Numerical Investigation Of Critical Volume Flow Rate In A Class Of Micro-Reactor

The configuration of rotating conical cylinders is the basic structure of a micro-reactor called RLFR (Rotating Liquid Film Reactor). It’s used in laboratory to prepare nano-material. The gap between two cones is filled with reactant solution which is usually a viscous incompressible fluid. Experiment on precipitation of nano-sized barium sulfate in a rotating liquid film reactor has been carried out at a critical volume flow rate (CVFR), which is obtained experimentally.In this article, the CVFR has been investigated numerically based on the computational fluid dynamics technique and the Navier-Stokes equations. Detailed numerical simulation involving varying the operating parameters of the RLFR is carried out in order to investigate the impacts on the CVFR. First, the gap size of the experiment is selected to carried out the numerical simulation of the CVFR. By comparison of the numerical results and the experimental results we find that the numerical results agree well with the experimental ones. Then we expand our simulation to other operating parameters and investigate the effect of varying operating parameters on the CVFRs. These are the cases that the experiments didn’t involve. The results showed that for small Reynolds numbers (Re) the correlation of CVFR with the rotor speed Ω is obtained as Q =a*Ω2+b. And the correlation of CVFR with the viscosity of liquid v is given as Q∞1/v. Moreover, in the case of ignoring gravity, the correlation of the dimensionless CVFR with the Reynolds number (Re) is obtained as Q*=k*Re. The investigations also suggests that varying the gap size has a more remarkable effect on the CVFR than varying the rotor speed.At last, we consider the effect of the inclined angle on the CVFR, the numerical results shows that there exist a critical inclined angle. The CVFR increases with increasing the angles before the critical inclined angle is reached, and decreased after the critical inclined angle. The Critical inclined angle is independent on the viscosity of the fluid, but dependent on the rotor speed. This confirms the reasonable design of the Rotating Liquid Film Reactor.