宽粒径矿物颗粒流态化反应停留时间分布的结构调控与模拟优化

With the increasing requirement of the integrative processing capacity for mineral fluidized reactor, it is stringent to deal with the problem of mismatching between the fluidized residence time and the required reaction time due to the wide distribution of particles size, which would lead to the poor product. In this study, the characteristics of residence time distribution along with the influence factors of solids with a wide size distribution are investigated experimentally, it is adopted the comprehensive methods of improving the bed configuration, adjusting the baffle position, altering the locations of solids inlet and outlet and others to control the time distribution, the effect of the above measures and the corresponding mineral fluidization processes are simulated based on the established model of “structure-activity” relationship between heterogeneous structure and momentum transfer, heat transfer, mass transfer, and chemical reaction, which is likely going to solve difficult problems in early design, optimum control and scale-up of fluidized process and equipment in the future.

随着人们对矿物流态化反应器综合处理能力要求的不断提高，克服颗粒的宽粒径分布引起的流化停留时间与所需反应时间不匹配，而导致反应产品质量下降的问题显得更为迫切。本研究首先通过实验测量宽粒径颗粒的停留时间分布规律及其影响因素；之后通过采取改进床层结构、调节构件布局和调整进出料口位置等综合措施实现对宽粒径停留时间的有效调控；最后采用基于非均匀结构与“三传一反”的“构效”关系模型模拟调控措施的影响效果及相应的矿物流态化反应过程，并将上述成果应用于该类反应器的初步设计、优化调控和工业放大当中。

停留时间分布对于流态化反应器的放大与优化具有重要影响。课题系统地开展了对多级垂直折流流化床停留时间的特性研究，通过调节流化气速和进出料速率等措施有效调控了宽粒径颗粒RTD，并形成一定的理论性成果；采用基于结构的气固流动模型对单、双粒径以及挡板调节RTD进行了模拟研究，实现对宽粒径颗粒RTD有效调控的准确预测（2017 Particuology, 2017 Chinese J. Chem. Eng., 2017 Chem. Eng. J.）；并将相关研究结果应用到20万吨/年低品位软锰矿流态化还原项目，在系统连续稳定运行的基础上，实现MnO2还原率高于95%（2017 国内专利）。课题执行期间，共发表SCI收录论文3篇，申请国内专利1篇。