| Abstract:The?low-consistency?refining?process?is?a?critical?step?in?the?pulp?and?paper?industry,?with?significant?implications?for?energy?consumption?reduction,?and?optimized?control.?This?study?investigated?the?constant-gap?cyclic?refining?characteristics?of?hardwood?pulp?using?a?MD3000?low-consistency?experimental?disc?refiner?equipped?with?straight-bar?plates?featuring?a?22°?bar?angle.?The study elucidated the intrinsic mechanism of the progressive decline in refining power during constant-gap refining. It was found that the increase in beating degree of pulp led to a reduction in its viscosity and shear strain within the refining zone, thereby causing a decrease in total refining power. Furthermore, the rate of power reduction gradually increased with the elevation of beating degree.The?relative?changes?in?beating?degree?and?fiber?average?length?were?employed?to?characterize?fiber?cutting?and?fibrillation?during?refining.?A refining optimization method based on quantitative characterization of handsheet micro-morphology was developed, demonstrating significant correlation between the determined refining limit and variations in paper strength parameters. The?findings?contribute?to?the?characterization?of?low-consistency?refining?processes,?optimization?of?plate?design,?and?the?high-efficiency,?low-energy?operation?in?industrial?applications. |