Abstract
Substances adhering to the inner walls of a boiler and piping were magnetically removed and recovered by applying controlled magnetic field with the aid of magnets attached to the outside of the piping while the boiler was in operation. The compositions, product phases, magnetic characteristics, and so on of the substances adhering to the piping were measured by using fluorescent X-ray spectrographic analysis, X-ray diffraction, and a vibrating samples magnetometer. As a result, it was found that the major constituent of the substances was Fe3O4, with which compounds of substances such as Zn, Cu, and Si has coagulated. Comparison of the cases in which a magnet was and was not used explicitly revealed that the amount of substances removed increased 4 times 2 months later in the former case. In a test conducted during the period from December to April, in which a magnetic remover and recoverer were installed on a boiler on site, the results showed almost the same tendency as those seen in the laboratory experiment.
