GB238221A - Improvements in and relating to elastic fluid turbines - Google Patents

Abstract

238,221. British Thomson-Houston Co., Ltd., (Assignees of Wirt, H. L.). Aug. 11, 1924, [Convention date]. Exhaust, treating.-In order to effect a conversion of velocity into pressure of the exhaust fluid, an elastic fluid turbine is provided with an ex. haust hood in which is provided an annular expanding portion having the difference between the inner and outer radii at its admission end equal to substantially the length of the buckets of the last wheel and a length equal to substantially twice the length of such buckets, the annular portions merging into a plurality of branches, which diverge gradually from the centre line of the turbine and so as to acquire a total cross. sectional area equal to at least twice; the annular admission area in a distance equal to about two last stage wheel-diameters. The last row of bucket wheels 7 is mounted on a shaft 6, arranged in a tubular shell 9. The annular passageway 12, after extending a distance equal to about two bucket lengths, divides into branches 13, 14 which terminate in openings 15, 16 connected to condensers 19, 20. In order that the branches curve so as to direct the stream of exhaust fluid gradually and at low velocity away from) the centre line of the turbine, the angle should not exceed 12‹ between successive chords drawn parallel to the direction of flow and equal in length to the length of the buckets 7. The branches are preferably cut off at an angle, as shown, and the exhaust fluid directed into the condensers by stationary guide blades 21 that are shaped to provide an expanding cross-section. The condenser tubes 19a extend at an angle with the centre line of the passageway through which the exhaust fluid flows. Each branch is divided vertically at 22, and the upper part 23 is adapted to be removed without disturbing the condenser connection.