Claims:
1. A fluid flow controller (102, 200), comprising:
an inlet chamber (202) adapted to receive a fluid and an outlet chamber (206) adapted to dispense the fluid to a defined area;
a membrane valve (210) adapted to divide the inlet chamber (202) into at least a first chamber unit (212) and a second chamber unit (214);
a fluid sampling unit (226) adapted to collect a sample of the fluid from the outlet chamber (206);
a beam balance (216) having a fluid collection limb (218) and a reference limb (220), wherein the fluid collection limb (218) is configured to move from a first position to a second position upon collecting a designated amount of the fluid sample, and wherein the fluid collection limb (218) is configured to move from the second position to the first position once another designated amount of the fluid sample is dispensed from the fluid collection limb (218);
a magnet (234) operatively coupled to the fluid collection limb (218) such that the magnet (234) moves with the fluid collection limb (218); and
a plunger (236) operatively coupled to the magnet (234) such that the plunger (236) opens a passage between the second chamber unit (214) and the outlet chamber (206) to allow flow of the fluid to the defined area via the outlet chamber (206) when the fluid collection limb (218) is disposed in the first position, and wherein the plunger (236) blocks the passage between the second chamber unit (214) and the outlet chamber (206) when the fluid collection limb (218) is disposed in the second position to stop dispensing the fluid to the defined area.

2. The fluid flow controller (102, 200) as claimed in claim 1, wherein the membrane valve (210) further comprises one or more orifices (222) that allow the fluid to move from the first chamber unit (212) to the second chamber unit (214) to equalize the pressure in the first chamber unit (212) and the second chamber unit (214).

3. The fluid flow controller (102, 200) as claimed in claim 2, further comprising an elastic holding device (244), which is coupled to the membrane valve (210) on one end and a surface of the second chamber unit (214) at another end, and is adapted to push down on the membrane valve (210) to restrict a flow of the fluid from the inlet chamber (202) to the outlet chamber (206).

4. The fluid flow controller (102, 200) as claimed in claim 2, wherein the plunger (236) is configured to open the passage between the second chamber unit (214) and the outlet chamber (206) when the pressure in the second chamber unit (214) decreases, thereby causing the membrane valve (210) to be displaced to allow the fluid to flow from the inlet chamber (202) to the outlet chamber (206).

5. The fluid flow controller (102, 200) as claimed in claim 2, wherein the plunger (236) is configured to block the passage between the second chamber unit (214) and the outlet chamber (206) when the pressure in the second chamber unit (214) increases, thereby causing movement of the fluid from the first chamber unit (212) to the second chamber unit (214) via the orifices (222).

6. The fluid flow controller (102, 200) as claimed in claim 2, wherein the beam balance (216) is disposed on a support (246) at a pivot point (248, 258A, 258B, 258C) that is different from a center of gravity of the beam balance (216).

7. The fluid flow controller (102, 200) as claimed in claim 6, wherein a position of the pivot point (248, 258A, 258B, 258C) on the support (246) is selected such that fluid collection limb (218) moves from the first position to the second position only upon collecting the designated amount of the fluid, and such that the fluid collection limb (218) moves from the second position to the first position only once another designated amount of the fluid sample is dispensed from the fluid collection limb (218).

8. The fluid flow controller (102, 200) as claimed in claim 1, wherein the fluid collection limb (218) comprises a plurality of holes (224) having one or more desired shapes and sizes.

9. The fluid flow controller (102, 200) as claimed in 1, wherein the fluid sampling unit (226) comprises:
a sample feeding line (228) coupled to the outlet chamber (206) on one end and a shower at another end configured to transport the fluid sample from the outlet chamber (206) to the plurality of holes (224) in the fluid collection limb (218) via the shower;
a sample rate control valve (230) configured to control a rate of transport of the fluid sample from the outlet chamber (206) to the to the plurality of holes (224) in the fluid collection limb (218) for adjusting a time taken by the fluid collection limb (218) to collect a designated amount of the fluid sample, wherein the rate of transport of the fluid sample is selected based on a desired rate of dispensing the fluid to the defined area.

10. The fluid flow controller (102, 200) as claimed in claim 1, wherein the fluid flow controller (102, 200) is configured to control fluid flow in a drip irrigation apparatus (100), a humidification system, or a sprinkler.

11. The fluid flow controller (102, 200) as claimed in claim 1, wherein the fluid comprises water.

12. The fluid flow controller (102, 200) as claimed in claim 1, wherein the magnet (234) is operatively coupled to the fluid collection limb (218) of the beam balance (216)via a connecting member (240).

13. The fluid flow controller (102, 200) as claimed in claim 1, wherein at least a portion of the plunger (236) is composed of a magnetic material, wherein the beam balance (216) is composed of acrylic plastic, or a combination thereof.

14. The fluid flow controller (102, 200) as claimed in claim 1, further comprising a water resistant protective case (110) comprising one or more openings (112) for allowing one or more fluids from a surrounding environment to pass through and one or more drain openings (114) for draining excess fluid.

15. A fluid flow controller (102, 200), comprising:
an inlet chamber (202) adapted to receive a fluid and an outlet chamber (206) adapted to dispense the fluid to a defined area;
a first valve (210) adapted to divide the inlet chamber (202) into at least a first chamber unit (212) and a second chamber unit (214);
a fluid sampling unit (226) adapted to collect a sample of the fluid from the outlet chamber (206);
a beam balance (216) disposed on a support (246) at a pivot point (248, 258A, 258B, 258C) that is different from a center of gravity of the beam balance (216) and having a fluid collection limb (218) and a reference limb (220), wherein a position of the pivot point (248, 258A, 258B, 258C) on the support (246) is selected such that fluid collection limb (218) moves from the first position to the second position only upon collecting the designated amount of the fluid, and such that the fluid collection limb (218) moves from the second position to the first position only once another designated amount of the fluid sample is dispensed from the fluid collection limb (218); and
a fluid control mechanism (234, 236) coupled to the fluid collection limb (218) and configured to open a passage between the second chamber unit (214) and the outlet chamber (206) to allow flow of the fluid to the defined area via the outlet chamber (206) when the fluid collection limb (218) is disposed in the first position, and block the passage between the second chamber unit (214) and the outlet chamber (206) when the fluid collection limb (218) is disposed in the second position to stop dispensing of the fluid to the defined area.

16. The fluid flow controller (102, 200) as claimed in claim 15, wherein the fluid control mechanism (234, 236) comprises:
a magnet (234) operatively coupled to the fluid collection limb (218) such that the magnet (234) moves with the fluid collection limb (218); and
a plunger (236) operatively coupled to the magnet (234) such that the plunger (236) is configured to open the passage between the second chamber unit (214) and the outlet chamber (206) when the fluid collection limb (218) is disposed in the first position, and to block the passage between the second chamber unit (214) and the outlet chamber (206) when the fluid collection limb (218) is disposed in the second position.

17. The fluid flow controller (102, 200) as claimed in claim 15, wherein the first valve (210) comprises a membrane valve (210), and wherein the membrane valve (210) comprises one or more orifices (222) that allow the fluid to move from the first chamber unit (212) to the second chamber unit (214) to equalize the pressure in the first chamber unit (212) and the second chamber unit (214).
, Description:
TECHNICAL FIELD

[0001] The present description generally relates to fluid flow controllers. Particularly, the present description relates to fluid flow controllers that employ indirect moisture sensing for use in applications such as drip irrigation.

BACKGROUND

[0002] Agriculture plays a strategic role in overall growth economic development of a country. Typically, an increase in agricultural output increases food security and complements and supports industrial activities by providing raw materials, for example for consumer products such as textiles and beverages, opportunities for exporting surplus output, and social welfare. Modern agricultural practices employ automated implements, good quality seeds, and scientific irrigation for increasing the agricultural output. Particularly, modern irrigation scheduling employs scientific water management strategies to irrigate crops and trees at a suitable time and rate based on soil properties, type of crop, availability of water supply and prevailing climatic conditions. Generally, the time and rate of irrigation is typically determined by sensing a moisture content of the soil by using moisture sensing drip irrigation systems. An effective irrigation schedule helps to maximize profit while minimizing water and energy use.
[0003] Some available moisture sensing drip irrigation controllers sense moisture of the soil directly, for example, by using electronic sensors, and thus require continuous supply of electricity. Thus, in order to irrigate remote farms, several long electric wires and associated pipelines are needed for operation of these conventional drip irrigation systems. Even in home drip irrigation systems that are typically installed on terraces, the wiring is a safety concern and the drip irrigation systems often fail during thunderstorms.
[0004] Certain presently known system attempt to address noted issues with conventional drip irrigation systems. For example, the French Patent number 2428390 discloses an automatic plant watering system that includes a valve chamber with a connection for a water supply line and a second connection for a water delivering line, wherein the chamber supports a bi-stable balance arm with an adjustable balance weight one end and a control device mounted on the other end. This device is a spongy mass, which allows the arm to swing with the balance weight lowered, so as to open the valve inside the chamber, and allow water to flow. As water flows, it also passes through a branch line on the side of the valve to travel through a tube, which discharges into a collector above the spongy mass to saturate it. The weight of the water absorbed tilts the arm back to operate the valve for supplying water to the plants and to the sponge. However, a significant amount of pressure is required in order to operate the valve between an open position and a closed position. Moreover, the balance arm has to overcome the pressure of the valve by accommodating a large amount of water, and thus making the balance arm bulkier.
[0005] U.S. Patent number 5,421,515 discloses an irrigation device, which is automatically activated in correlation with the evapotranspiration needs of the plants. The device comprises an open-top fluid evaporation pan containing irrigating fluids, the fluids being capable of evaporating from the pan, thereby reducing its weight. A fluid conduit attached to a fluid inlet port conducts the fluids to the plants and the pan, while a valve, interposed between the inlet port and the conduit and operatively connected to the pan, controls the conduction of the fluids to the pan and the plants. A counter-force member exerts a force on the pan in a direction opposite to that of the force of gravity. When the pan has been filled with an amount of water determined by the needs of the plants, the valve closes and when sufficient water has evaporated from the pan to leave less than a predetermined amount in it, the valve opens.
[0006] U.S. Patent number 2,946,512 discloses automatic irrigation control apparatus comprising an evaporation pan mounted on one end of a balance having an adjustable weight and arranged to close a pair of contacts when all or a predetermined weight of water has evaporated from the pan. The contacts close a circuit through a solenoid valve disposed in an irrigation supply line controlling one or more sprinkler units. The pan is disposed so as to receive a proportion of water from the sprinkler unit so that when the plants irrigated by the sprinkler unit have received a quantity of water determined by that which is collected in the pan, the contacts open, shutting off the water supply.
[0007] U.S. Patent number 2,766,070 discloses an automatically operable valve for a water sprinkling system, which can be mounted in a position to receive a quantity of the water which is sprayed or sprinkled so that when a predetermined quantity of water has been sprayed and collected by the collecting pan forming part of the control device, the water is automatically cut off.
[0008] U.S. Patent number 2,004,194 discloses a device including a conduit having a control valve, a valve operating shaft for alternately opening and closing the control valve, a swinging weight arm mounted on the shaft, a weight carried by the weight arm, a swinging bucket-arm mounted on the shaft and extending oppositely to the weight arm, a drip-cock for diverting fluid from the conduit into the bucket, and a wick for dissipating fluid from the bucket, a locking element adapted to hold the valve closed against the valve operating shaft, and temperature controlled element for operating the locking element to cause release of the valve. The bucket is also configured to collect the rainwater.
[0009] Conventional drip irrigation systems, thus, typically rely on electricity, have complicated design, are bulky, and/or incur significant cost. In addition, conventional drip irrigation systems may not be effective or sustainable due to unreliable power supply, especially in rural areas.

SUMMARY

[0010] According to an aspect of the disclosure, a fluid flow controller is disclosed. The fluid flow controller includes an inlet chamber adapted to receive a fluid and an outlet chamber adapted to dispense the fluid to a defined area, a membrane valve adapted to divide the inlet chamber into at least a first chamber unit and a second chamber unit, and a fluid sampling unit adapted to collect a sample of the fluid from the outlet chamber. The fluid flow controller further includes a beam balance having a fluid collection limb and a reference limb. The fluid collection limb is configured to move from a first position to a second position upon collecting a designated amount of the fluid sample, and from the second position to the first position once another designated amount of the fluid sample is dispensed from the fluid collection limb. The fluid flow controller also includes a magnet operatively coupled to the fluid collection limb such that the magnet moves with the fluid collection limb. Moreover, the fluid flow controller includes a plunger operatively coupled to the magnet such that the plunger opens a passage between the second chamber unit and the outlet chamber to allow flow of the fluid to the defined area via the outlet chamber when the fluid collection limb is disposed in the first position, and blocks the passage when the fluid collection limb is disposed in the second position to stop dispensing the fluid to the defined area.
[0011] According to an aspect, the membrane valve further comprises an orifice that allows the fluid to move from the first chamber unit to the second chamber unit to equalize the pressure in the first chamber unit and the second chamber unit.
[0012] According to an aspect, the fluid flow controller further comprises an elastic holding device, which is coupled to the membrane valve on one end and a surface of the second chamber unit at another end, and is adapted to push down on the membrane valve to restrict a flow of the fluid from the inlet chamber to the outlet chamber.
[0013] According to an aspect, the plunger is configured to open the passage between the second chamber unit and the outlet chamber when the pressure in the second chamber unit decreases, thereby causing the membrane valve to be displaced to allow the fluid to flow from the inlet chamber to the outlet chamber.
[0014] According to an aspect, the plunger is configured to block the passage between the second chamber unit and the outlet chamber when the pressure in the second chamber unit increases, thereby causing movement of the fluid from the first chamber unit to the second chamber unit via the orifice.
[0015] According to an aspect, the beam balance is disposed on a support at a pivot point that is different from a center of gravity of the beam balance.
[0016] According to an aspect, a position of the pivot point on the support is selected such that fluid collection limb moves from the first position to the second position only upon collecting the designated amount of the fluid, and such that the fluid collection limb moves from the second position to the first position only once another designated amount of the fluid sample is dispensed from the fluid collection limb.
[0017] According to an aspect, the fluid collection limb comprises a plurality of holes having one or more desired shapes and sizes.
[0018] According to an aspect, the fluid sampling unit comprises a sample feeding line coupled to the outlet chamber on one end and a shower at another end configured to transport the fluid sample from the outlet chamber to the plurality of holes in the fluid collection limb via the shower. The fluid sampling unit also comprises a sample rate control valve configured to control a rate of transport of the fluid sample from the outlet chamber to the to the plurality of holes in the fluid collection limb for adjusting a time taken by the fluid collection limb to collect a designated amount of the fluid sample, wherein the rate of transport of the fluid sample is selected based on a desired rate of dispensing the fluid to the defined area.
[0019] According to an aspect, the fluid flow controller is configured to control fluid flow in a drip irrigation apparatus, a humidification system, or a sprinkler.
[0020] According to an aspect, the fluid comprises water.
[0021] According to an aspect, the magnet is operatively coupled to the fluid collection limb of the balance beam via a connecting member.
[0022] According to an aspect, at least a portion of the plunger is composed of a magnetic material, wherein the beam balance is composed of acrylic plastic, or a combination thereof.
[0023] According to an aspect, the fluid flow controller further comprises a water resistant protective case comprising one or more openings for allowing one or more fluids from a surrounding environment to pass through and one or more drain openings for draining excess fluid.
[0024] According to an aspect of the disclosure, a fluid flow controller is disclosed. The fluid flow controller includes an inlet chamber adapted to receive a fluid and an outlet chamber adapted to dispense the fluid to a defined area, a first valve adapted to divide the inlet chamber into at least a first chamber unit and a second chamber unit, and a fluid sampling unit adapted to collect a sample of the fluid from the outlet chamber. The fluid flow controller further includes a beam balance disposed on a support at a pivot point that is different from a center of gravity of the beam balance and having a fluid collection limb and a reference limb. A position of the pivot point on the support is selected such that fluid collection limb moves from the first position to the second position only upon collecting the designated amount of the fluid, and such that the fluid collection limb moves from the second position to the first position only once another designated amount of the fluid sample is dispensed from the fluid collection limb. The fluid flow controller also includes a fluid control mechanism coupled to the fluid collection limb and configured to open a passage between the second chamber unit and the outlet chamber to allow flow of the fluid to the defined area via the outlet chamber when the fluid collection limb is disposed in the first position, and block the passage between the second chamber unit and the outlet chamber when the fluid collection limb is disposed in the second position to stop dispensing of the fluid to the defined area.
[0025] According to an aspect, the fluid control mechanism comprises a magnet operatively coupled to the fluid collection limb such that the magnet moves with the fluid collection limb. The fluid control mechanism also comprises a plunger operatively coupled to the magnet such that the plunger is configured to open the passage between the second chamber unit and the outlet chamber when the fluid collection limb is disposed in the first position, and to block the passage when the fluid collection limb is disposed in the second position.
[0026] According to an aspect, the first valve comprises a membrane valve, wherein the membrane valve comprises an orifice that allows the fluid to move from the first chamber unit to the second chamber unit to equalize the pressure in the first chamber unit and the second chamber unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 illustrates a block diagram of a drip irrigation system with a fluid flow controller, according to one embodiment.
[0028] FIG. 2 illustrates a block diagram of a fluid flow controller in an open position, according to one embodiment.
[0029] FIG. 3 illustrates a block diagram of a fluid flow controller in a closed position, according to one embodiment.

DETAILED DESCRIPTION

[0030] Various embodiments are explained in detail below with reference to the various figures. Embodiments are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
[0031] FIG. 1 shows a block diagram of an embodiment of the drip irrigation system 100. The drip irrigation system 100 includes a fluid flow controller 102 configured to control a rate of irrigation to a desired area. Embodiments of the fluid flow controller 102 may similarly be used in a humidification system, a sprinkler system, or other systems where automatic fluid-sensing capabilities are required. However, for clarity of description, the present specification describes various embodiments of the fluid flow controller 102 with reference to the drip irrigation system 100 and with reference to water as a type of fluid.
[0032] In one embodiment, the drip irrigation system 100 receives water supply from an overhead water tank 104 via a pipe 106. In an alternative embodiment, however, the drip irrigation system 100 may be connected directly to a public/municipal water line via the pipe 106. The pipe 106 includes a mechanism such as a ball valve 108 to open and close water supply to the drip irrigation system 100. According to an aspect of the present disclosure, the fluid-flow controller 102 regulates operation of the ball valve 108 to start or stop the water supply.
[0033] In one embodiment, the fluid flow controller 102 includes a water resistant protective casing 110 to prevent any external elements such as dust and debris from interfering with the operation of the fluid flow controller 102. The protective casing 110, however, includes one or more openings 112 for allowing fluids from a surrounding environment such as rainwater to pass through. The protective casing 110 may also include one or more drain openings 114 for draining any excess fluid. A drip line 116 connected to an outlet (depicted and described as outlet opening 208 with reference to FIGs. 2-3) of the fluid flow controller 102 delivers water to the plants 118. An outlet valve 120 is included the drip line 116. The outlet valve 120 can be opened or closed to enable or disable water supply to the plants 118.
[0034] The drip irrigation system 100 further includes a sample feeding tube 122 connected to the drip line 116 to form a T-junction 124. The sample feeding tube 122 is of a smaller cross-section compared to the drip line 116. As water flows into the T-junction 124, a small quantity of the water also flows through the sample feeding tube 122. Sample water, i.e., water flowing through the sample feeding tube 122, is assumed to be indicative of water flowing through the drip line 116. A sample rate control valve 126 is included in the sample feeding tube 122 to adjust the amount of the sample taken through the sample feeding tube 122. The sample water flowing through the sample feeding tube 122 is further delivered to the fluid flow controller 102 via a planar shower, as will be described in detail with reference to FIGs. 2 and 3.
[0035] FIG. 2 shows a block diagram of an embodiment of the fluid flow controller 200, similar to the fluid flow controller 102 of FIG. 1, at a first position. The first position is herein, for example, corresponds to an open position. The fluid flow controller 200 includes an inlet chamber 202 including a water inlet opening 204, an outlet chamber 206 including a water outlet opening 208, a first valve 210 dividing the inlet chamber 202 into at least a first chamber unit 212 and a second chamber unit 214. The inlet chamber 202 receives water from a source such as the overhead water tank 104 (see FIG. 1) or a water supply pipeline (not shown in the FIG. 2). The outlet chamber 206 dispenses water through the water outlet opening 208 to a defined area to be irrigated. The water outlet opening 208 can be connected to the drip line 116 so that water can be delivered to the defined area such as the location of the plants 118 (see FIG. 1). In one embodiment, the first valve 210 is a membrane valve (hereinafter referred to as membrane valve 210). Further, the membrane valve 210 includes one or more orifices 222 that allow water to move from the first chamber unit 212 to the second chamber unit 214. Such a movement of the water eventually equalizes pressure in the first chamber unit 212 and the second chamber unit 214.
[0036] Further, in one embodiment, the fluid flow controller 200 includes a beam balance 216 having a fluid collection limb 218 and a reference limb 220 that cause the membrane valve 210 to open or close. The fluid collection limb 218 and the reference limb 220 appear as semi-circular sheets attached to each side of the beam balance 216. The entire beam balance 216 with the fluid collection limb 218 and the reference limb 220 is a unitary piece that may be manufactured, for example, from a single acrylic sheet. In one embodiment, the fluid collection limb 218 includes a plurality of holes 224 of a desired shape and size to collect water when the beam balance 216 is in the open position. In certain embodiments, the holes 224 are evenly distributed on the fluid collection limb 218. In other embodiments, however, the holes 224 may be distributed unevenly on the fluid collection limb 218. In one exemplary implementation, each of the holes 224 has a diameter of about 3 millimetres for collecting water.
[0037] In certain embodiments, the fluid flow controller 200 further includes a fluid sampling unit 226 for collecting a water sample from the outlet chamber 206. The fluid sampling unit 226 includes a sample feeding line 228 and a sample rate control valve 230. The sample feeding line 228 is coupled to the outlet chamber 206 on one end, and a planar shower 232 at the other end. The sample feeding line 228 carries water sample from the outlet chamber 206 to the plurality of holes 224 in the fluid collection limb 218 via the planar shower 232. The planar shower 232 disperses water in a substantially planar flow that has a width that is substantially similar or is slightly more than the width of the fluid collection limb 218. Furthermore, the planar shower 232 may have one or more rows (e.g., two to four) of holes to generate a water shower that is substantially planar. The sample rate control valve 230 controls a rate of transport of water from the outlet chamber 206 to the plurality of holes 224 in the fluid collection limb 218 via the planar shower 232. Specifically, the sample rate control valve 230 allows a user to adjust the time taken by the fluid collection limb 218 to collect and transport a designated amount of water from the outlet chamber 206 based on a desired rate of water flow to the plants 118.
[0038] Additionally, in one embodiment, the fluid flow controller 200 includes a fluid control mechanism comprising a lightweight permanent magnet such as an O-magnet 234, and a plunger 236 disposed in a plunger housing 238 attached to the outlet chamber 206. The O-magnet 234 is coupled to the fluid collection limb 218 via a connecting member 240 such that the O-magnet 234 moves with the fluid collection limb 218. Additionally, the plunger 236 is magnetically coupled to the O-magnet 234. The plunger housing 238 is surrounded by the O-magnet 234. Therefore, there is no contact between the O-magnet 234 and the plunger 236, as well as very minimal contact between the plunger 236 and the housing 238, thereby leading to a friction-less coupling. The plunger 236 can be made of a magnetic material or coated with a soft magnetic material so that it is magnetically attracted to the O-magnet 234 such that a movement of the O-magnet 234 leads to a movement of the plunger 236 in the same direction.
[0039] In one embodiment, the fluid flow controller 200 further includes a first elastic holding device such as a first spring 242 to hold the plunger 236 in a designated place when the O-magnet 234 is at the top of the housing 238 or, in other words, when the fluid flow controller 200 is in open position. The fluid flow controller 200 further includes a second elastic holding device such as a second spring 244 coupled to the membrane valve 210 on one end, and a surface of the second chamber unit 214 at the other end. The second spring 244 pushes down on the membrane valve 210 to restrict water flow from the inlet chamber 202 to the outlet chamber 206.
[0040] The fluid flow controller 200 further includes a support 246 on which the beam balance 216 is positioned. In one embodiment, for example, the beam balance 216 is supported at a pivot point 248 using a pin. The support includes a first stopper 252 and a second stopper 254. The first stopper 252 prevents the beam balance 216 from tilting further when the fluid flow controller 200 is in open position. The second stopper 254 prevents the beam balance 216 from tilting further when the fluid flow controller 200 is in closed or second position (as describe in FIG. 3).
[0041] According to certain aspects of the present disclosure, operation of the beam balance 216 is configured such that a rate of evaporation of sample water from the fluid collection limb 218 is representative of a rate of evaporation of water from a designated area. Specifically, in certain embodiments, the pivot point 248 of the beam balance 216 is selected to be lower than the centre of gravity 250 of the beam balance 216 to cause the membrane valve 210 to open or close only once a determined weight of sample water evaporates, or collects in the fluid collection limb 218. The opening or closing of the membrane valve 210, in turn, opens or closes the water supply to the designated area.
[0042] For example, in one embodiment, the pivot point 248 is selected such that the fluid collection limb 218 moves down to the second or closed position and is stopped by the second stopper 254 once approximately 1 litre of sample water is collected in the fluid collection limb 218. During the sample water collection, the fluid flow controller 200 may be configured to supply equivalent of about10 millimetre (ml) of water layer to the designated area. In another embodiment, however, the pivot point 248 may be selected such that the fluid collection limb 218 moves to the closed position upon collecting 500 ml of sample water. Alternatively, the pivot point 248 may be selected such that the reference limb 220 moves down and is stopped by the first stopper 252 once at least 500 ml of sample water evaporates from the fluid collection limb 218. The bi-stable condition of the beam balance 216, thus, is not dependent on the actual difference in weight of the fluid collection limb 218 and the reference limb 220, but on selection of the pivot point 248. Selecting a particular position for the pivot point 248 allows control over hysteresis of the beam balance 216. This allows operation of the fluid flow controller 200 to be reconfigured by simply selecting appropriate pivot points to vary a rate and amount of sample water collected by, or evaporated from the fluid collection limb 218 before the fluid collection limb 218 moves to open or close the water supply to the designated area. As the a rate of evaporation of sample water from the fluid collection limb 218 can be configured to be representative of a rate of evaporation of water from the designated area, reconfiguration of the pivot point 248 allows the fluid flow controller 200 to open or close the water supply to the designated area, as needed, to address varying watering requirements of various crops. Particularly, the user may fix the pivot point 248 on the beam balance at different positions (e.g. by using a pin) to vary water supply to the designated area over time, for example, based on age of the crops, type of the crops, type of soil, evapotranspiration, and ambient conditions to maintain a desired moisture level.
[0043] In certain embodiments, the efficient opening and closing of the water supply is facilitated by the action of the O-magnet 234. In one embodiment, when the fluid collection limb 218 moves up, for example, due to evaporation of a determined amount of sample water, the connecting member 240 moves upwards along with the fluid collection limb 218. Because the connecting member 240 is connected to the O-magnet 234, the O-magnet 234 also moves up. Due to the magnetic force between the O-magnet 234 and the plunger 236, upwards movement of the O-magnet 234 causes the plunger 236 to move upwards. The upward movement of the plunger 236, in turn, leads to opening of a passage 256 between the outlet chamber 206 and the second chamber unit 214. Consequently, the pressure in the second chamber unit 214 decreases when the passage 256 is opened. Opening of the passage 256 causes water to flow from the first chamber unit 212, having comparatively higher pressure, towards the second chamber unit 214. Additionally, the membrane valve 210 is displaced upwards due to force of incoming water, which allows water to flow from the inlet chamber 202 to the outlet chamber 206. Subsequently, water exits the outlet chamber 206 through the outlet opening 208 and is delivered to plants via the drip line 116.
[0044] As water flows through the outlet chamber 206, a portion of water also flows through the sample feeding line 228 and reaches the planar shower 232. The planar shower 232 disperses this sample water into the holes 224 of the fluid collection limb 218 at a desired rate, for example a rate that represents a rate of water at which the designated area is being irrigated. Particularly, in certain embodiments, the rate of sample water filling the holes 224 is initially calibrated and adjusted using the sample rate control valve 230, such that, when the designated area is completely irrigated with a desired amount of water, the holes 224 are also filled with the designated amount of sample water. Filling the holes 224 with the designated amount of sample water causes the fluid collection limb 218 to move down, thereby automatically disposing the fluid flow controller 200 in the closed position once the designated area is irrigated.
[0045] In one embodiment, the designated amount of water required to tilt the beam balance 216 is calibrated initially by pivoting the beam balance 216 using a suitable position selected from a plurality of pivot positions 258A, 258B, and 258C disposed on the beam balance 216. For example, the designated amount of water required to tilt the fluid collection limb 218 may be comparatively more when the beam balance 216 is supported using at pivot position 258B instead of at pivot position 258A.
[0046] Downward movement of the fluid collection limb 218 upon collecting a determined amount of sample water causes the O-magnet 234 to move downwards. The magnetic force between the O-magnet 234 and the plunger 236, in turn, moves the plunger 236 downwards, thereby closing the passage 256. In one scenario, rainwater may be deposited in the holes 224 (via the openings 112 in the protective casing 110 of FIG. 1) in addition or in place of the sample water. Collection of a determined amount of rainwater and/or sample water may tilt the beam balance 216 toward the fluid collection limb 218, thereby moving the fluid flow controller 200 to a closed position.
[0047] FIG. 3 depicts an embodiment of the fluid–flow controller 200 in a closed position. Referring to FIG. 3, as the plunger 236 moves down, the passage 256 is blocked by the plunger 236. The fluid flow controller 200 is now in the second or the closed position. When the passage 256 is closed, the pressure in the second chamber unit 214 increases causing the second spring 244 to push the membrane valve 210 down and close the passage 256 between the second chamber unit 214 and the outlet chamber 206 to allow flow of the fluid to the defined area via the outlet chamber 206. The membrane valve 210, blocking the passage 256, is automatically maintained at the closed position due to an equal pressure in the first chamber unit 212 and the second chamber unit 214. In one embodiment, the equal pressure is achieved due to movement of water from the first chamber unit 212 to the second chamber unit 214 via the orifices 222. Thus, the membrane valve 210 restricts flow of water from the inlet chamber 202 to the outlet chamber 206 while in the closed position. Water does not enter the outlet chamber 206, thereby stopping supply of water to the plants.
[0048] The fluid flow controller 200 stays in this closed position. The sample water in the holes 224 of the fluid-collection limb 218 may eventually evaporate. The rate of evaporation depends on the surrounding atmospheric conditions such as dryness in the air, wind, temperature, etc. As noted previously, the crops in the designated area are also exposed to similar atmospheric conditions because the fluid flow controller 200 is installed in or around the area of the plants. Thus, the rate of evaporation of the sample water in the holes 224 and the rate of evaporation of the water from the designated area may be substantially similar. This is how the moisture level of the designated area may be maintained without directly measuring the moisture in the soil. As the water in the holes 224 evaporates, the reference limb 220 becomes heavier than the fluid-collection limb 218 and the beam balance 216 tilts toward the reference limb 220 and is stopped by the first stopper 252. In one example, the beam balance 216 can be designed such that it tilts when a designated or predefined amount/weight of water evaporates from the holes 224. The fluid flow controller 200 is again in the open position, and the process described with reference to FIGs 2 and 3 may repeat. Unlike conventional irrigation systems that utilize expensive sensors for directly measuring moisture content of soil, the drip irrigation system 100 indirectly senses moisture content of the designated area, and operates in a fully automatic manner for a particular irrigation scenario, without requiring any electricity and manual intervention.
[0049] Particularly, in certain embodiments, the drip irrigation system 100 requires initial calibrations while setting up the drip irrigation system 100 around the designated area. Once the initial calibrations are performed, the drip irrigation system 100 is fully functional in an automatic manner and does not require any further manual intervention. For example, the sample rate control valve 230 can be manually adjusted to control a rate of transport of water from the outlet chamber 206 to the plurality of holes 224 in the fluid collection limb 218. By calibrating time taken by the fluid collection limb 218 to collect a designated amount of water to be similar to the time taken for moisture level of the designated area to fall, water supply may be automatically opened to irrigate the plants when needed, rather than based on a predetermined schedule or via use of an electric sensor.
[0050] The second aspect that can be manually controlled is the hysteresis of the beam balance 216. The beam balance 216 includes the plurality of pivot positions 258A, 258B, and 258C to control hysteresis to decide the amount of weight difference between the fluid collection limb 218 and the reference limb 220 required for tilting the beam balance 216 from a first position to a second position. Therefore, the duration of the open and/or closed position of the fluid flow controller 200 can be adjusted. Specifically, the pivot point 248 of the beam balance 216 may be moved lower/higher to any of the pivot positions 258A, 258B, and 258C to change the amount or rate of collection of sample water, without changing the position of the beam balance 216 with respect to the support 246.
[0051] The above two manual settings, i.e., adjusting the sample rate control valve 230 and hysteresis control using the pivot positions 258A, 258B, and 258C, may be used to select the amount of water supply suited for a particular farm/area. After these manual controls are set, the fluid flow controller 200 may operate completely automatically to maintain the soil moisture level in different weather conditions.
[0052] The fluid flow controller 200 described above has several advantages. For example, there are no watertight joints for opening or closing the fluid flow controller 200, thereby eliminating any leakage problems. In conventional irrigation systems employing a ball valve-balance arm configuration, a fair amount of pressure is required to operate the valve between an open position and a closed position. Accordingly, a balance arm has to overcome the pressure of the valve by accommodating a large amount of water, which makes the balance arm bulkier.
[0053] Unlike such bulky conventional systems, the fluid flow controller 200 includes the compact beam balance 216 coupled to the lightweight O-magnet 234 that pulls the plunger 236 without any direct contact, leading to a light-weight and friction-less setup. Moreover, manufacturability of the fluid flow controller 200 is high due to simple and small parts. The size of the fluid flow controller 200 can be adjusted based on needs and can be further miniaturized, if needed. In one example, the fluid flow controller 200 can be designed to fit in 15 centimetre (cm) X 15 cm X 5 cm space (e.g., dimension of the protective casing 110 shown in FIG. 1).
[0054] Additionally, the bi-stable condition of the beam balance 216 can be adjusted using the pivot positions 258A, 258B, and 258C to configure the fluid flow controller 200 to switch between the open and closed positions based on the indirectly sensed water requirement of the designated area.
[0055] It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein, may subsequently be made by those skilled in the art, which are also intended to be encompassed by the following claims.