To increase the D.S.-content of sludge, Greendex proposes SCRUDRAIN® dynamic thickeners with Archimedean screw inside.

These are generally used as prethickening for filter presses, belt filter presses, centrifuges and drying beds to achieve higher sludge concentration before dewatering.

Sludge thickeners are also used to increase the sludge concentration before biogas reactors or just as filters to remove coarse material such as fibres in the textile industry. The concentration of D.S. in the outlet from the sludge thickener can be achieved by changing the speed of the Archimedean screw (e.g.: sludge with 0.5- 3% D.S. can be thickened to 5-15% D.S.). Standard SCRUDRAIN® -thickeners are made of stainless steel AISI 304.