Steven A. Matthes

Field Test of High-Temperature Corrosion Sensors in a Waste-to-Energy Plant

Abstract Electrochemical probes originally designed for use in aqueous environments were shown to measure corrosion rates in a high-temperature gaseous environment where electrolyte consisted of conductive ashes and liquid slag. The field trial of the probes was conducted over a five-month period to monitor fireside corrosion in a waste-to-energy (WTE) plant. The three-electrode air-cooled corrosion sensors, each including a thermocouple to monitor sensor temperature, were installed in four different ports at approximately the same level of the WTE boiler. A total of 12 sensors were tested: six with electrodes using the carbon steel boiler tube material and six using the nickel-chromium alloy used for weld overlays for the electrodes. Corrosion rates and temperatures of the sensors were monitored continuously throughout the trial. Metallographic measurements of sensor thickness loss were used to calibrate the electrochemical corrosion rates. Air cooling of the sensors was found to be necessary to bring th...