为探索Geldart B类颗粒的铁矿粉流态化过程由于偏析而带来分阶段流态化特征，实验首先以平均粒径为350 μm的铁矿粉为对象，在二维流化床反应器内开展了鼓泡流态化实验研究，得到了单粒径分布铁矿粉鼓泡流态化的分阶段流态化特征，并结合粉化效应解释了分阶段流态化产生的原因；然后以三组分玻璃珠系统为对象开展了分阶段流态化实验研究，采用床层压降标准差识别分阶段流态化过程，最后对比了平均粒径相同的玻璃珠和铁矿粉系统在不同流态化阶段气泡行为特征；研究结果表明铁矿粉在流化过程中的粉化效应会导致颗粒粒径分布标准差升高，流态化过程中颗粒偏析导致出现不同气泡行为特征使床层表现出分阶段的流态化特征；结合分阶段流态化特征和床层压降标准差发现不同流态化阶段气泡行为导致标准差发生改变，稳定流态化阶段床层压降标准差趋于定值；矿粉流态化过程中存在的粉化效应，导致粒度分布标准差增大，在稳定流态化阶段气泡平均当量直径增大，气泡纵向速度和横向速度也表现出增大的趋势。

To explore the characteristics of staged fluidization caused by segregation in the fluidization process of iron ore powder with Geldart-B particles, the experimental study on bubbling fluidization of iron ore powder with average particle size of 350 μm was carried out in a two-dimensional fluidized bed reactor. The characteristics of staged fluidization of bubbling fluidization of iron ore powder with single particle size distribution were obtained, and the causes of staged fluidization were explained in combination with the pulverization effect. Then, a staged fluidization experiment was carried out on a three-component glass bead system. The standard deviation of bed pressure drop was used to identify the staged fluidization process. Finally, the bubble behavior characteristics of glass beads and iron ore powder systems with the same average particle size in different fluidization stages were compared. The results show that the pulverization effect of iron ore powder in the fluidization process will lead to an increase in the standard deviation of particle size distribution. The particle segregation in the fluidization process leads to different bubble behavior characteristics, which makes the bed show staged fluidization characteristics. Combined with the characteristics of staged fluidization and the standard deviation of bed pressure drop, it is found that the bubble behavior in different fluidization stages leads to the change of standard deviation, and the standard deviation of bed pressure drop in stable fluidization stage tends to be fixed. The pulverization effect in the fluidization process of ore powder leads to the increase of the standard deviation of particle size distribution. In the stable fluidization stage, the average equivalent diameter of bubbles increases, and the longitudinal velocity and transverse velocity of bubbles also increase.

TF543