Note: Descriptions are shown in the official language in which they were submitted.
CA 02516002 2005-07-29
WATER CONDENSER
Field of the Invention
This invention relates to the field of water condensers generally, and in
particular to a water condenser providing for optimized controlled cooling of
an ambient
airflow to its dew point temperature so as to condense moisture from the
ambient air to
provide potable water.
Background of the Invention
At any given moment the earth's atmosphere contains 326 million cubic miles
of water and of this, 97% is saltwater and only 3% is fresh water. Of the 3%
that is fresh water,
70% is frozen in Antarctica and of the remaining 30% only 0.7% is found in
liquid form.
Atmospheric air contains 0.16% of this 0.7% or 4,000 cubic miles of water
which is 8 times
the amount of water found in all the rivers of the world.
= 0.16% of that 0.7% is found in the atmosphere
= 0.8% of that 0.7% is found in soil moisture
= 1.4% of that 0.7% is found in lakes
= 97.5% of that 0.7% is found in groundwater
Nature maintains this ratio by accelerating or retarding the rates of
evaporation
and condensation, irrespective of the activities of man. It is the sole source
and means of
regenerating wholesome water for all forms of life on earth.
In addition, most of the world's fresh water sources are contaminated. A total
of
1.2 billion people in the world lack access to safe drinking water and 2.9
billion people do not
have access to proper sanitation systems (World Health Organization). As a
result, about 3.4
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million people, mostly children, die each year from water-related illnesses.
According to the
United Nations, 31 counties in the world are currently facing water stress and
over one billion
people lack access to clean water. Half of humanity lacks basic sanitation
services and water-
borne pathogens kill 25 million people every year. Every 8 seconds, a child
dies from drinking
contaminated water. Furthermore, unless we dramatically change our ways, by
2025, close to
two-thirds of the world's population will be living with severe freshwater
shortages.
There is a huge global need for cost effective and scalable sources of potable
water. Current technologies require too much energy to operate efficiently and
the resultant
cost of treated water puts these technologies out-of-reach for the majority in
need. Desalination
plants exist in rich nations such as the United States and Saudi Arabia but
are not feasible
everywhere. The lack of infrastructure in developing nations makes large
plants with high-
volume production impractical, as there is no way to transport the water
efficiently.
There is a need for small scalable water extraction plants that will meet the
needs of individuals, communities and industries. This invention can responded
to that need by
developing an extraction unit that functions off-the-grid to make clean pure
water, anywhere
where the need exists.
The present invention is a device that extracts moisture vapor from
atmospheric
air for use as a fresh water source. The device may utilize the sun as the
primary energy source
thereby eliminating the need for costly fuels, hydro or battery power sources.
The water
collection device of the present invention provides flexibility over prior
devices, allowing for
productive installations in most regions of the world. As the water collection
device's
preferred power source is solar energy, the amount of available power for the
device increases
as installations of the device get closer to the equator where it is hotter
year round.
The invention is designed to allow one small water cooler sized unit to
provide
cooking and drinking water for a family, simply by harvesting the water vapor
from humid air.
CA 02516002 2005-07-29
Private individuals, industries and communities could control their own water
supply through
the use of the device's technology. It is practical for many uses in domestic,
commercial or
military applications and offers ease of use and clean water of a highest
quality anywhere,
anytime. The modular design of these devices allow for increased capacity,
simply by adding
S more modules.
In addition to domestic use larger units based upon the same basic technology
will be appropriate for many other applications where larger water supplies
are required. The
12 Volt compressor of the cooling system may be replaced with a larger 110
Volt compressor
with appropriately sized components such as the evaporator and the condenser
and the unit
will he capable of condensing much larger quantities of water when electrical
power is more
readily available.
The devices solar water condenser technology may be applied to a variety of
uses from residential to recreational and from commercial and agricultural to
military and life
saving in extreme water deprived regions of the world.
This invention may be used for obtaining pure drinking water, for cooking
purposes or for other household uses such as cleaning or bathing. The system
may also be
used on boats or in vacation areas, on camping trips, trekking and places
where drinking water
delivery systems are not developed. The unit may be used to produce fresh
water for bottling
purposes or for larger commercial applications such as restaurants, offices,
schools, hotel
lobbies, cruise ships, hospitals and other public buildings. The system may
also be used in
playing fields and sports arenas.
Additionally, the technology may be used to augment the supply of water being
used to irrigate selected crops using micro or drip irrigation systems. These
systems deliver the
right amount of water at the right time, directly to the roots of plants. As
well, the technology
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CA 02516002 2005-07-29
may be used to for bottled water production or virtually any other application
where water is
needed.
The proposed technology provides an opportunity to end much suffering. The
death and misery that flow from unsafe water is overwhelming. More than 5,000
children die
daily from diseases caused by consuming water and food contaminated with
bacteria,
according to a recent study released by UNICEF, the World Health Organization
(WHO) and
the UN Environment Program (UNEP).
Currently, 1.2 billion people have no access to safe drinking water and that
number is increasing steadily with forecasts of a potential 2.3 billion or one-
third of the earth's
population without access to safe water by 2025 (World Health Organization's
statistics from
World Commission on Water for the 21st Century). These at-risk children and
their families
are not restricted to rural areas in undeveloped nations. "Millions of poor
urban dwellers have
been left without water supply and Sanitation in the rapidly growing cities of
the developing
world. The poor are often forced to pay exorbitant prices for untreated water,
much of it
deadly," reports William Cosgrove, director of World Water Vision, Paris. Our
device can
relieve much of this suffering.
A rapid increase in water demand, particularly for industrial and household
use,
is being driven by population growth and socioeconomic development. If this
growth trend
continues, consumption of water by the industrial sector will be double by
2025 (WM0).
Urban population growth will increase demand for household water, but poorly
planned = water and sanitation services will lead to a breakdown in services
for hundreds of
millions of people. Many households will remain unconnected to piped water.
The present invention offers a practical and affordable solution to many of
the
world's water supply problems.
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It should be noted that while much of the prior art is simply extracting what
it
can from the air based . upon a simplistic and uncontrolled process, some
water will be
extracted but with little concern for efficiency. This lack of efficiency can
be explained by
understanding the different types of beat that are used in the process of
extracting water from
air.
The heat that is used to bring air down to dew point is "specific heat". The
heat
used to bring the temperature of air below dew point is "latent heat" and
represents a dynamic
in the condensation process. The optimal condensation process uses as little
"latent heat" as is
possible.
For reference, specific heat means:
1. The ratio of the amount of heat required to raise the temperature of a
unit mass
I 5 of a substance by one unit of temperature to the amount of heat
required to raise
the temperature of a similar mass of a reference material, usually water, by
the
same amount.
2. The amount of heat, measured in calories, required to raise the
temperature of
one gram of a substance by one Celsius degree.
Latent heat means:
The quantity of heat absorbed or released by a substance undergoing a change
of state, such as ice changing to water or water to steam, at constant
temperature and pressure.
This is also called heat of transformation.
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In the optimal condensation process if too much air is drawn through the
system
the system cannot take enough of the total volume of air to a temperature
below dew point and
will therefore result in poor performance from the system.
if not enough air is drawn through the device the air temperature will drop to
below dew point but as there is less air moving through the system, there is
respectively less
water available to be drawn from that air. There are as well other issues that
arise when too
little air is moved through the system such as freezing and wasted energy in
the overuse of
"latent" heat.
Therefore there is an optimal quantity of air that will travel through the
system
based upon a number of variables and that optimal quantity of air will change
as the other
variables change. It is therefore necessary to have a system that is monitored
and reacts to the
changes in temperature and humidity so as to ensure ongoing optimal operation
is achieved.
Summary of the Invention
The water condenser according to the present invention is a device that may
use
various input source energy supplies to create a condensation process that
extracts potable
water from atmospheric air.
In one embodiment the water condenser is portable and the refrigeration cycle
may be driven by a 12 Volt compressor that allows for an efficient
condensation process for
creating a potable water supply. The input source energy for the compressor
may be supplied
from many sources such as a Wind turbine, batteries, or a photovoltaic panel.
Additionally the
design may be fitted with transformers to accommodate other power supplies
such as 110 Volt
or 220 Volt systems when such electrical power is available, or the device may
be sized or
scaled up so as to accommodate such electrical power sources directly. For
example, the .
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device might use a 110 Volt compressor and simply have the device's other
components
scaled-up to accommodate the larger compressor.
Rather than filtering water with conventional systems such as reverse osmosis
or carbon filtration, the device filters the atmospheric air then provides a
condensation process
that lowers the temperature of that air to below dew point of the airflow. The
air is then
exposed to an adequate sized, cooled surface area upon which to condense, and
the water is
harvested as gravity pulls the water into a storage compartment.
The disclosed invention creates a high quality water supply through a process
of filtering air rather than water. The device may be fitted with a screen to
keep out larger
contaminates. Downstream of the screen may be a pre-filter. The pre-filter may
be removable
for cleaning. Downstream of the pre-filter may be a high quality filter such
as a HEPA filter to
ensure the airflow is pure and depleted of contaminates that might impede upon
the quality of
water that is created by the condensation process downstream of the air
filtration.
Rather than using a capillary tube metering mechanism for feeding refrigerant
fluid into the refrigerant evaporator, such as is normally used for smaller
refrigeration systems,
the device according to the present invention may be fitted with an automatic
suction valve so
as to allow for the device to adapt to varying loads created by different
environments. One
object is that the condensation process is to provide efficient processing of
atmospheric, that is
= ambient air. Thus the intake airflow downstream of the air filtration may
be pre-cooled, prior
to entering a refrigerant evaporator used to condense moisture out of the
intake airflow, by
passing the intake airflow through an air-to-air heat exchanger, itself cooled
by cooled air
leaving the evaporator. That is, the incoming airflow is cooled before it
enters the refrigerant
evaporator section by passing it in close proximity in the heat exchanger to
the cooled air that
is leaving the refrigerant evaporator. Air-to-air heat exchangers may be
constructed to be very
efficient, reaching 80% efficiency and therefore reducing the temperature of
the incoming
airflow towards the dew point of the airflow prior to entering the refrigerant
evaporator
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CA 02516002 2005-07-29
reduces the temperature differential or temperature drop that must obtained by
passing the air
over cooled surfaces in the refrigerant evaporator to obtain the dew point
temperature, and thus
may have a significant impact upon the efficiency of the condensation process
and thus the
efficiency of the device. For example the device may thus be optimized to
increase the airflow
rate and still be able to reduce the airflow temperature to the dew point, or
will be able to
handle very hot inflow temperatures and still reduce the dew point temperature
a reasonable
airflow volume over time so as to harvest a useful amount of moisture. Sensors
provide
temperature, for example ambient inlet temperatures, refrigerant evaporator
inlet and
refrigerant evaporator outlet temperatures, humidity, and fan speed or other
air flow rate
indicators to the processor to optimize and balance those variables to
maximize harvested
moisture volume. Embodiments of the present invention may thus include varying
the flow of
air through the system such that the device has a prescribed amount of air
passing through the
refrigerant evaporator and a different flow of air passing through the
refrigerant condenser of
the corresponding refrigerant circuit, allowing for optimized function.
In addition to the benefits described above our water condenser unit may add
additional value in further processing. The harvested water may be further
processed so as to
increase the value of the water, for example by adding back inorganic minerals
missing or only
present in small amounts in the water so as to accommodate the perceived value
of these
minerals to the consumer. The process may also add organic minerals back into
the water
which are of benefit to the human body, rather than simply adding back
inorganic minerals that
the human body may not be able to properly assimilate.
There are numerous means by which to put back minerals and trace elements
into the harvested water. For example, a small compartment with a hinged door
allowing it to
be easily accessed may be provided between a drip plate at the bottom of the
refrigerant
evaporator and a downstream water storage container so as to have all
harvested water pass
through this chamber. A provided mineral puck may inserted into this chamber
by a user so
that as harvested water drips over the mineral puck the puck dissolves thereby
adding desired
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elements to the harvested water. The user thereby controls re-mineralization
of the harvested
water. Additional health remedies may also be added to the harvested water
such as colloidal
silver, water oxygenation additives, negatively ionized hydrogen ions or other
health
enhancing products.
In summary, the water condenser according to the present invention may be
characterized in one aspect as including at least two cooling stages or first
cooling a primary or
first air flow flowing through the upstream or first stage of the two stages
using an air-to-air
heat exchanger, and feeding the primary airflow once cooled in the heat
exchanger of one first
stage in a refrigerant evaporator wherein. the primary airflow is further
cooled in the refrigerant
evaporator to its dew point so as to condense moisture in the primary airflow
onto cooled
surfaces of the refrigerant evaporator, whereupon the primary airflow, upon
exiting the
refrigerant evaporator of the second stage, enters the air-to-air heat
exchanger of the first stage
to cool the incoming primary airflow, thereby reducing the temperature
differential between
the temperature of the incoming primary airflow entering the first stage and
the dew point
temperature of the primary airflow in the second stage. A secondary or
auxiliary airflow,
which in one embodiment may be mixed or joined (collectively referred to
herein as being
mixed) with the primary airflow, downstream of the first and second stages so
as to increase
the volume of airflow entering a refrigerant condenser in the refrigerant
circuit corresponding
to the refrigerant evaporator of the second stage. Thus if the primary or
first airflow has a
corresponding first mass flow rate, and the secondary or auxiliary airflow has
a corresponding
second Mass flow rate, then the mass flow rate of the combined airflow
entering the refrigerant
condenser is the sum of the first and second mass flow rates, that is greater
than the first mass
flow rate in the two cooling stages. The two cooling stages may be contained
in one or
separate housings so long as the primary airflow is in fluid communication
between the two
stages. One housing 'includes a first air intake for entry of the primary
airflow. The first air
intake is mounted to the air-to-air heat exchanger.
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The air-to-air heat exchanger has a pre-refrigeration set of air conduits
cooperating at their upstream end in fluid communication with the first air
intake. The first air
intake thus provides for intake of the primary airflow into the pre-
refrigeration set of air
conduits. The air-to-air heat exchanger also has a post-refrigeration set of
conduits arranged
relative to the pre-refrigeration set of air conduits for heat transfer
between the pre-
refrigeration set of air conduits and the post-refrigeration set of air
conduits.
A first refrigeration or cooling unit (hereinafter collectively a
refrigeration unit)
such as the refrigerant evaporator cooperates with the pre-refrigeration set
of air conduits for
passage of the primary airflow from a downstream end of the pre-refrigeration
set of conduits
into an upstream end of the first refrigeration unit. The first refrigeration
unit includes first
= refrigerated or cooled (herein collectively or alternatively referred to as
refrigerated) surfaces,
for example one or more cooled plates, over which the primary airflow passes
as it flows from
the upstream end of the first refrigeration unit to the downstream end of the
first refrigeration
unit.
The already pre-cooled primary airflow is further cooled in the first
refrigeration unit below a dew point of the primary airflow so as to commence
condensation of
moisture in the primary airflow onto the refrigerated surfaces for gravity-
assisted collection of
the moisture into a moisture collector, for example a drip late or pan mounted
under or in a
lower part of the housing: The downstream end of the first refrigeration unit
cooperates with,
for passage of the primary airflow into, an upstream end of the post-
refrigeration set of air
conduits, for example to then enter the air-to-air heat exchanger so as to pre-
cool the primary
airflow before the primary airflow engages the first refrigeration unit.
Because of pre-cooling
by the heat exchanger, condensate may be collected with minimal power
requirements. A
second air-to-air heat exchanger may further increase system performance.
Collectively the
pre-refrigeration and post-refrigeration sets of air conduits form the first
cooling stage, and
collectively the plate or plates of the refrigerant evaporator form the second
cooling stage.
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An air-to-water heat exchanger may be provided cooperating with the air-to-air
heat exchanger for cooling the primary airflow wherein the primary airflow is
passed through
the air-to-water heat exchanger and the cold moisture from the moisture
collector is
simultaneously passed through the air-to-water heat exchanger so that the
moisture cools the
first airflow. The air-to-water heat exchanger may be either upstream or
downstream of the
air-to-air heat exchanger along the primary airflow.
In one embodiment a manifold or air plenum having opposite upstream and
downstream ends cooperates in fluid communication with the downstream end of
the post-
refrigeration set of conduits. That is, the upstream end of the air plenum
cooperates with the
downstream end of the post-refrigeration set of conduits so that the primary
airflow flows into
the air plenum at the upstream end of the plenum. The plenum has a secondary
or auxiliary air
intake into the plenum for mixing of the auxiliary airflow with, or addition
of the auxiliary
airflow in parallel to, the primary airflow in the plenum so as to provide the
combined mass
flow rate into the refrigerant condenser, to extract heat from the refrigerant
in the refrigerant
circuit to re-condense the refrigerant for delivery under pressure to the
refrigerant evaporator
in the second cooling stage, the refrigerant pressurized between the
refrigerant evaporator and
condenser by a refrigerant compressor (herein referred to as the compressor).
Thus the
downstream end of the plenum cooperates in fluid communication with the
refrigerant
condenser. An airflow primer mover such as a fan or blower (herein
collectively a fan) urges
the primary airflow through the two cooling stages. In embodiments wherein
both the primary
and auxiliary airflows are directed into the refrigerant condenser (herein
also referred to as the
combined airflow embodiment), a single airflow prime mover, such as a fan on
the refrigerant
condenser may be employed, otherwise, where only the auxiliary airflow flows
through the
refrigerant condenser, separate airflow prime movers are provided for the
primary and
auxiliary airflows.
In the combined airflow embodiment, a selectively actuable airflow metering
valve such as a selectively actuable damper may be mounted in cooperation with
the auxiliary
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air intake for selectively controlling the volume and flow rate of the
auxiliary airflow passing
into the plenum. An automated actuator may cooperate with the metering valve
for automated
actuation of the metering valve between open and closed positions of the valve
according to at
least one environmental condition indicative of at least moisture content in
the primary and/or
auxiliary airflows (herein "and/or" collectively referred to by the bolean
operator "or"). For
example, the automated actuator may be a temperature sensitive hi-metal
actuator or an
actuator controlled by a programmable logic controller (PLC); for example the
automated
actuator may include a processor cooperating with at least one sensor, the at
least one sensor
for sensing the at least one environmental condition and communicating
environmental data
corresponding to the at least one environmental condition from the at least
one sensor to the
processor or PLC. The at least one environmental condition may be chosen from
the group
consisting of: air temperature, humidity, barometric air pressure, air
density, air mass flow
rate. The air temperature conditioner may include the temperature of the
ambient air at the
primary airflow intake, and the temperature of the primary airflows entering
and leaving the
second cooling stage.
The processor regulates the first and/or second airflows, for example
regulates
the amount of cooling in the refrigeration unit, so that the air temperature
in the first
refrigeration unit is at or below the dew point of the primary airflow, but
above freezing. The
processor may calculate the dew point for the primary airflow based on the at
least one
environmental condition sensed by the at least one sensor.
The airflow prime mover may be selectively controllable and the processor may
regulate the primary, auxiliary or combined airflow so as to minimize the air
temperature of
the primary airflow from dropping too far below the dew point for the primary
airflow to
minimize condensation within the heat exchanger, and so as to optimize or
maximize the
volume of moisture condensation in the refrigeration unit.
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At least one filter may be mounted in cooperation with the water condenser
housing. For example, at least one air filter such as a HEPA .filter may be
mounted in the flow
path of the first airflow. A water filter may be provided for filtering water
in the moisture
collector. The air filters may include an ultra-violet radiation lamp mounted
in proximity to,
so as to cooperate with, the primary airflow path or the moisture collector.
For example the air
filter and the water filter may include a common ultra-violet radiation lamp
mounted in
proximity to so as to cooperate with both the primary airflow path and the
moisture collector.
in upstream-to-downstream order, the first refrigeration unit may be adjacent
0 the heat exchanger, the heat exchanger may be adjacent the plenum, the
plenum may . be
adjacent the refrigerant condenser, and the refrigerant condenser may be
adjacent the airflow
prime mover. These elements may be inter-leaved in closely adjacent array.
Brief Description of the Drawings
Figure .1 is, in perspective view, one embodiment of the water condenser
according to the present invention.
Figure 2 is a sectional view along line 2-2 in Figure 1.
Figure 2a is an enlarged view of a portion of Figure 2.
Figure 2b is a sectional view along line 2b-2b in Figure 2.
Figure 3 is a sectional view along line 3-3 in Figure 1.
Figure 3a is an enlarged view of a portion of Figure 3.
Figure 3b is an enlarged view of a portion of Figure 3a.
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Figure 3c is, in perspective view, the internal air conduits of the upstream
side
of manifold of the water condenser of Figure 1.
Figure 4 is a sectional view along line 4-4 in Figure 1.
Figure 5 is the view of Figure 3 in an alternative embodiment wherein the
airflow manifold feeding the refrigerant condenser is partitioned between the
primary and
auxiliary airflows.
,
Figure 6 is a diagrammatic view of the pre-cooling and condenser cycle and
closed loop refrigerant circuit according to the embodiment of Figure 1.
Figure 6a is the view of Figure 6 showing an air-to-water heat exchanger
downstream of the air-to-air heat exchanger.
Figure 6b is the view of Figure 6 showing an air-to-water heat exchanger
upstream of the air-to-air heat exchanger.
Figure 7 is, in partially cut away front right side perspective view, an
alternative embodiment of the present invention wherein two separate fans draw
the primary
and auxiliary airflows through the evaporator and condenser respectively.
embodiment of Figure 7.Figure 8 is, in partially cut away front left side
perspective view, the
Figure 7. Figure 9 is, in partially cut away rear perspective
view, the embodiment of
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Figure 10 is a partially cut away rear perspective view of the embodiment of
Figure 9.
Figure 10a is a sectional view along line 10a-10a in Figure 10.
Figure 11 is, in partially cut away perspective view a further alternative
embodiment of the present invention wherein the primary airflow passes through
an air-to-
water heat exchanger.
Figure 12 is a graph of Temperature vs. Time showing the interrelation of
Evaporator Temperature, Processed Air Temperature, Relative Humidity (RH)%,
Dew Point
Temperature, and Environmental Temperature in the device of Figure 1.
Detailed Description of Embodiments of the Invention
With reference to the drawings wherein similar characters of reference denote
corresponding parts in each view, in one preferred embodiment of the present
invention, a fan
12 draws a primary airflow along an upstream flow path A through an upstream
refrigerant
evaporator 14, through an air-to-air heat exchanger 16, and in an alternative
embodiMent also
through an air-to-water heat exchanger using cold water collected as
condensate from
evaporator 14 (better described below), cooperating with an air intake 18 of
upstream flow
path A, then through a manifold 20 where ambient air is drawn in as auxiliary
airflow in
direction B through auxiliary air intake 22. The primary airflow enters
manifold 20 in
direction C upon leaving heat exchanger 16. The primary and auxiliary
airflows, in the
embodiment of Figure 3, mix in manifold 20 then flow in direction D through a
downstream
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refrigerant condenser 24 and finally flow through fan 12 so as to be exhausted
and heated
exhaust in direction E.
The primary airflow is pre-cooled in the air-to-air heat exchanger, and also
in
the air-to-water heat exchanger in the alternative embodiment. Humidity in the
ambient air
drawn in as the primary airflow through intake 18 is condensed in refrigerant
evaporator 14.
Water droplets which condense are gravity fed in direction F into a collection
plate, pan or
trough 26 for outflow through spout 26a. The addition of ambient air drawn in
as the auxiliary
airflow in direction B into manifold 20 provides the higher volumetric airflow
rate needed to
efficiently operate refrigerant condenser 24.
In operation, the primary airflow is drawn in through the upstream air intake
18
of evaporator 14 in direction A and passes between the hollow air-to-air heat
exchanger plates
30. Depending on the embodiment of the present invention, an air-to-water heat
exchanger 90
may cooperate with air-to-air heat exchanger 16 and there may be one, two,
three or more
plates 30 in heat exchanger 16.. Plates 30 are preferably parallel and are
spaced apart to form
flow channels therebetween, and between the outermost plates 30a and the walls
32a of the
housing 32 of the heat exchanger. Within evaporator. 14, in the two evaporator
plate
embodiments illustrated, plates 34 are refrigerated by the evaporation of
refrigerant flowing
into cooling coils 34a. Plates 34 are optimally cooled to a temperature which
will cool the
primary airflow to just below its dew point such as seen plotted from
experimental data in
Figure 12 so as to condense water vapour in the primary airflow onto the
surfaces of the plates
and coils without causing the water vapour to form ice. For example, the
primary airflow
exiting evaporator 14 in direction H. so as to enter heat exchanger 16, may be
cooled to 40'
Fahrenheit.
Once the primary airflow has passed between plates 30, and between plates 30a
and the walls 32a of housing 32 (collectively, generically the pre-
refrigeration set of air
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conduits), the primary airflow is turned one hundred eighty degrees in
direction I by and
within an end cap manifold 36 which extends the length of the upper ends of
plates 30.
Plates 30 themselves are rigidly supported in parallel spaced apart array
sandwiched by and between planar end plates 38. The end plates have an array
of apertures
38a therethrough. The apertures align with the open ends of sealed conduits
30b through the
plates, as best seen in Figures 3, 3a and 3b, so that, once the airflow has
turned one hundred
eighty degrees in direction H through upstream side manifold 40, the airflow
then passes in
direction J through apertures 38a and along the length of conduits 30b (the
post-refrigeration
set of air conduits) so as to exit from the corresponding apertures 38a
downstream in the
opposite end plate 38'. In particular, side manifold 40 in the illustrated
embodiment of Figure
3c, which is not intended to be limiting, segregates airflow in direction H
into three flows Hi ,
H1 and 113 so as to enter into corresponding conduits 30b, themselves arranged
in three banks
30b1, 30b2 and 30b3 arranged vertically one on top of the other as seen in
Figure 2. Fences 40b
divide airflows HI, 1712 and H3 from one another and align the airflows with
their
corresponding bank of sealed conduits 30b, so that airflows HI, 141 and H3 are
aligned for flow
into, respectively, conduit banks 30b1, 30b2 and 301)3. Fences 40b also align
with plates 34 so
as to partially segregate the infeed to airflows Hi, H2 and H3 to come from,
respectively,
between the outside plate 34 and the outside wall 14a, between the inside and
outside plates
34, and between the inside plate 34 and the inside wall 14b. A lower cap 40a
seals the end of
pan 26 and channels moisture collected from side manifold 40 into pan 26,
better seen in
Figure 2b. Air-to-air heat transfer in direction K occurs through the solid
walls of plates 30 so
that the primary airflow in conduits 30b cools the primary airflow between the
plates.
Upon leaving the apertures 38a' in end plates 38', the airflow is again turned
approximately one hundred eighty degrees in direction C by and within
downstream side
manifold 42 which extends the height of end plate 38'. Side manifold 42
directs airflow into
manifold 20 through a port 44 leading into the upstream end of manifold 20. An
ambient air
intake 22 feeds ambient air in direction B into manifold 20 so as to, in one
combined airflow
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CA 02516002 2005-07-29
embodiment, mix with the airflow from heat exchanger 16 with ambient air from
auxiliary air
intake 22. The flow rate of the auxiliary airflow through intake 22 is
selectively regulated by
actuation of damper 20a (shown in Figure 3 in its closed position in dotted
outline and in its
open position in solid outline). The mixed airflow is then drawn in direction
D into refrigerant
condenser 24 so as to pass between the louvers 24a or coils or the like.
Condenser 24
condenses refrigerant flowing in lines 46a (illustrated diagrammatically - in
dotted outline in
Figure 4) once compressed by compressor 46. The combined airflow then enters
the in-line
fan 12 and exhausts from the fan in direction E.
Atmospheric air enters intake 18 in direction A through screen 50, passing
through pre-filter 52, then through a high quality filter, such as HEPA filter
54. Air flow.
leaving condenser 24 may pass through another filter 56. Filter 56 inhibits
contaminates from
entering the fan and thus keeps contaminants from getting into evaporator 14.
Once the
primary airflow has been processed through the two cooling stages of,
respectively, heat
exchanger 16 and refrigerant evaporator 14, the primary airflow may not be
sufficiently cool to
assist in the refrigerant cooling in refrigerant condenser 24. Thus the
primary airflow may be
exhausted entirely from the system without flowing through condenser 24
without
significantly affecting performance or where the primary airflow is somewhat
cool, it may be
used to assist in cooling condenser 24. If the air that has passed through the
evaporator 14 and
heat exchanger 16 is exhausted upstream of condenser 24, the condenser 24 will
draw its own
air stream, that is the auxiliary airflow, directly from the ambient air
outside the system. The
use of the two air streams, primary and auxiliary has advantages in allowing a
significant
increase in airflow through the condenser versus the evaporator.
A controller 48 may do multiple tasks and the system may require multiple
controllers if it is not beneficial or practical to build them all into the
same unit. The controller
48 may be designed to accommodate a varying power input such as would be the
case if the
unit was hooked up directly to a photovoltaic panel. Controller 48 may also
ensure that the
refrigeration system pressures are maintained.
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CA 02516002 2005-07-29
There are two pressures involved in a refrigeration system such as is employed
in this design. These are the suction pressure (low side) and the discharge
pressure (high side).
For optimal performance the low side or suction pressure may be approximately
30psi. The
high side or discharge pressure is much harder to control and may be within
the .120psi to
200psi range for optimal performance. With a normal refrigeration system the
high side
pressure is much easier to control using conventional refrigeration controls,
and poses little
concern. With a system such as this, that is under constant changing load with
large
fluctuations in both temperature and humidity, the pressures are prone to
change and can
quickly move outside of the optimal range. This can cause damage to the system
as if the
discharge pressure gets to high (over 250psi) it may be very hard on the
system and can cause
internal damage to the valves in the compressor, the insulation on the
electrical wiring, and
may even cause the formation of waxes, as well as decreasing the overall
efficiency of the
system. These pressures may be controlled to some degree by controlling the
pressures within
the system and through controlling the flow of refrigerant. The high side or
discharge may be
controlled by regulating the quantity and temperature of the air that passes
through the
condenser. If the discharge pressure is too low (below 120psi) the cooling
system becomes
compromised and functions below its capability. In this case the controller is
designed to turn
the -fan off and allow the pressure to rise. If the pressure gets too high the
controller will turn
the fan on and the pressure will drop. This is a simple and inexpensive way to
control the
system discharge pressure.
Controller 48 may also find the optimal airflow rate through the condenser so
as
to moderate the discharge (also called backpressure) to an acceptable range
(150psi may be
optimal). In this design the fan is kept at the optimal speed rather than
turning off and on, so
as to ensure proper system pressures and optimal operation of the
refrigeration system.
In ensuring that an ideal operation of the device is maintained, different
systems
may be employed. They are as follows.
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CA 02516002 2005-07-29
The ideal location within the system will be determined for where the internal
airflow should be reaching its dew point. This location might be between the
heat exchanger
and the evaporator plates (first pass). A controller with sensors monitors
environmental
conditions and calculates internally what the dew point is. Sensors are placed
within the
system such as mentioned above, that allow the controller to monitor the
sensors, thereby
determining where the temperature is with respect to dew point. Thus, if
optimal system
function is to create dew point at this sensor the controller will slow down
or speed up the fan
in a continual effort to optimize the system. In another embodiment a pressure
differential
gauge may be used to offer feedback to the controller assisting in its
function to optimize the
airflow. The present system is designed to keep the airflow just below dew
point and to track
dew point continuously as conditions change. As seen in the test data set of
Figure 12, the
dew point is continuously tracked by the processed air temperature ensuring
optimal operation.
In an alternative embodiment as seen in Figures 7-10 and 10a, the primary and
auxiliary airflows are entirely separate. Whereas in the previously describe
embodiment, the
primary airflow after passing through the air-to-air heat exchanger wherein
the lowered
temperature of the primary airflow leaving the refrigerant evaporator is used
to pre-cool the
incoming primary airflow rather than be wasted, and the primary airflow then
flowing into the
manifold wherein it is mixed with the auxiliary airflow so as to provide the
increased mass
flow volume for the refrigerant condenser, in this embodiment, control of the
primary airflow
is provided by a separate fan for increased accuracy of control of the primary
airflow through
the two cooling stages namely the heat exchanger and refrigerant evaporator.
Thus as may be seen in the illustrations, fan 60 draws auxiliary airflow
through
refrigerant condenser 62 in direction M via intake 64. As before, the
refrigerant condenser is
in the same refrigeration circuit as the refrigerant evaporator, that is, is
in the same
refrigeration circuit as the second cooling stage. As before, an air-to-air
heat exchanger
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CA 02516002 2005-07-29
provides the first cooling stage. Thus the primary airflow, as before, enters
the heat exchanger
prior to entry into the refrigerant evaporator. In particular, primary airflow
enters air-to-air
heat exchanger 66 in direction N through a lower intake 68 having passed
through air filters as
previously described (riot shown). The primary airflow passes through hollow
conduits 66a
across the width of the heat exchanger, exiting conduit 66a in direction P so
as to be turned.
one hundred eighty degrees in end manifold. 70. The primary airflow then flows
between
refrigerant evaporator plates 72 in direction Q wherein the primary airflow is
cooled below it's
dew point without freezing. Moisture thus condenses out of the primary airflow
onto plates 72
and is harvested through a spout 74 into a collection pan or the lik.e (not
shown).
The primary airflow exits from the refrigerant evaporator through slot 76 and
travels in direction R downwards between conduits 66a so as to exit heat
exchanger 66 in
direction S through slot 78. The primary airflow is then drawn through fan
housing 80 and fan.
82 so as to exit as exhaust from fan 82 in direction T.
The de-linking of the primary and auxiliary airflows so as to require separate
fans, respectively fans 82 and 60, provide for condenser 62 functioning at a
greater capacity
without affecting optimization of the balance of the cooling between the first
and second
cooling stages of, respectively, the heat exchanger 66 and the evaporator
plates 72. Thus the
lower volume fan 82 may be controlled by a processor (not shown) to determine
the current
environmental conditions affecting optimization of cooling and condensation
for example by
varying the power supplied to fan 82 to thereby control the velocity and mass
flow rate of the
primary airflow through the two cooling stages. Thus the primary airflow may
be drawn
through the cooling stages at a velocity which is not so high as to affect the
maximum
condensation of moisture, and not too low so as to waste energy in cooling the
primary airflow
too far below the dew point. Thus by monitoring environmental conditions, for
example the
humidity and temperature, the fan speed of fan 82 may be selectively
controlled to optimize
production of condensation regardless of ambient environmental conditions.
Thus in a very
humid environment, fan 82 will be powered to draw a higher mass flow rate of
the primary
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CA 02516002 2005-07-29
airflow through the two cooling stages, whereas in lower humidity conditions
the primary
airflow will require more time to optimize the condensation and thus slower
fan speeds may be
used to provide for optimized condensate production.
In the further embodiment of Figure 5 a partition 100 partitions manifold 20
so
that the primary and secondary airflows do not mix. For example, partition 100
may bisect the
intake into refrigerant condenser 24. Otherwise, partition 100 may be mounted
relative to the
intake into refrigerant condenser 24 so as to provided for a g-eater volume of
auxiliary airflow
in direction D' flowing through condenser 24. The air speed velocity and mass
flow rate of the
primary airflow through the two cooling stages of the heat exchanger and
refrigerant
evaporator respectively, may be, for example, controlled by selectively
positioning the
position of partition 100 relative to condenser 24 or otherwise by, in
conjunction with, the use
of airflow dampers or other selectively controllable airflow valves.
The appropriate processing of ambient air provides for optimal operation of
the
condenser unit. While conventional condensers may simply drive high volumes of
air through
a cooling system (typically just an evaporator without a heat exchanger),
these systems have
not accommodated a system designed for power efficiency as is in the present
invention which
employs techniques to extract the maximum quantity of water with the least
power
requirements. This may be accomplished in a number of ways, as follows.
Environmental conditions are monitored by the system and at an appropriate
point, in the system, such as between the heat exchanger and the evaporator
(first pass) the
temperature relative to dew point is monitored. If the air at this point is
too far above dew
point the fan that draws air through this section of the unit may decrease its
speed thus slowing
the air and allowing more time for the air to cool prior to reaching the
evaporator plates. If the
air at this point is below dew point then the system may increase the fan
speed and continue to
optimize the airflow stream. Other conditions throughout the device may be
monitored as well
and this information may be used by controller 48 to further tune the device.
Humidity levels
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CA 02516002 2005-07-29
leaving the system may be used as a means to determine exactly how much water
has been
extracted from the air and with this information, the system may modify its
'configuration thus
ensuring optimal performance.
In the alternative embodiment of Figures 6b, 11 and 11 a, air-to-water heat
exchanger 90 is mounted upstream of the air-to-air heat exchanger along the
primary airflow.
Water collected in moisture collector 26 is directed for example by conduit
26a into water
reservoir 90a from which the water may be collected for end use. The water in
reservoir 90a is
chilled, having just been condensed into and recovered from the evaporate
plates. Thus the
primary airflow passing through air conduits 90b in direction A' is cooled by
the water cooling
the conduits 9011 before the primary airflow enters the air-to-air heat
exchanger for further pre-
cooling as described above. This further improves the efficiency of the
condenser as it takes
advantage of the cold temperature of the collected water.
In one embodiment, various parts and components of the unit may be either
constructed with Titanium Dioxide or my simply be coated with Titanium
Dioxide. Using this
material to construct various parts for the device, or using this material as
a coating on these
parts, will ensure that these components are kept clean and free of
contaminates and that the
water source created by the device is kept free of unwanted contaminates.
Virtually any of the
internal components may be made of this inexpensive and abundant material. In
addition,
either all the material that composes the storage container or just the inner
lining may be made
of this material as a means to ensure that that water source is kept clean and
free of unwanted
contaminates.
This material may be used as an antimicrobial coating as the Photocatalytic
activity of titania results in a thin coating of the material exhibiting self
cleaning and
disinfecting properties under exposure to ultra-violet (UV) radiation. These
properties make
the material ideal for application in the construction of our water
condensation system helping
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CA 02516002 2005-07-29
to keep air and water sources clean and free of contaminates while as well
offering the benefits
of self repair should a surface be scratched or compromised.
Titanium dioxide, also known as titania, is the naturally occurring oxide of
titanium, chemical formula Ti02. Approved by the food testing laboratory of
the United States
Food and Drug Administration (FDA), Titanium Dioxide is considered a safe
substance and
harmless to humans.
Scientific studies on photocatalysis have proven this unique but abundant
substance to be anti-bacterial, anti-viral and fungicidal making it ideal for
self cleaning
surfaces and may be used for deodorizing, air purification, water treatment,
and water
purification.
As Titanium dioxide is a semiconductor and is chemically activated by light
energy, appropriate lighting sources may be added at various strategic points
throughout the
'device to ensure that the air and water sources are kept clean and free of
unwanted substances.
Some of the most beneficial places throughout the system that might use this
TiO2 exposed to
UV radiation are the heat exchanger, evaporator plates, and the storage
container, however
virtually all surfaces that come in contact with either the air or the water
source may be
constructed with Titanium Dioxide. One strategic place for the lighting source
might be
between the heat exchanger and the evaporator plates using reflective material
to ensure that
the light radiates through both theses sections of the device made, or coated
with Ti02.
As a pure titanium dioxide coating is relatively clear, this substance may be
used for the inner lining of tubing that carries the water from the evaporator
plates to the
storage container and may become part of the UV purification system. This
material has an
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CA 02516002 2005-07-29
extremely high index of refraction with an optical dispersion higher than
diamond so in order
to enhance its desired effects, coiled tubing that surrounds the light source,
may be encased in
a reflective material so as to ensure that light is given an adequate
opportunity to come in
contact with the surface of the material and thus create the desired effect.
In applications where this UV and Titanium purification system is used inside
of a storage container of some sort, an opening may be situated at the bottom
of the reflective
encasement such that light will escape to offer these same desire effects to
occur within the
storage container. Alternatively, a separate light may be used within the
storage container
assuming it is not practical for various applications to use only one light to
serve this purpose.
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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