IMPULSE DRYING SLUDGE

In a new approach to energy-efficient sludge dewatering, sludge is contracted briefly under pressure by a hot surface. The steam generated at the interface between the sludge and the surface forces out some of the water in liquid form. Laboratory demonstrations with belt-pressed primary sludge from a paper mill removed more than 20 additional percentage points of water. Corresponding values from municipal sludge and from a mixed primary/secondary industrial sludge were 10 and 15 additional percentage points, respectively.