In the atmospheric and vacuum distillation units of the petrochemical industry, the tube bundles of the steam generators used in the fourth stage of oil washing suffer severe corrosion
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The image below shows the tube bank of the oil washing steam generator in the atmospheric and vacuum distillation unit of the petrochemical industry. Model: FA1200-85-25-8, Material: 10# steel. This tube bundle has been in operation for nearly two years. Operating conditions: Shell side: deionized water, temperature 108°C, pressure 0.902 MPa. Tube side: medium, four-line oil washing with reduction, temperature 293°C, pressure 0.817 MPa. During maintenance, when the heat exchanger was opened, it was found that the metal in the shell side was severely corroded.
Regarding the corrosion issue of the tube bundle shell in the four-line reduction oil washing steam generator, possible causes include: 1. **Corrosivity of desalinated water**: Although the corrosivity of desalinated water is relatively low, it can still have an impact on 10# steel under high temperature and pressure conditions. 2. **Temperature and pressure**: High temperature and pressure conditions accelerate the oxidation and corrosion reactions of metals. 3. **Flow rate**: If the flow rate in the shell side is low, it may lead to poor local water flow, thereby causing corrosion. 4. **Water quality issues**: Desalinated water may contain residual ions or impurities, increasing the risk of corrosion. 5. **Maintenance and Inspection**: Failing to clean deposits or dirt in a timely manner can also lead to localized corrosion. It is recommended to conduct a detailed corrosion assessment, considering the use of corrosion-resistant materials or the improvement of operating conditions to extend the equipment’s service life. .