| 摘要 |
PURPOSE:To make a predetermined temperature uniform by a method wherein 1st heaters are provided on the circumferential surface of a treatment tube and a 2nd heater is provided at the opening of the treatment tube. CONSTITUTION:First heaters 6, 8 and 10 are provided vertically so as to surround the circumferential surface of the treatment tube 4 of a furnace 2. In the inner cylinder 24 of a cover 18 inserted into the opening of the treatment tube 4, a 2nd heater 30 whose temperature can be controlled independently of the heaters 6-10 is provided in a protective cylinder 34 cutting off treatment gas G. With a heat treatment equipment of such a structure, the temperature of the treatment tube 4 can be predetermined as required so as to be uniform, with gradient and so forth by the independent heating control of the heater 30 together with the heaters 6-10, Moreover, by performing a preheating treatment with the heater 30, the temperature difference between the upper part and the lower part of the treatment tube 4 can be reduced so that the temperature in the furnace can be made uniform. |
