| 摘要 |
The parallelepiped-shaped container has double-skinned walls and close-fitting lid forming a plastic- e.g. polyurethane-foam-filled sandwich. Items, typically of food and drink, placed inside, are kept cold by deep-frozen blocks (6) - typically sealed plastic bottles containing water or a eutectic mixture, previously frozen and reduced in temperature to e.g. -15 deg. C. Two such blocks are placed in open brackets (8) directly exposed to the contents, and two or more in reserve in a side-box (9) with higher thermal resistivity than the main box. After e.g. 20 hours, the latter are still about 80 % effective, while the others may be considered exhausted. Interchanging the two pairs extends the useful cool period for about 16 hours more.
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