Air supply pipeline of circulating fan of raw material mill

The utility model relates to the technical field of raw material mills, in particular to an air supply pipeline of a circulating fan of a raw material mill. According to the technical scheme, the air supply pipe comprises a shell, a threaded structure, an insertion plate, a rotating structure, a first threaded disc and a second threaded disc, air supply pipe bodies are fixed to the two sides of the shell correspondingly, a second groove is formed in the upper surface of the shell, a first groove is formed in the bottom end of the inner wall of the second groove, and a transmission shaft arranged on a motor is rotationally connected with the rotating structure; a threaded rod is fixed to the bottom end of a transmission shaft arranged on the motor, the threaded rod is in threaded connection with a threaded structure, the threaded structure is fixed to an insertion plate, a second threaded round hole is formed in one side of the insertion plate, the second threaded disc is inserted into the second threaded roun