Failure Analysis of Bed Coil Tube in an Atmospheric Fluidized Bed Combustion Boiler

The Atmospheric Fluidized Bed Combustion Boilers have advantages as compared to conventional coal fired boilers in respect of heat transfer, SOx, NOx, emissions and efficiency. In the present study, the failure analysis of bed coil tube, used in atmospheric fluidized bed combustor was studied. The failure studies included physical, chemical and metallurgical analysis and the results analyzed reveal that the failure is typically due to caustic gouging. The cause of failure has further been substantiated using scanning electron microscopy with energy dispersive X-ray analysis as well as X-ray diffraction analysis.