| 摘要 |
PROBLEM TO BE SOLVED: To provide a double tube type heat exchanger manufacturable by an extremely simple means with a reduced manufacturing cost, while realizing high heat efficiency. SOLUTION: An inner tube 1 is twisted in a state of inserting the inner tube 1 into an outer tube 3 by using diametrally different two tubes (the inner tube 1, and the outer tube 3). A top part of a thread 2 formed on a tube wall of the inner tube 1 is brought into pressure contact with an inner peripheral surface of the outer tube 3. The inside of the inner tube 1 is formed as a passage of one fluid. A plurality of spiral passages formed between the inner tube 1 and the outer tube 3 are formed as a passage of the other fluid. COPYRIGHT: (C)2004,JPO
|
