U.S. patent application number 09/825169 was filed with the patent office on 2002-02-21 for temperature controlling apparatus and method.
Invention is credited to Inbar, Michael, Kaplan, Yechezkel, Sharon, Igal, Simon, Amos.
Application Number | 20020020188 09/825169 |
Document ID | / |
Family ID | 23895679 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020188 |
Kind Code |
A1 |
Sharon, Igal ; et
al. |
February 21, 2002 |
Temperature controlling apparatus and method
Abstract
An apparatus and method for providing a controlled temperature
environment for an extended period of time. The apparatus comprises
a thermal chamber for holding a heat exchange substance, the heat
exchange substance having a reservoir temperature, and one or more
storage chambers for holding a storage specimen, wherein the
storage chambers are in thermal communication with the thermal
chamber through one or more insulation element, such that when the
thermal chamber is holding a heat exchange substance, each of the
storage chambers maintain a range of predetermined storage
temperature that is between the reservoir temperature and the
ambient temperature.
Inventors: |
Sharon, Igal; (Caesaria,
IL) ; Simon, Amos; (Yehud, IL) ; Kaplan,
Yechezkel; (Tel-Mond, IL) ; Inbar, Michael;
(D.N. Shimkin, IL) |
Correspondence
Address: |
PENNIE AND EDMONDS
1155 AVENUE OF THE AMERICAS
NEW YORK
NY
100362711
|
Family ID: |
23895679 |
Appl. No.: |
09/825169 |
Filed: |
April 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09825169 |
Apr 3, 2001 |
|
|
|
09477379 |
Jan 4, 2000 |
|
|
|
Current U.S.
Class: |
62/371 ;
62/457.1 |
Current CPC
Class: |
B65D 81/18 20130101;
B65D 81/3834 20130101; B65D 2577/042 20130101; B65D 81/3825
20130101 |
Class at
Publication: |
62/371 ;
62/457.1 |
International
Class: |
F25D 003/08 |
Claims
We claim:
1. An apparatus for providing a controlled temperature environment
different from the ambient temperature of the ambient environment
in which it is located, the apparatus comprising: (a) a thermal
chamber for holding a thermal exchange substance serving as either
a heat sink reservoir or a heat source reservoir and having a
reservoir temperature; (b) at least one insulation element
substantially surrounding the thermal chamber and insulating the
thermal chamber from the ambient environment; and (c) at least one
storage chamber located between the thermal chamber and the ambient
environment along the heat transfer path between the thermal
chamber and the ambient environment, wherein the at least one
storage chamber is in thermal communication with the thermal
chamber through the at least one insulation element, such that when
the thermal chamber contains the thermal exchange substance, at
least one of the storage chamber maintains a storage temperature
which is between the reservoir temperature and the ambient
temperature.
2. The apparatus of claim 1, wherein the reservoir temperature is
substantially lower than the ambient temperature.
3. The apparatus of claim 1, wherein the insulation element
comprises more than one material.
4. The apparatus of claim 1, further comprising at least a second
storage chamber and wherein the second storage chamber maintains a
second range of predetermined storage temperature different than
the range of predetermined storage temperature maintained by the
first storage chamber.
5. The apparatus of claim 2, wherein the thermal exchange substance
is selected from at least one of the group consisting of liquid
nitrogen, dry ice, ice-water, blue ice, and chemicals producing an
endothermic reaction, or combinations thereof.
6. The apparatus of claim 5, wherein the thermal exchange substance
is selected to maintain the range of predetermined storage
temperature that is selected from a temperature range of between
-196 deg. C and the ambient temperature.
7. The apparatus of claim 1, wherein the storage chambers are
provided within a lid and the lid is configured to close the
thermal chamber.
8. The apparatus of claim 1, wherein the reservoir temperature is
substantially higher than the ambient temperature.
9. The apparatus of claim 8, wherein the thermal exchange substance
is selected from at least one of the group consisting of water,
various oleic and non-oleic liquids having a boiling temperature
higher than that of water, including oleic acids, mineral oils,
ethylene glycol, and chemicals producing an exothermic reaction, or
combinations thereof.
10. The apparatus of claim 9, wherein the thermal exchange
substance is selected to maintain the range of predetermined
storage temperature that is selected from a temperature range of
between the ambient temperature and 100 deg. C.
11. The apparatus of claim 1, wherein the insulation element
comprises a vacuum condition.
12. The apparatus of claim 2, wherein the storage chamber is
designed and configured to maintain a range of predetermined
storage temperature between -20 deg. C and +4 deg. C.
13. The apparatus of claim 1, wherein the storage chamber is
designed and configured to maintain a range of predetermined
storage temperature between 90 deg. C and 100 deg. C.
14. The apparatus of claim 1, further including an outer shell
substantially surrounding the at least one insulation element.
15. The apparatus of claim 1, wherein the container is designed and
configured to maintain the range of predetermined storage
temperature for an extended period of time.
16. The apparatus of claim 1, wherein the storage chamber is
movable within the at least one insulation element by manipulating
from outside the container.
17. An insulated container for providing a controlled temperature
environment different than the ambient temperature in which the
container is located, the container comprising: (a) a main body
having at least one side wall, a bottom end, and an open top end;
(b) a thermal chamber located centrally within the main body for
holding a heat exchange substance having a reservoir temperature,
(c) at least one insulation element provided between the thermal
chamber and the exterior surface of the main body, where the
insulation element provides substantially equal insulation between
the thermal chamber and the container's exterior surface; (d) a lid
for covering the open top end, wherein the lid is formed of at
least one insulation element such that when the lid is closed, the
thermal chamber is insulated substantially equally on all sides;
(e) at least one storage chamber provided between the thermal
chamber and the container's exterior surface; and (f) one or more
sealing plugs provided on the lid for sealing the thermal chamber
and the one or more storage chambers, wherein the at least one
storage chamber is located at a predefined location between the
thermal chamber and the container's exterior surface such that the
at least one storage chamber maintains a range of predetermined
storage temperature that is between the reservoir temperature and
the ambient temperature.
18. The apparatus of claim 17, wherein the at least one insulation
element comprises more than one material.
19. The apparatus of claim 18, wherein the thermal conductivities
of the different insulation elements are different from one
another.
20. The apparatus of claim 17, further comprising a second storage
chamber wherein the storage chamber maintains a second range of
predetermined storage temperature different than the range of
predetermined storage temperature maintained by the first storage
chamber.
21. The apparatus of claim 17, wherein the storage chambers are
provided within the lid wherein the lid is configured to cover the
thermal chamber.
22. The apparatus of claim 17, wherein the insulation element
comprises a vacuum condition.
23. A method of protecting a specimen from the ambient temperature,
the method comprising the steps of: (a) providing a container
having a main body, at least one side wall, a bottom end, and an
open top end; (b) providing a thermal chamber located centrally
within the main body for holding a thermal exchange substance
having a reservoir temperature which is substantially different
than ambient temperature; (c) substantially surrounding the thermal
chamber with at least one insulation element so that the insulation
element provides substantially equal insulation between the thermal
chamber and the container's exterior surface; and (d) providing at
least one storage chamber at a predetermined location between the
thermal chamber and the container's exterior surface to hold the
specimen, such that the storage chamber is in thermal communication
with the thermal chamber through the at least one insulation
element such that the storage chamber maintains a range of
predetermined storage temperature which is between the reservoir
temperature and the ambient temperature.
24. The method of claim 23, further comprising the step of placing
the specimen in the storage chamber.
25. The method of claim 23, wherein the specimen is a biological
sample.
26. An apparatus for providing a controlled temperature environment
different from the ambient temperature of the ambient environment
in which it is located, the apparatus comprising: (a) a thermal
chamber centrally located within the container for holding a
thermal exchange substance serving as either a heat sink reservoir
or a heat source reservoir and having a reservoir temperature; (b)
at least one insulation element substantially surrounding the
thermal chamber on all sides and insulating the thermal chamber
from the ambient environment; and (c) at least one storage chamber
located between the thermal chamber and the ambient environment
along a heat transfer path between the thermal chamber and the
ambient environment, wherein the at least one storage chamber is in
thermal communication with the thermal chamber through the
insulation element, such that when the thermal chamber contains the
thermal exchange substance, at least one of the storage chamber
maintains a range of predetermined storage temperature which is
between the reservoir temperature and the ambient temperature.
Description
[0001] This is a continuation-in-part of Application Ser. No.
09/477,379, filed on Jan. 4, 2000, entitled "Temperature
Controlling Apparatus and Method." This application also claims the
benefit of priority based on the PCT Application No.
PCT/IL00/00859, filed on Jan. 4, 2001, entitled "Temperature
Controlling Apparatus and Method."
FIELD OF THE INVENTION
[0002] The present invention relates to an improved insulated
container for maintaining one or more items or material, and more
particularly temperature sensitive items, within a limited range of
temperatures for a period of time for the insulated container more
particularly for shipping or temporarily storing the items or
material. More particularly, the container is directed to
containers for storing and shipping biological samples, material,
and tissue.
BACKGROUND OF THE INVENTION
[0003] Numerous container systems for maintaining their contents at
a constant temperature have been previously disclosed. Such
containers are often utilized for maintaining the temperature of
cold or hot materials. The materials are often placed within an
insulated container with insulated walls that are designed to limit
the flow of thermal energy between the content materials and the
ambient environment of the container. Examples are traditional
coolers and Thermos.TM. bottles.
[0004] In this type of prior art containers, the period of time
which the container can maintain the temperature of its content
material is limited by the heat capacity of the content material
itself. Hence, such containers are not well suited for holding
small quantities of material because the thermal mass is small.
Where the thermal mass of the content material is small, these
containers are only capable of maintaining the desired temperature
of the content material for a relatively short period of time.
Other variations of this type of containers are described in U.S.
Pat. Nos. 3,045,980, 4,755,313, 4,232,532, and 5,845,499.
[0005] Another type of container for maintaining the temperature of
material include a heat exchange substance that function as a heat
source or a heat sink to increase the length of time the container
can store the material. A picnic cooler filled with ice and
beverages is an example. The ice acts as the heat sink and keeps
the beverages cold for a substantially longer period of time than
if the beverages were just chilled and then stored in an empty
cooler.
[0006] In a variation of the picnic cooler, U.S. Pat. No. 5,924,302
to Derifield describes an insulated shipping container to maintain
temperature sensitive material in a refrigerated condition for an
extended period of time. The container has an insulated body with a
centrally located storage chamber for holding the temperature
sensitive material to be shipped. The container also has one or
more additional chambers in the insulated body for holding coolant
material and the coolant chambers are positioned around the storage
chamber so that they are between the storage chamber and the
ambient surrounding of the container.
[0007] The container described in the Derifield patent may use
coolants, such as, packaged ice, gel packs, or dry ice (frozen
CO.sub.2) to act as a heat sink. The coolant chambers and the
storage chamber may be completely separated by insulation material
for keeping the product being shipped at a refrigerated, but not
frozen, condition. Alternatively, the coolant chambers and the
storage chamber may be connected via one or more passages, exposing
the product more directly to the temperature of the coolant,
thereby maintaining the product in a substantially frozen
condition.
[0008] However, the container of Derifield patent is not capable of
shipping multiple products with each product being maintained at
different temperatures nor capable of allowing the user to readily
select a particular storage temperature for each storage
chamber.
[0009] U.S. Pat. No. 4,294,079 to Benson describes an insulated
storage container for temperature control of chilled perishables
during shipment. The container of the Benson patent has a storage
chamber with an opening on top and an insulated lid for sealing the
opening. Within the lid is a second chamber for holding a supply of
dry ice. The second chamber is in communication with the main
storage chamber via several holes that are provided in the lid. The
supply of dry ice functions as a heat sink to keep the pre-chilled
goods that are in the storage chamber in chilled condition. The
second chamber is substantially smaller than the main storage
chamber and the container is only adequate for maintaining the
pre-chilled contents at the generally chilled condition.
[0010] Another example, U.S. Pat. No. 5,417,082 to Foster et al.,
describes an insulated container for maintaining a product at a
constant user-selected temperature during shipping or storage using
two heat exchange substances. The container has two thermal
chambers, each holding a heat exchange substance at different
temperatures. One or more storage chambers are provided between the
two thermal chambers to maintain a temperature that is within the
range of temperatures defined by the thermal gradient created
between the two heat exchange substances. By varying the material
and/or the thickness of the insulation layers between the one or
more storage chambers and the two thermal chambers, different
desired constant storage temperatures may be selected. The
container of the Foster patent has the impracticality of requiring
the use of two heat exchange substances.
[0011] Therefore, a need exists for a simplified insulated shipping
container which provides a limited range of storage temperatures,
more preferably one which utilizes only one heat exchange
substance, more preferably while minimizing the effect of the
ambient temperature fluctuations so that minimal quantity of heat
exchange material is necessary, more preferably maintains a limited
range of storage temperatures for an extended period of time, more
preferably maintains a predetermined limited range of temperatures
for a predetermined time period based upon a proscribed ambient
environment in which the container is positioned, more preferably
maintains a user-selected range of storage temperatures, and more
preferably, a constant predetermined storage temperature.
SUMMARY OF THE INVENTION
[0012] According to one aspect of the present invention there is
provided a container for providing a controlled temperature
environment, the container comprising a centrally located thermal
chamber for containing a heat exchange substance serving as either
a heat sink reservoir or a heat source reservoir and having a
reservoir temperature (hereinafter "Tr"); and one or more storage
chamber located between the thermal chamber and the ambient
environment or exterior of the container such that the storage
chambers are part of the heat transfer path between the thermal
chamber and the ambient environment. The storage containers
preferably are in thermal communication with the thermal chamber
and the ambient environment through at least one insulation
element, such that when the thermal chamber contains a heat
exchange substance, the one or more storage chambers maintain a
storage temperature (hereinafter "Ts") which is between Tr and the
ambient temperature (hereinafter "Ta").
[0013] The container preferably provides a controlled temperature
environment for an extended period of time, preferably greater than
one or two hours. The container of the invention achieves this by
its ability to retain the Tr for an extended period of time. The
thermal chamber is preferably located centrally within the
container so that the thermal chamber is substantially equally
insulated from the ambient environment in all directions.
[0014] It is further preferred that at least one storage chamber be
designed and configured to maintain a Ts in the range of -20 deg.
C. to 4 deg. C., where the container utilizes a heat sink materal.
In a different container it may be preferred that at least one
storage chamber be designed and configured to maintain a Ts in the
range of approximately 19 deg. C. to 100 deg. C.
[0015] The heat exchange substance serves as the heat sink
reservoir if the desired Ts is higher than the Tr, and the
substance serves as the heat source reservoir if the desired Ts is
lower than the Tr.
[0016] As used herein, the term "heat sink" refers to a heat
exchange substance used to draw heat away, in this case, from
storage chambers to maintain a Ts which is lower than Ta. A
preferred heat exchange substance for use as a heat sink is a
substance undergoing phase transformation, i.e., transforms from
solid into liquid (liquidizes), from solid into gas (sublimes), or
from liquid into gas (evaporates), because they maintain a constant
temperature. Examples of a heat sink material are liquid nitrogen,
dry ice (solid CO.sub.2), ice water, blue ice (a mixture of DI
water, urea and ammonium chloride), and liquid oxygen under STP
conditions, or combinations thereof. Another example of a heat sink
substance includes reaction mixtures and chemicals capable of
undergoing a controlled endothermic reaction which reaches a steady
state temperature in a given environment.
[0017] In comparison, as used herein, the term "heat source" refers
to a heat exchange substance having a temperature which is above Ta
which may be used to maintain a Ts which is higher than the Ta.
Some examples of a heat source substance includes heated oil,
heated water, ethylene glycol, non-oleic liquids having a boiling
temperature above 100 deg. C., and reaction mixtures or chemicals
capable of undergoing a controlled exothermic reaction or
combination thereof.
[0018] It is preferable that the heat sink or heat source substance
used in the container of the present invention be a substance
having high specific heat capacity, so that it heats or cools at a
slow rate.
[0019] For a given set of values for Tr and Ta, Ts may be
determined by the following variables: the thermal conductivity of
the one or more insulation elements between the thermal chamber and
the storage chamber; the thermal conductivity of the one or more
insulation elements between the storage chamber and the ambient
environment; and the geometry of the container and the storage and
thermal chambers.
[0020] Although Tr is preferably a fixed constant temperature for a
given heat exchange substance, it is contemplated that the ambient
temperature may fluctuate, particularly where the container is used
for shipping substances. The fluctuations in Ta (hereinafter
".DELTA.Ta") may result in some limited fluctuations in Ts (herein
after ".DELTA.Ts"). Thus, for a fluctuating ambient environment, it
is preferred that any given storage chamber in the container of the
present invention maintain a narrow range of temperatures.
[0021] In some embodiment of the container, the closer Tr is to Ts,
the smaller the .DELTA.Ts at the storage chambers will be as a
result of .DELTA.Ta. In such cases, it is preferable to select a
heat exchange substance which will provide a Tr that is
sufficiently close to the desired Ts in order to minimize the
effect of any .DELTA.Ta, should the container be exposed to changes
in the ambient temperature.
[0022] The container of the present invention may be configured
such that each of the one or more storage chambers have
predetermined Ts with associated .DELTA.Ts when the container is
used or exposed in environment(s) where the Ta is within the range
of temperatures intended for the container. This may be achieved by
controlling one or more of the thermal variables discussed above,
such as, the heat exchange substance, the geometry of the storage
chamber and the thermal chamber, the geometry and/or the material
of the insulation surrounding the storage chamber, etc.
[0023] For example, a storage chamber of the container of the
present invention may be configured for a particular range of
temperatures by controlling the particular location of the storage
chamber between the thermal chamber and the ambient environment
while using a fixed set of insulation material. Alternatively, the
location of the storage chamber may be fixed and the insulation
materials used in the container may be varied to achieve a desired
range of temperatures at the storage chamber.
[0024] The container of the present invention may be configured so
that the container is initially provided to the user with a set of
interchangeable insulation elements and storage chambers that are
provided in a variety of materials and geometries so that the user
may select and customize the container with one or more storage
chambers with desired ranges of storage temperatures Ts for the
particular ambient conditions in which the user plans to use the
container. For example, the container may be provided with a
variety of insulation pieces that fit together to form one or more
storage chambers of appropriate size(s) and shape(s) at different
location(s) within the container to achieve desired range(s) of
storage temperatures, preferably with a narrow .DELTA.Ts.
[0025] The container of the present invention may be configured so
that each of the storage chambers maintain a range of Ts that is
different from the range of Ts maintained by any of the other
storage chambers. For example, a first storage chamber may be
located either closer to or further from the thermal chamber than a
second storage chamber and therefore maintain a different range of
Ts than the other storage chambers.
[0026] In another embodiment of the invention, the first and the
second storage chambers may be located equidistant from the thermal
chamber but the insulation material between the second storage
chamber and the thermal chamber may have a higher or a lower
thermal conductivity than the insulation material between the first
storage chamber and the thermal chamber to achieve a range of Ts
different from the range of Ts maintained at the first storage
chamber.
[0027] Each of the one or more insulation elements may also include
a plurality of insulation layers, where each of the plurality of
insulation layers may be different insulation material having
different thermal conductivity.
[0028] According to another aspect of the present invention there
is provided a method of providing a controlled temperature
environment for an extended period of time, the method comprising
the steps of providing a thermal chamber containing a heat exchange
substance serving as either a heat sink reservoir or a heat source
reservoir and having a reservoir temperature, Tr; providing one or
more storage chambers for holding material to be; and locating the
storage chambers in thermal communication with the thermal chamber
and the ambient environment such that the storage chambers are part
of the heat transfer paths between the thermal chamber and the
ambient environment. The method provides the further step of
locating the storage chambers so they are surrounded by at least
one insulation element that occupy the space between the thermal
chamber, the storage compartments, and the ambient environment.
[0029] In one embodiment, the container is designed and configured
to be small, light weight and portable while having the capacity to
maintain the temperature of the storage temperature for greater
than 12 hours, more preferably greater than 24 hours, more
preferably greater than 24 hours with a minimal amount of heat
exchange material, more preferably greater than 72 hours with a
minimal amount of heat exchange material.
[0030] The invention will now be illustrated in some specific
embodiments. It will be appreciated by those skilled in the art
that the same principles are also applicable in other applications
and areas where a container is desired for providing a user with
ability to store and/or ship items in controlled predetermined
temperature ranges for an extended period of time using only one
heat exchange material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The invention will now be described with reference to the
Figures which illustrate preferred embodiments of the invention,
which invention should not be limited to such preferred embodiments
but only by the claims, wherein, FIG. 1 is an exploded perspective
view of an embodiment of the storage container of the
invention;
[0032] FIG. 2 is a vertical cross-sectional view of the container
illustrated in FIG. 1;
[0033] FIG. 2a is a vertical cross-sectional view of another
embodiment of the container illustrated in FIG. 2.
[0034] FIG. 3 is a horizontal cross-sectional view of the main body
portion of the container illustrated in FIG. 1;
[0035] FIG. 4 is a horizontal cross-sectional view of another
embodiment of the container of the present;
[0036] FIG. 5 is a horizontal cross-sectional view of the container
of FIG. 4 illustrating another configuration for the storage
chambers;
[0037] FIG. 6 is a vertical cross-sectional view of another
embodiment of the container.
[0038] FIG. 7 is a vertical cross-sectional view of another
embodiment of the container with a storage chamber that is movable
between different temperature zones.
[0039] The drawings are only schematic and are not to scale.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0040] Referring now to the drawings, FIGS. 1, 2, and 3 illustrate
one embodiment of the container of the present invention which has
a box-like configuration. In FIG. 1, container 10 is shown having a
main body 12 and a lid 14.
[0041] The main body is provided with a centrally located thermal
chamber 15 for holding a heat exchange substance that will function
as a heat sink or a heat source depending on the desired range of
Ts's. Thermal chamber 15 is preferably centrally located within in
container 10 so that when lid 14 is closed, the chamber is
surrounded by insulation elements 16a and 16b preferably
substantially equally on all sides from the ambient
environment.
[0042] The container may be constructed in such a manner so that
both the main body and the lid may have outer shells 18. Outer
shells 18 are exposed to the ambient temperature of the environment
in which the container 10 is placed.
[0043] Outer shells 18 may be made from substantially rigid
material to provide a protective outer layer for container 10 and
may also provide insulation from the ambient environment, depending
on the particular material selected to form the shells. Outer
shells 18 may be solid or have a hollow structure, in which case,
it may be filled with one or more different insulating materials or
may maintain an evacuated condition.
[0044] Each insulation elements 16a and 16b may be constructed as a
composite of one or more materials or it may be divided into
multiple sections where each section is formed from one or more
insulation materials.
[0045] Thermal chamber 15 may also be provided with an internal
wall of material different from insulation elements 16a and 16b
which defines the thermal chamber. The internal wall (not shown)
may be formed of one or more layers of material. The main body is
also provided with at least one specimen storage chamber 20, 21,
22, 23, and 25 for holding specimens. A specimen may be placed in
the storage chamber directly or use an appropriate container such
as an ampoule or similar receptacle. Hence, the storage chambers
may be formed in a variety of shapes to accommodate particular
specimens and their receptacles.
[0046] The thermal chamber and the specimen storage chambers may
have corresponding plug portions 14a and 14b which serve as covers.
Plug portions 14a and 14b may be located on the lid so that when
the lid is closed over the main body each plug portions fit into
the corresponding chambers in the main body portion and function as
covers for each individual chambers as can be seen in the vertical
cross-sectional illustration of FIG. 2. In embodiments where dry
ice or other subliming substance is used as the heat exchange
substance, the plug 14a for the thermal chamber and the seal
provided by lid 14 preferably allows the gas produced by
sublimation to escape to the ambient environment in order to
prevent any pressure build up inside the container.
[0047] The plug portions provided in the lid for sealing the
storage chambers may be formed with a variety of shapes and
materials suitable for sealing a particular storage specimen. In
certain applications, the plugs may not be necessary or desired.
For example, the storage specimen may be placed in a sealed ampoule
or in a series of nested containers, where each container provides
redundant sealing functions. The assembly may then be placed in a
storage chamber without the need for a plug such as 14b to seal the
storage chamber.
[0048] FIG. 3 illustrates the horizontal cross-section of the main
body of the container of FIGS. 1 and 2. In this embodiment, the
specimen storage chambers 20, 21, 22, 23, and 25 are positioned at
different locations so that each of the three storage chambers can
maintain a different range of Ts. The insulation element 16a may
consist of, for example, one insulation material which fills the
space between the outer shell of the container and the thermal
chamber and substantially surrounds the storage chambers.
[0049] The storage temperature at each of the storage chambers will
be a temperature between the Ta and the thermal chamber's Tr. And
in FIGS. 1-3, because the storage chambers 20, 21, 22, 23, and 25
are located at different distances from the thermal chamber, each
storage chamber will maintain a different range of Ts.
[0050] A prototype of the container substantially as shown in FIGS.
1-3 was constructed from polyurethane. The polyurethane prototype
container was covered with an outer shell of aluminum foil. The
interior wall of the thermal chamber was formed with a layer of
aluminum foil. The box-like container was a cube with an outer
dimension of 420 mm on each side. The centrally located thermal
chamber was also a cube located in the center of the container
having sides measuring 140 mm. A storage chamber was located
between the thermal chamber and the exterior wall of the container
along the container's center line and located similar to the
storage chamber 22 shown in FIG. 1. The storage chamber had a
cylindrical shape with a diameter of about 10 mm and a height of
about 25 mm. The center of the storage chamber was located
approximately 129 mm from the center of the thermal chamber.
[0051] The thermal chamber was filled with 3 kg of dry ice as the
heat sink substance and the container was placed in an environment
which was approximately 23 deg. C. Upon reaching a steady state
condition, a temperature of -79 deg. C. was maintained in the
thermal chamber while a temperature of about -18 deg. C was
maintained at the storage chamber for 120 hours.
[0052] FIG. 2a illustrates other embodiments of the container of
FIG. 2. In this embodiment, one or more storage chambers 24 may be
located underneath thermal chamber 15 and one or more storage
chambers 26 may be located in lid 14 within insulation element 16b.
Insulation element 16c provides the insulation between storage
chamber 24 and the thermal chamber. Insulation element 16c may be
constructed as an assembly of one or more materials or formed as a
composite of multiple materials.
[0053] Storage chamber 24 in FIG. 2a is particularly beneficial
when a substance such as dry ice is used in the thermal chamber as
a heat sink. Through sublimation, the volume of the dry ice reduces
over time and the dry ice tends to recede away from the top portion
of thermal chamber 15 towards the bottom of the chamber. Therefore,
locating the storage chamber underneath thermal chamber 15 helps
maintain the relative position of the storage chamber to dry ice
for a longer period of time and thus maintain the thermal
communication between the storage chamber and the dry ice. To
further enhance this particular feature of this configuration, the
lid portion of the container may be provided with a spring-loaded
plunger mechanism that pushes down on the dry ice in the thermal
chamber. So that as the dry ice sublimes the remaining dry ice is
pushed towards the bottom of the thermal chamber.
[0054] Storage chambers 26 of this embodiment are also located
between the thermal chamber and the ambient environment. And as in
the other embodiments, the range of Ts maintained at each of the
storage chambers provided within the lid will be between Ta and Tr.
The desired range of Ts for a given storage chamber may be
determined by varying the insulation material surrounding the
storage chamber, or by varying the geometry of and between the
storage chamber, the thermal chamber, and the container or the
location of the storage chamber within the lid in relation to the
thermal chamber and the ambient environment. As with the other
embodiments of the storage container discussed above, insulation
element 16b may be comprised of one or more insulation
materials.
[0055] As discussed for the container embodiment of FIG. 1, storage
chambers 22, 23, 24, 25, and 26 may be configured in any shape
appropriate for storing particular storage specimens or specimen
receptacles and the specimens may be directly placed in the storage
chambers or first placed in appropriate ampoules or similar
receptacles.
[0056] FIG. 2a illustrates another possible configuration for outer
shell 18, where the outer shell may preferably comprised of a low
emissivity material and my include an internal space 19 which may
preferably be in a vacuum condition for insulation purposes. In
this regard, the outer shell should be composed of material, and
designed and configured to maintain the vacuum condition of
internal space 19. For purposes of this application, the vacuum
condition constitutes an insulation element. Outer shell 18 also
may be of such structure and material for holding liquids, such as
for example, liquid nitrogen, as the heat exchange substance in
thermal chamber 15. Outer shell 18 also may be a rigid insulation
material. Alternatively, the internal space 19 may also be filled
with a solid or liquid insulation material as appropriate.
[0057] FIG. 4 illustrates an embodiment of the invention where the
container has a cylindrical configuration. FIG. 4 is a horizontal
cross-sectional view of a cylindrical container 30 having a main
body portion 32, an outer shell 38, thermal chamber 35, storage
chambers 40, 42, and 44, and insulation element 36 comprised of,
for example, a single insulation material. As illustrated, storage
chambers 40, 42, and 44 are located at different distances from
thermal chamber 35 and hence the range of storage temperatures
maintained at each of the storage chambers will be different. As
discussed when referencing the container of FIG. 3, the storage
chambers are positioned between the exterior of the container and
the thermal chamber and the storage temperature at each storage
chamber 40, 42, and 44 will be a temperature between Ta and Tr.
[0058] FIG. 5 illustrates another variation of the embodiment of
the container of FIG. 4. In FIG. 5, the container's insulation
element 36 includes more than one insulation material. Storage
chamber 40' is substantially surrounded by an insulated region
formed by insulation elements 36a and 36a'; storage chamber 42' is
substantially surrounded by an insulated region formed by
insulation elements 36b and 36b'; and storage chamber 44' is
substantially surrounded by an insulated region formed by
insulation elements 36c and 36c'. Each of the insulation elements
36a, 36a', 36b, 36b', 36c and 36c' may represent different
insulation material so that each insulation element has different
thermal conductivity and, hence, different thermal insulation
capabilities.
[0059] As illustrated in FIG. 5, in this embodiment, storage
chambers 40', 42', and 44' are located equidistant from thermal
chamber 35. Since the storage temperature at any given storage
chamber is a function of the thermal conductivity of the insulation
material surrounding the storage chamber and the distances between
the storage chambers, the thermal chamber, and the outer surface of
the container, in this example, the storage temperatures for the
different storage chambers may be differentiated by varying the
insulation material used to surround each of the storage
chambers.
[0060] For example, storage chamber 40' is substantially surrounded
by insulation elements 36a and 36a' and storage chamber 42' is
substantially surrounded by insulation elements 36b and 36b'. The
relative differences in the thermal conductivities between 36a and
36b, and 36a' and 36b' will determine the difference in the storage
temperatures of storage chambers 40' and 42'.
[0061] Each of the insulation elements shown in the embodiments
illustrated in FIGS. 1 through 5 may be further comprised of one or
more layers of one or more insulation materials as necessary to
obtain the desired range of Ts's at the storage chambers.
[0062] FIG. 6 illustrates an embodiment of the container where main
body 52 of container 50 has a thermal chamber for holding the heat
exchanger substance and the storage chambers are provided within a
lid 54 which seals the thermal chamber. Main body 52 forms a
thermal chamber 55 for holding a heat exchange substance and may be
provided with an outer shell 58 which is preferably comprised of a
low emissivity material. The outer shell may include an internal
space 57 which may preferably be in a vacuum condition for
insulation purposes. In this regard, the outer shell should be
composed of material, and designed and configured to be under a
vacuum condition. Outer shell 58 also may be of such structure and
material for holding liquids, such as for example, liquid nitrogen
as the heat exchange substance in thermal chamber 55. Outer shell
58 also may be a rigid insulation material. Alternatively, the
internal space 57 in outer shell 58 may also be filled with other
insulation material as appropriate.
[0063] The thermal chamber is covered by a lid 54 which contains
one or more storage chambers 60 and may preferably be constructed
of an insulation material 56. The lid may also have an outer shell
59. The outer shell 59 may be formed of a rigid material for
structural or protective purposes and/or it may be formed of an
insulation material where appropriate. The lid may seal the thermal
chamber.
[0064] As discussed for the container embodiment of FIG. 1, the
storage chambers may be provided with any shape appropriate for
storing the particular storage specimen or specimen receptacles and
the specimen may be directly placed in the storage chambers or
first placed in an appropriate ampoule or a similar receptacle.
[0065] As in the containers illustrated in FIGS. 1-5, storage
chambers 60 of this embodiment are also located between the thermal
chamber and the ambient environment. And as in the other
embodiments, the range of Ts maintained at each of the storage
chambers provided within the lid will be between Ta and Tr. The
desired range of Ts for a given storage chamber may be determined
by varying the insulation material surrounding the storage chamber,
or by varying the geometry of and between the storage chamber, the
thermal chamber, and the container or the location of the storage
chamber within the lid in relation to the thermal chamber and the
ambient environment. As with the other embodiments of the storage
container discussed above, insulation material 56 may be comprised
of one or more insulation elements.
[0066] In the embodiments of the containers illustrated in FIGS.
1-6, it will be appreciated that Ta, which depends upon the
environment(s) in which the container is placed may fluctuate. In
order to minimize the effects of fluctuations in Ta, the heat
exchange substance may be selected so that the difference between
the Ts and Tr is minimized.
[0067] FIG. 7 illustrates another embodiment of the invention where
a container may be provided with one or more storage chamber where
within each storage chamber a temperature gradient is maintained so
that the storage chamber may be moved into one or more temperature
zones. Container 70 may be provided with a main body portion 72
within which is provided a thermal chamber 75 for holding a heat
exchanger substance. The container may also be provided with a lid
74 for covering the thermal chamber. The lid may seal the thermal
chamber.
[0068] The lid and the main body portions may be constructed with
insulation material 76 where the insulation material may be
constructed from one or more insulation elements. Insulation
material 76 may be a composite of one or more insulation material
or an assembly of one or more sections. The lid and the main body
portion may also have rigid outer shell 78 similar to the outer
shell structures discussed when referencing FIGS. 1-5.
[0069] In this embodiment, the main body portion may be provided
with one or more storage chambers. One such storage chamber 80 is
shown in FIG. 6. The storage chamber is located within the main
body 72 in a slanted or inclined orientation, such that, its bottom
end 81 is closer to the thermal chamber and its top open end 83 is
closer to the exterior of the container. The top end of the storage
chamber may protrude through the outer shell of the container.
[0070] Located within the storage chamber is a specimen holder 84
which is provided with a specimen chamber 82 for holding a specimen
for storage. The specimen holder is connected to a plunger 86, the
opposite end of which extends out from the storage chamber 80 so
that a user may manipulate the plunger to move the specimen holder
up and down the storage chamber by sliding the plunger within
storage chamber 80. The plunger may be provided with a knob or a
handle 88 on its top end to allow the user to manipulate the
plunger. A stopper 85 may be provided at the top open end of the
storage chamber for sealing the storage chamber and also provided
with a hole through which the plunger slides. To place a specimen
in the specimen holder, the stopper may be removed so that the
plunger can be removed from the storage chamber.
[0071] Storage chamber 80 is substantially surrounded by insulation
material 76 and a substantial portion of the storage chamber is
located between the thermal chamber and the ambient environment.
Because the slanted orientation of the storage chamber results in
different portions of the storage chamber being at different
distances from the thermal chamber (and hence, at different
distances from the ambient environment), the different portions of
the storage chamber along its length should be at different
temperatures. In other words, a temperature gradient is formed
along the length of the storage chamber.
[0072] The user may then manipulate plunger 86 to position specimen
holder 84 within storage chamber 80 at a position corresponding to
the desired Ts. As discussed when referencing FIGS. 1-6, the
selected position for the specimen holder may actually maintain a
range of Ts, since Ts may fluctuate in response to potential
fluctuations in Ta. It will be appreciated that the temperature
gradient within storage chamber 80 may be modified by varying the
insulation materials surrounding the storage chamber.
[0073] Because Ta depends on the environment(s) in which the
container is placed, Ta will fluctuate. In order to minimize the
effects of fluctuations in Ta, the heat exchange substance may be
selected so that the difference between the Ts and Tr is minimized
relative to the difference between the Ta and Tr.
[0074] It will be appreciated from these discussions, to one
skilled in the art that a desired storage temperature for a given
storage chamber may be obtained by varying the heat exchange
substance; the geometry of and between the storage chamber, the
thermal chamber, and the outer surface of the container; the
insulation material surrounding the storage chamber; and the
geometry of the insulation material surrounding the storage
chamber.
[0075] The above descriptions are intended only to serve as
examples, and that many other embodiments are possible and
encompassed within the spirit and the scope of the present
invention. Thus, the scope of the present invention is not to be
limited by the described 10 preferred embodiments but only by the
following claims.
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