Patent Application
20140138392
The present disclosure relates generally to storage containers and methods of storing temperature sensitive items.
Certain pharmaceutical products and many biological materials are temperature sensitive, in that freezing may damage the materials, and temperatures that are too high may otherwise spoil the materials. Thus, during shipment and storage of these types of materials, they must often be maintained within a particular temperature range. One common range for such materials during shipment and/or storage is 2-8° C. With materials that are not damaged by freezing, it may be desirable to freeze the materials for storage and/or during shipment. In such cases, dry ice may be used in the storage area of a storage container to provide a storage temperature around the phase change temperature of dry ice, which is −78.5° C. Such storage containers may be active or passive. For example, a refrigerator or freezer is an active storage container and typically includes a refrigeration unit to extract heat from inside the storage container to maintain the desired storage temperature. A styrofoam cooler is an example of a passive storage container that relies on thermally insulating materials to retard heat transfer through the container walls. Passive storage containers are sometimes used with ice, dry ice, or some other type of phase change material inside the container to the maintain the storage area temperature.
In accordance with one or more embodiments, a thermal storage system includes a thermally insulated storage container comprising one or more walls that together at least partially define a storage area. The thermal storage system also includes a contents rack that includes a contents sleeve shaped to have a close fit with a contents container. The contents rack is configured to interact with at least one of the container walls to help stabilize the contents container in a desired position within the storage area.
In accordance with one or more embodiments, a thermal storage system includes a thermally insulated storage container comprising one or more walls that together at least partially define a storage area. The thermal storage system also includes a contents container sized to fit within the storage area, and a metallic contents stabilizer configured to form a thermally conductive path between the contents container and phase change material located in the storage area away from the contents container.
In accordance with one or more embodiments, a contents rack for use in a thermally insulated storage container includes a contents sleeve shaped to have a close fit with a contents container, and a stabilizer extending from the contents sleeve to secure the contents sleeve in a desired position within a storage area of the storage container.
One or more preferred exemplary embodiments of the invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and wherein:
In applications where it is desirable to maintain the temperature of stored contents at the phase change temperature of a phase change material in the storage area of a storage container, physical contact between the stored contents and the phase change material may be desirable to provide a conduction path between the contents and the phase change material. For example, where it is desirable to maintain the stored contents at 0° C., the phase change temperature of wet ice (i.e., frozen water), it may be useful to have the stored contents in physical contact with the ice, as opposed to being in some other part of the storage container where convection is relied upon to maintain the contents at the phase change temperature. With dry ice, the stored contents are best maintained at −78.5° C. through physical contact with the dry ice.
When the contents are initially placed into a storage container, this may be easily accomplished by at least partially burying the contents directly in the phase change material, with the phase change material in crushed, granulated, pelletized, chipped, or chunk form (e.g., ice cubes or dry ice pellets). During storage, however, the phase change material may change from solid form to liquid or gas form and allow the contents to shift. In some cases, physical contact between the contents and the phase change material can be lost. This may particularly be the case with subliming phase change materials, such as dry ice, when the material is packaged around the contents to initially support the contents inside the storage container in a particular location and/or orientation.
A storage container with a contents rack as described below can help with temperature stability in applications where it is desirable to maintain the temperature of stored contents at the phase change temperature of the phase change material in the storage area of the container. The contents rack can be configured to maintain the original position and/or orientation of the stored contents during storage, regardless of how much of the phase change material remains in solid form, and it can help ensure a conduction path between the remaining solid or liquid phase change material and the contents.
With reference to
The illustrated storage container 12 includes a plurality of walls 20 that together define a storage area 22 when closed. Each wall 20 may be made from or may include an insulating or super-insulating material, such as expanded polystyrene (EPS), polyurethane, aerogel, etc. The storage container may 12 be configured to hold one or more contents racks 14 and/or contents containers 16 along with ice packs, heat packs, loose phase change material, or other material designed to stabilize or otherwise affect the temperature of the storage area 22. The storage container 12 may be active or passive. An active version of the storage container includes a heating/cooling unit 24 which may include known components and arrangements of components. When unit 24 is omitted, the storage container 12 is a passive storage container.
The contents rack 14 includes a contents sleeve 26 that is shaped to have a close fit with the contents container 16. The contents container 16 fits inside and makes contact with surrounding walls 28 of the sleeve 26. Preferably the contact between the sleeve 26 and the contents container 16 is surface contact. In one embodiment, a thin liner, such as a thin plastic film, separate liner, or bag (not shown) may be placed between the contents container 16 and the contents sleeve 26 to assist with subsequent removal of the contents container from the contents sleeve. In the illustrated embodiment, the contents sleeve 26 is shaped to surround or circumscribe the contents container 16, but could also be shaped to only partially circumscribe the contents container. The contents rack 14 is configured to interact with at least one of the container walls 20 to help stabilize the contents container 16 in a desired position within the storage area 22 of the storage container 12. The desired position may include a particular location within the storage area and/or a desired orientation. In this example, the contents rack 14 includes contents stabilizers 30 to help stabilize the contents container in the desired position when placed in the storage container 12 together with sleeve 26. Each stabilizer 30 extends from the contents sleeve 26 to contact or otherwise interact with one or more of the walls 20. The interaction can include physical contact, a tongue-in-groove fit, and/or a temporary or permanent attachment, for example.
Turning to
The stabilizers 30 space the contents sleeve 26, and thus the contents container 16, away from the wall(s) 20 of the storage container 12 at a fixed location. In this example, the stabilizers 30 extend between the contents sleeve 26 and corners of the storage container 12, formed at the intersection of vertical walls 20 of the storage container. The sleeve 26 and stabilizers 30 can be formed and/or assembled as a single unit for removable placement inside the storage area 22 of the container 12. Or the sleeve 26 and the stabilizers 30 can be constructed as separate pieces for individual placement inside the storage area 22. For example, the sleeve 26 may be selected to fit the particular contents container 16 to be stored, and the stabilizers 30 may be separately selected to fit between the sleeve and the walls 20 of the particular storage container 12 to be used.
Selecting from different sizes of stabilizers 30 depending on the size of the storage area 22 is one way of making the stabilizers 30 adjustable. The stabilizers 30 may be made adjustable to fit a given storage area 22 in other manners as well. For example, the stabilizers 30 may be formed from sufficiently foldable or flexible materials that can be bent to fit a given storage area. Or the stabilizers 30 may include sliding or telescoping components. The illustrated stabilizers 30 are in the form of fins that generally extend along the full length of the sleeve 26 (in the vertical direction of
The contents stabilizers 30 may additionally function as thermal stabilizers. For example, the stabilizers 30 can be constructed from or comprise a metallic material or some other sufficiently thermally conductive material and arranged to form a thermally conductive path between the contents container and phase change material 32 located in the storage area 22 away from the contents container 16. In other words, phase change material 32 such as crushed ice or dry ice that would otherwise not be contacting the contents container 16 or the contents sleeve 26 is placed in conductive thermal communication with the contents container by the conductive stabilizers 30. Thus, as depicted in the cross-sectional views of
In the above-described manner, the contents rack 14 can both maintain the desired position of the contents container 16 during storage and/or shipment and maintain a conductive thermal path between shifting phase change material 32 and the contents container 16. This can help prevent the stored contents from being subjected to a “floating” phenomenon, especially during shipping, where the storage container 12 may be moved and jostled in multiple directions as it traverses conveyor belts, travels over rough roads, and is manually tossed or thrown by shipping personnel from one location to another. The contents rack can be configured to keep the remaining solid phase change material evenly distributed around the stored contents and in conductive thermal communication with the stored contents, even as the storage container is tossed and turned. Studies have indicated that a typical package in-transit will be rotated 21 times per day. Studies have also indicated that stored contents that have “floated” to the top of a bed of dry ice inside an insulated storage container (in the absence of the contents rack described herein) will warm to temperatures ranging from −20° C. to −30° C.—i.e., about 50° C. or more away from the actual dry ice temperature. Some frozen biomaterials may be critically damaged if they reach such temperatures as a result of floating.
Experiments with an embodiment of the above-described thermal storage system, including a contents rack with stabilizers, have demonstrated that the stored contents can be successfully maintained at the dry ice phase change temperature, even with only 20% of the open storage area filled with dry ice. In comparison, stored contents packed in the same insulated storage container in the absence of the contents rack can reach temperatures of −30° C. or higher when 20% of the open storage area is packed with dry ice.
In another embodiment, shown in
In another embodiment, shown in
Other variations are possible. For example, the ends of the contents sleeve may be closed-off during storage, the contents rack may include multiple contents sleeves, or the ends of the contents sleeve may be oriented vertically rather than horizontally. In addition, while described in the context of maintaining stored contents at typical cold storage temperatures (0° C. for wet ice or −78.5° C. for dry ice), these teachings are applicable to storage at any temperature. For example, a liquid or molten phase change material could be used to keep stored contents warmer than the external environment, eventually solidifying as is cools. The above-described contents rack could function to maintain a conductive path in such cases, even with the storage area only partially filled.
It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.
As used in this specification and claims, the terms “for example,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.
This application claims the benefit of U.S. Provisional Application No. 61/727,471, filed Nov. 16, 2012, the entire contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61727471 | Nov 2012 | US |
