颗粒形状对烧结矿填充床内渗透系数和阻力系数的影响

来源期刊:中南大学学报(自然科学版)2021年第4期

论文作者:刘训良 张四宗 温治 张辉 刘晓宏 王帅

文章页码:1066 - 1076

关键词:颗粒形状;渗透系数;阻力特性;流动状态;烧结矿;填充床

Key words:particle shape; permeability coefficient; resistance characteristics; flow regime; sinter; packed bed

摘    要:为了分析烧结矿竖罐式冷却工艺的可行性,有必要研究不规则烧结矿颗粒填充床内的气体流动特性。首先,采用排水法、等体积法和称重法等方法表征烧结矿的颗粒特性;其次,利用自制试验台测量烧结矿填充床内的气体流动阻力,并重点分析颗粒形状对床层内阻力特性、渗透性和气体流动状态的影响。研究结果表明:烧结矿颗粒的不规则程度随着粒度增加而增加,导致床层空隙率逐渐增大;单位床层高度的气体流动阻力随着颗粒的不规则程度增加而呈指数关系降低;床层渗透性随着颗粒的不规则程度增加而增加,而惯性阻力效应则与之相反;颗粒形状会对烧结矿床层内的气体流动状态产生显著差异,尤其在较低的气体速度下。此外,由于颗粒形状不规则,床层内的气体流动大部分处于过渡区和湍流区;ERGUN方程的预测平均值低于实测值69.03%,表明ERGUN方程不适合预测不规则颗粒床层内的流动阻力,但利用本文形状因子修正的阻力关联式可以较好地预测烧结矿填充床内的气体流动阻力,平均相对误差为3.65%。

Abstract: To analyze the feasibility of the sinter vertical tank cooling process, it was necessary to study the gas flow characteristics in the packed bed with irregular sinter particles. Firstly, the particle characteristics of sinter were characterized by the drainage method, equal volume method, and weighing method, etc. Secondly, the gas flow resistance in the sinter packed bed was measured by the self-made experimental apparatus, and the influence of the particle shape on resistance characteristics, permeability and gas flow regime was analyzed. The results show that the irregularity of sinter particles increases with the increase in the particle size, which leads to the increase of the bed voidage. The gas flow resistance per unit bed height decreases exponentially with the increase of the particle irregularity. The bed permeability increases with the increase of the particle irregularity, whereas the inertial resistance effect is opposite. The particle shape has a significant effect on the gas flow regime in the sinter packed bed, especially at the low gas velocity. Moreover, the gas flow in the sinter bed is mostly in the transition and turbulent regimes due to the irregularity of the particle shape. The predicted value of the Ergun equation is on average 69.03% lower than the measured value, which indicates that the Ergun equation is not suitable for predicting the flow resistance in the packed bed with irregular particles. However, the resistance correlation modified by the shape factor can well predict the gas flow resistance in the sinter packed bed with the mean relative error of 3.65%.

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