Design Of Venturi Ejector For Sepiolite Powder And Analysis Of Its Flow Characteristics

The research and development of sepiolite powder jet classification equipment can effectively increase the added value and the range of utilization for the sepiolite resources industry with abundant reserves and obvious advantages in Hunan Province.The venturi injector is a key component in the realization of the mixture of slag and gas in the sepiolite powder jet classifier.Based on the venturi effect this dissertation has been studied the optimization design of the venturi injector for sepiolite powder,and mainly discussed the test of sepiolite powder characteristics,the design of venturi ejector,the optimization of structural parameters and the flow characteristics of sepiolite powder in the venturi ejector:(1)The test of sepiolite powder characteristics.The physical characteristics and mechanical characteristics of sepiolite powder used in this dissertation is obtained by building an experimental platform with microscopic method,volumetric method and direct shear method to provide data for subsequent simulation analysis.(2)The theoretical analysis and the structural design of venturi ejector.Firstly,the working principle,working efficiency and various structural design methods of the venturi ejector is analyzed;Then the theoretical impulse coefficient of the venturi injector is calculated by the gas dynamic function method;Finally,the geometry structurewe of venturi injector is initially determined according to the relevant empirical formula.(3)The structural parameter optimization of venturi injector.For the problem that the inefficiency of venturi injector,the influence of different structural parameters on the working efficiency is analyzed by using single factor control variable method;and then the orthogonal design method is used to optimize the structural parameters of the venturi injector with the working efficiency as the assessment indicators;Finally,the optimal structural parameters is obtained by the range and variance analysis and at the same time the physical model is provided for the subsequent simulation analysis.(4)The simulation analysis of flow characteristics of sepiolite powder in venturi injector.Aiming at the complicated flow of sepiolite powder in the venturi injector,the DPM model is used to simulate the internal flow of venturi injector in different states from four aspects: pressure,velocity,particle trajectory and turbulence kinetic energy.(5)The PIV experimental analysis of sepiolite powder in venturi ejector.The PIV experimental platform is constructed to analyze the interior flow of sepiolite powder in different conditions,and the interior flow law will be obtained by comparing the simulation results with the simulation results.The theoretical analysis and the experimental results show that the venturi injector designed in this paper can not only realize the rapid and effective mixing of the mineral powder and gaseous fluid,but also improve the working efficiency of venturi injector by optimizing the structural parameters.This is of great significance for the classification of future sepiolite powder can increase the added value and the range of utilization of sepiolite products.