高温气流中铁矿粉热分解和还原行为数学模型

为研究伴随高温气流下落过程中铁矿粉的热分解和还原行为的规律,在气粉两相流运动方程基础上,联立热分解、还原反应的动力学方程,以及气流、粉粒和炉壁之间的传热方程,建立了该过程的一维数学模型,应用计算机求解数学模型,求得各种条件下的出口反应率均与实测值符合很好,证明了本模型的适用性,进一步应用该模型研究了气体流量、组成、炉温及粉矿、粒度等实验条件对粉矿的停留时间、升降温曲线及反应行为的影响,从理论上解释了不同实验条件下的实验结果。

Mathematical Model of Thermal Decomposition and Reduction Behaviors of Fine Iron Ore in Hot Gas Flow

Thermal decomposition and reduction behaviors of fine iron ore are studied under falling-down conditions accompanied with a hot gas flow. A one-dimensional model is thus developed by way of establishing the simultaneous kinetic equations of thermal decomposition and reduction reaction,based on a kinematic equation of particies in 2-phase gas-particle flow,and the equations of heat transfer among gas flow,particles and furnace wall. The model is solved on computer and the reduction rates computed at tapholes under different conditions are shown in conformity with those measured and proved available for use. The model is also applied to the study on the effects of such experimental conditions as gas flowrate and composition, furnace temperature and particle size on the holding time of particles. temperature raising/lowering and reaction behavior,thus clarifying theoretically the experimental results under different conditions.