The vane mechanism 8014 generally includes a vane assembly 8015 and a drive unit, such as an electric drive motor 8016 coupled to an impeller or drive shaft 8017 of the vane assembly. One or more sets of spaced apart impellers or blades 8016 may be mounted to the drive shaft 8017, the one or more sets of impellers or blades being rotatable via operation of the motor 8016 at one or more constant predetermined speeds or variable speeds. Any suitable commercially available fixed or variable speed electric motor may be used in the present application.

In one embodiment, pressurized air from an available pressurized air source 8005 may be used to drive unfiltered slurry from mixing apparatus 8010 to coarse filter unit 8020 via flow conduit 8001. The shutoff valve 8003 in the slurry discharge flow conduit 8001 from the mixing device 8010 may be closed. A pressurized air line 8006 may be coupled to the flow conduit 8001 between the shutoff valve and the filter unit 8020. In other possible embodiments, slurry may be pumped from the mixing device 8010 to the filter unit 8020.

Coarse filter unit

Fig. 36-43 show additional images of the coarse filter unit 8020 alone and in more detail. The coarse filter unit 8020 is configured and operable to remove undesirable oversized or larger particles that may remain entrained in the agricultural sample slurry after the slurry is prepared in the mixing device 8010. Such oversized particles may include hardened accumulations or pieces of agricultural solids or foreign debris/foreign matter collected with the agricultural sample. For soil samples, such oversized particles may include small stones or pebbles from the field, foreign matter in the soil (e.g., parts of agricultural equipment, tools, fasteners), or hard clumps of crop residues.

The coarse filter screen 8021 mounted inside the filter unit 8020 has a mesh size or openings selected to prevent such larger than desired or oversized particles from passing through the screen while allowing desired smaller solid particles suspended in the agricultural slurry to pass through to the slurry recirculation flow loop 8002 for further processing as further described herein. Thus, the mesh or mesh size is selected to prevent particles of a predetermined size from passing through the screen 8021, which particles may adversely affect downstream flow components or equipment (e.g., pumps, valve devices, etc.) disclosed herein. Consider the opposite way in which the mesh is selected to allow particles of a predetermined maximum particle size to pass through. In one non-limiting embodiment, the mesh or mesh size of the filter screen 8021 may be about 1/16 inch (0.063 inch) for soil-based slurries, as an example. Slurry particles larger than this size will not pass through the filter screen. Other sized mesh openings may be used for soil slurry or other types of agricultural slurry. In one embodiment, the filter screen 8021 is elongated and can be curved arcuately from side to side for easier passage and drainage of accumulated debris.

In one embodiment, the coarse filter unit 8020 may have a generally Y-shaped body that includes an unfiltered slurry inlet 8022, a filtered slurry (filtrate) outlet 8023, and a waste outlet 8024. In some embodiments, the filter unit 8020 may be formed of plastic; however, other embodiments may use a metal body. In one embodiment, the slurry inlet 8022 may comprise an elastically deformable segmented tube coupling 8022a comprising a plurality of radially deformable elongated fingers 8022b, wherein the longitudinal slits 8022c circumferentially separate the fingers (labeled in fig. 36). The tube coupling 8022a allows the flow tube/hose 8001 (flow conduit) to be inserted inside the coupling rather than outside so that the end of the tube/hose enters the slurry inlet 8022 of the filter unit 8020. This advantageously eliminates any small openings, gaps, or exposed edges in the coupling arrangement where solids or debris in the unfiltered slurry may accumulate and cause clogging. Thus, the unfiltered slurry flow path into the filter unit is internally unobstructed, thereby also avoiding disturbances in the flow. Standard tightenable hose clamps 8022d may be used to compress the fingers 8022b inward and secure the tube/hose 8001 to the tube coupling 8022a (see, e.g., fig. 39). In other embodiments, other types of pipe/hose couplings may be used.

In one embodiment, the filtrate and waste outlet 8024 may be threaded to mount the valve 8003 directly to the body of the coarse filter unit 8020. However, other types of end coupling arrangements may be used.

A filter screen 8021 is fluidly interposed between the slurry inlet 8022 and the filtrate outlet 8023, as best shown in fig. 42. In one embodiment, the screen 8021 may be elongated and curved arcuately from side to side. The screen 8021 may be mounted in a central portion of a Y-shaped body that divides the interior of the filter unit into an upper chamber 8028a (above the concave side of the screen) and a lower chamber 8028b (below the convex side of the screen). The filter unit 8020 is intended for use in a position in which the upper chamber is inclined at an angle downwards relative to a horizontal reference plane H through the filter body (see, e.g., fig. 41). In other embodiments, other locations may be used.

Referring to fig. 41 and 42, in some embodiments, the lower chamber 8028b may have an inclined frustoconical shape, forming a converging cone that tapers downwardly in a direction from the filter screen 8021 toward the filtrate (filtered slurry) outlet 8023. This forms a funnel and concentrates the filtered slurry exiting the filter unit 8020 while providing a large upper portion of the lower chamber adjacent the filter screen for filtering a maximum amount of slurry with a minimum fluid pressure drop.

In some embodiments, the coarse filter unit 8020 may also include a transparent cover 8027 to allow visual inspection of the filter screen 8021 to find an accumulation of debris removed from the slurry stream. Other embodiments may have an opaque cover. Each of the filtrate outlet 8023 and waste outlet 8024 of the filter unit and the unfiltered slurry inlet 8022 is closable/sealable for fluid isolation from other components of the slurry preparation system via the provision of a dedicated valve 8003 associated with each of the outlet and inlet. In some embodiments, one or more of these filter unit valves 8003 may be directly coupled to the filter unit body. In one embodiment, a pneumatically actuated pinch valve with an elastically deformable diaphragm or bladder (sometimes referred to as a sleeve) may be used, which is ideal for treating slurries with entrained/suspended particulate matter. Pinch valve type valve 8003 includes a pressurized air port 8003a for pressurizing the valve, which collapses the bladder to close the valve. Due to the elastic memory of the bladder, releasing the air pressure returns the bladder to its original, resiliently biased open state. Such pinch valves are commercially available and their operation is known in the art and need not be described in further detail. However, other types of commercially available valves suitable for the present application may be used. All valves 8003 discussed herein may be changed between at least a fully closed position (no flow state) and a fully open position (flow state). Some valves 8003 may operate in a throttled (i.e., partially open) position, if desired. Note that not every valve 8003 is numbered in fig. 34 and 35 for simplicity and to minimize drawing clutter of the illustrated valves.

The coarse filter unit 8020 may be of self-cleaning design. Referring to fig. 42, oversized particles (e.g., agricultural solids or debris) that are too large to be entrained or suspended in the slurry mixture from the mixing device 8010 by the openings in the filter screen 8021 flow in a linear path across the concave upper surface of the screen 8021 toward the waste outlet 8024. Smaller solids or particles in the slurry that can pass through the screen are pushed down through the screen from the upper chamber 8028a of the filter unit 8020 into the lower chamber 8028b in a direction transverse to the slurry flow path in the upper chamber between the slurry inlet 8022 and the waste outlet 8024. It is noted that the term "laterally" or "transverse" herein does not necessarily mean perpendicular to a reference line or path, but may also include an angular orientation relative to the reference line or path. The filtered slurry (filtrate) continues to flow to the slurry recirculation flow loop 8002. This self-cleaning arrangement advantageously reduces clogging of the filter screen 8021, allowing the filter unit to continue to operate without having to frequently stop the unit to backflush/clean the screen.

The coarse filter unit 8020 may also include a bubbler system for actively filtering the slurry and for periodic backwashing to remove deposited debris on the upper surface of the filter screen 8021 that is screened from the slurry passing through the screen. The bubbler system includes a pressurized air inlet port 8025 ("bubbler") and a pressurized water inlet port 8026. In one embodiment, a push-to-connect tube of the threaded coupling may be used to attach the pressurized water tube 8026b to the water inlet port 8026, which may be threaded. A similar arrangement may be used to connect an air tube to the air inlet 8025. However, other types of fittings may be used.

The air inlet port 8025 and the water inlet port 8026 are both located on the filter unit 8020 body to introduce pressurized air and clean water into a lower cavity 8028b of the filter unit 8020 below the convex lower face of the filter screen 8021, as best shown in fig. 42. The bubbler system combines the air and water in the lower chamber 8028b to produce a pressurized flow of aerated water for normal operation of the filter unit and cleaning of the screen. In some embodiments, the lower cavity may be first filled with water before introducing pressurized air to initiate bubbler action. During normal slurry filtration operations or backwash screen cleaning cycles, the pressurized aerated water flow in the lower chamber 8028b flows upward through the filter screen to actively dislodge debris that is washed away to waste. During normal filtration operation, the aerated water stream continues to flow to prevent the formation of accumulations or deposits on the screen face that may clog the openings. Advantageously, the pressurized "foaming" action imparts a greater force to agitate and dislodge the larger chips or solid particles entrained in the slurry than water alone. In the case of soil slurries, these slurries may contain debris in the form of heavier pebbles or stones (or other foreign metallic or non-metallic objects) that are not easily removed and that may otherwise often clog the screen. The aerated water stream flushes the debris through the waste outlet 8024 to the waste. The bubbler system also advantageously minimizes the amount of water used to periodically clean the coarse filter unit 8020 when the filter unit 8020 is not in operation or between uses.

During regular screen cleaning operations for maintenance, the filtrate outlet 8023 is closed by closing its associated valve 8003. The slurry inlet 8022 may be fluidly isolated by closing the upstream valve 8003 between the mixing device 8010 and the filter unit 8020. Alternatively, it is noted that valve 8003 may remain open while the upstream mixing chamber is cleaned with clean water and then the water is flushed through the filter to waste. The filter is therefore typically not isolated from the mixing during the cleaning process. The waste outlet 8025 is opened via opening its associated valve 8003. This fluidly isolates the filter unit 8021 from the mixing apparatus 8010 and the slurry recirculation flow loop 8002. Once the filter backwash/cleaning operation is terminated, the waste outlet 8025 is closed and sealed by closing its associated valve 8003 and conversely the valves associated with the slurry inlet and outlet are re-opened to resume normal operation.

Because the coarse filter unit 8020 is a self-cleaning design and the aforementioned bubbler system operates during a normal slurry filtration process, a very small amount of unfiltered slurry may be wasted to keep the filter screen relatively free of debris and clogging. In order to minimize the amount of slurry loss, various measures are taken in the design of the filter unit. First, the slurry inlet 8022 and slurry outlet 8023 and waste outlet 8024 are oriented relative to each other to minimize wasted slurry during the filtration process. In one non-limiting embodiment, the centerlines 8022L, 8023L of the unfiltered slurry inlet 8022 and the filtrate outlet 8023, respectively, may be oriented parallel to one another. This introduces slurry in a similar orientation and extracts the slurry from the filter unit 8020 (best shown in fig. 42) to take advantage of the fact that unfiltered slurry will tend to flow most easily in the same direction as it was introduced into the filter unit. However, the centerline of the waste outlet 8024L is oriented transverse to the centerlines of the slurry inlet and slurry outlet. This results in less slurry following the waste path than the path through the filter screen 8021 due to the dynamics of the slurry entering the filter unit 8020. The filter screen 8021 is also oriented transverse to a centerline 8022L of the slurry inlet 8022 such that the incoming slurry stream is directed toward an upper face of the screen 8021. This will tend to drive the slurry down through the screen rather than angled or laterally sideways toward the waste outlet. Finally, the lower chamber 8028B of the filter unit 8020 is sized larger than the upper chamber 8028a of the filter unit to provide less flow resistance. The narrower upper chamber creates a greater resistance such that the slurry flow has a tendency to flow downwardly through the filter screen 8021.

Notably, if the expected amount of debris in the unfiltered agricultural slurry to be treated is small, the coarse filter unit 8020 can be operated in a conventional manner (rather than in a self-cleaning mode) by closing the waste outlet valve 8003 of the filter unit as desired.

A general method or treatment for filtering a slurry generally includes: providing a filter unit comprising a filter screen, an upper cavity formed above the filter screen, and a lower cavity formed below the filter screen; injecting pressurized air and water into the lower chamber to produce a aerated water stream; flowing a aerated water stream through a filter screen into an upper chamber; introducing unfiltered slurry into an upper chamber of the filter unit; and passing the unfiltered slurry through the filter screen in a direction countercurrent to the aerated water flow to produce a filtrate. Thus, when the waste outlet valve 8003 is open, the filter unit operates in a self-cleaning mode to expel a portion of the slurry with entrained oversized particles sliding along the upper surface of the filter screen 8021 through the waste outlet 8024 of the filter unit 8020 while simultaneously passing the remaining portion of unfiltered slurry downwardly through the filter screen in a direction counter-current to the aerated water flow to produce filtrate. The upper surface of the filter screen is curved in an arc from side to side and concave to form a trough that facilitates the collection of oversized particles along the screen toward the waste outlet 8024. The aerated water flow passing through the filter screen 8021 from below the screen and into the upper chamber of the filter unit 8020 agitates the particles and drives them out of the upper surface of the screen so that they are swept away from the screen so as not to interfere with the slurry filtration performance. In some embodiments, water may be first injected into the lower chamber 8028b, and then air pressure is applied to the lower chamber to create a flow of aerated water.

Closed slurry recirculation loop-density measurement

The components forming part of the closed slurry recirculation flow loop 8002 used in conjunction with measuring slurry density to determine the actual water/solids (agricultural) mass ratio for comparison with the target water/solids mass ratio required for flowable slurry that can be effectively subjected to further sample processing and chemical analysis in the analysis subsystem 3003 and its flow network will now be described. As previously described herein, subsystem 3003 ultimately measures an analyte (e.g., chemical/elemental composition) in the agricultural slurry to chemically characterize the sample. In one non-limiting example, the agricultural material to be analyzed for an analyte (e.g., a soil nutrient level such as nitrogen, phosphorus, potassium, etc.) may be soil, and the ratio is a water/soil (water to soil) ratio.

The closed slurry recirculation flow loop 8002 of the present invention shown in fig. 34 to 35 represents a modification of the recirculation flow loop 7059 shown in fig. 4. In the flow circuit 8002 of the present invention, similar components are reordered in the slurry flow path, and additional components are added as described below to optimize the accuracy of the slurry density measurement to achieve the target water/solids ratio. The flow circuit 8002 is configured and operable to promote a steady flow rate while maintaining the slurry in a well-mixed, uniform state, which advantageously improves the accuracy of agricultural slurry density measurements. This information is ultimately used to add dilution water to the flow loop 8002 in order to achieve a target agricultural water/solids mass ratio.

In one embodiment, the slurry recirculation flow circuit 8002 generally includes an agitation device 8030 operably fluidly coupled and in communication, a slurry recirculation pump 7080 fluidly driving recirculation flow through the closed recirculation flow circuit, an accumulator 8050, an agricultural solids measurement device 8060, a density measurement device 8070, and a fine filter unit 8080. The circulation or flow path of the slurry in the flow loop is indicated by the slurry flow arrows in fig. 34-35.

Stirring device

The stirring device 8030 is a fluid gate for introducing the coarsely filtered slurry (filtrate) from the mixing device 8010 into the slurry recirculation flow loop 8002 via a filter unit 8020. Filtrate flows from the filter unit to the agitation device 8030 via motive force provided by a pressurized air line 8006 that is fluidly coupled to an air source 8005 (if used) upstream of the filter unit, as previously described herein. In other embodiments, the filtrate may flow to or be pumped to the stirring device by gravity alone without the assistance of air pressure.

Fig. 51 to 63 show various views of the stirring device 8030 in isolation and in more detail. In one embodiment, the stirring device 8030 may be a mixer-type apparatus, although it is specifically configured to agitate the slurry less severely, as larger bulk agricultural solids do not need to be broken down into finer particles to initially produce the slurry. Instead, the stirring device is configured and operable to more gently stir and maintain a homogeneous mixture of water and agricultural solids (e.g., soil) for density measurement in the closed slurry recirculation flow loop 8002 shown in fig. 34-35 and described elsewhere herein.

The stirring device 8030 generally includes: a sealable and vertically elongated hollow body formed by a housing 8094, the hollow body defining a stir chamber 8031 for holding a volume of filtered slurry (filtrate); and a rotatable vane mechanism 8035. The blade mechanism 8035 is configured and operable to agitate the agricultural slurry to an extent sufficient to maintain the agricultural solids or particles suspended in the aqueous carrier liquid (diluent) of the slurry, but without excessively agitating the slurry to entrain air, which can adversely affect the slurry density measurement. The chamber 8031 forms an integral fluid portion of the slurry recirculation flow loop 8002 and slurry flow path. In one embodiment, the stirring device and chamber operate at atmospheric pressure, although the recirculation flow into the chamber is pressurized by the AODD slurry pump 7080.

The stirring device housing 8094 includes a top 8100, a bottom 8101, a right side 8103, a left side 8104, a front 8105, and a rear 8106. In one embodiment, the housing 8094 includes a plurality of components or segments, which may include a removable top cover 8090, a top section 8091, a middle section 8092, and a bottom section 8093. The segments 8091-8093 may be removably or permanently coupled together, or a combination thereof. In one embodiment, at least the bottom section 8093 is detachably coupled to the intermediate section 8092 via a threaded fastener 8095. The top cover 8090 can similarly be detachably coupled to the top section 8091 of the housing 8094 by threaded fasteners 8095. Note that only one or a few fasteners may be shown in the drawings for simplicity, recognizing that other similar holes in the stirring device housing receive similar fasteners.

The fluid connection of the stirring device 8030 in fluid communication with the stirring chamber 8031 includes a slurry inlet 8032 that receives slurry from the mixing device 8010, a slurry recirculation inlet 8033a, a slurry recirculation outlet 8033b, an overflow port 8096, and a waste outlet port 8049 to allow flushing of the stirring chamber with water and cleaning between slurry runs. The overflow port 8096 discharges excess slurry added to the chamber 8031 from the upstream mixing device 8010. The overflow port is configured for coupling to a hose/pipe at atmospheric pressure. This in turn places the stir chamber 8031 of the stirring device 8030 at atmospheric pressure during operation.

In one embodiment, the slurry inlet formed through the top section 8091 of the housing 8094 may be angled obliquely to the vertical centerline 8040 of the stirring device 8030 to deliver slurry inwardly into the stirring chamber 8031 at a similar angle. Each of these fluid connections may have an associated openable/closable valve 8003, as shown in fig. 34 (except for overflows in one embodiment), for stopping or allowing flow through or from these connections.

The vane mechanism 8035 generally includes a vane assembly 8034 and a drive unit, such as an electric drive motor 8038 coupled to an impeller or drive shaft 8036 of the vane assembly. The vane assembly 8034 also includes one or more sets of impellers or vanes 8037 mounted to the drive shaft 8036, which are capable of rotating at one or more constant predetermined speeds or variable speeds by operation of the motor 8038. Any suitable commercially available fixed or variable speed electric motor may be used in the present application.

The volumetric capacity of the stir chamber 8031 can be at least as large as that used to hold the entire contents of the agricultural slurry prepared in the mixing chamber 8013, which is transferred to the stir chamber 8031 for density measurement and water/solid mass ratio adjustment, as further described herein, as compared to the more vigorously agitated mixing device 8010. In one embodiment, the volume capacity of the stir chamber 8031 may be greater than the volume capacity of the mixing chamber 8013 of the mixing device 8010 (e.g., about 20% or more) to ensure that all of the slurry is contained.

The blade mechanism 8014 of the mixing device 8010 is intended to transfer more energy (i.e., energy input) to the slurry than the stirring device 8030 and to provide more positive agitation of the slurry in order to break down the agricultural solids in the water carrier to form an initial relatively uniform slurry mixture. From a design point of view, this can be achieved in a number of ways. In some embodiments, for example, the blade mechanism 8014 of the mixing device 8010 may be operated at a higher rotational speed (rpm-rpm) than the blade mechanism 8035 of the stirring device 8030 to more aggressively blend the bulk agricultural material and water together to create a slurry mixture. This is not necessary for a stirring device whose purpose is to simply agitate the prepared slurry, just enough to prevent precipitation of agricultural sample solids or particles from solution (i.e., to keep the slurry in a uniform state for slurry density measurement). Without the stirring device, the slurry mixture is prone to solid separation, which adversely affects the accuracy of the slurry density obtained. In one representative but non-limiting example, the mixing device blade mechanism 8014 can have a rotational speed of about 15,000 rpm, which is associated with a plurality of sets of more positively spaced blade sets 8016 on the impeller/drive shaft 8017 as shown, which are configured for greater agitation of agricultural material and water mixtures. In contrast, as one non-limiting example, the stirring device blade mechanism 8035 may have a single set of blades 8037 on the blade assembly drive shaft 8036 and a slower rotational speed on the order of about 1,000 rpm. Thus, in some embodiments, the mixing device blade mechanism 8014 may have a rotational speed of at least 10 times that of the stirring device 8030. Many other speeds may be suitably used depending on the nature of the agricultural material from which the sample is formed.

In other embodiments, to achieve more aggressive mixing in the mixing device 8010, the length of the blades 8016 may be different such that the mixing device blades have a greater length than the stirring device 8030, thereby producing a higher tip speed even at the same or slower rotational speeds as the blades in the stirring device. As described above, the stirring device blade mechanism 8035 may have fewer blades 8037 and/or less aggressive blade configurations than the blades 8016 of the mixing device 8010 to more gently agitate the slurry. Whether based on the rotational speed of the blade assembly, the number and/or length of the blades, their configuration, or tip speed, the slurry is more actively mixed in the mixing device 8010 to break down the solids in the initial slurry being prepared at a greater energy or power than the energy or power input to the slurry in the stirring device 8030. Thus, in all preferred mixing scenarios, the power consumption of the drive motor 8016 of the mixing device 8010 is greater than the power consumption of the drive motor 8038 of the stirring device 8030.

The shape or configuration of the mixing chamber 8013 and the stirring chamber 8031 may also be different in view of the different functions of the mixing device 8010 and the stirring device 8030. Referring to fig. 61, in some embodiments, the mixing chamber 8031 may have an hourglass or peanut shape or "figure eight (8)" configuration with a constricted middle waist region as further described herein, designed to accommodate two separately rotating drive shafts 8036 that may be provided for improved slurry agitation. In some embodiments, the dual drive shafts 8036 may also be counter-rotated relative to each other to further enhance the slurry agitation. These features help agitate the slurry while reducing swirl (air "tornado" along the shaft) because it is undesirable to introduce air into the slurry recirculation flow loop 8002, as it adversely affects slurry density measurement accuracy. In addition, slurry circulating in the slurry recirculation flow loop 8002 may be tangentially reintroduced or returned to the stir chamber 8031 via a recirculation inlet 8033a to further reduce air entrainment, as described below.

Additional aspects and details of the stirring device 8030 and the foregoing features will now be described. With continued reference generally to fig. 51-63, the stirring device 8030 can include a vertically elongated body defining a vertical centerline 8040 that passes through a geometric center of the stirring device. The body also defines a vertically elongated stir chamber 8031 in which a pair of blade assemblies 8034 are positioned. The stir chamber 8031 may be non-circular and oblong in shape with a lateral width from side to side that is greater than the front to back depth (best seen in fig. 61). The vane assembly shafts 8036 may be oriented parallel to one another as shown.

The stir chamber 8031 can be divided laterally/horizontally into a first section 8031a and a second section 8031b, which are separated by a narrow throat region 8041 defined by a pair of opposing and inwardly projecting baffle projections 8042 on opposite sides of a centerline 8040 (see, e.g., fig. 61). For most of the height of the stir chamber 8031, the baffle projections may be convex and extend horizontally and vertically inward in an arc (see, e.g., fig. 59). One vane assembly 8034 is shown in the center of each section 8031a, 8031b of the chamber between the sides of the stirring device. The function of the barrier projections 8041 is to enhance the stirring action of the slurry so that the slurry cannot travel around the outside or peripheral portion of the chamber 8031 only along the inner side wall 8043 of the stirring device body so as to avoid mixing. The baffle projections 8042 push the slurry inwardly toward the vertical centerline 8040 in the throat region 8041 and mix, which helps to maintain a uniform slurry mixture of agricultural solids and water. In one embodiment, the slurry inlet 8032 formed through the top section 8091 of the housing 8094 can be angled obliquely to the vertical centerline 8040 of the stirring device 8030 to introduce slurry inwardly into the stirring chamber 8031 at a similar angle in the throat region 8041 at the top end of the baffle projection 8042 (see, e.g., fig. 59). The inner bottom wall 8097 within the mixing chamber 8031 of the mixing device 8030 can be sloped downwardly and inwardly from each side of the mixing device toward a centrally located waste outlet 8049 in the bottom wall of the mixing chamber 8031 to effectively flush sediment from the chamber during periodic cleaning with flushing water between different runs of slurry preparation.

The stirring device 8030 further includes a drive mechanism for operating the blade assembly 8034. In one embodiment, the drive mechanism includes a gear box 8044 that houses a cooperating gear mechanism or gear train 8045 that includes a plurality of intermeshing gears. The shaft of the motor 8038 includes a drive gear 8038a, and each blade assembly includes a driven gear 8036a that is operatively coupled to and rotated by the motor drive gear via an intermediate gear 8046 (see, e.g., fig. 60). The gearbox 8044 may be located at the top of the stirring device near the motor 8038. In one embodiment, the gearbox 8044 may be formed from a top cover 8090 (see, e.g., fig. 58-59). A gear train 8045 is operably coupled to the motor 8038 and each vane assembly shaft 8036. The motor 8038 operates to actuate a gear train 8045, which in turn rotates the vane assembly 8034. In some embodiments previously described herein, the blade assemblies may be rotated in opposite/counter-rotational directions to each other to enhance mixing of the agricultural slurry (see, e.g., the rotational arrows of fig. 61). The gear train 8025 is configured to produce this type of counter-rotating motion of a pair of vane assemblies. The idler gear 8046 may be configured and arranged to produce counter-rotational movement of the blade assembly 8034 (see, e.g., fig. 60). In other embodiments, the blade assemblies may rotate in the same rotational direction. Notably, other gearing arrangements are possible. In addition, other methods of rotating the vane assembly instead of a gear drive arrangement may be used, such as belt drives or pneumatic air drives via air vanes coupled to a main drive shaft which in turn drives a gear train.

In operation, filtered slurry flows from coarse filter unit 8020 into stir chamber 8031 via inlet 8032. The blade assembly 8034 rotates via the aforementioned gear mechanism to agitate the slurry and prevent solids from settling out of the suspension. If slurry recirculation flow loop 8002 is initially empty, slurry may at least partially fill the loop depending on the flow loop tube diameter. Thus, in some cases, the slurry may not completely fill the loop until the slurry recirculation pump 7080 is activated, such that the pump is activated when the slurry is initially introduced into the flow loop via the agitation device 8030. In either case, the slurry recirculation pump 7080 will begin circulating slurry through the loop (see, e.g., fig. 34-35). The slurry is pumped directly into the recirculation inlet 8033a of the stirring device 8030 where it is stirred to maintain a uniform consistency. The slurry then exits the stirring device via recirculation outlet 8033b and returns to flow loop 8002 to continue to circulate through the loop and other devices as shown under the motive force of pump 7080. Any excess slurry in the flow circuit is discharged through overflow port 8096.

Notably, the recycled slurry from the slurry recycle flow loop 8002 flows tangentially into one of the two circular sections of the stir chamber 8031 (e.g., such as section 8031 b) and into the stir chamber 8031 (via the slurry recycle inlet 8033 a) (see, e.g., fig. 59 and 61). In a preferred but non-limiting embodiment, slurry is reintroduced tangentially along one of the sidewalls 8043 of section 8031b of the stir chamber to reduce air entrainment in the slurry that adversely affects slurry density measurements as previously described herein. Slurry may be extracted from the chamber 8031 within a narrow throat region 8041 between each chamber section 8031a, 8031b, where the slurry will tend to be thoroughly blended and agitated in a uniform state.

In some embodiments, the operation of the blade assembly 8034 with respect to the degree of agitation applied to the slurry in the agitation device 8030 may be controlled and automatically adjusted by the system controller 2820 based on the slurry level (and accompanying volume) in the agitation chamber 8031. When the slurry level is low, it is desirable to rotate the blade assembly at a slower speed (rpm) to reduce agitation, thereby minimizing air entrainment in the slurry that adversely affects the slurry density measurement. When the slurry level is high, the blade assembly may accelerate to ensure that the slurry mixture remains uniform and the solids remain suspended.

To implement the above described operational scheme, a level sensor 8039 may be provided that is configured and operable to measure in real time the level of slurry in the chamber 8031 of the stirring device 8030. Any suitable commercially available sensor may be used, such as, for example, but not limited to, an ultrasonic level sensor. The level sensor and motor 8039 can be operatively and communicatively linked to the system controller 2820 to control the slurry agitation speed. The motor may be a variable speed motor whose speed is adjusted by the controller 2820 based on the detected slurry level to achieve a desired degree of agitation of the slurry by decreasing or increasing the rotational speed of the blade assembly 8034. The motor 8038 may thus include a speed control circuit responsive to a control signal from the controller 2820 to adjust the speed of the motor based on the slurry level.

The method or process for controlling the blade assembly 8034 of the agitation apparatus 8030 can be summarized as the controller 2820: detecting a liquid level of the slurry in the agitation chamber 8031 via a liquid level sensor 8039; increasing or decreasing the speed of a motor 8038 operatively coupled to a pair of blade assemblies 8034 based on the detected fluid level; and rotating the blade assembly at a rate or speed corresponding to the speed of the motor. When the controller 2820 detects a first level of slurry in the chamber 8031, the controller rotates the blade assembly at a first speed. When the controller 2820 detects a second level of slurry, the controller rotates the blade assembly at a second speed different from the first speed. When the first level of slurry is lower than the second level of slurry, the controller rotates the blade assembly at a slower speed than the second level of slurry and vice versa. Other variations of variable blade speed operation are possible. In some embodiments, the blade assembly may rotate at a constant speed, regardless of the slurry level in the stir chamber 8031, which may depend on the type of agricultural slurry that has been prepared and the tendency of the accompanying solids to fall out of suspension or other factors.

Accumulator device

Figures 44 to 50 show the accumulator 8050 in isolation and in more detail. The accumulator functions to dampen pressure spikes or pulsations in the slurry circulating through the slurry recirculation flow circuit 8002. In one embodiment, the accumulator 8050 may be a straight-through design in which flow enters, travels through, and exits the accumulator in a linear or straight flow path along a single axis. The accumulator 8050 has a longitudinally elongated and split body generally comprising a first half section 8051a and a second half section 8051b that are removably coupled together, for example, via threaded fasteners. Other removable coupling methods may be used. When coupled together, the half sections 8051a, 8051b define a longitudinally elongated internal cavity 8053.

The longitudinally elongated elastomeric elastically deformable membrane 8054 extends at least the entire length and width of the cavity 8053, and is preferably slightly larger in width and length than the cavity. The diaphragm 8054 may be flat and oblong in shape (best shown in fig. 46-47) to conform to the horizontally elongated configuration of the accumulator chamber 8053. The peripheral edge of the diaphragm 8054 can be clamped and captured between the first half section 8051a and the second half section 8051b of the body, which holds the diaphragm in place. This divides the chamber 8053 into an upper gas subchamber 8053a and a lower slurry subchamber 8053b that is fluidly isolated from the gas subchamber. Each of the upper and lower subcavities may have a dome-shaped concave shape in transverse cross-section (best seen in fig. 50). When the diaphragm reaches full displacement (fully conforming to the cavity wall), it does not place undue stress on the diaphragm by conforming it to any narrow angled corners that might tear the diaphragm from fatigue failure over multiple operating cycles. The subchamber 8053a is fluidly coupled to a pressurized gas port 8057 for establishing a pre-charge pressure for the accumulator via connection to a pressurized inert gas source. The gas-pre-filled upper subchamber 8053a may be filled with a pressurized inert gas, such as air or nitrogen, to pre-charge the accumulator 8050 with a volume of gas to compensate for pressure fluctuations in the slurry flowing through the slurry recirculation flow loop 8002. Such pressure fluctuations (increases/decreases) may be due to starting/stopping the slurry recirculation pump 7080, resulting in flow and pressure fluctuations, or other factors associated with the slurry treatment system. Some pump designs can produce pressure pulses that can be of significant amplitude, which can create various problems, including adversely affecting slurry density measurements.

The slurry subchamber 8053b receives the slurry and defines a major portion of a linear/straight slurry flow passage extending through the accumulator from one end to the other. The lowermost bottom portion of the subchamber 8053b may include an integrally formed longitudinally extending slot 8053c having an arcuately curved bottom surface in transverse cross section. The slot 8053c can have a semicircular transverse cross-sectional shape as best seen in fig. 50 that is different from the transverse cross-sectional shape of the lower subchamber 8053 b. The grooves 8053c advantageously prevent the diaphragm from sealing the outlet during periods of extreme displacement due to slurry pressure fluctuations by providing a flow path that is difficult for the diaphragm to completely block, and also help to keep any sediment from moving rapidly through the accumulator in a linear direction to prevent the accumulator from settling and clogging.

The slurry subchamber 8053b is fluidly coupled to a slurry inlet 8055 at one end of the second half section 8051b and a slurry outlet 8056 that may be formed at an opposite end in the lower slurry subchamber 8053 b. The inlet 8055 is coaxially aligned with the outlet 8056, defining a longitudinal flow axis Lf extending along the length of the accumulator body therebetween. Most accumulators have a single combined inlet and outlet that cannot be effectively cleaned if used in slurry applications because agricultural solids fall out of suspension from the slurry to produce sediment deposits.

To this end, it is advantageous to use a straight-through accumulator according to the present disclosure with a specifically configured linear flow path for processing slurry with entrained solids having a cross-sectional area ratio measured directly adjacent to and below (i.e., wet side of) the flexible displaceable diaphragm 8054 of the accumulator 8050 that can allow for an efficient continuous scrubbing and cleaning of the accumulator discharge sediment by the slurry (fluid) flow between sample preparation/processing runs. In one embodiment, for example, but not limited to, the flow path cross-sectional area A1 of the lower subchamber 8053b, defined transverse to the flow axis Lf, preferably does not exceed 20 times, and more preferably does not exceed 30 times, the transverse minimum cross-sectional area A2 of the inlet or outlet of the accumulator in a preferred embodiment. The slurry inlet 8055 and the slurry outlet 8056 may have different or the same cross-sectional area A2. In the non-limiting illustrated embodiment, the cross-sectional areas of the slurry inlet and the slurry outlet are the same.

In summary, the cross-sectional area A1 of the inlet and/or outlet is preferably smaller than the total cross-sectional area A1 of the subchamber 8053b of the accumulator below the elastically deformable diaphragm 8054, as measured when the diaphragm is at rest (i.e., not deformed via a sudden increase or decrease in pressure in the fluid system). Advantageously, the sizing and overall ratio of the cross-sectional areas of the subchambers 8053b and the inlet 8055 and/or outlet 8056 helps prevent solids from falling out of the slurry and clogging the accumulator between slurry treatment runs.

In view of the fact that the cross-sectional area A1 of the lower subchamber is substantially greater than the cross-sectional area A2 (e.g., at least 20 times) of the slurry inlet 8055 and slurry outlet 8056 as described above, to ensure that solids or sediment does not fall out of suspension and accumulate inside the lower subchamber 8053b of the accumulator between slurry treatment runs, the slurry inlet and slurry outlet (and concomitantly the longitudinal flow axis Lf defined therebetween) are preferably positioned offset from and below the horizontally extending geometric longitudinal chamber centerline C1 of the lower subchamber 8053 b. The center line C1 extends through the geometric center of the lower subchamber 8053b and is vertically midway between the lowest point of the lower subchamber 8053b at the bottom of the semicircular slot 8053C and the diaphragm 8054, as shown in fig. 48. Preferably, the slurry inlet 8055 and slurry outlet 8056 are positioned at the very bottom of the subchamber 8053b, as best shown in fig. 48 and 50. In one embodiment, the subchamber 8053b includes a pair of opposing sloped and arcuately curved concave side walls 8053d that help funnel heavy sediment/solids entrained in the slurry flowing through the accumulator downward to the bottom of the subchamber where the flow has a maximum velocity along the longitudinal flow axis Lf between the slurry inlet 8055 and the slurry outlet 8056. This advantageously eliminates any corners or dead zones in the lower subchamber where sediment/solids may accumulate between slurry treatment runs.

In transverse cross section (relative to the longitudinal cavity axis Ca), the lower subchamber 8053b may not have a fully semi-circular configuration as best shown in fig. 50. Alternatively, the arcuately curved concave side walls 8053d may converge at a sharp apex 8053e at the bottommost portion of the subchamber 8053 b. This may be similar to the apex formed in the upper subchamber 8053a at the top. The lowermost slurry tank 8053c in the lower subchamber 8053b previously described herein intersects the apex 8053 e. The lowest point at the bottom of the semi-circular groove 8053c (in transverse cross-section as shown in fig. 50) is below the point or apex at which the curved converging lower subchamber sidewalls 8053d meet (see also fig. 46 and 48). The curved concave side wall 8053d of the lower subchamber 8053b can be considered to define a substantially V-shaped transverse cross-sectional shape that is opposite the semi-circular transverse cross-sectional shape of the slot 8053 c. The term "substantially" as used herein means that the curved sidewall 8053d is not flat and thus does not form a perfect V-shape. The upper subchamber 8053a may be configured complementarily to the lower subchamber 8053b, each sharing a substantially V-shaped transverse cross-section; one being a mirror image of the other on the opposite side of the diaphragm 8054 (see, e.g., fig. 50).

In addition to preventing the diaphragm 8054 from completely blocking the slurry inlet 8055 and the slurry outlet 8056 during maximum downward deformation of the diaphragm as previously described herein, the trough 8053c advantageously facilitates higher slurry flow rates therethrough through the accumulator 8050 to help keep heavy sediment/solids entrained in the slurry from moving through the accumulator as the slurry flows between the slurry inlet 8055 and the slurry outlet 8056. This also helps to prevent sediment/solids from accumulating or settling between slurry treatment runs.

The accumulator 8050 is an energy storage device and operates in a conventional manner. In operation, slurry flows through subchamber 8053b, while subchamber 8053a maintains a pressurized gas volume. If a pressure surge occurs in the slurry recirculation flow loop 8002, the excess pressure deforms the diaphragm 8054 (toward the gas subchamber 8053 a) to absorb the pressure pulse and maintain a relatively constant pressure in the flow loop. If the slurry pressure in the flow loop drops below the pre-charge pressure of the accumulator, the diaphragm will move toward the slurry subchamber 8053b to increase the slurry pressure in the flow loop. The relatively constant pressure maintained by the accumulator in the slurry recirculation flow loop 8002 increases the overall accuracy of the slurry density measurements made by the density measurement device in the flow loop.

Slurry main pump and recirculation pump

The main slurry pump 7081 shown in fig. 3-4 and the slurry recirculation pump 7080 shown in fig. 5-6, which circulates slurry through the closed slurry recirculation flow loop 8002, will now be further described. In one embodiment, a positive displacement pump, such as a pneumatic double diaphragm (AODD) pump, may be used for either or both of pumps 7080, 7081, with the unique pump head design including an internal fluid path modification designed to specifically handle agricultural slurries (e.g., soil sample slurries or others in which heavy solid particulate matter or sediment of the slurry is prone to break out of suspension). In contrast, this type of slurry is somewhat similar to that of water and sand. For such slurries, standard commercially available "off-the-shelf" AODD pumps tend to accumulate or deposit heavy sediment in the lower portion of the pumping chamber. These deposits limit flow and reduce pumping capacity, which adversely affects pumping performance and output. Cleaning the pump between samples also becomes very difficult because sediment is not easily entrained into the flow as it is flushed during cleaning.

The AODD pump 7080 of the present invention with innovative design measures is configured to minimize or eliminate sediment accumulation within the pumping chamber, overcoming the aforementioned drawbacks of standard AODD pumps for pumping slurries containing heavy particulates or solids (e.g., soil slurries).

For convenience reference to the slurry recirculation pump, an AODD slurry pump will be described, recognizing that the same pump description applies to the main slurry pump 7081 if the same design is used. However, it should be understood that in certain other embodiments of the slurry treatment system, different types of pumps may be used for the pump 7080 or 7081.

Fig. 64-70 illustrate aspects of an AODD slurry recirculation pump 7080 of a slurry recirculation flow circuit 8002 in accordance with the present disclosure. Fig. 64 and 65 are sequential cross-sectional views showing the pump internal structure and operation of the pump with internal slurry flow paths during a pumping stroke. In these figures, the pump is shown in its normal upright (vertical) operating position.

Referring initially generally to fig. 64-70, a slurry recirculation pump 7080 generally includes a pump body 8200 that defines a top end 8210, a bottom end 8211, opposite right and left side surfaces 8212a, 8212b, and a vertical longitudinal axis LA that passes through a geometric center of the pump body for ease of reference. The right pumping chamber 8201 and the left pumping chamber 8202 are formed on opposite sides of the longitudinal axis LA.

Inlet and outlet flow manifolds 8203, 8204 are coupled to opposite top and bottom ends 8210, 8211 of the body. Each flow manifold includes internal flow channels for receiving slurry from the slurry recirculation flow loop 8002 into the pump 7080 or discharging/returning slurry from the pump to the flow loop. The inlet flow manifold 8203 includes a single inlet 8203a and a pair of inlet branches 8203b, each fluidly connected to one of two inlet check valves 8220. The inlet flow manifold bifurcates or splits the inlet slurry flow from the recirculation flow loop 8002 and distributes to each pumping chamber 8201, 8202. The outlet flow manifold 8204 includes a single outlet 8204a and a pair of outlet branches 8204b, each fluidly connected to one of the outlet check valves 8221. Instead, the outlet flow manifold merges the slurry from each pumping chamber 8201, 8202 and returns the merged stream from the discharge of the pump to the recirculation flow loop 8002. In one embodiment, the aforementioned flow channels of the inlet and outlet flow manifolds may have a cylindrical shape with a circular transverse cross-section.

The slurry recirculation pump 7080 also includes right and left pump heads 8230a, 8230b (see, e.g., fig. 64-65) removably coupled to the pump body 8230 laterally adjacent the right and left pumping chambers 8201, 8202. In one embodiment, the configuration of the pump head may be similar and may be configured and constructed to provide a flow function and a closure function for the pumping chamber, as described below.

The flow function of each pump head 8230a, 8230b is provided by a plurality of fluidly interconnected internal flow channels including longitudinal flow holes 8231, upper exhaust holes 8232, and lower slurry discharge holes 8233 fluidly coupled to inlet and outlet flow manifolds 82303, 8234. The upper vent hole and the lower slurry exchange hole are in turn each fluidly coupled to a corresponding longitudinal flow hole and either the right pumping chamber 8201 or the second pumping chamber 8202, as shown. Notably, the longitudinal flow bore 8231 is fluidly connected to the pumping chambers 8201, 8202 only via the upper exhaust bore 8232 and the lower slurry exchange bore 8232. In one embodiment, the configuration of all of the holes may be elongated (i.e., longer than diameter) with a cylindrical shape having a circular transverse cross-section. Notably, although reference may be made to "vent" and "slurry exchange" ports, during various stages of the pump cycle (e.g., priming, pumping, flushing/cleaning, and air purging), either port will have a certain amount of slurry and air passing through it.

In one embodiment, the longitudinal flow holes 8231 of the pump heads 8230a, 8230b may be vertically oriented and parallel to the vertical longitudinal axis LA of the pump 7080. This orientation prevents the accumulation of sediment from the slurry within the pores. The upper vent hole 8232 and the lower slurry exchange hole 8233 may be oriented transverse to the longitudinal hole 8231. In one embodiment, the upper vent holes and the lower slurry exchange holes may be oriented vertically with respect to the longitudinal holes. Due to the function of these flow channels, the upper exhaust holes 8232 may have a smaller diameter than the lower slurry exchange holes 8233. An upper vent 8232 is fluidly coupled to the upper end portions of the pumping chambers 8201, 8202 to vent air trapped in the chambers into the longitudinal flow bore 8231 during a pumping stroke. The lower slurry exchange orifice 8233 is fluidly coupled to a lower end portion of the pumping chamber for flushing sediment out of the chamber back during a pumping stroke. Advantageously, this prevents heavy sediment in the slurry from accumulating in the chamber due to gravity, which maintains pumping capacity by eliminating flow restrictions caused by sediment accumulation. The diameter of the lower slurry exchange aperture 8233 may thus be greater than the diameter of the upper exhaust aperture 8232 and configured for bi-directional/bi-directional flow during the pumping stroke. Slurry is drawn into the pumping chamber in one direction via the lower slurry exchange orifice during the suction stroke of the pump, and the slurry is discharged back from the chamber in the opposite direction during the discharge or pumping stroke, leaving the pumping chamber 8201, 8202 as the slurry carries any heavy particles or sediment entrained in the slurry. The diameter of the upper vent holes 8232 may be smaller because their primary function is to vent air trapped in the chamber during the discharge stroke (although some small insignificant amount of slurry may be vented with the air). The smaller diameter upper vent ensures that during pumping, particularly during pump start-up and start-up of the pumping cycle, mainly air is ejected from the pumping chamber rather than slurry, to remove any residual air that may accumulate in the pumping chamber when not in operation. Once the air is purged from the pumping system and pumping chamber, these holes 8232, 8233 will primarily transfer (i.e., exchange) slurry between the longitudinal holes 8231 in the pump head and the pumping chambers 8201, 8202.

Notably, the presence of internal flow passages (flow holes 8231-8233) distinguishes the AODD pump 7080 of the present invention from conventional similar types of pumps that use only flat sealing caps or plates without internal flow passages to enclose the pumping chamber. In such prior designs, the diaphragm 8241 is entirely movable within the pump chamber for a reciprocating stroke. However, in the AODD pump design of the present invention, the diaphragm does not enter the longitudinal bore 8231. Both the pump chamber and the diaphragm are physically separated/isolated from the longitudinal bore created through the pump head by a dividing wall 8231a formed of an integral material of the pump heads 8230a, 8230b themselves (see, e.g., fig. 7). In other words, the partition wall is integrally formed by the body of the pump head.

In some embodiments, the inlet 8232a, 8233a of each of the upper vent hole 8232 and the lower slurry exchange hole 8233 into the first pumping chamber may include a concave depression to facilitate the outward discharge of the slurry and the sediment entrained in the slurry from the first pumping chamber (see, e.g., fig. 69-70). In particular, at least the lower slurry exchange holes may preferably comprise concave depressions, since most of the slurry entering and exiting the pumping chambers 8231, 8232 is exchanged with the longitudinal holes 8231 in the pump heads 8230a, 8230b through the holes 8233. To this end, the concave recess associated with the lower slurry exchange aperture 8233 may extend down to the very bottom of the pumping chamber (see, e.g., fig. 70) to avoid any dead zone at the bottom of the chamber where heavy sediment may accumulate during repeated slurry pumping cycles. However, in other embodiments, the aperture entrance may omit the concave recess.

The pumping chamber closing function includes a pump head 8230a, 8230b configured to completely close an inside recess 8234a of the pumping chamber 8231, 8232 defined by the pump body 8230. The pump head defines an outboard recess 8234b of the pumping chamber. Thus, each of the pump heads includes an integrally formed outboard recess that cooperates with a mating inboard recess of the pump body 8230 to form a shared continuous total volume that collectively defines each of the pumping chambers 8230a, 8230 b. The recesses 8234a, 8234b may be complementarily configured, each having an arcuate curved wall 8234c, which may be a mirror image of the opposing curved wall, as shown in fig. 7-8. In one embodiment, the upper vent 8232 and the lower slurry exchange hole 8233 penetrate the curved wall 8234c of the outside recess 8234b of the pump head (see, e.g., fig. 64, 65, 68, and 70). Wall 8234c physically separates longitudinal flow bore 8231 of the pump head from pump chambers 8201, 8202.

In one embodiment, the pump heads 8230a, 8230b may be formed from a solid unitary piece or block of metallic or non-metallic (e.g., plastic) material that defines the body of the pump head. The longitudinal flow holes 8231, upper vent holes 8232, and lower slurry exchange holes 8233 previously described herein may be formed integrally with and in the block via molding, casting, and/or machining (e.g., drilling/boring) depending in part on the type of material used and the method of manufacture (e.g., casting, forging, molding, etc.). The apertures 8231-8233 may thus be of cylindrical configuration having a corresponding circular cross-sectional shape, forming discrete flow channels separate from the pumping chambers 8201, 8202 and not part of the pumping chambers 8201, 8202. In other words, unlike existing AODD pump designs, slurry enters or exits the pumping chamber only via the holes 8231-8233 and not directly from the inlet manifold 8203 or outlet manifold 8204. The pump heads 8230a, 8230b are configured to be removably mounted to the pump body for access to the diaphragm for replacement and other pump maintenance. In one embodiment, the pump head may be coupled to the pump body 8200 via a threaded fastener 8235 (fig. 67).

The AODD slurry recirculation pump 7080 also includes an operating or pumping mechanism that includes a laterally translatable operating shaft 8240 that includes an elastically deformable diaphragm 8241 attached to each opposing end of the shaft. One of the diaphragms is disposed in each of the pumping chambers 8201, 8202. The shaft 8240 is oriented perpendicular to the vertical longitudinal axis LA of the pump and is reciprocally movable back and forth (e.g., left and right) during a pumping stroke. Any suitable elastically deformable elastomeric material may be used for the membrane 8241. The shaft 8240 is preferably made of metal.

The membrane 8241 has a generally disk-like or circular configuration. In one embodiment, a circumferentially extending peripheral edge 8232 may be captured between the pump heads 8230a, 8230b and a central portion of the pump body 8200 (best shown in fig. 64-65) to secure the diaphragm in place. The end of the operating shaft 8240 is fixedly coupled to the central portion of the diaphragm such that the shaft can push or pull the diaphragm during the opposite motion of the pumping stroke. Any suitable commercially available elastically deformable polymeric material having elastic memory may be used for the separator.

The pumping mechanism is driven by an air distribution system 8250 configured to alternately inject or draw air from the pumping chambers 8201, 8202 to translate the shaft back and forth during the reciprocating pumping stroke. Fig. 64 to 65 schematically illustrate an air distribution system. The air distribution system includes a pressurized air source 8252 fluidly coupled to each of the chambers 8201, 8202 by an air conduit 8251 for supplying air to one of the chambers during a pumping stroke while exhausting air from the other chamber simultaneously during a return stroke and vice versa (see dashed directional airflow arrows). Any suitable commercially available pneumatic (compressed air) dispensing system commonly used with AODD pumps may be used.

Two sets of check valves 8230a, 8230b are provided to alternately control the flow of slurry into or out of the longitudinal flow holes 8231 in each pump head 8230a, 8230 b. Referring to fig. 64-70, an inlet check valve 8260a is fluidly coupled between each of the longitudinal flow holes 8231 and the inlet flow manifold 8203. An outlet check valve 8260b is fluidly coupled between each of the longitudinal flow holes and the outlet flow manifold 8204. An inlet check valve is removably attached to the top end of the pump head, for example, via threaded fasteners 8267, and an outlet check valve is similarly attached to the bottom end of the pump head.

In one embodiment, the check valves 8260a, 8260b may be ball-type check valves. Each of the ball-type check valves generally includes a ball 8261, a ball cage 8263, and a valve body 8265 defining an internal fluid passageway 8262 extending completely through each end of the valve for fluid communication with the pump head longitudinal flow bore 8231 and the flow channels of the inlet and outlet manifolds 8203 and 8204 (see, e.g., fig. 64, 65, 68, and 70). A ball and a cage are disposed in the fluid passageway 8262, which may have any suitable shape. An annular valve seat 8264 is formed in each valve body within the fluid passageway 8262 for seating a ball and closing one of the fluid passageways. Valve body 8265 may have any suitable polygonal or non-polygonal configuration. Each valve body 8265 may be formed of a suitable metallic or non-metallic (e.g., plastic) material and may have a unitary structure.

In some embodiments, a pair of end plates 8266 may be provided, each including a flow aperture 8266a. The flow bore 8266a is in fluid communication with the valve body internal fluid passageway 8262 as shown. The cage 8263 may be fixedly attached to one of each pair of end plates. In one embodiment, the cage 8263 may be formed from circumferentially spaced and axially elongated finger tabs 8263 a. The finger tabs constrain and limit the movement of the ball 8261. Openings 8263b are formed between the finger tabs 8263a to allow slurry to pass through and out of the check valve. The cage is configured such that the ball engages the end portions of the finger projections, but does not fully enter therebetween, to keep the openings 8263b unobstructed for the slurry to pass therethrough. Notably, end plates including flow cages 8263 are attached to the outlet or discharge sides of the check valves 8260a, 8260b (see, e.g., fig. 64-65). Valve seat 8264 is located on the inlet side of the valve. For outlet check valve 8260b, a pair of end plates may thus be attached to the same end of the valve body and stacked on top of each other as shown.

The process or method for pumping slurry using slurry recirculation pump 7080 previously described herein will now be summarized with reference to fig. 64-65. In these figures, slurry flow arrows are shown as solid lines and air flow arrows are shown as dashed lines.

The method generally includes moving the operating shaft 8240 along with the diaphragm 8241 in a first direction (e.g., right) as shown in fig. 64. The method continues with pumping slurry from an inlet manifold 8203 (fluidly coupled to slurry recirculation flow circuit 8002 on the suction side of the pump) through an inlet check valve 8260a and then into a pumping chamber 8232 through longitudinal flow holes 8231 and lower slurry exchange holes each formed in a left pump head 8230b (see solid slurry flow arrows). By moving the vacuum created on the wet or fluid side of the left pumping chamber diaphragm to the right by the shaft 8230, slurry is drawn to the lower end of the chamber via the slurry exchange holes 8233. By applying air pressure to the dry or gas side of the membrane 8241 in the opposite right pumping chamber 8201, the shaft 8240 is translated laterally and linearly along this first direction (see dashed air arrow). Simultaneously, air is discharged from the left pump chamber 8202 via the air distribution system 8250.

Once the vacuum created in the chamber by the movement of the operating shaft 8240 and diaphragm 8241 has been drawn into the left pumping chamber 8202, the process continues by moving the operating shaft and diaphragm in a second, opposite direction (e.g., left) via the air distribution system 8250, as shown in fig. 65. The diaphragm 8241 in the left pumping chamber 8202 pressurizes the slurry and discharges it from the same lower slurry exchange orifice 8233 (opposite to the chamber filling direction) back into the longitudinal flow orifice 8231 in the left pump head 8203 b. The discharged or drained slurry reenters and then flows upward in the longitudinal flow bore 8231 through the outlet check valve 8260b and into the outlet manifold 8204 for discharge back into the slurry recirculation flow loop 8002.

At the same time as the slurry is being discharged from the left pumping chamber 8202, the diaphragm simultaneously discharges any air that may have been drawn into the chamber during the suction pumping stroke of the aforementioned slurry through the upper vent hole and into the longitudinal flow holes 8231 in the left pump head 8230 b. Any air present in the left pumping chamber 8202 will tend to rise and accumulate at the top end portion of the chamber 8202, where for this reason the exhaust port is fluidly coupled to the chamber 8202.

The pneumatically operated shaft 8240 of the pump 7080 is rapidly reciprocated side-to-side to repeat the process described above and pump/circulate slurry through the slurry recirculation flow loop 8002. During the pumping intake and discharge strokes, inlet check valve 8260a and outlet check valve 8260b alternately open and close, as shown in fig. 64-65. During the suction stroke of each pumping chamber 8201 or 8202, the inlet check valve opens to draw slurry into the chamber, while the outlet check valve simultaneously closes to prevent slurry from being drawn back into the pump from the outlet manifold 8204. Conversely, the opposite valve operation occurs during the pumping stroke.

Although in one non-limiting embodiment, the slurry recirculation pump 7080 is disclosed as a pneumatic double diaphragm (AODD) pump, an electric double diaphragm (EODD) may alternatively be used with the specifically configured pump heads disclosed herein. Electrically driven double diaphragm pumps utilize an electric motor and a gear or cam mechanism to translate an operating shaft-diaphragm assembly laterally and are well known in the art and need not be elaborated upon here.

Although in one non-limiting embodiment, the slurry recirculation pump 7080 is disclosed as a pneumatic double diaphragm (AODD) pump, in other embodiments the pump may be a pneumatic or electrically driven single diaphragm pump having a single pump head, pumping chamber, and diaphragm actuated by an operating shaft that may be moved linearly or rotatably to produce the pumping stroke action of the diaphragm. In other embodiments, more than two diaphragms may be used in the slurry recirculation pump. An Electrically Operated Double Diaphragm (EODD) may alternatively be used with the specifically configured pump heads disclosed herein. The electric drive shaft may be driven by an electric motor, which may include a gear and/or cam mechanism to actuate the diaphragm.

Fine filter unit

Returning to fig. 34-35, the fine filter unit 8080 in the slurry recirculation flow loop 8002 can be any of the fine filter units 8050 or 8060 previously described herein. The filter screens of these units are configured to filter out larger solid particles or precipitates in the slurry, the size of which is detrimental to further slurry processing and analysis in the chemical analysis subsystem 3003 and components thereof that may include various microfluidic processing disk devices having very small size flow channels or passages that are susceptible to blockage by such larger particles. In contrast, coarse filter unit 8020 has mesh sizes to prevent debris in the agricultural slurry from passing to slurry recirculation flow loop 8002 and devices therein, as previously described herein.

Slurry density measuring device

The slurry density measurement device 8070 in the slurry recirculation flow loop 8002 may be any suitable type of preferred digital densitometer operable to measure the density of the slurry in both dynamic and static flow conditions while the slurry is being circulated through the slurry recirculation flow loop 8002. In some embodiments, the device 8070 may be any of the previously disclosed embodiments of the density measurement device 7010 of a U-tube oscillator type densitometer. However, other digital densitometers may be used.

Agricultural solid particle density measuring device

The agricultural solid particle density (s.p.d.) measurement device 8060 in the slurry recirculation flow loop 8002 can be any digital device operable to measure the density of the solid or particulate components of the aqueous agricultural slurry. The density data measured by the sensor associated with the device 8060 can be used in conjunction with the total slurry density measurement from the slurry density measurement device 8070 to characterize the water to solids (water/solids) ratio of slurry circulating through the slurry recirculation flow loop 8002. This information can then be used to determine the appropriate amount of water to meter and add to the slurry via the stirring device 8030 to achieve a target water to solids ratio of the slurry for subsequent downstream processing in the chemical analysis subsystem. Any suitable commercially available products or electronic circuits and associated sensors may be used for the s.p.d. measurement device 8060, such as, but not limited to, the circuits and associated sensors used in Smart fixer of precision planting responsibility limited, trie, il, described in WO2014/153157, WO2014/186810, WO2015/171908, US20180168094, WO2019070617 and/or WO 2020161566.

The devices, apparatuses, and components described herein may be made of any suitable metallic material, non-metallic material (e.g., plastic), and combinations thereof, suitable for their applications and intended use conditions described herein.

In some embodiments, the primary slurry pump 7081 previously described herein may be configured the same as the slurry recirculation pump 7080 described above, and may also be a pneumatic double diaphragm (AODD) pump. Thus, the AODD pump designs disclosed herein may be used for either a main slurry pump or a recirculation pump.

Example

The following is a non-limiting example.

Example 1-an agricultural sample preparation system, the agricultural sample preparation system comprising: a mixing device fluidly coupled to a water source, the mixing device configured and operable to receive an agricultural sample and mix the sample with water to prepare a slurry; a stirring device fluidly coupled to the first mixing device, the stirring device configured to receive the slurry and maintain the slurry in an agitated mixing state; and a density measurement device fluidly coupled to the stirring device, the density measurement device arranged to receive the slurry and configured to measure a density of the slurry.

Example 2-the system of example 1, further comprising a closed slurry recirculation flow loop fluidly coupled to the stirring device, the stirring device comprising a stirring chamber forming an integral part of the slurry recirculation flow loop.

Example 3-the system of example 2, wherein the slurry recirculation flow loop comprises a slurry recirculation pump operable to circulate the slurry through the slurry recirculation flow loop comprising the stirring device.

Example 4-the system of example 3, wherein the slurry recirculation flow loop is fluidly isolated from the mixing device while slurry is being circulated through the slurry recirculation flow loop.

Example 5-the system of example 3 or 4, wherein the slurry recirculation flow loop includes the density measurement device.

Example 6-the system of example 5, wherein the density measurement device is a U-tube vibrating densitometer configured to measure slurry in a dynamic flow state or in a stagnant flow state through the U-tube vibrating densitometer.

Example 7-the system of any of examples 2-6, wherein the slurry recirculation flow loop is fluidly coupled to a slurry analysis subsystem configured to analyze the slurry for an analyte.

Example 8-the system of example 7, wherein the analyte has agriculturally relevant properties.

Example 9-the system of examples 7 or 8, wherein the slurry recirculation flow loop further comprises a fine filter unit fluidly coupled to the slurry analysis subsystem, the fine filter unit operable to pass slurry having a predetermined maximum particle size.

Example 10-the system of any one of examples 1-9, further comprising a coarse filter unit fluidly coupled between the mixing device and the stirring device, the coarse filter unit configured to remove oversized particles from the slurry received by the stirring device from the mixing device.

Example 11-the system of example 10, wherein the coarse filter unit includes a pressurized air inlet and a pressurized water inlet that together form a bubbler for removing oversized particles from a filter screen of the coarse filter unit.

Example 12-the system of any of examples 3-11, wherein the slurry recirculation flow loop further comprises a pass-through accumulator configured to suppress pressure spikes generated by the slurry recirculation pump in the slurry recirculation flow loop.

Example 13-the system of example 12, wherein the accumulator comprises: a body defining an elongate chamber; a slurry inlet at a first end of the chamber and a slurry outlet at a second end of the chamber, the slurry inlet and slurry outlet defining a longitudinal flow axis extending therethrough; and an elastically deformable diaphragm dividing the chamber into a pre-inflated body portion and a slurry portion that conveys slurry in a linear path from the inlet to the outlet.

Example 14-the system of example 14, wherein a cross-sectional area of the chamber measured transverse to the longitudinal flow axis is about thirty times a cross-sectional area of the slurry inlet and the slurry outlet.

Example 15-the system of example 2, wherein the mixing device includes a mixing chamber agitated by a rotatable mixing blade mechanism, and the stirring chamber of the stirring device is agitated by a rotatable stirring blade mechanism.

Example 16-the system of example 15, wherein the mixing blade mechanism is configured and operable to transfer greater energy into and more aggressively mix the slurry in the mixing device than the stirring blade mechanism in the stirring device.

Example 17-the system of example 16, further comprising a level sensor configured to measure a level of slurry in the stirring device, wherein a rotational speed of the stirring vane mechanism is controlled and adjusted based on the level of the slurry measured by the level sensor.

Example 18-the system of any of examples 2-17, wherein the stirring device includes a water inlet configured to add water to the slurry to dilute the slurry to a target water to agricultural solids ratio.

Example 19-the system of any of examples 2-18, wherein the stirring device includes a slurry inlet that receives slurry from the mixing device, a slurry recirculation inlet fluidly coupled to the slurry recirculation flow circuit, and a slurry recirculation outlet fluidly coupled to the slurry recirculation flow circuit.

Example 20-a double diaphragm pump, the double diaphragm pump comprising: a pump body defining a vertical longitudinal axis, a first pumping chamber and a second pumping chamber; an inlet flow manifold and an outlet flow manifold coupled to the pump body; a first pump head coupled to the pump body adjacent the first pumping chamber, the first pump head comprising a longitudinal flow bore separate from the first pumping chamber and fluidly coupled to the inlet and outlet flow manifolds, an upper vent, and a lower slurry exchange bore, each fluidly coupling the longitudinal flow bore to the first pumping chamber; an operating shaft coupled to an elastically deformable diaphragm disposed within the first pumping chamber; wherein the shaft is movable during a pump stroke to pump fluid from the inlet flow manifold to the outlet flow manifold through the longitudinal bore of the first pump head and the first pumping chamber; wherein the diameter of the upper vent hole is smaller than the diameter of the lower slurry exchange hole such that air is preferentially vented from the first pumping chamber instead of slurry during the pump stroke.

Example 21-the diaphragm pump of example 20, the diaphragm pump further comprising: an inlet check valve fluidly coupled to the bottom end of the longitudinal flow bore and the inlet flow manifold; an outlet check valve fluidly coupled to the top end of the longitudinal flow bore and the outlet flow manifold.

Example 22-the diaphragm pump of examples 20 or 21, wherein the diaphragm does not enter the longitudinal bore of the first pump head during the pump stroke.

Example 23-the diaphragm pump of any of examples 20-22, wherein the lower slurry exchange bore is configured and operable to exchange the fluid bi-directionally between the longitudinal bore and the first pumping chamber.

Example 24-the diaphragm pump of any of examples 20-23, wherein the upper vent hole and the lower slurry exchange hole are oriented transversely relative to the longitudinal flow hole and integrally formed in the first pump head.

Example 25-the diaphragm pump of example 24, wherein the longitudinal flow bore is vertically oriented and the upper and lower slurry exchange bores are arranged perpendicular to the longitudinal flow bore.

Example 26-the diaphragm pump of any of examples 20-25, wherein the upper vent is fluidly coupled to an upper end portion of the first pumping chamber and the lower slurry exchange orifice is fluidly coupled to a lower end portion of the first pumping chamber.

Example 27-the diaphragm pump of any of examples 20-26, wherein there are no other holes fluidly coupling the first pumping chamber to the first longitudinal hole other than the upper vent hole and the lower slurry exchange hole.

Example 28-the diaphragm pump of any of examples 20-27, further comprising an air distribution system fluidly coupled to the first pumping chamber on a dry side of the diaphragm, the air distribution system configured to alternately inject or extract air from the first pumping chamber to translate the shaft back and forth to pump the fluid.

Example 29-the diaphragm pump of any of examples 20-28, wherein the first pump head includes an integrally formed outboard recess having an arcuate curved wall that cooperates with a mating complementarily configured inboard recess having an arcuate curved wall integrally formed in the pump body to form a shared volume that together defines the first pumping chamber.

Example 30-the diaphragm pump of any of examples 20-29, wherein the upper vent hole and the lower slurry exchange hole are directly fluidly coupled to the outboard recess.

Example 31-the diaphragm pump of example 10 or 11, wherein the curved wall of the inboard recess is a mirror image of the curved wall of the outboard recess.

Example 31A-the diaphragm pump of any of examples 20-30, wherein the longitudinal flow bore, the upper vent bore, and the lower slurry exchange bore are cylindrical in configuration with a circular transverse cross-section.

Example 32-the diaphragm pump of any of examples 20-31A, wherein the longitudinal flow bore is physically separated from the first pump chamber by a dividing wall integrally formed by a body of the first pump head.

Example 33-the diaphragm pump of any of examples 20-32, wherein the diaphragm pump is a double diaphragm pump, the double diaphragm pump further comprising: a second pump head coupled to the body adjacent the second pumping chamber, the second pump head comprising a second longitudinal flow bore separate from the second pumping chamber and fluidly coupled to the inlet and outlet flow manifolds; a second upper vent and a second lower slurry exchange aperture, each fluidly coupling the second longitudinal flow aperture, and thus the second pumping chamber; wherein the operating shaft is linearly translatable and coupled to an elastically deformable second diaphragm disposed within the second pumping chamber; wherein the shaft is movable back and forth in a reciprocating pump stroke to alternately pump the fluid from the first pumping chamber and the second pumping chamber through the longitudinal bore of the first pump head and the second longitudinal bore of the second pump head.

Example 34-a method for pumping slurry, the method comprising: providing a dual diaphragm slurry pump comprising a vertical longitudinal axis and a pair of first and second pumping chambers, first and second pump heads closing the first and second pumping chambers, respectively, and a translatable operating shaft comprising an elastically deformable diaphragm coupled to each of opposite ends of the shaft, one of the diaphragms disposed in each of the first and second pumping chambers; moving the operating shaft in a first direction during the intake stroke; drawing slurry from an inlet manifold into the first pumping chamber through a longitudinal bore and a lower slurry exchange bore of the first pumping head, the longitudinal bore and the lower slurry exchange bore each formed in the first pumping head separate from the first pumping chamber; moving the operating shaft in a second direction during a pumping stroke; and discharging the slurry from the first pumping chamber back into the longitudinal bore of the first pump head through the lower slurry exchange bore during the pumping stroke while simultaneously discharging air from the first pumping chamber into the longitudinal bore of the first pump head through an upper vent bore; and simultaneously with the step of discharging the slurry, discharging air from the first pump chamber into the longitudinal flow bore of the first pump head through an upper vent hole during the pumping stroke; wherein the diameter of the upper vent hole is smaller than the diameter of the lower slurry exchange hole such that air is preferentially discharged from the first pumping chamber instead of slurry.

Example 35-the method of example 34, wherein the discharging step further comprises flowing the slurry through the longitudinal bore of the first pump head to an outlet manifold.

Example 36-the method of example 35, wherein the slurry flows through an outlet check valve to the outlet manifold.

Example 37-the method of example 35 or 36, wherein the extracting step further comprises first extracting the slurry from the suction manifold through the longitudinal flow holes before extracting the slurry to the first pumping chamber through the lower slurry exchange holes.

Example 38-the method of any of examples 35-37, further comprising, concurrently with the step of draining the slurry, the step of having a vent fluidly couple the longitudinal flow bore of the first pump head directly to an upper portion of a first pump chamber and having a lower slurry exchange bore fluidly couple the longitudinal flow bore of the first pump head directly to a lower portion.

Example 38A-the method of example 38, wherein there are no other holes fluidly coupling the first pumping chamber to the longitudinal bore of the first pump head other than the upper vent hole and the lower slurry exchange hole.

Example 39-the method of any one of examples 34-38A, wherein the slurry is extracted from the inlet manifold through an inlet check valve during the extracting step.

Example 40-the method of any of examples 34-39, wherein the step of moving the operating shaft in the first direction includes moving the diaphragm in the first pump chamber toward the first pump head, and the step of moving the operating shaft in the second direction includes moving the diaphragm in the first pump chamber away from the first pump head in an opposite direction.

Example 41-the method of any of examples 34-40, the method further comprising simultaneously with the step of discharging the slurry back to the first pumping head through the lower slurry exchange aperture, withdrawing slurry from the inlet manifold into the second pumping chamber through a longitudinal flow aperture and a lower slurry exchange aperture formed in the second pumping head.

Example 42-the method of any one of examples 34-41, wherein the shaft is moved by applying pressurized air to the diaphragm in the first pumping chamber or the second pumping chamber such that the diaphragm deforms to move the shaft.

Example 42A-the method of claim 34, wherein the longitudinal bore is vertically oriented and elongated, and the inlet manifold and the outlet manifold are both horizontally oriented and elongated.

Example 42B-the method of claim 42, wherein slurry flows upward in the longitudinal bore during the step of extracting slurry, and wherein the slurry flows downward in the longitudinal bore during the step of discharging the slurry.

Example 42C-the method of claim 34, wherein the inlet of each of the lower slurry exchange holes into the first pumping chamber comprises a concave depression to facilitate draining sediment entrained in the slurry outwardly from the first pumping chamber.

Example 43-a method for forming and treating an agricultural slurry, the method comprising: adding water and agricultural solids to a mixing chamber of a mixing device; agitating the water and agricultural solids with the mixing apparatus to form a slurry; discharging the slurry into a flow conduit; pressurizing the flow conduit to drive the slurry into a filter unit comprising a filter mesh; filtering the slurry through the filter screen to remove particles in the slurry that are greater than a predetermined particle size; and discharging the filtered slurry from the filter unit.

Example 44-the method of example 43, the method further comprising injecting pressurized air and water into the filter unit during the filtering step.

Example 45-the method of example 44, wherein the filtering step includes flowing the slurry through the filter screen in a first direction and flowing the pressurized air and water through the filter screen in a second direction opposite the slurry.

Example 46-the method of example 45, wherein the slurry enters a first cavity in the filter unit on a first side of the filter screen and the pressurized air and water are injected into a second cavity in the filter unit on a second side of the filter screen opposite the first side.

Example 47-the method of example 46, wherein the filter unit includes a slurry inlet configured to flow the slurry through the first cavity in a linear flow path, a waste outlet configured to discharge the oversized particles from the first cavity in the same linear flow path, and a slurry outlet configured to discharge the filtered slurry in a direction transverse to the linear flow path.

Example 48-the method of any one of examples 43-47, wherein the slurry enters the filter unit in a direction parallel to a direction in which the filtered slurry is discharged.

Example 49-the method of any of examples 43-48, wherein the mixing device is fluidly isolated from the flow conduit during the pressurizing step.

Example 50-an in-line accumulator for regulating pressure in a slurry flow conduit system, the in-line accumulator comprising: a body defining an elongate chamber; a slurry inlet at a first end of the chamber and a slurry outlet at a second end of the chamber, the slurry inlet and slurry outlet being coaxially aligned and defining a longitudinal flow axis extending therethrough; and an elastically deformable diaphragm dividing the chamber into a pre-inflated body portion and a slurry portion, the slurry portion conveying slurry in a linear path from the inlet to the outlet; wherein the diaphragm deforms as a result of an increase or decrease in pressure of the slurry to maintain a relatively constant pressure in the slurry flow conduit system.

Example 51-the accumulator of example 50, wherein the accumulator includes an axially elongated slot having a concave shape extending between the slurry inlet and the slurry outlet.

Example 52-a slurry filter unit, the slurry filter unit comprising: a body having an interior defining an upper cavity and a lower cavity; a filter screen disposed between the upper cavity and the lower cavity; an unfiltered slurry inlet fluidly coupled to the upper chamber; a waste outlet fluidly coupled to the upper chamber opposite the unfiltered slurry inlet, defining a slurry inlet flow path in the upper chamber; a filtered slurry outlet fluidly coupled to the lower cavity; wherein the filter unit is configured to pass slurry from the first cavity through the filter screen to the second cavity in a direction transverse to the slurry inlet flow path.

Example 53-the slurry filter unit of example 52, wherein the slurry inlet flow path is linear.

Example 54-the slurry filter unit of example 51 or 52, further comprising a pressurized air inlet for injecting air and a pressurized water inlet for injecting water, the pressurized air inlet and the pressurized water inlet together forming a bubbler for removing oversized particles from the filter screen.

Example 55-the slurry filter unit of example 54, wherein the pressurized air inlet and the pressurized water inlet are fluidly coupled to the lower cavity below the filter screen.

Example 56-the slurry filter unit of example 55, wherein the air and water flow through the filter screen in a direction from the lower cavity to the upper cavity.

Example 57-the slurry filter unit of any one of examples 51-56, wherein the filter screen is elongated and arcuately curved in configuration, thereby defining a concave side facing the upper cavity and a convex side facing the lower cavity.

Example 58-the slurry filter unit of any of examples 51-57, wherein the unfiltered slurry inlet includes an elastically deformable segmented tube coupling including a plurality of radially deformable elongated fingers, wherein longitudinal slits circumferentially separate the fingers, the tube coupling configured to insert a flow tube inside the tube coupling.

Example 59-the slurry filter unit of any one of examples 51-58, wherein the unfiltered slurry inlet and the filter slurry outlet each define respective centerlines that are parallel to one another.

Example 60-a slurry stirring device, the slurry stirring device comprising: an elongated housing defining a vertical centerline and a stir chamber; a slurry inlet configured to receive the slurry; a slurry recirculation inlet configured to be fluidly coupled to a closed slurry recirculation flow loop; and a slurry recirculation outlet configured to be fluidly coupled to the slurry recirculation flow loop; and a rotatable blade mechanism configured to maintain the slurry in an agitated mixing state in the stir chamber.

Example 61-the slurry stirring device of example 60, further comprising a motor operatively coupled to the blade mechanism and configured to rotate the blade mechanism.

Example 62-the slurry stirring device of examples 60 or 61, wherein the vane mechanism includes at least a first vane assembly including a first drive shaft operatively coupled to the motor and a first set of vanes fixedly coupled to the first drive shaft.

Example 63-the slurry stirring device of example 62, wherein the first drive shaft is vertically oriented and the first set of vanes is disposed in a bottom of the slurry chamber.

Example 64-the slurry stirring device of example 63, further comprising a second blade assembly comprising: a vertical second drive shaft operatively coupled to the motor; and a second set of vanes fixedly coupled to the second drive shaft and disposed in a bottom portion of the slurry chamber.

Example 65-the slurry stirring device of example 64, wherein the first drive shaft and the second drive shaft are operatively coupled to the motor through a gear train.

Example 66-the slurry stirring device of examples 64 or 65, wherein the first blade assembly rotates in a first rotational direction and the second blade assembly rotates in a second rotational direction.

Example 67-the slurry stirring device of example 66, wherein the slurry recirculation inlet is configured to introduce slurry from the slurry recirculation flow loop tangentially to an interior sidewall of the stirring chamber.

Example 68-the slurry stirring device of example 67, wherein the slurry recirculation inlet is further configured to introduce the slurry into the stirring chamber in a same direction as the second direction of rotation of the second blade assembly.

Example 69-the slurry stirring device of any one of examples 64 to 68, wherein a transverse cross-section of the stirring chamber is in the shape of a number eight, forming a first section and a second section separated by a narrow throat region of the stirring chamber.

Example 70-the slurry stirring device of example 69, wherein the first blade assembly is disposed in the first section of the stirring chamber and the second blade assembly is disposed in the second section of the stirring chamber.

Example 71-the slurry stirring device of examples 69 or 70, wherein the slurry recirculation outlet is disposed in the narrow throat region of the stirring chamber between the first section and the second section.

Example 72-the slurry stirring device of any one of examples 60-71, wherein the stirring device further comprises an overflow port fluidly coupled to a top end of the stirring chamber and a waste outlet port fluidly coupled to a bottom of the stirring chamber.

Example 73-the slurry stirring device of any one of examples 60 to 72, further comprising a water inlet configured to add water to the slurry to dilute the slurry.

Example 74-the slurry stirring device of any one of examples 60-73, further comprising a level sensor configured to measure a level of slurry in the stirring chamber, wherein a rotational speed of the stirring vane mechanism is controlled and adjusted based on the level of the slurry in the stirring chamber measured by the level sensor.

Example 75-the slurry stirring device of any one of examples 60 to 74, wherein the housing of the stirring device has a segmented construction comprising a removable top cover, a top section, a middle section, and a bottom section.

Other examples-methods for forming/treating agricultural slurries

A method for forming and treating an agricultural slurry, the method comprising: adding water and agricultural solids to a mixing chamber of a mixing device; agitating the water and the agricultural solids with the mixing apparatus at a first speed to form a slurry; discharging the slurry from the mixing device into a filter unit via a flow conduit fluidly coupled between the mixing device and the filter unit; coarse filtering the slurry through the filter screen of a coarse filter to remove particles in the slurry that are greater than a predetermined first maximum particle size; and receiving the filtered slurry from the filter unit in a stirring chamber of a stirring device defining a stirring chamber; and agitating the slurry in the agitation device at a second speed different from the first speed.

The method of example 1A, wherein the mixing device includes a rotatable first blade mechanism that rotates during the agitating the water and the agricultural solids step to form the slurry, and the agitating device includes a rotatable second blade mechanism that rotates during the agitating the slurry step.

The method of example 1A or 2A, wherein the first speed is faster than the second speed.

The method of any one of examples 1A-3A, wherein the stir chamber of the stirring device forms an integral part of a closed slurry recirculation flow loop fluidly coupled to the coarse filter unit.

The method of example 4A, wherein the slurry recirculation flow loop comprises a slurry recirculation pump that circulates the slurry through the slurry recirculation flow loop and the stirring device.

The method of example 5A, wherein the slurry recirculation flow loop is fluidly isolated from the mixing device while the slurry is being circulated through the slurry recirculation flow loop.

The method of example 5A or 6A, wherein the stirring device is operable to maintain the slurry in a uniformly mixed state as the slurry is circulated through the slurry recirculation flow loop.

The method of example 7A, further comprising measuring a density of the slurry in the uniformly mixed state while circulating the slurry through the slurry recirculation flow loop.

The method of example 8A, wherein the slurry recirculation flow loop comprises a density measurement device that measures the density of the slurry.

The method of example 9A, wherein the density measurement device is a U-tube vibrating densitometer configured to measure slurry in a dynamic flow state through the U-tube vibrating densitometer or in a stagnant flow state.

The method of any one of examples 1A-10A, wherein the slurry recirculation flow loop is fluidly coupled to a slurry chemical analysis subsystem configured to analyze the slurry for an analyte of agricultural relevant significance.

The method of example 11A, further comprising fine filtering the slurry by the fine filter unit fluidly disposed within the slurry recirculation flow loop prior to the step of flowing the filtered slurry from the fine filter unit to the slurry chemical analysis subsystem.

The method of example 12A, wherein the fine filter unit is configured to remove solid particles from the slurry, the solid particles having a predetermined second maximum particle size that is smaller than the predetermined first maximum particle size of the coarse filter unit.

The method of any one of examples 1A-13A, further comprising pressurizing the flow conduit with air between the mixing device and the stirring device to drive the slurry through the coarse filter unit and into the stirring device.

The method of example 14A, wherein the mixing device is fluidly isolated from the flow conduit during the pressurizing step.

The method of example 1A, further comprising injecting pressurized air and water through the coarse filter unit during the coarse filtration step to form an aerated flow to prevent solid particles greater than the predetermined first maximum particle size from clogging the filter screen.

The method of example 16A, wherein the coarse filtering step comprises flowing the slurry through the filter screen in a first direction and flowing the aeration flow through the filter screen in a second direction opposite the first direction.

The method of example 17A, wherein the slurry enters a first cavity in the coarse filter unit on a first side of the filter screen and the pressurized air and water are injected into a second cavity in the filter unit on a second side of the filter screen opposite the first side.

The method of example 18A, wherein the coarse filter unit includes a slurry inlet configured to flow the slurry through the first cavity in a linear flow path, a waste outlet configured to discharge the oversized particles from the first cavity in the same linear flow path, and a slurry outlet configured to discharge the filtered slurry in a direction transverse to the linear flow path.

The method of any one of examples 5A-19A, wherein the slurry recirculation flow loop further comprises an accumulator positioned upstream of the slurry pump, the accumulator configured to dampen pressure spikes in the slurry recirculation flow loop.

Other examples-accumulator

An in-line accumulator for regulating pressure in a slurry flow conduit system, the in-line accumulator comprising: a body defining an elongate chamber; an elastically deformable diaphragm dividing the chamber into an upper subchamber configured to be pre-filled with an inert gas and a lower subchamber configured to deliver a slurry; the lower subchamber defines a geometric longitudinal chamber centerline; a slurry inlet formed at a first end of the lower subchamber and a slurry outlet formed at an opposite second end of the lower subchamber, the slurry inlet and slurry outlet being coaxially aligned with each other and defining a longitudinal flow axis extending therebetween; the longitudinal flow axis defined by the slurry inlet and the slurry outlet is vertically offset from the longitudinal cavity centerline of the lower subchamber; wherein the diaphragm deforms as a result of an increase or decrease in the slurry pressure to maintain a constant pressure in the slurry flow conduit system.

The accumulator of example 1B, wherein the slurry is flowable through the lower subchamber along a linear flow path from the slurry inlet to the slurry outlet.

The accumulator of example 1B or 2B, wherein the lower subchamber includes a longitudinal elongate slot formed therein at a bottom of the body, the longitudinal elongate slot configured to collect sediment entrained in the slurry and move the sediment through the lower subchamber when the slurry is flowing.

The accumulator of example 3B, wherein the slot extends entirely along a length of the body between the slurry inlet and the slurry outlet.

The accumulator of example 3B or 4B, wherein the tank is coaxially aligned with the slurry inlet and the slurry outlet.

The accumulator of any one of examples 3 to 5B, wherein the groove has a semi-circular transverse cross-sectional shape.

The accumulator of example 6B wherein the slots have a different transverse cross-sectional shape than the lower subchamber.

The accumulator of example 7B wherein the lower subchamber has a generally V-shaped transverse cross-sectional shape.

The accumulator of any one of examples 3B to 8B, wherein the lower subchamber is formed by tilting and converging arcuately curved concave side walls of the body of the accumulator intersecting the slot.

The accumulator of any one of examples 1B to 9B, wherein the slurry inlet and the slurry outlet are located at a bottom of the lower subchamber.

The accumulator of example 1B wherein the cross-sectional flow path area of the lower subchamber is no more than 30 times the cross-sectional minimum area of the slurry inlet or the slurry outlet of the accumulator.

The accumulator of example 11B, wherein the slurry inlet and the slurry outlet each have the same cross-sectional area.

The accumulator of example 1B wherein the lower subchamber has a generally V-shaped transverse cross-sectional shape.

The accumulator of example 13B, wherein the upper subchamber has a substantially V-shaped transverse cross-sectional shape that complements the transverse cross-sectional shape of the lower subchamber.

The accumulator of any one of examples 1B to 14B, wherein the diaphragm is sandwiched and captured between first and second half sections of the body that are detachably coupled together.

The accumulator of example 1B, wherein the accumulator includes a pressurized gas port arranged to pre-charge the upper subchamber with the inert gas.

The accumulator of any one of claims 1B to 16B wherein the slurry is an agricultural slurry.

The accumulator of claim 17B wherein the agricultural slurry is a soil slurry.

Notably, the unique features enumerated in the foregoing examples 1B through 18B and described in further detail herein before relate to an accumulator that is specifically configured and operable to successfully carry slurries having entrained/suspended solids and sediment, such as soil slurries, unlike those accumulator designs of the prior art that do not contain a significant amount of suspended solids alone.

Other examples-slurry filtration

A slurry filter unit, the slurry filter unit comprising: a Y-shaped body defining an upper cavity and a lower cavity therein; a filter screen disposed between the upper cavity and the lower cavity; an unfiltered slurry inlet fluidly coupled to the upper chamber; a waste outlet fluidly coupled to the upper chamber opposite the unfiltered slurry inlet, defining a slurry inlet flow path in the upper chamber; a filtered slurry outlet fluidly coupled to the lower cavity; wherein the filter unit is configured to pass slurry through the filter screen from the first cavity to the second cavity in a direction transverse to the slurry inlet flow path.

The slurry filter unit of example 1C, wherein the slurry inlet flow path is linear such that the slurry flows parallel to the length of the filter screen.

The slurry filter unit of example 1C or 2C, further comprising a pressurized air inlet configured for injecting air and a pressurized water inlet configured for injecting water, the pressurized air inlet and the pressurized water inlet together forming a bubbler for removing oversized particles from the filter screen.

4c. the slurry filter unit of example 3C, wherein the pressurized air inlet and pressurized water inlet are fluidly coupled to the lower cavity below the filter screen.

The slurry filter unit of example 4C, wherein the pressurized air inlet and pressurized water inlet are arranged to flow pressurized air and water upwardly through the filter screen in a direction from the lower cavity to the upper cavity to clean oversized particles from the filter screen.

The slurry filter unit of example 5C, wherein the filter unit is configured such that the pressurized air and water flow upwardly through the filter screen from the lower cavity to the upper cavity.

The slurry filter unit of any one of examples 1C-6C, wherein the filter screen is arcuately curved in configuration from side to side, thereby defining a concave side facing the upper cavity and a convex side facing the lower cavity.

The slurry filter unit of any one of examples 1C-7C, wherein the upper cavity is angled obliquely downward relative to a horizontal reference plane such that the slurry travels through the filter screen in the same oblique angled flow path.

The slurry filter unit of any one of examples 2C, 7C, or 8C, wherein the unfiltered slurry inlet is disposed at one end of the upper cavity and a waste outlet is disposed at an opposite end thereof.

The slurry filter unit of example 9C, wherein the upper cavity is configured such that oversized particles entrained in the slurry mixture that pass through the mesh openings in the filter screen flow in a linear path past a concave upper surface of the screen to the waste outlet.

The slurry filter unit of any one of examples 1C-10C, wherein the unfiltered slurry inlet includes an elastically deformable segmented pipe coupling including a plurality of radially deformable elongated fingers having longitudinal slots circumferentially separating the fingers, the pipe coupling configured to insert a flow pipe therein.

The slurry filter unit of any one of examples 1C to 11C, wherein the unfiltered slurry inlet and the filtered slurry outlet each define respective centerlines that are parallel to one another.

The slurry filter unit of any one of examples 1C-12C, wherein the filter unit is oriented such that the upper cavity is positioned above the lower cavity and the filter screen extends horizontally between the upper cavity and the lower cavity when the filter unit is in use.

The slurry filter unit of any one of examples 1C to 13C, wherein the slurry comprises water and agricultural sample material.

The slurry filter unit of example 14C, wherein the agricultural sample material is soil.

The slurry filter unit of any one of examples 1C-15C, wherein the lower cavity has an inclined frustoconical shape such that the lower cavity tapers downwardly in a direction from an upper portion adjacent the filter screen to the filtered slurry outlet at a bottom of the lower cavity.

The slurry filter unit of any one of examples 1C-16C, wherein the upper cavity of the body is covered by a transparent plastic cover configured to allow a user to see the filter screen.

A method for filtering a slurry, the method comprising: providing a filter unit comprising a filter screen, an upper cavity formed above the filter screen, and a lower cavity formed below the filter screen; injecting pressurized air and water into the lower chamber to produce a aerated water stream; flowing the aerated water stream through the filter screen into the upper cavity; introducing unfiltered slurry into the upper chamber of the filter unit; and passing the unfiltered slurry through the filter screen in a direction countercurrent to the aerated water flow to produce a filtrate.

The method of example 18C, wherein the filter unit has a Y-shaped body.

The method of example 18C or 19C, the method further comprising: introducing the unfiltered slurry into the upper chamber from an unfiltered slurry inlet of the filter unit in a direction parallel to a length of the filter screen and flowing along the length of the filter screen; a portion of the slurry with oversized particles entrained in the slurry is caused to flow in a linear flow path along an upper surface of the filter screen toward a waste outlet in the upper chamber directly opposite the unfiltered slurry inlet, the oversized particles being too large to pass through mesh openings in the filter screen.

The method of example 20C, wherein the upper surface of the filter screen is arcuately curved and concave shaped from side to form a trough.

The method of example 20C or 21C, wherein the flow of the oversized particle-entrained slurry through the waste outlet is controlled by an openable and closable waste valve fluidly coupled to the waste outlet.

The method of example 22C, wherein the filter unit is operated in a self-cleaning mode while the waste valve is opened to discharge the portion of slurry with entrained oversized particles, concurrent with the step of passing the unfiltered slurry through the filter screen in a direction counter-current to the aerated water flow to produce filtrate.

The method of any one of examples 18C-23C, wherein the step of injecting pressurized air and water into the lower cavity comprises first injecting pressurized water and then applying air pressure to create a aerated water stream.

The method of any one of examples 18C-24C, wherein air is injected through an air inlet port in the lower cavity that is separate from a water inlet portion in the lower cavity through which the pressurized water is injected.

While the foregoing description and drawings represent some example systems, it should be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope of the accompanying claims and their equivalents. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. Furthermore, many variations on the methods/processes described herein are possible. Those skilled in the art will further appreciate that the invention may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the invention, which are particularly adapted to specific environments and operative requirements without departing from the principles of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims and their equivalents, and not limited to the foregoing description or embodiments. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.

Claims

1. A double diaphragm pump, the double diaphragm pump comprising:

a pump body defining a vertical longitudinal axis, a first pumping chamber and a second pumping chamber;

an inlet flow manifold and an outlet flow manifold coupled to the pump body;

a first pump head coupled to the pump body adjacent the first pumping chamber, the first pump head comprising a longitudinal flow bore separate from the first pumping chamber and fluidly coupled to the inlet and outlet flow manifolds, an upper vent, and a lower slurry exchange bore, each fluidly coupling the longitudinal flow bore to the first pumping chamber;

an operating shaft coupled to an elastically deformable diaphragm disposed within the first pumping chamber;

wherein the shaft is movable during a pump stroke to pump fluid from the inlet flow manifold to the outlet flow manifold through the longitudinal bore of the first pump head and the first pumping chamber;

wherein the diameter of the upper vent hole is smaller than the diameter of the lower slurry exchange hole such that air is preferentially vented from the first pumping chamber instead of slurry during the pump stroke.

2. The diaphragm pump of claim 1, further comprising: an inlet check valve fluidly coupled to the bottom end of the longitudinal flow bore and the inlet flow manifold; an outlet check valve fluidly coupled to the top end of the longitudinal flow bore and the outlet flow manifold.

3. A diaphragm pump according to claim 1 or 2, wherein the diaphragm does not enter the longitudinal bore of the first pump head during the pump stroke.

4. A diaphragm pump according to any one of claims 1 to 3, wherein the lower slurry exchange aperture is configured and operable for bi-directional exchange of the fluid between the longitudinal aperture and the first pumping chamber.

5. The diaphragm pump of any of claims 1-4, wherein the upper vent hole and the lower slurry exchange hole are oriented transversely relative to the longitudinal flow hole and integrally formed in the first pump head.

6. The diaphragm pump of claim 5, wherein the longitudinal flow holes are oriented vertically and the upper and lower slurry exchange holes are arranged perpendicular to the longitudinal flow holes.

7. The diaphragm pump of any of claims 1-6, wherein the upper vent is fluidly coupled to an upper end portion of the first pumping chamber and the lower slurry exchange orifice is fluidly coupled to a lower end portion of the first pumping chamber.

8. The diaphragm pump of any of claims 1-7, wherein there are no other holes fluidly coupling the first pumping chamber to the first longitudinal hole other than the upper vent hole and the lower slurry exchange hole.

9. The diaphragm pump of any of claims 1-8, further comprising an air distribution system fluidly coupled to the first pumping chamber on a dry side of the diaphragm, the air distribution system configured to alternately inject or extract air from the first pumping chamber so as to translate the shaft back and forth to pump the fluid.

10. A diaphragm pump according to any one of claims 1 to 9, wherein the first pump head comprises an integrally formed outboard recess having an arcuate curved wall that cooperates with a mating complementarily configured inboard recess having an arcuate curved wall integrally formed in the pump body so as to form a shared volume that together defines the first pumping chamber.

11. The diaphragm pump of any of claims 10, wherein the upper vent hole and the lower slurry exchange hole are directly fluidly coupled to the outboard recess.

12. A diaphragm pump according to claim 10 or 11, wherein the curved wall of the inner recess is a mirror image of the curved wall of the outer recess.

13. The diaphragm pump of any of claims 1-12, wherein the longitudinal flow bore, the upper vent bore, and the lower slurry exchange bore are cylindrical in configuration with a circular transverse cross-section.

14. A diaphragm pump according to any one of claims 1 to 13, wherein the longitudinal flow bore is physically separated from the first pump chamber by a dividing wall integrally formed by the body of the first pump head.

15. The diaphragm pump of any of claims 1-14, wherein the diaphragm pump is a double diaphragm pump, the double diaphragm pump further comprising:

a second pump head coupled to the body adjacent the second pumping chamber, the second pump head comprising a second longitudinal flow bore separate from the second pumping chamber and fluidly coupled to the inlet and outlet flow manifolds, a second upper vent and a second lower slurry exchange bore, each fluidly coupling the second longitudinal flow bore to the second pumping chamber;

Wherein the operating shaft is linearly translatable and coupled to an elastically deformable second diaphragm disposed within the second pumping chamber;

wherein the shaft is movable back and forth in a reciprocating pump stroke to alternately pump the fluid from the first pumping chamber and the second pumping chamber through the longitudinal bore of the first pump head and the second longitudinal bore of the second pump head.

16. A method for pumping a slurry, the method comprising:

providing a dual diaphragm slurry pump comprising a vertical longitudinal axis and a pair of first and second pumping chambers, first and second pump heads closing the first and second pumping chambers, respectively, and a translatable operating shaft comprising an elastically deformable diaphragm coupled to each of opposite ends of the shaft, one of the diaphragms disposed in each of the first and second pumping chambers;

moving the operating shaft in a first direction during an intake stroke;

drawing slurry from an inlet manifold into the first pumping chamber through a longitudinal bore and a lower slurry exchange bore of the first pumping head, the longitudinal bore and the lower slurry exchange bore each formed in the first pumping head separate from the first pumping chamber;

Moving the operating shaft in a second direction during a pumping stroke; and

draining the slurry from the first pumping chamber through the lower slurry exchange bore back into the longitudinal bore of the first pump head during the pumping stroke while simultaneously draining air from the first pumping chamber through an upper vent bore into the longitudinal bore of the first pump head; and

simultaneously with the step of discharging the slurry, discharging air from the first pump chamber into the longitudinal flow bore of the first pump head through an upper vent hole during the pumping stroke;

wherein the diameter of the upper vent hole is smaller than the diameter of the lower slurry exchange hole such that air is preferentially discharged from the first pumping chamber instead of slurry.

17. The method of claim 16, wherein the discharging step further comprises flowing the slurry through the longitudinal bore of the first pump head to an outlet manifold.

18. The method of claim 17, wherein the slurry flows through an outlet check valve to the outlet manifold.

19. The method of claim 17 or 18, wherein the extracting step further comprises first extracting the slurry from the suction manifold through the longitudinal flow holes before extracting the slurry through the lower slurry exchange holes to the first pumping chamber.

20. The method of any one of claims 17 to 19, simultaneously with the step of discharging the slurry, having a vent fluidly coupling the longitudinal flow bore of the first pump head directly to an upper portion of a first pump chamber and having a lower slurry exchange bore fluidly coupling the longitudinal flow bore of the first pump head directly to a lower portion.

21. The method of claim 20, wherein there are no other holes fluidly coupling the first pumping chamber to the longitudinal bore of the first pump head other than the upper vent hole and the lower slurry exchange hole.

22. The method of any one of claims 16 to 21, wherein the slurry is extracted from the inlet manifold through an inlet check valve during the extracting step.

23. The method of any one of claims 16 to 22, wherein the step of moving the operating shaft in the first direction comprises moving the diaphragm in the first pump chamber towards the first pump head, and the step of moving the operating shaft in the second direction comprises moving the diaphragm in the first pump chamber away from the first pump head in an opposite direction.

24. The method of any one of claims 16 to 23, further comprising withdrawing slurry from the inlet manifold into the second pumping chamber through longitudinal flow holes and lower slurry exchange holes formed in the second pumping head simultaneously with the step of discharging the slurry back to the first pumping head through the lower slurry exchange holes.

25. The method of any one of claims 16 to 24, wherein the shaft is moved by applying pressurized air to the diaphragm in the first pumping chamber or the second pumping chamber such that the diaphragm deforms to move the shaft.

26. The method of claim 16, wherein the longitudinal bore is vertically oriented and elongated, and the inlet manifold and the outlet manifold are both horizontally oriented and elongated.

27. The method of claim 25, wherein slurry flows upwardly in the longitudinal bore during the step of extracting slurry and flows downwardly in the longitudinal bore during the step of discharging slurry.

28. The method of claim 16, wherein an inlet of each of the lower slurry exchange holes into the first pumping chamber includes a concave depression to facilitate draining sediment entrained in the slurry outwardly from the first pumping chamber.