Paper Pulp Rejects Dewatering Screw Press, Gujarat, India

Optimizing Feed Consistency Before Dewatering

To ensure optimal performance of the screw press, the first critical step is pre-thickening the pulp rejects. This is commonly done using a Side Hill Screen (Parabolic Screen) or a Rotary Drum Screen, which increases the consistency from 1–2% up to 8–10%. This intermediate consistency is ideal for screw press operation, as a lower feed consistency can result in poor dewatering efficiency and higher energy usage.

Dewatering with the Screw Press: High Impact Reduction

Once thickened, the material is fed into the Dewatering Screw Press, which efficiently removes a large portion of the absorbed and free water. Based on pulp characteristics, the screw press increases consistency from 8% up to 30–40% in a single pass. This over 70% reduction in water volume transforms the pulp rejects into a much denser and drier output—significantly reducing handling costs and opening up possibilities for further utilization.

Key Benefits of Pulp Reject Dewatering

• Massive Volume Reduction: Up to 65–70% reduction in volume due to moisture removal.
• Improved Transport & Handling: Drier material is easier to manage and significantly reduces transportation costs.
• Fuel Source Potential: The dewatered rejects can be further dried and used as an alternative fuel in energy recovery boilers.
• Lower Waste Disposal Costs: Reduces frequency of landfill trips and the cost of disposal.
• Minimized Odour & Spoilage: Drier material reduces microbial growth and improves site hygiene.
• Continuous, Low-Maintenance Operation: Ideal for paper plants running 24/7 operations with minimal downtime.