| 摘要 |
PURPOSE:To prevent the clogging of a gap due to drainage by a method wherein a substrate plate of the fin around the erected upper end of an erected slit fin or a louver type fin is treated hydrophobically. CONSTITUTION:Both the surfaces of the substrate plate 1 of the fin around the upper short side 5a or 6a of the slit fin 5 are prepared so as to form hydrophobically treated surfaces 10 or 11. Consequently, a wetted surface usually produced over hydrophilically treated surface does not produce over the surfaces near the erected upper end, but the drainage grows up in the form of drops and falls down when grown up to a certain size, resulting in eliminating water film to adhere to the erected gap LW at the erected upper end. Accordingly, even if a part of water drops happens to remain at the lower part of the rising gap LW, they are blown off by draft, resulting in enabling to prevent the entire rising gap from clogging due to the formation of water film. |
