M2 PRESSING CONCERNS

摘要

Due to increasing machine demand, a project was developed to maximize the operating efficiency of the M2 paper machine first press section. A nip load curve needed to be determined to understand the current operating conditions and the limitations in construction. Initial assumptions provided a load curve to match expectations and roll crowns. However, over time operating conditions have changed and the resulting load curve needed to be recalculated with actual figures obtained during shutdown. For further understanding of the operating conditions deflection calculations were completed on the granite press roll. Due to age and construction, there is no simple calculation for the deflection of the suction roll and in order to obtain the relevant information an experimental method was established. Following extrapolation of results a full understanding of the actual operating set up is known. The limitations are recognized as the airbags and the construction materials of both the granite press roll and the suction roll. Future works will replace the press roll with a ceramic roll which will eliminate one limitation and allow the 1st press to operate at a higher nip load.