Nozzle of polysilicon reduction furnace

The utility model provides a nozzle of a polysilicon reduction furnace, comprising a bottom plate, an external sleeve and an internal spray head, wherein the bottom plate is connected with a bottom disc of the reduction furnace and plays a role in supporting the nozzle; the bottom plate is provided with an air feeding pipe; the air feeding pipe is a direct passage by which the working gas leads to the spray head; the external sleeve is connected with the air feeding pipe; the upper surface of the external sleeve is provided with central through holes that pass through the external sleeve in the longitudinal direction; the internal spray head is connected with the external sleeve, and the external surface of the internal spray head is cylindrical or conical; the upper surface of the internal spray head is provided with central through holes that pass through the internal spray head in the longitudinal direction; the external surface of the internal spray head is provided with a plurality of helical troughs that are distributed uniformly; and the troughs and the internal walls of the external through holes form a helical airflow passage. The air feeding pipe, the external sleeve and the internal spray head form the airflow passage with gradually reduced caliber so that the working gas can achieve the appointed height; the helical airflow passage can reduce the flowing speed of the gas; therefore, the airflow at the lower end of a silicon rod can be refreshed, the lower end of the silicon rod can not be impacted, and the production efficiency and quality of the product polysilicon is improved.