Determination of Liquid Residence Time Characteristics in Spinning Disk Reactors via a Computational Approach

Residence time distribution (RTD) is an essential hydrodynamic prerequisite for the appropriate modeling of reactors. Our previous study designed a spinning disk reactor (SDR) for intensifying photochemical processes with disk configurations of elliptic-cylindrical spoilers (ES) and cylindrical spoilers (CS). Herein, RTD of the tailored SDRs was numerically studied using a pulse input method after verification with experimentally measured RTD curves in the previous literature. Mean residence time (tm) and dimensionless variance (σθ2) of the SDRs were in ranges of 0.29–1.43 s and 0.02–0.15, respectively. tm and σθ2 were higher in the SDR with ES and CS than in the SDR with a flat disk. The nonideal flow behavior was assessed through tanks-in-series (TIS) and axial dispersion models. TIS (n) and Peclet numbers (Pe) were, respectively, in ranges of 10–70 and 10–150 for the SDR with spoilers, indicating a departure tendency from plug flow. Finally, based on the simulation results, correlations of n and Pe relative to physical properties and operating parameters were established with deviations less than ±20%.