ABSTRACT

Despite measures to increase pulverised coal (PC) conversion, part of the injected PC leaves the raceway as char, particularly at high injection rates. The coke/PC replacement ratio and, consequently, the blast furnace (BF) operation efficiency depends on the consumption of char by reactions of secondary gasification and added burden. This contribution focuses on the change in streaming conditions in different BF zones when coal particles leave the raceway. To investigate this, a 2-D physical BF cold model was used. Tests were conducted after injecting various amounts of PC and under various gas flow rates. Particle movement and accumulation were examined by measuring the pressure drop at different positions in the model. To evaluate the effect of PC on the gas permeability in vertical and horizontal directions, calculations using the Darcy-Weisbach/Ergun equation were performed. The results will be used to improve CFD-modelling and the prediction of char behaviour in the BF.

摘要

尽管采取了提高煤粉 (PC) 转化率的措施，但注入的部分 PC 以炭的形式离开滚道，特别是在高注入率时。焦炭/PC 置换率以及因此高炉 (BF) 的运行效率取决于二次气化反应对焦炭的消耗和添加的炉料。这一贡献侧重于煤颗粒离开滚道时不同高炉区流动条件的变化。为了对此进行研究，使用了二维物理 BF 冷模型。在注入不同数量的 PC 后和在不同的气体流速下进行测试。通过测量模型中不同位置的压降来检查粒子的运动和积累。为了评估 PC 对垂直和水平方向透气性的影响，使用 Darcy-Weisbach/Ergun 方程进行计算。结果将用于改进 CFD 建模和高炉中炭行为的预测。