GB995643A - Improvements in or relating to multistage steam turbines and installations thereof - Google Patents

Abstract

995,643. Steam turbines. LICENTIA PATENT - VERWALTUNGS -G.m.b.H. Dec. 27, 1961, No. 46287/61. Heading FIT. A multistage axial flow steam turbine has stator guide blades formed with radial passages for the flow of heating steam therethrough mounted at the steam entry to a ring of rotor blades and arranged to act as surface heat exchangers for the addition of heat to the steam flowing towards the rotor blades. Steam turbine guide blades 1 extend radially between, and are welded at their ends to, inner and outer rings 5, 6, Fig. 1. Two radial heating channels 11 in each guide blade 1 are formed by grooves 12, Fig. 2, cut in the concave side of the main body 13 of the guide blade, a cover plate 2 being welded to the axially outer edges 14 of the grooves. The heating channels 11 are connected respectively to two separate grooves 3 formed in the inner surface of the outer ring 6 which extend over the entire periphery of the stage and serve as delivery and discharge connections for the heating steam, which is delivered through one of two pipes 4 from the live steam pipe feeding the turbine, or from the heating steam discharge line or an extractor steam pipe of a preceding stage. Channels 11 of each blade communicate at their radially inner ends through an axial groove 15 in ring 5. The live steam feeding the turbine may be wet steam from a nuclear power plant. Steam from the other pipe 4 is led off to the condenser of the plant, to a subsequent guide blade assembly, to a feed water pre-heater, or to a further heat exchanger.