| 摘要 |
PURPOSE:To prevent the flow of steam from reaching a rotor shaft and eroding it, by providing communication passages in the inner ring, plate and outer ring of a nozzle section so that the steam which would flow along the inside of the inner ring of the nozzle section is conducted to the vicinity of the outlet port of a casing through the communication passages. CONSTITUTION:The inner ring 8 of a nozzle section is provided with circumferential grooves 12 located near the inside of the ring and concentric to each other and is provided with Y-shaped passages 13, the number of which is equal to that of nozzle plates 9 and each of which has two branch parts opened in the bottoms of the circumferential grooves 12 and connected to each other in the nozzle plates 9 outside the inner ring 8 of the nozzle section. Each nozzle plate 9 is provided with a passage 14 connecting to the passage 13 and extending in the diametral direction of a nozzle diaphragm 10. The outer ring 6 of the nozzle section is provided with drain passages 15 connected to the passages 14 and opened near the outlet ports 11 of a casing 1. Since the pressure at the outlet opening of the drain passage 15 is lower than that at the circumferential grooves 12, the steam entering into the spaces between the inner ring 8 of the nozzle section and rotor discs 3 is drained through the passages 13-15. |
