| 摘要 |
789,197. Turbines. BRITISH THOMSON-HOUSTON CO., Ltd. Jan. 6, 1956, No. 551/56. Class 110 (3). A high temperature elastic fluid turbine has the parts of the rotor or casing which support the blades cooled by a fluid which passes from an annular chamber at the downstream end of the turbine through continuous axial passages formed in the blade roots and spacers and is then discharged into the working fluid entering the first stage. The turbine rotor 1 has axial dovetail slots 2 in which are inserted blades 3 and spacers 4. The blade roots and spacers have aligned axial holes 5 through which the coolant is passed. Pipes 6 are fitted in the holes 5 to ensure fluid tightness. In front of the first stage blades, end spacers 7 having recesses 8 are fitted. The recesses 8 collect the coolant and divert it into the stream of working fluid at the inlet side of the first stage. At the exhaust end of the rotor, a pair of discs 9, 10 form a space 13 to which the coolant is supplied from the bore 17. The coolant may be air taken from a compressor supplying the working medium in which case, the air is supplied to the bore 17 through an orifice 21, the size of which determines the flow. A shield 20 reduces the transfer of heat from the rotor to the cooling air. Cooling air may also pass over the surface 22. The rotor may be grooved at 23. The blade roots may be provided with shoulders 24 so that part of the centrifugal force on the blades may be transferred to the spacers. In a modification, the tubes 6 may be replaced by short tubes located at the joints. The application of the invention to a casing is also described. The inlet chamber may be supplied with coolant through axial passages in the rotor or casing which are supplied with coolant at the inlet end of the turbine. In a steam turbine saturated steam or steam at low superheat may be used as a coolant. |
