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.
CONTISAND does not require the traditional backwash facilities (which includes pumps, sequencing ON/OFF valves, water holding tanks) nor PLC/DCS inputs as the operation of a CONTISAND system is continuous and self-adjusting. It only requires pressurized air or gas either provided by a utility system or generated by a dedicated small compressor
The production of the Unidro CONTISAND is standardized. Modular diameters are available and for each diameter different layer depths may be selected. Several materials for wetted parts are available (such as CS, SS, FRP and others). Fresh water, seawater, produced water and even saturated brine may be treated without any corrosion issues.