CFD Simulation Of Liquid-liquid Two-phase Flow In An Oscillatory Flow Reactor With Circular Ring Baffles

Oscillatory flow reactor is a new type of chemical process intensificationequipment. Vortices are generated in the reactor due to its constricted baffle geometryand periodic oscillatory condition, which provide both axial and radial mixing in thereactor, increase the interface area of immiscible two-phase, improve the residencetime distribution of dispersed phase, and achieve effective control of particle size andits distribution.In present study, a combination of computational fluid dynamics（CFD） andpopulation balance model（PBM） is applied to study the effect of oscillatory condition,baffle orifice ratio, baffle spacing and scale up of reactor diameter ontriglyceride-methanol two-phase mixing and mass transfer characteristics in anoscillatory flow reactor with circular ring baffles.The results show that, the average velocity increases linearly with the increaseoscillatory Reynolds number, both the droplet size and size distribution greatlydecrease with the increase oscillatory Reynolds number, the oscillation amplititudehas more influence on the flow filed and droplet size distribution than the oscillatoryfrequency. Established a correlation between Sauter mean diameter,d₃2, and theenergy dissipation,ε,as d₃2=1.99×10^-4ε^-0.4.The optimal baffle orifice ratio wasbetween25%and31%, the optimal baffle spacing was1.5D（D, reactor diameter）, themixing and mass transfer characteristics have scale-up effect with the increase reactordiameter.The information of effect of oscillatory condition and geometry on the two-phasemixing and mass transfer characteristics by the simulation provide a theoreticalguidance for reactor design, geometry structure improvement and scale up.