GB346242A - Improvements in or relating to steam generators and superheaters for compound locomotives - Google Patents

Abstract

346,242. Compound steam boilers. SCHMIDT'SCHE HEISSDAMPF-GES., 2, Rolandstrasse, Wilhelmsh÷he, Cassel, Germany. July 18, 1930, No. 21824. Conven. tion date, Aug. 31, 1929. [Class 123 (ii) and 123 (iii).] Locomotive boilers comprise a high pressure water-tube boiler 1 forming the firebox and a flue tube boiler 2 adapted mainly to preheat the feedwater of the high pressure boiler, the flue tubes 3 containing the tubes of more than one superheater and the ratio of the superheater heating surface to the water heating surface of the flue tube boiler being greater than one. In the form shown each flue tube accommodates six superheater tubes and two flue tube superheaters 4, 5 are provided, live steam from the high pressure boiler passing through the first, then through the heat-supplying coil of an interstage superheater 6 and then through the second. A small superheater for the low pressure steam may be located in the smoke box or in a vertical row of the flue tubes, or the steam may be mixed with exhaust high pressure steam in the interstage superheater. The latter may be omitted, the exhaust steam being reheated in a flue tube superheater after passage: through an oil separator.