TECHNICAL FIELD OF THE INVENTION

This invention relates to hydro-powered water distribution systems.

BACKGROUN D

With increasing pressure on natural resources, systems for collecting and storing water from a natural or previously-used source (so-called grey water) and re-distributing it to a point of use are becoming increasingly popular. In a typical system, surface water may be collected and stored in an underground storage tank from which water is pumped to one or more points of use, which may typically include flushing of toilets, watering gardens and the like. The installation of present systems is expensive and often inconvenient, requiring extensive excavation work to accommodate the underground tank. Moreover, in commercially available systems an electric pump is used to redistribute the stored water which means that a suitable electricity supply must be provided. Apart from the cost of electricity, a convenient supply is not always available, and in remote areas the installation of costly wind or solar powered equipment may also be necessary.

Ram pumps which operate on the water hammer principle are well known. WO 2011/124 909 Al discloses a particularly efficient fluid pressure amplifier which is suitable for converting high flows at low pressure into low flows at higher pressure for delivery to elevated levels or other uses which require increased supply pressure. Ram pumps in general require an outlet head which is at least twice that of the inlet head and will cease to operate when the outlet head approaches that of the inlet head. Furthermore, traditional ram pumps often use an air bleed accumulator that introduces air into the delivery system to reduce cyclic shock and improve performance, but such systems are prone to blockages and are not very efficient as air is continually absorbed into the water requiring constant overcharging. When the supply is intermittent or variable traditional ram pumps tend to either draw air into the system and stop altogether or become highly inefficient, utilising only a small fraction of the available flow.

When grey water is to be used in clean environments, stored, or used for human consumption, it is desirable to incorporate water treatment to reduce or eliminate bacteria and viruses. Very effective water treatment systems exist, but these often need a constant water pressure to operate safely.

Previous attempts at using hydraulically operated pumps for water distribution have therefore been inherently inefficient (water recovery typically being around 5%) and they usually need to be supplemented by electrically powered pumps. Such systems could even be dangerous if a sufficient distribution pressure is not maintained for effective water treatment.

The present invention seeks to provide a new and inventive form of water collection and distribution system which does not require an electrical supply but which is nevertheless capable of operating with good efficiency. SUMMARY OF THE INVENTION

The present invention proposes a hydro-powered water distribution system which includes:

- a collection tank to receive and store a supply of water;

- a fluid pressure amplifier having a fluid inlet to receive water from the collection tank located at a higher level, said fluid pressure amplifier containing a resilient obturator member and having a fluid outlet;

- at least one storage tank to receive water from the fluid pressure amplifier;

- a level sensor to provide a hydraulic output signal in response to a fall in water level within the collection tank; and

- a hydraulically-operated control valve responsive to the hydraulic output signal from the level sensor to stop water passing through the fluid pressure amplifier when the water level falls in the collection tank.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier with a low pressure exhaust outlet, a high pressure delivery outlet, and a hydraulically-operated control valve connected to the exhaust outlet.

The invention also provides a hydro-powered water distribution system including a hydraulically-operated control valve which includes a valve member operated by a diaphragm in a pressure chamber and the diaphragm is moved by differential pressure.

The invention also provides a hydro-powered water distribution system including a level sensor which includes a float which is arranged to operate a hydraulic distributor valve. The invention also provides a hydro-powered water distribution system including a hydraulic distributor valve which has a fluid inlet port which is switched between a high-level fluid outlet port and a low-level fluid outlet port.

The invention also provides a hydro-powered water distribution system including a hydraulic distributor valve having a pair of outlet ports one of which is vented when the other outlet port is connected to a fluid inlet port.

The invention also provides a hydro-powered water distribution system including level sensor which includes a float which moves between a high-level detent position and a low-level detent position.

The invention also provides a hydro-powered water distribution system including a momentum enhancement chamber connected between a collection tank and a fluid inlet of a fluid pressure amplifier.

The invention also provides a hydro-powered water distribution system including a momentum enhancement chamber which contains a fluid conduit which is substantially longer than any linear dimension of the chamber.

The invention also provides a hydro-powered water distribution system including at least one screening filter connected in-line between a collection tank and a momentum enhancement chamber.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier arranged to supply water via a water treatment unit. The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier arranged to supply water to a low level storage tank and a high level storage tank.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier arranged to supply water to a slow-release tank provided with a restricted output to release water at a controlled rate.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier arranged to supply water to a pressurised accumulator.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing together with a hydraulically-operated control valve.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing together with a momentum enhancement chamber.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing together with a pressurised accumulator.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing together with a screening filter.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing together with a water treatment unit.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing which is associated with a storage tank.

The invention also provides a hydro-powered water distribution system including a fluid pressure amplifier contained within a distribution housing which is associated with a slow-release tank.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings:

Figure 1 is a schematic diagram showing a first hydro-powered water distribution system in accordance with the invention;

Figure 2 is a schematic diagram showing a second hydro-powered water distribution system in accordance with the invention;

Figure 3 is a general view of a preferred hydraulic level sensor and control valve for use in the distribution systems shown in a cut-off position; and

Figure 4 is a similar view to Fig. 3 but showing the level sensor and control valve in their pump-enabled positions.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Fig. 1, the drawing shows a self-powered water distribution system which is suitable for low demand uses such as domestic dwellings. The system is quick to install and unobtrusive due to its above-ground installation and modular construction .

Water collected from an intermittent natural source, e.g. from a roof 1 by gutters 2, is conducted by downpipe 3 to a high-level collection tank 4, preferably installed just below gutter level. The tank incorporates a first flush mechanism with a tilting channel 5 which is pivotally mounted to direct water into the main part of tank 4 or alternatively into a sump 6. The channel 5 is connected by a link 7 through an overflow downpipe 8 to a float 9 housed within a float chamber 10 provided with a small bottom outlet hole. The first flush mechanism is balanced such that the channel 5 will normally divert incoming water into the sump 6 while the float 9 closes the outlet of the float chamber. When water starts to flow from the downpipe 3 it is initially directed into the sump 6 and along the overflow pipe 8 into the float chamber 10. As the water level rises in the float chamber the float will lift and allow the channel to tilt and direct water into the collection tank 4. Eventually the float chamber will empty through its restricted outlet into a storm water drain 11 allowing the channel to tilt back to the rest position. Such a first flush event will therefore take place every time a new water inflow occurs. The first flush mechanism thus intercepts the initial part of each inflow and discharges it into the drain, thereby removing debris and silt that can build up in roofs and gutters during dry periods.

Within the tank 4 there is a coarse primary screen 20 which filters the collected water before entering a supply pipe 21. The collection tank also contains a float-operated sensor 22 (see below) which provides a hydraulic output through a control pipe system 23 whenever the water level within the collection tank falls below a predetermined level. The sensor 22 also signals via the control pipe system 23 when the water level rises above a predetermined level. The collection tank 4 is preferably covered by a lid 25 to prevent direct entry of bird droppings or other contamination.

A distribution housing 30 is mounted at a lower level than the collection tank 4, typically just above ground level. The supply pipe 21 enters the top of the housing 30 to feed a fine secondary screen 31, occupying a top part of the housing, to remove microparticles from the incoming water supply. After passing through the screen 31, the filtered flow enters a momentum enhancement chamber 32 which occupies a lower portion of the housing below the screen 31. Essentially this chamber comprises a relatively long fluid conduit (typically tens of metres in length) which is condensed into a relatively small space within the chamber. Upon reaching the remote end of the conduit, water enters the inlet port of an hydraulically-operated pump 34, mounted on the chamber 32. Although a conventional hydraulic ram pump may be used it is preferred to use a fluid pressure amplifier as described in WO 2011/124 909 Al, which is capable of being fine-tuned to operate with optimum efficiency at relatively low pressure differentials, the disclosure of which is incorporated herein by reference. The fluid pressure amplifier contains a resilient obturator member which oscillates against a seat within the amplifier to interrupt fluid flow between the input port and an exhaust port. As a result, a pulsed high pressure flow of water can be obtained from a delivery outlet via an internal venturi valve incorporated within the pump. A control valve 35 (see below) is connected to an exhaust port of the fluid pressure amplifier, hydraulically operated by the level sensor 22 via the control pipe system 23. By opening and closing the control valve 35 the pump can be turned on and off automatically so that the pump only operates when the head of water within the collection tank 4 is sufficient to maintain a good pressure and efficiency at the delivery outlet of the pump.

The momentum enhancement chamber 32 has the effect of increasing the cyclic flow of water into the pump 34 causing it to operate at a reduced speed but with higher efficiency. The chamber also makes the system less tolerant of variations in the head of water on the input side due to differences in layout or variations in level within the collection tank 4.

The outlet flow from the exhaust port via control valve 35 is still at a relatively low pressure and may simply be discarded direct to the drain 11, but it is preferred to divert the flow to a low level storage tank 36, the contents of which can be used for watering gardens etc. The tank 36 has an overflow 37 leading to the drain 11. An important additional feature of the present system is that, in the event of a storm surge which is sufficient to fill the storage tank 36, excess water can overspill into a slow-release tank 38 which slowly releases its contents into the drain 11 via a restrictive port and/or narrow-bore pipe 39. The overflow 37 only comes into operation when both thanks 36 and 38 become full. This retention and slow release of storm water into the drainage system can materially contribute to flood prevention by reducing the overall volume of water entering sewers and river courses during a flash storm surge. The high pressure delivery outlet from the pump 34 passes via an in-line water treatment unit 40 (e.g. iodine treatment, chlorination or reverse osmosis) contained within the housing 30, following which the treated water passes via a delivery pipe 41 to a high level storage tank 42, which may for example be situated in a loft space above the level of the collection tank 4. The tank 42 may provide a supply of clean drinking water, for washing or bathing etc., which may, as a back-up, be supplemented by a supply from a water main 44 via a float valve 45. Clearly the delivery outlet of the pump can supply water for purposes such as toilet flushing which need not necessarily pass through the treatment unit 40. Alternatively, the high pressure water may be stored in a low level pressurised storage vessel from which it can again be distributed to higher levels.

The distribution housing 30 provides a compact unit incorporating the momentum enhancement chamber, secondary filtration, pump, water treatment etc. in a single unit which is simple and convenient to install. The housing can provide all the correct apertures and connections for the various pipes and any taps that may be required. Furthermore, to further simplify the plumbing requirements the housing incorporates an additional compartment 46 containing the first flush float chamber 10 and lower end of the downpipe 8.

Fig. 2, shows a water distribution system which is suitable for higher demand uses such as small commercial establishments. Water collected from natural sources, e.g. from roofs 1 by gutters 2, is conducted by downpipes 3 to a high-level collection tank 4 (preferably installed just below gutter level). The tank incorporates a first flush mechanism with a tilting channel 5 which is pivotally mounted to direct water into the main part of tank 4 or alternatively into a sump 6. The channel 5 is connected by a wire 7 through an overflow downpipe 8 to a float 9 housed within a float chamber 10 provided with a small bottom outlet hole. The first flush mechanism is balanced such that the channel 5 will normally divert incoming water into the sump 6 while the float 9 closes the outlet of the float chamber. When water starts to flow from the downpipe 3 it is initially directed into the sump 6 and along the overflow downpipe 8 into the float chamber 10. As the water level rises in the float chamber the float will lift and allow the channel to tilt and direct water into the collection tank. Eventually the float chamber will empty through its restricted outlet into a storm water drain 11 allowing the channel to tilt back to the rest position. A first flush event will therefore take place every time a new water inflow occurs. The first flush mechanism thus intercepts the initial part of each inflow and discharges it via overflow 8, thereby removing debris and silt that can build up in roofs and gutters during dry periods.

Within the tank 4 are installed one or more filters 20 which screen and filter the collected water before entering a supply pipe 21. The collection tank also contains a float-operated sensor 22 (see below) which provides a hydraulic output through a control pipe system 23 whenever the water level within the collection tank falls below a predetermined level. The sensor 22 also signals via the control pipe system 23 when the water level rises again above a predetermined level. The collection tank 4 is covered by a lid 25 to prevent direct entry of bird droppings or other contaminating objects.

A distribution housing 30 is mounted at a lower level than the collection tank 4, typically just above ground level. The supply pipe 21 enters the top of the housing 30 via a momentum enhancement chamber 32. This chamber comprises a relatively long fluid conduit (typically tens of metres in length) which is coiled or otherwise condensed into a relatively compact space within the chamber. At the outlet end of the momentum enhancement chamber 32, which lies within the housing 30, water enters the inlet port of an hydraulically-operated pump 34. Although a conventional hydraulic ram pump may be used it is preferred to use a fluid pressure amplifier as described in WO 2011/124 909 Al, which is capable of being fine-tuned to operate with optimum efficiency at relatively low pressure differentials, the disclosure of which is incorporated herein by reference. The fluid pressure amplifier contains a resilient obturator member which oscillates against a seat within the amplifier to interrupt fluid flow between the input port and an exhaust port. As a result, a pulsed high pressure flow of water can be obtained from a delivery outlet via an internal venturi valve incorporated within the pump. A control valve 35 (see below) is connected to an exhaust port of the fluid pressure amplifier, hydraulically operated by the level sensor 22 via the control pipe system 23. By opening and closing the control valve 35 the pump can be turned on and off automatically so that the pump only operates to pass water when the head of water within the collection tank 4 is sufficient to maintain a good pressure and efficiency at the delivery outlet of the pump.

The momentum enhancement chamber 32 has the effect of increasing the cyclic flow of water into the pump 34 causing it to operate at a reduced speed but with higher efficiency. The chamber also makes the system less tolerant of variations in the head of water on the input side due to differences in layout or variations in level within the collection tank 4.

The outlet flow from the exhaust port via control valve 35 is still at a relatively low pressure and may simply be discarded direct to the drain 11, but it is preferred to divert the flow to a low level storage tank 36, the contents of which can be used for watering gardens etc. The tank 36 has an overflow 37 leading to the drain 11. An important additional feature of the present system is that, in the event of a storm surge which is sufficient to fill the storage tank 36, excess water can overspill into a slow-release tank 38 which slowly releases its contents into the drain 11 via a restrictive port and/or narrow-bore pipe 39. The overflow 37 only comes into operation when both thanks 36 and 38 become full. This retention and slow release of storm water can materially contribute to flood prevention by reducing the overall volume of water entering sewers and river courses during a flash storm surge.

Attached to the pump outlet is an accumulator 48 which can either be a pre-charged diaphragm or bladder type accumulator, an automatic air charge accumulator, or a spring accumulator. The accumulator absorbs pressure pulses and helps to provide more efficient delivery of water. The high pressure delivery outlet from the pump 34 passes via a delivery pipe 41 to a high level storage tank 42, which may for example be situated on a roof above the level of the collection tank 4. The tank 42 may provide a supply of water for washing, bathing, toilet flushing etc. which may, as a back-up, be supplemented by a supply from a water main 44 via a float valve 45. Alternatively, the high pressure water may be stored in a low level pressurised storage vessel from which it can again be distributed to higher levels.

The distribution housing 30 provides a compact unit incorporating the momentum enhancement chamber, pump, accumulator, storage tanks 36 and 38 etc. in a single unit which is simple and convenient to install. The housing can provide all the correct apertures and connections for the various pipes and any taps that may be required.

The level sensor 22 and control valve 35 may take various forms but a preferred form of level sensor and control valve are shown in Fig. 3. The level sensor 22 includes a hydraulic distributor valve 50 which is mounted in a fixed position within the collection tank 4. The distributor valve has an inlet port 51 supplied with water pressure e.g. from the head of water in the storage tank 42, a vent port 52 which may discharge directly into the tank 4, a low-level signal port 53 connected to one limb of a twin hydraulic control pipe 23, and a high-level signal port 54 connected to the other limb of the control pipe. The valve 50 is operated by a coarse-threaded control screw 55 which carries a float 56. The float is vertically movable and is non-rotatably engaged with the screw thread by a guide rod 57 which slides within a bracket 58 fixed with the valve 50. (Alternatively the guide rod may be fixed, sliding within a guide aperture in the float.) To ensure smooth operation of the distributor valve it is preferred that the float co-operates with detents on the control screw 55 (e.g. frictional, sprung ball or sprung pawl detents) so that the float is held at its upper and lower extremities until the water level has changed significantly.

The control valve 35 has an inlet port 60 connected to the exhaust port of the pump 34 and contains a valve member 61 which closes against a seat 62 to prevent the flow from reaching an outlet port 63. A stem 64 of the valve member sealingly passes through an internal wall 65 into a control chamber 66 where it is engaged with a diaphragm 67. The space above the diaphragm is connected via a first signal port 68 and the first limb of the control pipe 23 to the low-level signal port 53, while the space below the diaphragm is connected via a second signal port 69 and the second limb of the control pipe to the high-level signal port 54.

When the float 56 of the level sensor 22 is at its lower detent position the inlet pressure at port 51 is applied to the low-level port 53 and thence to the space above the diaphragm 67. The applied pressure causes the valve member 61 to close off the flow from the exhaust outlet of the pump 34, shutting down the pump. When, following the first flush, there is a new inflow of water to tank 4 and the float 56 rises to the upper detent position as shown in Fig. 4, the pressure at port 51 is applied via the high-level port 54 and second port 69 to the space 70 below the diaphragm 67. This causes the valve member 61 to lift off the seat 62 and opens the exhaust outlet of the pump so that the pump immediately begins to operate at full output. At both detent positions of the float the non-pressurised ports 53/54 of the distributor valve are vented via port 52 so that maximum pressure differential is always maintained across the diaphragm 67.

Although one objective is to reduce overall energy consumption, in the present water distribution systems the possibility of including a small electric pump (possibly solar powered) is not precluded, e.g. connected in the delivery line of the hydraulic pump 34.

Due to the efficiency enhancement measures incorporated in the present delivery systems they may typically be capable of recovering and re-distributing at least 60% of the available grey water using hydraulic power only. They also have the advantage of being easy to install and low maintenance with few wearing parts.

Although the above examples concern the collection of surface water the system can be used for collecting and re-distributing water from any suitable source. For example, in a water treatment plant used water can be collected and re-used for various purposes such as tank flushing, vehicle or plant cleaning, screen washing, or agricultural irrigation for example. A hydraulically-operated motor can be used to cyclically supply a number of different zones in turn.

Whilst the above description places emphasis on the areas which are believed to be new and addresses specific problems which have been identified, it is intended that the features disclosed herein may be used in any combination which is capable of providing a new and useful advance in the art.