纵向涡发生器设计参数对喷动床内颗粒两相流动影响实验研究

Experimental Study on Flow Characteristics of Gas-Solid Two-Phase in a Spouted Bed with a Longitudinal Vortex Generator

将球体纵向涡流发生器引入喷动床内,采用粒子图像测速技术研究了在内径152 mm的喷动床内颗粒密度及纵向涡流发生器排数(单排、双排及三排)对喷动床内喷射区及环隙区颗粒相径向速度的影响。结果表明:在喷动床稳定喷动范围内,颗粒密度越小纵向涡流对颗粒相径向运动的强化效果越佳。纵向涡发生器对喷动床内颗粒运动强化存在空间分布的不均匀性,在喷动床有限的空间范围内,存在最佳的静床层高度使得纵向涡流发生器对颗粒径向运动的强化效果达到最佳。整体而言,单排及双排纵向涡流发生器对喷动床内颗粒径向速度的强化效果最佳,随着静床层高度的增加,多排纵向涡流发生器对喷射区颗粒径向速度影响逐渐减小,而对环隙区颗粒径向速度的影响逐渐增大。

A sphere longitudinal vortex generator was introduced into a spouted bed to study the characteristics of gas-solid two-phase flow. Particle image velocimetry（PIV） was used to investigate the effect of particle density and row of longitudinal vortex on particle radial velocity in the spouted bed. The results show that lower particle densities can enhance longitudinal vortex. Effects of the longitudinal vortex generator on the enhancement of particle motion in the spouted bed are spatially inhomogeneous. The longitudinal vortex generator has the best performance under an optimal static bed height. The optimum row numbers of longitudinal vortex are one and two for particle radial motion enhancement. When the static bed height increases, effects of the multi-row longitudinal vortex generator on radial velocity in the spout region gradually increase, while it gradually decreases on particle radial velocity in annulus.