ES289566A1 - Fluid machines - Google Patents

Abstract

An hydraulic turbine, pump or pump-turbine comprises a runner 11 having shrouds 16, 17 surrounded by a stator 12 to form annular spaces 20, 30 to which compressed air is supplied through restricted pipes 25, 35 so as to exclude leakage water from the spaces and thus improve efficiency. Labyrinth seals 19, 29 define the radially inner limits of the spaces 20, 30 respectively and are supplied with leakage water under pressure through pipes 21, 31 from collecting chambers 24, 34 so as to prevent the escape of air from the spaces. Excess air or water collects in chambers 27, 37 and exhausts through pipes 28, 38. In a modification, Fig. 4 (not shown), pairs of chambers 24, 27 and 34, 37 are each replaced by a single chamber from which water and air flow through pipes 21, 31 to seals 19, 29 respectively. In a further modification, Fig. 7 (not shown), a runner 61 having a shroud 67 is mounted within a stator 62 to form an annular space 70. Seal 69 is fed with high pressure leakage water from chamber 74 through pipe 71 and compressed air is supplied through pipe 75. The leakage water finally discharges from chamber 77 through holes 80 to the low pressure side of the runner at 65. Air discharges through a restricted pipe 78. Further modifications are described with reference to Figs. 8 to 11, including such features as slightly modified seals and an additional sealing water supply reservoir. Orifices such as 26, 36, may be variable and restrictions may be provided in pipes such as 21, 31.