Metris addIQ RheoScan from ANDRITZ – automatic polymer dosage in sludge dewatering

ANDRITZ presents Metris addIQ RheoScan – the latest generation of its optical measurement system for automatic polymer dosage in sludge dewatering to increase process stability and reduce operating costs. It has now been installed for the first time in a deinking line.

Metris addIQ RheoScan measures the actual sludge conditions in the thickening and dewatering processes in real time with the aid of a smart camera system. The polymer dosage is adjusted as needed to match changing flow rates and sludge conditions – automatically and with the utmost precision. This makes almost fully autonomous operation possible around the clock.

Originally, this measurement and dosing system was developed for belt presses and gravity tables used to dewater municipal and industrial sludges. Now the first Metris addIQ RheoScan unit has been installed in a paper mill. The sludges remaining after a deinking process can barely be dewatered by mechanical means without adding flocculants, and the flocculent dosage has to be adjusted to suit varying sludge quality and volumes. If this is not done efficiently, flocculent is wasted.

At the LEIPA paper mill in Germany, Metris addIQ RheoScan is dewatering sludges with widely varying composition, consistency, and feed flow on a gravity table – with convincing results. Not only is the sludge consistency constant before feeding to the screw press, the goal of 10% flocculent savings was also met. As a result, the expected payback time has been reduced to less than two years.