| 摘要 |
PURPOSE:To enhance heat-transmitting efficiency, by a method wherein substantially circular arch form projections faced to an air flow are provided on fin surfaces at gap parts provided in the row direction around a group of heat- transmitting pipes, and a plurality of projections perpendicular to the flowing-in direction of the air flow are provided on fin surfaces at gap parts provided in the stage direction around adjacent heat-transmitting pipes. CONSTITUTION:The heat-transmitting pipes 2 are passed through fin collar parts 5 formed by burring in flat plate fins 1 at regular intervals. At the periphery of each of the fin collar parts 5 of the fins 1 at the gap parts provided in the row direction of the pipes 2, the substantially circular arch form projections 6, 7 coaxial with the fin collar part 5 and having a diameter larger than that of the collar part 5 are provided on the upstream side and the downstream side in respect of the air flow. On the other hand, on the surfaces of the fins 1 at the gap parts between the pipes 2 adjacent to each other in the stage direction, the projections 8, 9 perpendicular to the flowing-in direction indicated by blank arrows are provided. |
