Study on the separation efficiency of sheath flow respirable dust virtual impact separator under the influence of multiple parameters

To improve the separation efficiency of respirable dust separator in coal mine, a sheath flow virtual impact separator was designed. Through numerical simulation, the separation law of respirable dust in separator under the effect of various structural parameters, such as the spacing between nozzle and large-particle collection chamber (S), the width of the large-particle collection chamber (D), and sheath flow angle (θ), was obtained. The maximum difference between the results of experiment and simulation is only 4.72 %. The results show that the separation efficiency of separator at each particle size point increases continuously with the increase of S. When D increases, the deviation degree of the separation efficiency curve from the BMRC curve decreases and then increases. When θ increases, the overall change of separation efficiency curve is small. The parameter optimization scheme was obtained using response surface methodology. The research results provide reference for improving the structure of respirable dust separator in coal mine, and further promote the development of accurate monitoring technology for respirable dust.