| 摘要 |
PURPOSE:To obtain an excellently durable heat exchanger capable of quick rising and small post-boiling of water by using a system in which a sheathed heater with a coil whose diameter is becoming gradually smaller toward the lower end is provided, and water of a turning and ascending flow is given from the outer circumference, passed through the layers of a coil by centripetal flow, and directed upwards. CONSTITUTION:A sheathed heater 6 in which the diameter of a coil is made smaller toward the lower end is set in an inverted form on a can body 7. The terminals on both ends are water-tightly soldered to a cap plate 10 and a bottom plate, a water inlet tube 8 is soldered to the lower part of the can body 7 in such a way as to lead it toward the tangent direction, and thereby incoming water goes up while being turned. To the tube wall of the sheathed heater 6, therefore, a turning flow in the winding direction of the coil and a centripetal flow passing through the layers of the coil are given, and the heated water flows down in a hot water discharge tube 9 and is discharged. The further incoming water goes forward upwardly, the more heat it receives, the more quickly the rising time of hot water temperature after the beginning of hot water discharge becomes. Since no local overheating occurs in the sheathed heater 6, post-boiling after the stoppage of water is less, dielectric breakdown by repeated use is less, and the durability of the heater is increased. |
