Research On The Vertical Mill Grinding Roller's Grinding And Mechanical Property & Structural Optimization

With the development of mining,cement,metallurgy and other industries,the grinding equipment industry has entered a stage of rapid development.As a grinding and drying equipment,the vertical mill has obtained attention increasingly of relevant enterprises by virtue of its small footprint,low energy consumption,Long life and other advantages.The foreigners have had long experiences in the designing and using of vertical mill,and have rich engineering experience,as a result,their products always have better overall working performance,but the price is expensive and the maintenance costs are always high.Domestic enterprises are basically making vertical mill by imitating foreigner molding products through analogy design,with little theoretical research,the products always have problems such as too high energy consumption and low efficiency.The main research contents of this subject are to focus on several key problems,to do theoretical analysis using latest research methods and to optimize the key parts based on existing technology and research results.Firstly,this paper summarized the mainstream grinding theory and took the tyre shaped grinding roller and cone shaped grinding roller as the objects of study,both of these two kinds of grinding roller are widely used in engineering,and established the mathematical model of the stress distribution of two roller using latest grinding theory,and wrote the analysis program in Matlab.After analysis,the stress distribution characteristics of two rollers under different deflection angle of the grinding roller,grinding force and the thickness of materials were obtained,simultaneously compared the stress distribution of two rollers under the same working conditions,result shows that compared with the cone shaped grinding roller,tyre shaped grinding roller has more uniform stress distribution and smaller peak stress,and so the tyre shaped grinding roller's working performance is better.This paper briefly introduced the hydraulic system of typical vertical mill,and established the simulation model in AMESim,by simulation using a single variable method,the influence of the volume of accumulator,the accumulator inflation pressure and the diameter of connecting tubing on the pressure maintaining capacity was obtained,and future analyzed the influence of thickness change of materials on the working characteristic of the hydraulic system.Finally,facing with the problems that the weight of traditional roller shaft is too heavy and the processing technology is poor,the grinding roller shaft was optimized from solid structure to hollow welded structure,and went on the static analysis in ANSYS Workbench environment,obtained the distribution of stress and deformation in loaded state,by comparing with it of the solid roller shaft,confirmed the reliability of the hollow welded shaft.And then calculated the fatigue life of the shaft under working load in nCode Designlife software,ensured that the hollow welded shaft will meet the fatigue life requirement if the thickness is more than 35 mm.The results of this study provide a powerful analytical method and design basis for the design of vertical mill,and have high value in engineering to guide the production of vertical mill simultaneously.