Abstract: This paper focuses on analyzing the corrosion mechanism of evaporative heater for ammonia desulfurization. The main corrosion causes of the evaporator-heater for ammonia desulfurization are chloride ion pitting corrosion and erosion corrosion of ammonia sulfate slurry crystalline particles. By comparing and analyzing the use of 316L, ta2 and SAF 2507 in evaporative heater, the paper puts forward some suggestions for the optimization of material selection for ammonia desulfurization evaporative heater. Meanwhile, combined with the actual operation experience, measures such as changing the pH value of circulating fluid and reducing the concentration of chloride ions in circulation fluid, controlling the solid content of the slurry entering the evaporative heater and adding anti-wear bushings at the inlet of the heater tube bundle are proposed, which can effectively slow down the corrosion of ammonia sulfate slurry on the evaporative heater tube bundles.

Key words: ammonia desulphurization, ammonia sulfate circulation fluid, evaporative heater, corrosion mechanism