Multi-objective Optimization Of The Large-scale Rotary Kiln Based On Health Maintenance

The rotary kiln is super large cylinder equipment which can make mechanical, physicalor chemical treatment of solid materials, and it’s widely used in building materials, metallurgy,chemical and the other industries. The rotary kiln has complex conditions in the run-time. Inthe working condition, the rotary kiln shell axis offset the theory axis which lead to theproblems such as unevenly stressing, wearing aggravates, life shortening and so on of eachcomponents. So certain axis adjustments should be made to ensure each component’s forcebeing balance and the remaining life of the various components being equal as far as possible,thus the rotary kiln device will be in a better working state and the equipment will be in healthmaintenance.Rotary kiln is a complex organic entity. Its optimal design is a multi-objective issue.Each objective impact of the equipment should be comprehensively considered in design. Inthis thesis, the refractory brick thermo-keeping effect and the effect of general structure arefully considered in the integrated mode finite element analysis. And dynamic angle of reposeof the material is added to the model calculation. Thermal-stress coupled field analysis isconducted on the rolling ring, roller, roller axle and rotary kiln shell.On the above basis of the finite element analysis, to satisfy the aim that each componentforce being balance and the cylinder axis being straight simultaneously. Take the spacingbetween the various stalls, initial value, adjustment of rotary kiln and support angle as designvariables. By Optimal Latin Hypercube design, a statistical evaluation is made out and theoptimal parameters are found. On the basis of the calculated results, a quadratic polynomialresponse surface model is created. By the analysis of response surface model analysis chart,local effect analysis chart and Pareto chart, the influence degree to the result by the initialvalue and adjustment of rotary kiln and support angle is obtained. After the calculation, thevertical and horizontal directions stress response surface model mathematical expressions ofroller are obtained.Using the above math expression, choose the remaining life of rolling ring, roller, rolleraxle being equal as the objective function.The ring supporting angles of each roller androlling is optimized. In the optimization process, the remaining life calculation of the variouscomponents of rotary kiln is written by Matlab software. Then this program is integrated intoIsight optimization software. Using simulated annealing algorithm, the iteration loops untilthe results converged. Each support angle optimal solution is found and the remaining life ofrolling ring, roller and roller axle is calculated. Finally, the optimal spacing of the rolling ringand stalls best supporting angles is adjusted to check the optimization results. By the comparison of the data before and after the optimization and after adjustment, itcan be seen certain improvements of the rotary kiln shell straightness and the life of rollingring. Meanwhile, the lifetime value of each component is more balanced based on the longerlifetime of each component. Thus the optimization goals of equal loaded, coaxial line andequal life are achieved.