| 摘要 |
PURPOSE:To enable uniform heat treatment of material to be heat-treated by cutting notches for introducing atmospheric gas and notches for discharging the gas in the upper edge of each case so that both the notches meet straight lines radially extended from the center of the case at prescribed angles. CONSTITUTION:Notches 11 for introducing atmospheric gas and notches 12 for discharging the gas are cut in the upper edge of a bottomed tube based on alumina or mullite as a case 10 for heat treatment so that the notches 11, 12 meet straight lines radially extended from the center of the case 10 at prescribed angles theta1, theta2. Atmospheric gas is blown from small holes 25 pierced in the body of a furnace 20 and a cylindrical heating chamber 21 is heated with heaters 24. Such cases 10 each housing material 13 to be heat-treated are piled on a turntable 33 through the top opening of the furnace 20 and the turntable 33 is lowered with an automatic lift 27 under rotation in a certain direction at a prescribed speed. The atmospheric gas is allowed to flow in the cases 10 from the notches 11, circulated and discharged from the notches 12 and the material 13 is heat--treated. |
