| Büchner funnel | |
 A Büchner funnel connected to a flask with a tube leading to a vacuum pump
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| Uses | Filtration |
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| Inventor | Ernst Büchner |
| Related items | Hirsch funnel Dropping funnel Separatory funnel |
A Büchner funnel is a piece of laboratory equipment used in suction filtration. A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial Vacuum. Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases by interposing a medium to fluid flow through which the fluid A Büchner funnel is a piece of Laboratory equipment used in Suction filtration. A dropping funnel is a type of Laboratory glassware used to transfer fluids A separating funnel, also known as separation funnel, separatory funnel, or colloquially sep funnel, is a laboratory glassware used in Liquid-liquid A laboratory (informally lab) is a facility that provides controlled conditions in which scientific Research, Experiments and Suction Filtration is a method of filtration which allows for a greater rate of filtration [1] It is traditionally made of porcelain, but glass and plastic funnels are also available. Porcelain is a Ceramic material made by heating raw materials generally including Clay in the form of Kaolin, in a Kiln to temperatures Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products 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. Filter paper is a semi-permeable Paper barrier placed Perpendicular to a liquid flow The liquid to be filtered is poured into the cylinder and drawn through the perforated plate by vacuum suction. Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner.
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. A Büchner flask, also known as a vacuum flask, filter flask side-arm flask or Kitasato flask, is a thick-walled Erlenmeyer flask with a short glass
It is commonly thought to be named for the Nobel Laureate, Eduard Buchner, but it is actually named for the industrial chemist Ernst Büchner. Eduard Buchner (May 20 1860 &ndash August 13 1917 was a German chemist and zymologist, the winner of the 1907 Nobel Prize in Chemistry
References
- ^ Jensen, William B. (September 2006). "The Origins of the Hirsch and Büchner Vacuum Filtration Funnels" (PDF). Journal of Chemical Education 83 (9): 1283. The Journal of Chemical Education ( JCE) is a monthly subscription-only periodical available in both print and electronic versions