Patent GB-1003214-A (GB)
Title: Improvements in tubulous heat exchangers
IPC: F22B37/68
Filed: 1961-12-05
Abstract: 1,003,214. Tube walls for furnaces; water-tube steam boilers. BABCOCK & WILCOX Ltd Dec. 5, 1961 [Dec. 7, 1960], No. 43524/61. Headings F4A and F4B. In a tubulous heat exchanger comprising a heating fluid passage lined by horizontal, parallel - connected tubes arranged in sections disposed one above the other and connected in series by generally upright tube lengths for the forced flow of fluid to be heated therethrough, the tubes are supported at horizontally spaced intervals by upright tube support means located outside the section and each such support means is heated throughout the height of the section by an upright tube loop outside the section and associated with a different horizontal tube length. The invention is applied to a forced flow steam boiler furnace chamber of rectangular cross-section lined with horizontal tubes 16 arranged in sections A, B, C, shown developed in Fig. 6, and connected in meander fashion. The tubes shown line one half of the furnace walls, i.e. the end wall and half the back and front walls, the other half being lined by an identical set. Upright support channels 17 are evenly distributed around the outside of the furnace chamber and extend throughout the height thereof. At each support channel 17, a tube length of each section is bent outwardly of the wall and formed as a vertically elongated loop extending throughout the height of the section, as shown in Fig. 6. A tube length 16A is bent outwardly of the wall as at 16B into the channel 17 and upwardly, in arcuate form, to extend in the channel to approximately the uppermost tube length in the section D where it is reversely bent within the channel 17 to extend downwardly to 16D at which level it is bent first sidewardly to cross outwardly of tube portion 16B and then downwardly as at 16E towards the lowermost tube of the section where it is again reversely bent in the channel to extend upwardly as at 16F. At 16G the tube is bent inwardly to re-enter the wall as tube length part 16H at a level immediately below the level of tube part 16A. A tube length part 16I is bent upwardly at 16J adjacent to the support channel 17 and sidewardly, in the wall, to extend in the same direction as tube length part 16K. Anchoring means for the tubes are provided by plates 22, 23, the tube part 16D being welded to the plate 22. The plate 22 passes through a vertical slot in the channel 17 and is secured in a further slot in the plate 23 by welding, the plate 23 in turn being welded to the channel 17. The slot 24 allows initial vertical positioning of the tube section during assembly. The remaining tube lengths with the exception of the uppermost and lowermost tubes of each section and the tube lengths including bent portions 16B, 16G and 16J are hingedly connected to vertical plates 28, 29 as shown at 31, Fig. 4, by a" U "member 30. These plates 28, 29 extend vertically within the loops to which they are welded via fillet plates 26, 27. The top and bottom tube lengths 16 of section D are secured to the above plates by fillet plates 33 welded to hinge-like extensions of the plates 28, 29. A gas-tight closure for the heat exchanger is provided by casing plates 34 secured to legs of the channel supports.