Embodiments of the invention relate to a pulsating device.
In such devices, the incoming fluid flow may be of relatively low flow and the ejected pulses may be transformed to be of a relatively high flow. Pulses emitted by pulsating devices can therefore be designed to reach relative large distances in relation to conventional non pulsating devices that would require much higher flow rates in order to reach similar distances. As a result, basing an irrigation system on a pulsating device can reduce some of the expenses associated with such an irrigation system such as for example the energy consumed by the system.
Israeli patent No. 92886 describes a pulsating device with a chamber and a hollow stem that extends through the chamber to an outlet orifice of the chamber. The device also includes a displaceable valve member that is disposed in the chamber under the outlet orifice. Upon rise of pressure in the chamber the valve can be contracted from a position where it closes to the orifice to a position where it is displaced from the orifice to allow a pulse of water to exit the device.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.
In an embodiment of the present invention there is provided a pulsating device for transforming a liquid flow entering the device from a liquid source upstream to an intermittent pulsating liquid flow ejected from the device downstream, the device comprising a chamber for receiving the liquid flow entering the device and gas that occupies an initial volume in the chamber, the liquid entering the chamber being adapted to compress the gas and decrease the volume that the gas occupies in the chamber and increase the pressure in the chamber, the device further comprises a valve that is adapted to open above a first threshold pressure Po within the chamber to begin a liquid pulse that exists the chamber and after being opened to close below a second threshold pressure Pc within the chamber to end the liquid pulse exiting the chamber, wherein the device also comprises an outlet gate that communicates between the interior and the exterior of the chamber, and the liquid in the chamber can exit the chamber via the outlet gate when the pressure in the chamber at the outlet gate is above zero.
Optionally, the device comprises an inlet gate that is formed in the chamber and communicates between the interior and the exterior of the chamber, and air from outside of the chamber can enter the chamber when the pressure in the chamber at the inlet gate is below zero.
Typically, the pressure of the liquid at the liquid source is greater than the first threshold pressure Po.
Optionally, the flow rate of each pulse at any point between its beginning and end is greater than the flow rate of liquid entering the chamber via the inlet.
If desired, relative to a lower end of the chamber at pressure Po the height of liquid in the chamber is Lo and at pressure Pc the height of liquid in the chamber is Lc which is lower than Lo.
Optionally, relative to a lower end of the chamber at pressure Po the height of liquid in the chamber is Lo and at pressure Pc the height of liquid in the chamber is Lc which is lower than Lo, and the inlet gate communicates with the chamber at a point that is lower than Lc.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.
Attention is first drawn to
It is noted that references to pressure made herein are all expressed in terms of deviation from the atmospheric pressure that exists in the environment outside of the device which is defined as “zero”. Also it is noted that directional terms appearing throughout the specification and claims, e.g. “forward”, “rear”, “up”, “down” etc., (and derivatives thereof) are for illustrative purposes only, and are not intended to limit the scope of the appended claims. Finally it is noted that the directional terms “down”, “below” and “lower” (and derivatives thereof) all define identical directions.
Attention is additionally drawn to
Attention is additionally drawn to
The valve 16 that opens at pressure Po in the chamber 18 begins a pulse of liquid that starts to exit the chamber 18 and pipe section 24 towards the emitting portion 14 where it is emitted to the outside environment. As liquid exits the chamber 18 the pressure in the chamber 18 drops, the gas 26 that is trapped at the upper portion of the chamber 18 expands and the level of liquid in the chamber 18 decreases (
As long as the device 10 remains in liquid communication with the pressurized liquid source upstream, the termination of a given pulse will be followed by a subsequent rise of pressure in the chamber 18 (
In an embodiment of the present invention it is also possible to configure the inlet 20 to the chamber 18 to be of a regulated type. Such a regulated inlet can ensure that the flow rate of liquid entering the chamber 18 is substantially constant and independent of the pressure differences that are formed between the liquid pressure at the liquid source upstream and the liquid pressure in the chamber 18 that varies during the formation of the pulses. By configuring the liquid flow entering the chamber to a substantially constant rate it is easier to avoid reaching the above mentioned equilibrium between the liquid entering the chamber and the liquid exiting it, that may stop the formation of the pulses.
During experiments with a pulsating device 10 generally similar to that described above, it was observed by the inventor of the present invention that over time at least some of the substances of the gas 26 that is trapped in the chamber 18 may in some cases dissolve into the liquid that it contacts in the chamber 18. This may lead to a drop in the amount of gas 26 that is present in the chamber 18 in gas form and as a result to a decline in the performance of the pulsating device 10. Therefore, in an embodiment of the present invention the pulsating device 10 is equipped with an outlet gate 28 that is adapted to allow liquid in the chamber 18 to seep out of the chamber 18, along a second exit path different from the first exit path, when the pressure in the chamber 18 at the outlet gate 28 is above “zero”. And, optionally the pulsating device 10 is also equipped with an inlet gate 30 that is located above the outlet gate 28 and is adapted to allow air to seep into the chamber 18 when the pressure in the chamber 18 at the inlet gate 30 is below “zero”, i.e., when the pressure in the chamber 18 is less than the pressure outside the chamber 18.
In embodiments of the pulsating device 10 that include the outlet gate 28, each time the pulsating device 10 is turned off and put to rest between irrigation cycles the chamber 18 can be emptied from its liquid via the outlet gate 28. In embodiments that include also the inlet gate 30 new air can enter the chamber 18 via the inlet gate 30 when it is emptied. When a new irrigation cycle starts by for example renewing the supply of pressurized liquid that enters the chamber 18 via the inlet 20, liquid will again start to fill the chamber 18 and the pulsating sequence will resume.
During a pulsing sequence when the pressure in the chamber 18 varies between the first threshold pressure Po and the second threshold pressure Pc; a small amount of liquid will constantly seep out of the chamber 18 via the outlet gate 28. When irrigation stops, liquid will continue to seep out of the outlet gate 28 as long as there is liquid in the chamber 18 above the outlet gate 28 that forms a pressure greater than “zero” within the chamber 18 at the outlet gate 28. During the emptying of the chamber 18 from liquid the pressure in the gas 26 above the liquid drops to “zero” and then continues to drop to below “zero”. When the level of liquid in the chamber 18 reaches a position below the inlet gate 30 and when the pressure above the liquid is below “zero” then the inlet gate 30 will allow air from outside of the chamber 18 to seep into the chamber 18 and “charge” the chamber 18 with new air in gas state.
In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
Although the present embodiments have been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.
This is a 35 USC 371 U.S. National Phase of International Application No. PCT/IB2012/053014, filed 14 Jun. 2012 and published in English as WO 2013/008110A1 on 17 Jan. 2013, which claims priority to U.S. Provisional application No. 61/507,124, filed 13 Jul. 2011. The contents of the aforementioned applications are incorporated by reference in their entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2012/053014 | 6/14/2012 | WO | 00 | 1/3/2014 |
Publishing Document | Publishing Date | Country | Kind |
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WO2013/008110 | 1/17/2013 | WO | A |
Number | Name | Date | Kind |
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1090244 | Staples | Mar 1914 | A |
3372899 | McPherson | Mar 1968 | A |
4113181 | Sheets | Sep 1978 | A |
5738136 | Rosenberg | Apr 1998 | A |
5950676 | Rosenberg | Sep 1999 | A |
20070119975 | Hunnicutt | May 2007 | A1 |
20120312894 | Keren | Dec 2012 | A1 |
Number | Date | Country |
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760596 | Feb 1934 | FR |
92886 | Jul 1995 | IL |
Entry |
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International Search Report dated Oct. 2, 2012 issued in PCT counterpart appication (No. PCT/IB2012/053014). |
Written Opinion dated Oct. 2, 2012 issued in PCT counterpart appication (No. PCT/IB2012/053014). |
Number | Date | Country | |
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20140138453 A1 | May 2014 | US |
Number | Date | Country | |
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61507124 | Jul 2011 | US |