Can we increase the proportion of electrical energy into fibre development in existing HC-refiners?
Paper i proceeding, 2014
Currently some 5 % of the electrical energy input in high consistency refining can be attributed to fibre development work. The rest is related to thermo- dynatnical steam generation. Can this unfavourable relation between fibre development and heat generation eventually be improved? A pre-requisite to consistent improvement is a stable process, controlled to targets deduced from profound process evaluations. This statement is elaborated based on two case studies and extensive refiner modelling. It is indicated that a well designed process including its basic process control can with proper refiner control reach energy reductions in excess of 20 %. Proper selections of process targets aligned with choice of segments can further increase the energy reduction in existing lines. These drastic energy reductions will demand concurrent observations and process modelling based on spatial measurements in the refining zone rather than slow, inadequate feedback control from pulp property measurements downstream. This will furthermore stress the need for more advanced control schemes if the full potential is to be captured. Additionally this approach will be a key element in the development of novel process approaches with even larger potential of energy reduction.