Thrust-balancing wet gas compressor

A contra-rotating compressor for compressing a process fluid, comprising:

• a housing configured to receive an inlet flow of the process fluid at an inlet pressure and output an outlet flow of the process fluid at an outlet pressure;
• a first shaft assembly disposed in the housing and rotatable about a longitudinal axis, the first shaft assembly comprising an outer shaft and a first plurality of impellers coupled to the outer shaft, wherein the outer shaft comprises a final stage that includes a final impeller of the first plurality of impellers;
• a second shaft assembly disposed in the housing and rotatable about the longitudinal axis, the second shaft assembly comprising a second plurality of impellers interleaved with the first plurality of impellers;
• and
• a chamber positioned axially between the final stage and the second shaft assembly, wherein the chamber is configured to be in fluid communication with the inlet flow of the process fluid at the inlet pressure.

A method for compressing a process fluid, comprising:

• (a) flowing an inlet flow of the process fluid into a housing at an inlet pressure;
• (b) rotating a first shaft assembly disposed in the housing and comprising a first plurality of impellers about a longitudinal axis in a first rotational direction;
• (c) rotating a second shaft assembly disposed in the housing and comprising a second plurality of impellers interleaved with the first plurality of impellers about the longitudinal axis in a second rotational direction opposite the first rotational direction;
• and
• (d) applying an axially directed pressure force to each end of the second shaft assembly with the process fluid at the inlet pressure.