Gas turbine stationary blade double cross type seal device

摘要

Seal plates for gas turbine stationary blade inner shrouds are made in a double cross type seal structure with a view to enhance sealing ability. Seal plates 1, 2 are mutually lapped and disposed in a turbine axial direction between inner shrouds 12 of stationary blades 11. End portion seal plate 5 is lapped on an end portion of the seal plate 2 and end portion seal plate 6 is lapped under an end portion of the seal plate 1. All these seal plates are fitted with their side end portions being inserted into groove 9a provided in the inner shrouds 12. Seal plates 3, 4 and seal plates 7, 8 engaged with the seal plates 3, 4 are also fitted between flange portions of the inner shrouds 12 with their side end portions being inserted into grooves 10a, 10b and grooves 9b, 9c, respectively. All the seal plates 1 to 8 are fitted between mutually opposing inner shrouds in turbine circumferential direction so as to cover cavity 24 between mutually adjacent shrouds, so that gaps between engaged portions of each seal plate and between the seal plates and seal ring support ring 13 are eliminated, thereby seal air 20 is prevented from leaking from the cavity 24.