GB794703A - Improvements in and an improved method of operating tubulous vapour generating and vapour heating units - Google Patents

Abstract

794,703. Water-tube steam boilers; superheaters. BABCOCK & WILCOX, Ltd. Sept. 27, 1956 [Sept. 29, 1955], No. 29562/56. Classes 123(2) and 123(3) A water-tube boiler fired with a byproduct gas such as blast-furnace or coke oven gas and with a richer fuel such as oil, the fuels being used singly or in combination, comprises a steam generating tube lined, vertical furnace 10 having a top outlet into a lateral gas pass 16 locating a double bank of generating tubes 23 extending between a water drum 20 and a steam and water drum 22. Positioned in the upper part of the furnace across the outlet to the pass 16 is a superheater 30, the tubes of which extend downwardly to the rear furnace wall 13 at a level below that of the drum 20. In the front wall 11, at levels below the lower ends of the tubes of the superheater 30, are disposed two rows of combination oil and gas burners 40, 41 and above these rows opposite the said lower ends is located a row of oil atomizing burners 52. When burning the byproduct gas alone, the two rows of gas burners 40, 41, are operated. If the gas supply is too low, oil is injected through burner tubes arranged to discharge coaxially through the gas burner ports 42 When no gas is available oil is burnt alone, the oil burners in the upper row of ports 42 and the burners 52 being operated. Under this condition the final steam temperature is maintained at the same level as with gas firing alone by the increase in radiant heating of the superheater 30 which occurs when the burners 52 are brought into use.