CORROSION-WEAR BEHAVIOR OF IN-BED TUBES DUE TO HCI AND PARTICLES IMPACTS IN A SIMULATED BUBBLING FLUIDIZED BED
HCl对沸腾流化床燃烧器换热管腐蚀和磨损影响的研究

Heat-exchanger tubes in fluidized bed combustors (FBCs often suffer from material loss due to combined corrosion and erosion. To further understand the effect of chlorine on in-bed tube wastage, a FBC wastage simulator was used to carry out the study. The later was designed to simulate dense particle impacts on the tube bottoms with well-con- trolled parameters, and has been proven to closely reflect situation found in operation bub- bling FBCs. HCl gas was chosen to be the C1 source and was introduced into the fluidizing air with a dose of 50X Tests were performed at temperatures from ambient to 400'C with samples made of 1018 low carbon steel rods and a bed consisted of commercial SiO sand with average size of 800 pm. The wear profiles after each test was measured using a profilometer. Results showed that the presence of HCl increased the material wastage rates and the rate was significant higher at higher temperatures. The results of microstructural and chemical analysis of the wear surface and corrosion products are also reported. It is concluded that the dominating effect of HCl on the wastage rates is due to an enhanced oxidation and a reduced scale adherence.