Method and apparatus for the helical bending of the tubes of a tube coiling of a steam generator

摘要

1. A process for coiling tubes constituting the nest of tubes of a steam generator, it being required to helically wind the tubes in a plurality of evenly spaced apart concentric successive layers around a cylindrical hub (4) ; in which the end of the tubes is fixed on the cylindrical hub or on a member connected to said cylindrical hub, and the tube or tubes are wound on the hub by a relative displacement between the rotating hub and the support of the tubes, characterized in that it comprises, beforehand, constituting a plurality of rectilinear tubes (1) and bending one of the end portions of each tube (1) in the shape of a helix identical to that of the winding of the tube around the hub, the radius of curvature of the bend thus obtained substantially corresponding to the radius of the winding of the tube (1), then fixing the end of this or these bent tubes (1) on the hub and subjecting this hub to a simultaneous movement of rotation and movement of longitudinal translation so as to wind the tube or tubes in a spiral around the hub, during the winding operation, the straight portion of the tube or tubes being guided, in the vicinity of the hub, by guide elements mounted to be fixed in position, and bending on the hub the other end portion of the tube or tubes which has just been simultaneously wound, so as to complete the winging.