Numerical Simulation And Experimental Research Of Bidirectional Impinging Stream Mixing Tank

Nowdays, with the comprehensive mining coal, the proportion of fine-grained coal rises gradually. It make clean coal ash can't meet users needs. In this article, bidirectional impinging stream mixing tank is designed, cleaning slime surface in plup-mixing unit, thus improving selection of the fine grained coal, in order to achieve the purpose of reducing clean coal ash.Mixing tank model is divided mesh by Gambit software. Using computational fluid dynamics software, it is simulated in single-phase flow. Through the analysis of turbulent intensity and velocity field, thus on the impeller blade Angle for 60°, leaf number for 4, impeller spacing for 45mm, distance between bottom and impeller 22mm and 6 baffle mixing barrel were selected. In solid-liquid two-phase flow simulation, through comparative analysis of the common blade Angle 45℃and 60°in solid-phase volume fraction and the turbulent intensity and velocity field of mixter, the impeller blade angle for 60°is best selection.Laboratory experimental results, flotation of stirring shaft 45°-4J,60°-4J and 60°-6J in baffle 4 mixing tank, ash and yield of clean coal rise, with increase the distance between the impeller and bottom. Impeller spacing 45mm, the experimental results are mostly good and coincide with simulation results in the single-phase flow. Flotation the impeller of shaft 6 in baffle 6 mixing tank ash of clean coal basely decline, when the distance between the bottom and impeller increase. Impeller spacing 60mm, the experimental results are mostly good.Different shaft impeller spacing in different situations and different from the case of the impeller from the bottom baffle 4 and 6, respectively, in the mixing bucket baffle effect on flotation, the mixing blade shaft angle of 60°than 45°shaft, consistent with the results of computer simulation, stirring axis 60°-6J overall effect than the other two shaft, blade number 4 the simulation results are contradictory.Three kind of stirring shaft at the case of different impeller spacing and different distance between impeller and bottom respectively in baffle 4 mixing tank and in baffle 6 mixing tank on flotation,the effect of blade shaft angle of 60°is better than that of 45°, consistent with the results of computer simulation. 60°-6J stirring shaft is superior to others and conflict with the results of computer simulation.Comparative experiments of different shaft respectively in baffle 4 mixing tank and in baffle 6 mixing tank on flotation, the effect of baffle 4 mixing tank is obviously good.The best experimental conditions:stirring shaft:60°-6J; mixing tank:4 baffle mixing tank; impeller spacing:54mm; distance between impeller and bottom:30mm.In the best experiment condition, comparative experiments of flotation about changping coal in high-intensity conditioning and flotation machine. High-intensity conditioning is much better than flotation machine. Bidirectional impinging stream mixing tank can achieve the expected purposes of research subjects.