WO2018156974A1

WO2018156974A1 - Gravimetric apparatus for transferring fluids

Info

Publication number: WO2018156974A1
Application number: PCT/US2018/019549
Authority: WO
Inventors: Christian David ZEIGLER
Original assignee: GreenStract LLC
Current assignee: GreenStract LLC
Priority date: 2017-02-24
Filing date: 2018-02-23
Publication date: 2018-08-30
Anticipated expiration: 2019-08-24
Also published as: WO2018156974A8

Abstract

Apparatuses, methods and systems for dispensing liquids and fluids at specified flow rates are disclosed. In many embodiments, a pump is not required. Some embodiments are configured to provide constant flow rates, and other embodiments are configured to provide variable flow rates. Some embodiments provide for force systems or pumps. Some of the disclosed embodiments can be configured for specified flow rates, whether variable or constant, without pumps, without human intervention during the dispensing, and without any electronic or other feedback system.

Description

GRAVIMETRIC APPARATUS FOR TRANSFERRING FLUIDS

[0001] This application may contain material that is subject to copyright, mask work, and/or other intellectual property protection. The respective owners of such intellectual property have no objection to the facsimile reproduction of the disclosure by anyone as it appears in published Patent Office file/records, but otherwise reserve all rights.

RELATED APPLICATION

[0002] This application claims the benefit of U.S. Provisional Application No. 62/463,386 filed on February 24, 2017. The entire teachings of the above application are incorporated herein by reference.

BACKGROUND

[0003] Precision fluid delivery often requires expensive pumps, regulators, feedback systems, and controllers. When fluids must be delivered in remote locations or in dangerous environments, engineering challenges are increased, as batteries are required, explosion-proof circuitry, and corrosion resistant components. For example, sewer systems are often enclosed spaces filled with noxious and flammable gases situated far from utilities and easy access, but which require treatment with chemicals to maintain operations.

SUMMARY

[0004] The disclosure and embodiments discussed herein relate to apparatuses, methods and systems for dispensing liquids and fluids at specified flow rates. Some embodiments are configured to provide a constant flow rate, and other embodiments are configured to provide variable flow rates. The disclosed embodiments can be configured for pre-set flow rates, whether variable or constant, without human intervention during the dispensing, and without any electronic or other feedback system. Rather, the mechanisms and teachings of some

embodiments described herein enable an arbitrary flow rate to be set in a flow rate vs. time function. Embodiments can be configured for extended uses, such as for several days or weeks of uninterrupted use at the known, desired flow rate or flow rates. Embodiments can also be configured for shorter and longer flow rate programs using mechanisms described in this disclosure. Traditionally, pumping is the chosen method of transferring fluids. The disclosed embodiments can be utilized without pumping. [0005] Described herein is an apparatus and method for delivering a liquid. The apparatus can include a reservoir for holding a liquid, a flexible conduit providing an outlet from the reservoir, the flexible conduit having an exit at a fixed exit point, and a means for variably adjusting height of the reservoir relative to the fixed exit point, the height of the reservoir being adjusted relative to a quantity of liquid in the reservoir such that hydrostatic pressure of the liquid in the reservoir is constant relative to the fixed exit point of the flexible conduit.

[0006] Described herein is a method for delivering a liquid. The method can include providing an apparatus for delivering the liquid, wherein the apparatus is configured as described herein, and providing liquid to apparatus, such that liquid flows from the reservoir, through the flexible conduit, and exits the flexible conduit at the fixed exit point.

[0007] The apparatus can be configured so that the liquid in the reservoir has a height that is constant relative to the fixed point. In some embodiments, the reservoir can be suspended.

[0008] In some embodiments, the means for variably adjusting the height of the reservoir is selected from the group consisting of: one or more springs; one or more elastic members; one or more elastically deformable materials; one or more rubber bands; one or more bungee cords; one or more materials that provide a predictable force as a function of displacement; and one or more materials that obey Hooke's law. In some embodiments, reservoir is suspended from one or more springs. In some embodiments, the one or more springs are suspended, directly or indirectly, from a manhole. In some embodiments, the apparatus can further include a mounting bracket configured for attachment to a manhole, whereby the apparatus is suspended indirectly from the manhole via the mounting bracket. In some embodiments, the mounting bracket includes a central frame and one or more members slidably attached to the central frame, wherein the one or more members are configured to sit on a lip of a manhole.

[0009] In some embodiments, the means for variably adjusting the height of the suspended reservoir can include a fulcrum and lever. In some embodiments, the means for variably adjusting the height of the suspended reservoir include at least two fulcrums and at least two levers. In some embodiments, one of the levers is actuated by one or more floating objects disposed in a liquid.

[0010] In some embodiments, the means for variably adjusting the height of the suspended reservoir can include a gear. In some embodiments, the apparatus can include a geared cable that interfaces with the gear. [0011] In some embodiments, the means for variably adjusting the height of the suspended reservoir can include one or more pulleys.

[0012] In some embodiments, the flexible conduit can further include a means for restricting flow of liquid through the flexible conduit. In some embodiments, the flexible conduit has a length and an inner surface cross-sectional area, and wherein a portion of the inner surface cross- sectional area of the flexible conduit decreases and restricts flow of liquid through the flexible conduit. In some embodiments, the length and inner surface cross-sectional area of the flexible conduit are configured to create a constant pressure drop of liquid through the flexible conduit. In some embodiments, the inner surface cross-sectional area of the flexible conduit is configured to permit flow of liquid at a constant rate as the volume of liquid in the reservoir changes.

[0013] In some embodiments, the means for variably adjusting the height of the reservoir exerts a force substantially equivalent in magnitude, but opposite in direction, to a gravitational force exerted by liquid in the reservoir. In some embodiments, the one or more springs have a combine spring constant such that a force exerted by the one or more springs is substantially equivalent in magnitude, but opposite in direction, to a gravitational force exerted by liquid in the reservoir.

[0014] In some embodiments, the means for variably adjusting the height of the reservoir has a constant of force per unit of displacement substantially equivalent to a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant. In some embodiments, the one or more springs have a spring constant of force per unit of displacement substantially equivalent to a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant.

[0015] In some embodiments, the means for variably adjusting the height of the reservoir has a force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir. In some embodiments, the one or more springs have a spring constant of force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir.

[0016] In some embodiments, the means for variably adjusting the height of the reservoir has a force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir decreases as liquid exits the reservoir. In some embodiments, the one or more springs have a spring constant of force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir decreases as liquid exits the reservoir.

[0017] In some embodiments, the means for variably adjusting the height of the reservoir exhibits variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir. In some embodiments, the one or more springs exhibit variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir.

[0018] In some embodiments, the reservoir is a first reservoir, the apparatus further includes a second reservoir in fluid communication with the first reservoir and configured to refill the first reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and/or structurally similar elements).

[0020] FIG. 1 is a schematic illustrating an embodiment that employs an extension spring used to counter the weight of a reservoir such that the fluid height of the reservoir is constant or otherwise configured/controlled as the reservoir dispenses liquid, thus providing a constant or otherwise known flow of liquid.

[0021] FIG. 2 is a schematic illustrating an embodiment that employs an example of interfacing a reservoir with a spring system by a fulcrum and lever, such that as the fluid height and thus reservoir weight changes, the spring counteracts this change to produce known, specified reservoir height, and thus fluid height and hydrostatic pressure to the dispensing location.

[0022] FIG. 3 is a schematic illustrating an embodiment that produces a known, specified force as objects of the system are submerged in a fluid. [0023] FIG. 4 is a schematic illustrating an embodiment which employs inflatable bladders to turn a conveyor belt and thus produce a known, specified force or torque on the conveyor belt rotators.

[0024] FIG. 5 is a schematic illustrating principles of the disclosure, according to some embodiments.

[0025] FIG. 6 is a schematic illustrating an implementation of one or more embodiments, which allows for a substantially consistent rate of flow, and/or which allows for a larger reservoir to serve as an automatic refill of a smaller dispensing reservoir.

[0026] FIG. 7 is a photograph of an implementation of an embodiment of the disclosure, built according to the principles of FIG. 1.

[0027] FIG. 8 is a photograph of an implementation of an embodiment of the disclosure, built according to the principles of FIG. 1.

[0028] FIG. 9 is a chart of the amount of liquid dispensed from an embodiment according to FIG. 7 and 8. The amount of liquid dispensed versus time is measured according to the height of liquid in a reservoir from a fixed point at the top of the reservoir. The linear relationship illustrates capability for the embodiment to dispense liquid at a constant flow rate.

[0029] FIG. 10 is a chart of the amount of liquid dispensed from an embodiment according to FIG.7 and 8. The amount of liquid dispensed versus time is measured according to the height of liquid in a reservoir from a fixed point at the top of the reservoir. The linear relationship illustrates capability for the embodiment to dispense liquid at a constant flow rate.

[0030] FIG. 11 is a chart of the amount of liquid dispensed from an embodiment according to FIG. 7 and 8. The amount of liquid dispensed versus time is measured according to the height of liquid in a reservoir from a fixed point at the top of the reservoir. The data has been locally averaged to show a more consistent delivery volume versus time. The linear relationship illustrates capability for the embodiment to dispense liquid at a constant flow rate.

[0031] FIG. 12 is a spreadsheet showing calculations for an embodiment according to FIG. 7 and 8.

[0032] FIG. 13 is a spreadsheet showing calculations for an embodiment according to FIG. 7 and 8. [0033] FIG. 14 is a graph of measured versus calculated flow rates for an embodiment of the disclosure built according to the principles of FIG. 1 illustrating the predictability of flow rates for this embodiment.

[0034] FIG. 15 is a graph of calculated (theoretical) flow rate based on the length of a given restrictor tube located at the terminus of a conduit, with a given pressure drop across the restrictor tube, as an example of an embodiment according to FIG. 1.

[0035] FIG. 16 is a graph of measured flow rate based on the length of a given restrictor tube located at the terminus of a conduit, with a given pressure drop across the restrictor tube, for an embodiment build according to the principles of FIG. 1. The graph of FIG. 16 has a similar shape to the graph of FIG. 15, indicating the measured data closely matches theoretical predictions and predictability of system behavior. Thus, users can select a length based on a predetermined flow rate they would like to be achieved.

[0036] FIG. 17 is a spreadsheet showing example calculations for an embodiment employing a packed column to restrict flow.

[0037] FIG. 18 is a spreadsheet showing example calculations for an embodiment employing a packed column to restrict flow.

[0038] FIG. 19 is an annotated photograph of an implementation of an embodiment of the disclosure, showing a bracket designed to fit on the interior of manholes.

[0039] FIG. 20 is a schematic illustrating an example embodiment comprising a ram pump.

[0040] FIG. 21 is a schematic illustrating an embodiment that comprises a flow regulator, which can produce a constant flow of fluid from an intermittent input flow.

[0041] FIG. 22 is an annotated photograph of an embodiment of the disclosure, installed in a location where such an embodiment illustrates one or more useful aspects of one or more disclosures.

[0042] FIG. 23 is photographs before (left) and after six weeks (right) demonstrating the effectiveness of an embodiment for dosing a treatment chemical over a long period of time.

[0043] FIG. 24 is a schematic illustrating a suspended reservoir capable of being refilled by a larger reservoir. In this particular embodiment, the suspended reservoir is suspended underneath a manhole.

[0044] FIG. 25 is a schematic illustrating an embodiment employing a gear.

[0045] FIG. 26 is a schematic illustrating an embodiment employing a pulley. [0046] FIG. 27 is a schematic illustrating an embodiment employing buoyant objects.

[0047] FIG. 28 is a top-down schematic illustrating a manhole bracket suspending a reservoir within a manhole.

DETAILED DESCRIPTION

[0048] Following below are more detailed descriptions of various concepts related to, and embodiments of, inventive methods and apparatus for gravimetric transfer of fluids. It should be appreciated that various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the disclosed concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes. Some disclosures and embodiments discussed herein relate to apparatuses, methods and systems for dispensing liquids and fluids at known flow rates. Some embodiments are configured to provide a constant flow rate, and other embodiments are configured to provide variable flow rates. Some embodiments relate to apparatuses which comprise pumps. Some embodiments relate to apparatuses that dispense liquid without the aid of gravity. The disclosed embodiments can be configured for known flow rates, whether variable or constant, without human intervention during the dispensing, and without any electronic or other feedback system. Rather, the mechanisms and teachings of some embodiments described herein enable virtually any arbitrary flow rate to be set in a flow rate vs. time function. Embodiments can be configured for extended uses, such as for several days or weeks of uninterrupted use at the known, desired flow rate or flow rates. Embodiments can also be configured for shorter and longer flow rate programs using mechanisms described in this disclosure.

[0049] The word "about" or "approximately" when immediately preceding a numerical value means a range of plus or minus 10% of that value, e.g., "about 50" means 45 to 55, "about 25,000" means 22,500 to 27,500, etc. Furthermore, the phrases "less than about a value or "greater than about a value" should be understood in view of the definition of the term "about" provided herein.

[0050] The term "reservoir" as used herein should be understood to mean a container for fluid. In some cases, the reservoir may be a rigid container such as a tank, bucket, drum, cistern, bottle, beaker, etc., and these terms should be understood to be substantially interchangeable in this description. In some cases, the reservoir may be non-rigid, such as a bag, pouch, sack, etc., terms which are also interchangeable for "reservoir" in this description, or the reservoir may be made from a non-rigid material such as a soft plastic, cloth, rubber, etc. In general, the reservoirs referred to in this description are liquid tight, but some embodiments may contemplate the use of reservoirs which allow the seepage or leakage of fluids to or from them.

[0051] The examples provided herein are not meant to be limiting, and it should be evident to one skilled in the art that examples and descriptions are meant to teach the principles of one or more embodiments. The skilled artisan will appreciate that many other features may be added to one or more embodiments, and/or one or more embodiments may be combined with other embodiments, to achieve desired effects.

[0052] Some descriptions herein use the term "fixed point." In general, as used in the descriptions of one or more embodiments, the term "fixed point" should be understood to mean a physical location which is generally immobile relative to the frame of reference. For example, in some situations where an embodiment is placed in a sewer manhole, a fixed point can be any physical point of the manhole, for example the rim on which the manhole cover is placed, the ladder rungs on the side of the manhole, and so forth. In some embodiments, a bracket fitted to the opening of the manhole, and immobile relative to the manhole, can be considered to be a "fixed point," as well. Objects affixed to the bracket could be considered attached to a "fixed point." In this example, the manhole cover is not considered a fixed point when it is moved, but could be considered a fixed point when it is in place covering the hole. In another example, the fixed point could be the inner wall of a space station, rotating in orbit. In this example, the "fixed point" could be considered moving relative to the frame of reference of the earth, but it is fixed relative to the frame of reference of the space station. Some embodiments use the "fixed point" as the frame of reference itself, and in some embodiments, portions of an apparatus move relative to the frame of reference and fixed point, and in some cases, portions of the apparatus are attached to the fixed point while other portions are mobile relative to the fixed point. In some embodiments, portions of the apparatus serve as the fixed point itself. For example, some embodiments contemplate the use of a rigid frame, placed in some instances on the ground, from which a reservoir is suspended by springs. In this example, the reservoir may move relative to the rigid frame, which serves as a fixed point. While some embodiments may use a fixed point as a point of attachment, some embodiments may not, wherein the fixed point serves primarily as a frame of reference. In some instances, a fixed point may in fact deflect by a measurable amount when one or more aspects are attached to or loaded onto the fixed point, so the skilled artisan should understand that a fixed point remains substantially immovable, but not entirely so necessarily. [0053] Dispensing liquids or solids at a known flow rate has myriad applications and uses, and embodiments of the disclosure can be utilized across a wide variety of fields and

technologies. For example, in production processes, the disclosed embodiments can be configured for liquid adhesive that is dispensed at a constant flow rate onto a panel for gluing. In water treatment or sewage systems, the disclosed embodiments can be configured for adding chemicals into the stream, e.g., to decrease foaming, treat solids buildup, reduce odor, change pH, etc. The disclosed embodiments can also be applied to irrigation systems to provide a known flow rate to ensure that crops receive adequate water but without waste runoff. In yet another use, the disclosed embodiments can be operated to dispense one or more materials into an oil well, for example down the back side of an oil well, especially in remote locations, where power supplies are onerous, unstable, and difficult to monitor. Some embodiments comprise a clock, and/or the means to continuously feed, power, energize, charge, or cause movement of one or more devices which tracks time; in some embodiments a constant flow is used to create a measurement of time. In some embodiments, the disclosed apparatuses could be configured as intravenous fluid delivery systems, where a medical fluid is administered to a patient at a known, controlled rate. The disclosed embodiments can also be implemented in grain filling systems or pelletized fertilizer delivery systems where a known flow rate of (typically, granulated or powdered) solids is needed.

[0054] Traditionally, pumping is the chosen method of transferring fluids. A myriad of pump styles and techniques are known. In the case of solids, Archimedes' screw, conveyor belts, and many other mechanical means are used to move solids.

[0055] By contrast, some of the disclosed embodiments can be utilized without pumping, and instead rely on systemic acceleration and/or force, such as gravity, where some reservoir or container holding the liquid or solid is suspended at some height relative to the dispensing location. In some embodiments, the force of gravity on the liquid or solid creates a hydrostatic head pressure at the dispensing location, which forces fluid out and drains the container. While gravity is perhaps the most common situation where constant-acceleration produces the forces required to dispense liquid, other situations exist where another means of external acceleration or force acts on the reservoir of the liquid, causing it to flow. For example, a rotating container can be used to cause liquid to flow due to centrifugal force. In some embodiments, the force of buoyancy on one or more objects, including a reservoir holding the liquid itself, can be transferred to one or more reservoirs to effect a substantially constant flow, as taught herein.

While aspects of the disclosure contemplate the use of non-gravitational external acceleration on the liquid or solids for the embodiments disclosed herein, for the sake of explanation and understanding, the embodiments will generally be discussed where gravity is the source of external acceleration, i.e., gravity-fed systems. The same basic features and functions of the disclosure can be configured for use with non-gravitational systems, and it is to be understood that the use of the term "gravity" herein is encompassing of any systems and/or methods using an external/ sy stemi c accel erati on/force .

[0056] The disclosed embodiments can also comprise a clock or instrument to measure the passage of time. In certain embodiments, since flow of fluid is constant, the quantity of fluid can be used to measure the passage of time. This is a great improvement on water clocks known since antiquity, which either require the constant "topping off," "overflow," or other means of maintenance of a known water level in a vessel; or through careful measuring, calculation, and calibration of the liquid height in a vessel to correlate liquid height to time. In some

embodiments, one or more apparatuses contemplated allow the use of containers of arbitrary shape and size, rather than requiring carefully controlled, measured, designed, or calculated shapes and sizes, in order to measure the passage of time. One or more embodiments serve as an adjunct to known water clocks, for example serving as a constant rate of inflow for a water clock which requires constant "topping off." Some embodiments do not comprise clocks.

[0057] In some embodiments, the systems described can be configured to create a pump. In some embodiments, a constant flow from a reservoir can be used to power a ram pump, also known as a hydraulic ram, which will deliver fluid to a height greater than the initial fluid height in the reservoir. In certain embodiments, the system can be configured to deliver a constant flow to the input of a ram pump, which creates a constant, usually intermittent output flow to a height greater than the initial fluid height of the system. One or more embodiments can be placed in the path of intermittent output flow of fluid exiting a ram pump, which varies with time, to cause the flow of the fluid to become constant at the exit of one or more embodiments. Thus, one or more embodiments can serve as a flow regulator. Thus, in some embodiments, the intermittent flow of a ram pump can be controlled and caused to be constant by integration of one or more embodiments into the flow path of the ram pump. Some embodiments comprise a ram pump. Some embodiments can be used to meter or control the flow of a ram pump. Some embodiments do not comprise a ram pump. One or more embodiments can be configured with one or more fluid devices utilizing the Venturi effect, for example to create a region of vacuum. One or more embodiments contemplate the use of the flow produced by an embodiment as a motive fluid, for example in an injector, well pump, or similar. [0058] The terms "fluids" and "liquids" when used throughout this disclosure are to be understood to include traditional fluids which occupy their container, as well as the terms understood to encompass solids, especially granulated, sintered, powdered, or other solids which can be fed e.g., in gravity systems, as well as the terms understood to encompass slurries, solid suspended in liquid, or other mixtures of liquids and solids. For simplicity, the terms "fluid" and "liquid" are used, generally interchangeably, when describing the various embodiments herein, be it for liquid, solid, or solid-in-liquid systems, or generally for systems where matter can be made to flow by imposition of an external force. In one or more embodiments, "fluid" excludes a gas. As used herein, depending on the embodiment, liquid can include mixtures, including those having a plurality of phases; solutions; suspensions; and/or gels. Embodiments of the disclosure can be configured for liquids of a variety of densities, for example between about 0.06 g/cm³ to about 20 g/cm³ (for example, about 0.06 to about 0.07 g/cm³, about 0.07 to about 0.08 g/cm³, about 0.08 to about 0.09 g/cm³, about 0.09 to about 0.1 g/cm³, about 0.1 to about 0.2 g/cm³, about 0.2 to about 0.3 g/cm³, about 0.3 to about 0.4 g/cm³, about 0.4 to about 0.5 g/cm³, about 0.5 to about 0.6 g/cm³, about 0.6 to about 0.7 g/cm³, about 0.7 to about 0.8 g/cm³, about 0.8 to about 0.9 g/cm³, about 0.9 to about 1 g/cm³, about 1 to about 2 g/cm³, about 2 to about 3 g/cm³, about 3 to about 4 g/cm³, about 4 to about 5 g/cm³, about 5 to about 6 g/cm³, about 6 to about 7 g/cm³, about 7 to about 8 g/cm³, about 8 to about 9 g/cm³, about 9 to about 10 g/cm³, about 10 to about 20 g/cm 3 , about l lg/cm 3 , about 12g/cm 3 , about 13g/cm 3 , or about 13.5g/cm 3 , or any other value or range of values therein). Embodiments of the disclosure can be configured for liquids of a variety of viscosities, for example between about 0. lcP and about 250,000cP, such as about 0.09 to about 0.1 cP, about 0.1 to about 0.2 cP, about 0.2 to about 0.3 cP, about 0.3 to about 0.4 cP, about 0.4 to about 0.5 cP, about 0.5 to about 0.6 cP, about 0.6 to about 0.7 cP, about 0.7 to about 0.8 cP, about 0.8 to about 0.9 cP, about 0.9 to about 1 cP, about 1 to about 2 cP, about 2 to about 3 cP, about 3 to about 4 cP, about 4 to about 5 cP, about 5 to about 6 cP, about 6 to about 7 cP, about 7 to about 8 cP, about 8 to about 9 cP, about 9 to about 10 cP, about 10 to about 20 cP, about 20 to about 30 cP, about 30 to about 40 cP, about 40 to about 50 cP, about 50 to about 60 cP, about 60 to about 70 cP, about 70 to about 80 cP, about 80 to about 90 cP, about 90 to about 100 cP, about 100 to about 200 cP, about 200 to about 300 cP, about 300 to about 400 cP, about 400 to about 500 cP, about 500 to about 600 cP, about 600 to about 700 cP, about 700 to about 800 cP, about 800 to about 900 cP, about 900 to about 1000 cP, about 1,000 to about 2,000 cP, about 2,000 to about 3,000 cP, about 3,000 to about 4,000 cP, about 4,000 to about 5,000 cP, about 5,000 to about 6,000 cP, about 6,000 to about 7,000 cP, about 7,000 to about 8,000 cP, about 8,000 to about 9,000 cP, about 9,000 to about 10,000 cP, about 10,000 to about 20,000 cP, about 20,000 to about 30,000 cP, about 30,000 to about 40,000 cP, about 40,000 to about 50,000 cP, about 50,000 to about 60,000 cP, about 60,000 to about 70,000 cP, about 70,000 to about 80,000 cP, about 80,000 to about 90,000 cP, about 90,000 to about 100,000 cP, about 100,000 to about 200,000 cP, about 200,000 to about 300,000 cP, or any other value or range of values therein. In one embodiment, the density of the fluid is about 1.05 g/cm³. In an embodiment, the viscosity of the fluid is about 10 centipoise.

[0059] Traditionally, constant-acceleration-type systems, for example gravity fed systems, are limited in their applicability due to the changing amount of liquid in the reservoir, and thus changing height of the liquid (changing hydrostatic pressure) relative to the point of dispensing. This effect is apparent to anyone who has used a bottom spout on a beverage dispenser: at first, the liquid flows quickly, but as the container becomes emptier, the flow rate is much lower. This effect is described by Torricelli's law, which is a special case of Bernoulli's principle. One or more embodiments herein is aimed at addressing this effect for useful systems which can dispense a constant, or controlled flow of liquid. In some embodiments, the flow of liquid is constant regardless of how much fluid is left in the container. In some embodiments, the flow increases as the container empties, which is the opposite of the beverage dispenser/Torricelli's law effect described above, and which is surprising, unexpected, and potentially useful.

[0060] The embodiments disclosed herein relate to dispensing systems of liquids, for dispensing at a known flow rate. Other embodiments specify tools and components to dispense a liquid at a constant flow rate. Still other embodiments specify components to dispense a liquid at variable flow rates. These effects are achieved with the various designs and teachings disclosed herein.

[0061] One or more aspects of the disclosure utilize a constant external acceleration acting on components, for example gravity near the Earth's surface (e.g., about 9.8m/s²). While the embodiments described herein may be most immediately and widely used with the Earth's gravity as the external force, any external acceleration can be used with appropriately configured components of the disclosure, as taught herein, such as an acceleration between about 0.1 to about 0.2 m/s², about 0.2 to about 0.3 m/s², about 0.3 to about 0.4 m/s², about 0.4 to about 0.5 m/s², about 0.5 to about 0.6 m/s², about 0.6 to about 0.7 m/s², about 0.7 to about 0.8 m/s², about 0.8 to about 0.9 m/s², about 0.9 to about 1 m/s², about 1 to about 2 m/s², about 2 to about 3 m/s², about 3 to about 4 m/s², about 4 to about 5 m/s², about 5 to about 6 m/s², about 6 to about 7 m/s², about 7 to about 8 m/s², about 8 to about 9 m/s², about 9 to about 10 m/s², about 9 to about 10 m/s², about 10 to about 20 m/s², about 20 to about 30 m/s², about 30 to about 40 m/s², about 40 to about 50 m/s², about 50 to about 60 m/s², about 60 to about 70 m/s², about 70 to about 80 m/s², about 80 to about 90 m/s², about 90 to about 100 m/s²,, or any other value or range of values therein. For example, a constant external acceleration could be employed using a rotational motion system, within a centrifuge and/or the like. In some embodiments, varying external accelerations may be useful for providing one or more benefits to one or more systems described herein. For example, the intermittent application of an acceleration to a volume of fluid may produce intermittent increases or decrease in flow from this fluid, which may be useful in some embodiments.

[0062] The force exerted by any object in gravity is proportional to the mass of the object and the gravitational acceleration. The 'weight' of an object is simply the force exerted by the mass of the object given the acceleration due to gravity; while weight and mass are often used interchangeably, one or more aspects take advantage of this distinction.

[0063] For many spring systems (including without limitation compression springs, air springs, bias springs, coil springs, compression springs, extension springs, helical springs, leaf springs, press springs, disk springs, gas springs, torsion springs), as well as elastic materials, the force exerted is governed by Hooke's law, which states:

[0064] F = kX

[0065] Where F is the force exerted by the spring system, k is the spring constant, and X is the displacement of the spring along some vector relevant to the mode of action of the spring. For example, in an extension spring, X is the displacement along the length of the spring as the spring gets stretched.

[0066] For convenience and ease of understanding, the terms "spring" or "spring system" are used herein to describe any mechanism with elasticity that obeys Hooke's Law. While one or more aspects can employ a single extension spring, it should be understood that "spring system" encompasses any device obeying Hooke's Law, or corollary thereof. For example, an elastic band or rubber rod can obey Hooke's law. In another example, a plurality of springs can have a combined "spring constant." In yet another example, one or more springs can be combined with one or more elastic member to create a combined spring constant. One or more embodiments described herein contemplate using a plurality of springs to create a selected spring constant.

[0067] In some embodiments, non-Hookeian behavior is also desirable and can be utilized appropriately. For example, as described below, the buoyant force on a fully submerged object remains essentially constant regardless of how far under the surface the object is; therefore, this object can provide an essentially constant force if coupled to an external system. In some embodiments, therefore, the term "force system" is used herein to generally refer to one or more portions of an apparatus that produce the desired effects. In some embodiments, the "force system" comprises one or more springs or spring systems. In some embodiments, the "force system" comprises a buoyant object acting on one or more portions of an embodiment. In some embodiments, the "force system" can comprise a combination of different systems described herein, such as spring systems, buoyant objects, and so on. In some embodiments, the balance of a constant force system along with a spring system which obeys Hooke's law, as described hereinabove, may be used to provide the needed effects. In embodiments where springs or spring systems are used, any convenient material is contemplated, and the materials are not meant to be limiting in this description. For example, in a sewer system environment, we have found it to be desirable to use stainless steel springs to avoid effects that the corrosive environment may have on other materials. In other environments, other materials can be selected to suit the conditions, but which still provide the needed force as described herein. In one or more embodiments, the use of one or more attenuators on a force system can be desirable. For example, a reservoir suspended by a spring system may tend to bounce up and down and swing side to side if moved; this behavior may cause undesired effects. In such cases, a device may be used, herein termed an "attenuator," which limits the unwanted behavior, for example, by limiting the speed that the reservoir can move, or restricting the degrees of freedom of the reservoir. For example, the reservoir may be connected to a fixed point with one or more gas pistons, which limits the speed that the reservoir can move, e.g. along the axis of the gas piston. In another example, the reservoir may be articulated upon rails or guide channels used to allow movement in a limited number of directions, e.g. up and down, which limits swinging. Such guide channels may provide friction that limit the speed which the reservoir moves. In embodiments in which an "attenuator" is used, it is generally the case that any force which the attenuator applies should be accounted for in the calculations described herein, or that the force of the attenuator does not affect the calculations, so as not to change the desired outcome of the apparatus, namely, in some embodiments, to produce a controlled output of fluid from one or more systems. In some cases, an attenuator is not used, and in some cases, an attenuator is not desirable.

[0068] It should be appreciated by a skilled artisan that some embodiments therefore operate by the balance of two forces. Since force is simply a measurement of acceleration of an object accounting for its mass:

[0069] F = ma, [0070] Where F is force, m is mass, and a is acceleration, it should be appreciated by skilled artisans that some embodiments operate by the balance of the effects of acceleration with some force system. In some embodiments, the two forces in play are that of gravity and a spring system. In some embodiments, the two forces are centrifugal force and buoyancy. In some embodiments, two or more force systems may act on two or more forces or accelerations.

[0071] Therefore, the action of spring systems on an object of given mass will produce a displacement when a force or acceleration (such as gravity) is acting on that mass. For example, the displacement of a weight suspended from an extension spring is linearly proportional to the weight of the object. This is the basis of spring-type scales, which measure deflection of the spring to ascertain weight of an object. Because humans most often work near the surface of the earth with essentially identical gravitational pull independent of location or elevation, spring manufacturers often specify not a spring constant, k, but a weight per distance value for the spring. This is because weight is force, as described above, and the amount that a spring is displaced produces a force proportional to that distance. Thus, for example, an extension spring manufacturer might specify that a given spring has a "rating" of lOlbs per inch. This means that it will take lOlbs to stretch the spring one (1) inch, and since springs obey Hooke's law, which describes a linear relationship between the spring constant and the distance traveled, 201bs to stretch it two (2) inches, and so on. Looking at this another way, this same spring can be used to measure a weight, or mass, by observing how much it stretches when attached to that weight; for example, a three (3)-inch stretch means the object weighs (has a mass of) 30 lbs., etc.

[0072] A liquid in a reservoir has a mass associated with the density and volume of the liquid. Within the reservoir, the liquid exerts a pressure on the reservoir which varies with the height of the liquid in the reservoir. The same volume of liquid, therefore, can have varying pressures depending on the shape of the reservoir. For example, the pressure exerted by a tall, narrow column of water on the base of the column is different than when the same volume of water contained in a wide, shallow, disk-shaped reservoir. However, in any case, the pressure exerted by the liquid on any given area on the container is proportional to the height of the liquid above that area of the container. For example, drilling holes at various heights in a tall cylinder containing water will result in water shooting out of the holes at increasing distances farther down the column.

[0073] Therefore, in a rigid (fixed size and shape) container, if the level of a liquid is maintained relative to some area of the container, the pressure of the liquid on that area will be constant. This is independent of the shape of the container, and only dependent on the height of the container. For example, a cylindrical column of 1 cm in diameter filled to 10 m with a liquid will have the same pressure at the bottom as a cylindrical tank 10m in diameter filled with the same liquid to 10m height, despite the latter containing substantially more liquid and more overall mass. Moreover, the shape of the container is irrelevant; any arbitrary shape will produce the same pressure given the height of the same liquid. Thus, a container, comprised of a 1cm diameter tube of lm length, connected to an end of a reservoir 10m in diameter and 8m height, connected at the other end of the reservoir to a 1cm diameter tube of lm length (i.e. a thin column-thick column-thin column configuration, which has the appearance of the inverse of a dumbbell, total 10 m), will have the same pressure of the liquid at the bottom as a 1cm tube 10m in height filled with liquid, or a 10m column 10m in height filled with liquid.

[0074] Additionally, a description of the siphoning effect is provided to illustrate one or more aspects of some embodiments. A conduit completely filled with a liquid, connecting two containers with some amount of liquid in them will equalize the pressure between the two containers. In a basic example, if a tube containing air is connected with a water-tight connection at one end to the bottom of an elevated, open container, and at the other to a lower, open container, pouring water into the elevated container will result in water flowing into the lower container until the liquid height in both containers is identical. While this may be intuitive (since in this case the tube acts similarly to a funnel, i.e., water simply flows with gravity), what provides a surprising outcome (if one has never seen a siphon before) is to invert a tube while it is filled with water, and place each end under the liquid level in two containers that each have at least some water in them, such that the tube is now shaped as an upside-down "U", extending above the two containers. So long as the tube remains filled with water, the height of the containers relative to each other can be changed, yet the water level will remain the same relative to an external height, in both containers. For an illustration of this effect, the reader is referred to FIG. 5. For one or more aspects herein, the relevant effect is that a conduit can be of arbitrary shape, size, and height relative to the two containers; the liquid level will equilibrate throughout the system depending on height of the liquid in both containers. If the conduit is flexible and/or has slack associated with it, the two containers can be moved relative to each other within the confines of the flexibility of the conduit, and so long as the conduit remains filled and terminates under the liquid level of both containers, the liquid level between the containers will remain identical relative to an external height.

[0075] Therefore, by choosing a spring system acting on a container of liquid with a siphon terminating at a fixed external height, such that the height of the liquid in the container relative to a fixed external height remains constant, the pressure of the liquid in the siphon at a fixed external height will remain constant. One or more embodiments utilize a spring system which has a weight-to-displacement rating which matches the ratio of the weight of the container when empty versus full, to the height of the container full versus empty. While use of a siphon may be convenient, the same effect can be produced using a tube connected with a liquid-tight seal below the surface of the liquid, allowing liquid to enter and pass through the tube, said tube then terminating in an open configuration at some fixed height below the liquid level. For example, a tube connected to the bottom of a container by a bulkhead fitting with the far end of the tube held at a fixed height. Such an arrangement may be convenient to avoid the need to prime the siphon, i.e. pre-fill it with liquid. Since liquid flow is a function of pressure drop across a given conduit (e.g. hole, tube, opening), such a system results in a constant flow of liquid from said reservoir until equilibrium has been reached or the reservoir empties. Thus, such a device will allow for constant flow to or from the reservoir depending on the terminus of the tube until either the tube has the same liquid level as the reservoir, or until the reservoir is empty.

[0076] In an illustrative example, a rectangular prism shaped bucket contains a liquid with a density of 1 g/cm³ which equals 1 g/mL. The bucket has inner dimensions of 10cm x 10cm wide, and 50 cm height. Thus, each vertical cm of the bucket contains:

[0077] 10cm x 10cm x 1 cm = 100cm³

[0078] or 100 mL of liquid. Thus, neglecting the weight of the bucket itself, each one (1) vertical cm of the bucket weighs precisely

[0079] 100cm³ * lg/cm³ = lOOg.

[0080] If this bucket is suspended from an extension spring which, un-extended, is 10cm in length, and which has a rating of lOOg/cm, then regardless of how much of this liquid is in the bucket, the height of the liquid relative to the structure from which the bucket is suspended will remain constant. For example, if the bucket is full, and it contains

[0081] 10 cm x 10cm x 50cm = 5,000cm³

[0082] The mass (again neglecting the weight of the bucket and spring) will be:

[0083] 5,000cm³ * lg/cm³ = 5,000g

[0084] Which produces a displacement of the bucket:

[0085] 5,000g ÷ lOOg/cm = 50cm [0086] So, the top of the bucket, which is full, will be 50cm below the un-extended spring height, which means the top of the liquid is 50cm below the un-extended spring height, which was 10cm, or 60cm total below the fixed means of suspension.

[0087] Now assume that the bucket is emptied until only 10cm of liquid remains in the bucket. This will have a mass of:

[0088] 10 cm x 10cm x 10cm = 1,000cm³

[0089] 1,000cm³ * lg/cm³ = l,000g

[0090] Which will cause a displacement of the spring:

[0091] l,000g ÷ lOOg/cm = 10cm

[0092] Now, the top of the bucket will be 10cm below the un-extended spring length, which is 10cm, so the top of the bucket is now only 20cm from the fixed point. However, the liquid in the bucket is 40cm below the top of the bucket, which means that the liquid is still 60 cm from the point of suspension. Similar calculations can be performed to demonstrate that, regardless of the amount of liquid in this bucket, the height of the liquid relative to the fixed external point will remain constant.

[0093] If at the bottom of this same bucket, a connection is made to a flexible conduit or tube so as to allow liquid to enter the tube, and this tube is dangled below the bucket, with some slack, or using a flexible tube, or an accordion-style conduit, to accommodate the vertical movement of the bucket (i.e., movement up and down), and terminated at a fixed point relative to the suspension point of the spring and bucket, the height of the liquid relative to the termination point of the tube will remain constant. In other words, the termination point of the tube is fixed relative to the suspension point, and since we have established that the liquid level relative to the suspension point is fixed, the liquid level at the termination point of the tube is also fixed.

[0094] Accordingly, following the above, the flow rate of the liquid out of the bucket, through the tube, will remain unchanged even as the bucket empties.

[0095] In contrast, if the same bucket and tube were suspended from a fixed location, the terminus of the tube fixed again relative to this location of suspension, but no spring was present, there would be a 40cm difference in height of the liquid when the bucket was filled versus when only 10cm of liquid height remained. Thus, the height of the column of liquid would change, which causes the pressure of that column at the fixed tube terminus to change, which would change the flow rate of liquid leaving the tube. [0096] It should be noted that a siphon can substitute for the tube in the above example and one or more embodiments, producing the same effect. So long as liquid is maintained in the siphon, the flow rate leaving the tube will remain unchanged. Such a use of a siphon obviates the need for a physical connection between the tube and the reservoir.

[0097] In some embodiments, the weight of the container, absent the fluid, does not affect the ability for the system to dispense a fluid. This is because the weight of the fluid and the height displacement of the container are the considerations for determining the spring constant. On the other hand, the springs must be sufficiently rated to handle the weight of the container, especially when full, as well as to begin to deflect when fluid is present in the container. Springs are often rated to have a minimum deflection weight, the weight below which the spring doesn't stretch or compress. For a constant hydrostatic pressure, or liquid height, the spring constant should match the difference in weight between the fluid when full in the reservoir, versus when the reservoir when empty, along with the height of the reservoir when full versus empty, assuming the reservoir has a substantially invariant cross sectional area along its vertical axis. Systems using reservoirs with variable cross-sectional area along the vertical axis are

contemplated and discussed hereinbelow. The weight of the reservoir will therefore be subtracted out in the calculations and can be ignored for purposes of calculating spring constant. In addition to considering the spring constant, the total weight rating, and minimum deflection, the difference between the extended and retracted length of the spring, for a constant hydrostatic head pressure system, should be at least as long as the height of the fluid in the container. This is because the spring, for a constant hydrostatic head pressure, should act upon the fluid for the length of the distance from the fluid at the top of the reservoir to the bottom.

[0098] In certain embodiments, the terminus of the tube may be restricted by one or more means, and for one or more reasons, described hereinbelow. In some cases, restriction can make it difficult or time-intensive to prime (fill with fluid) the tube once liquid is added to or connected with the fluid of the container. Thus, a separate tube can be added to the point of restriction using a "tee" or similar type of connection. This separate tube can be chosen in some embodiments to have a larger diameter than the restriction. The other end of this tube can be brought up above the height of liquid, or, conveniently, to the top of the container or reservoir. Thus, once liquid is added, it can easily flow into the tube below the container, and into the added tube to re-equilibrate with the fluid height, as described above. Since this added tube will have the same liquid level as the rest of the container, it does not change the flow rate of fluid from the container, which allows the operation of the system in a more convenient manner. In embodiments using a transparent or translucent tube, an additional advantage is convenient visualization of the liquid level in a reservoir, which may be opaque and/or covered.

[0099] Although the numbers above were chosen for illustration, it should be noted that similar calculations can be done to account for liquids of various densities, the weight of buckets, springs, tubes, and so forth, various container shapes, and/or the like. These calculations inform a spring constant or weight-per-unit-displacement rating of a spring system. It is notable that said spring constant or weight-per-unit-displacement rating can be distributed to more than one spring, or otherwise linked through mechanical advantage/disadvantage so that the desired rating for a particular configuration is provided.

[00100] Thus, one or more aspects of the disclosure allow for a constant flow of liquid to be delivered from a reservoir without any pumps, using a constant acceleration (e.g. gravity) acting on that reservoir and a spring system to change the height of the reservoir proportional to the volume of liquid in the reservoir. The constant acceleration can be provided in a centrifugal system, gravity, or any other means, and the spring system could be accomplished with direct or indirect linkages to some system obeying Hooke's law as described above. In another

embodiment, a spring system can be chosen in which the liquid height increases or decreases as the liquid level decreases or increases in the reservoir, creating increasing or decreasing flow rates with time. In another embodiment, a variable flow could be produced using a system which does not linearly obey Hooke's law. For example, constant-force springs are known which have a constant return force independent of displacement.

[00101] The use of one or more aspects of the disclosure in dispensing liquid materials is provided, and in some implementations, such a system could work with solids, especially granular, powdered, or otherwise loose solids, as well as solids-in-liquids, such as slurries or suspensions, or in any case where a medium can be made to flow like a fluid, be it Newtonian or non-Newtonian. Also, where the material is being dispensed into environments with different temperatures and pressures, one or more embodiments can be configured accordingly.

[00102] Various machines, linkages, gears, pulleys, levers, wheels, inclined planes, wedges, screws, and combinations thereof, can be used to transmit the weight of reservoirs to force systems. While an embodiment employs an extension spring directly linked to the reservoir, and used as the force, the linkage of a reservoir via intervening mechanisms to any constant or variable force system is also possible. For example, one embodiment can use a lever, which on one side would carry the reservoir, and the other would impinge on a compression spring. As the reservoir dispenses liquid, the height of the reservoir would change since the weight changes and the force on the spring through the lever changes. Similarly, a pulley system could be used to gain a mechanical advantage so that springs with lesser or greater k constants can be used, and/or greater or lesser lengths of action, weight rating, etc. Alternatively, an elastic member can be deformed as a way to provide a variable or constant force, counteracting the weight of the reservoir.

[00103] One or more embodiments can use two reservoirs. As illustrated in FIG. 6, an upper reservoir, elevated relative to a lower reservoir, feeds the lower reservoir based on a float valve in the lower reservoir. Once the liquid level drops below a certain specified height, the valve activates and the lower reservoir re-fills to a designated/specified height. Although the hydrostatic pressure of the lower container may not be entirely constant since there is a small difference between the fluid height just after the valve has been actuated and just before it is actuated, the hydrostatic pressures are known and can be kept within a reasonable percentage of a known flow rate by appropriate adjustment (high-low levels) of the float valve. One advantage of such embodiments is that no springs or other force systems are required. Two-reservoir-float- valve embodiments can be combined with spring systems, and in some embodiments, combining the two systems allow for better control over flow and redundancy against failure. For example, in one or more embodiments, an elevated, larger reservoir can be coupled by a fluid passage, e.g. tube, into a lower, smaller reservoir. The tube terminates in a float valve, which ensures the smaller reservoir contains liquid, so long as the larger reservoir can supply it. In this example, the smaller reservoir is actuated by a spring system, so that it delivers a constant flow of liquid. This example describes an embodiment which allows for a smaller, more easily handled spring- based delivery system to be used, but with the advantage that the larger reservoir is the only one that requires refilling, which is much less frequent than if only the smaller reservoir was used. For example, such an embodiment may be conveniently used in a sewer system, whereby a smaller, spring-actuated reservoir (e.g. a 5-gallon bucket) is placed below grade in a manhole or other access point, and the larger, elevated reservoir (e.g. a 55-gallon drum) placed at or above grade so that it can drain (when the float valve opens) into the smaller reservoir. An example of such an embodiment is shown in FIG. 24.

[00104] Other embodiments utilize buoyancy to create a force effect. The force on a buoyant object increases as the object is submerged in a fluid, but then remains essentially constant for the fully submerged portion of the object, or once the object is fully submerged. For example, submersion of an air-filled hollow rubber ball requires increasing force as more and more of the ball is submerged, but once fully submerged, the force required to push it farther below the liquid's surface is essentially unchanged. One change of the buoyant force is due to contraction of the air in the ball at higher pressures found in deeper water; this effect can be negated with a sufficiently rigid object such as a pontoon or barrel. Other buoyancy force changes can be due to the slight compressibility of some liquids at various pressures, the change of density of liquid at the cooler temperatures found at depth, variation in composition (e.g., salinity) at depth, and so on, but ignoring these factors, the buoyant force on a submerged object is unchanged with depth. On the other hand, for a partially submerged object, the buoyant force on the object increases as the object is increasingly submerged. Partially submerged objects can therefore obey Hooke's law, and be used in one or more embodiments, as described above. Thus, by appropriate selection of one or more buoyant objects (of arbitrary shape and size) in a chosen media allows for a known force of varying force, constant force, or some combination thereof to be produced. Linkage of these objects to one another and to some outside point allows for application of the force as desired for a particular implementation. For example, a string of hollow cylinders separated at intervals centered coaxially along a slim, dense, rigid rod, while being immersed in a fluid, has a force versus depth curve or plot (where depth is measured similarly to displacement, akin to the X in the above Hooke's law equation) that has a positive slope followed by a flat portion, followed by a positive slope, and flat portion, and so on, where the cylinders represent the positive slope as they are being submerged, and the flat portion the central rod connecting and spacing out the cylinders as each one becomes fully submerged. Especially when combined with a reservoir or vessel known flow rate, the string of hollow cylinders configuration can be useful, for example, in dispensing liquids at various times during a day, or at the same time on several days, etc. It should be clear to those skilled in the art that this example is not meant to be limiting, and that other configurations can be chosen to provide configurable forces, and when connected to a reservoir, configurable flowrates.

[00105] In yet other embodiments, a series of bladders can be connected to a conveyor belt or the like submerged in a liquid, oriented such that as the bladders are inflated on one side of the conveyor belt, the buoyant force created causes the belt to turn. Once the bladders reach the other end of the belt, they can be emptied of the gas (or liquid) used to inflate them, such that as they are pulled back down through the liquid, they are not as buoyant as those bladders inflated on the other side of the mechanism. In some embodiments, the bladders are replaced with inverted cups, into which gas can be pumped to displace the liquid, thus making the cup buoyant and pulling the conveyor belt along. Once the cup reaches the distal end of the conveyor belt, since it is fixed to the belt, it turns so the cup opens upward and can re-fill with liquid as it goes back down through the liquid. Such systems could produce a constant force on the conveyor belt, or constant torque on the pulleys to which the conveyor is attached.

[00106] Other embodiments utilize variably shaped reservoirs, which are in some

embodiments attached to the spring systems described above. Since the height of the reservoir suspended by a spring system as described herein is dependent on the mass of the reservoir, and the mass dependent on the shape and volume of the reservoir, arbitrarily shaped reservoirs can be employed whose height-weight ratio changes throughout the reservoir. For example, a reservoir can be constricted in the middle to create a dumbbell-shaped reservoir, and such a reservoir dispenses liquid at one 'end' of the dumbbell at the rate set by the spring system (per the above calculations), then at a lower rate in the 'handle' portion (since the loss of some liquid does not change the mass as dramatically as in the 'end' portion, and thus the spring system does not pull the container up sufficiently to maintain the height of the liquid), then again at higher flow rates at the other 'end.' These reservoirs can be shaped so that the dispensing flow rate changes at a specified rate or rates over the course of time that the reservoir is full.

[00107] The various spring/force/acceleration systems described herein can be combined with the various shaped reservoirs to produce particular flow rates. The flowrates of such containers can be calculated with equations similar to those outlined herein, and empirical measurements can also be taken to produce the effects desired.

[00108] In some embodiments, it may be useful to limit the flow of the liquid leaving a reservoir in one or more aspects. For example, it may be desired to dispense a liquid from a reservoir into a sewer system over the course of several days, in order to treat said sewer system. In some embodiments, the terminus of a tube leading from a reservoir can be only slightly below the liquid level of the reservoir to create a smaller hydrostatic pressure than if, for example, the tube was placed far below the reservoir. In some embodiments, the flowrate of a liquid can be controlled by selecting the height of the terminus of a tube leading from a reservoir, relative to the liquid height in the reservoir. In some embodiments, such a method of flow control is not suitable, so other disclosures provide a solution as described below.

[00109] A variety of flow restriction devices are contemplated, such as an obstruction or narrowing of the passageway through which liquid flows. While in certain cases, using a valve, for example gate valves, ball valves, needle valves, etc., or creating a "bottle-neck" within a flow path, or restricting or pinching-off the tube leading from one or more embodiments can create a lowered, but still constant flow rate, at times the liquid being dispensed is not suitable for flow through such an occluded passage. For example, some liquids behave thixotropically, in other words, have a low viscosity at high flow or shear, but as flow or shear is decreased, the liquid increases in viscosity and further slows or even occludes the flow. Other reasons that a

"bottleneck" may not be a suitable restriction flow method is that some liquids contain fine particulate that can clog the opening, or liquids with high salt levels can evaporate as it flows out of the opening, causing salt deposits which further restricts the opening and decreases the flow rate. We have tested and witnessed directly both salt buildup and solids plugging during our testing of restrictor systems using valves (including but not limited to pinch valves, needle valves, ball valves, gate valves, diaphragm valves, butterfly valves, plug valves, etc.) and restricted openings. One example of this effect is freezing of liquid on the surfaces of restricted openings can cause a buildup of frozen liquid, eventually further occluding the opening; this effect can be exacerbated by the change of composition of a liquid as it evaporates, freezes, or otherwise contacts the outside environment. As another example, dispensing a liquid into an environment which contains vapors which can dissolve into the liquid and interact with one or more compounds in the liquid, can create difficulties when obstructed passageways, such as valves or narrowed terminus, are used. Thus, when lowered flow rates are desired, simply restricting the terminus of the conduit, or restricting the conduit somewhere away from the terminus, may not suffice to produce a constant flow rate. There are several new teachings and components for overcoming this difficulty discovered and which are disclosed as one or more aspects of one or more embodiments.

[00110] As described above, one embodiment produces a constant liquid height, and therefore hydrostatic pressure, especially at the terminus of a conduit, regardless of how much liquid may be in the container. On the other hand, by using varied spring systems with varied spring constants, the height of the liquid can be gradually increased with time, which therefore increases the head pressure of the liquid. In the case where the terminus of the conduit slowly narrows over time, due to plugging or accumulation of solids, for example, an increased head pressure can counter the effect of slowing flow that this opening would otherwise have. In other words, while the passageway of exit or terminus of the system might be increasingly occluded with time, an increase in head pressure of the liquid can force liquid through this passageway and the overall flow rate will remain unchanged. In some embodiments, a system may be designed to create high pressures at intermittent intervals to unclog any occlusions. After such a spike in pressure, the pressure would return to a lower value to continue liquid dispensing at a predefined rate.

[00111] Another option for overcoming a decreased flow rate for reasons described above and/or others is to instead terminate the conduit in a long tube or conduit. The wider a tube, the less likely there is there will be a plug, but also the less resistance to flow, so that wider tubes require more length to restrict flow appropriately. On the other hand, more narrow tubes can be more susceptible to clogging, but do not require as long of a length to cause a significant restriction of flow. We use the term "restrictor tube" and/or "tube" herein, but it should be clear that restrictor tubes can comprise any form of passageway for liquids, including but not limited to tubes, hoses, pipes, sluices, and/or conduits. The restrictor tube can also comprise the conduit leading from a reservoir, or be operatively coupled to the conduit leading from a reservoir in one more embodiments. Knowing the head pressure of the restrictor tube, i.e. the hydrostatic pressure based on the reservoir's height relative to the output of the restrictor tube, the termination pressure of the restrictor tube (for example, atmospheric pressure, although increased pressures or vacuums are also contemplated), the restrictor tube length, diameter, and roughness, a given flowrate can be selected knowing the density, viscosity, and friction loss coefficient, of the liquid. Alternatively, absent one or more of these measured quantities of the system and liquid, a flowrate can be optionally estimated using first approximations of the system (for example, friction loss, viscosity of the liquid and roughness of the tube), and/or and a given tube material and diameter selected. The actual flowrate based on the restrictor tube selected can be measured, and the length of the tube can be changed, for example by cutting the tube, or appending additional lengths, and the flowrate determined. This provides an empirical method for creating a dispensing system with a desired, precise and constant flow. Indeed, empirical measurements and calibrations can overcome many of the effects which are difficult to calculate for real world objects, such as the inner surface roughness of a given tube with respect to a given liquid, which can have significant effects on flow rate, and which may not be available in datasheets from manufacturers of tubes. For example, the inner roughness of a tube may be one value that can be referenced from a manufacturer when water is used, but when a different liquid is employed, the quoted roughness value can be substantially different. Non-circular tubes could be used as well as non-tubular restrictors, such as channels within a solid structure. In any case, for many systems, the theoretical flow rates are calculable, while empirical flow rates can be selected in a similar fashion to the tube method described above.

[00112] Some embodiments can comprise a plurality of restrictor tubes. In some embodiments the tubes are connected in series. In certain embodiments, the dimensions and materials of the serially-connected tubes can be changed to create a known restriction. In certain embodiments, a series of tubes can be connected in series by three-way valves, valves with more than three ports wherein at least three ports are used, or by two cutoff valves. In certain embodiments, opening and closing of one or more valves can create a flow path of selected length. In some

embodiments, an arbitrary length of tube can be chosen based on a significantly smaller subset of tubes which comprise the flow path. It should be clear to a skilled artisan that by changing the length of a tube, the pressure drop across the tube can be changed, which changes the flow rate of fluid through the tube; therefore, by changing the overall length of a flow path comprised of tubes, an arbitrary flow rate can be selected based on a given head pressure, hydrostatic pressure, or pressure drop. For example, any integer length of tube from 1-38 meters can be created based on combinations of single tubes of length one (1), two (2), three (3), four (4), eight (8), as well as two ten (10) meter lengths. Table 1 below shows how proper connection of combinations of these tubes can provide any length of tube from one to thirty eight (1-38) meters:

Table 1

[00113] For example, in one embodiment, a series of six (6) three-way valves can be connected, one between each of the seven lengths of tube in Table 1, such that each length is either included in the flow path, or not. Proper selection of which tube is in the flow path (denoted by the X in the corresponding column and row in Table 1) provides an overall path length of the desired length. Thus, the flow rate through these tubes can be controlled and changed conveniently.

[00114] Some embodiments can comprise a plurality of restrictor tubes. In some embodiments the tubes are connected in parallel. In some embodiments, the tubes terminate in the same location; in some embodiments, the tube terminate in separate locations. In some embodiments, therefore, a selected flow can be chosen by using all or a set of restrictor tubes terminating in a given location. For example, if ten (10) identical tubes which each will deliver a flow of 1 mL/min based on a certain head pressure are used, then any integer flow rate from 1 to lOmL/min can be selected by simply using as many tubes as are needed in a parallel manner. In certain embodiments, the tubes can be connected to individual valves to select the proper number of tubes as required. In some embodiments, as above, the tubes can have varying delivery flow rates, and combined in parallel in various combinations to achieve a desired flow rate. In some embodiments, tubes can be routed to separate locations for distribution of a fluid to disparate locations. In some embodiments, tubes can be configured as described herein to deliver different flow rates to different areas. In some embodiments, the tubes can be routed to the same location, for distribution of a fluid in a single area.

[00115] Other embodiments can employ a tube packed with a solid as a restrictor to flow. Said tube can be selected for length and diameter, as well as cross-sectional shape (circular, oval, square, of varying dimensions etc.), depending on the implementation. The packing material can be pelletized (e.g., buck-shot), filamentous (e.g., cotton wool), or any other form that allows fluid to flow through and around the space of the solid. In some embodiments, a constant particle size is used to pack the tube, wherein the Kozeny-Carman equation can be used as a first calculation of pressure drop and flow rate. In some embodiments, various-sized particulates can be used to pack the tube. In some embodiments, empirical measurements can be taken of a packed tube to determine pressure drop versus length of the tube. This restrictor can be combined with other restrictors (e.g., as described herein and/or known from the relevant literature), as well as appended onto the flow mechanisms described herein or other like components for dispensing liquids.

[00116] In yet another embodiment, the viscosity of the fluid being dispensed can be changed by chemical means. For example, xanthan gum is a widely available material that is used to thicken foodstuffs or other chemicals, and can be utilized, and/or other thickeners and/or additives can be utilized. Such embodiments can be combined with or used instead of the restrictors described herein. For example, if a non-viscous material is to be dispensed, or the flow rate of a material would call for an impractical, long restrictor, or the material contains particulates which would occlude narrow restrictors or packed columns, the viscosity of the material being dispensed can be increased with an inert or possibly active ingredient. For example, it is known that the viscosity of sodium hydroxide solutions increases with

concentration of sodium hydroxide. Thus, a system dispensing sodium hydroxide solution can be effectively tuned by diluting or adding more sodium hydroxide into the system (depending on the dispensing needs) or by using an inert thickener (again depending on the application).

Such embodiments and systems require no electricity, no power, no external feedback controls, no pumps, and no intervention. For situations where a constant delivery of liquid with respect to time is required, one or more aspects provide an elegant means for dispensing the liquid, especially where the area of application is hard to access, dangerous to access, and/or benefits from not having electrical control mechanisms (e.g., in a flammable environment). In some embodiments, systems can be combined with powered, pneumatic, hydraulic, mechanical, or electronic feedback systems for additional control.

[00117] Numerous advantages of one or more aspects of the disclosure include the ability to create a constant flow. Some embodiments enable a known but variable flow. Some

embodiments enable flow to be chosen/specified/programmed and liquid dispensed without any operator intervention. Some embodiments describe systems with no moving parts in the flow path of the liquid and which therefore reduce clogging and/or corrosion of systems. Some embodiments describe systems which require no electricity, no external power source, no external feedback controls, no pumps, and no intervention. For situations where a constant delivery of liquid with respect to time is required, one or more aspects provide an elegant means for dispensing the liquid.

[00118] FIG. 1 shows a perspective view of one embodiment. As shown in FIG. 1, to a fixed point 110 is connected an extension spring 112 from which is reservoir 114 containing a liquid

116. From said reservoir 114 leads a conduit 118, through which the liquid 116 is delivered at some fixed height 119. In some embodiments, conduit 118 is flexible (i.e. can stretch along the conduit axis) or is accordion-like and can collapse and expand, or contains slack to allow reservoir 114 to move relative to fixed point 110, but such that the distance or height between the terminus 119 of conduit 118 and fixed point 110 is constant, thus making the terminus 119 of conduit 118 a fixed height as well. In other words, although reservoir 114 is acted upon by gravity and extension spring 112 and therefore can move vertically, the height of the output of conduit 118 does not change relative to fixed point 110. Optionally, a flow restriction device, aperture, valve, or restrictor 120 is connected to conduit 118 to reduce flow of liquid 116. In some embodiments, restrictor 120 is a narrow tube chosen so that the pressure drop of liquid across it is known. In some embodiments, extension spring 112 has a spring force constant equivalent to the change of weight of the reservoir with each infinitesimal height of liquid 116 in the reservoir, which produces a constant height of liquid in reservoir 114 relative to fixed point 110 and fixed height 119. In such embodiments, the head height and therefore hydrostatic pressure of liquid 116 relative to fixed height 119 is invariant, thereby producing an invariant flow rate of liquid 116 from reservoir 114. In other embodiments, various spring constants are chosen to produce varied spring forces that change the liquid level of liquid 116 as the reservoir empties through conduit 118 or is refilled, thus changing varied flow rates versus time.

[00119] An example operational embodiment is outlined below with reference to FIG. 1. Reservoir 114, which as shown in FIG. 1 is open and not sealed, has a shape such that each inch of height holds lOlbs of liquid 116. Extension spring 112 has a rating of lOlbs/inch. Thus, once liquid 116 is placed in the reservoir, the height of liquid 116 relative to reservoir 114 will change, but the height of liquid 116 relative to fixed point 110 and fixed height 119 will remain unchanged regardless of the amount of liquid in reservoir 114, even though the height of reservoir 114 will change. Therefore, the hydrostatic or head pressure at fixed point 119 will remain constant, so that the flow rate of liquid through flexible conduit 118 and optional restrictor 120 will also remain constant. Liquid 116 can be refilled at any time without changing the flow rate. In certain embodiments, rather than a reservoir being suspended by extension springs, it can be set upon compression springs, with calculations similar to those above to achieve the same goals as described herein. Thus, this embodiment illustrates an example fluid delivery system which requires no electricity, no power, no external feedback controls, no pumps, and no intervention for delivery of fluid 116 at essentially constant flow rate.

[00120] FIG. 2 shows a perspective view of another embodiment. Siphon tube 210 is filled with liquid and immersed at one end in reservoir 212, and terminating at a fixed point 213.

Reservoir 212 is attached at one point of attachment 214 to one end of lever 216 balancing on fulcrum 218. On the other side of the lever 216 is a second point of attachment 220 for coupling lever to compression spring 222 which is attached also to a fixed point 224. Points of attachment

214 and 216 can be any distance along lever 216 so as to gain a mechanical advantage for either the spring force or weight of reservoir 212. FIG. 2 thus illustrates that a lever and fulcrum can interface with a spring system and reservoir to provide mechanical advantage, disadvantage, or neither (e.g., simply transmitting force). Such embodiments can be useful with a spring or spring system that does not have the correct rating, extension length, weight rating, and so forth. Other embodiments that can interface with a spring system and reservoir include one or more levers, a wheels/axel, a pulley, an inclined plane, a wedge, and a screw. Other mechanisms for transmitting a force and optionally multiplying or dividing the force (for example, not meant to be limiting, a gear or gearset or transmission, compound machines, 4-bar linkages, etc.) are also contemplated.

[00121] The embodiment in FIG. 2 can operate similarly to the embodiment shown in FIG. 1, except that the force of compression spring 222 is used to counteract the weight of reservoir 212 in FIG. 2, instead of an extension spring 112 counteracting the weight of reservoir 114 as shown in FIG. 1. Thus, as reservoir 212 becomes lighter as liquid flows through siphon tube 210, compression spring 222 elongates. As compression spring 222 elongates, the force it exerts on lever 216 is decreased, which balances the weight of reservoir 212 (and tube 210, etc.). Selection of a reservoir 212 such that the weight of liquid in each unit of vertical measure is equivalent to the force exerted by compression spring 222 in each corresponding unit of vertical measure as dictated by lever 216 allows for the height of reservoir 212 to increase, but the level of fluid in the reservoir relative to fixed point 213 or 224 to be the same. For example, in one embodiment, points 214 and 220 are equidistant from fulcrum 218 on opposite ends of lever 216, so that each vertical measurement of liquid in reservoir 212 exerts essentially the same unit of force per each same unit of vertical expansion or compression of spring 222. Since the level of liquid in reservoir 212 drops, but the reservoir itself raises, the fluid height remains constant with respect to fixed points 213 and 224, and thus, the hydrostatic head pressure at fixed point 213 will remain the same as the height of the column of liquid above point 213 remains unchanged.

[00122] In an embodiment illustrated by FIG. 3, objects 410, 412, and 414 are attached to each other by rod 416. In such an embodiment, objects 410, 412, and 414 are buoyant in liquid

418 contained in reservoir 420. Rod 416 terminates at point 422 to transmit a force relative to the amount that objects 410, 412, and 414 are immersed in liquid 418 and the relative buoyancy of objects 410, 412, and 414 in liquid 418. In such an embodiment, the force on rod 416 through point 422 is in the opposite vector direction from the immersion of objects 410, 412, and 414. In another embodiment, objects 410, 412, and 414 sink in fluid 418 and so the force on rod 416 and point 422 is in the same vector direction as the immersion of objects 410, 412, and 414. In some embodiments, objects 410, 412, and 414 have different buoyancies from each other; in some embodiments, objects 410, 412, and 414 have identical buoyancies to each other. In some embodiments, the force produced on rod 416 and point 422 by immersion of objects 410, 412, and 414 into liquid 417 has a varied force versus distance immersed curve. In some embodiments, the illustrated embodiment can be interfaced through point 422 to deliver this force to other embodiments described in this disclosure. In some embodiments, additional objects can be attached to rod 416, additional rods can be used, and so forth. The use of three objects is not meant to be limiting, and any number of objects and rods could be used to produce a force at point 422.

[00123] Immersion of objects 410, 412, and 416, along with rod 416 produces a force either in the direction of immersion, opposite the direction of immersion, or no force at point 422. The magnitude of the force and the first derivative, second derivative, and subsequent derivatives of force at point 422 can be tuned by selection of size, shape, material, and relative buoyancy of objects 410, 412, and 414, as well as rod 416, in addition to the nature of fluid 418. Thus, a known force versus displacement curve can be configured or chosen. A variation of pressure, weight, or external force, for example gravity, on the system, can be accommodated and used to produce various forces as desired.

[00124] As shown in FIG. 4, an embodiment employs expandable bladders 510 attached to conveyor belt means 512 which rotates around rotation means 514 and 516. Expandable bladders 510 have an umbilical 518 which can be attached to a compressed air source 520 to inflate expandable bladders 510 below the surface of liquid 522. An air release point 524 allows expandable bladders to re-contract. The use of air is not meant to be limiting, only exemplary, other gases could be used or fluids with different densities from liquid 522. In some

embodiments, expandable bladders 510 are replaced with cup-shaped containers which open downward on the right side of conveyor 512 in FIG. 4, and open upward on the left side of conveyor 512, similar to a water wheel arrangement.

[00125] As shown in FIG. 4, inflation of expandable bladders 510 produces a buoyant force on expandable bladders 510 due to the submersion of the expandable bladders in fluid 522, which pulls conveyor 512 and thereby turn rotation means 514 and 516. If expandable bladders 510 are inflated to the same degree as they pass, in the figure, from left to right over rotation means 516, a constant torque is applied to rotation means 514 and 516. This can be interfaced as needed with external machinery to produce a known force based on the amount of buoyancy created in expandable bladders 510 by expansion with air from compressed air source 520 and the nature of fluid 522. Release of air at point 524, in some embodiments outside of the liquid, returns the expandable bladders to their non-expanded condition and allows the conveyor 512 to continue to turn. In embodiments where expandable bladders are replaced with cups opening upward on the left side of FIG. 4, and downward on the right side of FIG. 4, similar to a water- wheel arrangement, displacement of fluid in cup shaped containers as they pass, in the figure, from left to right over rotation means 516 by filling the downward facing cups with air from compressed air source 520 can produce a similar buoyant effect on the cups, with one advantage being that no umbilical 518 needs to be attached to the cups nor air releaser(s) 524 as the cups will automatically re-fill with water as they pass, in the figure, from right to left past rotation means 514.

[00126] FIG. 5 illustrates the principle of operation of a siphon, which is illustrative of aspects of one or more embodiments as described herein. Although siphons are contemplated for use in one or more embodiments, the use of bulkhead fittings or other means of creating a liquid-tight seal in a container may be more convenient for one or more embodiments.

[00127] FIG. 6 illustrates an aspect of one or more embodiments which employs one or more float valves. A lower reservoir, from which fluid is to be dispensed, is connected by a conduit to an upper reservoir. The conduit is alternatively opened or closed based on the action of a float valve. Fluid fills the lower reservoir once the float valve actuates by dropping below some configurable height, and fluid ceases to fill the lower reservoir once the float valve returns to some configurable height. A skilled artisan will be familiar with various float valves that can be used in one or more embodiments. The aspect illustrated in FIG. 6 allows for a mostly constant but known flow to be produced from the lower reservoir, since the hydrostatic pressure or fluid height changes only insofar as the float valve actuates. Such an aspect is useful for other embodiments described herein, wherein a smaller, lower reservoir can be kept replete with liquid based on a larger, upper reservoir, so that the smaller reservoir does not need to be filled as often by an operator. In other words, a large container can be refilled less often than a smaller container, yet the smaller container placed in an advantageous location or used for some other purpose.

[00128] FIGs. 7 and 8 are photographs of example implementations of some embodiments of the disclosure. The teachings disclosed herein were used to construct the example shown in FIGs. 7 and 8. For simplicity, low-cost components were used, which could have provided limitations in terms of precision and accuracy of the system, however, as shown in the corresponding data, the delivery ability of the system was essentially not affected by these limitations.

[00129] A 5-gallon bucket was filled, and was measured to have a weight of approximately 40.7 lbs.

[00130] The full bucket had a liquid level of approximately 13.5 inches. [00131] Although common 5-gallon buckets are not perfect cylinders (so that they can stack when empty), for the purposes of approximation, it was assumed to be so. Therefore, a spring that has a force constant equal to this weight over this distance is required, and the value was determined as:

40.7 lbs

= 3.014815 lbs/inch

13.5 inch

[00132] For the purposes of this example, there are some considerations that are noted. First, is that the container contributes negligibly to the total weight of the reservoir. A typical 5-gallon plastic bucket weighs about 1.8 lbs., so for an illustrative example, this approximation is acceptable. While heavier or lighter buckets can be used, a consideration in constructing systems as described herein is that the bucket, when full of a liquid of interest, does not exceed the rated weight of the spring system. Another consideration is that the spring(s) chosen are able to stretch the entire distance of the bucket fill height. In other words, the springs act as a spring over the entire length that they are required to do so, and don't, for example, reach their length limit and begin to deform irreversibly. Another consideration is that the spring(s) are able to withstand the entire weight of the filled bucket.

[00133] The calculations performed above are in imperial units, but can be in any convenient unit, and the effect is independent of the system of measure. However, having done these calculations, for example, one can go to a supplier and select springs with a 10-15" extended length.

[00134] Since it may be difficult to find a single spring that has precisely the desired spring constant, a plurality of springs, configured in parallel, i.e. all springs acting in the same axis but not linked to each other, that will have the force of a single spring additively, can be used. A skilled artisan will understand that combining springs as described, in a parallel fashion, will create a summed spring constant and weight rating equal to the number of springs times their individual spring constant and weight rating, while combining springs in series, where each spring connects to one or two others in a "string" configuration, will produce an effective spring with longer rated length but same spring constant and weight rating as the springs which form it. A table of the number of springs, along with what each of their spring constants, and the total weight each spring holds, can be generated, as below in Table 2 (see also Figures 12 and 13): Table 2

[00135] Then, a spring or springs are identified that have a spring rating about one of these values, with sufficient extended length, and with sufficient maximum load. It should be noted also that the minimum load, sometimes called the minimum deflection rating, could limit the usefulness of system of this embodiment at low reservoir container volumes. The minimum load or minimum deflection rating is the minimum amount of weight or force on the spring required to deflect it. In other words, as the fluid is dispensed and the amount of fluid in the reservoir is depleted, the weight of the reservoir might not be sufficient to stretch an extension spring so that its spring force is being delivered to the reservoir. An item having a spring constant of 0.43 (about the rating of a 7-spring system which calls for springs having a rating of 0.4307 lbs./inch) and a max rating of 6.63 (greater than the required 5.81 lbs.) was selected. Alternatively, springs could be custom manufactured for greater precision or accuracy, fewer or more springs, etc. (Note here that the minimum rating or minimum deflection for one of these springs is 0.431bs, which produces a summed rating for all 7 springs of approximately 3.Ollbs, so that so long as there is more than 1.21 lbs. of liquid - which, for water, is approximately 18 oz. - in the bucket, the springs will be extended and therefore will produce the desired effect). Alternatively, a small weight could be used to make the effective weight of the bucket is greater than or equal to 3.01 lbs.

[00136] The seven springs are attached to the top of the container such that the force is evenly distributed, and so that the force of gravity is exactly opposite the extension of the springs. One of many possible combinations is to evenly distribute the springs around the circumference of the top of the bucket. Measuring the bucket's diameter at 11.5 inches, a spring spacing below is determined: 11.5 * π

— = 5.16 inches

[00137] Alternatively, one could measure (360 degrees/7 =) 51.42° between the springs from the center point in the bucket. Using the bucket as a template, proper attachment points to the surface from which the bucket is suspended can be made so that each spring is plumb.

[00138] FIG. 7 shows the system as assembled, using a frame made out of lumber to provide a means from which to suspend the bucket. FIG. 8 shows a closeup of the outlet of the tube, which is attached to the support frame, and therefore at a fixed height relative to the suspension points. Not shown in these pictures is a bucket used to collect water as it flowed out of the system.

[00139] Data was collected from several runs of this system, using water, at various flow rates. For the purposes of the flow rates tested, a valve that was partially opened/closed was used to provide a desired drip/flow rate. The data was collected using an ultrasonic sensor that measured distance from the top of the water level to the top of the bucket used to collect the water where the sensor was positioned. Alternatively, the distance from the top of the bucket with springs attached, from which water flowed, to the level of liquid in the bucket could have been measured, and would have provided an inverse slope to the one shown in FIGs. 9-11. This is not a perfect measurement of the amount of liquid dispensed since (a) the bucket is not a perfect cylinder, (b) the ultrasonic sensor has some error associated with it, and (c) the water can be rippled, providing different heights during the brief measurement time of the sensor.

However, FIGs. 9-11 show a very good r² fit to a straight line, indicating a constant delivery rate of fluid.

[00140] FIG. 9 shows the results from an example period of operation of the apparatus shown in FIGs. 7 and 8. The frequency of data collection was every 60000 milliseconds, and a total of 6000 reads were collected. As can be seen from FIG. 9, the distance from the top of the collection bucket to the top of the water collected decreased at about a linear rate, showing the flow rate was about constant. FIG. 10 shows another operation period, whereby the degree the valve was opened was changed to produce a different flow rate. Nonetheless, a constant flow (again, as evidenced by a linear decrease of the distance between the top of the water level to the top of the bucket) was observed. FIG. 11 displays a moving average of the data from FIG. 10, which produces less "spikes" due to sensor noise or bad readings.

[00141] As can be seen in the data, there is a slight "curve" associated with the height of the liquid in the receiving bucket versus time. This is because both that receiving bucket and the dispensing buckets are not perfect cylinders. Thus, the weight-per-vertical inch of liquid in the dispensing bucket is not precisely linear; and the amount of liquid per vertical inch in the receiving bucket is not precisely linear.

[00142] FIGs. 12 and 13show the calculations as described above, for the system shown in FIGs. 7 and 8, and the data from which was shown in FIGs. 9-11.

[00143] Although for the illustrative example shown and illustrated in FIGs. 7-13 a valve was used to restrict the flow, valves can be become clogged when used at low flow rates, e.g. less than 5 gal/day, when the liquid used contains salts or suspended solids, or when other environmental concerns can create issues with valves. To solve these problems, two methods of restriction are discussed below. The first describes how to perform calculations on tube diameter and length to produce a desired flow given a certain head pressure (using formulae to calculate pressure drop across a narrow tube). The second describes how to use the Kozeny-Carman equation, which describes fluid flow through a packed bed.

[00144] Calculations for restricting flow using a narrow tube so that a known volume can be delivered at a known flow rate are discussed below. The following shows how to accomplish these calculations. As an example, the calculations below are performed on a dosing system where the goal is delivery of 15 oz./day, which is about 0.0185 L/hour.

[00145] According to calculations, the pressure of a 2-meter-high column of water at its base is about 0.1932 atm, or 2.8395 psi. The fluid height, and therefore head or hydrostatic pressure delivered by a system configured as described herein will remain constant, as shown by other calculations. Since the head pressure is known, and the outlet pressure is also known

(atmospheric pressure), the pressure drop is known, and constant.

[00146] In some embodiments, a tube, hose, pipe, sluice, and/or conduit with a low ratio of diameter to length can serve as an appropriate restrictor for dispensing fluids. As an example, to the reservoir shown in FIG. 1 is attached a relatively wide-bore tube as the flexible conduit 118, as pictured in FIGs. 7 and 8, which is subsequently attached at the fixed height 119 to a long, narrow-bore tube. Since the pressure drop across the length of the wide-bore tube is negligible, and since the height of the liquid in reservoir 114 relative to fixed height 119 is constant, the wide-bore tube does not substantially affect the hydrostatic pressure of the liquid as measured at fixed height 119. In contrast, the pressure drop of the narrow-bore tube is much higher per unit length, which serves to restrict the flow of the liquid. Thus, a wide-bore tube is referred to as a

"feed" tube or conduit, whereas the narrow-bore tube is referred to as a "restrictor" (shown as restrictor 119 in FIG. 1) or "regulator" tube. Using such a system, where fluid is being dispensed from a known height, one can either calculate the required tube length, knowing the pressure drop and tube dimensions, or "calibrate" a given restrictor tube to arrive at a desired flow rate, as disclosed below. Since it has been established that the fluid height is unvaried in the system described by FIG. 1, the hydrostatic pressure at the entrance to the restrictor tube is unchanged.

[00147] Pressure drop of a liquid flowing through a tube is described by the Darcy-Weisbach Equation:

[00148] £ =

[00149] Where Ap is the pressure drop, L is the length of the column,//? is the "Darcy Friction Factor," p is the fluid density, v is the mean flow velocity (measured as volumetric flow rate), and D is the hydraulic diameter of the pipe.

[00150] Most of the variables in this equation are readily obtained by empirically, through measurement of system characteristics. For example, measuring the pressure drop can be a matter of measuring the fluid height from which the fluid is dispensed. Similarly, the hydraulic diameter of a pipe with circular cross-section can be the inner diameter of the pipe, which can be measured or may be known from the manufacturer of the pipe. The density of the fluid can be determined/obtained (versus temperature, if appropriate) by various methods. However, the "Darcy Friction Factor" f_D variable encompasses many aspects of the system including the pipe roughness and the viscosity of the fluid, some of which vary not only with external/systemic variables such as temperature, but with the flow rate of the system itself, which is the desired output of the equation. Thus, it is practical to perform measurements directly on the system of interest or tubes of interest, as a way to calibrate the expected delivery volume given a certain hydrostatic pressure. While some solutions exist for calculation of the Darcy Friction Factor, it can be onerous to derive or measure these values, especially for a wide variety of fluids and pipe systems. Since flow rate is the relevant value, the method disclosed below empirically provides the flow rate of a given system vs. pipe length, and compares these values to calculated values as a check.

[00151] Table 3 summarizes the results of seven experiments in which a silicone tube of 1/32 inch internal diameter was used as the output of a system diagrammed in FIG. 1 and similar to the one illustrated in FIGs. 6-10. A constant head height of 34 inches was used to generate this data: Table 3.

[00152] The measurement of low flow rates (<5 gal/day) by volumetric observation of gallon markings was inherently inaccurate as can be witnessed by the standard deviations of flow rates. However, counting the drops that came out of the pipe in a given time interval demonstrated that in most cases, the flow rate was relatively constant (data not shown). The data collected illustrates an example empirical flow method of the disclosure, and it is to be understood that other methods can be used to more accurately measure flow rates, such as weighing the output of the tubes, electronically measuring the height of fluid in collection vessels (as discussed above), using flow meters, or using more accurate volumetric measurements.

[00153] The data in Table 2 is summarized in FIGs 14-16. In FIG. 14, the relationship between the calculated flow rate and measured flow rate is found to be mostly linear, with a coefficient of variation (r²) equal to 0.9847 (in a perfectly linear relationship, r² = 1). Although the measured flow rate was much lower than the calculated flow rate, that the two were related linearly demonstrates the predictability of the system; using inaccurate but constant inputs, a calculated flow rate can be reasonably used to predict an actual system flow rate. In fact, a much closer relationship can be found by choosing Darcy Friction Factor inputs such as viscosity, K losses, etc., that more closely matches the fluid being dispensed and tube construction, but so long as the same friction factor inputs are used, the relationship holds.

[00154] FIGs. 15 and 16 show the calculated and measured flow rates, respectively, vs.

column length. Although the measured flow rate was much lower than the calculated flow rate, the similarity in the shape of the two curves again demonstrates the predictability of the system.

The similarity in the shape of the two curves provides further evidence for the linear relationship between calculated and observed flow rates as shown in FIG. 14. [00155] As another means to restrict flow, a packed bed can be used, through which flow is diverted, to restrict the flow. The Kozeny-Carman equation dictates laminar fluid movement through packed beds. This equation can be used for some embodiments, and was utilized in the formulas/calculations shown in FIGs. 17 and 18. Generally, unless very small packing material or very viscous liquid is used, extremely long columns may be needed, simply because the desired flow rate of the column is so low.

[00156] If a standard-sized packing material (say, 2mm glass beads such that the risk of plugging the column is minimized) the column must be very long (e.g. kilometers), even with only a 1 meter head height (lm of water pressure). If narrow beads are used, a reasonably sized column can be obtained, but may be susceptible to clogging. Such considerations can provide motivation for using a narrow bore tube as described above.

[00157] Slow flow rates, for example where liquid drips rather than contiguously flows from an exit port can cause salts and other materials in the liquid to build up on the exit port.

Therefore, it is possible to immerse the bottom of the column-restrictor into the water or liquid into which the dispensed liquid is added, to reduce or eliminate salt buildup from droplets drying out during formation.

[00158] FIG. 19 shows a bracket embodiment that can be used with one or more embodiments described herein. This bracket serves as a fixed point from which to mount a reservoir and spring system as shown in other examples and figures. On central frame 2002 are mounted four extension arms 2004. At the outside, relative to central frame 2002, on each of the extension arms are a rest pad, 2006, which can rest upon the inner lip of a manhole. Rest pads 2006 are shown in this embodiment with a 1/8" thickness so as to minimally add height to a manhole lid placed back onto a manhole after a bracket is installed. Extension arms 2004 each contain an adjustment groove 2008 through which two retaining bolts 2010 pass. Retaining bolts 2010 are fixed by retaining nuts 2012. Extension arms 2004 can move along the axis of the adjustment groove by sufficiently loosening retaining nuts 2012 and retaining bolts 2010. On the other hand, extension arms can be fixed by tightening retaining nuts 2012 and retaining bolts 2010. In this way, rest pads 2006 can be made to rest on manholes of arbitrary size, and locked in place securely. The bracket can be fit to manholes of arbitrary sizes, only limited by the size of the central frame 2002. This example shows one aspect of one or more embodiments that allow for a convenient manner to mount one or more embodiments described herein, or other devices, in a sewer system, by simply opening a manhole, placing an embodiment or other devices within and attaching to a bracket similar to the one shown here, mounted on the lip of the manhole, then replacing the manhole lid.

[00159] As used herein, the term "manhole" refers to a covered opening, such as those commonly found as an entrance to a tank, vessel or other enclosed system. For example, manholes are commonly found in roadways, streets, floors, and paved surfaces. Often, but not exclusively, such manholes provide access to an underground structure, such as an underground tank, sewer line, or other drainage system. Manholes are also commonly found on railroad oil tanks, mixing and reaction vessels, barges, and reactors, such as anaerobic digesters, in order to provide access to the interior of such structures. In some instances, manholes are sized to permit a person to descend down a vertical opening.

[00160] FIG. 20 shows an embodiment comprising a ram pump. A reservoir 2102 contains a fluid 2104 with a fluid level 2106 as shown. The reservoir is suspended via spring 2108 to fixed point 2110. The spring constant can be selected by the user to provide a constant height of fluid 2104 with respect to fixed point 2110. The fluid is allowed to flow through a conduit 2112 which is coupled to reservoir 2102 by means of attachment 2114. The liquid that flows through conduit 2112 is routed to a ram pump, 2116. Ram pump 2116 has delivery conduit 2118 through which fluid intermittently flows, as well as waste output 2120. Ram pump 2116 operates as known ram pumps in the art, or other similar devices that convert motion of a fluid into pressure, and generates a delivery output flow level 2122 which is higher than the initial fluid level 2106 as shown. Thus, FIG. 20 shows an embodiment which comprises a ram pump.

[00161] FIG. 21 shows an embodiment comprising a flow regulator. Reservoir 2202 contains a fluid 2204. Into said reservoir 2202 flows additional fluid 2204 through intermittent input flow conduit 2206. Reservoir 2202 is suspended by spring 2208 to fixed point 2210. Spring 2208 can be configured to provide a fluid level, 2212, that is constant or changing with time. An optional overflow exit conduit 2214 prevents the reservoir from overflowing and fixes the maximum fluid height. An output conduit connection 2218 connects reservoir 2202 to output conduit 2216, which terminates at a height fixed relative to fixed point 2210, and a proper configuration of spring 2208 can provide an output flow 2220 that is constant, regardless of the intermittent input flow 2206, by the mechanics described hereinabove, or changing with time as a function of spring 2208, flow through intermittent input flow conduit 2206, and fluid level 2212. Output conduit 2216 can be appropriately restricted to provide a limitation to total flow, as described hereinabove, so that as long as the integral of intermittent input flow exceeds the integral of output flow, over the same time period, FIG. 21 illustrates an embodiment which comprises a flow regulator, which takes an intermittent flow, e.g. from a ram pump, and converts it into a continuous flow.

[00162] FIG. 22 shows a photograph of an embodiment as installed in a municipal sewer lift station. Reservoir 2402 is comprised of a plastic tank 2404 held within steel frame 2406. This provides structural rigidity as well as points of attachments for springs 2408 to bracket 2410. A total of eight springs 2408 are used in this embodiment, although two are indicated. Bracket 2410 is mounted across the opening of the lift station and is therefore immobile, or fixed, whereas reservoir 2402 can move vertically as springs 2408 extend or retract. As can be seen in the photograph of FIG. 23, liquid 2412 is being poured through funnel 2414 which is operatively coupled to reservoir 2402 by attachment to plastic tank 2404. Funnel 2414 has an optional funnel cover 2416 which can be closed when liquid does not need to be added, to prevent evaporation or external debris from entering plastic tank 2404. Conduit 2418 is connected to plastic tank 2404 by valve 2420 so that flow can be turned on an off as needed. As can be seen in the picture, springs 2408 are stretched with the weight of the fluid, and will continue to stretch as additional fluid is added. Not shown in the picture is the terminus of conduit 2418, which is at a fixed height in the lift station, which is therefore also of fixed distance relative to bracket 2410.

Conduit 2418 has sufficient slack between the end connected to valve 2420 and the terminus at a fixed height in the lift station, to accommodate the vertical movement of reservoir 2402 between being completely full and being completely empty. As described in other examples and figures, the embodiment shown in FIG. 22is configured to deliver a constant amount of liquid 2412 regardless of how full reservoir 2402 is. This figure and example show a useful embodiment which is capable of precisely and accurately delivering a fluid into a desired location, which is currently being used to great advantage by a municipality for their sewage treatment, as described hereinbelow.

[00163] FIG. 23 shows views of the wet well or bottom of the lift station from FIG. 22. On the left is the wet well or bottom of the lift station prior to being cleaned out. Seen in the photograph on the left is a significant buildup of fats, oils, and grease, yellow-beige material on the top of the fluid that occupies the wet well. This is a common problem in lift stations and other sewer infrastructure. Fats oils and grease are poorly soluble in and less dense than water, so will float and accumulate on the surface of sewage water, especially where flows are slowed, water is still, agitation is minimal, etc. The fats, oils, and grease were removed from the wet well, and the apparatus described and shown in FIG. 23 was installed to dispense about 1 gallon of treatment product per week into the well. The treatment product prevents buildup of fats, oils, and grease, so long as it is continuously applied into a sewer. As seen in the photograph on the right of FIG. 23, after 6 weeks, little-to-no fats, oils, and grease buildup had accumulated on the surface of the liquid in the wet well. It is relevant to note that in this wet well, in addition to many other similar situations, the wet well comprises a confined space or explosive environment, and/or a remote location without power. Delivery of the treatment fluid would normally require an explosion proof pump, i.e. rated for use in hazardous atmospheres/environments, such as outlined in the National Electrical Manufacturers Association's Class II Div I guidelines; pumps which meet these guidelines are expensive and require extensive maintenance. In this lift station in FIGs. 22 and 23, no electrical power was available, so the pump that would otherwise be used for the treatment fluid application would require a battery, and therefore recharging or replacement at regular intervals, further complicating the operation and maintenance of the explosion proof pump. Since the wet well is a confined space, entry for this kind of maintenance requires permitting, proper training and safety protocols, and additional insurance and liability concerns. In contrast, once the embodiment shown in FIG. 22 is installed, it can be refilled without entering the wet well as shown in FIG. 22, and does not pose an explosion threat. This example and FIGs. 1, 2, 7, 8, 19 and 22 demonstrate that one or more embodiments is useful to provide a robust, simple, inexpensive, accurate, and precise means to deliver a fluid at a constant rate without the need for electricity, battery, or explosion-rated equipment.

[00164] FIG. 24 shows an illustration of an embodiment which allows for a smaller reservoir to act as the flow control reservoir, being periodically refilled by, for example, a larger reservoir, so that the smaller reservoir, which is depicted as being inside a manhole under a street

(cutaway), does not need to be accessed as regularly. Drum 2602 contains a fluid to be dispensed into sewer 2604. As illustrated, drum 2602 is somewhat remote from sewer 2604, so that drum 2602 can be easily accessed for refilling or replacement. From drum 2602, the fluid is allowed to flow through refill conduit 2606, which is shown to be on the ground surface, but could be underground or routed in any convenient manner. Thus, drum 2602 is in fluid communication with reservoir 2610. Refill conduit 2606 passes through manhole 2608 and terminates inside reservoir 2610, as shown in the enlargement and cutaway in FIG. 24. At the terminus of refill conduit 2606 is a float valve 2612, which can be configured to refill reservoir 2610 at pre-set levels. Reservoir 2610 is suspended via springs 2614 to bracket 2616, which are both similar to those described in other figures and descriptions herein. Springs 2614 are configured to change the height of reservoir 2610 to maintain a constant fluid height in this example figure, but a variety of configurations are contemplated. From reservoir 2610 leads exit conduit 2618, which terminates in restrictor 2620. Restrictor 2620 is affixed by bracket 2622 to a fixed height within the sewer 2604, and configured to allow a known rate of fluid passage based on the height of fluid within reservoir 2610. Thus, the example of FIG. 24, which shows a combination of one or more embodiments and/or disclosures described herein, provides a convenient means for delivering a fluid, for example a treatment chemical, into a sewer system, while decreasing the frequency and facilitating the task of refilling the system.

[00165] FIG. 25 shows an embodiment which employs gears to produce a mechanical advantage, allowing a single spring with a rating not equal to the weight per unit height of the reservoir containing fluid to be employed. FIG. 25 is an illustration of one of several ways contemplated to configure one or more embodiments to transmit a force between a reservoir containing a fluid and the force mechanism, as hereinabove described, itself. For example, in FIG. 25, reservoir 2702 is attached to geared cable 2704. Geared cable 2704 actuates gear 2706, which as depicted, actuates pinion 2708 in a way such that a multiple of the distance and therefore division of the force is created by the interaction of gear 2706 with pinon 2708. In some embodiments, the relative size of gear 2706 and pinon 2708 is reversed. In some embodiments, the relative size of gear 2706 and pinion 2708 are equivalent. In some

embodiments, a series of gears, for example comprising a gearbox or transmission, can be used in place of gear 2706 and pinion 2708 shown in FIG. 25. Pinion 2708 actuates rack 2710 which impinges on compression spring 2712 which is fixed to fixed attachment 2714. As configured in FIG. 25, compression spring 2712 can have a lower force per unit distance value in order to create a constant liquid height, as described herein, than a single extension spring attached to reservoir 2702, as depicted, for example in FIG. 1, but a variety of spring forces are

contemplated to produce a variety of fluid hydrostatic pressures as required. As in other examples and figures, fluid can flow through conduit 2716 through restrictor 2718, which is affixed at some height fixed relative to fixed attachment 2714 or any other convenient point in the external reference frame, so that reservoir 2702 can move relative to restrictor 2718, which can be configured for a known delivery volumetric flow rate. Shown in this example and others is reservoir 2702 as a rectangular prism, but a variety of shapes are contemplated as shown in other figures and described herein; as shown in FIG. 25, conduit 2716 comprises a tube or hose which has slack, but other means of allowing displacement between reservoir 2702 and the terminus of conduit 2716 and restrictor 2718 are contemplated, such as an accordion-type hose, a flexible (along the hoses' axis) tube, a coiled tube, etc. Thus, FIG. 25 shows an example of one way a fluid delivery system described herein can make use of one or more force multiplication and/or division and/or transmission systems, to allow for the convenient selection of components for the force system, for example, a spring as shown in FIG. 25. [00166] FIG. 26 depicts an embodiment which uses a pulley to provide mechanical advantage. Reservoir 2802 is connected to block and tackle 2804 via rope 2806 and pulley 2807. Although shown in FIG. 26 with a fixed block, wherein rope 2806 is fixed to one of the pulleys comprising block and tackle 2804, other similar embodiments are envisioned wherein rope 2806 is attached directly to spring 2808. As shown in FIG. 26, spring 2808 is attached to block and tackle 2804 and thus a change in the force required per unit movement of reservoir 2802 is realized. As described hereinabove, a mechanical advantage, disadvantage, or no change in force can be realized by a force transmittal system, for example, in FIG. 26 the force required by spring 2808 will be lower over a longer distance. In FIG. 26, the terminus of conduit 2810 is attached at a fixed point 2812 which is also a part of fixed block 2814 to which spring 2808, block and tackle 2804, as well as pulley 2807 are attached, but other attachment points are envisioned. A flow restrictor 2816 is used in FIG. 26 comprising a long, narrow tube, but other restrictors are possible. Thus, FIG. 26 shows an embodiment wherein the force system is attached to a reservoir by a force transmittal system, to gain a mechanical advantage, which allows for an arbitrary selection of appropriate springs as described hereinabove.

[00167] FIG. 27 shows an example embodiment which utilizes the buoyancy of one or more objects as a force system to controllably change the height, and therefore hydrodynamic pressure of a reservoir. Reservoir 2902 is connected to lever 2904 balancing on fulcrum 2906. The distal end of lever 2904 is actuated upon by a second lever 2908 balancing on a second fulcrum 2910. Fulcrums 2906 and 2910 can be connected or not. The distal end of lever 2908 is impinged upon by rod 2912 which is connected to float 2914, 2916, and 2918. As the floats are submersed in fluid 2919, the force exerted vertically on rod 2912 increases until each floats is fully submerged, then remains constant until the next floats begins to be submerged. For the purposes of this example, floats 2914, 2916, and 2918 are shown to be of different sizes and materials but similar shapes, but could optionally share be of the same or different sizes, materials, and/or shapes, and be a single object or a plurality of objects; the floats can also be connected to a plurality of rods. When reservoir 2902 is full, it creates a downward force, transmitted by levers 2904 and 2908, to rod 2912. By selecting the size, shape, and materials of floats 2914, 2916, and 2918, the force on reservoir 2902 can be changed in a constant or variable way, thereby changing the height of reservoir 2902 based on the amount of liquid contained in, and therefore weight of reservoir 2902. To reservoir 2902 is attached accordion- style conduit 2920 through which the fluid contained in reservoir 2902 can flow. As depicted in FIG. 27, conduit 2920 is an accordion-like tube, which can extend or retract along its axis, although other flexible conduits, or a tube with slack, could be used. At the distal end of accordion-style conduit 2920 is drip irrigator 2922, which acts as a restrictor, to limit flow out of reservoir 2902 based on the hydrostatic pressure of the fluid therein contained, similar to other embodiments, although other means to restrict a fluid flow are contemplated as disclosed elsewhere herein. Although levers of approximate scale size of the reservoir and floats are depicted in FIG. 27, it is shown as an example, and various levers, of varying size, including one or more than two, can be combined to provide the effects as described. Mechanical advantage or disadvantage can be gained or not. In some embodiments, floats 2914, 2916, and 2918 are not buoyant in fluid 2919, and therefore the force on rod 2912 is in the downward direction. Thus, FIG. 27 shows an embodiment comprised of several of the disclosures described herein that can be configured to use buoyant force as the force system to variably change the height of a reservoir, and therefore the hydrostatic pressure thereof and therefore flow rate therefrom.

[00168] FIG. 28 shows a top-down exaggerated perspective of an embodiment comprising a bracket, similar to that photographed in FIG. 19, fitted to a manhole, from which a reservoir is suspended. Manhole 3002 with manhole lip 3003 is shown in FIG. 28, uncovered with the manhole lid that may normally cover it. Arms 3004 are extended from central frame 3006. Nuts 3008 and bolts 3010 are used to hold arms 3004 in the correct position. Pads 3012 are placed on manhole lip 3003 of manhole 3002 and are made of a minimal thickness so that when the manhole cover is replaced, the cover does not substantially sit above flush height with the manhole ring and surface. From central frame 3006 are attached springs 3014 by brackets 3016. The distal ends of the spring attach to reservoir 3018. Not shown is a conduit leading from reservoir 3018, as shown in other embodiments, as well as an optional restrictor. The distal end of the restrictor, which can be at a fixed height, can be suspended conveniently from the bracket, e.g. from frame 3006 or arms 3004, using a string, cable, wire, cord, boom, bracket, rod, rigid or flexible member, etc. In some embodiments, a string or cable can be attached to central frame 3006 by which the terminus of the conduit and restrictor can be set to a predetermined level as well as retrieved for priming the system, changing the restrictor, maintenance, etc. The embodiment as shown can operate similarly to others disclosed herein, whereby the bracket serves as a fixed point from which the reservoir, and optionally the restrictor, is suspended.

[00169] The embodiments disclosed herein can have a plurality outputs, and the above data, testing, and calibrations can be generated over a relatively short period of time by having multiple outputs from a single reservoir. Since the head height can be fixed (and may not be dependent on the flow rate or number of outputs), numerous conduits can be put on a single reservoir for simultaneous measurement of flow rate through tubes, columns, or pipes of various lengths. Using approximations for the tubes used, and the liquid to be dispensed, a wide range of tube lengths can be fixed to the output of the flow, the flow rates through each determined, and the data regressed as shown to determine the actual pipe length required for a desired flow rate. It will be clear to the skilled artisan that several different flow rates can be achieved from several different tubes, all fed from the same reservoir. In some cases, the tubes actually used during this testing and calibration procedure can be implemented in different embodiments once calibrated. For more accurate data, the fluid output from several pipes during calibration can be weighed as opposed to determined volumetrically, or measured in any convenient way, for example with a flow meter affixed to each pipe, or by counting droplets versus time.

[00170] One consideration for using certain systems, as mentioned elsewhere in the disclosure, is that the restrictor tube can be fixed at constant height from beginning to end of the tube. If one end of the restrictor tube is elevated relative to the other, a pressure differential can be generated which can cause discrepancies in flow rates. This is because the tube itself can generate different pressures along its length, which may make the Darcy-Weisbach equation not applicable in these situations. In some embodiments, calibration using a horizontally oriented restrictor can be used to address this issue. In addition, prior to the tube being filled, even if both ends of the restrictor tube are of the same height, variation of height between the beginning and end of the tube can lead to back pressure in some instances, which results in a changed flow rate relative to that desired. In some embodiments, these narrow restrictor tubes are coiled

horizontally and affixed to a much larger bore tube leading from the reservoir; this larger bore lead tube sets the head height, and the coiled narrow-bore tube is the flow regulator or restrictor. In some embodiments, the feed tube can be the flow restrictor tube. In some embodiments, both tubes can be calibrated using a chosen geometry to account for any pressure differences, so that the calibration process accounts for back pressures or flow restriction due to the geometry.

[00171] One advantage of the methods disclosed herein is that several variables relating to the friction loss coefficient are simultaneously measured. An additional advantage is that the variables relating to friction loss, e.g. viscosity and surface roughness, can be isolated from each other using an appropriately configured system and measured independently, or concurrently.

Another advantage is that any difference in pipe construction resulting from manufacturing processes, age, temperature, or other variables, where such difference in construction would change the friction coefficient versus a known value for that pipe and material, is accounted for.

Another advantage is that a single tube can be the source for all of the smaller tube lengths

(restrictor tube) from which the data is derived by simply cutting the needed lengths from the source tube. Yet another advantage is that the liquid dispensed during system calibration can be identical to the desired liquid for the application at hand. An additional advantage is that a single system can be calibrated against a range of temperatures, fluid characteristics, or other variables, so that the system in question can be used with any convenient fluid or in any environment. Yet another advantage is that a series of different tube lengths can be calibrated as described herein, along with varying inputs such as temperature, fluid viscosity, and so forth, to generate a system for a given fluid at a given flow rate. Another advantage is that calibration can be performed with a limited set of inputs and multivariable regression performed to characterize various system configurations, tube lengths, external/systemic variables such as temperature, fluid

characteristics, and so forth.

[00172] Thus, the reader will see that one or more embodiments enable automated ways to dispense a liquid from a reservoir without operator intervention. Other embodiments describe a system to produce a force, which can optionally be combined with other embodiments to produce dispensing systems, or used on their own or in combination with mechanisms not related to fluid dispensing. Still other embodiments disclose how to use chemicals and/or other means to better control fluid flow. Some other embodiments teach methods and systems to create a programmable fluid dispenser which has no moving parts in the flow path, can produce a flow rate that varies arbitrarily with time, requires no operator interference, no electricity, no power, and does not use control loops. Such systems can be widely useful in a variety of applications.

[00173] While the above description contains many specific details and examples, these should not be construed as limitations on the scope, but rather as exemplifications of some of the numerous embodiments of the disclosure. Many other variations are possible. For example, rather than a single extension spring used to counter the weight of the reservoir in the first embodiment, a series of springs can be used to produce a similar effect.

[00174] While various inventive embodiments have been described and illustrated herein, those of skill in the art will readily envision a variety of other mechanism, methods, and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the disclosed embodiments and equivalents thereto; inventive embodiments may be practiced otherwise than as specifically described and set forth. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[00175] Also, various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[00176] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. The use of flow diagrams is not meant to be limiting with respect to the order of operations performed. The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being "operably connected," or "operably coupled," to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable," to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

[00177] The indefinite articles "a" and "an," as used herein, unless clearly indicated to the contrary, should be understood to mean "at least one." [00178] The phrase "and/or," as used herein, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and/or B", when used in conjunction with open-ended language such as "comprising" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[00179] As used herein, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of or "exactly one of," or, when used in claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in claims, shall have its ordinary meaning as used in the field of patent law.

[00180] As used herein, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified.

Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or

B," or, equivalently "at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. [00181] All transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of and "consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. An apparatus for delivering a liquid, the apparatus comprising:

a reservoir for holding a liquid;

a flexible conduit providing an outlet from the reservoir, the flexible conduit having an exit at a fixed exit point; and

a means for variably adjusting height of the reservoir relative to the fixed exit point, the height of the reservoir being adjusted relative to a quantity of liquid in the reservoir such that hydrostatic pressure of the liquid in the reservoir is constant relative to the fixed exit point of the flexible conduit.

2. The apparatus of Claim 1, wherein the apparatus is configured so that the liquid in the reservoir has a height that is constant relative to the fixed point.

3. The apparatus of Claim 1, wherein the reservoir is suspended.

4. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir is selected from the group consisting of: one or more springs; one or more elastic members; one or more elastically deformable materials; one or more rubber bands; one or more bungee cords; one or more materials that provide a predictable force as a function of displacement; and one or more materials that obey Hooke's law.

5. The apparatus of Claim 4, wherein the reservoir is suspended from one or more springs.

6. The apparatus of Claim 5, wherein the one or more springs are suspended, directly or indirectly, from a manhole.

7. The apparatus of Claim 6, further comprising a mounting bracket configured for

attachment to a manhole, whereby the apparatus is suspended indirectly from the manhole via the mounting bracket.

8. The apparatus of Claim 7, wherein the mounting bracket comprises a central frame and one or more members slidably attached to the central frame, wherein the one or more members are configured to sit on a lip of a manhole.

9. The apparatus of Claim 1, wherein the means for variably adjusting the height of the suspended reservoir comprises a fulcrum and lever.

10. The apparatus of Claim 9, wherein the means for variably adjusting the height of the suspended reservoir comprises at least two fulcrums and at least two levers.

11. The apparatus of Claim 10, wherein one of the levers is actuated by one or more floating objects disposed in a liquid.

12. The apparatus of Claim 1, wherein the means for variably adjusting the height of the suspended reservoir comprises a gear.

13. The apparatus of Claim 12, further comprising a geared cable that interfaces with the gear.

14. The apparatus of Claim 1, wherein the means for variably adjusting the height of the suspended reservoir comprises one or more pulleys.

15. The apparatus of Claim 1, wherein the flexible conduit further comprises a means for restricting flow of liquid through the flexible conduit.

16. The apparatus of Claim 15, wherein the flexible conduit has a length and an inner surface cross-sectional area, and wherein a portion of the inner surface cross-sectional area of the flexible conduit decreases and restricts flow of liquid through the flexible conduit.

17. The apparatus of Claim 16, wherein the length and inner surface cross-sectional area of the flexible conduit are configured to create a constant pressure drop of liquid through the flexible conduit.

18. The apparatus of Claim 17, wherein the inner surface cross-sectional area of the flexible conduit is configured to permit flow of liquid at a constant rate as the volume of liquid in the reservoir changes.

19. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir exerts a force substantially equivalent in magnitude, but opposite in direction, to a gravitational force exerted by liquid in the reservoir.

20. The apparatus of Claim 5, wherein the one or more springs have a combine spring

constant such that a force exerted by the one or more springs is substantially equivalent in magnitude, but opposite in direction, to a gravitational force exerted by liquid in the reservoir.

21. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir has a constant of force per unit of displacement substantially equivalent to a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant.

22. The apparatus of Claim 5, wherein the one or more springs have a spring constant of force per unit of displacement substantially equivalent to a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant.

23. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir has a force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir.

24. The apparatus of Claim 5, wherein the one or more springs have a spring constant of force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir.

25. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir has a force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir decreases as liquid exits the reservoir.

26. The apparatus of Claim 5, wherein the one or more springs have a spring constant of force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir decreases as liquid exits the reservoir.

27. The apparatus of Claim 1, wherein the means for variably adjusting the height of the reservoir exhibits variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir.

28. The apparatus of Claim 5, wherein the one or more springs exhibit variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir.

29. The apparatus of any of Claims 1-28, wherein the reservoir is a first reservoir, the

apparatus further comprising a second reservoir in fluid communication with the first reservoir and configured to refill the first reservoir.

30. A method for delivering a liquid, the method comprising:

i) providing an apparatus for delivering the liquid, the apparatus comprising: a) a reservoir for holding the liquid;

b) a flexible conduit providing an outlet from the reservoir, the flexible conduit having an exit at a fixed exit point; and

c) a means for variably adjusting height of the reservoir relative to the fixed exit point, the height of the reservoir being adjusted relative to a quantity of liquid in the reservoir such that hydrostatic pressure of the liquid in the reservoir is constant relative to the fixed exit point of the flexible conduit; and

ii) providing liquid to apparatus, such that liquid flows from the reservoir, through the flexible conduit, and exits the flexible conduit at the fixed exit point.

31. The method of Claim 30, wherein the reservoir is suspended.

32. The method of Claim 30, wherein the apparatus is configured so that the liquid in the reservoir has a height that is constant relative to the fixed point.

33. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir is selected from the group consisting of: one or more springs; one or more elastic members; one or more elastically deformable materials; one or more rubber bands; one or more bungee cords; one or more materials that provide a predictable force as a function of displacement; and one or more materials that obey Hooke's law.

34. The method of Claim 33, wherein the reservoir is suspended from one or more springs.

35. The method of Claim 34, further comprising suspending, directly or indirectly, the one or more springs from a manhole.

36. The method of Claim 35, further comprising a mounting bracket configured for

37. The method of Claim 36, wherein the mounting bracket comprises a central frame and one or more members slidably attached to the central frame, wherein the one or more members are configured to sit on a lip of a manhole.

38. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir comprises a fulcrum and lever.

39. The method of Claim 38, wherein the means for variably adjusting the height of the

reservoir comprises at least two fulcrums and at least two levers.

40. The method of Claim 39, wherein one of the levers is actuated by one or more floating objects disposed in a liquid.

41. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir comprises a gear.

42. The method of Claim 41, further comprising a geared cable that interfaces with the gear.

43. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir comprises a pulley.

44. The method of Claim 30, wherein the flexible conduit further comprises a means for restricting flow of liquid through the flexible conduit.

45. The method of Claim 44, wherein the flexible conduit has a length and an inner surface cross-sectional area, and wherein a portion of the inner surface cross-sectional area of the flexible conduit decreases and restricts flow of liquid through the flexible conduit.

46. The method of Claim 45, wherein the length and inner surface cross-sectional area of the flexible conduit are configured to create a constant pressure drop of liquid through the flexible conduit.

47. The method of Claim 46, wherein the inner surface cross-sectional area of the flexible conduit is configured to permit flow of liquid at a constant rate as the volume of liquid in the reservoir changes.

48. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir exerts a force substantially equivalent in magnitude, but opposite in direction, to a gravitational force exerted by liquid in the reservoir.

49. The method of Claim 34, wherein the one or more springs have a combine spring

50. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir has a force per unit of displacement substantially equivalent a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant.

51. The method of Claim 34, wherein the one or more springs have a spring constant of force per unit of displacement substantially equivalent to a change in weight of the reservoir per unit height of liquid in the reservoir to create a constant hydrostatic pressure at the fixed exit point so that a flow rate of liquid from the reservoir is constant.

52. The method of Claim 30, wherein the means for variably adjusting the height of the reservoir has a force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir.

53. The method of Claim 34, wherein the one or more springs have a spring constant of force per unit of displacement greater than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir increases as liquid exits the reservoir.

54. The method of Claim 30, wherein the means for variably adjusting the height of the reservoir has a force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is decreases as liquid exits the reservoir.

55. The method of Claim 34, wherein the one or more springs have a spring constant of force per unit of displacement less than a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir decreases as liquid exits the reservoir.

56. The method of Claim 30, wherein the means for variably adjusting the height of the

reservoir exhibits variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir.

57. The method of Claim 34, wherein the one or more springs exhibit variable force per unit of displacement relative to a change in weight of the reservoir per unit height of liquid in the reservoir so that a flow rate of liquid from the reservoir is variable as liquid exits the reservoir.

58. The method of Claim 30-57, wherein the reservoir is a first reservoir, the apparatus further comprising a second reservoir in fluid communication with the first reservoir and configured to refill the first reservoir.