| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a simply-constructed heat exchanger and a manufacturing method for it capable of efficient heating. <P>SOLUTION: An evaporator 10 serving as the heat exchanger heating water 2 by exhaust combustion gas 6 for vaporizing it is provided with a heating cylinder, which has a flow passage 10a axially formed spirally for passing flow of the exhaust combustion gas 6 on the inner circumferential face side and for passing flow of the water 2 in the circumference direction. The heating cylinder is provided with a cylindrical body 11, an outside spiral wavy tube 12 attached coaxially to the outer circumference of the cylindrical body 11 and provided with a rugged shape axially formed spirally, and a guide cylinder 13 arranged coaxially inside the cylindrical body 11. <P>COPYRIGHT: (C)2007,JPO&INPIT |
