Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ATMOSPHERIC WATER GENERATOR
Field of the Invention
This invention relates to the field of atmospheric water generators, and in
particular to a water generator system employing a synergistic relationship
between the
radiator and condenser in the refrigeration thereof wherein cooling of
parallel roll-bond
evaporator plates increases the efficiency of the radiator, reducing power
consumption while
the roll-bond evaporator plates increase water recovery from airflow from a
single set of fans
stationed to sequentially urge the airflow through the gaps between the roll-
bond evaporator
plates and through the heat radiating core of the radiator.
Background of the Invention
Generally, natural freshwater resources are scarce or limited in many areas of
the world, including areas such as, for example, deserts and and lands, due to
low precipitation
and high salinity of surface and underground water. Shortage in supply of
potable water and
fresh water is increasing at a vast rate, as deserts expand and overtake
fertile land, and as many
of the natural ground water resources are being depleted. Furthermore, shifts
in patterns of the
global climate over time have resulted in a drop in the rate of rainfall in
many areas. For
example, hunger and starvation is spreading in areas such as, for example,
Africa, because of
shortage of fresh water to raise domestic animals and crops for food.
Sparse population and scattered population pockets in many areas make the
application of water desalination and other water treatment technologies
uneconomical due to
the low demand and the high cost of water distribution from a central system
over a wide
stretch of land. For example, such methods of supplying potable water may be
inaccessible to
remote and/or impoverished areas of the world due to lack of natural
resources, wealth,
infrastructure and technical expertise. Alternatively, transportation of loads
of fresh water is
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costly and exposes water to contamination en route and during handling and
storage. For
example, remote areas of the world may lack the necessary transportation
infrastructure to
allow transportation of potable water to these remote areas.
Accordingly, there is a need for localized production of fresh water to
provide
water for human drinking, and fresh water for raising animals and for
irrigation as well as
other human uses, that is reliable, affordable and produces little or no
industrial pollution.
Additionally, there is a need that the system may be transported and assembled
in a number of
remote areas inhabited by humans where little or no natural resources are
available for
providing potable water. The apparatus should be accessible to individuals
with limited
technical expertise and be available in a range of sizes so that it maybe used
in areas that lack
abundant space.
In the prior art applicant is aware of the following United States Patents:
United States Patent No. 3,675,442 which issued July 11, 1972 to Swanson
discloses a mechanical refrigeration means which intermittently cools a fresh
water bath.
Water from the bath is conducted to vertically aligned condenser filaments by
conduit means.
The condenser filaments provide condensing surfaces at a temperature below the
dew point of
the air. A distributing means directs condensed water, depending on its
temperature, to either
the bath or from the apparatus as output water.
United States Patent No. 4,812,132 which issued to Nasser et al. on January 8,
1980 describes a tower having a pair of vertically aligned spaced apart air
guides wherein the
lower air guide includes a cooler which can simultaneously condense moisture
from the air and
wherein the upper air guide includes a heat dissipater of a refrigeration
cycle. Air guides are
associated with respective blowers and induce ambient air into the air guide
at a location
between the blowers. Air is displaced through the air guides into a heat
exchanging
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relationship. The tower may be used to collect drinking water by condensation
from the
atmosphere.
United States Patent No. 4,255,937 which issued March 17, 1981, to Ehrlich
discloses a dehumidifier in an upper compartment of a cabinet, and a water
collecting tank in a
lower compartment of the cabinet. Oppositely perforated walls in the cabinet
provide access
of moisture carrying air to the dehumidifier. A water feed conduit leads from
the dehumidifier
to the water collecting tank. The water collecting tank is cooled by a
refrigerator.
United States Patent No. 4,433,552 which issued February 28, 1984, to Smith
discloses a refrigeration system including an evaporator positioned in an
atmospheric duct
whereon water vapour is then condensed and collected.
United States Patent No. 4,892,570 which issued to Littrell on January 9, 1990
discloses a water precipitator which provides a water supply over an extended
surface area of
land in a high temperature region by condensing water on piping chilled by a
refrigerant
circulating within the piping.
United States Patent Nos. 4,891,952 and 5,033,272 which issued respectively
January 9, 1990, and July 23, 1991, to Yoshikawa et al. disclose a
refrigerator having a
refrigeration cycle which is applied alternatively to first and second coolers
so as to provide
for quick freezing of the second cooler by the refrigerant pressure being
reduced in two steps
by corresponding first and second capillary tubes corresponding to the first
and second
coolers. For quick freezing the coolant is evaporated in the second cooler
only, and during
usual operation no refrigerant flows into the second cooler whereby the second
cooler remains
substantially free of frost.
United States Patent No. 4,933,046 which issued June 12, 1990, to May
discloses a water purifying system having a condenser made of two superposed
sheets of
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hydrophobic plastic film bonded together to form a steam path through the
condenser so that
as steam entering the condenser is cooled by ambient air it condenses into
water which is then
removed from the condenser.
United States Patent Nos. 5,106,512, 5,149,446, and 5,203,989, which issued,
respectively, April 21,1992, September 22, 1992, and April 20 1993, to Reidy
disclose a water
generating device for obtaining potable water from ambient air wherein a
condenser is
provided for extracting water vapour.
United States Patent Nos. 5,259,203 and 6,755,037 which issued November 9,
1993, and June 29, 2004, respectively, to Engel et al. disclose using a
refrigeration system
which includes a compressor, evaporator, fan, condenser, and reservoir to
extract drinking
water from the air.
United States Patent No. 5,469,915 which issued November 28, 1995, to
Cesaroni discloses a panel heat exchanger having a plurality of parallel tubes
located between
two plastic sheets that envelope and conform to the shape of the tubes,
wherein the sheets are
bonded together between the tubes.
United States Patent No. 5,555,732 which September 17, 1996 to Whiticar
discloses a portable dehumidifier wherein a blower fan causes humid air to
come into contact
with a cold plate causing water vapour to condense from the air. The
condensate drips from
the cold plate into a trap.
United States Patent Nos. 5,669,221 and 5,845,504 which issued to LeBleu on,
respectively, September 23, 1997 and December 8, 1998, disclose a portable,
potable-water
generator for producing water by condensation of dew from ambient air wherein
an enclosed
heat absorber cools air to its dew point and collects droplets of condensate
into a closed
system.
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United-States Patent Nos. 6,289,689 and 6,779,358 which issued, respectively,
September 18, 2001, and August 24, 2004, to Zakryk et al. disclose a water
collection machine
having an evaporator coil structured to cycle a cold refrigerant liquid
therethrough wherein the
coil is disposed in line in an air inlet so that moisture condenses on the
coil and may be
collected in the form of water droplets.
United States Patent No. 6,397,619 which issued to Cheng et al. on June 4,
2002, discloses a dehydrating device which includes an electrode member
mounted under the
lower end of the assembly. Positive and negative voltage sources are connected
to the
electrode member and the lower end of the assembly so as to form an electric
field
therebetween. Water condensed on the assembly is pulled and removed from the
surface of
the assembly by means of periodical change of the electric field.
United States Patent No. 7,140,425 which issued to Romero-Beltran on
November 28, 2006, discloses a plate-tube type heat exchanger having a plate
with a plurality
of channels running parallel there along and a plurality of tubes housed and
secured to the
channels thus forming a circuit for circulation of a heating fluid, a cooling
fluid or a means of
heating.
United States Patent No. 7,269,967 which issued September 18, 2007 to Cole
discloses removing excess moisture from the evaporator coils of an air-
conditioning system by
vibrating the coils, wherein the coils may be vibrated by mechanical or
acoustic devices such
as solenoid plungers or acoustic transducers.
United States Patent No. 7,272,947 which issued September 25, 2007, to
Anderson et al. discloses a water producing system for condensing water from
air and for
collecting the condensed water in a storage tank. In a duct fluid circuit, an
operating fluid
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dumps heat to a second circuit such as refrigeration cycle and the cooled
operating fluid lowers
the temperature of a water condensation member.
In my co-pending United States patent applications filed, respectively,
September 27, 2004, and December 22, 2004 and published March 30, 2006 under
respectively, publication Nos. 20060065001 and 20060065002, I describe a
system for
producing potable water from the atmosphere wherein the system includes a
plurality of panels
arranged within an enclosure substantially parallel to each other along a
central access, and
wherein each of the panels is made of a material on which water condensate
from the
atmosphere forms in response to a temperature differential between the
material and the
atmosphere passed through the panels. Cooling fluid cools the panels so as to
form water
condensate on the surface of the panels. The panels are rotated about the
central axis within
the enclosure to remove the water condensate from the surfaces of the panels.
Summary of the Invention
In summary, the atmospheric water generator according to the present invention
may be characterized as including a refrigeration system including a motor,
compressor,
radiator, evaporator, and at least one fan, wherein the evaporator includes a
spaced apart array
of roll-bond evaporators. The radiator and the array of evaporators are
adjacent one another
and arranged in fluid communication therebetween. The fan or fans cooperate
with the radiator
and the evaporators to induce an in-flow stream of air from ambient air into
and through,
firstly, the condenser, and secondly, the radiator. Consequently, the in-flow
stream of air is
cooled by the evaporator as the in-flow stream passes through the evaporator
as a through-flow
stream of air. The cooled through-flow stream of air then passes through a
heat dissipating
section of the radiator so as to optimize functioning of the radiator in the
refrigeration system.
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Advantageously the roll-bond evaporators are each made of unitary planar
aluminium sheet having refrigeration conduits formed therein. They may have a
thickness of
substantially 1.5mm. In one preferred embodiment all of the evaporators in the
array of
evaporators are roll-bond evaporators.
Preferably the array of evaporators are spaced apart by a through-flow
spacing of substantially between one half inch and one inch. In one embodiment
the through-
flow spacing is substantially constant. The through-flow spacing form airways
extending the
length of a first dimension of the array of evaporators corresponding to the
direction of the
through-flow stream of air. The first dimension may be horizontal. The second
dimension of
the array of evaporators corresponds to the width of the spacing of the
through-flow spacings,
and is orthogonal to the first dimension. The through-flow spacings also
extend in a third
dimension orthogonal to the first and second dimensions. That is, where the
first dimension is
horizontal and the second dimension is also horizontal the third dimension is
vertical. In a
preferred embodiment the airways are sufficiently long along the first
dimension so that the
through-flow stream of air becomes turbulent.
For one embodiment the airways are also sufficiently long so that airstream
boundary layers of the through-flow stream of air form turbulent boundary
layers along the
airway on opposed facing surfaces of adjacent evaporators in the spaced apart
array of
evaporators. The second dimension may be sufficiently small so that the
turbulent boundary
layers on the opposed facing surfaces extend substantially fully across the
second dimension.
In a further embodiment the opposed facing surfaces of adjacent evaporators
further include turbulent flow trippers to trip laminar flow components and
laminar boundary
layer components of the through-flow stream of air into downstream turbulent
flow and
turbulent boundary layer components. For example, the turbulent flow trippers
may include
protrusions formed on the opposed facing surfaces.
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Advantageously, the third dimension extends substantially the full height of
the
evaporators, and water droplets condensing on the surfaces of the evaporators
descend
downwardly along the third dimension by force of gravity. A fluid source may
be provided so
as to project a film of fluid onto the surfaces of the evaporators to urge the
droplets into and
along their cascading descent. For example, the fluid source may include at
least one
apertured sprayer mounted at an upper end of the array of evaporators. The
fluid may be
water, and the apparatus may further comprise a water collector positioned
under the array of
evaporators. The water collected in the collector may be re-cycled to the
water source by a
water re-cycler such as a pump. The fluid may also be air, and the apparatus
may further
comprise a motivator for urging a downward flow of air along the first
dimension.
In one embodiment a fill of elongate strands may be positioned in-between
adjacent evaporators in the array of evaporators. The fill may be a mesh of
sufficient volume
to be partially in contact with, or suspended between, so as to be
interleavered between,
opposed facing surfaces of the adjacent evaporators. The fill may be a
metallic such as
aluminium mesh.
Brief Description of the Drawings
Figure 1 is, in right side perspective view, the atmospheric water generator
unit
according to one embodiment of the present invention.
Figure 2 is, in left side partially exploded perspective view, the water
generator
of Figure 1.
Figure 2a is in side elevation view, one of the roll-bond evaporators of
Figure
2.
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Figure 2b is a section view along line A-A in Figure 2a.
Figure 2c is a section view along line B-B in Figure 2a.
Figure 2d is a section view along line C-C in Figure 2a.
Figure 3 is, in right side perspective view, a horizontal cross-section on
line 3-
3 in Figure 2 illustrating the water generator with the cowlings removed.
Figure 4 is, in plan view, the evaporator, radiator, and fan sections of a
second
embodiment of the water generator according to present invention.
Figure 5 is the partially cutaway view of Figure 4 with the evaporator plate
vibrator and part of the chassis removed.
Figure 6 is, in right side perspective view, the chassis of the water
generator
according to the present invention.
Figure 7 is, in right side perspective view, the second embodiment of the
water
generator according to the present invention, with the cowlings removed.
Figure 8 is, in left side perspective view, the water generator of Figure 7.
Figure 9 is, in right side perspective view, the water generator of Figure 7
showing the evaporator unit, the radiator, the fans, a chassis, a vibrator,
and a water collection
tray.
Figure 10 is an enlarged view of the water generator of Figure 7.
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Figure 11 is a further enlarged view of Figure 10 with the cross-bar over the
vibrator removed.
Figure 12 is the water generator of Figure 1 I with the chassis, cross-
members,
and vibrator of Figure 11 removed.
Figure 13 is, in perspective view, a pair of roll-bond evaporators sandwiching
an aluminium mesh therebetween.
Figure 13a is, and enlarged view with the roll-bond evaporators cutaway, of
the aluminium mesh of Figure 13.
Figure 14 is, in elevation view, an alternative embodiment of a roll-bond
evaporator according to one aspect of the present invention, wherein the
surfaces of the
evaporator have sharp-sided scales punched therein.
Figure 14a is an enlarged perspective view of a portion of Figure 14.
Figure 14b is an enlarged view of a portion of Figure 14a.
Figure 15 is, in perspective view, the water condenser section of the water
extractor according to the present invention, with a fluid sprayer mounted
between the upper
ends of the roll-bond evaporators.
Figure 15a is an enlarged view of a portion of Figure 15.
Figure 16 is, in perspective view, the water extractor according to the
present
invention with a water ionizer mounted to the chassis.
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Figure 16a is, in elevation view, one of the water ionizing bars of Figure 16.
Detailed Description of Embodiments of the Invention
In the drawings wherein similar characters of reference denote corresponding
parts in each view, atmospheric water generator 10 includes an evaporator unit
12 cooperating
with refrigeration components 14 mounted adjacently within rigid chassis 16
and housed
within cowlings 18.
One aspect of the present invention is the synergy and increased efficiency
gained by the use of only a single set of fans 20 which function both as
cooling fans for the
refrigeration cycle and also to draw moisture laden air in in-flow direction A
through a
parallel, spaced-apart array of roll-bond evaporators 22. A single roll-bond
evaporator is
shown in Figure 2a showing the arrangement in one preferred embodiment of
liquid coolant
conduits 22a. Conduits 22a may thus in one embodiment be arranged so as to
extend
vertically along substantially the entire height dimension of the roll-bond
evaporator 20. In
one embodiment, not intending to limiting, as illustrated by the downward
arrows in Figure 2a,
the liquid refrigerant enters conduits 22a from the top of roll-bond
evaporator 20 and as
illustrated by the upward arrows, also exit from the top of roll-bond
evaporator 20.The in-flow
pipes (not shown) and out-flow pipes (not shown) transfer liquid coolant to
each conduit 22a
in each roll-bond evaporator 20. The in-flow and out-flow pipes may for
example be mounted
in the relatively easy to access space directly above chassis 16 so as to be
contained between
the top of the array of roll-bond evaporators 22 and the interior of the top
of cowlings 18. As
would be known to one skilled in the art the array of pipes are in fluid
communication with
corresponding in-flow and out-flow manifolds (not shown) which are themselves
connected by
further conduits to compressor 14a.
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Advantageously, the vertical array of fans 20 may in one embodiment not
intending to be limiting include three five-bladed fans. Inducted airflow in
direction A is
drawn horizontally along a first dimension in direction B through the array of
roll-bond
evaporators 22 substantially along the entire vertical height of the array.
The compressor and
other corresponding conventional refrigeration components, cool the liquid
refrigerant, which
is then pumped through conduits 22a simultaneously in all of the roll-bond
evaporators 22 so
that air drawn in the spacing have a second dimensional or width between the
evaporators is
cooled so as to condense water droplets onto the exterior surfaces 22b of the
evaporators
without freezing. The resulting cooled through-flow air is then drawn through
fans 20 so as to
exit in direction C. The cooled through-flow air is also forced through the
core of radiator 14b
of refrigeration assembly 14 so that the through-flow of already cooled air
from the roll-bond
evaporators provides for increased cooling of radiator 14b and thus more
efficient operation of
the refrigeration cycle. Increased efficiency has also been gained by using
more than one
radiator 14b, for example two radiators 14b, stacked vertically.so as to lie
in the same plane
facing and parallel to the vertically stacked set of fans. Thus in the
illustrated embodiment, the
set of three fans would have for example two separate radiators 14b, one on
top of the other.
In applicant's experience the use of stacked radiators reduced the power
consumption by the
compressor.
In applicant's experience, this increased cooling of the radiator has resulted
in
reducing the required power consumption of compressor 14a thereby reducing the-
power
consumption of the apparatus overall. The present invention thus differs in
one respect from
the prior art in that whereas in the prior art separate fans are provided to
draw air through
radiator-style water-condenser units and separate fans are provided for the
condenser/radiator
of the refrigeration system, in the present invention applicant realized space
and energy
savings by housing the refrigeration assembly and the water condensing
assembly adjacent to
one another so as to share the operation of a single fan or set of fans,
thereby resulting in
increased synergistic efficiency of the system.
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Moisture laden air entering in direction A into the planar spaces 22c
interleaved
between roll-bond evaporators 22 passes through the spaces in direction B, and
exits from
spaces 22c as cooled air the cooled air the enters the heated air spaces
within the core of
radiator 14c wherein the air is warmed as the core is cooled. The air passes
from radiator 14c
as hot air exiting fans 20 in direction C.. Again, it is significant to note
that fans 20 draw air in
the through-flow in horizontal direction B across substantially the entire
height of evaporators
22, i.e. along a third dimension of the apparatus which is for example
approximately 5 feet
high in one commercial embodiment.
Thus for the embodiment illustrated, which is not intended to be limiting,
chassis 16 may have approximate dimensions of two meters (91 inches) in
height, 1.7 meters
(77 inches) in width, 0.9 (41 inches) in depth thus making for a relatively
compact water
generator. As may be seen, chassis 16 thus provides a rigid frame supporting
the refrigeration
components including the parallel array of roll-bond evaporators 22 held
suspended
substantially vertically, and the substantially vertical array of fans mounted
adjacent the
evaporators.
Sheet-like roll. bond evaporators 22 are mounted suspended within chassis 16
parallel to one another. Without intending to be limiting, in the embodiment
of Figures 2-4
horizontal rotatable shafts 24 are rotatably mounted to corresponding vertical
uprights 16a of
chassis 16. One rotatable shaft 24 is provided for each corner of the array of
roll-bond
evaporators 22. A racheting winch mechanism 26 may be provided for releasable
uni-
directional rotation of shafts 24 so that they may be simultaneously or
individually rotated.
Rotating shafts 24 in one direction winds a length of flexible line 28 onto
shaft 24. Flexible
line 28 is secured to each corner of each roll-bond evaporator 22. through
corresponding
eyelets 22a.
Each ratchet and pawl mechanism 26 includes a toothed ratchet. The tensioning
of lines 28 is controlled by rotation of the ratchet and the operation of a
ratchet-engaging pawl.
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Mechanism 26 together comprise an intermittent rotation controller wherein
motion from a
handle or for example motorized device is converted into intermittent circular
motion having a
constant rotational direction. Mechanism 26 may be. released so as to unwind
shafts 24
thereby releasing tension on lines 28 by the release of the pawl from the
teeth of the ratchet.
In the embodiment of Figure 5, 7, and 9-12, instead of using flexible line 28
wound onto shafts 24 to suspend and tension roll-bond evaporators 22, springs
36 are mounted
through eyelets 38 in the corners of evaporators 22 so as to tension the
evaporators between
cross-members 16c of chassis 16.
Chassis 16 may be mounted on casters 30 or other wheeled or tracked or skid
assemblies to allow for ease of positioning.
Roll-bond evaporators are known in the prior art for use in for example
domestic refrigerators. In such refrigerators the sheet of the roll-bond
evaporator is typically
bent into a U-shape to form a cooling box. Thus the conduits formed in
conventional roll-
bond evaporators are directed in such a way to allow for bending of the sheet
along where the
corners of the box are to be formed. Roll-bond evaporators are formed by
bonding together
two thin sheets of aluminium so that the two sheets become a single unitary
sheet of
aluminium. The conduits are formed by masking the desired conduit paths before
the two thin
sheets are formed together so that, once the two sheets are formed into a
single unitary sheet
the masked path remains thereby separating the two sheets along the length of
the masking.
The remaining separated sheets along the masked path are then further
separated so as to
define the elongate cavities of the continuous conduits through which
refrigerant such as
FreonTM may be passed. Roll-bond evaporators are thus very efficient as they
only present a
thin aluminium layer between the refrigerant within the conduits and the air
passing over the
outer surface of the roll-bond evaporators.
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In the present invention, the roll-bond evaporators are, at least in the
illustrated
embodiment which is not intended to be limiting, used in a planar form. Thus
the conduits
may be advantageously run the entire length of the sheets without having to
worry about where
the sheet will be bent.
Two further factors in maximizing the production of water by atmospheric
water extraction are also dealt with in the present invention; namely,
maximizing the number
of water droplets and consequently the volume of water condensing on the
surfaces of the roll-
bond evaporators, and, secondly, maximizing the rate of removal and
completeness of removal
of the water droplets once condensed onto the surfaces of the roll-bond
evaporators.
With respect to the former factor, applicant determined that if the spacing
between the roll-bond evaporators is too large then a large percentage of the
through-flow of
air in direction B will likely never come into contact with the surface of a
roll-bond evaporator
and instead will continue straight through and into the core of the radiator,
from there passing
out in direction C through the fans. Consequently, applicant adjusted the
spacing between the
evaporators so as to be in the range between approximately one half inch and
one inch. In this
fashion applicant attempted to better mix the air-flow to increase contact of
moist air with the
surfaces of the evaporators which had been cooled below the dew point.
Although not wishing
to be bound by any particular theory of physical operation of the mixing,
applicant sought to
trigger turbulent mixing of the laminar air-flow B 1 as it travelled along the
spacing between
the roll-bond evaporators. Applicant thought that turbulent rather than
laminar boundary
layers in the relatively long narrow planar passages between the roll-bond
evaporators where
the air-flow was moving at relatively low velocity, approximately in the order
of 3000-3500
CFM per fan, allowed the build-up of the boundary layer and in particular a
turbulent
boundary layer until substantially all of the flow in the spacing between the
roll-bond
evaporators was turbulent flow B2. This turbulently mixed incoming moisture
laden air-flow
so as to expose as much as possible of the volume of air-flow to the chilled
surfaces of the roll-
bond evaporators. Thus in the present invention and in particular in the
illustrated
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embodiment which is not intended to be limiting but rather merely
illustrative, each of the roll-
bond evaporators has a dimension of approximately 2'/z feet wide by
approximately 5-6 feet
high. The array of roll-bond evaporators, again without intending to be
limiting, may contain
as illustrated at least nineteen roll-bond evaporators, although fewer will
work but with
reduced efficiency, each having a spacing therebetween of in the order of 1/2
inch to 1 inch
spacing. In one embodiment, the array of roll-bond evaporators when viewed in
plan view,
that is, from above when seen in horizontal section, forms an array which is
approximately
square in dimension for example approximately 2% feet square.
Another factor in the operation of the atmospheric water generator according
to
the present invention is controlling the frosting of the roll-bond evaporators
so as to minimize
and advantageously avoid, the build-up of frost or ice on the surfaces of the
roll-bond
evaporators. One method by which this is accomplished is running the
refrigeration assembly
at a lower capacity, for example, by reducing the available power from the
motor. Thus
although likely not sufficient for refrigerating roll-bond evaporators for use
in for example a
refrigerator for keeping food products stored at a safe temperature slightly
above freezing,
applicant has found that providing a motor which only delivers approximately
1/16t of a
horsepower per roll-bond evaporator minimizes the formation of frost or ice so
as to maximize
the formation of moisture droplets on the surfaces of the roll-bond
evaporators. In applicant's
experience, providing 1 /16a' of a horsepower per roll-bond evaporator reduces
the power
requirement, as compared to a conventional refrigeration use of the roll-bond
evaporator by
approximately one half. In operation during experiments on a prototype
applicant has
observed that the atmospheric water generator may consume approximately 6.5
kilowatts (28
amps at 20 volts) using a 6 horsepower motor to generate approximately 20
litres of captured
water per hour during an experiment conducted in Lima, Peru, on a day during
which the
atmospheric humidity was approximately 68%, at 30 degrees Celsius.
In a further experiment to increase the efficiency of condensing water
droplets
onto the chilled surfaces within the water condensing section 12, applicant
inserted sheets of
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aluminium mesh 40 so as to substantially fill the volume in the spacing
between the roll-bond
evaporators. This experiment resulted in an increase in approximately 24
litres per day of
recovered water. Although not wishing to be limited to any particular theory
of operation,
applicant believes that the aluminium mesh assists in increasing the
turbulence of the airflow
of the through-flow air moving in direction B in the spacing between the roll-
bond evaporators
and also provides substantially chilled surfaces in the mesh because the roll-
bond evaporators
are in contact with the aluminium mesh and have thus also chilled the
aluminium mesh, at
least in proximity to the roll-bond evaporators. This may result in a
temperature gradient with
slightly increasing temperature in the aluminium mesh further away from the
contact with the
roll-bond evaporator surface. Although it might have been thought placing such
obstacles into
the airflow path might decrease the efficiency by choking the air-flow,
therefore by reducing
the volumetric quantity of airflow moving through the array of roll-bond
evaporators and
possibly also adversely affecting the operation of the radiator in the
refrigeration system so as
to decrease the efficiency of the refrigerator and therefore increase the
power consumption,
applicant did not notice any substantial increase in the amperage required by
the fans to
maintain an approximately constant airflow rate in the refrigeration system,
instead, as noted
above, realizing an increased volumetric recovery of water into tray 32
underneath the array of
roll-bond evaporators.
In keeping with applicants experience in optimizing the volumetric recovery of
water by the use of turbulence in the through-flow in direction B of the
moisture laden air
arriving in direction A, in a further alternative embodiment, the surfaces 22b
of roll-bond
evaporators 22 may be formed with protrusions, or "scales" 42 or other flow-
tripping devices
such as would be known to those skilled in the art of fluid mechanics, which
would rapidly trip
a laminar flow into a turbulent one. Applicant has also noticed that water
condensation in the
form of droplets more readily form where sharp surfaces or sharp intersections
of surfaces are
formed. Thus, advantageously the flow-tripping devices might beneficially be
in the shape of
sharp edged scales or breaks in the otherwise smooth surfaces 22b of the roll-
bond evaporators
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22. The edges of the aluminium mesh would also provide relatively sharp edges
along the
aluminium threads or strips forming the mesh.
Addressing now the second factor in optimizing the volumetric recovery of
water from the atmospheric water generator according to the present invention;
namely,
optimizing the method of removal of water drops from the surfaces of the roll-
bond
evaporators, in addition to merely relying on gravity to disrupt the surface
tension holding a
water droplet adhered to the side of a roll-bond evaporator, applicant has
devised several
means for accomplishing improved detachment of the water droplets from the
surfaces of the
roll-bond evaporators. Firstly, the roll-bond evaporators themselves are not
coated with any
paint or like finish but rather are coated with Teflon" or like low surface
friction coatings or
polymers. Secondly, or alternatively, the water droplets may be ionized as
better described
below. Lastly, mechanical means may be provided to assist for example by the
use of a
mechanical resilient wiper (not shown) being translated relative to, while in
contact with, the
surfaces of the roll-bond evaporators, or for example the use of a mechanical
shaker as better
described below to vibrate each of the roll-bond evaporators in the array of
roll-bond
evaporators, or the use of a water spray recycling water from tray 32 and
sprayed by spray-
bars 46 via apertures 46a onto the surfaces 22b of the roll-bond evaporators
22 so as to provide
wetted surfaces to which the water droplets will only adhere with reduced
viscosity, or
alternately the use of jets of air from aperture 46a for example directed
downwardly onto the
surfaces of the roll-bond evaporators from a linearly perforated s such as may
be used to spray
water onto the roll-bond evaporators so as to wet the surfaces. In the case of
spraying air, the
air spray provides a downwardly moving boundary layer airflow comingling with
the through-
flow of air travelling in direction B in the spacing between the roll-bond
evaporators.
Advantageously the spray-bars 46 are provided in parallel spaced apart array
interleaved
between the upper ends of evaporators 22 so that opposed facing arrays of
apertures 46a
formed an opposite sides of spray-bars 46 spray both sides of each evaporator
22. Spray-bars
46 may be supplied by a manifold 46b which itself is pressurized by pump 48
via feed-line 50.
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In yet a further embodiment (not shown), the roll-bond evaporators may be
replaced with cooling pipes embedded in a large volume of aluminium mesh, for
example
sufficient volume so as to fill the inside of chassis 16 encasing water
condenser 12, where the
cooling pipes may be of a serpentine shape through the volume of aluminium
mesh so as to
attempt to equally chill the aluminium mesh. Fans 20 thus draw air in
direction A into the
pores of the mesh and the through-flow then diffuses its way through the
porous mesh from
the in-flow side to the out-flow side from which the airflow, as before, flows
through the core
of radiator 14b and then through fans 20 so as to be expelled in direction C.
In a further embodiment (not shown), instead of the use of aluminium mesh, a
bristled member, or a plurality of bristled members having bristles of for
example aluminium
filaments or spikes or needles, are mounted in the spacing between the roll-
bond evaporators.
The bristled members are advantageously chilled for example by reason of being
in thermal
contact with roll-bond evaporators 22 or for example by reason of chilled
pipes being run in
the spacing between the roll-bond evaporators, the bristles being mounted to
the chilled pipes.
In yet a further embodiment, additional fans 20 may be added to extract a
larger
volume of air through the evaporators of the water condenser section 12 at the
coldest end of
the roll-bond evaporator plates, typically, at the end of the plates adjacent
the in-flow of the
refrigerant.
In one embodiment, a perforated plate 44 is mounted across the inlet side of
the
array of roll-bond evaporators 22, for example mounted in the inlet opening to
the housing
formed by cowlings 18, so that incoming air in direction A has to pass through
the perforations
in the plate. In applicant's experience, the use of such a perforated plate 44
may drop the air
temperature of the incoming flow in direction A while the humidity in the air
remains
constant. Thus, the use of such a perforated plate mechanically lowers the air
temperature
thereby better matching the temperature of the incoming airflow to that of the
chilled surfaces
22b of roll-bond evaporators 22. In applicant's experience the closer matching
of temperatures
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in this manner increases production volume of recovered water per the amount
of power used
to generate the water.
As described above, one of the mechanical methods for breaking the adherence
of the water droplets to the surfaces 22b of roll-bond evaporators 22 is to
mechanically shake
the array of roll-bond evaporators. In the illustrated embodiment which is not
intended to be
limiting, a vibrator 34 is mounted on plates 34a, themselves mounted to cross-
members 16d,
so as to be centered above the array of roll-bond evaporators on a cross bar
16b. Thus
vibration of cross bar l6b by the operation of vibrator 34, shakes chassis 16
thereby
transmitting the vibration via shafts 24 or springs 36 (or other suspension
means) to the
corners of the roll-bond evaporators 22. Vibrator 34 may in one embodiment be
an electrically
driven device, for example a conductive wire winding through which when a
current is pulsed
the induced electric fields operate on an offset metallic object (not shown)
so as to vibrate the
metallic object within the housing of the vibrator. Other means for inducing a
vibration in
chassis 16 would be well known to those skilled in the art.
With respect to the above mentioned ionizing method, to decrease the
adherence of water droplets to the surfaces of the roll-bond evaporators
applicant has
determined that pulsing electricity in the approximately 15 kilovolt range at
a low amperage,
for example as would be obtained by running 12 volts through an inverter as
from an
automobile, and running the pulse electricity through pointed electrodes 52 on
internally-wired
conduit 54, or through the above mentioned perforated plate 44 for, example
mounted just
upstream and adjacent the in-flow side of the array of roll-bond evaporators,
decreases the
droplet adherence to surfaces 22b. Alternatively, pulsing the electricity
through a screen
mounted between an air filter and chassis 16, or through perforated plate 44
using a pulse
generator which feeds for example in the range of 15,000 kilovolts which might
be obtained
from an automobile coil into the metal of the screen, or a mesh, or the plate,
may increase the
droplet flow rate down surfaces 22b. The ionizing in applicant's experience so
as to
oxygenates the water droplets as they are borne therethrough in the moisture
laden airflow. In
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applicant's opinion, and to which applicant does not wish to be bound, the
water droplets
become negatively charged thereby attracting the droplets to the grounded
surfaces of the roll-
bond evaporators. In applicant's experience, the result is an oxygenated
supply of water
scavenged from the incoming airflow and which provides the resulting water
with a light-blue
appearance. The light-blue water provides an aesthetically appealing look to
the water which
may then simply be bottled and sold to the consuming public who will perceive
the difference
between ordinary tap water and the oxygenated water for at least the reason of
the difference in
color as between the two.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is
to be construed in accordance with the substance defined by the following
claims.
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