Slagging resistance mechanism of precursor ceramic coating for solid fuel-fired boilers

Abstract

Slag formation on the heating surface in solid fuel-fired boilers is a common problem. In this paper, with polysilazane used as the precursor, three different ceramic coatings were prepared by adding hexagonal boron nitride (h-BN), ZrO2, and Al2O3 inert fillers. The coatings were applied to a TP347 substrate by the Czochralski method. The spreading and solidification experiments of the molten ash were performed and matched with numerical simulation. The results show that compared with the steel sheet, the molten ash has a large contact angle on the coating, a small spreading coefficient and the same spreading time, indicating that the coating has the slagging resistance property. The coating with the addition of h-BN has better slagging resistance properties than the other two coatings. The numerical simulation results are consistent with the experimental results.