Turbo type fluid machine and dry gas seal for use therefor

Abstract

Abnormality in an amount of a working gas leaked from between a rotating ring adapted to rotate with a rotor and a stationary ring of a turbo fluid machine is detected by a pressure switch and a flow meter, which are provided in a primary seal vent line, the working gas leaking from sealing surfaces of the labyrinth seal and the secondary dry gas seal, together with a purge gas purged to the space from outside is discharged outside the machine from a flow passage via a space. When abnormality generates in the secondary dry gas seal, a control valve provided in the purge gas line operates to secure a flow rate in the purge gas line, so that a flow rate detected by the flow meter provided in the purge gas line increases, and thus abnormality in the secondary dry gas seal is detected.

Dependencies are inferred from the claim text.