In the continuous sludge belt thickener, the water drains through a moving polyester filtering belt, separating the solids in the sludge from the filtrate. The use of special plows improves the drainage by alternately compressing, reversing and distributing the sludge on the belt. Even the most unstable sludge can be easily treated with this unit. The belt thickener separates over 95{4f1e35c07df61488f28768334a6350a7c20f145341bf5f3233e6477760a58c2c} of the suspended solids from the sewage sludge, with a minimum consumption of polyelectrolyte.