Tandem seal

Abstract

A pair of primary and secondary mechanical seals are arranged tandem in an axial direction around a rotating shaft in a space between the rotating shaft and a housing having a shaft sealing part. The center or intermediate liquid is sealed into a center room or intermediate chamber between both mechanical seals. The center liquid has an amount that is less than the volume of the center room and enough to soak one part of rotating elements of the secondary mechanical seal. The gas vent line is provided with the housing of the shaft sealing part. The gas vent line faces and opens to the center room. The baffle plate is provided with the housing of the shaft sealing part. The baffle plate intersects a circumferential direction of the center room. Thus, when rotating the rotating shaft, the center liquid is stirred and scattered by collision with the baffle plate to lubricate the sealed slide surface. The vaporized gas from the sealed liquid, which is leaked from the primary mechanical seal to the center room, does not collect in the inner circumferential part of the center room. It does not form a gas zone. It is discharged from the gas vent line.

Dependencies are inferred from the claim text.