GB2117656A - Atmospheric water extractor - Google Patents

Abstract

A plant dimensioned for the sole purpose of collecting and storing water derived from the atmosphere and suitable for use in hot and arid areas. The plant comprises a refrigeration unit 3, 7 unit, a heat exchanger 9, an air circulation system, cooled and insulated ducting for the water produced, an evaporation proofed water storage receiver 14. The heat exchanger 9 cools the incoming moist air 5 from outgoing refrigerated dried air without admixture. The heat exchanger in larger equipments is aided with an evaporation refrigerator working from waste heat from the primary compressor type refrigerator. The motive power for the primary refrigerator may be derived from a wind turbine mechanically or magnetically coupled to the compressors 3 and air circulation fans 4. <IMAGE>

Description

SPECIFICATION Wind powered atmospheric water extractor The invention comprises a refrigeration unit, a heat exchanger and a wind operated source of mechanical power.

In many arid areas of the world portable water is very scarce or absent. Water from wells may be of high salinity. Water brought by transport for survival of men or animals can be expensive. A local means of providing small quantities of water condensed from air is the object of this invention.

To obtain water from moist air the air must be cooled and the latent heat of condensation removed.

A cubic metre of air weighs about a kilogram and has a heat capacity of 1000 joules per degree centigrade.

The latent heat of evaporation of water is 2500 joules per gram. At 40 0C and 100% humidity a cubic metre of air holds 78gms water vapour. At near freezing point the quantity is reduced to 6 gms. Thus at 20% humidity 9 gms of water is available for extraction and at 10% humidity only 2 gms since the cooled air will remain saturated. If the temperature is reduced to -10"C and ice produced then a further 4 gms become extractable.

As an example if 1 m3 of air at 400C is processed per second and 5 gms of water extracted the heat to be removed is 40 kilowatts for cooling and 12.5Kw.

for condensation. This represents a daily output of 100 gallons.

According to the invention an economy in energy is effected by using the dry cold air passing from the refrigeration chamber to pre-coolthe incoming air and thus, in the example described, reduce the total requirement to about 20 Kw.

The refrigeration unit as a heat pump may supply its waste heat, about half this power, 10 Kw., to supplementfarm or domestic needs.

If this equipment operates on electrical power, at the current cost of 5p per KwH, operational costs would be 12p per gallon. A price which compares well with transported water.

According to the invention wind power is employed to operate the refrigerant compressor and to drive the fans which assist air flow through the cooling channels.

It is not contrary to the intention of the invention if the complete unit is provided with alternative electrical, solar, or heat energy to augment the wind energy input or to substitute for it on windless days; nor if the humidity is low to moisten the input air with unpotable water conveyed to humidify the air intake or pumped to an humidifying unit by wind power.

The power available from the wind on a given rotor area is proportional to that area and to the cube of the wind speed. It amounts to nearly half the kinetic energy in the air stream impinging on the rotor area, providing the rotor speed at blade tip approaches six times the wind velocity. For a wind speed of 10 metres per second an eight meter rotor could provide 20 kilowatts.

In figure 1 a form of the invention is shown in its basic detail. The rotor axis of the windmill (1 ) is coupled mechanically by a belt or chain reduction gear (2) to the refrigerant compressor (3) and also to a fan (4) which promotes the flow of air through the cooling system. Moist air enters the heat exchanger at (5) and passes between the cooled fins (6) to the main cooling and condensation chamber of the refrigerator (7). Water is deposited here and drains out through a valve (8) to a heat lagged circular collector channel (13) and thence to the water resevoir (14). The valve (8) has a floating ball valve and prevents air passing in either direction. The cold and dry air from (7) passes to the outer part of the heat exchanger (9) where it removes heat from the incoming air in the duct (5) through the heat conducting fins (6) without admixture of the air streams.The emergent cool air stream may pass over the compressor to assist cooling.

The whole assembly described is mounted to rotate about a vertical axis on the tower (11) and fitted wither a 'weather vane' to keep the air entry facing the wind.

The air processing unit is located below the wind rotor so that when possible the air intake may be disposed amid trees where the humidity is higher, while the rotor vanes remain exposed to the wind.

Alternatively air ducting may be provided to draw the input air from damp locations.

Performance control devices to regulate the eqiupment which are of known design to vary the pitch of the wind vanes automatically or to control the air flow through the cooling unit with adjustable louvres operated on temperature or dew-point are not shown in the drawing.

Compressors with a direct drive allow the gradual escape of refrigerant through the shaft bearings and in applications of this type where the compressors are difficult of access piped replacement tubes are provided to ground level.

In an alternative arrangement the compressors may be hermetically sealed units and driven by a magnetic coupling. Figure 2 shows such an arrangement diagramatically. A rotor of the Darrieus or Savonius type rotates on a vertical shaft (1) and carries with it a ring of magnets (2) which cause the drive wheel (3) in the hermetically sealed compressor unit (4) to follow the rotation. The drive wheel is coupled to compressors (5). At the lower end the rotor shaft operates a fan to promote air flow through the cooling unit.

In the construction of such equipments the compressor in which heat is generated may be provided with cooling fins and mounted apart from the air cooling unit where it is wind cooled. Alternatively where moist ground is available it may be ground or water cooled and with its heat deployed to increase the humidity of the air to be processed.

In constructions of the equipment in which evaporation type refrigeration is used heating of the refrigerant may be produced by friction or churning The drawing(s) originally filed were informal and the print here reproduced is taken from a later filed formal copy.

of a viscous liquid derived from wind power and thus employ a hermeticaly sealed unit.

The design of wind operated power generators of recent and older types is sumarised in a text book "Wind Machines" compiled by F.R.Eldridge, second edition published by Van Nostrand Reinhold Company New York and London, 1980. Many different uses of wind power are also discussed in this text.

CLAIMS (filed on 2/8/82) 1. An athmospheric-water condensing and collecting plant having thermally lagged water conduit and receiver cooled by the associated refrigeration unit.

2. A plant as claim 1 in which refrigeration is aided by a heat exchanger between the incoming moist air and the outgoing cold dried air.

3. A plant as claim 2 in which the refrigerator compressor(s) are mechanically coupled to a wind turbine.

4. A plant as claim 2 in which the refrigerator compressor(s) are magnetically coupled to a wind turbine.

5. A plant as claims 3 or 4 in which the heat exchanger is augmented by an evaporation refrigeration cycle operating from waste heat from the main refrigeration compressors.

New claims or amendments to claims filed on 3.5.83 Superseded claims All 1. A refrigeration type athmospheric-water condensing and collecting plant in which air cooling is aided by a heat exchanger between the incoming moist air and the outgoing cold dried air and in which the refrigerator compressor is mechanically driven by a wind turbine.

2. A plant as claim 1 but in which the wind turbine is magnetically coupled to the compressor.

3. A plant as described in either of the above claims in which there are a plurality of compressors.

4. A plant as claim 1 or 2 in which the refrigerator is of the evaporation type indirectly energised by a wind turbine.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. of a viscous liquid derived from wind power and thus employ a hermeticaly sealed unit. The design of wind operated power generators of recent and older types is sumarised in a text book "Wind Machines" compiled by F.R.Eldridge, second edition published by Van Nostrand Reinhold Company New York and London, 1980. Many different uses of wind power are also discussed in this text. CLAIMS (filed on 2/8/82)

1. An athmospheric-water condensing and collecting plant having thermally lagged water conduit and receiver cooled by the associated refrigeration unit.

2. A plant as claim 1 in which refrigeration is aided by a heat exchanger between the incoming moist air and the outgoing cold dried air.

3. A plant as claim 2 in which the refrigerator compressor(s) are mechanically coupled to a wind turbine.

4. A plant as claim 1 or 2 in which the refrigerator is of the evaporation type indirectly energised by a wind turbine.

4. A plant as claim 2 in which the refrigerator compressor(s) are magnetically coupled to a wind turbine.

5. A plant as claims 3 or 4 in which the heat exchanger is augmented by an evaporation refrigeration cycle operating from waste heat from the main refrigeration compressors.

New claims or amendments to claims filed on 3.5.83 Superseded claims All

1. A refrigeration type athmospheric-water condensing and collecting plant in which air cooling is aided by a heat exchanger between the incoming moist air and the outgoing cold dried air and in which the refrigerator compressor is mechanically driven by a wind turbine.

2. A plant as claim 1 but in which the wind turbine is magnetically coupled to the compressor.

3. A plant as described in either of the above claims in which there are a plurality of compressors.