GB745235A - Improvements in or relating to a controlled circulation steam boiler - Google Patents

Abstract

745,235. Forced-flow steam boilers. COMBUSTION ENGINEERING, Inc. June 17, 1953 [July 5, 1952], No. 16705/53. Class 123(2). A forced-flow steam boiler comprises a vertical furnace 2, Fig. 1, of rectangular crosssection, with burners 8, the gases from which are directed successively through a horizontal gas pass 4 locating a high temperature superheater 32 and reheater 34, a vertical pass 6 locating a low temperature superheater 30 and economizer 29, and an air heater 14, to an outlet stack, not shown. The walls of the furnace are lined with steam-generating tubes 18a ....18d forming four circuits, in paralell, between a lower water supply drum 20, with manholes 60 and, with interposition of headers 22, an upper steam - and - water drum 24. Downcomers 25a ... 25d, Fig. 6, depend from the drum 24 to circulating pumps 26, 27, 28 which are connected, as shown, the centre pump 27 to the ends of the drum 20, through conduits 27a, 27b, and the end pumps to the middle portion of said drum through conduits 26a, 26b and 28a, 28b respectively. The water supply to the several circuits is proportioned by means of orifice members 63, Figs. 8 and 11, which have orifices 66 of predetermined size formed therein and are force-fitted into adaptors 64 mounted on the inlet ends of the tubes 18a ...18d of said circuits, the adaptors with their orifice members being secured in place by channel members 68 which, preferably, are common to several adjacent tubes of a circuit and are attached to the drum by studs 70 welded to the inner surface of the latter. Clogging of the orifices 66 is prevented by strainers 72, 73. The boiler is supported wholly from a framework 56 by hangers 54.