| 摘要 |
PURPOSE:To easily and exactly detect the erosion of refractories of an RH type vacuum refining furnace by inserting metallic protective pipes embedded therein with thermocouples by insulators into the easily erodable points such as side walls and bottom of the furnace and monitoring the electric resistance values between the protective pipes and the thermocouples. CONSTITUTION:Contacts 3A of the thermocouples in the metallic protective pipes 2 and the insulating material 4 is preliminarily packed into the pipes, then such pipes are inserted into the refractories of the side wall parts 1a and furnace bottom part 1b in the vacuum furnace of the RH type vacuum refining furnace where erosion is liable to be generated by the fluid contact of a molten steel. The thermocouples and the protective pipes 2 conduct to each other through the molten steel and the resistance between both decreases sharply when the refractories 6 of the side wall 1a and bottom 1b are eroded by the flow of the molten steel and the insulating material 4 in the bottom part 2A of the pipes 2 or near the same is melted. Such decrease is detected by a resistance measuring instrument 7 and when the value decreases to the value set by a controller 10 or below, an alarm is emitted by an alarm 11 and therefore, the operation of the vacuum refining furnace is stopped and the damage of the furnace side wall and bottom is prevented. |
