GB612746A - Improvements in water-tube steam boilers - Google Patents

Abstract

612,746. Water-tube steam boilers. BABCOCK & WILCOX, Ltd. May 31, 1946, No 16590. Convention date, June 2, 1945. [Class 123(ii)] In a water-tube steam boiler comprising a furnace chamber 17, Fig. 4, which extends from a front wall 10 fitted with burners 19 to a rear wall 12, and a passage 18 which is separated from said furnace by a partition 16, terminating short of the rear wall 12 to provide an entrance 21 thereto, and locates steam-generating tubes 25, a baffle 45 is fitted at the end of the partition to obtain a more uniform gas flow through the entrance 21. Both the partition and baffle preferably comprise a plurality of closely-spaced tubes 25a, 45a respectively and the baffle makes an angle of at least 90 degrees with said partition. In one modification, this angle is 150 degrees, and in a further construction the baffle is in the form of a series of narrow baffles 41, each comprising three water tubes 41X, 41Y, 41Z, Fig. 2, which extend transversely into the furnace in mutually-stepped relationship from adjacent the end of the partition to a location spaced from the entrance 21 and adjacent the wall 12. The steam generating tubes 25 and the tubes lining the boiler walls 10, 12, 13, 14, also the tubes of the partition 16 and baffle 45, extend between an upper steam-and-water drum, not shown, and a lower water drum 24, and the tube bank 25 is traversed by baffles 28, 29 which divide the passage 18 into three serially connected passes 31, 32, 34, the last pass being provided with a gas outlet. The tubes 25c of the bank 25 within the passes 32, 34 are of lesser diameter and less widely spaced than the corresponding tubes 25b in the pass 31 which are arranged in two spaced groups to accommodate an intermediate superheater 36 comprising inlet and outlet headers 37, 38 connected by looped tubes 36a, and the tubes 25b on the inlet side of the superheater are preferably spaced as shown. Specification 496,488 is referred to.