Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PORTABLE SELF-CONTAINED COOLER/FREEZER FOR USE ON
AIRPLANES, COI~iON CARRIER UNREFRIGERATED TRUCKS
BACKGROUND OF THE INVENTION
Field of the Invention
5 The present invention relates to refrigerated
containers having self-contained refrigeration
systems. Even more particularly, the present
invention relates to an improved portable self-
contained cooler/freezer apparatus wherein either an
1o external bulk supply or self-contained carbon
dioxide canister dispense C02 or like liquid coolant
through a manifold and plate like diffuse system to
regulate temperature within the container, and
wherein a temperature controlled solenoid valve
15 dispenses COZ or like coolant as needed into the
container interior. The plate like diffuser allows
use of the shipping container walls to cool.
General Background
Many truck lines use refrigerated trucks to
2o carry food products over long distances. Typically,
such a truck is designed to carry either frozen
foods or foods that must be maintained in higher,
but still refrigerated temperatures,
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such as, for example, 40°F. These trucks typically carry
either refrigerated or frozen food only and differ from the
typical common carrier truck which is unrefrigerated and
which carries any of a number of bulk, unrefrigerated
commodities, such as palletized loads of any general
merchandise, product, or equipment. Presently, there does
not exist a means for carrying refrigerated and/or frozen
food products over long distances of several hundred or
even thousands of miles via common carrier, namely, with
trucks that are not refrigerated but which have space for
holding any number of general commodities.
Several devices have been patented which have
attempted to provide portable refrigeration devices. An
example is U.S. Patent No. 3,633,381, entitled "Open-Cycle
Portable Refrigerator." In that patent there is disclosed
a portable refrigerator employing an open cycle system. A
stored compressed gas, such as carbon dioxide is passed
from the storage container through an evaporator which
comprises a serpentine passageway for the gas in a
surrounding medium, such as water, an aqueous solution,
which is maintained frozen due to the passage of the
expanding compressed gas through the coiled passageway.
The temperature of the evaporated medium is lower than the
ambient temperature of the interior or the container
comprising the storage portion of the refrigerator which is
cooled thereby. The gas passing through the evaporator may
be exhausted into the interior of the container whereby the
cooler air which is next to the evaporator medium is
circulated throughout the interior of the container.
A portable ice chest having a refrigeration unit is
disclosed in U.S. Patent No. 3,959,982. A substantially
closed refrigeration receptacle in fluid communication with
the outlet side of the primary evaporator receives the
refrigerant which may not have completely evaporated, and
separates the phases by venting the evaporated gas phase to
the atmosphere while directing the unevaporated liquid
refrigerant into a second evaporated coil wherein it is
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completely evaporated. The thermostatically controlled
valve regulates the flow of refrigerant to the primary
evaporator as a function of temperature within the chest.
Several systems have been patented which use liquid
carbon dioxide as part of a refrigeration system. Notice
. for example, U.S. Patent No. 4,399,658, entitled
"Refrigeration System With Carbon Dioxide Injector," issued
to Nielsen; U.S. Patent No. 4,459,825, entitled "Apparatus
For Controlled Reduction In Temperature and Preservation Of
Embryos In A Cryogenic State," issued to Crouch; and U.S.
Patent No. 4,580,411, entitled "Liquid Nitrogen Freezer,"
issued to James Orfitelli.
Several patents have been issued which relate to
shipping containers that have, in some cases,
self-contained refrigeration systems. Examples of these
shipping containers include U.S. Patent No. 3,961,925,
issued to Rhoad; U.S. Patent No. 4,502,293, issued to
Franklin; U.S. Patent No. 4,576,017, issued to Combs et
al.; and U.S. Patent No. 4,606,195, issued to Winkler.
The Rhoad U.S. Patent No. 3,961,925 provides a
portable self-contained refrigerated storage and
transportation container for preserving perishable
commodities and includes an insulated storage chamber for
perishable commodities. A recirculating liquid cooling
system is provided within the container and includes
conduit and nozzle means disposed within the storage
chamber adapted to spray a liquid coolant, such as chilled
brine directly onto the perishable commodities to maintain
them in a uniform cooled temperature. The sprayed liquid
coolant is collected in the bottom portion of the storage
chamber. A closed refrigeration system is also provided
within the container and includes in part heat exchange
means disposed within the bottom portion of the storage
chamber for cooling the sprayed liquid coolant which has
collected there.
The Franklin U.S. Patent 4,502,29.3, entitled
"Container C02 Cooling System," provides a generally
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rectangular container that includes an insulated top,
bottom, opposite sides and opposite end walls. An
upstanding transverse insulated hollow housing is mounted
within the container adjacent one end thereof and a C02 snow
cabinet constructed of good heat transfer material is
disposed within the housing with opposing wall portions of
the cabinet and housing passing exteriorly about the
cabinet. A heat insulative horizontal baffle is mounted
within the container spaced below the top wall and extends
between the sidewalls thereof. The baffle defines a cooled
air passage beneath the top wall extending lengthwise of
the container. The airflow passage includes an outlet end
adjacent and in at least reasonably closed communication
with the end of the cooled air passage adjacent the
aforementioned one container end wall and an inlet end
opening outwardly of the housing into the interior of the
container below the baffle. The end of the cooled air
passage adjacent the other container end wall opens into
the interior of the container and thermostatically
controllable air pump structure is provided to effect
airflow inwardly of the inlet of the airflow passage,
through the airflow passage and into the cooled air
passage. Further, structure is provided for spray
discharging of liquid C02 into the interior of the upper
portion of the cabinet and into the airflow passage at
points spaced therealong in order to form C02 snow therein.
The Combs U.S. Patent No. 4,576,017, discloses a
container for maintaining its contents at a desired
temperature for an extended period of time, such as for use
in shipping contents in a frozen condition. The container
includes an outer shell which is substantially air tight
and which has an inner surface, a pass of heat exchange
medium, a support structure for the heat exchange medium,
and means for maintaining an air space between the contents
of the container and substantially the entire inner surface
of the outer shell of the container and between the
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contents of the container and the support structure for the
heat exchange medium for allowing convection current to
develop in the inner space which circulates past the heat
exchange medium and maintains a substantially uniform
temperature around the contents of the container.
In the Winkler U.S. Patent No. 4,606,195, entitled
"Hypobaric Container," there is provided a storage device
having a walled inner and outer container and a compressed
gas supply contained within the device. A conduit is
provided from the gas supply to the inner container and a
control valve for the conduit responsive to pressures above
and below a super atmospheric pressure value are provided
for closing and opening the valve.
BDMMARY OF THE PRESENT INVENTION
The present invention solves the problems and
shortcomings of the prior art in a simple straightforward
manner by providing an improved portable transportable
refrigeration system for use on common carrier type truck
lines, for example. The apparatus comprises a
self-supporting container having an interior for carrying
refrigerated or frozen cargo and adapted to be lifted by a
forklift, for example. A canister for containing a liquid
refrigerant under pressure is positioned in the upper end
portion of the container interior. A pivotally movable
perforated baffle plate extends transversely across the
container interior at the upper end portion thereof and is
positioned directly under the canister. The baffle plate
can optionally contain the canisters and manifold with a
"floor" to hold frost, ice, and coolness against the
canisters and manifold when the device is preliminarily
charged with coolant from an external "bulk" source. A
temperature control communicates with the canister for
controlling temperature within the interior and includes a
manifold header for discharging liquid refrigerant from the
canister. The manifold header includes a preferably
externally extending inlet opening receptive of a source of
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bulk C02 for quick charging the unit interior with COZ so
that the canisters need only maintain coolness. Further,
the manifold can be used to charge the canisters when empty
with liquid C02 from any bulk external supply source of
liquid C02 or like refrigerant. A pressure control valve
controls the pressure of fluid discharged from the
canister, and a temperature valve is positioned in the
header downstream of the pressure control valve which thus
controls temperature within the interior and over a wide
temperature span of, for example, -20°F to 70°F.
Henceforth very accurate temperatures can be maintained.
Canisters have bent tubes that can be positioned to vent
either gas or liquid. For liquid, the tubes point down and
for gas the tubes point up.
In the preferred embodiment, the container includes a
base plate having two spaced apart parallel slots adapted
to be engaged by a forklift lifting device. The apparatus
in the preferred embodiment includes an array of
perforations extending over a substantial portion of the
hinged baffle plate.
In the preferred embodiment, the canister, the
pressure control valve, and the temperature control valve,
as well as the header, are positioned above the baffle
plate.
In the preferred embodiment, the manifold header is in
the elongated tube having an external inlet that allows the
manifold to be connected to an external C02 "bulk" supply
for either charging the canisters when empty, or for quick
cooling the container interior before a shipment.
In the preferred embodiment, the container includes a
vertical access doorway that extends substantially the full
height of the container, terminating below the hinged
baffle plate in its hinged position.
In the preferred embodiment, the apparatus includes a
valve which communicates with internal vent tubes that can
optionally remove either gas or liquid from the canister.
In the preferred embodiment, the valve includes bent
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tubes or ducts extending internally and to the side inner
wall of the canister from the valve structure, and
positioned to dispense either liquid or gas respectively
when the canisters are in their usual horizontal position.
In the preferred embodiment, there are a pair of
canisters and the manifold header is positioned above the
baffle plate and generally between the canisters.
Use of the hinged transverse plate with perforations
allows the canister, the pressure control valve, the
temperature control valve and the header to be "quick
frozen" by an external source of liquid refrigerant via the
manifold header before the entire apparatus is shipped.
The perforations thus define with the sides of the overall
container a smaller interior space that closely surrounds
the canister, and the header, so that when liquid
refrigerant from an external source is added to the smaller
interior area above the baffle, the smaller interior area
of the baffle, the smaller interior space is filled with
solid C02 and snow and at very low temperatures without
affecting the components of the refrigeration system used
to ship at temperatures above 0°F. "Blasting" the
container with the hinged perforated baffle plate down is
used when quick chilling is desired to commence loading the
container for product which requires accurate temperatures
in the range of -10°F to 70°F. This feature and process
very much extends the period of time during which materials
' can be kept refrigerated.
"Quick chilling" prior to use and prior to shipping
prevents the canisters from losing supply by bringing a
"hot" box to a lower desired temperature, so that the
canisters may not, for example, begin the operation of
dispensing cooling Co2 for several hours after the goods are
shipped.
One embodiment of the apparatus of the present
invention includes a means for venting expended cooling gas
out of the container. The means for venting expended
cooling gas out of the container includes a cooling plate
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into which gas is released and a tube for directing
expended gas from the plate to outside of the
container. By preventing direct contact between the
cooling gas and the cargo, live cargo, such as
5 animals, or other delicate cargo, such as fresh
flowers, can be transported in the container without
being asphyxiated or otherwise hurt or damaged by
the cooling gas.
In accordance with one aspect of the present
10 invention there is provided a shipping container for
shipping frozen and/or refrigerated cargo in an
unrefrigerated cargo area of a substantially larger
transport vehicle, including: a) a container having
an interior area with a volume to be loaded with the
15 frozen and/or refrigerated cargo with an access
opening that can be opened/closed; b) a refrigerant
tank mounted in the container for containing a
cryogenic liquefied refrigerant under pressure to be
utilized for cooling the container interior; c)
2o discharge piping means for piping liquefied
refrigerant from the tank; d) valve means
communicating with the discharge piping for valuing
the flow of liquefied refrigerant that is discharged
from the tank; e) temperature responsive controller
25 means for opening the valve means to dispense
liquefied refrigerant from the tank in order to
maintain a desired preselected preset refrigerated
or frozen temperature range within the container
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interior; f) wherein the liquefied refrigerant
converts to a gaseous phase downstream of the valve
means; and g) contact-prevention means for
preventing direct contact between refrigerant
5 dispensed from the tank and air in the interior area
of the container.
In accordance with another aspect of the
present invention there is provided a method of
transporting frozen and/or refrigerated cargo in an
i0 unrefrigerated cargo area of a substantially larger
transport vehicle or craft, including the steps of:
a) housing the products in an insulated container
with an interior for holding products that is
substantially smaller in volume than the cargo area;
15 b) cooling the container interior with a liquid
cryogenic refrigerant that is dispensed from a
canister that is contained within the container
interior; c) valuing the flow of liquid refrigerant
discharging from the canister using a liquid control
2o valve; d) controlling temperature within the
container interior by controlling the degree of
opening of the valve; and e) preventing direct
contact between refrigerant dispensed from the
canister and air in the interior area of the
25 container.
I i
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BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention can be
had when the detailed description of a preferred
embodiment set forth below is considered in
5 conjunction with the drawings, in which:
Figure 1 is a perspective partially cutaway
view of the preferred embodiment of the apparatus of
the present invention;
Figure 2 is a partial perspective view of the
l0 preferred embodiment of the apparatus of the present
invention illustrating an optional header system;
Figure 3 is a second embodiment of the
apparatus of the present invention;
Figure 4 is a fragmentary view of the preferred
15 embodiment of the apparatus of the present invention
illustrating the preferred valued construction for
the dual valve portion thereof;
Figure 5 is a side fragmentary view
illustrating the dual on/off valve portion of the
2o apparatus of the present invention;
Figure 6 shows a sectional elevational view of
the preferred embodiment of the apparatus of the
present invention illustrating a piping arrangement
used for charging the container and/or filling the
25 canisters;
Figure 7 is a perspective view of an embodiment
of the apparatus of the present invention having
means for controlling the atmosphere within a
container;
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Figure 8 is a sectional end view of the
apparatus shown in Figure 7;
Figure 9 is a perspective view of an embodiment
of the
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present invention utilizing a closed-loop system for
cooling a container.
Figure 10 is a perspective view of an embodiment of
the present invention which can be used to transport air
cargo.
Figure 11 is a schematic, elevational view
illustrating the shipping method of the present invention.
Figure 12 is a top, partially cut-away view of another
embodiment of the present invention, one which vents
expended cooling gas outside of the container.
Figure 13 is a side, partially cut-away view of the
embodiment of Figure 12.
Figure 14 is a schematic view illustrating the
operation of the cooling system of the embodiment of Figure
12.
Figure 15 is a front view of the embodiment of Figure
12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Figures 1 - 3 show generally the preferred embodiment
of the apparatus of the present invention designated
generally by the numeral 10.
In Figure 1, there can be seen an enlarged rectangular
transportable box-like container 12 having an upper surface
13 and a plurality of side walls 14, 15, 16, 17 forming an
enclosure with a bottom 18 portion of the container. The
bottom 18 includes a pair of spaced apart recesses 19, 20,
for example, which can be used to form a connection with
the times of a fork lift so that the container 10 can be
easily moved and transported about, such as during
unloading or loading of trucks or airplanes. Thus, the
present invention provides a method of transporting
refrigerated products within the interior of an
unrefrigerated dry-type truck (see Figure 11) comprising
the steps of first housing the products in an insulated
container 10 with an interior for holding products that is
substantially smaller in volume than the truck T cargo
interior volume. The container interior is cooled with a
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liquid cryogenic refrigerant that is dispensed from a
canister that is contained within the container interior.
The flow of liquid refrigerant is discharged from the
canister using a liquid control valve and the temperature
within the container interior is controlled by an opening
and closing of the valve. Thus, the truck T can contain
the containers 10 within the cargo area CA along with non-
refrigerated non-perishable goods designated generally by
the letter G in Figure 11. In Figure 11, a fork lift-type
lifting mechanism FL is shown lifting a container 10 into
the truck T cargo area CA.
The apparatus l0 can include an access doorway 21 that
would preferably be vertically oriented and pivotally
attached, having closure latches 22, 23 thus allowing
access through door 21 into the interior 24 of container
12. Container 12 would be manufactured, for example, of
welded stainless or welded aluminum construction. The
bottom section of container 12 defines a reservoir to hold
any water that accumulates during use. A valued drain 5
can be used to remove water during or after use from the
reservoir.
A hinged transverse perforated baffle 25 extends
across the upper portion of container 12 defining an
uppermost interior compartment 26 that contains canisters
27, 28. Baffle plate 25 is hingedly connected to container
rear wall 16 along edge 25A so that the baffle plate 25 can
swing down into a generally vertical position adjacent rear
wall 16 (when the apparatus is to be used for shipping
product in a cooled but not frozen condition). The baffle
plate 25 swings into a horizontal position as shown in
Figure 1, creating the confined compartment area 26 about
canisters 27, 28, when the apparatus is to be used for
shipping product in a frozen condition. Plate 25 is held
in the upper horizontal position using a latch (not shown)
or removable thumb screws or such like means.
Canisters 27, 28 are preferably canisters containing
liquid refrigerant, preferably carbon dioxide or a like
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refrigerant, such as nitrogen, and the canisters are
positioned upon their sides in a horizontal position, as
shown in Figures 1, 2 and 3. The plate 25 preferably
includes a plurality of perforations therethrough
designated as 29 in Figure 1. The canisters 27, 28 are
each equipped with exit valves 30, 31 which communicate
with header 32 that connects with manifold header 33
positioned generally between canisters 27, 28 and generally
parallel thereto, as shown in Figure 1. Manifold 33 has an
externally extended end portion 33A (Figure 6) that is an
inlet fitting which allows a "bulk" external source of
liquid refrigerant such as Co2 to be transmitted to the
manifold header 33 for two purposes as selectively desired.
- Firstly, the manifold header can "quick cool" the interior
24 with C02 from the bulk source before a shipment.
Normally, if frozen foods are being shipped, the baffle
plate is put in the upper position (Figure 1) and C02 is
blasted into the confined compartment 26 covering the
canisters 27, 28 and header with ice and generally filling
the area 26 with ice and snow. Secondly, the manifold can
be used to fill the tanks 27, 28 when they are empty.
A valve interfacing manifold 33 and header 32 controls
flow from manifold fitting 33A to either tanks 27, 28 (for
filling) or to header 33. The container 12 would
preferably be equipped with an externally mounted
temperature gauge 34 so that a user can view the internal
temperature 24 by viewing the thermometer 34, even when the
door 21 is closed.
Pressure gauge 35 could also extend externally of
container 12 so that the pressure within header 32 could be
viewed externally of the apparatus 10. In the embodiment
of Figure 1, the valves 30 and/or 31 would be opened
allowing carbon dioxide to flow through header 32 and into
perforated tube 33 so that C02 would enter the internal
portion 26 of box 12 above perforated plate 25 causing cold
air to refrigerate that portion of the box 12 interior 24.
The use of transverse plate 25 allows the interior 26
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of box 12 above plate 25 to be preliminarily frozen using,
for example, a blast of C02 from an external source, a
source other than canisters 27, 28 before the box is to be
shipped. This allows a frozen condition above plate 25
which supplements the amount of cooling that would
otherwise be required to keep the entire container 12 at a
particular refrigerated temperature. Thus, before
shipment, the common carrier would simply blast the
container for a specified period of time and quickly lower
the temperature of the container to reduce the work load on
the canisters. This allows the boxes to be shipped over
much longer distances than ordinarily would be possible if
only cooling from canisters 27, 28 were used.
The embodiment of Figure 2 is alternate construction
for the arrangement of canisters 27, 28 and the header and
valves. In the embodiment of Figure 2, designated
generally by the numeral 40, there can be seen a pair of
canisters 27, 28 having positioned therebetween an
elongated header 41 which is a gas exhaust header and
includes tube sections 42-46 which are generally parallel
and a plurality of elbow tubes 47-50 connecting the tube
sections, as shown in the drawings end to end, to form an
elongated header for gas exhaust.
A pair of dual on/off exhaust valves, (See Figures 4
and 5) 51, 52 each provide a gas feeder tube 53, 54 and a
liquid feeder tube 55, 56 respectively. A transverse flow
line 59 connects valves 51, 52 while a lowermost transverse
flowline 67 also connects the lower end portion of valves
51, 52. Pressure regulator 57 regulates the pressure of
gas leaving canisters 27, 28 through transverse header 59.
Discharge flowline 60 communicates with pressure regulator
57 and with dual temperature regulator valve 62.
A temperature probe 61 senses temperature within the
container 24 below baffle 25 so that the temperature probe
dictates when gaseous C02 is discharged through valve 62
through discharge line 63 which communicates with gas
exhaust header 41. Transverse flowline 67 receives liquid
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C02 from valves 51, 52 as the lines 55, 56 typically collect
liquid C02 from canisters 27, 28. Liquid C02 thus enters
liquid carrying heat exchanger coil 65 through flowline 68.
The liquid carrying heat exchange coil 65 can be provided,
as shown in the drawing, with a plurality of transverse
fins 70 for efficiency purposes in heat transfer between
the air within container 12 interior and the liquid-
carrying coil 65. Line 66 would be connected back to dual
temperature regulator valve 62 so that as the liquid could
become gaseous at valve 62, it also could be discharged
through outlet 63 into gas exhaust header 41. Header 72 is
preferably an elongated cylindrical tube having a plurality
of openings spaced along the length thereof, with an inlet
72A extending externally of the container 12 so that a bulk
C02 source can be used to preliminarily charge and cool
container 12. The header 72 could be piped (and
appropriately valued) to canisters 27, 28 so that the
canisters 27, 28 could be charged when empty from a bulk COZ
source via header inlet 72A. It should be understood that
the elongated header tube 72 is in communication with gas
exhaust header 41 so that the gas contained within header
41 eventually can be discharged through openings in header
tube 72. Valve 64 is provided to regulate flow between
canisters 27 and 28.
Figure 3 shows another embodiment 140 of the invention
wherein a transverse pan 75 is used immediately under the
gas exhaust header tubes. The pan 75 can wrap around the
canisters 27, 28 as shown to form a tray that holds ice and
snow.
Figures 4 and 5 show more particularly the
construction of dual on/off valves 51, 52 each comprising
a valve body 80 that communicates with a pair of internal
passageways 81, 82. The passageway 81 communicates with
tubes 53, 54 while the passageway 82 communicates with
tubes 55, 56. Transverse passageways 88, 89 communicate
respectively with externally extending transverse ports 86,
87 which preferably form connections with transverse
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headers 59, 67. Thus, header 59 connects to the uppermost
port 86 of valves 51, 52 while the lowermost port 87
connects with header 67. An opening of each valve by
rotating the spigots 83, 84 open the ports 88, 89 so that
flow can proceed respectively via tubes 53, 54 and
passageway 81 (with respect to the opening 88 and spigot
83) or via tubes 55, 56 through passageway 82 and opening
89. Thus using the dual valve of Figures 4 and 5, either
gas or liquid or both, could be removed from canisters 27,
28.
In Figure 6 there can be seen a piping detail which
specifies a piping arrangement that can be used to either
charge the canisters 27, 28 when they are empty, or blast
liquid or gas C02 directly into the container interior. The
inlet header 33 is equipped with an external fitting 33A
that extends beyond the container wall 14. The header 33
connects with a T 90 which carries a pressure indicator P.
A second downstream T 91 communicates with an elbow 92 that
is equipped with a valve 93. The valve 93 controls the
flow of fluid from T 91 through elbow 92 and downstream to
header 94 which is equipped with a series of perforations
or ports 95. When valve 93 is open, and a source of bulk
C02 attached at fitting 33, a large volume of liquid C02 or
C02 gas can be immediately charged into the container
interior via the header 94 and more particularly through
the series of ports 95.
When valve 93 is closed, the header 33 can be used to
either fill canisters 27, 28 through cross 950 which
contains a pair of lateral lines 96, 97 which would
communicate through appropriate piping with valves 30, 32
so that when valve 93 is closed, bulk C02 added through
fitting 33A can fill canisters 27, 28. Downstream of cross
950 is a pipe section 98 which communicates with
temperature responsive control valve 99 that communicates
with downstream affluent header 100 and more particularly
with the orifice fitting 101 portion thereof. This would
be a relatively small orifice opening 101. During use, the
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valve 93 would first be opened to charge the container 12
with a blast of C02 to lower the temperature. After this
initial blast from a bulk C02 source, the valve 93 would be
closed. Thereafter, the temperature responsive valve 99
would only open when needed to supply Co2 from canisters 27,
28 into the container interior by discharging the C02 into
the cross fitting 950 so that it could flow through the
valve 99 to the orifice 101. Thus, with the present
invention a bulk C02 source could be initially used to
greatly lower the temperature of the cargo and thereafter
the canisters would only be needed to maintain that
temperature. Thus, the bulk source could be used to supply
much of the cooling that was needed to lower the
temperature, with the canisters 27, 28 only being needed on
a maintenance basis after the shipment was sent.
Figure 7 is a perspective view of another embodiment
of the present invention, apparatus 110. Apparatus 110
comprises a container 112, and has means therein for
controlling the atmosphere of interior 124 of container
112. Although not shown in Figure 7, apparatus 110
preferably includes canisters 27 and 28, which may contain
nitrogen or carbon dioxide. Apparatus 110 preferably also
includes a canister (not shown) which contains oxygen. The
atmosphere of the interior 124 of container 112 is
controlled by a number of valves, including valves 83, 84,
183, 193, 199, 293, 299, and 399. Valves 83 control the
flow of nitrogen gas or carbon dioxide gas from canisters
27 and 28. Valves 84 control the flow of liquid carbon
dioxide or liquid nitrogen from canisters 27 and 28.
Valves 83 and 84 are hand regulating valves.
Valve 183 controls the flow of gaseous oxygen from a
container (not shown) containing oxygen. Three-way valve
193 allows bulk fill of canisters 27 and 28 with carbon
dioxide or nitrogen. Solenoid-actuated valve 199 controls
the injection of .liquid nitrogen or carbon dioxide.
Solenoid-actuated valve 399 controls the injection of
gaseous nitrogen or carbon dioxide. Three-way valve 293 is
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provided to allow bulk fill of the oxygen container (not
shown). Pressure regulator 157 controls the pressure in
the oxygen line.
Solenoid-actuated valve 299 is provided to allow
oxygen injection. Sensor 161 is connected to analyzer 132,
which has a maximum limit set point controller. Sensor 161
may be either a nitrogen or carbon dioxide sensor,
depending upon whether nitrogen or carbon dioxide is
contained in canisters 27 and 28. Likewise, analyzer 132
may analyze either nitrogen or carbon dioxide.
Sensor 261 senses oxygen content within interior 124
of container 112. Sensor 261 is connected to oxygen
analyzer 131. Analyzer 131 controls the amount of 02
between minimum and maximum limit set points.
Temperature sensor 61 is connected to temperature
controller 130. Temperature controller 130 includes a set
point. When the temperature inside interior 124 rises
above the set point, controller 130 causes solenoid-
actuated valve 199 to open to allow injection of nitrogen
or carbon dioxide into interior 124 to cool the contents of
container 112.
A rechargeable battery 120 provides electricity needed
to run analyzers 131 and 132, temperature controller 130,
and fans 135 and 136 (see Figure 8). Fans 135 and 136
helps circulate the gases within interior 124 so that the
temperature within container 112 is approximately uniform
throughout.
Apparatus 110 is useful when transporting materials
which require a controlled amount of oxygen (such as live
plants or animals).
Oxygen analyzer 131 and sensor 261 detect the amount
of oxygen in container 112. When the oxygen level drops
below the minimum limit set point, analyzer 131
communicates with solenoid-actuated valve 299 to allow more
oxygen to enter the interior 124 of container 112, until
the amount of oxygen reaches the maximum limit set point,
at which point valve 299 closes. Should the amount of
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oxygen rise above the maximum limit set point, then
analyzer 131 causes solenoid-actuated valve 399 to open,
allowing the emission of nitrogen or carbon dioxide gas
into interior 124 until the oxygen level is reduced below
the maximum limit set point.
Figure 9 is a perspective view of another embodiment
of the present invention, apparatus 210. Apparatus 210
includes a closed-loop cooling system. The cooling system
comprises a C02 slush vessel 127, cooling fins 128, valves
155, 193, and 199, a positive displacement diaphragm pump
150, and a fan 235 for forced air convection. When
temperature controller 130 detects that the temperature of
interior 224 of container 212 has risen above the pre-set
temperature, it causes positive displacement diaphragm pump
150 to pump C02 from vessel 127 through fins 128 and it
causes fan 235 to turn on. As the C02 moves through fins
128, it lowers the temperature of the fins, and fans 235
blows the cold gas downward in the interior 224 of
container 212. The C02 returns from fins 128 to C02 slush
vessel 127. Pressure relief valve 155 is provided to allow
pressure to be released from C02 slush vessel 127.
The use of apparatus 210 with its closed-loop cooling
system is advantageous when one does not wish to have the
cooling gas (carbon dioxide or nitrogen, for example) mixed
with the contents in the container 212.
Although container 212 is shown without a top, it
could include a flat top 17 as in containers 12 and 112, or
it could contain a curved top like the one in container 312
(see Figure 10).
Figure 10 shows another embodiment of the present
invention, apparatus 310. Apparatus 310 includes a
container 312 which has a top shaped to easily fit within
an aircraft. Container 312 may include any of the cooling
systems and controlled atmosphere systems discussed in
conjunction with the previous embodiments.
Container 312 preferably does not exceed 125 inches in
any dimension, and more preferably does not exceed 80
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inches in height, 90 inches in width, and 125 inches in
length.
Figures 12-15 show another embodiment of the present
invention, apparatus 410, which includes a cooling system
440 in a container 412. Apparatus 410 includes a means for
venting expended cooling gas out of container 412. The
means for venting expended cooling gas out of container 412
includes a cooling plate 441 into which gas is released and
a tube 442 for directing expended gas from plate 441 to
outside of container 412. By preventing direct contact
between the cooling gas and the cargo, live cargo, such as
animals, or other delicate cargo, such as fresh flowers,
can be transported in container 412 without being
asphyxiated or otherwise hurt or damaged by the cooling
gas. Otherwise, the functioning of apparatus 410 is
similar to that of the other embodiments, with pressure
regulator 57 cooperating with thermal expansion valve 457
and temperature responsive control valve 99 to keep the
interior of container 412 at a desired, predetermined
temperature.
Vent tube 442 preferably contains a back-pressure
regulator (not shown) to prevent air from outside container
412 from entering cooling system 440.
As can be seen in Figure 13, cooling system 440 is
positioned adjacent the top of container 412, in the upper
half of container 412. In this manner the cool air
adjacent cooling plate 441, being heavier than the warmer
air in the remainder of container 412, will settle to the
bottom of container 412, cooling the air in between.
While cooling plate 441 is preferably placed in the
upper part of container 412, adjacent the top thereof, it
could be placed adjacent a side of container 412. A fan
(not shown) could be used to circulate air withing
container 412.
Plate 441 has a coil 443 that receives coolant (see
Figure 14). Coil 443 cools plate 441, and plate 441 cools
the air in the interior of container 412.
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Cooling plate 441 could be replaced with an evaporator
core or another type of heat exchanger.
Container 412 may include any of the cooling systems
and controlled atmosphere systems discussed in conjunction
with the previous embodiments, as long as some means are
provided to prevent the cooling gas from being vented
directly into the air in container 412.
Container 412 includes a door 421, hinges 432 and 433,
and closure latches 422 and 423 for keeping door 421
closed.
Cooling plate 441 and vent tube 442 act as a contact-
prevention means for preventing direct fluid contact
between refrigerant dispensed from the tanks 27 and 28 and
air in the interior area of container 412. Cooling plate
441 is a chamber means in fluid communication with the
discharge piping and in thermal, but not fluid,
communication with the air in the interior area of
container 412.
Tube 442 is a tube means for directing refrigerant
from the interior of cooling plate 441 to exterior of
container 412 without coming into direct contact with the
air in the interior area of container 412.
Container 412 preferably does not exceed 125 inches in
any dimension, and more preferably does not exceed 80
inches in height, 90 inches in width, and 125 inches in
length.
In view of the numerous modifications which could be
made to the preferred embodiments disclosed herein without
departing from the scope or spirit of the present
invention, the details herein are to be interpreted as
illustrative and not in a limiting sense.
What is claimed as invention is:
