GB551483A - Improvements in or relating to boilers - Google Patents

Abstract

551,483. Water-tube steam boilers. BABCOCK & WILCOX, Ltd., and ZOLLER, R. E. Aug. 22, 1941, No. 10709. [Classes 123 (ii) and 123 (iii)] Furnace gases flow from a water-tube lined combustion chamber 4 through parallel passes 1, 2, 3 containing vertical water tubes 5, 6, 7 connected to upper and lower drums 9, 8, and, in the end passes, a superheater 11 and a reheater 12. The gas flow in each pass is controlled by separately operated dampers 16, 16<1> at the top of a partition separating the flow through the lower part of the tubes from the flow through the upper part. The combined gas streams escapes through a feedheater 18 and an air heater 20. The gas passes 1, 2, 3 are separated by walls 33, 34 containing downcomers. The economizer may be divided by plates forming extensions of the walls 33, 34, the flow of gases through the passes being controlled by dampers beyond the economizer. Water tubes 11, 12, 13 in front of the gas passes, and the furnace wall tubes are connected to a water drum 14 at the bottom of the bustion chamber. Air is conducted from the air heater through a duct 58 passing down the back of the combustion chamber into a space 59 below chamber floor and opening into a wind box 57. The U-shaped superheating or reheating tubes 12, Fig. 5, pass through holes in spacer plates 42 positioned by rods 43 secured to lugs 45 on the header 51.