Thread Content
Both 316L stainless steel and duplex steel are used in distillation towers, but in different applications. 316L is commonly used in environments with mild corrosion, whereas duplex steel (such as 2205) is often used for tower shells or internals in high-chloride, high-stress environments to balance corrosion resistance and strength. 1. Application examples of 316L stainless steel: Suitable for handling dilute hydrochloric acid, dilute alkalis, saline systems, and organic solvents containing chloride ions (such as the distillation of vinyl chloride monomer). Used as the tower shell material in ethanol-water separation towers, it shows no significant corrosion after long-term operation, and its cost is lower than that of nickel-based alloys. When used for tray supports, downcomers, and other internal components of towers, surface polishing or hardening treatments can be applied to improve resistance to scaling and wear. 2. Application examples of duplex steel (such as S32205): In the desulfurization distillation columns of catalytic cracking units in refineries, it is used in the high-temperature and high-chloride areas at the bottom of the columns, providing effective protection against chloride stress corrosion cracking. In an ethylene project, duplex steel was used for the tray condenser nozzles and flange assemblies; since ordinary 316L steel suffered from frequent pitting, replacing it extended the equipment’s service life by more than three times. In the reboiler connection section of seawater desalination distillation towers, its high strength and good weldability are utilized to reduce the wall thickness and enhance the pressure-bearing capacity.