Research On Flow Field Analysis And Optimization Design Of Vertical Shaft Impact Crusher

Vertical shaft impact crusher is a kind of sand making equipment,which is widely used in construction aggregate production,ore grinding and other industries.At present,the vertical shaft impact crusher generally has problems such as low sand production rate,poor particle size distribution and short service life of the crusher,which are closely related to the poor effect of the crusher rotor structure on the acceleration of materials and unreasonable setting of crusher working parameters.Although scholars at home and abroad have made some research achievements in rotor structure design,there are few studies on the influence of crushing cavity flow field on the crushing effect of materials,and the understanding of the influence law of crusher working parameters on the crushing effect of materials is still incomplete.Therefore,this paper uses the secondary acceleration theory to improve the rotor structure and uses the method of discrete element and fluid mechanics(FLUENT-EDEM)co-simulation to simulate the flow field of the crushing cavity.On this basis,the optimization research work on the structural parameters and working parameters of the rotor was carried out,which provided a theoretical basis for the development of new and efficient vertical shaft impact crusher and efficient application of the crusher.Firstly,taking the rotor of PL840 vertical shaft impact crusher with independent intellectual property rights in a certain enterprise in Guizhou province as the research object,the relationship between the realization of secondary acceleration of materials and the main structural parameters of the rotor was studied in depth with the theory of secondary acceleration.The FLUENT-EDEM coupling analysis method was used to simulate the flow field of the crushing cavity.The velocity,collision position and frequency,crushing energy consumption and turbulent flow energy of the material particles at different speeds and different particle sizes were analyzed in depth,which evaluated the influence of gas on particle breakage,verified the secondary acceleration effect of the designed secondary acceleration rotor on the material,and revealed the influence of rotor structural parameters on the fracture effect.Based on the simulation analysis of the flow field in the crushing cavity,a method combining FLUENT-EDEM simulation,orthogonal test and MATLAB regression analysis were proposed to optimize the rotor structure parameters which affect the materialacceleration effect and determine the rotor structure parameters which can achieve the best material acceleration effect.According to the rock fragmentation theory,the fracture model of the material was established.Then the reliability of the material fracture model in the discrete element simulation was verified by the single particle fracture theory and the inversion method.The material fracture simulation experiment was carried out under different working parameters.Based on the bond bond fracture ratio,the working parameters of high efficiency and energy saving crusher with different feed grades were determined,which provided a theoretical basis for the optimization of crusher working parameters.