Physical meaning of cutting edge length and limited applications of Specific Edge Load in low consistency pulp refining

Abstract Specific edge load (SEL) is the extensively employed theory to characterize the refining results in low consistency pulp refining. But the physical meaning of its core parameter, cutting edge length ({L_C}), is not very clear, resulting in the limited applications ofSELin pulp refining. In this study, the physical meaning of{L_C}was investigated in two aspects, total bar sliding length per cycle and total equivalent bar length, as well as the application of two refining intensities related to it,SELand the net tangential force per bar crossing zone ({f_t^{\mathrm{net}}}). After the comparison of the refining intensities and the experimental results, it was foundSELcalculated by the{L_C}with physical meanings can only properly characterize the results of the pulp refining conducted by straight bar plates with constant angular parameters. While, for the situations of varied angular parameters, the{f_t^{\mathrm{net}}}and Modified Edge Load (MEL), calculated by the edge length expanded empirically by Meltzer, can also better characterize the refining process, either for the evolution of fiber length or the global refining effect (pulp Schopper Riegler). In addition, the application of{f_t^{\mathrm{net}}}can be potentially expanded to other refiner plates to gain a better understanding and optimization of the pulp refining process.