Full flowing internal jecketed type polyvinyl chloride polymerization still

The utility model relates to a full flowing inner jacket type polyvinyl chloride polymerization kettle. The utility model is characterized in that an inner cooling jacket is arranged on an inner wall of a polymerization kettle cylinder, and a plurality of inner cooling baffle plates are arranged on an outer wall of the inner cooling jacket. Semicircular pipe jackets are welded at the outer sides of an upper seal head and a lower seal head, and a stirring shaft is installed in the bottom entering mode from the bottom end of the lower seal head. The connecting point of the lower seal head and the stirring shaft is sealed by a mechanical seal system. By using a full flowing form inner cooling jacket, the thickness of a heat transmitting wall can be effectively reduced, heat exchange area is increased and total heat transmitting coefficient is improved. Simultaneously, the semicircular pipe jackets are welded at the outer sides of the upper and the lower seal heads and lead into cooling water to cool the upper and the lower seal heads and the stirring shaft is installed in the bottom entering mode from the bottom end of the lower seal head. In the mode, the length of the stirring shaft can be shortened, the swing of a stirrer at the shaft end is reduced to prevent a mechanical sealer from being damaged because of the jumping of the stirring shaft and further the service life of the mechanical sealer is prolonged. The utility model is provided with a kettle top condenser which carries out the heat transmission of gas phase medium in the kettle to ensure that the heat quantity which is generated by the polymerization reaction in the kettle is removed.