A vacuum flask (also known as a Dewar flask, Dewar bottle or Thermos) is an insulating storage vessel which keeps its contents hotter or cooler than its surroundings. Invented by Sir James Dewar in 1892, the vacuum flask consists of two flasks, placed one within the other and joined at the neck. The gap between the two flasks is partially evacuated of air, creating a near-vacuum which prevents heat transfer by conduction or convection.
Vacuum flasks are used domestically to keep beverages hot or cold for extended periods of time, and for many purposes in industry.
Read more about Vacuum Flask: History, Design, Domestic Use, Research and Industry, Safety, Security
Famous quotes containing the words vacuum and/or flask:
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—Anne Sexton (1928–1974)
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—Gwendolyn Brooks (b. 1917)