SAND FILTERING DEVICE

摘要

A sand filtering device comprising a single layer filtering bed, or simply a filter, which allows to obtain perfectly clean water and a high operative working life at high filtering speeds. Advantageously, an appropriate, experimentally obtained correlation between the height of the filtering layer, the grain size of the used sand and the filtering speed allows a dimensioning of the filtering bed such as to ensure optimal filtering conditions. The device of the invention further allows to obtain a very effective filter back washing operation which restores the efficiency of the filter.