GB701624A - Improvements in or relating to superheaters or the like heat exchangers and more particularly to tube connections therefor - Google Patents

Abstract

701,624. Joining tubes to headers; junctionpieces. BABCOCK & WILCOX, Ltd. Feb. 13, 1952 [Feb. 15, 1951], No. 3820/52. Class 99 (1). [Also in Group XIII] A group of superheater tubes is connected to a header 17 by a junction-piece comprising a neck 29 welded into an opening in the header and a base 31 increasing in cross-sectional area from the neck, and having divergent passages 44 leading from the neck to the individual tubes 10 of the group. The angle of divergence is less than 25 degrees The junction-piece may accomodate two rows of tubes 35, 36, Fig. 3, of three tubes each, of which the lower row 36 is arranged so that the axes of its passages 44 are in a plane parallel to the axis of the neck, the bores of the passages and the neck being tangential to a common plane. The tubes are welded into recesses 33 at the end of the passages. The area of the bore of the neck is equal to the sum of the areas of the tube bores. The junction-pieces are spaced in the header wall so that all the rows of tubes in a bank are equidistantly spaced. Handholes in the opposite wall of the header to give access for welding &c. are spaced so that there is one for every two junction-pieces. The holes in the cylindrical header are non-radial, the wall being recessed at 50 to provide a seat for weld metal which is normal to the axis of the neck 29. The neck is expanded before welding into grooves 48 in the header wall, and is re-expanded after welding. Means are provided for supporting the tubes (see Group XIII). Specification 467,879, [Group XIII], is referred to.