Influence of Shape of Cohesive Zone on Gas Flow and Permeability in the Blast Furnace Analyzed by DEM-CFD Model
Influence of Shape of Cohesive Zone on Gas Flow and Permeability in the Blast Furnace Analyzed by DEM-CFD Model
复制标题
DOI：
10.2355/isijinternational.55.1232
复制
发表时间：
2015-06
影响因子：
1.8
通讯作者：
S. Ueda,;T. Kon;Hiroyuki Kurosawa;S. Natsui;T. Ariyama;H. Nogami
中科院分区：
文献类型：
--
作者：
S. Ueda,;T. Kon;Hiroyuki Kurosawa;S. Natsui;T. Ariyama;H. Nogami
在20世纪70年代的高炉解剖研究中，认识到铁矿在其中进行软化和熔化的黏结带的重要性。1)黏结带通常位于高炉中部，从竖井下部向下至风口。据报道，黏结带形成不同的形状，即；不对称，倒v型或w型，2)根据高炉的运行条件。黏结区内铁矿层由固相和液相组成，液相浸没在固相之间的空隙中。矿层中空隙率降低，导致透气性恶化。黏结区透气性远低于块状区和滴状区。在高炉的常规操作中，采用矿石与焦炭交替进料的方式，形成炉料层状结构，控制瓦斯流量。焦炭层在粘结力区起通风狭缝的作用。高炉填料床的透气性决定了高炉的风量极限，直接限制了高炉的生产效率。因此，为减小煤气流动阻力，有必要对炉膛内的粘结区和炉料移动床结构进行优化。为了减少二氧化碳的排放，人们积极研究低还原剂用量的高炉运行。3-7)为建立CO2减排技术，COURSE 50项目考虑在高炉中使用氢气，采用DEM-CFD模型分析黏结带形状对高炉内气体流动和渗透率的影响
The significance of cohesive zone in which softening and melting of iron ore proceed was recognized in the dissection studies of blast furnace in 1970s.1) The cohesive zone usually locates in the middle part of the furnace, from lower part of the shaft down to the tuyeres. It was reported that the cohesive zone is formed in different shapes namely; asymmetric, inverted V-type or W-type,2) depending on the operating condition of the blast furnace. The iron ore layer in the cohesive zone is composed with solid and liquid phases and the liquid phase is soak into the void space among the solid phase. The void fraction in the ore layer decreases and then the gas permeability is deteriorated. The gas permeability of cohesive zone is extremely lower than that of lumpy or dripping zone. In conventional operation of blast furnace, layer structure of burden materials is formed to control the gas flow by charging the ore and coke alternately. The coke layer acts as the ventilation slits in the cohesive zone. Gas permeability of packed bed in the blast furnace determines the limits of the blast volume, and directly limits the productivity. Therefore, it is necessary to optimize the cohesive zone and the structure of the moving bed of burden in the furnace for decreasing gas flow resistance. To mitigate CO2 emissions, blast furnace operation with low reducing agent rate has been actively investigated.3–7) To establish CO2 reduction technology, the COURSE 50 project is considering using hydrogen in a blast furnace as a Influence of Shape of Cohesive Zone on Gas Flow and Permeability in the Blast Furnace Analyzed by DEM-CFD Model