GB480172A - Improvements in or relating to steam superheaters for marine and like smoke tube boilers - Google Patents

Abstract

480,172. Steam superheaters. SUGDEN, Ltd., T., and HALL, A. Aug. 17, 1936, No. 22578. [Class 123 (iii)] The elements of steam superheaters disposed in return-tube boiler combustion chambers consist of two multiple-loop tubes of heat resisting alloy lying in parallel vertical planes with bifurcating portions 21, 22 welded to single tube inlet and outlet portions 9, 10 leading to exterior headers 1, 2, the bifurcations and welds lying next to the water-cooled combustion chamber back 5 and protected from radiant heat by the element loops which extend below them. The tube bends are arranged so that saturated steam occupies the front lengths most exposed to radiant heat. The elements are slung from a girder 7 bolted to the top plate 8 by means of inverted U-shaped slings 30 suspended by bolts 28 and having lugs 31, 32 taking beneath the bends 16, 15, and a cross pin 33 beneath the bends 14. The pin passes through elongated holes in the sling to which it is welded when in supporting position. Upper and lower bands 36, 37 retain the bends in position band 36 having inwardly projecting fingers and band 37 a spacing frame with outwardly projecting fingers. The bands may be supported by lugs welded to the tubes. The headers which are enclosed in a three-part casing 50 comprise a solid forging bored to provide a longitudinal steam chamber 43 and rightangle passages 45 extending from the jointing face to the chamber. Holes drilled on each side of the passages 45 accommodate bolts retaining the element clamp members 48, the header having a rebate 44 for reception of the bolt head or nut. One tube of each element may be secured to a transverse bar 53 abutting against the side walls of the combustion chamber.