Fluidized bed polymerization reactor

The present invention provides a fluidized bed polymerization reactor, comprising: a tower, wherein the liquid distributor is provided with a gas phase located above the liquid distribution profile, thereby using the gas sparger into the reaction zone and the first region a second region; and a circulation unit for the gas from the tower top region of the material in the form of gas-liquid mixture is recycled back to the bottom region. Wherein the gas-liquid mixture in the bottom region of the gas-liquid separation, the resultant gas phase to the gas phase out of the distributor and thereby into the second region, and the resulting liquid phase through the distributor into the first region, so that the first temperature in the region lower than the temperature in the second region. Thereby producing a broad molecular weight distribution polymers.