Numerical Simulation Of Flow And Mass Transfer In Tubular Electrochemical Reactor For Organic Wastewater Treatment

Tubular electrochemical reactor is an important kind of reactors for organic wastewater treatment. Computational fluid dynamics (CFD) is a new subject combining the numerical simulation and Fluid mechanics. The fluid flow and reaction can be studied by the technology effectively with the help of computers.This study tried to model a tubular electrochemical reactor and characterize the flow and mass transfer inside the reactor using a CFD software-FLUENT. The simulation obtained the velocity field, the inside velocity distribution, the velocity vector field. The generation of eddy and circumfluence were observed; the distribution of velocity is uniform; the velocity gradient mainly existed on the surface of the anode. With the tool of the turbulent intensity, the diagram of the turbulence inside the reactor was showed. It indicated the level of the commixture was high in the bulk of liquor inside the reactor. The residence time distribution obtained by the simulation was evaluated; the result (9.47s) had a big difference with ideal value (14.75s). The details of mass transfer in the reactor were simulated and analyzed. The mass transfer model was made. According to the related operation conditions, the boundary conditions and the initial conditions were determined. The mass-transfer dimensionless equation (Sh=0.127Re0.67Sc1/3) was obtained, and the distribution of the local sherwood number along the anode axis showed the mass transfer ability was highest in the first Part of the compartment, and then decreased to a convergence value, at the last had a small jump up to a higher value. Post-processing variable (limited current density) was developed for the first time. The elaborate diagram of the limited current density over the surface of the anode showed the distribution was uneven very much. Two other kinds of tubular reactor were offered. Based on the prior work, the simulation for the two other kinds of tubular reactor was executed. The results were compared and showed the mass transfer rate increased highly, Sherwood number raised from 202-431 to 1228-3143.