Abstract: In order to overcome shortcomings of commercialized gas-solid draft tube-lifted air loop reactor, a novel gas-solid annulus-lifted air loop reactor (ALALR) was proposed. Experiment was conducted to investigate local bed density distribution. The circulation driving force increased with the increase of superficial gas velocity in annulus, but decreased with the increase of superficial gas velocity in draft tube, and even became negative when it reached 0.2 m/s. The bed density was influenced by configuration of ALALR and showed an ununiform radial distribution. The bed was not well fluidized below the draft tube (r/R≤0.47) with the bed density close to 820 kg/m3, but was well fluidized in the lower annular region (0.47≤r/R≤1.0) with the bed density lower than 450 kg/m3. When the superficial gas velocity in annulus increased from 0.2 to 0.54 m/s, the mean bed density in the annulus region and draft tube region decreased about 70 and 33 kg/m3, respectively. Interestingly, with the increase of the superficial gas velocity in draft tube from 0.06 to 0.2 m/s, the mean bed density increased about 90 kg/m3 in the annulus region, but decreased to about 33 kg/m3 in the draft tube region.

Key words: airlift loop reactor, gas-solid system, particle density, particle circulating velocity

摘要： 针对工业化中气-固环流反应器存在的缺陷，提出了一种新型的环隙气升式气固环流反应器. 在一套冷模装置内系统地考察了局部床层密度分布. 实验中实现了稳定、连续的环隙气升式环流，环流推动力随着环隙区表观气速的增加而增加，随着导流筒区表观气速的增加而减小，当导流筒区表观气速为0.2 m/s时，颗粒环流方向改变为中心气升式. 受结构特性的影响，催化剂密度在导流筒区和环隙区沿径向的分布具有一定的不均匀性，在底部r/R≤0.47区域颗粒未能充分流化，床层密度接近820 kg/m3，在底部0.47≤r/R≤1.0区域颗粒流化较好，床层密度小于450 kg/m3；随着环隙区表观气速由0.2 m/s增加至0.54 m/s，环隙区、导流筒区平均密度分别降低约70和33 kg/m3，随着导流筒区表观气速由0.06 m/s增加至0.2 m/s，环隙区平均密度增加约90 kg/m3，导流筒区平均密度降低约33 kg/m3.

关键词: 环流反应器, 气固体系, 床层密度, 环流速度