Utveckling av mothållssystem till valsar

Sammanfattning: This Master Thesis is a product development project that has been carried out in cooperation with Metso Paper Sundsvall AB. The task has been to develop a holding solution that generates force between two rolls and to evaluate the new solution with respect to functionality, manufacturing, structural stability, costs, assembly etc. The roll holding solution is a system that is part of a rollpress. The rollpress is used to wash and dewater pulp. The existing solution creates forces that have to be absorbed by the gable of the press. The objective was to reduce the weight of the gable and reduce the material cost. The thesis work started with a feasibility study on pulp manufacturing and wash principles, a study of the rollpress and the existing roll holding system was also performed. Conceptual solutions were developed. The concepts were evaluated and one concept was chosen. The chosen solution uses hydraulics as source of power. Two hydraulic cylinders are placed between the rolls, one close to each gable. The hydraulic cylinders pull the rolls together. The forces in the gables are reduced since the forces are kept between the rolls. The hydraulic cylinders contain functions that allow the distance between the rolls to be changed between two fixed positions during operation. The distance can be changed to adapt to different production levels. The bearing houses belonging to the movable roll can move around a joint. If the roll is exposed to forces higher than the design force the roll and the bearing houses move. The friction force is kept at a minimum by moving the bearing houses around a joint, which promotes lineload measurements. The lineload is generated when pulp pass between the rolls. The developed solution includes components that allow lineload measurement.