| 摘要 |
PURPOSE:To enable the early detection of the leakage of molten Al or the wear of a protective pipe, by connecting a pipe failure detection circuit to the 2nd pipe 2 which is provided in the 1st pipe inserted and fixed in the through-hole in the side wall of a vessel and has a heating element at the inside. CONSTITUTION:When the 1st pipe 2 ruptures in a vessel 9 of an under heater type for molten Al, the molten Al10 intrudes into the space between the pipe 2 and the conductive 2nd pipe 4. Then an earth rod 8 and the pipe 4 are short- circuited by the molten metal 10, by which an alarm 15 is triggered. The pipes 2 and 4 are partially insulated by an insulator 3, and the heating element 5 in the pipe 4 is held at the center of the pipe 4 by an electrically insulating collared pipe 1, and is sealed by means of a sealant 6. |
