The screening tank pre-screens crude oil containing up to 10% solids (also known as foots) from the presses before final filtration or clarification in a decanter. The tank is sized to typically provide 30 to 60 minutes settling time and buffer storage.
The solids are separated from the oil by a dredging mechanism that picks up the solids from the bottom of the tank and drags them across a wedge wire screen. The oil returns to the tank, where it is extracted from the top of the reservoir for final clarification. The dredged solids are removed for further processing by an inbuilt discharge conveyor.
