U.S. patent application number 12/486019 was filed with the patent office on 2010-12-23 for body armor suite cooling system.
This patent application is currently assigned to The Government of the US, As represented by the Secretary of the Navy. Invention is credited to Graham K. Hubler, Yan Kucherov.
Application Number | 20100319381 12/486019 |
Document ID | / |
Family ID | 43353096 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100319381 |
Kind Code |
A1 |
Hubler; Graham K. ; et
al. |
December 23, 2010 |
Body Armor Suite Cooling System
Abstract
A body cooling system is provided for utilization with a
protective suit worn by a person. The cooling system includes an
external air flow source that produces an air flow and blows it in
free atmosphere towards an evaporative cooling apparatus. A fluid
volume flows from the cooling apparatus to a conduit contained in
an undersuit worn under the protective overcoat. A pump circulates
fluid through the conduit. The undersuit includes both an envelope,
surrounding an outer surface of the conduit, and a cloth layer,
situated closest to the skin, to aid in a transfer of heat from a
body to the fluid flowing in the conduit. The evaporative cooling
apparatus can include a radiator body having finger-like
projections extending therefrom. A fluid channel is formed within
the evaporative cooling apparatus for egress of the heated fluid
carried away from the undersuit.
Inventors: |
Hubler; Graham K.;
(Highland, MD) ; Kucherov; Yan; (Alexandria,
VA) |
Correspondence
Address: |
NAVAL RESEARCH LABORATORY;ASSOCIATE COUNSEL (PATENTS)
CODE 1008.2, 4555 OVERLOOK AVENUE, S.W.
WASHINGTON
DC
20375-5320
US
|
Assignee: |
The Government of the US, As
represented by the Secretary of the Navy
Washington
DC
|
Family ID: |
43353096 |
Appl. No.: |
12/486019 |
Filed: |
June 17, 2009 |
Current U.S.
Class: |
62/259.3 ;
165/121 |
Current CPC
Class: |
F28D 5/00 20130101; F25D
7/00 20130101; A41D 13/0053 20130101; F28D 15/00 20130101; F25D
2400/26 20130101 |
Class at
Publication: |
62/259.3 ;
165/121 |
International
Class: |
F25D 23/00 20060101
F25D023/00; F28F 13/12 20060101 F28F013/12 |
Claims
1. A body cooling system for use with an associated protective suit
to be worn by a person, the cooling system comprising: a cooling
apparatus positioned external to the protective suit; an air flow
source positioned external to the protective suit in fluid
communication with said cooling apparatus; a suit positioned
between an innermost layer of the protective suit and the person's
skin, said suit includes at least one conduit which allows fluid to
flow to and from said cooling apparatus; wherein heat from the
person's body transfers to said fluid flowing in said conduit, said
conduit then delivers said fluid to said cooling apparatus, wherein
said air flow source produces a flow of air directed towards said
cooling apparatus, wherein said air flow source blows air into a
space, external to both said suit and the protective suit, wherein
said fluid in said cooling apparatus evaporates upon contact with
said air current.
2. The body cooling system of claim 1, wherein said suit comprises
a heat transfer element to aid in transfer of heat from the
person's body to said fluid flowing in said conduit, wherein said
heat transfer element is a heat conducting envelope surrounding an
outer surface of said conduit.
3. The body cooling system of claim 2, wherein said heat conducting
envelope comprises a heat conducting metal, selected from a group
comprising copper, silver, aluminum and brass.
4. The body cooling system of claim 2, wherein said conduit
comprises a supply pump for circulating fluid through said
conduit.
5. The body cooling system of claim 1, wherein said suit comprises
a heat conducting cloth layer to aid in transfer of heat from the
person's body to said fluid flowing in said conduit, said heat
conducting cloth layer is positioned adjacent to skin of the person
and spaced apart from the protective suit.
6. The body cooling system of claim 5, wherein said heat conducting
cloth layer comprises a heat conducting metal, selected from a
group comprising copper, silver, aluminum and brass.
7. The body cooling system of claim 5, wherein said heat conducting
cloth layer comprises copper.
8. The body cooling system of claim 5 further including a layer of
biologically inert material interposed between said heat conducting
cloth layer and the person's skin, said layer of biologically inert
material being in direct contact with the person's skin to minimize
any irritative and abrasive contact between said heat conducting
cloth layer and the person's skin.
9. The body cooling system of claim 1, wherein said at least one
conduit comprises portions spaced apart from each other by 5 to 10
centimeters.
10. The body cooling system of claim 1, wherein said cooling
apparatus comprises a radiator body having at least two elongate
projections extending therefrom.
11. The body cooling system of claim 10, wherein said at least two
elongate projections are disposed in parallel to each other in a
plane, said plane is transverse to a direction of an air flow path
forced from said air flow source, wherein said air flow contacts
said at least two elongate projections.
12. The body cooling system of claim 10, wherein said radiator
comprises five elongate projections.
13. The body cooling system of claim 10, wherein said radiator body
comprises: at least one surface fluid channel within the radiator
body, wherein a first end of said fluid channel connects to a first
end of said conduit contained in said suit and a second end of said
fluid channel connects to said opposing end of said conduit.
14. The body cooling system of claim 13, further comprising at
least one nozzle formed in said fluid channel provided for egress
of fluid carried away from said suit.
15. The body cooling system of claim 13 further including a wicking
material coating outer surfaces of said at least two elongate
projections and crevices formed therebetween, wherein air flow
which contacts said wicking material causes said fluid contained
therein to evaporate.
16. The body cooling system of claim 1 further comprising a power
source to push fluid volume through said at least one conduit or to
drive said air flow source for production of said air current.
17. The body cooling system of claim 1 further comprising a
reservoir fluidly communicating with said conduit for supplying
fluid to said conduit.
18. The body cooling system of claim 9 further comprising a foam
pad interposed between said adjacent portions of said at least one
conduit on said suit.
19. The body cooling system of claim 1, wherein said air flow
source is a mechanical fan or a blower.
20. A body cooling system for use with an associated protective
suit worn by a person, the cooling system comprising: a cooling
apparatus disposed external to the protective suit; an air flow
source disposed external to the protective suit in fluid
communication with said cooling apparatus; an undersuit positioned
between the protective suit and the person's skin, said undersuit
comprises at least one conduit for allowing water flow to and from
said cooling apparatus and a pump within the conduit to circulate
water through the system; a heat conducting material surrounding
said at least one conduit; and, a layer of material to aid in
transfer of heat from the person's body to said water flowing in
said at least one conduit, said layer of material is positioned
adjacent the person's skin and spaced apart from the protective
suit; wherein heat from the person's body transfers to said water
flowing in said at least one conduit, said at least one conduit
then delivers said water to said cooling apparatus, wherein said
air flow source produces a flow of air directed towards said
cooling apparatus, said air flow source blows air into a space near
said water resulting in said water in said cooling apparatus
evaporating upon contact with said air current.
Description
BACKGROUND OF THE DISCLOSURE
[0001] The present invention relates generally to a body suit
cooling system. More specifically, it relates to a body suit
cooling system having an evaporative cooling system that utilizes a
free air approach to remove body heat from a person.
[0002] A coolant fluid such as water has an advantage of high
volume heat capacity and much higher thermal conductivity compared
to air. The heat exchange coefficient for liquid such as water is
orders of magnitude higher than for air, resulting in the
possibility for compact and energy efficient cooling systems. It is
difficult to use the human body's evaporative cooling system when a
person is wearing multiple layers of clothing. Thus, the
evaporative process should occur outside of the person's body suit
and water should be supplied from an outside source. Since it takes
only about ten milliwatts of power to provide an air flow in an
open space, a free air evaporative system can have improved
efficiency.
[0003] An example of an existing cooling system is provided by
Med-Eng Systems Inc. of Ottawa, Canada. A sample water flow rate
for the system would be 50 g/s (about 50 Gph). A water storage
bottle would be positioned such that supplying the water volume
against the force of gravity would require approximately 0.5 W
(watts) of power. If the water pump efficiency is 50 percent, it
means that about 1 W of power is lost. Furthermore, existing
cooling systems are formed of a large number of capillary tubes,
which collect heat from a large body area. This results in large
power losses due to the viscose friction in small tubes and very
complex and expensive tube connections. Instead of less than one
watt of electric power to push the water volume through the tubes
with small viscose losses, the system uses much more power.
[0004] The cooling system typically uses ice to cool the vest. In
addition to the logistical problems of this approach, the heat of
fusion of water is 6.013 kJ/mole. Heating water from 0.degree. C.
to 30.degree. C., adds another 2.257 kJ/mole, resulting in a total
heat adsorbing capacity of 8.27 kJ/mole or 459 kJ/l. In comparison,
water heat of evaporation is 40.683 kJ/mole or 2260 kJ/l for
evaporative cooling. Thus, approximately three hours of cooling at
200 watts of heat release by a human body can be supplied by one
liter of water. Temperature differences in an evaporative cooling
system depend on ambient air temperature and humidity. For example,
in a dry climate, a standard rooftop evaporative cooler can result
in 20-25 K temperature differences. For a closed looped evaporative
cooler 6-7.degree. C. temperature can be achieved unless humidity
approaches 100 percent.
[0005] Latent heat of vaporization is an amount of energy released
or absorbed by a chemical substance, such as water, during a phase
transition such as between a liquid phase to a gaseous phase. In
the process of evaporative cooling, the conversion of a substance
from a liquid state to a gaseous state causes a decrease in
temperature of the remaining liquid. For example, air is blown over
water, which causes the liquid water's surface molecules to
evaporate to water vapor. This liquid-to-vapor phase transition
requires an input of energy to overcome molecular forces of
attraction between water molecules; this necessary energy input
results in a temperature drop at the water's surface.
[0006] Perspiration is the human body's natural mechanism to keep
cool; however, the removal of excess heat depends on the perspired
fluid's contact with air. In certain environments, persons wear
attire which traps the perspired fluid in a gap formed between the
garment and the skin. Heat stress becomes a concern for these
persons wearing work suits, especially impermeable suits, in hot
climates. Examples of such persons include military servicemen in
combat, clean-up crews at toxic spill sites, health workers in
quarantined outbreak sites, etc. Existing self-contained
evaporative cooler systems were designed for these applications to
maintain the person's body at healthy and safe temperatures.
[0007] Existing evaporative cooling systems depend on an external
power source to draw air towards and blow air flow over the cooling
media. Air must move into contact with the liquid to affect the
cooling process. A problem with existing self-contained evaporative
cooling systems is a reliance on a thin gap air approach, i.e.,
existing systems utilize schemes which direct air flow into a thin
gap formed between the person's body to be cooled and the suit the
person is wearing. The relatively short clearance (referred to as a
"gap") between the body and the suit requires an especially
powerful, external blower to push air into the gap. As a result,
this method requires a high consumption of energy.
[0008] Accordingly, there is a need for a body suit cooling system
which overcomes the above-mentioned deficiencies and others in
existing systems. The present disclosure utilizes a free air
approach, wherein an external power device, such as a fan, moves
air into a free atmosphere space adjacent the suit while requiring
less energy.
BRIEF DESCRIPTION OF THE DISCLOSURE
[0009] The present disclosure is directed towards a body cooling
system for utilization with a protective suit worn by a person. The
body cooling system includes an evaporative cooling apparatus and a
cooperative air flow source, both of which are situated external to
the protective suit. The air flow source, which is a mechanical fan
or blower, produces a flow of air and blows it in free atmosphere
towards the cooling apparatus. An undersuit, situated between an
innermost layer of the protective suit and the wearer's skin,
includes at least one conduit formed thereon. A volume of fluid
flows from a reservoir in the evaporative cooling apparatus to the
conduit, and is circulated through the conduit by a pump, wherein
heat from the body is transferred into the fluid. The fluid flows
through the conduit to the evaporative cooling apparatus, wherein
the heated fluid evaporates upon contact with the air current.
[0010] The undersuit includes both a heat conducting envelope,
surrounding an outer surface of the conduit, and a heat conducting
cloth layer, situated closest to the skin, to aid in a transfer of
heat from the wearer's body to the fluid flowing in the conduit.
The undersuit preferably includes a copper envelope surrounding the
conduit and a copper cloth layer. A thin layer of biologically
inert material can be situated between the copper cloth layer and
the skin to prevent any irritative and abrasive contact between the
copper cloth layer and the skin.
[0011] The apparatus utilizes an evaporative cooling process.
Specifically, the apparatus includes a radiator body having at
least two elongate, finger-like projections extending upwardly
therefrom. The finger-like projections are oriented substantially
in parallel across the same plane, which is transverse to a
direction of an air flow path forced from the air flow source. A
fluid channel extends along an internal length of the evaporative
cooling apparatus and connects to the conduit. The fluid channel
provides for egress of the heated fluid carried away from the
undersuit. The fluid leaving the channel is directed toward the
finger-like elongate projections by a wicking material. The air
flow contacts the wicking material enveloping both the finger-like
projections and the crevices formed therebetween, which aids in the
evaporation.
[0012] The present disclosure aims to reduce or minimize a risk of
heat stress, i.e., heat stroke, heat exhaustion, cramps, rashes,
and dizziness, etc., in workers exposed to extreme heat and arid
environments. More specifically, the disclosure minimizes or
prevents symptoms of heat stress in workers covered in partial or
full body suits, which have a tendency to generally trap
perspiration in the area between the suit material and the person's
skin.
[0013] Other aspects of the disclosure will become apparent upon a
reading of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective exploded view of a body suit cooling
system according to a preferred embodiment of the present
disclosure;
[0015] FIG. 2 is a cross-sectional elevational view of the suit
portion shown in FIG. 1;
[0016] FIG. 3 is a cross-sectional elevational view of the external
cooler portion shown in FIG. 1; and,
[0017] FIG. 4 shows an assembly of the body suit cooling system
shown in FIG. 1 worn on a person.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0018] The present disclosure is directed to a body suit cooling
system. Specifically, it is directed to a self-contained system
worn by a person to maintain body temperature at healthy
levels.
[0019] For purposes of this disclosure, the terms "body armor" and
"suit" (hereinafter collectively referred to as "suit" or
"protective suit") refer to any protective clothing worn by a
person. The present disclosure is particularly useful when used in
conjunction with military suits and other armor worn by soldiers in
combat; however, its use is not strictly limited to garments worn
by servicemen. The term "suit" can similarly refer to explosive
ordinance disposal (EOD) suits. The term "suit" can further include
environmental suits designed for particular hostile environments.
These suits can include any material which protects the wearer from
certain temperatures, climates, or pressures. The term "suit" can
also refer to a contamination or a hazardous material ("hazmat")
suit, which protects its wearer from hazardous materials or
substances. The term "suit" can further refer to demron suits,
which include radiation-blocking fabric that shield its wearer from
radiation. The term "suit" can further include any protective
clothing made from materials that block chemical and biological
threats to the wearer.
[0020] The term "portion suit" refers herein to any material which
covers any portion of a human body or an entire body. Portion suits
can include tactical vests, boots, pants, or any other tactical
gear that covers only a designated body region. Entire suits
include one-piece outfits that cover all body regions.
[0021] For purposes of this disclosure, the term "suit" or
"undersuit" can refer to a layer of material situated between the
protective suit and the person's skin. The protective suit is
oftentimes gas or vapor tight. As a result, it thwarts a body's
natural cooling process by trapping sweat or perspiration between
the impermeable material layers and the skin. The undersuit acts as
an additional layer of a heat spreading material made either part
of or separate from a protective suit.
[0022] For purposes of this disclosure, the term "cooling system"
refers to a system which utilizes an evaporative cooling process.
Evaporative cooling processes rely on both an evaporative fluid and
moving air. Air must come into direct contact with the fluid so
that some of the fluid's molecules can mix with the air. The air
removes heat from the fluid during evaporation, which results in
cooling of the fluid.
[0023] Referring now to FIG. 1, an exploded view of a body suit
cooling system (hereinafter referred to as "cooling system 10")
according to a preferred embodiment of the present disclosure is
shown. The cooling system 10 includes an undersuit 12 that
cooperates with both an evaporative cooler apparatus 14
(hereinafter synonymously referred to as "evaporative cooler") and
an air flow source 16 to cool a person wearing the under suit
beneath a protective suit.
[0024] The undersuit 12 is at least one layer of material having a
body-conforming characteristic. It is designed to be worn adjacent
to the person's skin. In the present disclosure, the undersuit 12
is a separate garment worn beneath the innermost layer of a
protective suit 26. That is, the person puts on the undersuit
first, then wears the protective suit over it. The undersuit 12 can
also be removably attached to the protective suit at attachment
points so that its position remains fairly constant relative to the
evaporative cooler apparatus. It is alternatively contemplated that
the undersuit 12 is made as part of the protective suit, i.e., the
undersuit would actually form the protective suit's innermost
layer.
[0025] The undersuit 12 shown in FIG. 1 is basically vest-shaped,
which generally covers a wearer's upper body, shoulders, and arms
and is underneath an outer protective suit 26, also shown as
vest-shaped. Alternately, the undersuit 12 of the disclosure can be
a full-body undersuit, or it can be specifically designed to cover
only certain portions of the body. The undersuit 12 can include a
plurality of separate members that are combined to cover a portion
of or an entire body. For example, the undersuit may include an
upper body portion and a lower body portion which can be
interchangeably worn together or as separate garments. The
undersuit 12 shown in FIG. 1 is shown as a vest-shape for purposes
of illustration; however, other undersuits are also contemplated by
the disclosure. The undersuit 12 primarily functions as a
heat-spreading element.
[0026] Referring now to FIG. 2, a cross-section of the undersuit 12
is shown, which includes a conduit system 18 that forms a pattern
across an outer surface of a copper cloth layer 20. The conduit
system 18 is preferably formed by a single conduit that results in
a specific forced flow (closed) loop to-and-from the evaporative
cooler apparatus 14. Referring to FIG. 1, a conventional, compact
water pump 17 is provided as part of the conduit system and can be
placed before the cooling apparatus 14. However, other locations
for the water pump are contemplated by the disclosure. The pump is
used to circulate the water through the conduit. In the preferred
embodiment, the single conduit can extend in a back and forth
pattern, across front or rear surfaces of the undersuit 12, or it
can extend in a spiral pattern, continuously wrapping around the
cloth fabric. In the specific embodiment, the conduit extends
to-and-from the evaporative cooler apparatus 14 while the remaining
portion of the conduit extends about the undersuit 12. Conduit
characteristics and patterns can vary for undersuits 12 worn in
different environments and for different applications.
[0027] The conduit or tubes (hereinafter collectively referred to
as "conduit 18") of the conduit system are preferably manufactured
from a thermoplastic material. The heat exchange coefficient, used
to measure heat transfer, is dependent on flux, i.e., the amount of
fluid that flows through a unit area per a unit of time. Because
plastic has a low thermal activity which does not allow for
spreading of heat current, an outer surface of the conduit 18 is
surrounded by a heat-conducting cloth envelope 22.
[0028] The conduit 18 is in direct thermal contact with a heat
conducting cloth layer 20. Heat transfers through various metals at
different rates, but it transfers most rapidly through copper;
hence, in the preferred embodiment, both the cloth layer 20 and an
envelope 22 are formed of copper. Other embodiments are
contemplated, however, which utilize different metals. Either one
or both the cloth layer 20 or the envelope 22 can be formed of
aluminum, silver, brass, or any other material with a high thermal
conductivity, so long as the metal selected both effectively
transfers heat and prevents or minimizes risks to the wearer.
[0029] Spacing between surface portions of conduit 18 is also
dependent on the metal selected for the cloth layer and the
envelope. Because copper transfers heat most expeditiously, a cloth
layer 20 made of copper and envelope 22 made of copper provide for
an increase in the spacing between outer surfaces of conduit 18.
Spacing, as used herein, refers to the distance between opposing
outer surfaces of neighboring or adjacent lengths of conduit
portions. It is envisioned that portions of the conduit 18 of the
cooling system 10 are spaced about 5-10 centimeters from each
other.
[0030] A further advantage provided by copper cloth layer 20 and
copper envelope or mesh 22 is a decrease in the viscous surface
friction area of the conduit. That is, the heat conducting cloth
layer and envelope allow for the tubes of conduit 18 to have an
enlarged diameter. It is envisioned that a cross-sectional area of
the tubes of conduit 18 is at least twice as great as that of
corresponding conduits in existing cooling systems. The diameter of
the conduit 18 of the present disclosure is between 6-8 millimeters
as compared to 2-3 millimeters in existing systems. The advantage
of an enlarged diameter of the tubes of the conduit is that it has
the effect of reducing flow resistance of the conduit, and fewer
tubes are required than if the tubes had a smaller diameter.
[0031] Because heat transfers from the person's body to the fluid
flowing within the conduit 18, the copper cloth layer 20 is
situated closest to a person's skin 24 and farthest from the
protective suit 26. The copper cloth layer 20 includes an inner
surface 21, adjacent the conduit 18 and the envelope 22, and an
opposite, outer surface 23, adjacent the skin 24. The outer surface
23 is coated with a thin layer of biologically inert material 28.
Layer 28 is in direct contact with the person's skin 24, and its
function is to prevent or minimize any irritative or abrasive
contact between the copper cloth layer 20 and the skin. The
disclosure contemplates that the thin layer of biologically inert
material 28 is selected from a group including, but not limited to,
for example, Capron, Nylon, and cotton, etc. FIG. 2 further shows
cushion or foam layers or members 30, formed of foamed or similar
material pads, which fill spaces or gaps 31 formed between adjacent
conduit 18 portions, the copper cloth layer 20, and the suit 26.
Alternatively, the space 31 can also be left empty.
[0032] Body heat transfers to the fluid flowing within the conduit
18. A terminal end of the conduit 18 is separate from the copper
cloth layer 20 for delivery of outgoing fluid to the evaporative
cooling apparatus 14.
[0033] Referring now to FIG. 3, the evaporative cooling apparatus
14 is shown, which is positioned external to the protective suit
because it relies on a free atmosphere or air flow approach to
cooling. The evaporative cooling apparatus 14 includes a radiator
body 32 having a plurality of elongate projections (hereinafter
referred to as "fingers 34") extending outwardly therefrom. The
fingers 34 are disposed substantially in parallel to each other and
are equally spaced apart, but other configurations are also
contemplated by the disclosure. In the preferred embodiment, the
fingers extend across a same plane, which is transverse to the
direction of forced air flow (which is shown as into and out of the
page of FIG. 3). The fingers 34 are shown to be formed of equal
lengths in FIG. 3, which approximately doubles an overall height of
the body 32, but lengths of individual fingers 34 are not limited
to any one dimension in relation to other fingers. FIG. 3 more
specifically shows a cross-sectional area of a radiator body 32
having five fingers 34 projecting upwardly from the body's top
surface 33. However, other numbers of fingers are also contemplated
by the disclosure. The radiator body 32 may be formed by an
elongated member which accommodates fingers 34 all extending in the
same plane. In alternative embodiments, the radiator body 32 may be
annular, polygonal, cylindrical, or any other configuration which
does not depart from the scope of the disclosure.
[0034] The preferred embodiment of the present disclosure includes
a metal-formed radiator body 32, preferably formed of aluminum,
including a plurality of surface fluid channels 36 extending along
its internal length transverse to the fingers 34. A first end 37 of
the fluid channel 36 connects to a first terminal or distal end 39
of the conduit 18 contained in the undersuit 12, while a second
opposite end 41 of the channel connects to an opposing terminal or
distal end 43 of the conduit. At least one nozzle 38 formed in the
fluid channel 36 provides for egress of fluids carried away from
the undersuit 12. Placement of the nozzle 38 is preferably on the
fluid channel's surface 45 closest to the fingers 34. In other
words, the nozzle 38 is preferably oriented such that all fluid
moving through the nozzle is directed toward the fingers 34 and
away from the undersuit.
[0035] An outer surface 47 of each finger 34 and crevices or
recesses 40 formed between adjacent fingers are coated with a
wicking material 42. The wicking material 42 can be selected from a
group including but not limited to melamine, a thin porous cloth
such as cotton or another porous coating, chalk, porous ceramics,
etc. A polyurea coating is one such wicking material 42 utilized in
the preferred embodiment. The wick material 42 is fluid wetted,
i.e., it absorbs fluid and moisture delivered thereto from the
channel 36. The fluid is transformed to a gaseous state, i.e., it
evaporates, when the air flow contacts the fluid.
[0036] An advantage of the evaporative cooler 14 is that it greatly
reduces electric power requirements to drive the air flow source 16
due to the use of the fingers 34. Efficacy of cooling is determined
by both the area of the wet surface and the aridity of air
contacting it. The fingers 34 increase the surface area of wick
material 42 exposed to the moving air current. The fingers 34 also
avoid saturation of the air with vapor from the wick. An air parcel
can only contain a certain amount of moisture before it can no
longer accommodate gaseous molecules. The fingers 34 create spaces
between the fingers, which each act as small air parcels capable of
containing a greater amount of gaseous molecules evaporated from
the fluid contained in the wicking material 42.
[0037] The present cooling system 10 further includes a means 16 to
force air current. Referring to FIGS. 1 and 4, the source provided
is an external, mechanical fan or blower 16. As previously
discussed, existing systems utilize energy consumptive fans which
concentrate air flow into the tight gap formed between the body and
the suit. The present cooling system 10 alternatively blows a large
amount of air into an open, free space. This free space, generally
referred to as the free atmosphere, is external to both the
undersuit 12 and the protective suit. More specifically, the fan 16
produces a flow of air directed towards the radial fingers 34 of
the evaporative cooler 14. The air flow strikes the wicking
material 42 on the surface of the fingers 34, or it continues to
travel therebetween where it contacts the wicking material formed
on the crevices 40. The air current, which comes into immediate
contact with the wicking material enveloping the fingers 34, causes
the fluid contained therein to evaporate.
[0038] The blower 16 does not require a direct communicative
relationship with the undersuit 12 and the evaporative cooler 14;
rather, it can be a separately contained apparatus operated by the
same or independent controls. Existing evaporative cooling systems,
which utilize the free gap approach, consume great amounts of power
to force air currents through the gaps. The free air flow approach
of the present disclosure reduces electric power requirements as
much as 5-to-10 times that compared to existing systems. It takes
only about ten milliwatts of power to provide sufficient air flow
to open space, so the free air flow approach makes the present
system much more energy efficient than existing cooling
systems.
[0039] It is contemplated that any self-contained solar or battery
power source can also be utilized to push fluid volume through the
conduit 18 and to drive the fan for production of air current. In
the present disclosure, this fluid is preferably water, which
transforms to water vapor upon contact with air; however, the
evaporative cooling system 10 is not limited to only water; rather,
any fluid which absorbs heat readily and releases it in atmospheric
air can be similarly used in the system.
[0040] Referring to FIGS. 1 and 2, an additional component for
operation of the cooling system 10 is an external water supply 48.
The external water supply is used to deliver water to the
evaporative cooler system 10 to replenish water lost by
evaporation. For example, a person wearing the present cooling
system may additionally carry on his or her person, or make
available in proximity to the cooling system, a sealed water supply
reservoir or bottle 48 or a standard water pack, which can be used
to replenish fluid into the closed system conduit 18. A water
supply bottle can hold up to one liter of water and possibly
operate the cooling system 10 for an entire day. The supply bottle
can be attached to a belt or backpack worn by a person.
Alternately, an aperture 44 or a channel in communication with the
conduit 18, provides access to the conduit so that the fluid lost
in evaporation can be replenished therein by filling fluid into
aperture 44. The aperture 44 can be located in the radiator body
32. Alternatively, the aperture 44 can be located proximate to the
undersuit so that it can feed water into the conduit 18 just
immediate to the fluid's entrance into the undersuit 12. The supply
bottle 48 would be connected to the aperture via a separate tube
49.
[0041] Essentially, the fluid or water circulates in a circuit,
i.e., in the closed loop formed by the conduit 18, the supply
bottle 48 and pump 17. During each circulation, some fluid in the
conduit 18 loop leaks out to the wicking material 42. In certain
embodiments, a valve (not shown) in association with corresponding
nozzles 38 can control release of the fluid from the conduit 18 to
the fingers 34. More specifically, a one-way valve can regulate
egress of fluid from the conduit, but it can prevent any return of
that fluid (elevated in temperature) not immediately evaporated
into the conduit.
[0042] Referring again to FIG. 4, the evaporative cooling system 10
is shown worn on a person. The undersuit 12 is not visible in the
figure because it is situated beneath the protective suit 26
protecting the wearer from outer elements. The evaporative cooling
apparatus 14 can be supported on a backpack or on a mounting
bracket 50 carried on the person. FIG. 4 shows a rear view of a
person, wherein both the evaporative cooling apparatus 14 and the
blower 16 are supported on a backpack mount. In alternative
embodiments, both the evaporative cooling apparatus 14 and the
blower 16 can be positioned waist-level on a belt loop, or
proximate to a mount protruding from the undersuit.
[0043] The exemplary embodiment has been described with reference
to the preferred embodiments. Obviously, modifications and
alterations will occur to others upon reading and understanding the
preceding detailed description. It is intended that the exemplary
embodiment be construed as including all such modifications and
alterations insofar as they come within the scope of the appended
claims or the equivalents thereof.
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