| 摘要 |
The end of a tubular member to be heated is received in an annular space between a central core and a shroud. Hot gas passes through passageways in the central core against the inside surface of the tubular member, then along the inside surface to the end of the tubular member, and then along the outside surface of the tubular member. At least one of the flow of hot gas along the inside surface and the flow of hot gas along the outside surface of the tubular member is caused to follow a spiral path. |
