Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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WATER CONDENSOR APPARATUS
FIELD OF THE INVENTION
The present invention broadly relates to methods and apparatus for condensing
water from
ambient air and collecting the condensed water. The apparatus in at least one
form provides
a means for generating potable water for consumption or other purposes and
finds particular
application in areas where potable water supplies are limited.
BACKGROUND OF THE INVENTION
In many locations around the world access to a fresh potable water supply is
limited, forcing
many to use water for everyday needs that would not generally be deemed
suitable for such
use. Indeed, many water supplies are contaminated or polluted and in order to
use the
water safely, it is necessary for the water to be boiled or treated in some
other way.
While yachts and ships carry their own water supplies during a voyage, it is
often necessary
to restrict daily usage of the available water due to access to fresh water
supplies other than
rainfall being unavailable. Similarly, mining operations or military camps in
remote locations
and, for example, island resorts, all have a need for fresh water.
Water, of course, has thousands of uses in addition to being required to
sustain life. Such
uses include washing and use in industrial processes amongst others. In areas
or locations
where fhe supply of water is limited, it is desirable to have access to
regular supplies of fresh
water. While supplies can be replenished by rain water, rainfall can be
variable and
insufficient. Moreover, the cost of transporting fresh water to remote
locations can be
expensive.
In United States patent No. 6,156,102 there is disclosed apparatus and methods
for collecting
water from ambient air involving passing the air into contact with a
hygroscopic solution.
The hygroscopic solution absorbs the moisture from the air, which is
subsequently
evaporated from the hygroscopic solution and collected. The evaporation of the
moisture is
achieved by heating the hygroscopic liquid or by evaporating the moisture
under vacuum.
A similar arrangement involving directing ambient air into contact with a
sorbent material
for absorption of moisture from the air prior to separation and collection of
the absorbed
moisture is described in United States patent No. 6,336,957.
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2.
Apparatus for condensing water from ambient air comprising a refrigeration
system
incorporating an electric compressor are described in European patent No.
0597716 and
United States patent No. 5,857,344. The refrigeration systems cool ambient air
by
compression and subsequent expansion of a refrigerant to effect condensation
of the water
from the air. In each of these apparatus, the water is collected from the air
and dispensed in
the one location.
SUMMARY OF THE INVENTION
In a first aspect of the present invention there is provided a modular system
for collecting
water from ambient air and dispensing the collected water, the system
comprising:
a condenser unit for condensing the water from the ambient air and collecting
the
condensed water, and including at least one condensation surface disposed for
contact with
the ambient air;
a refrigeration system for cooling the condensation surface to, or below, the
dew
point of the ambient air to effect the condensation of the water from the
ambient air onto the
condensation surface for collection, the refrigeration system being housed in
the condenser
unit and incorporating a compressor for compressing a refrigerant vapour and a
condenser
for condensing the compressed refrigerant vapour into liquid refrigerant; and
at least one dispenser unit adapted for being located remotely from the
condenser
unit for receiving the condensed water from the condenser unit and dispensing
the water,
wherein the dispenser unit is adapted for storing the water and/or
recirculating at least
some of the water.
The dispenser unit may be demountable from the condenser unit for being
located remotely
from the condenser unit if desired. That is, an embodiment of the modular
system may be
provided as a single unit for condensing the water from the ambient air and
dispensing the
water in the one location, or the dispenser unit can be detachably removed
from the
dispenser unit and located at another location. In an alternative embodiment,
the dispenser
unit and the condenser unit are provided as entirely separate units.
As the water can be dispensed remotely from where it is condensed from the
ambient air and
collected, the condenser unit can be located outside of a building where it is
exposed to
prevailing atmospheric humidity conditions, while the dispenser unit may be
located within
the building. As the ambient environment in many buildings is air-conditioned
and the
humidity in the building controlled, locating the condenser unit outside
enables water
production to be maximised. Locating the condenser unit outside also removes
any noise
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3.
associated with the operation of the refrigeration system of the condenser
unit to outside the
building.
Accordingly, in another aspect of the present invention, there is provided a
modular system
for collecting water from ambient air, the system comprising:
a condenser unit for condensing the water from the ambient air and collecting
the
condensed water, and including at least one condensation surface disposed for
contact with
the ambient air;
a refrigeration system for cooling the condensation surface to, or below, the
dew
point of the ambient air to effect the condensation of the water from the
ambient air onto the
condensation surface for collection, the refrigerant system being housed in
the condenser
unit and including a compressor for compressing a refrigerant vapour and a
condenser for
condensing the eompressed refrigerant vapour into liquid refrigerant; and
at least one dispenser unit located remotely from the condenser unit for
receiving the
condensed water from the condenser unit and dispensing the water, wherein the
dispenser
unit is adapted for storing the water and/ or recirculating at least some of
the water.
Preferably, the condenser will be arranged for contact with ambient air
flowing from the
condensation surface for cooling the refrigerant vapour to facilitate the
condensing of the
refrigerant vapour.
Preferably, the condenser unit will also include a water circulation system,
comprising a
holding tank for receiving the collected water, and a pump for pumping the
water from the
holding tank to the dispenser unit. Preferably, the water circulation system
will incorporate
at least one ultraviolet (LTV) light treatment unit for treating the water in
the condenser unit
with ultraviolet light to kill or inactivate bacteria and/or other
microorganisms that may be
present in the water, prior to the water being pumped by the pump from the
condenser unit
to the dispenser unit.
Preferably, the dispenser unit will be provided with at least one indicator
for providing an
indication of a corresponding operational parameter of the modular system. In
a particularly
preferred embodiment, the dispenser unit will be provided with a plurality of
such
indicators, each indicator providing an indication of a different operational
parameter,
respectively. For instance, an indicator may provide an indication of water
availability from
the condenser unit, low water level in the condenser unit, air or water filter
status in the
condenser unit to indicate whether the filter requires cleaning or replacing,
or other such
operational parameter or status.
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The dispenser unit may comprise a dispenser body and a storage reservoir for
storing water
received from the condenser unit, wherein the storage reservoir is detachably
removable
from the dispenser body. Preferably, the storage reservoir and the dispenser
body will mate
together such that the storage reservoir is retained in position by the
dispenser body.
Typically, the storage reservoir will have a dispensing valve for dispensing
the water. In a
particularly preferred embodiment, the dispenser body will also be adapted for
dispensing
water on demand following removal of the storage reservoir from the dispenser
body.
Moreover, an embodiment of the invention may comprise a control system for
controlling
flowrate of the ambient air into contact with the condensation surface, the
control system
comprising:
a temperature sensor for indicating temperature of the ambient air flowing
from the
condensation surface; and
control means for monitoring the temperature indicated by the temperature
sensor
and adjusting the flowrate of the ambient air flowing into contact with the
condensation
surface in response to the monitored temperature, to promote condensation of
the water
from the ambient air onto the condensation surface.
In addition, the condenser unit may be provided with at least one adjustable
air intake
operable by the control system to allow ambient air to flow to the condenser
by-passing
contact with the condensation surface such that a flowrate of ambient air
flowing into contact
~0 with the condenser is adjusted relative to that of ambient air flowing from
exterior of the
condensation unit into contact with the condensation surface. This allows
increased air flow
past the condenser for cooling the condenser to enable refrigerant vapour in
the condenser
to condense into liquid refrigerant, without increasing the rate of flow of
the ambient air
from the condensation surface and thereby adversely affecting condensation of
water from
the ambient air onto the condensation surface.
Preferably, the control system will also comprise a further temperature sensor
arranged to
monitor temperature of the refrigerant vapour in the condenser and a pressure
sensor for
measuring pressure within the condenser, the control means being adapted to
assess the
temperature monitored by the further temperature sensor and the pressure
measured by the
pressure sensor, and operating the adjustable air intake in the condenser unit
to alter the
flow rate of the ambient air flewing to the condenser.
In another aspect of the present invention there is provided a dispenser unit
for dispensing
water received from a stand alone water collection unit, the dispenser unit
comprising at
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5.
least one valve for dispensing the water and being adapted for storing the
water until use
and / or recirculating at least some of the water to the water supply unit.
In yet another aspect of the present invention there is provided water
collection apparatus
for collecting water from ambient air, the apparatus comprising:
at least one condensation surface disposed for contact with the ambient air;
at least one adjustable air intake; and
a refrigeration system for cooling the condensation surface to, or below, the
dew
point of the ambient air to effect the condensation of the water from the
ambient air onto the
condensation surface for collection, the refrigerant system including a
compressor for
compressing a refrigerant vapour and a condensor for condensing the compressed
refrigerant vapour into liquid refrigerant;
wherein the condensor is arranged for contact with ambient air flowing from
the
condensation surface, and the air intake is operable to allow ambient air to
flow to the
condensor by-passing contact with the condensation surface such that a
flowrate of ambient
air flowing into contact with the condensor is adjusted relative to ambient
air flowing from
exterior of the apparatus into contact with the condensation surface.
In yet another aspect of the present invention, there is provided a water
treatment device for
treating water with ultraviolet light, the apparatus comprising:
an ultraviolet light source for providing the ultraviolet light;
a hollow member defining a treatment chamber with an inlet for entry of the
water
into the treatment chamber and an outlet for passage of the water from the
treatment
chamber, and which is transparent to the ultraviolet light; and
an inducer element arranged for inducing spiral flow of the water along the
treatment chamber;
wherein the ultraviolet light source is arranged for irradiating the water
with the
ultraviolet light as the water flows along the treatment chamber.
The spiral flow of the water along the treatment chamber mixes the water and
maximises
exposure of the water to the UV light and thereby treatment of the water with
the W light.
Preferably, the inducer element will comprise a stationary spiral element
arranged within the
treatment chamber in a fixed position for inducing the spiral flow of the
water along the
treatment chamber as the water flows past the spiral element. In a
particularly preferred
embodiment, the spiral element will comprise a plate twisted into a spiral
with a
longitudinal axis directed along the treatment chamber. Alternatively, the
inducer element
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may comprise a rotor which is rotatably mounted in the treatment chamber for
being rotated
as the water flows past the rotor.
Preferably, the water treatment device will further comprise a holder which
holds the UV
light source and the hollow member defining the treatment chamber in position
alongside
one another.
Preferably, the water treatment device will also be provided with a reflector
for reflecting
incident UV light from the ITV light source into the treatment chamber.
Typically, the
reflector will be arranged in the holder behind the IJV light source and lie
alongside the UV
light source for reflecting the UV light forward into the treatment chamber.
Condensing water from ambient air provides a way of supplementing fresh or
stored water
supplies in remote or extreme locations where fresh water is scarce or
otherwise unavailable,
and may reduce reliance on, or the need for, water to be transported to such
locations.
Similarly, where it is necessary to carry water supplies such as on a ship or
boat during a
voyage, condensing water from ambient air provides an alternative source of
water during
travel and so allows less reliance to be placed on stored water. Indeed, by
being able to
condense water from ambient air, stores of water may be reduced. In addition,
condensing
water from air provides some certainty as to the quality of the water, and
provides a source
of water in areas where there is doubt as to the quality of the existing water
supplies or the
available water is known to be polluted or contaminated, or is otherwise not
suitable for the
intended purpose of the water. Accordingly, one or more embodiments of the
present
invention find application in a number of practical situations.
Throughout this specification the word "comprise", or variations such as
"comprises" or
"comprising", will be understood to imply the inclusion of a stated element,
integer or step,
or group of elements, integers or steps, but not the exclusion of any other
element, integer or
step, or group of elements, integers or steps.
All publications mentioned in this specification are herein incorporated by
reference. Any
. discussion of documents, acts, materials, devices, articles or the like
which has been included
in the present specification is solely for the purpose of providing a context
for the present
invention. It is not to be taken as an admission that any or all of these
matters form part of
the prior art base or were common general knowledge in the field relevant to
the present
invention as it existed in Australia or elsewhere before the priority date of
each claim of this
application.
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7.
The features and advantages of the present invention will become further
apparent from the
following description of preferred embodiments of the present invention
together with the
accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIGURE 1a is a perspective view of a condensor unit and a dispenser unit of a
modular
system embodied by the invention for condensing water from ambient air and
dispensing
the collected water;
FIGURE 1b is a perspective view of another dispenser unit embodied by the
invention for
receiving water from the condensor unit of Fig.1a;
FIGURE 2a is a perspective view of a further embodiment of a modular system of
the
invention;
FIGURE 2b shows the modular system of Fig. 2a with the storage bottle of the
dispenser unit
removed;
FIGURE 3a is a perspective view of a further embodiment of a dispenser unit of
the
invention;
FIGURE 3b is a perspective view of the dispenser unit of Fig. 3a with the
storage bottle
removed;
FIGURE 4 is a schematic diagram showing components of the condensor unit of
Fig.l;
FIGURE 5 is a schematic diagram of the refrigeration system of the dispenser
unit of Fig. 1;
FIGURE 6 is a schematic diagram showing a water circulation system of the
dispenser unit
of Fig.1;
FIGURES ~ to 9 are flow diagrams illustrating the operation of another
embodiment of the
invention;
FIGURE 10 is a partial side view of an ultraviolet light treatment unit for
irradiating water
collected by the dispenser unit of Fig.1 with ultraviolet light;
FIGURE 11 is a partial side view of an inducer element for introducing spiral
flow into water
flowing through the kill chamber of the ultraviolet light treatment unit of
Fig. 10;
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FIGURE 12 is a plan view of a rotor for generating spiral flow of water
collected by the
dispenser unit of an embodiment of the invention, for facilitating treatment
of the water with
ultraviolet light;
FIGURE 13 is a plan view of the holder of the ultraviolet light treatment unit
of Fig. 10;
FIGURE 14 is a schematic view showing indicators for indicating the status of
various
operational parameters of a modular system for condensing water from ambient
air
embodied by the invention;
FIGURE 15 is a schematic view of water level sensing apparatus;
FIGURE 16 is a circuit diagram of a sensing circuit of the water level sensing
apparatus of
Fig. 15; and
FIGURE 17 is a schematic view of a yet further dispenser unit embodied by the
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A condenser unit 10 of an embodiment of a modular system 12 for condensing
water from
ambient air is shown in Fig. 1a together with a dispenser unit 14. The
condenser unit 10
houses a refrigeration system 16 which cools ambient air entering the housing
18 of the
condenser unit through vent openings 20 to, or below, the dew point of the
water, causing
water vapour in the air to condense within the condenser unit 10 where it is
collected. Water
collected in the condenser unit is subsequently pumped through a feed conduit
indicated by
numeral 22 to the dispenser unit 14 for being dispensed when required. The
condenser unit
10 is located externally of the building generally indicated by numeral 24,
and is thereby
exposed to the prevailing atmospheric humidity conditions for maximising
collection of
water from the ambient air.
The dispenser unit 14 shown in Fig. 1a is a wall mounted unit located
internally in the
building and comprises a dispenser body 26, and a storage reservoir in the
form of a bottle 28
with a dispensing valve (not shown) located in a lower region of the bottle
which is operable
to dispense water from the bottle. The storage bottle has an upper recess
indicated by
numeral 30 which is contoured to match the front region 32 of the dispenser
body, and an
opening defined in the topside thereof for receiving water from the dispenser
body. The
dispenser unit 14 and storage bottle 28 mate together such that the storage
bottle is retained
in position on the dispenser body. The dispenser body incorporates a primary
dispensing
valve operable by a user to dispense water on demand into the storage bottle
through the
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9.
opening defined in the topside of the bottle, or into a cup or other
receptacle placed under
the dispenser unit following removal of the bottle. The primary dispensing
valve may
comprise any suitable conventional mechanical or electrically operated (eg
solenoid) valve
system. Accordingly, the dispenser unit 14 provides for dual operation. That
is, firstly
collection and subsequent dispensing of water from the storage bottle 28 under
gravity and
secondly, removal of the storage bottle and dispensing of water on demand
directly from the
dispenser body.
The dispenser unit 14 shown in Fig. 1b is not provided with a storage bottle
but rather, has a
downwardly projecting base 36 with a rest 38 for the placement of a cup to be
filled with
water from the dispenser body. As with the dispenser unit shown in Fig.1a, the
dispenser
body 26 is provided with a valve operable to release water from the dispenser
body under
gravity into the cup or other receptacle when placed on the rest 38. Each
dispenser body of
these apparatus comprises an internal water storage compartment for storing a
predetermined amount of water from the condensor unit and from which the water
flows
upon operation of the main valve by the user into the storage bottle 28 or cup
when
provided.
An inlet allows water to flow into the water storage compartment and pool
within the
dispenser body until required by the user. An outlet is provided at an
elevated position
relative to inlet, through which water returns from the dispenser body to the
condensor unit
through a return conduit upon the water level in the storage compartment
rising to the
outlet. Water is, therefore, continuously recirculated from the dispenser body
to the
condensor unit as further described below.
Another embodiment of a modular system of the invention for condensing water
from
ambient air is illustrated in Fig. 2a. As shown, the dispenser unit 14 is
mounted on the
condensor unit 10 and is detachable therefrom as a single unit for being
located remotely
from the condensor unit if desired. As with the dispenser unit shown in Fig.
1a, the storage
bottle is removable from the dispenser body such that the water may be
independently
dispensed on demand from the dispenser body itself. Hence, the dispenser body
may be
used independently of the storage bottle 28 as indicated in Fig. 2b. In this
embodiment, the
recess 40 defined in the condensor unit 10 for reception of the storage bottle
28 provides a
platform 42 on which a cup or other receptacle may be placed before being
filled with water
from the dispenser body 26. The platform 42 is corrugated and has a raised
outer peripheral
rim for containing any spilt water. When the dispenser unit is removed from
the condensor
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10.
unit, a matching cover may be fitted or clipped onto the condenser unit to
enclose the recess
and protect the condenser unit from the environment.
A further dispenser unit 14 is shown in Fig. 3a. As with the embodiment shown
in Fig.1a,
this unit is a wall mounted unit with a removable storage bottle 28, but
differs in that rear
region of the dispenser unit 14 is received in a cavity defined in the
interior wall 44 on which
the dispenser unit is mounted such that the front region 46 of the unit is
flush against the
wall. As shown more clearly in Fig. 3b, a channel 48 is defined in each side
of the storage
tank which receive corresponding guides 49 provided in the recess 50 of the
dispenser unit
for retaining the storage tank in position within the unit. Further support of
the storage
bottle 28 is provided by the shelf 52 of the dispenser unit 14 on which the
bottle rests.
In this embodiment, the dispenser unit 14 is mounted above a basin 54. A user
may,
therefore, wash their hands in the basin 54 using mains water from the tap 56
but drink the
potable water from the dispenser unit.
A schematic diagram illustrating the components of the condenser unit 10 is
shown in Fig. 4.
More particularly, and as indicated in the figure, the housing 18 of the
condenser unit 10
incorporates a compartment 58 housing an evaporator 60 and a condenser 62 of
the
refrigeration system. Ambient air A is drawn through an air filter 63 and then
flows to the
evaporator 60 after entering the vent openings 20 of the housing 18. As the
air passes
between spaced apart fins of the evaporator defining condensation surfaces, it
contacts the
condensation surfaces causing the air to be cooled to, or below, the dew point
of water
vapour in the air and thereby, water to condense from the air onto the
condensation surfaces.
The condensed water falls by gravity to the collector 64 in the form of a
funnel, then passes
through heat exchanger 66 and negative pressure trap 68 to a holding tank 70
(see Fig. 6) via
conduit 72.
The cooled air leaving the evaporator 60 passes to the condenser 62, drawing
off heat from
the condenser. This in turn facilitates cooling of hot refrigerant vapour
contained within the
condenser which then condenses to a hot liquid refrigerant. The warmed dry air
which
leaves the condenser 62 is then extracted from the compartment 58 and
exhausted to the
atmosphere by a fan 74. As will be understood, the fan provides a negative
pressure in
compartment 58 which draws the ambient air A into the compartment through
evaporator
for further condensation of water from the air.
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The refrigeration system 16 comprises an electrically powered compressor, and
the
compressor and additional components of the system are contained in a further
compartment 75 within the housing 18 of the condenser unit. The refrigeration
system may
be either a single pressure or dual pressure system, and provides sub-cooled
liquid
refrigerant to the evaporator for evaporation within the evaporator to effect
the cooling of
the evaporator for condensation of the water from the ambient air. The
resulting heated
refrigerant vapour is drawn from the evaporator and passed to the condenser 62
for
condensation to hot liquid refrigerant as described above. To enhance thermal
efficiency,
heat is drawn from the hot liquid refrigerant by the cool condensed water
passing through
heat exchanger 66. This cools the liquid refrigerant prior to the liquid
refrigerant being
recycled to the evaporator as described in more detail below with reference to
Fig. 5.
As shown in Fig. 5, the heated refrigerant vapour is drawn through suction
loop 76 from the
lower region of the evaporator 60 to the electrically powered compressor 78.
The suction
loop 76 traps and holds any liquid refrigerant which might pass from the
evaporator, thereby
preventing the liquid refrigerant from entering and potentially damaging the
compressor ~8.
The refrigerant vapour is compressed and thereby heated in the compressor,
prior to being
discharged through hot gas loop 80 to the top of the condenser 62. The hot gas
loop 80 traps
any liquid refrigerant draining back from the condenser 62 to the compressor
78.
The air drawn to the condenser 62 by the fan 74 cools the high pressure hot
refrigerant
vapour in the condenser such that the refrigerant vapour condenses. The
condensed liquid
refrigerant is then cooled by the condensed water passing through the heat
exchanger 66 as
described above. The cooled liquid refrigerant subsequently drains from the
bottom of the
condenser 62 into reservoir 82, prior to passing from the reservoir through a
filter 84 which
removes any contaminants and moisture from the liquid refrigerant. From the
filter 84, the
refrigerant travels along tubing 86 incorporating a sight glass 88 which
allows a visual check
for the presence of any moisture or bubbles in the liquid refrigerant.
The tubing 86 then feeds the dry, cooled liquid refrigerant to a thermostatic
expansion valve
90. As the liquid refrigerant passes through the valve, the pressure of the
liquid refrigerant
decreases. The resulting low pressure cold liquid refrigerant with some flash
gas is fed from
the expansion valve 90 into the evaporator 60 where the liquid refrigerant
evaporates back
into refrigerant vapour, drawing in heat from the condensation surfaces of the
evaporator
effecting cooling of the ambient air and condensation of the water therefrom
onto the
condensation surfaces.
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For efficient operation of the condenser unit, the flowrate of the ambient air
A through the
compartment 58 is adjusted to optimise condensation of water per unit volume
of the
ambient air flowing through the evaporator 60, while maintaining sufficient
airflow to the
condenser for heat transfer from the condenser to the air for achieving the
condensing of the
refrigerant vapour in the condenser. As will be understood, the refrigeration
system 16
operates to cool the condensation surfaces of the evaporator without freezing
the condensed
water.
For any given prevailing atmospheric conditions, there is a specific humidity
value
measured in grams of water vapour per kilogram of the air. For example, a
specific
humidity of between 4.5 and 6 grams of moisture per kilogram of air correlates
to a dry bulb
temperature of between 1° C and 6.5° C. In use, the condenser
unit 10 is operated to
condense water from the ambient air entering the condenser unit such that the
specific
humidity of the air flowing from the evaporator to the condenser is reduced to
a specific
humidity correlating with a selected reference dry bulb temperature. The
selected dry bulb
temperature will typically be in the above temperature range and usually, will
be in a range
of from about 3.5°C to about 5.5°C and preferably, will be about
5°C or below.
A temperature sensor 92 is provided in the condenser unit 14 for measuring the
dry bulb
temperature of the air passing from the evaporator 60 to the condenser 62 (see
Fig. 4). This
temperature is compared in control module 94 with the selected reference dry
bulb
temperature which has been manually set in the control module. If the dry bulb
temperature
measured by temperature sensor 92 increases above the set reference dry bulb
temperature,
the control module operates actuator 96 such that air intake 98 in the farm of
a hinged
damper opens allowing ambient air A to be drawn into compartment 58 of the
housing 18.
This decreases the flowrate of the ambient air A being drawn into the
evaporator which in
turn lowers the dry bulb temperature of the air leaving the evaporator.
As the flowrate of the air leaving the evaporator is decreased, the amount of
cooled air from
the evaporator available for cooling the condenser also decreases. This
results in a rise in the
pressure of the refrigerant vapour in the condenser above the optimum pressure
for the fixed
refrigeration capacity of the refrigeration system 16. The pressure of the
refrigerant vapour
in the condenser is measured by a pressure sensor 100. In response to the
increased pressure
measured by the pressure sensor, the control module 94 increases the speed of
the fan 74 via
controller 102 and operates actuator 96 to further open the air intake 98 to
increase the
flowrate of air flowing to the condenser, while simultaneously substantially
maintaining the
flowrate of the ambient air A through the evaporator. The increased flowrate
of air to the
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condensor removes heat from the condensor such that the pressure of the
refrigerant vapour
in the condensor reduces to the optimum pressure for the fixed refrigeration
capacity of the
refrigeration system.
The control module 94 continues to monitor the dry bulb temperature of the air
leaving the
evaporator and the pressure of the refrigerant vapour in the condensor
respectively
measured by temperature sensor 92 and pressure sensor 100. If the dry bulb
temperature
sensed by the temperature sensor decreases below the set reference dry bulb
temperature,
the control module 94 operates to decrease the speed of the fan and activate
the actuator 96
to partially or completely close the air intake 98 such that the flowrate of
the ambient air into
the dispenser unit 14 decreases.
The monitoring is repeated at regular intervals to ensure optimum efficiency
of the
apparatus and thereby, maximum condensation of water from the ambient air. The
provision of such timing circuits is well within the scope of the skilled
addressee. For
different latitudes or atmospheric conditions, the reference dry bulb
temperature set in the
control module 94 may be adjusted. The operation of an embodiment of the
invention is
exemplified in Fig. 7 to Fig. 9.
Returning now to Fig. 6, the condensor unit 10 further incorporates a water
circulation
system 104. This system includes a holding .tank 70 which receives the
condensed water
from the collector 64 (see Fig. 4). A pump 106 draws water from the holding
tank 70 and
pumps the water through conduit 108 to T-connector 110. Some of the water
continues along
conduit 108 to ultraviolet light treatment device 112 where the water is
irradiated with UV
light at a wavelength of 253.7 nm prior to being returned to holding tank 70.
As will be
understood, treatment with the UV light kills bacteria and other pathogens
which may be
present in the water.
The remainder of the water entering the T-connector 110 is diverted to
junction 114
comprising a further T-connector, where the water is directed to float valve
116 or activated
charcoal filter 118, or both. If there is sufficient water in holding tank 70
to allow water to
pass from the condensor unit 10 to the remotely located dispenser unit 14, the
float valve 116
closes the end 122 of pipe 124. The float valve 116 comprises a float 126
carried on the end of
float arm 128. The float arm is pivotally hinged at an opposite end to the
interior of the
holding tank 70. As the water level rises in the holding tank, the float 126
rises causing
sealing washer 130 carried by valve body 132 to be pressed against the end 122
of the tubing
124 as the float arm 128 is lifted by the float, preventing water from flowing
back into the
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14.
holding tank 70. When system valve 134 is open, the water pressure generated
by the action
of the pump 106 forces water through filter 118 and auxiliary W light
treatment device 136,
prior to passing to the dispenser unit 14 through feed conduit 22 (see Fig.
1a).
The feed conduit 22 comprises a flexible hose connected to the condenser unit
10 and the
dispenser unit 14 by fittings (eg. bayonet) which sealingly couple with
corresponding female
fittings on the condenser unit and dispenser unit. As indicated above, a
return conduit in
the form of a flexible hose (not shown) for recirculating excess water from
the dispenser unit
to the holding tank 70 via a return pipe in the condenser unit is also
provided. Accordingly,
water continually flows back and forth between the condenser unit 10 and the
dispenser unit
14. The water is, therefore, treated with UV light each time it is
recirculated through the
condenser unit before being returned to the dispenser unit. As with the feed
conduit, the
return conduit is coupled to the condenser unit and dispenser unit by mating
connectors.
As water is pumped from the holding tank 70 in the condenser unit to fill the
storage bottle
28 of the remotely located dispenser unit 14, or to otherwise meet demand for
the water, the
water level in the holding tank lowers and the float valve starts to open
allowing a portion of
the water pumped to junction 114 to discharge through the partially opened end
122 of pipe
124. As a result, the water pressure of the water passing through system valve
134 decreases
and the flowrate of the water to the dispenser unit decreases accordingly. The
flowrate
continues to decrease until eventually the float valve is fully opened and
insufficient water
pressure is available to pump water through the system valve. However,
sufficient water
remains in the storage tank 70 to allow re-circulation of the water through
the UV light
treatment device 112, but water cannot be pumped to the remote dispenser unit
14 until
more condensed water enters the storage tank from the collector 64.
The UV light treatment device 112 is illustrated in Fig. 10 and comprises an
ultraviolet lamp
138 mounted in a holder 140 incorporating a reflector 142. Lamp sockets 144
receive the UV
lamp and are arranged within the holder 140, one at each end of the UV lamp
respectively,
and facilitate electrical connection to the lamp. A quartz tube 146 defining a
treatment
chamber for passage of the water is received by top and bottom elbows 148 and
150 which
hold it in position in front of the UV lamp 138. One elbow is mounted on each
end plate of
the holder, respectively. A resilient washer (not shown) between each end of
the quartz tube
and the corresponding elbow prevents water leakage.
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15.
The bottom elbow 150 incorporates an inducer element for inducing spiral water
flow in the
treatment chamber. The inducer element 152 comprises a plate member 154
twisted into a
spiral and which is held in a fixed position on the end of a stem 156
projecting from a base
158 of the inducer element. In use, the water enters inlet 160 defined in the
body 161 of the
bottom elbow which directs the water into contact with the twisted plate
member 154 of the
inducer element in the treatment chamber. The width of the plate member
substantially
corresponds to the diameter of the treatment chamber. As the water flows over
the plate
member, spiral water flow is induced along the treatment chamber. This mixes
the water
and maximises exposure of the water to the UV light, and thereby treatment of
the water.
The reflector 142 enhances treatment of the water by reflecting lateral UV
light back onto the
treatment chamber. As also shown in Fig. 10, one or more further reflectors
may be
provided for reflecting incident UV light back onto the treatment chamber.
A partially exploded view of the bottom elbow 150 is shown in Fig.11. As
indicated in the
figure, a groove 164 receiving an O-ring 166 is defined in the base 158 of the
inducer element
152 for preventing water leakage between the base 158 and the body 161 of the
bottom
elbow. A male thread 168 defined on the base 158 engages with a corresponding
female
thread defined in the interior of the body 161. Rather than a stationary plate
member 154
twisted into the form of a spiral, the inducer element may incorporate a rotor
of the type
illustrated in Fig. 12 rotatably mounted on the end of the stem 156 of the
inducer element
and which is rotated as the water passes from the bottom elbow into the kill
chamber for
achieving the spiral flow of the water.
An end view of the holder 140 of the UV light treatment unit 112 is shown in
Fig. 13. As can
be seen, a hole 1?0 is defined in each end plate of the holder for reception
of the
corresponding elbow 148 or 150. The reflector is formed from stainless steel
sheet and has
opposing outwardly directed side arms 172. The side arms are inclined relative
to one
another and extend substantially along the entire length of the holder 140.
The rear 174 of
the reflector stands against the interior face of the holder and is held in
position by reception
of the lamp sockets 144 through corresponding openings (not shown) defined in
each end
region of the reflector. The auxiliary LTV treatment device 136 has the same
construction as
that shown in Fig. 10.
As indicated in Fig. 14, the dispenser unit 14 is provided with an array of
indicator lamps for
indicating the operational status of various parameters of the modular system.
In the
particular example illustrated, separate indicator lamps are provided for
indicating whether
the holding tank 70 is full or empty, whether water is available from the
holding tank 70,
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16.
whether the air filter 63 or water filter 118 in the dispenser unit need
cleaning or changing,
and whether there is a fault in the modular system, respectively. Relevant
ones of the
indicator lamps 176 are lit in response to frequency encoded signals received
by an electronic
frequency decoder 178 housed in the dispenser unit from an electronic
frequency encoder
180 housed in the dispenser unit. The signals pass from the frequency encoder
180 to the
frequency decoder 178 via twisted pair electrical wires connecting the
frequency encoder to
the frequency decoder.
Input signals to the frequency decoder 180 are provided from switches arranged
for
indicating the status of the parameters being monitored. For instance, a float
switch for
indicating the holding tank 70 is full may be located within the holding tank
such that when
the water level rises to the holding capacity of the holding tank 70, the
float switch closes
providing a signal to the frequency encoder 180 which in turn transmits a
signal to the
frequency decoder which causes the relevant lamp 176 to light indicating the
storage tank is
full. When the float switch closes, the operation of the compressor is also
stopped which in
turn stops condensation of water and the storage tank from filling further. An
overflow
outlet defined in the holding tank 70 and which leads to a drain is also
provided as a
safeguard. When the level of water in the holding tank falls, the float switch
opens and the
compressor 78 recommences operation.
Similarly, a float switch or other suitable switch may be located in a lower
region of the
holding tank 70 for indicating low water level. A yet further such switch may
be located
slightly higher than the tank for indicating water availability. Switches
which may be used
for these purposes include switches which are short circuited and thereby
closed by contact
with water.
The flow of ambient air through the evaporator 60 in use will generally be
within
predetermined upper and lower limits. To indicate that the air filter needs
cleaning or
replacing, a sail switch is provided between the air filter and the evaporator
60. When the
flow rate of the ambient air decreases below the normal operating range,
movement of the
sail closes a contact generating a signal to the frequency encoder 180 which
in turn causes the
corresponding indicator lamp 176 on the remotely located dispenser unit 14 to
light. Of
course, rather than using switches which are normally open, switches which are
normally
closed and cause a signal to be generated upon being opened may be utilised
instead.
Rather than a flow switch, a timer comprising a timing circuit for timing
hours of operation
of the dispenser unit is used for generating a signal to the frequency encoder
180 for causing
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17.
the indicator lamp 176 on the dispenser unit for indicating the water filter
118 requires
attention. At the end of a predetermined time limit which may be several
months or more in
length, a signal is generated by the timer for causing the corresponding
indicator lamp 176 to
light.
Instead of switches, a water level sensing and switching apparatus may be
utilised for
monitoring the depth of water in the holding tank 70 as shown in Fig. 15. The
sensing
apparatus comprises an upright cylinder 184 arranged in the holding tank to
receive the
condensed water from the collector 64 of the condensor unit 10. Two closely
spaced
reference electrodes 186 are located in the cylinder. The cylinder fills with
water from the
collector 64 until depth h1 is reached which represents the maximum water
depth the
cylinder can hold. As more water drains into the cylinder, water begins to
overflow from the
cylinder through overflow tube 188 into the holding tank 70. The reference
electrodes 186
are connected to an electronic sensing circuit through wires 190 and provide a
reference
conductive resistance.
A pair of conductive electrodes 192 which are identical to reference
electrodes 186 are
mounted in the storage tank 70 at the same vertical position as reference
electrodes 186.
With no water in the storage tank 70, the electrical resistance between
conductive electrodes
192 is infinite. As water enters the tank from overflow tube 188, the water
level represented
by h2 rises and lowers the conductive resistance between the conductive
electrodes. The
conductive electrodes are also connected to the sensing circuit.
When the holding tank 70 is full, the conductive resistance across conductive
electrodes 192
is substantially identical to that across the reference electrodes 186. As the
depth of water
falls in the holding tank 70, the resistance between conductive electrodes 192
changes. The
depth of water in the holding tank is determined by the sensing circuit by
comparing the
conductive resistance across the conductive electrodes 192 with the conductive
resistance
across the reference electrodes 186.
The sensing circuit is illustrated in Fig. 16 and senses the depth of water in
the holding tank
as follows. The combination of resistor R1 and the resistance from reference
electrodes 192 in
series provides a reference voltage +Vref at point X in the circuit. +Vref is
applied to two or
more comparators (CP1, CP2, CP3) through resistance ladder made up of R3, R4,
R5. The
values of each resistor in the ladder are selected to provide reference inputs
to each
comparator equal to a known proportion of +Vref (eg, 1/4, 1 / 2 of +Vref). The
combination of
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18.
variable resistor R2 and the resistance from conductive electrodes in series
provides a
variable voltage +Vvar at point Y in the circuit.
+Vvar is applied to the second input of each comparator. As +Vvar changes with
the change
in water depth in the holding tank 70, the pre-set voltage ladder determines
which
comparator switches on or off. The presence or absence of voltage output from
each
comparator turns indicators in the form of light emitting diodes arranged on
the dispenser
unit on or off, thus indicating the depth of water in the storage tank 70 in
the condenser unit.
The output from a comparator may also control a function of the condenser
unit, such as
turning the condenser 10 and fan 74 off when the storage tank is full. For
calibration
purposes, variable resistor R2 is adjusted with both pairs of electrodes 186
and 192 fully
immersed in water of the same quality to achieve +Vref equal to +Vvar.
Another embodiment of a dispenser unit 14 is illustrated schematically in Fig.
17. In this
embodiment, the dispenser body comprises a recess 194 receiving a storage tank
195 on
platform 196. The platform 196 of the dispenser unit is mounted on a plurality
of support
springs 198. A valve mechanism 200 is positioned at the upper rear of the
recess and is
arranged to open and sealingly close outflow opening 202. The valve mechanism
comprises
an actuator arm 204 and a closure arm 206 which pivot about pivot pin 208. A
spring 210
biases the closure arm against the outflow opening. When the storage tank 195
is received in
the recess 194 of the dispenser unit as shown in the figure, the actuator arm
204 of the spring
mechanism compresses the spring and the closure arm 206 is rotated about the
pivot 208
opening the oixtflow opening. This allows water whieh has entered storage
compartment
211 of the dispenser unit through inlet 212 from the remotely located
condenser unit 10 and
overflowed pipe 214, to flow from outflow opening 202 into the storage tank
through an
opening 216 defined in the storage tank. The mass of the storage tank is
sufficient to
maintain the valve mechanism in the open position.
As the storage tank fills with water, the support springs 198 compress and the
platform 196
lowers within the recess 194 of the dispenser body. When the storage tank is
full, the
actuator arm 204 of the valve mechanism is released allowing the closure arm
to pivot about
the pivot pin 208 and sealingly close the outflow opening 202, preventing the
flow of further
water from the storage compartment 211 of the dispenser body 26 through the
outflow
opening. With closure of the outflow opening, water entering the storage
compartment 211
accumulates raising the level of the water in the storage compartment to the
outlet 216.
Excess water then flows from the outlet and is recirculated to the condenser
unit as
described above.
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19.
It will be appreciated by persons skilled in the art that numerous variations
and/ or
modifications may be made to the invention as shown in the specific
embodiments without
departing from the spirit or scope of the invention as broadly described. The
present
embodiments are, therefore, to be considered in all respects as illustrative
and not restrictive.
For instance, rather than the dispenser unit 14 storing condensed water from
the condensor
unit, all of the water may be recirculated directly back to the condensor unit
if not dispensed
immediately from the dispenser unit on demand from a user.
