Filtering Funnels
Filtering funnels, also known as Buchner and Hirsch funnels, include a cylinder separated from the funnel with a fritted glass disc or perforated plate. Fritted glass disc funnels are immediately ready for use, while perforated plates call for filter paper moistened with liquid to prevent initial leakage.
Vacuum suction then draws the liquid through the filter and into the cylinder. Porcelain filtering funnels are resistant to acids and alkalis, except for hydrofluoric acid, but should not be used in the filtration of extremely corrosive reagents, which can slowly corrode their protective enamel. The funnels are glazed both outside and inside, except the rim, and are autoclavable.
What Is a Buchner Funnel Used for?
Buchner funnels are used in the laboratory for vacuum-assisted liquid filtering. In organic chemistry, these funnels are used to collect recrystallized compounds because they help remove moisture from the final product.
How Does a Buchner Funnel Work?
Buchner funnels consist of an open straight-sided cylindrical chamber that narrows to a tube- or pipe-shaped opening. The tube-like extension can be placed through a stopper, which is then placed into the top of a filtration or Buchner flask. Plastic versions may have a bung hole located at the side of the chamber to which a vacuum may be attached. Buchner funnels are reusable.
What Types of Buchner Funnels Are There?
The bottom of the Buchner funnel chamber may be perforated or contain a separate fritted disc. Filter paper is used for Buchner funnels with perforated lower surfaces. Place the filter paper of the preferred porosity inside the chamber, pre-wet, add the liquid, and apply the vacuum.
Filtration with a Buchner funnel proceeds more quickly than letting the liquid flow simply using gravity. Most Buchner funnels are also rated for a maximum vacuum pressure.
Thermo Scientific™ Imbuti in polipropilene in due parti Nalgene™ Büchner
Gli imbuti Thermo Scientific™ Nalgene™ Büchner in polipropilene, leggeri e durevoli, sono separabili in due pezzi per agevolarne la pulizia. Questi imbuti non si scheggiano, incrinano o rompono.
Thermo Scientific™ Nalgene™ Reusable Bottle Top Filters
Combina la praticità di un filtro per tappo da flacone con la convenienza di un filtro riutilizzabile. Protezione mediante chiusura a vite di flaconi per terreni in vetro con collo da 33 o 45 mm.
Fisherbrand™ Imbuto filtrante in vetro con disco in vetro sinterizzato
Realizzato in vetro borosilicato e disponibile in diversi formati. L'imbuto filtrante Fisherbrand™ in vetro con dischi in vetro sinterizzato, filtra precipitati del terreno con dimensioni da 16 a 40μ m e pori da 10 a 14μ m, rispettivamente.
Fisherbrand™ Porcelain Buchner Funnels with Fixed Perforated Plates
For suction filtration applications
Imbuto in vetro con gambo corto Pyrex™
In vetro borosilicato Pyrex™ resistente al calore e alle sostanze chimiche. Imbuto di vetro Pyrex™ a stelo corto con angolo a vaschetta da 60°per un adattamento preciso della carta da filtro.
DWK Life Sciences DURAN™ Filter Funnel
Filter funnels are filters that are used for solid-liquid separation by means of vacuum.
Kartell™ Imbuto analitico in polipropilene
In polipropilene per garantire resistenza e durata. Gli imbuti analitici in propilene Kartell™ sono progettati in particolare per la chimica analitica.
Quickfit™ Borosilicate Glass Büchner Vacuum Filtration Funnels with Glass Sintered Disc
Useful where conventional filter papers would be destroyed by acids and alkalis
Haldenwanger™ Imbuto Buchner in porcellana
In porcellana smaltata per fornire un'eccellente resistenza chimica e termica. Gli imbuti Buchner in porcellana Haldenwanger™ sono ideali per la filtrazione rapida.
Haldenwanger™ Imbuto Buchner in porcellana
Use these funnels for a variety of filtration applications. Haldenwanger™ Porcelain Buchner Funnels are constructed from optimized laboratory porcelain.
Robu™ Büchner Filter Funnels with Porosity 4 VitraPOR™ Glass Filter Discs
Robu™ Büchner Filter Funnels with Glass Filter Discs are made of pure borosilicate 3.3 glass and are highly resistant to most chemicals, including solvents, acids, and alkalis. The VitraPOR™ filter disc is rated as Porosity 5 (Pore size: 1 to 1.6 μm, Standard: ISO 4793-80).
Robu™ Büchner Filter Funnels with Porosity 2 VitraPOR™ Glass Filter Discs
Robu™ Büchner Filter Funnels with Glass Filter Discs are made of pure borosilicate 3.3 glass and are highly resistant to most chemicals, including solvents, acids, and alkalis. The VitraPOR™ filter disc is rated as Porosity 2 (Pore size: 40 to 100 μm, Standard: ISO 4793-80).
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Cytiva Life Sciences™ GAM MicroFunnel Filter Funnels
Convenient, ready-to-use disposable filter funnels for quality control analysis of aqueous fluids used in pharmaceutical production, water, and food and beverage applications.
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Cytiva Life Sciences™ MicroCheck II Beverage Monitor
Easy to use, versatile, disposable filter funnels for microbial analysis.