GB715324A - Improvements in or relating to water heating coils for steam generating apparatus and methods of making such coils - Google Patents

Abstract

715,324. Forced-flow steam boilers. CLAYTON MANUFACTURING CO. June 15, 1951, No. 14266/51. Class 123(2) [Also in Group XXII] A steam-generating pipe coil 35, Fig. 1, for a forced-flow steam boiler comprises steam-generating proper and preheating sections 38, 36 and a section 37 which lines the combustion chamber 20 and encloses the section 38, said section 37 consisting of a double-wound helical coil made of two lengths of pipe 50, 51 interconnected at one end by a return band 52 and the other ends 53, 54 of said lengths being welded respectively to the outlet 45 of the preheater section 36 and the inlet 55 of the generating section 38. In the example shown the coil has sixteen turns, with those in the upper half abutting and those in the lower half spaced slightly apart by clips 56 welded to or inserted between adjacent turns. Winding apparatus for the coil 37 comprises a mandrel 89, Fig. 2, which is rotated by a reversible motor 87a through reduction gearing 86 and a shaft 88a and is fitted with a clamp 105 provided with fingers 111, 112 adapted to be received within the ends 53, 54 of the pipes 50, 51 to secure the latter to said mandrel. The inner end of the mandrel is provided with a flange 90, and, at the other end, the shaft 88a carries a bushing 91 which is supported in a two-part journal 93, 94 carried by a triangular frame 99 detachably mounted on the base 84 of the apparatus. The pipes 50, 51, supported by a table 81, are applied to the clamp 105, whereupon the mandrel 89 is driven in a clockwise direction for, say, eight turns. Spacer elements are now inserted between the two pipes and between the pipe 50 and the last wound turn respectively and the winding completed. The clips 56 are then inserted between the spaced turns of the coil, and next the frame 99 is removed from the apparatus, a shell 116 is slipped over the coil until it engages the unwound ends of the pipes 50, 51, which are then connected by the welded-on return bend 52 and bent around the mandrel, whereupon the shell 116 is pushed over the remainder of the coil into engagement with the flange 90. Finally the clamp 105 is released and withdrawn through a slot 108 in the mandrel to permit the coil 37 and surrounding shell 116 to be removed together from the latter. Instead of joining the ends of the pipes 50, 51 by a return bend after winding, this operation may be effected first or, alternatively, a single length of tubing may be bent to provide a return bend with substantially parallel and equal portions on both sides of the latter, the coil then being wound after engagement of the return bend with a clamp on the mandrel. Specification 715,325 is referred to.