Study On The Influence And Regulation Of Air Column On The Graded Flow Field Of Hydrocyclone

With the increasing scarcity of mineral resources,people’s requirements for the performance of mineral processing equipment gradually increased,hydrocyclone as a high-efficiency mineral processing equipment is therefore favored by a wide range of researchers.Most studies show that the existence of air column is not conducive to the classification of hydrocyclone,so the problem of how to eliminate the air column in hydrocyclone has become one of the hot spots of research in recent years.In this paper,from the basic equation of fluid rotational motion inside the hydrocyclone,the formation principle of air column is elucidated through the derivation of Bernoulli’s equation.According to the formation principle of air column,a water-sealed hydrocyclone without air column is designed,and CFD numerical simulation technology is used to simulate the internal flow field of two types of cyclones with and without air column,and the mechanism of the influence of air column on the graded flow field of hydrocyclone is investigated.The simulation results show that:(1)after eliminating the air column,the static pressure value and pressure gradient in the internal flow field of hydrocyclone increase,which means that more static pressure energy in the flow field is converted into kinetic energy,which is more favorable to the classification of solid particles.(2)After eliminating the air column,the tangential velocity of the fluid in the semi-free vortex area of the hydrocyclone is greater,resulting in a stronger centrifugal force field,which is favorable to the classification of coarse and fine particles.(3)After eliminating the air column,the axial velocity distribution of hydrocyclone is more uniform and the residence time of solid particles in the flow field is longer,which is favorable to the classification of coarse and fine particles.(4)After eliminating the air column,the radial oscillation amplitude and velocity of the fluid in the hydrocyclone are smaller,which means the flow field is more stable and favorable to the classification of solid particles.(5)The strong turbulence in the flow field of hydrocyclone is mainly concentrated in the air column area,and after eliminating the air column,the turbulence intensity in the flow field is obviously reduced,which indicates that the air column will seriously disturb the stability of the flow field.(6)After eliminating the air column,the mixing degree of coarse and fine particles in the flow field of hydrocyclone is obviously reduced,and the classification efficiency of various particle sizes is higher.Finally,the paper verifies the simulation results through experiments and analyzes the feasibility of the designed new hydrocyclone structure.The experimental results show that the water-sealed hydrocyclone designed in this paper can completely eliminate the air column in the flow field and achieve the purpose of improving the classification efficiency of hydrocyclone,which is consistent with the simulation results.