The buchner funnel is constructed with a flat plate inside the circular vertical-sided funnel where a filtering paper is placed. It is used for suction filtration of liquids. Vacuum suction is used to pull the liquid into the cylinder of the funnel and through the plate. The advantage of the Buchner funnel is that provides a quicker filtration of liquid than allowing gravity to draw the liquid through the funnel.
Great for collecting recrystallized compounds.