| 摘要 |
PURPOSE:To obtain a lightweight and corrosion-resistant heat exchanger by brazing an Al brazing foil to the surface of an Al extruded tube by using a noncorrosive flux, inserting corrugated fins between tubes bent in the shape of snake motion, and heating and joining them. CONSTITUTION:To the surface of an Al extruded tube 1 provided with plural partition walls 1a and holes 1b, Al brazing foil 3 whose elctrode potential is lower than that of the tube 1 and shows a sacrificial corrosion effect is brazed by using a noncorrosive flux 6. Subsequently, the tube 1 is bent in the shape of snake motion, and thereafter, corrugated fins 2 made of Al is inserted between adjacent tubes 1, both of them are heated to the melting temperature of the brazing foil 3, and the tube 1 and the fins 2 are joined through a brazing foil layer. In this regard, as for the flux 6, a fluoroaluminum acid potassium compound is used, and the thickness of the brazing foil 3 is set to 20-200mum. In this way, a lightweight and corrosion-resistant heat exchanger can be manufactured. |
