| 摘要 |
645,258. Gas turbines. BUCHI, A. May 9, 1947, No. 12597. Convention date, May 10, 1946. [Class 110(iii)] A gas turbine rotor 14, Fig. 1, is followed by a diffuser 15 the walls of which are surfaces of rotation generated by diverging lines 16, 17. The down-stream parts of these lines are straight and one of these parts may be radial. The gases are expanded in the turbine to below atmospheric pressure and are brought up to that pressure in the diffuser. In the construction shown in Fig. 1, the gases enter through passages 4, 5 separated by diametral walls and the separation may be continued through the diffuser. The flow through the turbine blading has both radial and axial components. The diffuser delivers radially into a chamber 20 of constant outer diameter but with an axial dimension which increases on both sides of the diameter from the lowest point to the exhaust opening 13 at the top. The casing comprises three portions 8, 11, 10 and the portion 11 may be divided axially. Cooling fluid is supplied to cavities 9 and 12. Cooling air is drawn from the delivery scroll 10 of the compressor 2 through passages 21, an annular space 22 and a packing 24 to the turbine delivery. The flow through the turbine may be axial and the diffuser may deliver axially into a volute chamber with a constant radial dimension and an increasing axial dimension. The volute chamber may be followed by a diffuser with a straight axis. The diffuser 15 may be preceded by a convergent portion produced by a hump 29, Fig. 9, or, by a parallel portion 34, Fig. 10, connected to the diffuser 15 by a constricted portion 35. The diffuser passages may be divided by a number of axially extending partitions.
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