| 摘要 |
PURPOSE:To effectively heat a junction part of a steel pipe, and to press-weld it satisfactorily, by spraying a doughnut-like flame eddy which rotates in one direction, to a groove provided on the steel pipe junction part. CONSTITUTION:Plural nozzles 14 which jet high temperature gas 15 at a regular pitch, at a right angle in the axial direction of a steel shaft and at a larger angle than 0 deg. in the radial direction, when a burner 18 has been fitted to steel pipes 1, 2, are installed to the burner 18. This burner 18 is fitted to the steel pipes 1, 2, and a doughnut-like flame eddy 20 which is concentrical with the steel pipes 1, 2 and rotates in one direction is formed. Subsequently, this eddy 20 is sprayed to a steel pipe junction part 17, and it is heated up to a temperature which is suitable for welding with pressure. In this way, the junction part 17 of a thick steel pipe is press-welded easily and satisfactorily. |
