Tabular voice detection device null of the band plate which inside the heat treat furnace is conveyed

摘要

PURPOSE: To prevent the effect of heat as much as possible in the furnace of an inspecting apparatus for inspecting the passing state of strip plate, which is conveyed in a heat treating furnace. ;CONSTITUTION: A cavity part 18, which is formed of a surrounding wall 8c comprising refractory material, is provided in a primary cooling furnace so as to face a furnace wall 8c through a strip plate 2. An opening part 20 facing a surface 2a of the strip plate 2 is provided at a slant surface part 19a of the surrounding wall 19. A counter opening part 25 is provided at the corresponding position of the furnace wall 8c. A light projecting device 22 is provided in the cavity part 18. A light receiving device 27 is provided at the outside of the counter opening part 25 of the furnace wall 8c. The passing state of the strip plate can be detected by using a pair or the light projecting and receiving devices. The installation cost can be decreased, and the maintenance can be readily performed. The parts of the light projecting and receiving devices, which are provided in the furnace, are thermally isolated, and the detecting state can be stabilized for a long period.;COPYRIGHT: (C)1993,JPO&Japio