Dynamic stability of shaft line in a groundwood system

摘要

Torsional vibrations prevent the ossibility of controlling pulp quality using running speed variation in mechanical pulping. STo get deeper understanding of groundwood dynamic system emphasis has been put here on constructing the coupled system representation including mechanical shaft dynamics and a model of the grinding process with a fluid like representation for the compressible wood flow under material removing conditions. Analytical study gives explicit stability bifurcation for linearized system in terms of shaft line nominal speed with variation in agreement with numerical simulations with the full nonlinear system model and papermill observations. The paper includes introduction and tuning up a damping element nounted on the free end of the shaft line to limit the unwanted vibrations.