【摘要】 本文以重实大颗粒物料的加工为背景,在内径130 mm 的多孔挡板流化床中研究了气体的流动和相间交换特性。采用气体脉冲示踪技术,计算机与热导池联用,采集、处理停留时间分布(RTD)数据,研究了气速、静床高、挡板开孔率及孔径对气体交换的影响。提出了两相活塞流并流模型。计算的 RTD 与实测 RTD 较好吻合,证明该模型能较好描述本实验系统中的气体流动及相间气体交换。更多还原

【Abstract】 Gas-flow characteristics and gas interchange rate between phases were inves- tigated in a 130 mm-diameter fluidized bed equipped with perforated baffles for processing coarse and heavy particles.By using transient tracer method, the residence-time distribution(RTD)curves have been measured with heat con- ductivity cell connected to computer.The gas interchange rates,K,between phases were calculated from the RTD curves.The effects of gas velocity,fixed bed height,free area and diameter of the hole of the perforated baffle on K were investigated and a correlation was obtained.It was found that the effects of gas velocity and fixed bed height on K is serious,but free area,expe- cially the diameter of the hole is slight.RTD curves obtained from two phase model with concurrent plug flow agree with experimental curves quite well.It proved that the proposed model is suitable to describe the gas flow in the ex- perimental system.更多还原