Büchner Flask (Filter Flask)
A Büchner flask, also known as a vacuum flask, filter flask, suction flask, side-arm flask, Kitasato flask or Bunsen flask, is a thick-walled Erlenmeyer flask with a short glass tube and hose barb protruding from its neck. The short tube and hose barb effectively act as an adapter over which the end of a thick-walled flexible hose (tubing) can be fitted to form a connection to the flask. The other end of the hose can be connected to source of vacuum such as an aspirator, vacuum pump, or house vacuum.
The thick wall of the Büchner flask provides it the strength to withstand the pressure difference while holding a vacuum inside. It is primarily used together with a Büchner funnel fitted through a drilled rubber bung or an elastomer adapter (a Büchner ring) at the neck on top of the flask for the filtration of samples. The Büchner funnel holds the sample isolated from the suction by a layer of filter paper. During filtration, the filtrate enters and is held by the flask while the residue remains on the filter paper in the funnel.
The Büchner flask can also be used as a vacuum trap in a vacuum line to ensure that no fluids are carried over from the aspirator or vacuum pump (or other vacuum source) to the evacuated apparatus or vice versa.
- Capacity : Available from 50ml up to 1 000ml
- Joint Size : Available in 19/26
- Side Arm: 8mm (Accepts 9mm bore flexible tubing)
- Material: Borosilicate 3.3 Glass
- Strain Point: -515°C
- Annealing Point: 565°C
- Softening Point: 820°C
- Stopper: Not Included
- Print: Blue or White
- The image is for reference only