ATMOSPHERIC WATER GENERATION SYSTEMS

FIELD OF THE INVENTION

The present invention relates to the field of atmospheric water generation systems and more particularly to integrated air conditioning and atmospheric water generation systems that condense water from air to provide drinking water.

BACKGROUND OF THE INVENTION

Potable drinking water is a shrinking resource around the world. It is in short supply in many parts of the world, and in the future it will become more even challenging to supply the water requirements of growing populations. Climate change effects have begun to alter expected weather and water patterns, and these changes, combined with an ever-increasing human population and increased water requirements for domestic, agriculture and industrial sectors has led and will lead to shortages.

The problem is particularly acute in places such as tropical islands, and floating installations such as oil rigs, and at remote or tropical locations that lack a water supply infrastructure. For example, on many islands, consumers must purchase expensive bottled water, or refill water jugs with water of questionable purity at local water stations. There are no wells, most houses are not on city water and even if they are, the city water is not potable. Many homes use rain water runoff guttered into a cistern sanitized with bleach.

In other locations lacking a water piping infrastructure, such as in the Middle East, the typical water source is delivered "jug water," obtained from local water sources. Such water is often of questionable purity and flavor.

The problem is also found in places where the existing water infrastructure has not been maintained. Water pipes may leak, cisterns may be cracked, such that the quantity of available water is less than amounts available a century ago. In addition, such systems also are at risk for contamination of the water supply from such leaks and from other causes.

Ambient air typically contains moisture. The amount of water in ambient atmospheric air varies with temperature and pressure. Hot humid air contains more water than cold dry air. Moisture contained in ambient air condenses into liquid form as droplets when the air temperature drops below a determined dewpoint.

Many atmospheric water generating machines have been proposed in the past. The typical machine has a cooling element that receives filtered ambient air and cools the air to condense moisture. The condensation is collected, sterilized by UV light and/or ozone, and stored and/or dispensed. The temperature of the cooling element is maintained so that is does not reach the freezing point which would decrease water collection efficiency. However, such systems, whether large or small, have been dependent on an electrical system infrastructure to operate the systems. Small, water cooler size systems, while portable, have insufficient capacity to supply the needs of a substantial population. Larger installations are all custom built and are not designed to be readily deployed using standard commercial transport systems.

Last but not least the water production cost using atmospheric water generating machines of the prior art is very high and not cost-effective.

SUMMARY OF THE INVENTION

In view of the above, an object of an embodiment of the present invention is that of solving or at least positively reducing the above mentioned drawbacks. Another object is that of reaching this goal with a simple and rational solution.

These and other objects are achieved by the embodiments of the invention as defined herein.

In accordance with one embodiment of the invention an atmospheric water generation system comprises an air treatment unit located in a casing. The air treatment unit comprises an air inlet for ambient air; a crossflow air to air heat exchanger having a first heat exchange area and a second heat exchange area, the first heat exchange area having a first inlet receiving air from the air inlet and a first exit for discharging air, the second heat exchange area having a second inlet and a second exit; a water condensing heat exchanger receiving air from the crossflow heat exchanger first exit; a water collecting container located below the water condensing heat exchanger; an air recirculation chamber extending from the water generating heat exchanger to the second inlet of the crossflow heat exchanger; and an air blower circulating air in the air treatment unit.

A chiller unit is also located in the casing, and comprises a compressor, a condenser, and an expansion valve, and an evaporator which is operably and thermally connected to the water condensing heat exchanger to provide a flow of cooled refrigerant to the water condensing heat exchanger.

A water treatment unit is also provided in the casing. The water treatment unit is connected to the water collecting container and includes one or more of: a particulate filter; an activated charcoal filter; and an ultraviolet light sterilizing chamber and/or an ozone water sterilization system. Optional additional components include a mineralization system to add mineral salts or other additives to collected water.

A generator system is optionally also located in or on the casing. The generator system generates electrical power to operate the air treatment unit, chiller unit, and water treatment unit. The generator system may comprise: an internal combustion engine generator, or a hydrogen fuel cell; or a solar panel system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side and top perspective view of an embodiment of an atmospheric water generation system in accordance with the invention with its side and top exterior walls removed to display the internal components thereof.

FIG. 2 is a front, side and top perspective view of the atmospheric water generation system of FIG. 1 with its side and top exterior walls removed to display the internal components thereof showing air circulation through the air treatment unit.

FIG. 3 is a top plan view of the atmospheric water generation system of FIG. 1 with its top exterior wall removed to display the internal components thereof.

FIG. 4 is a side elevation schematic view of the atmospheric water generation system of FIG. 1 showing alternative options for the location of the water treatment unit and generator system.

FIG. 5 is a side elevation schematic view of an air treatment unit of an atmospheric water generation system in accordance with the invention.

FIG. 6 is a top plan schematic view of the air treatment unit of an atmospheric water generation system of FIG. 5.

FIG. 7 is a side elevation schematic view of an embodiment of a water treatment unit of an atmospheric water generation system in accordance with the invention.

FIG. 8 is a front, side and top perspective view of the atmospheric water generation system of FIG. 1 having all its side walls and showing openable louvers and hatches provided in the end walls, sidewalls and roof thereof.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-8, where like numerals indicate the same elements in the Figures, an atmospheric water generation system 20 is shown. Atmospheric water generation system 20 is capable of generating 10.1 m ³ /day of pure water under optimum atmospheric conditions.

Atmospheric water generation system 20 includes an air treatment unit 40 associated with a chiller unit 80, a water treatment unit 100, and a generator system 120.

According to the illustrated embodiment of the invention the atmospheric water generation system 20 is a high performance integrated water production machine which is assembled into a casing having a standard shipping container size, specifically a container 22 which is the size of a ISO standard 40' high-cube container (length 12,19 m x width 2,44 m x height 2,90 m) (40' x 8' x9'6"). According to different embodiment of the invention larger casing may also be used including a 45' high cube container size, but in most cases the 40' high-cube container size is easily transportable and is sufficient for the invention.

Casing 22 is seen in FIGS. 1-6, and contains the air treatment unit 40, the chiller unit 80, the water treatment unit 100, and the generator system 120. In general, the component elements of atmospheric water generation system 20 are each sized to occupy approximately one-third of the casing 22. The three main component elements - the air treatment unit 40, the chiller unit 80, and the generator system 120; are designed as modular components having a length of about 4 meters. In most configurations, the water treatment unit 00 will be co-located with the generator system 120.

According to this embodiment of the invention the air treatment unit 40, as seen in FIGS. 1-6, has an inlet 42 for receiving an incoming stream of ambient air, and an inlet chamber 44 extending from the inlet 42. An air filter system 45 is preferably directly associated to the the inlet air. In detail the air filter system 45 is provided in the inlet air chamber 44. Air filter system 45 operates to remove insects, windblown debris, dirt, sand and other contaminants from the incoming air stream. The air filter system 45 may comprise any type of filter known in the art for air filtration, and may be a flat filter, pleated filter, pocket filter, rigid cell filters. The filter media may be selected from glass fibers or synthetic fibers. In one embodiment, the filters are selected and sized to accommodate a design airflow in heavy duty (dusty) conditions.

Inlet air chamber 44 connects to a crossflow air to air heat exchanger 46 having a first heat exchange area 48 and a second heat exchange area 54. The first heat exchange area 48 has a first inlet 50 receiving air from the inlet chamber 44 and a first exit 52 for discharging air. The second heat exchange area 54 has a second inlet 56 and a second exit 58. Cross flow heat exchanger 46 is preferably a high performance, low weight aluminum heat exchanger with non-fouling corrugated surfaces and a single pass efficiency of 50 - 70%. Epoxy coated plates may be selected as an option for use in coastal environments.

Crossflow heat exchanger 46 is generally a rectangular solid positioned at an angle such that the heat exchanger as viewed from the side appears to be inclined with respect to an horizontal plane A (Fig.5). According to the invention the angle β of inclination of the crossflow heat exchanger 46, with respect to the horizontal plane, is comprised in a range between 30 and 60 degrees. Preferably the angle β of inclination is preferably 45 degrees. The uniquely positioned angled crossflow heat exchanger allows the air treatment unit 40 to have a substantially reduced size while still obtaining the desired efficiency. Therefore this configuration concurs to minimize the overall size of the casing, facilitating the transportation of the atmospheric water generation system 20.

As described hereafter, the crossflow heat exchanger 46 operates to precool the incoming air stream before the air reaches the water condensing heat exchanger 62 where water is condensed from the air and collected.

This solution allows to increase the performance of the atmospheric water generation system 20 and the productivity of water quantity, for a given amount of supplied energy, up to 40%.

A condensation chamber 60 extends from the crossflow heat exchanger first exit 52. The water condensing tube and plate heat exchanger 62 is located in the condensation chamber 60. Surfaces of the water condensing heat exchanger 62 are chilled to below the dew point, and accordingly water vapor in the air stream condenses out of the air stream and onto the plates and other surfaces of the water condensing heat exchanger 62. A drop separator 64 (mist eliminator) is located downstream of and adjacent to the water condensing heat exchanger 62 and collects entrained water droplets from the air stream.

A water collecting container 65 is a tray or bin and is located below the water condensing heat exchanger 62 and the drop separator 64 so that condensed water that is collected on the chilled surfaces of the water condensing heat exchanger 62, and which runs down the walls of the water condensing heat exchanger 62 by gravity, is collected and pumped to the water treatment unit 100 by means of a pump 101.

An air recirculation chamber 67 extends from the water condensing heat exchanger 62 to the second inlet 56 of the crossflow heat exchanger 46. Air that has passed through the crossflow heat exchanger 46 and been precooled, and which has then been significantly further cooled by passage through the water condensing heat exchanger 62, is thus returned to the crossflow heat exchanger 46 to provide cooling to the incoming air stream. Air recirculation chamber 67 may be comprised of two or more subchambers 67a and 67b such as illustrated in FIG. 7 with connecting openings between the various subchambers.

Cooled demoisturized air exits the crossflow heat exchanger 46 from the second exit 58 of the crossflow heat exchanger 46 into an outlet chamber 66. Outlet chamber 66 exhausts the cooled, demoisturized air to an air outlet 70. In the preferred embodiment, air outlet 70 comprises two laterally located exhaust vents 70a on sides 22a of the casing 22, but the air outlet 70 may be located elsewhere, such as in an end wall of casing 22, as desired.

According to a different embodiment of the invention air outlet 70 will preferably be connected by ducting to a building, tent or other structure where cooled air is desired.

An air blower 68 is preferably located in air recirculation chamber 67 between subchambers 67a and 67b. Air blower 68 may be any type of energy efficient blower system known in the art and may include centrifugal fans and axial fans. Although a single appropriately sized blower may be used, to better fit the blower units in the casing 22, there are preferably two smaller blower units 68 provided side-by side in wall 63 between subchambers 67a and 67b. Alternatively, air blower 68 may be located in the outlet chamber 66, or any of the other chambers 44, and 60.

The above described components of the air treatment unit 40, disclosed in this embodiment of the invention, are sized to process at least 30,000 m ³ /hour airflow, and preferably are sized to process between 30,000 m ³ /hour and 40,000 m ³ /hour airflow. A chiller unit 80 is also located in the casing. Chiller unit 80 may be based on any of a number of known cooling technologies, however, in most applications a conventional vapor compression refrigeration cycle will be the most robust and versatile system. Thus, the chiller unit 80, as shown in FIG. 4, is a refrigeration system comprising a coolant fluid circulating through a compressor 82, a condenser 84, an expansion valve (not shown), and an evaporator 88.

Compressor 82 is preferably a semi-hermetic single screw compressor. The coolant is preferably R-134a coolant. The condenser 84 is a tube and fin condenser. The expansion valve 86 is an electronic expansion valve. The evaporator 88 is a single pass direct expansion shell and tube evaporator. The evaporator stage of the chiller unit 80 is contained in the chiller unit 80. The evaporator stage chills a water/glycol coolant mixture which is circulated by a circulator pump to the water condensing heat exchanger 62. The water condensing heat exchanger 62 contains channels through which the water/glycol coolant mixture is circulated, chilling the surfaces of the water condensing heat exchanger 62 to condense water thereon. Cooling is thus delivered to the water condensing heat exchanger 62 to maximize water production.

Desirably chiller unit 80 has a cooling power range of between 50 and 400 kW. It is preferable that the chiller unit 80 be able to deliver cooling power of 400 kW in to permit operation of the unit in a wide range of atmospheric conditions.

A water treatment unit is also provided in the casing 22. Water treatment unit 100 is illustrated in FIG 7. The water treatment unit 100, is connected to the water collecting container 65 by means of the pump 101 and includes one or more of, and preferably all of: particulate filters 102 and 103; an activated charcoal filter 104; and an ultraviolet light sterilizing chamber 106. Particulate filter 102 is a 50 pm (micron) filter; particulate filter 103 is a 5 pm (micron) filter. The activated charcoal filter 04 has a porosity of 5 pm. The particulate filters 102, 103 and the activated charcoal filter 104 are preferably cartridge filters. Ultraviolet light sterilizing chamber 106 comprises an ultraviolet lamp capable of irradiating water at a wavelength between 245 nm and 285 nm, preferably including 254 nm, at a sufficient dose and for a sufficient time period to sterilize microorganisms in the produced water. An alternative sterilization system such as an ozone injection system may be used. Particulate filters 102 and 103, and the activated charcoal filter 104 are connected in series.

The water treatment unit 100, comprises also a calcite media mineralization system 108 to add mineral salts or other additives to collected water to improve flavor, prevent bacteria, and provide essential dietary minerals to the collected water.

The mineralization system 108 is connected in series to the activated charcoal filter 104 and comprises two mineralization units 108a connected in parallel between them and fluidly connected to the ultraviolet sterilizing chamber 106.

The purified water is then delivered to a storage tank 110. Storage tank 110 is desirably a 100 litre tank sized to hold collected water. Storage tank 110 is provided with an appropriate outlet valve system, so that collected water in storage tank 1 0 may be dispensed into jugs, water trucks, or to a local sanitary water distribution piping system.

The air treatment unit 40 and the water treatment unit 100 are sized to accommodate water production flow of up to 10.1 m ³ /day.

A generator system 120 optionally also is located in or on the casing 22. The generator system 120 generates electrical power to operate the air treatment unit 40, chiller unit 80, and water treatment unit 100. The generator system 120 may comprise: an internal combustion engine generator, or a hydrogen fuel cell; or a solar panel system.

In FIGS. 1-3, generator system 120 is a self-contained diesel engine 122 and generator 124. Diesel engine 122 and generator 124 desirably have a capacity of at least 250 kW, with an optional range of up to 400kW. The diesel engine includes a 120 litre fuel tank 126, and heavy duty air and oil filter systems. The generator 124 is a synchronous three phase alternator. Preferably, the water treatment unit 100 and the generator system 120 are co-located adjacent each other within the same section of the casing. In other embodiments, the water treatment unit 100 and the chiller unit 80 are co-located adjacent each other within the same section of the casing.

The three main component elements - the air treatment unit 40, the water treatment unit 100 with the chiller unit 80; and the generator system 20; are designed as modular components. Each modular component has a length of about 4 meters. The modular design of the present invention provides a great deal of flexibility. The above noted three main component elements can be placed in casing 22 in various combinations as needed. This permits a convenient modular approach to fabricating each atmospheric water generation system 20.

The casing 22 containing the atmospheric water generation system 20 is provided with openings for inlet and exhaust air to the air treatment unit 40, the chiller 80 and the diesel engine of generator system 120. Hatches covering the chiller unit 80 can be opened to permit air flow through chiller unit 80. Appropriate doors and hatches allow access to the various components. These louvers, doors, and hatches can be closed when the system 20 is transported or when dust storms or other bad weather events occur to protect the system components. They can then be opened when the system is operated. In a preferred embodiment, illustrated in FIG. 11 , air treatment unit 40 has a powered adjustable louvered shutter 202 at air inlet 42, and a powered adjustable louvered shutter 204 at air outlet 70, that automatically open when the system is operated. Manual hatch doors 206, 208, and 210 allow access to various parts of the air treatment unit 40. In this preferred embodiment, the chiller unit 80 has powered upper hatch doors 212 and 214, and lateral hatch doors 218 and 220 on both sides of casing 22 that automatically open when the system is operated. Generator system 120 also has powered adjustable louvered shutters 220 and 224 at the air inlet and outlet for the diesel engine. A manual hatch door 222 provides access to the generator system 120. The operation of the atmospheric water generation system 20 is controlled by an appropriate control system which coordinates the operation of the system components and collects and acts on data collected by sensors in the system.

The atmospheric water generation system 20 has a potable water production capacity which is greater than or equal to about 10 cubic meters a day at reference conditions (T=30°C and Relative Humidity=70%). It is easily transported using existing intermodal transport systems. It can be supplied in a self contained system that can be delivered to disaster sites such as areas devastated by floods, tsunamis, or other disasters which disrupt water supplies. It can be transported to tropical locations such as islands and to remote areas in need of water.

An important feature of the present invention is that it provides for concurrent generation of both water and cooled air. This dual functionality permits the atmospheric water generation system of the present invention to be economically viable by providing two significant and desirable output flows.

The present invention is therefore a new and nonobvious invention that can assist in providing clean water resources to the parts of the world where water is badly needed.

While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.