Mechanism of ash deposition in industrial waste treatment furnaces and its control

Abstract

In incinerators and boilers using waste-derived fuels, ash deposition on the surface of heat transfer tubes, such as slugging and fouling, causes problems such as reduced power generation efficiency due to heat transfer inhibition, incinerator operation inhibition, and inhibition of boiler steam temperature and pressure increase due to chemical corrosion on the heat transfer tube surface. In this study, the melting behavior of industrial waste ash was clarified for the practical use of higher temperature and higher pressure steam conditions, and thermal spraying materials were investigated to reduce ash adhesion on the surface of the heat transfer tubes. Contact angle measurement experiments and SEM/EDX analysis were conducted using each material to investigate the ash adhesion resistance and corrosion resistance of the sprayed materials. From the contact angle measurement experiments, it can be considered that the contact angle of the developed material Ni-2 is larger than that of SUS310S under all conditions, and that ash adhesion can be suppressed or reduced. In addition, the results of SEM/EDX analysis suggest that Ni-2 can suppress the progress of chemical corrosion caused by molten ash better than SUS310S.