| 摘要 |
PURPOSE:To reduce the weight of the heat exchanger such as an instantaneous hot- water heater or the like and improve the corrosion-resistant property as well as the heat exchanging efficiency thereof by a constitution wherein iron composite tubes, having corrosion-resistant metal layers at the inner surfaces thereof, are arranged in parallel and are wound into a spiral-shape through a column-shaped body or the like and subsequently, they are arranged in longitudinal arrangement and are wound into the spiral shape. CONSTITUTION:Water W is supplied from a water supplying part 4 to a water discharging part 11 through the longitudinally arranged spiral composite tubes 2 and the parallel row spiral composite tubes 2, then, a burner is ignited. Combustion gas passes through a space enclosed by the longitudinal row composite tubes 2 at first, subsequently, ascends through a spiral space formed by the parallel row composite tubes 2 and heats the water in the composite tubes 2. According to this constitution, the combustion gas contacts with two spiral tubes of longitudinal and parallel arrangements, therefore, a contacting area is increased and the heat exchanging efficiency may be improved. On the other hand, the inner surface of the composite tube 2 is lined with the corrosion-resistant metal or alloy, therefore, the corrosion-resistant property thereof may be improved. |
