GB1070390A - Improvements in or relating to heating chambers with fluid-cooled walls - Google Patents

Abstract

1,070,390. Tube walls for furnaces; supporting steam generators. BABCOCK & WILCOX CO. Dec. 17, 1963 [Dec. 20, 1962], No. 49830/63. Headings F4A and F4B. A heating chamber comprises vertical wall sections supported at different levels and upwardly extending wall cooling tubes connected by resilient conducting means permitting relative vertical movement due to thermal expansion. In a vapour generating unit, Fig. 1 (drawings not shown), comprising a vertical furnace chamber of substantially rectangular cross-section, fired by a number of independently operable cyclone furnaces, a horizontal gas pass (16) containing superheater and reheater tube banks (26) and a vertical gas pass (21), the furnace chamber, in which the steam temperature is controlled by recirculation gases, is defined by walls (11), (12), (13) formed by a plurality of vertically extending parallel cooling fluid tubes (14) with the interspace between them closed by metal webs. The walls which are divided into upper, intermediate and lower sections connected by resilient cooling fluid conducting means (38A), (38B) to accommodate expansion, are supported by a rigid structural steel support system comprising vertical columns (33), horizontal top beams (34) and beam systems (36). The upper and intermediate sections are top supported and the lower sections including the furnaces are bottom supported by beams (37). The intermediate sections are supported from sheer girders (41), Fig. 3, of beam systems (36) which extend on all four sides of the furnace, by rods (51) and plates (45), attached to the girders (41) and to channel sections (43) welded to the tubes (14), in a manner which permits adjustment to allow for horizontal expansion of the wall and deflection of the girder (41). Both connecting means in each wall are at the same level and comprise a multiplicity of horizontally extending return bend loops (56), Fig. 5, in each tube (14), and enclosed in a gas-tight casing (57) covered by insulating material (58). Spaces near the inner ends of the loops are packed with high temperature insulating wool (60) which is held in position between pairs of slidably engaging plates attached to the tubes and shielded from direct radiation by other plates (63). In another embodiment, Fig. 2, the loops are placed within entry ducts (27a) for recirculation gases and are shielded from radiation by tubes of the lower wall section forming vertical loops in sliding connection with the tubes of the upper section.