SEAL DEVICE AND ROTARY MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a seal device and a rotary machine capable of preventing deterioration of dynamic characteristics of a seal portion by sufficiently reducing a swirl flow inflowing in the seal.SOLUTION: A seal device restrains the inflow of a fluid G in a clearance g formed between an outer peripheral surface 2a of a rotor 2 and an inner peripheral surface of a stationary body opposite to the outer peripheral surface 2a. The seal device comprises: an annular seal body 11 disposed to face the outer peripheral surface 2a of the rotor 2; and a swirl breaker 12 disposed at the upstream side end part of the seal body 11 for restraining a swirl flow S flowing in a circumferential direction of the rotor 2. In the seal device, the swirl breaker 12 includes a plurality of recesses 13 opened on an upstream side and on the rotor 2 side and juxtaposed in a circumferential direction, and at least one of the recess 13 and the outer peripheral surface 2a of the rotor 2 opposite to the recess 13 includes a longitudinal vortex promotion mechanism 20 that accelerates generation of a longitudinal vortex T flowing from the outer peripheral surface 2a side of the rotor 2 toward the upstream side of the recess 13.