密相输运床径向颗粒体积分数分布的研究

摘要

The radical solids volume fraction profiles were investigated in a dense transport bed (0.102 m in ID × 17 m in height) with the silica sand belonging to Group B. The results show that the radial solids volume fraction profiles are non-uniform; solids volume fraction is low and almost the same near the riser center (r/R = 0-0. 7) ; solids volume fraction increases significantly in the adjacent zone (r/R =0. 7-0. 9) ; solids volume fraction becomes the highest near the wall (r/R = 0. 9-0. 97). As the solids circulation rates increase or the riser air volume decreases, solids volume fraction increases at each radical position. The increase of solids volume fraction is the largest near the wall and relatively small near the riser center. At last, a correlation for predicting radical solids volume fraction profiles was proposed. The predictions of the correlation can work well for both Group A and Group B particles.%在提升管高17m,内径0.102m的密相输运床冷态实验装置中,采用B类石英砂颗粒,针对径向颗粒体积分数分布进行了研究.结果表明,径向颗粒体积分数分布不均匀:提升管中心至近壁面附近(r/R=0-0.7),颗粒体积分数较低且基本一致；近壁面处(r/R =0.7-0.9)颗粒体积分数显著升高；壁面附近(r/R=0.9-0.97)达到最大.增加固体循环流率或降低提升管气量,各径向位置颗粒体积分数都增加.其中壁面附近最为明显,提升管中心至近壁面附近变化较小.文中建立了径向颗粒体积分数分布描述关系式,对于A类颗粒和B类颗粒实验结果都能较好地预测.