External transition spray gun of drying tower

The utility model relates to the technical field of high-pressure spray guns, in particular to an external transition spray gun of a drying tower, which is provided with a normally closed high-pressure ball valve, the high-pressure ball valve is mounted on a high-pressure pipeline in parallel and is sequentially connected with an external spray gun and a plurality of internal spray guns through high-pressure hoses, and the internal spray guns are mounted on the inner side of an air distributor of the drying tower. An opening threshold value is preset for the high-pressure ball valve; when the drying tower is started and the pressure value is smaller than the opening threshold value, the external spray gun is opened corresponding to the high-pressure ball valve, and materials enter the external spray gun and are sprayed outside the tower; when the pressure value is larger than or equal to the opening threshold value, the built-in spray gun is opened corresponding to the high-pressure ball valve, materials ente