Simulation And Experimental Study On Mixing Process Of Liquid-solid Jet

With the development of industry,environmental problems caused by dust pollution have become increasingly serious.Silica powder is widely used in chemical production.Silica powder is widely used in chemical production.Silica powder is added into glycol solution to form dispersion,which is widely used in coating,rubber,leather,plastic,printing,textile and other industries,with thickening,thixotropy and other functions.A large amount of dust will be generated during the silica powder feeding process,which will cause long-term workers to form silicosis.Aiming at the phenomenon that a large amount of dust is generated by the feeding of silica powder,this topic introduces a jet pump.The negative pressure generated at the jet pump nozzle outlet can effectively suppress the dust.In order to further explore the effect of the jet pump,this paper uses Fluent software to numerically study the silica powder feeding process and the internal flow field of the jet pump.The research work in this paper mainly includes the following points:(1)Analysis of dusting mechanism of powder filler.Through the calculation of related formulas and theoretical derivation,the force of powder particles in the flow field was explored.The silica powder interacted with air during the feeding process.When the resistance of the powder particles to the airflow was greater than the floating weight,the powder particles When the force is greater than zero,dust is formed.(2)Numerical simulation of the process of dust generation from the addition of silica powder.With the help of Fluent software,the internal flow field of the feeding tank was numerically simulated,and the effect of the silica powder powder mass flow on the generation of dust was simulated.The results show that the larger the mass flow,the more dust is generated.(3)Simulation analysis of the internal flow field of the liquid-gas jet pump.The ethylene glycol solution was used as the working fluid,and the internal flow field of the liquid-gas jet pump was simulated by Fluent software,and the distribution of the speed and pressure of the internal flow field was obtained.The effects of different mass fractions of glycol solutions as working fluids on the jet performance of liquid-gas jet pumps were studied.The results show that as the mass fraction of the ethylene glycol solution increases,the viscosity of the liquid gradually increases,leading to a gradual decrease of the ejection coefficient.(4)The effects of operating parameters and structural parameters on the injection performance of the jet pump are simulated.① The effects of mixed fluid outlet pressure and working fluid inlet pressure on the performance of jet pumps were simulated.The results show that as the outlet pressure of the mixed fluid increases,the ejection coefficient gradually decreases,and even the phenomenon of backflow occurs;as the inlet pressure of the working fluid increases,the ejection coefficient gradually increases.② The effects of area ratio and nozzle distance on the performance of the jet pump were simulated.The results show that there is an optimal value for the area ratio and the optimal value is 4;there is an optimal value for the nozzle distance.The optimal nozzle distance of the model established in this paper is 70mm.(5)Experimental research on jet pump.An experimental study of the liquid-gas jet pump was performed to verify the effect of operating parameters on the performance of the jet pump.The results show that the influence of the mixed fluid outlet pressure and the working fluid inlet pressure on the performance of the jet pump tends to be consistent with the experimental results,which verifies the reliability of the model.