Filtering Funnels
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.
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.
Rogo-Sampaic Imbuto Buchner in porcellana
Excellent for separating liquids from solids in the laboratory. Porcelain Buchner Funnels provide a quick and easy pressure assisted filtration method.
Haldenwanger™ Imbuto Buchner in porcellana
Use these funnels for a variety of filtration applications. Haldenwanger™ Porcelain Buchner Funnels are constructed from optimized laboratory porcelain.
Fisherbrand™ Porcelain Buchner Funnels with Fixed Perforated Plates
For suction filtration applications
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.
DWK Life Sciences DURAN™ Filter Funnel
Filter funnels are filters that are used for solid-liquid separation by means of vacuum.
Quickfit™ Borosilicate Glass Büchner Vacuum Filtration Funnels with Glass Sintered Disc
Useful where conventional filter papers would be destroyed by acids and alkalis
Haldenwanger™ Porcelain Buchner Funnel
An excellent and durable choice for the handling of materials in the laboratory.
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.
Imbuto filtrante Buchner in vetro Pyrex™, diametro 120 mm
Manufactured from chemically resistant Pyrex™ glass. Pyrex™ 120mm Diameter Glass Büchner Filter Funnel with integral sintered glass disc is highly resistant to most corrosive reagents and eliminates the need for filter papers.
Bel-Art™ Imbuti Büchner SP Scienceware™
Leggeri, ma non sbilanciati.
Lenz Laborglasinstrumente™ Borosilicate Glass Filter Funnels
Lenz Laborglasinstrumente™ Filter funnels are ideal for separating solids from liquids via laboratory filtration.
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.
Bel-Art™ Imbuti Buchner, singolo pezzo, SP Scienceware™
In HPDE monopezzo con piastra filtrante porosa sigillata in polietilene Fritware™