WO2013006060A2

WO2013006060A2 - An intermittent water irrigation system

Info

Publication number: WO2013006060A2
Application number: PCT/NL2012/050492
Authority: WO
Inventors: Peter Jan van der Molen; Johannes Wilhelmus VAN TUIL; Diederik Ter Hoeven
Original assignee: Balotciv Ip B.V.
Priority date: 2011-07-07
Filing date: 2012-07-09
Publication date: 2013-01-10
Also published as: WO2013006060A3; NL2007061C2

Abstract

An intermittent water irrigation system comprises a water supply device and a network of one or more water ducts connected or to be connected to said water supply device. The water supply device is adapted for controlled variation of water pressure in the one or more water ducts of the network. At least one water duct has a plurality of water emitters, each water emitter being adapted to emit intermittently portions of water. Each water emitter comprises a variable volume chamber and associated variable volume chamber restoring means. A variable volume chamber has a water outlet for passing water from the variable volume chamber, wherein an outlet valve is associated with said outlet, and a water inlet in communication with the water duct, wherein an inlet valve is associated with said water inlet. The variable volume chamber has a volume that is reduced upon increased pressurization of water in the water duct, and that is increased, at least aided by said variable volume chamber restoring means, when the increased pressurization of water in the water duct is removed. The inlet valve is configured to close the water inlet upon increase of pressurization of the water in the water duct so that water is then passed from the chamber via the water outlet.

Description

AN INTERMITTENT WATER IRRIGATION SYSTEM

The present invention relates to an intermittent water irrigation system.

The inventive water irrigation systems is primarily proposed for watering crops, plants, vegetables, trees, flowers, etc., e.g. via water the soil or another substrate, or a (hydroponic) container wherein they are grown. The system may be used for the watering of entire crop fields or landscapes, e.g. lawns. The system may be used outdoors, but also indoors, e.g. in greenhouses, office buildings, or family homes.

The system includes a water supply device and a network of one or more water ducts connected or to be connected to said water supply device. The water supply device is adapted for controlled, e.g. periodic, variation of the water pressure in the one or more water ducts of the network, and at least one water duct has a plurality of water emitters, each water emitter being adapted to emit intermittently portions of water. US 3797741 discloses an intermittent water irrigation system having a manifold water duct connected to a plurality of emitter lines, wherein a pressure sensitive valve governs the entry of a volume water into each emitter line. The valve operation is controlled by periodic variation of the water pressure in the manifold line. Each emitter line is provided with a series of openings, allowing the water to drain from the emitter line.

The present invention aims to provide an improved intermittent water irrigation system or at least a useful alternative for existing water irrigation systems.

The present invention also aims to provide an intermittent water irrigation system that allows for optimal control of the volume of water that is dispensed by each water emitter, thereby allowing to control the irrigation process.

The present invention also aims to provide an intermittent water irrigation system that allows to provide an additional fluid, e.g. atmospheric air or a liquid, in an intermittent manner.

The present invention achieves one or more of the above objects by providing an intermittent water irrigation system according to claim 1. The inventive system, in use, dispenses from each water emitter a metered dose of water per operating cycle. This allows for optimal control of the irrigation. In a practical embodiment the volume of a metered dose may lie in the range between 0.5 and 200 ml, although other volumes are also envisaged.

The invention is based on the insight that an effective opening force can be exerted on the movable closure member, thereby opening the water inlet valve, by the atmospheric pressure acting on one surface of the closure member and the underpressure in the variable volume chamber acting on another surface of the closure member in the situation that the pressurization of the water in the water duct is removed or at least reduced.

In a preferred embodiment the variable volume chamber of the water emitter, or of an additional pump as will be explained below, is delimited by a cylinder and a piston that is reciprocable in the cylinder. In an alternative the chamber is embodied as a bellows or other deformable wall type chamber.

In a preferred embodiment the inlet valve of the water emitter is arranged in the piston, so as to move along with the piston. In a practical embodiment a variable chamber restoring spring is provided, e.g. mounted in the variable volume chamber, e.g. of suitable spring steel or of plastic.

In a preferred embodiment the outlet valve is a self-closing valve, preferably a duckbill valve. In an embodiment the inlet valve of the water emitter comprises a restoring means that provide a restoring force urging the movable inlet valve member towards its seat.

In a preferred embodiment the inlet valve of the water emitter comprises at least one flexible diaphragm fastened at its outer periphery to the piston or to a valve body mounted on the piston, a first surface of the flexible diaphragm being in communication with the atmosphere and a second surface of the diaphragm being in communication with the variable volume chamber. The pressure difference on opposed surfaces of the one or more diaphragms then acting to cause a suitable opening force for the inlet valve when such opening is required in the dispensing cycle.

In an embodiment the water emitter has a setting means allowing to set the volume of a water portion to be dispensed, e.g. between multiple distinct maximum volumes of a portion to be dispensed. For example the setting means are adapted to provide multiple positions of the stroke of the piston.

In a preferred embodiment the piston of the water emitter has a stepped diameter structure, having a portion with a first diameter at the side delimiting the variable volume chamber, which first diameter portion is reciprocable in a corresponding diameter portion of a bore of the cylinder so that the first diameter portion is exposed to the water pressure in said chamber. The piston also has a portion with a second diameter at the side remote from the variable volume chamber, said second diameter portion of the piston being received in a bore of the body of the emitter that is connected to the water duct so that said second diameter portion is exposed to the water pressure in the water duct.

As is preferred the second diameter is smaller than the first diameter.

Preferably a transition between the cylinder wall having said first diameter and the wall portion of the body having said second diameter is embodied as a shoulder against which the piston is pressed in its rest position.

In an embodiment the inlet valve of the water emitter comprises an inlet valve body with a bore in which the movable valve member is reciprocable, the movable valve member sealingly engaging an inner surface of the bore and delimiting in said bore an underpressure space and an atmospheric pressure space, the inlet valve body having a passage connecting the atmospheric pressure space to the atmosphere and a passage connecting the underpressure space with the variable volume chamber.

In a variant thereof the movable valve member comprises a tubular main body portion and an annular flange surrounding said main body portion.

It is envisaged that the water supplied by the network may be clean water, or that the water has been provided with one or more additives, e.g. nutrients, e.g. flower grow enhancing additives, etc. It is envisaged that a network with water ducts may have a multitude of water emitters, possibly more than 100 water emitters, e.g. when used in a commercial horticultural environament.

In an embodiment it is envisaged that the system, in addition to the water emitters, may include one or more additional pumps, preferably multiple emitters being paired with an additional pump or even said additional pump being integrated with a water emitter. The additional pumps are, as is envisaged, responsive to the controlled water pressure variation in the network and operated by said water pressure variation.

Each additional pump is adapted to emit - intermittently and possibly in synchronicity with the one or more water emitters - portions of a fluid, preferably a fluid other than the fluid in the network, e.g. air or another gas, or a non-water liquid, e.g. a nutrient liquid, a foaming agent, a (organic) pesticide, etc.

Each additional pump comprises:

- a variable volume fluid chamber having a member that is exposed to the water pressure in the network of one or more water ducts,

- a variable volume fluid chamber restoring means,

which variable volume fluid chamber has:

- a fluid inlet for introduction of fluid into the variable volume fluid chamber, said inlet not being in communication with the network of one or more water ducts, wherein preferably a non-return inlet valve is associated with said inlet,

- an outlet for passing said fluid from the variable volume fluid chamber, wherein preferably an non-return outlet valve is associated with said outlet,

wherein the variable volume fluid chamber has a volume that is reduced upon increased pressurization of water in the water duct, and that is increased, at least aided by said variable volume chamber restoring means, when the increased pressurization of water in the water duct is removed.

In an embodiment the effective volume of the additional pump may lie in the range between 0.5 ml and 200 ml. In an embodiment an additional pump as described above is paired with a water emitter, possibly the additional pump and the water emitter being integrated so as to have a single connection with the water duct.

In an embodiment the system comprises a flow combination member connected to both the outlet of the water emitter and to the outlet of the additional pump, the combination member combining the emitted flows, e.g. mixing the emitted flows.

In an embodiment, a reservoir for a liquid is associated with one or more additional pumps, each additional pump in operation being supplied from the reservoir with a portion of the liquid, said portion thereafter being dispensed by said additional pump. If a flow combination member is present, the liquid supplied thereto by the additional pump can be combined, e.g. mixed, with the water. The liquid can e.g. be a nutrient solution. The liquid is e.g. mixed "in situ" with the water at the moment that the water is dispensed by the water emitter, which allows e.g. to select one or more regions in the network where the water is mixed with a liquid provided by the additional pump(s), wherein in one or more other regions of the network no liquid is mixed with the water, or another liquid is mixed with the water.

In a possible embodiment the additional pump is an air pump.

In an embodiment the system is then adapted to supply a (small) volume of atmospheric air to the root zone or proximate to the root zone, independent from the portion of water supplied by the water emitter. For example an air discharge tube is connected to the air pump to bring the air in or near the root zone, e.g. in a plant container.

In another embodiment it is envisaged that the atmospheric air supplied by the air pump may be combined with the portion of water, e.g. so as to cause an aeration of the water such that aerated water is provided. The additional pump may be configured to operate at the same time as the water emitter, so that the flow of fluid from the additional pump is substantially simultaneous with the flow of water from the emitter. This e.g. is favoured for an embodiment wherein the flows are to be combined, e.g. mixed.

In another embodiment the additional pumps may be embodied to operate at a lower pressure in the water duct than the water emitter, such that first the one or more additional pumps start operating, followed by the water emitters. In another embodiment the one or more additional pumps may be embodied to operate a higher pressure in the water duct than the water emitter, such that the water emitters start operating first, followed by the water emitters. In the last mentioned version it is also possible to control the water supply device such that if no operation of the one or more additional pumps is desired, the water pressure is kept below the operational water pressure that set the additional pumps into action.

As explained above aeration of water may be caused by provision of one or more additional air pumps responsive to the water pressure in the network. In an alternative embodiment for providing aerated water, no additional air pumps are present in the system, the aeration of the water being caused by an eductor member that entrains air with a flow of water emerging from the emitter, e.g. as disclosed in US3660933.

The present invention also relates to an intermittent water irrigation system according to claim 12. This system is preferably provided with a water inlet valve as disclosed above, but other water inlet valves may also be envisaged, e.g. an electrically or electromagnetically actuated water inlet valve. Preferred features of the invention are disclosed in the subclaims as well as with reference to one or more exemplary embodiments discussed with reference to the drawings.

The skilled person will appreciate that a feature, e.g. a preferred feature, disclosed herein with reference to one or more exemplary embodiments may also be combined with one or more of the other exemplary embodiments and with the system of claim 1 and/or of claim 12.

The present invention also relates to a method for irrigation, wherein use is made of a system according to the invention.

The present invention also relates to a method for growing a crop, flowers, plants, and other biological organisms, e.g. indoors or outdoors, wherein use is made of a system according to the invention. It is also envisaged that an emitter may be mounted in or on a plant container or a basin receiving plant containers, e.g. as used in horticultural greenhouses, e.g. as a replacement for drip irrigation.

In the drawings:

Fig. 1 shows an example of a water irrigation system with water emitters according to the invention,

Fig. 2A shows in cross-section the water-emitter of figure 1 ,

Fig. 2B shows in a partially cut-away view the water emitter of fig. 2A.

Fig. 3A shows the system of figure 1 in a different operating phase,

Fig. 3B shows on a larger scale the water emitter of fig. 3A,

Fig. 4A shows the system of figure 1 in a different operating phase,

Fig. 4B shows on a larger scale the water emitter of fig. 4A,

Fig. 5A shows the system of figure 1 in a different operating phase,

Fig. 5B shows on a larger scale the water emitter of fig. 4A,

Fig. 6A shows in a partially cut-away view a second example of a water emitter of a water irrigation system according to the invention,

Fig. 6B shows the water emitter of fig. 6A in cross-section,

Fig. 7 schematically shows the presence of an additional pump in a water irrigation system according to the invention,

Fig. 8 schematically shows the arrangement of figure 7, wherein the water discharged from the water emitter is combined with the discharge of the additional pump, Fig. 9 schematically shows the arrangement of figure 7, wherein the additional pump is connected to a reservoir,

Fig. 10 shows in cross-section an alternative water emitter of a water irrigation system according to the invention, in this example integrated with an additional pump.

A first example of an irrigation system with water emitters according to the invention will now be explained with reference to figures 1-5.

The system comprises a water supply device that receives water from a water source 1 , for example - as in this embodiment - the water mains providing water at a constant pressure. The water source may be any suitable water source, e.g. of tank, a reservoir, a pond, lake, canal or other body of water, a water well, etc. The source may provide water at a substantially constant pressure, e.g. as in a water mains, or the water supply may include a pump to pressurize the water.

In this example the water supply device comprises a main inlet valve 2, e.g. electronically controlled by an electronic irrigation control unit, e.g. including a programmable computer, (not shown) that governs the entry of water from the source 1. As is preferred the valve 2 is operable to either open or close the connection to the source 1. As is preferred, the valve 2 is opened periodically.

The water supply device here further comprises an accumulator 3, here with an expandable bellows in a gas filled accumulator tank, allowing to store a volume of pressurized water.

The water supply device here further comprises a water pressure release member 4, here embodied as a piston-cylinder member 4, allowing to release or reduce the water pressure on command, as will be explained in more detail below.

The system comprises a network of one or more water ducts 10, 10a, b, c, that are connected to the water supply device. The water ducts may be embodied as hoses, (metal) tubes, or otherwise.

In general the water supply device is adapted for periodic variation of the water pressure in the one or more water ducts of the network that are connected to the water supply device. As can be seen, the water duct 10 has, here via branch ducts 10a, b, c, a plurality of water emitters 20. Each water emitter 20 is adapted to emit intermittently portions of water. As is preferred each emitter is embodied here to such that the emitted water is received by an area adjacent to the emitter, but in another embodiment a further water guiding member, e.g. a dripline, is connected to the emitter. By way of example it is shown that a water emitter 20 is provided with a hose fitting 21 for a hose type water duct. Clearly another connector may also be provided, e.g. screw connection, a bayonet connection or other quick-connect coupling. If desired the connection can be permanent. The emitter 20 includes a variable volume chamber 30 and associated variable volume chamber restoring means.

In this first example the variable volume chamber 30 is delimited by a cylinder 31 and a piston 32 that is reciprocable in the cylinder 31. Preferably the cylinder 31 and piston 32 are plastic components.

Suitable sealing means are provided between the piston and the cylinder. Here the piston 32 is provided with one or more circumferential sealing members, here O-rings, that slide along the inner wall of the cylinder 31.

As is preferred one sealing member 33a seals at the side of the chamber 30, whereas an axially spaced sealing member 33b seals at the side of the water duct 2. As is preferred a zone between said pair of sealing members 33a, b is embodied as an annular air space 38, that is in communication with the atmosphere, as is preferred via one or more passages 39 in the cylinder 31.

In another embodiment, of which an example will be explained with reference to figures 6A and 6B, the emitter 20 has one or more rolling diaphragm seals between the piston 32 and the cylinder 31.

Clearly other designs of the chamber are also possible, e.g. the chamber 30 being embodied as a bellows.

A restoring spring 35 is provided here to act as variable volume chamber restoring means. The spring 35 urges the variable volume chamber 30 to its maximum volume, here by biasing the piston 32 to a limit position. Here the spring 35 is arranged inside the chamber 30. As is practical the spring 35 here is a coil spring. The spring 35 could also be arranged outside of the chamber 30. The spring could also be incorporate in the piston, e.g. as a spring part of the piston, e.g. the piston and spring being moulded from plastic.

The variable volume chamber 30 has a water outlet 40 for passing water from the variable volume chamber 30. An outlet valve 45 is associated with said outlet 40. As is preferred the outlet valve 45 is a self closing valve, e.g. a check valve. A duckbill valve is shown in this example. As is preferred the outlet valve 45 automatically opens upon suitable pressurization of water in the chamber 30, so that said water flows through said valve 45. As is preferred the valve 45 closes automatically upon completion of discharge of water from the chamber 30 so as to avoid air or water being sucked into the chamber 30.

In this example, the water is directly discharged from the outlet valve 45, so that no further portion of the emitter is in contact with the dispensed water other than the valve 45, e.g. the water landing directly on a patch of soil to be irrigated. However, other embodiments are also possible.

For example the emitter 20 can be connected at the side of the outlet valve to a drip line, from which water is allowed to drip as is known in the art.

The chamber 30 also includes a water inlet 50 that is in communication with the water duct 2. An inlet valve 60 is associated with said water inlet 50. The inlet valve 60 governs the entry of water from the water duct 2 into the chamber 30.

In general the variable volume chamber 30 has a volume that is reduced upon increased pressurization of water in the water duct 2. The volume of chamber 30 is increased, at least aided by the variable volume chamber restoring means (here spring 35), when the increased pressurization of the water in the water duct 2 is removed.

In general the inlet valve 60 is configured to close the water inlet 50 to the chamber 30 upon increase of pressurization of the water in the water duct 2 so that water is then passed from the chamber 30 via the water outlet 40. The inlet valve 60 is also configured to open the water inlet 50 upon removal of the increased pressurization of the water in the water duct 2 so as to allow for the flow of water from the water duct 2 into the variable volume chamber 30.

As is practically preferred the inlet valve 60 is arranged in the piston 32 of the variable volume chamber so as to move with the piston 32. The inlet valve 60 is an underpressure actuated inlet valve 60. The piston 32, here at its side facing the water duct 2, is embodied as or provided with an inlet valve body 61 of said valve.

The valve 60 comprises a movable valve member 65 which in this embodiment has a first flexible diaphragm 65b that is at its outer contour connected to the valve body 61 (which is integral with the piston 32 in this example).

The valve member 65 is further integral with a second flexible diaphragm 65c, that extends as an annular diaphragm from a tubular central portion of the valve member 65 to its outer contour which is connected to the piston 32.

A space 64 is present between the diaphragms 65b, 65c, which space 64 is in

communication with the atmosphere and separated from the chamber 30. Here the piston 32 is provided with one or more passages 32b leading from said space 64 to annular air space 38 between the piston and the cylinder.

As is preferred the diameter of the diaphragm 65b is greater than of the diaphragm 65c.

The valve member 65 has a sealing portion, here at the top of a raised stub shaped central portion, that is adapted to cooperate with an associated seat 66 for the movable valve member 65. Here the seat 66 is integral with the piston 32 of the chamber 30. The seat 66 faces the water duct 2 so that increased pressurization of water in the water duct 2 presses the sealing portion of the movable valve member 65 onto the seat 66. Figures 1 , 2A, B show the inlet valve 60 in closed position. The first diaphragm 65b defines an underpressure space 63, here between the interior surface 65a1 of the diaphragm 65b and an end cap of the piston wherein the seat 66 is formed. This space 63 is in open communication with the chamber 30 via one or more passages 63a in a central tubular portion of the valve member, here in the raised stub of the valve member 65. The interior surface 65a1 of the diaphragm 65b is thus exposed to the pressure in the chamber 30. The opposed, exterior surface 65a2 of the diaphragm 65b is exposed to the atmospheric pressure in space 64. Also the diaphragm 65c has one surface exposed to the atmospheric pressure in space 64 and one opposed surface exposed to the pressure in chamber 30. It is noted that these surfaces are best seen in figure 5B. As is preferred the diaphragm 65b itself is embodied to provide a restoring force that urges the valve member 65 towards its seat 66. The use of the diaphragm 65b may thus obviate the need for a separate inlet valve restoring spring. If desired such a spring may nevertheless be provided.

The inlet valve 60 is configured such that - when an underpressure is created in the variable volume chamber 30 as a result of increase of the volume of the chamber 30 due to removal of the increased pressurization of the water in the water duct 2 - the movable valve member 65 is caused to move from its seat, thereby opening the inlet valve 60 and allowing flow of water (see F) from the water duct 2 into the variable volume chamber 3. This is illustrated in figures 5A, B, wherein the piston moves in direction of arrow P to increase the volume of the chamber 30. A more detailed explanation will be given below.

In this example a tubular portion 25 of the body is concentrically arranged within the cylinder 31 and integral with the wall 21 , said tubular body portion housing the outlet valve 45. Also the tubular portion 25 here, as is preferred, serves to support an end of the spring 35.

As is preferred the piston 32 has a stepped diameter structure, having a portion with a first diameter at the side delimiting the variable volume chamber 30, which first diameter portion is reciprocable in a corresponding diameter portion of a bore of the cylinder so that the first diameter portion is exposed to the water pressure in said chamber 30. The piston 32 also has a portion with a second diameter at the side remote from the variable volume chamber

30, said second diameter portion of the piston 32 being received in a bore of the body of the emitter that is connected to the water duct so that said second diameter portion is exposed to the water pressure in the water duct 2.

As is preferred the second diameter is smaller than the first diameter. Preferably the transition between the cylinder wall having said first diameter and the wall portion of the body having said second diameter is embodied as a shoulder against which the piston is pressed by the spring 35 in its rest position.

The piston 32 here includes a cup shaped portion with at the side facing the chamber a radially extending rim in which a sealing member is retained that cooperates with the cylinder

31. The spring extends into the cup shaped portion so as to support said end of the spring and so as to allow for a relatively large length of the spring 35.

The bottom of the cup shape portion has a central passage above which the inlet valve is mounted. The operation of the system and the emitters 20 thereof will now be explained with reference to figures 1 - 5 wherein a water dispensing cycle is illustrated.

In figure 1 , 2A, b the system is shown in a situation prior to the start of a water dispensing cycle. It is here assumed that the chamber 30 is filled with water due to earlier operation cycle of the system. In this at rest position the one or more of the diaphragms ensure that the inlet valve 60 is closed. So no water can flow back from the chamber 30 into the water duct 2 and vice versa.

The accumulator 3 is only partly filled with water compared to its maximum water capacity. The valve 2 is closed. The pressure release cylinder 4 is in its minimum volume position, so that the effective water volume in said cylinder 4 is minimal.

Then the valve 2 is opened, preferably by said control unit. This leads to a pressurization or raise of pressure of the water in the water ducts 10a, b, c. The pressurized water in the ducts 10 a-c presses against the piston 32 of each emitter 20 which then moves (against the spring 35 and with its inlet valve 60 closed) towards the fully compressed position of the chamber 30. This situation is shown in figures 3A, B.

This piston motion causes the dispensing, in this single cycle, of a metered portion of water from the chamber 30. The metered portion here basically corresponds to the volume of water that is expelled from the chamber 30 without new water flowing into said chamber 30.

The water pressure of water duct 2 in this phase of the cycle keeps acting on the movable valve member 65 and forces it against it seat 66, so that the inlet valve 60 remains closed during the expulsion of water from the chamber 30 via the outlet valve 45. As mentioned the outlet valve 45 automatically opens due to pressure of the water in the chamber 30. Once the piston 32 reaches its limit position the dispensing of water stops as the inlet valve 60 remains closed. So the dispensing of the metered portion of water is then completed. In the exemplary system, the act of opening the valve 2 also causes the filling of the accumulator 3 with water. The cylinder 4 is held during this dispensing phase in its minimum volume position.

Now the valve 2 is closed. By operating the cylinder 4 and moving the piston thereof to a maximum volume position the water pressure in the water ducts 10a, b, c is reduced. This reduction of the water pressure on command leads to the next phase of the cycle wherein the inlet valve 60 opens. This is accompanied by a motion of the piston 32 of the chamber 30 from its position shown in figure 4A, which motion is illustrated in figures 5A, B, to the position as shown in figures 2A, B. This motion of the piston 32 is caused in this example by the spring 35.

This motion of the piston 32 causes the effective volume of the chamber 30 to increase. As the outlet valve 45 is automatically closed now, no air can be sucked into the chamber via said valve 45. Therefore an underpressure occurs in the chamber 30. In general the pressure difference between the underpressure in chamber 30, to which corresponding faces of the diaphragms 65a, 65b are exposed, and the atmospheric pressure to which opposed faces of said diaphragms 65a, 65b are exposed, is such that the inlet valve 60 opens. An effective opening force on the valve member 65 is thus created by the underpressure in the chamber 30 which causes the valve member 65 to move from its seat 66 as shown in figure 5A, B. Now the chamber 30 is in communication with the duct 10a. The water will now flow into the chamber 30 (as indicated with arrows F) due to the sucking action of the expanding chamber 30, possibly aided by residual water pressure.

In this phase the accumulator 3 mainly serves to make up for any difference between the volume of water that has effectively been dispensed and the volume displaced by the piston 32 in the return stroke. It will be appreciated that the stepped structure of the piston causes this difference. In absence of such a need for make up of a volume difference, the accumulator, or any equivalent structure, may be dispensed with. The member 4 is brought back into its minimum volume position.

Finally the position of figures 2A,B is reached again. A dispensing of a further metered dose of water may now be effected by repeating the cycle. A second example of a container with water emitter 20' according to the invention will now be explained with reference to figure 6A,B.

In figures 6A and 6B parts corresponding to parts identical or similar to parts of the first exemplary embodiment have been denoted with the same reference numeral.

In the embodiment shown here the O-ring seals 33a, 33b between the cylinder 31 and the piston 32 are each replaced by a rolling diaphragm seal. Such a seal may comprise an inner radial section of circular configuration attached to the piston, an outer annular skirt attached to the cylinder, and a rolling wall between said inner radial section and said outer annular skirt.

It is envisaged as an optional feature that the size of the dose to the dispensed may be adjusted by a setting of a setting member of the emitter. For example one can envisage that the top wall 20b can be set at different axial positions, e.g. by having screw thread of axially spaced retaining positions of the top wall with respect to the cylinder 31 , or by some other setting member.

On can also envisage an embodiment wherein the portion volume setting member provides for a locking or zero-setting of the emitter 20, so that no water is expelled at all if the water in the water duct 2 is pressurized.

In an embodiment the water emitter is embodied to dispense the water as a spray by atomizing or nebulising the water, e.g. using a swirl chamber to obtain a fine spray.

With reference to figures 7 - 9 some embodiments will be illustrated wherein an additional pump is present in the water irrigation system.

In figure 7 a water duct 10 is shown to which is connected a water emitter 20, e.g. embodied as explained with reference to the figures 1 - 6.

In addition to the water emitter 20, here paired with said emitter 20, an additional pump 100 is present, the pump 100 being responsive to the controlled water pressure variation in the network with duct 10 and being operated by said water pressure variation. The additional pump 100 is adapted to emit - intermittently and possibly in synchronicity with the one or more water emitters - portions of a fluid, preferably a fluid other than the fluid in the network, e.g. air or another gas, or a non-water liquid, e.g. a nutrient liquid, a foaming agent, a (organic) pesticide, etc. The additional pump 100 here is shown as a piston pump with a return spring biasing the piston to its starting position. The pump 100 here has a cylinder 101 and a piston 102 that is reciprocable in said cylinder 101. The piston 102 delimits a water chamber 103 that is via a connector 104 of the pump 100 in communication with the water duct 10, so that one side of the piston 102 is exposed to the water pressure in the water duct 10. On the other side, the piston delimits a variable volume fluid chamber 105 that serves to pump a fluid. In order to urge the piston 102 to a start position thereof, a variable volume fluid chamber restoring means, here embodied as a restoring spring 106 is provided.

In order to shield the spring from the fluid, here a bellows 107 is provided to delimit the periphery of the chamber 105. It will be appreciated that the spring 106 could be absent in case the bellows provide a restoring force for the piston.

The pump 100 has a fluid inlet 108 for introduction of fluid into the variable volume fluid chamber 105. This inlet 108 is not in communication with the network of one or more water ducts 10. As is preferred a non-return inlet valve 109 is associated with the inlet 108.

The pump 100 has an outlet 110 for passing fluid from the variable volume fluid chamber 105. As is preferred a non-return outlet valve 1 11 is associated with the outlet 110.

It will be appreciated that the variable volume fluid chamber 105 has a volume that is reduced upon increased pressurization of water in the water duct 10, so that a portion of fluid is emitted from the outlet 1 10. The volume of chamber 105 is increased, at least aided by said variable volume chamber restoring means 106, when the increased pressurization of water in the water duct 10 is removed. In an embodiment the effective volume of the additional pump may lie in the range between 0.5 and 200 ml.

The pump 100 may be an air pump, e.g. with an air duct connected to the outlet 1 11 that leads to a root zone so that a portion of air is supplied to the root zone, enhancing growth.

In figure 8 it is illustrated that the system comprises a flow combination member 120 that is connected to both the outlet of the water emitter 20 and to the outlet 1 10 of the additional pump 110, the combination member 120 combining the emitted flows, e.g. mixing the emitted flows. As explained this may be used to cause an aeration of water emitted from the emitter 20, the additional air in the water e.g. enhancing growth.

In figure 9 it is illustrated that a reservoir 130 for a liquid is associated with one or more additional pumps 100, each additional pump in operation being supplied from the reservoir 130 with a portion of the liquid, said portion thereafter being dispensed by said additional pump 100. If a flow combination member is present, as in the embodiment shown here, the liquid supplied thereto by the additional pump 100 can be combined, e.g. mixed, with the water from emitter 20. The liquid can e.g. be a nutrient solution. The liquid is e.g. mixed "in situ" with the water at the moment that the water is dispensed by the water emitter, which allows e.g. to select one or more regions in the network where the water is mixed with a liquid provided by the additional pump(s), wherein in one or more other regions of the network no liquid is mixed with the water, or another liquid is mixed with the water.

The reservoir 130 may have any suitable embodiment, e.g. an open topped reservoir, a bottle, a pouch, etc. The reservoir 130 may also be formed by a second network of ducts that is independent from the network of ducts with the water emitters, which second network carries a fluid different than the water in the network of the water emitters. This e.g. allows to fill the second network with a selected fluid, e.g. a nutrient solution, each pump taking from the network a predetermined portion during an operating cycle of the network with the water emitters.

In an embodiment without combination member 120 in an irrigation system having one or more additional air pumps 100 one can envisage that a (small) volume of atmospheric air is supplied to the root zone or proximate to the root zone, independent from the portion of water supplied by the water emitter. For example an air discharge tube is connected to the air pump to bring the air in or near the root zone, e.g. in a plant container. The additional pump may be configured to operate at the same time as the water emitter, so that the flow of fluid from the additional pump is substantially simultaneous with the flow of water from the emitter. This e.g. is favoured for an embodiment wherein the flows are to be combined, e.g. mixed. This can be achieved e.g. in the embodiments of figures 7-9 by tuning the pump and the emitter so that they effectively operate at substantially the same water pressure in the network.

In another embodiment the additional pumps may be embodied to operate at a lower pressure in the water duct than the water emitter, e.g. by having a weak spring 106, such that first the one or more additional pumps start operating, followed by the water emitters 20. In another embodiment the one or more additional pumps may be embodied to operate a higher pressure in the water duct than the water emitter, e.g. by having a rather stiff spring 106, such that the water emitters start operating first, followed by the pumps 100.

With reference to figure 10 now first an alternative embodiment of the inlet valve of a water emitter will be discussed. The embodiment of figure 10 also illustrates an example of the complete integration of a water emitter and an additional pump which will also be discussed below. The water emitter 200 includes a variable volume chamber 230 and associated variable volume product chamber restoring means.

In this example the variable volume product chamber 230 is delimited by a cylinder 231 and a piston 232 that is reciprocable in the cylinder 231. Clearly other designs are also possible, e.g. the chamber 230 being embodied as a bellows. Preferably the cylinder 231 and piston 232 are plastic components.

A restoring spring 235 is provided here to act as variable volume chamber restoring means. The spring 235 urges the variable volume chamber 230 to its maximum volume, here by biasing the piston 232 to a limit position. Here the spring 235 is arranged inside the chamber 230. As is practical the spring 235 here is a coil spring. The spring 235 could also be arranged outside of the chamber 230. The spring could also be incorporate in the piston, e.g. as a spring part of the piston, e.g. the piston and spring being moulded from plastic. The variable volume chamber 230 has a water outlet 240. An outlet valve 245 is associated with said outlet 240. As is preferred the outlet valve 45 is a self closing valve, e.g. a check valve. A duckbill valve is shown in this example. As is preferred the outlet valve 245 automatically opens upon suitable pressurization of water in the chamber 230, so that water flows through said valve 245. As is preferred the valve 245 closes automatically upon completion of discharge of water from the chamber 230 so as to avoid air being sucked into the chamber 230.

In this example, as in a practical embodiment of the inventive water emitter, the water is directly discharged from the outlet valve 45, so that no further portion of the device is in contact with the dispensed water other than the valve 45. However, other embodiments are also possible. For example the emitter 200 can be embodied to dispense the water as a foam, e.g. including one or foam generating members, preferably downstream of the outlet valve of chamber 230. A foaming agent could be added to the water to cause the foaming, possibly an additional pump providing the foaming agent in situ at the moment of dispensing of the portion of water.

The emitter 200 can also include, or be connected to, a dispensing tube or other dispensing fitment. The chamber 230 also includes a water inlet 250 that is in communication with the water duct 10. An inlet valve 260 is associated with said water inlet 250. The inlet valve 260 governs the entry of water from the water duct 10 into the chamber 230. In general the chamber 230 has a volume that is reduced upon increased pressurization of water in the water duct 10. The volume of chamber 230 is increased, at least aided by the variable volume product chamber restoring means (here spring 235), when the increased pressurization of the water in the water duct 10 is removed.

In general the inlet valve 260 is configured to close the inlet 250 to the chamber 230 upon increase of pressurization of the water in the duct 10 so that water is then passed from the chamber 230 via the outlet 240. The inlet valve 260 is also configured to open the water inlet 250 upon removal of the increased pressurization of the water in the duct 10 so as to allow for the flow of water from the duct 10 into the variable volume product chamber 230.

As is practically preferred the inlet valve 260 is arranged in the piston 232 of the variable volume chamber so as to move with the piston 232.

The inlet valve 260 is an underpressure actuated inlet valve 260. The valve 260 comprises a movable valve member 265 and an associated seat 266 for the movable valve member 265. Here the seat 266 is integral with the piston 232 of the chamber 230. The seat 266 faces the water duct 10 so that increased pressurization of water in the duct 10 presses the movable valve member 265 onto the seat 266. Figure 10 shows the inlet valve 260 in opened position.

The movable valve member has a first or external surface 267 in communication with the atmosphere, here via telescoping duct 267a, so as to be exposed to atmospheric pressure and has a second or internal surface 268 in communication with the variable volume chamber 230 so as to be exposed to pressure in said variable volume chamber.

The inlet valve 260 is configured such that - when an underpressure is created in the variable volume chamber 230 as a result of increase of the volume of the chamber 230 due to removal of the increased pressurization of the water in duct 10 - the movable valve member 265 is caused to move from its seat, thereby opening the inlet valve 260 and allowing flow of water into the variable volume chamber 230. In the example shown in figure 10 the inlet valve 260 comprises an inlet valve body that is integral, here monolithic, with the piston 232, preferably made of plastic material. The body has a bore in which the movable valve member 265 is reciprocable. The movable valve member 265 sealingly engages an inner surface of the bore and delimits in the bore an underpressure space 263 and an atmospheric pressure space 264. In this example the movable valve member 265 comprises a tubular main body portion and an annular flange surrounding said main body portion. The periphery of the annular flange sealingly engages the inner surface of the bore, here a sealing ring being provided.

As is preferred the inlet valve 260 comprises an inlet valve restoring means that provides a restoring force urging the movable inlet valve member 265 towards its seat 266. Here a spring 269 is provided as restoring means, the spring 269 being arranged between the valve body and the movable valve member 265.

The water emitter 200 also illustrates the integration of an additional pump 100 with the emitter. As can be seen the piston 232 now also forms part of the pump 100 as it delimits a variable volume fluid chamber 105, separate from the chamber 230 yet in the same housing, here with the provision of fluid inlet 108, fluid outlet 109, and - as is preferred - with associated inlet valve 109 and outlet 1 11. The pump 100 can e.g. be an air pump as explained above, or a liquid pump if so desired. It will be appreciated that a combination member arranged to combine the water with said fluid could also be integrated into the emitter/additional pump unit.

It will be appreciated that the commanded variation of water pressure in the water ducts of the network can also be achieved with a water supply device in different embodiments, e.g. with a pump, e.g. a reversible pump.

It will be appreciated that the member 4 that is described here as a piston-cylinder device may also have a different embodiment. For example the member 4 could be a release valve, allowing some water to flow out of the network, e.g. into a reservoir, to reduce the water pressure. If desired the network can be provided with multiple water pressure release devices distributed throughout the network, e.g. to enhance the reduction of water pressure on command in the network.

Claims

C L A I M S

1. An intermittent water irrigation system, comprising: a water supply device (2,3,4) and a network of one or more water ducts (10, 10a, 10b, 10c) connected or to be connected to said water supply device, wherein the water supply device is adapted for controlled variation of water pressure in the one or more water ducts of the network, wherein at least one water duct has a plurality of water emitters (20; 200), each water emitter being adapted to emit intermittently portions of water, wherein each water emitter (20; 200) comprises:

- a variable volume chamber (30; 230) and associated variable volume chamber restoring means (35; 235), which variable volume chamber has:

- a water outlet (40; 240) for passing water from the variable volume chamber, wherein an outlet valve (45; 245) is associated with said outlet,

- a water inlet (50; 250) in communication with the water duct, wherein an inlet valve (60; 260) is associated with said water inlet, wherein the variable volume chamber (30; 230) has a volume that is reduced upon increased pressurization of water in the water duct, and that is increased, at least aided by said variable volume chamber restoring means (35; 235), when the increased pressurization of water in the water duct is removed, wherein the inlet valve (60; 260) is configured to close the water inlet upon increase of pressurization of the water in the water duct so that water is then passed from the chamber via the water outlet, and wherein the inlet valve (60; 260) is configured to open the water inlet upon removal of said increased pressurization so as to allow for the flow of water from the water duct into the variable volume chamber, and wherein the inlet valve has a movable closure member (65; 265) and an associated seat (66; 266) for said closure member, and wherein the inlet valve (60; 260) is a underpressure actuated inlet valve, the movable closure member having a first surface (65a2; 267) in communication with the atmosphere so as to be exposed to atmospheric pressure and a second surface (65a1 ; 268) in

communication with the variable volume chamber so as to be exposed to pressure in said variable volume chamber, the inlet valve (60; 260) being configured such that - when a underpressure is created in the variable volume chamber as a result of increase of the volume of said chamber due to removal of the increased pressurization of the water in the water duct - the movable valve member is caused to move from its seat, thereby allowing flow of water from the water duct into the variable volume chamber.

2. System according to claim 1 , wherein the variable volume chamber is delimited by a cylinder (31 ; 231) and a piston (32; 232) that is reciprocable in the cylinder.

3. System according to claim 2, wherein the inlet valve (60; 260) is arranged in the piston.

4. System according to one or more of the preceding claims, wherein a variable chamber restoring spring (35; 235) is provided, e.g. mounted in the variable volume chamber.

5. System according to one or more of the preceding claims, wherein the outlet valve is a self-closing valve (45; 245), preferably a duckbill valve.

6. System according to one or more of the preceding claims, wherein the movable valve body has at least one flexible diaphragm that is fastened at its outer periphery to the piston, a first surface (65a2) of the flexible diaphragm being in communication with the atmosphere and a second surface (65a1) of the diaphragm being in communication with the variable volume chamber (30).

7. System according to one or more of the preceding claims, wherein the emitter has a setting means allowing to set the volume of a water portion to be dispensed, e.g. between multiple distinct maximum volumes of a portion to be dispensed.

8. System according to one or more of the preceding claims, wherein the system, in addition to the water emitters (20; 200), includes one or more additional pumps (100), each additional pump being adapted to emit intermittently portions of a fluid other than water in the network of water ducts, e.g. air or a liquid, wherein each additional pump comprises:

- a variable volume fluid chamber (105) delimited by a movable member (102; 232) that is exposed to the water pressure in the network of one or more water ducts (10);

- variable volume fluid chamber restoring means (106; 235),

- a fluid inlet (108) for introduction of fluid into the variable volume fluid chamber, said inlet not being in communication with the network of one or more water ducts, wherein preferably a non-return inlet valve (109) is associated with said inlet,

- an outlet (110) for passing said fluid from the variable volume fluid chamber (105), wherein preferably an non-return outlet valve (11 1) is associated with said outlet, wherein the variable volume fluid chamber (105) has a volume that is reduced upon increased pressurization of water in the network of water ducts (10), and that is increased, at least aided by said variable volume chamber restoring means, when the increased pressurization of water in the network of water ducts is removed.

9. System according to claim 8, wherein the system comprises a flow combination member (120) connected to both the outlet of the water emitter (20) and to the outlet of the additional pump (100), the combination member combining the emitted flows, e.g. mixing the emitted flows.

10. System according to claim 8 or 9, wherein the additional pump (100) is an air pump, wherein, when present, the flow combination member (120) is adapted to cause aeration of the water, so that aerated water is emitted from the combination member.

1 1. System according to claim 8 or 9, wherein a reservoir (130) for a liquid is associated with said one or more additional pumps (100), each pump (100) in operation being supplied from the reservoir with a portion of the liquid, said portion thereafter being dispensed by said additional pump, wherein, possibly, the liquid in the reservoir is mixed with the water emitted from the water emitter.

12. An intermittent water irrigation system, comprising: a water supply device (2,3,4) and a network of one or more water ducts (10, 10a, 10b, 10c) connected or to be connected to said water supply device, wherein the water supply device is adapted for controlled variation of water pressure in the one or more water ducts of the network, wherein at least one water duct has a plurality of water emitters (20; 200), each water emitter being adapted to emit intermittently portions of water, wherein each water emitter (20; 200) comprises:

- a water inlet (50; 250) in communication with the water duct, wherein an inlet valve (60; 260) is associated with said water inlet, wherein the variable volume chamber (30; 230) has a volume that is reduced upon increased pressurization of water in the water duct, and that is increased, at least aided by said variable volume chamber restoring means (35; 235), when the increased pressurization of water in the water duct is removed, wherein the inlet valve (60; 260) is configured to close the water inlet upon increase of pressurization of the water in the water duct so that water is then passed from the chamber via the water outlet, and wherein the inlet valve (60; 260) is configured to open the water inlet upon removal of said increased pressurization so as to allow for the flow of water from the water duct into the variable volume chamber, and wherein the system, in addition to the water emitters (20; 200), includes one or more additional pumps (100), each additional pump being adapted to emit intermittently portions of a fluid other than the water in the network of water ducts (10, 10a, b, c), e.g. air or a liquid, wherein each additional pump comprises:

- variable volume fluid chamber restoring means (106; 235),

- an outlet (110) for passing said fluid from the variable volume fluid chamber (105), wherein preferably an non-return outlet valve (1 11) is associated with said outlet,

wherein the variable volume fluid chamber (105) has a volume that is reduced upon increased pressurization of water in the network of water ducts (10), and that is increased, at least aided by said variable volume chamber restoring means, when the increased pressurization of water in the network of water ducts is removed.

13. Method for irrigation, wherein use is made of a system according to one or more of the preceding claims.

14. Method for growing a crop, flowers, plants, and other biological organisms, wherein use is made of a system according to one or more of the preceding claims.