Percolation

The percolation (from the Latin " percolare " - leaked ) describes the through- flow of water through a solid substrate. This can lead to the emergence solution or precipitation of minerals; the washed particles called percolates. Percolation is also referred to as a bead Eger constriction.

Commonly, this term is mainly in hydrology, it includes the ground seeping water quantity. It comes only to percolation, when the field capacity, ie the maximum water storage capacity of the soil against the force of gravity exceeded. If this process over the entire thickness of the unsaturated zone ( vadose zone ), then groundwater recharge.

In pharmaceutical technology, the percolation is used for the extraction of vegetable substances. Here a usually warm solvent such as water or alcohol is passed through the plants or plant parts. A well-known example of the percolation is the preparation of filter coffee. If several percolators connected in series as is referred to (in practice up to five ), this also as repercolation.