并流下行循环流化床中气固速度剖面以及滑落现象的研究  

GAS-SOLIDS VELOCITY PROFILES AND SLIP PHENOMENON IN A COCURRENT DOWNFLOW CIRCULATING FLUIDIZED BED

作　　者：曹春社 金涌[1] 俞芷青[1] 汪展文[1] 

机构地区：[1]清华大学化学工程系,北京100084

出　　处：《化工学报》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

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.

关 键 词：速度 循环流化床 并流下行 气固两相流 流化床 

分 类 号：TQ051.13[化学工程]