Method and apparatus for monitoring the formation of deposits in furnaces

A method of monitoring formation of deposits caused by depositions of solid particles from a hot, dust-laden flue gas onto walls of a rectangular furnace of a boiler, wherein said walls are formed of tubes that are tightly welded together and through which a cooling medium flows, said method including the steps of:

• providing two infrared cameras that are offset by 90° relative to one another;
• detecting, over the entire surface of said walls of said furnace, the exact surface temperature with said infrared cameras via a thermal image obtained of a surface development of said furnace;
• comparing the detected exact surface temperature with the temperature of the cooling medium known at respective measurement locations, taking into consideration the thickness and the thermal conductivity of said tubes of said walls of said furnace;
• comparing individual images taken by each of said infrared cameras to form an overall development of said walls of the inner surface of said furnace;
• determining the coordinates of said deposits on said walls from said overall development;
• and
• determining the thickness of said deposits on said walls from the temperature comparison.