GB1338259A - Turbines - Google Patents

Abstract

1338259 Vapour turbines REYROLLE PARSONS Ltd 10 June 1971 [15 June 1970] 28905/70 Heading FIT A multi-flow steam or other vapour turbine has means for extracting vapour and entrained liquid from one main flow of the turbine and, after removal of the liquid, returning the vapour to a second main flow of the turbine at a point where the pressure is only slightly lower than at the extraction point. When applied to a double flow turbine having an annular entry 14 for steam from a nuclear reactor, steam and entrained water are extracted from the left-hand flow at a point 27 following the fourth rotor blade stage 7. The mixture flows into an annular chamber 29 and is led by a pipe (30), Fig.2 (not shown) to an external steam/water separator (31), the dried steam then passing through a pipe (32) to an annular chamber 33 surrounding the right-hand flow, whence it rejoins the latter at 28. The flow paths are designed so that the pressure at 28 is about 5% less than that at 27, e.g by making the blades of corresponding stages of different lengths or the flow passages of different widths. Similarly steam and water from chamber 34 surrounding the right-hand flow is passed through a separator (35), the dried steam rejoining the left-hand flow via chamber 36. Additional extractions and returns may be provided. In a modification the steam/ water separator may be contained within stator casing 2, in which case baffle 37 is omitted. The extracted water is fed to a feed heater via a flashbox.