Abstract
Boilers are used to generate steam in many field such as building and thermal power generation. Substances precipitated from the circulating water through boilers and their piping during the course of evaporation such as sludge take place the obstruction to the flow and the lowering of the thermal efficiency of steam. New method of the removal and recovery of substances adhered to the pipe walls is described in this study in which the Lorentz force generated by equipping a magnet at the outer side of piping and controlling magnetic field is given. From fluorescent X-ray spectrographic analysis, X-ray diffraction, and magnetic measurement, the major component of the substances adhered to the pipe walls was identified as containing a mixed the magnetic Fe3O4 compounds of Zn, Cu and Si. Experimental results show that the sludge is more easily removed in the case of the magnet being equipped than in the other case. Total amount of removed scales by the magnet after two months has resulted in four times in weight compared with the case without the magnet.
