Research On The Cumulative Damage Crushing Behavior Of Single Particle Materials In Impact Crushe

The vertical impact crusher has a simple structure,is easy to maintain and repair,and has higher crushing efficiency and a larger crushing ratio compared to other crushing equipment.It is widely used in the production of artificial sand.However,the vertical impact crusher has the disadvantage of poor particle size distribution,resulting in unstable and difficult-to-control quality of the artificial sand and low yield of the finished sand.To improve the product quality of crushing and grinding equipment,scholars at home and abroad have conducted in-depth research on the crushing mechanism and particle size of crushing equipment.However,due to the complex motion and crushing process of the material particles in the crushing chamber of the vertical impact crusher,a unified and perfect model for describing the crushing process has not yet been reported.Therefore,in this paper,a coupling simulation method of computational fluid dynamics and discrete element method(CFD-DEM)is adopted to study the motion and impact collision process of material particles in the crushing chamber.Based on the characteristics of material particles being crushed under cumulative impact,the falling weight impact test device is designed and optimized,and repeated falling weight impact tests are carried out to establish a mathematical model of particle crushing probability and crushing index,providing a theoretical basis for revealing the crushing mechanism of the impact crusher.Firstly,the "Sand King" PL series impact crusher produced by a heavy industry enterprise in Guizhou Province is taken as the research object,and the motion trajectory and collision frequency of particle materials in the crushing chamber are analyzed through CFD-DEM gas-solid coupling simulation,revealing the motion and impact collision rules of material particles in the crushing chamber.Based on the simulation analysis of the crushing chamber flow field,the falling weight impact test device is designed for the characteristics of material particles being crushed under cumulative impact,so that the impact crushing energy can be quickly and conveniently adjusted according to the test needs during the test process.To investigate whether the designed falling weight impact test device meets the requirements of strength,stiffness,and stability,finite element static and dynamic simulation analysis and ADAMS dynamic analysis are carried out.To solve the stability problem of the device displayed in the dynamic simulation analysis,a combination of orthogonal experiment,regression analysis,and genetic algorithm is proposed to optimize the main structural parameters that affect the stability of the device,improving the stability of the device and the reliability and accuracy of subsequent falling weight impact test results.To reveal the crushing mechanism of material particles in the crushing chamber of the vertical impact crusher under cumulative impact,the falling weight impact test device is used to conduct single particle material falling weight impact tests and incremental falling weight impact tests.The critical energy threshold and critical crushing energy of single particle materials are obtained,and the crushing probability and particle size distribution of single particle materials under cumulative impact behavior are analyzed.A function model of particle crushing probability and crushing index with three parameters of impact energy,impact frequency,and particle size is established,and the reliability of the model is verified,providing a theoretical reference for predicting the particle size distribution of the crushing product of the impact crusher.