Nozzle for producing thin-walled annular billet

The invention discloses a nozzle for producing a thin-walled annular billet, and relates to the field of thin-walled annular continuous casting billets. The nozzle comprises an upper flange, an uppertube, a front protrusion, a transition section and a water outlet, wherein the upper flange with a through hole in the middle is in a disc shape, the plane of the upper flange is connected to a tundish lower water outlet flange, the upper flange is connected with the upper tube below the upper flange, the upper tube is connected to the upper part of the transition section, the water outlet is connected to the lower part of the transition section, and the whole water outlet is in a banana shape. The front protrusion is arranged at the front of the water outlet and arranged on a single side. Thewater outlet has a banana shape, the front protrusion is arranged at the front of the water outlet, larger space is reserved with a crystallizer, and the problems of production safety of the thin-walled annular continuous cas