Numerical studies of an axial flow cyclone with ongoing removal of separated dust by suction from the settling tank

The properties and advantages of axial flow cyclones, which are increasingly used as the first stage of inlet air filtration for motor vehicle internal combustion engines, are presented. The need for research on through-flow cyclones to improve their filtration efficiency or reduce flow resistance is demonstrated. It has been shown that one of the factors that can increase the filtration efficiency of cyclones is the use of ongoing removal of dust separated from cyclones by extracting it with an additional stream. The phenomenon of dust extraction in cyclones has not yet been the subject of model studies. The authors decided to fill the gap in this area by designing a model of axial flow cyclone, in which the original solution is the use of current removal of dust by an additional stream from the cyclone's collection chamber and settling tank, where the separated dust is collected. Solutions of this type have not yet been considered in model cyclone studies. Simulation studies of the developed cyclone models with dust extraction were performed, which included the characteristics of filtration efficiency Wc = (D0), Wc = (m0) and flow resistance Delta pc = (D0), Delta pc = (m0). The obtained results were verified using experimental studies of the dust extraction cyclone available in the literature. It was shown that the model of a cyclone with dust extraction from a limited volume settling tank predicts well the cyclone characteristics Wc = (D0) in the range of higher (D0 = 8-10 m/s) inlet velocities. For lower inlet velocities, the value from the experiment is more than 16 % higher than that from model tests. Significant agreement was obtained in the course of the characteristics of filtration efficiency Wc = (m0) for larger values (m0 = 10-20 %) of the degree of suction.