International technology Group ANDRITZ has received an order from Mayr-Melnhof Karton to supply a Vertical Screw Thickener (VST) dewatering system for the RMP (Refiner Mechanical Pulp) process at the mill in Frohnleiten, Austria. Start-up is scheduled for the fourth quarter of 2020.
ANDRITZ will install its latest dewatering technology – the Vertical Screw Thickener (VST), an innovative screw press with a vertical design. The pulp is fed in from the top and then compressed and dewatered as it moves downwards. The self-filling and gravity-assisted dewatering principle allows higher throughput and pulp dryness because the available screen area is fully used.
The new ANDRITZ system also comprises a dilution conveyor, MC pump including standpipe and a TurboMix agitator. Automation, instrumentation, engineering, mechanical installation, commissioning and start-up supervision are also part of the scope of supply.
At the Frohnleiten Mill, the RMP with Freeness of 350 ml is dewatered from an inlet consistency of 3.5% to 25% consistency at the discharge in one innovative unit. The pulp is then stored at a consistency of 10% in a new pulp storage tower that feeds the existing board machines.
The existing RMP system was supplied by ANDRITZ in 1996 and processes a mixture of wood chips containing spruce, larch and fir as raw material for the mill’s own board machines producing CRB (Coated Recycled Board).