Buchner funnel is a ceramic instrument used in the laboratory, used to filter by vacuum or negative pressure suction. When in use, filter paper is generally placed on the cylindrical floor first, the funnel is inserted into the upper opening of the Buchner flask and the interface is sealed (for example, with a rubber ring).
The side port of the Brinell beaker is connected with a suction system. Then the solid and liquid mixture to be separated is poured into the top of the funnel, and the liquid components are drawn into the beaker under the action of negative pressure, and the solid remains on the top.