Numerical Simulation Study On The Flow Characteristics Of Fiber Separation By Disc Tooth Structure Parameters Through CFD

Fiberboard is one of the most widely used wood-based panels.Wide range of raw materials,good board performance and mature production technology has made fiberboard play an extremely important role in various industries such as construction,decoration and furniture.The preparation of fiber is an important link to determine the properties of fiberboard in its production process.The fiber quality is affected by many factors in the process of its preparation such as the physical form of the wood,the equipment parameters of the fiber processing and so on.The tooth structure parameters of discs is one of the important factors,which determines the grinding degree of fiber between discs.The movement characteristics of fiber material is similar to fluid in the grinding area of the discs.Flow field characteristics are studied using Computational fluid dynamics(Computational Fluid Dynamics,abbreviated as CFD)method because of its mobility.The effect of tooth structure parameters on the fiber grinding quality is revealed.The research of the flow field characteristics in fiber separation based on CFD is an important subject.It is significative and valuable for the preparation of fiber and even the fiberboard manufacturing industry.In this paper the flow field characteristics of fiber between the discs during grinding by defibrator is simulated through CFD method.The distributions of pressure,speed and wall shear stress in the three fiber fluid area including disc gap,rotating disc and static disc are solved.The distributions are analyzed one by one binding the theory of fluid mechanics.The effect of tooth structure parameters on the distributions of the flow field characteristics is studied.The study lays the foundation for the analysis of the grinding condition in the flow field.The changes of the flow field characteristics are simulated and studied through CFD method when different tooth angle and number of circumferential teeth are set up.The effect law of the two on pressure,speed and wall shear stress is obtained;The variation of the fiber position exchange through changing flow field characteristics is revealed.The effect direction of tooth angle and circumferential teeth in the fiber preparation process is analyzed.The analysis provides reference basis for optimizing fiber separation process and obtaining high quality fiber.The motion of fiber in the disc grinding area is analyzed and deduced using fiber fluid kinetic theory based on the flow field characteristics of fiber separation.The trajectory model of fiber fluid motion is obtained;The mathematical expression of action frequency is deduced using trajectory model of fiber fluid when fiber flows through the grinding area;The correlation between the action frequency and the qualified rate of fiber is studied by the calculation of the action frequency and the statistics of fiber quality.The study provides reference for finding the best frequency and obtaining high quality fiber.The study about the effect of tooth structure parameters on fiber flow field characteristics is using fluid mechanics theory and CFD method.It is an important way to optimize the tooth structure parameters and improve fiber manufacturing technology.