Mittuniversitetet

As energy prices will continue to rise long term itis very important to come up with suggestions toefficiency-improving solutions based on modificationsof the existing refining technology without largeinvestments. There are several suggestions torelatively large modifications in design of refiner platepatterns, chip pre-treatment and chip feed strategies toexisting refiners, but these suggestions are difficult toimplement, as the knowledge of the mechanismsprevalent in the refiner gap is insufficient.To solve this problem FSCN and CIT have startedresearch project, “Filling the Gap”, together with thecompanies; Dametric, Holmen, Metso, Norske Skog,Pöyry, SCA and Stora-Enso co-financed by theSwedish authorities; Vinnova and Swedish EnergyAgency. The objective of this research project is toshow how to improve the electric energy efficiency ofchip refining by means of utilizing the fundamentalknowledge of wood material properties relevant forchip refining i.e. refining hypotheses in combinationwith output variable knowledge from new andimproved refining zone measurement methods as;exact gap distance, temperature-, force- and fibrematerial radial distributions combined with thetraditional out/in-put variables used. These data will beutilized in two ways:1) Optimize refining conditions in a static way, i.e. ofconditions to maximize energy efficiency to reach thefunctional fibre properties aimed for.2) Maximize process stability and minimize qualityvariations to these functional fibre properties.This paper reports a general overview from thepreliminary results of these evaluations.