Analysis of Corrosion and Leakage Causes of Membrane Electrolyser Frame Gasket
Membrane Electrolyzer is mainly composed of bipolar components, cathode and anode distribution tubes, cathode and anode gaskets and PTFE circulating hoses, etc. Membrane Electrolyzer sealing is achieved by fastening 16 tie rod bolts. Since the plant was put into production, the main problems of Membrane Electrolyzer were leakage of Membrane Electrolyser Frame Gasket and corrosion of repolarization components, which seriously affected the long-term economic operation of Membrane Electrolyzer.
Membrane Electrolyzer process characteristics and gasket leakage
When Membrane Electrolyzer is running, the anode is slightly negative pressure (-400~-200Pa), and the cathode is slightly positive pressure (2000Pa). The Membrane Electrolyzer closely adheres to the active electrode net of the anode due to the pressure difference between the anode and the cathode. The negative pressure of the anode is maintained and adjusted by the blower connected to the gas phase header of the electrolysis cell, and the positive pressure of the cathode is formed by the gas produced by electrolysis. The liquid phase of the cathode and anode is maintained by two high-level tanks to maintain a constant flow and level difference, so Membrane Electrolyzer can realize natural circulation, and at the same time, due to the low operating pressure, the safety is very high.
Leakage phenomenon of Membrane Electrolyser Frame Gasket: First, the four corners of the sealing surface of the electrolytic cell leaked locally; second, the gasket produced obvious leakage in the middle of the bottom of the sealing surface of the electrolytic cell.
Cause Analysis of Leakage and Corrosion of Membrane Electrolyser Frame Gasket
1. The sealing surface is partially deformed and has depressions. The sealing elasticity of Membrane Electrolyser Frame Gasket is not enough to compensate for the depression area, causing electrolyte leakage and corroding the carbon steel frame part.
2. There is crevice corrosion on the anode sealing surface of the bipolar element. Due to poor local sealing between the Membrane Electrolyser Frame Gasket and the titanium surface, a tiny gap of 0.025~0.10mm will be formed. The electrolytic brine medium containing free chlorine stagnates in the gap, resulting in Crevice corrosion.