| 摘要 |
PURPOSE:To enable the titled heat transfer pipe to maintain a high heat transfer capacity over the entire length thereof by a method wherein the case of a refrigerator or the ike, a plurality of inclined grooves and a water collecting passage with which the grooves communicate at a certain angle are provided on the outer surface of the condensing heat transfer pipe. CONSTITUTION:Two kinds of grooves 1 are provided on the outer surface of the condensing heat transfer pipe at equal angles of inclination with respect to the axis of the pipe. Both kinds of grooves intersect one another at their upper ends 6 while the lower ends 7 of the grooves open in the water collecting passage 8 extending in the direction of the axis of the pipe. The condensing heat transfer pipe thus produced is capable of maintaining a high heat transfer capacity without being flooded by a condensing liquid even at the lower end thereof since the liquid drawn into the grooves 1 due to its surface tension flows into the water collecting passage 8 before it fills the grooves. The instant heat transfer pipe is manufactured in such a manner that a metallic plate 10 is passed between a roller 11 provided with a number of two kinds of helical groove 9 and a drive roller 12, rounded by a pipe shaping machine and both side edges of the rounded material are connected by welding as at 13. |
