| 摘要 |
<P>PROBLEM TO BE SOLVED: To avoid damage to a heat transfer tube by reducing a temperature difference on the outer surface of the heat transfer tube. <P>SOLUTION: The air heater 1 comprises the heat transfer tube 10 in a triple tube structure consisting of an outer heat transfer tube 12 sealed at its front end, a first inner heat transfer tube 14 inserted into the outer heat transfer tube 12 and sealed at its front end, and a second inner heat transfer tube 16 inserted into the first inner heat transfer tube and opened at its front end, for carrying heated air into a gap 38 formed between the first inner heat transfer tube 14 and the second inner heat transfer tube 16 and to the inside of the second inner heat transfer tube 16. Herein, the outer heat transfer tube 16 at the gap 34 formed between the outer heat transfer tube 16 and the first inner heat transfer tube 14 and a portion of the first inner heat transfer tube 14 at its base end are closed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
