Analysis by cfd tool to evaluate the performance of a tubular electrochemical flow reactor with rotating anode

In the present work, Computational Fluid Dynamics (CFD) analysis was used to evaluate the dispersion and visualize the velocity and vorticity field behavior along of a tubular electrochemical reactor in laminar flow regime, with a low speed-rotating anode operated. Five different reactor configurations to evaluate the performance of the reactor with rotating anode (cases C and D) in comparison with the reactor with static electrodes (cases A, B and E) were tested. Configurations A, E and C have three gaskets between the cathode and the anode. In the case E, the anode area was doubled to evaluate the effect on the reactor performance. At the same configuration, with and without gaskets (A versus C and B versus D) a substantial increase in the axial velocity (i.e. a reduction in the backwater), cell Reynolds number and spatial vorticity was achieved operating the reactor with the anode in rotation instead of static one. The improvement with the rotating anode could be related to the reduction of the axial flow barrier and disturbs on the fluid or chaotic flows induced by the motion of the rotating helical electrode. However, the percentage of negative velocities (backmixing) produced with the rotating anode, increased. The reactor with configuration E (static electrode and largest electrode area) showed the highest percentage of low axial velocities. On the other hand, in the flow electrochemical reactor with rotating anode, the backwater (low axial velocities ±0.0002 m/s), were reduced significantly. The vorticity and the cell Reynolds number were evaluated and both increased considerably when the anode was rotated during the electrochemical process, with and without gaskets. However, the percentage of negative velocities produced with the rotating electrode, increased until values higher than 55.25%.