Electrochemical corrosion of electrode equipment in food processing device using FEF technology

During the process of treating food with pulsed electric field (PEF), the pulsed electric current passes through the electrode-liquid interface inside the treatment chamber. This induces electrochemical reactions that corrode electrode and influence the food security and the facility operation. We studied the corrosion mechanism of electrodes during PEF processes through accelerated corrosion tests, and investigated the influences of the applied voltage, pulse width and solution conductivity on the electrode corrosion, which were scaled by the ion concentration of the electrode material in the sample solution. The relationship between the corrosion rate and the treatment time was also obtained. The results show that the conventional circuit model can explain the electrode corrosion under PEF. The ion concentration increases from 0.466 μg/L to 2.085 μg/L when the applied voltage increased from 16.7 kV/cm to 41.7 kV/cm, from 0.4 μg/L to 4.855 μg/L when the pulse width increases from 5 μs to 20 μs, and from 0.8 μg/L to 43.4 μg/L when the solution conductivity increases from 1 μS/cm to 600 μS/cm. The corrosion of the electrode starts from the chamfer edge and gradually develops to the center area. Oxidizing the corroded electrode in the air can slow down the corrosion. We also proposed some other anti-corrosion measures based on the experimental results.