U.S. patent application number 11/167992 was filed with the patent office on 2007-08-09 for system for maintaining materials at freezer temperatures for shipping.
This patent application is currently assigned to The University of Wyoming Research Corporation d/b/a Western Research Institute, The University of Wyoming Research Corporation d/b/a Western Research Institute. Invention is credited to John F. Schabron, Susan S. Sorini-Wong.
Application Number | 20070180847 11/167992 |
Document ID | / |
Family ID | 38332610 |
Filed Date | 2007-08-09 |
United States Patent
Application |
20070180847 |
Kind Code |
A1 |
Schabron; John F. ; et
al. |
August 9, 2007 |
SYSTEM FOR MAINTAINING MATERIALS AT FREEZER TEMPERATURES FOR
SHIPPING
Abstract
At least one embodiment of the inventive technology relates to a
frozen environmental sample temperature control system that
comprises a frozen formulation having water in an amount from
substantially 87% to 78% by weight of the formulation, and salt in
an amount from substantially 13% to 22% by weight of the
formulation, the system further including at least one container
containing the frozen formulation; and a cooler having insulating
material disposed between an outer wall and an inner surface that
defines an inner chamber into which the at least one container and
the at least one frozen environmental sample may be placed for
storage and/or transport. Various embodiments may incorporate
specific types of insulating material and/or adaptations to an
inner surface of the cooler to enhance the insulation effected
thereby.
Inventors: |
Schabron; John F.; (Laramie,
WY) ; Sorini-Wong; Susan S.; (Laramie, WY) |
Correspondence
Address: |
SANTANGELO LAW OFFICES, P.C.
125 SOUTH HOWES, THIRD FLOOR
FORT COLLINS
CO
80521
US
|
Assignee: |
The University of Wyoming Research
Corporation d/b/a Western Research Institute
Laramie
WY
|
Family ID: |
38332610 |
Appl. No.: |
11/167992 |
Filed: |
June 27, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60583177 |
Jun 25, 2004 |
|
|
|
Current U.S.
Class: |
62/371 ;
62/530 |
Current CPC
Class: |
F25D 2303/0831 20130101;
F25D 2331/804 20130101; F25D 3/08 20130101; F25D 2303/085
20130101 |
Class at
Publication: |
062/371 ;
062/530 |
International
Class: |
F25D 3/08 20060101
F25D003/08 |
Goverment Interests
GOVERNMENT LICENSE RIGHTS
[0001] This invention was made with Government support under
Cooperative Agreement DE-FC26-98FT40322 awarded by the United
States Department of Energy. The Government has certain rights in
the invention. In particular, funding for this study was provided
by the U.S. Department of Energy, Office of Fossil Energy, National
Energy Technology Laboratory, Morgantown, Va. under Cooperative
Agreement DE-FC26-98FT40322, Task 3.8. The U.S. Government has a
paid-up license in this invention and the right in limited
circumstances to require the patent owner to license others on
reasonable terms as provided for by the terms of Cooperative
Agreement DE-FC26-98FT40322, Task 3.8. awarded by The United States
Department of Energy.
Claims
13. a frozen environmental sample temperature control system as
described in claim 1 wherein said inner surface is pointed.
14. A frozen environmental sample temperature control system as
described in claim 1 wherein said inner surface is holed.
15. A frozen environmental sample temperature control system as
described in claim 1 wherein said inner surface is woven.
16. A frozen environmental sample temperature control system as
described in claim 1 wherein said insulating material has a
thickness greater than that of currently available foam insulating
coolers.
17. A frozen environmental sample temperature control system as
described in claim 16 wherein said insulating material has a
thickness that is at least 10% greater than that of currently
available foam insulating coolers used for cooled environmental
sample shipping.
18. A frozen environmental sample temperature control system as
described in claim 1 wherein said insulating material comprises
polymeric foam.
19. A frozen environmental sample temperature control system as
described in claim 18 wherein said polymeric foam is a foam
selected from the group consisting of a thermosetting foam, a
thermoplastic foam, and a elastomeric foam.
20. A frozen environmental sample temperature control system as
described in claim 1 further comprising an on-board temperature
data logger.
21. A frozen environmental sample temperature control system
comprising: a frozen formulation, itself comprising: water in an
amount from substantially 87% to 78% by weight of said formulation,
and salt in an amount from substantially 13% to 22% by weight of
said formulation; said system further comprising: at least one
container containing said frozen formulation; and a cooler having
insulating material disposed between an outer wall and an inner
surface that defines an inner chamber sized to contain therein said
at least one container and at least one frozen environmental sample
for transport, wherein said insulating material comprises a silica
based insulating material.
22. A frozen environmental sample temperature control system as
described in claim 21 wherein said silica based insulating material
comprises aerogel.
23. A frozen environmental sample temperature control system as
described in claim 21 wherein said inner surface is part of said
insulating material.
24. A frozen environmental sample temperature control system as
described in claim 21 wherein said cooler further comprises an
inner wall that said inner surface is a part of.
25. A frozen environmental sample temperature control system as
described in claim 21 wherein said salt comprises NaCl.
26. A frozen environmental sample temperature control system as
described in claim 25 wherein said salt further comprises a mixture
of NaCl and KCl.
27. A frozen environmental sample temperature control system as
described in claim 21 wherein said salt comprises only one type of
salt.
28. A frozen environmental sample temperature control system as
described in claim 21 wherein said frozen formulation further
comprises a polymeric thickener.
29. A frozen environmental sample temperature control system as
described in claim 21 further comprising an on-board temperature
data logger.
30. A frozen environmental sample temperature control system
comprising: a frozen formulation, itself comprising: water in an
amount from substantially 87% to 78% by weight of said formulation;
and salt in an amount from substantially 13% to 22% by weight of
said formulation; said system further comprising: at least one
container containing said frozen formulation; and a cooler having
insulating material disposed between an outer wall and an inner
surface that defines an inner chamber that is sized to contain said
at least one container and at least one frozen environmental sample
for transport, wherein said insulating material entirely surrounds
said inner surface when said cooler is closed during shipping, and
wherein said insulating material comprises a closed cell polymeric
foam with a foam void volume to total foam volume ratio of greater
than substantially 94%.
31. A frozen environmental sample temperature control system as
described in claim 30 wherein said foam void volume to total foam
volume ratio is greater than substantially 96%.
32. A frozen environmental sample temperature control system as
described in claim 31 wherein said foam void volume to total foam
volume ratio is greater than substantially 97%.
33. A frozen environmental sample temperature control system as
described in claim 30 wherein said closed cell polymeric foam is a
foam selected from the group consisting of a thermosetting foam, a
thermoplastic foam, and an elastomeric foam.
34. A frozen environmental sample temperature control system as
described in claim 30 wherein said closed cell polymeric foam is
selected from the group of foams consisting of: polystyrene foam,
polyurethane foam, ABS foam, ethylene vinyl acetate foam,
polyethylene foam and polypropylene foam.
35. A frozen environmental sample temperature control system as
described in claim 30 wherein closed cells of said closed cell
polymeric foam are selected from the group consisting of air cells,
carbon dioxide cells, CFC vapor cells, nitrogen cells, argon cells,
helium cells, and evacuated cells.
36. A frozen environmental sample temperature control system as
described in claim 30 further comprising an on-board temperature
data logger.
37. A frozen environmental sample temperature control system
comprising: a frozen formulation, itself comprising: water in an
amount from substantially 87% to 78% by weight of said formulation;
and salt in an amount from substantially 13% to 22% by weight of
said formulation; said system further comprising: at least one
container containing said frozen formulation; and a cooler having
insulating material disposed between an outer wall and an inner
surface that defines an inner chamber that is sized to contain said
at least one container and at least one frozen environmental sample
for transport, wherein said insulating material entirely surrounds
said inner surface when said cooler is closed during shipping, and
wherein said insulating material comprises an polymeric network
with evacuated cells.
38. A frozen environmental sample temperature control system as
described in claim 37 wherein said polymeric network has a network
void volume to total network volume ratio of greater than
substantially 94%.
39. A frozen environmental sample temperature control system as
described in claim 37 wherein said polymeric network is selected
from the group consisting of thermoplastic polymeric networks and
thermosetting polymeric networks.
40. A frozen environmental sample temperature control system as
described in claim 37 wherein said polymeric network is selected
from the group consisting of: polystyrene network, polyurethane
network, ABS network, ethylene vinyl acetate network, polyethylene
network and polypropylene network.
41. A frozen environmental sample temperature control system as
described in claim 37 further comprising an on-board temperature
data logger.
42. A frozen environmental sample temperature control system as
described in claim 37 wherein said polymeric network comprises a
network selected from: ribbing, struts, honecomb, and open
cell.
43-66. (canceled)
Description
[0002] This is a United States non-provisional patent application
and claims priority to U.S. Provisional Application No. 60/583,177,
filed Jun. 25, 2004, hereby incorporated herein by reference.7
BACKGROUND OF THE INVENTION
[0003] Materials such as soil samples for volatile organic compound
(VOC) analysis are usually shipped to a testing lab in coolers with
ice packs such that they are kept at refrigerator temperatures near
4 C (+/-2 C). However, both the EPA and ASTM recognize the benefit
of shipping samples at cooler temperatures--freezer (also known as
freezing) temperatures (-7 to -17 C)--for preservation. Known
systems for achieving such temperature control are often
impractical or simply not feasible: shipping samples from the field
in freezer compartments with electronic cooling devices powered by
batteries is not feasible in most cases; shipping in coolers with
dry ice is also not a viable option because air shipment of
packages containing dry ice is regulated (dry ice sublimes to
gaseous carbon dioxide, which can displace air in sealed aircraft).
Also, dry ice has a temperature of -78 C, which is so cold that it
will cause the seals of the sample containers to be compromised,
and VOC's will be lost. Aspects of this inventive technology may
resolve one or more of these problems through the use of a system
that includes cooled packs of an aqueous solution of salt in
combination with a cooler that may be adapted to enhance thermal
insulation of enclosed contents. Some aspects may be directed to a
novel water/salt solution alone.
BRIEF SUMMARY OF INVENTION
[0004] At least one embodiment of the inventive technology relates
to a frozen environmental sample temperature control system that
comprises a frozen formulation (e.g., a solution) having water in
an amount from substantially 87% to 78% by weight of the
formulation, and salt in an amount from substantially 13% to 22% by
weight of the formulation, the system further including at least
one container containing the frozen formulation; and a cooler
having insulating material disposed between an outer wall and an
inner surface that defines an inner chamber into which the at least
one container and the at least one frozen environmental sample may
be placed for storage and/or transport. In various embodiments, the
insulating material may comprise a silica based insulating
material, the inner surface may be configured to reduce conductive
heat transfer to frozen contents of the cooler that are adjacent
the inner surface, the insulating material may comprise a closed
cell polymeric foam with a foam void volume to total foam volume
ratio of greater than substantially 94%, and/or the insulating
material may comprise an polymeric network with evacuated
cells.
BRIEF DESCRIPTION OF DRAWINGS
[0005] FIG. 1a shows a container containing therein an aqueous
solution as in at least one embodiment of the inventive
technology.
[0006] FIG. 1b shows a frozen environmental sample (in a first type
of sample container) whose temperature is to be controlled in at
least one embodiment of the inventive technology.
[0007] FIG. 1c shows a frozen environmental sample (in a second
type of sample container) whose temperature is to be controlled in
at least one embodiment of the inventive technology.
[0008] FIG. 2 shows a cooler that may be used in at least one
embodiment of the inventive technology.
[0009] FIG. 3a shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0010] FIG. 3b shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0011] FIG. 4a shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0012] FIG. 4b shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0013] FIG. 4c shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0014] FIG. 4d shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0015] FIG. 5a shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0016] FIG. 5b shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0017] FIG. 5c shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0018] FIG. 5d shows a cross-sectional view of a portion of a
cooler that may be used in at least one embodiment of the inventive
technology.
[0019] FIG. 6a shows a magnified view of a section of closed-cell
foam used for the insulating material of a cooler used in at least
one embodiment of the inventive technology.
[0020] FIG. 6b shows a magnified view of a section of open-cell
foam used for the insulating material of a cooler used in at least
one embodiment of the inventive technology.
[0021] FIG. 7 shows a cross-sectional view of containers containing
frozen formulation, a sample, and a cooler as found in at least one
embodiment of the inventive technology.
[0022] FIGS. 8a and 8b show plan views of two horizontal
cross-sections of a lower part of a cooler and an upper part of the
cooler, respectively, in at least one embodiment of the inventive
technology.
[0023] FIG. 9 shows a view of a vertical cross-section of a cooler
used in at least one embodiment of the inventive technology.
[0024] FIG. 10 shows cross-sectional views of a portion of a cooler
having polymeric network with evacuated cells as insulating
material.
[0025] FIG. 10a shows a cross-sectional view of a portion of a
cooler having a ribbed polymeric network with evacuated cells as
insulating material.
[0026] FIG. 10b shows cross-sectional top view of a portion of a
cooler having a honeycomb polymeric network with evacuated cells as
insulating material.
[0027] FIG. 10c shows a cross-sectional view of a portion of a
cooler having a strutted polymeric network with evacuated cells as
insulating material.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention includes a variety of aspects, which
may be combined in different ways. The following descriptions are
provided to list elements and describe some of the embodiments of
the present invention. These elements are listed with initial
embodiments, however it should be understood that they may be
combined in any manner and in any number to create additional
embodiments. The variously described examples and preferred
embodiments should not be construed to limit the present invention
to only the explicitly described systems, techniques, and
applications. Further, this description should further be
understood to support and encompass descriptions and claims of all
the various embodiments, systems, techniques, methods, devices, and
applications with any number of the disclosed elements, with each
element alone, and also with any and all various permutations and
combinations of all elements in this or any subsequent
application.
[0029] A wide variety of potential PCL formulations was evaluated
by differential scanning calorimetry (DSC). The optimal PCL
formulation 2 may comprise an aqueous solution of NaCl at a
concentrations of substantially 17 wt.% (where substantially
indicates a tolerance of+/-1.5%); formulations may be without KCl
and/or a thickener (e.g., a polymeric thickener). Other inventive
formulations may include KCl and/or thickener. KCl may be added to
an aqueous solution of NaCl solutions to further depress the
melting point, but at the sometimes unacceptable cost of lowering
the heat of fusion. The formulation can be thickened using, e.g., a
hydrolyzed cellulose (such as CMC) or acrylate water soluble
polymer suitable for thickening the liquid at polymer
concentrations up to 10 wt.%, although a preferred formulation
includes neither thickener nor any salt other than NaCl. In
embodiments that include a cooler, the formulation may have a
concentration ranging from 15-22 wt. % (as but one of many possible
ranges).
[0030] Work was performed to develop a new shipping system for
frozen samples 3 (or other materials) that uses an optimal phase
change liquid (PCL) freezer bag formulation and an insulated
shipping container, perhaps with an on-board digital temperature
data logger to provide a history of the temperature profile within
the container during shipment. At least some of this work is
presented in Exhibit A, hereby incorporated herein by
reference.
[0031] At least one embodiment of the inventive technology may be a
frozen environmental sample temperature control system having a
frozen formulation that may comprise water (e.g., distilled and/or
deionized water) in an amount from substantially 87% to 78% by
weight of the formulation, and salt in an amount from substantially
13% to 22% by weight of the formulation. The system may further
comprise at least one container 1 containing the frozen formulation
and a cooler 4 having insulating material 5 disposed between an
outer wall and an inner surface 6 that defines an inner chamber 7.
The inner chamber may be sized to contain in it the at least one
container and at least one frozen environmental sample for
transport and/or storage. In a preferred embodiment, the insulating
material entirely surrounds the inner surface when the cooler is
closed during shipping. In embodiments where there is only salt and
water in the formulation, it is preferred, but not required, that
the salt be sodium chloride (NaCl), but other salts may indeed be
within the scope of the inventive technology. Also, it should be
noted that in preferred embodiments (but certainly not in all
embodiments), the per-centage amounts of the salt and of water
total 100 per-cent.
[0032] It should be understood that the term temperature control
system is a broad term that refers to at least two types of
systems--a storage system and a shipping system. Of course, where
the temperature control system is intended to control the
temperature of a cooled material such as a frozen environmental
sample, the system is a frozen environmental sample temperature
control system; in broader applications, the system may be a frozen
material temperature control system. As the term frozen refers to a
material (such as an environmental sample) exhibiting temperatures
with the range of from -7--17 degrees C. inclusive (freezing
temperatures), a frozen material temperature control system has as
a goal the maintenance of the material within the freezing
temperature range for a certain period of time. In material
shipping systems, that certain period of time is, in some
embodiments, the expected time from initial packing of the cooler
with the material and the cooled containers of formulation, to the
time of receipt by an intended recipient (e.g., a lab technician),
such as 12 or 14 hours (as but merely two of many examples).
[0033] As to protocol relative to use of the system, typically the
materials whose temperature is to be controlled are pre-cooled,
meaning cooled to below ambient temperature, such as to within the
intended temperature range before the materials are placed into the
cooler with the cooled formulation. However, the inventive
technology also covers use of the cooled formulation and cooler to
bring materials with a temperature above the intended range
(freezing temperatures or refrigerator temperatures, as but two
examples) to within the desired range. It is further pointed out
that although typical protocol does not involve pre-cooling the
cooler (e.g., before materials and cooled formulation is placed
therein), embodiments of the inventive technology may certainly
also include such method. As the reader has likely inferred, the
term cooled may refer simply to material whose temperature has been
reduced to below that value the material would otherwise have
(e.g., if left in ambient temperatures such as room temperature).
Cooled temperatures include freezing temperatures and refrigerator
temperatures, as but two examples of temperature ranges of cooled
materials.
[0034] In certain embodiments of the inventive technology, the
inner surface of the cooler--whether part of the insulating
material or instead part of an inner wall that is distinct from the
insulating material--may be configured to reduce conductive heat
transfer to frozen contents of said cooler that are adjacent said
inner surface. In such embodiments, the inner surface may be
ribbed, pointed (the "point" need not be sharp and can instead be
rounded), holed, or woven, as but a few examples, in order to
reduce conductive heat transfer to contents (e.g., frozen
environmental samples and bags of frozen formulation) by, e.g.,
reducing the surface area of direct contact between the inner
surface of the cooler and contents of the cooler that contact the
inner surface. In certain embodiments of the inventive technology,
the inner surface may be reflective.
[0035] In those embodiments having an inner wall (which, by
definition, is distinct from an inner part of the insulating
material proximate the inner wall) as in FIG. 3b, for example, the
inner wall may be configured so as to have a reduced heat storage
capacity as compared with the heat storage capacity of inner walls
of coolers conventionally used to transport cooled environmental
samples. Such reduction in heat storage capacity may be achieved by
reducing the mass of the inner wall by, e.g., reducing the
thickness of the inner wall, eliminating it, and/or making it from
materials that are less dense (e.g., polymeric foam).
[0036] In certain embodiments, the insulating material may comprise
a silica based insulating material such as aerogel. In certain
embodiments, the insulating material may comprise a closed cell
polymeric foam with a foam void volume to total foam volume ratio
of greater than substantially 94%, greater than substantially 96%,
or greater than substantially 97%; in some embodiments, the closed
cell polymeric foam may comprise a thermosetting foam, a
thermoplastic foam, or an elastomeric foam. Under another system of
classification, the foam may comprise polystyrene foam,
polyurethane foam, ABS foam, ethylene vinyl acetate foam,
polyethylene foam or polypropylene foam. The cells themselves may
encapsulate either a gas (e.g., air, nitrogen, argon, helium) or a
vacuum (i.e., evacuated cells).
[0037] In certain embodiments, the insulating material may comprise
an polymeric network (e.g., foam, struts as in FIG. 10c, ribbing as
in FIG. 10a, honeycomb as in FIG. 10b) with evacuated cells. Where
such cells are open, the vacuum established in the network may
indeed be lost after a certain amount of time, but that amount of
time may be greater than the length of time the insulating effect
of the cooler is needed (e.g., less than 12 hours in the case of
some overnight shipments). The term cell is a broad term, and
certainly not limited to the small cells found typically found in
foams. Indeed, the cells can be large (e.g., as found in strutted,
ribbed, or honeycomb networks). In certain embodiments, the network
void volume to total network volume ratio may be greater than
substantially 94%; in some embodiments, the open cell polymeric
network may comprise a thermoplastic polymeric network (e.g., a
thermoplastic polymeric foam), an elastomeric network (e.g., an
elastomeric foam), or a thermosetting polymeric network (e.g., a
thermosetting foam). Under another system of classification, an
open cell network may comprise polystyrene network (e.g.,
polystyrene foam), polyurethane network (e.g., polyurethane foam),
ABS network (e.g., ABS foam), ethylene vinyl acetate network (e.g.,
ethylene vinyl acetate foam), polyethylene network (e.g.,
polyethylene foam) or polypropylene network (e.g., polypropylene
foam). Related systems may incorporate a pump (e.g., a hand pump or
electric pump) by which to impart a vacuum to the network, where,
as in the case of open celled networks, such vacuum is lost over
time.
[0038] At least one embodiment of the inventive technology may be a
frozen environmental sample temperature control solution that
comprises salt; and liquid water in which the salt is dissolved to
form a formulation, where the formulation has a heat of fusion in
calories per gram that is at least 80% the heat of fusion of water,
a unimodal melting point, and comprises substantially from 15% by
weight of salt to substantially 20% by weight of salt.
[0039] It should be noted that the term salt may be either one or a
plurality of salts. In a preferred embodiment, however, it relates
to one type of salt--NaCl. However, in some embodiments, the system
may include KCl, whether exclusively or in combination with NaCl.
Further, although in a preferred embodiment of the inventive
technology the formulation does not include thickener (e.g., a
polymeric thickener added to facilitate handling of the contained
formulation), certain embodiments may include thickener
(Instathick, as but one example). In a preferred embodiment, the
system includes a salt concentration of substantially 17% by weight
and substantially 83% by weight of the formulation (where
substantially implies a tolerance of +/-11/2%). However, certainly
other ranges are included within the scope of the inventive
technology.
[0040] In certain embodiments of the inventive technology, the
insulating material has a thickness that is greater (e.g., at least
10% greater) than that of currently available foam insulating
coolers used for shipping of refrigerator temperature environment
samples. Of course, the thickness of the insulating material must
be sufficient to keep the temperature of the materials whose
temperature is to be controlled above the highest acceptable
temperature upon their removal from the cooler (given the
constraints of the cooling problem (e.g., the expected external
profile, the initial temperature of the materials whose temperature
is to be controlled, the extent to which the available space in the
cooler other than the materials whose temperature is to be
controlled is filled with cooled formulation, the temperature above
which materials must be upon their removal from the cooler,
etc.)
[0041] It should be noted that in a preferred embodiment, an
aqueous solution of a salt implies the addition of that salt to
salt free water (e.g., water that has no or only de minimus amounts
of salt, such as distilled, deionized water). However, embodiments
of the invention are intended to involve aqueous solutions of a
salt, regardless of whether that salt was added or is naturally
occurring, e.g.). Any manner of dissolution (as but one example,
mechanical) may be used to dissolve the added salt in the water
(e.g., distilled, deionized water).
[0042] At least one embodiment of the invention may relate to the
use of NaCl in aqueous solution (where this solution might not also
have a second added salt in non-negligible amount dissolved
therein) in an amount that maximizes the reduction in melting point
(relative to that melting point that would be observed if there
were no salt dissolved therein). This maximization in reduction of
melting point may be achieved without also causing a bimodal
melting point profile (or without unacceptably diverging peaks of
an existing bimodal melting point profile). At least one embodiment
of the invention may involve the use of NaCl in aqueous solution in
that amount (e.g., 17 wt. % NaCl, or other values as reflected by
the tables filed herewith) that effects a substantial convergence
to a single peak of an otherwise substantially bi-modal melting
point profile. At least one embodiment of the invention maybe the
use of that amount by wt. % of NaCl in aqueous solution that
minimizes the difference between the temperature of melting onset
and the temperature of melting peak.
[0043] It should be understood that embodiments of the inventive
technology may find application not only to the cooling of soil
samples for volatile organic compound (VOC) analysis, but also for
the cooling of any material of which cooling/refrigeration may be
desired or required. Indeed, freezing of the sample is not
mandatory, as it may be that some materials that are to be cooled
using the frozen solution may have a lower freezing point than the
coldest temperature reached by the frozen solution. Cooling is a
broad term and includes generally the reduction of temperature of a
given substance (e.g., a soil sample for VOC analysis) relative to
that temperature that the substance would reach in the absence of
such cooling. Thus, even a sample whose temperature has increased
over a period of time may be cooled.
[0044] In addition to the temperature of fusion, in some
embodiments, the heat of fusion may be an important parameter. The
higher the heat of fusion, the greater the capacity for the
material to store or release energy at the temperature of fusion.
The heat of fusion of water is near 80 cal/g (Bolz and Tuve 1980).
Ideally, a formulation will have as large a heat of fusion as
possible, although embodiments of the inventive technology may
indeed include solutions whose heat of fusion is sub-maximal, but
whose temperature of fusion renders the solution attractive for a
given application. What may also render a formulation attractive
for a certain application may be an enhanced ability to control
temperature of a material due to a formulation's unimodal melting
point profile. A bimodal melting point is deemed to exist where the
melting point profile exhibits more than one zero slope.
[0045] Adding chemicals (including salts) to water can have the
desired effect of lowering the freeze point, but also the undesired
effect of decreasing the heat of fusion. In at least one embodiment
of the invention, the optimal formulation, therefore, will lower
the freeze point to the desired temperature range while maintaining
a heat of fusion as close to that of water as possible. Indeed,
relative to at least one embodiment of the invention, the inventors
contemplate consideration of each the heat of fusion and the
temperature of fusion (and perhaps also the formulation's melting
point temperature profile) in the determination of appropriate
quantities of salt (e.g., NaCl) in aqueous solution.
[0046] At least one embodiment of the inventive technology may
relate to a frozen environmental sample shipping system. It may
incorporate aspects of the formulation and/or the cooler. In
certain embodiments, the cooler may have inner walls whose total
mass is less than that mass of the inner walls of the foam-filled
polyethylene coolers (such as Coleman.TM. coolers and other brands)
that are commonly used for shipping of environmental samples with
water-containing ice bags to maintain them at refrigeration
temperatures (+4.+-.2.degree. C.). Although these coolers perform
adequately for shipping samples at refrigeration temperature, there
is too much heat transfer when frozen materials (at
-12.+-.5.degree. C.) are shipped with the intent of keeping the
temperature of the frozen materials above the upper end of this
range (-7.degree. C.) for a sufficiently long periods of time
(e.g., 12 hours for overnight shipping). Such types of prior art
coolers have not been designed to maintain materials at freezer
temperatures for adequate periods of time. For example, heat can
enter the cooler through the outer polyethylene wall to the inner
polyethythnlene wall by conduction through the polyethylene
material directly (in those conventionally used coolers having gaps
in the insulation). This mechanism is not slowed down by the foam
filling that is found between the inner and outer walls.
[0047] In addition, the polyethylene inner walls of conventionally
used coolers are relatively thick and store a significant amount of
heat. When cooler material is put into a cooler that has been
stored at ambient temperature (the typical practice in shipping
environment samples), heat from the warmer walls is transferred to
the cooler material. This can affect the ability of a frozen phase
change liquid to maintain the contents at freezer temperatures
(-12.+-.5.degree. C.) for an adequate period of time. In some
embodiments, the inner walls may be made of a thinner polyethylene
material with less mass and heat storage capacity than is found in
current designs, or be constructed from other polymeric material to
provide less mass and heat storage capacity, or even other
materials with less total heat storage properties (including but
not limited to: wood, aluminum alloys, and reflective metallized
plastic film). In some embodiments, walls that are less dense (yet
still sufficiently strong for their intended purposes) may
introduce into the cooler less mass that can store heat and
transfer it to the cooled contents upon their initial placement in
the uncooled cooler. The inventors of this technology have
determined that, indeed, one source of the problem associated with
the use of conventional coolers to maintain materials at freezing
temperatures for a certain period of time is the excessively high
heat storage capacity of inner walls of conventional coolers that
are not pre-cooled and that are used to ship cooled materials
(e.g., environmental samples) to arrive within the freezing
temperature range. It should be noted that, although typically
materials are frozen before placement into a cooler, aspects of the
inventive technology also cover the case where the contained frozen
formulation placed in the cooler with the materials whose
temperature is to be controlled is used to cool materials to within
the frozen temperature range.
[0048] In addition to (or instead of) having inner walls that have
a reduced heat storage capacity as compared with existing coolers,
the inner surface walls may be ribbed, pointed, woven (see FIGS. 4d
and 5d), and/or have holes in them, to effect enhanced cooling by
reducing direct contact between the inner walls of the cooler with
the frozen material to decrease the rate of heat transfer from an
un-cooled cooler inner surface to frozen materials that contact
that inner surface (e.g., frozen bags) upon their initial placement
into the "warm" cooler. It should also be noted that the inner
surface so configured may be part of an inner wall (e.g., an inner
cooler wall) that is distinct from the insulating material
(although indeed it may directly contact it), or the inner surface
so configured may be the inner surface of the insulating material
(e.g., in those embodiments where there is no inner wall distinct
from the insulating material).
[0049] Coolers whose inner surfaces are ribbed (e.g., FIGS. 4a and
5a), pointed (e.g., FIGS. 4b and 5b) and/or are "holed" (e.g.,
FIGS. 4c and 5c) can reduce the heat transfer rate to the cooled
contents merely by reducing the direct contact between the cooled
contents and the inner walls of the cooler, even where the
materials used for the inner walls are identical in type and total
mass to those of conventional coolers. It should be noted that an
ideal system may indeed include not only inner walls having inner
surfaces that are configured to reduce conductive heat transfer to
contacting frozen contents (e.g., by being configured to be
pointed, ribbed, woven, or "holed"), but also may have inner walls
that have a reduced mass (as compared with those of conventionally
used polyethylene insulating coolers).
[0050] Of course, externally of the inner chamber and internally of
the exterior walls of the cooler is some type of insulation
material. Such materials include but are not limited to aerogel,
polystyrene foam and polyurethane foam. They include any materials
that have an improved insulating effect as compared with the
current typical configuration of injected polyurethane foam between
the polyethylene walls of conventional coolers, regardless of the
reason for that improved insulating effect (such reasons including:
additional foam thickness, more effective capture of gas or vacuum;
lower density; and/or more structural "deadends" to terminate
conduction in the foam supporting structure, as but three
examples). In one embodiment, as mentioned, the insulating material
may comprise silica aerogel. Such aerogel may or may not be
combined with another material (e.g., carbon black and/or a
reinforcing material such as reinforcing fiber, as but a few
examples).
[0051] In certain embodiments (e.g., those that incorporate the
cooler), the formulation may be from 13%-22% by weight salt in
water (e.g., one salt, such as NaCl), and may or may not include a
thickener (e.g., a polymer). However, the optimal, cooler-based
system may indeed use the preferred embodiment of the formulation
(i.e., one having substantially 83% by weight water (e.g.,
distilled, deionized water) and substantially 17% by weight salt
such as NaCl). Ranges for salt content (e.g., NaCl) of the
formulation in the cooler-based system include but are not limited
to: 13%-22% by weight salt, 14%-21% by weight salt, 15%-20% by
weight salt, and 16%-19% by weight salt. Again, such formulations
may or may not comprise a thickener, although in a preferred
embodiment, the inventive technology does not. Further, they may
include more than one salt (e.g., NaCl and KCl), although in a
preferred embodiment, only one salt (e.g., NaCl) is used.
[0052] Although indeed, in some embodiments, the technology may
achieve enhanced cooling through the combined effect of the cooler
and the formulation, an on-board temperature data logger may be
part of the system and play an important role in tracking the
thermal history of the sample, assessing the representative nature
of the sample, and assessing the need to make changes to the system
(whether to enhance cooling in the case where sample(s) arrived at
a high temperature, or to moderate the cooling effect--thereby
possibly saving costs--in the case where sample(s) arrived at an
unnecessarily low temperature).
[0053] It should be noted that a goal of at least one embodiment of
the inventive technology is to include as part of the system enough
frozen formulation and enough insulating effect that, when
combined, result in a cooler-contained environmental sample(s) that
is delivered at or below a certain temperature to an intended
recipient at or before an estimated time. In those embodiments in
which economy may be an important objective, a goal may be to have
no more than that amount of bags, and no more than that amount of
insulating material that, given other constraints of the
application (e.g., expected ambient heat during travel, expected
time of travel, heat carrying capacity of internal walls of the
cooler), result in a cooling system that does not have more
materials (e.g., formulation and insulating) than is necessary.
[0054] As can be easily understood from the foregoing, the basic
concepts of the present invention may be embodied in a variety of
ways. It involves both cooling techniques as well as devices to
accomplish the appropriate cooling. In this application, the
cooling techniques are disclosed as part of the results shown to be
achieved by the various devices described and as steps which are
inherent to utilization. They are simply the natural result of
utilizing the devices as intended and described. In addition, while
some devices are disclosed, it should be understood that these not
only accomplish certain methods but also can be varied in a number
of ways. Importantly, as to all of the foregoing, all of these
facets should be understood to be encompassed by this
disclosure.
[0055] The discussion included in this application is intended to
serve as a basic description. The reader should be aware that the
specific discussion may not explicitly describe all embodiments
possible; many alternatives are implicit. It also may not fully
explain the generic nature of the invention and may not explicitly
show how each feature or element can actually be representative of
a broader function or of a great variety of alternative or
equivalent elements. Again, these are implicitly included in this
disclosure. Where the invention is described in device-oriented
terminology, each element of the device implicitly performs a
function. Apparatus claims may not only be included for the device
described, but also method or process claims maybe included to
address the functions the invention and each element performs.
Neither the description nor the terminology is intended to limit
the scope of the claims that will be included in any subsequent
patent application.
[0056] It should also be understood that a variety of changes may
be made without departing from the essence of the invention. Such
changes are also implicitly included in the description. They still
fall within the scope of this invention. A broad disclosure
encompassing both the explicit embodiment(s) shown, the great
variety of implicit alternative embodiments, and the broad methods
or processes and the like are encompassed by this disclosure and
may be relied upon when drafting the claims for any subsequent
patent application. It should be understood that such language
changes and broader or more detailed claiming may be accomplished
at a later date (such as by any required deadline) or in the event
the applicant subsequently seeks a patent filing based on this
filing. With this understanding, the reader should be aware that
this disclosure is to be understood to support any subsequently
filed patent application that may seek examination of as broad a
base of claims as deemed within the applicant's right and may be
designed to yield a patent covering numerous aspects of the
invention both independently and as an overall system.
[0057] Further, each of the various elements of the invention and
claims may also be achieved in a variety of manners. Additionally,
when used or implied, an element is to be understood as
encompassing individual as well as plural structures that may or
may not be physically connected. This disclosure should be
understood to encompass each such variation, be it a variation of
an embodiment of any apparatus embodiment, a method or process
embodiment, or even merely a variation of any element of these.
Particularly, it should be understood that as the disclosure
relates to elements of the invention, the words for each element
may be expressed by equivalent apparatus terms or method
terms--even if only the function or result is the same. Such
equivalent, broader, or even more generic terms should be
considered to be encompassed in the description of each element or
action. Such terms can be substituted where desired to make
explicit the implicitly broad coverage to which this invention is
entitled. As but one example, it should be understood that all
actions may be expressed as a means for taking that action or as an
element which causes that action. Similarly, each physical element
disclosed should be understood to encompass a disclosure of the
action which that physical element facilitates. Regarding this last
aspect, as but one example, the disclosure of a "coolant" should be
understood to encompass disclosure of the act of "cooling"--whether
explicitly discussed or not--and, conversely, were there
effectively disclosure of the act of "cooling", such a disclosure
should be understood to encompass disclosure of a "coolant" and
even a "means for cooling" Such changes and alternative terms are
to be understood to be explicitly included in the description.
[0058] Any acts of law, statutes, regulations, or rules mentioned
in this application for patent; or patents, publications, or other
references mentioned in this application for patent are hereby
incorporated by reference. In addition, as to each term used it
should be understood that unless its utilization in this
application is inconsistent with such interpretation, common
dictionary definitions should be understood as incorporated for
each term and all definitions, alternative terms, and synonyms such
as contained in the Random House Webster's Unabridged Dictionary,
second edition are hereby incorporated by reference. Finally, all
references listed in the information disclosure statement or other
information statement filed with the application are hereby
appended and hereby incorporated by reference, however, as to each
of the above, to the extent that such information or statements
incorporated by reference might be considered inconsistent with the
patenting of this/these invention(s) such statements are expressly
not to be considered as made by the applicants. Exhibit A, in
addition to any tables, is also incorporated herein by reference.
Additionally, it should be noted that certain materials (e.g., a
provisional application, which itself incorporates a 2004 report,
and a 2005 report (Exhibit A)) are incorporated herein by
reference. Where incorporated materials are inconsistent with text
of the specification that has not been incorporated (such
non-incorporated text may be considered "directly filed" text), the
non-incorporated text of the specification shall take precedence
over the incorporated text with which it is inconsistent.
[0059] Thus, the applicant(s) should be understood to have support
to claim and make a statement of invention to at least: i) each of
the cooling substances or the cooling apparatus as herein disclosed
and described, ii) the related methods disclosed and described,
iii) similar, equivalent, and even implicit variations of each of
these devices and methods, iv) those alternative designs which
accomplish each of the functions shown as are disclosed and
described, v) those alternative designs and methods which
accomplish each of the functions shown as are implicit to
accomplish that which is disclosed and described, vi) each feature,
component, and step shown as separate and independent inventions,
vii) the applications enhanced by the various systems or components
disclosed, viii) the resulting products produced by such systems or
components, ix) each system, method, and element shown or described
as now applied to any specific field or devices mentioned, x)
methods and apparatuses substantially as described hereinbefore and
with reference to any of the accompanying examples, xi) the various
combinations and permutations of each of the elements disclosed,
and xii) each potentially dependent claim or concept as a
dependency on each and every one of the independent claims or
concepts presented.
[0060] With regard to claims whether now or later presented for
examination, it should be understood that for practical reasons and
so as to avoid great expansion of the examination burden, the
applicant may at any time present only initial claims or perhaps
only initial claims with only initial dependencies. Support should
be understood to exist to the degree required under new matter
laws--including but not limited to European Patent Convention
Article 123(2) and United States Patent Law 35 USC 132 or other
such laws--to permit the addition of any of the various
dependencies or other elements presented under one independent
claim or concept as dependencies or elements under any other
independent claim or concept. In drafting any claims at any time
whether in this application or in any subsequent application, it
should also be understood that the applicant has intended to
capture as full and broad a scope of coverage as legally available.
To the extent that insubstantial substitutes are made, to the
extent that the applicant did not in fact draft any claim so as to
literally encompass any particular embodiment, and to the extent
otherwise applicable, the applicant should not be understood to
have in any way intended to or actually relinquished such coverage
as the applicant simply may not have been able to anticipate all
eventualities; one skilled in the art, should not be reasonably
expected to have drafted a claim that would have literally
encompassed such alternative embodiments.
[0061] Further, if or when used, the use of the transitional phrase
"comprising" is used to maintain the "open-end" claims herein,
according to traditional claim interpretation. Thus, unless the
context requires otherwise, it should be understood that the term
"comprise" or variations such as "comprises" or "comprising", are
intended to imply the inclusion of a stated element or step or
group of elements or steps but not the exclusion of any other
element or step or group of elements or steps. Such terms should be
interpreted in their most expansive form so as to afford the
applicant the broadest coverage legally permissible.
[0062] Finally, any claims set forth at any time are hereby
incorporated by reference as part of this description of the
invention, and the applicant expressly reserves the right to use
all of or a portion of such incorporated content of such claims as
additional description to support any of or all of the claims or
any element or component thereof, and the applicant further
expressly reserves the right to move any portion of or all of the
incorporated content of such claims or any element or component
thereof from the description into the claims or vice-versa as
necessary to define the matter for which protection is sought by
this application or by any subsequent continuation, division, or
continuation-in-part application thereof, or to obtain any benefit
of, reduction in fees pursuant to, or to comply with the patent
laws, rules, or regulations of any country or treaty, and such
content incorporated by reference shall survive during the entire
pendency of this application including any subsequent continuation,
division, or continuation-in-part application thereof or any
reissue or extension thereon.
* * * * *