Method of vapor phase polymerization, vapor phase polymerizer and blower

A method of vapor phase polymerization, which comprises blowing a gaseous monomer from a bottom of a fluidized bed reactor through a distributor plate into the fluidized bed reactor by means of a blower while feeding a solid catalyst for polymerization into the fluidized bed reactor to thereby form a fluidized bed in the fluidized bed reactor and carrying out a vapor phase polymerization reaction in the fluidized bed to thereby produce a polymer or copolymer, wherein the blower has a slide or rotational slide part between its discharge side as a high pressure side and its suction side as a low pressure side in a blower body casing, said slide or rotational slide part being provided with a noncontacted gas leakproof seal part being provided with a noncontacted gas leakproof seal part at a clearance ranging from 0.7 to 2.5 mm,

• wherein the solid catalyst for polymerization is a solid catalyst for olefin polymerization, the gaseous monomer is a gaseous olefin monomer and an olefin polymer or copolymer is obtained by the vapor phase polymerization reaction in the fluidized bed, and
• wherein unreacted gaseous monomer is discharged from the fluidized bed reactor and is cause to pass through a gas recycling path having a heat exchanger disposed upstream thereof and having a blower disposed downstream thereof so that the heat exchanged gaseous monomer is blown into the fluidized bed reactor.