GB595910A - Improvements in tubulous vapour generating and heating units - Google Patents

Abstract

595,910. Water-tube steam boilers. BABCOCK & WILCOX, Ltd., and ZOLLER, R. E. July 7, 1945, No. 17381. [Class 123 (ii)] A steam boiler comprises a main furnace 6, Fig. 1, and separately-fired superheater and reheater furnaces 12, 16 respectively, spaces from the main furnace by two oppositely-inclined banks 1, 2 of water tubes which are located in passages 20, 21 between the walls 13, 10 and 11, 17 of the three furnaces and extend them between an upper steam and water drum 3 and lower water drums 4, 5, the said walls stopping short of, for example, the front wall 25 of the boiler to form gas outlets, such as 26, 27, Fig. 2, so that gases from the main and superheater furnaces will flow through the tube bank 1 and gases from the main and reheater furnaces through the tube bank 2. In the construction shown, the various burners 22, 23, 24 of the furnaces are set in the front wall 25, and the gas uptakes 28, 29 from the two tube banks 1, 2 which lead to a common passage 30 housing an economiser and/or air heater, are located at the rear of the boiler. The walls 10, 11, 13, 17 are preferably constituted by tiles resting upon the upper and lower-most tubes of the tube banks 1, 2. The superheater, which is similar to the reheater, comprises an upper or inlet header 31 and a lower or outlet header 33 with two aligned groups of tubes 34, 35, the group 34 lining the side wall 14 and roof 15 of the furnace 12 and the group 35 lining the inner wall 13, the tubes of the latter group being staggered in two rows at the outlet 26 of the furnace. A screen in the form of a longitudinally extending baffle 40 is provided between the furnace outlets 26, 27, the baffle being formed by downcomer tubes 41 connecting the drums 3, 4 and covered with refractory material 42, and further downcomer tubes 43, screened by a baffle 44, are disposed at the rear of the passage 20. Similar downcomers connect the drums 3, 5. In a modification, not shown, no reheater is provided, and the outer wall of the main furnace 6 is lined with water tubes extending from the drum 3 down to a header which is itself connected to the drum 4 by floor tubes covered with refractory material.