The Numerical Simulation And Experimental Research On The Flow Field Distribution Of Jet Flotation Machine

With the promoted mechanization of coal mining, the constantly growing washing rate of coal and continuously increasing fine coal content entering into flotation system, higher requirement is proposed for the property of flotation machine. As promising flotation equipment, jet flotation machine has got rapid development in recent years. However, study on the flow regularity inside the flotation cell of jet flotation machine is still at its initial stage. As the motion state of fluid inside the flotation cell is a key factor influencing the property of flotation machine, it is essential to have a research and exploration on the flow regularity inside the cell of jet flotation machine.At present, there is only one method for circulatory material input of jet flotation machine, that is, impact downward from the upper side of the cell body. Since the change of circulatory material input will cause the variation of flow field structure inside flotation cell, this paper carries out a research on the flow regularity inside the flotation cell of jet flotation machine when different circulatory material input methods are adopted. The research is completed with the technical support of theoretical analysis, Fluent analog computation, particle image velocimetry test (PIV test). Through analyzing the basic theory of flotation and technical characteristics of jet flotation machine, the paper introduces the basis of proposing computation and experimental model as well as their major content; it conducts analog computation for the flow field of each model with computational fluid dynamics software Fluent and has an analysis and discussion about the analog results; besides, it makes use of the principle of similar analog to design working system of laboratory test cell and model machine, and applies particle image velocimetry (PIV) system to test the flow field of the experimental model.Through the analog computation of flow field inside the cell of Short hollow throat air mixing device model, the impeller model, the stator impeller model, and the baffle model when different circulatory material input methods are adopted, and the PIV test for the impeller model and the baffle model, the paper conducts a comparative analysis of the analog and computation results, to come to the conclusion that the test result can well accord with the result of flow field obtained by analog computation, which indicates the rationality of the computational model and shows that the flow regularity inside the flotation cell can be predicted by means of analog computation. The analysis and discussion on the flow regularity of different model presents a clear knowledge of the motion regularity inside the flotation cell, and the final results have shown that the flow field structure of the stator impeller model and the baffle model is more reasonable than that of other models.