Optimization And Simulation Of The Process For Microcrystalline Nanometer Iron-based Catalyst

Iron-based catalyst is a chemical material with Fe₃O₄ as the main component and adding a small amount of K₂O,Al₂O₃ and other oxides.It has the advantages of high strength,good antiviral activity and wide raw material source.It is widely applied in Fischer-Tropsch synthesis and synthetic ammonia process.The traditional iron-based catalyst is prepared by melting method.The raw materials are melted by high temperature,rapidly solidified,broken,milled,sieved,developed and so on.It has the disadvantages of the complicated process,th short life of the cooling tank and composition segregation.which seriously restricts the conversion efficiency of iron-based catalyst.Therefore,the development of a suitable high temperature,high viscosity inorganic nonmetallic gas atomization device has become the key to realize the technological innovation of iron-based catalyst preparation,which has important academic value and broad application significance.Based on the analysis of the theory of aerosol forming and the physical and chemical properties of Fe-based catalysts,the flow characteristics of the two-phase flow of gas-liquid are explored.By studying the mathematical model of aerosol forming,the inorganic nonmetallic oxide Aerosolization mechanism,the structure of the atomizer was optimized.And the influence of the atomizer structure and the atomization flow field was analyzed by Fluent numerical simulation software.In order to optimize the process of atomization and milling of iron-based catalyst,the structure and size of the atomizer are optimized on the basis of studying the atomization mechanism.The use of restricted girth structure effectively improve the atomization effect and reduce the splash phenomenon and clogging.Liquid and gas outlets with the round corner transition reduce the energy consumption.Atomizer which use free fall method of work improves the efficiency and powder spherical shape and reduces the energy consumption.In this paper the influence of atomized nozzle structure on the flow state of atomized fluid is explored by numerical simulation method.The characteristics of airflow and flow in each channel of double nozzle are also studied.The results show that the main role of the upper atomizer is to suppress the return flow,avoid splashing and give diversion and protection to the liquid.Lower atomizer bear the function of atomization and milling mainly.The air flow distribution with double atomizer is uniform and the velocity of the atomized area is obviously higher than that of the single layer atomizer,which effectively improves the atomization effect.In order to improve the crushing effect of high temperature liquid flow,we design the air chamber baffle for the new atomizer and simulates the airflow velocity and distribution of the air chamber baffle.The results show that the existence of the gas chamber baffle increases the gas velocity and pressure,the faster the liquid is broken,the atomization effect is obvious,and the height of the inner cavity of the atomizer is studied.The actual result is that the atomizer Protrusion structure height of 5mm atomization effect is the best.In this paper,the angle between the upper atomizer and the lower atomizer,the angle of the outlet of the double atomizer,the diameter of the center hole of the lower atomizer,influence of intake pressure of main sprayer on flow field distribution in atomization process.The results show that the study found that when the upper atomizer outlet angle of 30°,the lower atomizer outlet angle of 60°,the lower atomizer assembly distance is located in the catheter outlet distancing 5mm to the top,the lower atomizer center hole diameter of is 50mm the atomization effect is best.the appropriate increase to pressure of the two-layer atomizer inlet within a certain range can effectively improve the atomization effect,but the pressure should not be too large,which will increase performance requirements of the nebulizer higher and the gas consumption.