| 摘要 |
PURPOSE:To enable increasing the freedom of heat treatment by preventing the corrosion of a manifold. CONSTITUTION:A cover composed of quartz is installed so as to cover the inner peripheral surface of a metal manifold on the lower side of a reaction tube, and N2 gas is supplied for purging from a gas introducing tube 40 into a gap S between the cover and the manifold. The inner edge portions of gas supplying tubes 5, 7 and discharging tubes 6, 8 are constituted of quartz tubes 52, 62, 72, 82, and through holes are formed in the cover. Quartz boards 54, 64 74, 84 are engaged with the through holes and welded, and the quartz tubes 52, 62, 72, 82 are inserted into the holes of the quartz boards 54, 64, 74, 84. Cylindrical members having flanges are engaged with the parts between the quartz tubes 52, 62, 72, 82 and the quartz boards 54, 64, 74, 84. |
