Research Of Reclaiming Mechanism Of The Bucket Wheel Stacker-reclaimer Based On EDEM Simulation

Bucket wheel stacker-reclaimer is one kind of large, efficient, and continuous handling equipment developed from bucket wheel excavator. It is widely used in industries such as thermal power, metallurgy, port, steel, and cement and so on due to its great capacity of loading and unloading, easy operation and automatic control. But up to now the design of bucket wheel stacker-reclaimer has mainly referred to design specification of bucket wheel excavator. Those two machines have different working nature and condition, which makes the design of bucket wheel stacker-reclaimer conservative and rely heavily on empirical parameters.Discrete element method(DEM)is a new numerical computation way to study the bulk materials’ mechanics and kinematics characteristics arising in recent years, it breaks the traditional design theory’s analysis limitation of regarding the bulk materials as continuum, which can be broadly used to design and optimize bulk material handling equipment. But the accuracy of DEM relies on the rationality of simulation parameters which should be calibrated before the simulation.Therefore, this dissertation completes two innovative and important work:( 1) Using the angle of repose experiment to calibrate the material’s contact property parameters(including coefficient of restitution, coefficient of static friction,and coefficient of rolling friction)and the particle’s dimension enlargement factor after comparing the commonly used DEM calibration methods; furthermore analyzing the influence of those two types of parameters on the bulk material’s filling characteristics especially the angle of repose.(2)Using the calibrated parameters to simulate the reclaiming process of the bucket wheel mechanism under different rotational speeds in EDEM and do comparison with the traditional design method to study the reclaiming mechanism as well as acquire a series of beneficial conclusions.The shining features of this dissertation lie in three aspects:( 1) Using the DEM to simulate the reclaiming process of bucket wheel stacker-reclaimer which expands the design method of bucket wheel stacker-reclaimer.The analysis of filling capacity and digging resistance of bucket wheel can help todesign bucket wheel mechanism.( 2) Analyzing the influence of contact property parameters and particle’s dimension enlargement factor on the bulk material’s filling characteristics especially the angle of repose through orthogonal tests and obtaining a set of meaningful conclusions.(3)Guaranteeing the accuracy of simulation to the greatest extend by building non-spherical particle models and parameter calibration based on angle of repose experiment which can be used for reference.