GB880230A - Improvements in or relating to steam generators - Google Patents

Abstract

880,230. Heating steam boilers by hot gases. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Aug. 11, 1960 [Sept. 18, 1959], No. 31867/59. Class 123(2) A steam generator comprises tube assemblies 5 located in an annular gas passage 4 which is, e.g. for the carbon dioxide coolant of a nuclear reactor and is defined by a cylindrical pressure vessel 2 and a coaxially arranged inner conduit 3 accommodating longitudinal headers 8 which interconnect the tube assemblies 5 and extend through an aperture 6 in the vessel 2 closed by a cover 7 pressure balance across the conduit 3 being obtained by an orifice 9 in the conduit 3. The heating gas enters and leaves the vessel 2 respectively through inlet and outlet ducts 29, 30 pressure relief being obtained by a valve 10 in the cover 7. The groups of tube assemblies, providing economiser, evaporator, superheater, and reheater sections and each comprising a sector-shaped unit of close-packed, interconnected, U-tubes, are enclosed by a light casing 26 having an extension 28 sealing the lower end of the vessel 2. The feed and return tubes of the assemblies 5 penetrate curved plates 13 which form the conduit 3 the upper end of which is extended by a tubular baffle 11 which incorporates an expansion bellows 17 and has a flanged end 16 extended to the walls of the vessel 2. A drain pipe 19 leading from the headers 8 extends through the vessel 2 and through a dome 18 which closes the lower end of the conduit 3 and has a drain pipe 22 projecting through the vessel 2. The cover 7 is penetrated by stub pipes 25 which locate the upper ends of the headers 8.