To provide a method for continuously polymerizing an olefin in a vapor phase with which a product having a uniform degree of polymerization is obtained by using a simple and reliable apparatus and the method to bring retention time of polymer particles to be uniform.
In the method for continuously polymerizing the olefin in the vapor phase, a multistage vapor phase polymerization tank is used. The multistage vapor phase polymerization tank comprises a vertical fluidized bed-type vapor phase polymerization tank inside of which is divided into ≥2 fluidized bed-type vapor phase polymerization chambers with ≥2 porous plates and which is installed with a gas circulation device for flowing the monomer gas from the bottom to the head of the polymerization tank and a transport device for transporting catalyst-containing polymer particles from each polymerization chamber to a lower adjacent polymerization chamber. The transport device comprises a polymer particle-extracting pipe (having an opening and closing valve) and an adjacent pipe for sending the polymer particles to the lower adjacent polymerization chamber and an ejector installed between them. The ejector is operated by using a part of circulating monomer gas.
KAWAMATA SHOZO
KONNO YOICHI
