Underwater facility for gas/liquid separation

An underwater facility for gas/liquid separation of a multiphase hydrocarbon mixture, said multiphase hydrocarbon mixture comprising a gas phase and at least one liquid phase,

• said underwater facility comprising:
• an underwater supply line configured for supplying said multiphase hydrocarbon mixture;
• a longitudinal separating chamber configured and intended to be installed approximately vertically, said separating chamber having a lower end, and an opposite upper end, and an intermediate separating zone located between the two opposite ends;
• said separating chamber further comprising an injection line connected to said supply line and extending longitudinally inside said intermediate separating zone, said injection line having a tubular wall and having a free end having an axial opening inside said separating chamber, configured to allow said at least one gas phase to escape to said upper end of said separating chamber while allowing said at least one liquid phase to go to said lower end;
• wherein said tubular wall is continuous for being impervious to said multiphase hydrocarbon mixture;
• wherein said upper end of said separating chamber having a first prolongation;
• and an exhaust pipe for said at least one gas phase extending in the first prolongation of said upper end of said separating chamber;
• wherein said lower end of said separating chamber having a second prolongation;
• and a recovery pipe for said at least one liquid phase extending in the second prolongation of said lower end of said separating chamber;
• and
• wherein the exhaust pipe and the recovery pipe meet in an umbilical including several fluid lines, said exhaust pipe being connected to a first set of one or more fluid lines of said umbilical and said recovery pipe being connected to a second set of one or more fluid lines of said umbilical which are different from the fluid lines of said first set.