基于试验和数值分析的浮选机停留时间分布特性研究

The Experiment and Computational Analysis of the Residence Time Distribution Characteristics in the Flotation Cell

浮选机停留时间分布研究对于认识大型浮选机内短路和死区等异常流动具有重要意义。本文采用示踪试验的方法研究了实验室和工业浮选机的停留时间分布特性。电导率示踪法可以有效应用于实验室浮选机的RTD研究,而荧光示踪法可以解决工业浮选机三相体系下的RTD研究。应用CFD方法研究了动态体系下浮选机的流态特征,揭示了示踪剂在浮选机内的流动过程,CFD方法揭示出浮选机内的停留时间分布特征与理想搅拌反应器相似,说明具有很好的搅拌混合效果。在世界最大的680m3浮选机开展了停留时间分布特征研究,平均停留时间达到理想平均停留时间的89%,说明浮选机内短路和死区等异常流动较少。

The research on the distribution of residence time of flotation machine is of great significance for understanding the abnormal flow such as short circuit and dead zone in large flotation machine.In this paper,the tracer experiment method is used to study the residence time distribution characteristics of laboratory and industrial flotation machines.The conductivity tracer method can be effectively applied to the RTD of laboratory flotation machines,and the fluorescent tracer method can solve the RTD research under the three phase system of industrial flotation machines.CFD method is applied to study the flow pattern of the flotation machine in dynamics system and to reveal the flow process of tracer in the flotation machine.The method reveals that the residence time distribution in the flotation machine is similar to that in an ideal stirred reactor,which indicates that the stirred reactor has good mixing effect.The distribution characteristics of residence time is studied in the world’s largest 680m3 flotation cell.The average residence time reaches 89%of the ideal average residence time.It is demonstrated that there are less abnormal flows such as short circuits and dead zones in the flotation machine.