The invention relates to a fluid compression apparatus (1) comprising a sealed
enclosure (13) for containing a cryogenic fluid bath (16), a first (3) and a second compression chamber (4), an inlet
system (2) for the first chamber (3), a
transfer system (6) from the first (3) to the second (4) chamber, the apparatus (1) further comprising a communicating
discharge port (7) for the outlet of
compressed fluid from the second chamber, the apparatus (1) further comprising a
discharge port equipped with a valve (9) for the
discharge of the first compression chamber (3) into the bath (16) to allow excess liquid to escape during fluid compression in the first chamber (3), the discharge port communicating with the
enclosure (13) via at least one flow restrictor (10) configured to attenuate the velocity and / or intensity of the discharged liquid flow by limiting its pressure drop. Abstract figure: Fig. 1