Abstract: An apparatus for carrying out a gas-phase olefin polymerization having a first polymerization zone having a cylindrical segment of diameter D01, a second polymerization zone having a cylindrical upper part of diameter D05 and a cylindrical lower part of diameter D06, a separation zone of diameter D04, a first connecting element of diameter D03, which is a bend of radius R03 or has a bend part of radius R03, a gas recycle line of diameter D08, a transition segment of diameter D02, and a second connecting element of a diameter D09, which is a bend or has a bend part, wherein the ratio D04 to D05 is 1.0 to 1.5, the ratio D05 to D06 is 1.2 to 2, the ratio R03 to D03 is 1 to 6, the ratio D03 to D01 is 0.3 to 0.85, and the ratio D08 to D02 is 1.0 to 2.2.

Abstract: Fluidized-bed reactor for the gas-phase polymerization of olefins including a gas distribution grid installed in a lower part of the fluidized-bed reactor and a gas recycle line, which is equipped with a compressor and a heat exchanger and which is connected at the upper end with the top of the fluidized-bed reactor, wherein the gas recycle line splits at the lower end in at least two horizontal branches which are connected tangentially with the fluidized-bed reactor below the gas distribution grid and a process for preparing an olefin polymer carried out in the fluidized-bed reactor.

Abstract: Fluidized-bed reactor for the gas-phase polymerization of olefins including a gas distribution grid installed in a lower part of the fluidized-bed reactor and a gas recycle line, which is equipped with a compressor and a heat exchanger and which is connected at the upper end with the top of the fluidized-bed reactor, wherein the gas recycle line splits at the lower end in at least two horizontal branches which are connected tangentially with the fluidized-bed reactor below the gas distribution grid and a process for preparing an olefin polymer carried out in the fluidized-bed reactor.