WO2020070738A1

WO2020070738A1 - An apparatus and method for tunable regulation of fluid or gas flow

Info

Publication number: WO2020070738A1
Application number: PCT/IL2019/051051
Authority: WO
Inventors: Eli Dvash
Original assignee: Eli Dvash
Priority date: 2018-10-02
Filing date: 2019-09-24
Publication date: 2020-04-09
Also published as: IL262070A

Abstract

Apparatus implementable in an hydraulic valve for tunable regulation of fluid or gas flow, which comprises a fluid conduit that is formed with a fluid or gas flow passage along it, an upstream opening to it one side, a downstream opening from it on the other side, and a flexible portion that makes up at least part of its circumference and extends at least along an elongated part of the conduit; and a mechanism that comprised an inflatable wheel-shaped means that is adapted once it is inflated for pressing the flexible portion of the conduit to a state of reducing the size of the flow passage in the conduit, and in a way that enables increasing the size of the flow passage in the conduit by the elasticity of the flexible portion from the time the inflatable wheel-shaped means is emptied, and a method for tunable regulation of fluid or gas flow implemented in the operation of such apparatus.

Description

AN APPARATUS AND METHOD FOR TUNABLE REGULATION

OF FLUID OR GAS FLOW

FIELD OF THE INVENTION

The invention that is the subject of the Patent Application is in the field of apparatuses and methods that could be applied for regulating and sealing the flow passage in hydraulic valves.

BACKGROUND OF THE INVENTION

Preface - The background of the invention will be described below in relation to the field of hydraulic valves, but in light of the description and the accompanying figures, the skilled person will understand that the invention is not limited to applications in this field only.

Well known are hydraulic valves used for regulating and controlling the flow pressure in systems for the conveyance of fluids or gases (for example - water in agriculture, industry, civil engineering, etc.).

One example of hydraulic valves are diaphragm valves or membrane valves. This relates to apparatuses assembled at the flow line and comprise a diaphragm membrane. By stressing the diaphragm to move towards the flow or away from it, the valve apparatus allows for completely closing the flow and reopening it and/or for continuous and tunable regulation of the pressure of the fluid either downstream or upstream. A typical diaphragm valve is comprised of a cap member, a rigid valve body formed with two interfaces (sleeves) for the inflow and outflow of fluid from the valve, a diaphragm member, spring, and seat (a sort of weir) on which the diaphragm closes the valve and or regulates the flow (see for example, diaphragm valves that are sometimes called Saunders valves). In diaphragm valves, stressing the diaphragm membrane’s movement towards the flow passing through the valve and the seat beneath it, or away from it, can be achieved by means of different types of actuators. In hydraulic diaphragm valves, the pressure of the fluid upstream from the valve may be directly routed to a pressure space to be actuate there (as a control volume) on the upper surface of the diaphragm, or indirectly - by the operation of an intermediate actuator by virtue thereof.

Examples of hydraulic valves that are directly sealed by an elastomeric diaphragm mechanism are, as stated, weir-type valves of a model sometimes referred to as Saunders valves, and such valves are also known as Globe and roll seal valves (e.g. made by Nelson Irrigation). At the same time, hydraulic valves are also known that have a direct sealing feature by means of a rigid component mechanism, such as valves of the Bermad Y pattern type or Globe and Cal-Val globe pattern types.

As a rule, skilled persons engaged in the design of hydraulic valves strive to design a tunable flow passage (as required for providing precise regulation), which when the valve is fully opened will exert minimum friction on the flow of fluid passing through it (in an attempt to resemble as closely as possible the friction that the feeding pipe usually exerts on the flow passage through it on its way to the valve). In other words, skilled persons try to reduce the head losses caused by the valve structure, i.e., pressure and energy losses that increase the flow speed inside the valve. Increased flow speed due to the structure of the valve causes wear and tear, noises and accelerated wear of the valve members. In other words, skilled persons aspire to give the valve the capability of transporting a maximum volumetric flow rate (volume of fluid per time unit known also as throughput) through it, while keeping the pressure losses in its passage through the valve to a minimum. This aspiration is known in the professional jargon, when KV (flow in m /h at 1 bar differential pressure)/CV (flow in GPM at 1 PSI differential pressure) will be similar to that of the feeding pipe. The higher the KV (or CV) value, the more it indicates better performance, whereby the valve structure poses minimum interference to the flow throughput.

Hydraulic valves may be exposed to a wide range of volumetric flow rates. Thus, for example, a valve used to regulate irrigation water for agriculture may be exposed to variable line pressures over time. At the same time, the valve is required to constantly react, reduce and regulate the range of pressures to a level suitable for the pipe downstream from it (and the irrigation apparatuses positioned there), regardless of the variation in the volumetric flow rate over time. Therefore, using one valve in an effort to cope with the entire range of anticipated volumetric flow rates could make the valve susceptible to wear and tear (regulating a low volumetric flow rate for an extended time could wear down the rigid clasp (in valves wherein such clasp is implemented), and cause instability of the pressure in the supply system (thus, for example, a valve formed with a 4” diameter flow passage could have difficulty precisely regulating the flow when exposed to relatively low volumetric flow rates that are more suitable for passing through a valve with a 1” diameter flow passage). Therefore, it is sometimes necessary to use double systems (one valve for high volumetric flow rates in tandem with another valve for low volumetric flow rates), which naturally increase the cost of the system and complicates its operation (the need for command and control to enable immediately switching between valves depending on the volumetric flow rate changes in the line, which could also be momentary in duration).

The operation of hydraulic valves for reducing to the point of closing the flow passage through them is based on fluid volume accumulation (control volume), while as a rule, the greater the cross section area of the flow passage section in the valve, the greater the control volume needs to be. At the same time, the greater the control volume, the longer it takes to close or open the valve (due to the need to accumulate or drain a larger volume of fluid). Given the challenge of reducing the head losses, which, as stated, the skilled person faces, then the skilled person will usually strive to design a valve having as large a flow passage as possible to enable accumulating a larger control volume, as necessary, that will result in slowing down the valve’s speed of response to the closing and opening commands.

Skilled persons designing valves are also challenged by the need to give the internal surface of the valve that is exposed to the flow of water higher resistance to cavitation conditions. Hydraulic valves are exposed over time to pressures, which could change considerably and frequently in a way that produces cavitation phenomenon, i.e. the collapse of a layer of small cavities by fluids that produce local jets, which in our case, are stressed to internal surfaces of the valve and cause its erosion over time. Therefore, skilled persons will strive to design a valve that from the outset will minimize the risk of cavitation phenomenon as well as ensuing damages (for instance, by the running up of the anticipated jets against the internal surfaces made of relatively soft material, such as plastic or rubber, which has the ability to absorb the effect of the“explosion” of the cavities (bubbles), in a way that reduces the wear and tear thereby caused).

As a rule, valves are required to respond quickly given the need to regulate pressures. When the valve is installed in a system where the consumption of the fluid from it varies, then the volumetric flow rate in the system changes according to the downstream consumption from the valve, whereby low consumption raises the pressure inside the valve and high consumption leads to a drop in the fluid pressure inside. In order to prevent damage and high wear due to fluctuations in pressure and the instability of the system, skilled persons face the challenge of designing a valve that will have the quickest regulation response as possible along the time line to ensure constant pressure that is not affected by changes in the volumetric flow rate and will even protect the pipe downstream from the valve against exposure to higher than allowable pressure. In hydraulic diaphragms designed with a weir-like seat, from the time the valve is sealed (the diaphragm is stressed on the seat) the diaphragm member is not symmetrically balanced in terms of its exposure to strains. While the diaphragm portion faces the water inlet, it is exposed on both sides to upstream water pressure (on the one side it is exposed to the water pressure in the conduit leading to the valve and on the other side to the same pressure building up in the command chamber), the diaphragm portion facing the downstream flow - although it is exposed on one side to water pressure, as stated, that builds up in the command chamber - on the other side it is not at all stressed by the pressure (from the time the fluid drains out downstream as a result of the sealing of the valve). In this situation, skilled persons are challenged to design a valve that will prevent or minimize the bow-out phenomenon in the diaphragm portion facing the downstream flow. This phenomenon could cause local deformation in the elastomeric diaphragm member, in a way that could impair the sealing capacity of the valve (due to the detachment of the diaphragm by lateral bow-out in downstream direction and over the weir edge due as said, to the unbalanced stressing by differential pressures of that portion of the diaphragm that is facing downstream).

Skilled persons are often challenged to cope with the integration of a hydraulic valve to regulate the flow of a fluid (liquid media), which is unconventional and sometimes used in naturally stringent industries (such as the medical or food industries). In such circumstances, the direct and continuous contact that is likely to take place between a state-of-the-art hydraulic valve sealing mechanism (the diaphragm member and walls of the accumulation (command) chamber) and such a fluid might present difficulties, being a "wet contact" which at least calls for using special and expensive materials for manufacturing those parts that come in direct contact ("wet") with the liquid media flowing in the valve (and even more so when the system is applied in a stringent industry).

Prior to the invention that is the subject of the Patent Application, no design was found in the field of hydraulic valves that offers an integrated and appropriate solution to the challenges described above.

Under these circumstances, prior to the invention that is the subject of the Patent Application, there was therefore a need for an apparatus and method that would enable sealing a hydraulic valve, while providing the valve in which the apparatus and method will be implemented with minimal head losses when it is in an open state (similar to the pipe leading to it), or in other words - the valve when open will have a KV/CV capacity, similar to that of the pipe leading to it; it will give the valve unlimited ability to regulate minimum volumetric flow rates, i.e. it will give the valve the ability to efficiently cope with a wide range of fluid throughputs; the control volume requirement for the valve will not affect the size of the flow passage through it and the quickness of response of closing and opening commands; the valve will be designed with relatively high cavitation resistance and its associated damages; the valve will be designed to respond quickly upon the occurrence of an event that requires a regulating action on its part; the valve in shut mode (sealing) will have a balanced system without the risk of bowing out the elastomeric member; and the valve will allow for the flow of a range of fluids through it.

SUMMARY OF THE INVENTION

The invention, which is the subject of the Patent Application, addresses the challenges described above.

In one aspect, the invention is embodied in an apparatus for tunable regulation of fluid or gas flow, which comprises a fluid conduit that is formed with a fluid or gas flow passage along it, an upstream opening to it on one side, a downstream opening from it on the other side, and a flexible portion that makes up at least part of its circumference and extends at least along an elongated part of the conduit; and a mechanism that comprised an inflatable by fluid or gas means that is adapted once it is inflated for pressing the flexible portion of the conduit to a state of reducing the size of the flow passage in the conduit, and in a way that enables increasing the size of the flow passage in the conduit by the elasticity of the flexible portion from the time the inflatable means is emptied.

In a preferred embodiment of the invention, the conduit has a tubular configuration and the flexible portion extends around its full circumference and, as stated, at least along part of an elongated part of the conduit; the inflatable means is configured as an inflatable wheel (e.g. - inner tube), the axis of which is positioned perpendicular to the flow of the fluid in the conduit and at a distance from it; and from the time the inflatable means is inflated, an arched portion of the inflatable wheel-shaped means (e.g. - inner tube) symmetrically stresses the flexible portion to bend towards the opposite side of the conduit; and when the inflatable means is emptied, an arched portion of the wheel-shaped means comes symmetrically in contact with the flexible portion until the flexible portion reverts to its initial state.

In another aspect, the invention is embodied in a method for tunable regulation of the flow passage in a fluid or gas conduit, which comprise the stages of inflating an inflatable by fluid or gas means that is adapted once it is inflated for pressing a flexible portion that is formed in the conduit to a state of reducing the size of the flow passage in the conduit, and emptying the fluid or gas from the inflatable means in a way that enables again increasing the size of the flow passage in the conduit by the elasticity of the said flexible portion.

In a preferred embodiment of the invention, it is embodied in a hydraulic valve that is fitted with an apparatus for tunable regulation of the flow of fluid or gas, as briefly described above, and which applies in its operation the method for tunable regulation of a flow passage in a conduit for fluid or gas migration, as briefly described above. Other embodiments, configurations and advantages of the apparatus and method for tunable regulation of a flow passage in a fluid or gas conduit will be described below. It should be borne in mind that the configurations described below may be combined with other configurations in different ways, which are at least consistent with one of the principles of the invention described below, and the terminology used here should not be construed as limiting in any way.

BRIEF DESCRIPTION OF THE ATTACHED FIGURE

Different aspects of at least one embodiment of the invention that is the subject of the Patent Application will be described below, with reference to the accompanying figures (while no scale should be attributed to them). The figures are presented for illustrative purposes only and for facilitating an understanding of the different aspects of the invention and the possible configurations for its actual embodiment. The figures are part of the description, but should not be construed as limiting the invention in any way. In the figures, an identical or similar element that is visually depicted in several figures could be tagged by uniform numbering. For clarity, not every element was tagged in each of the figures. In the following figures:

Figs. 1 and 2 are (respectively) schematic views of an example of an apparatus according to the invention for tunable regulation of the flow of fluid or gas in a conduit, depicted in two modes of operation - in a state where the inflatable by fluid or gas means is emptied and in a state where the inflatable means is inflated.

Figs. 3 and 4 are (respectively) schematic views of another example of an apparatus according to the invention for tunable regulation of the flow of fluid or gas having a double flow rate and depicted in two states of operation - in a state where the inflatable by fluid or gas means is emptied and in a state where the inflatable means is inflated.

Figures 5 and 6 are (respectively) schematic views of an apparatus such as the one illustrated in Figs. 1 and 2 that is fitted in a hydraulic valve.

Figs. 7a - 7d are photographs of a prototype built by the Patent Applicant to prove the feasibility of the invention.

Fig. 8 is a schematic view of another variation of an apparatus for tunable regulation of the flow of fluid or gas according to the invention, wherein the inflatable means is replaced by a stressing mechanism that comprises a double chamber actuator.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Various devices and elements will be described below strictly for the purpose of providing an example of an embodiment of the claimed invention. The embodiment described below does not limit the claimed invention, and the latter may also apply to different apparatuses and methods that those described below. The claimed invention does not have to include all aspects of the apparatuses, elements and methods described below, and is not strictly limited to those that exist in all the configurations described below. For the sake of integrity, it should be noted that the set of claims on the invention may be revised by way of amendment and/or by filing a divisional application. The skilled person will also understand that, for the sake of clarity, the configurations are described without delving into a lengthy description of elements, methods and processes that are already basic principles in the field and for which no tagged reference was provided in the figures.

Reference is made to Figs. 1 and 2. Figs. 1 and 2 are (respectively) schematic views of an example of apparatus 10 of the invention for tunable regulation of the flow of fluid or gas in conduit 15 depicted in two states of operation - in a state where inflatable by fluid or gas means 20 is emptied and in a state where the inflatable means is inflated.

According to the illustrated example, apparatus 10 comprises fluid conduit 15. Conduit 15 is formed with passage 25 for the flow of fluid or gas along it, upstream port 30 to it on one side, downstream port 35 from it on the other side, and flexible portion 40.

Flexible portion 40 may be made of an elastomer (e.g. natural rubber). According to the illustrated example, conduit 15 has a tubular configuration wherein flexible portion 40 fully extends around its circumference and along an elongated part of the conduit, but in light of the explanations to be provided below, a skilled person will understand that flexible portion 40 could only extend around part of the circumference of the conduit.

As mentioned, apparatus 10 is comprised of inflatable by fluid or gas means 20. According to the illustrated example, inflatable means 20 is configured as an inflatable inner tube (wheel shaped) whose axis 45 is positioned perpendicular to the fluid flow passage in conduit 15 and at a distance (L) from it.

Inflatable means 20 may be made of elastomer (e.g. natural rubber), similar to the inner tube of a vehicle tire, and is comprised of valve 50, which enables emptying it and inflating it with fluid (e.g. water or oil) or gas (e.g., air). The skilled person will understand that inflatable means 20 is only one assembly in mechanism 55, which allows for the controlled emptying and inflation of inflatable means 20. Emptying and inflation of inflatable means 20 may be controlled by a system (not illustrated), which allows for autonomously emptying or inflating (e.g. depending on the upstream pressure of the fluid or gas) or in a controlled manner by remote control (e.g. giving a command by remote control for emptying inflatable means 20 upon receiving an indication of high upstream pressure).

The skilled person will also understand that the wheel-shape configuration of inflatable means 20 is just an example, and the means could also be designed with inflatable configurations having other and different geometries (that are not wheel-shape as illustrated).

In the state illustrated in Fig. 2, inflatable by fluid or gas means 20 is adapted from the time it is inflated for pressing flexible portion 40 to a state of reducing the size of the flow passage in conduit 15 (as well as the possibility of completely closing the passage (not illustrated)). According to the illustrated example, inflatable means 20 induces arch-like portion 60 of the inflatable wheel-shaped means (e.g. - inner tube) to symmetrically stress flexible portion 40 to bend towards opposite side wall 65 of conduit 15.

The skilled person will understand that from the time inflatable means 20 is emptied, then by the elasticity of flexible portion 40, apparatus 10 may return to its state as illustrated in Fig. 1. In other words, to again increase the size of the flow passage in conduit 15. According to the illustrated example, when inflatable means 20 is emptied, arch-like portion 60 of the emptying wheel becomes increasingly smaller in size, while staying in symmetrical contact with flexible portion 40 and is pushed back when it retracts by the elasticity of flexible portion 40 until flexible portion 40 reverts to its initial state (as illustrated in Fig. 1), (an open state that allows for an uninterrupted free flow of fluid or gas in the conduit).

The skilled person will understand that inflating inflatable by fluid or gas means 20 could result in fully sealing the flow passage in the conduit (by stressing it into sealing contact with opposite side 65), in preventing the passage of fluid or gas in the conduit. In other words, the apparatus of the invention may serve not only for continuous and tunable regulation of the flow in the conduit, but also for completely closing and stopping the flow.

The skilled person will also understand that an apparatus of the invention is not limited in terms of its downstream geometry. It can also be applied in other and different geometries and not necessarily as a direct continuation along the axis of the conduit (e.g. in a vertical, horizontally-tilted, angular configuration).

Furthermore, the symmetrical configuration of the invention in terms of stressing the flexible portion enables a two-way flow throughput (in two directions intermittently from two sources of supply or for filling and emptying while passing through the same apparatus).

According to the illustrated example, apparatus 10 also comprises package 70, which is formed with openings on both sides, for passing conduit 15 through it and is adapted to contain conduit 15 and inflatable means 20 inside it. Package 70 may be formed as a case made of plastic or another material, which allows for convenient and secure transport and placement (against ravages of the weather, tampering or changing) of the apparatus as rather an all in a box package.

Therefore, according to the illustrated example, the invention is implemented as a closed wheel-shaped pressing means with an internal volume that is inflatable by fluid or air. A pressing means positioned against a flexible portion of the flow conduit that can be squashed and released. When pressure is released from the inflatable means, it releases the full or partial squashing of the conduit (until the flow passage is fully opened). Full opening of the flow passage ensures a free and uninterrupted flow in the conduit. According to the illustrated example, the portion that is pressed by the inflatable means is a flexible part of the conduit that can be squashed and opened in a cyclical and unrestricted manner. Furthermore, the arched configuration of the contact area between the inflatable means and the flexible portion induces constant and balanced stressing of the flexible portion also in a state of full sealing (closure) of the flow passage in the conduit. The wheel-shaped configuration of the inflatable means distributes the forces it exerts circumferentially and equally, whereby the flexible portion of the conduit is pressed symmetrically and equally and is easily bent (if the inflation pressure of the inflatable means in the apparatus is high, the resistance of the fluid pressure in the conduit may be negligible in this context).

In light of the explanations given above with reference to Figs. 1 and 2, a skilled person will understand that a hydraulic valve, in which the apparatus of the invention will be embodied for tunable regulation of the flow of fluid or gas through it, will have considerable hydraulic advantages which skilled persons in the art strive to achieve (compare above to the “Background of the Invention” chapter) - An apparatus such as apparatus 10 may provide the valve with minimal head losses at a rate similar to a pipe streaming fluid or gas through it (KV/CV values similar to those in the feeding pipe). When fully opened, the apparatus allows for an uninterrupted flow since the flow passage varies up to the full diameter of the feeding pipe. Such an apparatus also provides precise regulation capabilities achieved due to the sealing method by pressing an inflatable means that changes its diameter and its area of contact with the flexible portion to a fully sealed state when the sides of the flexible portion touch each other.

An apparatus such as apparatus 10 provides the ability to regulate a wide range of flow throughputs, without a minimum flow throughput. The apparatus implements in its operation contact of a flexible and soft means in itself (the inflatable means) with the flexible and soft portion of the conduit (flexible/soft - flexible/soft interface). This provides the ability to adjust the flow rate according to the momentary flow throughput, without fluctuations in downstream pressure (caused as a result of the widespread use in valves today of elastomer diaphragm interfaces with a seat that is relatively rigid and require adding, at the very least, expensive and cumbersome throttle accessories for handling low flow throughputs at the cost of the formation of head losses) and in reducing wear and tear over time (as these are expressed in elastomer diaphragm interfaces with a seat that is relatively rigid and as said, are commonly used in valves today).

An apparatus such as apparatus 10, which can be operated by means of control volume dependent on the diameter of the controlled pipe (the volume of fluid or gas needed to open it is the same as the volume derived from the portion length and the diameter of the controlled pipe variables). The apparatus provides, as stated, minimal head losses when fully opened, while closing it by hydraulically pressing on a flexible portion of the conduit only requires pushing a given volume of fluid or gas from the conduit, and reopening it only requires releasing the flexible portion of the conduit from the stressing of the inflatable means.

An apparatus such as apparatus 10 may be made in a way that renders its internal structure highly cavitation-resistant. The apparatus sets a high anti-cavitation threshold due to the minimal head losses in an open state, and should cavitation form, the jets that form from the collapse of the bubbles pop in the apparatus of the invention on material that is naturally soft (the flexible portion of the conduit), which naturally has a preferred ability to absorb the erosion effect that is created. An apparatus such as apparatus 10 may provide the valve with preferred quick response capabilities when regulation is required. It is enough to push a small amount of fluid or gas streamed into the system in order to throttle the flow passage, while to open the passage it is enough to drain a small amount of the inflatable means and release the pressure from it to the atmosphere. The apparatus of the invention requires low operating and closing pressures.

An apparatus such as apparatus 10 is operated in a balanced and symmetrical manner, and in a closed state is not sensitive to lateral bow-out. An inflatable means configured as an inner tube (wheel- shaped) is closed in its circumference and balanced so that the forces exerted outwardly are equal around its circumference. The inner tube (wheel- shaped) configuration allows for balanced and symmetrical pressing of the flexible portion of the conduit to fully seal the flow passage, wherein the flexible portion is constantly supported on the surface of the inflatable means that is stressed for continuous contact with it.

An apparatus such as apparatus 10 applies a "dry" pressing mechanism (the inflatable means) that does not come into contact with the media (fluid or gas) streamed in the system. As opposed to the apparatus of the invention, prior art hydraulic valves implement a“wet” sealing mechanism that has to be pre-adjusted to the fluid or gas medium flowing through it.

Furthermore, a hydraulic valve in which the apparatus of the invention, such as apparatus 10, will be implemented, will provide additional advantages of a relatively simple and inexpensive structure due to the use of a flexible conduit portion that may be relatively easily adjusted to the work conditions, to handle the regulation of pressures, high flow throughputs and different types of fluid and gases. The "dry" pressing mechanism is external and does not come into direct contact with the fluid or gas flowing through the valve. Incorporating the valve in an“all in a box” package protects the system, enables pre-packaging the command and control systems, and provides convenient and safe transport and installation capabilities. Valve maintenance (if required) (e.g. servicing the inflatable means) does not call for dismantling it from the line (as the inflatable means is external to the flow conduit). The inflatable means implemented in accordance with the invention also makes redundant and avoid the need for a spring as commonly used in a diaphragm based hydraulic valves for assisting the diaphragm movement toward closing the valve.

The apparatus of the invention may also be used as a double throughput hydraulic valve. Reference is made to Figs. 3 and 4. Figs. 3 and 4 are (respectively) schematic views of another example of apparatus 310 of the invention for tunable regulation of the flow of fluid or gas having a double flow rate depicted in two states of operation - in a state where the inflatable by fluid or gas means 210 is empty and in a state where the inflatable means is inflated.

In addition to first conduit 315, apparatus 319 comprises a second conduit -‘315, which is positioned in tandem with and parallel to first conduit 315 and at a distance from it (according to the illustrated example, at a distance of 2L). Inflatable means 320 is positioned between the first and second conduits, whereby its axis 345 is positioned perpendicular to the fluid or gas flows in conduits 315 and‘315. As illustrated in Fig. 4, when inflating inflatable means 320, arched portions 360 and ‘360 of the inflatable wheel-shaped means (e.g. - inner tube) simultaneously stress flexible portions 340 and‘340 of the conduit to symmetrically bend towards opposite sides 365 and‘365 of the conduits (including to the point of total closure of the flow passages in the conduits, as illustrated in Fig. 4). When inflatable means 320 is emptied, arched portions 360 and‘360 of the emptying wheel increasingly shrink in size, while staying in symmetrical contact with flexible portions 340 and ‘340 until flexible portions 340 and‘340 return to their initial state (as illustrated in Fig. 3), (an opening state that concomitantly allows uninterrupted free flows in both conduits 315 and‘315).

A skilled person will understand that this embodiment of the invention enables handling high flows. One inflatable means (320) actually enables doubling the volumetric flow rate of the hydraulic valve, while maintaining the advantages of the invention indicated hereinabove.

In light of the description given above, with reference to the accompanying figures, the skilled person will appreciate the fact that the mode of operation of an apparatus, such as apparatus 10 or 310, also embodies a general method for tunable regulation of the fluid or gas flow passage in a conduit (15, 315,‘315). A method that comprises the stages (steps) of inflating an inflatable by fluid or gas means (20, 320) that is adjusted once it is inflated for pressing a flexible portion (40, 340,‘340) that is formed in the conduit to a state of reducing the size of the flow passage in the conduit, and emptying the fluid or gas from the inflatable means in a way that enables again increasing the size of the flow passage in the conduit by the elasticity of the said flexible portion. A general method that may also comprise the stage of inflating the inflatable means with fluid or gas in a manner that leads to sealing of the flow passage and preventing the passage of flow in the conduit.

In light of the description given above, with reference to the accompanying figures, a skilled person will understand that an apparatus of the invention may be implemented in a hydraulic valve having a structure that comprises other commonly-used elements and structural characteristics known in the field of hydraulic valves. Reference is made to Figs. 5 and 6. Figs. 5 and 6 are (respectively) schematic views of apparatus 510, similar to apparatus 10 (illustrated in Figs. 1 and 2) fitted in hydraulic valve 511.

According to the illustrated example, inflatable means 520 is inflated by the upstream pressure prevailing in the valve.

Apparatus 510 comprises moving seat element 512 which is fixed to inflatable means 520. According to the illustrated example, moving seat 512 is formed as a sort of narrow strip that protrudes from the cylindrical wheel-shaped surface of the inflatable means, extending across it and is designed for contact with flexible portion 540. On the other side of conduit 515, hydraulic valve 511 is formed with counter-seat 513. Counter-seat 513 is also formed as a narrow strip that protrudes from the inner surfaces of the valve, extends across it, and is designed to come into contact with the outer surfaces of conduit side 515 against which flexible portion 540 will be stressed when inflatable means 520 is inflated and moving seat 512 is stressed against it.

The skilled person will understand that the design of a hydraulic valve, such as valve 511, with said moving seat and counter-seat, may ensure improved collapsibility of the flexible portion followed by sealing. This is due to the concentration of the stress exerted from the time inflatable means is inflated over a relatively small surface.

At the same time, in light of Figs. 5 and 6, the skilled person will understand that valve 511 has structural characteristics that as stated are common and familiar in the field of hydraulic valves, such as valve's body member 514 that could be made of metal or plastic, for example; end connectors 516 that may be formed with a peripheral groove or alternatively end connectors 517 that are formed with threading or end connectors 518 that are formed with a flange for connecting the valve to an upstream and downstream pipes; and peripheral fasteners 519 (e.g. - fastenable bands of plastic or metal) which in a conduit of the invention serve to fasten rigid portions of the conduit to its flexible portion.

Furthermore, the Patent Applicant proved the applicability of the invention in experiments. Reference is made to Figs. 7a - 7d. Figs. 7a - 7d are photographs of a prototype that was implemented by the Patent Applicant to prove the feasibility of the invention.

The prototype proves its efficiency as apparatus 710 for tunable regulation of a flow of fluid (water). Apparatus 710 is comprised of a water conduit 715 having a tubular configuration with a passage for the flow of fluid along it, upstream opening 730 on one side, downstream opening 735 on the other side, and flexible portion 740 section that spans around its full circumference. In the photographed prototype, these are sections of 1” diameter PVC pipes, wherein the flexible portion is formed of a 1.5” diameter rubber tube with a wall thickness of 3mm, which is suitable for operating at pressure of up to 16 bar. Apparatus 710 also includes mechanism 755 which is comprised of inflatable by water means 720, which is adjusted when inflated to press flexible portion 740 to a state of reducing the size of the flow passage in conduit 715, and in a way that enables increasing the size of the flow passage in the conduit by the elasticity of the flexible portion once the inflatable means is emptied out. The photographed prototype shows inflatable wheel 720 (an 8” grass mover wheel), which is inflated by the pressure of the upstream water routed through pipe 757 (an 8” rubber pipe) and passes through them through a separation tap with pressure meter 759, and three-way tap 761 (that allows for close, open, and automatic states). Axis 745 of inflatable wheel 720 is positioned perpendicular to the fluid flow passage in conduit 715 and at a distance from it. Photographed prototype shows an axis anchored to the sides of package 770 (in the prototype - a wooden package that allows all elements of the apparatus to be incorporated inside).

Photographed apparatus 710 was exposed during experiments to stream of water at maximum static pressure of up to 5 bar when the maximum volumetric flow rate (throughput) was 5 cubic meters per hour. Under these variable conditions, the operating pressure (closing and opening) achieved by the apparatus was 1 meter (0.1 bar). In other words, the operating and closing pressures of the apparatus of the invention were very low, a result which indicates the applicability of the invention also in a very low pressure environment. No limitation of minimum volumetric flow rate was revealed in the tests, and the operation of the apparatus did not require limiting the regulation ratio. It was also found that the apparatus operates relatively quietly, even with an increase in the regulation ratio and a decrease in the volumetric flow rate.

In addition, a skilled person will understand that instead of an inflatable means, one can at least achieve most of the advantages of the invention described above, in referring to the accompanying figures, also by means of a double chamber actuator. Reference is made to Fig. 8. Fig. 8 is a schematic view of another variation of apparatus 810 for tunable regulation of the flow of fluid or gas of the invention, wherein the inflatable means is replaced by stressing mechanism 821 that comprises a double chamber actuator 823. Persons of skill in the hydraulic valve field are familiar with the double chamber actuator, which is a commonly-used assembly in the field. In the said valve 811, moving seat 825 was installed wherein it is connected to moving element 827 of double chamber actuator 823. According to the illustrated example, the moving seat is formed as a sort of narrow strip that extends like a "guillotine" across tubular conduit 815, and is designed for contact with flexible portion 840 of the conduit. On the other side of conduit 815, hydraulic valve 811 is formed with counter-seat 829. Counter-seat 829 is also formed as a narrow strip that protrudes from the inner surfaces of the valve, extends across it, and is designed to come into contact with the outer surfaces of conduit 815 against which flexible portion 840 will be stressed when moving seat 825 is stressed against it.

Thus, moving seat 825 is adapted from the time of its movement to press flexible portion 840 to a state of reducing the size of the flow passage in conduit 815 (including completely closing it as illustrated in the example depicted in the figure), in a way that enables increasing the size of the flow passage in the conduit by the elasticity of the flexible portion, upon the retraction of moving element 827 to which moving seat 825 is connected as stated. The use of a relatively narrow moving seat also enables having a large ratio of areas between the diaphragm of the double chamber actuator and the seat, thereby enabling reducing the size of the actuator.

A skilled person will understand that this alternative configuration may at least achieve most of the advantages mentioned above, in view of implementing also here, a prominent characteristic of this invention - routing the fluid or gas streamed in an hydraulic valve to a fluid conduit, which is formed with a fluid flow passage along it, an upstream opening on one side, a downstream opening on the other side, and a flexible portion which at least comprises part of its circumference and extends at least along an elongated part of the conduit.

Therefore, a skilled person will appreciate the fact that the invention that is the subject of the Patent Application introduces an apparatus and method that would enable sealing a hydraulic valve, while providing the valve in which the apparatus and method will be implemented with minimal head losses when it is in open state (similar to the pipe leading to it), or in other words - the valve when open will have a KV/CV capacity which is similar to that of the pipe leading to it; it will give the valve pressure regulating ability without limitation of minimum volumetric flow rate, i.e. it will give the valve the ability to efficiently cope with a wide range of fluid throughputs; the control volume requirement for the valve will not affect the size of the flow passage through it and the quickness of its response to closing and opening commands; the valve will provide for relatively high resistance against the cavitation phenomenon and the anticipated damages should it occur; the valve will be designed to respond quickly upon the occurrence of an event that requires a regulating action on its part; the valve in shut state (sealing) will have a balanced system without the risk of bow-out of the elastomeric member; and the valve will allow for the flow of a wide range of fluid types through it.

The Patent applicant provided the above description in referring to the accompanying figures for illustrative purposes only. The description above should not be limited to the illustrated figures. On the contrary, the description provided should be seen as also covering a wide range of alternatives, adjustments and equivalents, all without deviating from the embodiments defined in the following set of claims.

Claims

1. An apparatus for tunable regulation of the flow of fluid or gas that is comprised of - a conduit for fluid or gas that is formed with a fluid or gas flow passage along it, an upstream opening to it on one side, a downstream opening from it on the other side, and a flexible portion that makes up at least part of its circumference and spans at least along an elongated part of the conduit; and

a mechanism that is comprised of an inflatable by fluid or gas means that is adapted once it is inflated for pressing said flexible portion to a state of reducing the size of the flow passage in said conduit, and in a manner that enables increasing the size of the flow passage in the conduit by the elasticity of said flexible portion once said inflatable means is emptied.

2. The apparatus for tunable regulation of the flow of fluid or gas of Claim 1 , wherein - inflating said inflatable means with fluid or gas results in fully sealing and preventing the passage of fluid in said conduit.

3. The apparatus for tunable regulation of the flow of fluid or gas of Claim 1 , wherein - said inflatable by fluid or gas means is inflated by the fluid or gas pressure prevailing upstream of said apparatus.

4. The apparatus for tunable regulation of the flow of fluid or gas of Claim 1 , wherein - said conduit has a tube-like configuration and said flexible portion extends around its full circumference and, as said, at least along part of said conduit length; and said inflatable means is configured as an inflatable wheel the axis of which is positioned perpendicular to the flow of the fluid in said conduit and at a distance from it; and wherein - upon inflating said wheel-shaped inflatable means, an arched portion of said inflatable wheel symmetrically stresses said flexible portion to bend towards the opposite side of said conduit; and

upon empting out said wheel-shaped inflatable means, an arched portion of said emptying wheel remain symmetrically in contact with said flexible portion until said flexible portion reverts to its initial state.

5. The apparatus for tunable regulation of the flow of fluid or gas of Claim 4, wherein - said apparatus comprises, in addition to said conduit, also a second conduit that is positioned in tandem with said first conduit and at a distance from it, and wherein - said inflatable means is positioned between said first and second conduits, whereby its axis is positioned perpendicular to the fluid or gas flows in said first and second conduits, and wherein - upon inflating said inflatable means, arched portions of said inflatable wheel symmetrically stress said flexible portions of both conduits to bend towards the opposite sides of said conduits; and

upon empting out said wheel-shaped inflatable means, said arched portions of said emptying wheel remain symmetrically in contact with said flexible portions until said flexible portions revert to their initial state.

6. The apparatus for tunable regulation of the flow of fluid or gas of Claim 4, wherein - said apparatus comprises in addition a moving seat that is fixed to said inflatable means, while it protrudes above its wheel-shaped surface and is adapted for contact with said flexible portion when said inflatable means is inflated.

7. The apparatus for tunable regulation of the flow of fluid or gas of Claim 6, wherein - said apparatus comprises in addition a stationary counter-seat that is positioned opposite said moving seat, but on the other side of said tubular conduit, in a way that from the time said inflatable means is inflated, the moving seat presses said flexible portion towards said stationary seat.

8. The apparatus for tunable regulation of the flow of fluid or gas of Claim 1 , wherein - said apparatus comprises in addition a package, which is formed with openings on both sides, for the passage of said conduit through it, and is adapted to incorporate said conduit and said inflatable means inside it.

9. The apparatus for tunable regulation of the flow of fluid or gas of Claim 1 , wherein - said apparatus comprises in addition a system for controlling the inflation and emptying of said inflatable means in a way that allows for a varying regulation of said conduit flow passage by reducing or increasing the size of the flow passage.

10. A method for tunable regulation of the flow passage in a fluid or gas conduit that comprises the stages of - Inflating with fluid or gas of an inflatable means which is fitted from the time it is inflated to press a flexible portion that is formed in flow conduit to a state of reducing the size of the flow passage in the conduit; and

emptying the fluid or gas from said inflatable means in a way that allows for again increasing the size of the flow passage in said conduit by the elasticity of said flexible portion.

11. The method for tunable regulation of a flow passage in a fluid or gas conduit of Claim 10, wherein said method comprises in addition the stage of - inflating said inflatable means with fluid or gas in a way that leads to fully sealing off and preventing the flow passage in said conduit.

12. A hydraulic valve that is fitted with an apparatus for tunable regulation of the flow of fluid or gas according to any of Claims 1-9, and which implement in its operation the method for tunable regulation of a flow passage in a fluid or gas conduit according to any of Claims 9-11.

13. An apparatus for tunable regulation of the flow of fluid or gas of Claim 1, wherein - instead of the said inflatable means, said mechanism comprises a stressing mechanism that comprises - a double chamber actuator; and

a moving seat that is connected to the moving element of said double chamber actuator; and wherein - said moving seat is adapted from the time of its movement to press said flexible portion to a state of reducing the size of the flow passage in said conduit, and in a way that enables increasing the size of the flow passage in the conduit by the elasticity of said flexible portion, upon retraction of said moving element to which said moving seat is connected.