Developing A New Type Of Energy-saving Cyclone Separator-Numerical Simulation And Experimental Study

Optimizing the inlet structure of helical declination cyclone separator was numericallystudied with computational fluid dynamics software in this paper. The optimizations of inletgeometry included inlet rotation angles(240°，300°，360°)，inlet section angles(5°，15°，25°，35°，45°)and different inlet section shape(rectangle，square，round). The Reynolds stress model(RSM) in Euler coordinate system was adopted to describe the gas phase, and the particlestochastic trajectory model in Lagrange coordinate system was adopted to describe the solidphase. The simulation results including flow field, separation performance and pressure losswere compared to the experiments, and the conclusions were as follows:(1) With the increase of inlet rotation angle, axial symmetry performance of flow fieldbecame better，swing phenomenon at the bottom of the cone weakened, the tangential velocitydecreased, reflow became serious. The pressure drops reduced and the particle grade efficienciesdecreased.(2) With the increase of inlet section angle, the tangential velocity became high; the axialvelocity in upwelling decreased and the axial velocity in down-welling increased on one side butdecreased on the other side. The symmetry of the flow field in the cone became worse and itappears swing, eccentric phenomenon and serious turbulence. Separation efficiencies rise afterdecreasing first under certain inlet velocity. When the inlet velocity increase to20m/s or more,the change of inlet section angle has a slight effect on the separation efficiency. As the inletvelocity is less than15m/s，the separation performance of45°inlet section angle is better, on thecontrary,5°is better. As the inlet section angle increases, the pressure loss of helical declinationcyclone separator rise, and the grater the inlet velocity, the faster the pressure loss grows with thechange of inlet section angle.(3) Serious swing, eccentric phenomenon were observed at the bottom of the cone for thethree entrance cyclone including round，square and rectangle; comparatively speaking, thesymmetry at the bottom of cone was worse for rectangular entrance cyclone separator. Thetangential velocity of flow field was arranged in descending order: square，round，rectangle; theaxial velocity was arranged in descending order: rectangle，round，square. The particle gradeefficiency of round inlet was best, while the particle size is less than3μm; as the particle size ismore than3μm, the separation performance of square inlet was best. The pressure loss was arranged in descending order: square, round, rectangle.(4) The experimental results show that, with the increase of inlet velocity, both theseparation efficiency and the pressure loss of cyclone separator increased. The greater the inletvelocity, the pressure drop made a more obvious change, and the greater the growth. The greaterinlet velocity has a smaller effect on separation efficiency. The simulation results agreed with theexperimental data.