Research On Characteristics Of Two-phase Flow And Structural Optimization Of Cyclone Separator

Cyclone separator as a two-phase separation device,because of its simple structure,low operating cost,high temperature and pressure resistance,it was widely used in the field of industrial dust removal.However through investigation,Secondary flow such as short-circuit flow at the bottom of the exhaust pipe existing,particle re-entrainment of hopper in the cyclone separator may easily cause particles to escape during the separation process,which reduced the separation efficiency,and showed the distribution characteristics of the flow field inside the separator have an important influence on its separation performance.This subject took Stairmand high-efficiency cyclone separator as the research object,and used the method of numerical simulation and experiment to study the distribution characteristics of the two-phase flow field inside the separator,revealing the cause of secondary flow in the separator and its effect on separation performance.On this basis,the optimization measures of the built-in apex cone structure were determined,and the best geometric dimensions,installation positions and operating conditions of the structural optimization measures for the apex cone were obtained,the main research work and conclusions are as follows:Firstly,the Fluent software was used to numerically analyze the two-phase flow field of the cyclone separator,and on this basis,the particle escape amount was quantified by the DPM sampling function to obtain the factors influencing the separation efficiency of the cyclone separator and their importance in turn are particle re-entrainment of hopper,short-circuit flow at the bottom of the exhaust pipe,and longitudinal circulation in the separation space.Secondly,taking the separation efficiency and the pressure drop of the separator as the evaluation indicators,the influence of the geometry size and installation position of the apex cone on the separation performance of the separator is explored.The results showed that the optimal bottom diameter of the apex cone is 0.84B,and the best installation position is the vertical distance between the bottom of the apex cone and the cone is 0.375B?B_s?0.5B.Compared with the cyclone separator without apex cone,The total separation efficiency increases by 11.5%,and the pressure drop of the separator increases by 8.29%,that is,the built-in apex cone structure optimization measures are to increase the separation efficiency of the separator on the basis of increasing a small pressure drop.And build an experimental bench with the same geometrical size as the numerical simulation to measure the separation performance parameters of the separator under seven different working conditions,the experimental measurement results are consistent with the simulation results,indicating the effectiveness of structural optimization measures and the accuracy of numerical simulation methods.Finally,using separation efficiency and separator pressure drop as evaluation indicators,the influence of operating conditions on the separation performance of the separator is explored.The results showed that the apex cone's inhibitory effect on the particle re-entrainment of the hopper decreases with the increase of the inlet velocity,the total separation efficiency gradually increases first and then decreases with the increase of inlet velocity,and the pressure drop is proportional to the square of the inlet volume flow.The apex cone's inhibitory effect on the particle re-entrainment of the hopper at different inlet particle concentrations is less different,the total separation efficiency increases with the increase of inlet particle concentration,and the pressure drop decreases with the increase of inlet particle concentration.