摘要
利用幅值鉴频的激光多普勒测速技术,同时测定并流下行循环流化床（CDCFB）中的气体和固体的局部速度,由此可以获得气固间的局部滑落速度。实验证明,包含提升管的并流下行循环流化床明显改善了床层结构的均一性,最大局部滑落速度比单颗粒的滑落速度高出许多倍,而且滑落速度的极值点位置与颗粒浓度有关,说明在并流下行循环流化床及提升管中存在明显的颗粒团聚现象。
A feasible Laser Doppler Velocimetry technique based on Amplitude Discrimmation has been used to determine the local gas and solids velocity simultaneously, which can lead to the local slip velocity between the gas and solids in a cocurrent downflow circulating fluidized bed (CDCFB).The experimental and analytical results show that the highest local slip velocity is many times greater than the slip velocity of single particle, and the pole position of the slip velocity profile is in correspondence with that of the particle concentration. It is suggested that there should be obvious particle aggregation phenomenon in CDCFB as well as in a riser.
出处
《化工学报》
EI
CAS
CSCD
北大核心
1995年第2期180-187,共8页
CIESC Journal
基金
国家自然科学基金资助项目
关键词
速度
循环流化床
并流下行
气固两相流
流化床
local velocity, slip velocity, circulating fluidized bed, cocurrent downflow, aggregation
