摘要
在有机玻璃制成的主体反应器(0.286m×3.0m)内,采用空气-水的气液两相体系考察了不同表观气速下带有中心下料管和环管式气体分布器的环流反应器内局部气含率和内环气泡上升速度的流体力学特性。结果表明:气含率均随表观气速的增大而增大;从外环流入内环的气泡数量比较少;在相同条件下外环的气含率远远低于内环的气含率;新型气体分布器的采用和液体外循环的引入可以增大床层气含率并使其分布趋于均匀,从而增大了内环中气液两相的接触面积和湍动强度,使传递过程得到强化。在此基础上采用商业软件ANSYSCFX10.0对该反应器进行了数值模拟研究,模拟结果与实验数据基本吻合,说明了基于实验验证的Euler-Euler法可以用于该反应器开发和放大研究。
The profiles of gas holdup and bubble velocity depending on superficial gas velocity were investigated in an inner airlift reactor with a down tube and an annulus gas distributor. The experimental set-up was made of plexiglass with an inner diameter of 0. 286 m and a height of 3.0 m. Air and tap water were used as gas and liquid phases, respectively. The results showed that the gas holdup increased with increasing superficial gas velocity within both inner and outer loops. The gas holdup in the inner loop, however, was much higher than that in the outer loop. The bubbles entering the inner loop from the outer loop could be neglected in the ranges of the operating conditions. When an annulus gas distributor and a down tube were installed in the conventional airlift reactor, the gas holdup increased and its distribution became uniform, which enhanced the interracial area between gas and liquid phases and the turbulent intensity of multiphase flow. Therefore, the interphase transfer would be improved in the inner loop. Then, the profiles of gas holdup and bubble velocity were simulated by using the Euler-Euler model in the platform of ANSYS CFX10. 0 software package and fair agreement between numerical and experimental data was obtained. These results implied that the CFD simulation based on the Euler-Euler model, accompanied with experimental measurement, could be used to develop and scale up this new kind of loop reactor.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2007年第7期1677-1684,共8页
CIESC Journal
基金
国家重点基础研究发展计划项目(2005CB221205)
国家自然科学基金项目(20676147)
教育部留学归国人员科研启动基金项目(2004-527)~~
