Study On Optimum Design Of The Spindle System Of High Consistency Disc Refiner

Disc refiner is a key grinding and pulping equipment of papermaking industry, which performance will affect the efficiency of enterprises, and the spindle system of disc refiner is the essential components to make the machine work normally. The gap of disc refiner is very small, in the Fine grinding zone to a minimum of 0.1mm, the dynamic disc will be skew if the rigidity of spindle disc refiner is insufficient, it can cause two discs collide with each other, the damage to disc refiner is relatively large. Therefore, the study how to improve the stiffness of disc refiner spindle is necessary.Firstly, the paper reviews the representative structure of the single disc refiner and three disc refiner, and summarizes the advantages and disadvantages, then the design of a 60 inch high concentration single disc refiner spindle structure was made, and getting the simplified mechanical model of the spindle system.Then, based on the introduction of several commonly used static optimization method of machine tool spindle, the study makes static optimum analysis through draw on the experience of the static optimum analysis method of machine tool spindle, the relationship of stiffness between double rolling bearings with single rolling bearing is determined, getting the stiffness calculation model of disc refiner spindle, and getting the overhang values according to the structure, then the computational model of spindle stiffness was calculated by using MATLAB, obtaining the best span value in the end. The static analysis for disk refiner shaft is made by using ANSYS, simplifying the bearing as spring, the spring has the same stiffness with bearing, the static optimization design was verified to be true through the analysis of displacement deformation of disc refiner spindle in four groups of span.Finally, this paper introduces several common methods for dynamic modeling, and makes constrained modal analysis of disc refiner spindle by using ANSYS based on the theory that building dynamic modeling by using the finite element method. According to the first six order natural frequency to obtain the corresponding critical speed, the results show that the actual speed of the disc refiner spindle is less than the first critical speed, but the difference is small, therefore, the model analyses of disc refiner spindle are made with the span is 600mm,750mm and 800mm, the results shows that the dynamic performance is good when the span is 750mm, and it is in range of reasonable span, so it is selected as the final span of spindle considering the analysis results of the static optimization and dynamic optimization.This study obtains the best value of span of disc refiner spindle through the static optimum design and dynamic optimum design, and be analyzed and verified by ANSYS, shows that the optimum design is consistent with the actual situation.