Optimization And Research Of The Nozzle In Fixed Bed Reactor

Fixed bed reactors are mostly used to achieve multiphase reactions,where the atomization system is the main component that affects the reaction rate,catalyst utilization rate and productive rate.Due to the complexity of the atomization,the flow characteristics and atomization characteristics of the nozzle have not been standardized yet.This has gradually become the difficulty of its structure design.First,the experimental and numerical simulation methods are combined to explore the pressure swirl nozzle designed for the pure liquid-phase feeding conditions.The relationship between flow rate and pressure drop,atomization particle size,atomization distribution index and atomization Angle is studied.What's more,the empirical formula for calculating the nozzle flow is established by using MATLAB software.On this basis,the structure is numerically simulated using RNG k-? model,and the simulation results are in good agreement with the experimental results.In addition,the pneumatic swirl nozzle for the multi-phase feeding condition is investigated.The rule of the pressure drop,particle size and atomization angle are explored under the constant gas-liquid ratio,the constant gas flow or the constant liquid flow.The RNG k-? model and Euler-Euler model are used to simulate the structure.It is found that the larger gas velocity,the larger Mach number,and the relative change in gas density cannot be ignored,so that the gas can no longer be considered as an incompressible flow.At this time,the numerical simulation result and the experimental result are greatly deviated.The model has limitations.Finally,the main structure parameters are changed for the future structural optimization.The optimized structure can effectively solve the industrial problems such as coarse atomized particle size,high droplet velocity to the catalyst bed and uneven liquid-phase distribution.