GB620622A - Forced-circulation steam generator - Google Patents

Abstract

620,622. Forced-flow steam boilers. SUPERHEATER CO. Jan. 23, 1947, No. 2184. Convention date, Aug. 14, 1946. [Class 123(ii)] A steam boiler comprises a rectangular furnace 10, which is defined by a steel &c. wall 16 lined with superposed coils 31-38 of steam-generating tubes and is fitted at its upper end with fuel burners 12, and a pair of surrounding V-shaped gas passages 17 which communicate with the furnace through bottom ports 15 and are each provided with an offtake stack 18, both passages 17 respectively locating transverselynested convection, coils 21-24 and 25-28, not shown, of additional steam-generating tubes. The inlets 60 of the coils 21-28 are connected to a horizontal water-supply header 30, 40, with feed pump 20, and the outlet 61 of each is connected by an intermediate tube 41-44 to the inlet 65 of one of the furnace coils 31-38, the outlets 66 of the latter opening into a common vertical steam-collecting header 68 on the side of the boiler opposite the header 30, 40. The convection section 17 of the boiler, including the furnace wall 16, is divisible on a diagonal line A-A so that one half thereof, together with the related header 30 or 40, may be removed from its remaining half to expose the coils 31-38 for inspection or replacement, it being necessary merely to remove cover plates 80, 81 enclosing the steam header 68 and break the joints 41-44, say, between the convection coils 21- 24 and the furnace coils 31-34 and that between the header 30 or 40 and the feedwater pipe 83. Each coil 21-28 comprises a series of interconnected parallel tube lengths superimposed in a vertical plane which is bent at approximately the middle thereof to a 90 degree angle, and each coil 31-38 three parallel lengths bent to form a square loop.