 Sketch from U.S. patent application A vacuum flask is a vessel which keeps its contents hotter or cooler than their environment by interposing an evacuated region to provide thermal insulation between the contents and the environment. Note that the vacuum is used for thermal insulation; the contents are not in vacuum conditions. Image File history File links Download high-resolution version (1626x2652, 76 KB) Page from a U.S. patent application. ...
Image File history File links Download high-resolution version (1626x2652, 76 KB) Page from a U.S. patent application. ...
Image File history File linksMetadata Download high resolution version (1040x1983, 476 KB) File links The following pages link to this file: Nitrogen Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ...
Image File history File linksMetadata Download high resolution version (1040x1983, 476 KB) File links The following pages link to this file: Nitrogen Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ...
The 630 foot high, stainless-clad (type 304) Gateway Arch defines St. ...
General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...
Cryopreservation of plant shoots. ...
Vessel can refer to any of the following: Objects Vessel (French vaissel, from a rare Latin vascellum, diminuitive of vas, vase, or urn), a word of somewhat wide application for many objects, the meaning common to them being capacity to hold or contain something. ...
The term Thermal Insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer. ...
The vacuum flask was invented by physicist and chemist James Dewar in 1892. A practical vacuum flask is a bottle made of glass, metal, or plastic with hollow walls; the narrow region between the inner and outer wall is evacuated of air. It can also be considered to be two thin-walled bottles nested one inside the other, and sealed together at their necks. The vacuum flask is also known as a Dewar flask after its inventor. Physicists working in a government lab A physicist is a scientist who studies or practices physics. ...
A chemist pours from a Florence flask. ...
Sir James Dewar (September 20, 1842 – March 27, 1923) was a Scottish chemist and physicist. ...
1892 (MDCCCXCII) was a leap year starting on Friday (see link for calendar). ...
Glass can be made transparent and flat, or into other shapes and colors as shown in this sphere from the Verrerie of Brehat in Brittany. ...
Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms positive ions (cations) and has metallic bonds. ...
Household items made out of plastic. ...
Layers of Atmosphere (NOAA) Air redirects here. ...
Theory of operation
A vacuum does not conduct heat by conduction or convection, but only by radiation. Radiative heat loss can be minimized by applying a reflective coating to surfaces: Dewar used silver. Heat flow along perfectly insulated wire Heat conduction is the transmission of heat across matter. ...
Convection is the internal movement of currents within fluids (i. ...
Thermal radiation is electromagnetic radiation emitted from the surface of an object which is due to the objects temperature. ...
General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...
The contents of the flask reach thermal equilibrium with the inner wall; the wall is thin, with low thermal capacity, so does not exchange much heat with the contents, affecting their temperature little. At the temperatures for which vacuum flasks are used (usually below the boiling point of water), and with the use of reflective coatings, there is little radiative (infrared) transfer. Heat capacity (abbreviated Cth or just C, also called thermal capacity) is the ability of matter to store heat. ...
The flask must in practice have an opening for contents to be added and removed; as a vacuum cannot be maintained at the opening, a stopper made of thermally insulating material must be used, originally cork, later plastics. Most heat loss takes place through the stopper. A cork stopper for a wine bottle Champagne corks Varnished cork tiles can be used for flooring, as a substitute for linoleum or tiles. ...
The term plastics covers a range of synthetic or semi-synthetic organic condensation or polymerization products that can be molded or extruded into objects or films or fibers. ...
Purpose and uses Vacuum flasks are used to maintain their contents, often but not always liquid, at a temperature higher or lower than ambient temperature. A liquid will usually assume the shape of its container. ...
To meet Wikipedias quality standards, this article may require cleanup. ...
Domestic and food industry use They are often used to keep food and drink either cold or hot. A typical domestic vacuum flask, usually referred to generically by the name of the first company to produce them commercially, Thermos, will keep liquid cool for about 8 hours, and warm for 24.
Laboratory and industrial use Vacuum flasks are often used to store liquids which become gaseous at well below ambient temperature, e.g., oxygen, nitrogen, etc.; in this case, the leakage of heat into the extremely cold interior of the bottle results in a slow "boiling-off" of the liquid so that a narrow unstoppered opening, or a stoppered opening protected by a pressure relief valve, is necessary to prevent pressure from building up and shattering the flask. The excellent insulation of the Dewar flask results in a very slow "boil" and thus the contents remain liquid for a long time without the need for expensive refrigeration equipment. General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...
General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...
Relief Valve A relief valve opens to release excess pressure when the pressure is too high to protect the vessel or other equipment from overpressurization. ...
The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ...
It has been suggested that Refrigerator be merged into this article or section. ...
History The first vacuum flasks for commercial use were made in 1904 when a German company, Thermos GmbH, was formed. "Thermos", their tradename for their flasks, remains a registered trademark in some countries but was declared a genericized trademark in the US in 1963 as it is colloquially synonymous with vacuum flasks in general—in fact it is far more common to speak of a domestic thermos than a vacuum flask. LunchBox Made by American Thermos Products Company Hand lettered in yellow paint, OFF LIMITS HARRY S. TRUMAN. Metal, plastic. ...
LunchBox Made by American Thermos Products Company Hand lettered in yellow paint, OFF LIMITS HARRY S. TRUMAN. Metal, plastic. ...
Categories: Stub ...
Harry S. Truman (May 8, 1884–December 26, 1972) was the thirty-third President of the United States (1945–1953); as Vice President, he succeeded to the office upon the death of Franklin D. Roosevelt. ...
1904 (MCMIV) was a leap year starting on a Friday (link will take you to calendar). ...
A thermos is a Vacuum flask ; Thermos is an ancient greek city, the capital city of the Aetolian League. ...
A genericized trademark (Commonwealth English genericised trade mark), sometimes known as a generic trade mark, generic descriptor or proprietary eponym, is a trademark or brand name which is often used as the colloquial description for a particular type of product or service as a result of widespread popular or cultural...
See also Cryogenics is a branch of physics (or engineering) that studies the production of very low temperatures (below –150 °C, –238 °F or 123 K) and the behavior of materials at those temperatures. ...
Dewar tubes are constructed like Dewar flasks, but unsilvered and open at both ends, to allow a heat transfer fluid to flow through and absorb sunlight. ...
Vacuum flask cooking is an invention introduced to the Asian market in the mid 1990s. ...
External links - Burger, R., U.S. Patent 872795, "Double walled vessel with a space for a vacuum between the walls", December 3, 1907.
- Thermos LLC Major manufacturer of Vacuum flasks for consumers
- Stanley Major manufacturer of Vacuum flasks for consumers
- The Gourmet Kitchen Major retailer of Vacuum flasks for consumers
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