Failure Prediction And Analysis Grinding Roller Of Pulverizer Based On Numerical Simulation Method

With the continuous development of society,the demand and quality requirements for ultrafine grinding powder are getting higher and higher,and high pressure pulverizer is a kind of stable and efficient grinding equipment in common use.However,the grinder roll,the key parts of the high pressure pulverizer,is easy to fail under the environment of high temperature,high pressure,humidity and complex stress which not only reduces the life cycle of the pulverizer,but also presents great security risks.Due to the high production cost,long manufacturing cycle and many restrictive conditions of grinder roll,taking relevant measures to prevent failure is the most direct and effective method in order to extend the life cycle of the grinder roll.The corresponding stress nephogram,strain nephogram and deformation are obtained in this paper by finite element method to stimulate the actual grinding process of grinder roll,then the failure form,cause and mechanism of the roller are studied by failure analysis and fault tree analysis method,and the corresponding failure prevention measures are taken to prolong the service life of the roller and improve the use safety and reliability,the main research contents include the following aspects:(1)The three-dimensional statics model of the grinder roll shaft and the roller surface was established,and the force of the grinder roll was analyzed by using Newton’s third law and the silt pressure theory.ANSYS Workbench was used to carry out static analysis and modal analysis on grinder roll,and the results of displacement neographs of grinder roll shaft and roller surface joints,static stress deformation positions,1～8 order natural frequency and amplitude were obtained,which provided static numerical simulation data support for the analysis of grinder roll failure.(2)By combining Rayleigh dissipation function,Lagrange equation and grinder roll motion physical friction mechanics,the system simulation mechanical model of grinder roll crushing ore material was established.The dynamic three-dimensional model of the roller and the ore was established in Solid Works,and the actual grinding process of the grinder roll was simulated and analyzed by ANSYS/LS-DYNA software.After the post-processing of the LS-Pre Cost module,the equivalent stress curve of the roller shaft and the surface of the grinding roller with time,the equivalent stress cloud map and the position of stress concentration are obtained,which provide the dynamic simulation and numerical simulation data support for the failure analysis of the grinder roll.(3)Combined with the static numerical simulation data and dynamic numerical simulation data of the grinder roll,Fault Tree Analysis(FTA)is used to establish the failure tree of the grinder roll to analyze the possible failure forms of the grinder roll.The failure cause is analyzed and the failure probability is calculated by the fuzzy mathematics method.In order to improve the safety,reliability and service life of the grinder roll,the failure prevention measures should be taken in terms of the design,manufacture,heat treatment process and service environment of the grinder roll.