Residence time distribution in multiorifice baffled tubes: A numerical study

© 2016 Institution of Chemical EngineersThe fluid flow and the transport of species in an intensified topology of oscillatory baffled reactors is analyzed here by means of CFD. The classic configuration with equidistant single orifice plate baffles has been replaced by multiple-orifice disks, of the same open cross-sectional area. The flow through these disks generates an array of parallel jets downstream and upstream, exhibiting various swirl structures that increase the radial mixing. Time-dependent flow patterns are presented here for configurations of disks with 1, 3, 7, 19 and 43 orifices. The evaluation of their mixing performance has been accomplished by injecting a pulse of a tracer, for a constant oscillatory Reynolds number of Reo = 800. The concentration-time profile of the tracer throughout the reactor was analyzed and an axial dispersion coefficient was derived on the basis of a 1D plug flow with dispersion model. It was clear that the quality of plug flow increased with increasing number of holes. Pressure-drop was reported by means of Fanning friction factor and power density dissipation.