APPARATUS FOR CLEANING OF LIQUIDS COMPRISING A GRANULATED FILTER MATERIAL

摘要

The present invention concerns a granulated material and the use of this in depth filters for the cleaning of liquid. The material consists of grains of one single material with varying density and diameter. The grain density increases when the grain diameter decreases in such a way that an ideal distribution of the grain size from coarse to fine in the flowing direction of the liquid down through the filter bed is achieved as a result of the sedimentation of the grains after ended backwash and corresponding expansion of the bed. The filter bed's design and properties can be adapted to various filtration purposes and the entire filter bed can be supplied as one total package from the same supplier. The properties of the grains can be manipulated and an ideal filter bed can be put together to optimise cleaning processes and the use of the filter, without the need of using several filter media.