Charging behavior in a bell-less blast furnace based on 3D discrete element method
-
摘要: 利用三維離散元法建立了無鐘高爐布料模型,分析了料罐、旋轉溜槽中的顆粒流動行為以及顆粒離開溜槽后的下落軌跡和料堆形成,可視化再現了裝料過程.結果發現:爐料在流動過程中始終存在粒度偏析,料罐排料流為漏斗流,小顆粒由于偏析而傾向于后期排出;溜槽傾角對顆粒流動行為和料堆形成影響較大;溜槽內顆粒流由于溜槽旋轉而向側上部偏離和翻動,小顆粒因靠近壁面而位于料流內側,大顆粒因聚集在溜槽上部而處在料流外側,爐料顆粒偏析、偏轉翻動和速度分布影響下落軌跡;在爐料下落到料面的堆積過程中,大顆粒易于向爐喉中心和邊緣偏析,小顆粒因位于料流內側和滲透作用而分布在堆尖下方且偏向中心側.結合激光網格爐內測量技術料流軌跡測量結果,驗證了模型的適用性.Abstract: A bell-less blast furnace charging model was established by using 3D discrete element method. The flow behavior of particles in the hopper and rotating chute, the falling trajectory and heaping process of particles discharged from the rotating chute were modeled and analyzed by using this model. Consequently, the charging process was reproduced visually. It is found that size segregation is always prevalent throughout the flow process of particles. The discharging flow from the hopper is funnel flow, and small particles tend to be discharged in the later stage due to size segregation. It is proved that the influence of chute inclination angle on the particle behavior and heaping process is very significance. The granular flow in the chute deviates upward to one side and tumbles attributing to rotation. Small particles close to the chute wall surface move to the inside of the stream, while large ones staying at the upper part of the chute flow move to the outside. The falling trajectory of particles is affected by particle size segregation, deflection and tumbling, and velocity distribution. During the process of burden falling and heaping, large particles are apt to segregate to the center and periphery of the furnace throat, while small particles locate under the pile top and they are partial to the center due to locating inside the stream and permeation. The applicability of the model has been verified by the measurement results of burden trajectories based on the laser grid in-furnace measure technology.
-
Key words:
- blast furnaces /
- burden trajectories /
- burden distribution /
- laser grid method /
- discrete element method
-

計量
- 文章訪問數: 131
- HTML全文瀏覽量: 28
- PDF下載量: 11
- 被引次數: 0