Abstract:
A number of apparatii for condensing water from the atmosphere are described, whereby atmospheric air is drawn through an enclosed space and moisture condenses on plates or similar contained within the enclosed space and subsequently collected. Most of the apparatii include means to increase the flow of air through the enclosed space to increase the efficiency of moisture collection. A typical apparatus includes a body ( 11 ) supporting condenser plates ( 15 ) of conical or frusto-conical configuration. Extractor fans, the operation of which are controlled by humidity sensing switches and temperature sensors, provide the increased flow. To promote condensation, typically, cooling ducts ( 49 ) are provided through which air-conditioned cool air is passed.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to a method and apparatus for collecting moisture from the atmosphere.  
       BACKGROUND ART  
       [0002]     Water for communities is generally provided by means of large scale reticulation systems where water is collected in dams and distributed to users. Alternatively, users can themselves provide for water collection by means of tanks which collect water off roofs or other surfaces. Because of changing climatic conditions however, the reliability of conventional water supplies is lessening with the result that, in many communities, water restrictions are in place which limit the volumes of water which can be used or the manner of water use.  
         [0003]     It is known that large quantities of water are contained in the atmosphere measured by humidity and various condensation systems in the past have been proposed for recovering water from the atmosphere. The systems which have been proposed however have not proved to be particularly efficient.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention thus aims to provide improved methods and means for collecting water from the atmosphere. Other objects and advantages of the invention will become apparent from the following description.  
         [0005]     The present invention thus provides in one preferred aspect a method of collecting water from the atmosphere, said method including: 
        arranging in an enclosed space a plurality of condenser members upon which moisture can condense;     exposing said enclosed space to said atmosphere;     providing flow means for increasing flow of air from said atmosphere through said enclosed space such that moisture in said atmosphere will condense upon said condenser members; and     providing collection means for collecting thus condensed said moisture.        
 
         [0010]     The present invention provides in a further preferred aspect an apparatus for collecting water from the atmosphere, said apparatus including: 
        a body defining an enclosed space;     a plurality of downwardly angled condenser members within said enclosed space upon which moisture can condense, said enclosed space communicating with said atmosphere;     flow means for increasing flow of air from said atmosphere through said enclosed space; and     collection means for collecting thus condensed said moisture.        
 
         [0015]     In a first form, the flow means for increasing air throughput is provided by an air exhaust extraction system. Suitably, the air exhaust extraction is undertaken at or near the base of the apparatus. Preferably the air exhaust extraction system includes one or more extractor fans. In isolated locations, the extractor fan/s may be powered directly by solar cells or from batteries charged by solar cells. Alternatively, where available, mains power may be used for driving the extractor fan/s.  
         [0016]     Preferably, control means are provided to maximise air throughput as the humidity decreases. Such control means may function automatically and may comprise one or more humidity control switches which switch in one or more extractor fans as the humidity decreases. The control means may also be associated with temperature sensing means such that hot air is not passed through the system thereby reducing efficiency of operation of the condenser members.  
         [0017]     Circulation means may also be provided for circulating cold air about or inside the apparatus. Cold air may be provided by an air-conditioning unit or other cold air source. Suitably, cold air is provided through a closed circuit system. The closed circuit system may comprise air ducts. The air ducts may be provided with heat exchange means to maximise heat transfer. The heat exchange means may comprise fine associated with the ducts. The circulation means may also be powered by solar cells or mains power.  
         [0018]     Other means may also be provided to maximise flow of air. Such means may include a pressure means to alter pressure within the apparatus to increase air flow. Such pressure means may be a venture.  
         [0019]     The body of the apparatus may comprise a tank-like structure arranged in an upright configuration. In a further form, the enclosed space may be defined by an inclined body such that condensed water flows towards the lowermost end of the body for collection.  
         [0020]     The condenser members may be arranged in any suitable orientation within the enclosed space. In one form, the condenser members may be arranged in rows. Condenser members in one row may be arranged in an opposite inclination of the condenser members in an adjacent row and the space between the rows may define a water flow passage such that water or moisture condensing on the condenser members will flow down the members and into the water flow passage for collection. The condenser members may be arranged in concentric rows.  
         [0021]     In a further preferred aspect, the present invention provides an apparatus for collecting water from the atmosphere, said apparatus including: 
        a body defining an enclosed space;     a plurality of downwardly angled condenser members within said enclosed space upon which moisture may condense, said enclosed space communicating with said atmosphere; and     collection means for collecting thus condensed said moisture.        
 
         [0025]     The condenser members may be of a conical or frusto-conical configuration.  
         [0026]     The condenser members may be of circular cross section, of rectangular cross section or of any other suitable cross section.  
         [0027]     In one form, the condenser members may be supported at spaced apart positions along respective central support members. The support members may be hollow to define flow passages through which moisture condensing on the condenser members may pass for collection.  
         [0028]     Typically, the angle of inclination of the condenser members is 45 degrees, however this angle may be varied.  
         [0029]     In yet a further preferred aspect, the present invention provides apparatus for collecting water from the atmosphere, said apparatus including: 
        an elongated chamber defining an enclosed space, said elongated chamber being inclined to the horizontal;     a plurality of condenser members upon which moisture can condense within said enclosed space;     an air inlet and an air outlet communicating said chamber with said atmosphere; and     collection means at the lower most end of said chamber for collecting condensed said moisture.        
 
         [0034]     Preferably, cooling means are provided to cool the chamber and/or condenser members within the chamber. Such means may comprise cold air tubes within the chamber. The tubes may be located adjacent to the condenser members. Preferably, the cold air tubes are supplied with cold air from an air-conditioning unit. The cold air tubes are preferably arranged within a closed circuit with the air-conditioning unit.  
         [0035]     Preferably, to enhance condensation of moisture on the condenser members, they may be coated with zircon, zeolite or similar hydrophilic material. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]     In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention wherein;  
         [0037]      FIG. 1  is a schematic plan view of a first form of moisture collection apparatus according to an embodiment of the present invention;  
         [0038]      FIG. 2  is a longitudinal sectional view of the apparatus of  FIG. 1 ;  
         [0039]      FIG. 3  is a schematic longitudinal sectional view of a further form of moisture collection apparatus according to an embodiment of the present invention;  
         [0040]      FIG. 4  is a cross sectional view of the apparatus of  FIG. 3 ;  
         [0041]      FIG. 5  illustrates a typical configuration of condenser plates for the apparatus of  FIGS. 3 and 4 :  
         [0042]      FIG. 6  illustrates the manner in which the condenser plates are supported to a corrugated wall of the apparatus of  FIGS. 3 and 4 ;  
         [0043]      FIG. 7  is a cross sectional view of the apparatus of  FIG. 2  in an alternative configuration;  
         [0044]      FIG. 8  is a sectional view of the wall of the apparatus of  FIG. 3  showing air circulation ducts through the wall;  
         [0045]      FIG. 9  is an enlarged view of one of the air circulation ducts and the manner in which air circulation in the apparatus is induced;  
         [0046]      FIG. 10  is a schematic longitudinal sectional view of a further form of moisture collection apparatus according to an embodiment of the present invention;  
         [0047]      FIG. 11  is a cross-sectional view of the apparatus of  FIG. 10 ;  
         [0048]      FIG. 12  illustrates a typical cooling tube for use in the apparatus of  FIG. 10 ;  
         [0049]      FIG. 13  is a schematic longitudinal sectional elevational view of a further form of moisture collection apparatus according to the invention;  
         [0050]      FIG. 14  is a sectional view along line A-A of  FIG. 13 ;  
         [0051]      FIG. 15  is a sectional view along line B-B of  FIG. 13  showing an alternative cross section;  
         [0052]      FIG. 16  is a schematic view of the closed circuit cooling system for use in the moisture collection;  
         [0053]      FIGS. 17 and 18  are sectional views along lines C-C and D-D showing the air intake and air outlet of the air conditioning unit of the cooling system of  FIG. 16 ;  
         [0054]      FIG. 19  illustrates an alternative moisture collection unit employing conical condensers;  
         [0055]     FIGS.  20  to  22  illustrate alternative condenser configurations;  
         [0056]      FIGS. 23 and 24  illustrate the manner in which the units of  FIG. 21  may be positioned within buildings of different configurations;  
         [0057]      FIG. 25  illustrates the manner in which conical condensers can be manufactured;  
         [0058]      FIG. 28  illustrates in exploded view an alternative condenser unit; and  
         [0059]      FIG. 27  illustrates the condenser unit of  FIG. 26  in longitudinal sectional view. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0060]     Referring to the drawings and firstly to  FIG. 1 , there is illustrated apparatus  10  for collecting water from the atmosphere in accordance with a first embodiment of the invention. The apparatus  10  comprises a tank  11  of circular cross-section and having upper and lower air inlets  12  and  13  through the cylindrical wall  14  of the tank  11  to allow circulation of air and moisture carried thereby through the tank  11 . The tank  11  is also preferably closed by a top lid. Supported within the tank  11  are a plurality of condenser plates  15  which are angled downwardly from the cylindrical wall  14  of the tank  11  but terminate short of the central axis of the tank  11  so as to defined a central water flow passage  16  for condensed water. The plates  15  may be of inverted frusto-conical form so as to extend fully around the interior of the wall  14  of the tank  11  or may be made up as a plurality of segment shaped elements as is illustrated in  FIG. 1 . The condenser plates  15  may be angled downwardly at any suitable angle such as 45° but this angle may be varied as desired.  
         [0061]     In use, moisture carried by air circulating through the tank  11  by means of the air inlets  12  and  13  will condense on the condenser plates  15  and be directed by the inclined plates  15  towards the central flow passage  16  to collect in the bottom of the tank  11 . A water outlet  17  is provided in the bottom of the tank  11  at a level such that some water remains in the tank  11  to act as a heat sink to reduce the temperature of the air within the tank  11  and promote further condensation. To improve moisture collection, air flow through the tank  11  may be enhanced by the use of a fan or other air flow inducing means.  
         [0062]      FIGS. 3 and 4  illustrate a further embodiment of water collection apparatus  18  according to the invention using the principles of the embodiment of  FIGS. 1 and 2 . The apparatus  18  includes a generally cylindrical tank  19  having a side wall  20  which is preferably insulated for example as at  21  on opposite sides, preferably by Sisalation (RTM) or other insulating material. The side wall  20  supports a roof  22  which is externally concave. The roof  22  is constructed to have inner and outer skins  23  and  24  which defined air cavities  25  therebetween. The skins  23  and  24  may also be lined with an insulating material  26  such as Sisalation. A gutter  27  is provided at the periphery of the roof  22  to collect rain water in a conventional manner. The base  28  of the tank  19  is of a concave configuration and a central water outlet  29  is provided in the base  28  for outlet of condensed water. The wall  20  may be extended so that the base  29  is supported above the ground and the base  29  can be supported by a support structure  30  extending between opposite sides of the tank  18 . Air inlet/outlets  31  and  32  are provided adjacent the upper and lower ends of the wall  20 , the air inlet/outlets  31  and  32  being formed as ducts penetrating the wall  20 .  
         [0063]     Arranged within the tank  19  are condenser assemblies  33  which are of similar configuration to that of  FIG. 2  and comprise sets of condenser panels or plates  34  which are arranged in concentric rows in opposing sets and which occupy substantially the whole cross section of the tank  19 . The panels or plates  34  in each row are inclined downwardly such that condensed moisture on the panels or plates  34  is directed to water flow passages  35  between sets of panels or plates  34  to collect on the base  28  for flow through the outlet  29 .  
         [0064]     The panels or plates  34  as also shown in  FIG. 5  may be provided with flanges  36  which can be rivetted or otherwise fastened to the side wall  20  or battens  37  on the inside of the side wall  20 . The condenser panels or plates  34  can be linked at their inner ends, for example, by being formed integrally.  
         [0065]     The side walls  19 , however, as shown in  FIG. 6  may be formed of corrugated sheets and the condenser panels or plates  34  may be secured by rivetting to corrugations  37  of the sheets such that they are at the correct spacing.  
         [0066]     The tank  19  is also provided with a central strut  39  which extends between the roof  22  and base  28 , the strut  39  being extendable to expand the base and roof to allow central drainage of water.  
         [0067]     The tank  19  as shown in  FIG. 7  may also be of a square (or rectangular) cross-section. In this configuration, the downwardly inclined condenser panels or plates  34  are again arranged in sets in rows to occupy substantially the cross-section of the tank  19  and leaving water flow passages  35  between opposing sets of panels or plates  34 .  
         [0068]     To maximise water collection, extractor fans may be provide at the bottom outlets  31  of the tank  19 . The extractor fans may be powered by solar panels either directly or through rechargeable batteries. Humidity switches may be provided on or adjacent to the tank  19  such that when the humidity drops below a certain level, such as 65% humidity, the switches switch on to start the extractor fans and exhaust dry cool air. Exhaustion of the dry cool air would result in further air from the atmosphere being introduced into the tank  19  and therefore not only increase the flow of air but maximise water collection. Further, the exhausted cool air could be recycled to pre-cool the subsequent incoming air from the atmosphere. This system may be interlocked with a temperature control system to ensure that no great quantity of hot air is introduced into the tank and thereby disrupt the water collection process.  
         [0069]     A typical arrangement of extracting dry cool air from the tank  19  is shown in  FIGS. 8 and 9 . In this arrangement, air exhaust passages  40  are formed through the tank wall  20  and in a somewhat tangential orientation. The passages  40  may be connected to a duct  41  in which air flow is induced by an extraction fan. Air forced through the duct  41  will create a low pressure in the outlet passages  40  and therefore draw air out of the tank  19 . The orientation of the passages  40  will create a circular air flow in the tank  19  to maximise contact of the air flowing into the tank  19  with the condenser plates and therefore improve efficiency of moisture collection.  
         [0070]      FIG. 10  illustrates a further embodiment of a water collection apparatus  42  according to the present invention which, in this embodiment, is in the form of an elongated chamber  43  of rectangular cross-section. The chamber  43  is supported in an inclined attitude and has an air inlet  44  at its upper end and an air outlet  45  at its lower end. The walls  46  of the chamber  43  are typically constructed to have insulating properties and for example may be formed of concrete or moulded from other materials.  
         [0071]     The chamber  43  as shown in  FIG. 11  contains sets of condenser plates or panels  47  of similar configuration to those in FIGS.  1  to  3 , the plates or panels  47  preferably extending the full length of the chamber  43  with the flow passages  48  between respective sets of panels or plates  47  directing collected moisture onto the bottom wall of the chamber  43  where it flows to the lower end of the chamber  43  for collection.  
         [0072]     To promote the condensation of moisture on the condenser plates or panels  47 , a series of cooling ducts  49  may be provided in a closed circuit, the ducts  49  extending along the length of the chamber  43  and adjacent the inner side of the walls  46  of the chamber  43  as shown more clearly in  FIG. 11 . Cold air is supplied to the ducts  49  from an air conditioning unit  50  mounted to the lower end of the chamber  43  arranged in a closed circuit with the ducts  49  such that cold air is pumped through the ducts  49  and returned to the air conditioning unit  51  for re-cooling. The closed circuit cooling system ensures that the cooling system does not need cleaning, that maximum cooling efficiency is achieved and that the risks of diseases such as legionnaires disease is minimal. To further enhance the cooling effect, the cooling ducts  49  as shown in  FIG. 12  may be provided with fins  52  arranged helically or in any other orientation relative to the ducts  49  to increase the surface area for cooling.  
         [0073]     Referring now to  FIG. 13 , there is illustrated a further embodiment of a water collection apparatus  53  according to the present invention which is similar to the embodiment of  FIGS. 10 and 11 . The apparatus  53  includes an elongated chamber  54  which is inclined to the horizontal and which, as illustrated in  FIGS. 14 and 15 , may be of a square cross-section, a circular cross-section or of any other suitable cross-sectional shape. The chamber  54  may be moulded from concrete or any other settable material, plastics or any other material.  
         [0074]     An air conditioning unit  55  is located at one end of the chamber  54  and a plurality of interconnected air supply ducts and air return ducts  56  are provided along the inner walls of the chamber  54 , in the embodiment of  FIG. 14  along the top and side walls, and in the embodiment of  FIG. 15  substantially around the inner periphery of the circular wall except at a lower portion thereof. The ducts  56  are connected to the air conditioning unit  55  in a closed circuit system such that cold air flowing into the ducts  56  from the unit  55  is returned to the unit  55  for re-cooling.  
         [0075]     In the embodiment of  FIG. 14 , planar panels  57  are supported adjacent the side and top walls of the chamber  54  and outwardly of the ducts  56 . The panels  57  support sets of downwardly angled condenser panels or plates  58  upon which moisture will condense from air flowing into the chamber  54 . The condenser panels or plates, however, may be arranged in many different orientations. The chamber  54  additionally includes sets of upper air inlet ducts  59  at one end of the chamber  54  and sets of lower air outlet ducts  60  at the opposite end of the chamber  54 . The base of the chamber  54  may be provided with a trough-shaped water collection panel  61  which directs water to an outlet  62  for distribution to a storage location or for use.  
         [0076]     In the embodiment of  FIG. 15  in which like components to those of  FIG. 14  have been given like numerals, angled condenser plates  58  are supported on a part cylindrical panel  63  arranged coaxially within the cylindrical chamber  54  and outwardly of the cooling ducts  56 . The air inlet ducts  59  in each embodiment may be angled to create a spiral inlet flow through the chamber  54 .  
         [0077]     In use, the chamber  54  is inclined to the horizontal such that the water outlet  62  is located lowermost. In this attitude, convection air flows through the chamber  54  from the air inlets  59  to the outlets  60  which will also promote condensation of moisture on the plates or panels  58 . This is further encouraged by the cooling effect of the cold air flowing through the ducts  56  adjacent the plates or panels  58 . Moisture condensing on the plates or panels  58  will drip onto the collection panel  61  or the lower inner surface of the chamber  54  for passage to the water outlet  62 .  
         [0078]      FIGS. 16-18  illustrate schematically the general configuration of the air cooling system wherein the outlet  64  from the air conditioning unit  55  supplies air to the multiple ducts  58  for passage along the chamber  54  with the air from the ducts  56  being returned at the inlet  65  to the air conditioning unit  55  for re-cooling.  
         [0079]     Referring now to  FIG. 19 , there is illustrated a further form of moisture collection unit  66  according to an embodiment of the invention in which, in this instance, the condenser panels or plates  67  are of a conical configuration to defined downwardly angled condenser surfaces of approximately 45 degrees. The condenser panels or plates  67  are arranged at a spaced position along a central pole  68 . The pole  88  may comprise a hollow tube and apertures  69  may be provided in the tube at spaced positions towards the apexes of respective conical panels or plates  67 . Moisture condensing on the panels or plates  67  flows down the surfaces of the panels or plates  67  and passes through the apertures  69  into the central tube for collection.  
         [0080]     The condenser panels or plates  67  may typically be of the form shown in  FIG. 20  being of circular cross-section, whilst in the embodiment of  FIG. 21 , the conical panels or plates  67  are provided with a series of apertures or slots  70  which allow for continuous air circulation through the unit  66 . The conical panels or plates  67  may have any cross-section such as rectangular or square as shown in  FIG. 22 .  
         [0081]     The units  66  may be arranged in any configuration, for example, in buildings  71  and  72  of circular or rectangular cross section as shown in  FIGS. 23 and 24 . The building may also be of the form of the building of  FIG. 3  with water passing through the central poles  68  being directed onto a base  29  for common collection of the water from all units  66 . Such a building may also incorporate an air extraction system as previously described to ensure exhausting of dry air and replacement with moist air from the atmosphere. The building may also incorporate a closed circuit cooling system of the type described with reference to FIGS.  10  to  16  to ensure efficient condensation of moisture on the panels or plates  67 .  
         [0082]     Typically, and as shown in  FIG. 25 , the conical panels or plates  67  may be constructed from a flat sheet  73  which may be folded into a circle to create the panel  67  with the overlapping ends then being joined, for example, along the dotted line in  FIG. 25  by welding such as spot welding by fasteners or other connection arrangement. Formed conical panels  87  may then be slid over the pole  88  and annular collars  74  provided between each panel  67  to set the spacing between the panels  67  and form the assembled unit  68 .  
         [0083]     In each of the above described systems, the condenser plates may be at steeper or less steep angles from that described. The moisture collection systems as described above may be provided in various sizes and may be made portable for various uses or erected on site in larger installations for supplying water to communities or for agricultural purposes. To avoid costs of pumping, the systems may be erected at an elevated location such as on mountains so that the collected water can be supplied by a gravity supply system. The extent of collection of water may be governed so that collection tanks or other storage devices are not required. Other benefits of the systems are that they would allow development of areas normally regarded as marginal such as deserts and also allow for rebuilding of underground water supplies.  
         [0084]     Each of the described systems may incorporate air extraction fans or other means to increase air flow through the space containing the condenser members. Each system may also incorporate means to cool air within the space such as the described closed circuit air conditioning system. Each system may also include humidity control means which allows, or causes by the use of fans, for example the air extraction fans, greater air flow through the condenser space when humidity drops. Associated with the humidity control means may be a temperature control means which will prevent hot air flowing through the condenser space. Each system may be further adapted such that any exhausted cool air is recycled to pre-cool the subsequent incoming air.  
         [0085]     Flow through the condenser space may be maximised by ventures or funnels at the upper end of the condenser space to slightly pressurise the condenser space and induce flow through the space. Pitot tube extraction may be used at the lower end of the condenser space to allow extraction of used dry air and its replacement by new incoming humid air.  
         [0086]     It will be appreciated that the above described embodiments are only exemplification of the various aspects of the present invention and that modifications and alterations can be made thereto without departing from the inventive concept as defined in the following claims.