The Influence Factors Of The Verge Stress And Its Plastic Zone Development Of Large Blast Furnace Shell Tuyere

The blast furnace has been the most important, economical and effective method of making iron, has been one of the most effective chemical reactions and heat exchangers, has been an important link of iron & steel production. The structure of blast furnace shell is complicated, whose design, production, transportation, installation and so on bring about many new problems relating to all of design. As hole-intensive, it will cause stress concentration on the local area after opening; stress on local area reaches its yield possibly under changes in the status of the furnace and the corresponding fluctuations of the furnace shell in the circumstances, which entered the plastic state. The stress of general structure can not allow reaching the yielded state in the traditional design of allowable stress, but it is still permitted in some condition, that yield phenomenon of small-scale exists because of the stress concentration around the hole. Therefore, one needs to know the regularities of the stress concentration after opening, especially the state of the stress concentration and plastic development at large opening.In the paper, we use modeling calculation by the computer simulation method and FE soft "ANSYS", study the four factors which impact on the verge stress and its plastic zone development of large blast furnace shell tuyere in the room temperature and normal working state (including rate of blast furnace stack cooling hole BF tuyere, adjacent tuyere spacing, tuyere thickness and its stiffener thickness). The investigation takes the forms of the following parts:The first part is building and analyzing 6 different models of blast furnace stack cooling hole by finite element software "ANSYS", and we find that the rate of furnace stack cooling hole could weaken the strength of furnace shell, but the Influence of constraint is changed little to tuyere partial models with increasing rate of furnace stack cooling hole.The second part is building whole and partial models which includ 10 finite element models of non-tuyere stiffener thickness in group A, analyzing the Influence of the verge stress and its plastic zone development with different tuyere spacing, and we find that the change of blast furnace tuyere bearing capacity is little when the tuyere spacing is greater than 80 mm.The third part is building 6 whole models and 6 partial models of different blast furnace shell tuyere spacing in grate B, analyzing the Influence of the verge stress and its plastic zone development with different tuyere spacing, and we suggest the minimum distance between tuyeres is 100 mm.The fourth part is analyzing the Influence of the verge stress and its plastic zone development with different tuyere thickness and stiffener thickness, building 8 models of different tuyere thickness and 5 models of different stiffener thickness, and the rationality of the relevant empirical formula of code is verified.