Set of Rubber Cones for Büchner Funnels with Filtering Flask (Kitasato)

Cone dimensions: top diameter x bottom diameter

Cone no. 1: 21 mm x 14 mm
Cone no. 2: 23 mm x 19 mm
Cone no. 3: 33 mm x 21 mm
Cone no. 4: 41 mm x 25 mm
Cone no. 5: 50 mm x 32 mm
Cone no. 6: 60 mm x 40 mm
Cone no. 7: 70 mm x 53 mm
Cone no. 8: 83 mm x 65 mm

The selection of the rubber cone size will depend on the Kitasato flask or filtering flask and Büchner funnel used. Sometimes it is necessary to fit two rubber cones to ensure a vacuum fit. Our recommendation for adaptation according to the flask is as follows:

Pressure filtration or vacuum filtration

Vacuum filtration is a technique for separating solid-liquid mixtures.
- The mixture is placed in a Büchner funnel with a filter paper attached to the bottom.
- The Büchner funnel is placed over a filtering flask.
- A rubber cone is placed between the mouth of a flask and the funnel.  The rubber cone will serve as an adapter to fit the funnel so that the fit does not allow leakage and the vacuum can be generated.
- A vacuum pump is applied which sucks the mixture, trapping the solid between the pores of the filter.
- The rest of the mixture passes through the filter and will be deposited at the bottom of the vessel.

This technique is faster than the usual gravity filtration and is indicated when such filtration processes are very slow.