Büchner funnel

Büchner funnel

Infobox Laboratory equipment
name = Büchner funnel


caption = A Büchner funnel connected to a flask with a tube leading to a vacuum pump
acronym =
other_names =
uses = Filtration
inventor = Ernst Büchner
manufacturer =
model =
related = Hirsch funnel Dropping funnel Separatory funnel
A Büchner funnel is a piece of laboratory equipment used in suction filtration. [cite journal |url=http://jchemed.chem.wisc.edu/hs/Journal/Issues/2006/Sep/clicSubscriber/V83N09/p1283.pdf |format=PDF |title=The Origins of the Hirsch and Büchner Vacuum Filtration Funnels |journal= Journal of Chemical Education |volume=83 |issue=9 |date=September 2006 |pages=1283 |last=Jensen |first=William B.] It is traditionally made of porcelain, but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a perforated plate separating it from the funnel. The Hirsch funnel has a similar design; it is used similarly, but for smaller quantities of material. The main difference is that the plate is much smaller, while the walls of the funnel angle outward instead of being vertical.

The filtration material, usually filter paper, is placed on the plate, and the filter paper is moistened with a solvent to prevent initial leakage. The liquid to be filtered is poured into the cylinder and drawn through the perforated plate by vacuum suction.

The main advantage in using this type of filtration is that it proceeds much more quickly (several orders of magnitude) than simply allowing the solvent to drain through the filter medium via the force of gravity. It is essential that the amount of solvent being used be limited to less than what would overflow the flask, otherwise the solvent will be drawn into the vacuum equipment. If the vacuum is provided by a water flow device, an overflow of the solvent could result in the spilling of a hazardous solvent into the wastewater stream, a potential violation of the law, depending on the solvent. The potential for overflow and the potential for water to be drawn back into the flask can be reduced by using a trap between the flask and the vacuum source.

It is used in organic chemistry labs to assist in collecting recrystallized compounds. The suction allows the wet recrystallized compound to dry out such that the pure dried crystal compound is left remaining. Although, it is often the case that further drying is required, by an oven or other means, in order to remove as much residual solvent as possible.

It is often used in combination with a Büchner flask.

It is commonly thought to be named for the Nobel Laureate, Eduard Buchner, but it is actually named for the industrial chemist Ernst Büchner.

References


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Look at other dictionaries:

  • Büchner funnel — Biuchnerio piltuvas statusas T sritis chemija apibrėžtis Akytas porcelianinis piltuvas vakuuminiam filtravimui. atitikmenys: angl. Büchner filter; Büchner funnel rus. воронка Бюхнера …   Chemijos terminų aiškinamasis žodynas

  • Buchner funnel — Büch·ner funnel bu̇k nər n a cylindrical often porcelain filtering funnel that has a perforated plate on which the filter paper is placed and that is used usu. with a vacuum Büch·ner buek nər Ernst German chemist. Büchner introduced his funnel in …   Medical dictionary

  • büchner funnel — ˈbu̇knə(r), ˈbueḵn noun Usage: usually capitalized B Etymology: after Ernst Büchner fl1888 German chemist, its inventor : a cylindrical often porcelain filtering funnel that has a perforated plate on which the filter paper is placed and that is… …   Useful english dictionary

  • Buchner funnel — A funnel with an interior perforated plate on which filter paper is placed that functions in vacuum filtration …   Dictionary of invertebrate zoology

  • Büchner — (or Buchner) is a German language surname related to the word Buch ( de. book) and may refer to: * Eduard Buchner (1860–1917), German chemist and zymologist * Ernst Büchner, German chemist * Georg Büchner (1813 1837), German writer * Joachim… …   Wikipedia

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  • funnel — 1. A hollow conical vessel with a tube of variable length proceeding from its apex, used in pouring fluids from one container to another, in filtering, etc. 2. In anatomy, an infundibulum. Büchner f. a porcelain f. that contains a perforated …   Medical dictionary

  • Büchner filter — Biuchnerio piltuvas statusas T sritis chemija apibrėžtis Akytas porcelianinis piltuvas vakuuminiam filtravimui. atitikmenys: angl. Büchner filter; Büchner funnel rus. воронка Бюхнера …   Chemijos terminų aiškinamasis žodynas

  • Büchner — Eduard, German chemist and Nobel laureate, 1860–1917. See B. extract, B. funnel. Hans E.A., German bacteriologist, 1850–1902. See B. extract …   Medical dictionary

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