Investigation On Carbon-in-Ash In-Situ Measuring Technique Without Sampling

This paper applied a new method to measure the unburned carbon content in fly ash of pulverized coal-fired boiler on line, and developed a microwave analyzer of flue type to determine the carbon content of fly ash. The analyzer of flue type can avoid the deficiencies caused by the conventional analyzer with sampling tube.The paper discussed a fundamental theory that microwave can be used to determine the carbon content, introduced a certain relationship between the attenuation of microwave and carbon content in fly ash and designed a microwave measuring system. In addition, a reduced experimental apparatus was designed hi proportional to the actual size of the flue in power plant, and an applied program needed in the measuring system was developed. Furthermore, a large amount of experimental work was carried out and the feasibility of the measuring system was proved.A theoretical model on the concentration of fly ash was proposed. The concentration of fly ash was considered as the function of several parameters of the boiler in power plant. By acquiring these parameters, the paper can compute the concentration of fly ash which provided the theoretical basis of the measuring system.This paper also discussed the installation and calibration of the system.