GB949024A - Improvements in forced recirculation steam generators - Google Patents

Abstract

949,024. Forced flow steam boilers. H. VORKAUF, and LA MONT INTERNATIONAL ASSOCIATION Ltd. Dec. 11, 1962 [July 26, 1962], No. 46668/62. Heading F4A. In a forced recirculation steam boiler having groups of adjacent, substantially equally heated evaporating tubes connected to respective distributer headers to which water is supplied by a circulating pump through throttling tubes having a comparatively high pressure drop, such a boiler being described in Specification 789,431, differential expansion between the tube groups is taken up by providing flexible throttling tubes between the discharge main receiving the pump delivery and the individual distributer headers. In the form shown, the boiler has a drum 1 suspended by hangers 3 from the steelwork 2, a downcomer 4 conveying the circulating water to a pump 5 which delivers it to a discharge main 9<SP>1</SP> supported on bearers 10. Throttling tubes 11 connect the main 9<SP>1</SP> to headers 7, each supplying a group of evaporator tubes 6. All the tubes 6 discharge into a header 8 suspended from the steelwork and connected to the drum. The tubes 11 are made flexible by providing them with U-bends as shown so that they may take up the expansion and contraction of the tube groups. In a modification, the separate headers 7 may be replaced by a single internally partitioned header. In a further modification, the discharge main is hung from the headers 7 by the tubes 11 and by sprung suspension means.