| 摘要 |
909,557. Water-tube steam boilers; superheaters. BABCOCK & WILCOX Ltd. July 14, 1961 [July 16, 1960], No. 25686/61. Classes 123 (2) and 123 (3). A tubulous boiler in which the heating fluid e.g. the coolant gas from a nuclear reactor, is under pressure comprises a pressure vessel through which the fluid passes and has a lower part enclosing an economiser and steamgenerating tube bank, an intermediate steam and water separating drum, part of the wall of which forms part of the wall of the pressure vessel, and an upper part enclosing a steam superheating tube bank, the connections to the drum from the tube banks being enclosed within the vessel. Fig. 1A shows the upper part 4 of a cylindrical pressure vessel together with a spherical steam and water drum 6 and Fig. 1B the lower part 7 of the vessel. Water enters the boiler by a pipe 17 and rises through a helicoidal economiser tube bank 23 into a bulbous chamber 27 in which it mixes with water returned from the steam and water separating drum 6. The mixed water enters a helicoidal steam generating tube bank 35 through risers 32 and headers 33 and 34, the emergent steam and water passing through headers 41 and 42 and riser pipes 43 into an outer annular compartment 44 of the steam and water drum 6. The mixture of steam and water passes into a number of centrifugal separators 46 the water being discharged into the lower part of the drum 6 and returning via pipes 74 and downcomer pipe 37 to the mixing chamber 27. The steam passes through primary driers 47, secondary driers 52 and enters a helicoidal superheating tube bank 50 through riser pipes 53 and headers 54 and 55. Superheated steam leaves the boiler by pipes 61 at its upper end. The heating gases enter the pressure vessel at this end through an opening 64, flow downwardly past the superheating tube bank 50, through a duet 68 which extends through the drum 6, frusto-conical plates 65 and 65A funnelling the gases respectively to and from the duct 68, past the steam generating and economiser tube banks 35 and 23, and leave the vessel through an opening 14 at the lower end. External connections to the steam and water drum 6, e.g. for a level gauge and for balancing pipework between drums when operating boilers in parallel, may be made without passing through the wall of the pressure vessel itself.
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