GB667942A - Improvements in or relating to tubulous vapour generators - Google Patents

Abstract

667,942. Water-tube steam, &c. boilers. BABCOCK & WILCOX, Ltd. June 20, 1950 [June 23, 1949], No. 15378/50. Classes 123(ii) and 123(iii) A steam &c. boiler comprises a downwardly-fired furnace chamber 10 having its front and rear walls 14, 24 lined with steam-generating tubes 16, 36, also its side walls lined with tubes 32, an adjacent gas pass 44. which is defined by an upward extension 24<SP>1</SP> of the rear wall 24 and the upper parts 46 of the rear wall tubes 36, has a lower gas inlet 42 screened from the furnace by intermediate parts 38, 40 of the tubes 36, and locates super-heater sections 48, 56, and a vertical bank of tubes 90. 92 disposed above the wall extension 24<SP>1</SP> across an outlet from the upper end of said pass 44. The tubes 90, 92 extend between an upper steam-and-water drum 12 and a lower water drum 28, the latter being fitted with a tubular attemperator 84, and the wall tubes 16, 36, 32 extend from lower water headers 18, 30, 34, supplied with water from the lower drum 28 through downcomers 26 and branches 110-114 thereof. to the upper drum 12, either direct or through upper headers 20, 34<SP>1</SP> and roof tubes 21. The downcomers 26 line the furnace wall 24, 24' and are screened from the furnace by the lower parts of the tubes 36, and the outlet flue 94 of the boiler .may be led through an air heater 96 adapted to supply secondary air through a duct 98 to pulverized coal &c. burners 102, 104. The degree of superheat is controlled by a valve 74 which proportions the. flow of steam from the outlet header 66 of the superheater section 56 between the inlet 80 of the attemperator 84 and a byepass 82, the latter being connected to the attemperator outlet 86 which extends to the inlet header 50 of the superheater section 48. The several drums and headers are supported from a common beam 103 by ties 105, 107 109