Modeling And Optimization Of Ratio Of The Stiner Flow In Blast Furnace Raw Material Charging System

with the development of fine materials technology in blast furnace, the steadiness of stiner chemical composition has to meet more strict demands, and stinering process automatic control technology as well as parameter detection technology have been enhanced drastically. However, as a result of the inherent complex of stinering process, the existing optimized control technology of stinering process is still difficult to solve the problem of the steadiness of stiner chemical composition in medium and pint sized Iron&Steel Corporation in China. On the basis of field survey, the author discovered that stiner transportation would cause the mixture of different batches of stiner in this instance. This would create new problem:the chemical composition of the mixed stiner is not only unstable but also unknown. That will cause the bias between the reference value and the actual value during the process of charging mixing, more serious, will lead to furnace condition disorder and the emergence of energy crisis and environmental pollution. At present, there are many researches on the steadiness of stiner chemical composition in stinering process, but seldom about the above new problem.This subject is a part of national key project implemented in Hangzhou Iron & Steel Group. Viewing of the current shortcomings, this paper study the mathematical models of the stiner flow based on the prediction of stiner chemical composition and the optimization of ratio of stiner chemical composition among bunkers. major research work includes:1 Establish the mathematical models of the stiner flow in the bunker by the discrete element method(DEM), regard granular material of stiner as the research subject, analyze the contact forces and the criterion of contact problem among particles, between particles and bunker in detail, establish the model of three-dimension DEM in MATLAB to predict stiner chemical composition of material discharge.2 On the basis of above-mentioned research results, a new method is proposed that is by controlling the state of material discharge realizing the optimization of ratio of stiner chemical composition among bunkers, which would make the minium deviation of stiner chemical composition from the technique set value and furtherly stable stiner chemical composition. Main target method and branch-and-bound method are adopted to solve the above multi-objective optimization problem.3 Based on the above techniques, Hybrid programming with C# and MATLAB was adopted to design the modules of object modeling, control strategy and optimization algorithm, the direction system for optimal operation and predication of stiner chemical composition has implemented successfully in raw material workshop of the iron works.