The tube bundle of the heating water heat exchanger for petrochemical atmospheric and vacuum residue suffers from severe corrosion
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The image below shows the tube bundle of the heating water heat exchanger for vacuum distillation residue in the petrochemical industry. The model is YB1200-435-25/25-4, with the tube bundle made of 10# steel. The operating condition is that the tube side contains heating water, while the shell side contains residue oil ； The operating temperature is 95 degrees in the tube side and 132 degrees in the shell side ； The pressure in the tube side is 0.65 MPa, and that in the shell side is 1.04 MPa. This tube bundle has been in use for nearly 2 years; due to corrosion of the residue oil tube bundle, the outer wall of the tubes corroded as well, resulting in a service life of less than 4 years. Residue has a complex composition, containing various organic and inorganic compounds, including naphthenic acids, sulfides, chlorides, etc. Under certain conditions, these components can cause corrosion in metal equipment.
Under the conditions you have described, corrosive compounds such as naphthenic acids, sulfides, and chlorides present in the residue are the main causes of corrosion in the tube bundles of heat exchangers used for heating water in petrochemical plants. Since these corrosive components are more likely to erode metals under high temperatures and certain pressures, and especially since 10# steel is a commonly used material with weak corrosion resistance, this may be the key factor contributing to severe corrosion of the outer wall of the tube bundle and a reduced service life. Methods to solve this problem include: 1. Replacing the tube bundle material: More corrosion-resistant materials such as stainless steel or duplex steel can be considered. 2. Add an anti-corrosion coating: Apply an anti-corrosion coating to the outer wall of the tube bundle to reduce direct contact. 3. Optimize operating conditions: reduce operating temperature and pressure to minimize the corrosion rate as much as possible. 4. Regular maintenance and inspection: Conduct regular maintenance and inspection of the tube bundles to detect and address corrosion issues promptly, thereby preventing the spread of corrosion. 5. Use corrosion inhibitors: Add corrosion inhibitors to the residue to reduce its corrosive effect on metals. It is recommended to work with professional chemical treatment and materials engineers to conduct detailed analysis and material selection, in order to ensure the long-term stable operation of the heat exchanger. .