PURPOSE: To provide the heat transfer tube, prominent in energy efficiency, and the efficient manufacturing method of the heat transfer tube by a method wherein the tuber is formed with a multitude of axial or spiral grooves, having T, Y or L-shape sectional configuration, on the internal surface of the tube to promote the growth of nucleus of bubble in a boiling phenomenon effectively.
CONSTITUTION: A floating plug 11, a plug 13 equipped with grooves, which is provided with a multitude of protuberances in the axial or spiral direction on the peripheral surface thereof in the arrow sign direction coaxial with the plug 11, and the plug 14, provided with spiral protuberance in a direction intersecting with said protuberance on the smooth peripheral surface thereof, are provided while movable rolling rolls 15, 16 are provided on the extraction processing pipe of both plugs 13, 14. The diameter of extracted material tube is contracted at first by the plug 13 and the roll 15 to form a multitude of grooves axially or spirally on the internal surface of the tube. Subsequently, the diameter thereof is contracted further by the plug 14 and the roll 16 to form the grooves having sectional configuration of T, Y or L-shape by compressing and deforming the multitude of grooves on the inner surface of the tube.
KAWAGUCHI HIROSHI
TOJO SEIJI
YAMAMOTO HIROSHI
