Turbo compressor with multiple stages of compression devices

1. A turbo compressor comprising:

multiple stages of compression devices arranged in series with respect to a gas passage, each of the compression devices comprising an impeller that rotates about an axis;

an oil tank capable of supplying lubricating oil to a sliding portion of the compression devices;

a partitioned intermediate space formed so as to communicate with the gas passage on an upstream side of the compression devices, gaps between the partitioned intermediate space and the gas passage, the gaps being configured to permit fluid communication between the intermediate space and the gas passage;

a pressure equalizer provided so as to continuously connect the partitioned intermediate space and the oil tank; and

a barrier plate between the gaps, the pressure equalizer having an open end in the partitioned intermediate space,

wherein the turbo compressor is configured to conduct a compression process sequentially by suctioning the gas in the gas passage.

2. The turbo compressor according to claim 1 ,

wherein the partitioned intermediate space have an annular shape with the axis as its center, and

an open end of the pressure equalizer in the partitioned intermediate space is directed towards a tangential direction of the annular shape of the partitioned intermediate space.

3. The turbo compressor according to claim 1 , further comprising:

a flow rate adjusting unit which adjusts a suction amount of the compression devices in the gas passage on an upstream side of the compression devices; and

a drive section of the flow rate adjusting unit accommodated within the partitioned intermediate space.