IL282760B1 - Apparatus and method for elevating water - Google Patents

Description

APPARATUS AND METHOD FOR ELEVATING WATER FIELD id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1"

[0001] The present invention relates to elevating liquids, such as water.

BACKGROUND[0002] Water is a necessary element of life and the availability of water has played a key role in the development of civilizations. Water can be transported from a water reservoir using gravity. However, providing water to elevated areas by elevating the water using any kind of known pump, requires the expenditure of energy, such as manual labor and/or use of electricity or fuel to activate the pump.[0003] Pumping water to higher elevation is used in many applications such as irrigation, flood control, desalination, home drinking water, production of electricity and many more. For example, water elevated to a height (high hydraulic head) gains potential energy which is then converted into kinetic energy as the water flows downward. This energy may be transformed to mechanical energy, which may be harnessed, for example, to generate electricity, as commonly used in pumped energy storage reservoirs.[0004] However, lifting to a high head a massive amount of water (which is required for generating electricity and other applications), involves the use of heavy and costly pumps that utilize expensive and polluting energy. Thus, the current use of pumps for elevating water is ineffective as well as polluting.

SUMMARY[0005] Embodiments of the invention provide an energy-wise cost-efficient solution to elevating massive volumes of water to high heads, by harnessing natural forces such as buoyancy and gravity.[0006] An apparatus for elevating water, according to embodiments of the invention, includes a water-filled ascending conduit in fluid connection with a water source and a device to force a container into a lower end of the ascending conduit. The container, which includes an enclosed volume of gas fixed to it, is filled with water, when pushed into the ascending conduit, and then, due to buoyancy imparted by the volume of gas, the container floats up through the ascending conduit, while maintaining the water filling it.[0007] The ascending conduit’s upper end is configured to cause the container to empty water carried in it, such that a volume of water carried up by the container from the lower end of the ascending conduit to its top, can be spilled out at the top.[0008] The ascending conduit may include a sleeve-like portion of reduced inner circumference relative to the ascending conduit inner circumference. The reduced inner circumference is similar to the circumference of the container. Consequently, when the container passes through the sleeve-like portion, the ascending conduit is blocked, such that this portion can essentially serve as a valve within the ascending conduit.[0009] The sleeve-like portion may be located at the upper end of the ascending conduit or in other locations along the ascending conduit.[0010] The apparatus may further include a descending conduit configured to receive an emptied container exiting from the upper end of the ascending conduit and to allow the emptied container to descend (typically by free-falling, pulled by gravity) to the level of the lower end of the ascending conduit.[0011] The apparatus may be used similarly to elevate any liquid. The ascending conduit may be filled with any liquid and the container may have attached to it an enclosed volume of gas or other substance of lower density than the liquid, to enable a liquid-filled container to float up through the liquid in the ascending conduit.[0012] Embodiments of the invention provide a liquid carrying container to be used for elevating the liquid with relatively little external energy input. The container, which has an enclosed volume of gas fixed to the container body, is configured to receive and maintain a volume of the liquid and move through a conduit comprising the liquid. Placing the liquid-filled container at the bottom of an ascending conduit will result in the container floating up through the liquid in the ascending conduit. Thus, a liquid can be passively elevated through the ascending conduit, in the container, due to buoyancy imparted to the container by the enclosed volume of gas. The liquid-filled container can be passively elevated to high heads within the ascending conduit, as long as there is liquid in the ascending conduit. id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13"

[0013] Expenditure of energy is required mainly to force an empty container into the ascending conduit, e.g., via a filling chamber, in order to fill it with liquid. However, since the liquid-filled container is then elevated within the ascending conduit due to buoyancy, embodiments of the invention provide a solution for elevating water using less energy expenditure than existing solutions, contributing to less use of electricity and/or fuels, thereby reducing environmental pollution.

BRIEF DESCRIPTION OF THE FIGURES id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14"

[0014] The invention will now be described in relation to certain examples and embodiments with reference to the following illustrative figures so that it may be more fully understood. In the drawings:[0015] Fig. 1 schematically illustrates an apparatus for elevating water, according to an embodiment of the invention;[0016] Figs. 2A and 2B schematically illustrate examples of an upper end of an ascending conduit, according to embodiments of the invention;[0017] Figs. 3A and 3B schematically illustrate portions of reduced circumference within an ascending conduit, according to embodiments of the invention; and[0018] Fig. 4 schematically illustrates a liquid carrying container, according to an embodiment of the invention.

DETAILED DESCRIPTION[0019] Embodiments of the invention provide cost effective, low energy apparatuses and methods for elevating liquids, such as water. The examples described herein refer to elevating water however, other liquids can be elevated using embodiments of the invention. By using an apparatus described herein, large volumes of liquid can be lifted to any height with a relatively small energy input.[0020] In one embodiment, which is schematically illustrated in Fig. 1, a water elevating apparatus 100 includes a water-filled ascending conduit 103, configured to enable unobstructed passage of a water-filled container upwards through it. A water source, such as bottom water reservoir 122, is in fluid connection with the ascending conduit 103, for example, via a filling chamber 123 located at the lower end 103’ of ascending conduit 103. id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21"

[0021] Located at or near the upper end 103’’ of ascending conduit 103, and in fluid connection with it, may be a buffer tank 121, designed to ensure that the level of water in the water-filled ascending conduit 103 does not fall beneath a pre-determined level.[0022] The apparatus 100 may further include a descending conduit 107 configured to enable unobstructed passage of an emptied container, downward through it (e.g., by sliding down), to the level of the lower end 103’, e.g., to a loading chamber 125 and filling chamber 123.[0023] Containers and conduits as well as other parts of the apparatus 100 may be made of unbreakable, non-corrosive, water impermeable materials, such as aluminum, stainless steel, suitable plastics, etc.[0024] A container is filled with water from a water source, e.g., reservoir 122, at filling chamber 123. The container then floats upwards via the ascending conduit 103 and exits the ascending conduit while emptying the water carried in it. The emptied container can then descend by gravity, via descending conduit 107 to the lower level of loading chamber 125.[0025] In some embodiments, the ascending conduit 103 is at an angle or is tilted relative to the ground. In other embodiments, the ascending conduit 103 includes a vertical portion and one or more angled or tilted portions. For example, tilted portions of the ascending conduit may create a route for a container which will assist in in emptying the water from the container and/or may assist in the passage of a container from ascending conduit 103 to descending conduit 107.[0026] In some embodiments, a channel 106 connects the upper end 103’’ of ascending conduit 103 with the upper end 107’’ of descending conduit 107. The upper end 103’’ of ascending conduit 103 is typically higher than the upper end 107’’ of descending conduit 107, such that channel 106 which connects these two ends, is sloped and can passively guide a container exiting the ascending conduit 103 into the descending conduit 107, based on gravity. [0027] The apparatus 100, typically ascending conduit 103 may include one or more one­way valves to ensure that water does not leak out, e.g., from the filling chamber 123 and/or from the lower end 103’ of ascending conduit 103.[0028] Apparatus 100 will further be described by following a cycle of a container generally designated 12, through the different parts of apparatus 100. Different letters are assigned to the container 12 (12a, 12b, 12c and 12d) at different locations within the apparatus 100. id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29"

[0029] The container 12 includes a body having a closed end 12’ and an open end 12’’ through which to receive and expel water. Additionally, an enclosed volume of gas, such as an air bubble 13, is fixed to the container body. In the example illustrated in Fig. 1, air bubble 13 is fixed inside the container to the closed end 12’ of the container.[0030] In a first step, an initially empty container 12 in loading chamber 125, is forced, by a piston 105, into filling chamber 123 (which is typically part of ascending conduit 103) which is connected to a bottom water reservoir 122. Piston 105 typically pushes container 12 into filling chamber 123, with its open end 12’’ first, through a one-way valve, which may include, for example, a rubber diaphragm 131 located at the entrance to filling chamber 123. Alternatively or in addition, a one-way valve 132 can be located within the filling chamber 123 instead of or directly following diaphragm 131. In some embodiments, a one-way valve 133 is located at the opposing end of filling chamber 123, separating filling chamber 123 from other parts of ascending conduit 103. Valve 133 may be opened once valve 132 is closed, to allow the now water-filled container (referred to as 12a) to pass into the continuation of ascending conduit 103.[0031] The use of diaphragm 131 and/or valves 132 and 133, enables container 12 to enter filling chamber 123 from the dry environment of loading chamber 125, and exit from filling chamber 123 to other parts of ascending conduit 103, while avoiding leakage of water from the ascending conduit (e.g., from filling chamber 123).[0032] The action of piston 105 is required to push the empty container 12 into filling chamber 123 and to overcome the fluid resistance force generated at the interface of water and air, when an empty container is pushed into a water filled chamber.[0033] Once in the water-filled filling chamber 123, the container 12a will passively fill with water. The air in container 12a, which was replaced by water, may escape via an air release vent 135. The apparatus 100 may further include a one-way valve 137 to enable flow of water from the bottom water reservoir 122 to filling chamber 123 when needed.[0034] After exiting the filling chamber 123, e.g., via valve 133, the water-filled container (now referred to as 12b) will float upward through water-filled ascending conduit 103 due to the buoyant force (enhanced by air bubble 13) applied on container 12b.[0035] Water-filled container 12b is elevated to the upper end 103’’ of ascending conduit 103, which is configured to allow a container to exit the ascending conduit 103. Thus, the volume of water carried in container 12b has been elevated to the top of ascending conduit 103 by buoyancy forces with the only other energy input being the energy required to operate piston 105 and possibly short range pumps and valves, such as valves 132 and 133. [0036] Typically, most of the energy input to the operation of apparatus 100 is required for operating the piston 105. However, the amount of energy required for operating piston 105, is almost the same, regardless of the height of ascending conduit 103. For example, almost the same amount of energy is required to push container 12 into filling chamber 123, if ascending conduit is, e.g., 50 meters or 200 meters. Thus, the efficiency of apparatus 1increases as liquids are elevated to higher heads.[0037] Piston 105 may include any suitable device for pushing a container. Piston 105 may include a mechanical device having an electronic controller, e.g., for automatically operating the device whenever a container is in position in loading chamber 125, to be pushed into the filling chamber 123. For example, the electronic controller may include a timer to operate piston 105 at pre-set times. In other embodiments the electronic controller may include a motion sensor, pressure sensor and/or other suitable sensors to detect the presence of a container and to activate the piston 105 accordingly.[0038] Once the container (now referred to as 12c) reaches the top and exits ascending conduit 103, the water carried in it may be emptied (as indicated by the dashed arrow), e.g., into a top reservoir 124. Container 12c exiting ascending conduit 103, typically falls into descending conduit 107, possibly via channel 106. Container 12c passively moves or slides through channel 106 due to gravity, falling into descending conduit 107.[0039] Typically, channel 106 contains openings, or is made of a mesh or is otherwise configured to allow water being emptied from container 12c to fall, e.g., into top reservoir 124, as exemplified by the dashed arrow. Channel 106 may include, for example, a sleeve of spaced plastic or stainless steel wires or a plastic or stainless steel mesh sleeve connecting the upper end 103’’ of ascending conduit 103 and the upper end 107’’ of descending conduit 107. Channel 106 may be made of other suitable materials.[0040] Once in descending conduit 107, the now emptied container (referred to as 12d) passively falls, pulled by gravity, through descending conduit 107 to the lower end 107’ of descending conduit 107, which leads to loading chamber 125. id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41"

[0041] Loading chamber 125 is configured to receive an empty container from descending conduit 107 and to align the empty container with the opening of filling chamber 123 (e.g., with diaphragm 131) and with piston 105 such that a container 12 can be pushed, open end first, into the filling chamber 123.[0042] Thus, a container, which has been passively filled with water and pushed upward by buoyant forces, as described above, empties the water carried in it, at a height, and is delivered passively back to the level of loading chamber 125, where piston 105 can force it into the filling chamber 123 to begin a new cycle of elevating water.[0043] In one embodiment, the ascending conduit’s 103 upper end 103’’ is constructed so as to cause a water-filled container to empty the water carried in it, prior to moving into descending conduit 107. In one embodiment the upper end 103’’ of ascending conduit 1causes a water carrying container (e.g., container 12c) exiting from it, to tilt, thereby emptying the water carried in it. For example, the upper end 103’’ may include an angled unloading unit (as described below) or may include an obstacle thereby forcing container 12c, which is passing through, to tilt.[0044] In some embodiments, water being emptied from the water-carrying container 12c may fall into a reservoir (e.g., into top reservoir 124), and may then be used, e.g., for agriculture, for municipal needs, for pumped storage energy, to generate electricity ( e.g., by dropping the water from upper reservoir 124 via a turbine that converts the potential and kinetic energy of the falling water to mechanical energy and then to electric energy), for water purification and more.[0045] Ascending conduit 103 may include one or more one-way valve such as valves 132, 133 and 134, to allow a water carrying container such as container 12a and 12b, to pass through while controlling the large volume of water maintained within the ascending conduit 103.[0046] Valves 132, 133 and/or 134 may include a mechanical valve, e.g., operated by pressure and/or an electronic valve, e.g., using appropriate sensors to detect an approaching container and to open/close accordingly. Valves 132, 133 and 134 may include, for example, a ball valve, gate valve (e.g., a pneumatic gate valve) or a plunger valve (e.g., a normally closed fast response solenoid valve). In other embodiments one or more of valves 132, 1and 134 may include a portion of reduced diameter, as further described below. id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47"

[0047] One or more valves, such as valve 134, positioned along ascending conduit 103 may divide the volume of water in the ascending conduit 103 to compartments such that less hydrostatic pressure is felt in each compartment, enabling to construct a very high ascending conduit without having to deal with too high hydrostatic pressure. For example, the pressure felt at the bottom of a 100 meter high ascending conduit will be approximately atmospheres, however, if the height of the conduit is divided by valve 134 to two compartments of 50 meters, the pressure at the bottom of both compartment will only be approximately 5 atmospheres.[0048] Typically, when a water-carrying container 12c exits the ascending conduit 103, a volume of water essentially equal to the volume of the container, will be removed from the body of water in the ascending conduit 103. Thus, with each container exiting the ascending conduit 103, the level of water 143 in the ascending conduit may decrease. Since container 12c is elevated by buoyancy through the water in ascending conduit 103, it will only be elevated to the height of the level of water 143 at the top of ascending conduit 103. Thus, a large enough decrease in the level of water 143 in ascending conduit 103 may lower the height of elevation of container 12c to an extent that may prevent the container 12c from exiting the conduit 103.[0049] To avoid this situation, a desired, typically pre-determined, level of water should be maintained in ascending conduit 103. One solution for maintaining a pre-determined level of water in ascending conduit 103, includes the use of a buffer tank 121, which is located at or in vicinity of the upper end 103’’ and which is in fluid communication with conduit 103. Buffer tank 121 is filled with water that can be added to ascending conduit 103 as necessary, to maintain a desired level of water in conduit 103. For example, the level of water 141 in buffer tank 121 may be kept at the desired pre-determined level, which is also the initial water level 143 in conduit 103, such that when the water level in conduit 103 falls below its’ initial level, water will flow from buffer tank 121 to conduit 103 in accordance with the principle of communicating vessels.[0050] Buffer tank 121 may be filled to constantly maintain the pre-determined level of water in it, e.g., by pumping water into it from top reservoir 124 or from another source that is located close to the buffer tank 121. A short range pump may be used since top reservoir 1(or another source) is located within a short distance from the buffer tank 121. Pumping water from a reservoir in short range from the buffer tank 121 requires a small amount of energy, as opposed to pumping water from a further located source.[0051] In some embodiments, examples of which are described with reference to Figs. 2A and 2B, the upper end of the ascending conduit is designed to help mitigate the problem of a decreasing water level in the ascending conduit.[0052] In one embodiment, a basin 211 (funnel shaped in Fig. 2A and cylinder shaped in Fig. 2B), having a larger perimeter than ascending conduit 203, is constructed at the upper end 203’’ of ascending conduit 203. The basin 211 is in fluid connection with the ascending conduit 203, such that the basin 211 contains water but at a larger volume per perimeter, than the volume of water at the upper end 203’’, because of the larger perimeter of basin 211. Due to the larger volume of water in basin 211, a decrease of the liquid level 214 in basin 211 will be slower than a similar decrease at the upper end 203’’ were it not to include a basin.[0053] Typically, an unloading unit 213 is attached to (or is part of) the upper end 203’’ of the ascending conduit 203. The unloading unit 213 may be an angled continuation of ascending conduit 203 and/or another portion attached at an angle to ascending conduit 2at its’ upper end 203’’. A container passing through the unloading unit 213 will be tilted relative to its route within ascending conduit 203 (and relative to the ground), and will therefore empty any liquids carried in it, due to gravity.[0054] Another solution to maintaining a pre-determined level of water in ascending conduit 203 includes the use of a novel valve 204. Valve 204 is configured to create a narrowing of the conduit 203. The valve 204 creates a portion having an inner circumference which is similar to dimensions of a liquid-carrying container, such that a container passing through will essentially block the conduit 203 while it is in the valve 204.[0055] In some embodiments, the upper end 203’’ of ascending conduit 203 includes a valve 204, as described above, such that substantially no liquid can exit the conduit 203 as long as containers are passing through the narrower portion created by valve 204, thereby delaying a decrease in the liquid level within the ascending conduit 203.[0056] As schematically illustrated in Figs. 3A and 3B, ascending conduit 303 includes a valve 304. The valve 304 may be situated at locations along the conduit 303, e.g., to divide the conduit to compartments for reducing the hydrostatic pressure, as described above and/or the valve 304 may be situated at the top end of conduit 303 to prevent loss of water from the conduit, as described above.[0057] In the embodiment exemplified in Fig. 3A, valve 304 is composed of a sleeve-like portion, referred to as sleeve 314, of reduced inner circumference relative to the inner circumference of conduit 303. Sleeve 314 may be made of pliant material, such as silicon or rubber. The reduced inner circumference of sleeve 314 is similar to dimensions of a water­carrying container 302. In some embodiments, the diameter of the inner circumference of sleeve 314 is similar (almost exactly the same) as the diameter of the largest (or broadest) part of container 302, for example, the diameter of the rim of container 302. Thus, a water-carrying container 302 substantially blocks sleeve 314 (and thereby blocks conduit 303) when passing through it.[0058] In the embodiment exemplified in Fig. 3B, valve 304 is composed of fins 324 that are made of pliant water proof material, such as silicon or rubber. One or more spaced apart ring of fins is attached to the inner circumference of conduit 303. The fins 324 are inclined downwards such that when a container 302 floating upwards through the valve 304 pushes through the ring of fins 324, the fins yield to let the container through but then return to their inclined downwards position. Because the fins are made of water proof material, water can pass through valve 304 only through the inner circumference 304’ created by fins 324. The inner circumference 304’ is similar to (or possibly slightly smaller than) the dimensions of a water-carrying container 302, such that a water-carrying container 302 substantially blocks the inner circumference 304’ (and thereby blocks conduit 303) when passing through it.[0059] In this way, a valve 304 which includes pliant material and creates a portion of reduced dimension, namely, dimensions that are almost exactly the same as (or possibly slightly smaller than) the dimensions of the largest or broadest part of a container passing through, can provide the above mentioned advantages.[0060] In some embodiments, the water-carrying container 302 includes a gasket 3encircling the body of the container 302. In some embodiments the gasket 308 is the largest part of the container 302. Gasket 308 may be made of sealant material such as rubber, to facilitate blocking of valve 304 when container 302 passes through it.[0061] In another embodiment (not shown), a container 302 may include a motor or other propelling device to impart a turning motion to the container. The container 302 body may include helical ridges around it (similar to threads of a screw) and a valve 304 in conduit 3may include helical grooves such that the ridges of a container passing through valve 3(possibly in a turning motion) fit the grooves of the valve, enabling the container to move up and out of the valve while blocking the conduit.[0062] In some embodiments, a plurality of containers 302 pass through conduit 3consecutively, such that valve 304 is almost always blocked, serving as an always closed valve, to divide the volume of water in conduit 303 to compartments and/or to prevent loss of liquid from conduit 303, as described above.[0063] In some embodiments, the conduit 303 dimensions (e.g., inner circumference) enable passage of a plurality of water-carrying containers in a single file line. The plurality of containers 302 may be attached to each other in series, e.g., by attachment cables 306, such that the buoyant forces of all the connected containers will act to overcome possible friction between a container passing in the valve 304 and the inner circumference of valve 304, and will help push/pull each container through the valve 304.[0064] Attachment cables 306 may be made of pliant material to enable essentially unrestricted movement and tilting of each of the containers.[0065] Thus, in some embodiments, an apparatus for elevating water, includes a water-filled ascending conduit having an inner circumference which enables upwards passage of a water­carrying container. The ascending conduit includes a portion of reduced inner circumference (relative to the inner circumference of the ascending conduit), which is similar to the circumference of the water-carrying container.[0066] An example of a liquid carrying container, according to embodiments of the invention, is schematically illustrated in Fig. 4.[0067] The container 400 has a body with a first end 414 which is closed and a second end 424 which is open, through which to receive and expel liquid. The container 400 includes an enclosed volume 404 of a substance of smaller density than the liquid, the enclosed volume 404 being fixed to the container 400 body, typically to the closed end (first end 414) of the container 400, within the container body, however, the enclosed volume 404 may be fixed to the container 400 body at other locations that can promote buoyancy of container 400 when filled with the liquid. id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68" id="p-68"

[0068] Although air is preferable, enclosed volume 404 may include a closed vessel (bubble) filled with one or a mixture of smaller density substances, e.g., gaseous substances such as air, helium gas, neon, nitrogen, ammonia, methane, carbon monoxide and more.[0069] The enclosed volume 404 may consist of about 5-30% of the volume of the entire container 400. In one embodiment, an enclosed volume of air consists of about 9 – 17% of the volume of a water carrying container.[0070] As discussed above, expenditure of energy required for elevating liquid, according to embodiments of the invention, is much reduced compared with existing solutions. Thus, embodiments of the invention provide cost effective, low energy apparatuses and methods for elevating liquids, such as water. The apparatuses and methods can be used, for example, in lifting water for irrigation and other agricultural uses, filling reservoirs, municipal water uses, extinguishing fires, water desalination and other water purification processes, generating hydro electrical energy, pumped-storage hydroelectricity, and many more.[0071] The data in Table I below (which was calculated based on experiments using a prototype of apparatus 100), demonstrate the applicability of apparatuses and methods, according to embodiments of the invention, in generating electricity.

Table IVolume of water-carrying container - gross (Liter) Diameter of ascending conduit (Inch) Volume of enclosed air bubble- approx. (Liter) Volume (net) of water being lifted (Liter) Height of ascending conduit head (Meter) Potential of generated electricity (kWh) 120 20 20 100 10 83.33220 24 20 200 10 166.67220 24 20 200 30 500 (1/2MW)120 20 20 100 20 166.67220 24 20 200 20 333.33220 24 20 200 180 2,000 (2MW) id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72" id="p-72"

[0072] The energy required to force an empty container into a body of water at 30 meters head, according to embodiments of the invention, is less than 45% of the energy required for elevating a same amount of water using existing standard pumps. The efficiency of the process of elevating water is even higher at higher heads, since almost the same amount of energy is required to be input, (e.g., to operate a piston and valves) regardless of the height of the ascending conduit. Thus, the efficiency of apparatuses and methods according to embodiments of the invention, increase as liquids are elevated to higher heads.[0073] Thus, embodiments of the invention provide a highly efficient, environment friendly and non-polluting solution for elevating liquids.

ABSTRACTThe apparatus described herein harnesses natural forces to elevate massive amounts of water to high heads, while saving energy and costs. The apparatus uses a buffer tank in vicinity to and in fluid communication with a water-filled ascending conduit, through which a water-carrying container can float up to a maximal height where it can be emptied and can fall to repeat its’ ascend through the ascending conduit. The use of the buffer tank ensures that the level of water in the water-filled ascending conduit does not fall beneath a pre-determined level, thereby enabling the apparatus to operate continuously with minimal cost and energy expended on pumping water into the ascending conduit.

Claims (17)

Claims

1. An apparatus for elevating water, the apparatus comprising: a water-filled ascending conduit having an inner circumference which enables upwards passage of a water-carrying container, the ascending conduit comprising an upper end, the upper end comprising a portion having an inner circumference which is similar to dimensions of the water-carrying container, such that the water-carrying container passing through the portion essentially blocks the ascending conduit, delaying a decrease in a level of water within the ascending conduit, ensuring a pre-determined level of water in the ascending conduit.

2. The apparatus of claim 1 wherein the pre-determined level of water is an initial level of water in the ascending conduit, the apparatus comprising a buffer tank located in vicinity of the upper end, said buffer tank being filled with water that can be added to the ascending conduit, to maintain the initial level of water in the ascending conduit.

3. The apparatus of claim 2 configured to enable water to flow from the buffer tank to the ascending conduit in accordance with the principle of communicating vessels.

4. The apparatus of claim 2 comprising a water source in vicinity of the buffer tank and a pump to constantly fill the buffer tank to maintain the initial level of water in the ascending conduit.

5. The apparatus of claim 4 wherein the pump is a short range pump.

6. The apparatus of claim 1 comprising a piston to force the water-carrying container into the ascending conduit.

7. The apparatus of claim 1 wherein the upper end of the ascending conduit is configured to cause the water-carrying container to empty water carried in it.

8. The apparatus of claim 7 wherein the upper end of the ascending conduit is configured to cause the container to tilt, thereby emptying the water carried in it.

9. The apparatus of claim 7 comprising a descending conduit configured to receive an emptied container exiting from the upper end of the ascending conduit and to allow the emptied container to descend to a level of a lower end of the ascending conduit.

10. The apparatus of claim 9 wherein the descending conduit is configured to allow the emptied container to descend by gravity.

11. The apparatus of claim 1 wherein the ascending conduit comprises a vertical portion and an angled portion.

12. The apparatus of claim 1 wherein the ascending conduit is configured to enable passage of a plurality of containers in a single file line, wherein the plurality of containers are attached to each other.

13. The apparatus of claim 1 wherein the water-carrying container comprises a body having a first end which is closed and a second end which is open through which to receive and expel water.

14. The apparatus of claim 13 wherein the water-carrying container comprises an enclosed volume of gas fixed to the container body.

15. The apparatus of claim 14 wherein the enclosed volume of gas is fixed within the container body to the first end of the body.

16. The apparatus of claim 14 wherein the enclosed volume of gas consists of about 5%-30% of a volume of the container.

17. The apparatus of claim 14 wherein the enclosed volume of gas comprises one or a mixture of gasses.