| 摘要 |
PURPOSE:To make it possible to manufacture easily the titled pipe by a method wherein the surface of a flat metal is subjected to various kinds of processings for improving the heat transfer efficiency thereof and then the processed metal is shaped into a pipe of desired sectional configuration by an electric seam welding method or the like with the processed surface of the metal forming the internal surface of the pipe. CONSTITUTION:A metallic particle layer 3 is first formed on the upper surface of the flat metal 2 by spraying metallic particles thereon so that the surface of the flat metal is made porous due to the existence of the layer 3. Then the metal is wound into a tube having a circular, elliptical or compressed configuration in section and the longitudinal side edges of the metal are welded together by an electric seam welding method or the like. However, the processing of the above metal is not always limited to the formation of the porous layer thereon but other than the flame spraying of metallic particles, it covers various kinds of steps such as the formation of a grooved surface layer, the formation of a resin coated surface layer and the like any of which may be applied according to the use of the pipe. |
