Abstract:

In many gas-solid rapid reaction processes, a turbulent jet is an ideal form for the mixing between gas-phase raw materials and solid particles. It is meaningful for understanding reaction processes by using effective measuring techniques and analysis methods to obtain the mixing behavior of jet and gas-solid two-phase flow. The dynamic data of particle concentration is obtained using fiber optic probe technology. On this basis, based on the traditional analysis method of particle clusters in the riser and combined with wavelet analysis, the procedure for identifying clusters in the mixing zone of jet and gas-solid two-phase flow was proposed. Furthermore, the instantaneous contact state between gas and solid in the jet influence zone was divided into three phases, i.e., the cluster phase, the dispersed particle phase, and the jet phase that was not thoroughly mixed with particles. By combining the theory of jet attachment and the gas tracing method, the centerline equation of the jet under ideal conditions was modified. The results obtained can be predict the development trend of jets in the gas-solid two-phase flow. By using ozone decomposition tracing technology, the local reaction results during the mixing process of feed jet and gas-solid two-phase flow were obtained. By combining this result with gas-solid dynamic mixing characteristics and jet trajectory model, the influence of flow parameters on the reaction can be analyzed.

Key words: jet, gas-solid two-phase flow, gas-solid mixing, cluster, streamline model

摘要：

湍流射流是气固快速反应过程中气相原料与固体颗粒的理想混合形式，采取有效的测试技术与分析方法获得射流与气固两相流的混合行为对研究反应过程具有重要意义。本文采用光纤探针技术获得了颗粒浓度动态数据，以提升管内颗粒聚团的传统分析方法为基础，结合小波分析，提出了射流与气固两相流混合过程中颗粒聚团的确定方法，并将射流影响区内气固间的瞬时接触状态分为颗粒聚团相、散式颗粒相以及未与颗粒充分混合的射流相。结合附壁射流理论，利用气体示踪技术获得的射流特征浓度分布结果，对理想条件下的射流中心线方程进行了修正，所得结果可预测气固两相流中射流的发展趋势。利用臭氧分解示踪技术，获得了原料射流与气固两相流混合过程中的局部反应结果，将其与气固动态混合特征及射流轨迹模型相结合，可分析流动参数对反应的影响。

关键词: 射流, 两相流, 气固混合, 聚团, 流线模型