立式镁还原罐还原过程中结构传热特性分析

Analysis of structural heat transfer characteristics of vertical magnesium reduction tank in reduction process

为解决镁还原罐耗损大、寿命短的问题,本文根据国内外金属镁的还原工艺现状,综合考虑了温度、固定端数、罐长和罐厚对立式镁还原罐承载能力的影响,采用ANSYS有限元软件对立式镁还原竖罐的结构特性进行热力耦合模拟,得到还原系统应力场以及罐体温度场等,并对还原罐屈曲应力极限进行了研究,优化了还原罐的结构特征。同时考虑装料量对罐体强度的影响,研究装料量与还原罐温度场、还原罐屈曲应力极限之间的规律,对还原罐结构进一步优化。结果表明:物料层的导热和还原反应吸热使得物料中心与物料边缘处的升温速度有较大差距;增加中心管可适当减少镁罐的还原周期,且对镁还原反应的影响不大;高温载荷可导致还原罐屈曲应力大幅度降低(20%以上),对变形量影响较小,因此应尽量降低还原罐的工作温度。

In this paper,in order to solve the problem of large consumption and short life of magnesium reduction tank,the bearing capacity of the vertical magnesium reduction tank was studied with respect to temperature,number of fixed end,length and thickness of tank taking into account to the present situation of reduction process of magnesium metal at home and abroad. Finite element method was used by ANSYS software to simulate the reduction process,tank body temperature and stress fields of the reduction system. Structure characteristics and buckling stress limit of the vertical magnesium reduction tank were studied. The influence of the material volume strength of tanks was considered at the same time to figure out the rules between material volume and temperature field,and the buckling stress limit of the reduction tank. Results showed that the large difference of heating rate between the center and edge of material was affected by the conduction of material layer and endothermic of reduction reaction. The existence of the central tube could reduce the reduction period of the magnesium tank properly,which had little influence on the reduction reaction of magnesium. The high temperature load could reduce the buckling stress of the reduction tank by more than 20%,and has little effect on the deformation. Therefore,the working temperature of the reduction tank should be reduced as much as possible.