Screw Press

A Screw Press is a continuous sludge dewatering machine used in ETPs, STPs, and industrial wastewater treatment plants to reduce the water content of sludge. It uses a slowly rotating screw shaft inside a cylindrical screen to separate water from solids, producing a dewatered sludge cake with minimal power consumption.

How Does a Screw Press Work?

1. Sludge Conditioning

• Sludge is mixed with polymer in a flocculation tank.
• Fine particles combine to form larger flocs.

2. Sludge Feeding

• Conditioned sludge enters the screw press unit.

3. Gravity Drainage Zone

• Free water drains through the screen openings.

4. Compression Zone

• The rotating screw gradually compresses the sludge.
• Pressure increases as the chamber narrows.

5. Cake Discharge

• Dewatered sludge cake is discharged continuously.
• Filtrate water is collected and returned to the treatment process.