GB1348486A - Vapour heating and vapour generating units - Google Patents

Abstract

1348486 Steam generators BABCOCK & WILCOX Ltd 19 May 1971 [19 May 1970] 24154/70 Heading F4A A vapour generator and superheater which is transportable as a unit from factory to site, comprises an elongated casing 1 containing sinuous heating tubes 30, 31, 32, having at one end a wall 10 with apertures 11 for burners and at its other end a flue gas outlet. The wall of the casing, which is preferably of rectangular crosssection, is formed of longitudinal evaporator tubes 2 having fins welded together to form a continuous gas-tight wall and stiffened by backstays 40 connected by links (41), Fig. 3 (not shown), to downcomer pipes (4) disposed at each corner of the casing. The lower wall 10 is movable axially of the generator. The wall tubes are connected to lower distributers 5 fed through the downcomers (4) from a steam/water drum 3, and they supply steam to collectors 6 connected to the drum. One or more tubular partition walls 15 subdivide the furnace chamber 12 and whose tubes are connected between lower headers 16 and collectors 24 also feeding the drum. Feed water is supplied to the drum 3 through a pair of primary economizers 34 disposed in the exhaust flues, Fig. 2A (not shown), and a secondary economizer 32. After passing through steam separators in the drum, the steam passes through primary and secondary superheaters 31, 30. The superheater and economizer tube banks 30, 31, 32 are supported by hanger tubes 36 depending from headers 37 and which feed steam to the secondary superheater 30. The generator is arranged for transportation, without the upper flues and economizers 34, in a horizontal position lying on the casing wall 2b which is adjacent the various headers 30a-32b. During transportation the backstays 40 are supported by brackets (43), Fig. 3 (not shown), and diagonal cross-bracing may also be used.