Patent ID: 9644636
Date: 2017-05-09
CPC Classifications: F01K,F04D,F16J

Claim:
1. A centrifugal steam compressor having a shaft seal system to supply sealing water to a centrifugal compressor which rotate-drives an impeller attached to a rotary shaft to compress gas including steam, comprising: radial bearings that rotate-support the rotary shaft at its both ends; a thrust bearing that supports a thrust force generated in the rotary shaft; and two seal means provided between the respective radial bearings and the impeller, wherein the respective seal means have a mechanical seal provided in three stages in an axial direction, and a common primary sealing water chamber to supply the sealing water to first-stage and second-stage mechanical seals positioned on the impeller side, and a secondary sealing water chamber to supply the sealing water to a third-stage mechanical seal positioned on the device-outermost side, are provided, wherein the primary sealing water chamber is supplied with high-pressure sealing water via a first pressure regulating valve, and the secondary sealing water chamber is supplied with low-pressure sealing water via a second pressure regulating valve, and wherein a circulating water reservoir that stores circulating water, a positive displacement pump that sucks the circulating water from the circulating water reservoir, and is capable of supplying the sealing water, at pressure higher than the sealing water supplied to the primary sealing water chamber, to the first and second pressure regulating valves, an accumulator provided between the positive displacement pump and the first and second pressure regulating valves, a return piping that returns the sealing water, which water-seals the respective stage mechanical seals and returns from the primary sealing water chamber and the secondary sealing water chamber, to the circulating water reservoir, and depressurization means interpositioned in the middle of the return piping, are provided.