Improved brush-seal designs for turbines and similar rotary apparatus

摘要

An axial flow turbine is provided with retractable packing and brush seals between stages. The retractable packing is provided with separate packing segments (201) which form a ring when closed during normal operation and expand to a larger clearance during start-up and shut-down. A brush seal segment (217,219) is provided on each packing segment (201), such that when segments are closed during normal operation, the brush seal likewise forms a ring. The ends of the packing segments are cut along radii extending from the central shaft, and the ends of the brush seal segments are canted so as not to be parallel with the ends of the packing segments in which they lie.