Abstract
In long-term operation of a fluidized bed RDF combustion boiler, gas phase chlorine compounds are exhausted together with the other flue gas, and solid and liquid phase chlorine compounds with alkali compounds are circulated with bed particles, which are deposited to the heat exchanger tube, and can possibly cause the tube corrosion. The objective in this study is to clear the mechanism of the corrosion with alkali-chlorine compounds when the erosion results from collision of bed particles. The degree of corrosion was measured by the weight loss of a small sample of heat exchanger material, surface observation of the SEM/EDX, and the acid solubility. The results revealed that the tube corrosion is more likely to progress when weak erosion occurs in the ambient air conditions. Stainless steel like SUS310S is more preceded than nichrome. Thermodynamic equilibrium calculation results suggested that Ca3Fe2Si3O12 and CaCr2O4 are possible calcium components as a cause of heat exchanger tube corrosion.
