Tubular static mixer

The utility model discloses a tubular static mixer. The tubular static mixer comprises a tube body, wherein a water inlet and a chemical inlet are formed in the side wall at the front part of the tube body; a water outlet is formed in the side wall at the rear part of the tube body; a servo drive device coaxial with the tube body is arranged at the front end part of the tube body; the output end of the servo drive device is connected with a long rotating shaft arranged in the tube body through a reduction gear; the tail end of the long rotating shaft is connected with a bearing pedestal arranged at the rear end of the tube body; mixing helical blades are arranged on the long rotating shaft from the front to the back; the distribution density of the mixing helical blades changes uniformly and becomes smaller and smaller from the front to the back. The tubular static mixer is simple in structure, can control the speed of stirring a mixed liquid in the tube body through the servo drive device, can well mix a che