WO2010058171A2

WO2010058171A2 - Water production apparatus and method

Info

Publication number: WO2010058171A2
Application number: PCT/GB2009/002705
Authority: WO
Inventors: Richard Hefford Hobbs; Jason Peter Morehen; Malcolm Bruce Myers
Original assignee: Cambridge Research and Development Ltd
Current assignee: Cambridge Research and Development Ltd
Priority date: 2008-11-19
Filing date: 2009-11-19
Publication date: 2010-05-27
Anticipated expiration: 2011-05-19
Also published as: GB0821174D0; WO2010058171A3; GB2465417A

Abstract

An apparatus for extracting water from air has a housing (10) defining a cavity (30) having an air inlet (20) and an air outlet (60). Filters (70) span both the inlet and the outlet, and the cavity contains a condenser having a hydrophilic surface. The apparatus also includes a means for moving air through the cavity, such as a fan.

Description

Water Production Apparatus and Method

The invention relates in its various aspects to apparatus and methods for extracting water from air, collecting water and maintaining a supply of potable water. The invention is particularly relevant to a machine for generating and dispensing potable water from humid air.

Background

In most normal circumstances atmospheric air contains a proportion of water vapour. We typically refer to this water vapour as humidity. The proportion of water in air can range from a few grams per kilogram of air in dry or cold environments, to 30 to 50 grams of water per kilogram of air in moist, warm environments. It is also well-known that liquid water can be induced to form from humid air by condensation. The concept of utilising the humidity in air to produce potable water for human consumption is not new and there have been many attempts to produce a machine that generates water from air. The potential benefits of such machines are great, particularly in the context of use in parts of the world with unclean, or unreliable, water supplies. Such machines may also be of great benefit in the management of environmental disasters such as earthquakes or flooding, where existing water supplies may be disrupted or contaminated.

As an example, Bangladesh is a country with relatively warm climate and highly humid air. Bangladesh has a plentiful supply of water in terms of river water, but this river water is often contaminated and not suitable for drinking. During the regular floods that occur in Bangladesh, safe drinking supplies may become unavailable or quickly contaminated and many people become ill or die from the results of drinking contaminated water. If machines could be deployed to successfully extract drinking water from the humid air, then lives could be saved in times of natural disaster. In practice, the production of an air to water generating machine for producing and maintaining water for human consumption has proved difficult. Problems exist in the extraction of a sufficient volume of water and in the extraction of water at an economical rate per watt of energy used. Furthermore, particular problems exist in the purification of generated water and the maintenance of potable water. Existing systems quickly succumb to the contamination of water within the machine by bio-slime and black moulds that render the water unpalatable or unsafe for human consumption.

It is an aim of the present invention to address the issues with existing water machines.

Summary of the Invention

The invention provides in its various aspects apparatus and methods for extracting water from air, collecting and purifying water, and purifying and dispensing water according to the appended independent claims to which reference should now be made. Preferred and advantageous features of the invention are defined in dependent sub-claims.

Thus, in a first aspect the invention may provide an apparatus for extracting water from air comprising a housing defining a cavity having an air inlet and air outlet, a condenser disposed within the cavity between the inlet and the outlet (such that air passing through the inlet through the cavity and out of the outlet passes across the condenser). At least a portion of the surface of the condenser comprises a hydrophilic material. The hydrophilic material could be material making up the condenser itself or could be a material coated onto the surface of the condenser.

Preferably the condenser comprises cooling fins that are corrugated or otherwise shaped to increase the surface area of fin, for example "s-fins". There may be one or more fins on the condenser and one or more condensers mounted in the cavity, depending on, among other factors, the volume of air to be passed through the cavity and the amount of cooling required. Any known method of cooling the condenser could be used. For example, the condenser may advantageously be cooled by a pettier cooling means or by a refrigerant gas cooling system.

The apparatus further comprises a filter spanning the air inlet and a filter spanning the air outlet. In addition, the apparatus comprises means for causing air to flow through the cavity, i.e. to flow from the external environment in through the inlet, across the surface of the condenser, and out of the outlet.

Preferably, the apparatus comprises a plurality of inlet filters of different grades. These filters are arranged in series for the efficient filtering of different sizes of airborne particulates and pathogens. Where there are a plurality of filters, the filter with the coarsest grade is preferably arranged to be the outermost filter, i.e. on the external environment side of the inlet. The coarsest grade filter filters out the larger particles of dust, debris and other airborne matter, such as flying insects, from the air. There is then a succession of filters of finer grade for filtering finer particles from the air, with the finest grade filter positioned innermost, i.e. on the cavity side of the inlet. Preferably, the finest filter is a high efficiency particulate air (HEPA) filter.

Advantageously, rather than a plurality of filters of different grades, the apparatus may comprise a single filter for filtering efficiently different sizes of airborne particles. Use of a single filter that accomplishes the filtering efficiently of different size particles may advantageously make the inlet filter simpler and cheaper to exchange when this is required.

Different means may be envisaged for moving air through the inlet, for example bellows-type mechanisms or pumps. Preferably, however, the means for moving air through the inlet is a fan.

Advantageously, a fan may be mounted within the housing where it can act to draw air through the inlet and over the condenser, and drive air out of the apparatus through the air outlet.

The means for moving air may produce a fixed rate of air flow over the condenser. The rate of flow could be set, for example, to produce the optimum amount of condensed water for a particular set of environmental conditions (e.g. air temperature, air humidity, condenser temperature). The means for moving air (e.g. a fan) may advantageously produce an air flow rate that may be varied in response to changes in environmental conditions to maintain an optimal air-flow over the condenser while the air temperature, air humidity, condenser temperature, or other relevant variables change. Thus, the apparatus may comprise a sensor or sensors for monitoring one or more environmental or apparatus parameters. The apparatus may also comprise a controller coupled to the sensor for providing feedback to the air moving means to vary the air flow rate through the apparatus.

A similar feedback system as described above in relation to varying airflow over the condenser could be used to vary the temperature of the condenser in response to changes in certain parameters. Advantageously, both the air flow rate and the condenser temperature can be varied in response to environmental conditions with the aim of producing an optimal yield of water or, alternatively, producing water using minimal power.

Preferably, the cavity comprises an opening for the passage of condensed water away from the condenser. This opening is preferably situated, in use, below the condenser. Thus water condensed on the condenser may drip down under the action of gravity and into the opening to be carried away. A collection tray or funnel may be fitted into such an opening to aid the collection of condensed water.

In a second aspect, the invention may provide an apparatus for collecting and purifying water. This apparatus may comprise a collection member for receiving water, such as a funnel or a tray, in which at least a portion of the collection surface of the collection member comprises a material having biocidal and/or antimicrobial properties. Thus, water entering the collection member may contact biocidal or antimicrobial material and thus any bacterial or microbes within the water at this stage may be neutralised.

The apparatus further comprises a conduit for the passage of received water leading away from the collection member towards a non-return valve. A water filter is disposed in-line in the conduit between the collection member and the non-return valve, and the apparatus further comprises a pump for transporting water from the collection member through the non-return valve.

In use, as water is transported from the collection member it is passed through the water filter and then through the non-return valve. As the water passes through the water filter remaining particles, or particles that have originated within the water machine, may be removed leaving pure water. The water may then simply be dispensed via the non-return valve, for example for use in irrigation or in industry, or may pass into a further portion of the apparatus or a further apparatus for storage.

The water filter preferably contains carbon and may contain or include antimicrobial or anti-bacterial material, for example silver.

Preferably, the conduit is made of a flexible material, for example a silicone rubber pipe or tubing, and preferably the pump is a peristaltic pump that acts on the flexible conduit. Thus, the water passing through the apparatus need not encounter mechanical components of a pump. This is advantageous as it provides fewer internal recesses or nooks in which water may become trapped and stagnate, thereby promoting the growth of bacteria and mould.

A preferable material for use as the biocidal/antimicrobial material is silver. Silver is commonly available and can be easily coated onto the surface of a collection member.

The water filter is preferably a carbon filter for removing particulate matter from the water. In a third aspect, the invention may provide an apparatus for purifying and dispensing water, preferably potable water. This apparatus may comprise a purification zone for purifying water, a dispensing zone for storing and dispensing water, and a circulation system for producing a continuous circulation of water between the purification zone and the dispensing zone.

Any system which has standing water runs the risk of the growth of bio-slime. This is a growth of bacteria which, whilst it may not be hazardous to health in all cases, can add an unpalatable taste to the water. A system with standing water also encourages the growth of black mould which makes the water unsafe. If the water is always moving, i.e. if it is not allowed to settle and stagnate, then the risk of the growth of bio-slime and black mould is reduced.

The purification zone may comprise an antibacterial means such as an ultraviolet radiation source for radiating water with ultraviolet light or any other suitable means of purification Preferably, the purification zone comprises an ozonation device or ozonation chamber. This type of device generates ozone gas, which can be bubbled through the water. A proportion of the ozone is absorbed into the water and acts as an anti-bacterial agent.

A preferable ozonation device comprises a chamber having a water inlet and a water outlet. This chamber houses a proton exchange membrane (PEM) cell for generating bubbles of ozone within the chamber. Ozone generated in this way is absorbed into the water and acts to kill bacteria and microbes. The amount of ozone absorbed into the water is related to the surface area of bubbles generated by the PEM cell; a small number of large bubbles produce a lower area of gas - liquid interface per volume of ozone than a large number of small bubbles. Therefore a preferable ozonation device has a mesh, for example a stainless steel mesh, arranged so that bubbles generated by the PEM cell are disrupted by the mesh. The result of this disruption is that smaller bubbles are produced and this may increase the proportion of ozone absorbed into the water. It is preferable that the ozonation device or the apparatus contains some indicator or switch for determining whether there is sufficient water in the system for the PEM cell to be operated. The PEM cell may suffer damage if operated without being immersed in water, thus the apparatus must either be primed or, if incorporated as part of a water generation machine, the machine is preferably operated for a period of a few minutes prior to operating the ozonation device. It is preferable that a sensor of some type acts to detect the presence of water at the PEM cell before the ozonation device is allowed to operate.

Preferably, the dispensing zone comprises a storage tank having a water inlet for receiving water from the purification zone, a water outlet for returning water to the purification zone, and a dispenser for dispensing water from the tank, for example for drinking.

The dispensed water may be treated in some way to improve the taste of the water. For example, flavourings, essential minerals and salts could be added within the storage tank or within the circulation system. (Such treatments may also be added to the water at an earlier stage in processing). It may be beneficial in some circumstances to add prescribed drugs to the water, for example where a water machine according to one or more aspects of the invention is deployed in a disaster management situation. In certain situations it may be beneficial to elute minerals and salts into the water such that the water dispensed is a diaoralyte that can be used for oral rehydration purposes.

Water may be carbonated before, or during, dispensing. If this is desired a standard carbonation unit could be suitably arranged within the apparatus.

Preferably, the storage tank is shaped such that, in use, there are no horizontal surfaces. This may help, in combination with the water circulation system, prevent the formation of standing or stagnating water. Thus, the tank may have sloping curved sides leading down to a low point at which a water outlet for returning water is situated. Water in the tank is continuously flowing through the outlet at the lowest point of the tank and is, thus, not allowed to become stationary within the tank, but is continually moving.

Preferably the tubing of the circuits are also arranged to minimise the occurrence of flatspots and u-bends.

The storage tank may include a switch to cease production when the tank is full.

The storage tank may be light-tight, so as to inhibit the formation of algal growth.

The storage tank may incorporate a float switch, or some other means for determining water level or volume within the storage tank. The advantage of such means is that the output of the ozonation cell may be tailored to increase with increasing volume in the system. This may allow the volume of ozone produced per volume of water to be maintained as an approximate constant.

The storage tank may also incorporate some visual means for determining water level, for example a window or a light emitting diode (LED) display. It is preferable that the storage tank and circulation system do not contain any materials that react with ozone where a level of ozone is to be maintained in the water.

Advantageously, the apparatus may further comprise a chiller element arranged to cool water so that cooled water may be dispensed. The chiller may be arranged within the circulation system prior to water entering the tank or the dispensing zone, such that the dispensing zone is filled with cooled water, or alternatively the chiller may be situated downstream from a dispenser associated with the dispensing zone so that only dispensed water is cooled.

The circulation system may include a filter, for example a carbon filter. Water within the circulation system would then continually pass through the filter and this may help neutralise any bacterial growth. Such a filter may contain an anti- microbial or anti-bacterial agent, for example silver. Silver particles may oxidize within the system, particularly if ozone is present, however, silver oxide may still provide beneficial antibacterial effects.

In a fourth aspect, the invention may provide an ozonation device for purifying water, comprising a chamber having a water inlet and a water outlet, the chamber housing a proton exchange membrane (PEM) cell for generating bubbles of oxygen within the chamber, and a mesh arranged to disrupt the generated bubbles, thereby producing a plurality of smaller bubbles. This device may advantageously increase the efficiency of ozone absorption into the water as described above.

An ozonation device according to this fourth aspect, or any water machine incorporating such a device, may include a sensor within the PEM cell chamber for ensuring that water is present in the device before the device is switched on. This sensor may be linked to a switching means that prevents operation of the PEM cell unless water is present within the PEM cell chamber.

Although apparatus having features as described in relation to each of these aspects may be separately deployed as part of water generating or water purifying machines with considerable advantage, the aims of the invention may be furthered by the combination of two or more of these aspects in a single water generating machine or system. Thus, a water machine may comprise the combination of the apparatus of the first aspect (an apparatus for extracting water) and the apparatus of the second aspect (an apparatus for collecting and purifying water), or the apparatus of the first aspect and the apparatus of the third aspect (an apparatus for purifying and dispensing water), or the apparatus of the second aspect and the apparatus of the third aspect, or, indeed, a water machine may comprise all three aspects in conjunction in a single machine. Furthermore, an ozonation device according to the fourth aspect may be advantageously incorporated into any water generating machine as described above. Thus, in combination, a water machine may comprise the apparatus of the first aspect to extract water from air, the condensed water from which drips into a collection member of the apparatus of the second aspect of the invention where it is filtered and passed through a non-return valve into the apparatus of the third aspect of the invention where the water is further purified, stored and circulated ready to be dispensed.

In such a system water may pass from the apparatus for circulating and dispensing water through a chiller which is part of the condenser apparatus for extracting water from air. Thus, a single chiller or cooler unit, for example a refrigerant gas cooler or a pettier cooler may act as both a condenser for extracting water from air and a chiller for chilling water for dispensing.

Water generated by a machine or apparatus according to the invention in any of its aspects or combinations may be used in a number of areas. The invention is particularly relevant to the production of potable water for drinking. Drinking water could be produced in third-world countries or other regions where reliable safe water supplies are scarce, or for use in disaster relief situations. Drinking water may also be advantageously produced in office environments, for example as a replacement for existing water coolers that use a supply of bottled water.

Water generated by machines according to one or more aspects of the invention may also be used for non-drinking purposes. For example, such water could be used for irrigation, or in medicine, or for use in industrial processes. Some processes, for example in the chemical industry, require water of high purity. Typically such water is provided by distillation. The use of a water generating machine according to one or more aspects of the invention may be a more efficient way to produce the pure water required.

A potential use of potable water is in vending machines. Drinks such as coffee, tea, and soft drinks dispensed by a vending machine often use a mains supply of water. Such machines cannot be installed in regions without a safe supply of mains water. In addition, the quality and character of water varies considerably from area to area. This results in an inconsistent taste in the dispensed product depending on what the water supply is like in that area. To enable vending machines that use water to produce their product to be installed in regions without safe water supply and to enable such vending machines to produce a consistant tasting product no matter where in the world they are installed, it may be advantageous to incorporate a machine for generating water from humidity in air for use in the vended product instead of mains water.

Thus, in a still further aspect the invention provides a vending machine incorporating an apparatus for generating water from humidity in air. While any apparatus for generating water from air could be used in a vending machine, preferably the apparatus incorporates apparatus according to one or more of the aspects described herein.

A specific embodiment of the invention will now be described with reference to the drawings in which:

Figure 1 is a schematic illustration of an apparatus for extracting water from air according to a first aspect of the invention;

Figure 2 illustrates a front projection of a water machine incorporating various aspects of the invention;

Figure 3 is a rear projection of the water machine of figure 2;

Figure 4 is an expanded schematic diagram illustrating elements of the water machine according to various aspects of the invention;

Figure 5 illustrates an ozonation device according to an aspect of the invention;

Figure 6 Is a graph showing water production rates under different conditions for the water machine illustrated in figure 2. An exemplary water generating machine (figures 2 and 3) comprises a water extraction apparatus (also illustrated separately in figure 1), a water purification apparatus and a water storage and dispensing apparatus (both illustrated schematically in figure 4).

Thus, a water extraction apparatus for a water generating machine according to various aspects of the invention comprises a housing 10 defining an air inlet 20 leading into a cavity 30. A condenser 40 is mounted within the cavity 30. Also mounted within the cavity 30 is a fan 50 operable to draw air in through the air inlet 20 across the condenser 40 and out of an air outlet 60.

In use, air is passed across the condenser by the fan (the fan 50 produces an air flow of 230 cubic feet per minute through the cavity 30) and water vapour carried by the air is caused to condense into liquid water at the condenser, which is maintained at a lower temperature than the air. The condenser 40 is coated with a hydrophilic lacquer (comital lacquer (ATS) bleu) which interacts with condensation of atmospheric humidity on the condenser causing an increased superficial tension creating a thin surface liquid film of uniformly spaced microscopic drops instead of the usual coarse drop aggregation, thus improving the thermo-unit efficiency.

The condenser is cooled by a standard vapour-compression refrigeration system. Compression of the refrigerant gas is achieved by means of a compressor 45.

The air inlet is spanned by a series of four filters of differing grades for removing airborne particles prior to air reaching the condenser. The filter pack 70 comprises a first inlet filter 71 (Jasun filtration G3 medium air filter) for removing large particles such as brick dust, a second inlet filter 72 (Jasun filtration G4 medium air filter), a third inlet filter 73 (Jasun filtration F6/F7 fine air filter), and a fourth inlet filter 74 for filtering microscopic pathogens (Jasun filtration F8/F9 fine air filter). It should be clear that the filters may be any suitable filter for removing airborne particulates and the invention is not limited to the specific filters mentioned above. Furthermore, rather than being two or three or four separate filter elements arranged in series, a single filter could conveniently be used providing the filter efficiently removes a large proportion of airborne particulates.

The air outlet leading from the cavity is also spanned by a filter or filters 75. This exhaust filter acts as a guard against particles being drawn in from the external environment when the fan is not in operation (for example when the water tank is full and a cut-off switch has halted water extraction). The fan may also help prevent accidental injury by the fan when it is in operation by preventing fingers from easily reaching the moving fan.

Water droplets forming on the condenser drip, under the action of gravity, through an opening in the cavity 30, and into a collection tray 100. This tray forms part of a water purification apparatus according to an aspect of the invention incorporated into the water generation machine. The tray is formed from stainless steel and coated with silver, and water dripping from the condenser into the tray runs across the silver collection surface of the tray towards a water outlet 110. A section of dairy-grade silicone rubber tubing leads from the water outlet to a carbon water filter 130 and another section of tubing leads from the filter 130 to a non-return valve 140. The tubing used in the presently described embodiment is Versilic™ hose from RS Components. Versilic™ is a biologically inert flexible tubing. Any similar biologically inert tubing material may be used for the present invention.

In use, a first peristaltic pump 150 acts on the outer wall of the tubing to drive water from the collection tray through the carbon filter and through the nonreturn valve. The peristaltic pumps in the presently described embodiment are Etatron peristaltic pumps which fit around the silicone tubing and provide a constant flow rate by peristaltic action.

Beyond the non-return valve further silicone tubing 120 leads to an ozonation cell 160 from the ozonation cell into an inlet 170 of a storage tank 180. These components form part of a water storage and dispensing apparatus incorporated into the water generation machine. The storage tank in the present example has a capacity of 15 litres, but increasing the capacity of the tank is a matter of mere engineering choice. A number of storage tanks may also be joined in series to store a larger volume of water.

The storage tank 180 is designed to have, in use, no horizontal surfaces and thus presents various surfaces that slope down to a water outlet 190 at the lowest point of the storage tank. The storage tank also has a dispensing outlet 200 disposed vertically above the water outlet 190. Silicone tubing leads from the storage tank water outlet 190 through a second non-return valve 210, and from here the water is returned back through a T-junction 220 to the ozonation cell.

In use, water is maintained flowing in this circuit between the storage tank and ozonation cell by means of a second peristaltic pump 230. Water passing out of the storage tank through dispensing outlet 200 may directly pass to a user through, for example, a tap, or may pass through a chiller unit to deliver cool water to a user. The chiller unit may be linked with the water condenser 40 and may make use of the same cooling mechanism.

Figure 5 illustrates the ozonation cell as mentioned above in more detail. The cell has a housing 300 defining a chamber 310 that may be flooded with water. A water inlet 320 allows water into the chamber 310 and water outlet 330 allows purified water to pass out of the chamber. A proton exchange membrane cell (not shown) is mounted within the chamber and operates to produce bubbles of ozone within the chamber. These bubbles of ozone rise through the water and interact with mesh 340. On interaction with the mesh the bubbles produced are disrupted and a plurality of finer bubbles are produced in the water. These finer bubbles improve the efficiency of ozone dissolution within the water in the device.

The water generating machine described above essentially acts as a large dehumidifier. If there is not much water vapour in the atmosphere, then the water machine can only produce small quantities of water in a given period of time. Preferably, for efficient operation, the operational humidity is greater than 20%.

In tests a water machine as described above was operated under various conditions in an environmental chamber to determine water production rates and electricity costs. The graph shown in figure 6 illustrates water production rates at different relative humidities. The amount of water in air is given by relative humidity (RH), which is a percentage. For any given temperature, RH of 70% denotes more water vapour in the atmosphere than RH of 30%. As RH is temperature-dependent, there is more water vapour in the air at an RH of 70% and 30°C than an RH of 70% and 20⁰C. For production rates to be high and electricity costs per litre to be low, the water machine would ideally operate in a warm humid atmosphere. The machine will still function at low temperatures and in dry environments, but production rates will be correspondingly lower and electricity costs per litre will be higher. Practically it is preferred that the machine can operate in conditions producing between 500 ml to 2000 ml of water per hour. Given a typical power consumption of the machine of 1 kW, the cost at low production rates is approximately 2 kW hours per litre, and this decreases to around about 0.5 kW hours per litre for high production rates (i.e. warm humid conditions).

As the water machine is intended to be used in a number of different environments, the electricity supply used may advantageously derive from solar panels or from wind power or some other such renewable power source. Alternatively the use of a generator may be appropriate to produce the power for water production, or in, for example, office or home use the machine may be powered by a mains electricity supply.

The water machine may have a switch to cease production when the storage tank is full. Alternatively, a number of storage tanks could be linked in series such that there is a continuous flow of water through a number of separate storage tanks. In this situation there may also be a plurality of purification devices located between the storage tanks so that the water is cycled through a purification device on a frequent basis.

The specific water machine described above produces fairly low volumes of water. It is clear, however, that the person skilled in the art would be able to scale up the device to produce large quantities of water, for example by having a plurality of condenser units or larger condenser units etc.

Claims

1. An apparatus for extracting water from air comprising, a housing defining a cavity having an air inlet and an air outlet, a condenser disposed within the cavity between the inlet and the outlet, at least a portion of the surface of the condenser comprising a hydrophilic material, an inlet filter spanning the air inlet, and an outlet filter spanning the air outlet, the apparatus comprising means for moving air through the cavity.

2. An apparatus according to claim 1 comprising a plurality of inlet filters of different grades arranged in series for filtering different sizes of particles, the filters arranged with the coarsest grade outermost and the finest grade innermost.

3. An apparatus according to claim 1 or 2 in which the means for moving air through the cavity is a fan.

4. An apparatus according to claim 3 in which the fan is mounted within the housing and draws air over the condenser.

5. An apparatus according to any preceding claim further defining an opening for the passage of condensed water away from the condenser.

6. An apparatus for collecting and purifying water comprising, a collection member for receiving water, at least a portion of the collection surface of the collection member comprising a material having biocidal and/or antimicrobial properties, a conduit for the passage of received water leading from the collection member to a non-return valve, a water filter disposed in-line between the collection member and the non-return valve, and a pump for transporting water from the collection member through the non-return valve.

7. An apparatus according to claim 6 in which the conduit is made of a flexible material and the pump is a peristaltic pump.

8. An apparatus according to claim 6 or 7 in which the biocidal / antimicrobial material is silver.

9. An apparatus according to claim 8 in which the collection surface of the collection member is coated with silver.

10. An apparatus according to claim 6, 7, or 8 in which the filter is a carbon filter.

11. An apparatus for purifying and dispensing potable water comprising; a purification zone for purifying water, a dispensing zone for dispensing water, a circulation system for producing a continuous circulation of water between the purification zone and the dispensing zone.

12. An apparatus according to claim 10 in which the purification zone comprises an ozonation device.

13. An apparatus according to claim 12 in which the ozonation device comprises a chamber having a water inlet and a water outlet , the chamber housing a proton exchange membrane (PEM) cell for generating bubbles of ozone within the chamber and a mesh arranged to disrupt the generated bubbles thereby producing a plurality of smaller bubbles.

14. An apparatus according to claim 11 or 12 in which the dispensing zone comprises a storage tank having a water inlet for receiving water from the purification zone, a water outlet for returning water to the purification zone and a dispenser for dispensing water from the tank for use.

15. An apparatus according to claim 13 in which the storage tank is shaped such that there are no horizontal surfaces to prevent standing water formation.

16. An apparatus according to claim 14 in which the water outlet is positioned at the lowest point of the storage tank.

17. An apparatus according to any of claims 11 to 15 further comprising a chiller arranged to cool the water so that cooled water may be dispensed.

18. An ozonation device for purifying water comprising a chamber having a water inlet and a water outlet , the chamber housing a proton exchange membrane (PEM) cell for generating bubbles of ozone within the chamber and a mesh arranged to disrupt the generated bubbles thereby producing a plurality of smaller bubbles.

19. A water generating machine comprising at least one of the apparatus for extracting water from air defined by claims 1 to 5, the apparatus for collecting and purifying water defined by claims 6 to 10 and the apparatus for purifying and dispensing water defined by claims 11 to 17.

20. A method of extracting water from air comprising the steps of; causing air to move through a filter into a cavity, causing air to move over a condenser, and causing air to move out of the cavity through a filter wherein the portion of the surface of a condenser comprises a hydrophilic material aiding the condensation of water vapour carried in the air, and allowing condensed water to pass out of the cavity.

21. A method according to claim 20 in which the air is moved through the filter into the cavity across the condenser and out of the cavity by means of a fan mounted within the cavity.

22. A method for collecting and purifying water comprising the steps of, receiving water in a collection member, at least a portion of the collection surface of the collection of the collection member comprising a material having biocidal and/or antimicrobial properties, transporting collected water through a water filter, and transporting collected water through a non-return valve.

23. A method according to claim 22 in which water is transported by means of a peristaltic pump.

24. A method for purifying and dispensing possible water comprising, passing water through a purification zone, passing water into a dispensing zone, and continuously circulating water between the purification zone and the dispensing zone.

25. A method according to claim 24 in which the purification zone comprises an ozonation device.

26. A method according to claim 25 comprising the steps of, forming bubbles of ozone within an ozonation chamber, and passing generated bubbles through a mesh to produce smaller bubbles.

27. A vending machine for dispensing a product, comprising an apparatus for extracting water from air, the water generated being used in the preparation of the product.

28. A vending machine according to claim 27in which the apparatus for extracting water from air is a water generating machine according to claim 19.

29. An apparatus for extracting water substantially as defined herein and with reference to the drawings.

30. An apparatus for collecting and purifying water substantially as described herein and with reference to the drawings.

31. An apparatus for purifying and dispensing potable water substantially as defined herein and with reference to the drawings.

32. An ozonation device for purifying water substantially as described herein and with reference to the drawings.

33. A water machine for extracting water from air substantially as described herein and with reference to the drawings.