VOLUTE DUO™ achieves up to 43.7% dryness, preparing paper sludge for subsequent drying

Background

A major Polish paper manufacturer planned to optimise its sludge management by incorporating a subsequent thermal sludge drying system. The customer operates two dewatering machines – an older type designed exclusively for highly fibrous sludges and a newer decanter centrifuge. However, these technologies would not perform well in combination with a drying system. Therefore, the customer wanted to test screw press technology, which complements the drying system much better. The screw press effectively reduces energy consumption during the drying process and serves as a more reliable alternative to the centrifuge.

Installation details

The VOLUTE DUO™ RVP-241 pilot unit, equipped with a dynamic mixer, effortlessly handled the fluctuating mixture of primary, biological, and DAF sludge. The machine demonstrated excellent operational flexibility – it can be adjusted either for a maximum cake dryness of 43.7% for more economical operation of the downstream dryer, or for a maximum throughput of 41.2 kg-DS/h. Under the optimal (balanced) setting, the press consistently delivered over 40% cake dryness with a minimal polymer consumption of 2.8 g/kg-DS and a filtrate capture rate of over 96%.

Wastewater treatment plant conditions and performance data