DEVICE FOR RECIRCULATING AN AT LEAST PARTIALLY GASEOUS COMPOSITION CONTAINING HYDROGEN AND FUEL CELL SYSTEM

The present invention relates to a device () for the recirculation of an at least partially gaseous composition containing hydrogen, wherein the device () is a dry rotary pump comprising a first rotating shaft () and a second rotating shaft () driving respectively a first piston with claws () and a second piston with claws () in rotation in a pumping chamber () comprising an inlet orifice () and an outlet orifice () for the gaseous composition, the first rotating shaft () and the second rotating shaft () being configured to be driven in rotation by a drive system () situated in a gear chamber (), wherein the device () comprises a first pair of seals () and a second pair of seals (), each comprising a first shaft seal () and a second shaft seal (), the first pair of seals () being provided around the first rotating shaft () and the second pair of seals () being provided around the second rotating shaft () between the pumping chamber () and the gear chamber (), wherein the device () comprises a pressure equalization chamber () which is in fluid connection with a gap () present between the first shaft seal () and the second shaft seal () of the first and of the second pair of seals () to regulate the pressure in the gap (), wherein the gear chamber () is in fluid connection with the gap (), and wherein the pumping chamber () is in fluid connection with the first shaft seal () of the first pair of seals () and with the first shaft seal () of the second pair of seals () by means of a pulsation attenuation chamber (). The present invention also relates to a fuel cell system () comprising a device for recirculation according to the present invention.