GB727712A - Improvements in tubulous vapour generating and vapour heating units - Google Patents

Abstract

727,712. Steam superheaters. BABCOCK & WILCOX, Ltd. Sept. 8, 1953 [Sept. 9, 1952], No. 24797/53. Class 123 (3). A steam &c. boiler has a gas pass 9 extending laterally from a vertical furnace chamber 16 and locating a secondary superheater 10 and reheater 12,.14, the pass leading to a downpass not shown, in which is disposed the primary superheater. Saturated steam from the steam and water drum 38 flows through tubes 90, header 92 and tubes 80, 82 to the primary superheater from which it passes through the secondary superheater and thence to the point of use. The superheater 10 and reheater 12, 14 each consist of banks of multiple bend U- tubes spaced apart across the pass 9, the banks being pendently supported by headers 18, 20 and 22, 24 respectively, the headers being hung from steelwork 26 by supports 95, 98. The floor of the pass 9 is lined with steam generating tubes which are bent upwardly to form a screen 40 defining the rear end of the pass and is formed with steps 28, 30 and 32. The upright parts 42, 43 and 44 of the lining tubes are disposed in proximity to the rearmost tubes of banks 10, 12 and 14 respectively and are connected thereto by guides 46, 47 and 48 which serve to hold the banks in position whilst allowing for their vertical movement due to expansion. As shown in Fig. 4, each guide consists of a T-headed member 50 welded to the upright part 44 of a floor lining tube and slidably engaging a T-slotted member 54 welded to the rearmost tube length 14<SP>1</SP> of the steam heating bank. The location of the guides downstream of the tube banks protects them from the corrosive effect of the furnace gases.