摘要
在内径20 mm、高3 m的提升管冷模装置上对变径结构提升管内部固体颗粒分布情况进行了研究。实验结果表明,提升管扩径段的底部锥角主要对扩径段下部的催化剂浓度和颗粒返混产生影响,60°左右的底部锥角可以减小催化剂的返混,达到较高的固含率,并控制合适的停留时间。选择较小的顶部锥角既可以减小因近边壁处与顶部锥角直接碰撞而发生滑落造成的催化剂返混,又可以实现缩径段催化剂的短停留时间。相对其它角度,60°的顶部锥角可以得到较为均匀的催化剂径向分布。扩径段的高度对扩径段内固含率的影响较为显著。当扩径段高度H与扩径段的直径D之比值在8左右时,既能实现300～400 kg/m^3左右的催化剂密度,又能减小返混。
Particle distribution was investigated through a cold-run changing-diameter mini-riser apparatus of 20 mm inside diameter and 3 m height. The results show that particle volume fraction of lower expanding section and particle back mixing of lower expanding section are affected by lower cone angle. The 60° lower cone angle can minimize back mixing of catalyst, achieve high catalyst density and maintain an appropriate residence time. Small angle of upper cone can reduce catalyst back mixing caused by collision between particles and upper cone. It can also reduce catalyst residence time in upper riser. Uniform particle radial distribution can be got with the upper cone angle of 60° . The height of expanding section has a greater impact on the solid particle percentage in this section. When the ratio of expanding section height and diameter is 8, a 300- 400 kg/m^3catalyst density can be achieved with less back mixing.
出处
《炼油技术与工程》
CAS
2009年第1期8-13,共6页
Petroleum Refinery Engineering
基金
国家自然科学基金(20490200)。
关键词
催化裂解
低碳烯烃
提升管
变径
结构
catalytic cracking, light olefins, riser, changing-diameter, construction
