Multi-stage centrifugal compressors

摘要

The invention relates to an improved multi-stage centrifugal compressor (10) comprising at least four centrifugal compression stages (11,12,13,14), each including an impeller. The impellers of one pair of the stages (12,13) are mounted on a first shaft (23) coupled to a first high speed direct drive motor (16), and the impellers of another pair of the stages (11,14) are mounted on a second shaft (24) coupled to a second high speed direct drive motor (15). The speed of the first and second motors is controlled by at least one drive (25) such that the impellers are all driven at the same speed.

主权项

1. A multi-stage compression system comprising at least four centrifugal compression stages, each including an impeller, one pair of the stages are mounted on a first shaft coupled to a first high speed direct drive motor, and another pair of the stages are mounted on a second shaft coupled to a second high speed direct drive motor, the speed of the first and second motors being controlled by at least one drive such that the impellers are all driven at the same speed, wherein one compression stage on the first shaft and another compression stage on the second shaft form a pair of first compression stages, said pair of first compression stages are mounted in parallel to each other; the other compression stages are a second and third compression stage; neither the second nor third compression stage is upstream of either of the compression stages of the pair of first compression stages; the second and third compression stage are mounted in series with each other, with the third stage downstream of the second stage, and the second and third compression stages are downstream of both the compression stages of the pair of first compression stages.