Study On Centrifugal Classification Flow Characteristics Of Sepiolite And Device Design

Sepiolite is one of the most widely used non-metallic mineral materials in the world.With the development of ultrafine particle production technology,the research and development and application of sepiolite ultrafine powder has entered a new stage,so the research and development performance is stable and reliable.High-precision sepiolite classification equipment can widely promote the development of China's sepiolite industry.In this paper,through the addition of internal and external double-walled mesh screens in the traditional centrifugal classification device,the particle classification under the coupling effect of centrifugation and screening is achieved,and the auxiliary method of negative pressure adsorption and Bernoulli effect are introduced to enhance the classification effect.The mechanical structure of sepiolite centrifugal classification device and the structural design of key parts,and the in-depth study of the two-phase flow characteristics and particle sieving mechanism of the flow field in the equipment under different process parameters,revealing the movement law of fluid particles under different parameters.The research ideas and research contents are as follows:(1)Detection of sepiolite mineral powder particle characteristics.The mineral powder comprehensive performance tester,scanning electron microscope,laser particle size analyzer,Stormer viscometer and other instruments are used to detect the physical parameters such as density,viscosity,compressibility,morphology,particle size distribution and other physical parameters of sepiolite particles.The numerical simulation and result test of the paper provide data support.(2)Theoretic research and device design of sepiolite centrifugal classification.Based on the basic theory of dynamics under the coupling of centrifugation,screening and negative pressure adsorption at mesoscopic scale,and based on the experience and test data in the vertical spiral centrifuge,the numerical calculation of the technical parameters of the design prototype was achieved,and the completion was completed.Basic theoretical research and overall structure design of sepiolite centrifugal classification device.(3)Numerical simulation of the flow of sepiolite particles in the classification zone at mesoscopic scale.Based on the gas-solid two-phase kinetic theory,combined with the centrifugal classification technology,screening technology and negative pressure adsorption method research,the principle prototype segmentation model andreal domain model were established.Realize the meshing and assembly of the segmentation model,through the FVM method for the sea bubble in the centrifugal coupling flow field at 300,500r/min,drum speed 200,400r/min,drum speed 200,400r/min,jet velocity 5,10,15,20m/s The flow characteristics of stone particles are calculated,and a numerical simulation analysis method considering particle size,centrifugal rotation,screen screening and jet flow is proposed,and the movement of sepiolite powder particles is numerically analyzed and analyzed using UDF The definition of particle characteristics and viscous boundaries is discussed.(4)Experimental study of sepiolite centrifugal classification.The centrifugal classification experimental platform of sepiolite powder was built,and the classification tests under different rotating speeds of drum and screen and different jet speeds were carried out to obtain the best matching speed and classification speed for the classification effect;for the classification of the device under different process parameters The performance is checked to verify whether it meets the production requirements.In the last section,the simulation results are compared and analyzed.Theoretical analysis,numerical simulation and experimental results show that the new classification device developed by this paper that combines centrifugal force field classification,screening and negative pressure adsorption has the advantages of high classification accuracy,fast classification speed,small screen impact and convenient adjustment It is of great significance to the engineering application of sepiolite ore powder and the expansion of production,and it can increase the application range and product added value of sepiolite ore powder with rich reserves in Xiangtan,Hunan.