Funnel, Buchner

Büchner funnel with straight sides and a fixed perforated plate. Made of glazed porcelain. For use in filtration (separation of solid matter and fluid). Filtration paper needed but NOT included. Moisten filter paper with a liquid to prevent initial leakage.
Often used in combination with a Büchner flask and tapered filter adapter cones (CH0421).

The Büchner Funnel is an essential tool for laboratories requiring efficient and reliable filtration. Its robust design and compatibility with standard filter papers make it a valuable addition to any laboratory setup. Büchner 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. A special funnel used to separate solids (sludge) from a mixture. A perforated plate or a filter paper is placed in the lower portion of the funnel to hold the mixture (wet sludge). The funnel is placed in a filter flask and a vacuum is applied to remove the liquid (dewater the sludge).

It is traditionally made of porcelain, but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a fritted glass disc/perforated plate separating it from the funnel.What size filter paper do I need for my funnel?

The main advantage in using this type of filtration is that it proceeds much more quickly than simply allowing the liquid to drain through the filter medium via the force of gravity. It is essential that the amount of liquid being used is limited to less than what would overflow the flask; otherwise, the liquid will be drawn into the vacuum equipment. 

When using a Büchner funnel, the filter paper should be large enough to cover all the holes in the funnel and create a good seal.

What size filter paper do I need for my funnel?