| 摘要 |
PURPOSE:To achieve better stability in the temperature of a furnace body by releasing an outlet of a cooling tube to the air while a refrigerant in the form of a liquid is supplied to a cooling tube wound on the circumference of the furnace body to reduce the consumption of the refrigerant. CONSTITUTION:When a solenoid valve 44 is opened maintaining the pressure in a refrigerant container 34 at a specified value, a liquid nitrogen 36 within the refrigerant container 34 passes through a large-diameter pipe 40, so that the large-diameter pipe 40, a small-diameter pipe 42 and a cooling pipe 32 are cooled by the liquid nitrogen sequentially. The liquid nitrogen is vaporized gradually with the cooling thereof and finally the nitrogen turned to a gas moves into the air from the tip of an outlet pipe 48. As a result, a furnace body 20 is cooled mainly by vaporization latent heat of the liquid nitrogen. The temperature of the nitrogen gas leaving the outlet pipe 38 approaches the temperature of the furnace body 20 and lets the nitrogen gas fill the perimeter of a supply tube 38 and of an external case 30 of the furnace body 20 so that the environment temperature for the furnace body 20 approaches the temperature of the furnace body 20 thereby achieving better stability in the temperature of the furnace body 20. |
