| 摘要 |
PURPOSE:To obtain a compact and durable heat exchanger capable of equalizing the flow of water and of permitting quick-rising and small post-boiling by a method in which a can body having an inside diameter slightly larger than the outside diameter of a coil and an inner cylinder having an outside diameter slightly smaller than the inside diameter of the coil are provided, and a heating portion is formed by a coiled water passage formed between the can body and the inner cylinder. CONSTITUTION:The inside diameter of a can body 7 is made slightly larger than the outside diameter of a sheathed heater 6, and the outside diamter of an inner cylinder 10 is made slightly smaller than the inside diameter of the coil of the sheathed heater 6. The sheathed heater 6 is set between the inner cylinder 10 and the can body 7, where a coiled water passage is formed. Water coming from a water pipe 11 goes up in the inner cylinder 10, heating is electrically started by the sheathed heater 6, and the water coming out of the upper end enters between the inner cylinder 10 and the can body 7. The water goes down spirally along the coiled water passage while contacting with the sheathed heater 6 and is heated by a heat exchanger to become high-temperature water which is in turn discharged from a pathway 12. In the heating chamber, water is held in a comparatively small amount and flows with uniform and rapid speeds and heat conduction is attained. The rise time of the temperature of hot water after being discharged is quick, post-boiling of the hot water is less, and the durability of the sheathed heater 6 is increased. |
