Abstract: A process for producing polyethylene compositions in the presence of a catalytic system of ethylene polymerizing catalyst and cocatalyst in a multistage continuous reaction sequence consisting of successive liquid phase and gas phase polymerizations is disclosed. In the first step of the process, ethylene and optionally hydrogen and comonomer are polymerized in a first loop reactor in a low boiling hydrocarbon medium in the presence of ethylene polymerizing catalyst and cocatalyst. The reaction mixture is then removed and then transferred to a second loop reactor where polymerization is continued by addiing ethylene, hydrogen and optionally inert hydrocarbon, comonomers and cocatalysts. Thereafter, the reaction mixture is removed from the second loop reactor along with an essential part of the reaction medium and transferred to a gas phase reactor where polymerizing is continued in the presence of added ethylene and optionally hydrogen, comonomers and cocatalysts to form an end product.

Abstract: The invention relates to a fluidized-bed reactor for polymerization of olefins, said reactor comprising an upper section of the reactor acting as a polymerization space in which olefin monomers are polymerized in a fluidized bed formed by polymerizing particles and a lower section of the reactor acting as a mixing space through which circulating gas removed from the top of the polymerization space is passed to the fluidized bed contained in the lower part of the polymerization space through a horizontal gas distributor plate in order to maintain the fluidized state of the bed, in which arrangement the circulating gas is passed to the lower section of the reactor via one or more inlet nozzles and the bottom section of the reactor is additionally provided with means for directing the circulating gas.

Abstract: A fluidized bed polymerization process in which a central mixing element sweeps the interior of the bed. The mixing element contains agitator arm which pass adjacent to the reactor walls and a have a perforated surface. Gas is directed to the central mixing shaft and distributed to the agitator arms.

Abstract: The invention concerns a method and an equipment for taking a sample in slurry polymerization. The sample is taken directly from the liquid phase of the reactor (15) through an in-line filter (40). The slurry flow is maintained in the in-line filter (40) at a sufficiently hight level to prevent immobilization of polymer or catalyst particles on the filter face of the in-line filte (40).

Abstract: A process for manufacturing bimodal olefin polymers and copolymers having a ratio between low molecular weight fractions within the range of 40:60-70:30, by mixing under shear conditions 5-50 percent by weight of a low molecular weight unimodal polyolefin having a molecular weight (Mw) between 15,000-30,000, and 95-50 percent by weight of a bimodal polyolefin having a ratio between low molecular weight fractions and high molecular weight fractions within the range of 30:70-55:45. According to a preferred embodiment, there is used a multi-phase process including a loop reactor followed by a gas-phase reactor, wherein a part of the product coming out from the loop reactor is separated and combined with the bimodal product coming out from the gas-phase reactor.