气基直接还原竖炉还原段参数设计方法

Design method of reduction segment parameters of the gas-based direct reduction shaft furnace

分析了气基直接还原竖炉还原段参数的影响因素,找到了各参数的研究方法;在模拟的气基直接还原竖炉还原氛围下进行了铁矿石的直接还原实验,研究了铁矿石的还原性和还原膨胀性;采用颗粒离散元仿真分析软件EDEM对颗粒炉料的传输过程进行仿真分析,研究了炉料的下降运动规律;结合实验数据和仿真结果,确定了竖炉还原段参数的表达式。研究结果表明:铁矿石在模拟条件下的必要还原时间约为3h,且还原膨胀率先增大后减小;竖炉中心炉料的下降速度大于边缘炉料的下降速度,且速度超前比受排料速度的影响较小;从上到下还原段内型曲线由3条拟合线段组成,对应的炉身角分别为:87.162°、88.949°以及90.652°。

The influence factors of reduction segment parameters of the gas-based direct reduction shaft furnace were ana- lyzed and the design methods were found. The gas-based direct reduction experiment was conducted in simulated condi- tions to study the reducibility and the reduction swelling behavior of iron ore pellets. Also, the discrete element simulation analysis software EDEM was used to simulate the transfer process of iron ore pellets to study the falling motion regular in shaft furnace. The design expressions of the reduction segment parameters were confirmed combining the experimental date and simulate result. The results show that., the necessary reduction time in simulated conditions is about 3 h and the reduction swelling index（RSI） first increase then decrease during the reduction process~ the falling speed of iron ore pel- lets is faster in the center than the edge of the direct reduction shaft furnace and different discharge rates have little effect on this regular~ the fitting furnace profile curve is composed of three line segments from top to bottom, respectively, the corresponding shaft angle are 87. 162°, 88. 949° and 90. 652°.