How to Adjust the Moisture Content of the Dewatered Sludge Cake in a Multi-Disk Screw Press?

The moisture content of the dewatered sludge cake and the processing capacity can be adjusted using the back pressure plate and the screw shaft inverter (INV-1).

① Adjusting the Back Pressure Plate Gap

• Lowering the Moisture Content – Reducing the gap of the back pressure plate increases the pressure inside the screw press body, thereby lowering the moisture content of the sludge cake.
• Increasing the Moisture Content – Expanding the gap of the back pressure plate decreases the pressure inside the screw press body, resulting in a higher moisture content of the sludge cake.

⚠ Note: Do not adjust the back pressure plate gap to less than 4mm.

A smaller gap reduces the moisture content but also increases the load on the screw press, accelerating the wear of consumable parts such as the moving rings and screw shaft.

② Adjusting the Screw Shaft Inverter (INV-1)

• Lowering the Moisture Content – Decreasing the inverter frequency reduces the rotation speed of the screw shaft, lowering the processing capacity. This increases the sludge retention time inside the screw press body, allowing for better dewatering and a lower moisture content.
• Increasing the Moisture Content – Increasing the inverter frequency raises the rotation speed of the screw shaft, increasing the processing capacity. This shortens the sludge retention time inside the screw press body, leading to a higher moisture content.

⚠ Note: After adjusting the screw shaft’s rotation speed, other components of the screw press may also need corresponding adjustments.