| At present,the use of small hydrocyclones to separate fine particles has attracted more and more attention,but they are often limited to conventional shapes or specific inlet and outlet sizes,which lead to poor separation performance.This paper proposes a new type of parabolic wall hydrocyclon e(fx10.0),through the design,CFD-DEM,and the three links of testing to analyze the different particle size of the parabolic wall cyclone and the traditional conical wall.With different inlet flow rates and different inlet concentrations,the sand outl et recovery rate,concentration ratio,and particle filtration thorough time are three main separation indicators,and the internal flow field and particle trajectory are analyzed.Since the separation performance of the parabolic wall cyclone is better than that of the traditional cyclone,two orthogonal selections of the parabolic wall cyclone are carried out,and the following conclusions are drawn:(1)The separation performance index of the parabolic wall cyclone is stronger than that of the conical wall cyclone under different particle diameters at different flow rates and concentrations.When the inlet flow rate is 1.5m/s,the recovery rate of the sedimentation port is improved.13.53%,the concentration ratio increased by 0.54,and the particle filtration thorough time increased by 0.6s,which is the moment when the separation performance is improved the most.,The separation performance of the two cyclones is not much different.The grit recovery rate of the two hydrocyclones is proportional to the size of the particle size,and the grit recovery rate of the new parabolic wall hydrocyclone is always higher than The grit recovery rate of the traditional parabolic wall hydrocyclone,where the grit recovery rate gap is 14.53% at35 m,the concentration ratio gap is 0.56,and the particle filtration time is 0.6s faster.The error of the grit recovery rate of the digital model and the test is within 15%,which is caused by the test temperature,the condition is not completely consistent with the digital model,and the complexity of the rotating flow.(2)Under the conditions with the largest separation performance gap,the pressure gradient of the new parabolic wall hydrocyclone is more obvious,fast,and efficient.The particles with a longer residence tim e in the cone section are mostly discharged from the grit,but the wear is also Big.Compared with the traditional conical wall cyclone,the new parabolic wall hydrocyclone has a significantly higher tangential velocity and a more obvious velocity gradient;the axial velocity is also greater,which is more conducive to the rapid separation of sand particles and improves the separation efficiency;The radial velocity is also greater,so when the distribution law is basically the same and the distribution is centered symmetrically,the radial drag force is greater,which is more helpful for small particles to enter the internal swirling flow,and minimizes the phenomenon of overflow and runaway..(3)It is convenient and feasible to manufacture various new h ydrocyclones through 3D printing,and can be analyzed by digital simulation.While saving design costs,time and versatility are improved,and separation efficiency is well improved.(4)In the first round of orthogonal selection,the structural factors of the parabolic wall hydrocyclone with better performance are selected for the first time through the digital model,and the diameter of the inlet and outlet,the diameter of the grit port and the diameter of the overflow are selected as the second round of positive Hand over selection factors.(5)The second round of orthogonal selection results show that the largest impact on the separation effect of the parabolic wall hydrocyclone is the inlet diameter B,followed by the grit port diameter A,and the over flow port diameter C again.The best selection grit port diameter: 1.8mm,inlet diameter: 2.3mm,overflow port diameter:3.1mm.The results of digital model selection and test selection are consistent. |
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