Post-combustion device

The ring (19) has burner ring with an upstream annular envelope forming a gorge in which a fuel injection harness (4) is arranged. The annular envelope has an upstream surface that is in contact with a flow of exhaust gas. Each of multiple ring sectors has a jointing ferrule for receiving a fuel inlet (35). A downstream annular envelope sector (5) is arranged downstream of the harness to protect the harness. An independent claim is also included for a jet engine having a post-combustion device.