抄録
Four ash samples were taken from the HRSG of a ferrosilicon furnace in western China, which suffered serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were utilized to analyze the ash samples. The results show that low melting point salt and composite salts are absorbed to the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas are absorbed to the slag surface to form thicker slag. Low melting point composite salts are absorbed to the evaporator tube walls in aerosol form. With the deposition of low melting point composite salts, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the larger iron-rich slag particles are easy to deposit on tube walls and fin surfaces, which are advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that are easy to be absorbed by other particles or tube walls, which facilitate the slagging and fouling processes.
