Study On Optimization Of Separation Performance Of Novel Cyclone Separator With Reflux Device

Particulate pollution is one of the most common factors that cause air quality to fail to meet standards.Long-term exposure to polluted air would greatly reduce the people’s immunity to respiratory diseases.For this reason,the government has issued relevant policies to control particulate matter emissions from controllable sources.However,some natural factors such as sandstorms and other uncontrollable factors can still cause air quality to fail to meet standards.Therefore,the role of air purification equipment is particularly important.Aiming at the characteristic of common air purification technologies(such as filter filtration,electrostatic dust removal,etc.),the research group proposed and designed a cyclone with reflux device in combination with the advantages of simple structure and easy maintenance of the cyclone.The difference between the cyclone with reflux device and the traditional tangential inlet cyclone was that the reflux device replaced the hopper.The particles did not need to be stored in the hopper after being separated,and were directly discharged from the reflux device.Therefore,the cyclone with reflux device could achieve continuous dust removal.Based on the experimental test of the cyclone with reflux device,the three-dimensional physical model of cyclone with reflux device was established by Solid Works software.The static pressure,axial velocity and velocity magnitude of flow field of cyclone with reflux device were calculated by Fluent software.The influence of ejection speed,particle properties,inlet flow and drainage flow on performance of cyclone with reflux device.Then,the length of the vortex finder and the length of the cylindrical section were studied for the performance of cyclone with reflux device.The simulation results show that the Reynolds stress model can simulate the threedimensional anisotropic turbulent flow field in the cyclone with reflux device.The pressure distribution,vertical velocity distribution,locus of zero vertical velocity and velocity magnitude distribution under the reference conditions were different from the traditional tangential inlet cyclone.Properly increasing the ejection speed was helpful to improve the separation efficiency of cyclone with reflux device,but the ejection speed should not exceed 15m/s.The cyclone with reflux device had higher separation efficiency for particles with higher density,larger particle size and spherical shape.Appropriately increasing the inlet flow rate could improve the separation efficiency and kept the pressure drop in a proper range.The separation efficiency increased with the increase of drainage flow.The length of the vortex finder and the length of the cylindrical section had a great impact on the performance of cyclone with reflux device.Keeping the length of the cylindrical section constant and increasing the length of the vortex finder would improve the separation efficiency,but the pressure drop would also increase.Keeping the length of the vortex finder constant,the pressure drop would decrease with the increase of the length of the cylindrical section,but the length of the cylindrical section should not be greater than 400 mm.When the length of the cylindrical section exceeded 400 mm,the separation efficiency would reduce sharply.In this paper,the numerical simulation study of cyclone with reflux device provided a reference for the subsequent optimization experiment of cyclone with reflux device.It avoided the waste of resources caused by indiscreet optimization.