Development of a Thermal-Sprayed Coating System to Mitigate Ice Accumulation and Freezing Damage in Carbon Steel Pipes

Solidification of water in pipes is a common phenomenon. The resulting damage may be both costly and dangerous and thus warrants attention. A two-layered flame-sprayed coating, developed as a resistive heating system, was deposited on a carbon steel pipe. The feasibility of using a 50Cr-50Ni coating as a heating element on top of a conductive substrate was studied. Alumina was deposited to serve as an electrically insulating layer between the metal coating and the substrate to ensure that there was no flow of electrons from the heating element to the substrate. Continuity, homogeneity, and adhesion of the coating was qualitatively analysed by using a scanning electron microscope. The performance of the heating system was determined by measuring the ice temperature and the times required to heat and melt the solid ice that was formed within the pipe. It was found that the coating system was able to generate the heat required to melt the ice in the pipe, thus avoiding the detrimental effects on the pipe of internal liquid freezing. This suggests that the proposed novel resistive heating system can be used on an industrial scale to mitigate the detrimental effects of ice accumulation in steel and other metallic pipes.