In order to investigate the effect of particle gradation on the flow field of the feeding pipe in a classifier

the computational fluid dynamics method was applied in the study of gas-solids two-phase flow field in the feeding pipe.After the model was verified

the effects of gas velocity

feeding concentration

particle gradation and density on the pressure difference of inlet and outlet

particle concentration distribution and dispersion were analyzed.The results showed that the pressure difference of inlet and outlet increased with increasing large size particle content of gradation.When gradation was with a high content of small size particle

concentration distribution was uniform and particle dispersion was good.The change of gas velocity

feeding concentration and particle density had less influence on particle dimensionless concentration distribution and dispersion.The operation parameters had significant effects on gradation with a high content of large size particle.With the increase of gas velocity

particle dimensionless concentration decreased

concentration non-uniformity decreased

and particle dispersion became better. With the increase of feeding concentration

concentration non-uniformity increased

and particle dispersion became worse.With the increase of particle density

concentration non-uniformity decreased

and particle dispersion became better.The dividing line between high and low dimensionless average concentration in the vertical section of the axial feeding pipe was Z=0.5 m

and it basically unchanged with the change of particle gradation and operation parameters.