Research On Separation Effect Of Heavy Medium Cyclone Under Coaxial Rotating Magnetic Field

In order to investigate the effect of the composite force field formed by the rotating magnetic field and the centrifugal force field on the separation of the heavy medium cyclone using magnetite powder as the heavy medium,this paper will use the alternating magnetic field of NS,the magnetic field of all N and N / S Diagonally arranged magnetic field is placed coaxially on the top cover and barrel of the heavy medium cyclone,and the coaxial rotating magnetic field placement position,magnetic pole arrangement,magnetic field strength,magnetic field rotation speed and feed pressure are placed on the heavy medium cyclone Research on the impact of sorting.Experiments were carried out on the distribution law of heavy medium in the cyclone,and at the same time,the specific test conditions were selected to conduct the coarse slime separation test,and the separation effect was evaluated.The static magnetic field simulation analysis function in the finite element analysis software ANSYS MAXWELL was used to analyze the magnetic field characteristics.The coaxial rotating magnetic field is installed in the cyclone.When a static magnetic field is installed,the flow rate in the pipeline increases greatly and the pressure decreases greatly.As the rotation speed increases,the flow rate decreases and the pressure increases.When a static magnetic field is added,the underflow density is greatly reduced,and the overflow density is increased accordingly.As the rotation speed increases,the overflow density begins to decrease and the underflow density begins to increase.In addition,under different magnetic field strengths and magnetic pole arrangements,there are differences in the amplitudes of underflow and overflow density.The coaxial rotating magnetic field was installed at the position of the top cover of the cyclone.The results of the coarse slime separation test showed that the ash content of +1.5 mm particle size was reduced from 15.66% to 11.34%,and the tail coal ash content was slightly increased from 80% to 80.32%.The ash content of 1.5-1 mm particle size was reduced from 13.20% to 10.77%,and the ash content of tailings was slightly reduced from 76.83% to 76.50%.The ash content of 1-0.5 mm particle size was reduced from 12.39% to 10.05%,and the ash content of tailings was reduced from 76.96% to 75.66%.The ash content of 0.5-0.25 mm granular clean coal increased from 11.20% to 11.61%,and the ash content of tail coal decreased from 77.97% to 74.94%.The ash content of 0.125-0.25 mm clean coal increased from 11.87% to 14.04%,and the ash content of tail coal decreased from 85.78% to 84.86%.The rotating magnetic field is beneficial to the sorting of coarse slime with particle size above 0.5 mm.When the coaxial rotating magnetic field is located in the cyclone barrel,the ash content of each grade of coal is reduced by more than 0.25 mm,the ash content of +1.5 mm particle size is reduced from 16.57% to 14.29%,and the ash content of tail coal is slightly increased from 80.85% to 81.01%.The ash content of 1.5-1 mm granular coal was reduced from 13.73% to 12.57%,and the tail coal ash content was reduced from 77.35% to 75.97%.The ash content of 1-0.5 mm granular clean coal was reduced from 12.60% to 11.30%,and the tail coal ash content was reduced from 77.69% to 76.14%.The ash content of 0.5-0.25 mm granular coal was reduced from 11.25% to 10.64%,and the tail coal ash content was slightly reduced from 80.51% to 80.19%.The ash content of 0.125-0.25 mm granular coal has increased from 11.51% to 11.91%,and the tail coal ash content has remained basically unchanged.The heavy product distribution curve shows that the presence of a static magnetic field reduces the sorting density and accuracy compared to when there is no magnetic field,and the sorting accuracy and sorting density decrease slightly when the magnetic field is rotating.In addition,the changes in ash content under different magnetic field strengths,feed pressures,and magnetic pole arrangements are compared.As the strength of the magnetic field increases,the ash content of clean coal basically shows a downward trend.Under different magnetic pole layouts,the ash content of each grade of clean coal corresponding to the N-S layout is the lowest.As the feed pressure increases,the ash content of each grade of clean coal shows a downward trend.Using ANSYS MAXWELL finite element analysis software,simulation calculation and analysis of different magnetic pole layouts and different magnetic field strengths were carried out.The results show that in the all-N arrangement,although the geometric center position is far from the magnetic pole position,it still retains a strong magnetic field strength,and the distribution of magnetic induction lines is messy.In the N-S arrangement,the magnetic field strength at the geometric center is basically zero,but the distribution of magnetic induction lines is regular.When the magnetic poles are arranged diagonally,the distribution of the magnetic field strength is uneven,and there is a weak field strength at the geometric center.In the course of coarse slime separation test,the separation effect is better under the N-S layout,indicating that the composite force field under the N-S layout is more suitable for the separation of coarse slime.In the course of coarse slime separation test,under the N-S arrangement,the separation effect is better,indicating that the magnetic pole arrangement with a concentrated magnetic force range can accelerate the magnetic slurry in the cyclone,which is beneficial to the cyclone Sorting.