GB490457A - Improvements in forced flow steam and other vapour generators - Google Patents

Abstract

490,457. Forced - flow steam boilers steam superheaters. BABCOCK & WILCOX, Ltd. Dec. 18, 1936, No. 34795. Convention date, Dec. 18, 1935. [Classes 123 (ii) and 123 (iii)] A forced-flow boiler has a number of parallel connected long small-bore tubes arranged horizontally along the walls of a vertical combustion chamber 1 and of a parallel flue containing an economizer 202a, 202b and a superheater 242. The tubes are connected to a vertical supply header 204 and pass completely around the bottom part of the combustion chamber and flue, and then they are bent upwards and arranged in flat loops across the flue with portions extending around the sides of the combustion chamber and between the combustion chamber and the flue. They are then again bent upwards to form superposed flat coils extending about half way across the flue and with portions around the combustion chamber, and finally they are arranged around and over the top of the chamber. A superheater 242 is arranged in the part of the flue not occupied by tube coils. Above the superheater and tube coils are economizer sections 202a, 202b each extending half way across the flue and separated by a wall L, and an economizer section 202 extending across the full width of the flue. Dampers M, N above the two passes formed by the partition L control the flow of gases over the superheater. The vaporizing tubes are fed with water through resistors, as described in Specification 490,459, and they discharge into a separator the water discharge from which is taken through a tubular air heater 206. A further tubular air heater 207 is heated by the hot feedwater on its way to the supply header 204. The feed and fuel supplies are controlled as described in Specification 490,456.