双颗粒提升管中细颗粒的混合行为研究(Ⅱ)──弥散颗粒的轴径向混合行为

FINE SOLIDS MIXING IN A BINARY-SOLID RISER(Ⅱ)──AXIAL AND LATERAL MIXING OF DISPERSED FINE SOLIDS

利用磷光颗粒示踪技术，使用点源示踪的方法在不同的径向位置测得反映颗粒径向扩散行为的停留时间分布曲线，并对弥散细颗粒的径向混合行为进行了分析．提出二维扩散模型描述所测量的停留时间分布曲线特征．实验发现弥散细颗粒的径向扩散Peclet数随粗颗粒加入量的增加而增加，随细颗粒浓度的增大而增大，而几乎不随气速变化．给出了一个与实验数据吻合较好并可适用于单颗粒提升管的关联式．

Experimental results of the axial and lateral mixing of dispersed fine particles in a binary-solid riser are resented.Using point source tracer injection,the lateral solids dispersion is determined by measuring the solids RTD at different radial positions.A proposed two-dimensional dispersion model describes the measured RTDs satisfactorily.The laterar fine particle Peclet number increases with increasing the fraction of coarse particle and changes little with increasing gas velocity.A correlation of the lateral Peclet number governs the measured experimental data well.