| 摘要 |
<p>PURPOSE:To sufficiently and surely maintain atmosphere in a furnace containing low oxygen concn. at a good condition by blowing inert gas from the upper part into the furnace after blowing the inert gas from the lower part into the furnace while diffusing atmosphere in the furnace from the upper part thereof. CONSTITUTION:In the induction heating furnace 1 composing of refractory 2 and sealing material 3 at outer part and providing an induction heating coil 4 a material S to be heated laid on a supporting table 14 on a sealing material 5 at lower part is charged and set through a lifting rod 15. Next, a cover 12 for diffusion at the upper part is opened by working a cylinder 13. Successively, the atmosphere in the furnace 1 is discharged from the diffusion hole 8 while blowing a large quantity of the inert gas of N2, etc., from a blowing hole 6 at lower part. This operation is executed till the oxygen concn. measured at sucking holes for concn. meters at the upper and lower parts 10, 9 lowers to the aimed value. After that, the above cover 12 is closed and heating treatment of the material S to be heated is executed and also the inner gas is blown and controlled from a blowing hole 7 at the upper part to maintain the oxygen concn. in the furnace 1 to the aimed value.</p> |
