Fluid compression apparatus and method

A fluid compression apparatus with a plurality of compression stages, the fluid compression apparatus comprising:

• a sealed enclosure configured to contain a bath of cryogenic fluid having a liquid phase, the upper part of the sealed enclosure configured to contain a gas headspace;
• a first compression chamber;
• a second compression chamber;
• an intake system that communicates with the first compression chamber and is configured to allow fluid to enter said first compression chamber;
• a transfer system that communicates with the first and the second compression chambers and is configured to allow the transfer of fluid pre-compressed in the first compression chamber to the second compression chamber;
• a communicating discharge orifice that communicates with the second compression chamber and is configured to allow fluid compressed in the second compression chamber to leave,
• wherein the intake system comprises one or more valves configured to ensure fluid to be compressed enters the first compression chamber during an intake phase and to prevent fluid from leaving in the compression phase;
• an overflow discharge orifice allowing communication between the first compression chamber and the bath so as to let surplus liquid trapped in the first compression chamber leave during compression of fluid in the first compression chamber;
• a discharge valve configured to control the discharge of liquid via the overflow discharge orifice and to prevent fluid from entering the first compression chamber via the overflow discharge orifice;
• wherein the overflow discharge orifice communicates with the sealed enclosure via at least one flow retarder configured to attenuate the speed and/or intensity of the discharged liquid flow by limiting a pressure drop of the discharged liquid.