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.
- (1)
- (3)
- (166)
- (107)
- (2)
- (5)
- (6)
- (1)
- (1)
- (2)
- (5)
- (6)
- (4)
- (1)
- (2)
- (2)
- (9)
- (1)
- (1)
- (40)
- (23)
- (21)
- (2)
- (6)
- (6)
- (5)
- (1)
- (1)
- (2)
- (1)
- (38)
- (19)
- (31)
- (2)
- (3)
- (1)
- (1)
- (7)
- (4)
- (1)
- (1)
- (11)
- (1)
- (6)
- (1)
- (2)
- (1)
- (11)
- (16)
- (1)
- (3)
- (1)
- (1)
- (10)
- (21)
- (1)
- (1)
- (7)
- (1)
- (1)
- (1)
- (3)
- (6)
- (2)
- (2)
- (11)
- (1)
- (3)
- (11)
- (40)
- (35)
- (1)
- (1)
- (2)
- (2)
- (1)
- (1)
- (1)
- (2)
- (18)
- (1)
- (1)
- (7)
- (5)
- (2)
- (1)
- (1)
- (1)
- (1)
- (80)
- (4)
- (3)
- (1)
- (31)
- (1)
- (11)
- (26)
- (1)
- (3)
- (23)
- (1)
- (3)
- (9)
- (5)
- (1)
- (4)
- (6)
- (4)
- (1)
- (7)
- (12)
- (2)
- (9)
- (3)
- (3)
- (5)
- (1)
- (1)
- (1)
- (2)
- (3)
- (1)
- (3)
- (2)
- (1)
- (12)
- (4)
- (1)
- (1)
- (4)
- (1)
- (3)
- (1)
- (1)
- (10)
- (1)
- (2)
- (1)
- (1)
- (1)
- (6)
- (1)
- (6)
- (1)
- (1)
- (1)
- (2)
- (3)
- (1)
- (1)
- (4)
- (1)
- (3)
- (1)
- (1)
- (1)
- (1)
- (1)
- (1)
- (2)
- (1)
- (6)
- (1)
- (1)
- (2)
- (1)
- (2)
- (4)
- (1)
- (1)
- (4)
- (4)
- (3)
- (1)
- (2)
- (4)
- (4)
- (2)
- (1)
- (2)
- (3)
- (1)
- (2)
- (5)
- (3)
- (7)
- (1)
- (3)
- (1)
- (4)
- (1)
- (1)
- (2)
- (1)
- (1)
- (2)
- (6)
- (7)
- (1)
- (2)
- (3)
- (9)

Sartorius™ Glass Funnels
Use with glass vacuum filter holder assemblies. Sartorius™ Glass Funnels are made of high-quality borosilicate glass. Available in 30, 250 and 400mL capacities.
Product Type | Glass Funnel |
---|---|
Material | Borosilicate Glass |
For Use With (Application) | Filtration with glass vacuum filter holder assemblies |
Lenz Laborglasinstrumente™ Borosilicate Glass Filter Funnels
Lenz Laborglasinstrumente™ Filter funnels are ideal for separating solids from liquids via laboratory filtration.
Product Type | Filter Funnel |
---|---|
Material | Borosilicate Glass |
DWK Life Sciences Funnel with Scale for DURAN™ Filtering Apparatus, Funnel Only
The filter unit can be used with an appropriate filter for particle analysis or clear and sterile filtration. Filtration support by vacuum is possible.
Bel-Art™ Scienceware™ PMP Urbanti High-speed Filter Paper
Unsurpassed for non-vacuum, high-speed filtration
Quickfit Pyrex™ Cylindrical Funnel with Semi-Micro Sintered Glass Disc
Ideal for filtering semi-micro quantities of material
Lenz Laborglasintrumente Micro Filter Funnels
Made of high quality materials. Each manufacturing step is tested through an extensive quality management system, based on DIN ISO 9001/EN 29001.
Capacity (Metric) | 2 mL |
---|---|
Material | Borosilicate Glass (3.3) |
DWK Life Sciences DURAN™ Filter Funnel, conical shape
The filter funnel has a melted filter plate and is used for filtration without vacuum. When using the filter funnel, a filter paper can be dispensed with.
Diameter (Metric)Top | 55 mm |
---|---|
Capacity (Metric) | 25 mL |
Quantity | 1 Ea. |
Material | Borosilicate Glass (3.3) |
For Use With (Application) | Filtering of liquids; Filtration without filter paper; The spillage of substances is avoided; Filtering |
Autoclavable | Autoclavable |
Height (Metric) | 330 mm |
---|---|
Diameter (Metric)Top | 61 cm |
Product Type | Buchner Funnel |
Capacity (Metric) | 74 L |
Material | Polyethylene |
Bel-Art™ Buchner Table-Top Funnels
Table-Top Funnel constructed of polyethylene is designed to filter large volumes quickly.
Diameter (English)Top | 10.25 in. |
---|---|
Height (Metric) | 12.7 cm |
Diameter (Metric)Top | 26 cm |
Product Type | Buchner Funnel |
Capacity (Metric) | 6.75 L |
Quantity | 1/Pk, 1/Cs |
Material | HDPE,Polyethylene |
Length (English) Overall | 8 in. |
Height (English) | 5 in. |
Length (Metric) Overall | 20.3 cm |
Lenz Laborglasinstrumente™ Microfilter Funnels
Created from borosilicate glass. Lenz Laborglasinstrumente™ Microfilter Funnels are ideal for concentrating organisms in fluid samples.
Sartorius Funnels for Combisart™
Reusable stainless steel Combisart™ Funnels for microbial enumeration and particle counting.
For Use With (Equipment) | Combisart Funnel |
---|---|
Quantity | 1 Ea. |
Material | Stainless Steel |
DWK Life Sciences DURAN™ Micro Filter Funnel
Micro filter funnels are filters with which very small quantities of solution can be filtered.
Diameter (Metric)Top | 10 mm |
---|---|
Capacity (Metric) | 2 mL |
Quantity | 10/Pk. |
Material | Borosilicate Glass (3.3) |
For Use With (Application) | Filtration of very small quantities; Filtration at reduced pressure; Qualitative inorganic analysis and preparative chemistry; Filtering |
Autoclavable | Autoclavable |
Lenz Laborglasintrumente Filter Funnels
Made of high quality materials. Each manufacturing step is tested through an extensive quality management system, based on DIN ISO 9001/EN 29001.
Lenz Laborglasinstrumente™ Borosilicate Glass Conical Filter Tube
Made of DURAN™ borosilicate glass. Lenz Laborglasinstrumente™ Borosilicate Glass Conical Filter Tubes are used for filtration of very small volumes and is highly resistant to most chemicals such as solvents, acids, and alkalis.