| 摘要 |
PURPOSE:To prevent increase of oxygen concentration within a heating chamber by sucking nitrogen gas into the heating chamber with a suction force of a fan in place of an external air. CONSTITUTION:The N2 gas is supplied to a heating chamber 1 through a supply pipe. In this case, the N2 gas is partly supplied to a bypass 20 while passing through the supply pipe and is sucked with a suction force of a fan 5 into the heating chamber 1 along a rotating shaft 10 through a through hole 19 of a casing 9, a gap 16 at the central area, a gap of a bearing 13 in the lower side, a shaft hole 22 of a fitting plate 14 and a shaft hole 17 of the heating chamber 1 as indicated by an arrow mark of broken line. When the N2 gas is introduced into the heating chamber 1 from the through hole 19 which is located in the side of the heating chamber 1 rather than a sealing part 18 of the casing, the N2 gas is extensively sucked into the heating chamber 1 along the rotating shaft 10 with a suction force of the fan 5. Therefore, flow of the N2 gas prevents flow of external air into the heating chamber 1 and thereby increase of oxygen concentration within the heating chamber 1 can be prevented. |
