| At present, some good progress were obtained in the research work of rotor structuraldesign, the wear resistant parts’ wearability and product quality of vertical shaft impactcrusher.However, as the broken object,the behavioral state of stones and the relations withrotor and crushing chamber were researched seldom in the work of crusher.Therefore, theparticles in crushing chamber flow field are researched in DEM simulation and gas-solideanalysis by combining the modern crushing theory with particle mechanics simulation anddiscrete element method with computational fluid dynamics numerical method, which willundoubtedly good for not only mastering the motion law of particles and air in crushingchamber flow fleld and improving the product quality but also impelling the innovative designof the rotor and enhancing the development level and market competitiveness of enterprisewith great theoretical and practical significance.Firstly, the discrete element analysis was researched on the conventional rotor in the flowfield of crushing chamber, the rotor model and particle mechanics model were all establishedwith the use of discrete element software EDEM and3D design software Solidworks.Therelationship between particles acceleration and rotor contact area, particles velocity andparticles force, single particle motion and the role of vertical plate, particles acceleration andwear resistant parts were all researched in the simulation process of rotor,showed that theparticles acceleration process could be divided into material whereabouts,material dispersionand material acceleration,the material acceleration was completed mainly in the region of thevertical plate and the butt ends,resulted in the wear of middle butt ends was the most serious,about80%of particles obtained a higher projectile speed, and the role of relationship betweenparticles velocity and particles force showed the effectiveness of improving the crushing effectwith the changes of particles velocity significantly affect the particles force.The same time,dueto the presence of complete acceleration and incomplete acceleration,the motion state ofparticles thrown from the conventional rotor into crushing chamber was chaotic.The flow field of crushing chamber was researched by TRIZ theory of inventive problemsolving, included system analysis, resource analysis and material-field analysis, and thefunctional model of vertical shaft impact crusher was also established, identified the problem crux of the conventional rotor, and clarified the effectiveness that the new rotor solved thedrawbacks of relatively low broken rate and great product size range in the production ofvertical shaft impact crusher.The new rotor with different structure of radius combination,impact plate mounting angle and different size of feeding particles were analysed by thediscrete element software EDEM, determined the best structure of rotor and impact plateinstallation radius and the impact plate mounting angle300*500*2°, the suitable feedingparticles size was about30mm.The flow field of crushing chamber was analysed by the comparison of gas-solid couplinganalysis and discrete element analysis with the computional fluid dynamics software FLUENTand discrete element software EDEM,the research included the interaction effect ofparticles-particles and particles-air, particles collision area,particles flow velocity,brokenprobability,single particle trajectory and energy consumption and the motion law of air were allanalysed,obtained the interaction relationship between particles collision area with brokenprobalility and energy consumption,broken probability was higher in the collison choppingblock region and there was no direct relationship between the number of particle collisionswith the crushing energy consumption.When the rotor speed1400r/min,particle accelerationwas higher,the number of collisions was suitable for reforming crushing,the power efficiencywas lager and the impact of particles to chopping block was moderate; The effect of airflow toparticles increased with the reduction of particles size,the discrete role of small particlesincreased in the airflow,and the number of collisions between particle-particle andparticle-chopping block increased well;On the contrary,with the reduction of particles size,theincrease of volume fraction of particles in flow field made the effect of particles to airflowmore and more obvious,improved significantly the motion stress and turbulent kinetic energyof the flow field. |
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