[Continuous Sand Filters]

The Principle of Operation

Incoming water is distributed to the bottom of the filter and flows upward through the sand where it reaches the filtered water outlet at the top side of the filter.  Simultaneously within the filtration process, the sand is migrating downwards and then lifted by an airlift to the top where contaminated sand is cleaned in a sand washer and the suspended solids are discharged within this wash water. Cleaned sand then falls downward onto the filtering sand layer.