Production of heat transer pipe

Abstract

Abstract PURPOSE: To obtain the heat transfer pipe which has numerous protrusions on the inside wall surfaces and has less pressure losses and high heat conductivity by supporting the inner side of a metal pipe with two sets of turnable plugs provided with a multiplicity of streak grooves on the outside surfaces and pressing the outside surface of the metal pipe with molding rolls. CONSTITUTION: A plug 2 provided with a multiplicity of streak grooves 3 spirally on the outside surface and the second plug 7 provided with a multiplicity of protruding streaks 8 of different angles spirally at a diameter smaller than these are disposed in a metal pipe 1 such as copper, aluminum or other. These plugs 2, 7 are supported turnably by a shaft 4. Conical rolls 5, 10 of gradually increasing diameters toward the advancing direction of the metal pipe 1 are disposed 3 pieces as one set spacially at an angle of 120°. In this state, the molding rolls 5, 10 are turned by drive units to press the metal pipe 1 while pulling the same in the arrow direction, thereby pressure-engraving and forming the protruding streaks on the inside wall surfaces. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Atsuo Seki
• 👤 Sumita Okano
• 👤 Fujio Shimizu

Bibliographic Details