| 摘要 |
PURPOSE:To prevent fins from being broken and lacked by local temperature difference generated during using by a method wherein a plurality of tubes made of ceramics are provided and rendered lacked of the end rims of the fins made of ceramics which are positioned at the inflow side of high-temperature gas. CONSTITUTION:Tubes 1 made of ceramics are penetrated through fins 2 and rendered lacked of the end rims of the fins 2, positioned at the inflow side of high-temperature gas than a plane including the center lines of the tubes 1a constituting the first row of the inflow side of the high-temperature gas. Fluid, such as water or the like, is made to flow through tubes 1, 1a and the high-temperature gas G, generated by the combustion of a burner or the like, is made to flow through the gaps between fins 2 whereby heat exchange is effected. In this case, a temperature difference (t2-t1) is generated at the end rims of the inflow side of high-temperature gas of the fins between the temperature (t2) in a part near the inflow side of the high-temperature gas and the temperature (t1) in the inside part apart from the inflow side of the high- temperature gas whereby the difference of thermal expansions is generated, however, because of lack of the end rims of the fins 2, the concentration of thermal stress may be avoided and the fins 2 may be prevented from breakage.
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