Dewatering Screw Press Machine, A dewatering screw press is a screw press that separates liquids from solids. A screw press can be used in place of a belt press, centrifuge, or filter paper.It is a simple, slow-moving device that accomplishes dewatering by continuous gravitational drainage. Screw presses are often used for materials that are difficult to press, for example, those that tend to pack together.The screw press squeezes the material against a screen or Filter and the liquid is collected through the screen for collection and use