International technology Group Andritz received an order from Stora Enso to supply a new sludge dewatering line for thickening and dewatering of fibrous sludges at the company’s Skoghall, Sweden board mill. With a capacity of up to 750,000 tonnes per year, Skoghall is one of the world’s largest producers of liquid packaging board. Start-up of the new Andritz plant is scheduled for April 2014.
The order includes a gravity table and a sludge screw press to process up to 50 tonnes of mixed sludge per day, which will significantly increase the capacity of the existing sludge dewatering plant. The material to be dewatered consists of a mixture of fibrous and biological sludges, as well as chemical sludges from the mill’s CTMP line. The Andritz sludge screw press dewaters the mixed sludge to the highest possible dryness that can be achieved today by mechanical means.
In order to meet the new process requirements resulting from this plant extension, Stora Enso’s order also includes the rebuild of an existing Andritz belt press supplied in 1989. Due to the higher final dryness achieved through the dewatering lines in the future, Stora Enso Skoghall will be able to feed a higher amount of dewatered sludge to the power boiler and operate it with greater energy efficiency.