EDEM Simulation Analysis And Experimental Verification Of Ultrasonic Vibration Crushing Material Particles

The ultrasonic vibration pulverization system utilizes the characteristics of high frequency vibration and energy concentration of ultrasonic waves.The fascia rod amplifies the weak amplitude of the ultrasonic transducer conversion,directly acts on the material particles,and performs high-frequency impact on it to achieve the purpose of pulverization.Based on the previous studies,this paper designs an ultrasonic vibration pulverizing device with a conical transition step horn.The three-dimensional model is used to simulate the pulverization process of material particles by using the discrete element simulation software EDEM.The feasibility of pulverization treatment was simulated by simulation.The effects of vibration frequency,particle size and particle material on ultrasonic vibration pulverization were studied by simulation experiments,and the characteristic parameters were optimized,which has certain guiding significance for particle pulverization.After the optimal parameters are studied through simulation experiments,the actual experiments are carried out under the optimal conditions,using the laboratory equipment to verify the accuracy of the simulation experiment and to carry out the parameter experiment which cannot be determined by simulation.By comparing experiments under different ultrasonic power,particle size and sample material,the actual optimal parameters are determined,which has certain research value and significance for practical application.The main contents are as follows:1.Briefly describe the application of powder in various fields of national economy,the development of powder preparation and the research status at home and abroad;discuss the development process of ultrasonic processing technology and the research status at home and abroad,the application and development of ultrasonic vibration pulverization,using ultrasonic vibration to carry out ultrafine pulverization certain research value.2.Exploring the related properties of the powder and the geometric properties of the particle.Briefly describing the relevant theories of pulverization,including the pulverization method and related mechanical properties,power theory,typical particle pulverization model.Expound the principle of ultrasonic vibration pulverization,design ultrasonic vibration horn and corresponding parts according to relevant theory.The model of ultrasonic vibration pulverization system is established by using three-dimensional software,and the functions of each part of the device are briefly described.3.Using the discrete element software EDEM to establish the particle model,using the Hertz-Mindin with bonding contact model,the small particle group bonding is used to replace the large particles,and the ultrasonic vibration pulverization process is simulated.Obtained the cloud image of the particlepulverization process under high-frequency vibration,and obtained the change diagram of the bond between the particles before and after pulverization,which proves the feasibility of the simulation.4.According to the change of bonding bond,the pulverization effect is judged.The effects of ultrasonic frequency,particle size and particle material on the pulverization effect,and the vibration process cloud and bonding keys under various factors are drawn.The pulverization effect is gradually increased with the increase of ultrasonic frequency,and then tends to be stable;the optimal range of ultrasonic vibration pulverizing device is certain,if the particle size is too large or too small,it will not achieve good pulverization effect.The device is suitable for pulverizing hard and brittle materials,and the pulverizing effect gradually decreases with the increase of hardness.5.Using the experimental device laser particle size measuring instrument,super depth of field three-dimensional microscope,ultrasonic pulverizing device for verification experiments.Taking silica sand as a sample,the feasibility pulverization experiment was carried out,and three sets of experiments of ultrasonic power,particle size and particle material were carried out respectively.The particle size distribution of the particles before and after pulverization was measured by laser particle size measuring instrument,and the experimental results were obtained.In contrast,it was found that the high-hardness natural particles at the ultrasonic frequency of 38 kHz,the power of 2000 W,and the particle diameter of 200-500 ?m had the best pulverization effect.