| 摘要 |
<p>PURPOSE:To allow highly accurate monitoring of the deterioration of thermal insulation cover by winding an optical fiber cable at an arbitrary interval while fitting tightly to the surface of an iron skin using a fixing frame and then connecting the optical fiber cable, at the opposite ends thereof, with a laser light source and a detector. CONSTITUTION:A temporary stop metal 7 is temporarily welded to the iron skin 2 of an external-combustion hot gas furnace. An optical fiber cable 1 is then laid while stapling with the metal 7. The cable 1 is wound at an interval of 1-3m such that the dome and the coupling pipe are wound densely but the straight drum part is wound coarsely. The fixing base of thermal insulation cover, i.e., an inside fixing frame 4, is then wound around the iron skin 2 thus pressing the cable 1 against the iron skin 2 by means of the metal frame 4. A stud bolt 11 is welded to the metal frame 4 and a thermal insulation member 5, a thermal insulation cover 3, and an outside fixing metal 6 are then fixed sequentially thereon and a nut 12 is tightened. When a laser pulse light is sent into the cable 1, it is scattered variously and the temperature at each light scattering point is determined based on the intensity of Raman backscattering light on the anti-Stokes side.</p> |
