GB2493699A

GB2493699A - Sea-borne water collector

Info

Publication number: GB2493699A
Application number: GB1113646.2A
Authority: GB
Inventors: Abdulla Alshehi
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-06
Filing date: 2011-08-06
Publication date: 2013-02-20
Anticipated expiration: 2031-08-06
Also published as: GB2493699B; GB201113646D0

Abstract

This invention relates to apparatus 10 and methods for collection of airborne moisture such as rain water, dew or mist over bodies of water such as the sea or lakes. The apparatus is adapted to float on a body of water and comprises a collector 12 having an outer perimeter and an outlet and an immersible storage tank 14. A fluid connection means 16 forms a fluidic pathway between the outlet and an inlet to the storage tank, and a means to withdraw water from the tank. The apparatus may comprise a control means (computer) and one or more sensors which operate a valve which prevents contamination of the storage tank. The collector may be formed from flexible material supported by rigid supports (80 figure 5a). The apparatus may be anchored to the sea bed by cables (70 figure 4a) and by cables and anchors (74 figure 4b) in deeper water.

Description

Sea-borne water collector

Field of the Invention

This invention relates to apparatus and methods for coflection of water. In particular it relates to collection of rainwater over bodies of water such as the sea or lakes. In some embodiments the invention relates to collection of water from dew or mist.

Background of the Invention

Fresh water is an increasingly scarce and valuable resource. The US EPA states "Rainwater harvesting is viewed by many, including the EPA, as a partial solution to the problems posed by water scarcity: droughts and desertification, erosion from runoff, over-reliance on depleted aquifers, and the costs of new irrigation, diversion, and water treatment facilities." "Harvested rainwater in the U.S. is used mostly for irrigation; however, there is a growing interest in using rainwater for drinking and other indoor uses. Over 50% of household water is used indoors; bringing rain indoors could save the expense and environmental costs of treating and transporting water." While rainwater collection on a small scale for local use is well known, larger scale rainwater collection apparatus and methods are only recently being developed. A problem with rainwater collection is the relatively large capture area that is needed, especially in areas of relatively lower rainfall, and the availability of land area for rainwater capture.

Rainwater capture over areas of water such as the sea and lakes has not previously been considered as a means for water supply, except for small scale provision for emergency situations at sea. The present invention aims to provide improved apparatus and methods for rainwater capture that are adapted for use at sea, either in deep water or inshore, or over other bodies of water such as lakes, swamp and estuarine rivers where the body of water may not be usable as a supply in itself. In the following, reference will be made to application at sea, and the surrounding water being seawater, with other possible locations such as those above being understood.

Prior Art

The waterfull' apparatus designed by Adital Ela: (http:I/www.aditalela.com/planet en.asp) (http://www.desiqnophy.com/article/des ign-article-1 00000011 6-design-for-sustainable-prosperity.htm), (both accessed 71h July 2011), provides a rainwater and dew collection system comprising a collector in the form of an upturned umbrella, feeding into a storage tank from which water can be dispensed. The system is designed for use on land, for example in arid regions, and is sized so as to collect 450 litres of water and to provide shade for people underneath the umbrella -so having a typical dimension of approx.

2m above ground level and a typical dimension of the collector of 3m. The collector is formed from a stretched fabric and the system is adapted to collect water from dew or mist by means of choice of appropriate fabric. The system is unsuitable for use over a body of water.

Summary of the Invention

According to the present invention there is provided an apparatus is adapted to collect airborne moisture, such as rainwater or dew, is adapted to float on a body of water, comprises: a collector having an outer perimeter and an outlet, an immersible storage tank, a fluid connection means forming a fluidic pathway between the outlet and an inlet to the storage tank, and means to withdraw water from the tank.

Preferably the apparatus comprises a collector mounted on the tank, the whole being adapted to float at a depth in water such that the perimeter of the collector is a given height or range of heights above the external water level.

In alternative embodiments the apparatus may be adapted to rest on the bed of the body of water, and may be sized so as to keep the co!lector above the external water level.

The apparatus is preferably adapted to resist capture of water splashed or sprayed from the surface of the surrounding water, and the perimeter of the collector may be shaped so as to reduce splash or spray into the collector.

The collector may be permanently connected to the tank by means of the fluidic connection, or may be detachable from it, for example for emptying or cleaning of either component. The collector may be permanently mounted on the tank, or may be removable. The apparatus may be adapted so that rainwater flows from the collector to the tank under gravity. Alternatively, a pump may be provided to pump water from the collector to the tank.

Preferably the apparatus is adapted to float in water in the manner of a buoy.

The apparatus may comprise a storage tank shaped to follow with surrounding wave motion, or shaped largely to resist rocking movement, after the manner of a discus or spar buoy respectively. The storage tank has a volume chosen using one or more of the following Griteria: mean rainfall, required mean time between emptying of the tank, stability in the wave motion expected in the area, ease of fabrication, transport and installation.

In typical situations the annual rainfall will be such that the collector preferably has a characteristic dimension across its width greater than the width of the tank, the tank having a vertical dimension chosen using one or more of the following criteria: storage volume, stability in the wave motion expected in the area, ease of fabrication, transport and installation.

In preferred embodiments the apparatus comprises a breather means allowing air to leave the tank as rainwater enters it, or air to enter as water is emptied from the tank. Alternatively where the amount of water entering the collector is small air is vented from the collector itself, so a breather is not always required. The breather is preferably located at or near the top of the tank and may comprise a breather valve as known in the art that allows air to flow but not water. Alternatively the breather may be a shaped fluidic pathway adapted substantially to prevent water from entering the tank while allowing either water or air to exit from inside the tank, such as a narrow tube. The tank may be fitted with an overflow so that water may exit when the tank is full. In a simple embodiment the tank may be emptied by means of a pipe placed temporarily through the fluidic connection via the outlet from the collector. The collector may be capable of being disconnected from the tank for this purpose. In preferred embodiments the tank comprises an outlet pipe originating in a lower region of the tank so as to achieve effective emptying.

Preferably the apparatus comprises a valve controlhng the fluid pathway between the collector and the tank, the valve being adapted to close the pathway when there is a risk of contamination of the tank contents with seawater. In preferred embodiments the valve acts in response to a stimulus associated with increased risk of contamination, such as movement, e.g. rocking of the apparatus, or wind speed.

Such action may be mechanically actuated, for example by means of a mechanism that closes the valve when a certain degree of tilt or rocking is reached.

In particularly preferred embodiments the apparatus comprises a control means that operates the valve and one or more sensors, the control means being adapted to control the valve in response to a signal from the sensor(s).

In preferred embodiments, one or more sensors are provided from the following: accelerometers, tilt sensors, shock sensors, anemometers, wave height sensors such as GPS-based wave height detection systems, meteorological weather warning systems, rainfall sensors. In preferred embodiments the apparatus comprises a power source, such as batteries, solar cells, a wave or wind driven generator. Particularly preferred embodiments comprise batteries and solar panels.

Preferred embodiments comprise RF communication means, for example GPS, satellite or RF telemetry systems and are adapted to communicate their operational status to a base station.

In particularly preferred embodiments the apparatus is provided with means to vent water from the collector without it passing into the tank. Preferably the apparatus comprises valve means to allow venting, controlled by the control means. In a preferred embodiment a three-way valve is provided which allows water from the collector either to be held in the collector, passed to the tank or vented. Such venting is useful in cases where seawater may have entered the collector, e.g. through spray or waves, and the collector needs to be emptied before collection can re-start.

In further embodiments one or more sensors are provided that sense a condition in the water collected by the collector. Preferably a sensor is provided contacting the water adjacent to the outlet from the collector, the output from the sensor being used by the control means to control operation of the valve(s). Such sensors may be conductivity sensors, salt water sensors, pH sensors, turbidity sensors. In a particularly preferred embodiment a conductivity sensor measures the salt content of water in the outlet from the collector, and the control means acts to allow water into the tank only if it is acceptably free from saltwater contamination.

The apparatus preferably comprises a control means having a memory means and operated by a control program that receives data from one or more sensors forming part of the apparatus or from external signals such as command signals or weather information signals, and controls operation of the valve(s) forming part of the fluid pathway from the collector to the tank and/or vent outlet. The control program may comprise an algorithm that uses sensor signals and other data to determine the risk of seawater entering the collector and so controlling the valve(s) in advance of likely contaminating events, such as high winds leading to spray, or large waves. The control program may also monitor operation of the apparatus, such as the operation of valves, the amount of water collected in the tank, the amount of rainfall in a period of time1 and store and/or communicate data to a remote station.

The apparatus may be designed along similar principles to standard buoys, the design taking account of the variable load of rainwater within the tank.

Alternative embodiments may be adapted to rest on the bed of a shallow body of water. The apparatus may be moored as known in the art, and may be co-operable with a remote storage tank, interconnected by means of pipes. The storage tank may float, or may rest on the seabed and the apparatus may float at the surface. More than one such apparatus may connect to a common storage tank.

A number of apparatus may be linked together and be handled, towed or installed as group. The apparatus may be designed with a chosen buoyancy taking account of the increasing mass of the apparatus as water is collected.

The apparatus may comprise means to control or change its buoyancy, for example comprising one or more ballast tanks that may be filled or emptied.

The apparatus may comprise means to fill and empty a ballast tank, for example a pump and fluidic connections to allow filling with seawater. The apparatus may further comprise a control means adapted to control the buoyancy and one or more sensors that respond to one or more of: the stability of the apparatus as measured by its movement in the sea, the amount of water within the tank, wind speed, wave height.

The size of the apparatus, the area of the collector and the volume of the storage tank may be chosen so as to allow filling over a suitable period of time. Typically the collector will have a large area compared with the horizontal cross-sectional area of the tank. For example, for a region with moderate rainfall of 50cm pa., a 25m2 collector (e.g. a 5m x 5m inverted pyramid) will fill a tank of 12.5 m3 in one year therefore a tank say 2.5m square and 2m deep will fill in a year. The dimensions of the apparatus may depend on the intended application. In preferred embodiments dimensions of the collector are between im and lOOm across, and in more preferred embodiments between 3m and 50m. In alternative embodiments the collector may take an extended form, and may comprise structures over lOOm across.

The collector may take a variety of forms according to the size of the apparatus and conditions in the proposed location. In preferred embodiments the collector is formed from a rigid material, such as metal or plastic, and may be in the form of a largely self-supporting dish, pyramid or cone, with an outlet at the lowest point. In alternative embodiments the collector may be formed from a flexible material such a plastic sheet or woven fabric, supported for example by semi-rigid components such as spars, ribs or poles in the manner of an umbrella or an inverted tent. The material may be tensioned by cables andlor rigid members as known in the art of flexible buildings. In this way large, light collectors may be formed using economical materials.

The apparatus may be adapted for collection of water from dew or mist in the air, and in such embodiments the material of the collector is chosen to have this capability. Such dew-collecting materials are known, for example see the Waterfull' system as referenced under prior art above.

The apparatus may be adapted in some embodiments for rainfall collection for a small group of people, for example a family or village, and may have a typical dimension across the collector of between lm and 5m. The collector in such an embodiment may have any practical shape, for example an inverted cone or dish. The tank may be for example largely cylindrical, pear shaped, or an ovoid, and is may be sized to contain rainwater falling over a period of 1 month, up to 12 months1 or more than 12 months, or to have a chosen volume, such as 0.2-1 m3, 1-2 m3, or over 5 m3. In further embodiments the apparatus may be adapted to collect a large volume of water and may be part of a large installation of similar collectors adapted to provide water for a large number of people, a community or town. In such embodiments the apparatus may have a collector with a typical dimension across the collector of 5 -25m, of up to lOOm, or greater than lOOm. Such large collector dimensions may be achieved by means of using tensioned fabric or plastic sheet structures as described previously. Tank volumes may be in the range less than 10m3, 10 -100 m3, or greater than 100 ri'3. In alternative embodiments more than one apparatus may be used in groups or farms' or in the form of a tessellated hexagonal array, as shown in Figure 10, to harvest rainwater over an extended area, The apparatus may be moored separately or may be connected one to another, or may have components that interfere with one another, so linking the apparatus in the manner of components of a flexible raft.

Optionally, linkages may comprise water connections allowing more than one tank to be emptied using a common emptying line via connections between a number of apparatuses. Optionally, linkages may comprise electrical connections allowing data or control signals to be communicated between apparatus, for example from a control station to a number of apparatus simultaneously. In some embodiments a single collector may be mounted on and supported by a number of separate floatation devices, one or more of the floatation devices having a flexible connection between it and the collector, so allowing the collector to ride over a sea having waves with a wavelength shorter than the typical dimension of the collector, the flexible linkage allowing movement of the individual floatation devices relative to the body of the collector.

The apparatus is preferably adapted for ease of transport and handling and storage, including when on land. Preferably features are provided as part of the apparatus that allow it to stand stably on land, as are known for example in the design of buoys. In a preferred embodiment the apparatus is adapted to be stackable so as to reduce the storage footprint of a number of apparatuses. In a preferred embodiment the apparatus is built to the specification of a standard transport container, and preferably comprises a structural frame adapted to allow handling of the apparatus in the manner of a transport container, for example using cranes, ships, vehicles and stacking/loading procedures designed for such containers. In such embodiments, preferably the apparatus is contained within a structural frame that acts to support the components of the apparatus, and also acts to allow handling and stacking of the apparatus.

In further preferred embodiments the apparatus comprises features to reduce the likelihood of contamination of the rainwater with water from the surroundings, for example a splash rim around the edge of the collector to reduce the Ukelihood of seawater entering. In order to reduce the likelihood of sea water contamination, the length of a pipe connecting the collector and the buoy may be increased to exceed maximum wave height, for example 10 - 15m which is the highest wave height recorded. The apparatus optionally may comprise means to wash the interior surface of the collector with fresh water to remove salt-water contamination, and means to vent the wash water from the collector. The wash water may be drawn from the tank and preferably a fluidic system comprising pump means and valve means is provided to deliver water to the surface of the collector to wash the surface.

Optionally means are provided to control the washing process so as to loosen deposits on the surface and then to wash them away.

Optionally the apparatus may comprise cleaning means such as a cleaning agent, for example a detergent, and means to supply the cleaning agent to the collector surface. Optionally the apparatus may comprise wiping means adapted to wipe the interior surface of the collector, for example a brush or wiper blade, in order to clean the surface.

Such washing means are preferably controlled by the control means under the command of a cleaning program foiming part of the control program.

In a further preferred embodiment the apparatus is adapted to collect rainwater in a batch mode, in which a volume of rainwater is collected and tested in order to determine its quality. Based on the test result the volume is either added to the collection tank or vented. In some embodiments rejected water may be saved in a separate tank for cleaning purposes. Testing may be done for example by means of one or more sensors provided as part of the apparatus, signals from the sensors being interpreted by the control means.

In further preferred embodiments the apparatus comprises filtration means to filter the captured rainwater. Preferably the collected water is filtered before it enters the storage tank. The apparatus may comprise filter means within the fluidic path from the collector to the tank. The apparatus may further comprise means to flush the filter, preferably using water from the storage tank. The apparatus may further comprise water purification means, which may be powered by renewable energy supply means forming part of the apparatus as described earlier. The apparatus may comprise more than one storage tank, for example a first tank that acts to hold rainwater as it is collected, and a second tank that acts to hold filtered and/or purified water.

In use the apparatus of the invention is installed in water, for example in an inshore sea location, and left to operate for a period. During operation the apparatus collects rainwater and may operate autonomously under command of the control means, or may be operated remotely. After a period the apparatus may be emptied. Emptying may be for example on shore, the apparatus being brought back to shore; it may be in situ at sea with a pipe connection to shore; it may be in situ at sea with a pipe connection to a ship; it may be in situ at sea with a pipe connection to a further holding tank, for example on the sea bed or floating near to the apparatus. The holding tank may be movable and in some embodiments may be disconnected from one or more apparatus and taken back to shore.

According to another aspect of the invention is provided a method for collection of rainwater over a body of water, comprising the steps of: a) Providing an apparatus according to the invention b) Locating it within a body of water C) Allowing rainwater to collect within the tank d) Collecting rainwater from the tank In preferred embodiments the method may further comprise one or more of the steps of: e) Closing a valve to isolate the tank from the collector to prevent contaminated water (for example seawater) entering the tank fl Opening a vent valve to vent water from the collector to the exterior g) Measuring a condition in the water, for example conductivity, salinity, pH, turbidity h) Controlling the flow of rainwater into the tank using a valve means operated according to the results of a measurement In further preferred embodiments the method may further comprise one or more of the steps of: i) Filtering all or part of the collected rainwater j) Purifying all of part of the collected rainwater The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-Brief Descriøtion of the Drawings Figure la is a cross section of a first embodiment of an apparatus according to the invention Figure lb is a cross section of an alternative version of a first embodiment of an apparatus according to the invention Figure ic is a partial cross section of an alternative version of a first embodiment of an apparatus according to the invention Figure id is a cross section of a first embodiment of an apparatus according to the invention Figure le is a cross section of an alternative version of a first embodiment of an apparatus according to the invention Figure lf is a cross section of an alternative version of a first embodiment of an apparatus according to the invention Figure 2a is a cross section of a further embodiment of an apparatus according to the invention Figure 2b is a cross section of a further embodiment of an apparatus according to the invention Figure 3a is a block diagram of a valve arrangement and a control system forming part of an embodiment of the apparatus.

Figure 3b is a block diagram of a valve arrangement and a control system forming part of a further embodiment of the apparatus.

Figure 3c is a block diagram of a valve arrangement and a control system forming part of a further embodiment of the apparatus.

Figure 4a shows a diagrammatic cross section of an embodiment of the apparatus configured to rest on the bed of the body of water Figure 4b shows a diagrammatic cross section of an embodiment of the apparatus configured to float on the body of water Figure 4c shows a diagrammatic cross section of an embodiment of the apparatus configured to ink to a storage tank Figure 4d shows a diagrammatic cross section of a number of apparatuses according to an embodiment configured to be linked together Figure 5a is a cross section of a further embodiment of an apparatus according to the invention Figure Sb is a cross section of a further embodiment of an apparatus according to the invention Figure 6a is a cross section of a further embodiment of an apparatus according to the invention Figure Gb is a plan view of the embodiment shown in figure 6a Figure 7 is a cross section of a further embodiment of an apparatus according to the invention Figure 8 shows a flow diagram of operations carried out by a control system of an embodiment of the apparatus Figure 9 shows a flow diagram of operations carried out by a control system of a further embodiment of the apparatus and Figures 10 to 14 show diagrammatic and overall views of alternative structures, forms and embodiments

Detailed Description of the Invention

In the following descriptions reference will be made to the apparatus being used at sea, though applications in other bodies of water will be understood.

Figure la shows a first embodiment of an apparatus 10 according to the invention comprising a rainwater collector 12, a storage tank 14 and a fluidic connection 16 between them, the connection 16 being in the form of a pipe or opening from the collector to the tank. The tank 14 is adapted to float in the sea, shown as 18, and may have any suitable form to move with waves so as to minimise the incidence of waves entering the collector or the likelihood of the apparatus to capsize owing to wave or wind. The apparatus may be dimensioned according to the desired capacity of the tank and the amount of rainfall in the intended location.

The collector may be in the range 1-5m, 5-lOm or greater than lOm across.

The tank may have a volume of less than 1m3, 1-10m3 or greater than 10m3.

An example apparatus has a collector of diameter 5m, the tank having a diameter of 2.5m and a height of 2m, though the invention is not limited to these dimensions and the apparatus may be larger or smaller, and have a greater or lesser water storage capacity, then this. The embodiment in figure la may be empties simply by placing a hose or pipe temporarily through the fluidic pathway 16 and pumping out the water 30.

Figure lb shows a further embodiment with parts as numbered in figure la, further comprising a breather 17 that allows air to vent as water enters the tank, and air to enter as water is emptied from the tank. The breather 17 may also be adapted to function as an overflow port. The fluidic connection 16 is in the form of a removable connection 19 that may be detached from the tank in order to introduce a pipe to empty the tank, or to allow a pipe to be connected to a connector 21 provided at the inlet to the tank 14. The collector is shown as mounted on the tank, with support means 28 in the form of struts.

Figure ic shows a detail of a further embodiment in which the tank is provided with an inbuilt pipe 20 for emptying the tank, preferably extending to a low point of the tank to allow efficient emptying.

Figure id shows a further embodiment of an apparatus 10 comprising a rainwater collector 12, a storage tank 14 and a fluidic connection 16 forming a fluidic pathway between them, the connection 16 being in the form of a pipe or opening from the collector to the tank. The apparatus further comprises means 20 to empty the tank, shown in this embodiment as a pipe extending from a low point in the tank to the exterior, preferably closed by a valve 22 and having a connection 24 to allow emptying of the collected water 30 into an external pipe system. The collector is optionally provided with a splash guard 26. The apparatus comprises structural members as appropriate, for example support members 28 for the collector. The apparatus may also comprise stand or stabilising members 32 to support it while on land.

The tank 14 is adapted to float in the sea, shown as 18, and may have any suitable form to move with waves so as to minimise the incidence of waves entering the collector or the likelihood of the apparatus to tilt or capsize owing to wave or wind. The tank may take different forms as known in the design of buoys, as shown for example in figure 1 e -a wide, shallow form similar to that of a discus buoy, adapted to follow wave motion and to be robust to storms, but likely to have large amplitude rocking motions; or as shown in figure if, having an extended form and deeper draught, in the manner of a spar buoy, adapted to reduce rocking motion and instead to move primarily vertically.

The features 32 may be adapted to stabilise or control motion of the apparatus in waves, and extended features 34 may be provided to control the motion of the apparatus for example to provide a low centre of mass.

Figure 2a shows a further embodiment of an apparatus according to the invention, further comprising a valve means 40 in the fluidic pathway 16 from the collector 12 to the tank 14, the valve controlled by a control means 42, powered by a power source 44, for example a battery pack and/or solar power supply, the control means receiving signals from one or more sensors 46, shown here as an anemometer. In use, the sensor readings such as anemometer readings, indicate the likelihood that bad weather or high winds will lead to contamination of the collector inside surface or of rainwater in the collector with seawater, and the control means acts to close the valve 40 to prevent contamination of the contents of the tank.

Figure 2b shows a further embodiment in which the control means and optionally further sensors are contained within an instrument pack 50 mounted on the apparatus, which further comprises solar panels 54 and beacon 52 or other warning means for ships, mounted on a support frame 55.

Figure 3a shows a block diagram of a cOntrol system forming part of an embodiment of the invention. Valve 40 is provided in the fluid pathway 16 between collector 12 and tank 14, under the control of control means 42, powered by power supply 44. One or more sensors 46, for example an anemometer, and 48, for example a tilt sensor, an accelerometer, or a wave height monitor, feed signals to the control means. The control means may also receive and/or send signals via RF communication means 54.

Figure 3b shows a block diagram of a valve and valve control system of a preferred embodiment of the invention, further comprising a vent pathway 62 closed by a vent valve 60, under the control of the control means 42. In operation water 58 collected by the collector may be allowed into the tank 14 if valve 40 is open and valve 60 is closed, or vented to the exterior if valve 40 is closed and valve 60 is open. The control means receives signals from one or more sensors and optional RF communication means and determines whether to accept or vent the water 58. For example, in use the sensors may indicate high winds, with the likelihood that sea spray will contaminate rainwater in the collector; the tilt sensor or accelerometer may indicate high degrees of tilt owing to wind or waves that make waves breaking into the collector more likely, or that the collector may be angled so that spray contamination may be more likely. In high wind or wave conditions the valves may be kept closed to prevent sudden ingress of seawater into the tank, and valve 40 may only be opened when the sensors indicate calm conditions. Any water entering the collector during high wind or wave conditions may be vented by leaving valve 60 open1 or may be collected and a decision to either vent or accept may be made by the control means at a later time. In alternative embodiments a three-way valve may be provided to carry out the functions of valves 40 and 60.

In preferred embodiments the apparatus further comprises one or more sensors 56 in contact with the inner surface of the collector or with the fluid pathway 16 from the collector to the valves 40 and, if present, 60. The sensor is preferably adapted to sense contamination of the collected water 58, for example, salinity (either by means of a sodium ion or chloride ion sensor or by means of conductivity) or turbidity. The control means reads the signal from the one or more sensors 56 and opens valves 40 or 60 accordingly. In this embodiment the method of use water is preferably that a volume 58 of water is collected and analysed by the sensor(s), and then admitted to the tank or vented. Alternatively the sensors may operate in a constant or batch flow mode, continuously or semi-continuously analysing collected water as it flows past the sensor.

Figure 3c shows an embodiment of the apparatus further comprising an inlet valve 64 controlled by the control means 42. The inlet valve allows the fluid pathway 16 from the collector to be closed to isolate the pathway in case of likely contamination e.g. in stormy weather. The apparatus may further comprise a holding volume 66, for example formed within a second tank or a length of pipe, within which water may be held while it is tested for lack of contamination by a sensor 56 as before. If the water within the holding volume is contaminated it may be vented via valve 60, otherwise it may be admitted to the tank via valve 40.

The flow arrangements in figures 3a-3c are adapted to control flow of water from the collector to the tank or vent under gravity. In alternative embodiments of the invention a pump means may be provided to enable flow from the collector to the tank and/or vent channel. Such a pump may be powered by the power source and controlled by the control means, for example in response to signals from one or more sensors 56. It will be understood too that the apparatus may have further sensors located in the fluid pathway leading from the collector or in the tank and in communication with the control means, such as a water level sensor within the tank, a sensor in the collector to warn for example if a wave has broken into the collector rather than rainwater has gradually accumulated.

The apparatus of the invention may be adapted for use in a range of situations at sea or in other bodies of water. Figure 4a shows an apparatus anchored to the bed of a shallow body of water 18 by means of cables 70 and piles 72. Figure 4b shows an apparatus adapted to float in deeper water, moored by cables 70 and anchors 74. Figure 4c shows an apparatus 10 connected to a large holding tank 76 on the seabed by means of a pipe 78 that carries collected rainwater to the holding tank. Holding tank 76 may be provided with emptying means to allow it to be emptied by ship. Figure 4d shows a number of apparatus 10 linked together to form a floating assembly of rainwater collectors, which may for example be towed into place by a ship and optionally towed to shore for emptying.

Figure 5a shows a further embodiment of an apparatus of the invention, in which the collector 12 is formed from an area of flexible or semi-flexible material, supported by one or more rigid supports 80 and one or more flexible supports (e.g. cables) 82, the material optionally having a rigid rim or perimeter 84. Such an embodiment allows for a large area collector formed from a relatively light material that need not be self-supporting. Figure 5b shows an apparatus with more than one collector 12a, 12b, and a common tank 14. The collector may be formed from one or more, large pieces of flexible material, supported by rigid supports 80, 86, in the manner of an inverted tent, with fluidic pathway(s) 16 leading from the low point(s) of the collector to the tank 16. The collectors may be of any practical shape, such as an inverted cone, or they may be elongated and substantially rectangular, in which the fluidic pathway is an elongated slot. The embodiments in figures 5a and 5b made be made large, with a characteristic dimension across or along the collector of up to 5m, up to 5Dm, up to 50Dm, or larger than 500m.

Figure Ga shows a cross-section and figure 6b shows a plan view of a further embodiment in which the apparatus is formed to fit the standard form factor of a shipping container to allow ease of transport and handling. Parts are labelled as before. The apparatus comprises a load-bearing frame 90 adapted to allow handling and stacking of the apparatus by means of the frame. In preferred embodiments all components of the apparatus are contained within the frame to allow for stacking. The apparatus may comprise floatation means 92 that may be either passive, having a constant buoyancy, or may be active, for example having a buoyancy under control of the control means, for example by pumping ballast water into or out from the floatation means.

Figure 7 shows a further embodiment in which the apparatus is adapted to allow washing of the collector for example to flush it of seawater, or to wash spray or dirt from the collector surfaces. The collector 12 is provided with water washing means 100, preferably arranged around and close to the perimeter of the collector so that when water flows through 100 is flows down the collector surface to as to wash away contaminants. The water washing means 100 is supplied by a pipe 102, pump 104 and a pipe 106 or a manifold fluid pathway formed as part of the collector. During washing wash water is vented, for example by three-way valve 64.

Figure 8 shows a flow diagram for operation of a control system of an embodiment of the invention comprising a tank valve and a vent valve operated by a control means, the control means having input(s) from one or more physical condition sensors such as an anemometer, an accelerometer, a tilt sensor or a wave height sensor. The control system preferably comprises the control means and a control program stored within and run by the control means.

The default position of the valves may be with the tank valve open and the vent valve closed, or vice versa. The control means reads the one or more sensors, and uses the data to determine whether there is a risk that water arriving in the collector may be contaminated with sea water. For example, the control means may comprise an algorithm that uses sensor data to determine the value of a probability function f, and if the value of f is greater than a threshold value f(threshold), the control system acts to protect the contents of the tank, and optionally other functions of the apparatus. If f > f(threshold) the control system may close the tank valve and open the vent valve such that any water that enters the collector will be vented. This may be advantageous in use to prevent the collector becoming filled with seawater from waves breaking over the edge of the collector.

The control system may optionally send an alert to a remote station. The control system then reads the sensors again at intervals ti and acts according to the resulting value of f. If f c f(threshold), then the control system closes the vent valve, opens the tank valve and then reads the sensors at an interval t2 to monitor changes in conditions.

Figure 9 shows a flow diagram for operation of a control system of an embodiment of the invention as described for figure 8, the apparatus now comprising an inlet valve, a tank valve and a vent valve operated by a control means, the control means having input from one or more physical condition sensors such as an anemometer, an accelerometer, a tilt sensor or a wave height sensor. The apparatus further comprises a water condition sensor, for example a conductivity sensor 56 as shown in figure 3c, reading the condition of the water in a holding volume between the inlet valve and the tank and vent valves and read by the control means. The default condition of the valves may be with the inlet valve open, the vent valve closed and the tank valve closed, though other default conditions may be chosen, for example to design the system to fail safe on power loss. The control system reads the physical condition sensors and determines the risk of contamination, for example calculating a risk function f as described above.

If there is a risk of contamination, the system may close the inlet valve and read the sensors again at an interval ti. If there is low risk of contamination, the system opens the inlet valve if it is closed, reads the conductivity sensor 56 to sense if the holding volume contains water to the level of the sensor. If not, the system waits, reading the sensors at intervals until the conductivity sensor detects water. At that point, if the water is not contaminated with seawater, indicated by the conductivity C being below a maximum allowed level Cmax, then the tank valve is opened to allow water to enter the tank, then closed; on the other hand if C > Cmax then the water is vented. The system then cycles back to the start of the loop.

It is to be appreciated that these Figures are for illustration purposes only and other configurations are possible.

The invention has been described by way of several embodiments, with modifications and alternatives, but having read and understood this description further embodiments and modifications will be apparent to those skilled in the art. All such embodiments and modifications are intended to fall within the scope of the present invention as defined in the accompanying claims.

Claims

<claim-text>Claims 1. An apparatus is adapted to collect aftborne moisture, such as rainwater or dew, is adapted to float on a body of water, comprises: a collector having an outer perimeter and an outlet, an immersible storage tank; a fluid connection means forming a fluidic pathway between the outlet and an inlet to the storage tank, and means to withdraw water from the tank.</claim-text> <claim-text>2. An apparatus according to claim 1 wherein the collector is mounted on the storage tank and is dimensioned and arranged to capture moisture, the storage tank, in use, being adapted to float in water such that the perimeter of the collector is maintained at a minimum height above the water level.</claim-text> <claim-text>3. An apparatus according to claim 1 wherein the apparatus is adapted to rest on the bed of the body of water, and dimensioned and arranged so that is use the collector is located above the water level.</claim-text> <claim-text>4. An apparatus according to any preceding claim wherein a means is provided to avoid capture of water splashed or sprayed from the surface of the surrounding water.</claim-text> <claim-text>5. An apparatus according to claim 4 wherein the perimeter of the means to avoid capture of water splashed or sprayed is shaped so as to reduce splash or spray into the collector.</claim-text> <claim-text>6. An apparatus according to any preceding claim wherein the collector is connected to the tank by means of a detachable connector.</claim-text> <claim-text>7. An apparatus according to any preceding claim wherein a pump is provided to pump water from the collector to the tank.</claim-text> <claim-text>8. An apparatus according to any preceding claim wherein a storage tank is provided which tank is shaped to follow with surrounding wave motion, or shaped largely to resist rocking movement a An apparatus according to any preceding claim wherein a breather is provided for allowing air to leave the tank as rainwater enters it, or air to enter as water is emptied from the tank and to reduce evaporation of water from the tank- 10. An apparatus according to any preceding claim wherein a valve is adapted to close a pathway when there is a risk of contamination of the tank contents.11. An apparatus according to any preceding claim wherein the apparatus comprises a control means that operates a valve and one or more sensors, the control means being adapted to control the valve in response to a signal from the sensor(s).12. An apparatus according to claim 11 wherein one or more sensors are provided from the following: accelerometers, tilt sensors, shock sensors, anemometers, wave height sensors such as GPS-based wave height detection systems, meteorological weather warning systems and humidity.13. An apparatus according to any preceding claim includes a power source, such as batteries, solar cells, a wave or wind driven generator.14. An apparatus according to any preceding claim includes a communication means, for example a OPS, satellite or a telemetry system, adapted to communicate to a base station.15. An apparatus according to any preceding claim includes a three-way valve is provided which allows water from the collector either to be held in the collector, passed to the tank or vented.16. An apparatus according to any preceding claim includes a sensor which in use contacts water in the collector and provides a signal to control the operation of one or more valve(s).17. An apparatus according to claim 16 wherein the sensor senses at least one of: conductivity, salinity, pH sensors and turbidity.18. An apparatus according to any preceding claim includes: a control means having a memory means, the control means operates in accordance with a computer program that receives data from said at last one sensor.19. An apparatus according to claim 18 wherein the control program includes an algorithm that uses sensor signals and other data to determine a risk of seawater entering the collector and so controlling the valve(s) in advance of likely contaminating events, such as high winds or low pressure systems.20. An apparatus according to either claims 18 or 19 wherein the computer program monitors operation of the apparatus, such as the operation of valves, the amount of water collected in the tank, the amount of rainfall in a period of time, and store and/or communicate data to a remote station.21. An apparatus according to any preceding claim a fluid path is provided from the apparatus to a remote storage tank.22. An apparatus according to any preceding claim wherein the apparatus has a means to vary its buoyancy to take account of the increase in mass of the apparatus as water is collected.23. An apparatus according to daim 22 wherein the means to vary the buoyancy includes a means to charge/discharge one or more ballast tanks.24. An apparatus according to any preceding claim wherein a plurality of apparatuses are moored one to another.25. An apparatus according to claim 24 wherein a plurality of apparatuses share a common connection allowing more than one tank to be emptied using the common connection.26. An apparatus according to any preceding claim wherein electrical connections allowing data or control signals to be communicated between apparatus for example from a control station to a number of apparatus simultaneously.27. An apparatus according to any preceding claim wherein the apparatus is adapted to collect water in a batch manner, and a means is provided to test a volume of water in order to determine its quality before transferring water from the reservoir.28. An apparatus according to any preceding claim includes a filtration means.29. An apparatus according to any preceding claim includes a water purifier.30. An apparatus according to any preceding claim wherein the apparatus is adapted to be stackable for storage and transportation.31. A method for collection of rainwater over a body of water, comprising the steps of: providing an apparatus according to any of claims 1 to 30 and locating the apparatus on a body of water; and collecting water from the tank.32. A method for as claimed in claim 31 wherein a valve is closed to isolate the tank from the collector to prevent contaminated water (for example seawater) entering the tank.33. Apparatus substantially as herein described with reference to the Figures.34. A method substantially as herein described with reference to the Figures.Amended claims have been filed as follows;-Claims I. An apparatus adapted to collect airborne moisture, such as rainwater or dew, is adapted to float on a body of water, comprises: a coflector having an outer perimeter and an outlet, an immersible storage tank detachably connected to the collector, a fluid connection means forming a fluidic pathway between the outlet and an inlet to the storage tank, a three-way valve controlling the fluidic pathway operable one way to allow water from the collector to be passed to the tank, a second way to allow water from the collector to be vented, and a third way to hold water in the collector, and means to withdraw water from the tank.
2. An apparatus according to claim 1 wherein the collector is mounted on the storage tank and is dimensioned and arranged to capture moisture, the storage tank, in use, being adapted to float in water such that the perimeter of the collector is maintained at a minimum height above the water level.
3. An apparatus according to claim 1 wherein the apparatus is adapted to rest on the bed of the body of water, and dimensioned and arranged so that in * use the collector is located above the water level.
4. An apparatus according to any preceding claim wherein a means is provided to avoid capture of water splashed or sprayed from the surface of the surrounding water.
5. An apparatus according to claim 4 wherein the perimeter of the means to avoid capture of water splashed or sprayed is shaped so as to reduce splash or spray into the collector.
6. An apparatus according to any preceding claim wherein a pump is provided to pump water from the collector to the tank.
7. An apparatus according to any preceding claim wherein the breather is adapted to allow air or water to leave the tank and prevent water from entering the tank..
8. An apparatus according to any preceding claim wherein the three-way valve is adapted to close the fluidic pathway when there is a risk of contamination of the tank contents.
9. An apparatus according to any preceding claim wherein the apparatus comprises a control means that operates the three-way valve and one or more sensors, the control means being adapted to control the valve in response to a signal from the sensor(s).
10. An apparatus according to claim 9 wherein one or more sensors are provided from the following: accelerometers, tilt sensors, shock sensors, anemometers, wave height sensors such as GPS-based wave height detection systems, meteorological weather warning systems and humidity. ** .* * . .
11. An apparatus according to any preceding claim includes a power fle source, such as batteries, solar cells, a wave or wind driven generator. * *. * C * C.. *12. An apparatus according to any preceding claim includes a communication means, for example a GPS, satellite or a telemetry system, adapted to communicate to a base station.13. An apparatus according to any preceding claim includes a sensor which in use contacts water in the collector and provides a signal to control the operation of one or more valve(s).14. An apparatus according to claim 13 wherein the sensor senses at least one of: conductivity, salinity, pH sensors and turbidity. 3°15. An apparatus according to any preceding claim includes: a control means having a memory means, the control means operates in accordance with a computer program that receives data from said at last one sensor.16. An apparatus according to c)aim 15 wherein the control program includes an algorithm that uses sensor signals and other data to determine a risk of seawater entering the collector and so controlling the valve(s) in advance of likely contaminating events, such as high winds or low pressure systems.I?. An apparatus according to either claims 15 or 16 wherein the computer program monitors operation of the apparatus, such as the operation of valves, the amount of water collected in the tank, the amount of rainfall in a period of time, and store and!or communicate data to a remote station.18. An apparatus according to any preceding claim a fluid path is provided from the apparatus to a remote storage tank. * a a *. I* 19. An apparatus according to any preceding claim wherein the apparatus 4** has a means to vary its buoyancy to take account of the increase in mass of the apparatus as water is collected. * ate a20. An apparatus according to claim 19 wherein the means to vary the buoyancy includes a means to charge/discharge one or more ballast tanks.21. An apparatus according to any preceding claim wherein a plurality of apparatuses are moored one to another.22. An apparatus according to claim 21 wherein a plurality of apparatuses share a common connection allowing more than one tank to be emptied using the common connection.23. An apparatus according to any preceding claim wherein electrical connections allowing data or control signals to be communicated between apparatus for example from a control station to a number of apparatus simultaneously.24. An apparatus according to any preceding claim wherein the apparatus is adapted to collect water in a batch manner, and a means is provided to test a volume of water in order to determine its quality before transferring water from the reservoir.25. An apparatus according to any preceding claim includes a filtration means.26. An apparatus according to any preceding claim includes a water purifier. * . . * S.27. An apparatus according to any preceding claim wherein the apparatus is adapted to be stackable for storage and transportation. S..28. A method for collection of rainwater over a body of water, comprising the steps of: providing an apparatus according to any of claims 1 to 27 and locating the apparatus on a body of water; and collecting water from the tank.29. A method for as claimed in claim 28 wherein a valve is closed to isolate the tank from the collector to prevent contaminated water (for example seawater) entering the tank.30. Apparatus substantially as herein described with reference to the Figures.32. A method substantiaUy as herein described with rejeence to the Figures. S. b * . . * **4**t** * S *. .4 * . S S. SS *5SS * 35 * S 4"S 5*5S</claim-text>