| 摘要 |
PURPOSE:To provide a titled device which improves remarkably productivity and can reduce an energy cost by constituting a hardening furnace and a tempering furnace for heat treating a PC steel bar in such a way that gas firing furnaces are used and that many wire rods can be passed simultaneously in parallel in the furnaces. CONSTITUTION:A heat treating device for PC steel bars produces PC steel bars B by subjecting three pieces of wire rods A for PC steel bars supplied respectively from three lines 30, 40, 50 of wire feeders 1 to working such as drawing then hardening the wire rods in a hardening furnace 20 and a water tank 8 for the hardening furnace then tempering the wire rods in a tempering furnace 21 and a water tank 10 for the tempering furnace. Three pieces of the wire rods A in such heat treating device are passed simultaneously at an equal interval in parallel in a furnace body 22 consisting of refractories 26 constituting said furnace 20 and furnace 21 by means of plural hearth rollers 23 disposed in the direction intersecting orthogonally with the direction where the wire rods A pass. Plural gas burners, 24 are further disposed in the ceiling part of the body 22 and inexpensive gases are burned with said burners so that the wire rods A transferred on the rollers 23 are uniformly and efficiently heat treated. |
