Double pipes for mixed boilers, to the methods of manufacturing such pipes and to the corresponding boilers

摘要

A double pipe is disclosed for mixed boilers comprising rectilinear segments in which the two duct sections are juxtaposed laterally. Each section (A,B) is defined, on its side the furthest away from the other section, by a plate (1,7) whose two longitudinal borders (2,3,8,9) are curved and are welded against the longitudinal borders of an intermediate partition (4) and this intermediate partition has stamped bosses (5) whose tops (6) are in contact with said plates and are fixed thereto.