GB724934A - Improvements in or relating to tubulous vapour generating and superheating units - Google Patents

Abstract

724,934. Water-tube steam boilers; superheaters. BABCOCK & WILCOX, Ltd. Feb. 9, 1953 [Feb. 7, 1952], No. 3622/53. Addition to 693,803. Classes 123 (2) and 123 (3). In a steam boiler with a radiant superheater comprising hairpin tubes included in a number of panels 22 spaced apart within a chamber 2 leading from the furnace chamber 1 to a lateral gas pass 31, as described in the parent Specification, the hairpin tubes are formed with upper upright portions 22a disposed at the entry to the gas pass 31, inclined intermediate portions 22b, and lower portions 22c which extend along the front wall 4 of the furnace and then project through said wall for connection to inlet and outlet headers 21, 23. Each panel is screened at its rear edge by at least one tube 3a constituted by a suitably bent tube 3 lining the boiler wall 4 ; the front edge of the panel portion 22a may also be similarly screened. Superheater cleaning apertures 51 may be provided in the wall 4. A second radiant superheater in the form of panels 32 of tubes extending along the rear wall of the chamber 2, or of haripin tubes, may, be fitted, the panels being screened by some of the tubes 37a of the tubes 37 lining the rear furnace wall and, preferably, by lower and upper projections 35, 36 on said rear wall. The rising gases from the furnace chamber may, if necessary, be deflected away from the two superheaters and also cooled by streams of air and/or recirculated flue gases which are projected into the chamber 2 through nozzles 38, 42 leading from ducts 39, 41 respectively.