Compressor

Claim 1

A compressor for a corrosive fluid, comprising a housing having an inlet and an outlet, a shaft mounted for rotation in the housing and extending through a wall of the housing, an impeller mounted on the shaft for rotation in the housing between the inlet and outlet, and means sealing between the housing wall and the shaft against tHe escape of compressed corrosive fluid from the housing, the sealing means comprising a first ring being sealed about and mounted for rotation with the shaft, the first ring having an end face, an annular cartridge having an inner wall and an end wall mounted about the shaft and fixed and sealed to the housing wall such that compressed fluid is confined to passage between the cartridge inner wall and the shaft, a second ring of carbon disposed between the inner and outer cartridge walls and including an inner face spaced from the outer face of the inner cartridge wall and an end face, the second ring being mounted for axial movement with respect to the cartridge but against rotation with respect thereto, a spring in the cartridge urging the end face of the second ring into contact with the end face of the first ring to form a rotary sliding seal therebetween during rotation of the shaft, the outer face of the inner cartridge wall having a substantially uniform diameter, a resilient sealing ring disposed between and in sealing engagement with the outer face of the inner cartridge wall and the inner face of the second ring, and a sleeve mounted closely about said outer face of the inner cartridge wall and between the resilient sealing ring and the cartridge end wall in order to limit movement of the resilient ring toward the cartridge end wall so that, upon wear of the end face of the second ring, only portions of the inner face of the second ring that have been protected from exposure to the compressed corrosive fluid will sealingly engage the outer surface of the resilient ring.