Experimental And CFD Study On Performance And Flow Field Of Cascade-ring Aerodynamic Dust Collector

Cascade-ring aerodynamic dust collector is a type of inertial separator,which can be widely used in boiler,tobacco,cement,metallurgy,electric power,chemical industry and other fields because of its small volume,good separation performance and convenient installation.Due to its flexible process layout,the separator can be linked with natural gas pipelines directly,which means it is theoretically appropriate to apply the separator to natural gas pipelines.Thus,this paper mainly studies the separation performance in the case of natural gas dedusting.However,the detailed structure and internal geometrical dimensions of the cascade-ring aerodynamic dust collector remain unclear yet,and the effects of structure parameters and flow parameters on its separation performance lack of systematic research so far.Studies on the separation performance of cascade-ring aerodynamic dust collector herein were conducted by means of numerical simulation and experiments.ANSYS Fluent 18.0 was utilized in numerical simulation to simulate the gas flow field and analyze the influence of seven factors(interval distance d,dislocation of rings b,loop height h,number of rings n,inlet gas velocity v,ratio of exhaust gas φ,particle concentration c)on separation performance of the separator.In that case,structure parameters for optimum separation performance can be deduced and determined.On the basis of these,a cascade-ring aerodynamic separation system was set up.The separation efficiency was measured by weighing method.Separation performance of the separator under different operating conditions was analyzed and the efficiency and pressure drop obtained by experiments and simulation were compared.The results show that increasing the interval distance d makes the separation efficiency increase at first and then decrease,and the pressure drop reduce;increasing the dislocation of rings b decreases the separation efficiency and hardly has effects on the pressure drop;increasing the loop height h makes the separation efficiency increase at first and then decrease,and the pressure drop reduce;increasing the number of rings n doesn’t improve the separation efficiency and brings about apparent increase of the pressure drop;with the increase of the inlet gas velocity,the separation efficiency increases and so does the pressure drop;increasing the ratio of exhaust gas is an effective way to improve the separation performance for the reason of higher separation efficiency with lower pressure drop;increasing the particle concentration decreases the separation efficiency and hardly has effects on the pressure drop.Structure with b=1mm,h=5 mm,n=20 comes with the best separation performance.In addition,interval distance corresponding to optimum separation performance depends on the ratio of exhaust gas,so,to consider comprehensively,3 to 8 mm shall be the best range.Effects of different operating conditions on separation performance deduced from experiments are consistent with simulation.Finally,the interval distance is further studied by means of numerical simulation in order to offer a reference for the follow-up optimization.The results show that decreasing the interval distance to 3mm can effectively improve the separation efficiency of particles with relatively larger diameters as well as the pressure drop.