Buchner funnel is a kind of glass instrument used in laboratory. It is made of borosilicate glass 3.3 and is used for filtering by vacuum or negative pressure suction. The shape is cylinder , and the bottom of the cylinder has a sealed-in perforated plate, which opens many small holes. A  narrow cylindrical outlet is attached below.

Before use, it is necessary to prepare filter equipment, such as vacuum pump, filter bottle, Buchner funnel holder (sealing ring), vacuum tube (rubber tube), filter paper, Buchner funnel, etc. When using, the filter paper is usually padded on the bottom of the cylinder. The diameter of the Buchner funnel should be matched with the diameter of the filter paper. The appropriate size of the filter bottle and rubber plug are selected. The Buchner funnel is installed on the filter bottle through the rubber plug. The side opening of the filter bottle is connected with the air pumping system. First, wet the filter paper with water and pump, so that the filter paper is firmly attached to the perforated plate of the Buchner funnel, which can prevent the leak of the things to be filtered. Slowly pour the filtrate through the glass rod into the Buchner funnel, then turn on the machine to extract it. It can be stirred slightly, leaving only the filtrate material. It is often used to extract crystals in organic chemistry experiments. After the filtration is completed, a small amount of pure solvent can be used to wash away the impurities on the crystal surface.

Sealed-in perforated plate: 1# :80-120μm, 2# :40-80μm,3# :15-40μm, 4# :5-15μm