| 摘要 |
PURPOSE:To prevent corrosion caused by combustion gas by a method wherein the heat exchanger for tap-controlled hot-water feeder is constituted by combining the parallel row spiral winding and the longitudinal row spiral winding of composite tubes having corrosion-resistant inner surfaces while the composite tubes, the supporting pillar, supporting bodies and the outer shell thereof are coated by aluminum. CONSTITUTION:Water W, supplied from a water supplying part 4, is sent to a water discharging part 11 through the longitudinal row spiral composite tubes 2 and the parallel row spiral composite tubes 2. In the mean time, the combustion gas of a burner 8 is passed through a space enclosed by the longitudinal row spiral composite tubes 2,then, ascends through a spiral space formed by the parallel row spiral composite tubes 2 and heats the water in the tubes 2. In this case, the composite tubes 2, the supporting pillar 1, the supporting bodies 3 and the outer shell 5 are coated by aluminum or an alluminum alloy 12, therefore, the corrosion thereof may be prevented even if any kind of fuel is used. On the other hand, the heat transmitting area of the heater is increased, the heat exchanging efficiency may be improved and the corrosion-resistant property of the inner surface of the tube may also be improved. |
