| 摘要 |
PURPOSE:To provide a hot water supplying heat exchanger in which adherence of condensed water to a tube with fins for water-cooling flame is small and hence corrosion scarcely occurs with high durability. CONSTITUTION:A hot water supplying heat exchanger has a heat exchanging tube 3 with fins disposed above a flame generator F in a burning boiler 1 to heat water from an input water tube 4 via the tube 3 and to then output hot water to an output hot water tube 5, and comprises a second tube 6 with fins passed through the generator F in the boiler 1 via a plurality of switching valves 8, 9, 10 of parallel disposition having different flow rates branched from a midway of the tube 5. The plurality of the valves 8, 9, 10 are divided at open areas according to the degree of hot water set temperature and so formed as to be opened in a higher set temperature, the more the valves having larger passing flow rate are provided. |
