基于Ergun方程的菱镁球团填充床层阻力特性实验

菱镁球团重烧竖炉内的气流流动分布较为复杂，获得料层阻力特性规律是开展竖炉内气体流动及气固换热过程研究的基础.从颗粒填充床的气体动力学出发，以Ergun方程为基础，首先系统测量了菱镁球团颗粒关键宏观特性——粒径分布、密度、球形度及空隙率;通过冷态实验修正了Ergun方程中黏性阻力系数和惯性阻力系数，获得了适用于描述菱镁球团床层阻力特性的关系式.结果表明:球形度及空隙率均随颗粒粒径的增加而增加;单位料层压降随气体流速的增加而增加，且增长趋势逐渐加剧，反之随着颗粒粒径的增加而减小.

Experiment of Resistance Characteristics for Magnesite Pellets Packed Bed Based on Ergun Equation

The gas flow distribution in the magnesite shaft furnace is relatively complicated. Obtaining the resistance characteristics in the magnesite pellets packed bed is the basis for the research on the gas flow and gas-solid heat transfer process. Starting from the gas dynamics of the gas-solid packed bed， based on the Ergun equation， the key macroscopic properties of the magnesite pellets， including particle size distribution， density， sphericity and voidage， were systematically measured. The viscous resistance coefficient and the inertial resistance coefficient in the Ergun equation were corrected through cold experiments， and a relational equation suitable for describing the resistance characteristics of the magnesite pellet bed was obtained. The results showed that the sphericity and voidage increase with the increase of particle size. The pressure drop increases with the increase of gas flow rate， and the increasing trend gradually intensifies. On the contrary， it decreases with the increase of particle size.