Bunsen burner

Infobox Laboratory equipment
name = Bunsen Burner


caption = A Bunsen Burner with needle valve. The hose barb for the gas tube is facing left and the needle valve for gas flow adjustment is on the opposite side. The air inlet on this particular model is adjusted by rotating the barrel, thus opening or closing the vertical baffles at the base.
acronym =
other_names =
uses = Heating Sterilization Combustion
inventor =
manufacturer =
model =
related = Hot plate Heating mantle
A Bunsen burner is a common piece of laboratory equipment that produces a single open gas flame, which is used for heating, sterilization, and combustion.

History

When the University of Heidelberg hired Robert Bunsen in 1852, the authorities promised to build him a new laboratory building. Heidelberg had just begun to install coal-gas street lighting, so the new laboratory building was also supplied with illuminating gas. Illumination was one thing; a source of heat for chemical operations something quite different. Previous laboratory lamps left much to be desired regarding economy and simplicity, as well as the quality of the flame; for a burner lamp, it was desirable to maximize the temperature and minimize the luminosity. While his building was still under construction late in 1854, Bunsen suggested certain design principles to the university’s talented mechanic, Peter Desaga, and asked him to construct a prototype. The Bunsen/Desaga design succeeded in generating a hot, sootless, non-luminous flame by mixing the gas with air in a controlled fashion before combustion. Desaga created slits for air at the bottom of the cylindrical burner, the flame igniting at the top. By the time the building opened early in 1855, Desaga had made fifty of the burners for Bunsen's students. Bunsen published a description two years later, and many of his colleagues soon adopted the design

Operation

The device in use today safely burns a continuous stream of a flammable gas such as natural gas (which is principally methane) or a liquefied petroleum gas such as propane, butane, or a mixture of both.

The burner has a weighted base with a connector for a gas line (hose barb) and a vertical tube (barrel) rising from it. The hose barb is connected to a gas nozzle on the lab bench with rubber tubing. Most lab benches are equipped with multiple gas nozzles connected to a central gas source, as well as vacuum, nitrogen, and steam nozzles. The gas then flows up through the base through a small hole at the bottom of the barrel and is directed upward. There are open slots in the side of the tube bottom to admit air into the stream via the Venturi effect, and the gas burns at the top of the tube once ignited by a flame or spark. The most common methods of lighting the burner are using a match or a spark lighter.

The amount of air (or rather oxygen) mixed with the gas stream affects the completeness of the combustion reaction. Less air yields an incomplete and thus cooler reaction, while a gas stream well mixed with air provides oxygen in an equimolar amount and thus a complete and hotter reaction. The air flow can be controlled by opening or closing the slot openings at the base of the barrel, similar in function to a car's carburetor.

If the collar at the bottom of the tube is adjusted so more air can mix with the gas before combustion, the flame will burn hotter, appearing blue as a result. If the holes are closed, the gas will only mix with ambient air at the point of combustion, that is, only after it has exited the tube at the top. This reduced mixing produces an incomplete reaction, producing a cooler but brighter yellow which is often called the "safety flame" or "luminous flame". The yellow flame is luminous due to small soot particles in the flame which are heated to incandescence. The yellow flame is considered "dirty" because it leaves a layer of carbon on whatever it is heating. When the burner is regulated to produce a hot, blue flame it can be nearly invisible against some backgrounds. Increasing the amount of fuel gas flow through the tube by opening the needle valve will of course increase the size of the flame. However, unless the airflow is adjusted as well, the flame temperature will decrease because an increased amount of gas is now mixed with the same amount of air, starving the flame of oxygen. The blue flame in a Bunsen burner is hotter than the yellow flame.

ee also

*Heatproof mat

References


*

External links

* [http://dbhs.wvusd.k12.ca.us/webdocs/Electrons/Bunsen-Burner.html An Aside] on the Bunsen Burner.
* [http://thesongoftheday.com/index.cgi?_d=071707 A Song] dedicated to Bunsen Burners.


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Look at other dictionaries:

  • Bunsen burner — Bun sen burn er, Bunsen s burner Bun sen s burn er(Chem.), a kind of burner, invented by Professor Bunsen of Heidelberg, consisting of a straight tube, four or five inches in length, having small holes for the entrance of air at the bottom.… …   The Collaborative International Dictionary of English

  • Bunsen burner — ► NOUN ▪ a small adjustable gas burner used in laboratories. ORIGIN named after the German chemist Robert Bunsen (1811 99) …   English terms dictionary

  • Bunsen burner — [bun′sən] n. [after BUNSEN Robert Wilhelm] a small gas burner that produces a hot, blue flame, used in chemistry laboratories, etc.: it consists of a hollow metal tube with holes at the bottom for admitting air to be mixed with the gas …   English World dictionary

  • Bunsen burner — 1879, named for Prof. Robert Wilhelm Bunsen (1811 1899) of Heidelberg, who invented it in 1855. He also was co inventor of the spectroscope …   Etymology dictionary

  • Bunsen burner — a type of gas burner, commonly used in chemical laboratories, with which a very hot, practically nonluminous flame is obtained by allowing air to enter at the base and mix with the gas. [1865 70; named after R. W. BUNSEN] * * *   device for… …   Universalium

  • Bunsen Burner —    , BUNSENITE    Robert Wilhelm Bunsen (1811 1899) was a professor of chemistry at the University of Heidelberg for thirty seven years. He is credited with having invented the Bunsen burner, but other scientists helped in its design. Together… …   Dictionary of eponyms

  • Bunsen burner — A gas lamp supplied with lateral openings admitting sufficient air so that the carbon is completely burned, thus giving a very hot but only slightly luminous flame. [RW Bunsen, 1811–1899] * * * Bun·sen burn·er bən(t) sən .bər nər n a gas burner… …   Medical dictionary

  • Bunsen burner — UK [ˌbʌns(ə)n ˈbɜː(r)nə(r)] / US [ˈbʌnsən ˌbɜrnər] noun [countable] Word forms Bunsen burner : singular Bunsen burner plural Bunsen burners science a piece of equipment that produces a gas flame, used for scientific experiments in a laboratory …   English dictionary

  • Bunsen burner — Bunzeno degiklis statusas T sritis fizika atitikmenys: angl. Bunsen burner vok. Bunsenbrenner, m rus. бунзеновская горелка, f; горелка Бунзена, f pranc. brûleur Bunsen, m …   Fizikos terminų žodynas

  • Bunsen burner — dujų degiklis statusas T sritis chemija apibrėžtis Laboratorinis įtaisas liepsnai gauti deginant dujas. atitikmenys: angl. Bunsen burner; gas burner rus. газовая горелка ryšiai: sinonimas – Bunzeno degiklis …   Chemijos terminų aiškinamasis žodynas

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