Container having passive controlled temperature interior, and method of construction
View Patent ↗A method and apparatus for shipping articles under controlled temperature conditions, by providing an article enclosure surrounded by a set of hollow walls, and at least partially filling the hollow walls with phase change material, and providing an insulating enclosure about the article enclosure, the insulating enclosure having a relatively high “R” factor for restricting the flow of thermal flux into and out of the article enclosure.
1. An apparatus for shipping an article under controlled temperature conditions, comprising:
(a) a first volume sized for containment of said article, and a first enclosure surrounding said first volume; said first enclosure having a double-walled construction with a second volume sealed between said double walls;
(b) a phase change material at least partially filling said second volume;
(c) at least a partial coating of a non-soluble crystalline material which will promote the formation of ice crystals in the phase change material; and
(d) at least one relief vent into said second volume through one of said double walls, said relief vent having the characteristic of equalizing the air pressure between the second volume and the exterior of said enclosure, and the further characteristic of being impervious to the passage of said phase change material; and
(e) a plurality of insulating walls surrounding said first enclosure, at least one of said plurality of insulating walls being removable to provide access to the interior of said first enclosure.
2. The apparatus of claim 1 , wherein said plurality of insulating walls are arranged to form a cubic second enclosure about said first enclosure.
3. The apparatus of claim 2 , further comprising a third enclosure surrounding said second enclosure, said third enclosure comprising a cardboard shipping carton.
4. The apparatus of claim 1 , wherein said phase change material substantially fills about eighty percent of said second volume.
5. The apparatus of claim 3 , wherein said phase change material further comprises ice.
6. The apparatus of claim 3 , wherein said phase change material further comprises water.
7. The apparatus of claim 3 , wherein said enclosure is made from flexible material having movable side walls.
8. The apparatus of claim 5 wherein said non-soluble crystalline material further comprises aluminum oxide.
9. A container defining a retention chamber for shipping articles contained within the retention chamber under controlled temperature conditions, comprising:
(a) an outer layer of an insulating material having a first uniform thickness except at any corners or edges wherein the thickness of the outer layer is at least as great as the first uniform thickness, and completely surrounding the retention chamber, and
(b) an inner layer of a phase change material retained within a hollow double-walled structure having an interior surface with a coating of a non-soluble crystalline material on at least a portion of the interior surface, the inner layer of phase change material having a second uniform thickness except at any overlapping corners or edges wherein the thickness of the inner layer is at least as great as the second uniform thickness, and completely surrounding the retention chamber.
10. The container of claim 9 wherein the hollow double-walled enclosure includes a pressure relief vent which is permeable to air but impermeable to the phase change material when in a liquid state.