| 摘要 |
942,401. Forced-flow steam boilers; superheaters. BABCOCK & WILCOX CO. May 13, 1960 [May 13, 1959], No. 17082/60. Heading F4A. In a forced-flow, once-through steam boiler comprising an upright furnace chamber 10 fired by cyclone furnaces 24 and having an upper gas outlet 16 opening into a horizontally extending pass 17 occupied by a first stage secondary superheater 27, a reheater 28 and a second stage secondary superheater 29, followed by a downpass 19 locating a primary superheater 30 and economizer 31, the outlet header 63 from the secondary superheater 29 and the reheater inlet and outlet headers 70, 71 are disposed below the gas pass 17 to reduce the length of the high quality steel pipes leading the steam to and from the turbine associated with the boiler. The furnace 10 and gas passes 17, 19 are lined with steam generating tubes which are hung from cross-beams 75. To allow for the differential expansion of the tubes of the steam heaters 28, 29 relative to the pass lining tubes, the superheater inlet header 62 and intermediate return bends of the superheater and reheater are suspended from the beams 75 by hangers 78, 80 respectively, these hangers including springs 79, 81. Furthermore, the headers 63, 71 carrying steam at high temperature are supported so as to permit their longitudinal expansion, the headers being mounted on saddles 87 which are supported on spaced beams 88 extending between I-beams 89, 90, the ends of which are hung from the pass lining tubes by hangers pivotally connected thereto. Expansion bends 28c, 29c provided in the tubes from the reheater and superheater respectively to absorb movements that occur between the floor 18 of the pass 17 and the headers. Steam temperature is controlled by recirculating cooled combustion gases to the furnace 10 through ports leading from ducts 36, 37. Specification 868,613 is referred to.
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